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TECHNICAL FIELD
The present invention is directed to a method and apparatus for voice over IP system recovery for service and packet groups based on failure detection thresholds.
BACKGROUND
In recent years the Internet and the Internet Protocol have played a larger role in the field of telecommunications. Packet data protocols, such as the Internet Protocol (IP), have been used to deliver packet and voice services to subscribers. Voice over IP is one example of a packet data protocol being used to deliver voice services to telecommunications subscribers. Telecommunications networks, however, must be configured to support this new paradigm of providing voice services.
In the past, an area receiving telecommunications service may receive the service through a dedicated circuit or circuit group of some type. In the wired world, this dedicated circuit may take the form of a trunk or a dedicated time-slot on a trunk. Because each call is allocated a dedicated circuit, there was a high degree of predictability of bandwidth once a circuit was allocated for a communication session. There were also a predictable number of voice circuits available once a circuit group was established. Delivering Real Time Transport Protocol (RTP) packets in a VoIP network is not as predictable. Because of the unpredictable nature of packet networks, voice calls routed over packet networks tend to be less reliable. Call failures caused by this unreliability may be more common.
In the realm of VoIP calls, an area served is typically referred to as a service group or packet group. A certain number of IP addresses may be allocated to a service group. If too many calls are routed to a service group or if a service group is experiencing technical difficulties, call failures may occur in configuring an RTP session between two IP endpoints. This type of call failure may occur before a bearer is allocated at the RTP server, which may cause call failures. If too many call failures occur, calls may need to be re-routed to a different service group. Or, if call failures are frequent, the number of IP addresses allocated to a service group may have to be modified. Thus, the number failures and types of failures occurring in a service group must be monitored.
SUMMARY
A system comprising a SIP failure tracker, wherein the SIP failure tracker monitors SIP failures and issues an alert if a SIP failure threshold is exceeded.
A method in another application, the method comprising the steps of receiving a failure message, incrementing a fail count, comparing the fail count to a failure threshold, and rerouting call traffic if the fail count exceeds the failure threshold.
DESCRIPTION OF THE DRAWINGS
Features of example implementations of the invention will become apparent from the description, the claims and the accompanying drawings in which:
FIG. 1 is a diagram of a system in which a method and apparatus for voice over IP system recovery for service and packet groups based on failure detection thresholds may reside.
FIG. 2 is a representation of one implementation of a method and apparatus over IP system recovery apparatus for service and packet groups based on failure detection thresholds.
FIG. 3 is a representation of one implementation of a method and apparatus for voice over IP system recovery for service and packet groups based on failure detection thresholds.
DETAILED DESCRIPTION
As previously mentioned, in the arena of VoIP calls, an area may be served by a service group or packet group. There may a fixed number of Internet Protocol (IP) addresses allocated to a service group. The allocated IP addresses may be used to support communication sessions such as, voice over IP calls, or packet data services. These communication sessions may be routed through mobile switching centers and other telecommunications network components. If failures reach a certain threshold, operators may want to be informed so they may reroute calls to other service groups and/or adjust the number of IP addresses that are allocated to a service group.
Turning to FIG. 1 , which is a diagram of a system architecture where the method and apparatus for voice over IP system recovery for service and packet groups based on failure detection thresholds may reside. The network 100 may comprise an originating MSC 105 , a terminating MSC 110 , an originating network 115 and a terminating network 120 .
The MSCs 105 , 110 may be mobile switching centers (MSC), SE switches, private branch exchanges, or any other type of switching devices that may be used to connect two communication devices attempting to establish a communication session. The networks 115 , 120 may be public switched telephone networks (PSTN), wireless networks, public land mobile networks (PLMN), IP multimedia subsystems (IMS), Internet Protocol networks, or any other types of networks that may be used to establish a communication session between two communication devices. A communication session may be a landline telephone call, a mobile phone call, a packet switched call, or any other means of establishing a connection between two communication devices. A communication device may be a mobile phone, a landline phone, an Internet phone, or any other equipment that may be used to establish a communication session. The communication paths between the MSCs 105 , 110 , and between the MSCs 105 , 110 and the networks 115 , 120 may be used for signaling as well as establishing a bearer path.
The originating MSC 105 may further comprise an originating Executive Cellular Processor (O-ECP) 125 , an originating Flexent Packet Switch (O-FPS) 130 , and a human machine interface (HMI) 145 . Similarly, the terminating MSC 110 may further comprise a terminating FPS (T-FPS) 135 and a terminating ECP (T-ECP) 140 . One of ordinary skill in the art will readily appreciate that an ECP may provide basic call processing service functions needed for packet and voice call establishment. An FPS may provide call routing services for packet calls.
The O-ECP 125 may be directly or indirectly communicatively coupled to a base site controller resident in the originating network 115 . The base station controller in the originating network 115 may be in communication with a communications device. The O-ECP 125 may also be communicatively coupled to the O-FPS 130 . The O-FPS 135 may be communicatively coupled to the T-FPS 135 that is communicatively coupled to the T-ECP 140 . The T-ECP 140 may be directly or indirectly communicatively coupled to a base site controller resident in the terminating network 120 . The base site controller in the terminating network 120 may be in communication with a communications device.
When a data call or communication session originates from the originating network 115 , signaling to establish the call may be routed through the O-ECP 125 which further routes the signaling through the O-FPS 130 . The O-FPS 130 may signal the T-FPS 135 . Signaling between the T-FPS 135 and the T-ECP 140 may lead to the call being routed to the terminating network 120 . The call may originate from a wireless network, a landline network or any other type of network capable of originating a communication session. Similarly the call may terminate on a wireless network, a landline network or any other type of network capable of terminating a communication session.
In an embodiment, an interface between the O-ECP 125 and the O-FPS 130 may be a proprietary version of IS-41. Similarly, an interface between the T-FPS 135 and the T-ECP 140 may be a proprietary version of IS-41. Although in this embodiment the interface between the O-ECP 125 and the O-FPS 130 , and the T-ECP 140 and the T-FPS 135 is proprietary version of IS-41, these interfaces may be any type of interface that is supports sending or receiving messages in a network. The O-FPS 130 and the T-FPS 135 may further support a SIP interface to perform SIP signaling in the setup of SIP calls.
Typically when a SIP call is established, the O-ECP 125 sends a IS-41 setup message to the O-FPS 130 . The setup message may be comprised of, among other fields, a service group (SG) number. One of ordinary skill in the art will readily appreciate that a service group and packet group are analogous to a trunk group in the circuit switched domain of telecommunications. The O-FPS 130 may translate the SG number into a packet group (PG) number. The PG number may be used to route the call. The O-FPS 130 may set a timer and send a SIP Invite message to the T-FPS 135 .
In a successful scenario, SIP signaling continues until a bearer channel is established for the call, which results in an RTP session between SIP endpoints. If, for whatever reason, a bearer channel or call cannot be established, the O-FPS 130 may send a FAIL_X message to the O_ECP 125 . Although in this embodiment an IS-41 FAIL_X message is sent when a call cannot be established, any type of signaling message may be sent to indicate that a call has not been completed.
Also communicatively coupled to the O-MSC 105 is the HMI 145 . The HMI 145 may provide a way for an operator to communicate with and MSC. The HMI 145 may be a dumb terminal, a remote computer, or any other type of terminal that may be used to allow a human to enter commands into an MSC. The operator may use the HMI 145 to configure values of parameters that reside on the O-MSC 105 . Although the HMI 145 is shown communicatively coupled to the O-MSC 105 , the HMI may be communicatively coupled to any MSC or node in the network. Further, the HMI 145 may be used to set parameters that may reside in any MSC or node in the network.
Turning to FIG. 2 , which is a diagram of a system 200 in which an embodiment of the method and apparatus for voice over IP system recovery for service and packet groups based on failure detection thresholds may reside. The system 200 is comprised of the O-ECP 105 , the originating network 115 and the O-FPS 130 . The O-ECP 105 may be further comprised of a SIP failure monitor 205 , a SIP failure handler 210 and a call handler 215 . The SIP failure monitor 205 and the SIP failure handler 210 a SIP failure tracker. Although the SIP failure monitor 205 , SIP failure handler 210 and the call handler 215 are depicted on the O-ECP 105 , the SIP failure monitor 205 , SIP failure handler 210 and the call handler 215 may reside on any node or be distributed throughout any number of nodes that comprise a communications network.
The call handler 215 may be communicatively coupled to the originating network 115 via the O-ECP 105 . The call handler 215 may also be communicatively coupled to the O-FPS 130 via the O-ECP 105 . Although the system 200 is depicted as being communicatively coupled with an O-FPS 130 , the system 200 may be communicatively coupled with any type of telecommunications node or device that may be able to complete signaling to establish a voice-over IP call.
The call handler 215 may also be communicatively coupled to the SIP failure handler 210 . The SIP failure handler 210 may be communicatively coupled to the call handler 215 and the SIP failure monitor 205 . Further, the call handler may be communicatively coupled with the HMI 145 . The SIP failure monitor 205 may be communicatively coupled with the call handler 215 . The interfaces between the SIP failure monitor 205 , SIP failure handler 210 , call handler 215 and HMI 145 may be function calls, inter-process messaging or any other means to communicate between processes, firmware, hardware or nodes that reside in a communications network.
When a call is connected through the O-ECP 105 the call handler 215 may execute all the basic call processing function that is regularly handled by the O-ECP 105 . In the process of setting up a voice over IP call, the O-ECP 105 through the call handler 215 may send an IS-41 setup message to the O-FPS 130 . The setup message may comprise, among other fields, an SG, an IP address which may be used as a bearer channel, and a transaction identifier that is associated with the setup message.
The O-FPS 130 may attempt to establish a communication session by sending a SIP Invite message to the T-FPS 135 . One of ordinary skill in the art will readily appreciate that a SIP Invite is a message sent to a callee to establish a voice over IP connection with the callee. When the O-FPS 130 sends the SIP Invite, the O-FPS 130 may also start a timer. If the T-FPS 135 does not respond to the SIP Invite before the timer expires, delivery of the SIP Invite is considered to have failed. When delivery of a SIP Invite message fails, the O-FPS 130 may format a FAIL_X IS-41 message that is sent to the O-ECP 105 . When the O-FPS 130 sends the FAIL_X message, the FAIL_X message may comprise a service group (SG) number, a failure reason, a failure type, and a transaction identifier and other fields that may be associated with the failure of a SIP communication session. The transaction identifier is associated with the setup message sent to establish the communication session. The service group number may be the number of the service group to which the setup message was sent. A failure reason may be, for example, a SIP interworking failure, a SIP resource failure, or any other reason code that may be associated with a failed SIP Invite message. The failure type may be a failure to seize trunk, a failure to create an RTP session, SIP connectivity problem, time-out, failed translation, provisioning failure, link failure or any other reason code that may be associated with a failed call. The failure type and failure code may be fields that are added to the FAIL_X message.
When the call handler 215 receives a FAIL_X message, the call handler 215 may forward the FAIL_X message to the SIP failure handler 210 . The SIP failure handler 210 may printout out the SG number, failure reason and failure type that comprises the FAIL_X message. The SIP failure handler 210 may print this information to a read only printer (ROP) that may be communicatively coupled to the O-MSC 105 . The SIP failure handler 210 may then send a failure alert message to the SIP failure monitor 205 to inform the SIP failure monitor 205 that the failure has occurred. The failure alert message may comprise at least the SG number associated with the FAIL_X message.
The SIP failure monitor 205 may track or count the number of failures that have occurred for each SG by maintaining a fail count for each SG. Each SG may also have an associated failure threshold. If the fail count for an SG exceeds the failure threshold for that SG, the SIP failure monitor 205 may issue an alert by printing a message to an ROP. If the fail count for an SG exceeds the failure threshold for that SG, the SIP failure monitor 205 may also send a failure threshold alert message to the call handler 215 to inform the call handler 215 that the failure threshold associated with an SG is exceeded. The failure threshold alert message may comprise at least the SG number of the service group that has exceeded its failure threshold. Upon receipt of the failure threshold alert message, the call handler 215 may then abstain from routing incoming calls to the SG that has exceeded its associated failure threshold.
In an embodiment, the SIP failure monitor 205 keeps a fail count of each failure alert message received for an SG. Once the fail count reaches or exceeds the failure threshold, regardless of how long it takes to exceed the failure threshold, the SIP failure monitor 205 sends a failure threshold alert message to the SIP failure handler 210 . This type of failure threshold may be called a hard failure threshold. For example, the failure threshold may be set at one hundred. It may take two days to meet or exceed the one hundred failure threshold, but once the failure threshold is met or exceeded the SIP failure monitor 205 may send a failure threshold alert message to the SIP failure handler 210 .
In another embodiment, the fail count is cleared at regular time intervals. These regular time intervals may be called static time windows. For example, the fail count may be cleared every thirty minutes. Thus the failure threshold alert message is only sent if the failure threshold is met or exceeded during a time interval. That is, before the fail count is cleared.
In still another embodiment, a time window is maintained that is adjusted at regular intervals. This adjusted time window may be called a moving time window. If the SIP failure monitor 205 receives a failure alert message that falls outside the time window, the fail count will not reflect or count receipt of the failure alert message. For example, consider a time window that is thirty minutes wide and that is updated every minute. If a first failure alert message is received at time zero minutes when the fail count is zero, the fail count is incremented to one. If a second failure alert message is received at time ten minutes, the fail count may be incremented to two. In this example, each minute the time window is moved a minute. Assume at a thirty minute mark the fail count is still two. When the window reaches the thirty first minute, the fail count is reduced by one because the first failure alert message now falls outside the time window. The window continues to move each minute, and a failure threshold alert message is only sent if the fail count that falls within the time window equals the failure threshold. Although the size of the of the time window in this example was thirty minutes, the size of the time window may be larger or smaller than thirty minutes.
Regardless of how the fail count is maintained, in an embodiment, if the fail count exceeds the failure threshold, the fail count is not reset. Instead, once the fail count exceeds the failure threshold, the fail count remains unchanged until the operator resets the fail count. The operator may reset the fail count by entering a command via the HMI 145 . In an alternative embodiment the operator does not have to reset the fail count via the HMI 145 , the fail count is reset once it exceeds the failure threshold.
The system 200 in one example comprises a plurality of components such as one or more of computer software components. A number of such components can be combined or divided in the system 200 . An example component of the system 200 employs and/or comprises a set and/or series of computer instructions written in or implemented with any or a number of programming languages, as will be appreciated by those skilled in the art. The system 200 in one example comprises a vertical orientation, with the description and figures herein illustrating one example orientation of the system 200 , for explanatory purposes.
The system 200 in one example employs one or more computer-readable signal-bearing media. The computer-readable signal-bearing media store software, firmware and/or assembly language for performing one or more portions of one or more implementations of the invention. The computer-readable signal-bearing medium for the system 200 in one example comprise one or more of a magnetic, electrical, optical, biological, and atomic data storage medium. For example, the computer-readable signal-bearing medium comprise floppy disks, magnetic tapes, CD-ROMs, DVD-ROMs, hard disk drives, and electronic memory.
Turning now to FIG. 3 , which is a flow chart that illustrates a method and apparatus for voice over IP system recovery for service and packet groups based on failure detection thresholds. The method 300 may receive a FAIL_X message 310 . The O-FPS 130 may have sent the FAIL_X message in response to a SIP Invite message time-out. The FAIL_X message may comprise at least an SG, a failure reason, and a failure type. In step 320 , the method 300 may print the contents of the FAIL_X message to a ROP. This may include printing the SG associated with the FAIL_X message as well as any failure reasons or failure types associated with the FAIL_X message.
A fail count may be incremented 330 . The method 300 may determine if the fail count exceeds a failure threshold 340 associated with an SG. If the fail count does not exceed the failure threshold, the method 300 returns to a state where it is ready to receive FAIL_X messages. If the fail count exceeds the failure threshold, a failure threshold alert message that is associated with a service group may be sent 350 to the call handler 215 . The call handler 215 may then route calls away from the service group associated with the failure threshold alert message. In determining whether the fail count exceeds the failure threshold, the method may compare the fail count to the failure threshold in the manner described above. Thus, the method may use a hard failure threshold, a static time window or a moving time window.
The steps or operations described herein are just for example. There may be many variations to these steps or operations without departing from the spirit of the system 200 and method 300 . For instance, the steps may be performed in a differing order, or steps may be added, deleted, or modified.
Although example implementations of the system 200 and method 300 have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions, and the like can be made without departing from the spirit of the method 300 and these are therefore considered to be within the scope of the system 200 and method 300 as defined in the following claims.
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A system comprising a SIP failure chandler, wherein the SIP failure handler monitors SIP failures and issues an alert and reroutes call traffic based on a service group number if a SIP failure threshold is exceeded wherein the service group number is associated with a detected failure, where the service group comprises a plurality of IP addresses.
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BACKGROUND
[0001] In the manufacture of integrated circuits, copper interconnects are generally formed on a semiconductor substrate using a copper damascene process. In this process, a trench is etched into a dielectric layer and the trench is filled with a barrier layer and a seed layer. For instance, a physical vapor deposition (PVD) sputter deposition process may be used to deposit a tantalum nitride and tantalum barrier layer into the trench. This may be followed by a PVD sputter process to deposit a copper seed layer into the trench. Generally, an electroplating process is then used to fill the trench with copper metal to form the interconnect. As device dimensions scale down, however, the trenches used to form interconnects become more narrow and issues start to arise in the copper seeding and electroplating processes. For instance, problems such as trench overhang tend to occur that pinch off the trench opening and cause voids to appear within the copper interconnect.
[0002] To avoid the issues that electroplating deposition presents, an electroless deposition process may be used to deposit copper into the narrow trenches. An electroless deposition process deposits a metal from a solution (e.g., an electroless plating bath) onto a substrate by a controlled chemical reduction reaction in the absence of an external electric current. Electroless deposition processes offer more scalability than electroplating because electroless processes can deposit metal directly onto barrier materials without an intervening seed layer. Furthermore, electroless deposition processes have the ability to plate on thin copper seed layers without terminal effects as seen with electroplated copper.
[0003] For copper interconnects, a typical electroless process includes cleaning the semiconductor substrate, covalendy attaching a metal catalyst to the substrate surface, activating the metal catalyst, and depositing the metal into the trench using an electroless process. Unfortunately, the metal needed to catalyze the electroless deposition process can cause the electrical line resistance of the copper interconnect to increase. The metal catalyst becomes an impurity in the copper metal, and it is believed that this impurity disrupts the flow of electrons in the copper metal, thereby causing electron scattering and leading to a measurable increase in resistance. In some cases, this increase in electrical resistance of the copper interconnect can be as much as ten percent. The presence of the metal catalyst on the copper seed layer may also prevent grain growth in the electrolessly deposited copper. As such, improved electroless deposition processes for copper interconnects are needed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a palladium immobilization process.
[0005] FIG. 2 illustrates a coupling agent and a metal catalyst.
[0006] FIGS. 3A to 3 F illustrate an electroless deposition process.
[0007] FIG. 4 is a method of forming a copper interconnect in accordance with an implementation of the invention.
[0008] FIGS. 5A to 5 G illustrate the method described in FIG. 4 .
DETAILED DESCRIPTION
[0009] Described herein are systems and methods of reducing electrical resistance in copper interconnects formed by conventional electroless deposition processes. In the following description, various aspects of the illustrative implementations will be described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. However, it will be apparent to those skilled in the art that the present invention may be practiced with only some of the described aspects. For purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the illustrative implementations. However, it will be apparent to one skilled in the art that the present invention may be practiced without the specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative implementations.
[0010] Various operations will be described as multiple discrete operations, in turn, in a manner that is most helpful in understanding the present invention, however, the order of description should not be construed to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation.
[0011] Implementations of the invention enable the formation of copper interconnects having a reduced electrical resistance relative to conventional copper interconnects. The novel copper interconnects of the invention are formed using an electroless deposition process. The electroless deposition process utilizes a palladium immobilization process (PIP) whereby a palladium catalyst is used to facilitate the electroless deposition process. In accordance with implementations of the invention, ultraviolet radiation is used to remove the palladium catalyst from portions of a substrate where the copper interconnects are to be formed. It is believed that ultraviolet radiation breaks the bond that affixes the palladium catalyst to the substrate. Removing the palladium catalyst prevents the palladium from contaminating the copper metal and increasing the electrical line resistance of the copper interconnects.
[0012] FIG. 1 is a conventional palladium immobilization process (PIP) 100 for initiating an electroless deposition process. The PIP process 100 begins by providing a semiconductor substrate onto which a copper interconnect may be formed ( 102 ). For instance, the semiconductor substrate may be a semiconductor wafer that includes a dielectric layer on its surface. The dielectric layer may include at least one trench in which the copper interconnect may be formed.
[0013] The substrate may be cleaned to remove impurities, contaminants, and/or oxides ( 104 ). The cleaning solution used may be an alkaline solution or a pure water rinse. The cleaning solutions may contain surfactants (e.g. polyoxyethylene derivatives), phosphates, and/or carbonates in alkaline media. These cleaning solutions tend to make the semiconductor substrate more hydrophilic and tend to remove loose particles due to the fluid motion on the wafer.
[0014] After the cleaning process, a metal catalyst is deposited onto the substrate using a coupling agent ( 106 ). Turning to FIG. 2 , an exemplary coupling agent 200 is shown. The coupling agent may include a silane group 202 , which has the ability to bond strongly to many different types of substrates, including semiconductor substrates. The coupling agent may also include a nitrogen group 204 , which has the ability to bond to the metal catalyst. The nitrogen group 204 may be provided by an amine or azo group. For instance, in the implementation shown, the coupling agent 200 may be an azo-silane molecule and the nitrogen group 204 may be provided by an azo group. A metal catalyst 206 may bond to the nitrogen 204 of the coupling agent 200 . In the implementation shown in FIG. 2 , the metal catalyst is palladium metal. In alternate implementations, the metal catalyst 206 may be another metal, including but not limited to ruthenium, iridium, rhenium, rhodium, or osmium.
[0015] The coupling agent 200 and the metal catalyst 206 may be applied using any one of a variety of techniques including, but not limited to, wet or dry chemical vapor deposition (CVD). In one implementation, the substrate may be immersed in a single solution containing both the coupling agent 200 and the metal catalyst 206 . In another implementation, the coupling agent 200 and the metal catalyst 206 may be provided in separate solutions, and the substrate may be separately immersed in each solution. When the substrate is immersed, the coupling agent 200 , such as the azo-silane molecule, attaches to the substrate with the silane group bonded to the substrate and the azo group exposed. The metal catalyst 206 , such as the palladium metal, bonds to the nitrogen in the exposed azo group. This results in the formation of a layer of metal catalyst ions over the nitrogen.
[0016] Returning to FIG. 1 , the metal catalyst is then activated after bonding to the substrate ( 108 ). As is well known in the art, the metal catalyst may be activated by exposing the metal to a reducing agent. When activated, the metal catalyst may covalendy bond to the nitrogen group of the coupling agent. A monolayer of activated metal catalyst is now affixed to the surface of the substrate. The underlying nitrogen acts as an immobilizing structure which holds the metal catalyst in place on the substrate. The substrate may then be immersed in a plating bath and an electroless deposition process may be carried out to deposit metal, such as copper, over the metal catalyst ( 110 ). In some implementations, a spray technique may be used to carry out the electroless deposition process in lieu of an immersion technique.
[0017] The metal catalyst generally serves one of two purposes in most electroless deposition processes. In some electroless processes, the metal catalyst may serve as a nucleation site for the electroless deposition to occur. For instance, metals such as tantalum or titanium serve as poor nucleation sites for the electroless deposition of copper metal. For an electroless deposition of copper to occur on these surfaces, a metal catalyst such as palladium may be affixed to the tantalum or titanium using a coupling agent. The palladium may then function as a nucleation site for the electroless deposition of copper metal to occur.
[0018] In this and other electroless processes, the metal catalyst may also function as an anchoring site for polymeric additives that are used to promote gap fill, particularly when high-aspect ratio gaps are being filled. This is explained in the illustrations of FIGS. 3A to 3 F. Starting with FIG. 3A , a substrate 300 may be provided that includes a dielectric layer 302 that has been etched to form trenches 304 . The trenches 304 may have a high-aspect ratio. As shown in FIG. 3B , a copper seed layer 306 may be deposited onto the substrate 300 to serve as a nucleation site for the electroless deposition of copper metal. The copper seed layer 306 may be deposited using known processes such as physical vapor deposition (PVD) or CVD. Although not shown, a barrier layer, such as a tantalum or tantalum nitride layer, may be deposited before the copper seed layer 306 as is well known in the art.
[0019] FIG. 3C illustrates what would happen if an electroless deposition process were to be carried out at this point. As shown, copper metal 308 that is deposited by the electroless process tends to deposit primarily on a top surface 310 of the substrate 300 . The copper metal 308 generally avoids traveling down into the high-aspect ratio trenches 304 and often gets deposited on the top surface 310 before it even has an opportunity to travel down into the trenches 304 . The result of this process is poor gap fill and incomplete copper interconnects.
[0020] To overcome this issue, a polymeric additive may be added to the plating bath used in the electroless deposition process. The polymeric additive has the ability to suppress the deposition of copper metal on the top surface 310 of the substrate 300 when it is anchored to the top surface 310 by a metal catalyst. Suppressing metal deposition on the top surface forces the metal ions to travel down into the narrow trenches where they deposit and fill the gap. The polymeric additive generally does not inhibit metal deposition within the features, such as the narrow trenches, as the high molecular weight of the polymer substantially prevents it from entering such features. In some implementations the polymeric additive may be present in the electroless plating solution, while in other implementations the polymeric additive may be deposited prior to the plating step. Accordingly, turning to FIG. 3D , a metal catalyst 312 may be affixed to the surface of the copper seed layer 306 using a coupling agent 314 . The metal catalyst 312 serves as an anchoring site for the polymeric additive.
[0021] Next, as shown in FIG. 3E , an electroless plating process may be carried out using the plating bath with a polymeric additive 316 . The polymeric additive 316 becomes deposited on the metal catalyst 312 and prevents copper metal 308 from depositing onto the top surface 310 of the substrate 300 . The copper metal 308 must travel down into the trenches 304 where it can deposit on the copper seed layer 306 and the metal catalyst 312 . The polymeric additive 316 therefore promotes gap fill by suppressing copper deposition on the top surface 310 .
[0022] A critical shortcoming with the process described in FIGS. 3A to 3 E is that the metal catalyst 312 coats the entire copper seed layer 306 , including the bottom and sides of the trenches 304 . It is believed that the presence of the metal catalyst 312 , such as palladium, within the narrow trenches 304 causes the resistance of the subsequently formed copper interconnects to increase. As described above, the palladium or other metal catalyst may become embedded within the copper metal 308 and cause electron scattering within the interconnect.
[0023] Accordingly, FIG. 4 is a method 400 of forming a copper interconnect in accordance with an implementation of the invention. The method 400 of the invention addresses the issue of the metal catalyst contaminating the copper interconnect. First, a substrate is provided upon which a copper interconnect may be formed ( 402 ). The substrate may be formed using a bulk silicon or a silicon-on-insulator (SOI) substructure. In other implementations, the substrate may be formed using alternate materials, which may or may not be combined with silicon, that include but are not limited to germanium, indium antimonide, lead telluride, indium arsenide, indium phosphide, gallium arsenide, or gallium antimonide. Although a few examples of materials from which the substrate may be formed are described here, any material that may serve as a foundation upon which a semiconductor device may be built falls within the spirit and scope of the present invention.
[0024] The substrate may include a dielectric layer formed on a surface of the substrate. The dielectric layer is generally used as an interlayer dielectric (ILD). Example of dielectric materials that may be used to form the dielectric layer include, but are not limited to, silicon dioxide (SiO 2 ), carbon doped oxide (CDO), organic polymers such as perfluorocyclobutane (PFCB), and fluorosilicate glass (FSG). The dielectric layer may include one or more trenches that have been etched into the dielectric layer. The trenches may be etched using well known photolithography techniques. It is within the trenches that the copper interconnects will be formed.
[0025] A copper seed layer may be deposited on the substrate ( 404 ). The copper seed layer is a very thin layer of copper metal that serves as a nucleation site for the electroless deposition of copper metal. The copper seed layer may be deposited using well known processes for depositing seed layers, including but not limited to chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), sputter deposition, and atomic layer deposition (ALD).
[0026] The substrate with the copper seed layer is then processed to deposit a coupling agent and a metal catalyst to the substrate ( 406 ). In some implementations, the substrate may be immersed in a solution that contains the coupling agent and the metal catalyst. In other implementations, the coupling agent and the metal catalyst may be provided in separate solutions, and the substrate may be immersed in each of the solutions separately. In one implementation, the coupling agent may be an azo-silane molecule and the metal catalyst may be palladium. The process to attach the metal catalyst to the substrate may be a PIP process, as described above. In other implementations, alternative coupling agents and metal catalysts may be used.
[0027] The metal catalyst generally forms a monolayer that covers substantially the entire surface of the copper seed layer, including the sidewalls and bottom of the trenches. As described above, the metal catalyst may degrade the performance of the subsequently formed copper interconnect. As such, in accordance with implementations of the invention, the metal catalyst and the coupling agent are then removed from within the trenches ( 408 ).
[0028] In some implementations, the metal catalyst and the coupling agent are removed using ultraviolet radiation. It is believed that ultraviolet radiation breaks the bond that affixes the metal catalyst to the substrate, thereby rendering the coupling agent inactive. For instance, in one implementation, ultraviolet radiation with a wavelength between 190 nanometers (nm) and 200 nm, and at a dose between 1 joule/cm 2 (J/cm 2 ) and 10 J/cm 2 , may be used to break the bond between the silane group and the azo group. More specifically, the silicon-carbon bond is broken to form silicon hydroxide. When this bond is broken, the azo group, as well as the metal catalyst bonded to the azo group, become detached from the surface of the substrate and may be removed. Therefore, when ultraviolet radiation is applied within the trenches, the azo groups and metal catalyst become detached from the sidewalls and bottom of the trenches and may then be removed. This reduces or prevents the occurrence of electron scattering by the metal catalyst which would otherwise remain in the trench and contaminate the later formed copper interconnect.
[0029] In accordance with the invention, the ultraviolet radiation may have a wavelength that ranges from 10 nm to 400 nm, and more preferably ranges from 190 nm to 200 nm. The radiation dose may range from 1 J/cm 2 to 30 J/cm 2 , and more preferably ranges from 1 J/cm 2 to 10 J/cm 2 . The ultraviolet radiation exposure may be restricted solely to the trench portions of the substrate by employing a mask or another similar device. Such a mask may be designed to only allow the ultraviolet radiation to expose the trenches while shielding the remainder of the substrate from the ultraviolet radiation. A mask similar to masks used in photolithography processes may be used. In other implementations, alternate devices such as shutters may be employed.
[0030] After the trenches are exposed to ultraviolet radiation, the metal catalyst may be activated ( 410 ). As described above, the metal catalyst may be activated by exposing the metal to a reducing agent. In the case of palladium, the reducing agent may be a hypophosphite compound or a derivative thereof. When activated, the metal catalyst may covalendy bond to the nitrogen group of the coupling agent and a monolayer of activated metal catalyst is now affixed to the surface of the substrate in all areas except within the trenches. The underlying nitrogen immobilizes the metal catalyst.
[0031] The substrate may then be immersed in a plating bath and an electroless deposition process may be carried out to deposit metal, such as copper, into the trenches over the copper seed layer ( 412 ). The copper seed layer, which becomes exposed when the metal catalyst is removed from the trenches, serves as a nucleation site for the electroless plating process. By removing the metal catalyst from the trenches, the copper metal may deposit in the trenches and grain growth will not be inhibited.
[0032] The electroless plating bath contains a polymeric additive that promotes gap fill by suppressing copper deposition on the top surface of the dielectric layer. The metal catalyst serves as an anchoring agent on the top surface of the dielectric layer to prevent the polymeric additive from going into the trench.
[0033] Finally, a chemical mechanical polishing (CMP) process may be used to remove excess metal after the deposition process ( 414 ). The CMP process planarizes the overall structure, thereby completing the formation of the copper interconnect structure.
[0034] The method 400 described in FIG. 4 may also include one or more cleaning steps. For example, the substrate may be cleaned prior to the electroless plating deposition process using a simple pure water rinse or a mildly acidic solution. The substrate may also be cleaned after the ultraviolet radiation exposure to remove the metal catalyst from the trenches. In some implementations, however, the bath used for the metal catalyst activation process may indirectly remove the metal catalyst from the trenches.
[0035] FIGS. 5A to 5 G illustrate the method of forming a copper interconnect described in FIG. 4 . Starting with FIG. 5A , a substrate 500 is provided upon which a copper interconnect may be formed. The substrate 500 may be formed using a bulk silicon, an SOI substructure, or alternate materials. The substrate 500 may also include a dielectric layer 502 formed on a surface of the substrate 500 . The dielectric layer may include one or more trenches 504 that have been etched into the dielectric layer 502 .
[0036] Turning the FIG. 5B , a copper seed layer 506 may be deposited on the substrate 500 . As before, the copper seed layer 506 is a very thin layer of copper metal that serves as a nucleation site for the electroless deposition of copper metal. Although not shown, a barrier layer, such as a tantalum or tantalum nitride layer, may be deposited before the copper seed layer 506 as is well known in the art.
[0037] In FIG. 5C , a coupling agent 508 and a metal catalyst 510 are deposited on the substrate 500 . In some implementations, the coupling agent 508 may be an azo-silane molecule and the metal catalyst 510 may be palladium. As shown, the metal catalyst 510 covers substantially the entire surface of the copper seed layer 506 , including the sidewalls and bottoms of the trenches 504 .
[0038] In FIG. 5D , ultraviolet radiation 512 is applied to the trenches 504 of the substrate 500 to detach the metal catalyst 510 from the sidewalls and bottoms of the trenches 504 and render the coupling agent 508 inactive. A photolithography mask 514 is used to restrict the ultraviolet radiation exposure to just the trenches 504 . As shown, the coupling agent 508 and the metal catalyst 510 are removed from the sidewalls and bottom of the trenches 504 .
[0039] Turning to FIG. 5E , the metal catalyst 510 may be activated. Again, the metal catalyst may be activated by exposing the metal to a reducing agent. The metal catalyst may now be covalently bonded to the nitrogen group of the coupling agent and a monolayer of activated metal catalyst is now affixed to the surface of the substrate in all areas except within the trenches. The underlying nitrogen immobilizes the metal catalyst.
[0040] In FIG. 5F , the electroless plating deposition process begins. The plating bath includes a polymeric additive 516 to promote gap fill. As shown in FIG. 5F , the polymeric additive 516 becomes anchored to the top surface of the dielectric layer 502 by the metal catalyst 510 while the copper metal 518 becomes deposited within the trenches 504 over the copper seed layer 506 . The copper metal 518 is prevented from depositing on the top surface of the dielectric layer 502 by the polymeric additive 516 . Finally, as shown in FIG. 5G , a CMP process may be used to remove excess metal and planarize the structure, completing the formation of one or more copper interconnects 520 .
[0041] Accordingly, a method for forming electrolessly deposited copper interconnects that are not contaminated by a metal catalyst has been disclosed. The presence of the metal catalyst is maintained on the field where it can anchor a high molecular-weight polymeric additive and prevent polymer diffusion into the trenches. The metal catalyst, however, is eliminated from the trenches where the catalyst might otherwise adversely affect the electrical resistance of the later formed copper interconnects. In some instances, it has been shown that removing palladium metal catalyst in this manner can decrease the electrical line resistance of electrolessly deposited copper interconnects by approximately ten percent.
[0042] The above description of illustrated implementations of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific implementations of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.
[0043] These modifications may be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific implementations disclosed in the specification and the claims. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.
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A method of forming an electrolessly deposited copper interconnect while reducing its electrical resistance comprises providing a substrate having a dielectric layer, wherein a trench portion including at least two sidewall surfaces and a bottom surface is etched into the dielectric layer, depositing a copper seed layer onto the substrate and within the trench portion, attaching a layer of a metal catalyst to the substrate and within the trench portion using a coupling agent, applying ultraviolet radiation to the trench portion to detach the metal catalyst from the sidewall surfaces and the bottom surface of the trench portion, activating the metal catalyst that remains attached to the substrate, performing an electroless plating process to deposit copper into the trench portion, and planarizing the deposited copper to form an interconnect. The result is a copper interconnect that is not contaminated with a metal catalyst that may increase its electrical resistance.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This nonprovisional patent application claims priority under 35 U.S.C. §119 to U.S. Provisional Application Ser. No. 61/173,003, filed on Apr. 27, 2009.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON COMPACT DISC
[0004] Not applicable.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The present invention relates to devices used to assess the penetrative performance characteristics of projectiles, and more particularly to such devices for simulating the anatomical features of game animals.
[0007] 2. Description of Related Art
[0008] Big game hunting is an exhilarating sport enjoyed by many enthusiasts around the world. According to the 2001 National Survey of Fishing, Hunting and Wildlife-Related Recreation, there are approximately 11 million big game hunters in the United States that spend $6.5 billion on hunting related equipment annually. Big game is most often taken with rifles, although large caliber pistols, shotguns, and archery equipment are also commonly used. The best way to prepare for big game hunting and ensure one's success in bringing down these large animals is to know how the projectile, e.g. the bullet or arrow, will perform when shooting the intended game animal.
[0009] There are a wide variety of shooting targets and ballistic methodologies used to test projectile performance. Some of the more popular targets are wet pack (water soaked newspaper), ballistic gelatin, water filled tanks, and metal sheets. All of these shooting targets are deficient for various reasons when trying to accurately simulate a projectile's damage on a living animal. A common shortcoming with each target is the lack of a full “shoulder to shoulder” representation.
[0010] Specifically, none of these existing targets comprise a heterogeneous stacked mixture of materials having properties similar to their biologic counterparts, leaving the hunter with insufficient knowledge of how the projectiles would perform on a live animal. Animals are composed of hide, muscle, bone, and internal organs. All of these tissues must be accounted for to accurately predict projectile performance using a mechanical model.
[0011] Shooting enthusiasts are often limited in the resources they can devote to effectively testing projectile incapacitation on game animals. Therefore, cost effective devices and methods are of great interest to these hunters. However, inexpensive devices generally fail to deliver the reliable simulation results required, because their simple structures do not provide accurate analogs to anatomical tissues. Moreover, a projectile's mechanical behavior varies significantly with respect to its penetrating medium. For example, modeling a 30-inch wide Cape buffalo by using only thirty inches ( 30 ″) of ballistic gelatin will not provide the user an accurate simulation of real life bullet performance. Since the gelatin block does not incorporate a bone simulant, the bullet's expansion, deceleration, and fragmentation results cannot be regarded as reliable. Many people continue to use these homogeneous targets strictly because better alternatives do not exist. Therefore, prediction of projectile performance on a live animal remains speculative, calling into question the use of such unreliable methods from the start.
[0012] U.S. Pat. No. 7,222,525 to Jones discloses a device for testing bullet penetration, however, it does not provide a means for keeping the gelatin block from moving after impact from the bullet. Furthermore, the device does not account for the effect of hide, bone, or internal organs on the projectile. Importantly, ballistic gelatin can only be used to simulate muscle, not internal organs. The specific gravity and mechanical properties of muscle are different than internal organs, because internal organs contain more liquid and gases.
[0013] U.S. Pat. No. 523,510 to Brunswig discloses a tank system to measure projectile penetration. Similar to most other penetration testing devices, that invention does not take into account the effect of bone or hide on the projectile's performance.
[0014] U.S. Pat. No. 5,850,033 to Mirzeabasov, et al., most closely replicates one half of a torso of a human. However, even if this device were employed, one could not predict the effect of a shoulder-to-shoulder shot on a big game animal. In order to determine the distance of penetration, the device must effectively be destroyed to find the end point of the projectile's path. Similar to Jones, the device does not provide a means for remaining in place at impact. Moreover, it does not provide selectively removable inserts to discern penetration depth or any simulant for internal organs.
[0015] Thus, none of the previously described devices take into account all four of the heterogeneous materials that would be penetrated by a projectile for a shoulder-to-shoulder shot on a big game animal. What is needed, therefore, is a torso simulation device for projectile performance testing which includes mechanical analogs or simulants for all anatomical tissues. It should enable quick and easy discernment of penetration depth and wound cavity by using selectively removable inserts that can be replaced for each test. The device should permit the installation of varying inserts and materials to closely approximate the actual width and specific gravity of a wide range of animals, including deer, elk, bear, eland, buffalo, and other big game. The device should also be a stable platform capable of withstanding movement in response to the high energy impact of a projectile, such as a rifle bullet or arrow. Finally, it should be relatively compact, portable, and simple to maintain in consideration of the distances required for testing in potentially remote locations.
SUMMARY OF THE INVENTION
[0016] Therefore, a device for simulating the torso of an animal to determine projectile penetration performance is provided, comprising a support frame; and a plurality of selectively removable simulant inserts, including a hide simulant insert, a muscle simulant insert, a bone simulant insert, and one or more internal organ simulant inserts, and wherein the simulant inserts are placed within the support frame in a predetermined order specific to the type of animal being simulated.
[0017] The support frame includes a mounting device to secure the support frame to a ground surface, as well as a base adapted to orient the support frame at a selectable angle relative to a projectile path. The support frame further includes a locking device adapted to secure the simulant inserts to the support frame. In a preferred embodiment, the locking device includes a fastener slidably disposed within a slot formed in the support frame, and an extended member adapted to contact one of the simulant inserts.
[0018] The hide simulant insert is preferably comprised of one or more sheets of real or imitation leather secured to a hide simulant frame.
[0019] The muscle simulant insert is preferably comprised of ballistic gelatin media.
[0020] The bone simulant insert is preferably comprised of one or more sheets of fiberglass.
[0021] The internal organ simulant inserts are preferably comprised of one or more liquid inserts and one or more air inserts. The liquid insert comprises a flexible container containing a liquid, such as water or other contents approximating the internal organs, and wherein the flexible container is secured to a liquid insert frame. The liquid insert frame includes at least one hole formed therein to permit liquid from the flexible container to flow away from the support frame after penetration by a projectile. The air insert comprises an air insert frame having a front side and a back side, and wherein a flexible sheet, such as a polyethylene sheet, is secured to the front side and the back side of the air insert frame.
[0022] In a preferred embodiment, the simulant inserts within the support frame approximate the width of the animal being simulated.
[0023] In another embodiment, the average specific gravity of the internal organ simulant inserts approximates the specific gravity of the internal organs of the animal being simulated.
[0024] Preferably, the simulant inserts are placed within the support frame in the following order: a first hide simulant insert; a first muscle simulant insert; a first bone simulant insert; one or more internal organ simulant inserts; a second bone simulant insert; a second muscle simulant insert; and a second hide simulant insert. Also, the internal organ simulant inserts are preferably comprised of one or more liquid inserts and one or more air inserts, and wherein the number and sequence of the liquid inserts and the air inserts are chosen to approximate the specific gravity and width of the animal being simulated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] 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.
[0026] FIG. 1 shows a fully assembled view of a preferred embodiment of the present invention.
[0027] FIG. 2 shows a frame used in connection with the embodiment of FIG. 1 .
[0028] FIG. 3 shows a locking device used to secure inserts within the frame.
[0029] FIGS. 4A and 4B show detailed views of the hide insert.
[0030] FIG. 5 shows a detailed view of the muscle insert.
[0031] FIG. 6 shows a detailed view of the bone insert.
[0032] FIGS. 7A and 7B show detailed views of the air insert.
[0033] FIG. 8 shows a detailed view of the water insert.
[0034] FIG. 9 shows a schematic diagram of a preferred orientation of the frame immediately prior to testing.
[0035] FIG. 10 shows a small frame suitable for smaller game animals.
DETAILED DESCRIPTION OF THE INVENTION
[0036] Before the subject invention is further described, it is to be understood that the invention is not limited to the particular embodiments of the invention described below, as variations of the particular embodiments may be made and still fall within the scope of the appended claims. It is also to be understood that the terminology employed is for the purpose of describing particular embodiments, and is not intended to be limiting. Instead, the scope of the present invention will be established by the appended claims.
[0037] In this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs.
[0038] Turning now to FIG. 1 , a preferred embodiment of the present invention, a torso simulator for ballistics testing, is illustrated. References in this description to projectiles includes any type of bullet fired by a firearm (such as handguns, rifles, and shotguns), projectiles used for military or law enforcement purposes, and projectiles used in archery equipment, such as arrows. When the term “projectile performance” is used herein, we mean an assessment of the projectile's penetration results, as well as trauma or other effects to other layers which have not been penetrated. For example, non-penetrated layers may be subject to cracking, bursting, or other perceptible deformations which are analogous to actual anatomical bruising, cracked or broken bones, or ruptured organs due to hydrostatic shock from projectile impact.
[0039] The fully assembled device comprises a support frame 100 , and a plurality of selectively removable simulant layers or inserts 200 , including a hide simulant insert 300 , a muscle simulant insert 400 , a bone simulant insert 500 , and one or more internal organ simulant inserts 600 . As will be explained in further detail below, the simulant layers or inserts 200 are placed within the support frame 100 in a predetermined order specific to the type of animal being simulated. The simulant inserts 200 simulate the hide, muscle, bone and internal organs of a big game animal, such as a whitetail deer, elk, grizzly bear, eland or cape buffalo.
[0040] The frame is best depicted in FIG. 2 and is preferably constructed from 6061-T6 and 6061-T6511 aluminum grades, although similar metals of equivalent properties may also be employed. The frame 100 includes a rear top support 1 , rear upright supports 2 , bottom rails 3 , side rails 4 , front upright supports 8 , front rail 9 , and rear rail 10 , all rigidly attached to form the static structure of the frame 100 as depicted in FIG. 2 . Corner braces 11 add additional stability to the frame 100 . Front legs 6 are attached to bottom rails 3 and reinforced by support members 5 to lift the frame 100 at a predetermined angle in the manner to be explained further herein. A mounting device in the form of feet 7 can be welded to the front legs 6 to ensure stability upon impact of a projectile through the inserts 200 . If necessary, additional stability can be obtained by driving long nails or other anchoring spikes into the ground through holes 13 formed into feet 7 .
[0041] The preferred frame consists of both structural angles rectangular bar stock. For the frame to fit inside a standard shipping tube, the components of the frame 100 are connected to one another by machine screws, lock washers, and nuts in a manner known to those in the art. As shown in FIG. 9 , the length of legs 6 causes the frame to be tilted about 15° to 20° from horizontal so that a projectile will penetrate normal to the frontal area. If complete penetration occurs, the projectile will harmlessly entire the ground. It should be understood that the frame 100 can be tilted at any desired angle to suit the weapon and the particular exterior ballistics of the projectile so that the path of travel through the inserts 200 is substantially parallel to the frame 100 .
[0042] A locking device 30 to secure the position of the inserts 200 within the frame 100 is shown in detail in FIG. 3 and preferably comprises a threaded shaft 35 , two metal washers 33 , one rubber flat washer 32 , one hex nut 34 , and one wing nut 31 . Two locking devices 30 resides within respective slots 12 which are formed along the length of side rails 4 . When engaged, locking devices 30 contact the outermost hide simulant insert 300 to prevent movement of the inserts 200 relative to one another.
[0043] The shoulder to shoulder representation of the animal of choice (whitetail deer, elk, grizzly bear, eland or Cape buffalo) is made up of layers of materials to represent their biologic analogs. These biologic analogs will be represented twice, with the exception of the internal organs section, in order to replicate the entire width of the animal. The layers in the preferred embodiment are standardized as a 15″×15″ frontal area. Frontal area may be made smaller as long as the wound cavity does not exceed it. If made too small, then edge effects of the wound cavity would be created, corrupting the results. The thickness of each layer of tissue is a direct correlation to the actual biologic tissues of the big game animals simulated.
[0044] The insert closest to the front of the frame 100 simulates the hide of the animal. As shown in FIGS. 4A and 4B , the hide simulant insert 300 is constructed from a hide frame 301 made of pine boards and a hide simulant 302 made of real or imitation leather. The hide simulant 302 is stretched over the wooden frame 301 and attached with staples 303 . The appropriate thickness of hide should be modeled by layering the hide simulant 302 a specified number of times. For example, Table 1 defines the appropriate number of layers of hide simulant to correlate to the thickness of each animal's hide.
[0000]
TABLE 1
Anatomically Correct Hide Thickness and Required
Number of Hide Simulant Sheets.
Whitetail
Grizzly
Cape
Deer
Elk
Bear
Eland
Buffalo
Animal Hide Thickness (in)
0.25
0.3
0.4
0.3
0.48
No. of Hide Simulant
4
5
6
5
8
Sheets
[0045] The muscle simulant insert 400 , shown in FIG. 5 , is constructed from a molded 15 ″×15″ slab of Corbin SIM-TEST™ ballistic gelatin with a thickness (0.5″-2.0″) appropriate to replicate the muscle thickness of each of the five target species. Corbin SIM-TEST™ is an animal protein based muscle tissue simulation media for bullet performance testing. This material is an extremely close match to muscle tissue in density and consistency. It does not require refrigeration and can also be melted and re-cast an unlimited amount of times.
[0046] Table 2 defines the appropriate thickness of muscle simulant insert to provide a one to one correlation of muscle to the muscle simulant. The numbers in Table 2 are based on one side of the animal. Therefore, two layers of muscle simulant will be needed to simulate the complete width of the animal.
[0000]
TABLE 2
Anatomically Correct Muscle Thickness and Required
Thickness of Muscle Analog
Grizzly
Cape
Thickness (in)
Whitetail Deer
Elk
Bear
Eland
Buffalo
Animal Muscle
0.47
1.21
1.4
1.65
2.08
Muscle Simulant
0.5
1.25
1.5
1.5
2
Insert
[0047] The preferred construction of the bone simulant insert 500 , shown in FIG. 6 , is a fiberglass sheet. The fiberglass sheets are created from a ¾ ounce woven fiber mat and saturated with a 3:1 epoxy hardener. They have a thicknesses range from 0.125″-0.5″. Bone simulant insert 500 properties can be manipulated to the approximate properties of bone by adjusting the epoxy ratio of resin to hardener and the type of the fiber mat used.
[0000]
TABLE 3
Anatomically Correct Bone Thickness and
Required Thickness of Bone Simulant Insert
Whitetail
Grizzly
Cape
Thickness (in)
Deer
Elk
Bear
Eland
Buffalo
Animal Bone
0.125
0.38
0.4
0.4375
0.48
Bone Simulant Insert
0.125
0.4
0.4
0.4
0.5
[0048] The internal organs of the big game animal comprise the majority of the thickness of the distance for the shoulder to shoulder penetration. Internal organs can not be accurately simulated with ballistic gelatin. A unique series of air and water inserts 600 were constructed to match the appropriate thickness and specific gravity of the internal organs of the desired big game animals.
[0049] The internal organs are the most difficult to recreate due to heterogeneity. To simulate heterogeneity, the internal organ simulant inserts 600 are comprised of air inserts 610 ( FIGS. 7A and 7B ) and water inserts 620 ( FIG. 8 ). Air inserts 610 are composed of an air insert frame 611 made from ½″ plywood cut into a 15″×15″×2″ frame and covered with an air membrane or sheet 612 made of visqueen or polyethylene sheet. The air membrane 612 is attached to the air insert frame 611 by staples 613 . Similarly, water inserts 620 are composed of water insert frames 621 made from ½″ plywood cut into a 15″×15″×3.5″ frame with water bags 622 filled with water or other liquid similar in properties to internal organs. The water bags 622 are vacuum sealed bags and constructed with excess material on one end which acts as a tab 623 . The tab 623 is fed through the water bag slot 624 formed into the top of the water insert frame 621 by staples 625 . Drainage holes 626 allow for the water to flow away if the bag 622 is penetrated by the projectile. The purpose of vacuum sealing is to guarantee the specific gravity and to reduce the sag in each water bag 622 . Water bag 622 dimensions are 11″×14.5″ and each is filled with about 1.25 gallons of water to ensure accuracy of the representation. The water inserts 620 and the air inserts 610 may need to be unequal in depth to obtain the proper specific gravity. With the proper geometry and width of the vitals section, each animal can be accurately simulated using these size combinations. Air inserts 610 and water inserts 620 were used in various ratios to obtain a specific gravity of approximately 0.75 which can be seen in Table 4.
[0000]
TABLE 4
Anatomically Correct Internal Organ Thickness and Description of
Required Number of Air Inserts and/or Water Inserts for Internal Organ Analog.
Total
Length
Anatomic
Inserts
(in)
SG
Width
Whitetail
3.5″ W
2″ A
3.5″ W
9
0.78
8.5
Deer
Eland
3.5″ W
2″ A
3.5″ W
2″ A
3.5″ W
14.5
0.72
13
Elk
3.5″ W
2″ A
3.5″ W
2″ A
3.5″ W
2″ A
3.5″ W
20
0.7
20
Grizzly
3.5″ W
2″ A
3.5″ W
3.5″ W
3.5″ W
2″ A
3.5″ W
21.5
0.81
22
bear
Cape
3.5″ W
2″ A
3.5″ W
2″ A
3.5″ W
3.5″ W
2″ A
3.5″ W
23.5
0.74
23
Buffalo
[0050] Although it may be easier not to use the air insert frame 611 for the air insert 610 in the vitals assembly, it serves multiple purposes. The air insert frame 611 serves as a void between components. It also provides a measurement tool in the case that the projectile does not penetrate completely through the vitals section. Lastly, the air membrane 612 provides a visual representation of the damage pattern left behind by the bullet, and it simulates air pockets in the lungs of an actual animal.
[0051] The preferred embodiment of the present invention can be used to accurately recreate any of the five big game animals mentioned previously by placing simulant inserts as listed in Table 5.
[0000]
TABLE 5
Guidelines for Big Game Animal Replication from
Mechanical Analogs for Biologic Materials.
Whitetail
Grizzly
Deer
Elk
Bear
Eland
Cape Buffalo
Hide Sheets
4
5
6
5
8
Muscle Depth (in)
0.5
1.25
1.5
1.5
2
Bone Depth (in)
0.125
0.4
0.4
0.4
0.5
Internal Organs
2 Water
4 Water
5 Water
3 Water
5 Water
1 Air
3 Air
2 Air
2 Air
3 Air
Muscle Depth (in)
0.5
1.25
1.5
1.5
2
Bone Depth (in)
0.125
0.4
0.4
0.4
0.5
Hide Sheets
4
5
6
5
8
[0052] As depicted in FIG. 10 , if the user is only interested in penetration effects on a whitetail deer, the simulator frame 100 can be modified to reduce its length and its weight. This embodiment would entail reducing the length of the bottom rail 3 , side rail 4 , and side support 5 to 15″ by using the whitetail side rail 3 a , whitetail bottom rail 4 a , and whitetail side support 5 a . This frame could also accommodate the smaller insert frames to allow for a less expensive model for experimentation.
[0053] In order to test projectile penetration, the present invention is assembled at the testing area by orienting the frame to the firing position as depicted in FIG. 9 . Using Table 5 as a guide, the inserts of simulants are placed into the frame 100 in order and quantity as listed. For example, to simulate the anatomic representation of a Cape buffalo, a hide layer with 8 sheets of faux leather is placed at the rear of the frame 100 . Then, the muscle simulant insert 400 (in the preferred embodiment a 2″ thick layer) of ballistic gelatin is placed in front of the hide simulant insert 300 . Next, bone simulant insert 500 (in the preferred embodiment, a ½″ layer of fiberglass of the appropriate formulation as previously described) is placed in front of the muscle simulant insert 400 . Then a combination of air inserts 610 and water inserts 620 are inserted in order as defined for the preferred embodiment in Table 4. Now, in reverse order as previously described, a bone simulant insert 500 , then muscle simulant insert 400 , and finally a hide simulant insert 300 are inserted into the frame 100 . The locking device 30 is inserted into each of the slots 12 on side rails 4 to rigidly compress the collection of inserts 200 . In the preferred embodiment, the locking device adds to the usability of the design by allowing the user to quickly and easily conform the invention to the various game widths. Moving the locking device 30 is carried out by loosening the wing nut 31 , which allows the locking device 30 to slide front to back in the slot 12 . Then, by tightening the wing nut 31 back down at the proper location to represent the chosen animal, the collection of inserts 200 is locked in place. Finally, a nail or other anchor can be driven into the ground into the hole 13 to rigidly connect the frame 100 to the ground. Now the user can shoot the projectile toward the center of the hide simulant layer 300 .
[0054] Once the projectile impacts the present invention, the user can observe the rear hide simulant insert 300 to observe if the projectile has penetrated all of the layers of simulants. If complete penetration has not occurred, the user can loosen the wing nut 31 and slide the locking device 30 forward in the slot 12 . Now, the process of observing the effect the projectile imparted onto the inserts 200 can begin. Each insert can be removed from the frame 100 and the depth of penetration can be measured. Also the size of the wound cavity can be observed. With this information, the user can compare the effects of various projectile combinations upon the inserts 200 by replacing damaged inserts with new ones.
[0055] From the foregoing description, a number of advantages of the present invention become evident. First, one can accurately model the effect of projectile penetration from shoulder to shoulder of a big game animal because all component layers replicate the mechanical properties of the biologic materials. Second, no other penetration modeling device accounts for hide or the internal organs of the target. Also, because the inserts are stacked on each other and rigidly constrained by means of the locking device, it is simple to change the orientation of the inserts for a different animal. For the same reasons, it is easy to remove a layer to observe damage caused by the projectile, and to swap layers once a projectile has penetrated them.
[0056] It should also be understood that the present invention can similarly be used for testing of projectile performance for military and law enforcement purposes, inasmuch as the layers may be assembled in a manner to simulate a human torso as well. For example, testing for penetration on ballistics garments (such as so-called “bullet-proof vests”) or protective armor can easily be accomplished via the present invention simply by inserting the appropriate protective material in the front of the various simulant layers, namely the hide simulant insert 300 . For example, the ballistic material may be attached to a frame 301 in the identical manner described for the hide simulant layer 300 and as illustrated in FIGS. 4A and 4B . Thus, even if the projectile fails to penetrate the ballistic garment material, the effects of its impact may be determined by inspection of the trauma or other deformations to the inserts located behind the ballistic material.
[0057] Furthermore, because the frame is constrained to the ground by nails, it will not move upon impact. Because the frame is assembled with bar stock, angle and screws, it is easy to store and ship. Although the assembled model for a Cape buffalo would weigh between 120 and 150 pounds, it is easily transportable because it can be assembled from its parts on site.
[0058] All references cited in this specification are herein incorporated by reference as though each reference was specifically and individually indicated to be incorporated by reference. The citation of any reference is for its disclosure prior to the filing date and should not be construed as an admission that the present invention is not entitled to antedate such reference by virtue of prior invention.
[0059] It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention set forth in the appended claims. 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 device for simulating the torso of an animal or human to determine projectile performance is provided, comprising a support frame; and a plurality of selectively removable simulant inserts, including a hide simulant insert, a muscle simulant insert, a bone simulant insert, and one or more internal organ simulant insert, and wherein the simulant inserts are placed within the support frame in a predetermined order specific to the type of animal or human being simulated. The support frame includes a mounting device to secure the support frame to a ground surface, and a base adapted to orient the support frame at a selectable angle relative to a projectile path. The support frame further includes a locking device adapted to secure the simulant inserts to the support frame. In a preferred embodiment, the locking device includes a fastener slidably disposed within a slot formed in the support frame, and an extended member adapted to contact one of the simulant inserts.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. patent application Ser. No. 08/780,500 filed Jan. 8, 1997.
FIELD OF THE INVENTION
The present invention relates to an arrangement for a drying cylinder in a paper/board machine including a steam/condensate/water coupling.
BACKGROUND OF THE INVENTION
From the current assignee's Finnish Patent No. 90,100 (which corresponds to U.S. Pat. No. 5,230,169, incorporated by reference herein), a steam and condensate coupling in connection with a drying cylinder in a paper machine is known, by means of which coupling a pressure-tight joint is permitted between revolving cylinder parts and connected stationary parts. In the construction disclosed in Finnish Patent No. 90,100, a carbon seal is used and is fitted in an axially displaceable piston part. The piston part is further connected with an annular groove in a fixed support construction. These pieces are rotationally symmetric, and the steam and condensate pipes are passed into the drying cylinder through the central spaces in these pieces. The steam is passed through an inlet connection placed at the end of the steam and condensate coupling so that the steam is made to flow through perforations in the wall of the steam pipe into the interior of the steam pipe and further forward inside the steam pipe and into the cylinder. The condensate pipe is passed centrally in the steam pipe, and condensate and water may be removed through the condensate pipe. Both the steam pipe and the condensate pipe are stationary constructions, and they are supported in a stationary position in relation to the other constructions. The steam pipe and the condensate pipe are passed centrally through the hollow interior space in the cylinder shaft into the interior of the cylinder. In order that the steam is not discharged from the interior of the cylinder and in order that the central passing of the steam and condensate pipes can be permitted, the arrangement comprises the coupling construction described above around the steam and condensate pipes, in which connection the pressure of the steam is fitted to act upon the face of the piston part, and the seal connected with the piston part is pressed by means of the piston part against the end of the shaft or against a part connected with same so as to produce a tight joint. In order that the joint should be tight under all circumstances, there are springs between the piston part and the connected stationary frame. By means of the springs, a force is produced so as to press the seal against the end of the shaft also in the situations in which the pressure in the drying cylinder cannot act upon the piston part.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improvement on the steam and condensate coupling described in Finnish Patent No, 90,100 above. Specifically, in the prior art construction of FI 90,100, the steam and condensate coupling comprises a frame construction in which there is a separate, so-called rotary support, in whose annular groove the piston part is arranged. The end frame of the coupling is connected to this rotary-support frame by means of separate screws and the end frame of the coupling included the inlet connection for steam and the outlet connection for condensate. This construction has proven to be problematic.
It is another object of the present invention to provide a new and improved steam and condensate coupling, in particular, for use in a drying cylinder of a paper or board machine.
In order to achieve these objects, and others, in the arrangement in accordance with the invention, the frame of the steam and condensate coupling consists of one single cast piece, which comprises an outlet connection for condensate or both an outlet connection for condensate and an inlet connection for steam. Further, the frame comprises an annular groove which operates as a sort of a cylinder for the piston part to be situated in the groove, to which piston part a carbon seal or equivalent is attached.
In view of this unique combination of elements, it has been possible to simplify the construction of a steam, condensate or water coupling quite considerably. The construction in accordance with the present invention is a modular part, in which the same basic construction can be used in all steam supply and condensate removing devices provided with a standing syphon irrespective of the machine speed, paper/board grade, or pressure category. The coupling in accordance with the invention is also suitable for use as a water coupling for such modes of operation of a cylinder in which cooling water is passed into the interior of the cylinder so as to cool the cylinder and in which construction compressed air is passed into the cylinder so as to remove the water through an exhaust pipe, preferably a condensate pipe, under pressure out of the interior of the cylinder. The construction in accordance with the invention is also suitable for such embodiments of a condensate removing coupling in which steam is passed into the interior of the cylinder from one end of the cylinder and in which condensate is removed through a coupling in accordance with the invention from the opposite end of the cylinder. Thus, in such a case, the coupling construction comprises just a condensate pipe for removal of water and condensate through a construction in accordance with the invention.
In one embodiment of the invention, the coupling is used for cylinder in a paper/board machine which keeps an interior of the cylinder pressure-tight while permitting rotation of the cylinder. The cylinder has a stationary pipe system leading into the interior of the cylinder through an interior space in a shaft of the cylinder and a bearing housing for supporting the shaft. The coupling frame in accordance with the invention is arranged in connection with an end of the cylinder and includes an exhaust connection coupled to the stationary pipe system and through which condensate or water is removed from the interior of the cylinder, an annular groove, and at least one spring socket. The coupling also includes a piston arranged in the annular groove of the coupling frame and at least one spring arranged in a respective spring socket for pressing the piston against the shaft of the cylinder, each spring being arranged between the piston and a face of the respective spring socket. The coupling is fixed by fastening means to the bearing housing. At times, the piston may include a seal member for providing a seal between the piston and the shaft of the cylinder. The coupling frame may be an integral cast piece or cast from iron so that it constitutes a single piece of cast iron.
In certain embodiments, the coupling frame includes a flange part whereby the fastening means are arranged in connection therewith for directly connecting the coupling frame to one of the bearing housings of the cylinder. As such, the fastening means comprise at least one hole in the flange part and a fastening bolt or screw extending through each hole into engagement with the associated bearing housing of the cylinder. The coupling may also include connecting means for connecting the seal member to the piston, e.g., an annular rib contacting a shoulder of the seal member and screws passing through a respective aperture in the annular rib and into connection with the piston. A U-section or V-section seal ring may be interposed between a face of the seal member situated in opposed relationship to the piston and a face of the piston situated in opposed relationship to the seal member, and rotation prevention means provided for preventing rotation of the piston relative to the coupling frame. In this regard, the rotation prevention means may comprise a key arranged in a hole in the frame and at least partially in an aligned hole in the piston.
The arrangement for a drying cylinder in a paper/board machine in accordance with the invention comprises a stationary steam and condensate coupling including a steam pipe structured and arranged to pass steam into an interior of the drying cylinder, a condensate pipe structured and arranged to remove condensate from the interior of the drying cylinder, and a coupling frame arranged in connection with an end of the cylinder. The coupling frame includes an exhaust connection coupled to the condensate pipe, an annular groove arranged in a face of the coupling frame facing toward the drying cylinder, and at least one spring socket opening into the annular groove. The arrangement also includes a revolving axle arranged at one end of the drying cylinder, the steam and condensate pipes being passed through the axle, a bearing housing for rotatably supporting the axle, a piston arranged in the annular groove of the coupling frame, at least one spring arranged in a respective spring socket to press the piston against a portion of the axle, each spring being arranged between the piston and a face of the respective spring socket, and fastening means for fixing the coupling frame to the bearing housing.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings are illustrative of embodiments of the invention and are not meant to limit the scope of the invention as encompassed by the claims.
FIG. 1A shows a coupling in accordance with the invention in connection with a drying cylinder in a paper machine whereby in order to heat the drying cylinder, steam is introduced through the coupling, and the condensed steam and the condensate are removed from the interior of the drying cylinder through a syphon pipe and a condensate pipe and through the coupling in accordance with the invention.
FIG. 1B shows an embodiment of the invention in which the coupling is operated so that the condensate is removed exclusively through the coupling and whereby steam is passed into the interior of the cylinder through the opposite end of the cylinder.
FIG. 1C shows an embodiment of the invention in which the coupling is used as a water coupling, in which case the cooling water for the cylinder is passed through the coupling, and compressed air is passed into the cylinder through a compressed-air connection mounted in the condensate pipe and water is removed out of the interior of the cylinder.
FIG. 2A is a longitudinal sectional view and an illustration in part of a cylinder and coupling construction in accordance with the invention.
FIG. 2B shows the coupling construction in accordance with the invention on an enlarged scale.
FIG. 2C is a separate illustration of a coupling construction in accordance with the invention with the steam and condensate pipes removed.
FIG. 2D is an exploded view of the seal of the coupling construction shown in FIG. 2C as taken apart from the rest of the construction.
FIG. 2E shows an embodiment of the invention in which the coupling frame comprises an exhaust connection for condensate only in which case, the coupling frame is suitable for embodiments in which only condensate is removed through the coupling, while the steam is passed into the cylinder from the opposite end of the cylinder.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the accompanying drawings wherein the same reference numerals refer to the same or similar elements, FIG. 1A shows a drying cylinder 10 of a paper machine or a board machine, which cylinder is rotated on support of bearing means 17a and into which steam is supplied through an opening 23 in a side face of a frame 21 of a steam/condensate/water coupling 20 in accordance with the invention. Condensate formed in the interior of the drying cylinder 10 is removed from the end of the frame 21 through an opening 22. In its connection, the frame 21 comprises a piston 25 and a seal 28 arranged in association with the piston 25 and operatively pressed against an annular part 29 (and will be described below in greater detail with reference to FIGS. 2A-2E). Seal 28 may be a ceramic seal ring. Part 29 is placed at the end of the rotated shaft 10c (FIG. 2A). The drying cylinder is rotated by suitable rotation means, for example, by the intermediate of a gear wheel 19 (FIG. 2A) by means of a motor, or the drying cylinder may be freely revolving.
FIG. 1B shows an embodiment of the invention in which the coupling 20 in accordance with the invention is used for removal of condensate only. The steam is passed into the interior of the drying cylinder 10 through the opposite end of the drying cylinder 10 (not shown in the drawing) centrally through the shaft, and the condensate is removed through the end of the frame 21 of the coupling 20 in accordance with the invention. Thus, the steam enters the interior of the drying cylinder through one end and condensate is removed from the opposite end.
FIG. 1C shows an embodiment of the invention in which the coupling in accordance with the invention is used as a water coupling for supplying water into the interior of the cylinder 10. In this manner, the cylinder 10 operates as a cooling cylinder. The cooling water is introduced through the frame 21 of the coupling 20 (through a so-called steam connection) and is passed into the interior of the cylinder. The water is removed through the condensate pipe. Along a separate duct, compressed air is passed into the cylinder, and the water is removed through the condensate pipe by means of the air pressure provided inside the cylinder.
From the foregoing, it can be appreciated that the coupling construction in accordance with the invention can be used for the passage of steam into the cylinder or the passage of steam into the cylinder and the removal of condensate from the cylinder or the passage of water into the cylinder and the removal of water therefrom. The most significant change in these embodiments is the component in the central cavity of the support shaft of the cylinder, i.e., a steam pipe or condensate pipe or water pipe. However, the general construction of the coupling construction described below can be used in connection with all of these different steam/water/condensate embodiments.
FIG. 2A is a longitudinal sectional view and an illustration in part of a steam/condensate coupling construction in accordance with the invention. FIG. 2B shows the coupling construction in an enlarged view. As shown in FIGS. 2A and 2B, the drying cylinder 10 of a paper/board machine comprises a mantle 10a and a related end flange 10b, which is further connected with a shaft 10c which includes a hollow interior space C.
In the manner indicated by the arrow L 1 , the steam is passed through the steam pipe 12, along the flow duct placed between the steam pipe 12 and the condensate pipe 11 passing in its interior, into the space E in the interior of the cylinder 10. The condensate pipe 11 is arranged in the interior of the steam pipe 12 and they may be coaxial with one another. After having delivered its heat to the interior of the drying cylinder 10 and specifically to the inner surface of the mantle 10a of the drying cylinder 10, the steam condenses, and the condensate is removed through a syphon pipe 110 connected with the condensate pipe 11 and drawn through the condensate pipe 11 out of the interior of the cylinder 10. The steam pipe 12 is supported on the syphon pipe 110 by means of a support 13 and by means of fastenings 14. Other syphon pipe support structure can also be used without deviating from the scope and spirit of the invention. The steam pipe 12, and the condensate pipe 11 placed in its interior, are passed into the interior of the cylinder 10 through the hollow interior space C in the shaft 10c of the cylinder 10. Between the steam pipe 12 and the hollow interior space in the shaft 10c, there is additionally a shield pipe 15.
The gear housing 16 which supports shaft 10c of the cylinder 10 comprises a bearing housing 17 connected with the gear housing 16 and bearing means 18 arranged in the bearing housing 16, and the cylinder 10 is rotated on support of the bearing means 16 cooperating with the shaft 10c. Further, in the interior of the gear housing 16, there is a gear wheel 19 connected with the shaft 10c, the rotation drive (not shown) being passed or conveyed to the gear wheel 19 so as to rotate the cylinder 10 through rotation of its shaft 10c.
As shown in FIGS. 2A and 2B, according to the invention, the steam/condensate coupling 20 comprises a frame 21, which is a cast piece, preferably a single piece of cast iron. The frame 21 comprises a rear frame portion 21a having an interior in which a steam inlet chamber D is formed (FIG. 1C). A forward frame portion 21b of the frame 21 forms the coupling construction proper, and includes an annular space 24 receivable of a piston 25. The piston 25 moves in the annular space 24. The piston 25 is further connected with the seal 28, which is preferably a carbon seal, which is placed against the revolving shaft 10c or against the part 29 connected with the shaft 10c. Further, the frame 21 comprises a fastening portion 21c, which is preferably a flange-like part, which includes one or more fastening holes 30 for passing respective fastening screws 31 into a separate fastening rib 33, and specifically into its threaded holes 32. The fastening rib 33 can be, for example, a constructional piece directly connected with the bearing housing 17 and made of one cast piece with the bearing housing 17, or it can be a separate constructional part which can be connected with the bearing housing 17. Other fastening means for securely attaching the frame 21 to the bearing housing 17 or an extension thereof can be used in accordance with the invention.
According to the invention, the frame 21 is a unified cast frame, preferably made of cast iron. In the interior of its rear frame portion 21a, the inlet chamber D has been formed for steam. The inlet chamber is a wide chamber space through which the steam pipe 12 is passed, and fluidly connected therewith, and into which bores 12a 1 , 12a 2 . . . or equivalent conduits provided in the steam pipe 12 are opened, the steam being passed out of the space D through the bores or equivalent conduits, in the manner indicated by the arrows L 1 , into the interior of the steam pipe 12 (FIG. 2B). The condensate pipe 11 extends through the space D but does not open therein.
The steam pipe 12 is connected with the end of the frame part 21 and further, by means of a wedge joint, with a conical hole M in the frame 21 at the forward side of the chamber D. A duct 36 opens into the conical hole M and through the duct, pressurized oil may be passed to the vicinity of the conical face during disengagement of the steam pipe 12 from the coupling frame 21. The frame part 21 further comprises an inlet opening 23 for the intake of steam, which opening is opened into the space D and is placed at the side of or in a side face of the frame portion 21a. At the end of the frame portion 21a, there is an exhaust opening 22 for passing the condensate through the opening and out of connection with the frame, preferably through a flow clock 34 or through an equivalent indicator that indicates the flow. The steam pipe 12 is connected by means of fastening means such as screws j 1 with a fastening plate P connected with the frame 21. The condensate exhaust pipe 11' is connected with the frame 21 by means of fastening means such as screws 2. The inner bore in the plate P also operates as a fastening support face, either directly or by the intermediate of the steam pipe, for the end of the condensate pipe 11.
FIG. 2C is a separate illustration showing the frame 21 of the steam/condensate coupling in accordance with the invention, which frame is preferably a cast part. The frame 21 comprises a rear frame portion 21a and a forward frame portion 21b, in whose annular space 24, the piston 25 can be fitted. Springs 26a 1 ,26a 2 . . . are placed in spring sockets 27a 1 , 27a 2 . . . in the frame, which sockets have been divided uniformly around a circle, preferably as evenly spaced, i.e., uniformly, circumferentially spaced about the face of the coupling frame 21 facing the axle or shaft 10c of the cylinder 10. The piston 25 comprises a face 25a inclined in relation to the longitudinal axis (X), upon which face 25a the steam pressure present inside the steam cylinder 10 is fitted to act. As such, the piston 25 is pressed against the end of the rotated shaft 10a or against a part 29 connected with the shaft 10a. In this way, rotation of the cylinder 10 is permitted while the pressurized steam cannot be discharged out of the interior space E in the cylinder 10. The stationary steam and condensate pipes 12,11 can, however, in this construction, be passed into the cylinder 10 from outside the cylinder 10.
The seal 28 is connected with the piston 25 by means of the screws R 1 ,R 2 , . . . while an annular plate L keeps the seal 28 in a recess 25b in the piston. The seal 28 comprises a shoulder 28b, which is placed behind the rib L when the rib L is placed in its position on the piston 25 by means of the screws R 1 ,R 2 , . . .
As shown in FIG. 2C, rotation of the piston 25 is prevented by means of a key F. The key F is fitted into a threaded hole F 2 in the frame 21 with a threading and into a hole F 1 in the piston 25 with a glide fitting. In this manner, gliding of the piston 25 in the direction of the X-axis is permitted. The key F is placed in the hole F 1 in a front face 25' of the piston 25 and in the hole F 2 in the frame 21. A separate seal ring a is placed between the seal 28 and the piston 25 in a ring groove g. The sectional shape of the seal n provided with a spring ring is preferably V-section or U-section, in which case the steam pressure can act upon the interior of the seal n if the pressure has access to the seal. The pressure is effective in the interior of the seal, and the seal n is pressed further against the carbon seal 28 or equivalent. In this manner, access of steam beyond the seal n is also prevented in situations in which the seal 28 proper, preferably a carbon seal, is worn.
FIG. 2D shows the seal 28 unassembled and separate from the rest of the construction and with the steam and condensate pipes 11 and 12 removed. By means of the screws R 1 ,R 2 , the annular rib L, is placed against the shoulder 28b of the seal 28. The seal n is fitted into the annular space g provided in the piston 25. Then, the seal n is placed between the piston 25 and the bottom of the seal 28.
FIG. 2E shows an embodiment of the invention which is suitable for applications of removal of condensate only. In this embodiment, a frame 210 comprises exclusively an outlet opening 22 for the condensate pipe 11. Steam is not passed through the frame 210 into the interior E of the cylinder 10. Rather, the steam is passed into the interior E of the cylinder 10 from one end of the cylinder 10, and the condensate is removed through the frame 21 shown in FIG. 2C through the opposite end of the cylinder 10.
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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An arrangement for a drying cylinder in a paper/board machine including a steam, condensate and/or water coupling. The coupling includes a steam pipe through which steam is passed into an interior of the drying cylinder, a condensate pipe through which condensate is removed from the interior of the drying cylinder, a unitary coupling frame arranged in connection with an end of the cylinder and including an exhaust connection coupled to the condensate pipe, an annular groove arranged in a face of the coupling frame facing toward the drying cylinder, and at least one spring socket opening into the annular groove, the arrangement also includes a revolving axle arranged at one end of the drying cylinder through which the steam and condensate pipes are passed, a bearing housing for rotatably supporting the axle, a piston arranged in the annular groove of the coupling frame, and at least one spring arranged in a respective spring socket of the coupling frame to press the piston against a portion of the axle. Each spring is arranged between the piston and a face of the respective spring socket. Fastening means are provided for fixing the coupling frame to the bearing housing.
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COPYRIGHT STATEMENT
[0001] All of the material in this patent document is subject to copyright protection under the copyright laws of the United States and other countries. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in official governmental records but, otherwise, all other copyright rights whatsoever are reserved.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to a vessel for dispensing steam or moisture into a clothes drying environment, and particularly to a vessel for dispensing steam or moisture to a batch of clothes that has been left in a clothes dryer for a period of time following termination of the drying cycle.
[0003] For many families and individuals, the task of washing and drying clothing, towels, and other articles is ongoing. Quite often, as one batch of clothing articles is completed, another is ready to begin. Even with the aid of advanced washing machines and clothes dryers, washing and drying clothing articles can become an obligation that quickly fills an entire day. Washing and drying cycles for conventional washing machines and clothes dryers can have varied lengths, depending on the size of the batch of clothing articles to be washed and dried. Inevitably, busy families and individuals can lose track of the status of a batch of clothing articles during one of these cycles. As a result, it is not at all uncommon for a batch of clothing articles to sit unattended in a washing machine or clothes dryer following termination of the corresponding cycle.
[0004] In particular, with respect to the drying component of the overall process, a batch of clothing articles that is left unattended following termination of the drying cycle can become wrinkled, matted, or clumped together if left for a prolonged period of time. When this occurs, individual clothing articles may be virtually unusable without being refreshed. In order to refresh the batch of clothing articles following termination of the drying cycle, individuals may consider restarting the drying cycle so as to “fluff” the batch of clothing articles before removal from the clothes dryer. However, such attempts to refresh often do not assist with the removal of wrinkles from individual articles because the batch of clothing articles is already dry. As such, a need exists for a device or method that is capable of refreshing a batch of clothing articles that has been left in a clothes dryer for a period of time following termination of the drying cycle.
[0005] Conventional drying aids, such as dryer sheets and dryer balls, are intended for use in connection with a batch of clothing articles at the beginning of the drying cycle when the clothing articles are still wet from the washing cycle. Dryer sheets typically assist with softening the underlying fabric of the clothing articles and may reduce static between individual clothing articles during the drying cycle. Dryer balls typically facilitate greater air flow between clothing articles during the drying cycle, thereby enhancing the drying process by increasing air circulation in the clothes dryer. However, these conventional drying aids are unable to assist in refreshing or removing wrinkles from a batch of clothing articles that is already dry.
[0006] Therefore, a need exists for improvement in the field of drying aids for conventional clothes dryers, and particularly in connection with refreshing a batch of clothing articles that has been left in a clothes dryer for a period of time following termination of the drying cycle. This, and other needs, is addressed by one or more aspects of the present invention.
SUMMARY OF THE INVENTION
[0007] The present invention includes many aspects and features. Moreover, while many aspects and features relate to, and are described in, the context of dispensing vessels for clothes dryers, the present invention is not limited to use only in connection with dispensing vessels for clothes dryers, as will become apparent from the following summaries and detailed descriptions of aspects, features, and one or more embodiments of the present invention.
[0008] Accordingly, one aspect of the present invention relates to a dispensing vessel for introducing moisture to a clothes drying environment. An exemplary such dispensing vessel includes a core and a cover substantially surrounding the core. In this aspect of the invention, the core is comprised of a sponge-like material for at least temporarily retaining a moistening substance within the core. Additionally, the cover has at least one opening extending through to the core for permitting the release of moisture to the clothes drying environment. As used herein, the term “moisture” may refer to liquids, gases, or combinations thereof.
[0009] In a feature of this aspect of the invention, the dispensing vessel may further include one or more protuberances. Furthermore, each of the one or more protuberances may have a flattened tip.
[0010] Another aspect of the invention relates to a method of using a dispensing vessel for introducing moisture to a clothes drying environment, wherein the dispensing vessel includes a core and a cover substantially surrounding the core. An exemplary such method includes introducing a moistening substance to the core of the dispensing vessel, placing the dispensing vessel in a clothes dryer with a batch of clothing articles, and configuring the clothes dryer to operate at a heat setting. Moisture is released from the core of the dispensing vessel to the clothes drying environment via at least one opening in the cover of the dispensing vessel. As used herein, the phrase “clothing articles” may refer to clothing, towels, accessory garments, or related articles.
[0011] In addition to the aforementioned aspects and features of the present invention, it should be noted that the present invention further encompasses the various possible combinations of such aspects and features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] One or more preferred embodiments of the present invention now will be described in detail with reference to the accompanying drawings, wherein the same elements are referred to with the same reference numerals, and wherein,
[0013] FIG. 1 is a perspective representation of an embodiment of a dispensing vessel in accordance with one or more aspects of the present invention; and
[0014] FIGS. 2-7 are perspective representations of another embodiment of a dispensing vessel in accordance with one or more aspects of the present invention.
DETAILED DESCRIPTION
[0015] As a preliminary matter, it will readily be understood by one having ordinary skill in the relevant art (“Ordinary Artisan”) that the present invention has broad utility and application. Furthermore, any embodiment discussed and identified as being “preferred” is considered to be part of a best mode contemplated for carrying out the present invention. Other embodiments also may be discussed for additional illustrative purposes in providing a full and enabling disclosure of the present invention. Moreover, many embodiments, such as adaptations, variations, modifications, and equivalent arrangements, will be implicitly disclosed by the embodiments described herein and fall within the scope of the present invention.
[0016] Accordingly, while the present invention is described herein in detail in relation to one or more embodiments, it is to be understood that this disclosure is illustrative and exemplary of the present invention, and is made merely for the purposes of providing a full and enabling disclosure of the present invention. The detailed disclosure herein of one or more embodiments is not intended, nor is to be construed, to limit the scope of patent protection afforded the present invention, which scope is to be defined by the claims and the equivalents thereof. It is not intended that the scope of patent protection afforded the present invention be defined by reading into any claim a limitation found herein that does not explicitly appear in the claim itself.
[0017] Thus, for example, any sequence(s) and/or temporal order of steps of various processes or methods that are described herein are illustrative and not restrictive. Accordingly, it should be understood that, although steps of various processes or methods may be shown and described as being in a sequence or temporal order, the steps of any such processes or methods are not limited to being carried out in any particular sequence or order, absent an indication otherwise. Indeed, the steps in such processes or methods generally may be carried out in various different sequences and orders while still falling within the scope of the present invention. Accordingly, it is intended that the scope of patent protection afforded the present invention is to be defined by the appended claims rather than the description set forth herein.
[0018] Additionally, it is important to note that each term used herein refers to that which the Ordinary Artisan would understand such term to mean based on the contextual use of such term herein. To the extent that the meaning of a term used herein—as understood by the Ordinary Artisan based on the contextual use of such term—differs in any way from any particular dictionary definition of such term, it is intended that the meaning of the term as understood by the Ordinary Artisan should prevail.
[0019] Furthermore, it is important to note that, as used herein, “a” and “an” each generally denotes “at least one,” but does not exclude a plurality unless the contextual use dictates otherwise. Thus, reference to “a picnic basket having an apple” describes “a picnic basket having at least one apple” as well as “a picnic basket having apples.” In contrast, reference to “a picnic basket having a single apple” describes “a picnic basket having only one apple.”
[0020] When used herein to join a list of items, “or” denotes “at least one of the items,” but does not exclude a plurality of items of the list. Thus, reference to “a picnic basket having cheese or crackers” describes “a picnic basket having cheese without crackers”, “a picnic basket having crackers without cheese”, and “a picnic basket having both cheese and crackers.” Finally, when used herein to join a list of items, “and” denotes “all of the items of the list.” Thus, reference to “a picnic basket having cheese and crackers” describes “a picnic basket having cheese, wherein the picnic basket further has crackers,” as well as describes “a picnic basket having crackers, wherein the picnic basket further has cheese.”
[0021] As used herein, the specific term “moisture” may refer to liquids, gases, or combinations thereof. Additionally, as used herein, the specific phrase “clothing articles” may refer to clothing, towels, accessory garments, or related articles.
[0022] Referring now to the drawings, one or more preferred embodiments of the present invention are next described. The following description of one or more preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its implementations, or uses.
[0023] Turning now to FIG. 1 , an embodiment of a dispensing vessel 10 in accordance with one or more aspects of the present invention is shown. The dispensing vessel 10 includes a core 12 and a cover 14 . The core 12 is preferably composed of a sponge-like material that is capable of absorbing and at least temporarily retaining a moistening substance. The cover 14 substantially surrounds the core 12 and includes at least one opening 16 that extends through to the core 12 of the dispensing vessel 10 . As will be explained in greater detail below, when the dispensing vessel 10 is in use in a clothes drying environment, moisture is permitted to pass from the core 12 to the clothes drying environment via the at least one opening 16 .
[0024] As shown in FIG. 1 , the cover 14 of the dispensing vessel 10 may have a generally spherical shape, thereby providing the dispensing vessel 10 itself with a generally spherical shape. Although a spherical shape is shown, other shapes are also contemplated, such as an oblong shape or a cube shape. The cover 14 of the dispensing vessel 10 may be composed of any material that might be preferred. Advantageously, the cover 14 may be composed of a durable material that is capable of withstanding the high heat typically associated with conventional clothes dryers, such as a durable plastic or rubber material. The cover 14 may also be configured to have a rigid or semi-rigid character. The core 12 may be composed of any material that provides the ability to retain a moistening substance at least temporarily, such as a sponge or sponge-like material.
[0025] As further shown in FIG. 1 , the dispensing vessel 10 may include a fill opening 22 to provide an entry portal through which a moistening substance may be added to the core 12 . The fill opening 22 may be any particular size as might be preferred. Advantageously, the fill opening 22 is sufficiently large so as to permit the core 12 of the dispensing vessel 10 to be removed or replaced. Removal or replacement of the core 12 may become necessary following repeated usage of the dispensing vessel or if the material comprising the core 12 becomes soiled or worn. A cap or lid (not shown) may also be included so as to provide a means of selectively sealing the fill opening 22 after the moistening substance is added to the core 12 . The moistening substance may be any particular substance that can be added to the core 12 in order to provide moisture. Preferably, the moistening substance is a liquid that may be poured into the dispensing vessel 10 through the fill opening 22 to the core 12 . As the dispensing vessel 10 is filled, the sponge-like material of the core 12 absorbs and at least temporarily retains the moistening substance. Additives may be included in the moistening substance to convey desired properties thereto as might be preferred. For instance, a scented substance may be added to the moisturizing substance so as to add a desired scent.
[0026] As further shown in FIG. 1 , at least one opening 16 may be arranged on the cover 14 , that extends through to the core 12 of the dispensing vessel 10 . While any number of openings 16 may be incorporated in the dispensing vessel 10 , FIG. 1 depicts a plurality of openings 16 spaced along the cover 14 at relatively even intervals. The size of the at least one opening 16 may vary. Preferably, the size of the at least one opening 16 is not so large as to permit immediate spillage of the moistening substance from the core 12 . Advantageously, it is also within the scope of the present invention not to include openings 16 opposite of the fill opening 22 . In this regard, the moistening substance added to the core 12 through the fill opening 22 is less likely to seep out of the dispensing vessel 10 prior to use.
[0027] In a method of use of the dispensing vessel 10 , a moistening substance may be introduced to the core 12 through the fill opening 22 . If a cap or lid is present, the cap or lid may be affixed to the cover 14 so as to seal the fill opening 22 , thereby helping to prevent spillage of the moistening substance. The moistening substance is absorbed and at least temporarily retained by the sponge-like material of the core 12 . Optionally, an additive may be included in the moistening substance or added to the core 12 separately in order to provide the moistening substance with a desired property, such as a specific scent. The filled dispensing vessel 10 may then be placed in a clothes dryer with a batch of clothing articles. In a preferred aspect of the method, the batch of clothing articles has previously completed a drying cycle in the clothes dryer and has been left in the clothes dryer for a period of time following termination of the drying cycle, after which time the batch of clothing articles may have become wrinkled, matted, or clumped together.
[0028] Following placement of the filled dispensing vessel 10 in the clothes dryer, the clothes dryer is configured to a drying cycle with a heat setting. During the drying cycle, moisture is released from the core 12 of the dispensing vessel 10 to the clothes drying environment through the at least one opening 16 in the cover 14 of the dispensing vessel 10 . Moisture from the dispensing vessel 10 thereby assists with the removal of wrinkles from individual articles in the batch of clothing articles. Additionally, if a scented additive is included with the moistening substance, the dispensing vessel may simultaneously impart the desired scent to the batch of clothing articles in the clothes dryer, which may further refresh the batch of clothing articles. In a preferred aspect of the method, a high level of heat from the drying cycle of the clothes dryer may facilitate moisture being released from the dispensing vessel 10 as steam, which may enhance the removal of wrinkles. Additionally, a plurality of dispensing vessels 10 may be used simultaneously in connection with a large batch of clothing articles.
[0029] The dispensing vessel 10 may thus be used to provide moisture to the clothes drying environment. Use of the dispensing vessel 10 may assist with the removal of wrinkles from a batch of clothing articles and otherwise refresh the batch of clothing articles following termination of the drying cycle.
[0030] Turning now to FIGS. 2-7 , another embodiment of a dispensing vessel 110 in accordance with one or more aspects of the present invention is shown. The dispensing vessel 110 may include one or more protuberances 18 . The one or more protuberances may be formed as an integral component of the cover 14 , as specifically set forth in FIGS. 2-7 , or the one or more protuberances may be attached to the cover 14 as separate, individual components. As separate components, individual protuberances may be replaced as needed if damage occurs or if differently shaped protuberances are desired. As with the cover 14 , the composition of the protuberances 18 may vary. Advantageously, the one or more protuberances 18 are each composed of a durable material that is capable of withstanding the high heat typically associated with conventional clothes dryers, such as a durable plastic or rubber material. Preferably, the one or more protuberances 18 are composed of the same material as the cover 14 .
[0031] The one or more protuberances 18 may be shaped so as to facilitate air flow between clothing articles in a clothes drying environment, such as a conventional clothes dryer. As shown in FIGS. 2-7 , the one or more protuberances 18 may be generally evenly spaced on the cover 14 of the dispensing vessel 10 . During use of the dispensing vessel 110 in a clothes dryer, the one or more protuberances 18 help to lift and separate individual clothing articles, thereby assisting with airflow between and among individual clothing articles in the clothes drying environment. Enhancing the airflow in the clothes drying environment permits moisture released from the dispensing vessel to be dispersed more evenly in a batch of clothing articles, which thereby enhances the effectiveness of the dispensing vessel 110 in removing wrinkles from individual clothing articles.
[0032] As shown in FIGS. 2-7 , each of the one or more protuberances 18 may be shaped as a chunky knob that extends outwardly away from the cover 14 with a flattened tip 20 at an end thereof. The chunky shape and the flattened tip 20 of the one or more protuberances 18 may enhance lifting and separating of individual clothing articles in a batch of clothing articles. In particular, the chunky shape and flattened tip 20 may loosen a matted or clumped batch of clothing articles that may have been left in the clothes dryer for a lengthy period of time following termination of an initial drying cycle. During use of the dispensing vessel 110 , the flattened tip 20 of the one or more protuberances 18 impacts and bangs into individual clothing articles to loosen and separate a matted or clumped batch of clothing articles, which thereby provides enhanced airflow to the clothes drying environment.
[0033] Other shapes, quantities, and arrangements of the one or more protuberances 18 are contemplated. For instance, at least some of the one or more protuberances 18 may have a generally conical shape. Selection of the shape, quantity, and arrangement of the one or more protuberances 18 may vary on the basis of the type or quantity of individual clothing articles to be refreshed. It is also within the scope of the present invention for some of the protuberances to a have a different shape than other protuberances of a single dispensing vessel 110 .
[0034] As shown in FIGS. 2-7 , which depict the one or more protuberances 18 as being integral with the cover 14 , some of the one or more protuberances 18 may have an opening 17 that extends through to the core 12 of the dispensing vessel 110 . During use of the dispensing vessel 110 , moisture may be released from the core 12 of the dispensing vessel 10 to the clothes drying environment through the openings 16 in the cover 14 and the openings 17 in the one or more protuberances 18 . Moisture from the dispensing vessel 10 thereby assists with the removal of wrinkles from individual articles in the batch of clothing articles. It is further contemplated that the dispensing vessel 110 may have openings 16 in the cover 14 without having openings 17 in the one or more protuberances 18 , and vice versa. Further, as specifically shown in FIGS. 6-7 , it is also within the scope of the present invention not to include openings 16 , 17 opposite of the fill opening 22 . In this regard, the moistening substance added to the core 12 through the fill opening 22 is less likely to seep out of the dispensing vessel 10 prior to use. Further still, if the protuberances are attachable to the cover 14 as separate, individual components, some of the protuberances may include an opening that extends through the protuberance. The openings of these protuberances may be aligned with one or more of the openings 16 of the cover 14 so as to establish a channel through which moisture may be released from the core 12 into the clothes drying environment.
[0035] Based on the foregoing description, it will be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those specifically described herein, as well as many variations, modifications, and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing descriptions thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to one or more preferred embodiments, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for the purpose of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended to be construed to limit the present invention or otherwise exclude any such other embodiments, adaptations, variations, modifications or equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.
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A dispensing vessel for introducing moisture to a clothes drying environment includes a core and a cover substantially surrounding the core. The core is comprised of a sponge-like material for retaining a moistening substance within the core, and the cover has at least one opening extending through to the core for permitting the release of moisture to the clothes drying environment.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to design and operation of high-frequency clocked digital circuit systems, and in particular to method and system for reducing delta I-noise in said digital circuit system.
[0002] The operation speed of today's computer systems approach sub-nanosecond cycle times. The average switching activity and therefore the average power supply current I demand can fluctuate, i.e., change within few nanoseconds. E.g., delta-I=140A current fluctuation of the average power supply current is typical for the multiprocessor multi-chip module of the prior art IBM zSeries 900 system. The fluctuation of the average current demand can be periodic or non-periodic. Due to the parasitic inductance along the power distribution path from the power supply to the individual chips the on-chip power supply voltage deviates temporarily from its nominal level in reaction of a switching activity change. The expression “fluctuation” is used in here for denoting the rise or drop of a physical quantity, such as current I or supply voltage U, whereas the term “change” will be primarily used for denoting a status transition associated with a given activity unit on the chip, e.g., from “switching” to “quiet”. These power supply voltage deviations are called high- and mid-frequency delta-I noise.
[0003] In order to reduce the power supply delta-I noise, decoupling capacitors are placed in prior art along the power supply path, on chips, modules, cards and boards. These decoupling capacitors can sink and source extra current and thus reduce the impact of delta-I on the power supply voltage. However, the decoupling capacitors and all parasitic partial inductance of the power supply path also create resonance loops having various resonance frequencies, which may increase the delta-I noise, if a resonance frequency and the frequency of a periodic switching change coincide. This prior art is described in H. B. Bakoglu, “Circuits, Interconnections, and Packaging for VLSI”, Addison-Wesley Publishing Company, 1990, pp. 303-325, or in W. D. Becker, et al, “Modeling, Simulation and Measurement of Mid-Frequency Simultaneous Switching Noise in Computer Systems”, IEEE Trans. Compon., Packaging, and Manuf. Technol., Part B: Advanced Packaging , vol. 21, no. 2, pp. 157-163, May 1998, or in D. Herrell, B. Beker, “Power system design for high performance PC microprocessors”, IEEE International Workshop on Chip-Package Codesign CPD'98, pp. 46-47, 1998.
[0004] Delta-I noise is one contribution to the overall power supply noise budget and can jeopardize system function and reliability.
[0005] [0005]FIG. 1 is intended to illustrate the general problem. It shows the on-chip power supply noise voltage after starting operation, i.e., switching with 1 nanosecond (ns) cycle time, and 140 A average power supply current, which represents a delta-I current step from 0 A to 140 A. The power supply voltage behavior has been obtained by simulation and confirmed by measurements, see B. Garben, M. F. McAllister, “Novel Methodology for Mid-Frequency Delta-I Noise Analysis of Complex Computer System Boards and Verification by Measurements”, IEEE 9th Topical Meeting on Electrical Performance of Electronic Packaging, pp. 69-72, 2000. High frequency noise (1 ns period) and mid frequency noise (132 ns period) are superimposed. The actual on-chip power supply voltage behaves the same around the nominal voltage level (e.g. 1.2V).
[0006] The damped mid-frequency oscillation with initially 57 mV peak on-chip power supply voltage noise is caused by the resonant loop consisting of all on-module capacitors, i.e., on-module power supply decoupling capacitors plus capacitance of all chips, all board decoupling capacitors and the effective power supply path loop inductance between the two sets of capacitors.
[0007] With reference to Plot a) of FIG. 2 the on-chip power supply noise voltage of the same packaging arrangement is shown, but now, switching and non-switching depicted as “quiet”-time slots repeat every 66 ns. The delta-I repetition rate coincides with the package resonance of 132 ns. The peak on-chip power supply delta-I noise equals 74 mV during the 1st quiet time slot and increases to 103 mV during the 2nd quiet time slot. Both peak noise values exceed the 57 mV, seen during a single switching activity change. The peak mid-frequency on-chip power supply delta-I noise during periodic activity changes saturates at approx. 135 mV beyond 8 periods.
[0008] The saturated peak on-chip mid-frequency delta-I noise increases with increasing conductivity within the resonance loop. E.g. if the overall conductivity within the loop is doubled, the maximum on-chip noise reaches 202 mV after 10 periodic switching activity changes without any saturation tendency (FIG. 2, curve b). This example demonstrates how the peak on-chip power supply voltage noise of periodic/repeated activity changes can significantly exceed the peak values of a single activity change.
[0009] In prior art, high performance computer systems such as the IBM zSeries 900 apply the following technical features in order to damp the delta I-noise:
[0010] 1. many decoupling capacitors on chips, on the Multi-Chip-Module (MCM) and on the board close to the MCM,
[0011] 2. sandwiching of VDD and GND planes closely to each other, in cards and boards to provide a low effective power supply loop inductance.
[0012] However, these design efforts also reduce the effective resistance of the resonant loop and therefore increase the power supply delta-I noise sensitivity in case of a resonance condition.
[0013] Delta-I noise and its increase due to resonant effects is considered in the system noise budget and in signal timing calculations. The following two theoretical approaches are considered today to account for large non-periodic switching activity changes, whereas periodic activity changes are not regarded at all:
[0014] First, an increase of the chip operation voltage allowing shorter cycle times to avoid resonance. This, however, implies more power dissipation, which is not desired at all.
[0015] Second, stretching the system cycle time to avoid resonance. This however reduces the system performance, which also is not desired.
BRIEF SUMMARY OF THE INVENTION
[0016] It is thus an objective of the present invention to provide a method and system for reducing delta I-noise in digital circuit systems.
[0017] According to the broadest aspect of the present invention a method and respective system is disclosed in a general approach for reducing delta-I noise in a digital circuit system comprised of a plurality of activity units being connected to a DC-supply voltage, in which method and system respectively, the operation of said digital circuit system may excite high-frequency fluctuations of a total supply current I (delta-I), and a respective resulting fluctuation of the supply voltage. Said method is characterized by the steps of:
[0018] a) maintaining a circuit system-specific catalogue storing the current consumption and delta-I for each of said activity units in its operational state,
[0019] b) continuously monitoring the actual current consumption of the total of said activity units,
[0020] c) determining critical operation conditions to be caused by an immediately imminent excess fluctuation of the supply voltage resulting from an immediately imminent delta-I demand, the excess quantity being defined relative to a predetermined set tolerance band for the total current I,
[0021] d) dependent of the quantity of the imminent delta-I demand selecting a subset of said activity units with a respective current delta-I demand, for either
[0022] aa) temporarily delaying their begin of activity in case of an imminent supply voltage drop, or
[0023] bb) temporarily continuing their activity with a predetermined, activity-specific No-Operation (NO-OP) phase in case of an imminent supply voltage rise.
[0024] During the physical system packaging design various power supply loop resonance frequencies (f_crit), the corresponding critical duty factor ranges (T=1/f_crit) and a maximum allowed single total delta-I demand (i_crit) value are determined by simulation and are coded into a system specific catalogue, i.e., “data base (SSDB)”, then the critical excess voltage states, i.e., dropdowns, and rise peaks, can be supervised and avoided.
[0025] According to the present invention, throughout the system all major power consuming sub-units, i.e., said activity units, referred to herein as AU, mentioned above, which might be one chip or portion of a chip, or a group of activity units, contain a control element, referred to herein as CE, for monitoring and controlling the actual switching activity within the unit. The control element can force switching activity start delays and NO-OP (dummy) cycles on request within the AU. According to the invention all control elements and thus all sub-units are coordinated by a supervising unit, referred to herein as SU, in a way, which avoids overall periodic switching activity changes of the above mentioned plurality of critical resonance frequencies f_crit and keeps non-periodic switching activity changes and thus delta-I values below i_crit.
[0026] According to the invention there may be basically one supervising unit throughout the system to coordinate the change of total power consumption, or the system is split into several power domains having several supervising units. The SU decisions are based on the system specific data base. The SU can grant AUs having an actually active state to switch into a “quiet” state and vice versa while keeping the overall system switching activity state change within particular predetermined bounds.
[0027] This basic controlling scheme is permanently used to control the delta-I power supply noise, in particular during system power-on, system test and during general system operation. This approach allows to operate systems, which would not be functional/reliable without this control.
[0028] The controlling scheme can also be used to guide the overall system activity to a mode where functional, delayed and NO-OP switching activities are interlaced or anti-cycled in a way, that the delta-I noise is actively damped. This is described in more detail below with reference to FIG. 5 curve b.
[0029] The above mentioned general approach thus basically needs:
[0030] a kind of supervisor unit performing steps a) to d) and communication between each AU and the supervisor unit which transfers the actual information ON/OFF for each activity unit. Thus, a damped delta-I-fluctuation behavior and thus a nearly constant supply voltage can be obtained over time.
[0031] Said general approach thus covers more than the more preferred particular request/grant approach which is a special case of the general approach. The delta in generality can be seen in the fact that the general approach includes solutions in which the AUs are treated as immediate command receivers, which must sometimes halt their operation even in cases in which this seems not adequate for sake of system performance.
[0032] The request grant approach assures that once an AU has begun operation it can continue operation until this is finished. Thus, a weaker intervention to the existing, finely balanced instruction handling in the chip circuit is done, which results in more performance compared to the general approach.
[0033] The basic method mentioned before, may be further improved, by further comprising a request/grant mechanism between a supervisor means and each of said activity units, whereby the mechanism comprises the steps of:
[0034] a) an activity unit requesting that its operation is required to begin (Go-request),
[0035] b) granting the request when this is compliant to the predetermined tolerance band, otherwise not granting said request,
[0036] c) on a successful grant, beginning operation of the AU,
[0037] d) an activity unit requesting that operation is required to stop (STOP-request),
[0038] e) granting the STOP-request when the respective stop of activity operation is compliant to the tolerance band, otherwise not granting said request,
[0039] f) on a successful grant, stopping the operation of the AU.
[0040] Here, the advantage is that the degree of intervention with the actual operational (functional) chip logic is quite small which results in robust control and improved circuit performance.
[0041] In other words, a method is described to reduce delta-I noise and guarantee safe digital system operation despite of critically periodic switching activity changes and/or large non-periodic switching activity changes of CMOS chips, e.g. microprocessors, storage arrangements.
[0042] The system operation jeopardizing critical conditions are identified by simulation during the physical system packaging design. According to the invention, during system operation the actual switching activity is continuously monitored. In case of a critical, imminent condition built-up, i.e., an excess fluctuation can be identified to be immediately expected, then additional non-switching or switching cycles are executed to de-escalate the critical condition. This approach allows to build and operate systems, which would not be functional and reliable without this control.
[0043] The following structural features are disclosed:
[0044] A digital circuit system comprised of a plurality of activity units being connected to a DC-supply voltage, the operation of which may excite high-frequency fluctuations of a total current I, and a respective resulting fluctuation of the supply voltage, is characterized by digital circuit means implemented for performing the steps of the method mentioned before.
[0045] In particular, the digital circuit system may be preferably characterized by the facts that
[0046] a) a subset of said activity units comprises a control element for issuing a STOP or GO request and for receiving a respective grant, whereby said grant triggers a begin and stop of operation of said activity units,
[0047] b) a supervisor control circuit is connected to said control elements via respective control signal lines or other communication means.
[0048] When the digital circuit system comprises a hard-wired request-grant wiring, then the advantage is that a very robust and high speed signaling scheme is obtained.
[0049] An activity unit may preferably be one of or a group of the following circuit functional elements:
[0050] a processor unit, an Arithmetic and Logical Unit (ALU), an adder stage, a multiplier stage, a bus multiplexer stage, a memory array, a switching stage, a clock tree, Input/Output (I/O) driver unit, or an analogue circuit component, in particular a current source. Of course, the composition of a group my be organized such that closely related working units are comprised of one group, which produce e.g., an intermediate result which is further input in a working unit associated with a different group.
[0051] An example for a group is an adder plus an adder output comparing stage.
[0052] Thus, an easy and robust calculating can be obtained when useful grouping of activity units is done.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0053] These and other objects will be apparent to one skilled in the art from the following detailed description of the invention taken in conjunction with the accompanying drawings in which:
[0054] [0054]FIG. 1 is a time chart showing noise voltage on a prior art chip, immediately after start of switching operation, at t=0 nanoseconds (ns);
[0055] [0055]FIG. 2 is a time chart extending until t>1200 nanoseconds, illustrating delta-I repetition frequency of 7.58 MHz, duty cycle of 0.5 in a prior art chip;
[0056] [0056]FIG. 3 is a schematic representation illustrating the basic structural elements of the present invention;
[0057] [0057]FIG. 4 is a block diagram representation of the control flow of a preferred embodiment of the method; and
[0058] [0058]FIG. 5 is a time chart according to FIG. 1, illustrating in
[0059] a) prior art undamped noise voltage; and
[0060] b) noise voltage damped according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0061] With general reference to the figures and with special reference now to FIG. 3 a zoom-view into the logical scheme representation of a prior art chip is given which is improved by the present invention.
[0062] A CMOS chip which is depicted in parts only as a digital circuit system 6 , has a DC power supply device 8 , which is connected between the two DC potential layers VDD at 2 Volts and VSS at 0 Volts, for sake of example only.
[0063] Using the current demand from the power supply 8 during operation the CMOS system is split into a plurality of activity units (AU) 10 A, 10 B, of which only two are depicted for sake of improved clarity of the drawing. Each of said activity units 10 is thus connected to said power supply device 8 .
[0064] In addition to the activity units 10 there is provided a supervising logic circuit 12 throughout the system (SU) according to this preferred embodiment. This supervisor circuit 12 comprises a central activity monitor 13 and a data base 14 abbreviated herein as SSDB and operatively connected with said activity monitor 13 , and containing all critical frequencies f_crit and critical currents fluctuations i_crit to be avoided which was mentioned above. Said critical i_crit were loaded into the database before, as described earlier.
[0065] According to the embodiment given here, each activity unit 10 A, 10 B, etc. is connected to and communicates to a respective control element 11 A, 11 B, etc.
[0066] The operational state of each AU 10 can be active, which implies current demand from the power supply, or inactive, which means no switching activity and therefore implies only a negligible current I demand from the power supply.
[0067] According to a preferred aspect of the invention a request/grant signaling scheme is implemented between each control element 11 A, 11 B and associated activity unit 10 A, 10 B and the activity monitor 12 , respectively.
[0068] A preferred control flow of said signaling scheme will be described next as follows:
[0069] Before an AU is may change its actual state, it has to send a respective request to the AM. This request issuing task is handled by the associated CE. The AU is forced by the CE to delay its intended state change until the AM grants the respective request. The delay/grant algorithm of the AM is using the critical operation data stored in the above mentioned database 14 . Due to the fact that the algorithm is also fed with the actual operation data, i.e., knows about the actual frequencies of delta I-step repetitions (as described above with ref. to FIG. 2) compares between actual operational frequencies and “forbidden” critical frequencies can be done. Such compare processes are performed quite quick, such that the delay/grant algorithm assures that critical activity change frequencies are avoided that the system activity change rate may be kept below a critical limit defined in the database.
[0070] This compare and evaluation step is preferably implemented in hard-wired logic. A preferred implementation for the database 14 logic is one in which all possible system state transitions are mapped into an unique address, which is used to access a memory location including at least a “grant/no-grant” bit in a respective storage array. When a number of 10 AUs are present in the system, a need of 10 exp 2=1024 storage locations arises in this specific embodiment. Of course, other implementations are possible.
[0071] According to a preferred aspect of the present invention each AU 10 is also able to operate in no-op cycles in order to maintain its active state and current demand from the power supply, and—of course—without destroying the final result of the last functional operation. This is achieved by operating the AU in its respective “neutral” state of operation. This is adding a “0” for an adder stage, or multiplying with a factor of “1” in a multiplier stage, etc.
[0072] The status of such dummy operations is preferably entered autonomously by a respective AU in order to guarantee continuous operation having a continuous current demand, until a respective request grant is received in the AU. Thus, each AU 10 is able to delay the transition from its active to its inactive stage, in particular.
[0073] Thus, e.g., if the AU is a multiplier stage, which is able to multiply 2 numbers and transfer the result to the output, the inactive state lasts as long as there are no valid inputs available. If both inputs are valid and the multiplier is allowed to operate, it changes to its active state and does the multiplication. The multiplier transfers the final result to the output and, if allowed, changes its state back to inactive. If the state change to inactive is not granted, it continues to multiply the same numbers or dummy numbers, again and again without updating the output until the grant is given. In cases, in which no neutral operation is possible for an activity unit, and the operation is continued although the original, functionally intended result is already present at the output of the AU, a specific control logic Add-On is provided according to the invention which bypasses the output latches holding the correct result values, in order to avoid an overwrite of the correct result.
[0074] With reference to FIG. 4, which illustrates the control flow of a preferred embodiment of the method, in a step 410 the electrical current consumption of each AU is monitored, and, by addition of them, the cumulated current consumption is monitored. This is done by tracking, which AU is actually in an active state and by performing a cross-check into the database 14 in order to read its nominal current consumption.
[0075] By comparing all actually imminent AU state change requests, and comparing them to the stored critical delta-I value, step 420 , it can be determined, if the system operation is in a critical condition, or not. If the tolerance band is exceeded, the critical operation status would be entered, step 430 . This shall be avoided by virtue of the invention.
[0076] If the evaluation step 430 yields a decision that a negative excess, i.e., an supply voltage drop due to excess current consumption is imminent, i.e. would be reached in the immediate future if the method was not present, then the YES case of decision 440 is entered. In this branch, any AU or at least a sufficiently large number of them should immediately stop work as an supply voltage drop due to “overload” must be avoided. Thus, any incoming “GO-request” issued by any AU which wishes to start operation by this request, is refused, block 452 , whereas a contrary request, i.e., a STOP request is immediately granted, as soon as received, block 454 .
[0077] In the NO-branch of decision 440 the control aim is inverse:
[0078] Any AU should immediately begin work as an excess supply voltage rise due to “underload” must be avoided. Respective contrary control actions are undertaken in a block 462 to refuse a STOP request or to grant, block 464 , a GO-request, respectively.
[0079] Then, it is branched back to step 410 , for continuing the permanent control.
[0080] It should be understood that the frequency with which the loop 410 to 464 is run through, should be in a reasonable ratio to the maximum expectable sum of supply current change request grants. A modification may thus be implemented in which one loop comprises the sampling of more than one request coming in at decided upon in decision 440 .
[0081] [0081]FIG. 5 shows an example in which the advantageous technical damping effect obtainable by the present invention is clearly visualized.
[0082] Two switching periods (1 GHz switching) and two quiet periods are depicted. Curve a) shows a critical case with a first switching period from 0 ns to 66 ns followed by a quiet period for 66 ns, and followed by a second switching period from 132 ns to 198 ns, followed in turn by no switching up to 400 ns.
[0083] In FIG. 5, curve b) the second switching period has been delayed according to the invention by 66 ns to the time period starting from 198 ns and ending at 264 ns. The noise after 132 ns is thus significantly reduced, which reveals from the upper line in the 132 to 198 ns interval.
[0084] Moreover, according to the invention, additional switching (dummy) cycles can be executed to avoid the large noise peak during the first quiet period between 66 ns and 132 ns in either of FIGS. 2 and 5.
[0085] The execution of said additional non-switching cycles (duration T/2 which equals 66 ns in the example) does not reduce the system performance significantly, as long as the repetition time for the critical switching condition is large compared with T/2, which is very likely. On the other hand, any probability for the critical switching condition as e.g. 1 per hour, 1 per day or 1 per week is certainly not tolerable, if this causes a system failure.
[0086] The monitoring of the switching activity will need some additional circuits on the chips. This is however tolerable in regard to the advantageous delta I-noise reduction obtainable thereby.
[0087] The present invention has increasing importance for:
[0088] A) Decreasing chip operation voltage, as the power/ground noise is even more critical at low power supply voltages
[0089] B) Increasing switching (clock) frequencies which increases the power supply current and delta-I noise,
[0090] C) Increasing power supply currents and larger delta-I steps due to more simultaneously switching circuits which increases delta-I noise,
[0091] D) Decreasing capacitor and board/card power/ground plane resistance as a consequence of the above items 1-3, which in turn increases the delta-I noise in case of resonance.
[0092] The present invention can be realized in hardware, or a combination of hardware and software, i.e., in form of a dedicated microcode-programmed processor. A fast solution, however, is preferably implemented with hard-wired logic on the same chip in which the original functional logic is implemented.
[0093] While the preferred embodiment of the invention has been illustrated and described herein, it is to be understood that the invention is not limited to the precise construction herein disclosed, and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims.
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A method, digital circuit system and program product for reducing delta-I noise in a plurality of activity units connected to a common DC-supply voltage. In order to smooth the fluctuations (delta-I) of a total current demand I, and a respective resulting fluctuation of the supply voltage, a signalling scheme between said activity units and a supervisor unit which holds a system-specific “database” containing at least the current demand of each activity unit device when operating regularly. Dependent of the quantity of calculated, imminent delta-I a subset of said activity units with a respective current I demand is selected and controlled, for either temporarily delaying their beginning of activity in case of an imminent supply voltage drop, or temporarily continuing their activity with a predetermined, activity-specific NO-OP phase in case of an imminent supply voltage rise.
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BACKGROUND OF THE INVENTION
The present invention relates to fully automatic method and apparatus for assembling stick-type cosmetics, and more particularly relates to a system which carries out assemblage of stick-type cosmetics such as lipsticks in a fully automatic fashion.
Although the present invention is well applicable to all sorts of stick-type cosmetics, the following description is mainly focussed on application to lipsticks for conveniency purposes.
A lipstick is in general made up of a stick, a bottle and a cap which have to be assembled together for production. Assemblage of a lipstick is conventionally carried out by manual operations. In the manual production, colour-adjusted material paste is charged into stick holes of a split mould, sticks are taken out of the split mould after solidification by cooling, each stick is inserted into a bottle at the tail end, the stick is subjected to flaming in order to remove surface finger prints and/or crests formed by moulding and a cap is inserted over the bottle after withdrawal of the stick into the bottle.
Such a conventional manual assemblage requires a great deal of manual labour and redundant operations such as flaming. In addition, it is not preferable from a sanitarian point of view that, during production, operator's hand touches lipsticks which are brought into direct contact with user's lips at usage. Further, since the work is usually done by female operators in order to save labour cost, lipsticks are liable to be contaminated by powdery cosmetics and/or dandruff of the operators.
In order to avoid such troubles caused by manual handling in the assemblage, a rotary capsule type lipstick moulding machine has already been proposed. This moulding machine includes a great number of capsules which are arranged upright along the periphery of a round rotary table. Material paste is charged into the capsules during rotation of the table and, after solidification by cooling, lipsticks are discharged from the capsules by application of compressed air. No crests are developed on the surface of the lipsticks and moulding operation is automatized for effective reduction in manual labor. Continuous charge of the material paste appreciably streamlines the process.
Incidently, production of lipsticks faces a wide variety of quality demands. Point of sales of a lipstick is usually put on its configuration, in particular the shape of the tip. So, the production must be flexible enough to supply lipsticks of various configurations. The life cycle of a type of lipsticks is in general very short. Frequent change in type is caused by fashion factors, seasonal factors and geographical factors, and such change in type in most cases accompany corresponding change in stick configuration. Thus, production of lipsticks usually takes the form of a small scale production with high lot number. In other words, lipstick production is unsuited for any mass production system.
When appreciated from this point of view, the above-described automatic moulding machine needs to keep a wide variety of capsule groups, each group including a great number of capsules. A great deal of labour is needed for shifting from one lot to another lot while handling vast number of capsules. Separate control and separate storage of capsules also requires a great deal of attention and labour. For these reasons, the proposed automatic moulding machine is quite unsuited for the small scale production with high lot number which is unavoidably required for production of lipsticks.
SUMMARY OF THE INVENTION
It is the primary object of the present invention to provide a fully automatic system for assembling stick-type cosmetics which is well suited for small scale production with high lot number.
It is another object of the present invention to provide a fully automatic system for assembling stick-type cosmetics without any contamination and/or damage of sticks.
It is the other object of the present invention to provide a fully automatic system for assembling stick-type cosmetics with high process efficiency whilst minimizing machine idle time, semi-product stagnation and waste in operation.
The fully automatic assembling system in accordance with the present invention is based on use of a pair of NC robots which cooperate with each other in full coordination. This first robot is equipped with fingers for clamping moulds and movable in three-dimensional directions. The second robot is equipped with finger plates for clamping bottles and holding nozzles for holding bottles, both being movable in three-dimensional directions.
At operational stations taken around the first robot, are arranged a mould supply unit, a material charge unit, a cooling unit and, preferably, a defective mould unit, all within the operational ambit of the fingers of the first robot. At operational stations taken around the second robot, a bottle supply unit, a bottle draw-out unit, a stick draw-in unit and a capping unit, all within the operational ambits of the finger plates and the suction holders of the second robot. Further, a docking unit is arranged astride the operational ambits of the first and second robots.
The fingers of the first robot take out an empty mould from the mould supply unit or from the docking unit in order to supply same to the material charge unit for charge of the material paste. The fingers further take out a charged mould from the material charge unit and supply same to the cooling unit whereat the fingers take out a cooled mould in order to supply same to the docking unit. The cooled mould is first opened at the docking unit in order to expose the tails of solidified sticks out of the upper face of the mould.
The holding nozzles of the second robot take out prescribed number of bottles at once from the bottle supply unit and supply same to the bottle draw-out unit whereat the finger plates take out drawn-out unit whereat the finger plates take out drawn-out bottles in order to supply same to the docking unit. At the docking unit the bottles are combined with the sticks on the mould. Next, the stick-bottle combinations are taken out from the mould by operation of the holding nozzles for supply to the stick draw-in unit at which the finger plates take out drawn-in stick-bottle combinations for supply to the capping unit. At the capping unit, each stick-bottle combinations is combined with a cap standing by in a pallet to form a lipstick.
DESCRIPTION OF THE DRAWINGS
FIGS. 1A to 1C are perspective views for showing operational steps taken in assemblage of lipsticks,
FIG. 2 is a perspective view of one example of the mould used for shaping of sticks,
FIG. 3 is a plan view of the whole construction of one embodiment of the apparatus in accordance with the present invention,
FIG. 4 is a perspective view of one embodiment of the first robot used for the apparatus shown in FIG. 3,
FIG. 5 is a perspective view of one embodiment of the head of the first robot shown in FIG. 4,
FIG. 6 is a perspective view of the head of the second robot used for the opperatus shown in FIG. 3,
FIG. 7 is a perspective view of one embodiment of the material charge unit for the apparatus shown in FIG. 3,
FIG. 8 is a perspective view of one embodiment of the bottle draw-out unit or the stick draw-in unit used for the apparatus shown in FIG. 3, and
FIG. 9 is a perspective view of one embodiment of the docking unit used for the apparatus shown in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A to 1C depict a part of the operational steps in assemblage of lipsticks to which the present invention is advantageously applied. As well known, a lipstick is made up of a stick 1, a bottle 2 and a cap 3. The bottle 2 includes a stick holder 2a into which the tail of the stick 1 is force inserted, a main case 2b for encasing the stick holder 2a with the stick 1 and a rotary body 2c which is connected to the tail of the stick holder 2a and extends on the rear side of the main case 2b. When the rotary body 2c is rotated while holding the main case 2b, a built-in spiral mechanism drives the stick holder 2a for projection from and withdrawl into the main case 2b. Projection of the stick holder 2a is referred to as "bottle draw-out" and withdrawl of the stick holder 2a is referred to as "stick draw-in". These operations are shown in FIG. 1A. Combination of a stick 1 with a drawn-out bottle 2 is referred to as "docking", which is shown in FIG. 1B. At docking, the tail of the stick 1 is force inserted into the stick holder 2a of the bottle 2.
After completion of the docking, a stick-bottle combination is subjected to stick draw-in and further to combination with a cap 3. This operation is referred to as "capping", which is shown in FIG. 1C.
An embodiment of a mould used for shaping of lipsticks is shown in FIG. 2, in which a metallic mould 4 is comprised of an upper splittable section 4a and a lower base section 4b. These sections 4a and 4b are connected to each other by side hinges 6. As shown with arrows in the illustration, the splittable section 4a can be opened sideways. An array of stick holes 7 are formed vertically in the mould 4 whilst opening in the top face of the mould 4. Although eight stick holes 7 are shown in the illustration, the number of the stick holes 7 in a mould is unlimited to this example. Each stick hole 7 is given in the form of a blind hole whose bottom corresponds in shape to the tip 1a of a stick 1 shown in FIG. 1B. The splittable section 4a is provided on its end faces with pairs of pin holes 8 for engagement with later described pins for opening of the splittable section 4a. After solidification by cooling of the material pasted charged in the stick holes, the spittable section 4a is opened sideways so that the tails of sticks 1 should be exposed out of the top face of the base section 4b.
The whole construction of one embodiment of the apparatus in accordance with the present invention is shown in FIG. 3, in which a number of operational units are arranged arround a pair of robots within their operational ambits.
The first robot 100 shown in the upper half of the illustration is involved in handling of moulds 4 for formation of sticks. At operational stations properly taken around the first robot 100 are arranged a mould supply unit 120, a material charge unit 140, a defective mould unit 160 and a cooling unit 180. The second robot 200 shown in the lower half of the illustration is involved in handling of bottles 2 including those combined with sticks 1. At operational stations properly taken around the second robot 200 are arranged a bottle supply unit 220, a bottle draw-out unit 240, a stick draw-in unit 260 and a capping unit 280. At an operational station astride the operational ambits of the two robots 100 and 200 is arranged a docking unit 320.
(I) Construction and Individual Operations of the First Robot 100
The whole construction of one embodiment of the first robot 100 is shown in FIG. 4, in which the robot 100 includes, as major components, a pedestal 101, a main body 102 mounted to the pedestal in a horizontally rotatable arrangement, an arm 103 extending forwards from the main body 102 and longitudinally extensible in a telescopic fashion, and a head 104 attached to the tip of the arm 103. As the main body 102 rotates on the pedestal 101, the head 104 at the arm tip travels from unit to unit as shown with a chain arc line in the illustration. As the arm 103 extends or shrinks, the head 104 moves towards or away from each unit. Rotation of the main body 102 and extension of the arm 103 are carried out by proper known mechanisms under numerical control by the robot 100.
One embodiment of the head 104 of the first robot 100 is shown in FIG. 5, in which the head 104 includes a head main body 111 secured to the tip of the arm 103 and a finger holder 112 arranged below the head main body 111 in a vertically movable fashion. More specifically, a pair of guide posts 113 and a drive shaft 114 are secured to the top face of the finger holder 112 and extend upwards idly through the head main body 111. The drive shaft 114 is placed in engagement with a proper drive mechanism such as a pinion-rack mechanism built in the head main body 111 and driven thereby for longitudinal movement. Different types of driving mechanism may be used for the drive shaft 114. The finger holder 112 is provided with two pairs of fingers 115 projecting downwards and the fingers 115 in each pair are provided with resilient clamp pieces 116 attached on their mating faces. The fingers 115 in each pair are driven for movement towards and away from each other by a proper drive mechanism such as solenoids built in the finger holder 112. When the fingers 115 move towards each other, they clamp a mould such as shown in FIG. 2 via the clamp pieces 116. Whereas they release the mould 4 when they move away from each other.
As is clear from the foregoing, the fingers 115 forming the operational terminal of the first robot 100 travel from unit to unit on rotation of the main body 104 on the pedestal 101, move towards and away from each unit on extension and shrink of the arm 103, move upwards and downwards in relation to a mould 4 on placed a unit on vertical movement of the finger holder 112 with respect to the head main body 111, and clamp and release a mould on their mutual approach and separation.
(II) Construction and Individual Operations of the Second Robot 200
The whole construction of the second robot 200 is substantially same as that of the first robot 100 and its illustration is therefore omitted. On the second robot 200, a main body is mounted to a pedestal in a horizontally rotatable arrangement a telescopically extensible arm 203 projects forwards from the main body and a head 204 is coupled to the tip of the arm 203. As the main body rotates on the pedestal, the head 204 at the arm tip travels from unit to unit as shown with a chain arc line in FIG. 3 and moves towards and away from each unit as the arm 203 extends and shrinks. Rotation of the main body and extension of the arm 203 are carried out by known drive mechanisms under numerical control by the second robot 200.
One embodiment of the head 204 of the second robot 200 is shown in FIG. 6, in which the head 204 includes a main body holder 210 secured to the tip of the arm 203. A head main body 211 is mounted to the main body holder in a horizontally rotatable arrangement. A finger holder 212 is arranged below the fore section of the head main body 211 and vertically movable along guide posts 215 carried by the head main body 211. A pair of finger plates 213 are mounted to the finger holder 212 and provided, at the lower ends on the mating faces, with clamper teeth 214 adapted for clamping prescribed number of bottles 2 at once. The finger plates 213 are driven by a proper drive mechanism such as solenoids built in the finger holder 212 for movement towards and away from each other. That is the prescribed number of bottles 2 are clamped by the pair of clamper teeth 214 when the finger plates 213 move towards each other. Whereas, the bottles 2 are released from the clamp at once when the finger plates 213 move away from each other.
A nozzle holder 217 is arranged below the rear section of the head main body 211 substantially in parallel to the finger holder 212 and vertically movable along guide posts 216 carried by the head main body 211. Holding nozzles 218 are carried by the nozzle holder 217 and project downwards. The number of the holding nozzle 218 is equal to the number of bottles 2 clamped at once by the finger plate 213. The holder nozzles 218 are connected to a proper pneumatic suction source built in the nozzle holder 217. The holding nozzles 218 hold bottles 2 when the suction is turned on, and release sam when the suction is turned off. The vertical movements of the finger holder 112 and the nozzle holder 217 are operationally related to each other but may be caused by separate mechanisms.
As is clear from the foregoing, the finger plates 213 and the holding nozzles 218 forming the operational terminals of the second robot 100 travel from unit to unit on rotation of the main body on the pedestal, move towards and away from each unit on extension and shrink of the arm 203 and shift their positions in horizontal planes on rotation of the head main body 211 about the main body holder 210. This horizontal change in position may take place at a unit or during travel between units. The finger plates 213 move vertically towards and away from bottles placed on a unit on the vertical movement of the finger holder 212 with respect to the head main body 211. The finger plates 213 further clamp and release the bottles on their mutual approach and separation. The holding nozzles 218 move towards and away from bottles placed on a unit on the vertical movement of the nozzle holder 217 with respect to the head main body 211. The holding nozzles 218 further hold and release the bottles on turning on and off of the suction.
(III) Construction and Operation of the Mould Supply Unit 120
The mould supply unit 120 may be given in the form of a known belt or chain conveyer mechanism which bears thereon arrays of mould in an upright position. The circulation of the conveyor mechanism is timed to the operation of the first robot 100 so that the mould should be periodically supplied to the operational ambit of the fingers 115 of the first robot 100.
(IV) Construction and Operation of the Material Charge Unit 140
One embodiment of the material charge unit 140 is shown in FIG. 7, in which an operation table 143 is idly inserted over horizontal guide bars 142 secured to a stand 141 in operational engagement with a drive shaft 144 driven for rotation by a proper drive motor build in the stand 141. On rotation of the drive shaft 144, the operation table 143 travels along the guide bars 142 between a transfer position A and a charging position B. At the transfer position A, is located a pusher magagine 145 in front of the operation table 143. As a pusher 146 encased in the pusher magagine advances, a mould 4 on the operation table 143 is pushed rearwards as shown with an arrow in the drawing. A material charger 147 arranged at the charging position B is provided with a demoulding agent nozzle 148 and a material paste nozzle 149.
A mould clamped by the fingers 115 of the first robot 100 is first placed and released onto the fore side section of the operation table 143. Next, the pusher 146 advances to push the mould 4 rearwards. Thereupon, the drive shaft 144 starts to rotate in one direction and the operation table 143 moves towards the charging position B along the guide bars 142. On arrival at the operational ambit of the material charger 147, the demoulding agent nozzle 148 first intrudes into the first stick hole 7 of the mould 4 for coating of the demoulding agent and the material paste nozzle 149 next charges the material paste in the first stick hole 7. As the material paste have been charged in all of the stick holes 7, the drive shaft 144 rotates in the reverse direction and the operation table 143 returns to the transfer position A. The fingers 115 of the first robot 100 them clamp the charged mould 4 in order to take it out from the material charge unit 140.
The foregoing explanation is directed to handling of a single mould 4. In practice, however, a number of moulds 4 are sequentially supplied to the material charge unit 140, sequentially charged with the material paste, and sequentially taken out from the material charge unit 140. In order to meet this sequential operation, the fingers 115 of the first robot 100 first supplies an empty mould 4 onto the fore section of the operation table 143, move upwards, rearwards and downwards in order to clamp and take out a charged mould 4 placed on the rear section of the operation table 143. Thereafter, the pusher 146 advances in order to push the empty mould 4 rearwards. This process is repeated by the fingers 115 and the pusher 146 on every arrival of the empty mould.
(V) Construction and Operation of the Defective Mould Unit 160
The defective mould unit 160 is used for excluding defective moulds 4 out of the system when separation of sticks 1 from a mould 4 cannot be carried out well at the docking unit 320. Since happening of this malfunction at the docking unit 320 is not so frequent, the defective mould unit 160 may be given in the form of a simple flat table receptive of defective moulds transferred from the docking unit 320 by operation of the fingers 115 of the first robot 100.
(VI) Construction and Operation of the Cooling Unit 180
The cooling unit 180 is used for solidification by cooling of the material paste charged in a mould 4 at the material charge unit 140, and, therefore, may be given in the form of a simple cooling bath or a simple cooling chamber. In the simplest case, moulds 4 are placed in a cool water contained in a cooling bath. A cooling chamber with circulating cooling air may be used with its top opening being shut by an air curtain. For effective cooling, it is preferable that several moulds should always stay together at the cooling unit 180. In this way, the cooling unit 180 may act as a sort of temporary reservoir of moulds 4 for coordination in the general operation of the whole system In the case of the illustrated embodiment, three moulds 4 always stay at the cooling unit 180. A charged mould 4 is supplied from the side of the unit close to the robot 100 and a cooled mould 4 is taken out from the side of the unit remote from the robot 100.
(VII) Construction and Operation of the Bottle Supply Unit 220
The bottle supply unit 220 includes pallet take-in and take-out channels 221 and 222 arranged side by side, each being provided with a proper belt or chain conveyer mechanism. Each pallet P contains arrays of bottles 2 positioned upside down. A pallet P with bottles 2 is supplied along the take-in channel 221. The holding nozzles 218 (see FIG. 6) of the second robot 200 take out one aray of bottles 2 at one time. After bottles 2 have been all taken out by repeated operation of the holding nozzles 218 of the second robot 200, the empty pallet P is passed to the take-out channel 222 by operation of a proper shifter mechanism (not shown) and discharged from the system along the take-out channel 222.
(VIII) Construction and Operation of the Bottle Draw-Out Unit 240
For combination of a stick 1 with a bottle 2, the stick holder 2a of the bottle 2 has to project out of the main case 2b as shown in FIG. 1A. However, on bottles 2 supplied by bottle makers, i.e. on bottles supplied from the bottle supply unit 220, the position of the stick holder 2a differs from bottle to bottle quite at random. So, for the sake of smooth combination, the position of the stick holders 2a has to be detected and, when a stick holder 2a of a bottle 2 is withdrawn, the stick holder 2a has to be completely drawn out of the main case 2b in advance to combination with a stick 1. This operation is carried out by the bottle draw-out unit 240.
One embodiment of the bottle draw-out unit 240 is shown in FIG. 8, in which the bottle draw-out unit 240 includes, as major components, a bottle holding assembly 241 and a bottle rotating assembly 251.
The first holder 242 of the bottle holding assembly 241 carries a number of fixed holding teeth 243 arranged side by side in a horizontal direction. Facing the fixed holding teeth 243, same number of mobile holding teeth 244 are arranged side by side in a horizontal direction. Each mobile holding tooth 244 is operationally coupled to the second holder 246 by means of a drive shaft 245 in screw engagement with the bottom of the mobile holding tooth 244. Facing fixed holding tooth 243 and mobile holding tooth 244 have in their mating faces cutouts adapted for holding a bottle 2. As the drive shafts 245 are driven for rotation by a proper drive mechanism built in the second holder 246, the mobile holding teeth 244 move horizontally towards and away from the fixed holding teeth 243. Though omitted in the illustration, proper guides are arranged for smooth horizontal movement of the mobile holding teeth 244.
The first and second holders 242 and 246 are both idly inserted over guide bars 248 extending forwards from the third holder 247 on the rear side. The first and second holders 242 and 246 are driven, by a proper drive mechanism, for movement between a transfer position C taken on the fore side and a draw-out position D taken on the rear side.
The bottle rotating assembly 251 is provided with a rotor holder 252 which is operationally coupled to a proper drive mechanism (not shown) via a support shaft 253 for vertical movement at the draw-out position D. A number of rotors 254 are coupled to the rotor holder 252 via spring mechanisms 255 whilst projecting downwards. The number of the rotor 254 is equal to that of the fixed holding teeth 243 (or the mobile holding teeth 244). The rotors 254 are driven for rotation by a proper drive motor built in the rotor holder 252. The spring mechanisms 255 allow elastic pressure contact of the rotors 254 with bottles 2.
The bottle draw-out unit 240 is preferably provided with a proper detector such as a photoelectric sensor adapted for discrimination of bottle size. Operation of the bottle draw-out unit 240 should be started at different moments depending on the size of the bottle to be processed.
Before the operation is started, the bottle holding assembly 241 is located at the fore transfer position C and the mobile holding teeth 244 are located remote from the fixed holding teeth 243. Under this condition, the holding nozzles 218 of the second robot 200 supply the bottles 2 in an upside down position to the bottle draw-out unit 240 and locate the main cases 2b of the bottles 2 between the fixed and mobile holding teeth 243 and 244. Thereupon, the mobile holding teeth 243 is drived for movement towards the fixed holding teeth 243 by rotation of the drive shaft 245 in order to clamp the main cases 2b of the bottles 2 in between the fixed and mobile holding teeth 243 and 244.
While keeping this condition, the first and second holders 242 and 246 move rearwards towards the draw-out position D along the guide bars 248. Then, the rotor holder 252 moves downwards so that the rotors 254 should be brought into elastic pressure contact with the tails of the rotary bodies 2c of the bottles 2. Under this condition, the rotors 254 are driven for rotation so that the rotary bodies 2c should be rotated with respect to the main body 2b blocked against rotation due to the clamp by the fixed and mobile holding teeth 243 and 244. Thanks to this relative rotation, the stick holders 2a all project out of the main cases 2b of the bottles 2. Draw-out operation is thus completed.
Thereafter, the bottle rotating assembly 251 moves upwards, the first and second holders 242 and 246 move forwards towards the transfer position C and the finger plates 213 (see FIG. 6) of the second robot 200 clamp the tails of the bottles 2. Then, the mobile holding teeth 244 are driven for rearward movement by the reverse rotation of the drive shaft 245 in order to release the clamp on the bottles 2 which are then taken out in an upside down position from the bottle draw-out unit 240 by operation of the finger plates 213 of the second robot 200.
(IX) Construction and Operation of the Docking Unit 320
One embodiment of the docking unit 320 is illustrated in FIG. 9, in which guide bars 323 are horizontally carried by a stand 322 secured on a pedestal 321 and an operation table 324 is idly inserted over the guide bars 323. The bottom section of the operation table 324 is in screw engagement with a drive shaft 325 which is driven for rotation by a proper drive motor built in the stand 322. As the drive shaft 245 rotates, the operation table 244 travels along the guide bars 232 between a transfer position E and a docking position F. At the transfer position, are a pair of stands 326 located on both sides of the operation table 324 and each stand 326 is provided with a pair of opener gears 327 arranged side by side in meshing engagement on its face close to the operation table 324. Each opener gear 327 is provided with an opener pin 328 projecting from its end facing the operation table 324. Further, the opener gears 327 are movable towards and away from the operation table 324 and one of the opener gears 327 is positively driven for rotation by a proper drive motor built in the stand 326.
Before the docking operation is started, the operation table 324 is located at the transfer position E as shown in the drawing. A cooled mould 4 taken from the cooling unit 180 by operation of the fingers 115 (see FIG. 5) of the first robot 100 is supplied to the docking unit 320 and placed on the operation table 324. Then, the operation table 324 moves towards the docking position F while being driven by rotation of the drive shaft 325 in order to bring the mould 4 to the position of the opener gears 327. Next, the opener gears 327 advance towards the mould 4 from both sides in order to insert their opener pins 328 into the pin holes 8 (see FIG. 2) in the end faces of the mould 4. Under this condition, eather of the opener gears 327 is driven to rotate outwards so that the other opener gear 327 should rotate oppositely outwards. As the opener pins 328 separate from each other due to such reverse rotations of the opener gears 327, the splittable section 4a of the mould 4 is opened sideways so that the tails of the solidified sticks 1 should project from the top face of the base section 4b of the mould 4.
Under this condition, the drive shaft 325 further rotates in order to bring the operation table 324 to the docking position F. Thereupon, the stick holders 2a of the bottles 2 clamped upside down by the finger plates 213 of the second robot 200 are force inserted over the tails of the sticks 1 projecting from the mould 4 by downward movement of the finger plates. Docking operation is now over.
By upward movement of the finger plates 213, the sticks 1 are separated from the mould and stick-bottle combinations in an upside down position are next taken out of the docking unit 320 by further movement of the finger plates 213.
(X) Construction and Operation of the Stick Draw-In Unit 260
In assemblage of a lipstick, the stick 1 has to be withdrawn into the bottle 2 in advance to the capping operation. To this end, the rotary body 2c is rotated in a direction opposite to that in the bottle draw-out operation while blocking the main case 2b against rotation. Therefore, the construction of the stick draw-in unit 260 is substantially same as that of the bottle draw-out unit 240 shown in FIG. 8, and its illustration is omitted.
Stating the operation roughly, the main cases 2b of the stick-bottle combinations supplied by the finger plates 213 of the second robots 200 are clamped in between fixed and mobile holding teeth, rotors are brought into pressure contact with tails of the rotary bodies 2c of the bottles 2, the sticks 1 are withdrawn into the bottles by rotation of the rotors, and the drawn-in bottles 2 are taken out of the docking unit 260 by operation of the holding nozzles 218 (see FIG. 6) of the second robot 200.
(XI) Construction and Operation of the Capping Unit 280
The construction of the capping unit 280 is substantially same as that of the bottle supply unit 220. That is, the capping unit 280 includes take-in and take-out channels 281 and 282 arranged side by side. The channels are equipped with proper belt or chain conveyer mechanisms circulating in opposite directions. For supply along the take-in channel 281, caps 3 are encased within a pallets with their open ends upside. The holding nozzles 218 of the second robot 200 insert the bottles 2 into the caps 3. When the pallet Q is full of capped bottles 2, the pallet Q is passed to the take-out channel 282 for discharge from the system by operation of a proper shifter mechanism not shown.
(XII) General Operation of the First Robot 100
One example of the general operation performed by the first robot 100 will now be explained in reference to FIG. 3. Moulds are indicated with two digit numbers, the first digit indicates that the object is a mould 4 and the second digit indicates the order of sequence of the mould. That is, the first mould is indicated with a reference numeral "41" whereas the third mould is indicated with a reference numeral "43".
First, the first robot 100 rotates to register its head 104 at the mould supply unit 120 and the fingers 115 takes out the first mould 41. Next, the first robot 100 rotates counterclockwise in FIG. 3 to register the head at the material charge unit 140 and the fingers 115 supplies the first empty mould 41. Material paste is charged in the first mould 41 at the material charge unit 140.
The robot 100 rotates clockwise to register the head 104 again at the mould supply unit 120 and the fingers 115 takes out the second empty mould 42. Next, the robot 100 rotates counterclockwise to register the head 104 again at the material charge unit 10, the fingers 115 supplies the second empty mould 42 and takes out the frist charged mould 41. Material paste is charged in the second mould 42 at the material charge unit 140.
Next, the robot 100 rotates counterclockwise to register the head 104 at the cooling unit 160 and the fingers 115 supply the first charged mould 41. which is then cooled at the cooling unit 180.
The robot 100 rotates clockwise to register the head 104 at the mould supply unit 120 and the fingers 115 take out the third empty mould 43. The robot 100 next rotates counterclockwise to register the head 104 at the material charge unit 140, the fingers 115 supply the third empty mould 43 and take out the second charged mould 42. Material paste is charged in the third mould 43 and at the material charge unit 140.
The robot 100 next rotates counterclockwise to register the head 104 and the cooling unit 180 and the fingers 115 supply the second charged mould 42, which is then cooled together with the first charged mould 41.
The robot 100 rotates clockwise to register the head 104 at the mould supply unit 120 and the fingers 115 take out the fourth empty mould 44. The robot 100 then rotates counterclockwise to register the head 104 to the material charge unit 140, the fingers 115 supply the fourth empty mould 44 and take out the third charged mould 43. Material paste is charged in the fourth mould 44 at the material charge unit 140. Next, the robot 100 rotates counterclockwise to register the head 104 at the cooling unit 180 and the fingers 115 supply the third charged mould 43 which is then cooled together with the first and second charged moulds 41 and 42.
The robot 100 again rotates clockwise to register the head 104 at the mould supply unit 120 and the fingers 115 take out the fifth empty mould 45. The robot 100 then rotates counterclockwise to register the head 104 at the material charge unit 140, the fingers 115 supply the fifth emply mould 45 and take out the fourth charged mould 44. Material paste is charged in the fifth mould 45 at the material charge unit 140.
The robot 100 next rotates counterclockwise to register the head 104 at the cooling unit 180, the fingers 115 supply the fourth charged mould 44 and take out the first cooled mould 41. The second to fourth charged moulds 42-44 are cooled together at the cooling unit 180.
The robot 100 now rotates clockwise to register the head at the docking unit 320 and the fingers 115 supply the first cooled mould 41. The first cooled mould 41 is subjected to docking at the docking station 320.
The robot 100 further rotates clockwise to register the head 104 at the mould supply unit 120 and the fingers 115 take out the sixth empty mould 46. Next, the robot 100 rotates counterclockwise to register the head 104 at the material charge unit 140, the fingers 115 supply the sixth empty mould 46 and take out the fifth charged mould 45. Material paste is charged in the sixth mould 46 at the material charge unit 140.
The robot 100 next rotates counterclockwise to register the head 104 at the cooling unit 180, the fingers 115 supply the fifth charged mould 45 and take out the second cooled mould 42. The third to fifth charged moulds 43-45 are cooled at the cooling unit 180.
The robot 100 rotates clockwise to register the head 104 at the docking unit 320, the fingers 115 supply the second cooled mould 42 and take out the first evacuated mould 41. The second cooled mould 42 is subjected to docking at the docking station 320.
The robot 100 rotates further clockwise to register the head at the material charge unit 140, the fingers 115 supply the first evacuated mould 41 and take out the sixth charged mould 46. Material paste is charged in the first evacuated mould 41 at the material unit 140.
The robot 100 next rotates counterclockwise to register the head 100 at the cooling unit 180, the fingers 115 supply the sixth charged mould 46 and take out the third cooled mould 43. The fourth to sixth charged moulds 44-46 are cooled at the cooling unit 180.
The robot 100 then rotated clockwise to register the head 104 at the docking unit 320, the fingers 115 supply the third cooled mould 43 and takes out the second evacuated mould 42. The third cooled mould 43 is subjected to docking at the docking unit 320.
(XIII) General Operation of the Second Robot 200
One example of the general operation performed by the second robot 200 will now be explained in reference to FIG. 3. Battles are indicated with two digit numbers, the first digit indicates that the object is a bottle 2 and the second digit indicates the order of sequence of the bottle. That is, the first bottle is indicated with a reference numeral "21" whereas the third bottle is indicated with a reference numeral "23".
The first robot 100 subsequently repeats the travel from the material charge to the cooling unit and from the cooling to the docking units so that six moulds 41-46 should circuate between these units.
First, the second robot 200 rotates to register its head 204 at the bottle supply unit 220 and the holding nozzles 218 take out the first group of bottles 21. The robot 200 next rotates clockwise to register the head 204 at the bottle draw-out unit 240 and the holding nozzles 218 supply the first group of bottles 21 to which drawing-out is applied.
The robot 200 rotates counterclockwise to register the head 204 again at the bottle supply unit 220 and the holding nozzles 218 take out the second group of bottles 22. Next, the robot 200 rotates clockwise to register the head 204 at the bottle draw-out unit 240, the holding nozzles 218 supply the second group of bottles 22 and the finger plates 213 take out the first group of bottles 22.
The robot 200 now rotates clockwise to register the head 204 at the docking unit 320 and the finger plates 213 supply the first group of bottles 21. Here, the bottles 21 are combined with, for example, the sticks 1 on the first cooled mould 41 supplied by the first robot 100. That is, docking is carried out.
The robot 200 further rotates clockwise to register the head 204 at the stick draw-in unit 260 and the finger plates 213 supply the first group of stick-bottle combination to which drawing-in is applied.
The robot 200 meanwhile rotates counterclockwise to register the head 204 at the bottle supply unit 220 and the holding nozzles 218 take out the third group of bottles 23. Next, the robot 200 rotates clockwise to register the head 204 at the bottle draw-out unit 240, the holding nozzles 218 supply the third group of bottles 23 and the finger plates 213 take out the second group of bottles 23. Drawing-out is here applied to the third group of bottles 23.
The robot 200 further rotates clockwise to register the head 204 at the docking unit 320 and the finger plates 213 supply the second group of bottles 22 which are here combined with sticks 1 on, for example, the second cooled mould 42 supplied by the first robot 100 for docking purposes.
The robot 200 rotates further clockwise to register the head 204 at the stick draw-in unit 260, the finger plates 213 supply the second group of stick-bottle combinations and the holding nozzles 218 take out the first group of stick-bottle combinations. Drawing-in is applied to the second group of stick-bottle combinations.
The robot 200 now rotates counterclockwise to register the head at the capping unit 280 and the holding nozzles supply the first group of stick-bottle combinations to which capping is applied.
The second robot 200 subsequently repeats the travel from the bottle supply unit 220 to the capping unit 280 via the bottle draw-out 240, the docking unit 320 and the stick draw-in unit 260. The bottles 2 travel in a same way while receiving different operations at different units.
(XIV) Counteractions taken by the Robots 100 and 200 at Malfunction in Docking Operation
Malfunction is most liable to happen at the docking unit 320 whereat bottles are combined with sticks. In order to meet this trouble, it is preferably employed in the present invention to arrange a proper detector at the docking unit in order to sense the state of docking. At any malfunction, the detector generates an interruption signal which urges the robots 100 and 200 to the expedient counteractions.
On generation of an interrupt signal, robot 200 does not start the operation to move the stick-bottle combinations to the stick draw-in unit 260. The first robot 100 discontinues its normal operations and rotates to register its head 104 at the docking unit 320 whereat the fingers 115 take out a defective mould. Next, the first robot 100 rotates clockwise to register the head 104 at the defective mould unit 160 and the fingers 115 supply the defective mould. Thereafter the first robot 100 takes out a new emply mould 4 from the mould supply unit 120 and supplies same to the material charge unit 140.
(XV) Variations
In the case of the material charge unit 140 shown in FIG. 7, only one set of material paste nozzle 149 is used and material paste is sequentially charged in the stick holes 7 in a mould 4 which is move by the material charger 147 by intermittent movement of the operation table 143. Alternatively, a plurality of material paste nozzles may be arranged at the material charge unit 140 in order to charge the material paste in all of the stick holes in the mould at once.
In the case of the docking unit 320 shown in FIG. 9, two pairs of opener pins 328 are used for opening a mould 4. Other types of opener mechanism may be used to this end. For example, a combination of an electric magnet with a solenoid may be used.
MERITS OF THE INVENTION
(I) Assemblage of lipsticks is carried out in a fully automatic fashion by well coordinated operations of a pair of numerically controlled robots without any manual operation. Manual labor is greatly saved.
(II) There is no manual touch at all to the objects during the process. This is very preferable from sanitary point of view in particular when the objects are lipsticks which come into direct contact with users' lips.
(III) The fully automatic operation by means of the robots and the associated operation units enables prosecution of the assemblage in a fully cleansed room which is well suited for handling of objects such as lipsticks.
(IV) Since the objects are held upside down all through the process, there is very little accumulation of dusts and other contaminations on the objects during processing.
(V) No capsules are used for holding and transportation of the objects. In the case of a lipstick, only the bottle and the mould are subjected to mechanical handling. Cost on parts is greatly reduced.
(VI) By change in the mode of numerical control at the robots, process conditions can be set very subtlly and can be adjusted easily as required. The system as a consequence is well suited for small scale production with high lot number in which shift of lot is highly frequent.
(VI) No stagnation of semi-products all through the process. The operation of the system is highly streamlined.
(VII) No idle time in operation of the robots. Supply of a new object to an operation unit is always accompanied with concurrent delivery of an operated object from the operation unit. There is no waste in operation of the robot. As a consequence, operation efficiency of the system is very high.
(VIII) Sticks are held in a mould during holding and transportation without any direct contact with the operation terminal of the first robot. Change in type of the objects requires corresponding change in shape of the stick holes only but not the configuration of the mould. Thus, change in shape of sticks requires no corresponding change in design of the first robot.
(IX) No flaming is necessary. Although a mould has a splittable section and crests may be developed on a stick during charging, the tail of the stick bearing such crests is inserted into the stick holder of a bottle at docking. Further, the sticks are accommodated within a mould before arrival at the docking station and blocked against any contact with other things after the docking station. There are niether finger prints nor wounds on the outer surface of the sticks. As a consequence, no flaming is needed to smooth the exterior of the stick.
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Assembly of stick-type cosmetics such as lipsticks is fully automatized by highly coordinated operation of a pair of robots each accompanied with sequential operational units arranged within the ambit of its operational terminal so that sticks and bottles are transferred upside down from unit to unit for application of sequential operations and combined with each other and further with caps to form complete stick-type cosmetics. Simple adjustment in numerical control of the robots and their operational terminals will span a wide variety of quality demands in the market, and will make the system well suited for small scale production with high lot number in which shifting of lots is highly frequent. There is no manual touching of the sticks during assemblage which enables high level of sanitization of the whole system.
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BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates to insulating and storm window application for windows of homes. In particular, it relates to the interior application of such insulating means.
A need has existed for a long time for an interior type insulating system for windows which, in addition to providing the insulation characteristics, was both easy and convenient to install or remove numerous times during the year, and at the same time was pleasing and attractive to the eye of the beholder. The present and continuing energy crisis has further pointed up the need for better insulating means. This invention provides such an interior type insulating system.
In the prior art many attempts have been made at providing interior means of insulating windows in homes. All have been either cumbersome to install, difficult to maintain or ugly in appearance.
The present invention overcomes all of the above mentioned characteristics, providing an insulating means that is easy to install as a total unit, easy and convenient to install and remove the insulating cover portion over the window for open-window use, simple to maintain, and by a novel and unique enclosure method provides an attractive decorative finish that is pleasing to the eye of the beholder.
None of the prior art teach the all-inclusive characteristics of the present invention, in which all of the sources of leakage are completely sealed, the basic or initial installation is simple, and the subsequent installation and removal of the insulating "pane" portion for open-window conditions is both simple and easy. In addition, none of the prior art teachings provide for a novel and unique method of enclosing the insulating system mechanism to provide an attractive and decorative appearance to the interior of the house as viewed by the eye of the beholder, as does the present invention.
It is therefore an object of the invention to provide a complete interior insulating means for the complete window assembly of a house.
It is another object of the invention to provide an insulating means for a complete window assembly that is reasonably easy to install initially at first application.
It is a further object of the invention to provide an insulating means for a complete window assembly that is economical to construct and install.
It is yet another object of the invention to provide an insulating means for a complete window assembly that may have the insulating cover portion removed for open-window use.
It is still another object of the invention to provide a complete window assembly that is simple, easy, and economical to maintain.
It is also a further object of the invention to provide an insulating means for a complete window assembly that is attractive and decorative to the eye of the beholder on the interior of the house.
Further objects and advantages of the invention will become more apparent in light of the following description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view showing all components;
FIG. 2 shows the installation on the inside of a window in a house;
FIG. 3 is an exploded view of a cross section 3--3 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and particularly to FIGS. 1 and 2, an improved insulating or storm window, the zipper-type window for houses, is shown at 10 in FIG. 1 as an exploded view of the components. The assembled zipper-type window 10 is assembled and shown in place on the interior of a house window in FIG. 2.
Referring now to FIG. 3, the exploded view of section 3--3 of FIG. 2 provides an excellent explanation of how the present invention seals one of the major sources of leakage around a window assembly in a house. It is one of the features that makes this invention an insulating means for a complete window assembly in a house that is not found in the prior art.
In FIG. 3, the frame 11 of a complete window assembly 12 (FIG. 1) is shown fastened to the wall 48 of the house structure. It is at the interface of the frame 11 and the wall 48 where a major source of leakage occurs (the frame 11 of the complete window assembly 12 in FIG. 1, consisting of the side casings 13, the header 15, and the apron 17).
To seal this major source of leakage the present invention seals it by the design which completely surrounds said frame 11. At the interface of the zipper-type window components (hereinafter identified) and the wall 48 on all four sides of the frame 11, that is, at the outside edges of the casings 13, the header 15, and the apron 17, an insulating material 52 (FIG. 3) is sandwiched between the zipper-type window components and the wall 48. The zipper-type window components that surround the four sides of said frame 11 are shown in FIG. 1. They are: stationary side panels 14 and 18 that are installed adjacent to the two window casings 13; stationary top panel 16 tht is installed adjacent to the window header 15; and stationary bottom panel 20 that is installed adjacent to the window apron 17.
In FIG. 3 the stationary bottom panel 20 is shown in relation to said insulating material 52 which is shown between the stationary bottom panel 20 and the wall structure 48. The same relationship exists between stationary panels 14, 16, and 18, insulating material 52, and the wall structure 48.
The stationary panels 14, 16, 18, and 20 are fixed to the wall structure 48 by attaching means 46. The attaching means may be an adhesive, nails, screws, or other method to secure the components together in a tight sandwich manner to seal against all leakage through the exterior edges of the stationary panels.
The stationary panels 14, 16, 18, and 20 are fitted at their joining corners to form a tightly sealed unit. They may be fastened at these fitted corners by an adhesive, nails, screws, cleat, or other means.
It should be noted that other methods of fastening stationary panels 14, 16, 18, and 20 to each other and to said wall structure 48, enclosing said insulating material 52 are within the scope and intent of this invention. It should also be noted that the configuration of the stationary panels 14, 16, 18, and 20 to surround other configurations of window assemblies 12 is within the scope and intent of this invention.
Attached to the stationary panels 14, 16, 18, and 20 are movable panels 22, 24, 26, 28 respectively, attached by hinge means 30. These movable panels 22, 24, 26, and 28 may be shimmed (not shown) under the hinge means 30 to clear the zippered components hereinafter described or said movable panels 22, 24, 26, 28 may be undercut (not shown) to provide a clearance for zippered components, as hereinafter described.
These movable panels 22, 24, 26, and 28 provide a cover means for the zippered components and give the attractive and decorative touch to the installation to make it pleasing to the eye of the beholder. The hinge means 30 permits the movable panels 22, 24, 26, and 28 to be "opened" or moved outwardly on the hinge means so that the zippered panel (hereinafter described) may be installed when full closure is desired or removed when an open-window effect is wanted. As shown in FIG. 3, decorative scoring or fluting 50 of a variety of designs may be added to the movable panels 22, 24, 26, and 28.
The movable panels 24, 26, and 28 are shown in the closed or covering position at the right side of FIG. 2; movable panel 22 is shown in the open or uncovered position by operation of the hinge means 30 at the left side of FIG. 2. The decorative scoring or fluting 50 on the movable panels 24, 26, and 28 is also seen at the right side of FIG. 2.
It should be understood that the manner of hinge means 30 may be butt type, piano type, or any other type of hinge means and such variations are within the scope and intent of this invention. Likewise the variation of the scoring or fluting 50 for the movable panels 22, 24, 26, and 28 is a matter of decorative choice and is within the scope and intent of this invention.
The assembly of the zipper means (frame attached zipper 32, cover panel attached zipper 34, and zipper closer operator 36) are shown in the exposed portion at the left side of FIG. 2. The zipper means components are also shown in the exploded view of FIG. 1, wherein the frame attached zipper 32 is shown on the section which is attached permanently to the frame as hereinafter described, and the cover panel attached zipper 34 is shown on the cover panel that carries the insulating cover 38. The insulating cover may be a clear plastics or any other desired material of any color or degree of opacity.
It should be understood that any such variations of materials, color, clear or opaque, are within the scope and intent of this invention. Likewise, the use of a screen for ventilation instead of the solid-type covering for insulation is also within the scope and intent of this invention.
The zipper closer operator 36 is permanently attached to the cover panel zipper 34. The frame zipper 32 has an entry end for starting the zipper closer operator 36 so that the two components may be attached to each other. This manner of connection and separation is the conventional type as used on clothing jackets and other garments where the zipper components must be separated.
Referring now to FIG. 3, the exploded view shows the manner in which the zipper component 32 is attached to the stationary frame panels (14, 16, 18, and 20) and the zipper component 34 is attached to closure panel 38.
The zipper component 32 is sandwiched between a reinforcement means 40 and the stationary frame panel 20 (or 14, 16, or 18) and fastened permanently in place by attaching means 42 which may be an adhesive, sewing, or other method.
The zipper component 34 is attached to closure panel 38 by attaching it to a reinforcement means 54 that surrounds the edges of closure panel 38. The attachments of zipper component 34, reinforcement means 54, and closure panel 38 together as a unit is by an attaching means 44 which may be an adhesive, sewing, or other method.
It is to be understood that the use of any other method of attaching the zipper components 32 and 34 to the respective adjacent components is within the scope and intent of this invention.
Thus, when the closure panel 38 is installed the permanent and tightly fastened assembly of the components of the zipper-type window for homes provides a barrier against all sources of leakage and provides an effective insulating system. This insulating system also incorporates the attractive decorative aspects, the simplicity of maintenance, the easy method of the initial installation, and the ease with which the closure panel can be installed or removed. None of the prior art incorporates all these features, approaches them in the novel and unique method of this invention, or provides them economically.
Accordingly, modifications and variations to which the invention is susceptible may be practiced without departing from the scope of the appended claims.
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The invention is an improved insulating or storm window application for windows of homes. The zipper-type window of this invention provides an easy and quick method of installation or removal of the insulating portion and, in addition, provides the beholder an attractive and decorative enclosure when viewed from the interior of the house. The insulating portion may be removed during portions of the year and the decorative interior aspect is not altered. The zipper-type window of this invention is insulation for both summer and winter conditions.
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This application is a continuation-in-part of Ser. No. 899,903, filed August 25, 1986 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates generally to synthetic blood, and more particularly to an improved blood substitute offering improvements in oxygen carrying capacity and stability, as well as lessened risk of anaphylactoid reaction.
The facile transport of oxygen through Teflon (polyperfluoroethylene) membrane has been well known for many years. The realization of the compatibility of perfluorocarbons with oxygen led to a series of research efforts which subsequently arrived at the utilization of perfluorochemicals as oxygen carriers in a new generation of blood substitutes.
Initial work by Leland Clark of Cincinnati Childrens Hospital, Robert Geyer of Harvard and Henry Sloviter of the University of Pennsylvania, continued and extended by Naito and co-workers, led to a preparation (Fluosol DA 20%) produced for clinical testing by Green Cross of Osaka, Japan. Fluosol DA functioned as an oxygen carrier in animal experiments and showed considerable promise for human use.
However, Fluosol DA* had several significant drawbacks. First, the emulsion of fluorochemical droplets in an aqueous phase was inherently unstable, both thermodynamically and kinetically, necessitating storage of the emulsion in the frozen state. This instability also entailed a laborious and time consuing blending of the emulsion with other accessory solutions immediately before use. As second major problem with Fluosol DA was the necessity of maintaining the patient on 70 to 100% oxygen to ensure sufficient oxygen supply and exchange in the tissues. Finally, limited clinical experience with Fluosol DA showed an incidence of transfusion reactions and, in order to avoid this problem, led to the pretreatment of patients with steroids in the event a small test dose indicated sensitivity; this type of sensitivity appeared in 3% or less of all cases.
SUMMARY OF THE INVENTION
It is a major object of the invention to provide an improved blood substitute, employing combinations of fluoro or perfluorochemicals capable in the presence of suitable emulsifying agents of forming emulsions stable at room temperature and possessing enhanced oxygen carrying capacity. It is an additional object of the invention to overcome the toxic (anaphylactoid) reaction problem by the use of synthetic phospholipids in the substitute blood in which such fluoro/perfluorochemicals are employed.
DETAILED DESCRIPTION
The solubility of oxygen in fluorochemicals is correlated with the isothermal compressibility of the liquid fluorochemical. The oxygen molecules pack into voids or cavities in the liquid structure in the process of solution, but do not interact significantly with the fluorochemical molecules as evidenced by the quite small enthalpies of solution. In certain of the fluorochemical structures of this invention, the presence of voids or cavities has been intentionally incorporated into the molecular structure. This has been done in two ways, first, by selecting structures which because of their molecular shape pack poorly together and leave voids in the liquid, and second, by building voids or pockets into the molecular structure itself so as to accommodate an oxygen molecule into the interstices of individual fluorochemical molecules.
The fluoro/perfluorochemicals referred to above have structures indicated by the formulas given below. In many of these formulas, only the carbon skeleton of the molecule is shown and it is to be understood that most or all of the remaining valences of the carbon atoms are combined to fluorine atoms to form C-F bonds.
As an illustration, formula (2) shows the totally fluorinated form of hexamethylenetetramine, with O 2 molecules in structure voids. O 2 is not shown in the other formulas (3)-(16) but it will be understood the O 2 molecules can be transported by them, and also within voids or interstices formed by close packing of the structures (2)-(16), a simple illustration being O 2 carried in the void formed by three close-packed balls. ##STR1##
Such chemicals or mixtures of such chemicals with appropriate surfactants, when emulsified in water along with electrolytes and colloids compatible with natural blood, typically produce droplets which are suspended in solution and which are storable and stable at room temperature, the solution then being directly usable as an oxygen carrying blood substitute. O 2 molecules are easily loosely retained for transport in the "basket" areas of the molecules, for example as indicated in (7) and (8) above.
The emulsion contains a non-toxic fraction derived from Pluronic F-68 or equivalent, together with one or more synthetic phospholipids as emulsifiers or surfactants to stabilize the emulsion. The fraction from Pluronic F-68 is prepared by fractional precipitation with organic solvents or salts or by absorption or partition chromatography, starting in either case with commercially available Pluronic F-68. Pluronic F-68* is not a uniform molecular species but instead consists of a mixture of molecules of differing molecular weight. The effectiveness of these different molecular species as emusifying agents is a function of molecular weight or chain length. It is for this reason that in our process, highly refined fractions of optimal molecular weight are used in making the fluorochemical emulsion. In addition, the fractionation employed to prepare these purified materials tends to remove any residual materials toxic to humans or deleterious to red cells. The synthetic phospholipids differ from one another as to whether the overall structure corresponds to that of a lecithin, cephalin, plasmalogen or sphingomyelin and in the nature of the fatty acid side chains in the structure. The fatty acids differ in the number of carbon atoms, the number and placement of double bonds and in the presence or absence of alicyclic, aromatic or heterocylic rings. Synthetic phospholipids, unlike yolk phospholipids contain no trace of egg proteins which in many individuals are highly allergenic. The structure of a typical lecithin is as follows: ##STR2## where R 1 and R 2 are fatty acids selected from the group stearic acid, linoleic acid, eicosapentaenoic acid and dogosaheyaenoic acid.
In preparing and storing fluorochemical emulsions it is essential to prevent degradative reactions involving any of the components. If such reactions are allowed to occur, emulsion instability and/or toxicity may result.
Several types of such reactions are either known to occur, or may be logically expected to occur, if proper preventive measures are ignored. First, certain fluorochemicals, under the energetic influence of homogenization or sonication, especially in the presence of oxygen, can degrade to yield fluoride ion which is quite toxic. Second, any unsaturation in the fatty acid side chains of the phospholipid emulsifiers may result in the formation of peroxides if oxygen is present and if such reactions are not inhibited. For these reasons, in the present process, oxygen is excluded and, in addition, antioxidants such as vitamin E or other tocopherols are added to provide stabilization for oxygen-labile components.
An emulsion embodying the above described perfluoro compounds prepared for intravenous administration, and also containing a synthetic phospholipid, is as follows:
______________________________________ grams/100 ml.______________________________________(a) Perfluorohexamethylenetetramine 10-60(b) Perfluoro (3.3.3) propellane 0-50(c) Substance selected from the group about 3.0consisting of:(i) hydroxyethylstarch(ii) polyvinylpyrolidane(iii) modified gelatin -(iv) dextran(v) other polymer to supplycolloidal osmotic (oncotic)pressure(d) Pluronic F-68 fraction about 2.7(e) Glycerin USP (glycerol) about 0.8(optional) (if used)(f) NaCl USP about 0.6(g) Synthetic phospholipids 0.2-1.0(h) Sodium bicarbonate about 0.21(i) Dextrose about 0.18(j) Magnesium chloride · 6H.sub.2 O about 0.043(k) Calcium chloride.2H.sub. 2 O about 0.036(l) Potassium chloride about 0.034(m) Water for injection qs.______________________________________
The following are specific examples, with constituents the same as listed above in (a)-(m):
______________________________________ Examples (gms/100 ml.)Constitutents 1 2 3 4 5 6______________________________________(a) 20 20 25 25 30 30(b) 40 40 35 35 30 30(c) 3.0 3.0 3.0 3.0 3.0 3.0(d) 2.7 2.7 2.7 2.7 2.7 2.7(e) 0.8 0. 0.8 0. 0.8 0.(f) 0.6 0.6 0.6 0.6 0.6 0.6(g) 0.4 0.4 0.4 0.4 0.4 0.4(h) 0.21 0.21 0.21 0.21 0.21 0.21(i) 0.18 0.18 0.18 0.18 0.18 0.18(j) 0.043 0.043 0.043 0.043 0.043 0.043(k) 0.036 0.036 0.036 0.036 0.036 0.036(l) 0.034 0.034 0.034 0.034 0.034 0.034(m) qs qs qs qs qs qs______________________________________
In the above, the synthetic phospholipids are of the structure (17), above.
An increase in molecular weight of fluorochemical is commonly observed to result in an increase in emulsion stability. At the same time, if the fluorochemicals are of too high molecular weight, they are retained for excessive periods of time in the body; and, if the molecular weight is too low, the fluorochemical can form bubbles of vapor within the circulation and can produce enboli. These conflicting factors have led other workers to restrict the useful molecular weight range of fluorochemicals to 460 to 520.
To enable the utilization of the better emulsion behavior of higher molecular weights, the originated fluorochemicals herein maintain their integrity for a relatively short period only--i.e., during the time that supplemental oxygen carrying capacity is needed and subsequently slowly degrade to smaller molecules which are then more easily excreted.
Amidases and esterases are widely distributed in living cells and body fluids. For this reason some of the fluorochemical structures can have amide or ester bonds strategically located so as to provide points of scission when acted upon by amidases or esterases, respectively. In this way large fluorochemical molecules may be used as oxygen carriers with good emulsification properties and still be excreted in reasonable times.
Novel aspects of the invention are as follows:
1. The fluoro or perfluorochemical structures 1 through 17 shown above.
2. Synthetic phospholipids in which the fatty acid chains include those of stearic acid, linoleic acid, eicosapentaenoic acid and dogosaheytaenoic acid.
3. Carrying out the emulsification process under nitrogen or a noble gas to protect labile components of the system from oxidative degradation.
4. Packaging of the final product under nitrogen or a noble gas to protect the product from oxidation during storage.
5. Addition of the product, of vitamin E, mixed tocopherols or other antioxidants compatible with the product and with red cells, to further protect labile components of the mixture against oxidation.
6. Fractions of Pluronic F-68 selected for their superior ability to form and to stabilize emulsions of perfluorochemicals in aqueous solutions compatible with blood.
7. Incorporation of ester or of amide bonds into fluorochemical structures to enable the natural esterases or amidases in blood and tissues to break down the fluorochemical structure by hydrolysis, and to thus decrease the biological half-life of the fluorochemical in the body. This allows the use of fluorochemicals of higher molecular weight which emulsify better to be effectively excreted in reasonable lengths of time.
As regards the molecular form shown at 15, the presence of two ##STR3## groups will be noted. If we denote the structure to the left of those two groups by "R", and structure to the right by R 1 i.e. ##STR4## then, in the presence of water, the double chains are hydrolysed, i.e. ##STR5##
The reason for the two water degradable links is to reduce the molecular weight of the parent molecule, which is large, to two smaller molecular weight decomposition products, i.e. an acid and an alcohol. The parent large molecule is less capable of being expelled (breathed) from the body via the lungs, whereas the two lower molecular weight acid and alcohol products are more readily expelled.
A similar consideration is applicable to the molecular form indicated at (16), where the breakdown links are indicated by the group ##STR6## Again, ##STR7##
It is important to note that the molecular weight of the artificial blood most ordinarily lies in the range 450-525. Below the 450 level, O 2 is not efficiently trapped and has unwanted tendency to "Boil Off". It is also difficult to emulsify. Above the higher molecular weight level, the molecule is too large to be removed from the body, primilarly via the lungs. Also, emulsification of small molecules requires excessive surfactant, whereas large molecules emulsify more readily, using less surfactant; therefore larger molecules as shown at (15) and (16) are desirable as they will naturally hydrolyse into smaller molecules, readily eliminated from the body, thereby enhancing emulsification and stability, greater O 2 transport, and easier elimination from the body as via the lungs.
Oxygen carriage or transport occurs in two ways, i.e. in the molecular "basket" (see position of O 2 in molecular form (8); and O 2 entrapment between the molecules, of the forms listed at (2)-(16). Consider the following diagram, for example, wherein the perfluoro molecules are denoted by large circles, moving in a capillary, and the oxygen molecules are denoted by dots in the interstices between the large molecules. (Also note the oxygen molecules within the circles, i.e. the first way of O 2 transport referred to above). ##SPC1##
Advantgeous results includes greater O 2 transport, whereby in-breathing of excessive oxygen by the patient is not required--i.e. the patient can breath ordinary air, exclusively.
The below illustrated (12") modified form of structure (12) above is the same as the latter, except for two "break" locations containing the group ##STR8## as follows: ##STR9##
An alternate form using the "break point" group ##STR10## is as follows: ##STR11##
Similar break point connections are usable for higher molecular weight molecules of the type disclosed herein.
The introduction of fluorine into the various structures shown may be carried out after the molecular skeleton has has been completed or in certain cases before the entire molecule is assembled. As an example of the latter, it may prove preferable in preparing the macrocyclic esters and amides shown to carry out the fluorination before the ester or amide bonds are formed, as for example by an appropriate protective group of alcohol, carboxylic acid or amine to permit fluorination of the methylene groups followed by removal of the protective groups and formation of the ester or amide. Alternatively, the terminal carbons of the constituent chain to be subsequently coupled together can be chlorinated to prevent fluorination of the terminal carbons, the chlorines then later removed by hydrolysis to permit the desired functional group to be introduced.
Fluorination can be accomplished by means of any one of several fluorination reagents or conditions. The exact choice depends upon the degree of fluorination desired, the stability of the carbon skeleton and to a minor degree on convenience and cost.
If it is desired to fluorinate a molecule only partially, then chlorine may be substituted into locations where fluorine is not desired; thereafter, the chlorine is replaced by hydrogen by means of reduction leaving the fluorination intact.
To fluorinate the structures shown requires powerful fluorinating agents such as fluorine itself at very low temperatures either added directly or produced by the electrolysis of hydrogen fluoride. Somewhat milder reagents such as xenon hexafluoride are useful in the first stages of fluorination followed gradually by perfluorination or near perfluorination by a more potent reagent.
EXAMPLE
Following perfluorination procedures known in the literature (see references (1) to (7) following this example), a stream of liquid hydrofluoric acid, at a density of about 0.9 and at temperatures between -40° C. and 19.0° C., preferably about 0.0° C., is continuously fed into a reaction vessel. Also fed to the vessel is a stream of the "amine" (i.e. readily available hexamethylenetetramine), in finely divided, solid form. The feed rates are such that chemically equivalent amounts of the acid and amine are fed, per unit time, to the reaction vessel, and on a continuous basis. The reactants in the vessel are stirred and the amine particles are allowed to dissolve. The solution thus formed in the vessel is continuously electrolyzed at a voltage of about 6 volts, using an anode of Ni, and a cathode of carbon. The perfluorinated product resulting from the electrolysis has a density of above 1.5, and collects as a liquid at the bottom of the vessel, below the zone of stirring and electrolysis, and such product, perfluorohexamethylenetetramine, is withdrawn from the bottom of the vessel, on a continuous or semi-continuous basis. Any evolution of F 2 is withdrawn from the upper region of the vessel above the solution.
The compound, perfluoro (3.3.3) propellane has been disclosed as an oxygen carrier.
Synthetic methods for obtaining propellanes have developed rapidly over the last decade since the first definitive works in this area appeared (Ginsburg, D., Propellanes, Verlag Chemie (1975); Greenberg, A. and Liebman, J. F., Academic Press, New York (1978)).
The synthesis of the present compound proceeds in three stages:
1. Formation of the [3.3.3] diketone.
2. Removal of the two keto groups.
3. Perfluorination.
The first step is accomplished by condensation of an acetone dicarboxylic ester with 1, 2-diketocyclopentane. The reaction proceeds smoothly at pH 5 in water: ##STR12##
The second step is accomplished by the Wolff Kishner reaction in DMSO (dimethyl sulfoxide) at about 100° C., or by a vapor pulse, photochemically activated U.V. reaction. In this reaction one may use either activation with Hg vapor at 2537 A° or to activate at the wavelength of maximum absorption of the hydrazone group. The thermodynamic driving force for this reaction may be attributed largely to the large positive free energy of formation of hydrazine. ##STR13##
The perfluorination is carried out by the procedure used in the synthesis of perfluorohexamethylenetetramine.
1. Mellor, J. W. Comprehensive Treatise on Inorganic and Theoretical Chemistry, Supplement II, part 1, pp. 120, 129, 135. Longmans Green and Co., London (1956).
2. Simons, J. H. Chem. Rev. 8 213 (1931).
3. Simons, J. H. U.S. No. 2,519,983 (Aug. 22, 1950).
4. Simons, J. H. U.S. No. 2,490,098 (Dec. 6, 1949).
5. Simmons, T. C., et al., J.Am. Chem. Soc. 79 3429 (1957).
6. Gervasi, J. A., et al., J.Am. Chem. Soc. 78 1679 (1956).
7. Hazeldine, R. N. J.Chem. Soc. pg 1966 (1950); pg. 102 (1951).
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A blood substitute employs combinations of fluoro or perfluorochemicals capable in the presence of emulsifying agents of forming emulsions stable at room temperature and possessing enhanced oxygen carrying capacity; the invention enables preparation of an improved blood substitute, with improved O 2 carrying capacity and stability, as well as lessened anaphylactoid reaction.
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CROSS REFERENCE
[0001] This application is a national stage of PCT/CU2004/000002 filed Feb. 19, 2004 and is based upon Cuban Patent Applications No. 2003-0039, filed Feb. 20, 2003 and No. 2003-0084 filed Apr. 17, 2003 under the International Convention.
FIELD OF THE INVENTION
[0002] The field of invention is that of biotechnology, in particular, the obtainment of Vibrio cholerae live attenuated vaccine strains, more specifically, the introduction of defined mutations to prevent or limit the possibility of reacquisition and (or) the later dissemination of CTXΦ phage encoded genes by those live vaccine strains and a method to preserve them to be used as vaccines.
BACKGROUND OF THE INVENTION
[0000] First, definitions:
[0000] During the description of the invention will be used a terminology whose meaning is listed bellow.
[0003] By CTXΦ virus is meant the particle of protein-coated DNA produced by certain V. cholerae strains, which is capable of transducing its DNA, comprising cholera toxin genes, to other vibrios.
[0004] By cholera toxin (CT) is meant the protein responsible for the clinical symptoms of cholera when produced by the bacteria.
[0005] By CTXΦ-encoded toxin genes are meant, in addition to CT genes, zot and ace genes that encode for the “zonula occludens toxin” and for the accessory cholera enterotoxin, respectively. The activity of ZOT is responsible for the destruction of the tight junctions between basolateral membranes of the epithelial cells and ACE protein has an activity accessory to that of the cholera toxin.
[0006] The term well tolerated vaccine or well tolerated strain refers to such strain lacking the residual reactogenicity that characterize most of the of non-toxigenic strains of V. cholerae . In practical terms, it means that it is a strain safely enough to be used in communities without or with limited access to healthcare institutions without risks for the life of the vaccinees. It should be expected a rate of diarrhea in 8% or less of the vaccinees and the diarrhea is characterized in that it does not exceed 600 ml (grs), only 1% of the vaccinees or less could suffer from headache, which should be minor and of short duration (less than 6 h), and finally that it prompts vomits in less than 0.1% of the vaccinees, those vomits characterized for being a single episode of 500 ml or less.
[0007] By hemagglutinin protease (HA/P) is meant the protein secreted by V. cholerae manifesting dual function, being one of them the ability to agglutinate the erythrocytes of certain species and the other the property to degrade or to process proteins such as mucine and the cholera toxin.
[0008] By celA is meant the nucleotide sequence coding for the synthesis of the endoglucanase A. This protein naturally occurs in Clostridium thermocellum strains and has a β (1-4) glucan-glucano hidrolase activity able to degrade cellulose and its derivatives.
[0009] The term MSHA is referred to the structural fimbria of the surface of V. cholerae with capacity to agglutinate erythrocytes of different species and that is inhibited by mannose.
[0010] By reversion to virulence mediated by VGJΦ is meant the event in which a previously attenuated strain obtained by the suppression of CTXΦ genes reacquire all the genes of this phage through a mechanism completely dependent and mediated by VGJΦ and the interaction with its receptor, MSHA.
[0011] The possibility of disseminating the CTXΦ phage in a process mediated by VGJΦ is that in which the filamentous phage VGJΦ form a stable hybrid structure (HybPΦ) through genetic recombination with the DNA of CTXΦ and disseminate its genome with active genes toward other strains of V. cholerae , which could be environmental non pathogenic strains, vaccine strains or other from different species.
[0012] Second, information of the previous art:
[0013] Clinical cholera is an acute diarrheal disease that result from an oral infection with the bacterium V. cholerae . After more than 100 years of research in cholera there remains the need for an effective and safe vaccine against the illness. Since 1817 man has witnessed seven pandemics of cholera, the former six were caused by strains of the Classical biotype and the current seventh pandemic is characterized by the prevalence of strains belonging to El Tor biotype. Recently, beginning in January of 1991, this pandemic extended to South America, and caused more than 25 000 cases of cholera and over 2 000 deaths in Peru, Ecuador and Chile. By November 1992, a new serogroup of V. cholerae emerged in India and Bangladesh, the 0139, showing a great epidemic potential and generating great concern through the developing world. These recent experiences reinforce the need for effective cholera vaccines against the disease caused by V. cholerae of serogroups O1 (biotype El Tor) and O139.
[0014] Because convalescence to cholera is followed by an state of immunity lasting at least three years, much efforts in Vibrio cholerae vaccinology have been made to produce live attenuated cholera vaccines, that closely mimics the disease in its immunization properties after oral administration, but do not result reactogenic to the individuals ingesting them (diarrhea, vomiting, fever). Vaccines of this type involve deletion mutations of all toxin genes encoded by CTXΦ. For example, the suppression of the cholera toxin and other toxins genes encoded in the prophage CTXΦ is a compulsory genetic manipulation during the construction of a live vaccine candidate (see inventions of James B. Kaper, WO 91/18979 and John Mekalanos WO 9518633 of the years 1991 and 1995, respectively).
[0015] This kind of mutants have been proposed as one dose oral vaccines, and although substantially attenuated and able to generate a solid immune responses (Kaper J. B. and Levine M. Patentes U.S. Pat. Nos. 06,472,276 and 581,406). However, the main obstacle for the widespread use of those mutants has been the high level of adverse reactions they produce in vaccinees (Levine and cols., Infect. and Immun. Vol 56, No1, 1988).
[0016] Therefore, achieving enough degree of attenuation is the main problem to solve during the obtainment of live effective vaccines against cholera. There are at least three live vaccine candidates, which have shown acceptable levels of safety, i.e., enough degree of attenuation and strong immunogenic potential. They are V. cholerae CVD103HgR (Classical Biotype, serotype Inaba) (Richie E. and cols, Vaccine 18, (2000): 2399-2410.), V. cholerae Perú-15 (Biotype El Tor, serotype Inaba) (Cohen M., and cols. (2002) Infection and Immunity, Vol 70, Not. 4, pag 1965-1970) and V. cholerae 638 (Biotype El tor, serotype Ogawa) (Benítez J. A. and cols, (1999), Infection and Immunity. Feb; 67(2):539-45).
[0017] Strain CVD103HgR is the active antigenic component of a live oral vaccine against cholera licensed in several countries of the world, the strains Perú-15 and 638 are other two live vaccine candidates to be evaluated in field trials in a near future.
[0018] However, there is a second problem of importance to solve in those live attenuated vaccine candidates; one is the environmental safety, specially related with the possible reacquisition and dissemination of the cholera toxin genes by existent mechanisms of horizontal transfer of genetic information among bacteria. In accordance with this, the attenuated vaccine strains of V. cholerae , could potentially reacquire virulence genes out of the controlled conditions of the laboratory, in an infection event with CTXΦ phage (Waldor M. K. and J. J. Mekalanos, Science 272:1910-1914) coming from other vibrios and later on contribute to their dissemination. This process could become relevant during vaccination campaigns where people ingest thousands of millions of attenuated bacteria and keep shedding similar quantities in their stools during at least 5 days. Once in the environment, bacteria have the possibility of acquiring genetic material from other bacteria of the same or different species of the ecosystem. For these reasons, at present it is desirable to obtain vaccine candidates with certain characteristics that prevent or limit the acquisition and dissemination of CTXΦ, and especially of the genes coding for the cholera enterotoxin. As a consequence, this is the field of the present invention.
[0019] Bacterial viruses, known as bacteriophages, have an extraordinary potential for gene transfer between bacteria of the same or different species. That is the case of CTXΦ phage (Waldor M. K. and J. J. Mekalanos, 1996, Science 272:1910-1914,) in V. cholerae . CTXΦ the genes of carries the genes that encode cholera toxin in V. cholerae and enters to the bacteria through interaction with a type IV pili, termed TCP, from toxin co-regulated pilus. TCP is exposed on the external surface of the vibrios. In accordance with published results, under optimal laboratory conditions the CTXΦ phage reaches titers of 10 6 particles or less by ml of culture in the saturation phase; this allows classifying it as a moderately prolific bacteriophage. Equally the expression of the TCP receptor of this phage has restrictive conditions for its production. In spite of these limitations, the existence of this couple bacteriophage-receptor, limits in some way the best acceptance of live cholera vaccines, that is why depriving the bacteria from the portal of entrance to this phage is a desirable modification.
[0020] There are two theoretical ways of preventing the entrance of CTXΦ into V. cholerae , 1) suppressing the expression of TCP or 2) removing the TCP sites involved in phage receptor interaction. None of the two forms has been implemented due to the essentiality of TCP for proper colonization of the human intestine and elicitation of a protective immune response. It should be noted that sites involved in the TCP-CTXΦ interaction are also needed for the colonization process. (Taylor R. 2000. Molecular Microbiology, Vol (4), 896-910).
[0021] Several strategies that counteract the entrance of the virus have been evaluated such as preventing the integration of the phage to the bacterial chromosome and its stable inheritance, consisting in the suppression of the integration site and in the inactivation of recA gene to avoid recombination and integration to other sites of the chromosome. (Kenner and cols. 1995. J. Infect. Dis. 172:1126-1129).
[0022] Also, it has been recently described that the entry of CTXΦ into V. cholerae depends on the genes TolQRA, however this mutation produces sensitive phenotypes not undesired in vaccine candidates of cholera and it has not been implemented. (Heilpern and Waldor. 2000. J. Bact. 182:1739).
[0023] Further methods that prevent the entrance of phages carryings essential virulence determinants to cholera vaccine strains or other vaccine strains have not been described.
SUMMARY OF THE PRESENT INVENTION
[0024] The main subject of the present invention is related with the phage VGJΦ and its capacity to transfer the genes coding for the cholera toxin, using the Mannose Sensitive Hemagglutinin (MSHA) fimbria as receptor. Specifically, it consists in protecting the live attenuated vaccine strains from the infection with VGJΦ by introducing suppression mutations or modifications that prevent the correct functioning of this fimbria.
[0025] In the previous knowledge of this fimbria, the following aspects can be summarized. The gene product of mshA was originally described to be the major subunit of a fimbrial appendage in the surface in V. cholerae that had the capacity to agglutinate erythrocytes of different species, this capacity being inhibited by mannose (Jonson G. and cols (1991). Microbial Pathogenesis 11:433-441). As such, the MSHA was considered a virulence factor of the bacteria (Jonson G. and cols (1994). Molecular Microbiology 13:109-118). In accordance with the attributed importance, mutants deficient in the expression of the MSHA were obtained to study its possible role in virulence. It was demonstrated that MSHA, contrary to TCP, is not required for colonization of the human small intestine by the El Tor and O139 V. cholerae (Thelin KH and Taylor RK (1996). Infection and Immunity 64:2853-2856). The MSHA has been also described as the receptor of the bacteriophage 493 (Jouravleva E. and cols (1998). Infection and Immunity, Vol 66, Not 6, pag 2535-2539), suggesting that this phage could be involved in the emergence of the O139 vibrios (Jouravleva E. and cols, (1998). Microbiology 144:315-324). Later on it has been described that the fimbria MSHA has a role in biofilm formation on biotic and a-biotic surfaces contributing thus to bacterial survival outside of the laboratory and the host (Chiavelli D. A. and cols, (2001). Appl. Environ Microbiol. Jul; 67(7):3220-25 and Watnick P. I. and Kolter R. (1999). Mol. Microbiol. Nov, 34(3):586-95). It is evident from the previous data that several investigations related with the MSHA fimbria have been done, but none of them defines this pili as the receptor of a phage able to transduce in a very efficient way the genes of the cholera toxin and not only these genes but the complete genome of CTXΦ, what could notably contribute to their dissemination. Additionally, although an extensive search has been made no inventions related with this fimbria have been found, either as virulence factor or as a phage receptor mediating dissemination of CTXΦ.
[0026] On the other hand, it is common practices among those who develop live cholera vaccines to provide them freeze-dried. Thus, these preparations of the live bacteria are ingested after the administration of an antacid solution that regulates the stomach pH and so the bacterial suspension continues toward the intestine without being damaged in the stomach and achieves colonization in the intestine.
[0027] Elaboration of freeze-dried vaccines improves preservation of strains, facilitates preparation of doses, allows a long-term storage, limits the risks of contamination and makes the commercialization and distribution easier, without the need of a cold chain, generally not available in under developing countries.
[0028] Although Vibrio cholerae is considered a very sensitive microorganism to the freeze-drying process, some additives are known to enhance strain survival. Thus, for preservation of the vaccine strain CVD103HgR Classical Inaba, the Center for vaccine Development, University of Maryland, United States, the Swiss Institute of Sera and Vaccines, from Berne (ISSVB), developed a formulation, see (Vaccine, 8, 577-580, 1990, S.J. Cryz Jr, M. M. Levine, J. B. Kaper, E. Fürer and B) that mainly contain sugars and amino acids. The formulation is composed of sucrose, amino acids and ascorbic acid, and after the freeze-drying process, lactose and aspartame are added.
[0029] In a work about preservation by freeze-drying of the wild type strain 569B Classical Inaba, published in Cryo-Letters, 16, 91-101 (1995) for Thin H., T. Moreira, L. Luis, H. García, T. K. Martino and A. Moreno, compared the effect of different additives on the viability and final appearance upon liophilization and after the storage at different temperatures of this V. cholerae strain. It was demonstrated that viability losses were less than 1 logarithmic order after 3 days of storage to 45° C.
[0030] The invention CU 22 847 claims a liophilization method where the formulations contain a combination of purified proteins or skim milk with addition of polymers and/or glycine, besides bacteriologic peptone or casein hydrolysate and sorbitol, with good results for the viability of Vibrio cholerae strains of different serogroups, biotypes and serotypes. The freeze-dried bacteria keep their viability after being dissolved in a 1,33% sodium bicarbonate buffering solution used to regulate the pH of the stomach.
[0031] Any vaccine formulation of cholera that it is supposed to be used in under developing countries should have certain requisites such as posses a simple composition, be easy to prepare and manipulate, be easy to dissolve and have good appearance after dissolved. Besides, It would be also desirable not to require low storage temperatures and to tolerate high storage temperatures at least for short periods of time, as well as the incidental presence of oxygen and humidity in the container. Additionally, it is also necessary an adequate selection of the composition of the formulation that allows the preservation of Vibrio cholerae of different serogroups, biotypes and serotypes. Finally, it is also remarkable that a formulation free of bovine derivate ingredients allows us to be in agreement with the international regulatory authorities related to the use of bovine components due to the Bovine Spongiform Encephalopathy Syndrome.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 . Microphotography of VGJΦ phage. Magnification×32 000. VGJΦ phage was purified from the supernatants of infected Vibrio cholerae 569 B.
[0033] FIG. 2 . Diagram of the genome of hybrid phage HybPΦ-kn, which has a high potentiality for cholera toxin transmission.
[0034] FIG. 3 . Scheme of the genetic manipulation used to suppress mshA gene of V. cholerae vaccine candidates and the suicide vector used during the proceeding.
[0035] FIG. 4 . Suckling Mice survival inoculated with an attenuated strain and its derivative infected with HybPΦ-Kn that revert it to virulence.
DESCRIPTION OF THE INVENTION
[0036] The present invention propose a new generation of live attenuated vaccines to immunize against cholera by modification of their properties, specifically improving their biological safety during colonization of humans and later in the environment, outside the laboratories.
[0037] The present invention born from the necessity to protect live cholera vaccines from infection with the CTXΦ bacteriophage, which contains the cholera toxin genes, and also to impair the potential dissemination of this phage starting from live cholera vaccine candidates. Specifically it was born from the discovery and characterization of the VGJΦ phage in our laboratory.
[0038] VGJΦ is a filamentous bacteriophage isolated from V. cholerae O139 but it has infective capacity on V. cholerae O1 of all serotypes and biotypes and also over other strains of V. cholerae O139. The sequence of this phage was not described in the complete genome sequence of V. cholerae , indicating that this phage was not present in the strain N16961 (O1, El Tor Inaba). From a broad list of V. cholerae O1 strains existing in our laboratory, none of them had homologous sequences to VGJΦ, while strains MO45, SG25-1 and MDO12C, of V. cholerae O139 had.
[0039] The VGJΦ phage infects V. cholerae through the MSHA fimbria. When this phage enters to the bacterium it can replicate or integrate into a specific chromosomal region. This is a very active phage that reaches 10 11 particles ml −1 in the culture supernatants.
[0040] The most important characteristic in this phage, by virtue of which the following application of invention is issued, is their capacity to carry out a specialized transduction of the CTXΦ phage and consequently of the cholera toxin genes. This process occurs by a site-specific recombination between CTXΦ and VGJΦ genome, followed by the encapsulation and exportation of both genomes into the VGJΦ capsid. This hybrid viral particle was named HybPΦ. A culture of bacteria infected with both, CTXΦ and VGJΦ, produce 10 11 particles ml −1 of VGJΦ and 10 7 -10 8 particles ml −1 of HybPΦ, which is at least 100 times higher than the titers obtained with CTXΦ alone.
[0041] It is also important to understand, to the purpose of this application that the CTXΦ phage receptor is TCP, which require special conditions for its expression, while the VGJΦ receptor is MSHA fimbria, an antigen that is expressed abundantly in all culture conditions studied and that is also produced in the environment. Furthermore, other vibrios produce the MSHA what increase the risk of transmission, even to other bacterial species.
[0042] It is also important to know that once, a new host become infected with HybPΦ, a stable production of particles in the range of 10 7 -10 8 ml −1 takes place in the saturation phase, thus this hybrid phage has a high potential to transmit and disseminate the cholera toxin genes.
[0043] Another aspect of supreme interest to the purpose of this invention is that cholera toxin genes in HybPΦ are active enough to produce 50 ng ml −1 of toxin during in vitro culture and that the infection of an attenuated strain with HybPΦ revert it back to virulence as assessed by the infant mouse cholera model.
[0044] In accordance with these data, a primary objective of the present invention is to describe the additional mutations made to live cholera vaccines to prevent them to be infected with either VGJΦ or HybPΦ, as well as the necessity to use live cholera vaccines from which the genome of VGJΦ is absent to avoid the dissemination of CTXΦ mediated by VGJΦ, in the case of reacquisition of CTXΦ.
[0045] An example of this mutation is a stable spontaneous mutation, conducive to the lack of expression of the MSHA fimbria in the cellular surface. This way, the VGJΦ or its derivative phage, HybPΦ could not infect such vaccines.
[0046] Another example of this mutation is a suppressive mutation in the structural gene of the major protein subunit of this fimbria (MshA).
[0047] The use of live cholera vaccine candidates in which the genome of VGJΦ is absent could be achieved simply by searching for hybridization of DNA in different strains to identify which have not homologous fragments to VGJΦ described in this invention, although other well known methodologies could be applied to remove VGJΦ from an infected strain.
[0048] Examples of live cholera vaccines to perform the specific mutations mentioned above are vaccine strains which are not able to react with a VGJΦ specific prove and that have been demonstrated in the previous art, to have acceptable levels of reactogenicity in volunteers studies. The genotype of these strains includes suppressive mutations of CTXΦ phage leaving a remnant RS1 and the insertional inactivation of hap gene with the celA gene. Such strains are constructed by means of traditional methods of suppression of the CTXΦ prophage in epidemics strains of V. cholerae , followed by the inactivation of the hemagglutinin protease gene (hap) for the insert of the marker gene celA in their sequence. To see Robert's scientific article and cols., Vaccine, vol 14 No16, 1517-22, 1996), the scientific article of Benítez J. A. and cols, (1999), Infection and Immunity. Feb; 67(2): 539-45, and the application of invention WO9935271A3, of Campos and cols, 1997. Other strains with these characteristic and that additionally have auxotrophy mutations are also useful to obtain the strains with the characteristics of interest of the present invention.
[0049] In accordance with the description in the above paragraph, a primary objective of this invention is to protect the use of suppressive or spontaneous mutations conductive to the absence of the MSHA fimbria in the surface of vibrios and in this way impede that live cholera vaccine reacquire and disseminate the cholera toxin genes by means of the infection with the hybrid phage, HybPΦ.
[0050] Among the preferred inclusions of this invention are any live cholera vaccine strain of the existing biotypes and serotypes or any non toxigenic strain of another emergent serotypes with genetic manipulations that suppress the genome of the CTXΦ phage, inactivate the hap gene, combined with any other mutation, for example the introduction of some auxotrophies (to lysine or metionine) and that also have the characteristics proposed in the present invention.
[0051] Among the preferred inclusions are also the use of the well tolerated live cholera vaccines, improved by the impossibility of acquiring the CTXΦ in an event mediated for VGJΦ and for the absence of VGJΦ that diminish the risk of dispersion of CTXΦ, as a delivery system to present heterologous antigens to the mucosal immune system.
[0052] To obtain these mutants in the expression of the MSHA fimbria we have used several molecular biology techniques which are not object of protection of the present document.
[0053] The present invention also discloses the methods to preserve and lyophilizate these strains with the purpose of being able to prepare live vaccines that present a rapid and adequate reconstitution post lyophilization without affecting their viability when being reconstituted in a solution of sodium bicarbonate 1,33%.
[0054] It is also the object of the invention that by means of the adequate selection of components, the lyophilized formulations guarantee that live cholera vaccines does not decrease their viability less than 1 logarithmic order as consequence of the storage, independently of the serogroup, serotype or biotype or the mutations they have, even if they were lyophilized for separate or mixed as part of a same preparation.
[0055] Among the formulation components to be present are lactose (L), peptone (P), yeast extract (E) and sorbitol (S). The total concentration should not exceed the 10%.
EXAMPLE 1
Discovery and Characteristics of the VGJφ Phage
[0056] VGJφ was discovered as an extrachromosomal transmissible element in total DNA preparations from Vibrio cholerae SG25-1, an O139 strain isolated in Calcuta India, 1993 and kindly donated by professor Richard A. Finkelstein. Simple experiments showed the transmissibility of this element. Free-cell culture supernatants of the donor strain, carrying the element, was grown in standard condition like LB media (NaCl 10 g/l, triptone 10 g/l and yeast extract 5 g/l) and was able to transfer to a receptor strain that does not contain any extrachromosomal element, one genetic element of the same size and restriction map that the one was present in the donor strain. The property of transmission without the direct contact between donor-receptor is typical in phages.
[0000] Infection Assays:
[0057] Donor strains were grown until optical density to 600 nm equal 0.2. One aliquot from the culture was filtered through a 0.22 μm- pore-size filter to remove the bacteria. The sterility of the filtrate was confirmed by growing one aliquot in LB plates and incubating overnight at 37° C. After checking the lack of colony forming units, 100 μl of free-cell supernatants or serial dilutions were used to infect 20 μl of a fresh culture of the receptor strain. The mixture was incubated for 20 min at room temperature and spread in solid or liquid LB media at 37° C. overnight. The infection was confirmed by the presence of replicative form (FR) and single strand DNA (ssDNA) of VGJφ in the infected vibrios.
[0000] Purification of VGJφ Phage:
[0058] Purification of phage particles was done from 100 ml of the culture of 569B Vibrio cholerae strain (classic, Inaba) infected with VGJφ. This strain was used because it contains a CTXφ f defective prophage. The cells were centrifuged at 8000×g for 10 min. The supernatant was filtered through a 0.22 μm membrane. Phage particles in the filtrate were precipitated by addition of NaCl and polyethylene glycol 6000 to a final concentration of 3 and 5% respectively. The mixture was incubated in ice for 30 min and centrifuged at 12000×g for 20 min. The supernatant was discarded, and the phage-containing pellet was suspended in 1 ml of phosphate buffered saline.
[0000] Characterization of VGJφ:
[0059] VGJφ particles precipitated retained the capacity to infect 569B strain and were stable in PBS solution during at least 6 month at 4° C.
[0060] After phage particles purification, the genomic DNA was extract using phenol-chloroform solution. The analysis of this DNA showed resistance to digestion with ribonuclease H indicating that the genome is DNA and not RNA (data not shown) and it was also resistant to the treatment with different restriction enzyme but sensitive to treatment with Mung-Bean and Sl nuclease (data not shown), indicating that the phage genome consists of ssDNA. An electrophoresis analysis in the presence of acrydine orange demonstrated similar results to the previous ones. The acrydine orange intercalated in the double stranded DNA (dsDNA) fluoresce green, while fluoresce orange when intercalates in the ssDNA. As expected, the genomic DNA fluoresced orange indicating its single stranded nature (data not shown) and the plasmid DNA observed in the infected cells fluoresced green indicating that it consists of dsDNA.
[0000] Identity Between the Genome of VGJφ and the Intracellular Replicative Form.
[0061] Southern blotting analysis carried out using the genome of VGJφ as a probe showed a genetic identity between the extrachromosomal elements of the donor strain SG25-1 and the infected strain 569B. This result confirms that the ssDNA of the viral genome is produced by the cytoplasmic RF and at the same time suggests that VGJφ is a filamentous phage, which uses the rolling circle mechanism of replication to produce the genomic ssDNA that is assembled and exported in phage particles.
[0062] The RF, isolated from the infected strain 569B, was mapped by restriction analysis. The map obtained showed that the phage genome size (about 7500 b) and the electrophoretic restriction pattern were different to those of the previously reported V. cholerae -specific filamentous phages. These results indicated that the phage isolated from SG25-1 was not described previously and it was designated VGJφ.
[0000] Titration of VGJφ.
[0063] For tittering the phage suspensions the procedure was the same as the infection assay, but the indicator strain cells were plated onto an overlay of soft agar (0,4%) over solid LB plates. The plates were incubated overnight at 37° C. and the observed opaque plaques (infection focuses) were counted.
[0064] This assay revealed that a culture of 569B infected with VGJφ is able to produce until 3×10 11 phage particles per ml of culture, what is unusually high compared with other described filamentous phages of V. cholerae like CTXφ, which produces a maximum of 10 6 particles per ml.
[0000] Electron Microscopy.
[0065] Different quantities of VGJφ particles were negatively stained with a solution of 4% uranile acetate (m/v) and observed over a freshly prepared Formvar grids in a transmission electron microscope JEM 200EX (JEOL, Japan). The observation confirmed that the phage particles had a filamentous shape ( FIG. 1 ).
[0000] Construction and Titration of VGJ-Knφ.
[0066] The RF of VGJφ was linearized by its unique XbaI site. One DNA fragment containing the R6K replication origin and a kanamycin resistance cassette from pUC4K plasmid was inserted in the XbaI site of VGJφ. This recombinant RF was introduced in V. cholerae 569B and the phage particles were designated as VGJ-Knφ.
[0067] The donor strain, 569B infected with VGJ-Knφ, was cultured until an OD 600 =2.0. An aliquot of the culture was filtered through a 0.2 um-pore-size filter to eliminate the bacterial cells. The sterility of the cell-free suspension was checked by plating an aliquot of 50 ul in a solid LB plate and incubating overnight at 37° C. Aliquots of 100 ul of the cell-free phage suspension or dilutions of it were used to infect 20 ul of a fresh culture of the receptor strain (about 10 8 cells). The mixture was incubated at RT for 20 min to allow infection. Subsequently, the mixtures were plated onto solid LB supplemented with kanamycin (50 ug/ml) and the plates were incubated overnight at 37° C. The colonies that grow in the presence of antibiotic acquired their Kn-resistance due to the infection with the marked phage VGJ-Knφ. Several of these colonies were checked for the presence of the RF of VGJ-knφ by purification of plasmid DNA and restriction analysis of it.
[0068] Titration assay done by this method agreed with those obtained by that of opaque plaques with VGJφ, showing that a culture of 569B infected by VGJ-knφ produces about 2×10 11 particles of phage VGJ-knφ per milliter of culture.
[0000] Nucleotide Sequence:
[0069] The nucleotide sequence of VGJφ consisted of 7542 nucleotides and had a G+C content of 43.39%. The codified ORFs were identified and compared to protein data bases.
[0070] The genomic organization of VGJΦ was similar to that of previously characterized filamentous phage, such as phages of Ff group (M13, fd and f1) of E. coli and other filamentous phages of V. cholerae (CTXΦ, fs1, fs2 and VSK) and V. parahemolyticus (Vf12, Vf33 and VfO3k6). VGJΦ does not have a homologous gene to the gene IV of phages of Ff group which suggests that VGJΦ could use a porine of the host for assembling and exporting its phage particles, similar to CTXΦ phage.
[0071] The nucleotide sequence of VGJΦ revealed that VGJΦ is a close relative of fs1 and VSK phages, sharing several ORF highly homologous and exhibiting 82.8 and 77.8% of DNA homology to VSK and fs1. However, there are genome areas highly divergent and ORFs not share between them. Besides, the genome size is different and it has not been described before that fs1 or VSK being capable of transducing the genes of cholera toxin.
[0072] The nucleotide sequence of VGJΦ also revealed the presence of two sites homologous to att sequences known to function in integrative filamentous phage. These sites of VGJΦ are partially overlapped and in opposite directions. This arrangement was also found in phages Cf1c, Cf16-v1 and ΦLF of X. campestris as well as Vf33 and VfO3k6 of V. parahemolyticus and VSK of V. cholerae . All these phages except Vf33 and VSK integrate in the chromosome of their hosts by the att site present in the negative strand of the replicative form of these phages.
EXAMPLE 2
Identification of VGJΦ Receptor
[0073] Filamentous phages generally use type IV pili as receptor to infect their hosts. Previously reported V. cholerae -specific filamentous phages use TCP or MSHA pili as receptor. Therefore, two mutants of the El Tor strain C6706 for these pili, KHT52 (ΔtcpA10) and KHT46 (ΔmshA), were used to identify if any of them was the receptor of VGJΦ. While parenteral strain C6706 and its TCP-mutant KHT52 were sensitive to the infection with VGJΦ, the MSHA-mutant KHT46 was fully resistant to the phage, indicating that MSHA was the receptor of VGJΦ. Complementation of strain KHT46 with wild type mshA structural gene (from parental C6706) carried on plasmid pJM132 restored phage sensitivity, confirming that MSHA is the receptor for VGJΦ. The resistance or sensivity to VGJΦ was evaluated by the absence or presence of replicative form in cultures of receptor strain analyzed after the infection assay.
[0074] To give a numerical titer of the particles which are transduced in each case, it was used an infection assay with VGJΦ-kn as was described previously, resulting the following:
[0075] The parental strain C6706 and its derivative TCP mutant KHT52 were sensitive to the infection with VGJΦ-Kn and, as indicator strains showed titres of 10 11 plaque forming units (PFU), while KHT46, a MSHA mutant, was fully resistant to the phage, less than 5 PFU/mL, after being infected with the same preparation of VGJΦ-Kn. Complementation of strain KHT46 with wild type msha structural gene, restored phage sensitivity. These results confirm that a mutation that prevents the expression of MSHA pilus confers resistance to the VJGΦ infection.
[0076] Further assays to compare the capacity of HybPΦ and CTXΦ to infect Clasical and El Tor strains were done, using their kanamycin resistant variants. See the results in Table 1.
[0077] As it has been previously described, CTXΦ-Kn phage was obtained through the insertion of a kanamycin resistance cassette from the plasmid pUC4K (Amersham Biosciences), in the unique restriction site, NotI, of the replicative form of CTXΦ.
[0078] The HypPΦ phage was obtained during an infection assay where cell free culture supernatant of 569b strain co-infected with CTXΦ-Kn and VGJΦ-Kn was used to infect the receptor strain KHT52. The cells of this strain carrying kanamycin resistance, originally carried by CTXΦ-Kn and provided to HybPΦ, were purified and, they continued producing HybPΦ viral particles to the supernatant.
[0079] To check the efficiency of infection of the hybrid phage in Classical and El Tor vibrios, suspensions of CTXΦ-Kn and VGJΦ-Kn of the same title (1-5×10 11 particles/mL) were used to infect the receptor strains 569B (Classical) and C7258 (El Tor). In both cases, the receptor strains were grown in optimal condition for TCP expression, the CTXΦ receptor. The assay was done as follows, 200 μL of pure phage preparation were mix with 20 μL (about 10 8 cells) of a fresh culture of a receptor strain during 20 min at room temperature, plated on solid LB supplemented with kanamycin and incubated over nigh at room temperature.
[0080] The numbers of colonies carry the Kn-resistance gene in their genome is the result of phage infections and show the capacity of each phage to infect different strains in routine laboratory condition. Those results are exposed in Table 1.
TABLE 1 Titration of CTXφ-Kn and hybrid (HybPΦ-Kn) phages in 569B and C7258. Kn r colony number of receptor strain Phage 569B C7258 CTXφ-Kn 5.8 × 10 5 0 HybPΦ-kn 1.5 × 10 5 7.5 × 10 4
[0081] As it is shown in Table 1 the hybrid phage transduces CT genes more efficiently than CTXΦ, the ordinary vehicle of these genes. These results point out the importance of the CTXΦ transmission mediated by VGJΦ among Vibrio cholerae strains and stressed its relevance considering the ubiquity of MSHA, the functional receptor in these bacterial strains.
EXAMPLE 3
Mobilization of CTXΦ, its Mechanism and Reversion to Virulence
[0082] Infection of V. cholerae O1 or O139 strains that carry an active CTXΦ phage with VGJΦ gives rise to the production of infective particles that bear the CTXΦ phage genome inserted in the genome of VGJΦ. These particles of hybrid phages have been designated HybPΦ. The HybPΦ titers were evaluated by means of the use of a hybrid phage, which carries a kanamycin marker (HybPΦ-Kn), employing different strains as indicators. The resultant titers are shown in Table 1.
[0083] HybPΦ-Kn was purified starting from preparations derived of 569B (HybPΦ-Kn) strain and the single strand was sequenced to determine the junctions between CTXΦ and VGJΦ. The cointegrate structure is graphically shown in the FIG. 2 and the nucleotide sequences of the junctions among both sequences, what explains the mechanism by which VGJΦ transduces CTXΦ toward other V. cholerae strains. HybPΦ-Kn enters to V. cholerae using the same receptor that VGJΦ, that is to say MSHA.
[0084] V. cholerae 1333 strain is an attenuated clone described in the previous art, similar to the strains that were useful for obtaining the derivative of the present invention. This strain is a derivative of the pathogenic C6706 strain. As it shows in the FIG. 4 , the inoculation of 10 5 colony-forming units of 1333 strain in suckling mouse does not have lethal effect, even when it is colonizing for the subsequent 15 days. Several experiments to determine virulence, demonstrated the effect of the HybPΦ-Kn infection on the reversion to virulence. While a dose of 10 5 CFU of 1333 strain does not have a lethal effect, C6706 and 1333 (HybPΦ-Kn) strains have very similar lethality profiles, and don't allow survival of inoculated mouse beyond the fifth day ( FIG. 4 ).
EXAMPLE 4
Constitutive Expression of the VGJΦ Receptor, the MSHA Fimbria, in Different Culture Conditions
[0085] To study the expression of MshA, the major subunit of MSHA fimbria, V. cholerae C7258, C6706, and CA401 strains, were grown in different media. The media used were: LB pH 6.5 (NaCl, 10 g/l; bacteriological triptone, 10 g/l; yeast extract, 5 g/l), AKI (bacteriological peptone, 15 g/l; yeast extract, 4 g/l; NaCl, 0.5 g/l; NaHCO3, 3 g/l), TSB (pancreatic digestion of casein, 17 g/l; papaine digestion of soy seed, 3.0 g/l; NaCl, 5 g/l; dibasic phosphate of potassium, 2.5 g/l; glucose, 2.5 g/l), Dulbecco's (glucose, 4.5 g/l; HEPES, 25 mm; pyridoxine, HCl, HaHCO3), Protein Free Hybridoma Médium (synthetic formulation free of serum and proteins, suplemented with NaHCO3, 2.2 g/l; glutamine, 5 mg/l; red phenol, 20 g/l) and Syncase (NaH2PO4, 5 g/l; KH2PO4, 5 g/l; casaminoacids, 10 g/l; sucrose, 5 g/l and NH4Cl, 1.18 g/l). In all cases was inoculated one colony in 50 ml of culture broth and was grown in a rotary shaker during 16 hours at 37° C., with the exception of the AKI condition in which the strains were grown first at 30° C. in static form during 4 hours and later on rotator shaker at 37° C. during 16 hours. In each case, the bacterial biomass were harvested by centrifugation and used to prepare cellular lisates. Equivalent quantities of cellular lisates were analyzed by Western Blot with the monoclonal antibody 2F12F1 for immunodetection of mshA. The MSHA mutant strain KHT46 was used as negative control of the experiment. All the studied strains, except the KHT46 negative control strain, showed capacity to produce MshA in all culture conditions tested. Equally, said strains cultured in the previous conditions have the capacity to hemagglutinate chicken erythrocytes (mannose sensitive), in the same titer or higher to 1:16 and are efficiently infected by VGJΦ-Kn, exhibiting titers higher than 10 10 particles per milliliter of culture.
EXAMPLE 5
Obtaining of Spontaneous Mutants Deficient in MSHA Expression and Evaluation of Resistance to Infection
[0086] Strain KHT46, a MSHA suppression mutant, derived from V. cholerae C6706 (O1, The Tor, Inaba), shows a refractory state to the infection with VGJΦ, VGJΦ-Kn and the hybrid HybPΦ phages. However, this is a pathogenic strain that is not property of the authors of the present application, neither of the juridical person who presented it, The National Center for Scientific Research, in Havana City, Cuba.
[0087] To obtain the spontaneous mutants deficient in the expression of superficial MSHA of the present application, was used a suppression mutant in the cholera toxin genes that during the process of obtainment resulted affected in their capacity to assemble MSHA in the cellular surface. Said mutants although are capable of producing the structural subunit of MSHA, do not assemble it in their surface and therefore do not have detectable titers of mannose sensitive hemagglutination, neither adsorb the activity of a specific monoclonal antibody against the MSHA in a competition ELISA. Since this phenotype is notably stable, these mutants were subsequently genetically manipulated to introduce an insertional mutation in the hemagglutinin protease gene, following the procedure described in patent WO 99/35271 “V. cholerae vaccine candidates and the methods of their constructing” of Campos et al, and in the Robert's article, Vaccine, vol 14 No 16, 1517-22, 1996. The resultant mutants were named JCG01 and JCG02, both of O1 serogrup, El Tor biotype, Ogawa serotype.
[0088] JCG01 and JCG02 showed a refractory state to the infection with the VGJΦ-Kn phage, a variant of the VGJΦ phage that carries a resistance marker to kanamycin. A VGJΦ-Kn suspension that had a proven titer of ˜10 11 units per ml, does not show capacity to infect said strains (non detectable titers, lower to 5 units for ml). This refractory state to the infection with VGJΦ-Kn correspond with a very low titer of hemagglutination in the strains JCG01 and JCG02 (1:2) regarding their parental (1:32) besides a total impairment in the MSHA dependent hemaglutination. Equally, whole cells of these mutants had null capacity to inhibit the interaction of the anti-MSHA monoclonal antibody (2F12F1) to MshA fixed on the solid phase in a competition ELISA. However, both strains produced the major structural subunit MshA, according to immunoblot experiments, indicating that the protein is not correctly assembling in the cellular surface although it is being produced. These mutants allowed proving the concept of this invention and passing to obtain suppression mutants.
[0000] Obtaining Suppression Mutants in the mshA Gene Starting from Other Cholera Vaccine Candidates.
[0089] To obtain suppression mutants in the mshA structural gene, two segments of the genome of V. cholerae N16961, of ˜1200 base pairs for each flank of the mshA structural gene were amplified by means of the polimerase chain reaction, using the following oligonucleotides: CNC-8125, ATG ATC GTG AAG TCG ACT ATG (21 mer); CNC-8126 CAG CAA CCG AGA ATT HERE ATC ACC ACG (27 mer); CNC-8127, ATT CTC GGT TGC TGG AAC TGC TTG TG (26 mer); and CNC-8128, GCT CTA GAG TAT TCA CGG TAT TCG (24 mer) . The amplified fragments were cloned independently and assembled in vitro to generate the pΔmshA clone. This clone contains these fragments in the same order and orientation that they are found in the bacterial chromosome; only the coding region of the mshA gene has been suppressed from the inner of the sequence. The fragment carrying the suppression was subcloned from the previous plasmid as a Sal I/Xba I fragment in the suicide vector pCVD442 to obtain the plasmid pSΔmshA.
[0090] The plasmid pSΔmshA was used to suppress the chromosomal mshA gene in the V. cholerae vaccine strains by means of a traditional methodology of allelic replacement. For it, pSΔmshA was introduced in the E. coli strain SM10□pir and mobilized toward V. cholerae by means of a procedure of bacterial conjugation. The resultant clones were selected for their resistance to the ampicillin antibiotic in plates of LB medium supplemented with ampicillin (100 □g/ml) . Most of these clones arise due to integration of the plasmid in the chromosome of the receptor vibrios by means of an event of homologue recombination between one of the flanking fragments to the chromosome mshA gene and that of the plasmid pSΔmshA, originating a cointegrate between both. This event was verified by means of a Southern blot experiment, in which the total DNA of 10 clones was digested with the restriction enzyme Sma I and hybridized with a probe obtained from the plasmid pSΔmshA (Sal I/Xba I insert). The clones of our interest are those that produce a band of 21 000 base pairs. A similar control of the parental strain in this experiment produced a band of 13 000 base pairs. The adequate clones were conserved immediately in LB glycerol at −70° C. Then 3 of them were cultured in the absence of the antibiotic selective pressure to allow that an event of homologue recombination eliminated the genetic duplication existing. This can happen by means of suppression of the original genetic structure (intact mshA gene) and replacement by a mutated copy present in the plasmid (supressed mshA gene) as is shown in FIG. 3 . The clones in which the mutated gene replaced the intact gene were analyzed by Southern blot and identified by the presence of a band of 12 000 base pairs. Finally, the clones where the mshA gene was suppressed were selected and conserved appropriately as vaccine candidates (freezing at −80° C. in LB supplemented with 20% glycerol). This procedure was performed with each clone where the mshA suppression mutant was constructed.
[0000] Serological Characterization
[0091] After the introduction of each mutation in the vaccine strains described in this document, each derivative was checked for the correct expression of the lipopolysaccharide corresponding to the original serotype. For that, cells were collected from a fresh plate, resuspended in saline (NaCl, 0.9%) and immediately examined with an appropriate agglutination serum, specific for Ogawa, Inaba or O139 vibrios.
[0092] The major immune response generated by an anti-cholera vaccine, is against the LPS, therefore the expression of the antigen corresponding to each one of the strains presented in this invention was confirmed by agglutination with specific antiserum.
[0000] Colonization Assay in Suckling Mice
[0093] The colonization assay in suckling mice (Herrington et al., J. Exper. Med. 168: 1487-1492, 1988) was used to determine the colonizing ability of each strain. An inoculum of 10 5 -10 6 vibrios in a volume of 50 □l was administered by orogastric route to groups of at least 5 suckling mice. After 18-24 hours at 30° C. the mice were sacrificed, the intestine was extracted and homogenized, and dilutions were plated in appropriate media for the growth of mutants.
TABLE 2 Colonizing capacity of the vaccine strains of the present invention. Strain Inoculum Colonizing Genotype BLR01 1.0 × 10 5 2.8 × 10 4 ΔCTXΦ, hap::celA, ΔmshA BLR02 2.0 × 10 6 4.2 × 10 4 ΔVGJΦXΦ, hap::celA, lysA, BLR03 1.2 × 10 6 8.0 × 10 3 ΔCTXΦ, hap::celA, metF, EMG01 3.0 × 10 5 8.0 × 10 6 ΔCTXΦ, hap::celA, ΔmshA EMG02 2.5 × 10 5 3.0 × 10 6 ΔVGJΦXΦ, hap::celA, lysA, EMG03 4.0 × 10 5 5.0 × 10 5 ΔCTXΦ, hap::celA, metF, JCG01 2.0 × 10 5 6.0 × 10 6 ΔCTXΦ, hap::celA, MSHA − JCG02 1.0 × 10 5 6.0 × 10 7 ΔCTXΦ, hap::celA, MSHA − JCG03 1.0 × 10 5 1.0 × 10 6 ΔCTXΦ, hap::celA, ΔmshA EVD01 3.0 × 10 5 3.0 × 10 5 ΔVGJΦXΦ, hap::celA, thyA, KMD01 1.0 × 10 6 7.0 × 10 5 ΔCTXΦ, hap::celA, metF, KMD02 2.0 × 10 6 5.0 × 10 6 ΔCTXΦ, hap::celA, lysA, ESP06 1.7 × 10 6 6.0 × 10 5 ΔCTXΦ, hap::celA, ΔVC0934, JCG04 1.0 × 10 6 2.0 × 10 7 ΔCTXΦ, hap::celA, ΔmshA ESP01 1.0 × 10 5 5.0 × 10 6 ΔVGJΦXΦ, hap::celA, metF, ESP02 6.0 × 10 5 4.0 × 10 5 ΔCTXΦ, hap::celA, lysA, ESP04 8.0 × 10 4 1.0 × 10 6 ΔCTXΦ, hap::celA, ΔVC0934, RAF01 3.1 × 10 5 5.0 × 10 7 ΔCTXΦ, hap::celA, ΔmshA EVD02 2.8 × 10 5 3.1 × 10 6 ΔVGJΦXΦ, hap::celA, thyA, ESP03 1.5 × 10 5 2.0 × 10 6 ΔCTXΦ, hap::celA, metF, KMD03 2.3 × 10 5 3.4 × 10 6 ΔCTXΦ, hap::celA, lysA, ESP05 2.1 × 10 6 2.3 × 10 6 ΔCTXΦ, hap::celA, ΔVC0934, TLP01 2.3 × 10 6 3.2 × 10 5 ΔCTXΦ, hap::celA, ΔmshA TLP02 3.4 × 10 5 9.4 × 10 4 ΔVGJΦXΦ, hap::celA, lysA, TLP03 2.7 × 10 5 8.8 × 10 4 ΔCTXΦ, hap::celA, metF,
[0094] All the strains showed adequate colonizing capacity to be used as live vaccine candidates. The colonization is needed to generate a strong immunological response because the local multiplication of the bacteria increases the duration of interaction with the mucosal immune system. In this case, although a perfect model for cholera does not exist, the suckling mice gives an adequate approach to what can be the subsequent colonization of each strain in humans.
[0000] Motility Assay
[0095] The cells of a well isolated colony are loaded in the tip of a platinum loop from a master plate toward a plate for the motility detection (LB, agar 0.4%), introducing the tip of the loop 2-3 mm in the agar. The diameter of dispersion of each colony in the soft agar to 30° C. is measured at 24 hours of incubation. A bacterial strain that reaches a diameter of 3 mm or less from the point of inoculation is considered as non-motile. A bacterial strain that grows in a diameter beyond 3 mm is considered as motile. All the strains included in this invention resulted to be motile.
EXAMPLE 6
Methods to Select and Construct the Vaccine Candidates Useful as Starting Strains to be Modified by the Procedure Disclosed in the Present Invention
[0096] Five pathogenic strains in our collection were selected as starting microorganism due to their lack of hybridization with VGJΦ sequences. These strains are V. cholerae C7258 (O1, El Tor, Ogawa, Perú, 1991), C6706 (O1, El Tor, Inaba, Perú, 1991), CRC266 (O139, La India, 1999), CA385 (Clásico, Ogawa) y CA401 (Clásico, Inaba).
[0097] The procedures disclosed in this example are not the subject of the present invention. They rather constitute a detailed description of the methods used to obtain attenuated strains that are the substrate to construct the mutants claimed in the present invention. These mutants being characterized in that they are refractory to infection by VGJΦ and the hybrid VGJΦ::CTXΦ are obtained by the methods described in the examples 4 and 5.
[0098] Below we describe the suicide plasmids used to introduce different sets of mutations into V. cholerae by allelic replacement before they are suitable to be modified by the methods of the present invention. The reader should note that the strains claimed in the present invention have in addition to the mutation that impairs the correct expression of MSHA fimbriae (a) a deletion mutation of the cholera enterotoxin genes or the entire CTXΦ prophage and (b) the hemaglutinin protease gene interrupted with the Clostridium thermocellum endoglucanase A gene. They can also have additionally and optionally mutations in the genes (c) lysA, (d) metF, (e) VC0934 (coding for a glycosil transferase) and (f) thyA.
(a) To construct atoxigenic strains by inactivation of the cholera enterotoxin genes or deletion of the CTXΦ prophage, the suicide plasmid used was pJAF (Benitez y cols, 1996, Archives of Medical Research, Vol 27, No 3, pp. 275-283). This plasmid was obtained from plasmid pBB6 (Baudry y cols, 1991, Infection and Immunity 60:428), which contains a 5,1 kb insert from V. cholerae 569B that encodes ace, zot, ctxA y ctxB. Due to the absence of RS1 sequences 3′ to the ctxAB operon in Classical vibrios, the EcoR I site downstream to the ctxAB copy in this plasmid lies in the flanking DNA of undefined function. The plasmid pBB6 was modified by deletion of the ScaI internal fragment to create plasmid pBSCT5, which now contains a recombinant region deprived of the zot and ctxA functional genes. Then the PstI of pBSCT5 was mutated into EcoRI by insertion of an EcoRI linker to obtain pBSCT64 and the resultant EcoRI fragment was subcloned into the EcoRI site of pGP704 to obtain pAJF. (b) To construct strains affected in the expression of HA/P the suicide plasmid pGPH6 was used. This plasmid was constructed in different steps. First, plasmid pCH2 (Hase y Finkelstein, 1991, J. Bacteriology 173:3311-3317) that contains the hap gene in a 3,2 kb HindIII fragment from V. cholerae 3083 was linealized by the StuI site, which is situated in the hap coding sequence. The 3.2 kb HindIII-fragment containing the celA gene was excised from plasmid pCT104 (Cornet y cols, 1983, Biotechnology 1:589-594) and subcloned into the StuI site of pCH2 to obtain pAHC3. The insert containing of pAHC3, containing the hap gene insertionally inactivated with the celA gene, was subcloned as a HindIII fragment to a pUC19 derivative that have the multiple cloning site flanked by BglII sites to obtain pIJHCI. The Bgl II fragment of this plasmid was subcloned into pGP704 to originate pGPH6, which contains a 6.4 kb fragment with the genetic hap::celA structure, where the hap gene is not functional. (c) y (d) When constructing mutants in the lysA or metF genes, the suicide plasmids pCVlysAΔl or pCVMΔClaI were used. To construct these plasmids, the lysA y metF genes were PCR amplified from V. cholerae C7258, using a pair of oligonucleotides for each gene. The oligonucleotides were purchased from Centro de Ingeniería Génetica y Biotecnología, Ciudad de La Habana, Cuba. The nucleotide sequesnces of the primers were: (lysA): (P 6488) 5′-GTA AAT CAC GCT ACT AAG-3′ and (P 6487) 5′-AGA AAA ATG GAA ATGC-3′ and (metF): (P 5872) 5′-AGA GCA TGC GGC ATG GC-3′ and (P 5873) 5′-ATA CTG CAG CTC GTC GAA ATG GCG-3′. The amplicons were cloned into the plasmids pGEM®T (Promega) and pIJ2925 (Janssen y cols, 1993, Gene 124:133-134), leading to the obtainment of the recombinant plasmids pGlysA3 y pMF29, which contain active copies of the lysA y metF genes, respectively. The identity of each gene was checked by nucleotide sequencing.
[0102] The metF and lysA genes cloned were mutated in vitro by deletion of the respective ClaI (246 base pairs) and PstI/AccI (106 base pairs) inner fragments, respectively. In the last of the cases the strategy was designed to keep the open reading frame leading to an inactive gene product to avoid exerting polar effects during and after construction of a lysA mutant of V. cholerae . Each inactivated gen was cloned as a Bgl II fragment in the suicide vector pCVD442 for the subsequent introduction into the cholera vaccine candidates of interest. The suicide plasmid containing the lysA alelle was termed pCVlysAΔl and the one containing the metF alelle was denominated pCVMΔClaI.
(e) When constructing mutants of the VC0934 gene we constructed and used the suicide plasmid pCVDΔ34. In doing that, the VC0934 gene was PCR amplified using as template total DNA from strain N16961 and the primers: 5′-GCA TGC GTC TAG TGA TGA AGG-3′ y 5′-TCT AGA CTG TCT TAA TAC GC-3′. The amplicon was cloned into the plasmid pGEM5Zf T-vector to obtain plasmid pGEM34; a 270 base pair deletion was performed inside the VC0934 coding sequence using the restriction enzymes NarI/BglII. After flushing the ends with klenow and subsequent recircularization the plasmid obtained was named pG34. The resultant inactive gene was subcloned into the suicide vector pCVD442 digested with SalI and SphI to obtain the plasmid pCVΔ34. This plasmid was used to make the allelic replacement of the wild type gene. (f) When constructing mutants defective in thyA expression the suicide plasmid pEST was constructed and used. The steps to construct this plasmid comprised the cloning of the thyA gene from V. cholerae C7258 into pBR322 as an EcoRI-HindIII cromosomal DNA fragment, to obtain pVT1 (Valle y cols, 2000, Infection and Immunity 68, No 11, pp6411-6418). A 300 base pairs internal fragment from the thyA gene, comprised between the BglII and MluI, sites was deleted from this plasmid to obtain pVMT1. This deletion removed the DNA fragment that codes for amino acids 7 to 105 of the encoded protein Thimidilate syntase. The mutated thyA gene was excised as an EcoRI-HindIII fragment, the extremes were blunted and then cloned into the SmaI site of pUC19 in the same orientation as the β-galactosidase gene to obtain pVT9. The resultant gene was subcloned as a SacI fragment from pVT9 to pCVD442 and the obtained plasmid was named pEST. This final construct was used to make the allelic replacement of the wild type gene in the strains of interest.
[0105] The described suicide vectors are a modular system that can be used to introduce secuencial mutation into V. cholerae vaccine candidates.
[0106] The allelic replacement with the genes encoded by these vectors is done following the sequence of steps denoted below:
[0107] In the first step the suicide vector, containing the allele of choice among those described, is transferred by conjugation from the E. coli donor SM10λpir to the V. cholerae recipient, this last being the subject of the planned modification. This event is done to produce a cointegrate resistant to ampicillin. The clones resultant from the conjugational event are thus selected in LB plates supplemented with ampicillin (100 μg/ml).
[0108] The procedure for this first stage is as follows. The donor strain, SM10λpir transformed with the sucide vector of interest, is grown in an LB plate (NaCl, 10 g/l; bacteriological triptone, 10 g/l, and yeast extract, 5 g/l), supplemented with ampicillin (100 zg/ml), and the receptor strain, the V. cholerae strain to be modified, is grown in an LB plate. The conditions for growth are 37° C. overnight. A single colony of the donor and one from the receptor is streaked into a new LB plate. The donor strain is streaked firstly in one direction and the receptor ( V. cholerae ) secondly in the opposed orientation. This perpendicular and superimposed streaking warrant that both strain grow in close contact. In the next step the plates are incubated at 37° C. for 12 hours, harvested in 5 ml of NaCl (0.9 %) y 200 μl of dilutions 10 2 , 10 3 , 10 4 and 10 5 are disseminated in LB-ampicillin-polimixinB plates, to select the V. cholerae clones that were transformed with the suicide plasmid and counterselect the donor E. coli SM10λpir. Ten such clones resulting from each process are preserved frozen at −80° C. in LB-glicerol at 20% to be analyzed in the second step.
[0109] In the second step, a Southern blot hybridization is performed with a probe specific for the gene subjected to the mutational process; this is done to detect the structure of the correct cointegrate among the clones conserved in the previous step. The clones in which the suicide plasmid integrated to the correct target by homologous recombination are identified by the presence of a particular cromosomal structure. This structure contains one copy of the wild type gene and one of the mutated allele separated only by plasmid vector sequences. This particular structure produces a specific hybridization pattern in Southern blot with the specific probe that allows its identification. The appropriate clones are conserved frozen at −80° C. in LB glicerol.
[0110] This second step comprises the following substeps: Firstly, the total DNA of each clone obtained in the first step is isolated according to a traditional procedure (Ausubel y cols, Short protocols in Molecular Biology, third edition, 1992, unit 2.4, page 2-11, basic protocol). Total DNA from the progenitor strain is isolated as control. Then, the total DNA of the ten clones the progenitor strain is digested with the appropriate restriction enzymes, to be mentioned subsequently in the document. One μg of DNA are digested from each clone and the mother strain and later electrophoresed in parallel lanes of an agarose gel. The DNA content of the gel is blotted into membranes in alkaline conditions (Ausubel y cols, Short protocols in Molecular Biology, third edition, 1992, unit 2.9 A, page 2-30, alternate protocol 1).
[0111] The blots are fixed by incubation at 80° C. for 15 minutes. The free sites in the membrane are then blocked by prehybridization and subsequently probed with the specific probe for each mutation.
[0112] What follows are the details of the restriction enzyme, the probe (digoxigenin-labelled using the method random primed method) and the size of the hibridization fragment that identify the desired structure for the cointegrate of each clone, according to the target gene:
[0113] For suppression mutants of the CTXΦ phage genes, the total DNA of clones is digested with the restriction enzyme Hind III, and once in the membrane is hybridized with a probe obtained starting from the Pst I-EcoR I fragment of the pBB6 plasmid. The clones of interest are the ones that have the genetic structure that origin two bands in the Southern blot, one of 10 000 base pairs and another of 7 000 base pairs. As control the parental strain origins a single band of 17 000 base pairs in the same experiment of Southern blot.
[0114] For suppression mutants of the hap gene, the total DNA of clones is digested with the restriction enzyme Xho I, and once in the membrane is hybridized with a probe obtained starting from the Hind III fragment of 3 200 base pairs presents in the pCH2 plasmid. The clones of interest are those that have the genetic structure that origins a single band in the Southern blot, of 16 000 base pairs. As control the parental strain generates a single band of 6 000 base pairs in the same experiment of Southern blot.
[0115] For suppression mutants of lysA gene, the total DNA of clones is digested with the restriction enzyme Xho I, and once in the membrane is hybridized with a probe obtained from the Sph I/Sma I fragment of the pCV□lysAl plasmid, contained the mutated gene lysA. The clones of interest are those that have the genetic structure that origins a single band in the Southern blot, of 12 500 base pairs. As control the parental strain generates a single band of 5 200 base pairs in the same experiment of Southern blot.
[0116] For suppression mutants of metF gene, the total DNA of clones is digested with the restriction enzyme Nco I, and once in the membrane is hybridized with a probe obtained from the Bgl II fragment of pCVM□ClaI, contained the mutated metF gene. The clones of interest are those that have the genetic structure that origins a single band in the Southern blot, of 12 000 base pairs. As control the parental strain generates a single band of 5 000 base pairs in the same experiment of Southern blot.
[0117] For suppression mutants of gene VC0934, the total DNA of clones is digested with the restriction enzyme Ava I, and once in the membrane is hybridized with a probe obtained from the Sal I/Sph I fragment of pCVD□34, contained the mutated VC0934 gene. The clones of interest are those that have the genetic structure that origins two bands in the Southern blot, one of 1 600 or 1 900 and another of 8 200 or 7 900 base pairs. As control the parental strain generates a single band of 3 500 base pairs in the same experiment of Southern.
[0118] For suppression mutants in thyA gene, the total DNA of clones is digested with the restriction enzyme Bstx I, and once in the membrane is hybridized with a probe obtained from the Sac I fragment of pEST1, contained the mutated thyA gene. The clones of interest are those that have the genetic structure that origins a single band in the Southern blot, of 9 600 base pairs. As control the parental strain generates a single band of 2 400 base pairs in the same experiment of Southern blot.
[0119] In the third step of the procedure, 3 clones of interest, carrying a cointegrate with one of the previous structures, are cultured in absence of the antibiotic selective pressure to allow the loss of the suicidal vector by means of homologue recombination and the amplification of resultants clones. In said clones the loss of the suicidal vector goes with the loss of one of the two copies of the gene, the mutated or the wild one, of the genetic endowment of the bacteria.
[0120] In a fourth step of the procedure, dilutions of the previous cultures are extended in plates to obtain isolated colonies, which are then replicated toward plates supplemented with ampicillin to evaluate which clones are sensitive to ampicillin. Said clones, sensitive to ampcillin, are conserved for freezing, as described previously.
[0121] In a fifth step, by means of a study of Southern blot with specific probes for each one of the genes of interest (describe in a, b, c, d, and, f) it is verified which clones retained in the chromosome the mutated copy of the allele of interest. These clones of interest are expanded to create a work bank and to carry out their later characterization, as well as the introduction of the modifications object of protection in the present invention application.
[0122] In the following paragraphs we detail the restriction enzyme, the probe and the sizes of the hybridization fragments that identify the desired structure in each of the mutants, according to each of the genes being the subject of modification:
[0123] To analyze the mutants in the CTXΦ prophage, the total DNA is digested with the restriction endonuclease Hind III. Once in the membrane it is hybridized with a probe derived from the Pst I-EcoR I fragment of plasmid pBB6. Are clones of interest such that do not produce hybridization bands in the Southern blot.
[0124] For the mutants with the inactivated allele of hap, total DNA from the clones is digested with the restriction enzyme Xho I and once in the membrane it is hybridized with a probe derived from the 3 200 base pair Hind III fragment from plasmid pCH 2 that codes for the hap gen. The clones of interest are those that produce a single band in the Southern blot, of about 9 000 nucleotide pairs.
[0125] For the mutants in the lysA gene total ADN is digested with the restriction enzyme Xho I, and once in the membrane it is hybridized with a probe derived from the Sph I/Sma I fragment isolated from the plasmid pCVΔlysA, that contain the lysA mutated gene. The clones of interest are those having the genetic structure that produce a single band in Southern blot of about de 5 000 pairs of nucleotides.
[0126] For the mutants with deletions in the metF gene, the total ADN of the clones is digested with the restriction enzyme Nco I, and once in the membrane it is hybridized with a probe derived from the Bgl II fragment contained in plasmid pCVMΔClaI, that contains the metF mutant gene. The clones of interest are those that have the genetic structure that leads to a single band of 4 700 base pairs in the Southern blot.
[0127] For the mutants in the VC0934 gene, total DNA of the clones is digested with the restriction enzyme Ava I, and the blots are hybridized with a probe obtained from the Sal I/Sph I fragment of pCVDΔ34, which contains the VC0934 mutant gene obtained in vitro. The clones of interest are those having the structure leading to a single band of 3 200 base pairs in the Southern blot.
[0128] For the mutants in the thyA gene, total DNA of the clones is digested with the restriction enzyme Bstx I, and the blots are hybridized with a probe obtained from the Sac I fragment of pEST1, which contain the thyA gene. The clones of interest are those that have the genetic structure leading to a single band in the Southern blot of about 2 100 base pairs.
EXAMPLE 7
Methods to Preserve Vaccine Strains by Means of Lyophilization
[0129] In following example microorganisms were cultured in LB broth at 37° C. with an orbital shaking 150 and 250 rpm until reaching the logarithmic phase. Cells were harvested by centrifugation 5000 and 8000 rpm at 4° C. during 10-20 minutes and then were mixed with the formulations that show good protection features of the microorganism, so that the cellular concentration was between 10 8 and 10 9 cells ml −1 . 2 ml were dispensed for each 10R type flask. The lyophilization cycle comprised a deep freezing of the material, a primary drying keeping each product between −30° C. and −39° C. for space of 8 to 12 hours and a secondary drying at temperatures between 18° C. and 25° C. for not more than 12 hours. The viability loss was defined as the logarithmic difference of the CFU/mL before and after the lyophilization or before and after the storage of the lyophilized material, which is always dissolved in a 1.33% sodium bicarbonate solution.
[0000] Formulation L+E+S
[0130] The BLR01, JCG03 and ESP05 strains were processed by the previously described lyophilization process in a formulation of the type L (5.0%), E (2.0%) and S (2.0%). The freezing was performed at −60° C. During the primary drying, the temperature of the product was kept at −32° C. for 10 hours and in the secondary drying the temperature was kept at 22° C. for 12 hours. The dissolution of the lyophilized material in a 1.33% sodium bicarbonate solution was instant. The viability loss calculated immediately after the dissolution, with regard to the concentration of live cells before the lyophilization resulted to be 0.30, 0.43, and 0.60 logarithmic orders for BLR01, JCG03 and ESP05, respectively.
[0000] Comparison of the L+P+S and L+E+S Formulations with that of Skim Milk+Peptone +Sorbitol
[0131] The strain JCG03 was lyophilized using two formulations: the type L (6.0%), P (2.0%) and S (2.0%), and the other type L (5.5%), E (1.8%) and S (1.6%). This strain was also lyophilized in a formulation of 6.0% skim milk, 2.0% peptone and 2.0% sorbitol as a comparison formulation. The freezing was done at −60° C. During the primary drying, the temperature of the product was kept at −33° C. for 12 hours and in the secondary drying the temperature was kept at 20° C. for 14 hours. The dissolution of the lyophilized material in a 1.33% sodium bicarbonate solution was instant when the lyophilization process took place in the formulations of the type L+P+S or L+E+S and slightly slower when was lyophilized in the comparison formulation. The viability loss calculated immediately after the dissolution, with regard to the concentration of live cells before the lyophilization resulted to be 0.48, 0.52 and 0.55 logarithmic orders for the L+P+S, L+E+S and the comparison formulations, respectively, significantly similar.
[0000] Humidity and Oxygen Effects
[0132] The strain JCG03 lyophilized in the three formulations mentioned in the previous paragraph, was exposed immediately after being lyophilized to the simultaneous action of humidity and oxygen. This was achieved, confining the samples during 3 days at 25° C. in an atmosphere in sterile glass desiccators, under an 11% relative humidity (created by a saturated solution of lithium chloride). The viability loss in the L+P+S, L+E+S and comparison formulations resulted to be 1.61, 1.10 and 3.43 logarithmic orders, respectively, what shows that the formulations object of this invention guarantee a bigger protection to humidity and oxygen than the comparison formulation.
[0000] Effect of the Storage Temperature
[0133] The strains TLP01, JCG01 and ESP05 were lyophilized in a formulation of the type L (5.5%), E(2.0%) and S(2.0%). The freezing was done at −58° C. During the primary drying, the temperature of the product was kept at −30° C. for 12 hours and in the secondary drying the temperature was kept at 20° C. for 14 hours. The dissolution in a 1.33%
Vibrio cholerae JCG01 (LMG P-22149) Vibrio cholerae JCG02 (LMG P-22150) Vibrio cholerae JCG03 (LMG P-22151) Vibrio cholerae KMD01 (LMG P-22153) Vibrio cholerae KMD02 (LMG P-22154) Vibrio cholerae KMD03 (LMG P-22155) Vibrio cholerae JCG04 (LMG P-22152) Vibrio cholerae ESP01 (LMG P-22156) Vibrio cholerae ESP02 (LMG P-22157) Vibrio cholerae ESP03 (LMG P-22158) Vibrio cholerae RAF01 (LMG P-22159) Vibrio cholerae TLP01 (LMG P-22160) Vibrio cholerae TLP02 (LMG P-22161) y Vibrio cholerae TLP03 (LMG P-22162)
[0134] sodium bicarbonate solution was instant. The viability loss calculated immediately after the dissolution, with regard to the concentration of live cells before the lyophilization resulted to be 0.43, 0.55 and 0.44 logarithmic orders in TLP01, JCG01 and ESP05, respectively. The lyophilized material was stored 1 year either at 8° C. or −20° C. The Table 3 shows the viability loss results obtained.
TABLE 3 Viability loss (1 year of storage). Strain 8° C. −20° C. TLP01 1.07 0.64 JCG01 1.02 0.59 ESP05 0.91 0.55
EXAMPLE 8
Strains of the Present Invention and Their Characteristics
[0135] The strains of the present invention have been deposited in the Belgium Coordinated Collection of Microorganisms (BCCM). Laboratorium voor Microbiologie-Bacterienverzameling (LMG):
[0136] They are described in Table 4.
TABLE 4 Vaccine strains of the present invention. Wild type parental Biotype/ Strain strain Serotype Relevante Genotype. BLR01 CA385 Classical/Og ΔCTXΦ, hap::celA, ΔmshA BLR02 CA385 Classical/Og ΔCTXΦ, hap::celA, lysA, ΔmshA BLR03 CA385 Classical/Og ΔCTXΦ, hap::celA, metF, ΔmshA EMG01 CA401 Classical/In ΔCTXΦ, hap::celA, ΔmshA EMG02 CA401 Classical/In ΔCTXΦ, hap::celA, lysA, ΔmshA EMG03 CA401 Classical/In ΔCTXΦ, hap::celA, metF, ΔmshA JCG01 C7258 El Tor/Ogawa ΔCTXΦ, hap::celA, MSHA − JCG02 C7258 El Tor/Ogawa ΔCTXΦ, hap::celA, MSHA − JCG03 C7258 El Tor/Ogawa ΔCTXΦ, hap::celA, ΔmshA EVD01 C7258 El Tor/Ogawa ΔCTXΦ, hap::celA, thyA, ΔmshA KMD01 C7258 El Tor/Ogawa ΔCTXΦ, hap::celA, metF, ΔmshA KMD02 C7258 El Tor/Ogawa ΔCTXΦ, hap::celA, lysA, ΔmshA ESP06 C7258 El Tor/Ogawa ΔCTXΦ, hap::celA, ΔVC0934, JCG04 C7258 El Tor/Ogawa ΔCTXΦ, hap::celA, ΔmshA ESP01 C7258 El Tor/Ogawa ΔCTXΦ, hap::celA, metF, ΔmshA ESP02 C7258 El Tor/Ogawa ΔCTXΦ, hap::celA, lysA, ΔmshA ESP04 C7258 El Tor/Ogawa ΔCTXΦ, hap::celA, ΔVC0934, RAF01 C6706 El Tor/Inaba ΔCTXΦ, hap::celA, ΔmshA EVD02 C6706 El Tor/Inaba ΔCTXΦ, hap::celA, thyA, ΔmshA ESP03 C6706 El Tor/Inaba ΔCTXΦ, hap::celA, metF, ΔmshA KMD03 C6706 El Tor/Inaba ΔCTXΦ, hap::celA, lysA, ΔmshA ESP05 C6706 El Tor/Inaba ΔCTXΦ, hap::celA, ΔVC0934, TLP01 CRC266 O139 ΔCTXΦ, hap::celA, ΔmshA TLP02 CRC266 O139 ΔCTXΦ, hap::celA, lysA, ΔmshA TLP03 CRC266 O139 ΔCTXΦ, hap::celA, metF, ΔmshA
[0137] Advantages
[0138] The present invention provide us with a methodology to protect live cholera vaccine candidates from the reacquisition of cholera toxin genes and others toxins from the CTXΦ bacteriophage mediated by VGJΦ phage, and therefore from the conversion to virulence by this mechanism.
[0139] Equally provide us with the necessary information to assure that live cholera vaccine candidates will not spread CTXΦ, in the case that these vaccine candidates reacquire CTXΦ, by a specialized transduction with the VGJΦ phage.
[0140] The present invention provide us the application of MSHA mutants as live cholera vaccine candidates, which exhibits an increase in their environmental safety due to resistance to the infection with CTXΦ mediated by VGJΦ.
[0141] This invention provides us with a new characteristic to keep in mind during the design and construction of live cholera vaccine candidates to improve their environmental safety, that is to say that such vaccines are not able to spread the CTXΦ genes, mediated by VGJΦ, in the case of reacquisition.
[0142] The above characteristic could be applied to the already made live cholera vaccine candidates, which have demonstrated an acceptable level of reactogenicity in volunteers studies, to reduce their potential environmental impact.
[0143] This invention also provide formulations to preserve by lyophilization all of the above-mentioned live cholera vaccine candidates and also improve their abilities to tolerate the remainder of oxygen and humidity in the container.
[0144] These formulations also guarantee the instant reconstitution of the lyophilized live cholera vaccine candidate powder in sodium bicarbonate buffer, making easier the manipulation, protecting the vaccines during this process and improving the organoleptic characteristic, specifically related with the visual aspect of lyophilized tablets and the reconstituted products.
[0145] One of the formulations provided here for conservation and lyophilization of live cholera vaccine candidates lack the bovine components usually added to many formulations to lyophilize human vaccines.
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The present invention discloses new live attenuated strains for oral immunization against cholera that are provided in freeze dried formulations for long term storage and administration to humans. These strains combine the two most important properties of live attenuated cholera vaccine candidates. One such property is being well tolerated by people ingesting them. This was achieved by virtue of mutations already described in the art. The second property is having enhanced environmental safety due to the absence of VGJΦ DNA in their genomes and also due to null mutations in the mshA gene or other spontaneous mutations conducive to the lack of MSHA type IV fimbria on the bacterial surface. This was done envisioning that VGJΦ is a filamentous phage able to recombine with CTXΦ and disseminate the cholera toxin genes. This VGJΦ phage as well as the VGJΦ-CTXΦ recombinants uses the MSHA fibers as receptor. Being devoid of MSHA fimbria the vaccine candidates are protected from acquiring CTXΦ from the recombinant hybrid VGJΦ-CTXΦ. Being devoid of VGJΦ, the vaccine candidates are impaired in the dissemination of CTXΦ, via VGJΦ.
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RELATED APPLICATIONS
[0001] Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet, or any correction thereto, are hereby incorporated by reference into this application under 37 CFR 1.57.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] Programmable thermostats have been available for more than 20 years. Programmable thermostats offer two types of advantages as compared to non-programmable devices. On the one hand, programmable thermostats can save energy in large part because they automate the process of reducing conditioning during times when the space is unoccupied, or while occupants are sleeping, and thus reduce energy consumption.
[0004] On the other hand, programmable thermostats can also enhance comfort as compared to manually changing setpoints using a non-programmable thermostat. For example, during the winter, a homeowner might manually turn down the thermostat from 70 degrees F. to 64 degrees when going to sleep and back to 70 degrees in the morning. The drawback to this approach is that there can be considerable delay between the adjustment of the thermostat and the achieving of the desired change in ambient temperature, and many people find getting out of bed, showering, etc. in a cold house unpleasant. A programmable thermostat allows homeowners to anticipate the desired result by programming a pre-conditioning of the home. So, for example, if the homeowner gets out of bed at 7 AM, setting the thermostat to change from the overnight setpoint of 64 degrees to 70 at 6 AM can make the house comfortable when the consumer gets up. The drawback to this approach is that the higher temperature will cost more to maintain, so the increase in comfort is purchased at the cost of higher energy usage.
[0005] A significant difficulty with this approach is that the amount of preconditioning required to meet a given standard of comfort is a function of several variables. First, the amount of preconditioning required will vary with outside temperature. An HVAC system that might require an hour to increase the temperature in a given home from 64 to 70 degrees when it is 45 degrees outside might take two hours when it is 5 degrees outside. Second, the amount of preconditioning required will vary depending on the relationship between the capacity of the HVAC system and the thermal characteristics of the structure. That is, a high capacity HVAC system in a given structure will achieve a target temperature faster than a smaller system; a well-insulated home with double-glazed windows will respond more quickly to a given HVAC system than an uninsulated home with single-glazed windows will. Consumers can program their thermostats to turn on the furnace early enough that the desired temperature is always reached at the target time even on the coldest days, but the cost of this choice will be wasted energy and money on warmer days. Alternatively, consumers can choose more economical settings, with the cost of loss of comfort on cold days. Similar tradeoffs will be faced when trying to optimize setbacks during the summer in homes that have air conditioning.
[0006] It would therefore be advantageous to have a means for controlling the HVAC system that is capable of taking into account both outside weather conditions and the thermal characteristics of individual homes in order to improve the ability to dynamically achieve the best possible balance between comfort and energy savings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows an example of an overall environment in which an embodiment of the invention may be used.
[0008] FIG. 2 shows a high-level illustration of the architecture of a network showing the relationship between the major elements of one embodiment of the subject invention.
[0009] FIG. 3 shows an embodiment of the website to be used as part of the subject invention.
[0010] FIG. 4 shows a high-level schematic of the thermostat used as part of the subject invention.
[0011] FIG. 5 shows one embodiment of the database structure used as part of the subject invention.
[0012] FIGS. 6 a and 6 b show how comparing inside temperature against outside temperature and other variables permits calculation of dynamic signatures.
[0013] FIG. 7 shows a flow chart for a high level version of the process of calculating the appropriate turn-on time in a given home.
[0014] FIG. 8 shows a more detailed flowchart listing the steps in the process of calculating the appropriate turn-on time in a given home.
[0015] FIGS. 9 a , 9 b , 9 c , and 9 d show the steps shown in the flowchart in FIG. 8 in the form of a graph of temperature and time.
[0016] FIG. 10 shows a table of some of the data used by the subject invention to predict temperatures.
[0017] FIG. 11 shows the subject invention as applied in a specific home on a specific day.
[0018] FIG. 12 shows the subject invention as applied in a different specific home on a specific day.
[0019] FIGS. 13-1 and 13-2 show a table of predicted rates of change in temperature inside a given home for a range of temperature differentials between inside and outside.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] FIG. 1 shows an example of an overall environment 100 in which an embodiment of the invention may be used. The environment 100 includes an interactive communication network 102 with computers 104 connected thereto. Also connected to network 102 are one or more server computers 106 , which store information and make the information available to computers 104 . The network 102 allows communication between and among the computers 104 and 106 .
[0021] Presently preferred network 102 comprises a collection of interconnected public and/or private networks that are linked to together by a set of standard protocols to form a distributed network. While network 102 is intended to refer to what is now commonly referred to as the Internet, it is also intended to encompass variations which may be made in the future, including changes additions to existing standard protocols.
[0022] One popular part of the Internet is the World Wide Web. The World Wide Web contains a large number of computers 104 and servers 106 , which store HyperText Markup Language (HTML) documents capable of displaying graphical and textual information. HTML is a standard coding convention and set of codes for attaching presentation and linking attributes to informational content within documents.
[0023] The servers 106 that provide offerings on the World Wide Web are typically called websites. A website is often defined by an Internet address that has an associated electronic page. Generally, an electronic page is a document that organizes the presentation of text graphical images, audio and video.
[0024] In addition to the Internet, the network 102 can comprise a wide variety of interactive communication media. For example, network 102 can include local area networks, interactive television networks, telephone networks, wireless data systems, two-way cable systems, and the like.
[0025] Network 102 can also comprise servers 106 that provide services other than HTML documents. Such services may include the exchange of data with a wide variety of “edge” devices, some of which may not be capable of displaying web pages, but that can record, transmit and receive information.
[0026] In one embodiment, computers 104 and servers 106 are conventional computers that are equipped with communications hardware such as a modem or a network interface card. The computers include processors such as those sold by Intel and AMD. Other processors may also be used, including general-purpose processors, multi-chip processors, embedded processors and the like.
[0027] Computers 104 can also be handheld and wireless devices such as personal digital assistants (PDAs), cellular telephones and other devices capable of accessing the network.
[0028] Computers 104 utilize a browser configured to interact with the World Wide Web. Such browsers may include Microsoft Explorer, Mozilla, Firefox, Opera or Safari. They may also include browsers used on handheld and wireless devices.
[0029] The storage medium may comprise any method of storing information. It may comprise random access memory (RAM), electronically erasable programmable read only memory (EEPROM), read only memory (ROM), hard disk, floppy disk, CD-ROM, optical memory, or other method of storing data.
[0030] Computers 104 and 106 may use an operating system such as Microsoft Windows, Apple Mac OS, Linux, Unix or the like.
[0031] Computers 106 may include a range of devices that provide information, sound, graphics and text, and may use a variety of operating systems and software optimized for distribution of content via networks.
[0032] FIG. 2 illustrates in further detail the architecture of the specific components connected to network 102 showing the relationship between the major elements of one embodiment of the subject invention. Attached to the network are thermostats 108 and computers 104 of various users. Connected to thermostats 108 are HVAC units 110 . The HVAC units may be conventional air conditioners, heat pumps, or other devices for transferring heat into or out of a building. Each user is connected to the servers 106 via wired or wireless connection such as Ethernet or a wireless protocol such as IEEE 802.11, a gateway or wireless access point 112 that connects the computer and thermostat to the Internet via a broadband connection such as a digital subscriber line (DSL) or other form of broadband connection to the World Wide Web. In one embodiment, thermostat management server 106 is in communication with the network 102 . Server 106 contains the content to be served as web pages and viewed by computers 104 , as well as databases containing information used by the servers, and applications used to remotely manage thermostats 108 .
[0033] In the currently preferred embodiment, the website 200 includes a number of components accessible to the user, as shown in FIG. 3 . Those components may include a means to store temperature settings 202 , a means to enter information about the user's home 204 , a means to enter the user's electricity bills 206 , and means to elect to enable the subject invention 208 .
[0034] FIG. 4 shows a high-level block diagram of thermostat 108 used as part of the subject invention. Thermostat 108 includes temperature sensing means 252 , which may be a thermistor, thermal diode or other means commonly used in the design of electronic thermostats. It includes a microprocessor 254 , memory 256 , a display 258 , a power source 260 , at least one relay 262 , which turns the HVAC system on and off in response to a signal from the microprocessor, and contacts by which the relay is connected to the wires that lead to the HVAC system. To allow the thermostat to communicate bi-directionally with the computer network, the thermostat also includes means 264 to connect the thermostat to a local computer or to a wired or wireless network. Such means could be in the form of Ethernet, wireless protocols such as IEEE 802.11, IEEE 802.15.4, Bluetooth, or other wireless protocols. The thermostat may be connected to the computer network directly via wired or wireless Internet Protocol connection. Alternatively, the thermostat may connect wirelessly to a gateway such as an IP-to-Zigbee gateway, an IP-to-Z-wave gateway, or the like. Where the communications means enabled include wireless communication, antenna 266 will also be included. The thermostat 108 may also include controls 268 allowing users to change settings directly at the thermostat, but such controls are not necessary to allow the thermostat to function.
[0035] The data used to generate the content delivered in the form of the website and to automate control of thermostat 108 is stored on one or more servers 106 within one or more databases. As shown in FIG. 5 , the overall database structure 300 may include temperature database 400 , thermostat settings database 500 , energy bill database 600 , HVAC hardware database 700 , weather database 800 , user database 900 , transaction database 1000 , product and service database 1100 and such other databases as may be needed to support these and additional features.
[0036] The website will allow users of connected thermostats 108 to create personal accounts. Each user's account will store information in database 900 , which tracks various attributes relative to users. Such attributes may include the make and model of the specific HVAC equipment in the user's home; the age and square footage of the home, the solar orientation of the home, the location of the thermostat in the home, the user's preferred temperature settings, etc.
[0037] As shown in FIG. 3 , the website 200 will permit thermostat users to perform through the web browser substantially all of the programming functions traditionally performed directly at the physical thermostat, such as temperature set points, the time at which the thermostat should be at each set point, etc. Preferably the website will also allow users to accomplish more advanced tasks such as allow users to program in vacation settings for times when the HVAC system may be turned off or run at more economical settings, and to set macros that will allow changing the settings of the temperature for all periods with a single gesture such as a mouse click.
[0038] In addition to using the system to allow better signaling and control of the HVAC system, which relies primarily on communication running from the server to the thermostat, the bi-directional communication will also allow the thermostat 108 to regularly measure and send to the server information about the temperature in the building. By comparing outside temperature, inside temperature, thermostat settings, cycling behavior of the HVAC system, and other variables, the system will be capable of numerous diagnostic and controlling functions beyond those of a standard thermostat.
[0039] For example, FIG. 6 a shows a graph of inside temperature, outside temperature and HVAC activity for a 24 hour period. When outside temperature 302 increases, inside temperature 304 follows, but with some delay because of the thermal mass of the building, unless the air conditioning 306 operates to counteract this effect. When the air conditioning turns on, the inside temperature stays constant (or rises at a much lower rate or even falls) despite the rising outside temperature. In this example, frequent and heavy use of the air conditioning results in only a very slight temperature increase inside the house of 4 degrees, from 72 to 76 degrees, despite the increase in outside temperature from 80 to 100 degrees.
[0040] FIG. 6 b shows a graph of the same house on the same day, but assumes that the air conditioning is turned off from noon to 7 PM. As expected, the inside temperature 304 a rises with increasing outside temperatures 302 for most of that period, reaching 88 degrees at 7 PM. Because server 106 logs the temperature readings from inside each house (whether once per minute or over some other interval), as well as the timing and duration of air conditioning cycles, database 300 will contain a history of the thermal performance of each house. That performance data will allow the server 106 to calculate an effective thermal mass for each such structure—that is, the speed with the temperature inside a given building will change in response to changes in outside temperature. Because the server will also log these inputs against other inputs including time of day, humidity, etc. the server will be able to predict, at any given time on any given day, the rate at which inside temperature should change for given inside and outside temperatures.
[0041] The ability to predict the rate of change in inside temperature in a given house under varying conditions may be applied by in effect holding the desired future inside temperature as a constraint and using the ability to predict the rate of change to determine when the HVAC system must be turned on in order to reach the desired temperature at the desired time.
[0042] FIG. 7 shows a flowchart illustrating the high-level process for controlling a just-in-time (JIT) event. In step 1002 , the server determines whether a specific thermostat 108 is scheduled to run the preconditioning program. If, not, the program terminates. If it so scheduled, then in step 1004 the server retrieves the predetermined target time when the preconditioning is intended to have been completed (TT). Using TT as an input, in step 1006 the server then determines the time at which the computational steps required to program the preconditioning event will be performed (ST). In step 1008 , performed at start time ST, the server begins the process of actually calculating the required parameters, as discussed in greater detail below. Then in 1010 specific setpoint changes are transmitted to the thermostat so that the temperature inside the home may be appropriately changed as intended.
[0043] FIG. 8 shows a more detailed flowchart of the process. In step 1102 , the server retrieves input parameters used to create a JIT event. These parameters include the maximum time allowed for a JIT event for thermostat 108 (MTI); the target time the system is intended to hit the desired temperature (TT); and the desired inside temperature at TT (TempTT). It is useful to set a value for MTI because, for example, it will be reasonable to prevent the HVAC system from running a preconditioning event if it would be expected to take 8 hours, which might be prohibitively expensive.
[0044] In step 1104 , the server retrieves data used to calculate the appropriate start time with the given input parameters. This data includes a set of algorithmic learning data (ALD), composed of historic readings from the thermostat, together with associated weather data, such as outside temperature, solar radiation, humidity, wind speed and direction, etc; together with weather forecast data for the subject location for the period when the algorithm is scheduled to run (the weather forecast data, or WFD). The forecasting data can be as simple as a listing of expected temperatures for a period of hours subsequent to the time at which the calculations are performed, to more detailed tables including humidity, solar radiation, wind, etc. Alternatively, it can include additional information such as some or all of the kinds of data collected in the ALD.
[0045] In step 1106 , the server uses the ALD and the WFD to create prediction tables that determine the expected rate of change or slope of inside temperature for each minute of HVAC cycle time (ΔT) for the relevant range of possible pre-existing inside temperatures and outside climatic conditions. An example of a simple prediction table is illustrated in FIG. 13 .
[0046] In step 1108 , the server uses the prediction tables created in step 1106 , combined with input parameters TT and Temp(TT) to determine the time at which slope ΔT intersects with predicted initial temperature PT. The time between PT and TT is the key calculated parameter: the preconditioning time interval, or PTI.
[0047] In step 1110 , the server checks to confirm that the time required to execute the pre-conditioning event PTI does not exceed the maximum parameter MTI. If PTI exceeds MTI, the scheduling routine concludes and no ramping setpoints are transmitted to the thermostat.
[0048] If the system is perfect in its predictive abilities and its assumptions about the temperature inside the home are completely accurate, then in theory the thermostat can simply be reprogrammed once—at time PT, the thermostat can simply be reprogrammed to Temp(TT). However, there are drawbacks to this approach. First, if the server has been overly conservative in its predictions as to the possible rate of change in temperature caused by the HVAC system, the inside temperature will reach TT too soon, thus wasting energy and at least partially defeating the purpose of running the preconditioning routine in the first place. If the server is too optimistic in its projections, there will be no way to catch up, and the home will not reach Temp(TT) until after TT. Thus it would be desirable to build into the system a means for self-correcting for slightly conservative start times without excessive energy use. Second, the use of setpoints as a proxy for actual inside temperatures in the calculations is efficient, but can be inaccurate under certain circumstances. In the winter (heating) context, for example, if the actual inside temperature is a few degrees above the setpoint (which can happen when outside temperatures are warm enough that the home's natural “set point” is above the thermostat setting), then setting the thermostat to Temp(TT) at time PT will almost certainly lead to reaching TT too soon as well.
[0049] The currently preferred solution to both of these possible inaccuracies is to calculate and program a series of intermediate settings between Temp(PT) and Temp(TT) that are roughly related to AT.
[0050] Thus if MTI is greater than PTI, then in step 1112 the server calculates the schedule of intermediate setpoints and time intervals to be transmitted to the thermostat. Because thermostats cannot generally be programmed with steps of less than 1 degree F., ΔT is quantized into discrete interval data of at least 1 degree F. each. For example, if Temp(PT) is 65 degrees F., Temp(TT) is 72 degrees F., and PT is 90 minutes, the thermostat might be programmed to be set at 66 for 10 minutes, 67 for 12 minutes, 68 for 15 minutes, etc. The server may optionally limit the process by assigning a minimum programming interval (e.g., at least ten minutes between setpoint changes) to avoid frequent switching of the HVAC system, which can reduce accuracy because of the thermostat's compressor delay circuit, which may prevent quick corrections. The duration of each individual step may be a simple arithmetic function of the time PTI divided by the number of whole-degree steps to be taken; alternatively, the duration of each step may take into account second order thermodynamic effects relating to the increasing difficulty of “pushing” the temperature inside a house further from its natural setpoint given outside weather conditions, etc. (that is, the fact that on a cold winter day it may take more energy to move the temperature inside the home from 70 degrees F. to 71 than it does to move it from 60 degrees to 61).
[0051] In step 1114 , the server schedules setpoint changes calculated in step 1112 for execution by the thermostat.
[0052] With this system, if actual inside temperature at PT is significantly higher than Temp(PT), then the first changes to setpoints will have no effect (that is, the HVAC system will remain off), and the HVAC system will not begin using energy, until the appropriate time, as shown in FIG. 12 . Similarly, if the server has used conservative predictions to generate ΔT, and the HVAC system runs ahead of the predicted rate of change, the incremental changes in setpoint will delay further increases until the appropriate time in order to again minimize unnecessary energy use, as shown in FIG. 11 .
[0053] FIG. 9( a ) through 9( d ) shows the steps in the preconditioning process as a graph of temperature and time. FIG. 9( a ) shows step 1102 , in which inputs target time TT 1202 , target temperature Temp(TT) 1204 , maximum conditioning interval MTI 1206 and the predicted inside temperature during the period of time the preconditioning event is likely to begin Temp(TT) 1204 are retrieved.
[0054] FIG. 9( b ) shows the initial calculations performed in step 1108 , in which expected rate of change in temperature ΔT 1210 inside the home is generated from the ALD and WFD using Temp(TT) 1204 at time TT 1202 as the endpoint.
[0055] FIG. 9( c ) shows how in step 1108 ΔT 1210 is used to determine start time PT 1212 and preconditioning time interval PTI 1214 . It also shows how in step 1110 the server can compare PTI with MTI to determine whether or not to instantiate the pre-conditioning program for the thermostat.
[0056] FIG. 9( d ) shows step 1112 , in which specific ramped setpoints 1216 are generated. Because of the assumed thermal mass of the system, actual inside temperature at any given time will not correspond to setpoints until some interval after each setpoint change. Thus initial ramped setpoint 1216 may be higher than Temp(PT) 1208 , for example.
[0057] FIG. 10 shows an example of the types of data that may be used by the server in order to calculate ΔT 1210 . Such data may include inside temperature 1302 , outside temperature 1304 , cloud cover 1306 , humidity 1308 , barometric pressure 1310 , wind speed 1312 , and wind direction 1314 .
[0058] Each of these data points should be captured at frequent intervals. In the preferred embodiment, as shown in FIG. 10 , the interval is once every 60 seconds.
[0059] FIG. 11 shows application of the subject invention in an actual house. Temperature and setpoints are plotted for the 4-hour period from 4 AM to 8 AM with temperature on the vertical axis and time on the horizontal axis. The winter nighttime setpoint 1402 is 60 degrees F.; the morning setpoint temperature 1404 is 69 degrees F. The outside temperature 1406 is approximately 45 degrees F. The target time TT 1408 for the setpoint change to morning setting is 6:45 AM. In the absence of the subject invention, the homeowner could program the thermostat to change to the new setpoint at 6:45, but there is an inherent delay between a setpoint change and the response of the temperature inside the home. (In this home on this day, the delay is approximately fifty minutes.) Thus if the homeowner truly desired to achieve the target temperature at the target time, some anticipation would be necessary. The amount of anticipation required depends upon numerous variables, as discussed above.
[0060] After calculating the appropriate slope ΔT 1210 by which to ramp inside temperature in order to reach the target as explained above, the server transmits a series of setpoints 1216 to the thermostat because the thermostat is presumed to only accept discrete integers as program settings. (If a thermostat is capable of accepting finer settings, as in the case of some thermostats designed to operate in regions in which temperature is generally denoted in Centigrade rather than Fahrenheit, which accept settings in half-degree increments, tighter control may be possible.) In any event, in the currently preferred embodiment of the subject invention, programming changes are quantized such that the frequency of setpoint changes is balanced between the goal of minimizing network traffic and the frequency of changes made on the one hand and the desire for accuracy on the other. Balancing these considerations may result in some cases in either more frequent changes or in larger steps between settings. As shown in FIG. 11 , the setpoint “stairsteps” from 60 degrees F. to 69 degrees F. in nine separate setpoint changes over a period of 90 minutes.
[0061] Because the inside temperature when the setpoint management routine was instantiated at 5:04 AM was above the “slope” and thus above the setpoint, the HVAC system was not triggered and no energy was used unnecessarily heating the home before such energy use was required. Actual energy usage does not begin until 5:49 AM.
[0062] FIG. 12 shows application of the subject invention in a different house during a similar four hour interval. In FIG. 12 , the predicted slope ΔT 1210 is less conservative relative to the actual performance of the home and HVAC system, so there is no off cycling during the preconditioning event—the HVAC system turns on at approximately 4:35 AM and stays on continuously during the event. The home reaches the target temperature Temp(TT) roughly two minutes prior to target time TT.
[0063] FIG. 13 shows a simple prediction table. The first column 1602 lists a series of differentials between outside and inside temperatures. Thus when the outside temperature is 14 degrees and the inside temperature is 68 degrees, the differential is −54 degrees; when the outside temperature is 94 degrees and the inside temperature is 71 degrees, the differential is 13 degrees. The second column 1604 lists the predicted rate of change in inside temperature ΔT 1210 assuming that the furnace is running in terms of degrees Fahrenheit of change per hour. A similar prediction table will be generated for predicted rates of change when the air conditioner is on; additional tables may be generated that predict how temperatures will change when the HVAC system is off.
[0064] Alternatively, the programming of the just-in-time setpoints may be based not on a single rate of change for the entire event, but on a more complex multivariate equation that takes into account the possibility that the rate of change may be different for events of different durations.
[0065] The method for calculating start times may also optionally take into account not only the predicted temperature at the calculated start time, but may incorporate measured inside temperature data from immediately prior to the scheduled start time in order to update calculations, or may employ more predictive means to extrapolate what inside temperature based upon outside temperatures, etc.
[0066] Additional means of implementing the instant invention may be achieved using variations in system architecture. For example, much or even all of the work being accomplished by remote server 106 may also be done by thermostat 108 if that device has sufficient processing capabilities, memory, etc. Alternatively, these steps may be undertaken by a local processor such as a local personal computer, or by a dedicated appliance having the requisite capabilities, such as gateway 112 .
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Systems and methods for reducing the cycling time of a climate control system. For example, one or more of the exemplary systems can receive from a database a target time at which a structure is desired to reach a target temperature. In addition, the system acquires the temperature inside the structure and the temperature outside the structure at a time prior to the target time. The systems use a thermal characteristic of the structure and a performance characteristic of the climate control system, to determine the appropriate time prior to the target time at which the climate control system should turn on based at least in part on the structure, the climate control system, the inside temperature and the outside temperature. The systems then set a setpoint on a thermostatic controller to control the climate control system.
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This application claims the benefit of Belgian Application No. 2002/0301 filed May 7, 2002.
BACKGROUND OF THE INVENTION
The invention relates to a device for attaching and guiding at least one tackle cord in a Jacquard machine, the device being provided for being attached to a part of the Jacquard machine and being provided for being attached to at least one tackle cord.
Jacquard machines are provided with a tackle device in order to obtain the open shed principle and/or to obtain a boosting of movement for lifting. In such a tackle device an end of the lower tackle cords is attached to a grid or a frame. This end of the lower tackle cord is called the fixed end of the tackle cord. The other end of the lower tackle cord is connected to one or several cords of the harness in order to carry out the lifting of the Jacquard heddles. This end is called the movable end of the lower tackle cords.
The grid to which the fixed end of the lower tackle cord is attached, may be attached to the frame of the Jacquard machine, adjustable as to height or may also be connected to a mechanism to carry out an up and down movement. Thus, in BE 1 008 974 a tackle grid moving up and down is discussed and in EP 0 219 437 an implementation is represented in which the fixed ends of the tackle cords are attached fixedly and unadjustably to the guiding walls of the tackle.
Devices with adjustable tackle grids have the advantage that the height of the heddle eyes of the Jacquard heddles may be adjusted without having the complete Jacquard machine to be adjusted as to height by a simple adjustment as to height of the tackle grid.
To attach the fixed end of the tackle cords, various embodiments are known. A first embodiment is represented in BE 1 008 974, where the fixed end of the lower tackle cords is hingedly attached to a claw-shaped reed, by means of a T-shaped anchor of synthetic material extruded to form one piece with the cord.
A disadvantage of this device is that, to replace the lower tackle cord in case of possible rupture or wear, the T-shaped anchor must be pushed out of the claw-shaped reed. However, this operation is not too easy to carry out because of the poor accessibility to the rows of the tackle grid.
Another inconvenience is that no guide is provided for guiding the movable ends of the tackle cords. Therefore the tackle cords may rub against the grid bars when the tackle cords are breaking out sideways in case of rapid up and down movements and the return spring device of the harness fails, for a short while, for one reason or another.
Further, a tackle cord connection is known, which indeed provides a guiding eye for the movable tackle cord. The connection consists of an I-shaped piece made of synthetic material in which the fixed end of the tackle cord of the lower tackle cord is maintained in the upper surface in a claw-shaped part as described above and in which down at the base guiding eyes have been provided for the movable end of the lower tackle cord.
It is first of all an inconvenience that the tackle cord still has to be hooked on a claw-shaped part.
Another problem is that several tackle cords are attached to one little block. The I-shaped attachments are stuck onto metal supporting strips, which are attached to the grid. To replace an I-shaped block, the strip has to be pushed out of all the other blocks of one row. This is a very time-consuming operation.
Moreover, with such a device, the pitch of the Jacquard machine is not well respected, because the blocks may get shifted on the metal strip. This causes the danger that the tackle cords may be pulled out of position, in a slanting position causing wear and tear of the guiding of the hooks. Further, the claws at the ends of a block are weak.
SUMMARY OF THE INVENTION
The purpose of the invention is to provide for a device for attaching and guiding at least one tackle cord in a Jacquard machine not having the above-mentioned disadvantages. It is likewise a purpose of the invention:
to provide for the attachment and guiding of at least one tackle cord which will not come loose under the influence of the load occurring during operation; to provide for a device which is not slidable on the grid bar, so that the pitch of the hooks of the Jacquard machine can be maintained and the tackle cords will not get out of position. to provide for a more compact device.
These purposes are attained by providing for a device for attaching and guiding of at least one tackle cord in a Jacquard machine, the device being provided for being attached to a part of the Jacquard machine and being provided for being connected to at least one tackle cord and the device being provided with a springy element exercising a pushing force on the device in a direction opposite to the tractive effort exercised on the device by the tackle cord.
This has the advantage that the attachment and guiding of at least one tackle cord cannot come loose when the tackle cord is pulling at the device during operation. The device, which has been positioned on a part of the Jacquard machine, is further maintained in position in such a manner.
In a preferred embodiment of the invention, the device is provided with at least one projection which may be brought into a corresponding opening in said part of the Jacquard machine and the projection has a variable form or dimensions, the extremity of the projection having a form or dimensions larger than the form or the dimensions of said opening, such that the projection brought into the opening is situated in a blocking position opposite the opening.
In a more specific preferred embodiment of the invention, the device is provided with two projections, namely a first and a second projection, which have been designed in order to be brought into a first and a second opening respectively.
In a still more specific preferred embodiment of the invention, the two projections have an at least partly cylindrical form having two or more diameters, the extremities of the projections having the largest diameter and the part situated between this extremity and the attachment of the projections to the device having the smallest diameter.
In a specific preferred embodiment of the device according to the invention, said second opening comprises two partial openings, a first partial opening having a diameter which is larger than the extremities of the second projection and a second opening having a diameter which is larger than or fitting for this part situated between the extremity and the attachment of the projections of the device.
In a still more specific preferred embodiment of the device according to the invention, these said partial openings are open circles, there being an opening angle between the two circles which is less than 180° and the second projection being provided with a third part, situated between said extremity of the projection and said second part, the diameter being larger than the diameter of said second part and smaller than the diameter of the extremity of the second projection and it being not possible to shift said third part through said opening angle, but having indeed a diameter which is fitting for or smaller than the diameter of the second partial opening of said second opening.
A similar projection and similar recesses as described above being provided has the advantage that the device is maintained in the part of the Jacquard machine mentioned above in an unambiguous manner. Further, it is not possible to detach the device without exercising a downward force on the device against the force exercised on the device by the springy element. Applying said device to the above-mentioned part of the Jacquard machine occurs by a combination of horizontal and vertical movements, the horizontal movement near the part being less than 10 mm, allowing the Jacquard machine being kept compact. Because the device is well accessible, the height of the tackle cord may be kept limited, while the operator has yet sufficient access to locate and replace the tackle cords. This has a direct influence on the installation height of the complete installation, which, in such manner, may be kept more compact.
In a preferred embodiment of the device according to the invention, said part of the Jacquard machine is a retaining plate on which one or more devices may be installed.
In a particularly advantageous embodiment of the device according to the invention, said device is provided with at least one recess, having the form of the corresponding tool for installing or removing one or several devices.
In a particularly preferred embodiment of the device according to the invention, the device is provided with two recesses, at least one recess having a bulge which fits into an opening, said bulge and said opening having been designed such that when sliding the tool on the said device, the tool will slide over the bulge in a springy manner, until the opening in the tool encloses the bulge of the device.
This has the advantage that the device can only be removed from the retaining plate by the reactive forces coming into being when the device is maintained in the retaining plate. In this manner, also several devices according to the invention may be interchanged by means of a suitable tool, so that this operation is suitable for automation.
Another problem of the devices known is that the anchoring point lies at the top and the guide eye at the bottom, because of which a kind of a channel is formed between two grid bars situated next to one another, in which a lot of dust will be accumulated during the weaving process. In case it might be desirable to blow away the dust from the tackle grids by means of a jet of compressed air, the dust is likely to be blown into the channel and the harness cords will be dragged through this dust. This causes premature wear and tear of the end of the movable tackle cord of the lower tackle cord.
A further purpose of the invention consists in providing a device for attaching at least one tackle cord, providing a guide for the free end, and where no dust collecting channel will be formed by two rows situated next to one another.
This purpose is obtained by providing a device according to the invention, the top of the device comprising at least one plane inclining downwards towards the side.
Another problem of the known tackle cord connections being provided with a guide eye for the movable tackle cord, is that the guide eyes are situated at the bottom of the tackle cord connection, because of which, by pulling the guide eye to the front, there is indeed a good visibility all around the tackle cord, but pulling the tackle cord through the guide eye in the rear still requires quite some groping and searching.
A further purpose of the invention therefore is to provide a device for attaching at least one tackle cord having a guide which may be speedily heddled and where an individual replacement should be possible, the attachment of a tackle cord being easily to locate and to be reached.
This purpose is attained because the device comprises two guide eyes, being situated at different levels.
This has the advantage that the device may be attached to said part of the Jacquard machine in such a manner that the guide eye situated lowest is placed at the front, such that the guide eye is well in sight, while the guide eye placed uppermost is placed at the back and visibility is well enough for the tackle cord to be pulled through the guide eye.
The purpose of the invention is further attained by providing a Jacquard machine equipped with a fixed, adjustable or movable grid and a number of retaining plates, which are attached to the grid and which are designed for attaching a number of devices according to one of the claims mentioned above.
The characteristics and particulars of the present invention are explained hereafter by means of an exemplifying embodiment, making reference to the attached drawings. It should be noted that specific aspects of this example are described only as a preferred example of what is intended in the scope of the above-mentioned general description of the invention and may on no account be interpreted as a restriction of the scope of the invention as such and as expressed in the following claims.
In the attached drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective top view of a device according to the invention, provided with two lower tackle cords;
FIG. 2 is a perspective front view of a fastening clip according to the invention;
FIG. 3 is a perspective top view of a tool for installing or removing one or several fastening clips according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The device for attaching and guiding at least one tackle cord consists of a fastening clip ( 1 ), operating two adjoining rows of lower tackle cords ( 2 ), as shown in FIG. 1 . Each lower tackle cord ( 2 ) is connected to the upper tackle cords (not represented in the figure) through a tackle element ( 3 ) equipped with two tackle pulleys ( 4 , 5 ). The lower tackle cord ( 3 ) is divided into a movable tackle cord end ( 6 ) and a fixed tackle cord end ( 7 ) by the lower tackle pulley ( 5 ).
As shown in the FIGS. 1 and 2 , the fastening clip ( 1 ) is extruded to form one piece with the fixed tackle cord end ( 6 ) of the lower tackle cord ( 2 ). Integral extruding occurs over the total height of the fastening clip ( 1 ) and therefore produces a good attachment of the tackle cord ( 2 ) to the fastening clip ( 1 ). The fastening clip ( 1 ) is provided with two projecting ears, namely a first ear ( 8 a ) and a second ear ( 8 b ). These ears ( 8 a , 8 b ) are provided with a vertically directed guide eye ( 9 ) for the movable tackle cord end ( 7 ). The first ear ( 8 a ) which is situated lowest on the fastening clip ( 1 ) is placed at the back. In such a manner the visual range is good for pulling the tackle cord ( 2 ) through the guide eyes ( 9 ), which are situated in the ears ( 8 a , 8 b ). The dimensions of the guide eyes ( 9 ) are such, that by slightly moving away from one another the holes in the baseplate (not represented in the figure) through which the tackle cords are heddled, the tackle cords have a certain pre-tension and will rub against the side of the guide eyes ( 9 ) because of which the tackle cords ( 2 ) are well guided.
The top ( 10 ) of the fastening clip ( 1 ) is provided with at least a plane ( 11 ) inclining downwards to the side, helping to prevent the dust from accumulating, but allowing it to escape downwards.
Through two projections, a first projection ( 12 a ) and a second projection ( 12 b ), the fastening clip ( 1 ) is attached to a retaining plate ( 20 ), provided with a first ( 21 a ) and a second opening ( 21 b ) to insert the respective projections ( 12 a , 12 b ).
The projections ( 12 a , 12 b ) have variable forms or dimensions, the extremities ( 13 a , 13 b ) of the projections ( 12 a , 12 b ) having the largest forms or dimensions, and the second parts ( 14 a , 14 b ) situated between these extremities ( 13 a , 13 b ) and the attachments of the projections ( 12 a , 12 b ) to the fastening clip ( 1 ) having the smallest forms and dimensions.
The first projection ( 12 a ) partly has a cylindrical form, more particularly the second part ( 14 a ) situated between the extremity ( 13 a ) and the attachment of the first projection ( 2 a ) to the fastening clip ( 1 ). The extremity ( 13 b ), however, is not cylindrical.
The entire second projection ( 12 b ) has a cylindrical form, yet a third part ( 17 b ) being provided between said extremity ( 13 b ) of the projection ( 12 b ) and said second part ( 14 b ), having a diameter which is larger than the diameter of said second part ( 14 b ) and smaller than the diameter of the extremity ( 13 b ) of the second projection ( 12 b ).
At the bottom, the fastening clip ( 1 ) is provided with at least one springy element ( 15 ). In this embodiment, two springy lips ( 15 a , 15 b ) are provided which push the fastening clip ( 1 ) against the retaining plate ( 20 ). In this manner, the fastening clip ( 1 ), once it has been positioned on the retaining plate ( 20 ), is held in position by the pushing force of the springy element ( 15 ) opposite the fastening clip ( 1 ). In this manner the springy element ( 15 ) exercises a pushing force on the fastening clip ( 1 ) in a direction, which is opposite to the tractive force exercised on the fastening clip ( 1 ) by the fixed part ( 6 ) of the lower tackle cords ( 2 ).
The first opening ( 21 a ) and the second opening ( 21 b ) in the retaining plate ( 20 ) are chosen such that the fastening clip cannot be loosened without exercising a vertically downward force on the fastening clip ( 1 ) opposite the springy lips ( 15 a , 15 b ) directed downwards. The first opening ( 21 a ) is located on the side of the retaining plate ( 20 ) and is open on this side. This first opening ( 21 a ) has a diameter, which is smaller than the diameter of the extremity ( 13 a ) of the first projection ( 12 a ). The opening ( 21 a ) has a diameter, which is larger than or fitting for the diameter of the second part ( 14 a ).
The second opening ( 21 b ) consists of two partial openings, namely a first ( 22 a ) and a second partial opening ( 22 b ), the first partial opening ( 22 a ) having a diameter which is larger than the largest diameter of the second projection ( 12 b ), more particularly, larger than the diameter of the extremity ( 13 b ) of this second projection ( 12 b ). The second partial opening ( 22 b ) has a diameter, which is larger than the diameter of the second part ( 14 b ) of this second projection ( 12 b ) and larger than or fitting for the diameter of the third part ( 17 b ) of the second projection ( 12 b ). Preferably, the two partial openings ( 22 a , 22 b ) are circular, the opening angle between the two circles being smaller than 180°. It must be possible to shift the second part ( 14 b ) through the opening angle, while it should be impossible to shift said third part ( 17 b ) of the second projection ( 12 b ) through the opening angle, because of which the fastening clip ( 1 ) cannot been detached without exerting a vertically downward directed force on the device against the force exercised by the springy element ( 15 ) on the fastening clip ( 1 ).
Therefore the fastening clip ( 1 ) is brought into the retaining plate as follows:
the second projection ( 12 b ) is inserted into the first partial opening ( 22 a ), and the first projection ( 12 a ) is brought opposite the first opening ( 21 a );
the fastening clip ( 1 ) is pushed vertically downwards, such that the springy lips ( 15 a , 15 b ) are compressed. Now the projections ( 12 a , 12 b ), together with the parts ( 14 a , 14 b ) with the smallest diameter, are situated opposite the openings ( 21 a , 21 b );
the fastening clip ( 1 ) is now shifted into the openings ( 21 a , 21 b ), by a horizontal movement;
the fastening clip ( 1 ) is making a vertically upward movement, because the springy lips ( 15 a , 15 b ) are partly springing back, because of which the third part ( 17 a ) of the second projection ( 12 b ) becomes fixed, fitting into the second opening ( 21 b ) or at least cannot be shifted through the opening angle between the two partial openings ( 22 a , 22 b ) of the second opening ( 21 b ) in the retaining plate ( 20 ) and the fastening clip ( 1 ) is fixed opposite the retaining plate ( 20 ).
Applying one or several fastening clips ( 1 ) occurs by a combination of horizontal and vertical movements, the horizontal movement near the retaining plate ( 20 ) being shorter than 10 mm, allowing the Jacquard machine to be kept compact.
Providing such an embodiment for installing a fastening clip ( 1 ) in the retaining plate ( 20 ) has the advantage that by lateral forces alone the fastening clip ( 1 ) cannot come loose because the second partial opening ( 22 b ) of the second opening ( 21 b ) in the retaining plate ( 20 ) has a diameter which is larger than the diameter of the third part ( 17 b ) of the second projection ( 12 b ). Only by pushing down the fastening clip ( 1 ), so that the part ( 14 b ) situated higher up, with the smaller diameter, positions itself opposite the retaining plate ( 20 ) the opening angle between the two partial openings ( 22 a , 22 b ) is sufficiently large to remove the fastening clip ( 1 ) from the retaining plate ( 20 ).
On both sides, the fastening clip ( 1 ) has a recess ( 16 a , 16 b ) in its lateral face, having the form of a corresponding tool ( 30 ) (as shown in FIG. 3 ) in order to install or to remove one or several fastening clips ( 1 ). At least one of the recesses ( 16 a , 16 b ) is provided with a bulge ( 31 ) which fits into an opening ( 32 ) of the tool ( 30 ), the bulge ( 31 ) and the opening ( 32 ) being provided in such a manner, that when shifting the tool ( 32 ) onto the fastening clip ( 1 ), the tool ( 32 ) slides over the bulge ( 31 ) in a springy manner, until the opening ( 32 ) in the tool encloses the bulge ( 31 ) of the fastening clip ( 1 ). In this manner, detaching the fastening clip ( 1 ) from the retaining plate ( 20 ) may only occur by the reactive forces coming into being when the fastening clip ( 1 ) is maintained in the retaining plate ( 20 ).
The retaining plate ( 20 ) is designed for installing several fastening clips ( 1 ). To that effect, several first ( 21 a ) and second openings ( 21 b ) have been provided in a row in the retaining plate ( 20 ). The distance between the first openings ( 21 a ) or the second openings ( 21 b ) determines the pitch corresponding with the pitch of the hooks of the Jacquard machine. Therefore, the fastening clips ( 1 ) will not be shifted with respect to one another under the influence of vibrations and no tackle cords will be pulled out of position in a slanting position towards the hooks.
By means of a suitable tool ( 32 ) several fastening clips ( 1 ) may be installed or removed simultaneously, because of which this operation is suitable for automation.
In order to install the fastening clips ( 1 ) easily on the retaining plate ( 20 ), the retaining plate ( 20 ) has been strengthened by plate material or by solid material. In the Jacquard machine, these retaining plates ( 20 ) may be attached to a grid, which may be fixed, adjustable or movable.
With a similar embodiment of a fastening clip ( 1 ), as described above, the fastening clips ( 1 ) are accessible to such an extent, that the tackle cord height may be restricted, while the operator has a sufficiently good access to locate or to replace tackle cords. This will enable the height required for mounting a complete installation to be reduced and make it more compact.
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The invention on the one hand relates to a device for attaching and guiding of at least one tackle cord ( 2 ) in a Jacquard machine, the device ( 1 ) being designed for being attached to a part ( 20 ) of the Jacquard machine and being designed for being connected to at least one tackle cord ( 2 ), the device ( 1 ) being provided with a springy element ( 15 ) exercising a pushing force on the device ( 1 ) in a direction which is opposite to the tractive force exercised on the device ( 1 ) by the tackle cord ( 2 ). The invention further relates to a Jacquard machine, which is provided with a fixed, adjustable or movable grid and a number of retaining plates, which are attached to the grid and which are provided for attaching a number of devices according to anyone of the above-mentioned claims.
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CROSS REFERENCES TO RELATED APPLICATIONS
This application claims benefit of Provisional Appn 60/031,951 filed Nov. 27, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the attenuation and reduction of machinery and gas flow noise and turbulence in duct systems including, but not restricted to, heating, ventilating and air conditioning air duct systems.
2. Background Information
Conventional sound attenuators used in duct systems use resistance provided by filler material when sound travels through pores of the filler material. Typically FIBERGLASS, ROCKWOOL, foam and other fibrous materials are used for this purpose. Perforated sheets are used to increase the access of the sound from flow passage to filler material. The filler material that is used to attenuate sound creates some new problems. At higher gas flow velocities the filler material gets eroded into small particles and gets entrained in airflow contaminating indoor air of a facility. The filler materials produce some toxic gases, cause microorganisms to grow or release some hazardous products when they come in contact with some other chemicals. These problems make the use of filler material in sound attenuators dangerous. Pat. No. 4,287,962 Packless Silencer, Ingard et al, Sep. 8, 1981 addresses the above mentioned problems associated with the filler material of fibrous nature. Ingard et al uses sound attenuators with acoustic resistance provided by resistive sheets or perforated face sheets. While sound attenuators having perforated sheets were an improvement, they did not include benefits that round and oval passages inherently have over flat sheets or rectangular shapes. The entrance and exit were not designed optimally and this causes flow noise to increase and often results in turbulence of flow. Turbulent flow increases the energy required to maintain gas flow. These disadvantages led to a less than optimal acoustical and flow performance. As will be seen in the subsequent description, the present invention overcomes these disadvantages of the prior art.
SUMMARY OF THE INVENTION
The present invention is a media free sound attenuator that reduces machinery and gas flow noise and turbulence in duct systems. The present invention uses acoustic impedance of perforated passages and cavities, shape factors of the round/flat-oval passage elements and transitions to effectively reduce machinery and gas flow noise and turbulence in duct systems instead of using fibrous filler material. The present invention includes a metallic shell and at least one perforated liner element that acts like a flow passage. For optimum performance, the liner element is a spriral element. The shell and the liner elements are separated by divider plates, transitions are placed at the entrance and exit of the media free sound attenuator to reduce pressure drop and increase acoustic performance. The expansion chamber is an area discontinuity inside the sound attenuator that adds to the attenuation by reflecting the noise in the lower frequencies. The shape factor of the round and flat-oval passage elements adds to broad band noise attenuation, also the transitions at the entrance and exit are also effective in noise attenuation. All these factors enhance the performance of the sound attenuator in terms of insertion-loss, pressure drop and gas flow generates noise. Also, the improvements included in the present invention reduces turbulence of flow, which reduces horsepower required to maintain then flow. The present invention includes an optional expansion chamber that adds to the acoustic impedance of the sound attenuator.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, closely related figures have the same number but different alphabetical surfaces.
FIGS. 1, 1 A, 2 , 3 , 4 , 4 A, and 4 B show Isometric, Plan, Elevation and Side views of an attenuator with two ovoidal form passages with an expansion chamber.
FIGS. 5. 5A, 6 , 7 , 8 , 8 A, and 8 B show Isometric, Plan, Elevation and Side views of the attenuator with two ovoidal form passages.
FIGS. 9, 9 A, 10 , 11 , 12 , 12 A, and 12 B show Isometric, Plan, Elevation and Side views of the attenuator with a single ovoidal form passage with an expansion chamber in it.
FIGS. 13, 13 A, 14 , 15 , 16 , 16 A, and 16 B show Isometric, Plan, Elevation and Side views of the attenuator with the single ovoidal form passage.
FIGS. 17, 17 A, 18 , 19 , 20 , 20 A, and 20 B show Isometric, Plan, Elevation and Side views of the attenuator with the single round passage with an expansion chamber.
FIGS. 21, 21 A, 22 . 23 . 24 , 24 A, and 24 B show Isometric, Plan, Elevation and Side views of the attenuator with a single round passage.
FIGS. 25, 25 A, 26 , and 27 show Isometric, Elevation, and Plan views of a round attenuator with an annular passage with a bullet inside the attenuator.
FIGS. 28, 29 , and 30 show Isometric, Elevation and Plan views of the round attenuator with a round passage without a bullet inside the attenuator.
FIGS. 31, 31 A, 32 , 33 , 34 , 34 A, and 34 B show Isomatric, Plan, Elevation, and Side views of an attenuator with a single no-line-of-sight ovoidal form passage.
FIGS. 35, 35 A, 36 , 37 , 38 , 38 A, and 38 B show Isometric, Plan, Elevation and Side views of an attenuator with three ovoidal form passages.
FIGS. 39, 39 A, 40 , 41 , 42 , 42 A, and 42 B show Isometric, Plan, Elevation, and Side views of an attenuator with two ovoidal form passages converging to a single ovoidal form passage inside the attenuator, thus providing a gas flow passage that has two passages in the beginning which change into one.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention, a fibrous filler material free sound attenuator 101 is illustrated in FIGS. 1, 1 A, 2 , 3 , 4 , 4 A, and 4 B. FIGS. 1, 1 A, 4 A, and 4 B are isometric views. FIG. 2 is a top view. FIG. 3 is an elevation view. FIG. 4 is a side view. The fibrous filler material free sound attenuator 101 has an outer shell box 9 . The outer shell box 9 has entrance transition 5 that directs gas flow from an existing prior art rectangular or square duct (not shown), such as is common to the trade, through two ovoidal form passages 3 of the fibrous filler material free sound attenuator 101 , provided by the ovoidal form perforated spiral sheet 27 . An arrow indicates the direction of gas flow. The shape of the ovoidal form passages 3 adds to broad band noise attenuation. There is a region between the outer shell box 9 and the ovoidal form passages 3 that is divided into cavities using divider plates 7 . The divider plates 7 form cavities containing gas that has seeped through the ovoidal form perforated spiral sheet 27 from the gas flow through the fibrous filler material free sound attenuator 101 . The effect of the perforated spiral sheet 27 permitting gas to seep into these cavities results in sound attenuation. A gap in the ovoidal form passage 3 , serves as an expansion chamber 25 inside the outer shell box 9 . The expansion chamber 25 is an area discontinuity that adds to the sound attenuation by reflecting the noise in the lower frequencies. An exit transition 1 is provided at the other end of the fibrous filler material free sound attenuator 101 for connection to an existing prior art rectangular or square duct (not shown) such as is common to the trade. In the preferred embodiment of the present invention, the ovoidal form passages 3 are provided by the ovoidal form perforated sprial sheet 27 . A ovoidal form perforated sheet results in some sound attenuation but the ovoidal form perforated spiral sheet 27 works better.
In FIGS. 5. 5A, 6 , 7 , 8 , 8 A, and 8 B an alternate fibrous filler material free sound attenuator 103 without an expansion chamber 25 is illustrated. It includes the same parts as the fibrous filler material free sound attenuator 101 except there is no expansion chamber 25 .
In FIGS. 9, 9 A, 10 , 11 , 12 , 12 A, and 12 B a second alternate fibrous filler material free sound attenuator 105 with the expansion chamber 25 and a single ovoidal form passage 3 is illustrated. As can be seen from the FIG. 9, the ovoidal form passage has a share that essentially has two parallel sides with rounded ends. It includes a single entrance transition 39 , the ovoidal form passage 3 , the ovoidal form perforated sheet 27 , the outer shell box 9 , divider plates 7 , and a single exit transition 37 .
In FIGS. 13, 13 A, 14 , 15 , 16 , 16 A, and 16 B, a third alternate fibrous filler material free sound attenuator 107 without the expansion chamber 25 and having one ovoidal form passage 3 is illustrated. It includes an entrance transition 39 , the ovoidal form passage 3 , the ovoidal form perforated spiral sheet 27 , the outer shell box 9 , divider plates 7 , and a single exit transition 37 .
In FIGS. 17, 17 A, 18 , 19 , 20 , 20 A, and 20 B, a fibrous filler material free sound attenuator 109 with the expansion chamber 25 and having one round passage 36 is illustrated. It includes a round entrance transition 35 , the round passage 36 , the round perforated spiral sheet 28 , the outer shell box 9 , divider plates 7 , and a round exit transition 33
In FIGS. 21, 21 A, 22 , 23 , 24 , 24 A, and 24 B, a fourth alternate fibrous filler material free sound attenuator 111 without the expansion chamber 25 and having one round passage 36 is illustrated. It includes the round entrance transition 35 , one round passage 36 , the round perforated spiral sheet 28 , the outer box shell 9 , divider plates 7 , and the round exit transition 33 .
In FIGS. 25, 25 A, 26 , and 27 , a round fibrous filler material free sound attenuator 113 with a round spiral outer shell 15 and an annular perforated passage spiral duct 17 is illustrated. There is a perforated bullet 21 in the center of the attenuator 113 with z-trims 19 attaching it within the annular perforated passage spiral duct 17 . The bullet 21 has solid nose cones 29 on both ends. The perforated bullet 21 further reduces machinery and gas flow noise in this embodiment of the present invention.
In FIGS. 28, 29 , and 32 , an alternate round fibrous filler material free sound attenuator 115 with a round spiral outer shell 15 and an annular perforated passage spiral duct 17 is illustrated.
FIGS. 31, 31 A, 32 , 33 , 34 , 34 A, and 34 B depict a rectangular fibrous filler material free sound attenuator 117 without a line of sight. The attenuator 117 has a ovoidal form passage 3 that has a bend 31 inside the attenuator 117 in such a way that the other end of the attenuator 117 can not be seen from one end of the attenuator 117 . The attenuator 117 has the outer shell box 9 , an offset entrance transition 43 , the nvoidal form passage 3 , a ovoidal form perforated spiral sheet 27 , and an offset exit transition 41 .
In FIGS. 35, 35 A, 36 , 37 , 38 , 38 A, and 38 B, a fifth alternate fibrous filler material free sound attenuator 119 having three ovoidal form passages 3 is illustrated. It differs from the alternate fibrous filler material free sound attenuator 103 illustrated in FIGS. 5 to 8 in that there are three ovoidal form passages 3 .
In FIGS. 39, 39 A, 40 , 41 , 42 , 42 A, and 42 B, a rectangular fibrous filler material free sound attenuator 121 with two ovoidal form passages 3 A at the entrance and converying to a single ovoidal form passage 3 B is illustrated. It includes the entrance transition 1 , an ovoidal form exit transition 47 , a transition 23 that changes from the two passages 3 A to single passage 3 B, divider plates 7 , the outer shell box 9 , and the ovoidal form perforated spiral sheet 27 . This embodiment of the present invention further reduces machinery and gas flow noise.
Ovoidal form passages 3 , 3 A, and 3 B such as are shown in various figures such as FIGS. 10 and 40, as well as the annular perforated passage duct 17 as shown in FIG. 25 are a significant advance in reducing machinery and gas flow noise in duct systems. Aside from sound attenuation, there is also a reduction in flow turbulence. The transitions enumerated in this description, such as the entrance transition 5 and the exit transition 1 as shown in FIGS. 4A and 4B, reduce turbulence of flow by providing a transition from a rectangular duct leading into the present invention to the ovoidal form or round shape of the passage or duct. This reduction in turbulence not only reduces noise, it also reduces pressure drop from flow through various attenuators described in this specification. Reducing pressure drop means less horsepower is required to maintain a given flow of gas, such as air, throuh a a duct system. So, incorporating the present invention in a duct system not only reduces noise, it also saves energy.
Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. For example, gas flow is mentioned, but as obvious to anyone skilled in the state of the art, this invention applies to air, which is a mixture of gases. Also, while the preferred embodiment of the present invention incorporates perforated spiral sheets to form passageways, flat sheet will produce some sound attenuation, but not as much as the spiral sheets.
Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.
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A sheet metal media free sound attenuator reduces noise from machinery and gas flow in duct systems, that has a solid outer shell box and at least one flow passage made of perforated sheet. The flow passage can have a gap called expansion chamber and supports that divide cavity between a wall of the perforated passage and a wall of the outer shell box. Entrance transition and exit transition of the sound attenuator provides smooth flow into the attenuator, reduces pressure drop, and increases attenuation. In the preferred embodiment, the perforated sheet is a perforated spiral sheet.
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BACKGROUND OF THE INVENTION
The invention relates to a method of producing, on a circular knitting machine having a rotatable needle cylinder, knit fabrics having combed-in fibers and a preselected fiber density, the method comprising the steps of delivering an amount of fibers synchronous with the needle cylinder rotary speed to a teasing cylinder rotating at high speed, yielding fibers from said teasing cylinder to a comb-in zone and transfering fibers in the comb-in zone to the needles without the needles contacting the teasing cylinder. The invention further relates to a knitting machine on which this method can be carried out.
In methods and circular knitting machines of this kind (U.S. Pat. Nos. 4,458,506 and 4,546,622 the fibers, in contrast to conventional methods and circular knitting machines U.S. Pat. No. 3,709,002 are combed contactlessly into the needle hooks, the term "contactlessly" meaning that the needle hooks do not pass through teasing hooks. The transfer of the fibers to the comb-in zone is performed as in circular knitting machines with conventional combs under conditions synchronous with the rotation of the needle cylinder. The term, "synchronous conditions", is to be understood to mean that, at any constant rotatory speed of the needle cylinder, the fibers are always delivered to the comb-in zone at a preselected, constant amount of fibers per unit time, so as to produce goods having a preselected, constant fiber density. On the other hand, the amount of fiber fed to the comb-in zone changes synchronously in the case of changes in the needle cylinder rotatory speed, in order that, in the event of reductions or increases in the needle cylinder rotatory speed, correspondingly less or more fibers will be delivered to the comb-in zone, thereby assuring that the preselected fiber density will be achieved at any rotatory speed of the needle cylinder, i.e., especially during the execution of start and stop cycles. If the feed of fiber to the teasing cylinder by means of feed rolls, for example, "synchronous conditions" means that the feed rolls and the needle cylinder are driven from a single, main drive through gears, belts, rollers or the like, so that the ratio of their rotatory speeds is the same at all rotatory speeds of the needle cylinder, and that, independently thereof, the teasing cylinder is driven always at the same high rotatory speed at all needle cylinder speeds.
Experiments on such circular knitting machines with contactless fiber feed have surprisingly shown that, during those phases in which the needle cylinder is subjected to abrupt changes of rotatory speed, such as is the case especially during the start and stop cycles and during "tip" operation, undesirable deviations from the preselected fiber density can result, which lead to thick and thin areas in the finished knit goods.
"Thick and thin areas" in this connection refers to those points in the finished goods at which the fiber density is lower or higher than the preselected fiber density. The length of the thick and thin areas appears to be dependent upon a number of factors, such as the length of time for which the needle cylinder is stopped, the duration of the braking or accelerating cycles of the needle cylinder until it reaches a full stop or the production speed, the fiber length, or the titer of the fibers.
The invention is addressed to the problem of improving the method and the circular knitting machine of the kind defined such that thick and thin areas will be largely avoided. In particular, those thick and thin areas are to be avoided such as can develop upon the abrupt braking of the needle cylinder to a stop, e.g., due to thread breakage or the like, or upon the acceleration of the needle cylinder from a full stop until it reaches the production speed.
The method of this invention is characterized by substantially maintaining constant the preselected fiber density also when abrupt changes of the rotary speed of the needle cylinder occur by at least momentarily feeding amounts of fibers which differ from the synchronous amount of fibers to the comb-in zone. A circular knitting machine for the production of knit goods with combed-in fibers comprises according to this invention a rotatable needle bearing needle cylinder, a card which has a means for feeding the fibers, a comb-in zone through which the needles pass for the purpose of contactless fiber pickup, and a teasing cylinder rotating at high speed which takes the fibers from the feed means and gives them to the comb-in zone, and a drive means for the synchronous driving of the needle cylinder and feed means. The card has a controller which becomes active upon abrupt changes in the rotary speed of the needle cylinder for the synchronous changing of the amount of fibers yielded to the comb-in zone.
The invention brings with it the surprising advantage that a great number of thick and thin areas can be prevented by the simple measure of feeding fewer fibers upon the abrupt braking of the needle cylinder, but more fibers upon the acceleration of the needle cylinder from a full stop, than would correspond to the synchronous amounts of fibers.
Additional advantageous features of the invention will be found in the subordinate claims.
The invention will now be further explained in conjunction with the appended drawing of a preferred embodiment.
SUMMARY DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic longitudinal cross section taken through a circular knitting machine according to the invention,
FIGS. 2 and 3 are longitudinal sections taken through the area surrounding the comb-in zone of the knitting machine of FIG. 1, on an enlarged scale and in two different positions,
FIG. 4 is a perspective diagrammatic representation on a larger scale of the area surrounding the comb-in zone of the circular knitting machine of FIG. 1, and
FIG. 5 is the block circuit diagram of a control system for the circular knitting machine of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, and in U.S. Pat. Nos. 4,458,506 and 4,546,622, a circular knitting machine for the production of high-pile knit goods 1 contains a rotatable needle cylinder 2 in which vertically displaceable knitting needles 3 with hooks 4 are mounted, which are moved up and down in the area of at least one knitting system by means of stationary cam parts 5a and 5b, for the purpose of producing a base knit fabric from the yarns that are not shown. The fibers are loosened up and combed into the knit fabric by means of at least one comb or carding unit 6, which consists, for example, of a feed system consisting, for example, of two feed cylinders 7a and 7b for feeding a condensed sliver or fiber band 8, a teasing or separating cylinder 10 intended to break up the fiber band 8 into individual fibers 9, and a comb-in zone 11 through which the knitting needles 3 and their hooks 4 pass in order to pick up the fibers 9.
The teasing cylinder 10, which can rotate in the direction of an arrow P, is covered on its circumference with a clothing 13 bearing outwardly projecting hooks 14. The teasing cylinder 10 is driven at a substantially greater circumferential speed than the feed cylinders 7, and therefore pulls the fiber band 8 apart in single fibers 9.
To prevent the fibers picked up by the teasing hooks 14 from being flung back out of the hooks, despite the great effective centrifugal forces acting on them due to the high speed of the loosening cylinder 10, the comb 6 has a shroud 15, which is preferably a part of a fully enclosed casing 20 surrounding the teasing cylinder 10 and the comb-in zone 11, and is situated opposite the outer circumference of the teasing cylinder 10, and contains an entry 16 for the fiber band 8 fed by the feed cylinders 7 and an exit opening 17 through which the fibers 9 can be fed into the comb-in zone 11. The shroud 15 then defines the outside of a teasing and accelerating section 18 beginning directly at the entry opening 16 and indicated by an arrow, within which the shroud 15 is at a small, but otherwise constant distance of, for example, less than one millimeter, from the tops of the teasing hooks 14 of the teasing cylinder 10, so that the fibers cannot come off the teasing hooks 14. The teasing and accelerating section 18 is then followed, in the direction of rotation of the teasing cylinder, by a teasing or detachment section or zone 19 indicated by an arrow, which ends at the exit opening 17 and is at a distance from the tips of the teasing hooks 14 which gradually increases in the direction of rotation to a value of, for example, several millimeters. Therefore, the fibers 9 can be loosened in this section 19 by the centrifugal force, entrained tangentially in the air stream produced by rotation of the teasing cylinder, and combed into the knitting needles lifted by the cam parts 5 in the comb-in zone, without coming in contact with the teasing hooks 14.
With the teasing cylinder 10 there is associated a drive independent of the conventional needle cylinder drive, in the form of a motor 33 which drives the teasing cylinder 10 at a speed that is constant at all knitting machine speeds, or can be adapted to a certain extent to the momentary knitting machine speeds and/or the properties of the fibers involved. The motor 33 can be a reversible-pole motor having at least two rotatory speeds.
In known circular knitting machines of this kind (U.S. Pat. Nos. 4,458,506 and 4,546,622), the feed cylinders 7 are driven synchronously with the needle cylinder rotatory speed. According to the invention, however, a drive 34 is provided--a motor for example--which is connected on the one hand by a gear 35 to the crown gear of the needle cylinder 2, and on the other hand by additional gears 36, a shaft 37 and a belt drive 38 to one input of a differential gearing 39. Another input of this differential gearing 39 is connected by another belt drive 40 to the output shaft of a servo motor 41. On the output shaft of the differential gearing 39 there is fastened a belt pulley 42 which is connected by a belt 43 to another belt pulley 44 on whose shaft there is fastened a worm 45. This worm is engaged in the usual manner with a worm gear which is mounted on one of the shafts of the feed cylinder 7 and serves to drive the latter. On the basis of the drive just described, it is possible to drive the feed cylinders 7 either synchronously with the needle cylinder if the servomotor 41 is stopped, or, if motor 34 is stopped, synchronously with the rotatory speed of the servomotor 41, or, if both motors 34 and 41 are running, the feed cylinders can be driven at a resultant speed. If the servo motor 41 is a reversible motor, the feed cylinders can be driven either at a greater or at a lower rotatory speed than the momentary rotatory speed that can be produced through the gears 35, 36 and 38 and is synchronous with the needle cylinder speed, since the differential gearing will add or subtract the two input speeds depending on the direction of rotation of the servo motor 41. The differential gearing thus constitutes a means for the interruption and restoration of synchronism between the feed means and the needle cylinder.
According to FIGS. 2 and 3, the casing 20 has in the area adjacent the needle backs a fixed fiber guiding plate 47 whose end at the comb-in zone 11 is of streamlined shape. The fiber guiding plate 47 is disposed such that, in back of the needles 3, and between it and an imaginary cylindrical surface 47 in which the tips of the teasing hooks 14 move, a wedge-shaped gap 49 is formed (U.S. Pat. No. 4,546,002). Furthermore, in back of the fiber guiding plate 47, in the direction of rotation of the teasing cylinder 10, there is provided an ejection flap 50 which is articulated on a pivot pin 51 on the fiber guiding plate 47 and is preferably a part of the latter. The other end of the ejection flap 50 adjoins, along a sloping junction, a fixed casing part 52, the components 47, 50 and 52 extending preferably at least over the width of the teasing cylinder. The ejection flap 50 has a lug 53 which is joined to an actuator 55 which consists, for example, of a solenoid coil with a plunger 54 which can be extended and retracted and is linked to the lug 53. This actuator 55 is disposed laterally beside the teasing cylinder 10 and is pivoted on a pivot pin 56 on a stationary machine part. In the disengaged position, e.g., when the plunger 54 is retracted, the fiber guiding plate 47 and the closed ejection flap 50 form a substantially continuous fiber guiding surface (FIG. 2) which prevents fibers from being thrown off the teasing hooks 14 and produces a combing out and orientation of the fiber tufts which have already been laid into the needles but are still in the comb-in zone 11. If, however, the plunger 54 is pushed out of the solenoid 55 by means of an electrical signal, the rear end of the ejection flap 50 is rocked in the manner shown in FIG. 3 radially away from the teasing cylinder 10 to the working position. This results in the formation of an ejection opening 58 virtually tangential to the circumference of the teasing cylinder 10, and any fibers that are still on the teasing hooks 14 are released by the centrifugal forces and then are, for example, aspirated by a central aspirating system.
Preferably ahead of the needles 3, in the direction of rotation of the teasing cylinder 10, there is disposed in accordance with the invention a blocking means 60 for blocking the needle hooks 4 that are in the comb-in zone 11. This blocking means 60 serves to block off the open needle hooks 4 if necessary, so that they will not pick up any more fibers. In accordance with FIGS. 1 to 3, the blocking means 60 is a thin, e.g., 0.15 mm thick, plate extending preferably at least over the width of the teasing cylinder 10 and guided displaceably in a slotted guide 61 which is provided in a wall portion 62 (FIGS. 2 to 4) surrounding the teasing cylinder. The slotted guide 61 runs from one exit end 63 of the wall portion 62 situated ahead of the comb-in zone in the teasing cylinder's direction of rotation, substantially tangentially to the teasing cylinder 10, and toward a gap 64, which is defined on the one hand by the upper ends of the needle hooks 4 raised to receive fibers, and on the other hand by the cylindrical surface 48, and whose width is slightly greater than the thickness of the blocking means 60. The end of the blocking means 60 protruding from the exit end 63 is linked to one end of a rocking arm 65 which is pivoted in its central portion at 66 and is linked at its other end to an actuator 68 which consists, for example, of a solenoid having a plunger 67 linked to the rocking arm 65, and is pivotally mounted on a fixed part 69 of the machine. By feeding an operating signal to the actuator 68, the blocking means 60 can therefore be moved either to the disengaged position shown in FIG. 2 in which it releases the gap 64 and is withdrawn far into the slotted guides 61, or it can be moved to its working position as shown in FIG. 3. In this working position, the end of the blocking means 60 associated with the needles extends both through the slot 64 and also through the wedge-shaped gap 49 that follows in the direction of rotation of the teasing cylinder. Due to the fact that the blocking means 60 extends through the slot 64, the open needle hooks 4 are blocked such that, ahead of the comb-in zone 11, fibers released from the card teasing hooks 14 are not combed into the needle hooks 4. Since the blocking plate extends into the wedge-shaped gap 49, however, the fiber tufts 57 combed into the needle hooks are protected against the teasing hooks 14 regardless of the fiber length selected in the individual case, and therefore they cannot be attacked by the teasing hooks and pulled out of the needle hooks. The blocking means 60 is thus a component of a protective means for preserving the fiber tufts 57 combed into the needles 3 situated in the comb-in zone. At the same time the section covering the needle hooks and the section covering the fiber tufts 57, of the blocking means 60, could also be separated from one another and connected to different actuating means. Also, the rocking arm 65 is shown much shorter than it would be, and actually it is about as long as is necessary to achieve the desired length of movement of the blocking element 60.
FIG. 5 shows a control apparatus for the circular knitting machine described in conjunction with FIGS. 1 to 4. It contains a power supply 71 which provides current to all electronic and electromagnetic components, especially a controller 72 for the servo motor 41 and a controller 73 for the drive 34 of the circular knitting machine, and is also connected to a main switch 74. The controller 72 for the servo motor has an input connected to the power supply 71 and an output connected to the servo motor. Another input is connected to a starter switch 75, a switch 76 being inserted into the line running to the latter, which can be brought by an actuator 77 from its normal, closed position to an open position. Another input of the controller 72 is connected to two switches 78 and 79 which are in series. Switch 78 can be brought by an actuator 80 from its normal, closed position to an open position, while switch 79 can be brought by an actuator 81 from its normal, open position to a closed position. An additional input of the controller 72 is connected to the moving contact of a switch 82 which can be turned to any of three solid contacts which are connected each with a potentiometer 83. The other terminals of this potentiometer 83 are connected to three fixed contacts of an additional switch 84, which also has a contact that can be moved to one of the three fixed contacts. The switches 82 and 84 and the potentiometer 83 form a preselection circuit and serve to provide the controller 72 with, for example, three individually selectable rotatory speeds for the rotation of the servo motor 41 in the forward direction. Another input of the controller 72 is finally connected by a line 85 to the moving contact 86 of a switch whose three fixed contacts are connected by potentiometer 87 to three fixed contacts of a switch 88 such that, with the switches 86 and 88 and the potentiometers 87, three individually presettable rotatory speeds, for example, can be selected for the servo motor 41 when it runs in the reverse direction.
The starter switch 75 is connected by an adjustable timer 89 to the fixed contact of a switch 90. The moving contact of this switch 90 is connected to the controller 73 for the motor 34 of the needle cylinder. This motor 34 has an indicator in the form of a tachometer generator 91 which, in the usual manner, consists of a dynamo which provides at its output a voltage which is proportional to the rotatory speed of the motor 34. The output of a reference standard 92 is connected to an additional input of the controller 73. The reference standard 92 contains an ordinary amplifier 93 to whose one input a potentiometer 94 is connected and whose output is connected to the moving contact of a switch 95 whose two fixed contacts are connected each through a resistance 96-97 to the input of an additional amplifier 98. The output of the tachometer generator 91 is connected to the input of a comparator 100 to whose output is connected an actuator 101 which serves to shift the moving contact of switch 95 from the one to the other fixed contact of this switch.
The controller furthermore contains a manually operated stop switch 102 and, if necessary, at least one automatically operating stop switch 103, for example in the form of a shutoff commonly used in circular knitting machines, which is tripped in the event of thread breakage, needle breakage or the like. The two switches 102 and 103 are connected to an actuator 104 which serves to shift the normally closed switch 90 to an open position. The actuator 81 is connected to the output of a comparator 105 whose input is connected to the output of the tachometer generator 91. Otherwise, the free terminals of switches 75, 84, 88, and 102 and 103 of the potentiometer 94 are connected to the power supply or to some other appropriate source of current or voltage.
Lastly, the controller of FIG. 5 has two additional comparators 106 and 107. The output of comparator 106 is connected on the one hand to one input of each of the actuators 55 and 68 and on the other hand to the actuator 77 of switch 76, while the comparator 107 is connected on the one hand with an additional input of each of actuators 55 and 68 and on the other hand to the actuator 80 of switch 78. The inputs of the comparators 106 and 107 are connected to the output of the tachometer generator 91.
The switches 76, 78, 79, 90 and 95 and their associated actuators 77, 80, 81, 101 and 104 can consist of purely electronic components, but also they can be electromechanical components, e.g., reed contacts operated by relays.
In the control system described, the following adjustments are possible:
Depending on the type of fiber to be used, which can vary in regard to fiber length, titer or the like, first the ganged pairs of switches 82-84 and 86-88 can be set such that the servo motor 41, whether turning forward or backward, will run at a rotatory speed determined according to the type of fiber. The rotatory speeds required in each case are to be determined in preliminary tests with the fibers to be used, and if necessary can be recorded in tables. Experiments have shown that, in most practical cases, three different rotatory speeds forward and three in reverse will suffice, and that these speeds can be associated with fiber lengths up to 25 mm, between 25 and 40 mm, and 40 to 80 mm of length. This gives the advantage that the potentiometers 83 and 87 can be set one time, and, when the type of fiber changes, only switch pairs 82-84 and 86-88 will need to be changed. Furthermore, the timer 89 can be adjusted to the time desired in the particular case. The timer 89 determines how long a time the servo motor 41 is to be energized before turning on the motor 34 of the knitting machine. Here, again, the adjustment can be determined on the basis of the type of fiber and recorded in tables. It would also be possible to provide several fixed timers, each associated with one type of fiber. It is desirable, however, to adjust the timer to a sufficiently long period of time to permit a sufficiently long preliminary feed by the servo motor 41 for all of the types of fibers that are involved. An additional adjustment is offered by the potentiometer 94 which is associated with the reference standard 92. The reference standard 92 establishes through the controller 73 the accelerations with which the speed of the needle cylinder is to be increased during start-up, and on the other hand it establishes the maximum rotatory speed, i.e., the production speed which the needle cylinder is to reach. The production speed can be adjusted with the potentiometer 94. Lastly, it is possible to set the rotatory speed of the motor 33 driving the teasing cylinder 10, through an additional potentiometer not shown, or through a switch.
The control system described operates as follows:
By operating the main switch 74, first the motor 33 driving the teasing cylinder 10 and the power supply are turned on to supply power to the control system. By means of an interlock, which is not shown, provision can be made such that operation of the starter switch 75 will not be possible until the teasing cylinder has reached its nominal rotatory speed. The blocking means 60 and the ejection flap 50 are during this time in the working position represented in FIG. 3, while the needle cylinder 2 is stopped and the different switches assume the positions seen in FIG. 5. The result is that, in the area of the entrance opening 16, the teasing cylinder 10 teases out the part of the condensed sliver 8 that extends into the range of action of the teasing hooks 14. The fibers pulled out of the sliver in this manner are accelerated out of the teasing hooks 14 in the area of the releasing section 19, but, on account of the extended blocking means 60, are unable to enter into the needle hooks 4. Consequently, these fibers are transported on over the needlehooks and then ejected through the open ejection flap 50. At the same time, the blocking means 60 prevents fiber tufts 57, which have already been laid into the needle hooks in a preceding knitting action, from being pulled out of the needle hooks by the suction of the teasing cylinder 10 or by the interference of the teasing hooks. The fiber tufts 57 already laid in the needles that are in the comb-in zone therefore are retained, so that thick and thin areas are prevented when the needle cylinder starts up.
After the teasing cylinder 10 has reached its nominal speed, the starter switch 75 is closed, thereby delivering power through the closed switch 76 and the controller 72 to the servo motor 41 to make the latter run in the forward direction at a speed depending on the position of the switch pair 82-84 and the potentiometer 83. As a result, the feed rolls 7 are set in rotation and the portion of the fiber sliver partially torn apart by the teasing cylinder 10 is replaced at the entry 16. Thus, a higher rate of feed of fibers than the synchronous rate is fed to the comb-in zone 11, because in conventional high-pile knitting machines the feed cylinders are at rest as long as the needle cylinder is at rest. This process, which is known as forefeeding the fibers and is intended for the prevention of thin areas caused by start-up, likewise takes place when the needle cylinder is stopped, and lasts until the timer 89 emits a signal. When this signal appears, the sliver or sheet of fibers situated on the teasing cylinder 10 is again built up to the extent that is necessary for the knitting procedure that follows.
The signal from the timer 89 runs through the switch 90 and the controller 73 to start the motor 34 driving the needle cylinder, preferably with an initial, comparatively great start-up acceleration established by the reference standard 92. This start-up acceleration results when the moving contact of switch 95 is connected to the resistance 97 which, with the capacitor 99, forms an RC circuit and results in a voltage rise at the output of the amplifier 98 corresponding to the first section of the U/t curve represented in a block 108 of the reference standard 92. The needle cylinder thus begins to rotate, and the tachometer generator 91 delivers a voltage proportional to the momentary speed of the motor 34, which is fed to the comparators 106 and 100 which were activated in the start-up cycle. When this voltage attains a relatively low value detected by the comparator 106, the comparator 106 emits a signal which is delivered to the actuator 77 which then opens the switch 76 thus turning off the servo motor 41. At the same time the output signal from the comparator 106 is delivered to the actuators 55 and 68, thereby shifting the ejection flap 50 and the blocking means 60 to the disengaged position seen in FIG. 2. As a result of the shutting off of the servo motor 41, the feed cylinders 7 are then driven at a speed determined only by the motor 34, i.e., a speed synchronous with the needle cylinder speed. The displacement of the ejection flap 50 and of the blocking means 60, however, brings it about that the needle hooks 4 are now released and the ejection opening 58 is closed, so that all of the fibers fed by the teasing cylinder 10 are placed in the needles 3. The synchronous rotation of the feed cylinders 7 now assures that the necessary amount of fibers will be fed. The voltage at which the comparator 106 emits its signal is best selected such that, when the needle cylinder is started, the lowest possible number of needles will enter the comb-in zone before the blocking means 60 is withdrawn, so as to prevent failure of delivery of fibers to a plurality of adjacent needles. In practical use, the voltage of the tachometer generator 91 can be selected at such a low level that no more than one needle will pass through the comb-in zone without picking up fibers.
The rotatory speed of the needle cylinder now increases with the acceleration preset by the reference standard 92. It can happen that some thin areas will occur in the goods on start-up, which are apparently due to the fact that, if excessively great accelerations occur, the synchronous rotatory speed of the feed cylinders 7 is not sufficient. To prevent such thin areas a changeover to a lower acceleration rate will be made at a needle cylinder speed to be determined by experiment. This is accomplished as follows: when the voltage of the tachometer generator 91 reaches a certain level, corresponding for example to the voltage a in block 108, the comparator 100 will emit a signal and thus by means of actuator 101 will shift the moving contact of switch 95. Consequently, the needle cylinder will then be accelerated at a second, lower rate until it has reached its preset production speed and is maintained at this speed by the controller 73. The lower speed is established in this case by the RC circuit formed by the resistor 96 and the capacitor 99.
If the knitting machine is to be shut off, either the stop switch 102 or the stop switch 103 is operated automatically. When this happens, the comparators 105 and 107 which were inactive during the start cycle are activated and at the same time the two comparators 106 and 100 which were active during the start cycle are rendered inactive. Furthermore, a signal is delivered to the actuator 104 causing it to open the switch 90, thus shutting off the motor 34 and at the same time actuating a magnetic brake to stop the needle cylinder.
The needle cylinder is then braked according to the amount of braking power applied, while the teasing cylinder 10 continues to run at an unchanged speed so that fibers are fed into all needles running through the comb-in zone until the needle cylinder comes to a full stop. Since the feed cylinders 7 are also braked during the stop cycle, the wire hooks 14 in the teasing cylinder 10 now tear a higher percentage of fibers from the fiber sliver projecting into the entry opening 16 than is necessary for the attainment of a uniform knit fabric. The thickened areas thus caused are avoided in accordance with the invention in that, upon the attainment of a preselected needle cylinder speed, the feed cylinders are rotated more slowly than the synchronous speed in order thereby to compensate the oversupply of fibers produced by the teasing cylinder. To this end, the comparator 105 is set to a preselected voltage, so that, upon the attainment of this voltage at the output of the tachometer generator 91, it will emit a signal which will operate the actuator 81 to close switch 79 and thus turn on the servo motor 41, through line 85 and the controller 72, in the reverse direction at a speed predetermined by the setting of the switch pairs 86-88 and the potentiometer 87. Thus the rate of fiber feed in the area of the comb-in zone 11 is reduced to such a level that thick areas in the fabric caused by the shutoff cycle are prevented. The rotatory speed at which the servo motor 41 is to be turned on must be determined by experiment. It can also happen that the servo motor must be turned on when the switches 102 and 103 are actuated, in which case the comparator 105 is to be set to a value just below the production speed or it is to be turned on directly by the switches 102 and 103.
To avoid thick areas from forming in the start cycle, the comparator 107 puts out a signal shortly before the needle cylinder stops; this signal is delivered on the one hand to the actuators 55 and 68 and on the other hand it turns off the servo motor through the actuator 80 and the switch 78 which it opens, so that, when the needle cylinder comes to a stop, the feed cylinders will stop also. The feeding of the output signal to the actuators 55 and 68 has the result of shifting the ejection flap 50 and the blocking means 60 back to their working position shown in FIG. 3, and therefore fibers which might be fed by the still rotating teasing cylinder 10 while the needle cylinder is stopped are not introduced in the needles 3, which are also stopped, but are removed through the ejection opening 58. Thus no more fibers are introduced even into those needles 3 which enter the comb-in zone just before the needle cylinder stops than corresponds to the desired fiber density. At the same time the output voltage of the tachometer generator 91 at which the comparator 107 emits its signal can be selected so as to be so low that only one more needle enters the comb-in zone after the blocking means has been moved forward. Furthermore, provision is made through the output signal of the comparator 107 so that all switches will then reassume the positions shown in FIG. 5.
The invention is not limited to the described embodiment, which can be modified in many ways. For example, it is possible to provide, instead of the blocking means 60, a covering flap suspended pivotally from the side walls of the shroud 15 and bearing at its end adjacent the needles 3 a plate which, when the covering flap turns, is introduced into a gap 109 (FIG. 3) between the shroud 15 and the front sides of the needles for the purpose of blocking their open hooks 4. This covering flap could also be controlled by a solenoid actuator. Instead of the fiber guide plate 47 containing the pivoted ejection valve 50, a fiber guide plate consisting of one piece and displaceable radially and, if desired, also circumferentially of the teasing cylinder 10, can be provided, or a pivoting fiber guide plate simultaneously forming the ejection flap. Such a fiber guide plate would have the advantage that, between the blocking means 60 in its active position and the end of the fiber plate associated with it, a sufficiently wide air aspirating gap could be formed, which would improve the air flow needed for the ejection of fibers. Furthermore, it is possible to provide, instead of the solenoids 55 and 56, other actuating means, e.g., hydraulic or pneumatic cylinder-and-piston systems. The ejection flap 50 can be disposed at a point between the entry opening 16 and the comb-in zone 11 in the direction of rotation of the teasing cylinder 10, and it can be connected, if desired, to an aspirator. In this manner shut-down thickenings can be prevented without requiring a blocking means for the needles, because all of the fibers entering the hooks 14 of the teasing cylinder 10 while the needle cylinder is stopped would be removed through the ejection opening before reaching the comb-in zone 11. Furthermore, the pivoting ejection flap 50 can be replaced by a sliding fiber guide plate, which offers advantages especially with regard to access to the parts of the card situated in back of the needles. The over-proportional braking of the feed cylinders 7 performed by means of the servo motor 41 could also be accomplished by means of a remote-controlled clutch (U.S. Pat. No. 3,709,002) by temporarily disengaging this clutch during the stop cycles or withdrawing it pulse-wise, in order thereby to interrupt at least momentarily the synchronous running of the feeding cylinders.
As seen in FIG. 5, it is possible with a small number of different, preset speeds of the servo motor 41 to prevent any and all thick and thin areas. There is also the possibility of replacing the preselecting means formed by the switch pairs 82-84 and 86-88 and potentiometers 83 and 87, with programmed preselecting means which constantly change the speeds of the servo motors on the basis of a predetermined schedule, e.g., a curve, individually attuned to the type of fiber used in the individual case. Accordingly, all of the rest of the circuit elements can be adapted individually to the type of fiber. Provision can furthermore be made for momentarily interrupting the synchronism between the feed means and the needle cylinder, not only in the starting and stopping cycles, but also in the event of any other abrupt speed changes. A momentary interruption of the synchronism can also be brought about by varying the distance between the feed means, e.g., the two feed cylinders 7, and the teasing cylinder 10, or by varying the rotatory speed of the teasing cylinder 10, because the synchronism between the feeding of fibers to the teasing cylinder and the fiber transfer to the comb-in zone resulting in the required fiber density is also affected by these factors.
Those parts of the guard means which serve for the prevention of the disengagement of fiber tufts already held on the needles can also be modified. It is mentioned only by way of example that, to this end, a) the teasing cylinder could be stopped upon every stop and restart and then started up again or at least it could be braked down, b) the conditions of flow in back of the comb-in zone could be arranged such that the fiber tufts cannot come in contact with the tips of the teasing hooks 14 when the needle cylinder is stopped, c) the distance between the teasing cylinder and the needles and/or the fiber guide plate could be increased while the needle cylinder is stopped, d) teasing hooks could be used which, when the needle cylinder is stopped, are retracted into the teasing cylinder 10, and e) compressed air or a vacuum could be produced by using teasing cylinders or fiber guide surfaces having screen-like surfaces, in order to keep the fiber tufts away from the card hooks 14.
The above-described controller can accordingly also be used in creep rate operation or for so-called tip operation, in which the needle cylinder is turned each time only briefly by a few needle spaces. In order even here to assure the preselected fiber density it can be necessary to further reduce the speed of the teasing cylinder or the feed rate of the fibers to the teasing cylinder or to sustain the synchronism in the operation of braking down.
Instead of the feed means represented, feed means can be provided which have at least one feed cylinder and a fiber guide plate associated with it (U.S. Pat. No. 3,968,662).
The invention has just been described in conjunction with the example of a single knitting system of a circular knitting machine. In circular knitting machines with a plurality of system, the described card 6 can be associated with each system. At the same time it is possible to drive a plurality of teasing cylinders with a single motor. Also, the term circular knitting machines is to include circular hosiery machines.
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The invention concerns a process and a circular knitting machine for the production of knit goods with combed-in fibers, in which an amount of fibers synchronous with the needle cylinder rotatory speed is fed to a teasing cylinder rotating at high speed, transferred by the latter to the comb-in zone, and taken from the needles in the comb-in zone without contacting the teasing cylinder. To prevent the development of areas overfilled with fibers or short of fibers in the finished knit goods on account of the contact-less fiber feed, during or before abrupt reductions or increases in the rotatory speed of the needle cylinder, at least temporarily smaller or larger amounts of fibers are fed to the comb-in zone than corresponds to the synchronous amount of fibers.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a sewing machine for large-surface, stationary material such as quilts, comprising at least two units each including a sewing head and associated shuttle box, each unit being displaceable on an arch-frame in the x-direction and the arch-frame itself being displaceable in the y-direction.
2. Description of the Related Art
Sewing machines of the above species are already known. In particular they are stitching machines for large-surface materials which are at rest during stitching, the sewing head(s) as well as the shuttle boxes being displaceable in two mutually orthogonal directions, the x- and y-directions, in the plane of the material, in order to produce the stitching paths above or below the material. The sewing member(s) is (are) located on an arch-frame, that is the sewing heads together with the needle drive are mounted on the upper arch-frame crossbeam and the shuttle box(es) together with the shuttle drive on the lower crossbeam. During sewing, the entire arch-frame can be moved at will forward and back in one direction, the y-direction. The sewing member(s) on the arch-frame can be moved in another direction, namely at 90° to the arch-frame displacement, namely in the x-direction. The drive and control concerning the x- and y-directions are implemented in known manner by electrical or electronic means in turn so controlling motors for the x- and y-directions that the resulting motion of the sewing members corresponds to the stitching path. When two or more sewing members are mounted on the arch-frame and are displaced as described, two or more parallel seams spaced apart by the distance between the sewing members are obtained.
Two or more sewing members are desired in such sewing machines because the sewing or stitching as a whole can be substantially accelerated and the products are thus made in a correspondingly shorter time, there being comparatively little increase in equipment on account of the several sewing members in relation to the overall machine. The sewing members mentioned herein are hereafter called sewing units for the sake of simplicity and comprise each of a sewing head with needle drive and of a shuttle box with shuttle drive. The basic problem which must be kept in mind is that the sewing head and the shuttle box always must be made to move accurately relative to each other in terms of fractions of a mm, for instance with 0.1 mm accuracy, as otherwise there may be collisions between the needle and the shuttles.
As regards sewing machines with two or more sewing members or units, there is a particular problem when selecting a new stitching pattern and hence when the spacing between the sewing members must be changed. In the light of the required accuracy, such a change in spacing even where only two sewing members are involved will entail substantial and very time-consuming labor of conversion and adjustment.
SUMMARY OF THE INVENTION
Accordingly, it is the object of the invention to create a sewing machine making it possible to convert to a new sewing program in the shortest possible time with the greatest accuracy.
In accordance with the invention one unit can be disengaged from a common drive and can be fixed in a precisely defined parked or parking position, for the purpose of changing the spacing between the units, and the other unit can be moved by means of the common drive into the desired new distance position, and the unit in the parking position can then be re-engaged.
As a result a substantial advantage is achieved because the precisely defined parking position is sensed by the control or control computer and thereupon the remaining sewing member(s) or unit(s) can be moved in controlled manner relative to the unit in the parked position.
In further accordance with the invention a particular unit can be disengaged from the common drive and is freely displaceable for the purpose of changing the inter-unit distance by adjustment to the newly selected distance in relation to a pattern of the drive pitch and can be re-engaged.
A substantial advantage is achieved because the sewing heads and the associated shuttle boxes can be arbitrarily displaced and independently spaced from each other after disengagement from the common drive and then can be re-engaged. Because the common drive comprises a scale, the accuracy of this scale can be used to move the sewing heads and the associated shuttle boxes into a mutually accurate position so that there shall be no need for later fine-adjustment between the sewing heads and the shuttle boxes. Accordingly it is enough to displace the particular sewing head and the associated shuttle box along the scale graduations. Upon engaging, or re-engaging, the accuracy of the scale and of the total common drive ensures adequately accurate mutual adjustment between the sewing heads and the shuttle boxes. Advantageously too, each arbitrary desired number of sewing heads and shuttle boxes may be combined, as a result of which sewing can be accelerated as a whole. Converting to a new sewing program also is simplified thereby.
The design of the sewing machine of the invention cited above also may be such that in order to change the distances between the units, one unit always can be disengaged from the common drive and can be freely displaceable and, according to a scale on the drive, it can be adjusted for the newly selected distance and can be re-engaged.
In another embodiment of the invention, at least one unit can be disengaged from a common drive and can be fixed in position in the x-direction for the purpose of changing the inter-unit distance, and other unit can be moved in a controlled manner by the common drive into a new position which is the desired distance from the affixed unit, and the distance position is measured by a distance sensor and this unit shall be re-engaged to the common drive when it arrives at the new distance position.
The drawing schematically shows illustrative embodiment modes of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective of the overall sewing machine shown in simplified form,
FIG. 2 is a front view of a cutaway of FIG. 1, namely of an enlarged unit partly shown in cutaway form,
FIG. 3 is an end view of FIG. 2, partly in vertical section,
FIG. 4 is a front view of a cutaway of another sewing machine,
FIG. 5 is an end view relating to FIG. 4, partly in vertical section,
FIG. 6 is a cutaway of embodiment mode and on an enlarged scale,
FIG. 7 is a sideview of a vertical section relating to FIG. 6,
FIG. 8 is a partial vertical section of a detail elsewhere than shown in FIG. 7,
FIG. 9 is a view according to FIG. 1 but for another embodiment, and
FIG. 10 is a view according to FIG. 1 but also for another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a simplified perspective view of an illustrative embodiment of the sewing machine of the invention. An arch-frame 3 rests in displaceable manner in the y-direction on stationary rails 1 and 2 by an omitted motor and control means. Essentially the arch-frame 3 consists of two side posts 4 and 5 connected by crossbeams 6 and 7. The arch-frame 3 rests on riding feet 8 and 9. The large-surface sewing material 13, for instance a quilt of a specific thickness shown by the cutaway edge, is held and tensioned in a frame 10 affixed in fasteners 11 and 12.
In the embodiment shown, two sewing heads 14 and 15 are located on the upper crossbeam 6 and two associated shuttle boxes 16 and 17 are present on the lower crossbeam 7. The two units, namely the sewing head 14 and the shuttle box 16 and the sewing head 15 and the shuttle box 17, are moved by a common drive. In this embodiment, the common drive comprises two endless toothed belts 18 and 19 passing at the ends of the crossbeams 6 and 7 of the arch-frame 3 around reversing toothed rollers or gears 43, 44, 45 and 46. Furthermore the two endless belts are connected by a connection belt 20 driving them jointly, it being understood that the connection belt 20, which is also an endless belt, passes around separate reversing toothed rollers (not shown) mounted coaxially with the reversing toothed rollers 43 and 46, respectively. Also a drive motor 21 is present in FIG. 1 to move the said units 14, 16; 15, 17 in the x-direction on the arch-frame 3. In this embodiment the drive motor 21 is connected to the drive shaft (unnumbered) of the reversing roller 46.
FIGS. 2 and 3 illustrate the precise position-matching of the sewing head 15 and of the shuttle box 17 by showing the press foot 22 (FIG. 2) and the needle clamp 23 (FIG. 3) with the needle (unnumbered) on one hand and the shuttle 24 (FIG. 2) on the other. The sewing heads 14 and 15 and the shuttle boxes 16 and 17 are guided on two guide bars 25, 26 and 27, 28, respectively, of the respective crossbeams 6 and 7 of the arch-frame 3. These guide bars 25 through 28 are linked by supports 29 (FIG. 3) to the crossbeams 6, 7 and contribute to the accurate guidance and positioning of sewing heads 14, 15 and shuttle boxes 16, 17. The connection between the guide bars 29 and the sewing heads 14, 15 as well as the shuttle boxes 16, 17 is implemented by slide pads 30 shown in FIG. 3.
The sewing heads 14, 15 and the shuttle boxes 16, 17 can be linked by a coupling to a segment or portion 31 and 32, respectively, of the endless belts 18 and 19. As shown in FIGS. 2 and 3, the coupling consists of disengaging and re-engaging means including a coupling member 35 which by means of an actuator 34 can be vertically displaced on a support plate 33, and of a matching plate 37, as a result of which a selected segment of the endless belts 18, 19 can be firmly clamped by these parts.
The endless belts 18, 19 may be smooth belts and in that case the described coupling parts may act on any side. To achieve even greater reliability against slippage during operation, the endless belts 18, 19 also may be toothed belts, as shown in the drawing. In that case the coupling member 35 will be fitted with toothing matching the toothed belts 18, 19. Moreover the coupling member 35 may be precisely adjusted in the x-direction by means of a control system 36 shown in simplified manner.
When the distance between the units 14, 16 and 15, 17 must be changed, for instance when a new sewing program must be selected, one of the units, namely, according to FIGS. 2 and 3, the sewing head 15 and the shuttle box 17, is moved into a precisely defined parked position as shown by the dot-dash line 38 of FIG. 2. This parked position 38 is determined by stationary magnetic clamps 39 and 40, in particular electromagnets, and by magnetic plates 41 and 42 at the sewing head 15 and shuttle box 17. The unit 15, 17 first is moved by the common drive 18-21 to the right until the magnetic plates 41 and 42 impact and stop against the magnetic clamps 39 and 40, as a result of which this unit 15, 17 then is retained in the parked position 38. Next the coupling or coupling members 35 are released, that is, this unit 15, 17 in the parked position 38 is disengaged from the endless belts 18, 19 of the common drive 18-20. Now the unit 14, 16 which has its coupling members engaged with the endless belts 18, 19, respectively, can be moved by the common drive 18-20 into the new position at the newly desired distance from the unit 15, 17 in the parked position 38. Once the new distance position has been reached, the unit 15, 17 in the parked position 38 can again be linked to the common drive 18-21 through the coupling members 35 and the endless belts 18, 19 and thereby the new sewing program can then be carried out.
Advantageously the described parked position 38 with the magnetic clamps 39, 40 are located near one end of the arch-frame 3, that is near the right end of FIG. 1, as indicated therein by the phantom outline of the unit 15, 17. However and in particular as regards more than two units, the parked position 38 under some circumstances also may be located at some other site of the arch-frame 3. Ilustratively, if there are three units on the arch-frame 3, the central unit first may be moved into the parked position at any suitable arch-frame location, or the units may be moved alternatingly into the parked positions in order to adjust the mutual distances.
As already mentioned above, the sewing machine is equipped with an electrical or electronic control of such design that the positions of all units 14, 16; 15, 17 can be ascertained or recorded at all times during sewing.
Be it further borne in mind that the invention is not restricted to the above preferred common drive 18-20 described above. A common drive also may be used which shall comprise two spindles parallel to the crossbeams 6, 7 of the arch-frame 3, said spindles bearing fixed nuts for the sewing heads and shuttle boxes, respectively. Those nuts of the unit in the parked position may be loosened, as a result of which these nuts revolve loosely together with the spindles without displacement. As soon as these nuts are fastened again, the common drive becomes effective again for all units.
FIGS. 4 through 8 illustrate a further embodimetn of the sewing machine of the invention. This embodiment coincides with that of FIGS. 1 through 3 as regards all identical or equivalent components identified by reference numerals 1 through 37 and 43 through 46, and accordingly the description of FIGS. 1 through 3 also applies to the embodiment of FIGS. 4 through 8. However, in FIGS. 1-3 the belts are in the form of endless smooth belts 18 and 19 and a toothed connection belt 20, and the reversing rollers are designed as reversing gears 43, 44, 45 and 46. Again separate reversing gears are provided for the smooth connection belt 20 and are mounted coaxially with the reversing gears 43 and 46.
The coupling member 35 is also smooth matching the smooth endless belts 18, 19. Moreover, the coupling member 35 can be accurately adjusted in the x-direction during first set-up by means of a control device 36 shown in simplified manner.
It was already explained above that the sewing heads 14, 15 and the shuttle boxes 16, 17 can engage each by coupling a belt segment 31, 32 of the endless toothed belt 18, 19. FIGS. 8 through 10 illustrate a preferred design. Therein the actuator comprises two levers 47 and 48 pivotally connected together and to the coupling member 35. The pivots are denoted by reference numerals 50, 51 and 52. The upper part of FIG. 7 shows the operational position, wherein the coupling member 35 is disengaged from the upper segment 31 of the endless toothed belt 18. This is implemented by pivoting the lever arm 49 clockwise. The lever 48, specifically the lever part (unnumbered) extended to the right, comprises a slot or clearance 54 entered by a stop bolt 53, as a result of which the vertical displacement of the coupling member 35 is limited in the downward direction. By pivoting the lever arm 49 counter-clockwise, the coupling member 35 is moved upward and thereby its toothing engages the correspondingly selected toothing of the upper segment 31, 32 of the endless toothed belts 18, 19, respectively.
If now the distance between the units (not shown) must be changed, for instance when another sewing program is selected, then the units comprising the sewing head and the shuttle box can be disengaged from the endless toothed belts 18, 19 and then can be shifted arbitrarily. Thereupon, in the newly selected position, the sewing head and the shuttle box can be re-engaged. Because of the accurate pitch of the endless toothed belts 18, 19 accurate mutual array of sewing head and shuttle box is then easily implemented.
In order to further facilitate adjustment in practice, advantageously at least one of the two endless toothed belts 18, 19 may be fitted with a scale (not shown) so that the distance between any two units is fixed in simple manner. As an alternative to this kind of adjustment, at least one of the two crossbeams 6 and 7 is fitted with a scale in such a way that the distance between any two units again can be set in simple manner.
Another design solution relating to the drive comprises as the common drive two endless chains passing around sprocket wheels. The pitch is then determined by the chain links. This embodiment mode is not shown in the drawings, however it is easily put into practice by replacing the endless toothed belts 18, 19 with corresponding endless chains. Obviously in such a case the connection toothed belt 20 shall be replaced by a corresponding connection chain.
FIGS. 9 and 10 illustrate further embodiments of the sewing machine of the invention basically coinciding to the embodiment of FIG. 1. However, the embodiments shown in FIGS. 9 and 10 differ in that to change a distance D between the units 14, 16 and 15, 17, at least one unit can be disengaged from the common drive 18, 19, 20 and can be affixed in the x-direction. The particular other unit can be controlled by the common drive (18, 19, etc.) to move into a desired new distance position. What is especially significant in this instance is that the distance position is measured by a distance sensor. As soon as this unit has reached the new distance position, it can be re-engaged to the common drive (18, 19, etc.). In the embodiment mode of FIG. 9, the unit 14, 16 may remain rigidly joined to the common drive 18, 19, 20 whereas the other unit 15, 17 shall be disengaged from the common drive for the x-direction and shall be re-engaged to it again once the new distance position has been reached. This embodiment also applies in this sense to the design of FIG. 10.
Now FIG. 9 shows the feature that the distance sensor consists of two transmitters 55 and 57 and two receivers 56, 58 which, as shown in the drawing, are mounted to the particular sewing heads 14 and 15 and to the shuttle boxes 16, 17. These distance sensors may be designed as ultrasonic or laser sensors. Such distance sensors are known from other engineering fields and are commerically available, and therefore their technical details need not be described here.
FIG. 10 illustrates another design of distance sensors which are mounted to the unit to be adjusted, for instance the unit of sewing head 15 and shuttle box 17, and such distance sensors are in the form of rotary displacement pickups 59 constantly engaging the common drive 18, 19, 20. These rotary displacement pickups may be in the form of so-called resolvers or as incremental or absolute shaft encoders. These displacement pickups 59 comprise wheels constantly engaging in slip-free manner the particular drive belt for the displacement in x-axis. The wheels may be gears which in that case engage corresponding endless toothed belts. These displacement pickups remain engaged with the endless belts even when the associated sewing head 15 and the shuttle box 17 are disengaged from the particular drive means for the x-axis, for instance the particular drive belt. Upon analysis, the rotary motion of the displacement pickups forms a measure of the particular distance present and lastly also of the new distance position between the two units.
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A sewing machine for sewing stationary large surface material (13) includes at least two units (14, 16 and 15, 17) of which includes a sewing head (14, 15) and an associated shuttle box (16, 17) which are displaceably mounted for movement in the first (x) and second (y) directions substantially normal to each other. A common drive mechanism (18, 19, etc.) displaces the unit simultaneously in the first direction (x) while spaced a predetermined distance (D) from each other while an associated disengaging mechanism (35) can controllably disengage one of the units (14, 16 or 15, 17) from the common drive (18, 19, etc.) while the other unit is displaced by the common drive to thereby change the predetermined distance (D) after which the one unit is re-engaged. Preferably holding mechanisms are provided for holding the disengaged sewing head (14 or 15) and the disengaged shuttle box (16, 17) of the disengaged one of the units (14, 16 or 15, 17) substantially stationary during the displacement of the other unit, and preferably the stationary unit is maintained substantially stationary at a parked position (38) during the displacement of the other unit.
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TECHNICAL FIELD
The present invention relates generally to video signal processing and more specifically to a system and method for inserting data into a standard video signal.
BACKGROUND OF THE INVENTION
The use of television is commonplace in the United States and throughout the world. Nearly every home in the United States has at least one television set. Many homes have cable television, which couples a large number of television channels to the home through a single coaxial cable. Other homes and businesses may have satellite receivers that are capable of receiving television signals from a number of satellites in stationary orbit around the earth.
Television signals are defined by the National Television Standards Committee (NTSC). Each television signal comprises a video signal and an audio signal. The NTSC signal, which evolved when only black and white (B/W) television was available has a baseband bandwidth of approximately 4.7 megahertz (MHz). The NTSC signal is modulated to a predetermined carrier frequency. For example, VHF channel 2 has a carrier frequency of 55.25 MHz. A small spacing in the frequency spectrum between adjacent channels prevents interference between channels. The bandwidth of the modulated signal is approximately 6.0 MHz. Other transmission systems, such as cable broadcasting, may use different frequencies for the television channels.
When color television was introduced, it was important that the color signals be added in a manner that did not interfere with the normal operation of B/W television signals. This was accomplished by introducing a chrominance signal modulated at a frequency that causes the chrominance signal for each line of the television signal to have an inverted phase with respect to the prior line. There are an odd number of lines in each television frame, with the result being that the chrominance signal for any given line is inverted in alternating frames of the television signal. The phase inversion causes the chrominance signal to cancel out temporally over the time of one frame, and spatially in the vertical axis over the space of two lines. The cancellation prevents the chrominance signal from erroneously being interpreted as part of the luminance signal. This effect, combined with the known persistence of vision in humans causes the chrominance signal to effectively cancel out in a B/W television so that it causes no noticeable interference. The NTSC signal has a modulated chrominance signal that overlaps the luminance signal in a portion of the frequency spectrum where the overlap causes minimal interference.
The frequency spectrum of the NTSC signal is shown in FIG. 1A. As can be seen in FIG. 1A, the video signal comprises a luminance signal 2 and a chrominance signal 4. The luminance signal 2 provides the signal intensity for both B/W and color television signals. The luminance signal 2 has spectral peaks 6 every 15.75 kilohertz (kHz), which corresponds to the horizontal frequency in the television. The amplitude of the luminance spectral peaks 6 decreases up to 4.2 MHz. The video signal is suppressed above 4.2 MHz to permit the insertion of an audio signal 5 in the spectrum for the particular video channel. The audio signal 5 is modulated with a 4.5 MHz carrier.
The chrominance signal 4 is introduced beginning at about 2 MHz in the spectrum. The chrominance signal 4 has chrominance spectral peaks 8, which are also spaced 15.75 MHz apart in the frequency spectrum. The chrominance signal is modulated at a frequency of 3.579545 MHz (an odd multiple of half the line scan frequency) to cause the chrominance signal peaks to interlace with the luminance peaks, as shown in FIG. 1B, which illustrates a magnified portion of the spectrum of FIG. 1A.
As seen in FIG. 1B, the luminance spectral peaks 6 and the chrominance spectral peaks 8 are spaced apart by 7.875 kHz. Although FIG. 1B, shows the frequency spectrum with no overlap, there is some degree of overlap in these signals due to the non-periodicity of the signals with respect to the line scan frequency.
The NTSC signal has temporal characteristics as well as the frequency characteristics described above. A single video frame comprises 525 video lines that are displayed in two interlaced video fields. Each video field is displayed with a vertical display rate of approximately 60 Hz (59.94 Hz) so that a video frame (with two interlaced video fields) is displayed at a vertical display rate of approximately 30 Hz (29.97 Hz). As seen in FIG. 2, there are two luminance peaks L1 and L2, spaced apart in the frequency spectrum by 30 Hz. The chrominance signal 4 is inserted between alternating pairs of luminance peaks 6. If one selects an arbitrary luminance peak L1 as a reference luminance peak, it is readily seen that the chrominance signal 4 has a spectral peak C 15 Hz above the reference luminance line peak L1. A second luminance peak L2 is spaced 15 Hz above the chrominance peak C (and 30 Hz above the reference luminance peak L1 ). The luminance peak L1 appears again 60 Hz above the reference luminance peak L1. Thus, the pattern repeats every 60 Hz. It should be noted that there is no signal in the spectrum 45 Hz from the reference luminance peak L1. As described in the prior art, that spectral "hole" in the spectrum is currently unused, and could carry additional information. The frequency spectrum of the NTSC signal with additional information signal D added is shown in FIG. 3. Note that the additional information signal is added to an unused portion of the spectrum that, in an ideal case, will cause no interference with the normal video signal processing.
The use of this spectral hole is described in U.S. Pat. No. 4,660,072, which is incorporated herein by reference. The patent describes a technique for adding an additional luminance signal to a standard video signal by inserting the additional luminance signal into the unused portion of the spectrum. The system disclosed in the patent modulates a high frequency luminance signal with a 3.579545 MHz carrier that abruptly switches phase every field of the NTSC signal (60 Hz). The carrier signal is thus modulated by a 30 Hz square wave that has alternating phases of the carrier signal.
The selected carrier frequency and alternating phases cause the additional luminance signal to cancel out temporally and spatially in the same manner as the chrominance signal. The additional luminance signal ideally averages to zero, but in reality the signal averages to zero only if it is unchanging over time. Thus, the additional luminance signal will completely cancel only if it is unchanging. In signal processing terms, only common mode signals are completely canceled. Differential signals do not cancel each other out and will remain in the NTSC signal as a residual signal that may cause interference with the luminance signal. The amount of residual signal depends on the bandwidth of the additional luminance signal and the correlation of the additional luminance signal with the NTSC standard luminance signal. The greater the bandwidth of the additional luminance signal, the greater the amount of additional luminance signal that will feed through and become visible to the television viewer (in the form of interference). In addition, the less correlation between the additional luminance signal and the NTSC standard luminance signal, the greater the amount of additional luminance signal that will feed through and become visible to the television viewer in the form of interference.
The selection of a 30 Hz square wave as a modulation source creates additional problems not solved by the system described in the U.S. Pat. No. 4,660,072. Because an ideal square wave contains an infinite number of odd harmonics, the additional luminance signal is modulated not only at 30 Hz, but at all odd harmonics of these two signals as well. The modulation by many multiple frequencies increases the possibility that the additional luminance signal will overlap in the frequency domain with the video signal. The overlap with the video signal may not present a significant problem in the application described in the patent because the additional luminance signal is highly correlated with the NTSC standard luminance signal, so the interference may not be noticed by the viewer.
However, if the additional information signal added to the standard video signal is unrelated to the video signal, the approach disclosed in U.S. Pat. No. 4,660,072 may be unsuitable because the interference with the video signal may be intolerable. Furthermore, there may be unacceptable interference for the additional information signal itself. To avoid interference, it is necessary to reduce the bandwidth of the additional information signal. There is theoretically a 1.8 MHz bandwidth available in the unused portion of the chrominance spectrum. Because standard modulation creates two sidebands, the actual data bandwidth is limited to 0.9 MHz. The modulation technique proposed in U.S. Pat. No. 4,660,072 causes an unacceptable spectral spreading of the additional information signal that can cause interference with normal television operation.
Therefore, it can be appreciated that there is a significant need for a system and method for introducing an additional information signal into a video signal without the undesirable effects of signal interference or reducing bandwidth to avoid interference.
SUMMARY OF THE INVENTION
The invention is embodied in a system for inserting a data signal into a video signal. The system comprises a first filter which receives the data signal and produces a filtered signal having filter characteristics that permit the insertion of the filtered signal into an unused portion of the spectrum of the video signal. Modulator elements modulate a carrier frequency with the filtered signal to produce a modulated filtered signal. The carrier frequency is selected to permit the insertion of the filtered signal into the unused portion of the spectrum of the video signal to produce a modified video signal containing the modulated filtered signal with the filtered signal inserted into the unused portion of the spectrum of the video signal. A signal separator in a receiver portion separates the filtered signal from the modified video signal and a second filter receives the filtered signal from the signal separator and recovers the data signal from the filtered signal.
In one embodiment, the first filter is a comb filter with at least two taps. The comb filter comprises a delay circuit which delays the data signal by a predetermined period of time and an adder to add the data signal with the delayed data signal to produce the filtered signal. The delay circuit may be a first-in, first-out buffer, or an analog delay line. The predetermined period of time used by the delay circuit is 1/60th of a second such that the filtered signal contains substantially uniform spectral peaks with the 60 Hz spacing.
In an alternative embodiment, the first filter is a data buffer containing at least a portion of the data signal with the filter signal being generated by continuously replaying the data signal contained within the data buffer at a predetermined rate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A depicts the spectrum of a standard NTSC signal according to the prior art.
FIG. 1B is an enlarged view of a portion of the NTSC signal in FIG. 1A.
FIG. 2 depicts individual spectral lines in the NTSC signal of FIG. 1A.
FIG. 3 depicts the introduction of an additional information signal into the NTSC signal of FIG. 2 according to the prior art.
FIG. 4 is a functional block diagram of the system of the present invention.
FIG. 5 illustrates a data buffer filter implementation of the system of FIG. 4.
FIG. 6 illustrates an alternative comb filter implementation of the system of FIG. 4.
FIG. 7A depicts a typical waveform input to the comb filter of FIG. 6.
FIG. 7B depicts the waveform of FIG. 7A after passing through the delay line of the comb filter of FIG. 6.
FIG. 7C depicts the filtered output from the comb filter of FIG. 6.
FIG. 7D depicts the spectrum of the comb filter of FIG. 6.
FIG. 7E depicts the spectrum of an NTSC signal with the insertion of the filtered output signal of FIG. 7C.
FIG. 8 illustrates an example of an inverse comb filter used by the system of FIG. 4 to reconstruct the data signal.
DETAILED DESCRIPTION OF THE INVENTION
The present invention resides in a system and method for introducing an additional information signal into an NTSC signal without a reduction in bandwidth. The additional information signal may be an analog data signal or a digital data signal. Whichever form the additional information signal may take, it will be referred to herein as a data signal.
As previously discussed, the technique disclosed in U.S. Pat. No. 4,660,072 modulates the incoming data signal with the 3.579545 MHz carrier signal that switches the phase of the carrier signal at a 30 Hz rate. The method described therein requires that data be frame periodic so that the inserted data signal does not become visible to the viewer in the form of interference. That is, the inserted data signal must repeat itself each frame, but with opposite phase so that the data cancels out, making the inserted data signal invisible to the viewer. Unfortunately, this means that the effective bandwidth is reduced to one-half the theoretical bandwidth because the data is repeated each frame. This approach also requires that a frame of data be stored in a buffer so that it can be inserted twice. A large buffer complicates the circuit design and increases the cost of the circuit.
The present invention inserts a data signal into the unused portion of the spectrum in a manner that does not require complex modulation of the data signal and which prevents the data signal from interfering with the video signal. The data signal is filtered and modulated by a simple modulator so that the data signal can be directly inserted into the video signal.
The invention is embodied in a system 100 shown in functional block diagram form in FIG. 4. A transmitter portion 102 of the system 100 has a data signal 104 filtered by a filter 106 to generate a filtered data signal 108. Two embodiments of the filter 106 will be described in detail below. The filtered signal 108 is modulated by a simple modulator 110 to produce a modulated data signal 111. The modulated data signal 111 is added to a standard NTSC video signal 112 by an adder 114. The modulator 110 will be described in detail below. The filter 106 prevents the data signal 104 from causing interference in the NTSC video signal 112. The adder 114 is a conventional component that sums the modulated data signal 111 and the NTSC video signal 112 to generate a modified NTSC video signal 118 that contains both the NTSC video signal and the data signal 104 inserted into the unused portion of the spectrum (i.e., in the spectral holes previously discussed). The modified NTSC video signal 118 is transmitted by a transmitter 120. The output of the transmitter 120 is a transmitted signal 122. There are many well-known television transmitters that can be used satisfactorily with the system 100. The transmitter 120 may be a conventional television transmitter, a transmitter such as those used by conventional cable television companies, a signal generated by a video recorder or the like. Details of the transmitter 120 are not discussed herein. The actual type of transmitter 120 should not be considered a limitation of the system 100.
The type of transmitter 120 depends on the transmission medium in which the transmitted signal 122 is transmitted. The transmitted signal 122 may be any type of electromagnetic signals such as radio frequency signals, electrical signals on a wire cable, optical signals on a fiber-optic cable, signals on a magnetic media, or the like.
A receiver portion 126 of the system 100 contains a video signal processor 128 that receives the transmitted signal 122 and processes it to recover the NTSC video signal 112. The video signal processor 128 is a conventional television component and is not discussed herein. The data signal 104 has been previously added to the NTSC video signal 112 in a manner that causes the video signal processor 128 to cancel the data signal 104 from the NTSC video signal 112 as is known in the prior art. Thus, the output of the video signal processor 128 is the standard NTSC video signal 112 with little or no interference caused by the data signal 104. The NTSC video signal 112 is then processed as a normal video signal without the data signal 104.
A signal separator 130 in the receiver portion 126 also receives the transmitted signal 122 and separates the modulated data signal 111 from the transmitted signal. The signal separator 130 uses conventional television chrominance signal processing components to separate the modulated data signal 111 from the transmitted signal 122. The details of the signal separator 130 are well known by those of ordinary skill in the art and will not be discussed in detail herein. Details of other television circuit elements such as a tuner are also omitted for brevity.
The modulated data signal 111 is demodulated by a demodulator/filter 132 to recover the filtered signal 108. The demodulator/filter 132 will be discussed in detail below. The filtered signal 108 is processed by an inverse filter 134 to recover the original data signal 104. The inverse filter 134 may be a 60 Hz comb filter that is applied to the filtered signal 108.
The data signal 104 may be an analog signal or a digital data signal, such as would be useful for the transmission of digital music, database information, computer subscriber data, or the like. The subsequent processing of the data signal 104 in the receiver portion 126 depends on the particular form of the data signal (i.e., analog or digital), and the particular application for which the data signal is intended (e.g., digital music).
RECIRCULATING BUFFER
In one embodiment of the invention shown in FIG. 5, the filter 106 is implemented using a data buffer 180. The data buffer 180 stores at least a part of the data signal 104 and continuously plays out the data at a predetermined periodic rate. According to one aspect of the well-known Parseval's theorem, no energy will exist in the spectrum except at integer multiples of the periodic rate. In the present embodiment, the data buffer 180 is 1/60 second in length and is played back continuously at a 60 Hz rate. This results in a line spectrum, similar to the comb filter, with 60 Hz spacing in the spectral peaks. Obviously, other buffer sizes and predetermined periodic rates could be readily used with the system 100. For example, a 1/30 second buffer played out at a rate of 120 Hz will provide compatible spectral spacing of 120 Hz. The output of the data buffer 180 is the filtered signal 108. The filter signal 108 is coupled to the modulator 110, and the remainder of the transmitter portion 102 (see FIG. 4) operates in an identical manner as described above.
The same data within the data buffer 180 is repeated in order to create the line spectrum with the 60 Hz spacing. However, the data buffer 180 must also be updated so that a continuous stream of data is inserted into the NTSC video signal 112. In the present embodiment, a control circuit 182 controls the rate at which the data is changed within the data buffer 180. The data within the data buffer 180 is changed after each 2 to 4 repetitions in which the data is repeated by the data buffer 180. This repetition of the data has the effect of reducing the bandwidth of the data signal 104, but the circuitry to implement the filter 106 is relatively simple and the temporal cancellation is greater thus reducing the visibility of the data signal within the NTSC video signal. For example, the data within the data buffer 180 may be divided into four subsets, designated herein as subsets a through d. The data buffer 180 initially plays out all four subsets a through d. While cycles b-d are being played out, the control circuit 182 causes subset a in the data buffer 180 to be replaced with new data. The next time the data buffer 180 plays out the subsets a-d, with subset a containing the updated data. During this repetition, the control circuit 182 replaces subset b with new data. The buffer 180 continuously plays out the subsets a-d, and the control circuit 182 replaces one subset with new data during each repetition. Thus, the one fourth of the data within the data buffer 180 is replaced each time that the data buffer repeats. Alternatively, the data buffer 180 could be slowly changed each time it is repeated so that the data is completely changed every 2 to 4 times that the data is repeated by the data buffer 180.
COMB FILTER
The filter 106 may comprise any number of well-known embodiments. An alternative embodiment of the filter 106 is a comb filter, shown in FIG. 6, where the data signal 104 is added to a delayed version of itself to create the same effect in the spectrum of the signal as the recirculating buffer discussed above. One advantage of the comb filter is that it does not require that the data signal be frame periodic to prevent the data signal from interfering with the video signal. A delay line 140 receives the data signal 104 and provides a predetermined delay, Δt, to produce a delayed data signal 142. The delay line may be a first-in, first-out buffer, an analog delay line, or the like. The delayed data signal 142 and the data signal 104 are added together by an adder 144 to produce the filtered signal 108.
FIGS. 7A through 7C illustrate the comb filter process using the filter 106 of FIG. 6 in the time domain. The data signal 104 is shown in FIG. 7A and the delayed data signal 142 is shown in FIG. 7B. The sum of the data signal 104 and the delayed data signal 142, which produces the filtered signal 108, is shown in FIG. 7C.
The filtered signal 108 is shown in the frequency domain in FIG. 7D. The spacing, 1/Δt, between peaks 148 of the spectrum of the filtered signal 108 is determined by the delay time of the delay line 140. In this particular example, the delay time is 1/60 of a second which causes the peaks 148 to have a 60 Hz spacing. This spacing permits the filtered signal 108 to fit precisely in the unused portion of the spectrum between the luminance signal peaks where the chrominance signal peaks are not present. The filter 106 embodiment of FIG. 6 is a two-tap comb filter. Obviously, comb filters with more than two taps may also be employed. The more taps that are used in the comb filter, the more narrow the spectral peaks 148 (see FIG. 7D) and the greater the attenuation of the signal in the filter stop band between the spectral peaks 148. Other filters producing similar spectral characteristics may also be employed with the system 100.
Referring again to FIG.4, the modulator 110 is a simple modulator that receives the filter signal 108 and modulates it to fit into the unused portion of the spectrum previously discussed (i.e., the spectral holes). The modulator 110 can use any carrier frequency of 3.58 MHz±k*60 Hz+30 Hz, where k is any integer between 0 and approximately 18,000, which permits the filtered signal 108 to fit in the unused portion of the NTSC video signal 112. The upper limit for the integer, k, is selected so that the bandwidth of the data signal 104 is contained within the bandwidth (approximately ±1 MHz from the chrominance carrier) of the chrominance signal. It should be noted that these suggested modulation frequencies are selected to be centered within the unused portion of the spectrum. Obviously, other frequencies could also be used satisfactorily. By using a single carrier frequency for the modulator, the system 100 avoids the problem of the data signal spreading into a portion of the spectrum already occupied by the chrominance and luminance signals as occurs in the prior art. The spectrum of the signal generated by a single carrier frequency is well defined and allows the data signal 104 to be inserted into the unused portion of the spectrum without overlapping the signals already in the NTSC video signal 112. The output of the modulator 110 is the modulated data signal 111, which is added to the standard NTSC video signal 112 by the adder 114, as previously discussed. The output of the adder 114 is the modified NTSC video signal 118 that contains the NTSC video signal 112 with the data signal 104 inserted into the unused portion of the spectrum (i.e., in the spectral holes). The spectrum of the NTSC video signal with the filtered signal 108 inserted is shown in FIG. 7E.
The modified NTSC video signal 118 is transmitted by the transmitter 120 in any well-known manner to the receiver portion 126, such as by cable. The receiver portion 126 receives the transmitted signal 122 and recovers the data signal 104. The video signal processor 128 is a conventional television circuit that processes the video signal in the transmitted signal 122 and ignores the modulated data signal 111 that is also present in the transmitted signal 122. The signal separator 130 is a standard television component that processes the transmitted signal 122 and separates the modulated data signal 111 from the transmitted signal 122. In the presently preferred embodiment, the signal separator 130 is a bandpass filter centered about the chrominance carrier (3.58 MHz). The output of the signal separator 130 is the modulated data signal 111.
The demodulator/filter 132 is also a conventional television component that uses the same carrier frequency selected for the modulator 110. The modulated data signal 111 from the signal separator 130 is coupled to the demodulator/filter 132. The demodulator/filter 132 modulates the signal to generate the filtered data signal 108 centered at 0 Hz as well as an identical image centered at twice the selected carrier frequency. The selected carrier frequency and the identical image centered at twice the selected carrier frequency are removed by well-known lowpass filtering techniques. The output of the demodulator/filter 132 is the filtered signal 108 centered at 0 Hz. The filtered signal 108 contains the data signal 104, but in filtered form. The data signal 104 is recovered in the receiver portion 126 using the inverse filter 134.
The data signal 104 can be recovered from the filtered signal 108 by the use of simple mathematical manipulation well known to those of ordinary skill in the art. If the filter 106 is the comb filter of FIG. 6, the inverse filter 134 is also a 60 Hz comb filter. An example of the inverse filter 134 is shown in FIG. 8 where the filtered signal 108 is designated as N1. A delay line 152 receives the filtered signal, N1, and provides the predetermined delay, At, to produce a delayed filtered signal 154, which is designated as N2. The delayed filtered data signal 154 (N2) is subtracted from the filtered signal 108 (N1) by a subtractor 156 to provide a subtracted data signal 158, which is designated as N3. The output of the subtractor 156 is the data signal 104. Other embodiments of the inverse filter 134 are well known in the art and will not be described herein.
Thus, the original data signal 104 can be filtered, modulated and inserted into a standard video signal. The inserted data signal is transmitted along with the video signal. The inserted data signal is demodulated and inverse filtered to recover the original data signal. The data is processed by the transmitter portion 102 and the receiver portion 126 in a manner that does not interfere with the video signal or the normal video signal processing.
The above example is appropriate for a standard NTSC video signal for use with a 60 Hz television system. It will be obvious to those skilled in the art that the principles of the present invention can be applied to both analog and digital data signals, and may also be applied to video standards other than the NTSC system described herein. For example, the principles of the present invention are equally applicable to standard video signals such as a Phase Alternating Line (PAL) video signal used in Europe with a 50 Hz television transmission system. The delay line 140 may be implemented for both analog and digital forms of the data signal 104 If the data signal 104 is a digital signal, the delay line 140 may be a first-in-first-out shift register that provides the appropriate delay.
It is to be understood that even though various embodiments and advantages of the present invention have been set forth in the foregoing description, the above disclosure is illustrative only, and changes may be made in detail, yet remain within the broad principles of the invention. Therefore, the present invention is to be limited only by the appended claims.
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A system and method for inserting a data signal into a preexisting video signal in a transmitter so that the data signal is transmitted along with the video signal. The data signal is inserted into an unused portion of the video signal spectrum. The data signal is separated from the video signal in a receiver and may be used for any purpose, even purposes unrelated to the video signal. The data signal is filtered to create a filtered data signal having spectral characteristics that correspond to the unused portion of the video signal spectrum. The filtered signal modulates a carrier signal whose frequency is selected to permit direct insertion of the modulated filtered data signal into the video signal spectrum. In the receiver, the video signal is processed in a normal manner; and the data signal is undetected by normal television receivers. A signal separator separates the filtered data signal from the combined video signal, and an inverse filter recovers the original data signal. In one embodiment, a comb filter is used to generate the filtered data signal with 60 Hertz peaks. An inverse comb filter in the receiver recovers the original data signal. A recirculating buffer may also be used to generate the filtered data signal.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to software for implementing structures and methods of conducting debates and adversarial discussion among participants over a computer network. Specifically, it relates to software for enabling an efficient structure for online communication that promotes focused, time-saving, and rational discussions.
2. Discussion of Related Art
Although the number of present Internet and computer network applications and forums for conducting debates and adversarial discussions via electronic communication over a computer network is vast they have significant drawbacks.
Despite the vast increase in online communication and the growing prevalence of online debates and adversarial discussions, the quality of such discussions and debate has not improved. Free-form discussion methods such as e-mail, instant messaging, discussion-groups, and “chat rooms,” as well as live conversation or verbal argumentation, all suffer from weaknesses that make it difficult to foster rational and structured debate among participants because of their free form nature.
Online discussions began with Usenet Newsgroups, CompuServe Forums, and early e-mail which catered to a small minority of technical users. Over the past decade, these tools have grown and presently have millions of users who regularly discuss a wide range of topics, while e-mail, also used to discuss and debate issues, has become the single most widespread tool on the Internet. However, both modes of communication lack structure, have low content-to-noise ratios, and suffer from other drawbacks.
With online discussions, a typical discussion begins when one individual makes one or a series of points or statements which initiates a dialogue. Individuals responding to these points do so in any manner they wish. As a result current methods start with an argument which stems outwards in many directions. This outward meandering approach to responding to a point frequently results in the original point and its context getting lost while individuals pursue fragments of the original issue. It is only with considerable effort that both participants and observers can be mindful of all of the responses and points made and how they relate to the main argument. Given that online discussions can take place over significant periods of time, the cognitive overload required of the participants and observers (hereinafter “users”) often results in off-topic discussions because users fail to recall the original context.
Another problem arises from the fact that users often conflate an assumption—a belief that one accepts as true without support—and inferences and conclusions that they make from that assumption. This often inadvertent mixing of two different types of beliefs suggests implied support for an assumption that does not exist. Including hidden assumptions often dilutes a rigorous and disciplined debate or any type of rational dialogue and all assumptions should be distinguished from inferences, conclusions, and so on.
Another issue with traditional, free-form methods such as e-mail and discussion groups is that although communication within an adversarial discussion or debate often consists of two distinct phases, this distinction is lost or blurred with e-mail and discussion groups. The first phase consists of the back-and-forth between users where each is simply trying to understand what the others are trying to say or what their point is. The second phase is the distillation of what the true disagreement is—the “Aha!” moment—when two or more users realize what their differences really are. While the ‘back-and-forth’ phase is essential to reaching the “Aha!” moment, it is only the true disagreement that is fundamental to the adversarial discussion or debate. With present communication tools, forums, and applications there is no distinction between these two phases. The true point of disagreement is buried amid excessive noise leading to a high noise-to-content ratio.
Because of the unstructured, free-form characteristic of present tools for adversarial discussion, a frequent problem is digression, both intentional and unintentional, from the main point. Unintentional digression is expected within a context-free method given that a free-form structure allows users to unintentionally digress. In contrast, intentional digression often occurs in response to valid criticism of a position and is typically an attempt to distract other users from evaluating such criticism and to bury it amid other less insightful or relevant statements. Both forms of digression increase the cognitive load of users attempting to ascertain the relevant parts of a debate and are fundamentally detrimental to understanding, participating, and benefiting from an adversarial discussion of a topic.
Another drawback of present tools and forums stems from human nature's predisposition to try and ‘get the last word’ in a debate or discussion. As the phrase implies, ‘getting the last word’ means that a user or speaker is the last one to be heard in an argument. Present tools encourage this behavior which is a strong motivating factor to continue an argument beyond the point where the discussion is meaningful and worthwhile, exacerbating all the drawbacks described above. Furthermore, present tools by their very nature give a user with the highest number of statements or posts to a discussion a distinct advantage, allowing essentially a filibuster of a critique.
It is worth noting that the related field of Collaborative Argumentation generally assumes a cooperation of participants seeking a common goal and is not intended to foster adversarial discussion. Collaborative Argumentation methods result in enormous tree structures with the disadvantages described above. When a discussion is adversarial instead of cooperative then these tree structures become even more unwieldy due to the increased back-and-forth discussion among users who do not agree. This increases the cognitive loads on users as they try to keep the most relevant information in mind while attempting to block out the noise.
Thus, there is a need for an application and tool for conducting, facilitating and fostering rational and focused adversarial discussions.
SUMMARY OF THE INVENTION
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The features and advantages of the invention may be realized and obtained by means of the methods and configurations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth herein.
Method and systems for hosting and administering a forum for adversarial discussion over a computer network are described. In one aspect of the invention, a method of hosting an adversarial discussion, such as a debate, includes the step of accepting a first statement from a topic author. By submitting the first statement which can be an assumption or a conclusion, the topic author is creating a topic structure, which represents the basis for a discussion on a particular topic. The topic author adds statements to the topic structure that can support the first statement and can proceed to build the topic structure which is comprised of debate structures containing specific statements and related data, such as critiques, rebuttals, a revision history, and scores. Other discussion participants can react to the statements in a topic structure by submitting critiques of statements and can score statements, rebuttals, and other critiques that they did not author. A ranking results through the accumulation of scores or votes from many users. Statements, critiques, rebuttals, and other facets of a topic structure can be changed using various functional modules of the online debate application software of the present invention. A topic structure is manifested to the topic author and participants by at least two visual components: a statement map and a topic layout. In sum, the invention is the combination of a deductive structure and the ability to revise statements, critiques and rebuttals, referred to as revisioning. The deductive structure is comprised of one or more assumptions and conclusions. The revisioning aspect of the invention is comprised of critiques, rebuttals, a history of critiques and rebuttals, and modifications to the topic statements themselves. This aspect prevents digression and keeps the argument focused on the deductive structure. It creates a context that fosters users to look inward at the point of the argument and prevents the outward flow of the deductive structure. The structure is the context in which users may only revise critiques which affords an inward focus at the argument and prevents the outward flow of information.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to describe the manner in which the invention can be implemented, a more particular description of the invention briefly described above is provided by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and therefore are not to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
FIG. 1 . is a diagram showing a configuration of hardware components for enabling an online debate application tool and forum of the present invention;
FIG. 2 is a block diagram of some of the functional components of debate application software in accordance with one embodiment of the present invention;
FIG. 3 is a diagram of statements that can be made in a debate and how they are presented to a user as a topic layout in accordance with one embodiment of the present invention;
FIG. 4 is a block diagram of a topic structure in accordance with one embodiment of the present invention;
FIG. 5 is a block diagram of a debate structure in accordance with one embodiment of the present invention; and
FIG. 6 is a block diagram of a statement map in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Various embodiments of the invention are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other methods, structures, and configurations may be used without parting from the spirit and scope of the invention.
FIG. 1 is a diagram of a configuration of hardware components for enabling an online debate application tool and forum of the present invention. A computer network 100 , for example, the Internet, a VPN, an Ethernet network, and so on, connects an application server 102 to a plurality of various client computing devices. If computer network 100 is the Internet, there is also a Web server (not shown). Examples of client computer devices shown in FIG. 1 include desktop computers 104 and 110 , laptop computer 108 , a computer network-enabled cell phone 106 , and a computer network-enabled hand-held device 112 .
In a preferred embodiment, computer network 100 is the Internet and the devices are generally client desktop and laptop computers. However, other types of Internet-enabled devices can be utilized for executing the online debate application tool of the present invention. Private networks, such as those used in classrooms, private entities, government organizations, and home/residential networks, can also be used as a data transmission means for implementing the online debate application tool of the present invention.
Application server 102 contains online debate application software which implements the online debate/adversarial discussion tool of the present invention. In a preferred embodiment, no software or applications are downloaded to client computing devices. In another preferred embodiment, software can be downloaded onto the client devices for enhanced functionality of the online debate application software.
FIG. 2 is a block diagram of some of the functional components of debate application software 202 in accordance with one embodiment of the present invention. In a preferred embodiment, application software 202 resides and executes on application server 102 and the various client devices. Application software 202 contains the following components: topic addition/revision module 40 , rebuttal addition/revision module 42 , critique addition/revision module 41 , scoring module 45 , topic structure 70 , statement map creation module 44 , and display module 60 . The process generally begins with a user making a point and then expecting to defend it. The user makes a single statement or point, which can be an ASSUMPTION or an eventual CONCLUSION, that she wishes to defend thereby creating a topic structure 70 . No other users of the online debate application will see the topic until the topic author decides to publish topic structure 70 .
FIG. 3 is a diagram of statements that can be made in a debate and how they are presented to a user as a topic layout in accordance with one embodiment of the present invention. Shown are a series of ASSUMPTIONS # 1 , # 2 , # 3 , and # 4 , and a series of CONCLUSIONS # 1 and # 2 . The process starts with a user making a statement, e.g., “The death penalty is unconstitutional.” This statement is automatically labeled as an ASSUMPTION, e.g., “ASSUMPTION # 1 ”, because by default it has no supporting statements. By making this statement, the user is starting to create a topic structure 70 which will be displayed as topic layout 91 shown in FIG. 3 . The same user, the “topic author,” can make any number of statements for topic structure 70 . If the topic author wants to support ASSUMPTION # 1 , she can make supporting statements, e.g., “the death penalty amounts to cruel and unusual punishment” and “the vast majority of countries in the world consider the death penalty to be inhumane,” thereby establishing a supporting relationship between these statements and the first that changes the first statement from an ASSUMPTION to a CONCLUSION. An ASSUMPTION statement is converted to a CONCLUSION statement when it has another statement (either ASSUMPTION or CONCLUSION) supporting it. For example, CONCLUSION # 2 in FIG. 3 is a statement that is supported by an ASSUMPTION and a CONCLUSION.
The order in which statements are made by the topic author and the sequence of subsequent associations between them are irrelevant. A second statement is labeled an ASSUMPTION until the user adds a statement to support it at which time it becomes a CONCLUSION. This process continues for all statements until the topic author is confident that 1) each statement labeled as an ASSUMPTION, i.e., one that has no supporting statements, is truly something she is assuming and believes will be accepted as a fact or will not be contended, and 2) that each CONCLUSION, i.e., a statement that is supported by another statement, has all of the supporting statements she wants to provide. Of all the CONCLUSIONS made by the topic author, one or more will be considered the “point” of the discussion that the topic author wants to debate. Generally, the point will be the final CONCLUSION, that is, a CONCLUSION that is not supporting another statement. It is possible that an ASSUMPTION may be considered a point but it would very likely be considered by users to be a weak or trivial point and the topic author proceeds on this premise at her own adversarial peril.
FIG. 4 is a block diagram of a topic structure 70 in accordance with one embodiment of the present invention. A sub-component of topic structure 70 is a debate structure 80 . Also shown as part of topic structure 70 is a revision history 72 for topic structure 70 . In a preferred embodiment, topic structure 70 is comprised of one or more debate structures.
FIG. 5 is a block diagram of a debate structure in accordance with one embodiment of the present invention. Debate structure 80 is a single statement 81 or concept (which may require more than a single statement to be expressed), i.e., either an ASSUMPTION or CONCLUSION, and all of the data that may be associated with statement 81 , such as critiques 82 , rebuttals 83 , a debate structure revision history 84 , and scores 85 . Initially, when debate structure 80 is created, the only element of debate structure 80 that the topic author can change directly is statement 81 . A topic author may add rebuttals 83 at a later point thereby revising debate structure 80 . Otherwise a topic author cannot make a permanent change to debate structure 80 or to any other data she has posted for other users to see.
All users except the topic author can critique a statement 81 of any debate structure 80 . A critique is added by the application software using critique addition module 41 . Once a user has added a critique, the topic author may respond with a corresponding rebuttal 83 . Rebuttal 83 is added by the application software using rebuttal addition module 42 . In a preferred embodiment only the topic author can rebut a critique 82 to one of the author's statements in a given debate structure 71 .
The author of a critique 82 can revise the critique 82 . This is implemented by critique revision module 41 . Similarly, the topic author can revise her rebuttal 83 , implemented by rebuttal revision module 42 . Previous revisions of critiques 82 and rebuttals 83 can be viewed in revision history 84 of each debate structure 71 .
In a preferred embodiment, revision history 84 shows relationships of critiques 82 and rebuttals 83 , for example, which revised rebuttal was made in response to which critique. When a previous critique 82 is selected for display, a corresponding rebuttal 83 is also shown (and vice versa), thus providing context for the critique and rebuttal.
As mentioned, a topic author can revise a statement of a debate structure 71 that is in a topic structure 70 created by the author and republish using the topic revision module 40 .
Returning to topic structure 70 , once it has been created, the topic author can publish topic structure 70 using topic addition module 40 . Topic structure 70 can be composed of any number of debate structures. Debate structures are added to topic structure 70 using topic revision module 40 . Topic structure 70 is manifested to the public by two visual components of topic structure 70 : topic layout 91 shown in FIG. 3 and a statement map 90 shown in FIG. 6 , described below.
FIG. 6 is a block diagram of a statement map in accordance with one embodiment of the present invention. In a preferred embodiment, a user wanting to know the topic of debate will see, specifically, a statement map 90 and a topic layout 91 . Map 90 and layout 91 are displayed via display module 60 . Statement map 90 is generated by statement map creation module 44 which examines topic structure 70 in order to create map 90 . Topic layout 91 is also generated by examining topic structure 70 .
Once a topic structure 70 is published, statement map 90 and topic layout 91 are viewable to any user. Statement map 90 has boxes labeled A through F which correspond to ASSUMPTIONS and CONCLUSIONS in FIG. 3 . Characters are used in the illustration shown in FIG. 3 to prevent confusion. Numerals or other identifiers can be used to label the boxes. In a preferred embodiment, boxes that are shaded are ASSUMPTIONS and un-shaded boxes represent CONCLUSIONS. In other embodiments, ASSUMPTIONS and CONCLUSIONS are visually distinguishable in some other manner. The lines between the boxes represent that the statement above supports the statement below. This creates a top-down hierarchical map showing the logical support structure of a debate. The statement map feature allows users to easily visualize the structure of a debate: Are there many assumptions being made? Are conclusions being made based on assumptions or other conclusions? Is this an extensive, far-reaching argument or a concise one? and so on.
In a preferred embodiment, an ASSUMPTION 81 that remains unchanged after a topic structure revision carries forward its entire corresponding debate structure 71 including any related critiques 82 and rebuttals 83 given that ASSUMPTIONS have no dependencies. However, for the same ‘carry forward’ feature to apply for a CONCLUSION, there cannot be changes to any of the CONCLUSION's supporting debate structures. A topic author and other users are informed when an entire corresponding debate structure does not carry over. They are also informed when an ASSUMPTION has been changed.
In a preferred embodiment, the default viewing option is one where a user views a topic structure 70 wherein certain or, if desired, all critiques 82 and rebuttals 83 , are hidden. This option gives the user an uncluttered view of the original argument. A user also has the option of viewing any topic structure 70 , presented as topic layout 91 where each statement 81 within debate structure is displayed only with the most recent associated critiques 82 , rebuttals 83 and partial revision history 84 .
In another preferred embodiment, a topic author has the option of limiting which users can view or participate in an adversarial discussion. These users are identified in a “whitelist” of user and domain names. This allows entities such as a governmental organizations or universities, to limit discussion participants as desired.
In another embodiment, a topic author has the option of allowing specific users to share with the topic author the responsibility of revising a topic structure's statements and rebuttals. In addition, the topic author may allow users the option of co-writing critiques. Thus, a critique may have two or more authors. The topic author can also allow one or more users to score the statements, critiques and rebuttals in a debate structure. These users can be specified in a whitelist of user and domain names. Such group topic revision, group critiquing, and group scoring facilitate debates among teams and can be a useful feature in classrooms, groups, organizations, and so on. For example, teams can be created and named, Defenders, Critics, and Evaluators. Defenders are those who can create/revise statements and create/revise rebuttals, Critics can create/revise critiques, and Evaluators can score. The topic author does not necessarily need to belong to any of these groups which allows a moderator or instructor to create a topic, create teams and let them debate. Following the same example, in a preferred embodiment, the Defenders, by default, are the topic owners and the Critics and Evaluators are open to all users. The presence of a specific group of Critics also allows the online debate application to inform those users when the topic is published and ready for their review.
In another preferred embodiment a user can post a critique to a statement only if that user has viewed at least one previous critique of that statement 81 . This requirement helps reduce unnecessary duplication of critiques. In another preferred embodiment all critiques are displayed when a user wishes to add a critique and is not required to read any critiques.
In a preferred embodiment, a user can add a topic structure 70 to a watchlist. This allows the user to return to that topic structure easily from any location in the online debate application software of the present invention. In another preferred embodiment, a user can tag an option to a topic structure that the user has placed on the watchlist. For example, one option may be to have the debate application software notify the user when the topic structure has been updated regardless of whether the user is participating in a debate on the topic.
In a preferred embodiment, a user can evaluate any statement 81 , critique 82 , or rebuttal 83 that the user did not create. This evaluation can be manifested by assigning a score to statement 81 . For example, critiques and rebuttals are scored by explicitly agreeing with a particular critique or rebuttal, disagreeing with the critique or rebuttal, or disagreeing with accompanying rationale. For example, a rationale or reason can be one of the following: generalization, “from authority,” red herring, “straw man,” “begs the question,” false analogy or personal attack. Several other rationales and reasons can also be available to the user or the user can create rationales ad hoc.
Thus, a user can score a statement by explicitly agreeing with the statement. Similarly, a user can score a statement by disagreeing with the statement, for example, by posting a new critique or agreeing with an existing critique. If a user agrees with a critique of a statement, the user has by implication disagreed with the statement and with the topic structure. However, a user cannot post a disagreement with the entire topic structure unless the user has agreed with or written a critique of a topic statement.
In a preferred embodiment, topics—manifested by topic structures—can be ranked. Ranking, also referred to as scoring, allows a user to quickly determine which statements in a topic structure, as opposed to critiques and rebuttals, have the highest number of disagreements or negatives. This can be shown in statement map 90 or topic layout 91 and allows users to focus on the more contentious points in a debate. A user can make a single critique which can devastate an argument and remain visible to all users regardless of how often the topic author revises her rebuttal in response to the single critique.
Ranking also assists new users in identifying topics that may be of interest to them. For instance, a user may want to participate or examine a topic that has many users (both in terms of percentages and numbers) agreeing with the point of the topic, which can be gleaned from a quick review of the topic's rank. A topic is ranked based on scores given to various components of its debate structures, namely, statements, critiques, and rebuttals. In a preferred embodiment, a topic is ranked based primarily on users agreement or disagreement with the topic. Logically, disagreement with a topic is caused by agreeing with critiques but the score of a rebuttal has no impact on an overall topic rank.
Users can disagree with critiques and rebuttals with options such as those mentioned earlier: generalization, “from authority,” red herring, “straw man,” “begs the question,” false analogy, personal attack, and others. The online debate application can create visual representations, such as graphs, that display these options for each critique and rebuttal. This allows users to clearly see the frequency of the various forms of disagreement others had with a particular critique or rebuttal. Critique ranking can also be used to order the presentation of critiques after a topic statement. For example, the critique with the highest number in agreement would appear first insuring that the most valid criticism of a topic statement as judged by those scoring is the first critique that a user would see following the topic statement.
While a topic author can revise the topic at any time, i.e., revise any statement within the topic structure, for example, add or delete topic statements, another user may make her own copy of the topic structure and revise it as she sees fit. She then owns the copy of the topic structure and can make new statements which other users can critique. In a preferred embodiment a copy of the topic structure includes a pointer back to die original topic structure so that users can see the origin of the material.
In a preferred embodiment, a user has the option of allowing another user to e-mail a formatted and ‘cleaned up’ URL and message regarding a topic structure to other users or individuals not using the application. A topic author or any other user can also create a hyperlink for any statement, critique or rebuttal, and send the link to other users. This enables a user to point other users directly to a specific response to a statement regardless of where the response resides; for example, whether it is in a history or whether it is the most recent response made in a debate structure. In another preferred embodiment, a particular user can conceal or collapse critiques by other users which the particular user believes clutters the debate, are unconstructive, or are simply chronically useless to the debate. These hidden critiques can still be viewed by other users.
Embodiments within the scope of the present invention may also include computer-readable media for carrying or having computer-executable instructions or data structures stored thereon. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program module means in the form of computer-executable instructions or data structures. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or combination thereof) to a computer, the computer properly views the connection as a computer-readable medium. Thus, any such connection is properly termed a computer-readable medium. Combinations of the above should also be included within the scope of the computer-readable media.
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The patent describes and claims methods and systems for hosting and administering a forum for adversarial discussion. The invention consists of the underlying concepts, rules, and features of a distributed software program for conducting online debates. These concepts, rules, and features create a forum and an online tool for enforcing focused, rational debate. Rules are enforced that prevent digression, noise over content, and non-substantive, unproductive participation. In one embodiment, the method of hosting a debate includes the step of accepting a first statement from a topic author. By submitting the first statement, the topic author is creating a topic structure, which represents the basis for a debate on a particular topic. The topic author adds statements to the topic structure that can support the first statement and can proceed to build the topic structure which is comprised of debate structures containing specific statements and related data, such as critiques, rebuttals, a revision history, and scores. Other debate participants can react to the statements in a topic structure by submitting critiques of statements and can rank statements and rebuttals. A topic structure is manifested by at least two visual components: a statement map and a topic layout. These features of the present invention provide a context for the debate, whereby the ability to revise statements, critiques and rebuttals prevents digression allows for a rational debate in a controlled forum.
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FIELD OF THE INVENTION
The present invention relates to skid-steer loaders and more particularly to an operator enclosure which can be swingably moved between its operative position and a rearwardly raised position to permit access to loader hydraulic, electrical and drive components for maintenance purposes.
BACKGROUND OF THE INVENTION
Skid-steer loaders are small work vehicles equipped with hydraulically powered lift arms that jointly carry a bucket or other working tool at their forward ends. An operator station or enclosure is carried in the middle portion of the loader.
Beneath the operator enclosure are housed loader components such as a hydrostatic transmission, steering linkages, hydraulic lines and valves for powering the lift arms, bucket, and auxiliary functions, hydraulic lines for the wheel motor drives and miscellaneous electrical wiring harnesses and connections. To permit access to these loader components for maintenance and related services, the operator enclosure must be moved. Common methods of moving it include sliding it forward, pivotally swinging it forward, and pivotally swinging it rearwardly.
Since the lift arms of a skid-steer loader extend along its sides, they can block access to the components. Front access is therefore often preferred. When forwardly sliding or forwardly swinging operator enclosures are provided on loaders, front access is precluded and the lift arms must be raised to permit access from the sides of the loader. When the loader hydraulic power system is not operable, the arms cannot be easily raised and working access can become difficult. To overcome this problem, some skid-steer loaders have been equipped with rearwardly swinging enclosures.
It is often desirable to equip skid-steer loaders with lift arms that raise vertically so that the vertical height and forward reach of the bucket is maximized and it is easier to empty the loader bucket into a truck. When such lift arms are provided on a skid-steer loader, both the forward and rearward ends of the arms are mounted to raise vertically and move the bucket along a substantially vertical path. To facilitate vertical movement of the arms, their rear portions are pivotally connected to links that allow the rearward ends of the arms to raise vertically relative to the loader. These links are sometimes mounted on vertically raised frame structures on the loader to increase the vertical reach of the arms. Because the links also permit swinging movement of the arms, the arms can be extended forwardly when raised to improve the ability to empty a load over the sides of a dump truck.
Since the raised frame structures must support the lift arms as well as the bucket and its load, they are sometimes reinforced with one or more cross members. Further, the links which support the lift arms are often reinforced with one or more transversely extending cross members. Either or both of these cross members can provide an obstacle to swinging an operator enclosure rearwardly and can severely restrict the degree to which it can swing upwardly and rearwardly. Accordingly, the available working area beneath the rearwardly raised operator enclosure, wherein maintenance on the vehicle components can be performed, can be restricted.
It would therefore be desirable to provide a skid-steer loader having an operator enclosure which can be moved upwardly and rearwardly to access the working components from the front of the vehicle. It would also be desirable to provide such an operator enclosure on a loader having links between the loader and rear end portions of the lift arms to provide vertically lifting arms.
It would further be desirable to provide support posts for mounting the lift arm links to enable the arms to raise above the loader frame and maximize their vertical height and forward reach for dumping loads over the sides of a dump truck.
Also, it would be desirable to provide a reinforcing cross member to stabilize the links and posts as well as permit the use of less substantial support structures for the posts.
It would further be desirable to mount the operator enclosure such that the bottom and back portions of the enclosure raise up and above the access or working area, and are not restricted in their upwardly and rearwardly movement by the cross member.
It would also be desirable to minimize the bulk of the operator enclosure, particularly the size of the frame components required in its construction.
And it would be desirable to provide a power means for raising the operator enclosure that will function when the loader's hydraulic or electrical power systems is down as well as one which is releasably lockable to secure the enclosure in its raised position.
SUMMARY OF THE INVENTION
Accordingly, there is provided a skid-steer loader with vertically lifting arms and an operator enclosure that can be swung upwardly and rearwardly even when the loader experiences a complete hydraulic and electrical power failure.
The rear of the operator enclosure is pivotally connected to the top portions of upstanding support posts, providing high pivot points for upwardly swinging movement of the enclosure and the posts serve as structural frame members for the enclosure during operation. The pivot structures for the operator enclosure are located at its upper rear portion to permit the bottom and back sections of the enclosure to be lifted substantially above the loader components and provide a sufficient work area for service. The links which provide vertical lift capability to the lift arms are also pivotally mounted on the support posts to maximize their vertical lift and forward reach and simplify the design. A reinforcing cross member is provided between the posts and connecting ends of the lift links to stabilize the posts and links and minimize the post size required.
The pivot structures for the enclosure are located adjacent to and slightly forward of the cross member to eliminate interference between the enclosure and cross member when the enclosure is swung upwardly and rearwardly for access to the vehicle components. The cross member and pivot structures for both the enclosure and lift links are located near the top of the support posts to improve rear window visibility. Gas cylinders are provided to assist in raising the enclosure and include releasable locking mechanisms so that it can be safely secured in a raised position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevated front right perspective view of a skid-steer loader with a swinging operator enclosure in its operative position.
FIG. 2 is an elevated rear left perspective view of a skid-steer loader with the enclosure in its operative position.
FIG. 3 is an elevated front right perspective view of the loader with the enclosure in its raised position.
FIG. 4 is a schematic side view of a loader with its enclosure in its raised position and illustrating in phantom the enclosure in its operative position
FIG. 5 is an enlarged and elevated rear left perspective view of the pivot structures which swingably support the enclosure and upper link members with the loader posts.
FIG. 6 is a view taken along lines 6--6 of FIG. 5.
FIG. 7 is an enlarged schematic perspective view of the control handles and their cam activated support linkages.
FIG. 8 is a schematic side view of the gas cylinder in its compressed state.
FIG. 9 is a schematic side view of the gas cylinder in its extended and locked state.
FIG. 10 is an enlarged and elevated rear perspective view of the fastening structure used to secure the operator enclosure to the loader frame during operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Looking first to FIGS. 1 and 2, there is illustrated a skid-steer loader 10 having vertically lifting arms 12 and a rearwardly swinging operator enclosure 14. The loader frame 16 supports a rear mounted engine 18 and front and rear wheels 20 and 22. As is common in skid-steer loaders, the rear wheels 22 are independently driven and coupled with their respective front wheels 20 by chain drives (unshown). The enclosure 14 is carried in the central portion of the frame 16, between the lift arms 12.
The lift arms 12 are adapted to support a bucket or similar working tool 24 at their forward ends and are mounted on the frame 16 to raise vertically. To enable such movement, each arm 12 is pivotally connected to a first link member 26 which extends between the frame 16 and a lower rear portion 28 of the arm 12. Second or upper link members 30, comprised of arc-shaped structures, are pivotally connected between the top rear portion 32 of each arm 12 and one of the upstanding left and right posts 34 carried at the rear portion of the loader frame 16. Hydraulic cylinders 36 are provided between the frame 16 and each arm 12 for raising and lowering it.
The operator enclosure 14, which is best shown in FIGS. 1, 2, 3 and 4, includes a base 38 having a floor 40 with integral side and rear walls 42, 44, tubular side members 46 extending from the side walls 42 and to the post supports 34, a roof 48 with a forwardly extending tubular frame 50 and protective wire sides 52. The upstanding posts 34 at the rear of the loader 10 provide additional rollover protective support structure for the enclosure 14. The enclosure 14 further includes a seat 54 mounted on the base 38 and miscellaneous gauges mounted within it. Left and right wheel control levers 56 and 58 project upwardly from the frame 16 at the forward edge of the enclosure 14. Fasteners, taking the form of bolts 60 and nuts 61, secure each side of the enclosure 14 to the frame 16 and retain it in its operative position, see FIGS. 3 and 10.
In FIGS. 3, and 4, the loader 10 is shown with the enclosure 14 in its upwardly and rearwardly raised position, providing access to the various loader components housed beneath it. They include the hydrostatic transmission 62, steering linkages that interconnect the control levers 56 and the hydrostatic transmission 62, hydraulic valves 64 and attached lines for powering the lift arms 12, bucket 24 and auxiliary loader functions, hydraulic lines for the wheel motor drives and miscellaneous electrical wiring harnesses and connectors.
As shown in FIGS. 3, 4, and 5, the enclosure 14 is mounted to swing upwardly and rearwardly about left and right pivot structures 66 carried at the top ends of the posts 34. Each pivot structure 66 includes an ear 68 attached to and extending from one of the tubular side members 46. Bolts 70 are used to secure the ears 68 between the inner and outer walls 72 and 74 of the respective posts 34. Each bolt 70 is provided with threads at one end and nuts 76 are used to lock the bolts 70 to the inside and outside walls 72 and 74 of the posts 34.
Extending between the upper ends of the posts 34 and just behind the pivot structures 66 is a reinforcing cross member 78, see FIG. 5, which in the preferred embodiment takes the form of a C-shaped member with cap 79 fastened thereto. The opposite ends of the cross member 78 abut and are welded at 80 to the inner walls 72 of the posts 34, see FIG. 6. The cross member 80 not only reinforces the posts 34, but stabilizes the upper ends of the links 30, thereby eliminating the need for a cross member between the upper ends of the links 30.
Pivotal interconnections 82 swingably secure the upper links 30 with the posts 34. As is best illustrated in FIGS. 5 and 6, these interconnections 82 are comprised of first bosses 84 attached to the ends of the upper links 30, second bosses 86 secured to the posts 34, tapered link pins 88 receivable through bosses 84 and seated within the second bosses 86, and bolts 90 used to secure the tapered link pins 88 within the second bosses 86. The bolts 90 are threaded and received in internal threads 92 provided within the bore of each second boss 86 to swingably mount the upper links 30 to the posts 34.
With the cross member 78, pivot structures 66 and pivotal interconnections 82 all provided near the top of the posts 34, a large rear window is provided for the enclosure 14, thereby improving rearward visibility.
In operation the loader 10 would be utilized as would similar loaders equipped with vertically lifting arms 12, that is, to enable material to be lifted high and emptied over the side of a truck for disposal. Should the loader 10 encounter mechanical problems or need maintenance requiring access to the vehicle components housed beneath the operator enclosure 14, the operator can easily swing the enclosure 14 upwardly and rearwardly to the position illustrated in FIG. 3.
To swing the enclosure 14 upwardly, the operator would dismount the loader 10 and remove the nuts 61 from bolts 60, which fastened to the loader frame 16. Then standing in front of the loader 10, he would lift on the side walls 42 of the enclosure 14. As he lifted, gas cylinders 94 provided at each side of the enclosure 14 would begin to extend and assist in raising the enclosure upwardly and rearwardly about its pivotal structures 66 carried on the posts 34. As the enclosure 14 raises, the control levers 56 shift forwardly to provide clearance for the swinging enclosure floor 40 (See FIGS. 3 and 7). Shifting movement of the control levers 56, 58 is effected through interaction between the bottom surface of the floor 40 and the cams 96 carried on control lever pivot shafts 98. This feature is the subject of a related U.S. patent application Ser. No. 08/953,560, filed on Oct. 17, 1997, and its disclosure, particularly pages 2-5, is hereby incorporated by reference and made a part of this disclosure. When the enclosure 14 has been raised to its uppermost position, as illustrated in FIG. 3, a locking means carried on one gas cylinder 94 is actuated to support the enclosure 14 in the raised position. The locking means, which is best shown in FIGS. 8 and 9, is provided within one of the gas cylinders 94. It includes a seat 100 mounted in the bottom of the lower sleeve 102 which carries the cylinder rod 104 at an angle relative to the lower sleeve 102. As the cylinder 94 extends from the position illustrated in FIG. 8 to the position shown in FIG. 9, the seat 100 urges the lower sleeve 102 out of alignment with the upper sleeve 106. When the cylinder 94 is fully extended, the lower sleeve 102 shifts to the position illustrated in FIG. 9, whereby its top edge 108 slides beneath the lower edge 110 of the upper sleeve 106. With the cylinder sleeves 102 and 106 misaligned and their respective end surfaces 108 and 110 in abutment, as shown in FIG. 9, the cylinder 94 cannot retract and is "locked" in place, retaining the enclosure 14 in its raised position. One locking cylinder found acceptable for this use is the model ECV4SC500555S4D from Camloc (UK) Ltd., Fairchild Fastener Group.
With the enclosure 14 raised, access to the loader components housed beneath the enclosure 14 is easily gained from the front of the loader 10. Additional access would also be possible from the sides of the loader 10 if there has not been an electrical and/or hydraulic failure that would prevent the lift arms from being raised.
After the maintenance or repairs have been completed, the enclosure 14 can easily be returned to the operative position and secured in place. To return it to an operative position, the cylinder locking means would be disengaged to allow the cylinders 94 to retract. This is accomplished by urging the cylinder sleeve 102 with the locking mechanism inwardly, against the bias of the seat 100, to align the upper and lower sleeves 106 and 102. Once aligned, the enclosure 14 is urged downwardly to compress the cylinders 94. As the enclosure 14 swings downwardly about its pivotal connections 66 with the posts 34, the floor 40 comes into contact with the cams 96, swinging the control levers 56, 58 into the upright position illustrated in FIG. 1. At the same time, the L-shaped brackets 112 secured to the frames 46 of the enclosure 14 swing down, permitting the openings 114 to be positioned around their respective bolts 60. The nuts 61 can then be placed on the bolts 60 to secure the enclosure 14 with the loader frame 16, thereby preventing upward movement of the enclosure 14 during operation. Resilient pads 116, provided around the bolts 60, serve to cushion relative movement between the enclosure 14 and frame 16.
With the upperward and rearwardly swinging operator enclosure, access to the components from the front of the loader vehicle is easily facilitated. This advantage can be desirable particularly when the loader has encountered a complete electrical and hydraulic failure which would prevent the lift arms from being easily raised or moved so that access from the sides of the loader could be performed.
Through locating the pivotal structures for the enclosure and lift arms high and on common support posts, the lift arms are able to reach vertically and forwardly to dump loads over the side of trucks for disposal, the enclosure can be raised substantially above the loader components, rear visibility is improved and fewer and less substantial structural components are required in constructing the loader.
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A rearwardly swinging operator enclosure is provided for a skid-steer loader having vertical lift arms. The enclosure, as well as the links coupling the lift arms to the loader are both pivotally mounted high on laterally spaced apart support posts carried at the rear of the enclosure. The raised pivotal mountings permit the enclosure to swing rearwardly and high above the loader components housed beneath the enclosure to allow maintenance activities to be conveniently carried out from the front of the loader. The raised pivotal mountings further permit the use of a cross member to reinforce both the support posts and lift arm links and yet avoid interference with swinging movement of the enclosure or lift links. With the cross member positioned near the top of the support posts, rear visibility is enhanced.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to an apparatus designed to assist a person with focal limb weakness, in particular those having a foot-drop type of disability with weakness or paralysis of dorsiflexion and eversion of the foot and extension of the toes. In particular the present foot drop aid is quickly and easily attached on the foot or shoe and onto the leg of the patient employing reliable, long use coil springs for the motive force.
[0003] Persons who have sustained a stroke, peripheral nerve injury, or suffer from diseases such as multiple sclerosis, et al., generally incur certain neuromuscular pathological conditions because of damage to the nerves which innervate the muscles involved. This damage occurs centrally in the brain and/or spinal cord, or locally to peripheral nerves, such as those found in the leg, resulting in paralysis or partial paralysis in varying degrees of severity to different parts of the body. Generally, the distal joints are proportionately weaker than the more proximal joints (proximal meaning close to the midpoint of the body). Foot-drop is characterized in that a person, who otherwise has sufficient muscular control to move his foot relative to his ankle in plantar flexion (a downward push off motion), lacks sufficient muscular control to subsequently effect a dorsiflexion motion to raise the foot back up for the next step. Also usually evidenced in persons having foot-drop is the diminished capacity to move the foot in what is termed eversion, or rotating the outer part of the foot in an upward manner.
[0004] Paralysis, in any degree, of the ankle and the mid-tarsal joint (just distal to the ankle), and the resultant foot-drop, present greater problems because of the independent movement required of them in walking. Ankle motions are dorsi-flexion (up) and plantar flexion (down), and mid-tarsal joint motions are inversion (inward turning) and eversion (outside edge of the foot turned up). Paralysis or partial paralysis for any of the reasons described herein usually impair the ankle and mid-tarsal joint such that dorsi-flexion and eversion are weaker than plantar flexion and inversion. Where a foot-drop problem is present, walking without the assistance of a brace or support will result in the front (toe) portion of the foot dragging along the ground after the leg and foot have completed the plantar flexion portion of the gait. Therefore, a need exists for a foot-assist mechanism which selectively provides dorsiflexion support for the foot by compensating for the weakened muscles while allowing the functioning flexor muscles or portions thereof to continue to contract to their fullest extent.
[0005] 2. Related Art
[0006] A number of devices have been provided to date to alleviate foot-drop which includes short-leg braces having metal uprights, metal stirrups, molded calf cups, etc. Rigid devices such as U.S. Pat. No. 3,986,501 to Schad are static in nature in that they maintain the foot in a relatively fixed position in relation to the leg (which is never greater than 90 degree.) at all times so that the entire lower leg from calf to toes moves en masse as a rigid structure being propelled and supported by the person's knee, hip and spine, thereby producing an awkward gait and immobilize working muscles to a degree, contributing to disuse atrophy or earlier degeneration.
[0007] More recently several devices which will aid the functioning of those muscles directly effected by a disabling condition, such as those described hereinbefore, but which allows full range of motion of the foot and usage of those muscles either not effected or only partially effected, such as described in U.S. Pat. Nos. 4,817,589; 5,257,959; 6,602,217 and 7,354,413 have employed elastomeric components for foot lift. The '959, '217 and '413 devices required attachment directly on the foot while the '217 device requires special attachment means on a shoe.
[0008] It is an advantage of the present invention as it relates to a foot lit apparatus that in addition to allowing full range of motion of the foot and usage of those muscles either not effected or only partially effected, that it provides a more reliable and longer use foot lift component. It is a further advantage of the present foot lift device that is easily attached by the patient directly to the foot for use with a shoe or directly onto any shoe worn by the patient.
[0009] Finally, it is intended to provide a foot-drop assist device which is lightweight, relatively inconspicuous, easy to use, and very inexpensive to make and maintain.
[0010] A person having a foot-drop type disability wearing the present foot lift apparatus can use relatively unaffected muscles without hindrance or discomfort to their fullest extent, e.g., by extending the foot (plantar flexion), while at the same time enjoying the benefits of a convenient selectively-active assist mechanism which will help them to walk normally. The present foot lift device is particularly useful to stroke victims since the muscles used to raise the foot (dorsi-flexion) and turn it outward (eversion), both of which are required in walking, are nearly always affected by those persons suffering residual paralysis as a result of a stroke.
SUMMARY OF THE INVENTION
[0011] In accordance with the present invention, there is provided an apparatus for assisting a person having an orthotic weakness comprising a first belt having two ends, a hooks/loops component on a first side at a first end of said first belt and a cooperating hooks/loops component on a second side of said first belt distal to said first end; a pair of first brackets spaced apart and attached to said first side of said first belt, a pair of coil springs attached to one each of said first brackets; a second belt having two ends, a hooks/loops component on a first side of said second belt at a first end and a cooperating hooks/loops component on a second side of said second belt distal to said first end; a pair of second brackets spaced apart and attached to one side of said second belt; and two adjustable straps attached one each to said springs and attached one each to said second brackets in operable alignment with one each said springs.
[0012] One embodiment of the present invention is an apparatus for a foot-drop type disability which includes an ankle attachment member, a pair of coil springs attached to the ankle attachment member, a shoe belt for attaching around the wearer's shoe or foot forward of the ball of the foot and a pair of adjustable, releaseable straps affixed from a shoe belt having attachment means to one each of the coil springs. When the apparatus is in use, the ankle belt is attached at or immediately above the ankle, the coil spring contracts to raise the wearer's foot during the time period that the wearer is not forcibly extending the strap by downwardly extending his or her foot. In its preferred embodiment, the present apparatus is extremely easy to put in use since the ankle belt and the shoe belt are attached around the ankle and the shoe by adjustable, releaseable straps, such as hooks and loops (VELCO™) and the two belts are connected by engagement of the two straps. The present foot-drop assist apparatus therapeutically aids progressively debilitating diseases such as multiple sclerosis by permitting the viable muscles to remain fully active until they are directly effected by the damaging disease.
[0013] For a better understanding of the present invention, together with other and further advantages, reference is made to the following description, taken in conjunction with the accompanying drawings. Like reference characters designate like parts in the drawings. In some instance there may be reversal of parts that result in the same functionality.
[0014] The present apparatus is designed for functionality, easy of manufacturing with readily available, inexpensive materials and having minimum obtrusive appearance obtained by its low positioning on the leg of the user. By leaving the ankle belt and the shoe belt connect, the simple two step attachment procedure allows the user to attach the apparatus at night with or without shoes and with reduced light.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a front perspective view of one embodiment of a foot drop aid according the present invention.
[0016] FIG. 2 is a side view of the foot drop aid of FIG. 1 showing hook material on one side of the ankle belt and loop material on the other side which cooperate to attach the ankle around the ankle of the user.
[0017] FIG. 3 is perspective view of the FIG. 1 embodiment as viewed from the outside of a person's right leg shown in conjunction with a shoe on the person's foot.
[0018] FIG. 4 is bottom view of a shoe showing a position of the shoe strap passing around the bottom of the shoe forward of the ball of the foot when the foot drop aid is in use as shown in FIGS. 3 and 5 .
[0019] FIG. 5 is perspective view of an alternative version of a foot drop aid embodiment as viewed from the outside of a person's right leg shown in conjunction with a shoe on the person's foot.
DESCRIPTION OF THE INVENTION
[0020] The device may be viewed as having two parts. 1) An ankle cuff with soft foam inside, two springs, each spring with an adjusting strap made up of a hook section and a loop section. 2) A foot strap with a hook section and a cooperating loop section fastener and two buckles to engage the one each of the adjusting straps on either side of the foot. Once adjusted, by moving the length of the adjusting straps equally, the user can walk with no fear of tripping.
[0021] In use the ankle belt 1 is position on the user's leg, inverted to the display in FIG. 1 , such that the edge 31 is the lower edge of the ankle belt. The display in this manner provides a cleaner presentation of the components without overlaying them on the ankle belt.
[0022] FIGS. 1 and 2 show the foot drop aid (FDA). The FDA comprises an ankle belt or cuff 1 , which made of a stout cloth, such as denim, of two sheets or single sheet folded over to form a pocket to provide the inner sheet 2 and the outer sheet 3 . A stiffener 4 shown by phantom lines is smaller than the denim sheets and positioned between the sheets, to extend over a portion of the center area of the belt to provide a semirigid structure in order to maintain the cloth as upright when positioned on the leg of a user. Although not shown, a single piece of cloth can be used as the belt with the stiffener attached as by sewing onto the belt with a foam pad attached over the stiffener. In use about the ankle of a user the longitude of the belt 1 is greater than the vertical height. The cloth has longitudinal flexibility, is comfortable and less likely to cause irritation on the leg and prevent the stiffener from contact with the skin. The stiffener may be wire or plastic mesh. To further protect the user a foam rubber sheet 5 is adhered to inner sheet 2 between the users leg and the cloth of the belt when the FDA is in use.
[0023] A hooks and loops attachment system (VELCO®) is provided on the belt 1 to hold it in place around the leg by attaching a hooks or loops component 6 at one end of the belt on inner sheet 2 and a cooperating component 7 (hooks or loops) at the distal end of the belt on outer sheet 3 .
[0024] A pair of cloth tabs 8 and are spaced apart and attached adjacent to the upper edge 32 to each hold brackets 10 and 11 , respectively, such as plastic or metal triangles or rings to which are attached to one end of coil springs 12 and 13 , respectively. The distal end of each coil spring is attached by connectors 18 and 19 , respectively to a pair of straps 21 and 20 each having cooperating hook and loop surfaces. The straps each pass through buckle 22 or 23 , respectively and are releaseably engaged by the hooks and loops to thereby adjust the distance of the belt 24 from the ankle belt 1 . Each buckle 22 and 23 is affixed by a strap to opposite ends of belt 24 by tabs 29 and 28 , respectively. Tabs 28 and 29 are cloth sown onto cloth belt 24 and spaced apart to be on either side of the shoe or foot in use. At distal ends of the shoe/foot belt 24 , cooperating hooks/loops 25 / 26 are positioned on opposite sides of the belt to the engage the belt around the shoe or foot such that the engagement of 25 and 26 is on the top of the shoe/foot and the continuous portion 27 of the belt 24 is on the bottom (see FIG. 4 ).
[0025] An alternative means for connecting the ankle belt 1 to the belt 24 is shown in FIG. 5 , where mechanical quick connect/disconnect latches 17 and 16 are inserted with straps 15 and 14 between buckle 22 and 23 and coil springs 13 and 12 , respectively.
[0026] The major advantage of the present FDA compared to prior similar devices, is the spring action. It has been found that the elastomeric materials, lose the repeatability of the elastomeric lift very quickly thus become unuseable. In walking, the toe is only slightly elevated above the surface, and the lift must always reliably be the same or the user will trip and fall. As the leg goes forward, while walking, the heel contacts the ground, then the ankle bends so that the ball of the foot reaches the floor. This angle between the bottom of the foot and the shin is greater than 90 degrees and the springs stretch. As the step progresses to the rear (i.e., the user walks forward), the ankle again bends so that the heel rises with the ball of the foot still on the floor, with the angle less than 90 degrees at which point the springs relax. As the foot moves forward, the springs lift the foot to the proper position without dragging the toe and completing the step. The springs reliably repeat the mechanical action without any observed decline in the functionality over a sustained test period.
[0027] In order to fit the FDA on a user, as shown in FIGS. 3 and 5 the ankle belt is placed around the lower leg just above ankle bone, preferably over a sock or hose, since there may be repetitions of the mechanical process of foot lifting with a concurrent stress on the user's leg 50 . The foam 5 goes against the ankle on the back side of the leg to provide further protection for the leg.
[0028] The ankle belt should rest just above the ankle bones (not shown) that stick out on either side of the foot 51 . With the ankle belt securely fastened to the ankle, the belt is rotated, as required, about the ankle so that the springs are positioned on the left and right sides of the ankle.
[0029] The foot strap 24 is placed under the shoe 52 . The foot strap, which may be a flexible ribbon like material, is positioned slightly forward of the ball (not shown) of the foot. The cooperating hooks and loops 25 and 26 on ends of foot strap, are crossed, each making a chevron over the top of the shoe or foot. Where the straps intersect, the sides of the shoe adjust them so that they conform to the shoe shape. This gives maximum comfort and creates a funnel that the shoe fits in when the strap is pulled back toward the ankle. Doing this, will also prevent a loop (not shown) forming on the bottom 53 of the sole that can catch on floor objects.
[0030] To adjust the foot lift, the spring straps 20 and 21 are passed through the buckles 22 and 23 respectively ( FIG. 3 ) on the foot strap 24 . The leg with the FDA is lifted so that the foot is off the floor. The intention is to adjust both straps at the same time so that the foot is held 90 degrees to the shin (not shown). The foot is now lifted and held in place by the extended springs. The FDA can be used on sandals, shoes with no heels or with moderate heels. Using a barefoot pad (not shown) under the foot lift can then be worn with covered bare feet, typically at night or around the home.
[0031] The toes of the foot will not drag on the floor. Should the toes be too low and drag on the floor or the foot strap drags on the floor due to a loop under the shoe, the straps should be readjusted until the springs hold the foot higher. The foot at the beginning and end of the step will flex, due to the springs, and still return to lift the foot. This is how the FDA allows for normal walking and requires no special adaptation be made to the shoe.
[0032] While there has been described what is presently believed to be the preferred embodiment of the invention, those skilled in the art will realize that changes and modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the true scope of the invention.
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An orthotic apparatus for assisting a person having an orthotic disability, such as foot drop, comprising an ankle belt component and a shoe/foot belt component connected by a pair of coil springs which are adjustably and releaseably attached between the belts. The foot at the beginning and end of the step will flex, due to the springs, and still return to lift the foot, which allows for normal walking and requires no special adaptation to the shoe.
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This application is a continuation of U.S. Ser. No. 09/962,794, filed Sep. 24, 2001 now abandoned, which is a continuation of International Patent Application No. PCT/US00/09390, filed Apr. 5, 2000 and published in English as International Publication No. WO 00/59683, which claims the benefit of U.S. patent application Ser. No. 60/127,754, filed Apr. 5, 1999; U.S. patent application Ser. No. 60/186,143, filed Mar. 1, 2000; U.S. patent application Ser. No. 60/186,142, filed Mar. 1, 2000; and U.S. patent application Ser. No. 60/191,286, filed Mar. 21, 2000, all of which are hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a disodium salt of a delivery agent, such as N-(5-chlorosalicyloyl)-8-aminocaprylic acid, N-(10-[2-hydroxybenzoyl]amino)decanoic acid, or N-(8-[2-hydroxybenzoyl]amino)caprylic acid, an ethanol solvate of the disodium salt, and a monohydrate of the disodium salt for delivering active agents and methods of preparing the same.
BACKGROUND OF THE INVENTION
U.S. Pat. Nos. 5,773,647 and 5,866,536 disclose compositions for the oral delivery of active agents, such as heparin and calcitonin, with modified amino acids, such as N-(5-chlorosalicyloyl)-8-aminocaprylic acid (5-CNAC), N-(10-[2-hydroxybenzoyl]amino)decanoic acid (SNAD), and N-(8-[2-hydroxybenzoyl]amino)caprylic acid (SNAC). Many current commercial formulations containing an active agent, such as heparin and calcitonin, are delivered by routes other than the oral route. Formulations delivered orally are typically easier to administer than by other routes and improve patient compliance.
There is a need for improved pharmaceutical formulations for orally administering active agents, such as heparin and calcitonin.
SUMMARY OF THE INVENTION
The inventors have discovered that the disodium salt of certain delivery agents has surprisingly greater efficacy for delivering active agents than the corresponding monosodium salt. Furthermore, the inventors have discovered that the disodium salts of these delivery agents form solvates with ethanol and hydrates with water. The delivery agents have the formula
wherein
R 1 , R 2 , R 3 , and R 4 are independently hydrogen, —OH, —NR 6 R 7 , halogen, C 1 -C 4 alkyl, or C 1 -C 4 alkoxy;
R 5 is a substitued or unsubstituted C 2 -C 16 alkylene, substituted or unsubstituted C 2 -C 16 alkenylene, substituted or unsubstituted C 1 -C 12 alkyl(arylene), or substituted or unsubstituted aryl(C 1 -C 12 alkylene); and
R 6 and R 7 are independently hydrogen, oxygen, or C 1 -C 4 alky. The hydrates and solvates of the present invention also have surprisingly greater efficacy for delivering active agents, such as heparin and calcitonin, than their corresponding monosodium salts and free acids.
The present invention provides an alcohol solvate, such as methanol, ethanol, propanol, propylene glycol, and other hydroxylic solvates, of a disodium salt of a delivery agent of the formula above. According to one preferred embodiment, the alcohol solvate is ethanol solvate. The invention also provides a hydrate, such as a monohydrate, of a disodium salt of a delivery agent of the formula above. Preferred delivery agents include, but are not limited to, N-(5-chlorosalicyloyl)-8-aminocaprylic acid (5-CNAC), N-(10-[2-hydroxybenzoyl]amino)decanoic acid (SNAD), N-(8-[2-hydroxybenzoyl]amino)caprylic acid (SNAC), 8-(N-2-hydroxy-4-methoxybenzoyl)aminocaprylic acid (as shown as compound 67 in U.S. Pat. No. 5,773,647), and N-(9-(2-hydroxybenzoyl)aminononanic acid (or 9-salicyloylaminononanoic acid) (as shown as compound 35 in U.S. Pat. No. 5,773,647).
The present invention also provides a method of preparing the disodium salt of the present invention by drying the ethanol solvate of the present invention. According to a preferred embodiment, the ethanol solvate is prepared by the method described below.
Another embodiment of the invention is a method of preparing the ethanol solvate of the present invention. The method comprises dissolving a delivery agent of the formula above in ethanol to form a delivery agent/ethanol solution; (b) reacting the delivery agent/ethanol solution with a molar excess of a sodium containing salt to form the ethanol solvate.
Yet another embodiment of the invention is a method of preparing the hydrate of the present invention. The method comprises (a) obtaining an ethanol solvate of the disodium salt of the delivery agent; (b) drying the solvate to form an anhydrous disodium salt; and (c) hydrating the anhydrous disodium salt to form the hydrate.
Yet another embodiment of the present invention is a composition comprising a disodium salt of the delivery agent.
Yet another embodiment of the invention is a composition comprising at least one disodium salt, ethanol solvate, or hydrate of the present invention and at least one active agent. Preferred active agents include, but are not limited to, heparin and calcitonin. The composition may be formulated into a dosage unit form, such as an oral dosage unit form.
Yet another embodiment of the present invention is a method for administering an active agent to an animal in need thereof comprising administering to the animal the composition of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The term “substituted” as used herein includes, but is not limited to, substitution with any one or any combination of the following substituents: halogens, hydroxide, C 1 -C 4 alkyl, and C 1 -C 4 alkoxy.
The terms “alkyl”, “alkoxy”, “alkylene”, “alkenylene”, “alkyl(arylene)”, and “aryl(alkylene)” include, but are not limited to, linear and branched alkyl, alkoxy, alkylene, alkenylene, alkyl(arylene), and aryl(alkylene) groups, respectively.
Disodium Salt
The disodium salt may be prepared from the ethanol solvate by evaporating or drying the ethanol by methods known in the art to form the anhydrous disodium salt. Generally, drying is performed at a temperature of from about 80 to about 120, preferably from about 85 to about 90, and most preferably at about 85° C. Typically, the drying step is performed at a pressure of 26″ Hg or greater. The anhydrous disodium salt generally contains less than about 5% by weight of ethanol and preferably less than about 2% by weight of ethanol, based upon 100% total weight of anhydrous disodium salt.
The disodium salt of the delivery agent may also be prepared by making a slurry of the delivery agent in water and adding two molar equivalents of aqueous sodium hydroxide, sodium alkoxide, or the like. Suitable sodium alkoxides include, but are not limited to, sodium methoxide, sodium ethoxide, and combinations thereof.
Yet another method of preparing the disodium salt is by reacting the delivery agent with one molar equivalent of sodium hydroxide to form a monosodium salt of the delivery agent and then adding an additional one molar equivalent of sodium hydroxide to yield the disodium salt.
The disodium salt can be isolated as a solid by concentrating the solution containing the disodium salt to a thick paste by vacuum distillation. This paste may be dried in a vacuum oven to obtain the disodium salt of the delivery agent as a solid. The solid can also be isolated by spray drying an aqueous solution of the disodium salt.
The delivery agent may be prepared by methods known in the art, such as those described in U.S. Pat. Nos. 5,773,647 and 5,866,536, respectively.
Another aspect of the invention is a composition comprising at least about 20% by weight and preferably at least about 60% by weight of the disodium salt of the delivery agent, based upon 100% total weight of the delivery agent and salts thereof in the composition. According to one embodiment, the composition comprises at least about 10, 30, 40, 50, 70, or 80% by weight of the disodium salt of the delivery agent, based upon 100% total weight of the delivery agent and salts thereof in the composition. More preferably, the composition comprises at least about 90% by weight of the disodium salt of the delivery agent, based upon 100% total weight of the delivery agent and salts thereof in the composition.
Most preferably, the composition comprises substantially pure disodium salt of the delivery agent. The term “substantially pure” as used herein means that less than about 4% and preferably less than about 2% by weight of the delivery agent in the composition is not a disodium salt, based upon 100% total weight of the delivery agent and salts thereof in the composition.
Ethanol Solvate
The term “ethanol solvate” as used herein includes, but is not limited to, a molecular or ionic complex of molecules or ions of ethanol solvent with molecules or ions of the disodium salt of the delivery agent. Typically, the ethanol solvate contains about one ethanol molecule or ion for every molecule of disodium salt of the delivery agent.
The ethanol solvate of the disodium salt of the delivery agent may be prepared as follows. The delivery agent is dissolved in ethanol. Typically, each gram of delivery agent is dissolved in from about 1 to about 50 mL of ethanol and preferably from about 2 to about 10 mL of ethanol. The delivery agent/ethanol solution is then reacted with a molar excess of a sodium containing salt, such as a monosodium containing salt, relative to the delivery agent, i.e., for every mole of delivery agent there is more than one mole of sodium cations. This reaction yields the ethanol solvate. Suitable monosodium containing salts include, but are not limited to, sodium hydroxide; sodium alkoxides, such as sodium methoxide and sodium ethoxide; and any combination of any of the foregoing. Preferably, at least about two molar equivalents of the monosodium containing salt are added to the ethanol solution, i.e., for every mole of delivery agent there is at least about two moles of sodium cations. Generally, the reaction is performed at a temperature at or below the reflux temperature of the mixture, such as at ambient temperature.
The ethanol solvate may then be recovered by methods known in the art. For example, the slurry resulting from the addition of sodium hydroxide to the delivery agent/ethanol solution may be concentrated by atmospheric distillation. The concentrated slurry may then be cooled and the solid product recovered by filtration. The filter cake, i.e., the filtrate, may be vacuum dried to obtain the ethanol solvate.
Hydrate
The term “hydrate” as used herein includes, but is not limited to, (i) a substance containing water combined in the molecular form and (ii) a crystalline substance containing one or more molecules of water of crystallization or a crystalline material containing free water. Compositions containing the hydrate of the disodium salt preferably contain at least about 80%, more preferably at least about 90%, and most preferably about 95% by weight of the monohydrate of the dissodium salt, based upon 100% total weight of hydrate of disodium salt in the composition. According to a preferred embodiment, the composition contains at least about 98% by weight of the monohydrate of the dissodium salt, based upon 100% total weight of hydrate of disodium salt in the composition.
The hydrate may be prepared by drying the ethanol solvate to form an anhydrous disodium salt as described above and hydrating the anhydrous disodium salt. Preferably, the monohydrate of the disodium salt is formed. Since the anhydrous disodium salt is very hygroscopic, the hydrate forms upon exposure to atmospheric moisture. Generally, the hydrating step is performed at from about ambient temperature to about 50° C. and in an environment having at least about 50% relative humidity. Preferably, the hydrating step is performed at from about ambient temperature to about 30° C. For example, the hydrating step may be performed at 40° C. and 75% relative humidity. Alternatively, the anhydrous disodium salt may be hydrated with steam.
According to one preferred embodiment, the drying and hydrating steps are performed in an oven. Preferably, the material is not exposed to the atmosphere until both steps are complete.
Disodium Salt, Ethanol Solvate, and Hydrate Compositions and Dosage Unit Forms
The invention also provides a composition, such as a pharmaceutical composition, comprising at least one of a disodium salt, ethanol solvate, or hydrate of the present invention and at least one active agent. The composition of the present invention typically contains a delivery effective amount of one or more disodium salts, ethanol solvates, and/or hydrates of the present invention, i.e., an amount of the disodium salt, ethanol solvate, and/or hydrate sufficient to deliver the active agent for the desired effect.
Active agents suitable for use in the present invention include biologically active agents and chemically active agents, including, but not limited to, pesticides, pharmacological agents, and therapeutic agents.
For example, biologically or chemically active agents suitable for use in the present invention include, but are not limited to, proteins; polypeptides; peptides; hormones; polysaccharides, and particularly mixtures of muco-polysaccharides; carbohydrates; lipids; other organic compounds; and particularly compounds which by themselves do not pass (or which pass only a fraction of the administered dose) through the gastro-intestinal mucosa and/or are susceptible to chemical cleavage by acids and enzymes in the gastro-intestinal tract; or any combination thereof.
Further examples include, but are not limited to, the following, including synthetic, natural or recombinant sources thereof: growth hormones, including human growth hormones (hGH), recombinant human growth hormones (rhGH), bovine growth hormones, and porcine growth hormones; growth hormone-releasing hormones; interferons, including α, β, and γ-interferon; interleukin-1; interleukin-2; insulin, including porcine, bovine, human, and human recombinant, optionally having counter ions including sodium, zinc, calcium and ammonium; insulin-like growth factor, including IGF-1; heparin, including unfractionated heparin, heparinoids, dermatans, chondroitins, low molecular weight heparin, very low molecular weight heparin and ultra low molecular weight heparin; calcitonin, including salmon, eel, porcine, and human; erythropoietin; atrial naturetic factor; antigens; monoclonal antibodies; somatostatin; protease inhibitors; adrenocorticotropin, gonadotropin releasing hormone; oxytocin; leutinizing-hormone-releasing-hormone; follicle stimulating hormone; glucocerebrosidase; thrombopoietin; filgrastim; prostaglandins; cyclosporin; vasopressin; cromolyn sodium (sodium or disodium chromoglycate); vancomycin; desferrioxamine (DFO); parathyroid hormone (PTH), including its fragments; antimicrobials, including anti-fungal agents; vitamins; analogs, fragments, mimetics or polyethylene glycol (PEG)-modified derivatives of these compounds; or any combination thereof. Preferred active agents include, but are not limited to, heparin and calcitonin.
The amount of active agent in the composition is an amount effective to accomplish the purpose intended. The amount in the composition is typically a pharmacologically, biologically, therapeutically, or chemically effective amount. However, the amount can be less than that amount when a plurality of the compositions are to be administered, i.e., the total effective amount can be administered in cumulative units. The amount of active agent can also be more than a pharmacologically, biologically, therapeutically, or chemically effective amount when the composition provides sustained release of the active agent. Such a composition typically has a sustained release coating which causes the composition to release a pharmacologically, biologically, therapeutically, or chemically effective amount of the active agent over a prolonged period of time.
The total amount of active agent to be used can be determined by methods known to those skilled in the art. However, because the compositions may deliver the active agent more efficiently than prior compositions, lesser amounts of the active agent than those used in prior dosage unit forms or delivery systems can be administered to the subject, while still achieving the same blood levels and/or therapeutic effects.
According to one preferred embodiment, the composition comprises a disodium salt of a delivery agent and calcitonin. Preferably, the delivery agent is 5-CNAC. Generally, the weight ratio of calcitonin to disodium salt of 5-CNAC varies depending on the animal to which the composition is to be administered. For example, for a composition which is to be administered to humans the weight ratio may range from about 1:300 to about 1:700 and is preferably about 1:500. For primates, the weight ratio generally ranges from about 1:100 to about 1:500.
The composition of the present invention may be in liquid or solid form. Preferably, compositions containing the disodium salt and/or hydrate of the present invention are in solid form. The composition may further comprise additives including, but not limited to, a pH adjuster, a preservative, a flavorant, a taste-masking agent, a fragrance, a humectant, a tonicifier, a colorant, a surfactant, a plasticizer, a lubricant, a dosing vehicle, a solubilizer, an excipient, a diluent, a disintegrant, or any combination of any of the foregoing. Suitable dosing vehicles include, but are not limited to, water, phosphate buffer, 1,2-propane diol, ethanol, olive oil, 25% aqueous propylene glycol, and any combination of any of the foregoing. Other additives include phosphate buffer salts, citric acid, glycols, and other dispersing agents. Stabilizing additives may be incorporated into the solution, preferably at a concentration ranging between about 0.1 and 20% (w/v).
The composition may also include one or more enzyme inhibitors, such as actinonin or epiactinonin and derivatives thereof. Other enzyme inhibitors include, but are not limited to, aprotinin (Trasylol) and Bowman-Birk inhibitor.
The composition of the present invention may be prepared by dry mixing or mixing in solution the disodium salt, hydrate, and/or ethanol solvate, active agent, and, optionally, additives. The mixture may be gently heated and/or inverted to aid in dispersing the components in solution.
The composition of the present invention may be formulated into a dosage unit form and in particular an oral dosage unit form, including, but not limited to, capsules, tablets, and particles, such as powders and sachets, by methods known in the art.
According to one preferred embodiment, the dosage unit form is a solid dosage unit form comprising a lyophilized mixture of at least one of a disodium salt, ethanol solvate, or hydrate of the present invention and at least one active agent.
The term “lyophilized mixture” includes, but is not limited to, mixtures prepared in dry form by rapid freezing and dehydration. Typically dehydration is performed while the mixture is frozen and under a vacuum. Lyophilized mixtures generally are substantially free of water and preferably contain less than 4% by weight of water, based upon 100% total weight of the mixture.
Such a solid dosage unit form may be prepared by (a) obtaining a solution comprising one or more delivery agents and one or more active agents, (b) lyophilizing the solution to obtain a lyophilized mixture, and (c) preparing a solid dosage unit form with the lyophilized mixture.
The delivery agent and active agent may be mixed in solution to form the solution in step (a). The solution may be lyophilized by any method known in the art. The lyophilized mixture may be incorporated into a dosage unit form by any method known in the art.
The composition and the dosage unit form of the present invention may be administered to deliver an active agent to any animal in need thereof including, but not limited to, birds, such as chickens; mammals, such as rodents, cows, pigs, dogs, cats, primates, and particularly humans; and insects. The composition and dosage unit form may be administered by the oral, intranasal, sublingual, intraduodenal, subcutaneous, buccal, intracolonic, rectal, vaginal, mucosal, pulmonary, transdermal, intradermal, parenteral, intravenous, intramuscular or ocular route. Preferably, the composition and dosage unit form are administered orally.
The following examples are intended to describe the present invention without limitation.
EXAMPLE 1
Preparation of N-(5-chlorosalicyloyl)-8-aminocaprylic acid (5-CNAC)
To a clean, dry, 200 gallon glass-lined reactor, 178 L of dry acetonitrile was added. The agitator was set to 100-125 rpm and the reactor contents were cooled to about 9° C. 74 kg of 5-chloro salicylamide, available from Polycarbon Industries of Leominster, Mass., was charged to the reactor and the charging port was closed. 47 L of dry pyridine was charged to the reactor. The resulting slurry was cooled to about 9° C. Cooling was applied to the reactor condenser and valve overheads were set for total reflux. Over 2 hours, 49.7 kg of ethylchloroformate was charged to the 200 gallon reactor while maintaining the batch temperature at about 14° C. Ethylchloroformate can contain 0.1% phosgene and is extremely reactive with water. The reaction is highly exothermic and requires the use of a process chiller to moderate reaction temperature.
The reactor contents were agitated for about 30 minutes at 10-14° C., once the ethylchloroformate addition was complete. The reactor contents were then heated to about 85° C. over about 25 minutes, collecting all distillate into a receiver. The reactor contents were held at 85-94° C. for approximately 6 hours, collecting all distilled material into a receiver. The reaction mixture was sampled and the conversion (>90%) monitored by HPLC. The conversion was found to be 99.9% after 6 hours. The reactor contents were cooled to about 19° C. over a one-hour period. 134 L of deionized water was charged to the reactor. A precipitate formed immediately. The reactor contents were cooled to about 5° C. and agitated for about 10.5 hours. The product continued to crystallize out of solution. The reactor slurry was centrifuged. 55 L of deionized water was charged to the 200-gallon, glass-lined reactor and the centrifuge wet cake was washed. The intermediate was dried under full vacuum (28″ Hg) at about 58° C. for about 19.5 hours. The yield was 82.6 kg 6-chloro-2H-1,3-benzoxazine-2,4(3H)-dione. This intermediate was packaged and stored so that it was not exposed to water.
In the following preparation, absolutely no water can be tolerated in the steps up to the point where distilled water is added. 222 L of dry dimethylacetamide was charged to a dry 200 gallon glass-lined reactor. The reactor agitator was set to 100-125 rpm. Cooling was applied to the condenser and valve reactor overheads were set for distillation. 41.6 kg of dry anhydrous sodium carbonate was charged to the reactor and the reactor charging port was closed. Caution was used due to some off-gassing and a slight exothermic reaction. 77.5 kg of dry 6-chloro-2H-1,3-benzoxazine-2,4(3H)-dione was charged to the reactor. Quickly, 88 kg of dry ethyl-8-bromooctanoate was charged to the reactor. The reaction was evacuated to 22-24 inches of vacuum and the reactor temperature was raised to 65-75° C. The reactor temperature was maintained and the contents were watched for foaming. The reactor mixture was sampled and monitored for conversion by monitoring the disappearance of the bromo ester in the reaction mixture by gas chromatography. The reaction was complete (0.6% bromo ester was found) after about 7 hours. The vacuum was broken and the reactor contents were cooled to 45-50° C. The contents were centrifuged and the filtrate sent into a second 200 gallon glass-lined reactor. 119 L of ethanol (200 proof denatured with 0.5% toluene) was charged to the first 200 gallon reactor, warmed to about 45° C. The filter cake was washed with warm ethanol and the wash was charged to the reaction mixture in the second 200 gallon reactor.
The agitator was started on the second 200 gallon reactor. The reactor contents were cooled to about 29° C. 120 L distilled water was slowly charged to the second reactor, with the water falling directly into the batch. The reactor contents were cooled to about 8° C. The intermediate came out of solution and was held for about 9.5 hours. The resultant slurry was centrifuged. 70 L ethanol was charged to the reactor, cooled to about 8° C., and the centrifuge cake was washed. The wet cake was unloaded into double polyethylene bags placed inside a paper lined drum. The yield was 123.5 kg of ethyl 8-(6-chloro-2H-1,3-benzoxazine-2,4(3H)-dionyl)octanoate.
400 L purified water, USP and 45.4 kg sodium hydroxide pellets were charged to a 200 gallon glass-lined reactor and the agitator was set to 100-125 rpm. 123.5 kg of the ethyl 8-(6-chloro-2H-1,3-benzoxazine-2,4(3H)-dionyl)octanoate wet cake was charged to the reactor. The charging port was closed. Cooling water was applied to the condenser and the valve reactor overheads were set for atmospheric distillation. The reactor contents were heated to about 98° C. and the conversion was monitored by HLPC. Initially (approximately 40 minutes) the reactor refluxed at about 68° C., however, as the ethanol was removed (over about 3 hours) by distillation the reactor temperature rose to about 98° C. The starting material disappeared, as determined by HPLC, at approximately 4 hours. The reactor contents were cooled to about 27° C. 150 L purified water, USP was charged to an adjacent 200 gallon glass-lined reactor and the agitator was set to 100-125 rpm. 104 L concentrated (12M) hydrochloric acid was charged to the reactor and cooled to about 24° C. The saponified reaction mixture was slowly charged (over about 5 hours) to the 200 gallon glass-lined reactor. The material (45 L and 45 L) was split into 2 reactors (200 gallons each) because of carbon dioxide evolution. The product precipitated out of solution. The reaction mixture was adjusted to pH 2.0-4.0 with a 50% sodium hydroxide solution (2 L water, 2 kg sodium hydroxide). The reactor contents were cooled to about 9-15° C. The intermediate crystallized out of solution over approximately 9 hours. The reactor slurry was centrifuged to isolate the intermediate. 50 L purified water, USP was charged to a 200 gallon glass-lined reactor and this rinse was used to wash the centrifuge wet cake. The wet cake was unloaded into double polyethylene bags placed inside a plastic drum. The N-(5-chlorosalicyloyl)-8-aminocaprylic acid was dried under vacuum (27″ Hg) at about 68° C. for about 38 hours. The dry cake was unloaded into double polyethylene bags placed inside a 55-gallon, steel unlined, open-head drums with a desiccant bag placed on top. The dried isolated yield was 81 kg of N-(5-chlorosalicyloyl)-8-aminocaprylic acid.
EXAMPLE 2
Preparation of Disodium N-(5-chlorosalicyloyl)-8-aminocaprylate
A 22 L, Pyrex glass, five-neck, round bottom flask was equipped with an overhead stirrer, thermocouple temperature read out, and heating mantle. The flask was charged with 2602.3 g of N-(5-chlorosalicyloyl)-8-aminocaprylic acid and 4000 mL water. To this stirred slurry was added a solution of 660 g of sodium hydroxide dissolved in 2000 mL water. The mixture was heated to about 55° C. and most of the solids dissolved. The slightly hazy solution was hot filtered through Whatman #1 filter paper to remove the insoluble particulates. The filtrate was transferred to the pot flask of a large laboratory rotary evaporator. The rotary evaporator was operated with a bath temperature of about 60° C. and a pressure of 60 mmHg. Water was removed from the disodium salt solution until a solid mass was obtained in the rotary evaporator pot flask. The vacuum was released and pot flask removed from the rotary evaporator. The solids were scraped from the pot flask into trays. These trays were then placed in a vacuum oven and the solids dried at about 60° C. and full vacuum for about 48 hours. The dried solids were run through a laboratory mill until all the solids passed through a 35 mesh screen. The milled and sieved disodium N-(5-chlorosalicyloyl)-8-aminooctanate was put into trays and placed back into the drying oven. Drying was continued at about 45° C. and full vacuum to obtain 2957.1 g of the desired product as a dry powder.
Titration of the product with hydrochloric acid gave two inflection points consuming approximately 2 molar equivalents of hydrochloric acid. CHN analysis: theoretical (correcting 4.9 wt % water) C, 47.89%, H, 5.37%, N, 3.72%, Na, 12.22%; actual C, 47.69%, H, 5.23%, N, 3.45%, Na, 11.79%.
EXAMPLE 3
Preparation of Monosodium N-(5-chlorosalicyloyl)-8-aminocaprylate
A 22 L, Pyrex glass, five-neck, round bottom flask was equipped with an overhead stirrer, thermocouple temperature read out, and heating mantle. The flask was charged with 2099.7 g of N-(5-chlorosalicyloyl)-8-aminooctanoic acid and 6000 mL water and stirred. To this slurry was added a solution of 265 g of sodium hydroxide dissolved in 2000 mL water. The mixture was heated to about 80° C. causing most of the solids to dissolve. The undissolved material was allowed to settle to the bottom of the flask and the supernate decanted. The resulting mixture was transferred to the pot flask of a large laboratory rotary evaporator. The rotary evaporator was operated with a bath temperature of about 60° C. and a pressure of about 70 mmHg. Water was removed from the disodium salt mixture until a solid mass was obtained in the rotary evaporator pot flask. The vacuum was released and pot flask removed from the rotary evaporator. The solids were scraped from the pot flask into trays. These trays were then placed in a vacuum oven and the solids dried at about 60° C. and full vacuum for about 48 hours. The dried solids were run through a laboratory mill until all the solids passed through a 35 mesh screen. The milled and seived disodium N-(5-chlorosalicyloyl)-8-aminooctanate was put into trays and placed back into the drying oven. Drying was continued at fill vacuum to yield 2161.7 g of the desired product as a dry powder.
Titration of the product with hydrochloric acid gave a single inflection point consuming approximately 1 molar equivalent of hydrochloric acid. CHN analysis: theoretical (correcting 1.14 wt % water) C, 53.05%, H, 5.77%, N, 4.12%, Na, 6.77%; actual C, 52.57%, H, 5.56%, N, 4.06%, Na, 6.50%.
EXAMPLE 4
Disodium and monosodium salts of 5-CNAC were dosed to Rhesus monkeys as follows. Six monkeys in one group were each dosed with one capsule containing the disodium salt, while six monkeys in a second group were each dosed with one capsule containing the monosodium salt. Each capsule was prepared by hand-packing 400 mg 5-CNAC (mono- or di-sodium salt) and 800 μg salmon calcitonin (sCT) into a hard gelatin capsule.
The Rhesus monkeys were fasted overnight prior to dosing and were restrained in chairs, fully conscious, for the duration of the study period. The capsules were administered via a gavage tube followed by 10 ml water.
Blood samples were collected at 15, 30, and 45 minutes and at 1, 1.5, 2, 3, 4, 5, and 6 hours after administration. Plasma concentration sCT was determined by radio-immunoassay. The results from the six monkeys in each dosing group were averaged for each time point and plotted. The maximum mean plasma calcitonin concentration and the area under the curve (AUC) are reported below in Table 1.
TABLE 1
Mean Peak Plasma
Calcitonin
Concentration
(pg/ml ± Standard
Delivery Agent
sCT Dose
Deviation)
Delivery Agent
Dose (mg)
(mg)
(Standard Error)
AUC
Disodium salt
400
800
424 ± 230 (94)
883
of 5-CNAC
Monosodium
400
800
93.2 ± 133 (54)
161
salt of 5-
CNAC
EXAMPLE 5
N-(10-[2-hydroxybenzoyl]amino)decanoic acid was prepared by the procedure described in Example 1 using the appropriate starting materials.
EXAMPLE 6
Preparation of Disodium N-salicyloyl-10-aminodecanoate Ethanol Solvate
A 1 L Pyrex glass, four-neck, round bottom flask was equipped with an overhead stirrer, reflux condenser, thermocouple temperature read out, and heating mantle. The flask was purged with dry nitrogen and the following reaction conducted under an atmosphere of dry nitrogen. The flask was charged with 100 g of N-salicyloyl-10-aminodecanoic acid and 500 mL absolute ethanol. The slurry was heated to about 40° C. with stirring and all of the solids were dissolved. An addition funnel was attached to the reactor and charged with 232.5 g of 11.2 wt % sodium hydroxide dissolved in absolute ethanol. The sodium hydroxide solution was added to the stirred reaction mixture over a fifteen minute period. The reflux condenser was removed from the reactor and replaced with a distillation head and receiver. The reaction mixture was distilled at atmospheric pressure until about 395 g of distillate was collected. The reaction mixture had become a thick slurry during this distillation. The mixture was allowed to cool to room temperature. The thick mixture was transferred to a sintered glass funnel and the solids recovered by vacuum filtration. The ethanol wet cake was placed in a 45° C. vacuum oven and dried to constant weight at full vacuum. The dried material had a weight of about 124.6 g.
Titration of the product with hydrochloric acid gave two inflection points consuming approximately 2 molar equivalents of hydrochloric acid. CHN analysis: theoretical (correcting 0.47 wt % water) C, 57.15%, H, 7.37%, N, 3.51%, Na, 11.51%; actual C, 57.30%, H, 7.32%, N, 3.47%, Na, 11.20%.
EXAMPLE 7
Preparation of Disodium N-(5-chlorosalicyloyl)-8-aminocaprylate Ethanol Solvate
A 12 L, Pyrex glass, four-neck, round bottom flask was equipped with an overhead stirrer, thermocouple temperature read out, reflux condenser, and heating mantle. The flask was purged with dry nitrogen and the following reaction was conducted under an atmosphere of dry nitrogen. The flask was charged with 1000 g of N-(5-chloro-salicyloyl)-8-aminooctanic acid and 3000 mL of absolute ethanol. This slurry was heated to 55° C. with stirring to obtain a slightly hazy solution. The reactor was then charged with 2276 g of 11.2 wt % sodium hydroxide dissolved in absolute ethanol as rapidly as possible. There was a slight exothermic reaction causing the temperature in the reactor to rise to about 64° C. and a precipitate began to form. The reflux condenser was removed and the reactor set for distillation. The reaction mixture was distilled over the next three hours to obtain about 2566 g of distillate. The pot slurry was allowed to cool slowly to room temperature. The product solids in the slurry were recovered by vacuum filtration through a sintered glass funnel to obtain 1390 g of ethanol wet cake. The wet cake was transferred to glass trays and placed in a vacuum oven. The cake was dried to constant weight at about 45° C. and full vacuum. The dry product had a weight of about 1094.7 g.
Titration of the product with hydrochloric acid gave two inflection points consuming approximately 2 molar equivalents of hydrochloric acid. CHN analysis: theoretical (correcting 0 wt % water) C, 50.56%, H, 5.99%, N, 3.47%, Na, 11.39%; actual C, 50.24%, H, 5.74%, N, 3.50% (Na was not measured).
EXAMPLE 8
Preparation of Monosodium N-(10-[2-hydroxybenzoyl]amino)decanoate
A 22 L, Pyrex glass, five-neck, round bottom flask was equipped with an overhead stirrer, thermocouple temperature read out, and heating mantle. The flask was charged with 801.8 g of N-(10-[2-hydroxybenzoyl]amino)decanoic acid and 6000 mL water and stirred. To this slurry was added a solution of 104 g of sodium hydroxide dissolved in 3000 mL water. The mixture was heated to about 63° C. causing most of the solids to dissolve. The resulting slightly hazy mixture was transferred to a pot flask of a large laboratory rotary evaporator. Water was removed from the monosodium salt solution until a solid mass was obtained in the rotary evaporator pot flask. The vacuum was released and pot flask removed from the rotary evaporator. The solids were scraped from the pot flask into trays. These trays were then placed in a vacuum oven and the solids dried at about 80° C. and full vacuum for about 48 hours. The dried solids were identified as the desired monosodium salt. The weight of the dried material was 822.4 g.
Titration of the product with hydrochloric acid gave one inflection point consuming approximately 1 molar equivalents of hydrochloric acid. CHN analysis: theoretical (correcting 0.549 wt % water) C, 61.65%, H, 7.37%, N, 4.23%, Na, 6.94%; actual C, 61.72%, H, 7.38%, N, 3.93%, Na, 6.61%.
EXAMPLE 9
Preparation of Disodium N-salicyloyl-10-aminodecanoate Ethanol Solvate/Heparin Capsules
Disodium N-salicyloyl-10-aminodecanoate (SNAD) ethanol solvate was screen through a 20 mesh sieve. 7.77 g of the screened disodium SNAD ethanol solvate was weighed out and transferred to a mortar. 1.35 g of heparin sodium, USP (182 units/mg), available from Scientific Protein Laboratories, Inc., of Waunakee, Wis., was weighed out and added to the disodium SNAD ethanol solvate in the mortar. The powders were mixed with the aid of a spatula. The mixed powders were transferred to a 1 pint V-blender shell, available from Patterson-Kelley Co. of East Stroudsburg, Pa., and mixed for about 5 minutes.
Size 0 hard gelatin capsules, available from Torpac Inc. of Fairfield, N.J., were each hand filled with about 297-304 mg of the disodium SNAD ethanol solvate/heparin powder. The mean weight of the powder in each capsule was about 300.4 mg and the mean total weight of the capsules (i.e. the weight of the capsule with the powder) was about 387.25 g. Each capsule contained about 259.01 mg disodium SNAD ethanol solvate and about 45.0 mg of heparin.
EXAMPLE 10
Preparation of Monosodium SNAD/Heparin Tablets
Monosodium SNAD/heparin tablets were prepared as follows. SNAD was screened through a 35 mesh sieve. 150.3 g of SNAD, 27.33 g of heparin sodium USP (available from Scientific Protein Laboratories, Inc., of Waunakee, Wis.), 112.43 g of Avicel™ PH 101 (available from FMA Corporation of Newark, Del.), 6.0 g of Ac-Di-Sol™ (available from FMA Corporation), and 2.265 g of talc (Spectrum Chemicals of New Brunswick, N.J.) were weighed out and transferred to a 2 quart V-blender shell, available from Patterson Kelley of East Stroudsburg, Pa., and blended for about 5 minutes. The resulting blend was compressed into slugs using an EK-O tablet press, available from Korsch America Inc, of Sumerset, N.J. The resulting slugs were crushed and sieved through a 20 mesh sieve to produce granules. 3.94 g of talc and 5.25 g of Ac-Di-Sol were added to the granules and transferred to a 2 quart V-blender shell and mixed for about 5 minutes. 2.72 g of magnesium stearate were added to the granules in the V-blender and mixed for an additional 3 minutes. The resulting formulation was made into tablets using an EK-O tablet press. The mean tablet weight was 320.83 mg.
EXAMPLE 11
4 cynomolgus macaque monkeys (2 male, 2 female) weighing about 3.0 kg each were dosed with two of the capsules as prepared in Example 9 above. The dose for each monkey was about 150 mg/kg of the disodium SNAD ethanol solvate and about 30 mg/kg of heparin.
The dosing protocol for administering the capsules to each animal was as follows. The animal was deprived food overnight prior to dosing (and 2 hours post dosing). Water was available throughout the dosing period and 400 ml juice was made available to the animal overnight prior to dosing and throughout the dosing period. The animal was restrained in a sling restraint. A capsule was placed into a “pill gun”, which is a plastic tool with a cocked plunger and split rubber tip to accommodate a capsule. The pill gun was inserted into the esophagus of the animal. The plunger of the pill gun was pressed to push the capsule out of the rubber tip into the esophagus. The pill gun was then retracted. The animal's mouth was held closed and approximately 5 ml reverse osmosis water was administered into the mouth from the side to induce a swallowing reflex. The throat of the animal was rubbed further to induce the swallowing reflex.
Blood samples (approximately 1.3 ml) were collected from an appropriate vein (femoral, brachial or saphenous) before dosing and 10, 20, 30, 40 and 50 minutes and 1, 1.5, 2, 3, 4 and 6 hours after dosing. Blood samples were collected into a tube with about 0.13 ml of about 0.106 M citrate solution. Blood was added to fill the tube to the 1.3 ml line. The tube was then placed on wet ice pending centrifugation. Blood samples were centrifuged and refrigerated (2-8° C.) for about 15 minutes at 2440 rcf (approximately 3680 rpm). The resultant plasma was divided into 2 aliquots, stored on dry ice or frozen (at approximately −70° C.) until assayed.
Assaying
Plasma heparin concentrations were determined using the anti-Factor Xa assay CHROMOSTRATE™ heparin anti-X a assay, available from Organon Teknika Corporation of Durham, N.C. Results from the animals were averaged for each time point. The maximum averaged value, which was reached at about 1 hour after administration, was 1.54±0.17 IU/mL.
COMPARATIVE EXAMPLE 11A
The procedure in Example 11 was repeated with tablets of the monosodium salt of SNAD as prepared in Example 10 instead of the capsules of the ethanol solvate of the disodium salt of SNAD. Two tablets were dosed to each of approximately 4.0 kg monkeys. The dosage was approximately 150 mg/kg SNAD (free acid equivalent) and 30 mg/kg heparin. The maximum average plasma heparin concentration was reached at 2 hours after administration and was 0.23±0.19 IU/mL.
EXAMPLE 12
Preparation of Mono-Sodium N-(8-[2-hydroxybenzoyl]amino)caprylate (SNAC) Salt
The free acid of SNAC (i.e. N-(8-[2-hydroxybenzoyl]amino)caprylic acid) was prepared by the method of Example 1 using the appropriate starting materials.
Into a clean 300 gallon reactor was charged 321 L of ethanol, which was denatured with 0.5% toluene. While stirring, 109 kg (dry) of the free acid of SNAC was added. The reactor was heated to 28° C. and maintained at a temperature above 25° C. A solution of 34 L purified water, USP and 15.78 kg sodium hydroxide was prepared, cooled to 24° C., and added to the stirring reactor over 15 minutes, keeping the reaction temperature at 25-35° C. The mixture was stirred for an additional 15 minutes.
Into an adjacent reactor was charged 321 L of ethanol, which was denatured with 0.5% toluene. The reactor was heated to 28° C. using a circulator. The solution from the first reactor was added to the second reactor over 30 minutes, keeping the temperature above 25° C. The contents were stirred and 418 L of heptane was added. The reaction mixture was cooled to 10° C., centrifuged and then washed with 60 L of heptane. The product was collected and dried in a Stokes oven at 82° C. under 26″ Hg vacuum for about 65 hours (over a weekend). 107.5 kg monosodium SNAC (i.e. the monosodium salt of N-(8-[2-hydroxybenzoyl]amino)caprylic acid) was recovered.
EXAMPLE 13
Preparation of SNAC Di-sodium Salt
Free acid of SNAC (i.e. N-(8-[2-hydroxybenzoyl]amino)caprylic acid) was prepared as follows. The monosodium SNAC prepared in Example 12 was acidified with 1 equivalent of concentrated hydrochloric acid in water and stirred. The solution was then vacuum filtered and vacuum dried to yield the free acid.
100 g of the free acid of SNAC was weighed into a 2 liter 4-neck round bottomed flask and 500 ml anhydrous ethanol was added. The temperature was set to about 40° C. to allow the solids to go into solution. 255.7 g of 11.2% (w/w) sodium hydroxide solution in ethanol was added by addition funnel over 15 minutes as the temperature was raised to about 82° C. 383.1 g ethanol was distilled off at a head temperature of about 76-79° C over about 1.5 hours. The reaction mixture was allowed to cool to room temperature over nitrogen, held for about 2 hours, and vacuum filtered through a coarse funnel to recover the solids. The filter cake was washed with the filtrate, transferred to an evaporating dish, and pulled under full vacuum at room temperature overnight in a dessicator. 90.5 g (68%) ethanol solvate di-sodium salt of SNAC as a pink solid was recovered. Melting point >200° C. (limit of instrument used). HPLC trace showed 100 area %. NMR showed desired product. CHN for C 17 H 25 NO 5 Na 2 .0.1265H 2 O) calculated: C, 54.94; H, 6.85; N, 3.77, Na, 12.37; found: C, 55.04, H, 6.56, N, 3.89, Na, 12.34.
The di-sodium salt, monohydrate of SNAC was made by drying the ethanol solvate made above at 80° C. full vacuum for 22.75 hours and cooling at room temperature open to air to form the monhydrate. The structure of the hydrate was verified by elemental analysis: calculated for C 15 H 19 NO 4 Na 2 .0.127H 2 O: C, 53.01; H, 6.18; N, 4.12; Na, 13.53; found: C, 53.01; H, 6.10; N, 3.88; Na, 13.08; and by 1 HNMR (300 MHz, DMSO-d 6 ): d 12.35 (1H, s), 7.55 (1H, dd), 6.8 (1H, dt), 6.25 (1H, dd), 6.00 (1H, dt), 3.2 (2H, q), 1.9 (2H, t), 1.45 (4H, bq), 1.25 (6H, bm). Melting point >250° C. (limit of instrument used).
EXAMPLE 14
Preparation of SNAD Mono-sodium Salt
The free acid of SNAD may be prepared by the method described in Example 1 using the appropriate starting materials.
206 L ethanol denatured with 0.5% toluene and 33.87 kg SNAD were charged to a reactor, stirred for 1 hour, and sent through a filter press. 1.7 kg Celite (diatomateous earth), which is available from Celite Corporation of Lompoc, Calif., was added to the reactor. The contents of the reactor were sent through a filter press and the solution was retained in a separate vessel. The reactor was rinsed with 5 gallons of deionized water. The solution was reintroduced to the reactor with a sodium hydroxide (NaOH) solution made from 4.5 kg NaOH in 12 L deionized water. The reactor contents were stirred for 30 minutes and 30 gallons of solvent were removed by vacuum stripping at elevated temperature. The reactor contents were cooled to 60° C. and then poured into two 100 gallon tanks containing 65 gallons heptane each, with rapid stirring. Stirring was continued for 2 hours. The solution was centrifuged, washed with 15 gallons heptane, spun dry, dried in an oven at 45° C. under 26″ Hg for 24 hours, and then sent through a Fitzmill grinder (available from the Fitzpatrick Company of Elmhurst, Ill.). 32 kg of the monosodium salt form of SNAD was recovered as a light tan powder (melting point 190-192° C., 99.3% pure by HPLC, molecular weight: 329.37). Titration revealed about 96% mono-sodium and about 4% di-sodium salt form of SNAD.
EXAMPLE 15
Preparation of SNAD Di-sodium Salt
The free acid of SNAD (N-(10-[2-hydroxybenzoyl]amino)decanoic acid) was prepared by the method described in Example 1 using the appropriate starting materials.
100 g of the free acid of SNAD was weighed into a 1 liter 4-neck round bottomed flask. 500 ml anhydrous ethanol was charged to the flask. The temperature was set to about 40° C. to allow the solids to go into solution. A light orange solution was obtained. 232.5 g of 11.2 (w/w) sodium hydroxide solution in ethanol was added by addition funnel over 15 minutes as the temperature was raised to about 82° C. 397.8 g ethanol was distilled off at a head temperature of about 75-79° C. over about 3 hours. The reaction mixture was allowed to cool to room temperature overnight under nitrogen. The resulting slurry was vacuum filtered through a coarse funnel to recover the solids and the filter cake was washed with the filtrate. The wet filter cake was transferred to an evaporating dish and placed into a 50° C. oven under full vacuum overnight. 124.55 g (96%) SNAD di-sodium salt, ethanol solvate as a pale pink solid was recovered. Melting point>200° C. (limit of instrument used). HPLC trace showed 100 area %. NMR showed desired product. CHN for C 19 H 29 NO 5 Na 2 ) calculated: C, 57.42; H, 7.35; N, 3.52, Na, 11.57; found: C, 57.37; H, 7.35; N, 3.41, Na, 11.63.
The di-sodium salt, monohydrate of SNAD was made by drying the ethanol solvate made above at about 80° C. full vacuum for about 19 hours and cooling the solution at room temperature open to air to form the monhydrate. The structure of the hydrate was verified by elemental analysis: calculated for C 17 H 23 NO 4 Na 2 .H 2 O: C, 55.28; H, 6.82; N, 3.79; Na, 12.45; found: C, 56.03; H, 6.67; N, 3.67; Na, 12.20; and 1 HNMR (300 MHz, DMSO-d 6 ): d 12.35 (1H, s), 7.6 (1H, dd), 6.8 (1H, dt), 6.25 (1H, dd), 6.00 (1H, dt), 3.2 (2H, q), 2.0 (2H, t), 1.9 (2H, t), 1.45 (4H, bt), 1.25 (10H, bm). Melting point>250° C. (limit of instrument used).
EXAMPLE 16
Oral Delivery of Heparin
Oral gavage (PO) dosing solutions containing heparin sodium USP and either the mono-sodium or di-sodium salt form of the delivery agent compound SNAC were prepared in water. The delivery agent compound and heparin (166.9 IU/mg) were mixed by vortex as dry powders. This dry mixture was dissolved in water, vortexed and sonicated at about 37° C. to produce a clear solution. The pH was not adjusted. The final volume was adjusted to about 10.0 ml. The final delivery agent compound dose, heparin dose and dose volume amounts are listed below in Table 2 below.
The typical dosing and sampling protocols were as follows. Male Sprague-Dawley rats weighing between 275-350 g were fasted for 24 hours and were anesthetized with ketamine hydrochloride (about 88 mg/kg) intramuscularly immediately prior to dosing and again as needed to maintain anesthesia. A dosing group of ten rats was administered one of the dosing solutions. An 11 cm Rusch 8 French catheter was adapted to a 1 ml syringe with a pipette tip. The syringe was filled with dosing solution by drawing the solution through the catheter, which was then wiped dry. The catheter was placed down the esophagus leaving 1 cm of tubing past the incisors. Solution was administered by pressing the syringe plunger.
Citrated blood samples were collected by cardiac puncture 0.25, 0.5, 1.0 and 1.5 hours after administration. Heparin absorption was verified by an increase in clotting time as measured by the activated partial thromboplastin time (APTT) according to the method of Henry, J. B., Clinical Diagnosis and Management by Laboratory Methods, Philadelphia, Pa., W. B. Saunders (1979). Previous studies indicated baseline values of about 20 seconds. Results from the animals in each group were averaged for each time point and the maximum APTT value (in seconds) is reported below in Table 2. Heparin absorption was also verified by an increase in plasma heparin measured by the anti-Factor Xa assay CHROMOSTRATE® Heparin anti-X a assay, available from Organon Teknika Corporation of Durham, N.C. Baseline values are about zero IU/ml. Plasma heparin concentrations from the animals in each group were averaged for each time point and plotted. The peak of these mean plasma heparin concentrations is reported below in Table 2.
TABLE 2
Mean Peak
Volume
Compound
Heparin
Mean Peak
Factor Xa
Com-
Dose
Dose
Dose
APTT (sec) ±
(IU.ml) ±
pound
(ml/kg)
(mg/kg)
(mg/kg)
SE
SE
SNAC-
3
300
100
247 ± 28.5
2.597 ± 0.13
mono
SNAC-
3
300
100
300 ± 0
2.81 ± 0.17
di
EXAMPLE 17
Oral Delivery of Low Molecular Weight Heparin (LMWH)
Oral dosing (PO) compositions containing low molecular weight heparin (LMWH) and either the mono-sodium or di-sodium salt form of the delivery agent compound SNAD were prepared in water. The delivery agent compound and LMWU (Parnaparin, 91 IU/mg, average molecular weight about 5,000), available from Opocrin of Modena, Italy, were mixed by vortex as dry powders. The dry mixture was dissolved in water, vortexed, and sonicated at about 37° C. to produce a clear solution. The pH was not adjusted. The final volume was adjusted to about 10.0 ml. The final delivery agent compound dose, LMWH dose, and dose volume amounts are listed below in Table 3 below.
The dosing was performed as described in Example 16 above.
Citrated blood samples were collected by cardiac puncture 0.5, 1.0, 2.0, 3.0 and 4.0 hours after administration. Heparin absorption was verified by an increase in plasma heparin measured by the anti-Factor Xa assay CHROMOSTRATE® Heparin anti-X a assay, available from Organon Teknika Corporation of Durham, N.C. Baseline values were determined earlier and found to be about zero IU/ml. Plasma heparin concentrations from the animals in each group were averaged for each time point and plotted. The peak of these mean plasma heparin concentrations is reported below in Table 3.
TABLE 3
Mean
Peak Plasma
Volume
Compound
Heparin
Dose
Dose
LMWH
Concentration
Compound
(ml/kg)
(mg/kg)
Dose (mg/kg)
(IU/ml) ± SE
SNAD-mono
3
300
3000
0.88 ± 0.17
SNAD-di
3
300
3000
1.21 ± 0.15
EXAMPLE 18
Preparation of N-(5-chlorosalicylovl)-8-aminocaprylic Acid (5-CNAC)
5-chlorosalicylamide (280 g, 1.6 mol) and acetonitrile (670 ml) were placed in a 5 liter, 4-neck, round bottomed, flask under a nitrogen atmosphere and stirred. Pyridine (161.3 g, 2.0 mol) was added over a period of 25 minutes to the mixture. The reaction vessel was placed in an ice/water bath and portionwise addition of ethyl chloroformate was started. This addition continued over a period of one hour. When the addition was completed the ice/water bath was removed and the reaction mixture was allowed to come to room temperature. The reaction mixture was allowed to stir for an additional one hour at room temperature before the reaction vessel was reconfigured for distillation at atmospheric pressure. The distillation that followed yielded 257.2 g of distillate at a head temperature of 78° C. 500 ml of deionized water was added to the reaction mixture that remained in the flask and the resulting slurry was vacuum filtered. The filter cake was washed with 200 ml deionized water and was allowed to dry overnight in vacuo at room temperature. 313.6 g (97.3%) of 6-chloro carsalam was isolated after drying. An additional batch was made using this same method, yielding 44.5 g 6-chloro-2H-1,3-benzoxazine-2,4(3H)-dione.
Sodium carbonate (194.0 g, 1.8 mol) was added to a 5 liter, 4-neck, round bottomed, flask containing 6-chloro-2H-1,3-benzoxazine-2,4(3H)-dione (323.1 g, 1.6 mol) and dimethylacetamide (970 ml). Ethyl-8-bromooctanoate (459.0 g, 1.8 mol) was added in one portion to the stirring reaction mixture. The atmospheric pressure in the reaction vessel was reduced to 550 mm Hg and heating of the reaction mixture was started. The reaction temperature was maintained at 70° C. for approximately 5 hours before heating and vacuum were discontinued. The reaction mixture was allowed to cool to room temperature overnight. The reaction mixture was vacuum filtered and the filter cake was washed with ethyl alcohol (525 ml). Deionized water (525 ml) was slowly added to the stirred filtrate and a white solid precipitated. An ice/water bath was placed around the reaction vessel and the slurry was cooled to 50° C. After stirring at this temperature for approximately 15 minutes the solids were recovered by vacuum filtration and the filter cake was washed first with ethanol (300 ml) and then with heptane (400 ml). After drying overnight at room temperature in vacuo, 598.4 g (99.5%) of ethyl 8-(6-chloro-2H-1,3-benzoxazine-2,4(314)-dionyl)octanoate was obtained. An additional 66.6 g of ethyl 8-(6-chloro-2H-1,3-benzoxazine-2,4(3H)-dionyl)octanoate was made by this same method.
Ethyl 8-(6-chloro-2H-1,3-benzoxazine-2,4(3H)-dionyl)octanoate (641 g, 1.7 mol) and ethyl alcohol (3200 ml) were added to a 22 liter, five neck flask. In a separate 5 liter flask, sodium hydroxide (NaOH) (288.5 g, 7.2 mol) was dissolved in deionized water (3850 ml). This mixture was added to the reaction mixture contained in the 22 liter flask. A temperature increase to 40° C. was noted. Heating of the reaction mixture was started and when the reaction temperature had increased to 50° C. it was noted that all of the solids in the reaction mixture had dissolved. A temperature of 50° C. was maintained in the reaction mixture for a period of 1.5 hours. The reaction flask was then set up for vacuum distillation. 2200 ml of distillate were collected at a vapor temperature of 55° C. (10 mm Hg) before the distillation was discontinued. The reaction flask was then placed in an ice/water bath and concentrated hydrochloric acid (HCl) (752 ml) was added over a period of 45 minutes. During this addition the reaction mixture was noted to have thickened somewhat and an additional 4 liters of deionized water was added to aid the stirring of the reaction mixture. The reaction mixture was then vacuum filtered and the filter cake was washed with 3 liters of deionized water. After drying in vacuo at room temperature 456.7 g (83.5%) of N-(5-chlorosalicyloyl)-8-aminocaprylic acid was isolated.
EXAMPLE 19
Lyophilization of Salmon Calcitonin (sCT) and the Sodium Salt of 5-CNAC
Preparation of the Sodium Salt of 5-CNAC
The percent purity of 5-CNAC was determined as follows. 0.9964 g of the free acid of 5-CNAC was quantitatively dissolved in 40 ml of methanol. 2 ml of distilled water was added to this solution after the solids were dissolved. The solution was titrated in methanol with 0.33 N sodium hydroxide using a computer controlled burette (Hamilton automatic burette available from Hamilton of Reno, Nev.). A glass electrode (computer controlled Orion model 525A pH meter available from VWR Scientific of South Plainfield, N.J.) was used to monitor the pH of the solution. The solution was stirred with a magnetic stirrer.
The volume of titrant to reach the second pH inflection point was 18.80 ml. The inflection point, determined by interpolation between the two data points where the second derivative of the pH plot changed from positive to negative, occurred at pH, 11.3. The purity of the free acid was determined using the following equation:
% purity = 100 × ( Volume of Titrant in ml ) × Normality × Molecular Weight 1000 × Equivalents × Sample Weight
where Normality is the normality of sodium hydroxide, Molecular Weight is the molecular weight of 5-CNAC free acid (313.78), Equivalents is the equivalence of free acid (2 in this case, since it is dibasic), and Sample Weight is the weight of the free acid sample being titrated.
The purity was found to be 97.0%.
9.3458 g 5-CNAC powder was weighed out. The amount of 0.33 N sodium hydroxide needed to have a sodium hydroxide to free acid molar ratio of 1.6 was calculated using the following equation:
Volume of NaOH ( in ml ) = Free Acid Weight × ( % purity ) × 1000 × 1.6 313.78 × 100 × Normality
where the Free Acid Weight is the weight of free acid in formulated sample, the % purity is the percentage purity of 5-CNAC, Normality is the normality of sodium hydroxide, and the Volume of NaoH is the amount of sodium hydroxide needed.
5-CNAC and 153.3 ml of 0.33 N sodium hydroxide (NaOH) was mixed in a Pyrex bottle. The resulting slurry was warmed in a steam bath to 60-80° C. The warm slurry became a clear solution in about 15 minutes with occasional stirring. The solution was cooled to room temperature. The pH of this solution was 8.1.
Preparation of sCT/Sodium Salt of 5-CNAC Solution
The aqueous solution of 5-CNAC sodium salt was filtered through a sterile, 0.45 micron cellulose acetate, low protein binding membrane on a 150 ml Corning filter (available from VWR Scientific Product, S. Plainfield, N.J.). The pH of the solution was about 8.3.
Dry salmon calcitonin (sCT), stored at −70° C., was brought to room temperature. Next, 18.692 mg of sCT was weighed out and dissolved in 10 ml of 0.1 M mono sodium phosphate buffer solution at a pH of about 5, with gentle mixing.
The sCT solution was added to the 5-CNAC sodium salt solution with gentle mixing, taking precaution to avoid foaming or vortexing.
Lyophilization of sCT/Sodium Salt of 5-CNAC Solution
Shelves of the lyophilizer (Genesis 25 LL-800 from The Virtis Company of Gardiner, N.Y.) were prefrozen to about −45° C.
Approximately 260 ml of sCT/sodium salt of 5-CNAC solution was added to a 30 cm×18 cm stainless steel tray to give a cake thickness of about 0.48 cm. Four clean, dry thermocouple probe tips were inserted into the solution such that the probe tip touched the solution level in the center. The probes were secured with clips to the side of the tray and the trays were loaded on to the precooled shelves.
The gel permation chromatograph (GPC2) was programmed for the cycle shown in Table 4.
TABLE 4
Lyophilization Process Cycle
Step
Temperature
Pressure set point (m torr)
Time (minute)
1
−45° C.
none (Prefreeze)
120
2
−30° C.
300
180
3
−20° C.
200
200
4
−10° C.
200
360
5
−0° C.
200
720
6
10° C.
100
540
7
20° C.
100
360
8
25° C.
100
180
During lyophilization the pressure varied from 350 to 45 mtorr. When the lyophilization cycle was completed, the system cycle was terminated and the system vacuum was released. The trays were carefully removed from the shelves and the lyophilized powder was transferred into amber HDPE NALGENE® bottles, available from VWR Scientific.
Using the above cycle for lyophilization, a powder with about 3% moisture content was obtained. The powder was hand packed into hard gelatin capsules (size 0EL/CS), which are available from Capsugel, a division of Warner Lamber Co., of Greenwood, S.C., as needed. The filled capsules and the lyophilized powder were stored in a closed container with dessicant.
EXAMPLE 20
Preparation of Unlyophilized sCT/Sodium Salt of 5-CNAC
Acetic anhydride (56.81 ml, 61.47 g, 0.6026 mol), 5-chlorosalicylic acid (100.00 g, 0.5794 mol), and xylenes (200 ml) were added to a 500 ml, three-neck flask fitted with a magnetic stir bar, a thermometer, and a Dean-Stark trap with condenser. The flask was heated to reflux, the reaction mixture clearing to a yellow solution around 100° C. Most of the volatile organics (xylenes and acetic acid) were distilled into the Dean-Stark trap (135-146° C.). Distillation was continued for another hour, during which the pot temperature slowly rose to 190° C. and the distillate slowed to a trickle to drive over any more solvent. Approximately 250 ml of solvent was collected. The residue was cooled below 100° C. and dioxane was added.
A 2N sodium hydroxide (222.85 ml, 0.4457 mol) and 8-aminocaprylic acid (70.96 g, 0.4457 mol) solution was added to the solution of oligo(5-chloroasalicylic acid) (0.5794 mol) in dioxane. The reaction mixture was heated to 90° C. for 5.5 hours, then shut off overnight and restarted in the morning to heat to reflux (after restarting the heating the reaction was monitored at which time the reaction was determined to have finished, by HPLC). The reaction mixture was cooled to 40° C. The dioxane was stripped off in vacuo. The residue was taken up in 2N sodium hydroxide and acidified. The material did not solidify. The material was then taken up in ethyl acetate and extracted (2×100 ml) to remove excess dioxane. The ethyl acetate layer was dried over sodium sulfate and concentrated in vacuo. The easily filtered solids were collected by filtration. The remaining material was taken up in 2N NaOH. The pH was adjusted to 4.3 to selectively isolate product from starting material. Once at pH, 4.3, the solids were filtered off and recrystallized in a 1:1 mixture of ethanol and water. Any insoluble material was hot filtered out first. All the solids which were collected were combined and recrystallized from the mixture of ethanol and water to give 52.06 g of the free acid product as a white solid.
The sodium salt solution was prepared according to the method described in Example 19 using 0.2 N NaOH solution. Percent purity was calculated to be 100% using 0.5038 g of 5-CNAC and 16.06 ml of 0.2 N NaOH. The sodium salt solution was prepared using 250 ml of 0.2 N NaOH and 9.4585 g of 5-CNAC prepared as described above. The solution was filtered through a 0.45 micron filter.
EXAMPLE 21
Oral Delivery of sCT/Sodium Salt of 5-CNAC in Rats
Male Sprague-Dawley rats weighing between 200-250 g were fasted for 24 hours and were administered ketamine (44 mg/kg) and chlorpromazine (1.5 mg/kg) 15 minutes prior to dosing. The rats were administered one of the following:
(4a) orally, one capsule of 13 mg lyophilized powder as prepared as in Example 19 with 0.5 ml of water to flush the capsule down; (4b) orally, 1.0 ml/kg of a reconstituted aqueous solution of the lyophilized powder prepared in Example 19; (4c) orally, 1.0 ml/kg of “fresh”, unlyophilized aqueous solution of 5-CNAC sodium salt as prepared in Example 20 with sCT; or (4d) subcutaneously, 5 mg/kg of sCT.
Doses (4a), (4b) and (4c) contained 50 mg/kg of the sodium salt of 5-CNAC and 100 mg/kg of sCT. Doses for (4a) are approximate because the animals were given one capsule filled with the stated amount of powder based on an average animal weight of 250 g, whereas actual animal weight varied. This is also the case in all later examples where a capsule is dosed.
The reconstituted solution for (4b) was prepared by mixing 150 mg of the lyophilized powder prepared as in Example 19 in 3 ml of water. The reconstituted solution was dosed at 1.0 ml/mg.
The “fresh” solution for (4c) was prepared from unlyophilized material using 150 mg 5-CNAC sodium salt prepared in Example 20 in 3 ml water plus 150 ml of sCT stock solution (2000 ml/ml prepared in 0.1M phospate buffer, pH adjusted to 4 with HCl and NaOH. The “fresh” solution had a final concentration of 50 mg/ml 5-CNAC sodium salt and of 100 mg/ml sCT, and 1.0 ml/kg was dosed.
The subcutaneous doses were prepared by dissolving 2 mg of sCT in 1 ml water. 5 mL of this solution was added to 995 mL of water. This solution was dosed at 0.5 ml/kg.
Blood samples were collected serially from the tail artery. Serum sCT was determined by testing with an EIA kit (Kit # EIAS-6003 from Peninsula Laboratories, Inc., San Carlos, Calif.), modifying the standard protocol from the kit as follows: incubated with 50 ml peptide antibody for 2 hours with shaking in the dark, washed the plate, added serum and biotinylated peptide and diluted with 4 ml buffer, and shook overnight in the dark. Results are illustrated in Table 5, below.
TABLE 5
Oral Delivery of sCT/Sodium Salt of 5-CNAC in Rats
Mean Peak
Dose of Sodium
sCT
Serum
Salt of 5-CNAC
Dose
sCT ± SD
Dosage form
(mg/kg)
(mg/kg)
(pg/ml)
(4a) capsule
50*
100*
1449 ± 2307
(4b) reconstituted solution
50
100
257 ± 326
(4c) unlyophilized solution
50
100
134 ± 169
(4d) subcutaneous
—
5
965 ± 848
*approximate dose due to variations in animal weight
EXAMPLE 22
Oral Delivery of sCT/Sodium Salt of 5-CNAC in Rats
According to the method described in Example 21, rats were administered one of the following:
(5a) orally, one capsule of 13 mg lyophilized powder with 1 ml water to flush the capsule down; (5b) orally, one capsule of 6.5 mg lyophilized powder with 1 ml water to flush the capsule down; (5c) orally, one capsule of 3.25 mg lyophilized powder with 1 ml water to flush the capsule down; (5d) subcutaneously 5 mg/kg of sCT.
Approximate amounts of delivery agent and sCT, as well as the results, are shown in Table 6 below.
TABLE 6
Oral Delivery of sCT/Sodium Salt of 5-CNAC in Rats
Dose of Sodium
sCT
Salt of 5-CNAC
Dose
Mean Peak
Dosage form
(mg/kg)
(mg/kg)
Serum sCT ± SD (pg/ml)
(5a) capsule
50*
100*
379 ± 456
(5b) capsule
25*
50*
168 ± 241
(5c) capsule
12.5*
25*
0
(5d) subcutaneous
—
5
273 ± 320
*approximate dose due to variations in animal weight
EXAMPLE 23
Preparation of N-(5-chlorosalicyloyl)-4 Aminobutyric Acid
Sodium carbonate (30 g, 0.2835 mol) was added to a 500 ml 3-neck, round-bottomed flask containing 6-chloro-2H-1,3-benzoxazine-2,4(3H)-dione (prepared as in Example 18) (50 g, 0.2532 mol) and dimethylacetamide (75 ml) and stirred. Methyl-4-bromobutyrate (45.83 g, 0.2532 mol) was added in one portion to the stirring reaction mixture, and heating of the reaction mixture was started. The reaction temperature was maintained at 70° C. and allowed to heat overnight. Heating was discontinued, and the reaction mixture was allowed to cool to room temperature.
The reaction mixture was vacuum filtered and the filter cake was washed with ethyl alcohol. The filter cake and filtrate were monitored by HPLC to determine where the product was. Most of the product was washed into the filtrate, although some product was still present in the filter cake. The filter cake was worked up to recover product to increase the final yield. The filter cake was washed first with copious amounts of water, then with ethyl acetate. The washes from the filter cake were separated and the ethyl acetate layer was next washed twice with water, once with brine, then dried over sodium sulfate, isolated and concentrated in vacuo to recover more solids (solids B). Water was added to the filtrate that had been isolated earlier and solids precipitated out. Those solids were isolated (solids A). Solids A and B were combined and transferred to a round bottom flask and 2N NaOH was added to the filtrate and heating was begun with stirring. The reaction was monitored by HPLC to determine when the reaction was done. The reaction was cooled to 25° C., stirred overnight, and concentrated in vacuo to remove excess ethanol. An ice/water bath was placed around the reaction vessel and the slurry was acidified. The solids were recovered by vacuum filtration and the filter cake was washed with water, dried and sent for NMR analysis.
The solids were isolated and transferred to an Erlenmeyer flask to be recrystallized. The solids were recrystallized with methanol/water. Solids formed and were washed into a Buchner funnel. More solids precipitated out in the filtrate and were recovered. The first solids recovered after recrystalization had formed a methyl ester. All the solids were combined, 2N NaOH was added and heated again to reflux to regain the free acid. Once the ester had disappeared, as determined by HPLC, acidification of the mixture to a pH of about 4.7 caused solids to develop.
The solids were isolated by filtration and combined with all the solids and recrystallized using a 1.5:1.0 ratio of methanol to water. White solids precipitated out overnight and were isolated and dried to give 23.48 g of N-(5-chlorosalicyloyl)-4 aminobutyric acid at a 36% yield.
It was later determined that the filter cake should have first been washed with excess ethyl alcohol to avoid having the product remain in the filter cake. From that point, the filtrate and 2N NaOH could be heated with stirring, cooled to 25° C. and concentrated in vacuo to remove excess ethanol. In an ice/water bath, the slurry acidified to a pH of 4.7. The solids recovered by vacuum filtration and the filter cake were washed with water. The solids were then isolated and recrystallized.
Example 24
Lyophilization of sCT/Sodium Salt of N-(5-chlorosalicyloyl)-4 Aminobutyric Acid
Following the procedure in Example 19, a lyophilized powder of sCT/sodium salt of N-(5-chlorosalicyloyl)-4 aminobutyric acid was prepared and packed into capsules. 10.528 g of N-(5-chlorosalicyloyl)-4 aminobutyric acid as prepared in Example 23 was dissolved in 150 ml water. 4.72 ml 10N NaOH was added. 21.0566 mg of sCT was dissolved in 10 ml phosphate buffer and the sCT/phosphate buffer mixture was added to the delivery agent solution. Water was added to make the volume 250 ml.
EXAMPLE 25
Oral Delivery of sCT/Sodium Salt of N-(5-chlorosalicyloyl)-4 Aminobutyric Acid in Rats
According to the method of Example 21, with the exception that the standard protocol for the EIA kit was followed, rats were administered orally one capsule of 13 mg lyophilized powder with 0.5 ml water to flush the capsule down with the approximate amounts of the sodium salt of N-(5-chlorosalicyloyl)-4 aminobutyric acid and sCT as set forth in Table 7 below. The results are also shown in Table 7.
TABLE 7
Oral Delivery of sCT/Sodium Salt of N-(5-chlorosalicyloyl)-
4 aminobutyric acid in Rats
Dose of Sodium
Salt of N-(5-
chlorosalicyloyl)-4
Mean Peak
aminobutyric acid
sCT
Serum sCT ± SD
Dosage form
(mg/kg)
Dose (mg/kg)
(pg/ml)
(8a) capsule
50*
400*
1112 ± 1398
(8b) capsule
50*
800*
2199 ± 4616
*approximate dose due to variations in animal weight
EXAMPLE 26
Preparation of 5-CNAC for Tableting
To a clean, dry, 200 gallon glass-lined reactor, 178 L of dry acetonitrile was added. The agitator was set to 100-125 RPM and the reactor contents were cooled to 9° C. 74 kg of 5-chloro salicylamide, available from Polycarbon Industries of Leominster, Mass., was charged to the reactor and the charging port was closed. 47 L of dry pyridine was charged to the reactor. The slurry was cooled to 9° C. prior to proceeding. Cooling was applied to the reactor condenser and valve overheads were set for total reflux. Over 2 hours, 49.7 kg of ethylchloroformate was charged to the 200 gallon reactor while maintaining the batch temperature at 14° C. Note that ethylchloroformate can contain 0.1% phosgene and is extremely reactive with water. The reacton is highly exothermic and requires the use of a process chiller to moderate reaction temperature. The reactor contents were agitated for 30 minutes at 10-14° C. once the ethylchloroformate addition was complete. The reactor contents were heated to 85° C. over 25 minutes, collecting all distillate into a receiver. The reactor contents were held at 85-94° C. for approximately 6 hours, collecting all distilled material into a receiver. The reaction mixture was sampled and the conversion (>90%) monitored by HPLC. The conversion was found to be 99.9% after 6 hours. The reactor contents were cooled to 19° C. over a one-hour period. 134 L of deionized water was charged to the reactor. A precipitate formed immediately. The reactor contents were cooled to 5° C. and agitated for 10.5 hours. The product continued to crystallize out of solution. The reactor slurry was centrifuged. 55 L of deionized water was charged to the 200-gallon, glass-lined reactor and the centrifuge wet cake was washed. The intermediate was dried under full vacuum (28″ Hg) and 58° C. for 19.5 hours. The yield was 82.6 kg 6-chloro-2H-1,3-benzoxazine-2,4(3H)-dione. This intermediate was packaged and stored so that it was not exposed to water.
In the next preparation, absolutely no water can be tolerated in the steps up to the point where distilled water is added.
222 L of dry dimethylacetamide was charged to a dry 200 gallon glass-lined reactor. The reactor agitator was set to 100-125 RPM. Cooling was applied to the condenser and valve reactor overheads were set for distillation. 41.6 kg of dry anhydrous sodium carbonate was charged to the reactor and the reactor charging port was closed. Caution was used due to some off-gassing and a slight exotherm. 77.5 kg of dry 6-chloro-2H-1,3-benzoxazine-2,4(3H)-dione was charged to the reactor. Quickly, 88 kg of dry ethyl-8-bromooctanoate was charged to the reactor. 22-24 inches of vacuum was applied and the reactor temperature was raised to 65-75° C. The reactor temperature was maintained and the contents were watched for foaming. The reactor mixture was sampled and monitored for conversion by monitoring for the disappearance of the bromo ester in the reaction mixture by gas chromatography (GC). The reaction was complete (0.6% bromo ester was found) after 7 hours. The vacuum was broken and the reactor contents cooled to 45-50° C. The contents were centrifuged and the filtrate sent into a second 200-gallon glass-lined reactor. 119 L of ethanol (200 proof denatured with 0.5% toluene) was charged to the first 200-gallon reactor, warmed to 45° C. and the filter cake washed with warm ethanol, adding to the reaction mixture in the second 200-gallon reactor. The agitator was started on the second 200-gallon reactor. The reactor contents were cooled to 29° C. 120 L of distilled water was slowly charged to the second reactor, with the water falling directly into the batch. The reactor contents were cooled to 8° C. The intermediate came out of solution and was held for 9.5 hours. The resultant slurry was centrifuged. 70 L of ethanol was charged to the reactor, cooled to 8° C. and the centrifuge cake was washed. The wet cake was unloaded into double polyethylene bags placed inside a paper lined drum. The yield was 123.5 kg of ethyl 8-(6-chloro-2H-1,3-benzoxazine-2,4(3H)-dionyl)octanoate.
400 L of purified water, USP and 45.4 kg NaOH pellets were charged to a 200 gallon glass-lined reactor and the agitator was set to 100-125 RPM. 123.5 kg of the ethyl 8-(6-chloro-21-1,3-benzoxazine-2,4(3H)-dionyl)octanoate wet cake was charged to the reactor. The charging port was closed. Cooling water applied to the condenser and the valve reactor overheads were set for atmospheric distillation. The reactor contents were heated to 98° C. and conversion monitored by HPLC. Initially (approximately 40 minutes) the reactor refluxed at 68° C., however, as the ethanol was removed (over 3 hours) by distillation the reactor temperature rose to 98° C. The starting material disappeared, as determined by HPLC, at approximately 4 hours. The reactor contents were cooled to 27° C. 150 L of purified water and USP were charged to an adjacent 200 gallon glass-lined reactor and the agitator was set to 100-125 RPM. 104 L of concentrated (12M) hydrochloric acid was charged to the reactor and cooled to 24° C. The saponified reaction mixture was slowly (over 5 hours) charged to the 200-gallon glass-lined reactor. The material (45 L and 45 L) was split into 2 reactors (200 gallons each) because of carbon dioxide evolution. The product precipitated out of solution. The reaction mixture was adjusted to a pH of 2.0-4.0 with 50% NaOH solution (2 L water, 2 kg NaOH). The reactor contents were cooled to 9-15° C. The intermediate crystallized out of solution over approximately 9 hours. The reactor slurry was centrifuged to isolate the intermediate. 50 L of purified water and USP were charged to a 200-gallon glass-lined reactor and this rinse was used to wash the centrifuge wet cake. The wet cake was unloaded into double polyethylene bags placed inside a plastic drum. The N-(5-chlorosalicyloyl)-8-aminocaprylic acid was dried under vacuum (27″ Hg) at 68° C. for 38 hours. The dry cake was unloaded into double polyethylene bags placed inside a 55-gallon, steel unlined, open-head drums with a desiccant bag placed on top. The dried isolated yield was 81 kg of N-(5-chlorosalicyloyl)-8-aminocaprylic acid.
EXAMPLE 27
Lyophilization of sCT/Sodium Salt of 5-CNAC for Tableting
The method of Example 19 was used to prepare lyophilized powder using 200 g of 5-CNAC as prepared in Example 26. The NaOH solution was made by dissolving 42 g of 100% NaOH into 2000 ml water. The slurry was stirred at room temperature, and vacuum filtered over a 0.45 micron filter. The pH of the solution containing the sodium salt of 5-CNAC was about 8.6. 200 mg of sCT was used.
EXAMPLE 28
Preparation of sCT/Sodium Salt of 5-CNAC Tablets
Tablets of the lyophilized powder prepared in Example 27 were prepared as follows.
An instrumented Carver press (Model C), available from Carver of Wabash, Ind., was used for tablet compression. The die used was 0.245″ in diameter. The top punch was flat-faced, bevel-edged and 0.245″ in diameter while the bottom punch was flat-faced, scored, bevel-edged and 0.245″ in diameter. The press was capable of measuring the upper and lower punch force as well as the displacement of the upper punch. A formula for direct compression was designed as shown in Table 8 below:
TABLE 8
Material
mg/tablet
mg/300 tablet batch
Lyophilized powder
100.2
30,060.0
of sCT/sodium salt of 5-CNAC
AC-DI-SOL ®
2.004
601.2
Magnesium Stearate
0.511
153.3
CAB-O-SIL ®
0.205
61.5
Total Weight (mg)
102.92
30,876.0
AC-DI-SOL® is croscarmellose sodium (NF, PH.Eur., JPE) and is available from FMC Corporation, Pharmaceutical Division, of Philadelphia, Pa.
CAB-O-SIL® is fumed silica and is available from Cabot Corporation, Tuscola, Ill.
The Ac-Di-Sol® and Cab-O-Sil® were weighed and transferred to a mixing bottle. The bottle was then closed and secured to the arm of a sustained release apparatus set at 25 rotations per minute (RPM). The apparatus was rotated for 5 minutes to mix. The lyophilized powder of 5-CNAC/sCT was then added to the AC-DI-SOL®/CAB-O-SIL® mixture geometrically with a two minute mixing cycle after each addition. Magnesium stearate was then added to the above mixture and mixing was continued for five minutes.
Approximately 103 mg of the above powder was then transferred to the die containing the lower punch. The powder was pressed down into the die using the upper punch. The upper punch was inserted and the punch die assembly was mounted onto the press. Compression was then performed. The upper punch was used to push the tablet out of the die.
EXAMPLE 29
Oral Delivery of sCT/Sodium Salt of 5-CNAC in Rats—Tablets
The tablets prepared in Example 28 were pulverized and hand packed into capsules at 13 mg/capsule. Untableted, lyophilized powder as prepared in Example 27 was hand packed into capsules at 13 mg/capsule. The capsules were dosed with 1 ml water to flush them down.
Following the procedure of Example 21, with the exception that the standard protocol for the EIA kit was followed instead of the modified version, rats were administered orally one capsule with 1 ml of water to flush the capsule down with the approximate amounts of sodium salt of 5-CNAC and sCT as set forth in Table 9 below. The results are also shown in Table 9.
TABLE 9
Oral Delivery of sCT/Sodium Salt of 5-CNAC in Rats
Mean Peak
Dose of Sodium
Serum
Salt of 5-CNAC
sCT Dose
sCT ± SD
Dosage form
(mg/kg)
(mg/kg)
(pg/ml)
(12a) tableted powder in
50*
100*
198 ± 132
capsule
(12b) untableted powder
50*
100*
197 ± 125
in capsule
*approximate dose due to variations in animal weight
EXAMPLE 30
Preparation of 5-CNAC
5-CNAC was made under similar conditions as in Example 26, in a laboratory environment.
EXAMPLE 31
Lyophilization of sCT/Sodium Salt of 5-CNAC
5-CNAC as prepared in Example 30 was formulated into a lyophilized powder with sCT as in Example 19 with 485 ml 0.2 N NaOH and 19.0072 g of 5-CNAC in a steam bath. The final volume was 505 ml. Four separate batches were prepared from 187, 138, 74 and 160 ml of the sodium salt 5-CNAC with 28, 48, 40 and 360 mg sCT, respectively. The estimated amounts of the sodium salt of 5-CNAC were 7, 5, 2.5 and 4.5 g, respectively.
EXAMPLE 32
Oral Delivery of sCT/Sodium Salt of 5-CNAC in Rats
According to the method of Example 21, with the exception that the standard protocol for the EIA kit was followed instead of the modified version, rats were administered orally one capsule of 13 mg lyophilized powder using one of the four batches prepared in Example 31, with 1 ml water to flush the capsule down. The approximate amounts of the sodium salt of 5-CNAC and sCT are set forth in Table 10 below. The results are shown in Table 10.
TABLE 10
Oral Delivery of sCT/Sodium Salt of 5-CNAC in Rats
Dose of Sodium
Salt of 5-CNAC
sCT Dose
Mean Peak
Dosage form
(mg/kg)
(mg/kg)
Serum sCT ± SD (pg/ml)
(15a) capsule
50*
100*
125 ± 153
(15b) capsule
50*
400*
178 ± 354
(15c) capsule
50*
800*
546 ± 586
(15d) capsule
50*
4000*
757 ± 1234
*approximate dose due to variations in animal weight
All patents, publications, applications, and test methods mentioned above are hereby incorporated by reference. Many variations of the present matter will suggest themselves to those skilled in the art in light of the above detailed description. All such obvious variations are within the patented scope of the appended claims.
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The inventors have discovered that the disodium salt of certain delivery agents has surprisingly greater efficacy for delivering active agents than the corresponding monosodium salt. Furthermore, the inventors have discovered that the disodium salts of these delivery agents form solvates with ethanol and hydrates with water. The delivery agents have the formula
wherein
R 1 , R 2 , R 3 , and R 4 are indepedently hydrogen, halogen, C 1 -C 4 alkyl, or C 1 -C 4 alkoxy; and R 5 is a substitued or unsubstituted C 2 -C 16 alkylene, substituted or unsubstituted C 2 -C 16 alkenylene, substituted or unsubstituted C 1 -C 12 alkyl(arylene), or substituted or unsubstituted aryl(C 1 -C 12 alkylene). The hydrates and solvates of present invention also have surprisingly greater efficacy for delivering active agents, such as heparin and calcitonin, than their corresponding monosodium salts and free acids. The present invention provides an alcohol solvate, such as ethanol solvate, of a disodium salt of a delivery agent of the formula above. The invention also provides a hydrate of a disodium salt of a delivery agent of the formula above. Preferred delivery agents include, but are not limited to, N-(5-chlorosalicyloyl)-8-aminocaprylic acid (5-CNAC), N-(10-[2-hydroxybenzoyl]amino)decanoic acid (SNAD), and sodium N-(8-[2-hydroxybenzoyl]amino)caprylate (SNAC). The invention also provides methods of preparing the disodium salt, ethanol solvate, and hydrate and compositions containing the disodium salt, ethanol solvate, and/or hydrate.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Ser. No. 61/740,790, filed on Dec. 21, 2012, and U.S. Provisional Application Ser. No. 61/909,612 filed on Nov. 27, 2013, the entire contents of which are hereby incorporated by reference.
FIELD
The present disclosure is directed to compositions and methods for making glass sheets capable of use in high performance video and information displays.
BACKGROUND
The production of liquid crystal displays, for example, active matrix liquid crystal display devices (AMLCDs) is very complex, and the properties of the substrate glass are extremely important. First and foremost, the glass substrates used in the production of AMLCD devices need to have their physical dimensions tightly controlled.
In the liquid crystal display field, thin film transistors (TFTs) based on poly-crystalline silicon are preferred because of their ability to transport electrons more effectively. Poly-crystalline based silicon transistors (p-Si) are characterized as having a higher mobility than those based on amorphous-silicon based transistors (a-Si). This allows the manufacture of smaller and faster transistors, which ultimately produces brighter and faster displays. One problem with p-Si based transistors is that their manufacture requires higher process temperatures than those employed in the manufacture of a-Si transistors. These temperatures range from 450° C. to 600° C. compared to the 350° C. peak temperatures typically employed in the manufacture of a-Si transistors. At these temperatures, most AMLCD glass substrates undergo a process known as compaction. Compaction, also referred to as thermal stability or dimensional change, is an irreversible dimensional change (shrinkage) in the glass substrate due to changes in the glass' fictive temperature. “Fictive temperature” is a concept used to indicate the structural state of a glass. Glass that is cooled quickly from a high temperature is said to have a higher fictive temperature because of the “frozen in” higher temperature structure. Glass that is cooled more slowly, or that is annealed by holding for a time near its annealing point, is said to have a lower fictive temperature. When a glass is held at an elevated temperature, the structure is allowed to relax its structure towards the heat treatment temperature. Since the glass substrate's fictive temperature is almost always above the relevant heat treatment temperatures in thin film transistor (TFT) processes, this structural relaxation causes a decrease in fictive temperature which therefore causes the glass to compact (shrink/densify).
It would be advantageous to minimize the level of compaction in the glass because compaction creates possible alignment issues during the display manufacturing process which in turn results in resolution problems in the finished display.
There are several approaches to minimize compaction in glass. One is to thermally pretreat the glass to create a fictive temperature similar to the one the glass will experience during the p-Si TFT manufacture. There are several difficulties with this approach. First, the multiple heating steps employed during the p-Si TFT manufacture create slightly different fictive temperatures in the glass that cannot be fully compensated for by this pretreatment. Second, the thermal stability of the glass becomes closely linked to the details of the p-Si TFT manufacture, which could mean different pretreatments for different end-users. Finally, pretreatment adds to processing costs and complexity.
Another approach is to increase the anneal point of the glass. Glasses with higher anneal will have a higher fictive temperature and will compact less than when subjected to the elevated temperatures associated with panel manufacture. The challenge with this approach, however, is the production of high annealing point glass that is cost effective. The main factors impacting cost are defects and asset lifetime. Higher anneal point glasses typically employ higher operational temperatures during their manufacture thereby reducing the lifetime of the fixed assets associated with glass manufacture.
Yet another approach involves slowing the cooling rate during manufacture. While such an approach has merits, some manufacturing techniques such as the fusion process result in rapid quenching of the glass sheet from the melt and a relatively high temperature structure is “frozen in”. While some controlled cooling is possible with such a manufacturing process, it is difficult to control.
SUMMARY
What is disclosed is a glass substrate with exceptional total pitch variability (TPV), as measured by three metrics: (1) compaction in the High Temperature Test Cycle (HTTC) less than 40 ppm, (2) compaction in the Low Temperature Test Cycle (LTTC) less than 5.5 ppm, and (3) stress relaxation rate consistent with less than 50% relaxed in the Stress Relaxation Test Cycle. By satisfying all three criteria with a single glass product, the substrate is assured of being acceptable for the highest resolution TFT cycles. Recent understanding of the underlying physics of glass relaxation has allowed the applicants to disclose glasses that satisfy all three criteria.
The present disclosure describes a glass sheet for use in high performance video or information displays meeting the following performance criteria: compaction in the low temperature test cycle of less than or equal to 5.5 ppm, compaction in the high temperature test cycle of less than or equal to 40 ppm, and less than 50% of an induced stress level in the stress relaxation test cycle. More specifically, the present disclosure provides glass compositions satisfying the above criteria and having a coefficient of thermal expansion compatible with silicon, being substantially alkali-free, arsenic free and antimony free. More specifically, the glasses of the present disclosure further exhibit densities less than 2.6 g/cc, transmission at 300 nm greater than 50% for a 0.5 mm thick sheet, and (MgO+CaO+SrO+BaO)/Al 2 O 3 less than 1.25.
In accordance with certain of its other aspects, the glasses possess high annealing points and high liquidus viscosities, thus reducing or eliminating the likelihood of devitrification on the forming mandrel. As a result of specific details of their composition, the disclosed glasses melt to good quality with very low levels of gaseous inclusions, and with minimal erosion to precious metals, refractories, and tin oxide electrode materials. Additional advantages will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the aspects described below. The advantages described below will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying figures, which are incorporated in and constitute a part of this specification, illustrate several aspects described below.
FIG. 1 is a graphical representation of the high thermal temperature cycle as described in the disclosure in terms of temperature over a set time period.
FIG. 2 is a graphical representation of the low thermal temperature cycle as described in the disclosure in terms of temperature over a set time period.
FIG. 3 is a graphical representation of compaction as measured in the High Temperature Test Cycle (HTTC) as a function of annealing points (in C) of studied glasses.
FIG. 4 is a graphical representation of compaction as measured in the Low Temperature Test Cycle (LTTC) as a function of annealing points (in C) of studied glasses.
FIG. 5 is a graphical representation of the percent of stress relaxed after the Stress Relaxations Test Cycle (SRTC)—60 minutes at 650 C—plotted as a function of annealing points (in C) of studied glasses. Glasses relaxing less than 50% of the stress are pointed out as key to this disclosure.
FIG. 6A is a graphical representation of glasses satisfying the compaction aspect of the present disclosure as contained in region “1”. Glasses located in region 1 also possess the stress relaxation rates embodied in the disclosure.
FIG. 6B is a graphical representation showing the enlarged region “1” from FIG. 6A .
DETAILED DESCRIPTION
Historically, panel makers have generally made either “large, low resolution” or “small, high resolution” displays. In both of these cases, glasses were held at elevated temperatures, causing the glass substrates to undergo a process known as compaction.
The amount of compaction exhibited by a glass substrate experiencing a given time/temperature profile can be described by the equation
T
f
(
t
)
-
T
=
(
T
f
(
t
=
0
)
-
T
)
exp
[
-
(
t
τ
(
T
)
)
b
]
where T f (t) is the fictive temperature of the glass as a function of time, T is the heat treatment temperature, T f (t=0) is the initial fictive temperature, b is the “stretching exponent”, and τ(T) is the relaxation time of the glass at the heat treatment temperature. While increasing the heat treatment temperature (T) lowers the “driving force” for compaction (i.e. making “T f (t=0)−T” a smaller quantity), it causes a much larger decrease in the relaxation time τ of the substrate. Relaxation time varies exponentially with temperature, causing an increase in the amount of compaction in a given time when the temperature is raised.
For the manufacturing of large, low-resolution displays using amorphous silicon (a-Si) based TFTs, the processing temperatures are relatively low (roughly 350° C. or less). These low temperatures, coupled with the loose dimensional stability requirements for low resolution displays, allow the use of low annealing point (T(ann)) glasses with higher fictive temperatures. The annealing point is defined as the temperature where the glass's viscosity is equal to 10 13.18 Poise. T(ann) is used as a simple metric to represent the low temperature viscosity of a glass, defined as the effective viscosity of the glass at a given temperature below the glass transition temperature. A higher “low temperature viscosity” causes a longer relaxation time through the Maxwell relationship
τ ( T ) ≈ η ( T ) G
where η is the viscosity and G is the shear modulus. Higher performance small, high-resolution displays have generally been made using poly-silicon based (p-Si) TFTs, which employ considerably higher temperatures than a-Si processes. Because of this, either higher annealing point or lower fictive temperature glasses were required to meet the compaction requirements for p-Si based TFTs. Considerable efforts have been made to create higher annealing point glasses compatible with existing manufacturing platforms or improve the thermal history of lower annealing point glasses to enable use in these processes and both paths have been shown to be adequate for previous generations of high performance displays. Recently, however, the p-Si based displays are now being made on even larger “gen size” sheets (many small displays on a single large sheet of glass) and the registry marks are placed much earlier in the TFT process. These two factors have forced the glass substrate to have even better high temperature compaction performance and have caused compaction in lower temperature steps to become a relevant (and perhaps even dominant) source of total pitch variability. Total pitch variability (TPV) refers to the variation in alignment of features (such as registry marks). TPV results from different sources during the processing of a large sheet of glass. As will be shown, adequate high temperature compaction does not necessarily translate to adequate low temperature performance or adequate TPV.
In order to reach higher mobilities in large displays, panel makers have begun making large, high-resolution displays using oxide thin film transistors (OxTFTs). While OxTFT processes are often run with peak temperatures similar to a-Si based TFTs (and often using the same equipment), the resolution requirements are considerably higher, which means low temperature compaction must be considerably improved relative to that of a-Si substrates. In addition to the tight requirements placed on low temperature compaction, the film stresses accumulated in the OxTFT processes have caused stress relaxation in the glass to become a major contributor to the overall TPV.
The applicants have realized that thermal cycles indicate TPV to be the most important description of dimensional stability, which incorporates compaction as well as the stress relaxation component. This coexistence of high and low temperature compaction in the same processes and the introduction of stress relaxation as a key substrate attribute in this new generation of high performance displays has shown all present commercially available substrates to be insufficient. Table 1 discloses glass compositions that can simultaneously manage all three aspects of TPV—low temperature compaction, high temperature compaction and stress relaxation.
Described herein are glasses that are substantially free of alkalis that possess high annealing points and, thus, good dimensional stability (i.e., low compaction) for use as TFT backplane substrates in amorphous silicon, oxide and low-temperature polysilicon TFT processes. The glasses of the present disclosure are capable of managing all three aspects of TPV—low temperature compaction, high temperature compaction and stress relaxation.
A high annealing point glass can prevent panel distortion due to compaction/shrinkage during thermal processing subsequent to manufacturing of the glass. In one embodiment, the disclosed glasses also possess unusually high liquidus viscosity, and thus a significantly reduced risk to devitrification at cold places in the forming apparatus. It is to be understood that while low alkali concentrations are generally desirable, in practice it may be difficult or impossible to economically manufacture glasses that are entirely free of alkalis. The alkalis in question arise as contaminants in raw materials, as minor components in refractories, etc., and can be very difficult to eliminate entirely. Therefore, the disclosed glasses are considered substantially free of alkalis if the total concentration of the alkali elements Li 2 O, Na 2 O, and K 2 O is less than about 0.1 mole percent (mol %).
In one aspect, the substantially alkali-free glasses have annealing points greater than about 765° C., preferably greater than 775° C., and more preferably greater than 785° C. Such high annealing points result in low rates of relaxation—and hence comparatively small amounts of dimensional change—for the disclosed glass to be used as backplane substrate in a low-temperature polysilicon process. In another aspect, the temperature of the disclosed glasses at a viscosity of about 35,000 poise (T 35k ) is less than about 1310° C. The liquidus temperature of a glass (T liq ) is the highest temperature above which no crystalline phases can coexist in equilibrium with the glass. In another aspect, the viscosity corresponding to the liquidus temperature of the glass is greater than about 150,000 poise, more preferably greater than 200,000 poise, and most preferably greater than 250,000 poise. In another aspect, the disclosed glass is characterized in that T 35k −T liq >0.25T 35k −225° C. This ensures minimum tendency to devitrify on the forming mandrel of the fusion process.
In one aspect, the substantially alkali-free glass comprises in mole percent on an oxide basis:
SiO 2 50-85 Al 2 O 3 0-20 B 2 O 3 0-10 MgO 0-20 CaO 0-20 SrO 0-20 BaO 0-20
wherein
0.9≦(MgO+CaO+SrO+BaO)/Al 2 O 3 ≦3,
where Al 2 O 3 , MgO, CaO, SrO, BaO represent the mole percents of the respective oxide components.
In a further aspect, the substantially alkali-free glass comprises in mole percent on an oxide basis:
SiO 2 68-74 Al 2 O 3 10-13 B 2 O 3 0-5 MgO 0-6 CaO 4-9 SrO 1-8 BaO 0-5
wherein
1.05≦(MgO+CaO+SrO+BaO)/Al 2 O 3 ≦1.2,
where Al 2 O 3 , MgO, CaO, SrO, BaO represent the mole percents of the respective oxide components.
In one aspect, the disclosed glass includes a chemical fining agent. Such fining agents include, but are not limited to, SnO 2 , As 2 O 3 , Sb 2 O 3 , F, Cl and Br, and in which the concentrations of the chemical fining agents are kept at a level of 0.5 mol % or less. Chemical fining agents may also include CeO 2 , Fe 2 O 3 , and other oxides of transition metals, such as MnO 2 . These oxides may introduce color to the glass via visible absorptions in their final valence state(s) in the glass, and thus their concentration is preferably kept at a level of 0.2 mol % or less.
In one aspect, the disclosed glasses are manufactured into sheet via the fusion process. The fusion draw process results in a pristine, fire-polished glass surface that reduces surface-mediated distortion to high resolution TFT backplanes and color filters. The downdraw sheet drawing processes and, in particular, the fusion process described in U.S. Pat. Nos. 3,338,696 and 3,682,609 (both to Dockerty), which are incorporated by reference, can be used herein. Compared to other forming processes, such as the float process, the fusion process is preferred for several reasons. First, glass substrates made from the fusion process do not require polishing. Current glass substrate polishing is capable of producing glass substrates having an average surface roughness greater than about 0.5 nm (Ra), as measured by atomic force microscopy. The glass substrates produced by the fusion process have an average surface roughness as measured by atomic force microscopy of less than 0.5 nm. The substrates also have an average internal stress as measured by optical retardation which is less than or equal to 150 psi.
While the disclosed glasses are compatible with the fusion process, they may also be manufactured into sheets or other ware through less demanding manufacturing processes. Such processes include slot draw, float, rolling, and other sheet-forming processes known to those skilled in the art.
Relative to these alternative methods for creating sheets of glass, the fusion process as discussed above is capable of creating very thin, very flat, very uniform sheets with a pristine surface. Slot draw also can result in a pristine surface, but due to change in orifice shape over time, accumulation of volatile debris at the orifice-glass interface, and the challenge of creating an orifice to deliver truly flat glass, the dimensional uniformity and surface quality of slot-drawn glass are generally inferior to fusion-drawn glass. The float process is capable of delivering very large, uniform sheets, but the surface is substantially compromised by contact with the float bath on one side, and by exposure to condensation products from the float bath on the other side. This means that float glass must be polished for use in high performance display applications.
Unfortunately, and in unlike the float process, the fusion process results in rapid cooling of the glass from high temperature, and this results in a high fictive temperature T f : the fictive temperature can be thought of as representing the discrepancy between the structural state of the glass and the state it would assume if fully relaxed at the temperature of interest. We consider now the consequences of reheating a glass with a glass transition temperature T g to a process temperature T p such that T p <T g ≦T f . Since T p <T f , the structural state of the glass is out of equilibrium at T p , and the glass will spontaneously relax toward a structural state that is in equilibrium at T p . The rate of this relaxation scales inversely with the effective viscosity of the glass at T p , such that high viscosity results in a slow rate of relaxation, and a low viscosity results in a fast rate of relaxation. The effective viscosity varies inversely with the fictive temperature of the glass, such that a low fictive temperature results in a high viscosity, and a high fictive temperature results in a comparatively low viscosity. Therefore, the rate of relaxation at T p scales directly with the fictive temperature of the glass. A process that introduces a high fictive temperature results in a comparatively high rate of relaxation when the glass is reheated at T p .
One means to reduce the rate of relaxation at T p is to increase the viscosity of the glass at that temperature. The annealing point of a glass represents the temperature at which the glass has a viscosity of 10 13.2 poise. As temperature decreases below the annealing point, the viscosity of the supercooled melt increases. At a fixed temperature below T g , a glass with a higher annealing point has a higher viscosity than a glass with a lower annealing point. Therefore, to increase the viscosity of a substrate glass at T p , one might choose to increase its annealing point. Unfortunately, it is generally the case that the composition changes necessary to increase the annealing point also increase viscosity at all other temperature. In particular, the fictive temperature of a glass made by the fusion process corresponds to a viscosity of about 10 11 -10 12 poise, so an increase in annealing point for a fusion-compatible glass generally increases its fictive temperature as well. For a given glass, higher fictive temperature results in lower viscosity at temperature below T g , and thus increasing fictive temperature works against the viscosity increase that would otherwise be obtained by increasing the annealing point. To see a substantial change in the rate of relaxation at T p , it is generally necessary to make relatively large changes in annealing point. An aspect of the disclosed glass is that it has an annealing point greater than about 765° C., in another aspect greater than 775° C., and in yet another aspect greater than 785° C. Such high annealing points results in acceptably low rates of thermal relaxation during low-temperature TFT processing, e.g., typical low-temperature polysilicon rapid thermal anneal cycles.
In addition to its impact on fictive temperature, increasing annealing point also increases temperatures throughout the melting and forming system, particularly the temperatures on the isopipe as utilized as the forming apparatus in the fusion process. For example, Eagle XG® and Lotus™ (Corning Incorporated, Corning, N.Y.) have annealing points that differ by about 50° C., and the temperature at which they are delivered to the isopipe also differ by about 50° C. When held for extended periods of time above about 1310° C., zircon refractory shows thermal creep, and this can be accelerated by the weight of the isopipe itself plus the weight of the glass on the isopipe. A second aspect of the disclosed glasses is that their delivery temperatures are less than 1310° C. Such delivery temperatures permit extended manufacturing campaigns without replacing the isopipe.
In manufacturing trials of glasses with high annealing points and delivery temperatures below 1310° C., it was discovered that they showed a greater tendency toward devitrification on the root of the isopipe and—especially—the edge directors relative to glasses with lower annealing points. Careful measurement of the temperature profile on the isoipe showed that the edge director temperatures were much lower relative to the center root temperature than had been anticipated due to radiative heat loss. The edge directors typically must be maintained at a temperature below the center root temperature in order to ensure that the glass is viscous enough as it leaves the root that it puts the sheet in between the edge directors under tension, thus maintaining a flat shape. As they are at either end of the isopipe, the edge directors are difficult to heat, and thus the temperature difference between the center of the root and the edge directors may differ by 50° or more.
Since radiative heat loss increases with temperature, and since high annealing point glasses generally are formed at higher temperatures than lower annealing point glasses, the temperature difference between the center root and the edge director generally increases with the annealing point of the glass. This has a direct consequence as regards the tendency of a glass to form devitrification products on the isopipe or edge directors. The liquidus temperature of a glass is defined as the highest temperature at which a crystalline phase would appear if a glass were held indefinitely at that temperature. The liquidus viscosity is the viscosity of a glass at the liquidus temperature. To completely avoid devitrification on an isopipe, it is desirable that the liquidus viscosity be high enough to ensure that glass is no longer on the isopipe refractory or edge director material at or near the liquidus temperature.
In practice, few alkali-free glasses have liquidus viscosities of the desired magnitude. Experience with substrate glasses suitable for amorphous silicon applications (e.g., Eagle XG®) indicated that edge directors could be held continuously at temperatures up to 60° below the liquidus temperature of certain alkali-free glasses. While it was understood that glasses with higher annealing points would require higher forming temperatures, it was not anticipated that the edge directors would be so much cooler relative to the center root temperature. A useful metric for keeping track of this effect is the difference between the delivery temperature onto the isopipe and the liquidus temperature of the glass, T liq . In the fusion process, it is generally desirable to deliver glass at about 35,000 poise, and the temperature corresponding to a viscosity of 35,000 poise is conveniently represented as T 35k . For a particular delivery temperature, it is always desirable to make T 35k −T liq as large possible, but for an amorphous silicon substrate such as Eagle XG®, it is found that extended manufacturing campaigns can be conducted if T 35k −T liq is about 80° or more. As temperature increases, T 35k −T liq must increase as well, such that for T 35k near 1300°, it is desirable that T 35k −T liq at least about 100°. The minimum useful value for T 35k −T liq varies approximately linearly with temperature from about 1200° C. to about 1320° C., and can be expressed as
minimum T 35k −T liq =0.25 T 35k −225,
where all temperatures are in ° C. Thus, a further aspect of the disclosed glass is that T 35k −T liq >0.25T 35k −225° C.
In addition to this criterion, the fusion process requires a glass with a high liquidus viscosity. This is necessary so as to avoid devitrification products at interfaces with glass and to minimize visible devitrification products in the final glass. For a given glass compatible with fusion for a particular sheet size and thickness, adjusting the process so as to manufacture wider sheet or thicker sheet generally results in lower temperatures at either end of the isopipe (the forming mandrel for the fusion process). Thus, disclosed glasses with higher liquidus viscosities provide greater flexibility for manufacturing via the fusion process.
In tests of the relationship between liquidus viscosity and subsequent devitrification tendencies in the fusion process, it has been observed that high delivery temperatures such as those of the disclosed glasses generally require higher liquidus viscosities for long-term production than would be the case for typical AMLCD substrate compositions with lower annealing points. While not wishing to be bound by theory, this requirement appears to arise from accelerated rates of crystal growth as temperature increases. Fusion is essentially an isoviscous process, so a more viscous glass at some fixed temperature must be formed by fusion at higher temperature than a less viscous glass. While some degree of undercooling (cooling below the liquidus temperature) can be sustained for extended periods in a glass at lower temperature, crystal growth rates increase with temperature, and thus more viscous glasses grow an equivalent, unacceptable amount of devitrification products in a shorter period of time than less viscous glasses. Depending on where they form, devitrification products can compromise forming stability, and introduce visible defects into the final glass.
To be formed by the fusion process, it is desirable that the disclosed glass compositions have a liquidus viscosity greater than or equal to 200,000 poises, more preferably greater than or equal to 250,000 poises, higher liquidus viscosities being preferable. A surprising result is that throughout the range of the disclosed glasses, it is possible to obtain a liquidus temperature low enough, and a viscosity high enough, such that the liquidus viscosity of the glass is unusually high compared to compositions outside of the disclosed range.
Of course, the present disclosure is not limited to use with the fusion process and accordingly for the float process, the liquidus viscosity conditions as well as other fusion specific criteria described above would not be necessary, thereby extending the composition windows for those processes.
In the glass compositions described herein, SiO 2 serves as the basic glass former. The SiO 2 content may be from 50-80 mole percent. In certain aspects, the concentration of SiO 2 can be greater than 68 mole percent in order to provide the glass with a density and chemical durability suitable for a flat panel display glass (e.g., an AMLCD glass), and a liquidus temperature (liquidus viscosity), which allows the glass to be formed by a downdraw process (e.g., a fusion process). In one embodiment, the SiO 2 concentration may be less than or equal to about 74 mole percent to allow batch materials to be melted using conventional, high volume, melting techniques, e.g., Joule melting in a refractory melter. As the concentration of SiO 2 increases, the 200 poise temperature (melting temperature) generally rises. In various applications, the SiO 2 concentration is adjusted so that the glass composition has a melting temperature less than or equal to 1,725° C. In one aspect, the SiO 2 concentration is between 70 and 73 mole percent.
Al 2 O 3 is another glass former used to make the glasses described herein. In one embodiment, the Al 2 O 3 concentration is 0-20 mole percent. In another embodiment and as a consideration for glasses made by the fusion process, an Al 2 O 3 concentration greater than or equal to 10 mole percent provides the glass with a low liquidus temperature and high viscosity, resulting in a high liquidus viscosity. The use of at least 10 mole percent Al 2 O 3 also improves the glass's annealing point and modulus. For embodiments having the ratio (MgO+CaO+SrO+BaO)/Al 2 O 3 greater than or equal to 1.05, it is desirable to keep the Al 2 O 3 concentration below about 13 mole percent. In one aspect, the Al 2 O 3 concentration is between 10 and 13 mole percent.
B 2 O 3 is both a glass former and a flux that aids melting and lowers the melting temperature. Its impact on liquidus temperature is at least as great as its impact on viscosity, so increasing B 2 O 3 can be used to increase the liquidus viscosity of a glass. In one embodiment, the B 2 O 3 content is 0-10 mole percent, and in another embodiment between 0-6 mole percent. In another embodiment, the glass compositions described herein have B 2 O 3 concentrations that are equal to or greater than 1 mole percent. As discussed above with regard to SiO 2 , glass durability is very important for LCD applications. Durability can be controlled somewhat by elevated concentrations of alkaline earth oxides, and significantly reduced by elevated B 2 O 3 content. Annealing point decreases as B 2 O 3 increases, so it is desirable to keep B 2 O 3 content low relative to its typical concentration in amorphous silicon substrates. Thus in one aspect, the glasses described herein have B 2 O 3 concentrations that are between 1 and 5 mole percent. In another aspect, the glasses have a B 2 O 3 content between 2 and 4.5 mol percent. In yet another aspect, the glasses of the present invention have a B 2 O 3 content of between 2.5 and 4.5 mol percent.
The Al 2 O 3 and B 2 O 3 concentrations can be selected as a pair to increase annealing point, increase modulus, improve durability, reduce density, and reduce the coefficient of thermal expansion (CTE), while maintaining the melting and forming properties of the glass.
For example, an increase in B 2 O 3 and a corresponding decrease in Al 2 O 3 can be helpful in obtaining a lower density and CTE, while an increase in Al 2 O 3 and a corresponding decrease in B 2 O 3 can be helpful in increasing annealing point, modulus, and durability, provided that in some embodiments where (MgO+CaO+SrO+BaO)/Al 2 O 3 control is sought, increase in Al 2 O 3 does not reduce the (MgO+CaO+SrO+BaO)/Al 2 O 3 ratio below about 0.9 in one embodiment and 1.05 in another embodiment. For (MgO+CaO+SrO+BaO)/Al 2 O 3 ratios below about 1.0, it may be difficult or impossible to remove gaseous inclusions from the glass due to late-stage melting of the silica raw material. Furthermore, when (MgO+CaO+SrO+BaO)/Al 2 O 3 ≦1.05, mullite, an aluminosilicate crystal, can appear as a liquidus phase. Once mullite is present as a liquidus phase, the composition sensitivity of liquidus increases considerably, and mullite devitrification products both grow very quickly and are very difficult to remove once established. Thus in one aspect, the glasses described herein have (MgO+CaO+SrO+BaO)/Al 2 O 3 ≧1.05. An upper end of (MgO+CaO+SrO+BaO)/Al 2 O 3 may be as high as 3, depending on the forming process, but in one embodiment and as described immediately below, are less than or equal to 1.2. In another embodiment, less than or equal to 1.6; and in yet another embodiment, less than or equal to 1.4.
In addition to the glass formers (SiO 2 , Al 2 O 3 , and B 2 O 3 ), the glasses described herein also include alkaline earth oxides. In one aspect, at least three alkaline earth oxides are part of the glass composition, e.g., MgO, CaO, and BaO, and, optionally, SrO. The alkaline earth oxides provide the glass with various properties important to melting, fining, forming, and ultimate use. Accordingly, to improve glass performance in these regards, in one aspect, the (MgO+CaO+SrO+BaO)/Al 2 O 3 ratio is greater than or equal to 1.05. As this ratio increases, viscosity tends to increase more strongly than liquidus temperature, and thus it is increasingly difficult to obtain suitably high values for T 35k −T liq . Thus in another aspect, ratio (MgO+CaO+SrO+BaO)/Al 2 O 3 is less than or equal to 1.2.
For certain embodiments of this invention, the alkaline earth oxides may be treated as what is in effect a single compositional component. This is because their impact upon viscoelastic properties, liquidus temperatures and liquidus phase relationships are qualitatively more similar to one another than they are to the glass forming oxides SiO 2 , Al 2 O 3 and B 2 O 3 . However, the alkaline earth oxides CaO, SrO and BaO can form feldspar minerals, notably anorthite (CaAl 2 Si 2 O 8 ) and celsian (BaAl 2 Si 2 O 8 ) and strontium-bearing solid solutions of same, but MgO does not participate in these crystals to a significant degree. Therefore, when a feldspar crystal is already the liquidus phase, a superaddition of MgO may serves to stabilize the liquid relative to the crystal and thus lower the liquidus temperature. At the same time, the viscosity curve typically becomes steeper, reducing melting temperatures while having little or no impact on low-temperature viscosities. In this sense, the addition of small amounts of MgO benefits melting by reducing melting temperatures, benefits forming by reducing liquidus temperatures and increasing liquidus viscosity, while preserving high annealing point and, thus, low compaction.
Glasses for use in AMLCD applications should have CTEs (0-300° C.) in the range of 28-42×10 −7 /° C., preferably, 30-40×10 −7 /° C., and more preferably, 32-38×10 −7 /° C., or in other embodiments 33-37×10 −7 /° C. For certain applications, density is important as weight of the final display may be an important attribute.
Calcium oxide present in the glass composition can produce low liquidus temperatures (high liquidus viscosities), high annealing points and moduli, and CTE's in the most desired ranges for flat panel applications, specifically, AMLCD applications. It also contributes favorably to chemical durability, and compared to other alkaline earth oxides, it is relatively inexpensive as a batch material. However, at high concentrations, CaO increases the density and CTE. Furthermore, at sufficiently low SiO 2 concentrations, CaO may stabilize anorthite, thus decreasing liquidus viscosity. Accordingly, in one aspect, the CaO concentration can be greater than or equal 0 to 20 mole percent. In another aspect, the CaO concentration of the glass composition is between about 4 and 9 mole percent. In another aspect, the CaO concentration of the glass composition is between about 4.5 and 6 mole percent.
SrO and BaO can both contribute to low liquidus temperatures (high liquidus viscosities) and, thus, the glasses described herein will typically contain at least both of these oxides. However, the selection and concentration of these oxides are selected in order to avoid an increase in CTE and density and a decrease in modulus and annealing point. For glasses made by a downdraw process, the relative proportions of SrO and BaO can be balanced so as to obtain a suitable combination of physical properties and liquidus viscosity.
On top of these considerations, the glasses are preferably formable by a downdraw process, e.g., a fusion process, which means that the glass' liquidus viscosity needs to be relatively high. Individual alkaline earths play an important role in this regard since they can destabilize the crystalline phases that would otherwise form. BaO and SrO are particularly effective in controlling the liquidus viscosity and are included in the glasses of the invention for at least this purpose. As illustrated in the examples presented below, various combinations of the alkaline earths will produce glasses having high liquidus viscosities, with the total of the alkaline earths satisfying the RO/Al 2 O 3 ratio constraints needed to achieve low melting temperatures, high annealing points, and suitable CTE's.
The glass compositions are generally alkali free; however, the glasses can contain some alkali contaminants. In the case of AMLCD applications, it is desirable to keep the alkali levels below 0.1 mole percent to avoid having a negative impact on thin film transistor (TFT) performance through diffusion of alkali ions from the glass into the silicon of the TFT. As used herein, an “alkali-free glass” is a glass having a total alkali concentration which is less than or equal to 0.1 mole percent, where the total alkali concentration is the sum of the Na 2 O, K 2 O, and Li 2 O concentrations. In one aspect, the total alkali concentration is less than or equal to 0.1 mole percent.
On an oxide basis, the glass compositions described herein can have one or more or all of the following compositional characteristics: (i) an As 2 O 3 concentration of at most 0.05 mole percent; (ii) an Sb 2 O 3 concentration of at most 0.05 mole percent; (iii) a SnO 2 concentration of at most 0.25 mole percent.
As 2 O 3 is an effective high temperature fining agent for AMLCD glasses, and in some aspects described herein, As 2 O 3 is used for fining because of its superior fining properties. However, As 2 O 3 is poisonous and requires special handling during the glass manufacturing process. Accordingly, in certain aspects, fining is performed without the use of substantial amounts of As 2 O 3 , i.e., the finished glass has at most 0.05 mole percent As 2 O 3 . In one aspect, no As 2 O 3 is purposely used in the fining of the glass. In such cases, the finished glass will typically have at most 0.005 mole percent As 2 O 3 as a result of contaminants present in the batch materials and/or the equipment used to melt the batch materials.
Although not as toxic as As 2 O 3 , Sb 2 O 3 is also poisonous and requires special handling. In addition, Sb 2 O 3 raises the density, raises the CTE, and lowers the annealing point in comparison to glasses that use As 2 O 3 or SnO 2 as a fining agent. Accordingly, in certain aspects, fining is performed without the use of substantial amounts of Sb 2 O 3 , i.e., the finished glass has at most 0.05 mole percent Sb 2 O 3 . In another aspect, no Sb 2 O 3 is purposely used in the fining of the glass. In such cases, the finished glass will typically have at most 0.005 mole percent Sb 2 O 3 as a result of contaminants present in the batch materials and/or the equipment used to melt the batch materials.
Compared to As 2 O 3 and Sb 2 O 3 fining, tin fining (i.e., SnO 2 fining) is less effective, but SnO 2 is a ubiquitous material that has no known hazardous properties. Also, for many years, SnO 2 has been a component of AMLCD glasses through the use of tin oxide electrodes in the Joule melting of the batch materials for such glasses. The presence of SnO 2 in AMLCD glasses has not resulted in any known adverse effects in the use of these glasses in the manufacture of liquid crystal displays. However, high concentrations of SnO 2 are not preferred as this can result in the formation of crystalline defects in AMLCD glasses. In one aspect, the concentration of SnO 2 in the finished glass is less than or equal to 0.25 mole percent.
Tin fining can be used alone or in combination with other fining techniques if desired. For example, tin fining can be combined with halide fining, e.g., bromine fining. Other possible combinations include, but are not limited to, tin fining plus sulfate, sulfide, cerium oxide, mechanical bubbling, and/or vacuum fining. It is contemplated that these other fining techniques can be used alone. In certain aspects, maintaining the (MgO+CaO+SrO+BaO)/Al 2 O 3 ratio and individual alkaline earth concentrations within the ranges discussed above makes the fining process easier to perform and more effective.
As described, the glasses described herein can be manufactured using various techniques known in the art. In one aspect, the glasses are made using a manufacturing process by which a population of 50 sequential glass sheets are produced from the melted and fined batch materials and has an average gaseous inclusion level of less than 0.10 gaseous inclusions/cubic centimeter, where each sheet in the population has a volume of at least 500 cubic centimeters.
In one embodiment, the glasses of the present disclosure exhibit transmission at 300 nm of greater than 50% for a 0.5 mm thick article. In another embodiment, the glasses of the present disclosure exhibit transmission at 300 nm of greater than 60% for a 0.5 mm thick article. In one embodiment, the glasses of the present disclosure exhibit densities of between 2.3 and 2.6 g/cc. In another embodiment, the glasses of the present disclosure exhibit densities of less than 2.58 g/cc. In one embodiment, the glass articles of the present invention exhibit an internal fusion line indicating their method of manufacture by a fusion downdraw process. In one embodiment, the Young's modulus is between 70-90 GPa. In another embodiment, the Young's modulus is between 75-85 GPa.
In one embodiment, the glasses of the present disclosure will have a CTE less than 36×10 −7 /° C., a density less than 2.6 g/cc, at 200 poise temperature of less than 1700° C., a T 35k of less than 1350° C., and a T 35k −T liq greater than 100° C.
EXAMPLES
The following examples are set forth below to illustrate the methods and results according to the disclosed subject matter. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to illustrate representative methods and results. These examples are not intended to exclude equivalents and variations of the present invention which are apparent to one skilled in the art.
Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some errors and deviations should be accounted for. Unless indicated otherwise, temperature is in ° C. or is at ambient temperature, and pressure is at or near atmospheric. The compositions themselves are given in mole percent on an oxide basis and have been normalized to 100%. There are numerous variations and combinations of reaction conditions, e.g., component concentrations, temperatures, pressures and other reaction ranges and conditions that can be used to optimize the product purity and yield obtained from the described process. Only reasonable and routine experimentation will be required to optimize such process conditions.
The glass properties set forth in Table 1 were determined in accordance with techniques conventional in the glass art. Thus, the linear coefficient of thermal expansion (CTE) over the temperature range 25-300° C. is expressed in terms of x 10 −7 /° C. and the annealing point is expressed in terms of ° C. These were determined from fiber elongation techniques (ASTM references E228-85 and C336, respectively). The density in terms of grams/cm 3 was measured via the Archimedes method (ASTM C693). The melting temperature in terms of ° C. (defined as the temperature at which the glass melt demonstrates a viscosity of 200 poises) was calculated employing a Fulcher equation fit to high temperature viscosity data measured via rotating cylinders viscometry (ASTM C965-81).
The liquidus temperature of the glass in terms of ° C. was measured using the standard gradient boat liquidus method of ASTM C829-81. This involves placing crushed glass particles in a platinum boat, placing the boat in a furnace having a region of gradient temperatures, heating the boat in an appropriate temperature region for 24 hours, and determining by means of microscopic examination the highest temperature at which crystals appear in the interior of the glass. More particularly, the glass sample is removed from the Pt boat in one piece, and examined using polarized light microscopy to identify the location and nature of crystals which have formed against the Pt and air interfaces, and in the interior of the sample. Because the gradient of the furnace is very well known, temperature vs. location can be well estimated, within 5-10° C. The temperature at which crystals are observed in the internal portion of the sample is taken to represent the liquidus of the glass (for the corresponding test period). Testing is sometimes carried out at longer times (e.g. 72 hours), in order to observe slower growing phases. The temperature corresponding to 200 poise and the viscosity at the liquidus (in poises) were determined from fits to high viscosity data using the Vogel-Fulcher-Tammann equation,
log(η)= A+B /( T−T o )
in which T is temperature and A, B and T o are fitting parameters. To determine liquidus viscosity, the liquidus temperature is used as the value for T. Young's modulus values in terms of GPa were determined using a resonant ultrasonic spectroscopy technique of the general type set forth in ASTM E1875-00e1.
As can be seen in Table 1, the exemplary glasses have density, CTE, annealing point and Young's modulus values that make the glasses suitable for display applications, such as AMLCD substrate applications, and more particularly for low-temperature polysilicon and oxide thin film transistor applications. Although not shown in Table 1, the glasses have durabilities in acid and base media that are similar to those obtained from commercial AMLCD substrates, and thus are appropriate for AMLCD applications. The exemplary glasses can be formed using downdraw techniques, and in particular are compatible with the fusion process, via the aforementioned criteria.
The exemplary glasses of Table 1 were prepared using a commercial sand as a silica source, milled such that 90% by weight passed through a standard U.S. 100 mesh sieve. Alumina was the alumina source, periclase was the source for MgO, limestone the source for CaO, strontium carbonate, strontium nitrate or a mix thereof was the source for SrO, barium carbonate was the source for BaO, and tin (IV) oxide was the source for SnO 2 . The raw materials were thoroughly mixed, loaded into a platinum vessel suspended in a furnace heated by silicon carbide glowbars, melted and stirred for several hours at temperatures between 1600 and 1650° C. to ensure homogeneity, and delivered through an orifice at the base of the platinum vessel. The resulting patties of glass were annealed at or near the annealing point, and then subjected to various experimental methods to determine physical, viscous and liquidus attributes.
These methods are not unique, and the glasses of Table 1 can be prepared using standard methods well-known to those skilled in the art. Such methods include a continuous melting process, such as would be performed in a continuous melting process, wherein the melter used in the continuous melting process is heated by gas, by electric power, or combinations thereof.
Raw materials appropriate for producing the disclosed glass include commercially available sands as sources for SiO 2 ; alumina, aluminum hydroxide, hydrated forms of alumina, and various aluminosilicates, nitrates and halides as sources for Al 2 O 3 ; boric acid, anhydrous boric acid and boric oxide as sources for B 2 O 3 ; periclase, dolomite (also a source of CaO), magnesia, magnesium carbonate, magnesium hydroxide, and various forms of magnesium silicates, aluminosilicates, nitrates and halides as sources for MgO; limestone, aragonite, dolomite (also a source of MgO), wolastonite, and various forms of calcium silicates, aluminosilicates, nitrates and halides as sources for CaO; and oxides, carbonates, nitrates and halides of strontium and barium. If a chemical fining agent is desired, tin can be added as SnO 2 , as a mixed oxide with another major glass component (e.g., CaSnO 3 ), or in oxidizing conditions as SnO, tin oxalate, tin halide, or other compounds of tin known to those skilled in the art.
The glasses in Table 1 contain SnO 2 as a fining agent, but other chemical fining agents could also be employed to obtain glass of sufficient quality for TFT substrate applications. For example, the disclosed glasses could employ any one or combinations of As 2 O 3 , Sb 2 O 3 , CeO 2 , Fe 2 O 3 , and halides as deliberate additions to facilitate fining, and any of these could be used in conjunction with the SnO 2 chemical fining agent shown in the examples. Of these, As 2 O 3 and Sb 2 O 3 are generally recognized as hazardous materials, subject to control in waste streams such as might be generated in the course of glass manufacture or in the processing of TFT panels. It is therefore desirable to limit the concentration of As 2 O 3 and Sb 2 O 3 individually or in combination to no more than 0.005 mol %.
In addition to the elements deliberately incorporated into the disclosed glasses, nearly all stable elements in the periodic table are present in glasses at some level, either through low levels of contamination in the raw materials, through high-temperature erosion of refractories and precious metals in the manufacturing process, or through deliberate introduction at low levels to fine tune the attributes of the final glass. For example, zirconium may be introduced as a contaminant via interaction with zirconium-rich refractories. As a further example, platinum and rhodium may be introduced via interactions with precious metals. As a further example, iron may be introduced as a tramp in raw materials, or deliberately added to enhance control of gaseous inclusions. As a further example, manganese may be introduced to control color or to enhance control of gaseous inclusions. As a further example, alkalis may be present as a tramp component at levels up to about 0.1 moi % for the combined concentration of Li 2 O, Na 2 O and K 2 O.
Hydrogen is inevitably present in the form of the hydroxyl anion, OH − , and its presence can be ascertained via standard infrared spectroscopy techniques. Dissolved hydroxyl ions significantly and nonlinearly impact the annealing point of the disclosed glasses, and thus to obtain the desired annealing point it may be necessary to adjust the concentrations of major oxide components so as to compensate. Hydroxyl ion concentration can be controlled to some extent through choice of raw materials or choice of melting system. For example, boric acid is a major source of hydroxyls, and replacing boric acid with boric oxide can be a useful means to control hydroxyl concentration in the final glass. The same reasoning applies to other potential raw materials comprising hydroxyl ions, hydrates, or compounds comprising physisorbed or chemisorbed water molecules. If burners are used in the melting process, then hydroxyl ions can also be introduced through the combustion products from combustion of natural gas and related hydrocarbons, and thus it may be desirable to shift the energy used in melting from burners to electrodes to compensate. Alternatively, one might instead employ an iterative process of adjusting major oxide components so as to compensate for the deleterious impact of dissolved hydroxyl ions.
Sulfur is often present in natural gas, and likewise is a tramp component in many carbonate, nitrate, halide, and oxide raw materials. In the form of SO 2 , sulfur can be a troublesome source of gaseous inclusions. The tendency to form SO 2 -rich defects can be managed to a significant degree by controlling sulfur levels in the raw materials, and by incorporating low levels of comparatively reduced multivalent cations into the glass matrix. While not wishing to be bound, by theory, it appears that SO 2 -rich gaseous inclusions arise primarily through reduction of sulfate (SO 4 = ) dissolved in the glass. The elevated barium concentrations of the disclosed glasses appear to increase sulfur retention in the glass in early stages of melting, but as noted above, barium is required to obtain low liquidus temperature, and hence high T 35k −T liq and high liquidus viscosity. Deliberately controlling sulfur levels in raw materials to a low level is a useful means of reducing dissolved sulfur (presumably as sulfate) in the glass. In particular, sulfur is preferably less than 200 ppm by weight in the batch materials, and more preferably less than 100 ppm by weight in the batch materials.
Reduced multivalents can also be used to control the tendency of the disclosed glasses to form SO 2 blisters. While not wishing to be bound to theory, these elements behave as potential electron donors that suppress the electromotive force for sulfate reduction. Sulfate reduction can be written in terms of a half reaction such as
SO 4 = →SO 2 +O 2 +2 e−
where e− denotes an electron. The “equilibrium constant” for the half reaction is
K eq =[SO 2 ][O 2 ][e−] 2 /[SO 4 = ]
where the brackets denote chemical activities. Ideally one would like to force the reaction so as to create sulfate from SO 2 , O 2 and 2e−. Adding nitrates, peroxides, or other oxygen-rich raw materials may help, but also may work against sulfate reduction in the early stages of melting, which may counteract the benefits of adding them in the first place. SO 2 has very low solubility in most glasses, and so is impractical to add to the glass melting process. Electrons may be “added” through reduced multivalents. For example, an appropriate electron-donating half reaction for ferrous iron (Fe 2+ ) is expressed as
2Fe 2+ →2Fe 3+ +2 e−
This “activity” of electrons can force the sulfate reduction reaction to the left, stabilizing SO 4 = in the glass. Suitable reduced multivalents include, but are not limited to, Fe 2+ , Mn 2+ , Sn 2+ , Sb 3+ , As 3+ , V 3+ , Ti 3+ , and others familiar to those skilled in the art. In each case, it may be important to minimize the concentrations of such components so as to avoid deleterious impact on color of the glass, or in the case of As and Sb, to avoid adding such components at a high enough level so as to complication of waste management in an end-user's process.
In addition to the major oxides components of the disclosed glasses, and the minor or tramp constituents noted above, halides may be present at various levels, either as contaminants introduced through the choice of raw materials, or as deliberate components used to eliminate gaseous inclusions in the glass. As a fining agent, halides may be incorporated at a level of about 0.4 mol % or less, though it is generally desirable to use lower amounts if possible to avoid corrosion of off-gas handling equipment. In a preferred embodiment, the concentration of individual halide elements are below about 200 ppm by weight for each individual halide, or below about 800 ppm by weight for the sum of all halide elements.
In addition to these major oxide components, minor and tramp components, multivalents and halide fining agents, it may be useful to incorporate low concentrations of other colorless oxide components to achieve desired physical, optical or viscoelastic properties. Such oxides include, but are not limited to, TiO 2 , ZrO 2 , HfO 2 , Nb 2 O 5 , Ta 2 O 5 , MoO 3 , WO 3 , ZnO, In 2 O 3 , Ga 2 O 3 , Bi 2 O 3 , GeO 2 , PbO, SeO 3 , TeO 2 , Y 2 O 3 , La 2 O 3 , Gd 2 O 3 , and others known to those skilled in the art. Through an iterative process of adjusting the relative proportions of the major oxide components of the disclosed glasses, such colorless oxides can be added to a level of up to about 2 mol % without unacceptable impact to annealing point, T 35k −T liq or liquidus viscosity.
TABLE 1
Batch Material
1
2
3
4
SiO 2
72.88
71.93
71.92
70.82
Al 2 O 3
10.18
11.06
11.21
12.27
B 2 O 3
5.03
4.62
4.48
4.9
MgO
0.1
1.51
1.59
2.12
CaO
4.5
4.91
4.92
4.98
SrO
7.14
5.82
5.71
4.78
BaO
0.07
0.06
0.07
0.05
SnO 2
0.07
0.07
0.08
0.07
Fe 2 O 3
0.01
0.01
0.01
0.01
ZrO 2
0.01
0.01
0.01
0
As 2 O 3
RO/Al 2 O 3
1.16
1.11
1.10
0.97
Properties
density
2.514
2.509
2.505
2.494
strain-BBV
712.6
719.4
723.2
724.4
anneal-BBV
767.2
773.4
776.6
777.5
softening point (PPV)
1025.1
1024.3
1028
1023.8
CTE (0-300) cooling
36.6
35.9
35
33.2
Poisson's ratio
0.238
0.233
0.233
Shear modulus (Mpsi)
4.556
4.574
4.624
GPa per Mpsi
Young's modulus (Mpsi)
11.284
11.281
11.406
6.8947573
Youngs mod (GPa)
77.8
77.8
78.6
Specific modulus (Gpa/density)
31.0
31.0
31.5
Viscosity
A
−3.460
−3.515
−3.540
B
8151.30
8164.10
8018.80
To
284.90
288.90
299.80
200
200 p
1700
1693
1673
700
700 p
1578
1573
1556
2000
2 kp
1491
1487
1472
20000
20 kp
1335
1333
1322
35000
35 kp
1303
1302
1292
200000
200 kp
1215
1215
1207
Liquidus-72 h
internal
1180
1190
1190
1195
phase
Crist
Cristobalite
Cristobalite
Mullite
second phase
72 h liquidus viscosity (int)
3.5E+05
3.5E+05
2.6E+05
Batch Material
5
6
7
8
SiO 2
70.99
72.03
71.45
71.18
Al 2 O 3
12.02
12.31
12.36
12.38
B 2 O 3
4.73
1.87
1.84
1.97
MgO
2.93
3.94
5.1
4.35
CaO
4.97
5.34
5.59
6.09
SrO
4.24
4.34
3.49
3.85
BaO
0.03
0.04
0.02
0.03
SnO 2
0.07
0.09
0.11
0.1
Fe 2 O 3
0.01
0.02
0.01
0.01
ZrO 2
0
0.02
0.02
0.02
As 2 O 3
RO/Al 2 O 3
1.01
1.11
1.15
1.16
Properties
density
2.488
2.523
2.518
2.526
strain-BBV
722.8
748.9
748
748.2
anneal-BBV
777
802
799.3
799.8
softening point (PPV)
1021.1
1043.6
1034
1034.4
CTE (0-300) cooling
34
34.5
Poisson's ratio
0.234
0.237
0.221
0.229
Shear modulus (Mpsi)
4.656
4.898
4.968
4.936
GPa per Mpsi
Young's modulus (Mpsi)
11.494
12.121
12.134
12.131
6.8947573
Youngs mod (GPa)
79.2
83.6
83.7
83.6
Specific modulus (Gpa/density)
31.9
33.1
33.2
33.1
Viscosity
A
−3.339
−3.440
−3.135
−3.138
B
7567.50
7683.50
6971.90
7013.90
To
326.00
345.00
379.60
377.50
200
200 p
1668
1683
1665
1669
700
700 p
1550
1567
1546
1551
2000
2 kp
1466
1485
1463
1467
20000
20 kp
1317
1338
1316
1320
35000
35 kp
1286
1307
1287
1290
200000
200 kp
1202
1224
1205
1208
Liquidus-72 h
internal
1190
1240
1245
1240
phase
Cristobalite
Cristobalite
Cristobalite
Cristobalite
second phase
Anorthite
72 h liquidus viscosity (int)
2.6E+05
1.4E+05
8.3E+04
9.9E+04
Batch Material
9
10
11
12
SiO 2
71.24
71.67
70.47
72.42
Al 2 O 3
12.38
11.34
11.75
11.07
B 2 O 3
1.82
3.34
5.01
3.06
MgO
5.7
2.96
2.9
3.54
CaO
5.55
8.43
5.45
7.38
SrO
3.15
2.11
4.28
2.37
BaO
0.03
0.02
0.04
0.02
SnO 2
0.11
0.12
0.07
0.11
Fe 2 O 3
0.01
0.02
0.01
0.01
ZrO 2
0.02
0
0.01
0.01
As 2 O 3
RO/Al 2 O 3
1.17
1.19
1.08
1.20
Properties
density
2.514
2.476
2.49
2.471
strain-BBV
744.7
728.4
716.6
732.9
anneal-BBV
795.7
781.8
770.6
785.3
softening point (PPV)
1030
1017.6
1012.4
1025.3
CTE (0-300) cooling
35
33.9
33.9
Poisson's ratio
0.234
0.219
0.201
0.222
Shear modulus (Mpsi)
4.979
4.844
4.68
4.807
GPa per Mpsi
Young's modulus (Mpsi)
12.284
11.812
11.238
11.743
6.8947573
Youngs mod (GPa)
84.7
81.4
77.5
81.0
Specific modulus (Gpa/density)
33.7
32.9
31.1
32.8
Viscosity
A
−3.106
−2.948
−3.365
−2.844
B
6924.50
6833.70
7612.50
6833.00
To
378.70
368.60
316.30
367.60
200
200 p
1659
1670
1660
1696
700
700 p
1542
1548
1542
1569
2000
2 kp
1459
1462
1458
1480
20000
20 kp
1314
1311
1309
1324
35000
35 kp
1284
1281
1279
1292
200000
200 kp
1202
1197
1195
1207
Liquidus-72 h
internal
1250
1245
1190
1270
phase
Cristobalite
Cristobalite
Cristobalite
Cristobalite
second phase
72 h liquidus viscosity (int)
6.9E+04
7.1E+04
2.2E+05
5.3E+04
Batch Material
13
14
15
16
SiO 2
71.21
72.32
72.66
73.9
Al 2 O 3
11.52
12.82
12.65
10.86
B 2 O 3
4.77
0
0
3.14
MgO
1.76
5.65
4.88
2.17
CaO
4.99
5.57
5.75
6.68
SrO
5.62
3.5
3.91
3.1
BaO
0.06
0.03
0.03
0.03
SnO 2
0.07
0.1
0.1
0.11
Fe 2 O 3
0.01
0.01
0.01
0.01
ZrO 2
0
0.01
0
0.01
AS 2 O 3
RO/Al 2 O 3
1.08
1.15
1.15
1.10
Properties
density
2.508
2.537
2.541
2.47
strain-BBV
714.6
785.5
775.9
739.2
anneal-BBV
769.3
837.5
825.9
793.8
softening point (PPV)
1014.4
1068.5
1047.6
1040.1
CTE (0-300) cooling
34.9
35.3
34.8
Poisson's ratio
0.229
0.218
0.226
0.221
Shear modulus (Mpsi)
4.579
5.047
5.123
4.727
GPa per Mpsi
Young's modulus (Mpsi)
11.258
12.299
12.562
11.538
6.8947573
Youngs mod (GPa)
77.6
84.8
86.6
79.6
Specific modulus (Gpa/density)
30.9
33.4
34.1
32.2
Viscosity
A
−3.413
−2.508
−2.721
−3.050
B
7814.10
5771.50
6345.70
7393.00
To
304.40
484.80
435.80
345.50
200
200 p
1672
1685
1699
1727
700
700 p
1553
1563
1576
1600
2000
2 kp
1468
1478
1490
1510
20000
20 kp
1317
1332
1339
1351
35000
35 kp
1286
1303
1309
1319
200000
200 kp
1201
1224
1227
1231
Liquidus-72 h
internal
1170
1270
1260
1275
phase
Cristobalite
Cristobalite
Cristobalite
Cristobalite
second phase
72 h liquidus viscosity (int)
4.1E+05
7.0E+04
9.5E+04
8.0E+04
Batch Material
17
18
19
20
SiO 2
68.11
71.23
72.2
70.74
Al 2 O 3
12.72
12.41
12.49
13
B 2 O 3
4.5
2.54
0.95
2.48
MgO
4.38
3.62
4.5
3.35
CaO
6.44
5.23
5.58
4.58
SrO
3.7
1.42
3.16
1.43
BaO
0.02
3.43
1.01
4.28
SnO 2
0.09
0.1
0.09
0.1
Fe 2 O 3
0.01
0.01
0.01
0.01
ZrO 2
0.03
0.01
0.01
0.02
As 2 O 3
RO/Al 2 O 3
1.14
1.10
1.14
1.05
Properties
density
2.517
2.57
2.548
2.605
strain-BBV
720.7
743.3
759.8
743.1
anneal-BBV
771.6
798.2
810.9
795.9
softening point (PPV)
996.1
1043.7
1050.1
1043.1
CTE (0-300) cooling
34.3
34.9
36.7
36.4
Poisson's ratio
0.234
0.234
0.238
0.219
Shear modulus (Mpsi)
4.805
4.757
4.968
4.802
GPa per Mpsi
Young's modulus (Mpsi)
11.86
11.746
12.3
11.708
6.8947573
Youngs mod (GPa)
81.8
81.0
84.8
80.7
Specific modulus (Gpa/density)
32.5
31.5
33.3
31.0
Viscosity
A
−2.879
−3.526
−3.374
−3.612
B
6338.60
7900.35
7576.99
8055.85
To
389.30
330.76
356.08
318.86
200
200 p
1613
1687
1691
1681
700
700 p
1497
1571
1574
1566
2000
2 kp
1415
1488
1491
1484
20000
20 kp
1272
1340
1343
1337
35000
35 kp
1243
1310
1313
1307
200000
200 kp
1164
1226
1230
1223
Liquidus-72 h
internal
1185
1195
1260
1190
phase
anorthite
Cristobalite
Cristobalite
mullite
second phase
72 h liquidus viscosity (int)
1.2E+05
4.1E+05
1.0E+05
4.3E+05
Batch Material
21
22
23
24
SiO 2
72.16
72.29
70.62
71.68
Al 2 O 3
11.86
11.6
13.09
12.38
B 2 O 3
0
0
1.5
0.76
MgO
5.53
4.83
4.84
4.99
CaO
5.4
5.95
5.75
5.29
SrO
1.59
0.99
1.52
1.47
BaO
3.31
4.18
2.58
3.36
SnO 2
0.11
0.11
0.08
0.08
Fe 2 O 3
0.02
0.02
0.01
ZrO 2
0.02
0.02
0.02
As 2 O 3
RO/Al 2 O 3
1.33
1.38
1.12
Properties
density
2.616
2.604
2.575
strain-BBV
764
762
752
anneal-BBV
816
817
805
softening point (PPV)
1050.7
1057.8
1041.3
CTE (0-300) cooling
36.7
34.9
34.6
Poisson's ratio
Shear modulus (Mpsi)
GPa per Mpsi
Young's modulus (Mpsi)
6.8947573
Youngs mod (GPa)
84.8
83.6
84.1
Specific modulus (Gpa/density)
Viscosity
A
−3.02159
−2.98998
−3.10916
B
6981.809
6990.12
6956.355
To
386.1695
387.4732
383.4808
200
200 p
1698
1709
1669
700
700 p
1576
1585
1552
2000
2 kp
20000
20 kp
35000
35 kp
1309
1315
1292
200000
200 kp
Liquidus-72 h
internal
1210
1210
1190
phase
second phase
72 h liquidus viscosity (int)
What is disclosed is a glass substrate with exceptional total pitch variability (TPV), as measured by three metrics: (1) compaction in the High Temperature Test Cycle (HTTC) less than 40 ppm, (2) compaction in the Low Temperature Test Cycle (LTTC) less than 5.5 ppm, and (3) stress relaxation rate consistent with less than 50% relaxed in the Stress Relaxation Test Cycle (SRTC). By satisfying all three criteria, the substrate is assured of being acceptable for the highest resolution TFT cycles. A brief description of these test cycles follows:
High Temperature Test Cycle (HTTC)
The samples were heat treated in a box furnace according to the thermal profile shown in FIG. 1 . First, the furnace was preheated to slightly above 590° C. The stack of five samples was then plunged into the furnace through a small slit in the front of the furnace. After thirty minutes the samples are quenched out of the furnace into ambient air. The total time the samples reside at the peak temperature 590° C. is about 18 minutes. For purposes of this disclosure, this test criteria shall be defined as high temperature test cycle or HTTC. In one embodiment, the HTTC compaction is less than or equal to 40 ppm. In another embodiment, the HTTC compaction is less than or equal to 38 ppm. In another embodiment, the HTTC compaction is less than or equal to 36 ppm. In another embodiment, the HTTC compaction is less than or equal to 30 ppm. In another embodiment, the HTTC compaction is less than or equal to 25 ppm. In another embodiment, the HTTC compaction is less than or equal to 20 ppm.
Low Temperature Test Cycle (LTTC)
The thermal compaction magnitude resulting from typical TFT array or CF substrate thermal cycles is insufficient to make reliable quality assurance measurements. A 450° C./1 hour thermal cycle is used to achieve a greater compaction signal, enabling the identification of real changes in performance The furnace is held at just above 450° C. prior to plunging in a stack of five samples (four experimental and one control). The furnace requires approximately 7 minutes recovery time to the target hold temperature. Samples are held at 450° C. for one hour and then plunged out to room temperature. An example thermal trace is shown in FIG. 2 . For purposes of this disclosure, this test criteria shall be defined as low temperature test cycle or LTTC. In one embodiment, the LTTC compaction is less than or equal to 5.5 ppm. In another embodiment, the LTTC compaction is less than or equal to 5 ppm. In another embodiment, the LTTC compaction is less than or equal to 4.6 ppm.
Stress Relaxation Test Cycle (SRTC)
The glass plates were cut into beams of 10.00 mm width. The thickness of the glass was maintained at its as-formed thickness (between 0.5 mm and 0.7 mm). The stress relaxation experiment started by loading the glass sample onto two rigid supports placed inside a resistively heated electrical furnace, placing an S-type thermocouple in close proximity to the center of the beam, and adjusting the push rod position. The span length of the two rigid supports was 88.90 mm. The lower end of the push rod was about 5 mm above the surface of the glass at room temperature. The temperature of the furnace was rapidly brought up to the final experimental temperature of 650° C. and idled there for about 5 minutes in order to achieve thermal equilibrium of all parts placed inside the furnace. The experiment continued by lowering the push rod at a rate of 2.54 mm/min and monitoring the signal of the load cell (LC). This was done in order to find a contact of the push rod with the glass beam. Once the LC signal reached 0.1 lb, it triggered an acceleration of the loading rate to 10.16 mm/min. The loading was stopped when the central deflection of the beam reached the final target value (e.g., 2.54 mm), and the program switched from a stress controlled mode to a strain controlled mode. The strain was held constant during the rest of the experiment whereas the stress was variable. The total time from the first contact of the push rod with the glass to the point where the maximum strain of 2.54 mm was achieved was about 12 s. The experiment ended after several hours of data had been collected. It is worth noting that no significant overshoot in temperature was observed at the beginning of the isothermal hold due to careful optimization of the proportional-integral-derivative parameters of the furnace controller.
All the stress relaxation experiments were conducted under isothermal conditions, where the temperature was constantly monitored by an S-type thermocouple placed close to the center of the flat beam of glass. Temperature fluctuations during the experiments did not exceed 0.5° C. Separate experiments regarding the temperature homogeneity across the length of the glassy beam were conducted prior the actual stress relaxation experiments. Temperature homogeneity should not exceed 2° C. at any given experimental time and condition. In principle the stress experiment mimics a classic three point bending experiment where the load is applied on a well-defined center of the beam, deflecting it for 2.54 mm from the original zero line, and then holding it at this constant strain. The central push rod transfers the load (stress) when it comes into the contact with the glassy beam. The end of the central push rod has a knife edge shape, and the width of the wedge is slightly greater than that of the glassy beam. The top-line of the wedge-shaped push rod is perfectly parallel with the surface of the glass beam. Such a configuration assures a homogeneous distribution of the stress across the width of the beam. The push rod is coupled with a linearly variable displacement transducer which controls the displacement. The instrument was also equipped with a well calibrated LC, which maintained the central load applied to the glassy beam during the ongoing relaxation. Due to the nonlinearity of the relaxation process—where the relaxation is initially fast and then gradually slows down—for data recording purposes we split each relaxation experiment into three segments. The first one collected data at 0.5 s intervals; the second segment collected data every 1.0 s, and the third every 10.0 s. Regarding the possibility of stress relaxation during the loading period (i.e., the first 12 s of the experiment) all the loading curves for the glass compositions under study were plotted and in each case the loading curve exhibited a linear stress/strain relationship indicating a primarily elastic response during loading. Hence, the zero time point of the stress relaxation measurements was taken as the time at which the experiment switched from a stress controlled mode to a strain controlled mode, as described above. Percent stress relaxed R during the cycle is defined by
R = 100 ( 1 - S 60 S 0 )
where S 60 is the stress imposed by the controlled push rod at 60 minutes (the end of the SRTC) and S 0 is the stress imposed at 0 minutes (the start of the SRTC). For purposes of this disclosure, the above test criteria shall be defined as stress relaxation test cycle (SRTC). In one embodiment, the percent stress relaxed in the SRTC is equal to or less than 50%. In another embodiment, the percent stress relaxed in the SRTC is equal to or less than 45%. In another embodiment, the percent stress relaxed in the SRTC is equal to or less than 40%. In another embodiment, the percent stress relaxed in the SRTC is equal to or less than 35%.
The Test Cycles and TPV
These three measurements are capable of representing the total pitch variability performance of a glass substrate since they capture the primary drivers for total pitch variability under a thermal process: structural relaxation (or compaction) at high and low temperatures and stress relaxation. Historically, the contribution of compaction to total pitch variability has been dominated by high temperature behaviors since registry marks were placed later in customers' TFT processes, making many of the low temperature steps early in these processes irrelevant. This high temperature compaction is described by the HTTC compaction and is reduced by either reducing the cooling rate of the glass ribbon during manufacture, annealing the glass sheet offline, and/or increasing the viscosity of the glass (as captured by T(ann)). FIG. 3 shows a general reduction of compaction as the T(ann) is increased, with the main exceptions being glasses made with significantly different thermal histories (such as via the float process instead of the fusion draw process). This illustrates how glass manufacturers have handled total pitch in the past: they have either slowed cooling rates and/or increased annealing point to suppress compaction in the temperature regime that mattered (i.e. high temperatures).
Recent changes in the TFT market have now forced panel makers to place their registry marks at the beginning of their process, making many previously irrelevant low temperature steps critical to the variability in measured total pitch. As a general rule, compaction at low temperatures (captured by the LTTC in FIG. 4 ) follows a similar trend as in the HTTC but, at high T(ann) (e.g. greater than 750° C.), the compaction seems to decouple from the T(ann) and become a flat line at roughly 6 ppm. This shows that one of the traditional paths to reducing compaction, increasing T(ann), is no longer a viable solitary solution. The high annealing point glasses that have reduced LTTC compaction in FIG. 4 are the result of the management of a relaxation mechanism in the glass that is operating at a considerably faster rate than would be predicted based on traditional understanding of glass relaxation kinetics. This mechanism has been linked to highly mobile tramp constituents in the glass, such as alkali and water and, additionally, a lower (MgO+CaO+SrO+BaO)/Al 2 O 3 has been correlated with lower LTTC compaction. Coupling this newfound understanding of a compositional basis for control of this fast relaxation mechanism with optimized cooling curve control has resulted in lower LTTC compaction in certain compositions independent of T(ann) (as evidenced by the high LTTC compaction (5.8 and 6.5 ppm at 0.7 and 0.5 mm, respectively) of Glass 8 (see Table 2) despite a high T(ann)=808° C.). It is quite possible that a glass with excellent HTTC compaction may have unacceptable LTTC compaction due to this decoupling and the simultaneous management of both is important in today's TFT processes.
In both compaction cycles, glasses cooled with exceptionally slow cooling rates (such as those experienced during the float process) have very good compaction performance, as shown by several of the Glass 2 samples from Table 2. These glasses perform well in old TFT processes but are struggle in the new cycles needed for the highest resolution displays made on large gen sizes. This is due to the other aspect of TPV: stress relaxation, which scales directly with low temperature viscosity. FIG. 5 shows the percent of an induced stress that relaxes in the SRTC, and the virtually linear dependence on T(ann) is clearly observed. This helps explain why lower annealing point glasses with slow quench rates that previously worked for panel makers are no longer viable. In FIG. 5 , glasses relaxing less than 50% of the stress satisfy the SRTC criteria of the disclosure.
It has been discovered that the management of all three aspects of TPV is advantageous and considerable interactions with many customers have helped us to define the “success criteria” for all three test cycles (indicated by the red lines on FIGS. 3 , 4 , and 5 ). FIG. 6 a plots the HTTC compaction against the LTTC compaction with glasses satisfying the success criteria falling in Region 1 as identified. Glasses satisfying the stress relaxation requirements are indicated by diamonds while the glasses failing the stress relaxation requirement are indicated by squares. The glasses disclosed in this invention are, therefore, the diamonds that fall within Region 1 (more easily seen in FIG. 6 b ).
Previously disclosed substrates have attempted to accomplish low TPV through higher annealing points or process control (e.g. slow cooling during manufacture). As evidenced by FIG. 6 , these efforts have always resulted in a substrate failing one of these three criteria, thereby rendering the substrate sub-optimal for certain TFT cycles. In addition to these important attributes for TPV, a glass of this disclosure could also be consistent with other attributes advantageous for the manufacture of TFTs (such as low density, high UV transmission, etc.).
TABLE 2
LTTC
HTTC
Compaction
Compaction
SRTC
Glass ID
T(ann)
(ppm)
(ppm)
% Relaxed
Glass 1 0.5 mm
798
5.1
23.6
33.3
Glass 2 0.5 mm
721
5.4
34.2
72.3
Glass 2 0.5 mm
721
4.7
36.5
72.3
Glass 2 0.5 mm
721
3.9
37.6
72.3
Glass 2 0.5 mm
721
5.7
59.3
72.3
Glass 3 0.5 mm
795
6.7
32.4
33.3
Glass 3 0.7 mm
795
5.6
26.3
33.3
Glass 4 0.5 mm
768
7.1
43.7
56.2
Glass 4 0.7 mm
768
7.2
46.3
56.2
Glass 4 0.63 mm
768
7.6
48.2
56.2
Glass 4 1.1 mm
768
5.2
29.6
56.2
Glass 4 0.7 mm
768
6.1
37.5
56.2
Glass 4 0.5 mm
768
7.0
44.9
56.2
Glass 4 0.5 mm
768
7.1
47.7
56.2
Glass 5 0.63 mm
743
8.2
69.6
69
Glass 6 0.63 mm
775
4.6
35.5
46.2
Glass 6 0.7 mm
775
4.8
32.4
46.2
Glass 7 0.7 mm
798
5.5
26.4
33.3
Glass 8 0.5 mm
808
6.5
29.7
31.7
Glass 8 0.7 mm
808
5.8
26.2
31.7
Glass 9 0.7 mm
785
5.7
32.5
Glass 10 0.5 mm
722
12.0
116.8
Glass 10 0.5 mm
722
17.7
147.9
Glass 11 0.63 mm
722
18.3
152.0
Glass 12 0.5 mm
774
8.4
49.6
Glass 13 0.5 mm
786
6.9
41.2
Glass 14 0.5 mm
791
7.4
36.3
Glass 15 0.5 mm
710
6.4
62.6
88.75
Glass 16 0.5 mm
710
8.8
87.8
88.75
Glass 17 0.5 mm
762
4.4
45.0
55.6
Table 2 is a sampling of glasses both experimental and commercially available that were tested according to the HTTC, LTTC and SRTC criteria described herein. Glasses 1, 6 and 7 are experimental glasses that were tested and met the criteria as described in one embodiment (HTTC less than or equal to 40 ppm, LTTC less than or equal to 5.5 ppm and SRTC less than 50%). Glasses 2, 4, 9, 10, 11, 15, 16 and 17 represent present or past commercial glasses that were tested and failed the testing criteria as demonstrated by the results. Glasses 5, 8, 12, 13 and 14 are experimental glasses that failed the testing criteria.
Various modifications and variations can be made to the materials, methods, and articles described herein. Other aspects of the materials, methods, and articles described herein will be apparent from consideration of the specification and practice of the materials, methods, and articles disclosed herein. It is intended that the specification and examples be considered as exemplary.
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Described herein are alkali-free, boroalumino silicate glasses exhibiting desirable physical and chemical properties for use as substrates in flat panel display devices, such as, active matrix liquid crystal displays (AMLCDs) and active matrix organic light emitting diode displays (AMOLEDs). In accordance with certain of its aspects, the glasses possess excellent compaction and stress relaxation properties.
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.Iadd.CROSS-REFERENCE TO RELATED APPLICATION .Iaddend.
.Iadd.This is a reissue application of patent 4,125,421 which matured into patent from application Serial No. 817,086 filed July 18, 1977. .Iaddend.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the art of label printing and applying apparatus.
2. Brief Description of the Prior Art
U.S. Pat. No. 1,665,467 to David B. Miller dated Apr. 10, 1928 discloses a stamping device in which a pivotally mounted hammer is tripped into printing cooperation with a marking stamp.
U.S. Pat. No. 3,408,931 to Charles C. Austin dated Nov. 5, 1968 discloses a hand-held label printer in which a print head is mounted for straight line reciprocating movement. This patent discloses cocking means responsive to an actuator for moving the print head from printing to a retracted position during the cycle, a detent for holding the print head in the retracted position during a subsequent part of the cycle, and trip means responsive to the actuator at or near the end of the cycle to disengage the detent, thereby permitting a spring to snap the print head into printing position.
Published German patent application No. P 23 45 249.5-27 (2530346) and its corresponding U.S. Pat. No. 4,072,105 of Meto International GmbH disclose a hand-held labeler having an actuating lever and a spring-urged print head lever. The spring may be cocked by swinging the actuating lever up to the point of reaching a spring force which is greater than the maximum of resistance opposed to the movement of the printing mechanism toward the platen. When this occurs, the print head will be snapped against the platen with constant force independent of the force or speed of movement of the actuator level.
U.S. Pat. No. 3,911,817 to Werner Becker et al dated Oct. 14, 1975 discloses a device for printing and dispensing labels in which a printing mechanism and a label strip advancing mechanism are actuated by movement of a secondary lever and the secondary lever is moved by a primary lever only after actuation of the primary lever to exceed a predetermined biasing force tending to maintain the secondary lever stationary.
U.S. Pat. No. 3,957,562 to Paul H. Hamisch, Jr. dated May 18, 1976 discloses a hand-held labeler having a frame with a handle, an actuator disposed at the handle, a gear segment carried by the actuator, a gear having a gear segment meshing with the actuator gear segment and another gear segment meshing with a print head gear, movement of the actuator effects direct movement of the print head through the gears without any lost motion. The labeler also includes a platen with which the print head is cooperable, a delaminator for delaminating labels, an applicator for applying printed labels and a pawl and ratchet mechanism effective when the actuator is released to advance the web. Other prior art disclosing hand-held labelers, in which the printing mechanism is triggered to control impression, are German Offenlegungsschrift No. 2,656,862 and German Offenlegungsschrift No. 2,729,097.
SUMMARY OF THE INVENTION
This invention relates to a hand-held labeler in which the print head is connected to the actuator through gearing and a lost-motion connection. When the actuator is moved through a predetermined distance from an initial position to an another position, there is lost motion between the gears until the actuator has moved through a predetermined increment through the lost-motion connection. The other gear is held in the initial position by a pawl or latch until the pawl is tripped. A spring is used to urge the print head into printing cooperation with the platen and another spring is used to return the print head, the gears and the actuator to their initial positions and to advance the label carrier web as the actuator moves between the actuated position and the initial position following release of the actuator.
The labeler also includes an arrangement to prevent the print head from becoming dislocated from the frame when the labeler is impacted, such as when the labeler is dropped on the floor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of an embodiment of label printing and applying apparatus;
FIG. 2 is a partly broken away side elevational view of the apparatus with a removable housing section removed for clarity;
FIG. 3 is a fragmentary elevational view of the other side of the apparatus shown in FIG. 2;
FIG. 4 is a sectional view taken along line 4--4 of FIG. 3;
FIG. 5 is an exploded perspective view of the feed wheel together with a quick-change clutching and declutching mechanism, with the axis curved for clarity;
FIG. 6 is an end elevational view showing many of the components in FIG. 5 in a position of partial assembly;
FIG. 7 is an end elevational view of the quick-change mechanism showing drive pawls moving toward their retracted positions;
FIG. 8 is a fragmentary elevational view showing toothed clutch members of the mechanism in one extreme selected position;
FIG. 9 is a fragmentary sectional view showing the clutch members declutched to enable rotation of the ratchet wheel relative to the feed wheel;
FIG. 10 is a fragmentary elevational view partly in section showing the clutch members in clutched position;
FIG. 11 is a fragmentary view showing one gear segment moved to a position in which the latch is about to be tripped;
FIG. 12 is a exploded perspective view of the gear assembly;
FIG. 13 is a fragmentary view similar to FIG. 11 but showing the latch as having been tripped;
FIG. 14 is a sectional view taken along line 14--14 of FIG. 11;
FIG. 15 is a fragmentary view similar to FIG. 11 but showing an alternative embodiment; and
FIG. 16 is a sectional view taken along line 16--16 of FIG. 15.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, there is shown a label printing and applying apparatus generally indicated at 150. The apparatus 150 has a frame generally indicated at 151 which is shown to comprise a frame or housing having housing sections 152, 153 and 154 and a subframe comprising a single, rigid, metal frame plate 155. The housing is essentially closed. The frame 151 has a handle generally indicated at 159 comprised in part of a handle portion 160 and in part of the frame section 154. The housing section 154 is secured to the housing section 152 by screws 161 received in respective threaded holes 162. The frame section 153 is positioned in front of a lip 163 of the section 154 and projections 164 on the section 153 extend behind a wall 165. The section 153 is connected to the section 152 by snapfit connections including generally snap-shaped flexible resilient members 166 engageable in respective undercut recesses 167 in the section 152. The section 153 is also provided with locating studs 168 received in respective recesses 169 of the section 152.
The frame plate 155 mounts a print head 170, a feed wheel 171, a gear assembly 172, an applicator 173 shown to be in the form of a roll, a platen 174, a delaminator 175, a mounting pin 176 and a plurality of rollers 177, mounting posts 178, 179, 180 and 181, and a support 236.
The frame plate 155 is provided with two spaced-apart precisely located rectangular holes in which respective square mating locating pins or studs 183 are received. There are three identical hold-down connections which secure the frame plate 155 to the housing section 152.
The frame plate 155 has a pair of elongated cutouts or open-ended slots 188 and a pair of oppositely facing elongated cutouts or open ended slots 189. The slots 188 and 189 communicate with larger respective cutouts 190 and 191. Oppositely facing ball tracks 192 and 193 are received in respective cutouts 190 and 191. The print head 170 comprises a print head frame 194 having a pair of oppositely facing ball tracks 195 and 196. A ball bearing strip 197 is received in mating ball bearing tracks 192 and 195 and a ball bearing strip 198 is received in mating ball bearing tracks 193 and 196. The ball tracks 192 and 193 are shown to be generally channel-shaped in construction. When the ball tracks 192 and 193 are in the position as shown in FIGS. 3 and 4, the ball tracks 192 and 193 are received by the frame plate 155. Threaded fasteners 199 extend through the cutouts 188 and are threadably received in holes 199' in the ball track 192. Similarly, threaded fasteners 200 extend through cutouts 189 and are threadably received in holes 200' in the ball track 193. The print head 170 is capable of printing two lines of data in that the print head 170 has two lines of printing bands 201.
The apparatus 150 is shown to utilize a composite web 203. The composite web 203 of label material 204 is releasably adhered to supporting a backing material 205. The label material 204 is cut transversely by butt cuts or slits 206 extending all the way across the web 204 of label material, thereby separating the label material 204 into a series of end-to-end labels 207. The composite web 203 can be wound onto a circular cylindrical core 208 composed of paperboard or other suitable material. The feed wheel 171 has a plurality of pairs of transversely spaced-apart teeth 171' which engage the supporting material web 205. The composite web roll R is mounted on a reel generally indicated at 209. The reel 209 is comprised of a generally flat disc 210 having a central hole 211. Disc 210 has a plurality of equally spaced-apart pins 212 disposed at equal distances from the central hole 211. The reel 209 also includes a hub generally indicated at 213. The hub 213 has a central tubular hub portion 214 joined to an end wall. The pins 212 are received in mating holes 212' in the end wall, thereby keying the disc 210 and the hub 213 for rotation together as a unit. Spaced outwardly from the hub portion 214 and joined integrally to the end wall are a plurality of flexible, resilient, cantilever mounted fingers 216 having projections 217. A retainer 221 received by the marginal end of the shaft 181 prevents the reel 209 from shifting off the post or shaft 181 and prevents the hub 213 from separating from the disc 210 so that the pins 212 do not loose engagement with the holes 212'.
An actuator generally indicated at 222 is shown to take the form of a pivotally operated lever mounted by support structure including a pivot pin 223 received in an eccentric 224 in the form of a sleeve. The actuator 222 is urged in a counterclockwise direction (FIGS. 1 and 2) by a spring assembly 225 which includes a compression spring 226.
The actuator 222 carries a first member, namely, a gear or gear section 227 having an opening 228 provided by a missing tooth. The gear section 227 is in meshing engagement with a second member, namely, gear section or segment 229 of the gear assembly 172. The gear assembly 172 also has a gear section or segment 231 in meshing engagment with the gear section or rack 232 formed integrally with the print head frame 194. Assuming the handle 159 is being held in the user's hand, the user's fingers can operate the actuator 222 to pivot the actuator 222 clockwise (FIGS. 1 and 2) against the force of the spring 226 in the spring device 225, thereby causing the gear segment 229 to rotate counterclockwise. Sections 152 and 154 have stops 151'.
A drive shaft 235 is molded integrally with the gear segment 229. The support 236, in the form of a tube or tubular bearing, is suitably secured in a hole 237' (FIG. 9) in the frame plate 155.
A brake 270 includes a brake member 283 which has a brake shoe 284 composed of a flexible resilient material. During use of the apparatus, the brake member 283 is stationary. However, during loading of the composite web 203, the brake member 283 can be moved manually to its ineffective position. The brake member 283 is integrally joined by a hub 285 to a slotted arm 286. The hub 285 is pivotally mounted on the post 178. The arm 286 has an elongated slot 287. A slide 288 has an elongated slot 289 which receives the post 178 and a pin 290 secured to the arm 286 to provide a pin-and-slot connection. The slide 288 has a finger-engageable projection 288' by which the slide 288 can be moved. As the slide 288 moves in one direction, the pin 290 cooperates with the slot 287 to pivot the arm 286 and the brake member 283 counterclockwise. A shaft 291 extends through a bore 292 in the slide 288.
The shaft 291 mounts a roll 293 comprised of a roll member 294 on one side of the slide 288 and a roll member 295 on the other side of the slide 288. The shaft 291 also passes through an elongated arcuate slot 296 of an arm 297 which is pivotally connected to a pin 298 of the gear segment 229. A washer 299 (FIG. 1) is disposed on the shaft 291 between the roll member 294 and the arm 297 and a retractable guide 300 is disposed on the shaft 291 between the roll member 295 and a retainer 301 secured to the marginal end of the shaft 291. Guide section 312 has an integral pin 300' received in an elongated slot 300" in the guide 300. The shaft 291 is secured to an arm 302 pivotally mounted on a stud 303 carried by the frame plate 155.
From the place where the composite web 203 is paid out of the roll, it passes over and in contact with a resilient device 310 in the form of a curved leaf spring. The resilient device 310 deflects when the feed wheel 171 is advancing the composite web 203 and after the brake 270 is applied the device 310 gradually returns as additional web 203 is caused to be paid out of the supply roll R. Track structure generally indicated at 311 includes guide track sections 312, 313 and 314. The track section 312 has a forked end 315 which is received by marginal end 316 of an extension 318 of the platen 174. The track section 312 has a short tubular portion 319 which is received by the post 179. Accordingly, the track section 312 is securely held in position relative to the frame plate 155 by the marginal end 316 and by the post 179. After passing in contact with the resilient device 310, the composite web 203 enters a first zone Z1 above the track structure 312 and below the print head 170. The print head 170 carries a roll 320 comprised of a plurality of for example, three rollers 321 rotatably mounted on a shaft 322 mounted on the print head 170. The rollers 321 deflect the composite web 203 into contact with the track section 312 as the print head 170 moves. From the zone Z1 the composite web 203 passes partly around a roll generally indicated at 323 which is comprised of three rollers 177. After the composite web 203 passes around the roll 323, a label 207 of the composite web 203 is disposed between the platen 174 and the print head 170. FIG. 2 shows one of the labels 207 as being almost entirely delaminated from the supporting material web 205 and ready to be applied by applicator 173. The applicator 173 is shown to comprise a roll rotatably mounted on a post 325 secured to the frame plate 155, although other types of applicators can be used instead if desired. A removable retainer 326 maintains the applicator 173 on the post 325. In the loading position shown in FIG. 2, the composite web 203 passes partly around an end of the slide 288 and partly around the roll 293 and from there partly around the feed wheel 171. The shaft 178 carries a roller 327 (FIG. 1) between the hub 285 and the frame plate 155 and a roller 328 disposed between the slide 288 and a retainer 329.
The track section 313 cooperates with the track section 314 to provide a discharge chute at a zone Z2 through which the supporting material web 205 exits. The track section 313 has a pair of spaced-apart tubular portions 330 and 331 received respectively by posts 179 and 180. The track section 313 has an integrally formed curved retaining bracket 332 which passes partly around a flange 333 of a post 334. Thus, the track section 313 is secured to the frame plate 155 and to the housing section 152. The track section 313 includes a channel-shaped portion 335 to which the connector 332 is joined. The track section 314 has an offset flange 336 which fits into the channel-shaped portion 335 to interlock the track section 314 with the track section 313. The track section 314 also has a curved retaining bracket 337 which extends partly around the flange 333 and has a pair of spaced-apart offset flanges 338 and 339 which fits against the outside of the channel-shaped portion 335. A tubular portion 330' secures one end of the track section 314 to the frame plate 155 and the flanges 336, 338 and 339 interlock the track sections 313 and 314. The track structure 311 also includes a stripper 340 which engages the smooth annular outer surface 171a of the feed wheel 171. The stripper 340 is provided with pair of offset flanges 341 and 342 which fits respectively into grooves 343 and 344 in the track section 313. The post 179 is longer than the combined lengths of the tubular portions 319, 330 and 330' and thus a projection 345 formed integrally with the stripper 340 can fit snugly into the end of the tubular portion 331.
As best shown in FIG. 1, the resilient device 310 has a connector 348 received in an undercut recess 353 in the track section 213. The housing is shown to have an opening 354 (FIG. 2) having relatively sharp external edges 355 and 356 which can serve as cutting edges for removing the excess web 205.
With reference to FIG. 3, ink roll 401 is shown to be rotatably mounted on a post 401' secured to an arm 402. The arm 402 is pivotally mounted on a post 403 secured to the frame plate 155. A tension spring 404 is connected at one end to an upstanding tab 405 on the arm 402 and its other end to a post 406 mounted on the frame plate 155. The arm 402 and the ink roll 401 are shown in one extreme position by solid lines in which the print head 170 is in its retracted position and by phantom lines in which the print head 170 is in its extended or printing position. The shaft 401' extends through an arcuate slot 407 in the frame plate 155.
With reference initialy to FIG. 5, there is shown the feed wheel 171 which is secured against relative rotation to the rolling-contact type one-way clutch 243. The feed wheel 171 has a hub portion 500. The hub portion 500 has an annular flange 501 against which one end of the clutch 243 abuts. The feed wheel 171 is provided with a plurality of equally spaced-apart toothed segments 502 arranged in an annular row and disposed in a common plane. The toothed segments 502 have a plurality of teeth formed by ridges 503 and intervening grooves 504. A drive wheel is shown to comprise a ratchet wheel 505 having a plurality of teeth 506 disposed at equally spaced-apart intervals. The ratchet wheel 505 has a hub portion 505', both axially slidably and rotatably mounted on outer circular cylindrical surface 246 of the support 236. Hence the feed wheel 171 and the ratchet wheel 505 are coaxially mounted for relative axial shifting and rotational movement. The ratchet wheel 505 has a plurality of equally spaced-apart toothed segments 507 arranged in an annular row and disposed in a common plane. The toothed segments 507 have ridges 508 and intervening grooves 509. The annular extent or width of the segments 507 is slightly less than the annular extent or width of the segments 502. The number of segments 507 is equal to the number of segments 502, and the pitch of the ridges 503 and grooves 504 is equal to the pitch of the ridges 508 and grooves 509. Accordingly, the ratchet wheel 505 and the feed wheel 171 can be readily assembled as well be described below in greater detail.
A helical, compression, clutch spring 510 is shown to be disposed about hub portion 505' of the ratchet wheel 505 and to be received in a recess 511. One end of the clutch spring 510 abuts against an annular flange 512 of the ratchet wheel 505 and the other end of the clutch spring 510 abuts against one end of the clutch 243. The spring 510 normally urges the clutch member 507 into clutching engagement with the clutch member 502 as shown in FIG. 9. However, to effect change of position of the ratchet wheel 505 relative to the feed wheel 171, the user uses his fingers to push on the knurled bead 513 on the outer surfaces of the ratchet wheel 505 and pushes the ratchet wheel from the position shown in FIG. 9 to the position shown in FIG. 8, thereby compressing the clutch spring 510. In this axially shifted position of the ratchet wheel 505 relative to the feed wheel 171, the user can rotate the ratchet wheel 505 relative to the feed wheel 171 to a new position of adjustment, and when in this position the user simply stops pushing on the bead 513 and the spring 510 will thereupon urge the ratchet wheel 505 axially until the toothed members 507 clutch with the toothed member 502 in the new selected position. A change of position of the feed wheel 171 and the ratchet wheel 505 relative to each other will change the position to which the composite web 203 is advanced relative to the platen 174 and relative to the delaminator 175.
In order to prevent the ratchet wheel 505 and the feed wheel 171 from being moved to relative positions in which respective toothed members 502 and 507 are out of alignment and are disassembled from each other by the force exerted by the clutch spring 510, thereiis provided a stop device 514 having a pair of stops 515 and 515'. The stops 515 and 515' extend in an axial direction and are secured to a hollow body 516 received by the feed wheel 171. The stops 515 and 515' extend through slots or holes 171h in webs 171w which join the hub portion 518 and rim 238, thereby preventing rotation of the stop device 514 relative to the feed wheel 171. An annular ring 517 secured to the body 516 is received about a hub portion 518 of the feed wheel 171. The ring 517 has a plurality of flexible resilient fingers 519 each of which has a respective projection 520. The spring fingers 519 prevent movement of the stop member 514 toward the plate 155 to a position in which stops 515 and 515' would be out of the path of the toothed member 507. As best shown in FIG. 8, in which the clutch members 507 are in one extreme position relative to the clutch members 502, the stop 515' prevents further clockwise movement of the clutch members 507 relative to the clutch members 504. When a side surface of the clutch member 507 which is disposed between the stops 515 and 515' contacts the stop 515 it will prevent further counterclockwise movement of the rachet wheel 505 relative to the feed wheel 171, thereby preventing axial misalignment of clutch members 507 and 502.
The clutch members 502 extend radially inwardly from rim 238 of the feed wheel 171 and the respective ridges 503 and grooves 504 are inclined in one direction relative to the axis of the feed wheel 171 as best shown in FIGS. 8 and 9. The clutch members 507 are shown to be secured to a web 521 joined to the annular wall 512, and the clutch members 507 extend in a radial outward direction. The ridges 508 and grooves 509 are inclined relative to the axis of the feed wheel 171 but in the same direction as the ridges 503 and the grooves 504. When the ratchet wheel 505 is in the position with respect to the feed wheel 171 shown in FIG. 10, the clutch members 502 and 507 are clutched together by the action of the clutch spring 510.
Pawl structure 522 is shown to include a hub 523. The hub 523 has a non-circular hole 524 with a flat 525. The hub 523 is received by the shaft 235 which has a flat 262 (FIG. 12) which faces the flat 525. The shaft 235 is received in the elongated hole or bore 261. A grip ring 526 is received by the drive shaft 235 and retains the pawl structure 522 in position. It is noted that end portion 527 of the ratchet wheel 505 abuts annular face 528 (FIG. 8) of the pawl structure 522 when the clutch members 502 and 507 are in meshing engagement as shown in FIG. 10. The pawl structure 522 includes a pair of arms 529 and 530 secured to the hub 523. The arms 529 and 530 carry respective drive pawls 531 and 532. The drive ends 533 and 534 simultaneously engage respective teeth 506 as best shown in FIG. 5. In driving the feed wheel 171, the pawl structure 522 is initially in the position shown in FIG. 6. Thereafter, as the drive shaft 235 is rotated, the pawl structure 522 moves through a transitory position shown in FIG. 7 until drive ends 533 and 534 moves into engagement with the next successive pair of teeth 506. Upon rotation of the drive shaft 235 in the opposite direction, the drive pawls 531 and 532 cause the feed wheel 171 to pull the supporting material web 205, thereby advancing the composite web 203 through a distance equal to one label length. The change of position to which the composite web is advanced can be changed as described above. When the feed wheel 171 has advanced the composite web 203 following the printing operation, only the trailing marginal edge of the leading label 207 is adhered to the web 205. The quick-change clutching and declutching mechanism enables the user to vary the width of the trailing marginal edge of the label which is adhered to the web 205 and also changes the registration of the leading label 207 relative to the platen 174 and the print head 170.
With reference to FIG. 12, the gear segment 229 is shown to have a bearing 550 which is coaxial with the shaft 235. The gear segment 231 has an annular hole 551 by which the gear segment 231 is rotatable on the bearing 550. There is a post 552 on the gear segment 229 and a post 553 on the gear segment 231. A tension spring 554 is connected at its one end portion to the post 252 and at its other end portion to the post 253. The spring 254 is in contact with outer annular surface 555 of a bearing generally indicated at 556. The bearing 556 has an annular flange 557 and a through-hole 558. A screw 559 extends through the hole 558 and is threadably received in an axial hole 560 in the bearing 550. The gear segment 231 has a latch shoulder 561 with which a latch or pawl generally indicated at 562 cooperates. The latch 562 is shown to be one-piece molded plastics construction and has a body 563 pivotally mounted at one end portion on a pin or post 564. The body 563 has a tooth 565 its the other end portion. A leaf spring or spring finger 566 is connected to the other end portion of the body and abuts a pin or post 567. Thus, the tooth 565 is disposed between the posts 564 and 567. The latch 562 also has a cam 568 with which a pin or driver 569 (FIGS. 1, 11 and 13) formed integrally with the gear segment 229 cooperates. In the initial position (FIG. 3) of the gear assembly 172, the spring 554 urges a shoulder 570 of the gear segment 231 into abutment with a shoulder 572 of the gear segment 229. The latch tooth 565 engages the shoulder 561 to prevent rotation of the gear segment 231 in the opposite direction. When the user grips the actuator 222, the gear segment 227 drives the gear segment 229 relative to the gear segment 231. As the gear segment 229 continues to rotate, the spring 554 stretches. When the driver 569 moves from the position shown in FIG. 3 through the position shown in FIG. 11 to the position shown in FIG. 13, the driver 569 has acted on the cam 268 to pivot the latch 562 counterclockwise (FIG. 13), thereby releasing the tooth 565 from engagement with the shoulder 561 allowing the spring 554 to drive the gear segment 231 clockwise (FIG. 13) to urge the print head 170 into printing cooperation with the platen 174. By use of this arrangement, the force with which the print head 170 is driven into cooperation with the platen 174 is essentially independent of the rate at which the user moves the actuator 222. When the actuator 222 is released the return spring assembly 225 returns the actuator 222, the gear segments 229 and 231, and the print head 170 to their initial positions. The tooth 565 has a cam face 573. When the gear section 231 returns to its initial position, portion 574 of the gear segment 231 cooperates with the cam surface 573 to urge the pawl 562 counterclockwise (FIG. 11) to enable the tooth 565 to again be in latching engagement with the shoulder 561 in the position of FIG. 3. As indicated from FIG. 12, the arrangement for providing a lost-motion connection between the gear segments 229 and 231 is relatively simple. Moreover, this arrangement enables the positional relationship of the ratchet wheel to be varied relative to the feed wheel to vary the position to which the labeler is advanced relative to the plate 174 and the delaminator 175.
With reference to FIGS. 15 and 16 there is shown an alternative embodiment of the invention. Gear segments 229a and 231a are shown in their initial positions. The gear segment 229a has a flange 575 against which shoulder 576 of the gear segment 231a abuts. A compression spring 577 is received in pockets 578 and 579. The spring 277 bottoms in the pockets 278 and 279. When the gear segment 229a is pivoted clockwise (FIG. 15) due to the action of the actuator 222, the driver 569 cooperates with the cam 568 to trip the latch 562 and thus urge the print head 170 into printing cooperation with the platen 174.
With reference to FIG. 4, the pair of ball tracks 192 and 195 and the respective ball bearing 197 are disposed at one side of the opening 190 and the pair of ball tracks 193 and 196 and the respective ball bearing 198 are disposed at one side of the other opening 191. A frame section 580 of the frame plate 155 is disposed between the cutouts 190 and 191. The print head 170 is provided with a pair of members 582 and 583 which straddle the frame section 580 to prevent the print head 170 from becoming dislocated with respect to the frame plate 155, as for example when the labeler 150 is dropped. The member 583 fits underneath a lip 584 and is connected to the print head 170 by a screw 584. There is sufficient clearance between the frame section 580 and the members 582 and 583 to avoid scraping or sliding action therebetween, but the members 582 and 583 are close enough to prevent the print head 170 from popping out of the frame 155 when the labeler is dropped.
Reference may be made to the disclosure in U.S. Pat. No. 3,957,562 for further details of construction and operation, the disclosure of said patent being incorporated herein by reference.
Other embodiments and modifications of this invention will suggest themselves to those skilled in the art, and all such of these as come within the spirit of this invention are included within its scope as best defined by the appended claims.
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Disclosed is a hand-held labeler or apparatus for printing and applying pressure sensitive labels. The apparatus has a housing, a rigid, metal, frame plate mounted by the housing, a platen and a cooperating print head, a delaminator for delaminating printed labels from the web of supporting material on which the labels are carried, an applicator for applying the printed labels, a feed wheel having teeth for engaging and advancing the web, a manually operable actuator drivingly connected to the feed wheel and the print head, a brake, and an ink roll for inking the print head. The apparatus also includes a feed wheel assembly having a feed wheel driven by a pawl and ratchet mechanism. The pawl and ratchet mechanism is adjustably connected to the feed wheel. There is also disclosed an arrangement by which the print head can be tripped or fires after the actuator is moved through a predetermined distance. The apparatus has gears which are coupled through a lost-motion connection. When the actuator and one of the gears have moved through a predetermined distance a spring is released to cause the other gear to move the print head into printing cooperation with the platen.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an orally consumable film for delivering breath freshening agents to the oral cavity and in particular a consumable film having breath freshening properties enhanced by the presence of enzymes incorporated in the film.
[0003] 2. The Prior Art
[0004] Halitosis, the technical term for breath malodor, is an undesirable condition. Breath malodor results when proteins, particles from food, and saliva debris are decomposed by mouth bacteria. The tongue, with its fissures and large, bumpy surface area, retains considerable quantities of food and debris that support and house a large bacterial population. Under low oxygen conditions, the bacteria form malodorous volatile sulfur compounds (VSC)—such as hydrogen sulfide and methyl mercaptans.
[0005] Bacteria thrive on the tongue. For the most part, the bacteria are a part of a protective bio-film that essentially renders them resistant to most treatments. Few people clean their tongue after brushing, even though it's been shown that as much as 50 percent of the mouth's bacteria can be found here. Additionally, for many people, brushing or scraping the tongue is difficult because of the gag reflex. Therefore, cleaning the tongue non-mechanically is highly desirable for those who are unable to do so with a mechanical device.
[0006] It is known to the art to use consumable water soluble or dispersible films adapted to disintegrate in the oral cavity which films contain flavoring agents for delivering breath freshening agents to mask or reduce bacteria caused breath malodor. For example, PCT application number WO 00/18365 discloses a breath freshening film adapted to dissolve in the mouth of the user, the film being comprised of a water soluble polymer such as pullulon or hydroxypropylmethyl cellulose and an essential oil selected from thymol, methyl salicylate, eucalyptol and menthol.
[0007] U.S. Pat. No. 4,713,243 discloses a film for delivering therapeutic agents to the oral cavity composed of a water soluble polymer matrix of a hydroxypropyl cellulose, a homopolymer of ethylene oxide, the film having incorporated therein a pharmaceutically effective amount of medicament for the treatment of periodontal disease.
[0008] U.S. Pat. No. 5,354,551 discloses a water soluble film presegmented into dosage units, the film containing conventional toothpaste ingredients and formulated with swellable polymers such as gelatin and corn starch as film forming agents which upon application to the oral cavity disintegrate, to release an active agents incorporated in the film.
[0009] U.S. Pat. No. 6,177,096 discloses a film composition containing therapeutic and/or breath freshening agents for use in the oral cavity prepared from a water soluble polymer such as hydroxypropylmethyl cellulose, hydroxypropylcellulose and a polyalcohol such as glycerol, polyethylene glycol.
[0010] Although the prior art water soluble consumable films have provided breath freshening benefits, the art continually seeks to enhance such benefits.
SUMMARY OF THE INVENTION
[0011] In accordance with the present invention there is provided orally consumable film composition to deliver agents to the oral cavity effective to reduce breath malodor wherein the antimalodor efficacy of the film is significantly enhanced by incorporating an enzyme into the film matrix.
[0012] Enzymes are quaternary proteins and their structure, function, and stability are sensitive to processing conditions and chemical environments and often denature in such environments, for example, at elevated temperatures, that is, temperatures substantially above 45° C. It was therefore unexpected that a protease enzyme incorporated into a film matrix adapted to disintegrate in an oral cavity environment retained its proteolytic activity, during film manufacture at elevated temperatures and residence times involved in the film manufacturing process.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The film of the present invention comprises a consumable water soluble or dispersible film containing an antimalodor enzyme. The film can further comprise water, additional film forming agents, flavor agents, plasticizing agents, other antimalodor agents, emulsifying agents, coloring agents, sweeteners and fragrances.
[0014] Enzymes
[0015] The enzymes useful in the practice of the present invention include enzymes extracted from natural fruit products well known protein substances within the class of proteases, which breakdown or hydrolyze proteins (proteases) other useful enzymes include lapases, glycoamylases and carbohydrases.
[0016] The proteolytic enzymes are obtained from natural sources or by the action of microorganisms having a nitrogen source and a carbon source. Examples of proteolylic enzymes useful in the practice of the present invention include papain, bromelain, chymotrypsin, ficin and alcalase. The enzymes are included in the film compositions of the present invention at a concentration of about 0.1 to about 5% by weight and preferably about 0.2 to about 2% by weight.
[0017] Papain obtained from the milky latex of the Papaya tree is the proteolytic enzyme preferred for use in the practice of the present invention and is incorporated in the film matrix of the present invention in an amount of about 0.1 to about 10% by weight and preferably about 0.5 to about 5% by weight, the papain having an activity of 150 to 939 MCU per milligram as determined by the Milk Clot Assay Test of the Biddle Sawyer Group (see J. Biol. Chem., vol. 121, pages 737-745).
[0018] Additional enzymes which may be useful in the practice of the present invention include protein substances within the class of proteases, which breakdown or hydrolyze proteins (proteases). These proteolytic enzymes are obtained from natural sources or by the action of microorganisms having a nitrogen source and a carbon source. Examples of alternative proteolylic enzymes useful in the practice of the present invention include bromelain, chymotrypsin, ficin and alcalase.
[0019] An additional enzyme which can be formulated individually or in combination with the protease enzyme papain is glucoamylase. Glucoamylase is a saccharifying glucoamylase of Aspergillus niger origin cultivated by fermentation. This enzyme can hydrolyze both the alpha-D-1,6 glucosidic branch points and the alpha-1,4 glucosidic bonds of glucosyl oligosaccharides. The product of this invention comprises about 0.001 to 2% of the carbohydrase and preferably about 0.01 to 0.55% by weight. Additional carbohydrases useful in accordance with this invention are glucoamylase, alpha and beta-amylase, dextranase and mutanase. Other enzymes which may be used in the practice of the present invention include other carbohydrases such as alpha-amylase, beta-amylase, dextranase and mutanase and lipases such as plant lipase, gastric lipase, pancreatic lipase, pectinase, tannase lysozyme and serine proteases.
[0020] The lipase enzyme is derived from a select strain of Aspergillus niger , exhibiting random cleaving of the 1,3 positions of fats and oils. The enzyme has maximum lipolytic activity at pH 5.0 to 7.0 when assayed with olive oil. The enzyme has a measured activity of 120,000 lipase units per gram. The lipase may be included in the dentifrice composition at a concentration of about 0.010 to about 5.0% by weight and preferably about 0.02 to about 0.10% by weight.
[0021] Other suitable enzymes which can comprise the present invention include lysozyme, derived from egg white, which contains a single polypeptide chain crosslinked by four disulfide bonds having a molecular weight of 14,600 daltons. The enzyme can exhibit antibacterial properties by facilitating the hydrolysis of bacterial cell walls cleaving the glycosidic bond between carbon number 1 of N-acetylmuramic acid and carbon number 4 of N-acetyl-D-glucosamine, which in vivo, these two corbohydrates are polymerized to form the cell wall polysaccharide. Additionally, pectinase, an enzyme that is present in most plants facilitates the hydorlysis of the polysaccharide pectin into sugars and galacturonic acid.
[0022] Film Matrix
[0023] Water soluble or dispersible film forming agents used to form the film matrix of the present invention include water soluble polymers such as polyvinyl pyrrolidone, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxyalkyl celluloses such as hydroxypropyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, sodium alginate, guar gum, xanthan gum as well as water dispersible polymers such as polyacrylates, carboxyvinyl copolymers, methyl methacrylate copolymers and polyacrylic acid. A low viscosity hydropropylmethyl cellulose polymer (HPMC) having a viscosity in the range of about 1 to about 40 millipascal seconds (mPa·s) as determined as a 2% by weight aqueous solution of the HPMC at 20° C. using a Ubbelohde tube viscometer is a preferred film matrix material. Preferably the HPMC has a viscosity of about 3 to about 20 mPa·s at 20° C. such HMPC is available commercially from the Dow Chemical Company under the trade designation Methocel E5 Premium LV. Methocel E5 Premium LV is a USP grade, low viscosity HPMC having 29.1% methoxyl groups and 9% hydroxyproxyl group substitution. It is white or off-white free flowing dry powder. As a 2 weight % solution in water as measured with Ubbelohde tube viscometer it has a viscosity of 5.1 to mpa·s at 20° C.
[0024] The hydroxyalkyl methyl cellulose is incorporated in the film composition in amounts ranging from about 10 to about 60% by weight and preferably about 15 to about 40% by weight.
[0025] Cold water dispersible, swellable, physically modified and pregelatinized starches are particularly useful as texture modifier to increase the stiffness of the hydroxyalkyl methyl cellulose polymer films of the present invention. To prepare such starch products, the granular starch is cooked in the presence of water and possibly an organic solvent at a temperature not higher than 10° C. higher than the gelatinization temperature. The obtained starch is then dried.
[0026] Pregelatinized corn starch is available commercially. A preferred starch is available under the trade designation Cerestar Polar Tex-Instant 12640 from the Cerestar Company. This Cerestar starch is a pregelaterized, stabilized and crosslinked waxy maize starch. It is readily dispersible and swellable in cold water. In its dry form, it is a white free flowing powder with an average particle size no greater than 180 micrometers and 85% of the particles are smaller than 75 micrometers. It has a bulk density of 44 lbs/ft 3 .
[0027] The pregelatinized starch may be incorporated in the film matrix of the present invention in an amount ranging from about 5 to about 50% by weight and preferably about 10 to about 35% by weight.
[0028] Emulsifiers
[0029] Emulsifying agents are incorporated in the film matrix ingredients to promote homogeneous dispersion of the ingredients. Examples of suitable emulsifiers include condensation products of ethylene oxide with fatty acids, fatty alcohols, polyhyrric alcohols (e.g., sorbitan monostearate, sorbitan oleate), alkyl phenols (e.g., Tergitol) and polypropyleneoxide or polyoxybutylene (e.g., Pluronics); amine oxides such as dimethyl cocamine oxide, dimethyl lauryl amine oxide and cocoalkyldimethyl amine oxide polysorbates such as Tween 40 and Tween 80 (Hercules), glyceryl esters of fatty acid (e.g., Arlacel 186). The emulsifying agent is incorporated in the film matrix composition of the present invention at a concentration of about 0.1 to about 3% by weight and preferably about 0.2 to 1.0% by weight.
[0030] Flavor Agents
[0031] Flavor agents that can be used to prepare the film of the present invention include those known to the art, such as natural and artificial flavors. These flavor agents may be chosen from synthetic flavor oils and flavoring aromatics, and/or oils, oleo resins and extracts derived from plants, leaves, flowers, fruits and so forth, and combinations thereof. Representative flavor oils include: spearmint oil, cinnamon oil, peppermint oil, clove oil, bay oil, thyme oil, cedar leaf oil, oil of nutmeg, oil of sage, and oil of bitter almonds. These flavor agents can be used individually or in admixture. Commonly used flavor include mints such as peppermint, artificial vanilla, cinnamon derivatives, and various fruit flavors, whether employed individually or in admixture. Generally, any flavoring or food additive, such as those described in Chemicals Used in Food Processing, publication 1274 by the National Academy of Sciences, pages 63-258, may be used. The amount of flavoring agent employed is normally a matter of preference subject to such factors as flavor type, individual flavor, and strength desired.
[0032] Generally the flavor agent is incorporated in the film of the present invention in an amount ranging from about 2.0 to about 30% by weight and preferably about 6 to about 25% by weight.
[0033] Sweeteners useful in the practice of the present invention include both natural and artificial sweeteners. Suitable sweetener include water soluble sweetening agents such as monosaccharides, disaccharides and plysaccharides such as xylose, ribose, glucose (dextrose), mannose, glatose, fructose (levulose), sucrose (sugar), maltose, water soluble artificial sweeteners such as the soluble saccharin salts, i.e., sodium or calcium saccharin salts, cyclamate salts dipeptide based sweeteners, such a L-aspartic acid derived sweeteners, such as L-aspartyl-L-phenylalaine methyl ester (aspartame) and sucralose.
[0034] In general, the effective amount of sweetener is utilized to provide the level of sweetness desired for a particular composition, will vary with the sweetener selected. This amount will normally be about 0.01% to about 2% by weight of the composition.
[0035] The compositions of the present invention can also contain coloring agents or colorants. The coloring agents are used in amounts effective to produce the desired color and include natural food colors and dyes suitable for food, drug and cosmetic applications. These colorants are known as FD&C dyes and lakes. The materials acceptable for the foregoing spectrum of use are preferably water-soluble, and include FD&C Blue No.2, which is the disodium salt of 5,5-indigotindisulfonic acid. Similarly, the dye known as Green No.3 comprises a 15 triphenylmethane dye and is the monosodium salt of 4-[4-N-ethyl-p-sulfobenzylarnino) diphenyl-methylene]-[1-N-ethy 1-N-sulfonium benzyl)-2,5-cyclo-hexadienimine].A full recitation of all FD&C and D&C dyes and their corresponding chemical structures may be found in the Kirk-Othmer Encyclopedia of Chemical Technology, Volume 5, Pages 857-884, which text is accordingly incorporated herein by reference.
[0036] Agents known to exhibit antimalodor activity can be incorporated into the film composition of the present invention including zinc gluconate, zinc citrate and/or alpha ionone. These agents function to aid in reducing mouth odor and work in combination with enzymes to reduce volatile odor causing bacterial sulfur compounds. These agents may be incorporated in the film matrix of the present invention at a concentration of about 0.1 to about 2.0% by weight and preferably about 0.15 to about 0.5% by weight.
[0037] In preparing the film composition according to the present invention, a water soluble or water dispersible film forming agent such as hydroxyalkylmethyl cellulose is dissolved in a compatible solvent such as water heated to about 60° C. to about 71° C. to form a film forming composition. Thereafter, there is optionally added in the sequence, a second film forming agent such as starch, sweetener, surfactant, flavor and enzyme compound to prepare a film ingredient slurry.
[0038] The slurry is cast on a releasable carrier and dried. The carrier material must have a surface tension which allows the film solution to spread evenly across the intended carrier width without soaking to form a destructive bond between the film and the carrier substrate. Examples of suitable carrier materials include glass, stainless steel, Teflon and polyethylene impregnated paper. Drying of the film may be carried out at elevated temperatures by transversing through a zoned dryer at approximately 20-30 inches/min at temperatures ranging for example from, 70° C. to 120° C., using a drying oven, drying terminal, vacuum drier, or any other suitable drying equipment for residence times which do not adversely effect the ingredients of which the film is composed.
[0039] To insure the stability of the enzyme during film manufacture and protect the enzyme tertiary protein structure, the enzyme is predispersed in a hydrophobic diluent or dispersant such as a vegetable oil, including canola oil, corn oil, peanut oil, a polyethylene glycol or a silicone oil to provide a protective shield for the enzyme during the manufacturing process.
[0040] The film once formed is segmented into dosage units by die-cutting or slitting-and-die cutting. The segmented film has a strip width and length corresponding to about the size of a postage stamp, generally about 12 to about 30 millimeter in width and about 20 to about 50 millimeters in length. The film has a thickness ranging from about 15 to about 80 micrometers, and preferably about 40 to 60 micrometers.
[0041] The film is shaped and sized to be placed in the oral cavity. The film is flexible and adheres to a surface in the mouth, usually the roof of the mouth or the tongue, and quickly dissolves, generally in less than 25-60 seconds.
[0042] The present invention is illustrated by the following examples.
EXAMPLE 1
[0043] A breath freshening film designated Composition A was prepared by using the ingredients listed in Table I below. In preparing the film, the HMPC polymer ingredient (Methocel E5LV) was added at a temperature of 70° C. to 90° C., to half the amount of total deionized water used, and the solution stirred for 20 minutes at a slow speed using a IKA Labortechnik Model RW20DZMixer. The remaining amount of water maintained at room temperature (21° C.) was then added and the mixing continued for 40 minutes. To this solution was added the corn starch ingredient (Cerestar Polar Tex Instant 12640) and the mixture stirred for an additional 20 minutes until the starch was completely dispersed and a homogeneous mixture was formed. To this mixture was added sucralose and mixed for 10 minutes after which the emulsifier Tween 80 was added and mixed for an additional 5 minutes. Thereafter flavor was thoroughly mixed for an additional 30 minutes to form a slurry emulsion to which as a final step the enzyme papain dispersed in canola oil was slowly added until evenly dispersed in the film ingredient slurry. The emulsion was then cast on a polyethylene coated paper substrate and passed through a 6 zone oven at a rate of 20-30 in/min and dried at 115° C. to form a solid thin (40 um thick) translucent film.
TABLE I Ingredients Composition A (Wt. %) Water 77.5 HPMC 8.55 Corn starch 4.00 Flavor 6.00 Tween 80 0.50 Canola Oil 1.00 Sucralose 0.20 Papain 1.00
[0044] Human clinical studies determined that the film of Composition A significantly reduced the level of bacterial species on the tongue surface responsible for the presence of oral malodor for up to 60 minutes post application use when compared identical compositions prepared without the enzyme papain.
[0045] The evaluation of the quantity of bacteria responsible for oral malodor was determined, in-situ, in a tongue micro-flora study. The film composition was tested for its ability to reduce the micro-flora on the back of the tongue, especially those species responsible for the generation of H 2 S. The study required subjects to swab one side of the back of the tongue for bacterial collection at baseline and the alternate back side of the tongue 1 hour after the first application of the Composition A film to the tongue which remained on the tongue for a time sufficient for the film to dissolve and disintegrate. The collected samples were plated onto lead acetate agar media for the selection of H 2 S-forming bacteria as well as blood agar media to determine the total level of bacteria present on the tongue and incubated under anaerobic conditions at 37° C. After 72 hours, colony-forming units (CFU) of H 2 S-forming bacteria, and total bacterial colony-forming units were enumerated. The mean colony forming unit results were used to calculate percent reduction from baseline.
[0046] The results of the in-vivo tongue micro-flora study are recorded in Table II below. For purposes of comparison a the procedure of Example 1 was repeated with the exception that a film composition substantially identical to Composition A (designated Composition B) was used except that papain was not present in the film composition. The antimalodor efficacy of Composition B was also assessed in the microflora test used to evaluate Composition A. These results are also recorded in Table II.
TABLE II 1 Hour Post Film Baseline Application (Mean CFU) (Mean CFU) % Reduction Malodor Total Malodor Total Malodor Total Com- Tongue Tongue Tongue Tongue Tongue Tongue position Bacteria Bacteria Bacteria Bacteria Bacteria Bacteria A 4.5*10 5 8.2*10 5 6.9*10 4 8.9*10 4 84.7 89.2 B 1.1*10 5 2.1*10 5 2.2*10 5 4.7*10 5 Bacterial Bac- Growth terial Growth
[0047] The results recorded in Table II indicate that the papain containing film Composition A of the present invention, unexpectedly provided a substantially reduced quantity of tongue bacteria as compared to the comparative film Composition B which did not contain the enzyme papain.
[0048] The film Composition A of the present invention was also found to control volatile sulfur compound (VSC) formation in a clinical breath/VSC study involving the same human subjects who participated in the tongue microflora study. Breath-odor was measured using a Halimeter™ at baseline and at 1 hour after film application to the tongue. The results recorded in Table III are consistent with data represented in Table II indicating a greater reduction in breath VSC's responsible for oral malodor when compared to the comparative film Composition B in which papain enzyme was not present in the film.
TABLE III Clinical study involving oral malodor reduction. 1 Hour Post Baseline Film Application % Reduction of Composition VSCin ppb* VSCin ppb Malodor A 390 290 28.0 B 520 490 7.0
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An orally consumable film composition for delivering breath freshening agents to the oral cavity which is rapidly dissolvable or dispersible in the oral cavity, the composition being comprised of a homogeneous mixture of a water dispersible film forming polymer and an enzyme.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. patent application Ser. No. 10/642,315, filed Aug. 15, 2003 now U.S. Pat. No. 6,946,314, which in turn is a continuation in part of U.S. patent application Ser. No. 10/038,890, filed on Jan. 02, 2002 now U.S. Pat. No. 6,673,694, the disclosure of which is incorporated herein by reference. U.S. patent application Ser. No. 10/038,890 claims priority to U.S. Provisional Patent Application Ser. No. 60/259,282, filed Jan. 2, 2001. The present application also claims priority of U.S. Provisional Patent Application Ser. No. 60/403,796, filed on Aug. 15, 2002. Each of the aforementioned patent application is incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates generally to MicroElectroMechanical Systems (MEMS), in particular, to methods for microfabricating MEMS devices on Silicon-On-Insulator (SOI) wafers.
BACKGROUND OF THE INVENTION
The rapidly emerging field of MicroElectroMechanical Systems (MEMS) has penetrated a wide array of applications, in areas as diverse as automotives, inertial guidance and navigation, microoptics, chemical and biological sensing, and biomedical engineering. Use of Silicon-On-Insulator (SOI) material is rapidly expanding in both microelectronic and MEMS applications, because of increasing demand for tight limits on wafer specifications, the low cost of SOI, its process flexibility, radiation hardness and compatibility with high-level integration. Significant benefits may be realized by utilizing SOI material to fabricate inertial sensors, chemical and biological sensors, optoelectronic devices, and a wide range of mechanical structures such as microfluidic and microoptical components and systems. In spite of its many advantages, however, use of SOI wafers to build MEMS devices is not widespread, largely because of difficulties in processing the material.
Prior methods for fabricating MEMS devices using a bonded handle wafer include the dissolved wafer process, in which silicon is bonded to glass and the silicon is dissolved away to reveal an etch-stop layer. This etch-stop layer typically comprises a heavily-doped boron-diffused or boron-doped epitaxial layer, but may also consist of a SiGe alloy layer. However, methods that involve the use of a heavily-boron-doped etch stop suffer in several respects, including poor process control, high defect densities, limitations on ultimate thickness of devices, and incompatibility with microelectronic device integration. Insertion of a SiGe alloy layer resolves several of these limitations, but that method suffers from relatively low deposition rates and material property issues. SOI micromachining has demonstrated that a limited number of device types may be successfully constructed, but the build quality is lacking and many design constraints exist.
The principal constraint involves the problems encountered when performing deep reactive-ion-etching (RIE) of the silicon device layer on top of the oxide interlayer; the RIE process tends to attack the underside of the silicon device layer due to charging of the dielectric layer. Steps have been taken by RIE equipment vendors to resolve this problem, and such methods have mitigated these etch effects.
This requirement has led to the development of alternative SOI processes. However, these alternative processes encounter stringent design rules related to pressure differentials across the thin oxide interlayer. Survival of the oxide interlayer is important for the success of alternative SOI processes, but no solution to this problem has previously been proposed.
Thus, there is a need in the art for a method that relieves the constraints for SOI processing.
SUMMARY OF THE INVENTION
The invention provides a general fabrication method for producing MicroElectroMechanical Systems (MEMS) and related devices using Silicon-On-Insulator (SOI) material. The method includes providing a Silicon-On-Insulator (SOI) wafer, which has (i) a handle layer, (ii) a dielectric layer, which preferably is a SiO 2 layer, and (iii) a device layer, wherein a mesa etch has been made on the device layer, providing a substrate (such as glass or silicon), where a pattern has been etched onto the substrate, bonding the SOI wafer to the substrate, whereby the etched device layer faces the patterned surface of the substrate, removing the handle layer of the SOI wafer, removing the dielectric layer of the SOI wafer, and etching the device layer of the SOI wafer to define the MEMS device.
The method described above is generally called Bonded and Etch Back Silicon-On-Insulator (BESOI). In the BESOI method, the structure etching is performed after the SiO 2 layer is removed, so that when the handle layer is removed by wet or dry etching, the SiO 2 layer is supported by the device layer, thus the SiO 2 layer can function as an etch stop, and no chemicals penetrate the SiO 2 layer to the device region to damage the device when the SOI wafer handle Si is removed.
In one preferred embodiment, the substrate is etched with a predetermined pattern, and a metal layer is deposited and metal runners are formed on the patterned substrate. In another preferred embodiment, instead of using a glass substrate, a second SOI wafer is provided to be used as a substrate. The highly doped device layer of the second SOI wafer is etched and patterned to form electrically conductive Silicon lines, which take the place of metal lines. The patterned device layer of the first SOI wafer is then bonded to the patterned device layer of the second SOI wafer. Then, the handle layer and the dielectric layer of the first SOI wafer are removed, and the device layer of the first SOI wafer is further etched to define the MEMS device.
The method of the invention provides (1) the ability to micromachine devices on SOI substrates without design constraints for structure spacing, etch gaps, oxide thickness or other features, and (2) a flexibility for handle wafer type and bonding process. This invention also addresses several of the previous barriers to general use of SOI material for MEMS and associated applications. First, the invention enables the use of SOI wafers to build a wide array of device types that were previously only feasible using standard boron etch stop technology. Second, the method allows for the use of RIE etch technology to produce high-quality structures on devices bonded everywhere to a silicon dioxide buried layer. Third, the invention relieves all of the design constraints previously required for SOI structures, including the spacing between structural elements, spacing between the device and the edge of the die, and special requirements for atmospheric conditions during bonding of SOI wafers to handle wafers.
The invention also provides intermediate structures in the general fabrication method. The intermediate structures are mechanically stable, though they contain internal cavities formed by the etched SOI wafer and the substrate. The cavities can be of various shapes and sizes.
In one embodiment, the intermediate structure have an access port in the substrate. The intermediate structures can be made using components with arbitrary thickness and arbitrary doping.
The invention further provides a method for making an accelerometer, using the methods of the invention.
In one preferred embodiment, the substrate is provided with access ports to equalize the pressure between the internal cavities and outside of the wafer sandwich. In another preferred embodiment, the process of bonding the SOI wafer and the substrate is performed at a pressure less than atmospheric pressure. Thus, some gas can be present in the cavities formed between the Si and the substrate, but the gas pressure is not great enough to cause devices to explode during a subsequent potassium hydroxide (KOH) etch to remove the handle layer. This step avoids the need for drilling holes in the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side drawing showing a prior art single depth microfabrication process;
FIG. 2 is a schematic side drawing showing the process steps prior to substrate bonding;
FIG. 3 is a schematic side drawing showing the process steps of the invention for glass substrate fabrication;
FIG. 4 is a schematic side drawing showing bonding, wafer thinning and oxide dielectric removal;
FIG. 5 is a schematic side drawing showing the baseline BESOI process sequence;
FIG. 6A is a schematic view of a prior art device structure showing that the underside of the Si beam is etched;
FIG. 6B is a schematic view of a device structure showing that the Si beam is protected from underside etching;
FIG. 7 is a schematic side view showing the baseline BESOI process sequence, wherein an SOI wafer is used as a substrate;
FIG. 8 is a set of electron micrographs showing (a) epitaxial comb fingers and (b) the baseline BESOI comb fingers; and
FIG. 9 is an electron micrograph showing the phenomenon of RIE lag, where narrow trenches etch more slowly.
DETAILED DESCRIPTION OF THE INVENTION
First embodiment. An ALTSOI embodiment of the invention is now described. A standard SOI wafer 10 is provided, which is shown in FIG. 2 , and which comprises a handle layer 12 , a dielectric layer 14 usually consisting of silicon dioxide, and a device layer 16 (see, FIG. 2 a ). Such wafers are commercially available from many sources, and are fabricated using wafer bonding, SIMOX technology, Smart-Cut methods, or other processes. Wafers can also be obtained from a large number of vendors of standard semiconductor material, and are sawn and polished to provide precise dimensions, uniform crystallographic orientation, and highly polished, optically flat surfaces.
Parameters for the three layers of the SOI wafer are determined by the user. Typically, the handle wafer is of sufficient thickness for handling purposes, without other requirements. The dielectric layer is thick enough for electrical isolation and effective etch-stop action, yet thin enough so as not to cause severe bowing of the SOI wafer. The device layer parameters are important, as they will translate directly into properties of the resulting structure. Thickness of the device layer determines the device thickness (including any gap that may be machined between the device and the substrate). Electrical resistivity, carbon and oxygen content, growth technique, crystallographic orientation and other wafer parameters are selected based on the properties requited of the end product. Surface finish should be highly polished. The interface between the dielectric and device layers should not have voids.
Once the SOI wafer parameters have been selected and the material obtained, processing of the wafer begins. FIG. 2 shows the primary steps involved in preparing the SOI wafer for bonding to a substrate wafer. First the SOI wafer is cleaned and patterned for the “mesa” etch. Here mesas are preserved in the device layer and the background is etched back, so that the final structure, when bonded to a substrate, has regions which are directly bonded (the mesas) and regions suspended above the planar surface of the substrate (i.e., everywhere else on the wafer; see, FIG. 2 b ). The mesa etch may be performed using KOH or other etchants.
In one preferred embodiment, once the mesa etch has been performed, the wafer is cleaned and patterned for the “structural” etch (see, FIG. 2 c ). Typically, the structural etch is a Deep Reactive Ion Etch (DRIE) process, in which high aspect ratios may be desired (Ayon A A et al., Mat. Res. Soc. Symp. Proc. 546: 51 (1999); Ayon A A et al., J. Vac. Sci. Tech. B 18: 1412 (2000)). Since the process etches straight down to the dielectric layer, which is bonded everywhere to the device layer, techniques designed to prevent plasma etching problems at the dielectric—device interface become very effective.
The micromachining of silicon can be observed by the use of epifluorescence microscopy or by the use of metallurgic microscope. Alternatively, the micromachining can be observed by an electron microscope, such as a scanning electron microscope (SEM).
The SOI wafer that has been patterned and etched for both the mesa and structural layers is then bonded to a substrate. The substrate can be glass, silicon or other equivalently workable material.
In one embodiment, the fabrication steps for a glass substrate 20 are those outlined in FIG. 3 . First, the glass wafer 20 is cleaned and patterned for the electrode pattern. Here, the electrode pattern is composed of multilevel metallization. The glass wafer 20 is then recess-etched, and, without removing the photoresist, a blanket sputter of the multilevel metallization is performed. Finally, the wafer undergoes “lift-off”, where metal not applied directly to the substrate is removed.
Note that in FIG. 3 d , an additional step has been added; the formation of access ports 22 in the glass substrate 20 . The advantage for this process step is described below, where the substrate wafer is bonded to the processed SOI wafer. These access ports 22 may be etched, or more preferably, mechanically or ultrasonically drilled through the glass substrate. The spacing of these holes is determined by the die size and by the presence and distribution of bonded seals between the SOI wafer and the substrate. Since the purpose of the access ports is to equalize the pressure between the internal cavities and outside of the wafer sandwich, at least one such port must be positioned within each region sealed by bonding. Typically, these regions coincide with the die size, so that each device is isolated from all others by a bonded structure known as a seal ring.
Once the SOI and glass wafers have been processed, they are bonded together. This is usually accomplished by anodic bonding. The remainder of the process sequence is illustrated in FIG. 4 . Note that the presence of the access port ensures that the inner cavities are at the same pressure as the external environment.
Without the access port, the quantity of gas inside the cavity is fixed when the bond is formed. Applying the ideal gas law, the pressure inside the cavity p=nRT/V, where n is the number of moles of gas present (fixed), V is the volume of the cavity (fixed), R is the universal gas constant, and T is the temperature. If the bonding is performed at 300° C. and 1 atmosphere, for instance, the pressure inside the cavity at room temperature is (293/573) atm˜0.5 atm. Therefore, in room ambient, the cavity is in an underpressure situation, while in a vacuum chamber, it is at an overpressure situation. For any specific pressure condition during bonding, once the wafer sandwich has cooled, the pressure inside the cavity can be different from that of the outside world. Analysis indicates that such a pressure differential will lead to fracture of the oxide interlayer. Use of an access port resolves the problem of the pressure differential.
Once the wafers have been bonded together, with the device side of the SOI wafer bonded to the metallized side of the glass, the handle layer of the SOI wafer must be removed. Without an access port, this material may be removed in a wet chemical etch or by a dry plasma etch. With the access port present, only the dry process is used. For example, a RIE tool may be used to remove the handle silicon layer. One required feature of RIE process tool is that it enables the plasma removal to occur with equalized pressure across the oxide dielectric. The other required feature is that plasma gases cannot gain access to the cavity through the port; otherwise, attack of structural layers would ensue.
The final step in the process is removal of the oxide dielectric. In this as well as previous embodiments, removal of the dielectric layer must be performed using a dry plasma etch process, so as not to attack the bulk glass and metallization on the topside of the device. Once the dielectric has been removed, the final structure is produced.
This structure is expected to have excellent build quality, as it benefits from several significant process improvements: (1) high material quality through use of virgin SOI material rather than highly doped layers; (2) very high fidelity DRIE processing, due to fully bonded device and oxide dielectric layer during the etch process, and newly-developed vendor equipment and processes designed specifically for these applications; (3) high quality access port holes, drilled using ultrasonic methods which produce smooth walls without stress concentrations; (4) complete flexibility in wafer bonding process, without concern for ambient conditions and resulting pressure differentials; and (5) dry plasma etch wafer thinning process, which allows for pressure equalization across oxide dielectric, eliminating possible exposure of device layer to etchant.
One group of former methods for fabricating micromachined structures in silicon involves the use of an etch-stop such as heavily-doped boron layers or SiGe layers. The method of the invention has several distinct advantages over that family of techniques, including increased process flexibility without the requirement for heavy doping, a higher-quality silicon device layer, and improved process control.
Alternative embodiments. Alternate methods for the invention include, but are not limited to (1) the use of silicon or other crystalline substrates rather than a glass substrate, (2) anodic bonding using a thin layer of sputtered PYREX® rather than a full glass wafer, (3) fusion bonding rather than anodic bonding of the lower handle wafer, etching or other processes rather than ultrasonic drilling, (4) alternate means for removing the SOI handle layer, and (5) the use of materials other than silicon and silicon dioxide for the device layer and etch-stop layer, respectively. Wafers made from PYREX®, other borosilicate glass, or other glasses can also be procured and inserted into micromachining processes, with alternative processes used to etch the glassy materials. See, published PCT patent application WO 00/66036; Kaihara et al, Tissue Eng 6(2): 105–17 (April 2000).
Plasma etching provides the ability to control the width of etched features as the depth of the channel is increased. Wet chemical processes typically widen the trench substantially as the depth is increased, leading to a severe limitation on the packing density of features (Fruebauf J & Hannemann B, Sensors and Actuators 79: 55 (2000)). Several different plasma etching technologies have been recently developed. One of the available etch processes is know as the Bosch process.
In another preferred embodiment, the process of bonding the SOI wafer and the substrate is performed at a predetermined pressure less than atmospheric pressure, for example, 200 mTorr. Thus, some gas can be present in the cavities between the Si and the substrate, but the gas pressure is not great enough to cause devices to explode during a subsequent potassium hydroxide (KOH) etch to remove the handle layer. This step avoids the need for drilling holes in the substrate ports to equalize the pressure between the internal cavities and outside of the wafer sandwich.
In a further preferred embodiment, the handle layer of the SOI wafer is removed by a relatively fast wet etch, for example, using potassium hydroxide (KOH). The fast etching of the handle layer is terminated at a predetermined distance, e.g., about 10 μm, from the SiO 2 layer. Removal of the rest of the handle layer is preferably done by a relatively slow etch, for example, using tetramethyl ammonium hydroxide (TMAH). Thus, the etch of the rest of the handle layer is preferably performed slowly and stops well at the SiO 2 layer. This etch can also be performed using XeF 2 , which is a non-ionized, gas that has a Si:SiO 2 etch ration as high as 10,000:1. The next step in the process is removal of the SiO 2 layer. In this as well as previous embodiments, removal of the SiO 2 layer is preferably performed using an RIE dry plasma etch process, so as not to attack the bulk glass and metallization on the topside of the device. The SiO 2 can be removed in an RIE tool using a recipe designed for SiO 2 etching. This process can be performed at desired gas pressure, such as 200 mTorr, which is substantially the same as the pressure at which the bonding of the SOI wafer and the substrate is performed. Thus, a differential pressure is not applied to the SiO 2 during the RIE etch, allowing the SiO 2 to be removed without damaging the device.
The previously described method requires the mesa etching and structural etching to be performed before the SOI wafer is bonded to a substrate wafer. Once the bonding has been performed, the handle layer part of the SOI wafer is removed using a wet etch. The wet etch which removes the handle layer must stop on the thin SiO 2 layer. If the etch does not completely stop at the SiO 2 layer, the etch chemicals would penetrate the device and destroy it. Also, the structural etching, which is performed before the SOI wafer is bonded to the substrate, defines cavities in the device layer. In these cavities, there is no Si underneath the SiO 2 to mechanically support the SiO 2 layer. During the etching process for removing the handle layer, the etch chemicals may penetrate the SiO 2 layer, which has no Si support, and destroy the device under the SiO 2 layer.
FIG. 5 illustrates an alternative fabrication method, which is called Bonded and Etch Back Silicon-On-Insulator (BESOI). In the BESOI method, the structural etching is performed after the SOI wafer is bonded to the substrate, and after the handle layer and SiO 2 layer are removed. When removing the handle layer, the SiO 2 layer is supported by the underlying Si across the complete surface of the SOI wafer. Thus the SiO 2 layer functions as a good etch stop, and no etch chemicals penetrate the device region when the handle layer of the SOI wafer is removed.
The BESOI method begins with a standard SOI wafer 10 , similar to that used in the previously described SOI processes. First, the SOI wafer is cleaned and patterned for the mesa etch. The mesa etch may be performed by several methods, for example, using KOH.
The glass substrate fabrication steps are similar to the previously described methods, which are outlined in FIG. 3 . In one preferred embodiment, the glass substrate may be provided with access ports to equalize the pressure between the internal cavities and outside of the wafer sandwich.
Once the SOI and glass wafers have been processed, they are anodically bonded, with the device side of the SOI wafer bonded to the metallized side of the glass substrate. The bonding process also can be performed under a predetermined pressure, which is less than atmosphere pressure, as described above.
The handle layer of the SOI wafer is preferably removed by a relatively fast wet etch, for example, using potassium hydroxide (KOH). The etching of the handle layer is stoped at a predetermined distance, e.g., about 10 μm, from the SiO 2 layer. Removal of the rest of the handle layer is preferably done by a relatively slow etch, for example, using tetramethyl ammonium hydroxide (TMAH). The etch of the rest Si is preferably performed slowly and stops well on the SiO 2 layer. This etch can also be performed using XeF 2 , which is a non-ionized gas that has a Si:SiO 2 etch ratio as high as 10,000:1.
The next step in the process is removal of the SiO 2 layer. In this as well as previously described embodiments, removal of the SiO 2 layer is preferably performed using an RIE dry plasma etch process. The SiO 2 can be removed in an RIE tool using a conventional recipe designed for SiO 2 etching.
After the SiO 2 layer is removed, the device layer is revealed and ready for structural etching. In a preferred form of the invention, the device layer is then etched to define the device preferably by Inductively Coupled Plasma (ICP), using a Surface Technology Systems plc (STS) machine, which prevents charge build-up causing “footing”. The structural etching process may etch straight down to the glass substrate.
When the ICP etch is performed using a prior art process step, positive ions of SF 6 are generated in a region above the SOI wafer. These ions are accelerated by a negative potential applied to a bias plate upon which the SOI wafer is placed. The SF 6 ions subsequently etch the device layer of the SOI wafer. As the device layer is etched away, the underlying glass wafer is exposed. Electronic charge from the SF 6 ions may accumulate on the exposed glass. Once the exposed glass is positively charged, the positively charged incoming SF 6 ions are repelled. Their trajectory is bent such that they may etch and damage the underside of nearby Si. A diagram of this prior art process step is shown in FIG. 6A .
In accordance with the present invention, the above described prior art process step is replaced with a new process step, which avoids damage of the underside of the nearby Si of the device. With the improved step, the glass substrate is covered with a substantially uniform metal layer, which, during the etch, prevents charge build-up, as shown in FIG. 6B . Typically, gaps in metal layer are necessary to keep metal regions or lines separate. These gaps are preferably placed other than under an operable element which is to be formed by etching the device layer, or placed in areas where damage to the device will not affect the performance of the device. For example, as shown in FIG. 6B , the area directly underneath the drive or sense fencers of a MEMS device is covered by metal, and the gap between the Si and the metal is placed other than under the finger.
The ICP etch is performed after the SOI wafer is bonded to the glass substrate. The silicon, which is to be removed, is preferably not bonded to the glass, because it is very difficult for the ICP etch to remove Si, which has been bonded to the glass. To prevent the silicon, which will be removed by ICP etch, from bonding to the substrate glass, a few microns of the surface of the silicon are preferably removed before the SOI wafer is bonded to the glass wafer. The removal of the silicon can be done in the mesa etch, as shown in FIG. 2 .
FIG. 7 illustrates another alternative BESOI method of the invention, which uses highly doped silicon or other crystalline substrates rather than a glass substrate. As shown in FIG. 7 , a second SOI wafer is provided to be used as the substrate. The device layer of the second SOI wafer is etched straight down to the dielectric layer to form highly doped (and thus electrically conductive) “Si runners”, which can be used as electrically conductive lines and contacts. After the “Si runners” are formed, the first etched SOI wafer is bonded to the second substrate SOI wafer. The substrate SOI wafer can be used in all previously described methods to replace the glass substrate.
Uses of the Invention. Commercial applications for this technology include, but are not limited to, inertial sensors for the automotive and other transport businesses, chemical and biological sensors for the biomedical and environmental monitoring businesses, industrial control sensors, actuators and components for the optoelectronics industry, and components for use in microfluidic applications aimed at biomedical and other technologies.
The invention is also useful in the manufacture of an accelerometer. An accelerometer pattern is etched into the SOI wafer. Guidance for making an accelerometer is provided in U.S. Pat. No. 6,269,696, “Temperature compensated oscillating accelerometer with force multiplier”, issued Aug. 7, 2001 to Weinverg et al., incorporated herein by reference.
The details of one or more embodiments of the invention are set forth in the accompanying description above. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. Other features, objects, and advantages of the invention will be apparent from the description and from the claims. In the specification and the appended claims, the singular forms include plural referents unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. All patents and publications cited in this specification are incorporated by reference.
The following EXAMPLES are presented in order to more fully illustrate the preferred embodiments of the invention. These examples should in no way be construed as limiting the scope of the invention, as defined by the appended claims.
EXAMPLE
Fabrication Method for ALT BESOI Accelerometer
Summary. Several significant barriers to successful fabrication of the Silicon Oscillator Accelerometer using Silicon-On-Insulator (SOI) material have been encountered, necessitating the use of epitaxial material to build acceptable devices. Use of SOI rather than epitaxial material is strongly preferred for numerous reasons, including process flexibility, radiation hardness, performance, and IP issues. Here we show a method for an accelerometer device from SOI material. This process, coined the “ALT BESOI” process, appears to overcome current barriers to SOI processing.
Principal Advantages of SOI vs. Epitaxial Process. The driving force for using SOI material instead of epitaxial material to build the accelerometer is the greatly enhanced process flexibility afforded by the SOI process. For high performance, the best crystallographic quality is expected to produce the best devices. Device layers on SOI wafers can be of any doping level, type, crystallographic quality, etc. By contrast, epitaxial layers must be heavily-doped with boron. High doping concentrations of B are associated with etch pits, extended defects, curvature and strain, all undesirable features for strategic devices.
In addition to raw performance considerations, boost requirements require that the accelerometer be radiation hardened against fast neutrons, thermal neutrons and gamma radiation. Boron doping reduces hardness against thermal neutrons; therefore SOI material is preferred. More importantly, the glass substrate, whether PYREX® or Hoya SD-2, exhibits compaction under fast neutron and gamma irradiation [C. Allred, Master's Thesis, MIT Materials Science and Engineering Department , August 2000. Fabrication of an accelerometer built from SiGeB epitaxial material would be difficult to impossible with a silicon-on-silicon process, but would be very compatible with the use of SOI material for the device layer.
Process Difficulties with Baseline BESOI Process. Fabrication yields for the accelerometer were extremely low, partly due to the very large (>1 cm) die size, but also due to process problems with the baseline BESOI sequence.
Difficulties with this process are mainly associated with the final step in the process, in which the structural element is etched into the SOI device layer using the (Inductively Coupled Plasma) ICP etching process.
Etching of the structural element in epitaxial processes occurs prior to bonding to the glass substrate. Therefore, the ICP etch must penetrate below the line of the SiGeB etch stop layer, so that subsequent backside wafer dissolution results in full release. When the ICP process stops in a silicon wafer, a phenomenon known as RIE lag, shown in FIG. 8 , causes wide features to etch deeper than narrow features. However, this over-etch causes no serious harm, since wide features simply penetrates more deeply into the silicon wafer.
By contrast, when the ICP etch stops on a substrate such as the glass, wide features cannot etch any deeper, and therefore the plasma attacks the underside of released features and forms notches near the silicon—glass interface. This phenomenon in illustrated in FIG. 9 , where first SEM image shows what comb fingers should look like (epitaxial process), while the second SEM image shows comb fingers built using the standard BESOI process. Severe attack of the bottom of the comb fingers (comb is turned upside down for better visibility) is evident.
New ICP etch technology is specifically aimed at reducing notching and underside attack. However, the new technology is most effective when silicon is directly bonded to the non-etching substrate, such as glass or oxide. Alternatives attempted to date principally address the notching problem, and entail ICP etching down to the buried oxide layer prior to anodic bonding.
Process Difficulties with Initial Attempts at an Alternative SOI Process. High fidelity etching of the structural layer using an SOI wafer requires that the ICP process be conducted when the device layer is fully bonded to the oxide dielectric. The most obvious alternative SOI process therefore entails ICP etching prior to wafer bonding, followed by wafer thinning and oxide removal after the wafer bond.
Attempts to produce accelerometer devices using the sequence as modified above have not been successful. Basically, the oxide etch-stop mechanically fails during wafer thinning, resulting in attack of silicon underneath the etch-stop, and all devices are obliterated.
A re-design was performed, in which towers of silicon underneath the etch stop, but not connected to the device, could be inserted to insure mechanical survival during thinning. However, the most serious mechanical problem was the pressure differential between the internal cavities and the ambient. Since anodic bonding of the glass substrate is performed at 345° C., the pressure in the cavity at room temperature is, from the ideal gas law,
P=nRT/V, (1)
where n is the number of moles, R the universal gas constant, and V the volume, all fixed. Since anodic bonding is performed at atmospheric pressure, the internal cavity pressure at room temperature is P=(293 K/(273+345)K)˜0.45 atm. Therefore, at room ambient, the cavity will tend to implode, while in a vacuum chamber, the cavity will tend to burst.
Basic Description of New ALT BESOI Process. Herein is presented a new, alternative BESOI process, coined “Alt BESOI.” As the initial prototype alternative processes did, this new process differs from baseline BESOI in that ICP etching occurs prior to anodic bonding.
Four salient differences from initial prototype alternative BESOI processes are (1) ICP etch is conducted using newly available SOI etch technology, (2) A pressure relief hole is inserted in the glass to eliminate pressure differentials during wafer thinning, (3) Wafer thinning is accomplished using a dry plasma process rather than a wet etch, and (4) The die layout is adjusted to minimize the spacing between anchored features (without affecting the actual accelerometer design.)
Initially, a standard SOI wafer is provided, which is similar to that used in both the baseline and prototype alternative SOI processes. First, the SOI wafer is cleaned and patterned for the mesa etch. The mesa etch may be performed using KOH or other etchants. This represents yet another advantage of the SOI process over its predecessors.
Once the mesa etch has been performed, the wafer is cleaned and patterned for the structural etch. Since the process etches straight down to the dielectric layer, which is bonded everywhere to the device layer, technology designed to prevent plasma etching problems at the dielectric—device interface becomes very effective.
In one embodiment, the SOI wafer, which has been patterned and etched through both the mesa and structural layers, is then bonded to a glass substrate. The glass substrate fabrication steps are outlined in FIG. 3 . First, the glass wafer is cleaned and patterned for the electrode pattern. In this embodiment, the electrode pattern is composed of multilevel metallization. The glass wafer is then recess-etched, and, without removing the photoresist, a blanket sputter of the multilevel metallization is performed. Finally, the wafer undergoes “lift-off”, where metal not applied directly to the substrate is removed.
The advantage of access ports is evident, as the substrate wafer is bonded to the processed SOI wafer. These access ports may be etched, or more preferably, mechanically or ultrasonically drilled through the glass. The spacing of these holes is determined by the die size and by the presence and distribution of bonded seals between the SOI wafer and the substrate. Since the purpose of the access ports is to equalize the pressure between the internal cavities and outside of the wafer sandwich, at least one such port must be positioned within each region sealed by bonding. Typically, these regions coincide with the die size, so that each device is isolated from all others by a bonded structure known as a seal ring.
Once the SOI and glass wafers have been processed, they are anodically bonded. The remainder of the process sequence is illustrated in FIG. 4 . Note that the presence of the access port ensures that the inner cavities are at the same pressure as the external environment. Without this access port, the quantity of gas inside the cavity is fixed when the bond is formed.
Once the wafers have been bonded together, with the device side of the SOI wafer bonded to the metallized side of the glass, the handle layer of the SOI wafer must be removed. Without an access port, this material may be removed in a wet chemical etch or by a dry plasma etch. With the access port present, only the dry process may be used. For the present example, a RIE reactor may be used to remove the handle silicon layer. One required feature of RIE process tool is that it enables the plasma removal to occur with equalized pressure across the oxide dielectric. The other required feature is that plasma gases cannot gain access to the cavity through the port; otherwise, attack of structural layers would ensue.
The final step in the process is removal of the oxide dielectric. In this as well as previous embodiments, removal of the dielectric layer must be performed using a dry plasma etch process, so as not to attack the bulk glass and metallization on the topside of the device. Once the dielectric has been removed, the final structure is revealed. Excellent build quality is expected, based upon the use of the new ICP SOI etching technology and pressure equalization during thinning.
The foregoing description has been presented only for the purposes of illustration and is not intended to limit the invention to the precise form disclosed, but by the claims appended hereto.
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The invention provides a general fabrication method for producing MicroElectroMechanical Systems (MEMS) and related devices using Silicon-On-Insulator (SOI) wafer. The method includes providing an SOI wafer that has (i) a handle layer, (ii) a dielectric layer, and (iii) a device layer, wherein a mesa etch has been made on the device layer of the SOI wafer, providing a substrate, wherein a pattern has been etched onto the substrate, bonding the SOI wafer and the substrate together, removing the handle layer of the SOI wafer, removing the dielectric layer of the SOI wafer, then performing a structural etch on the device layer of the SOI wafer to define the device.
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FIELD OF THE INVENTION
[0001] This invention relates generally to emergency egress, and in particular, to a method of creating vertical acting emergency egress with simultaneous fire/smoke barrier protection.
BACKGROUND OF THE INVENTION
[0002] By code, buildings such as industrial, school and public buildings require fire and smoke barrier opening protectives. They also require emergency egress capability. Due to the simplistic operation and known designs of swing door exit hardware, side-hinged swinging doors are commonly used to simultaneously accomplish both.
[0003] However, code rated side-hinged swinging doors are not always the desired design choice to meet code requirements. For structures needing higher occupancy load egress and fire/smoke protection requirements, multiple swing doors and/or banks of swing doors and their associated frame assemblies are used. The framing requirements of multiple doors and/or banks of doors present architectural challenges for building designers.
[0004] In an attempt to overcome these challenges, a variety of door designs have been developed. One known design uses up to two swinging tire door and frame assemblies that store in pockets perpendicular to the opening. A second known design includes a bank of swinging fire door and frame assemblies that are attached to the bottom of a coiling door. Although these designs include commonly accepted side-hinge swinging doors, they require significantly more head or side room clearances and cost more to manufacture than earlier designs.
[0005] Another known design uses commonly accepted side-hinge swinging doors in an accordion folding fire door configuration. However, this design requires side stack space for the folded accordion door and non-folding side-hinge swinging door(s). Because occupancy load determines the amount of door opening/number of required doors, each required side-hinge swinging door mandates additional side stack space, thereby reducing the overall free space and presenting construction challenges.
[0006] Another known design uses accordion folding fire doors with an integral DC power supply and curtain mounted egress activation hardware that causes electric opening of the door for egress. The speed of clearing the opening must be coordinated with the building occupant load and required egress opening width within 10 seconds of egress hardware activation. These doors mandate ample side room to store the accordion folding fire door and operating system
[0007] Accordingly, there remains a continuing need for improved combined emergency egress and fire/smoke barrier designs. The present invention fulfills this need and further provides related advantages.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention presents a novel alternative to side-hinged swinging doors and offers access to a broad egress opening width needed to meet higher occupancy egress requirements while simultaneously qualifying as a fire/smoke barrier.
[0009] A single overhead coiling fire door is provided with an operator that will run the door under both normal condition and during a power failure or fire/smoke condition at an established average door speed, and also provide established levels of low battery warning signals/actions while also providing the ability to open as required for emergency egress. In a preferred embodiment, an overhead coiling fire door shaft assembly is counter-balanced to allow a fire door curtain to automatically close at a governed controlled descent upon reaching an established critical low battery condition.
[0010] Such configurations allow building designers the ability to reduce the construction costs and aesthetic problems associated with numerous banks of fire/emergency egress doors.
[0011] Another advantage is the ability to provide more open occupancy space.
[0012] Yet another advantage is the elimination of side-hinged swing door mullions and header construction, thereby allowing for unobstructed paths of egress.
[0013] When compared to pocket width requirements for horizontal sliding egress fire doors and head room requirements for rolling doors with attached side-hinged swinging doors, the present disclosure requires minimal head and side room clearances.
[0014] Still another advantage is that the doors can remain fully out of egress paths during normal conditions, thereby providing fewer tendencies with which to be tampered. Side-hinged swing doors can get blocked or wedged in the open position.
[0015] Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings are included to provide a further understanding of the present invention. These drawings are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the present invention, and together with the description, serve to explain the principles of the present invention.
[0017] FIG. 1 is an isometric view of the spring release mechanism depicting the governor and sprockets.
[0018] FIG. 2 is an isometric view of the spring release mechanism with the outer bracket, drop out pawl and swing arm stop.
[0019] FIG. 3 is an isometric view of the spring release mechanism of FIG. 2 further depicting the swing arm.
[0020] FIG. 4 is an isometric view of the spring release mechanism of FIG. 3 further depicting the adjusting wheel and pin.
[0021] FIG. 5 is a front view of the spring release mechanism with the pin engaged.
[0022] FIG. 6 is a front view of the spring release mechanism with the pin disengaged.
[0023] FIG. 7A is a front view of the spring release mechanism depicting the swing arm stop channel.
[0024] FIG. 7B is a side view of the spring release mechanism depicting the swing arm stop channel.
[0025] FIG. 8 is a front view of the spring release mechanism with the engaged pin and swing arm.
[0026] FIG. 9A is a front view of the spring release mechanism with the engaged pin, swing arm, and swing arm stop.
[0027] FIG. 9B is a side view of the spring release mechanism with the engaged pin, swing arm, and swing arm stop.
[0028] FIG. 10 is a front view of the spring release mechanism depicting the re-tensioning direction.
[0029] FIG. 11 is a front view of the spring release mechanism after re-tensioning.
[0030] Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] As required, detailed embodiments of the present invention are disclosed; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms. The figures are not necessary to scale, and some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. Where possible, like reference numerals have been used to refer to like parts in the several alternative embodiments of the present invention described herein.
[0032] In a preferred embodiment, an overhead coiling door upon receiving a first alarm signal enters a first alarm state, causing a door operator to close the overhead coiling door curtain under power within a pre-established time. If emergency egress is required, upon activation of an egress device, the operator causes the door curtain to open to a pre-established opening height, pause for a pre-established period of time to allow emergency egress and then reclose if still in the first alarm state. Once the alarm signal is cleared, causing the first alarm state to end, the door curtain is reset to the fully open position by user activation of an “open” control circuit.
[0033] The operator is, for example, a DC operator with a self-contained power cell (battery) to run the door under normal conditions and power failure. The door's power cell is continually charged while AC power is present and provides for standby power during an AC power failure. The operator is capable of running on AC power if the power cell is not present.
[0034] The door curtain may be reset to the fully open position by user activation of an “open” control circuit once the first alarm signal is cleared. Optionally, the door curtain may be set to automatically open to the fully open position after the first alarm state is cleared.
[0035] The above sequence utilizes power operation of the operator. Battery backup is provided to power the operator during electrical grid power failure. However, to meet established safety requirements, emergency egress must also be available during a battery underpowered or non-powered state.
[0036] The operator provides varying levels of low battery warning signals and actions.
[0037] In a non-alarm state, during an initial Level 1 low battery condition, a warning, for example, an audible warning and/or a warning output signal at a terminal strip connection is generated. The audible signal is designed to be heard outside the operator enclosure. During a Level 1 battery condition the operator is capable of full functionality. The audible warning signal and warning output signal allow for corrective intervention prior to an alarm condition.
[0038] If corrective intervention is not taken, and battery power continues to decrease, at a pre-established low battery power rating, a Level 2 low battery condition is entered, whereupon the operator power operates to position the door curtain to a pre-established egress opening height, for example, to a 96″ opening height, while the audible warning and/or terminal strip output signals continue. An alarm signal state during a Level 2 battery condition will cause the door to power close.
[0039] During a Level 2 low battery condition, adequate battery power remains for the operator to power open the door to the pre-established egress height upon an egress device or “open” button activation and pause for a pre-established time sufficient to allow emergency egress, before the operator powers the door to re-close.
[0040] If battery power continues to degrade, at a pre-established minimum battery level, a Level 3 battery condition is entered. During a Level 3 battery condition, sufficient battery power remains for the operator to power operate the door to a pre-established egress opening height, for example, to a 96″ opening height and then release the operator clutch/motor drive. A counter balance, for example, a spring counter-balance, is set such that the door will stay at the egress opening height.
[0041] When the battery recharges to a normal level of operation, that is above that of a Level 1 condition, the operator reengages the clutch/motor drive and returns to normal operation.
[0042] Because the door will not be able to be power operated during a. Level 3 battery condition, the battery should be properly maintained to prevent entering a Level 3 battery condition. The audible warning and warning output signal are used to aid in proper battery maintenance.
[0043] As discussed above, powered emergency egress operation is activated from either side of the door opening by, for example, a wall mounted push button station or by a hands free method of activation. Egress device activation will initiate power opening of the door during normal, Level 1 and Level 2 conditions. An obstruction sensing edge device is used to react to doorway obstructions during power closing of the door to prevent damage to the door or objects or injury to incapacitated persons lying beneath the door curtain.
[0044] For example, full length light curtains can be used to act as both the egress activation control and as opening obstruction sensors. Consecutive breaks of the light curtains can be programmed to reset a door closing tinier to its pre-established time delay, thereby allowing for multiple individuals to exit before the door begins to re-close.
[0045] The sequences described above allow for fire/smoke barrier operation during normal, Level 1 and Level 2 battery conditions. Powered emergency egress has been described for normal, Level 1, and Level 2 battery conditions.
[0046] Powered emergency egress is not appropriate for a Level 3 battery condition. During a Level 3 battery condition, emergency egress is obtained by monitoring the battery condition and programmatically positioning the door to an egress opening height. If battery warning signals are ignored and the operating system reaches a Level 3 battery condition, the operating system will power the door to a pre-established egress opening height, for example, to a 96″ opening height to provide egress and release the clutch/motor drive to provide egress. The door is counter-balanced to remain open.
[0047] In order to provide fire protection at the opening during a Level 3 battery condition a high temperature limit trip sensor, for example, to trip at a temperature not conducive to human life, for example, from about 165° F. to about 500° F., will when tripped prevent power operation and release spring tension. Once tripped by a high temperature sensor at the opening, an open door will gravity close to provide fire protection. The fire door system will require manual resetting once the high temperature sensor trips. A fire rated enclosure protects the operator up to the high temperature limit.
[0048] A closing speed governor is fabricated into the door or operator and is functionally independent of the operator drive clutch release.
[0049] Turning now to the figures, a novel spring release mechanism for releasing the clutch/motor drive during a Level 3 condition is presented. An advantage of this novel clutch/motor drive is its ability to allow for only limited spring tension release, the remaining tension reduced enough to allow the door curtain to gravity close.
[0050] FIG. 1 depicts the spring release mechanism 2 which comprises a large sprocket 4 rotationally fixed to a shaft 18 arising from inner bracket 6 . A governor 8 , for example, a viscous governor, comprises a small sprocket 10 rotationally fixed to the governor 8 , but free to rotate on stud 12 . The viscous governor 8 , is operatively engaged by first ratcheting pawl 14 which is attached to inner bracket 6 . Large sprocket 4 and small sprocket 10 are operatively engaged, for example, by chain 16 . The viscous governor is used to limit spring release speed.
[0051] FIGS. 2-4 depict an outer bracket 20 which is attached to inner bracket 6 and comprises a dropout pawl 22 and a swing arm stop 24 . Shaft 18 extends through outer bracket orifice 25 to rotationally receive swing arm 26 . Swing arm 26 is rotationally restricted by engagement with dropout pawl 22 . An adjusting wheel 30 rotatively engages shaft 18 and comprises multiple receptacles 32 for receiving pin 34 and a tensioning tool (not shown) used to tension the counter balance spring (not shown).
[0052] Turning now to FIGS. 5-11 , in use, the release operates as follows. The tension of the counter balance spring is set as required by inserting the tensioning tool (not shown) into receptacles 32 and rotating the adjusting wheel in known fashion to tension the spring (not shown). The tensioned spring is maintained in a tensioned. position by lifting the dropout pawl 22 to engage the pin 34 which has been inserted into a receptacle 32 on the rotationally forward side of swing arm 26 . Rotation direction is designated by arrow A, FIG. 6 .
[0053] The dropout pawl 22 is maintained in an engaged position by, for example, a sash chain connected to a fusible link (not shown). Upon activation of the fusible link, for example, upon reaching a predetermined high heat ambient temperature, the dropout pawl 22 will drop from the engaged position, releasing the pin 34 . Spring tension causes the adjusting wheel 30 to move freely in the direction shown by arrow A. The governor 8 will act to moderate the rotational velocity of the assembly, and by operative connection, the door curtain, thereby preventing excessive door curtain closing spend and permanent damage.
[0054] As depicted in FIGS. 7A and 7B , when adjusting wheel 30 rotates, the pin 34 will pass through the channel 35 of the swing arm stop 24 and engages swing arm 26 just prior to attaining one complete rotation of adjusting wheel 30 . As the spring tension continues to turn adjusting wheel 30 , the engaged swing arm 26 rotates until it is stopped by engagement with the swing arm stop 24 , effectively stopping further release of the spring tension ( FIGS. 9A and 9B ). In this fashion, the adjusting wheel 30 rotates beyond one full revolution before being stopped, thereby allowing sufficient spring tension release to allow the door curtain to gravity close, yet not allow release of all spring tension.
[0055] FIGS. 10 and 11 depict the spring release mechanism re-tensioned by rotating the adjusting wheel 30 in the reverse direction, indicated by arrow B, until the swing arm 26 engages the opposite side of the swim arm stop 24 . The dropout pawl 22 is then lifted. to re-engage the pin 34 , thereby once again preventing adjusting wheel 30 from rotating, and thereby preventing the door curtain (not shown) from gravity induced free fall.
[0056] The ratcheting feature of the governor 8 , using ratcheting pawl 14 allows the governor 8 to engage the ratcheting pawl 14 when the spring tension is being released, thus not impeding the installation process. This ratcheting feature also acts as a safety feature to engage the governor 8 if the installer were to lose their grip while adding turns to the adjusting wheel 30 , thereby preventing component damage and decreasing the risk of injury.
[0057] Although the present invention has been described in connection with specific examples and embodiments, those skilled in the art will recognize that the present invention is capable of other variations and modifications within its scope. These examples and embodiments are intended as typical of, rather than in any way limiting on, the scope of the present invention as presented in the appended claims.
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The present invention presents a novel alternative to side-hinged swinging doors that offers access to a broad egress opening width needed to meet higher occupancy egress requirements while simultaneously qualifying as a lire/smoke harrier. In a preferred embodiment, a single overhead coiling fire door shaft assembly is counter-balanced to allow a fire door curtain to automatically close at a governed controlled descent upon reaching an established critical low battery condition. An operator is provided that will run the door under both normal condition and during a power failure or fire/smoke condition at an established average door speed, and also provide established levels of low battery warning signals/actions while also providing the ability to open as required for emergency egress until the temperature at the opening is not conducive for human life.
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BACKGROUND OF THE INVENTION
The invention relates to an apparatus for electrolytic surface coating of pourable material, preferably for electrodeposition of metal, in particular aluminum, from an electrolyte. The pourable material is transported in the cathodic track of a vibrator conveyor at least partly in the treatment bath of the electrolyte.
It is known that by surface improvement of metal parts their life can be lengthened and new areas of use can be opened up. For example, the coating of light metal and ferrous materials may be appropriate, as they generally involve relatively base metals, the surfaces of which may corrode under atmospheric action. Suitable pretreatment gives the parts a polished surface without cover layer. The metallic coating may be supplemented with an aftertreatment.
During the electrodeposition the pourable small parts must be held together so that each individual part has electric contact. On the other hand, the bulk material to be treated should be spread out to the extent that the metal deposition can occur on a product surface as large as possible and a current density as uniform as possible is ensured on all parts. Another essential prerequisite for satisfactory metal coatings with a uniform layer thickness is sufficient mixing of the material during the electrodeposition. The apparatus for electrolytic surface coating is equipped with conveying means for the transport of the bulk material through the electrolyte, which in conjunction with corresponding inlet and outlet locks permit either continuous or intermittent feeding and removal of the material. In addition, the movement through the electrolyte and the thorough mixing of the material as well as the transport through the electrolyte must be carried out in such a way that gentle treatment of the material is ensured and even delicate parts are not mechanically damaged during the electrodeposition.
For mass electrodeposition, in particular for electrodeposition of aluminum, a known apparatus is suitable in which a vibrator conveyor with a horizontal and a vertical vibration component is provided for the transport of the pourable material through the treatment bath. This vibrator conveyor transports the pourable material, utilizing the forces of gravity, in a spiral conveying trough in ascending direction around a central pipe connected with the conveying trough. The vibrator conveyor is accommodated with the central pipe in a gasproof vessel which contains an electrolyte into which the vibrator conveyor dips partially. As drive means are used for example oblique-action vibrators or obliquely set rods. Such vibrator conveyers require relatively little drive force and make possible a gentle conveyance of the pourable material. One obtains intensive product movement and good electrolyte exchange as well as uniform current consumption over the entire effective surface of the spread-out material (EP-A0 209 015).
In a known apparatus for the plating of parts by immersion and movement in a plating solution, these parts execute a vibrational movement and at the same time a circular movement. The parts are present with the plating solution in a vessel. The movement path of the parts leads from a lower entry zone spirally upward to an exit zone. For moving the parts, the entire vessel containing the plating solution is made to vibrate (FR-A 2 103 611).
Since during the coating the material of the anodes is eroded and deposited on the bulk material, the anodes must, as is known, be replaced after a predetermined number of hours of operation. Further it is desired to obtain a high material utilization of the anodes, and in addition the availability of the installation is to be maintained by reduction of the down times for changing the anodes.
For the electrolytic surface coating of pourable material, in particular for the electrodeposition of aluminum in a vibrator conveyor system, the anodes may be disposed, accessible from the outside, on the inner wall of the vessel or on a so-called anode shaft cover. As the anodes are used up by the coating process, their life is limited to a predetermined number of hours of operation. For this reason they are replaced when about 50 to 70% of their material has been used up. This is necessary because otherwise the anodes may corrode through if the erosion is irregular and the remaining stumps may warp due to their dead weight and may thus establish a shortcircuit to the cathode. For changing the anodes, the installation filled with electrolyte at about 100° C. must be cooled, emptied, flushed with toluene, and dried. The electric leads of the anodes are disconnected, the anodes exchanged through openings in the vessel wall, and for restarting the apparatus these operations occur in reverse order.
SUMMARY OF THE INVENTION
It is the object of the invention to indicate an apparatus for electrolytic surface coating of bulk material with a vibrator conveyor system which is of especially simple design and makes simple changing of the anodes possible. In particular the life of the anode is to be lengthened considerably.
According to the invention, this problem is solved with the characterizing feature of claim 1. In this form of realization of the apparatus for surface coating it is possible, after a predetermined number of hours of operation, to remove residual anode material from the installation in a simple manner and to supply new anode material as a granulate.
The cathode and anode tracks are appropriately secured on joint supporting stringpieces which serve at the same time as power lead for the cathode. These supporting stringpieces are then appropriately connected with the central pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
For further elucidation of the invention reference is made to the drawing, in which an apparatus for electrodeposition of aluminum is illustrated schematically as a practical example.
FIG. 1 shows a transverse section through the installation, and
in FIG. 2 the design of the electrodes and their electrical contacting is illustrated.
FIG. 3 depicts a further embodiment of the invention wherein the cathodic track is electroconductively connected to the contact bar via screws and contact pins.
FIG. 4 depicts yet a further embodiment of the invention and illustrates a power lead.
DETAILED DESCRIPTION OF THE INVENTION
In the apparatus according to FIG. 1 for electrolytic surface coating of pourable material, preferably for the electrodeposition of metal, in particular aluminum, from an aprotic, oxygen- and water-free aluminum-organic electrolyte, a vibrator conveyor is provided for the transport of pourable material to be coated. The vibrator conveyor comprises a central pipe 2 with a bottom 3, a cover 4, and a sidewall 5. The central pipe 2 protrudes from a vessel 6, the cover 7 of which in the form of an annular disk is fastened on the sidewall 5 of the central pipe 2 through a flexible connection 8. The sidewall 5 of the vessel 6 is connected with the bottom. The bottom 3 of the central pipe 2 rests, able to vibrate, on springs 9 and on a gas cushion 10, which is enclosed in the manner of a diving bell between the bottom 3 of the central pipe 2 and an annular-cylindrical extension 11 of the central pipe 2, as well as an electrolyte 12, by which also the central pipe 2 is partially surrounded. Above the electrolyte 12 a gas chamber 14 is formed, which may be filled preferably with nitrogen. The central pipe 2 is provided with an oscillatory drive 16, which is disposed on a bearing block 17 above the cover 4 of the central pipe 2.
In conjunction with a mechanism not shown in the figure, the drive 16 produces an oscillating movement of the central pipe 2 and hence of a conveying trough containing the bulk material 20, which trough forms a cathodic track 22, arranged spirally around the central pipe 2 and connected with it. The conveying trough 21 is provided with supporting stringpieces 24 to 31, disposed at predetermined intervals around the central pipe 2. The supporting stringpieces 24 to 29 serve both as mechanical mount and as power lead for the cathodic track 22 and hence also of the bulk material 20. Two additional supporting stringpieces 30 and 31, present above the electrolyte 12, serve only to fasten the cathodic track 22. Each of the superposed stringpieces 24 to 26 and 27 to 29 is electroconductively connected by means of a contact bar 32, 33 to an electrode terminal 34, 35. For supplying the bulk material there is provided a feed lock 38, and for the removal of the bulk material, a discharge lock 39.
Between the spirals of the conveying trough a granulate anode 40 is provided, which consists of a granulate of the material that is intended for the coating of the bulk material and is transported through the oscillating movement of the central pipe 2 of a perforated anodic track 42 consisting of an electrically insulating material. As power lead for the granulate anode 40 contact pins 46 to 49 are provided. The superposed contact pins 46 and 47 are connected via a contact bar 52 and a flexible connecting conductor 54 to an electrode terminal 56, which is connected to a voltage source not shown in the figure. In like manner the contact pins 48 and 49 are connected via a contact bar 53 and a flexible connecting conductor 55 to an electrode terminal 57, which too is connected to a supply voltage not shown in the figure. In this form of realization of the apparatus, consumed anode material can be replaced continuously by new granulate during the deposition. For this purpose a lock not shown in the figure is provided for supplying the anode material and possibly also for its removal. These locks may be offset 90° for example relative to the locks 38 and 39 for the bulk material 20.
In the form of realization according to FIG. 2, only a part of FIG. 1 with the supporting stringpiece 25 is shown, which is fastened on the central pipe 2 and connected electroconductively with the contact bar 32. The cathode track 21, containing the bulk material 20, is screwed to the supporting stringpiece 21. For this purpose screws 61 are used which consist of electrically conducting material and which may in particular be provided with enlarged heads. These screws, for example six for each of the stringpieces, of which only three are indicated in the figure for simplification, serve both for the mechanical attachment of the cathode track 22 on the stringpiece 25 and for current transmission from the contact bar 32 to the cathode track 22. The stringpiece 25 is electrically insulated against the central pipe 2. The stringpiece 25 comprises a metallic contact pin 65, surrounded by a sheath 66, which may consist of electrically insulating material, preferably laminated cloth. The screws 61 form an electric connection between the bulk material 20 and the contact pin 65, which is electroconductively connected with the contact bar 32. The granulate anode 40 is connected via a screw union with screws 64, which can serve both for the attachment and for the electric contacting of the granulate anode 40, to the electrically insulating contact pin 46, which is connected to the contact bar 52. The electrical and chemical insulation of the contact bar 52 and of the contact pin 46 is not shown in the figure for simplification.
In a further form of realization according to FIG. 3, the cathodic track 22 containing the bulk material 20 is electroconductively connected to the contact bar 12 via screws 61 to 63 as well as contact pins 67 to 69. For the anode granulate contained in the anodic track 42, however, a separate power lead 70 is provided, consisting of the anode granulate 40. This power lead 70 consists of an insulated down pipe 72, which is filled with the anode granulatee 40. Protruding into this anode granulate 40 is an electric conductor 74 which is passed through the down pipe 72 and is connected to the anode terminal 56 via the flexible connecting conductor 54. Admission of the granulate 40 to the power lead 70 occurs through an opening, not specifically marked, in the cover 7 of vessel 6. Above the cover 7 a lock 78 is provided, which may be constructed in known manner and is indicated only in dash-dot lines in the figure.
The granulate anode is moved with the vibration of the central pipe 2 in the anode track 42 preferably in a closed loop. For this purpose the anode track may be provided for example with a return device not shown in the drawing, which may consist for example of a valve controllable from the outside, by means of which the anode granulate 40 falls from an upper part of the anode track 42 back onto a lower part. In similar manner also the bulk material 20 can be conducted in a closed loop until a sufficient coating has been obtained.
In the form of realization according to FIG. 4, besides the power lead 70 with the down pipe 72 and the conductor 74 there is associated with the anodic column an additional power lead 71. In this poer lead 71, too, an anodic column is formed by the granulate, which column is contacted by a conductor 75 protruding into the anodic column in the upper part of the down pipe 73.
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The bulk material is transportable in an electrolyte in the conveying trough of a vibrator conveyor. The conveying trough forms a cathodic track for the bulk material. According to the invention, a granulate anode (40) is provided which consists of a granulate of the material provided for deposition, which is transportable with the vibration in an anodic track (44) associated with the cathodic track (22). This form of realization of the apparatus with a large-surface anode of movable granulate results in a simple design solution for supplying and for replacing the anodes and in a better material utilization of the anode. In addition, the necessary down times are reduced.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a bulletproof woven fabric capable of preferably being used as a so-called bulletproof jacket for protecting a body or the like against a bullet or the like discharged from a gun, and further to a method of weaving the same as well as a warping apparatus and an opening apparatus therefor.
Further the invention relates to a woven fabric preferable as a bulletproof woven fabric or the like for protecting a body or the like against, for example, a bullet discharged from a gun.
2. Description of the Related Art
A multifilament yarn constituted by bundling two or more filaments has excellent orientation of fibers and high density, and therefore the tensile strength and elongation are superior to those of a spun yarn. Accordingly, the multifilament yarn is preferable for use of a bulletproof woven fabric. According to such a multifilament yarn, filaments constituting the multifilament yarn are liable to cut by being brought into frictional contact with a guide member for determining a yarn passage or being brought into frictional contact with a reed or the like in a weaving process and a weaving preparatory process prior thereto. Even when a single filament is cut, the yarn is fluffed and the operation has to be stopped.
In order to resolve the problem and prevent the collectness of filaments from deteriorating and prevent the yarn from separating into individual filaments, a filament textured yarn produced by pertinently twisting the yarn or injecting highly compressed air from the transverse direction to a yarn bundle in running it thereby entangling the filaments.
According to the slightly twisted multifilament yarn and textured filament yarn, the orientation of fibers is lowered and accordingly, mechanical properties required of a bulletproof woven fabric are deteriorated.
Further, it is important for enhancing bulletproof ability that not only the mechanical properties of the warp and the weft are excellent but the yarn is not molten by a bullet or debris thereof at high temperatures and the mechanical properties are maintained.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a bulletproof woven fabric having excellent bulletproof ability.
It is another object of the invention to provide a method of weaving a bulletproof woven fabric and provide a warping apparatus and an opening apparatus used for weaving the bulletproof woven fabric.
It is still another object of the invention to provide a woven fabric suitable for a bulletproof fabric or the like having improved mechanical properties and thermal properties.
The invention provides a bulletproof woven fabric comprising:
non-twisted multifilament yarns opened by arranging filaments such that a cross-sectional shape thereof is flattened as a whole, the non-twisted multifilament yarns being used as warps and wefts,
wherein weaving is performed while keeping fiber axes of the filaments substantially linear.
According to the invention, a plurality of filament yarns constituting the multifilament yarn are arranged and opened such that the cross-sectional shape of the multifilament yarn is flattened as a whole where the multifilament yarn is not twisted, that is, non-twisted and not worked. Therefore, the multifilament yarn used in the invention has excellent orientation of fibers, high density and accordingly excellent mechanical properties for enhancing bulletproof ability, for example, sufficiently large values in tensile strength and initial tensile modulus. Further, the multifilament yarns are non-twisted and no work of entanglement or the like is performed thereon, and therefore no crimp is caused. Accordingly, the shock wave caused in impacting a bullet discharged from a gun to the woven fabric, propagates smoothly in the filaments, the kinetic energy of the bullet is dispersed in the woven fabric in a wide range and the kinetic energy of the bullet is dissipated by being efficiently converted into breakage of the filament.
According to the invention, the fiber axes of filaments are kept substantially linear and there is no twist or crimp as described above and therefore, the bulletproof ability is enhanced as mentioned above.
According to the invention, the fabric is woven while keeping the fiber axes of filaments constituting the multifilament yarns substantially linear, and therefore the mechanical properties of the multifilament yarns can effectively be utilized, that is, the fabric can be used without lowering the tensile strength and the initial tensile modulus by which the kinetic energy of the bullet discharged from the gun can be propagated and dispersed in a wide range and by which the kinetic energy of the bullet can be converted into energy for breaking fibers or the like in a short period of time such that a body is not injured. Thus, the bulletproof ability of the bullet proof woven fabric of the invention is enhanced. According to the bulletproof woven fabric of the invention, the bulletproof ability that is uniform in all the directions in the face of the woven fabric can be provided.
Further, according to the invention, compared with multifilament yarns having a sectional face in, for example, a substantially circular shape, gaps at crossing points of warps and wefts can be reduced by which the bulletproof ability can also be enhanced.
Further, according to the invention, the cross-sectional shape of the multifilament yarn is flattened as a whole by the opening operation and therefore, gaps at crossing points of warps and wefts are reduced by which the bulletproof ability can also be enhanced.
Further, according to the invention, the multifilament yarns are difficult to loosen after weaving the fabric, the original shape is maintained and therefore, even if the fabric is used in a state of mounting to a human body, there is no concern of lowering the bulletproof ability.
Further, according to the invention, by using the opened multifilament yarns as warps and wefts, the gaps are reduced as mentioned above, after weaving, the respective multifilament yarns are difficult to loosen, the original weaving texture can be maintained and the shape of the bulletproof woven fabric when it is actually worn as, for example, a bulletproof jacket, is difficult to deform unintentionally.
Further, in the invention it is preferable that the bulletproof woven fabric is one of a plain weave, a twill weave and a satin weave.
According to the invention, the invention comprises one of a plain weave, a twill weave and a satin weave and further, textures produced by deforming these whereby the woven shape is difficult to deteriorate.
Still further in the invention it is preferable that the multifilament yarn is of 50 through 1600 deniers and each of a plurality of filaments constituting the multifilament yarn is of less than 10 deniers.
According to the invention, filaments of 1 through 10 deniers may be bundled to constitute a multifilament yarn of 50 through 1600 deniers. For example, a multifilament yarn of 200 deniers may be constituted by 195 filaments. Filaments constituting the multifilament yarn have the same dimensions and shape.
By constituting the multifilament yarn by filaments of about 25 or more, 100 or more and further, about 200 or more as mentioned above, the density can be increased and a uniform yarn can be constituted whereby the bulletproof ability can be enhanced.
According to the invention, by using the multifilament yarn of 50 through 1600 deniers comprising filaments having counts of less than 10 deniers, the yarn is opened to improve the orientation of fibers as mentioned above and the density can be increased by which the tensile strength and the initial tensile modulus can be enhanced.
Further, the invention provides a method of weaving a bulletproof woven fabric in which a water jet loom is used, the method comprising:
in respect of warp, opening a multifilament yarn;
sizing the opened multifilament yarn;
thereafter, drying the sized multifilament yarn; and
looming the dried multifilament yarn to the water jet loom, and
in respect of weft, flowing a multifilament yarn by a water jet stream without opening and sizing to weft-insert at the water jet loom.
According to the invention, in respect of the weft, the multifilament yarn is opened, that is, the multifilament yarn is brought into a state where filaments are arranged without overlapping each other in the up and down direction or partially overlapping each other in the up and down direction such that the sectional shape thereof is flattened as a whole, sized and thereafter, dried and woven by being loomed to the water jet loom. By contrast, in respect of the weft, the multifilament yarn is flown by a water jet stream at the water jet loom, put into the weft inserting motion through a shed formed by dividing the warps loomed on the loom in the up and down direction. In this way, the fabric is woven by the shedding motion by the heald, the weft inserting motion of the weft by the water jet stream and the beating-up motion by the reed.
According to the weaving method, in respect of the warp, the multifilament yarn sized in the opened state is dried and loomed to the water jet loom and the weft is flown by the water jet stream and put into the weft inserting motion without being opened or sized and therefore, the weft can easily be opened pertinently by water.
Further, in the invention it is preferable that in the sizing operation is used a size including polyvinyl alcohol or an acrylic group size material.
According to the invention, for example, polyvinyl alcohol or an acrylic group size material, for example, acrylic acid ester or the like is used as the size and accordingly, degumming operation such as desizing can easily be performed after weaving the fabric. The size does not contribute to enhancing the bulletproof ability and the desizing operation is useful in reducing weight when the bulletproof woven fabric is used as a clothing such as a bulletproof jacket.
According to the invention, polyvinyl alcohol or an acrylic group size material is used for the size by which the state of opening the multifilament yarn is maintained and further, the drying operation is facilitated.
Further, in the invention it is preferable that desizing is performed after weaving the fabric.
According to the invention, the weft is the multifilament yarn which is not subjected to the operation of twisting and crimping or the like and further, is not subjected to the opening operation and the sizing operation and is led to the shed along with water from a nozzle. The water can prevent the respective filaments from being disintegrated apart by enlarging intervals therebetween and bring the weft into the opened state having a density substantially the same as that of the warp. The weft can be brought into the opened state in this way by adjusting the flow rate and the speed of the water jet and a time period of injecting water in synchronism with the operation of putting the weft into the weft inserting motion through the shed and the like. Water is adhered to the entire length of the weft inserted into the shed.
According to the invention, weight reduction can be achieved by removing the size which does not effect influence on the bulletproof ability through desizing operation using such a size, which is important when such a particularly woven fabric is used as material of, for example, a bulletproof jacket or the like.
Further, in the invention it is preferable that the weft is brought into the opened state by adjusting the water jet stream during flying of the weft.
In respect of the weft, intervals among the filaments are enlarged in flying the weft in the weft inserting motion and after flying the weft, the weft is pinched by upper and lower crossing warps by which the cross-sectional shape of the weft is flattened. In this way, the fabric is woven under a state where the weft is opened.
According to the invention, by adjusting the water jet stream in the water jet loom for opening the weft, that is, by adjusting the flow rate and the speed or the like of water, the weft can automatically be opened by arranging filaments of the weft in the direction of fiber axes of warps in flying the weft. Thereby, the constitution can significantly be simplified.
According to the concept of the invention, not only the water jet loom but a shuttleless loom such as an air jet loom, a Rapier loom, a gripper shuttle loom represented by Sulzer or the like may be used.
Further, the invention provides a warping apparatus comprising:
(a) a creel for supporting a plurality of bobbins each wound with a non-twisted multifilament yarn;
(b) tension applying means for applying a tension to the multifilament yarn drawn from the bobbin;
(c) an opening apparatus for arranging filaments such that a cross-sectional face of the multifilament yarn from the tension applying means is flattened as a whole;
(d) a sizing apparatus arranged on the downstream side of the opening apparatus, for sizing the multifilament yarn from the opening apparatus;
(e) a drying apparatus arranged on the downstream side of the sizing apparatus, for drying a size adhered to the multifilament yarn; and
(f) winding means for winding the multifilament yarn dried by the drying apparatus while applying a tension to the multifilament yarn.
Further, the invention provides a warping apparatus comprising:
(a) a creel for supporting a plurality of bobbins each wound with a multifilament yarn;
(b) tension applying means for applying a tension to the multifilament yarn drawn from the bobbin;
(c) an opening apparatus:
wherein first, second and third guide rollers are arranged in the direction of running the multifilament yarn from the tension applying means;
wherein the first, second and third guide rollers each have an outer diameter uniform in an axial direction and a rotational axis line orthogonal to the running direction;
wherein the axis line of the second guide roller is arranged shifted to one side in respect of one plane including the axis lines of the first and third guide rollers;
wherein the multifilament yarn is made to wrap on the first guide roller on other side in respect of the one plane; and
wherein the multifilament yarn is made to wrap on an outer peripheral face of the third guide roller on the one side in respect of the one plane and remote from the one plane,
the opening apparatus further comprising:
driving means for driving respectively the first, second and third guide rollers such that peripheral speeds V1, V2 and V3 of the first, second and third guide rollers establish the following relationship
V1>V2>V3
(d) a sizing apparatus arranged on the downstream side of the opening apparatus, including:
a size box for storing a size; and
a sizing roller a lower portion of which is partially dipped in the size, the sizing roller having a horizontal rotational axis line;
wherein the multifilament yarn from the opening apparatus is run in contact with an upper portion of the sizing roller;
(e) a drying apparatus arranged on the downstream side of the sizing apparatus, for drying the size adhered to the multifilament yarn; and
(f) winding means for winding the multifilament yarn dried by the drying apparatus while applying a tension to the multifilament yarn.
According to the invention, the multifilament yarns from a plurality of bobbins supported by the creel, are applied with a tension between the tension applying means and the winding means. Filaments constituting each of the multifilament yarns, are arranged contiguously one by one on the outer peripheral faces of particularly the second and third guide rollers in the opening apparatus installed between the tension applying means and the winding means. In this way, each of the multifilament yarns is opened such that the cross-sectional shape thereof is flattened as a whole and led to the sizing apparatus under this state and brought into contact with the upper peripheral face of the sizing roller, the multifilament yarns are adhered with the size and thereafter, the size is dried by the drying apparatus. The multifilament yarns which have been dried in this way, are wound to a beam, a drum or the like by the winding means.
In the conventional art, a multifilament yarn that is a grey yarn is subjected to a twisting operation, entangling or the like, wound once to a bobbin, a drum, a beam or the like. Thereafter, in order to perform a sizing operation, the multifilament fabricated yarn that is wound, is drawn, run and sized and is again wound to a bobbin, a drum, a beam or the like. Accordingly, in the conventional art, enormous labor and time are needed and the productivity is poor. According to the invention, multifilament yarn is opened and thereafter, sized at once and wound, with the result that the productivity is excellent.
According to another concept of the invention, a single multifilament yarn may be wound to a single bobbin and the single multifilament yarn may be wound after opening and sizing operation.
According to the warping apparatus, the multifilament yarn applied with a tension between the tension applying means and the winding means, can be opened by the opening apparatus and thereafter, sized by the sizing apparatus and further, dried by the drying apparatus after the sizing operation and in this way, the warp can be subjected to the warping operation while maintaining the automatically opened shape.
Further, in the invention it is preferable that a guide member for guiding the multifilament yarn from the bobbin is provided in the range of a yarn layer of multifilaments wound around while being shifted in a direction orthogonal to the axis line of the bobbin supported by the creel and further, along the axis line direction of the bobbin.
In the creel, the guide member for guiding the multifilament yarn in the direction orthogonal to the axis line of the bobbin is installed and the guide member is arranged in a range of a layer of the multifilament yarn wound to the bobbin along the axis line direction of the bobbin by which when the multifilament yarn is drawn from the bobbin, the multifilament yarn can be prevented from being twisted. The guide member may be a plate having a guide hole for inserting the multifilament yarn or may be other constitution, for example, mekubari or the like. The guide member can smoothly draw the multifilament yarn by being arranged at a central position of the layer of the multifilament yarn wound around the bobbin in respect of the axis line direction of the bobbin. The bobbin is rotatably installed to the creel.
According to another concept of the invention, the guide member may be arranged in the axis line direction of the bobbin spaced apart therefrom by an interval and the filament yarn may be drawn without rotating the bobbin. According to such a constitution, although the multifilament yarn is slightly twisted, the constitution does not effect significant adverse influence on the opening operation.
According to the invention, the guide member is arranged by being shifted in a direction orthogonal to the axis line of the bobbin and the guide member does not have a constitution where the guide member is installed in the axis line direction of the bobbin and therefore, the multifilament yarn drawn from the bobbin is prevented from being twisted by which the opening operation can be performed firmly.
Further, the invention provides an opening apparatus comprising:
first, second and third guide rollers,
the first, second and third guide rollers being arranged in a running direction of a multifilament yarn;
the first, second and third guide rollers each having an outer diameter uniform in an axis line direction and a rotational axis line orthogonal to the running direction;
wherein the axis line of the second guide roller is arranged shifted on one side in respect of a plane including the axis lines of the first and third guide rollers,
wherein the multifilament yarn is made to wrap on the first guide roller on other side in respect of the plane;
wherein the multifilament yarn is made to wrap on an outer peripheral face of the third guide roller on the one side in respect of the one plane and remote from the one plane;
wherein the multifilament yarn is made to wrap on the third guide roller on the other side in respect of the one plane, the opening apparatus further comprising:
driving means for respectively driving the first, second and third guide rollers such that peripheral speeds V1, V2 and V3 of the first, second and third guide rollers establish the following relationship
V1>V2>V3; and
tension applying means for applying a tension to the filament yarn, installed on the upstream side of the first guide roller in the running direction and on the downstream side of the third guide roller in the running direction.
According to the invention, the multifilament yarn applied with the tension between the upstream side and the downstream side of the first and third guide rollers, is run by being guided by being made to wrap partially on the outer peripheral face of the first guide roller, that is, over an angle less than 360°, made to wrap on the outer peripheral face of the second guide roller and thereafter, made to wrap on the outer peripheral face of the third guide roller. The first, second and third guide rollers each have the outer diameter uniform in the axis line direction, that is, a shape of a right circular column or the shape of a right cylinder and has the rotational axis line orthogonal to the running direction of the multifilament yarn. For example, the axis lines of the first and third guide rollers may be disposed substantially in one plane and the axis line of the third guide roller may be in parallel with the one plane. What is particularly important is that the peripheral speeds V1, V2 and V3 of the first, the second and third guide rollers are set smaller successively in this order and accordingly, the tension operating on the multifilament yarn is successively changed among the first, second and third guide rollers. Thereby, the multifilament yarn is opened such that respective filaments are displaced contiguously to each other in a direction orthogonal to the fiber axes of the respective filaments and the respective filaments do not overlap each other in the up and down direction.
According to the opening apparatus, by changing the tension of the multifilament yarn among the first, second and third guide rollers, the multifilament yarn can be opened by parallelly placing filaments by making uniform intervals among the filaments.
In the invention it is preferable that the first, second and third guide rollers each are provided with a fluororesin coated layer.
Further, according to the invention, each surface of the first, second and third guide rollers is coated with a fluororesin and the fluororesin may be, for example, polytetrafluoroethylene or the like which is commercially available as Teflon (commercial name). By such a coated layer, the frictional coefficient thereof in respect of the multifilament yarn is reduced and accordingly, the respective filaments can be opened smoothly in the fiber axes direction.
According to the invention, by a layer coated with a synthetic resin such as fluororesin, the frictional coefficient thereof in respect of the filament is reduced and accordingly, the multifilament yarn can be opened further uniformly.
Further, in the invention it is preferable that means for removing static electricity of the multifilament yarn on the upstream side of the first guide roller in the running direction of the multifilament yarn is provided.
Further, according to the invention, the means for removing static electricity is provided on the upstream side of the first guide roller thereby removing electricity of the multifilament yarn. Thereby, the plurality of filaments can be opened by uniformly arranging the filaments with no overlapping at the first, second and third guide rollers. When the multifilament yarns is charged with static electricity, repulsive force caused by static electricity is operated on the respective filaments constituting the multifilament yarn. Such a static electricity is not distributed uniformly in the direction orthogonal to the fiber axis of the multifilament yarn and intervals among the filaments may become nonuniform after the opening operation. According to the invention, in order to resolve the problem, electricity is removed, by which the multifilament yarn can be opened by arranging the filaments contiguous to each other or at equal intervals, that is, making uniform the density in the direction orthogonal to the fiber axis.
According to the invention, the uniform opening operation can be performed by removing electricity from the filament yarn and no dispersion is caused in the intervals between the respective filaments by a repulsive force of nonuniform static electricity.
The invention provides a woven fabric comprising:
non-twisted multifilament yarns opened by arranging filaments such that a cross-sectional shape thereof is flattened as a whole, the non-twisted multifilament yarns being used as warps and wefts,
wherein weaving is performed while keeping fiber axes of the filaments substantially linear, and
wherein either one of the warp and the weft is superior to the other in mechanical property and the other is superior to the one in thermal property.
According to the invention, the multifilament yarn is opened by arranging a plurality of filaments constituting the multifilament yarn such that the cross-sectional shape of the multifilament yarn is flattened as a whole and the multifilament yarn is not twisted, that is, non-twisted and subjected to no working. Accordingly, in respect of the multifilament yarn used in the invention, the orientation of fibers is excellent, the density is high and accordingly, mechanical properties for enhancing the bulletproof ability are excellent, for example, the tensile strength and the initial tensile modulus have sufficiently large values. Furthermore, the filament yarn is non-twisted, is not subjected to working such as entanglement or the like and no crimp is caused. Therefore, the shockwave caused in impacting a bullet discharged from a gun to the woven fabric, propagates smoothly in the filaments, the kinetic energy of the bullet is dispersed in the woven fabric in a wide range and the kinetic energy of the bullet is dissipated by being efficiently converted into breakage of the filaments.
According to the invention, the fiber axes of the filaments are kept substantially linear and no twist and crimp or the like are present as mentioned before and accordingly, the bulletproof ability is enhanced as described above.
According to the invention, the fabric is woven while keeping the fiber axes of the filaments constituting the multifilament yarn substantially linear, and accordingly the mechanical properties of the multifilament yarn are effectively used, that is, the multifilament yarn can be used without deteriorating the tensile strength and the initial tensile modulus by which the kinetic energy of bullet discharged from the gun can be propagated and dispersed in a wide range and by which the kinetic energy can be converted in a short period of time into energy for breaking fibers or the like such that a body is not injured. In this way, the bulletproof ability of the bulletproof woven fabric is enhanced. According to the bulletproof woven fabric of the invention, the bulletproof ability that is uniform in all the directions in the face of the woven fabric can be attained.
Further, according to the invention, compared with a multifilament yarn having a sectional face in, for example, a substantially circular shape, the gaps at crossing points of warps and wefts can be reduced by which the bulletproof ability can further be enhanced.
Further, according to the invention, the cross-sectional face shape of the multifilament yarn is flattened as a whole by the opening operation and accordingly, the gaps at the positions of crossing warps and wefts are reduced by which the bulletproof ability can further be enhanced.
Further, according to the invention, the multifilament yarn is difficult to loosen after the fabric is woven, the original shape is maintained and accordingly, even when the multifilament yarn is used in a state of being worn by a human body, there is no concern of deteriorating the bulletproof ability.
Further, according to the invention, by using the opened multifilament yarns as warps and wefts, the gaps are reduced as mentioned above, the respective filament yarns are difficult to loosen after weaving the fabric, the original weaving texture can be maintained and the shape of the bulletproof woven fabric when the bulletproof woven fabric is actually worn as, for example, a bulletproof jacket or the like, is difficult to deform unintentionally.
According to the invention, one of the warp and the weft is excellent in mechanical property and the other is excellent in thermal property. Therefore, the kinetic energy of a bullet can be instantaneously propagated and dispersed in a wide range and converted into other energy effecting no injuries to a body or the like and the bulletproof ability can be maintained even under high temperature condition by the other of the warp and the weft excellent in thermal property. Excellency in mechanical property signifies that the tensile strength and the initial tensile modulus are large and signifies further that Young's modulus is large. Further, excellency in thermal property signifies that a softening point and a melting point are high, signifies that thermal decomposition temperature is high and heat resistance is excellent and signifies further that thermal fatigue performance is excellent. Also, the excellency signifies that flame resistance is excellent.
According to the invention, the warp and weft individually have excellent mechanical and thermal properties, respectively and therefore, the woven fabric is excellent both in mechanical and thermal properties and is not soften or molten by a bullet at high temperatures and further, the kinetic energy of the bullet can be propagated and dispersed instantaneously in a wide range and converted into other energy effecting no injury on a body or the like and the bulletproof ability can be enhanced.
Further, in the invention it is preferable that the one is of polyethylene fiber and the other is of aramide fiber.
According to the invention, by using polyethylene fiber, the mechanical properties of the woven fabric are improved and the tensile strength and initial tensile modulus are increased. Further, by using aramide fire such as Kevlar, the heat resistance is enhanced and drawbacks of polyethylene fiber where the softening point and the melting point are low are complemented. Also, polyethylene fiber is superior to aramide fiber in mechanical property which complements the mechanical properties of aramide fiber. Polyethylene fiber is softened and molten at about 80° C. whereas aramide fiber has a melting point of 320 through 570° C. and excellent in heat resistance.
According to the invention, polyethylene fiber is excellent in mechanical property and aramide fiber is excellent in thermal property thus realizing a woven fabric having excellent properties of both.
Further, in the invention it is preferable that the polyethylene fiber has a tensile strength of 30 g/d or more and an initial tensile modulus of 900 g/d or more.
According to the invention, it has been confirmed that by providing polyethylene fiber having the tensile strength of 30 g/d or more and the initial tensile modulus of 900 g/d or more, the bulletproof ability can be secured and the kinetic energy discharged at a close range of a gun can be converted into other energy effecting no injures to a body. The tensile strength is preferably about 40 d/g or more and the initial tensile modulus is preferably 1.0 g/d or more.
According to the invention, the tensile strength and the initial tensile modulus of polyethylene fiber are enhanced by which the bulletproof ability is enhanced.
Further, in the invention it is preferable that the multifilament yarn is of 70 through 1200 deniers and each of the plurality of filaments constituting the multifilament yarn is of less than 10 deniers.
According to the invention, the multifilament yarn comprising filaments having counts of 1 through 10 deniers, preferably, 2 through 9 deniers is made to have a count of 70 through 1200 deniers, preferably 200 through 1000 deniers and the orientation of the fiber is improved, to obtain a woven fabric woven at high density, whereby a woven fabric sufficiently achieving the mechanical properties of the multifilament yarn, for example, excellent in the bulletproof ability can be realized.
According to the invention, a woven fabric utilizing excellent characteristics of the multifilament yarn having excellent orientation of fiber and high density, is realized by which a woven fabric excellent in mechanical property is realized.
Further, the invention provides a woven fabric comprising:
non-twisted multifilament yarns opened by arranging filaments such that a cross-sectional shape thereof is flattened as a whole, the non-twisted multifilament yarns being used as warps and wefts,
wherein weaving is performed while keeping fiber axes of the filaments substantially linear, and
wherein either one of the warp and the weft is a combined filament yarn having different mechanical and thermal properties.
According to the invention, one or both of the warp and the weft is a combined filament yarn. That is, a plurality of filaments constituting the multifilament yarn comprise, for example, polyethylene fibers and aramide fibers and a single multifilament yarn is constituted by mixing together the two kinds of filaments separately one by one. Two kinds or more of filaments may be used.
Further, according to the invention, the woven fabric may be a union cloth. That is, the warp may comprise polyethylene fibers and aramide fibers and the weft may comprise polyethylene fibers and aramide fibers, or only the weft may comprise either one of polyethylene fibers and aramide fibers and the weft may comprise the other of polyethylene fibers and aramide fibers.
The invention can not only be used as a bulletproof woven fabric but can be executed in a wide range of usage requiring strength and heat resistance such as an airship, a balloon or the like, in musical instruments and further, in other usages.
According to the invention, either one or both of the warp and the weft is a combined filament yarn and accordingly, as mentioned above, a woven fabric excellent in mechanical property and thermal property is realized.
BRIEF DESCRIPTION OF THE DRAWINGS
Other and further objects, features, and advantages of the invention will be more explicit from the following detailed description taken with reference to the drawings wherein:
FIG. 1 is a side view of a warping apparatus 1 according to an embodiment of the invention;
FIG. 2 is a plane view of the warping apparatus 1;
FIG. 3 is a plane view showing a vicinity of a bobbin 13 in a creel 2;
FIG. 4 is a plane view of tension applying means 17;
FIG. 5 is a side view of the tension applying means 17;
FIG. 6 is a side view of a modified example according to the embodiment of the invention in place of the constitution shown by FIG. 3 through FIG. 5;
FIG. 7 is a side view of an opening apparatus 4;
FIG. 8 is a longitudinal sectional view viewing a sizing apparatus 6 from a side direction;
FIG. 9 is a longitudinal sectional view viewing a drying apparatus 6 from a side direction;
FIG. 10 is a simplified plane view showing a multifilament yarn 3 dried by the drying apparatus 6 and wound by a winding apparatus 7;
FIG. 11 is a view showing in a simplified manner an apparatus for continuously bundling each of a multifilament yarn 3d and multifilament yarns 3e through 3h having a similar constitution to that of the multifilament yarn 3d, which are obtained from the constitution of FIG. 1 through FIG. 10 and wound by a beam 8, and rewinding them to a warp beam 62 by a beaming apparatus 61;
FIG. 12 is a simplified perspective view of the warp beam 62;
FIG. 13 is a perspective view showing a simplified portion of a water jet loom 68;
FIG. 14 is a sectional view showing in a simplified manner a portion of a pooling pipe 97 and the constitution of a blowing block 98 connected to a base end portion of the cooling pipe 97;
FIG. 15 is a sectional view orthogonal to the axial line of the pooling pipe 97;
FIG. 16 is a sectional view of a water jet nozzle 74;
FIG. 17 is a simplified perspective view showing a portion of the water jet loom 68;
FIG. 18 is a plane view enlarging a woven fabric 85 woven by the above-described embodiment of the invention; and
FIG. 19 is a plane view magnifying the multifilament yarn 3 according to still other embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now referring to the drawings, preferred embodiments of the invention are described below.
FIG. 1 is a side view of a warping apparatus 1 according to an embodiment of the invention and FIG. 2 is a plane view of the warping apparatus 1. In respect of a plurality of multifilament yarns 3 (e.g., 600 yarns) from a creel 2, filaments are parallelly placed such that a cross-sectional shape of each multifilament yarn 3 is flattened as a whole by an opening apparatus 4, and thereafter the filaments are sized by a sizing apparatus 5. After the size is dried by a drying apparatus 6, the filaments are wound to the beam 8 or a drum by the winding apparatus 7.
Electricity removing means 10 for removing static electricity of the multifilament yarns 3 is installed at a vicinity of the creel 2 on the downstream side in a direction 9 of running the multifilament yarns 3 and means 11 for removing static electricity of the multifilament yarns 3 is installed on the upstream side of the opening apparatus 4 in the running direction 9 and further, means 12 for similarly removing static electricity is installed also between the drying apparatus 6 and the winding apparatus 7. The means 10, 11 and 12 for removing static electricity remove electricity from the multifilament yarns 3 by ionizing air. Thereby, the repulsive force and the attractive force among the multifilament yarns and among a number of filaments constituting the respective multifilament yarns, are eliminated by which the opening operation of the opening apparatus 4 can accurately be performed and the winding operation of the multifilament yarns 3 to the beam 8 at the winding apparatus 7 can be performed accurately.
Bobbins 13 each having a horizontal axial line are mounted to the creel 2 and the multifilament yarns 3 wound to the respective bobbins 13 are drawn.
FIG. 3 is a plane view showing a vicinity of the bobbin 13 in the creel 2. The multifilament yarn 3 wound by the bobbin 13 is denoted by a reference notation 3a. The bobbin 13 is supported by a peg 14 provided in the main body of the creel 2 by which the bobbin 13 is rotatably supported. Each of the multifilament yarns 3 is inserted into each guide hole 16 of a guide member 15 fixed to the creel 2 and is led to the means 10 for removing static electricity via the tension applying means 17 for applying tension to the multifilament yarn 3 drawn from the bobbin 13. The guide hole 16 of the guide member 15 is arranged to orthogonally shift from a vertical axial line 18 of the bobbin 13 (left of FIG. 1 and FIG. 3). The multifilament yarn 3 is inserted into and guided by the guide hole 16 within a range W1 of a layer of the multifilament yarn 3a wound along the direction of the axial line 18 of the bobbin 13 (up and down direction of FIG. 2 and FIG. 3). The guide hole 16 is installed at the central position of the range W1 in the up and down direction of FIG. 3. The multifilament yarn 3 can smoothly be drawn by the constitution of FIG. 3 without causing twist.
FIG. 4 is a plane view of the tension applying means 17 and FIG. 5 is a side view thereof. A support shaft 19 having a straight cylindrical shape and a horizontal axial line is erected at the main body of the creel 2. A pair of upper and lower tension washers 20 and 21 are individually, rotatably and coaxially inserted with the support shaft 19. A weight 24 is mounted on the upper tension washer 20. By changing the weight amount by exchanging the weight 24, the gravitational force of the weight 24 and the like operating on the respective multifilament yarn 3 inserted through the upper and lower tension washers 20 and 21, and accordingly the tension can be adjusted. Outwardly directed flanges 22 and 23 which are bent in mutually separating directions along the support shaft 19 are formed at the outer peripheral portions of the tension washers 20 and 21 by which the multifilament yarn 3 can be passed smoothly. The constitution shown by FIG. 3 through FIG. 5 has an advantage where no twist is applied to the multifilament yarn 3 drawn from the bobbin 13.
FIG. 6 is a side view showing a modified example of the embodiment of the invention in place of the constitution shown by FIG. 3 through FIG. 5. According to the embodiment, the guide member 15 is installed in a direction along the axial line 18 of the bobbin 13 and the multifilament yarn 3 is drawn via the tension applying means 17. The multifilament yarn 3 is made to wrap on the support shaft 19 of the tension applying means 17 by an angle of contact of substantially 90° and is led to the means 10 for removing static electricity. The bobbin 13 is fixed to the support shaft 19 and is not rotated. According to the constitution shown by FIG. 6, although twist is slightly applied to the multifilament yarn 3 drawn from the bobbin 13, the twist practically effects no hazard and the opening operation of filaments in the succeeding opening apparatus 4 can be performed accurately.
FIG. 7 is a side view of the opening apparatus 4. In the opening apparatus 4, first, second and third guide rollers 25, 26 and 27 are arranged in this order in a running direction 9 of the multifilament yarn 3 led by guide rollers 93 and 94. The guide rollers 25, 26 and 27 each have an outer diameter uniform in the horizontal axial line direction (orthogonal to paper face of FIG. 1 and FIG. 7 and up and down direction of FIG. 2), that is, each of the guide rollers has a straight column shape or a straight cylindrical shape and a rotational axis line orthogonal to the running direction 9. The respective guide rollers 25, 26 and 27 each are constituted by forming a fluorine resin coated layer on the outer peripheral face of the roller main body made of a metal such as stainless steel or the like by which the frictional coefficient between the coated layer and the multifilament yarn 3 is reduced thereby enabling the smooth running of the multifilament yarn 3. The fluorine resin may be, for example, polytetrafluoroethylene or Teflon (commercial name) or the like.
The rotational axis lines of the guide rollers 25, 26 and 27 are denoted by reference notations 29, 30 and 31. The axis line 30 is arranged to shift to one side (lower side of FIG. 7) of a horizontal plane including the axis lines 29 and 31. The multifilament yarn 3 is guided by being wrapped on firstly the other side (upper side of FIG. 7) of the guide roller 25 in respect of the plane, successively the outer peripheral face of the guide roller 26 on the one side (lower side of FIG. 7) in respect of the plane and at the lower side of FIG. 7 remote from the plane, and further, on the other side (upper side of FIG. 7) of the roller 27 in respect of the plane.
The outer diameters of the guide rollers 25 and 26 are the same and set at a value exceeding the outer diameter of the guide roller 27.
Direct current motors 32, 33 and 34 constituting driving means are respectively connected to the guide rollers 25, 26 and 27. When peripheral speeds of the rollers 25, 26 and 27 are designated by notations V1, V2 and V3, the direct current motors 32, 33 and 34 are driven to rotate forwardly in the running direction of the multifilament yarn 3 such that the following relationship is established.
V1>V2>V3 (1)
The tension applying means 17 is installed in the creel 2 upstream from the guide roller 25 of the opening apparatus 4 in the running direction 9. Downstream from the guide roller 27 of the opening apparatus 4 in the running direction 9, a reed 35 for regulating the width of a plurality of the multifilament yarns 3 are installed at the winding apparatus 7. Controlling means 36 is connected to the motors 32, 33 and 34 and controls the speeds of the respective motors 32, 33 and 34. Thereby, between the rollers 25 and 26, the tension of the multifilament yarn denoted by a reference notation 3b is lowered upstream therefrom and the tension of the multifilament yarn denoted by a reference notation 3c is lowered between the rollers 26 and 27 by which on the outer peripheral face of the guide roller, respective filaments constituting the multifilament yarn 3c are disposed contiguously one by one without overlapping in the up and down direction or parallelly disposed with slight intervals therebetween and opened and led to the sizing apparatus 5 on the downstream side.
FIG. 8 is a longitudinal sectional view viewing the sizing apparatus 5 from a side direction. A liquid size 38 is stored in a size box 39. The size 38 supplied from a supply tube 41 is made to overflow from an overflow hole 40 installed at the size box 39 by which the liquid level of the size 38 is kept constant. In the size box 39, sizing rollers 42 and 43 each having a horizontal axial line are installed at an interval on the upstream side and the downstream side in the running direction 9 of the multifilament yarn 3. Each of the sizing rollers 42 and 43 has an outer diameter uniform in the axial line direction. Lower portions of the rollers 42 and 43 are disposed below the liquid level 44 of the size 38 and dipped partially in the size. The multifilament yarn 3 is run in contact with the upper portions of sizing rollers 42 and 43. The sizing rollers 42 and 43 are driven to rotate by direct current motors 45 and 46 at peripheral speeds V4 and V5 such that the rotational direction is, for example, set to be reversed to the running direction 9 of the multifilament yarn 3 at the upper portions thereof in contact with the multifilament yarn 3. The motors 45 and 46 are controlled by a control device 47.
The peripheral speeds V4 and V5 are under a relationship therebetween of, for example, V4=V5 and are set to change in accordance with the count of the multifilament yarn 3 and further, the rotational directions thereof are also controlled. For example, when the count of the multifilament yarn 3 is, for example, 1200 deniers or more, or 1300 deniers or more, the sizing rollers 42 and 43 are driven to rotate in the reverse direction as mentioned above by which the size 38 is firmly adhered to the multifilament yarn 3. By contrast, when the count of the multifilament yarn 3 is less than 1200 deniers, for example, in a range of 600 through 1200 deniers, the rotational directions of the sizing rollers 42 and 43 are reverse to arrow marks indicated in FIG. 8. That is, the sizing rollers 42 and 43 are driven to rotate forwardly in the running direction 9 at upper portions thereof in contact with the multifilament yarn 3. As the count of the multifilament yarn 3 is increased, the forward peripheral speeds V4 and V5 are reduced or to null or increased in the reverse direction by which the relative speed difference between the peripheral speeds V4 and V5 of the sizing rollers 42 and 43 and a running speed V0 of the multifilament yarn 3 is increased whereby the size 38 is adhered to the multifilament yarn 3 firmly and uniformly. Rollers 50 and 51 for guiding the multifilament yarn 3 are installed on the upstream side of the sizing roller 42 and on the downstream side of the sizing roller 43.
Fig .9 is a longitudinal sectional view viewing the drying apparatus 6 from a side direction. A housing 54 is formed with an inlet 52 and an outlet 53 for the multifilament yarn 3 and the multifilament yarn 3 runs in the housing 54. A heat source 55 is installed in the housing 54 and air is circulated from the downstream side to the upstream side in the running direction 9 by a blowing apparatus 56 as shown by an arrow mark 57. The heat source 55 may be of a constitution where, for example, vapor is supplied and indirect heat exchange is performed between the vapor and air, or a constitution where an electric heater is embedded therein to heat an infrared ray radiator. The housing 54 is formed with lids 58 and 59 openable by a horizontal pin 89 as illustrated by imaginary lines thereby facilitating maintenance and check in cutting the multifilament yarn 3 during the drying operation and further, circulated air is partially dissipated to the atmosphere to discharge gas after drying.
The temperature of air in contact with the multifilament yarn 3 falls in a range of, for example, 40 through 60° C., preferably, 40 through 50° C. Thereby, the size can be dried even when the multifilament yarn 3 is constituted by polyethylene fibers having comparatively low heat resistance. The drying apparatus 6 is not limited to the constitution shown by FIG. 9 but may be of other constitution.
Referring again to FIG. 1, the multifilament yarn 3 the size of which has been dried by the drying apparatus 6, is wound to the beam 8 by the winding apparatus 7 via the means 12 for removing the static electricity. The multifilament yarn 3 is provided with a tension by the beam 8, guided by a roller 58 and is wound to the beam 8 disposed below the roller 58. The beam 8 is driven to rotate by a direct current motor 59. The creel 2 is provided with, for example, 600 bobbins 13 wound with multifilament yarns 3 and 600 of the multifilament yarns 3 are simultaneously opened by the opening apparatus 4, sized, dried and wound to the common beam 8.
FIG. 10 is a simplified plane view of the multifilament yarns 3 dried by the drying apparatus 6 and wound to the beam 8 by the winding apparatus 7. The respective multifilament yarns 3 each comprising 195 of filaments as described above, are sized in a flat sectional shape and wound to the beam 8 in a straight cylindrical shape contiguously in the axial direction at intervals as denoted by a reference notation 3d.
FIG. 11 is a view showing in a simplified manner an apparatus for winding contiguously in the axial direction of a beam 66 a total of 3000 (=600×5) multifilament yarns including multifilament yarns 3d through 3h and multifilament yarns 3e through 3h having the same constitution as that of the multifilament yarns 3d through 3h, obtained from the constitution of FIGS. 1 through 10, to a single warp beam 62 by a beaming apparatus 61. According to the beaming apparatus 61, as mentioned above, 3000 of the respective multifilament yarns 3d through 3h are guided by rollers 63 through 65 and the respective filament yarns are disposed closely contiguous to each other at the beam 66 and wound for weaving by a succeeding weaving machine. The beam 66 is driven to rotate by a direct current motor and winds the multifilament yarns 3d through 3h by applying a pertinent tension for each thereof by braking the drum 66.
FIG. 12 is a simplified perspective view of the finished warp beam 62. The respective multifilament yarns 3d through 3h are wound by the drum 66 closely contiguous to each other in the axial direction by which the weaving preparatory process is finished.
The warp beam 62 is woven to a bulletproof woven fabric by a water jet loom 68 shown by FIG. 13. The multifilament yarn 3 shown by FIGS. 1 through 11 is used as a warp. Throughout the specification, the reference notation 3 summarizingly represents the reference notations 3a through 3h and is used to represent a multifilament yarn used as a warp and a warp.
In respect of the water jet loom 68, a weft 69 that is a multifilament yarn, is wound by a bobbin, that weft 69 is not twisted nor subjected to opening and sizing operations. The length of the weft 69 for one weaving portion 72 is determined by a measuring roll 70 and a hold roller 71, and the weft 69 is extended from the bobbin 60 and stored in a pooling pipe 97 to enter a water jet nozzle 74 via a guide piece 73 at a pertinent timing. Separately, water in a tank 75 is made to enter the nozzle 74 from a jet pump 76. In the nozzle 74, water and the weft 69 are jointed together, the weft 69 is flown by a jet stream of water and is put into weft inserting motion for inserting into a shed that is an opening formed by upper and lower ones of the warps 3. The weft 69 is cut by cutting means 91 and 92 at both end portions of a weave width W2. Such a series of operations are repeated.
FIG. 14 is a sectional view showing a portion of the pooling pipe 97 and a blowing block 98 connected to a base end portion thereof. In respect of the weft 69 from the length measuring roll 70 and the hold roller 71, compressed air pressurized and fed from a fan 99 is led to an air chamber 100 of the block 98 and is injected from nozzle holes 101 inclined to the downstream side (right of FIG. 14) toward the axial line along a straight line of the weft 69. By injection of air from the nozzle holes 101, the weft 69 is dragged and stored in the pooling pipe 97. By dragging the weft 69 in the pooling pipe 97, the plurality of filaments constituting the weft 69 are disintegrated apart and brought into a so-called opened state.
FIG. 15 is a sectional view orthogonal to the axial line of the pooling pipe 97. A notch 102 is formed at a side portion of the pooling pipe 97 along the axial line of the pooling pipe 97. The one weaving portion 72 of the weft 69 dragged into the pooling pipe 97 by compressed air from the nozzle holes 101, is taken out from the notch 102 and guided to the guide piece 73. The filaments opened in the pooling pipe 97 are opened also at the nozzle 74 mentioned below, and constitute the multifilament yarns each having a cross-sectional face of a shape flattened as a whole by arranging the respective filaments by the warps. A free end portion of the pooling pipe 97 opposed to the blowing block 98 is opened.
FIG. 16 is a sectional view of the water jet nozzle 74. The weft 69 is led to a chamber 77 in which high pressure water is supplied from a pump 76 and the weft 69 and water are injected together from a nozzle hole 78 as denoted by a reference notation 79. The shape of the nozzle hole 78 is constituted such that water is easy to converge and fly and the speed of the jet stream is determined such that water is kept in a shape of a water rod and water is not atomized. The injection of water is carried out over an entire length of the weft 69 in a state of flying the weft 69 or finished in the midst of flying and thereafter, the weft 69 is kept flying by the inertia and viscosity of water. Accordingly, even if the jet stream is shifted from the weft, there causes no push up from behind by which meandering of the weft 69 can be prevented.
According to the invention, the weft 69 is flown by using water and therefore, the weft 69 is brought into an opened state while flying the weft 69 in which the orientation of fiber is kept excellent and the weft 69 is kept in a state where intervals among the filaments are slightly separated apart. In this way, the flow rate, the speed, the pressure, the injection time period and the like of the water jet stream are adjusted, and the pump 76 and the driving means 80 for driving the pump 76 such as a cam or the like are constituted.
FIG. 17 is a simplified perspective view showing a portion of the water jet loom 68. The warps 3 loomed to the loom 68 as the warp beam 62, are separated upwardly and downwardly by a heald 81, the shedding motion for producing a shed 82 for passing the wefts 69 is performed, the weft 69 flown by the water jet described in reference to FIG. 13, is inserted into the shed 82 and thereafter, the reed 83 is advanced to right of FIG. 17 and the weft 69 is pushed to the weave front thereby performing a beating-up motion.
According to experiments of the inventors, it has been confirmed that in respect of the water jet loom 68, the weaving operation could be performed by the weft inserting motion of the weft from the nozzle 74 at a high speed of 430 times/minute.
According to the invention, a shuttleless loom such as an air jet loom, a gripper shuttle loom, a Rapier loom or the like may be used in place of the water jet loom.
FIG. 18 is a plane view enlarging a woven fabric 85 that is woven in accordance with the embodiment of the invention. The warps 3 and the wefts 69 are woven in a plain weave and the warps 3 and the wefts 69 are brought into a state of being opened. The woven fabric is desized. The desizing operation is carried out by using a desizing agent. Further, the degumming operation is performed for cleaning the woven fabric. Incidentally, the desizing and degumming may be omitted.
It is preferable that the multifilament yarn 3 that is a grey yarn used as the warp, comprises, for example, polyethylene fibers and has a tensile strength of 30 g/d or more and an initial tensile modulus of 900 g/d or more. Each of, for example, 195 filaments constituting the multifilament yarn, has a count of less than 10 deniers. A single one of the multifilament yarns fabricated thereby has a count of, for example, 50 through 1600 deniers, for example, 200 deniers. The weft 69 may be made of a material the same as that of the warp 3. With regard to polyethylene fiber described above, the theoretical strength that is the strength of one molecule is 372 g/d, the molecular chain length that is the length of one molecule is long, the molecular weight of raw material is about 4 or 5 million, directions of molecular chains are aligned by performing melting and superdrawing, a large strength is achieved in a direction of fiber axis and the fiber is also excellent in wear resistance, fatigue resistance, impact resistance and light resistance.
Although the mechanical properties of polyethylene fiber used for the weft 3 and the warp 69 are excellent as described above, the softening and melting point is as low as, for example, about 80° C. Such a problem can successively be dealt with by using polyethylene fiber for either one of the weft 3 and warp 69 and a material excellent in a thermal property, for example, aramide fiber known as kevlar or the like for the other of the weft 3 and warp 69. The softening and melting temperature of aramide fiber is as high as about 320° C. through 570° C. or higher and the mechanical properties are comparable to polyethylene fiber in practice although generally a little inferior thereto. The tensile strength of the multifilament yarn comprising aramide fibers is 20 g/d or higher or 500 g/d or higher.
According to another embodiment of the invention, the woven fabric may be manufactured by employing polyethylene fiber for a portion of the plurality of warps 3 and aramide fiber for the remainder thereof, and similarly with respect to the wefts 69 by mixing the multifilament yarns of polyethylene fiber and aramide fiber. For example, multifilament yarns of 200 deniers each having 195 filaments comprising polyethylene fibers, and multifilament yarns of 200 deniers each having 195 filaments comprising aramide fibers may respectively and alternately be used one by one for the warps and multifilament yarns of 200 deniers having 195 filaments comprising polyethylene fibers and multifilament yarns of 200 deniers each having 195 filaments comprising aramide fibers may respectively and alternately be used one by one for the wefts similar to the warps thereby constituting a plain weave.
FIG. 19 is a plane view enlarging a single multifilament yarn 3 according to still another embodiment of the invention. The multifilament yarn 3 is a combined filament yarn in which a filament denoted by a reference notation 86 may be, for example, of polyethylene fiber and a filament denoted by a reference notation 87 may be, for example, of aramide fiber. The filaments 86 and 87 may be of still other kind of chemical fiber. Further, the single multifilament yarn 3 may be constituted by a combined filament yarn of filaments comprising three or more kinds of chemical fibers. Although the multifilament yarn 3 may be used as the warp, the yarn 3 may be used also as the weft or either one or both of the warp 3 and the weft 69 may be constituted by a combined filament yarn. According to the experiments by the inventors, it has been confirmed that the respective woven fabrics shown by FIG. 18 and FIG. 19 have excellent bulletproof ability and mechanical and thermal properties.
A material of the multifilament yarn may be a fiber formed by subjecting poly(paraphenylene 2,6-benzobisoxazole) to a liquid fiber forming operation and the multifilament yarn may be used both for the warp and the weft, or the warp or the weft. The softening and melting point is about 600° C. or higher, the material is excellent in heat resistance and flame resistance and in mechanical property, extremely flexible, and has a soft feeling. The multifilament made of such a material may be combined with polyethylene fibers or with aramide fibers in a combination as described above.
In this way, according to the invention, a woven fabric which is improved in mechanical and thermal properties by complementing drawbacks of respective multifilament yarns made of a plurality of kinds of materials is realized.
The invention may be embodied in other specific forms without departing from the sprit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and the range of equivalency of the claims are therefore intended to be embraced therein.
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A woven fabric enhancing bulletproof ability by efficiently absorbing kinetic energy of a bullet discharged from a gun, which is not softened or molten by heat of the bullet at high temperatures, in which non-twisted multifilament yarns are opened and the filament yarns are aligned such that the cross-sectional shape thereof is flattened as a whole and the fabric is woven while keeping fiber axes of the filaments substantially linear. Warps and wefts comprise such multifilament yarns, the warp comprising polyethylene fibers excellent in mechanical property, the weft comprising aramide fibers excellent in thermal property. In order to prevent lowering of the bulletproof ability caused by crimping or the like of the multifilament yarns and to sufficiently utilize the mechanical properties of the fiber material, multifilament yarns each having a count of 50 through 1600 deniers comprising filaments each having a count of less than 10 deniers are used as the warps and wefts. In respect of the warps, the multifilament yarns are woven by a water jet loom after being opened, sized and dried, and in respect of the wefts, the multifilament yarns are woven by a water jet loom without being subjected to the opening and sizing operation.
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FIELD OF THE INVENTION
Various embodiment of the invention relate generally to cryptography engines and more particularly to distributed cryptography systems and accelerators.
BACKGROUND
Cryptography is utilized in numerous and various applications requiring manipulation of digital data. In most, if not all, such applications, such as storage and networking to name a couple among many others, latency and speed are not commodities. Rather, performance is quite valuable particularly due to the fast-improving nature of digital technology resulting in faster and faster components and therefore systems. Latency is undesirable in applications utilizing cryptography.
Accordingly, there is a need for cryptography systems with higher performance and latency.
SUMMARY
Briefly, a distributed cryptography system coupled to a host and configured to perform cryptography tasks initiated by the host. The distributed cryptography system comprises one or more working knots. One of the plurality of working knots is in communication with the host and performs one or more cryptography tasks and forwards the remaining cryptography tasks to another one of the working knots. The working knots include crypto engines and are operable to perform the cryptography tasks such as symmetric encryption.
A further understanding of the nature and the advantages of particular embodiments disclosed herein may be realized by reference of the remaining portions of the specification and the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a distributed cryptography system, in accordance with an embodiment of the invention.
FIG. 1 a shows an example of an application of the distributed cryptography system 1 , in accordance with an embodiment of the invention.
FIG. 2 shows a working knot, in accordance with an embodiment of the invention.
FIG. 2 a shows another example of working knot, in accordance with another embodiment of the invention.
FIG. 3 shows an example of distributed cryptography system, in accordance with another embodiment of the invention.
FIG. 4 shows an example of distributed cryptography system, in accordance with yet another embodiment of the invention.
FIG. 5 shows example of working knot, in accordance with yet another embodiment of the invention.
FIG. 6 shows an example of local workshop, in accordance with embodiment of the invention.
FIG. 6 a shows an example of working cell, in accordance with embodiment of the invention.
FIG. 7 shows a flow chart 100 of the relevant steps performed by distributed cryptography system.
FIG. 8 shows a more detailed flow chart 200 of the relevant steps performed by distributed cryptography system.
DETAILED DESCRIPTION OF EMBODIMENTS
Particular embodiments and methods of the invention disclose a distributed cryptography system having a plurality of working knots capable of perform cryptography. One of the working knots is in communication with a host and receives cryptography tasks. It performs one or more of the tasks and forwards the remaining tasks to another one of the working knot.
The following description describes a distributed cryptography system. The cryptography system employs a plurality of working knots, each working knot capable of performing cryptography tasks and forwarding the host data to another working knot if it is busy, as discussed below.
Referring now to FIG. 1 , a distributed cryptography system 1 is shown, in accordance with an embodiment of the invention. The distributed cryptography system 1 is shown coupled to a host 2 via an interface 6 . The system 1 is further shown to include an ‘X’ number of working knots 4 ; working knots 4 - 1 through 4 -X, ‘X’ being an integer value.
One or more of the working knots 4 is in communication with the host 2 through the interface 6 . The working knot that is communicating with the host 2 receives cryptography tasks, along with cryptography task associated data, from the host 2 . The working knot in receipt of the cryptography tasks from the host 2 maintains one of the cryptography tasks, or keeps as many cryptography tasks as it can immediately perform, and forwards the remaining cryptography tasks to an adjacent working knot. The adjacent working knot might do the same depending on the number of cryptography tasks and the number of working knots. Thus, the remaining working knots perform cryptography on some of the cryptography tasks while the remaining cryptography tasks flow through to the cascaded working knots. Accordingly, each of the working knots that receives one or more of the remaining cryptography tasks, performs a cryptography process, such as but not limited to encryption/decryption, immediately. Thus, the cryptography tasks are performed, at least in part, in parallel (or substantially concurrently) with the distribution of the cryptography tasks to the working knots. Clearly, performance and efficiency are increased as a result. Stated differently, while one or more cryptography tasks are performed by a working knot, the remaining cryptography tasks are forwarded through the working knots to be performed by another one of the working knots that is capable of performing the task immediately.
As can be appreciated, the cryptography system 1 has many applications, too numerous to list, one such example is by an encryption accelerator card used in banks to perform security transactions. In most applications, the host 2 is the task initiator and the cryptography system 1 is the performer of the cryptography tasks.
In an embodiment of the invention, the interface 6 is a Universal Serial Bus (USB) or a Peripheral Component Interconnect Express (PCIe)-compatible bus, or any other suitable bus. In an embodiment of the invention, the host 2 is PC, SUN Server, IBM mainframe and so on. FIG. 1 a shows an example of an application of the distributed cryptography system 1 , in accordance with an embodiment of the invention. The distributed cryptography system 1 is shown in use at a bank 3 ; the bank 3 being an example of the host 2 . The bank 3 is shown to include a number of users 7 ; such as bank tellers and bank employees, with each of the users 7 being in communication with a bank server 8 for performing various banking transactions.
In FIG. 1 a , the server 8 is shown to be coupled with the distributed cryptography system 1 and in communication with the working knot 4 - 1 . The working knot 4 - 1 receives all of the cryptography tasks initiated by the users 7 . The working knot 4 - 1 then performs cryptography on one or more of the received cryptography tasks and forwards the rest of the tasks to working knot 4 - 2 ; the working knot 4 - 2 performs similarly, and so on. FIG. 2 shows further details of the working knot 4 , in accordance with an exemplary embodiment of the invention. The working knot 4 is shown to include a device interface 11 , a local workshop 10 and a cascaded interface 13 . The device interface 11 is shown coupled to the cascaded interface 13 of another working knot 4 and to a local workshop 10 . While not shown in FIG. 2 , the device interface 11 is further coupled to the host 2 of FIG. 1 .
In some embodiments, the device interface 11 may be PCIe, SATA, SAS, IEEE1394, SD, eMMC or SPI-compliant. As used herein “compliant” refers to adherence to an industry standard, as defined by an industry-adopted specification.
The device interface 11 receives cryptography tasks form the host 2 and either forwards them to the local workshop 10 , assuming the local workshop 10 is not busy performing other cryptography tasks, or forwards the tasks to the cascaded interface 13 . While not shown in FIG. 2 , the cascaded interface 13 is coupled to the device interface 11 of an adjacent working knot. In situations where the local workshop 10 is busy, the cascaded interface 13 forwards the task(s) and their associated data to another one of working knots in an effort to accelerate performance of the tasks. As such, the cryptography tasks issued by the host 2 are performed at a much faster rate in a distributed cryptography system 1 (shown in FIG. 1 ).
Examples of cryptography tasks in addition to symmetric encryption and decryption include but are not limited to digital signature, digital certificate, hashing functions, asymmetric encryption and decryption. The number of working knots in the distributed cryptography system depends on the number of the cryptographic tasks issued by the host and required throughput expected by the host 2 .
FIG. 2 a shows a working knot 4 a , in accordance with an exemplary embodiment of the invention. The working knot 4 a is shown to include ‘m’ number of cascaded interfaces 13 ; cascaded interfaces 13 - 1 through 13 - m , ‘m’ being an integer value. The cascaded interfaces 13 - 1 through 13 - m are all shown coupled to the device interface 11 . The local workshop 10 is shown coupled to the cascaded interfaces 13 - 1 - 13 - m as well as to the device interface 11 .
The device interface 11 forwards host cryptography tasks and their associated data (cryptography tasks generated by the host 2 ), received through the interface 6 , to ‘m’ number of working knots. The working knot 4 a is analogous to the working knot 4 with the exception that working knot 4 a has ‘m’ number of cascaded interfaces 13 - 1 through 13 - m and can be in communication with ‘m’ number of other working knots at a given time (or concurrently).
A working knot being in communication with ‘m’ number of other working knots allows speedy transfer of the host cryptography tasks—and their associated data to more than one working knots substantially concurrently, therefore increasing the performance of the distributed cryptography system 1 .
In some embodiments, the speed of the interface from the device interface 11 to the ‘m’ number of cascaded interfaces 13 and to the first working knot, such as one coupled to the cascaded interface 13 - 1 is orders of magnitude faster than like remaining interfaces to the remaining working knots. This is due to the working knot that is in communication with the host having to be fast enough to receive all tasks whereas, the remaining working knots typically do not have the same oblication. In an embodiment of the invention, the device interface 11 includes a PCIe-compatible device controller or USB-compatible device controller and the interface 6 is a PCIe-compatible bus or USB-compatible. In another embodiment of the invention, the cascaded interface 13 is a PCIe-compatible host controller or USB-compatible host controller.
FIG. 3 shows an example of a method and apparatus of the distributed cryptography system 1 employing working knots 4 . The distributed cryptography system 1 is shown to include ‘X’ number of working knots 4 - 1 through 4 -X coupled to one another in a cascaded and serial fashion. The working knot 4 - 1 is coupled to the host 2 through the interface 6 through which it receives host cryptography tasks and their associated data. The working knot 4 - 1 is coupled serially to the working knot 4 - 2 and so on. The working knot 4 - 1 performs cryptography on one of the tasks in its local workshop 10 and forwards the rest of the cryptography tasks to work knot 4 - 2 though its cascaded interface 13 . The working knot 4 - 2 receives the rest of the cryptography tasks from working knot 4 - 1 through its device interface 11 - 2 , performs cryptography on another one of the tasks and forwards the remainder of the tasks to the next working knot in the cascade and so on.
In one embodiment of the invention, the working knot 4 - 1 maintains status of the working knots 4 , in the serial cascade, and sends an adequate number of tasks down in the cascade to try to keep employed all working knots that at the outset are not busy.
FIG. 4 shows another example of a method and apparatus of the distributed cryptography system 1 employing working knots 4 a . The distributed cryptography system 1 is shown to include a number of working knots 4 a coupled to one another in a parallel fashion. The working knot 4 a is coupled to the host 2 through the interface 6 receiving cryptography tasks and associated data therethrough.
The working knot 4 a is shown coupled to ‘m’ number of working knots 4 a - 1 through 4 a - m via interfaces 13 - 1 through 13 - m , similarly, the working knots 4 a - 1 through 4 a - m are each shown coupled to a respective ‘m’ number of working knots 4 a - 1 - 1 through 4 a - 1 - m . The working knot 4 a performs one or more cryptography tasks in its respective local workshop 10 and forwards the remaining cryptography tasks to working knots 4 a - 1 through 4 a - m . The working knots 4 a - 1 through 4 a - m in turn perform one or more of the received cryptography tasks and forward the rest to the remaining working knots 4 a - 1 through 4 a - m and so on. The parallel coupling of the working knots 4 a to one another reduces the propagation of the cryptography tasks amongst the working knots 4 a and further improves the performance of the distributed cryptography system 1 .
In one embodiment of the invention, the interface 13 of one working knot acts as a host or initiator to the next (or adjacent) working knot to which it is coupled and the next work knot similarly acts as the host or initiator to its subsequent working knot and so on until no further cryptography tasks need be performed. The device interface 11 of the working knot acts as a device or target for the previous-stage working knot. For example, referring to the embodiment of FIG. 3 , the working knot 4 - 1 acts as a host to the next stage working knot 4 - 2 and so on. The device interface 11 - 2 acts as device or target for device interface 11 - 1 of the previous stage working knot 4 - 1 .
In some embodiment of the invention, once a working knot completes its cryptography task, it sends the status and result of the task back to the working knot that had initially forwarded the task. This means if there are intermediate working knots, the status and task travel through them to get to the working knot that initially forwarded the task. The result and status are eventually routed back to the host 2 .
Now referring to the example of FIG. 4 , the working knot 4 a - 1 - m sends the result and status of its tasks back to the working knot 4 a - 1 and working knot 4 a - 1 sends the same back to the working knot 4 a . The working knot 4 a either sends the same back to the host 2 or aggregates the result and status of several cryptography tasks before sending them back to the host 2 .
In another embodiment of the invention, the working knot 4 a keeps status of the working knots in the cascade and only sends enough tasks down the cascade to keep the working knots 4 a - 1 through 4 a - m that are not busy performing any cryptography, busy.
In yet another embodiment of the invention, there are only a sufficient number of working knots 4 a to keep up with the cryptography performance required of the distributed cryptography system 1 and all the ‘m’ cascaded interfaces 13 need not be coupled to another one of the working knots 4 a.
FIG. 5 shows another example of the working knot 4 b , in accordance with yet another embodiment of the invention. The working knot 4 b is shown to further include a data buffer 12 and microprocessor 15 , in accordance with an embodiment of the invention. The data buffer 12 is coupled to the device interface 11 , local workshop 10 , microprocessor 15 , and cascaded interface 13 - 1 through 13 - m . The combination of the data buffer 12 is used by the working knot 4 b to receive host cryptography tasks and their associated data, processing some of the tasks, and transferring the rest to the working knots down the chain. The microprocessor 15 is shown to be coupled to the device interface 11 , local workshop 10 , data buffer 12 , and cascaded interfaces 13 - 1 through 13 - m . The microprocessor 15 manages flow of traffic through different structures of the working knot 4 b and keeps track of the other working knots in the chain.
FIG. 6 shows relevant details of the local workshop 10 , in accordance with an embodiment of the invention. The local workshop 10 is shown to include a number of working cells 20 coupled to each other in parallel to accelerate the cryptography operations on the host data. Parallel working cells increase performance.
FIG. 6 a shows relevant details of the working cell 20 , in accordance with yet another embodiment of the invention. The working cell 20 is shown to include a task buffer 22 , crypto engines 24 , and result buffer 26 . The task buffer 22 is coupled to the crypto engines 24 and the crypto engines 22 is coupled to the result buffer. The crypto engines 24 perform cryptography operation (s) on the data in the task buffer 22 and stores the result of the operation in the result buffer 26 .
In one embodiment of the invention, the local workshop 10 is operable to perform cryptography such as symmetric-key cryptography, public-key cryptography, and hash functions. Exemplary symmetric-key cryptography are, without limitation, AES-128, AES-256, DES, or triple DES. The cryptographic hash function includes, without limitation, SHA-1, SHA-2, SHA-3, MD5, or any combination thereof. The pubic-key cryptography includes without limitatiob, Diffie-Hellman key exchange, RSA, DSA, or ECC. The local workshop 10 , the working cell 20 , or the crypto engine 24 is operable to perform, without limitation, any or all of the cryptography function required by the host.
FIG. 7 shows a flow chart 100 of the relevant steps performed by the distributed cryptography system 1 , in accordance with a method of the invention. One of the working knots of distributed cryptography system 1 receives one or more cryptography tasks from a host 2 at step 102 . Next, at step 104 , one of the working knots of distributed cryptography system 1 performs cryptography on one or more of the tasks. At step 106 , a determination is made as to whether or not there are more cryptography tasks. If there are more task; ‘YES’, the process moves to step 108 . At step 108 , the one of the working knots forwards the remaining tasks to the other working knots in the chain and the process move back to step 106 . If at step 106 , there are no remaining tasks to be dispatched to other working knot; ‘NO’, the process proceeds to step 110 where it ends.
FIG. 8 shows a more detailed flow chart 200 of the relevant steps performed by the distributed cryptography system 1 , in accordance with a method of the invention. One of the working knots of distributed cryptography system 1 receives one or more cryptography tasks from a host 2 at step 202 . Next, at step 204 , the one of the working knots of distributed cryptography system 1 performs cryptography on one or more of the tasks. At step 206 , a determination is made as to whether or not there are more cryptography tasks. If there are more task; ‘YES’, the process moves to step 208 . At step 208 , the one of the working knots forwards the remaining tasks to the other working knots in the chain and the process move back to step 206 . If at step 206 , there are no remaining tasks to be dispatched to other working knot; ‘NO’, the process proceeds to step 210 , At step 210 , a determination is made as to whether or not any of the cryptography tasks are completed. If one or more of the cryptography tasks are done by the working knots; ‘YES’, the process proceeds to step 212 . At step 212 , the working knots return the status and the result of the cryptography tasks to the working knots that initiated the tasks and the process proceeds to step 214 . At step 210 , if none of the tasks are completed; ‘NO’, the process waits at step 210 until at least one of the tasks is completed. At step 214 , a determination is made as to whether or not all the cryptography tasks are done. If all the cryptography tasks are completed; ‘YES’, the process ends at step 216 . At step 214 , if all the tasks are not completed; ‘NO’, the process proceeds to step 210 where it waits for completion of at least one of the task.
In some embodiment of the invention, a local workshop of a working knot may be operable to perform a number of cryptography tasks simultaneously.
Although the description has been described with respect to particular embodiments thereof, these particular embodiments are merely illustrative, and not restrictive.
As used in the description herein and throughout the claims that follow, “a”, “an”, and “the” includes plural references unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
Thus, while particular embodiments have been described herein, latitudes of modification, various changes, and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of particular embodiments will be employed without a corresponding use of other features without departing from the scope and spirit as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the essential scope and spirit.
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A card reader controller engine includes an interface controller responsive to information. The engine is coupled to the interface controller and is configured to compress the information before the information is to be stored in a memory card. A master interface is coupled to the engine and is further responsive to the compressed information for storage in the memory card.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit from U.S. Provisional Application No. 60/603,563, filed Aug. 24, 2004.
FIELD OF THE INVENTION
[0002] The present invention relates to an efficiency pumping jack system, particularly, the present invention relates to a well vertical pump jack system for efficiency pumping incorporating an electromagnetic ram.
BACKGROUND OF THE INVENTION
[0003] As is known in the art, various styles of pump jacks have been used in combination with oil wells for many years and as one possibility employ fluid power operated piston and cylinder assemblies for operating the pump jack. The fluid assemblies assist in operating the reciprocating down hole pump, sucker rod and polish rods. Perhaps the most common and oldest pump-jack system known today incorporates a walking beam type which utilizes counterweights, a gear box and a prime-mover such as a rotary electric motor or an internal combustion motor which will run on various fuel sources. These units are typically costly to purchase, large and heavy to transport, time consuming to set up, mechanically inefficient and draw a significant amount of power. They also have a heavy foot-print which is unacceptable in environmentally sensitive areas.
[0004] As is well recognized in the art, the hydraulic pump jack systems are conventionally used on low to medium production wells and unfortunately have low efficiency (approximately 30 percent) and require extensive power. A further limitation is realized in the environmental unfriendliness of such arrangements, namely, oil leaks and misting inter alia.
[0005] Another example of a surface pumping system is referred to as a progressive cavity type pump. Such pumps are employed for use in medium to high volume wells and are particularly useful on wells with heavy sand concentrations or those which are used to produce heavy oil. It has been realized that progressive cavity pumps are not as useful in wells with high hydrogen sulfide concentration or wells containing high concentrations of carbon dioxide. Accordingly, these pumping systems are limited in durability. Another form of a pump jack is a Roto-Flex system. These arrangements have good power efficiency of between 40 and 50 percent and are used in medium to high volume wells and provide for a long stroke capability. Although useful, the Roto-Flex units are not particularly environmentally friendly.
[0006] Yet another variation on the pumping arrangements used in fluid extraction includes the electric submersible type pumping units which are particularly useful for large volume wells with no gas. These arrangements are useful in some situations, but are quite limited in environments where wells contain gas in fluid. They also suffer from significant power consumption and poor performance in heavy oil.
[0007] In terms of hydraulic/pneumatic pump jack systems which are generally surface based, these have the advantage of being relatively inexpensive to setup and can be customized by the user. Such arrangements are only useful for low to medium volume wells and produce medium efficiency. However, although there are advantages to such arrangements these types of pump jacks perform poorly in very hot weather, very cold weather and are environmentally unfriendly.
[0008] A further variation on a pumping system is the conventional “gas lift” system used for removing fluid from a well. These devices require no power and are relatively inexpensive to install and are useful in low volume marginal wells using well gas as the prime mover.
[0009] One arrangement known in the art is shown in U.S. Pat. No. 4,201,115, issued May 6, 1980 to Ogles. The system is an oil well pump jack with dual hydraulic operating cylinders. The arrangement incorporates the cylinders for pivoting the walking beam of the jack and includes a unique control arrangement for controlling operating of the piston and cylinders. The control system also permits operation of the hydraulic piston and cylinder assemblies in a double action mode or a single action mode.
[0010] Saruwatari, in U.S. Pat. No. 4,114,375, issued Sep. 19, 1978, discloses a pump jack device having a double acting piston and cylinder motor with the piston rod of the motor adapted for connection to the polished rod projecting upwardly from the well head.
[0011] In U.S. Pat. No. 4,463,828, issued to Anderson, Aug. 7, 1984, a pump jack is disclosed having a spring handle for cranking the pump jack down and provides a safety lock against accidental unwinding of a helical rod holding the jack on the pole.
[0012] Although the devices previously proposed in the art have merit, it is clear that many of the systems employ hydraulically operated cylinders or gear boxes and motors for actuating the reciprocating pump and other critical components in the well. It would be more desirable to have a high efficiency arrangement which did not suffer from the limitations inherent in these systems. The present invention is directed to alleviating the previous limitations in the art.
[0013] The present invention discussed in greater detail hereinafter virtually eliminates all the problems with prior art conventional crank and hydraulic surface drive and various other pumping systems. This invention results in a surface drive mechanism that is efficient, both in energy used and oil pumped and also limits the stresses on all the surface and downhole mechanical components. The unit requires very little site preparation, is light weight, easy to move, and simple to install. Conveniently, operation is fully computerized and will act as a “smart” pump jack aiding in the optimization of each specific given well.
SUMMARY OF THE INVENTION
[0014] One object of the present invention is to provide an improved oil well pump jack having high efficiency.
[0015] Advantageously, having a system which limits the energy used will reduce and limit peak energy substantially resulting in lower energy costs for the end user. This is particularly important considering the practice of the electricity suppliers to bill the entire year based on the peak energy used, even if the peak is only for a few hours.
[0016] A further object of one embodiment of the present invention is to provide use of an electromagnetic ram for pumping oil from an oil well with a linear pump jack apparatus.
[0017] Significant advantages have been realized via making use of the electromagnetic ram. One of the most advantageous features is the fact that the system is electronic and therefore does not have the limitation of friction loss, atomized leak, cooling, or other significant problems inherent in hydraulic systems. Additionally, the electromagnetic ram arrangement provides for excellent power efficiency in motion and simply does not use any electrical power when the system is static. As a further advantage, the ram can and will act on the down stroke as a power generator returning power to the supply system. This is not possible with hydraulic or any other pump jack systems and represents a distinct advantage over existing prior art pump jacks.
[0018] A further object of one embodiment of the present invention is to provide a pump jack suitable for use on an oil well for pumping fluid from an oil well, comprising: a well head; a support structure connected to the well head; an electromagnetic ram connected to the support structure; a polish rod connected to the electromagnetic ram; pump means connected to the polish rod and rod string for pumping the fluid from the well; and conduit means for transporting recovered fluid pumped from the well.
[0019] By incorporating the electromagnetic ram, the system has been able to achieve greater than 90% efficiency with very desirable properties including a smooth precise response, no mechanical backlash and zero hystersis. The arrangement has only one moving part and provides dual action.
[0020] A still further object of one embodiment of the present invention is to provide a method of pumping from a well containing fluid, comprising: providing a pump jack apparatus having a well head positioned over a well, a reciprocating pump disposed within the well and a support structure for supporting the pump and the well head; providing an electromagnetic ram connected to the pump; actuating the electromagnetic ram; and pumping fluid from within the well.
[0021] Any electromagnetic ram may be incorporated in the system, an example of which is that which is depicted in U.S. Pat. No. 5,440,183, issued Aug. 8, 1995, to Denne.
[0022] This device provides utility in the combination set forth herein and assists in providing a very efficient oil pump jack.
[0023] Particularly convenient is the fact that the arrangement can be employed in any type of fluid well, such as a water well, coal bed methane well, oil well, etc.
[0024] Having thus generally described the invention, reference will now be made to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a schematic illustration of the overall system according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] FIG. 1 schematically illustrates one embodiment of the linear electromagnetic ram artificial lift pump jack system, as well as the downhole components. The conventional wellhead 8 shows the polish rod 7 which passes through a wellhead stuffing box 21 , and connects to a sucker rod 12 . The sucker rod 12 passes down the inside of tubing string 14 to the reciprocating pump 15 . The linear electro-magnetic ram 3 connects to the polish rod 7 by the polish rod clamp 6 . The linear electro-magnetic ram 3 is connected to the support structure 5 by a structure link 1 . The top portion of the structure sits on two weight sensors 2 which measure the weight of the moving pump assembly against the fixed support structure 5 .
[0027] The electrical/pneumatic piping 4 connects the linear electro-magnetic ram 3 , and weight sensors 2 to the controller unit housing 16 . The controller unit housing 16 consists of a sealed weather tight cabinet with controller electronics 9 and the pneumatic controller system 10 inside. The controller unit housing 16 is mounted on a steel mounting post 17 , fixed to the ground 11 .
[0028] The linear electro-magnetic ram 3 works like a rotary stepping motor but instead of rotating, the ram moves in a jacking motion and extends and retracts linearly. The controller 9 and 10 can step the motor a fraction of an inch for each step. With this fractional movement and by varying the stepping rate, the motor can move to precise positions at various speeds. Adjusting the power applied for each step, the force of the movement can be controlled in minute steps. By controlling the stepping rate and the power applied, a smooth movement can be applied to the downhole reciprocating pump with controlled acceleration and deceleration to keep stresses on the sucker rod string 12 to a minimum.
[0029] The weight sensors 2 are monitored by the control electronics 9 during the movement of the linear electro-magnetic ram 3 . If the stress on the pump increases close to the programmed limits, the control electronics 9 will reduce the power applied to the linear electro-magnetic ram 3 protecting all components on/in the well and attached pipeline infrastructure. If a fault causes excessive mechanical stresses, the control electronics 9 will stop the linear electro-magnetic ram 3 to wait for an operator to assess the problem. The flow from the well is monitored by a flow meter 18 . This meter can be any conventional meter such as a turbine or paddle wheel meter which outputs a signal proportional to the flow through the pipeline 19 .
[0030] The controller software (not shown) can be programmed to optimize flow by varying downhole reciprocating pump stroke speed and length. The control software can vary stroke speed/length. Limits can easily be placed on all pump jack parameters as required. For poor producing wells, the control software will see the flow dropping off after a time and reduce either/or the downhole pump speed or length of stroke. The software can also be programmed to give a poor flowing well or “gas locked” reciprocating down hole pump more recovery time by stopping the stroke for a period of time until the formation recovers or until the pump hydrostatically fills with fluid and expels the gas lock.
[0031] In summary, a number of convenient features result from the arrangement, namely:
a) flow optimization by monitoring fluid flow through a flow meter and controlling the downhole reciprocating pump stroke parameters; b) protect the sucker rod and downhole pump from excessive mechanical forces by monitoring the weight of the pump assembly; c) detection of common pumping problems; d) shutdown if a fault is detected in the downhole pump assembly such as an increase in pump assembly weight; e) shutdown if a fault is detected in a reduction in pump assembly weight; f) monitor electrical energy use and slow the motor speed if the motor is reaching the maximum configured energy limit; and g) control the acceleration and deceleration of the downhole pump assembly to keep stress to a minimum; h) Controller could be programmed to provide a dynamometer card to enhance well optimization. i) Up to the minute production will be flow tested to ensure downhole reciprocating pump remains free of any cavitation and eliminate what is known in the art as “fluid pounding” or “fluid hammer”.
[0041] Although embodiments of the invention have been described above, it is not limited thereto and it will be apparent to those skilled in the art that numerous modifications form part of the present invention insofar as they do not depart from the spirit, nature and scope of the claimed and described invention.
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An electromagnetic ram for use in artificially lifting fluid from a well and in particular an oil well. The disclosure also teaches a method and system employing the ram. The use obviates existing systems used today in terms of cost, environmental concerns, optimized mechanical efficiencies and maximizing overall production of wells on a case by case basis.
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REFERENCE TO RELATED APPLICATIONS
This application claims priority to provisional application Serial No. 60/336,002, filed Nov. 1, 2001, entitled “Devices, Methods and Assemblies for Intervertebral Disc Repair and Regeneration”, and provisional application Serial No. 60/336,332, entitled “Pretreatment of Cartilaginous Endplates Prior to Treatment of the Intervertebral Disc with an Injectable Biomaterial”, filed on Nov. 2, 2001, and the disclosure of which are both incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates generally to the treatment of spinal diseases and injuries, and more specifically to the restoration of the spinal disc following surgical treatment. The invention contemplates devices and methods for restoring the normal intervertebral disc space height and for facilitating the introduction of biomaterials for use in the repair and restoration of the intervertebral disc.
The intervertebral disc is divided into two distinct regions: the nucleus pulposus and the annulus fibrosus. The nucleus lies at the center of the disc and is surrounded and contained by the annulus. The annulus contains collagen fibers that form concentric lamellae that surround the nucleus and insert into the endplates of the adjacent vertebral bodies to form a reinforced structure. Cartilaginous endplates are located at the interface between the disc and the adjacent vertebral bodies.
The intervertebral disc is the largest avascular structure in the body. The disc receives nutrients and expels waste by diffusion through the adjacent vascularized endplates. The hygroscopic nature of the proteoglycan matrix of the nucleus operates to generate high intra-nuclear pressure. As the water content in the disc increases, the intra-nuclear pressure increases and the nucleus swells to increase the height of the disc. This swelling places the fibers of the annulus in tension. A normal disc has a height of about 10–15 mm.
There are many causes of disruption or degeneration of the intervertebral disc that can be generally categorized as mechanical, genetic and biochemical. Mechanical damage includes herniation in which a portion of the nucleus pulposus projects through a fissure or tear in the annulus fibrosus. Genetic and biochemical causes can result in changes in the extracellular matrix pattern of the disc and a decrease in biosynthesis of extracellular matrix components by the cells of the disc. Degeneration is a progressive process that usually begins with a decrease in the ability of the extracellular matrix in the central nucleus pulposus to bind water due to reduced proteoglycan content. With a loss of water content, the nucleus becomes desiccated resulting in a decrease in internal disc hydraulic pressure, and ultimately to a loss of disc height. This loss of disc height can cause the annulus to buckle with non-tensile loading and the annular lamellae to delaminate, resulting in annular fissures. Herniation may then occur as rupture leads to protrusion of the nucleus.
Proper disc height is necessary to ensure proper functionality of the intervertebral disc and spinal column. The disc serves several functions, although its primary function is to facilitate mobility of the spine. In addition, the disc provides for load bearing, load transfer and shock absorption between vertebral levels. The weight of the person generates a compressive load on the discs, but this load is not uniform during typical bending movements. During forward flexion, the posterior annular fibers are stretched while the anterior fibers are compressed. In addition, a translocation of the nucleus occurs as the center of gravity of the nucleus shifts away from the center and towards the extended side.
Changes in disc height can have both local and global effects. On the local (or cellular, level) decreased disc height results in increased pressure in the nucleus, which can lead to a decrease in cell matrix synthesis and an increase in cell necrosis and apoptosis. In addition, increases in intra-discal pressure create an unfavorable environment for fluid transfer into the disc, which can cause a further decrease in disc height.
Decreased disc height also results in significant changes in the global mechanical stability of the spine. With decreasing height of the disc, the facet joints bear increasing loads and may undergo hypertrophy and degeneration, and may even act as a source of pain over time. Decreased stiffness of the spinal column and increased range of motion resulting from loss of disc height can lead to further instability of the spine, as well as back pain. The outer annulus fibrosus is designed to provide stability under tensile loading, and a well-hydrated nucleus maintains sufficient disc height to keep the annulus fibers properly tensioned. With decreases in disc height, the annular fibers are no longer able to provide the same degree of stability, resulting in abnormal joint motion. This excessive motion can manifest itself in abnormal muscle, ligament and tendon loading, which can ultimately be a source of back pain.
Radicular pain may result from a decrease in foraminal volume caused by decreased disc height. Specifically, as disc height decreases, the volume of the foraminal canal, through which the spinal nerve roots pass, decreases. This decrease may lead to spinal nerve impingement, with associated radiating pain and dysfunction
Finally, adjacent segment loading increases as the disc height decreases at a given level. The discs that must bear additional loading are now susceptible to accelerated degeneration and compromise, which may eventually propagate along the destabilized spinal column.
In spite of all of these detriments that accompany decreases in disc height, where the change in disc height is gradual many of the ill effects may be “tolerable” to the spine and may allow time for the spinal system to adapt to the gradual changes. However, the sudden decrease in disc volume caused by the surgical removal of the disc or disc nucleus may heighten the local and global problems noted above. Many disc defects are treated through a surgical procedure, such as a discectomy in which the nucleus pulposus material is removed. During a total discectomy, a substantial amount (and usually all) of the volume of the nucleus pulposus is removed and immediate loss of disc height and volume can result. Even with a partial discectomy, loss of disc height can ensue. Discectomy alone is the most common spinal surgical treatment, frequently used to treat radicular pain resulting from nerve impingement by disc bulge or disc fragments contacting the spinal neural structures.
In another common spinal procedure, the discectomy may be followed by an implant procedure in which a prosthesis is introduced into the cavity left in the disc space when the nucleus material is removed. Thus far, the most prominent prosthesis is a mechanical device or a “cage” that is sized to restore the proper disc height and is configured for fixation between adjacent vertebrae. These mechanical solutions take on a variety of forms, including solid kidney-shaped implants, hollow blocks filled with bone growth material, push-in implants and threaded cylindrical cages.
In more recent years, injectable biomaterials have been more widely considered as an augment to a discectomy. As early as 1962, Alf Nachemson suggested the injection of room temperature vulcanizing silicone into a degenerated disc using an ordinary syringe. In 1974, Lemaire and others reported on the clinical experience of Schulman with an in situ polymerizable disc prosthesis. Since then, many injectable biomaterials or scaffolds have been developed as a substitute for the disc nucleus pulposus, such as hyaluronic acid, fibrin glue, alginate, elastin-like polypeptides, collagen type I gel and others. A number of patents have issued concerning various injectable biomaterials including: cross-linkable silk elastin copolymer discussed in U.S. Pat. No. 6,423,333 (Stedronsky et al.); U.S. Pat. No. 6,380,154 (Capello et al.); U.S. Pat. No. 6,355,776 (Ferrari et al.); U.S. Pat. No. 6,258,872 (Stedronsky et al.); U.S. Pat. No. 6,184,348 (Ferrari et al.); U.S. Pat. No. 6,140,072 (Ferrari et al.); U.S. Pat. No. 6,033,654 (Stedronsky et al.); U.S. Pat. No. 6,018,030 (Ferrari et al.); U.S. Pat. No. 6,015,474 (Stedronsky); U.S. Pat. No. 5,830,713 (Ferrari et al.); U.S. Pat. No. 5,817,303 (Stedronsky et al.); U.S. Pat. No. 5,808,012 (Donofrio et al.); U.S. Pat. No. 5,773,577 (Capello); U.S. Pat. No. 5,773,249 (Capello et al.); U.S. Pat. No. 5,770,697 (Ferrari et al.); U.S. Pat. No. 5,760,004 (Stedronsky); U.S. Pat. No. 5,723,588 (Donofrio); U.S. Pat. No. 5,641,648 (Ferrari); and U.S. Pat. No. 5,235,041 (Capello et al.); protein hydrogel described in U.S. Pat. No. 5,318,524 (Morse et al.); U.S. Pat. No. 5,259,971 (Morse et al.): U.S. Pat. No. 5,219,328 (Morse et al.); and U.S. Pat. No. 5,030,215; polyurethane-filled balloons discussed in No. 60/004,710 (Felt et al.); U.S. Pat. No. 6,306,177 (Felt et al.); U.S. Pat. No. 6,248,131 (Felt et al.) and U.S. Pat. No. 6,224,630 (Bao et al.); collagen-PEG set forth in U.S. Pat. No. 6,428,978 (Olsen et al.); U.S. Pat. No. 6,413,742 (Olsen et al.); U.S. Pat. No. 6,323,278 (Rhee et al.); U.S. Pat. No. 6,312,725 (Wallace et al.); U.S. Pat. No. 6,277,394 (Sierra); U.S. Pat. No. 6,166,130 (Rhee et al.); U.S. Pat. No. 6,165,489 (Berg et al.); U.S. Pat. No. 6,123,687 (Simonyi et al.); U.S. Pat. No. 6,111,165 (Berg); U.S. Pat. No. 6,110,484 (Sierra); U.S. Pat. No. 6,096,309 (Prior et al.); U.S. Pat. No. 6,051,648 (Rhee et al.); U.S. Pat. No. 5,997,811 (Esposito et al.); U.S. Pat. No. 5,962,648 (Berg); U.S. Pat. No. 5,936,035 (Rhee et al.); and U.S. Pat. No. 5,874,500 (Rhee et al.); chitosan in U.S. Pat. No. 6,344,488 to Chenite et al.; a variety of polymers discussed in U.S. Pat. No. 6,187,048 (Milner et al.; recombinant biomaterials in No. 60/038,150 (Urry); U.S. Pat. No. 6,004,782 (Daniell et al.); U.S. Pat. No. 5,064,430 (Urry); U.S. Pat. No. 4,898,962 (Urry); U.S. Pat. No. 4,870,055 (Urry); U.S. Pat. No. 4,783,523 (Urry et al.); U.S. Pat. No. 4,783,523 (Urry et al.); U.S. Pat. No. 4,589,882 (Urry); U.S. Pat. No. 4,500,700 (Urry); U.S. Pat. No. 4,474,851 (Urry); U.S. Pat. No. 4,187,852 (Urry et al.); and U.S. Pat. No. 4,132,746 (Urry et al.); and annulus repair materials described in U.S. Pat. No. 6,428,576 to Haldimann.
These references disclose biomaterials or injectable scaffolds that have one or more properties that are important to disc replacement, including strong mechanical strength, promotion of tissue formation, biodegradability, biocompatibility, sterilizability, minimal curing or setting time, optimum curing temperature, and low viscosity for easy introduction into the disc space. The scaffold must exhibit the necessary mechanical properties as well as provide physical support. It is also important that the scaffold be able to withstand the large number of loading cycles experienced by the spine. The biocompatibility of the material is of utmost importance. Neither the initial material nor any of its degradation products should elicit an unresolved immune or toxicological response, demonstrate immunogenicity, or express cytoxicity.
Generally, the above-mentioned biomaterials are injected as viscous fluids and then cured in situ. Curing methods include thermosensitive cross-linking, photopolymerization, or the addition of a solidifying or cross-linking agent. The setting time of the material is important—it should be long enough to allow for accurate placement of the biomaterial during the procedure yet should be short enough so as not to prolong the length of the surgical procedure. If the material experiences a temperature change while hardening, the increase in temperature should be small and the heat generated should not damage the surrounding tissue. The viscosity or fluidity of the material should balance the need for the substance to remain at the site of its introduction into the disc, with the ability of the surgeon to manipulate its placement, and with the need to assure complete filling of the intradiscal space or voids.
Regardless of the injectable scaffold material used, it is critical that the completed procedure restore the disc height. It is thus important that the proper disc height be maintained while the biomaterial is being introduced into the intradiscal space. Ideally, the disc height will be restored to levels equivalent to the heights of the adjacent discs and representative of a normal spinal disc height for the particular patient.
However, if disc height is not re-established prior to introduction of the scaffold material, it will become impossible to replace the lost disc volume and at least restore the disc height to what it was prior to the discectomy. Failure to hold a proper disc height as the biomaterial is introduced and cured in situ can eventually lead to a collapse of the disc space. This phenomenon is illustrated by a comparison of a proper intervertebral disc height in FIG. 1 a versus a reduced disc height in FIG. 1 b . The reduced disc height of FIG. 1 b will ordinarily follow a substantially complete discectomy, unless the adjacent vertebrae are distracted. The patient can be placed in certain positions that tend to open the disc space, particularly at the posterior side of the disc D. However, it has been found that even with hyper-flexion of the spine the intervertebral space does not approach its proper volume, and consequently the intervertebral height does not approach the proper disc height of FIG. 1 a.
Prior procedures for the implantation of a curable disc prosthesis have relied upon the physical positioning of the patient or upon pressurized injection of the biomaterial to obtain some degree of distraction. However, these prior approaches do not achieve repeatable restoration of proper anatomical disc height, either during the surgical procedure or afterwards. Consequently, there remains a need for a method and system that provides a high degree of assurance that a proper disc height will be established and maintained when the intervertebral disc is replaced or augmented by an injectable biomaterial.
SUMMARY OF THE INVENTION
In order to address the unresolved needs of prior spinal procedures, the present invention contemplates a method for injecting a fluent material into a disc space. The method includes the steps of creating a portal in the annulus pulposus in communication with the intradiscal space and impacting a cannulated distractor into the portal. In accordance with one feature of the invention, the distractor is configured to distract the vertebrae adjacent the intradiscal space and to establish a disc space height between the adjacent vertebrae. The method includes the further step of introducing the fluent material into the intradiscal space through a lumen of the cannulated distractor while the distractor maintains the established disc space height.
In certain embodiments, the inventive method includes the step of performing a discectomy after the portal is created, in which the discectomy forms a cavity within the intradiscal space. In this embodiment, the step of impacting a cannulated distractor includes positioning the distractor so that the lumen is in communication with the cavity, and the step of introducing the fluid includes introducing the fluid into the cavity. The discectomy can be a total discectomy in which substantially all of the nucleus pulposus is removed from the disc space.
In a further feature of the invention, the fluent material is a curable biomaterial that is particularly suited as a disc replacement or augmentation material. In this case, the step of introducing the fluent material can include maintaining the distractor in its impacted position until the biomaterial cures in situ. In other words, the cannulated distractor maintains the adjacent vertebrae in their distracted position until the biomaterial has set. In this way, the proper disc height can be maintained and retained once the biomaterial has set and the distractor removed.
In certain embodiments, the fluent material can be introduced into the disc cavity under pressure. In another feature of the invention that is particularly useful where the fluent material is under pressure, the cannulated distractor is configured to seal the portal when the distractor is impacted therein. In some embodiments, the distractor has a portion sized to substantially block or seal the annular portal. In other embodiments, the distractor includes a sealing feature that bears against the adjacent vertebrae and/or the annulus fibrosus material surrounding the portal. The sealing feature can be integral with the cannulated distractor or can include a separate component, such as a seal ring, mounted on the distractor.
In still another aspect of the invention, and again one that is particularly suited where the fluent material is under pressure, a vent is provided in the cannulated distractor. Thus, the fluent material can be introduced into the intradiscal space until the fluent material seeps from the vent. Thus, the vent can provide an immediate indication that the disc cavity is full.
In some embodiments of the invention, the cannulated distractor is engaged to a fluid injector apparatus. This apparatus can be in a variety of forms, including a pump, a syringe and a gravity feed system.
In other embodiments, the step of introducing the fluent material includes extending an tube through the lumen in the cannulated distractor, with the tube fluidly connected to a source of the fluent material. The tube can be manipulated through the distractor lumen to direct the fluent material to specific locations within the disc cavity. For instance, the tube can be moved through a seeping motion so that the fluent material is completely dispersed throughout the disc space. At the same time, the tube can be gradually withdrawn from the distractor lumen as the fluent material nears the lumen opening.
In a preferred embodiment, a seal is provided between the tube and the lumen. A vent can then be provided separate from the lumen so that the fluent material can seep from the vent to indicate that the cavity is full.
In another embodiment of the invention, a device for injecting a fluent material into a disc space comprises a distraction member having opposite surfaces configured to distract adjacent vertebrae to the disc space. The distraction member has a proximal end and a distal end portion, in which at least the distal end portion configured to be disposed within the disc space. The distraction member further defines a fluid passageway between the proximal end and the distal end portion, the passageway having an opening at the proximal end and at the distal end portion. In some embodiments, the distraction member can include a fitting associated with the proximal end of the distraction member for fluidly connecting the distraction member to a source of the fluent material.
In accordance with another aspect of the invention, the device further comprises an elongated cannula defining a lumen therethrough. The cannula can have a first fitting at one end thereof configured for fluid tight connection to the fitting of the distraction member, and a second fitting at an opposite end thereof configured for fluid connection to a source of the fluent material. In specific embodiments, the distraction member is integral with the cannula and the second fitting is the fitting associated with the proximal end of the distraction member. In other embodiments, the distraction member is removable from the cannula.
In a preferred embodiment, at least the distal end portion of the distraction member is bullet-shaped. In alternative embodiments, the distal end portion of is wedge-shaped with opposite substantially flat sides, cruciate-shaped, I-beam shaped and C-shaped.
The fluid passageway of the distraction member includes a central lumen with a number of openings communicating therewith. The openings can be arranged in the variously shaped distal end portion to direct the fluent material to appropriate locations within the disc cavity. The distraction member can also define a vent opening separate from the fluid passageway. In certain embodiments, the fluid passageway can be in the form of interconnected interstices throughout the distraction member material.
In the preferred embodiment, the distraction member is formed of a biocompatible material, such as stainless steel or titanium. In alternative embodiments, other biocompatible materials can be used, such as polymeric materials and even bioresorbable materials. In accordance with one aspect, the distraction member is configured to be removed from the disc space once the fluent material has been introduced into the disc cavity, and has cured, if necessary. In other aspects, the distraction member is configured to remain within the disc space, most preferably if the member is formed of a bioresorbable material.
The distraction member can include a sealing element associated with a proximal portion of the distal end portion, wherein the sealing element is configured to provide a substantially fluid-tight seal within the disc space. The sealing element can include a number of seal rings disposed on the distal end portion. The seal rings can be integral with the distal end portion or can be elastomeric rings mounted on the distal end portion, for example.
It is one object of the invention to provide a system and device for maintaining and enforcing a proper intervertebral spacing or disc height when a disc prosthesis is introduced into a cavity within the intradiscal space. Another object is achieved by features of the invention that allow introduction of a fluent material into the disc space while maintaining the adjacent vertebrae distracted and the disc height intact.
Other objects and certain benefits of the invention can be discerned from the following written description and accompanying figures.
DESCRIPTION OF THE FIGURES
FIGS. 1 a – 1 b are lateral views of a disc and adjacent vertebrae showing a proper intervertebral disc height ( FIG. 1 a ) and a reduced disc height ( FIG. 1 b ) following a substantially complete discectomy.
FIG. 2 is a lateral view a disc and adjacent vertebrae with a guide wire placed in accordance with one aspect of the present invention.
FIG. 3 is a sagittal view of the disc space shown in FIG. 2 with a trephine forming a portal in the annulus fibrosus of the disc.
FIG. 4 is a sagittal view of the disc space shown in FIG. 3 with a tissue extraction device positioned within the nucleus pulposus of the disc.
FIG. 5 is a sagittal view of the disc space shown in FIGS. 2–4 with a cannulated distractor in accordance with one embodiment of the present invention.
FIG. 6 is a side view of a cannulated distractor in accordance with one embodiment of the present invention.
FIG. 7 is a lateral view of the disc space shown in FIGS. 2–5 with the cannulated distractor of FIG. 6 positioned within the disc space.
FIG. 8 is a perspective view of a distraction tip forming part of the cannulated distractor shown in FIGS. 6 and 7 .
FIG. 9 is a perspective view of a distraction tip according an alternative embodiment of the invention.
FIG. 10 is a side view of an injector apparatus for use in one embodiment of the invention.
FIG. 11 is lateral view of a disc space with a cannulated distractor in accordance with a further embodiment of the invention.
FIG. 12 is a cross-sectional view of a cruciate distraction tip according to one embodiment of the cannulated distractor of the present invention.
FIG. 13 is a cross-sectional view of an I-beam shaped distraction tip according to another embodiment of the cannulated distractor of the present invention.
FIG. 14 is a cross-sectional view of a C-shaped distraction tip according to a further embodiment of the cannulated distractor of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains.
The present invention contemplates a procedure and device that is implemented following removal of a portion or substantially all of the natural nucleus pulposus of an intervertebral disc. One important purpose of the invention is to maintain the proper disc height during the introduction of a biomaterial that is intended to replace the removed nuclear material. Removal of disc material can be accomplished chemically, such as by the use of Chymopapain. However, the more common approach is by discectomy, which can be conducted as an open surgical procedure, via microscope-assisted visualization, or through percutaneous access.
A typical percutaneous discectomy procedure is illustrated in FIGS. 2–4 . In the first step, a guide wire G is directed into an affected disc D between two vertebrae, such as the L 2 and L 3 lumbar vertebrae. As shown in FIG. 3 , the guide wire G penetrates the annulus fibrosus A and the nucleus pulposus N, and it preferably anchored at opposite sides of the annulus A. The guide wire G can be positioned and placed under indirect vision, such as fluoroscopy, or stereotactically, or using other known procedures for properly orienting the guide wire within the spinal disc D. The procedure shown in the figures utilizes a posterior approach, which is preferable for implementation of the present invention. Of course, other approaches may be utilized for the discectomy in accordance with known surgical procedures. In addition, the access location may be dictated by the location of a fissure or herniation of the disc.
A trephine T is advanced over the guide wire and driven through the annulus A, thereby forming a portal into the disc nucleus. As shown in FIG. 4 , a tissue removal device R can be advanced through the trephine T or through a working channel cannula aligned with the disc portal. The device R can then be used to remove all or part of the nucleus N of the disc D. As depicted in dashed lines in FIG. 4 , a second trephine T′ can be used to create a second annular portal to facilitate complete removal of the nucleus pulposus of the disc. The tissue removal device R can be of a variety of types, such as a rongeur, tissue morcellator, rotary and/or reciprocating vacuum-assisted cutter, and even a chemical introducer to direct a chemical such as Chymopapain into the nuclear space. Removal of the nucleus leaves a cavity C (see FIG. 5 ) surrounded by the substantially intact annulus A
The present invention contemplates the introduction of a biomaterial into the disc cavity C that is capable or restoring disc height and preferably substantially normal disc function. For instance, any of the biomaterials discussed above can fill the newly formed cavity. In accordance with the preferred embodiment, the biomaterial is a fluid with an appropriate flowability and/or viscosity. In particular, the biomaterial must have sufficient flowability to permit relatively easy introduction into the disc cavity C, but with sufficient viscosity to hold its shape within the disc. Since the material being used to fill the disc cavity C is a fluid, the present invention provides means for holding a proper disc height as the material flows into the cavity, to thereby ensure that the cavity is filled—i.e., that the volume of implant biomaterial is the same as the volume of nucleus pulposus removed in the discectomy. Moreover, the methods and devices of the invention provide a means for maintaining the cavity volume as the biomaterial transforms to its solid state.
Thus, in accordance with one embodiment of the invention, a cannulated distractor 10 is provided as shown in FIGS. 5–8 . The distractor 10 includes a distal end 12 that extends into the disc cavity C and a proximal end 14 that is configured to engage a device for injecting the biomaterial into the disc space. The distractor 10 includes a cannula 11 that terminates in a distraction tip 18 at the distal end of the device. A lumen 16 is defined along the entire length of the device from the proximal end 14 to the and through the distraction tip 18 . The distraction tip 18 is sized to extend through the portal formed in the disc annulus A (see FIG. 3 ). The distractor 10 can include a shoulder 20 proximal to the distraction tip 18 , in which the shoulder is sized to prevent passage through the annular portal. The shoulder 20 can operate to limit the distance that the distraction tip 18 extends into the disc cavity C. The distractor 10 can be provided with means for temporarily fixing the distractor in position or supporting the distractor on the adjacent vertebrae.
As shown in FIG. 7 , the distraction tip 18 is intended to be inserted through the annular portal and is configured to restore the appropriate intradiscal height in the cavity C. Thus, in one embodiment, the distraction tip 18 can include a tapered leading portion 24 . This leading portion 24 can be introduced into the cavity C and as the tip is advanced further into the cavity the leading portion will gradually distract the adjacent vertebrae as the leading portion 24 bears against the disc endplates E. In a specific embodiment, the tapered portion 24 can be substantially bullet-shaped, as shown in FIG. 8 . With this configuration, the distraction tip 18 can have any rotational orientation when the tip is inserted through the annular portal.
Alternatively, the distraction tip can be configured like the tip 40 shown in FIG. 9 . With this embodiment, the tip includes opposing generally flat sides 50 and intermediate edges 52 of the wedge portion 42 . The tip 40 can be introduced into the disc space with the flat sides 50 of the wedge facing the disc endplates E. Once the tip is fully within the disc cavity C, the tip can be rotated so that the edges 52 contact and distract the endplates. The edges 52 themselves can be wedge-shaped, having a greater width at their proximal end than at their distal end.
Returning to FIGS. 6–8 , in accordance with one feature of the invention, the distraction tip 18 includes a number of side orifices 30 and an end orifice 32 that all communicate with the central lumen 16 . As depicted in FIG. 7 , the orifices 30 , 32 provide an exit path for fluid injected through the lumen 16 . Preferably, the orifices are oriented to be unobstructed by the vertebral endplates E. The distraction tip 40 shown in FIG. 9 is also provided with side orifices 46 in the flat sides 50 and an end orifice 48 . With this embodiment, the edges 52 need not include orifice(s) because the edges will be occluded by contact the endplates.
Since fluid is intended for introduction through the distraction tip 30 , it is preferable that some feature be provided to ensure a substantially fluid-tight seal at the entrance to the disc cavity C through the annular portal. Thus, in one embodiment of the invention, the distraction tip 30 can include annular rings 26 that are intended to bear against the disc endplates E and/or the disc annulus A in a sealing relationship. The rings 26 can be integral with the distraction tip 30 , or can be separate components mounted on the distraction tip, such as in the form of elastomeric seal rings. The seal rings can be mounted within annular grooves formed in the distraction tip.
The distractor 10 includes a fitting 36 defined at the proximal end 14 of the cannula 11 . The fitting 36 provides means for making a fluid-tight connection with a device adapted to inject the biomaterial into the disc. One exemplary device 70 is shown in FIG. 10 . The injector 70 includes a chamber 72 for storage of the biomaterial. In some cases, the chamber 72 may constitute multiple chambers where the injectable biomaterial is obtained by mixing various constituent materials. For instance, certain materials may be curable in situ and may require combining a curing agent with a base material. To facilitate mixing of the biomaterial constituents, the injector 70 can include a mixing chamber 74 . A manual control 76 can be provided that forces the contents of the chamber 72 into the mixing chamber 74 . Alternatively, the injector 70 can incorporate a mechanism that drives the fluid from the injector under pressure, such as a syringe or a pump.
The injector 70 includes a fitting 80 that is configured for fluid-tight engagement with the fitting 36 of the cannulated distractor 10 . In a preferred embodiment, the two fittings 36 , 80 represent mating components of a LUER® fitting. The injector can include a nozzle 78 that extends into the cannula 11 , or more specifically into the lumen 16 , when the injector 70 is engaged to the cannulated distractor. A grip 82 can be provided to allow manual stabilization of the injector.
As explained above, the cannulated distractor 10 of the present invention may be utilized after a discectomy procedure. For purposes of illustration, it has been assumed that a total discectomy has been performed in which substantially all of the nucleus pulposus has been removed, leaving a disc cavity C as shown in FIG. 5 . Of course, the principles of the invention can apply equally well where only a portion of the disc nucleus has been removed through a partial discectomy. If a bilateral approach has been used (as represented by the first and second trephines T and T′), one of the annular portals can be sealed with a material compatible to the disc annulus fibrosus. When the nucleus has been cleared, the guide wire G can be repositioned within the disc D, again preferably using known guidance and positioning instruments and techniques. The cannulated distractor 10 can then be advanced over the guide wire until the distraction tip 18 is properly situated within the nuclear cavity C. Preferably, the proper depth for the distraction tip 18 can be determined by contact of the shoulder 20 with the outer annulus A, or by contact of an associated depth feature with the adjacent vertebral bodies.
With the distraction tip 18 , the tapered portion 24 gradually separates the adjacent vertebral endplates E as the distraction tip is driven further into the disc space. A mallet, impactor or other suitable driver can be used to push the tapered portion 24 into position against the natural tension of the disc annulus. It is understood that the goal of this step is to fully distract the intervertebral space to a proper disc height for the particular spinal level. For instance, for the L 2 –L 3 disc space, the appropriate disc height may be 13–15 mm, so that the distraction tip is positioned within the cavity C to achieve this amount of distraction. As shown in FIG. 5 , preferably only one cannulated distractor 10 is utilized, since the distraction tip 18 necessarily occupies a certain portion of the volume of the cavity C. However, a second cannulated distractor and associated distraction tip may be necessary (such as through a second annular portal as shown in FIG. 4 ) to achieve the proper disc height.
It should be understood that the process thus far would be similar for the distraction tip 40 . However, unlike the tapered distraction tip 18 , the distraction tip 40 requires an additional step to distract the disc space. Specifically, the distraction tip 40 is initially inserted with its flat sides 50 facing the endplates E. The tip must then be rotated until the edges 52 bear against and support the endplates. The flat sides 50 can include an angled transition to the edges, or the edges 52 can be rounded to facilitate the distraction as the distraction tip is rotated in situ.
When the distraction tip, such as tip 10 , is inserted to its proper depth within the disc cavity C, the annular portal is sealed, whether by contact with the shoulder 20 , or by engagement of the rings 26 with the endplates E or the interior of the annular portal. At this point, the biomaterial fluid can be injected into the cannulated distractor, and specifically into the lumen 16 . To accomplish this step, the injector, such as injector 70 , can be mated with the fitting 36 at the proximal end 14 of the cannulated distractor. Optimally, the guide wire G is removed and the fitting 80 of the injector engages the fitting 36 . The nozzle 78 extends into the lumen 16 . The nozzle can be sized so that the exit end of the nozzle is near or within the distraction tip 18 . At this point, the injector 70 can be actuated in accordance with its construction so that the biomaterial fluid is displaced from the injector and into the lumen 16 . The biomaterial exits through the orifices 30 , 32 in the distraction tip 18 to fill the cavity C. The orifices 30 , 32 are preferably positioned and sized to achieve complete and rapid dispersion of the biomaterial throughout the cavity. Again, the goal of this step of the process is to completely fill the entire volume of the cavity, or to replace the entire volume of nucleus pulposus removed during the discectomy. Where the fluid biomaterial is an in situ curable or settable material, time may also be of the essence to ensure a homogeneous mass once the material is completely cured.
It should be apparent that the distraction tip 18 , 40 maintains the proper disc height while the biomaterial is injected. The tip can be retained in position until the injected material cures or sets. Once the material has sufficiently cured, the distraction tip 18 , 40 can be removed. Since the distraction tip occupies a certain volume, additional biomaterial can be injected through the tip as it is being withdrawn, if required, thereby filling the gap left by the tip.
In certain embodiments, the distraction tip 18 can be a modular and removable from the cannula 11 , as shown in FIG. 8 . Thus, the tip 18 and cannula 11 can be provided with a removable mating element 19 , such as a press-fit (as shown in FIG. 9 ) or a threaded or LUER® type fitting (not shown) as would occur to a person of skill in this art. A removable distraction tip can serve several purposes. In one purpose, the injected biomaterial may require a lengthy curing time. While the material is curing, it is of course necessary to keep the distraction tip in position to maintain the proper disc height. However, it may not be necessary to retain the other components of the system in position, such as the injector 70 and cannula 11 . A modular distraction tip allows the cannula 11 to be removed while the tip remains in position, acting as a disc spacer while the biomaterial cures.
In another purpose, a number of differently sized tips can be mounted to a commonly sized cannula. Each patient has a different spinal anatomy, which means the appropriate disc height at a given spinal level may vary between patients. Moreover, the disc height can vary with spinal level. Thus, a plurality of differently sized distraction tips 18 can be provided to ensure proper spacing across the spinal disc D.
Another purpose behind a removable distraction tip 18 is achieved by embodiments in which the tip is formed of a biocompatible material that allows the tip to remain resident within the disc space. In this embodiment, the distraction tip material must be compatible with the biomaterial used to replace the natural nucleus. For instance, if the biomaterial is only intended to restore disc height, but not the natural biomechanical properties of the natural nucleus, then the material of the distraction tip 18 may provide a generally rigid scaffolding. On the other hand, and most preferably, the injected biomaterial is intended to emulate the biomechanical characteristics of the disc to allow the spinal segment to operate as close to a normal spinal segment as possible. In this instance, a rigid scaffold would of course frustrate the normal flexion, compression and torsional responses of the disc. Thus, the distraction tip 18 in embodiments where the tip is left in situ can be formed of a biodegradable or bioresorbable material that absorbs into the matrix of the cured biomaterial forming the disc nucleus prosthesis.
Whether the distraction tip is removed or remains within the disc space, it is preferable that the tip occupy as little volume as possible. On the other hand, the distraction tip must be sufficiently strong to sustain the compression loads that it will face while distracting adjacent vertebrae and holding the disc space height while the injected biomaterial cures. In the specific embodiments shown in FIGS. 5 and 7 , the distraction tip 18 is shown traversing across a substantial portion of the nuclear cavity C. Alternatively, the distraction tip can have a reduced length from the shoulder 20 so that the tip extends only partially into the cavity. Distraction of the disc space can be abetted by certain positions of the patient on the operating table where, for instance, the anterior aspect of the disc space is naturally distracted by the position of the spine. Proper distraction of the disc space may be better accommodated by an anterior approach, rather than the posterior approach shown in FIGS. 5 and 7 .
In alternative embodiments, the distraction tip can assume a wide range of geometries, some dictated by the annular portal formed during the discectomy procedure. In the embodiment of FIGS. 5–8 , a circular annular portal has bee created and a circular distraction tip 18 utilized to seal the portal. In some cases, a planar or wedge-shaped distraction tip, similar to the tip 40 shown in FIG. 9 , can be utilized where the opening through the annulus has an area greater than the tip itself. In these cases, the extra space between the tip and the interior surface of the portal can provide an opening for a direct visualization instrument, or some other appropriate instrument. Preferably, this approach is better suited where the biomaterial is not injected under pressure, such as cases where a gravity feed is employed (see FIG. 11 and associated discussion below).
In other cases, surgeons perform the discectomy through rectangular or cruciate portals in the disc annulus. A complementary shaped distraction tip can be utilized to conform to and fill the annular portal. For instance, the distraction tip can assume the configuration shown in FIGS. 12–14 . A cruciate-shaped tip 55 is shown in FIG. 12 with a central lumen 56 communicating with a number of openings 56 . It is understood that the arms of the cruciate-shaped tip can have a thinner cross-section than shown in the figure, provided they are sufficiently strong to support the adjacent vertebrae in their proper distracted position. Likewise, the openings 56 can be distributed in a variety of patterns through the hub and legs of the cruciate shape.
An I-beam distraction tip 60 is shown in FIG. 13 having a central lumen 61 communicating with a number of openings 62 . The distraction tip 63 in FIG. 14 has a C shape and includes a lumen 64 and openings 65 . These two beam configurations provide sufficient support for the necessary distraction. Again, the thickness of the arms of the beams can be reduced as necessary to minimize the cross-section of the distraction tip 60 , 63 .
Regardless of the overall configuration of the distraction tip, it is most preferable that volume of the tip within the nuclear cavity C be minimized. The bullet-shaped tip, such as tip 18 , may be less desirable from that standpoint, while the wedge type, such as tip 40 , may be preferable. In addition, regardless of the overall configuration, the distraction tip must communicate with the lumen 16 and must provide some means for discharge of the biomaterial fluid through the tip. In the illustrated embodiments, the distraction tips 18 , 40 include orifices 30 , 31 and 46 , 48 , respectively, that communicate with the corresponding lumens 16 , 44 . Alternatively, the distraction tips can be in the form of an open scaffold or skeletal framework. Again, the scaffold or framework must be sufficiently strong, especially in compression, to properly distract the disc space and hold the disc height for an appropriate length of time. In some embodiments, the distraction tip can be formed of a material having interconnected interstices, such as a porous material. The porous distraction tip can present a solid scaffold with a multitude of fluid flow paths through the material. The porous material can be a metal, such as a porous tantalum; however, a porous polymer, such as polylactic acid, is preferred so that the scaffold does not obscure visualization of the disc space after the procedure is completed.
In the procedures discussed above, the distraction tip has been described as providing an avenue for the injection of a biomaterial into the nuclear cavity C following a discectomy procedure. The distraction tips of the present invention serve equally well as a conduit for the introduction of other fluids to the disc space. For instance, the distraction tips can be used to inject a biomaterial such as the material disclosed in provisional application Ser. No. 60/336,332, entitled “Pretreatment of Cartilaginous Endplates Prior to Treatment of the Intervertebral Disc with an Injectable Biomaterial”, mentioned above, the disclosure of which is incorporated herein by reference. This provisional application discloses materials for the pretreatment of the disc endplates, for instance, to improve the biological functioning of a degenerative disc. The cannulated distractors of the present invention, such as distractor 10 , can be initially used for the disc pretreatments disclosed in the above-mentioned provisional application. Once the pretreatment has been completed, the cannulated distractor can then be used for the injection of the curable biomaterial.
Likewise, the present inventive cannulated distractor can be used for multiple fluid injections, including multiple injections to effect curing of a biomaterial within the nuclear cavity C. For instance, certain biomaterials may include a first constituent that is introduced into the disc space, followed by a second constituent or curing agent. The second constituent can initiate curing of the resulting composition.
An alternative embodiment of the invention is depicted in FIG. 11 . In this embodiment, a cannulated distractor 85 is provided that includes a generally frusto-conical distraction tip 86 and a shoulder 87 . The tip 86 is configured to act as a wedge to distract the disc space as the cannulated distractor 86 is impacted into the disc space. The shoulder 87 acts as a stop against the adjacent vertebral bodies to limit the distance that the tip is driven into the disc space. Preferably, the distraction tip 86 has a length from the shoulder 87 to its distal end that is sufficient to span the length of the portal in the disc annulus A, but is limited in its extent into the nuclear cavity C. With this embodiment, the distraction tip 86 does not displace any significant volume within the cavity C.
The cannulated distractor 85 defines a lumen 88 extending the entire length of the distractor. The lumen 88 is sized to receive an injection tube 94 therethrough. The injection tube 94 can include a fitting 96 for engaging an injection apparatus 98 . The fitting 96 can be of any suitable type, such as the LUER® fitting mentioned above. The injection apparatus can be similar to the injector 70 shown in FIG. 10 , or can assume a variety of configurations for the introduction of a fluid into the disc cavity. In one embodiment of the invention, the biomaterial fluid is introduced into the cavity by way of gravity feed. In this instance, the injection apparatus 98 can be simply in the form of a reservoir with an atmospheric vent to allow the biomaterial to flow downward into the disc space by gravity alone. Of course, the patient must be properly presented to accommodate gravity filling of the disc cavity C.
In this embodiment, the cannulated distractor 85 operates as a support or guide for the injection tube 94 . The tube 94 can be in the form of a smooth tipped, relatively large gauge needle that is sized to accommodate optimum flow of the biomaterial into the disc space. The tube 94 can be introduced through and gradually withdrawn from the cannulated distractor 85 (as indicated by the arrow in FIG. 11 ) as the biomaterial flows into the cavity C. In addition, the diameter of the tube 94 can be sized relative to the diameter of the lumen 88 so that the discharge opening 95 of the tube 94 can be pivoted with a sweeping motion through the cavity C. This aspect of this embodiment facilitates complete direct filling of the disc cavity C with the biomaterial. Where the cannulated distractor is used to introduce pre-treatment materials, such as those discussed above, this feature allows positioning of the discharge opening 95 to direct the pre-treatment materials where they are needed.
In certain embodiments, the lumen 88 can be provided with a seal 89 , which can be in the form of an elastomeric seal ring. The seal 89 can form a fluid-tight seal around the injection tube 94 , which can be especially important where the biomaterial is injected under pressure. In addition, the seal 89 can operate as a form of joint to support the injection tube 94 as the discharge opening 95 is manipulated within the disc cavity.
In another feature of the invention, the cannulated distractor can provide a vent for the discharge of excess biomaterial when the disc cavity C is full. The vent is particularly useful where the biomaterial is introduced under gravity feed. In one specific embodiment, a vent hole 92 is provided in the distractor 85 . When the disc cavity is full, the biomaterial will seep through the vent opening 92 , providing a direct visual indication that the cavity is full. Preferably, the vent opening 92 includes a tube that projects away from the cannulated distractor 85 to improve the visibility of the vent in situ. Alternatively, the vent can be formed by a difference in diameter between the injection tube 94 and the lumen 88 , and in the absence of the seal 89 .
The vent 92 is well-suited to procedures involving gravity feed of the biomaterial into the disc space. However, the vent can also be useful where the material is fed under pressure. For example, the vent 92 can be maintained initially open as the biomaterial is injected into the cavity C through the injection tube 94 . When the cavity is completely full, biomaterial will seep from the vent 92 . As this point, the vent can be closed and additional biomaterial injected into the disc space to increase the pressure within the cavity C. The seeping through the vent provides an immediate indication that the cavity is full, and can provide a starting point for the introduction of a calibrated amount of additional biomaterial to achieve a proper cavity pressure.
With each of the embodiments, once the biomaterial has cured and the cannulated distractor removed, the portal or portals in the disc annulus can be filled to prevent herniation of the newly formed prosthetic disc material. The annular portal can be sealed with any suitable material, such as fibrin glue, or a polymerizable material, or the like. The material used to seal the annulus should be sufficiently strong to remain intact as the intradiscal pressure is increased due to hydration or biomechanical movement of the spine.
In accordance with certain embodiments, the cannulated distractors, and particularly the distraction tips, described above can be formed a variety of biocompatible materials. As explained above the distraction tips must be sufficient strong to maintain proper distraction of the disc space until the biomaterial has been fully injected and cured, if necessary. In certain embodiments, the distraction tips are formed of a bio-compatible metal, such as stainless steel or titanium. In other embodiments, the distraction tips are formed of a polymer or plastic that is preferably radiolucent to permit visualization of the distraction tip in situ to verify the position of the component.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.
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A system and method is provided for maintaining a proper intervertebral disc height during the replacement or augmentation of the spinal disc. In one embodiment, a cannulated distractor is used to distract the adjacent vertebrae and maintain a proper disc space height. The cannulated distractor is fluidly connected to a source of fluent material for injection into the disc space. The distraction includes a distraction tip resident within the disc space that includes a central lumen and a number of openings communicating with the lumen to dispense the fluent material within the disc space.
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BACKGROUND
The present invention is an air conditioner drain line device that automatically engages a flapper that prevents the reverse flow of condensate water from entering a dwelling unit that shares a common drain line with multiple units, while at the same time allowing for quick and easy flushing of blockages in the drain line without causing water damage to the interior of the dwelling unit.
The inventor has been an air conditioning service technician for nine (9) years and has witnessed the flooding of dwelling units caused by blockages in the condensate drain line of multi-unit complexes that share a common drain line. The bottom unit of a multi-unit complex sharing a community drain line is particularly vulnerable to water damage caused from the reverse flow of condensate water when the trap at the bottom of the community drain line becomes blocked. After witnessing several units damaged by the back flow of water into the units because of a blockage in the community drain line and after hearing the frustrated cries of unit owners exclaim “there must be something that can be done about this” the inventor conceived the present invention.
Under normal conditions, a well maintained air conditioning unit produces a steady trickle of condensate water from the cooling coils of the unit. This flow is commonly referred to in the industry as the “two year old trickle” as the flow is similar to that which one can expect from a two year old urinating. Under normal conditions the trickle drains from the air conditioning unit, through the condensate drain line and exits the dwelling unit.
The condensate water often collects dust or other airborne debris that passes through the air conditioning unit and this combined with the microbial and bacterial growths that thrive in moist pipes often result in blockages in the drain lines. When the drain lines are blocked, water cannot drain properly and the only place the fluid produced from the air conditioning units can go is either up the community drain line or back into the dwelling unit. In order to remove the blockage in the drain line, the dwelling owner is required to call a service technician who must dismantle a portion of the air conditioning unit in order to remove the blockage.
In order to address this problem the inventor invented the present invention. The present invention comprises essentially a tubular pipe assembly with a plurality of openings forming an opening to let water in, an opening to let water out, an opening that can be used as a service port and a flapper assembly positioned between two of the openings thereby creating a valve that will only allow water to flow in one direction.
After the present invention is installed, a blockage in the community drain line would not result in damage to the unit which has the invention. Specifically, in the event that the trap in the community drain line was to clog and water was to back up the drain line, the flapper would engage and form a seal that would prevent any water from entering the dwelling unit. Moreover, if all the units who share a community drain line install the present invention, a blockage in drain line would cause water to back up and rise up the community drain line several stories high so that eventually the pressure of the water backed up in the community drain line would disengage the blockage with out having to call a service technician.
The service port in the present invention allows for easy access to a unidirectional pressure valve that can receive a pressurized gas or liquid that can be used to dislodge a blockage in the drain line. By positioning the service port in between the flapper assembly and the first opening of the tubular pipe assembly, when a pressurized gas or liquid is released through the service port, the flapper would engage and force the pressurized gas or liquid out the first opening of the tubular pipe assembly, down the community drain line and dislodge the blockage of the drain line.
An objective of the present invention is to provide a device that will prevent the backflow of condensate water into a dwelling unit and the associated property damage that would occur in the event of a blockage in the condensate drain line.
Another objective of the present invention is to provide a device that can automatically engage a self flushing mechanism in the event condensate water backs up several stories up a community drain line of a multi-unit complex where multiple units share a community drain line.
Another objective of the present invention is to provide a device with an easy to access service port.
Yet a further objective of the present invention is to provide a device that would allow a service technician to disengage a blockage in the community drain line without having to cut any drainage pipes.
Information relevant to attempts to address these problems can be found in U.S. Pat. Nos. 6,584,995 (hereinafter the “995 patent”) and 6,708,717 (hereinafter the “717 patent”. However, each one of these reference suffers from one or more of the following disadvantages. The 995 patent is only meant to prevent the back flow of air and therefore the flapper device would not prevent the back flow of condensate water. Specifically, the 995 patent does not include a flapper stopper and therefore the flapper may become stuck in the open position thereby failing to close and block the back flow of condensate water. The 995 patent also includes a protrusion connected to the interior surface of its tubular member that would prevent the trickle of the condensate water from exiting the drain line. The 717 patent does not disclose a valve assembly that can be automatically engaged upon the reverse flow of condensate water thereby requiring the manually engagement of the valve which defeats the preventative features of the present invention.
For the foregoing reasons there exists a need for an air conditioning drain device that automatically engages a flapper that prevents the reverse flow of condensate water from entering a dwelling unit that shares a common drain line with multiple units, while at the same time allowing for quick and easy flushing of blockages in the drain line without causing water damage to the interior of the dwelling unit.
SUMMARY
The present invention is an air conditioning drain device essentially comprising a tubular pipe assembly with a plurality of openings forming an opening to let water in, an opening to let water out and an opening that can be used as a service port as well as a flapper assembly that automatically engages a flapper that prevents the reverse flow of condensate water from entering a dwelling unit that shares a common drain line with multiple units, while at the same time allowing for quick and easy flushing of blockages in the drain line without causing water damage to the interior of the dwelling unit.
In the event the community drain line becomes clogged and water backs up the drain line, the flapper engages and forms a seal that prevents any water from entering the dwelling unit. The service port in the present invention allows for easy access to a unidirectional pressure valve that can receive a pressurized gas or liquid that can be used to dislodge a blockage in the drain line
DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims and drawings where:
FIG. 1 shows a partially broken away perspective view one embodiment of the present invention with the flapper in the open position;
FIG. 2 shows a partially broken away partial perspective view of one embodiment of the present invention with the flapper in the closed position;
FIG. 3 shows a side elevation view of one embodiment of the present invention with the flapper in the open position; and
FIG. 4 shows an alternative embodiment of the service port assembly.
DESCRIPTION
As shown in FIG. 1 , an air conditioner drain line device 100 comprising a Y shaped tubular pipe assembly 10 , a flapper assembly 20 , and a service port assembly 30 .
The Y shaped tubular pipe assembly 10 , has a first tubular member 11 , having an upper side and a lower side and an interior surface and an exterior surface, a first opening 12 ; a second tubular member 13 , having and upper side and a lower side and an interior surface and an exterior surface, a second opening 14 ; and a third tubular member 15 , having and upper side and a lower side and an interior surface and an exterior surface, and a third opening 16 .
The first tubular member 11 forms the base of the Y shaped tubular pipe assembly 10 . The second tubular member 13 and the third tubular member 15 form the arms of the Y shaped tubular pipe assembly 10 . First tubular member 11 is seamlessly joined to second tubular member 13 at a juncture point between first opening 12 and second opening 14 ; first tubular member 11 is seamlessly joined to third tubular member 15 at a juncture point between first opening 12 and third opening 16 ; and second tubular member 13 is seamlessly joined to third tubular member 15 at a juncture point between first opening 12 and third opening 16 .
An internal ridge 18 , having a top end and a lower end, is positioned along the interior surface of Y shaped tubular pipe assembly 10 . Internal ridge 18 diagonally connects first tubular member 11 and third tubular member 15 such that third tubular member 15 is at a higher elevation than first tubular member 11 . The Y shaped tubular pipe assembly 10 may be composed of materials known in the art with the characteristics and qualities of Poly Vinyl Chloride (PVC) piping.
The flapper assembly 20 further comprises an internal lip 22 fixedly attached to the internal surface of third tubular member 15 , whereby the internal lip 22 is diagonally positioned connecting the top end of the internal ridge 18 with a point along the interior surface of third tubular member 15 such that the internal lip 22 and the lower side of third tubular member 15 forms an obtuse angle. A flapper 24 is hingedly connected to the interior surface of the upper side of third tubular member 15 in between the juncture point of second tubular member 13 and third tubular member 15 and the third opening 16 of the Y shaped tubular pipe assembly 10 . Flapper stop 26 is fixedly attached to the interior surface of the upper side of third tubular member 15 in between internal lip 22 and the juncture point of second tubular member 13 and third tubular member 15 .
The service port assembly 30 , further comprises a plurality of unidirectional pressure valves 32 that are removably connected to the second opening 14 of the Y shaped tubular pipe assembly 10 .
The flapper stopper 26 might be positioned such that flapper 24 cannot pivot a full 180 degrees when fluid flows through third tubular member 15 towards first opening 12 .
The air conditioner drain line device 100 can be installed by connecting third opening 16 to the condensate drain line (not shown) of an existing air conditioning unit (not shown) and connecting first opening 12 to an existing drain line (not shown) that connects to a main community drain line (not shown).
In normal operation, condensate water, trickles from the coils (not shown) of the existing air conditioning unit (not shown) through the condensate drain line (not shown), through third tubular member 15 , over internal lip 22 , down internal ridge 18 , through first tubular member 11 and exits the air conditioner drain line device 100 through first opening 12 continuing to a main community drain line (not shown). If the condensate water flow is heavy enough to cause flapper 24 to pivot, the pivoting of flapper 24 would be limited by flapper stop 26 .
However, in the event a blockage occurs in the main community drain line (not shown), condensate water would then flow from the main community drain line (not shown), enter the air conditioner drain line device ( 100 ) through first opening 12 , continue through first tubular member 11 and engage flapper 24 . Once engaged, flapper 24 would form a seal with internal lip 22 , as seen in FIG. 2 thereby preventing the backflow of condensate water through third tubular member 15 and into the dwelling unit (not shown).
To dislodge a blockage in the main community drain line (not shown), a user connects a pressurized gas or liquid to the service port assembly 30 using the plurality of unidirectional pressure valves 32 . The pressurized gas or liquid flows from the service port 30 through second tubular member 13 , engaging the flapper 24 with the internal lip 22 , creating a seal preventing pressurized gas or liquid from flowing through third tubular member 15 thereby causing the pressurized gas or liquid to flow through first tubular member 11 , out first opening 12 and to the main community drain line (not pictured) to dislodge any blockage therein.
As seen in FIG. 3 and FIG. 4 , the service port assembly may have several embodiments, including a service port cap 30 a and an alternative means for receiving the pressurized gas or liquid 30 b.
An advantage of the present invention is that it provides a device that will prevent the backflow of condensate water into a dwelling unit and the associated property damage that would occur in the event of a blockage in the condensate drain line.
Another advantage of the present invention is that it provides a device that can provide for a self flushing mechanism in the event condensate water backs up several stories up a community drain line of a multiunit complex where multiple units share a community drain line.
Another advantage of the present invention is that it provides a device with an easy to access service port.
Yet still another advantage of the present invention is that it provides a device that allows a service technician to disengage a blockage in the community drain line without having to cut any drainage pipes.
Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and the scope of the claims should not be limited to the description of the preferred versions contained herein.
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An air conditioning drain device essentially comprising a tubular pipe assembly, a flapper assembly, and a service port assembly. The device automatically engages a flapper valve that prevents the reverse flow of condensate water from entering a dwelling unit that shares a common drain line with multiple units, while at the same time allowing for quick and easy flushing of blockages in the drain line without causing water damage to the interior of the dwelling unit.
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FIELD OF INVENTION
The present invention relates to antiblooming structures used within solid state image sensors, and more particularly, to the self aligned antiblooming structures.
BACKGROUND OF THE INVENTION
Blooming is a well known phenomenon that occurs in solid-state image sensors when the number of photocarriers generated by the incident radiation exceeds that of the storage capacity of the element, or pixel. These excess carriers then spill over, or "bloom", into adjacent photosites thereby degrading the integrity of the image. Many types of structures have been proposed in the past, such as U.S. Pat. No. 5,130,774 for example, which provide sinks for these excess carriers either laterally or vertically adjacent the photodetector elements. The advantages and disadvantages of both types have also been discussed.
It is important to maintain high quantum efficiency and charge capacity. Therefore, antiblooming structures should not take up so much space that there is a degradation in the quantum efficiency and charge capacity of the device. Many conventional antiblooming structures are inherently subject to level-to-level misalignment. The extra space taken up within these antiblooming structures to allow for the level-to-level misalignment can result in a reduction in performance of the sensor.
Some of the more recent disclosures are contained in U.S. Pat. No.: 5,349,215 issued to Anagnostopoulos et al. (hereinafter referred to as Anagnostopoulos); U.S. Pat. No. 5,130,774 issued to Stevens et al. (hereinafter referred to as Stevens); U.S. Pat. No. 5,118,631 issued to Dyck et al. (hereinafter referred to as Dyck); and U.S. Pat. No. 4,593,303 also issued to Dyck et al. (hereinafter referred to as Dyck "303"); describe relatively modern approaches at antiblooming structure design. Another important factor in the performance of these antiblooming structures is the length (in microns) of the blooming channel's barrier region. The length of the blooming channel's barrier regions in Anagnostopoulos and Stevens, are unaffected by alignment, but they are not self aligned to the drain. The extra amount of area that must be added to compensate for misalignment becomes an important factor for small pixel size devices. Dyck discloses a self aligned structure, but offers little flexibility in adjusting the length of these barrier regions since this length depends on lateral diffusion of the barrier-region implant.
The length of the barrier regions in this structure is only about 0.5 μm. Although this is very short, and therefore conserves the pixel's surface area, it makes the structure susceptible to the so-called DIBL (drain-induced, barrier lowering) effect. This effect can reduce the antiblooming barrier height dramatically thereby resulting in reduced charge capacity and hence, lower dynamic range. This also makes the barrier height sensitive to the LOD voltage. Hence, this voltage may need to be adjusted on a part-to-part basis due to process variations. Also, changing the length of this region requires changing the process (by varying Dt).
As can be seen by the foregoing discussion, there remains a need within the art for an antiblooming structure design that can offer the advantages of self alignment as well as solving the problems associated with short antiblooming barrier lengths.
SUMMARY OF THE INVENTION
It is the object of this invention to solve the above mentioned problems with the prior art. This invention discloses a process for providing a self-aligned, LOD antiblooming structure whose antiblooming barrier height can be set by process (via implantation), and is relatively insensitive to process variations. An extra gate electrode to set the antiblooming barrier height is not required (as with some other disclosures), but may be provided so as to allow for electronic exposure control to use with FT image sensors. The antiblooming overflow channel length is determined photolithographically and is therefore, easily adjusted by layout. The process is simple and compatible with different types of gate dielectrics such as O (SiO 2 ), ON (oxide nitride), or ONO (oxide nitride oxide).
The antiblooming overflow region channel lengths are defined by a first masking layer patterned by standard photolithographic techniques. A second and third masking layer of photoresist are then used to implant the CCD's buried-channel regions and the LOD's n+ drain regions. These three masking layers are subsequently removed, and the CCD processing proceeds in a conventional manner. Optionally, the first masking layer may be left intact and used as gate control for electronic exposure control as mentioned above. In this case, this masking layer is formed from suitable conductive material such as polysilicon, ITO (indium-tin oxide), etc.
It is an object of the invention to provide a method of manufacturing an antiblooming structure for image sensors comprising the steps of:
providing a semiconductor substrate of a first conductivity type, having an antiblooming channel implant of a second conductivity type opposite the first conductivity type contained on a major surface of the substrate;
defining, with masking layers, a first pattern and a second pattern, upon the major surface of the substrate, the first pattern covering an antiblooming barrier region, and the second pattern covering a drain region, such that the combination of the first and second patterns leave an exposed area defining a CCD buried channel;
creating, by masking, a third pattern that exposes only the drain region and portions of the first pattern adjacent to the drain region;
implanting the drain region with the second conductivity type to form a drain that is self aligned with edges the antiblooming region; and
creating a gate electrode over the structure.
It is still further an object of the present invention to provide an antiblooming structure for image sensing device comprising:
a semiconductor substrate of a first conductivity type, having an antiblooming channel implant of a second conductivity type opposite the first conductivity type contained on a major surface of the substrate;
a buried channel implant formed adjacent to, and self aligned with, at least one edge of an antiblooming barrier region;
a drain formed adjacent the antiblooming barrier region such that it is self aligned with at least one edge of the barrier region; and
at least one gate electrode over the structure.
The above and other objects of the present invention will become more apparent when taken in conjunction with the following description and drawings wherein like characters indicate like parts and which drawings form a part of the present invention.
ADVANTAGEOUS EFFECT OF THE INVENTION
This disclosure describes a self-aligned, lateral-overflow drain antiblooming structure that is insensitive to drain bias voltages and offers improved insensitivity to process variations. The length of the antiblooming barrier regions are easily adjusted and determined by photolithography. The self-alignment feature of this invention improves the quantum efficiency, charge capacity, and dynamic range of the imager for a given pixel size. Also, this LOD antiblooming structure does not require any exotic processing technology. Therefore, this device is highly manufacturable.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross section view through the layers used to construct a CCD channel and antiblooming structure.
FIG. 2 is a cross section of the invention after the first masking layer and second masking layer have been patterned, and the n-type buried channel has been implanted.
FIG. 3 is a cross section of the CCD according to the present invention after the second masking layer 20 has been removed and the third masking layer 30 has been deposited and patterned.
FIG. 4 is a cross section of the CCD illustrating the completed device of the first embodiment of this invention.
FIG. 5 is a cross section of the completed CCD device of the second embodiment of this invention.
FIG. 6 is a top view of a completed device showing antiblooming barrier regions under both phases of an implanted-barrier, true-two-phase CCD.
FIG. 7 is a top view of a completed device showing antiblooming barrier regions under only one phase of an implanted-barrier, true-two-phase CCD.
FIG. 8 is a top view of a prior art device having antiblooming barrier regions requiring allowances for length and width alignment tolerances.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 through 4 show a process by which the first embodiment of the invention is manufactured. Although these figures show a n-type buried channel CCD, a p-type channel CCD could just as easily be formed by reversing the conductivity type of the appropriate layers as would be apparent to one skilled in the art. FIG. 5 shows a second embodiment wherein electronic exposure control is provided. FIGS. 6 and 7 are top views of the device.
Referring to FIGS. 1 through 4, a cross section view through the layers used to construct a CCD channel and antiblooming structure, a p-type substrate 12 is provided with an n-type antiblooming channel implant 16 on a major surface 11 of CCD 10. The uniform, n-type, antiblooming channel implant 16 as shown, along with the gate dielectric 14 thickness and substrate doping, sets the channel potential of this region. FIG. 4 shows gate dielectric 14 where FIG. 1 illustrates an oxide layer 13 (which can be ONO or other oxide material) that could be used as the final gate dielectric 14, the choice of a new gate dielectric layer 14 is a design option. Note that although the substrate is shown as p-type, the invention may be formed in a substrate with or without one or more epitaxial layers and with or without one or more wells as would be obvious to one skilled in the art.
Referring now to FIG. 2, a cross section of the invention at a point in the process after the first masking layer 18 and second masking layer 20 have been deposited and patterned, after which the CCD 10 has an n-type buried channel 35 implanted. The channel potential of the portion of the CCD 10 that has n-type buried channel 35 implanted upon the n-type antiblooming implant 16, as shown, would thus be determined by the summation of the doping levels of the n-type buried channel 35 implant with the doping level of the antiblooming barrier region 16 implant. Therefore, the antiblooming barrier height is determined by the potential difference between the antiblooming barrier height and that of the buried-channel implant.
It should be noted that the buried channel implant 35 is self-aligned to the outside edges of the first masking layer 18 and is therefore, self aligned to the antiblooming barrier region 22 as defined by the regions in the substrate underneath the first masking layers.
The first masking layer 18 may be formed from either: Si 3 N 4 ; polysilicon; ITO; WSi; or other conventional masking materials. However, a conductive material is required for this first masking layer if it is to remain as a gate electrode for electronic exposure control, as will be discussed below in the second embodiment of this invention as seen in FIG. 5. The first masking layer 18 allows the implanting of the buried channel 35 such that it is self aligned to the antiblooming barrier region 16.
The second masking layer 20 is preferably made of photoresist material and is used to mask the area of the antiblooming structure that is later identified as the drain region. The dielectric layer 14 on the surface of the single crystal silicon substrate may be a simple oxide, or some other typical dielectric materials such as ON or ONO. Additionally, layer 13 may be used as the final gate dielectric, or it may be etched off and replaced with another dielectric layer(s) later on in the process as would be obvious to one skilled in the art.
Referring to FIG. 3, which is a cross section of the CCD 10 according to the present invention at a point in the process after the second masking layer 20 has been removed and the third masking layer 30 has been deposited and patterned. This third masking layer 30 is preferably photoresist material. The n+ drain of the lateral overflow drain (LOD) 32 structure is then implanted within the space between the first and third masking layers (18, and 30). The LOD 32 is, therefore, inherently self aligned to the inner edges 19 of the first masking layer 18. This results in an LOD 32 structure that is self aligned to the antiblooming barrier regions 22. It should be noted at this point that the order in which the n+ LOD 32 and CCD buried-channel 35 implants are done could be reversed, and that this would be an obvious variation to those skilled in the art.
Referring to FIG. 4, which is a cross section of the CCD 10 illustrating the completed device of the first embodiment of this invention. Other overlayers such as interconnect isolation layers, light-shield layers, passivation layers, and/or color filter arrays (CFAs) are not shown. The gate electrode 37 of the CCD 10 is preferably some transparent, conductive material such as polysilicon or ITO. It should be understood the use of substrates either with or without epitaxial layers, or with or without wells are obvious variations of the embodiments disclosed herein.
Referring to FIG. 5, which is a cross section of the completed CCD 10 device of the second embodiment of this invention, wherein the first masking layer 18 is formed of a conductive material that is left on the device to act as a gate electrode 39 for electronic exposure control within a frame-transfer device.
FIG. 6 is a top view of a completed device showing antiblooming barrier regions under both phases of an implanted-barrier, true-two-phase CCD. Note the isolation regions 58 that prevent inadvertent transfer of charge to the LOD 55 during normal, CCD readout. Since these regions receive the antiblooming channel and CCD barrier region implants, the channel potential of each of these regions is lower than any other region within the structure, thereby providing isolation.
Referring now to FIG. 7, which is an alternate configuration to which the present invention can be employed, wherein only one phase (phase 2 in this case) has an antiblooming channel. This configuration is discussed in U.S. Pat. No. 5,349,215. The blooming channel under phase 1 is eliminated by implanting these regions with both the antiblooming channel implant 53 and CCD barrier region implants 69, thereby effectively turning these regions off (as done to form the CCD-to-LOD isolation regions as discussed above). This has the effect of forcing excess charge into the second phase of the CCD in order for any antiblooming action to take place. The construction of such a device is enhanced via self alignment as taught by the present invention.
Referring to FIG. 8, there are additional advantages of the present invention which will be described further below. The amount of antiblooming protection (X AB ) can be shown to be given by the relationships below.
X.sub.AB =1+2α 1+(W.sub.AB L.sub.CD /L.sub.AB W.sub.CCD)e.sup.δv/nV t! Equation 1
Where:
α is charge in adjacent, unilluminated pixel as a fraction of charge in the, illuminated pixel at the onset of blooming. (Typically defined to be 0.5);
W AB , L AB is the width and length of antiblooming barrier region, respectively;
W CCD , L CCD are the width and length of the CCD barrier regions, respectively;
δV is the potential barrier height difference between the antiblooming barrier region and the CCD barrier region;
n is the nonideality factor (typically about 1.0 for LOD structure);
V t is the thermal voltage, kT/q, equal to approximately 26 mV at room temp.
k is Boltzman's constant.
T is the absolute temperature.
q is the charge of an electron.
Therefore for δV greater than 50 to 75 mV, which represents two to three times kT/q at room temperature, and with α=0.5,
X.sub.AB ≈(W.sub.AB L.sub.CD /L.sub.AB W.sub.CCD)e.sup.δV/nV tEquation 2
From the above relationships, it is clearly evident that the amount of blooming protection is proportional to the width of the antiblooming channel and inversely proportional to its length. Prior art devices have alignment tolerances that require spacing. This tolerance space occurs at the expense of space used, otherwise, for antiblooming channel width, for example. These tolerances can be seen in FIG. 8, which is an illustration of a similar device to that of FIG. 6, however the device of 8 is without the self alignment feature of the antiblooming channels taught by the present invention. The width of the antiblooming channel within the relationship indicated by Equation 1 and Equation 2 is W2 (62) on FIG. 8. W2 (62) is narrowed by an amount equal to twice the tolerance width, indicated as T w (63). This is corrected in the present invention by creating a self aligned antiblooming channel that does not require alignment tolerances. This results in an increase in the width of the antiblooming channel and increased blooming protection. Additionally, improved quantum efficiency and charge capacity results.
Referring once again to the device of FIG. 6 there are isolation regions 58 between phases within the CCD. The isolation regions 58 are constructed to receive both the antiblooming region implants 53 and the CCD barrier region implants 69. The CCD barrier implants are conventionally used to create an implanted barrier two phase device. These isolation regions prevent inadvertent transfer of charge into the LOD during normal charge transfer between phases. These isolation regions are present in the same relative positions under all phases 1 and 2 of the CCD. The self aligned antiblooming regions are naturally employed to construct these isolation regions resulting in self aligned isolation regions.
In the following description, like reference characters designate like or corresponding parts throughout the several views of the drawings. Also in the following description, it is to be understood that such terms as "forward", "rearward", "left", "right", "upwardly", "downwardly", and the like, are words of convenience and are not to be construed as limiting terms.
The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.
PARTS LIST
10 CCD
12 p-silicon substrate
13 Dielectric layer
14 Dielectric layer
22 Antiblooming barrier region openings
30 Third masking layer
31 LOD implant opening
32 LOD
35 n-type channel
37 gate electrode
42 n-type antiblooming barrier implant
53 Antiblooming barrier region
55 LOD
56 isolation regions
58 isolation regions
62 W2 width of prior art antiblooming channel
63 T w , the antiblooming width tolerance
65 T L , the antiblooming length tolerance
69 CCD barrier region implants
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A self aligned, lateral-overflow drain antiblooming structure that is insensitive to drain bias voltages and therefore has improved insensitivity to process variations. The length of the antiblooming barrier regions are easily adjusted and determined by photolithography. The self aligned, lateral-overflow drain (LOD) antiblooming structure results in a design that saves space, and hence, improves overall sensor performance. In this structure, an antiblooming potential barrier is provided that is smaller (in volts) than the barriers that separate the pixels from one another so that excess charge will flow preferentially into the LOD as opposed to the adjacent pixels.
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FIELD OF THE INVENTION
The invention pertains to mounts for outboard engines. More particularly, the invention pertains to adjustable mounts intended for use with pontoon boats.
BACKGROUND OF THE INVENTION
Pontoon boats include a pair of elongated pontoons which support a platform spanning between the pontoons. An outboard engine or outboard motor (terms used interchangeably) is supported from the platform at a position intermediate the pontoons at a rear of the boat.
An engine mount is connected to an underside of the platform. The engine mount comprises an elongated hollow body or trough which extends longitudinally and rearwardly of the rear end (stern end) of the platform. The body is exposed to the water beneath the boat. The engine mount is substantially closed except for a top opening at a rear of the boat. A fuel tank is held within the body, accessed through the top opening. The outboard motor is bolted to the rear wall of the body. The prior known mount is non-adjustably fixed to the platform. No range of vertical adjustment for the outboard engine is provided by the mount.
The present inventors have recognized that it would be desirable to provide a vertical adjustability at the engine mount such that outboard engines could be optimized for depth below waterline. Additionally, the present inventors have recognized the desirability of providing a vertical adjustability at the engine mount so that a variety of commercially available outboard engines can be attached to the boat, and the boat tuned to the engine by adjusting the depth of the motor beneath the waterline.
SUMMARY OF THE INVENTION
An adjustable engine mount is provided that includes a tapered, elongated body which is couplable to, and vertically adjustable relative to, the hull of a watercraft. The body has a first, smaller end oriented toward the bow of the watercraft and a second, wider end positioned adjacent to the stem of the craft. An engine-mounting wall or mounting plate is attached to the second end of the body. An outboard motor or outboard engine can be attached to the mounting plate. By vertically adjusting the body with respect to the hull, the elevation of the outboard motor with respect to the watercraft or with respect to the waterline, can be adjusted. The adjustment can be utilized to optimize performance of an outboard motor. The adjustment provides flexibility for the use of different model outboard motors on the watercraft.
In one aspect of the invention, the body is substantially hollow and extends rearwardly from a back edge of the watercraft, defining a top opening. An elongated fuel tank can be placed within the body to be connected by a fuel line to the outboard motor. By having an elevation-adjustable body, access for installing and removing the fuel tank is improved. The body can be lowered to provide more clearance for maneuvering the fuel tank partially beneath the back edge of the watercraft.
In another aspect, the body can be formed with a multi-sided, generally U-shaped cross section. The planar sides are tapered and extend smoothly without protrusions between the ends.
Two exterior elongated rails or supports, rigidly coupled to the craft, extend axially therealong and provide support for the body. The body is attached to the rails at a plurality of longitudinal positions between the bow end and stem end of the craft.
In another aspect, the rails, at the stem end, can include a plurality of spaced apart bolt holes or, alternately, protrusions. The stern end of the body can be releasably locked into a selected vertical position by using bolts that extend through the holes, or alternately by using holes which receive the protrusions.
An engine can be coupled to the mounting plate. The mounting plate will in turn support the engine at the vertical position relative to the craft.
In yet another aspect, the body can be formed with four planar tapered sides. Two of the sides extend generally parallel to one another along and beneath the craft. In this embodiment, the mounting plate extends between the parallel sides generally perpendicular thereto.
In a further aspect of the invention, the braces can include a bottom flange having a downturned lip which acts as a splash guard to help prevent water from splashing into the engine mount body.
Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a watercraft utilizing the engine mount of the present invention, wherein an outboard motor is not shown for clarity of view of the engine mount;
FIG. 2 is a sectional view taken generally along line 2 — 2 of FIG. 1, with an outboard motor installed;
FIG. 3 is an enlarged sectional view taken generally along lines 3 — 3 of FIG. 2;
FIG. 4 is a perspective view of a body portion of the engine mount of FIG. 1;
FIG. 5 is an elevational view of one of two retainer plates, to be attached to portions of the body portion shown in FIG. 4;
FIG. 6 is a perspective view of one of two braces which are each attached to a region of the body portion of FIG. 4;
FIG. 7 is an enlarged elevational view of the engine mount of FIG. 1, separated from the watercraft; and
FIG. 8 is an enlarged, fragmentary, top perspective view of a stern end of the mount separated from the watercraft, as shown in FIG. 7; and
FIG. 9 is an enlarged, fragmentary, rear perspective view of the watercraft shown in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While this invention is susceptible of embodiment in many different forms, there are shown in the drawings and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated.
FIG. 1 illustrates a watercraft 20 . The watercraft 20 includes a platform 26 supported on parallel pontoons 30 , 32 . For simplicity, the platform is shown as a plain floor surrounded by a railing, but the platform could be adapted to provide seating for people, or storage for cargo, or structure for a houseboat, as only a few examples. Mounted to the platform 26 , between the pontoons 30 , 32 , is an elongated engine mount 36 . The engine mount 36 includes a trough-like hollow body 40 , closed at a rear end (stem end) by an engine-mounting wall or plate 44 . An outboard motor is coupled to the wall 44 as described below. The body 40 is connected intermittently along its length to support rails 50 , 52 . The support rails 50 , 52 are connected intermittently along lengths thereof to an underside of the platform 26 . The engine mount 36 extends rearwardly of a back edge 56 of the platform 26 , defining a top opening 58 .
FIG. 2 illustrates the engine mount 36 beneath the watercraft 20 . The rail 52 is connected to the body 40 by five bolted connections 62 , 64 , 66 , 68 , 70 . An end plate 74 substantially closes a front end (bow end) of the mount body 40 . A motor plate 80 supports an outboard motor 82 . The motor plate 80 is bolted to the engine-mounting wall 44 using bolts 83 . The mounting wall 44 includes a top channel portion 45 which reinforces the top free edge of the wall 44 and also provides a guiding retainer for a fuel line, control cables or other like devices. Two inside reinforcing channels 44 a , 44 b are disposed facing against the inside surface of the mounting wall 44 . The lower channel 44 a is welded to the body 40 . The upper channel 44 b can be held to the wall 44 by the bolts 83 which penetrate through the wall 44 and a respective channel 44 a , 44 b . The channels 44 a , 44 b provide additional strength to the wall 44 .
The bolted connection 62 includes a bolt 62 a penetrating a circular hole 62 b . The connections 64 , 66 include bolt 64 a , 66 a each penetrating through a slot 64 b , 66 b respectively, which allows for rotation of the body 40 about the bolted connection 62 during adjustment. Although three connections 62 , 64 , 66 are shown, it is also encompassed by the invention to use a different number of connections such as one or more than three, depending on the requirements of a particular design.
The bolted connections 68 , 70 , include bolts 68 a , 70 a , that penetrate through two holes selected from a plurality of holes 69 , spaced at different elevations. The holes 69 are arranged along a circle having its center point at the connection 62 . With the connections 62 , 64 , 66 loosened, and before the bolts 68 a , 70 a are installed, by pivoting the body 40 about the connection 62 , different holes 69 can be selected to change or adjust the elevation of the mounting wall 44 . In this regard the elevation of the motor 82 can be changed as shown dashed in FIG. 2 .
After adjustment, all the connections 62 , 64 , 66 , 68 , 70 can be tightened. Although two bolts 69 a , 70 a are shown, a different number of bolts can be used such as one or more than two, depending on the requirements of a particular design. Although a plurality of holes 69 are shown, it is also encompassed by the invention that the holes 69 are replaced by a curved slot arranged on a circular path having its center on the connection 62 .
The connections 68 , 70 are illustrated in FIG. 3 . The bolts 68 a , 70 a are inserted through two selected holes of the plurality of holes 69 . The rails are substantially channel-shaped in cross-section, having a continuous top flange 86 , a web 87 and a bottom flange 88 . The rails 50 , 52 are connected to the deck 26 by a plurality of longitudinally spaced bolted connections 84 , extending through the top flange 86 of the rails, respectively. Alternatively, the rails can be connected to the deck by brackets and/or by welding. The bottom flange 88 has a downturned end portion or deflector lip 92 which acts as a splash guard. The deflector lip 92 helps to keep water out of the engine mount body 40 . The body 40 includes retainer plates 96 which have hexagonal holes for receiving, and restricting rotation of, hexagonal bolt heads 98 of the fasteners 68 , 70 . Thus, the bolts can be loosened from the outside without the need to grip the bolt heads 98 with a tool to prevent rotation of the bolt heads.
The retainer plates 96 are each respectively welded to inside surfaces of sidewalls 106 , 108 of the body 40 . The retainer plate 96 is also preferably composed of aluminum and is 0.250 inches thick. The sidewalls 106 , 108 are connected to angled bottom walls 112 , 114 . Together, the walls 106 , 108 , 112 , 114 form a generally U-shaped cross-section of the body.
FIG. 4 illustrates the body 40 having side walls 106 , 108 and bottom walls 112 , 114 . The four walls 106 , 108 , 112 , 114 can be formed by bending a single sheet of aluminum. The sheet is preferably 0.170 inches thick. Each of the side walls 106 , 108 has a region 106 a , 108 a (shown in phantom) which receives one retainer plate 96 attached thereto by welding. Each sidewall 106 , 108 includes a plurality of spaced apart circular holes 120 for receiving the shank of bolts 62 a , 64 a , 66 a , respectively.
FIG. 6 illustrates one of the rails 50 . The rail 52 is mirror image identical. The rail 50 is configured in a channel shape having a tapering height from stem end to bow end. The top flange 86 also includes a downturned flange lip 121 for added rigidity. The rail is also preferably composed of aluminum and is 0.170 inches thick. The rail 50 includes the plurality of holes 69 arranged substantially vertically along the circular arc having its center at the connection hole 62 b . The bolts 68 a , 70 a are arranged to also be along the same circular arc, such as to be positionable within select ones of the holes 69 , for adjusting the elevation of the engine-mounting wall 44 . The slots 64 b , 66 b are arranged extending along circular arcs also having centers at the centerline of the connection hole 62 b . The bottom flange 88 of the rail 50 includes the angled lip 92 which is turned at an angle A, preferably being about 55 degrees at the stern end.
FIG. 7 illustrates the body 40 and the rail 52 assembled, but shown without bolts for clarity of view. The angle A of the lip 92 is gradually straightened out toward a front of the rail 52 , i.e., the angle A gradually diminishes to zero degrees, wherein the lip blends into the rest of the bottom flange 88 . The lip 92 blends into the rest of the bottom flange 88 , at a point p about midway between the slot 64 b and the hole 62 b . A reinforcing, rectangular gusset plate 130 is welded to the upper and lower flanges 86 , 88 and to the web 89 to reinforce the rail adjacent to the bolted connections 68 , 70 .
The mount 36 is tapered from its stem end toward its bow end, tapered both in plan and in elevation, to provide a streamlined profile to reduce splashing and water resistance or drag as the watercraft moves through the water. In this regard the preferred dimensions (in inches), as indicated in FIGS. 4 through 7, are: a=9¼; b=13½; c=74; d=4; e=2; f=4¾; g=3¼; h=3½; i=68; j={fraction (15/16)}; k=8¼; m=3; n={fraction (15/16)}; q=68; r=15½; s=71; t=1.
FIG. 8 illustrates the mount 36 with the fuel tank 59 within the body 40 . The mounting wall 44 is welded all around with a bead 127 to the sidewalls 106 , 108 , and the bottom walls 112 , 114 . A small gap 128 in the weld at the intersection of the bottom walls provides a drain for water which enters the body 40 . The channel portion 45 extends above the side walls 106 , 108 and is welded thereto via prone L-shaped pieces 131 , 133 .
FIG. 9 illustrates the inside of the body 40 at the stem end. The L-shaped pieces 131 , 133 are further connected to the sidewalls 106 , 108 by horizontal triangular reinforcing plates 141 , 143 . The channel 44 a is connected to, and overlies, a bottom half of the inside of the mounting wall 45 . Two L-shaped spacers 145 , 147 protrude from the inside wall 145 toward the bow end and act to retain the fuel tank 59 . A triangular notch 151 through the channel 44 a provides fluid communication with the gap 128 for draining the body 40 . Bolt holes 155 , 157 are used for mounting the outboard motor. The upper channel 44 b is not shown in FIG. 9 but is substantially similar to the lower channel 44 a.
From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.
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An adjustable engine mount for a pontoon boat makes it possible to adjust the relative position of an outboard engine relative to the waterline of the boat. The mount has an elongated, tapered, four-sided body which is attached to the bottom of the hull of the boat by a pair of spaced apart, elongated mounting rails. The body is a substantially U-shaped, continuously changing cross section with an engine-mounting wall located adjacent the stern of the boat. The bow end of the body is pivotably attached to the mounting rails. The stem ends of the rails have a plurality of vertically disposed bolt holes. The vertical position of the body can be adjusted by selecting which vertically disposed bolt holes in the rails to use.
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BACKGROUND OF THE INVENTION
[0001] I. Field of the Invention
[0002] This invention relates generally to septic tank cover systems, and more particularly to septic tank cover systems which are designed to provide access to septic tanks, seal septic tanks from water, and prevent tank leakage.
[0003] II. Discussion of the Prior Art:
[0004] It is well known that access to septic tanks buried underground is periodically needed so that material can be pumped from the tank and maintenance performed. It is important for structures which provide access to the tanks to maintain a water tight environment leading to the buried septic system. The seals for these structures are greatly susceptible to leaks due to their exposure to an outdoor conditions. Frost heaving, forces related to vertical ground movement, and rotational forces due to lateral ground movement can each have a potentially detrimental impact on the integrity of septic tank access structures.
[0005] To improve the longevity and durability of access points to septic tanks, it is desirable, as much as possible, to protect the structure from potentially damaging types of ground forces. Various aspects of these problems have been addressed in some previous disclosures although a design specifically suited to properly address these concerns has never been as fully and effectively designed before. For example, in the Meyers. U.S. patent application Pub. No. 2003/0145527, a riser component for an on-site waste system is described which incorporates a riser pan, a cover, and various interconnecting riser elements. The Airhart U.S. patent application Pub. No. 2004/0040221 is directed at a molded manhole unit. This application shows a unit with a manifold riser having a beveled riser edge, a riser extension which mates with the manifold riser, a sealing ring, and a riser cap.
[0006] The present invention offers important advantages over the prior art due to new concepts included in its design. Specifically, the arrangement of the riser base of the present invention offers several superior features not found in the prior art. These features relate to the ledge and depressions below the ledge that allow secure anchoring of the device into a concrete casting. These advantages also include the uninterrupted surface upon which the pipe member can rest. This surface provides an effective mechanism for sealing the junction between the base and the pipe. The use of corrugated pipe also provides certain advantages in terms of cost, strength, and the ability for one to cut the pipe to length rather than having to buy a specific piece of a specific height. The invention overcomes the problems associated with using such a pipe by providing a novel sealing surface between the pipe and the top cover, a novel sealing arrangement between the riser base and the pipe, and also by providing a sleeve that covers the corrugations in the pipe to prevent the pipe from coming loose from the base due to ground forces. Finally, the manner in which the top cover of the present invention engages the pipe to provide an effective seal that is much more refined and simple than what is shown in the prior art.
SUMMARY OF THE INVENTION
[0007] The present invention provides for a cover system for septic tanks which is adapted to be attached to a septic tank and provide a water tight seal access for pumping the contents of the tank and maintaining the tank. The assembly includes a base member which is embedded into the concrete of an underground septic tank providing a seal between the concrete and the base. A pipe member is joined to and sits atop this stationary base member. A wrap made of high density polyethylene surrounds the pipe and covers its corrugations to reduce outside forces upon the pipe. Additionally, there is a top cover which is designed to engage the top of the pipe. Further, a channel is provided on the base to catch the edge of the pipe, novel seals are provided to prevent leakage between the pipe and cover and between the pipe and base. These features work together to form a stable and water tight structure for closing an access opening to a septic tank.
[0008] These and other objects, features, and advantages of the present invention will become readily apparent to those skilled in the art through a review of the following detailed description in conjunction with the claims and accompanying drawings in which like numerals in several views refer to the same corresponding parts.
DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of the septic cover assembly of the present invention without the outer wrap member;
[0010] FIG. 2 is a perspective view of the base member of the septic cover assembly;
[0011] FIG. 3 is a perspective view of the pipe member of the septic cover assembly;
[0012] FIG. 4 is a perspective view of the cover member of the septic cover assembly;
[0013] FIG. 5 is a perspective view of the septic cover assembly without the outer wrap member; and
[0014] FIG. 6 is a perspective view of the septic cover assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] The present invention represents broadly applicable improvements for septic tank design to provide an effective sealed means and stable structure for accessing a septic tank. The embodiments herein are intended to be taken as representative of those in which the invention may be incorporated and are not intended to be limiting.
[0016] Referring first to FIG. 1 , there is a perspective view of the septic cover assembly shown which would be buried in the ground and cemented in place to provide convenient access to a septic tank from above the ground. The assembly itself is indicated generally by numeral 10 and includes a base 12 , a pipe 14 , a top cover 16 , and a wrap 17 (see FIG. 6 ). These four components work together to form an invention which create a passageway of structural integrity well-suited for continued and efficient access to a desired septic tank.
[0017] FIG. 2 discloses a perspective view of the base member 12 of the septic cover assembly allowing for a more detailed examination of its features. Base 12 is a largely cylindrical component which is made of high density polyethylene. It provides a riser coupling which is primarily embedded within concrete and forms a seal between the concrete and the base 12 . The riser coupling has a 24-inch opening providing access to the concrete tank in which the base 12 is embedded. Base 12 is comprised of four annular sections 18 , 20 , 22 , and 24 . The first annular section 18 is made up of a cylindrical wall containing a plurality of depressions 26 which fill with concrete that encapsulates section 18 of the base member 12 when concrete is poured around it. This arrangement prevents the base member from rotating in the concrete.
[0018] Directly above first annular section 18 is a second annular section, ledge 20 . Ledge 20 is an annular protrusion which extends radially outward to achieve a diameter substantially larger than the previous diameter of section 18 . Ledge 20 has an upper lip 28 and a lower lip 30 that diverge from one another as the annular protrusion extends radially outward. Lip 28 and lip 30 are joined by a vertically disposed outer surface 31 . These features prevent the base member from moving up or down with respect to the tank when the ledge 20 is embedded in the concrete. These features of ledge 20 also stiffen the upper structure of the base when the ledge 20 is fully encapsulated by concrete.
[0019] Juxtaposed directly above ledge 20 is a third annular section 22 . Section 22 has a smaller diameter than ledge 20 . The top rim edge 32 of rim 22 marks the height to which concrete is filled when poured around base 12 . The rim edge 32 is the feature pipe 14 abuts up against when it is slid onto base 12 , as will be later discussed. The edge 32 also assists in providing a water tight seal between the pipe 14 and the base 12 .
[0020] The last annular section is a riser coupling 24 which has a cylindrical portion 34 of constant diameter and an inwardly projecting lip 36 . This section provides a sturdy projection which mates with and is generally covered by pipe 14 . It also provides a further barrier to the outside environment.
[0021] Referring now to FIG. 3 , a section of pipe 14 is shown. Pipe 14 is a 24-inch diameter dual wall pipe. The pipe must extend from the base 12 when it is buried underground to above ground level. Thus, dual wall pipe is used that can be cut to length. The length of pipe is typically cut at the time of installation and is made between the corrugations. Only the length of two corrugations of pipe are shown in FIG. 3 although various much longer lengths of pipe containing many more corrugations are common. The pipe 14 is designed to be slid over the top of the riser coupling 24 so that the bottom edge 38 of the pipe 14 will come in contact with the concrete filled to rim edge 32 . A seal can be provided at the intersection of the pipe 14 and the concrete to prevent leakage. Pipe 14 has a smooth inner wall 40 and a corrugated outer wall 42 . The corrugations serve to strengthen the pipe. Because this cut-off edge can be non-uniform, it is not a suitable surface for sealing. Therefore, for an effective seal to be made between the pipe 14 and the cover 16 , one must be made on the top surface 44 of the top corrugation of the pipe.
[0022] FIG. 4 shows the cover 16 of the present invention. The cover generally comprises a flat upper disc component 46 and a lower cylinder component 48 protruding downward from the upper disc 46 . The lower cylinder 48 is formed so that it may be inserted snugly within the smooth inner diameter of pipe 14 . The upper disc 46 maintains a diameter slightly larger than the corrugated outer wall of the pipe 42 and is the above ground, exposed portion of the cover system 10 . In the area surrounding the lower cylinder's protrusion from the upper disc is a slightly raised ring of material 48 . This portion of the upper disc 46 is the contact surface corresponding to the seal on the top corrugation surface 44 of pipe 14 . The mating established between the cover surface 48 and the seal is water tight. Additionally, there is an inclined surface 49 between the flat outer portion of the disc and the raised material 48 . The upper disc 46 of cover 16 contains multiple holes 50 around its periphery which can be used to place a padlock or some other kind of locking mechanism for the prevention of unauthorized access to the septic system. Two cylindrical depressions 52 also exist on the top surface of the cover (see FIG. 5 ).
[0023] FIG. 5 shows the cover 16 , pipe 14 , and base 12 of the device as they would be in an assembled device, absent the wrap 17 . Cylindrical depressions 52 are shown as well. Suitable gaskets or other sealing materials are also provided in the seal ares between the pipe 14 and the concrete and between the relatively flat area of the top corrugation of the pipe 14 and the cover.
[0024] FIG. 6 discloses the final component of the device, wrap 17 , added to the assembly. Wrap 17 is made of high density polyethylene material which surrounds the pipe 14 . Often the corrugations of pipe 14 present a problem when the pipe is buried in the ground, due to frost or other heaving of the surrounding soil. This can cause the pipe to actually be lifted off of the base 12 due to the forces imparted by changing soil conditions. Wrap 17 is intended to prevent this heaving problem. Wrap 17 surrounds the pipe and covers the corrugations so that forces caused by frost or the like are not applied to bottom portions of the corrugations in the pipe. Such forces are what would otherwise cause the pipe to be lifted from the base. The wrap provides a smooth outer wall surface rather than the corrugations in the pipe.
[0025] Now that the details of the mechanical construction of the septic cover assembly 10 of the present invention have been described, consideration will next be given to its mode of operation.
[0026] During construction of an underground concrete septic tank, the base member 12 in imbedded into the concrete. The concrete surrounds the outer edge of base member 12 such that concrete, embeds within depressions 26 , completely encapsulates ledge 20 , and extends to the level of rim edge 32 and top of the concrete. A watertight attachment is thus formed between the tank, the base member 12 and the bottom of pipe 14 . Once the concrete hardens, the tank is placed in a hole in the ground. The pipe 14 is cut such that the top of the pipe is approximately even with or slightly above ground level. A seal such as a gasket is positioned so that it surrounds the base member 12 . Corrugated pipe 14 is slid over the exposed riser coupling 24 of the base and up against the channel formed by the rim edge 32 . Next, a seal is placed along the pipe's top corrugation surface 44 as opposed to the cut edge which tends to be uneven. A cover 16 is then placed within and above pipe 14 , engaging against the seal on the top corrugation surface 44 to form a second watertight connection. The cover 16 is locked with a padlock and opened when access is needed for maintenance or repair of the septic tank.
[0027] It can be seen, then, that the present invention provides an improved and efficient apparatus for gaining access to a septic tank which functions to effectively seal the tank from water and prevent tank leakage.
[0028] This invention has been defined 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 details and operating procedures, can be accomplished without departing from the scope of the invention itself.
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A cover system for septic tanks adapted to be attached to the a septic tank and provide access for repair and maintenance. The assembly includes a base which is embedded into the concrete and provides a seal between the concrete and the base. A pipe member is joined to and sits atop the stationary base member. A wrap made of high density polyethylene surrounds the pipe and covers its corrugations to reduce outside forces upon the pipe. Finally, there is a top cover which is designed to engage the top of the pipe. Additionally, a channel is provided to catch the edge of the pipe and a seal is provided to prevent leakage between the pipe and cover.
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This is a continuation of application Ser. No. 09/094,092, filed Jun. 8, 1998 U.S. Pat. No. 5,976,419.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention pertains to a corrosion prevention system and method of producing the same, and more specifically to a system for protecting a metal substrate from corrosion utilizing a cathodic coating comprising at least one inherently conductive polymer and sacrificial metal particles.
2. Description of the Related Art
One type of coating used to protect metals from corrosion is called a barrier coating. Barrier coatings function to separate the metal from the surrounding environment. Some examples of barrier coatings include paints and nickel and chrome plating. An effective barrier coating includes a layer of the conductive polymer polyaniline. However, as with all barrier coatings, holidays in the barrier coatings leave the metal substrate susceptible to corrosion. Electrochemically active barrier coatings, such as nickel, chrome, and conductive polyaniline layers, can actually accelerate corrosion of underlying metals at holidays in the coating.
Another type of coating used to protect metal substrates are call sacrificial coatings. The metal substrate is coated with a material that reacts with the environment and is consumed in preference to the substrate it protects. These coatings may be further subdivided into chemically reactive, e.g., chromate coatings, and electrochemically active, or galvanically active, e.g. , aluminum, cadmium, magnesium, and zinc. The galvanically active coatings must be conductive and are commonly called cathodic protection.
In the art, a major difficulty has been the creation of a coating that protects like a cathodic system but is applied with the ease of a typical barrier coating-system. Furthermore, there are many environmental drawbacks with both traditional barrier and sacrificial methods, from use of high levels of volatile organic compounds to expensive treatment of waste waters produced by plating and subsequent surface preparation for top-coating processes.
The present invention contemplates a new and improved coating system and method of producing the same which overcomes the foregoing difficulties and others while providing better and more advantageous overall results.
SUMMARY OF THE INVENTION
In accordance with the present invention, a new and improved cathodic corrosion resistant coating system is provided which may be easily applied in an environmentally friendly, efficient, safe and cost effective way to a metal substrate.
More particularly, the coating system utilizes at least one inherently conductive polymer in combination with galvanically anodic metals dispersed in a resin matrix and applied to a metal substrate to create a cathodic coating which is corrosion resistant.
In accordance with the invention, a coating composition is provided for use in protecting metallic substrates from corrosion comprising at least one inherently conductive polymer and metal particles anodic to the substrate dispersed in a resin base.
According to another aspect of the invention, a method of protecting a metallic substrate from corrosion is provided including the steps of preparing a surface of the substrate; coating the prepared surface with a coating composition comprising an inherently conductive polymer and metal particles anodic to the substrate dispersed in a resin base; and, curing the coating composition to form a corrosion resistant coating.
According to another aspect of the invention, a method of preparing a coating composition is provided including the steps of dispersing at least one inherently conductive polymer and metal particles anodic to the intended substrate in a resin base material.
According to yet another aspect of the invention, the coating composition may be a high solids formulation.
According to yet another aspect of the invention, the coating composition may be a TV curable formulation.
According to yet another aspect of the invention, the coating composition may be a powder coating formulation.
One advantage of the present invention is that the claimed coating can utilize most conventional methods for application, including dipping, brushing, rolling, spraying, fluidized bed, electrostatic powder, and thermally sprayed powder.
Another advantage of the present invention is the reduction or elimination of the emission of volatile organic compounds into the atmosphere.
Another advantage is the elimination of the rinsing processes associated with galvanizing and plating operations, surface preparation for top-coating, and subsequent waste water treatment.
Another advantage is the reduction of the levels of zinc, lead, cadmium, and other heavy metals in water systems and soil due to weathering of galvanized and plated structures.
Another advantage of the present invention is the cost effectiveness of the process. The coating may be produced at a reasonable cost and applied with existing application systems. Use of the inventive coating system will extend service life and reduce the costs associated with corrosion maintenance.
Still other benefits and advantages of the invention will become apparent to those skilled in the art to which it pertains upon a reading and understanding of the following detailed specification.
DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein:
FIG. 1 shows a process flow chart for producing three types of cathodic coatings according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention concerns a cathodic coating for ferrous or non-ferrous metal substrates. Generally, the coating system utilizes inherently conductive polymers and metal particles anodic to the metallic substrate dispersed in a coating matrix. It has been found that the coating system disclosed herein provides unexpected and significantly improved corrosion protection by forming an adherent, electrochemically active, and truly cathodic protective coating.
The inventive coating system effectively creates an electron path by the thorough dispersion of one or more conductive polymers and metal particles which eliminates dielectric barriers associated with other organic systems, thus creating a protective galvanic corrosion cell.
The present invention is directed to coating systems utilizing at least one inherently conductive polymer and metal particles anodic to the substrate dispersed in a resin base. The coating systems of the present invention may be formulated as high solids systems, radiation curable systems, and powder coat systems.
For the purposes of the present invention, “High Solids” means an ambient temperature curable coating that complies with the Los Angeles County Rule 66 definition, i.e. 80% non-volatiles by volume or greater. “Radiation Curable” involves the polymerization and crosslinking of functional monomers and oligomers (usually liquid, can be a powder) into a crosslinked polymer network (usually a solid film) induced by photons (UV curing) or electrons (EB curing). The curing can occur by either free radical or cationic polymerization. Infrared and beta radiation can also be utilized as energy sources for some radiation cure processes. “Powder Coating” involves coating objects with electrostatically sprayed, thermally sprayed, or fluidized polymer powder under influence of thermal energy causing the fine powder to melt or crosslink around the object and upon cooling to produce a compact polymeric layer. The process steps and equipment to produce the coatings of the present invention are described below.
In general, the preferred conductive polymer for use in each of the systems is polyaniline. Aluminum is the preferred anodic metal particulate, however, any anodic metal that creates sufficient potential difference from the metal substrate may be used according to the invention. Preferably, at least a 0.02 volt potential difference is established. In the preferred embodiment, the coating should produce a polarize cathode surface of -0.85 volts or more electronegative potential when measured using a copper-copper sulfate electrode place close to the electrolyte/structure interface. This measurement is actually a measurement of voltage drop at the interface of the metallic substrate surface and the electrolyte with the reference cell being one contact terminal and the metal surface being the other terminal.
General formulations for the coating systems according the invention are set forth as follows:
A. Resin Base:
1. High Solid Coatings
a. Polyurethane
b. Epoxy
c. Neutral or acidic pH resins
2. UV Radiation Curable
a. Acrylates
b. Polyurethane
c. Epoxy
d. Polyester
3. Powder Coat
a. Epoxy
b. Polyurethane
c. Polyester
d. Glycidyl acrylate
f. Hybrids or resin blends, i.e. polyester and epoxy
B. Inherently Conductive Polymers
1. Polyaniline
2. Polypyrrole
3. Polythiopene
4. Polyacetylene
5. Poly (p-phenylene)
6. Poly (p-phenylene vinylene)
7. Poly (p-phenylene sulfide)
8. Polyaniline substituted with alkyl, aryl, hydroxy, alkoxy, chloro, bromo, or nitro groups
C. Anodic Metal Particles
1. Aluminum
2. Cadmium
3. Magnesium
4. Zinc
5. Alloys of the above metals
D. Plasticizers
1. Sulfonamide
2. Phosphate Ester types
E. Curing Agents
1. Sulfonamide
2. Anhydride types
3. Photoinitiators
a. free radical types
b. cationic types
F. Other Additives
1. Surfactants
2. Catalysts
3. Adhesion Promoters
4. Solvent
With reference to FIG. 1, a process flow chart describing each type of coating system is provided. The following examples of each of the systems show how the instant invention may be practiced, but should not be construed as limiting the invention. The general process is described with exemplary materials in parentheses.
High Solids System
The process steps for making and applying an exemplary high solid system are shown in FIG. 1, steps 1.a. through 1.g.
The process for making the coating is outlined in steps 1.a. through 1.c. Any suitable multi-agitator mixer may be utilized for the blending, dispersion, and grinding operations.
The conductive polymer (polyaniline powder) is dispersed in a quantity sufficient to achieve the desired potential along with a plasticizer (sulfonamide) into a (polyurethane) resin base. The dispersion is high shear mixed for approximately 30 to 45 minutes at a process temperature of from approximately 70° to 150° F.
Any remaining additives and solvent (not to exceed about 15% by weight), are added to the dispersion and blended for additional time, while maintaining the process temperature. If a two-part coating system is desired, the catalyst should not be added to this mixture until just prior to application of the coating.
The metal, in the form of finely divided particles (aluminum powder or flake), is added to the mixture in a quantity sufficient to achieve the desired potential. Preferably, pure low oxidation aluminum flake or aluminum powder atomized and quenched in an inert environment is used. The aluminum can also be coated with stearic acid to preserve the deoxidized surface. Disperse and grind this mixture further utilizing the same equipment as the previous steps. Grind and disperse for additional 45 minutes or until desired fineness of grind is achieved while maintaining the process temperature below 150° F.
Step 1.d. is a packaging step. Any suitable polypropylene or plastic container can be utilized as packaging. The high solid coating mixture can be discharged directly from the mixing vessel into the packaging container. If a two part system is used, Parts A and B would be packaged separately using methods known in the art.
Surface preparation of the substrate is outlined in step 1.e. A blast cabinet or similar means may be utilized for mechanical surface preparation. Alternately, other methods of surface preparation, including chemical means such as deoxidizing baths, may be utilized. The preferred method comprises lightly blasting the substrate with aluminum oxide grit. The prepared surface should be coated as soon as possible.
Step 1.f. outlines the application of the coating to the substrate. The high solids system is suitable for various methods of applications that are well known and practiced in the art. The coating should be thoroughly mixed prior to application by stirring or shaking. Also, the catalyst should be added at this time if a two part coating is used. The coating can be applied by dipping, brushing, rolling, or spraying. Coating should be applied uniformly to all surfaces to be coated to a wet coat thickness sufficient to achieve a wet film thickness of 2 to 10 mils.
Step 1.g. is a curing step. Curing can be accomplished by allowing the coated item to stand 24 to 72 hours at room temperature to achieve cure. This process may be accelerated by curing in a thermal oven at 150° F. for 1 to 4 hours.
Radiation Curable System
The process steps for an exemplary radiation curable system are shown in FIG. 1, steps 2.a. through 2.g.
The process for making the coating is outlined in steps 1.a. through 1.c. The conductive polymer (polyaniline) is dispersed in a quantity sufficient to achieve desired potential along with a plasticizer (sulfonamide) into the resin base (polyurethane). The dispersion is accomplished by adding components to mixer, blender, attritor, or multi-agitator mixer and high shear mixing for roughly 15 to 30 minutes, maintaining a process temperature of 100° to 140° F.
Any remaining monomers, oligomers, additives, and photoinitiators are added to the polyaniline dispersion and low shear blended for an additional 15 to 30 minutes while maintaining a process temperature below 140° F.
The metal particles (aluminum flake or powder) are then added to the mixture in a quantity sufficient to achieve desired potential. Preferably, pure low oxidation aluminum flake or aluminum powder atomized and quenched in an inert environment is used. The aluminum can also be coated with stearic acid to preserve the deoxidized surface. Disperse and grind this mixture further utilizing the same equipment as in the previous steps. Grind and disperse an additional 30 to 45 minutes or until desired fineness of grind is achieved.
Step 2.d. is a packaging step. Because this coating system is UV curable, the packaging container must be opaque. Any plastic or polypropylene container that blocks ultraviolet light is suitable for packaging this material.
Step 2.e. is the surface preparation step. Again, as with the high solids system, any suitable means of preparing the substrate surface for coating may be utilized.
Step 2.f. is the application of the coating to the prepared substrate. The coating should be thoroughly mixed prior to coating by stirring or shaking. The coating may be applied by means such as dipping, brushing, rolling, spraying, or others already known in the art. Preferably, the coating is applied uniformly to all surfaces to a wet film thickness of 2-8 mils, which will correspond to an equivalent dry film thickness.
Step 2.g. is a curing step. The coating may be cured by exposure to ultraviolet light, beta radiation, electron beam, or in some instances infrared light. One source of UV radiation suitable for curing these coatings produces UV light in the 250 to 500 nanometer wavelength ranges, at a power of 300 watts/inch.
Powder Coat System
In FIG. 1, steps 3.a. through 3.i., the process steps required to produce a cathodic powder coating according to the invention are outlined.
Step 3.a. is a dry mixing operation that can be accomplished in a blender. The preferred method of mixing is utilizing a vertical blender for dry mixing powders. In this step, a premix is made of the powdered resin base, conductive polymer powder (polyariiline powder), plasticizer (sulfonamide), curing agents, additives, and metal particles (aluminum flake or powder). The conductive polymer and metal particles should be added in a quantity consistent with desired electrical potential. This step may be carried out utilizing high shear mixers or low shear mixers, such as ribbon cutters or tumble blenders. Mix for approximately 1 hour or until thoroughly mixed. The mixing preferably occurs at ambient temperatures. It is important that the process temperature does not exceed the cure temperature for the selected resin system.
Step 3.b. is a melt compounding and extruding process which is preferably accomplished in a reciprocating extruder. Melt compounding assures that all the additives, conductive polymer and metal particles are thoroughly dispersed in the molten resin base. Single screw reciprocating extruders are suitable for accomplishing this step. In the case of thermosetting coatings the temperature should be maintained 20°-50° F. above the melting point of the resin, but kept below 400° F. to avoid deteriorating the polyaniline.
In step 3.c. the melt is subjected to a cooling and flattening operation. The extrudate is cooled and flattened into a sheet about 0.005 inch thick by passing it through chilled nip rolls and cooled on an air or water cooling belt.
Step 3.d. is a primary grind operation preferably performed by a crusher at the end of a cooling line. The cooled, compounded sheet is quite friable and readily broken into chips measuring about 0.003-0.005 inches.
Step 3.e. is a fine grinding operation performed in a cryogenic mixing and grinding vessel. The cryogenic grinding serves three purposes. It allows the processing of low cure temperature thermoset powders, it promotes fracture of the aluminum, and it reduces oxidation of aluminum in the coating. The chips should be ground until a desired screen mesh is achieved. Typical mesh size is from +325 to −400.
Step 3.f. is a packaging step. Any suitable plastic bag or polypropylene container that seals the powder from moisture is acceptable. The finely ground powder coating may be discharged directly from the grinding vessel into the packaging container.
Step 3.g. is the process of surface preparation of the substrate. Mechanical means, such as a blast cabinet may be utilized. Additionally, any suitable means for surface preparation may be utilized.
Step 3.h. is the coating application step. The powder coating according to the invention may be applied using an electrostatic spray system, or other application means known in the art. If the powder coating is applied by thermal spraying, the substrate is usually preheated to a temperature slightly above the melting point of the powder.
Step 3.i. is the curing step. Cathodic thermoset powder coating systems are typically cured in thermal ovens. Curing temperatures below 400° F. should be used to prevent deterioration of the polyaniline in the powder. Cure is generally accomplished in 10 to 30 minutes. Cathodic thermoplastic powder coating systems that are thermally sprayed are allowed to cure utilizing residual heat produced by the thermal spray and preheated substrate.
Typical formulations for the coating systems according to the present invention are presented below. The following examples are intended to show various embodiments of the invention only and are not intended to limit the scope of the invention. All of the volume percentages listed are considered approximate.
EXAMPLE I
High Solids System (Two Part)
COMPONENT
TRADE NAME
VOLUME %
PART A
Polyamide Resin
39.00
Xylene
15.00
Polyaniline Powder
Versicon
7.00
Ethyl Benzene
5.00
Stoddard Solvent
5.00
1,2,4-Trimethylbenzene
2.00
n-butyl alcohol
10.00
Aluminum powder
AL-120
12.00
Ethyl toluenesulfonamide
Uniplex 108
5.00
100% Part A
PART B
Epon resin
65.00
Epoxy resin
13.00
Xylene
22.00
100% Part B
Equal volume amounts of Parts A and B are mixed immediately prior to application to the substrate.
EXAMPLE II
High Solids System (One Part)
COMPONENT
TRADE NAME
VOLUME %
Urethane Resin
51.00
Phenolic Resin
5.00
Polyaniline Powder
Versicon
7.00
Aluminum Powder
Al-120
12.00
Ethyl toluenesulfonamide
Uniplex 108
5.00
VM&P naptha
3.00
Xylene
3.00
Mineral Spirits
14.00
EXAMPLE III
UV-Radiation Cure System
COMPONENT
TRADE NAME
VOLUME %
Aliphatic urethane diacrylate
Ebercryl 4883
18.00
Isobornyl acrylate
SR 506
33.00
Polyaniline powder
Versicon
10.00
Acrylate polyester oligomer
Ebecryl 450
15.00
2-hydroxy-2-methyl-1-phenyl-1-
Darocur 1173
5.00
propanone
Hydroxycyclohexyl phenylketone
Irgacure 184
0.50
Metallic diacrylate
SR 9016
5.00
Aluminum Powder
AL-120
8.50
Ethyl toluenesulfonamide
Uniplex 108
5.00
EXAMPLE IV
Powder Coat System
COMPONENT
TRADE NAME
VOLUME %
Low density polyethylene
NA204
71.5
Polyaniline powder
Versicon
16.00
Ethyl toluenesulfonamide
Uniplex 108
2.5
Aluminum Powder
AL-120
10.00
The cured resin or binder, holds the aluminum or other anodic metal tightly in position to form the coating which adheres in electrical contact to the surface of the substrate. The polyaniline, or other inherently conductive polymer, that is dispersed into the resin base creates a conductive binder that promotes the galvanic action between the sacrificial metal anodes in the coating and the cathode surface.
The conductive binder acts as a conductor rather than a dielectric as is the case with other sacrificial organic coatings, thus allowing electrons to flow freely between anodic particles and cathode substrate.
The claimed improvements in corrosion resistance by use of the coating systems according to the invention are validated through markedly improved protection of the substrate when subjected to the salt spray test. Coated panels were intentionally scribed and tested in accordance with the procedure outlined in ASTM B117-95. The panels exhibited only slight surface oxidation at the damaged areas after 800+ hours in a salt spray chamber.
The ASTM B117 salt spray test utilized to test the corrosion resistance of this cathodic coating system comprises a salt fog chamber. The chamber is comprised of a fog chamber, salt solution reservoir, conditioned compressed air line, fog nozzle, specimen support racks, heater, and controller. The specimens are supported in racks at an attitude between 15 and 30 degrees from vertical parallel to the principal direction of horizontal flow of fog through the chamber. The salt solution is mixed at 5%+/−1% salt by weight with water meeting the requirements of ASTM 1193-91, Type III. The pH of the condensed fog is maintained between 6.5 and 7.2. Temperature in the chamber is maintained at 95° F, +2° or −3°. Relative humidity in the chamber is maintained at 95% to 98%.
The test specimens consist of standard 3×5 inch Q-panels, manufactured from cold rolled 1010 steel. The panels are coated utilizing the method described. The substrate is then intentionally scribed to base metal in an “X” pattern. The partially exposed base metal allows evaluation of the cathodic properties of the coating versus its performance as strictly an electrolytic barrier.
The test results indicate utilization of this coating method will extend the service life of metals.
The invention has been described with reference to preferred embodiment. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alternations in so far as they come within the scope of the appended claims or the equivalence thereof.
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A method of coating ferrous and nonferrous metal substrates that provides cathodic protection from corrosion by coating with inherently conductive polymers and sacrificial anodic metal particles. This method of coating is characterized by its conductivity and cathodic corrosion resistant qualities.
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FIELD OF INVENTION
[0001] The present invention relates to the field of membrane technology.
[0002] In one form, the invention relates to nanoporous polymeric membranes, particularly polyethersulphone membranes.
[0003] In another form, the invention provides nanoporous membranes suitable for liquid purification, particularly water purification.
[0004] In one particular aspect the present invention is suitable for use in filtration.
[0005] It will be convenient to hereinafter describe the invention in relation to water filtration however, it should be appreciated that the present invention is not limited to that use only and many other applications will be apparent to the person skilled in the art.
BACKGROUND ART
[0006] It is to be appreciated that any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the present invention. Further, the discussion throughout this specification comes about due to the realisation of the inventor and/or the identification of certain related art problems by the inventor. Moreover, any discussion of material such as documents, devices, acts or knowledge in this specification is included to explain the context of the invention in terms of the inventor's knowledge and experience and, accordingly, any such discussion should not be taken as an admission that any of the material forms part of the prior art base or the common general knowledge in the relevant art in Australia, or elsewhere, on or before the priority date of the disclosure and claims herein.
[0007] By definition, ultrafiltration membranes can reject particles and macromolecules of 2 to 100 nm in size. Ultrafiltration membranes are synthesised by various methods including phase inversion of polymer solutions, or phase separation of polymer blends.
[0008] Optimally, ultrafiltration membranes have high selectivity, high flux and excellent antifouling properties.
[0009] Nanoporous membranes are widely used in ultrafiltration processes for a diverse range of applications such as water treatment and food processing. Many polymers such as cellulose acetate, polyacrylonitrile copolymers, polysulphone, polyethersulphone and poly(vinylidene fluoride) are commonly used to produce membranes for these purposes. The nanoporous membranes typically possess an asymmetric porous structure which is typically achieved via a phase inversion method. High-flux membranes are highly desirable for high separation efficiency processes in order to reduce the process costs. Increasing membrane hydrophilicity by introducing hydrophilic groups on the active skin layer or throughout the membranes is an effective way to improve the membrane flux and other properties such as fouling resistance.
[0010] However, the water flux of existing polymer membranes is far below that of functional nanopores with fast water transport properties, such as biological water-channel proteins, protein-based membranes, and synthetic carbon nanotubes. For instance, as reported by Holt et al. (Science 2006 312(5776) p.1034) water transport rates through synthetic sub-2-nanometer carbon nanotubes are three orders of magnitude higher than theoretical values predicted by continuum flow models and this is attributed to slip flow at the inter-surface (Falk K et al. Nano Letter 2010 10(10) p.4067; Joseph S et al. Nano Letter 2008 8(2) p.452).
[0011] But these nanoporous systems with fast water transport properties are often chemically and mechanically unstable. Alternatively, it is often difficult to scale up their manufacture from bench-scale synthesis to commercial manufacture.
[0012] Accordingly, efforts have been made to overcome some of the deficiencies associated with existing polymer membranes to obtain improved characteristics, particularly improved hydrophilic properties. These typically fall into one of three categories; (i) direct materials modification before membrane preparation (pre-modification), (i) blending of a polymer matrix with a modifying agent in a casting solution during membrane preparation (additive), and (iii) surface modification after ultrafiltration membrane preparation (post-modification).
[0013] There have also been many attempts to increase the flux of ultrafiltration membranes however their application is often limited by intrinsic hydrophobic properties of polymer membranes.
[0014] There have been many attempts to prepare charged polymers with high thermal stability and high ionic conductivity such as quaternary phosphonium polymers. These attempts have focusses on synthesis of ion exchange membranes for fuel cells. However, these ion exchange membranes are not designed for applications such as water purification and are instead designed for use in either highly acidic or highly alkaline environment of fuel cells.
[0015] However, membranes for desalination processes have been constructed, by casting quaternary phosphonium polymer onto a piece of commercially available polyethersulphone substrate.
[0016] Several publications address the issue of obtaining a desired pore size in microporous phase inventions membranes. U.S. Pat. No. 6,267,916 (Meyering et al 1999) teaches a process of making microporous phase inversion membranes having any one of a plurality of different pore sizes derived from a master dope batch. U.S. Pat. 7,560,024 (Kools et al 2009), US 2003/0038391 (Meyering et al 2001) and U.S. Pat. No 6,056,529 (Meyering et al 2000) describe methods and systems for controlling pore size of microporous phase inversion membranes using hydrophilicity.
[0017] U.S. Pat. No. 6,071,406 (Tsou 2000) teaches a method of enhancing hydrophilicity of a hydrophobic membrane by adding a specified agent to the system used in casting.
SUMMARY OF INVENTION
[0018] An object of the present invention is to provide an ultrafiltration membrane having enhanced fluid flux, particularly water flux.
[0019] Another object of the present invention is to provide an ultrafiltration membrane with improved fluid permeability, particularly water permeability.
[0020] A further object of the present invention is to alleviate at least one disadvantage associated with the related art.
[0021] It is an object of the embodiments described herein to overcome or alleviate at least one of the above noted drawbacks of related art systems or to at least provide a useful alternative to related art systems.
[0022] In a first aspect of embodiments described herein there is provided an ultrafiltration membrane comprising:
[0023] (i) a first polymer, and
[0024] (ii) a second, charged polymer
[0000] wherein the first polymer and second polymer have different hydrophobicities.
[0025] Typically the first polymer (or matrix polymer) is selected from any convenient polymer membrane material. In a particularly preferred embodiment the first polymer is chosen from the group comprising polysulphone, polyethersulphone (PES), polyacrylonitrile, cellulose acetate or poly(vinylidene fluoride)
[0026] Typically the second polymer (or additive polymer) is selected from any convenient positively charged or negatively charged polymer which has a greater hydrophobicity (corresponding to lesser hydrophilicity) than the first polymer. Preferably the second polymer is a quaternary phosphonium polymer. In a particularly preferred embodiment the second polymer is chosen from the group comprising diphenyl(3-methyl-4-methoxyphenyl) tertiary sulphonium functionalized polysulphone, tris(2,4,6-trimethoxyphenyl) quaternary phosphonium-substituted bromomethylated poly(phenylene oxide), sulphonated poly(2,6-dimethyl-1,4-phenylene oxide) and tris(2,4,6-trimethoxyphenyl)polysulphone-methylene quaternary phosphonium chloride.
[0027] In a second aspect of embodiments described herein there is provided an ultrafiltration membrane comprising:
[0028] (i) a first polymer, and
[0029] (ii) a second, charged polymer having a different hydrophobicity from the first polymer,
[0000] and wherein the ultrafiltration membrane exhibits a charge density gradient.
[0030] In a third aspect of embodiments described herein there is provided an ultrafiltration membrane comprising:
[0031] (i) a first polymer, and
[0032] (ii) a second, charged polymer having a different hydrophobicity from the first polymer,
[0000] and wherein the ultrafiltration membrane exhibits a hydrophilicity gradient.
[0033] In a fourth aspect of embodiments described herein there is provided an ultrafiltration membrane comprising:
[0034] (i) a first polymer, and
[0035] (ii) a second, charged polymer having a different hydrophobicity from the first polymer,
[0000] and wherein the ultrafiltration membrane exhibits a hydrophilicity gradient and a charge gradient.
[0036] Typically the first polymer acts as a matrix and the second polymer is added to obtain a desired composition gradient. The ultrafiltration membrane of the present invention typically has a high degree of polarisation, such that it has distinct hydrophilic and hydrophobic ends. More particularly, the hydrophilicity/hydrophobicity exhibits a gradient between two ends, such as between the skin layer and the bottom layer of the polymer.
[0037] Preferably the ultrafiltration membrane has graded charge density. By contrast, ultrafiltration membranes of the prior art typically have a constant charge density, or a have charged active layer, not a gradient.
[0038] The ultrafiltration membrane of the present invention typically has water permeability 5 to 10 times greater than commercially available ultrafiltration membranes of the prior art (such as those described in Hoek, et al Desalination 2011, 283, p. 89-99 and Peeva et al, Journal of Membrane Science 2012, 390-391, 99-112). Typically the ultrafiltration membrane of the present invention has water permeability between 0.46 and 20.00 L/m 2 h kPa, more preferably between 10 and 16 L/m 2 h kPa.
[0039] Furthermore, the water flux is up to ten times greater than prior art membranes. Typically the ultrafiltration membrane of the present invention has water flux of between 25 and 2000 Lm −2 h −1 at a testing pressure of 100 kPa, preferably between 1,000 and 1,500 Lm −2 h −1 at a testing pressure of 100 kPa.
[0040] Without wishing to be bound by theory it is believed that high water flux through the membrane is due to the wetability and charge density gradients along the porous channels in the membrane, which gradients are produced by introducing a hydrophobic and charged polymer in the membrane formation process.
[0041] In a fifth aspect of embodiments described herein there is provided a method of making an ultrafiltration membrane comprising the step of combining a first polymer with a second charged polymer having a different hydrophobicity from the first polymer. Preferably the combination creates a hydrophilicity gradient and a charge gradient in the membrane.
[0042] The ultrafiltration membrane may be manufactured by a number of different methods. In a preferred embodiment there is provided a method of manufacturing the ultrafiltration membrane of the present invention including the step of phase inversion.
[0043] For example, owing to the difference in hydrophilicity/hydrophobicity, ultrafiltration membranes according to the present invention and having a gradient distribution of the second polymer can be produced by a phase inversion mechanism, resulting in a gradient distribution of charge and pore surface properties.
[0044] An organic solvent or combination of solvents is typically used in the manufacture of the ultrafiltration membrane and the specific organic solvent, or combination of solvents may depend on the types of polymers used in the membrane fabrication and the desired microstructure of the final membrane. For example, the organic solvent used for dissolving the first polymer (matrix) and the second polymer (additive) could be chosen from N-methyl-2-pyrrolidone, dimethylformamide, or mixtures thereof.
[0045] In a particularly preferred embodiment the method of manufacture includes the steps of phase inversion and the addition of quaternary-phosphonium polymer. For example, the polyethersulphone substrate and quaternary-phosphonium polymer may be dissolved in a solvent and then cast on a clean glass substrate.
[0046] Typically, when phase inversion is used the total polymer concentration in solution is between about 12 and 20 wt %. Typically, the amount of second polymer is up to 60 wt % of the total amount of polymer in solution.
[0047] Without wishing to be bound by theory it is believed that the simple phase inversion process comprising addition of second polymer into the casting solution enhances performance of the membrane by inducing hydrophilicity and charge distribution gradients.
[0048] Many synthetic polymeric membranes of the prior art are made by phase inversion processing, but do not produce hydrophilicity gradients and charge distribution gradients.
[0049] For example, the quaternary phosphonium polymers of the prior art such as those described in Wang et al ( Desalination 292, 119 (2012)) are constructed by casting on a piece of commercially available polyethersulphone substrate. Other methods of manufacture such as those described in U.S. Pat. No. 6,071,406 or U.S. Pat. No. 7,560,024 do not product a gradient change or hydrophilicity distribution.
[0050] Other aspects and preferred forms are disclosed in the specification and/or defined in the appended claims, forming a part of the description of the invention.
[0051] In essence, embodiments of the present invention stem from the realization that imparting a high degree of polarisation and distinct hydrophilic and hydrophobic ends to a membrane can impart improved functionality to the membrane.
[0052] Advantages provided by the present invention comprise the following:
the membranes have improved water permeability, typically 5 to 10 times higher water permeability than commercial polyethersulphone-based membranes with similar pore size; the membranes have improved filtration efficiency as compared with the prior art; the membranes can be readily prepared by known preparative techniques such as phase inversion; suitable preparative techniques for the membranes are well suited to large-scale production; and the membranes can be economically produced.
[0058] The ultrafiltration membrane of the present invention would have a number of applications including:
water treatment, such as desalination, purification and pre-treatment prior to desalination, and bio-separation, such as for the pharmaceutical industry, medical industry and bio-process engineering.
[0061] Further scope of applicability of embodiments of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure herein will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] The present invention may be better understood by those skilled in the relevant art by reference to the following description of embodiments and the accompanying drawings, which are illustrations only and do not limit the disclosure herein:
[0063] FIG. 1 illustrates the following:
[0064] FIG. 1 a —Molecular structure of tris(2,4,6-trimethoxyphenyl)polysulphone-methylene quaternary phosphonium chloride (TPQP-Cl);
[0065] FIG. 1 b —Molecular structure of polyether sulphone (PES);
[0066] FIG. 1 c —Schematic illustration of the formation of nanoporous polymer membranes in the phase inversion process: the solvent diffuses out of the cast polymer solution ( 1 ) comprising PES and TPQP-Cl into the non-solvent water ( 5 ) as indicated by the arrows while the non-solvent water ( 5 ) diffuses into the polymer solution ( 1 ) as indicated by the green arrows. This rapid exchange process leads to precipitation of PES and TPQP-Cl; the TPQP-Cl content increasing from the top surface to the bottom surface of the resulting membrane;
[0067] FIG. 1 d (i)—Cross-sectional scanning electron microscopy (SEM) image of a PES/TPQP-Cl composite membrane with 20% TPQP-Cl prepared from 15% PES/TPQP-Cl solution (denoted 15% PES/TPQP-Cl 8/2); FIG. 1 d (ii) is a cross-sectional SEM image of PES ultrafiltration membrane;
[0068] FIG. 1 e —SEM image of active surface, showing a nanoporous structure; and
[0069] FIG. 1 f —SEM image of bottom surface of the membrane.
[0070] FIG. 2 illustrates the following:
[0071] FIG. 2 a —is a graph of contact angle (o) against the percentage of TPQP-Cl added to the polymer, for the bottom layer ( 8 ) and the active layer ( 10 ) of a dried membrane according to the present invention;
[0072] FIG. 2 b —is a graph of actual TPQP-Cl content (determined by XPS) of the active layer ( 12 ) and bottom layer ( 15 ) of dried 15% PES membrane and 15% PES-TPQP-Cl membranes with different amounts of TPQP-Cl. The PES/TPQP-Cl membranes with a mass ratio of 9:1, 8:2, and 7:3 were prepared from a 15% polymer solution and denoted 15% PES, 15% PES/TPQP-Cl 9/1, 15% PES/TPQP-Cl 8/2, and 15% PES/TPQP-Cl 7/3, respectively.
[0073] FIG. 2 c —Schematic illustration of the hydrophobicity-hydrophilicity transition before and after hydration of charged groups of the PES/TPQP-Cl composite membrane, and contact angle change for the 15% PES/TPQP-Cl 8/2 membrane before hydration ( 16 ) and after hydration ( 18 ). The porous structure of the membrane is simplified as individual conical shaped channels between the active layer ( 20 ) and the bottom layer ( 22 ) of the membrane. The degree of hydrophilicity decreases from active layer to bottom layer in the dehydrated membrane; the opposite trend is seen in the hydrated membrane, which is more hydrophobic at the active layer. The inner surface of the channels is lined by the polysulphone backbone ( 24 ) in TPQP-Cl while the quaternary phosphonium group ( 26 ) of the TPQP-Cl projects to the inside of the channel. The quaternary phosphonium groups ( 26 ) of the hydrated membrane are effectively solvated ( 29 ) with water molecules.
[0074] FIG. 3 illustrates the following:
[0075] FIG. 3 a —illustrates water permeability and molecular weight cut-off (MWCO) of various polyethersulphone ultrafiltration membranes of the prior art and according to the present invention. The pore size of membrane was determined by molecular weight cut-off measurements. The following data on polymer membranes from recent literature are also included: 15% PES with 10% Pluronic F127 ( 31 ) (Susanto H & Ulbricht M, J. Membr.Sci 327, 125 (2009)), 16% PES with 2% polyvinylpyrrolidone (PVP) or 2% PVP and 5% 2-hydroxyethylmethacrylate ( 32 ) (Rahimpour A & Madaeni S S, J. Membr. Sci. 360, 371 (2010), 15% polysulphone-poly(ethylene oxide) random copolymer with 5% PVP ( 33 ) (Cho et al, J. Membr. Sci 379, 296 (2011)), 18% polysulphone (PSf), and 18% PSf with different additives ( 34 ) (Hoek et al, Delasination 283, 89 (2011)), commercial PES membranes and modified membranes ( 35 ) (Peeva et al, J. Membrane Sci 390, 99 (2012); polyacrylonitrile ( 36 ) (Boerlage et al, J. Membrane Sci 1971 (2002)), cellulose acetate-aminated poly(ether imide) ( 37 ) (Arockiasamy et al, Int. J. Polym. Mater. 57, 997 (2008)), and cellulose acetate-sulfonated polyetherimide ( 38 ) (Nagendran et al, Soft. Mater. 6, 45 (2008)), and polyvinylidene fluoride (PVDF)-co-hexafluoropropylene and modified PVDF membranes ( 39 ) (Wongchitphimon et al, J. Membrane Sci 369, 329 (2011)) and PES ( 40 ). The membranes according to the present invention were 15% PES/TPQP-Cl 8/2 ( 42 ), 16% PES/TPQP-Ci 8/2 ( 44 ), 15% PES/TPQP-Cl 7/3 ( 46 ), 13% PES/TPQP-Cl 8/2 ( 48 ) and 15% PES/TPQP-Cl 9/1 ( 50 ).
[0076] FIG. 3 b —Polyethylene glycol (PEG) molecular weight cut off curves of 15% PES and the following PES/TPQP-Cl membranes according to this invention: 15% PES ( 52 ), 15% PES/TPQP-Cl 9/1 ( 54 ), 15% PES/TPQP-Cl 8/2 ( 56 ), 15% PES/TPQP-Cl 7/3 ( 58 ), 16% PES/TPQP-Cl 8/2 ( 60 ), 18% PES/TPQP-Cl 8/2 ( 62 ).
[0077] FIG. 4 includes schematic representations of the cross-sections of ultrafiltration membranes as follows:
[0078] FIG. 4 a —asymmetrically porous structure of a typical ultrafiltration membrane of the prior art;
[0079] FIGS. 4 b to 4 f —existing membrane structures including non-charged membrane ( FIG. 4 b ), positively charged membrane surface ( FIG. 4 c ), negatively charged membrane surface ( FIG. 4 d ), uniformly distributed positive charge ( FIG. 4 e ), and uniformly distributed negative charge ( FIG. 4 f );
[0080] FIGS. 4 g to 4 j —structures of ultrafiltration membranes according to the present invention having gradient charge distribution and gradient hydrophilicity/hydrophobicity.
[0081] FIG. 5 illustrates the results of contact angle testing of membranes constructed of polyethersulphone ( FIG. 5 a ) and tris(2,4,6-trimethoxyphenyl)polysulphone-methylene quaternary phosphonium chloride ( FIG. 5 b ).
DETAILED DESCRIPTION
[0082] The present invention provides nanoporous polymer membranes that can provide fast water transport by creation of a hydrophilicity gradient coupled and/or a charge density gradient. The membrane may be manufactured using conventional techniques such as a phase inversion process.
[0083] The enhancements in water transport rates associated with the membranes of the present invention over continuum flow model predictions are very close to those observed in carbon nanotubes. The membranes are produced by incorporating a hydrophobic and charged polymer in the membrane fabrication process. In particular, tris(2,4,6-trimethoxyphenyl)polysulphone-methylene quaternary phosphonium chloride (TPQP-Cl) with an intrinsic contact angle of 94° (measured from dense TPQP-Cl films) is chosen as an additive in the preparation of polyethersulphone (PES) membranes (PES has an intrinsic contact angle of 79°, measured from dense PES films) ( FIG. 5 a, FIG. 5 b ). Because TPQP-Cl is more hydrophobic than PES, it migrates to the substrate due to the difference in the de-mixing rate during the phase inversion process, leading to an increase in TPQP-Cl content from the top active layer to the bottom supporting layer ( FIG. 2 c ).
[0084] Scanning electron microscopy (SEM) images show that the PES/TPQP-Cl membrane exhibits a typical asymmetrical microstructure with a thin active skin layer and a finger-like macroporous supporting layer ( FIG. 1 d (i) & (ii), FIG. 1 e ).
[0085] The water contact angle of dried PES and PES/TPQP-Cl membranes is illustrated graphically in FIG. 2 a. The PES and PES/TPQP-Cl membranes with different PES/TPQP-Cl mass ratios (9:1, 8:2, and 7/3) prepared from 15% polymer solutions were denoted 15% PES, 15% PES/TPQP-Cl 9/1, 15% PES/TPQP-Cl 8/2, and 15% PES/TPQP-Cl 7/3, respectively.
[0086] The contact angle of the active layer remains almost the same at different TPQP-Cl loadings whereas the contact angle of the bottom surface increases significantly from 60° to 90° when the TPQP-Cl/PES ratio increases to 2:8, and then slightly decreases to 84° at a 30 wt % TPQP-Cl loading. The small decrease in contact angle of the bottom surface from 15% PES/TPQP-Cl 8/2 to 15% PES/TPQP-Cl 7/3 can be explained by the fact that the former has a somewhat rougher bottom surface than the latter.
[0087] The TPQP-Cl concentration gradient across the dry membrane cross section is confirmed by X-ray photoelectron spectroscopy (XPS) ( FIG. 2 b ). Note that the elemental composition obtained from XPS is the average value within a few microns thickness from the surface due to the effect of X-ray penetration. Interestingly, as compared with conventional membranes, a reverse hydrophilicity gradient (the bottom supporting layer is more hydrophilic than the active layer) is ultimately produced due to hydration of charged groups of TPQP-Cl.
[0088] The contact angle data shown in FIG. 2 c demonstrate that the hydrophobicity-hydrophilicity transition occurs in PES/TPQP-Cl composite membranes with a gradient distribution of TPQP-Cl inverting between the dry state and wet state. The wetability of the active layer does not change much before and after hydration. However, in wet PES/TPQP-Cl membranes, the bottom surface becomes much more hydrophilic, clearly indicating a hydrophilicity gradient (coupled with a charge density gradient) from the active layer to the bottom supporting layer. By contrast, the contact angle of active layer of wet 15% PES control membrane is 58.5°, which is close to that of its bottom surface (59.3°), confirming that there is no wetability gradient present in the membrane.
[0089] The water permeability, and pore size of the PES and PES/TPQP-Cl membranes studied in this work are presented in FIG. 3 a. The polyethylene glycol (PEG) molecular weight cut off (MWCO) curves of these membranes are shown in FIG. 3 b, and the MWCO at 90% rejection rate was used to calculate the pore size of the membrane. Without any additive, 15% PES control membranes have a water permeability of 0.46 L/m 2 h kPa. All membranes with TPQP-Cl (15% PES/TPQP-Cl) show remarkably higher water permeability than 15% PES membrane; and 15% PES/TPQP-Cl 8/2 membrane exhibits the highest water permeability (14.6 L/m 2 h kPa), which is 32 times higher than that of 15% PES membrane. PES/TPQP-Cl membranes prepared from different concentrations of polymer casting solutions show different permeation properties.
[0090] Comparison of the water permeability and the pore size of skin layer for the membranes prepared from casting solutions with 16% and 18% and a fixed PES/TPQP-Cl mass ratio of 8:2 (denoted 16% PES/TQPQ-Cl 8/2 and 18% PES/TPQP-Cl) are shown in FIG. 3 a. With increasing polymer concentration, the pore size of skin layer slightly decreases (Table 1) while the pore size and porosity of the bottom layer (surface) decreases more significantly based on SEM observations. The water permeability drops only 2% when the polymer concentration increases from 15% to 16%, but it decreases by 41% when the polymer concentration rises from 16% to 18%. It is noted that a dense skin layer was formed from 18 wt % PES casting solution, and this PES membrane was impermeable to water at a testing pressure of 450 kPa.
[0091] As shown in FIG. 3 b, the PES/TPQP-Cl membranes have narrow MWCOs, and maintain excellent separation properties at high water permeabilities. For comparison, the water permeability versus pore size of typical polymer ultrafiltration membranes recently reported in the literature is included in FIG. 3 a. It is clear that the water permeabilities of PES/TPQP-Cl membranes greatly exceed other membranes with similar pore sizes.
[0092] The measured water fluxes are 35 to 57 times higher than those of the no-slip hydrodynamic flows from the Hagen-Poiseuille model. The enhancement can be explained in terms of slip length, which is an extrapolation of the extra pore radius required to give zero velocity at a hypothetical pore wall (the boundary condition for Hagen-Poiseuille flow). The estimated minimum slip lengths are summarized in Table 1 which records comparisons of experimental water fluxes with continuum flow model predictions. Values for carbon nanotubes and polycarbonate membranes from Han et al ( J. Membrane Sci, 2010 358(1-2) p. 142-149) are included as a reference. Pore diameters were calculated from PEG molecular weight cut-off values at 90% rejection rate ( FIG. 3 b ). Pore density values were determined by counting the number of pores on 2.5 μm×2.0 μm high resolution SEM images of the active surfaces of membranes.
[0000]
TABLE 1
En-
hancement
Mini-
Pore
Thick-
over non-
mum
Pore
number
ness of
slip, hydro-
slip
size
density
active
dynamic
length
Sample
(nm)
(cm −2 )
layer
flow
(nm)
15% PES
14.3
3.6 × 10 9
500 nm
2.4
3.0
15% PES/
15.7
~1.0 × 10 10
36
69
TPQP-
CI 9/1
15% PES/
19.2
42
99
TPQP-
CI 8/2
15% PES/
19.2
27
62
TPQP-
CI 7/3
16% PES/
16.5
57
117
TPQP-
CI 8/2
18% PES/
16.1
35
67
TPQP-
CI 8/2
Double-walled
1.3 to
≦0.25 × 10 12
2 μm
560 to
140 to
carbon
2.0
8400
1400
nanotubes
Polycarbonate
15
6 × 10 8
6 μm
2.1
5.1
[0093] As TPQP-Cl content varies from 10 to 30%, the slip length varies from 62 to 117 nm. In contrast, the PES control membrane has a slip length of 3.0 nm, which is comparable with the polycarbonate membrane with a pore size of 15 nm. Surprisingly, the slip lengths of our PES/TPQP-Cl membranes are very close to those of double-walled carbon nanotube membranes (Table 1), which are well recognized nanochannels with enhanced water permeability. Molecular dynamic modelling revealed that increasing nanotube diameter leads to a reduction in slip length, and the slip length for a carbon nanotube with a pore diameter of around 20nm is 54-67 nm, which is comparable with polymer membranes of the present invention.
[0094] The extensive molecular dynamic (MD) studies on CNT membranes have identified that the atomically smooth solid walls and the hydrophobic nature of CNTs are the key factors for the large slip length. But it is highly unlikely that our hydrophilic polymer nanopores would have a similar smoothness to CNTs, although the tortuous pores may exhibit a certain degree of smoothness locally arising from the arrangement of hydrated aromatic quaternary phosphonium groups on TPQP-Cl. Therefore, it seems that the pore surface smoothness is not responsible for the high water permeability in our experiments.
[0095] Positron annihilation lifetime spectroscopy (PALS) results show the addition of TPQP-Cl does not affect the Å-sized free volumes of these polyethersulphone membranes. High water flux should only occur in the nanoporous channels (14-20 nm in diameter) of the membranes. In addition, the small increase in the pore size and pore density of the active layer and the moderate increase in the porosity of supporting layer may also contribute to enhanced water flux.
[0096] A hydrodynamic model of a flow in a cone to describe the water transport in membranes of the present invention. The changes in pore size, pore number density, and thickness of the membranes only resulted in up to 5.8 times enhancement in water flux through the PES/TPQP-Cl membrane, which is far smaller than the observed 32 times enhancement. Therefore the change of membrane microstructure only plays a minor role in promoting water permeation through our PES/TPQP-Cl membranes.
[0097] The fast water transport through the PES/TPQP-Cl membranes can be mainly attributed to the unique combination of pore surface wettability gradient and charge density gradient. To examine the effect of surface charge, an electrolyte solution was used to electrostatically shield the pore surface charge in the filtration process. The flux of 1 M NaCl aqueous solution through 15% PES/TPQP-Cl 8/2 membrane was found to be around 50% lower than the pure water flux; whereas the flux of 1 M NaCl aqueous solution through 15% PES control membrane was similar to the pure water flux.
[0098] This observation strongly suggests that the shielding effect caused by the accumulated Na + and Cl − ions on the charged pore surfaces leads to a large increase in the water flow resistance. Therefore, this experimental result demonstrates that the surface charge gradient plays a crucial role in the remarkably high water permeability observed for the PES/TPQP-Cl membranes. In addition, the hydrophilicity gradient in the membranes of the present invention should also contribute to the enhanced water flow by promoting directional water movement.
[0099] The membrane of the present invention and its characterising properties can also be described with reference to FIG. 4 . FIG. 4 shows asymmetrically porous structures of a typical ultrafiltration membrane, existing membranes with non-charged porous structure and uniform charge distribution, as compared with membranes according to the present invention which have gradient charge distribution and gradient hydrophilicity and hydrophobicity.
[0100] In membranes of the prior art either positive charge or negative charge is uniformly distributed on the membrane surface or throughout the membrane ( FIGS. 4 b to 4 f ).
[0101] By contrast, the membrane structure of membranes according to the present invention ( FIGS. 4 g to 4 j ), both the charge and hydrophilicity/hydrophobicity exhibit gradient distribution from the skin layer towards the bottom layer. Without wishing to be bound by theory it is believed that because of these unique structures, the ultrafiltration membranes of the present invention show extraordinarily high water flux.
PREPARATIVE EXAMPLE
[0102] Ultrafiltration membranes according to the present invention were prepared by phase inversion. Quaternary-phosphonium polymer ( FIG. 1 a ) (at least 40 wt % of total polymers) and polyethersulphone ( FIG. 2 b ) (up to 60 wt % of total polymers) was dissolved in DMF with stirring. The resulting polymer solutions without air bubbles were cast using a micrometer film applicator onto a clean glass plate to a thickness of 100 to 500 micron.
[0103] The membrane was produced in a coagulation bath filled with double deionised water or other solvents, followed by washing in double deionised water. The resulting membranes were soaked in deionised water for future use.
[0104] Contact angle measurements using a drop of 5 μL water revealed that positively charged TPQP-Cl is more hydrophobic than PES. ( FIG. 5 )
[0105] The concentration of polymer solution and ratio of PES/TPQPCl can be varied to fabricate the ultrafiltration membranes with different filtration properties. For example, use of a 15 wt % polymer solution with a PES/TPQP-Cl mass ratio of 80/20 is used, the resulting ultrafiltration membrane has a water flux of 1252 Lm −2 h −1 (LMH) at a testing pressure of 100 kPa, which is about 45 times the water flux of pure PES membrane (25 LMH at 100 kPa). The molecular weight cut off (MWCO) of pure PES membrane is about 75000 (pore size of about 14.4 nm), whereas the PES-TPQP-Cl membrane exhibits the highest water flux, and a MWCO of 135000 (pore size of about 19.2 nm).
[0106] FIGS. 1 d (i) and 1 d (ii) compares the microstructure of the PES-TPQP-CL membrane with PES. Both membranes show asymmetric structures consisting of a top thin selective skin layer, a thick bottom layer with fully developed macro-voids. With an addition of TPQP-CL, macrovoids at the bottom increased in number and size.
[0107] Table 2 lists the contact angle of PES and PES-TPQP-Cl ultrafiltration membranes. As listed in Table 2, the hydrophobicity of the top skin layer is similar to that of the bottom layer in the PES ultrafiltration membrane.
[0000]
TABLE 2
Top surface
Bottom surface
contact angle
contact angle
Ultrafiltration Membrane
(°)
(°)
PES membrane
59.4 ± 3.3
61.3 ± 4.3
PES membrane with 20%
58.6 ± 2.8
89.6 ± 3.1
TPQP-CI
[0108] However in PES-TPQP-Cl membrane the skin layer is more hydrophilic than the bottom layer. In addition XPS elemental analysis of PES-TPQP-Cl membrane shows that the skin layer contains 0.33 mol % P, and the bottom layer has 0.48 mol % P (ie 45.5% increase) indicating that the charge density gradually increases from the skin layer to the bottom layer.
[0109] It is because the fabrication of PES-TPQP-Cl membrane, PES-TPQP-Cl is more hydrophobic than PES, and it will be pushed from the skin layer to the bottom layer during solvent exchange with water from the top surface in the phase inversion process. Without wishing to be bound by theory it is believed that this unique gradient structure causes a dramatic enhancement in water flux due to large differences in surface charge and surface tension between the skin layer and the bottom layer.
[0110] After the PES-TPQP-Cl membrane was ion-exchanged with 1M KOH solution, the resulting PES-TPQP-OH − ultrafiltration membrane had a water flux of 1095 LMH with a testing pressure of 100 kPa, which was slightly lower than that of PES-TPQP-Cl membrane. While the PES-TPQP-Cl membrane was treated in 1M NaF solution to ion-exchange Cl − with F − , the resulting PES-TPQP-F membrane exhibited a water flux of 1303 LMH at a testing pressure of 100 kPa, which was slightly higher than that of PES-TPQP-Cl.
[0111] The water permeability and MWCO of these membranes are plotted in FIG. 6 in comparison with ultrafiltration membranes of the prior art. In this figure the water permeability and MWCO of all the membranes were determined using the same testing method. There is a trade-off between the water permeability and the pore size of the top skin layer of the membranes. As clearly shown in FIG. 3 a, PES-TPQP-Cl, PES-TPQP-OH and PES-TPQP-F membranes show extraordinarily high water permeability as compared with all other membranes. Therefore our new membranes have great potential to largely improve filtration efficiency and reduce the costs of ultrafiltration processes in a wide range of applications including clean water production, wastewater treatment, food processing and bioprocessing.
[0112] While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). This application is intended to cover any variations uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth.
[0113] As the present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. The described embodiments are to be considered in all respects as illustrative only and not restrictive.
[0114] Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and appended claims. Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced. In the following claims, means-plus-function clauses are intended to cover structures as performing the defined function and not only structural equivalents, but also equivalent structures.
[0115] “Comprises/comprising” and “includes/including” 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. Thus, unless the context clearly requires otherwise, throughout the description and the claims, the words ‘comprise’, ‘comprising’, ‘includes’, ‘including’ and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.
|
An ultrafiltration membrane comprising: (i) a first polymer, and (ii) a second, charged polymer wherein the first polymer and second polymer have different hydrophobicities.
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BACKGROUND OF THE INVENTION
The present invention generally relates to a display pattern preparing system and in particular a system for forming picture element series data for raster from data for contour control for the sake of formation and display of picture images.
In the conventional art, a master for printed wiring board wiring is drawn by obtaining data of contour control from a design drawing and then moving in accordance with the data a mechanical head such as of an X-Y plotter in a vector fashion over a plane on which the master is to be formed. This method, however, is defective in that several tens of hours are required for drawing a master of a large area and a high density.
Although the time may be radically shortened if a master is drawn and displayed by way of raster-scanning using an electro-optical means, there is required a system for forming picture elements series data for raster from the contour control data. Disclosed in U.S. Pat. No. 3,812,491 to C. G. Barraclough entitled "Raster-scanned Display Devices" is a device wherein an image is formed electrically and a video signal corresponding to the image is supplied to a raster-scanned display unit such as CRT. This device, however, requires calculation in terms of vectors to produce a picture element series data and has no storage function to memorize a given pattern, thus giving rise to prolonged calculations. Especially, for complicated patterns, the device of extremely sophisticated is required. Another prior art is known in which a pattern to be displayed is directly stored in a memory. Obviously, this prior art requires a large number of memories to deal with a complicated pattern and hence becomes expensive.
SUMMARY OF THE INVENTION
The present invention has for its prime object to provide a display pattern preparing system for forming picture element series data for formation and display of picture images by raster scanning which is simplified to be adaptive to universal usage.
Another object of the present invention is to provide the manner of normalization of a pattern for formation of picture element series data.
According to this invention, there is provided a display pattern preparing system comprising:
a fixed pattern memory storing, as a registered configuration data, the length of a segment by which a fixed pattern of a prescribed configuration and area crosses a scanning line in the primary direction of scanning;
an analogous pattern memory storing, as parameters, a reference position data representative of a reference point for a portion of an analogous pattern through which the analogous pattern overlaps the scanning line, said analogous pattern being defined as a pattern whose configuration is analogously variable, a distance data representative of the length of said portion of the analogous pattern, and a height data representative of a width of the analogous pattern in the auxiliary direction of scanning;
means for reading out said data from said fixed pattern memory and said analogous pattern memory;
means for preparing a position data for display of a pattern designated by the read-out data; and
means for transmitting said position data to a display unit.
In accordance with a preferred embodiment of the invention, a system for forming picture element series data comprises:
a first configuration description data memory unit for storing configuration description data groups aligned in the order of their generation in the auxiliary direction of scanning;
a second configuration description data memory unit for storing configuration description data groups which are being continuously processed;
a memory control unit for controlling configuration description data memory units;
a registered configuration data memory unit for storing registered configuration data groups indicating lengths of a prescribed configuration by which the prescribed configuration crosses the raster;
a cross data point formation unit which receives configuration description data from said first or second configuration description data memory unit and refers to the registered configuration data stored within said registered configuration data memory unit to form a cross point data representative of the position where the scanning raster crosses the configuration corresponding to said configuration description data;
a continuation judging unit which judges whether or not said configuration crosses the ensuing raster and processes configuration description data which is the basis for said configuration for continuation, when said configuration crosses the ensuing raster, to cause this continuation data to be stored in the second configuration description data memory unit;
a picture element series data formation unit which forms a picture element series data based on the cross point data received from said cross point data formation unit;
a picture element series data memory unit for storing picture element series data associated with at least one scanning line of the raster; and
a supply unit for supplying the picture element series data associated with the one scanning line which has been formed in said picture element series data memory unit to a subsequent processing unit.
In accordance with another preferred embodiment of the invention, a system for forming picture element series data comprises:
a first figure description data memory unit for storing figure description data groups aligned in the order of their generation in the auxiliary direction of scanning;
a second figure description data memory unit for storing figure description data being continuously processed;
a memory control unit for controlling figure description data memory units;
a registered configuration data memory unit for storing registered configuration data groups indicating lengths of portions of a prescribed normalized configuration by which the prescribed normalized configuration crosses the raster;
a cross point data formation unit which receives figure description data from said first or second figure description data memory unit and refers to the registered configuration data of said registered configuration memory unit to form a cross point data representative of the position where the scanning raster crosses the configuration corresponding to said figure description data;
a continuation judging unit which judges whether or not said configuration crosses the ensuing raster, and when having judged that said configuration crosses the raster, processes figure description data for continuation and causes the same to be stored in the second figure description data memory unit;
a picture element series data memory unit for storing the picture element series data associated with at least one scanning line of the raster;
a memory selection unit for forming a signal which selects from said picture element series data memory unit memory elements corresponding to picture elements between two cross points of said cross point data;
a tone control unit for causing tone data in the figure description data to be stored in the memory elements selected by said memory selecting unit; and
a supply unit for supplying the picture element series data associated with one scanning line which has been formed in said picture element series data memory unit to a subsequent processing unit.
In accordance with still another preferred embodiment of the invention, a system for forming picture element series data comprises:
a first configuration description data memory unit for storing registered configuration description data groups aligned in the order of their generation in the auxiliary direction of scanning and configuration description data descriptive of a parallelogram of which one set of opposing sides is parallel to the primary direction of scanning and a right angle triangle of which two sides subtending right angles are parallel to the primary or auxiliary direction of scanning;
a second configuration description data memory unit for storing configuration description data groups being continuously processed;
a memory control unit for controlling said two memory units;
a registered configuration data memory unit for storing registered configuration data groups indicating relative position of the points where the registered configuration crosses the raster;
a cross point data formation unit which receives configuration description data from said first or second memory unit and refers to registered configuration data in said registered configuration data memory unit as the need arises to form a cross point data representative of absolute position where the scanning raster crosses the configuration represented by said configuration description data;
a continuation judging unit for judging whether or not said configuration crosses the ensuing raster and when having judged that said configuration crosses the raster, processes said configuration description data for continuation and causes the same to be stored in the second configuration description data memory unit;
a picture element series data memory unit for storing the picture element series data associated with at least one scanning line of the raster;
a memory selecting unit for selecting memory elements corresponding to picture elements between the two cross points of said cross point data from said picture element series data memory unit to cause a signal indicating that the figure exists to be stored; and
a supply unit for supplying the picture element series data associated with one scanning line which has been formed in the picture element series data memory unit to a subsequent processing unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic representation showing a typical pattern to be processed in accordance with the invention;
FIGS. 2A and 2B are diagrammatic representations useful in explaining formation of picture element series data or normalized patterns;
FIG. 2C shows a format of registered pattern data storage;
FIG. 2D is a diagrammatic representation useful in explaining formation of picture element series data of a composite pattern of normalized patterns;
FIG. 2E shows a format of configuration description data storage;
FIG. 3A shows a storage format in a fresh configuration description data memory unit;
FIGS. 3B to 3H show the manner of controlling in a configuration description data memory unit;
FIG. 4 is a diagrammatic representation useful in explaining the manner of arrangement of configuration description data in respect of scanning lines of the raster;
FIG. 5 is a block diagram of one embodiment of the invention;
FIGS. 6 and 7 are block diagrams showing details of FIG. 5;
FIG. 8 is a diagrammatic representation showing a complicated pattern to be processed in accordance with the invention;
FIGS. 9 and 10 show the manner of normalization of the pattern of FIG. 8;
FIG. 11 is a block diagram of another embodiment of the invention;
FIGS. 12A to 12E are diagrammatic representation useful in explaining the manner of overlapping in accordance with the invention;
FIGS. 13A and 13B show the manner of normalization of general patterns;
FIGS. 14A and 14B are diagrammatic representations of normalized configurations for the patterns in FIGS. 13A and 13B;
FIG. 15 illustrates in sections (1) through (5) the manner of formation of picture element series data of normalized patterns for the patterns in FIGS. 13A and 13B, and in sections (1)' through (5)' storage format of respective normalized patterns;
FIG. 16 is a block diagram of still another embodiment of the invention; and
FIG. 17 is a block diagram showing details of FIG. 16.
DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described with reference to the accompanying drawings, and terms used hereinafter are annotated for reference purposes. The concepts of "figure", "configuration" and their "normalization" used herein should first be discussed. "Figure" is meant to have "shape" and "color" and used in the normal sense of the word, whereas "configuration" is a concept representing a pattern removed of color and means "shape" defining a contour of the "figure". In the present invention, "figure" is disassembled into several "normalized figures", and picture element series data formed in respect of such "normalized figures" are assembled to obtain the picture element series data for the original "figure". The term "normalization" used herein means to disassemble the "figure" into several "partial figures" each having a contour which intersects one scanning line at not more than 2 points, and a partial figure thus obtained in a "normalized figure". The partial figure has a "normalized configuration" which is a unit for processings in the present invention as will be described later.
FIG. 1 shows a master for a printed wiring board as a typical example of a figure group to be drawn by using picture element series data formed by a system for forming picture element series data according to the present invention. Three figures 101, 102 and 103 are shown in the figure which are selected to simplify explanation of the process of forming the picture element series data according to the present invention.
In the process of formation of picture element series data according to the present invention, formation of the cross point data which is generally classified into two modes plays an important role, and thus a description thereof will first be given.
The first mode is a computing mode. FIG. 2A is a diagram to explain the computing mode wherein arrows 201a and 202a indicate primary and auxiliary directions of scanning, respectively denoted by "X" and "Y", in Cartesian coordinates. FIG. 2A shows a part of the contour of the figure 101 in FIG. 1. By taking a rectangular portion 203a indicated by a solid line as a configuration, the computing mode will be detailed. It will be easily understood that the rectangular configuration 203a is defined by coordinates (X a , Y a ) of a point where the raster crosses the configuration first and by increments ΔX a , ΔY a from this point. As the picture element series data formation proceeds to the point where the picture element series data for Y a -th scanning line is to be formed, this scanning line crosses the rectangular configuration 203a and it becomes necessary to obtain a cross point data. Assuming that the cross point data are X s and X E (provided X s ≦X E ), it holds that X s =X a , and X E =X a +ΔX a . Thus, the cross point data formation continues until the picture element series data is formed for (Y a +ΔY a -1)-th scanning line. The mode in which the cross point data is formed by computing only the contour control data defining the configuration (in this case, X a , Y a , ΔX a , ΔY a ) is called the computation operation mode. In order to form the cross point data for the rectangular configuration 203a shown in FIG. 2, it is also necessary to provide data which indicates that this is a rectangular configuration to be processed by the computation data (hereinafter referred to as mode data) in addition to the aforementioned data X a , Y a , ΔX a and ΔY a . Assuming that the mode data thus provided is O R , a set of data (O R , X a , Y a , ΔX a , ΔY a ) is called configuration describing data (hereinafter abbreviated as CDD) for the rectangular configuration 203a.
The second mode is a retrieval mode which is used in dealing with a prescribed configuration. FIG. 2B is a diagram to explain the retrieval mode wherein a circular configuration 204B is a configuration on which the figure 102 in FIG. 1 is based. As in the case of the computation mode, when coordinates at a point where the raster first crosses the circular configuration 204b are plotted (X b , Y b ), the cross point data formation begins in respect of the circular configuration from the point when the formation of picture element series data for Y b -th (y b =Y a as far as FIG. 1 is concerned) scanning line starts. When the radius for the circular configuration 204b is given in addition to X b , Y b the circular configuration is defined and the cross point data is obtainable by computation. The computation in this case becomes much more complex compared to that for the rectangular configuration 203a discussed above, and encounters difficulties in the electric circuits and the computation time required therefor. In order to avoid such difficulties, there is provided a memory to store registered configuration data indicating length of segments by which the scanning lines intersect the contour of the circular configuration 204b from a certain address (expressed as storage start address T), the cross point data for (Y b +n)-th scanning line, for example, is sought by reading out dnL, dnR from (T+n) address (in this case dnL=dn R because of the circular configuration) to determined X s =X b -dnL, and X E =X b +dn R . This method is particularly effective for the instances where geometrically congruent configurations appear frequently as it stores the registered configuration data in respect of such configurations. Thus, the mode in which the registered configuration data is used to seek the cross point data is called the retrieval mode. When the mode data is termed R, the CDD for the circular configuration includes R, X b , Y b , ΔY b and T. The mode data in the retrieval mode is the same irrespective of type of the configurations.
There are instances where both the computation mode and the retrieval mode described above may conveniently be used to seek the cross point data for one figure as shown in FIG. 2D. In this figure, there are shown two configurations to create the figure 103 of FIG. 1, namely a circular configuration 205d and a rectangular configuration 206d. The retrieval mode is used for the circular configuration 205d while the computation mode is used for the rectangular configuration 206d in order to form the cross point data, and they are assembled, partly overlapped, in the course of the picture element series data formation to obtain the picture element series data for the figure 103 of FIG. 1. Formation of the picture element series data will be discussed later, but it is apparent that when the computation mode and the retrieval mode are suitably used, the cross point data are efficiently formed.
It is to be understood that the master of the printed wiring board as exemplified in FIG. 1 is merely illustrated as a typical example and that there are various other figures conceivable and accordingly various other configurations which are used to form such other figures are also conceivable. Since it complicates the explanation of the fundamental concept of the present invention to go into details of the formation process of the cross point data in respect of every conceivable figure, description is limited only to the typical configurations of rectangle and circle. In practice, a rectangular configuration which is not in parallel to the scanning direction is rather often encountered and the process of forming the cross point data in such a case will be explained later referring to a subsequent embodiment of the present invention.
The foregoing description teaches the necessity of formation of the CDD groups for respective scanning lines from the contour control data in order to form the picture element series data by the system of the present invention. It will also be understood that respective CDD groups be arranged in the order of generation of the scanning lines in the auxiliary direction of scanning, or that a value of Y at a point where the raster first crosses the configuration be used as the key to sort out the data. Preparing CDD groups and sorting operation are not detailed here since they may be realized by software for ordinary universal computers.
FIG. 2E shows an example of CDD group stored in the order of generation in respect of one scanning line based on configurations used heretofore in description. Four of the configurations 203a, 204b, 205d, and 206d are supposed to cross the same scanning line for instance the 1,000th scanning line, for the first time. This means that all the values of Ya, Yb and Yd are equal. Then, arrow 104 in FIG. 1 is representative of the 1,000th scanning line. The CDD group of the four configurations starting from the 1,000th scanning line and the manner in which they are stored are as shown in FIG. 2E. As shown in the figure, the storage is assumed to have started from an address M. At the address M is stored a data or value "1,000" which indicates that the CDD group starting from the 1,000th scanning line is stored. Subsequently, another data of the CDD group is sequentially stored at the next M+1 address onward. It is to be noted that the form of CDD shown in the foregoing description of the two modes upon formation of the cross point data and that of FIG. 2E are slightly different. in FIG. 2E showing the manner in which data of CDD group are stored, the Y value of 1,000 representative of the position where the raster first crosses the configuration is used as a sorting key which is stored in the beginning as a common value (to be referred hereinafter as the formation start position data), and is not included in the individual CDD groups. In this example, the radius of the two circular configurations 204b and 205d is assumed to be equal, or they are deemed congruent geometrically, so that the same storage start address T is stored at addresses M+7 and M+11. At the addresses M+17 to M+20 are stored pseudo CDD, which indicates the end of CDD group related to a certain scanning line. Since ΔY a at address M+4, ΔY b at M+8, ΔY d at M+12, and ΔY d at M+16 are the data to represent extension of the figure in the auxiliary direction of scanning, they are related not only to the associated scanning line but also to the ensuing scanning lines (1,000st line, 1,002nd line, . . . in this example), and these data are used for judging "Continuation" which will be described later but in brevity, ΔY a (address M+4), for example, is used to judge whether or not the data O R (address M+1), (M+2) and ΔX a (M+3) concerning the 1,000th scanning line are necessary for the 1,001st line, 1,002nd line and so on.
In addition to the description given of the CDD group, it is necessary to explain two memory units for storing such FDD groups and the control therefor. The CDD groups stored in the manner shown in FIG. 2E are sequentially read out for starting processing from the one in which the order of the scanning line in the auxiliary direction of scanning coincides with the data for the formation start position data. It is axiomatic that a memory for storage of all the CDD groups which is controlled for sequential read out of these CDD groups is needed, which memory is called a first CDD memory unit (hereinafter referred to as a fresh CDD memory unit for simplicity of explanation).
Usually, one configuration continuously crosses one and ensuing several scanning lines. This means that the FDD read out from the fresh CDD memory unit is continuously processed at several successive scanning lines. Therefore, it becomes necessary to gradually change CDD as will be referred later and re-store them several times along with several data in order to shorten the processing time.
For this reason, it is preferred from the practical point of view to provide a second CDD memory unit which stores CDD being processed continuously (hereinafter referred to as a continuous CDD memory unit). The present invention employs such a memory unit. It is noted here that it is sufficient for the continuous CDD memory unit to have a capacity far smaller than that of the fresh CDD memory unit.
FIGS. 3A to 3H show the manner in which CDD groups are stored and controlled at the continuous CDD memory unit in corporation with the fresh CDD memory unit.
FIG. 3A shows in a simple form an example of CDD groups stored in the fresh CDD memory unit and associated with the n-th (wherein n is an integer) scanning line, and indicates that there are five CDDs, 1F 1 , 2F 1 , 3F 1 , 4F 1 and 5F 1 starting from this scanning line, and that there are four CDDs starting from the (n+1)-th scanning line, and also that there is zero CDD for the (n+2)-th scanning line and six for the (n+3)-th scanning line. Description is now made of the data shown in FIG. 2E in comparison with CDD group shown in FIG. 3A; the data n for the formation start position, the first CDD group 1F 1 , the second CDD group 2F 1 , the third CDD group 3F 1 , the fourth CDD group 4F 1 , and the fifth CDD group 5F 1 associated with n-th scanning line respectively correspond to 1,000, OR to ΔY a (addresses M+1 to M+4), R to ΔY b (addresses M+ 5 to M+8), R to ΔY d (addresses M+9 to M+12), OR to ΔY d (addresses M+13 to M+16) and pseudo CDD "E", "-", "-", "-", (addresses M+17 to M+20). Pseudo CDD is not shown in FIG. 3A.
FIG. 3B shows the state of the continuous CDD memory unit before the picture element series data formation is started, wherein R and W are symbols to indicate the read-out position and the write-in position for this memory unit. At this point, CDD to be stored in the continuous CDD memory unit naturally does not exist.
When the formation of the picture element series data is started, CDD read-out begins. As it is preferable from the point of control to read out CDD stored in the continuous CDD memory unit prior to reading out CDD stored in the fresh CDD memory unit, the present invention follows this order for reading out.
With the start of the formation process for the picture element series data for n-th scanning line, read out of CDD stored at the continuous CDD memory unit is started. With the just mentioned case, there exists no such CDD, and CDD read out from the fresh CDD memory unit is started immediately. As shown in FIG. 4, five CDDs of the new F 1 group associated with the n-th scanning line is successively read out from the fresh CDD memory unit and used for formation of the cross point data. If these CDDs are judged to be processed in the next scanning line in a manner as will be described later, they are somewhat modified or added with new data as desired, and stored in the continuous CDD memory unit as the 1st continuous F 1 group. The contents on the third line in the continuous CDD memory unit shown in FIG. 3C schematically show such modifications and addition of data, and as an example shows the frequency of the processing which has been completed. FIG. 3C shows the above mentioned five CDDs all judged to be processed in the (n+1 )-th scanning line and stored in the continuous CDD memory unit. In FIG. 3C, (E) denotes an end mark indicating the read-out termination position for the continuous CDD memory unit. It should be noted that CDDs stored in the continuous CDD memory unit are all to be processed continuously in the next scanning line so that the formation start position data is not essentially needed for them. Thus, there exists no formation start position data among the CDD groups stored in the continuous CDD memory unit.
In connection with the formation process for the picture element series data in respect of (n+1)-th scanning line, the CDD within the continuous CDD memory unit shown in FIG. 3C is sequentially read out and processed to give the 1st continuous F 1 group (see FIG. 4). FIG. 3D shows a transient state wherein three CDDs have already been processed and 1F 1 2, 2F 1 2 and 3F 1 2 are added as new data following not-processed data associated with the subject scanning line and further these are judged to be processed in the (n+2)-th scanning line to give the second continuous F 1 group and stored in the continuous CDD memory unit again. When processing of five CDDs concerning the second continuous F 1 group within the continuous CDD memory unit has been completed, four CDDs in the fresh CDD memory unit which start with the (n+1)-th scanning line and give new F 2 group are sequentially read out and processed. FIG. 3E shows a transient state in such a sequence. It should be noted that the end mark (E) disappears in the process where CDD inside the new CDD memory unit is being processed. FIG. 3F shows the state of the continuous CDD memory unit when the picture element series data formation in respect of (n+1)-th scanning line is completed.
FIG. 3G shows a state of the continuous CDD memory unit at the point when the picture element series data formation in respect of (n+2)-th scanning line has been completed, and it is considered advisable to discuss two points in particular at this time. The first point concerns that the present invention uses a cyclic control applied to the continuous CDD memory unit as is clear from FIG. 3G. It will be easily understood that this improves the utilization efficiency for the continuous CDD memory unit. The second point concerns that the CDD group having a formation start position data of "n+2" does not exist in the fresh CDD memory unit, and therefore only the second continuous F 1 group and the first continuous F 2 group are given in the formation process of the picture element series data for the (n+2)-th scanning line, and that there occurs no CDD read out from the fresh CDD memory unit and processing for CDD.
FIG. 3H shows the state of the continuous CDD memory unit at the time the picture element series data formation has been completed which was carried out to give the third continuous F 1 group, the second continuous F 2 group and the new F 4 group in respect of the (n+3)-th scanning line. Attention be made to disappearance of CDD in this phase. In other word, although several of CDDs within the continuous FDD memory unit have been processed in the formation process of the picture element series data for (n+3)-th scanning line, they are judged not to be processed continuously at the next (n+4)-th scanning line and have disappeared. As is clear from FIG. 3H, they are 2F 1 and 3F 1 starting with n-th scanning line, and 1F 2 and 4F 2 starting with (n+1)-th scanning line. As for the (n+4)-th scanning line, the fourth part continuous F 1 group, the third part continuous F 2 group, and the 1st continuous F 4 group are given.
FIG. 5 is a block diagram showing one example of structure for the picture element series data formation system according to the present invention. The CDD read out from a fresh CDD memory unit 501 or a continuous CDD memory unit 502 is sent to a cross point data formation unit 503. The cross point data formation unit 503 forms a cross point data referring to a registered configuration data stored at a memory unit 504 as desired, and sends them to a picture element series data formation unit 505. This unit 505 stores the picture element series data at a position of a picture element series data memory unit 506, which position is designated by the cross point data. A supply unit 507 supplies the picture element series data to the next processing unit 510 after the picture element series data in respect of one scanning line has been formed at the picture element series data memory unit. A continuation judgement unit 508 receives a part of CDD, judges whether or not the CDD is to be continuously processed in the next scanning line; if judged yes, it causes CDD retained in the cross point data formation unit 503 to be stored in the continuous CDD memory unit 502 via a signal line 503a. A memory control unit 509 controls the fresh FDD memory unit 501 and the continuous CDD memory unit 502 such that they operate in the manner above explained.
FIG. 6 is a block diagram showing an example of the process for forming the cross point data from the rectangular configuration CDD by the operation mode, and is shown to explain the detailed construction of the fresh or new CDD memory unit, the continuous CDD memory unit, the cross point data forming unit, the continuation judgement unit and the memory control unit, and their interrelations and operations. When the rectangular configuration CDD, or mode data O R , X and X are read out from either of a new CDD memory unit 601 or a continuous CDD memory unit 602, for instance from the latter, then these data are held at an CDD register 603 in the cross point data formation unit. Reference will be made later to Y. The O R is sent to a discrimination circuit 604 via a signal line 603a and when it is decided that processing for the rectangular configuration CDD by the computation mode is needed, signals are generated at signal lines 604a and 604b to enable gate circuits 605 and 606, respectively. Supposing that the value of X is 200, this value passes through the gate circuit 605, enters a cross point data register 607, thereby setting X s at 200. The value is also fed to one of inputs of an adder circuit 608. The other input of the adder circuit 608 receives ΔX. Supposing that the value of ΔX is 1000, the output of the adder circuit 608 is 1000+200=1200, which in turn is led to the cross point data register 607 through the gate circuit 606 to thereby set X E at 1200, thus forming one cross point data along with the aforementioned X s . When one cross point data is formed, a signal is sent to a read-out and storage control circuit in the memory control unit (hereinafter referred to as R-W control circuit) 609 via a signal line 607a, and read-out for the next CDD is started. On the other hand, ΔY from the new CDD memory unit 601 is sent to a continuation judgement unit 610. Assuming that ΔY is 5, the continuation judgement unit substracts 1 from the value of ΔY to obtain 4, and compares it with 0 (zero). As 4 is greater than 0, it is judged that the CDD held at the CDD register 603 is to be processed continuously in the next scanning line. Then, a signal is sent to the continuous CDD memory unit 602 via a signal line 610a to cause CDD held at the CDD register 603 and the continuation judgement unit 610 to be stored in the unit 602. Obviously, the CDD to be stored includes OR, 200, 1000 and 4. A raster counter 611 and a comparator circuit 612 are both included in the memory control unit. At the raster counter 611 is held a value to indicate that the picture element series data is being formed in respect of which scanning line. The comparator circuit 612 compares the formation start position data sent via a signal line 610a with the output of the raster counter 611, and transmits a signal to the R-W control circuit 609 if the two are equal to cause the read out of CDD from the new CDD memory unit 601 to start.
FIG. 7 is a block diagram to explain the formation process for the cross point data by the retrieval mode. A mode data R read out at a CDD register 701 (although shown as corresponding to the register 603 in FIG. 6, a separate register may be provided) is sent to a discriminating circuit 702 where it is judged to be for processing by the retrieval mode. Then, signals are generated at the signal lines 702a, 702b to enable gate circuits 703 and 704. Assuming that X is 1000, it is introduced to one of inputs of a subtractor circuit 705 and an adder circuit 706. Symbol T denotes a read-out address at a registered configuration data memory unit 707. Assuming that T is 100 and dnL=500 and dnR=300 are stored at the address 100 of the registered configuration data memory member 607, these values are read and fed to the other input of the subtractor circuit 705 and the adder circuit 706, respectively. The output of the subtractor circuit 705 is 1000-500=500, and that of the adder circuit 706 is 1000+300=1300, which values are then introduced to a cross point data register 708 via the gate circuits 703 and 704 to form a cross point data. It will be understood that although the same steps for judging the continuation as in the case of the operation mode are carried out, when storing CDD processed by the retrieval mode in the continuous CDD memory unit, 1 is added to T, so that in this instance 100+1=101 takes place.
As for the picture element series data formation unit wherein the picture element series data is stored based on the cross point data formed at the cross point data formation unit, it is easily realized using the technology disclosed, for instance in Japanese Patent Application No. 52-135512 entitled "Dot Pattern Generating Circuit". Therefore, no detailed discussion will be given here.
By providing a buffer memory means in the foregoing embodiment of the picture element series data formation system according to the present invention, a speed processing can advantageously be realized. For instance, memory regions for two scanning lines may be provided in the picture element series data memory unit and used to simultaneously conduct the formation of the picture element series data and the supply thereof to the subsequent processing unit.
In the embodiment explained heretofore, the concept for this invention is embodied based on the instance where comparatively simple master is drawn as shown by the reference numerals 101, 102 and 103. A second embodiment offers a construction for forming picture element series data concerning a more complicated figure.
FIG. 8 shows one example of such a complex figure. Figure 801 is one actually used as a master of air inner lay conductive type 1 and for a printed wiring board. Although it is a figure actually used, it will be easily seen that it is not a normalized figure. Now consider a method of disassembling the figure 801 for normalization when forming the picture element series data for the raster with the figure 801. It will be reasonable to break down the figure into four figures of 901, 902, 903 and 904 as shown in FIG. 9. Supposing that the scanning lines move in the directions indicated by arrows 905 and 906, then the figures 901 and 902 are not normalized. In other words, the configuration of the figures 901 and 902 are such that they cross the scanning lines at four points. Then, the figures 901 and 902 may be divided into two sections, for instance along dotted lines 907 and 908, to complete the normalization of the figures.
However, thus normalized figures are quite different from the commonly occurring figures of circle or rectangle, and their handling is quite complicated.
FIG. 10 shows the method of disassembling and the order of compiling for normalized figure when forming the picture element series data for drawing the figure 801 in FIG. 8. The figures 1001, 1002, 1003-1, 1003-2 and 1004 are all normalized. In figures 1002, 1003-1, 1003-2 and 1004, d 1 , d 2 and D 1 have the same dimensions as their corresponding parts of FIG. 8. Assuming that either the figure 1002 or the figure 1004 is placed over the hatched portion of the figure 1001, and the hatched area of the figure 1001 is to be erased by the area corresponding to the area enclosed by the contour in the figure 1002, or 1004, these figures may be "overlapped" in this order to obtain the figure 801 shown in FIG. 8. In this case the order of overlapping the figure 1002 with those of 1003-1 and 1003-2 are reversible, and each of these figures may also be treated as one normalized figure.
Although the detailed reference will be made later, it is pointed out that overlapping of the figures as discussed here means overlapping of the figures in terms of electric signals, and as is clear from the foregoing description, the important thing in the formation of the picture element series data in the present embodiment is the order in which they are overlapped as well as the configuration and the tone of the normalized figures.
In this embodiment, EDD corresponds to CDD of the first embodiment. The reason why the two are distinguished is that the former contains the tone data. Since the amount of tone data is rather limited in practice, however, it is possible to store it in the same place as in the mode data in the case of CDD. Therefore, FDD may be considered entirely identical in form with CDD even if the tone data is included. Storage of FDD in the memory unit is also substantially the same as that for CDD, and therefore is not detailed.
FIG. 11 shows a construction of the picture element series data formation system according to the present second embodiment. The FDD read out from either one of a first FDD memory unit 1101 or a second FDD memory unit 1102 is transmitted to a cross point data formation unit 1104 via a memory control unit 1103. As described with reference to the first embodiment, there is formed a cross point data from FDD by the operation mode or the retrieval mode at the cross point data formation unit 1104. As the complex figures as mentioned in the embodiment are often processed by the retrieval mode, explanation is given of the formation process of the cross point data by the retrieval mode by taking the example of the figure 1001 shown in FIG. 10. As explained before with reference to FIGS. 2B and 2C, arrows 1005 and 1006 indicate the primary and auxiliary directions X and Y of scanning. In this case, FDD for the figure 1001 includes R, X a , (Y a ), ΔY, and T with R indicating the mode data wherein the FDD is to be processed by the retrieval mode. As the picture element series data formation proceeds into the formation process of the picture element series data for Y a -th scanning line, FDD is read out from the first FDD memory unit 1101 to the cross point data forming unit 1104. At the cross point data forming unit 1104, a registered configuration data RFD is read out from a (T+n) address of the RFD memory unit 1105 according to the mode data R. (See FIG. 2C). When these are termed dnL and dnR, the cross point data are formed to establish X s =X a -dnL and X E =X a +dnR. Thus obtained cross point data are then transmitted to a memory selecting unit 1106, which emits signals to select the memory elements corresponding to the picture elements positioned between the two cross points of the cross point data from a picture element series data memory unit 1108. Such a memory selecting unit 1006 may be realized using the technology disclosed, for example, in Japanese Patent Application 52-135512 entitled "Dot Pattern Generating Circuit" as set forth hereinbefore. A tone control unit 1107 controls the memory elements of the picture element series data memory unit selected by the memory selecting unit 1106 to store the tone data supplied via a signal line 1103 a . "Overlapping" of figures in terms of electric signals mentioned before is the total function incorporating various functions of the memory selecting unit 1106, the tone controlling unit 1107, and the picture element series data memory unit 1108. After the picture element series data in respect of one scanning line has been formed at the picture element series data memory unit 1108, a supply unit 1109 supplies the same to the following processing unit 1110. A continuation judging unit 1111 judges whether or not the following scanning line crosses the configuration, and having judged yes, processes the FDD for continuation, and causes the same to be stored in the second FDD memory unit 1102.
As for example of the aforementioned FDD, 1 is subtracted from ΔY, and when the result is greater than 0, a new FDD including R, X a ΔY-1, and T+1 is stored in the second memory unit 1102. As shown in the first embodiment, Y a is used as a sorting key and therefore does not appear in FDD.
FIGS. 12A to 12E are diagrams to explain the "overlapping" of figures in terms of electric signals taking an example of the picture element series data related to the scanning line 802 of the figure 801 shown in FIG. 8. The arrows 1107, 1008, 1009 and 1010 shown in FIG. 10 indicate the scanning line identified by the arrow 802 in FIG. 8, being placed over the normalized patterns 1001, 1002, 1003-1 and 1004, respectively. FIGS. 12A, 12B, 12C, 12D and 12E diagramatically show portions of the picture element series data memory unit, wherein "1" represents black and "0" represents white. FIGS. 12A is a state before the picture element series data formation begins and therefore all are "0" or white. FIGS. 12B to 12E respectively show the state where the picture element series data respectively are formed at the position of the scanning line 802 of the normalized figures 1001, 1002, 1003-1 and 1003-2, and 1004. The last of the figures, FIG. 12E, shows the picture element series data at the position of the scanning line 802 of the figure 801.
As will be clear from the foregoing description, the overlapping of the figures in terms of the electric signals used herein is the operation wherein while using the signals from the memory selecting unit as a mask signal, the tone data is stored in the picture element series data memory unit in the predetermined order. This operation is easily conducted using an ordinary multiplexer circuit, etc. and therefore no detailed description is given. Use of the picture element series data formation system according to the present embodiment will facilitate treatment of a complex figure and efficient formation of the picture element series data.
Heretofore, the concept of the picture element series data formation system according to the present invention and the treatment of comparatively complex figures which included arcuate portions have been discussed with reference to the first and the second embodiments. With the third embodiment to be described below, it is possible to efficiently form the picture element series data for drawing the figures usually occurring in master figures for the printed broad wiring. The discussion is now made to the "figures usually occurring in master figures for the printed wiring board". The master figure for the printed board wiring prepared using the so-called photo-probe plotter comprises a figure formed as the aperture attached to the photohead of such a device moves between the two points "linearly", and means "The figure usually occurring in the master figure for the printed wiring board" as mentioned in the present embodiment.
The expression that apertures "move linearly between the two points" includes an instance where the two points are identical and in this instance various shapes of apertures are used. On the other hand the aperture moving between the two different points is usually circular in shape. Therefore, the description given below will discuss an example of a figure formed as the circular shaped aperture moves linearly between the two different points.
FIGS. 13A and 13B are the drawings to explain the configurations of general figures formed as the circular aperture move between two different points linearly. Arrows 1301 and 1302 in the figures show, as in the embodiments described before, the primary direction X and auxiliary direction Y of scanning. When the two different points are denoted as P and Q, in view of the relative positions of P and Q, it is preferable to consider the configuration of the general figure formed by the linear movement of the circular aperture between the two points in terms of the two instances as shown in FIGS. 13A and 13B. Supposing that coordinates at P and Q are respectively (P x , P y ) and (Q x , Q y ), ΔX=|P x -Q x |, ΔY=|P y -Q y |, and the radius of the circular configuration is R, it will be easily confirmed that FIG. 13A corresponds to a case where the relation of ΔY/ΔX≧2R/√(ΔX) 2 ×(ΔY) 2 establishes between ΔX, ΔY, and R, whereas FIG. 13B corresponds to a case where ΔY/ΔX<2R/√(ΔX) 2 +(ΔY) 2 stands.
It is clear that the configuration 1303 of FIG. 13A is normalized with two circular configurations, one parallelogram BFDE, and two right angle triangles AEG and CFH (right angle triangles ABG and CDH are included in the circular configurations). Similarly, the configuration 1304 in FIG. 13B is normalized with two circular configurations, one rectangle EGFH, and two right angle triangles ADE and CBF. When the line connecting the point P and the point Q is parallel to the primary or auxiliary direction of scanning (practically most figures are included in this category), it will be easily understood that the configuration of a figure to be drawn is normalized with two circular configurations and one rectangular configuration having the sides parallel to the primary or auxiliary direction of scanning as described in detail with reference to the first embodiment.
Since the rectangular configuration may be considered one special form of parallelogram and therefore the former may be included in the latter, then the normalized configuration obtained from the figures formed as the circular aperture moves between the two points linearly includes either one of the circular configurations which is the figure of the aperture, the parallelogram having a set of opposite sides parallel to the primary direction of scanning, and the right angle triangle having two sides subtending right angles which are parallel to either the primary or auxiliary direction of scanning. In the case where the two points are identical point, the aperture is not necessarily circular and various normalized figures appear although the number of their types is limited. These are called registered figures inclusively and represented by a circular configuration in the discussion to follow. The configuration of a figure formed when the aperture having configurations other than a circle moves between the two different points linearly may finally be normalized into the three types of normalized figures, although details will not be given.
The process of forming the cross point data from the normalized configuration is also important in forming the picture element series data from the present embodiment as was in the previously discussed embodiments. The emphasis therefore will be placed on the process of forming the cross point data from the above mentioned three normalized configurations in the description to follow.
Of the three types of normalized configurations, the registered configuration is processed by the retrieval mode, and the parallelogram and the right angle triangles by the computing mode. The circular configuration is a registered configuration and processed in the same way as in the previously described embodiments. Therefore, the explanation thereof is omitted. The parallelogram CDD in FIG. 14A comprises six data of O p , X b , Y b ΔX b , ΔY b and L. The O p is naturally the mode data for this parallelogram. The right angle triangle CDD in FIG. 14B comprises five data of O t , X c , Y c ΔX c and ΔY c . As shown in the drawing, two right angle triangles shown by the solid lines and the broken lines are conceivable either one of which may be selected practically in accordance with a parameter added in the O t .
FIG. 15 takes as an example the configuration shown in FIG. 13A, and illustrates assembling of the normalized configurations and corresponding CDDs. The configuration 1303 in FIG. 13A is normalized with five normalized configurations of 1501, 1502, 1503, 1504 and 1505 shown at (1), (2), (3), (4) and (5) in FIG. 15, and it will be confirmed easily that by assembling these five normalized configurations, the original configuration 1303 is obtainable. The CDD of the above-mentioned normalized configurations are respectively shown at (1)', (2)', (3)', (4)', and (5)' in FIG. 15. Symbols L, U in the mode data for the right angle triangular configurations Ot(L), Ot(U) represent "Lower" and "Upper" respectively indicating whether the apex of the right angle is on the upper side or the lower side of the base. In this example, the relation between the Y coordinates P'y Ay, By, Q'y and Fy of the points P', A, B, Q' and F is P'y<Ay<By<Q'y<Fy. It should be noted, however, that P'y, Ay, By, Q'y and Fy are not included in the individual CDD since the CDD is sorted by using Y as a sorting key prior to information of the cross point data and therefore are aligned in the order of generation in the auxiliary direction of scanning and the increment in the auxiliary direction from Y of the sorting key alone may be included. Therefore, they are in bracket in the drawing.
FIG. 16 is a block diagram to explain the arrangement of the system according to this embodiment. As in the case of the first and second embodiments, the CDD is read out from a first CDD memory unit, that is, a fresh CDD memory unit 1601, or a second CDD memory unit, that is, a continuous CDD memory unit 1602 under the control of a memory control unit 1603 and sent to a cross point data formation unit 1604. At the cross point data formation unit 1604, a cross point data is formed according to the CDD mode data by referring to RFD in an RFD memory unit 1605 in the case of the retrieval mode or by the internal operation in the case of the operation mode.
When one cross point data is formed, a signal appearing at a signal line 1604a controls the memory control unit 1603 and causes the next CDD to be read out. The memory selection unit 1606 receives the cross point data, selects memory elements corresponding to picture elements between the two cross point data from the picture element series data memory unit 1607, and causes a signal indicating that the figure exists in the memory elements to be stored. Such a memory selection unit 1606 may be realized by using the technology disclosed in, for instance, Japanese Patent Application No. 52-135512 entitled "Dot Pattern Generating Circuit".
When the picture element series data for one scanning line is formed at the picture element series data memory unit 1607, a signal appears at a signal line 1606a to cause the memory control unit 1603 to read out the CDD for the next scanning line. A supply unit 1608 supplies the picture element series data for one scanning line to the ensuing processing unit 1609 after it has been formed. A continuation judgement unit 1610 receives a value of ΔY in the CDD from the cross point data formation unit 1604 via a signal line 1604b, deducts 1 from the ΔY value, and compares the obtained value with 0 in order to judge whether or not the configuration represented by the CDD crosses the next, following scanning line. If it is judged to cross, or the value ΔY-1 is greater than 0, a signal is sent to the memory control unit 1603 via a signal line 1609a to have the same stored in the CDD memory unit 1602 via a signal line 1604c.
FIG. 17 is a block diagram to explain in further detail the operation of the cross point data formation unit 1604 by taking an example of CDD for plotting the figure shown in FIG. 13A. A discriminating circuit 1701 discriminates the type of CDD supplied from the fresh and continuous CDD mode data via signal lines 1711 and 1712, and sends the CDD to control circuits 1702 to 1704 in accordance with the results obtained. The control circuit 1702 is adapted to control the formation process of the cross point data in registered form, and reads RFD, for instance, dnL and DnR, from an RFD memory unit 1705 and sends the read-out RFD along with X a of CDD to an operation circuit 1706 where the cross point data is sought by computing X a -dnL, and X a +dnR. The control circuits 1703 and 1704 respectively control the process for forming the cross point data for parallelogram and the right-angle triangular configurations, and a part of the CDD transmitted thereto is supplied to a vector generator circuit 1707 to seek the cross point of the hatched portions of the respective configurations and the raster. The vector generator circuit 1707 may be realized by using the technology known such as from Japanese Patent Application Laid Open No. 52-108739 entitled "Vector Generator". The output of the vector generating circuit 1707 is sent to either one of synthesizer circuits 1708 and 1709. Assuming that the output of the vector generator circuit 1707 is X o , the value of X o and L are sent from the synthesizer circuit 1708 to the operation circuit 1706, thereby obtaining the cross point data of X o and X o +L. Either one of X c and X c +ΔX c is sent from the synthesizer circuit 1709 by X o and the mode data O t to the operation circuit 1706, producing the cross point data being X c and X o in the case of X c , and X o and X c +ΔX c in the case of X c =ΔX c .
In the present embodiment, the rectangular configuration is deemed to be classified into the parallelogram, although it may naturally be treated separately.
It should be understood that the continuation judgement unit according to the present invention may be comprised of an ordinary subtractor and a comparator since, in the unit, 1 is subtracted from the ΔY value in CDD and a result is compared with 0.
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A display pattern preparing system for forming picture element series data for formation and display of picture images by raster scanning. "Figure" or "Configuration" of a pattern is disassembled to be normalized. An fixed pattern memory stores, as a registered configuration data, the length of a segment by which a fixed pattern of a prescribed configuration and area crosses a scanning line in the primary direction of scanning. An analogous pattern memory stores, as parameters, a reference position data representative of a reference point for a portion of an analogous pattern through which the analogous pattern overlaps the scanning line, the analogous pattern being defined as a pattern whose configuration is analogously variable, a distance data representative of the length of the portion of the analogous pattern, and a change ratio data representative of a ratio at which the reference point changes in the auxiliary direction of scanning. The data of the fixed pattern and analogous pattern memories are read out for preparation of a position data for display of a pattern designated by the read-out data. The position data is transmitted to display units.
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BACKGROUND OF THE INVENTION
The present invention relates generally to a fire hydrant nozzle assembly and, more particularly, to a configuration for readily and simply attaching a bronze fire hydrant nozzle to a cast iron hydrant barrel without the use of leading caulking, screw threads, or other methods generally requiring machining. The invention also relates to avoiding un-intentional removal of the bronze nozzle as a result of the application of relatively high torque typically required to remove a protective cap.
Conventional fire hydrants comprise a vertical upstanding cast iron barrel with a plurality of discharge nozzles or outlets, attached usually at 90° to the axis of the barrel. The discharge nozzles comprise separate bronze sleeve-like elements secured within annular bosses cast as a part of the hydrant barrel. Nozzles are screw threaded at an outlet end to alternately receive either a protective cap or a standard hose connection.
Typical such bronze nozzles are attached to the hydrant barrel casting by filling a large annular space between the bronze nozzle and the boss portion of the iron barrel casting with molten lead. After the lead has cooled and solidified, it is then caulked (pounded with a special chisel-like tool) to compact it and effect a seal. In order to help prevent nozzle rotation or blow out, some designs additionally incorporate a stop, cast in the bronze, which mates with a slot in the hydrant boss, or vice versa.
Replacement of a damaged nozzle involves a fairly complicated procedure. Initial removal requires remelting the lead, and re-installation of the nozzle or a replacement nozzle requires pouring molten lead into a vertical annular space since the hydrant barrel will typically be standing vertically in the field. Replacement also requires caulking, a procedure requiring considerable skill and craftsmanship.
Another type of prior art design employs machined screw threads on the bronze nozzle for attachment to the hydrant boss, and a small gasket such as a rubber O-ring to provide a seal. This design approach also requires that mating threads be provided on the inside of the hydrant boss, such as by machining. The disclosure of the Dunton U.S. Pat. No. 3,534,941 provides a typical example of such a fire hydrant including machined screw threads on the bronze nozzle.
To prevent turn out of a machined screw thread type nozzle when the protective cap is removed, two general approaches have previously been employed. One approach, such as disclosed in the Dunton U.S. Pat. No. 3,534,941, is to provide a small pin or screw fitted in aligned apertures extending radially through portions of the nozzle and hydrant barrel. Another approach is to use left-hand threads for the connection of the nozzle to the hydrant barrel. These left-hand threads are tightened as torque is applied to remove the nozzle cap, which has standard right-hand threads. With either of these two approaches, adhesives are sometimes applied to the threads to provide additional resistance to turn out.
Removal of a machined and threaded-nozzle typically requires removal of the pin by drilling, unscrewing or driving inwardly, and then the application of a large amount of torque to break the adhesive or the corrosion products built up in the iron-to-bronze threaded connection.
One drawback to the threaded in nozzle designs is that alignment of the apertures for the pin is dependent upon the location of the start of the first threads on the circumferences of the nozzle and boss, as well as the precise degree of tightening required. Tapping and thread cutting operations are normally independent of angular orientation with respect to circumference, and dependent only upon position with respect to the axis of a cylinder. Therefore, alignment of predrilled holes in the hydrant nozzle using threads to attach it to the boss is almost impossible. Consequently, the holes for the pin in such designs must be drilled after screwing the nozzle into the hydrant boss, making field replacement a difficult task since the new nozzle must be drilled to accept the pin in the field.
Another disadvantage of some designs of the type employing machined threads in the hydrant boss and nozzle is that a wrench-engaging lug is required to be cast on the inside of the bronze nozzle, the lug extending into the waterway. This lug is used to allow a wrench, placed in the nozzle, to engage the nozzle for tightening into the hydrant boss. However, such lugs inhibit the flow of water and increase pressure loss through the hydrant.
The present invention provides a nozzle assembly wherein the nozzle is attached to the barrel of a fire hydrant without the use of lead caulking, screw threads, or other methods generally requiring machining. Additionally, the problem of the bronze nozzle unintentionly being removed as a result of the high torque necessary to remove a nozzle cap is effectively dealt with.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a fire hydrant nozzle assembly which is easy to install, effectively prevents unintentional nozzle removal, assures a reliable seal, and in which removal and replacement of the bronze nozzle when required is a relatively simple procedure.
It is another object of the invention to provide such a nozzle assembly which eliminates any need for machining operations on the inside of the cast iron hydrant boss.
It is still another object of the invention to provide a fire hydrant nozzle assembly which does not involve the use of lead caulking.
Briefly, in accordance with an overall concept of the invention, a bronze nozzle member is retained within a hydrant boss member by means of a bayonet type or breech lock type mechanism involving cooperating lugs, and a resilient seal such as an O-ring is provided. For locking the nozzle member in its installed position, a pin element passes through a pair of corresponding apertures in confronting surfaces of the boss and nozzle members. The installed position is positively defined by respective locating engagement surfaces carried by the boss and nozzle members, which surfaces serve to limit rotation. The corresponding apertures can always be aligned even though they are pre-formed or pre-drilled. Preferably, the locating engagement surfaces are configured and positioned such that locking rotation of the nozzle following insertion into the boss occurs in a direction opposite to the direction of the threads on the outlet end of the nozzle such that when the nozzle cap is removed the locating engagement surfaces resist the torque involved.
Briefly stated, and in accordance with one particular aspect of the invention, a nozzle assembly for a fire hydrant having a barrel includes a nozzle boss member extending outwardly from the hydrant barrel and having a generally cylindrical inner surface defining an opening. The boss member has at least one boss lug projecting radially inwardly from the cylindrical inner surface. Preferably, the boss lug extends generally circumferentially along the cylindrical inner surface. The boss lug has an axial engagement surface facing generally along the axis of the nozzle boss towards the hydrant barrel.
A nozzle member is adapted to be retained in the boss member, the nozzle member having a waterway extending therewithin along the axis thereof. The nozzle member has a generally cylindrical outer surface. At an insertion end of the nozzle member the outer surface is configured for engagement within the nozzle boss member opening, and at an outlet end the nozzle member is configured to alternately receive a cap or a hose connection by means of standard screw threads.
Projecting radially outward from the cylindrical outer surface of the nozzle member it is at least one nozzle lug, preferably extending generally circumferentially along the outer surface. The nozzle lug has an axial engagement surface facing generally along the nozzle axis towards the outlet end of the nozzle for engagement with the boss lug axial engagement surface.
The nozzle lug and the boss lug are sized and configured such that the nozzle and boss members may be rotationally relatively aligned with each other initially to permit axial passage of the lugs past one another as the nozzle is inserted into the boss to reach an inserted position, and thereafter to permit rotation, preferably counterclockwise, of the nozzle member within the boss member to reach an engaged position whereat the axial engagement surfaces engage to retain the nozzle member in the boss member.
In order to positively locate the engaged position by preventing further rotation of the nozzle member within the boss member past the engaged position, respective locating engagement surfaces are carried by the boss member and the nozzle member. The locating engagement surfaces are configured and positioned so as to engage one another when the engaged position is reached.
In order to lock the nozzle member in the engaged or assembled position, a pair of corresponding apertures are formed in confronting surfaces of the boss and nozzle members and positioned so as to be in alignment when the boss and nozzle members are in the engaged position. A pin element is suitably configured for insertion through the pair of corresponding apertures to lock the nozzle member in the engaged position within the boss member. The positioning of the corresponding apertures for the locking pin element is positively defined by the positioning of the locating engagement surfaces. Thus the apertures can always be aligned during assembly even though the apertures are pre-formed.
Preferably, the aperture in the boss member is a blind aperture sufficiently deep to allow the pin to be driven completely through the aperture in the nozzle member to unlock the nozzle for removal from the boss member. This blind aperture may comprise a notch- or slot-like recess communicating radially with the opening in the boss member which receives the nozzle. The recess configuration provides easy access to the pin when the nozzle is removed. Moreover, on a generally horizontally-extending boss member, the recess is preferably circumferentially located at the bottom to provide an effective drain for any water which enters the space between the boss member and the nozzle due to weather.
To prevent unintentional removal of the nozzle assembly, the locating engagement surfaces are preferably arranged such that rotation of the nozzle member within the boss member from the inserted position to the engaged position at which the locating engagement surfaces prevent further rotation is in the same direction as torque is exerted on the nozzle member when a cap is removed. With standard, right-hand screw threads for the nozzle cap, this rotational direction for which particular resistance to torque is required is counterclockwise.
To provide a fluid tight seal, a resilient sealing element is provided generally between the insertion end of the nozzle cylindrical outer surface and the nozzle boss member. This seal location ensures that water under pressure does not enter the locking mechanism, minimizing electrolytic corrosion between the dissimilar metals of the nozzle (bronze) and hydrant boss (iron). Further, as stated above, the notch or slot-like recess in the boss member for the locking pin serves as a drain for any water which enters the space between the boss member and nozzle due to weather.
Preferably, this resilient sealing element comprises an O-ring compressed between an annular region near the insertion end of the cylindrical outer surface of the nozzle member and a mating annular region on the inner cylindrical surface of the boss member. This mating annular region preferably has an annular recess for retaining the O-ring, and the insertion end of the nozzle has a chamfer or beveled edge to compress the O-ring as the nozzle member is initially inserted into the boss to the inserted position.
In the preferred embodiments, the cylindrical inner surface of the nozzle boss member and the cylindrical outer surface of the nozzle member have respective annular portions defining respective annular clearance regions respectively receiving the nozzle lugs and the boss lugs. The clearance regions permit rotation of the nozzle member within the nozzle boss member at least between the inserted and engaged positions. A stop is carried by at least one of the boss and the nozzle members and extends into the corresponding one of the clearance regions. One of the locating engagement surfaces is provided on the stop, and the other of the locating engagement surfaces is provided on the lug of the other of the members. In the illustrated embodiments, the stop is carried by the nozzle member and projects generally radially outward from the nozzle member annular surface portion. The other of the mating locating engagement surfaces is then provided on the boss lug, and comprises a surface facing generally inwardly towards the axis of the nozzle boss cylindrical surface.
Preferably, there are provided a plurality of equally spaced substantially identical boss lugs, and each of the mating locating engagement surfaces provided on the boss lugs is perpendicular to a radius extending from the axis of the boss member. Thus the mating locating engagement surfaces provided on the boss lugs geometrically define respective chords intersecting the boss member inner cylindrical surface. The chords together subtend approximately one-half of the 360° angular distance around the inner cylindrical surface for maximum contact area. An identical plurality of equally spaced substantially identical nozzle lugs is provided. The nozzles lugs are separated by flat surfaces tangential to the nozzle member outer cylindrical surface at the mid-point of each pair of nozzle lugs. The flat surfaces between the nozzle lugs are configured to align with the boss lug mating locating engagement surfaces during initial insertion of the nozzle member into the boss member.
The fire hydrant nozzle assembly preferably additionally comprises an identical plurality of equally spaced substantially identical stops, the ones of the locating engagement surfaces provided on the stops comprising flat surfaces tangential to the nozzle member outer cylindrical surface at the center line of each nozzle lug.
The stops additionally each have an insertion engagement surface comprising a planar extension of the flat surfaces separating the nozzle lugs and configured to engage planar extensions of the mating locating engagement surfaces provided on the boss lugs so as to prevent rotation from the inserted position in a direction opposite to that which is necessary to reach the engaged position.
The present invention therefore provides a fire hydrant nozzle assembly which is easy to initially install upon manufacture, and easy to remove and replace when required. A reliable seal is assured, and unintentional removal of the bronze nozzle by torque required to remove a cap is prevented. The assembly eliminates the need to machine the inside of the hydrant boss for any purpose, and the boss can simply be cast as a part of the barrel.
BRIEF DESCRIPTION OF THE DRAWINGS
While the novel features of the invention are set forth with particularity in the appended claims, the invention, both as to organization and content, will be better understood and appreciated from the folllowing detailed description taken in conjunction with the drawings, in which:
FIG. 1 is a side elevational view of a prior art fire hydrant, with the nozzle assembly portion thereof broken away and shown in section;
FIG. 2 is an elevational view of the nozzle assembly of the present invention, with the nozzle boss portion thereof shown in section and the nozzle portion shown in full;
FIG. 3 is an elevational cross sectional view similar to that of FIG. 2, but showing the nozzle boss member only;
FIG. 4 is a side elevation taken along line 4--4 of FIG. 3;
FIG. 5 is an overall perspective view of the bronze nozzle of the invention, the FIG. 5 orientation being rotated 180° from the installed position shown in FIG. 2 to better illustrate the configuration of the nozzle member;
FIG. 6 is a nozzle member side elevational view generaly comparable to FIG. 2, but with a different angular orientation to better illustrate the lugs and stops; and
FIG. 7 is a cross section taken along line 7--7 of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein identical reference numerals denote similar or corresponding elements throughout the various views, FIG. 1 illustrates a prior art fire hydrant generally designated 10 including a representative prior art nozzle assembly 12 of the leaded in type. The hydrant 10 comprises conventional cast iron upper and lower barrel sections 14 and 16, a cover 18, and a base 20. The lower barrel section 16 enters the ground as indicated by the dash ground line 22. Water under pressure enters the base 20 through a cast iron joint gland 24, and is controlled by a hydrant valve assembly (not shown) which may be of conventional construction and which is disposed generally within the lower barrel section 16 and the base 20. The valve is controlled through a rotatable actuator rod (not shown) terminating in an operating nut 26 on the cover 18.
Projecting at right angles from the upper barrel 14 are a plurality of discharge nozzle assemblies, such as the representative prior art nozzle assembly 12 and a similar, slightly smaller nozzle assembly 28.
The representative prior art nozzle assembly 12 includes a nozzle boss 30 comprising a short cast iron annular protrusion from the upper barrel 14, the upper barrel 14 and the nozzle boss 30 being cast as one piece.
The assembly 12 further includes a bronze nozzle member 32 inserted into the boss 30, and retained by means of lead caulking 34 in accordance with conventional practice as briefly summarized hereinabove.
The outlet end of the nozzle member 32 is threaded as at 36 to alternatively receive a protective cast iron cap 38 or a conventional fire hose coupling (not shown). A flat rubber gasket 40 of ring configuration provides a seal between the cap 38 and the nozzle member 32.
To avoid loss of the cap 38, a chain, partially shown at 42, extends between a steel chain holder 44 bolted to the hydrant upper barrel 14 and a conventional attachment (not shown) fitted to an annular recess 46 provided on the cap 38 adjacent a cap nut 48.
As noted hereinabove, the prior art fire hydrant 10, and particularly the nozzle assembly 12 thereof, has a number of disadvantages overcome by the nozzle assembly of the present invention, which will now be described with reference to FIGS. 2-7.
In FIG. 2, a nozzle assembly 50 embodying the invention is shown in its fully engaged and assembled position. The nozzle assembly 50 generally comprises a boss member 52 extending outwardly from a cast iron hydrant barrel 54 and cast as an integral part thereof. The boss member 52 is described in greater detail hereinbelow with particular reference to FIGS. 3 and 4. The nozzle assembly 50 additionally generally comprises a bronze nozzle member 56 retained in the boss member 52, the nozzle member 56 including helical threads 58 for conventional alternate attachment either to a cap (not shown) or a standard hose coupling. The nozzle member 56 is described in greater detal hereinbelow with particular reference to FIGS. 5, 6 and 7.
As may be seen from FIG. 2, the boss member 52 is generally shaped as a cylindrical outlet in the hydrant barrel 54, at an exemplary only 90° angle with respect to the axis of the barrel 54. The boss member 52 has a generally cylindrical inner surface 60 defining an opening.
The nozzle member 56 is also generally cylindrical, having an outer generally cylindrical surface 62, and a waterway 64 extending therewithin along the axis thereof. An insertion end 66 of the nozzle member 56 is received within the hydrant boss member 52.
A resilient sealing element 68 provides a fluid tight seal generally between the insertion end 66 of the nozzle cylindrical outer surface 62 and the nozzle boss member 52. This location of the sealing element 68 at the nozzle insertion end 66 ensures that water under pressure does not enter the space including the various engaging and retaining elements described hereinafter with reference to FIG. 3-7. More particularly, the resilient sealing element 68 comprises an O-ring compressed between an annular region 70 near the insertion end 66 of the nozzle cylindrical outer surface 62 and a mating annular region 72 on the inner cylindrical surface 60 of the boss member 52. The inner cylindrical surface 60 of the boss member 52 preferably has an annular recess comprising the mating annular region 72 for retaining the O-ring 68, and the insertion end 66 of the nozzle member 56 has a chamfer 73 which acts like a pipe joint spigot to compress the O-ring 68 during insertion. The annular recess 72 and the O-ring 68 are suitably designed so as to accommodate dimensional tolerances or variations which may normally be expected in a casting of the size involved.
Also shown in FIG. 2 is a flange 74 encircling the nozzle member 56, with a flange lug 76 projecting from the flange 74. To lock the boss end nozzle members 52 and 56 in the engaged position shown in FIG. 2, a pin element 78 is inserted through an aperture 80 provided in the flange 74 in alignment with a corresponding aperture 82 provided in a ring-like surface 84 of the boss member 52. The boss member surface 84 and a surface 85 of the flange 74 are thus confronting surfaces. For convenience, the flange lug 76 has an additional aperture 86 for retaining a chain shown partially at 88 which serves to prevent loss of the cap (not shown). The cap involved may be any standard prior art cap such as the cap 38 depicted in FIG. 1.
With reference to FIGS. 3 and 4, engaging and retaining elements comprising portions of the boss member 52 will now be described in greater detail. Projecting radially inwardly from the boss member cylindrical inner surface 60 are a plurality of boss lugs 88. While four boss lugs 88 are illustrated, other numbers may be employed. As few as one, or as many as eight may be employed if necessary. The boss lugs 88 may either be truly circumferential to comprise an element of a bayonet-type mechanism, or be helical and act as a breech lock-type mechanism.
The boss lugs 88 each have an axial engagement surface 90 facing generally along the axis of the nozzle boss 52 cylindrical inner surface 60 towards the hydrant barrel 54.
As may be seen from FIGS. 5, 6 and 7, the nozzle member 56 includes a corresponding plurality of nozzle lugs 92 projecting outwardly from the nozzle member 56 cylindrical outer surface 62. Each of the nozzle lugs 92 has an axial engagement surface 94 facing generally along the nozzle axis towards the outlet end of the nozzle 56 for engagement with the boss lug axial engagement surfaces 90.
The nozzle lugs 92 and the boss lugs 88 are sized and configured such that the nozzle 56 and boss members 52 may be rotationally relatively aligned with each other initially to permit axial passage of the lugs 92 and 88 past one another as the nozzle member 56 is inserted into the boss member 52 to reach an inserted position at which the insertion end 66 bears against an annular protrusion 96 on the boss member 52, and thereafter to permit rotation of the nozzle member 56 within the boss member 52 to reach the engaged position depicted in FIG. 2 whereat the axial engagement surfaces 94 and 90 engage to retain the nozzle member 56 within the boss member 52.
In order to receive and provide clearance during rotation for the lugs of the opposite member, the cylindrical inner surface 60 of the boss member 52 and the cylindrical outer surface 62 of the nozzle member 56 have respective annular surface portions 98 and 99 defining respective annular clearance regions 100 and 101. The clearance region 100 on the boss member 52 provides clearance for the nozzle lugs 92, and the annular clearance region 101 on the nozzle member 56 provides clearance for the boss lugs 88. The clearance regions 100 and 101 permit relative rotation of the nozzle member 56 within the boss member 52 at least between the inserted position and the engaged position depicted in FIG. 2.
For limiting rotation of the nozzle member 56 within the boss member 52, at least one of the annular surface portions 98 and 99 of the members 52 and 56 carries a stop 102 extending into the corresponding one of the clearance regions 100 and 101. In the preferred embodiment illustrated the stop 102 is carried by the annular surface portion 99 of the nozzle member 56 and extends into the annular clearance region 101. Thus machining or complicated casting operations when forming the boss member 52 are avoided. However, it will be appreciated that the stop 102 may be carried by the annular surface portion 98 of the boss member 52 is desired.
To positively locate the engaged position by preventing further counterclockwise rotation of the nozzle member 56 within the boss member 52 past the engaged position shown in FIG. 2, respective locating engagement surfaces 104 and 106 are carried by the boss member 52 and the nozzle member 56. In the illustrated embodiments, one 106 of the locating engagement surfaces is provided on the stop 102 carried by the nozzle member 56, and the other 104 of the locating engagement surfaces is provided on the lug 88 of the boss member 52. It will be seen that the stop 102 and locating engagement surface 106 project generally radially outwardly from the nozzle member 56 annular surface portion 99 into the annular clearance region 101. The other 104 of the mating locating engagement surfaces provided on the boss lug 88 comprises a surface facing generally inwardly towards the axis of the nozzle boss cylindrical inner surface 60.
In FIG. 2 it will be seen that further movement of the nozzle member 56 axially into the boss member 52 is prevented by suitable axial limiting surfaces, although the precise location is not critical. At least two pairs of alternative axial limiting surfaces exist, any one set of which may be the first to actually engage depending upon the precise fit. These are as follows. First, as mentioned above, in the inserted position the nozzle insertion end 66 bears against the boss member annular protrusion 96, portions of which thus comprise axial limiting surfaces. Second, from FIG. 2 it will also be appreciated that, either alternatively, or in addition to the nozzle end 66 and the protrusion 96, portions of the confronting surfaces 84 and 85 of the boss member 52 and flange 74 may comprise axial limiting surfaces.
In an important aspect of the invention, the stops 102 and, more particularly, the locating engagement surfaces 104 and 106, are located and configured such that insertion of the nozzle member 56 within the boss member 52 and subsequent rotation to the engaged or locking position is in the same direction as torque is exerted on the nozzle member 56 when a cap, such as the FIG. 1 cap 38, is removed. For the configuration illustrated, tests have shown that torques in excess of 900 foot-pounds can be resisted in the counterclockwise direction as a cap is removed without damage to the nozzle assembly 50.
For maintaining or locking the nozzle member 56 in its engaged position within the boss member 52, the aforementioned pin element 78 (FIG. 2) is provided and is inserted through the mating apertures 82 and 80 in confronting surfaces 84 and 85 of the boss and nozzle members 52 and 56. Due to the much lower torques involved when installing a cap 38 or hose fitting compared to removing a cap, sufficient shear resistance may be provided in a pin element 78 of reasonable size. While the illustrated the pin element 78, as well as apertures 80 and 82, are of general circular configuration, it will be appreciated that this is merely a matter of design choice, and that suitable pin elements 78 may be provided in the variety of sizes and configurations.
With the present invention, the locating engagement surfaces 102 and 104 positively locate the engaged position such that the apertures 80 and 82 can always be aligned even though they are predrilled or preformed prior to assembly of the nozzle member 56 to the boss member 52. This is particularly beneficial in the case of field replacement of a nozzle member 56, as no drilling operations are involved.
Preferably the aperture 82 formed in the boss member 52 is sufficiently deep such that a space 108 (FIG. 2) thicker than the flange 74 remains between the end of the pin 78 and the bottom wall 110 of the aperture 82. This facilitates removal of the pin 78, which can simply be driven out of the flange 74 aperture 80 into the space 108, allowing clockwise rotation of the nozzle member 56 within the boss member 52 for removal.
As may be seen from FIGS. 2, 3 and 4, the aperture 82 is configured as a slot or notch-like recess communicating radially with the boss member 52 opening, thus providing easy access to the pin element 78 following removal of the nozzle member 56. Another advantage of this particular configuration is that loss of the pin element 78 by dropping within the hydrant barrel 54 is substantially precluded. Yet another advantage, when the recess 82 is circumferentially located at the bottom as illustrated, is that the recess 82 serves as a drain for any water which enters the space between the boss member 52 and the nozzle 56.
In the preferred configurations illustrated, the nozzle assembly 50 comprises a plurality of equally spaced substantially identical boss lugs 88 extending generally circumferentially along the cylindrical inner surface 60, an identical plurality of equally spaced substantially identical nozzle lugs 92 extending generally circumferentially along the cylindrical outer surface 62, and another identical plurality of equally spaced substantially identical stops 102 projecting from the annular surface portion 99.
Considering the various elements of the boss member 52 in somewhat greater detail, the locating engagement surfaces 104 provided on the boss lugs 88 are perpendicular to a radius extending from the axis of the boss member. These surfaces 104 intersect the inside cylindrical surface 60 of the boss member 52, geometrically defining respective chords. The chords together subtend approximately one-half of the 360° angular distance around the inner cylindrical surface 60, preferably altogether slightly less than one half this angular distance. The locating engagement surfaces 104 are wide enough to provide shear resistance and a bearing surface. The cylindrical inner surface 60 with which the engagement surfaces 104 intersect is slightly larger in diameter than the nozzle lugs 92, permitting the nozzle member 56 to fit within the boss member 52.
Considering the various corresponding and mating surfaces of the nozzle member 56, the nozzle lugs 92 are separated by flat surfaces 112 tangential to the nozzle member outer cylindrical surface 62 at the midpoint of each pair of nozzle lugs 92. The flat surfaces 112 are configured to align with the boss lug mating locating engagement surfaces 104 during initial insertion of the nozzle member 56 into the boss member 52.
The locating engagement surfaces 106 carried by the stops 102 comprise flat surfaces tangential to the nozzle member outer cylindrical surface 62 at the center line of each of the nozzle lugs 92. In particular, the locating engagement surfaces 106 extend from the nozzle lug center lines in one direction only until they intersect similar insertion engagement surfaces 114 comprising planar extensions of the flat surfaces 112 separating the nozzle lugs 92. The insertion engagement surfaces 114 are configured to engage planar extensions 116 of the locating engagement surfaces 104 carried by the boss lugs 88, the planar extensions 116 comprising mating insertion engagement surfaces. The insertion engagement surfaces 114 and 116 thus serve to prevent rotation from the inserted position in a direction opposite to that which is necessary to reach the engaged position.
The remaining regions 118 of the annular surface portion 99 of the nozzle member 56 not taken by the stop 102 are portions of a cylindrical surface. In the preferred configuration illustrated, it will be seen that there are four such regions 118, involving a total angular distance of approximately 180°.
Accordingly, it will be appreciated that the present invention provides an improved fire hydrant nozzle. Inadvertent removal of the nozzle member 56 as a result of torque when a cap is removed is effectively prevented by the locating engagement surfaces 104 and 106, while rotation in the opposite direction is prevented by the pin element 78. The slot-like aperature 82 in the boss member 52 and the mating aperture 80 and the nozzle flange 74 can always be aligned even though they are preformed, this being a result of the positive locating action of the surfaces 104 and 106. The nozzle member may easily be replaced by driving in the pin element 78, and unscrewing the nozzle member.
While specific embodiments of the invention have been illustrated and described herein, it is realized that numerous modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit and scope of the invention.
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A fire hydrant nozzle assembly which permits a bronze fire hydrant nozzle to be readily and simply attached to a cast iron hydrant barrel without the use of lead caulking, screw threads, or other methods generally requiring machining. Un-intentional removal of the bronze nozzle as a result of the application of relatively high torque typically required to remove a protective cap is effectively prevented. To provide these features, a bronze nozzle member is retained within a hydrant boss member by means of a bayonet type or breech lock type mechanism involving cooperating lugs, and a resilient seal such as an O-ring is provided. For locking the nozzle member in its installed position, a pin element passes through a pair of corresponding apertures in confronting surfaces of the boss and nozzle members. The installed position is positively defined by respective locating engagement surfaces carried by the boss and nozzle members, which surfaces serve to limit rotation. The corresponding apertures can always be aligned even though they are pre-formed or pre-drilled. Preferably, the locating engagement surfaces are configured and positioned such that locking rotation of the nozzle following insertion into the boss occurs in a direction opposite to the direction of the threads on the outlet end of the nozzle such that when the nozzle cap is removed the locating engagement surfaces resist the torque involved.
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This application claims priority under 35 U.S.C. §§119 and/or 365 to 9704859-9 filed in Sweden on Dec. 23, 1997; the entire content of which is hereby incorporated by reference.
TECHNICAL FIELD
This invention relates to a method and a device for regulating the transmitted phase of a signal in an antenna device.
BACKGROUND
Within systems based on electromagnetic signal transmission, for example radar systems and systems for wireless communication, phase-controlled antennas are a technique which has many advantages. These advantages include the fact that phase-controlled antennas greatly increase the ability to adaptively vary the directivity of an antenna, which for example makes it possible to have the antenna's radiation diagram, the antenna beam, follow a moving object without mechanical movement of the antenna.
As the directivity of a phase-controlled antenna can be varied adaptively, it is possible in a system for wireless communication, for example a mobile telephone system, to direct the antenna beam towards only those directions where there are subscribers at the moment. In this way, the total transmitted power can be reduced while at the same time maintaining communication with all the subscribers in the system.
Because of the ability to vary the directivity of phase-controlled antennas, it is also possible, using a mass-produced phase-controlled antenna, to individually design the antenna's coverage depending upon the topography of the area in which the antenna is located. For example, antennas which are located along motorways can be given a main coverage which coincides with the lengthways extent of the road and antennas which are placed at intersections can be given a main coverage which coincides with the extent of the intersection.
A phase-controlled antenna is normally formed of a large number of antenna elements whose antenna beams together form the resultant antenna beam of the phase-controlled antenna. The resultant antenna beam is controlled by varying the phase of the signals that are sent out by the antenna elements making up the antenna. In other words, in a phase-controlled antenna it is of the utmost importance that the phase of the signal transmitted by each antenna element is the intended one.
The antenna elements in a phase-controlled antenna often include a phase shifter which causes the signal to assume the required phase, and a power amplifier, PA, connected to the phase shifter, which amplifies the signal. A problem in this context is that the power amplifier can affect the phase of the signal transmitted by the antenna element. These phase shifts in the power amplifier arise, for example, as a result of the temperature in the power amplifier varying, which can occur when the output energy varies.
In other types of antenna than phase-controlled group antennas there can also be power amplifiers which can affect the phase of the signal in an unwanted way. An example of such an antenna is a group antenna which is not phase-controlled, in other words an antenna whose beam is not controlled electronically but where the antenna as a whole still consists of a number of antenna elements. Each antenna element in such a group antenna can include a power amplifier. The phase of the signal which is fed into each antenna element in this type of group antenna may not be affected by the power amplifier.
Phase shifts which arise due to power amplifiers in systems of the type described above can be compensated for by the power amplifier being reconnected to the phase shifter in a control loop. In such a control loop there are means for controlling the phase shifter whereby the phase shifter is made to cause the power amplifier to assume the required phase. A problem in this context is that many types of phase shifter do not have so-called periodic behaviour, in other words the phase shifter only has a certain linear range within which it is required to work. Phase shifters without periodic behaviour should be reset to a working point, a so-called modulation position, within the linear range before the phase shifter has gone outside its linear range.
There is therefore a need at certain times to reset a phase shifter which is part of an antenna element of the types described above to a certain predetermined modulation position. Resetting of phase shifters should not be carried out when the signal transmitted by the antenna element contains information, as the resetting could then affect the transmission of information. An additional requirement is that the modulation position to which the resetting of the phase shifter is carried out should be such that the phase shifter cannot go outside its linear range before the next resetting occasion.
Document WO94/10765 describes a device for linearization of a power amplifier in a mobile telephone system of the TDMA type. The linearization of power amplifiers according to this document can only be carried out at certain predetermined times, so-called linearization time slots. This could be said to result in a rather inflexible system.
Documents U.S. Pat. No. 5,426,641 and JP 9 116 474 describe devices for regulating the phase of the transmitted signal in systems for wireless communication. The devices according to these documents include measuring the phase position or parameters relating to the phase position of the component which exhibits variations in phase, after which measurements calculations are carried out to find out what modulation position the component in question should be reset to. These appear to be rather complex and thus expensive solutions.
SUMMARY
The problem which is solved by the invention is thus to be able to regulate correctly the phase of the signal in a device which is part of a system for electromagnetic signal transmission, preferably an antenna element in an antenna which is part of a system for wireless communication, without the phase regulation having an adverse effect on the transmission of information within the system.
The device which is regulated according to the method preferably comprises a phase shifter which has a linear and a non-linear range, a power amplifier which amplifies the signal from the phase shifter and means for controlling the modulation position of the phase shifter, by which the transmitted signal is given the required phase position.
The above-mentioned problem is solved according to the invention by utilizing advance knowledge of when the transmitted signals contain information and when they do not. At times when the signal does not contain information, the phase shifter is reset to a certain predetermined modulation position, which preferably lies within the linear range of the phase shifter.
In a preferred embodiment the invention is used in a TDMA mobile telephone system of the GSM type.
DESCRIPTION OF THE FIGURES
In the following the invention will be described in greater detail utilizing examples of preferred embodiments and with reference to the attached figures, where
FIG. 1 shows a device in which the invention is used to regulate transmitted phase, and
FIG. 2 shows diagrammatically the phase characteristics of a phase shifter with non-periodic behaviour, and
FIGS. 3 a and 3 b show diagrammatically a “burst” in a GSM system.
DETAILED DESCRIPTION
FIG. 1 shows an example of a device 100 in which the invention can be used. The device 100 comprises a phase shifter 110 and a power amplifier 120 connected in series with the phase shifter 110 . The phase shifter 110 and the power amplifier 120 are in addition connected to each other in a control loop, which also includes a regulator. In a preferred embodiment the regulator consists of an integrator 130 . A phase detector 140 is connected to the integrator 130 , but the integrator 130 can also be connected to an external control device, which is shown by a dotted line. in a preferred embodiment the phase shifter 110 consists of one or more varactor diodes, which together form a phase shifter whose linear range suitably exceeds 360°.
The phase detector 140 is preferably connected so as to detect φ in and φ out via a (not shown) directional coupler which connects a small part of the signal in question to the phase detector.
The phase detector 140 thus detects the difference between the phase of the input signal to the device, φ in , and the phase of the signal transmitted by the power amplifier 120 , φ out . In a preferred embodiment of the invention, the changes in the difference between φ in and φ out are used to detect phase shifts in the power amplifier. Detection of phase shifts in the power amplifier should not be carried out by detecting whether φ in and φ out have the same value, since for example differences in electrical wavelength, for example different length connections between the phase detector 140 and the above-mentioned directional couplers, can cause different values of φ in and φ out at their connection points to the phase detector 140 .
However, in the event of constant phase position of the output signal from the power amplifier, the difference between φ in and φ out will be constant. In other words, if the difference between φ in and φ out is constant, no phase shifts have occurred. Therefore, if the phase detector 140 detects that the difference between φ in and φ out has changed, the phase shifter 110 will be regulated via the regulator 130 so that the difference between φ in and φ out attains a required constant value.
FIG. 2 shows the characteristics of a normal type of phase shifter. As shown in the figure, the phase shifter has a linear range, φ 1 -φ 2 , within which, in the present case, the phase shifter is required to work. In other words, the modulation position of the phase shifter is required to lie within the linear range. As also shown by FIG. 2, the modulation position of the phase shifter will be outside the linear range if the compensation for the phase deviation of the power amplifier exceeds the difference between the point at which the phase shifter begins to operate and any of the distances to the limits, φ 1 , φ 2 , of the commencement of the non-linear range.
In order for the modulation position of the phase shifter 110 not to come outside the linear range, according to the invention the phase shifter 110 is reset at certain times to a certain predetermined modulation position φ in1 within the linear range, This resetting should suitably be carried out in such a way that the following conditions are fulfilled:
1. From the modulation position φ in1 to which the phase shifter is reset, the phase shifter must not be able to go outside its linear range before the next resetting takes place.
2. Resetting of the phase shifter should be carried out when no information is being transmitted in the RF signal, in other words the output signal from the power amplifier.
In a preferred embodiment the invention is used in a mobile telephone system of the TDMA type, preferably a GSM system. In the following therefore it is described how the two conditions listed above for resetting the phase shifter 110 are fulfilled in a GSM system.
FIGS. 3 a and 3 b show diagrammatically the construction of the signal and the signal format in a GSM system. During what is known as the guard time at the end of the message (“burst”) no information is transmitted in the RF signal. In addition, the power varies during the guard time, first dropping and then rising. FIG. 3 b also shows a frequency change, the power of the first frequency f 1 is stepped down during the guard time and increased on the frequency f 2 which is to be used during the next “burst”.
The variation in power during the guard time can thus be used as a sign that no information is being transmitted and that resetting of the phase shifter 110 can therefore be carried out. In addition, the phase variation of the power amplifier 120 is fairly small during that part of a “burst” which is used for transmitting information in the RF signal, as frequency and input power, which are parameters which affect the phase variation of the power amplifier, are kept relatively constant when information is being transmitted in the RF signal. On the other hand, the frequency and the input power can vary during the guard time, which means that the regulation of the power amplifier 120 by the phase shifter 110 is mainly carried out during the guard time. After the guard time there are usually no great phase variations occurring in the device 100 . To sum up, in other words detection that the power of a signal has dropped below a certain level P 1 is used as an indication that there is a guard time, which means that resetting of the phase shifter can commence.
Resetting of the phase shifter takes up a certain length of time. It is realized that the time for resetting should not exceed the time which passes before the RF signal once again contains information. Suitably, the exceeding of the power level P 1 by the signal can be used as an indication that the resetting should have been completed. In an alternative embodiment, the resetting can be “time-controlled”. The term “time-controlled” here means that the resetting can be adjusted to always take up the same length of time, as it is known from the system specification etc, how much time will pass before the information starts to be present in the RF signal after a break in the information, in the GSM system between two “bursts”.
When resetting is completed, it is permissible for the phase shifter 110 to vary up until the next time for resetting, however, of course controlled by the regulator 130 .
In an alternative embodiment of the invention, the fact that the phase variations of the power amplifier 120 mainly occur during the guard time is used in a somewhat different way than that described above. In this alternative embodiment it is assumed that the phase variations of the power amplifier 120 during that part of a “burst” when information is transmitted in the RF signal are negligible in relation to the phase variations during the guard time. Based on this assumption, the modulation position of the phase shifter 110 is reset in the way described above, but the phase shifter is not allowed to vary after the resetting until the next resetting occasion. Instead, the modulation position of the phase shifter 110 is kept constant in one and the same position until the next resetting occasion.
The position in which the phase shifter 140 is kept constant in this alternative embodiment is a position which the phase shifter assumes after the resetting is completed, but before information has started to be transmitted in the RF signal, in other words in the example shown before the guard time ends. In other words, in this embodiment of the invention the time interval for the resetting concluding to the information commencing to be transmitted in the RF signal must be sufficient for regulation of the phase shifter to take place. In FIG. 3 b this is shown as a time interval Δt between the power level P 1 and a second power level P 2 which is found immediately before the RF signal begins to contain information, and at which power level P 2 “locking” can be carried out.
In the two embodiments of the invention described above, it has been assumed that the device 100 is equipped with means for detecting the variations in power arising in connection with guard time. These means—shown connected to the regulator by a dotted line—can be implemented in a large number of ways well-known to those skilled in the field and are therefore not described in further detail here.
In addition, the device 100 in accordance with the invention can advantageously be equipped with means for controlling the regulation process. These means can then be connected to the regulator at the above-mentioned dotted line. Also, such means for controlling the regulation process can be implemented in a large number of ways well-known to those skilled in the field and are therefore not described in greater detail here.
Controlling of the control process in connection with resetting can also be carried out by the phase shifter 110 for a certain predetermined time being reset to one and the same position. This period of time should then be so adjusted that it corresponds to the time between the resetting commencing and the time when regulation of the phase shifter to a required constant position has been able to be carried out, suitably a time before information starts to be transmitted in the RF signal. It is also possible that the position to which the phase shifter is reset can vary between the resetting occasions.
In addition, it is the case that the detection of the guard time and different positions during the guard time are used as an indication that information is not being transmitted in the RF signal. This detection that information is not being transmitted in the RF signal can also be carried out in other ways. For example, it is possible that the means for detecting variations in power of the signal can be replaced by a connection to the system, in the case of GSM a base station, by means of which connection the base station provides information about when information is being transmitted or is intended to be transmitted in the RF signal.
The invention is not limited to the embodiments described above, but can be freely varied within the scope of the following patent claims.
It is, for example, possible to use the invention in other applications in which there are phase-controlled antennas, for example radar applications.
The invention can also be used in other applications where there is a need to detect and control the phase of a signal from a particular component, which component does not necessarily need to be a power amplifier.
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The phase of a transmitted signal is regulated in a device which is part of a system for electromagnetic signal transmission. The transmitted signal has periods when it contains information and periods when it does not contain information. The modulation position of a phase shifter which has a linear and a non-linear range is controlled. Power of the signal is amplified. Unwanted phase shifts in the signal transmitted by the device caused within the power amplifier are detected, and the information content of the signal is detected. The phase shifter is reset to a particular predetermined modulation position in the event of detection of the absence of information in the signal. The predetermined modulation position to which the phase shifter is reset is preferably situated within the linear range of the phase shifter.
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BACKGROUND OF THE INVENTION
This invention relates generally to equipment supports, and more particularly, to portable equipment utilized in conjunction with motion picture film or video cameras.
In employing motion picture film cameras or video cameras to capture a sequence of images, it is extremely important to maintain the camera which is used in as stable a position as possible in order to obtain a high quality result. This is important in eliminating the effects of undesirable camera motion while in use. This is particularly desirable when employing such cameras under conditions wherein it is necessary or desirable for the camera to be mobile, or subjected to movement to acquire the images which are desired.
In order to overcome these problems, and to reduce the expense encountered in producing motion picture films and video productions, the "Steadicam®" portable camera stabilizing device was developed- Using this device, which has become a de-facto standard in the industry, high quality results have been obtainable in a variety of circumstances. This is so even when the camera operator walks or runs with the camera because of the attendant increase in stability, particularly in stabilizing quick angular deviations along the axes of pan, tilt and roll, which previously could not be adequately controlled.
Further detail regarding the "Steadicam®" camera stabilizing device may be found with reference to U.S. Pat. Nos. 32,213 (formerly U.S. Pat. No. 4,017,168); 4,156,512; and 4,474,439. A key component of this device is the so-called "arm" which serves as the interface between the frame which supports the camera and its ancillary components (e.g., battery packs, view finders, remote control equipment, etc.) and the body harness which is worn by the camera operator. Further detail regarding this support arm may be found with reference to U.S. Pat. No. 4,208,028.
The support arm disclosed in U.S. Pat. No. 4,208,028 is generally comprised of a pair of substantially friction-free arm sections which are rotatably and pivotally interconnected at a hinge bracket. Each arm section is formed as a parallelogram, and is provided with segmented springs which are designed to apply a constant force to compensate for the weight applied to the end of the support arm. As a result of this, the weight carried by the support arm is spatially decoupled from the body mounting to increase isolation of the weight from the operator as well as the camera support itself.
A principal design feature of the support arm, which is critical to proper functioning of the "Steadicam" camera stabilizing device, is the ability of the support arm to support the fixed weight of the overall system from its lowest to its highest point of articulation with a relatively constant amount of positive "buoyancy". This ability is generally referred to as "iso-elasticity" and the maintenance of such iso-elasticity is quite critical in ensuring effective operations of the "Steadicam®" camera stabilizing device.
The mechanical principles and geometry of the support arm disclosed in U.S. Pat. No. 4,208,028 are perfectly valid for a variety of different types of cameras. However, a particular design was only found to be valid for a particular type of camera, primarily due to weight considerations, and was found not to be readily adaptable to different types of cameras. Nevertheless, in practice, use of the "Steadicam®" camera. stabilizing device has generally come to require its use in conjunction with different types of cameras. This is because practicalities such as space availability and cost considerations tend to prevent the dedication of different camera stabilizing devices to the different cameras necessary for a particular production. Consequently, means for adjusting the support capabilities of the arm of the "Steadicam®" camera stabilizing device have become an ever-increasing consideration.
Responding to this need, adjustability has been provided for by altering the length of the springs used in conjunction with the arm sections of the support arm in order to increase or decrease the load characteristics of the resulting spring set. While this allows cameras of different weight to be supported by the arm, it has been found that the desired positive buoyancy for the arm is only valid in one position of its vertical articulation. In other words, the important feature of iso-elasticity is lost. What is more, the adjustments required for altering spring length are significant and time consuming, and are therefore preferably avoided.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the present invention to provide an adjustable, iso-elastic support arm for a stabilizing device.
It is also an object of the present invention to provide an adjustable, iso-elastic support arm for a stabilizing device which can operate in conjunction with camera equipment to obtain stabilizing motion picture film or video images.
It is also an object of the present invention to provide an adjustable, iso-elastic support arm for a camera stabilizing device which can effectively support cameras of different weights.
It is also an object of the present invention to provide an adjustable, iso-elastic support arm for a camera stabilizing device which can receive cameras of different weights while maintaining a positive buoyancy for each camera, maintaining its iso-elastic character throughout its anticipated vertical articulation.
It is also an object of the present invention to provide an adjustable, iso-elastic support arm for a camera stabilizing device which is easily adjusted to accommodate cameras of different weight making use of simplified adjustments which are easily performed and well suited to field use.
It is also an object of the present invention to provide an adjustable, iso-elastic support arm for a camera stabilizing device which can effectively accommodate cameras of different weight without in any way compromising the other operative characteristics of the camera stabilizing device when in use.
These and other objects which will be apparent are achieved in accordance with the present invention by providing the support arm for the camera stabilizing device with a tensioning assembly which is mated to the support arm in a fashion which permits continuous adjustment of the geometric relationship between the end points of the tensioning assembly and the remaining structures which comprise the support arm. This can include adjustments in the frame of the support arm, but preferably involves adjustment of an end point of the tensioning assembly relative to the frame of the support arm using one of several different cable and drum arrangements coupled with a spring of appropriate size and tension.
For further detail regarding preferred embodiment support arms produced in accordance with the present invention, reference is made to the detailed description which is provided below, taken in conjunction with the following illustrations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a camera stabilizing support of the prior art, as used, but without a camera mounted thereon.
FIG. 2 is a side elevational view of the support arm of the camera supporting apparatus of FIG. 1.
FIGS. 3a and 3b are schematic diagrams showing a mechanical model for the arm links which form the camera supporting apparatus shown in FIGS. 1 and 2.
FIGS. 3c and 3d are vector diagrams related to the mechanical models of FIGS. 3a and 3b.
FIGS. 4a and 4b are schematic diagrams showing a first alternative means for adjusting the physical properties of the arm links.
FIG. 5 is a schematic diagram showing a second alternative means for adjusting the physical properties of the arm links
FIG. 6 is a schematic diagram showing a first alternative embodiment, cable and drum arrangement produced in accordance with the present invention.
FIG. 7 is a schematic diagram showing a second alternative embodiment, differential drum arrangement produced in accordance with the present invention.
FIG. 8 is a vector diagram related to the schematic illustration of FIG. 7.
FIGS. 9, 10 and 11 are partial, sectional views of adjustment devices for receiving the cables associated with the differential drum arrangement of FIG. 7.
FIG. 12 is a perspective view showing a camera stabilizing support incorporating an arm section fitted with a tensioning apparatus produced in accordance with the present invention.
FIG. 13 is a side elevational view of an arm section of the support arm of FIG. 12.
FIG. 14 is a top plan view of the arm section of FIG. 13, showing cable connections.
FIG. 15 is a schematic plan view of a hinge for interconnecting the arm sections of the support arm.
FIG. 16 is a top plan view of a preferred embodiment hinge mechanism.
FIG. 17 is a side elevational view of the hinge mechanism of FIG. 16.
In the several views provided, like reference numbers denote similar structures.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1 and 2 illustrate a support apparatus of the type which is conventionally used to obtain stabilized motion picture film and video images, and which is generally offered for sale by Cinema Products Corporation under the trademark "Steadicam®". As illustrated, the support arm for the apparatus includes a pair of parallel upper arms links 2, 4 which are pivotally coupled at one end to a connector hinge bracket 6. The other ends of the upper arm links 2, 4 are pivotally coupled to an upper arm medial hinge bracket 8. A second pair of parallel forearm links 10, 12 are pivotally coupled between a forearm medial bracket 14 and a camera support bracket 16. A camera mounting pin 17 is provided in the camera support bracket 16.
The upper arm medial bracket 8 and the forearm medial bracket 14 are rotatably coupled together along one side by a hinge 18. The connector hinge bracket 6 is rotatably coupled at its center to one end of a lower support hinge plate 20. The other end of the lower support hinge plate 20 is rotatably coupled to a fixed support block 22 by a pin 23. A spring 21, through which the pin 23 extends, biases the lower support hinge plate 20 in a clockwise direction.
One end of a tension spring 24 is coupled to the end of the upper arm link 2 which is pivotally coupled to the upper arm medial hinge bracket 8. The other end of the tension spring 24 is coupled to one end of the tension spring 26 by a section of cable 28 which rides on and around a pulley 30 which is rotatably coupled to the upper arm link 2. The other end of the tension spring 26 is coupled to one end of a tension spring 32 by a section of cable 34 which rides on and around a pulley 36 which is rotatably coupled to the upper arm link 4. The other end of the tension spring 32 is coupled to the end of the upper arm link 4 adjacent to the connector hinge bracket 6.
Similarly, one end of a tension spring 38 is coupled to the end of the forearm link 10 adjacent to the camera mounting bracket 16. The other end of the tension spring 38 is coupled to a tension spring 40 by a cable 42 which rides on and around a pulley 44 which is rotatably coupled to the forearm link 10. The other end of the tension spring 40 is coupled to one end of a tension spring 46 by a cable 48 which rides on and around a pulley 50 which is rotatably coupled to the forearm link 12. The other end of the tension spring 46 is coupled to the end of the forearm link 12 adjacent to the forearm medial hinge bracket 14.
A weight, such as a camera which is supported at the support bracket 16, behaves as an object in free space beyond gravity since the upward forces which the tension springs 24, 26, 32 and 38, 40, 46 exert, in effect, counteract gravity. The weight tends to travel in a straight line until influenced otherwise and tends to retain the same angle until influenced otherwise. As a result, the upper arm links 2, 4 roughly correspond to the upper arm of the user and the forearm links 10, 12 roughly correspond to the user's forearm, in terms of their three dimensional geometry, as the support arm is used either high, low, or to either side.
Referring now to FIG. 3, the mechanical and geometric considerations surrounding operations of the support arm links 2, 4 (as well as the support arm links 10, 12) are best described schematically as a four bar mechanism with a diagonal spring 51 for carrying a load of a given weight (see FIG. 3a). In this model, the right-most end 52 carries a load P. Note that if the load P were placed at the point 53, where the spring 51 joins the lower bar 54, there would be no need for the upper bar 55 and the connecting link 52 between the upper bar 55 and the lower bar 54.
For purposes of analysis, the load P can be replaced by a load and a couple., as shown in FIG. 3b. The upper bar 55 supplies a reactive force R to form the couple Rd, which is equal and opposite to the couple Pa. The moment caused by the couple Pa will be equalized by use of the upper bar 55 in conjunction with the lower bar 54. The analysis can now be simplified by looking at this reduced mechanism, and by considering the load applied at the point 53 where the spring 51 joins the lower bar 54, as shown in FIG. 3c.
To generalize this analysis, an angle D is shown at something other than 90°. The distance d is the separation between the bars 54, 55. The distance 1 is the separation between the pivots 53, 56 (see FIG. 3a) on the lower bar 54. S is the length of the diagonal (the spring 51). The length S is given by the equation: ##EQU1##
Since all of the pivots are free to rotate, the forces exerted by the various members must act along their axes. Proceeding to a vector analysis, and referring now to FIG. 3d, the force exerted by the lower bar 54 can be represented by a vector C parallel to the lower bar. Likewise, the force exerted by the spring 51 can be represented by a vector T parallel to the spring. The sum of these vectors C, T is a vertical force (-P) equal and opposite to the load P in order to produce equilibrium. The sense of the vectors necessary to achieve this is as shown in FIG. 3d.
It can be seen that since the vectors T and C are parallel to the spring 51 and the lower bar 54, respectively, and 10 since their sum must be vertical, the vector diagram forms a triangle similar to the triangle formed by the physical parts of the arm link mechanism. The sides of these triangles are in the following proportion: ##EQU2##
The forces are proportional to the lengths of the members to which they relate, as follows. ##EQU3##
The load P to be carried, divided by the separation d between the lower bar 54 and the attachment point 57 (see FIG. 3c) for the spring 51, defines a constant of proportionality.
If the device is a simple truss, with no movement, then no spring is necessary. Rather, a simple bar will do, and the force supplied will be: ##EQU4##
If the device is to exhibit motion, but equilibrium is required in only one position, then the spring 51 must provide the force: ##EQU5## Distances can then be calculated as previously indicated.
However, if, as is preferred in accordance with the present invention, the device is to maintain equilibrium in all positions, the spring 51 must be able to stretch for a distance equal to the length (S) of the diagonal. Some or all of the spring 51 must be placed outside of the diagonal to give it room to stretch. The spring rate K (i.e., the ratio between the spring force and the stretch) is the load P to be carried divided by the distance d: ##EQU6##
One way to provide sufficient room for expansion of the spring 51, as described in U.S. Pat. No. 4,208,028, is to separate the spring into sections (e.g., the springs 24, 26, 32 of FIG. 2) which are serially connected by cables (e.g., the cables 28, 34 of FIG. 2) which are run over a cooperating series of pulleys (e.g., the pulleys 30, 36 of FIG. 2). One section is placed over the upper bar 55. Another section is placed below the lower bar 54. A third section is placed along the diagonal (between the end points 53, 57). The sum of the distances allowed for each section to stretch must equal the maximum diagonal distance (the length S).
The foregoing describes a system designed to be in equilibrium in all positions for a single load (i.e., an iso-elastic system). If the load is to vary, either the spring rate, the distance d, or both, must change. Referring again to equation (6), K=p/d, where K=spring rate, if K changes, the load P that can be carried changes proportionally, or:
P=dK (7)
Similarly, if d changes, P changes proportionally. Since the spring rate K is an inherent characteristic of a given spring, based on its physical properties, changing the spring rate can only be accomplished by changing the springs (which is not easily done).
However, in accordance with the present invention it has been found that the distance d is more easily changed, for example, by simple screw adjustments. As shown in FIGS. 4a and 4b, this can be accomplished through an arrangement in which the spring is distributed (sections 60, 61, 62) among the lower and upper bars 54, 55 and the diagonal, and which employs scissors-type mechanisms 64, 65 for adjusting the distance d so that the distance between the lower bar 54 and the upper bar 55 is changed. Alternatively, as shown in FIG. 5, the lower bar 54 can incorporate a canister 70 for holding the necessary spring segments, pulleys and cables, eliminating the need to adjust the distance between the bars 54, 55. Instead, only the point of origin 71 for the spring system needs to be changed in order to adjust the distance d (employing a simple jackscrew adjustment 72, for example). For this reason, and since the several spring segments can further, if desired, be replaced by a single spring of appropriate characteristic, this latter approach is presently preferred.
Further improvements can be achieved in accordance with the present invention by taking advantage of pulley (or drum) ratios. Variations of this approach are possible, depending upon the desired spring configuration.
Referring to FIG. 6, one such approach is to utilize a straight drum ratio. In this embodiment, the spring is split into two sections 80, 81. One spring section 80 extends along the diagonal. The other spring section 81 is housed in a canister 82 associated with the lower bar 54. The illustrated structure is simplified by elimination of the upper bar 55. The diagonal spring 80 terminates at the load adjustment point 83, at one end, and in one or more parallel cables 84, at its other end. The cables 84 wind onto a first drum 85. The spring 81 in the canister 82 terminates at the end 86 of the canister, at one end, and in one or more parallel cables 87, at its other end. The cables 87 wind onto a second drum 88. In this configuration, the drum 88 is smaller in diameter than is the drum 85. The drums 85, 88 are fixed relative to each other, or in practice may be unitary in construction. The use of multiple cables 85, 87 will be discussed more fully below.
The drum ratio R is equal to R L /R S . The spring rates are selected by means of the equation:
1/K=1/K.sub.D +R.sup.2 /K.sub.P (8)
Wherein:
K=P/d (see equation 6)
K D =Spring rate of the diagonal spring 80.
K P =Spring rate of the spring 81 in the canister.
Also to be considered in the selection of springs, such as the springs 80, 81, is that:
1. The diagonal spring 80 must fit in the diagonal when it is stretched to its proper length for the support arm in its uppermost position.
2. The canistered spring 81 must fit in the canister 82 when stretched to its proper length for the support arm in its lowermost position.
3. The force exerted by the diagonal spring 80, in any position, is equal to: ##EQU7## 4. The force exerted by the spring 81 in the canister 82, in any position, is equal to: ##EQU8## 5. In practice, an appropriate diagonal spring 80 for meeting the first condition above may be found empirically. Its deflection at any position may then be calculated.
6. If the deflection at any position of the diagonal spring 80 is C D , and the deflection of the canistered spring 81 is C C at that same position, then:
C.sub.C= (S-C.sub.D)/R (11)
Referring now to FIG. 7, another approach makes use of a differential drum arrangement. This method utilizes only one spring 90, preferably in a canister 91, since very large ratios are made possible with this arrangement. In such case, the diagonal is formed by one or more parallel cables 92, depending on the load to be accommodated, extending from the load adjustment point 93 to a first drum 94. The spring 90 is fixed to one end 95 of the canister 91, at one end, and its free end 96 receives one or more pulleys 97. One or more cables 98, operating in parallel, extend from the drum 94 (from the side opposite the diagonal cable 92), wind once around the pulley 97, and terminate at a second, coaxial drum 99. In this configuration, the drum 99 is smaller in diameter than is the drum 94. There is no relative movement between the drums 94, 99.
The forces operating on the pulley 97 and the differential drum 94, 99 are shown in FIG. 8. T represents the force extending along the diagonal. F represents the force exerted by the spring. The equilibrium equation for the moments about the drums 94, 99 is:
TXR.sub.L =(F/2)XR.sub.L -(F/2)XR.sub.S (12)
From this, it is determined that:
F/T=R.sub.M =(2XR.sub.L)/(R.sub.L -R.sub.S) (13)
It can be seen that extremely large ratios are obtained with small differences in drum size. Indeed, as the radii of the two drums 94, 99 approach each other, this ratio increases without limit.
The force exerted by the spring 90 is governed by the equation:
F=(P/d)XSXR.sub.M (14)
Deflection of the spring 90 is governed by the equation:
C=S/R.sub.M (15)
The spring rate is determined by the equation:
K=(p/d)XR.sup.2.sub.M (16)
The spring 90, when stretched to its proper length with the support arm in its extreme lower position, must fit within the canister 91, while also allowing clearance for the pulley 97 and drums 94, 99. For heavier loads, toothed sprockets may be substituted for the drums and pulleys, and a chain may be used to replace all or part of the cable. For a camera support system, silent chain is preferably used.
Both the preceding embodiments can be arranged with the canister extending along the upper bar 55, if desired, with the load adjustment point situated at the end of the assembly opposite to the one shown and near the lower bar 54. In such the lower bar 54 cannot be eliminated.
As the load increases, the cables may be stressed beyond a safe value. Increasing cable size is possible, but only at the expense of larger pulleys and drums. This is not desirable since it makes the device clumsy and difficult to handle. Consequently, in such cases it is preferable to employ plural cables, thereby distributing the load between two or more cables, as desired. In order to share the load equally between such plural cables, some provision must be made to accommodate small differences in cable length. Otherwise, the shorter cable will carry all of the load.
Various means are available for accomplishing this. However, a preferred means for this is to employ a rocker 100 within the spring, with reference to FIG. 9 of the drawings. Rotation of the rocker 100 about the pivot point 101 serves to equalize cable length in straightforward fashion. It is only necessary to accommodate cable length discrepancies at one end of the cable. Consequently, if the cable end which receives the spring is compensated, the other end can attach directly, without compensation. For the differential drum configuration of FIG. 7, if plural cables are required for load control, the rocker 100 can be placed at the load adjustment point 93 (see FIG. 10).
Plural cables that start at the drum 94, wrap around the pulley 97, and terminate at the drum 99, need to be compensated at the drums 94, 99. As shown in FIG. 11, this can be accomplished by making one of the drums a center drum 105, while splitting the other drum into two drum sections 106 placed on either side of the center drum 105. The three drum members are then keyed to each other by means of a dowel 107. The holes 108 for the dowel 107 are bell-mouthed and slightly larger than the dowel 107. This then permits the two outer drums 106 to adjust for differences in cable length.
A practical embodiment incorporating the foregoing improvements is shown in FIGS. 12 to 14. Referring first to FIG. 13, a canister 110 extends along, and is affixed to (at 111, 112) the lower arm link 113 of a section 114 (in this case, the forearm section) of an operative support apparatus. A spring 115 extends longitudinally through the canister 110, and is affixed to one end 116 of the canister 110 by a mounting 117. The opposite end of the spring 115 is engaged by a mounting 118 which, in turn, pivotally receives a pulley 119 which is journalled for rotation at 120.
A series of cables operatively interconnect the pulley 119 (and accordingly, the spring 115) with an adjustable mounting 121 associated with the upper arm link 122. To this end, and referring now to FIGS. 13 and 14, a pair of cables 123 operatively interconnect the pulley 119 and a differential drum 125, while a single cable 124 operatively interconnects the differential drum 125 with the adjustable mounting 121. The differential drum 125 is comprised of a first, centrally located drum 126 and second, outwardly directed drums 127 for receiving the cables 123, 124. The drums 126, 127 are interconnected for rotation, in unison, about an axle 128. To be noted is that the drums 126, 127 have different radii, producing the mechanical advantage which permits the arm section 114 (and accordingly, the support arm) to be effectively controlled with only a single spring 115 rather than the plural springs which were previously required for effective control of such arm sections (and the support arm).
The adjustable mounting 121 is located at the load adjustment point for the arm section 114 (i.e., the load adjustment point 83, 93), and is in general alignment with the adjacent pivot 129 associated with the upper arm link 122. The adjustable mounting 121 generally includes a fixed housing 130 which receives an adjustment screw 131 (or in the alternative, an adjustment knob) which engages a swivel mounting 132. The swivel mounting 132 incorporates a recess 133 for receiving the end 134 of the cable 124, completing the operative interconnections between the tensioning apparatus and the arm section 114. The adjustment screw 131 variably engages the swivel mounting 132 (i.e., a jackscrew fitting), moving the swivel mounting 132 along a line which extends through the pivot 129 of the upper arm link 122. The swivel mounting 132 rotates about a pivot, at 135, to accommodate variations in the angle assumed by the cable 123 responsive to adjustments of the screw 131. Varying the "height" of the swivel mounting 132 relative to the pivot 129 of the upper arm link 122 causes adjustment of the arm section 114 to accommodate loads (e.g., a camera) of different weight placed upon the support apparatus.
FIG. 12 shows a camera stabilizing apparatus 140 which incorporates the tensioning system illustrated in FIGS. 13 and 14. As is conventional, a support arm 141 interconnects a harness 142 to be worn by a camera operator and a gimbal 143 for supporting a frame 144 which receives a camera 145 and its associated components, such as a battery pack 146 and monitor 147. The support arm 141 is comprised of two arm sections 148, 149 joined at a hinged connection 150. The arm section 149 includes a tensioning system 151 such as is illustrated in FIGS. 13 and 14, and an adjustment knob 152 (which substitutes for the adjustment screw 131) which permits adjustment of the support arm 141 to the weight (the camera 145, the battery pack 146, the monitor 147, etc.) which it is to support. This can be done without having to change any springs, or the configuration of the frame, permitting simple and straightforward field adjustments when in use.
In this embodiment, as well as in the embodiment of FIG. 2, the support arm is comprised of two arm sections (in the present embodiment, the arm sections 148, 149; in the embodiment of FIG. 2, the arm section including the arm links 2, 4 and the arm section including the arm links 10, 12) connected together so that they may rotate about each other in the horizontal plane. Two improvements are noteworthy here.
First, the foregoing improvements are applicable either to the upper arm section 148, the forearm section 149, or both, as desired. If either of the arm sections is not provided with a tensioning system produced in accordance with the present invention, it may in the alternative be provided with a tensioning system produced in accordance with that shown in U.S. Pat. No. 4,208,028, or may be substituted with a passive link in place of the active section forming the support arm. The support arm 141 shown in FIG. 12 includes an active forearm section 149 and a passive upper arm section 148. It is also possible to provide an active upper arm section 148 and a passive forearm section 149, or an active upper arm section 148 and an active forearm section 149, as desired.
Second, in interconnecting the arm sections of the support arm, a simple hinge was originally provided (see FIG. 2). This allowed the two arm sections to rotate from a position virtually doubled back on each other to a virtually in-line position. It was later decided that it would be desirable to be able to rotate through the in-line position to a position doubled back on the other side, to permit a rotation of 360 degrees.
As is schematically shown in FIG. 15, this is accomplished by adding a link 160 that connects the ends 161, 162 of the two arm sections 163, 164 at their vertical centers. In order to permit the support arm to rotate completely, the length of the link 160 must be slightly greater than the width of the arm sections 163, 164, which causes an increase in the extended length of the support arm. Referring to FIGS. 16 and 17, this increase in extended length is reduced, while still allowing 360 degrees of rotation, by providing hinge pin holes 165 in the end pieces 161, 162 of the arm sections 163, 164, which then receive center leaves 166 for interconnecting the arm sections 163, 164. Either two or three center leaves 166 can be provided, which cross each other. The illustrated embodiment shows a three leaf arrangement. The crossed hinge leaves 166 are provided to prevent the arm sections 163, 164 from stretching apart while eliminating the need for two mounting leaves (as in FIG. 15), thereby reducing the extended length of the support arm.
To be noted is that no springs are used in this device. The use of springs would provide a favored position for the hinge, and prevent sag. However, in the present situation, such a favored position is not desired since it would impede smooth movement between the two arm sections.
It will be understood that various changes in the details, materials and arrangement of parts which have been herein described and illustrated in order to explain the nature of this invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the following claims.
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The support arm of a camera stabilizing device is provided with a tensioning assembly which is mated to the support arm in a fashion which permits continuous adjustment of the geometric relationship between the end points of the tensioning assembly and the remaining structures which comprise the support arm. This can include adjustment of the frame of the support arm, or adjustment of an end point of the tensioning assembly relative to the frame of the support arm using a cable and drum arrangement coupled with a spring of appropriate size and tension.
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RELATED PATENT APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62/207,087 filed Aug. 19, 2015 entitled A BARRICADE DEVICE FOR SCHOOL CLASSROOM DOORS TO PREVENT UNWANTED PERSONS DURING CODE RED which is hereby incorporated herein by reference in the entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to security devices for barring the door of a doorway and, specifically, to a door barricade device for an outwardly swinging door to prevent unauthorized opening of the door.
BACKGROUND OF THE INVENTION
[0003] The security of children within a classroom environment is the most important responsibility of any teacher or faculty member of a school. The present invention provides a useful and efficient device to barricade children safely within a classroom and prevent entry into a classroom by an armed intruder or other unwanted person during an emergency such as a code yellow or code red event. During an attack on a school seconds count and make the difference between survivors and casualties. Many of the security devices of the prior art are heavy and difficult to put into place on a door in the mere seconds it takes to place the door barricade of the present invention, that may be referred to herein as the Van Buren Barricade. In U.S. Pat. No. 7,770,420 to Carr a complicated device having a bar supporting a J-shaped clamping member and a clamping mechanism is disclosed. The door knob of a door is secured by extending the J-shaped clamping member around the door knob and then inserting the end of clamping member through the clamping mechanism and inserting a pad lock through the clamping member to secure the door and prevent the door knob from being turned. The number of parts and complexity of the Carr lockdown door bar device appears difficult to install in an emergency and may be much more expensive than the barricade of the present invention, making it unsuitable for most schools. Other devices such as in U.S. Pat. No. 4,856,831 to Roden Jr. and U.S. Patent Publication No. 2015/0376923 to Presutti require the permanent attachment of fixtures to the door and/or around the door jamb adding installation costs to the costs of the device that many school districts may be unable to afford. The present invention addresses issues of complexity, ease of use and costs providing for the Van Buren Barricade of the present invention to be suitable for any classroom. The Van Buren Barricade is light weight, easily stored, and easily retrieved. It renders the door immovable when put in place in seconds and secures the classroom from outside entry.
SUMMARY OF THE INVENTION
[0004] The present invention provides a method and apparatus to barricade an outward swinging door in an emergency to prevent an unauthorized person from entering. In a preferred embodiment the Van Buren Barricade is made from wood, but metal or other composites such as square tube piping of polyvinyl chloride (PVC) or other similarly resilient materials may be used to manufacture the barricade device. The Van Buren Barricade is therefore lightweight, easy to manufacture and inexpensive enough to have even less affluent schools afford the barricade device for every one of their classrooms, or alternatively make the security devices within their own school wood, plastic, or metal fabrication facilities. Barricades of the prior art that are made of heavy components and that have complex components may be difficult for an older or less agile person to lift and manipulate particularly in a highly stressful emergency situation where people's lives may be at risk. The Van Buren Barricade may be installed on doors having door knobs or door handles and work equally as well to prevent the door from being opened.
[0005] The Van Buren Barricade is easily installed by having a person such as a teacher or other faculty member simply pick up the barricade device from a storage location in the classroom and place it over the door handle to secure the door. The Van Buren Barricade renders the door immovable when put in place in seconds and secures the classroom from outside entry preventing an intruder or other unauthorized person outside of the room from opening the door thereby safely securing the occupants within the room. The present invention differs from the prior art in that there are no barricades that are as simple, as quick to install or as effective as the Van Buren Barricade.
[0006] It is an object and advantage of the present invention to provide a barricade device that is suitable and affordable for any classroom or for other facilities such as hospitals, office buildings, departments of government, entertainment locals and other public buildings concerned with security in an emergency.
[0007] It is an object and advantage of the present invention to provide a barricade device that is easily stored to make it readily accessible in an emergency.
[0008] It is an object and advantage of the present invention to provide a barricade device having no complex parts to manipulate by twisting, inserting, or otherwise adjusting to secure an outward swinging door to prevent the door from being opened.
[0009] It is an object and advantage of the present invention to provide a barricade device that is lightweight and easily handled to put into place on an outward swinging door to prevent the door from being opened.
[0010] It is an object and advantage of the present invention to provide a barricade device that is secured over a door knob or door handle and aligns along the door jamb to prevent the door from being opened.
[0011] It is an object and advantage of the present invention to provide a method of manufacture of a barricade device with limited complexity and using a minimal number of components.
[0012] It is an object and advantage of the present invention to provide to provide a method of manufacture of a barricade device that uses a single board, square tube, or round pipe that is cut to adequate lengths to form the components of the barricade of the present invention.
[0013] It is an object and advantage of the present invention to provide a method of manufacture of a barricade device that uses only bolts to assemble the barricade without any complex mechanisms to secure the barricade to the door.
[0014] The present invention relates to a door barricade comprising a brace; at least one spacer affixed to the brace; a latch affixed to the at least one spacer, the latch having a slot; and wherein the slot of the latch is inserted over a door handle, and the brace is secured against a door jamb to secure a door in a closed position. No further adjustment of the brace, spacers or latch of the door barricade is needed to secure the door in a closed position. The brace, at least one spacer and the latch of the door barricade may be formed from a single piece of board, rod, or tube. The number of spacers used in the door barricade is determined by the offset distance from the surface of the door to the face of the interior casing. The door barricade may further comprise at least one bolt and at least one thumb screw to affix the latch to the spacer and the spacer to the brace. The thumb screw may secure the bolt by hand tightening. The door barricade may comprise two bolt holes aligned through each of the brace, at least one spacer and latch. The two bolt holes may be positioned on either side and above the slot of the latch. The two bolt holes may be at a distance closer to the top of the brace, the top of the at least one spacers and the top of the latch. The latch of the door barricade has tangs that form the slot and an outer surface of one of the tangs is in contact with the interior surface of the door jamb. The brace of the door barricade may have notches.
[0015] The present invention further relates to a door barricade comprising a board that is cut to form a brace, at least one spacer, and a latch having a slot; and wherein the at least one spacer is affixed to the brace, the latch is affixed to the at least one spacer, and the slot of the latch is inserted over a door handle, and the brace is secured against a door jamb to secure a door in a closed position. No further adjustment of the brace, spacers or latch of the door barricade is needed to secure the door in a closed position. The number of spacers for the door barricade is determined by the offset distance from the surface of the door to the face of the interior casing. The door barricade may comprise at least one bolt and at least one thumb screw to affix the latch to the spacer and the spacer to the brace by hand tightening. The door barricade may comprise two bolt holes aligned through each of the brace, at least one spacer and latch; and wherein the two bolt holes are on either side and above the slot of the latch, and at a distance closer to the top of the brace, the top of the at least one spacers and the top of the latch.
[0016] The present invention relates to a method of making a door barricade, comprising cutting a board to form a brace, at least one spacer and latch; forming a slot in the latch; affixing the brace to the at least one spacer, affixing the spacer to the latch, and inserting the door handle of a door into the slot and aligning the brace against a door jamb of the door to prevent the door from being opened. The method of making a door barricade may comprise forming the slot by drilling a hole in the latch; and cutting from a bottom edge of the latch to points on the circumference at the diameter of the hole. The method of making a door barricade may comprise drilling at least one bolt hole through each of the brace, at least one spacer and latch so that the bolt holes are an equal distance from the top and sides of each of the brace, at least one spacer and latch to insert a bolt through the bolt hole and affix the at least one spacer to the brace and the latch to the at least one spacer. The method of making a door barricade, comprising drilling a first bolt hole through each of the brace, at least one spacer and latch so that the bolt holes are an equal distance from the top and a side of each of the brace, at least one spacer and latch to insert a bolt through the bolt hole and affix the at least one spacer to the brace and the latch to the at least one spacer; drilling a second bolt hole through each of the brace, at least one spacer and latch so that the bolt holes are an equal distance from the top and the other side of each of the brace, at least one spacer and latch to insert a bolt through the bolt hole and affix the at least one spacer to the brace and the latch to the at least one spacer. The method of making a door barricade may comprise routing out notches in the brace.
[0017] Other objects and advantages of the present invention will become obvious to the reader and it is intended that these objects and advantages are within the scope of the present invention. To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of this application.
BRIEF DESCRIPTION OF THE INVENTION
[0018] 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:
[0019] FIG. 1 is an exploded view showing the assembly of parts of an embodiment of the Van Buren Barricade of the present invention;
[0020] FIG. 2A is a side view of an embodiment of a brace in an embodiment of the Van Buren Barricade of the present invention;
[0021] FIG. 2B is a front view of an embodiment of a brace in an embodiment of the Van Buren Barricade of the present invention;
[0022] FIG. 2C is a rear view of an embodiment of a brace in an embodiment of the Van Buren Barricade of the present invention;
[0023] FIG. 3A is a side view of an embodiment of a spacer in an embodiment of the Van Buren Barricade of the present invention;
[0024] FIG. 3B is a top view of an embodiment of a spacer in an embodiment of the Van Buren Barricade of the present invention;
[0025] FIG. 3C is a front view of an embodiment of a spacer in an embodiment of the Van Buren Barricade of the present invention;
[0026] FIG. 3D is a perspective view of an embodiment of a spacer in an embodiment of the Van Buren Barricade of the present invention;
[0027] FIG. 4A is a side view of an embodiment of a latch in an embodiment of the Van Buren Barricade of the present invention;
[0028] FIG. 4B is a top view of an embodiment of a latch in an embodiment of the Van Buren Barricade of the present invention;
[0029] FIG. 4C is a front view of an embodiment of a latch in an embodiment of the Van Buren Barricade of the present invention;
[0030] FIG. 4D is a bottom view of an embodiment of a latch in an embodiment of the Van Buren Barricade of the present invention;
[0031] FIG. 4E is a perspective view of an embodiment of a latch in an embodiment of the Van Buren Barricade of the present invention;
[0032] FIG. 5 is a perspective view of an embodiment of the Van Buren Barricade of the present invention prepared for installation on a door;
[0033] FIG. 6 is a detailed view of an embodiment of the Van Buren Barricade of the present invention installed over a door handle;
[0034] FIG. 7 is a perspective view of an embodiment of the Van Buren Barricade of the present invention installed on a door;
[0035] FIG. 8 is a detailed view of an embodiment of the Van Buren Barricade of the present invention installed over a door handle; and
[0036] FIG. 9 is a detailed cross-sectional view along section A-A of FIG. 8 in an embodiment of the Van Buren Barricade of the present invention installed over a door handle.
DETAILED DESCRIPTION OF THE INVENTION
[0037] As shown in FIG. 1 , the Van Buren Barricade 10 comprises a brace 12 , one or more spacers 14 , and a latch 16 . Two carriage bolts 18 or other attachment fixtures, or adhesives secure the latch 16 with one or more spacers 14 to the brace 12 using two butterfly nuts 20 commonly referred to as thumb screws or other fasteners. The Van Buren Barricade 10 is different from the prior art in that the components may be formed from a single board, rod or pipe that is long enough to cut to form the brace 12 , spacers 14 and latch 16 , making the Van Buren Barricade very inexpensive to manufacture. For example, an 8-foot length of a 2″×4″ or 2″×6″ wooden board, or of a ½″ to 1¼″ square metal rod or ¾″ to 1½″ of polyvinyl chloride (PVC) square tube or of any other rigid material with sufficient tensile strength to not deform or break could be used to manufacture the barricade device 10 . As shown in FIGS. 2A-2C , in an embodiment of the Van Buren Barricade 10 , a 2×4 wooden board of a standard size of 8-feet (96″) in length, 2″ in depth D and 4″ in width W could be cut to a length L of approximately 48″ which is 12″ longer than the width of 36″ of a standard door 70 , thereby extending the brace 12 beyond the width of the door 70 at either end. If desired, notches 22 may be formed in the brace 12 . The sidewalls 26 of the notches 22 may be routed to a depth of approximately ¼″ and a width of 2¼″ to be slightly wider than the interior casing 78 of a door jamb 74 as described herein. The outer sidewall 26 of a first notch 22 a is routed at distance of 4″ from the right end 28 of the brace 12 . The outer sidewall 26 of a second notch 22 b is routed at distance of 4″ from the left end 30 of the brace 12 . Two bolt holes 36 each having a ⅝″ diameter are drilled through the brace 12 for attachment of the spacers 14 and latch 16 using carriage bolts 18 . A first bolt hole 36 a is drilled at a distance of ¾″ from a center point of the first bolt hole 36 a to the sidewall 26 of one of the notches 22 , 1¼″ from the top 38 of the brace 12 , and 2¾″ from the bottom 40 of the brace 12 . As shown in a rear view of the brace 12 in FIG. C, the center of the first bolt hole 36 a is therefore 7″ from the right end 28 of the brace 12 . A second bolt hole 36 b is drilled 2½″ from the center of the first bolt hole 36 a at a similar distance of 1¼″ from the top 38 and 2¾″ from the bottom 40 of the brace 12 .
[0038] One or more spacers 14 are cut to a length Ls of 4½″ from the remaining portion of the wooden board. The spacer 14 therefore has the same depth Ds of 2″ and width Ws of 4″ as shown in FIGS. 3A-3C . Two bolt holes 42 , each having a ⅝″ diameter, are drilled through the spacer 14 . A first bolt hole 42 a is drilled at a distance of 1¼″ from the top 44 of the spacer 14 and ¾″ from the right side 46 to a center point of the bolt hole 42 a leaving a distance of 3¼″ from the bottom 48 of the spacer 14 to the center point of the first bolt hole 42 a . A second bolt hole 42 b is drilled at a distance of 1¼″ from the top 44 of the spacer 14 and ¾″ from the left side 50 to a center point of the bolt hole 42 b also leaving a distance of 3¼″ from the bottom 48 of the spacer 14 . The distance between the center points of the bolt holes 42 is therefore 2½″. A perspective view of the spacer 14 is shown in FIG. 3D .
[0039] As shown in FIGS. 4A-4D , the latch 16 is cut from the remainder of the wooden board to a length L L of 11″. The latch 16 therefore has the same depth D L of 2″ and width W L of 4″. Two bolt holes 52 , each having a ⅝″ diameter, are drilled through the latch 16 . A first bolt hole 52 a is drilled at a distance of 1¼″ from the top 54 of the latch 16 and ¾″ from the right side 56 to a center point of the bolt hole 52 a leaving a distance of 9¾″ from the bottom 58 of the latch 16 to the center point of the first bolt hole 52 a . A second bolt hole 52 b is drilled at a distance of 1¼″ from the top 54 of the latch 16 and ¾″ from the left side 60 to a center point of the bolt hole 52 b also leaving a distance of 9¾″ from the bottom 58 of the latch 16 .
[0040] A slot S is formed in the latch 16 by drilling a 1″ diameter hole 62 at a distance to the center point of the hole 62 of 6½″ from the bottom 58 and 2″ from the right side 56 and the left side 60 of the latch 16 . The slot S is cut out by cutting from the bottom 58 at a distance of 1½″ from the right side 56 to a point 64 along the circumference of the drilled hole 62 and from a distance of 1½″ from the left side 60 to a point 66 to form a uniform 1″ diameter slot S having a semicircular upper portion formed from the 1″ diameter hole 62 . As shown in FIG. 4E , the slot S is formed between two extensions or tangs 68 that will latch around a door knob or door handle. The inner surfaces 70 of the tangs 68 may be sanded or painted to have the latch 16 easily slide around the stem or shank of a door knob or door handle. The outer surface 61 of the left side 56 or right side 60 of the tangs 68 may be sufficiently smooth to align with and make contact along an interior surface 82 of the door jamb 74 as described herein.
[0041] In this embodiment, the bolt holes 28 can accommodate the carriage bolts 18 that are 8″ in length and have a diameter of ⅜″. To assemble the Van Buren Barricade 10 , a carriage bolt 18 is inserted through the first bolt hole 52 a in the latch 16 , through the first bolt hole 42 a in the spacer and the first bolt hole 36 a in the brace 12 . A butterfly nut 20 or other fastener is tightened onto the carriage bolt 18 . By using a butterfly nut 20 , the wings 21 may be hand tightened making the Van Buren Barricade 10 easy to assembly. A second carriage bolt 18 is inserted through the second bolt hole 52 b in the latch 16 , through the second bolt hole 42 b in the spacer and through the second bolt hole 36 b in the brace 12 . By using two carriage bolts 18 and having a distance of 2½″ between the bolt holes, stresses are distributed across the face of the latch 16 and spacers 14 preventing splintering of a Van Buren Barricade 10 made of wood or deformation if a plastic or other composite material is used.
[0042] Once assembled as shown in FIG. 5 , the Van Buren Barricade 10 may be installed to a door 70 by aligning the latch 16 over a door handle 72 with the notches 22 of the brace 12 mating with the door jamb 74 . The Van Buren Barricade 10 when installed may partially cover a door lock 76 and prevent the insertion of a key or any other item through a key hole. The door jamb 74 has an interior casing 78 , two side jambs 80 and a head jamb (not shown). Each side jamb 80 has an interior surface 82 that the right side 56 of the latch 16 may come in contact with and be slid along as the slot S of the latch 16 is inserted over and around the door handle 72 , as shown in FIG. 6 . In other embodiments of the Van Buren Barricade 10 , the spacers 14 and latch 16 may be installed on the opposite end of the brace 12 to accommodate doors 70 that have the door handle 72 on the right side of the door instead of the left.
[0043] The Van Buren Barricade 10 is light weight and easy to maneuver with the spacers 14 providing the proper offset distance from the surface of the door 70 and the face 84 of the interior casing 78 . Any number of spacers 14 or no spacers may be used. Preferably by stacking the spacers 14 , the spacers 14 may be formed from the same board, rod, or pipe that the brace 12 and latch 16 are formed from, thereby keeping the costs to manufacture the Van Buren Barricade 10 at a minimum. The notches 22 , while not necessary, prevent lateral movement of the Van Buren Barricade 10 by having the sidewalls 26 of each notch 22 wrap around the edges 86 of the interior casing 78 . Once in place, the tangs 68 of the latch 16 extend a sufficient distance beyond stem 88 of the door handle 72 so that no additional adjustments or tightening of fasteners such as the thumb screws or butterfly nuts 20 of the Van Buren Barricade 10 are needed to secure the door 70 and prevent the door 70 from being pulled from the outside and opened. The extended length of the inner tang 68 a and outer tang 68 b and narrow slot S is dimensioned for a close-fit around the stem 88 to prevent the door handle 72 or door knob from being turned and pulled or aligned with and pulled through the slot S. Embodiments of the Van Buren Barricade 10 are also formed from adequate dimensions to provide for the inner tang 68 a to be wedged between the stem 88 and the side jamb 80 providing a tight fit and bracing the latch 16 against interior surface 82 of the side jamb 80 for more support and providing an indication to the teacher, faculty member or other installer that the Van Buren Barricade 10 is securely in place.
[0044] The ends 28 and 30 of the brace 12 of the Van Buren Barricade 10 once installed, extend out beyond the width of a door jamb 74 and in this embodiment, three spacers 14 provide the offset distance O from the surface of the door 70 to secure each end 28 and 30 of the brace 12 against the interior casing 70 , as shown in FIG. 7 . The offset distance O set by the width of the side jamb 80 and the depth of the interior casing 78 may not be of a standard size, so any number of spacers 14 may be cut and used to accommodate various door jamb sizes. The dimensions given in this embodiment are all approximate dimensions suitable for a standard door having a width of 36″. However, while not all doors may be of a standard size, the backset or distance from the edge 90 of the door 70 that aligns along the exterior casing of the door jamb 74 to the center C of the bore hole for the door handle 72 , as shown in FIG. 8 , has standard sizes of 2⅜″ or 2¼″ for residential doors in the United States. The depth D of the side jamb 80 or door stop is also commonly in standard sizes of ⅜″ or ⅝″ therefore the latch 16 of the Van Buren Barricade 10 will fit securely around and over most door knobs or door handles and align along the interior surface 82 of the side jamb 80 . In preferred embodiments, the outer surface 61 of the right side 56 or left side 60 in alternative embodiments will abut the interior surface 82 of the side jamb 80 creating a somewhat frictional fit and locking the Van Buren Barricade 10 in place. The contacting of the side 56 or 60 of the latch 16 with the side jamb 80 may provide some additional structural support, however even if a small space is provided between the latch 16 and side jamb 80 , the Van Buren Barricade 10 will securely hold and prevent the door 70 from being opened even when the exterior door handle is strongly pulled.
[0045] As shown in cross-section in FIG. 9 along section A-A of FIG. 8 , the door jamb 74 has an exterior casing 92 that the edge 90 of the door aligns against when the door 70 is closed. The interior surface 94 of the door 70 abuts against the exterior surface 96 of the side jamb 80 which with the outer casing 78 may, particularly in metal door jambs, have the door jamb 74 be formed in a single piece of material. In this cross-sectional view, the latch 16 abuts along the interior surface 82 of the side jamb 80 and the spacers 14 set the offset distance O so that the latch 16 extends over the stem 88 and behind the door handle 72 . The carriage bolts 18 extend through the latch 16 , spacers 14 and brace 12 and are tightened using the wings 21 of the butterfly nuts 20 to provide for hand-tightening of the Van Buren Barricade assembly 10 . Once tightened, the Van Buren Barricade 10 unlike the barricades of the prior art requires no further adjustment, but instead is simply installed over the door handle 72 and will hold the door securely shut. While an embodiment with specific dimensions has been described, other suitable dimensions for the brace 12 , spacers 14 , latch 16 and bolts or other attachment fixtures for doors and door jambs of different sizes are within the scope of the present invention. In other embodiments, the Van Buren Barricade 10 may be formed by cutting a square or rectangular shaped metal rod, PVC tube or other sufficiently resilient material to form the brace 12 , one or more spacers 14 and the latch 16 and by cutting a slot S in the latch 16 . The number of spacers 14 needed is determined by the dimensions of the board, rod or tube chosen and the offset distance O from the surface of the door 70 to the face 84 of the interior casing 78 . In some embodiments, a spacer 14 may not be needed and the Van Buren Barricade 10 is formed from only the brace 12 and latch 16 .
[0046] An embodiment of the Van Buren Barricade as described herein includes:
[0047] 1. Two—8 inches long by ⅜-inch carriage bolts
[0048] 2. Two—⅜-inch butterfly nuts
[0049] 3. One—48 inches long, 2 inches deep and 4 inches wide brace with notches formed by routing sections of 2¼″ inches wide×¼″ inch deep
[0050] 4. Three—4½″ inches long 2 inches deep and 4 inches wide spacers
[0051] 5. One—11 inches long 2 inches deep and 4 inches wide latch with a 1-inch slot cut 6.5 inches from the end terminating in a 1-inch diameter hole
[0052] Relationship Between the Components:
[0053] All of the components come together to form one structure which is held together by the 8 inches long carriage bolts 18 . The Van Buren Barricade 10 is light weight (approximately 5 pounds) and easily carried by any adult or child. It takes about 2 to 3 seconds to slip over the door handle and secure the door. It is designed for doors which open outward for example into a corridor from a classroom.
[0054] How the Invention Works:
[0055] In a panic situation for example as has happened in schools around the United States there is little time to respond. The Van Buren Barricade 10 would be stored in a location inside the classroom which the teacher has quick access to, and upon need, would be easily retrieved. The Van Buren Barricade 10 would then be carried to the door 70 and slipped over the door handle 72 with both ends 28 and 30 locked on to the interior casing 78 of the door jamb 74 . The tangs 68 of the latch 16 extend over and around the door handle 72 and the notches 22 wrap around the interior casing 78 , taking only seconds to fully install the Van Buren Barricade 10 and secure the door 70 . The Van Buren Barricade 10 requires no further adjustment to secure the door 70 in a closed position, however if necessary the thumb screws or butterfly nuts 20 could be tightened but once assembled retightening of the Van Buren Barricade 10 would in most cases not be necessary. The teacher and students could then take cover away from the door until police arrive. During an exercise at Hudson High School an early prototype of this device was demonstrated to the Hudson Police department who favorably noted its use.
[0056] How to Make the Invention:
[0057] The device was built by the inventor using only a table saw & electric drill. Since all elements necessary to build the device are available at any lumber yard such as a 2×4 board, bolts, and nuts, anyone can build this device easily and inexpensively, an important concern in less affluent school districts having many classrooms that each would require the Van Buren Barricade 10 . The Van Buren Barricade 10 may optionally be painted or otherwise treated to provide smooth surfaces and an appropriate appearance. The components for this very simple device when assembled as shown operate as planned and perform the function of securing an outward swinging door.
[0058] How to Use the Invention:
[0059] As an example, when a code red is announced at a school, or other similar emergency, the teacher would immediately respond by retrieving the Van Buren Barricade 10 from its stored location. He or she would then slide the Van Buren Barricade 10 over the door handle 72 and align the notches 22 of the brace 12 to interlock with the interior casing 78 of the door jamb 74 . If necessary, the two butterfly nuts 20 could be tightened. Once that is done the door 70 is secure. Students and teacher would then take cover until police arrive. An important feature of this device is speed. Most horrible casualties happen within minutes of the beginning of a code red at schools. The installation of this device in seconds protects students and teachers quickly from a perpetrator entering their classroom. Additionally, the Van Buren Barricade 10 need not only be used in school classrooms. It could be used in any setting where security is needed to prevent access by unwanted persons.
[0060] Although specific embodiments of the invention have been disclosed herein in detail, it is to be understood that this is for purposes of illustration. This disclosure is not to be construed as limiting the scope of the invention, since the described embodiments may be changed in details as will become apparent to those skilled in the art in order to adapt the barricade to particular applications, without departing from the scope of the following claims and equivalents of the claimed elements.
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A security device for barring the door of a doorway and, specifically, to a door barricade device for an outwardly swinging door to prevent unauthorized opening of the door.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to male undergarments, and, more particularly, to an undergarment brief or shorts having a double fly construction.
BACKGROUND OF THE INVENTION
[0002] Various forms of male undergarments have been developed over the ages. In particular, in more modern times, two types have become most widely known: underwear briefs, sometimes referred to as “jockey shorts,” and a loosely fitting shorts known as “boxers.”
[0003] Men's briefs are generally constructed with one or more trunk panels, and overlapping front panels. The overlapping front panels typically define a singular fly opening for access through the outermost panel to the penis for purposes of urination. Many attempts have been made to solve the numerous problems associated with the known brief constructions, such as discomfort, lack of support, and embarrassment due to unsightly bulging or slippage of the male genital organs. As a result, pouches and sacks, cages, and girdles have be incorporated into briefs toward the end of an optimal undergarment construction. Male undergarment construction has also focused on snug-fit and fly arrangements that prevent the male genitalia from falling therethrough.
[0004] The briefs known in the art have commonly been constructed with a single, right-handed fly, the fly being formed by the front panel or panels. Where inner and outer panels are used, each panel has a concave portion formed therealong one side edge, and the two panels are placed one upon the other so that the concave portion on the outer front panel is on the opposite side from the concave portion of the inner front panel. This particular construction has created a tortuous path for gaining access to the penis. Single fly constructions provide relatively convenient access for right-handed persons. Some persons, particularly left-handed persons and/or handicapped persons, require or prefer a left-handed fly. One prior art attempt at solving this problem was implemented in connection with a boxer shorts construction with a centrally-located, vertical, single front fly. A wide vent backing panel on the inside of the shorts is attached at the top and bottom and unattached on both sides. For the wearer, once the vertical front fly has been entered, either a left or right inner opening is available. While such a construction is plausible with loosely fitting boxer shorts, it would not be practical with a man's brief due to its closely/snugly fitting construction.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a man's underwear construction that addresses the problems associated with the prior art. As used herein, the term “underwear” is intended to encompass shorts, drawers, skivvies, jockey shorts, boxer shorts, briefs, long underwear, and variations thereof. In a first preferred embodiment of the present invention, the underwear construction includes a trunk panel, and inner and outer panels that are joined together along a plurality of edges, or seams, resulting in a double fly.
[0006] The panels forming the underwear of the present invention are desirably of knitted fabric, however the invention is not limited to fabric of a knitted construction. Nevertheless, the knitted fabric of the preferred embodiment is formed from yarns of 100% or less cotton; the fabric also could well be knitted or woven from blended natural and synthetic yarns.
[0007] In the first embodiment, the trunk panel is the largest single panel forming the underwear and has an upper edge, lower edge, and opposed side edges. The opposed side edges have concave cutouts formed therealong that terminate at the bottom edge. The concave portions, when attached to front panels, define leg openings.
[0008] The present invention uses two uniquely formed front panels. The inner panel has top and bottom edges and opposed side edges, where the bottom edge is joined to the lower edge of the trunk panel and the opposed side edges are joined along their uppermost portions to the opposed side edges of the trunk panel. The top edge of the inner panel does not extend to the top of the outer panel and is unattached so that an opening is formed between the inner and outer panels. The outer front panel overlies the inner front panel and is joined to the lower edge of the trunk panel and to the upper portions of the opposed side edges of the trunk panel. Each of the opposed side edges of the outer front panel are unjoined along at least some portion to form a fly on each of the opposed side edges. A wearer of the underwear so formed can access either fly.
[0009] These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment when considered with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a front view of the men's underwear brief of the present invention;
[0011] [0011]FIG. 2 is an plan view illustrating the panels that form the brief of FIG. 1;
[0012] [0012]FIG. 3 is a front view of the inner and outer panel construction of the present invention;
[0013] [0013]FIG. 4 is a front view of the men's boxer shorts of the present invention; and
[0014] [0014]FIG. 5 is an plan view illustrating the panels that form the boxer shorts of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Referring now to FIGS. 1 and 2, it will be understood that the illustrations are for the purpose of describing a preferred embodiment of the invention and are not intended to limit the invention thereto. FIG. 1 is a front schematic view of a pair of men's underwear briefs according to the present invention, shown generally as 10 . In one embodiment, the briefs are shaped in conventional fashion for “jockey” type briefs, although the invention is not limited to a brief construction. As best illustrated in FIG. 2, in the preferred embodiment, the briefs 10 are formed from three panels that are joined together along specified seams. The panels are each formed from a single knitted fabric of yarns that are 100 percent cotton; however, the fabric forming the panels are not limited to a 100 percent cotton structure, and are not limited to knitted fabric.
[0016] [0016]FIG. 2 best illustrates the shapes of the three panels used to form the briefs before they are joined together. As those skilled in the art will appreciate, the sequence of joining the panels is not critical and the description which follows regarding joinder along seams should not be construed as a required sequence. Likewise, the number of panels is not critical so long as the front panel includes two flies. Generally, the panels are aligned and a binding is sewn over the panel junctures to securely join the edges of the panels together and to create an aesthetically acceptable appearance and comfortable feel. As used herein, the term “binding” refers to a strip of like material that is placed over the juncture of adjoining panels or along the exposed unfinished edges of a panel.
[0017] Referring now to FIG. 2, the construction of the briefs 10 will be described in detail. Trunk panel 12 covers the trunk, or buttocks, of the wearer of the brief and extends around the waist to the front of the briefs. Trunk panel 12 , inner panel 16 , and outer panel 14 are sewn together along their bottom edges 12 c , 14 c , and 16 c to form a lower seam. Trunk panel 12 wraps around the front of the briefs for attachment to inner panel 16 . Specifically, edges 12 a and 12 d of trunk panel 12 are attached to edges 16 a and 16 d , respectively, of inner panel 16 . Similarly, edges 12 b and 12 e of trunk panel 12 are attached to edges 16 b and 16 e , respectively, of inner panel 16 . As will be understood, the attachment of edges 12 d to 16 d and 12 e to 16 e also create leg openings 23 a , 23 b for the briefs as shown in FIG. 1.
[0018] Returning to FIG. 2, trunk panel 12 is joined to outer panel 14 so that outer panel 14 overlies inner panel 16 . The overlying front panel construction is best seen in FIG. 3. Returning to FIG. 2, inner panel 16 is attached along its lower edge 16 c to the bottom edge 12 c of trunk panel 12 , as described above. Likewise, outer panel 14 is attached along its lower edge 14 c to bottom edge 12 c of trunk panel 12 . Alternatively, edge 16 c of inner panel 16 may not extend completely down to to edge 12 c and may be left unjoined so that a lower opening between outer panel 14 and inner panel 16 is formed therebetween. Edges 14 a and 14 b of outer panel 14 are attached to edges 16 a and 16 b , respectively, of inner panel 16 , and outer edges 14 aa and 14 bb of outer panel 14 are attached to the lower portions of edges 16 d and 16 e, respectively, of inner panel 16 , so that the outer panel 14 and inner panel 16 are securely overlapping.
[0019] As can be seen in FIGS. 1 and 3, outer panel 14 has cutout portions 24 and 25 , which when the outer and inner panels are securely overlapped, form opposing flies on either side of outer panel 14 for openings between the outer and inner panels. Preferably, inner panel 16 is shorter than outer panel 14 , so that, when overlapping, upper edge 16 f does not extend to the top of the briefs as does edge 14 f of outer panel 14 , and is not joined to outer panel 14 . This creates an opening 22 between the outer and inner panels for upper access to the penis. While edges 16 f and 16 c ′ are shown as horizontally configured openings between the inner and outer panels, they are not limited thereto. Similarly, the opposing flies 25 a, 25 b may be positioned higher or lower on the briefs and do not necessarily have to be aligned at the same height on the front panels.
[0020] Returning to FIG. 1, a waistband 32 of elastic fabric is sewn around the upper periphery of the briefs to aid in holding the briefs in proper alignment about the torso. Additionally, bindings 34 and 35 , and 28 and 29 , are secured over the seams between the trunk panel 12 and the inner and outer panels 14 , 16 , as well as around the leg openings.
[0021] A second embodiment of the present invention provides a men's underwear formed as boxer shorts, shown generally as 40 in FIG. 4, also with a double fly. The overlying arrangement of the inner panel 46 and the outer panel 44 is the same as that of the briefs 10 , with opposed flies and at least one opening formed by the unattached upper 46 f or lower edges 46 c ′ of inner panel 46 . The principal differences between the construction of the briefs and the construction of the boxer shorts are the number and shape of panels and the joinder or attachment thereof.
[0022] Referring to FIGS. 4 and 5, it can be seen that the boxer shorts 40 are formed from five panels, consisting of four different shapes. There are two leg panels 42 that are identically formed to form the left and right leg portions of the boxer shorts 40 . A can be seen in FIG. 5, and as will be readily understood by those skilled in the art, the trunk portion of the boxer shorts 40 is formed by a rear panel 43 that is joined along edge 43 a to an edge 42 d of one leg portion and along edge 43 b to an edge 42 e on the opposed leg portion. Edges 42 a and 42 b on each leg portion 42 are joined together to complete the leg construction.
[0023] Bottom edges 46 c of inner panel 46 , bottom edge 44 c of outer panel 44 , and edge 43 c of the rear panel 43 are joined together to form the bottom seam of the boxer shorts seat portion. Edge 46 a of inner panel 46 is joined to edge 42 d on one leg portion and edge 46 b of inner panel 46 is joined to edge 42 e on the opposed leg portion. Similarly, edges 44 a and 44 aa of the outer panel 44 are attached along the upper and lower portions of edge 42 d on one leg portion and edges 44 b and 44 bb are joined along the upper and lower portions of edge 42 e on the opposed leg portion.
[0024] Cutouts 44 d and 44 e are unjoined so as to form opposed fly openings between the outer panel 44 and inner panel 46 . Similar to the first embodiment, edge 46 f of inner panel 46 is unjoined, creating and inner opening between inner panel 46 and outer panel 44 . As in the first embodiment, the bottom edge of inner panel 46 need not extend downward for joinder at the bottom seam. A shorter inner panel may terminate at a lower edge 46 c ′ to create a second inner opening between inner panel 46 and outer panel 44 .
[0025] Referring again to FIG. 4, bindings 57 and 58 may be applied along edges 42 c (FIG. 5) of each leg opening bottom. Similarly, bindings 54 , 55 , 56 and 57 may be attached along fly openings edges 44 d and 44 e and the seams between the edges joining the inner, outer, leg, and rear portions of briefs 40 . An elastic waistband 52 is desirably also attached around the upper periphery of the boxer shorts.
[0026] Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims.
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An underwear construction having a trunk panel, an inner panel with an open edge for providing access through said inner panel, an outer panel having openings along opposed side edges, the outer panel overlying the inner panel, wherein the trunk panel, inner panel, and outer panel are joined to provide a wearer of said underwear selective unencumbered access to the penis through either of the openings in said outer panel and through the open edge of said inner panel.
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This is a continuation of application Ser. No. 617,959 filed Sept. 29, 1975, now abandoned.
BACKGROUND OF THIS INVENTION
This invention relates to earth boring drill bits and, more particularly, to an earth boring drill bit having a solid head shank portion and a surrounding, free rotating, burr portion. The present invention is designed for use with a rotary drilling apparatus, and is particularly suited to a rotary drilling apparatus utilizing percussion.
BRIEF DESCRIPTION OF THE PRIOR ART
In the early years of rotary drilling, the solid head bit was the typical bit used for cutting the earth formations. As the diameter of the hole to be drilled increased, the distance traveled by the outer edge of the solid head bit per revolution was equal to the diameter of the bit times π. Therefore, if a large diameter hole was being drilled, the outer edges of the bit would wear out before any appreciable wear would occur to the center portion of the bit. When percussion drilling was combined with rotary drilling, it was found that the drag characteristics on the solid head bit were much more damaging than the impact of the percussion tool. By use of hardened inserts in the solid heat bit, the percussion did not produce anywhere near the wear on the bit as did the drag.
The roller cone bit commonly used today reduces the problem of dragging the cutting edges across the formation and greatly increases the wear area of the bit. As the cones rotate with the rotation of the bit, a much greater surface area is exposed to the outwardly located cutting edges of the bit. A roller cone bit requires bearings and seals which are relatively fragile. A roller cone bit cannot take full advantage of the drilling rate increases available through percussion drilling because a roller cone bit cannot withstand high impact forces on the bearing and seal areas. Roller cone bits normally use a very high downweight and a rapid rotation to drill through the earth's formations.
Both the solid head and the roller cone bits use a stream of fluid delivered through drill pipe and the bit to remove the cuttings. The fluid entraps the cuttings and removes them by raising the cuttings up through the annulus of the hole with the drilling fluid. This prevents extra wear caused by regrinding of the cuttings. It is universally accepted that higher drilling fluid flow rates, including jets directing the fluid towards the bottom of the hole, improves chip clearing efficiency and adds significantly to the drilling rate.
Bennett (U.S. Pat. No. 3,429,390) shows a solid head bit connected off-center to the main string of drilling pipe to produce a wobbling effect while drilling through the earth's formations. However, in Bennett the hardened inserts around the outer edge of the bit are exposed to considerable wear due to drag.
Zublin (U.S. Pat. No. 2,025,260) shows another off-center cutter type bit for drilling through the earth's formations. In Zublin a cutter is located on an off-center shank, but the shank does not extend through the cutter. The cutter portion is free to rotate on the shank.
Stokes (U.S. Pat. No. 2,634,956) shows a boring apparatus having a drill pipe extending through the drilling bit. Again, the outer edges of the cutters would wear much faster than the inside cutters due to drag.
The solid head bits dominate the market for percussion drilling, especially when used for blast holes and water wells which usually do not require closely controlled hole gauge. Solid head bits can handle any formation encountered, plus there is relatively low cost per foot of hole drilled and moderate to high penetration rate. Roller cone bits are almost always used if any of the following conditions are encountered; (1) any fluid other than air is used for clearing the chips, (2) the hole being drilled is deeper than several hundred feet or (3) the hole size is 8 inches in diameter or larger. Since one of the foregoing requirements occurs in practically all oil and gas drilling, almost 100% of the bits used in the petroleum industry are of the roller cone type.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a bit that may be used in conjunction with percussion drilling without the disadvantages of the solid head bits or roller cone bits.
It is even another object of the present invention to provide a bit having reduced wear characteristics when drilling a large diameter hole, while simultaneously being suited for percussion drilling through hard formations.
It is another object of the present invention to provide an offset shank that extends through a burr portion to feed drilling fluid to the bottom of the hole being drilled. Hardened inserts on the end of the shank and the burr impact and cut through the earth formations.
It is yet another object of the present invention to provide a knobby type bit with a burr portion rotatably mounted on an offset shank. Spirals on the burr have hardened inserts to impact and cut through the earth's formations.
The knobby bit forming the present invention has a fluid flow passage extending down and out an offset shank portion to which a spiraled burr is attached. Around the flow passages at the bottom of the shank are located hardened inserts. Hardened inserts are also located on the raised spirals of the burr. As the bit turns due to rotation of the drilling pipe, the offset shank causes the bit to burrow into the formation. The raised spirals on the burr are arranged to oppose the direction of rotation of the burr to prevent "rifling" of the hole. Fluid being discharged in the bottom of the hole will clear the cuttings from around the bit and raise them up the annulus of the hole. Due to the burrowing effect of the bit and the center shank portion, none of the hardened inserts will be subject to very much drag which causes excessive wear. By using an impacting device above the bit, the hardened inserts will very readily break and chip away very hard earth formations. A very broad shoulder area is provided with lubrication to prevent excessive wear between the burr and the shank.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a lower perspective view of the preferred embodiment of the knobby bit.
FIG. 2 is a bottom view of FIG. 1.
FIG. 3 is a cross sectional view of FIG. 2 along section lines 3--3.
FIG. 4 is a partial sectional view of a first alternative embodiment of FIG. 1.
FIG. 5 is a partial sectional view of a second alternative embodiment of FIG. 1.
FIG. 6 is a bottom view of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1, 2 and 3 in combination, there is shown a combined anvil-bit represented generally by the reference numeral 10. The upper portion is a typical anvil 12 used in percussion drilling and the lower portion being the unique knobby bit 14 embodying the present invention. The anvil 12 is described in more detail in U.S. Pat. No. 3,970,152 issued on July 20, 1976. The anvil 12 consists of a flow passage 16 that communicates from the impact surface 18 to the slanting passage 20. The upper portion of the anvil 12 has a seal area 22 for forming a sliding seal with a casing (not shown) in which the combined anvil-bit 10 is carried. Anvil 12 also has splines 24 for a typical spline connection with the casing (not shown). A second seal area 26 slideably seals between the combined anvil-bit 10 and a lower sub (not shown).
For applying a steady downward pressure on the bit 14, shoulder 28 of collar 34 abuts the bottom of the lower sub. Below the collar 34 is located a shank 30 that is offset from the center line of the anvil 12 by an angle "b". The slanting passage 20 is parallel to the center line of shank 30. The upper portion of shank 30 terminates into shoulder 32 which forms the lower portion of collar 34. Spaced downward along the center line of shank 30 from shoulder 32 is a weight bearing shoulder 36. At the bottom of shank 30 is an opening 38 for slanting passage 20. Also located at the bottom of shank 30 are hardened inserts 40 for impacting and cutting the earth's formations through which knobby bit 14 may be drilling. The hardened inserts 40 are typically made from tungsten carbide alloys.
Circumscribing the shank 30 is located a burr 42 that is free to rotate while drilling. The lower end of shank 30 extends through an opening 44 of burr 42. In assembling, the burr 42 simply slides over shank 30 with ball bearings 46 being inserted in opposing shank groove 48 and burr groove 50 through openings 52 in the burr. Opening 52 in the burr is then closed by any suitable means such as a set screw 54. The set screw 54 may be spot welded or held in by a pin to insure it will not come out.
A chamber 56 is provided in shank 30 with a small cross passage 58 connecting from the upper portion of chamber 56 to slanting passage 20. In actual manufacturing of the combined anvil-bit 10, chamber 56 will be drilled from the bottom with cross passage 58 being drilled from the side. Therefore, a suitable plug 60 should be used to close one end of cross passage 58. Inside of chamber 56 is located a piston 62. Below piston 62 is located a passage 64 which connects chamber 56 to the side of the combined anvil-bit 10. By removing set screw 66 from passage 64, it is possible to bleed air and completely charge chamber 56 with lubricant introduced through opening 52.
While drilling with the combined anvil-bit 10, a high pressure fluid will flow through flow passage 16 and slanting passage 20 with a portion of that high pressure fluid feeding through cross passage 58 to piston 62. This will force piston 62 against the oil in chamber 56 thereby maintaining a small pressure on the piston 62, which in turn maintains a small differential pressure on the seals 76 and 78. By slightly reaming a surface 70, a good flow of the lubricant from chamber 56 is provided to opening 44. To insure that the ball bearing 46 receives sufficient lubricant from chamber 56, a slight undercut 72 is provided in weight bearing shoulder, along with bevel 74, to allow the lubricant to reach ball bearing 46. To keep the lubricant between the burr 42 and shank 30, a seal 76 is located at the upper portion of the concentric mating surfaces and a seal 78 is located at the lower portion of the concentric mating surfaces. To protect seals 76 and 78, wipers 80 and 82 are located between seals 76 and 78, respectively, and the outside of the combined anvil-bit 10.
Extending from the bottom of burr 42 are located upwardly extending spirals 84. Between the spirals 84 are located grooves 86 through which the cuttings from the earth's formations may pass. In the spirals are located a series of hardened inserts 88 for impacting and cutting the earth's formations.
The burr 42, which is generally hemipherical in shape with opening 44 therethrough, has its center at the intersection of the center line for the anvil 12 and the center line for shank 30. The angle "b" between these two center lines should be a fairly small angle (approximately 8°). The applicant has found that the angle "b" can be varied between a range of 5° to 15° and still maintain the drillng effectiveness of the present invention. As the combined anvil-bit 10 turns during normal rotary drilling, the burr 42 will rotate in the direction opposite the direction of rotation of the anvil. To prevent "rifling" of the hole being drilled the spirals 84 are so spiralled that they oppose the burr 42 screwing itself into the formation. Rotation of the burr 42 opposite to the direction of rotation of the anvil 12 is caused from the high external friction on the lowermost corner of the burr 42. Of course, the rate of rotation of the burr will vary depending upon the friction and the formation being drilled; however, it is expected that the burr 42 will rotate at about 1/20th that of the anvil 12, but in the opposite direction. With the previously mentioned direction of spiral, the hardened inserts 82 will always cross the formations left by the leading inserts thereby preventing "rifling".
METHOD OF OPERATION
During normal drilling operations, a high pressure fluid will be flowing through flow passage 16 and slanting passage 20 before ejecting through opening 38 to remove the cuttings away from the knobby bit 14. The fluid will flow upward around and over the hardened inserts 40 and 88 to remove the cuttings at the maximum possible rate. The cuttings will be raised in the annulus of the hole by the flow of the drilling fluid. As the knobby bit 14 turns, the end of shank 30 operates in the same manner as a solid head bit with the hardened inserts 40 impacting and cutting the earth's formations. The pressurized fluid ejected through opening 38 immediately removes the cuttings therefrom.
The hardened inserts 40a and 40b which are located on the outer edges of the bottom of shank 30 rotate around a circular path. The circular path covered by the hardened inserts 40a and 40b overlap the area where the lowermost point of the shank 30 and the burr 42 come together. This overlapping by the hardened inserts 40a and 40b helps protect seal 78 from damage by the cuttings. As the shank 30 rotates, the burr 42 also impacts against the side and outer edges of the hole being drilled. However, because the burr 42 is free to rotate, the hardened inserts 88 are not subject to the drag previously experienced by solid head bits. Since the rotation of the burr 42 is much slower than the rotation of shank 30 the outermost inserts 88a and 88b will not be subject to the same amount of drag as the outermost inserts of a typical solid head bit. In fact, the knobby bit 14 tends to burrow itself into the formation with the inserts 40 on the end of shank 30 being used to fracture any hard formations.
Because the weight bearing shoulders 36 and 68 are properly lubricated and have sufficient strength by increased shoulder area over previous roller cone bits, very little wear will occur between the burr 42 and the shank 30. On prior tri-cone (roller cone) type bits, there was a tremendous problem with shank wear and damage when drilling with percussion devices. Almost no appreciable stress is felt on ball bearing 46 which is used to hold the burr 42 on shank 30. As the burr 42 turns on shank 30 lubricant from chamber 56 will be constantly applied to the mating surfaces of the shank 30 and burr 42 to prevent excessive wear. The seals 76 and 78 will keep the lubricant from leaking from the knobby bit 14. Periodically, additional lubricant may have to be added to chamber 56 by removing set screw 54 and replenishing the lubricant.
When drilling in soft formations the cuttings will be gouged up through grooves 86 of spirals 84. However, the rotating action which causes the burr 42 to rock back and forth will clear any portion of the cuttings from the hole and prevent rifling.
FIRST ALTERNATIVE EMBODIMENT
Referring now to FIG. 4 there is shown an alternative embodiment in a partial sectional view wherein the shank 30 extends considerably below the burr 42. A bottom portion 90 of shank 30 is located along the center line of anvil 12 to drill a pilot hole for the remaining portion of the knobby bit. A shoulder 91 is formed by the portion of shank 30 that terminates at the bottom of the burr 42. The hardened inserts 40 fracture the formation with additional inserts 40c clearing the area around the pilot hole. The hardened insert 40c protects the seal 78 from damage by the cuttings. The hardened inserts 88c of the burr 42 overlaps the area to which the seal 78 may be exposed to cuttings thereby further insuring against damage to the seal 78. The remaining portions of the combined anvil bit 10 operate in the same manner as the preferred embodiment shown in FIGS. 1-3.
SECOND ALTERNATIVE EMBODIMENT
Referring now to FIGS. 5 and 6 in combination, there is shown a second alternative embodiment wherein the shank 30 is recessed inside of the opening 44 of burr 42. Hardened insert 88d of the burr 42 are the leading inserts used to fracture the formation. They also extend over the seal 78 to protect it from the cuttings. Three flow passages 92 that connect to flow passage 16 provide a high volume of jetted fluid to the bottom of the hole for rapid removal of cuttings. The three flow passages 92 insure a more equal distribution and higher flow rate of fluid to the bottom of the hole. Depending upon the particular requirements of the individual situation, a nozzle 94 may be located in retainer 96 at the bottom of flow passages 92. Any particular size nozzle 94 desired may be used depending upon the particular situation. By using a nozzle 94, the fluid can be ejected at a high velocity against the formation through which the knobby bit is drilling. Location of the three flow passages 92 in shank 30 can best be seen in FIG. 6.
In the second alternative embodiment, chamber 56 may be refilled with lubricant through grease fitting 96. Grease flows into bore 98 which connects to chamber 56 by means of slot 100. The grease fitting 96 is protected by means of cap nut 102.
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A partially solid head bit having a flow passage therethrough located at approximately the center of the bit is shown. The bit is designed for use in conjunction with a hammer action drilling apparatus. The flow passage extends through a shank of the bit to the bottom thereof. Surrounding the shank is a substantially hemispherical spiraled burr having an opening therethrough. The burr pushes against a shoulder of the shank during drilling. The mating surfaces of the shank and burr are lubricated by a suitable oil reservoir. On spirals of the burr and on the lower end of the shank are mounted hardened inserts for impacting against and breaking up the formation through which the bit may drill. The bottom of the shank may be even with, extend through, or be recessed with respect to the lower edge of the burr. The shank is angled a few degrees off the centerline of the drilling string to cause a wobbling action upon rotating the drill bit.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of application Ser. No. 09/565,864, filed May 5, 2000, now U.S. Pat. No. 6,455,245 B1, issued Sep. 24, 2002, which itself is a divisional application of application Ser. No. 08/747,863, filed Nov. 13, 1996, now U.S. Pat. No. 6,197,310 B1, issued Mar. 6, 2001, which itself is a divisional of U.S. patent application Ser. No. 08/157,005, filed Nov. 26, 1993, now U.S. Pat. No. 5,620,691, which is a U.S. National Stage under 35 U.S.C. § 371 of International Patent Application PCT/NL92/00096, filed Jun. 5, 1992, the contents of all of which are incorporated by this reference.
TECHNICAL FIELD
The invention relates to the isolation, characterization and utilization of the causative agent of the Mystery Swine Disease (MSD). The invention utilizes the discovery of the agent causing the disease and the determination of its genome organization, the genomic nucleotide sequence and the proteins encoded by the genome, for providing protection against and diagnosis of infections, in particular, protection against and diagnosis of MSD infections, and for providing vaccine compositions and diagnostic kits, either for use with MSD or with other pathogen-caused diseases.
BACKGROUND
In the winter and early spring of 1991, the Dutch pig industry was struck by a sudden outbreak of a new disease among breeding sows. Most sows showed anorexia, some aborted late in gestation (around day 110), showed stillbirths or gave birth to mummified fetuses and some had fever. Occasionally, sows with bluish ears were found, therefore, the disease was commonly named “Abortus Blauw”. The disease in the sows was often accompanied by respiratory distress and death of their young piglets and often by respiratory disease and growth retardation of older piglets and fattening pigs.
The cause of this epizootic was not known, but the symptoms resembled those of a similar disease occurring in Germany since late 1990, and resembled those of the so-called “Mystery Swine Disease” as seen since 1987 in the mid-west of the United States of America and in Canada (Hill, 1990). Various other names have been used for the disease; in Germany it is known as “Seuchenhafter Spätabort der Schweine” and in North America it is also known as “Mystery Pig Disease”, “Mysterious Reproductive Syndrome”, and “Swine Infertility and Respiratory Syndrome”. In North America, Loula (1990) described the general clinical signs as:
1) off feed, sick animals of all ages;
2) abortions, stillbirths, weak pigs, mummies;
3) post-farrowing respiratory problems; and
4) breeding problems.
No causative agent has as yet been identified, but encephalomyocarditis virus (“EMCV”), porcine parvo virus (“PPV”), pseudorabies virus (“PRV”), swine influenza virus (“SIV”), bovine viral diarrhea virus (“BVDV”), hog cholera virus (“HCV”), porcine entero viruses (“PEV”), an influenza-like virus, chlamidiae, leptospirae, have all been named as a possible cause (Loula, 1990; Mengeling and Lager, 1990; among others).
SUMMARY OF THE INVENTION
The invention provides a composition of matter comprising isolated Lelystad Agent which is the causative agent of Mystery Swine Disease, the Lelystad Agent essentially corresponding to the isolate Lelystad Agent (CDI-NL-2.91) deposited Jun. 5, 1991 with the Institut Pasteur, Collection Nationale de Cultures De Microorganismes (C.N.C.M.) 25, rue du Docteur Roux, 75724-Paris Cedex 15, France, deposit number I-1102. The words “essentially corresponding” refer to variations that occur in nature and to artificial variations of Lelystad Agent, particularly those which still allow detection by techniques like hybridization, PCR and ELISA, using Lelystad Agent-specific materials, such as Lelystad Agent-specific DNA or antibodies.
The composition of matter may comprise live, killed, or attenuated isolated Lelystad Agent; a recombinant vector derived from Lelystad Agent; an isolated part or component of Lelystad Agent; isolated or synthetic protein (poly)peptide, or nucleic acid derived from Lelystad Agent; recombinant nucleic acid which comprises a nucleotide sequence derived from the genome of Lelystad Agent; a (poly)peptide having an amino acid sequence derived from a protein of Lelystad Agent, the (poly)peptide being produced by a cell capable of producing it due to genetic engineering with appropriate recombinant DNA; an isolated or synthetic antibody which specifically recognizes a part or component of Lelystad Agent; or a recombinant vector which contains nucleic acid comprising a nucleotide sequence coding for a protein or antigenic peptide derived from Lelystad Agent.
On the DNA level, the invention specifically provides a recombinant nucleic acid, more specifically recombinant DNA, which comprises a Lelystad Agent-specific nucleotide sequence shown in FIG. 1 (SEQ ID NO: 1) which includes FIGS. 1 a ; through 1 q . Preferably, the Lelystad Agent-specific nucleotide sequence is selected from any one of the ORFs (Open Reading Frames) shown in FIG. 1 (SEQ ID NO: 1).
On the peptide/protein level, the invention specifically provides a peptide comprising a Lelystad Agent-specific amino acid sequence shown in FIG. 1 (SEQ ID NO: 1).
The invention further provides a vaccine composition for vaccinating animals, in particular mammals, more in particular pigs or swine, to protect them against Mystery Swine Disease, comprising Lelystad Agent, either live, killed, or attenuated; or a recombinant vector which contains nucleic acid comprising a nucleotide sequence coding for a protein or antigenic peptide derived from Lelystad Agent; an antigenic part or component of Lelystad Agent; a protein or antigenic polypeptide derived from, or a peptide mimicking an antigenic component of, Lelystad Agent; and a suitable carrier or adjuvant.
The invention also provides a vaccine composition for vaccinating animals, in particular mammals, more in particular pigs or swine, to protect them against a disease caused by a pathogen, comprising a recombinant vector derived from Lelystad Agent, the nucleic acid of the recombinant vector comprising a nucleotide sequence coding for a protein or antigenic peptide derived from the pathogen, and a suitable carrier or adjuvant.
The invention further provides a diagnostic kit for detecting nucleic acid from Lelystad Agent in a sample, in particular a biological sample such as blood or blood serum, sputum, saliva, or tissue, derived from an animal, in particular a mammal, more in particular a pig or swine, comprising a nucleic acid probe or primer which comprises a nucleotide sequence derived from the genome of Lelystad Agent, and suitable detection means of a nucleic acid detection assay.
The invention also provides a diagnostic kit for detecting antigen from Lelystad Agent in a sample, in particular a biological sample such as blood or blood serum, sputum, saliva, or tissue, derived from an animal, in particular a mammal, more in particular a pig or swine, comprising an antibody which specifically recognizes a part or component of Lelystad Agent, and suitable detection means of an antigen detection assay.
The invention also provides a diagnostic kit for detecting an antibody which specifically recognizes Lelystad Agent in a sample, in particular a biological sample such as blood or blood serum, sputum, saliva, or tissue, derived from an animal, in particular a mammal, more in particular a pig or swine, comprising Lelystad Agent; an antigenic part or component of Lelystad Agent; a protein or antigenic polypeptide derived from Lelystad Agent; or a peptide mimicking an antigenic component of Lelystad Agent; and suitable detection means of an antibody detection assay.
The invention also relates to a process for diagnosing whether an animal, in particular a mammal, more in particular a pig or swine, is contaminated with the causative agent of Mystery Swine Disease, comprising preparing a sample, in particular a biological sample such as blood or blood serum, sputum, saliva, or tissue, derived from the animal, and examining whether it contains Lelystad Agent nucleic acid, Lelystad Agent antigen, or antibody specifically recognizing Lelystad Agent, the Lelystad Agent being the causative agent of Mystery Swine Disease and essentially corresponding to the isolate Lelystad Agent (CDI-NL-2.91) deposited 5 Jun. 1991 with the Institut Pasteur, Paris, France, deposit number I-1102.
DETAILED DESCRIPTION OF THE INVENTION
The invention is a result of combined efforts of the Central Veterinary Institute (CVI) and the Regional Animal Health Services (RAHS) in the Netherlands in trying to find the cause of the new disease MSD. Farms with pigs affected by the new disease were visited by field veterinarians of the RAHS. Sick pigs, specimens of sick pigs, and sow sera taken at the time of the acute and convalescent phase of the disease were sent for virus isolation to the RAHS and the CVI. Paired sera of affected sows were tested for antibodies against ten known pig-viruses. Three different viruses, encephalomyocarditis virus, porcine entero virus type 2, porcine entero virus type 7, and an unknown agent, Lelystad Agent (LA), were isolated. Sows which had reportedly been struck with the disease mainly seroconverted to LA, and rarely to any of the other virus isolates or the known viral pathogens. In order to reproduce MSD experimentally, eight pregnant sows were inoculated intranasally with LA at day 84 of gestation. One sow gave birth to seven dead and four live but very weak piglets at day 109 of gestation; the four live piglets died one day after birth. Another sow gave birth at day 116 to three mummified fetuses, six dead piglets and three live piglets; two of the live piglets died within one day. A third sow gave birth at day 117 to two mummified fetuses, eight dead and seven live piglets. The other sows farrowed around day 115 and had less severe reproductive losses. The mean number of live piglets from all eight sows at birth was 7.3 and the mean number of dead piglets at birth was 4.6. Antibodies directed against LA were detected in 10 out of 42 serum samples collected before the pigs had sucked. LA was isolated from three piglets that died shortly after birth. These results justify the conclusion that LA is the causal agent of mystery swine disease.
LA grows with a cytopathic affect in pig lung macrophages and can be identified by staining in an immuno-peroxidase-monolayer assay (IPMA) with post-infection sera of pigs c 829 and b 822, or with any of the other post-infection sera of the SPF pigs listed in table 5. Antibodies to LA can be identified by indirect staining procedures in IPMA. LA did not grow in any other cell system tested. LA was not neutralized by homologous sera, or by sera directed against a set of known viruses (Table 3). LA did not haemagglutinate with the red blood cells tested. LA is smaller then 200 nm since it passes through a filter with pores of this size. LA is sensitive to chloroform. The above results show that Lelystad Agent is not yet identified as belonging to a certain virus group or other microbiological species. It has been deposited 5 Jun. 1991 under number I-1102 at Institute Pasteur, France.
The genome organization, nucleotide sequences, and polypeptides derived therefrom, of LA have now been found. These data together with those of others (see below) justify classification of LA (hereafter also called Lelystad Virus or LV) as a member of a new virus family, the Arteriviridae. As prototype virus of this new family we propose Equine Arteritis Virus (EAV), the first member of the new family of which data regarding the replication strategy of the genome and genome organization became available (de Vries et al., 1990, and references therein). On the basis of a comparison of our sequence data with those available for Lactate Dehydrogenase-Elevating Virus (LDV; Godeny et al., 1990), we propose that LDV is also a member of the Arteriviridae.
Given the genome organization and translation strategy of Arteriviridae, it seems appropriate to place this new virus family into the superfamily of coronaviruses (Snijder et al., 1990a).
Arteriviruses have in common that their primary target cells in respective hosts are macrophages. Replication of LDV has been shown to be restricted to macrophages in its host, the mouse; whereas this strict propensity for macrophages has not been resolved yet for EAV and LV.
Arteriviruses are spherical enveloped particles having a diameter of 45-60 nm and containing an icosahedral nucleocapsid (Brinton-Darnell and Plagemann, 1975; Horzinek et al., 1971; Hyllseth, 1973).
The genome of Arteriviridae consists of a positive stranded polyadenylated RNA molecule with a size of about 12-13 kilobases (kb) (Brinton-Darnell and Plageman, 1975; van der Zeijst et al., 1975). EAV replicates via a 3′ nested set of six subgenomic mRNAs, ranging in size from 0.8 to 3.6 kb, which are composed of a leader sequence, derived from the 5′ end of the genomic RNA, which is joined to the 3′ terminal body sequences (de Vries et al., 1990).
Here we show that the genome organization and replication strategy of LV is similar to that of EAV, coronaviruses and toroviruses, whereas the genome sizes of the latter viruses are completely different from those of LV and EAV.
The genome of LV consists of a genomic RNA molecule of about 14.5 to 15.5 kb in length (estimated on a neutral agarose gel), which replicates via a 3′ nested set of subgenomic RNAs. The subgenomic RNAs consist of a leader sequence, the length of which is yet unknown, which is derived from the 5′ end of the genomic RNA and which is fused to the body sequences derived from the 3′ end of the genomic RNA (FIG. 2 ).
The nucleotide sequence of the genomic RNA of LV was determined from overlapping cDNA clones. A consecutive sequence of 15,088 bp was obtained covering nearly the complete genome of LV (FIG. 1, SEQ ID NO: 1). In this sequence 8 open reading frames (ORFs) were identified: ORF 1A, ORF 1B, and ORFs 2 to 7.
ORF 1A and ORF 1B are predicted to encode the viral replicase or polymerase (SEQ ID NO: 2 and SEQ ID NO: 3), whereas ORFs 2 to 6 are predicted to encode structural viral membrane (envelope) associated proteins (SEQ ID NOS: 4-8). ORF 7 is predicted to encode the structural viral nucleocapsid protein (SEQ ID NO: 9).
Because the products of ORF 6 and ORF 7 of LV (SEQ ID NO: 8 and SEQ ID NO: 9) show a significant similarity with VpX and Vp1 of LDV, respectively, it is predicted that the sequences of ORFs 6 and 7 will also be highly conserved among antigenic variants of LV.
The complete nucleotide sequence of FIG. 1 (SEQ ID NO: 1) and all the sequences and protein products encoded by ORFs 1 to 7 (SEQ ID NOS: 1-9) and possible other ORFs located in the sequence of FIG. 1 (SEQ ID NO: 1) are especially suited for vaccine development, in whatever sense, and for the development of diagnostic tools, in whatever sense. All possible modes are well known to persons skilled in the art.
Since it is now possible to unambiguously identify LA, the causal agent of MSD, it can now be tested whether pigs are infected with LA or not. Such diagnostic tests have, until now, been unavailable.
The test can be performed by virus isolation in macrophages, or other cell culture systems in which LA might grow, and staining the infected cultures with antibodies directed against LA (such as post-infection sera c 829 or b 822), but it is also feasible to develop and employ other types of diagnostic tests.
For instance, it is possible to use direct or indirect immunohistological staining techniques, i.e., with antibodies directed to LA that are labeled with fluorescent compounds such as isothiocyanate, or labeled with enzymes such as horseradish peroxidase. These techniques can be used to detect LA antigen in tissue sections or other samples from pigs suspected to have MSD. The antibodies needed for these tests can be c 829 or b 822 or other polyclonal antibodies directed against LA, but monoclonal antibodies directed against LA can also be used.
Furthermore, since the nature and organization of the genome of LA and the nucleotide sequence of this genome have been determined, LA-specific nucleotide sequences can be identified and used to develop oligonucleotide sequences that can be used as probes or primers in diagnostic techniques such as hybridization, polymerase chain reaction, or any other techniques that are developed to specifically detect nucleotide acid sequences.
It is also possible to test for antibodies directed against LA. Table 5 shows that experimentally infected pigs rapidly develop antibodies against LA, and table 4 shows that pigs in the field also have strong antibody responses against LA. Thus, it can now also be determined whether pigs have been infected with LA in the past. Such testing is of utmost importance in determining whether pigs or pig herds or pig populations or pigs in whole regions or countries are free of LA. The test can be done by using the IPMA as described, but it is also feasible to develop and employ other types of diagnostic tests for the detection of antibodies directed against LA.
LA-specific proteins, polypeptides, and peptides, or peptide sequences mimicking antigenic components of LA, can be used in such tests. Such proteins can be derived from the LA itself, but it is also possible to make such proteins by recombinant DNA or peptide synthesis techniques. These tests can use specific polyclonal and/or monoclonal antibodies directed against LA or specific components of LA, and/or use cell systems infected with LA or cell systems expressing LA antigen. The antibodies can be used, for example, as a means for immobilizing the LA antigen (a solid surface is coated with the antibody whereafter the LA antigen is bound by the antibody) which leads to a higher specificity of the test, or can be used in a competitive assay (labeled antibody and unknown antibody in the sample compete for available LA antigen).
Furthermore, the above described diagnostic possibilities can be applied to test whether other animals, such as mammals, birds, insects or fish, or plants, or other living creatures, can be, or are, or have been infected with LA or related agents.
Since LA has now been identified as the causal agent of MSD, it is possible to make a vaccine to protect pigs against this disease. Such a vaccine can simply be made by growing LA in pig lung macrophage cultures, or in other cell systems in which LA grows. LA can then be purified or not, and killed by established techniques, such as inactivation with formaline or ultra-violet light. The inactivated LA can then be combined with adjuvantia, such as Freund's adjuvans or aluminum hydroxide or others, and this composition can then be injected in pigs.
Dead vaccines can also be made with LA protein preparations derived from LA infected cultures, or derived from cell systems expressing specifically LA protein through DNA recombinant techniques. Such subunits of LA would then be treated as above, and this would result in a subunit vaccine.
Vaccines using even smaller components of LA, such as polypeptides, peptides, or peptides mimicking antigenic components of LA, are also feasible for use as dead vaccine.
Dead vaccines against MSD can also be made by recombinant DNA techniques through which the genome of LA, or parts thereof, is incorporated in vector systems such as vaccinia virus, herpesvirus, pseudorabies virus, adeno virus, baculo virus or other suitable vector systems that can so express LA antigen in appropriate cells systems. LA antigen from these systems can then be used to develop a vaccine as above, and pigs, vaccinated with such products would develop protective immune responses against LA.
Vaccines against MSD can also be based on live preparations of LA. Since only young piglets and pregnant sows seem to be seriously affected by infection with LA, it is possible to use unattenuated LA, grown in pig lung macrophages, as vaccine for older piglets, or breeding gilts. In this way, sows can be protected against MSD before they get pregnant, which results in protection against abortions and stillbirth, and against congenital infections of piglets. Also the maternal antibody that these vaccinated sows give to their offspring would protect their offspring against the disease.
Attenuated vaccines (modified-live-vaccines) against MSD can be made by serially passaging LA in pig lung macrophages, in lung macrophages of other species, or in other cell systems, or in other animals, such as rabbits, until it has lost its pathogenicity.
Live vaccines against MSD can also be made by recombinant DNA techniques through which the genome of LA, or parts thereof, is incorporated in vector systems such as vaccinia virus, herpesvirus, pseudorabies virus, adeno virus or other suitable vector systems that can so express LA antigen. Pigs vaccinated with such live vector systems would then develop protective immune responses against LA.
Lelystad Agent itself would be specifically suited to use as a live vector system. Foreign genes could be inserted in the genome of LA and could be expressing the corresponding protein during the infection of the macrophages. This cell, which is an antigen-presenting cell, would process the foreign antigen and present it to B-lymphocytes and T-lymphocytes which will respond with the appropriate immune response.
Since LA seems to be very cell specific and possibly also very species specific, this vector system might be a very safe system, which does not harm other cells or species.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 (SEQ ID NO: 1) shows the nucleotide sequence of the LV genome. The deduced amino acid sequence of the identified ORFs (SEQ ID NOS: 2-9) are shown. The methionines encoded by the (putative) ATG start sites are indicated in bold and putative N-glycosylation sites are underlined. Differences in the nucleotide and amino acid sequence, as identified by sequencing different cDNA clones, are shown. The nucleotide sequence of primer 25, which has been used in hybridization experiments (see FIG. 2 and section “results”), is underlined.
FIG. 2 shows the organization of the LV genome. The cDNA clones, which have been used for the determination of the nucleotide sequence, are indicated in the upper part of the figure. The parts of the clones, which were sequenced, are indicated in black. In the lower part of the figure the ORFs, identified in the nucleotide sequence, and the subgenomic set of mRNAs, encoding these ORFs are shown. The dashed lines in the ORFs represent alternative initiation sites (ATGs) of these ORFs. The leader sequence of the genomic and subgenomic RNAs is indicated by a solid box.
FIG. 3 shows the growth characteristics of LA:
empty squares—titre of cell-free virus;
solid squares—titre of cell-associated virus;
solid line—percentage cytopathic effect (CPE).
MATERIALS AND METHODS
Sample Collection
Samples and pigs were collected from farms where a herd epizootic of MSD seemed to occur. Important criteria for selecting the farm as being affected with MSD were: sows that were off feed, the occurrence of stillbirth and abortion, weak offspring, respiratory disease and death among young piglets. Samples from four groups of pigs have been investigated:
(1) tissue samples and an oral swab from affected piglets from the field (Table 1A);
(2) blood samples and oral swabs from affected sows in the field (Tables 1B and 4);
(3) tissue samples, nasal swabs and blood samples collected from specific-pathogen-free (SPF) pigs experimentally infected by contact with affected sows from the field; or
(4) tissue samples, nasal swabs and blood samples collected from specific-pathogen-free (SPF) pigs experimentally infected by inoculation with blood samples of affected sows from the field (Tables 2 and 5).
Sample Preparation
Samples for virus isolation were obtained from piglets and sows which on clinical grounds were suspected to have MSD, and from experimentally infected SPF pigs, sows and their piglets.
Tissue samples were cut on a cryostat microtome and sections were submitted for direct immunofluorescence testing (IFT) with conjugates directed against various pig pathogens.
10% Suspensions of tissues samples were prepared in Hank's BSS supplemented with antibiotics, and oral and nasal swabs were soaked in Hank's BSS supplemented with antibiotics. After one hour at room temperature, the suspensions were clarified for 10 min at 6000 g and the supernatant was stored at −70° C. for further use. Leucocyte fractions were isolated from EDTA or heparin blood as described earlier (Wensvoort and Terpstra, 1988) and stored at −70° C. Plasma and serum for virus isolation were stored at −70° C.
Serum for serology was obtained from sows suspected to be in the acute phase of MSD, a paired serum was taken 3-9 weeks later. Furthermore, sera were taken from the experimentally infected SPF pigs at regular intervals and colostrum and serum was taken from experimentally infected sows and their piglets. Sera for serology were stored at −20° C.
Cells
Pig lung macrophages were obtained from lungs of 5-6 weeks old SPF pigs or from lungs of adult SPF sows from the Central Veterinary Institute's own herd. The lungs were washed five to eight times with phosphate buffered saline (PBS). Each aliquot of washing fluid was collected and centrifuged for 10 min at 300 g. The resulting cell pellet was washed again in PBS and resuspended in cell culture medium (160 ml medium 199, supplemented with 20 ml 2.95% tryptose phosphate, 20 ml fetal bovine serum (FBS), and 4.5 ml 1.4% sodium bicarbonate) to a concentration of 4×10 7 cells/ml. The cell suspension was then slowly mixed with an equal volume of DMSO mix (6.7 ml of above medium, 1.3 ml FBS, 2 ml dimethylsulfoxide 97%), aliquoted in 2 ml ampoules and stored in liquid nitrogen.
Macrophages from one ampoule were prepared for cell culture by washing twice in Earle's MEM, and resuspended in 30 ml growth medium (Earle's MEM, supplemented with 10% FBS, 200 U/ml penicillin, 0.2 mg/ml streptomycine, 100 U/ml mycostatin, and 0.3 mg/ml glutamine). PK-15 cells (American Type Culture Collection, CCL33) and SK-6 cells (Kasza et al., 1972) were grown as described by Wensvoort et al. (1989). Secondary porcine kidney (PK2) cells were grown in Earle's MEM, supplemented with 10% FBS and the above antibiotics. All cells were grown in a cell culture cabinet at 37° C. and 5% CO 2 .
Virus Isolation Procedures
Virus isolation was performed according to established techniques using PK2, PK-15 and SK-6 cells, and pig lung macrophages. The former three cells were grown in 25 ml flasks (Greiner), and inoculated with the test sample when monolayers had reached 70-80% confluency. Macrophages were seeded in 100 μl aliquots in 96-well microtiter plates (Greiner) or in larger volumes in appropriate flasks, and inoculated with the test sample within one hour after seeding. The cultures were observed daily for cytopathic effects (CPE), and frozen at −70° C. when 50-70% CPE was reached or after five to ten days of culture. Further passages were made with freeze-thawed material of passage level 1 and 2 or higher. Some samples were also inoculated into nine to twelve day old embryonated hen eggs. Allantoic fluid was subinoculated two times using an incubation interval of three days and the harvest of the third passage was examined by haemagglutination at 4° C. using chicken red blood cells, and by an ELISA specifically detecting nucleoprotein of influenza A viruses (De Boer et al., 1990).
Serology
Sera were tested in haemagglutinating inhibition tests (HAI) to study the development of antibody against haemagglutinating encephalitis virus (HEV), and swine influenza viruses H1N1 and H3N2 according to the protocol of Masurel (1976). Starting dilutions of the sera in HAI were 1:9, after which the sera were diluted twofold.
Sera were tested in established enzyme-linked immuno-sorbent assays (ELISA) for antibodies against the glycoprotein gI of pseudorabies virus (PRV; Van Oirschot et al., 1988), porcine parvo virus (PPV; Westenbrink et al., 1989), bovine viral diarrhea virus (BVDV; Westenbrink et al., 1986), and hog cholera virus (HCV; Wensvoort et al., 1988). Starting dilutions in the ELISA's were 1:5, after which the sera were diluted twofold.
Sera were tested for neutralizing antibodies against 30-300 TCID 50 of encephalomyocarditis viruses (EMCV), porcine enteroviruses (PEV), and Lelystad Agent (LA) according to the protocol of Terpstra (1978). Starting dilutions of the sera in the serum neutralization tests (SNT) were 1:5, after which the sera were diluted twofold.
Sera were tested for binding with LA in an immuno-peroxidase-monolayer assay (IPMA). Lelystad Agent (LA; code: CDI-NL-2.91) was seeded in microtiter plates by adding 50 ml growth medium containing 100 TCID 50 LA to the wells of a microtiter plate containing freshly seeded lung macrophages. The cells were grown for two days and then fixed as described (Wensvoort, 1986). The test sera were diluted 1:10 in 0.15 M NaCl, 0.05% Tween 80, 4% horse serum, or diluted further in fourfold steps, added to the wells and then incubated for one hour at 37° C. Sheep-anti-pig immunoglobulins (Ig) conjugated to horse radish peroxidase (HRPO, DAKO) were diluted in the same buffer and used in a second incubation for one hour at 37° C., after which the plates were stained as described (Wensvoort et al., 1986). An intense red staining of the cytoplasm of infected macrophages indicated binding of the sera to LA.
Virus Identification Procedures
The identity of cytopathic isolates was studied by determining the buoyant density in CsCl, by estimating particle size in negatively stained preparations through electron microscopy, by determining the sensitivity of the isolate to chloroform and by neutralizing the CPE of the isolate with sera with known specificity (Table 3). Whenever an isolate was specifically neutralized by a serum directed against a known virus, the isolate was considered to be a representative of this known virus.
Isolates that showed CPE on macrophage cultures were also studied by staining in IPMA with post-infection sera of pigs c 829 or b 822. The isolates were reinoculated on macrophage cultures and fixed at day 2 after inoculation before the isolate showed CPE. Whenever an isolate showed reactivity in IPMA with the post-infection sera of pigs c 829 or b 822, the isolate was considered to be a representative of the Lelystad Agent. Representatives of the other isolates grown in macrophages or uninfected macrophages were also stained with these sera to check the specificity of the sera.
Further Identification of Lelystad Agent
Lelystad Agent was further studied by haemagglutination at 4° C. and 37° C. with chicken, guinea pig, pig, sheep, or human O red blood cells. SIV, subtype H3N2, was used as positive control in the haemagglutination studies.
The binding of pig antisera specifically directed against pseudorabies virus (PRV), transmissible gastroenteritis virus (TGE), porcine epidemic diarrhea virus (PED), haemagglutinating encephalitis virus (HEV), African swine fever virus (ASFV), hog cholera virus (HCV) and swine influenza virus (SIV) type H1N1 and H3N2, of bovine antisera specifically directed against bovine herpes viruses type 1 and 4 (BHV 1 and 4), malignant catarrhal fever (MCF), parainfluenza virus 3 (PI3), bovine respiratory syncitial virus (BRSV) and bovine leukemia virus (BLV), and of avian antisera specifically directed against avian leukemia virus (ALV) and infectious bronchitis virus (IBV) was studied with species-Ig-specific HRPO conjugates in an IPMA on LA infected and uninfected pig lung macrophages as described above.
We also tested in IPMA antisera of various species directed against mumps virus, Sendai virus, canine distemper virus, rinderpest virus, measles virus, pneumonia virus of mice, bovine respiratory syncytial virus, rabies virus, foamy virus, maedi-visna virus, bovine and murine leukemia virus, human, feline and simian immunodeficiency virus, lymphocytic choriomeningitis virus, feline infectious peritonitis virus, mouse hepatitis virus, Breda virus, Hantaan virus, Nairobi sheep disease virus, Eastern, Western and Venezuelan equine encephalomyelitis virus, rubellavirus, equine arteritis virus, lactic dehydrogenase virus, yellow fever virus, tick-born encephalitis virus and hepatitis C virus.
LA was blindly passaged in PK2, PK-15, and SK-6 cells, and in embryonated hen eggs. After two passages, the material was inoculated again into pig lung macrophage cultures for reisolation of LA.
LA was titrated in pig lung macrophages prior to and after passing through a 0.2 micron filter (Schleicher and Schuell). The LA was detected in IPMA and by its CPE. Titres were calculated according to Reed and Muench (1938).
We further prepared pig antisera directed against LA. Two SPF pigs (21 and 23) were infected intranasally with 10 5 TCID 50 of a fifth cell culture passage of LA. Two other SPF pigs (25 and 29) were infected intranasally with a fresh suspension of the lungs of an LA-infected SPF piglet containing 10 5 TCID 50 LA. Blood samples were taken at 0, 14, 28, and 42 days post-infection (dpi).
We further grew LA in porcine alveolar macrophages to determine its growth pattern over time. Porcine alveolar macrophages were seeded in F25 flasks (Greiner), infected with LA with a multiplicity of infection of 0.01 TCID 50 per cell. At 8, 16, 24, 32, 40, 48, 56, and 64 h after infection, one flask was examined and the percentage of CPE in relation to a noninfected control culture was determined. The culture medium was then harvested and replaced with an equal volume of phosphate-buffered saline. The medium and the flask were stored at −70° C. After all cultures had been harvested, the LA titres were determined and expressed as log TCID 50 ml −1 .
The morphology of LA was studied by electronmicroscopy. LA was cultured as above. After 48 h, the cultures were freeze-thawed and centrifuged for 10 min at 6000.times.g. An amount of 30 ml supernatant was then mixed with 0.3 ml LA-specific pig serum and incubated for 1.5 h at 37° C. After centrifugation for 30 min at 125,000× g, the resulting pellet was suspended in 1% Seakem agarose ME in phosphate-buffered saline at 40° C. After coagulation, the agarose block was immersed in 0.8% glutaraldehyde and 0.8% osmiumtetroxide (Hirsch et al., 1968) in veronal/acetate buffer, pH 7.4 (230 mOsm/kg H 2 O), and fixed by microwave irradiation. This procedure was repeated once with fresh fixative. The sample was washed with water, immersed in 1% uranyl acetate, and stained by microwave irradiation. Throughout all steps, the sample was kept at 0° C. and the microwave (Samsung RE211D) was set at defrost for 5 min. Thin sections were prepared with standard techniques, stained with lead citrate (Venable et al., 1965), and examined in a Philips CM 10 electron microscope.
We further continued isolating LA from sera of pigs originating from cases of MSD. Serum samples originated from the Netherlands (field case the Netherlands 2), Germany (field cases Germany 1 and Germany 2; courtesy Drs. Berner, Müinchen and Nienhoff, Münster), and the United States [experimental case United States 1 (experiment performed with ATCC VR-2332; courtesy Drs. Collins, St. Paul and Chladek, St. Joseph), and field cases United States 2 and United States 3; courtesy Drs. van Alstine, West Lafayette and Slife, Galesburg]. All samples were sent to the “Centraal Diergeneeskundig Instituut, Lelystad” for LA diagnosis. All samples were used for virus isolation on porcine alveolar macrophages as described. Cytophatic isolates were passaged three times and identified as LA by specific immunostaining with anti-LA post infection sera b 822 and c 829.
We also studied the antigenic relationships of isolates NL1 (the first LA isolate; code CDI-NL-2.91), NL2, GE1, GE2, US1, US2, and US3. The isolates were grown in macrophages as above and were tested in IPMA with a set of field sera and two sets of experimental sera. The sera were also tested in IPMA with uninfected macrophages.
The field sera were: Two sera positive for LV (TH-187 and TO-36) were selected from a set of LA-positive Dutch field sera. Twenty-two sera were selected from field sera sent from abroad to Lelystad for serological diagnosis. The sera originated from Germany (BE-352, BE-392 and NI-f2; courtesy Dr. Berner, München and Dr. Nienhoff, Münster), the United Kingdom (PA-141615, PA-141617 and PA-142440; courtesy Dr. Paton, Weybridge), Belgium (PE-1960; courtesy Prof. Pensaert, Gent), France (EA-2975 and EA-2985; courtesy Dr. Albina, Ploufragan), the United States (SL-441, SL-451, AL-RP9577, AL-P10814/33, AL-4994A, AL-7525, JC-MN41, JC-MN44 and JC-MN45; courtesy Dr. Slife, Galesburg, Dr. van Alstine, West Lafayette, and Dr. Collins, St. Paul), and Canada (RB-16, RB-19, RB-22 and RB-23; courtesy Dr. Robinson, Quebec).
The experimental sera were: The above described set of sera of pigs 21, 23, 25, and 29, taken at dpi 0, 14, 28, and 42. A set of experimental sera (obtained by courtesy of Drs. Chladek, St. Joseph, and Collins, St. Paul) that originated from four six-month-old gilts that were challenged intranasally with 10 5.1 TCID 50 of the isolate ATCC VR-2332. Blood samples were taken from gilt 2B at 0, 20, 36, and 63 dpi; from gilt 9G at 0, 30, 44, and 68 dpi; from gilt 16W at 0, 25, 40, and 64 dpi; and from gilt 16Y at 0, 36, and 64 dpi.
To study by radio-immunoprecipitation assay (RIP; de Mazancourt et al., 1986) the proteins of LA in infected porcine alveolar macrophages, we grew LA-infected and uninfected macrophages for 16 hours in the presence of labeling medium containing 35 S-Cysteine. Then the labeled cells were precipitated according to standard methods with 42 dpi post-infection sera of pig b 822 and pig 23 and with serum MN 8 which was obtained 26 days after infecting a sow with the isolate ATCC VR-2332 (courtesy Dr. Collins, St. Paul). The precipitated proteins were analyzed by electrophoresis in a 12% SDS-PAGE gel and visualized by fluorography.
To characterize the genome of LA, we extracted nuclear DNA and cytoplasmatic RNA from macrophage cultures that were infected with LA and grown for 24 h or were left uninfected. The cell culture medium was discarded, and the cells were washed twice with phosphate-buffered saline. DNA was extracted as described (Strauss, 1987). The cytoplasmic RNA was extracted as described (Favaloro et al., 1980), purified by centrifugation through a 5.7 M CsCl cushion (Setzer et al., 1980), treated with RNase-free DNase (Pharmacia), and analyzed in a 0.8% neutral agarose gel (Moormann and Hulst, 1988).
Cloning and Sequencing
To clone LV RNA, intracellular RNA of LV-infected porcine lung alveolar macrophages (10 μg) was incubated with 10 mM methylmercury hydroxide for 10 minutes at room temperature. The denatured RNA was incubated at 42° C. with 50 mM Tris-HCI, pH 7.8, 10 mM MgCl 2 , 70 mM KCl, 0.5 mM dATP, dCTP, dGTP and dTTP, 0.6 μg calf thymus oligonucleotide primers pd(N)6 (Pharmacia) and 300 units of Moloney murine leukemia virus reverse transcriptase (Bethesda Research Laboratories) in a total volume of 100 μl 20 mM EDTA was added after 1 hr; the reaction mixture was then extracted with phenol/chloroform, passed through a Sephadex G50 column and precipitated with ethanol.
For synthesis of the second cDNA strand, DNA polymerase I (Boehringer) and RNase H (Pharmacia) were used (Gübler and Hoffman, 1983). To generate blunt ends at the termini, double-stranded cDNA was incubated with T4 DNA polymerase (Pharmacia) in a reaction mixture which contained 0.05 mM deoxynucleotide-triphosphates. Subsequently, cDNA was fractionated in a 0.8% neutral agarose gel (Moormann and Hulst, 1988). Fragments of 1 to 4 kb were electroeluted, ligated into the Smal site of pGEM-4Z (Promega), and used for transformation of Escherichia coli strain DH5α (Hanahan, 1985). Colony filters were hybridized with a 32 P-labeled single-stranded cDNA probe. The probe was reverse transcribed from LV RNA which had been fractionated in a neutral agarose gel (Moormann and Hulst, 1988). Before use, the single stranded DNA probe was incubated with cytoplasmic RNA from mock-infected lung alveolar macrophages.
The relationship between LV cDNA clones was determined by restriction enzyme analysis and by hybridization of Southern blots of the digested DNA with nick-translated cDNA probes (Sambrook et al., 1989).
To obtain the 3′ end of the viral genome, we constructed a second cDNA library, using oligo (dT) 12-18 and a 3′ LV-specific oligonucleotide that was complementary to the minus-strand viral genome as a primer in the first-strand reaction. The reaction conditions for first- and second-strand synthesis were identical to those described above. This library was screened with virus-specific 3′ end oligonucleotide probes.
Most (>95%) of the cDNA sequences were determined with an Automated Laser Fluorescent A.L.F.™. DNA sequencer from Pharmacia LKB. Fluorescent oligonucleotide primer directed sequencing was performed on double-stranded DNA using the AutoRead™. Sequencing Kit (Pharmacia) essentially according to procedures C and D described in the Autoread™ Sequencing Kit protocol. Fluorescent primers were prepared with FluorePrime™. (Pharmacia). The remaining part of the sequence was determined via double-stranded DNA sequencing using oligonucleotide primers in conjunction with a T7 polymerase based sequencing kit (Pharmacia) and α- 32 S-dATP (Amersham). Sequence data were analyzed using the sequence analysis programs PCGENE (Intelligenetics, Inc, Mountain View, U.S.A.) and FASTA (Pearson and Lipman, 1988).
Experimental Reproduction of MSD
Fourteen conventionally reared pregnant sows that were pregnant for 10-11 weeks were tested for antibody against LA in the IPMA. All were negative. Then two groups of four sows were formed and brought to the CVI. At week 12 of gestation, these sows were inoculated intranasally with 2 ml LA (passage level 3, titre 10 4.8 TCID 50 /ml). Serum and EDTA blood samples were taken at day 10 after inoculation. Food intake, rectal temperature, and other clinical symptoms were observed daily. At farrowing, the date of birth and the number of dead and living piglets per sow were recorded, and samples were taken for virus isolation and serology.
Results
Immunofluorescence
Tissue sections of pigs with MSD were stained in an IFT with FITC-conjugates directed against African swine fever virus, hog cholera virus, pseudorabies virus, porcine parvo virus, porcine influenza virus, encephalomyocarditis virus and Chlamydia psittaci . The sections were stained, examined by fluorescent microscopy and all were found negative.
Virus Isolation From Piglets From MSD Affected Farms
Cytopathic isolates were detected in macrophage cultures inoculated with tissue samples of MSD affected, two-to-ten day old piglets. Sixteen out of 19 piglets originating from five different farms were positive (Table 1A). These isolates all reacted in IPMA with the post-infection serum of pig c 829, whereas non-inoculated control cultures did not react. The isolates, therefore, were representatives of LA. One time a cytopathic isolate was detected in an SK-6 cell culture inoculated with a suspension of an oral swab from a piglet from a sixth farm (farm VE) (Table 1A). This isolate showed characteristics of the picoma viridae and was neutralized by serum specific for PEV 2, therefore, the isolate was identified as PEV 2 (Table 3). PK2, PK-15 cells and hen eggs inoculated with samples from this group remained negative throughout.
Virus Isolation From Sows From MSD Affected Farms
Cytopathic isolates were detected in macrophage cultures inoculated with samples of MSD affected sows. 41 out of 63 sows originating from 11 farms were positive (Table 1B). These isolates all reacted in IPMA with the post-infection serum of pig b 822 and were, therefore, representatives of LA. On one occasion a cytopathic isolate was detected in a PK2 cell culture inoculated with a suspension of a leucocyte fraction of a sow from farm HU (Table 1B). This isolate showed characteristics of the picoma viridae and was neutralized by serum specific for EMCV, therefore, the isolate was identified as EMCV (Table 3). SK-6, PK-15 cells and hen eggs inoculated with samples from this group remained negative.
Virus Isolation From SPF Pigs Kept in Contact With MSD Affected Sows
Cytopathic isolates were detected in macrophage cultures inoculated with samples of SPF pigs kept in contact with MSD affected sows. Four of the 12 pigs were positive (Table 2). These isolates all reacted in IPMA with the post-infection serum of pig c 829 and of pig b 822 and were, therefore, representatives of LA. Cytopathic isolates were also detected in PK2, PK-15 and SK-6 cell cultures inoculated with samples of these SPF pigs. Seven of the 12 pigs were positive (Table 2), these isolates were all neutralized by serum directed against PEV 7. One of these seven isolates was studied further and other characteristics also identified the isolate as PEV 7 (Table 3).
Virus Isolation From SPF Pigs Inoculated With Blood of MSD Affected Sows
Cytopathic isolates were detected in macrophage cultures inoculated with samples of SPF pigs inoculated with blood of MSD affected sows. Two out of the eight pigs were positive (Table 2). These isolates all reacted in IPMA with the post-infection serum of pig c 829 and of pig b 822 and were, therefore, representatives of LA. PK2, SK-6 and PK-15 cells inoculated with samples from this group remained negative.
Summarizing, four groups of pigs were tested for the presence of agents that could be associated with mystery swine disease (MSD).
In group one, MSD affected piglets, the Lelystad Agent (LA) was isolated from 16 out of 20 piglets; one time PEV 2 was isolated.
In group two, MSD affected sows, the Lelystad Agent was isolated from 41 out of 63 sows; one time EMCV was isolated. Furthermore, 123 out of 165 MSD affected sows seroconverted to the Lelystad Agent, as tested in the IPMA. Such massive seroconversion was not demonstrated against any of the other viral pathogens tested.
In group three, SPF pigs kept in contact with MSD affected sows, LA was isolated from four of the 12 pigs; PEV 7 was isolated from seven pigs. All 12 pigs seroconverted to LA and PEV 7.
In group four, SPF pigs inoculated with blood of MSD affected sows, the LA was isolated from two pigs. All eight pigs seroconverted to LA.
Serology of Sows From MSD Affected Farms
Paired sera from sows affected with MSD were tested against a variety of viral pathogens and against the isolates obtained during this study (Table 4). An overwhelming antibody response directed against LA was measured in the IPMA (75% of the sows seroconverted, in 23 out of the 26 farms seroconversion was found), whereas with none of the other viral pathogens a clear pattern of seroconversion was found. Neutralizing antibody directed against LA was not detected.
Serology of SPF Pigs Kept in Contact With MSD Affected Sows
All eight SPF pigs showed an antibody response in the IPMA against LA (Table 5). None of these sera were positive in the IPMA performed on uninfected macrophages. None of these sera were positive in the SNT for LA. The sera taken two weeks after contact had all high neutralizing antibody titres (>1280) against PEV 7, whereas the pre-infection sera were negative (<10), indicating that all pigs had also been infected with PEV 7.
Serology of SPF Pigs Inoculated With Blood of MSD Affected Sows
All eight SPF pigs showed an antibody response in the IPMA against LA (Table 5). None of these sera were positive in the IPMA performed on uninfected macrophages. None of these sera were positive in the SNT for LA. The pre- and two weeks post-inoculation sera were negative (<10) against PEV 7.
Further Identification of Lelystad Agent
LA did not haemagglutinate with chicken, guinea pig, pig, sheep, or human O red blood cells.
LA did not react in IPMA with sera directed against PRV, TGE, PED, ASFV, etc.
After two blind passages, LA did not grow in PK2, PK-15, or SK-6 cells, or in embryonated hen eggs, inoculated through the allantoic route.
LA was still infectious after it was filtered through a 0.2 micron filter, titres before and after filtration were 10 5.05 and 10 5.3 TCID 50 as detected by IPMA.
Growth curve of LA (see FIG. 3 ). Maximum titres of cell-free virus were approximately 10 5.5 TCID 50 ml −1 from 32-48 h after inoculation. After that time the macrophages were killed by the cytopathic effect of LA.
Electronmicroscopy. Clusters of spherical LA particles were found. The particles measured 45-55 nm in diameter and contained a 30-35 nm nucleocapsid that was surrounded by a lipid bilayer membrane. LA particles were not found in infected cultures that were treated with negative serum or in negative control preparations.
Isolates from the Netherlands, Germany, and the United States. All seven isolates were isolated in porcine alveolar macrophages and passaged three to five times. All isolates caused a cytopathic effect in macrophages and could be specifically immunostained with anti-LA sera b 822 and the 42 dpi serum 23. The isolates were named NL2, GE1, GE 2, US1, US2, and US3.
Antigenic relationships of isolates NL1, NL2, GE1, GE2, US 1, US2, and US3. None of the field sera reacted in IPMA with uninfected macrophages but all sera contained antibodies directed against one or more of the seven isolates (Table 7). None of the experimental sera reacted in IPMA with uninfected macrophages, and none of the 0 dpi experimental sera reacted with any of the seven isolates in IPMA (Table 8). All seven LA isolates reacted with all or most of the sera from the set of experimental sera of pigs 21, 23, 25, and 29, taken after 0 dpi. Only the isolates US1, US2, and US3 reacted with all or most of the sera from the set of experimental sera of gilts 2B, 9G, 16W, and 16Y, taken after 0 dpi.
Radioimmunoprecipitation studies. Seven LA-specific proteins were detected in LA-infected macrophages but not in uninfected macrophages precipitated with the 42 dpi sera of pigs b 822 and 23. The proteins had estimated molecular weights of 65, 39, 35, 26, 19, 16, and 15 kilodalton. Only two of these LA-specific proteins, of 16 and 15 kilodalton, were also precipitated by the 26 dpi serum MN8.
Sequence and Organization of the Genome of LV
The nature of the genome of LV was determined by analyzing DNA and RNA from infected porcine lung alveolar macrophages. No LV-specific DNA was detected. However, we did detect LV-specific RNA. In a 0.8% neutral agarose gel, LV RNA migrated slightly slower than a preparation of hog cholera virus RNA of 12.3 kb (Moormann et al., 1990) did. Although no accurate size determination can be performed in neutral agarose gels, it was estimated that the LV-specific RNA is about 14.5 to 15.5 kb in length.
To determine the complexity of the LV-specific RNAs in infected cells and to establish the nucleotide sequence of the genome of LV, we prepared cDNA from RNA of LV-infected porcine lung alveolar macrophages and selected and mapped LV-specific cDNA clones as described under Materials and Methods. The specificity of the cDNA clones was reconfirmed by hybridizing specific clones, located throughout the overlapping cDNA sequence, to Northern blots carrying RNA of LV-infected and uninfected macrophages. Remarkably, some of the cDNA clones hybridized with the 14.5 to 15.5 kb RNA detected in infected macrophages only, whereas others hybridized with the 14.5 to 15.5 kb RNA as well as with a panel of 4 or 5 RNAs of lower molecular weight (estimated size, 1 to 4 kb). The latter clones were all clustered at one end of the cDNA map and covered about 4 kb of DNA. These data suggested that the genome organization of LV may be similar to that of coronaviridae (Spaan et al., 1988), Berne virus (BEV; Snijder et al., 1990b), a torovirus, and EAV (de Vries et al., 1990), i.e., besides a genomic RNA there are subgenomic mRNAs which form a nested set which is located at the 3′ end of the genome. This assumption was confirmed when sequences of the cDNA clones became available and specific primers could be selected to probe the blots with. A compilation of the hybridization data obtained with cDNA clones and specific primers, which were hybridized to Northern blots carrying the RNA of LV-infected and uninfected macrophages, is shown in FIG. 2 . Clones 12 and 20 which are located in the 5′ part and the centre of the sequence, respectively, hybridize to the 14.5 to 15.5 kb genomic RNA detected in LV-infected cells only. Clones 41 and 39, however, recognize the 14.5 to 15.5 kb genomic RNA and a set of 4 and 5 RNAs of lower molecular weight, respectively. The most instructive and conclusive hybridization pattern, however, was obtained with primer 25, which is located at the ultimate 5′ end in the LV sequence (compare FIG. 1 ). Primer 25 hybridized to a panel of 7 RNAs, with an estimated molecular weight ranging in size from 0.7 to 3.3 kb (subgenomic mRNAs), as well as the genomic RNA. The most likely explanation for the hybridization pattern of primer 25 is that 5′ end genomic sequences, the length of which is yet unknown, fuse with the body of the mRNAs which are transcribed from the 3′ end of the genome. In fact, the hybridization pattern obtained with primer 25 suggests that 5′ end genomic sequences function as a so called “leader sequence” in subgenomic mRNAs. Such a transcription pattern is a hallmark of replication of coronaviridae (Spaan et al., 1988), and of EAV (de Vries et al., 1990).
The only remarkable discrepancy between LV and EAV which could be extracted from the above data is that the genome size of LV is about 2.5 kb larger than that of EAV.
The consensus nucleotide sequence of overlapping cDNA clones is shown in FIG. 1 (SEQ ID NO: 1). The length of the sequence is 15,088 basepairs, which is in good agreement with the estimated size of the genomic LV RNA.
Since the LV cDNA library was made by random priming of the reverse transcriptase reaction with calf thymus pd(N) 6 primers, no cDNA clones were obtained which started with a poly-A stretch at their 3′ end. To clone the 3′ end of the viral genome, we constructed a second cDNA library, using oligo (dT) and primer 39U183R in the reverse transcriptase reaction. Primer 39U183R is complementary to LV minus-strand RNA, which is likely present in a preparation of RNA isolated from LV-infected cells. This library was screened with virus-specific probes (nick-translated cDNA clone 119 and oligonucleotide 119R64R), resulting in the isolation of five additional cDNA clones (e.g., cDNA clone 151, FIG. 2 ). Sequencing of these cDNA clones revealed that LV contains a 3′ poly(A) tail. The length of the poly(A) tail varied between the various cDNA clones, but its maximum length was twenty nucleotides. Besides clone 25 and 155 (FIG. 2 ), four additional cDNA clones were isolated at the 5′ end of the genome, which were only two to three nucleotides shorter than the ultimate 5′ nucleotide shown in FIG. 1 (SEQ ID NO: 1). Given this finding and given the way cDNA was synthesized, we assume to be very close to the 5′ end of the sequence of LV genomic RNA.
Nearly 75% of the genomic sequence of LV encodes ORF 1A and ORF 1B. ORF 1A probably initiates at the first AUG (nucleotide position 212, FIG. 1) encountered in the LV sequence. The C-terminus of ORF 1A overlaps the putative N-terminus of ORF 1 B over a small distance of 16 nucleotides. It thus seems that translation of ORF 1B proceeds via ribosomal frameshifting, a hallmark of the mode of translation of the polymerase or replicase gene of coronaviruses (Boursnell et al., 1987; Bredenbeek et al. 1990) and the torovirus BEV (Snijder et al., 1990a). The characteristic RNA pseudoknot structure which is predicted to be formed at the site of the ribosomal frameshifting is also found at this location in the sequence of LV (results not shown).
ORF 1B encodes an amino acid sequence (SEQ ID NO: 3) of nearly 1400 residues which is much smaller than ORF 1B of the coronaviruses MHV and IBV (about 3,700 amino acid residues; Bredenbeek et al., 1990; Boursnell et al., 1987) and BEV (about 2,300 amino acid residues; Snijder et al., 1990a). Characteristic features of the ORF 1B product (SEQ ID NO: 3) of members of the superfamily of coronaviridae, like the replicase motif and the Zinc finger domain, can also be found in ORF 1B of LV (results not shown).
Whereas ORF 1A and ORF 1B encode the viral polymerase (SEQ ID NO:2 and SEQ ID NO:3) and, therefore, are considered to encode a non-structural viral protein, ORFs 2 to 7 are believed to encode structural viral proteins (SEQ ID NOS:4-9).
The products of ORFs 2 to 6 (SEQ ID NOS:4-8) all show features reminiscent of membrane (envelope) associated proteins. ORF 2 encodes a protein (SEQ ID NO:4) of 249 amino acids containing two predicted N-linked glycosylation sites (Table 9). At the N-terminus a hydrophobic sequence, which may function as a so-called signal sequence, is identified. The C-terminus also ends with a hydrophobic sequence, which in this case may function as a transmembrane region, which anchors the ORF 2 product (SEQ ID NO:4) in the viral envelope membrane.
ORF 3 may initiate at the AUG starting at nucleotide position 12394 or at the AUG starting at nucleotide position 12556 and then encodes proteins (SEQ ID NO:5) of 265 and 211 amino acids, respectively. The protein of 265 residues contains seven putative N-linked glycosylation sites, whereas the protein of 211 residues contains four (Table 9). At the N-terminus of the protein (SEQ ID NO:5) of 265 residues a hydrophobic sequence is identified.
Judged by hydrophobicity analysis, the topology of the protein encoded by ORF 4 (SEQ ID NO:6) is similar to that encoded by ORF 2 (SEQ ID NO:4) if the product of ORF 4 (SEQ ID NO:6) initiates at the AUG starting at nucleotide position 12936. However, ORF 4 may also initiate at two other AUG codons (compare FIGS. 1 and 2) starting at positions 12981 and 13068 in the sequence respectively. Up to now it is unclear which start codon is used. Depending on the start codon used, ORF 4 may encode proteins (SEQ ID NO:6) of 183 amino acids containing four putative N-linked glycosylation sites, of 168 amino acids containing four putative N-linked glycosylation sites, or of 139 amino acids containing three putative N-linked glycosylation sites (Table 9).
ORF 5 is predicted to encode a protein (SEQ ID NO:7) of 201 amino acids having two putative N-linked glycosylation sites (Table 9). A characteristic feature of the ORF 5 product (SEQ ID NO:7) is the internal hydrophobic sequence between amino acid 108 to amino acid 132.
Analysis for membrane spanning segments and hydrophilicity of the product of ORF 6 (SEQ ID NO:8) shows that it contains three transmembrane spanning segments in the N-terminal 90 amino acids of its sequence. This remarkable feature is also a characteristic of the small envelope glycoprotein M or E1 of several coronaviruses, e.g., Infectious Bronchitis Virus (IBV; Boursnell et al., 1984) and Mouse Hepatitis Virus (MHV: Rottier et al., 1986). It is, therefore, predicted that the protein encoded by ORF 6 (SEQ ID NO:8) was a membrane topology analogous to that of the M or E1 protein of coronaviruses (Rottier et al., 1986). A second characteristic of the M or E1 protein is a so-called surface helix which is located immediately adjacent to the presumed third transmembrane region. This sequence of about 25 amino acids which is very well conserved among coronaviruses is also recognized, although much more degenerate, in LV. Yet we predict the product of LV ORF 6 (SEQ ID NO:8) to have an analogous membrane associated function as the coronavirus M or E1 protein. Furthermore, the protein encoded by ORF 6 (SEQ ID NO:8) showed a strong similarity (53% identical amino acids) with VpX (Godeny et al., 1990) of LDV.
The protein encoded by ORF 7 (SEQ ID NO:9) has a length of 128 amino acid residues (Table 9) which is 13 amino acids longer than Vp1 of LDV (Godeny et al., 1990). Yet a significant similarity (43% identical amino acids) was observed between the protein encoded by ORF 7 (SEQ ID NO:9) and Vp1. Another shared characteristic between the product of ORF 7 (SEQ ID NO:9) and Vp1 is the high concentration of basic residues (Arg, Lys and His) in the N-terminal half of the protein. Up to amino acid 55, the LV sequence contains 26% Arg, Lys and His. This finding is fully in line with the proposed function of the ORF 7 product (SEQ ID NO:9) or Vp1 (Godeny et al., 1990), namely encapsidation of the viral genomic RNA. On the basis of the above data, we propose the LV ORF 7 product (SEQ ID NO:9) to be the nucleocapsid protein N of the virus.
A schematic representation of the organization of the LV genome is shown in FIG. 2 . The map of overlapping clones used to determine the sequence of LV is shown in the top panel. A linear compilation of this map indicating the 5′ and 3′ end of the nucleotide sequence of LV, shown in FIG. 1 (SEQ ID NO:1), including a division in kilobases, is shown below the map of cDNA clones and allows the positioning of these clones in the sequence. The position of the ORFs identified in the LV genome is indicated below the linear map of the LV sequence. The bottom panel shows the nested set of subgenomic mRNAs, and the position of these RNAs relative to the LV sequence.
In line with the translation strategy of coronavirus, torovirus and arterivirus subgenomic mRNAs, it is predicted that ORFs 1 to 6 are translated from the unique 5′ end of their genomic or mRNAs. This unique part of the mRNAs is considered to be that part of the RNA that is obtained when a lower molecular weight RNA is “subtracted” from the higher molecular weight RNA which is next in line. Although RNA 7 forms the 3′ end of all the other genomic and subgenomic RNAs, and thus does not have a unique region, it is believed that ORF 7 is only translated from this smallest sized mRNA. The “leader sequence” at the 5′ end of the subgenomic RNAs is indicated with a solid box. The length of this sequence is about 200 bases, but the precise site of fusion with the body of the genomic RNAs still has to be determined.
Experimental Reproduction of MSD
Eight pregnant sows were inoculated with LA and clinical signs of MSD such as inappetance and reproductive losses were reproduced in these sows. From day four to day 10-12 post-inoculation (p.i.), all sows showed a reluctance to eat. None of the sows had elevated body temperatures. Two sows had bluish ears at day 9 and 10 p.i. In Table 6 the day of birth and the number of living and dead piglets per sow is given. LA was isolated from 13 of the born piglets.
TABLE 1
Description and results of virus isolation of field samples.
A Samples of piglets suspected of infection with MSD.
number
age
farm
of pigs
days
material used
results*
RB
5
2
lung, tonsil, and brains
5 × LA
DV
4
3
lung, brains,
3 × LA
pools of kidney,
spleen
TH
3
3-5
lung, pools of kidney, tonsil
3 × LA
DO
3
10
lung, tonsil
2 × LA
ZA
4
1
lung, tonsil
3 × LA
VE
1
?
oral swab
1 × PEV 2
TOTAL
20
16 × LA,
1 × PEV 2
B Samples of sows suspected of infection with MSD.
number
farm
of sows
material used
results
TH
2
plasma and leucocytes
1 × LA
HU
5
plasma and leucocytes
2 × LA, 1 × EMCV
TS
10
plasma and leucocytes
6 × LA
HK
5
plasma and leucocytes
2 × LA
LA
6
plasma and leucocytes
2 × LA
VL
6
serum and leucocytes
5 × LA
TA
15
serum
11 × LA
LO
4
plasma and leucocytes
2 × LA
JA
8
plasma and leucocytes
8 × LA
VD
1
plasma and leucocytes
1 × LA
VW
1
serum
1 × LA
TOTAL
63
41 × LA, 1 × EMCV
*Results are given as the number of pigs from which the isolation was made. Sometimes the isolate was detected in more than one sample per pig.
LA = Lelystad Agent
PEV 2 = porcine entero virus type 2
EMCV = encephalomyocarditis virus
TABLE 2
Description and results of virus isolation of
samples of pigs with experimentally induced infections.
sow
pig@
material used
results*
A (LO) #
c 835
lung, tonsil
2 × LA
c 836
nasal swabs
2 × PEV 7
c 837
nasal swabs
B (JA)
c 825
lung, tonsil
c 821
nasal swabs
1 × PEV 7
c 823
nasal swabs
4 × PEV 7
C (JA)
c 833
lung, tonsil
1 × LA,
1 × PEV 7
c 832
nasal swabs
2 × PEV 7
c 829
nasal swabs,
plasma and
3 × LA,
leucocytes
2 × PEV 7
D (VD)
c 816
lung, tonsil
c 813
nasal swabs
1 × LA
c 815
nasal swabs
1 × PEV 7
TOTAL isolates from contact pigs
7 × LA,
13 × PEV 7
A
b 809
nasal swabs
b 817
nasal swabs
B
b 818
nasal swabs, plasma
1 × LA
and leucocytes
b 820
nasal swabs
C
b 822
nasal swabs
b 826
nasal swabs
D
b 830
nasal swabs
1 × LA
b 834
nasal swabs
TOTAL isolates from blood inoculated pigs
2 × LA
@SPF pigs were either kept in contact (c) with a sow suspected to be infected with MSD, or were given 10 ml EDTA blood (b) of that sow intramuscularly at day 0 of the experiment. Groups of one sow and three SPF pigs (c) were kept in one pen, and all four of these groups were housed in one stable. At day 6, one SPF pig in each group was killed and tonsil and lungs were used for virus isolation. The four groups of SPF pigs inoculated with blood (b) were housed in four other pens in
# a separate stable. Nasal swabs of the SPF pigs were taken at day 2, 5, 7 and 9 of the experiment, and EDTA blood for virus isolation from plasma and leucocytes was taken whenever a pig had fever.
*Results are given as number of isolates per pig.
LA = Lelystad Agent
PEV 7 = procine entero virus type 7
# In brackets the initials of the farm of origin of the sow are given.
TABLE 3
Identification of viral isolates
buoyant 1
particle 2
neutralized by 4
origin and
density
size in
sens 3 to
serum directed
cell culture
in CsCl
FM (nm)
chloroform
against (titre)
leucocytes
1.33 g/ml
28-30
not sens.
EMCV ( 1280)
sow farm HU
PK-15,
PK2, SK6
oral swab
ND
28-30
not sens.
PEV 2 (>1280)
piglet farm VE
SK6
nasal swabs,
ND
28-30
not sens.
PEV 7 (>1280)
tonsil
SPF pigs CVI
PK-15, PK2,
SK6
various
1.19 g/ml
pleomorf
sens.
none (all <5)
samples
various farms
pig lung
macrophages
1 Buoyant density in preformed linear gradients of CsCl in PBS was determined according to standard techniques (Brakke; 1967). Given is the density where the peak of infectivity was found.
2 Infected and noninfected cell cultures of the isolate under study were freeze-thawed. Cell lysates were centrifuged for 30 min at 130,000 g, the resulting pellet was negatively stained according to standard techniques (Brenner and Horne; 1959), and studied with a Philips CM 10 electron microscope. Given is the size of particles that were present in infected and not present in non-infected cultures.
3 Sensitivity to chloroform was determined according to standard techniques (Grist, Ross, and Bell; 1974).
4 Hundred to 300 TCID 50 of isolates were mixed with varying dilutions of specific antisera and grown in the appropriate cell system until full CPE was observed. Sera with titres higher than 5 were retested, and sera which blocked with high titres the CPE were considered specific for the isolate. The isolates not sensitive to chloroform were tested with sera specifically directed against porcine
# entero viruses (PEV) 1 to 11 (courtesy Dr. Knowles, Pirbright, UK), against encephalomyocarditis virus (EMCV; courtesy Dr. Ahl, Tübingen, Germany), against porcine parvo virus, and against swine vesicular disease.
The isolate (code: CDI-NL-2.91) sensitive to chloroform was tested with antisera specifically directed against pseudorabies virus, bovine herpes virus 1, bovine herpes virus 4, malignant catarrhal virus, bovine viral diarrhea virus, hog cholera virus, swine influenza virus H1N1 and H3N2, parainfluenza 3 virus, bovine respiratory syncitial virus, transmissible gastroenteritis virus, porcine epidemic diarrhoea virus, haemagglutinating encephalitis virus, infectious bronchitis virus, bovine
# leukemia virus, avian leikemia virus, maedi-visna virus, and with the experimental sera obtained from the SPF-pigs (see Table 5).
TABLE 4
Results of serology of paired field sera taken from sows
suspected to have MSD. Sera were taken
in the acute phase of the disease and 3-9 weeks
later. Given is the number of sows which showed
a fourfold or higher rise in titre/number of sows tested.
Interval i
Farm
in weeks
HAI HEV
H1N1
H3N2
ELISA PPV
PPV
BVDV
HCV
TH
3
0/6
0/6
0/6
0/6
0/6
0/5
0/6
RB
5
0/13
1/13
0/13
1/9
0/7
0/6
0/9
HU
4
0/5
0/5
3/5
0/5
0/5
0/5
0/5
TS
3
1/10
0/10
0/10
0/10
0/10
0/4
0/10
VL
3
0/5
0/5
0/5
0/5
1/5
0/5
0/5
JA
3
0/11
1/11
3/11
0/11
2/11
0/11
0/11
WE
4
1/6
1/6
1/6
3/7
3/7
0/7
0/7
GI
4
0/4
1/4
0/4
0/4
0/4
0/4
0/4
SE
5
0/8
0/8
0/8
0/8
0/6
0/3
0/8
KA
5
0/1
0/1
0/1
0/1
0/1
ND
0/1
HO
3
1/6
0/5
1/6
0/6
0/6
0/6
0/6
NY
4
0/5
1/5
1/5
0/3
0/4
0/2
0/4
JN
3
0/10
5/10
0/10
0/10
1/10
0/10
0/10
KO f
3
1/10
0/10
0/10
0/10
2/10
0/10
0/10
OE
9
ND
ND
ND
0/6
0/6
0/6
0/6
LO
6
ND
ND
ND
0/3
0/3
0/2
0/3
WI
4
ND
ND
ND
0/1
1/1
0/1
0/3
RR
3
ND
ND
ND
1/8
0/8
0/8
0/8
RY
4
ND
ND
ND
0/3
0/4
0/3
0/4
BE
5
ND
ND
ND
0/10
0/10
0/10
0/10
BU
3
ND
ND
ND
1/6
0/6
0/6
0/6
KR
3
ND
ND
ND
1/4
0/4
0/4
0/4
KW
5
ND
ND
ND
0/10
0/10
0/10
0/10
VR
5
ND
ND
ND
1/6
0/6
0/6
0/6
HU
4
ND
ND
ND
1/4
0/3
0/3
0/4
ME
3
ND
ND
ND
0/5
1/5
0/5
0/5
total negative n
19
41
29
97
16
140
165
total positive p
77
48
62
55
131
1
0
total sero-converted s
4
10
9
9
11
0
0
total tested
100
99
100
161
158
141
165
Interval
SNT
IPMA
Farm
in weeks
EMCV
EMCVi
PEV2
PEV2i
PEV7
PEV7i
LA
LA
TH
3
0/6
0/6
0/5
0/5
0/6
0/5
0/6
6/6
RB
5
1/7
1/9
0/6
2/6
1/8
0/6
0/13
7/9
HU
4
ND
0/5
0/5
0/5
ND
0/5
0/5
5/5
TS
3
0/10
0/10
0/7
0/4
0/10
0/7
ND
10/10
VL
3
ND
ND
1/5
0/5
ND
0/5
ND
5/5
JA
3
0/11
0/11
0/11
0/11
1/11
2/11
0/5
8/11
WE
4
1/7
1/6
1/6
1/7
1/7
1/7
0/7
7/7
GI
4
0/4
0/4
0/4
0/4
0/4
0/4
0/4
4/4
SE
5
0/8
0/8
0/6
1/8
0/8
1/5
0/8
6/8
KA
5
0/1
0/1
0/1
0/1
0/1
0/1
0/1
0/1
HO
3
0/6
0/6
0/6
0/6
0/6
0/6
0/6
4/6
NY
4
0/4
0/4
0/2
0/2
0/4
0/3
0/4
4/4
JN
3
0/10
0/10
1/10
0/9
0/10
0/10
0/10
5/10
KO f
3
0/10
0/10
2/10
2/10
1/10
3/10
ND
8/10
OE
9
0/6
0/6
1/6
1/5
ND
1/6
ND
4/6
LO
6
0/3
0/3
0/3
0/3
0/3
0/3
ND
3/3
WI
4
ND
ND
0/1
0/1
ND
0/1
ND
0/3
RR
3
0/8
1/8
0/8
0/8
0/8
0/8
ND
8/8
RY
4
0/4
ND
0/4
0/1
ND
1/4
ND
1/4
BE
5
ND
ND
0/10
0/10
ND
1/10
ND
0/10
BU
3
ND
ND
0/6
0/6
ND
0/6
ND
6/6
KR
3
ND
ND
0/4
0/4
ND
0/4
ND
1/4
KW
5
ND
ND
0/10
0/10
ND
1/10
ND
10/10
VR
5
ND
ND
0/6
1/6
ND
0/6
ND
6/6
HU
4
ND
ND
0/3
0/4
ND
0/3
ND
3/4
ME
3
ND
ND
0/5
0/5
ND
0/5
ND
2/5
total neg. n
15
29
0
0
2
1
69
15
total pos. p
88
74
144
138
90
136
0
27
total sero-converted s
2
3
6
8
4
10
0
123
total tested
105
107
150
146
96
147
69
165
The sera were tested in haemagglutinating inhibition (HAI) tests for the detection of antibody against haemagglutinating encephalitis virus (HEV), and swine influenza viruses H1N1 and H3N2, in enzyme-linked-immuno sorbent assays (ELISA) for the detection of antibody against the glycoprotein gI of pseudorabies virus (PRV), against porcine parvo virus (PPV), bovine viral diarrhea virus (BVDV), and hog cholera virus (HCV).
The sera were tested in serum neutralization tests (SNT) for the detection of neutralizing antibody directed against encephalomyocarditis virus (EMCV), the isolated (i) EMCV, porcine entero viruses (PEV) 2 and 7 and the PEV isolates (i), and against the Lelystad Agent (LA), and were tested in an immuno-peroxidase-monolayer-assay (IPMA) for the detection of antibody directed against the Lelystad Agent (LA).
f fattening pigs.
i time between sampling of the first and second serum.
n total number of pigs of which the first serum was negative in the test under study, and of which the second serum was also negative or showed a less than fourfold rise in titre.
p total number of pigs of which the first serum was positive and of which the second serum showed a less than fourfold rise in titre.
s total number of pigs of which the second serum had a fourfold or higher titre than the first serum in the test under study.
ND = not done.
TABLE 5
Development of antibody directed against
Lelystad Agent as measured by IPMA.
A contact pigs serum titres in IPMA
Weeks post contact:
Pig
0
2
3
4
5
c 836
0
10
640
640
640
c 837
0
10
640
640
640
c 821
0
640
640
640
640
c 823
0
160
2560
640
640
c 829
0
160
640
10240
10240
c 832
0
160
640
640
2560
c 813
0
640
2560
2560
2560
c 815
0
160
640
640
640
B blood inoculated pigs serum titres in IPMA
Weeks post inoculation:
Pig
0
2
3
4
6
b 809
0
640
2560
2560
2560
b 817
0
160
640
640
640
b 818
0
160
640
640
640
b 820
0
160
640
640
640
b 822
0
640
2560
2560
10240
b 826
0
640
640
640
10240
b 830
0
640
640
640
2560
b 834
0
160
640
2560
640
See Table 2 for description of the experiment. All pigs were bled at regular intervals and all sera were tested in an immuno-peroxidase-monolayer-assay (IPMA) for the detection of antibody directed against the Lelystad Agent (LA).
TABLE 6
Experimental reproduction of MSD.
No. of piglets
Length
at birth
No. of
LA 1 in piglets
of
alive
dead
deaths
born
died in
Sow
gestation
(Number Ab pos) 2
week 1
dead
week 1
52
113
12 (5)
3 (2)
6
2
4
965
116
3 (0)
9 (3)
2
4
997
114
9 (0)
1 (0)
0
1305
116
7 (0)
2 (0)
1
134
109
4 (4)
7 (4)
4
3
941
117
7
10
1056
113
7 (1)
3 (0)
4
1065
115
9
2
1 LA was isolated from lung, liver, spleen, kidney, or ascitic fluids.
2 Antibodies directed against LA were detected in serum samples taken before the piglets had sucked, or were detected in ascitic fluids of piglets born dead.
TABLE 7
Reactivity in IPMA of a collection of field sera from
Europe and North America tested with LA
isolates from the Netherlands (NL1 and NL2),
Germany (GE1 and GE2), and the United States
(US1, US2 and US3).
Isolates:
NL1
NL2
GE1
GE2
US1
US2
US3
Sera from:
The Netherlands
TH-187
3.5 t
3.5
2.5
3.5
−
−
−
TO-36
3.5
3.0
2.5
3.0
−
1.0
−
Germany
BE-352
4.0
3.5
2.5
3.0
−
1.5
−
BE-392
3.5
3.5
2.5
2.5
1.5
1.5
0.5
NI-f2
2.5
1.5
2.0
2.5
−
−
−
United Kingdom
PA-141615
4.0
3.0
3.0
3.5
−
−
−
PA-141617
4.0
3.5
3.0
3.5
−
2.5
2.0
PA-142440
3.5
3.0
2.5
3.5
−
2.0
2.5
Belgium
PE-1960
4.5
4.5
3.0
4.0
1.5
−
−
France
EA-2975
4.0
3.5
3.0
3.0
2.0
−
−
EA-2985
3.5
3.0
3.0
2.5
−
−
−
United States
SL-441
3.5
1.5
2.5
2.5
3.5
3.5
3.0
SL-451
3.0
2.0
2.5
2.5
3.5
4.5
4.0
AL-RP9577
1.5
−
−
1.0
3.0
4.0
2.5
AL-P10814/33
0.5
2.5
−
−
2.5
3.5
3.0
AL-4094A
−
−
−
−
1.0
2.0
0.5
AL-7525
−
−
−
−
−
1.0
−
JC-MN41
−
−
−
−
1.0
3.5
1.0
JC-MN44
−
−
−
−
2.0
3.5
2.0
JC-MN45
−
−
−
−
2.0
3.5
2.5
Canada
RB-16
2.5
−
3.0
2.0
3.0
3.5
−
RB-19
1.0
−
1.0
−
2.5
1.5
−
RB-22
1.5
−
2.0
2.5
2.5
3.5
−
RB-23
−
−
−
−
−
3.0
−
t = titre expressed as negative log;
− = negative
TABLE 8
Reactivity in IPMA of a collection of experimental sera
raised against LA and SIRSV tested with
LA isolates from the Netherlands (NL1 and NL2),
Germany (GE1 and GE2), and the United States
(US1, US2 and US3).
Isolates:
NL1
NL2
GE1
GE2
US1
US2
US3
Sera:
anti-LA:
21
14 dpi
2.5 t
2.0
2.5
3.0
1.5
2.0
1.5
28 dpi
4.0
3.5
3.5
4.0
−
2.5
1.5
42 dpi
4.0
3.5
3.0
3.5
1.5
2.5
2.0
23
14 dpi
3.0
2.0
2.5
3.0
1.0
2.0
1.0
28 dpi
3.5
3.5
3.5
4.0
1.5
2.0
2.0
42 dpi
4.0
4.0
3.0
4.0
−
2.5
2.5
25
14 dpi
2.5
2.0
2.5
3.0
1.5
2.0
1.0
28 dpi
4.0
3.5
4.0
3.5
−
1.5
2.0
42 dpi
3.5
4.0
3.5
3.5
1.5
2.0
2.0
29
14 dpi
3.5
3.5
3.0
3.5
−
2.0
1.5
28 dpi
3.5
3.5
3.0
3.5
−
2.5
2.0
42 dpi
4.0
3.5
3.5
4.0
1.5
2.5
2.5
anti-
SIRSV:
2B
20 dpi
−
−
−
−
2.0
2.0
−
36 dpi
−
−
−
−
1.5
2.0
−
63 dpi
−
−
−
−
1.0
1.0
−
9G
30 dpi
−
−
−
−
2.5
3.0
−
44 dpi
−
−
−
−
2.5
3.5
−
68 dpi
−
−
−
−
2.0
3.5
1.5
16W
25 dpi
−
−
−
−
2.0
3.0
−
40 dpi
−
−
−
−
2.0
3.0
−
64 dpi
−
−
−
−
2.5
2.5
1.5
16Y
36 dpi
−
−
−
−
1.0
3.0
1.0
64 dpi
−
−
−
−
2.5
3.0
−
t = titer expressed as negative log;
− = negative
TABLE 9
Characteristics of the ORFs of Lelystad Virus.
Calculated
No. of
size of the
number of
Nucleotides
amino
unmodified
glycosylation
ORF
(first-last)
acids
peptide (kDa)
sites
ORF1A
212-7399
2396
260.0
3 (SEQ ID NO: 2)
ORF1B
7384-11772
1463
161.8
3 (SEQ ID NO: 3)
ORF2
11786-12532
249
28.4
2 (SEQ ID NO: 4)
ORF3
12394-13188
265
30.6
7 (SEQ ID NO: 5)
12556-13188
211
24.5
4
ORF4
12936-13484
183
20.0
4 (SEQ ID NO: 6)
12981-13484
168
18.4
4
13068-13484
139
15.4
3
ORF5
13484-14086
201
22.4
2 (SEQ ID NO: 7)
ORF6
14077-14595
173
18.9
2 (SEQ ID NO: 8)
ORF7
14588-14971
128
13.8
1 (SEQ ID NO: 9)
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# SEQUENCE LISTING
(1) GENERAL INFORMATION:
(iii) NUMBER OF SEQUENCES: 9
(2) INFORMATION FOR SEQ ID NO: 1:
(i) SEQUENCE CHARACTERISTICS:
(A) LENGTH: 15108 base
#pairs
(B) TYPE: nucleic acid
(C) STRANDEDNESS: single
(D) TOPOLOGY: linear
(ii) MOLECULE TYPE: DNA (genomic)
(ix) FEATURE:
(A) NAME/KEY: CDS
(B) LOCATION: 212..7399
(D) OTHER INFORMATION:
(ix) FEATURE:
(A) NAME/KEY: CDS
(B) LOCATION: 7384..11772
(D) OTHER INFORMATION:
(ix) FEATURE:
(A) NAME/KEY: CDS
(B) LOCATION: 11786..12532
(D) OTHER INFORMATION:
(ix) FEATURE:
(A) NAME/KEY: CDS
(B) LOCATION: 12394..13188
(D) OTHER INFORMATION:
(ix) FEATURE:
(A) NAME/KEY: CDS
(B) LOCATION: 12936..13484
(D) OTHER INFORMATION:
(ix) FEATURE:
(A) NAME/KEY: CDS
(B) LOCATION: 13484..14086
(D) OTHER INFORMATION:
(ix) FEATURE:
(A) NAME/KEY: CDS
(B) LOCATION: 14077..14595
(D) OTHER INFORMATION:
(ix) FEATURE:
(A) NAME/KEY: CDS
(B) LOCATION: 14588..14971
(D) OTHER INFORMATION:
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:
#1:
GGGTATTCCC CCTACATACA CGACACTTCT AGTGTTTGTG TACCTTGGAG GC
#GTGGGTAC 60
AGCCCCGCCC CACCCCTTGG CCCCTGTTCT AGCCCAACAG GTATCCTTCT CT
#CTCGGGGC 120
GAGTGCGCCG CCTGCTGCTC CCTTGCAGCG GGAAGGACCT CCCGAGTATT TC
#CGGAGAGC 180
ACCTGCTTTA CGGGATCTCC ACCCTTTAAC C ATGTCTGGGA CGTTCTCCCG
# 231
GTGCATGTGC ACCCCGGCTG CCCGGGTATT TTGGAACGCC GGCCAAGTCT TT
#TGCACACG 291
GTGTCTCAGT GCGCGGTCTC TTCTCTCTCC AGAGCTTCAG GACACTGACC TC
#GGTGCAGT 351
TGGCTTGTTT TACAAGCCTA GGGACAAGCT TCACTGGAAA GTCCCTATCG GC
#ATCCCTCA 411
GGTGGAATGT ACTCCATCCG GGTGCTGTTG GCTCTCAGCT GTTTTCCCTT TG
#GCGCGTAT 471
GACCTCCGGC AATCACAACT TCCTCCAACG ACTTGTGAAG GTTGCTGATG TT
#TTGTACCG 531
TGACGGTTGC TTGGCACCTC GACACCTTCG TGAACTCCAA GTTTACGAGC GC
#GGCTGCAA 591
CTGGTACCCG ATCACGGGGC CCGTGCCCGG GATGGGTTTG TTTGCGAACT CC
#ATGCACGT 651
ATCCGACCAG CCGTTCCCTG GTGCCACCCA TGTGTTGACT AACTCGCCTT TG
#CCTCAACA 711
GGCTTGTCGG CAGCCGTTCT GTCCATTTGA GGAGGCTCAT TCTAGCGTGT AC
#AGGTGGAA 771
GAAATTTGTG GTTTTCACGG ACTCCTCCCT CAACGGTCGA TCTCGCATGA TG
#TGGACGCC 831
GGAATCCGAT GATTCAGCCG CCCTGGAGGT ACTACCGCCT GAGTTAGAAC GT
#CAGGTCGA 891
AATCCTCATT CGGAGTTTTC CTGCTCATCA CCCTGTCGAC CTGGCCGACT GG
#GAGCTCAC 951
TGAGTCCCCT GAGAACGGTT TTTCCTTCAA CACGTCTCAT TCTTGCGGTC AC
#CTTGTCCA 1011
GAACCCCGAC GTGTTTGATG GCAAGTGCTG GCTCTCCTGC TTTTTGGGCC AG
#TCGGTCGA 1071
AGTGCGCTGC CATGAGGAAC ATCTAGCTGA CGCCTTCGGT TACCAAACCA AG
#TGGGGCGT 1131
GCATGGTAAG TACCTCCAGC GCAGGCTTCA AGTTCGCGGC ATTCGTGCTG TA
#GTCGATCC 1191
TGATGGTCCC ATTCACGTTG AAGCGCTGTC TTGCCCCCAG TCTTGGATCA GG
#CACCTGAC 1251
TCTGGATGAT GATGTCACCC CAGGATTCGT TCGCCTGACA TCCCTTCGCA TT
#GTGCCGAA 1311
CACAGAGCCT ACCACTTCCC GGATCTTTCG GTTTGGAGCG CATAAGTGGT AT
#GGCGCTGC 1371
CGGCAAACGG GCTCGTGCTA AGCGTGCCGC TAAAAGTGAG AAGGATTCGG CT
#CCCACCCC 1431
CAAGGTTGCC CTGCCGGTCC CCACCTGTGG AATTACCACC TACTCTCCAC CG
#ACAGACGG 1491
GTCTTGTGGT TGGCATGTCC TTGCCGCCAT AATGAACCGG ATGATAAATG GT
#GACTTCAC 1551
GTCCCCTCTG ACTCAGTACA ACAGACCAGA GGATGATTGG GCTTCTGATT AT
#GATCTTGT 1611
TCAGGCGATT CAATGTCTAC GACTGCCTGC TACCGTGGTT CGGAATCGCG CC
#TGTCCTAA 1671
CGCCAAGTAC CTTATAAAAC TTAACGGAGT TCACTGGGAG GTAGAGGTGA GG
#TCTGGAAT 1731
GGCTCCTCGC TCCCTTTCTC GTGAATGTGT GGTTGGCGTT TGCTCTGAAG GC
#TGTGTCGC 1791
ACCGCCTTAT CCAGCAGACG GGCTACCTAA ACGTGCACTC GAGGCCTTGG CG
#TCTGCTTA 1851
CAGACTACCC TCCGATTGTG TTAGCTCTGG TATTGCTGAC TTTCTTGCTA AT
#CCACCTCC 1911
TCAGGAATTC TGGACCCTCG ACAAAATGTT GACCTCCCCG TCACCAGAGC GG
#TCCGGCTT 1971
CTCTAGTTTG TATAAATTAC TATTAGAGGT TGTTCCGCAA AAATGCGGTG CC
#ACGGAAGG 2031
GGCTTTCATC TATGCTGTTG AGAGGATGTT GAAGGATTGT CCGAGCTCCA AA
#CAGGCCAT 2091
GGCCCTTCTG GCAAAAATTA AAGTTCCATC CTCAAAGGCC CCGTCTGTGT CC
#CTGGACGA 2151
GTGTTTCCCT ACGGATGTTT TAGCCGACTT CGAGCCAGCA TCTCAGGAAA GG
#CCCCAAAG 2211
TTCCGGCGCT GCTGTTGTCC TGTGTTCACC GGATGCAAAA GAGTTCGAGG AA
#GCAGCCCC 2271
RGAAGAAGTT CAAGAGAGTG GCCACAAGGC CGTCCACTCT GCACTCCTTG CC
#GAGGGTCC 2331
TAACAATGAG CAGGTACAGG TGGTTGCCGG TGAGCAACTG AAGCTCGGCG GT
#TGTGGTTT 2391
GGCAGTCGGG AATGCTCATG AAGGTGCTCT GGTCTCAGCT GGTCTAATTA AC
#CTGGTAGG 2451
CGGGAATTTG TCCCCCTCAG ACCCCATGAA AGAAAACATG CTCAATAGCC GG
#GAAGACGA 2511
ACCACTGGAT TTGTCCCAAC CAGCACCAGC TTCCACAACG ACCCTTGTGA GA
#GAGCAAAC 2571
ACCCGACAAC CCAGGTTCTG ATGCCGGTGC CCTCCCCGTC ACCGTTCGAG AA
#TTTGTCCC 2631
GACGGGGCCT ATACTCTGTC ATGTTGAGCA CTGCGGCACG GAGTCGGGCG AC
#AGCAGTTC 2691
GCCTTTGGAT CTATCTGATG CGCAAACCCT GGACCAGCCT TTAAATCTAT CC
#CTGGCCGC 2751
TTGGCCAGTG AGGGCCACCG CGTCTGACCC TGGCTGGGTC CACGGTAGGC GC
#GAGCCTGT 2811
CTTTGTAAAG CCTCGAAATG CTTTCTCTGA TGGCGATTCA GCCCTTCAGT TC
#GGGGAGCT 2871
TTCTGAATCC AGCTCTGTCA TCGAGTTTGA CCGGACAAAA GATGCTCCGG TG
#GTTGACGC 2931
CCCTGTCGAC TTGACGACTT CGAACGAGGC CCTCTCTGTA GTCGATCCTT TC
#GAATTTGC 2991
CGAACTCAAG CGCCCGCGTT TCTCCGCACA AGCCTTAATT GACCGAGGCG GT
#CCACTTGC 3051
CGATGTCCAT GCAAAAATAA AGAACCGGGT ATATGAACAG TGCCTCCAAG CT
#TGTGAGCC 3111
CGGTAGTCGT GCAACCCCAG CCACCAGGGA GTGGCTCGAC AAAATGTGGG AT
#AGGGTGGA 3171
CATGAAAACT TGGCGCTGCA CCTCGCAGTT CCAAGCTGGT CGCATTCTTG CG
#TCCCTCAA 3231
ATTCCTCCCT GACATGATTC AAGACACACC GCCTCCTGTT CCCAGGAAGA AC
#CGAGCTAG 3291
TGACAATGCC GGCCTGAAGC AACTGGTGGC ACAGTGGGAT AGGAAATTGA GT
#GTGACCCC 3351
CCCCCCAAAA CCGGTTGGGC CAGTGCTTGA CCAGATCGTC CCTCCGCCTA CG
#GATATCCA 3411
GCAAGAAGAT GTCACCCCCT CCGATGGGCC ACCCCATGCG CCGGATTTTC CT
#AGTCGAGT 3471
GAGCACGGGC GGGAGTTGGA AAGGCCTTAT GCTTTCCGGC ACCCGTCTCG CG
#GGGTCTAT 3531
CAGCCAGCGC CTTATGACAT GGGTTTTTGA AGTTTTCTCC CACCTCCCAG CT
#TTTATGCT 3591
CACACTTTTC TCGCCGCGGG GCTCTATGGC TCCAGGTGAT TGGTTGTTTG CA
#GGTGTCGT 3651
TTTACTTGCT CTCTTGCTCT GTCGTTCTTA CCCGATACTC GGATGCCTTC CC
#TTATTGGG 3711
TGTCTTTTCT GGTTCTTTGC GGCGTGTTCG TCTGGGTGTT TTTGGTTCTT GG
#ATGGCTTT 3771
TGCTGTATTT TTATTCTCGA CTCCATCCAA CCCAGTCGGT TCTTCTTGTG AC
#CACGATTC 3831
GCCGGAGTGT CATGCTGAGC TTTTGGCTCT TGAGCAGCGC CAACTTTGGG AA
#CCTGTGCG 3891
CGGCCTTGTG GTCGGCCCCT CAGGCCTCTT ATGTGTCATT CTTGGCAAGT TA
#CTCGGTGG 3951
GTCACGTTAT CTCTGGCATG TTCTCCTACG TTTATGCATG CTTGCAGATT TG
#GCCCTTTC 4011
TCTTGTTTAT GTGGTGTCCC AGGGGCGTTG TCACAAGTGT TGGGGAAAGT GT
#ATAAGGAC 4071
AGCTCCTGCG GAGGTGGCTC TTAATGTATT TCCTTTCTCG CGCGCCACCC GT
#GTCTCTCT 4131
TGTATCCTTG TGTGATCGAT TCCAAACGCC AAAAGGGGTT GATCCTGTGC AC
#TTGGCAAC 4191
GGGTTGGCGC GGGTGCTGGC GTGGTGAGAG CCCCATCCAT CAACCACACC AA
#AAGCCCAT 4251
AGCTTATGCC AATTTGGATG AAAAGAAAAT GTCTGCCCAA ACGGTGGTTG CT
#GTCCCATA 4311
CGATCCCAGT CAGGCTATCA AATGCCTGAA AGTTCTGCAG GCGGGAGGGG CC
#ATCGTGGA 4371
CCAGCCTACA CCTGAGGTCG TTCGTGTGTC CGAGATCCCC TTCTCAGCCC CA
#TTTTTCCC 4431
AAAAGTTCCA GTCAACCCAG ATTGCAGGGT TGTGGTAGAT TCGGACACTT TT
#GTGGCTGC 4491
GGTTCGCTGC GGTTACTCGA CAGCACAACT GGTYCTGGGC CGGGGCAACT TT
#GCCAAGTT 4551
AAATCAGACC CCCCCCAGGA ACTCTATCTC CACCAAAACG ACTGGTGGGG CC
#TCTTACAC 4611
CCTTGCTGTG GCTCAAGTGT CTGCGTGGAC TCTTGTTCAT TTCATCCTCG GT
#CTTTGGTT 4671
CACATCACCT CAAGTGTGTG GCCGAGGAAC CGCTGACCCA TGGTGTTCAA AT
#CCTTTTTC 4731
ATATCCTACC TATGGCCCCG GAGTTGTGTG CTCCTCTCGA CTTTGTGTGT CT
#GCCGACGG 4791
GGTCACCCTG CCATTGTTCT CAGCCGTGGC ACAACTCTCC GGTAGAGAGG TG
#GGGATTTT 4851
TATTTTGGTG CTCGTCTCCT TGACTGCTTT GGCCCACCGC ATGGCTCTTA AG
#GCAGACAT 4911
GTTAGTGGTC TTTTCGGCTT TTTGTGCTTA CGCCTGGCCC ATGAGCTCCT GG
#TTAATCTG 4971
CTTCTTTCCT ATACTCTTGA AGTGGGTTAC CCTTCACCCT CTTACTATGC TT
#TGGGTGCA 5031
CTCATTCTTG GTGTTTTGTC TGCCAGCAGC CGGCATCCTC TCACTAGGGA TA
#ACTGGCCT 5091
TCTTTGGGCA ATTGGCCGCT TTACCCAGGT TGCCGGAATT ATTACACCTT AT
#GACATCCA 5151
CCAGTACACC TCTGGGCCAC GTGGTGCAGC TGCTGTGGCC ACAGCCCCAG AA
#GGCACTTA 5211
TATGGCCGCC GTCCGGAGAG CTGCTTTAAC TGGGCGAACT TTAATCTTCA CC
#CCGTCTGC 5271
AGTTGGATCC CTTCTCGAAG GTGCTTTCAG GACTCATAAA CCCTGCCTTA AC
#ACCGTGAA 5331
TGTTGTAGGC TCTTCCCTTG GTTCCGGAGG GGTTTTCACC ATTGATGGCA GA
#AGAACTGT 5391
CGTCACTGCT GCCCATGTGT TGAACGGCGA CACAGCTAGA GTCACCGGCG AC
#TCCTACAA 5451
CCGCATGCAC ACTTTCAAGA CCAATGGTGA TTATGCCTGG TCCCATGCTG AT
#GACTGGCA 5511
GGGCGTTGCC CCTGTGGTCA AGGTTGCGAA GGGGTACCGC GGTCGTGCCT AC
#TGGCAAAC 5571
ATCAACTGGT GTCGAACCCG GTATCATTGG GGAAGGGTTC GCCTTCTGTT TT
#ACTAACTG 5631
CGGCGATTCG GGGTCACCCG TCATCTCAGA ATCTGGTGAT CTTATTGGAA TC
#CACACCGG 5691
TTCAAACAAA CTTGGTTCTG GTCTTGTGAC AACCCCTGAA GGGGAGACCT GC
#ACCATCAA 5751
AGAAACCAAG CTCTCTGACC TTTCCAGACA TTTTGCAGGC CCAAGCGTTC CT
#CTTGGGGA 5811
CATTAAATTG AGTCCGGCCA TCATCCCTGA TGTAACATCC ATTCCGAGTG AC
#TTGGCATC 5871
GCTCCTAGCC TCCGTCCCTG TAGTGGAAGG CGGCCTCTCG ACCGTTCAAC TT
#TTGTGTGT 5931
CTTTTTCCTT CTCTGGCGCA TGATGGGCCA TGCCTGGACA CCCATTGTTG CC
#GTGGGCTT 5991
CTTTTTGCTG AATGAAATTC TTCCAGCAGT TTTGGTCCGA GCCGTGTTTT CT
#TTTGCACT 6051
CTTTGTGCTT GCATGGGCCA CCCCCTGGTC TGCACAGGTG TTGATGATTA GA
#CTCCTCAC 6111
GGCATCTCTC AACCGCAACA AGCTTTCTCT GGCGTTCTAC GCACTCGGGG GT
#GTCGTCGG 6171
TTTGGCAGCT GAAATCGGGA CTTTTGCTGG CAGATTGTCT GAATTGTCTC AA
#GCTCTTTC 6231
GACATACTGC TTCTTACCTA GGGTCCTTGC TATGACCAGT TGTGTTCCCA CC
#ATCATCAT 6291
TGGTGGACTC CATACCCTCG GTGTGATTCT GTGGTTRTTC AAATACCGGT GC
#CTCCACAA 6351
CATGCTGGTT GGTGATGGGA GTTTTTCAAG CGCCTTCTTC CTACGGTATT TT
#GCAGAGGG 6411
TAATCTCAGA AAAGGTGTTT CACAGTCCTG TGGCATGAAT AACGAGTCCC TA
#ACGGCTGC 6471
TTTAGCTTGC AAGTTGTCAC AGGCTGACCT TGATTTTTTG TCCAGCTTAA CG
#AACTTCAA 6531
GTGCTTTGTA TCTGCTTCAA ACATGAAAAA TGCTGCCGGC CAGTACATTG AA
#GCAGCGTA 6591
TGCCAAGGCC CTGCGCCAAG AGTTGGCCTC TCTAGTTCAG ATTGACAAAA TG
#AAAGGAGT 6651
TTTGTCCAAG CTCGAGGCCT TTGCTGAAAC AGCCACCCCG TCCCTTGACA TA
#GGTGACGT 6711
GATTGTTCTG CTTGGGCAAC ATCCTCACGG ATCCATCCTC GATATTAATG TG
#GGGACTGA 6771
AAGGAAAACT GTGTCCGTGC AAGAGACCCG GAGCCTAGGC GGCTCCAAAT TC
#AGTGTTTG 6831
TACTGTCGTG TCCAACACAC CCGTGGACGC CTTRACCGGC ATCCCACTCC AG
#ACACCAAC 6891
CCCTCTTTTT GAGAATGGTC CGCGTCATCG CAGCGAGGAA GACGATCTTA AA
#GTCGAGAG 6951
GATGAAGAAA CACTGTGTAT CCCTCGGCTT CCACAACATC AATGGCAAAG TT
#TACTGCAA 7011
AATTTGGGAC AAGTCTACCG GTGACACCTT TTACACGGAT GATTCCCGGT AC
#ACCCAAGA 7071
CCATGCTTTT CAGGACAGGT CAGCCGACTA CAGAGACAGG GACTATGAGG GT
#GTGCAAAC 7131
CACCCCCCAA CAGGGATTTG ATCCAAAGTC TGAAACCCCT GTTGGCACTG TT
#GTGATCGG 7191
CGGTATTACG TATAACAGGT ATCTGATCAA AGGTAAGGAG GTTCTGGTCC CC
#AAGCCTGA 7251
CAACTGCCTT GAAGCTGCCA AGCTGTCCCT TGAGCAAGCT CTCGCTGGGA TG
#GGCCAAAC 7311
TTGCGACCTT ACAGCTGCCG AGGTGGAAAA GCTAAAGCGC ATCATTAGTC AA
#CTCCAAGG 7371
TTTGACCACT GAACAGGCTT TAAACTGT TAGCCGCCAG CGGCTTGACC CGCT
#GTGGCC 7429
GCGGCGGCCT AGTTGTGACT GAAACGGCGG TAAAAATTAT AAAATACCAC AG
#CAGAACTT 7489
TCACCTTAGG CCCTTTAGAC CTAAAAGTCA CTTCCGAGGT GGAGGTAAAG AA
#ATCAACTG 7549
AGCAGGGCCA CGCTGTTGTG GCAAACTTAT GTTCCGGTGT CATCTTGATG AG
#ACCTCACC 7609
CACCGTCCCT TGTCGACGTT CTTCTGAAAC CCGGACTTGA CACAATACCC GG
#CATTCAAC 7669
CAGGGCATGG GGCCGGGAAT ATGGGCGTGG ACGGTTCTAT TTGGGATTTT GA
#AACCGCAC 7729
CCACAAAGGC AGAACTCGAG TTATCCAAGC AAATAATCCA AGCATGTGAA GT
#TAGGCGCG 7789
GGGACGCCCC GAACCTCCAA CTCCCTTACA AGCTCTATCC TGTTAGGGGG GA
#TCCTGAGC 7849
GGCATAAAGG CCGCCTTATC AATACCAGGT TTGGAGATTT ACCTTACAAA AC
#TCCTCAAG 7909
ACACCAAGTC CGCAATCCAC GCGGCTTGTT GCCTGCACCC CAACGGGGCC CC
#CGTGTCTG 7969
ATGGTAAATC CACACTAGGT ACCACTCTTC AACATGGTTT CGAGCTTTAT GT
#CCCTACTG 8029
TGCCCTATAG TGTCATGGAG TACCTTGATT CACGCCCTGA CACCCCTTTT AT
#GTGTACTA 8089
AACATGGCAC TTCCAAGGCT GCTGCAGAGG ACCTCCAAAA ATACGACCTA TC
#CACCCAAG 8149
GATTTGTCCT GCCTGGGGTC CTACGCCTAG TACGCAGATT CATCTTTGGC CA
#TATTGGTA 8209
AGGCGCCGCC ATTGTTCCTC CCATCAACCT ATCCCGCCAA GAACTCTATG GC
#AGGGATCA 8269
ATGGCCAGAG GTTCCCAACA AAGGACGTTC AGAGCATACC TGAAATTGAT GA
#AATGTGTG 8329
CCCGCGCTGT CAAGGAGAAT TGGCAAACTG TGACACCTTG CACCCTCAAG AA
#ACAGTACT 8389
GTTCCAAGCC CAAAACCAGG ACCATCCTGG GCACCAACAA CTTTATTGCC TT
#GGCTCACA 8449
GATCGGCGCT CAGTGGTGTC ACCCAGGCAT TCATGAAGAA GGCTTGGAAG TC
#CCCAATTG 8509
CCTTGGGGAA AAACAAATTC AAGGAGCTGC ATTGCACTGT CGCCGGCAGG TG
#TCTTGAGG 8569
CCGACTTGGC CTCCTGTGAC CGCAGCACCC CCGCCATTGT AAGATGGTTT GT
#TGCCAACC 8629
TCCTGTATGA ACTTGCAGGA TGTGAAGAGT ACTTGCCTAG CTATGTGCTT AA
#TTGCTGCC 8689
ATGACCTCGT GGCAACACAG GATGGTGCCT TCACAAAACG CGGTGGCCTG TC
#GTCCGGGG 8749
ACCCCGTCAC CAGTGTGTCC AACACCGTAT ATTCACTGGT AATTTATGCC CA
#GCACATGG 8809
TATTGTCGGC CTTGAAAATG GGTCATGAAA TTGGTCTTAA GTTCCTCGAG GA
#ACAGCTCA 8869
AGTTCGAGGA CCTCCTTGAA ATTCAGCCTA TGTTGGTATA CTCTGATGAT CT
#TGTCTTGT 8929
ACGCTGAAAG ACCCACMTTT CCCAATTACC ACTGGTGGGT CGAGCACCTT GA
#CCTGATGC 8989
TGGGTTTCAG AACGGACCCA AAGAAAACCG TCATAACTGA TAAACCCAGC TT
#CCTCGGCT 9049
GCAGAATTGA GGCAGGGCGA CAGCTAGTCC CCAATCGCGA CCGCATCCTG GC
#TGCTCTTG 9109
CATATCACAT GAAGGCGCAG AACGCCTCAG AGTATTATGC GTCTGCTGCC GC
#AATCCTGA 9169
TGGATTCATG TGCTTGCATT GACCATGACC CTGAGTGGTA TGAGGACCTC AT
#CTGCGGTA 9229
TTGCCCGGTG CGCCCGCCAG GATGGTTATA GCTTCCCAGG TCCGGCATTT TT
#CATGTCCA 9289
TGTGGGAGAA GCTGAGAAGT CATAATGAAG GGAAGAAATT CCGCCACTGC GG
#CATCTGCG 9349
ACGCCAAAGC CGACTATGCG TCCGCCTGTG GGCTTGATTT GTGTTTGTTC CA
#TTCGCACT 9409
TTCATCAACA CTGCCCYGTC ACTCTGAGCT GCGGTCACCA TGCCGGTTCA AA
#GGAATGTT 9469
CGCAGTGTCA GTCACCTGTT GGGGCTGGCA GATCCCCTCT TGATGCCGTG CT
#AAAACAAA 9529
TTCCATACAA ACCTCCTCGT ACTGTCATCA TGAAGGTGGG TAATAAAACA AC
#GGCCCTCG 9589
ATCCGGGGAG GTACCAGTCC CGTCGAGGTC TCGTTGCAGT CAAGAGGGGT AT
#TGCAGGCA 9649
ATGAAGTTGA TCTTTCTGAT GGRGACTACC AAGTGGTGCC TCTTTTGCCG AC
#TTGCAAAG 9709
ACATAAACAT GGTGAAGGTG GCTTGCAATG TACTACTCAG CAAGTTCATA GT
#AGGGCCAC 9769
CAGGTTCCGG AAAGACCACC TGGCTACTGA GTCAAGTCCA GGACGATGAT GT
#CATTTACA 9829
YACCCACCCA TCAGACTATG TTTGATATAG TCAGTGCTCT CAAAGTTTGC AG
#GTATTCCA 9889
TTCCAGGAGC CTCAGGACTC CCTTTCCCAC CACCTGCCAG GTCCGGGCCG TG
#GGTTAGGC 9949
TTATTGCCAG CGGGCACGTC CCTGGCCGAG TATCATACCT CGATGAGGCT GG
#ATATTGTA 10009
ATCATCTGGA CATTCTTAGA CTGCTTTCCA AAACACCCCT TGTGTGTTTG GG
#TGACCTTC 10069
AGCAACTTCA CCCTGTCGGC TTTGATTCCT ACTGTTATGT GTTCGATCAG AT
#GCCTCAGA 10129
AGCAGCTGAC CACTATTTAC AGATTTGGCC CTAACATCTG CGCACGCATC CA
#GCCTTGTT 10189
ACAGGGAGAA ACTTGAATCT AAGGCTAGGA ACACTAGGGT GGTTTTTACC AC
#CCGGCCTG 10249
TGGCCTTTGG TCAGGTGCTG ACACCATACC ATAAAGATCG CATCGGCTCT GC
#GATAACCA 10309
TAGATTCATC CCAGGGGGCC ACCTTTGATA TTGTGACATT GCATCTACCA TC
#GCCAAAGT 10369
CCCTAAATAA ATCCCGAGCA CTTGTAGCCA TCACTCGGGC AAGACACGGG TT
#GTTCATTT 10429
ATGACCCTCA TAACCAGCTC CAGGAGTTTT TCAACTTAAC CCCTGAGCGC AC
#TGATTGTA 10489
ACCTTGTGTT CAGCCGTGGG GATGAGCTGG TAGTTCTGAA TGCGGATAAT GC
#AGTCACAA 10549
CTGTAGCGAA GGCCCTTGAG ACAGGTCCAT CTCGATTTCG AGTATCAGAC CC
#GAGGTGCA 10609
AGTCTCTCTT AGCCGCTTGT TCGGCCAGTC TGGAAGGGAG CTGTATGCCA CT
#ACCGCAAG 10669
TGGCACATAA CCTGGGGTTT TACTTTTCCC CGGACAGTCC AACATTTGCA CC
#TCTGCCAA 10729
AAGAGTTGGC GCCACATTGG CCAGTGGTTA CCCACCAGAA TAATCGGGCG TG
#GCCTGATC 10789
GACTTGTCGC TAGTATGCGC CCAATTGATG CCCGCTACAG CAAGCCAATG GT
#CGGTGCAG 10849
GGTATGTGGT CGGGCCGTCC ACCTTTCTTG GTACTCCTGG TGTGGTGTCA TA
#CTATCTCA 10909
CACTATACAT CAGGGGTGAG CCCCAGGCCT TGCCAGAAAC ACTCGTTTCA AC
#AGGGCGTA 10969
TAGCCACAGA TTGTCGGGAG TATCTCGACG CGGCTGAGGA AGAGGCAGCA AA
#AGAACTCC 11029
CCCACGCATT CATTGGCGAT GTCAAAGGTA CCACGGTTGG GGGGTGTCAT CA
#CATTACAT 11089
CAAAATACCT ACCTAGGTCC CTGCCTAAGG ACTCTGTTGC CGTAGTTGGA GT
#AAGTTCGC 11149
CCGGCAGGGC TGCTAAAGCC GTGTGCACTC TCACCGATGT GTACCTCCCC GA
#ACTCCGGC 11209
CATATCTGCA ACCTGAGACG GCATCAAAAT GCTGGAAACT CAAATTAGAC TT
#CAGGGACG 11269
TCCGACTAAT GGTCTGGAAA GGAGCCACCG CCTATTTCCA GTTGGAAGGG CT
#TACATGGT 11329
CGGCGCTGCC CGACTATGCC AGGTTYATTC AGCTGCCCAA GGATGCCGTT GT
#ATACATTG 11389
ATCCGTGTAT AGGACCGGCA ACAGCCAACC GTAAGGTCGT GCGAACCACA GA
#CTGGCGGG 11449
CCGACCTGGC AGTGACACCG TATGATTACG GTGCCCAGAA CATTTTGACA AC
#AGCCTGGT 11509
TCGAGGACCT CGGGCCGCAG TGGAAGATTT TGGGGTTGCA GCCCTTTAGG CG
#AGCATTTG 11569
GCTTTGAAAA CACTGAGGAT TGGGCAATCC TTGCACGCCG TATGAATGAC GG
#CAAGGACT 11629
ACACTGACTA TAACTGGAAC TGTGTTCGAG AACGCCCACA CGCCATCTAC GG
#GCGTGCTC 11689
GTGACCATAC GTATCATTTT GCCCCTGGCA CAGAATTGCA GGTAGAGCTA GG
#TAAACCCC 11749
GGCTGCCGCC TGGGCAAGTG CCG TGAATTCGGG GTGATGCAAT GGGGTCACT
#G 11802
TGGAGTAAAA TCAGCCAGCT GTTCGTGGAC GCCTTCACTG AGTTCCTTGT TA
#GTGTGGTT 11862
GATATTGYCA TTTTCCTTGC CATACTGTTT GGGTTCACCG TCGCAGGATG GT
#TACTGGTC 11922
TTTCTTCTCA GAGTGGTTTG CTCCGCGCTT CTCCGTTCGC GCTCTGCCAT TC
#ACTCTCCC 11982
GAACTATCGA AGGTCCTATG AAGGCTTGTT GCCCAACTGC AGACCGGATG TC
#CCACAATT 12042
TGCAGTCAAG CACCCATTGG GYATGTTTTG GCACATGCGA GTTTCCCACT TG
#ATTGATGA 12102
GRTGGTCTCT CGTCGCATTT ACCAGACCAT GGAACATTCA GGTCAAGCGG CC
#TGGAAGCA 12162
GGTGGTTGGT GAGGCCACTC TCACGAAGCT GTCAGGGCTC GATATAGTTA CT
#CATTTCCA 12222
ACACCTGGCC GCAGTGGAGG CGGATTCTTG CCGCTTTCTC AGCTCACGAC TC
#GTGATGCT 12282
AAAAAATCTT GCCGTTGGCA ATGTGAGCCT ACAGTACAAC ACCACGTTGG AC
#CGCGTTGA 12342
GCTCATCTTC CCCACGCCAG GTACGAGGCC CAAGTTGACC GATTTCAGAC AA
#TGGCTCAT 12402
CAGTGTGCAC GCTTCCATTT TTTCCTCTGT GGCTTCATCT GTTACCTTGT TC
#ATAGTGCT 12462
TTGGCTTCGA ATTCCAGCTC TACGCTATGT TTTTGGTTTC CATTGGCCCA CG
#GCAACACA 12522
TCATTCGAGC TGACCATCAA CTACACCATA TGCATGCCCT GTTCTACCAG TC
#AAGCGGCT 12582
CGCCAAAGGC TCGAGCCCGG TCGTAACATG TGGTGCAAAA TAGGGCATGA CA
#GGTGTGAG 12642
GAGCGTGACC ATGATGAGTT GTTAATGTCC ATCCCGTCCG GGTACGACAA CC
#TCAAACTT 12702
GAGGGTTATT ATGCTTGGCT GGCTTTTTTG TCCTTTTCCT ACGCGGCCCA AT
#TCCATCCG 12762
GAGTTGTTCG GGATAGGGAA TGTGTCGCGC GTCTTCGTGG ACAAGCGACA CC
#AGTTCATT 12822
TGTGCCGAGC ATGATGGACA CAATTCAACC GTATCTACCG GACACAACAT CT
#CCGCATTA 12882
TATGCGGCAT ATTACCACCA CCAAATAGAC GGGGGCAATT GGTTCCATTT GG
#AATGGCTG 12942
CGGCCACTCT TTTCTTCCTG GCTGGTGCTC AACATATCAT GGTTTCTGAG GC
#GTTCGCCT 13002
GTAAGCCCTG TTTCTCGACG CATCTATCAG ATATTGAGAC CAACACGACC GC
#GGCTGCCG 13062
GTTTCATGGT CCTTCAGGAC ATCAATTGTT TCCGACCTCA CGGGGTCTCA GC
#AGCGCAAG 13122
AGAAAATTTC CTTCGGAAAG TCGTCCCAAT GTCGTGAAGC CGTCGGTACT CC
#CCAGTACA 13182
TCACGA TAACGGCTAA CGTGACCGAC GAATCATACT TGTACAACGC GGACCT
#GCTG 13238
ATGCTTTCTG CGTGCCTTTT CTACGCCTCA GAAATGAGCG AGAAAGGCTT CA
#AAGTCATC 13298
TTTGGGAATG TCTCTGGCGT TGTTTCTGCT TGTGTCAATT TCACAGATTA TG
#TGGCCCAT 13358
GTGACCCAAC ATACCCAGCA GCATCATCTG GTAATTGATC ACATTCGGTT GC
#TGCATTTC 13418
CTGACACCAT CTGCAATGAG GTGGGCTACA ACCATTGCTT GTTTGTTCGC CA
#TTCTCTTG 13478
GCAATA TGAGATGTTC TCACAAATTG GGGCGTTTCT TGACTCCGCA CTCTTG
#CTTC 13534
TGGTGGCTTT TTTTGCTGTG TACCGGCTTG TCCTGGTCCT TTGCCGATGG CA
#ACGGCGAC 13594
AGCTCGACAT ACCAATACAT ATATAACTTG ACGATATGCG AGCTGAATGG GA
#CCGACTGG 13654
TTGTCCAGCC ATTTTGGTTG GGCAGTCGAG ACCTTTGTGC TTTACCCGGT TG
#CCACTCAT 13714
ATCCTCTCAC TGGGTTTTCT CACAACAAGC CATTTTTTTG ACGCGCTCGG TC
#TCGGCGCT 13774
GTATCCACTG CAGGATTTGT TGGCGGGCGG TACGTACTCT GCAGCGTCTA CG
#GCGCTTGT 13834
GCTTTCGCAG CGTTCGTATG TTTTGTCATC CGTGCTGCTA AAAATTGCAT GG
#CCTGCCGC 13894
TATGCCCGTA CCCGGTTTAC CAACTTCATT GTGGACGACC GGGGGAGAGT TC
#ATCGATGG 13954
AAGTCTCCAA TAGTGGTAGA AAAATTGGGC AAAGCCGAAG TCGATGGCAA CC
#TCGTCACC 14014
ATCAAACATG TCGTCCTCGA AGGGGTTAAA GCTCAACCCT TGACGAGGAC TT
#CGGCTGAG 14074
CAATGGGAGG CC TAGACGATTT TTGCAACGAT CCTATCGCCG CACAAAAGCT
# 14126
CGTGCTAGCC TTTAGCATCA CATACACACC TATAATGATA TACGCCCTTA AG
#GTGTCACG 14186
CGGCCGACTC CTGGGGCTGT TGCACATCCT AATATTTCTG AACTGTTCCT TT
#ACATTCGG 14246
ATACATGACA TATGTGCATT TTCAATCCAC CAACCGTGTC GCACTTACCC TG
#GGGGCTGT 14306
TGTCGCCCTT CTGTGGGGTG TTTACAGCTT CACAGAGTCA TGGAAGTTTA TC
#ACTTCCAG 14366
ATGCAGATTG TGTTGCCTTG GCCGGCGATA CATTCTGGCC CCTGCCCATC AC
#GTAGAAAG 14426
TGCTGCAGGT CTCCATTCAA TCTCAGCGTC TGGTAACCGA GCATACGCTG TG
#AGAAAGCC 14486
CGGACTAACA TCAGTGAACG GCACTCTAGT ACCAGGACTT CGGAGCCTCG TG
#CTGGGCGG 14546
CAAACGAGCT GTTAAACGAG GAGTGGTTAA CCTCGTCAAG TATGGCCGG TAA
#AAACCAG 14605
AGCCAGAAGA AAAAGAAAAG TACAGCTCCG ATGGGGAATG GCCAGCCAGT CA
#ATCAACTG 14665
TGCCAGTTGC TGGGTGCAAT GATAAAGTCC CAGCGCCAGC AACCTAGGGG AG
#GACAGGCY 14725
AAAAAGAAAA AGCCTGAGAA GCCACATTTT CCCCTGGCTG CTGAAGATGA CA
#TCCGGCAC 14785
CACCTCACCC AGACTGAACG CTCCCTCTGC TTGCAATCGA TCCAGACGGC TT
#TCAATCAA 14845
GGCGCAGGAA CTGCGTCRCT TTCATCCAGC GGGAAGGTCA GTTTTCAGGT TG
#AGTTTATG 14905
CTGCCGGTTG CTCATACAGT GCGCCTGATT CGCGTGACTT CTACATCCGC CA
#GTCAGGGT 14965
GCAAGT TAATTTGACA GTCAGGTGAA TGGCCGCGAT GGCGTGTGGC CTCTGA
#GTCA 15021
CCTATTCAAT TAGGGCGATC ACATGGGGGT CATACTTAAT TCAGGCAGGA AC
#CATGTGAC 15081
CGAAATTAAA AAAAAAAAAA AAAAAAA
#
# 15108
(2) INFORMATION FOR SEQ ID NO: 2:
(i) SEQUENCE CHARACTERISTICS:
(A) LENGTH: 2396 amino
#acids
(B) TYPE: amino acid
(D) TOPOLOGY: linear
(ii) MOLECULE TYPE: protein
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:
#2:
Met Ser Gly Thr Phe Ser Arg Cys Met Cys Th
#r Pro Ala Ala Arg Val
1 5
# 10
# 15
Phe Trp Asn Ala Gly Gln Val Phe Cys Thr Ar
#g Cys Leu Ser Ala Arg
20
# 25
# 30
Ser Leu Leu Ser Pro Glu Leu Gln Asp Thr As
#p Leu Gly Ala Val Gly
35
# 40
# 45
Leu Phe Tyr Lys Pro Arg Asp Lys Leu His Tr
#p Lys Val Pro Ile Gly
50
# 55
# 60
Ile Pro Gln Val Glu Cys Thr Pro Ser Gly Cy
#s Cys Trp Leu Ser Ala
65
# 70
# 75
# 80
Val Phe Pro Leu Ala Arg Met Thr Ser Gly As
#n His Asn Phe Leu Gln
85
# 90
# 95
Arg Leu Val Lys Val Ala Asp Val Leu Tyr Ar
#g Asp Gly Cys Leu Ala
100
# 105
# 110
Pro Arg His Leu Arg Glu Leu Gln Val Tyr Gl
#u Arg Gly Cys Asn Trp
115
# 120
# 125
Tyr Pro Ile Thr Gly Pro Val Pro Gly Met Gl
#y Leu Phe Ala Asn Ser
130
# 135
# 140
Met His Val Ser Asp Gln Pro Phe Pro Gly Al
#a Thr His Val Leu Thr
145 1
#50 1
#55 1
#60
Asn Ser Pro Leu Pro Gln Gln Ala Cys Arg Gl
#n Pro Phe Cys Pro Phe
165
# 170
# 175
Glu Glu Ala His Ser Ser Val Tyr Arg Trp Ly
#s Lys Phe Val Val Phe
180
# 185
# 190
Thr Asp Ser Ser Leu Asn Gly Arg Ser Arg Me
#t Met Trp Thr Pro Glu
195
# 200
# 205
Ser Asp Asp Ser Ala Ala Leu Glu Val Leu Pr
#o Pro Glu Leu Glu Arg
210
# 215
# 220
Gln Val Glu Ile Leu Ile Arg Ser Phe Pro Al
#a His His Pro Val Asp
225 2
#30 2
#35 2
#40
Leu Ala Asp Trp Glu Leu Thr Glu Ser Pro Gl
#u Asn Gly Phe Ser Phe
245
# 250
# 255
Asn Thr Ser His Ser Cys Gly His Leu Val Gl
#n Asn Pro Asp Val Phe
260
# 265
# 270
Asp Gly Lys Cys Trp Leu Ser Cys Phe Leu Gl
#y Gln Ser Val Glu Val
275
# 280
# 285
Arg Cys His Glu Glu His Leu Ala Asp Ala Ph
#e Gly Tyr Gln Thr Lys
290
# 295
# 300
Trp Gly Val His Gly Lys Tyr Leu Gln Arg Ar
#g Leu Gln Val Arg Gly
305 3
#10 3
#15 3
#20
Ile Arg Ala Val Val Asp Pro Asp Gly Pro Il
#e His Val Glu Ala Leu
325
# 330
# 335
Ser Cys Pro Gln Ser Trp Ile Arg His Leu Th
#r Leu Asp Asp Asp Val
340
# 345
# 350
Thr Pro Gly Phe Val Arg Leu Thr Ser Leu Ar
#g Ile Val Pro Asn Thr
355
# 360
# 365
Glu Pro Thr Thr Ser Arg Ile Phe Arg Phe Gl
#y Ala His Lys Trp Tyr
370
# 375
# 380
Gly Ala Ala Gly Lys Arg Ala Arg Ala Lys Ar
#g Ala Ala Lys Ser Glu
385 3
#90 3
#95 4
#00
Lys Asp Ser Ala Pro Thr Pro Lys Val Ala Le
#u Pro Val Pro Thr Cys
405
# 410
# 415
Gly Ile Thr Thr Tyr Ser Pro Pro Thr Asp Gl
#y Ser Cys Gly Trp His
420
# 425
# 430
Val Leu Ala Ala Ile Met Asn Arg Met Ile As
#n Gly Asp Phe Thr Ser
435
# 440
# 445
Pro Leu Thr Gln Tyr Asn Arg Pro Glu Asp As
#p Trp Ala Ser Asp Tyr
450
# 455
# 460
Asp Leu Val Gln Ala Ile Gln Cys Leu Arg Le
#u Pro Ala Thr Val Val
465 4
#70 4
#75 4
#80
Arg Asn Arg Ala Cys Pro Asn Ala Lys Tyr Le
#u Ile Lys Leu Asn Gly
485
# 490
# 495
Val His Trp Glu Val Glu Val Arg Ser Gly Me
#t Ala Pro Arg Ser Leu
500
# 505
# 510
Ser Arg Glu Cys Val Val Gly Val Cys Ser Gl
#u Gly Cys Val Ala Pro
515
# 520
# 525
Pro Tyr Pro Ala Asp Gly Leu Pro Lys Arg Al
#a Leu Glu Ala Leu Ala
530
# 535
# 540
Ser Ala Tyr Arg Leu Pro Ser Asp Cys Val Se
#r Ser Gly Ile Ala Asp
545 5
#50 5
#55 5
#60
Phe Leu Ala Asn Pro Pro Pro Gln Glu Phe Tr
#p Thr Leu Asp Lys Met
565
# 570
# 575
Leu Thr Ser Pro Ser Pro Glu Arg Ser Gly Ph
#e Ser Ser Leu Tyr Lys
580
# 585
# 590
Leu Leu Leu Glu Val Val Pro Gln Lys Cys Gl
#y Ala Thr Glu Gly Ala
595
# 600
# 605
Phe Ile Tyr Ala Val Glu Arg Met Leu Lys As
#p Cys Pro Ser Ser Lys
610
# 615
# 620
Gln Ala Met Ala Leu Leu Ala Lys Ile Lys Va
#l Pro Ser Ser Lys Ala
625 6
#30 6
#35 6
#40
Pro Ser Val Ser Leu Asp Glu Cys Phe Pro Th
#r Asp Val Leu Ala Asp
645
# 650
# 655
Phe Glu Pro Ala Ser Gln Glu Arg Pro Gln Se
#r Ser Gly Ala Ala Val
660
# 665
# 670
Val Leu Cys Ser Pro Asp Ala Lys Glu Phe Gl
#u Glu Ala Ala Xaa Glu
675
# 680
# 685
Glu Val Gln Glu Ser Gly His Lys Ala Val Hi
#s Ser Ala Leu Leu Ala
690
# 695
# 700
Glu Gly Pro Asn Asn Glu Gln Val Gln Val Va
#l Ala Gly Glu Gln Leu
705 7
#10 7
#15 7
#20
Lys Leu Gly Gly Cys Gly Leu Ala Val Gly As
#n Ala His Glu Gly Ala
725
# 730
# 735
Leu Val Ser Ala Gly Leu Ile Asn Leu Val Gl
#y Gly Asn Leu Ser Pro
740
# 745
# 750
Ser Asp Pro Met Lys Glu Asn Met Leu Asn Se
#r Arg Glu Asp Glu Pro
755
# 760
# 765
Leu Asp Leu Ser Gln Pro Ala Pro Ala Ser Th
#r Thr Thr Leu Val Arg
770
# 775
# 780
Glu Gln Thr Pro Asp Asn Pro Gly Ser Asp Al
#a Gly Ala Leu Pro Val
785 7
#90 7
#95 8
#00
Thr Val Arg Glu Phe Val Pro Thr Gly Pro Il
#e Leu Cys His Val Glu
805
# 810
# 815
His Cys Gly Thr Glu Ser Gly Asp Ser Ser Se
#r Pro Leu Asp Leu Ser
820
# 825
# 830
Asp Ala Gln Thr Leu Asp Gln Pro Leu Asn Le
#u Ser Leu Ala Ala Trp
835
# 840
# 845
Pro Val Arg Ala Thr Ala Ser Asp Pro Gly Tr
#p Val His Gly Arg Arg
850
# 855
# 860
Glu Pro Val Phe Val Lys Pro Arg Asn Ala Ph
#e Ser Asp Gly Asp Ser
865 8
#70 8
#75 8
#80
Ala Leu Gln Phe Gly Glu Leu Ser Glu Ser Se
#r Ser Val Ile Glu Phe
885
# 890
# 895
Asp Arg Thr Lys Asp Ala Pro Val Val Asp Al
#a Pro Val Asp Leu Thr
900
# 905
# 910
Thr Ser Asn Glu Ala Leu Ser Val Val Asp Pr
#o Phe Glu Phe Ala Glu
915
# 920
# 925
Leu Lys Arg Pro Arg Phe Ser Ala Gln Ala Le
#u Ile Asp Arg Gly Gly
930
# 935
# 940
Pro Leu Ala Asp Val His Ala Lys Ile Lys As
#n Arg Val Tyr Glu Gln
945 9
#50 9
#55 9
#60
Cys Leu Gln Ala Cys Glu Pro Gly Ser Arg Al
#a Thr Pro Ala Thr Arg
965
# 970
# 975
Glu Trp Leu Asp Lys Met Trp Asp Arg Val As
#p Met Lys Thr Trp Arg
980
# 985
# 990
Cys Thr Ser Gln Phe Gln Ala Gly Arg Ile Le
#u Ala Ser Leu Lys Phe
995
# 1000
# 1005
Leu Pro Asp Met Ile Gln Asp Thr Pro Pro Pr
#o Val Pro Arg Lys Asn
1010
# 1015
# 1020
Arg Ala Ser Asp Asn Ala Gly Leu Lys Gln Le
#u Val Ala Gln Trp Asp
1025 1030
# 1035
# 1040
Arg Lys Leu Ser Val Thr Pro Pro Pro Lys Pr
#o Val Gly Pro Val Leu
1045
# 1050
# 1055
Asp Gln Ile Val Pro Pro Pro Thr Asp Ile Gl
#n Gln Glu Asp Val Thr
1060
# 1065
# 1070
Pro Ser Asp Gly Pro Pro His Ala Pro Asp Ph
#e Pro Ser Arg Val Ser
1075
# 1080
# 1085
Thr Gly Gly Ser Trp Lys Gly Leu Met Leu Se
#r Gly Thr Arg Leu Ala
1090
# 1095
# 1100
Gly Ser Ile Ser Gln Arg Leu Met Thr Trp Va
#l Phe Glu Val Phe Ser
1105 1110
# 1115
# 1120
His Leu Pro Ala Phe Met Leu Thr Leu Phe Se
#r Pro Arg Gly Ser Met
1125
# 1130
# 1135
Ala Pro Gly Asp Trp Leu Phe Ala Gly Val Va
#l Leu Leu Ala Leu Leu
1140
# 1145
# 1150
Leu Cys Arg Ser Tyr Pro Ile Leu Gly Cys Le
#u Pro Leu Leu Gly Val
1155
# 1160
# 1165
Phe Ser Gly Ser Leu Arg Arg Val Arg Leu Gl
#y Val Phe Gly Ser Trp
1170
# 1175
# 1180
Met Ala Phe Ala Val Phe Leu Phe Ser Thr Pr
#o Ser Asn Pro Val Gly
1185 1190
# 1195
# 1200
Ser Ser Cys Asp His Asp Ser Pro Glu Cys Hi
#s Ala Glu Leu Leu Ala
1205
# 1210
# 1215
Leu Glu Gln Arg Gln Leu Trp Glu Pro Val Ar
#g Gly Leu Val Val Gly
1220
# 1225
# 1230
Pro Ser Gly Leu Leu Cys Val Ile Leu Gly Ly
#s Leu Leu Gly Gly Ser
1235
# 1240
# 1245
Arg Tyr Leu Trp His Val Leu Leu Arg Leu Cy
#s Met Leu Ala Asp Leu
1250
# 1255
# 1260
Ala Leu Ser Leu Val Tyr Val Val Ser Gln Gl
#y Arg Cys His Lys Cys
1265 1270
# 1275
# 1280
Trp Gly Lys Cys Ile Arg Thr Ala Pro Ala Gl
#u Val Ala Leu Asn Val
1285
# 1290
# 1295
Phe Pro Phe Ser Arg Ala Thr Arg Val Ser Le
#u Val Ser Leu Cys Asp
1300
# 1305
# 1310
Arg Phe Gln Thr Pro Lys Gly Val Asp Pro Va
#l His Leu Ala Thr Gly
1315
# 1320
# 1325
Trp Arg Gly Cys Trp Arg Gly Glu Ser Pro Il
#e His Gln Pro His Gln
1330
# 1335
# 1340
Lys Pro Ile Ala Tyr Ala Asn Leu Asp Glu Ly
#s Lys Met Ser Ala Gln
1345 1350
# 1355
# 1360
Thr Val Val Ala Val Pro Tyr Asp Pro Ser Gl
#n Ala Ile Lys Cys Leu
1365
# 1370
# 1375
Lys Val Leu Gln Ala Gly Gly Ala Ile Val As
#p Gln Pro Thr Pro Glu
1380
# 1385
# 1390
Val Val Arg Val Ser Glu Ile Pro Phe Ser Al
#a Pro Phe Phe Pro Lys
1395
# 1400
# 1405
Val Pro Val Asn Pro Asp Cys Arg Val Val Va
#l Asp Ser Asp Thr Phe
1410
# 1415
# 1420
Val Ala Ala Val Arg Cys Gly Tyr Ser Thr Al
#a Gln Leu Xaa Leu Gly
1425 1430
# 1435
# 1440
Arg Gly Asn Phe Ala Lys Leu Asn Gln Thr Pr
#o Pro Arg Asn Ser Ile
1445
# 1450
# 1455
Ser Thr Lys Thr Thr Gly Gly Ala Ser Tyr Th
#r Leu Ala Val Ala Gln
1460
# 1465
# 1470
Val Ser Ala Trp Thr Leu Val His Phe Ile Le
#u Gly Leu Trp Phe Thr
1475
# 1480
# 1485
Ser Pro Gln Val Cys Gly Arg Gly Thr Ala As
#p Pro Trp Cys Ser Asn
1490
# 1495
# 1500
Pro Phe Ser Tyr Pro Thr Tyr Gly Pro Gly Va
#l Val Cys Ser Ser Arg
1505 1510
# 1515
# 1520
Leu Cys Val Ser Ala Asp Gly Val Thr Leu Pr
#o Leu Phe Ser Ala Val
1525
# 1530
# 1535
Ala Gln Leu Ser Gly Arg Glu Val Gly Ile Ph
#e Ile Leu Val Leu Val
1540
# 1545
# 1550
Ser Leu Thr Ala Leu Ala His Arg Met Ala Le
#u Lys Ala Asp Met Leu
1555
# 1560
# 1565
Val Val Phe Ser Ala Phe Cys Ala Tyr Ala Tr
#p Pro Met Ser Ser Trp
1570
# 1575
# 1580
Leu Ile Cys Phe Phe Pro Ile Leu Leu Lys Tr
#p Val Thr Leu His Pro
1585 1590
# 1595
# 1600
Leu Thr Met Leu Trp Val His Ser Phe Leu Va
#l Phe Cys Leu Pro Ala
1605
# 1610
# 1615
Ala Gly Ile Leu Ser Leu Gly Ile Thr Gly Le
#u Leu Trp Ala Ile Gly
1620
# 1625
# 1630
Arg Phe Thr Gln Val Ala Gly Ile Ile Thr Pr
#o Tyr Asp Ile His Gln
1635
# 1640
# 1645
Tyr Thr Ser Gly Pro Arg Gly Ala Ala Ala Va
#l Ala Thr Ala Pro Glu
1650
# 1655
# 1660
Gly Thr Tyr Met Ala Ala Val Arg Arg Ala Al
#a Leu Thr Gly Arg Thr
1665 1670
# 1675
# 1680
Leu Ile Phe Thr Pro Ser Ala Val Gly Ser Le
#u Leu Glu Gly Ala Phe
1685
# 1690
# 1695
Arg Thr His Lys Pro Cys Leu Asn Thr Val As
#n Val Val Gly Ser Ser
1700
# 1705
# 1710
Leu Gly Ser Gly Gly Val Phe Thr Ile Asp Gl
#y Arg Arg Thr Val Val
1715
# 1720
# 1725
Thr Ala Ala His Val Leu Asn Gly Asp Thr Al
#a Arg Val Thr Gly Asp
1730
# 1735
# 1740
Ser Tyr Asn Arg Met His Thr Phe Lys Thr As
#n Gly Asp Tyr Ala Trp
1745 1750
# 1755
# 1760
Ser His Ala Asp Asp Trp Gln Gly Val Ala Pr
#o Val Val Lys Val Ala
1765
# 1770
# 1775
Lys Gly Tyr Arg Gly Arg Ala Tyr Trp Gln Th
#r Ser Thr Gly Val Glu
1780
# 1785
# 1790
Pro Gly Ile Ile Gly Glu Gly Phe Ala Phe Cy
#s Phe Thr Asn Cys Gly
1795
# 1800
# 1805
Asp Ser Gly Ser Pro Val Ile Ser Glu Ser Gl
#y Asp Leu Ile Gly Ile
1810
# 1815
# 1820
His Thr Gly Ser Asn Lys Leu Gly Ser Gly Le
#u Val Thr Thr Pro Glu
1825 1830
# 1835
# 1840
Gly Glu Thr Cys Thr Ile Lys Glu Thr Lys Le
#u Ser Asp Leu Ser Arg
1845
# 1850
# 1855
His Phe Ala Gly Pro Ser Val Pro Leu Gly As
#p Ile Lys Leu Ser Pro
1860
# 1865
# 1870
Ala Ile Ile Pro Asp Val Thr Ser Ile Pro Se
#r Asp Leu Ala Ser Leu
1875
# 1880
# 1885
Leu Ala Ser Val Pro Val Val Glu Gly Gly Le
#u Ser Thr Val Gln Leu
1890
# 1895
# 1900
Leu Cys Val Phe Phe Leu Leu Trp Arg Met Me
#t Gly His Ala Trp Thr
1905 1910
# 1915
# 1920
Pro Ile Val Ala Val Gly Phe Phe Leu Leu As
#n Glu Ile Leu Pro Ala
1925
# 1930
# 1935
Val Leu Val Arg Ala Val Phe Ser Phe Ala Le
#u Phe Val Leu Ala Trp
1940
# 1945
# 1950
Ala Thr Pro Trp Ser Ala Gln Val Leu Met Il
#e Arg Leu Leu Thr Ala
1955
# 1960
# 1965
Ser Leu Asn Arg Asn Lys Leu Ser Leu Ala Ph
#e Tyr Ala Leu Gly Gly
1970
# 1975
# 1980
Val Val Gly Leu Ala Ala Glu Ile Gly Thr Ph
#e Ala Gly Arg Leu Ser
1985 1990
# 1995
# 2000
Glu Leu Ser Gln Ala Leu Ser Thr Tyr Cys Ph
#e Leu Pro Arg Val Leu
2005
# 2010
# 2015
Ala Met Thr Ser Cys Val Pro Thr Ile Ile Il
#e Gly Gly Leu His Thr
2020
# 2025
# 2030
Leu Gly Val Ile Leu Trp Xaa Phe Lys Tyr Ar
#g Cys Leu His Asn Met
2035
# 2040
# 2045
Leu Val Gly Asp Gly Ser Phe Ser Ser Ala Ph
#e Phe Leu Arg Tyr Phe
2050
# 2055
# 2060
Ala Glu Gly Asn Leu Arg Lys Gly Val Ser Gl
#n Ser Cys Gly Met Asn
2065 2070
# 2075
# 2080
Asn Glu Ser Leu Thr Ala Ala Leu Ala Cys Ly
#s Leu Ser Gln Ala Asp
2085
# 2090
# 2095
Leu Asp Phe Leu Ser Ser Leu Thr Asn Phe Ly
#s Cys Phe Val Ser Ala
2100
# 2105
# 2110
Ser Asn Met Lys Asn Ala Ala Gly Gln Tyr Il
#e Glu Ala Ala Tyr Ala
2115
# 2120
# 2125
Lys Ala Leu Arg Gln Glu Leu Ala Ser Leu Va
#l Gln Ile Asp Lys Met
2130
# 2135
# 2140
Lys Gly Val Leu Ser Lys Leu Glu Ala Phe Al
#a Glu Thr Ala Thr Pro
2145 2150
# 2155
# 2160
Ser Leu Asp Ile Gly Asp Val Ile Val Leu Le
#u Gly Gln His Pro His
2165
# 2170
# 2175
Gly Ser Ile Leu Asp Ile Asn Val Gly Thr Gl
#u Arg Lys Thr Val Ser
2180
# 2185
# 2190
Val Gln Glu Thr Arg Ser Leu Gly Gly Ser Ly
#s Phe Ser Val Cys Thr
2195
# 2200
# 2205
Val Val Ser Asn Thr Pro Val Asp Ala Xaa Th
#r Gly Ile Pro Leu Gln
2210
# 2215
# 2220
Thr Pro Thr Pro Leu Phe Glu Asn Gly Pro Ar
#g His Arg Ser Glu Glu
2225 2230
# 2235
# 2240
Asp Asp Leu Lys Val Glu Arg Met Lys Lys Hi
#s Cys Val Ser Leu Gly
2245
# 2250
# 2255
Phe His Asn Ile Asn Gly Lys Val Tyr Cys Ly
#s Ile Trp Asp Lys Ser
2260
# 2265
# 2270
Thr Gly Asp Thr Phe Tyr Thr Asp Asp Ser Ar
#g Tyr Thr Gln Asp His
2275
# 2280
# 2285
Ala Phe Gln Asp Arg Ser Ala Asp Tyr Arg As
#p Arg Asp Tyr Glu Gly
2290
# 2295
# 2300
Val Gln Thr Thr Pro Gln Gln Gly Phe Asp Pr
#o Lys Ser Glu Thr Pro
2305 2310
# 2315
# 2320
Val Gly Thr Val Val Ile Gly Gly Ile Thr Ty
#r Asn Arg Tyr Leu Ile
2325
# 2330
# 2335
Lys Gly Lys Glu Val Leu Val Pro Lys Pro As
#p Asn Cys Leu Glu Ala
2340
# 2345
# 2350
Ala Lys Leu Ser Leu Glu Gln Ala Leu Ala Gl
#y Met Gly Gln Thr Cys
2355
# 2360
# 2365
Asp Leu Thr Ala Ala Glu Val Glu Lys Leu Ly
#s Arg Ile Ile Ser Gln
2370
# 2375
# 2380
Leu Gln Gly Leu Thr Thr Glu Gln Ala Leu As
#n Cys
2385 2390
# 2395
(2) INFORMATION FOR SEQ ID NO: 3:
(i) SEQUENCE CHARACTERISTICS:
(A) LENGTH: 1463 amino
#acids
(B) TYPE: amino acid
(D) TOPOLOGY: linear
(ii) MOLECULE TYPE: protein
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:
#3:
Thr Gly Phe Lys Leu Leu Ala Ala Ser Gly Le
#u Thr Arg Cys Gly Arg
1 5
# 10
# 15
Gly Gly Leu Val Val Thr Glu Thr Ala Val Ly
#s Ile Ile Lys Tyr His
20
# 25
# 30
Ser Arg Thr Phe Thr Leu Gly Pro Leu Asp Le
#u Lys Val Thr Ser Glu
35
# 40
# 45
Val Glu Val Lys Lys Ser Thr Glu Gln Gly Hi
#s Ala Val Val Ala Asn
50
# 55
# 60
Leu Cys Ser Gly Val Ile Leu Met Arg Pro Hi
#s Pro Pro Ser Leu Val
65
# 70
# 75
# 80
Asp Val Leu Leu Lys Pro Gly Leu Asp Thr Il
#e Pro Gly Ile Gln Pro
85
# 90
# 95
Gly His Gly Ala Gly Asn Met Gly Val Asp Gl
#y Ser Ile Trp Asp Phe
100
# 105
# 110
Glu Thr Ala Pro Thr Lys Ala Glu Leu Glu Le
#u Ser Lys Gln Ile Ile
115
# 120
# 125
Gln Ala Cys Glu Val Arg Arg Gly Asp Ala Pr
#o Asn Leu Gln Leu Pro
130
# 135
# 140
Tyr Lys Leu Tyr Pro Val Arg Gly Asp Pro Gl
#u Arg His Lys Gly Arg
145 1
#50 1
#55 1
#60
Leu Ile Asn Thr Arg Phe Gly Asp Leu Pro Ty
#r Lys Thr Pro Gln Asp
165
# 170
# 175
Thr Lys Ser Ala Ile His Ala Ala Cys Cys Le
#u His Pro Asn Gly Ala
180
# 185
# 190
Pro Val Ser Asp Gly Lys Ser Thr Leu Gly Th
#r Thr Leu Gln His Gly
195
# 200
# 205
Phe Glu Leu Tyr Val Pro Thr Val Pro Tyr Se
#r Val Met Glu Tyr Leu
210
# 215
# 220
Asp Ser Arg Pro Asp Thr Pro Phe Met Cys Th
#r Lys His Gly Thr Ser
225 2
#30 2
#35 2
#40
Lys Ala Ala Ala Glu Asp Leu Gln Lys Tyr As
#p Leu Ser Thr Gln Gly
245
# 250
# 255
Phe Val Leu Pro Gly Val Leu Arg Leu Val Ar
#g Arg Phe Ile Phe Gly
260
# 265
# 270
His Ile Gly Lys Ala Pro Pro Leu Phe Leu Pr
#o Ser Thr Tyr Pro Ala
275
# 280
# 285
Lys Asn Ser Met Ala Gly Ile Asn Gly Gln Ar
#g Phe Pro Thr Lys Asp
290
# 295
# 300
Val Gln Ser Ile Pro Glu Ile Asp Glu Met Cy
#s Ala Arg Ala Val Lys
305 3
#10 3
#15 3
#20
Glu Asn Trp Gln Thr Val Thr Pro Cys Thr Le
#u Lys Lys Gln Tyr Cys
325
# 330
# 335
Ser Lys Pro Lys Thr Arg Thr Ile Leu Gly Th
#r Asn Asn Phe Ile Ala
340
# 345
# 350
Leu Ala His Arg Ser Ala Leu Ser Gly Val Th
#r Gln Ala Phe Met Lys
355
# 360
# 365
Lys Ala Trp Lys Ser Pro Ile Ala Leu Gly Ly
#s Asn Lys Phe Lys Glu
370
# 375
# 380
Leu His Cys Thr Val Ala Gly Arg Cys Leu Gl
#u Ala Asp Leu Ala Ser
385 3
#90 3
#95 4
#00
Cys Asp Arg Ser Thr Pro Ala Ile Val Arg Tr
#p Phe Val Ala Asn Leu
405
# 410
# 415
Leu Tyr Glu Leu Ala Gly Cys Glu Glu Tyr Le
#u Pro Ser Tyr Val Leu
420
# 425
# 430
Asn Cys Cys His Asp Leu Val Ala Thr Gln As
#p Gly Ala Phe Thr Lys
435
# 440
# 445
Arg Gly Gly Leu Ser Ser Gly Asp Pro Val Th
#r Ser Val Ser Asn Thr
450
# 455
# 460
Val Tyr Ser Leu Val Ile Tyr Ala Gln His Me
#t Val Leu Ser Ala Leu
465 4
#70 4
#75 4
#80
Lys Met Gly His Glu Ile Gly Leu Lys Phe Le
#u Glu Glu Gln Leu Lys
485
# 490
# 495
Phe Glu Asp Leu Leu Glu Ile Gln Pro Met Le
#u Val Tyr Ser Asp Asp
500
# 505
# 510
Leu Val Leu Tyr Ala Glu Arg Pro Xaa Phe Pr
#o Asn Tyr His Trp Trp
515
# 520
# 525
Val Glu His Leu Asp Leu Met Leu Gly Phe Ar
#g Thr Asp Pro Lys Lys
530
# 535
# 540
Thr Val Ile Thr Asp Lys Pro Ser Phe Leu Gl
#y Cys Arg Ile Glu Ala
545 5
#50 5
#55 5
#60
Gly Arg Gln Leu Val Pro Asn Arg Asp Arg Il
#e Leu Ala Ala Leu Ala
565
# 570
# 575
Tyr His Met Lys Ala Gln Asn Ala Ser Glu Ty
#r Tyr Ala Ser Ala Ala
580
# 585
# 590
Ala Ile Leu Met Asp Ser Cys Ala Cys Ile As
#p His Asp Pro Glu Trp
595
# 600
# 605
Tyr Glu Asp Leu Ile Cys Gly Ile Ala Arg Cy
#s Ala Arg Gln Asp Gly
610
# 615
# 620
Tyr Ser Phe Pro Gly Pro Ala Phe Phe Met Se
#r Met Trp Glu Lys Leu
625 6
#30 6
#35 6
#40
Arg Ser His Asn Glu Gly Lys Lys Phe Arg Hi
#s Cys Gly Ile Cys Asp
645
# 650
# 655
Ala Lys Ala Asp Tyr Ala Ser Ala Cys Gly Le
#u Asp Leu Cys Leu Phe
660
# 665
# 670
His Ser His Phe His Gln His Cys Xaa Val Th
#r Leu Ser Cys Gly His
675
# 680
# 685
His Ala Gly Ser Lys Glu Cys Ser Gln Cys Gl
#n Ser Pro Val Gly Ala
690
# 695
# 700
Gly Arg Ser Pro Leu Asp Ala Val Leu Lys Gl
#n Ile Pro Tyr Lys Pro
705 7
#10 7
#15 7
#20
Pro Arg Thr Val Ile Met Lys Val Gly Asn Ly
#s Thr Thr Ala Leu Asp
725
# 730
# 735
Pro Gly Arg Tyr Gln Ser Arg Arg Gly Leu Va
#l Ala Val Lys Arg Gly
740
# 745
# 750
Ile Ala Gly Asn Glu Val Asp Leu Ser Asp Xa
#a Asp Tyr Gln Val Val
755
# 760
# 765
Pro Leu Leu Pro Thr Cys Lys Asp Ile Asn Me
#t Val Lys Val Ala Cys
770
# 775
# 780
Asn Val Leu Leu Ser Lys Phe Ile Val Gly Pr
#o Pro Gly Ser Gly Lys
785 7
#90 7
#95 8
#00
Thr Thr Trp Leu Leu Ser Gln Val Gln Asp As
#p Asp Val Ile Tyr Xaa
805
# 810
# 815
Pro Thr His Gln Thr Met Phe Asp Ile Val Se
#r Ala Leu Lys Val Cys
820
# 825
# 830
Arg Tyr Ser Ile Pro Gly Ala Ser Gly Leu Pr
#o Phe Pro Pro Pro Ala
835
# 840
# 845
Arg Ser Gly Pro Trp Val Arg Leu Ile Ala Se
#r Gly His Val Pro Gly
850
# 855
# 860
Arg Val Ser Tyr Leu Asp Glu Ala Gly Tyr Cy
#s Asn His Leu Asp Ile
865 8
#70 8
#75 8
#80
Leu Arg Leu Leu Ser Lys Thr Pro Leu Val Cy
#s Leu Gly Asp Leu Gln
885
# 890
# 895
Gln Leu His Pro Val Gly Phe Asp Ser Tyr Cy
#s Tyr Val Phe Asp Gln
900
# 905
# 910
Met Pro Gln Lys Gln Leu Thr Thr Ile Tyr Ar
#g Phe Gly Pro Asn Ile
915
# 920
# 925
Cys Ala Arg Ile Gln Pro Cys Tyr Arg Glu Ly
#s Leu Glu Ser Lys Ala
930
# 935
# 940
Arg Asn Thr Arg Val Val Phe Thr Thr Arg Pr
#o Val Ala Phe Gly Gln
945 9
#50 9
#55 9
#60
Val Leu Thr Pro Tyr His Lys Asp Arg Ile Gl
#y Ser Ala Ile Thr Ile
965
# 970
# 975
Asp Ser Ser Gln Gly Ala Thr Phe Asp Ile Va
#l Thr Leu His Leu Pro
980
# 985
# 990
Ser Pro Lys Ser Leu Asn Lys Ser Arg Ala Le
#u Val Ala Ile Thr Arg
995
# 1000
# 1005
Ala Arg His Gly Leu Phe Ile Tyr Asp Pro Hi
#s Asn Gln Leu Gln Glu
1010
# 1015
# 1020
Phe Phe Asn Leu Thr Pro Glu Arg Thr Asp Cy
#s Asn Leu Val Phe Ser
1025 1030
# 1035
# 1040
Arg Gly Asp Glu Leu Val Val Leu Asn Ala As
#p Asn Ala Val Thr Thr
1045
# 1050
# 1055
Val Ala Lys Ala Leu Glu Thr Gly Pro Ser Ar
#g Phe Arg Val Ser Asp
1060
# 1065
# 1070
Pro Arg Cys Lys Ser Leu Leu Ala Ala Cys Se
#r Ala Ser Leu Glu Gly
1075
# 1080
# 1085
Ser Cys Met Pro Leu Pro Gln Val Ala His As
#n Leu Gly Phe Tyr Phe
1090
# 1095
# 1100
Ser Pro Asp Ser Pro Thr Phe Ala Pro Leu Pr
#o Lys Glu Leu Ala Pro
1105 1110
# 1115
# 1120
His Trp Pro Val Val Thr His Gln Asn Asn Ar
#g Ala Trp Pro Asp Arg
1125
# 1130
# 1135
Leu Val Ala Ser Met Arg Pro Ile Asp Ala Ar
#g Tyr Ser Lys Pro Met
1140
# 1145
# 1150
Val Gly Ala Gly Tyr Val Val Gly Pro Ser Th
#r Phe Leu Gly Thr Pro
1155
# 1160
# 1165
Gly Val Val Ser Tyr Tyr Leu Thr Leu Tyr Il
#e Arg Gly Glu Pro Gln
1170
# 1175
# 1180
Ala Leu Pro Glu Thr Leu Val Ser Thr Gly Ar
#g Ile Ala Thr Asp Cys
1185 1190
# 1195
# 1200
Arg Glu Tyr Leu Asp Ala Ala Glu Glu Glu Al
#a Ala Lys Glu Leu Pro
1205
# 1210
# 1215
His Ala Phe Ile Gly Asp Val Lys Gly Thr Th
#r Val Gly Gly Cys His
1220
# 1225
# 1230
His Ile Thr Ser Lys Tyr Leu Pro Arg Ser Le
#u Pro Lys Asp Ser Val
1235
# 1240
# 1245
Ala Val Val Gly Val Ser Ser Pro Gly Arg Al
#a Ala Lys Ala Val Cys
1250
# 1255
# 1260
Thr Leu Thr Asp Val Tyr Leu Pro Glu Leu Ar
#g Pro Tyr Leu Gln Pro
1265 1270
# 1275
# 1280
Glu Thr Ala Ser Lys Cys Trp Lys Leu Lys Le
#u Asp Phe Arg Asp Val
1285
# 1290
# 1295
Arg Leu Met Val Trp Lys Gly Ala Thr Ala Ty
#r Phe Gln Leu Glu Gly
1300
# 1305
# 1310
Leu Thr Trp Ser Ala Leu Pro Asp Tyr Ala Ar
#g Xaa Ile Gln Leu Pro
1315
# 1320
# 1325
Lys Asp Ala Val Val Tyr Ile Asp Pro Cys Il
#e Gly Pro Ala Thr Ala
1330
# 1335
# 1340
Asn Arg Lys Val Val Arg Thr Thr Asp Trp Ar
#g Ala Asp Leu Ala Val
1345 1350
# 1355
# 1360
Thr Pro Tyr Asp Tyr Gly Ala Gln Asn Ile Le
#u Thr Thr Ala Trp Phe
1365
# 1370
# 1375
Glu Asp Leu Gly Pro Gln Trp Lys Ile Leu Gl
#y Leu Gln Pro Phe Arg
1380
# 1385
# 1390
Arg Ala Phe Gly Phe Glu Asn Thr Glu Asp Tr
#p Ala Ile Leu Ala Arg
1395
# 1400
# 1405
Arg Met Asn Asp Gly Lys Asp Tyr Thr Asp Ty
#r Asn Trp Asn Cys Val
1410
# 1415
# 1420
Arg Glu Arg Pro His Ala Ile Tyr Gly Arg Al
#a Arg Asp His Thr Tyr
1425 1430
# 1435
# 1440
His Phe Ala Pro Gly Thr Glu Leu Gln Val Gl
#u Leu Gly Lys Pro Arg
1445
# 1450
# 1455
Leu Pro Pro Gly Gln Val Pro
1460
(2) INFORMATION FOR SEQ ID NO: 4:
(i) SEQUENCE CHARACTERISTICS:
(A) LENGTH: 249 amino
#acids
(B) TYPE: amino acid
(D) TOPOLOGY: linear
(ii) MOLECULE TYPE: protein
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:
#4:
Met Gln Trp Gly His Cys Gly Val Lys Ser Al
#a Ser Cys Ser Trp Thr
1 5
# 10
# 15
Pro Ser Leu Ser Ser Leu Leu Val Trp Leu Il
#e Leu Xaa Phe Ser Leu
20
# 25
# 30
Pro Tyr Cys Leu Gly Ser Pro Ser Gln Asp Gl
#y Tyr Trp Ser Phe Phe
35
# 40
# 45
Ser Glu Trp Phe Ala Pro Arg Phe Ser Val Ar
#g Ala Leu Pro Phe Thr
50
# 55
# 60
Leu Pro Asn Tyr Arg Arg Ser Tyr Glu Gly Le
#u Leu Pro Asn Cys Arg
65
# 70
# 75
# 80
Pro Asp Val Pro Gln Phe Ala Val Lys His Pr
#o Leu Xaa Met Phe Trp
85
# 90
# 95
His Met Arg Val Ser His Leu Ile Asp Glu Xa
#a Val Ser Arg Arg Ile
100
# 105
# 110
Tyr Gln Thr Met Glu His Ser Gly Gln Ala Al
#a Trp Lys Gln Val Val
115
# 120
# 125
Gly Glu Ala Thr Leu Thr Lys Leu Ser Gly Le
#u Asp Ile Val Thr His
130
# 135
# 140
Phe Gln His Leu Ala Ala Val Glu Ala Asp Se
#r Cys Arg Phe Leu Ser
145 1
#50 1
#55 1
#60
Ser Arg Leu Val Met Leu Lys Asn Leu Ala Va
#l Gly Asn Val Ser Leu
165
# 170
# 175
Gln Tyr Asn Thr Thr Leu Asp Arg Val Glu Le
#u Ile Phe Pro Thr Pro
180
# 185
# 190
Gly Thr Arg Pro Lys Leu Thr Asp Phe Arg Gl
#n Trp Leu Ile Ser Val
195
# 200
# 205
His Ala Ser Ile Phe Ser Ser Val Ala Ser Se
#r Val Thr Leu Phe Ile
210
# 215
# 220
Val Leu Trp Leu Arg Ile Pro Ala Leu Arg Ty
#r Val Phe Gly Phe His
225 2
#30 2
#35 2
#40
Trp Pro Thr Ala Thr His His Ser Ser
245
(2) INFORMATION FOR SEQ ID NO: 5:
(i) SEQUENCE CHARACTERISTICS:
(A) LENGTH: 265 amino
#acids
(B) TYPE: amino acid
(D) TOPOLOGY: linear
(ii) MOLECULE TYPE: protein
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:
#5:
Met Ala His Gln Cys Ala Arg Phe His Phe Ph
#e Leu Cys Gly Phe Ile
1 5
# 10
# 15
Cys Tyr Leu Val His Ser Ala Leu Ala Ser As
#n Ser Ser Ser Thr Leu
20
# 25
# 30
Cys Phe Trp Phe Pro Leu Ala His Gly Asn Th
#r Ser Phe Glu Leu Thr
35
# 40
# 45
Ile Asn Tyr Thr Ile Cys Met Pro Cys Ser Th
#r Ser Gln Ala Ala Arg
50
# 55
# 60
Gln Arg Leu Glu Pro Gly Arg Asn Met Trp Cy
#s Lys Ile Gly His Asp
65
# 70
# 75
# 80
Arg Cys Glu Glu Arg Asp His Asp Glu Leu Le
#u Met Ser Ile Pro Ser
85
# 90
# 95
Gly Tyr Asp Asn Leu Lys Leu Glu Gly Tyr Ty
#r Ala Trp Leu Ala Phe
100
# 105
# 110
Leu Ser Phe Ser Tyr Ala Ala Gln Phe His Pr
#o Glu Leu Phe Gly Ile
115
# 120
# 125
Gly Asn Val Ser Arg Val Phe Val Asp Lys Ar
#g His Gln Phe Ile Cys
130
# 135
# 140
Ala Glu His Asp Gly His Asn Ser Thr Val Se
#r Thr Gly His Asn Ile
145 1
#50 1
#55 1
#60
Ser Ala Leu Tyr Ala Ala Tyr Tyr His His Gl
#n Ile Asp Gly Gly Asn
165
# 170
# 175
Trp Phe His Leu Glu Trp Leu Arg Pro Leu Ph
#e Ser Ser Trp Leu Val
180
# 185
# 190
Leu Asn Ile Ser Trp Phe Leu Arg Arg Ser Pr
#o Val Ser Pro Val Ser
195
# 200
# 205
Arg Arg Ile Tyr Gln Ile Leu Arg Pro Thr Ar
#g Pro Arg Leu Pro Val
210
# 215
# 220
Ser Trp Ser Phe Arg Thr Ser Ile Val Ser As
#p Leu Thr Gly Ser Gln
225 2
#30 2
#35 2
#40
Gln Arg Lys Arg Lys Phe Pro Ser Glu Ser Ar
#g Pro Asn Val Val Lys
245
# 250
# 255
Pro Ser Val Leu Pro Ser Thr Ser Arg
260
# 265
(2) INFORMATION FOR SEQ ID NO: 6:
(i) SEQUENCE CHARACTERISTICS:
(A) LENGTH: 183 amino
#acids
(B) TYPE: amino acid
(D) TOPOLOGY: linear
(ii) MOLECULE TYPE: protein
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:
#6:
Met Ala Ala Ala Thr Leu Phe Phe Leu Ala Gl
#y Ala Gln His Ile Met
1 5
# 10
# 15
Val Ser Glu Ala Phe Ala Cys Lys Pro Cys Ph
#e Ser Thr His Leu Ser
20
# 25
# 30
Asp Ile Glu Thr Asn Thr Thr Ala Ala Ala Gl
#y Phe Met Val Leu Gln
35
# 40
# 45
Asp Ile Asn Cys Phe Arg Pro His Gly Val Se
#r Ala Ala Gln Glu Lys
50
# 55
# 60
Ile Ser Phe Gly Lys Ser Ser Gln Cys Arg Gl
#u Ala Val Gly Thr Pro
65
# 70
# 75
# 80
Gln Tyr Ile Thr Ile Thr Ala Asn Val Thr As
#p Glu Ser Tyr Leu Tyr
85
# 90
# 95
Asn Ala Asp Leu Leu Met Leu Ser Ala Cys Le
#u Phe Tyr Ala Ser Glu
100
# 105
# 110
Met Ser Glu Lys Gly Phe Lys Val Ile Phe Gl
#y Asn Val Ser Gly Val
115
# 120
# 125
Val Ser Ala Cys Val Asn Phe Thr Asp Tyr Va
#l Ala His Val Thr Gln
130
# 135
# 140
His Thr Gln Gln His His Leu Val Ile Asp Hi
#s Ile Arg Leu Leu His
145 1
#50 1
#55 1
#60
Phe Leu Thr Pro Ser Ala Met Arg Trp Ala Th
#r Thr Ile Ala Cys Leu
165
# 170
# 175
Phe Ala Ile Leu Leu Ala Ile
180
(2) INFORMATION FOR SEQ ID NO: 7:
(i) SEQUENCE CHARACTERISTICS:
(A) LENGTH: 201 amino
#acids
(B) TYPE: amino acid
(D) TOPOLOGY: linear
(ii) MOLECULE TYPE: protein
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:
#7:
Met Arg Cys Ser His Lys Leu Gly Arg Phe Le
#u Thr Pro His Ser Cys
1 5
# 10
# 15
Phe Trp Trp Leu Phe Leu Leu Cys Thr Gly Le
#u Ser Trp Ser Phe Ala
20
# 25
# 30
Asp Gly Asn Gly Asp Ser Ser Thr Tyr Gln Ty
#r Ile Tyr Asn Leu Thr
35
# 40
# 45
Ile Cys Glu Leu Asn Gly Thr Asp Trp Leu Se
#r Ser His Phe Gly Trp
50
# 55
# 60
Ala Val Glu Thr Phe Val Leu Tyr Pro Val Al
#a Thr His Ile Leu Ser
65
# 70
# 75
# 80
Leu Gly Phe Leu Thr Thr Ser His Phe Phe As
#p Ala Leu Gly Leu Gly
85
# 90
# 95
Ala Val Ser Thr Ala Gly Phe Val Gly Gly Ar
#g Tyr Val Leu Cys Ser
100
# 105
# 110
Val Tyr Gly Ala Cys Ala Phe Ala Ala Phe Va
#l Cys Phe Val Ile Arg
115
# 120
# 125
Ala Ala Lys Asn Cys Met Ala Cys Arg Tyr Al
#a Arg Thr Arg Phe Thr
130
# 135
# 140
Asn Phe Ile Val Asp Asp Arg Gly Arg Val Hi
#s Arg Trp Lys Ser Pro
145 1
#50 1
#55 1
#60
Ile Val Val Glu Lys Leu Gly Lys Ala Glu Va
#l Asp Gly Asn Leu Val
165
# 170
# 175
Thr Ile Lys His Val Val Leu Glu Gly Val Ly
#s Ala Gln Pro Leu Thr
180
# 185
# 190
Arg Thr Ser Ala Glu Gln Trp Glu Ala
195
# 200
(2) INFORMATION FOR SEQ ID NO: 8:
(i) SEQUENCE CHARACTERISTICS:
(A) LENGTH: 173 amino
#acids
(B) TYPE: amino acid
(D) TOPOLOGY: linear
(ii) MOLECULE TYPE: protein
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:
#8:
Met Gly Gly Leu Asp Asp Phe Cys Asn Asp Pr
#o Ile Ala Ala Gln Lys
1 5
# 10
# 15
Leu Val Leu Ala Phe Ser Ile Thr Tyr Thr Pr
#o Ile Met Ile Tyr Ala
20
# 25
# 30
Leu Lys Val Ser Arg Gly Arg Leu Leu Gly Le
#u Leu His Ile Leu Ile
35
# 40
# 45
Phe Leu Asn Cys Ser Phe Thr Phe Gly Tyr Me
#t Thr Tyr Val His Phe
50
# 55
# 60
Gln Ser Thr Asn Arg Val Ala Leu Thr Leu Gl
#y Ala Val Val Ala Leu
65
# 70
# 75
# 80
Leu Trp Gly Val Tyr Ser Phe Thr Glu Ser Tr
#p Lys Phe Ile Thr Ser
85
# 90
# 95
Arg Cys Arg Leu Cys Cys Leu Gly Arg Arg Ty
#r Ile Leu Ala Pro Ala
100
# 105
# 110
His His Val Glu Ser Ala Ala Gly Leu His Se
#r Ile Ser Ala Ser Gly
115
# 120
# 125
Asn Arg Ala Tyr Ala Val Arg Lys Pro Gly Le
#u Thr Ser Val Asn Gly
130
# 135
# 140
Thr Leu Val Pro Gly Leu Arg Ser Leu Val Le
#u Gly Gly Lys Arg Ala
145 1
#50 1
#55 1
#60
Val Lys Arg Gly Val Val Asn Leu Val Lys Ty
#r Gly Arg
165
# 170
(2) INFORMATION FOR SEQ ID NO: 9:
(i) SEQUENCE CHARACTERISTICS:
(A) LENGTH: 128 amino
#acids
(B) TYPE: amino acid
(D) TOPOLOGY: linear
(ii) MOLECULE TYPE: protein
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:
#9:
Met Ala Gly Lys Asn Gln Ser Gln Lys Lys Ly
#s Lys Ser Thr Ala Pro
1 5
# 10
# 15
Met Gly Asn Gly Gln Pro Val Asn Gln Leu Cy
#s Gln Leu Leu Gly Ala
20
# 25
# 30
Met Ile Lys Ser Gln Arg Gln Gln Pro Arg Gl
#y Gly Gln Xaa Lys Lys
35
# 40
# 45
Lys Lys Pro Glu Lys Pro His Phe Pro Leu Al
#a Ala Glu Asp Asp Ile
50
# 55
# 60
Arg His His Leu Thr Gln Thr Glu Arg Ser Le
#u Cys Leu Gln Ser Ile
65
# 70
# 75
# 80
Gln Thr Ala Phe Asn Gln Gly Ala Gly Thr Al
#a Xaa Leu Ser Ser Ser
85
# 90
# 95
Gly Lys Val Ser Phe Gln Val Glu Phe Met Le
#u Pro Val Ala His Thr
100
# 105
# 110
Val Arg Leu Ile Arg Val Thr Ser Thr Ser Al
#a Ser Gln Gly Ala Ser
115
# 120
# 125
|
Composition of matter comprising the causative agent of Mystery Swine Disease, Lelystad Agent, in a live, attenuated, dead, or recombinant form, or a part or component of it. Vaccine compositions and diagnostic kits based thereon. Recombinant nucleic acid comprising a Lelystad Agent-specific nucleotide sequence. Peptides comprising a Lelystad Agent-specific amino acid sequence. Lelystad Agent-specific antibodies.
| 8
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a device for forming at least one thin film made of a powder material, used during the action of a laser on said material, and a method for forming thin films using this device.
2. Brief Discussion of the Related Art
Such a device is used during a method, known as laser sintering or laser fusion, for the sintering or fusion of a powder material, using a laser, in a thermal chamber. The term powder material refers to a powder or powder mixture, said powder(s) optionally being metallic, organic or ceramic. Hereinafter, the terms powder or powder material will be used.
FR-A-2 856 614 discloses a device for forming thin films made of a powder material, comprising a cylinder provided with a longitudinal groove. This groove is suitable for taking the powder material in a storage area, moving it to a deposition area and depositing a film of material on said deposition area. After deposition, the cylinder compacts the film using a portion of the surface thereof devoid of a groove. Such a device has a relatively long implementation time. Indeed, between each movement of the cylinder between the storage and deposition areas, i.e. after each powder material film formation and before another film formation, it is necessary to reposition the cylinder such that the groove thereof is in a position wherein it can take the powder material. For this, it is necessary to stop the rotation of the cylinder. Moreover, the surface of the cylinder used for compacting only represents 80% of the total developed surface area, given that the groove is not involved in compacting. For this reason, the length of the film suitable for compacting, in one rotation of the cylinder, is limited to approximately 80% of the circumference of the cylinder.
EP-A-776 713 describes a method for producing a sand mould wherein a cylinder spreads and compacts the sand from a hopper in a plurality of layers on a receiving surface.
US-A-2005/0263934 discloses a device comprising a cylinder protected by a cover, the assembly moving to spread and compact, on a receiving surface, a powder, prior to the sintering thereof by a laser. This powder is supplied by a feed member situated above the cylinder.
These devices do not allow effective spreading and compacting of the powder.
SUMMARY OF THE INVENTION
The invention is particularly intended to remedy these drawbacks by proposing a high-performance and rapid device for forming thin films made of a powder material.
For this purpose, the invention relates to a device suitable for forming at least one thin film made of a powder material comprising a storage area, a deposition area, a cylinder having a circular base for depositing and compacting the powder material, said material having been previously moved from a storage area to a deposition area, characterised in that the device comprises:
a cylinder having a smooth cylindrical surface, said cylinder being rotatably movable about the axis of revolution thereof, as well as translatably movable in at least one direction parallel to a main plane in the deposition area, between the storage area and the deposition area, a scraper that is movable in a direction perpendicular to the main plane of the deposition area, as well as translatably movable in the same direction as the cylinder between the storage and deposition areas, the scraper being suitable for moving the powder material from one area to another.
In this way, using a cylinder devoid of a groove, it is no longer necessary to stop after the formation of each film. Moreover, this film may have a greater length than formed with the grooved cylinder known from the prior art.
According to advantageous, but non-mandatory, aspects of the invention, the device may incorporate one or a plurality of the following features:
the cylindrical surface of the cylinder has an apparent roughness suitable for being less than the grain size of the smallest particles forming the powder material. The cylindrical surface of the cylinder has an apparent roughness of approximately 0.06 μm. The sliding friction coefficient of the cylindrical surface on the powder material is suitable for being less than the sliding friction coefficient of the powder material on the surface of the deposition area. The sliding friction coefficient of the cylindrical surface on the powder material is approximately 0.02. The scraper and the cylinder are suitable for moving in translation at the same speed. The movement of the scraper and the cylinder is suitable for being carried out simultaneously, the distance between the scraper and the cylinder being kept constant. The scraper and the cylinder are suitable for moving in translation at different speeds. The movements of the scraper and the cylinder are suitable for being carried out non-simultaneously. A calibration tool suitable for calibrating a film of compacted powder material, after it has been treated with a laser, is arranged in the vicinity of the scraper, so as to precede same when pushing the powder material.
The invention also relates to a method for forming at least one film made of powder material using a device according to any of the above features, characterised in that it comprises steps consisting of:
a) rotating at least one cylinder, upstream from an area for storing the powder material, b) lowering a scraper, c) extracting a predetermined quantity of powder material using the scraper on the storage area, d) pushing the extracted quantity of powder material, using the scraper, from the storage area to a deposition area, e) raising the scraper, f) spreading, using the cylinder, the powder material on the deposition area, g) compacting, using the cylinder, in at least one cylinder passage, the previously spread powder material, h) repeating steps a) to g) to produce the desired number of compacted films.
According to advantageous, but non-mandatory, aspects of the invention, the method may incorporate at least one step where:
Before step g), the method comprises at least one iteration of steps b) to f), in order to spread the powder material in a film of predefined thickness, prior to the compacting thereof After step e) and before step f), the thickness of the material film deposited on the deposition area is at least equal to twice the thickness of the final film of compacted material.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be understood more clearly and further benefits thereof will emerge more clearly on reading the following description of two embodiments of a device according to the invention, merely given as an example, with reference to the appended figures wherein:
FIG. 1 is a general schematic view of a roller and a scraper according to one embodiment of the invention,
FIGS. 2 to 11 are schematic side illustrations of the implementation of the device, the powder material being represented by a dark line on the storage and deposition areas and
FIG. 12 is a schematic illustration, on another scale, of the implementation of a device according to a second embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The roller or cylinder 1 represented in FIG. 1 is made of a material that is easy to machine, stable and insensitive to environmental conditions. In particular, the material used is insensitive to the powder material and is stable at the pressure and temperature conditions usually applied during a laser sintering method. In particularly, such a roller 1 should be suitable for not undergoing any deformation in the range of operating temperatures generally encountered, i.e. between ambient temperature and approximately 1200° C. Advantageously, this roller 1 is made of a material suitable for the operating temperature. For example, the roller is metallic, coated with tungsten carbide for use up to 300° C. For use between 300° C. and 600° C., the roller is made of a single material, tungsten carbide. For temperatures between 600° C. and 1200° C., a ceramic, for example alumina or zirconia, is preferably used.
The roller 1 is cylindrical with a circular base. The outer diameter D thereof is dependent on the length, or height H, thereof. It is necessary to have a mechanically rigid roller to produce a film of powder material with a thickness wherein the precision is less than or equal to 10% of the thickness of the film produced. For example, for a 20 μm thick film, the variation in thickness should be less than 2 μm. The cylindrical surface 2 of this revolving cylinder 1 is continuous and smooth, without any bumps or roughness. The apparent roughness Ra of the cylindrical surface 2 is less than the grain size of the smallest particles of the powder material. In this way, the smallest powder particles do not penetrate the hollows of the cylinder surface. The powder does not remain on the cylindrical surface and the powder can be spread. Advantageously, the surface 2 has a glacial polish appearance, i.e. with an apparent roughness Ra in the region of 0.06 μm. This cylinder 1 is mounted, in a manner known per se, to be rotated about the main axis of revolution A thereof. This rotation may be carried out in the direction indicated by the arrow F 1 in FIG. 2 . In an alternative embodiment, according to the nature of the powder material, the rotation may be carried out in the reverse direction.
In other words, the rotation of the roller 1 may be suitable, depending on the powder material, for being carried out in the trigonometric direction, not shown in FIGS. 2 to 11 , or in the inverse trigonometric direction.
This roller 1 is associated with a scraper 3 also shown in FIG. 1 . This scraper 3 has a length Lr equal to the height H of the cylinder 1 . The scraper 3 comprises a lip 4 . The lip 4 comprises an edge 41 formed by the intersection of two plane surfaces according to an angle less than or equal to 90°. The lip 4 is attached to the main body 31 of the scraper 3 . The lip 4 is advantageously integral with the body 31 . This scraper 3 is made of a material suitable for the operating temperature. In other words, the scraper 3 is, advantageously, made of the same material as the roller 1 .
As illustrated schematically in FIGS. 2 to 11 , the scraper 3 is mounted on a free edge of the protective cover 5 of the cylinder 1 . This mounting is carried out in a removable manner, enabling the replacement, in the event of wear or damage, of the scraper 3 . In one alternative embodiment not illustrated, the scraper 3 is permanently attached to the cover 5 .
In the embodiment described, the cover 5 has a U-shaped cross-section. The cover 5 covers the cylinder 1 on the entire height H thereof, and on the cross-section S thereof. In other words, this cover 5 partially covers the cylinder 1 , while leaving same rotatably movable with a part of the cross-section S extending below the cover 5 , via an opening O of the cover 5 facing downwards, i.e. towards the powder material to be spread.
The assembly formed by the scraper 3 , the cover 5 and the cylinder 1 is mounted on a frame or carriage, not shown and known per se, suitable for moving in translation between an area 6 for storing powder material and an area 7 for depositing powder material.
Such storage 6 and deposition 7 areas are known from FR-A-2 856 614. In this instance, the storage area is formed by a horizontal plate 6 mounted on a plunder rod 8 . This plunger rod 8 is movable in translation, in an upward direction, inside a cylindrical volume having any cross-section. This plate 6 can thus be raised and lowered in a vertical direction, represented by the double arrow F 2 . The plate 6 is situated upstream from and in the vicinity of a horizontal plate 7 acting as a deposition area and mounted on a plunger rod 9 . This plunger rod 9 is also movable in translation, in an upward direction, inside a cylindrical volume having any cross-section. The plate 7 can thus also be raised and lowered in a direction, represented by the double arrow F 3 , parallel with the direction F 2 of movement of the plate 6 . In the example, the plate 7 is represented as identical to the plate 6 . In one embodiment not illustrated, the shape and dimensions of the plates 6 , 7 are different.
In a first step illustrated in FIG. 2 , the roller 1 and the scraper 3 are in a first so-called idle position. In this position, with reference to FIG. 2 , they are positioned to the left of one end 10 of the storage plate 6 , opposite the nearest end 11 of the plate 7 . The scraper 3 is, by the edge 41 of the lip 4 , in the vicinity of one edge 12 of any film, or volume, 13 having any initial thickness e 1 of powder material 14 .
According to the present description, the terms “high”, “low”, “upper” and “lower” relate to the operating configuration of the equipment shown in the figures. In this way, for example, an “upper” part is facing upwards in these figures.
The upper face 130 of the volume 13 is in a plane parallel with and above the upper face 70 of the plate 7 . The cylinder 1 is rotated about the axis A thereof according to a predetermined speed. This rotation F 1 is carried out in a trigonometric direction or in an inverse trigonometric direction, depending on the nature of the powder material 14 . The rotational speed is dependent on the linear translation movement speed of the carriage whereon the scraper 3 , cover 5 and cylinder 1 assembly is mounted. The tangential speed of the cylinder is synchronised with a linear speed of the carriage, in a range of synchronisation ratios that can vary from −100 to 0 and from 0 to 100. The synchronisation ratio is dependent on the physicochemical nature of the powder material.
When the tangential speed of the cylinder is in the same direction as the linear speed of the carriage driving the cylinder, and in a synchronisation ratio of 1, i.e. when the speeds are identical, there is movement of a generatrix of the cylinder 1 on the surface of the powder material 14 . The movement speed of a generatrix of the cylinder 1 on the powder material surface is then double the linear speed of the carriage.
When the tangential speed of the cylinder is in the opposite direction of the linear speed of the carriage driving the cylinder, and in a synchronisation ratio of 1, there is no movement of a generatrix of the cylinder on the surface of the powder material. In other words, rotation of the cylinder 1 on a plane is observed, with no sliding of the cylinder on this plane.
The ratio between the tangential speed of the cylinder 1 and the linear speed of the carriage is suitable for the nature of the powder material 14 and the thickness of the films to be produced.
Simultaneously with the rotation of the cylinder 1 , the cover 5 , and therefore the scraper 3 , is lowered. This movement is produced, for example by pivoting along the arrow F 4 in FIG. 3 , in the opposite direction of the rotation along F 1 of the cylinder 1 . This pivoting of the cover 5 is carried out about a horizontal axis B. In one embodiment not illustrated, the cover 5 is lowered by a vertical translation movement. The simultaneity of movement of the cylinder 1 and the scraper 3 makes it possible to reduce film formation cycle times. If required, moving of the cylinder 1 and the scraper 3 is offset over time.
The assembly comprising the cylinder 1 , cover 5 and scraper 3 is moved in horizontal rectilinear translation. The upper face 130 of the film, or volume, 13 of powder material is situated at a higher height than that of the edge 41 , as shown in FIG. 2 . For this reason, the scraper 3 extracts a predefined volume of powder material. The movement of the assembly is carried out horizontally, along a direction F 5 parallel with a main plane P 1 of the plate 7 and in the direction thereof. P 1 references a horizontal plane generated by horizontal movement of the edge 41 above the plate 6 . Due to the lowering of the cover 5 , the plane P 1 is situated below a plane P 2 tangent to a lower generatrix G of the cylinder 1 . In other words, in this position illustrated in FIG. 3 , the scraper 3 is suitable for pushing, along the arrow F 5 of the extracted powder material 14 , below the face 130 , in the volume 13 , in the direction of the plate 7 without the rotating roller 1 coming into contact with the powder material 14 , since the cylinder 1 generatrix G is situated above the plane P 1 .
The scraper 3 thus pushes a predetermined quantity of powder of the first end 10 of the storage area 6 to the second end 11 thereof. The quantity of powder 14 pushed by the scraper 3 is defined by the difference between the plane P 1 and the upper face 130 of the volume 13 , it being understood that it is possible to vary this difference by raising or lowering the plate 6 .
The translation movement, along the arrow F 5 , is carried out at a predetermined speed, selected according to the nature of the powder material and/or the desired features of the final layer. In this instance, this speed is generally between 0.05 m/s and 1 m/s for a movement of the cylinder 1 and scraper 3 assembly above the feed area 6 .
In this embodiment, the scraper 3 and the cylinder 1 move in translation at the same speed, keeping a constant distance E between them. This is enabled by the presence of a common member, i.e. a carriage, not shown, defining the axes A and B of rotation, respectively, of the cylinder 1 and the cover 5 .
In one embodiment, not illustrated, where the scraper 3 is not attached to a member integral with a supporting member of the cylinder 1 , the movement speeds of the scraper 3 and the cylinder 1 may be different and vary according to the film formation phases. In other words, the distance E is varied between the cylinder 1 and the scraper 3 .
A solid area 15 provided on the frame connects the plates 6 , 7 and enables the passage of powder extracted from the volume 13 between the plates 6 and 7 . This area 15 is situated in a plane P 3 parallel with the plane P 1 and below said plane. This plane P 3 is defined, in other words, by the lower face of the film of powder material deposited on the plate 7 .
When the scraper 3 has pushed the powder 14 to the end 16 of the plates 7 situated facing the end 11 of the plate 6 , as illustrated in FIG. 4 , the cover 5 is pivoted about the axis B, in the opposite direction of the first pivoting of the cover 5 and along the arrow F 6 , to raise the scraper 3 . In this position, illustrated in FIG. 5 , a pile T of powder 14 , representing a predefined quantity, is placed in the vicinity of the end 16 , ready to be spread on the deposition area 7 .
As the cylinder 1 is rotating about the axis A from the start of the work cycle, i.e. before the scraper 3 is lowered to push the powder 14 , there is no idle time for the start-up thereof. The cylinder 1 can immediately be activated, when the scraper 3 is raised. Only raising the scraper 3 requires a stoppage of the translation of the cylinder 1 and cover 5 assembly. Nevertheless, this stoppage time is extremely brief, or non-existent, depending on the synchronisations between the various servo-control devices and/or the envisaged operating speeds.
The cover 5 is raised such that the lip 4 of the scraper 3 is above the pile T of powder 14 and does not impede the action of the cylinder 1 .
As illustrated in FIG. 6 , the roller 1 , rotating along F 1 , makes a horizontal translation movement along F 5 , from the end 11 towards the end 17 of the plate 7 opposite the end 16 , at a given speed, which may be different to that observed during the movement above the area 6 . The movement results in the cylinder 1 , hitherto situated above the plate 6 , to come into contact, by the cylindrical surface 2 thereof, with the pile T.
FIG. 7 illustrates the following film formation phase per se or spreading of the powder material 14 on the deposition area 7 using the cylinder 1 . This film formation is performed uniformly by translation movement, along the arrow F 5 , of the cylinder 1 rotating along F 1 .
During this phase, the cylinder 1 pushes the excess powder 14 back in front of said cylinder. The rotation and movement of the cylinder 1 parallel with the plane P 1 makes it possible to spread the powder 14 in a film 13 ′ of a predetermined thickness. The surface 2 of the cylinder 1 is smooth and has a low apparent roughness, similar to that of a glacial polish, preventing any adherence of the powder 14 on the cylindrical surface 2 of the roller 1 . This makes it possible to obtain a homogeneous and regular film 13 ′, having a minimum thickness of approximately 1 μm, according to the geometric precision, the surface condition of the cylinder 1 and/or the grain size of the powder. In the example described, the minimum feasible thickness is approximately 5 μm. Films having a thickness greater than 10 μm can also be produced.
During film formation, the cylindrical surface 2 of the cylinder 1 is not in contact with the plane P 1 of the film previously sintered or fused using a laser. This lack of contact is dependent, inter alia, on the homogeneity and compactness of the powder film and the grain size and granularity thereof.
The formation of films made of powder material 14 may be carried out in a single iteration, i.e. a single return passage of the cylinder 1 and the scraper 3 . According to the physicochemical features and/or the expected quality and/or the predetermined thickness of the spread film, it is possible to perform a plurality of iterations, i.e. a plurality of passages to form the final film of spread powder, before compacting. In this case, films of intermediate thickness between the thickness of the first film and the thickness of the final film are formed.
The thickness of an intermediate film, formed during an iteration n may be subject to a variation defined according to the following function: (ax+b)/(cx+d). It is possible use other types of variation of the thickness between two intermediate films, in order to approach, more or less progressively, the desired final thickness of the film 13 ′ before compacting.
The first passage, i.e. the first iteration, for depositing the first film will now be described, it being understood that the subsequent iterations are similar, until the desired thickness of the powder material film is obtained. Advantageously, the thickness of the film of powder material deposited on the deposition area, prior to compacting, is greater than the thickness of the compacted final film. Preferably, this thickness is at least twice the thickness of the compacted final film.
During this first iteration, the thickness of the layer 13 ′ is greater than the desired thickness of the finished film 13 ″.
In FIG. 8 , the roller 1 has reached the end 17 of the plate 7 and has finished spreading the powder material 14 in a film 13 ′ on the deposition area 7 . In this position, the cylinder 1 rotates continuously, and the scraper 3 is raised. The spreading phase is complete.
The cylinder 1 , scraper 3 and cover 5 assembly returns to the position occupied in FIG. 6 , i.e. at the end 16 of the deposition area 7 . During this return, along the arrow F 7 , rotation of the roller 1 is maintained. Movement along F 7 is performed at a higher speed than the initial movement along F 5 . In an alternative embodiment, the movement speeds, along the arrows F 5 and F 7 , are identical. The movement speeds along the direction F 5 may vary between each iteration.
During this return movement, the plunger 9 of the plate 7 is lowered, along F 3 , by some tens of microns so that the rotating roller 1 does not come into contact with the previously spread film 13 ′.
As illustrated in FIG. 9 , a second translation movement, along F 5 , of the cover 5 and cylinder 1 assembly, rotating continuously, compacts the film 13 ′ of previously deposited powder 14 . The speed of this movement may be optionally equal to the speeds observed during previous translation movements above the areas 6 and 7 . For this, the plunger 9 of the deposition area 7 is raised by a value such that the distance between the lower face of the deposited film 13 ′, i.e. the upper face 70 of the plate 7 when said plate is empty, and a lower generatrix G of the cylinder 1 is equal to the desired final thickness of the film 13 ″.
This thickness d may be achieved in a single passage, as illustrated in FIG. 10 , by a translation movement along F 5 , of the rotating cylinder 1 , the scraper 3 being held in the raised position. This compacting phase is repeated the number of times required, according to the powder material 14 . In particular, the number of passages required to achieve the desired thickness d of the compacted film 13 ″ is dependent on the physicochemical nature of the powder 14 , the grain size and/or granularity of said powder. In other words, the mathematical progression intended to achieve the desired thickness d of the film 13 ″ of material 14 is, for example, a decreasing non-linear progression, i.e. of the type (ax+b)/(cx+d). This progression is similar to the progression intended to achieve the predetermined thickness of the spread film.
The compacting to be carried out is calculated on the basis of the thickness of each constituent film of the object to be produced. This thickness is dependent on the height of the object and the desired number of films to produce the object. Due to the powder density variation in a film, the thickness d of the compacted final film is equal to the thickness of a constituent film of the object increased by a fraction of said thickness as a function of a defined compacting ratio.
During compacting, it is necessary for the cylindrical surface 2 of the roller 1 to have a sliding friction coefficient Fg on the powder 14 less than the sliding friction coefficient of the powder 14 on the surface of the deposition area 7 . In this way, during compacting, the powder material 14 remains deposited on the deposition area 7 and is not moved by the rotating roller 1 . Advantageously, the sliding friction coefficient Fg is approximately 0.02.
When the compacting is carried out, as illustrated in FIG. 10 , the roller 1 is situated beyond the end 17 of the deposition area 7 , in the same configuration as that represented in FIG. 8 . The cylinder 1 rotates continuously, with the scraper 3 raised. On the other hand, compared to the position illustrated in FIG. 8 , the cylindrical surface 2 is closest to the upper face 70 of the plate 7 .
It is necessary to return the scraper 3 and cylinder 1 assembly to the initial position thereof, i.e. that occupied to take powder material 14 from the storage area 6 , as illustrated in FIG. 2 . For this, the cylinder 1 , rotating continuously, and the cover 5 are returned along a translation movement F 7 to the end 10 of the storage area 6 .
With some types of ductile powder, it is also possible to spread and/or compact the powder during the movement of the cylinder 1 along the direction F 7 .
When the cylinder 1 and the cover 5 are at the end 10 of the storage area 6 , the scraper 3 is lowered again, along F 4 , to push another quantity of powder material 14 in another film formation cycle. During this return movement of the cylinder 1 to the initial position thereof, the plunger 9 of the deposition area 7 is lowered again, in order to release the film 13 ″ from the cylinder 1 , which is rotating continuously and should not be in contact with the compacted layer 13 ″.
When the film 13 ″ is compacted, it undergoes a laser treatment, not illustrated, i.e. sintering or fusion, enabling the formation of a solid film forming a three-dimensional object.
In a new cycle, it is simply necessary to mount the plunger 8 of the feed area 6 before lowering the scraper 3 to resume a film formation cycle.
FIG. 12 illustrates a further embodiment wherein a second cylinder R 2 , for example identical to the cylinder 1 , is arranged in the vicinity thereof. The axes of rotation of the two cylinders 1 and R 2 are parallel. The cylinders 1 , R 2 are arranged such that the respective contact areas thereof, i.e. lower generatrices of the cylinders, are at different heights. This difference X in height is adapted according to the nature of the powder 14 and the thickness of the compacted film to be achieved. In other words, X is the result of a decreasing non-linear progression of the type (ax+b)/(cx+d).
The presence of this second cylinder R 2 thus makes it possible, in a single passage, to carry out compacting which, with a single cylinder 1 would have required two passages. This reduces the time required to obtain a compacted film 13 ″. The rotational speed and/or the direction of rotation of the cylinders 1 , R 2 are adjustable. These parameters may be optionally identical for both cylinders 1 , R 2 . The same applies for the translation movement parameters of the cylinders 1 , R 2 .
A tool R 3 is represented schematically in FIG. 12 , in the vicinity of the scraper. It consists of a calibration tool, for example a mill type tool. The tool R 3 comprises working parts, in this instance teeth, made of a material having a hardness greater than that of the film 13 ″ after said film has undergone laser treatment, i.e. after the compacted powder material has undergone laser fusion or sintering. This tool R 3 is, for example, made of tungsten carbide. The film of compacted powder material treated with a laser is, for more clarity, represented in dotted lines under the single tool R 3 , it being understood that this film extends under the entire plate 7 .
The tool R 3 makes it possible, by preceding the scraper 3 when the powder 14 is pushed onto the plate 7 to produce an additional film, to calibrate the previously produced powder film 13 ″, once said film has been treated with a laser.
Indeed, when a previously spread and compacted film, has undergone laser sintering or fusion, irregularities or microreliefs may appear on the surface of the film having undergone laser treatment, particularly following the production of objects with undercuts. R 3 thus makes it possible to render the surface of this film even, by removing a few mm 3 of material, prior to the formation of the subsequent film.
Advantageously, R 3 is mounted on the same carriage as the cylinders 1 , R 2 and the scraper 3 . In an alternative embodiment, R 3 is mounted removably and/or on another carriage to that supporting the scraper 3 and the cylinders 1 , R 2 .
The speeds of rotation and movement of the tool R 3 are suitable for the powder material 14 when said material has been treated with a laser.
The directions of movement of the cylinders R 2 , 1 and the tool R 3 are coordinated.
In a further embodiment, not illustrated, the cylinder 1 , cover 5 and scraper 3 assembly are suitable for vertical movement. It is then possible to raise the plunger 8 and lower the cylinder 1 , cover 5 and scraper 3 assembly to adjust the quantity of powder 14 to be spread.
The continuous rotation of the roller 1 makes it possible to obtain a rapid implementation of said roller, without stopping the cycle to reposition same.
Since the cylindrical surface 2 is fully used during compacting, it is possible to compact powder films of significant length.
In embodiments not illustrated, the shape of the cover 5 may be different to that described.
In an alternative embodiment, the scraper 3 may be attached to an arm connected to an axis of rotation of the cylinder, said cylinder being devoid of a protective cover.
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The invention relates to a device for forming at least one thin film made of a powder material ( 14 ). The device includes a storage area, a deposition area ( 7 ), and a cylinder ( 1 ) having a circular base for depositing and compacting the powder material ( 14 ), the latter having been previously moved from a storage area to a deposition area ( 7 ). The device further includes a cylinder ( 1 ) having a smooth cylindrical surface, said cylinder being rotatably movable (F 1 ) about the axis of revolution (A) thereof, as well as translatably movable in at least one direction (F 5 ) parallel to a main plane in the deposition area ( 7 ), between the storage and deposition ( 7 ) areas; a scraper ( 3 ) that is movable in a direction perpendicular to the main plane of the deposition ( 7 ) area, as well as translatably movable in the same direction (F 5 ) as the cylinder ( 1 ), between the storage and deposition ( 7 ) areas, the scraper ( 3 ) being adapted to move the powder material from one area to another ( 7 ).
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CLAIM OF PRIORITY
[0001] The present Application claims the priority of U.S. Provisional Patent Application No. 61/233,140, entitled “Secure dispensing system for multiple consumables,” by Miriam M. Flores, filed Aug. 12, 2009, and is incorporated by reference herein in its entirety.
FIELD OF TECHNOLOGY
[0002] This disclosure relates generally to the field of a secure dispensing system for several types of consumables. The secure dispensing system, when secured to a chambered bottle containing the consumables is convenient to carry, use, quickly open and close, refill with ease and has an elegant and beautiful appearance.
BACKGROUND
[0003] Generally, a person has to carry two different types of containers for different consumables such as a perfume and a face cream, tooth paste and a mouth wash, shaving cream and after shave lotion, diaper rash cream and baby cream, hair spray and mousse, shampoo and conditioner, sun screen and moisturizer cream, disinfectant anti-bacterial and soap, hand sanitizer and hand lotion and a water and a drink etc.
[0004] The containers may be large and may not be convenient to carry such as in carry on luggage or a ladies purse. New security systems prohibit carrying bulky liquid containers. It also makes it bulky to carry when one is travelling and/or going to remote locations where certain necessary consumables may not be available.
SUMMARY
[0005] In one embodiment a secure dispensing system is disclosed. The dispensing system has more than one dispenser. The dispensers are separated by a unique security tab that prevents the dispensers to be suppressed accidentally. The security tab prevents the other dispenser to be pressed while using the first dispenser.
[0006] The security tab can be screwed in, snapped on or attached by sliding on and the dispenser heads for a particular container can be interchanged based on the requirement. The security tab may be in the form of a lid on top of the dispensers.
[0007] In one embodiment the dispenser may be placed at 90° and/or 180° or 240° angles from each other. In another embodiment they can be parallel to each other. In one embodiment they can be facing the same direction or they can be at opposite directions.
[0008] In an embodiment a dual dispenser container including a segmented container carrying different consumables is disclosed. The segmented container enables the user to dispense the consumable of choice either separately or simultaneously at a specific instance. This would also prevent unnecessary discharge of one consumable when the other is being used.
[0009] In one aspect, a single container having a separated segment and dual dispenser is disclosed. In another aspect, a container having two different consumables that are immiscible are separated in a segmented container and have their individual dispensing apertures. One aperture may be a spray aperture and the other could be a spout aperture. The top of the container would have a rigid lid partially covering the two apertures so that when one type of dispenser top is used, the other is not accidentally suppressed and consumable is not discharged.
[0010] A container may have two spray apertures for dispensing two aerosol liquids such as a perfume and an Eu de toilette or Eu de cologne. The security tab covering both the apertures may be a screw tight or press shut type and can be round shape, t-shaped or square shaped. This would prevent accidental spillage of the consumables from the container.
[0011] A container may have two spout apertures to dispense consumables such as a diaper rash cream and a baby cream. The apertures may be opened and closed individually so that a person can operate one aperture at a time instead of both. The container would be suitably labeled outside so that a distinction could easily be made for the intended purpose and the suitable consumable for a particular instance.
[0012] The container may contain a pivoting lid so that one aperture at a time can be opened. The pivoting lid would close one of the apertures so an individual can use one consumable at a time.
[0013] A container may have a combination of apertures such as a spray dispenser and a spout dispenser to store a combination of consumables such as a tooth paste and a mouth wash, a perfume and a hand lotion, shaving cream and after shave lotion, diaper rash cream and baby cream, hair spray and mousse, shampoo and conditioner, sun screen and moisturizer cream, disinfectant anti-bacterial and soap, hand sanitizer and hand lotion, a water and a drink etc.
[0014] A container may have rigid separated segments for two different consumables. The container may also have a replaceable and disposable sub-segment that can be inserted once a particular consumable has been used up. The container itself may be reusable or disposable.
[0015] The apertures may be designed as a lid that are detachable from one container and fit into another container of similar size. The container is portable and suitable for personal use. The container is suitable for carry-on luggage, personal luggage and remote area usage such as camping.
[0016] Other features will be apparent from the accompanying drawings and from the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Example embodiments are 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:
[0018] FIG. 1 illustrates an exterior view of a secure dispensing system, according to one embodiment.
[0019] FIG. 2 illustrates a cross sectional view of the dual dispenser container illustrated in FIG. 1 , according to another embodiment.
[0020] FIG. 3 illustrates a structural view of a nozzle of a dual dispenser container, according to one embodiment.
[0021] FIG. 4 illustrates assembling of the dual dispenser nozzles, according to one embodiment.
[0022] FIG. 5 illustrates the function of a security tab, according to one embodiment.
[0023] FIG. 6A illustrates a side view of a dual dispenser container with a spray aperture, according to one embodiment.
[0024] FIG. 6B illustrates a side view of a dual dispenser container with a spout aperture, according to one embodiment.
[0025] FIG. 7A illustrates a multiple chamber dispenser container, according to one embodiment.
[0026] FIG. 7B illustrates a side view of a multiple chamber dispenser container with spout dispensers, according to one embodiment.
[0027] FIG. 7C illustrates a side view of a multiple chamber dispenser container with spray dispensers, according to another embodiment.
[0028] FIG. 8 illustrates assembling of two dispenser container, according to one embodiment.
[0029] FIG. 9 A illustrates a view of a secure dispensing system with a cylindrical two dispenser container having a spout aperture and spray aperture.
[0030] FIG. 9 B illustrates a view of a cylindrical two dispenser container with two spray apertures.
[0031] FIG. 10 illustrates a view of a cylindrical two dispenser container with two spout apertures.
[0032] Other features of the present embodiments will be apparent from the accompanying drawings and from the detailed description that follows.
DETAILED DESCRIPTION
[0033] A secure dispensing system is described. Although the present embodiments have been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the various embodiments.
[0034] FIG. 1 illustrates an exterior view of a secure dispensing system 100 , according to one embodiment. In one embodiment, FIG. 1 illustrates a dual dispenser container 150 and outer surface 168 that can hold two dispenser containers. The dual dispenser container 150 may be provided with a cap 164 . The cap 164 may include ridges 166 that may allow the cap 164 to fit properly to the neck of the container over cap screwing area 154 . The security tab 160 and security tab limb 162 may be placed in between the dispenser tabs, so that fortuitously one cannot press both together.
[0035] The dual dispenser container 150 may include two dispenser containers to store different consumables in each container. The consumables in each dispenser container may be dispensed through the nozzles while maintaining a consistent and aesthetically pleasing appearance at the time of usage of the consumables.
[0036] The apertures of the nozzle may be enclosed by the cap 164 so that the accidental spilling of the consumables in the containers may be avoided. For example, the contents may not spill out when the dual dispenser container 150 is placed inclined in the hand baggage or suitcase during traveling. Any type of cap that can fit to the nozzle may be used. For example, the cap 164 may be a screw on cap, a twist cap, a snap shut cap, a pull-off cap, etc. The cap 164 may also be a flip-open top for a convenient consumer use.
[0037] The dispenser containers may contain consumables of same viscosity or different viscosities and the contents in the containers may be dispensed separately. The dispenser containers may include a spray dispenser and/or a spout type dispenser (e.g., a dispenser A 156 or a dispenser B 158 as illustrated in FIG. 1 ). The containers may be replaceable and/or reusable. The nozzle may be of any configuration, such as, a pin hole tip, slit, atomizer, or the like to suit the spray and/or spout mechanism. The internal containers and outer bottle may be of any form or pattern to suit the dispensing application at hand.
[0038] The dimension of the apertures in the nozzle may be determined based on the viscosity and rheology of the contents to be filled in the dispenser containers of the dual dispenser container 150 . A smaller dimension is chosen for the apertures when the content has a lower viscosity and a larger dimension is chosen for the aperture when the content has a higher viscosity.
[0039] The dual dispenser container 150 may provide easy storage and distribution of the consumables. In addition, the dual dispenser container 150 may be molded to any convenient shape and size. The dual dispenser container may be made of at least one of glass, thermoplastic material, biodegradable material and plastic. The container pouches may be available in the market along with the contents or may be filled by the user In an example embodiment, the dispenser containers may be used to store cosmetic consumable product (e.g., body lotion, perfumes, shampoo, conditioners, hair spray, etc.), hygienic consumable product (e.g., disinfectant solutions, cleansing gels etc.), paint consumable product (e.g., paint, solvent, etc.), medicinal consumable product (e.g., mouth wash, pain relief creams/gels, bug repellents, anti-allergic solutions or creams etc.), drinking consumable product (e.g., water, juices, soft drinks, soda water etc.), and any other similar products.
[0040] In another embodiment, the dual dispenser container 150 and the dispenser containers inside it may be made up of transparent material or a translucent material that may allow a user to see through the contents of the containers. The dual dispenser container 150 may be durable and safe to use.
[0041] FIG. 2 illustrates a cross sectional view of the dual dispenser container illustrated in FIG. 1 , according to another embodiment.
[0042] In an embodiment, the dual dispenser container 150 may be provided with effective containers for storing and dispensing different consumables that are frequently used at the same time or uninterruptedly used one after the other. The containers may include different types of consumables of various viscosities that are packaged for dispensing by a user either individually or collectively as the user requires. The dual dispenser container 150 may have a thick double wall 220 to protect the containers (e.g., pouches) enclosed inside it.
[0043] In an example embodiment, the dual dispenser container 150 may include a container A 212 and a container B 210 to store different consumables separately. The containers may be provided with a partition wall 216 as illustrated in FIG. 2 . The dispensing nozzle may be placed on the container neck 152 as illustrated in the FIG. 2 . The container A 212 and the container B 210 may be of the same size or different size and may be made up of any material that may not react with the contents of the container. For example, the containers may be made up of a suitable material that may include low density polyethylene, high density polyethylene, foils (e.g., aluminum foil) etc. The container A 212 , the container B 210 , and/or dual dispenser container 150 may be made up of polyethylene, polypropylene terpthalate, polyvinyl chloride (PVC), copolymers, and/or co-extrusions.
[0044] Each container may have a tube (e.g., duct) through which the consumable fluid of the container may dispense through the nozzle. The container A 212 may be provided with a spray tube 206 and the container B 210 may be provided with a spot tube.
[0045] FIG. 3 illustrates a structural view of a nozzle of a dual dispenser container, according to one embodiment.
[0046] According to one embodiment, the dispensers may include a passageway linking to the respective containers. For example, the dispenser B 158 may include the spray passage way 318 and the dispenser A 156 may include the spout passageway 322 . When the spot dispenser tab is pressed, a spring 324 attached to the spout passageway 322 may be compressed and the consumable may be sucked from the container through the spout tube 204 attached to the nozzle and cause the consumable in the container to spout through the aperture of the nozzle. In another embodiment, when the spray dispenser tab is pressed, a spring attached to the spray passageway 318 at the container neck may be compressed. This may change the pressure inside the spray tube 206 attached to the dispenser nozzle and cause the consumable to be pulled up the tube, past bulb 316 , swiftly and sprayed out through the aperture of the dispenser B 158 .
[0047] The spray dispenser may be used to dispense the consumables such as perfumes, mouth wash, disinfectants etc. The spout type of dispenser may be used to squirt the consumables such as body lotion, hand lotion, shampoo, shaving cream, etc. The nozzle of the may be closed with the cap 164 to avoid spilling of the contents of the containers.
[0048] The security tab 160 may be placed in between the dispenser tabs, so that fortuitously one cannot press both together. The security tab 160 may be made of hard and solid material so that it will not break easily when pressed. The passageways on the top of the nozzle are deflected in an opposite direction so that the two liquids do not mix.
[0049] FIG. 4 illustrates assembling of the dual dispenser nozzles, according to one embodiment.
[0050] According to one embodiment, the different types of dispensers (e.g., spray dispenser, and/or spout dispenser) may be fitted depending on the consumable filled in the containers. In step 1 , the dispenser B 158 may be fitted to the neck of the container. Screwing area 404 may be provided to fix the security tab 160 firmly between the dispenser A 156 and the dispenser B 158 .
[0051] In another embodiment, the dispenser A 156 may be fitted to the neck of the container as illustrated in step 2 . The security tab 160 may be placed between the dispenser A 158 and the dispenser A 156 . The security tab 160 may be in a ‘T ’shape. A vertical limb 414 of the security tab 160 may be placed in between the dispenser B 158 and the dispenser A 156 . A horizontal limb 406 of the security tab 160 may be placed on the top surface of the two dispensers (e.g., the dispenser A 156 and the dispenser B 158 ). The security tab 160 may be provided with a screw thread 412 at the end of the vertical limb 414 , to fix the tab firmly in the screwing area 404 . The security tab 160 may be rigid and do not bend when its upper surface 408 is pressed. In yet another embodiment, step 3 illustrates the security tab fitted between the dispenser tabs as illustrated in FIG. 4 .
[0052] FIG. 5 illustrates the function of a security tab, according tone embodiment. In an embodiment, 502 illustrate the position of the security tab 160 and the dispenser B 158 before pressing the dispenser tab. In another embodiment, 504 illustrate the position of the security tab 160 and the dispenser B 158 after pressing the dispenser tab. The security tab 160 remains stationary before dispensing and after dispensing the consumable. Only the consumable (e.g., perfume, room freshener, etc) is dispensed from an aperture of the dispenser B 158 and nothing is dispensed from the dispenser A 156 . When the dispensing tab is pressed the tab moves down, whereas the security tab 160 remains fixed in its position. The security tab 160 may be hard and inflexible and avoid accidental pressing of both the dispenser tabs simultaneously.
[0053] FIG. 6A illustrates a side view of a dual dispenser container with a spray aperture, according to one embodiment. In one embodiment, FIG. 6A illustrates a dual dispenser container 650 containing two containers filled with consumables as illustrated in FIG. 6A . For example, the containers may be filled with room freshener and insect disinfectant, perfumes, lens cleaning agent etc. Each container may be provided with an aperture (e.g., a spray aperture 602 ) through which a consumable of the container can be sprayed. The containers may be labeled outside so that a user can distinguish easily and use a suitable consumable. The dual dispenser container 650 may be provided with a cap 654 to avoid accidental spilling of the consumables. The dual dispenser container 650 may be provided with a thick double wall to protect the pouches (e.g., consumable containers) enclosed inside.
[0054] FIG. 6B illustrates a side view of a dual dispenser 652 container with a spout aperture, according to one embodiment. In particular, FIG. 6A illustrates the dual dispenser container 650 containing two containers filled with consumables as illustrated in FIG. 6B . For example, the containers may be filled with shampoo and conditioner that may be used in one instance. Each container may be provided with an aperture (e.g., a spout aperture 604 ) through which a consumable of the container can be dispensed. The containers may be labeled outside so that a user can distinguish easily and use a suitable consumable. The dual dispenser container 650 may be provided with a cap 654 to avoid accidental spilling of the consumables.
[0055] FIG. 7A illustrates a multiple chamber dispenser container, according to one embodiment. The multiple chamber dispenser container may include dual chambers, four chambers and six chambers, a container A 704 , a container B 706 , a container C 708 , and a container D 710 in its chambers. In an example embodiment, the containers 704 , 706 , 708 , and 710 may be used to store consumables that may need to be used consecutively. For example, the multi chambered container may be used to store shower gel, shampoo, conditioner, and/or body lotion. In addition, the containers may also be used to store beverages, chemicals, inks, cosmetics, beverages, medicinal consumables, etc. The containers 704 , 706 , 708 , and 710 may be provided a spout type of dispensers and/or spray type of dispensers depending on the type of the consumable filled in the containers.
[0056] FIG. 7B illustrates a side view of a multiple chamber dispenser container with spout dispensers, according to one embodiment. According to one embodiment, the multi chamber dispenser container may provide an option to include multiple spout dispensers, wherein in the cap, the first dispenser, the second dispenser, the container neck, the container are movable parts. Particularly, FIG. 7A illustrates a side view of a multiple chamber dispenser container with spout apertures (e.g., a spout aperture 714 ).
[0057] FIG. 7C illustrates a side view of a multiple chamber dispenser container with spray dispensers, according to another embodiment. The type of dispenser (e.g., spout and/or spray) may be chosen depending upon the type of consumable to be stored in the containers. In particular, a side view of multiple chamber dispenser containers with spray type of aperture (e.g., a spray aperture 716 ) is illustrated in FIG. 7C .
[0058] FIG. 8 illustrates assembling of two dispenser container, according to one embodiment. In an embodiment, an upper section 808 of the dispensing container and an upper section 806 of the other dispensing container may be fitted into the container neck 152 by twisting in the direction of the arrows as illustrated in FIG. 8 . The dispenser A 156 and the dispenser B 158 may be fitted to the container neck with the security tab between them. The dispenser A 156 may be a spout dispenser and the dispenser B 158 may be a spray dispenser.
[0059] FIG. 9 A illustrates a secure dispensing system 100 containing a cylindrical dual chamber container containing lotion 940 with a spout dispenser 930 and a spray dispenser 920 . The security tab 160 is round in shape and spans both of the spout and spray dispensers. The spray and spout dispensers are parallel to each other in this configuration.
[0060] FIG. 9 B illustrates a cylindrical dual chamber container enclosed by an outer container with dual spray aperture 920 . The entire dual dispenser assembly is externally covered by a round screw on cap 164 . The dual dispenser 900 may contain liquid 960 on both sides of the segmented wall or base 910 .
[0061] FIG. 10 is similar to FIGS. 9 A and 9 B, but has two spout dispensers, spout aperture 930 A and spout aperture 930 B, as another embodiment. This type of assembly may be used for lotion 1010 dispensing. The figure shows a screw on type of cap 164 . In another embodiment it can be a snap shut type of cap as well.
[0062] In view of the above, it will be seen that several objects of the invention are achieved and others advantageous results attained. Accordingly, the specification and drawings are to be regarded in an illustrative sense rather than a restrictive sense.
[0063] Although the present embodiments have been described with reference to specific example embodiments, it will be evident that various modifications and/or changes may be made to these embodiments without departing from the broader spirit and/or scope of the various embodiments.
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A security tab isolating varied dispensing apertures with a multi chamber consumable container is disclosed. In one embodiment the dispensing apertures are similar and have either a spray dispenser or a spot dispenser. In another embodiment they may have dissimilar apertures such as a spray dispenser and a spout dispenser. The dispensing aperture can be operated simultaneously or separately. The dispensing aperture may be sealed individually or together with a security tab. The sealing of the dispensing apertures with a security tab enables the user to select the consumable of choice, to prevent loss and accidental usage of the wrong consumable.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of priority under 35USC §119 to Japanese Patent Application No. 2004-013392, filed on Jan. 21, 2004, the contents of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a charged particle beam apparatus, a charged particle beam control method, a substrate inspection method and a method of manufacturing a semiconductor device.
[0004] 2. Related Background Art
[0005] Heretofore, for a deflector used in a charged particle beam apparatus, for example, an electrostatic deflector, a quadruple or octal deflector has been generally used which comprises four or eight electrodes arranged to surround an optical axis, and positive and negative voltages are applied to the electrodes facing across the optical axis to produce an electrostatic field which controls a charged particle beam. This will be specifically described with reference to the drawings.
[0006] FIGS. 9A to 9 D are sectional views showing an electrostatic deflector described in T. H. P. Chang et al, Multiple electron-beam lithography, Microelectron. Eng. 57-58 (2001) 117-135. FIG. 9A is a sectional view of a quadruple deflector 820 comprising four fan-shaped flat electrodes EL 820 a to EL 820 d , which is cut along a plane perpendicular to an optical axis Ax, and FIG. 9B is a sectional view of the deflector 820 along an X axis of FIG. 9A . Further, FIG. 9C is a sectional view of an octal deflector 822 comprising eight fan-shaped electrodes EL 822 a to EL 822 h , which is cut along a plane perpendicular to an optical axis Ax, and FIG. 9D is a sectional view of the deflector 822 along an X axis of FIG. 9C .
[0007] Describing, for example, the octal deflector 822 shown in FIG. 9C , for deflection in a forward direction (arrow direction) on the X axis, a voltage of (!2-1) V is applied to the electrode EL 822 a , V to the electrode EL 822 b , V to the electrode EL 822 c , (!2-1) V to the electrode EL 822 d , −(!2-1) V to the electrode EL 822 e , - V to the electrode EL 822 f , −V to the electrode EL 822 g , and −(!2-1) V to the electrode EL 822 h , so that a tertiary term of the electrostatic deflection field disappears to allow for a wider uniform electric field area. This enables beam deflection with significantly reduced deflection aberration.
[0008] Also, a proposal has been made to improve optical performance in an electron beam lithography apparatus using the deflectors shown in FIGS. 9A to 9 D. FIG. 10 is a partial configuration diagram showing an electron beam lithography apparatus described in Japanese laid open (kokai) No. 2001-283760. In an electron beam irradiation device 900 shown in FIG. 10 , an electrostatic main deflector 952 is disposed in a magnetic field of a magnetic objective lens 954 , and a pre-deflector 950 is disposed on an object surface side of the objective lens 954 while a post-deflector 953 is disposed on an image surface side of the objective lens 954 . The electron beam irradiation device 900 shown in FIG. 10 is used in the electron beam lithography apparatus, and widely deflects an electron beam EB on a wafer W which is a sample, in order for a faster lithography process. Therefore, a deflection system is optimized in such a manner that deflecting voltages are lowered by maintaining high deflection sensitivity and that coma aberration and an incidence angle of the electron beam EB on the wafer W will be 0. The optimization of the deflection system in the device of FIG. 10 is implemented in accordance with locations of a plurality of deflectors on the optical axis, a voltage ratio among the deflectors, and phase setting.
[0009] However, if an attempt is made to further increase the resolution of the electron beam irradiation device 900 shown in FIG. 10 or to increase the amount of deflection of the electron beam EB, more deflectors are arranged inside, in front of and in the rear of the objective lens 954 , thus increasing the number of components and wires on the periphery of a pole piece of the objective lens 954 . This increases the burden on mechanical assembly, and makes it difficult to produce a higher vacuum on the periphery of the pole piece due to an increase of exhaust resistance. Another problem is an increase in the number of power sources due to the increase in the number of deflectors. On the other hand, there is a limit to the actual number of deflectors and to arrangement space, which does not allow for optimal locations on a physical design, thus making it difficult to further improve performance.
SUMMARY OF THE INVENTION
[0010] According to a first aspect of the invention, there is provided a charged particle beam apparatus comprising:
[0011] a charged particle beam generator which generates a charged particle beam;
[0012] a projection optical system which generates a lens field to focus the charged particle beam on an external substrate; and
[0013] deflectors arranged so as to surround an optical axis of the charged particle beam; the deflectors generating a deflection field which is superposed on the lens field to deflect the charged particle beam and to control a position to irradiate the substrate, and being configured so that an intensity of the deflection field is changed in a direction of the optical axis in accordance with an angle with which the charged particle beam should fall onto the substrate.
[0014] According to a second aspect of the invention, there is provided a charged particle beam apparatus comprising:
[0015] a charged particle beam generator which generates a charged particle beam;
[0016] a projection optical system which generates a lens field to focus the charged particle beam on an external substrate; and
[0017] deflectors comprising electrodes or magnetic cores arranged to surround an optical axis of the charged particle beam; the deflectors generating a deflection field which is superposed on the lens field and deflecting the charged particle beam by the deflection field to control a position to irradiate the substrate, wherein space between surfaces of the electrodes or magnetic cores across the optical axis changes stepwise in a direction of the optical axis.
[0018] According to a third aspect of the invention, there is provided a charged particle beam apparatus comprising:
[0019] a charged particle beam generator which generates a charged particle beam;
[0020] a projection optical system which generates a lens field to focus the charged particle beam on an external substrate; and
[0021] deflectors comprising electrodes or magnetic cores arranged to surround an optical axis of the charged particle beam; the deflectors generating a deflection field which is superposed on the lens field and deflecting the charged particle beam by the deflection field to control a position to irradiate the substrate, the deflectors being formed so that surfaces across the optical axis of the electrodes or magnetic cores have an angle of inclination to a direction of the optical axis and the angle of inclination changes in the optical axis direction.
[0022] According to a fourth aspect of the invention, there is provided a method of controlling a charged particle beam which is generated and applied to a substrate, the method comprising:
[0023] generating a lens field to focus the charged particle beam on the substrate; and
[0024] generating a deflection field which is superposed on the lens field control a position to irradiate the substrate by deflecting the charged particle beam, the deflection field being configured so that intensity thereof in a direction of the optical axis is changed in accordance with an angle with which the charged particle beam should fall onto the substrate.
[0025] According to a fifth aspect of the invention, there is provided a substrate inspection method comprising:
[0026] generating a charged particle beam to irradiate a substrate;
[0027] generating a lens field to focus the charged particle beam on the substrate;
[0028] generating a deflection field which is superposed on the lens field to control a position to irradiate the substrate by deflecting the charged particle beam, the deflection field being configured so that intensity thereof in a direction of the optical axis is changed in accordance with an angle with which the charged particle beam should fall onto the substrate; and
[0029] detecting at least one of secondary charged particles, reflected charged particles and back scattering charged particles produced from the wafer by the irradiation of the charged particle beam, in order to create a two-dimensional image representing a state in a surface of the substrate.
[0030] According to a sixth aspect of the invention, there is provided a method of manufacturing a semiconductor device comprising a substrate inspection method, the substrate inspection method including:
[0031] generating a charged particle beam to irradiate a substrate;
[0032] generating a lens field to focus the charged particle beam on the substrate;
[0033] generating a deflection field which is superposed on the lens field to deflect the charged particle beam and control a position to irradiate the substrate, the deflection field being configured so that intensity thereof in a direction of the optical axis is changed in accordance with an angle with which the charged particle beam should fall onto the substrate; and detecting at least one of secondary charged particles, reflected charged particles and back scattering charged particles produced from the wafer by the irradiation of the charged particle beam, in order to create a two-dimensional image representing a state in a surface of the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] In the accompanying drawings:
[0035] FIG. 1 is a block diagram showing a schematic configuration in one embodiment of a charged particle beam apparatus according to the present invention;
[0036] FIG. 2A is a sectional view showing one example of a deflector according to prior art;
[0037] FIGS. 2B and 2C are sectional views showing specific examples of main deflectors formed in such a manner that electrode surfaces on an optical axis side have three steps along an optical axis;
[0038] FIGS. 3A to 3 C are sectional views showing specific examples of the main deflectors in which the electrode surfaces on the optical axis side are inclined;
[0039] FIGS. 4A and 4B are sectional views showing specific examples of the main deflectors divided in an optical axis direction to configure a three-stage deflector;
[0040] FIGS. 5A and 5B are diagrams showing distribution diagrams of a magnetic field of an objective lens and electrostatic fields of the main deflectors;
[0041] FIG. 6 is a diagram explaining the relationship between changes in the distribution of the electrostatic fields of the main deflectors and an electron beam trajectory;
[0042] FIGS. 7A and 7B are sectional views showing specific examples of the main deflectors which generate electrostatic fields Ed and Ee shown in FIG. 5B ;
[0043] FIGS. 8A to 8 C are diagrams showing specific examples of a deflector having movable mechanisms coupled to electrodes;
[0044] FIGS. 9A to 9 D are sectional views showing one example of deflectors according to prior art; and
[0045] FIG. 10 is a partial configuration diagram showing one example of an electron beam lithography apparatus according to prior art.
DETAILED DESCRIPTION OF THE INVENTION
[0046] Several embodiments of the present invention will hereinafter be described in reference to the drawings. In the following embodiments, an electron beam lithography apparatus will be described which uses an electron beam as a charged particle beam to draw patterns on a wafer.
[0047] FIG. 1 is a block diagram showing a schematic configuration of one embodiment of a charged particle beam apparatus according to the present invention. An electron beam lithography apparatus 1 shown in FIG. 1 comprises an electron beam column 10 , power sources PS 1 to PS 8 , an electron beam detector 56 , an electron detector controller 58 , and a control computer 60 to control the entire apparatus.
[0048] The electron beam column 10 includes an electron gun 12 , an aperture 14 , an illumination lens 16 , a forming aperture 18 , a reduction lens 22 , a pre-main deflector 24 , a sub deflector 26 , a main deflector 28 characterizing the present embodiment, and a post-main deflector 52 . The electron gun 12 generates and accelerates an electron beam EB to irradiate a wafer W which is a sample. The aperture 14 has a rectangular or round opening, which defines a sectional shape of the electron beam EB. The forming aperture 18 has an opening with a shape corresponding to a desired pattern. The illumination lens 16 adjusts magnification so that the electron beam EB has a desired beam diameter. The reduction lens 22 reduces the beam diameter of the electron beam EB. An objective lens 54 has its focal distance adjusted so that the electron beam EB is imaged on an upper surface of the wafer W. The pre-main deflector 24 , the main deflector 28 , the post-main deflector 52 and the sub deflector 26 control the irradiation position of the electron beam EB on the wafer W. In the present embodiment, the objective lens 54 comprises a magnetic lens, the reduction lens 22 comprises an electrostatic lens, and the pre-main deflector 24 , the main deflector 28 , the post-main deflector 52 and the sub deflector 26 are all electrostatic deflectors. The pre-main deflector 24 , the main deflector 28 and the post-main deflector 52 are controlled so that a drawing area (main deflection area) is scanned with the electron beam EB referring to a position of an XY stage with regard to the wafer W mounted on the unshown XY stage, and the sub deflector 26 controls the irradiation position of the electron beam EB so that drawing is performed in sub deflection areas subdivided from the main deflection area.
[0049] Operations of elements in the electron beam column 10 are as follows.
[0050] The electron beam EB generated and accelerated by the electron gun 12 irradiates the aperture 14 . The electron beam EB which has passed through the aperture 14 moves toward the forming aperture 18 . The electron beam EB has its magnification adjusted by the illumination lens 16 to have a beam diameter which is sufficiently large and is as large as required for the opening of the forming aperture 18 . The electron beam EB starts as a pattern beam originating from the forming aperture 18 , and is reduced at the reduction lens 22 , and then passes through the electrostatic pre-main deflector 24 , the sub deflector 26 , the main deflector 28 and the post-main deflector 52 so that its irradiation position is adjusted, whereby the electron beam EB is projected on the upper surface of the wafer W just in focus by the magnetic objective lens 54 .
[0051] The power sources PS 1 to PS 8 are connected to the control computer 60 , and also connected to the electron gun 12 , the illumination lens 16 , the reduction lens 22 , the objective lens 54 , the pre-main deflector 24 , the sub deflector 26 , the main deflector 28 and the post-main deflector 52 , respectively, and the power sources PS 1 to PS 8 apply, to the elements connected to, voltages whose values are controlled in accordance with command signals supplied from the control computer 60 .
[0052] The electron beam detector 56 is disposed between the post-main deflector 52 and the wafer W, and detects at least one of a secondary electron, a reflected electron and a back scattering electron produced on the wafer W by the irradiation of the electron beam EB and supplies a detection signal to the electron detector controller 58 . The electron detector controller 58 processes the detection signal from the electron beam detector 56 to supply the control computer 60 with an image signal which is to be a two-dimensional electron image (SEM image) representing the state in the surface of the wafer W. On the basis of this image signal the control computer 60 makes adjustments such as focusing of the electron beam EB.
[0053] The electron beam EB is, in the objective lens 54 , subjected to lens force (Lorentz force) from a magnetic field excited by the objective lens 54 , and thus changes its trajectory. If the electrostatic deflector is disposed in the magnetic field of the objective lens 54 to produce an electrostatic field, the trajectory of the electron beam EB is further changed under the lens force by the magnetic field and deflecting force by the electrostatic field at the same time. This trajectory form greatly affects deflection aberration on the wafer W and the irradiation angle of the electron beam EB to the wafer W. By producing an electrostatic deflection field in accordance with magnetic field distribution of the objective lens 54 , deflection sensitivity can be further increased and the deflection aberration can be further reduced. Moreover, the incidence angle to the wafer W can be controlled such that the electron beam EB falls on the wafer W substantially perpendicularly thereto, and it is thus possible to minimize displacement of a drawing position and/or a change in a pattern shape each of which is caused by a slight change in distance between the wafer W and the objective lens 54 .
[0054] The main deflector 28 disposed in the magnetic field of the objective lens 54 in FIG. 1 is configured so as to be able to form desired electrostatic deflection field distribution in an optical axis direction. Thus, intensity of a deflection field superposed on a lens field of the objective lens 54 changes in the direction of its optical axis Ax so that the electron beam EB falls on the wafer W at a desired incidence angle while the deflection aberration is reduced.
[0055] Some of the specific configurations of the main deflector 28 will be described referring to FIGS. 2A to 5 B. FIGS. 2B to 4 B respectively show sectional views of main deflectors 282 , 284 , 290 , 292 , 294 , 302 , 304 along the optical axis direction of the electron beam EB, in a similar manner to FIGS. 9B and 9D . Sections perpendicular to the optical axis directions of the main deflectors 282 to 306 respectively shown in FIGS. 2B to 4 B and 8 A are the same as those of deflectors 820 , 822 shown in FIGS. 9A, 9C and FIGS. 9B and 9D .
[0056] The main deflectors 282 , 284 shown in FIGS. 2B and 2C are formed in such a manner that electrode surfaces on the side of the optical axis Ax have three steps along the optical axis. In the main deflector 282 of FIG. 2B , electrodes EL 282 b , EL 282 d facing each other across the optical axis Ax comprise three steps having lengths L1, L2, L3 when viewed from an object surface side in the direction of the optical axis Ax, and are formed so that a distance Φ 1 , Φ 2 , Φ 3 between the electrodes is greater in the step closer to the wafer W (image surface side). Further, in the main deflector 284 of FIG. 2C , electrodes EL 284 b , EL 284 d facing each other across the optical axis Ax comprise three steps having lengths L11, L12, L13 in the direction of the optical axis Ax when viewed from an object surface side, and are formed so that an interelectrode distance Φ 11 in the step on the object surface side is larger than an interelectrode distance Φ 12 in the middle step and so that an interelectrode distance Φ 13 in the step on the image surface side is the largest. For easier comparison with a conventional deflector, the deflector 820 shown in FIG. 9A is again shown in FIG. 2A .
[0057] The main deflectors 290 , 292 , 294 shown in FIGS. 3A to 3 C have inclined electrode surfaces on the side of the optical axis Ax. In the main deflector 290 shown in FIG. 3A , electrodes EL 290 b , EL 29 d are arranged so as to have an interelectrode distance Φa0 at the upper surfaces, and are formed so that the electrode surface on the optical axis side is inclined at an angle θa0 to the optical axis direction. In the main deflector 292 of FIG. 3B , electrodes EL 292 b , EL 292 d are arranged so as to have an interelectrode distance Φa1 at the upper surfaces, and are formed so that the electrode surface on the optical axis side is variably angled at θa1, θa2, θa3 to the optical axis Ax along with lengths La1, La2, La3 in the optical axis direction when viewed from the object surface side. Moreover, in the main deflector 294 shown in FIG. 3C , electrodes EL 294 b , EL 294 d are arranged to have an interelectrode distance Φa2 at the upper surfaces, and have inclined surfaces angled at θa11 to the optical axis Ax up to a portion having a length La11 from the object surface side, but the remainder on the image surface side (portion beyond the length La11 from the object surface side in the optical axis direction) are formed to be parallel with the optical axis.
[0058] The main deflector 302 shown in FIG. 4A is configured in such a form that the main deflector 282 shown in FIG. 2B is divided along planes each intersecting the boundaries of three steps, wherein electrodes EL 302 b 1 , EL 302 d 1 at the upper step (object surface side) have a length Lb1 in the direction of the optical axis Ax and are arranged so that the electrode surfaces on the optical axis side are separate from each other at a distance Φb1 and wherein electrodes EL 302 b 2 , EL 302 d 2 at the middle step have a length Lb2 in the direction of the optical axis Ax and are arranged so that the electrode surfaces on the optical axis side are separate from each other at a distance Φb2 and wherein electrodes EL 302 b 3 , EL 302 d 3 at the lower step (image surface side) have a length Lb3 in the direction of the optical axis Ax and are arranged so that the electrode surfaces on the optical axis side are separate from each other at a distance Φb3.
[0059] The main deflector 304 shown in FIG. 4B is configured in such a form that the main deflector 292 shown in FIG. 3B is divided along planes each intersecting boundaries of the three-stepped portions with different angles of inclination, wherein electrodes EL 304 b 1 , EL 304 d 1 at the upper step (object surface side) have a length Lb11 in the direction of the optical axis Ax and electrodes EL 304 b 2 , EL 304 d 2 at the middle step have a length Lb12 in the direction of the optical axis Ax and electrodes EL 304 b 3 , EL 304 d 3 at the lower step (image surface side) have a length Lb13 in the direction of the optical axis Ax. The electrodes EL 304 b 1 , EL 304 d 1 at the upper step are arranged so that the upper surfaces thereof are separate from each other at a distance Φb11. Further, the electrode surfaces on the optical axis side of the electrodes EL 304 b 1 , EL 304 d 1 at the upper step are inclined at an angle θb1 to the direction of the optical axis Ax, and the electrode surfaces on the optical axis side of the electrodes EL 304 b 2 , EL 304 d 2 at the middle step are inclined at an angle θb2 to the direction of the optical axis Ax, and the electrode surfaces on the optical axis side of the electrodes EL 304 b 3 , EL 304 d 3 at the lower step are inclined at an angle θb3 to the direction of the optical axis Ax.
[0060] In the various main deflectors described above, the distribution shape of the deflection electric field can be changed by adjusting the length in the optical axis direction, the distance between the electrode surfaces on the optical axis side, or the angle to the optical axis direction in the electrode surface on the optical axis side, and as a result, the incidence angle of the electron beam EB to the wafer W can be controlled for an arbitrary angle. This will be specifically described using distribution diagrams of a magnetic field and electric fields in FIGS. 5A and 5B and an electron beam trajectory diagram of FIG. 6 . Describing the main deflector 282 shown in FIG. 2B as an example, by adjusting the distances Φ1, Φ2, Φ3 between the electrodes facing each other across the optical axis Ax and the lengths L1, L2, L3 of the respective steps in the optical axis direction, the distribution shape of the electrostatic deflection field can be changed into Ea to Ee as shown in FIG. 5B , with respect to an objective lens magnetic field B in the direction along the optical axis Ax as shown in FIG. 5A . The distribution of the electrostatic deflection field superposed on the lens field of the objective lens is changed as in Ea to Ee shown in FIG. 5B , such that the trajectory of the electron beam EB is changed as shown by signs TJa to Tje of FIG. 6 , respectively.
[0061] Configuration examples of the deflector to form Ed and Ee among the five distributions of the electric fields shown in FIG. 5B are shown in FIGS. 7A and 7B . Each of deflectors 392 and 394 shown in these drawings is formed with one electrode in which the electrode surface of the optical axis side is formed in a stepped shape.
[0062] Furthermore, in the case of the main deflector 292 having the inclined electrode surface shown in FIG. 3B , the distribution of the deflection field can be changed similarly to the case of the main deflector 282 described above, by adjusting the distance Φa1 between the electrodes of the main deflector, the inclination angles θa1, θa2, θa3 to the optical axis Ax and the lengths La1, La2, La3 in the optical axis direction. Moreover, even when the main deflectors 302 , 304 of FIGS. 4A and 4B with the divided electrode are used, the three-stepped electrodes (EL 302 b 1 , EL 302 b 2 , EL 302 b 3 if the main deflector 302 is taken as an example) divided in the direction of the optical axis Ax can be controlled with the same power source, if adjustments are made for the distance between the deflection electrodes (Φb1, Φb2, Φb3), the lengths between the electrodes (Lb1, Lb2, Lb3, Lb11, Lb12, Lb13) and the inclination angles of the electrode surface (θb1, θb2, θb3).
[0063] Furthermore, as shown in FIG. 8A , the (multistep) main deflector 306 multi-divided in the direction of the optical axis Ax is used and movable mechanisms EL 402 a 1 to EL 402 h 1 , EL 402 a 2 to EL 402 h 2 respectively connected to electrodes (EL 306 a 1 to EL 306 h 1 , EL 306 a 2 to EL 306 h 2 ) are provided, such that, for example, an inside diameter (distance between optical axis side surfaces of the opposite electrodes) of the main deflector can be adjusted from Φc2 (see FIG. 8B ) to Φc12 (see FIG. 8C ) to create a desired distribution of deflection electric field in the optical axis direction.
[0064] The incidence angle of the electron beam EB to the wafer W is preferably perpendicular in exposure devices, but a greater incidence angle to the optical axis may be preferable in other fields such as electron microscopes, in which case the angle can naturally be controlled by the shape of the deflector.
[0065] Particularly, because the irradiation angle of the electron beam to a sample can be freely changed using the main deflector shown in FIG. 8A , it is possible to acquire, with high resolution, both an SEM image (top-down image) from above the wafer W which can be obtained by perpendicular incidence of the electron beam EB onto the wafer W, and an SEM image (inclined image) obliquely from above the wafer W which can be obtained by oblique incidence of the electron beam EB onto the wafer W. Further, it is also possible to obtain three-dimensional shape using right and left inclined images.
[0066] In this way, according to the present embodiment, intensity distribution of the deflection field superposed on the lens field of the objective lens can be arbitrarily changed. Further, even when mechanical locations of the deflectors in the direction along the optical axis can not be moved due to lack or absence of space resulting from mechanical arrangement, a deflection point can be moved by changing the electrode shape, thereby making it possible to optimize a deflection system.
[0067] Furthermore, by using the above-described electron beam apparatus in manufacturing processes of semiconductor devices, patterns can be drawn or inspected with high resolution while the deflection aberration on the wafer W is reduced, thus enabling the manufacture of semiconductor devices with a higher yield ratio.
[0068] While the embodiments of the present invention have been described above, the present invention is not at all limited to the above embodiments, and various modifications can naturally be made within the scope thereof.
[0069] For example, the electrostatic deflector has been used as the deflector for a charged particle beam in the embodiments described above, but the present invention is limited thereto, and a magnetic deflector may be used. When the magnetic deflector is used, ferrite may be used as magnetic cores instead of, for example, the electrodes described in FIGS. 2B to 4 B.
[0070] Furthermore, while the exposure apparatus using the electron beam as the charged particle beam has been described, the present invention can naturally be applied to all the charged particle beam apparatuses as long as they use the deflectors.
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A charged particle beam apparatus includes: a charged particle beam generator which generates a charged particle beam; a projection optical system which generates a lens field to focus the charged particle beam on an external substrate; and deflectors arranged so as to surround an optical axis of the charged particle beam; the deflectors generating a deflection field which is superposed on the lens field to deflect the charged particle beam and to control a position to irradiate the substrate, and being configured so that intensity of the deflection field in a direction of the optical axis is changed in accordance with an angle with which the charged particle beam should fall onto the substrate.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This is a continuation application of application Ser. No. 10/635,076, filed on Aug. 6, 2003, which is a continuation application of application Ser. No. 10/292,160, filed on Nov. 12, 2002, now U.S. Pat. No. 6,659,185 which is a divisional application of application Ser. No. 09/838,604, filed on Apr. 19, 2001, now U.S. Pat. No. 6,523,614.
TECHNICAL FIELD OF THE INVENTION
This invention relates in general, to the operation of a subsurface safety valve installed in the tubing of a subterranean wellbore and, in particular, to an apparatus and method for locking out a subsurface safety valve and communicating hydraulic fluid through the subsurface safety valve.
BACKGROUND OF THE INVENTION
One or more subsurface safety valves are commonly installed as part of the tubing string within oil and gas wells to protect against unwanted communication of high pressure and high temperature formation fluids to the surface. These subsurface safety valves are designed to shut in production from the formation in response to a variety of abnormal and potentially dangerous conditions.
As these subsurface safety valves are built into the tubing string, these valves are typically referred to as tubing retrievable safety valves (“TRSV”). TRSVs are normally operated by hydraulic fluid pressure which is typically controlled at the surface and transmitted to the TRSV via a hydraulic fluid line. Hydraulic fluid pressure must be applied to the TRSV to place the TRSV in the open position. When hydraulic fluid pressure is lost, the TRSV will operate to the closed position to prevent formation fluids from traveling therethrough. As such, TRSVs are fail safe valves.
As TRSVs are often subjected to years of service in severe operating conditions, failure of TRSVs may occur. For example, a TRSV in the closed position may leak. Alternatively, a TRSV in the closed position may not properly open. Because of the potential for disaster in the absence of a properly functioning TRSV, it is vital that the malfunctioning TRSV be promptly replaced or repaired.
As TRSVs are typically incorporated into the tubing string, removal of the tubing string to replace or repair the malfunctioning TRSV is required. As such, the costs associated with replacing or repairing the malfunctioning TRSV is quite high. It has been found, however, that a wireline retrievable safety valve (“WRSV”) may be inserted inside the original TRSV and operated to provide the same safety function as the original TRSV. These insert valves are designed to be lowered into place from the surface via wireline and locked inside the original TRSV. This approach can be a much more efficient and cost-effective alternative to pulling the tubing string to replace or repair the malfunctioning TRSV.
One type of WRSV that can take over the full functionality of the original TRSV requires that the hydraulic fluid from the control system be communicated through the original TRSV to the inserted WRSV. In traditional TRSVs, this communication path for the hydraulic fluid is established through a pre-machined radial bore extending from the hydraulic chamber to the interior of the TRSV. Once a failure in the TRSV has been detected, this communication path is established by first shifting a built-in lock out sleeve within the TRSV to its locked out position and shearing a shear plug that is installed within the radial bore.
It has been found, however, that operating conventional TRSVs to the locked out position and establishing this communication path has several inherent drawbacks. To begin with, the inclusion of such built-in lock out sleeves in each TRSV increases the cost of the TRSV, particularly in light of the fact that the built-in lock out sleeves are not used in the vast majority of installations. In addition, since these built-in lock out sleeves are not operated for extended periods of time, in most cases years, they may become inoperable before their use is required. Also, it has been found, that the communication path of the pre-machined radial bore creates a potential leak path for formation fluids up through the hydraulic control system. As noted above, TRSVs are intended to operate under abnormal well conditions and serve a vital and potentially lifesaving function. Hence, if such an abnormal condition occurred when one TRSV has been locked out, even if other safety valves have closed the tubing string, high pressure formation fluids may travel to the surface through the hydraulic line.
In addition, manufacturing a TRSV with this radial bore requires several high-precision drilling and thread tapping operations in a difficult-to-machine material. Any mistake in the cutting of these features necessitates that the entire upper subassembly of the TRSV be scrapped. The manufacturing of the radial bore also adds considerable expense to the TRSV, while at the same time reducing the overall reliability of the finished product. Additionally, these added expenses add complexity that must be built into every installed TRSV, while it will only be put to use in some small fraction thereof.
Attempts have been made to overcome these problems. For example, attempts have been made to communicate hydraulic control to a WRSV through a TRSV using a radial cutting tool to create a fluid passageway from an annular hydraulic chamber in the TRSV to the interior of the TRSV such that hydraulic control may be communicated to the insert WRSV. It has been found, however, that such radial cutting tools are not suitable for creating a fluid passageway from the non annular hydraulic chamber of a rod piston operated TRSVS.
Therefore, a need has arisen for an apparatus and method for establishing a communication path for hydraulic fluid to a WRSV from a failed rod piston operated TRSV. A need has also arisen for such an apparatus and method that do not require a built-in lock out sleeve in the rod piston operated TRSV. Further, a need has arisen for such an apparatus and method that do not require the rod piston operated TRSV to have a pre-machined radial bore that creates the potential for formation fluids to travel up through the hydraulic control line.
SUMMARY OF THE INVENTION
The present invention disclosed herein comprises an apparatus and method for establishing a communication path for hydraulic fluid to a wireline retrievable safety valve from a rod piston operated tubing retrievable safety valve. The apparatus and method of the present invention do not require a built-in lock out sleeve in the rod piston operated tubing retrievable safety valve. Likewise, the apparatus and method of the present invention avoid the potential for formation fluids to travel up through the hydraulic control line associated with a pre-drilled radial bore in the tubing retrievable safety valve.
In broad terms, the apparatus of the present invention allows hydraulic control to be communicated from a non annular hydraulic chamber of a rod piston operated tubing retrievable safety valve to the interior thereof so that the hydraulic fluid may, for example, be used to operate a wireline retrievable safety valve. This may become necessary when a malfunction of the rod piston operated tubing retrievable safety valve is detected and a need exists to otherwise achieve the functionality of the rod piston operated tubing retrievable safety valve.
The rod piston operated tubing retrievable safety valve of the present invention has a housing having a longitudinal bore extending therethrough. The safety valve also has a non annular hydraulic chamber in a sidewall portion thereof. A valve closure member is mounted in the housing to control fluid flow through the longitudinal bore by operating between closed and opened positions. A flow tube is disposed within the housing and is used to shift the valve closure member between the closed and opened positions. A rod piston, which is slidably disposed in the non annular hydraulic chamber of the housing, is operably coupled to the flow tube. The safety valve of the present invention also has a pocket in the longitudinal bore.
In one embodiment of the present invention a communication tool is used to establish a communication path between the non annular hydraulic chamber in a sidewall portion of the safety valve and the interior of the safety valve. In this embodiment, the communication tool has a first section and a second section that are initially coupled together using a shear pin or other suitable coupling device. A set of axial locating keys is operably attached to the first section of the tool and is engagably positionable within a profile of the safety valve. The tool includes a radial cutting device that is radially extendable through a window of the second section. For example, the radial cutting device may include a carrier having an insert removably attached thereto and a punch rod slidably operable relative to the carrier to radially outwardly extend the insert exteriorly of the second section.
The tool also includes a circumferential locating key that is operably attached to the second section of the tool. The circumferential locating key is engagably positionable within the pocket of the safety valve. Specifically, when the first and second sections of the tool are decoupled, the second section rotations relative to the first section until the circumferential locating key engages the pocket, thereby circumferentially aligning the radial cutting device with the non annular hydraulic chamber. A torsional biasing device such as a spiral wound torsion spring places a torsional load between the first and second sections such that when the first and second sections are decoupled, the second section rotates relative to the first section. A collet spring may be used to radially outwardly bias the circumferential locating key such that the circumferential locating key will engage the pocket, thereby stopping the rotation of the second section relative to the first section. Once the circumferential locating key has engaged the pocket, the radial cutting device will be axially and circumferentially aligned with the non annular hydraulic chamber. Through operation of the radial cutting device, a communication path is created from the non annular hydraulic fluid chamber to the interior of the safety valve.
As such, hydraulic fluid may now be communicated down the existing hydraulic lines to the interior of the tubing. Once this communication path exists, for example, a wireline retrievable safety valve may be positioned within the rod piston operated tubing retrievable safety valve such that the hydraulic fluid pressure from the hydraulic system may be communicated to a wireline retrievable safety valve.
In another embodiment of the present invention, a lock out and communication tool is used to lock out the safety valve and then establish a communication path between the non annular hydraulic chamber in a sidewall portion of the safety valve and the interior of the safety valve. In this embodiment, the lock out and communication tool is lowered into the safety valve until the lock out and communication tool engages the flow tube. The lock out and communication tool may then downwardly shift the flow tube, either alone or in conjunction with an increase in the hydraulic pressure acting on the rod piston, to operate the valve closure member from the closed position to the fully open position. Alternatively, if the safety valve is already in the open position, the lock out and communication tool simply prevents movement of the flow tube to maintain the safety valve in the open position. Thereafter, the lock out and communication tool interacts with the safety valve as described above with reference to the communication tool to communicate hydraulic fluid from the non annular hydraulic fluid chamber to the interior of the safety valve.
One method of the present invention that utilizes the communication tool involves inserting the communication tool into the safety valve, locking the communication tool within the safety valve with the safety valve in a valve open position, axially aligning the radially cutting device with the non annular hydraulic chamber, circumferentially aligning the radially cutting device with the non annular hydraulic chamber and penetrating the radially cutting device through the sidewall portion and into the non annular hydraulic chamber to create a communication path between the non annular hydraulic chamber and the interior of the safety valve.
In addition, a method of the present invention that utilizes the lock out and communication tool involves engaging the flow tube of the safety valve with the lock out and communication tool, retrieving the lock out and communication tool from the safety valve and maintaining the safety valve in the valve open position by preventing movement of the rod piston with an insert that is left in place within the sidewall portion when the remainder of the radial cutting tool is retracted.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, including its features and advantages, reference is now made to the detailed description of the invention, taken in conjunction with the accompanying drawings in which like numerals identify like parts and in which:
FIG. 1 is a schematic illustration of an offshore production platform wherein a wireline retrievable safety valve is being lowered into a tubing retrievable safety valve to take over the functionality thereof;
FIGS. 2A–2B are cross sectional views of successive axial sections of a rod piston operated tubing retrievable safety valve of the present invention in its valve closed position;
FIGS. 3A–3B are cross sectional views of successive axial sections of a rod piston operated tubing retrievable safety valve of the present invention in its valve open position;
FIGS. 4A–4B are cross sectional views of successive axial sections of a communication tool of the present invention;
FIGS. 5A–5B are cross sectional views of successive axial sections of a communication tool of the present invention in its running position and disposed in a rod piston operated tubing retrievable safety valve of the present invention;
FIGS. 6A–6B are cross sectional views of successive axial sections of a communication tool of the present invention in its locked position and disposed in a rod piston operated tubing retrievable safety valve of the present invention;
FIGS. 7A–7B are cross sectional views of successive axial sections of a communication tool of the present invention in its orienting position and disposed in a rod piston operated tubing retrievable safety valve of the present invention;
FIGS. 8A–8B are cross sectional views of successive axial sections of a communication tool of the present invention in its perforating position and disposed in a rod piston operated tubing retrievable safety valve of the present invention;
FIGS. 9A–9B are cross sectional views of successive axial sections of a communication tool of the present invention in its retrieving position and still substantially disposed in a rod piston operated tubing retrievable safety valve of the present invention; and
FIGS. 10A–10C are cross sectional views of successive axial sections of a lock out and communication tool of the present invention disposed in a rod piston operated tubing retrievable safety valve of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the invention.
Referring to FIG. 1 , an offshore oil and gas production platform having a wireline retrievable safety valve lowered into a tubing retrievable safety valve is schematically illustrated and generally designated 10 . A semi-submersible platform 12 is centered over a submerged oil and gas formation 14 located below sea floor 16 . Wellhead 18 is located on deck 20 of platform 12 . Well 22 extends through the sea 24 and penetrates the various earth strata including formation 14 to form wellbore 26 . Disposed within wellbore 26 is casing 28 . Disposed within casing 28 and extending from wellhead 18 is production tubing 30 . A pair of seal assemblies 32 , 34 provide a seal between tubing 30 and casing 28 to prevent the flow of production fluids therebetween. During production, formation fluids enter wellbore 26 through perforations 36 in casing 28 and travel into tubing 30 to wellhead 18 .
Coupled within tubing 30 is a tubing retrievable safety valve 38 . As is well known in the art, multiple tubing retrievable safety valves are commonly installed as part of tubing string 30 to shut in production from formation 14 in response to a variety of abnormal and potentially dangerous conditions. For convenience of illustration, however, only tubing retrievable safety valve 38 is shown.
Tubing retrievable safety valve 38 is operated by hydraulic fluid pressure communicated thereto from surface installation 40 and hydraulic fluid control conduit 42 . Hydraulic fluid pressure must be applied to tubing retrievable safety valve 38 to place tubing retrievable safety valve 38 in the open position. When hydraulic fluid pressure is lost, tubing retrievable safety valve 38 will operate to the closed position to prevent formation fluids from traveling therethrough.
If, for example, tubing retrievable safety valve 38 is unable to properly seal in the closed position or does not properly open after being in the closed position, tubing retrievable safety valve 38 must typically be repaired or replaced. In the present invention, however, the functionality of tubing retrievable safety valve 38 may be replaced by wireline retrievable safety valve 44 , which may be installed within tubing retrievable safety valve 38 via wireline assembly 46 including wireline 48 . Once in place within tubing retrievable safety valve 38 , wireline retrievable safety valve 44 will be operated by hydraulic fluid pressure communicated thereto from surface installation 40 and hydraulic fluid line 42 through tubing retrievable safety valve 38 . As with the original configuration of tubing retrievable safety valve 38 , the hydraulic fluid pressure must be applied to wireline retrievable safety valve 44 to place wireline retrievable safety valve 44 in the open position. If hydraulic fluid pressure is lost, wireline retrievable safety valve 44 will operate to the closed position to prevent formation fluids from traveling therethrough.
Even though FIG. 1 depicts a cased vertical well, it should be noted by one skilled in the art that the present invention is equally well-suited for uncased wells, deviated wells or horizontal wells. Also, even though FIG. 1 depicts an offshore operation, it should be noted by one skilled in the art that the present invention is equally well-suited for use in onshore operations.
Referring now to FIGS. 2A and 2B , therein is depicted cross sectional views of successive axial sections a tubing retrievable safety valve embodying principles of the present invention that is representatively illustrated and generally designated 50 . Safety valve 50 may be connected directly in series with production tubing 30 of FIG. 1 . Safety valve 50 has a substantially cylindrical outer housing 52 that includes top connector subassembly 54 , intermediate housing subassembly 56 and bottom connector subassembly 58 which are threadedly and sealing coupled together.
It should be apparent to those skilled in the art that the use of directional terms such as top, bottom, above, below, upper, lower, upward, downward, etc. are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure. As such, it is to be understood that the downhole components described herein may be operated in vertical, horizontal, inverted or inclined orientations without deviating from the principles of the present invention.
Top connector subassembly 54 includes a substantially cylindrical longitudinal bore 60 that serves as a hydraulic fluid chamber. Top connector subassembly 54 also includes a profile 62 and a radially reduced area 64 . In accordance with an important aspect of the present invention, top connector subassembly 54 has a pocket 66 . In the illustrated embodiment, the center of pocket 66 is circumferentially displaced 180 degrees from longitudinal bore 60 . It will become apparent to those skilled in the art that pocket 66 could alternatively be displaced circumferentially from longitudinal bore 60 at many other angles. Likewise, it will become apparent to those skilled in the art that more than one pocket 66 could be used. In that configuration, the multiple pockets 66 could be displaced axially from one another along the interior surface of top connector subassembly 54 .
Hydraulic control pressure is communicated to longitudinal bore 60 of safety valve 50 via control conduit 42 of FIG. 1 . A rod piston 68 is received in slidable, sealed engagement against longitudinal bore 60 . Rod piston 68 is connected to a flow tube adapter 70 which is threadedly connected to a flow tube 72 . Flow tube 72 has profile 74 and a downwardly facing annular shoulder 76 .
A flapper plate 78 is pivotally mounted onto a hinge subassembly 80 which is disposed within intermediate housing subassembly 56 . A valve seat 82 is defined within hinge subassembly 80 . It should be understood by those skilled in the art that while the illustrated embodiment depicts flapper plate 78 as the valve closure mechanism of safety valve 50 , other types of safety valves including those having different types of valve closure mechanisms may be used without departing from the principles of the present invention, such valve closure mechanisms including, but not limited to, rotating balls, reciprocating poppets and the like.
In normal operation, flapper plate 78 pivots about pivot pin 84 and is biased to the valve closed position by a spring (not pictured). When safety valve 50 must be operated from the valve closed position, depicted in FIGS. 2A–2B , to the valve opened position, depicted in FIGS. 3A–3B , hydraulic fluid enters longitudinal bore 60 and acts on rod piston 68 . As the downward hydraulic force against rod piston 68 exceeds the upward bias force of spiral wound compression spring 86 , flow tube 72 moves downwardly with rod piston 68 . As flow tube 72 continues to move downwardly, flow tube 72 contacts flapper closure plate 78 and forces flapper closure plate 78 to the open position.
When safety valve 50 must be operated from the valve open position to the valve closed position, hydraulic pressure is released from conduit 42 such that spring 86 acts on shoulder 76 and upwardly bias flow tube 72 . As flow tube 72 is retracted, flapper closure plate 78 will rotate about pin 84 and seal on seat 82 .
If safety valve 50 becomes unable to properly seal in the closed position or does not properly open after being in the closed position, it is desirable to reestablish the functionality of safety valve 50 without removal of tubing 30 . In the present invention this is achieved by inserting a lock out and communication tool into the central bore of safety valve 50 .
Referring now to FIGS. 4A–4B , therein is depicted cross sectional views of successive axial sections a lock out and communication tool embodying principles of the present invention that is representatively illustrated and generally designated 100 . Communication tool 100 has an outer housing 102 . Outer housing 102 has an upper subassembly 104 that has a radially reduced interior section 106 . Outer housing 102 also has a key retainer subassembly 108 including windows 110 and a set of axial locating keys 112 . In addition, outer housing 102 has a lower housing subassembly 114 .
Slidably disposed within outer housing 102 is upper mandrel 116 that is securably coupled to expander mandrel 118 by attachment members 120 . Upper mandrel 116 carries a plurality of dogs 122 . Partially disposed and slidably received within upper mandrel 116 is a fish neck 124 including a fish neck mandrel 126 and a fish neck mandrel extension 128 . Partially disposed and slidably received within fish neck mandrel 126 and fish neck mandrel extension 128 is a punch rod 130 . Punch rod 130 extends down through communication tool 100 and is partially disposed and selectively slidably received within main mandrel 132 .
Punch rod 130 and main mandrel 132 are initially fixed relative to one another by shear pin 134 . Main mandrel 132 is also initially fixed relative to lower housing subassembly 114 of outer housing 102 by shear pins 136 . Shear pins 136 not only prevent relative axial movement between main mandrel 132 and lower housing subassembly 114 but also prevent relative rotation between main mandrel 132 and lower housing subassembly 114 . A torsional load is initially carried between main mandrel 132 and lower housing subassembly 114 . This torsional load is created by spiral wound torsion spring 138 .
Attached to main mandrel 132 is a circumferential locating key 140 on the upper end of collet spring 142 . Circumferential locating key 140 includes a retaining pin 144 that limits the outward radial movement of circumferential locating key 140 from main mandrel 132 . Disposed within main mandrel 132 is a carrier 146 that has an insert 148 on the outer surface thereof. Insert 148 includes an internal fluid passageway 150 . Carrier 146 and insert 148 are radially extendable through window 152 of main mandrel 132 . Main mandrel 132 has a downwardly facing annual shoulder 154 .
The operation of communication tool 100 of the present invention will now be described relative to safety valve 50 of the present invention with reference to FIGS. 5A–5B , 6 A– 6 B, 7 A– 7 B, 8 A– 8 B and 9 A– 9 B. In FIGS. 5A–5B , communication tool 100 is in its running configuration. Communication tool 100 is positioned within the longitudinal central bore of safety valve 50 . As communication tool 100 is lowered into safety valve 50 , downwardly facing annular shoulder 154 of main mandrel 132 contacts profile 74 of flow tube 72 . Main mandrel 132 may downwardly shift flow tube 72 , either alone or in conjunction with an increase in the hydraulic pressure within longitudinal chamber 60 , operating flapper closure plate 78 from the closed position, see FIGS. 2A–2B , to the fully open position, see FIGS. 3A–3B . Alternatively, if safety valve 50 is already in the open position, main mandrel 132 simply holds flow tube 72 in the downward position to maintain safety valve 50 in the open position. Communication tool 100 moves downwardly relative to outer housing 52 of safety valve 50 until axial locating keys 112 of communication tool 100 engage profile 62 of safety valve 50 .
Once axial locating keys 112 of communication tool 100 engage profile 62 of safety valve 50 , downward jarring on communication tool 100 shifts fish neck 124 along with fish neck mandrel 126 , fish neck mandrel extension 128 , upper mandrel 116 and expander mandrel 118 downwardly relative to safety mandrel 50 and punch rod 130 . This downward movement shifts expander mandrel 118 behind axial locating keys 112 which locks axial locating keys 112 into profile 62 , as best seen in FIGS. 6A–6B .
In this locked configuration of communication tool 100 , dogs 122 are aligned with radially reduced interior section 106 of upper housing subassembly 104 . As such, additional downward jarring on communication tool 100 outwardly shifts dogs 122 which allows fish neck mandrel extension 128 to move downwardly. This allows the lower surface of fish neck 124 to contact the upper surface of punch rod 130 . Continued downward jarring with a sufficient and predetermined force shears pins 136 , as best seen in FIGS. 7 A– 7 B. When pins 136 shear, this allows punch rod 130 and main mandrel 132 to move axially downwardly relative to housing 102 and expander mandrel 118 of communication tool 100 and safety valve 50 . This downward movement axially aligns carrier 146 and insert 148 with radially reduced area 64 and axially aligns circumferential locating key 140 with pocket 66 of safety valve 50 .
In addition, when pins 136 shear, this allows punch rod 130 and main mandrel 132 to rotate relative to housing 102 and expander mandrel 118 of communication tool 100 and safety valve 50 due to the torsional force stored in torsion spring 138 . This rotational movement circumferentially aligns carrier 146 and insert 148 with longitudinal bore 60 of safety valve 50 . This is achieved due to the interaction of circumferential locating key 140 and pocket 66 . Specifically, as punch rod 130 and main mandrel 132 rotate relative to safety valve 50 , collet spring 142 radially outwardly biases circumferential locating key 140 . Thus, when circumferential locating key 140 becomes circumferentially aligned with pocket 66 , circumferential locating key 140 moves radially outwardly into pocket 66 stopping the rotation of punch rod 130 and main mandrel 132 relative to safety valve 50 . By axially and circumferentially aligning circumferential locating key 140 with pocket 66 , carrier 146 and insert 148 become axially and circumferentially aligned with longitudinal bore 60 of safety valve 50 .
Once carrier 146 and insert 148 are axially and circumferentially aligned with longitudinal bore 60 of safety valve 50 , communication tool 100 is in its perforating position, as depicted in FIGS. 8A–8B . In this configuration, additional downward jarring on communication tool 100 , of a sufficient and predetermined force, shears pin 134 which allow punch rod 130 to move downwardly relative to main mandrel 132 . As punch rod 130 move downwardly, insert 148 penetrates radially reduced region 64 of safety valve 50 . The depth of entry of insert 148 into radially reduced region 64 is determined by the number of jars applied to punch rod 130 . The number of jars applied to punch rod 130 is predetermined based upon factors such as the thickness of radially reduced region 64 and the type of material selected for outer housing 52 . The thickness of the radially reduced region 64 is less than 30 percent of the thickness between the exterior sidewall of the housing 52 and the longitudinal bore 60 . Preferably, the thickness of this region 64 is between 15 and 25 percent of the thickness between the exterior sidewall of the housing 52 and the longitudinal bore 60 .
With the use of communication tool 100 of the present invention, fluid passageway 150 of insert 148 provides a communication path for hydraulic fluid from longitudinal bore 60 to the interior of safety valve 50 . Once insert 148 is fixed within radially reduced region 64 , communication tool 100 may be retrieved to the surface, as depicted in FIGS. 9A–9B . In this configuration, punch rod 130 has retracted from behind carrier 146 , fish neck mandrel extension 128 has retracted from behind keys 106 and expander mandrel 118 has retracted from behind axial locating keys 112 which allows communication tool 100 to release from safety valve 50 . Insert 148 now prevents the upward movement of rod piston 68 and flow tube 72 which in turn prevents closure of flapper closure plate 78 , thereby locking out safety valve 50 . In addition, flow passageway 150 of insert 148 allow for the communication of hydraulic fluid from longitudinal bore 60 to the interior of safety valve 50 which can be used, for example, to operate a wireline retrievable subsurface safety valve that is inserted into locked out safety valve 50 .
Referring now to FIGS. 10A–10C , therein is depicted cross sectional views of successive axial sections a lock out and communication tool embodying principles of the present invention that is representatively illustrated and generally designated 200 . The communication tool portion of lock out and communication tool 200 has an outer housing 202 . Outer housing 202 has an upper subassembly 204 that has a radially reduced interior section 206 . Outer housing 202 also has a key retainer subassembly 208 including windows 210 and a set of axial locating keys 212 . In addition, outer housing 202 has a lower housing subassembly 214 .
Slidably disposed within outer housing 202 is upper mandrel 216 that is securably coupled to expander mandrel 218 by attachment members 220 . Upper mandrel 216 carries a plurality of dogs 222 . Partially disposed and slidably received within upper mandrel 216 is a fish neck 224 including a fish neck mandrel 226 and a fish neck mandrel extension 228 . Partially disposed and slidably received within fish neck mandrel 226 and fish neck mandrel extension 228 is a punch rod 230 . Punch rod 230 extends down through lock out and communication tool 200 and is partially disposed and selectively slidably received within main mandrel 232 and main mandrel extension 260 of the lock out portion of lock out and communication tool 200 .
Punch rod 230 and main mandrel 232 are initially fixed relative to one another by shear pin 234 . Main mandrel 232 is also initially fixed relative to lower housing subassembly 214 of outer housing 202 by shear pins 236 . Shear pins 236 not only prevent relative axial movement between main mandrel 232 and lower housing subassembly 214 but also prevent relative rotation between main mandrel 232 and lower housing subassembly 214 . A torsional load is initially carried between main mandrel 232 and lower housing subassembly 214 . This torsional load is created by spiral wound torsion spring 238 .
Attached to main mandrel 232 is a circumferential locating key 240 on the upper end of collet spring 242 . Circumferential locating key 240 includes a retaining pin 244 that limits the outward radial movement of circumferential locating key 240 from main mandrel 232 . Disposed within main mandrel 232 is a carrier 246 that has an insert 248 on the outer surface thereof. Insert 248 includes an internal fluid passageway 250 . Carrier 246 and insert 248 are radially extendable through window 222 of main mandrel 232 . Main mandrel 232 is threadedly attached to main mandrel extension 260 . In the illustrated embodiment, the lock out portion of lock out and communication tool 200 also includes a lug 262 with contacts upper shoulder 74 , a telescoping section 264 and a ratchet section 266 . In addition, a piston the lock out portion of lock out and communication tool 200 includes a dimpling member 268 that is radially extendable through a window 270 .
In operation, as lock out and communication tool 200 is positioned within the longitudinal central bore of safety valve 50 as described above with reference to tool 100 , flapper closure plate 78 is operated from the closed position, see FIGS. 2A–2B , to the fully open position, see FIGS. 3A–3B . Lock out and communication tool 200 moves downwardly relative to outer housing 52 of safety valve 50 until axial locating keys 212 of lock out and communication tool 200 engage profile 62 of safety valve 50 and are locked therein.
In this locked configuration of lock out and communication tool 200 , shears pins 236 may be sheared in response to downward jarring which allows punch rod 230 and main mandrel 232 to move axially downwardly relative to housing 202 and expander mandrel 218 of lock out and communication tool 200 and safety valve 50 . As explained above, this downward movement axially aligns carrier 246 and insert 248 with radially reduced area 64 . In addition, circumferential locating key 240 is both axially and circumferentially aligned with pocket 66 of safety valve 50 .
By axially and circumferentially aligning circumferential locating key 240 with pocket 66 , carrier 246 and insert 248 become axially and circumferentially aligned with longitudinal bore 60 of safety valve 50 such that additional downward jarring on lock out and communication tool 200 of a sufficient and predetermined force shears pin 234 which allow punch rod 230 to move downwardly relative to main mandrel 232 and main mandrel extension 260 . As punch rod 230 move downwardly, insert 248 penetrates radially reduced region 64 of safety valve 50 . Further travel of punch rod 230 downwardly relative to main mandrel 232 and main mandrel extension 260 causes dimpling member 268 to contact and form a dimple in the inner wall of safety valve 50 which prevents upward travel of piston 68 after lock out and communication tool 200 is retrieved from safety valve 50 .
The unique interaction of lock out and communication tool 200 of the present invention with safety valve 50 of the present invention thus allows for the locking out of a rod piston operated safety valve and for the communication of its hydraulic fluid to operate, for example, an insert valve.
While this invention has been described with a reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.
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A tubing retrievable safety valve ( 50 ) having a non annular hydraulic chamber ( 60 ) in a sidewall portion thereof is operable to received a communication tool ( 100 ) therein such that relative rotation between at least a portion of the communication tool ( 100 ) and the tubing retrievable safety valve ( 50 ) is substantially prevented. The communication tool ( 100 ) is operable to create a fluid passageway ( 150 ) between the non annular hydraulic chamber ( 60 ) and the interior of the tubing retrievable safety valve ( 50 ) by penetrating through the sidewall portion and into the non annular hydraulic chamber ( 60 ). Thereafter, when a wireline retrievable safety valve ( 44 ) is positioned within the tubing retrievable safety valve ( 50 ), hydraulic fluid is communicatable thereto through the fluid passageway ( 150 ).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to soluble nanosize particles which comprise platinum alone or platinum together with other metals of the platinum group and are stabilized by protective colloids, and also to a process for preparing them by the sol process, wherein the protective colloids consist completely or partly of polymers which bear side chains containing a sulfobetaine group and can be degraded by hydrolysis. The invention further relates to catalysts produced from the abovementioned nanosize particles and to their use for electrodes of membrane fuel cells.
2. Description of the Prior Art
For reasons of declining energy reserves and of environmental protection, electric drives for the operation of motor vehicles are of great importance as a future-oriented alternative to conventional internal combustion engines. A considerable technical problem is still presented by the provision of electric energy onboard the vehicle. Vehicles powered by rechargeable batteries have only a small storage capacity and therefore allow only limited ranges. In contrast, fuel cells which generate the electric energy onboard the vehicle from a chemical fuel offer, due to the high storage density of the chemical energy carrier and because of their superior efficiency in energy conversion, comparable ranges to those of present-day internal combustion engines.
Fuel cells based on platinum catalysts and on polymeric solid electrolyte membranes have considerable advantages for powering vehicles. Due to their mode of construction, membrane fuel cells are referred to as “polymer electrode membrane fuel cells”, PEMFC or PEFC.
Although a highly developed prior art for membrane fuel cells already exists, a further improvement in the performance together with a reduced usage of the expensive noble metal platinum is required for economic use of production-line electric drives in motor vehicles.
The key part of a PEMFC is a gastight but proton-permeable membrane of a cation-exchange polymer, i.e. a polymer to which negatively charged, acid groups are bound. Both sides of the membrane are covered with a thin layer of a mixture of nanosize platinum particles and fine particles of electrically conductive carbon. The platinum acts as catalyst for the two electrochemical substeps, namely oxidation of the fuel at the anode and reduction of oxygen at the cathode. The outer covering of the platinum/carbon layer in each case comprises the current collector, namely a gas-permeable nonwoven or paper made of electrically conductive carbon fibers. Together with the platinum/carbon layer, the current collector forms the anode or cathode, respectively, of the fuel cell. The complete assembly of all components, anode-membrane-cathode, is referred to as a “membrane electrode assembly” (MEA).
The transport of the gaseous reactants to the electrodes, i.e. of the fuel to the anode and of the atmospheric oxygen to the cathode, occurs backward through the gas-permeable current collector. The anode current collector serves to carry away the electrons which are liberated in the oxidation of the fuel. The cathode current collector serves to supply electrons which are required at the cathode for reduction of the oxygen. The external electronic charge flow from the anode to the cathode corresponds to the external electric circuit with the power consumer located in between. Internal, protic charge transport occurs by protons formed at the anode due to oxidation of the fuel being transported by means of the negatively charged solid-state ions through the cation-exchange membrane to the cathode and there combining with the reduction products of the oxygen to form water.
J. Electrochem. Soc. 143 (1996) L7 describes platinum colloids on a highly porous carbon support. The platinum particles are generated on the support by the impregnation method.
WO 91/19 566 discloses alloys of noble metals with cobalt, chromium and/or vanadium on carbon supports, which are produced by stepwise deposition of the metals on the support and subsequent calcination.
EP-A-0 106 197 discloses catalysts comprising, inter alia, thin, flat platinum crystallites on a graphite support and a process for preparing them in which they are deposited electrochemically on the support.
DE-A-27 19 006 claims catalysts in which the cations of the catalytically active metal are bound to the carbon support via acid groups and the catalyst is used without prior reduction in the process to be catalyzed.
It is also known that heterogeneous catalysts for chemical and electrochemical processes, whose active centers consist of a metal, in particular a noble metal, can be prepared on the basis of a sol process. Here, a sol of the appropriate catalytically active metal or, if desired, a plurality of metals is firstly produced in a separate process step and the dissolved or solubilized nanosize particles are subsequently immobilized on the support. The general advantage of the sol process is the high dispersion of the particles which can be achieved, with the lower limit at present extending, for example, to about 1 nanometer in the case of platinum.
General descriptions of these methods may be found, inter alia, in (a) B. C. Gates, L. Guczi, H. Knozinger, Metal Clusters in Catalysis, Elsevier, Amsterdam, 1986; (b) J. S. Bradley in Clusters and Colloids, VCH, Weinheim 1994, p. 459-544; (c) B. C. Gates, Chem. Rev. 1995, 95, 511-522.
The sols are generally produced using a stabilizer, in particular when further-processable sols having a metal concentration of 0.1% or more are required. The catalyst envelopes the metal particles and prevents agglomeration of the particles by means of electrostatic or steric repulsion. In addition, the stabilizer influences the solubility of the particles to some degree.
As stabilizers, it is possible to use both low molecular weight compounds and polymeric compounds.
Platinum sols comprising low molecular weight, mainly surface-active stabilizers and their use for producing catalysts for fuel cells have been described many times:
EP-A-0 672 765 discloses the electrochemical preparation of platinum hydrosols using cationic and betainic stabilizers and also catalysts produced therefrom which are said to be suitable, inter alia, for fuel cells.
DE-A-44 43 701 discloses platinum-containing coated catalysts which are said to be suitable for fuel cells. Here, the Pt particles form a shell which Th extends into the support particle to a depth of up to 200 nm. A process for producing them via a cationically stabilized hydrosol is also claimed.
DE-A44 43 705 claims the preparation of surfactant-stabilized metal colloids as precursors for heterogeneous catalysts.
Platinum sols comprising polymeric stabilizers and their use for producing catalysts, inter alia for fuel cells, have likewise been described. These involve the use of, for example, polyacrylic acid, polyvinyl alcohol or poly(N-vinylpyrrolidone). Apart from the purpose of stabilizing the sol concerned, the polymers mentioned have achieved no functional importance.
J. Am. Chem. Soc. 101 (1979) 7214 describes platinum colloids for the photolysis of water which have a hydrodynamic diameter of from 22 to 106 nm and are stabilized by means of polyvinyl alcohol.
Chemistry Letters 1981 793 describes polymer-supported platinum colloids which have a particle size of from about 1.5 to 3.5 nm and have been prepared using poly(N-vinylpyrrolidone) or polyvinyl alcohol.
Science 272 (1996) 1924 describes platinum particles stabilized with sodium polyacrylate. It has been found that the edge length and the crystal shape of the particles depends on the ratio of the amounts of stabilizer and platinum.
Furthermore, it has also been shown that the presence of a stabilizer can be unnecessary if the sol is produced in the presence of a support. DE-A-25 59 617 discloses the production of catalysts by converting a platinum salt into a metastable colloid in the presence of a support so that the colloid is deposited on the support.
U.S. Pat. No. 4,937,220 discloses a process for reducing recrystallization by applying a dispersion of different crystal sizes and shapes to the carbon support.
DE-A-2848138 teaches a process for reducing recrystallization by depositing porous carbon on and around the platinum crystallites located on the carbon particles.
U.S. Pat. No. 4,610,938 discloses electrodes for fuel cells whose catalytically active surface is adjoined by a layer of a fluorinated polymer bearing acid groups.
U.S. Pat. No. 4,876,115 describes the coating of carbon supports which are laden with platinum particles of 2-5 nanometers in diameter in an amount of about 0.35 mg/cm 2 of Pt with a perfluorinated cation-exchange resin for increasing the proton conductivity.
In practice, it has not been fully possible to achieve electrochemical processes and mass transfer processes, which occur in both electrode layers of a membrane fuel cell, such that low losses occur. As a result of insufficient contact with the electron- and/or proton-conducting phase, a considerable part of the platinum used is not able to function or able to function only to a restricted extent, which finally leads to reduced performance of the cell and in conventional systems is compensated for by very high platinum loadings. In particular, it has been found that more platinum is required than would be necessary per se to achieve a particular electric output. In practice, the platinum usage is from about 0.5 to 4 mg/cm 2 of membrane area. This has hitherto corresponded to several 100 g of platinum for a practical vehicle having a motor power of 40-50 kW. Some scientific publications and patents have already disclosed considerably lower platinum usages in the order of from 0.1 to 0.2 mg/cm 2 . However, fuel cells used under realistic conditions of road traffic still require a significantly higher platinum usage.
One critical reason for the increased platinum requirement is the process hitherto predominantly employed for preparing the platinum/carbon mixture. In this process, the solution of a reducible or precipitable platinum compound is applied to the carbon support by impregnation or spraying. The platinum compound is subsequently converted into finely divided platinum or platinum oxide particles by precipitation and/or chemical reduction, frequently resulting in formation of relatively large particles having sizes up to some 10 to 100 nm. This results in a reduction in the catalytic activity due to the reduction in the specific platinum surface area.
It is also known that a platinum catalyst on a carbon support loses surface area under the customary operating conditions, i.e. at an elevated temperature.
The above-described relationships between, firstly, the particle size of the metal centers and their catalytic activity and, secondly, the established tendency for the particle size to increase by agglomeration require precise control of the size of the particles and of the microstructure of the matrix surrounding them. The necessary degree of these properties has hitherto not been able to be achieved by conventional preparation techniques.
SUMMARY OF THE INVENTION
In view of the prior art, it is an object of the invention firstly to achieve high dispersion of the catalytically active platinum centers, secondly to ensure unhindered transport of starting materials, products and also protons and electrons and thirdly to reduce the recrystallization of the platinum particles to form larger particles on the carbon support.
It has surprisingly been found that the use of polymeric betaines gives sols having particularly small particles with a diameter of typically 1 nanometer. This achieves a very high dispersity and thus sparing use of the expensive noble metals.
The invention provides nanosize particles which comprise platinum alone or platinum and other metals of the platinum group and are embedded in a protective colloid which comprises polymeric betaines and can be degraded by hydrolysis.
The invention also provides a process for immobilizing the abovementioned nanosize particles in a fine, uniform distribution on the surface or in surface regions of a carbon support and, if desired, subsequently to remove the protective colloid completely or partially by hydrolytic degradation.
Furthermore, the invention provides a process for preparing nanosize particles which comprise platinum alone or platinum and other metals of the platinum group and are embedded in a protective colloid which comprises polymeric betaines and can be degraded by hydrolysis, by reacting a platinum compound alone or a platinum compound together with one or more compounds of metals selected from the group consisting of rhodium, ruthenium, iridium and palladium with a reducing agent in water or a solvent, wherein the reduction is carried out in the presence of a polymeric betaine or the polymeric betaine is added to the sol after the reduction step, and, if desired, the stabilized sol is subsequently purified by reprecipitation and/or concentrated by evaporation.
The invention further provides a process for producing catalysts for fuel cells, which comprises bringing a finely divided support, for example of carbon, carbon black or graphite, into contact with a sol of the abovementioned nanosize particles, separating the catalyst formed from the liquid phase by filtration or centrifugation and, if desired, subsequently removing the protective colloid completely or partially from the catalyst by treatment with a base.
The nanosize particles provided by the invention or the catalysts obtained therefrom are suitable in principle for the anode and the cathode of a membrane fuel cell. However, a different structuring of nanosize particles or catalysts for the anode and the cathode for the purposes of the invention is not ruled out, but may be advantageous in individual cases.
The sols of the nanosize particles are, preferably after prior purification and concentration, applied to the support, with the stabilizer envelope being essentially retained.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a preferred embodiment of the invention, the polymeric betaine envelope is completely or partially removed from the catalytically active centers after immobilization. This measure aids the transport of electrons and/or protons from or to the centers. The polymeric betaines used for this purpose according to the invention are, for example, derivatives of polyacrylic acid in which the side chains bearing betaine groups are linked to the main polymer chain via carboxylic ester groups and/or carboxamide groups. Degradation is achieved by hydrolysis of the carboxylic ester group or carboxamide group. The dissociation can be carried out by treating the catalyst with a base, for example an alkali metal hydroxide or ammonia.
The soluble nanosize particles obtainable according to the invention are particles having a diameter of from about 0.5 to 3 nanometers, preferably from about 1 to 2 nanometers, based on the metal core. The particles are soluble in water or an organic solvent, with “soluble” also meaning “solubilizable”, i.e. sol-forming.
In the preparation according to the invention of nanosize particles, the starting materials used are the intended metals in the form of soluble compounds, in particular water-soluble compounds, for example hexachloroplatinic(IV) acid hydrate, hexachloroiridic(IV) acid hydrate, palladium(II) acetate, iridium(III) acetylacetonate, ruthenium(III) acetylacetonate, ruthenium(III) nitrate or rhodium(III) chloride hydrate. The metal compounds are used in a concentration of from about 0.1 to 100 g per liter, preferably from 1 to 50 g per liter, based on the solvent.
The polymeric betaines used according to the invention are made up of an essentially unbranched polymethylene main chain and various side chains bearing betaine groups.
For example, the side chains comprise an alkylene radical having from about 2 to 12 carbon atoms, preferably from 2 to 4 carbon atoms, and bear a betaine group at the end. The side chain is linked to the main chain via a carboxylic ester group or via a carboxamide group. In polymers of the abovedescribed type, the side chain can be split off by simple means, for example by reaction with a base.
The side chain can also be formed by an N-containing, heterocyclic ring system, for example a pyridine ring, where the nitrogen atom of the betaine group belongs to the ring system and the linkage to the main chain is via carbon or possibly further nitrogen atoms of the ring system.
The betaine group may consist of a carbobetaine, —N + R 1 R 2 —(—CH 2 —) n —CO 2 − , a phosphobetaine, —N + R 1 R 2 —(—CH 2 —) n —PO 3 − or preferably a sulfobetaine, —N + R 1 R 2 —(—CH 2 —) n —SO 3 − , where R 1 and R 2 are identical or different alkyl radicals having from 1 to 6 carbon atoms and n is 1, 2 or 3.
Examples of suitable polymers are poly[N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl)ammonium betaine] of formula 1:
poly[N,N-dimethyl-N-methacrylamidopropyl-N-(3-sulfopropyl)ammonium betaine] of formula 2:
poly[1-(3′-sulfopropyl)-2-vinylpyridinium betaine] of formula 3:
The above-described polymers are prepared by free-radical polymerization from the corresponding monomers which are commercially available. The polybetaines have degrees of polymerization of from about 50 to 10,000, preferably from 100 to 1000.
It is also possible to use copolymers made up of various monomers from the above-described categories.
Furthermore, it is possible to use copolymers made up of the above-described monomers containing betaine groups together with further monomers such as acrylic acid, acrylic esters, acrylamides, vinyl carboxylates, vinyl alkyl ethers, N-vinylpyridine, N-vinyl pyrrolidone or N-vinylcarboxamides.
In the process of the invention, the polybetaines are used in amounts of from 5 to 2000% by weight, preferably from 20 to 400% by weight, based on the metal or metals.
The process of the invention is carried out in water or in a mixture of water and a (or a plurality of) water-miscible organic solvent(s) or in the absence of water in an organic-solvent.
Examples of suitable solvents are methanol, ethanol, ethylene glycol, tetrahydrofuran, dimethoxyethane, acetone, N-methylpyrrolidone, dimethyl-formamide and dimethylacetamide. The sols are preferably prepared in water (hydrosols) or in water with addition of from 1 to 50% by weight, preferably from 5 to 25% by weight, of an organic solvent.
Suitable reducing agents are all customary reducing agents which have a sufficiently negative reduction potential, for example hydrogen, sodium borohydride, ethanol, ethylene glycol and hydroxymethanesulfinic acid sodium salt. The preferred reducing agent is hydroxymethanesulfinic acid sodium salt (Rongalit®). The reducing agent is generally used in a stoichiometric amount based on the metal compound(s), but preferably in a certain excess. The excess can be, for example, from 10 to 100%.
The preparation of the sols is carried out at temperatures of from 0 to 200° C., preferably from 20 to 100° C. The components can generally be added in any order. It is advantageous to aid mixing by means of stirring. In the preferred procedure, the reducing agent is added last. If the polymeric betaine is added only after the reduction, the addition has to be carried out before agglomeration commences.
The platinum-polybetaine complexes present in the sols of the invention are novel compounds of relatively uniform composition. Examination of the particles by transmission electron microscopy (TEM) indicated a very narrow size distribution. Typically 90% of the particles deviate by less than 20% from the mean diameter. The diameter of the metal core depends to some degree on the type and amount of stabilizer used. It is generally less than 3 nanometers, usually less than 2 nanometers. In most cases, the diameter of the metal core is about 1 nanometer.
For further processing of the sols to give catalysts, i.e. for producing the platinum/carbon black mixture, metal concentrations of at least 10 g/liter are generally desired. The sols obtained according to the invention can, if desired, be evaporated by gently distilling off water and/or the solvent. If required, the sols obtained according to the invention can be purified by reprecipitation in a manner known per se and, if desired, concentrated at the same time. The precipitation of a colloidally dissolved platinum-cation-exchange polymer complex can be carried out by addition of acetone or isopropanol. The platinum-cation-exchange polymer gels obtained can be redissolved in water. The metal concentrations which can be achieved in this way are from 50 to 100 g/liter.
To produce catalysts, the aqueous sols prepared as described above are brought into contact with a finely pulverulent, conductive carbon support and the liquid phase is subsequently separated off. In this procedure, the platinum-cation-exchange polymer complex is immobilized on the support particles. It has been found that the platinum-cation-exchange polymer complexes of the invention are preferentially deposited on the surface or in surface regions of the support and have good adhesion to the support.
The support comprises finely divided carbon, carbon black or graphite. Preference is given to using specific, electrically conductive carbons (carbon black) which are commercially available, for example ®Vulcan XC 72R.
The carbon supports to be used can be additionally treated with materials, for example with proton-conducting polymers, before or after loading with the nanosize Pt particles of the invention. This procedure is described in principle in U.S. Pat. No. 4,876,115.
One way of carrying out the loading of the carbon support is to introduce the sol with mixing into a suspension of the support in water or a water/alcohol mixture, to stir the suspension further and to isolate the platinum/carbon mixture by filtration or centrifugation.
EXAMPLE 1
1000 ml of deionized water were placed in a 2 l conical flask. 2.50 g (about 5 mmol) of hexachloroplatinic acid hydrate (platinum content about 40%) were added thereto and 5% strength ammonia solution was added dropwise until a pH of 7 had been reached. At 95° C. while stirring, 1.00 g of poly[N,N-di-methyl-N-methacryloxyethyl-N-(3-sulfopropyl)ammonium betaine] of formula 1 and subsequently a solution of 2.50 g (21 mmol) of hydroxymethanesulfinic acid sodium salt dihydrate (Rongalit®) in 20 ml of deionized water were added thereto. The mixture was allowed to cool to room temperature and allowed to stand for 8 hours, the hydrosol was admixed with 1000 ml of acetone, stirred for 5 minutes and the precipitate formed was allowed to settle for 15 hours. After decanting off most of the supernatant liquid, the remainder was centrifuged at 7000 rpm for 15 minutes. The centrifuge residue was dissolved completely in water to 20.0 g, forming a dark reddish brown sol.
EXAMPLE 2
1000 ml of deionized water were placed in a 2 l conical flask. 2.50 g (about 5 mmol) of hexachloroplatinic acid hydrate (platinum content about 40%) were added thereto and 5% strength ammonia solution was added dropwise until a pH of 7 had been reached. At 95° C. while stirring, 1.00 g of poly[N,N-di-methyl-N-methacrylamidopropyl-N-(3-sulfopropyl)ammonium betaine] of formula 2 was added thereto and the mixture was subsequently processed further as described in Example 1. Work-up gave 20.0 g of a dark reddish brown sol.
EXAMPLE 3
1000 ml of deionized water were placed in a 2 l conical flask. 2.50 g (about 5 mmol) of hexachloroplatinicacid hydrate (platinum content about40%)were added thereto and 5% strength ammonia solution was added dropwise until a pH of 7 had been reached. At 95° C. while stirring, 1.00 g of poly[1-(3′-sulfopropyl)-2-vinylpyridinium betaine of formula 3 was then added thereto and the mixture was subsequently processed further as described in Example 1.
EXAMPLE 4
2.00 g of ®Vulcan XC 72R (manufacturer: Cabot B. V., Rozenburg, The Netherlands), 20 ml of water and 5 ml of methanol were placed in a 100 ml round-bottomed flask containing 5 porcelain spheres (diameter: 10 mm) and were mixed for 4 hours by rotation at 100 rpm on a rotary evaporator. While continuing the rotation, 8.0 g (about 0.4 g of platinum; stabilizer: poly[N,N-di-methyl-N-methacryloxyethyl-N-(3-sulfopropyl)ammonium betaine) sol concentrate which had been prepared as described in Example 1 and had been diluted with 5 ml of water was pumped into the resulting uniform suspension at 20-25° C. over the course of 0.5 hours. The suspension was subsequently rotated for another 3 hours. The coated carbon was centrifuged and dried over concentrated sulfuric acid in a vacuum desiccator. The yield was 2.47 g. Analysis of the catalyst obtained indicated 11% of platinum (ICP-OES). TEM analysis of the catalyst (transmission electron microscope: Philips CM 30; the particles were applied to a carbon-coated copper grid) indicated a fine coating of platinum particles whose diameter was not more than about 1 nanometer.
EXAMPLE 5
An immobilization was carried out by a method analogous to Example 4. The support material used was 2.00 g of ®Vulcan XC 72R (manufacturer: Cabot B. V. Rozenburg, The Netherlands) which had previously been treated with a solution of sulfonated polyether ether ketone (PEEK), molecular weight M n about 80,000, degree of sulfonation 50.7%). 6.6 g (about 0.3 g of platinum, stabilizer: poly[N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl)ammonium betaine]) sol concentrate which had been prepared as described in Example 1 were used.
The yield was 1.9 g.
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Polybetaine-stabilized nanosize platinum particles, a process for preparing them and their use for electrocatalysts in fuel cells
Soluble nanosize particles which have a diameter of from 0.5 to 3 nm, preferably from 1 to 2 nm, comprise platinum alone or platinum and other metals of the platinum group and are embedded in a protective colloid which comprises polymeric betaines and can be degraded by hydrolysis. The betaine is preferably a carbobetaine of the formula —N + R 1 R 2 —(—CH 2 —) n —CO 2 − , a phosphobetaine of the formula —N + R 1 R 2 —(—CH 2 —) n —PO 3 — or, preferably, a sulfobetaine of the formula —N + R 1 R 2 —(—CH 2 —) n —SO 3 —, where R 1 and R 2 may, independently of one another, be identical or different and are alkyl radicals having from 1 to 6 carbon atoms and n is 1, 2 or 3. Also described are a process for preparing the nanosize particles and catalysts produced therefrom and also their use for fuel cells.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the detection of gaseous impurities in an ambient atmosphere such as air by the use of a pulsed corona discharge.
2. Description of the Prior Art
The effects of impurities on the electrical characteristics of gaseous discharges have been recognized for some time, and various discharge phenomena have been employed in the detection of impurities. For the most part, the electrical phenomena involved in different detection methods are not well enough understood so that one such phenomenon can be predicted from knowledge of others. There is no satisfactory unifying theory capable of describing gaseous discharges in all regions and under all conditions, and hence little basis exists for predicting the results of a given test or experiment.
Known detectors whose operation involves electrical discharge phenomena include that of Seitz (U.S. Pat. No. 2,640,870), a detector principally for traces of nitrogen in argon by a constant, high intensity, high current arc in which variations in power dissipation are measured to ascertain the impurity concentration. U.S. Pat. Nos. 1,070,556 to Strong and 2,932,966 to Grindell relate to apparatus for detecting smoke. The former uses an a.c. driven spark discharge arrangement, where sparking between the electrodes occurs in the presence of smoke; the latter employs an electrostatic precipitator modified to include a collector electrode for collecting the charged smoke particles so that a net ion flow proportional to impurity concentration may be measured. U.S. Pat. No. 2,550,498 to Rice describes a detector based on ion formation caused by heating of impurities by a hot platinum element, using an alternating or unidirectional voltage source. Also relevant is an article by Pitkethyl (Analytical Chemistry, August 1958, Vol. 30, No. 8, pp. 1309-1314) which describes a method of gas chromatography employing d.c. discharge detectors. A d.c.-powered leak detection system employing a hot ion source is disclosed in U.S. Pat. No. 3,009,074. A method of detecting rare gases is disclosed in U.S. Pat. No. 2,654,051 to Kenty, in which a d.c. discharge is employed and voltage fluctuations measured.
Other known patents include Lovelock, U.S. Pat. No. 3,046,396, (a d.c. discharge is employed in the detection of helium) and Stokes, U.S. Pat. No. 2,933,676 (a d.c. discharge is used in a manometer). Also see U.S. Pat. Nos. 268,908; 1,231,045; 1,421,720; 1,990,706; 2,783,647; 2,996,661; 3,022,498; 3,065,411; 3,071,722; 3,076,139; 3,144,600; 3,277,364 and 3,339,136. Also, see British Pat. No. 826,195 and the following articles: "Effect of CC1 4 Vapor on the Dielectric Strength of Air," Rodine and Herb, Physical Review, Mar. 15, 1937, pp. 508 et seq; "Magnetic-Electric Transducer," K. S. Lion, Review of Scientific Instruments, Vol. 27, No. 4, Apr. 1956, pp. 222 et seq; "A Radio Frequency Detector for Gas Chromatography," Karmen and Bowman, Gas Chromatography, Second International Symposium Held Under the Auspices of the Instrument Society of America, June 1959, pp. 65-73, (Academic Press, New York and London, 1961).
The above mentioned detectors are not, by and large, satisfactorily capable of detecting halogen gases in low concentrations, or of indicating quantitatively the concentration of a known impurity at low or high levels with any degree of accuracy. Detection of halogens in low concentration is particularly important in inspecting for leaks from refrigeration systems employing Freon and similar halogen-containing refrigerants. Halogen detection is also accomplished according to the teachings in U.S. Pat. Nos. 3,460,125 and 3,559,049 issued to the present applicants. Detection is carried out in accordance with both patents based on changes in the spark breakdown potential of the test atmosphere in the presence of impurities, in distinct contrast to the method described herein which utilizes effects occurring within the continuous corona discharge region and does not involve spark breakdown.
SUMMARY OF THE INVENTION
In accordance with the invention, gaseous impurities are detected by providing a pulsed corona discharge in the continuous corona region, between a pair of electrodes disposed in the atmosphere under test, and measuring the d.c. signal component of the electrode pair. This d.c. signal obtained in accordance with the invention is a highly sensitive indicator of the presence and concentration of gaseous impurities including substances which behave like gaseous impurities such as air-borne liquids and solids.
Inasmuch as some confusion exists as to the various characteristic regions encountered as the voltage across an electrode pair is varied, reference is made for definitional purposes to an article by Weissler and Mohr entitled "Negative Corona in Freon-Air Mixtures," Physical Review, Aug. 15, 1947, Vol. 72, No. 4:
"The characteristic curves of any point-to-plane corona, plotting the gap current against the applied potential, are made up of three ranges of specific interest. The `dark-current` range occurs well below the onset of any visible corona, and the sharper the point the narrower this range will be. It depends most strongly on the first Townsend coefficient α and to a lesser degree on the secondary mechanism near the point. The latter is caused chiefly by the efficiency of liberation of electrons from the point surface by positive ion bombardment and also to some photoelectric liberation from the cathode. The currents in this range vary from 10 -14 ampere to about 10 -8 ampere. Photo-ionization and excitation in the gas as well as space-charge distortion of the static electric fields are negligible.
"In the `intermittent-corona` range the currents vary from 10 -8 to about 10 -6 ampere, and the corona becomes visible. In addition to the coefficient α, the secondary actions at the cathode point become more prominent. The most characteristic aspect of this range is the flickering or intermittent, visible corona. Associated with it are large current fluctuations at any fixed potential and transient space-charge pulses in the immediate vicinity of the point. Space-charge distortion of the electric field occurs intermittently. The corona is not self-sustaining and requires electrons from external ionizing sources to re-initiate it.
"The third range is that of the `continuous corona` where the currents for a given potential are steady and reproducible and where the visible character is not erratic. The corona is self-sustaining, and the currents vary smoothly from about 10 -5 ampere until this form of discharge is finally terminated by a disruptive spark or arc."
The method disclosed herein employs the continuous corona region of the discharge. While detection is feasible with positive corona, sensitivity is much higher employing negative corona; hence the latter is preferred.
Weissler and Mohr, describing the effect of halogens on a discharge produced by constant electrode voltage, found that:
"With mixtures of from 0.1 to one percent of .[.freon.]. .Iadd.Freon .Iaddend.in dry air the only notable difference occurred with the appearance in the intermittent corona region of what might be termed a hysteresis effect."
In other words, no effects were noted in the continuous corona region, and only a large time scale (of the order of minutes) hysteresis effect was found in the intermittent corona region.
It is all the more surprising, therefore, that voltage pulses in the continuous corona region provide a discharge which is extremely sensitive to Freon concentrations as low as one part per million (ppm).
Equally surprising is the accuracy of the method of the invention in measuring impurity concentration at low levels, as opposed to simply detecting impurities; the d.c. electrode current is an accurate indicator of such concentration.
In a negative corona detector in accordance with the invention, concentrations as low as 1 ppm Freon 12 (CC1 2 F 2 ) may be detected. Even lower concentrations of other Freons are detectable. In general, electropositive gases such as carbon monoxide, methane, propane, and the like increase the d.c. corona current, whereas electronegative gases such as Freon 12 decrease it. Sensitivity to electropositive gases is adequate for detection of 1,000 ppm on the average. The invention is well suited for the precise measurement of carbon monoxide in internal combustion engine exhaust gas, where it is present in concentrations of about 1 to 10 percent. Carbon monoxide as so measured is a good indication of combustion efficiency.
For optimal sensitivity, an asymmetrical electrode pair is employed in accordance with the invention. Preferably, a sharply pointed electrode opposite a hemispherical plane electrode is used, free of impurities.
The continuous corona region is essentially current-defined, so that impedance of a specific electrode pair determines the voltage range appropriate for detection in accordance with the invention. For an electrode impedance of 50 megohms, for example, a voltage range of about 1,800 to 2,700 volts may be employed, giving a peak current of about 40 microamperes. Electrode impedance is defined as the ratio of peak pulse voltage to peak discharge current under the operating conditions (i.e. pulse repetition rate) employed for detection.
The particular physical properties of the discharge determinitive of minimum and maximum pulse separation are not fully understood at this time. Sixty-cycle alternating current permits detection in accordance with the invention, yet sensitivity is only one-tenth as great as when the discharge is produced by sub-millisecond pulses about 10 milliseconds apart.
DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will be described in connection with the accompanying drawings, in which:
FIG. 1 is a block circuit diagram of a detector in accordance with the invention;
FIG. 2 is a graph of the mean corona current versus electrode voltage for d.c. and pulse electrode voltages;
FIG. 3 is a graph of mean corona current versus Freon 12 concentration in parts per million;
FIG. 4 is a schematic circuit diagram of a preferred embodiment of the invention; and
FIG. 5 is a schematic circuit diagram of an alternative embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
As shown in FIG. 1, a pulse source 10 is connected to supply negative-going pulses to the pointed one 11 of a pair of electrodes, the other of which 12 is preferably a small, hemispherical surface disposed as indicated about point electrode 11. The hemispherical electrode is grounded.
The pointed electrode 11 may be formed of fine wire, i.e. one to three mils in diameter preferably formed of a highly refractory metal such as tungsten. The interior of the hemispherical electrode 12 should be free of all projections and edges which might otherwise cause sparking. The interior radius of hemispherical electrode 12 is 3/32 inch, and it may be provided with holes or slits to admit the atmosphere under test into the corona region.
Voltage source 10 should be capable in this embodiment of supplying negative voltage pulses between about 1,800 and 2,700 volts peak. Preferably, the pulse width may range from a few microseconds up to about 300 microseconds, with a pulse repetition rate of the order of 100 p.p.s. The pulse length and separation are not critical, and no sharp changes in detection characteristics will result if they are varied somewhat. The pulse rate must be fast enough to obtain adequate sampling in the particular application intended (i.e. usually at least 10 p.p.s.) and should be slow enough to avoid a duty cycle greater than about 10 percent. The duty cycle is preferably of the order of 1 percent.
An ammeter 13 capable of measuring average current is provided in series with the voltage source and the electrode pair for measuring the average current, or d.c. current component, of the electrode pair. This d.c. current is in accordance with the invention a sensitive measure of impurity concentration. The ammeter should be capable of indicating in the microampere range.
FIG. 2 illustrates the detection capability of the device of FIG. 1 in comparison with that of a similar device employing a d.c. electrode voltage supply. The vertical scale is plotted in terms of numbers simply to illustrate the relative changes in mean corona current under d.c. and pulsed voltage drives. For this purpose, the tests illustrated by FIG. 2 were carried out in dry air using Freon 12 as the impurity. In the absence of impurity (the zero ppm curve), the mean corona current as a function of voltage was plotted for both the pulse and d.c. conditions. Although the actual mean corona current is obviously different for the pulsed and d.c. drive condition, the two curves were plotted as one by introducing a scale factor for purposes of comparison. The same scale factor was used in plotting the curves for the pulsed and d.c. drive conditions at 100 ppm impurity concentration, so that these curves accurately indicate the comparative detection capability of .[.the invention and, say, a device such as that disclosed by Weissler and Mohr, supra.]. .Iadd.an embodiment of the invention substantially as shown in FIG. 4 and the same detector including a rectifier and capacitor, across the electrodes.Iaddend.. The two curves plotted for 100 ppm impurity concentration clearly demonstrate the much greater detection capability of the method of the invention employing a pulsed electrode voltage.
The precise explanation for this significantly improved result is not fully understood; however, it may result from the presence of heavy ions such as C1 - and F - . These ions form a space charge region about the negative electrode. In a d.c. field, the space charge first tends to diminish the discharge current; then the ion cloud moves away from the negative electrode, again permitting current flow. Under pulsed excitation, however, lack of sufficient time for movement of the ion cloud from the negative electrode may enhance the effect of these heavy ions, permitting detection and measurement at lower impurity levels than were previously feasible.
From the point of view of the electrode voltage and current alone, it is theoretically not necessary to measure the mean corona current to obtain detection in accordance with the invention; peak corona could be measured under the pulse drive conditions described herein and would theoretically provide .[.as.]. .Iadd.an .Iaddend.equally sensitive detection. However, when employing an a.c. (e.g. pulsed) electrode drive, stray capacitance contributes spurious currents to the measured value. It is therefore necessary to measure corona current in a manner which will exclude these spurious contributions and include only the true corona current. This is done in accordance with the invention by measuring the mean corona current, since the corona current is intrinsically rectified, cancelling out the effects of stray currents.
FIG. 3 is a graph (with the horizontal scale plotted logarithmically) of mean corona current measured by the device of FIG. 1 versus Freon 12 concentration in parts per million (by volume).
FIG. 4 is a schematic diagram of a preferred embodiment of the invention wherein an audible output signal is provided which produces a series of clicks. As in a Geiger counter, the frequency of the clicks increases dramatically proportionally to the increased concentration sensed by the instrument, providing an extremely efficient method for locating a leak, for example, from a refrigeration system.
The voltage source in FIG. 4 is provided by a blocking oscillator 20 including an output transformer 21, the output winding of 22 of which is connected to supply negative-going pulses to the pointed electrode of electrode pair 23. The blocking oscillator includes a transistor 24, the collector-to-emitter output of which is applied to input winding 25 of the transformer. Variable limiting resistor 26 is connected in series with the feedback winding 27 of the blocking oscillator in order to control the maximum electrode voltage at a value below spark breakdown. This is to prevent spark breakdown from occurring at the highest impurity concentrations expected to be encountered as well as in an impurity-free atmosphere. As the battery deteriorates, resistor 26 is varied to maintain substantially constant amplitude pulses at the electrodes, manifested (for example) by a constant clicking rate in the absence of impurities.
For measuring mean corona current, an R-C circuit formed of resistors 28 and 29 in parallel with a capacitor 30 is connected between output winding 22 and ground. The two-pole, two-position switch 31 is employed to switch the sensitivity of the device of a high sensitivity range in which the full output of the R-C circuit is supplied to the audio circuit, or a low-sensitivity range wherein only a portion of the output voltage is supplied to the audio circuitry. When switch 31 is connected in the low sensitivity position, the output voltage is tapped off between resistors 28 and 29. An additional capacitor 33 is provided as a high frequency shunt in the low sensitivity position.
The output voltage from the R-C circuit is fed to the gate of a FET 34, so that the positive gate voltage in the absence of impurities is sufficient to nearly produce pinch-off. The source-drain circuit of FET 34 is connected in the feedback loop of a two-transistor multivibrator 35 to provide control of the oscillatory frequency of the multivibrator. The output of the mutlivibrator is fed through a speaker 36 which produces a series of clicks, preferably sounding like a Geiger counter, described above.
When FET 34 is near pinch-off, the oscillatory frequency of multivibrator 35 is low. With increasing concentrations of impurity, as shown in FIG. 3, the mean corona current and hence the output voltage from the R-C circuit applied to the gate of FET 34 drops, causing the frequency of oscillator 35 to rise. Hence, the clicking rate, or at higher frequencies the pitch, of the audio signal produced by speaker 36 clearly and dramatically indicates the existence and severity of a leak. A capacitor 37 may be provided between the source terminal of FET 34 and ground to improve the tonal quality of the audio output signal. In the low sensitivity position of switch 31, there may not be sufficient voltage applied to the gate of FET 34 to nearly obtain pinch off. In order to produce a sufficiently low frequency audio output signal, therefore, an auxiliary bias supply 32 is provided which takes advantage of the high voltage pulses appearing on feedback winding 27 of the blocking oscillator. Bias supply 32 includes a diode 38 in series with a parallel R-C circuit formed by capacitor 39 and resistor 40, the variable tap of which constitutes one terminal of sensitivity switch 31, thereby providing additional d.c. bias current in the low sensitivity position to the gate terminal of the FET.
In the embodiment shown, the value of variable limiting resistor 26 is about 1,000 ohms, while in the high sensitivity position of switch 31, resistor 28, 29 and capacitor 39 have values of 13 megohms and 0.01 microfarads, respectively. The time constant of the R-C circuit should be several times longer than the period between pulses.
FIG. 5 illustrates an embodiment of the invention similar to that of FIG. 4 but with a visual rather than an audible output, permitting more accurate measurement of impurity concentration. The unnumbered elements in FIG. 5 may be identical to those described in connection with FIG. 4. FET 34 is connected as one arm of a Wheatstone bridge circuit 45, the other arms being formed by resistor 41 and the two sides, divided by the variable tap, of potentiometer 42. In operation, potentiometer 42 is adjusted to give zero output reading on voltmeter 43, which may be calibrated directly in terms of impurity concentration. The inertial time constant of voltmeter 43 should be several times longer than the time between successive pulses in the absence of impurities, to provide a constant indication for constant impurity concentration.
It will be appreciated by those skilled in the art that various changes and modifications may be made to the above described preferred embodiments without departing from the scope and spirit of the invention as defined by the claims herein.
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A method .[.is disclosed.]. of detecting gaseous impurities, particularly halogens, in an ambient atmosphere by repeatedly pulsing a pair of electrodes disposed in that atmosphere with a voltage sufficient to cause a corona discharge in the continuous corona region, and detecting the average (d.c.) current component of such discharge, changes in which correspond to changes in the concentration of such gaseous impurities. Apparatus .[.is disclosed.]. for detecting such impurities in concentrations as low as 1 ppm.
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FIELD OF THE INVENTION
[0001] The present invention relates to a device and process for shaping and welding, simultaneously performed, pipe connectors (also known as dowels) primarily intended for use in compressors. More specifically the process presented here concerns the simultaneous shaping and welding of copper pipes—used as connectors for suction, process and discharge—to the hermetic compressors metal housing for refrigeration, with the aim of reducing steps of the production process, making it more efficient and economical.
BACKGROUND OF THE INVENTION
[0002] As is known in the art, the hermetic compressors are devices widely used in refrigeration systems in general, the components being responsible for providing the circulation of the refrigerant fluid through the tubing of the cooling systems. The suction and discharge connector pipes have the function of conducting the refrigerant gas through the compressor housing, connecting the inside thereof to the pipes of the refrigeration system. The connector tube of process has the function to be the pathway of oil and/or refrigerant fluid injection during installation of the compressor in the refrigeration system. It should be clarified that such connector pipes are typically made of copper due to the ease of connection by brazing with the pipes of the system.
[0003] It happens, however, that the proper operation of such equipment also depends on the perfect sealing conditions between these connector pipes and the compressor metal housing, being such connector pipes produced in copper and the compressor housing generally manufactured in steel, such welding process becomes significantly complicated.
[0004] The most known form of assembly provides the use of brazing additional materials which are arranged between the hole of the compressor housing and the connector tube as disclosed, for example, in document JP2010038087. Although this document involves the use of a connector pipe without needing prior conformation, such process presents however the disadvantage of needing the use of addition material for welding.
[0005] An alternative technique is presented in document CN101780602 (see FIGS. 2 and 3 attached) which provides the use of upper 200 and lower 201 electrodes disposed in order to involve the entire outer surface of connector pipes 110 , these electrodes being responsible for the passage of a electrical current from 30,000 to 50,000 Amperes for about 30 to 80 milliseconds to heat the copper and make it pliable to, by applying a compressive force, weld the flange copper of the connector tube 110 on the surface of the housing 2 with which it is in contact. It happens, however, that such process requires the existence of a flange ( 111 ) in the body of the copper dowel—that is, the need of further steps in the process, making it more complex and more expensive compared to the solution proposed herein.
[0006] Another example of installation of connector pipe in hermetic compressors was disclosed in document PI0603392-0, in which connector pipes 110 previously conformed and also necessarily provided with flanges 111 —which constitute the coupling means of the piece—are welded directly to housing 2 of compressor C by means of the application of electrical current through electrodes 200 / 201 . The drawbacks of this process relate to the fact that it is required a prior conformation of flange 111 before the welding operation, requiring a complex operation additional to the production process, and it is more expensive when compared to the solution proposed herein.
[0007] Note that all processes of the current state of the art demand the introduction of the ends of connector pipe 110 inside the suction and discharge holes of compressor C. Therefore, it is noted that the current state of the art lacks a welding process which, besides being more efficient, simple and economical, also allows the welding between the parts is of the “top” type, thus eliminating the need of previous shaping of the copper pipes to the production of flanges for welding and eliminating the need to use addition material for brazing. The current technique also lacks a process that allows the shaping and welding of connector pipes to compressor casings to be made in a single step and, therefore, significantly more rapid and economical.
[0008] Objectives of the Invention
[0009] Therefore, it is one objective of this invention to provide a process which simultaneously performs shaping of flange and welding of connector pipes, such connector pipes being copper pipes lacking flange and which, therefore, require no previous shaping prior to its connection (welding) to the compressor housing.
[0010] It is also an object of this invention to provide a process for top welding between copper connector pipes and the housing, usually steel, of the compressors.
[0011] Another among the objectives of the present invention is to provide a process that simultaneously performs shaping of a flange and welding of connector pipes, which preferably uses a servomotor as element for the generation of force and displacement of the connector pipes against the compressor housing.
[0012] It is yet another among the objectives of this invention to provide a process using a stopper for applying compressive force to the connector pipe.
[0013] Another objective of the invention is to provide a process in which the welding between the connector tube and the compressor housing is made by applying a force comprised within the range of 200 to 500 kgf in place of the force of about 1100 kgf employed for the welding made by known techniques.
[0014] Furthermore, it is an objective of the invention to describe a welding process which uses a guide pin that, besides providing alignment between the connector pipe and the housing hole, it also prevents constriction of the through hole of gas and the connector pipe, during simultaneous shaping and welding steps, also preventing the housing deformation caused by the force of welding, because it is executed with lower electrode of diameter larger than that of the connector pipe.
SUMMARY OF THE INVENTION
[0015] The above objectives are achieved by means of a simultaneous shaping and welding device of connector pipes for compressors, such connector pipes being defined by substantially cylindrical bodies which engage to gas through holes existing in the housing of the compressors which constitute its suction and discharge channels.
[0016] In one of the main embodiments of the present invention, said device comprises:
a upper electrode-holder cooperating with one of the poles of an inverter set and with transformers; a upper electrode cooperating with the upper electrode-holder and with the upper region of the connector pipe; a welding force application stop cooperating with the upper electrode-holder and with the upper end of the connector pipe; a lower electrode-holder cooperating with the other pole of an inverter set and with transformers; an electrical insulation means cooperating with the inner surface of the lower electrode-holder; a lower electrode holder cooperating with the lower electrode-holder and with the compressor housing, being the inner diameter of the bottom electrode equal to or greater than the outer diameter of the upper electrode, and A centralizing pin coupled to the internal region of the electrical insulation means and cooperating with the gas through hole of the compressor housing and with the connector pipe.
[0024] Also according to one of the preferred embodiments of the invention, the lower electrode-holder, the electrical isolation means, the lower electrode and the centralizing pin comprise the lower components of the shaping and welding device.
[0025] In addition to the upper electrode-holder, the upper electrode and the welding force application stop comprise the upper components of the shaping and welding device.
[0026] In short, the device constructed according to a preferred embodiment of the invention comprises means for allowing the top welding between the connector pipe and the compressor housing.
[0027] Preferably the inner diameter of the connector pipe is equal to the diameter of the gas through hole of the compressor housing.
[0028] Also in a preferred form, the welding force application stop of the instant device functions with intensity comprised within the range of 200 to 500 kgf, more specifically in the range of 330 to 400 kgf.
[0029] Preferably the upper device allows the application of current pulses without occurring simultaneous displacement.
[0030] The objectives of the invention are also achieved by means of a shaping and welding process of connector pipes for compressors which comprises the use of a shaping and welding device of connector pipes for compressor in order to perform the following steps:
positioning the upper components of the shaping and welding device by means of coupling of the upper electrode around the connector pipe, until the stop for force application located inside the upper electrode-holder reaches the top edge of the connector pipe; driving the displacement mechanism, preferably a servomotor to provide the approximation of the connector pipe to the surface of the compressor housing using as positional parameter the end of the centralizing pin which passed through the gas through hole of the compressor housing; activating the compression and welding force, and its maintenance during an stabilization time; applying the first pulse of electrical current with intensity ranging between 30 and 50 kA, without allowing displacement of the upper device; suspending the application of current and allowing the displacement of the upper device with a consequent increase in the welding force to form the flange; applying the second current pulse effectively consisting in the welding time of the piece; suspending the current application with maintenance of the force application to provide better welding condition; shifting the upper electrode to the rest position.
[0039] It should be noted that this shaping and welding process comprises, in short, means for shaping and welding, simultaneous and in loco, flange to weld the connector pipe to the compressor housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The present invention will be hereinafter further described based on the drawings.
[0041] The figures show:
[0042] FIG. 1 —a view in elevation of a compressor provided with connector pipes for connection to the pipes of a general cooling system;
[0043] FIG. 2 —a longitudinal sectional view of a connector pipe used in the current state of the art;
[0044] FIG. 3 —a schematic sectional view of the components used in the current state of the art to effect the welding between the copper connector pipes and the compressor;
[0045] FIG. 4 —in longitudinal section view of a copper pipe which can be used for shaping the connector pipe by the process of the present invention;
[0046] FIG. 5 —a schematic sectional view of the components used in the shaping and welding process of connector pipes of the present invention;
[0047] FIG. 6 —a variables diagram of the welding process employed in the present state of the art;
[0048] FIG. 7 —a variables diagram of the shaping and welding process of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0049] The invention will now be described in detail based on the accompanying drawings, to which are given number reference to facilitate the understanding.
[0050] The simultaneous shaping and welding process object of the present invention aims the proper fixation of copper connector pipes 1 to the housing of the hermetic compressors 2 , such connector pipes 1 ( FIG. 4 ) defined by substantially cylindrical bodies and of uniform and rectilinear outer surfaces 11 —unlike the connector pipes 110 of the current state of the art ( FIG. 2 ), which necessarily must be previously shaped to be fitted with flanges 111 to act like welding surface to the housing 2 .
[0051] As can be seen in details by FIG. 5 attached, the shaping device of the present invention is comprised, superiorly by an upper electrode-holder 3 which acts connected to one of the poles of the inverter set and transformers, which maintains coupled, in its end, an upper electrode 4 of substantially cylindrical conformation to be coupled to the upper region of the connector pipe 1 . The lower component of the shaping device comprises a lower electrode-holder 5 connected to the other pole of the inverter set and transformers, such lower electrode-holder accommodates an electrical isolation means 6 , the centralizing pin 7 and a lower electrode 8 whose inner diameter is equal to or greater than the outer diameter of the upper electrode 4 , in order to prevent that the electrical current supplied by electrodes 4 and 9 is applied to the inner and outer point of housing 2 , which could cause premature wear of the centralizing pin.
[0052] For comparative purpose, it should be clarified that as can be seen from FIG. 3 attached, in the welding process used in the current state of the art, lower 201 and upper 200 electrodes are overlapped during welding, resulting in a too high heating that, sometimes, eventually also affect the structure of the compressor housing itself, besides reducing the lifetime of centralizing pin 203 , as explained above.
[0053] Furthermore, the current technique demands two separate steps for installing the connector pipes to the compressors housings: a previous step of shaping the same to make flange, and another one for welding the pipes already flanged to the compressor housing. In the proposed invention, the two procedures are simultaneously performed in a single step of the process, making it faster and more economical.
[0054] As can be seen in FIG. 5 , with the device and procedure presented here, the welding is made of top, so that it is possible to use connector pipes 1 with inner diameter equivalent to the diameter of the gas through hole to which the same will be connected. With such a configuration, the welding surface of connector pipe 1 becomes, therefore, its lower edge, eliminating the need of existence of flange which requires prior shaping of the copper pipe. In the present technique, besides being necessary the existence of flange previously shaped on the connector pipe, its end must have a diameter that allows its coupling to the male type hole of the compressor housing (see FIG. 3 ).
[0055] In addition to this facility, it must be noted that the use of centralizing pin 7 prevents the copper, once made ductile by the passage of electrical current from the electrodes 4 and 9 , to find passage to deform the inner region of the housing hole 2 , that is, it does not obstruct the passage of gas and thus does not interfere with the performance of the compressor.
[0056] Another important point herein refers to the compressive force used to implement the process. In the welding processes of the present technique, it is required a compressive force of about 1100 kgf intensity. During the application of this intensity of force, it is made the application of a single current pulse of 30 to 50 kA. The diagram illustrated n FIG. 6 shows graphically the variables current, force and displacement of the upper electrode of the known processes.
[0057] In the process of the present invention, due to the construction of the welding device and preferential use of a servomotor, the compressive force necessary for the welding of connector pipe 1 preferably comprises 200 to 500 kgf—that is, much lower than the one demanded by the known processes. Furthermore, in the proposed process, the welding is performed in two steps, namely, by applying two pulses of current: the first pulse for heating the copper, making it more pliable, facilitating the shaping step of the flange, and the second pulse to the effective welding. The Diagram in FIG. 7 schematically illustrates the variables used in the process, besides illustrating the effects of each step of the process.
[0058] Thus, the steps of the shaping and welding process of connector pipes for compressors object of the present invention are:
positioning the inner region of housing 2 of compressor C on the lower components of the shaping and welding device, so that centralizing pin 7 is fitted into the fluid through hole; positioning connector pipe 1 within upper electrode 4 , until the stop for force application 10 located inside upper electrode-holder 3 reaches the top edge of connector pipe 1 ; driving servomotor to provide approximation of connector pipe 1 to the surface of the compressor housing 2 , using as positional parameter the end of centralizing pin 7 that passed through the gas through hole of compressor housing C; activating the compression and welding force, and maintenance of said force for a stabilization time; applying the first pulse of electrical current with an intensity ranging between 30 and 50 kA, without allowing displacement of the upper device, that step may be termed pre-heating time; suspending the current application and allowance displacement of the upper device with consequent elevation of the welding force for shaping the flange; applying the second pulse of current that will consist, effectively, of piece welding time; suspending the application current with maintenance of the application of force to provide better welding condition; shifting the upper electrode to the rest position.
[0068] Thus, at the end of the process, the lower end of copper connector pipe 1 which shaped during heating provided by the application of electrical current pulses has settled around the gas through hole of the compressor housing and, due to the force applied by the stop, if acceded to it.
[0069] The process object of the present invention also has the advantage that, by virtue of being shaped in loco, it causes the welding material to be integral to the material/body of the connector pipe, thus minimizing the existence of weak points likely to suffer damages or ruptures that could compromise the efficiency of the equipment.
[0070] It is noteworthy that although preferred constructive ways of the present invention have been shown, it is understood that any omissions, substitutions, inversion of electrical poles and constructive changes can be made by a technician versed in the subject, without departing from the spirit and scope of protection required. It is also expressly stated that all combinations of elements which perform the same function in substantially the same way to achieve the same results are within the scope of the invention. Substitutions of elements of an embodiment described by others are also fully intended and contemplated.
[0071] It should, however, be understood that the description given based on the figures above refers only to some of embodiments feasible to the system of the present invention, while its actual scope is set out in the appended claims.
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The present invention relates to a shaping and welding device and process of connector pipes or dowels ( 1 ) primarily intended for use in 10 compressors. More specifically the process presented here concerns the shaping and welding of copper pipes ( 1 ) used as connectors for suction, discharge and process, the metal housing ( 2 ) of hermetic compressors, with the goal of making this equipment much more practical, efficient and economical.
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FIELD OF THE INVENTION
This invention is directed to a debris-resistant nuclear fuel assembly and, more particularly to such an assembly employing a lower tie plate unit constructed to collect potentially harmful debris carried in the flow of coolant material (e.g. water). The invention is useful either alone or in combination with a debris-resistant grid spacer arrangement of the type described in U.S. Pat. No. 4,849,161, granted to Charles A. Brown et al. on July 18, 1989, which patent is assigned to the same assignee as the present invention, or for incorporation in a debris-resistant lower tie plate assembly described in a concurrently filed U.S. application Ser. No. (07/0518891) of Brown et al., also assigned to the same assignee as the present invention.
BACKGROUND OF THE INVENTION
As is stated in the Brown et al patent, in the operation of nuclear reactors such as pressurized water reactors (PWR's) or in boiling water reactors (BWR'S), it has been found that debris such as nuts, bolts, metal cuttings, wires, and drill bits sometimes accumulate in the reactor during construction, repair or the like. Certain mid-range sizes (1/2" to 4") of this type of debris are particularly troublesome, since that debris is likely to be carried by cooling water to the area near the bottom (lower ends) of the fuel rods. The debris vibrates in the moving coolant and impacts principally upon lower ends of the rods, ultimately abrading and causing fretting wear of the fuel rod cladding at that point. This type of wear is recognized as a significant cause of fuel failures. As is noted in the Brown et al patent, one prior approach to this problem was to use extra long solid lower end caps on the fuel rods. The end caps did not contain fuel and therefore there would be no escape of radiation if extensive fretting wear occurred in the end caps. However, that approach of using elongated end caps reduces the fuel column length and may result in a reduction of power output for a given overall size of the reactor.
In the Brown et al. patent, a lowermost grid spacer is described which is positioned on or only slightly above the lower tie plate. The geometry of the Brown grid spacer is arranged to divide coolant flow openings in the lower tie plate into smaller openings and thereby trap at least part of the debris in the zone near the lower tie plate before the debris comes in contact with the fueled portion of the rods.
As an indication of the significance of the debris problem, reference may be made, for example, to recently issued U.S. Pat. such as Nos. 4,652,425--Ferrari et al , granted Mar. 24, 1987; No. 4,684,495--Wilson et al., granted Aug. 4, 1987; No. 4,684,496--Wilson et al., granted Aug. 4, 1987; No. 4,781,884--Anthony, granted Nov. 1, 1988; No. 4,828,791--De Mario, granted May 9, 1989 and No. 4,832,905--Bryan et al , granted May 23, 1989.
While a number of the foregoing proposals to reduce the debris problem have focused remedial attention on the region in the vicinity of the lower tie plate, certain of the proposals have required that additional space in the vicinity of the tie plate be taken from the length of the active fuel rods in order to insert means to accomplish the desired collection of debris. Other proposed approaches also may result in an unacceptable drop in coolant pressure, thereby adversely affecting the desired heat transfer to the coolant.
The present invention, on the other hand, is directed towards a lower tie plate assembly incorporating an integral, improved debris screen or alternatively, having an added debris screen positioned within the confines of an existing lower tie plate but which is capable of trapping significant additional debris.
STATEMENT OF THE INVENTION
In accordance with one aspect of the present invention, a debris screen for a fuel assembly for a reactor to which coolant fluid is supplied comprises a substantially planar plate member having an array of coolant openings extending through the plate member dimensioned to trap at least a portion of debris particles carried by the coolant and a skirt member enclosing the periphery of the plate member; each of the coolant flow openings having a coolant entry region at a lower surface, a coolant exit region at an upper surface and a coolant flow path extending between the entry and exit regions, the flow path including an intermediate segment laterally offset from the entry and exit regions to cause coolant to change direction of flow in the intermediate segment and thereby prevent at least a portion of the debris particles from passing through the plate members.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is an elevation view, partially in section, of a fuel assembly incorporating one version of the present invention, the assembly being foreshortened in height and partially broken away for convenience and clarity;
FIG. 2 is a partial plan view, drawn to a different scale than FIG. 1, of one version of a lower tie plate arrangement constructed in accordance with the present invention;
FIG. 3 is a sectional view, drawn to the same scale as FIG. 2, along the line A-A' shown in FIG. 2;
FIG. 4 is a partial plan view, of a second version of a debris screen for use in a lower tie plate arrangement constructed according to the present invention;
FIG. 5 is a partial sectional view taken along the line B-B' in FIG. 4;
FIG. 6 is a partial isometric view of the second version of a debris screen constructed according to the present invention;
FIG. 7 is a partial isometric view of a third version of a debris screen constructed according to the present invention; and
FIG. 8 is a front elevation, partially broken away, of a lower tie plate incorporating the debris screen of FIG. 7 as a retrofit assembly.
DETAILED DESCRIPTION
Referring to FIG. 1, a 14×14 fuel bundle assembly is indicated generally by the reference numeral 10. The fuel assembly 10 includes an upper tie plate 12 and a lower tie plate 14 capturing at opposite ends a plurality of (e.g. 176) fuel rods 13. A plurality of guide tubes 11 are secured to upper tie plate 12 and to lower tie plate 14. A plurality of grid spacers 15 (e.g. eight) are disposed along the length of the fuel rods 13 at locations between the tie plates 12, 14 and form cells, as is well known, through which the fuel rods 13 and guide tubes 11 extend. A lowermost one 15' of the grid spacers is illustrated as a debris-resistant spacer of the type shown and described in U.S. Pat. No. 4,849,161 of Brown et al. The description of that debris-resistant spacer 15' contained in the Brown et al. patent is herein incorporated by reference.
Each of the fuel rods 13 includes a stack of fuel pellets 16. The pellets 16 in each stack are maintained in close proximity to each other by means of a spring 17 disposed between an upper end of the rod 13 and the uppermost one of the pellets 16. The lower end cap 18 of each fuel rod is in close proximity to but spaced away from the upper portion of lower tie plate 14 to take into account the expected linear growth of the rods 13 in the normal operation of the reactor. The total height from the bottom of lower tie plate 14 to the top of the uppermost pellet 16 (i.e. the top of the active fuel) may, for example, be a few inches less than twelve feet.
Referring now to FIGS. 2 and 3, one version of a lower tie plate assembly 14 constructed in accordance with the present invention is shown. Lower tie plate 14 comprises a multi-apertured, upper planar member or plate 20, a partial plan view of which is shown in FIG. 2. Planar member 20 contains a number of elongated openings or holes 24 adapted for flow of coolant out of the assembly in a vertical direction from one or more inlets below tie plate 14 as indicated by the vertical arrow in FIG. 3.
A downwardly extending skirt 16 is fastened around the periphery of upper planar member 20. Skirt 16 may extend substantially to a lower core support plate 40 as indicated in FIG. 1 or, alternatively, front and rear portions of skirt 16 may be foreshortened except for the lower most extensions thereof which are provided at the corners 18 of tie plate 14 (see e.g. FIG. 8).
An array of regularly spaced, substantially parallel, curved or bowed blades or plates 22 are connected between two sides (e.g. front and back) of the skirt 16 and extend downwardly between upper plate 20 and an array of parallel lower cross tie members or bars 19. The skirt 16 typically may be provided with a shoulder 21 for supporting the ends of lower cross tie bars 19. Suitable support blocks 23 for guide tubes 11 and apertures 30 for receiving guide tube screws (not shown) are provided at appropriate locations within lower tie plate 14.
The curved plates 22 may be bowed as shown or may be of "hairpin" shape. It should be noted that the two curved blades 22 which are adjacent each other at a midpoint of the assembly (see third blade from broken away right hand end in FIG. 3) are disposed in reverse directions to provide symmetry. In any case, it is intended that the curve or bend of curved plates 22 be such that there is no straight, unobstructed path through the openings or spaces 25 between adjacent pairs of curved plates 22. The curved plates 22 comprise an upper end portion 22a, a lower end portion 22b and an intermediate laterally offset segment 22c. The direction of coolant flow in at least the offset segment 22c is changed, for example by 90°.
The curved plates 22 are fastened to the lower cross tie bars 19, for example, by brazed connections. Similarly, curved plates 22 are fastened to upper plate 20 (or to upper cross tie members--not shown) by brazed connections.
Coolant supplied from below the lower tie plate 14 typically carries debris of the type noted above. As the coolant (water) flows upwardly through the offset or non-lineal spaces 25 between adjacent pairs of curved plates 22, debris of a dimension greater than the width of spaces 25 (e.g. of the order of less than one-tenth inch) may be expected to be intercepted by the effective screen provided by the array of curved plates 22. Where an upper plate 20 having limiting apertures 24 also is provided, an additional portion of the debris which may pass through the spaces 25 also will be intercepted by the non-apertured portion of upper plate 20. In any case, the debris, which typically is relatively heavy metallic material, will tend to drop down below the plates 22.
A bowed, hairpin or other similar shape of blades 22 is effective to prevent passage of relatively long, narrow pieces of debris such as wire from passing through spaces 25 and thereafter passing through upper plate 24. Such long wire debris would, to a greater extent, pass through a screen including simple, unobstructed vertical slots or channels as has been proposed in some prior screens. The offset in the intermediate portion 22c of the blades 22 is effective to turn a piece of wire from a vertical direction to a non-vertical direction of movement as that material passes from the lower section 22b to the intermediate portion 22c. The hairpin or curved space 25 is effective to prevent the long type of debris from streaming on through the space 25. While the foregoing arrangement may be expected to result in some increase in pressure drop (e.g. of the order of twenty-five percent) as compared to straight holes through a plate of similar thickness, the beneficial effect of filtering out debris is considered to outweigh the disadvantage of such a pressure drop in the coolant.
Referring now to FIGS. 4-6 of the drawing (which are not all drawn to the same scale), a second embodiment of the invention is shown in which bowed blades 22 (e.g. three-quarter inch high), interconnecting upper cross tie members 29 (e.g. one-half inch high by one-eighth inch wide) and an overall integral screen structure are formed, for example as a unitary casting (see FIG. 4). A substantial number of the curved or bowed blades 22 have a recess 30 (e.g. 1/8" deep) at their upper extreme. The uppermost surfaces of cross tie members 29 and non-recessed blades 22 are spaced apart by an appropriate distance to support rods (not shown) which may contact those surfaces. As can be seen in the cross-sectional view of FIG. 5, a skirt 16 also may be cast integrally with the blades 22 and cross tie members 29. As a result of the rigidity of the cast structure, no lower cross tie members are required in this embodiment. It should be noted, however, that a greater pressure drop (up to 50%) may be encountered utilizing a casting since the roughness of the walls of the blades 22 will be increased and the flow even will be reduced as compared to that, for example, of sheet or strip metal which may be employed in the arrangement of FIG. 2. The casting may however, be made smooth by conventioned methods. However, like the embodiment of FIG. 2, the blades 22 of FIG. 6 are shaped so that there is no direct, line-of-sight, open passage through the spaces 25.
Referring now to FIGS. 7 and 8, a third embodiment of the invention is shown. In the front elevation shown in FIG. 8, an arrangement is shown employing a screen assembly similar to that of FIG. 2 but which is added below an upper plate 20 of a standard lower tie plate 14. That is, in FIG. 8, an arrangement is shown in which a debris screen including an array of curved blades is retrofit into an existing lower tie plate 14. In that case, appropriate openings or cutouts may be required in the overall shape of the debris screen to accommodate existing guide tube screws (not shown) and locating pins (not shown) on a lower core support plate 40 associated with lower tie plate 14. One such configuration is shown in FIG. 7.
In FIG. 7, both upper tie bars 29' and lower tie bars 19' are shown, the latter being of smaller diameter (e.g. 1/8") as compared to the former (e.g. 3/16"). However, only three pairs of such bars 19', 29' are shown for purposes of illustration. In an actual arrangement, for example, fourteen pairs of bars 19', 29' are utilized. The bars are spaced so as to intercept any rods which might drop down in the fuel assembly. Furthermore, while the lower tie bars 19' are illustrated as being flush with the lower edge of skirt 16, the upper tie bars 29' are illustrated as projecting above the top edge of skirt 16 to provide an effect similar to that of the embodiment of FIG. 6 (i.e. the bowed plates 22 are vertically recessed). As was described in connection with the embodiment of FIG. 2, the arrangement of FIG. 7 (and FIG. 8) may employ sheet or strip material connected by brazing to the tie bars 29'. Appropriately shaped cutouts (not seen) are provided in the upper and lower edges of each of bowed blades 22 to accept the (round) shape o tie bars 19' and 29'.
The described invention is considered to be effective to trap debris having a cross-sectional area greater than about 0.100 inches and to trap most wire debris longer than about 0.50 inches, whereas prior art anti-debris devices have been found to be generally ineffective for trapping wire. In general, wire debris has been observed to align with the direction of coolant flow and, since there is no direct line of sight through the spaces 25 in the arrangements described herein, wires entering the spaces 25 will approach the point of inflection in the spaces 25 at a substantial angle to the direction of coolant flow out of that point. The wires are then unable to follow the change in coolant flow direction and will be trapped. A similar effect occurs with other debris as well.
Apparatus according to this invention may be incorporated into lower tie plates for new fuel stacks or advantageously may be retrofit into irradiated fuel by, for example, employing appropriate spring clips or latches to attach the unit to existing lower tie plate corner posts as is partially shown in FIG. 7.
In general, the planar area of solid members which make up a screen as described above constitutes approximately twenty-five percent of the total available flow area, which will generally result in an increased pressure drop of acceptable magnitude. Certain installations are capable of accommodating greater pressure drops than others and, in that case, a cast arrangement such as is shown in FIGS. 4-6 may be employed.
Various modifications within the scope of this invention readily may occur to persons skilled in this art and the scope of the invention is set forth in the following claims.
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A debris screen for a fuel assembly for a reactor to which coolant fluid is supplied comprises a substantially planar plate member having an array of coollant openings extending through the plate member dimensioned to trap at least a portion of debris particles carried by the coolant; and a skirt member enclosing the periphery of the plate member; each of the coolant flow openings having a coolant entry region at a lower surface, a coolant exit region at an upper surface and a coolant flow path extending between the entry and exit regions, the flow path including an intermediate segment laterally offset from the entry and exit regions to cause coolant to change direction of flow in the intermediate segment and thereby prevent at least a portion of the debris particles from passing through the plate members.
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TECHNICAL FIELD
The present invention relates to a device for controlling the capacity of a variable capacity type compressor in an automotive air conditioning system, and more particularly, to a device which controls the capacity of the compressor in accordance with the air conditioning load.
BACKGROUND OF THE INVENTION
Generally, the air conditioning system of an automobile is driven by the vehicle engine through an electromagnetic clutch. The air conditioning system is designed to achieve a predetermined air conditioning performance at a predetermined air conditioning load when the automobile is driven at an average speed. Thus, when the vehicle engine is idling or is being driven at low speeds, the rotational speed of the compressor is correspondingly low. Therefore, the performance of the air conditioning system is adversely effected. On the other hand, when the vehicle is driven at high speeds, the rotational speed of the compressor is to high for efficient performance. Thus, electromagnetic clutches are used to control the rotational speed of the compressor under varying drive speeds by intermittently stopping and starting the compressor.
However, there are many problems associated with continuously cycling the clutch on and off. For example, when the engine is driven at high speeds and the capacity of the air conditioning system is large, it is necessary for the electromagnetic clutch to be turned on or off frequently. On the other hand, at low speed or when the vehicle engine is idling, the compressor is not sufficiently driven to maintain the desired temperature in the vehicle.
In order to solve the abovementioned problems, a system which controls the capacity of a compressor by detecting the temperature at the outlet side of the air conditioning system evaporator is proposed in published Japanese Patent Application No. 58-30. In such a system, the performance of the air conditioning system is not directly detected. For example, even though the temperature in the inside of the vehicle may be high, the capacity of the air conditioning system is reduced when the temperature at the outlet side of the evaporator becomes lower than a predetermined temperature. Thus, the capacity of the system is insufficient to cool the vehicle. In addition, when the vehicle is running, the capacity of the air conditioning system is changed frequently, thereby placing great stress and strain on the air conditioning system.
SUMMARY OF THE INVENTION
It is therefore the overall object of the present invention to provide a device for controlling the capacity of a variable type compressor in an automotive air conditioning system in order to provide a more reliable and durable system than those known in the prior art.
It is another object of the present invention to provide a more reliable and durable automotive air conditioning system than those known in the prior art without increasing the complexity or cost of the system.
The above objects of the present invention are achieved by providing a control device which includes a first temperature detecting sensor disposed forward of the evaporator for detecting a first air temperature at the inlet side of the evaporator, a second temperature detecting sensor disposed behind the evaporator for detecting a second air temperature at the outlet side of the evaporator and a control unit. The control unit compares the detected air temperature with predetermined temperatures and controls the capacity of the compressor in accordance with the compared results.
Further objects, features and advantages of the present invention will be understood from the following detailed description of the preferred embodiments of the invention with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an automotive air conditioning system in accordance with the present invention.
FIG. 2 is a flow chart illustrating the operation of the control system of the present invention.
FIG. 3 is a graph illustrating the relationship between a high air conditioning load and normal vehicle speed.
FIG. 4 is a graph illustrating the relationship between a high air conditioning load and high vehicle speed.
FIG. 5 is a graph illustrating the relationship between a low air conditioning load and normal vehicle speed.
FIG. 6 is a graph illustrating the relationship between a low air conditioning load and high vehicle speed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, there is shown an automotive air conditioning system which is driven by engine 1. The air conditioning system comprises compressor 1, condenser 3, receiver-dryer 4, expansion valve 5 and evaporator 6 located between outlet port 21 and inlet port 22. Compressor 2 is driven by engine 1 and is a variable capacity compressor of the scroll type or swash plate type design. The capacity of compressor 2 can be varied by operating capacity changing mechanism 11 upon a signal from control unit 10. Where compressor 2 is of the scroll type, capacity changing mechanism 11 comprises an electromagnetic bypass valve which connects the inlet of the compressor to the intermediate fluid pockets through an intermediate chamber as shown in published Japanese Patent Application No. 57-148089.
As shown in FIG. 1, evaporator 6 is disposed in duct 7. Sensor 8 is disposed at the inlet side of evaporator 6 and sensor 9 is disposed at the outlet side of evaporator 6. Sensors 8 and 9 are connected to control unit 10. Control unit 10 compares the detected temperature valves with predetermined values and then sends appropriate capacity control signals to capacity changing mechanism 11 to effect a change in the capacity of the compressor or to start or stop the operation of the compressor.
Heater 12 disposed in duct 7 is connected to engine 1 and receives coolant from engine 1 for heating the vehicle when the outside temperature is cold.
A damper 13 disposed forward of heater 12 controls the temperature of the discharged air by the angle of its opening being controlled. Blower 14 is also disposed forward of evaporator 6. With reference to FIG. 2, there is shown a flowchart which illustrates the operation of control unit 10.
When the air conditioning system is turned on in step 1, compressor 2 is operated at a predetermined small capacity (step 2). After the air conditioning system is operated for a predetermined time T (step 3), control passes to step 4. In the present invention time T may be, e.g., three seconds. In step 4, temperature TODB is detected by sensor 9 at the outlet side of evaporator 6 and is compared to predetermined temperature T4 in step 5. If the temperature TODB is higher than temperature T4, control pases to step 7. If temperature TODB is equal to or lower than temperature T4 control passes to step 6.
In step 6, a determination is made whether compressor 2 is operating. If compressor 2 is operating, control passes back to step 4. If, however, compressor 2 is not operating, control passes to step 7.
In step 7, temperature T air is detected by sensor 8 at the inlet side of evaporator 6. A predetermined temperature T1 is substracted from temperature T air and the resulting temperature is compared with a predetermined change in temperature ΔT. If the resulting temperature is greater than temperature ΔT, control passes to step 11 where the capacity of the compressor is changed to a high capacity. Control is then passed to step 16. If the resulting temperature is not greater than temperature ΔT, control is passed to step 8.
In step 8, temperature T air is compared to predetermined temperature T1 and if T air is greater than T1, control passes to step 10. Otherwise, control passes to step 9. In step 10, a predetermined temperature T2 equal to T2 MIN is established and control is passed to step 12. In step 9, a predetermined temperature T2 equal to T2 MAX is established and control is also passed to step 12.
In step 12, temperature TODB is compared to temperature T2 and if T2 is greater than TODB, control is passed to step 14 otherwise control is passed to step 13. In step 13, the capacity of compressor 2 is changed to a large capacity and control returns to step 4. In step 14, temperature TODB is compared to predetermined temperature T3 and if TODB is greater than T3, control is passed to step 15. In step 15, the capacity of compressor 2 is changed to a small capacity and control passes to step 16.
In step 16, temperature TODB is compared to predetermined temperature T5 and if TODB is greater than T5 control is returned to step 4. Otherwise, control is passed to step 17. In step 17, the operation of the compressor is stopped, e.g., by deactivating the electromagnetic clutch. Control is then returned to step 4.
FIGS. 3, 4, 5 and 6, shown the relationship between air conditioning load, temperature and compressor torque over time. The solid lines represent a compressor controlled in the manner of the present invention and the dotted line represents a compressor controlled in the manner known in the prior art by cycling the electromagnetic clutch. As the figures clearly show, the present invention provides an air conditioning system which is more efficient in its operation and more responsive to variations than such systems known in the art.
The invention has been described in detail in connection with preferred embodiments. These embodiments are examples only and the invention is not restricted thereto. It will be easily understood by those skilled in the art that variations and modifications can be made to the invention within the scope of the appended claims.
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A control device for a variable capacity compressor in an automotive air conditioning system. The control device includes a first sensor disposed forward of the evaporator and a second sensor disposed behind the evaporator. The control device compares the air temperature detected by the sensors with predetermined temperatures, and controls the capacity of the compressor in accordance with the compared results.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to the commonly assigned, copending U.S. application Ser. No. 06/560,999, filed Dec. 13, 1983, and entitled: "GEAR MEASURING FEELER", now U.S. Pat. No. 4,528,758, granted July 16, 1985, and the commonly assigned, copending U.S. application Ser. No. 06/682,089, filed Dec. 17, 1984, and entitled "TOOTH FLANK PROFILE MEASURING APPARATUS CONTAINING A FEELER FOR DETERMINING THE SURFACE ROUGHNESS OF A TOOTH FLANK," now U.S. Pat. No. 4,552,014, granted Nov. 12, 1985.
BACKGROUND OF THE INVENTION
The present invention relates to a new and improved construction of gear measuring feeler.
In its more particular aspects, the present invention relates specifically to a new and improved construction of gear measuring feeler including a feeler rod which is pivotably mounted in a housing. This feeler rod supports a feeler probe at one of its ends and, at the other one of its ends, one of two relatively movable members of a measuring system. The measuring system generates a magnetic field and delivers electrical signals which are proportional to the deflection of the feeler probe, to a matching circuit standardizing the electrical signals. The two relatively movable members of the measuring system comprise means for generating a static magnetic field and a Hall-effect sensor, respectively, and the matching circuit is mounted at the housing.
In such a gear measuring feeler, as disclosed in the aforementioned commonly assigned, copending U.S. application Ser. No. 06/560,999, now U.S. Pat. No. 4,528,758 the matching circuit or electronic component 56 which is connected to the output of the Hall-effect sensor 50 essentially comprises a zero compensation circuit 74 and two series-connected operational amplifiers 76 and 78. The zero compensation accomplished by means of the zero compensation circuit 74 is required in such gear measuring feeler because the Hall-effect sensor 50 is only operated at one d.c.-voltage level, whereas during measurements at tooth flanks with such gear measuring feeler a deflection of the feeler probe must be measured from a pre-adjusted zero position in the plus-direction or minus-direction. Since, on the one hand, only a unidirectional voltage is present in the form of the d.c.-voltage and since, on the other hand, the measured voltage at the output should be as informative as possible, i.e. a deflection, for instance, to the left should generate a positive voltage and a deflection to the right a negative voltage, the output voltage of the Hall-effect sensor 50 must be symmetrized. For this purpose the zero compensation circuit 74 supplies a voltage which is added to the output voltage of the Hall-effect sensor 50 before this output voltage is fed to the operational amplifier 76. The zero compensation circuit 74 contains a reference voltage transmitter 80 which supplies a thermally stable voltage independently of eventual fluctuations of its current supply source. Furthermore, the zero compensation circuit contains a potentiometer P2 at which the zero compensation voltage can be adjusted such that no mechanical fine adjustment or tuning of the measuring system is required.
Uncertainties with respect to the measuring result can occur in the gear measuring feeler according to the initially cross-referenced commonly assigned, copending U.S. patent application if the zero compensation circuit 74 and the remaining parts of the measuring circuit do not have exactly the same temperature drift. Common mode or in-phase voltages can result from the Hall-effect sensor which must be suppressed by special additional measures. It has furthermore been found that the measuring result could be further improved if it were possible to increase the output voltage of the Hall-effect sensor, i.e. its sensitivity in terms of millivolt per micrometer feeler probe deflection.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind it is a primary object of the present invention to provide a new and improved gear measuring feeler in which no measuring uncertainty is caused by temperature drift effects within the measuring circuit.
Another important object of the present invention is directed to the provision of a new and improved gear measuring feeler in which common mode or in-phase voltages can be suppressed in a more simple manner.
Still a further important object of the present invention is directed to the provision of a new and improved gear measuring feeler in which a higher output voltage of the Hall-effect sensor is obtained.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the gear measuring feeler of the present development is manifested by the features that, the Hall-effect sensor has a differential output, and the matching circuit is designed as a differential amplifier circuit.
By using the inventive Hall-effect sensor with a differential output the reference voltage source can be dispensed with and which is otherwise required in the matching circuit or electronic component of the gear measuring feeler disclosed in the initially cross-referenced U.S. patent application Ser. No. 06/560,999. There are achieved the following further advantages: the measuring output voltage of the Hall-effect sensor floats with respect to zero volt. The measuring voltage thus generated, therefore, can be measured in a differential mode. Common mode or in-phase voltages are thus suppressed by means of the differential amplifier circuit. Consequently, the measurements will be more precise because uncertainties which originate from different temperature coefficients, for instance of the Hall-effect sensor and of the reference voltage source, are eliminated and because twice the absolute value of the measuring output voltage is available.
Preferably, the Hall-effect sensor can be provided in a simple manner by simply mechanically and fixedly interconnecting two identical Hall-effect sensor elements of the kind as used in the gear measuring feeler according to the initially cross-referenced U.S. patent application Ser. No. 06/560,999. The two Hall-effect sensor elements are interconnected in such a manner that their Hall-effect generators are arranged in opposing relationship to each other with respect to the magnetic field.
In a further preferred embodiment of the invention a dual Hall-effect sensor is obtained by simply securing to each other two conventional Hall-effect sensors at the same sides thereof.
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 figures of the drawings there have been generally used the same reference characters to denote the same or analogous components and wherein:
FIG. 1 is a block circuit diagram showing the principle of the circuit structure in the inventive gear measuring feeler;
FIG. 2 is a partial sectional view of an exemplary embodiment of the inventive gear measuring feeler; and
FIG. 3 is an electrical circuit diagram showing the circuit structure of the gear measuring feeler illustrated in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that only enough of the construction of the gear measuring feeler has been shown as needed for those skilled in the art to readily understand the underlying principles and concepts of the present development, while simplifying the showing of the drawings. Turning attention now specifically to FIG. 1, there has been schematically illustrated a Hall-effect sensor 50 having a differential output and the output signal of which is processed in a matching circuit which is designed as a differential amplifier circuit 56. In the most simple case the Hall-effect sensor 50 illustrated in FIG. 1 may comprise two Hall-effect generators which are arranged in space in such a manner as to be in opposing relationship with respect to the direction of the magnetic field. The opposing spatial relationship between the two Hall-effect generators results in the generation of the desired differential output signal. In comparison to a Hall-effect sensor comprising only one Hall-effect generator the inventive Hall-effect sensor containing two Hall-effect generators and a differential output generates twice as large an output signal and there thus results an improved signal-to-noise ratio.
The differential amplifier circuit 56 illustrated in FIG. 1 may be of known design. In the following a specific construction of the differential amplifier circuit 56 is described which is particularly suited for use in combination with the exemplary embodiment of the gear measuring feeler illustrated in FIG. 2. In this specific design the Hall-effect sensor essentially consists of two separate Hall-effect sensor elements 50A and 50B which are spatially in opposing relationship to each other and which are firmly interconnected on the same sides thereof.
FIG. 2 shows part of a longitudinal sectional view of an exemplary embodiment of the gear measuring feeler in which the section is in the horizontal pivoting plane of a feeler rod 10. This feeler rod 10 is pivotably mounted in a housing 14, so as to be deflectable from a predetermined position. This pivotable mounting of the feeler rod 10 is described in detail in the initially cross-referenced U.S. patent application Ser. No. 06/560,999 and thus such description thereof is incorporated herein by reference in order to avoid undue repetition.
The measuring system of the gear measuring feeler comprises the Hall-effect sensor which is designated in its entirety by reference numeral 50, two permanent magnets 54 which are arranged in a magnet support 52 on two diametrically opposed sides of the Hall-effect sensor 50 and in a spaced relationship thereto, and a matching circuit 56 forming an electronic component or part with connecting sockets 58 into which related connecting pins 60 of the Hall-effect sensor 50 are inserted. As described in the initially cross-referenced U.S. patent application Ser. No. 06/560,999, the permanent magnets 54 constitute robust magnets made of a samarium-cobalt alloy which generate a very high field strength or intensity and which have a particularly high long-term stability. The magnet support 52 is fixedly connected to the second end 10B of the feeler rod 10 which is the right-hand end in FIG. 2 and which second end 10B is located remote from a first end 10A of the feeler rod 10 which carries a feeler probe 12. The permanent magnets 54 are arranged at the magnet support 52 in such a manner that the like poles of the permanent magnets 54 face each other.
The Hall-effect sensor 50 illustrated in FIG. 2 comprises the two Hall-effect sensor elements 50A and 50B, each of which constitutes an integrated circuit on a ceramic plate or platelet containing the actual Hall-effect generator as well as a voltage regulator and an amplifier VS, see also FIG. 3. The electric circuits arranged at the ceramic plates or platelets are connected via the connecting pins 60 and the connecting sockets 58 to the differential amplifier circuit 56 which will be described hereinbelow with reference to FIG. 3. The two ceramic plates or platelets are adhesively bonded to each other in such a manner that the Hall-effect generators of the two Hall-effect sensor elements 50A and 50B are rotated by 180° with respect to each other, i.e. with respect to the magnetic field generated by the permanent magnets 54 the Hall-effect sensor elements 50A and 50B are spatially arranged in opposing relationship. The Hall-effect sensor 50 is mounted at a holder 66 which, in turn, is secured to the housing 14 of the gear measuring feeler. This holder 66 may be made of, for instance, light metal or a light metal alloy. The Hall-effect sensor 50 is thereby immovably mounted at the gear measuring feeler, whereas the magnet holder 52 moves relative to the Hall-effect sensor 50 when the feeler rod 10 is pivoted or deflected. The differential amplifier circuit 56 is also immovably mounted due to the connecting pins 60 which are inserted into the connecting sockets 58. If desired, an additional mounting member for the electronic part containing the differential amplifier circuit 56 can be provided at the holder 66. The output of the differential amplifier circuit 56 is connected to connecting sockets of the gear measuring feeler via connecting wires or leads 72.
The structure of the circuit containing the Hall-effect sensor 50 and the differential amplifier circuit 56 is shown in FIG. 3. The Hall-effect sensor 50 comprises the two Hall-effect sensor elements 50A and 50B which are connected in parallel to a suitable voltage supply source. Since each one of the two Hall-effect sensor elements 50A and 50B constitutes a conventional element, the structure thereof need not be here described in detail. In FIG. 3 only the amplifier VS is indicated which is already integrated with each one of the Hall-effect sensor elements 50A and 50B.
The differential amplifier circuit 56 receives the differential output signals H1 and H2, respectively, of the Hall-effect sensor elements 50A and 50B and delivers at its output A a signal with respect to zero volt and which corresponds to the differential output signal of the Hall-effect sensor 50. In the presently illustrated exemplary embodiment the differential amplifier circuit 56 contains an inverter circuit 77 and an operational amplifier 78. The output of the Hall-effect sensor element 50A is connected via a resistor R1 to the inverting input (-) of the operational amplifier 78. The output of the operational amplifier 78 is feed-back connected to this inverting input (-) thereof via a potentiometer P1 for adjusting the gain and via a connection point or junction X. The non-inverting input (+) of the operational amplifier 78 is connected to the zero-volt side OV of the voltage supply source via a resistor R2.
The output of the Hall-effect sensor element 50B is connected to the input of the inverter circuit 77 and the output of which is connected via a resistor R3 to the connecting point or junction X, and thus, to the inverting input (-) of the operational amplifier 78. The inverter circuit 77 contains an inverting amplifier 75.
The output of the Hall-effect sensor element 50B is connected via a resistor R4 to the inverting input (-) of the inverting amplifier 75, the output of which is feed-back connected to this inverting input (-) via a resistor R5. The non-inverting input (+) of the inverting amplifier 75 is connected to the zero volt side OV of the voltage supply source via a resistor R6. It is a specific feature of the inverter circuit 77 that the amplification or gain thereof amounts to 1.
During operation the output signal H1 of the Hall-effect sensor element 50A is directly supplied via the resistor R1 to the inverting input (-) of the operational amplifier 78 while there is also supplied to this inverting input (-) the output signal of the Hall-effect sensor element 50B via the inverter circuit 77 and the resistor R3, i.e. in the inverted from H2. The operational amplifier 78 thus receives at its inverting input (-) the sum of the magnitudes or levels of the two output signals of the Hall-effect sensor elements 50A and 50B and delivers, after desired amplification, this sum as the output signal at the output A thereof. The inverting amplifier 75 and the operational amplifier 78 which are contained in the illustrated differential amplifier circuit 56 can also be designed as an integrated circuit. In the presently described gear measuring feeler the zero-point adjustment is not effected in an electrical manner as provided in the gear measuring feeler according to the initially cross-referenced U.S. patent application Ser. No. 06/560,999, but is obtained in a mechanical manner by appropriately adjusting the Hall-effect sensor 50 between the permanent magnets 54 in order to thus realize a simple design of the matching circuit 56.
In the embodiment of the inventive gear measuring feeler and as illustrated in FIG. 3, the following elements or components have been used:
______________________________________Reference Electrical Num.Numeral Component Value Type______________________________________75, 78 Inverting and IC 1458 Operational AmplifierP1 Wire Potentiometer 10R1 Resistor 10R2 Resistor 5.1R3 Resistor 10R4 Resistor 10R5 Resistor 10R6 Resistor 5.150A, 50B Hall-effect Sensor 92 SS 12.2 Elements (Honeywell)______________________________________
The resistances are given in kiloohms and each resistor is a film resistor having an electrical power of 1/8 watt.
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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The measuring system of the gear measuring feeler contains, as a Hall-effect sensor, two Hall-effect sensor elements which are arranged in opposing relationship to each other in the magnetic field. The differential output signal of this dual Hall-effect sensor is processed in a matching circuit which is designed as a differential amplifier circuit, to yield a measuring voltage with respect to zero volt. This measuring voltage is twice as high as in the case where only one Hall-effect sensor element is used as the Hall-effect sensor. Furthermore, the matching circuit is of a simpler structure and the measurement is substantially more precise since there is not required any reference voltage source in the matching circuit.
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BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to turbine engines and, more specifically, to assembly, support, and alignment of components of the turbine engines.
[0002] In certain applications, turbines may include various sections designed to be assembled during installation. Each turbine may be encased by a turbine shell and its bearings supported by a “standard” (also referred to as a “pedestal) or exhaust frame. The turbine shells may include arms or other extensions that may be supported by the standard, such as through a vertical support on the standard itself. The turbine shells may also be vertically supported by legs that attach to ground.
[0003] A bearing housing generally covers and protects the bearings of the turbine. During installation, the bearing housing is positioned such that the rotor is concentric with the turbine shell to avoid interference with the other components. Supports on the exhaust frame may engage a support part on the bearing housing to vertically and/or horizontally align and support the bearing housing. Clearances may increase or decrease during operation depending on the support of the exhaust frame and the bearing housing support part. These changes in clearance may introduce uncertainty in the position of the bearing relative to the stationary components and may result in rubbing or interference between such components.
[0004] The turbine shell generally covers and protects the rotary components of the turbine. During installation, the turbine shell is generally aligned with rotary components to avoid interference with the components. Supports to ground may engage a support part on the turbine shell to vertically and/or horizontally align and support the turbine shell. Achieving desired clearances may be difficult due to thermal expansion of the support part and/or the support of the standards. For example, clearances may increase or decrease during operation depending on the configuration of the support of the standard and the support part. These changing clearances may introduce uncertainty in the position of the turbine shell relative to the rotary components and may eventually result in rubbing or interference between such components.
BRIEF DESCRIPTION OF THE INVENTION
[0005] Certain embodiments commensurate in scope with the originally claimed invention are summarized below. These embodiments are not intended to limit the scope of the claimed invention, but rather these embodiments are intended only to provide a brief summary of possible forms of the invention. Indeed, the invention may encompass a variety of forms that may be similar to or different from the embodiments set forth below.
[0006] In a first embodiment, a system includes a turbine engine having a turbine shell, a support assembly configured to support the turbine engine, wherein the support assembly comprises a keyway defined by at least first and second protrusions, a gib extending from the turbine shell and configured to mate with the keyway and a first shim disposed between the gib and one of the first protrusion, wherein the first shim comprises a metal foam.
[0007] In a second embodiment, a system a first turbine alignment component for a turbine engine and a shim comprising a metal foam, wherein the shim mounts between a first surface of the first turbine alignment component and a second surface of a second turbine alignment component.
[0008] In a third embodiment, a system includes a support feature for a turbine engine having a keyway having a bottom, a first side, and a second side opposite from the first side; a key configured to insert in the keyway and provide lateral alignment of a turbine shell of the turbine engine, and a first shim disposed in the keyway between the key and the first side, and a second shim disposed between the key and the second side, wherein the first shim and the second shim comprise a metal foam.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
[0010] FIG. 1 is a schematic flow diagram of an embodiment of a combined cycle power generation system having a gas turbine, a steam turbine, and a heat recovery steam generation (HRSG) system;
[0011] FIG. 2 is a perspective view of a turbine standard and a turbine shell in accordance with an embodiment of the present invention;
[0012] FIG. 3 is a schematic front view of a turbine support feature in accordance with an embodiment of the present invention;
[0013] FIG. 4 is a stress/strain curve of a metal foam in accordance with an embodiment of the present invention;
[0014] FIG. 5 is a perspective view of a keyway protrusion of the turbine support feature of FIG. 3 in accordance with an embodiment of the present invention; and
[0015] FIG. 6 is a perspective view of a keyway protrusion of the turbine support feature of FIG. 3 in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
[0017] When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
[0018] Embodiments of the present invention include a compliant shim (e.g., a metal foam shim) for aligning turbine components, e.g., turbine shells, of a steam or gas turbine, that are supported on a turbine support, e.g., a standard. The metal foam shim may be installed as a shim between a keyway of a turbine component and a gib of a turbine support. During operation, the metal foam shim may compress in response to thermal expansion of the hot turbine component to ensure that the desired clearances remain between the keyway and the gib. In some embodiments, a wear pad, e.g., a stellite wear pad, may be provided between the metal foam shim and the keyway to support any shear load exerted by the gib and/or the keyway. In certain embodiments, the thickness, relative density, and material for the metal foam shim may be chosen to ensure that the metal foam shim provides desired linear elasticity and long operating life.
[0019] FIG. 1 is a schematic flow diagram of an embodiment of a combined cycle power generation system 10 having a gas turbine 12 , a steam turbine 22 , and a heat recovery steam generation (HRSG) system 32 . System 10 may employ one or more support features to align various components in the gas turbine 12 , the steam turbine 22 , and/or the HRSG 12 . As discussed below, the support features include one or more compliant shims (e.g., metal foam shims) to maintain suitable clearances despite thermal expansion of hot turbine components.
[0020] The system 10 may include the gas turbine 12 for driving a first load 14 . The first load 14 may, for instance, be an electrical generator for producing electrical power. The gas turbine 12 may include a turbine 16 , a combustor or combustion chamber 18 , and a compressor 20 . The system 10 may also include the steam turbine 22 for driving a second load 24 . The second load 24 may also be an electrical generator for generating electrical power. However, both the first and second loads 14 , 24 may be other types of loads capable of being driven by the gas turbine 12 and steam turbine 22 . In addition, although the gas turbine 12 and steam turbine 22 may drive separate loads 14 and 24 , as shown in the illustrated embodiment, the gas turbine 12 and steam turbine 22 may also be utilized in tandem to drive a single load via a single shaft. In the illustrated embodiment, the steam turbine 22 may include one low-pressure section 26 (LP ST), one intermediate-pressure section 28 (IP ST), and one high-pressure section 30 (HP ST). However, the specific configuration of the steam turbine 22 , as well as the gas turbine 12 , may be implementation-specific and may include any combination of sections.
[0021] Each section of the steam turbine 22 , e.g., the low pressure section 26 , the intermediate pressure section 28 , and the high-pressure section 30 , may be generally supported and separated by mid standards 29 (e.g., pedestals). Similarly, end standards 31 (e.g., pedestals) may be generally support the ends of the high pressure section 30 and the low pressure section 26 . The standards 29 and 31 may be disposed along the axis of the turbine 22 , and may include various components such as supports, pickups, and piping between the turbine sections 26 , 28 , and 30 . As described in detail below, the standards 29 and 31 may also provide for lateral (i.e., horizontal) alignment of the turbine shells of the sections 26 , 28 , and 30 , though engagement of a gib and keyway. The engagement between the gib and the keyway may be adjusted through the use the metal foam shims described herein. It should be appreciated that the gas turbine 12 may also include a similar arrangement of one or more sections and standards, and the gas turbine 12 may also utilize a gib, keyway, and metal foam shims for lateral alignment, as discussed below.
[0022] The system 10 may also include the multi-stage HRSG 32 . The components of the HRSG 32 in the illustrated embodiment are a simplified depiction of the HRSG 32 and are not intended to be limiting. Rather, the illustrated HRSG 32 is shown to convey the general operation of such HRSG systems. Heated exhaust gas 34 from the gas turbine 12 may be transported into the HRSG 32 and used to heat steam used to power the steam turbine 22 . Exhaust from the low-pressure section 26 of the steam turbine 22 may be directed into a condenser 36 . Condensate from the condenser 36 may, in turn, be directed into a low-pressure section of the HRSG 32 with the aid of a condensate pump 38 .
[0023] The condensate may then flow through a low-pressure economizer 40 (LPECON), a device configured to heat feedwater with gases, which may be used to heat the condensate. From the low-pressure economizer 40 , a portion of the condensate may be directed into a low-pressure evaporator 42 (LPEVAP) while the rest may be pumped toward an intermediate-pressure economizer 44 (IPECON). Steam from the low-pressure evaporator 42 may be returned to the low-pressure section 26 of the steam turbine 22 . Likewise, from the intermediate-pressure economizer 44 , a portion of the condensate may be directed into an intermediate-pressure evaporator 46 (IPEVAP) while the rest may be pumped toward a high-pressure economizer 48 (HPECON). Steam from the intermediate-pressure evaporator 46 may be sent to the intermediate-pressure section 28 of the steam turbine 22 . Again, the connections between the economizers, evaporators, and the steam turbine 22 may vary across implementations as the illustrated embodiment is merely illustrative of the general operation of an HRSG system that may employ unique aspects of the present embodiments.
[0024] Finally, condensate from the high-pressure economizer 48 may be directed into a high-pressure evaporator 50 (HPEVAP). Steam exiting the high-pressure evaporator 50 may be directed into a primary high-pressure superheater 52 and a finishing high-pressure superheater 54 , where the steam is superheated and eventually sent to the high-pressure section 30 of the steam turbine 22 . Exhaust from the high-pressure section 30 of the steam turbine 22 may, in turn, be directed into the intermediate-pressure section 28 of the steam turbine 22 . Exhaust from the intermediate-pressure section 28 of the steam turbine 22 may be directed into the low-pressure section 26 of the steam turbine 22 .
[0025] An inter-stage attemperator 56 may be located in between the primary high-pressure superheater 52 and the finishing high-pressure superheater 54 . The inter-stage attemperator 56 may allow for more robust control of the exhaust temperature of steam from the finishing high-pressure superheater 54 . Specifically, the inter-stage attemperator 56 may be configured to control the temperature of steam exiting the finishing high-pressure superheater 54 by injecting cooler feedwater spray into the superheated steam upstream of the finishing high-pressure superheater 54 whenever the exhaust temperature of the steam exiting the finishing high-pressure superheater 54 exceeds a predetermined value.
[0026] In addition, exhaust from the high-pressure section 30 of the steam turbine 22 may be directed into a primary re-heater 58 and a secondary re-heater 60 where it may be re-heated before being directed into the intermediate-pressure section 28 of the steam turbine 22 . The primary re-heater 58 and secondary re-heater 60 may also be associated with an inter-stage attemperator 62 for controlling the exhaust steam temperature from the re-heaters. Specifically, the inter-stage attemperator 62 may be configured to control the temperature of steam exiting the secondary re-heater 60 by injecting cooler feedwater spray into the superheated steam upstream of the secondary re-heater 60 whenever the exhaust temperature of the steam exiting the secondary re-heater 60 exceeds a predetermined value.
[0027] In combined cycle systems such as system 10 , hot exhaust gas 34 may flow from the gas turbine 12 and pass through the HRSG 32 and may be used to generate high-pressure, high-temperature steam. The steam produced by the HRSG 32 may then be passed through the steam turbine 22 for power generation. In addition, the produced steam may also be supplied to any other processes where superheated steam may be used. The gas turbine 12 cycle is often referred to as the “topping cycle,” whereas the steam turbine 22 generation cycle is often referred to as the “bottoming cycle.” By combining these two cycles as illustrated in FIG. 1 , the combined cycle power generation system 10 may lead to greater efficiencies in both cycles. In particular, exhaust heat from the topping cycle may be captured and used to generate steam for use in the bottoming cycle.
[0028] FIG. 2 is a perspective view of a turbine standard 70 , e.g., a mid standard 29 or end standard 31 , supporting a turbine shell 72 , e.g., a shell of the low pressure section 26 , the intermediate pressure section 28 , or the high-pressure section 30 . The standard 70 may include an upper half 74 and a lower half 76 , and the turbine shell 72 may include an upper half turbine shell 78 or a lower half turbine shell 80 . The turbine shell 72 may be generally supported and aligned by a support feature disposed on the standard 70 , such as in the region indicated by arrow 79 . The support feature may laterally align and support the turbine shell 72 along the x-axis, such as in the directions indicated by arrows 81 , through engagement of a gib and keyway and adjustment of one or more metal foam shims. As noted above, the gas turbine 12 may also use a support feature to laterally align one or shells of the gas turbine with standards in a similar manner.
[0029] FIG. 3 is a schematic view of a turbine support feature 82 in accordance with an embodiment of the present invention. As shown in FIG. 3 , the turbine support feature 82 may include a keyway 84 on the standard 70 and a protrusion, e.g., gib 86 (also referred to as a “key”), extending from the lower turbine shell half 80 . They keyway 84 may be defined by protrusions 88 extending from the standard 70 . The space 83 between the protrusions 88 may define the keyway 84 . In some embodiments, the protrusions may be machined from the standard 70 , welded onto the standard 70 , or manufactured by any suitable technique. The gib 86 is configured to mate with the keyway 84 and provide alignment and support of the turbine shell 72 along the x-axis.
[0030] The clearance between the keyway 84 and the gib 86 may be set during “cold” conditions, e.g., when the turbine section is not in operation and is below operating temperatures. For example, some lateral clearance may be provided between the protrusions of the keyway 84 and the gib 86 to prevent damage to the gib 86 . During operation, as the turbine section and the turbine shell 72 heat, the gib 86 may thermally expand inside the keyway 84 . To ensure the desired fit between the gib 86 and the keyway 84 , one or more compliant shims (e.g., metal foam shims) 90 may be disposed between the gib 86 and each protrusion 88 that define the keyway 84 . For example, as shown in FIG. 3 , a first metal foam shim 90 A may be inserted between one side of the gib 86 and the protrusion 88 , and a second metal foam shim 90 B may be inserted between a second side of the gib 86 and the protrusion 88 . As the turbine shell 70 heats and the gib 86 grows within the keyway 84 , the metal foam shims 90 may be compressed to maintain the desired clearances between the gib 86 and the sides of the keyway 84 .
[0031] As described further below, the metal foam shims 90 may include FeCrAlY foams, stainless foams, copper foams, Inconel foams, nickel foams, aluminum foams, or any suitable foam, and the thickness, relative density, and material for the metal foam may be selected to ensure that the metal foam maintains linear elasticity in response to the forces exerted by the expanding gib 86 . Further, the metal foam shims 90 may be compliant enough to prevent damage to the gib 86 and/or the keyway 84 during thermal expansion of gib 86 , yet retain enough stiffness to maintain a desired lateral alignment between the gib 86 and the keyway 84 and, thus, maintain alignment of the turbine shell 70 . Advantageously, the metal foam enables adjustment of the support feature when cold to provide easier assembly. Additionally, the metal foam shim 90 in the support feature eliminates or minimizes any cold or hot lateral position uncertainty and enables achievement of tighter clearances between static and rotating parts of the turbine.
[0032] As mentioned above, the metal foam may be selected to provide the desired linear elasticity, such as by selecting a metal foam having a desired yield strength or Young's modulus. As will be appreciated, both the yield strength and the Young's modulus may be a function of the relative density. FIG. 4 depicts a stress/strain curve 94 for an exemplary metal foam, e.g., an FeCrAlY metal foam having a 15% relative density. As shown in FIG. 4 , the y-axis corresponds to the stress (lbf/in 2 ) of the metal foam for a given strain (in/in) on the x-axis. The linear region 96 corresponds to those portion of the stress/strain curve of the FeCrAlY metal foam that exhibit a linear elasticity. For example, in the linear region depicted in FIG. 4 , the Young's modulus of a FeCrAlY metal foam may be approximately 61259 psi. Other regions may include a plateau region 98 in which the stress of the metal foam does not change with respect to the strain, and a densification region 99 in which the metal foam increases in density and stress rapidly increases in response to strain.
[0033] Thus, when selecting a metal foam for use as a shim in the manner described above, the metal foam may be selected to ensure that the metal foam provides linear elasticity up to the strain expected to be induced in the metal foam shim during operation of the turbine and expansion of the turbine shell 70 . As mentioned above, the metal foam may include FeCrAlY foams, stainless foams, copper foams, Inconel foams, nickel foams, aluminum foams, or any suitable metal foam. Further, the metal foam may be include open cell metal foams or closed cell metal foams. Additionally, the metal foams used may have a relative density of greater than about 5%, such as at least approximately 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or greater.
[0034] For example, referring to the gib 86 and keyway 84 described above in FIG. 3 , for a gib 86 having a width of approximately 6 inches, a height of approximately 8 inches, and a length of approximately 20 inches, and for a steady-state gib temperature of 600° F. and 300° F., the stress generated in a 15% relative density FeCrAlY metal foam, is about 860 psi and within the linear elastic region 96 depicted in FIG. 4 . In addition, for such an embodiment, the total lateral force generated on the metal foam is 137,600 lbf.
[0035] In some embodiments, the metal foam shim 90 may be used with additional components. FIG. 5 depicts a perspective view of an embodiment of the keyway protrusion 88 having a wear pad 100 and a keeper plate 102 , and FIG. 6 depicts a perspective view of the keyway protrusion 88 without the keeper plate 102 . As shown in FIG. 5 , the wear pad 100 may absorb some or all of the shear load, indicated by arrow 104 , exerted by the gib 86 on the keyway protrusion 88 . As shown in FIG. 6 , the wear pad 100 may be disposed between the metal foam shim 90 and the gib 86 . In some embodiments, the wear pad 100 may be stellite, steel, or any other suitable material or combination thereof. The keeper plate 102 may be used to retain the metal foam shim 90 and the wear pad 100 in alignment with the keyway protrusion 88 . For example, the keeper plate 102 may retain the wear pad 100 against any shear load exerted on the pad in the direction illustrated by arrow 104 . As also shown in FIGS. 5 and 6 , the wear pad 100 may be mechanically secured to the metal foam shim 90 by one or more fasteners 106 , such as nails, screws, bolts, rivets, or any other suitable fastener. In other embodiments, the wear pad 100 may be joined to the metal foam shim 90 with a braze, a weld, an adhesive, or any other suitable process. Thus, in some embodiments, the wear pad 100 and metal foam shim 90 may be joined together to form a single component, while in other embodiments the wear pad 100 may be a separate component from the metal foam shim 90 . In other embodiments, the wear pad 100 may be omitted and the metal foam shim 90 may be the only component disposed between the gib 86 and the keyway protrusion 88 . Similarly, the keeper plate 102 may be mechanically secured to the keyway protrusion 88 by one or more fasteners 108 , such as nails, screws, or any other suitable fastener. As also shown in FIG. 6 , the protrusion 88 may include a recess 110 configured to position and/or receive the shim 90 in a specific area of the protrusion 88 . This recess 110 may be defined by one or more indentations in or extensions of the inner surface of the protrusion 88 . In some embodiments, one or more protrusions 88 defining the keyway 84 may include a recess.
[0036] It should be appreciated that in other embodiments, the keyway may be located on the turbine shell 70 and the gib 86 may be located on the turbine standard. In such embodiments, the metal foam shim 90 may be used to provide desired clearances between the gib and keyway in the manner described above. Further, it should be appreciated that the compliant shims (e.g., metal foam shims) described above may be used in other support features having, for example, a first and second alignment feature, male and female alignment features, etc.
[0037] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
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A system is provided that includes a first turbine alignment component for a turbine engine; and a shim comprises a metal foam. The shim mounts between a first surface of the first turbine alignment component and a second surface of a second turbine alignment component.
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This application is a continuation-in-part of application Ser. No. 099,360, filed Sept. 21, 1987 abandoned. There are two other applications by the same inventors, entitled "Guidelineless Reentry System With Nonrotating Funnel", Ser. No. 106,837, filed Oct. 8, 1987 U.S. Pat. No. 4,825,879, and "Guidelineless Reentry System With Fixed Rollers", Ser. No. 106,838, filed Oct. 8, 1987 U.S. Pat. No. 4,838,878.
BACKGROUND OF THE INVENTION
1. Field of the Invention:
This invention relates in general to subsea wells, and in particular to a system for reconnecting a riser from a floating vessel to a subsea well for workover operations.
2. Description of the Prior Art:
In deep water offshore oil and gas wells, the Christmas tree of the well will often be located on the subsea floor. At times, a workover operation must be performed on the subsea well. When this is required, a floating vessel is positioned over the well. A string of riser pipe is lowered down into engagement with a mandrel on the subsea tree. Once in engagement, operations can be performed on the well.
If the system is a guidelineless system, there will be no guidelines extending upward from the subsea well structure to the surface. Generally, in a guidelineless system, a large upwardly facing funnel is mounted permanently on the subsea tree. The funnel, with the aid of television cameras, assists in guiding the lower end of the riser onto the mandrel of the subsea well. The funnel can be quite large, up to twelve feet in diameter. A funnel of this type is expensive to construct and is only used when a workover operation is performed or when a tree cap is installed.
Mounting a downward facing funnel on the riser would avoid the need for a permanent upward facing funnel on each well. However, a funnel rigidly mounted to the lower end of the riser would require an extra high mandrel extending above the control mechanisms on the tree, so as to insure that the funnel did not strike any of various control mechanisms on the side of the tree. Hydraulic connections must also be made up when the riser lands on a mandrel to connect the controls of the tree to the floating platform. Orienting the funnel onto the mandrel of the Christmas tree without damage to the hydraulic manifold or valve block would be a problem.
There have been proposals to make the funnel retractable. The funnel would be located on the lower end of the riser, but would be vertically movable relative to the lower end of the riser by means of hydraulic rams. When first contacting the mandrel on the subsea well, the funnel would be extended. Once proper orientation has been made, the funnel would be retracted. During retraction, the riser and mandrel connector lower down into engagement with the mandrel. While these proposals have merit, improvements are desirable.
SUMMARY OF THE INVENTION
In this invention, a guide frame is mounted to the mandrel below the top of the mandrel. A mandrel connector is mounted to the lower end of the riser. The mandrel connector includes dogs which move radially out to lock the mandre connector to the mandrel.
A guide funnel is carried by the riser for insertion over the mandrel. The guide funnel will move from a lower extended position to an upper position. A plurality of rollers are carried by the funnel. Once the funnel has landed, the rollers are extended from a retracted position. In the extended position, the rollers latch the funnel to the guide frame and also allow rotation of the funnel.
Once the proper orientation has been achieved, the mandrel connector is lowered along with the riser onto the mandrel by retracting the funnel. The dogs are then moved into engagement with the mandrel by means of the cam.
A hydraulic manifold encircles the mandrel within the guide ring. The hydraulic manifold has a plurality of passages leading to equipment on the subsea well. A manifold connector is carried by the mandrel connector. The manifold connector is connected to lines that lead to the surface for supplying hydraulic fluid. When the mandrel is connected to the mandrel, the manifold connector will seat against the hydraulic manifold.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a partial vertical sectional view illustrating a reentry system constructed in accordance with this invention, with the funnel positioned above the mandrel and in an extended position.
FIG. 2 is a partial sectional view of part of the deflector plate of the system of FIG. 1.
FIG. 3 is a partial vertical sectional view of the system of FIG. 1, showing the funnel latched to the guide frame.
FIG. 4 is an enlarged side view of the inside sidewall of the mandrel connector of the system of FIG. 1, showing a guide slot.
FIG. 5 is a partial vertical sectional view of the system of FIG. 1, with the funnel retracted and with the mandrel connector locked to the mandrel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the subsea well includes an upwardly facing mandrel 11. Mandrel 11 is a tubular member having a plurality of circumferential grooves 13 on its exterior near the upper end. Passages 15 extend through the mandrel 11 for communicating with the well. Normally, a cap (not shown) of some type will be located on top of the mandrel 11 and will be removed when the workover operation is beginning. A small cylindrical guide pin 16 is mounted to the sidewall of mandrel 11 and protrudes laterally outward.
A cone seal manifold 17 is mounted to the exterior of mandrel 11 below guide pin 16. Manifold 17 is an annular member with an upward and outward facing conical exterior. Manifold 17 has a plurality of passages 19 extending through it and spaced around its circumference. Each passage 19 contains a check valve 21. The passages 19 lead to lines (not shown) which lead to various other equipment, such as control valves, on the subsea well. A cone seal manifold 17 of this type is described in more detail in U.S. Pat. No. 4,754,813, issued July 19, 1988, Charles E. Jennings.
A guide frame 23 is mounted to the mandrel 11. Guide frame 23 comprises a flat annular plate that extends outward from the mandrel 11 a considerable distance. Gussets 25 are spaced around the bottom of the guide frame 23 to provide support. The outer edge 27 of the guide frame 23 is circular and is beveled on its upper surface 27a and lower surface 27b. The inclination of the upper surface 27a and the lower surface 27b is 45 degrees. This results in the surfaces 27a and 27b being 90 degrees relative to each other.
A riser 33 is shown being lowered from a floating vessel (not shown). Riser 33 is made up of sections of conduit. Passages 34 extend through the riser 33 for communication with the passages 15 in the mandrel. A mandrel connector 35 is rigidly mounted to the lower end of the riser 33 by bolts 36. The mandrel connector 35 has a top or upper plate 37 which is adapted to land on the top of the mandrel 11. A cylindrical inner sidewall 39 extends downward from the top 37. The inner diameter of the inner sidewall 39 is slightly greater than the outer diameter of the mandrel 11, allowing the inner sidewall 39 to slide down over the mandrel 11. A cylindrical outer sidewall 41 is spaced outward from the inner sidewall 39 and depends from the top 37.
A guide slot 40 is formed in the inside surface of the mandrel connector 35. Guide slot 40 extends upward from the lower edge of the inner sidewall 39. As shown in FIG. 4, guide slot 40 has two ramp portions 40a leading to a central cylindrical portion. The ramp portions 40a converge upwardly at a 45 degree angle. This makes the guide slot 40 much wider at the bottom than at the top. Guide slot 40 is adapted to receive the guide pin 16.
A plurality of dogs 43 are carried in windows in the inner sidewall 39. Each dog 43 has grooves on its inner face for engaging the grooves 13. Each dog 43 will move radially between an outward retracted position shown in FIGS. 1 and 3 and an inward locked position shown in FIG. 5.
The dogs 43 are moved inward by means of a cam member 45. Cam member 45 is a ring positioned in the clearance between the inner sidewall 39 and outer sidewall 41. Cam member 45 has an inclined inner face which engages the outer side of each dog 43. A plurality of hydraulic cylinders 47 are mounted to the top 37. The shaft 48 of each hydraulic cylinder 47 is connected to the cam member 45 for raising the cam member to push the dogs 43 inward.
A manifold connector 49 is rigidly mounted to the mandrel connector 35. The manifold connector 49 is a metal block having a conical inner side that faces downward and inward. A plurality of passages 51 extend through the manifold connector 49. The passages 51 are connected to lines (not shown) which lead to the floating vessel for supplying hydraulic fluid. The passages 51 are positioned to align and register with the passages 19 in the cone seal manifold 17.
An upper guide frame or funnel 53 is carried by the mandrel connector 35. Funnel 53 has an upper cylindrical portion 55. The cylindrical portion 55 is closely and slidingly carried on the outside of the mandrel connector outer sidewall 41. A lower frustoconical portion 57 extends downward from the cylindrical portion 55. The conical portion 57 faces downward. Conical portion 57 is considerably larger in diameter than the guide frame 23.
A plurality of hydraulic cylinders 59 are mounted on the upper end of the funnel 53. The shaft 60 of each hydraulic cylinder 59 is connected to a bracket 61. Bracket 61 is secured rigidly to the outer sidewall 41 of the mandrel connector 35. The hydraulic cylinders 59 will move the funnel 53 between an extended position relative to the mandrel connector 35, shown in FIGS. 1 and 3, and a retracted position shown in FIG. 5.
A plurality of rollers 63 are rotatably mounted to the conical portion 57 of funnel 53. The rollers 63 are adapted to extend through holes 65 in the conical portion 57. The rollers 63 are positioned to contact the edge 27 of the guide frame 23. Each roller 63 has a V-shaped rim. An upper surface 63a is adapted to mate with the guide frame upper edge surface 27a. A lower surface 63b is adapted to mate with the guide frame lower edge surface 27b. The surfaces 63a, 63b intersect each other at a 45 degree angle. The rollers 63 allow the funnel 53 to be rotated relative to the guide frame 23. Also, the rollers 63 latch the funnel 53 to the guide frame 23 because of the contact of the lower roller surface 63b with the guide frame edge lower surface 27b. The latching of the rollers prevent upward movement of the funnel 53 relative to the guide frame 23, and allowing tensioning of the riser 33.
Each roller 63 is horizontally mounted to the funnel 53 A plurality of hydraulic cylinders 67, each mounted to a brace 69, serve as means to extend and retract each roller 63. In the retracted position shown in FIG. 1, no portion of any roller 63 protrudes into the interior of funnel 53. In the extended position shown in FIGS. 3 and 5, the rollers 63 extend into the interior of the funnel 53 through the holes 65.
A conical deflector plate 71 is rigidly mounted to the lower edge of the funnel conical portion 57. Deflector plate 71 extends upward and outward. The lower edge 73 joins the lower edge of the funnel conical portion 57. The upper edge 75 is of larger diameter than the lower edge 73. Referring to FIG. 2, the degree of the taper of the deflector plate 71 and the distance between the lower and upper edges 73, 75 is selected to avoid damage to manifold 17. The degree of taper relative to vertical of the deflector plate 71 is about the same as the conical face of the manifold 17.
If the funnel 53 is misaligned while lowering such that the the upper edge 75 would touch the side of mandrel 11, as shown in FIG. 2, the lower edge 73 would touch the guide frame 23. The deflector plate 71 extends over the manifold 17 in that event. No portion of the deflector plate 71 would touch the manifold 17. This provides protection for the manifold 17.
In operation, when the subsea well needs workover operations, the upper protector cap (not shown) will be removed by various means. The riser 33 will be lowered from the vessel (not shown) to a point above the mandrel 11. Because there will be no guide lines to assure precise alignment, the funnel 53 may be considerably out of alignment with the mandrel 11 initially. Current and wave movement make precise alignment difficult. If the funnel 53 accidentally contacts only one side of the guide frame 23, completely missing the mandrel, the deflector plate 71 will avoid damage to the manifold 17. Television cameras located adjacent the funnel 53 will assist in aligning the funnel 53. Prior to lowering the funnel 53 onto the guide frame 27, the riser 33 will be rotated until the funnel 53 is oriented within about 90 degrees of proper orientation, as observed at the surface by the television cameras.
The riser 33 is then lowered. The funnel 53 may contact the upper edge of the mandrel 11 prior to touching the guide frame 23. If so, it will slide laterally and downward as the riser 33 is lowered. The conical portion 57 will touch the upper surface 27a of the guide frame 23 and eventually slide into full engagement as shown in FIG. 3. At this point, the riser 33 is generally coaxial with the mandrel 11.
The hydraulic cylinders 67 are actuated to extend rollers 63. The rollers 63 will contact the edge 27 of the guide frame 23. This latches the funnel 53 to the guide frame 23, but still allows rotation. The funnel 53 will still be in the extended position relative to the mandrel connector 35 as shown in FIG. 3. The mandrel connector 35 will be spaced above the mandrel 11. An upward pull is then executed on the riser 33 to straighten and tension it. The rollers 63 hold the funnel 53 to the guide frame 23 against upward movement The riser 33 will be in tension throughout its length.
Then, while the riser is still under tension, the riser 33 will be rotated for more precise orientation of the mandrel connector 35. The mandrel connector 35 and funnel 53 rotate in unison with the riser 33. The rollers 63 will roll on the edge 27 of the guide frame 23. When close to the proper orientation, the passages 34 in the mandrel connector 35 will be aligned with the passages 15 in the mandrel 11. The passages 51 in the manifold connector 49 will be aligned with the passages 19 in the cone seal manifold 17.
Then, while still holding the riser in tension, the funnel 53 is retracted relative to riser 33. During the retraction movement, funnel 53 does not actually move. Rather, the hydraulic cylinders 59 stroke downward, allowing the riser 33 and mandrel connector 35 to move downward. The hydraulic cylinder 59 will act against the tension hold on the riser, pulling the mandrel connector 35 downward. The guide slot 40 will slide over the guide pin 16, precisely orienting the mandrel connector 35. Some rotation of the funnel 53 may take place due to contact of pin 16 with the ramp portions 40a of the guide slot 40.
The mandrel connector 35 will land on top of the mandrel 11. This causes sealing communication between the passages 34 and 15. At the same time, the manifold connector passages 51 will register with the cone seal manifold passages 19. As shown in FIG. 5, the manifold connector 49 will be in contact with the cone seal manifold 17. The check valve 21 is depressed by the manifold connector 49. This redirects the fluid passages so that hydraulic fluid from the floating vessel will communicate with the controls on the subsea well.
Next, hydraulic fluid pressure is supplied to the hydraulic cylinders 47. This causes the shafts 48 to retract from the position shown in FIG. 3 to that shown in FIG. 5. As they retract, the cam member 45 pushes the dogs 43 inward to tightly engage the grooves 13. This also pulls the manifold connector 49 into tight engagement with the cone seal manifold 17. Workover operations may then take place.
After the workover operations have been completed, the funnel 53 may be removed. Hydraulic pressure is supplied to the hydraulic cylinders 47 to move the cam member 45 downward. This movement frees the dogs 43 to retract. Hydraulic pressure is supplied to the hydraulic cylinders 59 to move the mandrel connector 35 up relative to the funnel 53 and mandrel 11. Hydraulic pressure is supplied to the hydraulic cylinders 67 to retract the rollers 63. The riser 33 and funnel 53 may then be pulled to the surface.
The invention has significant advantages. Utilizing a downward facing funnel on the riser avoids the need for large structural funnels mounted to the subsea wells. The mandrel height is no higher than that required at a normal Christmas tree. Hydraulic controls are made up simulataneously with the locking of the mandrel connector to the mandrel. The retracting rollers provide latching action as well as allowing the funnel to rotate on the guide frame. The latching rollers allow tension to be placed in the riser before the mandrel connector is moved downward around one mandrel. The deflector plate reduces the chance for damage to the cone seal manifold.
While the invention has been shown in only one of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.
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A guidelineless reentry system for a subsea well uses a downward facing funnel. The well has a mandrel surrounded by a guide frame. A funnel and a mandrel connector are carried by the riser. Retracting rollers are mounted to the funnel. Once the riser lands on the guide frame, the rollers are extended to latch the funnel to the guide frame. The funnel is rotated along with the riser to orient the mandrel connector. The mandrel connector is lowered relative to the funnel into engagement with the mandrel.
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BACKGROUND OF THE INVENTION
This invention relates generally to a grease gun adapter suitable for attachment to a conventional grease gun coupler and in particular those grease gun adapters of particular length and shape for special purpose applications, including the adapter fittings thereto.
Hand-operated grease guns, and portable hand-operated grease cannisters are widely used for applying grease in many applications to automotive, farm, aircraft and industrial equipment. In dispensing the grease from such guns, the operator must usually grasp the dispensing barrel with one hand and the dispensing or pressure operating lever with the other. Considerable force must usually be applied to generate the required pressure within the cylinder of the dispensing head to operate the grease dispensing device. As such, the operator does not have a free hand for holding, or directing, the grease applicator conduit, or associated coupler and fitting.
Fittings with sealed lubrication areas such as sealed bearings, sealed universal joints, pillow block bearings and the like are often found. These fittings, however, require lubrication on occasion. Moreover, many hinges, operating levers, and gear or alternately pressure surfaces require lubrication of small amounts of grease. In these instances a standard grease fitting of the ball adapter type is not adequate and is inconvenient to operate.
Dorn, U.S. Pat. No. 3,589,470, and Sundholm, U.S. Pat. No. 3,180,533, have taught two types of needle adapter fittings for grease guns for use in tight or constricted applications. The Dorn device, FIG. 1 of his patent, teaches a special purpose needle extension having a compound two-piece adapter for mating directly onto the alemite-type fitting of a standard grease gun. The ball grease fitting as taught by Dorn has a flange which is intended to abut against the end of the grease gun fitting and be held securely thereto by the tension of the grease gun fitting jaws.
Sundholm teaches a similar needle adapter having a specific adapter body as part of its tip or discharge portion and a connector body with a ball-shaped grease fitting, this connector body having a built-up portion against which the discharge fitting of the grease gun abuts. Sundholm, like Dorn, depends upon the compression jaws of the discharge fitting of the grease gun to securely hold his adapter to the grease gun fitting.
Both Dorn and Sundholm teach relatively short adapter needles. This being the case, the connection between the grease gun discharge fitting and the adapter body is normally held by the operator in directing the very short needle.
In situations, however, where an extended needle adapter or an adapter of unusual shape is required, including an adapter having a number of bends, the operator is not able to grasp the adapter at the grease gun fitting while directing the operation of the adapter and thereby is not able to support that coupling. Very often the operator must grasp the extension needle or rod close to the discharge end thereof. In instances where this must be done, the usual stress applied to the flexible grease hose tends to stress the coupling of the adapter to the grease gun discharge fitting. In instances where the grease gun discharge fitting jaws are worn or have reduced spring tension, or the ball of the grease fitting is worn or undersized, the coupling very often breaks, causing a disruption in the greasing operation, and very often, the loss of grease, or more importantly, a contamination of the grease couplings or grease fitting with dirt.
Adapters as taught by Dorn and Sundholm also have a substantial amount of hardware or fittings dedicated to each needle portion.
What is desired, therefore, is a grease gun extension assembly which provides for a rigidity at the coupling point with the grease gun discharge fitting, which resists the premature uncoupling at this location. What is also desired is a grease gun extension assembly capable of many and varied extension rod configurations, with a minimum of dedication of hardware to each specific extension rod configuration, thereby providing a commonality of parts and reduction in cost in manufacture.
An object of the present invention is to provide a grease gun extension assembly, or a collection of extension assemblies having a commonality of component parts.
A second object of this invention is to provide such collection of extension assemblies with individually dedicated grease flow extension rods and a commonality of components for coupling each individual rod to an alemite-type grease fitting.
Another object of this invention is to provide such commonality of components with the capability of lockably rigidifying the connection at the alemite-type grease fitting.
A further object of this invention is to provide each of such individually dedicated grease flow extension rods with a constricted end for a fine bead grease flow ejection.
SUMMARY OF THE INVENTION
The objectives of this invention are realized by a grease gun assembly for coupling to the alemite fitting typically found on the discharge end of a grease gun. This assembly includes a ball-type grease fitting mounted on one side of a body portion being an extension cylindrical pipe or nipple, this side of the pipe nipple having an annular shoulder on which an interlocking member resides.
A mechanical support tubular sleeve is selectively slidably positionable along the extension nipple for sliding over and about the interlockment of the alemite fitting and ball fitting in retained position with the interlocking member.
Any of variously shaped rigid extension tubes includes a pressure responsive sealing member and a mating cap nut for holding this sealing member and extension tube to the other end of the extension pipe nipple.
DESCRIPTION OF THE DRAWINGS
The advantages, structural features and operation of the subject invention can easily be understood from a reading of the detailed description which follows, in conjunction with the accompanying drawings in which like numerals refer to like elements, and in which:
FIG. 1 shows a partial cutaway view of an assembled grease gun extension assembly.
FIG. 2 shows a cross sectional view of the assembly of FIG. 1 through the compression cap area.
FIG. 3 shows a cross sectional view of the grease discharge tip of the assembly of FIG. 1.
FIG. 4 shows any of the various shaped extension tubes with compression rings which may be assembled as the grease gun extension.
DETAILED DESCRIPTION OF THE INVENTION
A grease gun extension assembly for coupling to the alemite-type fitting typically found on the discharge end of a grease gun is shown in FIG. 1. This assembly 10 has a ball-type grease fitting 11 commonly available in the marketplace. This ball fitting 11, FIG. 1, includes a hexagon-shaped wrenching surface 13 and a threaded portion extending therefrom (not shown in the drawing).
The ball fitting 11 threads mate with threads on the interior bore of an extension nipple 15. This extension nipple can be of any suitable dimensions and is typically about 2 inches long and has an outside diameter of about 1/2 inch. The end of the nipple 15 opposite the ball fitting 11 has male threads cut in the exterior cylindrical surface.
An annular cylindrical shoulder 19 extends about the exterior of the cylindrical nipple 15 at the ball fitting 11 end thereof. This cylindrical shoulder 19 has an annular groove 21 extending in its outer surface at about mid-girth. Positioned in this annular groove 21 is a split compression ring 23. While the cylindrical shoulder 19 can be of many widths, a 1/2 inch width is adequate.
Situated about the ball fitting 11, cylindrical shoulder 19 and split compression ring 23 is a cylindrical sleeve 25. The cylindrical sleeve is mounted over the nipple 15 from the thread 17 portion thereof to have an open end extending beyond the ball fitting 11. The end of the sleeve 25 from its open end is closed except for a round opening 27 therethrough concentric about the longitudinal centerline of the sleeve. This round opening 27 is of slightly larger dimension than the outside diameter of the nipple 15 (about 1/2 inch, plus).
A tapered annular depression 29 extends about the interior surface of the sleeve 25 at the closed end having the opening 27. The taper on this depression 29 extends toward the opposite or open end of the sleeve.
The sleeve 25 inside diameter (about 5/8 inch) is slightly larger than the outside diameter (about 9/16 inch) of the cylindrical shoulder 19 of the nipple 15. The length of this sleeve 25 is approximately equal to the distance from the bottom of the male threads 17 to the outside face of the cylindrical shoulder 19 (about 11/2 inches). The outside diameter of the cylindrical shoulder 19 is approximately the same dimension as the outside diameter of an alemite coupling 31 of the grease gun, to which the extension assembly is coupled via the ball fitting 11 (about 9/16 inch).
With the alemite fitting 31 uncoupled, the sleeve 25 is slidably positioned with its open end approximately adjacent to the end face of the cylindrical shoulder 19. Once the alemite fitting 31 and the ball fitting 11 are coupled, the sleeve 25 is slid to embrace the cylindrical shoulder 19, split compression ring 23, and alemite fitting 31, securing this coupling from lateral movement. The compression ring 23 expands into the tapered depression 29 interlockably holding the sleeve over the mated couplings 11, 31 at a position with its closed end abutting the inner face of the cylindrical shoulder 19.
The threaded end 17 of the nipple 15 is mated to any of a plurality of various shaped extension tubes 33 by the threaded engagement of a cap nut 35.
Cap nut 35 has a hexagon-shaped wrenching outer surface and is easily purchased or manufactured in the industry as a standard assembly item. The cap nut 35 has female threads 37 for mating with the male threads 17 of the nipple 15. The base 39 of the cap nut 35 has a tapered inner surface and a round hole therethrough of a size slightly larger than the outside diameter of the round extension tube 33. Positioned about the end of the extension tube 33, which is parted-off square for mating with the parted-off square end of the nipple 15 threaded end, is a compression ring 41. This compression ring 41 has an inside diameter approximately equal to the outside diameter of the extension tube 33 (about 1/4 inch), and has a rounded outside surface which is acted upon by the tapered end 39 of the cap nut 35. When the cap nut 35 is screwably assembled onto the threads 17 of the nipple 15, the mating end of the extension tube 33 is aligned with the nipple 15 and held tightly against the end thereof. As the cap nut 35 is tightened down on the threads 17 of the nipple 15, the compression ring 39 is deformed, forming a tight pressure seal between the extension tube 33, the cap nut 35, and the threaded end of the nipple 15.
The extension tube 33 has a first larger outside diameter section 33a (about 1/4 inch), which mates with the cap nut 35 and nipple 15, and a smaller outside diameter portion 33b extending therefrom, the smaller outside diameter portion 33b (about 1/8 inch) intended for the particular use of application for the extension assembly. The extension tube 33 includes a tapered shoulder 33c, which forms the transformation from the larger to smaller diameter portions, 33a, 33b, respectively.
The smaller diameter portion 33b of the extension tube 33 may have any of a number of different shapes as shown in FIGS. 1 and 4. The application tip, FIG. 3, has a first ground tapered surface 43, the end of which has been mechanically worked and compressed to a different second taper 45. This compression of the end 45 provides a constricted section of the bore at the tip 45.
While the inside diameter of the assembly may vary from component to component, it is desirable to have approximately the same inside diameter throughout the assembly. Typically, the inside diameter of the nipple 15 is larger than the inside diameter of the extension tube 33. The compressed tip 45, however, provides a constricted bore 47, which has a fixed relation to the opening in the ball fitting 11.
FIG. 4 shows any of various shaped extension tubes 33, each with their own individual compression ring 41, which may be used as part of the grease gun extension assembly, the other components of the assembly being common elements for use with any of the various shaped extension tubes 33.
The components of the assembly 10 may be made from any of varied materials from plastic to fiberglass to copper, brass or steel. Typically, however, these components are made out of a chrome steel, the exception being the compression ring 41, which is typically constructed of brass. A certain amount of rigidity and strength is required of all the steel components. However, they may be made of low carbon steel. An exception to this is the compression ring 23, which is made of spring steel.
Many changes can be made in the above-described grease gun extension assembly apparatus without departing from the intent and scope thereof. Therefore, it is intended that all matter contained in the above description and shown in the accompanying drawings be interpreted as illustrative and not be taken in the limiting sense.
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An extension assembly for a grease gun for coupling to the alemite fitting typically found on the discharge end of such a gun includes a body portion having a grease fitting, a mechanical support positionable thereabout and an extension tube providing a predetermined fixed pathway, and being sealably connected to the body, this extension tube being of a length and shape suitable to a particular job and including a formed application tip, whereof said body portion and extension tube provide a contiguous passageway for grease flow from the fitting to tip.
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PRIORITY CLAIMS
[0001] This application is a continuation of U.S. patent application Ser. No. 11/773,611, filed Jul. 5, 2007, entitled “Striking and Open Lamp Regulation for CCFL Controller”; and claims the benefit of priority under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 60/806,714, filed on Jul. 6, 2006 and entitled “Striking and Open Lamp Regulation for CCFL Controller”; U.S. Provisional Application No. 60/849,211, filed on Oct. 4, 2006 and entitled “Compensation for Supply Voltage Variations in a PWM”; and U.S. Provisional Application No. 60/849,254, filed on Oct. 4, 2006 and entitled “PWM Duty Cycle Inverse Adjustment Circuit,” each of which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to inverter controllers for controlling power to fluorescent lamps and more particularly to an inverter controller with reliable lamp ignition and open lamp voltage regulation.
[0004] 2. Description of the Related Art
[0005] Fluorescent lamps are used in a number of applications where light is required but the power required to generate the light is limited. One particular type of fluorescent lamp is a cold cathode fluorescent lamp (CCFL). CCFLs are used for back lighting or edge lighting of liquid crystal displays (LCDs), which are typically used in notebook computers, web browsers, automotive and industrial instrumentations, and entertainment systems. Such fluorescent lamps require a high starting voltage (on the order of 700-1,600 volts) for a short period of time to ionize the gas contained within the lamp tubes for ignition. After the gas in the CCFL is ionized and the CCFL is fired, less voltage is needed to keep the CCFL on.
[0006] A CCFL tube typically contains a gas, such as Argon, Xenon, or the like, along with a small amount of Mercury. After an initial ignition stage and the formation of plasma, current flows through the tube, which results in the generation of ultraviolet light. The ultraviolet light in turn strikes a phosphorescent material coated in the inner wall of the tube, resulting in visible light.
[0007] A power conversion circuit, known as an inverter, is generally used for driving the CCFL. The inverter accepts a direct current (DC) input voltage and provides an alternating current (AC) output voltage to the CCFL. The brightness (or the light intensity) of the CCFL is controlled by controlling the current (i.e., the lamp current) through the CCFL. For example, the lamp current can be amplitude modulated or pulse width modulated to control the brightness of the CCFL.
[0008] One type of inverter includes a resonant circuit. The inverter includes switching transistors in a half bridge topology or a full bridge topology using power metal-oxide-semiconductor-field-effect-transistors (MOSFETs) to provide the DC to AC conversion. Maximum power is provided at the output of the inverter by switching the MOSFETs with driving signals at a resonant frequency. To control the output voltage as well as the current through the lamp, the inverter can change the frequency of the driving signals either towards the resonant frequency or away from the resonant frequency.
SUMMARY OF THE INVENTION
[0009] One aspect of the present invention is an inverter with a closed feedback loop that sequentially controls a duty cycle sweep and a frequency sweep of at least one driving signal for igniting a lamp and regulating an open lamp voltage. In one embodiment, the closed feedback loop includes a detector circuit, a control voltage generator and two voltage converters. The detector circuit monitors an output voltage of the inverter and indicates when the output voltage of the inverter is greater than a predetermined threshold. The control voltage generator generates a control voltage signal that can vary from a first level to a second level at a predefined rate when the inverter enters a strike mode to ignite the lamp. The control voltage generator is coupled to an output of the detector circuit and the control voltage signal stops varying at the predefined rate when the output of the detector circuit indicates that the output voltage of the inverter is greater than the predetermined threshold. One voltage converter generates a first control output in response to a first range of values for the control voltage signal and another voltage converter generates a second control output in response to a second range of values in the control voltage signal. In one embodiment, the first range of values do not overlap with the second range of values for the control voltage signal so that the duty cycle sweep and the frequency sweep of the driving signal do not occur at the same time during an ignition attempt. In another embodiment, the duty cycle sweep and the frequency sweep partially overlap. The duty cycle sweep or the frequency sweep may be terminated to regulate the output voltage of the inverter at a desired open lamp voltage level. In addition, the strike mode ends when the lamp ignites (e.g., when the lamp conducts a current above a predetermined level) or when a time out condition occurs without ignition of the lamp.
[0010] In one embodiment, a method of igniting a lamp (e.g., a fluorescent lamp) includes sequentially controlling a duty cycle sweep and a frequency sweep in a pulse width modulation (PWM) controller to provide an increasing output voltage to the lamp. For example, the method controls both parameters (duty cycle and frequency) in a novel manner for lamp ignition and open lamp voltage regulation. The method allows for seamless operation of ignition and open lamp voltage regulation schemes during a strike mode of the PWM controller.
[0011] The method advantageously provides reliable lamp ignition and open lamp voltage regulation in applications that have variables (e.g., battery voltage, transformer parameters, lamp characteristics, printed circuit board parasitics, etc.) with wide operating ranges. In one embodiment, a lamp is coupled to a secondary winding of a transformer. The lamp strikes when a voltage across the secondary winding (e.g., secondary voltage or lamp voltage) is sufficiently high. In one embodiment, the secondary voltage is dependent on three parameters: duty cycle of signals (e.g., switching signals) coupled to a primary winding of the transformer, frequency of the switching signals, and battery voltage applied to the primary winding.
[0012] The method also provides accurate (or improved) regulation of open lamp voltage (e.g., when lamp is missing during the strike mode). In one embodiment, the ignition scheme works in conjunction with the open lamp voltage regulation scheme. For example, if the lamp is not present or defective during the strike mode, the PWM controller regulates the secondary voltage to prevent damage to the secondary winding. The open lamp voltage regulation scheme advantageously controls (or limits) the secondary voltage to a window (or range) of secondary voltages that are sufficient to ignite a lamp without causing damage to the secondary winding. The open lamp voltage regulation scheme reduces overshoot in the secondary voltage and regulates the secondary voltage over a wide range of variables. For example, the open lamp peak voltage regulation is specified to be within five percent in one embodiment.
[0013] In one embodiment, the invention is used in notebook or laptop computer backlighting applications in which duty cycle and frequency vary over a wide range for lamp ignition and open lamp voltage regulation. The invention also applies to television, automotive and other applications that use backlighting for visual displays. The invention advantageously controls both duty cycle and frequency in a stable closed feedback loop (e.g., with minimal overshoot in the secondary voltage). A combination of duty cycle control and frequency control provides flexibility to generate a secondary voltage sufficient to strike the lamp without exceeding a maximum rating of the secondary winding in applications with different lamps, transformers, printed circuit board layouts, battery voltages, etc. For example, the invention ensures that a striking frequency is not too low or too high, a duty cycle is not too low for relatively lower battery voltages or too high for relatively higher battery voltages, or open lamp voltage does not exceed secondary voltage ratings.
[0014] In one embodiment, a cold cathode fluorescent lamp (CCFL) controller is interfaced to a primary winding of a transformer to control power to a CCFL coupled to a secondary winding of the transformer. The CCFL controller controls a set of switches (e.g., by alternately turning on and off semiconductor switches) to generate an alternating current (AC) signal in the primary winding with a frequency and duty cycle determined by the CCFL controller. In one embodiment, a transformer primary to secondary turns ratio is chosen to increase a voltage across the secondary winding. The secondary winding is part of a high Q, resonant circuit comprising the secondary winding's parasitic inductance along with resistors, capacitors, and other parasitics coupled to the secondary winding.
[0015] The secondary peak voltage is a parameter of interest for lamp ignition and open lamp voltage regulation. The secondary voltage is relatively high (e.g., 1.5 Kilo-volts) to ignite the CCFL. The secondary voltage is dependent on applied battery voltage, duty cycle and frequency. Since the secondary winding is part of the high Q, resonant circuit (or secondary tank circuit) that has steep skirts, the secondary voltage may change rapidly in response to frequency or duty cycle changes near the resonant frequency. The resonant frequency may vary considerably due to different lamp characteristics and printed circuit board parasitics.
[0016] In one embodiment, a square wave switching signal (or driving signal) is used to generate the AC signal in the primary winding. The square wave switching signal is comprised of odd harmonic frequencies with magnitude ratios determined by the square wave switching signal's duty cycle. Energy in each pulse of the square wave switching signal is distributed to the harmonic frequencies. A square wave switching signal with narrow pulses results in a secondary voltage with relatively narrow peaks of high voltage. A square wave switching signal with wider pulses results in a secondary voltage that has a wider, more sinusoidal shape with relatively lower peak amplitudes. There is a diminishing increase in the peak amplitudes of the secondary voltage as the duty cycle (or pulse width) of the square wave switching signal increases further.
[0017] In one embodiment of the invention, a controller changes the duty cycle of a driving signal during a first stage of a strike mode and changes the frequency of the driving signal during a second stage of the strike mode to ignite a CCFL. The adjustment of the duty cycle (e.g., from a minimum to a maximum duty cycle) followed by adjustment of the frequency (e.g., from a lower frequency to a higher frequency), as needed, has many advantages. First, closed loop regulation (e.g., open lamp voltage regulation) is easier to control and compensate since the initial stage of changing (or sweeping) the duty cycle does not change the closed loop gain. Second, loop stability improves by maximizing the secondary voltage at the lower frequency which is achieved by sweeping the duty cycle to a maximum duty cycle before sweeping the frequency. As the frequency increases toward a resonant frequency, the closed loop gain changes rapidly. The closed loop gain does not change dramatically at lower frequencies away from the resonant frequency. Thus, maximizing the secondary voltage at a low frequency provides loop stability which leads to a more stable open lamp voltage regulation. Third, sweeping the duty cycle first is helpful in applications with relatively high battery voltages in which a relatively lower duty cycle is sufficient to strike the CCFL and a relatively high duty cycle may cause the secondary voltage to exceed a specification for a maximum open lamp voltage. Fourth, transformer saturation (in which the primary winding appears as a short circuit) can be avoided by sweeping the duty cycle from the minimum to the maximum duty cycle. This method of duty cycle sweeping allows the CCFL to safely ignite at a relatively lower duty cycle before reaching transformer saturation. Transformer saturation depends on a product of the battery voltage and the driving signal pulse width.
[0018] In another embodiment of the invention, a controller changes the frequency of a driving signal during a first stage of a strike mode and changes the duty cycle of the driving signal during a second stage of the strike mode to ignite a CCFL. The sequence of sweeping the frequency first and then sweeping the duty cycle also has advantages. For example, a transformer is capable of more power transfer at relatively higher frequencies. In some applications using an under-designed transformer, the transformer may saturate when operating at a relatively low frequency and a high duty cycle. Thus, one striking sequence sweeps the driving signal from a relatively low frequency to a relatively high frequency at a relatively low duty cycle first and then, as needed, sweeps the driving signal from the relatively low duty cycle to a relatively high duty cycle at the relatively high frequency. Starting with a low, but fixed, duty cycle driving signal and sweeping the frequency of the driving signal first is a safer way to prevent transformer saturation since higher frequency operation reduces the danger of saturation, especially in applications without feed forward circuits that limit duty cycle as a function of the battery voltage.
[0019] For the purpose of summarizing the invention, certain aspects, advantages and novel features of the invention have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a block diagram of an inverter for powering a fluorescent lamp according to one embodiment of the present invention.
[0021] FIG. 2 is a circuit diagram of one embodiment of a voltage converter shown in FIG. 1 .
[0022] FIG. 3 illustrates various waveforms from a circuit simulation of the inverter.
[0023] FIG. 4 illustrates various waveforms showing open lamp voltage regulation.
[0024] FIG. 5 provides an expanded view of the waveforms shown in FIG. 4 .
DETAILED DESCRIPTION
[0025] Further descriptions of several embodiments of the invention will be described hereinafter with reference to the drawings. FIG. 1 illustrates a circuit block diagram of one embodiment of an inverter for powering a lamp (e.g., a CCFL) 100 . The inverter comprises a closed feedback loop that seamlessly controls ignition of the lamp 100 and provides open lamp voltage regulation during a strike mode of the inverter. In one embodiment, the closed feedback loop comprises a voltage detector circuit 102 , a control voltage generator 104 , a first voltage converter 106 , and a second voltage converter 108 .
[0026] For example, the voltage detector circuit 102 receives a first feedback signal (VSNS) indicative of an output voltage (or a voltage across the lamp 100 ) and generates an output indicating when the output voltage is greater than a predetermined voltage level corresponding to a first reference voltage (VREF 1 ). The control voltage generator 104 generates a control voltage (VC) that can vary at a first predefined rate (e.g., from a first level to a second level) until an output of the voltage detector circuit 102 indicates that the voltage across the lamp is greater than the predetermined voltage level (e.g, when VSNS is greater than VREF 1 ). The voltage detector circuit 102 stops the control voltage generator 104 from varying at the first predefined rate and adjusts the control voltage in response to the first feedback signal so as to regulate the output voltage of the inverter at approximately the predetermined voltage level. For example, the control voltage can be adjusted by being reduced at a second predefined rate when the first feedback signal exceeds the first reference voltage (e.g., a partial discharge of capacitor 120 through resistor 144 ). Thus, if the lamp 100 is not present during the strike mode, the output voltage is regulated at approximately the predetermined voltage level to prevent damage to inverter components (e.g., a high voltage transformer).
[0027] The control voltage is provided to the first voltage converter 106 and the second voltage converter 108 . The first voltage converter 106 responds to a first range of the control voltage to generate a first control output that determines duty cycles of driving signals during the strike mode. The second voltage converter 108 responds to a second range of the control voltage to generate a second control output that determines frequency of the driving signals during the strike mode. For example, the first control output and the second control output are selectively provided to a PWM circuit 110 during the strike mode to generate a PWM signal for controlling power to the lamp 100 . In one embodiment, the PWM circuit 110 is implemented in a common controller integrated circuit 154 with the voltage detector circuit 102 , the control voltage generator 104 , the first voltage converter 106 , and the second voltage converter 108
[0028] In one embodiment, the PWM signal is provided to a bridge driver 112 to generate a plurality of driving signals for controlling respective semiconductor switches in a switching network 114 . The switching network 114 couples a supply voltage (e.g., a substantially DC source voltage or VBAT) in alternating polarity across a primary winding of a transformer 116 to generate a substantially AC voltage across a secondary winding of the transformer 116 . The lamp 100 is coupled to the secondary winding of the transformer 116 .
[0029] In the embodiment shown in FIG. 1 , the switching network 114 is shown as a full-bridge switching networking comprising four transistors M 1 , M 2 , M 3 , M 5 . Other switching network topologies (e.g., half-bridge, push-pull, etc.) are also possible. In one embodiment, the secondary winding of the transformer 116 is coupled to the lamp 100 through a resonant inductor 150 and a DC blocking capacitor 152 . The resonant inductor 150 can be a leakage inductance associated with the secondary winding and not a separate component. The resonant inductor 150 is part of a secondary resonant circuit that also comprises resistors, capacitors, and other parasitics (not shown) coupled to the secondary winding to establish a resonant frequency.
[0030] In one application, the control voltage (VC) has an initial state of zero volts at the beginning of a strike mode and increases at a predefined rate to a preset value (e.g., VDD or a supply voltage). The control voltage can be generated by many methods using different circuit topologies, and FIG. 1 shows one method of generating the control voltage. For example, a peak detector transistor (or NMOS transistor M 0 ) 118 is initially off and a capacitor (C 0 ) 120 is charged through a pull-up resistor 122 to produce the control voltage across the capacitor 120 at an exponential RC rate of change.
[0031] The control voltage is provided to input terminals (or input ports) of the first and second voltage converters 106 , 108 . In one embodiment, the voltage converters 106 , 108 have limited and non-overlapping input ranges. For example, the first voltage converter (or voltage converter # 1 ) 106 has a first limited input range (e.g., from 0-1 volt) while the second voltage converter (or voltage converter # 2 ) 108 has a second limited input range (e.g., from 1-2 volts). The output of each voltage converter changes when the control voltage is within the respective limited input range.
[0032] FIG. 2 is a schematic diagram of one embodiment of a voltage converter. A reference voltage is generated across a first resistor (R 1 ) 200 . For example, the reference voltage is approximately 0.5 volt for the first voltage converter 106 . The value of this reference voltage and a second resistor (R 2 ) 202 can be chosen to determine (or limit) the input range of the voltage converter. The control voltage (VC) from FIG. 1 is provided to an input port (VIN). The reference voltage and the control voltage are level shifted by respective PMOS source followers (M 6 and M 7 ) 215 , 212 . A differential voltage (VDIFF) between an input voltage at the input port (VIN) and the reference voltage is seen across the second resistor (R 2 ) 202 . A current conducted by the second resistor (R 2 ) 202 is added to or subtracted from a current conducted by a transistor M 2 204 . The transistor M 2 204 conducts a current reference derived from a bandgap circuit comprising transistor M 4 214 . A sum of the current reference and the current conducted by the second resistor (R 2 ) 202 is mirrored by a current-mirror circuit 208 comprising transistors M 9 , M 8 , M 5 and M 0 to produce an output voltage (VOUT) across an output resistor (R 0 ) 206 . The current mirror gain and the output resistor (R 0 ) 206 can be used to scale and offset the differential voltage between the input voltage and the reference voltage across the first resistor 200 . Specific details for the output portion of the voltage converter are dependent on circuits that will be coupled to the output voltage.
[0033] In the embodiment shown in FIG. 1 , the outputs from the first voltage converter 106 and the second voltage converter 108 are selectively provided to first and second input terminals of the PWM circuit 110 during the strike mode. In one embodiment, the PWM circuit 110 comprises an oscillator 124 , a PWM comparator 126 and an optional feed-forward circuit 128 . The optional feed-forward circuit 128 , if present, is coupled between the first input terminal of the PWM circuit 110 and a first input terminal of the PWM comparator 126 . The voltage at the first input terminal of the PWM circuit 110 determines the pulse width (or duty cycle) of a PWM signal at an output terminal of the PWM comparator 126 , which is also the output terminal of the PWM circuit 110 . The oscillator 124 generates a sawtooth waveform for a second input terminal of the PWM comparator 126 . The frequency of the sawtooth waveform is determined by the voltage at the second input terminal of the PWM circuit 110 .
[0034] During steady state operations (or run mode), a substantially fixed reference voltage (VREF 3 ) is selectively provided to the second input terminal of the PWM circuit 110 to establish a substantially constant operating frequency for the inverter. During the run mode, the first input terminal of the PWM circuit 110 is selectively coupled to a current feedback loop comprising an error amplifier 130 . For example, the current feedback loop senses current conducted by the lamp 100 and generates a current feedback signal (ISNS) indicative of the lamp current level. In one embodiment, the current feedback signal is a voltage generated across a sensing resistor 132 coupled in series with the lamp 100 . A capacitor 134 is optionally coupled in parallel with the sensing resistor 132 for filtering. The current feedback signal is provided to a full wave rectifier 136 to generate a substantially DC signal for a first input terminal of the error amplifier 130 . A voltage (VREF 2 ) indicative of desired lamp current amplitude is provided to a second input terminal of the error amplifier 130 . In one embodiment, the error amplifier 130 is a transconductance amplifier and a capacitor (C 1 ) 138 is coupled to an output terminal of the error amplifier 130 to generate an error voltage for the first input terminal of the PWM circuit 110 during the run mode. The error voltage is used to adjust the pulse width (or duty cycle) of the PWM signal at the output of the PWM circuit 110 to achieve the desired lamp current amplitude during the run mode.
[0035] In one embodiment, the first voltage converter 106 is configured to transfer a 0-1 volt input voltage into an output voltage that is within a trough and peak of the sawtooth waveform generated by the oscillator 124 . For example, the sawtooth waveform may have a peak-to-peak voltage of 3 volts with a 1 volt trough (or offset) voltage. The output voltage of the first voltage converter 106 is provided as a reference voltage to the first input terminal of the PWM comparator 126 . As the reference voltage at the first input terminal of the PWM comparator 126 changes, the duty cycle of the signal at the output terminal of the PWM comparator 126 changes (e.g., sweeps or changes without significant discontinuity). In the embodiment shown in FIG. 1 , an optional feed-forward circuit 128 is shown between the output of the first voltage converter 106 and the first input terminal of PWM comparator 126 . The optional feed-forward circuit 128 may make additional adjustments to the duty cycle of the signal at the output terminal of the PWM comparator 126 in response to supply voltage variations, as described further below.
[0036] In one embodiment, the second voltage converter 108 is configured to transfer a 1-2 volts input voltage from the control voltage (VC) into an output voltage that is used to sweep the frequency of the oscillator 124 from a starting frequency (e.g., a normal lamp running frequency) to several times (e.g., two times) the starting frequency. Other frequency sweeping ranges are also possible. Since the control voltage ramps starting from zero volt and the input range of the first voltage converter 106 is less than the input range of the second voltage converter 108 , the output voltage of the first voltage converter 106 will vary (or sweep) before the output voltage of the second voltage converter 108 .
[0037] In the embodiment described above, the input ranges for the voltage converters 106 , 108 are chosen such that the output of the PWM comparator 126 sweeps in duty cycle first at a starting frequency and then sweeps in frequency at a predetermined (or maximum) duty cycle. Preferably, the duty cycle and the frequency sweep independently and do not interact simultaneously. In one embodiment, the predetermined duty cycle is limited by a feed-forward circuit that correlates duty cycle with applied battery voltage. For example, the feed-forward circuit adjusts the duty cycle to compensate for variations in the applied battery voltage. Details of some feed-forward circuits are disclosed in co-owned U.S. Provisional Application No. 60/849,211, filed on Oct. 4, 2006 and entitled “Compensation for Supply Voltage Variations in a PWM,” and U.S. Provisional Application No. 60/849,254, filed on Oct. 4, 2006 and entitled “PWM Duty Cycle Inverse Adjustment Circuit,” the disclosure of which is hereby incorporated by reference herein in its entirety.
[0038] In other embodiments, the input ranges of the voltage converters 106 , 108 are chosen (or limited) such that the frequency sweep occurs before the duty cycle sweep. For example, the input voltage ranges for the voltage converters 106 , 108 can be altered as described above with reference to FIG. 2 and the input voltage ranges discussed above can be reversed between the voltage converters 106 , 108 such that the frequency sweep occurs first. The frequency sweep is more effective in striking the lamp 100 with relatively low battery voltages (e.g., about 7 volts) while the duty cycle sweep is more effective at striking the lamp 100 with relatively high battery voltages (e.g., about 20 volts). In yet another embodiment, the input voltage ranges of the voltage converters 106 , 108 overlap to provide an overlap between the duty cycle sweep and the frequency sweep.
[0039] FIG. 3 illustrates a simulation showing a control voltage 300 , a secondary or lamp voltage 302 and a switching signal 304 with respect to time in an application with a 10 volts battery voltage. For example, as the control voltage 300 is ramping from approximately zero volt to approximately two volts, the duty cycles of the lamp voltage 302 and the switching signal 304 sweep first and then their frequencies sweep at a maximum duty cycle. The change from duty cycle sweep to frequency sweep is marked with a lined denoted “A.” In a normal application, the control voltage 300 stops ramping and the sweeping stops when the lamp voltage 302 is sufficiently high to strike a lamp or exceeds a predetermined open lamp voltage corresponding to VREF 1 in FIG. 1 . In the simulation shown in FIG. 3 , the control voltage is allowed to continue ramping to show how continued sweeping affects the lamp voltage 302 . For example, the lamp voltage 302 increases with time initially due to increasing duty cycle of the switching signal 304 until a time marked by line A. Thereafter, the lamp voltage 302 continues to increase with time due to increasing frequency of the switching signal 304 until the frequency exceeds a resonant frequency associated with a secondary resonant tank circuit. The lamp voltage 302 begins to decrease when the frequency increases beyond the resonant frequency because the voltage gain of the secondary resonant tank circuit decreases as the frequency moves away from the resonant frequency.
[0040] Referring to FIG. 1 , one embodiment of the voltage detector circuit 102 used to regulate open lamp voltage during the strike mode comprises a full wave rectifier 140 , a comparator 142 , the transistor M 0 (e.g., NMOS) 118 and a resistor R 0 144 . A capacitor divider circuit comprising a capacitor C 6 146 and a capacitor C 11 148 is used to monitor a transformer secondary voltage and to generate a sensed voltage (e.g., the first feedback signal or VSNS) that is provided to an input terminal of the full wave rectifier 140 . The comparator 142 compares an output of the full wave rectifier 140 with a reference VREF 1 . If the output of the full wave rectifier 140 (e.g., output peak voltage) exceeds the reference VREF 1 (such as during an open lamp condition), the comparator will turn on the transistor M 0 118 to adjust the control voltage such that the transformer secondary voltage is maintained (or regulated) at a predetermined open lamp voltage level (or amplitude). Thus, a combination of the transistor M 0 118 , the capacitor C 0 120 , the resistor R 0 144 and the pull-up resistor 122 forms a peak detector circuit. In one embodiment, a ratio between the resistor R 0 144 and the pull-up resistor 122 is chosen such that the capacitor C 0 120 has a faster discharging rate and a slower charging rate.
[0041] A closed feedback loop is formed since an output of the voltage detector circuit 102 is coupled to the control voltage that regulates ignition. The closed feedback loop regulates the transformer secondary voltage by adjusting the control voltage until the output of the full wave rectifier 140 is approximately equal to the reference voltage VREF 1 . FIG. 4 illustrates one example of the transformer secondary voltage (or open lamp voltage, e.g., voltage across the secondary winding of the transformer 116 ) as a function of time shown as waveform 502 in relationship to the control voltage as a function of time shown as waveform 504 and one of the driving signals applied to a semiconductor switch in the switching network 114 as a function of time shown as waveform 500 . FIG. 5 illustrates in more detail a portion of FIG. 4 that confirms excellent regulation of the open lamp voltage. For example, at approximately time T 1 , the transformer secondary voltage reaches a predetermined level and the control voltage levels off (or stops increasing) to maintain the transformer secondary voltage at approximately the predetermined level.
[0042] In one embodiment, two single-pole-double-throw (SPDT) switches are used to toggle (or select) between strike and run modes in FIG. 1 . For example, ignition of the lamp 100 can be detected to toggle from the strike mode to the run mode. In one embodiment, ignition is determined by monitoring when the current feedback signal (ISNS) exceeds a threshold. In the embodiment shown in FIG. 1 , the output of the full wave rectifier 136 can be compared to the threshold voltage VREF 2 or a separate voltage reference to determine ignition of the lamp 100 . When the lamp 100 is considered lit, the SPDT switches toggle and latch to run mode positions. In the run mode positions, the oscillator 124 is coupled to a reference voltage VREF 3 that sets the oscillator's frequency to a run mode frequency (e.g., the starting or the lowest strike mode frequency). An input of an optional feed forward circuit 128 is coupled to the output of the error amplifier 130 that regulates the lamp current amplitude once the lamp 100 is lit.
[0043] While certain embodiments of the invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
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An apparatus and method for igniting a lamp during a strike mode of an inverter comprising: sequentially controlling a duty cycle sweep and a frequency sweep of driving signals in the inverter to provide an increasing output voltage to the lamp. One embodiment advantageously includes a closed feedback loop to implement the duty cycle sweep and the frequency sweep such that an open lamp voltage is reliably regulated during the strike mode. For example, the closed feedback loop stops the duty cycle sweep or the frequency sweep when the output voltage to the lamp reaches a predetermined threshold and makes adjustments to the duty cycle or frequency the driving signals as needed to keep the output voltage at approximately the predetermined threshold if the lamp has not ignited.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method for non-destructive temporary marking of zirconium, hafnium, and titanium.
2. The Prior Art
In manufacturing processes, it is often desirable to monitor the location and status of parts. To simplify such monitoring, parts are often marked in some manner. The prior art includes marking systems of three basic types, each of which may have advantages in a particular application. Marking systems requiring mechanical removal of material from the part or substantial disturbance of the material surface are well known. Such methods include engraving, stamping, scribing, and vibratory upsetting. In other applications burning or melting of a portion of the metal, which results in a discernable mark resulting from the altered surface texture, may be employed.
The foregoing methods frequently provide an adequate marking system. Each method provides a clearly discernable mark. Each method also, however, creates an altered metallurgical condition involving a dimensional change, which may be significant and adverse in some applications.
Alternatively, staining, painting or the like may be used to mark items. Use of stencils and painting, for example, provides an inexpensive, flexible, and thoroughly adequate marking system for many applications. Staining, painting, and the like however, contaminate the marked surface.
In some applications the dimensional change or contamination caused by one or more of the marking systems discussed above is unacceptable. For example, in some applications, during construction of military or other aircraft engines it is sometimes desirable to mark parts with identifying numbers and other information without disturbing the surface of the metal. Precision superficial marking without disturbing the metallurgical condition of the metal is also sometimes desirable in the nuclear energy industry. None of the marking systems described above meets these critical requirements.
Applications in the nuclear power industry, and in high performance aircraft, make extensive use of zirconium, alloys of zirconium, titanium, alloys of titanium; hafnium and alloys of hafnium.
Therefore, a need exists for a non-destructive superficial marking system that will not significantly disturb the surface or metallurgical characteristics of a metal workpiece comprising zirconium, titanium or hafnium.
SUMMARY OF THE INVENTION
An exemplary embodiment of the invention will be described in connection with the preferred embodiment involving a laser marking system. It is, however, to be understood that the invention may be expressed in a variety of physical embodiments. The present invention provides a method of marking a metallic element of the fourth group of elements in the periodic table comprising the sequential steps of oxidizing the surface of said metallic element and heating the surface of said anodized metallic element locally to produce a mark. In a preferred embodiment, an oxide layer is produced by anodizing and the local heating to produce a mark is produced by a laser. The method of the invention provides a superficial non-destructive method of marking zirconium, titanium, or hafnium, and alloys based on one or more of these foregoing metals and other metals. The method of the present invention relies on the ability of these three metals to absorb oxygen, and the constrasting color between the metal and its oxide.
Accordingly, it is an object of the present invention to provide a novel method for marking metals in the fourth family of the periodic chart, and alloys based on one or more of them.
It is another object of the present invention to provide such a marking method that does not significantly alter the metallurgical characteristics of the base metal.
It is a further object of the invention to provide such a marking system that in non-destructive and superficial.
It is another object of the present invention to provide such a marking system that provides a mark whose color constrasts with the color of the background surrounding it.
Other objects and many attendant advantages of the invention will become more apparent upon the reading of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a block drawing of the metal or metal alloy to be marked.
FIG. 2 illustrates the process by which the marking is made with the use of a laser.
FIG. 3 illustrates the metal or metal alloy after the color contrast marking is completed.
DETAILED DESCRIPTION OF THE INVENTION
To practice the method, a metal 10 illustrated in FIG. 1 comprising zirconium, hafnium, or titanium is oxidized according to any known process. An especially useful technique for oxidizing the metal 10 is anodizing. Anodizing produces a very thin oxide coating 12 on the metal 10. The oxide coating 12 has a color that contrasts with the color of the metal 10. A full spectrum of colors can be achieved when anodizing zirconium by varying the voltage. Deep blue is especially useful because of its high contrast with the substantially white zirconium alloy. The oxide of zirconium produced by anodizing consists of ZrO 2 .
When heated to a temperature of approximately 1300° F. (705° C.) zirconium oxide is reduced to zirconium and oxygen. In the case of other metals, similar chemical reactions take place. The metal previously bound in the oxygen retains its physical position and characteristics. This anodized oxide layer 12 is approximately 5×10 -6 inches thick. The oxide film 12 affects the surface characteristics of the metal 10, e.g., it alters electrical contact resistance of the metal 10. It can also be used as a protective coating on, e.g., zirconium clad nuclear reactor fuel rods. These surface effects have no adverse effect in most applications. When the oxide coating 12 is reduced by heating the oxygen is driven from the oxide coating 12, and goes into solid solution within the zirconium. This process of producing an oxide layer 12 then reducing the oxide and driving the oxygen into solid solution does not significantly alter dimensional characteristics of the metal 10.
Locally heating the oxide layer 12 results in a discernable mark 14 caused by the color contrast between the oxide coating 12 and the metal 10 as illustrated in FIG. 3. Any suitable means of local heating may be employed, such as an electron beam, X-ray beam, or a heated tip similar to a soldering iron and so forth. In a preferred embodiment, a laser 16 as illustrated in FIG. 2 provides the required heat. Using a laser 16, lines approximately 3/4 of an inch long and 0.010 inches wide were produced in a preliminary evaluation using Zircaloy-4 which had been anodically filmed. A laser of approximately 5 watts output was used in tests.
A variety of subsequent examination procedures disclosed no observable damage to the metal 10. Best results were obtained with a continuous output laser, which leaves a clearer mark than a pulsed laser. Pulsed lasers operating at frequencies of 3,000 and 10,000 hertz were also used. These caused some microscopic local melting resulting in a scalloped mark.
Marked specimens were subjected to visual examination, optical microscopic examination, and scanning electron microscopy. Each of these tests indicated no significant damage to or alteration in the metallurgical structure of the specimen. The demarcation line between the annealed edge and the anodic film is readily observed by scanning electron microscopy. Removal of the oxide film does not visibly alter the grain structure of the metal as seen by the scanning electron microscope.
Samples of marked zircaloy-4 were subjected to corrosion testing following marking. The corrosion testing comprised vacuum annealing the sample for four hours at 1,200° F. Sample was then pickled in 35% HNO 3 , 3% HF to remove 0.002 inches per surface. The test sample was then rinsed in 180° F. deionized water and subsequently corrosion tested in hot water for three days at 680° F. Visual examination after testing showed both the area of the laser line and the previously anodized area to have acceptable black lusterous oxide film. The original mark could be detected after corrosion testing only with great difficulty. It is believed that the marked area may have originally pickled faster because of less oxide presence. This test shows that the process according to the present invention has no adverse effect on subsequent corrosion of the metal in a typical corrosive environment.
To test for the possibility that the process of the present invention may sensitize the metal to abnormal grain growth, a specimen was subjected to three annealing cyles of four hours at 1,200° F. and then metallographically evaluated. No microstructural difference could be detected between the area of the mark and the surrounding metal.
Finally, transverse sections of the samples were examined. Three transverse sections were further tested under electron microscopy. The three samples were (1) the sample as marked; (2) as corrosion tested; and (3 ) as annealed for blocky alpha study. In each case, no difference in microstructure could be detected between the material adjacent to the line and the base metal. No dimensional evidence of the markings could be detected.
Any desired marking may be made according to the present invention. The ease of marking straight lines according to the present invention suggests that machine readable bar codes such as those found on grocery store food items would present a useful marking system. In any application it may be useful to control the movment and off-on state of the laser with a computer. Normal human readable characters such as letters and numerals could also provide useful marking according to the present invention. In fact, any communicating mark may be used.
Such marks will only be temporary if the workpiece is ultimately exposed to high temperatures because high temperatures will reoxidize the marks. The marking system of the present invention is, therefore, most useful in applications where the workpiece is not exposed to high temperatures or corrosive environments, or to applications where the workpiece must be monitored only during the manufacturing process.
Although the invention has been described with respect to a preferred embodiment, variations will occur to those skilled in the art. For example, an oxide film was used in the preferred embodiment. An equivalent solid state reaction could be used on a surface hydride, nitride, or carbide, as long as the oxide and the base metal contrast in color. Further, in the preferred embodiment described above, the contrasting appearance between the metal and its oxide is in the visible spectrum. A similar contrasting appearance between the oxide and the substrate could also be found in different portions of the spectrum, such as infrared, ultraviolet, or X-ray fluorescents. Therefore, it is intended that the invention not be limited to the specific embodiment illustrated but should be interpreted according to the claims that follow.
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A marking system for providing a superficial metallurgically immaterial mark on zirconium, its alloys, and other metals is disclosed. The method includes producing a thin oxide layer on the surface of the metal, and locally heating a portion of the oxide layer to reduce it to the base metal and oxygen, which is driven into solid solution, thereby leaving a mark of contrasting color.
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RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 08/948,930 filed on Oct. 10, 1997 now U.S. Pat. No. 5,982,844 in the names of Andrew P. Tybinkowski, Michael J. Duffy and Gilbert W. McKenna, and assigned to the present assignee.
In addition the application is related to the following U.S. applications filed on Oct. 10, 1997 and commonly assigned with the present application, the contents of which are incorporated herein in their entirety by reference:
U.S. application Ser. No. 08/948,937, “Air Calibration Scan for Computed Tomography Scanner with Obstructing Objects,” invented by David A. Schafer, et al.,
U.S. application Ser. No. 08/948,928, “Computed Tomography Scanning Apparatus and Method With Temperature Compensation for Dark Current Offsets,” invented by Christopher C. Ruth, et al.,
U.S. Pat. No. 5,909,477, “Computed Tomography Scanning Target Detection Using Non-Parallel Slices,” invented by Christopher C. Ruth, et al.,
U.S. Pat. No. 5,901,198, “Computed Tomography Scanning Target Detection Using Target Surface Normals,” invented by Christopher C. Ruth, et al.,
U.S. Pat. No. 5,887,047, “Parallel Processing Architecture for Computed Tomography Scanning System Using Non-Parallel Slices,” invented by Christopher C. Ruth, et al.,
U.S. Pat. No. 5,881,122, “Computed Tomography Scanning Apparatus and Method Generating Parallel Projections Using Non-Parallel Slices,” invented by Christopher C. Ruth, et al.,
U.S. application Ser. No. 08/949,127, “Computed Tomography Scanning Apparatus and Method Using Adaptive Reconstruction Window,” invented by Bernard M. Gordon, et al.,
U.S. application Ser. No. 08/948,450, “Area Detector Array for Computed Tomography Scanning System,” invented by David A. Schafer, et al.,
U.S. application Ser. No. 08/948,692, “Closed Loop Air Conditioning System for a Computed Tomography Scanner,” invented by Eric Bailey, et al.,
U.S. application Ser. No. 08/948,493, “Measurement and Control System for Controlling System Functions as a Function of Rotational Parameters of a Rotating Device,” invented by Geoffrey A. Legg, et al.,
U.S. application Ser. No. 08/948,698, “Rotary Energy Shield for Computed Tomography Scanner,” invented by Andrew P. Tybinkowski, et al.,
BACKGROUND OF THE INVENTION
In modern third generation computed tomography (CT) scanners, an X-ray source and detector array are secured on opposite sides of the central opening of an annular disk. The disk is mounted to a gantry support for rotation about a subject or object (positioned in the opening) to be scanned. During a scan, the source and detectors image the object disposed within the machine at incremental scan angles. In fourth generation CT scanners the detectors are fixed relative to the object or subject being scanned, and only the source is mounted on the rotating disk for rotation about the subject or object. In both types of systems a process referred to as reconstruction generates a series of two-dimensional images or slices of the object from the captured data.
For “fixed z-axis” scans (the “z-axis” being the axis of rotation of the disk), the disk and its components rotate about a stationary object or subject with the disk fixed at a specific Z-axis location. For “helical” scans, translational movement along the Z-axis is simultaneous provided between the object or subject and the rotating disk. In both fixed and translational scanning systems, precision in the angular velocity, or rotation rate, of the gantry disk is essential for minimization of reconstruction errors.
Timing belts, or cog belts, have been employed in the past to effect a high degree of precision in rotation rate. A standard timing belt is driven by a motor mounted to the stationary frame. Periodic lateral grooves transverse to the major axis of the belt mesh with teeth on a drive sprocket at the motor and a large driven sprocket mounted to the gantry disk. The driven sprocket must be large enough to avoid interference with the central aperture of the gantry and thus allow room for a object to pass therethrough. For this reason, extraordinarily-large timing belts are required in these systems.
A typical prior art scanner requires at least a six meter timing belt. Timing belts of such a large magnitude are very expensive, as they are difficult to manufacture and often must be custom built, and/or purchased in large quantities. Furthermore, the large driven sprockets are specialized and are therefore expensive, available at a cost of $4,000 to $6,000, depending on the diameter. Alignment between the drive sprocket and driven sprocket must be accurate to a high degree of precision, to avoid lateral walking of the belt relative to the sprockets. Timing belts tend to wear rapidly, and therefore must be replaced frequently, for example once per year for a medical scanner. Replacement is an involved procedure, requiring removal of the scanner system from operation for an extended period of time; perhaps a couple of days. This is due to the fact that in prior art configurations, the driven sprocket is positioned between the annular gantry and the fixed frame. Access to the timing belt for its removal and replacement therefore requires complete removal of the gantry from the frame. Positioning of the sprocket on the component side of the gantry is impractical, since the timing belt would interfere with the rotating gantry components.
A further disadvantage of timing belts in CT systems is their tendency to modulate the rotational speed of the gantry at the frequency of their teeth or cogs. The modulation causes artifacts in the resulting images which must be resolved or otherwise corrected by the image processing system.
In addition, mounting the disk for rotational movement requires some type of reliable support so that the disk reliably rotates with little or no lateral movement in the plane of rotation. In the typical prior art system, standard bearing arrangements, with highly machined races and balls, are expensive. Because of the weight and size of the disk the bearings tend to wear, and are difficult to replace. One solution to this problem has been to mount the disk for centerless rotation on rollers such as shown in U.S. Pat. No. 5,473,657 issued Dec. 5, 1995 in the name of Gilbert W. McKenna, and assigned to the present assignee.
SUMMARY OF THE INVENTION
The present invention is directed to a CT scanner drive assembly that mitigates and/or eliminates the shortcomings associated with prior art scanner drive assemblies described above. The apparatus of the invention comprises an annulus, preferably in the form of a disk, which is sheaved about its perimeter such that the annulus is operable as a driven pulley rotatable about an object to be scanned. Electronic components are preferably mounted to the annulus for performing a tomographic scan of the object. A motor includes a similarly sheaved drive pulley. A belt tensioned between the drive pulley of the motor and the driven pulley of the annulus transfers rotational motion of the motor to the annulus for driving the annulus rotationally about the object during a scan.
In a preferred embodiment, the belt comprises a V-belt or poly-V-belt. An adjustable tensioner draws the motor drive pulley toward or away from the annulus for adjusting the tension of the belt. The annulus preferably comprises a disk having first and second faces. By spacing the disk from the frame, components may be mounted on both faces of the disk, or through apertures in the disk, mitigating space limitations for mounting components to the disk, and balancing the disk center of mass near the disk plane.
In one preferred embodiment, a disk bearing is preferably located at or near the disk center of mass, and mounted to spacers rigidly coupled to the system frame. This configuration reduces the moment arm between the bearing and disk center of mass, improving the life of the bearing and allowing for use of less expensive, simpler bearings, for example Franke four-wire bearings of the type described in U.S. Pat. No. 5,071,264, incorporated herein by reference.
In another preferred embodiment, the annulus is mounted for rotation within the gantry frame wherein opposing grooves are formed in the periphery of the annulus and the inner periphery of the opening of the gantry frame, and are shaped to receive less expensive, simpler bearings, for example Franke four-wire bearings of the type described in U.S. Pat. No. 5,071,264. In one preferred embodiment, the bearing system includes a single set of wire races and spherical bearings disposed therebetween. The spherical bearings are all centered in the center plane of the disk. In another preferred embodiment, the bearing system includes a pair of sets of wire races and spherical bearings disposed therebetween. The spherical bearings of the two sets are respectively disposed in parallel planes, preferably on opposite sides of and equally spaced from the center plane of the disk.
In this manner, the present invention provides a simple and effective technique for driving the annulus about the object or subject to be scanned. The V-belts provide accurate timing—as they minimize slippage, and maximize efficient energy transfer. Further, V-belts offer the additional benefit of a long life time, on the order of five years, before replacement is necessary. Large V-belts are currently available commercially at a relatively low cost of approximately $100.
This configuration is well adapted for continuous operation in an airport setting for baggage scanning applications and systems of the type that use CT scanners and which run continuously for 18-20 hours daily. By conveniently locating the belt on an outer edge of the annulus or disk, maintenance of the belt is relatively straightforward and can be performed expeditiously, on the order of 1-2 hours, without the need for disassembling the entire gantry as in the prior art. In addition, V-belts are generally relatively flexible and can be mounted without the need for critical alignment tolerances of prior art timing belts. The flexibility of the V-belt, in combination with its longitudinal grooves provide a smooth interface for driving the disk in continuous motion, without modulating the rotational speed. The drive system therefore makes no contribution to image artifacts.
In addition, the use of the simpler bearings allows for easier servicing of the scanner.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
FIG. 1 is a perspective view of an outer console of a baggage scanner system of the type using a CT scanner constructed in accordance with the present invention.
FIG. 2 is a front perspective view of a scanner frame and gantry disk configuration in accordance with the present invention.
FIG. 3 is a rear perspective view of the frame and gantry disk configuration of FIG. 2 in accordance with the present invention.
FIG. 4 is a side cross-sectional view of a portion of the gantry and frame of FIGS. 2 and 3, illustrating the sheaved outer edge of the gantry disk and a preferred bearing configuration in accordance with the present invention.
FIG. 5 is a close-up cut-away side view of one preferred embodiment of the improved bearing configuration of the present invention.
FIGS. 6A and 6B are exploded perspective views of alternative embodiments of the motor and drive pulley tensioner apparatus in accordance with the present invention.
FIG. 7 is a close-up perspective view of the interface between the V-belt and the sheaved outer perimeter of the gantry disk in accordance with the present invention.
FIG. 8A is a side cross-sectional view of a portion of the annulus and gantry frame of another preferred embodiment of the improved bearing configuration of the present invention.
FIG. 8B is a close-up cut-away view of the improved bearing configuration of FIG. 8 A.
FIG. 9A is a side cross-sectional view of a portion of the annulus and gantry frame of a third preferred embodiment of the improved bearing configuration of the present invention.
FIG. 9B is a close-up cut-away view of the improved bearing configuration of FIG. 9 A.
FIG. 10 is a perspective view of a disk lock in accordance with the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 is a perspective illustration of outer console 100 of a baggage scanning system of the type using an X-ray computed tomography (CT) scanner. The console 100 comprises a plurality of panels 104 mounted to a rigid frame (see FIGS. 2 and 3) erected on a base 33 . The panels 104 are hinged to the frame or are otherwise removable to provide access to the inner components of the scanner. A conveyor 102 transports objects to be scanned, for example, airport baggage, into the scanning area. As is well known, where the CT scanner is employed as a medical scanner, a suitable patient table usually supports a patient within the CT scanner so that a select portion of the patient can be scanned.
FIG. 2 is a front perspective view of the primary components of a CT scanner in accordance with the present invention. A rigid vertical frame 32 is erected on a base 33 . The base 33 includes a plurality of height-adjustable feet 34 for leveling the system.
An annulus or disk 30 preferably formed of a light-weight, rigid material such as aluminum, magnesium-aluminum alloy or the like is rotatably mounted on the frame 32 . The annulus 30 may be solid or hollow, preferably substantially uniform in cross-section and mass throughout, and is generally radially symmetrical, preferably in the shape of a disk or drum. To ensure that the grain or crystal structure of the disk is structurally uniform, it is preferred that the disk be formed by a precision casting as a single unit, annealed and finished by machining.
An X-ray source tube or source 36 is positioned on the disk 30 for directing an X-ray beam along the plane of the disk 30 across aperture 35 substantially perpendicular to the axis of rotation 37 . Similarly, an X-ray detector array 40 is mounted on the disk 30 opposite the source 36 for detecting emitted X-rays 38 . Additional components, for example, a data acquisition system 42 for the detector array 40 , X-ray power supply cathode 41 and anode 43 , air conditioning or cooling systems 45 and related electronics are likewise mounted on both front and rear faces 71 , 73 of the gantry disk 30 . The disk 30 is rotatably mounted to the vertical frame 32 at bearing 59 , the details of which are described below.
A motor 46 and an associated drive pulley 80 (see FIGS. 6A and 6B) coupled thereto drive a belt 64 . The belt 64 in turn is coupled to the outer perimeter of the gantry disk 30 for rotating the disk which operates as a driven pulley. The belt 64 preferably comprises a V-belt, for example a poly-V-belt, to confer various advantages described throughout the specification, including low cost, increased longevity, and reduced sensitivity to alignment. Such belts are commercially available from various vendors, for example Browning Inc., Gates Inc., Goodyear Inc., and Jason Inc.
The outer edge 65 of the disk 30 is sheaved to interface with the longitudinal grooves of the poly-V-belt 64 . The cross-sectional V-shaped geometry of the belt in combination with the large disk circumference serve to minimize belt slippage, maximizing accuracy in rotational disk positioning and rotation rate. Tension in the belt 64 is controlled by tensioner 66 which adjusts the distance between the motor drive pulley 80 (see FIG. 6) and driven disk 30 . Replacement of the belt in this configuration simply involves loosening of the belt 64 at tensioner 66 and removal and replacement of the belt 64 at the front face 71 of the disk. Removal of the disk 30 from frame 32 is unnecessary for belt service in the present configuration, and therefore the belt can be removed and replaced in a matter of minutes.
FIG. 6A is an exploded perspective view of a motor and drive pulley system and corresponding belt tensioner in accordance with the present invention. The motor 46 is coupled to the base 33 at pivot 112 . A taper bushing 84 mounts a drive sheave to the motor axle. A tensioner 66 mounted to the motor plate and adjustable by nut 67 adjusts the distance between the drive pulley 80 and the gantry disk 30 , thereby adjusting the tension of the belt 64 . The rod or tensioner 66 is threaded such that tightening of the nut 67 relative to the rod causes the motor 46 to pivot away from the gantry disk 30 thereby tensioning the belt 64 . For removing the belt 64 during servicing, the nut 67 is loosened, removing tension in the belt which can thereafter easily be removed at the front face of the gantry disk 30 .
FIG. 6B is a perspective view of an alternative belt tensioner configuration. In this embodiment, the motor 46 is mounted to a movable plate 81 which slides relative to a fixed plate 89 . A tension bolt 87 is adjustable for moving the motor 46 relative to the gantry disk 30 , thereby tensioning the belt 64 .
FIG. 3 is a rear perspective view of the gantry disk 30 and frame 32 . Gantry components mounted on the rear face 73 of the gantry disk 30 are visible in this view, for example, the rear portion of X-ray source 36 , and associated cooling systems 19 , along with power distribution assemblies, communication units, oil pumps, etc., hidden from view. To provide room for rotation of the rear-face components between the gantry disk 30 and the frame 32 , bearing 59 is distanced from the vertical frame by frame spacers or extenders 52 . Apertures 82 are provided in the gantry disk 30 to allow for mounting of components through the disk; for example X-ray source 36 passes through aperture 48 and extends from both disk faces 71 , 73 . Additional apertures 82 allow for passage of signals, power cables, and cooling fluids between components on opposite faces of the gantry disk 30 .
Slip rings and corresponding brushes (not shown) transmit power signals and high-bandwidth data signals between components of the gantry disk 30 and frame 32 . Microwave transmitter/receiver pairs provide further communication of low-bandwidth control signals. The signals are transmitted to a processing unit 83 which converts the signals to images. Air conditioner system 45 provides for circulation of air and maintains system temperature.
FIG. 4 is a sectional side view of the relationship of the gantry disk 30 , bearing 59 , and vertical frame 32 . The vertical frame 32 supports the gantry 30 system in an upright position, substantially perpendicular to the floor. Frame spacers, or extenders 52 relocate the position of the gantry bearing 59 a distance d from the frame 32 such that the various gantry components are mountable on the rear face of the gantry disk 30 without interfering with the vertical frame 32 during disk rotation. Ring frame 54 serves as a mount for the bearing 59 .
The interface between the longitudinal sheaves 50 on the outer perimeter of the gantry disk 30 and the mating longitudinal grooves on the poly-V-belt 64 is visible in the side view of FIG. 4. A close-up perspective view of this interface is shown in FIG. 7 . The poly-V-belt and sheave configuration serves to increase the surface area of the interface, thereby minimizing belt slippage.
Although the respective positions of the spacers 52 and bearing 59 could be reversed, with the spacers 52 mounted on the gantry disk 30 surface, and the bearing 59 mounted to the vertical frame 32 , such a configuration would increase the moment arm between the bearing and the center of mass of the disk, thereby increasing the radial load and trust load on the bearing. This would require a more robust and therefore more expensive bearing unit. By locating the bearing 59 near or at the center of mass of the gantry, the present invention allows for use of an inexpensive bearing configuration. This, in combination with the mounting of components on both sides of the gantry disk 30 , achieves dynamic balancing of the disk relative to the bearing, and reduces the cantilevered load on the bearing.
FIG. 5 is a close-up sectional view of the interface of bearing 59 , which is preferably configured to emulate the well-known Franke bearing interface, as disclosed in U.S. Pat. Nos. 4,797,008 and 5,071,264, incorporated herein by reference. A fixed outer bearing housing 61 mounts to the ring frame 54 by bolts 91 . Outer bearing wires 72 are deposited on each inside corner of bearing lip 77 , which serves to separate the bearing runs. An inner bearing housing, including first and second inner rings 60 , 62 respectively, mounts to the gantry disk 30 by bolts 93 . The inner housing includes inner bearing wires 74 laid along the outer corners of the inner bearing housing as illustrated. Suspended between the outer and inner wire races of bearing wires 72 , 74 are spherical ball bearings 75 , which glide across the wires with minimal resistance as the gantry disk 30 rotates. Side separators or ball spacers 76 prevent adjacent balls from contacting or otherwise interfering with each other. Preloading of the bearings is controlled by preload bolts 95 .
The bearing configuration of the present invention confers several advantages. The bearing/wire interface operates with less friction than traditional bearing races as the wires provide a smooth and efficient track for the bearings. No custom bearing housing is required, as the housing is provided by the inner surfaces of the races. The present bearing configuration requires 10 ft-lbs. of turning torque as opposed to the less efficient prior art designs requiring 50 ft-lbs. of turning torque, assuming a gantry disk of 6 feet in diameter, weighing 1500 lbs, allowing use of a smaller motor, for example a 0.5 horsepower, for rotating the gantry. Furthermore, this bearing configuration is light weight, operates quietly, and is relatively inexpensive.
An alternative bearing configuration is depicted in FIG. 8A, with a close-up cutaway side view of the bearing arrangement given in FIG. 8 B. In this configuration, the annulus, or disk 206 , is mounted for rotation within a circular gantry frame ring 202 , in turn mounted to a pivot shaft 201 . The pivot shaft 201 allows for pivoting of the entire frame at an angle relative to the translation axis through the center of the disk. The stationary mounting frame ring 202 is provided with a groove 209 A opposite a similar groove 209 B on the periphery of the rotatable annulus 206 . The opposed grooves 209 A, 209 B are shaped to receive bearings 209 , comprising wire races 212 and balls 214 , for example, the Franke bearings of the type described above. A pre-load ring 204 secured by bolts 218 secures the bearing 208 in place and urges the wire races 212 against the balls 214 . Cages 216 space the balls 214 relative to one another, as described above. An elastomer ring 210 may be mounted in either or both grooves to house the bearings and provide for more quiet operation during rotation of the disk 206 . A sheave 50 is preferably provided on the outer perimeter of the disk 206 for receiving a V-belt, conferring the advantages described above.
FIG. 9 A and FIG. 9B are a side view and a close-up cutaway view respectively of an alternative bearing configuration in accordance with the present invention. In this configuration, first and second pairs of opposed grooves 209 A, 209 B are formed on the stationary mounting frame 202 and the rotatable annulus 206 respectively. First and second bearings 208 A, 208 B are positioned in the grooves 209 to provide an interface between the frame and rotatable annulus. In this configuration, each bearing comprises first and second wire races 212 , between which balls 214 communicate. By spacing apart the bearings 208 A, 208 B on opposite sides of the center axis 217 this configuration provides for a more stable structure and therefore allows for reliable operation at increased rotation speeds.
The present invention may optionally further include a disk lock 92 (see FIG. 2) mounted to the rigid frame 32 for preventing rotation of the disk 30 , for example, during component installation or maintenance, or during shipping. In a preferred embodiment, a lock pad 93 is activated by engagement means and is urged against the drive belt 64 . As shown in the perspective close-up view of FIG. 10, the disk lock 92 includes a mount 91 fixed to the frame 32 by bolts 99 . A lock pad 93 is suspended below an extension 101 of the mount 91 , and is rotatably secured to a threaded adjustment bolt 96 interfacing with threaded hole 105 on the extension 101 . As the pad 93 position is adjusted via Allen wrench aperture 97 , guides 94 fixedly mounted to the lock pad 93 slide relative to holes 98 in the mount extension 101 . Once in position, a lock nut 103 secures the disk lock, preventing vertical movement. The lock pad 93 is preferably adapted to interface with the outer edge of the V-belt 64 as shown in FIG. 10 .
In an experimental apparatus, the gantry disk comprised a 6 ft. diameter aluminum disk weighing 1500 lbs. A commercially available poly-V-belt having 5 grooves, and commercially available at a cost of $150, was sufficient for rotating the gantry at 90 RPM, using a 1.5 horsepower motor, and delivering an angular rate accuracy better than 0.1%, exceeding the angular rate precision required for accurate scanning.
While this invention has been particularly shown and described with references 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 as defined by the appended claims. For example, while the embodiment shown in the drawings illustrate a CT Scanner of the third generation type, the invention can be used in CT Scanner of the fourth generation type.
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In an improved computed tomography scanner drive system and bearing configuration, a gantry disk ( 30 ) is sheaved about its perimeter ( 65 ) such that the gantry is operable as a driven pulley rotatable about an object to be scanned. A motor ( 46 ) assembles mounted to a stationary frame ( 33 ) includes a similar sheaved drive pulley ( 80 ). A belt ( 64 ) tensioned between the drive pulley ( 80 ) of the motor assembly and the driven pulley of the gantry disk ( 30 ) transfers rotational motion of the motor to drive the gantry rotationally about the object. In a preferred embodiment, the belt comprises a V-belt or poly-V-belt ( 64 ), and the bearing comprises a wire bearing ( 59 ) located proximal to the gantry center of mass. In this manner, the present invention provides a simple and effective technique for driving the gantry about the object, providing sufficiently accurate angular positioning in a reliable and cost effective drive system. Various embodiments of an improved bearing system are also disclosed.
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This is a continuation-in-part of U.S. patent application Ser. No. 08/242,811 which was filed on May 13, 1994, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a novel heteromultimer and its use in screening pharmaceutically active compounds for modulators of maxi-K channel activity. Such modulators are useful in treating asthma, pregnant human myometrium, cerebral ischemia and in conditions where stimulation of neurotransmitter release is desired such as Alzheimer's disease and stimulation of damaged nerves.
The present invention relates to the combined use of both the α and β subunit of a mammalian calcium-activated potassium channel originally identified and separated from bovine tracheal smooth muscle, which confers pharmacological properties to the α and β subunit complex similar to that found with the native channel. It further relates to the use of the α-β heteromultimer in expression systems as assays for agonists or antagonists of calcium-activated potassium channels.
Potassium channel antagonists are useful for a number of physiological disorders in mammals, including humans. Ion channels, including potassium channels, are found in all mammalian cells and are involved in the modulation of various physiological processes and normal cellular homeostasis. Potassium channels generally control the resting membrane potential, and the efflux of potassium ions causes repolarization of the plasma membrane after cell depolarization. Potassium channel antagonists prevent repolarization and cause the cell to stay in the depolarized, excited state.
There are a number of potassium channel subtypes. Physiologically, one important subtype is the maxi-K channel, defined as high -conductance calcium-activated potassium channel, which is present in neuronal tissue and smooth muscle. Intracellular calcium concentration (Ca 2+ i ) and membrane potential gate these channels. For example, maxi-K channels are opened to enable efflux of potassium ions by an increase in the intracellular Ca 2+ concentration or by membrane depolarization (change in potential). Elevation of intracellular calcium concentration is required for neurotransmitter release, smooth muscle contraction, proliferation of some cell types and other processes. Modulation of maxi-K channel activity therefore affects cellular processes that depend on influx of calcium through voltage-dependent pathways, such as transmitter release from the nerve terminals and smooth muscle contraction. The screening procedures revealed by the present invention are therefore useful for detecting compounds with utility in the treatment of neurological disorders in which neurotransmitter release is impaired.
A number of marketed drugs function as potassium channel antagonists. The most important of these include the compounds Glyburide, Glipizide and Tolbutamide. These potassium channel antagonists are useful as antidiabetic agents. Potassium channel antagonists are also utilized as Class III antiarrhythmic agents and to treat acute infractions in humans. A number of naturally occurring toxins are known to block potassium channels including apamin, iberiotoxin, charybdotoxin, margatoxin, noxiustoxin, kaliotoxin, dendrotoxin(s), mast cell degranuating (MCD) peptide, and β-bungarotoxin (β-BTX).
Depression is related to a decrease in neurotransmitter release. Current treatments of depression include blockers of neurotransmitter uptake, and inhibitors of enzymes involved in neurotransmitter degradation which act to prolong the lifetime of neurotransmitters.
It is believed that certain diseases such as depression, memory disorders and Alzheimer's disease are the result of an impairment in neurotransmitter release. Potassium channel antagonists may therefore be utilized as cell excitants which should stimulate release of neurotransmitters such as acetylcholine, serotonin and dopamine. Enhanced neurotransmitter release should reverse the symptoms associated with depression and Alzheimer's disease.
The present invention relates to the use of the calcium activated potassium channel α and β subunits in transient or stable coexpression systems as assays for antagonists of maxi-K channels. Such blockers are useful in diseases where neurotransmission is deficient, such as Alzheimer's or depression.
The present invention also relates to the use of the α and β subunits in transient or stable coexpression systems as assays to screen for agonists of maxi-K channels. Such agonists are useful in diseases involving excessive smooth muscle tone or excitability such as asthma, angina, hypertension, incontinence, pre-term labor, migraine, cerebral ischemia and irritable bowl syndrome. Such agonists also act to decrease neurotransmitter or hormone release, and thus are of use in treating diseases such as asthma, cerebral ischemia and pain modulation. Specifically such agents can act to decrease release of tachykinins, such as substance P and neurokinin A, among others, that are involved in the neurogenic intimation that occurs in asthma. Thus, agonists of maxi-K channels would be expected to decrease neurogenic inflamation and be useful in the treatment of asthma.
Agonists of maxi-K channels hyperpolarize neurons and thereby, decrease calcium entry through both voltage-dependent calcium channels and through excitatory neurotransmitter activated channels. Since elevation of intracellular calcium is part of the process which leads to cell damage, reduction in calcium entry would decrease neural damage in cerebral ischemia.
SUMMARY OF THE INVENTION
The present invention is directed to an isolated and purified DNA molecule which encodes a β subunit of a mammalian calcium activated potassium channel or a functional derivative thereof. It is further directed to an expression vector for expression of a β subunit of a mammalian calcium-activated potassium channel in a recombinant host, wherein said vector contains a recombinant gene encoding a β subunit of a mammalian calcium-activated potassium channel or functional derivative thereof. Further this novel invention is directed to a recombinant host cell containing a recombinantly cloned gene encoding a β subunit of a mammalian calcium-activated potassium channel or functional derivative thereof. In addition, the instant invention is directed to a protein, in substantially pure form which functions as a β subunit of a mammalian calcium-activated potassium channel. The invention is also directed to a monospecific antibody immunologically reactive with a β subunit of a mammalian calcium-activated potassium channel and a process for expression of a β subunit of a mammalian calcium-activated potassium channel protein in a recombinant host cell, comprising:
(a) transferring the expression vector containing a recombinant gene encoding a αβ subunit of a mammalian calcium-activated potassium channel or functional derivative thereof into suitable host cells; and
(b) culturing the host cells of step (a) under conditions which allow expression of the β subunit of a mammalian high-conductance, calcium-activated potassium channel protein from the expression vector.
Further, this invention is directed to a novel method of identifying compounds that modulate β subunit of a mammalian calcium-activated potassium channel activity, comprising:
(a) combining a suspected modulator of β subunit of a mammalian high-conductance, calcium-activated potassium channel activity with α and β subunits of a mammalian high-conductance, calcium-activated potassium channel; and
(b) measuring an effect of the modulator on the channel.
In addition, this invention is directed to a novel method of identifying compounds that modulate the activity of a heteromultimer of α and β subunits of a mammalian calcium-activated potassium channel, comprising:
(a) combining a suspected modulator of a mammalian calcium-activated potassium channel activity with α and β subunits of a calcium-activated potassium channel; and
(b) measuring an effect of the modulator on the heteromultimer.
This invention is also directed to a compound active in the aforementioned method, wherein said compound is a modulator of a mammalian calcium-activated potassium channel. Further, this invention is directed to a pharmaceutical composition comprising a compound active in the aforementioned method, wherein said compound is a modulator of mammalian calcium-activated potassium channel activity. Additionally, this invention is directed to a novel treatment of a patient in need of such treatment for a condition which is mediated by a mammalian calcium-activated potassium channel, comprising administration of an α and β subunit of a mammalian calcium-activated potassium channel modulating compound active in the aforementioned method This invention is further directed to a method of treating a patient in need of such treatment for a condition which is mediated by a mammalian calcium-activated potassium channel and is characterized by alterations in smooth muscle tone, release of neurotransmitter substances or hormones and excitability of neurons, comprising administration of an α and β subunit of a mammalian calcium-activated potassium channel modulating compound active in the above mentioned method. This invention is also directed to a method of identifying compounds that modulate mammalian calcium-activated potassium channel activity, comprising:
(a) combining a suspected modulator of β subunit of a mammalian calcium-activated potassium channel activity with a cell expressing recombinant α and β subunit of a mammalian calcium-activated potassium channel; and
(b) measuring an effect of the modulator on the channel.
This invention is also directed to a compound active in the method of identifying compounds that modulate mammalian calcium-activated potassium channel activity wherein said compound is a modulator of a heteromultimer composed of the α and β subunit of a mammalian calcium-activated potassium channel. This invention is also directed to a method of treating a patient in need of such treatment for a condition which is mediated by a β subunit, comprising administration of a β subunit of a mammalian calcium-activated potassium channel modulating compound active in the method of identifying compounds that modulate mammalian calcium-activated potassium channel activity. This invention is also directed to a method of treating a patient in need of such treatment for a condition which is mediated by a β subunit of a mammalian calcium-activated potassium channel and is characterized by inflammation, hyper-contractility of smooth muscle, neural ischemia, or neural degeneration, comprising administration of a β subunit of a mammalian calcium-activated potassium channel modulating compound active in the method of identifying compounds that modulate mammalian calcium-activated potassium channel activity.
BRIEF DESCRIPTION OF THE FIGURES
Sequence I.D. No. 1 is the isolated and purified DNA molecule which encodes a β-subunit of a mammalian (bovine) high-conductance, calcium activated potassium channel.
Sequence I.D. No. 2 is the amino acid sequence of β subunit (bovine). The amino acids shown in Sequence No. 2 are represented by a single letter. The legend for these amino acids is as follows:
______________________________________Amino Acid One Letter______________________________________Alanine AArginine RAsparagine NAspartic DAsparagine or Aspartic BCysteine CGlycine GGlutamine QGlutamic EGlutamine or Glutamic ZHistidine HIsoleucine ILeucine LLysine KMethionine MPhenylalanine FProline PSerine SThreonine TTryptophan WTyrosine YValine V______________________________________
Sequence I.D. No. 3 is the isolated and purified DNA molecule which encodes a β-subunit of a human high-conductance, calcium activated potassium channel.
Sequence I.D. No. 4 is the amino acid sequence of human β-subunit. The amino acids shown in Sequence No. 4 are represented by a single letter. The legend for these amino acids is as shown above for FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to DNA encoding a beta-subunit of a mammalian calcium-activated potassium channel (β subunit) which was isolated from β subunit producing cells.
By "calcium activated potassium channel" is meant high conductance, intermediate conductance or small conductance calcium activated potassium channels. In general, the "high conductance channel", also known as the "maxi-K channel", is defined as having greater than 200 pS conductance in a membrance exposed to about 150 mμ KCl on both sides.
The isolated and purified DNA molecule which encodes a β subunit of a bovine high-conductance, calcium activated potassium channel has a nucleotide sequence shown in Sequence No.1.
"β subunit", as used herein, refers to protein which can specifically function as the β subunit of mammalian calcium-activated potassium channels. The amino acid sequence of bovine β subunit is shown in Sequence No.2.
The isolated and purified DNA molecule which encodes a β subunit of a human high-conductance, calcium activated potassium channel has a nucleotide sequence shown in Sequence No.3.
The amino acid sequence of human β subunit is shown in as Sequence No.4.
High-conductance calcium-activated potassium (maxi-K) channels in smooth muscle are composed of two distinct subunits,α and β (M. Garcia-Calvo, H.-G. Knaus, O. B. McManus, K. M. Giangiacomo, G. J. Kaczorowski and M. L. Garcia, The Journal of Biological Chemistry 269, 676-683 (1994)). Peptide sequence derived from the α subunit is homologous to the protein product of the mSlo gene and is therefore a member of the mSlo gene family (H.-G. Knaus, M. Garcia-Calvo, G. J. Kaczorowski and M. L. Garcia, The Journal of Biological Chemistry 269, 3921-3924 (1994)). mSlo is a mouse homologue (A. Butler, S. Tsunoda, D. P. McCobb, A. Wei and L. Salkoff, Science 261, 221-224 (1993)) of the gene product from the Drosophila gene locus that is disrupted in slowpoke mutants that lack calcium-activated potassium channels (N. S. Atkinson, G. A. Robertson and B. Ganetzky, Science 253, 551-555 (1991)). RNA transcribed in vitro from mSlo cDNA and injected into Xenopus oocytes caused the expression of calcium-activated potassium channels with a large single channel conductance indicating that the mSlo gene product is a structural component of maxi-K channels.
The amino acid and DNA sequences of the β subunit were not previously known. Discovery of the β subunit required purification and functional reconsfitution of the maxi-K channel from bovine smooth muscle (M. Garcia-Calvo, H.-G. Knaus, O. B. McManus, K. M. Giangiacomo, G. J. Kaczorowski and M. L. Garcia, The Journal of Biological Chemistry 269, 676-683 (1994)). The channel purified from bovine tracheal smooth muscle possessed the properties of the native channel from that tissue. 125 I-ChTX bound to the purified channel with a binding affinity similar to the affinity for 125 I-ChTX binding to the native maxi-K channel. Binding of 125 I-ChTX to the purified maxi-K channel was inhibited by ChTX, iberiotoxin (IbTX), limbatustoxin (LbTX), barium, potassium, cesium and tetraethylammonium in a manner similar to inhibition by these compounds of 125 I-ChTX binding to maxi-K channels found in native tissue. Thus, the pharmacological properties of the purified channels resembled the maxi-K channels found in native tissues. Direct evidence that the purified channel is the maxi-K channel found in native tissue comes from reconstitution experiments. Proteoliposomes containing the purified channel were fused with planar lipid bilayers. Channels were then observed with a large single channel conductance (>200 pS) that were selectively permeable to potassium, and whose open probability was increased by increasing concentrations of intracellular calcium and by membrane depolarization. These are the biophysical properties of maxi-K channels observed in native tissues.
The purified β subunit is a glycoprotein with an Mr of 31 kDa. Deglycosylation studies suggest that carbohydrate is attached to the β subunit by N-linked glycosylation at least at two sites, and that the β subunit is the protein to which 125 I-ChTX becomes covalently linked to the maxi-K channel with the bifunctional crosslinking reagent, disuccinimidyl subcrate (M. Garcia-Calvo, H.-G. Knaus, O. B. McManus, K. M. Giangiacomo, G. J. Kaczorowski and M. L. Garcia, The Journal of Biological Chemistry 269, 676-683 (1994)). Peptide sequencing of a proteolytic fragment obtained from the purified β subunit revealed a unique sequence that was used to construct oligonucleotide probes with which cDNAs encoding the β subunit were isolated. The cDNAs encode a protein with little sequence homology to subunits of other known ion channels. The cDNAs encode a protein containing 191 amino acids with two hydrophobic regions that may form transmembrane domains and two potential sites for N-linked glycosylation at asparagine residues located in the putative extracellular domain. Antibodies raised against peptide sequences contained in the putative extracellular domain of the β subunit specifically immunoprecipitated β subunit labeled with 125 I Bolton-Hunter reagent, as well as the 125 I-ChTX crosslinked β subunit. Under non-denaturing conditions, anti-β subunit anti-sera specifically immunoprecipatated a complex containing both the α and β subunits. Therefore, the purified and cloned β subunit described herein is part of the complex comprising the maxi-K channel.
Direct evidence that the β subunit described herein is a functional part of the maxi-K channel comes from coexpression studies with α and β subunits. The cDNA encoding the β subunit was used to synthesize cRNA in vitro. This cRNA was injected into Xenopus oocytes along with cRNA encoding an α subunit isolated from mouse brain (GenBank Accession #U09383). Membrane currents in the oocytes were measured with standard two microelectrode voltage-clamp methods. Membrane patches were excised from oocytes in the inside-out configuration, and currents through these patches were measured with patch-clamp methods. In these excised-patch experiments, both the membrane potential and intracellular calcium concentration were controlled. Oocytes injected with cRNA encoding the β subunit alone did not exhibit any currents that were distinguishable from background currents observed in uninjected oocytes. Oocytes injected with cRNA encoding the α subunit alone exhibited outward potassium currents that were blocked by ChTX and IbTX. Membrane patches excised from oocytes injected with cRNA encoding α alone contained large-conductance (>200 pS) potassium channels that were selective for potassium over sodium, and whose open probability was increased by increasing intracellular calcium and by membrane depolarization. The open probability of channels from oocytes injected with cRNA encoding the α subunit alone was not increased after exposure to 100-500 nM of dehydrosoyasaponin I (DHS-I), a potent activator of maxi-K channels from aortic and tracheal smooth muscle (O. B. McManus, G. H. Harris, K. M. Giagiacomo, P. Feigenbaum, J. P. Reuben, M. E. Addy, J. F. Burka, G. J. Kaczorowski and M. L. Garcia, Biochemistry 32, 6128-6133 (1993)).
Oocytes injected with cRNAs encoding both the α and β subunits exhibited outward potassium currents that were blocked by ChTX and IbTX. These currents were expressed at amplitudes similar to the currents observed in oocytes injected with cRNAs encoding the α subunit alone. The outward currents observed in oocytes injected with α and β subunits were activated at more negative potentials than the oocytes injected with α subunit cRNA alone. Direct evidence for a difference in channel gating between channels in oocytes injected with cRNA encoding the α subunit alone, and channels in oocytes injected with cRNAs encoding both the α and β subunits, comes from recordings of currents in membrane patches excised from each type of oocyte. Maxi-K channels observed in α and β subunit-injected oocytes had a large single channel conductance (>200 pS), and these channels were selective for potassium over sodium. The open probability of these channels was increased by increasing intracellular calcium concentrations and by membrane depolarization. The gating of the channels in oocytes injected with both α and β subunit cRNAs differed from the gating of channels from oocytes injected with α subunit cRNA alone. The channels from oocytes expressing both subunits were activated at more negative membrane potentials than were channels expressing the α subunit unit alone. At a given concentration of intracellular calcium, channels from oocytes expressing both subunits were activated at membrane potentials 50 to 100 mV more negative than were channels from oocytes expressing the α subunit alone. Channels from oocytes expressing both subunits were fully activated by 100-300 nM of DHS-I applied to the intracellular face of the channel. Thus, addition of the β subunit shifted the voltage-dependence of gating of channels encoded by the α subunit and conferred sensitivity to an activator of maxi-K channels. Therefore, the β subunit co-assembles with the α subunit and forms calcium-activated potassium channels with pharmacological and biophysical properties that differ from calcium-activated potassium channels encoded by the α subunit alone and which more closely resemble maxi-K channels in native tissues.
The α and β subunits can be transiently or stably co-expressed in cell lines that can then be used to screen for modulators of calcium-activated potassium channels. Cell lines expressing both subunits offer advantages over cell lines expressing the α subunit alone. Coexpression of the α and β subunits produces novel hetero-multimeric channels whose gating is more sensitive to intracellular calcium and depolarizing membrane potential. Such hetero-multimeric channels can be more easily induced to open and thus provide a more sensitive assay system for agents that open maxi-K channels and for agents that block maxi-K channels.
DNA encoding the β subunit from bovine trachea may be used to isolate and purify homologues of β subunits from other organisms, including humans. To accomplish this, the first β subunit DNA may be mixed with a sample containing DNA encoding homologues of β subunit under appropriate hybridization conditions. The hybridized DNA complex may be isolated and the DNA encoding the homologous DNA may be purified therefrom.
Because the genetic code is degenerate, more than one codon may be used to encode a particular amino acid, and therefore, the amino acid sequence can be encoded by any of a set of similar DNA oligonucleotides. Only one member of the set will be identical to the β subunit sequence, but will be capable of hybridizing to β subunit DNA even in the presence of DNA oligonucleotides with mismatches under appropriate conditions. Under alternate conditions, the mismatched DNA oligonucleotides may still hybridize to the β subunit DNA to permit identification and isolation of β subunit encoding DNA.
It is known that there is a substantial amount of redundancy in the various codons which code for specific amino acids. Therefore, this invention is also directed to those DNA sequences which contain alternative codons which code for the eventual translation of the identical amino acid. For purposes of this specification, a sequence bearing one or more replaced codons will be defined as a degenerate variation. Also included within the scope of this invention are mutations either in the DNA sequence or the translated protein which do not substantially alter the ultimate physical properties of the expressed protein. For example, substitution of valine for leucine, arginine for lysine, or asparagine for glutamine may not cause a change in functionality of the polypeptide.
It is known that DNA sequences coding for a peptide may be altered so as to code for a peptide having properties that are different than those of the naturally-occurring peptide. Methods of altering the DNA sequences include, but are not limited to site directed mutagenesis. Examples of altered properties include, but are not limited to changes in the affinity of an enzyme for a substrate or a receptor for a ligand.
As used herein, a "functional derivative" of β subunit is a compound that possesses a biological activity (either functional or structural) that is substantially similar to the biological activity of β subunit. The term "functional derivatives" is intended to include the "fragments," "variants," "degenerate variants," "analogs" and "homologues", and to "chemical derivatives" of β subunit. The term "fragment" is meant to refer to any polypeptide subset of β subunit. The term "variant" is meant to refer to a molecule substantially similar in structure and function to either the entire β subunit molecule or to a fragment thereof. A molecule is "substantially similar" to β subunit if both molecules have substantially similar structures or if both molecules possess similar biological activity. Therefore, if the two molecules possess substantially similar activity, they are considered to be variants even if the structure of one of the molecules is not found in the other or even if the two amino acid sequences are not identical.
The term "analog" refers to a molecule substantially similar in function to either the entire β subunit molecule, or to a fragment thereof.
The cloned β subunit DNA obtained through the methods described herein may be recombinantly expressed by molecular cloning into an expression vector containing a suitable promoter and other appropriate transcription regulatory elements, and transferred into prokaryotic or eukaryotic host cells to produce recombinant β subunit. Techniques for such manipulations are fully described in Sambrook, J., et al., Molecular Cloning Second Edition, 1990, Cold Spring Harbor Press and are well known in the art.
Expression vectors are defined herein as DNA sequences that are required for the transcription of cloned copies of genes and the translation of their mRNAs in an appropriate host. Such vectors can be used to express eukaryotic genes in a variety of hosts such as bacteria, bluegreen algae, plant cells, insect cells, fungal cells and animal cells.
Specifically designed vectors allow the shuttling of DNA between hosts such as bacteria-yeast, or bacteria-animal cells, or bacteria-fungal cells, or bacteria-invertebrate cells. An appropriately constructed expression vector should contain: an origin of replication for autonomous replication in host cells, selectable markers, a limited number of useful restriction enzyme sites, a potential for high copy number, and active promoters. A promoter is defined as a DNA sequence that directs RNA polymerase to bind to DNA and initiate RNA synthesis. A strong promoter is one which causes mRNAs to be initiated at high frequency. Expression vectors may include, but are not limited to, cloning vectors, modified cloning vectors, specifically designed plasmids or viruses.
A variety of mammalian expression vectors may be used to express recombinant β subunit in mammalian cells along with the α subunit. Commercially available mammalian expression vectors which are suitable for recombinant β subunit expression, include but are not limited to, pcDNA3 (Invitrogen), pMC1neo (Stratagene), pXT1 (Stratagene), pSG5 (Stratagene), EBO-pSV2-neo (ATCC 37593) pBPV-1(8-2) (ATCC 37110), pdBPV-MMTneo(342-12) (ATCC 37224), pRSVgpt (ATCC 37199), pRSVneo (ATCC 37198), pSV2-dhfr (ATCC 37146), pUCTag (ATCC 37460), and lZD35 (ATCC 37565).
A variety of bacterial expression vectors may be used to express recombinant β subunit in bacterial cells along with the α subunit. Commercially available bacterial expression vectors which may be suitable for recombinant β subunit expression include, but are not limited to pET11a (Novagen), lambda gt11 (Invitrogen), pcDNAII (Invitrogen), pKK223-3 (Pharmacia).
A variety of insect cell expression vectors may be used to express recombinant β subunit in insect cells along with the α subunit. Commercially available insect cell expression vectors which may be suitable for recombinant expression of β subunit include but are not limited to pBlue Bac III (Invitrogen).
An expression vector containing DNA encoding β subunit may be used for expression of β subunit in a recombinant host cell along with the α subunit. Recombinant host cells may be prokaryotic or eukaryotic, including but not limited to bacteria such as E. coli, fungal cells such as yeast, mammalian cells including but not limited to cell lines of human, bovine, porcine, monkey and rodent origin, and insect cells including but not limited to Drosophila and silkworm derived cell lines. Cell lines derived from mammalian species which may be suitable and which are commercially available, include but are not limited to, L cells L-M(TK - ) (ATCC CCL 1.3), L cells L-M (ATCC CCL 1.2), 293 (ATCC CRL 1573), Raji (ATCC CCL 86), CV-1 (ATCC CCL 70), COS-1 (ATCC CRL 1650), COS-7 (ATCC CRL 1651), CHO-K1 (ATCC CCL 61), 3T3 (ATCC CCL 92), NIH/3T3 (ATCC CRL 1658), HeLa (ATCC CCL 2), C127I (ATCC CRL 1616),BS-C-1 (ATCC CCL 26) and MRC-5 (ATCC CCL 171).
The expression vector may be introduced into host cells expressing the α subunit via any one of a number of techniques including but not limited to transformation, transfection, lipofection, protoplast fusion, and electroporation. The expression vector-containing cells are clonally propagated and individually analyzed to determine whether they produce β subunit protein. Identification of β subunit expressing host cell clones also expressing the α subunit may be done by several means, including but not limited to immunological reactivity with anti-β subunit antibodies, and the presence of host cell-associated β subunit activity, such as sensitivity of expressed maxi-K channels to DHS-I, and ability to covalently cross-link 125 I-ChTX to the β subunit with the bifunctional cross-linking reagent disuccinimidyl suberate or similar cross-linking reagents.
Co-expression of α and β subunit DNAs may also be performed using in vitro produced synthetic mRNA or native mRNA. Synthetic mRNA or mRNA isolated from α and β subunit producing cells can be efficiently translated in various cell-free systems, including but not limited to wheat germ extracts and reticulocyte extracts, as well as efficiently translated in cell based systems, including but not limited to microinjection into frog oocytes, with microinjection into frog oocytes being preferred.
Following expression of β subunit in a recombinant host cell which may also be expressing the α subunit, β subunit protein or maxi-K channels consisting of α-β heteromultimers may be recovered to provide β subunit or maxi-K channels in purified form. Several β subunit and maxi-K channel purification procedures are available and suitable for use. As described herein, recombinant β subunit and maxi-K channels may be purified from cell lysates and extracts by various combinations of, or individual application of salt fractionation, ion exchange chromatography, size exclusion chromatography, hydroxylapatite adsorption chromatography and hydrophobic interaction chromatography.
In addition, recombinant β subunit and maxi-K channels can be separated from other cellular proteins by use of an immunoaffinity column made with monoclonal or polyclonal antibodies specific for full length nascent β subunit, or polypeptide fragments of β subunit.
Monospecific antibodies to β subunit are purified from mammalian antisera containing antibodies reactive against β subunit or are prepared as monoclonal antibodies reactive with β subunit using the technique of Kohler and Milstein, Nature 256, 495-497 (1975). Mono-specific antibody as used herein is defined as a single antibody species or multiple antibody species with homogenous binding characteristics for β subunit. Homogenous binding as used herein refers to the ability of the antibody species to bind to a specific antigen or epitope, such as those associated with the β subunit, as described above. β subunit specific antibodies are raised by immunizing animals such as mice, rats, guinea pigs, rabbits, goats, horses and the like, with rabbits being preferred, with an appropriate concentration of β subunit either with or without an immune adjuvant.
Preimmune serum is collected prior to the first immunization. Each animal receives between about 0.1 mg and about 1000 mg of β subunit associated with an acceptable immune adjuvant. Such acceptable adjuvants include, but are not limited to, Freund's complete, Freund's incomplete, alum-precipitate, water in oil emulsion containing Corynebacterium parvum and tRNA. The initial immunization consists of β subunit in, preferably, Freund's complete adjuvant at multiple sites either subcutaneously (SC), intraperitoneally (IP) or both. Each animal is bled at regular intervals, preferably weekly, to determine antibody titer. The animals may or may not receive booster injections following the initial immunization. Those animals receiving booster injections are generally given an equal amount of the antigen in Freund's incomplete adjuvant by the same route. Booster injections are given at about three week intervals until maximal titers are obtained. At about 7 days after each booster immunization or about weekly after a single immunization, the animals are bled, the serum collected, and aliquots are stored at about -20° C.
Monoclonal antibodies (mAb) reactive with β subunit are prepared by immunizing inbred mice, preferably Balb/c, with β subunit. The mice are immunized by the IP or SC route with about 0.1 mg to about 10 mg, preferably about 1 mg, of β subunit in about 0.5 ml buffer or saline incorporated in an equal volume of an acceptable adjuvant, as discussed above. Freund's complete adjuvant is preferred. The mice receive an initial immunization on day 0 and are rested for about 3 to about 30 weeks. Immunized mice are given one or more booster immunizations of about 0.1 to about 10 mg of β subunit in a buffer solution such as phosphate buffered saline by the intravenous (IV) route. Lymphocytes, from antibody positive mice, preferably splenic lymphocytes, are obtained by removing spleens from immunized mice by standard procedures known in the art. Hybridoma cells are produced by mixing the splenic lymphocytes with an appropriate fusion partner, preferably myeloma cells, under conditions which will allow the formation of stable hybridomas. Fusion partners may include, but are not limited to: mouse myelomas P3/NS1/Ag 4-1; MPC-11; S-194 and Sp 2/0, with Sp 2/0 being preferred. The antibody producing cells and myeloma cells are fused in polyethylene glycol, about 1000 molecular weight, at concentrations from about 30% to about 50%. Fused hybridoma cells are selected by growth in hypoxanthine, thymidine and aminopterin supplemented Dulbecco's Modified Eagles Medium (DMEM) by procedures known in the art. Supernatant fluids are collected from growth positive wells on about days 14, 18, and 21 and are screened for antibody production by an immunoassay such as solid phase immunoradioassay (SPIRA) using β subunit as the antigen. The culture fluids are also tested in the Ouchterlony precipitation assay to determine the isotype of the mAb. Hybridoma cells from antibody positive wells are cloned by a technique such as the soft agar technique of MacPherson, Soft Agar Techniques, in Tissue Culture Methods and Applications, Kruse and Paterson, Eds., Academic Press, 1973.
Monoclonal antibodies are produced in vivo by injection of pristane primed Balb/c mice, approximately 0.5 ml per mouse, with about 2×10 6 to about 6×10 6 hybridoma cells about 4 days after priming. Ascites fluid is collected at approximately 8-12 days after cell transfer and the monoclonal antibodies are purified by techniques known in the art.
In vitro production of anti-β subunit mAb is carried out by growing the hydridoma in DMEM containing about 2% fetal calf serum to obtain sufficient quantities of the specific mAb. The mAb are purified by techniques known in the art.
Antibody titers of ascites or hybridoma culture fluids are determined by various serological or immunological assays which include, but are not limited to, precipitation, passive agglutination, enzyme-linked immunosorbent antibody (ELISA) technique and radioimmunoassay (RIA) techniques. Similar assays are used to detect the presence of β subunit in body fluids or tissue and cell extracts.
It is readily apparent to those skilled in the art that the above described methods for producing monospecific antibodies may be utilized to produce antibodies specific for β subunit polypeptide fragments, or the full-length nascent β subunit polypeptide. Specifically, it is readily apparent to those skilled in the art that monospecific antibodies may be generated which are specific for the fully functional receptor or fragments thereof.
β subunit antibody affinity columns are made by adding the antibodies to Affigel-10 (Biorad), a gel support which is activated with N-hydroxysuccinimide esters such that the antibodies form covalent linkages with the agarose gel bead support. The antibodies are then coupled to the gel via amide bonds with the spacer arm. The remaining activated esters are then quenched with 1M ethanolamine HCl (pH 8). The column is washed with water followed by 0.23M glycine HCl (pH 2.6) to remove any non-conjugated antibody or extraneous protein. The column is then equilibrated in phosphate buffered saline (pH 7.3) with appropriate detergent and the cell culture supernatants or cell extracts containing β subunit or maxi-K channels made using appropriate membrane solubilizing detergents are slowly passed through the column. The column is then washed with phosphate buffered saline/detergent until the optical density (A 280 ) falls to background, then the protein is eluted with 0.23M glycine-HCl (pH 2.6)/detergent. The purified β subunit protein or maxi-K channel is then dialyzed against phosphate buffered saline/detergent.
The present invention is also directed to methods for screening for compounds which modulate the expression of DNA or RNA encoding β subunit, as well as the function of β subunit protein in vivo. Compounds which modulate these activities may be DNA, RNA, peptides, proteins, or non-proteinaceous organic molecules. Compounds may modulate by increasing or attenuating the expression of DNA or RNA encoding β subunit, or the function of β subunit protein. Compounds that modulate the expression of DNA or RNA encoding β subunit or the function of β subunit protein may be detected by a variety of assays. The assay may be a simple "yes/no" assay to determine whether there is a change in expression or function. The assay may be made quantitative by comparing the expression or function of a test sample with the levels of expression or function in a standard sample.
Kits containing β subunit DNA, antibodies to β subunit, or β subunit protein may be prepared. Such kits are used to detect DNA which hybridizes to β subunit DNA, or to detect the presence of β subunit protein or peptide fragments in a sample. Such characterization is useful for a variety of purposes including, but not limited to, forensic analyses and epidemiological studies.
The DNA molecules, RNA molecules, recombinant protein and antibodies of the present invention may be used to screen and measure levels of β subunit DNA, β subunit RNA or β subunit protein. The recombinant proteins, DNA molecules, RNA molecules and antibodies lend themselves to the formulation of kits suitable for the detection and typing of β subunit. Such a kit would comprise a compartmentalized carrier suitable to hold in close confinement at least one container. The carrier would further comprise reagents such as recombinant β subunit protein or anti-β subunit antibodies suitable for detecting β subunit. The carrier may also contain a means for detection such as labeled antigen or enzyme substrates or the like.
Nucleotide sequences that are complementary to the β sub-unit encoding DNA sequence can be synthesized for antisense therapy. These antisense molecules may be DNA, stable derivatives of DNA such as phosphorothioates or methylphosphonates, RNA, stable derivatives of RNA such as 2'-O-alkylRNA, or other β subunit antisense oligonucleotide mimetics. β subunit antisense molecules may be introduced into cells by microinjection, liposome encapsulation or by expression from vectors harboring the antisense sequence. β subunit antisense therapy may be particularly useful for the treatment of diseases where it is beneficial to reduce β subunit or maxi-K channel activity.
β subunit gene therapy may be used to introduce β subunit into the cells of target organs. The β subunit gene can be ligated into viral vectors which mediate transfer of the β subunit DNA by infection of recipient host cells. Suitable viral vectors include retrovirus, adenovirus, adeno-associated virus, herpes virus, vaccinia virus, polio virus and the like. Alternatively, β subunit DNA can be transferred into cells for gene therapy by non-viral techniques including receptor-mediated targeted DNA transfer using ligand-DNA conjugates or adenovirus-ligand-DNA conjugates, lipofection membrane fusion or direct microinjection. These procedures and variations thereof are suitable for ex vivo, as well as in vivo β subunit gene therapy. β subunit gene therapy may be particularly useful for the treatment of diseases where it is beneficial to elevate β subunit activity.
Pharmaceutically useful compositions comprising β subunit DNA, β subunit RNA, or β subunit protein, or modulators of β subunit or maxi-K channel activity, may be formulated according to known methods such as by the admixture of a pharmaceutically acceptable carrier. Examples of such carriers and methods of formulation may be found in Remington's Pharmaceutical Sciences. To form a pharmaceutically acceptable composition suitable for effective administration, such compositions will contain an effective amount of the protein, DNA, RNA, or modulator.
Therapeutic or diagnostic compositions of the invention are administered to an individual in amounts sufficient to treat or diagnose β subunit or maxi-K channel related disorders. The effective amount may vary according to a variety of factors such as the individual's condition, weight, sex and age. Other factors include the mode of administration.
The pharmaceutical compositions may be provided to the individual by a variety of routes such as subcutaneous, topical, oral and intramuscular.
The term "chemical derivative" describes a molecule that contains additional chemical moieties which are not normally a part of the base molecule. Such moieties may improve the solubility, half-life, absorption, etc. of the base molecule. Alternatively the moieties may attenuate undesirable side effects of the base molecule or decrease the toxicity of the base molecule. Examples of such moieties are described in a variety of texts, such as Remington's Pharmaceutical Sciences.
Compounds identified according to the methods disclosed herein may be used alone at appropriate dosages defined by routine testing in order to obtain optimal modulation of a maxi-K channel that consists of α and β subunits, or its activity while minimizing any potential toxicity. In addition, co-administration or sequential administration of other agents may be desirable.
The present invention also has the objective of providing suitable topical, oral, systemic and parenteral pharmaceutical formulations for use in the novel methods of treatment of the present invention. The compositions containing compounds identified according to this invention as the active ingredient for use in the modulation of maxi-K channels can be administered in a wide variety of therapeutic dosage forms in conventional vehicles for administration. For example, the compounds can be administered in such oral dosage forms as tablets, capsules (each including timed release and sustained release formulations), pills, powders, granules, elixirs, tinctures, solutions, suspensions, syrups and emulsions, or by injection. Likewise, they may also be administered in intravenous (both bolus and infusion), intraperitoneal, subcutaneous, topical with or without occlusion, or intramuscular form, all using forms well known to those of ordinary skill in the pharmaceutical arts. An effective but non-toxic amount of the compound desired can be employed as a β subunit or maxi-K channel modulating agent.
The daily dosage of the products may be varied over a wide range from 0.01 to 1,000 mg per adult human/per day. For oral administration, the compositions are preferably provided in the form of scored or unscored tablets containing 0.01, 0.05, 0.1, 0.5, 1.0, 2.5, 5.0, 10.0, 15.0, 25.0, and 50.0 milligrams of the active ingredient for the symptomatic adjustment of the dosage to the patient to be treated. An effective amount of the drug is ordinarily supplied at a dosage level of from about 0.0001 mg/kg to about 100 mg/kg of body weight per day. The range is more particularly from about 0.001 mg/kg to 10 mg/kg of body weight per day. Even more particularly, the range varies from about 0.05 to about 1 mg/kg. Of course the dosage level will vary depending upon the potency of the particular compound. Certain compounds will be more potent than others. In addition, the dosage level will vary depending upon the bioavailability of the compound. The more bioavailable and potent the compound, the less compound will need to be administered through any delivery route, including but not limited to oral delivery. The dosages of the β subunit or maxi-K channel modulators are adjusted when combined to achieve desired effects. On the other hand, dosages of these various agents may be independently optimized and combined to achieve a synergistic result wherein the pathology is reduced more than it would be if either agent were used alone.
Advantageously, compounds of the present invention may be administered in a single daily dose, or the total daily dosage may be administered in divided doses of two, three or four times daily. Furthermore, compounds for the present invention can be administered in intranasal form via topical use of suitable intranasal vehicles, or via transdermal routes, using those forms of transdermal skin patches well known to those of ordinary skill in that art. Dosage forms that provide for sustained or continuous delivery of these compounds is also within the scope of this invention.
For combination treatment with more than one active agent, where the active agents are in separate dosage formulations, the active agents can be administered concurrently, or they each can be administered at separately staggered times.
The dosage regimen utilizing the compounds of the present invention is selected in accordance with a variety of factors including type, species, age, weight, sex and medical condition of the patient; the severity of the condition to be treated; the route of administration; the renal and hepatic function of the patient; and the particular compound thereof employed. A physician or veterinarian of ordinary skill can readily determine and prescribe the effective amount of the drag required to prevent, counter or arrest the progress of the condition. Optimal precision in achieving concentrations of drag within the range that yields efficacy without toxicity requires a regimen based on the kinetics of the drug's availability to target sites. This involves a consideration of the distribution, equilibrium, and elimination of a drug.
In the methods of the present invention, the compounds herein described in detail can form the active ingredient, and are typically administered in admixture with suitable pharmaceutical diluents, excipients or carriers, which are collectively referred to herein as "carrier" materials, suitably selected with respect to the intended form of administration, that is, oral tablets, capsules, elixirs, syrups and the like, and consistent with conventional pharmaceutical practices.
For instance, for oral administration in the form of a tablet or capsule, the active drug component can be combined with an oral, non-toxic pharmaceutically acceptable inert carrier such as ethanol, glycerol, water and the like. Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents and coloring agents can also be incorporated into the mixture. Suitable binders include, without limitation, starch, gelatin, natural sugars such as glucose or beta-lactose, corn sweeteners, natural and synthetic gums such as acacia, tragacanth or sodium alginate, carboxymethylcellulose, polyethylene glycol, waxes and the like. Lubricants used in these dosage forms include, without limitation, sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride and the like. Disintegrators include, without limitation, starch, methyl cellulose, agar, bentonite, xanthum gum and the like.
For liquid forms the active drug component can be combined in suitably flavored suspending or dispersing agents such as the synthetic and natural gums, for example, tragacanth, acacia, methylcellulose and the like. Other dispersing agents which may be employed include glycerin and the like. For parenteral administration, sterile suspensions and solutions are desired. Isotonic preparations which generally contain suitable preservatives are employed when intravenous administration is desired.
Topical preparations containing the active drug component can be admixed with a variety of carrier materials well known in the art, such as, e.g., alcohols, aloe vera gel, allantoin, glycerine, vitamin A and E oils, mineral oil, PPG2 myristyl propionate, and the like, to form, e.g., alcoholic solutions, topical cleansers, cleansing creams, skin gels, skin lotions, and shampoos in cream or gel formulations.
The compounds of the present invention can also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamellar vesicles and multilamellar vesicles. Liposomes can be formed from a variety of phospholipids, such as cholesterol, stearylamine or phosphatidylcholines.
Compounds of the present invention may also be delivered by the use of monoclonal antibodies as individual carriers to which the compound molecules are coupled. The compounds of the present invention may also be coupled with soluble polymers as targetable drug carriers. Such polymers can include polyvinyl-pyrrolidone, pyran copolymer, polyhydroxypropylmethacryl-amidephenol, polyhydroxyethylaspartamidephenol, or polyethyl-eneoxidepolylysine substituted with palmitoyl residues. Furthermore, the compounds of the present invention may be coupled to a class of biodegradable polymers useful in achieving controlled release of a drug, for example, polylactic acid, polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals, polydihydro-pyrans, polycyanoacrylates and cross-linked or amphipathic block copolymers of hydrogels.
The following examples illustrate the present invention without, however, limiting the same thereto.
EXAMPLE 1
Purification Of The β Subunit Of High-Conductance Calcium-Activated Potassium Channels
Purified sarcolemmal membrane vesicles derived from bovine tracheal smooth muscle were prepared as previously described (Slaughter, R. S., Shevell, J. L., Felix, J. P., Garcia, M. L., and Kaczorowski, G. J., Biochemistry 28, 3995-4002 (1989)). The interaction of [ 125 I]ChTX (New England Nuclear Corporation) with maxi-K channels in bovine tracheal sarcolemmal membrane vesicles was monitored as outlined previously (Vazquez, J., Feigenbaum, P., Katz, G., King, V. F., Reuben, J. P., Roy-Contancin, L., Slaughter, R. S., Kaczorowski, G. J., and Garcia, M. L., J. Biol. Chem. 264, 20902-20909 (1989)). Binding of radiolabeled toxin to solubilized channels was measured by incubating aliquots of solubilized material in 0.05% digitonin with [ 125 I]ChTX as described (Garcia-Calvo, M., Vazquez, J., Smith, M., Kaczorowski, G. J., and Garcia, M. L. Biochemistry 30, 11157-11164 (1991)). At the end of the incubation period, protein was precipitated by addition of 10% (w/v) PEG (Mw˜8000) in the presence of δ-globulin and the precipitate was immediately collected onto GF/C glass fiber filters (Whatman) that had been presoaked in 0.5% polyethylenimine. Nonspecific binding was determined in the presence of 10 nM ChTX (Peninsula Laboratories). For each experiment, triplicate assays were routinely performed, and the data were averaged. The standard error of the mean of these replicates was typically less than 3%.
All buffers employed for solubilization and during purification contained 1 mM iodoacetamide, 0.1 mM PMSF, 0.1 mM benzamidine. Protein concentration was determined using either the Bradford (Bradford, M. M. (1976) Anal. Biochem. 72, 248-254) or the Gold (Stoschek, C. M. (1987) Anal. Biochem. 160, 301-305) method with bovine serum albumin as standard. Membranes derived from 250 cow tracheas (ca. 10 gr of purified sarcolemmal membrane vesicle protein) were solubilized with 0.5% digitonin for 10 min at 4° C., followed by centrifugation at 180,000×g for 50 min. The supernatant was removed and discarded. The remaining pellet was homogenized in 20 mM NaCl, 20 mM Tris-HCl, pH 7.4, 1% digitonin and the mixture was incubated at 4° C. for 10 min. Solubilized material was separated as indicated above. This process was repeated a total of five times.
The resulting supematants (S 2-6 ) were pooled, adjusted to 50 mM NaCl and loaded onto a DEAE-Sepharose CL6B column (500 ml of packed gel) equilibrated with 50 mM NaCl, 20 mM Tris-HCl, pH 7.4, 0.1% digitonin. Bound receptor was eluted batchwise with 170 mM NaCl, 20 mM Tris-HCl, pH 7.4, 0.1% digitonin. The eluted ChTX receptor was incubated overnight at 4° C. with 200 ml of WGA-Sepharose in 200 mM NaCl, 20 mM Tris-HCl, pH 7.4, 0.1% digitonin. The suspension was then placed in an empty column, and the fluid phase was collected until the WGA-Sepharose resin was packed. Unbound material was removed by washing with 10 bed volumes of equilibration buffer. Glycoproteins were biospecifically eluted with 200 mM N-acetyl-D-glucosamine in equilibration buffer. The eluate was dialyzed against 20 mM Tris-HCl, pH 7.4, 0.05% digitonin, concentrated 20-fold and adjusted with NaCl to a final concentration of 200 mM. Subsequently, the sample was applied in eight consecutive runs to a Mono Q HR10/10 (Pharmacia) ion exchange column equilibrated with 100 mM NaCl, 20 mM Tris-HCl, pH 7.4, 0.05% digitonin. A linear gradient was applied from 0.1 to 0.5M NaCl over 70 min at a flow rate of 2 ml/min. Fractions displaying ChTX binding activity, between 0.21 and 0.31M NaCl, were adjusted to 80 mM Na-phosphate, pH 7.0 and loaded onto a Bio-Gel HPHT (BioRad) 100×7.8 mm hydroxylapatite column, equilibrated with 80 mM Na-phosphate, pH 7.0, 10 mM NaCl, 0.05% digitonin. Bound material was eluted at a flow rate of 0.5 ml/min with a linear gradient from 80 to 160 mM Na-phosphate in 10 mM NaCl within 12 min, followed by a gradient from 160 mM Na-phosphate in 10 mM NaCl to 560 mM Na-phosphate, 70 mM NaCl within 10 min. Fractions containing ChTX binding activity eluted between 200 and 440 mM Na-phosphate.
The resulting fractions were dialyzed against 20 mM Tris-HCl, pH 7.4, 0.05% digitonin, concentrated, and separated on a continuous 7-25% (w/v) sucrose gradient. Active fractions were dialyzed against 20 mM Mes-NaOH, pH 6.2, 0.05% digitonin and loaded onto a Mono S HR5/5 (Pharmacia) ion exchange column, preequilibrated with the same buffer. Bound material was eluted with a linear gradient from 0 to 700 mM NaCl within 20 min at a flow rate of 0.5 ml/min. Fractions containing ChTX binding activity, which eluted between 120 and 260 mM NaCl, were dialyzed against 20 mM Tris-HCl, pH 7.4, 0.01% digitonin, concentrated to 0.3 ml and applied to another continuous sucrose gradient as described above. Using this purification scheme, the ChTX receptor was purified almost 2000-fold with recovery of 3.3% of the initial binding activity. Total recoveries at each individual step during purification are close to 100% indicating that no significant loss of activity occurs during the time involved in the purification procedures.
Fractions from the last sucrose density gradient centrifugation containing 31-158 ng of protein were dialyzed against 10 mM Na-borate, pH 9.0, 0.05% Triton X-100 and then reacted with 3.5 mCi of [ 125 I]Bolton-Hunter reagent (2200 Ci/mmol; New England Nuclear Corporation) for 15 min on ice. The reaction was quenched by addition of Tris-HCl, pH 7.4 to a final concentration of 100 mM. Covalent incorporation of [ 125 I]ChTX into the purified receptor was accomplished with the bifunctional reagent, disuccinimidyl subcrate as previously described for crosslinking ChTX to its receptor in membranes (Garcia-Calvo, M., Vazquez, J., Smith, M., Kaczorowski, G. J., and Garcia, M. L. (1991) Biochemistry 30, 11157-11164). Briefly, the purified receptor preparation was incubated with 130 pM [ 125 I]ChTX in 10 mM NaCl, 10 mM Taps-NaOH, pH 9.0, 0.1% digitonin, in the absence or presence of unlabeled ChTX, for two hours at room temperature. The solution was then adjusted to 0.2M NaCl and disuccinimidyl suberate was added to a final concentration of 0.18 mM. After incubation at room temperature for 1 min, the reaction was stopped by addition of Tris-HCl, pH 7.4 to a final concentration of 200 mM. Samples were dialyzed against 10 mM Tris-HCl, pH 7.4, 0.05% digitonin, concentrated 10 fold, and subjected to SDS-PAGE. Samples were resuspended into SDS-PAGE sample buffer containing 1% β-mercaptoethanol or 50 mM DTT and incubated at 37° C. for 120 min. Samples were subjected to SDS-PAGE using either continuous or discontinuous acrylamide gels (Laemmli, U. K. (1970) Nature 227, 680-685), and dried gels were exposed to Kodak XAR-5 film.
The purified ChTX receptor migrated in sucrose gradients as a large particle with an apparent sedimentation coefficient of 23S. When fractions from the sucrose gradient were subjected to SDS-PAGE, staining with silver revealed a single component with an apparent molecular weight of 62,000 that comigrated with [ 125 I]ChTX binding activity. A component of 31,000 was specifically labeled with [ 125 I]ChTX in the presence of disuccinimidyl suberate. Labeling of this protein is abolished s by agents such as IbTX, TEA and potassium that are known to inhibit ChTX binding to maxi-K channels. Since this component is heavily glycosylated, it does not stain well by conventional protein staining techniques. Therefore, fractions from the sucrose gradient were labeled with [ 125 I]Bolton-Hunter reagent, subjected to SDS-PAGE and analyzed by autoradiography. From the distribution of [ 125 I]Bolton-Hunter labeled polypeptides, it is evident that ChTX binding activity correlates with the presence of two subunits, α and β of 62,000 and 31,000 apparent molecular weights.
The relationship between the β subunit identified after s Bolton-Hunter labeling of the purified preparation and the component labeled with [ 125 I]ChTX in crosslinking experiments was further examined. Deglycosylation experiments were carded out with both preparations. Samples were dialyzed for 12 hours at 4° C. against 5 mM Tris-HCl, pH 7.4, 0.05% digitonin and denatured by heating for 5 min at 65° C. in the presence of 0.5% SDS, 50 mM β-mercaptoethanol. Samples were adjusted to 1.3% Nonident P-40 (w/v), and deglycosylation was started by addition of 1 IU recombinant N-glyconase F (Genzyme). After incubation at 37° C. for different periods of time, the reaction was stopped by addition of boiling SDS sample buffer, samples were subjected to SDS-PAGE and dried gels were exposed to Kodak XAR-5 fill. Recombinant N-glycanase caused a time-dependent conversion of the [ 125 I]ChTX crosslinked protein (apparent molecular weight of 35,000; 31 kDa for the core protein plus 4.4 kDa contributed by the radiolabeled toxin) into an intermediate form of 28.9 kDa and a final product of 25.6 kDa. These experiments indicate that this protein is heavily glycosylated, most probably at two different glycosylation sites by N-linked sugars. The same experiment was repeated with purified [ 125 I]Bolton-Hunter labeled receptor. The β subunit displayed an identical time-course of deglycosylation to that of the [ 125 I]ChTX crosslinked protein. The apparent molecular weight of the deglycosylated [ 125 I]Bolton-Hunter labeled core protein was determined independently by Ferguson plot analysis (Frank, R. N., and Rodbard, D. (1975) Arch. Biochem. Biophys. 171, 1-13) to be 21.4 kDa. This molecular weight is in good agreement with the value obtained after deglycosylation of the [ 125 I]ChTX labeled subunit if 4.4 kDa contributed by the radiolabeled toxin is subtracted from the mass of the final product.
EXAMPLE 2
Sequencing Peptides Derived From The Purified β Subunit
Fractions from the final sucrose density gradient centrifugation of the ChTX receptor purification, containing ˜31 pmoles of [ 125 I]ChTX binding sites, were dialyzed against 10 mM sodium borate, pH 8.8, 0.05% Triton X-100, and reacted with 50 μCi [ 125 I]Bolton-Hunter labeling reagent (2200 Ci/mmol) for 15 min on ice. The iodinated sample was separated by electrophoresis on a 12% SDS-polyacrylamide gel and the wet gel exposed for 30 min to Kodak XAR film. The area of radioactivity corresponding to the location of the β subunit (and a control area) were cut from the gel and electroeluted for 12 hours in 0.1M ammonium acetate, 0.1% SDS. The sample was dialyzed against 40 mM sodium phosphate, pH 7.8, 0.02% SDS for 24 hours, concentrated 5 fold, and then incubated with 5 μg of V 8 endoproteinase Glu-C (final concentration of 100 μg/ml) for 14 hours at room temperature. The digested β subunit was loaded onto a Vydac C 4 column (RP-300, 5 μm, 150×2.1 mm), equilibrated with 2% acetonitrile and 10 mM TFA, using an ABI 130A separation system. Elution was achieved in the presence of a linear gradient from 2-99% acetonitrile at a flow rate of 50 μL/min. The collected peptides were loaded onto Porton peptide filter supports and subjected to automated Edman degradation employing an integrated micro-sequencing system (Porton Instruments PI2090E) with an on-line detection system. The sequence of a 28 amino acid peptide derived from the β subunit was obtained using these procedures. The sequence is as follows:
GKKLVMAQCLGETRALCLGVAMVVGAVI
EXAMPLE 3
Molecular Cloning Of The β Subunit
Based on the sequence obtained from the β subunit, degenerate oligonucleotides encoding amino acid residues 2-7 and 20-24 of the peptide were synthesized and used as primers in PCR. cDNA was synthesized from bovine tracheal smooth muscle poly A+mRNA (using the degenerate oligo encoding residues 20-24 as the primer) and this cDNA was used as the template in the PCR. [α- 32 P]dATP (100 μCi/ml) was added to the reaction to label the products and the solution was cycled 25 times at 94° C., 37° C., and 72° C. for 1, 2, and 3 min, respectively. The amplified product was fractionated on a 6% DNA sequencing gel and the region of the gel surrounding the cDNA of the expected length (from 82-92 bp; based on the peptide sequence) was excised. The DNA was eluted into 0.5 ml H 2 O (22° C., 60 min) and 30 μl of the eluted cDNA were reamplified using 50 cycles of the PCR as described above, but without [ 32 P]dATP. The product of this PCR reaction was cloned and sequenced by standard techniques. An unambiguous 41 bp fragment encoding the peptide sequence MAQRRGETRALCLG was thereby determined. An oligonucleotide probe encoding these 41 bp was constructed, labeled (>10 8 cpm/pmol), and used to probe Northern blots and screen cDNA libraries.
A λgt10 cDNA library was constructed from bovine aortic smooth muscle poly (A+) mRNA and screened with the 41 bp oligonucleotide probe. Viruses were plated on E. coli C600 hfl at a density of 40,000 pfu/135 mm plate. After plaque formation, phage from 36 plates were transferred to Hybond-N filters and hybridized to the probe (2 pmole) overnight at 42° C. in a buffer containing 5× saline/sodium phosphate/EDTA, 0.5% SDS, 5× Denhardt's solution. Filters were washed to a final stringency of 0.1× SSC/0.1% SDS at 65° C. Five phage containing cDNAs that hybridized to the probe were isolated in this manner. The cDNA from each was excised from the viral DNA by digestion with Not I and subcloned into pKSII+. The longest was sequenced on both strands by the dideoxynucleotide termination method. A bovine tracheal cDNA encoding the β subunit was subsequently isolated by PCR using primers derived from the sequence of the aortic cDNA clone and bovine tracheal cDNA as the template. The nucleotide sequences of the cDNAs from both tissues were identical. Northern blot analysis of poly A+mRNAs, isolated from either bovine tracheal or aortic smooth muscles, demonstrated that the cDNA hybridized to mRNAs of the same sizes in each tissue. Thus, strong hybridization to a transcript of ˜3.8 kb and weaker hybridization to one of ˜1.7 kb was observed in blots of RNAs from both tissues. The pattern of hybridization was identical in blots probed with a cDNA encoding the entire open reading frame of the protein or with a 41 bp oligonucleotide encoding only amino acids 7-20 in the sequence.
The cDNAs encode a protein of 191 amino acids with a molecular weight of 21,957 Da, consistent with the size of the deglycosylated protein in purified preparations of the channel. The deduced sequence of the protein is unique, bearing little sequence or structural homology to subunits of other known ion channels. Hydropathy analysis demonstrated the presence of two hydrophobic, putative transmembrane, domains in the protein. There are three potential sites for N-linked glycosylation and one consensus sequence for phosphorylation by protein kinase A. With the absence of a canonical signal sequence and the presence of two strongly hydrophobic regions, it is likely that the protein has intracellular amino and carboxy termini and one large extracellular domain. This topology would place two of the potential N-glycosylafion sites in the extracellular space, consistent with biochemical evidence suggesting the presence of two N-linked sugar moieties attached to the protein. Furthermore, in this orientation, the cAMP-dependent protein kinase recognition sequence would be located in the cytoplasm, also consistent with published reports of PKA modulation tion of maxi-K currents (Reinhart, P. H., Chung, S., Martin, B. L., Brautigan, D. L., and Levitan, I. B. (1991) J. Neurosci. 11, 1627-35; Chung, S. K., Reinhart, P. H., Martin, B. L., Brautigan, D., and Levitan, I. B. (1991) Science 253, 560-62). There are three Lys residues in the putative extracellular domain. One (or more) of these residues is expected to be the site for covalent attachment of [ 125 I]ChTX in the presence of the bifunctional crosslinking reagent, disuccmimidyl suberate. The peptide sequence, determined from a fragment derived from an S. aureus V 8 protease digestion, begins at Gly 2 in the deduced sequence. Since this enzyme cleaves proteins specifically after Glu or Asp residues, and in the sequence deduced from the cDNA, Gly 2 follows the putative initiator Met residue, the amino terminus of the protein may be processed post-translationally to remove the methionine. The overall structure of the protein deduced from the cDNA sequence corresponds well to the biochemical properties of the purified protein which strongly supports the idea that it represents the β subunit of the maxi-K channel.
EXAMPLE 4
Production Of Antibodies Against The β Subunit
Site-directed rabbit antisera were produced against two domains of the putative extracellular loop of the β subunit protein using techniques described previously (Knaus H.-G., Garcia-Calvo, M., Kaczorowski, G. J., and Garcia, M. L. (1994) J. Biol. Chem 269, 3921-3924). The sequences of these peptides are DQEELEGKRVPQYP (anti-β 61-75 ) and ADVEKVRARFHENQD (anti-β 118-132 ). For all immunoprecipitation studies, anti-β antibodies were prebound to Protein-A Sepharose 4B as described (Knaus H.-G., Garcia-Cairo, M., Kaczorowski, G. J., and Garcia, M. L. (1994) J. Biol. Chem 269, 3921-3924). The gel was washed three times with 1 mL of RIA buffer (150 mM NaCl, 20 mM Tris-HCl, pH 7.4, 1% Triton X-100, 1 mg/ml bovine serum albumin) before the addition of either the isolated [ 125 I]Bolton-Hunter labelled β subunit, the [ 125 I]ChTX-crosslinked β subunit, or the 125 I-labelled, native maxi-K channel complex (containing both the α and β subunits). In all preparations that had been denatured by boiling in SDS in the presence of β-mercaptoethanol, the final SDS concentration was never allowed to exceed 0.05%. The immunoprecipitated samples were analyzed by SDS-PAGE after denaturation of the resin for 15 min at 56° C. in SDS sample buffer containing 1% β-mercaptoethanol. Gels were dried and exposed to Kodak XAR film at -80° C.
Under denaturing conditions, the site-directed antibodies raised against two putative extracellular epitopes of the β subunit specifically immunoprecipitated the [ 125 I]Bolton-Hunter labelled β subunit, as well as the [1 25I]ChTX crosslinked β subunit. In addition, these sera recognized the 31 kDa protein on Westem blots of purified maxi-K channel preparations. Immunoreactivity paralleled ChTX binding throughout the fractions of the last sucrose density gradient in the purification procedure. Under nondenaturing conditions, however, these anti-β sera immunoprecipitated both the α and β subunits of the channel. These data provide independent immunological evidence that the protein encoded by the cDNA does, in fact, represent the β subunit of the maxi-K channel and that, in vivo, the channel exists as a tight complex of both the α and β subunits.
EXAMPLE 5
Coexpression Of The β-Subunit With The α-Subunit
cDNAs encoding both the α and β subunits were used as templates for the production of cRNA. The α subunit cDNA was obtained from Leo Pallanck (Univ. of Wisconsin) and consisted of a full-length mouse brain cDNA (mslo 19; GenBank Accession #U09383) in an RNA transcription vector, pGH. The mslo 19 cDNA was cloned by hybridization using a fragment of the Drosophila slowpoke cDNA, and is nearly identical to a published sequence, mbr5, encoding a large conductance, Ca 2+ -activated potassium channel α subunit (A. Butler, S. Tsunoda, D. P. McCobb, A. Wei, and L. Salkoff, Science 261:221-224), and probably represents a splice variant from the same gene. cRNA transcribed from the mslol 9 cDNA did not produce potassium channels in Xenopus oocytes. We therefore used standard techniques to modify the mslo 19 cDNA, specifically by deleting the 5' non-coding sequence (bases 1 to 940), and replacing that sequence with a consensus eukaryotic translation initiation sequence: 5'-GCCGCCACC-3'. This modified construct (mslo1 9Δ5'UTR) contained the identical open reading frame as the original mslo19 cDNA and proved to be a good template for production of cRNA encoding the α-subunit of a large-conductance, calcium activated potassium channel, as explained below. A fragment of the β subunit cDNA, including the entire open reading frame, was subcloned into a pGEM (Promega, inc.) vector for cRNA transcription. The cRNAs encoding both the α and β subunits were transcribed using the appropriate RNA polymerase as determined by the transcription vector (T7 for α, and SP6 for β) and capped in vitro using a kit (mCAP; Stratagene, inc), purified by size-exclusion chromatography using sepahadex G-50 spin colms (Bio-Rad, inc.), and analyzed for purity and length by agarose/formaldehyde gel electrophoresis according to established procedures. Following ethanol precipitation, cRNAs were resuspended in sterile, DEPC-treated water at a concentration of 0.1 to 1 μg/μl, and stored in 2 μl aliquots at -8° C.
Injection of mRNA or cRNA into Xenopus oocytes was done by a modification of established protocols (A. Coleman, Transcription and Translation: A Practical Approach. B. D. Hanes, S. J. Higgins, Eds., 1984); Y. Masu, et al., Nature 329, 836-838 (1987)). Oocytes were surgically removed from 0.17% tricaine anesthetized Xenopus laevis (Xenopus One). The excised ovarian lobes were teased apart with jeweler's forceps and then placed into OR-2 (82.5 mM NaCl, 2 mM KCl, 1 mM MgCl 2 , 5 mM HEPES, pH 7.4) containing 2 mg/ml collagenase β (Boehringer Mannhiem) for 2 hours at room temperature with a change of the buffer at 1 hour. Isolated oocytes were repeatedly washed in OR-2 until the supernatant remained clear. Stage 5 and 6 oocytes were selected and cultured overnight in supplemented OR-2 (OR-2 containing 1.8 mM CaCl 2 and 0.5 mg/ml gentamycin. Oocytes were injected with 46 nl of RNA at a concentration of 0.1 to 1.0 mg/ml in H 2 O. RNA was injected using a Nanoject automatic oocyte injector (Drummond Scientific) and injection needles were pulled from 3.5" Drummond capillaries using a Micropipette puller (Kopf Instruments).
Currents were recorded from Xenopus oocytes using two-electrode voltage-clamp methods to record currents from the entire oocyte and patch-clamp methods to record current from small patches of membrane excised from the oocytes. Recordings were done at room temperature and were performed 1 to 30 days after injection.
Oocytes having been previously injected with cRNAS encoding either α-subunit or β-subunit or both subunits together, were transferred to a plastic recording chamber by means of a fire-polished pasteur pipet. The chamber contained ND-96 saline (96 mM NaCl, 5 mM KCl, 1 mM MgCl 2 , 1.8 mM CaCl 2 , 10 mM Na-HEPES, pH 7.3). Microelectrodes having resistances of 0.2 to 1 Mohm when filled with 1M KCl were fashioned using a Narashige pipete puller from DAGAN LE-16 glass capillary tubes. KCl-filled electrodes were attached using the manufacturer's -supplied holders to a DAGAN CA-1 oocyte voltage clamp. Using appropriate micromanipulators, and following procedures as outlined in the operator's manual for the CA-1 voltage clamp, the oocyte was impaled by two electrodes, and recordings of membrane currents were obtained from the oocytes expressing either α-subunit or β-subunit or both subunits together. Recordings were obtained at room temperature. Stimulus protocols, in the form of rectangular voltage pulses, or voltage ramps, were presented to the voltage-clamped oocyte with the aid of a computer-based data acquisition system (PClamp; Axon Instruments), and the currents so elicited were stored as electronic data files for subsequent retrieval and analysis.
Patch clamp recordings were made from membrane patches excised from Xenopus oocytes that had their vitilin membranes removed using ccinventional techniques (Hamill, O. P., Marty, A., Neher, E., Sakmann, B., and Sigworth F. J. Pfluegers Arch. 391, 85-100 (1991)) at room temperature. Glass capillary tubing (Garner #7052) was pulled in two stages to yield micropipettes with tip diameters of approximately 1-2 microns. Pipettes were typically filled with solutions containing (Mm): 150 KCl, 10 Hepes (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid), 0.01 Ca, and adjusted to pH 7.20 with 3.7 mM KOH. After forming a high resistance (>10 9 ohms) seal between the plasma membrane and the pipette, the pipette was withdrawn from the cell forming an excised inside-out membrane patch. The patch was excised into a bath solution containing (mM): 150 KCl, 10 Hepes, 0.001 to 0.1 Ca, and the pH was adjusted to 7.2 with 3.7 KOH. An Axopatch 1C amplifier (Axon Instruments, Foster City, Calif.) with a CV-4 headstage or a List EPC-7 amplifier was used to control the voltage and to measure the currents flowing across the membrane patch. The input to the headstage was connected to the pipette solution with a Ag/AgCl wire, and the amplifier ground was connected to the bath solution with a Ag/AgCl wire via a bridge containing agar dissolved in 0.2M KCl. Maxi-K channels were identified by their large single channel conductance (>200 pS) and sensitivity of channel open probability to membrane potential and intracellular calcium concentration.
Data were stored on a Racal store 4DS FM tape recorder (Racal Recorders, Vienna, Va.) or on digital video tape using a video casette recorder after digitizing the signal with VR-10 (Instrutech Corp., Belmont N.Y.) PCM video encoder. For quantitative analysis, the data were played into a DEC 11-73 (Digital Equipment Corp., Maynard, Mass.) after digitization with a DT2782-8D1A analogue to digital converter (Data Translation Inc., Marlboro, Mass.), or played into a Mac IIx or Quadra 700 or Quadra 950 computer (Apple Computers) after digitization with an ITC-16 interface (Instrutech Corp., Belmont, N.Y.).
Oocytes injected with cRNA encoding the β subunit alone exhibited no measurable potassium currents different from currents seen in control, uninjected oocytes using both the whole-oocyte and patch-clamp recording techniques. Oocytes injected with cRNA encoding the α subunit alone exhibited large (>5 μA) outward currents in whole-oocyte voltage-clamp experiments that were activated at positive membrane potentials. These outward currents were blocked by ChTX and IbTX at 10 to 30 nM. Patch-clamp recordings were made from excised, inside-out membrane patches obtained from these oocytes. In patches with a low density of channels (1-10 channels per patch), individual maxi-K channels could be distinguished with a large single-channel conductance (>200 pS). The open probability of these channels was increased by increasing the intracellular concentration of calcium or by increasing the membrane potential. When the density of channels in the oocytes increased, and the patches contained many channels (>50), then the steps in current due to opening and closing of individual channels could not be distinguished. Since these patches contained many channels, the stochastic variations in open probability of individual channels was averaged out, and accurate measures of the effects of intracellular calcium, membrane potential and drugs could be obtained from each individual patch. In these macroscopic patch recordings, channel open probability was determined from patch conductance, and increased smoothly as a function of membrane potential until the maximal conductance was achieved. Channel open probability showed an e-fold increase per 15-25 mV increase in membrane potential. The midpoint of the conductance-voltage curves was shifted in the hyperpolarizing direction by increasing intracellular calcium concentrations. The currents flowing through these channels was selective for potassium over sodium or chloride because no appreciable outward currents were observed when the intracellular solution was changed from 150 mM KCl to 150 mM NaCl. The currents in these patches were not increased by 100-500 nM of dehydrosoyasaponin I (DHS-I), a potent activator of maxi-K channels in some smooth muscle tissues (McManus O. B., Harris, G. H., Giangiacomo, K. M., Feigenbaum, P., Reuben, J. P., Addy, M. E., Burka, J. F., Kaczorowski, G. J., and Garcia, M. L. Biochemistry 32, 6128-33 (1993).
Oocytes injected with cRNAs encoding both the α and β subunits exhibited outward potassium currents in two-electrode voltage clamp recordings of the entire oocyte that were blocked by ChTX and IbTX. The magnitudes of currents recorded from oocytes that were injected with cRNAs encoding both the α and β subunits were similar to the currents observed in oocytes injected with cRNA encoding the α subunit alone. The outward currents observed in the oocytes injected with α and β subunits were activatea at more negative potentials than the oocytes injected with α subunit cRNA alone. Direct evidence for a difference in channel gating between channels in oocytes injected with cRNA encoding α subunit alone and channels in oocytes injected with cRNAs encoding both the α and β subunits comes from recordings of currents in membrane patches excised (inside-out configuration) from each type of oocyte. Maxi-K channels observed in α and β subunit-injected oocytes had a large single channel conductance (>200 pS), and these channels were selective for potassium over sodium. The open probability of these channels was increased by increasing intracellular calcium concentrations and by membrane depolarization. The gating of the channels in oocytes injected with both α and β subunit cRNAs differed from the gating of channels from oocytes injected with α subunit cRNA alone. The channels from oocytes expressing both subunits were activated at more negative membrane potentials than were channels expressing the α subunit alone. At a given concentration of intracellular calcium, channels from oocytes expressing both subunits were activated at membrane potentials 50 to 100 mV more negative than were channels from oocytes expressing the α subunit alone. The shift in the voltage-dependence of gating of channels due to coexpression of the β subunit was similar to the shift in voltage-dependence of channel gating that occurs after a ten-fold increase in intracellular calcium concentration. Channels from oocytes expressing both subunits were fully activated by 100-300 nM of DHS-I applied to the intracellular face of the channel. Thus, addition of the β subunit shifted the voltage-dependence of gating of channels encoded by the α subunit, and conferred sensitivity to an activator of maxi-K channels. Therefore, the β subunit co-assembles with the α subunit and forms calcium-activated potassium channels with pharmacological and biophysical properties that differ from calcium-activated potassium channels encoded by the a subunit alone.
EXAMPLE 6
CLONING OF β SUBUNIT cDNA INTO VECTORS FOR EXPRESSION IN INSECT CELLS
Baculovirus vectors, which are derived from the genome of the AcNPV virus, are designed to provide high level expression of cDNA in the Sf9 line of insect cells (ATCC CRL#1711). Recombinant baculoviruses expressing β subunit cDNA is produced by the following standard methods (In Vitrogen Maxbac Manual): the β subunit cDNA constructs are ligated into the polyhedrin gene in a variety of baculovirus transfer vectors, including the pAC360 and the BlueBac vector (In Vitrogen). Recombinant baculoviruses are generated by homologous recombination following co-transfection of the baculovirus transfer vector and linearized AcNPV genomic DNA [Kitts, P. A., Nuc. Acid. Res. 18, 5667 (1990)] into Sf9 cells that may also be expressing the α subunit. Recombinant pAC360 viruses are identified by the absence of inclusion bodies in infected cells and recombinant pBlueBac viruses are identified on the basis of β-galactosidase expression (Summers, M. D. and Smith, G. E., Texas Agriculture Exp. Station Bulletin No. 1555). Following plaque purification, β subunit expression is measured by the assays described herein.
The cDNA encoding the entire open reading frame for β subunit is inserted into the BamHI site of pBlueBacII. Constructs in the positive orientation are identified by sequence analysis and used to transfect Sf9 cells that may also be expressing the α subunit in the presence of linear AcNPV wild type DNA.
Authentic, active β subunit is found in association with the infected cells. Active β subunit or α-β heteromultimers are extracted from infected cells by hypotonic or detergent lysis.
Alternatively, the human β subunit receptor is expressed in the Drosophila Schneider 2 cell line that may also be expressing the α subunit by cotransfection of the Schneider 2 cells with a vector containing the β subunit DNA downstream and under control of an inducible metallothionin promoter, and a vector encoding the G418 resistant neomycin gene. Following growth in the presence of G418, resistant cells are obtained and induced to express β subunit by the addition of CuSO 4 . Identification of modulators of the β subunit or the maxi-K channel is accomplished by assays using either whole cells or membrane preparations.
EXAMPLE 7
CLONING OF β SUBUNIT cDNA INTO A YEAST EXPRESSION VECTOR
Recombinant β subunit is produced in the yeast S. cerevisiae that may also be expressing the α subunit following the insertion of the optimal β subunit cDNA cistron into expression vectors designed to direct the intracellular or extracellular expression of heterologous proteins. In the case of intracellular expression, vectors such as EmBLyex4 or the like are ligated to the β subunit cistron [Rinas, U. et al., Biotechnology 8, 543-545 (1990); Horowitz B. et al., J. Biol. Chem. 265, 4189-4192 (1989)]. For extracellular expression, the β subunit cistron is ligated into yeast expression vectors which fuse a secretion signal. The levels of expressed β subunit or maxi-K channels are determined by the assays described herein.
EXAMPLE 8
PURIFICATION OF RECOMBINANT β SUBUNIT AND α-β HETEROMULTIMERS
Recombinantly produced β subunit or maxi-K channels may be purified by antibody affinity chromatography.
β subunit antibody affinity columns are made by adding the anti-β subunit antibodies to Affigel-10 (Biorad), a gel support which is pre-activated with N-hydroxysuccinimide esters such that the antibodies form covalent linkages with the agarose gel bead support. The antibodies are then coupled to the gel via amide bonds with the spacer arm. The remaining activated esters are then quenched with 1M ethanolamine HCl (pH 8). The column is washed with water followed by 0.23M glycine HCl (pH 2.6) to remove any non-conjugated antibody or extraneous protein. The column is then equilibrated in phosphate buffered saline (pH 7.3) together with appropriate membrane solubilizing agents such as detergents (e.g., 0.1% digitonin) and the cell culture supernatantss or cell extracts containing solubilized β subunit or the α- β subunit heteromultimer are slowly passed through the column. The column is then washed with phosphate-buffered saline together with detergents until the optical density (A280) falls to background, then the protein is eluted with 0.23M glycine-HCl (pH 2.6) together with detergents. The purified β subunit protein or maxi-K channel is then dialyzed against phosphate buffered saline containing appropriate detergents.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 4(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 2238 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:GCAGCCTCTTTTGGGTGGGGGCTGGGGACCAGGAAGAAAAGGGTCTGCCGAAGACTCGCA60GGGCACCCAGGAGACTAAACGTCTGCTGTCCCCAGTGGCCATGGGAAAGAAGCTGGTGAT120GGCCCAGAGGCGGGGAGAGACTCGGGCCCTCTGCCTGGGGGTGGCCATGGTCGTGGGCGC180CGTCATCACCTACTACATCTTAGGCACAACTGTGCTGCCCCTCTATCAGAAGAGTGTGTG240GACCCAGGAATCCACGTGTCACCTGATTGAGACCAACATCAGGGACCAGGAGGAGCTGGA300GGGCAAGAGGGTGCCCCAGTACCCATGCCTGTGGGTCAACGTGTCGTCCGTGGGCCGCTG360GGCTGTGCTGTACCACACGGAGGACACGCGGGACCAGAACCACCAGTGCTCCTACATCCC420AAGCAGCCTGGACAACTACCAAGTGGCCCGGGCCGACGTGGAGAAGGTCAGAGCCAGGTT480CCACGAGAACCAGGATTTCTTCTGCTTCTCCACGACTCGGGAGAATGAGACCAGCGTCCT540GTACCGGCGCCTCTATGGGCCCCAGAGCCTCCTCTTCTCTCTCTTCTGGCCCACCTTTCT600GCTGACTGGCGGCCTGCTCATCATTGTCATGGTGAAGATCAACCAGTCCCTGTCCATCCT660GGCGGCCCAGAGGTAGATCCACACACTCCCATCACCTCTCGGGCCGCTCTCGCTCGTGTC720CCGTGCCCCTCTCCTGCCTTCGCCCCTCCCCCTCCACTGCACGGATGGTCTTTGGGAAAT780CCCTTAGTTAAGTCATTTCCTGCTCAAGACTGTTCAATGGCTCCTCAGGACCCAGGAGAA840CTGAAGGTCAACCCGTGATGGTTCTCCATCCTGGACCCCACTCAGTCCATCCATCTGAGT900CAGTCCATCCCTGACTCAAATCTGTTTTCTGCTGTTCCACTGTCCACTGGACTGATGCCA960ATGAGTCTCACTTCTGTGCCTGCTGGGCCCTCCCAGGAAGTGCTCCCCAACAAGCCTCCA1020TTCCTTCTTGGAATTCCAAAGTGAAAATAGCAGCAGCCCCATAGACACAGCACATTCATC1080AGTGGGACATCGCTTGTTTTCAGCTTTCTCAGCTCCGTATACTTCTTATACCGAATATTA1140ACAAATATAGTACAAACTTCTGGTCTTGAAGTCATGGGGATATAACTGCAACATGGTGAC1200AATAATTAGTAATACTTTGCTGCATATTTGAAAGTTGCTGAGAGAGTAGATCTTAAAAGC1260TCTCATCATAAGAAAAAAAACTGTCACTGTATATGAGATGGGTGTTAACTAGAAACTGTT1320GTGGTGATGATTTTGTAATACATACAGATATTGAATAATTTTGTTACACACTTGAAAACT1380AATATAATCTTATATATTGATTATATCTCAAGAAACCAAATATATACACAATATATAGGC1440TATAAGGAAATGATACTAACATACATAAAAAACATTAACAGTGGGATTTATTAATTGTAA1500TTTTCTTCCTTCCTTTNATTTTTGTACTTTTCTAAATTTTCAATAATAGAAAGGCTTGGT1560TTCACTGTGTTTATTTTTAATCAGAACAGTAACAACAGATGTAATTTTGGAAAAATGTTT1620GAAGGGGTAGGCTCCCCATCATCAAGGCAGATGGAAGTCGCCTAGTGGACAGGTTGAACT1680CCAATCAGACACAGGCTTTTTTTTTTTAATATTTATTTTTAATCGGCGGATAATCGCTTT1740ACAGTGTTGCGTTGGTTTCTGCCATACAGCACCATGAATCGGCCACGGGTACACCTAAGA1800CACGGACTTGTGAGAACACACAAGTTTAAGAATCCTGGACAGAGGGAAAGTAAACACAGA1860TGGGGATTCATGGTTTTCAGTGTAGATTAAATACAAGGTACCTGGGCCTGCCCTGGCGGT1920TCAGTGGTTCAGCAAGTGGTGAAGCAATGTCAAAGCAGGAGACACAGTTCCTGATCCCTG1980GTATGTGAAGGTTCCTTATGCGCTGAGCAACCGAACCTGTTCACCACAACCACTGAGGCC2040GCCTTCTAGAGCCCACAAGCCAGAACCGCTGAGCCCAGGTGCTGGAGCCGGTGCTCACAC2100CCAGAGAAGCCACTGCAACGAGAAGCCCACGCGCAGTGCCGGGGAGTAGCCTCCACTCGT2160TACACCCAAAGACGTCCCCACACAGAGACGAAGACCCAGGCGGCCGCTCTAGAACTAGTG2220GATCCCCCGGGCTGCAGG2238(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 191 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: unknown(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:MetGlyLysLysLeuValMetAlaGlnArgArgGlyGluThrArgAla151015LeuCysLeuGlyValAlaMetValValGlyAlaValIleThrTyrTyr202530IleLeuGlyThrThrValLeuProLeuTyrGlnLysSerValTrpThr354045GlnGluSerThrCysHisLeuIleGluThrAsnIleArgAspGlnGlu505560GluLeuGluGlyLysArgValProGlnTyrProCysLeuTrpValAsn65707580ValSerSerValGlyArgTrpAlaValLeuTyrHisThrGluAspThr859095ArgAspGlnAsnHisGlnCysSerTyrIleProSerSerLeuAspAsn100105110TyrGlnValAlaArgAlaAspValGluLysValArgAlaArgPheHis115120125GluAsnGlnAspPhePheCysPheSerThrThrArgGluAsnGluThr130135140SerValLeuTyrArgArgLeuTyrGlyProGlnSerLeuLeuPheSer145150155160LeuPheTrpProThrPheLeuLeuThrGlyGlyLeuLeuIleIleVal165170175MetValLysIleAsnGlnSerLeuSerIleLeuAlaAlaGlnArg180185190(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1106 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:GAATTCCGGCTCTTTTGGGGTGGGGGCGGGGGTCCAGGCAGAAAGAAACCGTCTGCTGCT60CAAGACCCACAGGACGCCGGGAAGACTAAATGATCACTGCCCCCAGTGAATATGGTGAAG120AAGCTGGTGATGGCCCAGAAGCGGGGAGAGACACGAGCCCTTTGCCTGGGTGTAACCATG180GTGGTGTGTGCCGTCATCACCTACTACATCCTGGTCACGACTGTGCTGCCCCTCTACCAG240AAAAGCGTGTGGACCCAGGAATCCAAGTGCCACCTGATTGAGACCAACATCAGGGACCAG300GAGGAGCTGAAGGGCAAGAAGGTGCCCCAGTACCCATGCCTGTGGGTCAACGTGTCAGCT360GCCGGCAGGTGGGCTGTGCTGTACCACACGGAGGACACTCGGGACCAGAACCAGCAGTGC420TCCTACATCCCAGGCAGCGTGGACAATTACCAGACGGCCCGGGCCGACGTGGAGAAGGTC480AGAGCCAAATTCCAAGAGCAGCAGGTCTTCTACTGCTTCTCCGCACCTCGGGGGAACGAA540ACCAGCGTCCTATTCCAGCGCCTCTACGGGCCCCAGGCCCTCCTCTTCTCCCTCTTCTGG600CCCACCTTCCTGCTGACCGGTGGCCTCCTCATTATCGCCATGGTGAAGAGCAACCAGTAC660CTGTCCATCCTGGCGGCCCAGAAGTAGAGCCATCCATCCATGCCATACCACTTGTCAGGG720CACAGGGGACTGGCTGGGCCCCCAGGGCTGCTCCCCACTTGCAGCACAATGCCTTCTCCA780CCTGCCCTCCCACTCTTCCAGTCCAATCCACGCTGTCTTCTGTTGCAGGACTAACCTTTG840AGAAATCCTTTTGTGAAGTCATTGCCTGCTCGAAGAATGTACAGTGGCTCCCCAATGCCT900TGGAGCCATAAGGCCAGCCAGTTCTAGCTCTCTATTACCTGTCCCCACTCAACTGACTCA960TACCTGTTTCCGGCTGCATCACTATGTGCCCCACAGAGAACGATGATCGTCACCTCTGTG1020CCTGAGTTCTCCCTGTTGTCTCAAAGCGGTACCCATCCTCCCCCAGAAGCTGTCCCCAGC1080GAGCCTCCCTTCTTTGTTTGAATTCC1106(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 191 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: unknown(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:MetValLysLysLeuValMetAlaGlnLysArgGlyGluThrArgAla151015LeuCysLeuGlyValThrMetValValCysAlaValIleThrTyrTyr202530IleLeuValThrThrValLeuProLeuTyrGlnLysSerValTrpThr354045GlnGluSerLysCysHisLeuIleGluThrAsnIleArgAspGlnGlu505560GluLeuLysGlyLysLysValProGlnTyrProCysLeuTrpValAsn65707580ValSerAlaAlaGlyArgTrpAlaValLeuTyrHisThrGluAspThr859095ArgAspGlnAsnGlnGlnCysSerTyrIleProGlySerValAspAsn100105110TyrGlnThrAlaArgAlaAspValGluLysValArgAlaLysPheGln115120125GluGlnGlnValPheTyrCysPheSerAlaProArgGlyAsnGluThr130135140SerValLeuPheGlnArgLeuTyrGlyProGlnAlaLeuLeuPheSer145150155160LeuPheTrpProThrPheLeuLeuThrGlyGlyLeuLeuIleIleAla165170175MetValLysSerAsnGlnTyrLeuSerIleLeuAlaAlaGlnLys180185190__________________________________________________________________________
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Disclosed are nucleic acids encoding the β subunit of the mammalian large-conductance ("maxi-K") potassium channel, cells transformed with such nucleic acids, and β subunit proteins produced by the transformed cells. Within the invention are recombinant host cells expressing αβ heteromultimers. Such cells or preparations made from them may be used to screen for pharmacologically active modulators of maxi-K channel activity. Such modulators are potentially useful in treating asthma, pregnant human myometrium, hypertension and angina, cerebral ischemia, and conditions where stimulation of neurotransmitter release is desired, such as in Alzheimer's disease and stimulation of damaged nerves.
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BACKGROUND
The disclosure herein generally relates to enhancing software application performance within a given hardware and operating system environment.
Interrupt-driven processors frequently execute code at different privilege levels, the different privilege levels conveying different permissions to perform operations. For example, the executable code of an operating system, such as the code for the operating system kernel, is typically run at a higher privilege level than the code of ordinary application programs. In this environment, application code or other code running at a lower privilege level may lack sufficient permissions to perform certain operations, such as writing to particular areas of memory (e.g., writing to memory of the network stack for sending a packet). In consequence, the application code must communicate a request to the code of a high privilege level, such as the operating system kernel code, to perform the operation on its behalf. In order to maintain security, the request must typically be made through some form of gate mechanism—such as an interrupt, or a system call resulting in a software interrupt—that causes a hardware protection check of the operation to ensure that it does not violate security constraints. For this reason, the application cannot communicate directly with the operating system kernel.
However, the use of software interrupts and other gate mechanisms imposes additional overhead and can lead to significant degradation of performance and even to lost data. In response to a software interrupt from an application, the operating system must save the state of the application, execute appropriate code to handle the interrupt, and then restore the application state, disabling further interrupt processing while this is taking place. This process can be time-consuming relative to other processing operations and in the aggregate can consume a significant share of the system's processing in a system experiencing frequent interrupts, such as when performing a significant number of I/O operations such as reading from a solid state disk or sending data over a network interface. Further, since interrupt processing is disabled, if other interrupts occur during interrupt processing the interrupts will not be handled and thus any information associated with the interrupt will be lost.
SUMMARY
Embodiments of the invention operate within the context of a system with a processor providing memory-monitoring functionality and having more than one processor core. The lower-privileged code of a first process, such as user application code, communicates directly with higher-privileged code of a second process, such as code of the operating system kernel, without using a software interrupt or other gate mechanism. This enhances overall system performance by eliminating the saving of state and processing inherent in interrupt handling, and also avoids missing events that may occur while other interrupts are masked during interrupt handling.
More specifically, the second process initializes a monitored memory area that is directly accessible by processes having at least the privilege level of the first process. The second process further initializes memory-monitoring hardware of the processor to monitor writes to the monitored memory area, such that the second process will resume execution from a dormant state when a write takes place.
With this initialization performed, the first process can use the monitored memory to communicate a request for the second process to carry out a privileged service on behalf of the first process, without needing to use a software interrupt or other gate mechanism. That is, when the first process needs the second process to perform a service such as sending a packet on its behalf, instead of making a request for the service via a system call triggering a software interrupt, the first process writes information describing the request (or a pointer to the information) into the monitored memory. The memory monitoring hardware then awakens the second process from a dormant state, and the second process reads the information and invokes the service using the information.
The features and advantages described in the specification are not all inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a high-level block diagram of a computing system, according to one embodiment.
FIG. 2 is an interaction diagram illustrating the interactions of components of the computing environment of FIG. 1 that occur when the first process invokes a service performed by the second process, according to one embodiment.
The figures depict embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.
DETAILED DESCRIPTION
FIG. 1 is a high-level block diagram of a computing system 100 , according to one embodiment. The system 100 may be, for example, a content server system in which a large number of requests to write and/or read data packets or files take place, such as occurs when a remote client of the system requests to see content like images or videos. The system 100 includes at least one processor 102 that executes instructions stored in a memory 105 , as well as memory monitoring hardware 135 that monitors accesses to specific portions of the memory. These components are now described in more detail.
The memory 105 holds instructions and data used by the processor 102 . In one embodiment, the memory 105 comprises RAM, such as conventional DRAM or SRAM. An operating system of the system 100 provides that a number of different privilege levels may be associated with resources of the system 100 , such as segments of the memory 105 .
The processor 102 executes instructions stored in the memory 105 , and can be a general-purpose processor such as an INTEL x86-compatible CPU. The processor 102 includes multiple cores, each able to execute instructions in parallel, independent of the other cores. The processor 102 stores the privilege level of the currently-executing code. The processor 102 also supports interrupts. Namely, when the processor 102 receives an interrupt input signal, the processor transfers control to appropriate interrupt handler code of the operating system kernel, changes the current privilege level to the highest level to indicate that the kernel is now executing, disables handling of certain types of interrupts, executes the interrupt handler code, restores the current privilege level to the prior level, re-enables interrupt handling, and returns control to the code that was executing at the time of the interrupt.
The processor 102 comprises memory-monitoring hardware 135 that supports instruction sets such as SSE3 (SIMD streaming extensions version 3). The memory-monitoring hardware 135 supports a ‘monitor’ instruction (e.g., the MONITOR instruction in SSE3) that specifies to the memory-monitoring hardware a particular segment or other region of the memory 105 . The memory-monitoring hardware 135 further supports a ‘wait’ instruction (e.g., the MWAIT instruction in SSE3) that causes the processor core executing the instruction to enter a dormant power-saving state until data is written to the memory region specified by the ‘monitor’ instruction, at which point the memory monitoring hardware causes the waiting processor core to resume execution. The memory-monitoring hardware may cause the waiting processor core to resume execution only if a write to the memory region is of at least some predetermined minimum size and at most some predetermined maximum size.
A first process 110 (such as a process for a typical user application) and a second process 120 (such as an event handler of the operating system kernel) are loaded into the memory 105 . The first process 110 is associated with a lower privilege level than that of the second process 120 . Thus, based on the security rules enforced by the processor 102 , the first process 110 may be denied access to certain resources and/or prevented from performing certain operations that the second process 120 might be allowed to access or perform. For example, in order to send a packet over a network, the first process 110 must write the packet data to a segment of the memory 105 belonging to the network protocol stack and having a higher privilege level than that of the first process. However, the hardware security checks of the processor 102 do not permit the first process 110 to write directly into the network protocol stack memory segment, and hence the first process requires the second process 120 to perform the write on its behalf.
The second process 120 further allocates a monitored memory area 130 with a privilege level such that the first process—or processes having at least the privilege level of the first process—are allowed to access that area. The monitored memory area 130 may be, for example, a single operating system-defined segment of memory, and may be of write-back memory type. The second process 120 further monitors the memory 130 using the ‘monitor’ and ‘wait’ instructions, entering a dormant state after executing the ‘wait’ instruction. Thus, when the first process 110 writes data to the monitored memory 130 , the second process 120 begins execution again and can take appropriate actions based on the data written to the monitored memory. In one embodiment, the first process 110 and the second process 120 are executed on separate cores of the processor 102 .
FIG. 2 is an interaction diagram illustrating the interactions of components of the computing environment of FIG. 1 that occur when the first process 110 invokes a service performed by the second process 120 , according to one embodiment. As illustrated, the second process 120 detects 205 memory write sizes that will cause the memory monitoring hardware 135 to wake a waiting processor core, such sizes being a property of the processor 102 . For example, the second process 120 might query the minimum and maximum hardware memory monitoring line sizes. The second process initializes 210 the monitored memory 130 , such as by issuing an operating system call, such as malloc( ) or other kernel-level memory-management function, to dynamically allocate a region of memory based on the detected memory write sizes and any required memory types (e.g., write-back memory) and by specifying a minimum privilege level required to access the monitored memory. The second process 120 also initializes 220 the memory-monitoring hardware 135 to transfer control in response to memory writes to the monitored memory 130 . That is, the second process 120 executes the ‘monitor’ instruction, with the size and location of the monitored memory 130 as an argument, to cause the hardware 135 to monitor the memory 130 . The second process 120 also executes the ‘wait’ instruction, which causes the processor 120 or processor core that executes the instruction to enter a dormant state while waiting for a memory write to the monitored memory 130 .
With the initialization of steps 205 - 225 completed, the first process can then use the monitored memory to invoke performance of a service by the second process without issuing a software interrupt. Specifically, the first process writes 230 , to the monitored memory 130 , information used by the second process to perform the service on behalf of the first process. As one example, assume that the first process 110 needs the service of sending a packet over a network interface of the system 100 , an operation that involves writing to memory used by the operating system network protocol stack. The protocol stack memory area has an associated privilege level higher than that of the first process 110 , and thus the first process cannot directly write the packet data to that memory but must instead delegate to the second process 120 or some other sufficiently privileged process. Instead of transferring control to the second process 120 via a software interrupt, the first process 110 instead writes 230 information describing the request to send the packet to the monitored memory 130 . (The information describing the request to send a packet might be, for example, an operation code known by the second process that indicates a packet sending operation, and the data of the packet itself, or a pointer thereto.) In response, the memory monitoring hardware 135 detects that a write to the monitored memory 130 has taken place and accordingly wakes 235 the second process 120 and transfers control to it.
Once awakened, the second process 120 reads 240 the information that the first process wrote into the monitored memory 130 , and then processes 245 that information to carry out the service request. Referring to above example of a request to send a packet, the second process 120 would inspect the operation code to determine that packet sending is desired and then would accordingly invoke the packet-sending functionality of the operating system's network stack to send the remaining information as a packet.
If the service produces a result, the second process can write the result to a location in memory 105 . With the service invocation completed, the second process 120 again executes the ‘wait’ instruction and enters a dormant state. The first process 110 continues its own execution, such as reading 260 the result (if any) produced by the service. (The second process could write a result to a predetermined area of memory 105 expected by the first process, for example, with the first process repeatedly polling that memory area while the second process is servicing the request, until a result is ultimately written by the second process.)
Thus, using the monitored memory 130 , the first process can directly provide the information for carrying out the service to the second process, without the need for a software interrupt or other form of gate.
The foregoing description of the embodiments of the invention has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure.
The steps, operations, or processes described herein may be performed or implemented with one or more hardware or software modules, alone or in combination with other devices. In one embodiment, a software module is implemented with a computer program product comprising a computer-readable storage medium containing computer program code, which can be executed by a computer processor for initiating the steps, operations, or processes described.
Embodiments of the invention may also relate to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, and/or it may comprise a general-purpose computing device selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a non-transitory, tangible computer readable storage medium, or any type of media suitable for storing electronic instructions, which may be coupled to a computer system bus.
Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.
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Embodiments of the invention operate within the context of a system with a processor providing memory-monitoring functionality. The lower-privileged code of a first process, such as user application code, communicates directly with higher-privileged code of a second process, such as interrupt-handling code of the operating system kernel, without using a software interrupt or other gate mechanism. This enhances overall system performance by eliminating the saving of state and processing inherent in interrupt handling, and also avoids missing events that may occur while other interrupts are masked during event handling. Specifically, the second process initializes a monitored memory area that is directly accessible by processes having at least the privilege level of the first process. The second process further initializes memory-monitoring hardware of the processor to monitor writes to the monitored memory area, such that the second process will resume execution from a dormant state when a write takes place.
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[0001] This is a Divisional patent application of application Ser. No. 10/494,475, filed Oct. 29, 2004, which is a US National Stage application of PCT Application PCT/GB02/05381, published as WO 03/048437 filed Nov. 29, 2002 claiming priority from British Application 0128692.1 filed Nov. 30, 2001.
[0002] This invention relates to the formation of sheet material from fibres particularly using a process known as hydroentanglement or spunlacing.
BACKGROUND
[0003] Prior patent application PCT/GB 01/02451 describes the use of hydroentanglement (or spunlacing) to produce a high quality reconstituted leather sheet material from waste leather fibres.
[0004] A feature of the procedure described in the prior application is the use of specialised screens through which hydroentangling jets are directed at high pressure, in contrast to previously known procedures where entangling commences at low pressure until the fibres are sufficiently interlocked to avoid disruption by the jets. Leather fibres entangle particularly readily, and with previously known procedures, they form a surface layer of entangled fibres that impedes further entanglement. This is particularly disadvantageous with thick webs needed for leather products but by using the aforesaid screens, jets can penetrate deeply at high pressure to hydroentangle throughout the depth of the web.
[0005] The difficulties with disruption and the formation of a surface layer arise because fibres resulting from the disintegration of waste leather are far shorter and finer than those normally used for hydroentangling. The screens of the prior patent application provide a means of constraining such fibres from being washed away by the jets, but even with screens it is difficult to constrain very short fibres such as are produced by hammer milling waste leather. Also, whatever the length of fibres about half the hydroentangling energy is wasted when using screens due to the solid parts of the screen shielding significant area of the web from the jets. The loss of energy when using screens and the lower output rates from using leather fibres of greater length are inherent with the procedure of the prior application.
SUMMARY OF INVENTION
[0006] An object of the present invention is to provide a method of entangling fibres to form sheet material whereby the aforesaid problems arising from use of screens and longer fibres can be avoided or at least minimised.
[0007] According to one aspect of the invention therefore there is provided a method of forming a sheet material from a mixture of fibres comprising base fibres and additional synthetic fibres, said synthetic fibres having outer meltable layers, comprising the steps of:
[0008] forming the fibres into a web,
[0009] heating to melt the outer layers of the additional synthetic fibres so as to cause such fibres to fuse together at intersections to form a network within the web,
[0010] subjecting the web to entanglement to entangle the base fibres whilst constrained by the network.
[0011] Preferably, the entanglement is hydroentanglement. Preferably also the base fibres are leather fibres.
[0012] Thus, in accordance with a second aspect of the invention there is provided a method of forming a sheet material from a mixture of fibres comprising leather base fibres and additional synthetic fibres, said synthetic fibres having outer meltable layers comprising the steps of:
[0013] forming the fibres into a web,
[0014] heating to melt the outer layers of the synthetic fibres so as to cause such fibres to fuse together at intersections to form a network within the web,
[0015] subjecting the web to hydroentanglement to entangle the leather fibres whilst constrained by the network.
[0016] The entanglement of the method of the invention is preferably performed using high pressure jets of liquid (particularly water) preferably in multiple passes. Reference is made to the prior application for further details of such features.
[0017] In a preferred embodiment, the invention provides a method of forming sheet material with a mixture of leather fibres and man made bicomponent fibres, said bicomponent fibres having outer layers with a lower melting point than the inner cores. The mixture of fibres is formed into a web, which advances through a heating means that melts the outer layers of the bicomponent fibres so they fuse at their intersections, and form a three dimensional network throughout the web. Fine jets of water at high pressure are then directed onto the web so they penetrate deeply and hydroentangle the leather fibres while these are constrained by the network of bicomponent fibres.
[0018] Fused bicomponent supporting networks are known but not in the context of the present invention.
[0019] Such networks are used in conjunction with wood pulp fibres to impart most or all of the finished product strength for applications such as wet wipes and absorbent sanitary products. The high pressure jets used in hydroentanglement would disrupt the bonding of such network and, where such networks are used with hydroentanglement, the bicomponent fibres are fused after hydroentanglement, thereby avoiding such disruption. With the present invention the network is used for a different purpose to that of providing structural reinforcement for the end product, and entanglement is effected after fusing.
[0020] A basic requirement of entangling is that fibres must move in order to entangle, and the fused network would be expected to impede the entanglement of the fibres. Surprisingly, it has been found that leather fibres can entangle effectively within such networks even if the apparent restraining effects are enhanced by compressing the webs containing the leather and bicomponent fibres while the surfaces of the bicomponent fibres are still tacky, thereby presenting a significantly denser layer to the hydroentangling jets.
[0021] With the arrangement of the invention, the network can take over part or all of the function of the external screens used in the method of the prior patent application. However, instead of acting on the surface, the network can provide a succession of much lighter screens within the depth of the web. Each internal screen can have relatively much more open area than an external screen, but collectively they can provide an effective and improved alternative to the external screen of the prior application. In particular the network of internal screens allows hydroentangling jets to penetrate deeply at pressures that would otherwise disrupt the web.
[0022] Apart from replacing the function of the screens, the bicomponent network can also improve the way the leather fibres hydroentangle. One of the difficulties of hydroentangling leather fibres is that even when using screens they consolidate so readily that they impede drainage of water through the web and the resulting flooding can prevent optimum entanglement. However, the three dimensional structure of the bicomponent network can even out the rate of consolidation of the web, which together with the deep penetration can assist the drainage of water through the web until full entanglement is achieved.
[0023] It is believed that this drainage effect is achieved by the three-dimensional network of bicomponent fibres providing a resilient restraint to compaction within the body of leather fibres. It is desirable to ensure that the network does not hold the leather fibres away from each other to the extent that there is insufficient proximity for them to entangle well with each other since this could result in a spongy material less desirable for leather products. This effect can be reduced or prevented by reducing the quantity of bicomponent fibres in the mix and/or using bicomponents of lower diameter and/or lower elastic modulus.
[0024] In normal hydroentangling practice most of the fibres can start off too far apart to entangle effectively, and a first pass through the jets is used to bring the fibres close enough to entangle. In a preferred embodiment of the present invention, the fibres are brought into closer proximity before entangling commences by compressing the web containing the bicomponent network before the fused junctions of the network solidify. This can more than halve the thickness of the web compared to conventional practice and can effectively eliminate the first hydroentangling stage used in conventional practice.
[0025] In the method of the prior application the external screen helped to compress the web at the first stage of entanglement, but this can incur significant loss of hydroentangling energy because of the surface area of the web being shielded from the jets. However in the present invention the solid parts of the internal bicomponent screens can be relatively insubstantial so there can be substantially less shielding of hydroentangling jets from the fibres. This can reduce the number of passes needed by the jets over the web to achieve full entanglement and reduce the energy consumed. Typical production speeds can also increase from 6 m/min mentioned in the prior application to over 10 m/min in the present invention.
[0026] Being relatively fine, the bicomponent network may be less effective than externally applied screens for masking the furrows in the surface caused by the jets. Accordingly, with the method of the present invention external screens may additionally be used (which may be generally of the kind described in the prior application) in at least one pass to eliminate or at least reduce or substantially prevent formation of surface furrows by the hydro-entanglement jets. In so far as the bicomponent network acts as a series of internal screens, externally applied screens can have more open area than the preferred openings described in the prior patent application thereby reducing the loss of energy. Such external screens still waste some energy, but they can be confined to passes where they are needed to mask jet lines. Typically this can be the last pass on the finish face, and possibly the first pass so that the jets bite less deeply while the fibres are least entangled.
[0027] The prior patent application describes a method for producing long leather fibres to improve performance of the finished product but such fibres also pass more slowly through the preferred equipment for air-laying the webs. However with the present invention, short leather fibres can be used without necessarily adversely affecting product performance because the network can reduce or eliminate some of the defects that arise with short leather fibres. For example, products made with short leather fibres are more liable to surface cracking, but short bicomponent fibres may still be beneficially used to enhance throughput from web laying equipment, as by fusing the bicomponent fibres to form a network, they act like much longer fibres and thereby more effectively constrain surface cracking. Short fibres are also more prone to erosion during hydroentangling, but the network of fused bicomponent fibres can considerably reduce this without interfering with the relatively small movements needed for hydroentanglement.
[0028] Unlike other fields of manufacture where short bicomponent fibres are fused at their intersections, the contribution of bicomponent fibres to primary strength can be negligible, and the proportion of such fibres in the total mix can preferably be minimised as they can seriously detract from leather-like handle. In cases where the performance of products made with short fibres needs to be significantly upgraded this can be achieved by incorporating normal, non-bicomponent fibres with a reduced proportion of bicomponent fibres.
[0029] The proportion of bicomponent fibre needed to provide the purely process benefits of the present invention can be as low as 2% of the total weight of web, and can be many times less than the percentage used in conventional applications where a bicomponent network is a primary source of strength. Apart from unacceptably increasing stiffness and coarsening the surface feel of the final product, a bicomponent network that provides significant structural contribution may reduce the attachment of leather fibres to internal reinforcing fabrics by impeding the leather fibres from locking into the interstices of the fabric.
[0030] Because of these limitations, in a preferred embodiment of the present invention bicomponent fibres are used with weak outer sheaths to promote a partial breakdown of the network as the web progresses through successive stages of hydroentangling. With each pass the increased entanglement of the leather fibres can compensate for the reduction of bonds between bicomponent fibres, and can result in end products with minimal stiffening from the network. Such a procedure would be a disadvantage in conventional practice but, as with the externally applied screens of the prior application, the main purpose of the network is to overcome processing problems peculiar to hydroentangling rather than providing structural strength.
[0031] Processing benefits of the bicomponent network also extend to producing the webs themselves, particularly with commercially available equipment normally used for air laying wood pulp fibres. Such processes can have high rates of production for short fibres like wood pulp, and the bicomponent network can significantly reduce the erosion of short fibres under hydroentanglement. This allows short leather fibres such as produced by hammer milling to be hydroentangled much more effectively than by the methods of the prior application.
[0032] A further processing advantage of bicomponent networks is that they can provide sufficient strength to the web before hydroentangling to allow webs to be wound onto reels at interim stages of production. This removes the need to feed webs directly from the air laying equipment to the hydroentangling line as in the method of the prior application, and allows the webs to be produced at optimum speeds determined by the air laying equipment without compromising the operation of the hydroentangling line. Thus, in one embodiment the (or each) web is wound on a reel after formation of the network, and the web is drawn from such reel to be subjected to said entanglement.
[0033] Furthermore, where the product requires two webs on either side of a reinforcing fabric, both webs can be formed using one air laying plant. Two reels of webs stabilised with bicomponent networks can then be fed to the hydroentangling line, and can result in a substantial saving of capital cost compared to the method of the prior application where two entire air laying means were required to continuously feed the hydroentangling line. Where a reinforcing fabric is used the base (leather) fibres preferably penetrate this so as to be entangled therewith.
[0034] The fibre content needed to provide adequate reel handling strength depends on web thickness, bicomponent content and the strength of the melt-able sheath on the bicomponent fibres. However, generally the percentage of bicomponent fibre needed to impart sufficient in-process strength for reel winding need be no more than the same low bicomponent content that can provide effective internal screens in the method of the present invention. This in-process strength for individual webs is well below the strength after hydroentangling, particularly after hydroentangling webs and reinforcing fabric to form a final product.
[0035] As with most fibrous products, fibre length preferably needs to be as long as possible. However, long leather fibres produced by textile reclaiming methods have a wide distribution of fibre length from around 1 mm to occasionally over 15 mm, and the upper end of the distribution can cause very slow production rates using air laying equipment designed for wood pulp fibres. It can therefore be preferable to limit the maximum length of such fibres to around 6 mm, for example by passing them through a conventional granulating machine (taking care to avoid shortening more than necessary to make a worthwhile improvement in air laying output). Such methods of shortening fibres can be very approximate, but preferably at least 90% of the fibres should be less than 6 mm for efficient air laying. Thus, in the method of the invention, in order to obtain improved throughput from air-laying equipment designed for wood pulp fibres, at least 90% of the base fibres have a maximum fibre length of 6 mm.
[0036] In the case of hammer milled leather fibres there is also a wide distribution of fibre lengths, but lengths are generally much less than produced by textile reclaiming methods. Typically the maximum length may be around 3 mm and, as with fibres produced by textile reclaiming methods, the average fibre length is significantly less than the maximum. No granulation is required for hammer milled fibres, but the much shorter length can result in a need to increase average length of the mix by adding manmade fibres of predetermined optimum length in order to improve the physical properties of the final product.
[0037] Unlike leather fibres, manmade fibres can be chopped to a constant length so they can all be of a length that provides the optimum balance between air laying throughput and performance of the finished product. For air laying equipment designed for wood pulp, the length of manmade inclusions may be around 6 mm, but recent improvements in air laying technique may make it feasible to increase this to over 10 mm. These indicative fibre lengths apply typically to bicomponent and non-bicomponent manmade fibres in the 1.7 dtex to 3.0 range. Finer fibres can significantly reduce air laying output unless fibre length is reduced appropriately.
[0038] Air laying speeds vary considerably depending not only on fibre length and diameter, but also on the smoothness and shape of fibres. In these respects leather fibres are particularly unfavourable regarding air laying throughput, as they are usually curly and have finely fibrillated branches that can impede flow through the perforated distribution screens of air laying equipment. Air laying rate for un-granulated leather fibres produced by textile reclaiming methods can be as low as 3 m/min for a 200 gsm web, but this can be more than doubled if the fibres are shortened. Laying rates for manmade and pulp fibres can be considerably faster.
[0039] Regarding the percentage of bicomponent fibre in the mix, it is generally preferable to keep this to the minimum as described earlier. The degree to which the bicomponent network compromises leather-like handle depends on end use, and for shoes the greater stiffness and wearing properties conferred by the bicomponent network can be more acceptable or even be of benefit compared to (for example) clothing leather. For shoes up to 10% of 3.0 dtex bicomponent can be used, but to obtain better handle it can be preferable to use under 5% bicomponent and a greater proportion of non-bicomponent fibres. In general the overall range for additional synthetic fibres is 2% to 10% by weight with a preference towards the lower end of the range.
[0040] From the viewpoint of providing effective internal screens, the number of bicomponent fibres can be as significant as their percentage by weight of total mix. For example, reducing from 3.0 to 1.7 dtex in a 5% mix would proportionately increase the number of fibres in the mix, and to obtain a similar screen effect, the percentage of 1.7 dtex fibres may need to reduce to below 3%. Using finer bicomponent fibres can also provide better surface feel to the finished product, which is an added benefit.
[0041] Commercially available bicomponent fibres are generally not less than 1.7 dtex, but end product handle can be improved by choosing bicomponents with a low elastic modulus, such as polypropylene. These usually have polyethylene melt-able sheaths that are not particularly strong but can still provide sufficient reel handling strength even at low percentage additions. As mentioned earlier some degree of bond weakness can be an advantage for some product applications as this can improve the handle of the final product. In applications where more stiffness is acceptable or required, stronger bicomponents can be used, such as polyester with nylon sheaths.
[0042] Bonding between bicomponent fibres at their intersections can be achieved by passing hot air through the web to melt the outer coating while the fibres are held between porous belts. The bond may not be strong enough to link short fibres together to contribute significantly to the tensile strength of the final product, but the bonds may be sufficient to provide an effective network for hydroentangling and enough anchorage to resist surface cracking of the finished product.
[0043] The fused intersections of the network may be at least partially disrupted by the entanglement.
[0044] Resistance to surface cracking can be enhanced by including ordinary non-bicomponent manmade fibres in the mix. Such fibres can also significantly improve peel resistance of the surface coating that is usually applied to the finished product. Furthermore, being free to move, non-bonded synthetic fibres can be more readily driven by jets into the interstices of the reinforcing fabric and thereby improve peel strength between the webs and the reinforcing fabric. This is particularly important for hard wearing shoes, and relatively high percentages of such fibres (compared to bicomponent) can be used without over-stiffening the final product.
[0045] In the case of a fabric reinforcing material having one or more webs or bodies of fibres united with the fabric, the (or each) web or body may contain a higher proportion of said further synthetic material adjacent the reinforcing layer than at the outer surface thereof.
[0046] The effect on handle of such further (non-bicomponent) fibres depends on their fineness as well as their percentage of mix, and in this respect they should preferably be not more than 1.7 dtex. For minimum effect on handle, such fibres can be into the “microfibre” range of well under 1.0 dtex, and with sufficiently fine manmade fibres, adequate handle can be maintained at over 10% of total fibre content. However reducing fineness increases the number of fibres present, which in itself can change the feel of the product. Alternatively where Improved peel resistance is more important than handle, coarser fibres can produce better all round results. Generally, for reasons of cost and detracting from the leather-like feel of the final product it is preferable to keep further synthetic fibre content to below 20% by weight of the end product sheet material. The range may be 5-20% by weight.
[0047] Particularly with coarser manmade fibres, even small percentages in the mix can detract from the characteristic surface feel of real leather, particularly as after buffing the superior abrasion resistance of manmade fibres can make them more prominent. In a further feature of the invention, hot air or other suitable heat sources are applied to the surface of the web after buffing at sufficient temperature to melt back the bicomponent fibres without adversely affecting the leather fibres. The technique exploits the high moisture retention of leather which keeps it cool, and its property of charring rather than melting when subjected to excess local heat. Any such charring can be brushed or lightly buffed away, leaving a substantially natural leather finish.
BRIEF DESCRIPTION OF DRAWING
[0048] The invention will now be described further by way of example only and with reference to the accompanying drawings in which:
[0049] FIG. 1 is a schematic view of initial stages of one form of apparatus used in the performance of the method of the invention and which shows the main operating principles of a commercially available plant for making a fibre web with a fused bicomponent network; and
[0050] FIG. 2 shows further stages of the apparatus for combining such web with reinforcing fabric and hydroentangling the resulting sandwich.
DETAILED DESCRIPTION
[0051] Referring to FIG. 1 , waste leather fibres made by textile reclaiming methods lightly chopped to a maximum length of approximately 6 mm are mixed with 4% of 1.7 dtex bicomponent fibres and 5% of 3.0 dtex standard polyester fibres both cut to constant 6 mm length. The mixture is evenly distributed at around 200 g/m2 onto a driven porous belt 1 by at least one pair of perforated drums 2 while the fibres are drawn onto the porous belt by vacuum box 3 .
[0052] The resulting web 4 of evenly laid fibres is transferred by a conventional vacuum conveyor 5 to porous belts 6 and 7 , which contain and partially compress the web while hot air from a box 8 is blown through belts 7 and 6 and web 4 , and received by a suction box 9 . The temperature of the hot air is sufficient to melt the outer sheath of the bicomponent fibres (but not the inner core) and thereby fuse the fibres together at their intersections.
[0053] Before the melted sheaths at the intersections of the bicomponent fibres solidify, the web may be compressed by nip rollers 10 to form a denser web consisting of un-bonded leather and polyester fibres supported by a three-dimensional network of fused bicomponent fibres. On solidification of the intersections the network provides sufficient strength for the web to be wound onto reel 11 for transport and/or storage.
[0054] Referring to FIG. 2 , two such webs 4 a and 4 b unwind from reels 11 a and 11 b together with fabric reinforcement 4 c from reel 12 , and are brought together by rollers 13 to feed onto a porous belt 14 . Webs 4 a , 4 b and fabric 4 c comprising a composite web 15 are conveyed by belt 14 through hydroentangling jets 16 , and water from the jets is drawn through web 15 and porous belt 14 by vacuum box 17 . Water rebounding from the surface of the composite web is collected in trays 18 and conveyed away as described more fully in the prior application.
[0055] For complete hydroentanglement the composite web is passed through a plurality of successive hydroentanglement stages, one or more of which may incorporate a screen applied over the surface of the web 15 . Hydroentanglement stages are arranged so that jets can be applied to both surfaces of the web, and for the present example, such application of jets is on alternate sides through 5 such stages at a speed of 10 m/min.
[0056] In this example perforated screens with an open area of approximately 60% made from chemically etched stainless steel of the type described in the prior application are applied to each side of the web for the final stage of hydroentangling in order to mask the furrow marks from the jets. To prevent coincidence lines forming on the surface, the pitch of the apertures of the screen is made the same as the pitch of the jet orifices.
[0057] Jet orifices for this example are 140 microns at 0.9 mm centres, and when applied through the screens, jet pressures can be at the maximum normally available in commercial hydroentangling equipment at 200 bar. Pressures without the screen may be reduced slightly to 180 bar, and unlike similar webs without a bicomponent network, this same high pressure can be applied at the first stage of hydroentangling without the need for an external screen. The resulting hydroentangled web may be finished by impregnating with emulsified oils, pigments and pigment fixatives as may be applied to natural leather, followed by drying and buffing both sides. The side that received three hydroentangling stages (and therefore has a higher degree of entanglement and attachment to the reinforcing fabric) dan then be coated with a leather-like finish by conventional means as used for coating synthetic leather.
[0058] The foregoing procedures may be suitable for shoe material, but for un-coated materials such as for clothing suede, web 4 may be on one side only of the reinforcing fabric and four hydroentangling stages applied, all onto the side having the web. After buffing and impregnation the web face may be treated with hot air to cause the projecting manmade fibres to melt and the surface brushed to remove any slight charring leaving a finish closely similar to natural leather.
[0059] The resulting sheet material is a high quality reconstituted leather having an excellent feel, strength and surface finish.
[0060] It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiment which are described by way of example only.
[0061] Thus, for example, the web may be wet laid, although there can be disadvantages with this.
[0062] As described in the prior patent application, webs can be wet laid by methods normally used for paper making or by carding if sufficiently long textile fibres are included to carry the leather fibres through the carding process. The use of bicomponent fibres which are added or which make up the carrier fibres provides a “screen” for hydroentangling according to the present invention. For effective carding, normally over 5% of 1.7 decitex carrier fibres of 20 mm or more is needed, and the leather fibres need to be made by textile reclaiming methods to be long enough to avoid excessive ejection of fines. For wet laying, the bicomponent fibres need to be short and the webs dried before fusing. This may not be wholly satisfactory when the next step is to wet the webs again for hydroentangling, while the disadvantages of carding include slow rates of production and wastage from the ejection of fine fibres.
[0063] A wide variety of variations are feasible within the scope of this invention. Jet orifice size, screen details, production speeds and other details provided in the prior application can broadly apply to the present invention. The main departure is the reduced application of surface screens, and to ensure good attachment to the reinforcing core, it is often desirable to hydroentangle on alternate sides of the fabric so that fibres are pushed evenly into the interstices of the fabric. Also, due to the stabilising effect of the bicomponent network, pressures can be higher and leather fibres shorter than in the method of the prior application.
[0064] Product compositions can vary widely and thickness of the web between the final coated surface and the internal reinforcing layer can differ substantially from the web forming the back layer. For example, instead of the equal webs implied in the previously described example, the front one may be 150 g/m2 and contain 15% non-bicomponent synthetic fibres and the back may be 250 g/m2 and contain 0% of non-bicomponent fibre. The bicomponent content for both webs, however, may be constant at 4%.
[0065] Fibre lengths can be determined largely by the production limitations of commercial web laying equipment and, where alternative web laying equipment (such as carding) can handle long manmade fibres, it may not be necessary to incorporate fabric reinforcement. Also, where jet markings are acceptable in the finished product, there may be no need for surface applied screens. Alternatively, screens may be used extensively to supplement the internal screens of the bicomponent network, particularly if the latter are very light and the leather fibres are particularly short.
[0066] Hydroentangling speeds can vary widely depending on a whole range of parameters, including weight per unit area of material being hydroentangled, open area of fabric reinforcement, jet pressures, jet diameter, jet spacing, number of passes through the jets, weight of bicomponent network, type of leather fibre, number of passes using external screens, and open area of screens. Generally lighter webs can be hydroentangled at faster speeds, and typically 600 g/m2 material may require 6 m/minute while 200 g/m2 may entangle fully at 15 m/min.
[0067] The choice of using relatively long waste leather fibres made by textile reclaiming methods or short ones made by milling (such as conventional hammer or disk milling) can depend on the cost and availability of the different types of waste leather. Milling is cheaper and can use waste leather shavings, which are usually cheaper than the sheet waste used in textile reclaiming plant. However end product quality can be lower and more costly manmade fibre additions may be needed to achieve acceptable performance. Blends of both types of waste fibre can also be used for intermediate quality products.
[0068] As with the prior application, the main limitation in weight of composite webs that can be hydroentangled is the onset of hydroentanglement itself as this reduces permeability to the jets and constricts further entanglement. Such constriction is far greater with leather fibres than conventional synthetic fibres but, by using the methods of this invention, it is possible to make acceptable product at relatively high composite web weights of around 600 g/m2. Producing acceptable quality end product at much above this weight is possible but becomes increasingly difficult. Lighter webs are easier to hydroentangle, and minimum web weights can be set more by limits of web forming accuracy and limited market demand for exceptionally thin leather products.
[0069] The inter-relationships between all the foregoing parameters are complex and can vary considerably for different types of end product. An optimum balance between output rate, cost and finished product performance can be established by conducting empirical trials within the broad guidance provided in this patent application. The bicomponent network and associated features of the present invention assist considerably in improving production rate and product quality at lower cost compared to the methods of the prior application.
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A method is described for forming reconstituted leather sheet material from a mixture of base fibres, such as leather fibres, and bi-component synthetic fibres which have outer layers which melt at a lower temperature than their inner cores. The fibres are mixed, formed into a web and then heated so that the synthetic fibres fuse together to form a network within the web. The base fibres are then tangled, whilst constrained by the network, preferably using hydroentanglement. A high quality reconstituted leather sheet material is thus produced.
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RELATED ART
[0001] Consumers are increasing relying on Short Message Service (SMS) text messages as a communication channel for sending and receiving information. In 2008 alone, over 4.1 trillion SMS text messages were sent. This represents a global commercial market of over $81 billion, and is increasing at a healthy rate.
[0002] Businesses are beginning to use SMS text messages on a larger scale, and are consequently looking at ways to contain the significant costs associated with sending large volumes of SMS text messages. For example, SMS text messages are typically limited to 140 ASCII characters or 70 Unicode characters. Hence, if a business sends an SMS text message that exceeds these limits, the SMS text message is broken up into multiple SMS text messages and the cost of sending the SMS text message increases. For this reason, businesses are forced to choose between relaying less information to their customers and paying for multiple messages.
SUMMARY
[0003] One embodiment of the present invention provides a system for facilitating cost-optimized mobile messaging. During operation, the system receives an encoded text message at a mobile device. Next, the system replaces a sub-string in the encoded text message with a corresponding sub-string from a data-dictionary to create a decoded text message. Finally, the system displays the decoded text message on the mobile device.
[0004] Note that this helps to reduce costs since small sub-strings in the encoded text message can be replaced with large sub-strings in the decoded text message, thereby allowing a larger message to be sent via the SMS protocol without sending as many characters.
[0005] In some embodiments of the present invention, the system also determines the data-dictionary for the encoded text message. Note that this can be handled on a per message, per sender, or a per device basis.
[0006] In some embodiments of the present invention, determining the data-dictionary for the encoded text message involves considering a port number on which the encoded text message was received.
[0007] In some embodiments of the present invention, determining the data-dictionary for the encoded text message involves analyzing a sub-string in the encoded text message that identifies the corresponding data-dictionary.
[0008] In some embodiments of the present invention, determining the data-dictionary for the encoded text message further involves determining if the data-dictionary is stored locally on the mobile device. If not, the system retrieves the data-dictionary from a remote data-dictionary repository over a different communication protocol than a communication protocol used to receive the encoded text message.
[0009] In some embodiments of the present invention, the system receives a new data-dictionary at the mobile device, and then stores the new data-dictionary in a local data-dictionary repository.
[0010] In some embodiments of the present invention, the system receives a second text message from the user at the mobile device to send to a second user. Next, the system determines a second data-dictionary for the second user. The system then encodes the second text message with the second data-dictionary to create a second encoded text message. Finally, the system sends the second encoded text message to the second user.
[0011] In some embodiments of the present invention, the encoded text message is a Short Message Service (SMS) text message.
[0012] In some embodiments of the present invention, the system replaces the sub-string in the encoded text message with a corresponding item of media content. Finally, the system plays the item of media content on the mobile device.
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIG. 1 illustrates a computing environment in accordance with an embodiment of the present invention.
[0014] FIG. 2 illustrates a system in accordance with an embodiment of the present invention.
[0015] FIG. 3 presents a flow chart illustrating the process of receiving a cost-optimized text message in accordance with an embodiment of the present invention.
[0016] TABLE 1 illustrates an encoded text message in accordance with an embodiment of the present invention.
[0017] TABLE 2 illustrates a corresponding decoded text message in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0018] The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
[0019] The data structures and code described in this detailed description are typically stored on a computer-readable storage medium, which may be any device or medium that can store code and/or data for use by a computer system. The computer-readable storage medium includes, but is not limited to, volatile memory, non-volatile memory, magnetic and optical storage devices such as disk drives, magnetic tape, CDs (compact discs), DVDs (digital versatile discs or digital video discs), or other media capable of storing code and/or data now known or later developed.
[0020] The methods and processes described in the detailed description section can be embodied as code and/or data, which can be stored on a non-transitory computer-readable storage medium as described above. When a computer system reads and executes the code and/or data stored on the non-transitory computer-readable storage medium, the computer system performs the methods and processes embodied as data structures and code and stored within the non-transitory computer-readable storage medium.
[0021] Furthermore, the methods and processes described below can be included in hardware modules. For example, the hardware modules can include, but are not limited to, application-specific integrated circuit (ASIC) chips, field-programmable gate arrays (FPGAs), and other programmable-logic devices now known or later developed. When the hardware modules are activated, the hardware modules perform the methods and processes included within the hardware modules.
Overview
[0022] Embodiments of the present invention facilitate cost-optimized mobile messaging by encoding long messages that exceed the character-limit of a single text message in a manner that reduces the number of characters of the message so that fewer text messages will be sent, thus reducing cost.
[0023] More specifically, one embodiment of the present invention provides a system for facilitating cost-optimized mobile messaging. During operation, the system receives an encoded text message at a mobile device, such as a cell phone or smart-phone. Next, the system replaces a sub-string in the encoded text message with a corresponding sub-string from a data-dictionary to create a decoded text message. For example, in one embodiment the sub-string “DLR” could be decoded to “Disneyland Resort.” In this example, three characters are used in the encoded text message to represent 17 characters in the decoded text message. Finally, the system displays the decoded text message on the mobile device.
[0024] TABLE 1 illustrates an encoded text message in accordance with an embodiment of the present invention. This text message includes 93 characters, and is difficult to understand outside of the context of the appropriate data-dictionary. As illustrated, the text message in TABLE 1 can be sent to a mobile device via a single Short Message Service (SMS) message.
[0000]
TABLE 1
ENCODED TEXT MESSAGE
T 1 25-30 2 26-34 3 24-39 4 24-39 998877556645 P 1 12-16
2 13-15 3 13-16 4 13-16 998877556646
[0025] TABLE 2 illustrates a corresponding decoded text message in accordance with an embodiment of the present invention. Note that the decoded text message of TABLE 2 corresponds to the encoded text message of TABLE 1. The decoded text message of TABLE 2 exceeds the SMS limit of 140 ASCII characters, and therefore would have required at least two SMS messages to be sent in unencoded form.
[0000]
TABLE 2
DECODED TEXT MESSAGE
Intuit Farmer's Market Quotes
Tomatoes
Market 1
25-30
Market 2
26-34
Market 3
24-39
Market 4
24-39
Agent Number
998877556645
Potatoes
Market 1
12-16
Market 2
13-15
Market 3
13-16
Market 4
13-16
Agent Number
998877556646
[0026] In this example, two SMS messages were reduced into a single SMS message, resulting in a 50% cost savings. In the case of Unicode messages and/or text messages with even more characters, potentially greater savings can be realized.
[0027] Note that, in the example illustrated in TABLES 1 and 2, the data-dictionary includes some style and form guides for the decoded text message. For example, the data-dictionary might stipulate that every text message decoded with the data-dictionary includes a pre-determined header, such as “Intuit Farmer's Market Quotes.”
[0028] Furthermore, the data-dictionary may include directions for formatting. For example, note that, while the encoded text message in TABLE 1 includes a simple character stream with no line breaks, the corresponding decoded text message of TABLE 2 includes line breaks after each quote, and blank lines between quote groups. These formatting guides can facilitate increased readability of the text message without requiring additional formatting characters to be sent in the encoded text message.
[0029] In some embodiments of the present invention, the system determines the data-dictionary for the encoded text message. Note that, in some embodiments of the present invention, the mobile device may include multiple data-dictionaries specific to different businesses, products, services, etc. In these embodiments, the system first determines which data-dictionary was used to encode the text message so that the same data-dictionary will be used to decode the text message.
[0030] In some embodiments of the present invention, determining the data-dictionary for the encoded text message involves determining a port number on which the encoded text message was received. For example, when the data-dictionary is first stored on the mobile device, the system can assign a port number to the data-dictionary. In this example, when a new text message is received on the specified port, the system knows to use the data-dictionary assigned to the port.
[0031] In some embodiments of the present invention, determining the data-dictionary for the encoded text message involves analyzing a sub-string in the encoded text message that identifies the corresponding data-dictionary.
[0032] Note that the text message may start with a special character to indicate that the following message is encoded. Furthermore, the text message may include an identifier immediately following the special character to indicate which data-dictionary to use to decode the encoded text message. For example, an encoded text message might start with the sub-string “|A4:” indicating that the text message is encoded with data-dictionary “A4.”
[0033] In some embodiments of the present invention, determining the data-dictionary for the encoded text message further involves determining if the data-dictionary is stored locally on the mobile device. If not, the system retrieves the data-dictionary from a remote data-dictionary repository over a different communication protocol than a communication protocol used to receive the encoded text message.
[0034] For example, if a mobile device receives an encoded SMS text message, and the device determines that the corresponding data-dictionary is not already loaded on the mobile device, the mobile device may request the data-dictionary over an alternative communication channel, such as Wi-Fi® or Bluetooth®. Although the data-dictionary can be received over any communication channel, including via SMS messages, it might make financial sense to only receive the data-dictionary over less costly communication channels than the communication channel over which the original encoded text message was received.
[0035] In some embodiments of the present invention, the system receives a new data-dictionary at the mobile device. Finally, the system stores the new data-dictionary in a local data-dictionary repository. Note that in some embodiments, the system includes a local repository of multiple data-dictionaries. In this embodiment, the system periodically receives new data-dictionaries to store locally on the mobile device, as well as receiving updates to existing data-dictionaries.
[0036] Note that once a new data-dictionary is received, in some embodiments of the present invention, encoded text messages already received at the mobile device may be decoded with the new data-dictionary. In this manner, text messages that could not be decoded because the data-dictionary was unavailable on the mobile device can be saved for viewing at a subsequent time when the data-dictionary does become available. Note that there may be advantages for an organization to send out encoded text messages prior to the release of the data-dictionary, and then to release the data-dictionary at a specified time.
[0037] In some embodiments of the present invention, the system receives a second text message from the user at the mobile device to send to a second user. Next, the system determines a second data-dictionary for the second user. The system then encodes the second text message with the second data-dictionary to create a second encoded text message. Finally, the system sends the second encoded text message to the second user.
[0038] Note that some embodiments of the present invention facilitate encoding text messages on the mobile device to send to remote users. In the previous examples related to receiving and decoding encoded text messages at the mobile device, the mobile device might also act as the encoder and sender of the encoded text messages.
[0039] For example, Bob decides to send a long text message to his friend Sally to give her directions to drive to his vacation home at Lake Tahoe. At some point prior to sending the text message, Bob and Sally registered for a text message encoding service and downloaded a data-dictionary including a list of commonly used words to their mobile devices. Note that this data-dictionary can be customized by Bob and Sally to include common terms and phrases that they use often.
[0040] Bob starts the process by selecting Sally as the recipient for the text message, and proceeds to type out a list of directions for driving to the vacation home. Upon pressing send, the system determines that both Bob and Sally have registered for the same data-dictionary. The system then proceeds to encode the text, and send the encoded text message to Sally's mobile device indicating that the message is encoded.
[0041] Upon receiving the encoded text message, Sally's mobile device determines the data-dictionary that Bob used to encode the encoded text message and decodes the encoded text message. Finally, Sally's mobile device displays the decoded text message to Sally.
[0042] Note that this is an advantage to both Bob and Sally because Bob can send a message to Sally that would have required two separate SMS text messages in an unencoded form, but only require one SMS text message to be exchanged in an encoded form. Bob is charged with sending only one SMS text message, rather than two; and Sally is charged with receiving only one SMS text message, rather than two.
[0043] In some embodiments of the present invention, the encoded text message is a Short Message Service (SMS) text message. Note that, while embodiments of the present invention discuss text messaging and SMS messages, the present invention is not meant to be limited to text messages and SMS messages. Moreover, any type of mobile messaging via any protocol that can be understood by a mobile device may be used in embodiments of the present invention.
[0044] In some embodiments of the present invention, the system replaces the sub-string in the encoded text message with a corresponding item of media content. Finally, the system plays the item of media content on the mobile device. Note that the item of media content can include any type of content capable of being played or displayed on the mobile device, including audio, video, and pictures.
[0045] For example, in some embodiments of the present invention, a sub-string in the encoded text message is converted to an audio stream and played to the user of the mobile device. For instance, Yashwant can send a text message to Soon-Yi stating “my name is Yashwant.” The system can then encode the text message to Soon-Yi as “m n i Yashwant.” When Soon-Yi receives the text message at her mobile device, the mobile device decodes the encoded text message and converts the sub-string to an audio stream. When Soon-Yi opens the text message o her mobile device, the encoded message is processed and an audio content is generated and played on the device.
[0046] In some embodiments of the present invention, the audio content can even be translated in a particular language. In this manner, the same message “m n I Yashwant” is read out as “Je m'appelle Yashwant” for a French recipient or “Mein Name ist Yashwant” for a Dutch recipient or “My name is Yashwant” for an English recipient. The language setting for translation and any other such settings can be read from the receiving device configuration.
[0047] Note that these embodiments are particularly applicable for various parts of world where mobile telephony has penetrated but illiteracy is rampant. It is useful for people who can use the mobile phone and can use the digits on the dial pad, but cannot compose short messages. These individuals can use a fixed combination of keys to play the incoming message.
Computing Environment
[0048] FIG. 1 illustrates a computing environment 100 in accordance with an embodiment of the present invention. Computing environment 100 includes a number of computer systems, which can generally include any type of computer system based on a microprocessor, a mainframe computer, a digital signal processor, a portable computing device, a personal organizer, a device controller, or a computational engine within an appliance. More specifically, referring to FIG. 1 , computing environment 100 includes clients 110 - 112 , users 120 and 121 , servers 130 - 150 , network 160 , database 170 , devices 180 , and appliance 190 .
[0049] Clients 110 - 112 can include any node on a network including computational capability and including a mechanism for communicating across the network. Additionally, clients 110 - 112 may comprise a tier in an n-tier application architecture, wherein clients 110 - 112 perform as servers (servicing requests from lower tiers or users), and wherein clients 110 - 112 perform as clients (forwarding the requests to a higher tier).
[0050] Similarly, servers 130 - 150 can generally include any node on a network including a mechanism for servicing requests from a client for computational and/or data storage resources. Servers 130 - 150 can participate in an advanced computing cluster, or can act as stand-alone servers. In one embodiment of the present invention, server 140 is an online “hot spare” of server 150 .
[0051] Users 120 and 121 can include: an individual; a group of individuals; an organization; a group of organizations; a computing system; a group of computing systems; or any other entity that can interact with computing environment 100 .
[0052] Network 160 can include any type of wired or wireless communication channel capable of coupling together computing nodes. This includes, but is not limited to, a local area network, a wide area network, or a combination of networks. In one embodiment of the present invention, network 160 includes the Internet. In some embodiments of the present invention, network 160 includes phone and cellular phone networks.
[0053] Database 170 can include any type of system for storing data in non-volatile storage. This includes, but is not limited to, systems based upon magnetic, optical, or magneto-optical storage devices, as well as storage devices based on flash memory and/or battery-backed up memory. Note that database 170 can be coupled: to a server (such as server 150 ), to a client, or directly to a network.
[0054] Devices 180 can include any type of electronic device that can be coupled to a client, such as client 112 . This includes, but is not limited to, cell phones, personal digital assistants (PDAs), smart-phones, personal music players (such as MP3 players), gaming systems, digital cameras, video cameras, portable storage media, or any other device that can be coupled to the client. Note that, in some embodiments of the present invention, devices 180 can be coupled directly to network 160 and can function in the same manner as clients 110 - 112 .
[0055] Appliance 190 can include any type of appliance that can be coupled to network 160 . This includes, but is not limited to, routers, switches, load balancers, network accelerators, and specialty processors. Appliance 190 may act as a gateway, a proxy, or a translator between server 140 and network 160 .
[0056] Note that different embodiments of the present invention may use different system configurations, and are not limited to the system configuration illustrated in computing environment 100 . In general, any device that is capable of communicating via network 160 may incorporate elements of the present invention.
System
[0057] FIG. 2 illustrates a system 200 in accordance with an embodiment of the present invention. As illustrated in FIG. 2 , system 200 can comprise server 150 , database 170 , appliance 190 , client 110 , devices 180 , or any combination thereof. System 200 can also include receiving mechanism 202 , decoding mechanism 204 , display mechanism 206 , determination mechanism 208 , processor 220 , and memory 222 .
[0058] In some embodiments of the present invention, system 200 comprises a cell phone, a smart-phone, a Personal Digital Assistant (PDA), or any other device capable of sending and/or receiving a mobile message and displaying the mobile message to user 120 .
Receiving a Cost-Optimized Text Message
[0059] FIG. 3 presents a flow chart illustrating the process of receiving a cost-optimized text message in accordance with an embodiment of the present invention.
[0060] During operation, receiving mechanism 202 receives an encoded text message at mobile device 180 (operation 302 ). Determination mechanism 208 then determines the data-dictionary used for encoding the encoded text message (operation 304 ).
[0061] Note that, as described previously, determining the data-dictionary used for encoding the encoded text message may involve determining a port number via which the encoded text message was received or analyzing the encoded text message for a sub-string that indicates the data-dictionary. Also note that the data-dictionary has been pre-loaded on mobile device 180 .
[0062] In some embodiments of the present invention, a specific sender may be tied to a specific data-dictionary. In these embodiments, mobile device 180 always uses the data-dictionary associated with a specific sender when receiving text messages from the specific sender.
[0063] Next, decoding mechanism 204 replaces a sub-string in the encoded text message with a corresponding sub-string from the data-dictionary to create a decoded text message (operation 306 ). Note that this includes applying form and formatting rules from the data-dictionary.
[0064] Finally, display mechanism 206 displays the decoded text message on mobile device 180 to user 120 (operation 308 ).
[0065] The foregoing descriptions of embodiments of the present invention have been presented only for purposes of illustration and description.
[0066] They are not intended to be exhaustive or to limit the present invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention. The scope of the present invention is defined by the appended claims.
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One embodiment of the present invention provides a system for facilitating cost-optimized mobile messaging. During operation, the system receives an encoded text message at a mobile device. Next, the system replaces a sub-string in the encoded text message with a corresponding sub-string from a data-dictionary to create a decoded text message. Finally, the system displays the decoded text message on the mobile device. Note that this helps to reduce costs since small sub-strings in the encoded text message can be replaced with large sub-strings in the decoded text message, thereby allowing a larger message to be sent via the SMS protocol without sending as many characters.
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TECHNICAL FIELD
[0001] This invention relates to the art of manufacturing parts from metallic sheet material using hot metal forming dies and more particularly to new and improved constructions and techniques for producing metal parts featuring the rapid and trouble-free extraction of formed parts from hot working surfaces of superplastic and quick plastic forming dies.
BACKGROUND OF THE INVENTION
[0002] Prior to the present invention, various types of forming equipment and processes have been developed to form sheets of alloys of aluminum and other suitable metallic materials into a wide range of items such as sturdy and lightweight panels for vehicles. Among such equipment and processes are superplastic and quick plastic forming dies and processes in which a ductile sheet of suitable metallic material is heated and stretched onto the forming surfaces of heated dies to improve production of high quality parts. Examples of such processes and equipment are found in U.S. Pat. No. 5,974,847 issued Nov. 2, 1999 to Saunders et al for “Superplastic Forming Process” and U.S. Pat. No. 5,819,572 issued Oct. 13, 1998 to Krajewski for “Lubricating System for Hot Forming”, both assigned to the assignee of this invention and both hereby incorporated by reference. In the patent to Saunders et al, a sheet of metal alloy is heated to a superplastic forming temperature and is pulled over and around a forming insert prior to using differential gas pressure to further stretch the sheet into conformity with a forming die surface so that thinning of the formed part is minimized. In the patent to Krajewski, dry lubricant is applied to metallic sheets which are subsequently heated to predetermined forming temperatures and formed into a part in superplastic forming die equipment. The lubricant initially provides improved forming of the part and subsequently improved release of the formed part from the forming die.
[0003] While such hot plastic forming processes and equipment generate improved parts, production efficiency has at times been diminished because of rejection of blemished or damaged parts produced by production procedures. Often such damage results from mechanical damage occurring from the physical removal of the formed part from the hot forming surface of the die and subsequently from the handling of the hot part. More particularly, after the part has been initially separated from the hot forming die, the part retains sufficient heat energy causing the surfaces thereof to retain some plasticity so that the tooling and handling marks may be imposed on the part from removal and stacking equipment.
[0004] Moreover, initial removal has heretofore been difficult because the formed part often firmly seats or grips on the die-forming surface. Dislodgment of such parts by extraction forces exerted through release tooling often results in part distortion or part marring by the tools or dies. This damage may be so substantial that parts do not meet specifications and have to be scrapped and recycled. The use of larger quantities of lubricants to improve parting requires more frequent and excessive die cleaning between forming operations and provides only minimized improvement in part removal. Often the lubricant remaining on the dies caused part imperfection on the show surfaces as pointed out in U.S. Ser. No. 09/748,096 filed Dec. 27, 2000 by Morales et al, entitled “Hot Die Cleaning for Superplastic and Quick Plastic Forming” and assigned to the assignee of this invention and hereby incorporated by reference.
SUMMARY OF THE INVENTION
[0005] In contrast to the prior art, the present invention is drawn to new and improved methods and mechanisms that provide improved parts and meets higher standards for ejection and removal of formed parts from hot superplastic and quick plastic forming dies while in the press and operating at elevated temperatures. More particularly, the invention is directed to the quick and effective removal of formed parts from hot forming dies without part damage and with optimized usage of parting lubricants.
[0006] This invention provides new and improved equipment and method for unseating the formed part from the heated die. In a preferred embodiment of this invention, a series of orificed air passages or jets extending through the forming surface of the die are employed to direct streams of compressed air between the die surface and the formed part. The pressurized air is effective at the interface between the forming surface and the formed part to provide an outwardly directed force, urging the formed part away from the forming surface of the heated die. The air passing through the jet orifices may accumulate between the formed part and the die surface to effectively reduce the amount of static friction that must be overcome in separating the two components.
[0007] Release air may also flow to the periphery of the formed part to break any sealing or loosen the seating between the part and the forming die to augment part release. Additionally, the air that passes through the orifices effectively cools the formed panel, which contracts at a high rate due to its high coefficient of thermal expansion and high surface area-to-mass ratio as compared to that of the die unit with its lower coefficient of thermal expansion and lower surface area-to-mass ratio. Since the die does not contract the same amount as the formed part, the difference in contraction reduces the area of intimate contact between the panel and the die surface, thereby reducing the amount of static friction that must be overcome in separating these two components from one another.
[0008] The above factors all contribute to the lowering of the force required to separate the formed panel from the die. This reduction in force allows the formed part to be removed from the hot die without damage and with minimum effort and distortion. Moreover, since the panel has been cooled by the air streams, its plasticity is reduced and can be quickly handled with removal and stacking equipment with minimized damage. With improved part extraction, parting lubricant usage can be reduced for improved production efficiency and effective cost reduction.
[0009] These and other features, objects and advantages will become more apparent from the following detailed description and drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a pictorial view of an opened forming press with forming die equipment producing parts from sheet metal blanks;
[0011] [0011]FIG. 2 is a diagrammatic cross-sectional view of the profiled hot dies as operatively mounted in the forming press of FIG. 1;
[0012] [0012]FIG. 3 is a diagrammatic cross-sectional view similar to the view of FIG. 2 but showing the forming die set in a forming position;
[0013] [0013]FIG. 4 is a cross-section view similar to the views of FIGS. 2 and 3 but showing the profiling dies in a part release position;
[0014] [0014]FIG. 4 a is a portion of the profiling dies just prior to part release; and
[0015] [0015]FIG. 5 is a diagrammatic pictorial view of a portion of a part produced by the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] Turning now in greater detail to the drawings, FIG. 1 illustrates a forming press 10 comprising a lower bolster plate 12 on which lower steel or forming die 14 is mounted. The press additionally has an upper reciprocating ram plate 16 that carries a chambered upper tool 18 , which corresponds to the upper tool of the above-referenced U.S. Pat. No. 5,819,572. Both of the plates 12 and 16 are electrically heated to establish the required heat energy levels in the die and the sheet metal blanks 20 for superplastic forming or quick plastic forming as is known in this art. The forming die 14 can be mounted on the upper plate instead of the lower plate and the chambered upper tool 18 operatively supported on the lower plate if desired and depending on the characteristics of the part to be made.
[0017] The ram plate 16 is moved by hydraulic cylinders 22 to cycle the ram plate from the open position for blank loading to the closed blank forming position and then back to the open shown in FIG. 1 for formed part removal. The blanks 20 utilized with one preferred embodiment of this invention are flattened sheets 24 of aluminum alloy coated with a dry lubricant 26 such as boron nitride to function as a release agent to prevent the formed panel 30 from sticking to the die and furthermore to enhance the stretching and formation of the part during forming operation.
[0018] As shown best in FIGS. 2 - 4 , the upper tool 18 is operatively connected to the lower face of the ram plate and projects downwardly therefrom. This tool has downwardly extending and rectilinear peripheral wall 34 whose free end 36 provides a continuous face seal 38 which sealingly engages the upper surface of the metal sheet 24 to define an air chamber 40 (see FIG. 3) when the upper tool is brought into engagement therewith during a part-forming operation. The air chamber 40 is supplied with pressurized air through an orifice 44 in an internal upper wall 46 connecting the sidewalls. The orifice is fed with pressurized air from a compressor or other source 48 operatively connected thereto by air line 50 and pneumatic controls 52 provided with conventional air control valves therein to control the feed and exhaust of air from the upper and lower tooling for metal-forming operation.
[0019] The lower tooling or die steel 14 has a rectilinear peripheral wall 54 extending upwardly from connection with the face of the bolster plate 12 to a continuous peripheral edge 56 that has pneumatic sealing engagement with the bottom surface of the alloy sheet 24 . The steel lower tool further comprises a thick main forming body 60 of a mass considerably greater than that of the thin metal blank sheet 20 . The upper surface of the main body of the forming die is profiled to form the desired shape of the part to be made. The main body is further provided with a plurality of air passages 64 therein that have small diameter orifices 63 formed at strategic locations in the forming surface of the die. As shown, the air passages pneumatically connect to lower fittings 65 of a manifold 66 . The manifold pneumatically connects to the controls 52 by air line 68 .
[0020] In operation, a loading arm 74 of a robot 76 or other suitable loading unit picks up a sheet 24 of aluminum alloy from a stack 78 of the blank sheets and moves and releases the sheet into operative position in the opened forming die unit of the forming press 10 . The heated ram and bolster plate elevates and maintains the temperature of the upper and lower tools at a suitable forming temperature so that the temperature of loaded sheet quickly rises to the desired heat energy level for metal forming. The loading arm is removed and cycled to pick up a new sheet. With the sheet in position, the hydraulic cylinders 22 are operated by pressure controls for the press, not illustrated, to move the chambered upper tool 18 downwardly from the FIGS. 1 and 2 position to the forming position in FIG. 3. The controls 52 are then activated to charge the sealed chamber 40 with pressurized air or other inert forming gas that expands to fully stretch the sheet around the profile of the forming die to effect the forming of the panel or part 30 . During such forming, the lower air passages 64 are open to exhaust so that there is no entrapment of gas pockets below the formed part to possibly distort portions thereof during forming thereof. After the panel is formed, the controls 52 are active to exhaust the upper chamber 40 and to pressurize the interface between the formed panel and the profiling surface of the forming die to augment panel release. Press controls are operated to open the press to move the upper forming chamber to the position of FIGS. 1 and 2. Robot arm 80 then extends and the gripping end 84 thereof grips the formed part 30 and removes it to a completed stack 88 for subsequent handling.
[0021] Part removal is enhanced since just prior to the entry of the removal arm into the open press, the controls direct streams of pressurized air into the body of the lower steel die via the manifold. The injected air under the panel tends to break any sealing between the panel and the forming die as diagrammatically illustrated in FIG. 4 a and further provides a lifting force that urges the panel from the die as best illustrated in FIG. 4. Moreover, since the aluminum sheet has a much smaller mass and thickness and a larger thermal conductivity as compared to the mass, thickness and the thermal conductivity of the steel forming die, the sheet cools at a rate substantially higher than that of the die. With this differential, the panel quickly shrinks relative to the die so that it is no longer the same size as the die and splits therefrom. This further enhances extraction by the robot arm 80 as illustrated in FIG. 4. With the panel cooled, its rigidity is increased, providing for improved removal by the robot arm, particularly eliminating panel deformations previously experienced with removal of parts in which substantial heat energy remains in the formed part. With this invention, removal time is shortened so that press cycling time is shortened to optimize part production.
[0022] [0022]FIG. 5 illustrates the part 30 with some dimpled configuration 90 induced by air distributed through the orifices 63 that may be formed on the outer surface of the part. In such cases, the air passages are strategically located so that that they are hidden in recesses for molding strips, cutouts or other non-observable areas in finished panels or other plastically-formed parts.
[0023] While some preferred methods and mechanisms have been disclosed to illustrate the invention, other methods and mechanisms embracing the invention can now be adapted by those skilled in the art. Accordingly, the scope of the invention is to be considered limited only by the following claims.
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Equipment and method for the rapid and easy extraction of formed metal parts from forming dies while in a press and operating at elevated temperatures. The invention features the controlled supply of streams of air or other inert gas to the interface of the hot surface of the forming die and the formed panel to augment removal so that flaws from removal equipment are minimized for optimized production of high quality parts. High velocity air is discharged through nozzles onto the forming surfaces of hot forming dies to cool the forming die and the part that contract at different rates and pop the part from the surface.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a high-reflectance silver mirror employing a phosphorus-containing glass base material and a process for production thereof. The present invention relates also to a reflecting optical element employing the silver mirror.
2. Related Background Art
Conventionally, the reflection layer of a mirror or the like on the reflection face thereof has been formed of a thin film of a metal with a high reflectivity such as aluminum and silver. In particular, silver has widely been used owing to its prominently high reflectivity in the visible wavelength region.
The thin metal layer of aluminum, silver, or the like has conventionally been formed by a dry process such as vacuum vapor deposition, sputtering, and ion plating. In particular, as for the silver film, it can also be formed by a wet film-forming process exemplified by a silver mirror reaction.
The thin metal film used in the silver mirror may be constituted of a single metal layer, or may have a laminate structure in combination with another layer such as an oxidation-preventing layer for preventing oxidation of the metal thin film or a reflection-increasing film for improving the reflection properties of the thin metal film.
In recent years, optical elements in various forms are commercialized which are produced by melting low-melting glass and forming the resulting melt in a mold into a desired shape of optical elements. The low-melting glass contains phosphorus in many cases.
However, the high-reflectance silver mirrors of the prior art involve disadvantages given below.
The conventional reflecting silver film used in the silver mirrors is usually formed by means of a dry vacuum deposition process such as vacuum vapor deposition, sputtering, and ion-plating. By such a dry process, the reflecting silver film may be formed with difficulty on an article in a complicated shape, or the production thereof on the complicated article may require a complicate film-forming apparatus and a complicate production process, raising the film forming cost.
For the cost reduction of the film formation, wet processes are investigated: the process including the silver mirror reaction, and an autocatalytic electroless plating. However, the phosphorus-containing glass as the base material is less resistant to chemicals. Therefore, in formation of the film by a wet process directly on the phosphorus-containing glass base material, the phosphorus component may be dissolved out so that the base material may be collapsed, and in other words, the surface of the base material may be damaged remarkably to become useless for optical elements, disadvantageously.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a silver mirror producible at a lower cost and having a high-reflectivity. Another object of the present invention is to provide a process for producing the silver mirror. A still another object of the present invention is to provide a reflecting optical element employing the silver mirror.
The present invention provides a high-reflectance silver mirror comprising a base material made of phosphorus-containing glass and a high-reflectance film comprising a silver layer formed thereon, the high-reflectance film being formed by a wet film-forming method on an acid-resistant protection film provided on the base material.
The present invention also provides a reflecting optical element having a light travel path and a light reflection face provided in the light travel path, the light reflection face comprising the high-reflectance silver mirror of the above constitution.
The present invention also provides a process for producing a high-reflectance silver mirror comprising a base material made of phosphorus-containing glass and a high-reflectance film comprising a silver layer formed thereon, comprising the steps of coating the base material with an acid-resistant protection film, and forming the high-reflectance film on the acid-resistance protection film by a wet film-forming method.
According to the present invention, the base material made of phosphorus-containing glass is protected by a protection film formed of an acid-resistant material, whereby the silver layer can be formed by a wet film-forming process without causing the phosphorus-containing glass to be dissolved in the solution and also without causing the base material of phosphorus-containing glass to be collapsed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a sectional view of a base material for explaining the surface treatment of the base material in Example 1.
FIG. 1B is a sectional view of a base material for explaining the surface treatment of the base material in Comparative Example 1.
FIG. 2 is a flow chart of an example of treatments in the electroless plating process.
FIG. 3 is a schematic sectional view of an example of the constitution of the silver mirror of the present invention.
FIG. 4 is a schematic sectional view of another example of the constitution of the silver mirror of the present invention.
FIG. 5 is a schematic sectional view of a still another example of the constitution of the silver mirror of the present invention.
FIG. 6 is a schematic sectional view of a further example of the constitution of the silver mirror of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The silver mirror base material used in the present invention is made of phosphorus-containing glass, for example, glass having a low melting point, being formable in a mold into an optical element, and having optical transparency.
Any of wet film-forming processes can be employed in the present invention provided that the process is capable of producing the silver layer of a desired performance and a desired quality on the base material. The wet film-forming process preferably includes electroless plating; in particular, autocatalytic electroless plating. The autocatalytic electroless plating causes a silver deposition reaction to take place selectively on the optical base material. This process enables control of the reaction velocity according to the composition of the plating bath, thereby avoiding a waste of the plating bath. Also, this process produces a silver layer of a sufficiently uniform thickness, thereby advantageously providing a silver layer having uniform distribution of the reflection properties.
Generally, in the autocatalytic electroless plating, a catalytic metal or a catalytic metal ion is applied onto the base material for the purpose of accelerating a metal deposition reaction in the plating bath, and the base material having been given the catalyst is immersed into the plating bath to cause the metal deposition reaction to proceed on the base material so that the plating is carried out.
The catalytic metal or the catalytic metal ion for accelerating the metal deposition reaction on the base material in the plating bath is not specially limited, provided that the metal or metal ion is capable of accelerating the silver deposition reaction in the electroless silver plating bath. Preferably, metals such as gold, silver, copper palladium, cobalt, tin, and nickel; metal ions thereof; and colloids containing these metals or metal ions may be used in the present invention.
The surface of the base material may be pretreated for uniform application of the catalytic metal or catalytic metal ion onto the base material in the plating bath. The pretreatment of the base material surface may include various kinds of treatments for lowering surface energy of the film-forming face of the base material such as etching with an acid or an alkali, UV-ozone treatment, corona discharge treatment, and excimer irradiation; treatments for surface hydrophilicity with a material having a polar group such as surfactants; and combinations of the above treatments. With the above treatments appropriately selected, the catalytic metal or catalytic metal ion can be applied uniformly on the base material.
The catalytic metal ion, which is less adsorptive to the base material may, in some cases, fall off the base material into the plating bath to accelerate decomposition of the metal bath. To prevent such an undesirable phenomenon, the catalytic metal ion may preferably be reduced to be fixed as the catalytic metal on the base material. There is no particular limitation on the reducing agent to be used at that time, and any reducing agent commonly used may be utilized for the reduction.
The electroless plating bath for forming the silver layer contains a soluble silver ion, a reducing agent for reducing the silver ion to deposit it on the base material, a chelating agent for formation of a silver ion chelate to stabilize the plating bath, a pH-controlling agent for preventing increase of the hydrogen ion caused by oxidation of the reducing agent to prevent dropping of the driving force of the plating reaction, and other additives.
The reducing agent is not limited provided that it is capable of reducing the silver ion dissolved in the plating bath, and formaldehyde, Rochelle salt, hydrazine, and hydrazine-borane may preferably used. Cobalt sulfate is also useful therefor as described in HU201360B (Hungarian Patent Publication).
Also, the chelating agent is not limited provided that it is capable of forming a chelate with the silver ion dissolved in the plating bath to prevent deposition of the silver in the plating bath and capable also of easily depositing the silver onto the base material with the aid of the catalyst adsorbed by the base material. Cyan or the like may be used. However, the cyan is extremely toxic and is not preferred for industrial use. As described in the patent publication HU201360B, ammonia or an ammonia derivative may be used as the chelating agent.
The acid-resistant protection layer, which is provided in the vicinity of the base material side relative to the silver layer, should preferably be resistant to the acids to prevent penetration of an acidic substance from the plating bath into the base material surface, have suitable properties as a foundation for the high-reflectance silver layer, and have sufficient transparency as an optical film. The material for the acid-resistant protection layer may preferably include various resins such as acrylic resins, polycarbonate resins, polystyrene resins, amorphous polyolefin resins, and amorphous fluororesins; metal fluorides such as MgF 2 ; metal oxides such as SiO 2 , TiO 2 , ZrO 2 , Al 2 O 3 , ZnO 2 , and SnO 2 ; and materials constituted of hydrolyzates of metal alkoxides. Of these, metal alkoxides and metal alkoxide hydrolyzates may particularly preferably used because those materials are excellent in the acid resistance and ease to form a film on the phosphorus-containing glass base material, and further can provide a better foundation for the formation of the silver layer.
The metal alkoxide may include the compounds represented by general Formulas (I) and (II):
M(OR) a (I)
M(OR) n (X) a-n (II)
where M is an atom selected from the group consisting of Si, Al, Ti, Zr, Ca, Fe, V, Sn, Li, Be, and B; R is an alkyl group; X is an alkyl group, an alkyl group having a functional group, or a halogen atom; a is the valence of M; and n is an integer from 1 to a. The group X may preferably include alkyl groups having at least one functional group of carbonyl, carboxyl, amino, vinyl, and epoxy.
Particularly preferable metal alkoxides may include Si(OC 2 H 5 ) 4 , Al(O-i-C 3 H 7 ) 3 , Ti(O-i-C 3 H 7 ) 4 , Zr(O-t-C 4 H 9 ) 4 , Zr(O-n-C 4 H 9 ) 4 , and Sn(O-t-C 4 H 9 ) 4 .
The acid-resistant protection layer may be formed, for example, by dissolving a metal alkoxide in a suitable solvent, applying the solution onto the glass base material for coating, and heating and baking the coating substance; or otherwise by dissolving a metal alkoxide in a suitable solvent together with water or an acidic catalyst for accelerating the hydrolysis of the alkoxide, applying the solution onto the glass base material for coating, and heating and baking the coating substance to form a film. The temperature conditions for the heating and baking are selected so that a thin film of desired properties and quality can be obtained and, at the same time, the base material is not adversely affected.
The acid-resistant protection layer may have a thickness ranging preferably from 0.01 μm to 1 μm.
In the case where the light traveling and penetrating through the interior of the base material is reflected (reflection occurring at the back face or inside face of the silver layer) in the high-reflectance silver mirror of the present invention, at least a higher-refractivity thin film and a lower-refractivity thin film are formed in this order from the side of the base material as an interlayer between the base material and the silver layer, and at least the film contacting with the silver layer is made an acid-resistant protection layer. With this constitution, the silver layer can be formed by a wet film-forming process on the base material of phosphorus-containing glass, and as a result, a high-reflectance silver mirror which can further increase the reflection at the silver layer can be provided. FIG. 5 shows an example of such a constitution.
This higher-refractivity thin film can be formed from a metal oxide such as TiO 2 , ZrO 2 , and Al 2 O 3 ; or a hydrolyzate of a metal alkoxide such as Al(O-i-C 3 H 7 ) 3 , Ti(O-i-C 3 H 7 ) 4 , and Zr(O-t-C 4 H 9 ) 4 . The lower-refractivity thin film can be formed from a metal fluoride such as MgF 2 , a metal oxide such as SiO 2 , a hydrolyzate of a metal alkoxide such as Si(OC 2 H 5 ) 4 , or a low refractivity resin such as an amorphous fluororesin. One or both of the higher-refractivity thin film and the lower-refractivity thin film can be formed by a wet film-forming process or a dry film-forming process such as vacuum deposition.
In the other case where the light projected from outside the base material is reflected directly by the silver layer (reflection occurring at the front face or outside face of the silver layer), a lower-refractivity thin film and a higher-refractivity thin film may be formed in this order on the silver layer. FIG. 6 shows an example of such a constitution, in which the layer 32 is an acid-resistant protection layer made of acrylic resin. Any known constitution may be employed as the constitution of the thin films. In this case, the refractivity thin films need not be acid-resistant.
A functional thin film may be provided on the base material as necessary in addition to the silver layer, the higher-refractivity thin film and the lower-refractivity thin film.
For better optical properties, the reflectivity (R) of the front face or the back face of the silver mirror formed by the wet film-forming process may preferably be in the range of 89.0%<R<99.5% (at 400 to 900 nm). For obtaining the high reflectivity and higher quality of the silver layer without defects such as cracking of the film, the thickness (d) of the silver layer may preferably be in the range of 0.1 μm<d<1 μm.
The silver mirror of the present invention can be used as a reflection face in a light travel path in optical systems having combination of a reflection mirror, a prism, a lens and other optical elements.
EXAMPLES
The present invention is described below in more detail by reference to examples.
Example 1 and Comparative Example 1
FIGS. 1A and 1B show the reflection film constitutions of the silver mirrors of Example 1 and Comparative Example 1, respectively. In Example 1 (FIG. 1 A), on the entire face of a phosphorus-containing glass base material 11 which was formed with a metal mold into a desired shape, a TiO 2 layer 12 (100 nm) was formed by vacuum vapor deposition. In Comparative Example 1 (FIG. 1 B), the TiO 2 layer was not formed. In addition, the glass base material 11 is formed of phosphorus type glass containing about 10 to 20 atomic % of phosphorus (trade name: LPHL-1, produced by Ohara Co.).
On the above two different base materials was coated an Ag layer (150 nm) by means of a silver mirror reaction to prepare high-reflectance silver mirrors. The silver mirror reaction for the coating was conducted by immersion using the solutions having the compositions shown in Table 1. In the immersion coating, the base material was firstly immersed in the silver solution shown in Table 1, and the reducing solution was then added thereto dropwise.
In Comparative Example 1, the base material began to be corroded or dissolved on immersion thereof into the silver solution and was collapsed, so that any silver mirror could not be formed. In Example 1, a high-reflectance silver mirror was obtained.
Also, when phosphorus type glass containing about 10 to 20 atomic % of phosphorus (trade name: PSK 50, produced by Sumita Optical Glass Co., Ltd.) was used as the glass base material in Example 1 and Comparative Example 1, similar results were obtained.
TABLE 1
Silver solution
Reducing solution
Silver nitrate
20 g
Formaldehyde (37%)
5.4 g
Ammonia (28%)
20 mL
Water
14.6 g
water
300 mL
Example 2
On the entire face of a glass base material made of the phosphorus-containing glass (trade name: LPHL-1) which was formed with a metal mold into a desired shape, a TiO 2 layer (100 nm) was formed by the vacuum vapor deposition. Further on the TiO 2 layer, an Ag layer was formed and superposed by an electroless plating method through the steps shown in FIG. 2 . The steps of FIG. 2 are explained below in detail. The portion of the TiO 2 layer on the base material where the silver layer was not to be formed was masked (Step (a)). The surface of the base material was then treated by corona discharge using a corona discharger (manufactured by Kasuga Denki Co., Ltd. (Step (b)). Thereafter, the base material was immersed into an aqueous 20 mL/L solution of a surfactant (Predip Neoganth B, produced by Atotech Japan Co., Ltd.) for one minute (Step (c)), and further the base material was immersed into an aqueous 50 mL/L solution of Activator Neoganth 834 (produced by Atotech Japan Co., Ltd.) at 35° C. for 5 minutes for Pd catalyst application (Step (d)). After the treatment, the base material was washed with water for 2 minutes and then treated for reduction (Step (e)) by immersion into an aqueous 5 mL/L solution of Reducer Neoganth WA (produced by Atotech Japan Co., Ltd.) as the reducing agent for 5 minutes. The base material was washed again with water for 2 minutes, and immersed in an electroless silver plating bath having a composition shown in Table 2 for 15 minutes for electroless silver plating (Step (f)). Finally the mask formed in the above Step (a) was removed to obtain a high-reflection silver mirror.
TABLE 2
Component and conditions
Concentration and conditions
Silver nitrate
6.8 g/L
Cobalt nitrate heptahydrate
28 g/L
Aqueous ammonia (28%)
121 g/L
Ammonium sulfate
99 g/L
pH
10.0
Temperature
25° C.
Example 3
The construction of a reflectance film of a silver mirror in this Example is shown in FIG. 3. A base material 31 made of phosphorus-containing glass for preparing optical elements (trade name: PSK 50) was coated with a water-soluble acrylic resin 32 (200 nm) (Top Guard YD: aqueous ¼ dilution solution, produced by Okuno Chemical Industry Co., Ltd.) by a dip coating method. The base material-drawing speed was controlled to be 80 mm/min. The acrylic resin-coated base material was baked at 100° C. for 30 minutes. On the acrylic resin layer 32 , an Ag layer 33 (150 nm) was formed by the electroless silver plating in the same manner as in Example 2 to obtain a high-reflectance silver mirror.
Example 4
The construction of a reflectance film of a silver mirror in this Example is shown in FIG. 4 . On a base material 41 made of phosphorus-containing glass (trade name: LPHL-1) which was formed with a metal mold into a desired shape, a TiO 2 layer 42 (100 nm) was formed by means of a sol-gel process. The process of TiO 2 film formation is explained below in detail.
In 500 g of ethanol was dissolved 15 g of titanium tetraisopropoxide (Ti(O-i-C 3 H 7 ) 4 ). Thereto 0.1 g of hydrochloric acid (35 wt %) was added. This solution was employed as the TiO 2 coating solution. This coating solution was applied onto the surface of the base material by a dip coating method at a drawing speed of 100 mm/min. The coating layer was baked at 250° C. for 15 minutes.
On the base material coated with the TiO 2 layer 42 , an Ag layer 43 (150 nm) was overlaid by the electroless plating process in the same manner as in Example 2 to obtain a high-reflectance silver mirror.
Example 5
The construction of a reflectance film of a silver mirror in this Example is shown in FIG. 5 . On a base material 51 made of phosphorus-containing glass (trade name: LPHL-1) as formed with a metal mold into a desired shape, an amorphous fluororesin layer 52 (100 nm) was formed by the dip coating method. The coating solution was a 1 wt % solution of an amorphous fluororesin (trade name: CYTOPCTL-801M,) in a solvent (trade name: CT-Solv. 100, produced by Asahi Glass Co.). The speed of drawing the base material was 80 mm/min. The base material thus coated with the amorphous fluororesin was baked at 100° C. for 30 minutes.
On the base material having been coated with the amorphous fluororesin film, a TiO 2 layer 53 (100 nm) was overlaid in the same manner as in Example 4. Further, an Ag layer 54 (150 nm) was formed thereon by the electroless plating process in the same manner as in Example 2 to obtain a high-reflectance silver mirror.
Example 6
The construction of a reflectance film of a silver mirror in this Example is shown in FIG. 6 . On the silver layer 33 as obtained in the same manner as in Example 3, an amorphous fluororesin layer 62 (100 nm) was formed in the same manner as in Example 5. Further, on the amorphous fluororesin layer, a TiO 2 thin film 63 (100 nm) was overlaid in the same manner as in Example 4 to obtain a high-reflectance silver mirror.
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A high-reflectance silver mirror has a high-reflectance film comprising a silver layer formed on a base material made of phosphorus-containing glass. The high-reflectance film is formed by a wet film-forming process on an acid-resistant protection film covering the base material. A reflecting optical element employing the high-reflectance silver mirror, and a process for producing the high-reflectance silver mirror are also provided. The high-reflectance silver mirror is producible at a reduced cost and has improved reflectivity.
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REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 09/621,835, filed Jul. 24, 2000, now abandoned.
FIELD OF THE INVENTION
This invention relates to fluorescent lamps and, more particularly, to the shatter-proofing of fluorescent lamps.
BACKGROUND Of THE INVENTION
In my previous U.S. Pat. No. 3,673,401 I disclosed an arrangement in which a fluorescent lamp could be rendered shatterproof by using a cylindrical transparent and non-frangible shield of polymeric material together with two rubber-like plastic end-caps. The cylindrical shield was made from a length of extruded plastic tubing having a diameter suitable for each size of fluorescent lamp and the end-caps were provided with a peripheral rib or flange to abut the end of the cylindrical tubing. The arrangement required hand assembly involving several steps. First, one of the end-caps was friction fitted onto the metallic ferrule at one end of the fluorescent lamp. Next, the cylindrical shield was said over the fluorescent lamp until its end abutted the peripheral rib. Finally, the second end cap was friction fitted over the opposite metallic ferrule and its position adjusted until its peripheral rib abutted the opposite end of the cylindrical shield. Reliability of the shatterproofing depended on how carefully the four elements were put together by the user. If the fluorescent lamp were dropped or fell from its fixture so that its glass envelope broke, the shards of glass as well as the phosphorescent powders and mercury used in the lamp could all be contained. This type of shatterproof fluorescent lamp assembly became very popular in industrial settings, especially those which had to be safeguarded against contamination by toxic particulates and materials.
More recently patents have been issued directed to making the assembly hold together more securely. Thus, U.S. Pat. Nos. 5,173,637 and 4,924,368 teach that an adhesive should be applied to the exterior of the metallic ferrule of the lamp so as to cause the end cap to better adhere to the lamp. While the use of adhesive allowed greater tolerances to be employed in the fabrication of the end-cap and thus facilitated assembly as compared to using an end-cap whose inner diameter was friction-fitted to tightly embrace the metallic ferrule, the assembly operation remained a somewhat tedious hand operation requiring the lighting maintenance personnel to manually put together the elements of the fluorescent lamp protection assembly in the field rather than merely replacing burned-out lamps. It would be advantageous to eliminate the need for field assembly as well as to provide a more reliable encapsulation method.
SUMMARY OF THE INVENTION
In accordance with the principles of the present invention, as exemplified by the illustrative embodiment, a shatterproof fluorescent lamp assembly is achieved capable of containing within a polymeric envelope all of the glass, powders and mercury used in the lamp without the need for separate, hand-assembled tubes and end-caps. Instead of manually fitting together end caps to a length of pre-cut, cylindrical tubing, a protective polymeric coating, advantageously a polycarbonate, is extruded directly on to the fluorescent lamp so as to be in intimately conforming contact with substantially all of the contours of the lamp's glass envelope and metallic ferrules. The lamp is passed through an air lock into the main lumen bore of an extruder crosshead which is connected to vacuum pump. A cylinder of hot, polymeric material is extruded and radially drawn inward toward the periphery of the lamp by the vacuum. The extruded cylinder should have a wall thickness, so that when cooled, it will exhibit sufficient beam strength to maintain the cylindrical shape even if the glass envelope of the fluorescent tube is shattered.
Prior to inserting the fluorescent lamp into the crosshead, a short length of easily removable silicone tubing is fitted over the electrical terminals at each end of the lamp to protect the terminals from being permanently coated with any plastic.so. According to one embodiment, the metallic ferrules of the lamp are pre-coated with an adhesive which, advantageously, may be a heat-activated adhesive. According to another embodiment, instead of using an adhesive, each end of the lamp is heated and then immersed in an air-fluidized bed of powdered ethylene vinyl acetate to pre-coat the metallic ferrules of the lamp. In either case, the lamp is then put through the extruder crosshead to receive the cylindrical sheath which adheres to the pre-coated portions of the lamp ends. Advantageously, as the trailing end of the first fluorescent lamp enters the crosshead, a second fluorescent lamp is inserted so as to make the process continuous for a number of successive lamps. At a convenient distance downstream from the crosshead, power driven rollers move the encapsulated lamp to a first cutting position where the extrudate between successive lamp ends is sheared, separating the encapsulated lamps from one another. A second cutting operation cuts the extrudate at the end of the lamp ferrule to facilitate removal of the silicone tubing covering the electrical terminals. The coated, shatterproofed lamps may then be packed for shipment. By immersing the lamp ends in the air-fluidized bed of powdered plastic to which the extrudate adheres, the ends as well as the glass envelope of the fluorescent lamp are substantially completely encapsulated.
BRIEF DESCRIPTION OF THE DRAWING
The foregoing objects and features of the present invention may become more apparent from a reading of the ensuing description, together with the drawing, in which:
FIG. 1 is an overall view showing the encapsulation method of the invention;
FIG. 2 shows a section through a sequence of encapsulated fluorescent lamps after passing through the crosshead apparatus of FIG. 1, but prior to the sequence of encapsulated lamps being cut apart;
FIG. 3 shows an enlarged view of the end of an encapsulated fluorescent lamp after separation and removal of the temporary protective tubing from the electrical terminals;
FIG. 4 show a section through the air lock of the crosshead;
FIG. 5 shows the rollers of the air lock;
FIG. 6 shows the air lock seal of the crosshead;
FIG. 7 shows the end of a fluorescent lamp immersed in an air-fluidized bed of powdered plastic to provide a coating to which the extrudate will adhere;
FIG. 8 shows the lamps which have been treated in FIG. 7 after emerging from the extruder crosshead; and
FIG. 9 shows the lamp end after the silicone protective sleeve has been removed.
DESCRIPTION
In FIG. 1, a conventional, commercially available fluorescent lamp 10 is depicted during its passage through the encapsulating apparatus of the invention. Lamp 10 includes an elongated glass tube 12 that necks down slightly at each end to engage a metallic ferrule 15 . Fluorescent lamps are conventionally equipped with either a single electrical terminal or, as shown, a pair of electrical terminals 18 , 18 ′ at each end.
As shown in my previous patent, the prior art the practice was to enclose the glass tube portion 12 of the fluorescent lamp 10 within a larger diameter sleeve made of a semi-rigid, nonfrangible transparent tubing of polymeric material. The protective sleeve was secured to the ferrules 15 by means of rubber end caps that were frictionally fit over the cups. In the prior art it was always thought to be necessary to have the diameter of the protective sleeve larger than the outside diameter of the glass envelope not only to facilitate assembly, but also to provide an “air gap” for various purposes. In accordance with the invention, there is no need for such an air gap, and no need for end caps and a hand fitting and assembly operation to be performed in the field. Instead, referring to FIG. 1 (not drawn to scale), plastic is extruded over fluorescent lamp 10 to encapsulate the lamp as it passes through crosshead 20 connected to a screw extruder 30 .
Prior to introducing lamp 10 into crosshead 20 , an adhesive 19 is applied to the circumference of the metallic ferrules 15 , 15 ′ at each end of the lamp. Advantageously, the adhesive may be applied to lap over a small portion of the end wall of the ferrule. Then the lamp is introduced into cross-head 20 through an air lock which advantageously includes a stage of feed-through rollers 22 and an air seal 23 (shown in fuller detail in FIGS. 5 and 6 respectively). As lamp 10 passes through crosshead 20 , extruder 30 injects molten thermoplastic material 31 under pressure into the annular space 24 between crosshead parts 25 and 26 . A cylinder of hot, plastic material 32 is extruded from crosshead 20 . At the same time, vacuum is applied to ports 27 leading to the main bore 28 of the crosshead. Because of the sealing action of air lock 22 , 23 , the vacuum causes the extruded cylinder of hot, plastic material 32 to be drawn radially inward into intimately conforming contact with the outer surfaces of lamp 10 . In sequence, as the short length of protective tubing 14 ′ exits crosshead 20 it is first contacted by the inwardly drawn extruded material 32 , bonding thereto. Next, ferrule 15 ′, glass envelope 12 , ferrules 15 and, finally, the short length of protective tubing 14 are encapsulated as they exit bore 28 of extruder crosshead 20 . The heat of the plastic material 32 emerging from crosshead 20 activates adhesive 19 aiding the adhesion of the extruded material to ferrules 15 ′ and 15 .
As soon as the trailing end of a first lamp 10 - 1 is processed in crosshead 20 , it is advantageous to introduce a second lamp 10 - 2 into crosshead 20 through air lock 22 , 23 so that it can be encapsulated in similar fashion to the first lamp in a continuous extrusion process wherein a sequence of encapsulated lamps follow one another from the extruder crosshead. At a convenient distance downstream from crosshead 20 a set of power driven take-up rolls 50 grasps the encapsulated lamp 10 - 1 , drawing it away from the extruder and, to some extent, causing some thinning of the wall thickness of the extruded material at the ends of the lamp, as shown more clearly in the enlarged views of FIGS. 2 and 3. Thereafter, the sequence of encapsulated lamps is cut apart. Advantageously, this is done in two steps. In the first step, as shown in FIG. 2, the encapsulating sleeve 32 is cut between successive lamps 10 - 1 and 10 - 2 along the line “cut—cut”. At this point a lamp still has its electrical contacts covered by the short lengths of protective tubing 14 , 14 ′. In the second step, the wall thicknesses of the encapsulating sleeve 32 is cut through between the end of each ferrule 15 , 15 ′ and the end of the respective protective tubing 14 , 14 ′ so that the protective tubing 14 , 14 ′ can be removed from each end of lamp 10 . FIG. 3 shows the encapsulated lamp 10 with the protective tubing 14 removed. Note that coating 32 intimately embraces the various contours of lamp 10 at points 32 a , 32 b , 32 c and 32 d thereby providing complete containment for all of the lamps internal components should its glass envelope 12 be broken. At this point the encapsulated lamp may be packed and shipped to the field where it may be installed without any additional labor being required.
FIGS. 4, 5 and 6 show details of the air lock 22 , 23 at the input end of crosshead 20 through which fluorescent lamps are introduced for encapsulation. An array of rollers 22 r is provided to help axially align the lamp 10 with the internal bore of 28 of the crosshead. Rollers 22 r are advantageously made of rubber like material to assist in guiding the glass envelope 12 of lamp 10 through the crosshead. Rollers 22 r may advantageously be power driven. An air seal 22 having one or more sealing rings 22 sr whose inner diameter is made slightly smaller than the outer diameter of the glass envelope 12 to minimize air leakage into the bore 28 of the crosshead.
Referring now to FIGS. 7 through 9 an alternative process for encapsulating fluorescent lamps is disclosed. First, a protective silicone sleeve 14 is slipped over the electrical terminals of the lamp. Then a short length at the ends of each lamp 10 is heated, advantageously by being exposed to an infra-red heat source (not shown). The heated end portion of the lamp should embrace the end ferrule 16 and a short length of the glass envelope 12 . The heated end portion is then immersed in a container 70 containing an air stone 71 and a quantity of plastic powder, advantageously ethylene vinyl acetate which has been freeze dried and ground into powder. Air stone 71 may advantageously be similar to the type often employed in aquariums. Air stone 71 is connected to an air supply (not shown) to produce upwardly directed air streams 72 that turn the plastic powder into a cloud or air-fluidized plastic bed 73 . The air-fluidized powder adheres to the heated lamp end thereby providing a pre-coating 75 a , 75 b and 75 c . Portion 75 a adheres to the end portion of glass tube 12 , portion 75 b adheres to the ferrule 16 and portion 75 c adheres to the transverse part of the terminal-bearing portion of the lamp.
The pre-coated lamp end is then inserted into the crosshead of the extruder to receive the extruded main cylindrical coating 32 , as described above. Referring to FIG. 8, portion 32 a of the extruded coating adheres to the cylindrical portion of glass envelope 12 . Portion 32 b of the extruded coating adheres to the transitional portion of the glass envelope 12 which has now been coated with coating 75 a . Similarly, Portion 32 c of the extruded coating now adheres to the precoated ferrule portions 75 b of lamp 10 .
As described above, after a first lamp 10 - 1 has exited the crosshead, a second lamp 10 - 2 , also having its ends precoated with coating 75 , may advantageously be inserted into the crosshead. FIG. 8 show a succession of lamps 10 - 1 , 10 - 2 encapsulated by coating 32 , after having exited the extruder. FIG. 9 shows a lamp end after the coating 32 between successive lamps 10 - 1 and 10 - 2 has been sheared and after the protective silicone sleeves 14 have been removed. Coating 32 is then trimmed at the “cut” lines shown in FIG. 8 . This embodiment of the invention has the advantage that the extrudate 32 and pre-coating 75 adhering to each other, especially at point 32 c and 75 c , provide a more complete encapsulation of the lamp 10 .
The foregoing is deemed to be illustrative of the principles of the invention. It should be apparent that the polymeric extrudate 32 may be made of polyethylene, acrylic, PETG, polycarbonate or any other similar material with a wall thickness affording sufficient beam strength to retain its cylindrical shape should the glass envelope be fractured. In particular, it should be noted that while fluorescent lamps are no longer manufactured in a variety of colors because of environmental concerns caused by the metallic compounds used in some colored fluorescent powders, such powders may safely be incorporated in the extrudate since they are completely encapsulated in the plastic coating itself Accordingly, a variety of differently colored plastic envelopes may be extruded over a white fluorescent lamp. In one illustrative embodiment, the polymeric coating 32 , as shown in FIG. 3, had a wall thickness 32 of approximately 0.0151″, a wall thickness 32 b of approximately 0.016″ and a wall thickness 32 c at the end of ferrule 15 of approximately 0.006″. It should be appreciated that the interior diameter of protective tubing 14 should fit snugly over contacts 18 and that the end of tubing 14 may be spaced apart from the end wall of the ferrule to facilitate cutting through of the extrudate 32 . Further and other modifications maybe made by those skilled in the art without, however, departing from the spirit and scope of the invention.
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A compact and portable docking station for a radio mobile personal digital assistant (PDA) carries a magnetic card reader and provides an interface that supplies drive power to the magnetic card reader independently of the PDA battery and translates signal levels provided from the card reader so that they can reliably be read by the PDA. PDA battery power is conserved by initiating all interface actions from a software generated “radio” button appearing on the screen of the PDA.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. Provisional Application No. 61/676,673, filed Jul. 27, 2012, which is hereby incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The disclosure relates to a method and apparatus for improving the accuracy of delivery of charged-particle beams for the treatment of cancer. The disclosure also includes an improved method for performing quality-assurance measurements on charged-particle beams used in therapy.
BACKGROUND
[0003] Charged-particle beams are among the most advanced methods currently available for the treatment of cancer tumors by radiotherapy. The more common charged-particle beam therapy centers use protons as the particle of choice, while a few centers have begun using heavy ion particles such as carbon ion beams.
[0004] The specific advantage of charged-particle beam therapy in treating tumors is the physical effect known as the “Bragg peak.” The Bragg peak is a sharp increase in delivered dose, which occurs near the end of a particle trajectory in the patient. The physical characteristics of the Bragg peak make it possible, in principle, to more carefully conform the particle-beam to the shape of the tumor. In addition, since there is very little beam intensity beyond the range of the Bragg peak, there can be significant reduction in overall radiation dose to normal tissue, as compared to photon external beam radiotherapy.
[0005] In order to make use of narrow tumor margins that are possible in principle with charged particle beams, it is necessary to have an accurate knowledge of the beam penetration in the patient. The current practice is to infer the penetration of charged particles, based on information gathered from x-ray imagery, particularly computed tomography (CT). However, there are well-known problems with making the extrapolation from CT imagery to the expected penetration of charged particle beams, which leads to an uncertainty in the knowledge of the beam penetration in the actual patient. In addition, the patient anatomy can change over time, leading to changes in the actual penetration of the charged particle beam from one treatment to the next, further leading to uncertainty in the knowledge of the actual delivered dose to tumor and to normal tissue.
SUMMARY
[0006] The disclosed systems, methods, and devices address the uncertainty in beam location by providing a means to determine particle beam penetration in a patient during the time frame of a daily treatment. The disclosed systems, methods, and devices may also be used to determine the charged particle beam penetration in phantoms constructed from materials chosen to mimic the behavior of human tissue when exposed to radiation, often called “water-equivalent” materials. The disclosed systems, methods, and devices improve the accuracy of determination of charged particle beam penetration in patients. The disclosed apparatus and methods also apply to the calibration of charged particle beams for therapeutic use. This disclosure applies to all charged-particle beam therapies for treating cancer.
[0007] Disclosed are a system, method, and apparatus that provide information about the trajectory of a charged particle beam as it traverses a patient undergoing external beam therapy. Although the present embodiment primarily addresses proton beam therapy, it is also applicable to other charged particle beams, and specifically to carbon atom beams.
[0008] A method is disclosed for determining charged-particle beam trajectories through the use of a variation of the charged-particle beam energy as a function of time, and measurement of the yield of fluorescent radiation from fiducial markers as a function of time, and application of an algorithm to extract information on the beam trajectory. A “fiducial marker” as used herein includes any material with a known composition that is placed at a known location. In particular, the fiducial marker can contain a material with x-ray fluorescence.
[0009] Also disclosed is a method to use a charged-particle beam in a way that is compatible with its use for patient therapy. The charged-particle beam excites atomic electrons in all of the materials along the charged-particle beam path. These excited electrons leave behind an atom in an excited energy state, which is de-excited through a number of processes. One of the processes is the production of fluorescent x-rays.
[0010] The method detects these fluorescent x-rays, and uses the intensity of the fluorescence, along with other information, to determine the trajectory of the charged-particle beam in the patient. The energy of the fluorescent x-ray can be selected such that the x-ray can readily pass through the patient's tissue and reach the detector. For example, the energy of the fluorescent x-ray can be at least 20 keV (e.g., at least 30 keV, at least 40 keV, at least 50 keV, at least 60 keV, at least 70 keV, at least 80 keV, at least 90 keV, at least 100 keV, at least 110 keV, at least 120 keV, at least 130 keV, or at least 140 keV). In some embodiments, the energy of the fluorescent x-ray can be 150 keV or less (e.g., 140 keV or less, 130 keV or less, 120 keV or less, 110 keV or less, 100 keV or less, 90 keV or less, 80 keV or less, 70 keV or less, 60 keV or less, 50 keV or less, 40 keV or less, or 30 keV or less). The energy of the fluorescent x-ray can range from any of the minimum energies described above to any of the maximum energies described above. For example, the energy of the fluorescent x-ray can range from 20 keV to 150 keV (e.g., from 20-40 keV, from 40-50 keV, from 50-60 keV, from 60-80 keV, or from 60-90 keV).
[0011] By using fluorescent x-rays, the method takes advantage of the narrow line-width and high detection efficiency of x-rays of atomic origin. The line-width of the fluorescent x-ray can be sufficiently narrow, such that the fluorescent x-ray can be readily detected without interference from a wide range of x-rays from other processes that do not provide beam position information. Suitable line-widths for the fluorescent x-ray line-width can be selected in view of the detector or detectors configured to measure the fluorescent x-ray. For example, the line-width of fluorescence x-rays can be approximately 100 eV for high-resolution solid-state detectors, or a few hundred eV for proportional counters. In certain embodiments, the line-width of the fluorescent x-ray is 1 keV or less (e.g., 900 eV or less, 800 eV or less, 700 eV or less, 600 eV or less, 500 eV or less, 400 eV or less, 300 eV or less, 300 eV or less, or 100 eV or less). The line-width of the fluorescent x-ray can be sufficiently narrow to permit the separation of lines from different elements and/or different inner-shell atomic energy levels, such as the K and L shell of the element gold (Au).
[0012] A number of materials can be selected to create fiducial markers that will produce fluorescent x-rays that will pass through the body with low attenuation but have a high detection efficiency. The fluorescent x-ray is produced by atomic de-excitation. The chemical element used as a fiducial marker can be selected to be compatible with human use and with radiotherapy. In some embodiments, the method uses gold (Au) fiducial markers, which produce K-shell fluorescent x-rays of an energy and line-width of 60-80 keV, which is suitable for detection during clinical procedures. Other atomic elements can also produce suitable x-rays, and the use of these other elements is included in the scope of the invention. Suitable materials for producing these fluorescent x-rays include materials used commonly in medicine and as contrast agents, including gold (Au), gadolinium (Gd, with K shell transition radiation in the range of 42-50 keV), iridium (Ir, with K shell transition radiation in the range of 63-76 keV), iodine (I, with K shell transition radiation in the range of 28-33 keV), xenon (Xe, with K shell transition radiation in the range of 29-33 keV), barium (Ba, with K shell transition radiation in the range of 32-36 keV), lanthanum (La, with K shell transition radiation in the range of 33-38 keV), samarium (Sm, with K shell transition radiation in the range of 40-45 keV), europium (Eu, with K shell transition radiation in the range of 41-47 keV), terbium (Tb, with K shell transition radiation in the range of 44-50 keV), erbium (Er, with K shell transition radiation in the range of 48-56 keV), thulium (Tm, with K shell transition radiation in the range of 50-58 keV), lutetium (Lu, with K shell transition radiation in the range of 53-61 keV), tungsten (W, with K shell transition radiation in the range of 58-67 keV), rhenium (Re, with K shell transition radiation in the range of 58-69 keV), osmium (Os, with K shell transition radiation in the range of 61-71 keV), and Platinum (Pt, with K shell transition radiation in the range of 65-76 keV).
[0013] The method uses a known position of fiducial markers to identify the emission location of fluorescent x-rays. Implanted fiducial markers are common in radiotherapy, and specific examples are for prostate therapy and lung therapy. However, implanted fiducials can be used in many other areas of the body for other types of cancer treatment, and these uses are included herein.
[0014] Fiducial markers are typically located by performing a computed-tomography (CT) scan of the patient, which can also be used with the disclosed methods. However, other means to locate fiducial markers that can be used in the disclosed methods include high resolution sonography, radiography, and RF emission from markers with transmitters.
[0015] Fiducial markers can take different physical forms, including metallic wires, helical coils, and surgical clips. For example, fiducial markers commonly used in medical practice for marking tumor locations, such as the Visicoil™ product and surgical clips made from gold can be used. In addition to these common fiducial markers, the method incorporates the use of other suitable classes of fiducial markers which contain x-ray fluorescent atoms, such as nanoparticles, metal-conjugated proteins, and imaging contrast agents. For example, fiducial markers may also take the form of injected liquids containing atoms that fluoresce in the energy ranges described above (e.g., emit a fluorescent x-ray having an energy of from 20-150 keV). Examples of such injectable fiducial markers includes nanoparticles formed from a suitable x-ray fluorescing material (e.g., gold nanoparticles, gadolinium nanoparticles, gold-gadolinium nanoparticles, core-shell nanoparticles containing a suitable x-ray fluorescing material in the core and a shell formed from a passivating material such as a polymer), microcontainers encapsulating a solution of a suitable x-ray fluorescing material (e.g., polymer tubes or capsules filled with, for example, a gadolinium solution), and radium containing radiopharmaceuticals.
[0016] The method uses a particular protocol for delivering the particle beam at any time prior to, during, or after treatment of a patient, in order to determine the trajectory of the beam within the patient. The particle beam is delivered with a known beam energy, which is varied, while measuring fluorescence emission from implanted fiducial marker(s) in synchrony with the variation of the beam energy. The variation of the beam energy produces a change in the depth of penetration of the charged particle beam, which is reflected in a variation of the detected fluorescence emission.
[0017] In some embodiments, the method involves the detection of an x-ray of a single energy. Attenuation of the emitted fluorescent beam can in some embodiments be affected by variations in the patient's body thickness and composition, which may not be independently determinable. Therefore, in other embodiments, the method uses the simultaneous detection of x-rays of two or more different energies. These x-rays originate at the same location in the patient. Since the x-rays have two different energies, they will travel through the patient's body with different levels of attenuation. The two (or more) x-ray energies will be detected by an energy selective x-ray detector. A suitable method for this detection is a pulse-height analysis system, such as a silicon or germanium detector, or in some cases, a scintillation counter system. Other methods of detecting the number of x-rays emitted within each energy channel are known, and may be used in the disclosed systems, methods, and devices.
[0018] By simultaneously detecting x-rays of more than one energy, it is possible to determine the ratio of the intensity of these beams that are detected. The method will work with two or more beams. In some embodiments, the K-α (near 80 keV, also called KN radiation) and K-β shell fluorescence (near 68 keV, also called KL radiation) from Au (gold) fiducials is used. However, other materials are suitable for this purpose, including in certain cases materials that occur naturally in the human body. Materials commonly used in medicine such as gadolinium, iodine, iridium, and radium have suitable energy levels that are separated by several keV and can be distinguished by suitable detectors, including solid-state detectors.
[0019] Both of the x-ray beams, e.g., K-α and K-β, pass through the same regions of the patient. Each individually experiences intensity attenuation that is a function of the energy of the x-ray beam. The energy of the beam is measured. The energy of the x-ray beam identifies the type of the beam, e.g., that it is a K-α or an K-β shell beam. With the knowledge of the type of beam, e.g., K-α or K-β shell, the ratio of the intensity of these beams can then be used to determine the attenuation thickness of the patient that the beams have traversed. This is accomplished by using a formula for x-ray attenuation based on an exponential function, in which the effective thickness of the material traversed is multiplied by the attenuation coefficient for the specific beam, e.g., the K-α or K-β shell. The attenuation coefficients can either be taken from widely known tabulated information, or determined more specifically by measurements on so-called “phantom” materials selected to mimic human tissue. The relative intensity of the beams is used with the knowledge of the exponential attenuation law to correct the information of x-ray intensity that is used to determine the proton energy and range.
[0020] The disclosed method can incorporate an algorithm for determining particle beam trajectory based on the synchronous variation of incident particle beam energy and fluorescence emission intensity. The disclosed method may also be used to adapt a therapeutic particle-beam therapy based on information revealed by application of the disclosed method, so as to improve the conformality of the particle-beam and the tumor being treated.
[0021] Energy detectors (e.g., multi-energy detectors) may be arranged at various locations around the patient to increase the number of beams that are measured, thereby reducing the time needed to complete a measurement, and to increase the accuracy of the measurement. Fluorescence x-rays may also be measured over a substantial part of the spherical solid-angle surrounding the fiducial markers using wide-angle detectors, so as to increase signal detection efficiency and reduce patient dose. As a beneficial alternative, the method allows for the use of collimated detectors in an angular arrangement, so as to determine the location of emission of fluorescence x-rays without the need for other determination of their position.
[0022] An apparatus and system are disclosed that comprise a source of charged-particles with an energy that can be varied as a function of time, fiducial markers with a constituent material that produces a fluorescence signal suitable for detection at a distance removed from the treatment field, an arrangement of detectors to measure the fluorescence signal as a function of time, and suitable computer control and electronic equipment to implement the method and apply the disclosed algorithm to extract and display information on the charged-particle beam trajectory.
[0023] The apparatus and system can incorporate a therapeutic charged-particle beam with an energy that is varied. Typically this is accomplished with a “modulation wheel”, also called a “propeller”. Implanted fiducial markers containing a high density of atoms of the desired element to produce fluorescence x-rays may be placed in or near the tumor treatment location. Fluorescence detectors may be arranged outside the patient so as to be outside the path of the incident particle beam, but are otherwise located close to the patient's skin surface to enhance signal detection.
[0024] Fluorescence signals may be measured from the detectors, and selected according to their energy using pulse-height discrimination techniques. The energy of fluorescence can be determined by the element used in the fiducial implant. This energy may be high enough so that large numbers of x-rays are transmitted outside the patient. By using fiducial markers of the heavy element gold (Au), the marker is compatible with clinical use, and the fluorescence x-ray is well-separated from other sources of background radiation.
[0025] A computer system can be used to record the intensity of emitted x-rays while monitoring the energy of the incident particle beam. An algorithm, e.g., derived from Monte-Carlo simulations, can be used to extract beam trajectory from the measured emission intensity patterns.
[0026] An imaging detection system may be used to create a spatial map of the location of the emitted fluorescent x-rays, so as to more accurately determine the location of protons that create the fluorescence. This spatial imaging detection system may be capable of sorting fluorescent x-rays according to their energy, and to use this information for attenuation correction as described above.
[0027] Also disclosed are method of treating cancer in a subject that involve implanting fiducial markers in or near the cancer, determining charged-particle beam trajectories through the use of a variation of the charged-particle beam energy as a function of time, measurement of the yield of fluorescent radiation from the fiducial markers as a function of time, using an algorithm to optimize beam trajectory, and using the optimized charged-particle beam to irradiate the cancer. Any cancer, e.g., solid tumor, that can be treated by charged-particle beam radiotherapy can be treated by this optimized method. For example, the cancer can be lung, prostate, breast, skull base tumors, or uveal melanomas.
[0028] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0029] FIG. 1 is a schematic view of an apparatus according to an embodiment of the invention.
[0030] FIG. 2 is a table illustrating steps of a method in accordance with an embodiment of the current invention.
[0031] FIG. 3 contains a top graph of model variations of the charged particle beam as a function of time and a bottom graph of the fluorescence yield as a function of time, showing the response of the fiducial marker in accordance with an embodiment of the invention.
[0032] FIG. 4 is a schematic of an experimental design to determine whether proton-induced x-ray fluorescence can be utilized to determine clinically important dosimetric parameters during a proton therapy treatment.
[0033] FIG. 5 is a graph showing pulse height analysis of proton induced Au fiducial x-ray emission (counts as a function of energy, keV).
[0034] FIG. 6 is a graph showing analytical model of the experiment using Bragg curve approximations with stopping power parameters for Au adapted from NIST data tables (fluorescence as a function of path length, cm).
DETAILED DESCRIPTION
[0035] In the following description, reference is made to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific examples or processes in which the invention may be practiced. Where possible, the same reference numbers are used throughout the drawings to refer to the same or like components. In some instances, numerous specific details are set forth in order to provide a thorough understanding of the invention. The invention, however, may be practiced without the specific details or with certain alternative equivalent devices and/or components and methods to those described herein. In other instances, well-known methods and devices and/or components have not been described in detail so as not to unnecessarily obscure aspects of the invention. For the sake of clarity, the various elements represented in the figures are not necessarily to scale.
[0036] FIG. 1 is a schematic of one embodiment of the disclosed apparatus. A source of high energy charged particles 103 produces a beam of particles 106 , which is directed at a target 101 . In a preferred embodiment, the charged particles are protons with energy ranging from 50 MeV to 250 MeV, but other charged particles and energy ranges may be used. For example, the method is suited to be used with helium and carbon atom particle beams, both of which are used in practice for medical treatment.
[0037] The target 101 contains one or more, e.g., plurality, of fiducial markers 102 which are placed at fixed locations within the target. In the embodiment in which the target is a patient, these fiducial markers may preferably be clinically approved seeds manufactured from gold, with dimensions of approximately 1 mm diameter, as commonly used for prostate implant radiotherapy. One example type of suitable gold fiducial marker is the Visicoil™, which can range in diameter from 0.35 mm to 1.10 mm and length from 0.5 cm to 3 cm. Other suitable markers include gold markers used to define tumor locations with the Cyberknife™ radiosurgery system (wherein the gold markers are 0.8 mm×5 mm in size), and surgical clips used to mark tumor boundaries.
[0038] In the embodiment in which the target is a phantom, the fiducial markers may also be composed of gold wire, with preferable dimensions of 1 mm diameter by 5 mm length.
[0039] The incident charged particle beam may be directed towards the target and the fiducial markers, with an energy that changes as a function of time in a known way. The control of particle beam energy is a requirement of particle radiotherapy, and the means to accomplish this are well known to practitioners of the art.
[0040] When the energy of the particle beam 106 is sufficiently high enough, the Bragg peak will approach the location of the fiducial markers 102 , which will begin to produce fluorescence radiation 104 .
[0041] The fluorescent radiation emitted by the fiducial markers contains one or more identifiable core-level x-ray emission peak characteristic of the atomic composition of the fiducial. In some embodiments, a major elemental component of the fiducial marker is gold (Au), which emits K shell fluorescent x-rays in the range of approximately 68-80 keV, which are sufficient to travel through the target to reach the detectors 105 without excessive attenuation. In some embodiments, both K and L shell fluorescence from Au (gold) fiducials is used.
[0042] The fluorescent radiation 104 is not directed into any specific direction. To efficiently collect the radiation, a plurality of x-ray detectors 105 (e.g., multi-energy detectors) can be arranged around the target. In FIG. 1 three such detectors are shown, but more or fewer detectors can be used.
[0043] In some embodiments the detector 105 is a scintillation detector, but other detectors of x-ray radiation are known to practitioners skilled in the art and can be used herein. These include solid state energy dispersive detectors, commonly called silicon (Si) and germanium (Ge) detectors, proportional counters, gas-electron multiplier detectors, energy-dispersive detectors, and wavelength dispersive detectors.
[0044] The detector 105 produces one or more electrical signals whose amplitude is proportional to the energy of the x-ray 104 that reaches the detector. To enhance the signal-to-noise ratio, pulse-height analysis may be used on the detector signal to isolate the signal from the x-rays originating from the fiducial markers. The fiducial markers produce characteristic x-rays which are sufficiently far from the x-rays produced by other materials in the patient or the phantom, that there is little interference to the desired fiducial signal from other materials.
[0045] FIG. 2 is a diagram illustrating steps of one embodiment of the disclosed methods. The method can begin with the implantation of fiducial markers in the target, 201 . In some embodiments, the target is either a patient, or a phantom selected for quality-assurance of the charged-particle treatment beam 103 - 106 . In the embodiment in which the target is a patient, the fiducial markers may be similar to those already in clinical use for treatment of prostate cancer or lung cancer.
[0046] The location of the fiducial markers is identified in the next step of the method, 202 . In the case in which the target is a phantom, the location of the markers may be accomplished by the construction of the phantom, or by optical means, or other means well-known to those practiced in the art. In the case in which the target is a patient, the fiducial markers by be localized using an x-ray computed-tomography (CT) scan. Other methods of localizing the fiducial markers, such as radiography, radio-frequency emitters coupled to fiducials, magnetic resonance imaging, or ultrasound, may also be used.
[0047] The particle beam 106 may be prepared at a specific energy, and directed at the target, step 203 . The yield of fiducial marker fluorescence x-rays can be measured 204 and recorded. Optionally, two or more fluorescent energies are detected to correct for attenuation as described above. The energy of the beam 106 can be incremented, resulting in a stepwise variation of the beam energy with time, with the precise relationship of time and beam energy being known. The beam energy can be compared to the desired endpoint, 205 , and the cycle of measurement of x-rays and incrementing beam energy ( 203 , 204 , 205 ) can be repeated until the entire range of particle energies is scanned.
[0048] An algorithm 206 can be applied to the measured fluorescence data as a function of time, to determine the precise time at which the particle beam reached the known location of the fiducial markers. This time in turn can be converted into a beam energy, which was recorded in steps 203 - 205 .
[0049] In some embodiments, the algorithm used to process the fluorescence data is based on accurate measurements made with proton beams and fiducial markers in a water-equivalent phantom. From this measurement, a profile can be determined that represents the intensity distribution of fluorescence from the fiducial as the Bragg peak sweeps across the fiducial marker. The specific point in the profile that represents the location of the fiducial can thus be accurately determined. This information can be used by the algorithm to extract the location of the particle beam Bragg peak in the target from the measured intensity of fluorescence x-rays as a function of time.
[0050] As an illustration of the process of the algorithm, FIG. 3 ( 301 ) shows a model graph (top) of the variation of the charged particle-beam energy as a function of time, exhibiting a monotonically increasing behavior. The energy of the beam is known at any time. The emitted fluorescence yield from a single fiducial marker is illustrated in the bottom graph of FIG. 3 ( 302 ). An edge-like structure occurs at the location of the time t* ( 303 ), highlighted by the vertical dashed line. The shape of the edge structure is analyzed to determine the precise time, t*, which corresponds to the particle beam Bragg peak maximum encountering the fiducial marker. Since time also determines beam energy ( 301 ), it is then known at which beam energy the particle beam strikes the fiducials.
[0051] The results of the algorithm are presented in a suitable form in the final step of the method 207 . Specific parts, shapes, materials, functions and modules have been set forth, herein. However, a skilled practitioner will realize that there are many ways to fabricate the disclosed system, and that there are many parts, components, modules or functions that may be substituted for those listed above.
[0052] Also disclosed are method of treating a tumor in a subject that involve implanting fiducial markers in or near the cancer, determining charged-particle beam trajectories through the use of a variation of the charged-particle beam energy as a function of time, measurement of the yield of fluorescent radiation from the fiducial markers as a function of time, using an algorithm to optimize beam trajectory, and using the optimized charged-particle beam to irradiate the cancer. Any tumor, e.g., cancer, that can be treated by charged-particle beam radiotherapy can be treated by this optimized method. For example, the cancer can be lung, prostate, breast, skull base tumors, or uveal melanomas. In some embodiments, the fiducial markers are placed at around the tumor margins, at one or more locations inside the tumor, or a combination thereof.
[0053] The term “subject” refers to any individual who is the target of administration or treatment. The subject can be a vertebrate, for example, a mammal. Thus, the subject can be a human or veterinary patient. The term “patient” refers to a subject under the treatment of a clinician, e.g., physician.
[0054] The term “treatment” refers to the medical management of a patient with the intent to cure, ameliorate, stabilize, or prevent a disease, pathological condition, or disorder. This term includes active treatment, that is, treatment directed specifically toward the improvement of a disease, pathological condition, or disorder, and also includes causal treatment, that is, treatment directed toward removal of the cause of the associated disease, pathological condition, or disorder. In addition, this term includes palliative treatment, that is, treatment designed for the relief of symptoms rather than the curing of the disease, pathological condition, or disorder; preventative treatment, that is, treatment directed to minimizing or partially or completely inhibiting the development of the associated disease, pathological condition, or disorder; and supportive treatment, that is, treatment employed to supplement another specific therapy directed toward the improvement of the associated disease, pathological condition, or disorder.
[0055] The term “tumor” or “neoplasm” refers to an abnormal mass of tissue containing neoplastic cells. Neoplasms and tumors may be benign, premalignant, or malignant. The term “cancer” refers to a cell that displays uncontrolled growth, invasion upon adjacent tissues, and often metastasis to other locations of the body.
[0056] While the above detailed description has shown, described, and pointed out the fundamental novel features of the invention as applied to various embodiments, it will be understood that various omissions and substitutions and changes in the form and details of the components illustrated may be made by those skilled in the art, without departing from the spirit or essential characteristics of the invention.
EXAMPLES
Example 1
Proton Induced X-Ray Fluorescence for In-Vivo Determination of Proton Range and Energy
[0057] FIG. 4 illustrates the experimental design used to determine whether proton-induced x-ray fluorescence can be utilized to determine clinically important dosimetric parameters during a proton therapy treatment.
[0058] Measurements. Therapeutic beams from the UF Proton Therapy Institute were used to excite proton induced x-ray fluorescence emission (PIXE) from cylindrical pure gold fiducial markers. The markers were embedded in a homogeneous water phantom and PIXE was measured using NaI scintillators with energy dispersive spectral analysis. The geometry of the phantom and marker placement was chosen to model parallel-opposed beam treatment of prostate cancer by proton therapy.
[0059] Modelling. An analytical model of fluroescence yield in realistic therapy conditions was developed using semi-empirical Au K and L shell cross-sections for proton induced emission, and attenuation data for both xray channels. The fluorescence yield from these markers was further modeled using the GEANT4 Monte-Carlo package with low-energy corrections.
[0060] Measurements were made with proton beam maximum energy ranging from 80 MeV to 200 MeV. The pure gold fiducial was placed at a fixed depth in a water tank. The gold K and L shell x-rays passed through 13.5 cm of water and the wall of the acrylic tank before reaching a 2 cm diameter NaI scintillator where they were detected and energy scaled using pulse height analysis ( FIG. 5 ).
[0061] Backgrounds were taken with no beam and no gold sample, and with a proton beam but no gold sample. The pulse-height analysis spectrum was accumulated in a multichannel analyzer, and calibrated using a Cs-137 source.
[0062] An analytical model of the experiment was developed using the Bragg curve approximations of Bortfeld [Med. Phys. 24 (1997) 2024-2033] with stopping power parameters for Au adapted from NIST data tables ( FIG. 6 ). The model incorporates range straggling and energy spread, and fluence reduction due to inelastic nuclear events, using a parameterization to fit data of Janni [At. Data Nucl. Data Tables 27 (1982) 147-339].
[0063] PIXE from gold fiducial markers was readily detected above background using conventional NaI-T1 scintillation detectors, in a clinical therapy proton beam. This work shows the feasibility of using PIXE for in-vivo dosimetry with proton therapy.
[0064] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.
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The accuracy charged-particle beam trajectories used for radiation therapy in patients is improved by providing feedback on the beam location within a patient's body or a quality assurance phantom. Particle beams impinge on a patient or phantom in an arrangement designed to deliver radiation dose to a tumor, while avoiding as much normal tissue as can be achieved. By placing fiducial markers in the tumor or phantom that contain specific atomic constituents, a detection signal consisting of atomic fluorescence is produced by the particle beam. An algorithm can combine the detected fluorescence signal with the known location of the fiducial markers to determine the location of the particle beam in the patient or phantom.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to production and a preprocessing system for analysis of large-scale data.
[0003] 2. Prior Art
[0004] Recent years, as the entire human gene information has been discovered, there has been accumulated enormous array information, experimental data or document information, which is for use in genome analysis projects for a human being and other various creatures. Henceforth, therapy taking individual genes as an object, which is reflected on diagnosis, drug development and the like, will be enabled by elucidating not only arrays of genes but also functions thereof. In a part of medical institutions, individual gene analysis has already been started, which uses a gene analysis technology such as a gene diagnosis system and a DNA chip. Moreover, a wide application of such an analysis technology to novel industries is also expected.
[0005] Work of acquiring useful knowledge for the human being from a large amount of data, for example, elucidation of the gene functions from an integrated database regarding the genes is referred to as data mining. Heretofore, as analysis algorithms for carrying out the data mining, a correlation rule, a decision tree, clustering, a neural network, a genetic algorithm and the like have been researched. Each of these methods has been evaluated somewhat well and recognized as a useful algorithm. However, considering feasibility that data accumulated in a large amount can be actually applied to each analysis algorithm as it is, such application can be said to be almost impossible. The analysis algorithm may not directly access data stored in an RDBMS. Moreover, a necessary data structure may differ depending on each analysis algorithm, and originally, the data may not be as normal as expected. It is said that a cost required for such preprocessing for the data mining occupies 60% of the entire cost for the process.
[0006] Since there has not been a standard speculation yet as to which range in the entire process the preprocessing is referred to, preprocessing in various forms has been researched. In a database, a data query language represented by an SQL is used fully to operate data. Similarly, also in The World Wide Web Consortium (W3C) providing the extensible Markup Language (XML) (refer to http://www.w3.org/XML/), various researches have been made in order to realize data operation using a data query language. The researches described above have an object in providing means for operating data, but not in automating the operation itself. Availability of the XML has been recognized in various fields. For example, also in the field of bioinformatics, the XML has acquired evaluation as below. Specifically, according to the evaluation, though the XML has low expressivity of semantics since it is self-descriptive, ontology will be described by the XML owing to describability inherent in grammar thereof, sureness in a structure, handling easiness, a degree of penetration and the like.
[0007] With regard to a method for navigating a tree structure, there has been a tool proposed by IBM Japan Co., Ltd. and so on (see the gazette of Japanese Patent Laid-Open No. 2000-194466). Regarding an object tree, this tool only displays a path from a moving point to a root of the tree structure and a complete subtree of moving points in movement to a non-leaf node in navigation. Although the method is good as an interface for exploring target information from an object tree that is asymmetric and is formed in a complicated structure, the method cannot dynamically transform a data aggregate or a data structure upon receiving a request from a user.
SUMMARY OF THE INVENTION
[0008] In the event of the preprocessing for the data mining, many applications, data formats and procedures must be managed by the human being, and a process thereof is accompanied with much labor and difficulty.
[0009] The present invention has an object to provide means capable of solving trouble in managing the data formats and the procedures and capable of carrying out advanced preprocessing more intuitively in the preprocessing for the data mining.
[0010] The present invention provides a method capable of handling data aggregates of various types unitarily and capable of dynamically changing the data aggregate and the data structure by reflecting an interaction from a user in the event of the preprocessing for the data mining. Moreover, the present invention provides an interface for the method. Concretely, a data aggregate to be preprocessed is divided into small processing units that are XML data, processing filters for the processing units are generated by a system, and the user selects the processing filters. Thus, the preprocessing that has been hitherto performed manually can be executed with good efficiency. Specifically, the data structure in the large amount of data is created independently of the data, and the data structure thus created is transformed, thus efficiency of the transformation processing is promoted.
[0011] In order to implement these functions, the following processing is executed for the data. The data aggregate is converted into a hierarchical unit tree of the XML format, and the data aggregate is decomposed into processing units. Moreover, the hierarchical unit tree obtained herein is visually displayed.
[0012] Inspection is executed as to whether or not a filter for removing a noise and so on can be applied to the hierarchical unit tree and the data aggregate of the XML format. Then, a conversion request from the user is executed for the hierarchical unit tree displayed on a screen via operation such as dragging of a mouse on the screen.
[0013] The data aggregate converted and created by the user is analyzed by use of a mining engine. Based on a result of the analysis, the data conversion can be executed again.
[0014] The XML handled in the present invention has been proposed by the W3C and is a limited subset of the Standard Generalized Markup Language (SGML) originally prescribed as a standard of an electronic filing document by the ISO. The entire XML documents always fit the SGML standard. The reason why the XML is established is as below. Specifically, though the SGML document having an optional document format has been desired to be widespread as a standard similarly to the Hyper Text Markup Language (HTML) that has already been widespread, the SGML document difficult to be implemented has been hard to be widespread. As a result of extensive researches, the XML has been designed to maintain mutual operationality for both of the SGML and the HTML. In the W3C, as design goals of the XML, the following points are enumerated.
[0015] The XML can be used as it is on the Internet.
[0016] The XML supports applications in a broad range.
[0017] The XML has compatibility with the SGML.
[0018] A program for processing the XML document can be readily written.
[0019] In the XML, functions of options can be minimized as much as possible, and ideally, no function should exist.
[0020] The XML document is easy to be read and fully understood by the human being.
[0021] Design for the XML is carried out fast.
[0022] Design for the XML is to be definite and simple.
[0023] The XML document can be readily created.
[0024] In the XML, it is not important to reduce the number of markups.
[0025] There are no other data formats achieving all of these design goals. For example, as a system for making the XML usable as it is on the Internet, a naming space is prepared, and thus enabling naming of a unique document in the world by use of a URL and definite regulating of a data structure by use of Data Type Definition (DTD). Moreover, a Document Object Model (DOM) and a Simple API for XML (SAX) as Application Program Interfaces (API) for processing the XML document have been introduced by the W3C, and all of the XML processing systems conform to these APIs.
[0026] The XML document has a logical structure and a physical structure. Physically, the document is composed of a unit as an entity. If an entity refers to the other entity, the entity referred to also becomes a part of the document. The document starts from a root, that is, a document entity. Logically, the document includes a declaration, an element, a comment, a letter reference and a processing instruction, all of which are shown by explicit markups in the document. The logical structure and the physical structure must be nested definitely.
[0027] It can be said that the widespread of the XML combining definitiveness and implementation easiness is along a natural flow. XML parsers for structure analysis and style sheets for shaped display are announced one after another by various vendors. Concurring with the above, the XML has come to be used not only on the Internet but also for data exchange in other fields relating to a computer.
[0028] For example, in an article of bioinformartics (Robin McEntire, Peter Karp, Neil Abernethy, et al., “An Evaluation of Ontology Exchange Languages for Bioinformatics”, ISM B2000.), mentioned is that, in information accumulation in the field of bioinformatics, not the conventional list structure for use in LISP but a data structure using the XML will come to be necessary considering input easiness and affinity for various applications for use in information display and information analysis.
[0029] As described above, the XML fits the object of the data formats required in the present invention. A format such as a flat table and a relational database, which has been hitherto used in the preprocessing, is insufficient, and a data structure to be handled is required to be shaped in a tree structure or a graph structure. The XML has a tree structure, and no problem occurs regarding the affinity for the other applications, which is required in the preprocessing performing various types of processing. Furthermore, considering the actual condition where a large amount of information to be accumulated is being changed to the XML, it can be said that the preprocessing using the XML is rather along a natural flow.
[0030] The present invention has an object to realize processing using transformation of the XML for the preprocessing mainly targeted to transformation of the data structure, at which the relational database is not good. In this event, the premise is made that the preprocessing can be carried out by use of a system capable of realizing automatic preprocessing.
[0031] Here, when the preprocessing for the data mining is carried out by use of the variation of the XML, there appears a problem that operation definition is troublesome. This is because the data used for the data mining has a very large number of elements as compared with an XML document typically exchanged by EDI and the like. An interface of the DOM or the SAX, which is prepared by the W3C, only supports movement of one entity at a time. Therefore, some systems referring to many elements are required.
[0032] The reason why the operation can be defined by brief SQL sentences in the relational database is that combination of simple table structures is used and that a large amount of data can be designated at a time on columns and rows. As a typical research for referring to or moving many entities as described above in the XML, there is XML-QL (S. Abiteboul, D. Quass, J. McHugh, J. Windom, and J. Wiener, “The Lorel query language for semistructured data”, International Journal on Digital Libraries, 1(1): 68-88, April 1997.). The XML variation of the present invention can be expressed by use of the XML-QL. However, as problems on the use of the XML-QL, the description is accompanied with some abstrusities, and the variation is carried out in a black box manner. For example, for a request such that movement of only a certain element is cancelled after moving a plurality of elements, a query sentence is required to be rewritten.
[0033] In the present invention, consideration is made for enabling such back track and for a small processing unit obtained by decomposing the entire of the preprocessing in order to automate the preprocessing. This is a similar conception to “action for planning” as classical means of machine learning, which can be said to be a natural way of thinking. Concretely, small variation for the XML is referred to as a filter, and the entire of the XML variation is realized by applying free combination of such filters.
[0034] Here, considering as to what unit the filters are required to be divided into, it may be said that one filter is realized by creating or moving one element of the XML. However, it is self-evident that the number of necessary filters is being increased as the number of elements is increased if the filters are divided in such a manner as described above. Accordingly, in order to make it possible to create the filters efficiently and to provide an easy-to-see view, as shown in FIG. 4, proposed is a structure referred to as a hierarchical unit tree, which is capable of viewing the entire of the XML at a glance and well resembles the conception of the Data Type Definition (DTD). The hierarchical unit tree is a structure decided irreversibly by the XML data and does not include the contents of the data. Filters for the hierarchical unit tree are made to correspond in advance to filters subjected to the XML variation, and the XML data is preprocessed by use of an aggregate of the filters decided on the hierarchical unit tree.
[0035] In order to generate the hierarchical unit tree, an algorithm shown below is used.
Expression 1
[0036] 1 UnitNode makeUnitRoot (Element docRoot)
[0037] 2 begin
[0038] 3 UnitNode unitRoot=new UnitNode ( );
[0039] 4 makeUnit(docRoot, unitRoot);
[0040] 5 return unitRoot;
[0041] 6 end
[0042] 7 void makeUnit(Element docNode, UnitNode unitNode)
[0043] 8 begin
[0044] 9 for each docChild in docNode.childElements
[0045] 10 begin
[0046] 11 if (not unitNode.hasChild(docChild.name))
[0047] 12 begin
[0048] 13 UnitNode newChild=new UnitNode ( );
[0049] 14 newChild.name=docChild.name;
[0050] 15 unitNode.appendChild(newChild);
[0051] 16 end
[0052] 17 unitChild=unitNode.getChild(docChild.name);
[0053] 18 if(flag(docChild.name)==true)
[0054] 19 begin
[0055] 20 unitChild.multiple=true;
[0056] 21 end
[0057] 22 flag(docChild.name)=true;
[0058] 23 makeUnit(docChild, unitChild);
[0059] 24 end
[0060] 25 end
[0061] Among them, the function of makeUnitRoot is a function for creating hierarchical unit tree. In the first to sixth rows, the function of UnitRoot is called by handing the document entity and a newly created node of the hierarchical unit tree to makeUnit as a recursive function. Unit is a function for obtaining a hierarchical unit tree below unitNode based on information of docNode, whereby roots of the hierarchical unit tree structured based on docRoot are stored in unitRoot in the third row. makeUnit is operated as below.
[0062] 1. Children of docNode are sequentially assigned to docChild in the ninth row.
[0063] 2. If there exists no child having the same name as docChild in unitNoe in the eleventh to sixteenth rows, new UnitNode is created, to which the same name as docChild is given, and then set as a child of unitNode.
[0064] 3. UnitNode that is a child of unitNode and has the same name as docChild is assigned to unitChild in the seventeenth row.
[0065] 4. If Element exists below one docNode, the Element having the same name as the docNode, then a multiple field of UnitNode representing the concerned Element is set true in the eighteenth to twenty-second rows.
[0066] 5. The function of makeUnit in the twenty-third row is called recursively.
[0067] The document entity of the XML document is handed to an argument of the function of makeUnitRoot, whereby, seen from the document entity, elements reached through the same path are collected, and root elements of the hierarchical unit tree is obtained, where the multiple field representing whether or not a relationship among the elements is a one-to-multi relationship is appropriately set. Hereinafter, the above-described elements reached through the same path will be referred to as symmetric elements.
[0068] The XML data exemplified in FIG. 3 has a hierarchical structure as shown in a lower part of the drawing. On the other hand, in the case of applying the function of makeUnitRoot, the hierarchical unit tree as shown in FIG. 4 is created. As shown in the hierarchical unit tree, there are elements of “unit” in the one-to-multi relationship under “root”, and one “key”, one “R 1 ” and a plurality of “R 2 ” belong to the elements of “unit”. The hierarchical unit tree is a tree structure reflecting only the data structure of the XML data, and does not include the contents of the data. Moreover, redundant data structures are merged and optimized.
[0069] Next, a schematic configuration of the entire system according to the present invention is shown in FIG. 1. As input formats, conceived is every input format such as a table, a relational database, a text and an XML, which is converted into the XML by a simple program, and then inputted to this system. Actually, this system implements a simple conversion program from the Comma Separated Value (CSV) file to the XML file, which carries out conversion as shown in FIG. 5.
[0070] The XML file inputted is represented as a DOM in the system. The DOM is an object tree defined by the W3C, which is obtained by converting the XML reversibly. The DOM implements an API for changing the tree structure. By use of the API, a hierarchical unit tree corresponding to the inputted XML is generated. While viewing the hierarchical unit tree, a user proceeds to constitute a filter path as a combination of filters by use of an interface prepared on a Web browser. To the hierarchical unit tree without data, which is a compact object tree for the XML as a source of the conversion, the filter path can be applied instantaneously. While viewing a state of the hierarchical unit tree, the user proceeds to select the preprocessing. When the preprocessing proceeds to some extent, the filter path applied to the hierarchical unit tree is also applied to the XML, thus generating an XML for analysis. The filter path mentioned herein is a filter path for the XML, and the filter path for the hierarchical unit tree is defined in advance for each filter. The XML file for analysis can be inputted to an analysis algorithm. A result of the analysis can be browsed on the Web browser or taken out as a file. The filter path is corrected by viewing the result.
[0071] The filter path during operations for the above is automatically saved, and the user can automatically select the filter path by use of weighting derived from resemblance of the hierarchical unit trees. By iterating the above operations, the preprocessing capable of obtaining more interesting results is going to be explored. Application of various filters to the hierarchical unit trees, that is, an operation history for the hierarchical unit trees is saved in a history file, and thus the operation can return to a state of the hierarchical unit tree in a step before the step applied with the filter by some steps according to needs. And, to the hierarchical unit tree in the state to which the operation returns, another filter string can be applied.
[0072] The interface used by the user is roughly classified into the following three categories.
[0073] Browsing and operation of the hierarchical unit tree
[0074] Browsing and operation of the filter path
[0075] Answering a question which the system makes
[0076] The browsing and operation of the hierarchical unit tree and the browsing and operation of the filter path are performed on the same screen. For example, on the screen shown in FIG. 16, the left side thereof shows an interface for the browsing and operation of the filter path, and the right side thereof shows an interface for the browsing and operation of the hierarchical unit tree.
[0077] The browsing and operation of the hierarchical unit tree is carried out on an Applet shown in FIG. 16. Differences between a leaf node and a non-leaf node and between the numbers of times these nodes appear in the XML document are designed to be grasped at a glance by colors and shapes. Each circle and square represents a relationship between elements. The circle represents that a relationship between an element and a child element is one to one, and the square represents that the relationship between the element and the child element is one to multi. The number in each element represents the number of times the element appears during conversion from the XML to the hierarchical unit tree. A name of the element is displayed near the circle or the square, which represents the element. Application of the filter is basically executed by selecting one or a plurality of nodes and pressing a button for applying the filter. Application of a moving filter to be described later can be also made by drag&amp;drop from node to node.
[0078] The browsing and operation of the filter path is carried out on the HTML on the left-side frame displayed on the Web browser shown in FIG. 16. On the screen, the filter path already applied is displayed as a history 1605 . In a filter name portion of the filter path already applied, a hyperlink is set. By clicking the hyperlink, returning can be made to a site which the hyperlink designates. In the case of creating a new filter, when a Create New Filter hyperlink 1609 is clicked, a subwindow 1611 opens, and a candidate of the filter is displayed. Also in a filter name portion displayed on the subwindow 1611 , a hyperlink is set, and when the hyperlink is clicked, another interface is displayed, where a detail of the filter is set. The filter thus created is added to an end of the filter path. The display of the hierarchical unit tree is always carried out by clicking a View Unit hyperlink. The display reflects a current state of the filter path.
[0079] An example of an answer to a question made by the system is shown in FIG. 20. A Mining link 2001 in an upper-part drawing is clicked, whereby an interface for applying a mining engine shown in a lower-part drawing appears. Here, a part 2010 of a file inputted to the mining engine is seen. An option letter string for the analysis algorithm by a decision tree or a correlation rule can be given by seeing the part of the file and can be executed.
[0080] In summarizing the above, a method of preprocessing for data mining according to the present invention comprises the steps of: creating, from XML data, a hierarchical unit tree as a tree structure in which attributes of the XML data are set as a leaf node and a non-leaf node, a relationship between the attributes without including an attribute value is expressed, and a redundant parent-child relationship between the nodes is optimized by merging; adding a change to the hierarchical unit tree; and converting the XML data so as to reflect the change added to the hierarchical unit tree.
[0081] The method of preprocessing for data mining according to the present invention comprises the steps of: displaying, on a screen, a hierarchical unit tree as a tree structure in which a leaf node and a non-leaf node, and a branch expressing a parent-child relationship between the nodes are included, both of the nodes corresponding to attributes of XML data, and a redundant parent-child relationship between the nodes is optimized by merging, the hierarchical unit tree being created from the XML data; adding a change to the hierarchical unit tree; and converting the XML data so as to reflect the change added to the hierarchical unit tree.
[0082] The operation for adding a change to the hierarchical unit tree includes: an operation (Group filter) for setting a plurality of nodes as child nodes of a node newly created on the same hierarchy as the plurality of nodes having the same non-leaf node as a parent; an operation (Move filter) for moving a designated node to a position of a child of the other node than a current parent of the designated node; and an operation (Rename filter) for changing attribute names of a plurality of nodes to the same attribute name, the plurality of nodes having the same non-leaf node as a parent, and for merging the plurality of nodes. The operation for moving a designated node to a position of a child of the other node than a current parent of the relevant designated node can be executed by dragging the designated node by mouse and dropping the designated node on a node newly to be a parent.
[0083] Moreover, it is preferable that a constitution be adopted, in which an operation history for hierarchical unit trees is displayed, the hierarchical unit trees changed by operations are recorded respectively, and when a specified operation step of the operation history displayed is designated, a hierarchical unit tree corresponding to the operation step is displayed.
[0084] A preprocessing system for data mining according to the present invention comprises: a display unit for displaying a hierarchical unit tree as a tree structure in which a leaf node and a non-leaf node, and a branch expressing a parent-child relationship between the nodes are included, both of the nodes corresponding to attributes of XML data, and a redundant parent-child relationship between the nodes is optimized by merging, the hierarchical unit tree being created from the XML data; and a filter selection unit for selecting a filter for adding a change to the hierarchical unit tree. It is more preferable that the system further comprises: a history display unit for displaying a history of filters applied to the hierarchical unit tree.
BRIEF DESCRIPTION OF THE DRAWINGS
[0085] [0085]FIG. 1 is a view showing a flow of processing in one embodiment of the present invention.
[0086] [0086]FIG. 2 is a view showing a flow of a display screen in one embodiment of the present invention.
[0087] [0087]FIG. 3 is a view showing an example of XML data.
[0088] [0088]FIG. 4 is a view showing an example of a hierarchical unit tree created from the XML data.
[0089] [0089]FIG. 5 is a view showing conversion from an XML to a CSV.
[0090] [0090]FIG. 6 is an explanatory view for an application example of a Group filter to the hierarchical unit tree.
[0091] [0091]FIG. 7 is a view showing an example of an XML after the application of the Group filter.
[0092] [0092]FIG. 8 is an explanatory view for an application example of a Move filter to the hierarchical unit tree.
[0093] [0093]FIG. 9 is a view showing an example of an XML after the application of the Move filter.
[0094] [0094]FIG. 10 is an explanatory view for an application example of a Rename filter to the hierarchical unit tree.
[0095] [0095]FIG. 11 is a view showing an example of an XML after the application of the Rename filter.
[0096] [0096]FIG. 12 is an explanatory view for an application example of a Delete filter to the hierarchical unit tree.
[0097] [0097]FIG. 13 is a view showing an example of an XML after the application of the Delete filter.
[0098] [0098]FIG. 14 is an explanatory view for an application example of a Join filter to the hierarchical unit tree.
[0099] [0099]FIG. 15 is a view showing an example of an XML after the application of the Join filter.
[0100] [0100]FIG. 16 is a view showing a screen example in an initial state of a system according to the present invention.
[0101] [0101]FIG. 17 is a view showing an example of a creation screen of a query.
[0102] [0102]FIG. 18 is a view showing an example of a display of a preprocessing result.
[0103] [0103]FIG. 19 is a view showing an example of the Join filter.
[0104] [0104]FIG. 20 is a view showing an example where correlation between self-evident attributes was discovered in an attribute selection algorithm.
[0105] [0105]FIG. 21 is a view showing an example where a decision tree was obtained by removing the correlation between the self-evident attributes in the attribute selection algorithm.
[0106] [0106]FIG. 22 is a view schematically showing a flow of weight sequencing.
[0107] [0107]FIG. 23 is a flowchart showing a processing procedure of the system of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0108] Hereinafter, description will be made for an embodiment of the present invention with reference to the drawings.
[0109] A display of a hierarchical unit tree, which is proposed by the present invention, is the one that, seen from a root of a tree structure, regards nodes having the same path concerning a node attribute as the same nodes. In the present invention, a coherent operation for the nodes of the hierarchical unit tree can be readily carried out on one view. The hierarchical unit tree is obtained by irreversibly converting an XML. The hierarchical unit tree does not include data but reflects only a data structure. If there exist a large amount of nodes having the same path, the hierarchical unit tree can be expressed by a very small object as compared with the original XML. Therefore, also with regard to an XML including a large amount of data, a data aggregate or a data structure can be changed and edited interactively upon receiving an operation from a user, and thus preprocessing for mining can be carried out efficiently.
[0110] First, an outline of a system will be described with reference to FIG. 1. A user 102 activates a system 102 and registers XML data 104 obtained by converting input data 103 with the system 101 . The XML data 104 is automatically converted into a hierarchical unit tree 105 by a function of makeUnitRoot in the system. The hierarchical unit tree 105 is expressed as a DOM tree 112 inside the system. The user 102 performs an operation 114 for generating filters 106 while confirming the hierarchical unit tree 105 by an interactive operation 113 through an interface 107 , thus obtaining a filter path 115 . In the case of the operation 114 for generating the filters, a hierarchical unit tree 108 (DOM tree 112 ) transformed by the filter path 115 is subjected to feedback to the user 102 by the interface 107 . The user 102 applies XML data 109 obtained by transforming the XML data 104 by the filter path 115 to an analysis algorithm 110 through the interface 107 , and thus the user 102 can obtain an analysis result 111 . Through a result display screen 116 , the analysis result 111 is subjected to the feedback 117 to the user 102 , and thus the user 102 can construct a more sophisticated filter path 115 . Moreover, with regard to such a series of operations, the user 102 can obtain a filter path 115 automatically constructed from a history of the operation 114 . By iterating the above operations, preprocessing with good efficiency is carried out. The history of the operation for generating the filters is stored in a history file 120 together with the hierarchical unit tree made at each operation. Therefore, the user 102 can anytime return to a moment on the way of the filter path 115 , and can resume the operation for the hierarchical unit tree from the moment.
[0111] [0111]FIG. 2 is a schematic view showing a change of a display screen of the system. By inputting the XML data, a hierarchical unit tree 201 is generated and displayed. Filters are generated and selected through an operation frame 202 or the hierarchical unit tree 201 , leading to creation of a filter path. The user can display the hierarchical unit tree 201 on an optional spot of the filter path. The user obtains XML data subjected to transformation added to the hierarchical unit tree, that is, preprocessing corresponding to the created filter path. Then, the user inputs the XML data subjected to the preprocessing to the analysis algorithm, and thus can obtain an analysis result 203 .
[0112] Seeing the result 203 , the user is going to sophisticate the operation for the interfaces of the operation frame 202 and the hierarchical unit tree 201 by the feedback 204 , thus performing the preprocessing with good efficiency. To change a structure of data given to the analysis algorithm is, specifically, to change an attribute or an amount of the data, a relationship among elements inside the data and so on, which directly affects the analysis result to a great extent. In the example of FIG. 2, since different filter paths are selected for the same data in the right course and the left course, it is understood that data inputted to the respective hierarchical unit trees and mining algorithms differ from each other, and that mining results 203 also differ from each other.
[0113] Here, description will be made for types of principal filters applied to the hierarchical unit tree, a transformation state of the hierarchical unit tree by application of the filters, and conversion of the XML data when the filter path is applied to the XML data.
[0114] [0114]FIGS. 6 and 7 are explanatory views for an application example of a Group filter. The Group filter is a filter for grouping a plurality of elements having the same element as a parent in the hierarchical unit tree as child elements of an element to be newly created in the hierarchy. In the event of creating the Group filter, relevant elements (elements to be grouped) in the hierarchical unit tree are selected by mouse, and the Group filter is activated. Then, since input of a group name is requested, the group name is inputted, and a desired Group filter is created. FIG. 6 shows a creation example of the Group filter for grouping an element R 1 and an element R 2 of the hierarchical unit tree shown in FIG. 4 under a newly created element named G 1 as a group name. Application of this Group filter transforms the hierarchical unit tree as shown in a lower part of FIG. 6. In the case of this example, an XML after the application of the Group filter becomes as shown in FIG. 7 corresponding to the transformation of the hierarchical unit tree.
[0115] [0115]FIGS. 8 and 9 are explanatory views for an application example of a Move filter. The Move filter is a filter for moving an element designated in the hierarchical unit tree to a position of a child taking the other element than a current parent as a parent. When the element to which the Move filter is applied has child elements, these child elements also move together with the designated element while maintaining a parent-child relationship therebetween. In the event of creating the Move filter, a relevant element in the hierarchical unit tree is dragged by mouse and dropped on an element to be a new parent. By this operation, a Move filter taking the element dragged by mouse as a child element of the new element is created. FIG. 8 shows a creation example of the Move filter for moving the element R 2 of the hierarchical unit tree shown in FIG. 4 immediately under the Root. By the application of the Move filter, the hierarchical unit tree is transformed as shown in a lower part of FIG. 8. In the case of this example, an XML after the application of the Move filter becomes as shown in FIG. 9 corresponding to the change of the hierarchical unit tree.
[0116] [0116]FIGS. 10 and 11 are explanatory views for an application example of a Rename filter. The Rename filter is a filter for changing an element name of a designated element. Typically, the Rename filter is used for the case of designating a plurality of elements having different element names, and changing the element names to the same name, thus achieving integration of the data. In the event of creating the Rename filter, a relevant element in the hierarchical unit tree is selected by mouse, and the Rename filter is activated. Then, since input of a new element name is requested, the new element name is inputted. Accordingly, a desired Rename filter is created. FIG. 10 shows a creation example of the Rename filter for changing element names of the element R 1 and the element R 2 of the hierarchical unit tree shown in FIG. 4 to an element name R. By the application of the Rename filter, the hierarchical unit tree is transformed as shown in a lower part of FIG. 10. In the case of this example, an XML after the application of the Rename filter becomes as shown in FIG. 11 corresponding to the transformation of the hierarchical unit tree.
[0117] [0117]FIGS. 12 and 13 are explanatory views for an application example of a Delete filter. The Delete filter is a filter for deleting a designated element. When the designated element has child elements, the child elements and elements thereunder are entirely deleted. In the event of creating the Delete filter, a relevant element in the hierarchical unit tree is designated by mouse, and the Delete filter is activated. By this operation, the elements connected to the element designated by mouse are entirely deleted. FIG. 12 shows a creation example of the Delete filter for deleting the element R 2 of the hierarchical unit tree shown in FIG. 4. By the application of the Delete filter, the hierarchical unit tree is transformed as shown in a lower part of FIG. 12. In the case of this example, an XML after the application of the Delete filter becomes as shown in FIG. 13 corresponding to the change of the hierarchical unit tree.
[0118] [0118]FIGS. 14 and 15 are explanatory views for an application example of a Join filter. The Join filter is a filter for joining a designated element to an element existing in the other XML file. In the event of creating the Join filter, a source element, a target XML file and a target element are designated by mouse and the like, and the Join filter is activated. By this operation, an element in a brother relationship with the target element, that is, an element having the same parent element is newly created as a brother element of the source. In this case, on the XML file, data included in the source element and data included in the target element are collated, and elements having equivalent data are joined. FIG. 14 shows a creation example of the Join filter for joining the element R 1 of the source hierarchical unit tree shown in FIG. 4 and an element S 3 of the target hierarchical unit tree generated from the other XML file. By the application of this Join filter, elements S 1 and S 2 as brother elements of the element S 3 are added to the source hierarchical unit tree as shown in a lower part of FIG. 14. In the case of this example, an XML after the application of the Join filter becomes as shown in FIG. 15 corresponding to the change of the hierarchical unit tree and the data of the elements R 1 and S 3 .
[0119] Here, description will be made for conversion of the XML data by the filter path used for the transformation of the hierarchical unit tree. As shown in FIG. 1, the filter path is the one in which a plurality of filters are sequentially arrayed. Moreover, with regard to the entire filters, prepared are the one for transforming the hierarchical unit tree and the one for transforming the XML data. Specifically, the filter path created for transforming the hierarchical unit tree becomes the filter path for transforming the XML data by replacing the filters constituting the filter path to the ones for the XML data. Here, in order to execute the above operation, a condition is set as below. Specifically, the hierarchical unit tree generated from the XML data 109 transformed from the XML data 104 by the lower filter path 115 for the XML data must be equal to the hierarchical unit tree 108 transformed from the hierarchical unit tree 105 by the upper filter path 115 for the hierarchical unit tree having the same filter constitution as the lower filter path 115 .
[0120] Hereinbelow, description will be made for an example of problem solution using subsets of clinical data. Object data has results of fungi inspections for MIC and results of catheter treatments. First, with regard to the fungi inspections for MIC, though, in general, no trouble particularly occurs in processing such small data aggregates as they are, since care must be taken for handling the data aggregates when other results of fungi inspections mixedly exist, processing for collecting the data aggregates into one is carried out. Moreover, with regard to the catheter treatments, attributes having the same meaning are split into “Catheter 1 ”, “Catheter 2 ” and “Catheter 3 ” for the convenience of data input, and these attributes are desired to be collected into one catheter. Specifically, grouping is carried out with regard to the fungi inspections for MIC, and name changing is carried out with regard to the catheter treatments.
[0121] An example to which the Rename filter (name changing) and the Group filter (grouping) are applied will be described with reference to FIGS. 16 to 18 . The Rename filter is a filter for collecting attributes into one when the element names are changed and attributes having the same name consequently exist including a route seen from the document entity. The Group filter is a filter for moving an object element to a child of one new element.
[0122] [0122]FIG. 16 is a view showing an example of an initial state of the hierarchical unit tree. A hyperlink 1602 from an operation frame 1601 to a view is clicked, whereby a view 1603 of the hierarchical unit tree displaying a state of the unit in a tree structure is displayed on the right side of the screen. The view 1603 can be adjusted so as to be easily seen by a scroll bar 1604 or by a zooming operation with a mouse. Moreover, the filter applied to each element can be grasped by a filter path 1605 . In the initial state, a hierarchical structure is not adopted in many cases as on the view 1603 . For example, in this initial state, the attributes representing the same catheter 1606 are described parallel in different names of “Catheter 1 ”, “Catheter 2 ” and “Catheter 3 ”. A table 1610 is for notating source data on CSV, and when output to the analysis algorithm regarding sample ID rows and catheter columns is created in the above state, since no filter is applied thereto, the table 1610 is obtained. In order to create the output to the analysis algorithm, first, the filter path is applied to the XML as the source data inside the system, and further, a conversion program from the XML to the CSV, which performs conversion reverse to the conversion shown in FIG. 5, is applied thereto. In this case, in the catheter 1606 , when the three names of “Catheter 1 ”, “Catheter 2 ” and “Catheter 3 ” are in different columns, these three are not regarded to be in the same attribute depending on the analysis algorithm, which is inappropriate. Moreover, though not being outputted to the table 1610 , abpc 1607 and ampc 1608 as items of the fungi inspection for MIC are desired to be handled as one group. It is assumed that the user grasps all the above.
[0123] In this state, a filter for performing the preprocessing for the data has not been prepared yet. Accordingly, in order to create a new filter, the hyperlink 1609 for creating a filter in FIG. 16 is clicked. Then, a subwindow 1611 for filter selection opens, and candidates for the filter are displayed on the screen. The Rename filter is selected therefrom.
[0124] When the Rename filter is selected, a screen as shown in FIG. 17 is displayed. FIG. 17 is a screen for collecting information required for creating the Rename filter. On the right side of the screen, a question sentence 1702 and an answer box 1703 , which are required for applying the Rename filter, are displayed. A plurality of attributes for which the name changing is desired to be performed are selected from the answer box 1703 , and the name already changed is inputted to a text box 1704 , then an input transmitting button 1705 is pressed. Accordingly, the name is posted to the system. In the case where the Catheter 1 , the Catheter 2 and the Catheter 3 are selected by mouse on the view 1603 of FIG. 16, and thereafter, the Rename filter is selected on the subwindow 1611 displayed by clicking the hyperlink 1609 for filter creation, then the Catheter 1 , the Catheter 2 and the Catheter 3 are selected in the answer box 1703 on the screen of FIG. 17.
[0125] The operation similar to the above is carried out also for the element abpc 1607 and the element ampc 1608 with regard to the Group filter, “MIC” is inputted as a group name of the element abpc 1607 and the element ampc 1608 , and the hyperlink 1706 to the view is clicked. Then, a view as shown in FIG. 18, which reflects the Rename filter and the Group filter, can be obtained. A filter path 1805 shows the filters already applied. A catheter 1801 is recognized as an attribute having a one-to-multi relationship to one parent attribute. As a result of applying the Group filter to MIC 1802 , the MIC 1802 adopts a hierarchical structure. When output from this view with regard to the sample ID rows and the catheter rows is carried out, a table 1804 is obtained, where the one-to-multi relationship between a sample 1803 and the catheter 1801 is correctly expressed.
[0126] An example of applying the Join filter will be described with reference to FIG. 19. Here, consideration is made for classifying attributes of elements 1902 with resistance-definition-classification attributes 1906 referred to as bacteria.xml in the other XML file, the elements 1902 having an attribute name of “detected fungi” in a hierarchical unit tree 1901 . Here, the Join filter has already been defined, and elements 1906 having an attribute name of resistance-definition classification in bacteria.xml and elements 1905 having an attribute name of detected fungi in bacteria.xml have already been joined to each other. For the joining, mouse dragging is used. The joining is established by dragging the elements 1905 of the detected fungi attribute in a hierarchical unit tree 1904 representing bacteria.xml to the elements 1902 of the detected fungi attribute in the hierarchical unit tree 1901 . If this dragging is carried out when not the Join filter but the Move filter is selected, it means that the elements 1905 of the detected fungi attribute is moved to a child of the resistance-definition-classification attributes 1906 . By this joining, the resistance-definition-classification attributes 1906 located in the same hierarchy as the elements 1905 of the detected fungi attribute in bacteria.xml are created in the same hierarchy as the elements 1902 of the detected fungi attribute. In the actual XML data, elements having the same data in the elements 1902 of the detected fungi attribute and the elements 1905 of the detected fungi attribute are joined to each other. The Join filter is applied by clicking a filter name portion 1909 thereof. It is understood that resistance-definition-classification attributes 1908 are added to the hierarchical unit tree to which the Join filter has already been applied, and that the Join filter 1910 is added to the filter path.
[0127] An example of feedback from a mining algorithm will be described with reference to FIGS. 20 and 21. First, the preprocessing has already been performed to some extent in FIG. 20, where the input file to be inputted to the mining engine, which is a program for generating a decision tree of the mining engine, is created in order to obtain a decision tree with regard to the resistance definition classification. In the mining engine, attribute selection can be carried out by use of a built-in algorithm such as a highest priority selection method. Here, it is understood that an attribute 2004 in which correlation with the resistance definition classification is self-evidently high before making the decision tree is extracted as an attribute having high correlation therewith actually. When such an attribute is included, the decision tree is statistically dominated thereby, and only a self-evident decision tree can be obtained. Therefore, such an attribute must be removed.
[0128] A reference numeral 2102 in FIG. 21 denotes a mining result, which is obtained by performing the feedback in the above-described manner and is constituted of the attribute in which the correlation with the resistance definition classification is not self-evidently high but actually high. A hierarchical unit tree 2101 in this case has the same structure as a hierarchical unit tree 2002 in FIG. 20. However, a different mining algorithm is applied thereto, and thus a different result is obtained. It can be expected that an interesting decision tree is obtained from such a mining result, and the decision tree actually obtained is the one as denoted by a reference numeral 2103 .
[0129] All the above is a part where the process of the preprocessing is unitarily carried out. FIG. 22 is a view schematically showing sequencing for use in the case where the system creates a large number of application columns of filters by reusing the filters created once. This drawing shows a flow of classical weighting. Each of users 2201 creates a filter that does not exist in a filter group 2202 and makes an addition 2205 thereof to the filter group 2202 . The filters of the addition 2205 thereto are commonly shared by a plurality of the users 2201 and weighted for each of the users. While the weighting of the filters is varied depending also on a state of the unit, the filters are held by a common filter path map 2203 . Evaluation for the common sharing is varied depending on evaluations 2206 from the users 2201 . Such evaluation reacts promptly to the evaluations 2206 to filter path maps 2204 for each session, but does not react so promptly to evaluations 2207 to the common filter path map 2203 . Deletion 2208 from the filter group 2202 is performed by the common filter path map 2203 for filters having weight lower than a certain threshold value. By use of the filters weighted as described above, selection of the filter paths is automatically carried out based on the resemblance of the hierarchical unit trees.
[0130] [0130]FIG. 23 is a flowchart of the system created in the present invention. After activating the system (step 2301 ), the user selects an XML file (step 2302 ). Since the filter path is initially null, a filter is selected. In the case where the filter is automatically selected, the process proceeds from step 2304 to step 2308 , where a plurality of filters are automatically selected. With regard to the case of selection by the user himself/herself, when a desired filter is judged to be already created in step 2305 , the filter is selected from the already created filter group (step 2306 ); otherwise, a filter is newly created on the Web browser (step 2307 ) and added to the filter path. Selection is performed in such a manner, and if a filter path as desired is judged to be finally obtained in step 2303 , the filter path is applied to the XML file, and an analysis result is displayed (step 2309 ). If the analysis result is not a desired one, the process returns to the selection of the filter. If the analysis result is judged to be a desired one in step 2310 , the analysis result and the data already subjected to the preprocessing are stored (step 2311 ), then the process is terminated.
[0131] Heretofore, various types of data such as expression and clinical data have been individually processed manually by experts, and thus noise removing therefrom, input thereof to the mining and the like have been carried out. In the present invention, the data conversion and input can be dynamically carried out by changing the node conditions of the hierarchical unit tree, thus making it possible to perform the mining efficiently with high precision.
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Disclosed is means capable of solving trouble in managing data formats and procedures and capable of carrying out advanced preprocessing more intuitively. A data aggregate to be inputted to a mining engine is converted into hierarchical unit trees, and node conditions of the hierarchical unit trees are changed, whereby the data aggregate and a data structure are subjected to dynamic conversion/edition processing. Thus, a system is constructed, in which preprocessing for data mining is unitarily managed/semi-automated.
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FIELD OF INVENTION
The present invention relates to a method and a system for providing a virtual job market on a computer network, preferably on the internet. For providing such a virtual job market, a three dimensional database model is generated.
BACKGROUND OF INVENTION
Commonly, the job market is represented by classified adds—in print or on the internet—onto which a job seeker is reacting or alternatively by Human Recourses recruiters which are placing candidates in certain positions. Recently, virtual job market places were introduced.
U.S. Pat. No. 6,873,964 B1 describes a method for recruiting personnel for a business entity including a plurality of distinct business units each having individual hiring requirements, wherein at least some of the distinct business units' hiring requirements compete for common applicants, the method including the steps of: entering information related to a plurality of hiring needs, each of the plurality of hiring needs being respectively associated with one of the plurality of distinct business units, and information related to a plurality of candidates into a database, respectively; automatically cross-referencing the information related to the plurality of hiring needs with the information related to the plurality of candidates to identify candidates selected the plurality of candidates who satisfy entered information indicative of hiring needs; and, determining which of the identified candidates should be offered a job associated with the hiring needs; wherein, when it is determined that one of the identified candidates should be offered more than one job as determined by the hiring needs, all jobs pertinent to the one of the associated candidates are offered substantially simultaneously to the one of the identified candidates.
U.S. Pat. No. 6,662,194 B1 describes an apparatus and method for providing recruitment information, including a memory device for storing information regarding at least one of a job opening, a position, an assignment, a contract, and a project, and information regarding a job search request, a processing device for processing information regarding the job search request upon a detection of an occurrence of a searching event, wherein the processing device utilizes information regarding the at least one of a job opening, a position, an assignment, a contract, and a project, stored in the memory device, and further wherein the processing device generates a message containing information regarding at least one of a job opening, a position, an assignment, a contract, and a project, wherein the message is responsive to the job search request, and a transmitter for transmitting the message to a communication device associated with an individual in real-time.
WO 01/82181 A2 describes a method and system generating referrals for job positions based upon virtual communities comprised of members relevant to the job positions. This disclosure includes three primary methodical tools. The first tool implements a job recruiting toolkit. The second tool implements a method of generating referrals based upon a virtual community of people who relate to the job description. The third tool implements an enterprise recruitment toolkit.
A major drawback of the existing systems is the lack of additional information regarding industries, career levels and functional areas. Also, in general no salary ranges, etc. are provided for certain jobs.
It is one object of the present invention to overcome the drawbacks of the prior art and to provide a virtual job market place superior to existing methods and technologies.
The method according to claim 1 and the system according to claim 6 of the present invention solve this object and provide a virtual job market place superior to existing methods and technologies. It addresses inefficiencies in the labour market created by inappropriate definition of the labour market and incomplete construction of existing systems.
The present invention involves the following features:
1. Creation of a complete marketplace: combination of labour demand, labour supply and a pricing mechanism (salary information on every job seeker and every job), establishing basic elements of a market place within one closed data system. Note: existing technologies on job markets exclude salary, which in turn creates a demand/supply match without pricing information. A market place without a pricing mechanism cannot create clearance with a period and suffers from imperfect information. 2. Unique structure of the labour market: Combining generally known concepts to a unique combination of dimensions creates a far more complex marketplace, yet easy to understand and more relevant for all participants.
SUMMARY OF THE INVENTION
A comprehensive, distinct, and scalable aggregation of industries and sub-segments as provided by the invention creates a complete virtual job market place of an entire economy. It analyzes and allocates demand and supply of human resource into distinct “commodity markets” and/or segments of the labour market. The secondary dimensions qualify each individual job or profile within this marketplace with the relevant information. In this context the primary dimensions create efficient job marketplaces. The secondary dimensions match demand and supply along the qualitative features and provide the information for more efficient market clearance. This combination is unique, significantly more complex and processes richer data than existing technologies. Yet, due to the “standard nature” of each dimension it is intuitively to understand.
BRIEF DESCRIPTION OF FIGURES
FIG. 1 shows a simplified sketch of a preferred embodiment of the present invention;
FIG. 2 shows a simplified sketch of a job marketplace with unique taxonomy;
FIG. 3 shows a simplified sketch of machine-to-machine interfaces;
FIG. 4 shows a simplified sketch of one example of the architecture that may be used for the application;
FIG. 5 shows a simplified sketch of a matching process used in another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention integrates the three defining factors of a market: (A) demand (for labour), (B) supply (of labour) and (C) a pricing mechanism which is provided by the invention. The pricing element, in particular, has traditionally been left out of data-driven labour market applications. The invention creates systems having (i) various functions, (ii) efficient market, and integrates them with (iii) increased transparency and (iv) reduced information pathology
FIG. 1 shows a preferred embodiment of the present invention, which will be described as follows.
(A) Demand (Examples):
(1)/(2) HR Departments, independent recruiters and head-hunters can post job openings according to the marketplace taxonomy (see 2.)
(3) Direct job aggregation from company websites through xml-interface, manual and/or crawler supported input of job data provided on company career websites
(4) Head-hunters searching for relevant individuals. Search covers existing job position, career history and career goals
(B) Supply (Examples)
(5) Individuals can search job database
(6) Individuals define next career steps and receive matching openings
(7) Individuals can define career profile/CV and set confidentiality levels to be found by head-hunters
(C) Pricing—Salary Information (Examples)
(8)/(10) A firm or a head-hunter leave salary range by posting an opening
(9) A firm provides an entire salary matrix for all internal levels and all functions (i.e. sales, finance etc.)
(10) An individual provides his/her existing salary range and current position
(11) An individual provides his/her desired salary range and desired position
The invention organizes data on the job market along the following primary and secondary dimensions:
Primary Dimensions:
(1) industries
(2) career levels
(3) functional areas
Secondary Dimensions:
(4) salary ranges
(5) geo-data (country, city, ZIP code, IP address, GPS data, GSM information)
(6) educational information
(7) languages
(8) special expertises
Furthermore, as shown in FIG. 2 , the invention collects the following information chunks (jobs/candidate profiles) and places them in a distinct cell or number of cells.
Information Chunks (Jobs/Candidate Profiles)
(D) open jobs, which are determined by one distinct cell
(E) candidate profiles, which are a sequence of cells determined by a candidates past jobs, current job and desired future job
In the system according to the present invention, the primary dimensions determine the structure of the data repository and place the information chunks (jobs and candidate profiles) in the proper position in the virtual job market established in the database. The secondary dimensions determine the quality of the information chunks. They enable a ranking of competing information chunks in the same job market segment. For example multiple jobs or multiple candidate profiles are placed in the same sub-segment of the virtual job market place, i.e. level—(e.g., “senior professional”), function (e.g., “sales”), and industry (e.g, ‘book publishing”). The secondary dimensions (e.g, salary range, special expertise etc.) qualify them in a fashion that generates a clear-cut matching between demand and supply.
The primary dimensions determine the relevant marketplace within the system and distinctly position the job and candidate profile at the appropriate place in the system so that demand and supply can meet. By doing so the model generates a human resource commodity and allocates it to relevant “commodities markets” and/or job market segments. By placing pricing information to the commodity it enables a complete marketplace.
Each of the primary dimensions are intuitive to understand and relate to common understanding and concept adopted by economic theory as well as practice. The innovative aspects of the invention involve the combination of the three dimensions to deliver a contingent system to cover the job market.
(1) Industries and Sub-Segments
The first innovation is to analyse the job market in a very granular fashion according to industries and sub-segments of industries. This is crucial as job market competition by and large takes place as a function of the competition of firms in the markets for products and services. Special skills, know how, contacts and other resources acquired in a very specific industry segment strongly determine the returns a candidate can yield on the job market. This analysis will be conducted automatically as long as the required information is pre-processed according to the systems input rules.
Industries are segmented in multiple levels: 4 levels and maximum 10 entries per level, e.g.: 0000 Main Industry 1 (i.e. services)
0100 Segment 1 Level 2 (i.e. media)
0110 Segment 1 Level 3 (i.e. print publishing)
0111 Segment 1 Level 4 (i.e. book publishing) 0112 Segment 2 Level 4 (i.e. trade magazine publishing) 0113 Segment 3 Level 4 (i.e. newspaper publishing) 0114 Segment 4 Level 4 (i.e. special interest magazine publishing) 0115 Segment 5 Level 4 (i.e. general interest magazine publishing) And so forth
0120 Segment 2 Level 3 (i.e. Music) 0130 Segment 3 Level 3 (i.e. TV) and so forth
0200 Segment 2 Level 1 (i.e. Consulting) 0300 Segment 3 Level 1 (i.e. Financial Services) and so forth
1000 Main Industry 2 2000 Main Industry 3 and so forth
(2) Career Levels
Career Levels give an abstract representation of hierarchy, which exists in every company. To apply this invention the career levels should be customized depending on the target market. i.e. in the current application the following levels are distinguished for a market of very qualified white collar professionals and executives:
executive management midsized and large companies executive management small companies business unit mgmt senior management management senior professional professional junior professional/entry level
(3) Functional Areas
Functional areas determine in which value-creating part of firm—or “where in the value chain”—a job is positioned. The concept of the value chain is generally accepted to describe all sorts of businesses and its internal functional organization, i.e. sales, research, development, production etc. Today the taxonomy of the value chain is understood common sensually in developed economies.
For each industry the combination of 2-career levels and 3-functions establishes a matrix. Within this matrix various salary data can be calculated, such as salary ranges or average mid-points. In the following example, table 1, average mid-points are calculated.
TABLE 1
Industry: Segment 0000
Career Level
Executive Board
Entry
Senior
Senior
Business Unit
medium/large
Executive Board
Level
Professional
Professional
Manager
Manager
Manager
company)
(small company)
Function
1
2
3
4
5
6
7
8
Management
1
150
150
200
Planing, Controlling
3
40
50
65
90
120
140
PR
12
35
47
60
80
100
120
Finance, Accounting
4
40
55
70
90
120
140
Legal
5
40
55
70
90
120
140
HR
6
35
45
60
80
100
120
Administration
7
35
45
60
80
100
120
IT, Telecom
13
45
55
70
90
120
140
Purchasing, Logistics
8
40
55
70
90
120
140
Customer Support
15
35
40
55
65
85
100
Production
9
45
60
70
90
110
130
Consulting
16
45
60
70
90
120
140
Design
17
45
55
65
80
110
130
Documentation
18
45
55
65
90
110
130
R&D
14
45
60
75
90
120
140
Sales
10
40
60
75
90
150
180
Marketing
11
45
55
70
90
120
140
Strategy, M&A
2
55
70
90
120
150
200
The following secondary dimensions provide for job market-specific qualification of information chunks (e.g., open jobs, candidate profiles). By adding these informational dimensions, the human resource commodity allocated to a sub-segment of the labour market gets “de-commoditized” for the specific sub-segment of the labour market by adding qualitative information. This is important to assess the yield (salary potential) a specific job or candidate has in the relevant target market.
(4) Salary Ranges
Salary ranges, representative for a market can be set up, whereas overlapping ranges created a perception, which prevents users from overstating their current salary as shown in Table 2.
TABLE 2 id no label min_salary max_salary - current salary - 13 2 50.000-60.000 EUR 50000 60000 1 3 55.000-65.000 EUR 55000 65000 2 4 60.000-70.000 EUR 60000 70000 3 5 65.000-75.000 EUR 65000 75000 4 6 70.000-80.000 EUR 70000 80000 5 7 75.000-85.000 EUR 75000 85000 6 8 80.000-90.000 EUR 80000 90000 7 9 85.000-105.000 EUR 85000 105000 8 10 90.000-110.000 EUR 90000 110000 9 11 100.000-130.000 EUR 100000 130000 10 12 120.000-150.000 EUR 120000 150000 11 13 >150.000 EUR 150000 200000 12 14 >200.000 EUR 200000 -desired salary/job posting salaries 8 1 >60.000 EUR 60000 70000 1 2 >70.000 EUR 70000 80000 2 3 >80.000 EUR 80000 90000 3 4 >90.000 EUR 90000 100000 4 5 >100.000 EUR 100000 120000 5 6 >120.000 EUR 120000 150000 6 7 >150.000 EUR 150000 200000 7 8 >200.000 EUR 200000
(5) Geodata (Country, City, ZIP Code)
Each open job or current/past job in a candidate profile needs to be defined geographically, where the global ZIP code systems provides a sufficiently rich system
(6) Educational Information
Educational information is defined along two data dimension: (i) study major, (ii) highest degree per major.
(7) Languages
Language information is defined along two data dimension: (i) language (ii) level of proficiency
(8) Special Expertises
In this field, certain free text data entry may be allowed to permit special expertise to be noted
In a preferred embodiment, the databases themselves are maintained on an Application Server which is accessed by the stated demand- or supply-side users. Information is input, e.g. using pull-down menus or free-text data entry, where permitted. The application server calculates, based on the information input by the user, a specific job position within the matrix and correlates specific pricing information, which may include salary ranges, median salary, etc.
The present invention may be used with Internet access technologies. This covers end user interfaces to the system of the present invention as well as machine-to-machine interfaces. Alternatively other network solutions may be used.
The end user interfaces may be browser-based, whereas the invention supports both desktop/laptop and mobile browsers. In this case the IP address information may be used as geo-data information. Messaging interfaces may support e-mail or SMS. When using mobile phones as interface, the available GSM or GPS position information may be used as geo-data information. The user interface related geo-data information may be used to verify the geo-data information provided by a job candidate and/or as access control means. Alternatively, other systems, such as voice-activated telephone services, may be used as interface.
As shown in FIG. 3 , machine-to-machine interfaces may be used with API's for xml-feeds or crawlers that automatically access end user interfaces of web sites and pull data.
One example of the architecture of that may be used for the application is described in FIG. 4 .
The positions within the job matrix may be limited to specified categories (e.g., 250 three-dimensional matrix positions/clusters), whereupon each position inquiry is forced into these positions. This allows the precise definition of each position and provides a more reliable specification of the provision, and therefore a more reliable pricing. It would also avoid double postings, making it less likely that the two different positions could define the same job.
Each job being accessible via system gets an individual salary-benchmark information (in the following: SBI). For postings entered directly by HR representatives of a company or by Head hunters, the SBI is created by the posting person himself, selecting the appropriate SBI level out of a proposed range-list. For postings being collected and categorised by systems to be accessible to the creators corporate website or his commissaries, the SBI is calculated automatically out of the system. The calculation of the SBI follows a process of job-categorisation along primary dimensions including industry, function, career level and secondary dimension like geographical factor (i.e. CIP code) or company size. Data sources of the salary database are:
1. external empirical information
surveys and data of national statistic offices (distribution of income, GDP per capita etc.)
agencies providing salary information
Corporate compensation information
2. internal information:
End user of the system insert salary information by
(a) Posting a job (HR departments or recruiters) and attaching salary information along with the primary and secondary dimensions applicable to a job.
(b) inserting candidate profile information, where an end user fills out its CV data and attaches a salary information to its current position, which is coded with the primary and secondary dimensions applicable to the respective job. (note: With every registration to the system of the present invention, the user has to select the annual gross-earnings of his last years profession out of a suggestions list offering defined ranges of earnings. When filling in an individual profile on the system—the system gathers the information of the current position corresponding to the date of sign-up including the dimensions of industry, function, career level and geographical factor of the individual position.)
The permanent analysis of all gathered user-information enables the system to provide an automatic and permanent adjustment of all salary-matrix information. Calculation algorithms used are based on statistical models as well as on averaging.
Another preferred embodiment of the present invention involves a so called matching process. The matching process provides a selection of relevant positions for a candidate, that is superior to the results of a search for a given list of criteria. This is shown in FIG. 5 .
As a prerequisite, a candidate provides information about the positions, he/she is interested in by
describing one or more career goals A minimum information of at least one of career level or salary expectations and one of targeted industries or functional area must be provided. Besides this information additional data like the names of companies the candidate is interested in, a list of expertises a candidate seeks to use, a list of countries and an area defined by a location and distance can be provided depending on the preferences of the candidate. describing his/her job history A candidate describes his professional experience by providing data on the positions he/she worked at. The system therefore knows about past functions and industries the candidates is experienced in. describing general expertises and skills A candidate lists special expert skills that makes him stand out from other candidates. describing her/his education describing the list of languages she/he is familiar with
For positions a list of classifications is maintained:
the industry the functional area career level the salary benchmark for the position the company the location required languages required education the description of the position
The matching process scores each position held in the system by comparing it's classification to the candidates direct (by career goal) and indirect (by the description of his/her history) description of the positions she/he is interested in. Matching is done for each career goal of the user independently.
Scoring uses a configurable system of weighting factors.
Weighting factors reflect the relative importance of the entered criteria.
Factors for industries and functions further depend on the values provided: the relative weight for industry matches and function matches depends on the functions in question, since some functions allow for easily changing the industry while others don't.
Weighting factors also distinguish between data provided in the career goal and data provided in the history of a candidate since the former is more relevant for the results a user seeks.
Depending on the input provided, a maximum score is calculated and a threshold is derived from this maximum score.
The dynamic calculation of the maximum and threshold scores allows to adapt the system to different degrees of user input. While the system works best for detailed career goals and history data, results are provided for brief goals with minimum input and no job history as well.
All positions that qualify for a score larger than the threshold are considered a match.
Within all matches the score provides a ranking criterion. A larger score means a better fit to the candidates interests.
The matching is implemented as a search for any of the information provided by the user using a full text index of the positions containing all information on the positions.
Thus all positions that do not have any overlap with the candidates matching criteria, that is positions that have a score of 0, are excluded from the matching process from the beginning.
All other positions that fit at least one criteria are scored in the sense described above.
Criteria—such as location and distance—that cannot be searched on a full text index, is implemented by filtering the result and modifying the score appropriately.
Finally the result list is filtered by removing all results having a score less than the required threshold score.
Matching provides results that are superior to the results of searching a number of criteria provided by the user as
the results of such a search are included in the matching result perfect matches will have the highest score and occur first, when sorting by score matching provides results that fail to fulfil all criteria but still are close to the characteristics a user searches for. These matches are likely to be relevant to the user as well. This allows to see chances in the proximity of the precise goal definition that would be invisible else. This is especially helpful for users where no perfect matches exist, that is users that would get an empty result in the case of a simple search.
Matching thus provides sophisticated means to enable the user to find relevant positions.
Although the invention has been described and pictured in a preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example, and that numerous changes in the details of construction and combination and arrangement of parts may be made without departing from the spirit and scope of the invention as hereinafter claimed.
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The present invention relates to a method for providing a virtual job market on a network comprising an application server and clients and/or electronic message systems allowing to input and output information, wherein the method comprises the following steps: providing primary dimensions information on industries, career levels and functional areas; providing secondary dimensions information on salary ranges and/or geo-data and/or educational information and/or languages and/or special expertises, entering the primary and secondary dimensions information in a three dimensional data base on the application server; collecting information chunks of open jobs and candidate profiles, and placing the information chunks in a distinct cell or number of cells in the three dimensional database. Further, the present invention relates to a system for providing a virtual job market on a network comprising an application server and clients and/or electronic message systems including at least a first database comprising candidate profiles, a second database comprising salary information and a third database comprising job information, wherein the information available in the three databases is matched in a three dimensional database model.
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FIELD OF THE INVENTION
[0001] The present invention relates to a storage system comprised of modular elements.
BACKGROUND TO THE INVENTION
[0002] It is known to require the use of storage systems, particularly those using drawers, which can be constructed in a modular fashion. One application in which such a storage system is used is in the retail of small items of metal hardware.
[0003] Known modular storage systems can be limited in strength and/or rigidity. The present invention seeks to provide a modular storage system which provides more rigidity than some known modular storage systems.
SUMMARY OF THE INVENTION
[0004] In accordance with one aspect of the present invention there is provided a modular storage system comprising a plurality of frame members, characterised in that each frame member has a first surface opposed to a second surface, and a first side surface opposed to a second side surface, wherein the frame member includes a first track and a second track extending along the frame member in a longitudinal direction, the first track protruding outwardly from the first surface and the second track protruding outwardly from the second side surface, the frame member further including a first groove and a second groove extending along the frame member in a longitudinal direction, the first groove being recessed inwardly of the second surface and the second groove being recessed inwardly of the first side surface, wherein the first groove is complementary in shape to the first track such that a first track of a first frame member may locate within the first groove of a second frame member, and the second groove is complementary in shape to the second track such that a second track of the first frame member may locate within the second groove of a third frame member.
[0005] Preferably, at least one of the first and second tracks is formed by the insertion of a bead within a third groove.
[0006] Advantageously, this allows the storage system to be constructed in a modular fashion in two dimensions.
[0007] In accordance with a second aspect of the present invention there is provided a modular storage system comprising a plurality of frame members, each frame member having a first surface opposed to a second surface, wherein the frame member includes a first track extending along the frame member in a longitudinal direction, the first track protruding outwardly from the first surface, the frame member further including a first groove extending along the frame member in a longitudinal direction, the first groove being recessed inwardly of the second surface, the first groove having a corresponding track on an opposing side of the second surface, wherein the first groove is complementary in shape to the first track such that a first track of a first frame member may locate within the first groove of a second frame member, and wherein, in use, a drawer may locate in relation to and slide along the tracks corresponding to the first groove.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0009] FIG. 1 is a perspective view of a first box extrusion used in the modular storage system of the present invention;
[0010] FIG. 2 is a perspective view of a second box extrusion used in the modular storage system of the present invention;
[0011] FIG. 3 is a perspective view of a first bridge extrusion used in the modular storage system of the present invention;
[0012] FIG. 4 is a perspective view of a second bridge extrusion used in the modular storage system of the present invention;
[0013] FIG. 5 is a perspective view of a T-piece extrusion used in the modular storage system of the present invention; and
[0014] FIG. 6 is a perspective view of a bead used in the modular storage system of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] Referring to the Figures, there is shown in FIG. 1 a frame member in the form of a first box extrusion 10 for use in a modular storage system. The first box extrusion 10 includes a top face 12 , a bottom face 14 , a first side face 16 and a second side face 18 . These four faces are substantially the same length, so as to form a substantially square shaped cross-section.
[0016] The top face 12 has an outwardly facing first surface 20 . The bottom face 14 has an outwardly facing second surface 22 . The first surface 20 is opposed to the second surface 22 .
[0017] The top face 12 includes two longitudinally extending first tracks 24 . Each first track 24 is located near, and parallel to, a side of the top face 12 . The first tracks 24 are formed by an apparent deformation in the cross sectional shape of the top face 12 , with the first tracks 24 protruding outwardly from the first surface 20 .
[0018] The bottom face 14 includes two longitudinally extending first grooves 26 . Each first groove 26 is located near, and parallel to, a side of the bottom face 14 . The first grooves 26 are directly beneath the first tracks 24 . The first grooves 26 are formed by an apparent deformation in the cross sectional shape of the bottom face 14 , with the first grooves 26 being recessed inwardly of the second surface 22 .
[0019] The first tracks 24 are complementary in shape to the first grooves 26 , such that a pair of first tracks 24 of a first frame member may locate, and slide longitudinally, within a pair of first grooves 26 of a second frame member, thus engaging the first and second frame members in a first, vertically aligned orientation.
[0020] The first grooves 26 have corresponding tracks extending inwardly of the bottom face 14 . In use, a drawer (not shown) may have locate in relation to, and slide along, the inwardly extending tracks. Preferably, the drawer has grooves which locate over the inwardly extending tracks, and when located on the tracks the base of the drawer is raised slightly above the bottom face 14 .
[0021] The first side face 16 has an outwardly facing first side surface 30 . The second side face 18 has an outwardly facing second side surface 32 . The first side surface 30 is opposed to the second side surface 32 .
[0022] The first side face 16 includes a longitudinally extending second groove 34 . The second groove 34 is located adjacent, and parallel to, a lower edge of the first side face 16 . The second groove 34 is formed by an apparent deformation in the cross sectional shape of the first side face 16 , with the second groove 34 being recessed inwardly of the first side surface 30 .
[0023] The second side face 18 includes a longitudinally extending third groove 36 . The third groove 36 is located adjacent, and parallel to, a lower edge of the second side face 18 . The third groove 36 is formed by an apparent deformation in the cross sectional shape of the second side face 18 , with the third groove 36 being recessed inwardly of the second side surface 32 .
[0024] The third groove 36 is arranged to receive a bead 38 , as shown in FIG. 6 . The bead 38 is longitudinally extending, and is substantially figure-8 shaped in cross section. The bead is sized such that one side of the figure-8 shape may be inserted within, and slid along, the third groove 36 . When in this position, the other side of the figure-8 shape forms a second track protruding from the second side surface 32 .
[0025] The second track is complementary in shape to the second groove 34 , such that a second track of a first frame member may locate, and slide longitudinally, within a second groove 34 of a second frame member, thus engaging the first and second frame members in a second, horizontally aligned orientation.
[0026] Whilst the modular storage system of the present invention may be constructed solely from first box extrusions 10 as described herein above, it may also use other types of frame members. One such frame member is a second box extrusion 40 as shown in FIG. 2 .
[0027] The second box extrusion 40 is rectangular in shape, with a height the same as that of the first box extrusion 10 and a width twice that of the first box extrusion 10 . The second box extrusion 40 has first and second side faces 16 , 18 identical to those of the first box extrusion 10 . The second box extrusion 40 has a top face 42 identical in shape to two top faces 12 of the first box extrusion 10 , joined side-by-side. The second box extrusion 40 has a bottom face 44 identical in shape to two bottom faces 14 of the first box extrusion 10 , joined side-by-side.
[0028] It will thus be appreciated that the second box extrusion 40 has four first tracks 24 across the top face 42 , with two located adjacent edges and two located substantially centrally. Similarly, the second box extrusion 40 has four first grooves 26 complementary in shape and position to the four first tracks 24 .
[0029] In use, two substantially square drawers may locate within, and slide within, the second box extrusion 40 . Alternatively, one rectangular drawer may be used.
[0030] The second box extrusion 40 may be joined horizontally to a first box extrusion 10 , or another second box extrusion 40 , by the same mechanism described with respect to the first box extrusion 10 .
[0031] The second box extrusion 40 may be joined vertically to two horizontally-connected first box extrusions 10 by location of the first tracks of one within the first grooves of another. Alternately, the second box extrusion 40 may be joined vertically to another second box extrusion 40 in a similar fashion.
[0032] Another possible frame member is a first bridge extrusion 50 , as shown in FIG. 3 . The first bridge extrusion 50 is comprised of a longitudinally extending, substantially flat member having the same width as the first box extrusion 10 . The first bridge extrusion 50 has a first, upper surface 52 and a second, lower surface 54 . A pair of longitudinally extending first tracks 24 are located near, and parallel to, the sides of the first bridge extrusion 50 . The first tracks 24 are formed by an apparent deformation in the cross sectional shape of the first bridge extrusion 50 , with the first tracks 24 protruding outwardly from the first surface 52 . Corresponding first grooves 26 are recessed inwardly of the second surface 54 .
[0033] The first bridge extrusion 50 has lip portions 56 at each side thereof. The lip portions include second and third tracks 58 , 59 extending outwardly.
[0034] In use, a first bridge extrusion 50 may be joined horizontally between two box extrusions 10 or 40 . Where this bridge extrusion 50 is within an array of box extrusions 10 , 40 , it may provide a location on which a drawer may be located, with side walls being provided by adjacent box extrusions 10 , 40 .
[0035] A second bridge extrusion 60 as shown in FIG. 4 may be used in a similar fashion. The second bridge extrusion 60 is the same width as the second box extrusion 40 , and is similar in shape to the top face 42 of the second box extrusion 40 , with lip portions 56 similar to that of the first bridge extrusion 50 .
[0036] A further frame member, in the form of a T-piece extrusion 70 , is shown in FIG. 5 . The T-piece extrusion 70 has a central wall 72 which is slightly smaller in height than the side faces 16 , 18 of the box extrusions 10 , 40 . The T-piece extrusion 70 has a top flange 74 perpendicular to the central wall 70 . The top flange 74 has two first tracks 24 located adjacent side edges thereof. The top flange 74 is sized such that the two first tracks 24 are spaced from each other by the same distance as the two centrally located first tracks 24 of a second box extrusion 40 .
[0037] The T-piece extrusion 70 has an elongate lower lip 76 which extends along the base of the central wall 72 .
[0038] In use, the T-piece extrusion 70 may be used within an array of frame members to provide a side wall as required, with adjacent bridge extrusions 50 , 60 providing tracks on which drawers maybe located. The elongate lower lip 76 of the T-piece extrusion 70 maybe complementary in shape to recesses 78 located in the lip portions 56 of the bridge extrusions 50 , 60 .
[0039] Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.
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A modular storage system comprises boxes and/or bridge frame members. The frame members each have longitudinal tracks and grooves, which allow members to be slotted together to form a rigid, 2-dimensional frame in which drawers can be inserted.
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FIELD OF THE INVENTION
[0001] This invention is generally related to oil and gas wells, and more particularly to automatically computing preferred locations of wells and production platforms in an oil or gas field.
BACKGROUND OF THE INVENTION
[0002] Determining the placement of wells is an important step in exploration and production management. Well placement affects the performance and viability of a field over its entire production life. However, determining optimum well placement, or even good well placement, is a complex problem. For example, the geology and geomechanics of subsurface conditions influence both drilling cost and where wells can be reliably placed. Well trajectories must also avoid those of existing wells. Further, wells have practical drilling and construction constraints. Constraints also exist at the surface, including but not limited to bathymetric and topographic constraints, legal constraints, and constraints related to existing facilities such as platforms and pipelines. Finally, financial uncertainty can affect the viability of different solutions over time.
[0003] There is a relatively long history of research activity associated with development of automated and semi-automated computation of field development plans (FDPs). Most or all studies recognize that this particular optimization problem is highly combinatorial and non-linear. Early work such as Rosenwald, G. W., Green, D. W., 1974 , A Method for Determining the Optimum Location of Wells in a Reservoir Using Mixed-Integer Programming, Society of Petroleum Engineering Journal 14 (1), 44-54; and Beckner, B. L., Song, X., 1995, Field Development Planning Using Simulated Annealing , SPE 30650; and Santellani, G., Hansen, B., Herring, T., 1998 , “Survival of the Fittest” an Optimized Well Location Algorithm for Reservoir Simulation, SPE 39754; and Ierapetritou, M. G., Floudas, C. A., Vasantharajan, S., Cullick, A. S., 1999, A Decomposition Based Approach for Optimal Location of Vertical Wells in American Institute of Chemical Engineering Journal 45 (4), pp. 844-859 is based on mixed-integer programming approaches. While this work is pioneering in the area, it principally focuses on vertical wells and relatively simplistic static models. More recently, work has been published on a Hybrid Genetic Algorithm (“HGA”) technique for calculation of FDPs that include non-conventional, i.e., non-vertical, wells and sidetracks. Examples of such work include Guiyaguler, B., Home, R. N., Rogers, L., 2000, Optimization of Well Placement in a Gulf of Mexico Waterflooding Project, SPE 63221; and Yeten, B., Durlofsky, L. J., Aziz, K., 2002, Optimization of Nonconventional Well Type, Location and Trajectory, SPE 77565; and Badra, O., Kabir, C. C., 2003, Well Placement Optimization in Field Development, SPE 84191; and Guiyaguler, B., Home, R. N., 2004, Uncertainty Assessment of Well Placement Optimization, SPE 87663. While the HGA technique is relatively efficient, the underlying well model is still relatively simplistic, e.g., one vertical segment down to a kick-off depth (heal), then an optional deviated segment extending to the toe. The sophistication of optimized FDPs based on the HGA described above has grown in the past few years as the time component is being included to support injectors, and uncertainty in the reservoir model is being considered. Examples include Cullick, A. S., Heath, D., Narayanan, K., April, J., Kelly, J., 2003, Optimizing multiple-field scheduling and production strategy with reduced risk, SPE 84239; and Cullick, A. S., Narayanan, K., Gorell, S., 2005, Optimal Field Development Planning of Well Locations With Reservoir Uncertainty, SPE 96986. However, improved automated calculation of FDPs remains desirable.
SUMMARY OF THE INVENTION
[0004] An automated process for determining the surface and subsurface locations of producing and injecting wells in a field is disclosed. The process involves planning multiple independent sets of wells on a static reservoir model using an automated well planner. The most promising sets of wells are then enhanced with dynamic flow simulation using a cost function, e.g., maximizing either recovery or economic benefit. The process is characterized by a hierarchical workflow which begins with a large population of candidate targets and drain holes operated upon by simple (fast) algorithms, working toward a smaller population operated upon by complex (slower) algorithms. In particular, as the candidate population is reduced in number, more complex and computationally intensive algorithms are utilized. Increasing algorithm complexity as candidate population is reduced tends to produce a solution in less time, without significantly compromising the accuracy of the more complex algorithms.
[0005] In accordance with one embodiment of the invention, a method of calculating a development plan for at least a portion of a field containing a subterranean resource, comprises the steps of: identifying a population of target sets in the field; reducing this population by selecting a first sub population with a first analysis tool; reducing the first sub population by selecting a second sub population of target sets with a second analysis tool, the second tool utilizing greater analysis complexity than the first analysis tool; calculating FDPs from the second sub population of target sets; and presenting the FDPs in tangible form.
[0006] In accordance with another embodiment of the invention, a computer-readable medium encoded with a computer program for calculating a development plan for at least a portion of a field containing a subterranean resource, comprises: a routine which identifies a population of target sets in the field; a routine which reduces the population of target sets by selecting a first sub population of the target sets with a first analysis tool; a routine which reduces the first sub population by selecting a second sub population of target sets with a second analysis tool, the second tool utilizing greater analysis complexity than the first analysis tool; a routine which calculates a FDP from the second sub population of target sets; and a routine which presents the FDPs in tangible form.
[0007] Further features and advantages of the invention will become more readily apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0008] FIG. 1 is a flow diagram which illustrates automated computation of locations of wells and production platforms in an oil or gas field.
[0009] FIG. 2 illustrates an exemplary field used to describe operation of an embodiment of the invention.
[0010] FIG. 3 illustrates a target selection algorithm.
[0011] FIG. 4 illustrates placement of targets in the field of FIG. 2 .
[0012] FIG. 5 illustrates a drain hole selection algorithm.
[0013] FIG. 6 illustrates a reservoir trajectory selection algorithm.
[0014] FIG. 7 illustrates selected drain holes and reservoir trajectories in the field of FIG. 2 .
[0015] FIG. 8 illustrates an overburden trajectory selection algorithm and FDP selection algorithm.
[0016] FIG. 9 illustrates selected overburden trajectories and production platform locations in the field of FIG. 2 .
[0017] FIG. 10 illustrates an alternative embodiment in which geomechanical and facilities models are utilized to further refine the population of trajectory sets.
DETAILED DESCRIPTION
[0018] FIG. 1 illustrates a technique for automated computation of a FDP including locations of wells and production platforms in an oil or gas field. Workflow is organized into five main operations: target selection ( 100 ), drain hole selection ( 102 ), reservoir trajectory selection ( 104 ), overburden trajectory selection ( 106 ), and FDP selection ( 108 ).
[0019] The target selection operation ( 100 ) is initialized by generating a large initial population ( 112 ) of target sets from a geological model ( 110 ). For example, 1000 different target sets might be generated, although the actual population size is dependent on the complexity of the field and other considerations. Each member of the population is a complete set of targets to drain the reservoir(s), and each target is characterized by an estimate of its value. For example, a simple value estimate is the associated stock tank oil initially in place (“STOIIP”). In subsequent operations, the large initial population of target sets is gradually reduced in size as each step progressively identifies the more economically viable subsets of the population.
[0020] The drain hole selection operation ( 102 ) includes generating a population ( 114 ) of drain-hole sets from the target population ( 112 ). Each drain hole is an ordered set of targets that constitutes the reservoir-level control points in a well trajectory. Each member of the generated population ( 114 ) is a complete set of drain holes to drain the reservoir(s). Each drain hole set comprises targets from a single target set created in the previous operation. It should be noted that multiple drain hole sets may be created for a single target set. Each drain hole set has an associated value which could be, for example and without limitation, STOIIP, initial flow rate, decline curve profile, or material balance profile.
[0021] The reservoir trajectory selection operation ( 104 ) includes generating a population ( 116 ) of trajectory sets from the drain hole population ( 114 ). In particular, each member of the generated population ( 116 ) represents a completion derived from the corresponding drain-hole set created in the previous operation ( 102 ). Each well trajectory is a continuous curve connecting the targets in a drain hole. At the end of this operation ( 104 ), the approximate economic value of each trajectory set is evaluated based on the STOIIP values of its targets and the geometry of each well trajectory. These values are used to reduce the size of the population by selecting the population subset with the largest economic values, i.e., the “fittest” individuals. For example, by selecting the “fittest” 10% of individual subsets, the size of the population can be reduced by one order of magnitude, e.g., from 1000 to 100.
[0022] In the overburden trajectory selection operation ( 106 ) each trajectory in the remaining population ( 116 ) of trajectory sets created in the previous operation ( 104 ) is possibly modified to account for overburden effects such as drilling hazards. At the end of this operation ( 106 ) the approximate economic value of each trajectory set is evaluated using STOIIP and geometry, as in the previous operation, but also with respect to drilling hazards. The “fittest” individuals with respect to economic value are then selected and organized into a population ( 118 ) for use in the next operation ( 108 ). For example, by selecting the “fittest” 10% of these individuals it is possible to further reduce the size of the population by another order of magnitude, e.g., from 100 to 10.
[0023] The FDP selection operation ( 108 ) includes performing rigorous reservoir simulations on the remaining relatively small population ( 118 ) of trajectory sets, e.g., 10. The economic value of each member of the population is evaluated using trajectory geometry, drilling hazards and the production predictions of the reservoir simulator. These values can be used to rank the FDPs in the remaining small population. The FDP with the greatest rank may be presented as the selected plan, or a set of greatest ranked plans may be presented to permit planners to take into account factors not included in the automated computations, e.g., political constraints. The result is a FDP population ( 120 ).
[0024] A particular embodiment of the workflow of FIG. 1 will now be described with regard to the exemplary field illustrated in FIG. 2 . The illustrated field includes discrete hydrocarbon reservoirs ( 200 ) with boundaries defined by subterranean features such as faults. STOIIP is indicated by color intensity, where green is indicative of greater STOIIP, and blue is indicative of lesser STOIIP.
[0025] FIGS. 3 and 4 illustrate an embodiment of target set generation and selection in greater detail. The number of illustrated targets ( 40 ) is relatively small for clarity of illustration and ease of explanation. As stated above, each member of the population is a complete set of targets to drain the reservoir(s). A series of steps are executed to identify all valid cells in the reservoir model that could be potential well targets, and create a list of valid cells, i.e., Valid Cell List (“VCL”). A potential cell is selected as indicated by step ( 300 ). The value of the selected cell is then compared with a threshold as indicated by step ( 302 ). Valid cells are characterized by one or more of a minimum value of STOIIP, minimum recovery potential, and analogous selection criteria. If the selected cell is valid, it is added to the VCL as indicated by step ( 304 ). This process continues until reaching the end of the cell list, as indicated by step ( 306 ). A connected volume analysis is then performed, as indicated by step ( 308 ), assigning each cell a volume id. Cells with the same volume id are considered hydraulically contiguous. Tools for performing this analysis exist in modern interpretation software, e.g., Petrel 2007. The next steps ( 310 , 312 ) are associated with initialization: create an empty Target Set Population (“TSP”), an empty Target Set (“TS”), and a Target Set Valid Cell List (“TSVCL”) by copying the VCL. The next step is to randomly select a target, as indicated by step ( 314 ), i.e., randomly selecting a cell from the TSVCL. The next step ( 316 ) is to analytically identify all the hydraulically contiguous cells that could be drained by a completion at the center of the cell. Target cost and value are calculated as indicated by step ( 318 ). The value of the target is the total STOIIP of the drained cells. The cost of the target is the cost of a vertical well to the center of the target cell, and the net value is then given by the value minus the cost. If the net value is positive, as determined in step ( 322 ), then the target is added to the TS as indicated in step ( 324 ). If net value is negative, as determined in step ( 322 ), then target should not be added to the TS. In that case, step ( 324 ) tests if consecutive failures (negative nets) is greater than a maximum. If true, then control passes to step ( 330 ), else control passes back to step ( 314 ), and a new target is selected from the TSVCL. If the target cell is added to the TS, as shown in step ( 324 ), the target cell and additional drained cells are then removed from the TSVCL, as indicated by step ( 326 ). Target selection (step 314 ) is repeated for remaining cells in the TSVCL until no cells remain in TSVCL, as determined at step ( 328 ). The populated TS is added to TSP as indicated in step ( 330 ). Flow returns to step ( 312 ), unless the TSP has reached desired size or unique target sets cannot be found, as indicated in step ( 332 ).
[0026] An embodiment of drain hole selection is illustrated in greater detail in FIGS. 5 and 7 . The population of drain hole sets is generated as already described, where each member of the population is a complete set of drain holes to drain the reservoir(s) (one set of drain holes ( 700 ) is shown). The procedure initially creates a Drain Hole Set Population (“DHSP”) container which will contain a population Drain Hole Sets (“DHS”) as shown in step ( 500 ). The procedure then loops over each TS in the TSP, selecting the current TS, as shown in step ( 502 ). A Drain Hole Set (“DHS”) is generated by converting the TS into a DHS as indicated by step ( 504 ). In this case, each target in the TS becomes a single target Drain Hole (DH). The value of the DH is the value of the target. The cost of the DH is the cost of a vertical well to the target. This initial DHS is added to the DHSP as indicated by step ( 506 ). For the current TS, new DHSs are created by stochastically combining DHs from the existing initial DHS as indicated by step ( 508 ). For the combination of each DH into a new merged DH to be valid, each node in the resulting DH must be deeper than the preceding node. The value of the resulting DH may be computed in a number of ways. One way to compute the value of the DH is the STOIIP available for drainage by the DH. To be available, it must be in the same connected volume as the DH and must be closer to the current DH than another valid DH. The initial flow rate is computed as an analytical approximation to a reservoir simulator formulation. A decline curve profile is computed by combining the STOIIP with an initial flow rate, and then using a simple decline curve to produce a profile for the well, and then calculating a net present value (NPV), or net production. Finally, using the STOIIP and initial rate as discussed above, a material balance calculation is performed to produce a production profile for the well to calculate NPV. This is effectively doing a one cell simulation. The cost of the DH is the sum of analytically computed cost of each segment of the DH and the vertical segment to the surface. For a given TS, step ( 508 ) is repeated either until the maximum number of DHSs per TS is exceeded, or no new unique DHSs are found, or no new DHSs with positive net value are found. Steps ( 502 ) through ( 508 ) are repeated until the TSP is empty, as indicated by step ( 510 ).
[0027] An embodiment of reservoir trajectory selection is illustrated in greater detail by FIGS. 6 and 7 . A population of trajectory sets (TJSP) is generated as already described, where each member of the population is derived from the corresponding DHS in the previously created DHSP. As shown in step ( 600 ), geometrically valid trajectories ( 900 ) are computed using the existing well trajectory optimizer in Petrel. Note that the existing well trajectory optimizer honors both the DH locations and surface constraints such as limits on platform location and cost. One trajectory is created for each DH. To allow for a geometrically valid trajectory, the location of each node in the DH can shift within the bounds of the cell. As shown in step ( 602 ), the value of each trajectory is set to the previously computed value of the DH. A possible extension of the well trajectory optimizer would take each DHS to as an initial condition for the optimization, but would allow the DH connections between targets to be adjusted if this lowers the cost of the DHS. As shown in step ( 604 ), the cost of each trajectory is set to the cost of the trajectory computed by the optimizer. If the cost of a trajectory exceeds the value, as determined in step ( 606 ), then this trajectory may be eliminated. The trajectory cost also includes surface constraints. For example, platform costs can be determined by bathymetry, and distance from surface facilities can be determined from surface cost maps. In the final step ( 608 ), the size of the resulting TJSP is reduced to provide the highest net (value−cost) subset. The reduction could be in the order of a factor of 10.
[0028] An embodiment of overburden trajectory selection is illustrated in greater detail by FIGS. 8 and 9 . In this embodiment the TJSP created in the previous step ( 608 , FIG. 6 ) is modified to optimize for overburden effects such as drilling hazards. As shown in step ( 800 ), a Cost Tensor Grid (“CTG”) is generated for the overburden to define the costs of drilling and construction through the overburden. Each cell in the overburden now has a cost associated with drilling through that cell. The cost is a tensor because it may be relatively inexpensive to drill in one direction while relatively expensive to drill in another direction. For example, if a cell is associated with an east-west striking fault, it might be expensive to drill parallel to the fault (east-west), but relatively inexpensive to drill normal to the fault (north-south). The CTG can be computed with a geomechanical engine, e.g., OspreyRisk. For each trajectory set (TJS) in the TJSP, the existing well trajectory optimizer is executed to compute new trajectories that use the CTG as part of the objective function as indicated by step ( 802 ). The size of this new TJSP is reduced as indicated by step ( 804 ) to produce a highest net (value−cost) subset. The reduction could be in the order of a factor of 10.
[0029] FDP Selection is performed on the relatively small TJSP produced from the previous step. The operation includes rigorous reservoir simulations. As illustrated by step ( 806 ), for each TJS in TJSP, a full reservoir simulation is performed. The financial value of the reservoir production streams, possibly expressed as a net present value (NPV)NPV, may be utilized to rank members of the TJSP. As shown in step ( 808 ), results are then presented in tangible form, such as printed, on a monitor, and recorded on computer readable media. For example, the member with the greatest NPV and the ranking may be presented.
[0030] Referring now to FIG. 10 , in an alternative embodiment additional models and analysis tools are utilized to further refine the TJSP in a platform optimization step ( 1000 ) before calculating NPV. In particular, a sophisticated single well risk and costing tool (e.g. Osprey Risk) ( 1002 ) may be utilized on a geomechanical model ( 1004 ) to refine the TJSP based on subsurface stresses. Further, an integrated asset management too (e.g. Avocet) ( 1006 ) may be used on a facilities model ( 1008 ) to refine the TJSP based on subsurface constraints such as locations of existing facilities like delivery pipelines. In this embodiment, a high speed reservoir simulator (e.g. FrontSim ( 1010 )) and a high precision reservoir simulator (e.g. Eclipse) ( 1012 ) operate on the geological model. Other models and analysis tools may also be utilized.
[0031] The embodiments outlined above operate on a single “certain” geological, geomechanical and facilities model. Modem modeling tools such as Petrel 2007 allow “uncertain” earth models to be generated. The invention described here could be implemented within this context so that an “uncertain” FDP would be generated. An uncertain earth model is typically described through multiple realizations of certain earth models. As such, an embodiment of an uncertain FDP would be through multiple realizations.
[0032] It is important to recognize that because of unknown and incalculable factors, the most successful, robust and efficient realization may differ from the results of the computation. Further, it is important to note that different problems may demand different realizations of the algorithm.
[0033] While the invention is described through the above exemplary embodiments, it will be understood by those of ordinary skill in the art that modification to and variation of the illustrated embodiments may be made without departing from the inventive concepts herein disclosed. Moreover, while the preferred embodiments are described in connection with various illustrative structures, one skilled in the art will recognize that the system may be embodied using a variety of specific structures. Accordingly, the invention should not be viewed as limited except by the scope and spirit of the appended claims.
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A hybrid evolutionary algorithm (“HEA”) technique is described for automatically calculating well and drainage locations in a field. The technique includes planning a set of wells on a static reservoir model using an automated well planner tool that designs realistic wells that satisfy drilling and construction constraints. A subset of these locations is then selected based on dynamic flow simulation using a cost function that maximizes recovery or economic benefit. In particular, a large population of candidate targets, drain holes and trajectories is initially created using fast calculation analysis tools of cost and value, and as the workflow proceeds, the population size is reduced in each successive operation, thereby facilitating use of increasingly sophisticated calculation analysis tools for economic valuation of the reservoir while reducing overall time required to obtain the result. In the final operation, only a small number of full reservoir simulations are required for the most promising FDPs.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 09/923,688, filed Aug. 6, 2001, now U.S. Pat. No. 6,486,552, issued Nov. 26, 2002, which is a continuation of application Ser. No. 09/521,592, filed Mar. 9, 2000, now U.S. Pat. No. 6,303,993 B 1, issued Oct. 16, 2001, which is a divisional of application Ser. No. 08/994,004, filed Dec. 18, 1997, now U.S. Pat. No. 6,140,827, issued Oct. 31, 2000.
BACKGROUND OF THE INVENTION
The present invention relates generally to semiconductor manufacturing and, more particularly, to methods for testing semiconductor dice having raised or bumped bond pads. More particularly still, the present invention relates to fabricating and using a testing grid suitable for testing solder balls used for bumped bond pads on an unpackaged semiconductor die.
Semiconductor dice are being fabricated with raised bond pads and are known as bumped semiconductor die. A bumped semiconductor die includes bond pads along with bumped solderable material such as a lead-tin alloy. These typically are manufactured from solder balls made of a lead-tin alloy. Bumped dies are often used for flip-chip bonding where the die is mounted face down on the substrate, such as a printed circuit board, and then the die is attached to the substrate by welding or soldering. Typically, the bumps are formed as balls of materials that are circular in a cross-sectional plane parallel to the face of the die. The bumps typically have a diameter of from 50 micrometers (μm) to 100 μm. The sides of the bumps typically bow or curve outwardly from a flat top surface. The flat top surface forms the actual region of contact with a mating electrode on the printed circuit board or other substrate. In testing the attached solder bumps, a temporary electrical connection must be made between the contact locations or bond pads on the die and the external test circuitry associated with the testing apparatus. The bond pads provide a connection point for testing an integrated circuit on the die. Likewise, the integrity of each bump must be tested as well.
In making this temporary electrical connection, it is desirable to effect a connection that causes as little damage as possible to the bumped die. If the temporary connection to the bumped bond pad damages the pad, the entire die may be ruined. This is difficult to accomplish because the connection must also produce a low resistance or ohmic contact with the bumped bond pad. A bond pad, with or without a bump, typically has a metal oxide layer formed over it that must be penetrated to make the ohmic contact.
Some prior art contact structures, such as probe cards, scrape the bond pads and wipe away the oxide layer. This causes excess layer damage to the bond pads. Other interconnect structures, such as probe tips, may pierce the oxide layer and metal bond pad and leave a deep gouge. Still other interconnect structures, such as micro bumps, cannot even pierce the oxide layer, preventing the formation of an ohmic contact.
In the past, following testing of a bump pad die, it has been necessary to reflow the bumps, which are typically damaged by the procedure. This is an additional process step that adds to the expense and complexity of the testing process. Furthermore, it requires heating the tested die that can adversely affect the integrated circuitry formed on the die.
Other bond pad integrity testing systems have been developed in the prior art. Typically, these testing systems use optical imaging to determine the integrity of the weld connection on the bumped sites. One type of system is a profiling system that uses interferometry with robotic wafer handling to automate the testing step. The testing step develops a profile for measuring solder bump heights. Unfortunately, although the interferometry system does not damage the device in any way, the time required for analyzing each bump location can take from two to four minutes. This type of throughput is unacceptable when a high speed system is necessary.
Accordingly, what is needed is a method and system for testing solder bumps in bond pad locations that does not damage the bond pads while improving throughput.
SUMMARY OF THE INVENTION
According to the present invention, a method and apparatus for testing unpackaged semiconductor dice having raised contact locations are disclosed. The apparatus uses a temporary interconnect wafer that is adapted to establish an electrical connection with the raised ball contact locations on the die without damage to the ball contacts. The interconnect wafer is fabricated on a substrate, such as silicon, where contact members are formed in a pattern that matches the size and spacing of the contact locations on the die to be tested. The contact members on the interconnect wafer are formed as either pits, troughs, or spike contacts. The spike contacts penetrate through the oxide layer formed on the raised ball contact location. Conductive traces are provided in both rows and columns and are terminated on the inner edges of the walls of the pits formed in the substrate. This arrangement allows a system to measure the continuity across the bump pad or ball contact locations of the integrated circuit die in order to establish that each ball contact location is properly attached. This also allows the system to test for the presence and quality of the bump or ball contact locations on the particular die being tested.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a schematic cross-sectional diagram of a pit formed in a substrate wherein a solder ball is received;
FIG. 2 is a cross-sectional perspective schematic view of the pit according to FIG. 1 ;
FIG. 3 is a top plan view of an array of pits according to that of FIG. 1 having a metal interconnect in a form of rows and columns;
FIG. 4 is an alternative embodiment of the pit of FIG. 1 wherein raised supports are provided along with sharp blades for penetrating the ball;
FIG. 5 is an alternative embodiment of the pit of FIG. 1 wherein raised portions are provided for penetrating the solder balls;
FIG. 6 is an example of a solder ball being out of place and failing to make adequate connection between adjacent metal bonds;
FIG. 7 is an example of when a ball that is too small has been identified;
FIG. 8 is a schematic cross-sectional view of a device under test where mismatched balls are adjacent to one another; and,
FIG. 9 is a block diagram of a test apparatus using the bump plate according to FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional schematic view of a bump plate 10 for testing the connect conductivity and quality of a solder ball on an unpackaged semiconductor die. Bump plate 10 is fabricated in a semiconductor substrate 12 , such as, for example, silicon, gallium arsenide, or silicon on sapphire, to name a few.
A plurality of receiving pits 14 is formed in the surface of substrate 12 . Receiving pit 14 can be any desired polygonal or curved shape, but is preferred to be square with four sloped sidewalls 16 . Each sidewall 16 is at an angle of 54° from horizontal, conforming to the plane of the surface of the silicon substrate that can be used in fabricating bump plate 10 . After pits or suitable features are etched (formed), the surface of the plate is coated with a thin layer insulator of about 200-300 Angstroms (such as Si Oxide) before the metal traces are formed. Electrical connection for testing for the presence of the solder balls on the die is provided by metal traces 18 . Metal traces 18 are made from a suitable metal and extend across the surface of substrate 12 and down sidewalls 16 of receiving pit 14 . A solder ball or bump 20 can then be positioned within receiving pit 14 and contact all four sloped sidewalls 16 . Ball 20 is placed within receiving pit 14 when a die under test is mated with bump plate 10 . Since a metal trace 18 is placed on each sidewall 16 and extends across the surface of substrate 12 to an adjacent receiving pit 14 , an applied electric current can flow through metal traces 18 provided the solder ball 20 contacts both sides of sidewall 16 and metal trace 18 thereon.
A method that is adaptable for manufacturing bump plate 10 is described in U.S. Pat. No. 5,592,736, “Fabricating An Interconnect For Testing Unpackaged Semiconductor Dice Having Raised Bond Pads,” commonly assigned to the same assignee as the present invention, and herein incorporated by reference for all purposes.
FIG. 2 depicts, in a cross-sectional perspective view, receiving pit 14 prior to the addition of metal trace 18 of FIG. 1 . Receiving pit 14 has a substantially flat bottom surface that is non-conductive as well as four adjacent sidewalls 16 , again having the slope angle that naturally slopes 54° in the surface plane of silicon substrate 12 as it is etched. The sloped sidewall 16 allows for a spherical ball 20 to seat within receiving pit 14 without damaging the bottom curvature of ball 20 while still contacting metal trace 18 that extends down the slope of sidewall 16 .
Bump plate 10 has a plurality of receiving pits 14 and is shown in the schematic diagram of FIG. 3 . Bump plate 10 actually is an array of receiving pits 14 that is electrically connected in rows and columns using metal traces 18 . Horizontal metal traces 18 run across the surface of substrate 12 and down the sloped sidewalls 16 of the receiving pits 14 . It is important that metal traces 18 do not connect with one another within receiving pits 14 . As an electric current is placed across each row and down each column in a sequential manner, it becomes readily apparent at each receiving pit 14 location whether a ball exists or the connection is of such poor quality as to provide no conduction across the row or down the column. From this information, a grid map of the defects can be established that will allow repair of the missing or poor quality bumped locations at a subsequent repair stage.
Alternative embodiments to receiving pits 14 within the substrate 12 are shown in FIGS. 4 and 5 . FIG. 4 illustrates a raised contact location 30 for contacting the bottom surface of a solder ball 20 . Each raised contact location 30 comprises a set of side bumps 32 that form a valley 36 . A plurality of sharpened projections 34 is formed within valley 36 and is designed to pierce the oxide layer formed over ball 20 and can be attached to adjacent metal traces 18 for providing good ohmic contact to adjacent metal traces 18 with ball 20 for testing purposes. Contact location 30 can be in the shape of a polygon or circle and can be combined with receiving pits 14 of FIG. 3 .
FIG. 5 is an alternative embodiment where each receiving pit 14 is replaced with a post trough 40 , which is formed by a plurality of posts 42 to form a polygon, such as a square. Posts 42 are formed such that a valley 44 is formed in post trough 40 . Metal traces are formed up and down the sides of post 42 , but not connecting one another in the same manner as traces 18 in FIG. 3 . Thus, when a ball 20 is placed in a post trough 40 , a good ohmic connection forms between opposite traces 18 for conducting a test current. Further, post trough 40 can be in the shape of a polygon or circle and can be combined with receiving pits 14 of FIG. 3 or contact locations 30 of FIG. 4 .
Each of the embodiments of FIGS. 1-5 is capable of testing for various types of solder ball conditions. The most significant is when a missing ball occurs. This is simple to detect in that no current will flow either across the column or down the row when the test current is applied. Other examples are also possible and are illustrated in FIGS. 6 , 7 , and 8 . FIG. 6 is an example of when a solder ball 20 is off center and only contacts one or two sides of receiving pit 14 , thus preventing a good current signal from passing either across the column or down the row. FIG. 7 is an example of a ball 20 too small to touch any sides in receiving pit 14 . In this condition, no current can pass and it is viewed as being that no solder ball is present. FIG. 8 depicts where adjacent balls of different sizes are attached to die 50 . A first ball 20 has a first diameter and a second ball 52 has a second diameter, which is much smaller than the first diameter of ball 20 . As is shown, ball 20 is an appropriate size and contacts well with the sides of receiving pit 14 . By contrast, ball 52 is too small to even reach receiving pit 14 , so the current signal test shows it as not being present at all. Of course, the reverse can be true in that ball 52 is actually the desired size of the balls while ball 20 is an aberration and is much larger than desired. This would also be evident in that many balls would be seen as not being present as the diameter of ball 20 would prevent several adjacent balls from contacting in their respective pits.
FIG. 9 depicts a test apparatus 54 that uses a bump plate 10 . Apparatus 54 comprises a signal processor, such as a computer system 56 , that attaches to a bump plate 10 . Electrical signals or current are passed to bump plate 10 along the rows and columns of the metal traces 18 to establish a test pattern. A device under test (DUT) 58 is pressed upon bump plate 10 to match the solder ball pattern to the identical pattern fabricated on bump plate 10 . Once contact is made, the test is begun and the results are obtained more quickly compared to prior art test apparatus using optical or other mechanical means previously described.
The bump die wafer inspection apparatus of the present invention offers the following advantages over the prior art. As the electronic world moves toward stencification miniaturization, better methods for testing these technologies are needed and this solution provides an advancement over those previously available and, using semiconductor fabrication techniques, a bump plate matching a desired solder ball pattern for a particular die can be generated. The silicon or other similar substrates serve as a rigid medium, and as a result of this rigidity, they have a fixed dimensional test capability for each bump/ball testing site. This limits its use with regard to the range of the dimensional tolerances that it can test. This is significant in that the bumps, or balls, or both, require tight dimensional tolerances to pass such testing. The silicon micro-machining and photolithography processes allow much more precise geometry control than the printed circuit board (PCB) or film technologies found in the prior art. Hence, a more definitive distinction and grading is made for each ball shape and position. Additionally, the present apparatus provides a unique methodology for electronically mapping the failing ball sites and then utilizing this map to direct a repair or rework system to correct each failing site. These operations of testing, mapping, and subsequent repair can be combined in a highly automated in-line process, thus reducing the necessary steps previously required in the prior art of removing the bad boards and sending them to the rework section of the fabrication operation.
Another advantage is since the semiconductor substrate can be planarized to a uniform flatness compared to the PCB and other processing solutions, less damage is caused to the good solder balls attached to the DUT.
Thus the invention provides an improved method and system for testing a discrete, unpackaged semiconductor die having raised bond pads. Although specific materials have been described, it is understood that other materials can be utilized. Furthermore, although the method of the invention has been described with reference to certain specific embodiments as will be apparent to those skilled in the art, modifications can be made without departing from the scope of the invention as defined in the following claims.
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An apparatus for testing unpackaged semiconductor dice having raised ball contact locations is disclosed. The apparatus uses a temporary interconnect wafer that is adapted to establish an electrical connection with the raised ball contact locations on the die without damage to the ball contact locations. The interconnect is fabricated on a substrate, such as silicon, where contact members are formed in a pattern that matches the size and spacing of the ball contact locations on the die to be tested. The contact members on the interconnect wafer are formed as either pits, troughs, or spike contacts. The spike contacts penetrate through the oxide layer formed on the raised ball contact locations. Conductive traces are provided in both rows and columns and are terminated on the inner edges of the walls of the pits formed in the substrate.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a noncircular cooling bore, in particular for the film cooling of a wall in a hot-gas environment. The invention also relates to a method of producing a noncircular cooling bore.
2. Discussion of Background
To increase the output and the efficiency, increasingly higher turbine inlet temperatures are being used in modern gas-turbine plants. In order to protect the turbine blades from the increased hot-gas temperatures, they must be intensively cooled. At correspondingly high inlet temperatures, purely convective cooling is no longer sufficient. The film-cooling method is therefore often used. In this case, the turbine blades are protected from the hot gas by a cooling film. To this end, openings, for example bores, through which the cooling air is blown out, are made in the blades.
In order to achieve as high a cooling effect as possible, the cooling air which is blown out must be deflected as rapidly as possible and flow in a protective manner along the profile surface. In order to also protect the zones lying between the bores, rapid lateral spreading of the cooling air is also necessary. This may be achieved by the cooling-air bores having a diffuser, which on account of the lateral widening permits a wider area of the surface to be covered. To further improve the mixing behavior, geometrical diffuser forms in which the bore is widened not only laterally but also on the downstream side of the bore are used.
For example, publication EP-B-228 338 describes a cooled wall having a cooling-medium passage, the diffuser section of which widens laterally toward the cooling-medium outlet and the downstream flat surface of which diverges away from the axis.
The blow-out rates in the case of these geometrical diffuser forms are small, so that there is little risk of the cooling air passing through the flow boundary layer. The cooling efficiency can therefore be increased considerably compared with a cylindrical bore.
The accuracy with which the workpieces to be provided with cooling holes must be produced represents a significant cost factor. Large wall tolerances of up to 10% or even up to 20% permit the components to be produced cost-effectively. On the other hand, the fluctuations in the wall thickness lead to variations in the opening ratio of the cooling bores as a function of the wall thickness. The accompanying non-uniform film-cooling effectiveness leads either to the costly redesign of the weakest points or to the occurrence of overheated spots on the wall surface, a factor which drastically reduces the service life of the component.
The production of such holes by a spark-machining machining method, as described, for instance, in publication U.S. Pat. No. 4,197,443, has, in addition to the high production costs, the disadvantage that the use of a spark-machining grid, even in the case of small surface tolerances, leads to greatly varying opening ratios of the individual cooling holes. In addition, the spark-machining method cannot be used in the case of ceramically coated surfaces, since the latter are electrically insulating. In this case, the cooling holes must be produced before the coating. The subsequent coating generally covers part of the diffuser opening, as a result of which the cooling properties of the holes are affected. It then becomes necessary to remove the obstructing material in a further step of the method. For example, publication U.S. Pat. No. 5,216,808 describes a method of producing or repairing a gas-turbine component. In this case, after a protective coating has been applied to the component, a UV laser beam is directed toward the position of a film-cooling hole in order to remove obstructing coating material athermally.
In the laser drilling of turbine blades, two drilling methods are mainly used. In percussion drilling, a hole is bored to the nominal diameter by a number of laser pulses with a beam axis fixed relative to the workpiece. With this method, however, only cylindrical holes are easy to produce. In the trepanning drilling method, a finely focused laser beam is moved relative to the workpiece and the hole is thus cut out. In the production of cooling holes having a diffuser by a laser-drilling method, the problem occurs that the length of the cylindrical air-inlet passage also increases as the wall thickness increases. This inlet passage is damaged by the laser beam during the cutting-out of the widening diffuser. The sharp-edged damage which occurs constitutes a serious strength problem. In addition, the inlet opening and thus the flow through the cooling bore change. For this reason, the trepanning method for cooling holes having a diffuser can only be used in the case of small wall thicknesses.
Publication U.S. Pat. No. 5,609,779 discloses a method of forming an opening in a metallic component wall, the opening having a widening diffuser. The noncircular diffuser is produced by an Nd:YAG laser beam being directed within a few laser pulses in an accelerated manner from the center line of the opening to the edge of the diffuser. The pulse rate and the power of the laser are selected in such a way that the metal is vaporized by the laser beam. A disadvantage is that the diffusers which are produced turn out to be very variable with such a method. However, uniform effectiveness of the cooling openings is imperative in modern gas turbines on account of the close dimensioning of the components.
SUMMARY OF THE INVENTION
Accordingly, one object of the invention is to provide a novel method with which a cooling bore can be formed in a wall in a cost-effective, accurate and highly flexible manner. In particular, the method is to permit the cooling bore to be formed irrespective of the production tolerances of the wall thickness and is to be suitable for all wall thicknesses. Furthermore, a cooling bore which can be produced in a cost-effective and flexible manner is to be provided. This object is achieved by the method of forming a cooling bore as claimed in claim 1 and the noncircular cooling bore as claimed in claim 13 .
The method according to the invention for forming a cooling bore in a wall of a workpiece, the cooling bore, in the flow sequence, having a feed section of constant cross-sectional area and a diffuser section widening toward an outlet at an outer surface of the wall, comprises the following steps:
A) selecting the shape and size of the cross-sectional area and an axis of the feed section; B) selecting the depth of the diffuser section and the shape and size of its discharge area at the outlet; C) producing a throughbore having a cross-sectional area which lies within the cross-sectional area, selected in step A, of the feed section; and D) cutting out the diffuser section with a beam- or jet-drilling method, the drilling beam or jet being directed in such a way that, in the region of the feed section, it remains essentially within the cross-sectional area selected in step A.
The invention is accordingly based on the idea of cutting out the diffuser section of a cooling bore with a drilling beam or jet in such a way that the feed section is not damaged or is only slightly damaged, as a result of which the cooling bore obtains high strength.
The flow of the cooling medium through the cooling bore during operation establishes a direction of flow in the cooling bore. The shape and size of the cross-sectional area of the feed section determine the quantity of cooling medium flowing through. The method according to the invention offers the advantage that the cooling bore can be cut in an accurate and flexible manner by the use of a drilling-beam or drilling-jet method, in particular a laser-drilling method. The method is suitable for uncoated components as well as for metallically or ceramically coated components. In the latter case, the cooling bores can be produced after the coating in a single operation. It is not necessary to drill the holes before the coating and to expose the obstructed openings again after the coating. Damage to the feed section is minimized owing to the fact that the drilling beam or jet remains essentially within the cross-sectional area of the feed section when cutting out the diffuser section.
The beam- or jet-drilling method used is preferably a laser-drilling method, in particular a pulsed laser-drilling method. In this case, a pulsed Nd:YAG laser or a pulsed CO 2 laser is preferably used. However, the use of other drilling beams or jets, for instance a water jet, is also within the scope of the invention.
The diffuser section is preferably cut straight in step D, so that the boundary surfaces of the diffuser section have no curvature in the direction of flow of the cooling bore. The strength of the cooling bore can be further increased by the feed section being cut out to the final contour in a further step E. Such a step increases the quality of the feed section and thereby contributes to the quality and strength of the entire cooling bore.
For the feed section, an elliptical, in particular circular, cross section is preferably selected in step A. The cross section of the feed section is at the same time taken perpendicularly to the axis of the cooling bore.
The axis of the feed section intersects the outer surface advantageously at an angle α<90° and thereby defines the direction of tilt of the cooling bore. The film-cooling effectiveness of the cooling bore can be increased by the discharge area of the diffuser section being selected in such a way that the diffuser section widens toward the outer surface of the wall at least in the direction of tilt of the axis. That boundary surface of the diffuser section which lies in the opposite direction to the direction of tilt is advantageously rounded off toward the axis, in particular elliptically. As a result, the stability of the cooling bore in the face of external effects increases on the one hand, and on the other hand the rounding-off leads to a further significant reduction in the damage to the feed section when cutting out the diffuser part.
That outlet edge of the diffuser section which lies in the direction of tilt is expediently selected in such a way that it is essentially straight and merges at its ends in a smooth curve into the side edges of the outlet. It is especially expedient to select a circular cross section of radius R for the feed section, and to select that outlet edge of the diffuser section which lies in the direction of tilt in such a way that it merges into the side edges of the outlet with a radius of curvature greater than R.
A further increase in the cooling effectiveness can be achieved if the discharge area of the diffuser section is selected in such a way that the diffuser section widens laterally toward the outer surface of the wall.
The outer surface of the wall, before the throughbore is produced in step C, is advantageously covered at least partly with a protective coating, in particular a ceramic protective coating.
The noncircular cooling bore according to the invention in a wall of a workpiece comprises a feed section of constant cross-sectional area and a diffuser section, which widens toward an outlet at a first surface of the wall. In this case, the feed section comprises an entry section, which emerges at a second surface of the wall, and a delivery section adjoining the diffuser section, the length of the entry section at the axis being at most 40% of the length of the feed section. Furthermore, the boundary surfaces of the diffuser section are straight in the direction of flow of the cooling bore, and the tangents to the boundary surfaces through the axis run in the interior of the delivery section and intersect the feed section at most in the entry section.
Such a noncircular cooling bore, on account of its design, can easily be produced by a laser-drilling method. The relative sizes of the entry section and the delivery section ensure that the feed section is not damaged too severely by the laser beam. The condition at the tangents to the boundary surfaces ensures that, if the beam is suitably directed, a straight laser beam, when cutting out the diffuser, damages the feed section at most in the region of the entry section, but otherwise passes through the opening in the second surface without affecting part of the component wall.
The axis of the cooling bore expediently intersects the first surface of the wall at an angle of between 10° and 60°, preferably at an angle of between 15° and 50°, especially preferably at an angle of between 25° and 35°. The cooling effectiveness of the cooling bore can be further increased if the diffuser section widens toward the first surface of the wall at least in the direction of tilt of the axis or if the diffuser section widens laterally toward the first surface of the wall. The effectiveness can be increased to an especially marked degree if lateral widening and downstream widening are combined.
That boundary surface of the diffuser section which lies in the opposite direction to the direction of tilt is rounded toward the axis, preferably elliptically. As a result, the stability of the cooling bore in the face of external effects increases on the one hand, and on the other hand the rounding-off leads to a further significant reduction in the damage to the feed section when cutting out the diffuser part. That boundary surface of the diffuser section which lies in the direction of tilt is preferably essentially flat and merges in a smooth curve into the side surfaces.
The feed section preferably has a circular cross section of radius R. The length of the feed section is then expediently selected in such a way that it is at least 2R at its shortest boundary surface. A well-defined cylindrical opening region, which determines the cooling-medium quantity flowing in during operation, is thereby established.
In a development of the invention, the first surface of the wall is covered at least partly with a protective coating, in particular a ceramic protective coating. In a further development of the invention, the wall is the outer wall of a hollow-profile body, in particular of a gas-turbine blade.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 shows a cross section through a wall with a cooling bore according to the invention;
FIG. 2 shows a partial view of the wall in direction 2 — 2 of FIG. 1;
FIG. 3 shows a perspective view of a cooling bore according to the invention;
FIG. 4 shows a schematic representation which illustrates the cutting-out of a cooling bore with a laser beam corresponding to an exemplary embodiment of the invention;
FIG. 5 shows a bottom view of a wall in direction 5 — 5 of FIG. 1;
FIG. 6 shows a perspective partial side view of the wall of FIG. 5 .
Only the elements essential for the understanding of the invention are shown. Not shown, for example, are the complete hollow-profile body of the turbine blade and the entire arrangement of the cooling bores. The direction of flow of the working medium is designated by arrows.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, an exemplary embodiment of the invention is explained with reference to the cooling bore shown in FIGS. 1 to 3 . The cooling bore 20 in a wall 10 extends from an inner surface 14 to an outer surface 12 . A hot-gas flow flows along the outer surface 12 in the operative environment of the wall 10 . The inner surface 14 is the boundary surface of a cooling-medium chamber, which contains pressurized cooling air on the cooling-chamber side, the cooling bore 20 has a cylindrical feed section 22 , whose cross section at the inlet 34 determines the cooling-air quantity flowing through. The diffuser section 24 widens from the feed section 22 toward the outlet 32 at the outer surface 12 . As can best be seen in FIG. 2, the widening is effected not only laterally but also downstream. FIG. 3 shows a perspective view of the cooling bore 20 .
The component to be provided with cooling bores has a nominal wall thickness S nom . As indicated schematically in FIG. 1, a wall thickness of between S min (designation 14 a ) and S max (designation 14 b ) is permitted when producing the wall; the actual wall thickness S (designation 14 ) is therefore between S min and S max .
The feed section 22 , perpendicularly to its axis 30 , has a circular cross section of diameter d. The length l of the feed section 22 is selected in such a way that, at the minimum wall thickness S min , it still corresponds to its diameter, that is, it is at least d. If the wall thickness is greater than S min , the feed section becomes correspondingly longer. Due to the variation in the wall thickness, the feed section 22 thus changes, but not the diffuser section 24 . This design ensures a well defined cooling-air opening irrespective of the production tolerances at each wall thickness.
The boundary surfaces 40 - 46 of the diffuser section 24 have no curvature in the direction of flow of the cooling medium, that is, along the axis 30 . It is thereby possible to cut out these surfaces by a straight laser beam from the outer surface 12 (FIG. 4 ). As can be seen in FIGS. 2 and 3, however, the boundary surfaces have pronounced rounded-off portions perpendicularly to the axis 30 . In this embodiment, the upstream boundary surface is rounded elliptically toward the axis 30 . It merges in a smooth curve into the side surfaces 44 , 46 . The downstream boundary surface 42 of the diffuser is essentially flat and, with a radius of curvature R 2 , merges smoothly into the side surfaces 44 , 46 . In this case, R 2 is selected to be larger than the radius of the cylindrical section R=d/2. In the exemplary embodiment, R 2 is 50% larger than the radius of the cylindrical section 22 .
The result of these measures is that the tangents 50 to the boundary surfaces 40 - 46 through the axis 30 intersect the cylindrical feed section at most in a small entry section 28 . The delivery section 26 is not affected by the tangents. Such a cooling bore can therefore be cut out very effectively by a laser beam, since the laser beam, like the tangents 50 , damages the feed section 22 at most in the entry section 28 during the cutting-out. The laser beam generally passes through the opening 34 of the feed section without causing damage.
A production method according to the invention for a cooling bore as shown in FIGS. 1 to 3 is described below:
the configuration of the hole is established in a first step. The nominal wall thickness and permitted tolerance of the wall thickness are included in the process. The diameter of the cylindrical feed section, its minimum length measured at its downstream edge, and the angle which the hole axis includes with the outer surface are established. At the diffuser section, the shape and size of the discharge area is established, in particular the radius of the elliptical rounded-off portion at the upstream side and the radii of curvature with which the downstream edge merges into the side surfaces. The depth of the diffuser section results from the minimum wall thickness S min permitted and the minimum length of the cylindrical section.
These values are established for the different nominal wall thicknesses in such a way that the aerodynamic parameters of the cooling bores and thus the cooling effectiveness do not change. This is done by virtue of the fact that the opening ratio A r , the mean hole width Z m and the covering Z m /P are kept constant. Here, the opening ratio A r is the ratio of the diffuser discharge area A out to the cylindrical inlet area A in , measured in each case perpendicularly to the hole axis. The covering results as a ratio of the mean hole width Z m to the spacing of the cooling bores P.
In a next step, a throughhole, which has a somewhat smaller diameter than the cylindrical feed section, is drilled in the wall. The diffuser section is then cut out with the laser beam at a cutting speed adapted to the respective drilling depth (FIG. 4 ). In the process, the laser beam 60 is focused with a lense 62 and directed (designation 64 ) along the contour to be cut out. Finally, the cylindrical section is cut out to the final contour. The laser beam is controlled via a CAD/CAM interface with a conventional CNC machine.
The method described may be used both for uncoated and for metallically or ceramically coated component walls.
FIG. 5, in a bottom view, shows the cooling-chamber-side inlet 34 of a cooling bore 20 . The regions 52 at the margin of the opening 34 have been additionally cut out by the laser-drilling process. These regions are kept small due to the configuration according to the invention of the diffuser section.
The bottom region of a cooling bore is shown in perspective side view in FIG. 6 . The lines designated by designations 14 a (S min ) and 14 b (S max ) indicate the region of the positions of the inner surface which are possible due to the permissible tolerance of the wall thickness. At a wall thickness of S max , the damaged region 52 is greatest. At a wall thickness S min , no damage occurs. FIG. 6 shows that it is advantageous for reasons of cost to tolerate a certain degree of damage, since the permissible wall-thickness tolerance becomes very small if the feed section is required to be completely free of damage.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
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In a method of forming a cooling bore in a wall of a workpiece, the configuration of a feed section and a diffuser section is selected, a throughbore is produced with a cross-sectional area within the cross-sectional area of the feed section, and the diffuser section is cut out by a beam- or jet-drilling method in such a way that the drilling beam or jet in the region of the feed section remains essentially within the cross-sectional area of the latter.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a system and a method for emitting an audio signal in an environment. More specifically the invention relates to a system for emitting an audio signal in an environment, the system comprising: an audio source for providing the audio signal, at least one loudspeaker for emitting the audio signal, and at least one microphone for receiving an acoustic signal from the environment, whereby the acoustic signal is based on the audio signal and may comprise disturbing components. The invention also relates to a method using the system.
[0002] Public address systems or other systems for emitting audio signals, like music, speech or announcements, in different locations like supermarkets, schools, universities, auditoriums are widely known. These systems usually comprise an audio source, for example a microphone or a recorder, and a plurality of loudspeakers, which are locally distributed in the locations, for emitting the audio signal from the audio source.
[0003] In simple embodiments, these systems have an adjustable amplification, so that the volume of the audio signal emitted by the loudspeakers can be adjusted to a desired value. In more sophisticated systems, the amplification is made dependent from the noise and other disturbing components in the locations. In some of these systems a signal to noise ratio (SNR) is calculated, which is often determined as the quotient: (amplified output)/(sensed ambient signal-amplified output), whereby the sensed ambient signal may be detected by a microphone in the locations. Such an approach is for example disclosed in the document U.S. Pat. No. 5,434,922 A in the connection of a radio for an automobile.
[0004] Document EP 1 808 853 A 1, probably representing the closest prior art, discloses a public address system which compares a wanted audio signal with a disturbing audio signal and calculates an amplification factor for amplifying the audio signal.
SUMMARY OF THE INVENTION
[0005] According to the invention a system for emitting an audio signal in an environment, especially in an acoustic environment is disclosed. The system may be realized as a small-scaled, for example handheld system like a mobile phone, a personal digital assistant (pda) a tablet-computer etc. It may be realized as a mid-scaled or private system like a car or home stereo, television set etc. Preferably the system is a large-scaled or public system like a public address system etc.
[0006] Accordingly, the environment may—for example—be the adjacent or close-by surrounding area for the small-scaled system, a room or the interior space of a vehicle for the mid-scaled system. In case of the large-scaled system it is also possible that the system provides the audio signal for a conference room or conference hall as the environment or for a plurality of rooms as a plurality of environments.
[0007] The audio signal is preferably realized as an information carrying signal addressed to persons staying in the environment or using the environment. The information carried by the audio signal is especially a spoken information and is for example embodied as an announcement, a message or as a speech. In another embodiment of the invention the information carried by the audio signal is music or a combination of music and spoken information.
[0008] The audio source may be realized as an audio signal generating unit, for example a microphone, especially a transducer, or as an audio signal reproducing unit, for example a recorder or a computer, which outputs computer spoken audio signals. Optionally the audio source is coupled to an amplifier and/or a damping unit for amplifying or damping the audio signal.
[0009] The system further comprises at least one loudspeaker, which emits the audio signal in the environment. In case of the small-scaled systems, only one loudspeaker or loudspeaker arrangement may be present, in case of the midscaled systems, a plurality of loudspeaker may be distributed in the room or interior space. In case of the large-scaled systems, at least one loudspeaker is arranged in each room, which is provided by the system with the audio signal, so that the system may comprise a plurality of loudspeakers, which are locally distributed.
[0010] At least one microphone is provided for receiving an acoustic signal from the environment. The microphone may be realized as any kind of a transducer, which converts the acoustic signal in an electric signal. The acoustic signal is based on the audio signal, especially comprises the audio signal or at least parts or fragments of the audio signal. Disturbing components of the acoustic signal are based on echoes, transmission errors, reverberations and/or noise in the environment or are resulting from the system itself.
[0011] According to the invention, the system comprises an analyzing module, which is adapted or operable to analyze the acoustic signal. During the analyzing step, an objective intelligibility measure is performed, as a result from the analyzing step or from the objective intelligibility measure method an intelligibility measure is derived or calculated or estimated. The intelligibility measure is defined as a characteristic of how comprehendible the information, especially the speech or announcement, inserted by the audio signal in the acoustic signal is.
[0012] The intelligibility measure is preferably a value, especially a time dependent value or a plurality of values, for example a vector or matrix of values, especially a plurality of time dependent values. A plurality of values is for example advantageous in case a plurality of different environments, for example rooms, shall be controlled independently or separately from each other, so that for each environment one value is provided. It is also possible that the intelligibility measure is frequency dependent, so that a plurality of values is provided for one acoustic signal from one location, whereby the plurality of intelligibility values refer to different frequencies or different frequency bands of the acoustic signal.
[0013] The intelligibility measure may for example be derived by one of the following objective intelligibility measure methods:
AI Artificial Index,
[0014] Sll Speech-Intelligibility index (ANSI S3.5-1997)
STI Speech transmission Index
SSR Segmental SNR
LLR Log-Likelihood Ratio
[0015] IS ltakura-Saito
CEP Cepstral Distance Measure
WSS Weighted-Spectral Slope Metric
FWS Normalized Frequency Weighted SSNR
PESQ PESQ
[0016] DAU Dau auditory model
CSII Coherence Sll
[0017] CSTI Covariance based STI
STOI Short-time Objective Intelligibility Measure
[0018] References for the above-mentioned objective intelligibility measure methods can be found in the scientific paper from Cees Taal, Richard Hendriks, Richard Heusdens, Jesper Jensen: Intelligibility Prediction of Single-Channel NoiseReduced Speech; in ITG-Fachtagung Sprachkommunikation • Oct. 6-8, 2010 in Bochum, Germany (ISBN 978-3-8007-3300-2), which is incorporated by reference in its entirety.
[0019] The intelligibility measure is used as a feedback signal in the system. As explained in the following, the feedback signal may for example be coupled back to the system in order to improve or control the intelligibility of the acoustic signal or to protocol the intelligibility measure for example as a proof or a look-up table or to start other reactions of the systems like repeating the audio signal in order to improve the intelligibility. Additionally or alternatively the feedback signal may be coupled back in an indicating unit of the system, indicating a call operator or a speaker that the audio signal was emitted for example with a bad intelligibility.
[0020] The system according to the invention shows various advantages: The setup of the system is easy, because a setting of the desired intelligibility measure or range is almost sufficient. The intelligibility measure as a feedback signal is an expressive value and a direct measure for the performance of the system, because it is in general the main goal of a system for emitting an audio signal in an environment that the audio signal is intelligible and not for example whether or not the signal to noise ratio is kept at a certain level.
[0021] In a preferred embodiment of the invention, the analyzing module or the system itself works in real-time, so that the feedback signal is also coupled back in real-time. Real-time in the connection of the system means that the intelligibility measure is provided with a small delay for example smaller than 2 s, preferably smaller than 1 s and especially smaller than 0.5 s. This embodiment has the advantage, that a reaction of the system or of the call operator or of the speaker can also be provided promptly or also in real-time. This embodiment is the basis for example for a system, which adapts the audio signal in real-time in dependence from the intelligibility measure.
[0022] The main application of the system can be found in the transmission of spoken information, like an announcement, a message or a speech etc. Therefore it is preferred that the intelligibility measure is a measure for the speech intelligibility of the acoustic signal. Various possibilities for deriving the intelligibility measure, especially the speech intelligibility measure, are listed above. In alternative embodiments, the system can provide a intelligibility measure for music, so that the system cares about the intelligibility of music, for example in a concert hall or in a car.
[0023] In a preferred embodiment of the invention, the analyzing module is operable to compare the audio signal as a clean signal with the acoustic signal as a noisy signal to derive the intelligibility measure of the acoustic signal. In order to improve the result, it is preferred that the two signals are time-aligned prior to the comparison.
[0024] In a practical realization, the objective intelligibility measure is based on the STOI—Short-time Objective Intelligibility Measure as disclosed for example in the scientific paper Cees H. Taal, Richard C. Hendriks, Richard Heusdens, Jesper Jensen: a short-time objective intelligibility measure for time-frequency weighted noisy speech; in International Conference on Acoustics Speech and Signal Processing (ICASSP), 2010 IEEE, ISBN: 978-1-4244-4295-9, which is incorporated by reference in its entirety. Especially, the objective intelligibility measure is based on the comparison of the frequency distribution of the time aligned audio signal and the acoustic signal during a short time period, for example shorter than 1 s, especially shorter than 0.5 s.
[0025] In a preferred embodiment, the system comprises an automatic volume control with a control loop, which is adapted to control the volume (or energy) of the audio signal emitted by the at least one loudspeaker, whereby the intelligibility measure is used as the feedback signal in the control loop. In this embodiment a intelligibility measure based automatic volume control is proposed. The volume may be controlled by using a gain or an amplification factor of an amplifier as an actuating variable. The control loop may for example be realized as a closed-loop control, but also other control strategies like fuzzy logic etc. are possible. The advantage of this embodiment is, that the system will keep the intelligibility, especially the speech intelligibility of the acoustic signal according to a predefined set-point or range, and thus secures that all acoustic signals are intelligible. Especially in case of using the analyzing module in a real-time mode, the system can react instantaneously on for example rises of the background noise, without destabilizing the system.
[0026] In a development of the invention, the analyzing module is operable to provide the intelligibility measure for at least two or a plurality of frequency bands of the acoustic signal, whereby for each of the frequency bands an intelligibility value is calculated. Furthermore the automatic volume control uses the at least two intelligibility values for controlling the volumes of the frequency bands of the audio signal separately and/or independently from each other. This development allows the system to adapt the volume in different frequency bands separately in order to compensate for noise sources in certain frequency ranges.
[0027] In a possible realization of this development, the automatic volume control is adapted to keep the overall energy or volume in the environment of the emitted audio signal constant or within a pre-defined range. In this realization, the system allows to keep the overall energy or volume constant while maintaining a pre-defined intelligibility. For example in case the intelligibility of a first frequency band is high and the intelligibility of a second frequency band is low, the volume of the first frequency band is reduced and the volume of the second frequency band is increased, so that the intelligibility of all frequency bands is sufficient or a above a pre-defined level and the overall volume is kept constant or at least kept within desired or pre-defined ranges.
[0028] In a further preferred embodiment, the system comprises a repeating module, which is adapted to repeat the same audio signal or another, substituting audio signal in case the intelligibility measure is worse than a pre-defined value or threshold. In this case the feedback signal is used as a basis for a decision whether or not the audio signal must be emitted a further time.
[0029] In yet a further possible embodiment, the system may comprise a protocol module, which is operable to protocol the intelligibility measure of the acoustic signal. In this embodiment the feedback signal is used to protocol whether or not the audio/acoustic signal was intelligible for the persons in the environment. The protocol derived from the protocol module may hold meta-data about the audio signal, time of broadcasting or emission of the audio signal, the location of the broadcasting or emission of the audio signal in the environment and the intelligibility measure. This protocol may for example beneficially be used as a proof or an evidence that a certain audio signal was intelligibly emitted in a certain area.
[0030] In yet a further embodiment of the invention, an information module is provided, which is adapted to inform a user of the system of the intelligibility measure or a representative or an equivalent thereof. The information module may for example comprise visual indicators like traffic lights, indicating whether or not a just emitted audio signal was intelligible or not. In case the audio signal was not intelligibly emitted, the user has the possibility to react and—for example—may repeat the audio signal. In case the information module indicates that the audio signal was intelligibly emitted, the user will receive a positive confirmation.
[0031] In a practical realization the system is embodied as a public address system or as a sound reinforcement system comprising a plurality of loudspeakers as described above.
[0032] In a possible embodiment, the system, especially the public address system comprises a speaker unit with a transducer or a microphone and visual indicators indicating whether or not a just emitted audio signal was intelligible or not. A further subject-matter of the invention is a method for controlling, correcting and/or indicating the intelligibility measure of an audio signal generated by the system as described above, whereby the intelligibility measure is used as a feedback signal in the system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Further effects, features and advantages will become apparent by the description of preferred embodiments of the invention and the figures as attached. The figures show:
[0034] FIG. 1 a block diagram of a system for emitting an audio signal in an environment as an embodiment of the invention;
[0035] FIG. 2 a block diagram of the control module of the system in FIG. 1 ;
[0036] FIG. 3 a block diagram of the control module of FIG. 2 in another embodiment.
DETAILED DESCRIPTION
[0037] FIG. 1 is a block diagram illustrating a system 1 for emitting an amplified audio signal 2 in an environment 3 . The system 1 comprises at least one loudspeaker 4 for emitting the amplified audio signal 2 into the acoustic environment 3 and at least one microphone 5 for receiving an acoustic signal 6 from said acoustic environment 3 . The acoustic signal 6 comprises parts of the emitted audio signal 2 and furthermore disturbing components from the environment 3 like echo reverberations and additionally noise 7 , which may result from the environment 3 or from the system 1 itself like amplifier noise etc. The system 1 further comprises or is coupled to audio signal generating means (not shown) for example a recorder or a microphone for a speaker, which generate the un-amplified or original audio signal 8 . The audio signal 8 is amplified by an amplifier 9 .
[0038] In this embodiment, the system 1 is realized as a public address system or a sound reinforcement system, which could comprise a plurality of loudspeakers 4 and also a plurality of microphones 5 . Such an public address system can be used in schools, supermarkets or other places, whereby a plurality of acoustic environments 3 are formed in which at least one loudspeaker 4 and one microphone 5 is arranged. Such an acoustic environment 3 may be realized as room, for example a class room.
[0039] As indicated in FIG. 1 , the acoustic signal 6 (converted into an electric signal) is guided into a control module 10 , which will be explained in connection with FIG. 2 . Furthermore the original audio signal 8 is guided into the control module 10 . As an output, the control module 10 comprises a gain signal 11 path to the amplifier 9 , so that the control module 10 is operable to control the gain of the amplifier 9 and thus the volume of the amplified audio signal 2 .
[0040] FIG. 2 illustrates the components of the control module 10 , which shows two inputs for receiving the audio signal 8 and the acoustic signal 6 and one output for sending the gain signal 11 to the amplifier 9 . In a first step, the audio signal 8 is delayed by a delay unit 12 in order to be time-aligned with the acoustic signal 6 . The time delay between the audio signal 8 and the acoustic signal 6 results from different lengths of the signal paths and may be eliminated or compensated as described or by another way. The two signals 6 and 8 are transferred to an analyzing module 13 , which is adapted to analyze the two signals 6 and 8 and to provide an intelligibility measure from an objective intelligibility measure.
[0041] The objective intelligibility measure method used in the analyzing module 13 preferably shows a low complexity with high correlation to the subjective speech intelligibility of the acoustic signal 6 .
Example
[0042] The method proposed as an example is a function of the clean and processed speech, denoted by x and y, respectively, which corresponds to the audio signal 8 and the acoustic signal 6 . The model is designed for a sample-rate of 10000 Hz, in order to cover the relevant frequency range for speech-intelligibility. Any signals at other sample-rates should be re-sampled. Furthermore, it is assumed that the clean and the processed signal are both time-aligned, for example by the delay unit 12 . First, a TF-representation (Time Frequency) is obtained by segmenting both signals into 50% overlapping, Hanning-windowed frames with a length of 256 samples, where each frame is zero-padded up to 512 samples and Fourier transformed. Then, an one-third octave band analysis is performed by grouping OFT-bins. In total 15 one-third octave bands are used, where the lowest center frequency is set equal to 150 Hz. Let {circumflex over (x)} (k,m) denote the k th DFT-bin of the m th frame of the clean speech. The norm of the j th one-third octave band, referred to as a TF-unit, is then defined as,
[0000]
X
j
(
m
)
=
∑
k
=
k
1
(
j
)
k
2
(
j
)
-
1
x
^
(
k
,
m
)
2
[0000] where k1 and k2 denote the one-third octave band edges, which are rounded to the nearest DFT-bin. The TF-representation of the processed speech is obtained similarly, and will be denoted by Yj (m). The intermediate intelligibility measure for one TF-unit, say dj (m), depends on a region of N consecutive TF-units from both Xj (n) and Yj (n), where nEM and M={(m−N+1), (m−N+2), . . . , m−1, m}. First, a local normalization procedure is applied, by scaling all the TF-units from Yj (n) with a factor
[0000] α=(Σ n X j ( n ) 2 /Σ n Y j ( n ) 2 ) u2
[0000] such that its energy equals the clean speech energy, within that TF-region. Then, αYj (n) is clipped in order to lower bound the signal-to-distortion ratio (SDR), which we define as,
[0000]
SDR
j
(
n
)
=
10
log
10
(
X
j
(
n
)
2
(
α
Y
j
(
n
)
-
X
j
(
n
)
)
2
)
[0043] Hence
[0000] Y ′=max(min(α Y,X+ 10 −β/20 X ), X− 10 −β/20 X ),
[0000] where Y′ represents the normalized and clipped TF-unit and β denotes the lower SDR bound. The frame and one-third octave band indices are omitted for notational convenience. The intermediate intelligibility measure is defined as an estimate of the linear correlation coefficient between the clean and modified processed TF-units,
[0000]
d
j
(
m
)
=
∑
n
(
X
j
(
n
)
-
1
N
∑
l
X
j
(
l
)
)
(
Y
j
′
(
n
)
-
1
N
∑
l
Y
j
′
(
l
)
)
∑
n
(
X
j
(
n
)
-
1
N
∑
l
X
j
(
l
)
)
2
∑
n
(
Y
j
′
(
n
)
-
1
N
∑
l
Y
j
′
(
l
)
)
2
[0000] where I E M. Finally, the eventual OIM is simply given by the average of the intermediate intelligibility measure over all bands and frames,
[0000]
d
=
1
JM
∑
j
,
m
d
j
(
m
)
,
[0000] where M represents the total number of frames and J the number of one-third octave bands. Maximum correlation is obtained with β=15 and N=30, which means that the intermediate measure depends on speech information from the last 384 ms. The delay for providing the intelligibility measure is about 400 ms and is thus provided in real-time.
[0044] The OIM as an example of an intelligibility measure or a similar value from another objective intelligibility measure method is transferred to an automatic volume control 14 as a feedback signal, which compares the intelligibility measure to certain thresholds to determine whether the gain of the amplifier 9 has to be increased, decreased or kept constant to maintain a predefined intelligibility measure. The gain is upper- and lower-bounded to certain predetermined levels. The control module 10 or the automatic volume control 14 may detect silences in speech of the audio signal 8 . During short pauses the gain is frozen and during long pauses, after the echo has died out, the noise level is directly detected and this is translated in a suitable gain, for when the system 1 restarts transmitting a message.
[0045] The main advantages, which can be reached with the invention are as follows: Firstly its simplicity, no extensive setup has to be completed on installation, a simple setting of the desired intelligibility or intelligibility range or measure and the initial acoustical delay to the microphone 5 will do. Because the acoustics of the room do not have to be modeled this system 1 is suitable for any space. The computational complexity is also drastically reduced if the right Objective Intelligibility measure method is chosen. This system 1 can react instantaneously on rises in the background noise, without destabilizing the system. But the main advantage is that there is a direct feedback to the system 1 or the call operator on the intelligibility of the conveyed message. If the intelligibility (measure) is low the gain has to be increased. Known systems generally adapt on the measured signal to noise ratio, this is however not always a good measure of the intelligibility of a message. Making sure that the message was intelligible is in general the main goal of a public address system and not whether the signal to noise ratio is kept at a certain level.
[0046] FIG. 3 illustrates a possible modification of the control module 10 in FIG. 2 . In the modification, the intelligibility measure is coupled back into an processing module 15 . The processing module 15 may be provided additionally or alternatively to the automatic volume control 14 .
[0047] In a first embodiment, the processing module 15 is realized as a repeating module, which is adapted to repeat the audio signal 2 in case the intelligibility measure as a feedback signal is worse than a pre-defined value or threshold. This embodiment can be used in case the system 1 provides announcements or messages in the acoustic environment 3 . In case the announcement was not intelligible, the announcement is repeated automatically or another substituting announcement is provided.
[0048] For example the measured intelligibility is analyzed in a number of frames during a message or announcement. If too many consecutive frames, or too many frames on average are classified as being unintelligible or having low intelligibility the repeating module could give of a warning to the system 1 or to the call operator that the message or announcement might not have intelligible to all the listeners and that the message should be repeated.
[0049] In a second embodiment, the processing module 15 is realized as a protocol module, which uses the intelligibility measure as a feedback signal to protocol the intelligibility of the emitted audio signals 8 . In some applications it is important to know whether or not an announcement was intelligible or not. In order to have a proof for the intelligibility, the protocol module provides a journal as it is known for example from facsimile machines.
[0050] In a third embodiment the processing module 15 is realized as an information module, which is adapted to inform a user of the system about the intelligibility or unintelligibility of the acoustic signal. It is for example possible, that the audio signal generating means is a microphone and the information to the user is fed in to an indication lamp, like a traffic light, which is mechanically coupled or adjacent to the microphone, allowing a real-time feedback to the user, whether or not an announcement or speech was intelligible or not.
[0051] It shall be noted that two or all three embodiments may be realized in one system 1 as a further embodiment of the invention.
[0052] In a simple realization of the invention, the intelligibility measure is a value or a scalar. In more sophisticated realizations, the intelligibility measure may be realized as a vector or a multi-dimensional matrix.
[0053] It is for example possible, that a plurality of acoustic environments 3 are controlled or observed, so that the intelligibility measure is a vector, whereby each entry of the vector is allocated to a single acoustic environment 3 . The acoustic environments 3 may refer to separated areas, for example rooms. Alternatively, the acoustic environments 3 may refer to a common area, for example a conference room or hall, whereby the system 1 secures that in any place of the common area the intelligibility is secured.
[0054] It is also possible, that the system 1 adapts the volume in different frequency bands separately to compensate for noise sources in certain frequency ranges separately. In this case the intelligibility measure is a vector, whereby each entry of the vector is allocated to a frequency band of the acoustic signal 6 or the audio signal 8 . Optionally, the general or overall volume or energy level of the acoustic environment is kept lower while maintaining the intelligibility. This alternative could also cater for further increasing the intelligibility if a maximal gain level has been reached in other bands. This could however reduce the naturalness of the played message.
[0055] Furthermore it is possible to use the system 1 for a plurality of acoustic environments 3 , whereby separate frequency bands are separately controlled, so that the intelligibility measure is a matrix.
[0056] Although the invention was illustrated by means of example by a public address system, the invention may also be used in other audio signal emitting systems like mobile phones, car stereos, television sets etc.
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Public address systems or other systems for emitting audio signals, like music, speech or announcements, in different locations like supermarkets, schools, universities, auditoriums are widely known. These systems usually comprise an audio source, for example a microphone or a recorder, and a plurality of loudspeakers, which are locally distributed in the locations, for emitting the audio signal from the audio source. The invention proposes a system ( 1 ) and a method for emitting an audio signal ( 2, 8 ) in an environment ( 3 ), the system ( 1 ) comprising: an audio source for providing the audio signal ( 2, 8 ), at least one loudspeaker ( 4 ) for emitting the audio signal ( 2 ), at least one microphone ( 5 ) for receiving an acoustic signal ( 6 ) from the environment ( 3 ), whereby the acoustic signal ( 6 ) is based on the audio signal ( 2 ) and may comprise disturbing components ( 7 ), and with an analyzing module ( 13 ) for analyzing the acoustic signal ( 6 ) and for providing an intelligibility measure from an objective intelligibility measure method, whereby the intelligibility measure is used as a feedback signal.
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PRIORITY
Benefit is claimed under 35 U.S.C. 119(e) of pending provisional application 61/009,052 filed Dec. 26, 2007.
This invention is in the field of sports equipment and more particularly relating to the game of golf, providing capability of adding a selectable amount of weight inside the shaft of an existing golf club and affixing the weight at a selectable location anywhere within the length of the shaft.
BACKGROUND OF THE INVENTION
In ongoing evolution in the game of golf, along with a shift to lighter weight shafts there has been increased interest in custom-matching golf clubs to individual golfers in recognition of the differences that characterize individual golfers such as height, weight, strength, firmness of grip, path and velocity of swing, etc., and the differences in golf clubs such as total length, total weight, weight distribution considering head weight, shaft weight and grip weight, along with other variables such as shaft stiffness and related resonances. The overall result of these variables determines how a particular club “feels” to that particular golfer.
For club-matching purposes, the golf industry developed a rating known as “swing-weight”, based on balance measurements made on the club about a fulcrum point usually twelve or fourteen inches from the club cap, characterizing the club on a scale of 77 increments with letters A-G followed by numerals 1-10. Industry standards are D0 or D1 for men and C5 to C7 for women. In another rating system, the MOI (moment of inertia: in physics the product of mass and distance from the axis of rotation) is expressed in terms of total club weight and distance from the center of gravity (balance point) to an arbitrary axis of rotation, usually taken at the club cap end, but suggested by the present inventor as more realistic if taken at an outside point, e.g. twelve inches beyond the cap.
Many golfers including pros are not fully satisfied with the existing rating systems and regard them as approximate guidelines at best, so there is an unfulfilled need for after-market accessories that enable even initially “matched” golf clubs to be fine-tuned to more closely match the golfer's individual physique and needs for improved performance.
DISCUSSION OF KNOWN ART
U.S. Pat. No. 6,765,156 B2 to Latiri for a GOLF CLUB SWING WEIGHT BALANCE AND SCALE provides detailed description regarding “swing weight” and its measurement.
U.S. Pat. No. 5,528,927 to Butler et al for a CENTER OF GRAVITY LOCATOR discloses apparatus and method for measuring “center of gravity” of an object such as a golf club head.
U.S. Pat. No. 4,059,270 to Sayers for METHOD FOR CUSTOM FITTING GOLF CLUBS discloses a device utilizing a system of photobeam measurers to detect the speed imparted to a golf ball and the related variables. In describing the method of evaluating and custom-fitting golf clubs to players, this patent sets forth “swing weight” and club length as the two major variable factors relating to optimization of the golf club.
As examples of patents that teach adding mass to the club head the Sayer patent cites U.S. Pat. Nos. 1,306,029, 1,538,312, 2,163,091, 2,750,194 and 3,692,306. A more recent example, U.S. Pat. No. 6,514,154 to Finn discloses a GOLF CLUB HAVING ADJUSTABLE WEIGHTS AND READILY REMOVABLE AND REPLACEABLE SHAFT.
Approaches to after-market weight-balancing golf clubs have included weights, e.g. in the form of a sleeve or lead tape to be attached on the outside of the shaft. As an environmental hazard, lead tape has become unpopular. Since other external approaches are considered unsightly, alternative internal approaches have included inserting a cork or other weight in the bore of the shaft of the club, pushing it in to an estimated best location where it is retained adhesively or by a tight friction fit such that typically it cannot be removed or even shifted upwardly in the shaft. Known golf club weighting approaches have suffered other drawbacks, for example:
(1) unless the weight is made removable, it cannot be replaced to adjust to a lighter value: it can only be increased by adding another weight;
(2) readjustment of the weight location, which is often desired, is impossible with adhesive fastening; with frictional fastening, typically the weight can be pushed further downwardly but cannot be shifted upwardly in the shaft;
(3) a friction plug of relatively rigid material fails to accommodate the variations in the diameter of the tapered shaft bore, typically decreasing from 0.5 inches at the cap end to about 0.3 inches at the head end, thus the available range of location of any single weight plug is inadequate; and
(4) there is a high probability of failure of the weight fastening system, allowing the weight to shift from the desired location under the strong forces applied during the swing stroke and in general handling and transporting of the golf clubs.
Numerous patents and approaches such as these have failed to fully satisfy the unfulfilled need for an after-market device for conveniently and reliably “balancing” the club to match the golfer, i.e. adding a judicious amount of weight at a strategic “sweet spot” selected as optimal along the shaft to match the golfer and enhance the level of performance.
OBJECTS OF THE INVENTION
It is a primary object of the present invention to provide capability of adjusting and setting the balance of any golf club through the addition of a selectable amount of weight inside the shaft in a manner that it can be positioned throughout the length of a tapered shaft bore and secured reliably in place.
It is a further object that after being secured in place, the weight can be released, relocated upward or downward and again secured reliably in place.
SUMMARY OF THE INVENTION
The objects of the invention have been accomplished by a generally cylindrical weight device including at least one expansion element made of sufficiently rubber-like material and dimensioned such that lengthwise compression causes radial expansion to a predetermined diameter range corresponding to at least a major portion of the typical diameter range of golf club shaft bores.
The device includes at least one weight element and one expansion element. Typically the device is configured with three cylindrical shaped elements, each with a central passageway, located co-linearly, i.e. a single weight element located between a lower expansion element and an upper expansion element.
The lower expansion element is configured at its lower end with a threaded bushing that serves as a compression plate engaged by a captive steel machine screw that traverses the passageways. A washer under the screw head forms a compression plate at the upper end.
The device is initially pushed in to place using a special tool with an elongated shaft ending in a hex driver end that engages a hex socket in the head of the machine screw. The tool includes a permanent magnet acting on the screw head so as to retain engagement and to enable the weight device to be pulled upwardly in the golf club shaft.
Initially the device is loaded onto the tool with the screw tightened only enough to create light friction in the upper region of the club shaft above the desired location; then it is pushed down to the desired location and then secured in place there by rotating the screw clockwise to tighten it securely then the tool is removed.
To relocate the device for “fine tuning” or removal, the tool is reinserted and the screw is rotated counter-clockwise to reduce the holding friction sufficiently to remove the device or shift it up or down as required to a new location where it is again secured as described.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a weight device in a primary embodiment of the present invention.
FIG. 2 is a cross-section of the weight device of FIG. 1 , shown installed in a golf club shaft, shown in part.
FIG. 3 is an elevational view of a manual driver tool for installing, adjusting and removing the weight device of FIG. 1 .
FIG. 4 is a cross section of the tool of FIG. 3 inserted through the cap of a grip showing the driver member on the shaft of FIG. 2 about to engage the weight device of FIG. 1 , shown in part.
FIG. 5 is an elevational view of a secondary embodiment of a weight device of the present invention.
FIG. 6 is a cross-section of the weight device of FIG. 5 installed in golf club shaft, shown in part.
FIG. 7 is a three-dimensional view depicting a first alternative non-magnetic tool and bayonet engagement method for weight device relocation/removal.
FIG. 8 is a three-dimensional view depicting a second alternative non-magnetic tool and bayonet engagement method for weight device relocation/removal.
DETAILED DESCRIPTION
FIG. 1 is an elevational view of a weight device 10 in a primary embodiment of the present invention. A first expansion element 12 of rubber or other elastic material, a weight element 14 and a second expansion element 16 similar to element 12 , are held together in a collinear elongated cylindrical assembly, as shown, by a machine screw 18 traversing central openings in the three elements and a washer 20 under the head of machine screw 18 .
FIG. 2 is a cross-section of the weight device 10 of FIG. 1 , shown installed in a golf club shaft 22 , shown in part. Screw 18 , engaging a threaded bushing 16 A at the lower end, has been tightened sufficiently to expand the diameter of both expansion elements 12 and 16 so as to bear firmly against the inside surface of shaft 22 , securing weight device 10 in place. The golf club shaft 22 is typically made with a bore that tapers from about 2″ in diameter at the top cap end to about ⅜″ at the lower end. To accommodate this variation, a standard version of weight device 10 , for the major upper portion of the shaft 22 , is made with the weight element 14 and the (unexpanded) expansion elements 12 and 16 typically ⅜″ in diameter, and a scaled-down version for a minor lower portion of the shaft 22 , is made with these elements typically ¼″ in diameter.
The weight device 10 is made to have, a designated total weight by the length of the weight element 14 and the density of its material, e.g. brass for high density. It is supported in a firm but resilient manner that prevents any metal-to-metal contact with shaft 22 , as deemed optimal for performance characteristics. At the lower end of screw 18 the threads at the extreme lower end of the threaded portion are crimped so as to keep screw 18 captive and avoid unintended disassembly of weight device 10 during removal or repositioning. In the standard version of weight device 10 , the weight element 14 and the expansion elements 12 and 16 are 3/16″ in diameter.
FIG. 3 is an elevational view of a driver tool 24 for installing, adjusting and removing the weight device 10 of FIGS. 1 and 2 . A metal rod shaft 26 , made approximately the length of a golf club bore, has a blade handle 28 attached at the top end for manual rotation. At the lower end, a hex driver member 30 extends downwardly from a cylindrical permanent magnet 32 attached immediately above.
FIG. 4 is a cross-section of shaft 22 equipped with a golf hand grip 34 , and with a weight device 10 ( FIG. 2 ), shown in part, and a tool 24 ( FIG. 3 ) having been inserted through a circular opening 34 A that has been cut in cap portion 34 A of grip 34 . Opening 34 A has a diameter equal or near that of the inside of shaft 22 at its top end. At the bottom end of tool 24 , an Allen hex driver member 30 is in position immediately above the corresponding hex head of machine screw 18 ready for engagement. Magnet 32 is magnetized in a manner to magnetically attract the (steel) head of machine screw 18 when nearby, and to abruptly force closure of the air gap to fully engage the hex driver member 30 in the head of screw 18 . The weight device 10 can then be relocated or withdrawn by first rotating screw 18 counter-clockwise to reduce the axial pressure and partially relax the expansion elements 12 and 16 to release their grip on shaft 22 to an optimally low amount of residual friction to facilitate relocation or withdrawal. For upward relocation or withdrawal, magnet 32 provides the transmission of the necessary amount of tensile pulling force.
FIG. 5 is an elevational view of a secondary embodiment of a weight device 10 A of the present invention that has fewer parts and that may serve as an added auxiliary mass that can be located near the primary weight device or elsewhere. A relatively short weight element 14 A is located directly under the head of bolt 18 A, and the single compression element 12 is fitted at the lower end with a threaded “T-nut” 36 , as an alternative to bushing 16 A ( FIG. 2 ).
FIG. 6 is a cross-section of the second embodiment weight device of FIG. 5 installed in golf club shaft 22 , shown in part. T-nut 36 , forming a threaded bottom end plate, is a commercial hardware product that is available with a set of spurs that extend upwardly into the expansion element 12 as indicated, for anti-rotation purposes. Insertion, relocation and removal for this second embodiment weight device are as previously described for the primary embodiment weight device 10 . While the dual expansion element mounting of the primary embodiment is inherently extremely robust with a weight element of practically any desired length, with the secondary embodiment having only the single expansion element, the weight element should be kept relatively short in length and possibly tapered to a smaller diameter at the upper end to prevent possibility of contact with the shaft in the event of off-axis displacement if the expansion element is not adequately secured in place. Possibility of such contact can be avoided by shortening of the weight element 14 A to the extreme of making it simply a metal washer of designated thickness, or a stack of several washers; the expansion element 12 may be lengthened for weight increase.
FIG. 7 is a three-dimensional view depicting a first alternative tool 26 A and a corresponding bayonet engagement method for weight device relocation/removal that eliminates the need for a magnet on the tool. In this example, washer 14 B forms a weight element and end plate for expansion member 12 , shown in part. Screw head 18 B is fitted with one of more extending bayonet pins 18 C: in this example a single pin 18 C traversing the head 18 B extends outwardly as two diametrically opposed pins. Tool 26 A may be a hollow tube or may be a solid shaft fitted at the bottom end with a hollow sleeve: near the bottom end tool 26 A is configured with one or more specially shaped T slots 26 B as shown, one for each bayonet pin 18 C on head 18 B.
FIG. 8 is a three-dimensional view depicting a second alternative non-magnetic tool utilizing a bayonet engagement method for weight device relocation/removal. In this example the tool 26 C may be a solid rod with the lower end preferably in the bullet shape shown and fitted with a pair of bayonet pins 26 D. A sleeve 18 D fastened to the bolt head of the weight device is configured with a pair of T slots as shown.
The configurations of FIGS. 7 and 8 are essentially inversions of each other, and function in a similar manner. When engaged with pins located at one or other end region of the T slots, the tool can rotate the screw head clockwise or counter-clockwise, and can pull the weight device upwardly for relocation or removal. For release of tool from the screw head, a slight rotation of the tool relocates the bayonet pins centrally in the T slots in line with the slot entrance. In either version, alternatively, a single short pin could be utilized, or a set of two, three or more short pins could be arranged in a polar array and secured in place in drilled holes. Alternatively the slots could be L-shaped, in the manner of well known auto lamp sockets.
To provide a range of weight that can be added to a golf club, the weight devices may be made available in selected steps; e.g. three basic weights: 50, 25 and 12.5 grams enable the weight to be set to any desired value from 12½ grams in steps of 12½ grams. The 50 gram weight device can be made in the primary embodiment using a brass weight element ⅜″ by about 4″ long. Weighting can be performed with one, two or more weight devices; they can be located together or located independently anywhere along the shaft. The 12.5 gram weight device, and even a 6¼ gram “fine tuner”, may be made either in the primary embodiment, possibly utilizing a plastic weight element, and/or made in the secondary embodiment.
A single weight device may be located anywhere along the shaft length, and with more than one weight device there is full flexibility of locating the devices close together or elsewhere throughout the shaft length.
As an alternative to utilizing a magnet for pulling the weight element to move it upwardly, a mechanical system could utilize a bayonet pin/slot type engagement, generally similar to that found on bayonet base electric lamps, particularly automotive lamps. The L shaped slots could be oriented opposite their normal direction, so that the fastening would tend to stay engaged for pulling purposes while urging the tool counter-clockwise.
The invention may be embodied and practiced in other specific forms without departing from the spirit and essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention encompassing all variations, substitutions, and changes that come within the meaning and range of equivalency of the claims therefore are intended to be embraced therein.
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A weight device for golf clubs can be secured at a selected location within the shaft. A cylindrical weight element is typically disposed between two expansion elements, all three elements being traversed by a machine screw that engages a threaded lower end plate. The screw head is made to be engaged and driven by a special elongated tool to put the device in a sliding-friction mode for moving to any desired location within a golf club shaft, where the device can be secured in place by rotating the screw clockwise to expand the expansion elements against the shaft bore in a compression-secured mode. A permanent magnet affixed to the tool enables upward relocation or removal of the weight device.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an analog switch circuit for activating a number of analog switches made up of semiconductor switching elements.
2. Description of the Prior Art
Conventional analog switches can roughly be classified into two groups mechanical and semiconductor. The mechanical switches are reed relay switches, while the semiconductor switches are insulated gate field effect transistors (referred to as FETs simply, hereinafter). However, FETs are more suitable for use as an analog switch because no gate current flows through the gate thereof without producing a dc offset.
In the above-mentioned FET analog switch mode up of FETs, when a high speed switching signal is directly applied to the gate of an FET to turn it on, since current changes at high speed between the source and the drain thereof, there exists a problem in that impulse switching noise will be generated whenever the analog switch is turned on or off.
Therefore, where a analog switch circuit turned on or off in response to high-speed switching signals is incorporated in an audio appliance, there arises a problem in that generated switching noise exerts a harmful influence upon the audio appliance and therefore the quality of the audio appliance will be degraded. In addition, in case the generated switching noise level is extraordinarily high, there exists a danger such that a speaker provided for an audio appliance may be damaged.
To overcome the above-mentioned problem, the analog switch circuit is usually configured in such a way that switching signals are not directly applied to the gates of FETs.
FIG. 1 shows an example of prior-art analog switch circuits which can reduce switching noise. This prior-art analog switch circuit includes two analog switches 5 each made up of a pair of parallel-connected P-channel FET (referred to as PFET) and N-channel FET (referred to as NFET) with source and drain terminals of two FETs connected to each other. Further, an integrating circuit 7 composed of a resistor R and a capacitor C is connected to each gate terminal of both the PFET 1 and NFET 3, respectively.
Therefore, each analog switch 5 is turned on or off in response to two switching signals outputted from two integrating circuits 7 on the basis of a control signal applied through the control circuit 9. That is, the analog switches 5 are turned on or off in response to two switching signals having gentle leading and trailing edges, so that the PFET 1 and the NFET 3 are both turned on or off at relatively low switching speed, thus reducing change rate per unit time of drain currents passed through the PFET 1 and NFET 3 whenever these FETs 1 and 3 are turned on or off, in order to suppress the generation of switching noise.
In the above-mentioned prior art analog switch circuit, however, since an integrating circuit is connected to each gate terminal of each FET which configures an analog switch and further the resistance or the capacitance of the integrating circuit each occupies a relatively large area, where the analog switch circuit including integrating circuits is formed into an IC circuit, there exists a problem in that a relatively large area is necessary to form these resistances and capacitors. In particular, in the case of an electronic variable resistor circuit, for instance which requires a great number of analog switches, the above-mentioned problem is serious.
In addition, where a great number of integrating circuits are formed to reduce noise, since there inevitably exist differences in resistance and capacitance between the integrating circuits, and therefore differences in time constant therebetween, another problem will occur such that switching noise generation cannot be prevented perfectly.
SUMMARY OF THE INVENTION
With these problems in mind, therefore, it is the primary object of the present invention to provide an analog switch circuit which can reduce switching noise while enabling an integrated analog switch circuit configuration.
To achieve the above-mentioned object, an analog switch circuit according to the present invention comprises: (a) a plurality of analog switching means for transmitting signals; (b) first integrating means for generating an integrated turn-on switching signal to turn on said analog switching means at relatively low switching speed; (c) second integrating means for generating an integrated turn-off switching signal to turn off said analog switching means at relatively low switching speed; (d) a plurality of switching means connected between said analog switching means and said two integrating means, respectively; and (e) control means for simultaneously activating said first or second integrating means and said switching means in such a way that the integrated turn-on or turn-off switching signal is selectively applied to said analog switching means via said activated switching means to turn or off said analog switching means and for generating a turn-on or turn-off signal to said analog switching means via said switching means to hold said analog switching means already turned on or off in response to the turn-on or -off switching signal.
The feature of the analog switch circuit of the present invention is to selectively supply a first (high-voltage level) switching signal generated from a first integrating circuit and a second (low-voltage level) switching signal generated from a second integrating circuit to a great number of analog switches made up of two, P-type and N-type, semiconductor switching elements via switches controlled by a control circuit. Since only two resistors and capacitors are required for the integrating circuits, it is possible to reduce the area required for the in which integrating circuits and also dispersion in time constant of the integrators.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the analog switch circuit according to the present invention will be more clearly appreciated from the following description of the preferred embodiments of the invention taken in conjunction with the accompanying drawings in which like reference numerals designate the same or similar elements or sections throughout the figures thereof and in which:
FIG. 1 is a circuit diagram showing an example of prior-art analog switch circuits;
FIG. 2 is a circuit diagram showing a first embodiment of the analog switch circuit according to the present invention,
FIG. 3 is a waveform diagram for assistance in explaining switching signals for activating or deactivating the analog switches shown in FIG. 2;
FIG. 4 is a circuit diagram showing a second embodiment of the analog switch circuit according to the present invention; and
FIG. 5 is timing charts for assistance in explaining the operation of the analog switch circuit shown in FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiment of the present invention will be described with reference to the attached drawings. FIG. 2 shows a first embodiment thereof.
The analog switch circuit shown in FIG. 2 comprises two analog switches 5a and 5b each composed of a PFET (P-channel field effect transistor) 1 and NFET (N-channel field effect transistor) 3; two first and second integrated signal generators 11a and 11b for generating two integrated switching signals V 1 and V 2 to turn on or off the PFET 1 and NFET 3; four switches SW1, SW2, SW3 and SW4 for selectively supplying the two integrated switching signals V 1 and V 2 to the PFET 1 and NFET 3 of each analog switch 5a or 5b; and a control circuit 13 for selectively activating the first integrator signal generator 11a, the second integrator signal generator 11b, and four switches SW1 to SW4, respectively.
In the analog switch circuit shown in FIG. 2, the two analog switches 5a and 5b are activated (turned on) or deactivated (turned off) in response to two switching signals V 1 and V 2 generated by the two integrated signal generators 11a and 11b and selectively passed through the four switches SW1 to SW4.
In more detail, each analog switch 5a or 5b is composed of the PFET 1 and the NFET 3, and the source terminal and the drain terminal of these two PFET 1 and NFET 3 are connected to each other. The gate terminal of the NFET 3a of the analog switch 5a is connected to a common contact CO of the first switch SW1; the gate terminal of the PFET 1a of the analog switch 5a is connected to a common contact CO of the second switch SW2; the gate terminal of the NFET 3b of the analog switch 5b is connected to a common contact CO of the third switch SW3; and the gate terminal of the PFET 1b of the analog switch 5b is connected to a common contact CO of the fourth switch SW4.
The first integrated signal generator 11a generates a first switching signal V 1 having a gentle leading edge as shown in FIG. 3 in response to a control signal supplied from the control circuit 13. The second integrated signal generator 11b generates a second switching signal V 2 having a gentle trailing edge also as shown in FIG. 3 in response to a control signal supplied from the control circuit 13.
The first integrated signal V 1 is applied to four contacts c of SW1, SW2, SW3 and SW4, simultaneously. The second integrated signal V 2 is applied to four contacts a of SW1, SW2, SW3 and SW4, simultaneously.
Further, two contacts b of SW1 and SW3 are directly connected to the control circuit 13. Two contacts b of SW2 and SW4 are connected to the control circuit 13 via an inverter 15.
In response to a control signal Sc, the control circuit 13 supplies a trigger signal St to the first and second integrators 11a and 11b and simultaneously two switch selecting signals S S1 and S S2 to the switches SW1 to SW4 to change-over these four switches SW1 to SW4.
In addition the control circuit 13 supplies two voltage signals Sv (whose voltage level is equal to that of the integrated signal V 1 or V 2 ) to the gate terminals of the PFETs 1a and 1b and the NFETs 3a and 3b of the analog switches 5a and 5b via contacts b of these switches SW1 to SW4.
The operation of the analog switch circuit shown in FIG. 2 will be described hereinbelow:
(a) When switches 5a and 5b are both turned on:
When a control signal Sc is applied to the control circuit 13, the control circuit 13 outputs two switch selecting signals S S1 and S S2 to change over the switches SW1 to SW4 in such a way that the common contact CO is connected to c in switches SW1 and SW3 and to a in switches SW2 and SW4, as shown by dashed lines in FIG. 2.
Further, since a trigger signal St is applied from the control circuit 13 to the first and second integrators 11a and 11b, a first switching signal V 1 of a gentle leading edge is applied to the gate terminals of the NFETs 3a and 3b of the analog switches 5a and 5b via switches SW1 and SW3.
Further, a second switching signal V 2 of gentle trailing edge is applied to the gate terminals of the PFETs 1a and 1b of the analog switches 5a and 5b via switches SW2 and SW4.
Therefore, the two analog switches 5a and 5b (PFETs 1a and 1b and NFETs 3a and 3b) are both turned on to transmit signals through the analog switches 5a and 5b.
As described above, once the PFETs 1a and 1b and NFETs 3a and 3b of the analog switches 5a and 5b are turned on, the switches SW1 to SW4 are all changed over in such a way that all the common contacts CO are connected to the contacts b as shown by solid lines in FIG. 2, so that a high-voltage level signal is directly supplied from the control circuit 13 to the gate terminals of the NFETs 3a and 3b and a low-voltage level signal is supplied to those of the PFETs 1a and 1b via inverters 15 in order to keep these two analog switches 5a and 5b already turned on.
(b) When switches 5a and 5b are both turned off:
When a control signal Sc is supplied to the control circuit 13 under the condition that the two analog switches 5a and 5b are on, each common contact CO is connected from b to a in SW1 and SW3 and to c in switches SW2 and SW4.
Further, in the same way as when turned on, since a trigger signal St is applied from the control circuit 13 to the first and second integrated signal generators 11a and 11b, a first switching signal V 1 of a gentle leading edge is applied to the gate terminals of the PFETs 1a and 1b of the analog switches 5a and 5b via switches SW2 and SW4.
Further, a second switching signal V 2 of a gentle trailing edge is supplied to the gate terminals of the NFETs 3a and 3b of the analog switches 5a and 5b via switches SW1 and SW3.
Therefore, the two analog switches 5a and 5b (PFETs 1a and 1b and NFETs 3a and 3b) are both turned off to interrupt signals through the analog switches 5a and 5b.
Once the PFETs 1a and 1b and NFETs 3a and 3b of the analog switches 5a and 5b are turned off, the switches SW1 to SW4 are all changed over in such a way that all the common contacts CO are connected to the contacts b in all the switches SW1 and SW4, so that a low-voltage level signal Sv is directly supplied from the control circuit 13 to the gate terminals of the NFETs 3a and 3b and a high-voltage level signal is supplied to those of the PFETs 1a and 1b via the inverters 15 in order to keep these two analog switches 5a and 5b turned off.
In the above first embodiment, two analog switches 5a and 5b are simultaneously turned on or off. However, it is also possible to switch any one of these two analog switches 5a and 5b, independently. In this case, the common contacts CO of two of four switches SW1 to SW4 connected to the analog switch 5a or 5b to be kept unswitched are kept connected to contacts b.
Further, in the above embodiment, it is of course possible to switch a great number of analog switches simultaneously, without being limited to the number of analog switches.
As described above, in the first embodiment of the present invention, since a number of analog switches can be turned on or off in response to two switching signals V 1 and V 2 generated from only two integrated signal generators 11a and 11b, the number of resistances and capacitors for forming two integrating circuits can be reduced down to two, irrespective of the number of the analog switches, thus enabling a higher density ICed analog switch circuit. Further, since all the analog switches can be activated simultaneously, it is possible to reduce switching noise generated due to mutual interference between two analog switches.
FIG. 4 shows a second embodiment of the present invention, which also includes only two integrating circuits and a number of analog switches so as to be applicable to an electronic variable resistor circuit.
The analog switch circuit shown in FIG. 4 comprises a control circuit 17, an up/down keys 27, an up/down counter 19, two integrating circuits 21a and 21b, a number of detecting circuits 23, a series-connected resistor 25, and a number of analog switches 5.
The control circuit 17 is connected to the up/down counter 19, the detecting circuits 23a to 23e and the integrating circuits 21a and 21b. That is, whenever the up/down key 27 is depressed, a first clock signal CK1 is applied to the up/down counter 19 and the two integrating circuits 21a and 21b; a second clock signal CK2 is applied to the detecting circuits 23a to 23e; and an up/down signal U/D is applied to the up/down counter 19.
Each output terminal Qa to Qe of the up/down counter 19 is connected to each detecting circuit 23a to 23e. When the up key 27 (UP) is depressed, an up signal is applied to the up/down counter 19, so that an output signal for instance is applied from the output terminals Qa to Qe to the detecting circuits 23a to 23e sequentially beginning from the terminal Qa whenever the first clock signal CK1 is given to the up/down counter 19. In contrast with this, when the down key 27 (DN) is depressed, a down signal is applied to the up/down counter 19, so that an output signal is applied from the output terminals Qa to Qe to the detecting circuits 23a to 23e sequentially beginning from the terminal Qe whenever the first clock signal CK1 is given to the up/down counter 19.
Each of the integrating circuits 21a and 21b is made up of a resistor R and a capacitor C. The integrating circuit 21a integrates the first clock signal CK1 and outputs a first switching signal V 1 with a gentle leading edge as shown in FIG. 3 to the detecting circuits 23a to 23e. The integrating circuit 21b integrates an inversion signal of the first clock signal K 1 and outputs a second switching signal V 2 with a gentle trailing edge as shown in FIG. 3 to the detecting circuits 23a to 23e.
A number of detecting circuits 23 control the switching operation of the analog switches 5a to 5e on the basis of the output signal from the up/down counter 19.
Each detecting circuit 23 comprises two D-latch flip-flops 29 and 31 and three two-way switches SW5, SW6, and SW7. The switches SW6 and SW7 selectively supply two output voltages V 1 and V 2 from the integrating circuits 21a and 21b to the PFET 1a and NFET 3a, respectively.
The flip-flop circuit 29 serves to hold a switched status of the analog switch 5a by supplying the two signals from the outputs Q and Q to the gate terminals of the PFET 1a and the NFET 3a via the switch SW5. On the other hand, the flip-flop circuit 31 controls the operations of the switches SW5 to SW7 on the basis of a signal from the output Qa and the first clock signal CK1.
Therefore, when the five analog switches 5a to 5e are turned on in sequence alternately, an input signal applied to the input terminal IN is divided in sequence by a plurality of ladder resistors 25 (connected in series between the input terminal IN and the ground terminal GND) and simultaneously outputted from the output terminal OUT. In more detail, when the analog switch 5a is turned on, the resistance between two terminals IN and OUT is zero; when the analog switch 5a is turned off and the analog switch 5b is turned on, the resistance is Ro; when the analog switches 5a and 5b are turned off and the analog switch 5c is turned on, the resistance is 2Ro; and so on, thus realizing a variable resistor operation in stepped fashion in response to the depression of up key.
The operation of the second embodiment shown in FIG. 4 will be described with reference to timing charts shown in FIG. 5.
(a) When analog switch 5a is turned on:
When the analog switch 5a is kept off, a low-voltage level signal is supplied from the output Q of the flip-flop circuit 29 to the gate terminal of the NFET 3a via the switch SW5, and a high-voltage level signal is supplied from the output Q of the flip-flop circuit 29 to the gate terminal of the PFET 1a via the same switch SW5.
Under these conditions, when a high-voltage level clock signal CK1 and an up signal UP (for allowing the up/down counter 19 to output high-level signals from the output terminals beginning from Qa to Qe sequentially) are given from the control circuit 17 to the up/down counter 19, a high-voltage level signal is outputted from the output terminal Qa of the up/down counter 19 to the flip-flop 31, so that the Q output thereof is latched at a high level and the Q output thereof is latched at a low level. Therefore, the potential at point A changes to a high level via an AND gate to turn off the switch SW5 via a NOR gate and to directly turn on the switch SW6.
In addition, the first clock signal CK1 is given to the integrating circuit 21a and the inverted clock signal thereof is given to the integrating circuit 21b. Therefore, an output voltage signal V 1 as shown in FIG. 5 is outputted from the integrating circuit 21a and an output voltage signal V 2 as shown in FIG. 5 is also outputted from the integrating circuit 21b.
The output voltage V 1 is given to the gate terminal of NFET 3a via the turned-on switch SW6, and the output voltage V 2 is given to the gate terminal of PFET 1a via the same switch SW6, so that the PFET 1a and the NFET 3a are both turned on at a relatively low speed. Under these conditions, an input signal applied to the input terminal IN is directly transmitted from the output terminal OUT through the turned-on analog switch 5a.
Further, immediately after the first clock signal CK1 has changed to a high level, the second clock signal CK2 also changes to a high level and applied to the clock terminal CK of the flip-flop 29, so that the output Q of the flip-flop 29 is switched to a high level and the output Q thereof is switched to a low level.
On the other hand, when the first clock signal CK1 changes to a low level, an inverted high level signal is applied to the clock terminal CK of the flip-flop circuit 31, so that the output Q of the flip-flop circuit 31 changes to a low level and thereby the potential at point A drops to a low level via an AND gate. As a result, the switch SW5 is turned on and the switch SW6 is turned off. A high-level signal is supplied from the output Q of the flip-flop circuit 29 to the gate terminal of the NFET 3a and simultaneously a low-level signal is supplied from the output Q thereof to the gate terminal of the PFET 1a, so that the analog switch 5a is kept turned on as it is.
(b) When analog switch 5a is turned off:
When a high level clock signal CK1 is again applied to the up/down counter 19 under the condition that the analog switch 5a is on, the output Qa of the up/down counter 19 changes to a low level and that Qb thereof changes to a high level. Therefore, the potential at point B changes to a high level, so that the switch SW5 is turned off and the switch SW7 is turned on.
The output voltage V 1 is supplied to the gate terminal of the PFET 1a via the switch SW7 and the output voltage V 2 is supplied to the gate terminal of the NFET 3a via the switch SW7, so that both the PFET 1a and the NFET 3a are turned off at relatively low speed.
Further, immediately after the clock signal CK1 has changed to a high level, when the clock signal CK2 changes to a high level, the output Q of the flip-flop circuit 29 changes to a low level and the output Q thereof changed to a high level.
Thereafter, when the clock signal CK1 changes to a low level, the output Q of the flip-flop circuit 31 changes to a high level, so that the potential at point B changes to a low level.
Therefore, the switch SW5 is turned on via the NOR gate and the switch SW7 is directly turned off, so that a low-level signal is supplied from the output Q of the flip-flop circuit 29 to the gate terminal of the NFET 3a and a high-level signal is supplied from the output Q thereof to the gate terminal of the PFET 1a to turn off the analog switch 5a.
Simultaneously when the analog switch 5a is turned off, the analog switch 5b is turned on. Therefore, an input signal applied to the input terminal N is transmitted from the output terminal OUT through the resistor Ro.
As described above, a number of output signals obtained by sequentially dividing an input signal by the ladder resistors 25 can be outputted from the output terminal OUT, whenever the analog switches are switched on or off in sequence.
In the above second embodiment, five analog switches 5a to 5e are incorporated in the analog switch circuit. However, it is of course possible to increase the number of analog switches without increasing the number (two) of the integrating circuits.
As described above, in the analog switch circuit according to the present invention, a first switching signal having a gentle leading edge generated from the first signal integrating circuit and a second switching signal having a gentle trailing edge generated from the second signal integrating circuit are selectively supplied to a plurality of analog switches for switching operation. Since the numbers of resistors and capacitors can be reduced down to two, it is possible to form the analog switch circuit into an IC. Further, there exist other advantages such that dispersion in time constant of the integrating circuits (due to dispersion in resistor and capacitor values) can be reduced and thus switching noise can further be prevented from being generated.
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In the conventional analog switch circuit, an integrating circuit is connected to each gate terminal of a number of analog switches to reduce the switching speed and thus to reduce switching noise. Therefore, when the analog switch circuit is formed into a single IC chip, an area where resistances and capacitances are to be formed is relatively large. To overcome this problem, only two integrating circuits are provided and two integrated switching signals are selectively applied to gate terminals of the analog switches via switches under control of a control circuit, thus realizing an ICed analog switch circuit, while reducing differences in time constant among the analog switches and thus switching noise.
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FIELD OF THE INVENTION
The present invention relates to electrostatographic developers and toners containing charge-control agents.
CROSS REFERENCE TO RELATED APPLICATIONS
U.S. Ser. No. 08/818,577 pending entitled N-(1,2-BENZISOTHIAZOL-3(2H)-YLIDENEACETYL 1,1-DIOXIDE)AMIDES FOR ELECTROSTATOGRAPHIC TONERS AND DEVELOPERS, filed by inventors of the present case on the same day as the present case.
BACKGROUND OF THE INVENTION
In electrography, image charge patterns are formed on a support and are developed by treatment with an electrographic developer containing marking particles which are attracted to the charge patterns. These particles are called toner particles or, collectively, toner. Two major types of developers, dry and liquid, are employed in the development of the charge patterns.
In electrostatography, the image charge pattern, also referred to as an electrostatic latent image, is formed on an insulative surface of an electrostatographic element by any of a variety of methods. For example, the electrostatic latent image may be formed electrophotographically, by imagewise photo-induced dissipation of the strength of portions of an electrostatic field of uniform strength previously formed on the surface of an electrophotographic element comprising a photoconductive layer and an electrically conductive substrate. Alternatively, the electrostatic latent image may be formed by direct electrical formation of an electrostatic field pattern on a surface of a dielectric material.
One well-known type of electrostatographic developer comprises a dry mixture of toner particles and carrier particles. Developers of this type are employed in cascade and magnetic brush electrostatographic development processes. The toner particles and carrier particles differ triboelectrically, such that during mixing to form the developer, the toner particles acquire a charge of one polarity and the carrier particles acquire a charge of the opposite polarity. The opposite charges cause the toner particles to cling to the carrier particles. During development, the electrostatic forces of the latent image, sometimes in combination with an additional applied field, attract the toner particles. The toner particles are pulled away from the carrier particles and become electrostatically attached, in imagewise relation, to the latent image bearing surface. The resultant toner image can then be fixed, by application of heat or other known methods, depending upon the nature of the toner image and the surface, or can be transferred to another surface and then fixed.
Toner particles often include charge-control agents, which, desirably, provide high uniform net electrical charge to toner particles without reducing the adhesion of the toner to paper or other medium. Many types of positive charge-control agents, materials which impart a positive charge to toner particles in a developer, have been used and are described in the published patent literature. In contrast, few negative charge-control agents, materials which impart a negative charge to toner particles in a developer, are known.
Prior negative charge-control agents have a variety of shortcomings. Many charge-control agents are dark colored and cannot be readily used with pigmented toners, such as cyan, magenta, yellow, red, blue, and green. Some are highly toxic or produce highly toxic by-products. Some are highly sensitive to environmental conditions such as humidity. Some exhibit high throw-off or adverse triboelectric properties in some uses. Use of charge-control agents requires a balancing of shortcomings and desired characteristics to meet a particular situation.
SUMMARY OF THE INVENTION
The invention provides N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)benzenesulfonamides having the general structure: ##STR2## wherein n represents an integer of 1 to 5 and
X represents hydrogen, alkyl, alkoxy, halo, nitro, amino, hydroxyl, carboalkoxy, carboxy, keto, formyl, alkyl sulfonate, sulfonamido, sulfamyl, etc.
Exemplary N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)benzenesulfonamides according to the above structure are N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)benzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-methylbenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-methoxybenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-chlorobenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-nitrobenzesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-aminobenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-hydroxybenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-carbomethoxybenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-carboxybenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-acetylbenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-formylbenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-methoxysulfonylbenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-sulfonamidobenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-sulfamylbenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-3,5-di(t-butyl)-4-hydroxybenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-2,4,6-trimethylbenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-2-nitrobenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-3-chlorobenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-2,4-difluorobenzenesulfonamide, N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-2,3,5,6-tetramethylbenzenesulfonamide, and N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-2,3,4,5,6-pentamethylbenzenesulfonamide.
It is an advantageous effect of the invention that the above compounds are negative charge-control agents for use in electrostatographic toners and developers.
DETAILED DESCRIPTION
The term "particle size" as used herein, or the term "size," or "sized" as employed herein in reference to the term "particles," means the median volume weighted diameter as measured by conventional diameter measuring devices, such as a Coulter Multisizer, sold by Coulter, Inc. of Hialeah, Fla. Median volume weighted diameter is an equivalent weight spherical particle which represents the median for a sample; that is, half of the mass of the sample is composed of smaller particles, and half of the mass of the sample is composed of larger particles than the median volume weighted diameter.
The term "charge-control," as used herein, refers to a propensity of a toner addendum to modify the triboelectric charging properties of the resulting toner.
The term "glass transition temperature" or "T g ", as used herein, means the temperature at which a polymer changes from a glassy state to a rubbery state. This temperature (T g ) can be measured by differential thermal analysis as disclosed in "Techniques and Methods of Polymer Evaluation," Vol. 1, Marcel Dekker, Inc., New York, 1966.
The method of preparing N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)benzenesulfonamides comprises the steps of:
condensing 3-chloro-1,2-benzisothiazole 1,1-dioxide with 2,2-dimethyl-1,3-dioxane-4,6-dione in methylene chloride in the presence of triethylamine to give 5-(1,2-benzisothiazol-3(2H)-ylidene 1,1-dioxide)-2,2-dimethyl-1,3-dioxane-4,6-dione and
heating 5-(1,2-benzisothiazol-3(2H)-ylidene 1,1- dioxide)-2,2-dimethyl-1,3-dioxane-4,6-dione with a benzenesulfonamide in refluxing toluene.
The method of preparation involves the following chemical reaction pathways: ##STR3##
The N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)benzenesulfonamides can generally tautomerize. Thus, the general structure could, in many cases, also include the following tautomeric forms: ##STR4##
For the sake of brevity, alternate tautomeric forms will not be illustrated herein. However, structural formulas should be understood to be inclusive of alternate tautomers.
In addition to tautomeric forms, the compositions of the invention may, with respect to the 3-ylidene double bond, exist as geometric isomers. Although the configuration of the compounds of the invention is unknown, both geometric isomers are considered to fall within the scope of the invention. ##STR5##
The following examples further clarify the method of the making the N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)benzenesulfonamides.
EXAMPLE
Step 1: Preparation of 5-(1,2-Benzisothiazol-3(2H)-ylidene 1,1-dioxide)-2,2-dimethyl-1,3-dioxane-4,6-dione. ##STR6##
A solution of 100.82 g (0.50 mol) of 3-chloro-1,2-benzisothiazole 1,1-dioxide (prepared by the method of Stephen, et al., J. Chem. Soc., 1957, 490), 72.07 g (0.50 mol) of 2,2-dimethyl-1,3-dioxane-4,6-dione and 1 L of methylene chloride was prepared and cooled in an ice/water bath. To this solution was added 101.19 g (1.00 mol) of triethylamine dropwise over 35 min. The cooling bath was removed and the reaction mixture was stirred for 17.5 hrs, washed with 10% HCl and twice with water. The solution was dried over magnesium sulfate, filtered and concentrated. The residue was washed with warm ligroine and then with acetone. The yellow solid was recrystallized from 2-butanone, collected, washed with ligroine and dried;
Step 2: Preparation of N-(1,2-Benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)-4-methylbenzenesulfonamide ##STR7##
A mixture of 3.09 g (10 mmol) of 5-(1,2-benzisothiazol-3(2H)-ylidene 1,1-dioxide)-2,2-dimethyl-1,3-dioxane-4,6-dione, 1.71 g (10 mmol) of p-toluenesulfonamide and 60 ml of dry toluene was heated at reflux for 30 mins and cooled. The solid was collected by filtration, washed with ligroine and dried.
Table 1 shows charge-control agents that can be prepared according to the above method and example.
TABLE 1______________________________________N-(1,2-Benzisothiazol-3(2H)-ylidineacetyl1,1-dioxide)benzenesulfonamides ##STR8##Charge-control agent number (X).sub.n______________________________________1 H2 4-CH.sub.33 4-Cl4 4-Br5 4-F6 4-NO.sub.27 3,5-(t-Bu).sub.2 -4-OH______________________________________
The charge-control agents of the invention also are essentially colorless and exhibit excellent thermal stability in air.
The toners provided by the invention includes a charge-control agent of the invention, in an amount effective to modify, and improve the properties of the toner. It is preferred that a charge-control agent improve the charging characteristics of a toner, so the toner quickly charges to a negative value having a relatively large absolute magnitude and then maintains about the same level of charge. The compositions used in the toners are negative charge-control agents, thus the toners of the invention achieve and maintain negative charges.
It is also preferred that a charge-control agent improve the charge uniformity of a toner composition, that is, it insure that substantially all of the individual toner particles exhibit a triboelectric charge of the same sign with respect to a given carrier. It is also preferred that a charge-control agent be colorless, particularly for use in light colored toners. The charge-control agents of the invention are essentially colorless. It is also preferred that a charge-control agent be metal free and have good thermal stability. The charge-control agents of the invention are metal free and have good thermal stability. Preferred materials described herein are based upon an evaluation in terms of a combination of characteristics rather than any single characteristic.
The binders used in formulating the toners of the invention with the charge-controlling additive of the present invention are polyesters having a glass transition temperature of 50° to 100° C. and a weight average molecular weight of 10,000 to 100,000. The polyesters are prepared from the reaction product of a wide variety of diols and dicarboxylic acids. Some specific examples of suitable diols are: 1,4-cyclohexanediol; 1,4-cyclohexanedimethanol; 1,4-cyclohexanediethanol; 1,4-bis(2-hydroxyethoxy)cyclohexane; 1,4-benzenedimethanol; 1,4-benzenediethanol; norbornylene glycol; decahydro-2,6-naphthalenedimethanol; bisphenol A; ethylene glycol; diethylene glycol; triethylene glycol; 1,2-propanediol, 1,3-propanediol; 1,4-butanediol; 2,3-butanediol; 1,5-pentanediol; neopentyl glycol; 1,6-hexanediol; 1,7-heptanediol; 1,8-octanediol; 1,9-nonanediol; 1,10-decanediol; 1,12-dodecanediol; 2,2,4-trimethyl-1,6-hexanediol; 4-oxa-2,6-heptanediol and etherified diphenols.
Suitable dicarboxylic acids include: succinic acid; sebacic acid; 2-methyladipic acid; diglycolic acid; thiodiglycolic acid; fumaric acid; adipic acid; glutaric acid; cyclohexane-1,3-dicarboxylic acid; cyclohexane-1,4-dicarboxylic acid; cyclopentane-1,3-dicarboxylic acid; 2,5-norbornanedicarboxylic acid; phthalic acid; isophthalic acid; terephthalic acid; 5-butylisophthalic acid; 2,6-naphthalenedicarboxylic acid; 1,4-naphthalenedicarboxylic acid; 1,5-naphthalenedicarobxylic acid; 4,4'-sulfonyldibenzoic acid; 4,4'-oxydibenzoic acid; binaphthyldicarboxylic acid; and lower alkyl esters of the acids mentioned.
Polyfunctional compounds having three or more carboxyl groups, and three or more hydroxyl groups are desirably employed to create branching in the polyester chain. Triols, tetraols, tricarboxylic acids, and functional equivalents, such as pentaerythritol, 1,3,5-trihydroxypentane, 1,5-dihydroxy-3-ethyl-3-(2-hydroxyethyl)pentane, trimethylolpropane, trimellitic anhydride, pyromellitic dianhydride, and the like are suitable branching agents. Presently preferred polyols are glycerol and trimethylolpropane. Preferably, up to about 15 mole percent, preferably 5 mole percent, of the reactant diol/polyol or diacid/polyacid monomersfor producing the polyesters can be comprised of at least one polyol having a functionality greater than two or poly-acid having a functionality greater than two.
Variations in the relative amounts of each of the respective monomer reactants are possible for optimizing the physical properties of the polymer.
The polyesters of this invention are conveniently prepared by any of the known polycondensation techniques, e.g., solution polycondensation or catalyzed melt-phase polycondensation, for example, by the transesterification of dimethyl terephthalate, dimethyl glutarate, 1,2-propanediol and glycerol.
The polyesters also can be prepared by two-stage polyesterification procedures, such as those described in U.S. Pat. Nos. 4,140,644 and 4,217,400. The latter patent is particularly relevant, because it is directed to the control of branching in polyesterification. In such processes, the reactant glycols and dicarboxylic acids, are heated with a polyfunctional compound, such as a triol or tricarboxylic acid, and an esterification catalyst in an inert atmosphere at temperatures of 190° to 280° C., especially 200° to 240° C. Subsequently, a vacuum is applied, while the reaction mixture temperature is maintained at 220° to 240° C., to increase the product's molecular weight.
The degree of polyesterification can be monitored by measuring the inherent viscosity (I.V.) of samples periodically taken from the reaction mixture. The reaction conditions used to prepare the polyesters should be selected to achieve an I.V. of 0.10 to 0.80 measured in methylene chloride solution at a concentration of 0.25 grams of polymer per 100 milliliters of solution at 250° C. An I.V. of 0.10 to 0.60 is particularly desirable to insure that the polyester has a weight average molecular weight of 10,000 to 100,000, preferably 55,000 to 65,000, a branched structure and a Tg in the range of about 50° to about 100° C. Amorphous polyesters are particularly well suited for use in the present invention. After reaching the desired inherent viscosity, the polyester is isolated and cooled.
One useful class of polyesters comprises residues derived from the polyesterification of a polymerizable monomer composition comprising:
a dicarboxylic acid-derived component comprising:
about 75 to 100 mole % of dimethyl terephthalate and
about 0 to 25 mole % of dimethyl glutarate and
a diol/poly-derived component comprising
about 90 to 100 mole % of 1,2-propanediol and
about 0 to 10 mole % of glycerol.
Many of the aforedescribed polyesters are disclosed in the patent to Alexandrovich et al, U.S. Pat. No. 5,156,937.
Another useful class of polyesters is the non-linear reaction product of a dicarboxylic acid and a polyol blend of etherified diphenols disclosed in U.S. Pat. Nos. 3,681,106; 3,709,684; and 3,787,526.
The etherified diphenols of U.S. Pat. No. 3,787,526 have the formula: ##STR9## wherein z is 0 or 1; R is an alkylene radical containing from 1 to 5 carbon atoms, a sulfur atom, an oxygen atom, or a radical characterized by the formula: ##STR10## R 1 is an ethylene or propylene radical; x and y are integers with the proviso that the sum of x and y in said polyol blend is an average of from about 2.0 to about 7; and each A is individually selected from the group consisting of hydrogen and halogen atoms; and from about 0.01 to about 2.0 mol percent of an alkoxylated polyhydroxy compound, which polyhydroxy compound contains from 3 to 12 carbon atoms and from 3 to 9 hydroxyl groups and wherein the alkoxylated polyhydroxy compound contains from 1 to 10 mols of oxyalkylene groups per hydroxyl group of said polyhydroxy compound and said oxyalkylene radical is ethylene or propylene;
the number of carboxyl groups of said dicarboxylic acid to the number of hydroxyl groups of said polyol blend is in a ratio of from about 1.2 to about 0.8.
Among those diphenols which are contemplated as the base for the etherified diphenols used in the preparation of the polyesters are:
2,2-bis(1-hydroxyphenyl) propane;
bis(4-hydroxyphenyl) ethane;
3,3-bis(4-hydroxyphenyl) pentane;
p,p'-dihydroxydiphenol;
4,4'-dihydroxydiphenyl ether;
4,4'-dihydroxydiphenyl thioether;
4,4'-dihydroxydiphenyl ketone;
2,2'-bis(4-hydroxy-2,6-dichlorophenyl) propane; 2-fluoro-4-hydroxyphenyl sulfoxide;
4,4'-dihydroxydiphenyl sulfone;
2,3,6-dichlorobromo-4-hydroxyphenyl-2,6-dichloro-4-hydroxyphenyl methane; and
2,2-bis(2,3,5,6-tetrabromo-4-hydroxyphenyl)butane.
A preferred group of etherified bisphenols within the class characterized by the above formula in U.S. Pat. No. 3,787,526 are polyoxypropylene 2,2'-bis(4-hydroxyphenyl) propane and polyoxyethylene or polyoxypropylene, 2,2-bis(4-hydroxy, 2,6-dichlorophenyl) propane wherein the number of oxyalkylene units per mol of bisphenol is from 2.1 to 2.5.
The etherified diphenols disclosed in U.S. Pat. No. 3,709,684 are represented by the formula: ##STR11## In this formula w represents an integer of 0 or 1; R is an alkylene radical of one to five carbon atoms, oxygen, sulfur or a divalent radical represented by the formula: ##STR12## Each A is individually selected from either a halogen atom or a hydrogen atom; the letters m and n are integers from 0 through 6 with the proviso that the sum of m and n is at least about 2 and less than 7; and X and Y are radicals which are individually selected from the following group: alkyl radicals of one to three carbon atoms, a phenyl radical, or a hydrogen atom; provided that in any X and Y pair on adjacent carbon atoms either X or Y is a hydrogen atom. A preferred group of etherified diphenols within the above formula include those where each A is either a chlorine atom or hydrogen and/or R is an alkylene radical containing one to three carbon atoms, and X and Y are either hydrogen or a methyl radical. In this preferred group the average sum of n and m is at most about 3. Examples of etherified diphenols within the above formula include the following: polyoxyethylene(3)-2,2-bis(4-hydroxyphenyl) propane; polyoxystyrene(6)-bis(2,6-dibromo-4-hydroxyphenyl) methane; polyoxybutylene(2.5)-bis(4-hydroxyphenyl) ketone; polyoxyethylene(3)-bis(4-hydroxyphenyl) ether; polyoxystyrene(2.8)-bis(2,6-dibromo-4-hydroxyphenyl) thioether; polyoxypropylene(3)bis(4-hydroxyphenyl) sulfone; polyoxystyrene(2)-bis(2,6-dichloro-4-hydroxyphenyl) ethane; polyoxyethylene(3)-bis(4-hydroxyphenyl) thioether; polyoxy-propylene(4)-4,4'-bisphenol; polyoxyethylene(7)-bis(2,3,6-trifluorodichloro-4-hydroxyphenyl) ether; polyoxyethylene(3.5)-4,4-bis(4-hydroxyphenyl) pentane; polyoxystyrene(4)-2-fluoro-4-hydroxyphenyl, 4-hydroxyphenyl sulfoxide; and polyoxybutylene(2)-3,2-bis(2,3,6-tribromo-4-hydroxyphenyl) butane.
A class of readily available etherified diphenols within the above formula from U.S. Pat. No. 3,709,684 are the bisphenols. A preferred class of etherified bisphenols are those prepared from 2,2-bis(4-hydroxy-phenyl) propane or the corresponding 2,6,2',6'-tetrachloro or tetrafluoro bisphenol alkoxylated with from 2 to 4 mols of propylene or ethylene oxide per mol of bisphenol.
The etherified diphenols disclosed in U.S. Pat. No. 3,681,106 have the formula: ##STR13## wherein z is 0 or 1, R is an alkylene radical containing from 1 to 5 carbon atoms, a sulfur atom, an oxygen atom, ##STR14## X and Y are individually selected from the group consisting of alkyl radicals containing from 1 to 3 carbon atoms, hydrogen, and a phenyl radical with the limitation that at least X or Y is hydrogen in any X and Y pair on adjacent carbon atoms, n and m are integers with the proviso that the average sum of n and m is from about 2 to about 7; and each A is either a halogen atom or a hydrogen atom. An average sum of n and m means that in any polyol blend some of the etherified diphenols within the above formula may have more than 7 repeating ether units but that the average value for the sum of n and m in any polyhydroxy composition is from 2 to 7. Examples of compounds within the above general formula from U.S. Pat. No. 3,681,106 are:
polyoxystyrene(6)-2,2-bis(4-hydroxyphenyl) propane;
polyhydroxybutylene(2)-2,2-bis(4-hydroxyphenyl) propane;
polyoxyethylene(3)-2,2-bis(4-hydroxyphenyl) propane;
polyoxypropylene(3)-bis(4-hydroxyphenyl) thioether;
polyoxyethylene(2)-2,6-dichloro-4-hydroxyphenyl, 2',3',6'-trichloro-4'-hydroxyphenyl methane;
polyoxypropylene(3)-2-bromo-4-hydroxyphenyl, 4'-hydroxyphenyl ether;
polyoxyethylene(2.5)-p,p-bisphenol;
polyoxybutylene(4)-bis(4-hydroxyphenyl) ketone;
polyoxystyrene(7)-bis(4-hydroxyphenyl) ether;
polyoxypentylene(3)-bis(2,6-diiodo-4-hydroxyphenyl) propane; and
polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl) propane.
A preferred group of said etherified diphenols are those where the average sum of n and m is from about 2 to about 3. Thus, although the sum of n and m in a given molecule may be as high as about 20, the average sum in the polyol composition will be about 2 to about 3. Examples of these preferred etherified diphenols include:
polyoxyethylene(2.7)-4-hydroxyphenyl-2-chloro-4-hydroxyphenyl ethane;
polyoxyethylene(2.5)-bis(2,6-dibromo-4-hydroxyphenyl) sulfone;
polyoxypropylene(3)-2,2-bis(2,6-difluoro-4-hydroxyphenyl) propane; and
polyoxyethylene(1.5)-polyoxypropylene(1.0)-bis(4-hydroxyphenyl) sulfone.
A preferred polyhydroxy composition used in said polyester resins are those polyhydroxy compositions containing up to 2 mol percent of an etherified polyhydroxy compound, which polyhydroxy compound contains from 3 to 12 carbon atoms and from 3 to 8 hydroxyl groups. Exemplary of these polyhydroxy compounds are sugar alcohols, sugar alcohol anhydrides, and mono and disaccharides. A preferred group of said polyhydroxy compounds are soribitol, 1,2,3,6-hexantetrol; 1,4-sorbitan; pentaerythritol, xylitol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol; xylitol; sucrose, 1,2,4-butanetriol; and erythro and threo 1,2,3-butanetriol. Said etherified polyhydroxy compounds are propylene oxide or ethylene oxide derivatives of said polyhydroxy compounds containing up to about 10 molecules of oxide per hydroxyl group of said polyhydroxy compound and preferably at least one molecule of oxide per hydroxyl group. More preferably the molecules of oxide per hydroxyl group is from 1 to 1.5. Oxide mixtures can readily be used. Examples of these derivatives include polyoxyethylene(20) pentaerythritol, polyoxypropylene(6) sorbitol, polyoxyethylene(65) sucrose, and polyoxypropylene(25) 1,4-sorbitan. The polyester resins prepared from this preferred polyhydroxy composition are more abrasion resistant and usually have a lower liquid point than other crosslinked polyesters herein disclosed.
Polyesters that are the non-linear reaction product of a dicarboxylic acid and a polyol blend of etherified polyhydroxy compounds, discussed above, are commercially available from Reichold Chemical Company. To illustrate the invention the examples provided herein use an poly(etherified bisphenol A fumarate) sold as Atlac 382ES by Reichold.
An optional but preferred component of the toners of the invention is colorant: a pigment or dye. Suitable dyes and pigments are disclosed, for example, in U.S. Pat. No. Re. 31,072 and in U.S. Pat. Nos. 4,160,644; 4,416,965; 4,414,152; and 2,229,513. One particularly useful colorant for toners to be used in black and white electrostatographic copying machines and printers is carbon black. Colorants are generally employed in the range of from about 1 to about 30 weight percent on a total toner powder weight basis, and preferably in the range of about 2 to about 15 weight percent.
The toners of the invention can also contain other additives of the type used in previous toners, including leveling agents, surfactants, stabilizers, and the like. The total quantity of such additives can vary. A present preference is to employ not more than about 10 weight percent of such additives on a total toner powder composition weight basis.
The toners can optionally incorporate a small quantity of low surface energy material, as described in U.S. Pat. Nos. 4,517,272 and 4,758,491. Optionally the toner can contain a particulate additive on its surface such as the particulate additive disclosed in U.S. Pat. No. 5,192,637.
A performed mechanical blend of particulate polymer particles, charge-control agent, colorants and additives can, alternatively, be roll milled or extruded at a temperature sufficient to melt blend the polymer or mixture of polymers to achieve a uniformly blended composition. The resulting material, after cooling, can be ground and classified, if desired, to achieve a desired toner powder size and size distribution. For a polymer having a "T g " in the range of about 50° C. to about 120° C., a melt blending temperature in the range of about 90° C. to about 150° C. is suitable using a roll mill or extruder. Melt blending times, that is, the exposure period for melt blending at elevated temperature, are in the range of about 1 to about 60 minutes. After melt blending and cooling, the composition can be stored before being ground. Grinding can be carried out by any convenient procedure. For example, the solid composition can be crushed and then ground using, for example, a fluid energy or jet mill, such as described in U.S. Pat. No. 4,089,472. Classification can be accomplished using one or two steps.
In place of blending, the polymer can be dissolved in a solvent in which the charge-control agent and other additives are also dissolved or are dispersed. The resulting solution can be spray dried to produce particulate toner powders. Limited coalescence polymer suspension procedures as disclosed in U.S. Pat. No. 4,833,060 are particularly useful for producing small sized, uniform toner particles.
The toner particles have an average diameter between about 0.1 micrometers and about 100 micrometers, and desirably have an average diameter in the range of from about 1.0 micrometer to 30 micrometers for currently used electrostatographic processes. The size of the toner particles is believed to be relatively unimportant from the standpoint of the present invention; rather the exact size and size distribution is influenced by the end use application intended. So far as is now known, the toner particles can be used in all known electrostatographic copying processes.
The amount of charge-control agent used typically is in the range of about 0.2 to 10.0 parts per hundred parts of the binder polymer. In particularly useful embodiments, the charge-control agent is present in the range of about 1.0 to 4.0 parts per hundred.
The developers of the invention include carriers and toners of the invention. Carriers can be conductive, non-conductive, magnetic, or non-magnetic. Carriers are particulate and can be glass beads; crystals of inorganic salts such as ammonium chloride, or sodium nitrate; granules of zirconia, silicon, or silica; particles of hard resin such as poly(methyl methacrylate); and particles of elemental metal or alloy or oxide such as iron, steel, nickel, carborundum, cobalt, oxidized iron and mixtures of such materials. Examples of carriers are disclosed in U.S. Pat. Nos. 3,850,663 and 3,970,571. Especially useful in magnetic brush development procedures are iron particles such as porous iron, particles having oxidized surfaces, steel particles, and other "hard" and "soft" ferromagnetic materials such as gamma ferric oxides or ferrites of barium, strontium, lead, magnesium, copper, zinc or aluminum. Copper-zinc ferrite powder is used as a carrier in the examples hereafter. Such carriers are disclosed in U.S. Pat. Nos. 4,042,518; 4,478,925; and 4,546,060.
Carrier particles can be uncoated or can be coated with a thin layer of a film-forming resin to establish the correct triboelectric relationship and charge level with the toner employed. Examples of suitable resins are the polymers described in U.S. Pat. Nos. 3,547,822; 3,632,512; 3,795,618 and 3,898,170 and Belgian Patent No. 797,132. Polymeric silane coatings can aid the developer to meet the electrostatic force requirements mentioned above by shifting the carrier particles to a position in the triboelectric series different from that of the uncoated carrier core material to adjust the degree of triboelectric charging of both the carrier and toner particles. The polymeric silane coatings can also reduce the frictional characteristics of the carrier particles in order to improve developer flow properties; reduce the surface hardness of the carrier particles to reduce carrier particle breakage and abrasion on the photoconductor and other components; reduce the tendency of toner particles or other materials to undesirably permanently adhere to carrier particles; and alter electrical resistance of the carrier particles.
In a particular embodiment, the developer of the invention contains from about 1 to about 20 percent by weight of toner of the invention and from about 80 to about 99 percent by weight of carrier particles. Usually, carrier particles are larger than toner particles. Conventional carrier particles have a particle size of from about 5 to about 1200 micrometers and are generally from 20 to 200 micrometers.
The toners of the invention are not limited to developers which have carrier and toner, and can be used, without carrier, as single component developer.
The toner and developer of the invention can be used in a variety of ways to develop electrostatic charge patterns or latent images. Such developable charge patterns can be prepared by a number of methods and are then carried by a suitable element. The charge pattern can be carried, for example, on a light sensitive photoconductive element or a non-light-sensitive dielectric surface element, such as an insulator coated conductive sheet. One suitable development technique involves cascading developer across the electrostatic charge pattern. Another technique involves applying toner particles from a magnetic brush. This technique involves the use of magnetically attractable carrier cores. After imagewise deposition of the toner particles the image can be fixed, for example, by heating the toner to cause it to fuse to the substrate carrying the toner. If desired, the unfused image can be transferred to a receiver such as a blank sheet of copy paper and then fused to form a permanent image.
The invention is further illustrated by the following Examples.
Preparation of Toners
A poly(etherified bisphenol A fumarate) was heated and melted on a 4 inch two roll melt compounding mill. The polyester base polymer was Atlac 382ES manufactured by Reichold Chemical. One roll was heated and controlled to a temperature of 120° C., the other roll was cooled with chilled water. After melting the polyester, the charge-control agent and any pigments were added to the melt. A typical batch formula was 50 g of polyester and 0.5 g of charge-control agent, giving a product with 1 part charge-control agent per 100 parts of polymer. The melt was compounded for 20 minutes, peeled from the mill and cooled. The melt was then coarse ground to approximately 2 mM in a laboratory mechanical mill and then fine ground in a Trost TX air jet mill. The ground toner had a mean particle size of approximately 8.5 μm.
Clear toners (toners containing only charge-control agent and polyester) were made for each charge-control agent example. A control toner containing no charge-control agent was made by the same compounding and grinding procedure.
Black and magenta toners, with and without(control) charge-control agents, were made using the same technique.
Black toners were made using Cabot Regal 300 carbon black added to the polymer melt while roll milling. Carbon black concentrations were 5 parts carbon per 100 parts of polyester.
Magenta toners were made by adding a magenta pigment to the melt while melt compounding. Pigment Red 57:1 was used. PR 57:1 is the pigment/polyester concentrate. Pigments were used in the concentration of 8.4 parts pigment/100 parts polymer.
Preparation of Developers
Developers (toners and carrier particles) were made for each prepared toner composition, including control toners. The carrier was a copper-zinc ferrite powder with a particle size of approximately 60 μm. The ferrite particles were coated with a polysilane. The carrier was made by Powdertech Corporation. Developers were made by blending 20 g of carrier and 0.8 g of toner. The toner concentration was 4 parts toner per 100 parts carrier.
Surface Treatment
Developers containing black or magenta pigmented toners are frequently surface treated with silica to improve their powder flow properties. Accordingly developers, containing black or magenta toners and carriers, were surface treated by adding amorphous silica powder to the carrier and toner blend. The silica had a specific BET surface area of 110 m 2 /g. Degussa R972 silica was used for surface treatment. For each surface treated developer, 0.004 g of silica was added to a mixture of 0.8 g of toner and 20 g of carrier to give a silica concentration of 0.5 parts per 100 parts of toner.
Measurement of Toner Charge
The various developers were separately exercised by shaking a vial containing 20 g of developer on a wrist shaker with an amplitude of approximately 11 cm and frequency of 120 Hz. The developer was shaken and samples taken after 2, 10, 60, and 120 minutes of exercising.
A weighed sample (about 0.15 g) of the exercised developer was placed on a 50 micron mesh wire screen. Toner was removed by passing a vacuum tube containing a fine mesh filter across the backside of the screen. The tube was brass and insulated from the screen by a plastic tip. The brass tube body was connected to an electrometer that measured the total charge in microcoulombs on the toner collected by the filter. After all the toner was removed from the carrier the total charge was recorded and the filter containing toner removed and weighed. The charge to mass ratio (Q/m) of the toner was calculated by dividing the total charge by the toner weight to give Q/m in microcoulombs per gram (μc/g).
Results of these measurements for clear, black and magenta toners are presented hereafter in Table 2.
Evaluation of Charging Properties
Effective charge-control agents are ones that increase the absolute charge level of the toner relative to the control toner containing no charge-control agent. The level of charge can generally be increased by increasing the concentration of the charge control agent.
Surface treatment of toner with fine silica improves the image quality of prints made with it, and also effects the triboelectric properties of the toner. Silica surface treatment has the effect of raising the absolute initial charge/mass level of a toner. The charge level of a black surface treated toner containing no charge-control agent measured at 2 and 10 minutes is significantly higher than the same formulation with no surface treatment. Surface treatment has little to no effect on the Q/m of toners after 60 and 120 minutes exercise time.
Effective charge-control agent in silica surface treated toners raises the Q/m of toners that have been exercised 60 and 120 minutes. Such toners will give more consistent print densities and image quality in electrophotographic printers.
Toners that charge rapidly and maintain that charge with extended exercise time are desirable. The initial Q/m indicates if the toner is charging rapidly. Measurements at 60 and 120 minutes indicate whether the material is maintaining a constant charge with life. This exercise time represents the mixing that the developer experiences in a electrophotographic printer.
Exercised toners that show a little or no decrease in Q/m over time are preferred over formulations that show a large decrease. A toner with a constant charge level will maintain a consistent print density when compared to a formulation that does not have a constant charge/mass level.
Table 2 establishes that the N-(1,2-benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)benzenesulfonamides are effective charge control agents for clear, black and color toners.
TABLE 2______________________________________N-(1,2-Benzisothiazol-3(2H)-ylideneacetyl1,1-dioxide)benzenesulfonamidesCharge-Control Properties ##STR15##Charge-controlagent -Q/mnumber (X).sub.n pph 2 min 10 min 60 min 120 min______________________________________Clear TonerControl 0.0 36.2 38.9 39.7 40.01 4-CH.sub.3 0.25 31.2 40.2 46.2 44.6 1.0 38.4 50.3 60.7 60.42 H 1.0 56.7 71.1 88.0 86.9 4.0 96.3 112.0 123.0 120.73 4-Cl 1.0 66.9 86.3 95.2 91.9 4.0 93.1 110.6 116.4 107.94 4-Br 1.0 67.0 91.6 99.3 95.7 4.0 82.7 103.8 113.1 117.15 4-F 1.0 74.6 94.2 100.2 99.0 4.0 79.9 93.5 117.2 126.26 4-NO.sub.2 1.0 62.9 87.2 97.7 94.2 4.0 90.0 112.8 113.7 116.4Black Toner Treated With SilicaControl 0.00 29.8 28.8 22.8 16.32 H 0.1 35.5 34.1 27.3 22.0 0.25 36.5 36.4 28.8 24.2 1.0 38.8 38.6 33.0 23.83 4-Cl 0.1 40.2 40.7 29.6 25.3 0.25 43.2 43.6 32.5 27.8 1.0 45.7 46.8 36.6 33.1Magenta (PR 57:1) Toner With SilicaControl 0.00 45.1 40.2 34.8 34.22 H 1.0 60.5 55.7 49.0 45.7 4.0 62.8 63.9 61.5 55.9______________________________________
While specific embodiments of the invention have been shown and described herein for purposes of illustration, the protection afforded by any patent which may issue upon this application is not strictly limited to a disclosed embodiment; but rather extends to modifications and arrangements which fall fairly within the scope of the claims which are appended hereto.
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N-(1,2-Benzisothiazol-3(2H)-ylideneacetyl 1,1-dioxide)benzenesulfonamides are disclosed. They have the general structure ##STR1## X and n are defined in the specification.
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BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to organic (acrylate based) printing mediums that can be cured using free-radical initiators without the use of low boiling solvents, and which accordingly release low levels of volatile organic compounds.
2. Description of Related Art
Conventional mediums for screen-printing and roll-coating useful for ceramic applications include solvents and organic binder resins. Some may require ultraviolet light to cure. Solvent-based systems accordingly exude high concentrations of volatile organic compounds (VOCs), in the range of 300-400 grams per liter or greater. Ultraviolet curable coatings are limited to a film thickness of about 30 microns and require ultraviolet lamps to cure. The curable acrylate-based printing medium of the invention overcomes these drawbacks, both with respect to VOC release and film thickness.
BRIEF SUMMARY OF THE INVENTION
The present invention provides an acrylic based curable printing medium that can be cured without the use of special ultraviolet curing equipment. The mediums of the invention can be cured with heat alone, such as convection heating or infrared heating. The medium can be printed or otherwise applied to far greater thicknesses than UV curable mediums and cured quickly with the release of extremely low amounts of volatile organic chemicals (VOC). Curing agents such as photoinitiators are not necessary and are preferably excluded.
Acrylates, in the form of monomers, dimers, trimers, oligomers, and resins, form an interpenetrating polymer network by crosslinking, which is effected by heat and the optional use of curing agents such as peroxides. Formulations can be tailored to achieve desired properties of the cured polymer including film hardness, burnout properties, and adhesion to glass or other substrates. Such properties are adjusted by manipulating the relative proportions of the acrylic monomers, oligomers and resins that are used to form the medium of the invention.
Broadly, the inventive composition is a printable medium or vehicle that includes unsaturated carbon-carbon bonds, which is cured via free radical polymerization that is initiated by heat and optional temperature-sensitive initiators. Reducing agents may also be used in addition to the foregoing. Ultraviolet energy is not required, and indeed, will not work to cure the systems of the invention. Absent photoinitiators, the use of ultraviolet light will not be sufficient to cure the systems described herein.
The medium of the invention includes various combinations of functional acrylate monomers (monofunctional through pentafunctional), acrylic oligomers and acrylic resins. Metal driers are optionally useful. Free-radical scavengers can be added to the formulation in order to ensure a long shelf life, i.e., in-can stabilizers.
In particular, an embodiment of the invention is a low VOC, heat-curable medium comprising: (a) 20-95 wt %, preferably 30-80 wt %, more preferably 35-70 wt %, of a functional acrylate monomer having at least one functionality, (b) 0.1-20 wt %, preferably 1-18 wt %, more preferably 2-15 wt % of a solvent having a boiling point of at least 150° C., preferably at least 175° C., more preferably at least 200° C. at STP, (c) up to 20 wt %, preferably 0.1-18 wt %, more preferably 1-15 wt % of an acrylic resin, and (d) up to 15 wt %, preferably 0.5-12 wt % more preferably 1-10 wt % of an oligomer including at least one of a polyester residue and a urethane residue.
Another embodiment of the invention is a medium such as in the preceding paragraph, wherein the acrylic resin is present in an amount of 0.1-20 wt % of the medium, and wherein the acrylic resin has a general formula selected from the group consisting of (a) R 1 C(O)OR, (b) Ar 1 C(O)OR, (c) Ar 1 R 1 C(O)OR, (d) R 1 Ar 1 C(O)OR, and combinations thereof, wherein Ar 1 is an aromatic residue having up to 30 carbons, that is optionally substituted with at least one substituent selected from the group consisting of —OH, C 1 -C 4 -alkoxy, C 1 -C 4 -alkoxycarbonyl or carbonyl, wherein R 1 is an aliphatic residue having up to 15 carbons, that is optionally substituted with at least one substituent selected from the group consisting of —OH, C 1 -C 4 -alkoxy, C 1 -C 4 -alkoxycarbonyl or carbonyl, and wherein either or both of Ar 1 or R 1 may be C 5 -C 10 -cycloalkyl which is optionally mono- or polysubstituted by C 1 -C 4 -alkyl, —OH, C 1 -C 4 -alkoxy, C 1 -C 4 -alkoxycarbonyl or carbonyl, and combinations thereof.
Yet another embodiment of the invention is a method of forming a decorated glass structure comprising: (a) applying to a first glass substrate an enamel paste composition comprising, (i) a glass component, and (ii) a low VOC, heat-curable medium comprising: (1) 20-95 wt % of a functional acrylate monomer having at least one functionality, (2) 0.1-20 wt % of a solvent having a boiling point above 200° C. at STP, (3) up to 20 wt % of an acrylic resin, and (4) up to 15 wt % of an oligomer including at least one of a polyester residue and a urethane residue, (b) curing the medium by exposure to heat, heating the medium to a maximum of 204° C., thereby firmly adhering the medium to the first substrate, (c) stacking a second glass substrate with the first glass substrate wherein the cured paste-medium lies between the first and second glass substrates, and (d) subjecting the stacked glass substrates to a firing operation upon completion of which, (i) only the first glass substrate bears a sintered enamel composition, (ii) the medium burns out substantially completely, and (iii) the glass substrates do not stick to one another.
Yet another embodiment of the invention is a method of making a solar cell contact comprising: (a) applying a paste to a silicon wafer, wherein the paste comprises (i) a metal component including at least one of silver and aluminum, (ii) a glass component including at least one glass frit, and (iii) a low VOC, heat-curable medium comprising: (1) 20-95 wt % of a functional acrylate monomer having at least one functionality, (2) 0.1-20 wt % of a solvent having a boiling point above 200° C. at STP, (3) up to 20 wt % of an acrylic resin, and (4) up to 15 wt % of an oligomer including at least one of a polyester residue and a urethane residue, and (b) firing the paste to form the contact.
An embodiment of the invention is a method of forming a decorated glass structure comprising: (a) applying to a first glass substrate an enamel composition comprising, prior to firing: (i) a glass component and (ii) an acrylate based medium, (b) curing the medium, (c) stacking a second glass substrate with the first glass substrate wherein the glass component and medium lie between the first and second glass substrates, and (d) firing the glass substrates wherein (i) the glass component fuses to the first glass substrate, (ii) the medium completely burns out, and (iii) the glass substrates do not stick to one another.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the invention is a low VOC, heat-curable medium comprising: (a) 20-95 wt %, preferably 30-80 wt %, more preferably 35-70 wt %, of a functional acrylate monomer having at least one functionality, (b) 0.1-20 wt %, preferably 1-18 wt %, more preferably 2-15 wt % of a solvent having a boiling point of at least 150° C., preferably at least 175° C., more preferably at least 200° C. at STP, (c) up to 20 wt %, preferably 0.1-18 wt %, more preferably 1-15 wt % of an acrylic resin, and (d) up to 15 wt %, preferably 0.5-12 wt % more preferably 1-10 wt % of an oligomer including at least one of a polyester residue and a urethane residue.
Another embodiment of the invention is a medium such as in the preceding paragraph, wherein the acrylic resin is present in an amount of 0.1-20 wt % of the medium, and wherein the acrylic resin has a general formula selected from the group consisting of (a) R 1 C(O)OR, (b) Ar 1 C(O)OR, (c) Ar 1 R 1 C(O)OR, (d) R 1 Ar 1 C(O)OR, and combinations thereof, wherein Ar 1 is an aromatic residue having up to 30 carbons, that is optionally substituted with at least one substituent selected from the group consisting of —OH, C 1 -C 4 -alkoxy, C 1 -C 4 -alkoxycarbonyl or carbonyl, wherein R 1 is an aliphatic residue having up to 15 carbons, that is optionally substituted with at least one substituent selected from the group consisting of —OH, C 1 -C 4 -alkoxy, C 1 -C 4 -alkoxycarbonyl or carbonyl, and wherein either or both of Ar 1 or R 1 may be C 5 -C 10 -cycloalkyl which is optionally mono- or polysubstituted by C 1 -C 4 -alkyl, —OH, C 1 -C 4 -alkoxy, C 1 -C 4 -alkoxycarbonyl or carbonyl, and combinations thereof.
Yet another embodiment of the invention is a method of forming a decorated glass structure comprising: (a) applying to a first glass substrate an enamel paste composition comprising: (i) a glass component, and (ii) a low VOC, heat-curable medium comprising: (1) 20-95 wt % of a functional acrylate monomer having at least one functionality, (2) 0.1-20 wt % of a solvent having a boiling point above 200° C. at STP, (3) up to 20 wt % of an acrylic resin, and (4) up to 15 wt % of an oligomer including at least one of a polyester residue and a urethane residue, (b) curing the medium by exposure to heat, heating the medium to a maximum of 204° C., thereby firmly adhering the medium to the first substrate, (c) stacking a second glass substrate with the first glass substrate wherein the cured paste-medium lies between the first and second glass substrates, and (d) subjecting the stacked glass substrates to a firing operation upon completion of which, (i) only the first glass substrate bears a sintered enamel composition, (ii) the medium burns out substantially completely, and (iii) the glass substrates do not stick to one another.
Yet another embodiment of the invention is a method of making a solar cell contact comprising: (a) applying a paste to a silicon wafer, wherein the paste comprises (i) a metal component including at least one of silver and aluminum, (ii) a glass component including at least one glass frit, and (iii) a low VOC, heat-curable medium comprising: (1) 20-95 wt % of a functional acrylate monomer having at least one functionality, (2) 0.1-20 wt % of a solvent having a boiling point above 200° C. at STP, (3) up to 20 wt % of an acrylic resin, and (4) up to 15 wt % of an oligomer including at least one of a polyester residue and a urethane residue, and (b) firing the paste to form the contact.
An embodiment of the invention is a method of forming a decorated glass structure comprising: (a) applying to a first glass substrate an enamel composition comprising, prior to firing: (i) a glass component and (ii) an acrylate based medium, (b) curing the medium, (c) stacking a second glass substrate with the first glass substrate wherein the glass component and medium lie between the first and second glass substrates, and (d) firing the glass substrates wherein (i) the glass component fuses to the first glass substrate, (ii) the medium completely burns out, and (iii) the glass substrates do not stick to one another.
The mediums of the invention release less than 250 grams per liter of volatile organic compounds (VOCs), preferably less than 200 g/l, more preferably less than 150 g/l, more preferably still less than 140 g/l, more preferably less than 125 g/l. In the presently most preferred embodiment, the VOC level is no greater than 120 g/l.
The phrase “up to” is intended to mean that the indicated ingredient may or may not be present. The phrase “does not exceed” means that the ingredient in question is positively present in a measurable quantity, up to the recited maximum. In the absence of other guidance, the lower boundary of a range signified by “does not exceed” is 0.01%.
The invention includes an organic medium useful in printing and rollcoating on substrates including glass. The medium includes a functional acrylate monomer, an optional acrylic resin, and an optional oligomer containing acrylate monomers. Details on each constituent follow.
Acrylates. Monofunctional acrylates useful herein include those in a molecular weight range of about 150 to about 400. Generally, monofunctional acrylates including at least one of a C 1 -C 20 aliphatic group and a C 6 -C 30 aromatic group, are suitable. Specific examples include for example, 2(2-ethoxyethoxy) ethyl acrylate (188); 2-phenoxyethyl acrylate (192); isodecyl acrylate (212); lauryl acrylate (254); and stearyl acrylate (324); where the numbers in parenthesis indicate the approximate molecular weight of a particular acrylate. Alkoxylated aliphatic acrylates with molecular weight range of 150 to 400 are generally useful.
Difunctional acrylates useful herein include those in a molecular weight range of about 250 to about 500. Generally, difunctional acrylates including at least one of a C 2 -C 22 aliphatic group and a C 6 -C 30 aromatic group are suitable. Specific examples include for example, dipropylene glycol diacrylate (242); triethylene glycol diacrylate (258); tripropylene glycol diacrylate (300); propoxylated neopentyl glycol diacrylate (328); and alkoxylated aliphatic diacrylate (330).
Generally, trifunctional acrylates useful herein include those in a molecular weight range of about 400 to about 1200. Trifunctional acrylates including at least one of a C 2 -C 24 aliphatic group and a C 6 -C 36 aromatic group are suitable. For example, pentaerythritol triacrylate (298); ethoxylated 3 trimethylolpropane triacrylate (428); ethoxylated 20 trimethylolpropane triacrylate (i.e., icosa-ethoxy trimethylol propane) (1176); and propoxylated 3 trimethylolpropane triacrylate (470).
Useful oligomers herein include those in a molecular weight range of about 600-1800. Such oligomers include, for example, generic examples acrylated polyester-urethane copolymer (800 to 1,800); acrylated urethane (600-1200); and acrylated polyester (600-1200).
For example, a useful acrylated polyester/urethane copolymer is that sold by Lord Corporation of Erie, Pa., under the product name PE 5271-20, having a molecular weight of 1,200 to 1,500. Others include ZL-1178 from Thiokol, and CN984 urethane acrylate from Sartomer Corporation.
Resins. Useful resins include polymethyl methacrylate and polyethyl methacrylate, Elvacite™ 2043, Elvacite™ 2045, Paraloid™ B-67, Paraloid™ B-72, and polyisobutyl methacrylate having molecular weights in the range of 30,000 to 150,000. Elvacite™ 2043 is a polyethylmethacrylate resin. The resins are not involved in the crosslinking reaction, but act as a matrix in which the reactive components are distributed. Other non-reactive acrylic resins can be used in place of the Elvacite products.
Curing Agents. Curing agents are optional, but can help to increase curing rates. Free radical initiators such as peroxides may be used, for example hydrogen peroxide, sodium peroxide, potassium peroxide, p-anisoyl peroxide, benzoyl peroxide, dibenzoyl peroxide; t-butyl hydroperoxide, t-amyl hydroperoxide, 2,4,-dicumyl α,α′di(t-butylperoxy)-diisopropyl benzene; 2,5-dimethyl, 2,5-di-(t-butylperoxy) hexane; 2,5-dimethyl, 2,5-di-(t-butylperoxy) hexyne; n-butyl, 4,4-di-(t-butylperoxy)valerate; 1,1-bis-(t-butylperoxy)-3,3,5-trimethyl-cyclohexane; t-butyl perbenzoate, methyl-ethyl ketone peroxide, lauroyl peroxide, and combinations thereof. Specific commercials include Varox® from RT Vanderbilt Co. Inc, Norwalk, Conn.
When they are used, the curing agents are used typically at a level of 0.1-5 wt %, preferably 0.5-4 wt % and more preferably 1% to 3% by weight, based on the weight of total monomer.
Other free radical initiators, that is, reducing agents, such as ammonium and/or alkali metal persulfates, sodium perborate, perphosphoric acid and salts thereof, potassium permanganate, and ammonium or alkali metal salts of peroxydisulfuric acid, can be used. Redox systems using the same initiators coupled with a suitable reductant such as, for example, sodium sulfoxylate formaldehyde, ascorbic acid, isoascorbic acid, alkali metal and ammonium salts of sulfur-containing acids, such as the sulfite, bisulfite, thiosulfate, hydrosulfite, sulfide, hydrosulfide or dithionite of sodium or other alkali metal or alkaline earth metal, formamidinesulfinic acid, hydroxymethanesulfonic acid, acetone bisulfite; amines such as ethanolamine, glycolic acid, glyoxylic acid hydrate, lactic acid, glyceric acid, malic acid, tartaric acid and salts of the preceding acids may be used. Additionally, any salt or other compound providing Fe +2 , ions, S 2 O 3 −2 ions, or HSO 3 − ions is suitable.
Catalysts. Metal driers act as catalysts for the peroxide curing agents. Metal driers generally include redox reaction catalyzing metal salts (typically carboxylic acid salts) of iron, copper, manganese, silver, platinum, vanadium, nickel, chromium, palladium, or cobalt.
Specific metal driers are metal oxides or organometallic compounds of metals such as, for example, the acetate, formate, oxalate, citrate, acetylacetonate, 2-ethylhexanoate of the aforementioned metals. Specific examples include cobalt napthanate, cobalt linolenate, cobalt acetate, iron acetate, manganese linolenate, and zinc oxalate. The methods of crosslinking herein do not involve, and the curable mediums herein are not made with, photoinitiators. Preferred embodiments of the invention do not include intentionally added photoinitiators, and more preferably, wholly exclude photoinitiators, both in the methods of curing, and in making the mediums covered in the claims.
Solvents. High boiling solvents can be used, i.e., those that do not produce volatile organic chemicals upon drying, curing, or burnout (upon firing). Suitable solvents include 2,2,4-trimethyl pentanediol monoisobutyrate (Texanol™); Methyl Ether of C9 to C11 ethoxylated alcohol, Higlyme™; tetraglyme, soy methyl ester, butoxy triglycol, tripropylene glycol n-butyl ether, solusol 2075, certain VOC exempt solvents such as propylene carbonate and dimethyl carbonate, vegetable oils, mineral oils, low molecular weight petroleum fractions, tridecyl alcohols, and synthetic or natural resins and blends thereof. Surfactants and/or other film forming modifiers can also be included. Solvents having a minimum boiling point of 200° C. are generally suitable herein.
Heat or photo-initiators or both can be applied to an acrylate curable system along with a free-radical initiator. Prior art UV curing exposes the prior art UV-curable system to UV radiation for less than 2 seconds. Prior art UV curable systems involve a UV curable medium together with enamel powder, while prior art solvent based systems involve resins and enamel powder.
Dispersing Surfactant. A dispersing surfactant assists in pigment wetting, when an insoluble particulate inorganic pigment is used. A dispersing surfactant typically contains a block copolymer with pigment affinic groups. For example, surfactants sold under the Disperbyk® and Byk® trademarks by Byk Chemie of Wesel, Germany, such as Disperbyk® 162 and 163, which are solutions of high molecular weight block copolymers with pigment affinic groups, and a blend of solvents (xylene, butylacetate and methoxypropylacetate). Disperbyk® 162 has these solvents in a 3/1/1 ratio, while the ratio in Disperbyk® 163 is 4/2/5. Disperbyk® 140 is a solution of alkyl-ammonium salt of an acidic polymer in a methoxypropylacetate solvent.
Rheological Modifier. A rheological modifier is used to adjust the viscosity of the medium. A variety of rheological modifiers may be used, including those sold under the Byk®, Disperplast®, and Viscobyk® trademarks, available from Byk Chemie. They include, for example, the BYK™ 400 series, such as BYK 411 and BYK 420, (modified urea solutions); the BYK W-900 series, (pigment wetting and dispersing additives); the Disperplast® series, (pigment wetting and dispersing additives for plastisols and organosols); and the Viscobyk® series, (viscosity depressants for plastisols and organosols).
A flow aid is type of rheological modifier, which affects the flow properties of liquid systems in a controlled and predictable way. Rheology modifiers are generally considered as being either pseudoplastic or thixotropic in nature. Suitable rheological modifiers useful herein include those sold commercially under the Additol®, Multiflow®, and Modaflow® trademarks by UCB Surface Specialties of Smyrna, Ga. For example, Additol VXW 6388, Additol VXW 6360, Additol VXL 4930, Additol XL 425, Additol XW 395, Modaflow AQ 3000, Modaflow AQ 3025, Modaflow Resin, and Multiflow Resin.
Adhesion promoter. Adhesion promoting additives are used to improve the compatibility between organic and inorganic components. Suitable adhesion promoters include those sold by GE Silicones of Wilton, Conn. under the Silquest®, CoatOSil®, NXT®, XL-Pearl™ and Silcat® trademarks. Examples include the following product numbers, sold under the Silquest® trademark: A1101, A1102, A1126, A1128, A1130, A1230, A1310, A162, A174, A178, A187, A2120. For example, Silquest® A-187 is (3-glycidoxypropyl)trimethoxysilane, which is an epoxysilane adhesion promoter. Silanes sold by Degussa AG of Düsseldorf, Germany, under the Dynasylan® trademark are also suitable.
Stabilizers. Light or UV stabilizers are classified according to their mode of action: UV blockers—that act by shielding the polymer from ultraviolet light; or hindered amine light stabilizers (HALS)—that act by scavenging the radical intermediates formed in the photo-oxidation process. The compositions of the invention may, when advantageous, comprise about 0.1 to about 2 wt % of a light stabilizer, preferably about 0.5 to about 1.5%, and further comprise about 0.1 to about 4 wt % of a UV blocker, preferably about 1 to about 3%.
Light stabilizers and UV blockers sold under the Irgafos®, Irganox®, Irgastab®, Uvitex®, and Tinuvin® trademarks by from Ciba Specialty Chemicals, Tarrytown, N.Y., may be used, including product numbers 292 HP, 384-2, 400, 405, 411L, 5050, 5055, 5060, 5011, all using the Tinuvin trademark. Suitable UV blocking agents include Norbloc® 7966 (2-(2′ hydroxy-5′ methacryloxyethylphenyl)-2H-benzotriazole); Tinuvin 123 (bis-(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester); Tinuvin 99 (3-(2H-benzotriazole-2-yl) 5-(1,1-dimethyl ethyl)-4-hydroxybenzenepropanoic acid, C7-9-branched alkyl esters) Tinuvin 171 (2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methyl-phenol). Products sold under the Norbioc® trademark are available from Janssen Phannaceutica of Beerse, Belgium.
Suitable hindered amine light stabilizers (HALS) are sold by the Clariant Corporation, Charlotte, N.C., under the Hostavin® trademark, including Hostavin 845, Hostavin N20, Hostavin N24, Hostavin N30, Hostavin N391, Hostavin PR31, Hostavin ARO8, and Hostavin PR25. HALS are extremely efficient stabilizers against light-induced degradation of most polymers. They do not absorb UV radiation, but act to inhibit degradation of the polymer, thus extending its durability. Significant levels of stabilization are achieved at relatively low concentrations. The high efficiency and longevity of HALS are due to a cyclic process wherein the HALS are regenerated rather than consumed during the stabilization process. They also protect polymers from thermal degradation and can be used as the thermal stabilizers
The acrylate based curable systems of the invention are cured with convection heating or infrared radiation for 60 seconds or longer. Optional use of curing agents can increase cure rates. The use of moderate heat with free-radical curing allows the cure of much thicker coatings, as much as 150 microns, wet thickness. Ultraviolet curable systems have a wet thickness limit of about 32 microns, and specialized UV curing equipment is needed, for example a Fusion™ ultraviolet curing system, or mercury vapor arc lamps. A distinction of the present invention is that ultraviolet radiation cannot be used to cure the system at a thickness of greater than about 32 microns.
Properties of the Medium.
The viscosity of the medium is about 40,000 to 150,000 cps at a shear rate of 0.125/second; about 6,000 to 18,000 cps at shear rate of 2.5/second, and about 4,000 to 10,000 at shear rate of 25/second. Medium burn-out is approximately 98.5 to 99.5% with 0.5 to 1.5% carbon ash remaining after firing at 640 to 710° C. The weight loss on curing is generally less than 7%. Film hardness is greater than 300 grams using BYK® Gardner scratch pen. The adhesion to glass is sufficient to pass a traditional Scotch® tape test.
Each numerical range disclosed herein that is bounded by zero, has, as an alternative embodiment, a lower bound of 0.1% instead of zero. The term “comprising” provides support for “consisting essentially of” and “consisting of.” It is envisioned that an individual numerical value for a parameter, temperature, weight, percentage, etc., disclosed herein in any form, such as presented in a table, provides support for the use of such value as the endpoint of a range. A range may be bounded by two such values.
EXAMPLES
The following compositions represent exemplary embodiments of the invention. They are presented to explain the invention in more detail, and do not limit the invention.
TABLE 1
Working Examples of Acrylate Based Mediums.
Example No.
Component/(wt %)
1
2
3
4
SR306
32.8
0.0
20.0
32.8
Elvacite 2043 (80% in SR306)
40.0
40.8
40.0
40.0
6X037 acrylated Polyester/Urethane
10.0
17.0
16.6
10.0
co-polymer
Elvacite 2043 (80% in Texanol)
5.0
2.0
5.0
5.0
Tetrafunctional polyester
4.0
1.0
0
0
SR339
4.0
4.0
2.0
4.0
SR 9209 A
0
20.0
0
0
SR454
0
15.0
12.0
0
Craynor CN-111
4.0
4.0
2.0
4.0
Modaflow ® AQ3000 flow agent
0.2
0.2
0.3
0.2
Peroxide curing agent
2.0
2.0
2.0
2.0
Metal drier
0
0
0.1
0
TABLE 2
Further Working Examples of Acrylate Based Mediums
Composition in wt %
Heat and photo cure
Heat cure
SR415
37.8
38.4
Tetraglyme or higlyme
37.8
38.4
SR306
15.1
15.4
Elvacite 2043
3.8
3.8
Dibenzoyl peroxide
1.7
0
Disperbyk 111
2.4
2.2
BYK 356
0.9
1.0
Isostearic acid
0.5
0.7
SR306 is triproplylene glycol diacrylate; SR 339 is 2-phenoxyethyl acrylate; SR 9209A is alkoxylated diacrylate; SR 454 is ethoxylated trimethylol propane triacrylate; SR 415 is Ethoxylated (20) Trimethylolpropane Triacrylate. The SR-named constituents are available from Sartomer Europe, Paris, France. Craynor CN-111 is epoxidized soybean oil acrylate, available from Cray Valley, Paris, France.
A distinct advantage of the medium of the invention is its low level of volatile organic compounds (VOCs) released during heating and curing. Prior art VOC levels at a 125 micron wet film thickness (solvent-based mediums dried using IR or convection heating), such as 70% diproylene glycol, 20% glycol ether DB (diethylene glycol, monobutyl ether), 6% Klucel™ E resin, and 4% Aerosol™ OT surfactant will release 450 to 500 g/liter when dried at 175 to 185° C. for 3 minutes. The formulations of the invention described herein, when applied at 125 microns wet thickness, release only 114 to 120 g/liter of VOCs. Formulations with the examples given in Table 2 resulted in 85 g and 66 g per liter respectively.
Other prior art formulas containing higher amounts of solvent and lower amounts of resin include, for example: 75% glycol ether DB, 22% propylene glycol, 2% Klucel E™ resin, 1% Aerosol™ OT surfactant. Such a formulation will release 500 to 550 g/liter of VOCs.
The invention allows for screen printing applications (20 to 40 microns thick) as well as roll coat applications (120 to 175 microns thick) onto glass and/or ceramic substrates while minimizing the release of volatile organic compounds during application and use of coating products.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and illustrative example shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general invention concept as defined by the appended claims and their equivalents.
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An acrylate-based curable printing medium is disclosed. Acrylates, in the form of monomers, dimers, trimers and oligomers, as well as resins, form an interpenetrating polymer network by crosslinking, which is effected by heat, and optionally peroxide curing agents. Formulations can be tailored to achieve desired properties of the cured polymer including film hardness, burnout properties, and adhesion to glass. Such properties are adjusted by manipulating the relative proportions of the acrylic monomers, oligomers and resins that are used as a ceramic medium or vehicle.
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FIELD OF THE INVENTION
Embodiments of the invention relate to a system for managing threads.
GENERAL BACKGROUND
In computing systems, such as web servers or application servers, threads are used to handle transaction requests. A “thread” is generally defined as a sequence of instructions that, when executed, perform a task. Multiple threads may be processed concurrently to perform different tasks such as those tasks necessary to collectively handle a transaction request. A “transaction request” is a message transmitted over a network that indicates what kind of service is requested. For instance, the message may request to browse some data contained in a database. In order to service the request, the recipient initiates a particular task that corresponds to the nature of the requested task.
One problem associated with conventional computing systems is that a significant amount of processing time is spent by a central processing unit (CPU) on thread management. In general, “thread management” involves management of queues, synchronizing, waking up and putting-to-sleep threads, context switches and many other known functions. For instance, in systems with a very high thread count, on the order of thousands for example, operations of the systems can be bogged down simply due to thread management and overhead, namely the time it takes to process threads.
A proposed solution of reducing the high processing demands is to preclude the use of a large number of threads to handle transaction requests. Rather, single threads or a few threads may be configured to handle such requests. This leads to poor system scalability.
Currently, there are computing systems that have threading control built into the CPU such as a CRAY® MTA™ computer. However, these systems suffer from a number of disadvantages. First, only a maximum of 128 threads are supported per CPU. As a result, support of a larger thread count would need to be implemented in software. Second, integrating circuitry to support up to 128 threads occupies a significant amount of silicon real estate, and thereby, increases the overall costs for the CPU. Third, the threading control hardware of conventional computing systems is stand-alone and is not connected to the rest of the system (e.g., input/output “I/O” circuitry). Since this hardware does not have the proper interface with the rest of the system, true automatic thread management is not provided (e.g., waking up a thread when a “file read” operation that the thread has been waiting on is completed).
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may best be understood by referring to the following description and accompanying drawings that are used to illustrate embodiments of the invention.
FIG. 1 is a first exemplary diagram of a computing system featuring a thread control processor (TCP);
FIG. 2 is a second exemplary diagram of a computing system featuring the TCP; and
FIG. 3 is an exemplary block diagram illustrating operations of the TCP.
DETAILED DESCRIPTION
Certain embodiments of the invention relate to a computing system, co-processor and method for managing threads. For one embodiment of the invention, thread management overhead is off-loaded to specialized hardware implemented in circuitry proximate to a system processor. In another embodiment of the invention, thread management is integrated into the system processor.
Certain details are set forth below in order to provide a thorough understanding of various embodiments of the invention, albeit the invention may be practiced through many embodiments other that those illustrated. Well-known circuitry and operations are not set forth in detail in order to avoid unnecessarily obscuring this description.
Herein, a “computing system” may generally be considered as hardware, software, firmware or any combination thereof that is configured to process transaction requests. Some illustrative examples of a computing system include a server (e.g., web server or application server), a set-top box and the like.
A “thread” is a sequence instructions that, when executed, perform one or more functions or tasks. The threads may be stored in a processor-readable medium, which is any medium that can store or transfer information. Examples of “processor-readable medium” include, but are not limited or restricted to a programmable electronic circuit, a semiconductor memory device, a volatile memory (e.g., random access memory, etc.), a non-volatile memory (e.g., read-only memory, flash memory, etc.), a floppy diskette, an optical disk such as a compact disk (CD) or digital versatile disc (DVD), a hard drive disk, or any type of communication link.
Referring to FIG. 1 , an exemplary diagram of a computing system 100 is shown. The computing system 100 comprises a processor unit 110 , a thread control processor (TCP) 120 , a system memory 130 , synchronization primitives 140 and one or more I/O subsystems 150 .
As shown in this embodiment of the invention, processor unit 110 comprises one or more (M) processors 112 1 – 112 M . The particular number “M” of processors forming processor unit 110 is optimized on the basis cost versus performance. For simplicity in the present description, two processors 112 1 and 112 M are illustrated. An operating system (O/S) 114 is accessible to processors 112 1 and 112 M and uses a driver 116 to communicate with TCP 120 .
Each “processor” represents a central processing unit (CPU) of any type of architecture, such as complex instruction set computers (CISC), reduced instruction set computers (RISC), very long instruction word (VLIW), or hybrid architecture. Of course, a processor may be implemented as an application specific integrated circuit (ASIC), a digital signal processor, a state machine, or the like.
As shown in FIG. 1 , processor unit 110 is in communication with TCP 120 . TCP 120 may be implemented as (i) a co-processor (as shown) separately positioned on a circuit board featuring processor unit 110 or (ii) additional circuitry implemented either on the same integrated circuit chip of a processor (e.g., processor 112 1 ) or on a separate integrated circuit chip within the same processor package (see FIG. 2 ).
TCP 120 is responsible for maintaining threads (e.g., JAVA® threads) operating within the computing system 100 . For instance, TCP 120 performs wake-up and put-to-sleep, thread scheduling, event notification and other miscellaneous tasks such as queue management, priority computation and other like functions. Interconnects 160 and 170 are provided from the TCP 120 to synchronization primitives 140 and I/O subsystems 150 , respectively.
For this embodiment of the invention, I/O subsystems 150 comprise networking network interface controllers (NICs) 152 and disk controllers 154 . These I/O devices may be configured to communicate with TCP 120 .
Herein, embodied in hardware or software, synchronization primitives 140 include a mutual exclusion object (Mutex) 142 and/or a Semaphore 144 . Both of these primitives are responsible for coordinating the usage of shared resources such as files stored in system memory 130 or operating system (OS) routines.
In general, Mutex 142 is a program object created to enable the sharing of the same resource by multiple threads. Typically, when a multi-threaded program is commenced, it creates a mutex for each selected resource. Thereafter, when a thread accesses a resource, a corresponding mutex is configured to indicate that the resource is unavailable. Once the thread has concluded its use of the resource, the mutex is unlocked to allow another thread access to the resource.
Similar in purpose to Mutex 142 , Semaphore 144 is a variable with a value that indicates the status of a shared operating system (OS) resource. Hence, Semaphore 144 is normally located in designated place in operating system (or kernel) storage.
Referring now to FIG. 3 , an exemplary block diagram illustrating operations of the TCP 120 is shown. The TCP 120 manages all active threads in the computing system 100 . For simplicity in illustration, eight (8) threads 200 , 210 , 220 , 230 , 240 , 250 , 260 and 270 (generally referred to as “thread(s) 280 ”) are illustrated.
In practice, however, thousands of threads may be utilized. The threads may be in either a RUN state, a WAIT state or a SLEEP state. For instance, threads existing in a RUN state and loaded in processor unit 110 include threads 200 and 210 .
Other threads may be existing in a WAIT state such as threads 220 and 230 waiting on an I/O event within any of the I/O subsystems 150 . Hence, the TCP 120 supports automatic event notification, which allows signals to notify the TCP 120 about I/O events such as completion of a file read operation, completion of transmission of a message over a network via NIC and the like.
Also, threads 240 , 250 and 260 may also exist in a WAIT state by waiting on synchronization primitives such as Mutex 142 1 , Mutex 142 2 and/or Semaphore 144 1 . Alternatively, a thread such as thread 270 may simply be in a SLEEP state.
As indicated upon, any thread 280 is placed in a RUN state when one of a number of conditions is satisfied. For instance, a thread 280 is ready-to-run when an I/O event that the thread is waiting on is completed. Alternatively, a thread 280 is ready-to-run when a synchronization primitive 140 that the thread 280 is waiting on is triggered. Yet another example is that a thread 280 is ready-to-run when it is awoken from a SLEEP state. The TCP 120 selects threads in a RUN state (i.e., ready-to-run threads) and provides them to one of the available processor 112 1 – 112 M in the processor unit 110 for execution.
In case of multiple threads in a RUN state being available, a priority-based scheduler (not shown) can be used to select one of the threads based on the chosen priority rules. Other scheduling algorithms such as the well-known round-robin technique can be used. Threads are placed into a SLEEP state when either time quanta expires or threads request an I/O operation from an I/O device.
In general, TCP 120 can support multiple threading models. For example, JAVA® Threads or native operating system threads operate in accordance with embodiments of the invention. However, JAVA® threads are one preferred target for the TCP 120 because of their widespread use in current systems.
In an embodiment where the TCP 120 is a separate co-processor, the TCP 120 may reside on a circuit board. Lower cost is enabled since the separate processor can use older technology and support a high number of threads. Thus, for the embodiment of FIG. 1 , thread management hardware can be coupled directly to each of the I/O subsystems 150 and enable automatic event notification to threads such as completion of a file read operation. In contrast, traditional threading control hardware deals with threading control only.
While the invention has been described in terms of various embodiments, the invention should not limited to only those embodiments described, but can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative instead of limiting.
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A system for managing threads to handle transaction requests connected to input/output (I/O) subsystems to enable notification to threads to complete operations.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to an apparatus for feeding animals with a feedstuff, in particular with a liquid feedstuff, the constituents of which or which is guided or processable in at least one component and is suppliable to an output device.
[0002] Automatic feeders are known and on the market in a large number of forms and embodiments. Reference is made here in particular to DE 296 06 172.7 U or DE 296 03 702.8 U.
[0003] In these automatic feeders, a feedstuff for, for example, calves is mixed up usually from milk powder and then supplied to a point of use via a corresponding supply line. This point of use may be a bowl, but in particular also a teat.
[0004] This in particular liquid feedstuff does not generally pass immediately to the point of use from the automatic feeder, but only when it is required, i.e. when for example a calf wishes to drink. This means that this feed has to be left in the automatic feeder even for relatively long periods of time, in which case its temperature can drop in winter and rise in summer. Both of these can be undesired, and therefore for example DE 196 04 199 and DE 198 45 186 propose heating the container, in which the feedstuff is prepared, in the automatic feeder. However, this heating is insufficient, since feedstuff which is not temperature-controlled is already present in the component and also in the output device. In other words, colder feedstuff is located in the component, or output device, in the winter and possibly too warm feedstuff is located there in the summer. Especially young animals perceive this as unpleasant.
[0005] It is the object of the present invention to develop an apparatus of the abovementioned type, in which the unpleasant temperature differences are eliminated.
SUMMARY OF THE INVENTION
[0006] The object is achieved by an apparatus of the abovementioned type, in which the component and/or the output device is/are temperature-controllable.
[0007] Firstly, it is of course possible to provide the component and/or output device with a heating device, to irradiate it/them with heat or to temperature-control materials in the component and/or in the output device by corresponding irradiation or by chemical or physical processes, or to stimulate these materials to change temperature. Primarily and preferably, the components and/or output device itself are intended to be configured in a temperature-controllable manner, i.e. no additional heating devices or insulation devices are intended to be necessary.
[0008] The invention relates firstly to the component, specifically any kind of component, regardless of how it is configured. As a rule, the component should be tubular, but the invention is not limited thereto. No limits are intended to be placed on the output device, either. Generally, it is a teat, but the output device may also be in the form of a bowl. It is also conceivable to provide the teat directly on the automatic feeder, with the result that no component would be necessary; on the other hand it is also conceivable to configure the component itself as a teat, such that in this case the component is the output device. As mentioned, many possibilities which are intended to be encompassed by the invention are conceivable here.
[0009] Temperature-control should be understood as meaning both cooling and heating. Primarily in summer months, it may be necessary to cool the feedstuff, and in winter it is more likely to need to be heated.
[0010] For the purpose of cooling and/or heating, the components and/or output device may be provided in a first embodiment with recesses in which a temperature-control medium is conveyed. It is appropriate here to provide these recesses in the component and/or output device itself. For example, these may be corresponding channels or capillaries. This is important primarily for a coolant.
[0011] It is also conceivable to integrate particles into a corresponding plastics material or to produce the plastics material from a material which reacts to particular radiation. Here, there are for example metal nanoparticles or carbon nanotubes which are integrated in the plastics material and react to ultrasound or other radiation with heat or change temperature and emit this change to the environment.
[0012] However, it is primarily envisaged for the component and/or the output device itself to be configured as a resistance heater. In the case of a resistance heater, heat is generated in that current is passed through a conductive material, suitable for the purpose, having high electrical resistance, and as a result the material heats up. For example, a suitable electrically conductive material can be introduced into that plastics material from which for example the output device or the component is produced. As a result, the latter itself becomes a resistance heater. Electrically conductive materials may be for example metal meshes, conductive particles, nano-carbon material, for example carbon nanotubes, metal particles etc. What is primarily important here is that a short-circuit between two conductive plastics materials, which would preclude resistance heating of subsequent regions, does not occur too early. In other words, the resistance heater integrated into the output device or the component must be configured such that it heats as far as possible the entire teat or the entire resistance line. Thus, a supply for current without an undesired early return is required.
[0013] In a further exemplary embodiment of the invention, the component is configured in a tubular manner and has a connection piece on which the teat is pushed. According to the invention, a resistance heater, which is in the form of a tube coil, is intended to be integrated in the tubular component. As a result, the component itself is heated and transmits the heat to the teat or the liquid present in the teat via the connection piece, or an additional tongue that engages in the teat. Instead of or in addition to this resistance heater, the component can also be surrounded by a tube coil, which conveys a heat transfer medium in itself.
[0014] According to a further exemplary embodiment of the invention, the component and/or output device can consist of two plastics regions which are substantially insulated from one another but are interconnected or merge into one another in an end region. This ensures that the current flows from an introduction point to this end region and then back in the other plastics region to a second power connection.
[0015] It is also conceivable to produce a main body of the teat or in particular a component in a tubular manner from a plurality of layers, wherein at least one outer layer and at least one inner layer are conductive and are separated from one another by at least one intermediate layer made of insulating material. In this case, the at least two electrically conductive layers are radially connected. The radial connection preferably takes place such that as large a part as possible of the output device or of the component is heated. This takes place preferably in that the live connection of two layers connected to different poles of a power source takes place at the greatest possible distance from this power source.
[0016] It is also conceivable for both the component and the output device to be produced as a whole from a conductive material. A groove or other recesses is/are then introduced into this conductive material during or after production. This recess is then filled with an insulating material and a conductor is in turn introduced into this insulating material, said conductor being connected to the conductive main body. This subsequently introduced conductive material should preferably be fitted in such that as far as possible the entire component or the entire output device is heated when current flows.
[0017] The return does not otherwise always have to take place in the component or the output device itself. The component and/or output device may be produced overall from a conductive material. In this case, a separate return line is then connected to the main body. The manner in which this return line is configured is intended to be of secondary importance, for example it may be a simple shielded copper cable.
[0018] In particular in the case of the component, it may be conceivable for distances to be bridged which signify an excessively long current path. Dangerously high voltages are necessary to heat such long components. For this reason, it may be advisable to subdivide a longer component into sections which each then have the corresponding return line at their end. In this case, it is also envisaged to configure the sections as a parallel circuit.
[0019] As a result of the setting of the voltage strength or current strength, a corresponding desired temperature can be achieved in the component and/or the output device. This can otherwise also take place in an automated manner, depending on the measurement of the outside temperature. Reference is made at this point to the fact that temperature measuring devices may be provided. These may be used for example to compare the measured temperature with the desired temperature. In this case, both temperature measuring devices in the interior of the component and/or the output device, that is to say directly in contact with the feedstuff, and temperature measuring devices which are fitted in the vicinity of the component or of the output device may be envisaged.
[0020] Furthermore, those embodiments of the invention in which the temperature measuring devices for measuring the outside temperature are arranged at a distance from the component or the output device are also intended to be encompassed by the invention. Such an arrangement may, without structural complexity, serve for example to heat the feedstuff when the temperature drops below a particular preset outside temperature.
[0021] Those embodiments which are either coolable or heatable are also intended to be encompassed by the invention. For example, such an apparatus may have capillaries which are filled with a liquid which can be heated or cooled by corresponding devices that are not intended to be defined in more detail. It may also be envisaged to equip an apparatus with capillaries for the cooling function and with conductive material to which a current is intended to be applied for the heating function.
[0022] Irrespective of the choice of devices selected for temperature-control, be these capillaries, other tube devices, conductive plastics materials, metal meshes or other devices, it may be envisaged to configure these in a manner not extending in a straight line in the axial direction but rather in a meandering manner. As a result, it is possible for the component or the output device to be heated or cooled in as uniform a manner as possible.
[0023] The invention allows not only targeted re-temperature-control of the feedstock as required, but allows errors to be established by the observation of the current flow. If, for example, the apparatus according to the invention is damaged by mice, rats, the animals to be fed or by other causes, this has effects on the current flow or the voltage in the apparatus according to the invention. A device which is not intended to be described in more detail can monitor the current flow or the voltage and establish deviations beyond a preset limit value or other irregularities, record these and optionally initiate measures, for example sending information to the animal owner, via a further device.
[0024] It is furthermore possible to use the apparatus according to the invention in order to detect whether an animal has not drunk for some time. This is possible for example in that the resistance heater is configured such that, in addition to a heating function, it also has a function of detecting a drinking animal via the detection of a change in resistance. Since the animal comes into contact with the output device with its mouth while drinking, the current flow in an output device equipped with electrically conductive material inevitably changes.
[0025] Furthermore, it is also possible to monitor the temperature of the animal and also the ambient temperature via the monitoring of the resistance heater.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Further advantages, features and details of the invention can be gathered from the following description of preferred exemplary embodiments and with reference to the drawing; in which:
[0027] FIG. 1 shows a side view of a teat according to the invention;
[0028] FIG. 2 shows a front view of the teat according to FIG. 1 ;
[0029] FIG. 3 shows a perspective view of the teat according to FIG. 1 ;
[0030] FIGS. 4 to 6 show perspective views of exemplary embodiments of in each case a part of a component according to the invention;
[0031] FIG. 7 shows a side view of a further exemplary embodiment of a teat;
[0032] FIG. 8 shows a rear view of the teat according to FIG. 7 ;
[0033] FIG. 9 shows a longitudinal section through a further exemplary embodiment of a teat on a component according to the invention.
DETAILED DESCRIPTION
[0034] According to FIGS. 1 to 3 , an output device for a feedstuff, in this case a teat 1 . 1 , consists of a main body 2 which is composed substantially of two plastics shells 2 . 1 and 2 . 2 . These two plastics shells are interconnected at the tip of the teat by a cap 3 which has an extraction opening 4 .
[0035] As can be seen in particular from FIG. 3 , the two plastics shells 2 . 1 and 2 . 2 are separated from one another by two slots 5 . 1 and 5 . 2 as far as the region of the cap 3 , wherein an insulating material, for example an insulating adhesive, is located in the slots 5 . 1 and 5 . 2 .
[0036] The way in which the invention functions is as follows.
[0037] The two plastics shells 2 . 1 and 2 . 2 and also the cap 3 consist of an electrically conductive material. A current is applied for example to the plastics shell 2 . 1 in an end region 6 . 1 of the teat 1 . 1 . Since the plastics shell 2 . 1 and 2 . 2 and also the cap 3 consist of electrically conductive plastics material, the current flows through the plastics shell 2 . 1 as far as the cap 3 , it being insulated from the plastics shell 2 . 2 by the insulating adhesive in the slots 5 . 1 and 5 . 2 .
[0038] At the tip, the current is introduced into the cap 3 and now flows via the cap 3 into the plastics shell 2 . 2 and back to an end region 6 . 2 of this second plastics shell 2 . 2 . As a result of this current flow, resistance heating occurs such that the plastics shells 2 . 1 and 2 . 2 and also the cap 3 are heated. This heat can then be transmitted to the feedstuff which is extracted through the teat 1 .
[0039] FIG. 4 shows a part of a component 7 . 1 which consists of a plurality of sections. Each section is composed of a plastics shell 8 . 1 and 8 . 2 which are in turn each separated from one another by an insulation region 9 . 1 and 9 . 2 . In this case, it is possible in the case of an only short component 7 . 1 to interconnect the two plastics shells 8 . 1 and 8 . 2 in any desired manner at an end opposite the current introduction point. To this end, for the sake of simplicity, the two plastics shells 8 . 1 and 8 . 2 at the end are short-circuited together. For example, an interruption of the two insulation regions 9 . 1 and 9 . 2 or any other desired electrical connection between the plastics shell 8 . 1 and the plastics shell 8 . 2 may be provided.
[0040] If longer regions of a component are intended to be heated, it has been found to be advisable to already interconnect sections of the component between the two ends. This takes place preferably in a parallel circuit, such that uniform heating of the component is ensured.
[0041] According to FIG. 5 , it is also envisaged for a component 7 . 2 as a whole to consist, as a tubular structure, of an electrically conductive material. A return line 10 is then assigned to one end of this component 7 . 2 , said return line consisting for example of a cable, in particular a sheathed copper cable.
[0042] In another exemplary embodiment of the invention according to FIG. 6 , the component 7 . 3 is configured as a whole in a tubular manner, wherein a tube casing consists of a plurality of layers. For example, an outer layer 11 and an inner layer 12 can consist of an electrically conductive material, wherein the two layers 11 and 12 are separated from one another by an insulating layer 13 . Here, too, it is in turn conceivable for the two conductive layers 11 and 12 to be interconnected at one end or sectionally, in order that they can form a resistance heater in this way.
[0043] In a further exemplary embodiment of the invention according to FIGS. 7 and 8 , a teat 1 . 2 is formed in a similar manner to the teat according to FIGS. 1 to 3 . However, the main body 2 is in one piece as a whole. After it has been produced, one or preferably two grooves 14 are cut into this main body, an insulation material 15 being introduced into said grooves 14 . A respective tab 16 which was left when the groove 14 was cut is then introduced as a return line into this insulation material 15 . Of course, it is also conceivable for the tab 16 to be introduced separately into the groove 14 or the insulation material 15 and to be connected at its one free end to the main body 2 .
[0044] In the case of the exemplary embodiment of an apparatus according to the invention for feeding animals, a commercially customary teat 1 . 0 is pushed onto a tubular component 7 . 4 . This tubular component 7 . 4 forms to this end a connection piece 18 which is adjoined by a flange 19 . The teat rests against this flange 19 in its use position.
[0045] According to the invention, a resistance heater 17 can be integrated into this tubular component 7 . 4 , said resistance heater 17 consisting of a corresponding metal tube coil made of resistance wire or the like. The component 7 . 4 is heated by the resistance heater 17 and transmits its heat, via the flange 19 and the connection piece 18 , to the teat 1 . 0 or to the drinking liquid present in the teat. Transmission is further improved by a tongue 20 which is integrally connected to the component 7 . 4 and transmits the heat to the liquid in the teat 1 . 0 .
[0046] Preferably, instead of—or else in addition to—the resistance heater 17 , the component 7 . 4 can also be surrounded by a tube coil 21 in which a heat transfer medium is conveyed. For example, this may be hot water. The heat is transmitted from the tube coil 21 to the component 7 . 4 by way of heat exchange.
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An apparatus for feeding animals with a feedstuff, in particular with a liquid feedstuff from an automatic feeder, wherein the feedstuff is suppliable optionally via a component ( 7.1 to 7.3 ) of an output device ( 1.1, 1.2 ), wherein the component ( 7.1 to 7.3 ) and/or the output device ( 1.1, 1.2 ) include means for temperature control.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/330,370 filed May 2, 2010, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] Embodiments of the present invention relate generally to a process and apparatus for retaining a fluid.
BACKGROUND
[0003] Providing an apparatus for loading a brush (e.g., with paint) remains an area of interest. Some existing systems have various shortcomings relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.
BRIEF DESCRIPTION OF THE FIGURES
[0004] FIG. 1 is a perspective view illustrating a bucket according to one embodiment of the present invention.
[0005] FIG. 2 is a perspective view illustrating one embodiment of a cover, which is coupled to the bucket shown in FIG. 1 .
[0006] FIG. 3 is a cross-section view illustrating the bucket and cover shown in FIG. 2 .
[0007] FIG. 4 is a perspective view illustrating the cover shown in FIG. 2 in which a window in a primary lid is opened.
[0008] FIGS. 5 and 6 are perspective and cross-section views, respectively, illustrating the bucket shown in FIG. 1 after a fluid has been poured into a primary reservoir.
[0009] FIGS. 7-9 are cross-section views illustrating an exemplary process of transferring fluid from the primary reservoir to the secondary reservoir of the bucket.
[0010] FIGS. 10 and 11 are cross-section views illustrating an exemplary process of loading an accessory with fluid from the secondary reservoir of the bucket.
DETAILED DESCRIPTION
[0011] For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
[0012] Referring to FIGS. 1-3 , a fluid-retaining assembly may, for example, include a bucket 100 and a cover 200 coupled to the bucket 100 . As discussed in greater detail below, the bucket 100 includes a plurality of reservoirs within which fluid may be retained. Moreover, the bucket 100 is configured such that fluid can be selectively transferred between reservoirs depending on, for example, the orientation of the bucket 100 . In one embodiment, the bucket 100 and cover 200 are configured to prevent or at least minimize the tendency of a fluid retained within the fluid-retaining assembly from escaping if the fluid-retaining assembly is bumped, jostled, tipped, shaken, or the like. In another embodiment, the bucket 100 and cover 200 are configured to prevent or at least minimize the tendency of odors or other vapors retained within the fluid-retaining assembly from escaping outside the fluid-retaining assembly. In yet another embodiment, the bucket 100 and cover 200 are configured to prevent or at least minimize the tendency of gases, moisture, dust or the like, outside the fluid-retaining assembly from infiltrating the interior of the fluid-retaining assembly.
[0013] As shown in FIGS. 1 and 3 , the bucket 100 includes a side wall 102 , a bottom wall 104 , a rim 106 , a ledge 108 and a partition 110 . Generally, the side wall 102 can be considered as including a lower side wall portion 102 a and an upper side wall portion 102 b . As exemplarily illustrated, an upper edge 110 a of partition 110 lies elevationally between the ledge 108 and the rim 106 . However, in other embodiments the upper edge 110 a be coplanar with, or elevationally above, the rim 106 .
[0014] Constructed as described above, the lower side wall portion 102 a , the bottom wall 104 and, optionally, the partition 110 , define a primary reservoir 112 within which a liquid can be retained. It will be appreciated that the total volume of liquid retained within the primary reservoir 112 will vary based on the dimensions of the lower side wall portion 102 a , the bottom wall 104 and, optionally, the partition 110 . Likewise, the upper side wall portion 102 b , the ledge 108 and the partition 110 , define a secondary reservoir 114 within which a liquid such can be retained. It will be appreciated that the total volume of liquid retained within the secondary reservoir 114 will vary based on the dimensions of the upper side wall portion 102 b , the ledge 108 and the partition 110 . As used herein, the term “liquid” can refer to paints, stains, washes, solvents, plasters, pastes, and the like.
[0015] As exemplarily illustrated, the partition 110 is provided as a contiguous divider. However, in other embodiments slots, holes, cutouts, or the like (collectively referred to as “apertures”) of any size and shape may be defined within the partition 110 so that the secondary reservoir 114 communicates with the remainder of the interior of the bucket 100 through the partition 110 .
[0016] One or more of the lower side wall portion 102 a , upper side wall portion 102 b , bottom wall 104 , rim 106 , ledge 108 and partition 110 may be formed of the same material or from different materials. Any of the aforementioned components of the bucket 100 can be formed from materials such as polymers (e.g., polyethylene terephthalate, high-density polyethylene, low-density polyethylene, or the like of a combination thereof), wood, metal (e.g., aluminum, steel, or the like or a combination thereof), or the like or a combination thereof. In one embodiment, one or more of the lower side wall portion 102 a , upper side wall portion 102 b , bottom wall 104 , rim 106 , ledge 108 and partition 110 may be formed as a single, integral piece. For example, the lower side wall portion 102 a , upper side wall portion 102 b , bottom wall 104 , rim 106 , ledge 108 and partition 110 can be may be formed as a single, integral structure during a polymer molding process. In another embodiment, one or more of the lower side wall portion 102 a , upper side wall portion 102 b , bottom wall 104 , rim 106 , ledge 108 and partition 110 may be formed as a discrete pieces that are coupled together (e.g., by means of adhesive, rivets, weld, screws, or the like or a combination thereof).
[0017] As shown in FIGS. 2 and 3 , the cover 200 includes a primary lid 202 and a secondary lid 204 . The primary lid 202 includes a skirt section 206 at a peripheral region thereof, and a window 208 .
[0018] The skirt section 206 is configured to be press-fit over the rim 106 of the bucket 100 , thereby enabling the cover 200 to be coupled to the bucket 100 . As exemplary illustrated, the skirt section 206 includes an outer rib 206 a and an inner rib 206 b defining a channel configured to receive the rim 106 . The outer rib 206 a may be configured to be resiliently deformable so as to accept the rim 106 upon initial contact with the rim 106 and to then partially enclose the rim 106 within the channel and couple the cover 200 to the bucket 100 . It will be appreciated, however, that the skirt section 206 may be configured in any other manner. It will also be appreciated that the cover 200 may be coupled to the bucket 100 without any skirt section 206 . For example, the cover 200 may be coupled to the bucket 100 by any suitable connection mechanism (e.g., one or more hinges, clamps, screws, adhesives, or the like or a combination thereof).
[0019] The window 208 may be located within the primary lid 202 such that the window 208 is arranged over the secondary reservoir 114 when the cover 200 is coupled to the bucket 100 . The window 208 is configured to allow one or more accessories such as a paint brush, a paint roller, a stirring rod, a sponge, an edger, a foam applicator, a texturing applicator, a cloth applicator or the like or a combination thereof, into the secondary reservoir. Although only one window 208 is illustrated, it will be appreciated that the primary lid 202 can include any number of windows 208 , in any size and at any location therein. For example, the primary lid 202 may include two windows 208 arranged over the secondary reservoir 114 . In another example, the primary lid 202 may include a window arranged over primary reservoir 112 . In yet another example, the primary lid 202 may include a window arranged over both the primary reservoir 112 and secondary reservoir 114 .
[0020] The secondary lid 204 is configured to be selectively placed in the window 208 (e.g., to “close” or seal the window 208 as exemplarily shown in FIG. 4 ), and removed from the window 208 (e.g., to “open” the window 208 as exemplarily shown in FIG. 4 ). In the illustrated embodiment, the secondary lid 204 is coupled to the primary lid 202 by a hinge 210 . It will be appreciated, however, that the secondary lid 204 may be coupled to the primary lid 202 by any suitable connection mechanism (e.g., one or more hinges, clamps, screws, adhesives, or the like or a combination thereof). In one embodiment, the secondary lid 204 may be press-fit into the window 208 . In another embodiment, the secondary lid 204 and portion of the primary lid 202 may include complementary threads so that the window 208 can be opened or closed by screwing or unscrewing the secondary lid 204 . Secondary lid 204 includes an access member (e.g., lift-handle 204 a ) that can be engaged by a user to open and close the window 208 .
[0021] One or more of the primary lid 202 , secondary lid 204 , skirt section 206 , and hinge 210 may be formed of the same material or from different materials. Any of the aforementioned components of the cover 200 can be formed from materials such as polymers (e.g., polyethylene terephthalate, high-density polyethylene, low-density polyethylene, or the like of a combination thereof), wood, metal (e.g., aluminum, steel, or the like or a combination thereof), or the like or a combination thereof. In one embodiment, one or more of the primary lid 202 , secondary lid 204 , skirt section 206 , and hinge 210 may be formed as a single, integral piece. For example, the skirt section 206 may be formed from the same material as the remainder of the primary lid 202 . Additionally, the hinge 210 may be formed from the same material as the primary lid 202 and from the same material as the secondary lid 204 . In another embodiment, one or more of the primary lid 202 , secondary lid 204 , skirt section 206 , and hinge 210 may be formed as a discrete pieces that are coupled together (e.g., by means of adhesive, rivets, weld, screws, or the like or a combination thereof).
[0022] As mentioned above, the primary reservoir 112 is configured to retain a fluid. In one embodiment, and with reference to FIG. 5 , a fluid such as fluid 500 may be introduced (e.g., poured) into the primary reservoir 112 by first ensuring that the cover 200 is removed from the bucket 100 (or does not otherwise obstruct a path along which the fluid is introduced into the primary reservoir) and pouring the fluid 500 from a height above the rim 106 into the primary reservoir 112 . As shown, the surface of the liquid 500 retained is elevationally below the upper edge 110 a of partition 110 . It will also be appreciated that the surface of the liquid 500 retained may be level with the upper edge 110 a of partition 110 . In another embodiment, fluid 500 can be introduced into the primary reservoir 112 even after the surface of the fluid 500 is level with the upper edge 110 a of partition 110 . In such an embodiment, the fluid 500 would then spill into the secondary reservoir 114 . After introducing fluid 500 into the primary reservoir 112 , the cover 200 may be coupled to the bucket 100 , as shown in FIG. 6 .
[0023] An exemplary process of transferring fluid from the primary reservoir 112 to the secondary reservoir 114 of the bucket 100 will now be discussed with respect to FIGS. 7-9 .
[0024] After introducing fluid 500 into the primary reservoir 112 as shown in FIGS. 5 and 6 , the fluid 500 may be transferred into the secondary reservoir 114 first by tilting the bucket 100 , as exemplarily shown in FIG. 7 . As shown, fluid 500 flows from the primary reservoir 112 , over the partition 110 and into the secondary reservoir 114 when the bucket 100 is tilted at a sufficient angle θ. The magnitude of angle θ may depend on, among other things, the height of the lower side wall portion 102 a , the width of the primary reservoir 112 , and the height of the partition 110 . Depending on the angle θ, the bucket 100 can be tilted for any desired amount of time such that a desired amount of fluid 500 is transferred into the secondary reservoir 114 .
[0025] In the illustrated embodiment, the cover 200 is coupled to the bucket 100 , and the window 208 is closed by the secondary lid 204 , to minimize or prevent fluid from spilling out of the bucket. In another embodiment, however, the cover 200 is not coupled to the bucket 100 . In yet another embodiment, the cover 200 is coupled to the bucket 100 but the window 208 is open.
[0026] Referring to FIGS. 8 and 9 , the bucket 100 is brought to a resting position (e.g., with the bottom wall resting on a support surface such as a floor) after a desired amount of fluid 500 is transferred into and retained within the secondary reservoir 114 . Fluid retained within the secondary reservoir 114 is identified at 500 a . Fluid remaining within the primary reservoir 112 is identified at 500 b . In the event that the total volume of fluid flowing over the partition 110 during the aforementioned fluid transfer step exceeds the volume of the secondary reservoir 114 , some fluid 500 c may fall back into the primary reservoir 112 when the bucket 100 is brought to the resting position, as shown in FIG. 8 .
[0027] An exemplary process of loading an accessory with fluid from the secondary reservoir 114 will now be discussed with respect to FIGS. 10 and 11 .
[0028] After fluid 500 a is retained within the secondary reservoir 114 as shown in FIG. 9 , the window 208 in the primary lid 202 may be opened by a user as shown in FIG. 10 . In one embodiment, the window 208 is opened by rotating the secondary lid 204 about the hinge 210 upon engaging the access member 204 a . Subsequently, an accessory 10 (e.g., a paint brush) may be inserted through the window 208 and into the secondary reservoir 114 and be loaded with fluid 500 a . After loading the accessory 10 , the window 208 may be closed or may be left open until, for example, use of the fluid and accessory are no longer necessary (e.g., a paint job is complete). If the height of fluid 500 a within the secondary reservoir 114 becomes too low, the aforementioned process of transferring fluid from the primary reservoir 112 to the secondary reservoir 114 may be repeated as many times as necessary. If the primary reservoir 112 becomes depleted of fluid 500 a , fluid may be re-introduced as described above with respect to FIGS. 5 and 6 .
[0029] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment(s), but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary.
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In one embodiment, a bucket is described as including a primary reservoir and a secondary reservoir. A bottom of the secondary reservoir is located at a corresponding elevation between a top and a bottom of the secondary reservoir. The primary reservoir is disposed in selective fluid communication with the secondary reservoir.
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BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to markers for grave sites, for example, of the type that have a base that lies flush with the surface of the ground but which can be removed when the ground is to be tended. More particularly, the improved grave marker of the present invention provides a secure yet removable inscription plate to identify the grave which is very simple to manufacture and install yet which can be easily opened to facilitate access to the inscription.
In many urban cemeteries, it has been the practice for families to utilize gravesites for multiple burials due to the lack of space or the specific desires of the deceased persons. As an example, it frequently happens that a husband and wife desire to be buried in the same grave and such a practice requires that a grave marker be altered to reflect the addition of the remains of another person.
In the past, to accommodate such additions, temporary grave markers have been used which, over a period of time have been subject to deterioration or vandalism, thus rendering such grave markers inappropriate for use in cemeteries. Also, a number of grave markers of the prior art have relied on pointed posts which are inserted into the ground to hold the grave markers in place. Thus, where mowing or trimming has been required around the grave site, workers have had to pull up the grave markers which has frequently resulted in damage to the grave marker over a period of time.
The present invention has for its objects the elimination of the foregoing difficulties by providing a grave marker, preferably of stone but which may be made of other rigid material wherein the inscription can be securely held in place in the marker and yet access to the inscription can be effected quickly with a simple tool. Further, the inscription will be safe from the elements yet the entire grave marker can be removed very easily by a worker when the grave requires trimming or cleaning without damaging or exposing the inscription to the elements.
The foregoing and other advantages will become apparent as consideration is given to the following detailed description taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view in elevation of one embodiment of the grave marker of the present invention;
FIG. 2 is a view taken along lines 2--2 of FIG. 1; and
FIG. 3 is an enlarged perspective view of the inscription holder of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein like numerals designate corresponding parts throughout the several views, there is shown in FIG. 1 the grave marker 10 of the present invention. The marker 10 is preferably cast concrete and may be of a size to be easily lifted and moved about to permit surface care of the grounds. The bottom surface 12 is flat and is provided with spaced apart bores 14 which may be threaded to receive anchoring rods 16 which may be pointed at their lower ends to facilitate insertion into the ground.
The front face 18 of the marker 10 preferably slants at an angle upwardly from the base 20 to permit easy viewing of the front face 10 by a person standing on the ground in front of the marker 10. The front face 18 is formed with a recess 22, which in the illustrated embodiment is generally rectangular in shape and is of sufficient depth to receive an inscription or identification holder means 24.
The inscription holder means 24 is preferably a metal plate which fits snugly into the recess 22. As shown in FIGS. 2 and 3, the holder means 24 has upper and lower edges, 26 and 28, respectively, which are bent towards each other to define receiving channels 30 and 32, respectively. Further, it will be noted that the channel 30 is of greater depth than the lower channel 32. A transparent shield such as a rectangular piece of glass 34 is inserted into the holder means 24 with the upper edge 36 of the shield 34 received in channel 30 and the lower edge 38 of the shield 34 received in channel 32. The width of the shield 34 between edges 36 and 38 should be such that when the shield 34 is pushed into channel 30, the lower edge 38 of the shield 34 can be moved out of channel 32 and over edge 28. To hold the shield 34 in place, a curved or bent plate spring 40 of resilient metal engages the edge 36 as well as the bottom of the channel 30 so as to provide a force constantly urging the shield 34 downwardly into channel 32. The end of spring 40 engages the bottom of channel 30 by having one end thereof bent around the edge of the bottom of the channel whereby the spring 40 is held in place in the channel by engaging that portion of the plate defined by the channel as shown in FIG. 3. Between the back wall 42 and the shield 34 is inserted the grave marker 44 which should be of an appropriate size so as to fully occupy the exposed surface area behind the shield 34 so as to prevent dislodgement or misalignment of the marker 44. The back surface 42 of the holder means 24 is provided with an aperture through which a bolt or rivet 46 may be passed to secure the holder 24 in place in the recess 22 of the marker 10.
As thus far described, it will be apparent that the present invention provides a secure retainer and protector for an identification plate for the grave marker and yet one which can be easily removed for correction, changes or the like. For example, by simply sliding the shield 34 up against the spring 40, the bottom edge 38 of the shield 34 can be pivoted out over the edge 28 by a simple tool such as the end of a screwdriver to permit access to the underlying identification plate or card. Further, the overhanging edge 26 in combination with the spring urging the shield 34 against the bottom of the channel 32 will aid in preventing the ingress of water or moisture, thus protecting the name plate or card inserted behind the shield 34.
Having described the invention, it will be obvious to those skilled in this art that various modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.
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A marker for gravesites is provided with an identification holder which has two oppositely located parallel channels of different depth, the transparent shield having opposite edges received in each of the channels and a spring located in one of the channels for engaging the shield to urge the shield fully into the opposite channel.
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FIELD OF THE INVENTION
This invention relates to the input circuit to a switch mode power supply having an AC input power supply and in particular to a structure and method for preventing surges of current on turn-on of the AC input power to the switch mode power supply.
BACKGROUND OF THE INVENTION
Switch mode power supplies which take an AC power supply and convert the AC power supply to a DC voltage and current are well known. Typically, such power supplies include an AC to DC converter at the input which takes the AC power supply, rectifies the AC power and thereby converts the AC power to the DC power which then is applied to the switching regulator. The switching regulator then produces output voltage and current as required by the load. Typically, such a prior art circuit includes a rectifier. The rectifier might very well comprise a rectifying bridge as shown in FIG. 1 consisting of four diodes such as diodes D1, D2, D3 and D4 and storage capacitors such as capacitors C3 and C4 for storing the charge at a selected voltage which is then used to drive the switching regulator 14 of the switch mode power supply. The capacitors C3, C4 store the charge from the rectifier from cycle to cycle of the AC input power supply. When the switch mode power supply is turned on and an AC input voltage is suddenly applied to input terminals 11a and 11b, capacitors C3 and C4 have zero voltage across them and thus act as a short circuit. In response, a large rush of current passes through these capacitors. The full wave rectifier comprising diodes D1, D2, D3 and D4 passes a positive voltage to capacitors C3 and C4 with the result that these capacitors conduct a very large current. Typically, in the prior art a resistor R3 as shown in FIG. 1 is placed in series to input terminal 11a to limit the amount of current which can be drawn by the AC to DC input conversion stage of the switch mode power supply. Resistor R3 is typically placed in parallel with a relay RE1 which during the startup portion of the operation of the switch mode power supply is left open. When the capacitors C3 and C4 have substantially charged, relay RE1 is typically closed. If capacitor C3 and C4 are not fully charged, then a surge of current passes from input lead 11a to the full wave rectifier and the amount of this surge is inversely proportional to the size of resistor R3. Prior to the closing of relay RE1, the current on input lead 11a which passes through resistor R3 is rectified by the full wave rectifier and charges capacitor C3 and C4. Only that portion of the input voltage which is in excess of the voltage across capacitors C3 and C4 causes current to flow through resistor R3. However, capacitors C3 and C4 are continuously discharging through resistors R1 and R2. Consequently, to bring the voltage across capacitors C3 and C4 as close as possible to the intended voltage during normal steady state operation of the switch mode power supply, resistor R3 must be made quite small. At the same time, to effectively limit the input current during the initial start-up of the AC to DC conversion stage, resistor R3 should be quite large. Accordingly, there is a conflict in sizing R3 between the requirement that R3 be large to effectively limit the input current to the switch mode power supply during the initial portion of the start-up phase and be small to allow filter capacitors C3 and C4 (also called storage capacitors) to charge as closely as possible to the peak line voltage applied across input terminals 11a and 11b. In practice, the compromise between these two conflicting requirements on resistor R3 results in resistor R3 being made quite small. Typically, during normal operation the initial current surge across current limiting resistor R3 is for a sufficiently small time that R3 does not significantly heat above its design limits. However, if a load is prematurely connected to the switch mode power supply during the start-up phase or a short occurs in the switch mode power supply during the turning on of the power supply, then the initial current through resistor R3 lasts for a much longer period than originally intended and current limiting resistor R3 burns out.
SUMMARY OF THE INVENTION
In accordance with this invention, the problem of burning out the current limiting resistor connected to the input terminal of the AC to DC converter stage of the switch mode power supply is eliminated by removing this resistor and substituting a non-dissipative capacitive divider circuit which charges the filter or storage capacitors while the input relay is open. In accordance with this invention, charge pumping is employed to charge the voltage across the filter or storage capacitors to greater than the peak voltage of the AC input power source. When the output voltage across the storage or filter capacitors becomes greater than the peak input voltage, the relay connected to the input terminal is closed and the switching regulator of the switch mode power supply is then enabled to carry on its normal operations. The initial surge of current through the relay upon the closing of the relay is avoided and the circuit is not disabled should a load be prematurely applied to the switch mode power supply or a short circuit exist in the switching regulator.
This invention will be more fully understood in conjunction with the following detailed description taken together with the drawing.
DESCRIPTION OF THE DRAWING
FIG. 1 illustrates the circuit of the prior art with input current limiting resistor R3 in parallel with relay RE1;
FIG. 2 illustrates the circuit of this invention with current limiting resistor R3 eliminated and a capacitive divider circuit consisting of capacitors C1 and C2 substituted therefor.
FIG. 2a illustrates the circuit of FIG. 2 redrawn to show more the relationship between diode D4 and capacitor C2 in the voltage divider circuit comprising capacitor C1 and C2.
FIG. 3 illustrates the circuit of FIG. 2 with an additional rectifying circuit added to provide an internal source of low voltage DC power for use in operating the integrated circuit components of the switch mode power supply.
FIG. 3a illustrates the circuit of FIG. 3 redrawn to show more clearly the relationship between diode D4 and capacitor C2 in the voltage divider circuit comprising capacitor C1 and C2.
FIG. 4 illustrates the current available from the internal power supply illustrated in FIG. 3.
FIG. 5 illustrates the ramp up of voltage across storage capacitor C3 and C4 illustrated in FIGS. 2 and 3 as a function of time during the turn-on of the switch mode power supply.
FIGS. 6a, 6c and 6d waveforms illustrating the voltage across input terminals 11a and 11b, across capacitor C1, across capacitor C2 and across capacitors C3 and C4 taken together, respectively in FIG. 2.
FIGS. 7a, 7b, 7c, 7d and 7e are waveforms illustrating the voltages at nodes A, B, C, D and E, respectively in FIG. 3.
FIG. 8 shows an equivalent DC circuit for the input rectifying circuit shown in FIG. 2 and in FIG. 3.
FIG. 9a illustrates alternative ways of connecting capacitor C1 and C2 into the input rectifying circuit of a switch mode power supply.
FIG. 9b illustrates the circuitry that can be used in conjunction with FIG. 9a to provide an internal power source for the integrated circuits used in a switch mode power supply where the power source produces a negative of the voltage; and
FIG. 9c illustrates circuitry which can be used as an internal power source to generate a positive output voltage for powering the integrated circuits and other components used in a switch mode power supply.
FIG. 10a illustrates a higher power alternative to the internal power supply structure shown in FIGS. 3 and 3a.
FIG. 10b shows a special circuit for use as part of the internal source of low voltage DC power illustrated in FIGS. 3 and 3a.
DETAILED DESCRIPTION
This invention will be described in conjunction with the embodiments shown in FIGS. 2 and 3. However, it should be understood that this description is illustrative only and not limiting.
FIG. 1 illustrates a typical prior art AC to DC conversion circuit used in the input stage of a switch mode power supply. In the structure of FIG. 1, AC input power is applied at input terminals 11a and 11b. During the start-up phase of operation of the switch mode power supply, relay RE1 is open as shown and the input current passes through input limiting resistor R3 to full wave rectifier of well-known design comprising diodes D1, D2, D3 and D4 connected as shown. The rectified wave form from the diode bridge 13 is then applied to storage and filter capacitors C3 and C4 connected in series across the output terminals of the diode bridge. Resistor R1 and R2 are also connected in series across the output terminals of the diode bridge and the node between resistor R1 and R2 is connected electrically to the node between capacitors C3 and C4. Resistors R1 and R2 are bleeder resistors required by safety codes to allow the charge stored on capacitors C3 and C4 to discharge when switch mode power supply of which the input circuit is a part is turned off. Sometimes, resistors R1 and R2 can be in series with a switch which prevents current from discharging from capacitors C3 and C4 during the normal operation of the power supply. This switch allows resistors R1 and R2 to conduct when the switch mode power supply is turned off but otherwise prevents the two resistors R1 and R2 from conducting. This switch therefore prevents power from being dissipated during the normal operation of the switch mode power supply.
The load comprises the switching regulator portion 14 of the switch mode power supply. The actual load to be driven by the DC output signal of the switch mode power supply is not shown in this drawing but would be connected downstream from the switching regulator 14 in a well known manner.
During start-up operations, the input current passes through resistor R3 and then through full wave rectifying bridge 13 to charge capacitor C3 and C4. Initially, upon turning on of the power supply, the voltage across capacitors C3 and C4 is zero. Accordingly, current initially surges from a rectifying bridge across capacitors C3 and C4. Resistor R3 limits that current surge to a selected maximum value given by the maximum line voltage across terminals 11A and 11B divided by the value of resistor R3. Typically, capacitors C3 and C4 charge fairly rapidly (often in less than a second) so the maximum current surge through resistor R3 lasts only for a small period of time, typically a fraction of a second. Should, however, the switch mode power supply prematurely begin driving its load or should switching regulator 14 of the switch mode power supply have a short circuit, then capacitors C3 and C4 will charge more slowly and the maximum current surge across resistor R3 will last for a much longer period of time than resistor R3 is designed to withstand. Accordingly, resistor R3 will heat up and burn out thereby causing a failure of the switch mode power supply. In normal operation resistor R3 survives the initial turning on of the switch mode power supply, but the maximum voltage charged across capacitors C3 and C4 will be reduced from the peak voltage of the AC input source because of the presence of resistor R3. At some point during the start up operation, relay RE1 is closed in response to the voltage across capacitor C3 and C4 reaching some preselected value or to a selected time elapsing from the turn-on of the AC input power source or to some combination of these two measures. The current surge through relay RE1 upon closure depends upon how close the voltage across capacitor C3 and C4 is to the peak line voltage. The larger R3, the further the voltage across capacitors C3 and C4 is from the peak line voltage and thus the greater the current surge through relay RE1 upon its closure. Accordingly, to minimize this current surge, resistor R3 wants to be made quite small. The result is that resistor R3 becomes quite sensitive to prolonged applications of full line voltage resulting from premature loading of the switch mode power supply or from short circuits within the switch mode power supply. Consequently, resistor R3 is sensitive to burning out.
In accordance with this invention, resistor R3 is replaced by capacitors C1 and C2 connected as a voltage divider as shown in FIG. 2. Capacitors C1 and C2 are very small relative to capacitors C3 and C4. Typical values of capacitors C1 and C2 are 2.2 μf and 1.0 μf, respectively, while typical values of capacitors C3 and C4 are 4,000 μf each.
To understand the operation of the circuit of FIG. 2, it helps to refer to FIG. 2a, which is the circuit of FIG. 2 redrawn to eliminate relay RE1 and diodes D1 and D3 which are not used in the circuit until relay RE1 closes at the end of the start up. Assume that the power supply is switched on at the time the external power E applied to terminals 11a and 11b is just passing through zero volts on a positive upward swing. The voltage across capacitor C1 will follow the voltage from the power supply applied to terminals 11a and 11b with the exception that it will be about 0.7 volts less once the initial voltage applied to terminals 11a and 11b is greater than the turn-on voltage of diode D4. At that point, should the voltage applied to terminals 11a and 11b have a peak value of about 310 volts (corresponding to a 220 volt AC power source) then until the peak voltage of the first half cycle is reached, the voltage across capacitor C1 tracks, but is about 0.7 volts less than, the input power supply voltage as shown in FIGS. 6a and 6b, respectively. When the power supply voltage starts declining from its peak at time t 1 (FIG. 6a) during the first positive half cycle, the voltage on capacitor C1 likewise attempts to follow the power supply voltage. To do so, however, the charge across capacitor C1 discharges through the AC power supply. Initially during the positive slope of the AC input signal, the voltage across capacitor C2 has been limited to 0.7 volts maximum (measured positive at the node between diodes D3 and D4). Shortly after time t 1 , diode D4 is back biased to minus 0.7 volts and thus the current flowing through capacitor C1 must pass through diode D2 in the full wave rectifying bridge and through capacitors C3 and C4 thereby charging capacitors C3 and C4 positively as desired for operation of the AC to DC rectifying stage of the switching mode power supply. Because capacitor C1 is only about 2.2 μf whereas capacitors C3 and C4 are each about 4,000 μf, only a small amount of charge is deposited on capacitors C3 and C4. During the negative half cycle of the power supply beginning at time t 2 (FIG. 6a), the voltage across capacitor C1 becomes negative and the current necessary to provide the charge across capacitor C1 to generate voltage is also passed through diode D2 and capacitors C3 and C4 to further build up the positive charge on capacitors C3 and C4. Indeed, all the time that the input power supply voltage has a negative slope in the first cycle of the AC input signal (i.e., the time between t 1 and t 3 in FIG. 6a), the current flows from terminal 11b through diode D2, capacitors C3 and C4, and then through capacitor C1 to terminal 11a thereby positively charging capacitors C3 and C4. While some current also flows through bleeder resistors R1 and R2, this current is relatively small because the time constant (R1+R2)(C3C4)/C3+C4) is many times the period of one cycle of the AC input signal. In one embodiment, this time constant is 40 seconds.
At time t 3 , the input power supply voltage E changes to a positive slope and heads positive again. Capacitor C1 again is charged positively. However, the charge on capacitors C3 and C4 is unable to discharge because diode D2 becomes back biased. While a small amount of charge escapes from capacitors C3 and C4 through bleeder resistors R1 and R2, resistors R1 and R2 are 10 K ohms or larger and therefore the amount of charge leaking from capacitors C4 and C3 is relatively small. At the end at time t 3 of the negative going portion of the first cycle of the input AC signal (corresponding to the portion of the input signal shown in FIG. 6A between times t 1 and t 3 ) the voltage across capacitor C1 is not the voltage across terminals 11a and 11b but rather is the voltage across these terminals less the forward biased turn-on voltage across diode D2 (approximately 0.7 volts) plus the voltage across capacitors C3 and C4 (which during the initial cycle of AC input current is quite small (typically about 3/10ths of a volt for the particular component values selected)). The voltage on the node between capacitor C1 and diode D4 at time t 3 is about minus 1 volt beneath the voltage on the node between diodes D4 and D2 at time t 3 . This voltage is the sum of the approximately 0.7 voltage drop across diode D2 plus the approximately 0.3 volts drop across capacitor C3 and C4 taken together. Thus, when the AC input signal starts going positive at time t 3 (FIG. 6a) diode D4 will not begin conducting until the AC input signal has risen about 1.7 volts (reflecting the minus 1 volt back bias across diode D4 plus the 0.7 volt forward bias required to turn on diode D4. When diode D4 begins to conduct, current then passes from input terminal 11a through capacitor C1 through diode D4 to terminal 11b. During the remaining positive half cycle, the voltage on capacitor C1 tracks the voltage across terminals 11a and 11b but is 0.7 volts less than this voltage due to the 0.7 volts forward bias across diode D4. During this time, capacitors C3 and C4 do not further charge, but rather the voltage across capacitors C3 and C4 remains substantially constant or indeed due to the presence of bleeder resistors R1 and R2, declines slightly as shown in FIG. 6d.
In subsequent cycles of the AC input signal, during the times that this input signal has a negative slope, further current is conducted through diode D2 and capacitors C4 and C3 to further charge these capacitors. This conduction process repeats 60 times per second for an input power frequency of 60 Hertz with the result that after typically 15 to 20 seconds, the voltage across capacitors C3 and C4 becomes sufficiently positive to allow relay RE1 to be closed. This voltage is shown as a function of time in FIG. 5 and 6d. FIG. 6d shows that the voltage on capacitors C3 and C4 increases during the time period that the AC input power source has an input voltage with negative slope and then declines slightly due to the current through bleeder resistors R1 and R2 during the times that the AC input signal has a positive slope. FIG. 5 shows the voltage across capacitor C3 and C4 as a function of time. As shown in FIG. 5, typically, approximately 15 to 20 seconds are taken for the voltage across capacitor C3 and C4 to approach the final value of the voltage required on terminals 12a and 12b to drive the load 14 (FIG. 2) associated with the input rectifier of the switch mode power supply.
Note that during the negative sloped portion of each cycle of the input power supply (see FIG. 6a) no substantial current flows through capacitors C3 and C4 until the voltage from the input power supply E drops beneath the positive peak voltage by the amount of the voltage drop across diode D2 and capacitors C3 and C4. For example, as the voltage drops at time t 5 from its peak positive value, the voltage across capacitor C1 only changes due to a small current through capacitors C1 and C2, since diode D4 is now back biased off and diode D2 is also back biased. No substantial current will flow through capacitor C1 until diode D2 becomes forward biased. As the voltage on terminal 11a drops subsequent to time t 5 from its peak positive value, diode D2 will only become forward biased when the voltage on terminal 11a has dropped from its peak value by an amount equal to the forward bias turn-on voltage of diode D2 (0.7 volts) plus the voltage across capacitor C3 and C4 plus the amount diode D4 was forward biased (about 0.7 volts). Accordingly, diode D2 will only conduct following time t 5 when the voltage on input terminal 11a drops from its peak value by about 1.7 volts. At that point, diode D2 begins to conduct current which charges further capacitors C3 and C4 and capacitor C1. Actually the voltage must even drop further due to the capacitive divider effects of capacitors C1 and C2.
Referring again to FIG. 6a through 6d. As time goes on, the time necessary for diode D2 to conduct during the negative going slope of the input power supply becomes larger and larger as shown in FIG. 6c. The voltage across capacitor C2 becomes larger and larger with time reflecting the positive voltage across capacitor C3 and C4 which must be overcome before diode D2 becomes forward biased. Thus during the times between t n +4 and t n +6, for example, or t n +8 and t n +10, for example, the voltage across capacitor C2 is gradually made more negative until during a period of time just before time t n +6 or time t n +10 when diode D2 becomes forward biased and conducts additional charge to thereby recharge capacitor C3 and C4 an amount just required to meet the current drawn by bleeder resistors R1 and R2. At some point in time such as time t.sub.(n+12), relay RE1 is closed. At this point the rectifying circuit goes into its normal operation and the load 14 which consists of the switch mode power supply can be turned on and provide power to the equipment which it is designed to operate.
Once relay RE1 is turned on, capacitor C1 and C2 still are of importance to the circuit. Thus, by selecting properly the values of capacitors C1 and C2 the maximum value of voltage to which capacitor C3 and C4 can be charged is controlled. For example, if capacitor C2 was zero value (i.e., capacitor C2 was removed) and bleeder resistors R1 and R2 were also removed, then the maximum voltage across capacitor C3 and C4 would be 1.4 volts less than twice the maximum peak input supply voltage. Thus, if the input voltage E has a maximum positive value of 310 volts, then the voltage across capacitor C3 and C4 would be 620 volts minus 1.4 volts or 618.6 volts. This occurs because capacitor C2 has been removed. Then during the negative slope portion of each cycle of the output signal from generator E, the voltage generated across capacitor C1 during the positive slope portion of this cycle remains across this capacitor until the input voltage drops to a sufficient level to turn on diode D2. When capacitor C1 is charged at 310 volts and capacitor C4 and C3 are charged for example to 310 volts, this requires the input voltage on terminal 11a to drop to 0.7 volts relative to the input voltage on terminal 11b. At this point diode D2 forward biases and current is conducted through capacitor C3 and C4 and C1 thereby further charging capacitor C3 and C4 above 310 volts while discharging capacitor C1. Ultimately, the voltage across capacitor C3 and C4 will be almost double the input voltage. Thus, this circuit also functions as a charge pump. By making capacitor C2 equal to capacitor C1, the voltage across capacitor C3 and C4 would approach the peak positive voltage of the AC input signal E. However, the voltage across capacitor C3 and C4 would never reach this positive voltage because of the effect of bleeder resistors R1 and R2. Thus by making capacitor C2 somewhat smaller than capacitor C1 a charge pump effect is created which brings the voltage across C3 and C4 up to or even slightly above the peak positive voltage of the input power supply E. Then when the load 14 (the switch mode power supply) is turned on, the voltage at terminals 12a and 12b will drop to the desired DC voltage level. Once relay RE1 is closed, the full wave diode rectifying bridge comprising diodes D1, D2, D3 and D4 (FIG. 2) will provide the desired peak voltage across capacitor C3 and C4. Should, however, the current drawn by the load 14 decrease substantially, then capacitor C1 and C2 will provide a further charge pump effect which will bring the voltage across capacitor C3 and C4 above the desired output voltage on terminals 12a and 12b of the circuit.
The operation of the circuit of FIG. 2 can be understood if one assumes for a moment that capacitor C2 is not present. Then, when the input supply voltage is at its peak positive value, capacitor C1 will have across it a positive voltage equal to the peak input voltage less the 0.7 volt drop across diode D4. When the input power supply voltage on node 11a starts dropping from its peak positive value, capacitors C3 and C4 have a positive voltage across them. If, for example, capacitors C3 and C4 have been charged such that the total voltage across them is also equal to the positive line voltage (with terminal 12a being positive relative to terminal 12b), then current will not flow through diode D2 and capacitor C1 will not discharge until the input voltage applied to terminal 11a drops about 0.7 volts beneath zero. At that point, capacitor C1 will begin to discharge but the voltage across capacitors C3 and C4 will increase in response to the charge transferred to these capacitors as a result of the discharge of capacitor C1. After a number of cycles, the charge across capacitors C3 and C4 would, in fact, be such that the voltage across capacitors C4 and C3 would be just about double the peak input line voltage. The presence of capacitor C2 reduces this effect.
An advantage of this invention is that in the switching regulator portion of the power supply an integrated circuit is often used for controlling the operation of the switching regulator. This integrated circuit requires a DC power supply of typically 10 volts to 15 volts. This internal power can be obtained from the circuit of this invention simply by adding diodes and a filter capacitor to the circuit shown in FIG. 2. The structure is shown in more detail in FIG. 3. As shown in FIG. 3, this internal power supply can be generated by having the connection between C1 and C2 comprise another full wave rectifier such as a diode bridge consisting of diodes D5, D6, D7 and D8. One plate of capacitor C1 is connected to the node between diodes D6 and D8 while one plate of capacitor C2 (the plate to which this plate of C1 was previously connected) is connected to the node between diodes D5 and D7. The output terminals from this diode bridge are taken from the node between diodes D7 and D8 for the common and the node between diodes D5 and D6 for the 15 volt power supply. Filter capacitor C5 has the voltage on it controlled by zener diode Z1 which breaks down at the desired output voltage (typically 15 volts) to regulate the voltage on capacitor C5 to its proper value. The output voltage from this internal power supply circuit is taken from terminal 12C and is used to provide power for the internal operation of the power supply.
Of importance, in the preferred embodiment capacitors C1 and C2 are sized to be approximately 2.2 μf and 1.0 μf to allow these capacitors to work both with 60 cycle power and 50 cycle power. In order to allow these capacitors to work with various frequency power supplies they must be made larger than would otherwise be required. This is required because the current through the capacitors should be larger than the current through R1 and R2 to allow the capacitors to function as a voltage divider. With large current, large capacitors are required.
FIG. 8 illustrates the DC equivalent circuit for the AC input circuit of FIGS. 2 and 3. In FIG. 8, the DC voltage source has a value 2e p C2/(C1+C2). e p equals the peak voltage of the AC input signal E. C1 and C2 are the values of capacitors C1 and C2 shown in FIGS. 2, 2a and 3. The resistor R eq is an equivalent resistor whose value is given by 1/(C1+C2)f where f is the frequency of the input signal. The resistor R=R1+R2. The current through resistors R eq and R for terminals 12a and 12b open circuited is given by V=(R+R eq )I substituting from the values of each parameter given in FIG. 8 it can be shown that the current I equals [(2e p C1)/(C1+C2)]×[1/(R+1/(C1+C2)f)]. Thus it can be seen that for the frequency dependent resistance R eq to be made relatively small compared to the pure resistance R, C1 and C2 must be made adequately large. This will decrease the frequency sensitivity of the output voltage due to the presence of capacitors C1 and C2. The values of C1 and C2 were stated above to be in the microfarad range. Typically, C2 will want to be made smaller than C1. As stated above, in the preferred embodiment suitable for use with an input supply voltage of about 220 volts RMS (310 volts peak) C1 was 2.2 microfarads and C2 was 1 microfarad.
FIG. 3 illustrates the circuit of this invention in combination with diodes D5, D6, D7 and D8, capacitor C5 and zener diode D9 to produce an internal voltage source on terminal 12C for supplying relatively low voltage power for the integrated circuit components used in switch mode power supply comprising load 14. A simplified version of FIG. 3 useful in understanding the operation of this invention with this additional function is illustrated in FIG. 3a. The operation of the circuits of FIGS. 3 and 3a will be explained in conjunction with FIGS. 7a, 7b, 7c, 7d and 7e which illustrate the waveforms at nodes a, b, c, d and e, respectively. The addition of the internal power supply components to the circuit of FIG. 2 to provide the circuit of FIG. 3 has a small effect on the operation of the circuit but basically does not affect the ability of the circuit to produce the required output voltage across capacitors C3 and C4. In operation, the voltage at node e is shown in FIG. 7e to be a maximum of 15.5 volts above the voltage on terminal 12b which is the ground for the internal circuit of the switch mode power supply. The voltage on node d is illustrated in FIG. 7d and is 15.5 volts above the reference voltage on terminal 12b. The output voltage from the circuit on node c (corresponding to terminal 12a) is shown in FIG. 7c and has the same general characteristics as described above in conjunction with FIG. 6d. In operation, the AC waveform at node d when positive relative to system ground on terminal 12b forward biases diode D6 and charges storage capacitor C5. Zener diode D9 breaks down at a voltage of about 15 volts thereby requiring a voltage on node d of about 15.5 volts taking into account the forward bias drop of diode D6 before breaking down. While a diode has been described above as having a forward bias voltage drop of about 0.7 volts, this forward bias voltage drop reduces to about 0.5 volts when the diode is made quite large. In the computer model used to generate the waveforms shown in FIGS. 7d and 7e, diodes D5, D6, D7 and D8 such as to have a forward bias voltage of 0.5 volts. Accordingly, the capacitor C5 will charge to the breakdown voltage of zener diode D9. The load, represented in FIG. 3a by resistor R L , represents the resistance seen by the circuit due to the presence of the various integrated circuits and other components which are driven by this internal power supply.
During the start up of the switch mode power supply, when relay RE1 is open, the voltage from nodes e to b is as shown in FIG. 7e. Initially, during the positively sloped portions of the signal from the AC input power supply E, the voltage across capacitor C2 is about +0.2 volts since the voltage across C2 plus diode D7 must be equal to the 0.7 volt forward biased drop across diode D4. During the times that the waveform input power supply E has negative slope, the voltage from node e to terminal 12b increases slightly with time reflecting the storage of charge on capacitors C3 and C4 such that terminal 12a (node c) is biased positive relative to terminal 12b. During the first few cycles of the input waveform (corresponding to approximately the first 60 or 70 milliseconds), the voltage on node e steps up gradually during the negatively sloped portions of the input waveform reflecting the gradual storage of charge on capacitors C3 and C4.
When the charge on capacitors C3 and C4 exceeds 15.5 volts then current actually flows through diode D5 and the zener diode D9 breaks down thereby ensuring that the internal integrated circuits have a 15 volt power supply. Prior to this time the main current through zener diode D9 is supplied during the positively sloped portions of the input waveform from the AC input power supply. FIGS. 7a through 7e illustrate the waveforms at nodes a through e respectively for the first 70 milliseconds after start up and when the voltage across C3 and C4 has reached 100 volts and is still climbing.
FIG. 9a is identical in structure to the circuitry of FIG. 2 except that one plate of each of capacitors C1 and C2 is shown with a floating connection. The floating connections of 91a and 91b of capacitor C1 and C2 respectively can be connected in any combination to terminals 92a, 92b and 92c connected to the various plates of capacitor C3 and C4. Thus, for example, terminal 91a can be connected to terminal 92a and terminal 91b can be connected either to terminal 92b or 92c and the system will function substantially as described. However, alternatively, terminal 91b can be connected to either terminal 92b and terminal 91b can be connected to either of the other two terminals. Finally, both terminals 91a and 91b can be connected together and to any one of terminals 92a, 92b and 92c and the circuit will also work as described. While it might not be intuitively obvious that this is the case, in essence, C1 and C2 function as an AC capacitive voltage divider circuit across the AC input terminals 11a and 11b and the connection of other components with the low impedance at line frequency in series with these two between terminals 11a and 11b does not effect substantially the operation of components C1 and C2.
To connect in the power supply of FIG. 9b so that a negative voltage is obtained, terminal 93a is connected to any one of terminals 92a through 92c and terminal 93b is connected to any one of terminals 91b and 91a, or both such terminals. To obtain a positive power supply voltage for use in operating internal integrated circuits and components of the switch mode power supply, the circuit of FIG. 9c is used. In this case, terminal 94a is connected to any one of terminals 92a, 92b or 92c and terminal 94b is connected to either terminal 91b, 91a or both.
FIG. 10a illustrates a higher voltage alternative embodiment for the internal power supply shown in FIGS. 3 and 3a. FIG. 10b illustrates the circuit of this invention which is actually used in box 100 in FIG. 10a to convert the 70 volt DC signal generated by the internal power supply utilized in this invention to the 15 volt DC signal required to run the integrated circuits contained internally with the switch mode power supply. In FIG. 10b the values of the components and in some cases the particular power ratings of the components are listed. The circuit of FIG. 10b is utilized in a switch mode power supply made in accordance with this invention to generate an internal power supply signal of about 20 volts which is further regulated down to about 15 volts. In operation, an input signal is brought in on the input lead 101a and is used to charge capacitors C16, C17 and C19 connected in series. The charging current flows through capacitor C16, diode CR7, capacitor C17, diode CR9 and then capacitor C19. At a selected time, switch Q2 is turned on by a selected signal applied to its gate through diode CR11 from a programmable unijunction transistor Q1 thereby allowing the charged stored on capacitors C16 and C17 to transfer to capacitor C19. The voltage on capacitor C19 accordingly is approximately 20 volts but the energy stored on this capacitor is increased substantially as a result of the charge transferred to this capacitor from capacitors C16 and C17 while switch Q2 is on. This output voltage on lead 102a is then transferred to a three-terminal integrated circuit voltage regulator of standard well-known design in the arts for use in producing a regulated 15 volt output signal for use in powering the internal integrated circuits in the switch mode power supply.
Diode CR10 provides a return current path when capacitor C19 is being charged. Resistor R9 and capacitor C18 serve as a timing circuit for controlling the unijunction transistor Q1 and resistors R10, R11 and R12 serve as part of this timing circuit. Resistor R12 lets the charge on the gate of transistor Q2 slowly leak off thereby stretching the pulse supplied to the gate through diode CR11. Diode CR8 is the return path for capacitor C16 during the transfer charge to capacitor C19.
Zener diode CR12 is connected with an emitter follower transistor Q23 and resistor R14 to provide a shunt regulator which is the equivalent of a large zener diode. This zener diode regulates the output voltage on lead 102a to approximately 20 volts.
Of interest, if capacitors C1 and C2 are made larger relative to capacitors C3 and C4, then capacitors C3 and C4 will charge more quickly. The correct ratio between the capacitances of capacitors C1 and C2 will avoid overcharging capacitors C3 and C4. This correct ratio is calculated from the circuit of FIG. 8 by choosing C1 and C2 such that, at the given line frequency f, the voltage across terminals 12a and 12b is e p . The charge time constant of C3 and C4 is varied by varying the sizes of capacitors C1 and C2. The amount of overcharge of capacitors C3 and C4 can be varied by controlling the ratio of C1 to C2.
Other embodiments of this invention will be obvious to those skilled in the art in view of the above description.
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A DC switch mode power supply operating from an AC input power source typically has an input stage which includes a rectifier for rectifying the AC input power waveform to provide a DC voltage to the switch mode power supply. This rectifier includes a capacitive storage circuit for storing the DC power to be supplied to the switch mode power supply. To protect the circuit against current surges during start-up, normally an open relay is provided in parallel with a current limiting resistor. This resistor can burn out under some circumstances. This invention replaces the resistor with a capacitor divider circuit containing at least one capacitor in series between the storage capacitor and one of the terminals from the input power supply. A second capacitor can also be provided in parallel with the storage capacitor and one of the diodes of the rectifier. Another diode of the rectifier is in series with the storage capacitor. The resulting circuit limits the initial current surge to the storage capacitor and also functions as a charge pump to make possible the storage of a charge on the storage capacitor greater than the peak input voltage.
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BACKGROUND OF THE INVENTION
The production of polyurethane integral skin foams is known and is described for example, in German Auslegeschrift No. 1,196,864.
These integral skin foams are produced, for example, by charging a foamable reactive mixture based on compounds having isocyanate-reactive hydrogen atoms and polyisocyanates into a closed mold. Water and/or fluorine hydrocarbons are used as blowing agents according to the prior art. Catalysts of the type known for the production of polyurethane foams are generally also used.
By selecting suitable starting components, in particular by selecting the molecular weight and the functionality of these components, it is possible to produce flexible, as well as rigid foams and intermediate variations. The compact outer skin is achieved in this process by introducing a larger quantity of a foamable mixture into the mold than required to fill the mold cavity by free foaming. The internal wall of the mold thus generally causes cooling of the reaction mixture and condensation of the preferred organic blowing agent so that the blowing reaction ceases on the internal wall of the mold and the compact outer skin is formed.
Suitable organic blowing agents for this process include commercially-available fluorinated and/or halogenated hydrocarbons since they have sufficiently low boiling points and they do not form explosive gaseous mixtures when mixed with air. Fluorotrichloromethane and/or methylene chloride, in particular, are among the suitable blowing agents for producing polyurethane integral skin foams. Pentane or similar non-halogenated hydrocarbons are inadvisable blowing agents as expensive safety precautions are needed due to the low explosion limit of pentane-air mixtures.
Objections to both fluorotrichloromethane and methylene chloride have been expressed recently for ecological reasons, however.
It is therefore desirable to develop alternative blowing agents for the production of polyurethane foams, particularly for polyurethane integral skin foams.
As already mentioned, water may be used as a blowing agent in the polyurethane system. While free-rise polyurethane foams of excellent quality may be produced by means of this procedure, integral skin foams cannot be so produced as the surface texture, as well as the integral structure, of the foam deteriorates in comparison with molded integral skin foams using fluorine hydrocarbons as blowing agents. Another disadvantage resides in the fact that the water has to be added to the reactive mixture as an individual component immediately prior to foaming since at least partial saponification of the indispensable tin compounds (for example dibutyl-(IV)-dilaurate) occurs during the addition of suitable quantities of water to the polyol component, generally already containing the foam catalyst. This is manifested in an uncontrolled drop in activity in the already activated polyol component.
Other alternative blowing agents include compounds which decompose at temperatures above room temperature and thus give off a blowing gas. Examples include azodicarbonamide, azo-bis-isobutyronitrile or diphenylene oxide disulphohydrazine and the pyrocarbonic esters described in German Offenlegungsschrift No. 2,524,834 (U.S. Pat. No. 4,070,310) and the benzoxazines according to German Auslegeschrift No. 2,218,328 which gave off CO 2 . In order to use them as blowing agents, these compounds must have a relatively low decomposition temperature which, according to general experience, should lie well below 100° C., as the blowing agents must be effective at the beginning of the urethanization reaction. Compounds having such a low decomposition temperature, however, are obviously sensitive during storage and they require careful handling of a type which cannot be guaranteed commercially in many cases by the processors of polyurethane foams. Moreover, it is frequently characteristic of these compounds that uncontrolled decomposition might occur during storage so that they also represent a safety risk.
The use of alkane aldoximes as blowing agents is mentioned in German Patent No. 1,112,285 (British Pat. No. 908,337). The aldoximes react with NCO groups and give off CO 2 . However, the corresponding alkyl nitrile is formed simultaneously and, in the case of the examples mentioned therein, in which acetonitrile, butyronitrile or isobutyronitrile are formed when acetaldoxime, butyraldoxime or isobutyaldoxime are used as blowing agents. These compounds are all physiologically harmful and have low flash points.
SUMMARY OF THE INVENTION
It has now been found that the above-mentioned disadvantages of the prior art may be overcome by adding to the foamable mixtures according to the prior art, functional aldoximes, i.e., aldoximes containing an additional group which is reactive towards NCO groups, such as --OH, --NHR, --Ar--NH 2 , --SH, --COOH or also epoxy or carboxylic acid anhydride groups. Hydroxyl groups bonded to aliphatic or cycloaliphatic radicals, carboxyl groups and aromatically-bound amino groups are preferred as functional reactive groups, with secondary hydroxyl groups bound to aliphatic or cycloaliphatic radicals being particularly suitable.
These aldoxime reactive blowing agents may be stored in the polyol mixture for a virtually unlimited period. They do not generally cause hydrolysis of tin catalysts nor loss in activity in the already activated polyol mixture. The aldoxime blowing agents containing hydroxyl groups are particularly suitable in this case as they are completely stable toward the tin catalyst. The elimination of CO 2 (which causes the blowing effect) takes place only when polyisocyanates are mixed with the reaction mixture. The mixtures may be processed in an environmentally-acceptable and safe manner. The products formed from the reactive blowing agent during the reaction are incorporated into the polyurethane without deterioration in the polyurethane properties being observed.
This invention relates to mixtures of polyols which are liquid at room temperature with functional aldoximes as blowing agents, wherein the aldoxime groups react with polyisocyanates to liberate carbon dioxide and are simultaneously incorporated by means of the functional group thereof into the polyurethane formed. The present invention also relates to a process for the production of polyurethane foams using these incorporated reactive blowing agents as the primary blowing agent in combination with blowing agents known in polyurethane chemistry.
The process according to the invention described herein is suitable for the production of various polyurethane foams or cellular polyurethane elastomers, particularly including the production of semi-rigid and rigid polyurethane integral skin foams which are obtained by foaming the reaction mixture in closed molds.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to mixtures having aldoximes as blowing agents, comprising:
(A) a polyol or polyol mixture which is liquid below 45° C. and has an average molecular weight of from 400 to 10,000; and dissolved therein
(B) from 0.1 to 20%, by weight, preferably from 0.2 to 8%, by weight, of an incorporable aldoxime reactive blowing agent corresponding the following general formula: ##STR1## wherein X represents --OH, --COOH, --NH 2 (only aromatically-bound amino), --NH --(C 1 -C 8 ) alkyl (only aromatically-bound); preferably OH, particularly secondary OH; and
R represents an aliphatic, optionally branched, radical containing from 1 to 9 carbon atoms, preferably from 1 to 4 carbon atoms, a cycloaliphatic radical (optionally containing an oxygen atom in the ring), an aromatic radical or an araliphatic radical wherein the aliphatic radical is bound via an oxygen atom to the aromatic nucleus.
The present invention also relates to the use of mixtures of:
(A) a polyol or polyol mixture which is liquid below 45° C. and has an average molecular weight of from 400 to 10,000; and dissolved therein
(B) from 0.1 to 20%, by weight, preferably from 0.2 to 8%, by weight, of an incorporable aldoxime reactive blowing agent corresponding to the following general formula: ##STR2## for the reaction with polyisocyanates to form polyurethane foams. The polyurethane foaming reaction may also be conducted in the presence of other compounds having molecular weights of from 62 to 400, and having isocyanate-reactive hydrogen atoms;
to form polyurethane foams.
__________________________________________________________________________Examples of functional aldoxime blowing agents corresponding to theformula: ##STR3##__________________________________________________________________________include: 2-hydroxy-ethanealdoxime-(1) 2-hydroxy-propanealdoxime-(1) 3-hydroxy-butanealdoxime-(1) HO HO HO ##STR4## ##STR5## 3-hydroxy-2-methyl-butane aldoxime-(1) 3-hydroxy-2,2-dimethyl- propanealdoxime-(1) HO HO ##STR6## ##STR7## 2-hydroxy-2-methyl-propane aldoxime-(1) 3-hydroxy-2-methyl-pentanealdoxime-(1) HO HO ##STR8## ##STR9## 3-hydroxy-2,2-dimethyl-butane aldoxime-(1) 3-hydroxy-2,4-dimethyl-pen-tanealdoxime-(1) HO HO ##STR10## ##STR11## 3-hydroxy-2-isopropyl-5-methyl- hexanealdoxime-(1) 4-hydroxy-hexahydro-benz- aldoxime (1) HO HO ##STR12## ##STR13## 5-hydroxymethyl-furfur- aldoxime-(1) p-hydroxymethyl-benzald- oxime HO HO ##STR14## ##STR15## propoxylated p-hydroxy- phenyl-benzaldoxime p-amino-benzaldoxime HO H.sub.2 N ##STR16## ##STR17## 4-amino-/3-methyl-benz- aldehyde-oxime β-oximino-propionic H.sub.2 N HOOC ##STR18## ##STR19##__________________________________________________________________________
Aldoximes containing secondary hydroxy groups are particularly suitable and preferred as blowing agents for the process according to the present invention for the production of polyurethane foams. 3-hydroxy-butane-aldoxime-(1), which is also readily available commercially, is a particularly preferred compound. Free-rise polyurethane foams produced using these aldoximes containing secondary hydroxy groups have lower bulk densities than foams produced using aldoximes having primary hydroxyl groups or amino groups. Moreover, no disturbances occur in the free-rise foam when using aldoximes having secondary hydroxyl groups, while cracks and surface disturbances are sometimes observed in the finished foam when using aldoximes having primary hydroxyl or amino groups. However, the compounds may also be used advantageously for the production of integral skin foams.
Suitable polyols for the production of the mixtures of polyols containing aldoxime reactive blowing agents include various conventional polyols which have a low melting point below 45° C., but are preferably liquid. The production of the mixtures containing blowing agents is not difficult in itself and may be achieved merely by stirring the aldoxime reactive blowing agents into the polyols, dissolution being accelerated by heating to about 60° C.
However, the blowing agent may also be dissolved in a portion of the polyol or in one of the polyol components, for example in a lower molecular diol, such as butane diol-(1,4), and then be mixed with the majority of the polyol. Other agents, such as catalysts, flow agents and pigment pastes, may optionally also be introduced.
Compounds containing at least two isocyanate-reactive hydrogen atoms and generally having a molecular weight of from 62 to 10,000 are conventionally used as polyol starting components for cellular polyurethanes. Compounds containing hydroxyl groups, in particular higher molecular compounds containing from 2 to 8 hydroxyl groups (especially those having a molecular weight of from 400 to 8,000, preferably from 600 to 4,000), are preferably introduced in the predominant quantity. These include, for example, polyesters, polyethers, polythioethers, polyacetals, polycarbonates and polyester amides or mixtures thereof containing at least 2, generally from 2 to 8, but preferably from 2 to 4, hydroxyl groups, of the type known for the production of non-cellular and cellular polyurethanes. They may be mixed with other low molecular polyfunctional compounds, for example, preferably polyols, but optionally also polyamines or polyhydrazides, having molecular weights of from about 62 to 400, in order to modify the properties of the polyurethanes. However, the higher molecular weight polyols having molecular weights of from 400 to 10,000, preferably from 600 to 4,000, represent the major proportion in the polyol mixture (for example more than 60%, by weight, preferably more than 80%, by weight).
The average molecular weight of the polyol or the polyol mixture should be from 400 to 10,000 preferably from 600 to 4,000.
The preferred polyethers contain at least 2, generally from 2 to 8, preferably 2 or 3, hydroxyl groups. Such polyethers include those of the type produced, for example, by polymerization of epoxides, such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin, with themselves, for example in the presence of Friedel-Crafts catalysts, such as boron trifluoride. They may also be produced by addition of these alkoxides, preferably of ethylene oxide and propylene oxide, in a ratio of from 5:95 to 95:5, in a mixture or successively, to starting components containing reactive hydrogen atoms, such as water, ammonia, alcohols or amines. Specific examples of these starting components include propylene glycol; ethylene glycol; propylene glycol-1,3 or -1,2; trimethylol-propane; glycerin; sorbitol; 4,4'-dihydroxydiphenyl propane; aniline; ethanolamine; ethylene diamine; or the like. Sucrose polyethers, as well as formitol or formose-initiated polyethers are also suitable. Polyethers containing predominantly (up to 90%, by weight, based on all OH-groups present in the polyether) primary OH-groups are preferred in many cases. Polybutadienes containing OH-groups are also suitable.
Suitable polyesters containing hydroxyl groups include, for example, reaction products of polyhydric, preferably dihydric, and optionally also trihydric, alcohols with polybasic, preferably dibasic, carboxylic acids. The polycarboxylic acids may be aliphatic, cycloaliphatic, aromatic and/or heterocyclic and may optionally be substituted, for example, by halogen atoms and/or they may be unsaturated. Examples of such carboxylic acids and derivatives thereof include: adipic acid, sebacic acid, isophthalic acid, trimellitic acid, phthalic acid anhydride, hexahydrophthalic acid anhydride, tetrachlorophthalic acid anhydride, endomethylene tetrahydrophthalic acid anhydride, fumaric acid, dimerized or trimerized unsaturated fatty acids, optionally mixed with monomeric unsaturated fatty acids, terephthalic acid dimethyl ester and terephthalic acid-bis-glycol ester. Suitable polyhydric alcohols include, for example, ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, butylene glycol-2,3, hexamethylene diol, octamethylene diol, neopentylglycol, 1,4-bis-hydroxymethylcyclohexane, 2-methyl-1,3-propane diol, glycerin, trimethylolpropane, hexane triol-(1,2,6), trimethylol ethane, pentaerythritol, sorbitol, formitol, methyl glycoside, also diethylene glycol, triethylene glycol, tetraethylene glycol and higher polyethylene glycols, dipropylene glycol, higher propylene glycols, as well as dibutylene glycol and higher polybutylene glycols. The polyesters may contain, in part, terminal carboxyl groups. Polyesters obtained from lactones, for example ε-caprolactone, or from hydroxycarboxylic acids, for example ω-hydroxylcaproic acid, may also be used. Mixtures of at least 2 polyols or at least 2 carboxylic acids are preferably used for obtaining liquid polyester polyols.
Suitable polyacetals include, for example, the compounds which may be produced from the reaction of glycols, such as di-, tri- or tetra-ethylene glycol, 4,4'-dioxethoxydiphenyl dimethylmethane and hexane diol, with formaldehyde or trioxane.
Suitable polycarbonates containing hydroxyl groups include those known compounds which may be produced, for example by reaction of diols, such as 1,3-propane diol, 1,4-butane diol, 1,6-hexane diol, di-, tri- or tetra-ethylene glycol, with diaryl-carbonates or phosgene. The above-mentioned polyhydroxyl compounds may be modified prior to use in the polyisocyanate polyaddition process in a number of ways, for example by further esterification or etherification of already-formed segments, by reaction with a subequivalent quantity of a diisocyanate carbodiimide and subsequent reaction of the carbodiimide groups with an amine, amide, phosphite or carboxylic acid. It is also possible, if desired, to use polyhydroxyl compounds containing high molecular polyadducts and polycondensates or polymers in finely dispersed or dissolved form. Such polyhydroxyl compounds are obtained, for example, if polyaddition reactions (for example reactions between polyisocyanates and aminofunctional compounds) or polycondensation reactions (for example between formaldehyde and phenols and/or amines) are allowed to take place in situ in the above-mentioned compounds containing hydroxyl groups. Polyhydroxyl compounds modified by vinyl polymers, of the type obtained, for example, by polymerization of styrene and acrylonitrile in the presence of polyethers or polycarbonate polyols, are suitable for the process according to the present invention. When using modified polyhydroxyl compounds of the above-mentioned type as starting components in the polyisocyanate polyaddition process, polyurethane foams having significantly improved mechanical properties are formed in many cases. Mixtures of the above-mentioned hydroxyl compounds containing at least 2 isocyanate-reactive hydrogen atoms and having an average molecular weight of from 400 to 10,000, for example, mixtures of polyethers and polyesters, optionally in an additional mixture of lower molecular polyols, may obviously also be used. A more detailed enumeration of suitable polyhydroxyl compounds is given on pages 11 to 21 of German Offenlegungsschrift No. 2,854,384.
Suitable polyisocyanates include aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates of the type conventionally used for the production of polyurethane plastics.
Examples include: 1,6-hexamethylene diisocyanate; 1,12-dodecane diisocyanate; caproic acid methyl ester-2,6-diisocyanate; mixtures of the positional or stereo-isomers of 1-isocyanato-3,3,5-trimethyl-5-isocyanato-methyl-cyclohexane; 2,4- and 2,6-hexahydrotoluylene diisocyanate; hexahydro-1,3- and/or -1,4-phenylene diisocyanate; perhydro-2,4' and/or 4,4'-diphenylmethane-diisocyanate; 1,3- and 1,4-phenylene diisocyanate; 2,4- and/or 2,6-toluylene diisocyanate; diphenylmethane-2,4'- and/or -4,4'-diisocyanate and alkyl derivatives thereof; as well as naphthylene-1,5-diisocyanate. Also suitable are polyphenyl-polymethylene-polyisocyanates of the type obtained by aniline/formaldehyde condensation and subsequent phosgenation and described, for example, in British Patent Nos. 874,430 and 848,671; polyisocyanates containing carbodiimide groups; polyisocyanates containing allophanate groups or isocyanurate groups or urethane groups or biuret groups; as well as polyisocyanates produced by telomerization reactions. Other suitable polyisocyanates are enumerated in detail on pages 8 to 11 of German Offenlegungsschrift No. 2,854,384. It is also possible to use mixtures of the above-mentioned polyisocyanates.
Polyisocyanates which are available commercially are generally particularly preferred, for example 2,4- and/or 2,6-toluylene diisocyanate (TDI); polyphenyl-polymethylene-polyisocyanates of the type produced by aniline/formaldehyde condensation and phosgenation (crude MDI); and polyisocyanates containing carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups or biuret groups (modified polyisocyanates); most preferred are those modified polyisocyanates which are derived from 2,4- and/or 2,6-toluylene diisocyanate or from 4,4'- and 2,4'-diphenyl methane diisocyanate.
Other compounds containing at least 2 isocyanate-reactive hydrogen atoms and having a molecular weight of from 62 to 400 may also optionally be used as reactive components for the polyol mixtures. In this case, these also include, in particular, compounds containing hydroxyl groups, but also amino groups and/or thio groups and/or carboxyl groups and/or hydrazine end groups which are known as chain-extenders or cross-linking agents. These compounds generally contain from 2 to 8, preferably from 2 to 4 isocyanate-reactive hydrogen atoms, in particular hydroxyl groups. Mixtures of several of these compounds having a molecular weight of from 62 to 400 may also be used in this case.
Examples of such compounds include: ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, butylene glycol-2,3, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, 1,4-bis-hydroxymethyl-cyclohexane, 2-methyl-1,3-propane diol, dibromobutene diol, trimethylol propane, pentaerythritol, quinitol, sorbitol, caster oil, diethylene glycol, higher polyethylene glycols having a molecular weight of up to 400, dipropylene glycol or higher polypropylene glycols having a molecular weight of up to 400, dibutylene glycol (as well as its higher oligomers having a molecular weight of up to 400), 4,4'-dihydroxydiphenyl propane, dihydroxyethylhydroquinone, ethanolamine, diethanolamine, n-methyl diethanolamine, n-t-butyl-di-(β-hydroxypropyl)-amine, triethanolamine and 3-amino-propanol. Suitable lower molecular weight polyols also include mixtures of hydroxy aldehydes and hydroxy ketones (formose) and the polyhydric alcohols obtained therefrom by reduction (formitol). Other examples of such compounds are listed on pages 20 to 26 of German Offenlegungsschrift No. 2,854,384.
Compounds which are mono-functional towards isocyanates may also optionally be used as so-called "chain-terminators" in proportions of from 0.01 to 10%, by weight, based on polyurethane solids. Examples include monoamines, such as butyl- or dibutylamine, stearylamine, N-methyl-stearylamine, piperidine, cyclohexylamine or monohydric alcohols, such as butanol, 2-ethyl hexanol or ethylene glycol monomethylether. 0,01-4% by weight of catalysts of known types may also be used. Examples include tertiary amines, such as triethylamine, N-methylmorpholine, tetramethyl ethylene diamine, 1,4-diazabicyclo-(2,2,2)-octane, bis-(dimethylaminoalkyl)-piperazines, dimethylbenzylamine, 1,2-dimethylamidazole, mono- and bi-cyclic amidines, bis-(dialkyl amino alkyl-ether), as well as tertiary amines containing amide (preferably formamide) groups. Suitable catalysts include known Mannich bases obtained from secondary amines and aldehydes or ketones. In particular, organo metallic compounds, such as organo tin compounds are used as catalysts according to the present invention. Suitable organo tin compounds include, in addition to sulphur-containing compounds, such as di-n-octyl-tin-mercaptide, preferably tin-(II)-salts of carboxylic acids, such as tin-(II)-acetate and tin-(II)-ethyl-hexanoate, and the tin-(IV)-compounds, such as, for example, dibutyl tin dichloride, dibutyl tin diacetate, dibutyl tin dilaurate or dibutyl tin maleate. Mixtures of catalysts may be used. Other representatives of usable catalysts, as well as details about the mode of operation are described in Kunststoffhandbuch, Volume VII, edited by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966, for example on pages 96 to 102 and are enumerated in German Offenlegungsschrift No. 2,854,384.
Suitable auxiliaries and additives may also be used. Inorganic or organic substances used as blowing agents, in particular compounds, such as methylene chloride, chloroform, vinylidene chloride, monofluorotrichloromethane, chlorodichlorodifluoromethane, air, CO 2 or nitric oxide may be used. Other examples of blowing agents and details about the use thereof are described in Kunstoffhandbuch, edited by Vieweg and Hochtlen, Carl-Hanser-Verlag Munich, 1966, for example on pages 108 and 109, 453 to 455 and 507 to 510.
Surface-active additives, such as emulsifiers and foam initiators, are used in the conventional way. Suitable emulsifiers include, for example, sodium salts of castor oil sulphonates, or salts of fatty acids with amines, such as oleic acid diethylamine, also alkali metal or ammonium salts of sulphonic acids, such as dodecyl benzene sulphonic acid or dinaphthalyl methane disulphonic acid. Suitable foam stabilizers include in particular polyether siloxanes, especially those which are water-soluble. Reaction retarders, for example, substances which are acidic in reaction, such as hydrochloric acid, chloroacetic acid or organic acid halides, also known cell regulators, such as paraffins or fatty alcohols or dimethyl polysiloxanes, as well as pigments or dyes and/or known flame-proofing agents, moreover stabilizers against aging and weathering influences, plasticizers, fungistatically and/or bacteriostatically acting substances, as well as fillers may also be used. Details of these additives and auxiliaries may be obtained from German Offenlegungsschrift No. 2,854,384 on pages 26 to 31 and from the literature references quoted therein.
The polyurethane foams of this invention may be produced in a conventional way, both as free-rise foam and as molded foam. The foams may obviously also be produced by block foaming or by a known laminator process or by any other variation of foam technology.
The invention is further illustrated, but is not intended to be limited by the following examples in which all parts and percentages are by weight unless otherwise specified.
EXAMPLES
EXAMPLE 1
(a) Production of the mixture containing blowing agents.
100 parts, by weight, of a polyol mixture having an average hydroxyl number of 500 and a water content of less than 0.3%, by weight, and a viscosity at 25° C. of 2,500 mPas, consisting of:
1. 60 parts, by weight, of a polyether having an OH-number of 860, which has been obtained by addition of propylene oxide to trimethylol propane, and
2. 40, parts, by weight, of a polyether having an OH-number of 42, which has been obtained by addition of a mixture of propylene oxide and ethylene oxide (70:30 parts by weight) to a mixture of trimethylol propane and propylene glycol (molar ratio=3:1);
1.0 parts, by weight, of a conventional commercial + ) polysiloxane-polyalkylene oxide block copolymer as foam stabilizer; 3.0 parts, by weight, of N-dimethylbenzylamine and 0.5 parts, by weight, of tetramethyl guanidine as catalysts; 3.0 parts, by weight, of an amide amine oleic acid salt produced from 1 mol of 3-dimethylamino propylamine-1 and 2 mol of oleic acid as internal mold release agent; 0.2 parts, by weight, of 85% aqueous ortho-phosphoric acid as reaction retarder and 3 parts, by weight, of 3-hydroxy butanaloxime (acetaldoxime) as blowing agent become component A of the mixture according to the present invention containing reactive blowing agents.
Component B consists of a polyisocyanate which has been obtained by the phosgenation of aniline/formaldehyde condensates and has a viscosity of 130 mPas at 25° C. and a NCO content of 31%, by weight, (crude MDI).
(b) Use of the polyol mixture containing blowing agents for the production of foam.
103 parts, by weight, of Component A and 146.0 parts, by weight, of Component B are mixed intensively using a two-component metering mixing device. This foamable reaction mixture is immediately introduced into an open paper mold (size: length=250 mm, width=120 mm, height=120 mm). The following reaction times occur during the formation of this foam:
Cream time: 17 seconds after introduction of the reaction mixture into the paper mold;
Gel time: 29 seconds after introduction of the reaction mixture into the paper mold.
The foam density is 130 kg/m 3 .
EXAMPLE 2
As Example 1; 3 parts, by weight, of 2-hydroxypropanaloxime is substituted for 3 parts, by weight, of 3-hydroxy butanoloxime as the blowing agent and is added to 100 parts, by weight, of the polyol mixture of Component A.
103 parts, by weight, of Component A and 147 parts, by weight, of Component B are reacted by the method described in Example 1 and yield a free-rise foam having a density of 177 kg/m 3 .
Cream time: 19 seconds
Gel time: 31 seconds
EXAMPLE 3
As Example 1; 3 parts, by weight, of 3-hydroxy-2-methyl butanaloxime is substituted for 3 parts, by weight, of 3-hydroxy butanaloxime as the blowing agent and is added to 100 parts, by weight, of the polyol mixture of Component A. 103 parts, by weight, of Component A and 146 parts, by weight, of Component B are reacted by the method described in Example 1 and yield a free-rise foam having a density of 107 kg/m 3 .
Cream time: 17 seconds
Gel time: 32 seconds
EXAMPLE 4
As Example 3; the 3-hydroxy-2,2-dimethyl propanaloxime (primary OH-group) which is isomeric to 3-hydroxy-2-methylbutanoloxime (secondary OH-group) is used as blowing agent in Component A. The density of the resulting free-rise foam is 285 kg/m 3 .
Cream time: 19 seconds
Gel time: 29 seconds.
EXAMPLE 5
As Example 1; 4 parts, by weight, of 4-amino benzaldoxime is substituted for 3 parts, by weight, of 3-hydroxy butanoloxime as the blowing agent and is added to 100 parts, by weight, of the polyol mixture of Component A. 104 parts, by weight, of Component A and 146 parts, by weight, of Component B are reacted by the method described in Example 1 and yield a free foam having a density of 218 kg/m 3 .
Cream time: 19 seconds
Gel time: 31 seconds.
EXAMPLE 6
80 parts, by weight, of a difunctional polyether having an hydroxyl number of 28, which has been obtained by addition of propylene oxide and ethylene oxide (79:21) to propylene glycol; 12 parts, by weight, of a trifunctional polyether having a hydroxyl number of 35 and an average molecular weight of 4,800, which has been obtained by addition of propylene oxide and ethylene oxide (70:30) to trimethylol propane; 20 parts, by weight, of ethylene glycol; 2 parts, by weight, of trimethylol propane; 0.015 parts, by weight, of tin dibutyl dilaurate; 0.3 parts, by weight, of triethylene diamine and 2.6 parts, by weight, of 3-hydroxybutanaloxime as the blowing agent are mixed to form Component A.
Component B consists of a semi-prepolymer composed of bis-(4-isocyanatophenyl)-methane and dipropylene glycol having an NCO content of 22.8%, by weight. 117 parts, by weight, of Component A and 148 parts, by weight, of Component B are mixed intensively using a two-component metering mixing device. This foamable reaction mixture is immediately introduced into an open paper mold (for size, see Example 1). A cream time of 18 seconds is produced as the foam begins to form.
VARIATION
The same quantities of Components A and B are introduced, after mixing, into a plate-shaped, vertically standing die, which is adjusted to about 80° C., by means of an adjacent inlet. The plate-shaped molding (height=200 mm, width=200 mm, length=10 mm) may be removed after three minutes. The density of the resulting foam is 630 kg/m 3 and its surface hardness is 54 Shore D.
Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
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This invention relates to mixtures of polyols which are liquid at room temperature with functional aldoximes as blowing agents, wherein the aldoxime groups react with polyisocyanates to liberate carbon dioxide and are simultaneously incorporated by means of the functional group thereof into the polyurethane formed. The present invention also relates to a process for the production of polyurethane foams using these incorporated reactive blowing agents as the primary blowing agent in combination with blowing agents known in polyurethane chemistry. The process according to the invention described herein is suitable for the production of various polyurethane foams or cellular polyurethane elastomers, particularly including the production of semi-rigid and rigid polyurethane integral skin foams which are obtained by foaming the reaction mixture in closed molds.
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FIELD OF THE INVENTION
[0001] The present invention is directed to providing a backpack, typically a school bag that includes a weighing means integral thereto for the weighing thereof to prevent overburdening the student.
BACKGROUND
[0002] School children and students carry a miscellany of burdens including textbooks, packed lunches, exercise books, physical education clothing, and personal items, such as toys and games. The maximum safe weight that may be carried is a function of the size of the child and his physical health, and is also affected by the distance the child has to walk to school. As a rule of thumb, it has been stated that children should not carry more than 10% of their body weight.
[0003] It appears that back ache and lumbar problems suffered by adults can, in some cases, be attributed to carrying heavy schoolbags and other loads as a child.
[0004] Weighing a schoolbag by a parent or guardian on a domestic kitchen or bathroom scales is often not practicable. Neither is it practicable for schools to weigh the bags of all students; particularly since the allowable weight that may be carried is student specific, depending on the size and health of the student, as described hereinabove.
[0005] Preferably schoolbags should be worn as backpacks, with the weight evenly distributed over both shoulders.
[0006] WO 8404027 to Koivisto describes a bag with an integral weighing device. The bag includes strain gauge transducers that appear to be mounted between the legs and body of the bag to give a reading when the bag is on the ground. Such a setup is not suitable for backpack of the type preferred for schoolchildren.
[0007] United Kingdom Patent Number GB 2402611 to Qurshi describes a suitcase having a means for weighing its contents. It uses tension sensors, but these are coupled to the bottom of the suitcase. Again, such a setup is ideal for suitcases, but is not practicable for schoolbags.
[0008] Chinese patent number CN 1488921 to Liangxhian Li et al. titled “suitcase weighing method and self weighing type suitcase thereof” describes a suitcase whose weighing device is activated by the handle and seems to be operated by suspending the case from the handle, with the weight thereof being shown on an indicating plate. The suitcase is described as having a box body, and is not a schoolbag of the backpack variety.
[0009] CN 94202372 titled “School bag with over weigh alarm function” appears to relate to a schoolbag having an alarm if overweight. There is no English language equivalent nor is there an English language abstract. From the title thereof, it would appear that the schoolbag emits some audible alarm if over weight. There is no indication that the bag includes a weighing device that provides weight readings.
[0010] There is also a Chinese utility model number CN 1488921 to Cai Derhing, entitled “Shopping bag with spring balance.”
[0011] There is also a registered Chinese design (CN 2728280 titled “School bag having spring balance”. We have not been able to access further details. From the title, we believe the weighing means is a mechanical spring balance. It will be appreciated that mechanical spring balances are simple relatively heavy devices that have no memory functions. They are also notorious at trapping or cutting little fingers. They do not have a modern, high tech look as desired by many students, and frequently lack desired precision, accuracy and reliability. Thus they are not really appropriate for schoolbags for the modern student.
[0012] Despite the crowded prior art, there appears to be a need for a schoolbag that overcomes the disadvantages of the prior art and the present invention addresses this need.
SUMMARY OF THE INVENTION
[0013] It is an aim of the invention to provide a schoolbag having a modern high tech integral weighing device and a weighing device for retrofitting to such a schoolbag.
[0014] Accordingly, the present invention is directed to providing a backpack comprising shoulder straps, a back contacting panel and at least a first storage compartment; the backpack being characterized by a handle attached to an upper surface thereof via an electronic strain gauge mechanism coupled to a processor with a digital display, such that when the electronic strain gauge mechanism is activated, suspension of the backpack from the handle causes the weight of the backpack to be displayed on the storage display.
[0015] Optionally the handle comprises a loop having two legs, and the electronic strain gauge mechanism comprises a pair of strain gauges in parallel such that each leg of the handle is attached to a separate strain gauge.
[0016] Typically, the backpack is a schoolbag.
[0017] In preferred embodiments, the backpack further comprises an inflated base for padding the contents of the bag and for providing stability.
[0018] In preferred embodiments, the backpack further comprises inflatable cells on the back contacting panel.
[0019] In preferred embodiments, the backpack further comprises inflatable cells on the shoulder straps.
[0020] Optionally, the processor is further coupled to a clock circuit such that a clock reading may be displayed on the digital display.
[0021] Preferably the processor is coupled to a user interface including keys that enable the user to program the processor to display information that typically includes information regarding the user of the backpack, selected from the list of name, address, school, class, height, weight, telephone number and email address of the user.
BRIEF DESCRIPTION OF THE FIGURES
[0022] For a better understanding of the invention and to show how it may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings.
[0023] With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail that is necessary for a fundamental understanding of the invention; the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. In the accompanying drawings:
[0024] FIG. 1 is a schematic isometric projection of a schoolbag in accordance with one embodiment of the invention, including a digital weight display;
[0025] FIG. 2 is a rear view of the schoolbag shown in FIG. 1 showing air filled shoulder pads and padded back thereof;
[0026] FIG. 3 is a section through the padded back shown in FIG. 2 ;
[0027] FIG. 4 is a schematic section through the handle of the schoolbag, showing one arrangement of strain gauges, and
[0028] FIG. 5 is a functional block diagram of the electronic circuitry coupling the electronic weight display to the strain gauges.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] With reference now to FIG. 1 and FIG. 2 , a backpack 2 is shown from the front and back respectively. The backpack includes a plurality of pockets and compartments. Backpacks of this type are widely used as schoolbags by students and pupils of all ages. By virtue of a pair of shoulder straps 3 a , 3 b , the weight of the backpack 2 is distributed across both shoulders of the wearer, making the bag easy to carry.
[0030] School children and students use such backpacks to carry a miscellany of burdens including textbooks, packed lunches, exercise books, physical education clothing, and personal items, such as toys and games. The maximum safe weight that may be carried is a function of the size of the child and his physical health, and is also affected by the distance the child has to walk to school. As a rule of thumb, it has been stated that children should not carry more than 10% of their body weight.
[0031] The backpack 2 includes a digital display unit 6 that includes a display 8 for displaying the weight of the backpack 2 and perhaps further information, such as the time, for example. The digital display unit 6 includes a simple user interface, such as a reset key 10 , and, one or two additional keys 12 , 14 , for example.
[0032] When the backpack 2 is suspended from its handle 4 , the weight of the backpack 2 and contents thereof, are displayable on the digital display unit 8 .
[0033] It is a particular feature of the backpack 2 that the base 16 thereof include an inflated cell 18 that is typically inflated with air, but may be inflated with another fluid such as helium gas for example.
[0034] The inflated cell 18 in the base 16 serves a variety of purposes, including cushioning of contents of the backpack 2 , providing a wide flat base 16 on which the backpack 2 may be conveniently stood, and giving the illusion of lightness to the backpack 2 as a whole. Additionally, with particular reference to FIG. 2 , the backpack 2 has shoulder pads 44 a , 44 b on each shoulder strap 3 a , 3 b . The shoulder pads 44 a , 44 b are optionally air filled cells, for minimum weight and maximum conformity to the wearer. Furthermore, the back panel 20 of the backpack 2 preferably includes sealed fluid filled cells 19 for providing low weight padding.
[0035] Referring now to FIG. 3 , a typical construction for the back panel might be a plurality of cells 19 filled by a low density fluid, such as compressed air, for example. Each cell might comprise an impermeable membrane 24 , perhaps fabricated from rubber or a high quality, thick polyethylene material, for example, and coated with a fabric 26 that contacts the body of the wearer, and is thus preferably permeable to be comfortable on the skin.
[0036] Inflated cells 18 , 19 , ( 44 a , 44 b ) have other advantages than merely padding. For example, a schoolbag including such inflated cells will tend to float if inadvertently dropped into water for example. Indeed, such a bag may serve as an antidrowning device, or an impromptu lifejacket.
[0037] Referring now to FIG. 4 , a schematic section through the handle 4 and the backpack 2 is shown. The outer upholstery 28 of the schoolbag includes a rigid counter-surface 30 to which a pair of strain gauges 34 a , 34 b are coupled by some coupling means 32 through which legs 5 a , 5 b of handle 4 are attached. The strain gauges 34 a , 34 b are connected to a circuit 36 including a processor 38 that is further coupled to the digital display unit 6 ( FIG. 1 ). It will be appreciated that the specific embodiment shown, is an optional arrangement only. In one alternative embodiment, for example, the handle 4 will be fixed at both sides thereof, to a single strain gauge.
[0038] Referring to FIG. 5 , a functional block diagram of the typical electronic circuitry 36 coupling the electronic weight display 8 to the strain gauges 34 a , 34 b is shown. The electronic circuitry includes: (i) a processor 38 , to which various components are connected, including (ii) a battery 48 , for providing power, that may be a lithium button type battery, such as is widely used in watches and the like, (iii) a driver 46 coupled to the display 8 for driving the display 8 , the strain gauge(s) 34 a , 34 b , the various keys of the user interface, such as reset button 10 and clock buttons 12 , 14 and a timer 50 .
[0039] It will be appreciated that the electronic circuitry may vary somewhat. The different embodiments may have more or less keys in the user interface, and the user interface may be used to input other information, for display on display 8 if processor 38 provides appropriate support. For example, such information could usefully include essential information regarding the user of the backpack 2 such as his name and/or address and identity number, the name (and address) of his school and perhaps class, and/or telephone number and/or email address; such information being useful to identify owner (user) of a mislaid backpack. For calculating allowable loading, it may also be useful to be able to input the user's height and weight,
[0040] Although described hereinabove with reference to a schoolbag, it will be appreciated that the digital strain gauge mechanism fitted to a handle and the padded backs and straps can be applied to other types of backpacks, such as those used for physical endurance training, camping, hiking and the military.
[0041] Thus the scope of the present invention is defined by the appended claims and includes both combinations and sub combinations of the various features described hereinabove as well as variations and modifications thereof, which would occur to persons skilled in the art upon reading the foregoing description.
[0042] In the claims, the word “comprise”, and variations thereof such as “comprises”, “comprising” and the like indicate that the components listed are included, but not generally to the exclusion of other components.
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The present invention is directed to providing a backpack, typically a school bag that includes a weighing means integral thereto for the weighing thereof to prevent overburdening the student. The backpack has shoulder straps, a back contacting panel and at least one storage compartment. A handle attached to an upper surface with an electronic strain gauge mechanism coupled to a processor with a digital display such that by suspending the backpack from the handle causes the weight of the backpack to be displayed on the storage display.
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This is a continuation of U.S. patent application Ser. No. 09/105,393, filed Jun. 26, 1998 now abandoned, which is a continuation-in-part of U.S. patent application Ser. No. 08/639,782 filed Apr. 29, 1996 now U.S. Pat. No. 5,843,007.
FIELD OF THE INVENTION
The invention is related to an apparatus and method for applying varying pressure waveforms to a limb of a human patient in order to help prevent deep vein thrombosis (DVT), pulmonary embolism (PE) and death.
BACKGROUND OF THE INVENTION
Limb compression systems of the prior art apply and release pressure on a patient's extremity to augment venous blood flow and help prevent deep vein thrombosis (DVT), pulmonary embolism (PE) and death. Limb compression systems of the prior art typically include: a source of pressurized gas; one or more pneumatic sleeves for attaching to one or both of the lower limbs of a patient; and an instrument connected to the source of pressurized gas and connected to the sleeves by means of pneumatic tubing, for controlling the inflation and deflation of the sleeves and their periods of inflation and deflation. In U.S. Pat. No. 3,892,229 Taylor et al. describe an early example of one general type of limb compression system of the prior art known as an intermittent limb compression system; such systems apply pressure intermittently to each limb by inflating and deflating a single-bladder sleeve attached to the limb. In U.S. Pat. No. 4,013,069 Hasty describes an example of a second general type of limb compression system of the prior art, known as a sequential limb compression system; such systems apply pressure sequentially along the length of the limb by means of a multiple-bladder sleeve or multiple sleeves attached to the same limb which are inflated and deflated at different times. Certain intermittent and sequential limb compression systems of the prior art are designed to inflate and deflate sleeves thereby producing pressure waveforms to be applied to both limbs either simultaneously or alternately, while others are designed to produce pressure waveforms for application to one limb only.
One major concern with all pneumatic limb compression systems of the prior art is that the therapy actually delivered by these systems may vary substantially from the expected compression therapy. For example, a recent clinical study designed by one of the inventors of the present invention, and involving the most commonly used sequential pneumatic limb compression systems of the prior art, showed that the pneumatic limb compression therapy actually delivered to 49 patients following elective total hip replacement surgery varied widely from therapy expected by the operating surgeons in respect of key parameters of the therapy shown in the clinical literature to affect patient outcomes related to the incidence of deep venous thrombosis, pulmonary embolism and death. The study methodology involved continuous monitoring of the varying pressure of the compressed air in the pneumatic sleeves of these systems, permitting the values of key parameters of pneumatic compression therapy actually delivered to patients to be directly monitored throughout the prescribed period of therapy and compared to the expectations of operating surgeons. The results of this clinical study indicated that the expected therapy was not delivered to any of the 49 patients monitored: therapy was only delivered an average of 77.8 percent of the time during the expected periods of therapy; the longest interruptions of therapy in individual subjects averaged 9.3 hr; and during 99.9 percent of the expected therapy times for all 49 patients monitored in the study, values of key outcomes-related parameters of the therapy actually delivered to the patients varied by more than 10 percent from desired values. These parameters included rates of pressure rise and maximum pressures actually delivered through the sleeves. The unanticipated range of variations that was found in this clinical study between expected and delivered pneumatic compression therapy, within individual patients and across all patients, may be an important source of variations in patient outcomes in respect of the incidence of deep vein thrombosis, pulmonary embolism and death, and may be an important confounding variable in comparatively evaluating reports of those patient outcomes. The present invention addresses many of the limitations of prior-art systems that have led to such unanticipated and wide variations between the expected therapy and the therapy actually delivered to patients.
Due to errors and limitations associated with estimation of the pressure applied by a sleeve to a limb, prior-art systems have not had the capability of accurately producing a desired pressure waveform in combination with sleeves having differing designs and varying pneumatic volumes, or when sleeve application techniques vary and the resulting sleeve snugness varies, or when sleeves are applied to limbs of differing sizes, shapes and tissue characteristics. As a result, substantial variations often arise between the desired and actual pressure waveforms delivered by limb compression systems of the prior art.
Many limb compression systems of the prior art are not capable of producing a desired pressure waveform in a pneumatic sleeve attached to a limb under varying operational and clinical circumstances such as movement of the limb, movement of the sleeve relative to the limb and varying snugness of sleeve application, in part because they do not generate a signal indicative of the actual pressure in the sleeve suitable for permitting a feedback control system to produce the desired pressure waveform. Some limb compression systems known in the prior art attempt to estimate sleeve pressure in an inexpensive and convenient manner, based on a variety of apparatus and methods. These systems do not measure pressure directly in the pneumatic sleeve applied to the limb but instead estimate sleeve pressure indirectly and remotely from the sleeve. For example, in U.S. Pat. No. 5,031,604 Dye describes a system in which sleeve pressure is estimated by measuring pneumatic pressure near the instrument end of the tubing connecting the instrument to the sleeve. As another example, Arkans in U.S. Pat. No. 4,375,217 describes a system in which the static pressure in the sleeve is estimated at a location on the tubing between the instrument and the sleeve. All such apparatus and methods which estimate sleeve pressure by measuring a pneumatic pressure remotely from the sleeve suffer from a significant disadvantage, which makes them unsuitable for incorporation into an instrument for producing a desired pressure waveform in the sleeve: the accuracy of the estimates of pressure made by such systems is significantly affected by variations in the length and flow resistance of the tubing attached to the sleeve, and by variations in sleeve design, sleeve inflation volume and sleeve application technique. For example, the inventors of the present invention have determined that variables related to the design and size of the sleeve, as well as the snugness of application of the sleeve, can result in discrepancies at any instant of well over 50 percent between the remotely estimated sleeve pressure and the actual pressure in the sleeve. As a separate consideration regarding the flow resistance of the tubing employed in prior-art systems which measure pressure in this manner, it has been necessary to locate such systems close to the patient to minimize flow resistance in the tubing, resulting in unnecessary noise and clutter around the patient.
Other systems known in the prior art interrupt the flow of gas in the tubing in an effort to estimate sleeve pressure by measuring pneumatic pressure at the instrument end of the tubing under zero-flow conditions. One such system is the Jobst Athrombic Pump System 2500 (Jobst Institute Inc., Charlotte N.C.). However, estimates of sleeve pressure made in this manner cannot practically be incorporated into limb compression systems for producing pressure waveforms having large amplitudes and short cycle periods. Also, more generally, such systems suffer from the disadvantage that pressure estimates are available discontinuously and are not suitable for real-time control of the pressure in the sleeve to produce a desired pressure waveform.
Some limb compression systems of the prior art attempt to record and display the total cumulative time during which pneumatic compression therapy was delivered to a patient's limb, but do not differentiate between times when values of parameters of the delivered therapy were near the desired values for the therapy and when they were not. For example, commercially available systems such as system the Plexipulse intermittent pneumatic compression device (NuTech, San Antonio Tex.) and AirCast intermittent pneumatic compression device (Aircast Inc., Summit, N.J.) record the cumulative time that compressed air was delivered to each compression sleeve. These are typical of prior-art systems which include simple timers that record merely the cumulative time that the systems were in operation.
In U.S. Pat. No. 5,443,440 Tumey et al. describe a pneumatic limb compression system capable of recording compliance data by creating and storing the time, date and duration of each use of the system for subsequent transmission to a physician's computer. The compliance information recorded by this system contains only information relating to times when the system was operating and the cumulative duration of operation. Tumey et al. cannot and does not determine occurrences when pressure-related values of parameters of the delivered therapy matched the desired values of the parameters and occurrences when they did not.
A major limitation of Tumey et al. and other limb compression systems of the prior art is that values of key parameters of pneumatic compression therapy that are known to affect patient outcomes are not monitored and recorded. This is a serious limitation because evidence in the clinical literature shows that variations in applied pressure waveforms produce substantial variations in venous blood flow, and that delays and interruptions in the delivery of pneumatic compression therapy affect the incidence of DVT. One key parameter identified by the inventors of the present invention is the interval between successive occurrences of delivered pressure waveforms having desired values of certain waveform parameters known to affect patient outcomes, such as rate of pressure rise and maximum pressure. Because this key parameter is not monitored as therapy is delivered by prior-art systems, variations between delivered and expected therapy cannot be detected as they occur, and clinical staff and patients cannot be alerted to take corrective measures for improving therapy and patient outcomes.
Because prior-art systems do not monitor the interval between successive occurrences of delivered pressure waveforms having desired values of certain waveform parameters known to affect patient outcomes, and because such prior-art systems do not therefore have alarms to alert clinicians and patients that a maximum time interval has elapsed during which the expected therapy was not delivered to the patient, then the operator and the patient cannot adapt such systems during therapy, including for example sleeve re-application and changing certain parameters of therapy, to help assure that the prescribed and expected therapy is actually delivered to the patient throughout as much as possible of the prescribed duration of therapy.
In addition to the monitoring limitations of prior-art systems described above, prior art systems do not measure and record parameters related to the application of a desired pressure waveform, such as any differences between the actual shape of the pressure waveform produced in the pneumatic sleeve and the shape of a desired reference pressure waveform, the times during which a waveform matching a desired waveform in respect of key parameters was periodically applied, the interval between applications of waveforms matching a desired waveform and the number of cycles of the waveform which were applied.
Additionally, limb compression systems do not subsequently produce the recorded values of key outcomes-related parameters for use by physicians and others in determining the extent to which the prescribed and desired pressure waveforms were actually applied to the patient for use by third-party payors in reimbursing for therapy actually provided, and for use in improving patient outcomes by reducing variations in parameters of therapy known to produce variations in patient outcomes.
SUMMARY OF THE INVENTION
The present invention provides apparatus and a method for applying pressure to a patient's limb through a pneumatic sleeve in order to augment venous blood flow in the limb and for monitoring the applied pressure, to help prevent deep vein thrombosis, pulmonary embolism and death. More specifically, the present invention includes means for supplying a gas at a varying supply pressure, an inflatable sleeve adapted for positioning onto a limb to apply a varying pressure to the limb beneath the sleeve when inflated with the gas, pressure transducing means for measuring the pressure of gas in the inflatable sleeve, waveform parameter measurement means for measuring the value of a predetermined pressure waveform parameter, and interval determination means for producing an indication of the interval between two occurrences when the measured value of the predetermined pressure waveform parameter is near a predetermined parameter level.
In the present invention, the pressure waveform parameter can be a predetermined variation in the measured level of pressure of gas in the sleeve that augments the flow of venous blood into the limb proximal to the sleeve from the limb beneath the sleeve. Also, the sleeve of the present invention can include two ports and separate tubing connecting it to the gas supply means and the pressure transducing means so that the pressure transducing means only communicates pneumatically with the gas supply means through the sleeve.
The present invention includes means to allow an operator to select the predetermined pressure waveform parameter and the predetermined parameter level from a plurality of predefined parameters and parameter levels. Also, alarm means are included for producing an indication perceptible to the operator and the patient when the determined interval exceeds a predetermined maximum interval.
The interval determination means of the present invention can include means for measuring a number of intervals during therapy, each corresponding to the time between an occurrence when the measured value of the parameter is near the predetermined parameter level and the next occurrence when the measured value of the parameter is near the predetermined parameter level. The interval determination means can further include a clock for determining the clock times when occurrences are measured.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a pictorial representation of the preferred embodiment in a typical clinical application.
FIG. 2 is a block diagram of the preferred embodiment.
FIG. 3 are graphical representations of pressures applied to a region of a patient by the preferred embodiment
FIGS. 4, 5 , 6 and 7 are software flow charts depicting sequences of operations carried out in the preferred embodiment.
FIGS. 8 and 9 are pictorial representations of a sleeve for applying pressures to a patient's foot.
FIGS. 10 and 11 are pictorial representations of sleeve for applying pressures to a patient's calf.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The embodiment illustrated is not intended to be exhaustive or limit the invention to the precise form disclosed. It is chosen and described in order to explain the principles of the invention and its application and practical use, and thereby enable others skilled in the art to utilize the invention.
In the context of the preferred embodiment, a pressure waveform is generally considered to be a curve that represents the desired or actual amplitude of pressure in a pneumatic sleeve applied to a patient over time, and is described by a graph in rectangular coordinates whose abscissas represent times and whose ordinates represent the values of the pressure amplitude at the corresponding times. A cycle time period of the pressure waveform is generally considered to be the period of time during which one desired pressure waveform is completed. A phase of the pressure waveform is generally considered to be a portion of the pressure waveform occurring during an interval of time within the cycle time period of the pressure waveform. In the context of the preferred embodiment, periodic generation of a pressure waveform is generally considered to be the repetitive production of the pressure waveform in a pneumatic sleeve applied to a patient.
The preferred embodiment of the invention is described in three sections below: instrumentation, software and sleeves.
I. Instrumentation
FIG. 1 depicts instrument 2 connected to two inflatable sleeves, foot sleeve 4 and calf sleeve 6 . Foot sleeve 4 is suitable for applying a compressive pressure waveform to the plantar region of the foot, and is depicted applied to the right foot of a patient 8 . Foot sleeve 4 is shown in detail in FIGS. 8 and 9 and described further below. Calf sleeve 6 is suitable for applying a compressive pressure waveform to the calf and is depicted applied to the left calf of patient 8 . Calf sleeve 6 is shown in detail in FIGS. 10 and 11 and is also described below. Alternatively, other designs of sleeves, applied to other regions of the lower or upper limb, may be employed. Instrument 2 has two channels, channel “A” and channel “B”. Inflatable sleeves 4 and 6 applied to patient 8 are connected to channels “A” and “B” of instrument 2 . Instrument 2 repetitively produces a desired pressure waveform in foot sleeve 4 connected to channel “A” of instrument 2 , and repetitively produces another desired pressure waveform in calf sleeve 6 connected to channel “B” of instrument 2 , in order to augment the flow of venous blood from the portions of the limbs beneath sleeves 4 and 6 into portions of the limbs proximal to sleeves 4 and 6 . Channel “A” and channel “B” of instrument 2 operate independently, and may generate different or similar pressure waveforms, as determined by an operator.
To enable a better appreciation of the versatility of the invention, instrument 2 is depicted in FIGS. 1 and 2 with channel “A” connected to foot sleeve 4 and channel “B” connected to calf sleeve 6 , to apply pressures to the foot of the right leg and to the calf of the left leg of patient 8 , as may be desirable during a surgical procedure. In other clinical applications, channels “A” and “B” of instrument 2 may be connected to two foot sleeves for applying pressure waveforms to each foot of a patient, or to two calf sleeves for applying pressure waveforms to each calf of a patient. Alternatively, instrument 2 may be connected to only one sleeve, or two sleeves of different design applied to the same limb for applying pressure waveforms sequentially in time.
As can be seen in FIG. 1, an inflatable portion of foot sleeve 4 communicates pneumatically with channel “A” of instrument 2 by means of pneumatic connector 9 and pneumatic tubing 10 , and by means of pneumatic connector 11 and pneumatic tubing 12 . Connector 9 comprises sleeve connector 9 a non-releasably attached to foot sleeve 4 and mating tubing connector 9 b non-releasably attached to tubing 10 . Connector 11 comprises sleeve connector 11 a non-releasably attached to foot sleeve 4 and mating tubing connector 11 b non-releasably attached to tubing 12 . In the preferred embodiment connector 9 a is physically incompatible with connector 11 b and does not mate with connector 11 b. Connector 11 a is physically incompatible with connector 9 b and does not mate with connector 9 b.
An inflatable portion of calf sleeve 6 communicates pneumatically with channel “B” of instrument 2 by means of pneumatic connector 13 and pneumatic tubing 14 , and by means of pneumatic connector 15 and pneumatic tubing 16 . Connector 13 comprises sleeve connector 13 a non-releasably attached to calf sleeve 6 and mating tubing connector 13 b non-releasably attached to tubing 14 . Connector 15 comprises sleeve connector 15 a non-releasably attached to calf sleeve 6 and mating tubing connector 15 b non-releasably attached to tubing 16 . In the preferred embodiment connector 13 a is physically incompatible with connector 15 b and does not mate with connector 15 b . Connector 15 a is physically incompatible with connector 13 b and does not mate with connector 13 b.
Liquid crystal graphic display 20 shown in FIGS. 1 and 2 forms part of instrument 2 and is used to display information to the operator of instrument 2 . Display 20 is employed for the selective presentation of any of the following information as described below: (a) menus of commands for controlling instrument 2 , from which an operator may make selections; (b) parameters having values which characterize the sleeve pressure waveforms to be produced in inflatable sleeves connected to channels “A” and “B” of instrument 2 ; (c) text messages describing current alarm conditions, when alarm conditions are determined by instrument 2 ; (d) graphical and text representations of the time intervals between the production of pressure waveforms having desired predetermined parameters in inflatable sleeves connected to channels “A” and “B” of instrument 2 ; (e) messages which provide operating information to the operator.
Controls 22 shown in FIGS. 1 and 2 provide a means for an operator to control the operation of instrument 2 .
Referring the block diagram of instrument 2 depicted in FIG. 2, foot sleeve 4 communicates pneumatically with valve manifold 24 through pneumatic connector 9 and pneumatic tubing 10 . Foot sleeve 4 also communicates pneumatically with pressure transducer 26 through pneumatic connector 11 and pneumatic tubing 12 . Valve 28 and valve 30 communicate pneumatically with manifold 24 . Valve 28 , valve 30 , manifold 24 and pressure transducer 26 comprise the principal pneumatic elements of channel “A” of instrument 2 .
In the preferred embodiment valve 28 is an electrically actuated, normally closed, proportional valve and valve 30 is an electrically actuated, normally open, proportional valve. Valves 28 and 30 respond to certain valve control signals generated by microprocessor 32 . The level of the valve control signals presented to each of valves 28 and 30 by microprocessor 32 determines the degree to which valve 28 opens and the degree to which valve 30 closes. The level of the valve control signals thereby affects the pressure of gas in foot sleeve 4 by changing the rate of gas flow into and out of manifold 24 .
Pressure transducer 26 communicates pneumatically with the inflatable portion of foot sleeve 4 by means of tubing 12 and connector 11 . As shown in FIGS. 1 2 pressure transducer 26 does not communicate pneumatically with valve manifold 24 except through foot sleeve 4 . In this way, pressure transducer 26 directly and continuously measures the pressure of gas in the inflatable portion of foot sleeve 4 , irrespective of variables including the flow resistance of tubing 10 , the flow resistance of connector 9 , the design of foot sleeve 4 , the pneumatic volume of the inflatable portion of foot sleeve 4 , and the snugness of application of foot sleeve 4 to the limb of patient 8 . Pressure transducer 26 is electrically connected to an analog to digital converter (ADC) input of microprocessor 32 and generates a channel “A” sleeve pressure signal, the level of which is representative of the pressure of gas in foot sleeve 4 .
Valve 28 communicates pneumatically with manifold 24 and through tubing 34 to gas pressure reservoir 36 , a sealed pneumatic chamber having a fixed volume of 750 ml. When activated valve 28 permits the flow of gas from reservoir 36 to manifold 24 and therefrom supplies pressurized gas through tubing 10 and connector 9 to the inflatable portion of foot sleeve 4 . Valve 30 pneumatically connects manifold 24 to atmosphere, allowing a controlled reduction of pressure from foot sleeve 4 .
Valve 38 , valve 40 , manifold 42 and pressure transducer 44 comprise the principal pneumatic elements of channel “B” of instrument 2 , and are configured as shown in FIG. 2 and described below. Calf sleeve 6 communicates pneumatically with valve manifold 42 through pneumatic connector 13 and pneumatic tubing 14 . Calf sleeve 6 also communicates pneumatically with pressure transducer 44 through pneumatic connector 15 and pneumatic tubing 16 .
Valve 38 and valve 40 communicate pneumatically with manifold 42 . In the preferred embodiment valve 38 is an electrically actuated, normally closed, proportional valve and valve 40 is an electrically actuated, normally open, proportional valve. Valves 38 and 40 respond to valve control signals generated by microprocessor 32 . The level of the valve control signals influence the pressure of gas in calf sleeve 6 by determining the gas flow into and out of manifold 42 .
Pressure transducer 44 communicates pneumatically with the inflatable portion of calf sleeve 6 by means of tubing 16 and connector 15 . As shown in FIGS. 1 and 2 pressure transducer 44 does not communicate pneumatically with valve manifold 42 except through calf sleeve 6 . In this way, pressure transducer 44 directly and continuously measures the pressure of gas in the inflatable portion of calf sleeve 6 , irrespective of variables including the flow resistance of tubing 14 , the flow resistance of connector 13 , the design of calf sleeve 6 , the pneumatic volume of the inflatable portion of calf sleeve 6 , and the snugness of application of calf sleeve 6 to the limb of patient 8 . Pressure transducer 44 is electrically connected to an analog to digital converter (ADC) input of microprocessor 32 and generates a channel “B” sleeve pressure signal, the level of which is representative of the pressure of gas in calf sleeve 6 .
Valve 38 communicates pneumatically with manifold 42 through tubing 46 to gas pressure reservoir 36 . When activated valve 38 permits the flow of gas from reservoir 36 to manifold 42 and therefrom supplies pressurized gas through tubing 14 and connector 13 to the inflatable portion of calf sleeve 6 . Valve 40 pneumatically connects manifold 42 to atmosphere, allowing a controlled reduction of pressure from calf sleeve 6 .
As shown in FIG. 2, pneumatic pump 48 communicates pneumatically with reservoir 36 through tubing 50 . Pump 48 acts to pressurize reservoir 36 in response to control signals from microprocessor 32 . Reservoir pressure transducer 52 communicates pneumatically with reservoir 36 through tubing 54 and generates a reservoir pressure signal indicative of the pressure in reservoir 36 . Pressure transducer 52 is electrically connected to an ADC input of microprocessor 32 . In response to the reservoir pressure signal and a reservoir pressure reference signal, microprocessor 32 generates control signals for pump 48 and controls the pressure in reservoir 36 to maintain a pressure near the reference pressure represented by the reservoir reference pressure signal.
Multiple predetermined reference pressure waveforms suitable for application by foot sleeve 4 , and multiple predetermined pressure waveforms suitable for application by calf sleeve 6 , are stored within waveform register 56 .
For each reference waveform stored in waveform register 56 a corresponding set of reference values for predetermined waveform parameters is also stored in waveform register 56 . The predetermined waveform parameters are representative of desired characteristics of an applied pressure waveform used to augment the flow of venous blood. For example for an individual reference waveform these waveform parameters may include: (a) the maximum pressure applied during the cycle time period; (b) the rate of rise of pressure during a portion of the reference waveform cycle time period; (c) pressure thresholds which must be exceeded for predetermined time periods. Example reference values of these parameters are: (a) 45 mmHg for maximum pressure applied during the cycle time period; (b) 10 mmHg per second rate of pressure rise maintained for a period of 3 seconds; (c) a pressure threshold of 30 mmHg exceeded for a period of 7 seconds. As described further below, microprocessor 32 uses the reference values of these waveform parameters to verify that pressure waveforms having desired characteristics have been applied to the patient.
In the preferred embodiment pressure waveforms are stored in waveform register 56 as a set of values describing the amplitude of pressure at all times within one complete waveform cycle time period. It will be apparent to those skilled in the art that certain reference pressure waveforms could alternatively be stored as series of coefficients for a mathematical equation describing the waveforms, or a scaling factor and a set of values representing a normalized waveform. Similarly the corresponding reference values of the predetermined waveform parameters could be mathematically derived from the reference pressure waveform. Waveform register 56 responds to a waveform selection signal produced as described below. The level of the waveform selection signal determines which one of the stored predetermined reference pressure waveforms and the corresponding reference values of predetermined waveform parameters will be communicated to microprocessor 32 .
FIG. 3 illustrates three examples of reference pressure waveforms, reference pressure waveforms A, B and C, which are maintained in waveform register 56 . The waveforms over the complete cycle time period are shown. Each reference pressure waveform cycle has one or more discrete phases. In the context of the preferred embodiment, a phase of a reference pressure waveform is considered to be a variation in the amplitude of pressure during a time interval within the cycle time period having a shape adapted to produce a desired augmentation of the flow of venous blood proximally from a selected sleeve which is positioned on a limb near a desired location. Reference pressure waveforms A and C illustrate waveforms having two phases. Reference pressure waveform B illustrates a reference pressure waveform having a single phase. In the preferred embodiment the cycle time periods of reference pressure waveforms range between 50 and 200 seconds. The time intervals corresponding to phases of the reference pressure waveforms range between 2 and 20 seconds.
Reference pressure waveforms A and B shown in FIG. 3 are typical waveforms for application by calf sleeve 6 . Reference pressure waveform C is a typical waveform for application by foot sleeve 4 . Reference pressure waveforms A and C depicted in FIG. 3 have two different phases, indicated as phase 1 and phase 2 in FIG. 3 . The variation in pressure amplitude of phase 1 of each reference pressure waveform A and C shown in FIG. 3 is adapted to augment the flow of venous blood into the limb proximal to the sleeve from the limb beneath the sleeve by increasing the maximum blood velocity during the phase 1 time interval of the reference pressure waveform. The variation in pressure amplitude of phase 2 of waveforms A and C is adapted to augment the flow of venous blood into the limb proximal to the sleeve from the limb beneath the sleeve by increasing the mean blood velocity during phase 2 time interval of the waveform. Pressure waveform cycle B is shown with a single phase that is adapted to augment both mean and maximum venous blood flow proximally into the limb from the region underlying the pressurizing sleeve.
Referring again to FIG. 2, microprocessor 32 operates, when directed by an operator of instrument 2 through manipulation of controls 22 , to repetitively generate a selected reference pressure waveform in foot sleeve 4 connected to channel “A” of instrument 2 . Microprocessor 32 continues to repetitively produce the desired pressure waveforms in foot sleeve 4 until an operator through manipulation of controls 22 directs microprocessor 32 to suspend the generation of pressure waveforms, or alternatively until microprocessor 32 suspends the generation of pressure waveforms in response to an alarm signal as described below.
To generate pressure waveforms in foot sleeve 4 connected to channel “A”, microprocessor 32 first generates a channel “A” sleeve reference pressure waveform signal by retrieving from waveform register 56 a reference pressure waveform, as determined by the level of a channel “A” waveform selection signal produced by microprocessor 32 in response to an operator manipulating controls 22 .
The channel “A” sleeve reference pressure waveform signal is used by microprocessor 32 , in combination with a channel “A” sleeve pressure signal generated by pressure transducer 26 and the reservoir pressure signal as described below, to maintain the pressure in the sleeve connected to channel “A” of instrument 2 near the pressure represented by the channel “A” sleeve reference pressure waveform signal by generating control signals for valves 28 and valve 30 .
Microprocessor 32 subtracts the pressures represented by the levels of the channel “A” reference pressure waveform signal and the channel “A” sleeve pressure signal. The difference in pressure between the sleeve pressure and the reference waveform pressure is used by microprocessor 32 along with the pressure represented by the level of the reservoir pressure signal to calculate levels of control signals for valves 28 and 30 . Valves 28 and 30 respond to the control signals to increase, decrease or maintain the pressure in foot sleeve 4 connected to channel “A” such that the pressure within foot sleeve 4 at the time is maintained near the pressure represented by the level of the channel “A” reference pressure waveform signal.
To alert the operator when the pressures being generated in foot sleeve 4 are not within a desired limit of the pressures indicated by the channel “A” reference pressure waveform signal, microprocessor 32 generates alarm signals. Microprocessor 32 first compares the pressure in foot sleeve 4 to the pressure indicated by the level of the channel “A” reference pressure waveform signal. If the pressure in foot sleeve 4 exceeds the reference pressure by a pre-set limit of 10 mmHg, microprocessor 32 generates an alarm signal indicating over-pressurization of the sleeve connected to channel “A”. If the pressure in foot sleeve 4 is less than the reference pressure signal by a pre-set limit of 10 mmHg, microprocessor 32 generates an alarm signal indicating under-pressurization of the sleeve connected to channel “A”.
Microprocessor 32 also analyzes the channel “A” sleeve pressure signal generated by pressure transducer 26 representative of the pressure waveform being produced in foot sleeve 4 , in order to measure predetermined waveform parameters. The specific waveform parameters measured by microprocessor 32 are determined by the reference values of the waveform parameters corresponding to the channel “A” reference pressure waveform signal. If for example, microprocessor 32 has retrieved from waveform register 56 a reference value for the maximum pressure applied during the cycle time period microprocessor 32 will analyze the sleeve pressure signal and measure the value of the maximum applied pressure during the cycle time period.
Microprocessor 32 computes the differences between the measured values of the waveform parameters and the corresponding reference values of the waveform parameters. If the absolute differences between the measured and reference values are less than predetermined maximum variation levels microprocessor 32 retrieves a channel ‘A’ interval time from interval timer 58 and stores this channel ‘A’ interval time along with other information as described below in a location in therapy register 60 . Microprocessor 32 then generates a channel ‘A’ interval timer reset signal which is communicated to interval timer 58 .
To generate pressure waveforms in calf sleeve 6 connected to channel “B” of instrument 2 , microprocessor 32 operates in an equivalent manner to the operation of channel “A” as described above. Reference pressure waveforms and corresponding reference values of waveform parameters, interval times, alarm signals and valve control signals are produced independently of those produced for channel “A”.
When instructed by an operator of instrument 2 through manipulation of controls 22 , microprocessor 32 will initiate the sequential generation of pressure waveforms in foot sleeve 4 and calf sleeve 6 connected to channels “A” and “B”. The timing of the sequential generation of pressure waveforms in sleeves 4 and 6 may be selected by the operator to be: a) the initiation of a pressure waveform cycle by channel “B” at a predetermined time following the initiation of a pressure waveform cycle by channel “A”; or b) the initiation of a pressure waveform cycle by channel “B” upon the pressure within foot sleeve 4 connected to channel “A” exceeding a predetermined pressure level; or c) the initiation of a pressure waveform cycle by channel “B” upon slope of the pressure waveform within foot sleeve 4 connected to channel “A” exceeding a predetermined slope threshold; or d) the initiation of a pressure waveform cycle by channel “B” upon the channel ‘A’ interval time exceeding a predetermined threshold.
When instrument 2 is operating to generate pressure waveforms sequentially in foot sleeve 4 and calf sleeve 6 connected to channels “A” and “B”, the channel “B” interval time is computed and stored in therapy register 60 when the absolute values of the differences between the measured and reference values of both the channel “A” and channel “B” pressure waveform parameters are less than predetermined maximum variation levels. Microprocessor 32 then generates a channel ‘B’ interval timer reset signal which is communicated to interval timer 58 .
Interval timer 58 shown in FIG. 2 maintains independent timers for channel ‘A’ and channel ‘B’. In the preferred embodiment the timers are implemented as counters that are incremented every 100 ms. The rate at which the counters are incremented determines the minimum interval time that can be resolved. Microprocessor 32 communicates with interval timer 58 to read the current values of the counters and also to reset the counters. Interval timer 58 includes a battery as an alternate power source and continues to increment the counters during any interruption in the supply of electrical power from power supply 62 required for the normal operation of instrument 2 .
Microprocessor 32 generates alarm signals to alert the operator of instrument 2 , and patient receiving therapy from instrument 2 , if an excessive interval has elapsed between the application of pressure waveforms having desired reference values of waveform parameters. Microprocessor 32 periodically retrieves from interval timer 58 the current values of the channel ‘A’ and channel ‘B’ interval timers, if an interval time value exceeds a predetermined maximum of 5 minutes microprocessor 32 will generate an alarm signal associated with either channel ‘A’ interval time or channel ‘B’ interval time.
Real time clock 64 shown in FIG. 2 maintains the current time and date, and includes a battery as an alternate power source such that clock operation continues during any interruption in the supply of electrical power from power supply 62 required for the normal operation of instrument 2 . Microprocessor 32 communicates with real time clock 64 for both reading and setting the current time and date. Therapy register 60 shown in FIG. 2, records “events” related to the pressure waveforms generated in sleeves connected to channels “A” and “B” of instrument 2 , and thereby related to the therapy delivered to a patient by the preferred embodiment. “Events” are defined in the preferred embodiment to include: (a) actions by the operator to initiate the generation of pressure waveforms in a sleeve, to suspend the generation of pressure waveforms in a sleeve, or to select a reference pressure waveform for generation in a sleeve (b) alarm events resulting from microprocessor 32 generating alarm signals as described above; and (c) interval time events resulting from microprocessor 32 determining the interval between the application of pressure waveforms having predetermined desired parameters.
Microprocessor 32 communicates with therapy register 60 to record events as they occur. Microprocessor 32 records an event by communicating to therapy register 60 : the time of the event as read from real time clock 64 , and a value identifying which one of a specified set of events occurred and which channel of instrument 2 the event is associated with as determined by microprocessor 32 . Also, if the event relates to channel “A” of instrument 2 , therapy register 60 records the values at the time of the event of the following parameters: the channel “A” waveform selection signal, the channel “A” sleeve pressure signal, the channel “A” reference pressure waveform signal and the channel “A” interval time. Alternatively, if the event relates to channel “B” of instrument 2 , therapy register 60 records the values at the time of the event of the following parameters: the channel “B” waveform selection signal, the channel “B” sleeve pressure signal, the channel “B” reference pressure waveform signal and the channel “B” interval time.
Therapy register 60 retains information indefinitely in the absence or interruption of electrical power from power supply 62 required for the normal operation of therapy register 60 .
Microprocessor 32 , when directed by an operator of instrument 2 through manipulation of controls 22 , subsequently displays, prints or transfers to an external computer the values associated with events stored in therapy register 60 . For example, microprocessor 32 in response to an operator of instrument 2 manipulating controls 22 will retrieve from therapy register 60 all events associated with determining interval times and the corresponding information associated with those events. Microprocessor 32 will then tabulate the retrieved information and will present on graphic display 20 a display detailing the history of interval times between the application of pressure waveforms having desired reference parameters for channels ‘A’ and ‘B’ of instrument 2 . Also for example, microprocessor 32 in response to controls 22 will calculate and present on graphic display 20 the elapsed time between a first event recorded in therapy register 60 and a second event recorded in therapy register 60 by computing the difference between the time at which the first event occurred and the time when the second event occurred.
Referring to FIG. 2, and as described above operator input is by means of controls 22 . Signals from controls 22 , arising from contact closures of the switches that comprise controls 22 are communicated to microprocessor 32 .
Microprocessor 32 will, in response to generated alarm signals, alert the operator and patient by text and graphic messages shown on display panel 20 and by audio tones. Electrical signals having different frequencies to specify different alarm signals and conditions are produced by microprocessor 32 and converted to audible sound by loud speaker 66 shown in FIG. 2 .
Power supply 62 provides regulated DC power for the normal operation of all electronic and electrical components within instrument 2 .
II. Software
FIGS. 4, 5 , 6 and 7 , are software flow charts depicting sequences of operations which microprocessor 32 is programmed to carry out in the preferred embodiment of the invention. In order to simplify the discussion of the software, a detailed description of each software subroutine and of the control signals which the software produces to actuate the hardware described above is not provided. The flow charts shown and described below have been selected to enable those skilled in the art to appreciate the invention. Functions or steps carried out by the software are described below and related to the flow charts via parenthetical reference numerals in the text.
FIG. 4 shows the initialization operations carried out by the main program. FIG. 5 shows a software task associated with processing input from an operator and updating therapy register 60 . FIG. 6 shows a software task for controlling channel “A” of instrument 2 . FIG. 7 shows a software task associated with the determination of time intervals between the application of pressure waveforms having predetermined desired parameters.
FIG. 4 shows the initialization operations carried out by the system software. The program commences ( 400 ) when power is supplied to microprocessor 32 by initializing microprocessor 32 for operation with the memory system and circuitry and hardware of the preferred embodiment. Control is then passed to a self-test subroutine ( 402 ). The self-test subroutine displays a “SELF TEST” message on display panel 20 and performs a series of diagnostic tests to ensure proper operation of microprocessor 32 . Should any diagnostic test fail ( 404 ), an error code is displayed on display 20 ( 406 ) and further operation of the system is halted ( 408 ); if no errors are detected, control is returned to the main program.
Next, a software task scheduler is initialized ( 410 ). The software task scheduler executes at predetermined intervals software subroutines which control the operation of instrument 2 . Software tasks may be scheduled to execute at regularly occurring intervals. For example the subroutine shown in FIG. 6 and described below executes every 2 milliseconds. Other software tasks execute only once each time they are scheduled. The task manager ( 412 ) continues to execute scheduled subroutines until one of the following occurrences: a) power is no longer supplied to microprocessor 32 ; or b) the operation of microprocessor 32 has been halted by software in response to the software detecting an error condition.
FIG. 5 shows a flowchart of the software task associated with updating display 20 , processing input from an operator and testing for interval time alarm conditions. This task is executed at regular predetermined intervals of 50 milliseconds. Control is first passed to a subroutine that updates the menus of commands and values of displayed parameters shown on display 20 ( 500 ). The menus of commands and parameters shown on display 20 are appropriate to the current operating state of instrument 2 as determined and set by other software subroutines.
Control is next passed to a subroutine ( 502 ) which processes the input from controls 22 . In response to operator input by means of controls 22 other software tasks may be scheduled and initiated ( 504 ). For example, if the operator has selected a menu command to display the history of interval times between the application of pressure waveforms having desired reference parameters for channel ‘A’ software tasks will be scheduled to retrieve from therapy register 60 events associated with determining interval times and compute and display the history. The history of interval times may include the longest interval, and the cumulative total of all interval times between the application of pressure waveforms.
Control then passes to a subroutine ( 506 ) which determines if the operating parameters (reference pressure waveform selections, initiation or suspension of the application of pressure waveforms) of instrument 2 which affect the therapy delivered to a patient have been adjusted by an operator of instrument 2 . Current values of operating parameters are compared to previous values of operating parameters. If the current value of any one or more parameters differs from its previously set value control is passed to a subroutine ( 508 ) for recording events in therapy register 60 . This subroutine ( 508 ) records an event by storing the following in therapy register 60 : the time of the event as read from real time clock 64 ; and a value identifying which one or more of a specified set of events occurred and which channel of instrument 2 the event is associated with as determined by subroutine ( 506 ). Also, if the event relates to channel “A” of instrument 2 , the values of the following parameters at the time of the event are also stored in therapy register 60 : channel “A” waveform selection signal, channel “A” sleeve pressure signal, channel “A” reference pressure waveform signal and channel “A” interval time. Alternatively if the event relates to channel “B” of instrument 2 , the values of the following parameters at the time of the event are stored in therapy register 60 : channel “B” waveform selection signal, channel “B” sleeve pressure signal, channel “B” reference pressure waveform signal and the channel “B” interval time.
As shown in FIG. 5 control is next passed to a subroutine ( 510 ) which retrieves from interval timer 58 the values of the interval times for channel “A” and channel “B” of instrument 2 . If the channel “A” interval time is a above a predetermined threshold of 5 minutes ( 512 ) an alarm flag is set ( 514 ) to indicate that the channel “A” interval time has been exceeded. If the channel “B” interval time is above a predetermined threshold of 5 minutes ( 516 ) an alarm flag is set ( 518 ) to indicate that the channel “B” interval time has been exceeded.
Control is next passed to a subroutine ( 520 ) which compares the current alarm conditions to previous alarm conditions. If any one or more alarm conditions exist which did not previously exist, control is passed to a subroutine ( 522 ) for recording the alarm event in therapy register 60 . Subroutine ( 522 ) records an alarm event by storing in therapy register 60 the time of the event as read from real time clock 64 ; a value identifying which one or more of a specified set of alarm events occurred as determined by subroutine ( 520 ). Also, if the alarm event relates to channel “A” of instrument 2 , the values of the following parameters at the time of the event are also stored in therapy register 60 : channel “A” waveform selection signal, channel “A” sleeve pressure signal, channel “A” reference pressure waveform signal and the channel “A” interval time. Alternatively if the event relates to channel “B” of instrument 2 , the values of the following parameters at the time of the event are stored in therapy register 60 : channel “B” waveform selection signal, channel “B” sleeve pressure signal, channel “B” reference pressure waveform signal and the channel “B” interval time. The software task shown in FIG. 5 then terminates ( 524 ).
FIG. 6 depicts a software task associated with controlling channel “A” of instrument 2 . A similar software task exists for controlling channel “B”, but for simplicity only the task associated with channel “A” will be described. The software task shown in FIG. 6 is scheduled to execute continuously once every two milliseconds. As shown in FIG. 6, if channel “A” is not currently generating pressure waveforms ( 600 ) in foot sleeve 4 the valve control signal for valve 28 is set to a level that ensures valve 28 remains closed ( 602 ). The valve control signal for valve 30 is set to a level that ensures valve 30 remains open ( 604 ). Opening valve 30 vents any gas in foot sleeve 4 connected to channel “A” to atmosphere, and closing valve 28 prevents gas from flowing from reservoir 36 to foot sleeve 4 connected to channel “A”.
The channel “A” sleeve pressure signal is then sampled ( 606 ). If the pressure in foot sleeve 4 connected to channel “A” is above a predetermined threshold of 10 mmHg ( 608 ), an alarm flag is set ( 610 ) to indicate that the sleeve connected to channel “A’ is pressurized at a time when it should not be pressurized. The software task associated with controlling channel “A” then terminates ( 612 ).
As shown in FIG. 6, if channel “A” is currently generating pressure waveforms ( 600 ) in foot sleeve 4 , control is passed to a subroutine which samples the value of the channel “A” sleeve pressure signal ( 614 ). This subroutine ( 614 ) also stores the value in the memory of microprocessor 32 to permit microprocessor 32 to perform measurements of pressure waveform parameters as described further below. Control is then passed to a subroutine ( 616 ) which samples the channel “A” reference pressure waveform signal. The value of the sample obtained from the reference pressure waveform signal is representative of the desired sleeve pressure at the instant of time when the subroutine executes. An error signal is computed ( 618 ) by calculating the difference between the pressure indicated by the value of the channel “A” sleeve pressure signal and the value of the sample of the channel “A” reference pressure waveform signal. Control is passed to a subroutine ( 620 ) that compares the error signal to predetermined limits and sets an alarm flag ( 622 ) if the limits have been exceeded. Next, the signal from reservoir pressure transducer 52 is sampled ( 624 ). Control then passes to a subroutine ( 626 ) which calculates levels for the control signals for valve 28 and valve 30 . The subroutine ( 626 ) uses the current levels of the error signal and reservoir pressure signal, as well as previously stored levels of these signals, to compute new levels for the valve 28 and 30 control signals. When the calculation subroutine ( 626 ) completes, the software task shown in FIG. 6 terminates ( 612 ).
FIG. 7 depicts the software task associated with the determination of the time intervals between the application of pressure waveforms having predetermined desired parameters. This software task is scheduled to execute periodically whenever channel “A” is generating pressure waveforms in foot sleeve 4 . For simplicity only the software task associated with channel “A” has been shown in FIG. 7, a similar software task to the one shown in FIG. 7 is scheduled to execute periodically whenever channel “B” is generating pressure waveforms in calf sleeve 6 .
As shown in FIG. 7 a subroutine ( 700 ) that determines which specific waveform parameters are to be measured is executed. This subroutine ( 700 ) uses the values of the reference waveform parameters corresponding to the channel “A” reference pressure waveform to determine which waveform parameters of the channel “A” pressure signal are to be measured. For example, if reference values for maximum pressure in a cycle period and the rate of rise of pressure during a portion of the reference waveform cycle time period are associated with the reference pressure waveform signal used in the production of pressure waveforms by channel “A”; the subroutine ( 700 ) will select these as the waveform parameters to be measured.
Control is next passed to a subroutine ( 702 ) which analyzes the channel “A” sleeve pressure signal and measures the values of the waveform parameters as selected by the previously executed subroutine ( 700 ). Control then passes to a subroutine ( 704 ) that calculates the absolute difference between the measured values of the pressure waveform parameters and the corresponding reference values for these parameters. If the absolute differences between the measured and reference values are above predetermined thresholds ( 706 ) the software task shown in FIG. 7 terminates ( 708 ). If the absolute differences between the measured and reference values are not above predetermined thresholds ( 706 ) the control is passed to subroutine ( 710 )
This subroutine ( 710 ) retrieves the channel “A” interval time from interval timer 58 . Next control is passed to a subroutine ( 712 ) which records in therapy register 60 an interval time event. The subroutine ( 712 ) stores in therapy register 60 the time of the event as read from real time clock 64 and a value identifying that an interval time event associated with channel “A” has occurred. The subroutine ( 712 ) also stores the values of the following parameters at the time of the event: channel “A” interval time, channel “A” waveform selection signal, channel “A” reference pressure waveform and channel “A” sleeve pressure signal.
As shown in FIG. 7 control next passes to a subroutine ( 714 ) which resets the interval timer associated with channel “A”. The software task shown in FIG. 7 then terminates ( 708 ).
III. Sleeves
FIG. 8 is a plan view to illustrate details of foot sleeve 4 . Foot sleeve 4 is manufactured in a single size designed to accommodate 95% of normal adult feet. Foot sleeve 4 includes exterior layer 900 which forms a non-inflating portion, and bladder assembly 902 which forms an inflating portion. Exterior layer 900 is fabricated from a synthetic cloth material and has an outer and inner surface which allows engagement with a Velcro™ hook material.
As shown in plan view FIG. 8 and cross sectional view FIG. 9, bladder assembly 902 contains layer 904 and layer 906 . Layers 904 and 906 are fabricated from a flexible gas-impermeable thermoplastic polyvinylchloride sheet material permanently bonded together to form inflatable bladder 908 . The flexibility of this gas-impermeable polyvinylchloride sheet material is predetermined and substantially inextensible when bladder 908 is pressurized up to 300 mmHg.
Ports 910 and 912 are thermoplastic right-angle flanges. Port 910 , in combination with tubing 10 and connector 9 , provides a pneumatic passageway suitable for increasing or decreasing the gas pressure within bladder 908 of foot sleeve 4 . Port 912 , in combination with pressure transducer 26 , tubing 12 and connector 11 , is used in the preferred embodiment to enable direct, accurate and continuous measurement of gas pressure in foot sleeve 4 by transducer 26 . Such measurement will reflect the effects of variables such as the flow resistance of tubing 10 , the flow resistance of connector 9 , the design of foot sleeve 4 , the pneumatic volume of the inflatable portion of foot sleeve 4 and the snugness of application of foot sleeve 4 . Alternatively, it will be appreciated that direct, accurate and continuous measurement of pneumatic pressure within bladder 908 of foot sleeve 4 could be accomplished by embedding an electronic pressure transducer within bladder 908 .
Referring to FIG. 8 and FIG. 9, stiffener 914 located between exterior layer 900 and bladder assembly 902 , is permanently attached to layer 900 . The shape of stiffener 914 is pre-determined being of sufficient width and length to cover the medial plantar vein of the foot. Stiffener 914 fabricated from a thermoplastic sheet material has a predetermined thickness and rigidity to direct the inflated portion of bladder 908 above stiffener 914 toward the limb producing the desired applied pressure waveform when bladder 908 is inflated.
As shown in FIG. 8, fasteners 916 attached to layer 900 consist of rectangular sections of Velcro™ hook material which removably engage with the cloth surface of layer 900 ensuring that foot sleeve 4 remains secured to a limb when bladder 908 is inflated.
Foot sleeve 4 is manufactured by die cutting layer 900 from the desired synthetic cloth material. Two holes are cut into layer 908 providing access for ports 910 and 912 allowing them to protrude through layer 900 when bladder assembly. 902 is secured in place. Stiffener 914 , which is die cut from a thermoplastic sheet material into a predetermined shape, is then permanently heat sealed to layer 900 using Radio Frequency (RF) sealing equipment. Fasteners 916 are sewn to layer 900 such that the hooks of fasteners 916 face away from layer 900 .
Fabrication of bladder assembly 902 begins by die cutting layers 904 and 906 from a flexible polyvinylchloride sheet material. Two holes are die cut into layer 904 allowing ports 910 and 912 to be inserted into position and bonded in place using RF sealing equipment. With ports 910 and 912 facing away from layer 906 , layers 904 and 906 are heat sealed together forming bladder 908 . With fasteners 916 facing ports 910 and 912 of bladder assembly 902 , ports 910 and 912 are inserted into the holes in layer 900 such that ports 910 and 912 protrude through layer 900 . Manufacturing of foot sleeve 4 is completed by permanently fastening bladder assembly 902 to layer 900 using RF sealing equipment and by inserting pneumatic connectors 9 A and 11 A into the opening of ports 910 and 912 respectively.
FIG. 1 illustrates foot sleeve 4 communicating pneumatically with instrument 2 by means of pneumatic connectors 9 and 11 . As described above connector 9 A is physically incompatible with connector 11 B and does not mate with connector 11 B. Connector 11 A is physically incompatible with connector 9 B and does not mate with connector 9 B.
FIG. 10 is a plan view to illustrate details of calf sleeve 6 . Calf sleeve 6 is manufactured in a single size designed to conform to a variety of calf shapes and sizes accommodating 95% of the normal adult population. As illustrated in plan view FIG. 10 and cross sectional view FIG. 11, calf sleeve 6 includes bladder 1100 which forms an inflatable portion surrounded by and an non-inflatable portion. Bladder 1100 of calf sleeve 6 is formed by permanently bonded together layers 1102 and 1104 using Radio Frequency (RF) sealing equipment.
Layers 1102 and 1104 are fabricated from a flexible gas-impermeable thermoplastic polyvinylchloride sheet material. The rigidity and thickness of this gas-impermeable sheet material is predetermined allowing layers 1102 and 1104 to be substantially inextensible when bladder 1100 is pressurized up to 60 mmHg.
Ports 1106 and 1108 are thermoplastic right-angle flanges. Port 1106 , in combination with tubing 14 and connector 13 , provides a pneumatic passageway suitable for increasing or decreasing the gas pressure within bladder 1100 of calf sleeve 6 . Port 1108 , in combination with pressure transducer 44 , tubing 16 and connector 15 , is used in the preferred embodiment to enable direct, accurate and continuous measurement of gas pressure in calf sleeve 6 by transducer 44 . Such measurement will reflect the effects of variables such as the flow resistance of tubing 14 , the flow resistance of connector 13 , the design of calf sleeve 6 , the pneumatic volume of the inflatable portion of calf sleeve 6 and the snugness of application of calf sleeve 6 . Alternatively, it will be appreciated that direct, accurate and continuous measurement of pneumatic pressure within bladder 1100 of calf sleeve 6 could be accomplished by embedding an electronic pressure transducer within bladder 1100 .
Shown in FIG. 10, Velcro™ loop fasteners 1110 and Velcro™ hook fasteners 1112 removably engage each other allowing application and removal of calf sleeve 6 . Fasteners 1110 and 1112 ensure that calf sleeve 6 remains secured a limb when bladder 1100 is inflated. Velcro™ loop fasteners 1110 and Velcro™ hook fasteners 1112 have a thermoplastic coating on one side allowing loop fasteners 1110 to be bonded to the outer surface of thermoplastic layer 1104 and hook fasteners 1112 to be bonded to the outer surface of thermoplastic layer 1102 .
Calf Sleeve 6 is manufactured by die cutting layers 1102 and 1104 from a polyvinylchloride thermoplastic sheet material. Two holes are die cut into layer 1104 providing access for ports 1106 and 1108 . Ports 1106 and 1108 are inserted through the holes in layer 1104 and bonded to layer 1104 using RF sealing equipment. Velcro™ loop fasteners 1110 are permanently RF sealed to the outer surface of layer 1104 by positioning the thermoplastic coating on fasteners 1110 in contact with thermoplastic layer 1104 .
With ports 1106 and 1108 facing away from layer 1102 , layer 1104 and layer 1102 are RF sealed together forming bladder 1100 . Hook fasteners 1112 are then RF sealed to the outer surface of layer 1102 as illustrated in FIG. 10 . Manufacturing of calf sleeve 6 is completed by inserting pneumatic connectors 13 A and 15 A into the opening of ports 1106 and 1108 respectively.
FIG. 1 illustrates calf sleeve 6 communicating pneumatically with instrument 2 by means of pneumatic connectors 13 and 15 . As described above connector 13 A is physically incompatible with connector 15 B and does not mate with connector 15 B. Connector 15 A is physically incompatible with connector 13 B and does not mate with connector 13 B.
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Apparatus for applying pressure to a patient's limb in order to augment venous blood flow in the limb and for monitoring the applied pressure, includes supplying a gas at a varying supply pressure to an inflatable sleeve that fits onto a limb to apply a varying pressure to the limb beneath the sleeve when inflated with the gas. A pressure transducer measures the pressure of gas in the inflatable sleeve and produces a sleeve pressure signal indicative of the estimated level of pressure. The apparatus measures the value of a predetermined pressure waveform parameter and produces a waveform parameter signal indicative of the measured value of the predetermined pressure waveform parameter. An interval signal is produced as indicative of an interval between a first occurrence when the measured value of the predetermined pressure waveform parameter is near a predetermined parameter level and the next occurrence when the measured value of the predetermined pressure waveform parameter is near the predetermined parameter level.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is related to co-pending U.S. patent application Ser. No. 13/288,491 filed Nov. 3, 2011, which is incorporated by reference herein in its entirety.
BACKGROUND INFORMATION
[0002] 1. Field
[0003] The present disclosure generally relates to composite columnar structures, and deals more particularly with a hybrid composite tubular strut internally reinforced to better resist axial compression loads.
[0004] 2. Background
[0005] Columnar structures formed of composites are used in a variety of applications because of their favorable strength-to-weight ratio. For example, composite tubular struts may be used in the aerospace industry as a support or brace for transferring loads in either direction along the longitudinal axis of the strut, thus placing the strut in either compression or tension. Fittings on the ends of the strut provide additional strength at the points of attachment of the strut to a structure.
[0006] The tubular struts mentioned above may be fabricated from fiber reinforced resin laminates. Such laminates may exhibit greater load carrying ability when placed in tension than when placed in compression. This is because the compressive strength of the resin is generally less than its tensile strength. Consequently, in order to meet performance specifications, it may be necessary to over-size the strut to carry a specified level of compression loading. Over-sizing the strut, however, may add cost and/or undesired weight to a vehicle or other structure to which the strut is attached.
[0007] Accordingly, there is a need for a composite columnar structure that exhibits improved ability to carry compression loads. There is also a need for a cost effective method of making a columnar structure with improved compression load carrying ability that adds little or no weight to the structure.
SUMMARY
[0008] The disclosed embodiments provide a composite columnar structure such as a tubular strut that exhibits an improved ability to resist axial compression loads while adding little or no weight to the structure. Improved compression load capability is achieved by incorporating a sleeve-like reinforcement around laminated plies forming a core of the strut. The reinforcement allows composite tubular struts and similar columnar structures to be designed that are “right-sized” to meet both compression and tension load carrying specifications while minimizing the weight of the strut.
[0009] According to one disclosed embodiment, a columnar structure is provided comprising a generally hollow laminate core, an outer composite skin, and reinforcement. The reinforcement surrounds the laminate core and is sandwiched between the laminate core and the outer skin for reacting compressive loads imposed on the columnar structure. The laminate core may be substantially tubular and the reinforcement may include a layer of material extending substantially completely around the laminate core. The layer of material may be one of a metal such as without limitation, titanium, a precured fiber reinforced composite or a ceramic, and the laminate core may be a fiber reinforced resin such as a carbon fiber reinforced plastic. The reinforcement may comprise first and second halves that are seamed together in a direction parallel to the axis of the laminate core. In one embodiment, the reinforcement may include corrugations on the inside wall thereof which may control wrinkling of underlying laminate plies of the core during consolidation and curing of the laminate.
[0010] According to another embodiment, a strut comprises a generally tubular, fiber reinforced resin core, and a sleeve-like reinforcement around the core having a compressive strength greater that the compressive strength of the resin. The sleeve-like reinforcement may be a corrugated metal, and may include first and second halves assembled together along seams extending in the longitudinal direction of the tubular core. The strut may further comprise a pair of spaced apart end fittings including a pair of attachment pins adapted to attach the strut to a structure. The pins lie substantially in a first plane, and the seams lie substantially in a second plane generally perpendicular to the first plane. In one variation, the sleeve-like reinforcement is a ceramic. In another variation, the sleeve-like reinforcement is titanium, and the fiber reinforced resin core is carbon fiber reinforced plastic. The sleeve-like reinforcement is co-bonded to the core and to the outer skin.
[0011] According to still another embodiment, a method is provided of making a strut, comprising fabricating a composite laminate core, fabricating a sleeve-like reinforcement, assembling the reinforcement over the core, and fabricating an outer skin over the sleeve-like reinforcement. The method may further comprise co-bonding the sleeve-like reinforcement to the core and to the outer skin. Fabricating the sleeve-like reinforcement may include forming corrugations on an inside face of a metal member. Fabricating the composite laminate core includes laying up plies of a fiber reinforced resin, and assembling the sleeve-like reinforcement over the core includes placing the metal member on the core with the corrugations against the laid up plies of the core. The method may further comprise consolidating and curing the core, and using the corrugations on the metal member to control wrinkling of the plies during the consolidation.
[0012] The features, functions, and advantages can be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments in which further details can be seen with reference to the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The novel features believed characteristic of the illustrative embodiments are set forth in the appended claims. The illustrative embodiments, however, as well as a preferred mode of use, further objectives and descriptions thereof, will best be understood by reference to the following detailed description of an illustrative embodiment of the present disclosure when read in conjunction with the accompanying drawings, wherein:
[0014] FIG. 1 is an illustration of a perspective view of a hybrid composite tubular strut exhibiting an improved ability to resist axial compression loads according to one disclosed embodiment.
[0015] FIG. 2 is an illustration of a sectional view taken along the line 2 - 2 in FIG. 1 .
[0016] FIG. 3 is an illustration of a perspective view of the strut shown in FIG. 1 in an intermediate stage of fabrication in which two halves of a reinforcement are being installed on a laminate core.
[0017] FIG. 4 is an illustration similar to FIG. 3 , but showing the two halves of the reinforcement having been installed.
[0018] FIG. 5 is an illustration similar to FIG. 4 but showing an alternate embodiment of the reinforcement having corrugations.
[0019] FIG. 6 is an illustration of a perspective view of the corrugated reinforcement, in the area shown as 6 - 6 in FIG. 5 .
[0020] FIG. 7 is an illustration of the area designated as FIG. 7 in FIG. 2 , but illustrating use of the corrugated form of the reinforcement.
[0021] FIG. 8 is an illustration of a cross sectional view of another form of the reinforcement.
[0022] FIG. 9 is an illustration of a flow diagram of a method of fabricating a hybrid composite columnar structure according to the disclosed embodiments.
[0023] FIG. 10 is an illustration of a flow diagram of aircraft production and service methodology.
[0024] FIG. 11 is an illustration of a block diagram of an aircraft.
DETAILED DESCRIPTION
[0025] Referring first to FIG. 1 , a composite columnar structure illustrated as an elongate strut 20 includes a generally cylindrical, tubular body 22 and a pair of end fittings 24 for attaching the strut 20 to a structure (not shown). The strut 20 may function to transfer compression loads along the longitudinal axis 25 of the tubular body 22 , and may also transfer loads that place the tubular body 22 in tension. Each of the end fittings 24 may be made of a metal such as aluminum or titanium, or a composite or other suitable materials. The end fittings 24 may be fabricated by casting, machining, or other common manufacturing techniques. In applications where the end fittings 24 are formed of composite materials, they may include metallic inserts and/or metallic bushings (not shown).
[0026] Each of the end fittings 24 may include a clevis 26 having a central opening 28 aligned along an axis 32 for receiving a clevis pin 30 that attaches the strut 20 to the structure. The axes 32 of the clevis pins 30 lie substantially in the same plane 35 . The clevis pins 30 along with clevis 26 , form pivotal connections between the strut 20 and the structure to which it is attached. The strut 20 may be employed, for example and without limitation, as a brace between an aircraft engine (not shown) and an airframe (not shown). Any of a variety of other types of end fittings 24 are possible, depending on the intended use of the strut 20 . Also, as previously mentioned, the strut 20 may function to transfer axial loads biaxially along the longitudinal axis 25 of the strut 20 so that the strut 20 may be placed either in tension or compression or both in an alternating fashion along the longitudinal axis 25 . In some applications, the strut 20 may also experience limited torsional loading. In the illustrated example, the cross sectional shape of the tubular body 22 is substantially round and constant along its length, however other cross sectional shapes are possible, such as, without limitation, square, triangular, hexagonal or pentagonal shapes. Also, the tubular body 22 may have one or more tapers along its length.
[0027] Referring now to FIG. 2 , the tubular body 22 broadly comprises a generally cylindrical, sleeve-like reinforcement 36 sandwiched between a cylindrical core 34 and an outer skin 38 . The sleeve-like reinforcement 36 increases the compressive strength of the tubular body 22 . The core 34 may comprise multiple plies 48 ( FIG. 7 ) of a suitable fiber reinforced resin, such as, without limitation, carbon fiber reinforced plastic (CFRP) that may be laid up over a removable mandrel (not shown) by manual or conventional automated layup techniques. The outer skin forms a protective covering over the sleeve-like reinforcement 36 and may also comprise multiple laminated plies of a fiber reinforced resin. The plies of the outer skin 38 also hold the sleeve-like reinforcement 36 in place and may enable the reinforcement 36 to better resist compressive loading.
[0028] In one embodiment, the sleeve-like reinforcement is cylindrical in shape and may comprise a layer of material 42 formed as semi-circular first and second reinforcement halves 36 a , 36 b that extend substantially the entire length of the tubular body 22 . In other embodiments, the layer of material 42 may comprise a single member or more than two members. The layer 42 may comprise a suitable material that exhibits the desired degree of compression strength, such as a metal foil or a ceramic, and is compatible with the material forming the core 34 . For example, where the core 34 is formed of CFRP, the layer of material 42 forming the reinforcement 36 may comprise titanium. The layer 42 may also comprise a precured resin that contains unidirectional reinforcement fibers such as, without limitation, steel fibers which resist axial compression loads applied to the strut 20 . The compressive strength of the sleeve-like reinforcement 36 is greater than that of the resin forming the core 34 in order to increase the overall compressive strength of the strut 20 .
[0029] In the illustrated example employing a two-piece reinforcement 36 , the halves 36 a , 36 b may be preformed and then assembled around the core 34 , forming diametrically opposite joint lines or seams 44 . The reinforcement halves 36 a , 36 b may or may not be mechanically joined along the seams 44 . In one embodiment, although not shown in the Figures, the two halves 36 a , 36 b may overlap each other along the seams 44 in order to allow the halves 36 a , 36 b to slip relative to each other and collapse slightly as the underlying core 34 shrinks during consolidation and curing of the core 34 . The thickness “T” of the layer of material 42 may vary with the application, depending upon the amount of compressive strength that is desired to be added to the strut 20 . While only a single cylindrical reinforcement 36 is shown in the illustrated example, the strut 20 may include multiple axially concentric reinforcements 36 (not shown) embedded in the tubular body 22 . In still other embodiments, the reinforcement 36 and/or the core 34 may taper from a thin cross section portion to a thicker cross section portion along the length of the tubular body 22 , while the outer cylindrical shape of the tubular body 22 remains substantially constant.
[0030] Referring to FIG. 3 , strut 20 may be assembled by laying up plies 48 ( FIG. 7 ) of the core 34 over end fittings 24 , however other methods of attaching the end fittings 24 to the core 34 are possible. The two halves 35 a , 36 b of the sleeve-like reinforcement 36 may be preformed by any suitable process, and then assembled over the core 34 . Depending of the thickness “T” ( FIG. 2 ) of the reinforcement 36 , the reinforcement 36 may be formed-to-shape by forming a layer of material 42 over the core 34 , using the core 34 as a mandrel. FIG. 4 illustrates the two halves 36 a , 36 b having been assembled over the core 34 and depicts one of the seams 44 , which, as previously mentioned, may represent a mechanical joint line attachment of the two halves 36 a , 36 b . The circumferential location of the seams 44 may be chosen so as to optimize the buckling strength of the tubular body 22 . For example, in the illustrated embodiment, the seams 44 may be located circumferentially such that they lie in or near a plane 37 ( FIGS. 1 and 2 ) that is substantially perpendicular to the plane 35 of the clevis pins 30 . Orienting the seams 44 generally perpendicular to the axes of the pins 30 in this manner may better enable the reinforcement 36 to resist bending moments in a plane near or substantially parallel to or within the plane 35 and thereby improve the bucking strength of the strut 20 . However, it should be noted that the benefits provided by the disclosed embodiments may be realized even when the seams 44 are not located at circumferential positions that optimize the buckling strength of the strut 20 .
[0031] FIG. 5 illustrates an alternate embodiment of the strut 20 that includes a two-piece sleeve-like cylindrical reinforcement 36 having corrugations 46 . Referring to FIG. 6 , the corrugations 46 include circumferentially spaced, longitudinally extending corrugation ridges 46 a on the inside face 45 of the reinforcement 36 . The corrugations 46 may be formed by any of a variety of processes that are suited to the material from which the reinforcement 36 is made. Referring to FIG. 7 , it can be seen that the ridges 46 a of the corrugation 46 extend down into and are compressed against the laminated plies 48 of the core 34 . During consolidation and curing of the strut 20 , the core shrinks and the corrugation ridges 46 a are compacted against the core 34 , tending to control wrinkle formation in the plies 48 of the core 30 . This wrinkle control is achieved as a result of the corrugation ridges 46 a depressing and lengthening portions of the plies 48 around the ridges 46 a in order to tighten and/or absorb the shrinkage of the plies 48 during consolidation/curing.
[0032] The ability of the sleeve-like reinforcement 36 to control wrinkling of the underlying plies 48 during the consolidation process may be achieved using other forms of the reinforcement 36 . For example, referring to FIG. 8 , in lieu of corrugating the layer of material 42 comprising the reinforcement 36 as described above, longitudinally extending, spaced apart raised strips 47 of any suitable material may be applied by a suitable technique to the inside face 45 of the layer of material 42 , either before or after the layer of material 42 has been formed into the desired shape.
[0033] Attention is now directed to FIG. 9 which illustrates the overall steps of a method of fabricating the composite tubular strut 20 described previously. Beginning at 50 , laminated core 30 is fabricated by laying up composite plies 48 over a suitable mandrel (not shown), which may be for example, an inflatable or ablative mandrel. Next, at 52 , the reinforcement 36 may be fabricated either by preforming one or more layers of material 42 into halves 36 a , 36 b of the desire cross sectional shape, or by forming the material over the core 30 , using the core 30 as a mandrel. At step 54 , a suitable adhesive is applied over the core 30 , following which at 56 , the reinforcement 36 is assembled over the core 30 . The seams 44 between the reinforcement halves 36 a , 36 b may be located such that they lie substantially in a plane 37 that is substantially perpendicular to the plane 35 of the clevis pin 30 axes 32 in order to better resist bending forces, however, the seams 44 may be located at other points, depending on the construction and geometry of the end fittings 24 . At step 58 a suitable adhesive is applied over the reinforcement 36 . At step 60 , outer skin is applied over the reinforcement 36 by laying up additional composite plies over the reinforcement 36 . At step 62 , the strut 20 is debulked, compacted and cured, thereby co-bonding the reinforcement 36 to the core 30 and the outer skin 38 . Finally, at step 64 , the mandrel on which the core 30 is laid up may be removed.
[0034] Embodiments of the disclosure may find use in a variety of potential applications, particularly in the transportation industry, including for example, aerospace, marine, automotive applications and other application where automated layup equipment may be used. Thus, referring now to FIGS. 10 and 11 , embodiments of the disclosure may be used in the context of an aircraft manufacturing and service method 70 as shown in FIG. 10 and an aircraft 72 as shown in FIG. 11 . Aircraft applications of the disclosed embodiments may include, for example, without limitation, load transferring members such as struts, supports, connecting rods and similar columnar structures. During pre-production, exemplary method 70 may include specification and design 74 of the aircraft 72 and material procurement 76 . During production, component and subassembly manufacturing 78 and system integration 80 of the aircraft 72 takes place. Thereafter, the aircraft 72 may go through certification and delivery 82 in order to be placed in service 84 . While in service by a customer, the aircraft 72 is scheduled for routine maintenance and service 86 , which may also include modification, reconfiguration, refurbishment, and so on.
[0035] Each of the processes of method 70 may be performed or carried out by a system integrator, a third party, and/or an operator (e.g., a customer). For the purposes of this description, a system integrator may include without limitation any number of aircraft manufacturers and major-system subcontractors; a third party may include without limitation any number of vendors, subcontractors, and suppliers; and an operator may be an airline, leasing company, military entity, service organization, and so on.
[0036] As shown in FIG. 11 , the aircraft 72 produced by exemplary method 70 may include an airframe 88 with a plurality of systems 90 and an interior 92 . Examples of high-level systems 90 include one or more of a propulsion system 94 , an electrical system 96 , a hydraulic system 98 , and an environmental system 100 . Any number of other systems may be included. Although an aerospace example is shown, the principles of the disclosure may be applied to other industries, such as the marine and automotive industries.
[0037] Systems and methods embodied herein may be employed during any one or more of the stages of the production and service method 70 . For example, components or subassemblies corresponding to production process 78 may be fabricated or manufactured in a manner similar to components or subassemblies produced while the aircraft 72 is in service. Also, one or more apparatus embodiments, method embodiments, or a combination thereof may be utilized during the production stages 78 and 80 , for example, by substantially expediting assembly of or reducing the cost of an aircraft 72 . Similarly, one or more of apparatus embodiments, method embodiments, or a combination thereof may be utilized while the aircraft 72 is in service, for example and without limitation, to maintenance and service 86 .
[0038] The description of the different advantageous embodiments has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Further, different advantageous embodiments may provide different advantages as compared to other advantageous embodiments. The embodiment or embodiments selected are chosen and described in order to best explain the principles of the embodiments, the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.
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A columnar structure comprises a generally hollow laminate core, an outer composite skin, and a sleeve-like reinforcement. The sleeve-like reinforcement surrounds the laminate core and is sandwiched between the laminate core and the outer composite skin for reacting compressive loads imposed on the columnar structure.
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BACKGROUND OF THE INVENTION
[0001] The invention encompassed by the embodiments described in this application relates generally to a device for efficiently and effectively killing and exterminating moles that includes firing a projectile into the mole. Moles can be a nuisance by digging tunnels in lawns, golf courses, gardens, etc. in search of their main food source, worms. Moles can excavate 12-15 feet of tunnel per hour. When excavating, moles use their powerful front paws to push the dirt outward from the tunnel, which includes creating dirt piles above the ground surface that are clearly visible. The resulting mole tunnels can undermine and damage lawns, concrete slabs, driveways, pools, and even shallow foundations. Extensive mole tunnel networks can cause severe damage to a lawn requiring expensive repairs that can include tilling and replanting of an entire lawn.
[0002] A plunger- or spear-type trap (or simply “spear mole trap”) is shown in FIG. 6 . The trap shown in FIG. 6 includes setting tee 101 , a chain 102 , a safety pin 103 , legs 104 , a trigger latch 105 , a spear plate 106 , a trigger pan lip 107 , a trigger pan 108 , spines 109 , and a spring (not numbered). To set the plunger- or spear-type trap shown in FIG. 6 , a user makes a depression with his/her thumbs or hand in the center of an active mole tunnel. The trigger pan can be arranged ½ to 1 inch down in this depression or blockage by pushing the trigger pan downward, which can be accomplished when engaging or setting the trap. The user positions the trap over the depression with the legs straddling the tunnel. The trap is pushed into the soil until the trigger pan lays flat on top of the depression. The trigger latch is lifted and the trigger pan is pushed into the tunnel depression. The trigger latch should lie outside of the trigger pan lip. Holding the frame of the trap firmly with one hand, the second hand pulls upward on the setting tee, so that the latch slides into position inside of the pan lip, holding the plate and spikes above the tunnel. FIG. 7 shows the trap of FIG. 6 set in a shallow mole tunnel.
[0003] A disadvantage with the plunger- or spear-type trap is the need to preset the tines or spikes. The tines or spikes can impale the user, if the trap is mishandled, or if the trap slips during setting. Further, the plunger- or spear-type trap requires a strong spring for forcing the tines or spikes downward into the mole. Accordingly, setting the trap necessitates overcoming or struggling with the strong spring. An additional disadvantage of the plunger- or spear-type trap is that it can be ineffective in killing the mole. For example, the plunger- or spear-type trap can impale a mole without immediately killing the mole. This causes the mole a great amount of suffering and cruelty prior to death.
SUMMARY OF INVENTION
[0004] Objectives and features of the embodiments described in this application include use of a projectile, such as a bullet or pellet, driven by an explosive force to kill a mole. The mole gun described in this application can be easy and inexpensively manufactured.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a side view of an embodiment within the scope of this patent application prior to being armed or set.
[0006] FIG. 2 is a partial perspective view of an embodiment within the scope of this patent application in an armed or set position.
[0007] FIGS. 3A and 3B are enlarged cross-sectional side views of a first representative barrel assembly in accordance with the scope of this patent application.
[0008] FIG. 4 is an enlarged cross-sectional side view of a representative second barrel assembly in accordance with the scope of this patent application.
[0009] FIG. 5 is an enlarged cross-sectional side view of a third representative barrel assembly in accordance with the scope of this patent application.
[0010] FIG. 6 is a side view of a plunger- or spear-type trap prior to being armed or set.
[0011] FIG. 7 is a side view of a plunger- or spear-type trap in an armed or set position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The following embodiments and aspects thereof are described and illustrated in conjunction with structures and methods that are meant to be exemplary and illustrative, and not limiting in scope. In various embodiments, one or more of the above-described problems with plunger- or spear-type traps are reduced or eliminated, while other embodiments are directed to other improvements.
[0013] Representative mole guns as described this application are shown in FIGS. 1 and 2 . FIG. 1 shows a mole gun prior to being armed or set. FIG. 2 shows a mole gun in an armed or set position. In the following descriptions, the same reference numbers have been used to identify the structures shown in FIGS. 1-5 . Different configurations, structures or embodiments of the various elements shown in these figures can be used in other of the embodiments of the present application shown in these figures. In addition, the embodiments and aspects of the invention described in this application are described and illustrated in conjunction with various structures that are meant to be exemplary and illustrative, and not limiting in scope. In any of the various embodiments, modification or use of different structures to obtain the same functionality can be employed within the scope of the invention described herein.
[0014] The device in FIG. 1 includes a frame 10 having upper and lower sections. The frame can be made of any suitable material (i.e., metal, reinforced plastic) that has sufficient strength to support the components fixedly and slidably attached thereto as described in this application. For example, the frame can be formed from a flat elongated piece of metal into the shape shown in FIG. 1 . FIG. 1 shows right and left legs of the frame perpendicular to each other. While other arrangements can be used, this arrangement provides a frame with stability when inserted into the ground. The lower section of the frame or the bottom ends of the frame in particular can be pointed for easier insertion into the ground.
[0015] Generally, the mole gun described in this application can be inserted into the ground in the same manner as that for the plunger- or spear-type trap shown in FIGS. 6 and 7 . In a useful arrangement, the frame 10 can have a height approximately three times longer than its width and/or depth, although many other arrangements can also be used and adapted for different situations.
[0016] A bar 15 can be arranged at a central location within the frame 10 , such as relative to its width. The bar 15 can generally extend vertically and pass through the frame, such as at a upper middle portion thereof. The bar 15 can include holes, one of which accepts one end of a safety chain and another which accepts a safety pin. The safety pin is secured to another end of the safety chain. A handle can be arranged at an upper end of the bar 15 . The handle and bar can form a T-shape. The handle eases the effort necessary when pulling the bar upward and engaging the trap. A guide plate 17 can be arranged at the bottom end of the bar 15 . The guide plate can have an opening 23 therein (i.e., hole, slot, etc.), such as at one end thereof along the lines shown at 23 in FIGS. 1 and 2 , that slides along the frame 10 .
[0017] The opening 23 of the guide plate 17 , by receiving or cooperating with the frame 10 of the mole gun 1 , assists in controlling the sliding movement of the guide plate 17 and assuring that an impingement device 18 hits its target (an explosive device arranged in the barrel assembly 19 ), when the guide plate 17 moves downward. An impingement device 18 , which can be configured as or to include a firing pin, is arranged on a bottom side of the guide plate and is typically arranged on the side of the guide plate opposite the bar 15 . The barrel assembly 19 is secured to the frame 10 directly underneath the guide plate 17 , so that the impingement device 18 (i.e., firing pin) of the guide plate 10 contacts the barrel assembly 19 , when it is released from its armed or set position. The barrel assembly can be secured to the frame by using any suitable fastening devices. In the arrangement shown in FIGS. 1 and 2 , braces or brackets 20 , 21 are used to secure the barrel assembly 19 to the frame 10 . Brace 14 can optionally be used to provide additional stability to the frame 10 . The braces or brackets 14 , 20 , and 21 can be joined to the frame 10 and the barrel assembly 19 by any suitable securing devices, such as rivets 24 , screws or other. The securing devices can include welding, brazing, gluing, or any other suitable joining means. The other various elements described in these embodiments, such as joining together the trip plate 11 and the extension therefor (i.e., trip plate extension 12 ), can be joined together in a similar manner.
[0018] In the embodiments shown in FIGS. 1 and 2 , the mole gun 1 has a trigger mechanism for triggering the explosive charge. The trigger mechanism includes a trip plate 11 , which can be generally an elongate plate, and a latch 13 . The trip plate 11 includes a trip plate actuator 22 . The mole gun described in this application can be inserted into the ground in the same manner as that for the plunger- or spear-type trap shown in FIG. 7 . When in the armed position, such as shown in FIG. 2 , the guide plate 17 is held in or by a notch (not numbered) provided in the upper portion of the latch 13 , and the bottom tip of the latch 13 is held by the trip plate actuator 22 . The guide plate 17 is biased or forced downward by spring 16 and/or by gravity. The downward force of the guide plate 17 against the bottom surface of the notch in the latch 13 forces the bottom tip of the latch 13 rightward and against trip plate actuator 22 . The latch 13 is held in this position by the bottom tip of the latch 13 pressing against the trip plate actuator 22 . The trip plate 11 and latch 13 are operably connected and movable relative to the frame 10 and barrel assembly 19 , so that any upward force received by the trip plate 11 (i.e., the portion of the trip plate 11 arranged above the mole tunnel) causes of the front end of the trip plate 11 to pivot upwards, while the rear end of the trip plate pivots downward. The downward movement of the rear end of the trip plate 11 causes the bottom tip (or simply “bottom”) of the latch 13 to release from the trip plate actuator 22 . When the latch 13 is released, the guide plate 17 is released and forced downward by spring 16 and/or gravity. Downward movement of the guide plate 17 causes the impingement device 18 to strike and detonate the explosive charge (i.e., bullet 22 as shown in FIG. 5 ) forcing a projectile (i.e., bullet 22 as shown in FIG. 5 ) out of the projectile bore 32 and into a mole.
[0019] The barrel assembly 19 of the mole gun described in this application can be armed by placing an explosive charge in the explosion chamber 31 and arranging a projectile in the projectile bores 32 , as shown in FIG. 3A . For example, the projectile can be inserted into the projectile bore 32 at opening 33 and held near the opening of the projectile bore 32 by friction against the surface of the projectile bore. Alternatively, the projectile can be moved or pushed into a position anywhere along the length of the projectile bore 32 from the opening 33 to the pellet stop F, such as shown in FIG. 3A . These procedures for arming the barrel assembly 19 can be carried out before or after arming or cocking the guide plate 17 , which is described elsewhere in this application. More than one projectile can be inserted into a respective projectile bore 32 . Generally in this application, expressions such as “loading,” “arming,” “setting,” “cocking,” etc. of the mole gun include both arming or loading the barrel assembly 19 and the setting or engaging of the trip plate 11 and the latch 13 in the set position, the latter which is shown in FIG. 2 .
[0020] The trip plate extension 12 provides the mole gun as described in this application with advantages over the plunger- or spear-type trap shown in FIGS. 6 and 7 . Many of the advantages of the trip plate extension 12 are concerned with safety. For example, the trip plate extension 12 can be used to assist in arming or cocking the mole gun. The device described in this application can be inserted into the ground in a manner similar to that for the plunger- or spear-type trap shown in FIGS. 6 and 7 . Thereafter, one hand of the user can be used to move the guide plate 17 /impingement device 18 into position. This can be accomplished by placing the thumb of the one hand of the user at the top of the frame 10 , pulling the guide plate 17 upward by using a squeezing or pulling action; and once in position, using the fingertips of the one hand to engage or hold the edge of the guide plate 17 /impingement device 18 in position. The other hand of their user can then lift the trip plate extension 12 and engage the trip plate actuator 22 of the trip plate 11 and the bottom tip of the latch 13 . This procedure is safer than reaching inside the mole gun (i.e., underneath the area occupied by the barrel assembly 19 ) and engaging the trip plate actuator 22 with the bottom tip of the latch 18 , where release of the guide plate 17 could cause the impinging device 18 to strike the explosive charge, thereby causing the explosive charge to explode and fire a projectile possibly into the user's hand.
[0021] The trip plate extension 12 can also be used to safely disarm or uncock the mole gun. For example, if the mole gun was loaded or armed but was not fired by action of a mole or otherwise, the safety pin can be inserted into the lower hole in the bar 15 to hold in place the bar 15 and the guide plate 17 attached thereto, and then the trip plate extension 12 can be moved downward to “uncock” or disarm the mole gun by releasing the bottom tip of the latch 13 from the trip plate actuator 22 . Thereafter, the powder charge, projectiles, etc. can be safely removed; the safety pin can be removed from the bar 15 ; and the guide plate 17 returned to its released position.
[0022] As explained elsewhere in this application, when adapting or modifying a plunger- or spear-type trap to the mole gun described herein, the spring can be shortened, replaced with a weaker spring, or eliminated altogether. A reduced spring tension makes it easier to lift the guide plate 17 /impingement device 18 by only using one hand.
[0023] Within the embodiments described in this application, an explosive charge is fired (exploded) to discharge a projectile, i.e., pellet or pellets, or snake shot. The explosive charge can include gunpowder, which may be the most convenient. However, other explosive charges or expanding sources can be used, such as pneumatic air, compressed air, or compressed carbon dioxide (CO 2 ) for forcing the projectile out of the projectile bore of the mole gun. A pneumatic-air source compresses a tiny bit of air by action of a pump lever in order to obtain the internal pressure needed to power the projectile out the projectile bore barrel at a decent pace. A disadvantage of the pneumatic air source may be the additional structure necessary and all the time and effort needed to obtain the necessary internal pressure. A barrel assembly using compressed air or CO 2 can be powered by a reservoir of compressed air or CO 2 arranged within the barrel assembly. The reservoir can be replaceable and self-contained or can be rechargeable by a larger container. The arrangements used in airguns for pneumatic air, compressed air, or compressed carbon dioxide (CO 2 ) can be adapted and used as the explosive or expansive force in the barrel assembly described this application for forcing the projectile out of the projectile bore of the mole gun.
[0024] The barrel assemblies, such as shown in FIGS. 3A, 3B , and 4 , can be constructed to separately hold an explosive charge and projectile. In an alternative arrangement, such as shown in FIG. 5 , the explosive charge and the projectile can be combined together, such as in a bullet 24 . A representative barrel assembly is shown in FIG. 3A and can be made of metal or other suitable material capable of withstanding the explosive charge detonated in the explosion chamber 31 . The barrel assembly shown in FIG. 3A can be joined to the frame 10 by vertical bracket 20 and horizontal bracket 21 . The barrel assembly shown in FIG. 3A includes an explosion chamber 31 that receives an explosive charge. The explosion chamber can have a stepped configuration, such as shown in FIG. 3B , for holding an explosive charge. For example, explosion chamber 31 can be designed accept an explosive charge for nailers, such as those sold by Remington.
[0025] An exemplary embodiment is shown in FIG. 3B , where the diameter of the upper bore “D” can be 0.224, 0.231, or 0.246 inches or other, and that of the lower bore “B” can be slightly smaller than D, such as 0.156 or 0.208 inches or other. The lower bore B can have a bore or diameter smaller than that of the upper bore D for holding an explosive charge therein. The depth of the upper bore “C” (i.e., the length from the upper surface of the barrel assembly to the top of the stepped portion 34 ) can be 0.230, 0.320, or 0.625 inches or other. The depth “E” (i.e., the length from the top of the stepped portion 34 to the bottom of the lower bore) can be 0.240 inches. In other arrangements, the stepped or tapered bore 34 , as identified by dimension E in FIG. 3B , is not included and can be eliminated altogether. In such arrangements, the upper bore of the explosion chamber such as that defined by dimensions C and D, and the stepped or tapered bore such as that defined by dimensions B and E need not be present. In these arrangements, the projectile bore 32 is contiguous with and/or communicates directly with the explosion chamber 31 .
[0026] The dimensions and configurations of the explosion chamber 31 can be adapted and modified to accept or hold any kind of explosive charge or bullet. Other diameters can be used for the upper bore D and the lower bore B, and other lengths can be used for the depth C of the upper bore and the depth E of the stepped portion 34 . Such diameters and lengths can be adapted to different sized explosive charges and projectiles. For example, Remington brand is one brand of blank powder charge. These charges are the type used with nail guns or drivers used to drive anchors into concrete and steel. Another type of charge is the primer charge used in reloading shotgun shells. These primers are available from Winchester, Remington, Federal and CCI. Some designations for this type of primer are 209 , 209 M, 209 P and 209 A, depending on the manufacturer.
[0027] In the arrangements shown in FIGS. 3A, 3B , and 4 , a reduced diameter portion is provided in the projectile bores 32 . This reduced diameter portion is called a pellet stop F and can be located anywhere along the length of the projectile bore 32 . In FIGS. 3A, 3B , and 4 , a pellet stop F is provided at the end of the projectile bore 32 adjacent the explosion chamber 31 at the powder charge end of the barrel. The pellet stop F can have smaller than the diameter bore of the projectile bore 32 . For example, for a 0.177 pellet, the projectile bore 32 for the pellet can be approximately 0.177, and the bore or diameter for the pellet stop can be approximately 0.156. Of course, other diameters can be used for the projectile bore and pellet stop to accommodate different sized projectiles, such as those discussed elsewhere in this application. A purpose of the pellet stop is to hold the projectile or pellet in place when the mole gun is in the armed or cocked position, while permitting the force resulting from detonation of the explosive charge, which is held in the explosion chamber 31 and detonated by the impingement device 18 , to force the projectile out of the projectile bore with sufficient velocity for killing a mole.
[0028] The projectile bores 32 can be made of a size that accepts any caliber bullet or pellet, including those made by Crossman, Beeman, and Daisy. A representative caliber bullet or pellet is 0.17 or 0.22 caliber. The dimensions and configurations of the projectile bores 32 and pellet stops F can be adapted and modified to accept or hold any kind of projectile. Representative pellets that can be used in the mole gun described in this application include those for pellet guns and rifles that are available from several manufacturers. The manufacturers include Beemon, Gamo, Eun Jin, Daisy, and RWS. Bullets used to reload rifle cartridges and also be used. The calibers therefore can include 0.17 and 0.22 made by, for example, Homady, Winchester, CCI, Speer and Sierra. In addition, round ball buckshot pellets, for shot shell reloading, in various sizes (i.e., sized to match projectile bore 32 ) can be used in the mole gun of this application.
[0029] The effectiveness of the mole gun described in this application can be increased by including more than one projectile bore for firing multiple pellets with a single explosive charge. The effectiveness of the mole gun described in this application can be also increased by spacing the projectile bores 32 apart as shown in FIG. 4 or by arranging the projectile bores 32 to angle outwardly from a center top portion of the barrel assembly towards the side of the barrel assembly as shown in FIGS. 3A and 5 . These embodiments permit the projectiles exiting from the projectile bores 32 to penetrate a wider or longer section of the mole tunnel, thereby reducing the chances for the mole to escape being shot.
[0030] In the barrel assembly embodiments shown in FIGS. 3 and 4 , a pellet or other projectile can be inserted into the ends 33 of the projectile bores 32 and pushed or otherwise moved along the projectile bore 22 to rest on the pellet stop, which can be arranged adjacent the explosion chamber 31 . These ends 33 of the projectile bore 32 can have a diameter, shape, and/or configuration for holding a pellet of any shape or size therein, as discussed elsewhere in this application. The explosion chamber(s) 31 or the projectile bore 32 in the barrel assemblies in accordance with this application, such as those shown in FIGS. 4 and 5 , can have a shape adapted to receive a bullet or shotgun shell. In such an arrangement, the explosion chamber(s) 31 or the projectile bore 32 are configured, so the lead or front portion of the bullet or cylindrical shell shot fits snugly therein. The casing of the bullet or cap of the shotgun shell is arranged to breach or span the diameter of the top of the explosion chamber or projectile bore. As shown in FIG. 5 , a bullet 24 is mounted on the upper end of the projectile bore 32 , in such a manner. Bullet casings and shotgun caps normally include at least a portion with a larger diameter than the bullet or shell body. The embodiments of the present application include resting the casing of the bullet or cap of the shotgun shell, as well as the casing of an explosive charge, outside the explosion chamber or projectile bore. In this manner, when the impingement device 18 strikes the casing of the bullet, the cap of the shotgun shell, or explosive charge; the gunpowder or other explosive or expansive material contained therein explodes forcing the bullet, shot, or pellet out of the end 33 of the projectile bore 32 .
[0031] A spring 16 is arranged around the bar 15 and can be coaxial therewith. While a spring is shown in FIGS. 1 and 2 , any type of biasing means can be used for generating a downward movement of the guide plate 17 from the armed position to the released position, even rubber bands. The biasing means should provide sufficient downward force to the guide plate 17 , when released from the armed or set position, to cause an explosion by the guide plate (or impingement device 18 arranged thereon) impinging an explosive device arranged in the barrel assembly 19 .
[0032] In another embodiment, the spring 16 is provided that has sufficient force, so that the impingement device 18 or firing pin will ignite or detonate the explosive charge. In other embodiments, the spring can be eliminated, where the weight of the guide plate 17 , itself, or other force, is sufficient for igniting or detonating the explosive charge.
[0033] In a typical embodiment of the present application, the spring 16 forces the guide plate 17 downward, so that the impingement device 18 impacts the explosive charge contained in the explosion chamber 31 or projectile bore 32 . The impact of the impingement device 18 , such as a firing pin, with the explosive charge creates an explosion that generates downward force acting against the projectiles arranged within the projectile bores 32 (or fires bullet 24 ). The explosion occurs rapidly and forcefully to fire the bullet or projectile, so the mole has insufficient time to retreat in the tunnel and escape being shot.
[0034] In one embodiment described herein, a plunger- or spear-type trap can be adapted or modified into a mole gun in accordance with the discussions of this application. An embodiment of the present application includes parts and/or instructions, provided separately from a plunger- or spear-type trap, for adapting or modifying a plunger- or spear-type trap to a mole gun as described herein. These parts can include any of a barrel assembly 19 , an impingement device 18 , an extension plate 12 , and appropriate fasteners and supports 20 , 21 for securing these parts to a plunger- or spear-type trap. A plunger- or spear-type trap can be modified into a mole gun by removing or shortening the spikes or tines contained therein. For example, viewing the device shown in FIG. 6 , the spines 109 can be removed or shortened. Shortened spines are shown on the guide plate 17 in FIG. 2 . Additionally, a barrel assembly 19 and supports therefor 20 , 21 in accordance with the discussions of this application can be arranged between the legs 104 . Thereafter, an impingement device (i.e., firing pin) 18 can be arranged on the spear plate 106 . Such a modification can be arranged as shown in FIG. 2 of the present application. When adapting or modifying a plunger- or spear-type trap, the spring can be shortened, replaced with a weaker spring, or eliminated altogether.
[0035] In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. As various changes could be made in the above constructions without departing from the scope of the mole gun described in this application, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
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A device for exterminating molds that is arranged to fire a projectile into a mole as the mole moves within mole tunnel. The device holds an explosive charge and a projectile and is arranged in a location about the mole tunnel. The device includes a trigger that detects the presence of a mole. When the presence of a mole is detected, the explosive charge is ignited or released forcing the projectile into the mole. The device can be self-contained or include parts for adapting a spear mole trap to include a barrel assembly including an explosive charge and a projectile, and associated structures.
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[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 08/656,257, filed on Jul. 22, 1996 which is a 371 of PCT/DE94/01406 filed on Nov. 23, 1994.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a finishing device to lay and compact asphalt layers and a method for operating the device.
[0004] 2. The Prior Art
[0005] Asphalt finishers are known that consist of a receiving bucket, for the temporary storage of the hot asphaltic mixture, and conveyor belts, for the longitudinal transport of the asphalt before the laying beam. Spreader screws are provided for demixing-free transverse distribution of the mixture across the laying width and a laying beam for pre-compaction and striking off the asphalt. The laying beam is suspended on a traction vehicle in an articulated manner and floats upon the mixture to be laid.
[0006] Conventional laying beams consist of a tamping beam (tamper) and vibrating beam (screed plate).
[0007] The newer high compaction beams contain additional compacting elements in order to increase the level of pre-compaction. Depending on the effectiveness of the laying beams, rollers may be used for recompacting.
[0008] Thus, a layer is laid of the mixture in the receiving bucket in the specified thickness. The amount of compaction is a deciding factor in the mechanical properties and the durability of the asphalt. Higher compaction means a significant improvement in quality with the correct mixture conception and a suitable course structure. The continuous growth in traffic and the increase in axle loads requires a high degree of compaction.
[0009] According to German Patent No. 90 13 760.4 U1, a road building machine for renewing road surfacing is disclosed, which consists of heating aggregates of a milling unit provided with a drive unit, a mixing unit and a conveyance device, and drawing off new material from a material trough, as well as a laying unit. The conveyance device consists of two belt-conveyors arranged in tandem in the lengthways direction of the road building machine. The first conveyor belt extends from the material trough to a transfer unit disposed between the tractive machine and the trailer and the second conveyor belt extends from the transfer unit into the region of the laying units.
[0010] In the case of these finishers, the existing asphalt is heated by heating aggregates which are then reamed, distributed or fed into a mixing region and then distributed. Because the bitumen is a relatively poor heat conductor, temperatures of 300° to 600° C. or more are required to heat the approximately 4 cm thick top region. The use of these finishers working in combination with heating aggregates thus leads to significant environmentally degrading emissions, owing to large temperature differences within the asphalt. Thereby the binder is modified and the job site mixture is subject to a series of factors, which lead to considerable fluctuations in quality within a section under construction compared with production at an asphalt mix plant. In the case of these finishers, it is also disadvantageous that a certain dwell time is required to heat the lower courses, which is also dependent on the weather to a great extent. Consequently, only a low working speed is possible and the course thickness of the asphalt to be distributed or changed is limited.
[0011] The disadvantage of the known finishers is that they only enable the laying of a delivered type of asphalt mixture. Surface and binder courses are laid in relatively thin coats. Asphalt compacting depends largely upon the thermal capacity of the asphalt layer. This is closely related to the layer thickness, the weather conditions, and the temperature of the mixture as delivered on the job site.
[0012] Rapid asphalt temperature losses lead to difficulties during compacting, to insufficient bonding between layers and increased voids content diminish the quality. In numerous studies, it has been proven that there are manifold deficiencies in the compacting of relatively thin rolled asphalt surface layers. Necessitated by the sequence of construction operations, allocation of funds, and unpredictable weather influences, asphalt surfaces are often laid during unfavorable weather conditions. Raising the mixture temperature in the delivery state is subject to limits as it causes increasing oxidation of the binder, which in turn worsens the compaction ability and is generally disadvantageous. Generally, one thus strives to lower mixture temperatures rather than increasing them.
SUMMARY OF THE INVENTION
[0013] It is the object of the present invention to provide a finisher which enables high compaction of the asphalt without increasing the processing temperature and without increasing compaction expenditures.
[0014] This object is accomplished by providing a method in which the material is transported simultaneously from two separate receiving buckets attached to the machine, via two independent conveyance systems, to respective distribution devices. The distribution devices are arranged in tandem, staggered in the direction of operation, the devices deposit the material in superimposed layers and lay it.
[0015] The finisher according to the invention is provided with a receiving device for the temporary storage of the hot mixture. The receiving device consists of two separate receiving buckets, from each of which a mixture transport system with at least one conveyance device leads to the distribution devices, and the distribution devices are constructed as spreader screws.
[0016] The finisher according to the invention is advantageous over the prior art in the following ways. In practice, it has been demonstrated that when laying thicker courses, better degrees of compactness are achieved with the same technology. The finisher according to the present invention allows the simultaneous laying of two different hot mixtures directly upon each other. With the increase in layer thickness, the thermal capacity of the laid asphalt is considerably increased so that laying may even be carried out during unfavorable weather conditions.
[0017] Moreover, the finisher according to the invention enables the simultaneous laying of two supplied asphalts, different in composition, in hot work method, which are produced in an asphalt mixing plant under strictly controlled qualitative and environmentally relevant conditions.
[0018] Furthermore, it is advantageous that, through direct hot-on-hot laying, an optimum bonding between the two layers is achieved. The otherwise conventional use of asphaltic emulsions to bind the asphalts is not required. The considerably greater thermal potential also effects a better bonding with the already laid asphalt courses.
[0019] In contrast to the recycling finishers, the finisher according to the present invention enables a high working speed. The asphalt delivered from the mixing plant has fewer fluctuations and a defined temperature. Furthermore, the aforementioned hazardous emissions are avoided, as production is effected at an even and low temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.
[0021] In the drawings, wherein similar reference characters denote similar elements throughout the several views:
[0022] [0022]FIG. 1 shows a side view of the finishers for the simultaneous installation of two asphalt layers with different compositions over the entire installation width;
[0023] [0023]FIG. 2 shows a side view of the finisher for the simultaneous installation of two asphalt layers with different compositions over the entire installation width with a self-driving conveyor device for charging a bucket;
[0024] [0024]FIG. 3 shows a side view of a self-driving vehicle with a transporting belt for alternately loading the buckets with asphalt from the stationary asphalt plant;
[0025] [0025]FIG. 4 shows a side view of the finisher for the simultaneous installation of two asphalt layers with different compositions across the entire installation width, with a bucket crane for charging the buckets;
[0026] [0026]FIG. 5 shows a side view of the finisher for the simultaneous installation of two asphalt layers with different compositions across the entire installation width, with a self-driving conveyor system for loading a bucket;
[0027] [0027]FIG. 6 shows a side view of the finisher for the simultaneous installation of two asphalt layers with different compositions over the entire installation width, with two tamping beams;
[0028] [0028]FIG. 7 shows a top view of the finisher for the simultaneous installation of two asphalt layers with different compositions, with tamping beams;
[0029] [0029]FIG. 8 shows a side view of the finisher for the simultaneous installation of two asphalt layers with different compositions over the entire installation width, with asphalt in the container for loading a bucket;
[0030] [0030]FIG. 9 shows a side view of the finisher for the simultaneous installation of two asphalt layers with different compositions over the entire installation width, with loading of M 1 from a truck and loading of a bucket with a bucket crane;
[0031] [0031]FIG. 10 shows a side view of the finisher for the simultaneous installation of two asphalt layers with different compositions over the entire installation width, with receiving buckets disposed next to each other and with direct loading from a truck; and
[0032] [0032]FIG. 11 shows a top view of the finisher for the simultaneous installation of two asphalt layers with different compositions over the entire installation width, with receiving buckets disposed next to each other and with direct loading from a truck.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] Referring now in detail to the drawings, FIG. 1 shows an embodiment of the asphalt finisher according to the invention with two mixture buckets M 1 and M 2 , which are manufactured by modifying known construction systems for asphalt finishers. The finisher is extended by a frame extension RV of 1400 mm. A conveyor belt F 1 is provided for the lower asphalt layer. In addition, the basic unit is raised by 450 mm and an additional conveyor F 2 is installed for the top asphalt layer. The asphaltic material is distributed with the aid of two spreader screws VS 1 , VS 2 . A screed plate A or stripper is attached to the finisher for correct production of the thickness of the first asphalt course AS 1 . A second asphalt course AS 2 is also provided. After the first mixture type, the second mixture type is laid immediately and both layers are compacted together. A hydraulic pulling system HZ is provided for changing the weight of strut H. A tamping beam VD precompacts the two asphalt layers.
[0034] [0034]FIG. 2 shows a self-driving vehicle having a conveyor belt FE. In this case, conveyance device FE is a transport belt to charge the second mixture bucket. This system alternately loads receiving buckets M 1 and M 2 .
[0035] [0035]FIG. 3 shows the self-driving vehicle SF with conveyance device FE. An in line arrangement of a conveyor, an intermediate storage capacity is created, which guarantees that the finisher troughs can be charged continuously and ensure an even sequence of finisher operations.
[0036] [0036]FIG. 4 shows the finisher of FIG. 1 having a grab G. Grab G can be a crane and is used to load bucket M 2 .
[0037] [0037]FIG. 5 shows the finisher having a self-driving conveyor system SF for loading M 1 .
[0038] [0038]FIG. 6 shows the finisher having two tamping beams VD 1 and VD 2 . Tamping beam VD 1 is suspended from strut H 1 and tamping beam VD 2 is suspended from strut H 2 .
[0039] [0039]FIG. 7 shows a top plan view onto the finisher for placing of two asphalt layers. Two mixing-material containers M 1 and M 2 are attached at the front side. The mixed material from the container M 1 is transported to the two oppositely operating distribution worms VS 1 ′ and VS 1 ″. The cover-layer mixed material is transported from the container M 2 and the cover-layer mixed material is brought from there to distribution worms VS 2 ′ and VS 2 ″.
[0040] [0040]FIG. 8 shows the finisher of FIG. 1 incorporating a container C for loading M 2 .
[0041] [0041]FIG. 9 shows bucket M 1 of the finisher being loaded from a truck L. Loading of bucket M 2 is accomplished by bucket crane G.
[0042] [0042]FIGS. 10 and 11 show receiving containers M 1 and M 2 which are created by separating and enlarging the receiving container of a conventional finisher and are additionally stabilized laterally by the support wheels SR. The receiving containers M 1 and M 2 are directly loaded by means of trucks supplying the asphalt from the stationary mixing plant. The asphalt for the lower layer AS 1 is supplied by a truck 1 , and the asphalt for the top layer AS 2 with a second truck 2 , and the receiving buckets M 1 and M 2 are directly loaded. The asphalt for the lower layer AS 1 is transported via the conveyor system F 1 , which extends outside of receiving container M 1 offset sideways to the center of the distributor device VS 1 . The asphalt is distributed sideways and profiled and precompacted by tamping beam VD 1 . The asphalt for the top layer AS 2 is transported via the conveyor system, which extends outside of the receiving container M 2 in an ascending manner and is offset sideways to the center of the distributor device VS 2 and onto the hot lower asphalt layer. The asphalt is distributed sideways, profiled, and precompacted by tamping beam VD 2 . Final compacting of both layers is accomplished by rolls (not shown).
[0043] Direct loading from trucks into the receiving buckets M 1 and M 2 may cause knocking against the finisher and lead to uneven spots in the asphalt layer pavement. Therefore, it is possible to feed two receiving buckets M 1 and M 2 with a self-driving vehicle SF equipped with the conveyor belt FE. A drive wheel or chassis R is provided on receiving buckets M 1 and M 2 . In addition, support wheels SR are disposed on receiving buckets M 1 and M 2 . The asphalt so supplied is transported in this connection alternately into the self-driving vehicle from truck 1 or truck 2 , and the receiving containers M 1 and M 2 are subsequently loaded via the conveyor belt FE.
[0044] Accordingly, while only a few 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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This invention relates to a finishing device to lay and compact asphalt layers and a method for operating the device. The finisher according to the invention is provided with a receiving device for the temporary storage of the hot mixture. The receiving device consists of two separate receiving buckets, from each of which a mixture transport system with at least one conveyance device leads to the distribution devices, and the distribution devices are constructed as spreader screws.
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CLAIM OF PRIORITY
[0001] This Application is a continuation of U.S. patent application Ser. No. 13/490,072, filed Jun. 6, 2012, entitled PRINTING RIBBON SECURITY APPARATUS AND METHOD, which claims priority to U.S. Provisional Patent Application Ser. No. 61/493,598, filed Jun. 6, 2011, entitled RIBBON SECURITY CLEAN-UP, the contents of each of which are incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention generally relates to printing methods, more specifically, to a printing apparatus and method of providing security to desired information during a printing operation of a thermal transfer printer.
BACKGROUND
[0003] Printing systems such as copiers, printers, facsimile devices or other systems having a print engine for creating visual images, graphics, texts, etc. on a page or other printable medium typically include various media feeding systems for introducing original image media or printable media into the system. Examples include thermal transfer printers. Typically, a thermal transfer printer is a printer which prints on media by melting a portion of coating of ribbon stream so that it stays attached to the media on which the print is applied. It contrasts with direct thermal printing where no ribbon is present in the process. Typically, thermal transfer printers comprise a supply spindle operable for supplying a media web and ribbon, a print station having a printhead, and a take up spindle. During a printing operation, new ribbon and media is fed from the supply spindle to the print station for printing and then the ribbon is wound up by the take up spindle while the media is exited from the print station.
[0004] As the ribbon exits the print station it is rewound on the take up spindle. When printing sensitive information such as, for example, social security numbers, account numbers, and other similar private information, the unused portion of the ribbon will contain a negative image of the subject sensitive information. Undesirably, conventional thermal transfer printing methods provide no means of security to the information which is printed. Because the used ribbon on the take up spindle possesses a negative image of the previously printed image, the secrecy of the information printed on the media may be jeopardized.
[0005] It is therefore be desirable to provide a printing system and method which provides security means to information printed on media during a thermal transfer printing operation. It is also be desirable to provide a printing method which allows for the used ribbon of such a thermal transfer printer to be obscured such that the negative image is unable to be read.
SUMMARY OF THE INVENTION
[0006] The present invention is designed to overcome the deficiencies and shortcomings of the systems and devices conventionally known and described above. The present invention is designed to reduce the manufacturing costs and the complexity of assembly. In all exemplary embodiments, the present invention is directed to a method of securing and maintaining the integrity of desired information on a ribbon and media subsequent to a printing operation. According to aspects of the present invention, a printer is provided and generally comprises a print station having a printhead, a supply spindle for moving media through the print station and a ribbon drive assembly operable for feeding ribbon along a print path of the printer. In exemplary embodiments, the printhead is capable of being moved or lifted away from the media and ribbon subsequent to a print operation. Further, the ribbon fed through the ribbon drive assembly may be rewound a predetermined distance, thereby allowing for a second print operation on the space previously printed upon. More specifically, the used ribbon can be rewound and utilized to print a random pattern on a piece of waste media (stub) thus obscuring any previous images on the ribbon. In exemplary embodiments, the media can also be reversed a specific distance and reprinted with the used ribbon several times thus obscuring the image on the used ribbon.
[0007] If the waste media is printed on only once, the random pattern will reveal what was previously printer due to a lack of wax (ink) on the ribbon. Accordingly, in exemplary embodiments, the method steps are repeated a set number of times thereby eliminating negative images and also reducing the length of waste media required. The ribbon clean-up process can be printed after an original print operation has occurred.
[0008] Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
[0009] It is to be understood that both the foregoing general description and the following detailed description present exemplary embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the detailed description, serve to explain the principles and operations thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present subject matter may take form in various components and arrangements of components, and in various steps and arrangements of steps. The appended drawings are only for purposes of illustrating exemplary embodiments and are not to be construed as limiting the subject matter.
[0011] FIG. 1 is a perspective front view of a ribbon drive assembly utilized in the printing operation according to aspects of the present invention.
[0012] FIG. 2 is a perspective rear view of the embodiment of FIG. 1 according to aspects of the present invention.
[0013] FIG. 3 is a perspective back view of the ribbon drive assembly with a ribbon supply on the supply spindle according to aspects of the present invention.
[0014] FIG. 4 is a plan view of an exemplary printed instrument containing examples of sensitive information according to aspects of the present invention.
[0015] FIG. 5 is a plan view of the negative image remaining on a print ribbon after printing the exemplary printed instrument described in FIG. 4 according to aspects of the present invention.
[0016] FIG. 6 a is a plan view of the negative image remaining on a print ribbon described in FIG. 5 after the security method described herein is utilized employing random characters.
[0017] FIG. 6 b is a plan view of the negative image remaining on a print ribbon described in FIG. 5 after the security method described herein is utilized employing sequential Xs.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which exemplary embodiments of the invention are shown. However, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These exemplary embodiments are provided so that this disclosure will be both thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Further, as used in the description herein and throughout the claims that follow, the meaning of “a”, “an”, and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0019] In exemplary embodiments of the present invention, a printing method is provided which overcomes the shortcomings of the prior art by providing a means of security to desired information subsequent to a printing operation. The method includes the provision of a thermal transfer printer (not shown) having a supply spindle operable for supplying a media web (not shown) or ribbon, a print station (not shown) having a printhead (not shown), and a take up spindle. Those skilled in the art will appreciate that many other components may be included within the printer and many configurations may be employed. In all exemplary embodiments, during a printing operation, new or supply ribbon and media is fed from the supply spindle to the print station for printing and then the ribbon is wound up by the take up spindle while the media is exited from the print station. As the ribbon exits the print station it is wound to a take up spindle.
[0020] Referring now to the drawings and specifically, FIGS. 1-3 , a ribbon drive assembly in accordance with exemplary embodiments of the present invention is shown and generally referred to by reference numeral 10 . In exemplary embodiments, the ribbon drive assembly 10 assists in the provision of information security by being configured to rewind the ribbon supply a predetermined distance for additional print operations. In a general sense, the ribbon drive assembly 10 controls the feed of the ribbon supply 26 as it unwinds off a supply spindle 12 into a print station (not shown) and then is wound off onto a take-up spindle 14 .
[0021] In exemplary embodiments, the spindles 12 , 14 can be rotatably connected to a base plate 15 at one end and extend through a port 17 , 19 of a cover plate 13 such that their respective distal ends 21 , 23 are operative for receiving a roll of ribbon supply 26 . Each spindle 12 , 14 can be provided with an independently operated drive system comprising a plurality of gears 18 , 20 for rotating the spindles 12 , 14 , a motor 22 , 24 for driving the plurality of gears 18 , 20 , respectively, in both a clockwise or counter clockwise direction, and a rotary encoder (not shown). In exemplary embodiments, the drive system can be connected to the base plate 15 . It will be understood by those skilled in the art that it is contemplated that the motor 22 , 24 will be a DC motor, however, any type of motor suitable for powering the gears 18 , 20 and spindles 12 , 14 in a rotary movement may be employed. Further, in alternative exemplary embodiments, the motors 22 , 24 are independently operated.
[0022] The drive assembly 10 can further comprise a circuit board 16 connected to the base plate 15 having a control processor (not shown) for each motor 22 , 24 and attached to a side of the base plate 15 . The electronics of the circuit board 16 similarly can include two sets of drive components (not shown) for each spindle 12 , 14 . In exemplary embodiments, the drive assembly 10 can use a processor core (not shown) with programmable digital and/or analog functions and communication components. However, it will be understood by those skilled in the art that a variety of processors may be used. In an exemplary embodiment, the processor (not shown), motor drive IC's (not shown), opto encoders (not shown) and associated circuitry (not shown) can be located on a single board 16 of the drive assembly 10 . The processor (not shown) of the drive assembly 10 can be communicatively linked with a main processor of the printer PCB (not shown) via a SPI bus (not shown).
[0023] In exemplary embodiments, two independent control systems, one for each motor 22 , 24 , can be executed every 500 us seconds. By utilizing the independent motor system described above, subsequent to an initial print operation, the ribbon supply 26 may be rewound about the supply spindle 12 for additional print operations. Such print operations may be critical as the used ribbon oftentimes contains a reverse image of what was previously printed.
[0024] In exemplary embodiments, subsequent to the initial print operation, the print head (not shown) can be raised or lifted. Thereafter, the used ribbon 26 can be rewound a predetermined distance about the supply spindle 12 and utilized to print a random or block-out pattern on a piece of waste media (stub) thus obscuring any previous images on the ribbon 26 . In exemplary embodiments, the media can also be reversed or rewound predetermined distance and reprinted with the used ribbon 26 several times thus further obscuring the image on the used ribbon. The repeated print operations may be desirable because if the waste media is printed on only once, the random pattern will reveal what was previously printer due to a lack of wax (ink) on the ribbon. Printing on the media only once would produce a negative image of the previous image. Reversing the media several times eliminates the negative image and also reduces the length of waste media required.
[0025] Referring now to FIG. 4 , instrument 50 containing exemplary sensitive information is shown. In the exemplary embodiment, sensitive information can include, for example: a name 52 ; an address 54 ; an account number 56 ; and/or a prescription 58 . As will be appreciated by one skilled in the art, these examples are not limiting as it may be desired to protect additional forms of sensitive information.
[0026] Turning next to FIG. 5 , a drawing of a used printing ribbon 60 is shown. For purposes of illustration, the used printing ribbon 60 shown in FIG. 5 represents the used printing ribbon that would result from creating the instrument 50 depicted in FIG. 4 prior to the application of the method described herein. As is shown, the used printing ribbon 60 comprises a negative image of the sensitive information contained on the instrument 50 , such as, for example: a name 62 ; an address 64 ; an account number 66 ; and a prescription number 68 .
[0027] Finally turning to FIGS. 6 a and 6 b , drawings of used printing ribbons 60 a and 60 b are shown after the application of the method described herein. The used printing ribbon 60 a contains information that is obscured by random characters. The used printing ribbon 60 b contains information that is obscured by sequential Xs, i.e., an X-out pattern. The information obscured in FIGS. 6 a and 6 b includes, for example, names 62 a, 62 b, addresses 64 a, 64 b, account numbers 66 a, 66 b, and prescription numbers 68 a and 68 b. Alternative embodiments contemplate that other designs (not shown) and/or block-out printing (not shown) may be employed to obscure any sensitive information on the printer ribbon 60 and render it unreadable or eliminate the sensitive information from the printer ribbon 60 altogether.
[0028] Aspects according to the present invention contemplate that sensitive information will come is a plethora of forms. For exemplary purposes, such sensitive information can include: names, amounts, account numbers, addresses, memo entries, social security numbers, FEINs, ID numbers, medical information, financial information, passport numbers, draft numbers, document numbers; PINs, alphanumeric codes and any other similar information desired to be protected.
[0029] The embodiments described above provide advantages over conventional devices and associated methods of manufacture. It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Furthermore, the foregoing description of the preferred embodiment of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation--the invention being defined by the claims.
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An apparatus and method of securing and maintaining the integrity of desired information on a ribbon and media subsequent to a printing operation is provided. The apparatus and method includes a thermal transfer printer having a print station and a printhead operable for performing a printing operation. The printhead is capable of performing an initial print operation and then being raised from the media, thereby allowing the used ribbon to be rewound a predetermined distance about a supply spindle. Thereafter, a second print operation is performed on the space previously printed upon using characters, designs or block-out patterns and the used ribbon is then wound onto a take-up spindle. In exemplary embodiments, the used ribbon can also be reprinted with a waste media several times thus further obscuring the image on the used ribbon.
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BACKGROUND
[0001] The invention concerns a method of monitoring a condensate drain, and a flow sensor for detecting flow properties in a pipe and/or a fitting carrying a medium, in particular a condensate drain, and a monitoring device for monitoring at least one condensate drain.
[0002] Condensate drains are usually employed in installations in the chemical, pharmaceutical and energy-technology industries in order to drain from the installation a condensate which is formed in vapor lines or containers or in shaping processes. In that case drainage of the condensate must be effected at a given moment in time in order to prevent a so-called water hammer and to provide for effective use of energy. Such a water hammer occurs when vapor is introduced into a liquid at a lower temperature or occurs in such a liquid. In addition the condensate drain should prevent vapor from being discharged in the event that no condensate is present.
[0003] In such installations, wear phenomena, contamination and/or deposits can occur, for example, by virtue of erosion due to magnetite formation. That can result in leakages or blockages in condensate drains used in the installations. In that respect, it is not possible to see whether the condensate drain is or is not operating from the exterior, that is to say from outside the installation or the pipes and/or the condensate drain. The operability of the condensate drains used is to be checked in a method of monitoring condensate drains. In that respect, it is necessary to clearly establish whether the condensate drain is functioning in fault-free fashion and whether, in the case of faulty functioning, a leak or a blockage occurs. That is necessary as, for example, blocking condensate drains can lead to considerable reductions in the output of the installation, and leaky condensate drains result in vapor losses which in turn represent a considerable economic loss. In addition, a rise in pressure in condensate networks, that is to say in a system with a plurality of condensate drains, is to be expected. Difficulties caused thereby in regard to drainage can then occur at a number of condensate drains in the installation. In addition, there can be a condensate build-up, which can cause water hammers and can also lead to serious damage in the vapor-condensate system. Usually, a proportion of defective condensate drains of an order of magnitude of 15 to 25% is to be expected in installations without regular checking or maintenance. That failure rate can be markedly reduced by regular checks to be performed.
[0004] A number of methods of monitoring a condensate drain are already known. The condensate drains can be checked, for example, by means of sight glasses, by level measurement, and by means of sound measurement. A disadvantage with the specified methods is that the operability of the condensate drain can only be estimated.
[0005] The methods based on sound measurement rely on detection of the solid-borne sound which is emitted from the surfaces of the housings of the condensate drains. To be able to assess the operating mode of the condensate drain, the detected intensity of the solid-borne sound is shown on a display device or compared to previously recorded reference data.
[0006] In that respect, manual checking of each individual condensate drain is usually required, and that involves a great deal of time and effort in larger installations. Under some circumstances, that leads to relatively long checking intervals so that faults in the condensate drain system cannot be immediately detected and removed.
[0007] Usually mechanical contact with the condensate drain being investigated is required to detect solid-borne sound. Governed by the structure involved, the measurement results are relatively closely related to the contact pressure force and the contact pressure angle of the measuring sensor, so that any change in one of those parameters can lead to a inaccurate measurement result. In addition, the contact location must be defined as accurately as possible.
[0008] By evaluating exclusively the sound intensity in the ultrasound range, it is not possible to accurately establish whether the condensate drain is just draining or has a water hammer by virtue of damage. That case does not afford clear ascertainment of the working condition.
SUMMARY
[0009] The object of the present invention is therefore that of eliminating or at least reducing the described disadvantages. In particular, the invention seeks to provide a method of monitoring a condensate drain or suitable apparatuses for that purpose, which permits or permit different properties of the medium or the mode of operation of the condensate drain to be reliably and precisely determined.
[0010] According to the invention, therefore, there is proposed a method of monitoring a condensate drain according to claim 1 . The method includes the steps of: a) providing a flow sensor for detecting flow properties in a pipe and/or fitting carrying a medium, wherein the medium is in the form of a multi-phase flow, b) detecting a vibration behavior at a measurement location provided on a vibration body of the flow sensor by means of the vibration converter, and c) electronically evaluating the vibration behavior of a vibration body.
[0011] In that case, at the measurement location, vibrations of a first region of the vibration body, which is provided at least partially in a flow of the medium, and a second region of the vibration body, that is outside the flow, are recorded. The vibrations can be detected at the second region of the vibration body, for example by means of a piezoelectric element, laser vibrometer, or microphone.
[0012] The term condensate drain is also used hereinafter to denote a condensomat and/or a regulating fitting which drains off a condensate which forms in vapor lines or containers or shaping processes. To monitor such a condensate drain and therefore to check the operability thereof, there is provided a flow sensor for detecting flow properties in a pipe and/or fitting carrying a medium. In that case, the medium is in the form of vapor or steam, condensate, water and/or air, in particular in the form of a multi-phase flow. In that respect, the vibration body is at least partially used in a pipe cross-section and/or fitting cross-section through which the medium flows. In that case, the medium flows around the vibration body or the vibration body, which is arranged near the flow, in particular at the flow surface, so that it at least partially touches the flow. The vibration body is caused to vibrate by the flow of the medium. The vibration behavior resulting therefrom is detected by means of the vibration converter and representative signals of the vibration behavior are produced. In that respect, the detected vibration behavior includes, in particular, detection of the amplitude and frequency of the vibration. The vibration amplitude and frequency detected in that way is outputted to the measurement location by way of an electric signal of the vibration converter. In that case, the vibration converter can be, for example, of such a configuration that the vibrations are detected by a piezoelectric sensor, a microphone, or by way of a laser vibrometer.
[0013] Preferably, in accordance with a development of the method according to the invention, in-phase vibrations and out-of-phase vibrations of the two intercoupled regions of the vibration body are recorded at the measurement location. Excitation of the vibration body is preferably effected by means of the first region of the vibration body, that at least partially projects into the flow of the medium, wherein both the first region disposed in the flow and also the second region outside the flow are excited to vibrate. By virtue of an elastic coupling of the two regions of the vibration body with each other and with a main body of the flow sensor, the two regions of the vibration body perform in-phase vibrations and out-of-phase vibrations, also referred to as co-directional and counter-directional vibrations. In that case, the vibration body is designed so that the in-phase and out-of-phase vibrations occur simultaneously at different frequencies. The term co-directional vibrations or in-phase vibrations of the two regions, starting from the connecting region of the two regions of the vibration body, that preferably extend in opposite directions, are to be interpreted as meaning vibrations in which the two intercoupled regions of the vibration body move in the same direction. The term out-of-phase vibrations is to denote vibrations of the two regions in which they vibrate in opposite directions, also starting from the connecting region of the two regions of the vibration body. Preferably by frequency analysis, also referred to as spectral analysis, of the vibration behavior of the vibration body, preferably two resonance frequencies occurring in the vibration body and their amplitudes of the in-phase and out-of-phase vibrations are simultaneously detected.
[0014] By virtue of recording and analysis of the vibration behavior of the vibration body, comprising two elastically coupled regions which are preferably disposed in two different media, wherein the first region is arranged in the multi-phase flow and the second region of the vibration body is preferably arranged in the ambient air, amplitude and frequency of two resonance locations are detected. In that way, it is possible to detect mass transport processes in respect of multi-phase flows, whereby it is possible to determine the condensate level and its flow speed as well as the level of the vapor and its flow speed. Operability, pressure stage, amount of condensate and vapor loss amount of a condensate drain can be clearly ascertained by means of the stored reference data set. Ambiguous results are excluded by the combination of the amplitude and frequency of the two resonance locations. It is possible to determine the operability of the condensate drain by way of that combination or properties of the flow.
[0015] Preferably the flow sensor is provided between the pipe and the condensate drain, and is in particular connected releasably to the pipe and the condensate drain by means of a first flange associated with the pipe and a second flange associated with the condensate drain. When the flow sensor is provided at that position, it is advantageous for a foreign sound which occurs in such installations, for example originating from a condensate drain, to be so slight that it influences the measurements at that location scarcely to almost not at all. In that respect the flow sensor can be clamped, for example, between the two flanges and the two flanges can be screwed together so that the flow sensor is fixedly arranged between the two flanges.
[0016] In an embodiment to evaluate the flow behavior according to step c), reference measurements are carried out and/or data sets are produced thereby, which are used for comparison with the data measured at the measurement location. The data sets in that case are of such a nature that certain properties of the flow, such as for example the condensate amount, the loss amount, and the flow speed, are predetermined for different operating conditions. Thus, for example, when measuring amplitude and frequency, and with a given level and a mean flow speed with a given condensate amount, it is possible to infer an operating condition which is known for those regions and thus the operability of the condensate drain. The use of such a system makes it possible to effect functional checking independently of drain type. Thus, independently of the downstream-connected drain type, the system can be universally employed as a drain diagnosis system.
[0017] Preferably when monitoring a condensate drain in accordance with an embodiment for evaluation of the flow behavior in accordance with step c), on the basis of data sets produced by means of previously implemented reference measurements, the data measured at the measurement location are compared to the data sets. That permits simple, and at the same time, fast evaluation of the measured data, and reliable determination by way of the values to be ascertained in connection with the vibration behavior of the vibration body, with which it is possible to provide information about the operability of the condensate drain. The comparison between the measured data and the previously produced data sets is preferably effected by means of an electronic evaluation device in which the previously produced data sets are stored at the same time.
[0018] In a preferred embodiment the evaluation according to step c) is effected by way of an electronic evaluation device, such as, for example, an artificial neural network (ANN), fuzzy logic, channel relationships methods or principal component analyses (PCA).
[0019] A further development of the method according to the invention provides that, for evaluation of the flow behavior by means of the electronic evaluation device in accordance with step c), the amplitudes and the resonance frequencies of the detected in-phase and out-of-phase vibrations of the preferably two regions of the vibration body are determined. On the basis of the magnitude of the amplitudes and on the basis of the different resonance frequencies produced by the in-phase and out-of-phase vibrations at the vibration body, it is possible, by comparison with the data sets already ascertained, to implement an evaluation operation by which it is possible to provide information relating to given values reflecting the operating condition of the condensate drain, like, for example, operability, amount of condensate, pressure stage and vapor loss amount of the condensate drain.
[0020] Preferably, to evaluate the flow behavior in accordance with step c), the amplitudes and their resonance frequencies of the detected in-phase and out-of-phase vibrations of the two regions of the vibration body are determined by way of a frequency analysis operation, preferably a Fourier analysis. That kind of frequency and amplitude ascertainment provides a simple possible way of representing the vibrations which occur of the vibration body excited by the flow. In particular, the frequencies of the individual vibrations and their amplitudes can be advantageously ascertained by means of the Fourier analysis operation.
[0021] Preferably, upon evaluation in accordance with step c), a relationship is produced between, on the one hand, an operability, a pressure stage, a condensate amount and a vapor loss amount, and on the other hand, a resonance frequency and an amplitude, preferably two resonance frequencies and their amplitudes, at the flow sensor. The current operating condition of a drain can be ascertained by that relationship from a vibration spectrum.
[0022] In a further embodiment, the condensate level of the medium is determined by way of a dependency of the resonance frequency and amplitude of the in-phase and out-of-phase vibration on a damping. If, in the evaluation of a water-vapor flow, a change in the resonance frequency and amplitude is to be found, the condensate level can be ascertained therefrom by means of suitable evaluation. For example a change in the amplitude and a reduction in the resonance frequency of the in-phase and out-of-phase vibration, on the assumption of a constant density of the medium, signify more accentuated damping as a consequence of a rise in level in the conduit.
[0023] Preferably, the condensate level in the multi-phase flow, and damping of the medium, resulting therefrom, is determined by way of a dependency of the variation in the resonance frequency and amplitude of the in-phase and out-of-phase vibration at the vibration body. In the variation in the resonance frequency and the amplitude of the in-phase and out-of-phase vibration of the two regions of the vibration body, it is possible to deduce, in particular, a measurement in respect of the condensate level in the multi-phase flow and the damping linked thereto of the medium flowing through the fitting, which is preferably in the form of a multi-phase flow. The damping of the medium acts directly on the vibration behavior of the first region of the vibration body, which at least partially projects into the flow and thus also into the condensate. In the case of the coupled vibration body according to the invention, that action leads to a simultaneous change in amplitude and frequency of the in-phase and out-of-phase vibration of the two regions.
[0024] Preferably, a flow speed of the medium, preferably the multi-phase flow, is determined by way of a dependency of the amplitude and resonance frequency of the in-phase and out-of-phase vibration on the flow speed and/or the damping. If, for example, the amplitude of the in-phase and out-of-phase vibration rises with a constant resonance frequency, that means, on the assumption of a constant density of the medium, that the flow speed, and thus also the through-flow amount, is rising.
[0025] In a further embodiment, the pressure stage is determined by way of a dependency of the resonance frequency and amplitude of the in-phase and out-of-phase vibration on the damping. With different pressure stages, the medium changes its property and in particular its density. The damping in turn changes as a result. The respective pressure stage can be established on the basis of the dependency of amplitude and frequency on damping.
[0026] In a further embodiment, the density of the medium is determined by way of a dependency of the resonance frequency and amplitude of the in-phase and out-of-phase vibration on the damping. On the basis of the dependency of the amplitude and frequency on the damping, it is possible to establish the density of the respective medium.
[0027] Preferably, according to a development of the method according to the invention, a temperature, preferably of the medium and/or in the region of the pipe and/or condensate drain, is measured. By means of the temperature measurement it is possible to provide fundamental information relating to the operating condition or the operability of the condensate drain in connection with the data recorded at the flow sensor. By means of the temperature measurement, which is preferably effected in the region of vibration measurement, it is possible, in particular, to ascertain whether there is a congestion at the condensate drain, by virtue of a defect at the drain, or whether the condensate drain is closed. In that respect, what is crucial for determining the operating condition of the drain is the indication as to whether the ascertained temperature is falling below a given temperature range within which the condensate drain typically operates. On the basis of the measured temperature and the flow measurement, which is performed at the same time, it is preferably possible with a high degree of certainty to determine whether there is a congestion at the condensate drain or whether the installation portion is shut down.
[0028] A further aspect of the invention concerns a flow sensor for detecting flow properties in a pipe and/or fitting carrying a medium. In that case, the flow sensor comprises a main body, an opening which is arranged within the main body and which is of a flow cross-section adapted for the medium to flow therethrough, a vibration body which projects in adjacent relationship to the flow cross-section or into the flow cross-section, and a vibration converter provided on the vibration body for converting the mechanical vibrations into electrical signals. According to the invention, the flow sensor is distinguished in that the vibration body has a first region provided at least partially in the flow cross-section of the medium which is in the form of a multi-phase flow, and a second region provided outside the flow cross-section, wherein the first and second regions form a coupled system and the vibration body is adapted at the measurement location to record vibrations of the first region and the second region of the vibration body.
[0029] The main body and the vibration body are in that case connected together. Preferably, the vibration body has a first region provided at least partially in the flow cross-section and a second region provided outside the flow cross-section, wherein the first and second regions form a coupled system. The amplitude and frequency of the in-phase and out-of-phase vibration of the two regions are simultaneously detected by the coupled system at only one measurement location, preferably provided at the second region. That excludes ambiguous results and a clear association of the results is thus possible.
[0030] Preferably, the vibration body is so designed that, upon excitation of only a first region of the vibration body, which preferably at least partially projects into the flow, co-directional vibrations, also referred to as in-phase vibrations, and counter-directional vibrations, also known as out-of-phase vibrations, are produced by the two intercoupled regions of the vibration body. The in-phase and out-of-phase vibrations produced, as stated in greater detail hereinbefore in relation to the method, can be recorded at the measurement location at the second region outside the flow.
[0031] The flow cross-section is defined by the opening in the main body. It has a cross-section which only slightly influences the flow of the medium. Vibrations are excited by that flow of the medium, and they are detected by the vibration converter. The vibration body is at least partially arranged in the flow to generate the vibrations.
[0032] Preferably, the vibration body is of a bar-shaped configuration and/or the main body is annular. The bar-shaped vibration body can thus be based on general calculation theories in respect of the natural vibration of a bar. The two regions of the vibration body are preferably in the form of bending beams of preferably circular cross-section, which are fixedly connected together by way of a connecting region which is enlarged in cross-section in comparison with the two regions. Preferably, the first and second regions are so arranged at the connecting region that they can preferably vibrate unimpededly transversely relative to the direction in which they extend. In that respect the vibration body is formed and/or made in particular from a material with a high modulus of elasticity. As a result, it is stiff and is thus suitable for being caused to vibrate by the flow. It is an advantage in the case of an annular main body that it can be adapted, for example, to a pipe cross-section and can thus be integrated into any installation without any problem.
[0033] Another embodiment of the flow sensor according to the invention provides that the flow body has a mounting shoulder or collar which subdivides its two regions, and which is fixedly disposed on the main body, and is adapted to elastically couple the two regions of the vibration body to each other and to the main body. Preferably, the mounting shoulder for the vibration body is of a circular cross-section which is enlarged in diameter in comparison with the two regions of the vibration body. The mounting shoulder or collar forms the connecting region for the first and second regions of the vibration body, by way of which the vibrations can be passed to and fro unimpededly between the first and second regions. The material thickness of the mounting shoulder and its diameter are, in particular, in a predetermined relationship with the lengths and the diameters of the two regions of the vibration body, that are preferably in the form of cylindrical bending beams. As a result, upon excitation of at least one bar-shaped region of the vibration body, in particular transversely relative to the direction in which it extends, a diaphragm vibration is produced at the mounting shoulder and thus permits in-phase and out-of-phase vibration of the two interconnected regions of the vibration body.
[0034] The main body has a through passage for the vibration body, by way of which preferably a first region projects into the flow cross-section. The through passage, whose cross-section is basically larger than the region of the vibration body that at least partially projects into the flow, is in the manner of a stepped bore and has two portions of cross-sections of different sizes. The portion of larger cross-section is associated with the periphery of the main body, whereby a step with a contact surface is provided on the main body on which the mounting shoulder rests only in respect of a given proportion of its surface area. A large part of the mounting shoulder is freely vibrating, whereby diaphragm vibration is possible at the vibration body, and thus co-directional and counter-directional resonance vibrations of the regions of the vibration body can occur.
[0035] A preferred development of the vibration body provides that the vibration body has a preferably cylindrical mounting shoulder or collar, at which a respective bending beam of a preferably circular cross-section is arranged at mutually opposite sides. The vibration body has two, preferably coaxially arranged, bending beams fixedly connected together by way of the mounting shoulder or collar. The bending beams are preferably of a circular cross-section, and are arranged on mutually opposite side faces of the mounting collar or shoulder. The bending beams are preferably of equal diameters. In a preferred configuration, the diameter of the mounting shoulder or collar is about twice as large as the diameters of the two bending beams. The cylindrical mounting shoulder or collar rests with a face on a contact surface of the main body. One of the bending beams is arranged to project approximately perpendicularly at that face, and forms the first region of the vibration body, which at least partially projects into the multi-phase flow.
[0036] In a further embodiment, the diameter of the mounting shoulder or collar in relation to the material thickness of the mounting shoulder or collar is in a relationship in the region of 5 to 9, preferably in the region of 6 to 7. In addition the diameter of the mounting shoulder or collar relative to the diameter of the respective bending beam of the flow sensor is in a relationship in the region of 1.5 to 3.5. In a preferred configuration the relationship of the diameter of the mounting shoulder or collar to the diameter of the respective bending beam is in the range of between 2 and 3. Preferably the length of the respective bending beam relative to the diameter of the bending beam is in a relationship in the region of 2 to 6, particularly preferably a relationship in a range of between 3 and 4. The above-specified relationships of the dimensions of the mounting collar or shoulder and the bending beams relative to each other provides for an optimum vibration behavior of the vibration body according to the invention, and thus provides for reliably determining the measurement data to be ascertained.
[0037] In a preferred embodiment, the flow cross-section is adapted to the cross-section through which the medium flows. Adaptation of the flow cross-section avoids additional turbulence phenomena at the transitional location between the pipe conduit and the flow sensor. Thus a vibration is excited solely by the medium flowing around the vibration body in the flow sensor. Suitable adaptation of the vibration body ensures that the mode of operation of a drain is not adversely affected by the flow sensor.
[0038] Preferably, the flow sensor is adapted to carry out a method as described hereinbefore. The operability of a condensate drain can thus be monitored by means of such a flow sensor.
[0039] In addition, according to the invention, there is proposed a monitoring device for monitoring at least one condensate drain for draining off a condensate. In that case, the monitoring device includes at least one flow sensor with a vibration converter and an electronic evaluation means. The flow sensor, in particular according to one of the preceding embodiments, is releasably connected to the pipe and/or condensate drain, in particular according to one of the preceding embodiments, which is releasably connected to the pipe and/or condensate drain. In that case, the flow sensor is arranged adjacent to the pipe and/or condensate drain. Hereinafter, the reference to adjacent is used to mean that the flow sensor is arranged, for example, adjoining the pipe and/or the condensate drain, but at least in the very close proximity of or tightly thereto.
[0040] Preferably the flow sensor is arranged between the pipe and the condensate drain. In that way the recording of foreign sound, for example produced by and coming from the condensate drain, by the vibration body is avoided.
[0041] In a further embodiment, the flow sensor is releasably connected to the pipe and the condensate drain by means of a first flange associated with the pipe and a second flange associated with the condensate drain. In that way, the flow sensor can be replaced at any time simply and without complication for, for example, maintenance operations or in the event of a defect. In addition, there is no need either for an additional connecting device for fitting the flow sensor into the installation, as the flanges which are already present can be used, nor does the flow sensor have to be manually held in a predetermined position.
[0042] Preferably, the flow sensor is provided between the pipe and the condensate drain, preferably upstream of the condensate drain, and is in particular connected releasably to the pipe and the condensate drain by means of a first flange associated with the pipe and a second flange associated with the condensate drain. When providing the flow sensor at that position, which is decoupled in respect of solid-borne sound, it is advantageous that a foreign sound which occurs in such installations due for example to vibration of the pipes and/or the condensate drain is so slight that it influences the measurements at that location scarcely to almost not at all. In that case, the flow sensor can, for example, be clamped between the two flanges and the two flanges can be screwed together so that the flow sensor is arranged fixedly between the two flanges.
[0043] Another development of the monitoring device according to the invention provides that there is provided at least one temperature measuring device for detecting a temperature, preferably of the medium and/or in the region of the pipe and/or condensate drain, preferably in the region of vibration measurement. Preferably, temperature measurement is effected in the region of the condensate drain by means of the temperature measuring device, which preferably has a temperature sensor. By way of the preferably continuously queried temperature, it is possible to provide information as to whether an unwanted congestion of condensate has occurred in the region of the condensate drain by virtue of a defective component, or whether the condensate drain is closed. By means of the temperature measuring device, it is easily possible to establish whether the measured temperature is falling below a given temperature range within which the condensate drain typically operates. On the basis of the measured temperature and the flow measurement, which is performed at the same time, it is preferably possible to determine with a high degree of certainty whether there is a congestion at the condensate drain or whether that installation portion is shut down.
[0044] In a preferred embodiment, the monitoring device has an electronic evaluation device which is adapted for evaluating the signals of the vibration converter and for comparison of the incoming signals of the vibration converter of the flow sensor with a data set stored in the electronic evaluation device.
[0045] In that case, the data set comprises in particular the ascertained reference data. From that data set and the incoming signal, the electronic evaluation device acquires information about the properties of the flow and thus demonstrates the operating condition of the condensate drain. Preferably, a plurality of data sets are stored in the electronic evaluation device, which involve the relevant data like, for example, operability, condensate amount, vapor loss amount and pressure stage, preferably of all operating conditions of a drain with the associated sensor data like, for example, amplitude and frequency of the in-phase and out-of-phase vibration, and temperature. In addition, the electronic evaluation device is adapted to compare the measured data to the stored data sets. If the measured data, for example, should not exactly match a stored data set, it is possible to effect interpolating determination of the relevant data by way of the evaluation device.
[0046] Preferably, a further configuration of the monitoring device according to the invention provides that the evaluation device is a component part of an electronic control unit and/or the control unit is in signal-conducting communication with at least one energy generating device, preferably a thermogenerator, and a communication unit for data transfer. The electronic control unit is preferably coupled to an energy generating device and a communication unit, and is connected by way of a cable or wireless data connection to the flow sensor. A sensor node is preferably provided at each measurement location by means of the control unit, the energy generating device and the communication unit. Such a sensor node communicates with a portable query and output device or a stationary base station by way of the communication unit, preferably wirelessly directly and/or by way of other sensor nodes. Querying of the measurement data is possible, by way of the portable query and output device, from the various sensor nodes and display thereof. In that way it is possible to ensure reliable remote monitoring of the function of a, or also a plurality of, condensate drains. Instead of a portable query and output device, the data from the various sensor nodes can also be transferred to a stationary monitoring station by way, for example, of a data network. For example, measurement data of sensor nodes of various industrial plants at different locations can be brought together at such a monitoring station. Preferably, the energy generating device, which is preferably in the form of a thermogenerator, has associated therewith an energy storage means, by means of which it is possible to ensure a preferably constant energy supply for the electronic control unit of the sensor node.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] The invention is described in greater detail hereinafter by way of example on the basis of embodiments with reference to the accompanying Figures.
[0048] FIG. 1 shows a perspective view of a flow sensor.
[0049] FIG. 2 shows a sectional view of the FIG. 1 flow sensor.
[0050] FIG. 3 shows a further sectional view of the FIG. 1 flow sensor.
[0051] FIG. 4 shows an arrangement of a condensate drain and a flow sensor.
[0052] FIG. 5 shows a diagrammatic view of an embodiment of a monitoring device.
[0053] FIG. 6 shows a diagrammatic view of a further embodiment.
[0054] FIGS. 7 a and 7 b show a front view and a plan view of a sensor node according to the invention.
[0055] The Figures include in part simplified diagrammatic views. In part identical references are used for the same but possibly not identical elements. Various views of the same elements may be on different scales.
DETAILED DESCRIPTION
[0056] FIG. 1 shows a flow sensor 1 with a vibration body 9 and a main body 5 which is of an annular configuration. In this case, the vibration body 9 is of a bar-shaped configuration and has a first region 2 and a second region 3 . Provided in the main body 5 is a through passage 10 in which the vibration body 9 is arranged. The main body 5 has an opening 4 of a predetermined flow cross-section. The first region 2 of the vibration body 9 projects into the opening 4 .
[0057] Alternatively, the vibration body 9 can be of such a configuration that the first region adjoins the flow cross-section for the medium, that is to say is arranged adjacent to the flow cross-section, and thus at least partially touches the flow surface. The medium, such as, for example, a multi-phase flow, for example steam or vapor and condensate, flows through the predetermined cross-section 4 . The second region 3 projects from the main body 5 above the through passage 10 .
[0058] FIGS. 2 and 3 show sectional views of the flow sensor 1 . In addition to FIG. 1 , it can be seen from FIGS. 2 and 3 that the first region 2 and the second region 3 are connected together in a connecting region 7 . In this case, the connecting region 7 is of such a configuration that it was fitted through the passage 10 into the main body 5 , and rests on a contact surface 11 of a shoulder 12 in a stepped bore 6 . The first region 2 projects through the bore 6 into the opening 4 . The second region 3 projects beyond the main body 5 . The vibration body 9 has two, preferably coaxially arranged, bending beams for forming the first and second regions 2 , 3 which are fixedly connected together by way of the connecting region 7 in the form of the mounting shoulder or collar 7 ′. The bending beams are preferably of a circular cross-section and are arranged on mutually opposite side faces of the mounting shoulder or collar 7 ′. The bending beams 2 ′, 3 ′ are preferably of equal diameters. The mounting shoulder or collar 7 ′ is larger in diameter than both bending beams 2 ′, 3 ′. The cylindrical mounting shoulder or collar 7 ′ bears with a face 13 against a contact surface 11 of the main body 5 . The bending beam 2 is arranged to project substantially perpendicularly at that face 13 and forms the first region of the vibration body 9 that at least partially projects into the multi-phase flow.
[0059] FIG. 4 shows the assembly of a condensate drain 20 with a flow sensor 1 . In this case, the assembly of the flow sensor 1 with the condensate drain 20 is shown as an exploded view. The condensate drain 20 has a housing 23 . Arranged on the housing 23 are two condensate drain flanges 21 and 22 , which are usually fixed to a pipe carrying a medium. The flow sensor 1 is arranged between the condensate drain flange 22 and a pipe flange 31 provided on a pipe. A respective seal 30 is provided between the flow sensor 1 and the condensate drain flange 22 and the pipe flange. The seals 30 , the condensate drain flange 22 , the pipe flange 31 , and the opening 4 are of a cross-section of the same size. In that respect, the cross-section is precisely as large as the cross-section of a pipe connected to the pipe flange 31 .
[0060] In that way the flow properties of the medium are not altered when flowing through the opening 4 in the direction of the condensate drain 20 . Accordingly, the vibrations generated by means of the vibration body 9 are those which are excited by the flow around the latter. Those vibrations are detected by the vibration converter by way of the measuring location 8 and passed to an evaluation device for evaluation of the data contained therein. When there is a plurality of flow sensors (sensor nodes) in a condensate drain system, the data can be communicated to a central control unit (base station) and passed by the latter to a control center.
[0061] FIG. 5 diagrammatically shows a monitoring device 100 . The monitoring device 100 has two pipes 101 , a fitting 102 , and an electronic evaluation device 109 . The pipes 101 each have a respective pipe flange 103 connected to a fitting flange 104 associated with the fitting 102 , by way of a releasable connection 110 , in particular a screw means. The pipes 101 each carry a medium such as, for example, a multi-phase flow formed from vapor and water. A flow sensor 1 is arranged upstream of the respective fitting 102 in the flow direction 111 of the medium. In this case, the flow sensor 1 is clamped between the respective pipe flange 103 and the fitting flange 104 .
[0062] The flow sensor 1 detects the flow of the medium and produces signals representative of the flow behavior. The signals are passed by way of a vibration converter 112 to the electronic evaluation device 109 . The vibration converter 112 is fixedly wired or wirelessly connected to the electronic evaluation device 109 . The electronic device 109 receives the signals sent to it in an input region 105 and stores them. The electronic evaluation device 109 also stores a data set 107 containing data from reference measurements of the flow. In this case such a data set 107 contains certain properties of the flow such as, for example, the condensate level and the flow speed for various operating conditions, that is to say for drainage without water hammer and with water hammer and without drainage. The data set 107 and the data from the input region 105 are processed in a step 106 , that is to say compared together and evaluated. The precise operating condition, that is to say operability, the condensate amount, the vapor loss amount, and the pressure stage are precisely determined by the evaluation operation. In a further step, the results are outputted to a hand measuring device 108 . Alternatively they can also be passed to a base station 108 and from there to a control center. In that case, the data can be communicated from the sensor node to the hand measuring device and/or to the base station by radio. In that way, a plurality of users can monitor the operability of each of the individual fittings 102 in the system with the background of the entire system and precisely determine same at any moment in time.
[0063] FIG. 6 shows a further embodiment of a diagrammatically illustrated monitoring device 120 . The monitoring device 120 in turn has two pipes 101 , a fitting 102 , and an evaluation device 109 . The evaluation device 109 is part of an electronic control circuit 122 , which together with an energy generating device 124 , an energy storage unit 126 , a communication unit 128 , and a temperature measuring device 144 , constitutes a sensor node 130 . The sensor node is coupled in particular in a data-transfer relationship, by way of its evaluation device 109 , to the vibration converter 112 and the flow sensor 1 . Remote monitoring of the fitting 102 is guaranteed by means of the sensor node 130 . Possible defects of the fitting 102 can be detected by the remote monitoring process both at an early stage and also easily and in particular reliably. Preferably, the data detected by the flow sensor 1 is recorded by the evaluation device 109 and preferably wirelessly communicated from the control unit 122 by way of the communication unit 128 to a base station 108 or also a portable query and output device. In addition, there is provided a temperature measuring device 144 linked to the control unit for monitoring the operating condition of the fitting 102 . In the present embodiment, the temperature measuring device 144 has a temperature sensor 146 arranged on the fitting 102 .
[0064] FIGS. 7 a and 7 b show various views of the sensor node 130 . The energy generating device 124 , which is preferably in the form of a thermogenerator, has a carrier plate 132 which is preferably directly fixed with a base surface 133 to a heating body like, for example, the fitting 102 to be monitored. A Peltier element 134 is arranged at the opposite base surface 133 ′ of the carrier plate 132 . Small amounts of electrical energy which are sufficient to operate the sensor node 130 are generated by means of the Peltier element 134 due to the temperature difference occurring on both sides of the Peltier element. In addition, a cooling body 136 having a plurality of cooling ribs is arranged on the Peltier element 134 , by means of which the temperature difference at the Peltier element is increased and thus the effectiveness of the energy generating device 124 is improved. A housing 140 is arranged on the cooling body 136 by way of spacers 138 , 138 ′, within which housing are arranged the energy storage unit 126 , the control unit 122 , the temperature measuring device 144 , and the communication unit 128 , which together with the energy generating device 124 constitute the sensor node 130 . By means of the communication unit 128 ( FIG. 6 ), which in the present embodiment is in the form of a radio module 142 , data transfer is then possible to a portable query and output device 108 or to a base station 108 . From the stationary base station, the detected measurement data can be communicated to a central monitoring station which is not at the actual location of the monitoring procedure. In addition provided in the housing 140 is a temperature measuring device 144 which is coupled to a temperature sensor 146 arranged on the carrier plate.
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The present invention concerns a flow sensor for, and a method of monitoring, a condensate drain including the steps: a) providing a flow sensor for detecting flow properties in a pipe and/or fitting carrying a medium, b) detecting a vibration behavior by means of a vibration converter at a measurement location provided on the flow sensor, and c) electronically evaluating the vibration behavior of a vibration body, wherein at the measurement location vibrations of a first region of the vibration body, which is provided at least partially in or adjacent to the flow of the medium, and a second region of the vibration body, that is outside the flow, are recorded.
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CROSS-REFERENCE TO OTHER APPLICATION
[0001] This application claims priority from No. 60/269,999 filed Feb. 20, 2001, which is hereby incorporated by reference.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] The present invention relates to tools for cutting hard, non-metallic materials including abrasive wood and wood-based composites. More specifically, tools of interest include circular saws, milling cutters, routers, panel cutters and similar tools whose cutting edges can be fabricated from blanks of ultrahard polycrystalline cubic boron nitride (CBN) or the like.
[0003] Background: Woodworking Tools
[0004] Tooling for woodworking-type applications has some significant differences from the requirements of metalworking. (Many of the materials which are cut in woodworking-type applications are not merely wood, and sometimes not wood at all: particleboard and oriented-strand fiberboard, as well as non-wood polymers such as Melamine™ or other inorganic-loaded durable composites, may be encountered.) Common features of woodworking-type applications include air cooling (and associated high tooth speeds), workpiece materials with shear strengths much lower than ferrous metals, high shock loading (in many cases), and high abrasion. (Even among pure wood materials, many include microparticles of silicon dioxide, and composite materials may contain very abrasive filler components.)
[0005] Background: Carbide-Toothed Circular Saws
[0006] Cutting tools (especially woodworking tools) often use inserted teeth of a material which is harder than the hardest of steels. The most common material used for this is a “cemented carbide,” which typically includes small grains of tungsten carbide bonded into a matrix with a metal (typically cobalt). (Because the strength and hardness of the matrix are derived from the grains of tungsten carbide, such cemented carbides are often referred to simply as “carbide.”) Such “carbide” saw tips have a hardness of about 92 (Rockwell A).
[0007] Some firms manufacture only the steel bodies of circular saws, which are hardened, tempered and finished in every way except for tipping, and are then sold to other saw manufactures who specialize in carbide tipping. Other firms manufacture the complete saws including both the steel bodies and the installed tips. In either case, the same standard carbide tips are used in the fabrication of the blades. The steel bodies are normally made of high-carbon alloy tool steel, then a pocket is ground into the periphery of the saw body to accommodate the carbide tips. The tips may be ¼ to ⅜ inches long, 0.062 to 0.093 inches thick and from 0.10 to 0.375 inches wide, depending on the width of the finished saw blade.
[0008] In the woodworking industry, carbide tipped saws are typically 8 to 20 inches in diameter. Depending on their function, the 8 inch blades may have between 24 and 48 teeth, and the larger saws 60 to 100 teeth. For cutting non-ferrous metals, the number of teeth is typically between 24 and 80 for saws ranging from 8 to 18 inches in diameter. However, saws with greater tooth density (i.e. more teeth per inch) would be required to produce superior finishes and to cut thin materials.
[0009] Background: Ultrahard Cutting Tool Materials
[0010] Carbides were invented in the 1920s, and the search for better cutting materials continues to this day. In general, the ideal cutting tool surface should combine abrasion-resistance (hardness) with shock-resistance (toughness). (Of course there are many other relevant properties, including yield strength, rigidity, temperature limits, corrosion resistance in some applications, etc.) Materials which are harder than carbides are particularly interesting for woodworking applications, as well as many other applications.
[0011] In early 1970s, General Electric Company introduced a variety of Polycrystalline Diamond (PCD) cutting tool materials consisting of a layer of micron-sized diamonds integrally bonded with a carbide substrate. These man-made ultrahard crystalline and polycrystalline compounds have become readily available from commercial sources in a variety of grades, making possible tremendous advances in cutting tool design.
[0012] In practice, thin layers of PCD or CBN are bonded to a disk of tungsten carbide substrate ranging from 60 to 100 mm in diameter. The process requirements are extreme, e.g. 1300° C. and tens of thousands of atmospheres of pressure. These bonded disks, or wafers, generally have a combined thickness of around 3 to 4 mm with PCD or PCBN forming a single-sided layer 0.1 to 0.3 mm thick. The substrate face of tungsten carbide is ground flat and overall thickness is further reduced by grinding to one of several industry standard dimensions.
[0013] Then, using sophisticated computer controlled wire electrical discharge machine tools, the wafers are sliced into squares, rectangle, and round shapes dimensionally similar to standard carbide blanks and inserts. Ultimately, these “preforms” are ground into final dimensions for lathe tools or otherwise incorporated onto tool steel bodies in the same manner as carbide tips and inserts, and are sharpened by various special techniques.
[0014] The diamond layer's abrasion resistance, coupled with the carbide's strength, produced a cutting tool material that achieved a tremendous increase in machining performance over other available materials, tungsten carbide, for example. PCD is primarily used in non-ferrous metalworking applications such as copper and aluminum or to machine plastics, rubber, synthetics, and laminates. It had also found widespread use in sawing and shaping medium-density fiberboard and chipboard in the furniture industry. Unfortunately, notwithstanding is superb properties, it reacts chemically with iron and steel and cannot be used to machine any steel alloy.
[0015] Polycrystalline Cubic Boron Nitride (PCBN) is used for machining ferrous materials such as gray cast iron. PCBN is manufactured like PCD, except that a layer of cubic boron nitride crystals replace the diamond. Excellent machining results are obtained with PCBN-based tools in finish-turning work on nickel-based alloys. Because of its great hardness and wear resistance, PCBN cutting tools can be used at high cutting speeds and temperatures. In addition to higher available cutting speeds and excellent wear behavior, PCBN cutting materials achieve longer tool lives, allowing parts to be finished in a single cut, reliably attaining high accuracy over a long machining time.
[0016] Both PCD and PCBN provide major improvements over conventional carbide cermets, and it is now possible to machine substances that have previously been extremely difficult to fabricate. The most common ultrahard materials used in modern tools are polycrystalline diamond (PCD), which is 3.6 times harder than tungsten carbide, and cubic boron nitride (CBN), which is 2.8 times harder than carbide. However, the very properties of hardness and abrasion resistance that make polycrystalline tools superior cutting devices also make these tools extremely difficult to grind and finish.
[0017] Background: Cost Considerations for Ultrahard Materials
[0018] Despite their extraordinary performance, the application of these ultrahard materials is frequently limited by their high cost, which is at least ten times that of tungsten carbide. In addition, because of their extreme hardness, they can only be shaped with varying degrees of difficulty. PCD can only be ground by special diamond grinding wheels that are no harder than the PCD, and therefore, have a short service life. Other means of shaping PCD include electrodischarge machining (EDM) by either wire or shaped carbon electrode methods. Both of these methods require expensive, specialized computer controlled equipment that further adds to the cost of the tools in which they are incorporated.
[0019] The cost of polycrystalline diamond (PCD) and cubic boron nitride (CBN) are approximately the same. One might think, therefore, that absent diamond's inability to machine ferrous materials, there would be no practical use for PCBN which is less hard and less resistant to abrasion than PCB. Presumably because of the technical superiority of PCD over PCBN, no manufacturer recommends PCBN for wood, wood-composite products or plastics. Further, no toolmaker supplies tools for these applications.
[0020] Background: Grit-Surfaced (Non-Toothed) “Saws”
[0021] A common type of cutting tool is a circular blade which does not have shaped teeth at its edge, but which is simply coated with a diamond grit. Such cutting tools are commonly referred to as diamond “saws,” but in fact they do not perform the same type of material-removal action as is performed by a saw with shaped teeth. A saw with shaped teeth, when it is operating correctly, will carve off chips of material. By contrast, a grit-coated blade will have more of a scraping or abrasive action. (See generally Jim Effner, Chisels on a wheel (1992); and Peter Koch, Utilization of Hardwoods Growing on Southern Pine Sites (1985); both of which are hereby incorporated by reference.) A cutting action is greatly preferable for many applications, to produce a cleaner cut, lower temperature, and lower power requirements.
[0022] Polycrystalline Cubic Boron Nitride (PCBN) Woodworking Tools and Methods
[0023] The present inventors have discovered that PCBN cutting tips can be accurately ground with the same equipment commonly used to fabricate high quality tungsten carbide tools, with substantially the same geometries, and with only slight modifications of technique. Thus it turns out that, for woodworking applications, PCBN tooling is much more nearly analogous to carbide than to diamond. This is quite contrary to common belief in the industry, and radically changes the economics of PCBN tooling.
[0024] There are severe restrictions on tooth geometry of PCD tools, particularly the hook angle: the use of positive hook angles (as is usual with circular saws for woodworking) can cause PCD tools to chatter or to suffer fracture. (Hook angle is the angle of the leading face of the tooth: if the tooth is angled to pull workpiece material back toward the center of the blade, it is said to have a positive hook angle.) Thus use of very small or negative hook angles is necessary with PCD tools. The geometry of PCBN cutters however, can be made to very closely approximate those of proven carbide tools, i.e. positive hook angles can be used for faster and cooler cutting.
[0025] A profound advantage of PCBN over PCD in all but the largest operations, is that PCBN tools can be maintained using modified $20,000 grinding machines where PCD requires an electrodischarge machine costing ten times as much. This makes on-site or near site service feasible, reduces tool repair costs, turnaround time, and the inventory cost of spares.
BRIEF DESCRIPTION OF THE DRAWING
[0026] The disclosed inventions will be described with reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by reference, wherein:
[0027] [0027]FIG. 1 shows a circular saw blade using the novel cutting tips of the present application.
[0028] [0028]FIG. 2A shows a section of a conventional circular saw blade like that of FIG. 1, with diamond-tipped teeth set with a negative hook angle.
[0029] [0029]FIG. 2B shows a section of a circular saw blade like that of FIG. 1, with teeth having a zero negative hook angle.
[0030] [0030]FIG. 2C shows a section of the circular saw blade of FIG. 1, with cubic-boron-nitride-containing teeth set with a positive hook angle.
[0031] [0031]FIG. 3 shows an example of another cutting tool which can use teeth like those of FIG. 2C, and also shows how hook angle is measured in such tools.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiment (by way of example, and not of limitation).
[0033] At first appearance, it would appear that PCBN could not compete with PCD in the areas amenable to PCD applications. PCD is harder than PCBN and tests on certain materials show that it is less resistant wear. However, studies and experiments by the present inventors have indicated that wear due to abrasion is most important, and that wear tests of PCBN conducted on hardened steel at 600° C. are not necessarily applicable to cutting wood products where sharpness and edge retention are paramount. At this juncture we have not proved that wear characteristics of PCBN woodworking tools are inferior to PCD at all (although this is suspected from physical properties).
[0034] It turns out that most carbide tools compete with other carbide tools and not with PCD. If PCBN tools can be produced at five times the cost of carbide tools (a realistic expectation, especially if using the novel tooth configuration of Ser. No. 09/469,673, which is hereby incorporated by reference) and PCBN outlasts carbide by 20 fold, it is quite feasible to economically use PCBN tools in wood-product applications.
[0035] It has been discovered, through experimentation and field test that rotating tools (e.g. saws, shapers, and routers) tipped with Polycrystalline Cubic Boron Nitride (PCBN) cutting elements, perform extremely well in the shaping of medium-density fiberboard and chipboard material. These tools were made in the laboratory of Sheffield Saw and Tool using readily available preforms from two of the major suppliers of PCBN.
[0036] In a sample embodiment, the cutting tips are commercial carbide-backed BZN boron nitride (from GE), supplied in widths about 0.040″ over that required. The cutting tip blanks were brazed into place using a standard low-melting-point high-Ag silver solder (Handy and Harmon Eazy-Flow-3, in a sample embodiment).
[0037] Top grinding was done with a Vollmer CHC 020 machine, and side grinding was done with a Vollmer FS2A dual side-grinder. (These are machines which are normally used for grinding carbide teeth, and are NOT suitable for grinding diamond teeth.) Triple-chip tooth geometry was used in a sample embodiment, but other geometries can be used, including alternate top bevel (ATB), conical ATB, ATB/chamfer, flat, conical-flat, and trapezoidal, for example.
[0038] Both single- and dual-grit diamond wheels have been used successfully.
[0039] In a sample embodiment, diamond grit sizes from 200 to 800 grit have been used, i.e. closely comparable to those which would be used for sharpening a carbide-toothed blade.
[0040] However, a notable difference is that the feed rate must be less for grinding boron nitride-tipped cutters than for conventional carbide-tipped ones. In a sample embodiment, the feed rate was reduced to 50% of that which would be used for grinding conventional saw tooth carbides.
[0041] The hook angles of the PCBN teeth were typically set at about 5 degrees less than would be used for a positive-hook carbide tooth application. Thus for a rough ripping application, where a carbide tooth might be set at 20° or more, a PCBN tooth would be given a hook angle of e.g. 15°. (However, PCBN teeth are believed to be less economical for such applications, due to the high density of foreign objects encountered.) The key point is the PCBN teeth can be given a hook angle which is less positive than that of carbide teeth, but significantly more positive than would be possible with diamond teeth.
[0042] Performance comparison against carbide shows that the PCBN tools outperform carbide by at least a factor of 50. An accurate performance index is difficult to compute, because the lifetimes of the PCBN tools are so extremely long.
[0043] A test was also run to compare an experimental PCBN saw with a conventional PCD saw. The operator who was using a PCD saw on a trial basis complained that the force required to push the saw through the material was excessive compared to a carbide blade. No problem was experienced with a PCBN blade, probably because the hook angle was comparable to that on a carbide blade.
[0044] [0044]FIG. 1 shows a circular saw blade 110 using the novel cutting tips of the present application. As described above, the body 102 will typically be a steel plate, typically with appropriate tensioning for flatness under load. Radius R, reproduced in the following figures, will be used to show how the tooth geometry relates to the central hole 104 .
[0045] [0045]FIG. 2C shows a section of the circular saw blade of FIG. 1, with cubic-boron-nitride-containing teeth 103 A/ 103 B set with a positive hook angle. Note that the blade's radii do NOT lie in the face plane of each tooth. Preferable these teeth, as described above, include a PCBN layer 103 B on a tungsten carbide layer 103 A. The positive hook angle shown in this Figure has been slightly exaggerated for clarity, but is preferably more positive than would be used with diamond-coated teeth. Hook angles differ with different application, but, for any given application, the hook angle preferably used with the teeth of the presently preferred embodiment is more positive than that which would be used with diamond, and preferably is closer to the angle which would be used (for that application) with a carbide tooth rather than a diamond tooth.
[0046] [0046]FIG. 2A shows a section of a conventional circular saw blade, with diamond-tipped teeth set with a negative hook angle. In this example two instances of the radius R are shown, to show how the tooth face plane relates to the blade radius: note how each tooth is leaning slightly backwards (opposite to the geometry of FIG. 2C).
[0047] For clarity, FIG. 2B shows a section of a conventional circular saw blade 110 ″ in which the teeth are set with a zero negative hook angle.
[0048] [0048]FIG. 3 shows an example of another cutting tool which can use teeth like those of FIG. 2C, and also shows how hook angle is measured in such tools. The solid line is normal (perpendicular) to the cutting tooth circle (which in this example has infinite radius, i.e. is a straight line), and the dotted line shows the face plane of a tooth. In this example the teeth are set with a slight “scooping” angle, i.e. have positive rake.
[0049] Definitions:
[0050] Following are short definitions of the usual meanings of some of the technical terms which are used in the present application. (However, those of ordinary skill will recognize whether the context requires a different meaning.) Additional definitions can be found in the standard technical dictionaries and journals.
[0051] Braze: to solder with brass or other hard alloy.
[0052] Carrier Blade: a blade, typically made of steel, to which a cutting tip is attached.
[0053] Carbide: a material more commonly referred to as cemented carbide which typically includes small grains of tungsten carbide bonded into a matrix at high temperatures and pressure by another metal which is typically cobalt. The name cemented carbide comes from the fact the both the strength and hardness of the substance are derived from the compound of tungsten and carbon (WC), and another material (frequently cobalt) serves merely as a binder.
[0054] Chatter: as used herein is vibration or movement of the cutting tool engaged in the cut due to exterior forces applied against an inadequately supported cutting tip.
[0055] Cutting Tip: a material that is usually harder than steel that is attached to the tips of a carrier blade to provide a harder cutting surface. (See FIGS. 1, 2, and 3 for an illustration).
[0056] Solder: to make a tight junction of metallic sheets, piping, and the like, by the application of a molten alloy.
[0057] Tungsten Carbide: (WC), a cemented carbide which is harder than steel.
[0058] Pocket: an indention in a carrier blade shaped to receive a cutting tip. (See FIGS. 1, 2, and 3 for an illustration).
[0059] Superhard Material: any material harder than steel.
[0060] Ultrahard Materials: any material harder than tungsten carbide, including but not limited to polycrystalline diamond (PCD) and cubic boron nitride (CBN).
[0061] Modifications and Variations
[0062] As will be recognized by those skilled in the art, the innovative concepts described in the present application can be modified and varied over a tremendous range of applications, and accordingly the scope of patented subject matter is not limited by any of the specific exemplary teachings given.
[0063] For example, the described methods and geometries are not solely applicable to woodworking-type applications, but can also be applied advantageously to other applications where abrasion resistance is a high concern (such as precision machining of uncured or partially-cured ceramic structures).
[0064] It should also be noted that the disclosed inventions are applicable to manual-feed as well as to automatic grinding machines.
[0065] Note also that, although woodworking applications are preferred, boron nitride teeth can also cut ferrous materials (unlike diamond teeth).
[0066] None of the description in the present application should be read as implying that any particular element, step, or function is an essential element which must be included in the claim scope: THE SCOPE OF PATENTED SUBJECT MATTER IS DEFINED ONLY BY THE ALLOWED CLAIMS. Moreover, none of these claims are intended to invoke paragraph six of 35 USC section 112 unless the exact words “means for” are followed by a participle.
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Cubic boron nitride tooling, e.g. for woodworking, is fabricated with the same geometries and machinery as is used for fabricating conventional carbide tooling.
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FIELD OF THE INVENTION
The present invention relates generally to semiconductor integrated circuit processing, and more specifically to an improved method of forming a contact in an integrated circuit.
BACKGROUND OF THE INVENTION
As feature sizes and device sizes shrink for integrated circuits, relative alignment between interconnect layers becomes of critical importance. Misalignment can severely impact the functionality of a device. Misalignment beyond certain minimum tolerances can render a device partly or wholly inoperative.
To insure that contacts between interconnect layers are made properly even if a slight misalignment occurs during masking steps, extra space is usually included in a design around contacts and other conductive features. This extra retained space is known as enclosure and results in the well known “dogbone” structure. Enclosure sizes of up to a few tenths of a micron are typical for 0.5 to 1.0 micron feature sizes.
Enclosure requirements are not consistent with the continued shrinkage of devices. Enclosure is not related to device functionality, but is due primarily to limitations in photolithography alignment capability and is used to insure that misalignment errors do not cause problems with the device. When designing devices having minimum feature and device sizes, minimizing enclosure requirements can significantly impact the overall device size.
Self-alignment techniques are generally known in the art, and it is known that their use helps minimize enclosure requirements. However, the use of self-alignment techniques has been somewhat limited by device designs in current use.
Conventional MOS FET devices are typically comprised of a gate electrode overlying a channel region and separated therefrom by a gate oxide. Conductive regions are formed in the substrate on either side of the gate electrode and the associated channel to form the source and drain regions. However, the majority of the area required for the source and drain regions is a function of the design layout and the photolithographic steps required, for example, to align the various contact masks and the alignment tolerances.
Conventionally, an MOS transistor is fabricated by first forming the gate electrode and then the source and drain regions, followed by depositing a layer of interlevel oxide over the substrate. Contact holes are then patterned and cut through the interlevel oxide to expose the underlying source and drain regions. A separate mask is required to pattern the contact holes. This separate mask step further requires an alignment step whereby the mask is aligned with the edge of the gate electrode which is also the edge of the channel region. There is, of course, a predefined alignment tolerance which determines how far from the edge of the gate electrode will be the minimum location of the edge of the contact. For example, if the alignment tolerance were 1 micron, the contact wall on one side of the contact would be disposed one micron form the edge of the gate electrode and the other side of the contact would be one micron from the edge of the nearest structure on the opposite side thereof, such as another conductive contact or interconnection line. In this example, the alignment tolerance would result in a source and drain having a dimension of two microns plus the width of the contact. The overall width is therefore defined by alignment tolerances, the width of the conductive interconnection and the minimal separation from adjacent structures. A significant amount of surface area is thus dedicated primarily to mask alignment causing a substantial loss of real estate when designing densely packed integrated circuits.
When MOS devices are utilized in a complementary configuration such as CMOS devices, the additional space required to account for alignment tolerances becomes even more of a problem. This space requirement is due to the fact that CMOS devices inherently require a greater amount of substrate and surface area than functionally equivalent P-channel FET devices.
This size disadvantage is directly related to the amount of substrate surface area required for alignment and processing latitudes in the CMOS fabrication procedure to insure that the N- and P-channel transistors are suitably situated with respect to P-well formation. Additionally, it is necessary to isolate N- and P-channel transistors from each other with fixed oxide layers with an underlying channel stop region. As is well known, these channel stops are necessary to prevent the formation of parasitic channels or junction leakage between neighboring transistors. Typically, the channel stops are highly doped regions formed in the substrates surrounding each transistor and effectively block the formation of parasitic channels by substantially increasing the substrate surface inversion threshold voltage. Also, they are by necessity the opposite in conductivity type from the source and drain regions they are disposed adjacent to in order to prevent shorting. This, however, results in the formation of a highly doped, and therefore, low reverse breakdown voltage, P-N junction. Of course, by using conventional technology with the channel stops, there is a minimum distance by which adjacent transistors must by separated in order to prevent this parasitic channel from being formed and to provide adequate isolation.
It would be desirable to have a planar integrated circuit having contact openings that meet design rule criteria while minimizing distances between the contacts and nearby active areas and devices.
It is therefore an object of the present invention to provide a method of forming improved contact openings between active areas and devices for scaled semiconductor devices.
It is a further object of the present invention to provide minimum contact enclosure for the contacts to the active areas.
It is a further object of the present invention to provide a method of forming the contact openings whereby the junction leakage is minimized and the device integrity is maintained.
It is yet a further object of the present invention to provide a method of increasing the planarity of the surface of the wafer thereby minimizing subsequent step coverage problems.
Other objects and advantages of the present invention will be apparent to those of ordinary skill in the art having reference to the following specification together with the drawings.
SUMMARY OF THE INVENTION
The invention may be incorporated into a method for forming a contact opening of a semiconductor device structure, and the semiconductor device structure formed thereby. The process includes in a first embodiment, forming a first conductive structure over a portion of the integrated circuit. A thin dielectric, preferably an undoped oxide layer, is formed at least partially over the first conductive structure. A thick film is formed over the thin dielectric layer having a relatively high etch selectivity to the thin dielectric layer. The thick film is patterned and etched to form a stack over the first conductive structure. An insulation layer is formed over the thin dielectric layer and the stack wherein the stack has a relatively high etch selectivity to the insulation layer. The insulation layer is etched to expose an upper surface of the stack. The stack is then etched, isotropically or anisotropically, forming an opening in the insulation layer and exposing the thin dielectric layer in the opening. The thin dielectric layer is then etched in the opening exposing the underlying first conductive structure.
An alternative embodiment provides for a second conductive structure spaced a minimum distance away from the edge of the contact opening to meet design criteria and to insure proper electrical isolation. The second conductive structure is surrounded by a capping layer, preferably an oxide layer, to insure that the minimum distance between the edge of the second conductive structure and the edge of the contact in the opening is met. The thin dielectric layer and the capping layer will maintain the required distances between devices thus tolerating any misalignment of the contact openings.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, and further objects and advantages thereof, will best be understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
FIGS. 1-7 are cross-sectional views of the fabrication of a semiconductor integrated circuit according to one embodiment of the present invention.
FIGS. 8-12 are cross-sectional views of the fabrication of a semiconductor integrated circuit according to an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The process steps and structures described below do not form a complete process flow for manufacturing integrated circuits. The present invention can be practiced in conjunction with integrated circuit fabrication techniques currently used in the art, and only so much of the commonly practiced process steps are included as are necessary for an understanding of the present invention. The figures representing cross-sections of portions of an integrated circuit during fabrication are not drawn to scale, but instead are drawn so as to illustrate the important features of the invention.
Referring now to FIGS. 1-7, a preferred embodiment of the present invention will now be described in detail. FIG. 1 illustrates, in cross-section, a portion of an integrated circuit that has been partially fabricated. According to the example described herein, the present invention is directed to forming a contact opening which meets design criteria as such contacts are generally the most sensitive to the misalignment and design rules for spacing as described above. In addition, the present invention is further directed to increasing the planarity of the overall surface. FIG. 1 illustrates a portion of a wafer which has a surface at which isolation structures and devices in adjacent active areas are to be formed. As shown in FIG. 1, an integrated circuit is to be formed on a silicon substrate 10 . It is contemplated, of course, that the present invention will also be applicable to the formation of other contacts, including, for example, contacts between metallization and polysilicon.
The silicon substrate may be p- or n-doped silicon depending upon the location in the wafer where the isolation and active devices are to be formed. The structure of FIG. 1 includes silicon substrate 10 , into a surface of and above which is a field oxide region 12 for separating active regions or devices. Various active devices may be formed on or in the surface of the substrate as well as overlying the field oxide region 12 . In a particular application, a gate electrode 14 , formed from a first layer of polysilicon 18 , is shown overlying a gate oxide 16 . As is known in the art, typically gate electrode 14 will have sidewall oxide spacers 20 , lightly doped drain regions 22 , 24 and source and drain or diffused regions 26 , 28 . Also from the first polysilicon layer may be formed an interconnect 30 having sidewall oxide spacers 32 , 24 as is known in the art. Interconnect 30 typically will at least partially overlie field oxide region 12 .
The diffused or active region 28 is formed of opposite conductivity type from that of substrate 10 . For example, substrate 10 may be lightly doped p-type silicon and diffusion region 28 may be heavily doped n-type silicon. Of course, as noted above, other structures (with the same or opposite conductivity type selection) may alternatively be used; for example, substrate 10 may instead be a well or tub region in a CMOS process, into which diffusion or active region 28 is formed. In the example of FIG. 1, diffusion 28 is bounded by field oxide region 12 , formed in the conventional manner. In this example, diffusion 28 is relatively shallow, such as on the order of 0.15 microns, as is conventional for modern integrated circuits having sub-micron feature sizes. As such, diffusion 28 may be formed by ion implantation of the dopant followed by a high-temperature anneal to form the junction, as is well known in the art. Alternatively, the ion implantation may be performed prior to the formation of subsequent layers, with the drive-in anneal performed later in the process, if desired.
In the present invention, a thin conformal dielectric layer 38 is deposited over the wafer surface overlying diffusion 28 , field oxide region 12 and other already formed devices such as gate electrode 14 and interconnect 30 . Layer 38 may be an undoped oxide layer preferably deposited at low temperatures, for example, between 250 to 700° C. by chemical vapor deposition to a depth of about 500 to 1500 angstroms. A thick film 40 is deposited over the conformal dielectric layer 38 . Thick film 40 is preferably polysilicon or other material having a relatively high etch selectivity over the underlying conformal dielectric layer 38 . For purposes of illustration, thick film 40 will be referred to as polysilicon layer 40 and is preferably deposited to a thickness of about 10,000 to 15,000 angstroms.
Referring now to FIG. 2, polysilicon layer 40 is patterned and etched to form polysilicon stacks 42 , 44 . These polysilicon stacks are formed at locations where contacts are to be made to underlying regions such as interconnect 30 and source/drain or diffused region 28 .
Referring to FIG. 3, dielectric layer 46 is formed over the thin conformal dielectric layer 38 and over the polysilicon stacks 42 , 44 . Dielectric layer 46 is preferably borophosphorous silicate glass (BPSG) or other dielectric material which has a relatively high etch selectivity to the polysilicon stacks 42 , 44 as well as the conformal dielectric layer 38 . Dielectric layer 46 is formed for purposes of electrically isolating overlying conductive structures from all locations except where contacts are desired therebetween, for example where the polysilicon stacks are located over such regions as diffused area 28 and interconnect 30 . Dielectric layer 46 preferably has a thickness of about 10,000 to 15,000 angstroms.
Referring to FIG. 4, dielectric layer 46 is etched to expose an upper surface of the polysilicon stacks 42 , 44 . If BPSG is used as dielectric layer 46 , using a wet etch process with the etch rate of the BPSG over the polysilicon stacks of about 50:1 will allow an etch back of the dielectric layer 46 until the upper surface of the polysilicon stacks is reached or may allow for the BPSG layer to be etched below the upper surface of the polysilicon stacks to insure that the stacks are fully exposed. Other materials, etch ratios and etch chemistries may be used to achieve a similar result, for example, chemical/mechanical polishing of dielectric layer 46 may result in a relatively planar etch back exposing the upper surface of the polysilicon stacks 42 , 44 . An additional alternative may be to form a composite dielectric layer 46 by forming spin-on-glass over the BPSG and partially etching the spin-on-glass and BPSG at a 1:1 etch ratio until the upper surfaces of the polysilicon stacks are exposed. Various etch back techniques known in the art such as those described above will accomplish the desired result of partially planarizing the structure and exposing the upper surface of the stacks.
Referring to FIG. 5, the polysilicon stacks 42 , 44 are selectively etched by isotropic or anisotropic etching. The etch chemistry used will etch the polysilicon or other material used for the stacks at a high etch rate over the etch rate for the dielectric layer 46 . Contact openings 48 and 50 will thus be formed through the dielectric layer 46 where the polysilicon stacks were formed, in this example, over diffused region 28 and interconnect 30 . The thin conformal dielectric layer 38 acts as an etch stop during the polysilicon stack etch step to prevent the underlying active areas and devices from being etched away. In addition, conformal dielectric layer 38 helps to maintain the distance between the edge of the contact opening and the neighboring devices, thus maintaining required distances between devices and insuring device integrity as will be more fully described below with reference to an alternative embodiment.
The thin conformal dielectric layer 38 is next etched from the contact openings 48 , 50 exposing the active regions or devices in the contact openings. The conformal dielectric layer 38 is preferably removed by anisotropic etching to maintain the vertical dimensions or width of the contact opening. In addition to the etch back of the dielectric layer 46 , the dielectric or BPSG may be reflowed before or after etching the polysilicon stacks to increase the planarity of the dielectric layer.
Referring to FIG. 6, the polysilicon stacks were preferably patterned to have a width smaller than the width of the underlying active devices or regions, in this example, having a width of about 4000 angstroms. Thus, some misalignment of the polysilicon stacks over the active areas and devices can be tolerated. In the present example, opening 50 is shown as misaligned over diffused region 28 toward the field oxide region 12 . If this misalignment occurs over this active area, a portion of the field oxide region 12 at location 52 may be removed when the conformal dielectric layer 38 is removed from the contact opening 50 possibly reducing the area of contact between an overlying conductor and source/drain region 28 . In addition, encroaching into the field oxide may also increase potential junction leakage problems. The stack may also be misaligned over the interconnect whereby it opens over one of the sidewall oxide spacers or it may open over the interconnect line and both sidewall oxide spacers. In order to offset these problems, a thin layer of polysilicon 54 may be deposited on the dielectric layer 46 and in the openings 48 and 50 . Polysilicon layer 54 is preferably deposited to a thickness which will permit filling the openings later with a conductive material to form an interconnect to the underlying active areas or devices, for example, if the opening is approximately 4000 angstroms, polysilicon layer 50 may be deposited to a thickness of about 1000 angstroms. Polysilicon layer 54 may then be doped to help prevent junction leakage if a misalignment occurs. Polysilicon layer 54 is doped with a similar dopant as the diffused region 24 , such as by ion implantation or other suitable method. For example, if the source/drain region 28 has previously been doped with an N+ dopant such as arsenic, then polysilicon layer 54 may be doped with an N+ dopant such as phosphorous. As the polysilicon layer 54 is doped, dopants will diffuse into the substrate to some predetermined depth 56 based upon the dopant concentration and energy level. Doped region 56 will help to heal the junction region and prevent junction leakage.
Referring to FIG. 7, a conductive layer is formed over the polysilicon layer 54 , patterned and etched as known in the art to form conductive contacts 58 , 60 to the active areas and devices. Polysilicon layer 54 will typically be patterned and etched at the same time as the conductive contacts. Contacts 58 , 60 may typically be aluminum, tungsten or other suitable contact material. The present invention provides for a contact opening which tolerates misalignment or oversized contact openings and insures device integrity by healing junction exposures. In addition, the thick film and polysilicon stacks provide for a more planar structure.
Referring now to FIGS. 8-12, an alternative embodiment of the present invention will now be described in detail. FIG. 8 illustrates, in cross-section, a portion of an integrated circuit that has been partially fabricated. According to the example described herein, the alternative embodiment of the present invention is also directed to forming a contact opening which meets design criteria but which is further capable of tolerating the sensitive misalignment problems and design rules for spacing as described above. FIG. 8 illustrates a portion of a wafer which has a surface at which isolation structures and devices in adjacent active areas are to be formed. As shown in FIG. 8, an integrated circuit is to be formed on a silicon substrate 70 . It is again contemplated that the alternative embodiment will also be applicable to the formation of other contacts.
As described above with reference to the preferred embodiment, the silicon substrate may be p- or n-doped silicon depending upon the location in the wafer where the isolation and active devices are to be formed. The structure of FIG. 8, includes silicon substrate 70 , into a surface of and above which is a field oxide region 72 for separating active regions or devices. Various active devices may be formed on or in the surface of the substrate as well as overlying the field oxide region 12 . In a particular application, a gate oxide layer 74 is formed over the substrate and field oxide region. A doped polysilicon or polycide layer 76 is formed over the gate oxide layer as is known in the art. An undoped dielectric layer 78 such as oxide is formed over the polysilicon layer 76 .
Referring to FIG. 9, these three layers 74 , 76 , 78 are patterned and etched to form interconnect 80 and gate electrode 88 as is known in the art. As is described above, typically gate electrode 88 will have gate oxide 90 , doped polysilicon layer 92 , sidewall oxide spacers 96 , lightly doped drain regions 97 and source and drain or diffused regions 98 . In addition, in this example, gate electrode 88 will also have a capping layer 94 formed from the undoped oxide layer 78 . Also from the first polysilicon layer may be formed interconnect 80 having a doped polysilicon layer 82 and sidewall oxide spacers 84 as is known in the art. Also, in this embodiment is shown a capping layer 86 formed from the undoped oxide layer 78 . Interconnect 80 typically will at least partially overlie field oxide region 72 . Capping layers 86 , 94 will preferably have a thickness of about 1500 to 2000 angstroms.
Similar processing steps will now be shown as described above with reference to the preferred embodiment. A thin conformal dielectric layer 100 is deposited over the wafer surface overlying diffusion region 98 , field oxide region 72 and other already formed devices such as gate electrode 88 and interconnect 80 . Conformal dielectric layer 100 is preferably an oxide layer deposited to a thickness of about 500 to 1500 angstroms. It is important, as will be discussed in detail below, that conformal dielectric layer 100 have a thickness less than the thickness of the capping layers 86 , 94 . A thick film 102 is deposited over the conformal dielectric layer 100 . Thick film 102 is again preferably polysilicon or other material having a relatively high etch selectivity over the underlying conformal dielectric layer 100 and is preferably deposited to a thickness of about 10,000 to 15,000 angstroms.
Referring now to FIG. 10, for ease of illustration of the alternative embodiment, only a contact to the source/drain or diffused region 98 will be illustrated. Contacts to other active regions or devices, is of course, contemplated. Polysilicon layer 102 is patterned and etched to form a polysilicon stack 104 . Dielectric layer 106 is formed over the thin conformal dielectric layer 100 and over the polysilicon stack 104 . As described above, dielectric layer 106 is preferably borophosphorous silicate glass (BPSG) or other dielectric material which has a relatively high etch selectivity to the polysilicon stack 104 as well as the conformal dielectric layer 100 . Dielectric layer 106 will electrically isolate the overlying conductive structures from all locations except where contacts are desired therebetween.
Referring to FIG. 11, dielectric layer 106 is etched to expose an upper surface of the polysilicon stack 104 . Various etch back techniques known in the art such as those described above will accomplish the desired result.
Referring to FIG. 12, the polysilicon stack 104 is etched by isotropic or anisotropic etching forming a contact opening 107 through the dielectric layer 106 . Polysilicon stack, in this example, is shown misaligned in the opposite direction over the source/drain region 98 and is partially aligned over the gate electrode 88 . The thin conformal dielectric layer 100 is also etched from the contact opening 107 exposing the active area 98 in the contact opening. The conformal dielectric layer 100 is preferably removed by anisotropic etching to maintain the vertical dimensions or width of the contact opening. If misalignment of the gate electrode occurs in one direction and the contact opening is misaligned in the opposite direction, a cumulative error results. This error must be accounted for by providing additional space between the edge of the gate electrode and the edge of the active area. If misalignment occurs, a portion of the capping layer 94 or sidewall oxide spacer 96 may be removed at the same time that the conformal dielectric layer 100 is etched in the opening 107 .
In this example, any misalignment of the contact opening 107 may decrease the contact space between the edge 109 of gate electrode 88 and the edge 111 of the contact opening 107 . Due to the misalignment of the contact opening, in this example, effectively opening over the sidewall spacer 96 , the distance between these active areas may be reduced enough such that the design rules for a metal contact space to gate cannot be tolerated to insure device integrity. Thus, the thickness of the capping layer 94 will insure that the required distance between the devices in order to maintain device integrity will be met. However, the thickness of the capping layer 94 must be greater than the thickness of the conformal dielectric layer 100 and thick enough that if the conformal dielectric layer 100 is overetched there will still remain enough capping layer to insure that design rules are met. In this example, the capping layer is about 1500 to 2000 angstroms while the conformal dielectric layer is about 1000 to 1500 angstroms.
As in the preferred embodiment, a polysilicon layer 108 may then be deposited to a thickness of about 1000 angstroms on the dielectric layer 106 and in the opening 107 . Polysilicon layer 108 may then be doped to help prevent junction leakage. As the polysilicon layer 108 is doped, dopants will diffuse into the substrate to some predetermined depth 110 . Doped region 110 will heal the junction region and prevent junction leakage. A conductive layer is then formed over the polysilicon layer 108 , patterned and etched along with polysilicon layer 108 as known in the art to form a conductive contact 112 to the active area 98 .
By adding the capping layer, opening the contact becomes a self-aligned feature such that the contact opening is now self-aligned to the gate. This self-aligned process can eliminate the conventional “dogbone” structure or larger enclosure needed, thereby increasing the density of devices on the integrated circuit. This process can also be used for other layers to eliminate the “dogbone” features and minimize the required design rules. As described above, in addition to the self-aligned benefit of the present invention, a more planar structure with high integrity junctions are achievable.
Although the preferred embodiment has been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
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A method is provided for forming an improved contact opening of a semiconductor integrated circuit, and an integrated circuit formed according to the same. Planarization of the semiconductor structure is maximized and misalignment of contact openings is tolerated by first forming a conductive structure over a portion of a first body. A thin dielectric layer is formed at least partially over the conductive structure. A thick film, having a high etch selectivity to the thin dielectric layer, is formed over the dielectric layer. The thick film is patterned and etched to form a stack substantially over the conductive structure. An insulation layer is formed over the thin dielectric layer and the stack wherein the stack has a relatively high etch selectivity to the insulation layer. The insulation layer is etched back to expose an upper surface of the stack. The stack is then etched to form an opening in the insulation layer exposing the thin dielectric layer which acts as an etch stop during the stack etch process. The thin dielectric layer is then etched in the opening to expose the first conductive layer. A conductor is then formed in the opening contacting the underlying conductive structure. The thin dielectric under the insulation layer and on the sides of the opening near the conductive structure will increase the distance and help to electrically isolate the conductor at the edge of the contact opening from nearby active areas and devices.
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BACKGROUND OF THE INVENTION
This invention relates to industrial glass molding.
The art of industrial glass molding has focused upon high speed, constant operation, single article glass molding apparatus. This focus has been to the exclusion of lower speed, intermittently operating apparatus for custom article manufacture. High speed equipment is unsuitable for such manufacture, because the equipment requires too many molds; lacks adaptability to differing types of molds, numbers of molds, and molding techniques; is complex to the point of prohibitive cost; too large; and immobile. Custom article glass molding has been left to manual equipment.
SUMMARY OF THE INVENTION
An object of the inventors in making this invention was to fill the need of custom glass article manufacture for a versatile, mobile, and relatively low cost molding apparatus.
Another object of the inventors was to provide a semi-automatic molding apparatus capable, if desired, of essentially automatic, higher than manual speed operation, and yet also capable, if desired, of essentially manual, individual article molding operation.
Thus, the invention is, in a principal aspect, a variable index molding press comprising a mold table rotatably mounted on a base, selectable molding mechanisms, table drive means and index control means. The table includes a plurality of circumferentially spaced mold positions for locating from one to a plurality of molds of a plurality of types thereon. The selectable molding mechanisms are readily selectable for cooperating successively with from one to all of the molds on the table, at a molding station. The table drive means drivably rotates the table, and the index control means controls the drive means for selectively, successively indexing from one to all of the mold positions on the table to the molding station.
With the apparatus as described, selected and only selected molds may be indexed to the molding station. Selected types of molding may be accomplished at the molding station, in substantially any order and number desired.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the preferred molding press, with pneumatic and electrical control lines removed and portions cut away, to reveal detail;
FIG. 2 is a plan view of the preferred molding press, with the lines removed and other portions cut away to reveal detail;
FIG. 3 is a section view of the preferred molding press, taken along line 3--3 of FIG. 2;
FIG. 4 is a partial section view in the opposite direction of FIG. 3 along line 3--3;
FIG. 5 is a first schematic view of the controls of the preferred molding press;
FIG. 6 is a second schematic view of the controls of the preferred molding press; and
FIG. 7 is a third schematic view of the controls of the preferred molding press.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the preferred embodiment of the present invention is a variable index molding press generally designated 10. A base 12, including a sub base 14, is supported on wheels 16. Thus, the press 10 is movable to automatic gob or charge feeding equipment, or elsewhere wherever desired.
An upright, central shaft 18 is bearing mounted on the sub base 14, as shown in FIG. 3. As best seen in FIG. 1, a horizontally oriented bull gear 20 rotates around the shaft 18. The bull gear 20 is driven by a pinion gear 22, located atop a gearbox 24. An electric drive motor 26 drives the gearbox 24, and thereby the pinion gear 22, bull gear 20, around central shaft 18. A rotary encoder 28 atop the base 12 reads the position of the shaft of the pinion gear 22.
A horizontally oriented, circular mold table 30 is mounted around shaft 18, above the base 12. The table 30 is rotatable around the shaft 18, and thereby driven by the drive motor 26. The table 30 includes a plurality, specifically twelve, of mold locations defined by mold receiving openings 32. The mold locations are circumferentially spaced about the table 30, at equal radii from the shaft 18 and at equal arcs thereabout. The mold openings 32 are adapted to receive a plurality of molds of a plurality of types for a plurality of articles. Each opening 32 receives one mold at a time. For clarity, one such mold, a spinning mold 34, is shown only in FIG. 1.
As should now be evident, the mold table 30 is adapted to receive from one to a plurality of molds, of the types, number, sequence and spacing desired. As a first example, if desired, only one spinning mold 34 may be located on the table 30. As another example, if desired, six spinning molds may be placed on the table 30 at every other mold position. As a third example, if desired, six spinning molds and six plunger molds may be placed on the table 30, with each spinning mold followed by a plunger mold and another spinning mold.
Referring to FIG. 1, two alternate, or selectable, molding mechanisms are provided by the press 10 at a molding station. Referring to FIGS. 1-3, the first such mechanism includes a press head 36 adjustably mounted to a shaft of a press head drive cylinder 38. The drive cylinder 38 is mounted atop a press head tower 40, comprising two spaced, base mounted, guide rods 42, 44 supporting a cross member 46, further supported atop the central shaft 18. The drive cylinder shaft is vertically movable, to advance and retract the press head 36, and any plunger thereon (none is shown) toward and away from any mold positioned therebelow. A guide member 48 slides along the guide rod 42, guiding the reciprocating motion of the press head 36. During extreme advancement of the press head 36, any plunger thereon cooperates with any plunger mold below the press head, at the molding station, to form an article of a charge in the mold. Fixed braces 50 on the guide rods 42, 44 support the mold station portion of the table 30 during plunger molding.
Referring to FIGS. 1 and 4, the second molding mechanism is a mold spinning mechanism including a mold spinning motor 52 supported on the sub base 14 between the guide rods 42, 44. The motor 52 drives a mold spinner 54 through pulleys 51, 53 and a belt 55 within a belt guard 56. The spinner 54 is mounted on the base 12 below the press head 36. A vertically oriented shaft 58 is splined within the spinner 54 and driven vertically by a spinner lifting cylinder 60 through a link 62. A driving clutch member 64 is mounted atop the shaft 58. When lifted, the member 64 engages a driven clutch member 66 on the mold 34. The spinning motion of the spinner 54 then spins the mold 34. When released, the mold 34 continues to spin from momentum.
Opposite the molding station, a mold-article separator mechanism defines a separating station on the press 10. The separator mechanism is accompanied by a brake mechanism including a caliper brake 68, as in FIG. 1 only, for seizing a brake disc 70 of the spinning molds 34, shown in FIG. 4. The separator mechanism, also known as a kick-up mechanism, includes a retractable separating pin 72, best shown in FIG. 3, driven by a cylinder 73, for entering a mold and lifting an article therein, to separate the article from the mold.
As seen in FIG. 2, a locating mechanism is on the base 12 between the separator station and the molding station. The locating mechanism precisely locates the table 30 relative to the base 12, for accurate registration between the molding mechanisms and the molds. A retractable locating pin 74 selectively enters precision made pin openings (not shown) in the underside of the table 30. A locator pin opening is provided for and corresponds to each mold position of the table 30.
The locator mechanism, separator mechanism, and the plunger molding mechanism are pneumatically driven. A bank 75 of electropneumatic controls actuate the mechanisms through pneumatic connections (not shown).
All the aforesaid mechanisms, the mold spinning mechanism, and the table drive are electronically controlled. As shown in FIG. 2, a second, electric, motor 76 operable at a constant speed is located on the base 12. The motor 76 is a timer motion, or resolver drive, and drives a resolver 78. The resolver 78 determines the position of the shaft 81 of the drive 76, and responsively generates an analog signal which varies in accordance with shaft angular rotation.
As shown in FIGS. 5-7, the resolver drive 76 and resolver 78 are part of a programmable time 80. The timer 80 generates digital timing signals along output lines 82. The analog signal of the resolver 78 is converted to a digital signal by an analog-to-digital converter 84. A microprocessor 86 monitors the digital signal output of the converter 84. The microprocessor 86 is programmable for driving each of lines 82 to a logic ON state for generating timing signals T 1 -T 10 . The signals T 1 -T 10 have an ON time initiated by a digital output of the converter 84.
The timing signals are used to initiate operations of the press mechanisms, a charge gathering device and takeout mechanism upon receipt of each successive single glass gob or charge. The charge is received when the shaft 81 is at about 0°, by manual coordination. Thus, the timer 80 generates a number of outputs at different times in the 360° rotation of the shaft 81. FIG. 6 shows, for example, ten timing signals.
The programmable timer 80 is a separately obtainable item from the assignee of this application, Lynch Machinery. The timer is sold under the name P.E.T., Programmable Electronic Timer.
As shown in FIGS. 5 and 7, the signals on lines 82 are fed to a programmable, microprocessor based controller 88, via input modules such as module 90. The controller 88 directs a table controller 92, a press head controller 94, the pneumatic cylinders which are the controllers 96, 98, 101 of the separator, locator and brake mechanisms, and a spinner controller 100.
More specifically, as in FIG. 7, the controller 88 generates output signals upon output control lines 102 to actuate the mechanisms discussed. As an example, signals along the control lines 102 drive a table speed control module 104 to generate voltages to power the motor 26. The speed control module 104 receives four inputs from the controller 88. The module responds to each input by generating a voltage output of a particular set magnitude. Each particular voltage is set by a control knob among knobs 106 on the module 104. Similar modules are used and driven for the spinner and press head. The remaining output control lines actuate air valves to drive the pneumatic cylinders of the locator, separator and brake.
Additional input to the controller 88, or CPU, may be made via an input module 108. Electrical signals fed to the module 108 may be used as safety devices to override the timing instructions T 1 through T 10 . For example, position switches may be disposed about the press 10 for generating electrical signals to module 108 indicative of the mechanisms reaching particular positions of movement. The controller 88 may be programmed, for example, not to react to time signal T 1 to move the table 30 if the controller 88 has not first received an indication from a position switch that the locator pin is down, in its proper position for table rotation.
The programmer controller 88 is also programmable for the number, type and spacing of molds placed on the mold table 30. As an example, the controller 88 is programmable for six spin molds at every other mold position on the table 30, to refrain from driving the press head 36, and to rotate the table uninterruptedly past mold positions without molds.
The controllers 88, 92, 94, 100 are further programmable and adjustable to mold parameters such as molding type and time. As an example, the spinning molds may be ramped up to a spin at low speed and held at that speed for a selected interval, then allowed to coast briefly, and finally ramped up and held at a high speed. The molds may be left to coast. Alternatively, the molds may be spun in another manner desired, and decelerated to rest.
The invention, and the manner and process of making and using it, are now described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains, to make and use the same. The best mode contemplated by the inventors of carrying out the invention is set forth. It is to be understood, of course, that the foregoing describes a preferred embodiment of the present invention and that modifications may be made therein without departing from the spirit or scope of the present invention as set forth in the appended claims. To particularly point out and distinctly claim the subject matter regarded as invention, the following claims conclude this specification.
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A variable index molding press having a mold table rotatably placed on a base including a plurality of mold positions on the table for locating various numbers of molds thereon with molding means on the base for cooperating successively with one or all of the molds on the said table at a molding station, table drive means for rotating the table, electronic index control means connected to the drive table means and the molding means including a digital computer programmed for number, type and spacing of the molds, molding times for controlling and synchronizing the molding and the table rotation and a time signal source adapted to generate time representative signals to the computer.
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BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the field of semiconductor thin film resistors, and more particularly, to a novel integrated circuit thin film resistor having a current density enhancing layer.
[0003] 2. Description of the Prior Art
[0004] In semiconductor integrated circuits (ICs), a resistor may be used to control the resistance of other electronic components of the IC. As is known to those skilled in the art, the resistance, R, of a resistor is proportional to the length, L, of the resistor and the reciprocal cross sectional area, 1 /A, of the resistor; the L and A are measured in the direction of current flow. The basic equation for resistance of a resistor is thus: R=L/A, where R, L and A are as defined above.
[0005] Prior art resistors are typically composed of polysilicon that has been doped. As the integration of semiconductor devices increases, each component within a semiconductor IC has to provide equivalent or better electrical properties. A downscaled resistor thus has to provide a constant resistance value that does not fluctuate much during use. However, due to the properties of polysilicon, a prior art resistor comprised of doped polysilicon can only provide a limited resistance within a limited space. Employing a polysilicon resistor to provide relatively high resistance then becomes a problem in designing and fabricating a highly integrated semiconductor device.
[0006] Recently, doped polysilicon resistors have been replaced with a single thin film resistor that is comprised of a material that has a higher resistivity than that of polysilicon. Examples of such higher resistivity materials include, but are not limited to: TiN and TaN. Tantalum nitride, TaN, containing 36% N 2 is a material currently being used in the back-end-of-the line (BEOL) of most semiconductor devices.
[0007] BEOL resistors of high current carrying capability are highly desired by integrated circuit designers. Current TaN resistors (e.g., K1 resistor) offer only 0.5 mA/μm current/width and ever lower current density for 9SF and 10SF generations.
[0008] FIG. 1 depicts a BEOL resistor structure 10 according to the prior art. As shown, the BEOL resistor structure is formed atop of a first metallization level M 1 comprising a metal such as aluminum or copper, that is electrically coupled by via structures V 1 , to FEOL device structures 15 , e.g., CMOS FET or BJT or like transistor devices formed utilizing conventional techniques that are well known to those skilled in the art. The first metallization level M 1 includes an interlevel dielectric material layer 12 in which the M 1 metal layer structures are formed. As shown in the structure 10 of FIG. 1 , formed atop the interlevel dielectric material layer 12 and M 1 metallization is a first thin-film cap dielectric layer 14 of a material such as SiN and a thin dielectric layer 16 deposited thereon comprising an oxide, such as SiO 2 , or any other like oxide. The thin-film TaN resistor structure 20 of between 300 Å to 700 Å is shown formed on top of the dielectric layer 16 , and a thin film capping layer, i.e., etch stop layer 25 of SiN or SiCN (nBLOK), for example, is formed over the resistor structure. Then, typical fabrication processes as known in the art are used to form a further interlevel dielectric material layer and a via structure V 1 that connects the first metallization to a second metallization level M 2 .
[0009] For copper interconnects, better passivation and capping of the top surface of the metal has been proven to increase the electro migration performance of the copper. CoWP and reverse liner barrier films have be demonstrated to increase the performance of the interconnects. It is suspected, however, that for the TaN resistor, capping materials such as SiN or SiCN are not providing sufficient protection (and capping) for higher current performance.
[0010] Moreover, the currently provided etch stop layer, e.g., nBLOK (SiCN) or SiN, does not adhere well to the TaN film, and thus not as effective to prevent shifting of resistance during stress/aging.
[0011] U.S. Published Patent Application No. US 2004/0152299 describes a method of forming a thin film resistor. In this disclosure, a conductive layer 120 of TiN or TiW formed after the via hole (as in a linear) and a layer that comprises a typical etch stop layer (e.g., SiN). This “stack” actually is comprised of “Resistor film/SiN/Via.
[0012] U.S. Published Patent Application No. US 2004/0203192 describes methods for forming Cu lines with organic monolayers bonded to the surface for increased electro migration resistance.
[0013] It would be highly desirable to provide a novel thin film resistor structure and method of fabricating the resistor by providing a barrier material over the thin-film resistor structure to thereby enhance the current-carrying capability of the resistor.
[0014] It would be highly desirable to provide a novel thin film resistor structure and method of fabricating the resistor by providing a barrier material layer over a TaN film resistor structure that exhibits increased resistance to stress/aging.
SUMMARY OF THE INVENTION
[0015] It is an object of the present invention to provide a novel thin film resistor structure and method of fabricating the resistor.
[0016] It is a further object to provide a novel thin film resistor structure and method of fabricating the resistor by providing a barrier material over the thin-film resistor structure to thereby enhance the current-carrying capability of the resistor.
[0017] It is another object of the present invention to provide a novel thin film resistor structure of TaN material having an added barrier material layer with better adhesion to TaN to enhance the current carrying capability of the resistor.
[0018] According to the invention, this added barrier material is called the Current Density Enhancement Layer (CDEL) and provides increased resistance to shifting during stress/aging. The CDEL is thin; for example, less than 100 Å in thickness, and does not interfere with via etching process steps during BEOL or FEOL resistor fabrication.
[0019] The CDEL barrier film, in addition to SiN or SiCN cap materials over the TaN film, increases the current carrying capability of the resistor. In one aspect of the invention, the barrier films are formed by depositing a thin layer of Alumina, Al 2 O 3 , or deposition of a thin layer of Aluminum and air oxidizing or by oxidation using a low power plasma for a short duration. Other films with good adhesion to the resistor film may also be used.
[0020] Thus, in accordance with the present invention, there is provided a thin film resistor device and method of manufacture where the device includes a layer of a thin film conductor material and a current density enhancing layer (CDEL). The CDEL is an insulator material adapted to adhere to the thin film conductor material and enables the said thin film resistor to carry higher current densities with reduced shift in resistance with an applied stress, e.g., temperature. In one embodiment, the thin film resistor device includes a single CDEL layer formed on one side (atop or underneath) the thin film conductor material. In a second embodiment, two CDEL layers are formed on both sides (atop and underneath) of the thin film conductor material.
[0021] Advantageously, the structure and method of the invention is applicable to manufacturing in both BEOL and FEOL processes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a pictorial representation (through a cross sectional view) illustrating a basic BEOL thin-film TaN resistor structure and the processing employed in its manufacture according to the prior art;
[0023] FIGS. 2 ( a )- 2 ( f ) are pictorial representations (through cross sectional views) illustrating the process for forming a thin-film resistor having CDEL structure according to a first embodiment of the present invention; and,
[0024] FIGS. 3 ( a )- 3 ( d ) are pictorial representations (through cross sectional views) illustrating the process for forming a thin-film resistor having CDEL structure according to a second embodiment of the present invention.
DETAILED DESCRIPTION
[0025] The present invention, which provides processes for fabricating a precision thin-film resistor that exhibits enhanced current carrying capability, will now be described in greater detail by referring to the various drawings that accompany the present application. The drawings are provided herein for illustrative purposes and thus they are not drawn to scale.
[0026] Moreover, the drawings of the present invention show a fragment of a semiconductor wafer or chip in which only one resistor device region is shown in a Back-End-Of-Line (BEOL) manufacturing process. Although the drawings show the presence of only a single resistor device region, the present processes can be used in forming a plurality of resistors across different resistor device regions on the surface of a single semiconductor chip or wafer. Moreover, the invention is applicable to front-end-of-line (FEOL) processes whereby the inventive resistor device structure is formed on a Si-containing substrate, for instance having other device regions including bipolar transistors and/or CMOS devices, such as FETs, that are formed to the periphery of the resistor device region shown in the drawings of the present application.
[0027] Referring to FIG. 2 ( a ), a first step involves depositing the interlevel dielectric layer 12 , which may comprise a dielectric material such as a low-k organic or inorganic interlevel dielectric (ILD) of low-k dielectric material which may be deposited by any of number of well known techniques such as sputtering, spin-on, or PECVD and may include a conventional spun-on organic dielectrics, spun-on inorganic dielectrics or combinations thereof which have a dielectric constant of about 3.5 or less. Suitable organic dielectrics that can be employed include dielectrics that comprise C, O and H. Examples of some types of organic dielectrics that can be employed in the present invention include, but are not limited to: aromatic thermosetting polymeric resins, and other like organic dielectrics. The organic dielectric employed as interlevel dielectric layers may or may not be porous, with porous organic dielectric layers being highly preferred due to the reduced k value. Suitable inorganic dielectrics that may be employed as the interlevel dielectric typically comprise Si, O and H, and optionally C, e.g., SiO 2 , SiCOH, carbon-doped oxides (CDO), silicon-oxicarbides, organosilicate glasses (OSG) deposited by plasma enhanced chemical vapor deposition (CVD) techniques. Illustrative examples of some types of inorganic dielectrics that can be employed include, but are not limited to: the silsesquioxane HOSP, methylsilsesquioxane (MSQ), hydrido silsesquioxane (HSQ), MSQ-HSQ copolymers, tetraethylorthosilicate (TEOS), organosilanes and any other Si-containing material. For purposes of discussion it is assumed that the interlevel dielectric material layer 12 is SiO 2 .
[0028] Utilizing conventional photolithographic processing techniques, the first metal layer M 1 is formed at designed locations that connect with FEOL devices utilizing processes well known in the art. For purposes of description, the M 1 metal layer may comprise copper or aluminum.
[0029] Formed above the interlevel dielectric material layer and M 1 metallization is a protective dielectric layer 14 typically comprised of an inorganic dielectric that differs from a second dielectric layer 16 deposited on top of layer 14 . In particular, the protective dielectric layer 14 is comprised of an oxide, nitride, oxynitride or any combination thereof, including multilayers. The protective dielectric layer 14 is typically a nitride such as SiN and the second dielectric layer 16 formed thereon is typically SiO 2 but could be other dielectrics such as SiCOH. The thickness of the protective dielectric layer 14 may vary depending on the type of material and deposition process employed in forming the same. Typically, the protective dielectric material has a thickness from about 10 Å to about 1000 Å.
[0030] After sequentially depositing layers 14 and 16 , a layer 20 of material forming the thin-film resistor is deposited atop the second dielectric layer 16 . This layer 20 is typically TaN, however may include other conductive metal materials including, but not limited to: Ta, TaN, Ti, TiN, W, WN, NiCr, SiCr, and the like, for forming the thin film resistor. Combinations of these materials are also contemplated herein. Preferably, the conductive metal 20 comprises TaN, TiN, NiCr or SiCr, with TaN and TiN being particularly preferred. The conductive metal 20 is a thin layer whose thickness is typically from about 300 Å to about 700 Å with a thickness from about 450 Å to about 550 Å being more typical. The conductive metal 20 forming the thin-film resistor can be formed on the etch stop layer 14 utilizing any deposition process including, for example, CVD, PECVD, sputtering, plating, evaporation, ALD and other like deposition processes.
[0031] After forming the conductive metal 20 , a thin Current Density Enhancing Layer (CDEL) 50 is patterned and formed on the conductive metal 20 providing the structure shown, for example, in FIG. 2 ( a ). The CDEL layer 50 comprises a dielectric material such as Al 2 O 3 layer deposited to a thickness of less than 100 Å by atomic layer deposition (ALD), for example, utilizing a precursor such as Trimethylaluminum Al(CH 3 ) 3 and an oxidant such as Ozone (O 3 ) at a deposition temperature of 380° C., in one embodiment Preferably, the thickness of the CDEL layer is less than 50 Å. The CDEL layer 50 is preferably of a material that adheres well to the underlying thin film resistor material TaN and increases the current carrying capability of the resistor device as will be described in greater detail herein below. More importantly, as will be described in greater detail herein, the provision of a CDEL layer 50 reduces the shift in resistance when a temperature stress is applied, for example. Thus, besides deposition of the Al 2 O 3 CDEL layer 50 , alternatively, the CDEL layer 50 may comprise a thin layer of Aluminum, deposited to a thickness ranging between 10 Å and 20 Å and oxidizing the thin Al layer by an O 2 plasma or air oxidation. In other example embodiments, the CDEL layer 50 may comprise metal oxides such as Ta 2 O 5 , HfO 2 , ZrO 2 , and the like, with the thickness ranging from 10 Å to 50 Å.
[0032] After providing the structure 100 shown in FIG. 2 ( a ), an etch stop layer 25 is deposited over the CDEL layer 50 structure. The etch stop layer 25 is formed utilizing any conformal deposition process including, for example, chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), chemical solution deposition, evaporation, atomic layer deposition (ALD) and other like deposition processes. The thickness of the etch stop layer 25 formed may vary depending on the deposition process used as well as the type of insulating material employed. Typically, and for illustrative purposes, the etch stop layer 25 has a thickness from about 20 to about 50 nm, with a thickness from about 30 to about 40 nm being more typical. Etch stop layer 30 may comprise any insulating material that can serve as a layer in which an etching process can be stopped on. Illustratively, the etch stop layer 25 may comprise an oxide, nitride, oxynitride or any combination thereof. In a preferred embodiment, the etch stop layer 25 is comprised of SiN, SiCN (nBLOK) or Si oxynitride.
[0033] In a next processing step, as shown in FIG. 2 ( b ), the thin-film resistor features are patterned by applying a lithographic mask (photoresist layer) 120 , for example. Then, as shown in FIG. 2 ( c ), an etching step is performed to form the resistor device 20 ′. This is accomplished by removing the layers 25 , 50 and 20 outside of the mask perimeter and stopping on layer 16 . Continuing, the formed resist layer 120 is removed in a next process step. Continuing as shown in FIG. 2 ( d ), a further interlevel dielectric layer, formed of materials described herein, is deposited on top of the exposed layer 16 and over the resistor structure 20 ′ and is planarized to form the structure shown in FIG. 2 ( e ). Finally, as shown in FIG. 2 ( f ), via structures V 1 may be formed using conventional techniques to electrically couple the resistor device 20 ′ of the invention to a further metallization layer, e.g., M 2 .
[0034] In a second embodiment of the invention, as shown in FIG. 3 ( a ), the thin film resistor structure is sandwiched between two thin CDEL layers 50 a, 50 b. This entails process steps of sequentially depositing dielectric layers 14 , 16 , first CDEL layer 50 a, the thin-film conductor layer 20 of material forming the thin-film resistor, a second CDEL layer 50 b deposited atop the thin-film conductor layer 20 and, the final etch stop layer 25 deposited above the second CDEL layer 50 b. As in the first embodiment, the two thin CDEL layers 50 a, 50 b comprise an insulator material such as Al 2 O 3 layer deposited to a thickness of less than 100 Å by atomic layer deposition (ALD) and preferably, to a thickness of about 50 Å or less. Alternatively, the CDEL layers 50 a,b may comprise a thin layer of Aluminum, deposited to a thickness ranging between 10 Å and 20 Å and oxidized by an O 2 plasma or air oxidation. In other example embodiments, the CDEL layers 50 a,b may comprise metal oxides such as Ta 2 O 5 , HfO 2 , ZrO2 and the like. Sandwiched between the first and second CDEL layers 50 a,b is the thin film resistor, typically TaN or other conductive materials, as described herein with respect to the first embodiment. As described above, the conductive metal 20 is a thin layer whose thickness is typically from about 300 Å to about 700 Å with a thickness of about 500 Å nominally. The CDEL layers 50 a,b preferably is formed of a material that adheres well to the underlying thin film resistor material TaN and increases the current carrying capability of the resistor device as will be further described. The conductive metal 20 forming the thin-film resistor can be formed on the first CDEL layer 50 a utilizing any deposition process including, for example, CVD, PECVD, sputtering, plating, evaporation, ALD and other like deposition processes. After forming the conductive metal 20 , the second thin Current Density Enhancing Layer (CDEL) 50 b is deposited on the conductive metal layer 20 , and the etch stop layer 25 is deposited on CDEL layer 50 b providing the structure shown in FIG. 3 ( a ). Then, in a next processing step, the thin-film resistor features are patterned using an applied lithographic mask (i.e., a resist layer not shown), and an etching step is performed to form the resistor device 20 ″ such as shown in FIG. 3 ( b ). This is accomplished by removing the layers 25 , 50 b, 20 and 50 a outside of the defined mask perimeter and stopping on layer 16 as shown in FIG. 3 ( b ). Next, the formed photomask (resist) layer 120 is removed. Continuing as shown in FIG. 3 ( c ), a further interlevel dielectric layer 125 , formed of materials described herein, is deposited on top of the exposed layer 16 and over the resistor structure 20 ″ and is planarized to form the structure shown in FIG. 3 ( c ). Finally, as shown in FIG. 3 ( d ), via structures V 1 may be formed using conventional techniques to electrically couple the resistor device 20 ″ of the invention to a further metallization layer, e.g., M 2 .
[0035] By providing the CDEL layer(s) according to the first and second embodiments, there is increased ability to pump in more current through the resistor structure 20 ′ ( FIG. 2 ( f )) and 20 ″ ( FIG. 3 ( d )) without degradation of the resistance, i.e., without shifting the resistance. This is illustrated in Table 1 as now described:
TABLE 1 CDEL R 0 R 24 % R 24 Information Vstress(V) I 0 (mA) I 24 (mA) (ohms) (ohms) shift 50A Al 2 O 3 1.38 20.62 19.56 66.93 70.55 5.41 100A 1.39 20.83 19.72 66.73 70.49 5.63 Al 2 O 3 No Al 2 O 3 1.19 20.36 18.84 58.45 63.16 8.10
[0036] Table 1 describes the resistance to shift for an example application of stress applied to an example resistor structure formed according to the present invention. The example resistor device structure is of a resistor size approximately 10 μm×10 μm with an applied current density of 2 mA/μm of width. The stress is a high temperature stress of approximately 125° C. applied for a period of 24 hours. Thus, as shown in Table 1, I 0 is Current at Time 0 Hours—before current stress; R 0 is resistance at Time 0 Hours—before current stress; I 24 is the current after Time 24 Hours, i.e., the end of current stress; R 24 is the device's resistance after time 24 Hours (end of current stress); and, % R 24 is shift in resistance after 24 hours of constant current stress at the above conditions. In an example resistor formed according to a first embodiment of the invention where the resistor comprises a single CDEL layer of Al 2 O 3 layer of approximately 50 Å, with a voltage impressed upon the resistor for a period of 24 hours at high temperature, Table 1 reveals that a 5.4% shift in resistance is exhibited as the initial resistance value, Ro, at time zero is 66.93 ohms. This corresponds to an initial current I 0 , of about 20.6 mA with 1.38 V impressed. At 24 hours later, the current has decreased to about 19.56 mA corresponding to an increased resistance R 24 to about 70.55 ohms which corresponds to a per cent resistance shift of about 5.4%. It is seen that for the case of a single sided CDEL of Al 2 O 3 layer of approximately 100 Å, with a voltage impressed upon the resistor for a period of 24 hours at high temperature, Table 1 reveals that a 5.6% shift in resistance is exhibited. This corresponds to an initial resistance value, R 0 , of 66.73 ohms at time zero and a final resistance value R 24 to 24 hours later of about 70.49 ohms with a constant voltage impressed upon the resistor device. As shown, this is a marked decrease in percent resistance shift exhibited in the case of a resistor device with no Al 2 O 3 CDEL layer which is about 8.0. As the example one-sided 100 Å CDEL layer resistor structure does not exhibit a marked increased resistance to shift as compared to an example one-sided 50 Å CDEL layer resistor structure, it is preferred that the resistor structure be formed with a CDEL layer of 50 Å or less.
[0037] It should be understood that, the resistor device of the present invention may be formed in front end of line processes, for example, formed on a substrate and coupled to other device regions including bipolar transistors and/or CMOS devices, such as FETs.
[0038] While the present invention has been described and shown with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details may be made without departing from the spirit and scope of the present application. It is therefore intended that the present application not be limited to the exact forms described and illustrated, but fall within the scope of the appended claims.
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A thin film resistor device and method of manufacture includes a layer of a thin film conductor material and a current density enhancing layer (CDEL). The CDEL is an insulator material adapted to adhere to the thin film conductor material and enables the said thin film resistor to carry higher current densities with reduced shift in resistance. In one embodiment, the thin film resistor device includes a single CDEL layer formed on one side (atop or underneath) the thin film conductor material. In a second embodiment, two CDEL layers are formed on both sides (atop and underneath) of the thin film conductor material. The resistor device may be manufactured as part of both BEOL and FEOL processes.
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FIELD OF THE INVENTION
[0001] The present invention generally relates to heat sinks for use in electronics, and more particularly to phase change based heat sinks.
BACKGROUND OF THE INVENTION
[0002] Single phase heat exchangers, such as “parallel flow” heat exchangers having multiple fluid conduits are described in U.S. Pat. No. 5,771,964. In such parallel flow heat exchangers, each tube is divided into a plurality of parallel flow paths of relatively small hydraulic diameter (e.g., 0.070 inch or less), which are often referred to as “microchannels”, to accommodate the flow of heat transfer fluid. Parallel flow heat exchangers may be of the “tube and fin” type in which flat tubes are laced through a plurality of heat transfer enhancing fins or of the “folded fin” type in which folded fins are coupled between the flat tubes. These types of heat exchangers have been used as cooling condensers in applications where space is at a premium. U.S. Pat. Nos. 6,347,662; 6,325,141; 5,865,243; and 5,689,881 further describe such heat exchangers having multiple conduits that serve as condensers.
[0003] The prior art associated with the cooling of computer chips and electronic components has utilized heat sinks of several basic types. Metal extrusions such as aluminum heat sinks have been used since the early days of computers when power densities were relatively low. These well known heat sinks have the disadvantage of low thermal performance (slow heat transfer), particularly when applied to systems operating at the high power density conditions of today's electronic devices and systems.
[0004] A second type of thermal management structure includes metal extrusions in combination with bases made formed from high thermal conductivity materials, such as copper or engineered materials or, even flat heat pipes. While addressing the heat spreading problem of metal extrusions, this type of heat sink still relies, in part, upon heat conduction through extended fins to external surfaces. Current extrusion techniques do not easily produce fins at the pitch and height required for high performance applications.
[0005] A third type of thermal management structure is a tower heat sink. Tower heat sinks often have a high conductivity core that is made of solid metal or heat pipes. Plate fins or machined structures surround the core to provide extended heat transfer surfaces. Heat is transferred upward through the core, then across the extended surfaces to be dissipated to the ambient environment. Assembly of plate fins to the core often requires manual labor which is expensive and sometimes yields inconsistent quality.
[0006] As a consequence, there continues to be a need for an improved heat sink for cooling electronic devices that satisfactorily meet today's high power density requirements while providing manufacturing flexibility.
SUMMARY OF THE INVENTION
[0007] The present invention provides a modular heat sink that has a modular construction comprising a heat sink module and one or more condenser modules. In one preferred embodiment, a modular heat sink is provided including an evaporator chamber defined between a base and a first plate. The base has a wick disposed on an interior facing surface so as to be located within the evaporator chamber. The wick is spaced away from an interior facing surface of the first plate, and is at times saturated with a two-phase vaporizable fluid. The first plate defines a pair of spaced apart openings that communicate with the evaporator chamber. A pair of conduits, one positioned within each of the first plate openings, each have a passageway arranged in fluid flow communication with the evaporator chamber. A condenser chamber is defined between a second plate and a third plate. The second plate defines a pair of spaced apart second openings that communicate with a respective one of the conduits so as to allow for cyclic fluid flow communication between the evaporator chamber and the condenser chamber. The third plate is disposed in spaced apart confronting relation to the second plate. Advantageously, the first plate and the second plate are spaced apart from one another so as to form a void between them and between the pair of conduits so that a folded fin may be positioned within the void to improve heat transfer. A plurality of modules may be stacked together, as needed, to provide improved heat transfer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] These and other features and advantages of the present invention will be more fully disclosed in, or rendered obvious by, the following detailed description of the preferred embodiments of the invention, which are to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein:
[0009] FIG. 1 is a perspective view of a modular heat sink formed in accordance with one embodiment of the invention;
[0010] FIG. 2 is an exploded perspective view of the modular heat sink shown in FIG. 1 ;
[0011] FIG. 3 is a cross-sectional view of a modular heat sink, as taken along lines 3 - 3 in FIG. 1 ;
[0012] FIG. 4 is a perspective view of an eight module stacked heat sink formed according to one embodiment of the present invention;
[0013] FIG. 5 is an exploded perspective view of a first module of the stacked modular heat sink shown in FIG. 4 ;
[0014] FIG. 6 is a cross-sectional view, similar to that of FIG. 3 , of a first module in the stacked modular heat sink shown in FIG. 4 ;
[0015] FIG. 7 is a cross-sectional view of a portion of three stack modular heat sink arranged in accordance with an embodiment of the invention; and
[0016] FIG. 8 is a cross-sectional view of another embodiment of a module having a center separator plate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] This description of preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. The drawing figures are not necessarily to scale and certain features of the invention may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness. In the description, relative terms such as “horizontal,” “vertical,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship. In the claims, means-plus-function clauses are intended to cover the structures described, suggested, or rendered obvious by the written description or drawings for performing the recited function, including not only structural equivalents but also equivalent structures.
[0018] Referring to FIGS. 1-3 , a modular heat sink 1 formed according to one embodiment of the invention provides a single module 5 that includes a base plate 10 , a first spacer 20 , a first separator plate 25 , two conduits 30 , a folded fin core 33 , a second separator plate 35 , a second spacer 40 , and a top plate 45 . Base plate 10 includes an inner surface 47 , and is often formed as a rectangular sheet of thermally conductive material, such as copper, molybdenum, aluminum, or the like metal alloys, or thermally conductive composite structures. Inner surface 47 is often coated with a wick 55 , such as a sintered or brazed porous metal, screen, or felt layer of the type known in the art. When a module 5 is fully assembled, a working fluid saturates wick 55 . The working fluid may be selected from any of the well know two phase vaporizable liquids, e.g., water, alcohol, freon, methanol, acetone, fluorocarbons or other hydrocarbons, etc.
[0019] First spacer 20 comprises a thermally conductive frame formed from a pair of spaced-apart lateral rails 60 and a pair of spaced-apart longitudinal rails 65 that together define a central opening 67 . First spacer 20 often has a rectangular shape that complements base 10 . Lateral rails 60 and longitudinal rails 65 have a similar width and thickness. First separator plate 25 comprises a sheet of thermally conductive material having a central surface 69 located between spaced-apart lateral openings 70 that are defined adjacent to the lateral side edges of the sheet. Each opening 70 is defined by a lateral rail 75 and spaced-apart longitudinal rails 80 that together define an elongate opening. The size and shape of first separator plate 25 is substantially the same as the size and shape of first spacer 20 .
[0020] Conduits 30 each comprise an open ended tube, often having an ellipsoidal or rectangular cross-sectional shape, with an outer surface 35 . Each conduit 30 is formed from a thermally conductive material, such as copper, molybdenum, aluminum, or the like metal alloys, or thermally conductive composite structures, and has a shape and size that is substantially the same as the shape and size of lateral openings 70 of first separator plate 25 .
[0021] Folded fin core 33 may be formed from a continuous sheet of thermally conductive material, that has been folded into alternating flat ridges 100 and troughs 105 . In aggregate, flat ridges 100 combine to define two substantially planar outwardly directed faces 108 at the top and bottom of folded fin core 33 . Flat ridges 100 and troughs 105 define spaced fin walls 110 , with the end most walls comprising two external side walls 115 . Folded fin core 33 also defines two end edges 120 that follow the contour defined by flat ridges 100 and troughs 105 .
[0022] Second separator plate 35 has a structure similar to that of first separator plate 25 . In particular, second separator plate 35 comprises a sheet of thermally conductive material having a central surface 125 located between spaced apart lateral openings 140 defined adjacent to the lateral side edges of the sheet. Each opening 140 is defined by a lateral rail 145 and spaced-apart longitudinal rails 148 . The size and shape of second separator plate 35 is substantially the same as the size and shape of first separator plate 25 . Second spacer 40 has a structure similar to that of first spacer plate 20 . Second spacer 40 comprises a thermally conductive frame formed from a pair of spaced-apart lateral rails 160 and a pair of spaced-apart longitudinal rails 165 that together define a central opening 167 . Second spacer 20 often has a rectangular shape that is substantially similar to base 10 . Lateral rails 160 and longitudinal rails 165 have a similar width and thickness to one another. When only a single module is to be formed, a top plate 45 is provided that is similar to base 10 in that it is often formed as a rectangular sheet of thermally conductive material, such as copper, molybdenum, aluminum, or like metal alloys or thermally conductive composite structures.
[0023] A single module 5 that may form a portion of a modular heat sink 1 is assembled in the following manner. Base 10 is first positioned on a flat surface such that wick 55 is exposed on upwardly facing inner surface 47 . Spacer 20 is then circumferentially positioned on a peripheral edge surface of base 10 so as to encircle a preponderance of wick 55 . First separator plate 25 is then positioned atop first spacer 20 such that lateral rails 75 and longitudinal rails 80 lie atop corresponding portions of first spacer 20 with central surface 69 facing upwardly. Conduits 30 are positioned within openings 70 of first separator plate 25 so as to project upwardly. Conduits 30 , first separator plate 25 and first spacer 20 together define a void space 180 ( FIG. 3 ) separating the lower edge of conduit 30 from the top surface of wick 55 on base 10 . With conduits 30 positioned within first separator 25 , folded fin core 33 is positioned between conduits 30 so that a bottom face 108 of folded fin core 33 is arranged with the outer surfaces of flat ridges 100 in engaged thermal communication with central surface 69 of first separator 25 . In this arrangement, external side walls 115 thermally engage the interior portion of outer surface 35 of each conduit 30 . Thus, folded fin core 33 is arranged within module 5 so as to be in thermal conduction communication with first separator plate 25 and conduits 30 .
[0024] Once folded fin core 33 is secured between conduits 30 and first separator plate 25 , second separator plate 35 is positioned on the top face 108 of folded fin core 33 . In this position, the top edges of each conduit 30 are positioned within lateral openings 140 of second separator plate 35 and secured in position. Second spacer 40 is then positioned atop second separator plate 35 so that lateral rails 160 and longitudinal rails 165 rest atop lateral rails 145 and longitudinal rails 148 of second separator plate 35 , respectively, and with central surface 125 facing upwardly. Top plate 45 is then positioned over second spacer 40 and fastened along a circumferential peripheral edge surface to rails 160 , 165 of spacer 40 . During the foregoing assembly, each of the individual parts may be fastened to one another by any one of a number of known fixation methods, including welding, brazing, soldering, or through the use of thermal epoxies.
[0025] Referring to FIG. 3 , upon full assembly of module 5 a closed loop fluid flow path 182 is formed in which an evaporation chamber 183 is defined between base 10 and first separator plate 25 and a condensation chamber 185 is formed between top plate 45 and second separator 35 . Evaporation chamber 183 and condensation chamber 185 are arranged in fluid communication with one another via conduits 30 . Wick 55 is disposed within evaporation chamber 183 , and is saturated with a two-phase working fluid.
[0026] In operation, a heat source (not shown) thermally engages an external surface of base 10 . The heat generated by the heat source is transferred through base 10 by conduction and thereby vaporizes the working fluid saturating wick 55 within evaporation chamber 183 . The working fluid vapor flows through conduits 30 and into condensation chamber 185 . At the same time, air flows through folded fin core 33 provides convective heat transfer through spaced fin walls 110 , which in-turn cools the corresponding separator plates 25 , 35 and conduits 30 . The working fluid condenses substantially within condensation chamber 185 and flows back to evaporation chamber 183 so as to resaturate wick 55 on base 10 , thus completing a two-phase heat transfer cycle.
[0027] Depending upon the power requirements of the heat source, multiple cooling modules 5 a - h may be stacked for optimum efficiency of modular heat sink 1 ( FIG. 4 ). In a multiple module embodiment of the present invention, a third separator plate 190 is positioned atop second spacer 40 ( FIG. 5 ). Third separator plate 190 has a structure similar to that of first and second separator plates 25 , 35 . In particular, third separator plate 190 comprises a sheet of thermally conductive material having a central surface 191 located between spaced apart lateral openings 192 defined adjacent to the lateral side edges of the sheet. Each opening 192 is defined by a lateral rail 195 and spaced-apart longitudinal rails 198 . The size and shape of third separator plate 190 is substantially the same as the size and shape of first and second separator plates 25 , 35 ( FIG. 5 ). A third spacer has a structure similar to that of first and second spacers 20 , 40 .
[0028] A second pair of conduits 30 are positioned within openings 192 of third separator plate 190 so as to project upwardly. Second separator plate 35 and third separator plate 190 together define a void condenser space separating lower module 5 a from upper module 5 b . With the second pair of conduits 30 positioned within third separator plate 190 , a second folded fin core 213 is positioned between second pair of conduits 30 so that its bottom face 108 is arranged with the outer surfaces of flat ridges 100 in thermal communication with central surface 191 of third separator 190 . Once again, external side walls 115 thermally engage the interior portion of outer surface 35 of each conduit 30 . Thus, the second folded fin core 213 is arranged within second module 5 b so as to be in thermal conduction communication with third separator plate 190 and second pair of conduits 30 . The foregoing assembly may be repeated by adding additional separator plates, conduits, and folded fin cores until a complete stack is formed ( FIGS. 4, 5 , and 7 ).
[0029] Referring to FIGS. 4 and 7 , upon full assembly of a stacked module closed loop fluid flow path 182 opens through one or more intermediate flow chambers 220 with evaporation chamber 183 being arranged in fluid communication with a plurality of flow chambers 220 , via pairs of conduits 30 . If additional vapor flow is required, a through opening 225 may be formed in an intermediate separator plate 227 ( FIG. 8 ).
[0030] It is to be understood that the present invention is by no means limited only to the particular constructions herein disclosed and shown in the drawings, but also comprises any modifications or equivalents within the scope of the claims.
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A modular based heat sink which can be easily optimized for a given heat source relies upon both phase change based heat transfer and condenser modules that combine the efficiency of folded fin cooling and the efficiency of the two phase heat transfer.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to and is a continuation of U.S. patent application Ser. No. 13/199,197 filed on Aug. 22, 2011 entitled CASING STRIPPER ATTACHMENT which was filed on the same date that application Ser. No. 13/199,196 entitled “PIPE WIPER BOX” to Grant Pruitt and Cris Braun was filed and the same date that application Ser. No. 13/199,198 entitled “ADAPTER ASSEMBLY” to Grant Pruitt and Cris Braun was filed.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
REFERENCE TO A MICROFICHE APPENDIX
Not Applicable.
RESERVATION OF RIGHTS
A portion of the disclosure of this patent document contains material which is subject to intellectual property rights such as but not limited to copyright, trademark, and/or trade dress protection. The owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent files or records but otherwise reserves all rights whatsoever.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Oil, gas, water and geothermal wells are typically drilled with a drill bit connected to a hollow drill string which is inserted into a well casing cemented in the well bore. A drilling head is attached to the well casing, wellhead or to an associated blowout preventer to seal the interior of the well bore from the surface. The drilling head also facilitates forced circulation of drilling fluid through the well while drilling or diverting drilling fluids away from the well. Drilling fluids include, but are not limited to, water, steam, drilling muds, air, and other gases.
Such drilling fluids should remain within the well. Spillage of the drilling fluids inconvenience workers and costs money and time. Furthermore, the stripper rubber connection should be made quickly and achieve a fluid tight seal.
However, casing typically includes various diameter sections. Thus, the rubber was sized to maintain sealing contact with the casing or the smallest diameter component which traveled through the well. The rubber must be rigid enough to withstand the pressures of the drilling fluid yet resilient enough to maintain a seal on the casing and other tools as the casing and other tools pass through the well.
Present day drilling operations are extremely expensive, and an effort to increase the overall efficiency of the drilling operation while minimizing expense requires the essentially continuous operation of the drilling rig. Thus, it is imperative that downtime be minimized.
In this regard, there is a need for improved sealing of the casing and allowing different sized casing and other tools through the casing stripper.
Pressure control is achieved by means of one or more stripper rubbers. Stripper rubbers typically taper downward and include rubber or other elastomeric substrate so that the downhole pressure pushes up on the rubber, pressing the rubber against the casing inserted into the stripper rubber to achieve a fluid-tight seal.
Casing stripper rubbers are connected or adapted to the drilling nipple at the nipple base to establish and maintain the pressure control seal around a down hole tubular (i.e. casing, etc.). The casing striper rubber replaces the bearing assembly when running casing and is especially useful in containing cement or drilling fluid returning to the surface. Casing stripper rubber sizes usually vary from 4½ inches to 13⅜ inches oversized.
Known casing stripper rubbers attach via a threaded connection to the drilling nipple. The threaded connection requires a specialized casing stripper rubber with internal threads. These specialized strippers can only be attached to threaded connections. Such threaded connections create difficulties when attaching and removing the casing stripper rubber. Dirt and other debris found on the drilling nipple increase the difficulty of attaching the casing stripper rubber to the drilling nipple. After use of the casing stripper rubber, users must remove the casing stripper rubber from the drilling nipple. The threaded connection of the casing stripper rubber increases the difficulty of removing the casing stripper rubber from the drilling nipple. In most instances, users cannot remove the casing stripper rubber from the drilling nipple. Users must either cut the casing stripper rubber from the drilling nipple or otherwise destroy the casing stripper rubber to remove the casing stripper rubber.
Cutting and otherwise destroying the casing stripper rubber requires additional time and effort for removing the casing stripper rubber. The casing stripper rubber attachment of the present invention improves the speed and efficiency of attaching and removing the casing stripper rubber. The improved efficiency of attaching and removing the casing stripper rubber decreases the drilling costs by reducing downtime of the operation. Furthermore, the present invention reduces the costs of manufacturing the casing stripper rubber. Furthermore, the casing stripper rubber of the present invention provides a greener solution than the known art. The casing stripper rubber of the present invention reduces the harmful environmental effects of removing the known casing stripper rubbers.
Therefore, a casing stripper rubber assembly that overcomes abovementioned and other known and yet to be discovered drawbacks associated with known casing stripper rubber assemblies individually and, optionally, would be advantageous, desirable and useful.
II. Description of the Known Art
Patents and patent applications disclosing relevant information are disclosed below. These patents and patent applications are hereby expressly incorporated by reference in their entirety.
U.S. Pat. No. 7,717,168 (“the '168 patent”) issued to Williams et al. on May 18, 2010 teaches a reinforced stripper rubber assembly with a stripper rubber body including a drillstring engaging portion having a drillstring bore extending axially therethrough. The drillstring engaging portion of the stripper rubber body taught by the '168 patent is made from an elastomeric material, has an inner surface that engages a drillstring when the drillstring is disposed therein and has a reinforcing insert receiving recess within an exterior surface thereof extending at least partially around the drillstring bore. The '168 patent teaches that a reinforcing insert is disposed within the reinforcing insert receiving recess. The reinforcing insert taught by the '168 patent includes an elastomeric material bonded to the stripper rubber body within the reinforcing insert receiving recess. A support structure taught by the '168 patent is disposed within a support structure engaging portion of the stripper rubber body. The support structure taught by the '168 patent includes a central opening generally aligned with the drillstring bore thereby allowing the drillstring to pass jointly through the central opening and the drillstring bore.
U.S. Pat. No. 7,717,170 (“the '170 patent”) issued to Williams on May 18, 2010 teaches an upper stripper rubber canister system comprising a canister body and a canister body lid. The canister body taught by the '170 patent includes an upper end portion, a lower end portion and a central passage extending therebetween. The central passage taught by the '170 patent is configured for having a stripper rubber assembly disposed therein. The upper end portion of the body includes a plurality of bayonet connector structures. The canister body lid taught by the '170 patent includes an exterior surface, an upper end portion, a lower end portion and a central passage extending between the end portions thereof. The '170 patent teaches that the exterior surface is configured for fitting within the central passage of the canister body. The canister body lid taught by the '170 patent includes a plurality of bayonet connector structures integral with its exterior surface. Each canister body lid bayonet connector structure taught by the '170 patent is configured for being engaged with one of the canister body bayonet connector structures for interlocking the canister body lid with the canister body.
U.S. Pat. No. 5,062,479 (“the '479 patent”) issued to Bailey, et al. on Nov. 5, 1991 teaches a stripper rubber for use in a drilling head to seal against a work string deployable through the drilling head. The stripper rubber taught by the '479 patent is longitudinally restrained to prevent extrusion of the stripper under pressure and to reduce the tensile and compressive stresses on the stripper rubber. The '479 patent teaches one embodiment of the stripper rubber that incorporates upper and lower metal rings which are maintained in spaced apart relation by vertical rods thereby allowing radial expansion as tool joints pass through the rubber but prevents inversion of the stripper rubber under pressure. The '479 patent teaches a second embodiment that bonds a stripper rubber into a cylinder which restrains the rubber in the vertical direction. Radial deflection is accommodated by allowing the rubber to flow vertically as a tool joint passes therethrough. Each of the stripper rubbers taught by the '479 patent incorporates an integrally formed drive bushing which facilitates mounting within the drilling head.
U.S. Pat. No. 5,213,158 (“the '158 patent”) issued to Bailey, et al. on May 25, 1993 teaches a drilling head with dual rotating stripper rubbers designed for high pressure drilling operations ensuring sealing under the extreme conditions of high flow or high pressure wells such as horizontal drilling. The dual stripper rubbers taught by the '158 patent seal on the same diameter yet are manufactured of different materials for different sealing functions. The lower stripper rubber is manufactured from a more rigid, abrasive resistant material to divert the flow from the well. The upper stripper rubber is manufactured of a softer sealing material that will closely conform to the outer diameter of the drill string thereby preventing the flow of fluids through the drilling head.
U.S. Pat. No. 5,647,444 issued to Williams on Jul. 15, 1997 (“the '444 patent”) discloses a rotating blowout preventor having at least two rotating stripper rubber seals which provide a continuous seal about a drilling string having drilling string components of varying diameter. A stationary bowl taught by the '444 patent is designed to support a blowout preventor bearing assembly and receives a swivel ball that cooperates with the bowl to self-align the blowout preventor bearing assembly and the swivel ball with respect to the fixed bowl. The '444 patent teaches that chilled water is circulated through the seal boxes of the blowout preventor bearing assembly and liquid such as water is pumped into the bearing assembly annulus between the stripper rubbers to offset well pressure on the stripper rubbers.
SUMMARY OF THE INVENTION
The casing stripper rubber of the present invention attaches to an attachment body for installation within a housing such as the bowl. The attachment body includes a base and an attachment lip. The base provides an outer surface for securing the attachment body and stripper rubber to the housing. The clamp secures the base of the attachment body with the housing. The stripper rubber fastens to the attachment lip of the attachment body to be secured within the bowl.
The base of the present invention attaches to a pipe such as a drilling nipple. The height of the pipe extending upwards from the base may vary according to the needs at the well. The drilling nipple assists with inserting the casing into the well, a process known as running casing. The attachment of the casing stripper with the attachment body increases the bore through which the casing and other downhole tools can be inserted. Therefore, larger casing and other downhole tools can be used within the well.
The known art provides a casing stripper rubber that attaches via a threaded connection that is limited in bore size. Therefore, the known art does not allow larger drilling tools, downhole tools, casing, and pipe to pass through the stripper aperture. The known art also increases the difficulty in attaching and removing the casing stripper rubber. The present invention provides a non-threaded connection thus allowing for the casing stripper rubber to be used in different environments. The attachment of the casing stripper rubber to the attachment body taught by the present invention enables a larger bore size and stripper aperture. The larger stripper aperture of the present invention allows larger size drilling tools, downhole tools, and casing to pass through the stripper aperture of the present invention.
It is an object of the present invention to provide an improved casing stripper rubber.
It is another object of the present invention to increase the functionality of non-threaded stripper rubbers.
It is another object of the present invention to reduce the number of specialized threaded stripper rubbers required at a drilling site.
Another object of the present invention is to allow larger drilling tools, downhole tools, and casing to pass through the attachment body and casing stripper.
Another object of the present invention is to maintain drilling fluids within the well.
Another object of the present invention is to create a safer work environment for rig personnel.
Another object of the present invention is to simplify the method of attaching and removing the casing stripper rubber.
Another object of the present invention is to allow a casing stripper rubber system that will save valuable time on the rig, thus reducing time in which the rig is inoperable.
In addition to the features and advantages of the casing stripper attachment according to the present invention, further advantages thereof will be apparent from the following description in conjunction with the appended drawings.
These and other objects of the invention will become more fully apparent as the description proceeds in the following specification and the attached drawings. These and other objects and advantages of the present invention, along with features of novelty appurtenant thereto, will appear or become apparent in the course of the following descriptive sections.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following drawings, which form a part of the specification and which are to be construed in conjunction therewith, and in which like reference numerals have been employed throughout wherever possible to indicate like parts in the various views:
FIG. 1 is an environmental view showing one embodiment of the present invention;
FIG. 2 is another environmental view thereof;
FIG. 3 is a top view of one embodiment of the present invention;
FIG. 4 is a top perspective view thereof;
FIG. 5 is a bottom perspective view thereof;
FIG. 6 is a side view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is an exploded view thereof; and
FIG. 9 is an environmental view of one embodiment of the present invention.
DETAILED DESCRIPTION
Referring to FIG. 1 , the attachment body of the present invention is generally illustrated by reference numeral 100 . The attachment body 100 is characterized by an attachment lip 110 and base 106 . The stripper rubber 112 attaches to the attachment lip 110 of the attachment body 100 . After the stripper rubber 112 is attached to the attachment body 100 , the attachment body 100 with stripper rubber 112 is installed within a housing 104 such as a bowl 104 . The clamp 102 secures the attachment body 100 with the housing 104 .
Continuing to refer to FIG. 1 , the housing 104 , a bowl in one embodiment, is installed on the drilling rig floor. The clamp 102 attaches attachment body 100 and casing stripper 112 to the housing 104 for use at the well. The base 106 has a diameter that is large enough to be secured within clamp 102 . Continuing to refer to FIG. 1 , attachment body 100 and casing stripper 112 may be removed from housing 104 and installed into housing 104 . To install attachment body 100 , the clamp 102 must be opened for insertion of attachment body 100 . The user closes clamp 102 while the attachment body 100 is within clamp 102 to secure attachment body 100 and casing stripper 112 to the housing 104 as shown in FIG. 2 .
In FIG. 2 , attachment body 100 and casing stripper 112 are secured with housing 104 for use at the well. FIG. 2 shows the attachment body 100 and casing stripper 112 installed into housing 104 for operation. The user inserts casing and other downhole tools into lip aperture 120 and stripper aperture 114 for use of the casing and other downhole tools in the well. The base 106 is sized such that the base 106 will fit within the housing 104 . The base 106 and attachment body 100 are also sized such that the base 106 and attachment body 100 will be secured within the housing 104 and not pass completely through the housing 104 .
FIG. 3 shows a top view of the attachment body 100 with the casing stripper 112 installed on attachment body 100 . Attachment lip 110 secures to base 106 . In one embodiment, attachment lip 110 is welded to base 106 . Attachment lip 110 provides a bottom surface 111 for attaching the casing stripper 112 . The attachment lip 110 has an upper surface 109 and a lower surface 111 . The casing stripper 112 attaches to the lower surface 111 of attachment lip 110 . Fastener lock bodies 108 , such as a nut, lock nut, or other locking body, secure the fastener 116 . The lock bodies 108 contact the upper surface 109 of attachment lip 110 .
When installing casing and/or other downhole equipment, the user inserts the casing and/or other downhole equipment through lip aperture 120 and stripper aperture 114 . The bolted attachment of casing stripper 112 to attachment lip 110 provides a larger bore that allows casing and/or downhole equipment of a greater size than the known art.
The bolted attachment of casing stripper 112 improves upon previous connections of known casing strippers. The connections of known casing strippers require a threaded connection on the nipple. After use of the known casing strippers, the users cannot easily remove the known casing strippers from the nipple. Dirt and other debris interfere with the threaded connection thus increasing the difficulty in removing the casing stripper. Furthermore, the threads of the known casing strippers may be stripped through use of the known casing strippers. The users found it simpler to remove the known casing strippers by cutting or otherwise destroying the casing stripper to remove the casing stripper from the nipple.
FIG. 4 shows the lip aperture 120 in greater detail. Lip aperture 120 allows the casing and downhole equipment to pass through attachment body 100 . In one embodiment, the base 106 attaches to the attachment lip 110 at weld 128 . A person may weld attachment lip 110 to base 106 at weld 128 .
Attachment lip 110 also provides a surface for attaching a pipe, such as a drilling nipple to the base 106 . In one embodiment, a pipe, such as a drilling nipple, is welded to base 106 above the upper surface 109 of attachment lip 110 . In one embodiment, the pipe is welded adjacently above the upper surface 109 . The pipe extends upward above the casing stripper 112 and the attachment lip 110 . The pipe may vary in height depending upon the particular drilling needs and the environment in which the casing stripper 112 is installed.
FIGS. 5 and 7 show bottom perspective views of the attachment body 100 secured to the casing stripper 112 . Casing stripper 112 provides a fastening head 126 . The top side of fastening head 126 contacts attachment lip 110 . The bottom side of fastening head 126 contacts fasteners 116 for securing casing stripper 112 to attachment lip 110 . The fastening head 126 extends outward from the casing stripper 112 to increase the size of the surface area of the casing stripper 112 . The fastening head 126 increases the surface area of the casing stripper 112 for attaching the casing stripper 112 to the attachment lip 110 . The fastening head 126 provides installation apertures 124 with sufficient surface for fasteners 116 to secure the casing stripper 112 to the attachment lip 110 .
The casing stripper 112 also provides adjustment apertures 118 shown in FIGS. 5 and 6 for tightening and loosening fasteners 116 found on the bottom side of casing stripper 112 . The fasteners 116 are inserted through installation apertures 122 of fastening lip 110 and installation apertures 124 of casing stripper 112 . Nuts 108 or other locking bodies secure the fasteners 116 within the installation apertures to install casing stripper 112 to attachment lip 110 . The nuts 108 of one embodiment of the present invention are found above the upper surface 109 of the attachment lip 110 . In one embodiment, the nuts 108 are located adjacently above the upper surface 109 of the attachment lip 110 .
Referring to FIGS. 5-8 , the attachment of the casing stripper 112 to the base 106 will be discussed in greater detail. The casing stripper 112 provides a fastening head 126 that protrudes outward from the casing stripper 112 . Fastening head 126 is placed adjacent the lower surface 111 of attachment lip 110 . The fastening head 126 contacts lower surface 111 of attachment lip 110 when casing stripper 112 attaches to attachment lip 110 . The installation apertures 124 of the fastening head 126 enables passage of fasteners 116 for securing the casing stripper 112 to the attachment lip 110 .
In one embodiment of the present invention, the casing stripper 112 is a non-threaded rubber stripper that is attached to a rotating head. The present invention allows the non-threaded rubber stripper to be used in both the rotating head and the drilling nipple. Therefore, the present invention allows users to use a single type of rubber stripper thus eliminating the need for specialized threaded stripper rubbers. Users of the present invention may avoid purchasing and storing the threaded stripper rubbers. The present invention increases the use of the non-threaded stripper rubber to allow a user to function without the threaded stripper rubber. The user can then avoid purchasing and storing the threaded stripper rubber.
From the fastening head 126 , the casing stripper 112 tapers to the stripper tail 130 . The casing stripper 112 narrows from the fastening head 126 to the stripper tail 130 . The casing stripper 112 contacts the casing as the casing is inserted through the stripper aperture 114 at stripper tail 130 of casing stripper 112 .
FIG. 8 shows an exploded view of the present invention. Fasteners 116 pass through adjustment aperture 118 and installation apertures 124 of casing stripper 112 and installation apertures 124 of attachment lip 110 to secure casing stripper 112 to attachment lip 110 . Fasteners 118 enter from the bottom side of casing stripper 112 and attachment lip 110 . Lock bodies 108 , such as nuts 108 , secure the casing stripper 112 to the attachment lip 110 . In one embodiment, lock bodies 108 contact the upper surface 109 of attachment lip 110 to secure casing stripper 112 to attachment lip 110 . Attachment lip 110 secures to base 106 by welding or some other attachment method.
FIG. 9 shows an environmental view of the attachment body 100 secured with the casing stripper 112 and the pipe 132 . In one embodiment, pipe 132 is a drilling nipple. The pipe 132 secures to the base 106 above the upper surface 109 of attachment lip 110 . In one embodiment, pipe 132 is welded to the base 106 . The pipe 132 varies in height according to the conditions of the well. The pipe provides an inner pipe aperture extending downwards to allow passage of casing and other downhole tools through the pipe 132 , attachment body 100 , and casing stripper 112 . The inner surface of the pipe 132 defines the pipe aperture. In one embodiment, the inner surface of the pipe 132 is located horizontally outwards from the installation apertures 122 when the pipe 132 is attached to base 106 .
From the foregoing, it will be seen that the present invention is one well adapted to obtain all the ends and objects herein set forth, together with other advantages which are inherent to the structure.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
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The casing stripper attachment secures the casing stripper within a housing, such as the bowl. The casing stripper rubber attaches to an attachment body for installation within the housing. The attachment body includes a base and an attachment lip. The base provides an outer surface for securing the attachment body and stripper rubber to the housing. The clamp secures the outer surface of the base with the housing. The stripper rubber fastens to the attachment lip of the attachment body to be secured within the bowl. The base of the present invention could attach to a drilling nipple that assists with inserting the casing into the well, a process known as running casing.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method and an apparatus for cutting a glass sheet and a method for manufacturing a PDP (plasma display panel), and particularly relates to a method and an apparatus for cutting a glass sheet for obtaining a plurality of glass sheets for the PDP from a single large-size glass sheet, as well as to a method for manufacturing the PDP.
[0003] 2. Description of the Related Art
[0004] A glass substrate is used for forming a display screen of a plasma display. Glass substrates of a size corresponding to the PDP screen size can be obtained by dividing a large-size glass sheet into several pieces. A glass sheet cutting apparatus is used for dividing the glass sheet. The glass sheet cutting apparatus comprises a heating device and a cooling device and is constructed such that thermal stress is applied to a sheet glass along a programmed cutting line of the sheet glass to thereby induce a crack in the sheet glass, and the glass sheet is cut along the programmed cutting line along with the progress of the crack. This technique is disclosed in Japanese Patent Laid-Open Publication No. 2000-281375, for example.
[0005] A sheet glass cannot be cut only by a crack induced by thermal stress, since the progress of the crack will stop in the vicinity of the edges of the sheet glass. According to the prior art, the edge of the sheet glass where the progress of the crack has stopped is pressed and held by a suitable presser so that the external pressing force is applied to the sheet glass to cut the same finally.
[0006] However, when the sheet glass is cut by imparting the external pressing force to the sheet glass as is done in the prior art, the sheet will be cut in the warped or deflected state. As the result, the cut surface will be formed obliquely and it is difficult to form the cut surface vertically to the surfaces of the glass substrate. Also, the cut line thus formed will not be straight and it is difficult to form the cut line in a straight line.
[0007] A glass substrate constituting a display is required to have a cut surface vertical to the surfaces of the substrate and, also, the cut line is required to be a single straight line or a single flat plane. With the conventional cutting method, however, these requirements cannot be satisfied.
SUMMARY OF THE INVENTION
[0008] An object of the present invention therefore is to provide a method and an apparatus for cutting a glass sheet or PDP substrate having a cut surface vertical to the substrate surfaces, as well as a method for manufacturing a PDP.
[0009] Another object of the invention is to provide a method and an apparatus for cutting a glass sheet or PDP substrate having a cut line formed in a straight line, as well as a method for manufacturing a PDP.
[0010] Followings are the features of the present invention. In the following description, for a better understanding of the invention, the constituent elements are given respective reference numerals of the attached drawings showing an embodiment of the present invention.
[0011] A method for cutting a glass sheet of the present invention comprises the steps of forming a linear groove ( 5 ) in a glass sheet ( 3 ) along a programmed cutting line ( 4 ) that is set for the glass sheet, and applying local pressure to an end of the groove. According to the invention, not the entire groove ( 5 ) is uniformly subjected to equal pressure. Instead, only the end of the groove ( 5 ) is subjected to local pressure so that an initial crack is induced at the end by the pressure applied thereto. Starting from this initial crack, the cracking force is guided by the groove ( 5 ) and inductively propagated along the groove ( 5 ). Distribution of the stress inside the glass corresponding to the cracking force propagated in this manner is concentrated locally at the plane that includes the groove ( 5 ) and is orthogonal to the surface of the glass sheet 3 . The plane to which the stress is concentrated in this manner corresponds to the cut surface due to the physical properties of amorphous glass. The cut surface is substantially orthogonal to the surfaces of the glass sheet. Even if the glass sheet is deflected during a cutting process, it will not affect adversely to the optimization of the cross section of the glass substrate to be cut.
[0012] It is preferable that the step of applying local pressure as described above further comprises the step of making a crack along the groove ( 5 ) in terms of ensuring the initial induction of stress.
[0013] A method for cutting a glass sheet of the present invention comprises the steps of forming a linear groove ( 5 ) in a glass sheet ( 3 ) along a programmed cutting line that is set for the glass sheet 3 , and arranging an elastic plate 20 at an end of the groove ( 5 ) for dissipating pressure and arranging a pressure absorber ( 15 ) on the rear surface of the glass sheet ( 3 ) opposing the end of the cutting line. When pressure is applied to the glass sheet ( 3 ) for cutting the same, the absorber ( 15 ) helps the dissipation of the pressure to allow the pressure to be dissipated equally along the cutting line, and to promote the concentration of stress of cutting.
[0014] The cutting method of the invention further and effectively comprises an additional step of lifting one of two sections of the glass sheet divided by the groove ( 5 ) with respect to the other one to from a V-shape section together, by using the groove ( 5 ) as the fulcrum. Since the groove ( 5 ) constitutes the junction of the two sections, the stress is concentrated on the groove. This method of bending the glass sheet into a V-shape section by the rotational displacement is adopted following the age-old technique used by glass craftsmen. According to the invention, however, the cutting operation is enabled to be automated and mechanized by locally pressing the programmed cutting line during the bending.
[0015] The glass sheet cutting method of the present invention is particularly effective for manufacturing a constituent element of a plasma display panel. In this case, the glass sheet ( 3 ) is used as a front substrate ( 33 ) or a rear substrate ( 38 ) of a plasma display panel.
[0016] A method for manufacturing a PDP device comprises a first process of producing a plasma display panel 30 , a second process of incorporating the plasma display panel 30 into a module ( 69 ) together with a circuit for driving the plasma display panel ( 30 ), and a third process of electrically connecting an interface ( 72 ) to the module ( 69 ), the interface ( 72 ) for transmitting an image signal after converting the format thereof to the module ( 69 ). In the first process, the method for producing the plasma display panel as described above is performed. By modularizing the PDP device components in this manner, the assembly and repair of the device can be simplified.
[0017] An apparatus for cutting a PDP substrate according to the present invention comprises an elastic plate ( 20 ) arranged at an end of a programmed cutting line ( 4 ) of a glass sheet ( 3 ) for dissipating pressure, a pressure absorber ( 15 ) arranged on the rear surface of the glass sheet ( 3 ) opposing the end of the cutting line, and a pressurizing mechanism ( 12 ) for applying pressure to the elastic plate ( 20 ). The elastic plate ( 20 ) may be formed effectively as a face plate to be in surface contact with the surface of the glass sheet ( 3 ). In this case, the face plate may be formed of a silicon rubber plate. The pressurizing mechanism makes a crack along and over the programmed cutting line ( 4 ). A locally pressing sharp blade ( 12 ) is specifically used as a member of the pressurizing mechanism for locally pressing the plate from over the programmed cutting line ( 4 ).
[0018] It will be effective to add a driving mechanism ( 19 ) for lifting one of two sections of the glass sheet ( 3 ) to be separated from each other by the programmed cutting line ( 4 ), with respect to the other one so as to form a V-shape section. By lifting one of the sections into a V-shape while locally pressing the end of the programmed cutting line ( 4 ), it is ensured that the glass sheet ( 3 ) is cut reliably along the programmed cutting line ( 4 ). By providing the pressurizing mechanism with a pressurizing needle ( 12 ) for transferring pressure to the glass sheet ( 3 ), it is ensured that stress is concentrated on the region of the cutting line.
[0019] The tip end ( 13 ) of the pressurizing needle ( 12 ) is pointed to the programmed cutting line ( 4 ) and is formed sharp so that local stress is concentrated on the linear region of the programmed cutting line ( 4 ). It is particularly effective that the pressurizing needle ( 12 ) applies pressure to the linear region of the glass sheet ( 3 ) through the elastic plate ( 20 ) in terms of realizing both dissipation of pressure and local concentration of stress. The tip end ( 13 ) may be sharp taking the form of a point, a line, or a semispherical surface, or a semicylindrical surface.
[0020] The pressurizing mechanism for applying cutting induction force to a programmed cutting line ( 4 ) set for a glass sheet ( 3 ) is formed by an applying member ( 12 ) mounted on the side of a first surface P 1 of the glass sheet ( 3 ) for applying cutting induction force to the glass sheet ( 3 ) from the side of the first surface P 1 and a support ( 15 ) arranged on the side of a second surface P 2 of the glass sheet ( 3 ) in opposition to the applying member ( 12 ) for elastically supporting the glass sheet ( 3 ) from the side of the second surface P 2 . Cutting force is imparted to the glass sheet ( 3 ) by the local pressure applied by the applying member ( 12 ) while dissipating the pressure on the side of the second surface P 2 , so that the glass sheet ( 3 ) can be cut straight along the programmed cutting line while preventing the glass sheet ( 3 ) from being broken.
[0021] The support is formed of an elastic displacement member ( 15 ) directly joined to the second surface P 2 and a rigid body ( 14 ) supporting the elastic displacement member ( 15 ). The elastic support ( 15 ) is preferably formed from silicon rubber. The tip end ( 13 ) of the applying member ( 12 ) is effectively formed sharp to take a form of a point, a line, a semispherical surface, or a semicylindrical surface.
[0022] The pressurizing mechanism is formed by a first suction member ( 25 ) attached to the second surface P 2 side of one of the sections of the glass sheet ( 14 ) to be divided by the programmed cutting line ( 4 ) so as to adhere by suction to the second surface P 2 , a second suction member ( 23 ) attached to the second surface P 2 side of the other section of the glass sheet ( 3 ) to be divided by the programmed cutting line ( 4 ) so as to adhere by suction to the second surface P 2 , and a driver ( 19 ) for displacing the second suction member ( 23 ) to the direction of the first surface P 1 with respect to the first suction member ( 25 ). The first and second suction members ( 25 , 23 ) make it possible to cut the glass sheet ( 3 ) stably along the programmed cutting line ( 4 ) while bending the glass sheet ( 3 ). This method of bending the glass sheet into a V-shape for imparting bending stress thereto adopts traditional techniques practiced by glass craftsmen from long ago.
[0023] The cutting apparatus may additionally comprise a streak marking unit ( 2 ) for marking a streak along the programmed cutting line ( 4 ). The applying member ( 12 ) makes a crack at an end of the streak ( 5 ) and the first and second suction members ( 25 , 23 ) provide final cutting force for cutting the entire of the glass sheet ( 3 ).
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 is a front view showing a part of an apparatus for cutting a PDP substrate according to an embodiment of the present invention;
[0025] [0025]FIG. 2 is a front view showing another part of the apparatus for cutting a PDP substrate according to an embodiment of the present invention;
[0026] [0026]FIG. 3 is a front view showing still another part of an apparatus for cutting a PDP substrate according to an embodiment of the present invention;
[0027] [0027]FIG. 4 is plan view showing the cutting position of a glass sheet;
[0028] [0028]FIG. 5 is a plan view showing a position for marking a streak on a glass sheet;
[0029] [0029]FIG. 6 is a plan view showing the cutting position of a glass sheet;
[0030] [0030]FIG. 7 is a perspective view showing a PDP; and
[0031] [0031]FIG. 8 is a circuit diagram showing the modularization of the PDP.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] Preferred embodiments of the present invention will be described specifically with reference to the attached drawings. An apparatus for cutting a glass sheet, particularly an apparatus for cutting a PDP substrate according to the invention comprises a streak marking process, a crack making process, and a cutting process. The streak marking process S 1 is shown in FIG. 1, the crack making process S 2 is shown in FIG. 2, and the cutting process S 3 is shown in FIG. 3.
[0033] In the streak marking process S 1 as shown in FIG. 1, a suction unit 1 and a streak marking unit 2 are used. The suction unit 1 extends long along a programmed cutting line of a glass substrate 3 and adheres by suction to a first surface P 1 of the glass substrate 3 to hold the glass substrate 3 by suction. As shown in FIG. 4, a programmed cutting line 4 is set virtually in the suction unit 1 . The streak marking unit 2 is capable of marking a straight cut guiding streak (or groove) 5 corresponding with the programmed cutting line 4 that is assumingly drawn on one surface of the glass substrate 3 . The streak marking unit 2 is provide with a moving mechanism (not shown) for moving a diamond cutter along the programmed cutting line 4 . The diamond cutter may be substituted by a nozzle for blowing a harsh jet of steel sand against the glass surface.
[0034] In the crack making process S 2 , a pressurizing mechanism 6 is used as shown in FIG. 2. The pressurizing mechanism 6 comprises a pressurizer 7 and a pressure receiver 8 . The pressurizer 7 is constituted by an air cylinder 9 , an abutting unit 11 supported by the air cylinder 9 and abutting against the first surface of the glass sheet 3 , and a locally pressing sharp blade 12 constructed to move toward the glass sheet 3 by receiving thrust from the air cylinder 9 and accommodated inside the abutting unit 11 . The locally pressing sharp blade 12 is formed of a thin stainless plate. The stainless plate is formed from stainless steel. When the air cylinder 9 moves towards the glass sheet 3 , the abutting unit 11 comes into contact with the glass sheet 3 elastically and not with impact. The abutting unit 11 is formed as a cylindrical body of rubber itself. Alternatively, it is constructed so as to receive biasing force from a coil spring and be thereby pushed out with the advancing position restricted by the coil spring. The abutting unit 11 is formed in the shape of a closed-end cylinder, the bottom of which is effectively formed as an upper elastic plate (e.g. silicon plate) 20 that is brought into surface contact with and joined with the surface of the glass sheet 3 .
[0035] The thickness of the stainless plate is preferably in the range of 0.3 mm to 0.5 mm. The tip end (lower end) of the stainless plate is formed into a sharp point or a sharp line 13 . This sharp point or sharp line is preferably formed in a rounded (semispherical or semicylindrical) shape. The pressure receiver 8 comprises a backing plate 14 and a lower elastic plate (pressure dissipating plate) 15 . The lower elastic plate 15 is arranged between the backing plate 14 and the second surface P 2 of the glass substrate 3 . The pressurizer 7 and the pressure receiver 8 are arranged on the opposite sides, respectively, across the glass substrate 3 . The lower elastic plate 15 is preferably formed from silicon rubber having an appropriate hardness. The appropriate hardness value is preferably around 70 according to the JIS standard relating to rubber.
[0036] As shown in FIG. 5, the pressurizing mechanism 6 is arranged at a position or positions corresponding to one end site or the opposite end sites (opposite ends) of a cut guiding streak 5 . The sharp line 13 of the locally pressing sharp blade 12 positionally corresponds to a point P in the end region of the cut guiding streak 5 . The point P may be enlarged to a short line segment. An initial crack is generated in the point region or short line segment region positionally corresponding to the point P in the end region of the programmed cutting line 4 in the glass substrate 3 squeezed between the locally pressing sharp blade 12 and the backing plate 14 .
[0037] In the cutting process S 3 as shown in FIG. 3, a cutting force imparting (bending force imparting) unit 16 is used. The cutting force imparting unit 16 comprises a driven-side cutting force imparting unit 17 and a non-driven-side cutting force imparting unit 18 . The driven-side cutting force imparting unit 17 comprises a driving mechanism 19 and a suction unit 21 . The driven-side and non-driven-side cutting force imparting units 17 and 18 are arranged on the side of the second surface P 2 of the glass sheet 3 . The driven-side cutting force imparting unit 17 is arranged on the opposite side of the non-driven-side cutting force imparting unit 18 with respect to the cut guiding streak 5 corresponding with the programmed cutting line 4 .
[0038] The suction unit 21 comprises a driven-side main body 22 moved toward and away from the surface of the glass sheet 3 by receiving drive force from the drive mechanism 19 , and a driven-side suction member 23 supported by the driven-side main body 22 to move substantially integrally with the driven-side main body 22 and adhering by suction to the second surface P 2 of the glass sheet 3 . The non-driven-side cutting force imparting unit 18 comprises a non-driven-side main body 24 fixed to the glass substrate 3 and a non-driven side suction member 25 supported by the non-driven-side main body 24 to move substantially integrally with the non-driven-side main body 24 and adhering by suction to the second surface P 2 of the glass substrate 3 . The driven-side cutting force imparting unit 17 is arranged substantially in mirror symmetry with the non-driven-side cutting force imparting unit 18 with respect to the plane including the cut guiding streak 5 and orthogonal to the surface of the glass substrate 3 .
[0039] Process S 1
[0040] As shown in FIG. 1, the suction unit 1 operates to adhere by suction to the first surface P 1 of the glass substrate 3 , and the streak marking unit 2 operates to form a cut guiding streak 5 in the first surface P 1 of the glass substrate 3 . The streak marking unit 2 is moved along the programmed cutting line 4 . The programmed cutting line 4 is, as shown in FIG. 4, formed in the vicinity of one edge of one panel of three panels to be formed from the glass substrate 3 . Alternatively, as shown in FIG. 5, the line 4 is formed in the vicinity of one edge of one panel of two panels to be formed from the glass substrate 3 .
[0041] Process S 2 :
[0042] As shown in FIG. 2, the pressurizing mechanism 6 operates to bring the upper elastic plate 20 in contact with the first surface P 1 of the glass sheet 3 , and the locally pressing sharp blade 12 presses the glass plate 3 through the upper elastic plate 20 , and the sharp line 13 of the locally pressing sharp blade 12 locally applies pressure to the point region or short line segment region of the cut guiding streak 5 . The local pressure is dissipated uniformly through the upper elastic plate 20 to the local periphery of the local point or to the local sides of the local short line segment. The pressure generated by the downward movement of the locally pressing sharp blade 12 is attenuated and further dissipated within the lower elastic plate 15 .
[0043] The locally pressing sharp blade 12 presses the first surface P 1 of the glass sheet 3 with an appropriate pressure. The pressure is transmitted to the backing plate 14 via the glass substrate 3 , and the glass sheet 3 is squeezed between the sharp line of the locally pressing sharp blade 12 and the surface of the rigid backing plate 14 , whereas the lower elastic plate 15 present between the glass sheet 3 and the backing plate 14 effectively prevents excessive stress from being applied to the local site in the glass sheet 3 , namely the end region of the cut guiding streak 5 . The sharp line 13 of the locally pressing sharp blade 12 matches the end region of the cut guiding streak to cause proper stress to be generated in the glass sheet 3 through the end region. This proper stress enables the glass sheet 3 to be cut along the cut guiding streak 5 .
[0044] Process S 3 :
[0045] As shown in FIG. 3, the drive mechanism 19 of the driven-side cutting force imparting unit 17 operates to lift the driven-side main body 22 so that one of the left and right sections of the glass sheet 3 divided by the cut guiding streak 5 is thereby pushed up in the direction from the second surface P 2 to the first surface P 1 under appropriate pressure. The other of the left and right sections of the glass sheet 3 is held by suction by means of the non-driven-side suction member 25 of the non-driven-side cutting force imparting unit 18 . Relative rotational movement is generated between the left and right sections around the line including the cut guiding streak 5 and the above-mentioned initial cracks formed in the form of line segments in the end regions of the cut guiding streak 5 . This relative rotational movement causes the stress to be concentrated on the initial cracks. The stress thus concentrated causes shear stress to be produced in the initial cracks and the initial cracks are initially cut off in a shearing way. The cutting force is guided to the cut guiding streak 5 by the inductive property due to the crystallinity of glass and transmitted from one end to the other end of the cut guiding streak 5 . The glass sheet 3 is cut off by the line corresponding to the programmed cutting line 4 .
[0046] In the cutting process, the sharp line 13 directly applies pressure to the cut guiding streak 5 inducing the cutting force, while the rear side position corresponding to the site receiving the pressure is supported elastically by the lower elastic plate 15 . The pressure applied to the rear side is dissipated all over by the variability of the internal stress possessed by the lower elastic plate 15 itself. One point or one line segment in the lower elastic plate 15 serves as a fulcrum or fulcrum line when the glass sheet left and right sections divided by the programmed cutting line 4 are bent relative to each other, and this fulcrum line also constitutes a symmetry reference line for cutting off the glass sheet 3 into the left and right sections. The glass sheet 3 thus can be cut off with the cut surface formed flat along a straight line. It is preferable that, during the cutting process, either one or both of the driven-side suction member 23 and the non-driven-side suction member 25 is or are displaced to the side of the first surface P 1 of the glass sheet 3 . The cut guiding streak 5 and the cracks at the ends thereof both initially guide the cutting force as stress in the glass that is an amorphous material.
[0047] [0047]FIG. 7 shows a plasma display panel 30 as an example that is assembled by incorporating a glass substrate produced by the method described above. The plasma display panel 30 comprises a front frame board 31 and a rear frame board 32 . The front frame board 31 is formed of a first transparent glass substrate 33 manufactured by the PDP substrate cutting method of the invention, a transparent dielectric layer 34 joined to the rear side of the first transparent glass substrate 33 , and a surface protective layer 35 joined to the rear side of the transparent dielectric layer 34 . A scanning electrode 36 and a sustaining electrode 37 are arranged between the first transparent glass substrate 33 and the transparent dielectric layer 34 . The scanning electrode 36 and the sustaining electrode 37 are disposed parallel with each other. The scanning electrode 36 and the sustaining electrode 37 are respectively constituted by a transparent electrode and a bus electrode. The transparent dielectric layer 34 covers the scanning and sustaining electrodes 36 and 37 .
[0048] The rear frame board 32 is formed of a second transparent glass substrate 38 manufactured by the PDP substrate cutting method of the invention, a white dielectric layer 39 joined to the front side of the second transparent glass substrate 38 , and a plurality of partitions 41 joined to the front side of the white dielectric layer 39 . The partitions 41 define display cells. A data electrode 42 is arranged between the second transparent glass substrate 38 and the white dielectric layer 39 . The data electrode 42 intersects orthogonally with the scanning electrode 36 and the sustaining electrode 37 . The white dielectric layer 39 covers the data electrode 42 . A phosphor layer 43 is formed on the side faces of the partitions 41 and on the front surface of the white dielectric layer 39 for converting ultraviolet rays generated by the discharge of discharge gas into visible light. The phosphor layer 43 is color coded with three primary colors of R, G, and B for each cell.
[0049] The front frame board 31 and the rear frame board 32 are assembled fixedly with a gap defined therebetween. The width of the gap is designed to be about 100 μm. The side peripheries of the front and rear frame boards 31 and 32 are tightly sealed with a seal material, so that the gap forms a sealed space. The sealed space is filled with helium, neon, xenon, or mixture gas including any of these. The rear frame board 32 is provided with a vent tube (not shown) passing through the second transparent glass substrate 38 and opening into the sealed space. The outside end opening of the vent tube is connected to a gas discharging and filling apparatus (not shown), so that gas such as air or the like is sucked and discharged through the opening, and then the above-mentioned gas is injected into the above-mentioned sealed space. After the injection, the opening is chipped on by heating means so that the open end is closed to hermetically enclose the injected gas within the sealed space.
[0050] It is important that the side peripheries 44 of the first and second transparent glass substrates 33 and 38 of the plasma display panel 30 , where such hermetical seal is required, are formed as a flat face, not as a curved face, intersecting orthogonally to the first surface P 1 described above. In this regard, the side periphery 44 is formed to be an orthogonal plane by the PDP substrate cutting method according to the present invention. The side periphery 44 thus formed is coated with a fusing material.
[0051] [0051]FIG. 8 shows a plasma display device 50 including a plasma display panel 30 assembled as described with reference to FIG. 7. The plasma display device 50 is modularized. The modularized plasma display device 50 comprises an analog interface 51 , and a plasma display panel module 52 .
[0052] The analog interface 51 comprises a Y/C separator circuit 53 having a chroma decoder, an A/D converter circuit 54 , an image format converting circuit 55 , a synchronous signal control circuit 57 having a PLL circuit 56 , a reverse y converter circuit 58 , a system control circuit 59 , and a PLE control circuit 61 . The analog interface 51 converts a received analog video signal (an analog RGB signal 62 and an analog video signal 63 ) into a digital video signal 64 and outputs this digital video signal 64 to the plasma display panel module 52 . More specifically, an analog video signal 63 transmitted by a TV tuner is decomposed into luminance signals of colors R, G, and B by the Y/C separator circuit 53 , and then converted into a digital video signal 64 by the A/D converter circuit 54 . If the pixel constitution of the plasma display panel module 52 is different from that of the analog video signal 63 , the digital video signal 64 is converted into an appropriate image format by the image format converting circuit 55 .
[0053] The analog video signal 63 does not include a sampling clock or data clock signal for A/D conversion. The PLL circuit 56 included in the synchronous signal control circuit 57 generates a sampling clock 65 and a data clock signal 66 with reference to a horizontal synchronizing signal supplied thereto at the same time with the analog video signal 63 . The sampling clock 65 and the data clock signal 66 are outputted from the analog interface 51 and received by the plasma display panel module 52 . The PLE control circuit 61 increases the display luminance if the average luminance level is not more than a predetermined value, and decrease the display luminance if the average luminance level is not less than the predetermined value. The system control circuit 59 generates various types of control signal 67 . The control signal 67 is outputted by the analog interface 51 and received by the plasma display panel module 52 .
[0054] The plasma display panel module 52 comprises a digital signal processing/controlling circuit 68 , a panel part 69 , and a module power source circuit 71 having a built-in DC/DC converter. The panel part 69 includes the plasma display panel 30 described above. The digital signal processing/controlling circuit 68 comprises an input interface signal processing circuit 72 , a frame memory 73 , a memory control circuit 74 , and a driver control circuit 75 . The average luminance level of the digital video signal 64 inputted to the input interface signal processing circuit 72 from the analog interface 51 is calculated by an input signal average luminance level calculating circuit (now shown) provided in the input interface signal processing circuit 72 and outputted as data of an appropriate number of bits (e.g. 5 bits). PLE control data 76 set by the analog interface 51 in correspondence with the average luminance level is inputted to a luminance level control circuit (not shown) in the input interface signal processing circuit 72 .
[0055] The digital signal processing/controlling circuit 68 processes the above-mentioned signal in the input interface signal processing circuit 72 and transmits the processed control signal 77 to the panel part 69 . At the same time as the transmission of the processed control signal 77 , the memory control circuit 74 and the driver control circuit 75 generate a memory control signal 78 and a driver control signal 79 , respectively, and transmit these signals to the panel part 69 .
[0056] The panel part 69 comprises the plasma display panel 30 , a scanning driver 81 (mounted integrally in the panel part 69 ) for driving the scanning electrode 36 (see FIG. 7), and a data driver 82 (mounted integrally in the panel part 69 ) for driving the data electrode 42 (see FIG. 7). The panel part 69 further comprises a high-voltage pulse circuit 83 for supplying pulsed voltage to the plasma display panel 30 , scanning driver 81 , and data driver 82 . The high-voltage pulse circuit 83 is arranged and packaged at a plurality of positions of the panel part 69 as a part of the panel part 69 .
[0057] The plasma display panel 30 has 1365×768 pixels arrayed in 1365×768 grid. In the plasma display panel 30 , the scanning driver 81 controls the scanning electrode 36 and the data driver 82 controls the data electrode 42 , so that control is performed to turn on or not to turn on a predetermined number of pixels from among the above-mentioned number of pixels, and prescribed display is thereby performed.
[0058] A logic power supply (not shown) supplies logic power to the digital signal processing/controlling circuit 68 and the panel part 69 through a power input terminal 84 . The module power source circuit 71 is supplied with DC power from a display power supply (not shown) through another power input terminal 85 and supplies the DC power to the panel part 69 after changing the voltage thereof to a predetermined voltage.
[0059] The plasma display panel 30 , the scanning driver 81 , the data driver 82 , and the high-voltage pulse circuit 83 are arranged and packaged, together with a power collecting circuit 86 , on a single substrate constituting the main body of the panel part 69 . In the panel part 69 , the main body, the plasma display panel 30 , the scanning driver 81 , the data driver 82 , the high-voltage pulse circuit 83 , and the power collecting circuit 86 are constructed integrally. The digital signal processing/controlling circuit 68 is separated from the panel part 69 and formed mechanically independently from the panel part 69 .
[0060] The module power source circuit 71 is separated from the digital signal processing/controlling circuit 68 and the panel part 69 and formed mechanically independently therefrom. The digital signal processing/controlling circuit 68 , the panel part 69 , and the module power source circuit 71 are assembled as a single module. The plasma display panel module 52 constitutes the single module thus assembled. The analog interface 51 is separated from the plasma display panel module 52 and is formed mechanically independently therefrom. The plasma display panel module 52 is electrically connected to the analog interface 51 by electric wiring for transmitting the control signal 67 , the digital video signal 64 , the sampling clock 65 , the data clock signal 66 , the PLE control data 76 , and other signals.
[0061] The analog interface 51 and the plasma display panel module 52 are, after being formed separately, incorporated and fixedly supported in the housing of the plasma display device to build up the plasma display device 50 . In the plasma display device 50 modularized in this manner, the analog interface 51 and the plasma display panel module 52 can be manufactured separately from other equipment components. Therefore, if the plasma display device 50 breaks down, the plasma display device 50 with failure can be replaced with a new plasma display device 50 while leaving the plasma display panel module 52 as it is, so that the repair of the plasma display device 50 can be simplified and the time required for the repair can be shortened.
[0062] With the method and the apparatus for cutting a PDP substrate and the method for manufacturing a PDP device according to the present invention, it is possible to produce a glass substrate having a cut surface that is highly vertical to the substrate surface and hence to ensure good quality for the PDP devices produced using the glass substrate.
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A linear groove is formed in a glass sheet along a programmed cut line that is set for the glass sheet, and pressure is applied locally to an end of the groove. The pressure is not applied equally uniformly to the whole groove but applied locally to the end of the groove, where an initial crack is induced by the pressure applied thereto. The initial crack is guided by the groove so that the cracking force is propagated inductively along the groove. Distribution of stress in the glass corresponding to the cracking force thus propagated is concentrated locally to a face intersecting orthogonally to the surface of the glass sheet. The face to which the stress is concentrated intersects substantially orthogonally with the surface of the glass sheet. The glass sheet manufactured in this manner can be utilized effectively as a material of a PDP.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of copending U.S. Application Ser. No. 818,038, filed July 22, 1977, now U.S. Pat. No. 4,172,043 which is a continuation-in-part of U.S. Application Ser. No. 734,775, filed Oct. 22, 1976, now abandoned, which was a division of U.S. Application Ser. No. 567,043, filed Apr. 10, 1975, now U.S. Pat. No. 4,005,584.
BACKGROUND OF THE INVENTION
This invention relates to novel absorption pairs for absorption heating and cooling.
In view of diminishing fossil fuel supplies, and hence, increasing fuel costs, there is a need to minimize the amount of fuel society consumes to heat habitable space.
The heat pump concept, wherein available energy is taken from an ambient source such as outside air, and combined with fuel energy to heat space, is not new. Existing concepts include electrically driven-vapor compression heat pumps and absorption heat pumps. The latter require an absorption pair which comprises a solvent and a solute wherein the solvent remains a liquid, which may be a solution, throughout the operation of the apparatus, and the solute having a liquid and vapor phase in the cycles of the operation. The solute must be soluble in the solvent and must be readily separable as a vapor from the solvent by means of evaporation. In addition, the solute must be suitable for condensation from the vapor back to a liquid form. In general, all absorption heating apparatus require essentially the same parts and function in essentially the same way regardless of the particular solute and solvent used. Nevertheless, heat pumps as disclosed in U.S. Pat. Nos. 4,106,309, 4,127,009, 4,127,010 and 4,127,993 of B. A. Phillips are preferred. The major components of the apparatus are a generator, condenser, evaporator, absorber and absorption pair (also called absorber pair). The solute passes through all units and the solvent, sometimes also known as the absorbent, is confined to movement through the generator and absorber.
In operation, a mixture of absorbent and solute is heated in the generator to boil off most of all of the solute which rises as a vapor through a connecting conduit to the condenser. The mixture may be heated in the generator by any suitable means such as a gas flame, geothermal heat, solar heat or warm water.
The generator and condenser operate at relatively high pressure, so that condensing temperature of the solute is sufficiently high to permit rejecting the latent heat emitted by the condensing solute to outside air or cooling water passing through or around the condenser.
The liquid solute leaving the condenser passes through a conduit to a throttling valve (or its equivalent), through the throttling valve and through another conduit to the evaporator. The throttling valve throttles the liquid solute to a lower pressure so it will boil at a relatively low temperature in the evaporator and thus absorb heat from air or water passing through or around the evaporator.
The vaporized solute passes from the evaporator through a conduit to the absorber where heat of mixing is emitted (preferably to cooling water passing therethrough) as it is dissolved in cool absorbent which has been carried to the absorber by means of a conduit connecting the absorber with a generator outlet. The mixture of absorbent and solute resulting in the absorber then passes through a conduit to the generator where it is reheated to continue the process.
Any suitable material of construction for the apparatus may be used which can withstand the encountered temperature, pressure and corrosive properties, if any, of the solvent and solute. For the present compositions, aluminum, copper and their alloys are preferred. It is desirable, however, that minor components of a heat pump system (such as pump parts) be made of steel or other metals. Thus, it is desirable for the solute/solvent system to have good stability in contact with steel as well as with aluminum and copper.
Such a heat absorption apparatus is particularly desirable since moving parts, if any, are minimal when compared with the moving parts found in electrically driven-vapor compression heat pumps.
Unfortunately, the known solute/solvent systems for heat pumps have serious disadvantages. The most common solute/solvent pair (absorber or absorption pair) is ammonia/water. The ammonia/water pair has a disadvantage since the heating efficiency of apparatus utilizing the ammonia/water absorber pair is not as high as desired; i.e. the coefficient of performance (COP) practically attainable is generally less than about 1.30 at low generator temperature, i.e. below 180° F., and at high generator temperatures, i.e. 220° F., is generally below about 1.40. COP is a measure of the efficiency of the absorption cycle and is the ratio of the heat output to the energy input. The ammonia/water combination has additional disadvantages. Water is highly volatile, thus preventing complete separation of the ammonia from the water in the generator at high generator temperatures. The condensing pressure required to condense the ammonia is undesirably high, thus requiring equipment capable of withstanding such pressure.
The only other presently commercial absorber pair is water/lithium bromide wherein water is used as the solute and lithium bromide is used as the absorbent. The water/lithium bromide absorber pair (and the related water/lithium chloride absorber pair) has undesirable characteristics. For example, water as a solute is limited to an evaporation temperature of above about 32° F., which is its freezing point. Lithium bromide is not sufficiently soluble in water to permit the absorber to be air cooled. The extremely low pressures in the system require large vapor conduits. Unless the system is precisely controlled, lithium bromide can crystallize and cause fouling of the system and the generator temperature cannot efficiently operate below 180° F. nor above 215° F. Additionally, aqueous lithium bromide solutions are corrosive, thus requiring special inhibitors and alloys for suitable apparatus.
Other absorber pairs which have been suggested have not been commercially accepted due to one or more disadvantages. Such disadvantages include a lack of sufficient affinity of the absorbent for the solute vapor, thus preventing sufficient absorption of the solute vapor to draw in and compress the solute. The absorber pairs have frequently not been mutually soluble over the whole range of operating conditions, thus permitting crystallization and the formation of solid articles which make it difficult or impossible for proper fluid circulation. The absorbent has frequently been too volatile, thus preventing the refrigerant vapor leaving the generator to be adequately purified. When absorbent evaporates from the generator, the efficiency of the system is frequently substantially reduced since energy input is wasted in evaporation. Additionally, the absorbent pairs previously suggested are frequently unstable, cause corrosion of the apparatus, are toxic or are highly flammable. Absorption pairs suggested in the prior art frequently have unacceptably high or unacceptably low working pressures. The working pressures should be as near to atmospheric pressure as possible to minimize equipment weight and minimize leaking into or out of the system. In addition, pressure difference between the high side and low side is frequently too high to facilitate circulation of the solution. The solutes suggested in the prior art frequently have a latent heat of evaporation which is unacceptably low, thus requiring large quantities of fluids to be circulated and the coefficient of performance of other absorber pairs suggested in the prior art is usually too low for serious consideration in commercial apparatus.
Some absorber pairs including a halogenated hydrocarbon solute (refrigerant) and an organic absorbent have been explored over the years for absorption refrigeration. Although certain specific absorber pairs wherein the absorbent included a furan-type ring had been proposed in U.S. Pat. No. 2,040,902 as a part of a program exploring numerous potential absorber pairs, no further discussion of furan-type absorbents has appeared in the art. Instead, subsequent exploratory work with organic absorbents has concentrated on acyclic glycol ethers and particularly on DMETEG (dimethoxytetraethylene glycol) and the ethyl ether of diethylene glycol acetate. More recently, and until the present invention, exploratory work on organic absorbents for halogenated hydrocarbon refrigerants has apparently lain dormant.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with this invention, there is provided novel absorber pairs for absorption heating and refrigeration which have high coefficients of performance, have good stability, cause little corrosion, have relatively high flash points, operate at approximately atmospheric pressure and have relatively low toxicity. The high coefficient of performance is due to a strong affinity between the solute and solvent, good mutual solubility at absorber conditions and ease of separation at generator conditions, good absorbent volatility and a solute having a high latent heat of vaporization.
The new and useful compositions of matter of the invention comprises from about 4 to about 60 weight percent of 1-chloro-2,2,2-trifluoroethane dissolved in about 40 to about 96 weight percent of a furan ring-containing compound having a boiling point between about 140° C. and 250° C. and being of the formula: ##STR1## wherein R 1 is independently at each occurrence H; lower alkyl; lower alkoxy; phenyl; lower alkylene phenyl; hydroxy containing lower alkyl; lower alkyl carboxy; alkoxy alkyl of from 2 through 6 carbon atoms; lower alkylene carboxylate of from 2 through 6 carbon atoms; fluorine or chlorine; a is independently at each occurrence an integer of 1 or 2; and Z is a single or double bond; provided that, when Z is a single bond, a is 2, when Z is a double bond, a is 1, and provided that the compound contains at least one R 1 group having an oxygen atom which has a single bond to a carbon atom.
Preferred compositions are ones in which the absorbent is as alkyl tetrahydrofurfuryl ether and especially ethyl tetrahydrofurfuryl ether. Exemplary are tetrahydrofurfuryl ethers of the formula (C 4 H 7 O)CH 2 OR where R is alkyl of 1-4 carbons.
DETAILED DESCRIPTION OF THE INVENTION
In general, in accordance with this invention, the solvent used in the absorption pair is an asymmetrical furan ring-containing compound having a boiling point between about 140° and 250° C. The compound has the general formula ##STR2## wherein R 1 , a and Z are as previously defined and the compound contains at least one R 1 group having an oxygen atom which has a single bond to a carbon atom.
Lower alkyl, lower alkoxy, lower alkyl carboxy, or lower alkylene as used herein means alkyl, alkoxy or alkylene of from 1 through 5 carbon atoms. Examples of lower alkyl groups are --CH 2 CH 3 ; --CH 3 ; ##STR3## and --CH 2 CH 2 CH 3 .
Examples of lower alkoxy groups are --OCH 3 ; --OCH 2 CH 3 and ##STR4##
Phenyl groups are those groups containing a phenyl ring which is unsubstituted or substituted with methyl, ethyl, hydroxy, methoxy, ethoxy, methyl methoxy, fluorine or chlorine. Examples of phenyl groups are ##STR5##
Lower alkylene phenyl groups are phenyl groups connected to the furan ring by a lower alkylene group. Examples of such groups are ##STR6##
Examples of hydroxy containing lower alkyl groups are --CH 2 OH; --CH 2 CH 2 OH and ##STR7##
Examples of lower alkyl carboxy groups are --COOH; --CH 2 COOH and --CH 2 CH 2 COOH.
Examples of alkoxy alkyl groups, i.e., those containing 2 to 6 carbon atoms, are --CH 2 OCH 3 ; --CH 2 OCH 2 CH 3 ; --CH 2 OCH 2 CH 2 CH 3 ; --CH 2 OCH 2 CH 2 CH 2 CH 3 and CH 2 CH 2 OCH 3 . Preferred alkoxy alkyl groups are those containing either 5 or 6 carbon atoms due to higher efficiency at high generator temperature and due to increased stability, those alkoxy alkyl groups wherein the intermediate alkyl portion, i.e. that portion attached to the furan ring contains 2 or 3 carbon atoms. When the intermediate alkyl group is ethyl the furan ring compound unexpectedly exhibits improved solubility for the fluorocarbon.
Examples of lower alkylene carboxylate groups, i.e., those containing 2 to 6 carbon atoms, are ##STR8##
It is theorized that the boiling point of the simple furan ring is increased by adding an alkyl or an alkoxy group to the furan ring to form an asymmetrical molecule. The added group should preferably permit an increase in the negative charge on the furan ring oxygen atom.
The furan ring-containing compounds employed in the present invention are usually characterized by high flash points which reduce the flame hazard when they are used.
Asymmetrical as used in relation to the furan ring-containing compound means either that at least one of the R 1 groups at the 2 position on the furan ring is different from both of the R 1 groups at the 5 position or at least one of the R 1 groups at the 3 position is different from both of the R 1 groups at the 4 position. In the preferred furan ring compounds, at least one of the R 1 groups at the 2 position is different from both of the R 1 groups at the 5 position.
Alkyl as used above means an aliphatic hydrocarbon radical in which the hydrogens may be wholly or partially substituted by fluorine or chlorine.
The compound should preferably contain at least one R 1 group having an oxygen atom which is bonded on one side to a carbon atom or a hydrogen atom. At high generator temperatures, carboxy groups, particularly free rather than esterified carboxy groups, should be avoided since such groups tend to increase the corrosiveness of the compound and tend to decompose more rapidly than other groups. Carboxy groups are, however, suitable for compounds which will be used at low generator temperatures, i.e., below 225° F. The more preferred R 1 groups are those containing an alochol or either oxygen atom.
The foregoing furan ring-containing compounds may be prepared by known procedures. Detailed discussions of the chemistry of furan and its derivatives are found in Chapter 4 of Heterocyclic Compounds Volume I, edited by Robert C. Elderfield, Wiley and Sons, Inc., 1950 and at pages 377 through 490 of Advances in Heterocyclic Chemistry Volume 7, edited by A. R. Katritzky and A. J. Boulton, Academic Press, 1966.
Examples of such synthesis are described in columns 7-12 of U.S. Pat. No. 4,005,584, which disclosure is incorporated herein by reference.
Representative of compositions according to the present invention are compositions of 1-chloro-2,2,2-trifluoroethane (refrigerant 133a) and ethyl tetrahydrofurfuryl ether (ETFE). The following comparisons are made between this composition and similar compositions of dichlorofluoromethane (refrigerant 21) and ETFE:
______________________________________Solubility ofrefrigerant inETFE at: 133a-ETFE 21-ETFE______________________________________110° F. (43° C.) 37% (1) 43% (1)250° F. (121° C.) 24% (2) 29% (2)300° F. (150° C.) 13.5% (2) 18% (2)350° F. (177° C.) 7% (2) 9% (2)400° F. (204° C.)Latent Heat ofVaporization ofRefrigerant at: 133a 21______________________________________10° F. (-18° C.) 93.97 107.5040° F. (4° C.) 90.17 103.63______________________________________ (1) Under the vapor pressure of solute at 40° F. (2) Under the vapor pressure of solute at 120° F.
______________________________________ Good GoodStability of: For* Chloride** For* Chloride**______________________________________ETFE-AluminumRefrigerant at350° F. (177° C.) 180-210 8.7 30-90 13.5 days days______________________________________ *An evaluation of "good" or better meant that the metal strip was still shiny and that the solution was only a pale color. After the indicated period, the evaluation was "fair" or "poor" as indicated below in Example 3. **Parts per million chloride as determined by a chloride analyzer after 210 days.
EXAMPLE 1
The operation of 133a-ETFE under air-conditioning of a 110° F. (43° C.) absorber, a 120° F. (49° C.) condenser, a 40° F. (4° C.) evaporator and a generator of 300° F. (150° C.) is simulated by the following calculations based upon one ton of refrigeration.
Assuming the flows were 179.4 lbs/hr refrigerant through the condenser and evaporator, 481 lbs/hr of weak liquor from the generator to the absorber and 660 lbs/hr of rich liquor from the absorber to the generator. Heat inputs would be 25,358 BTUs/hr into the generator and 12,000 BTUs/hr into the evaporator. Heat outputs would be 16,170 BTUs/hr from the absorber and 21,185 BTUs/hr from the condenser. 36,168 BTUs/hr would be transferred from the weak liquor to the rich liquor (in a liquid heat exchanger). The COP c would be 12,000 divided by 25,358 or 0.473.
EXAMPLE 2
Similar calculations made at generator temperatures of 250° F. and 350° F. produced calculated COP c values of 0.464 and 0.452 respectively. If the evaporator temperature is lowered to 0° F., a very low COP c value is obtained (0.155) for a 300° F. generator and a low COP c value is obtained (0.366) for a 350° F. generator. The results of these calculations are displayed in Table 1 along with similar results for refrigerant 21:
TABLE 1______________________________________40° F. 0° F.Evaporator 21 133a % loss 21 133a % loss______________________________________Generator250° F. .566 .464 17.9 -- -- --300° F. .596 .473 20.6 .344 .155 54.9350° F. .571 .452 20.8 .456 .366 19.7400° F. .546 -- -- -- -- --______________________________________
Thus, except for conditions of 300° F. generator and 0° F. evaporator, the loss is about 20%. Under conditions of 0° F. evaptorator, one can merely operate at a higher generator temperature to avoid large losses. In actual applications, COP losses resulting from a switch from refrigerant 21 to refrigerant 133a have been less than 10% and have, accordingly, not made performance uncompetitive as might have been expected from the published literature for DMTEG-133a or even from the calculated values.
EXAMPLE 3--STABILITY MEASUREMENTS WITH ALUMINUM
Stability testing was conducted on mixture of 21 and, in some cases, a stabilizer with refrigerants 21 and 133a. Samples of 20 mL ETFE and about 6 grams refrigerant were placed in test tubes with a 5 mm diameter, 10 cm along rod of aluminum 1100. Each tube was sealed and placed in an over at 177° C. (350° F.) for successive 30 day periods. The color of the liquid and appearance of the strips were recorded at 30, 60, 90, 180 days and 210 days when the liquid was analyzed by chloride analyzer for chloride ions. The results are displayed in Table 2, with the symbol "TDP" representing 1500 ppm triisodecylphosphite stabilizer added to each tube.
TABLE 2______________________________________Stability With Aluminum at 350° F. 210 Days 30 90 180 ChlorideETFE Days Days Days Color (ppm)______________________________________+133a E G G F 8.7+21 G F F P 13.5+133a + TDP E G G F 7.4+21 + TDP G G F F 6.6______________________________________ E = excellent G = good F = fair P = poor
EXAMPLE 4--STABILITY MEASUREMENTS WITH STEEL
Tubes were prepared with a tab of cold-rolled steel and a liquid mixture of 20 weight % of refrigerant 133a and 80 weight % ETFE. Samples kept at 75° F. (24° C.) for 60 days showed no visible change. Samples kept at 400° F. (204° C.) for 60 days showed some blackening of the rods and formation of a precipitate. Refrigerant 133a outperforms refrigerant 21 in this test.
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1-chloro-2,2,2-trifluoroethane (refrigerant 133a) is dissolved in a furan-derivative absorbent, and especially an ether of tetrahydrofurfuryl alcohol, to form an absorption refrigerant pair composition. It exhibits a good combination of performance, capacity, stability, low toxicity and convenient operating pressures. These compositions are useful in methods of absorption refrigeration, cooling and heating and especially in an absorption heat pump.
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