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TECHNICAL FIELD
The present invention regards a supplemental removable outersole for footwear. More particularly the present invention regards a supplemental removable outersole having athletic spikes or grips that can be releasably secured to the sole of footwear for athletic use.
BACKGROUND
Cleated or spiked athletic shoes often have their spikes or cleats secured to a rigid flat sole. These rigid soles impart at least two functions. They provide an outside surface for the spikes or cleats to be mounted to and they provide a foundation for the construction of the upper portions of the shoe. The outside surface of the sole, exposed to the outside environment, is typically an uncovered and exposed rigid plastic designed to withstand external impacts. Comparatively, the inside surface of the sole, in contact with an athlete's foot, is typically covered with a layer of cloth or other material to provide a degree of cushioning. Despite this covering, however, the inside surface of the rigid flat sole may irritate or otherwise injure the foot of the wearer. For athletes, who wear these athletic shoes over prolonged periods of time, their feet may rub against the unyielding rigid inside surface, grazing their feet and leading to the formation of calluses and blisters. In addition, the flat bottoms can promote premature foot fatigue and flatten the wearer's foot due to the lack of arch support. Moreover, in younger athletes, whose feet are still developing, the problem is even more troublesome as the lack of support may not only irritate and fatigue the athletes foot but may also lead to irreparable injuries of their feet.
SUMMARY OF THE INVENTION
The present invention is directed to supplemental removable outersoles for athletic footwear. In one embodiment of the present invention, a removable outersole covering for the treaded bottom of athletic footwear is provided. In this embodiment the outersole includes: an elastically deformable band defining a continuous loop, the band having a top edge and a bottom edge, the bottom edge of the band forming the shape of the perimeter of the treaded bottom of the athletic footcovering, a sole surface coupled to the bottom edge of the band, the sole surface configured in the shape of the treaded bottom of the athletic footcovering; and a plurality of sport cleats protruding from the bottom side of the sole surface.
In another embodiment of the present invention athletic footwear having a top surface is provided. This footwear may include a permanent sole; a removable outersole covering the permanent sole; a plurality of sport cleats protruding from the removable outersole; and an elastically deformable band secured to the entire perimeter of the removable outersole, the elastically deformable band sized to removably secure the removable outersole to the permanent sole.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a rear side isometric view of an athletic footcovering and removable supplementary outersole in accord with an embodiment of the present invention.
FIG. 2 is a rear side isometric view of the athletic footcovering and removable supplementary outersole from FIG. 1 after the supplementary outersole has been secured to the athletic shoe.
FIG. 3 is a rear side isometric view of a removable supplementary outersole and a rear bottom isometric view of an athletic footcovering in accord with an alternative embodiment of the present invention.
FIG. 4 is a front plan view of the athletic shoe and removable supplementary outersole of FIG. 3 .
FIG. 5 is a rear plan view of the athletic footcovering and the removable supplementary outersole of FIG. 3 .
FIG. 6 is an isometric top view of a removable supplementary outersole in accord with another alternative embodiment of the present invention.
FIG. 7 is an isometric top view of a removable supplementary outersole mounted on an athletic footcovering in accord with another alternative embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1 is a side isometric view of athletic footwear or footcovering 10 and a supplementary removable outersole 15 in accord with an embodiment of the present invention. The athletic footcovering 10 in this embodiment has a toe cap 13 , a bottom tread 12 , and a side molding 11 , all made from injected rubber. These components may also be made from polyvinyl chloride and certain durable foams, while the toe cap may also be made from canvas. Moreover, other materials may also be used to manufacture these components.
The removable supplementary outersole 15 in this embodiment has a sole plate 17 with a bottom surface 19 having cleats 18 screwed to it. The supplementary outersole 15 also has a side elastic border 16 with a top edge 101 and a bottom edge 102 , the bottom edge 102 being glued to the plate 17 . The plate 17 in this embodiment has been made from a rigid plastic while the elastic border has been made from rubber. The removable supplementary outersole 15 has been sized to fit underneath and elastically secure itself to the bottom of the athletic footcovering 10 .
In use the removable supplementary outersole 15 may be placed beneath the athletic footcovering 10 as shown by arrows 14 . The elastic border may then be stretched while the bottom tread 12 of the athletic footcovering 10 is slid towards and comes in contact with the top surface of the plate 17 . Once the tread 12 has been firmly placed against the top surface of the plate 17 the elastic border may be released and the athletic footcovering and removable outersole combination is ready for use. By adding the supplementary removable outersole 15 to the athletic footcovering 10 , the athletic footcovering may now be worn as a cleated shoe. Thus, the athletic footcovering may be worn either with or without the removable outersole 15 . When the outersole 15 is not on the athletic footcovering the athletic footcovering may be used for day to day activities and when the removable outersole 15 is added to the athletic footcovering 10 it may be used for athletic competitions requiring spikes of cleats such as soccer, golf, and football. The treaded bottom of the athletic footcovering allows the shoe to also be worn without the outersole 15 . This treaded surface may include rubber, foam and other surfaces and may be both patterned and unpatterned.
The plate 17 is sized for the specific athletic footcovering 10 in this embodiment although it may be sized to cover a variety of athletic footcoverings, the sizes changing in both configuration and in foot size. The outersole 15 may be sized to fit multiple configurations by increasing the height of the elastic border or otherwise adjusting its configuration to conform to a wider variety of athletic footcoverings including both sneakers and sandals as well as other types of athletic footwear.
FIG. 2 is a side isometric view of the athletic footcovering 10 and the supplementary removable outersole 15 after they have been combined in accord with an embodiment of the present invention. As can be seen in FIG. 2 the top edge 101 of the elastic border 16 does not extend past the top rim of the side molding 11 of the athletic footcovering 10 . It is preferred in this embodiment to push the tread 12 into the outersole 15 until it come in contact with the top surface of the plate 17 which is hidden behind the elastic border and beneath the treads 12 .
FIG. 3 is a bottom isometric view of an athletic footcovering 20 and a top isometric view of a supplementary removable outersole 25 in accord with an alternative embodiment of the present invention. Evident in FIG. 3 is the side molding 21 , the treads 22 , the cleats 28 , the elastic border 26 , the top surface of the plate 27 and the bottom surface of the plate 29 .
FIG. 4 is a front elevation of the athletic footcovering 20 and removable outersole 25 of FIG. 3 . The profile of the cleats 28 is clearly evident in this view. Also evident are the side molding, the treads 22 , the elastic border, and the top surface of the plate 27 .
Depending upon the desired sport, the cleats located underneath the plate may be removed and substituted for metal spikes, soft spikes of any other gripping system that may be appropriate for the sport to be played.
Moreover, while an athletic footcovering has been described in the above embodiments a low-heeled shoe may instead be used with the removable outersole being tiered to accommodate the heel. The removable outersole may, in this embodiment, contain soft spikes. Thus, in this embodiment, the removable outersole my convert an ordinary street shoe into a shoe suitable for golf.
FIG. 5 is a rear elevation of the athletic footcovering 20 and removable outersole 25 of FIG. 3 . As is evident in this view, the elastic border 26 has a tapered cross-section. Also evident in this view is that the threads 22 rest against the top surface 51 of the plate 27 in this embodiment and that the elastic border may be the sole means for attaching the outersole 25 to the footcovering 20 .
FIG. 6 is a top isometric view of a supplementary removable outersole 60 in accord with another alternative embodiment of the present invention. The cross straps 61 , anchored to the elastic border 66 is clearly evident. These straps 61 may be employed in this embodiment to further secure the outersole 60 to a shoe. The straps 61 may be made from any elastic material and may be glued to side of the border 66 or may be releasably secured to the elastic border through a snap or other securement means. Moreover, the straps 61 illustrated in FIG. 6 may also be laces 61 or other securement means that may be used to supplement the attachment of the removable outersole 60 to a shoe (which is not shown).
FIG. 7 is a rear side isometric view of another alternative embodiment of the present invention. In this embodiment the supplemental releasable outersole 70 is further secured to the athletic footcovering 79 with a toe cap 71 in addition to the strap 72 . The toe cap 71 working in conjunction with the strap 72 can be configured in innumerable configurations to help secure the releasable outersole 70 to the athletic footcovering 79 . The toe cap is advantageous because it can facilitate the securement of the outersole 70 to several lengths of shoe. The toe cap 71 and the strap 72 may be formed in conjunction with the rest of the releasable outersole 70 or alternatively the toe cap 71 and the strap may be formed separately from the outersole 70 and may later be secured to the shoe with snaps or some other fastening means.
Also evident in FIG. 7 are the elastic border 73 and the turf knobs 74 . As can be seen the elastic border is taller in this embodiment than in the previous embodiments and completely covers the lower portion of the athletic footcovering. In addition, rather than having the spikes or cleats of the previous embodiments the removable sole 70 in this embodiment contains a plurality of knobs 74 protruding from its lower surface. These knobs are preferably formed as surface protrusions during the manufacturing of the removable outersole 70 .
A supplemental removable outersole for athletic footwear has been provided. While various embodiments have been presented above other embodiments are also plausible without straying from the spirit or scope of the present invention.
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A removable outersole covering for the treaded bottom of an athletic footcovering is provided in one embodiment of the present invention. In this embodiment the outersole includes an elastically deformable band defining a continuous loop, the band having a top edge and a bottom edge, the bottom edge of the band forming the shape of the border of the treaded bottom of the athletic footcovering, a sole surface coupled to the bottom edge of the band, the sole surface configured in the shape of the treaded bottom of the athletic footcovering; and a plurality of sport cleats protruding from the bottom side of the sole surface.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent application Ser. No. 13/971,677 filed Aug. 20, 2013, now U.S. Pat. No. 9,231,921, the contents of which are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a system and architecture for securing computer systems having non-secure subsystems.
BACKGROUND OF THE INVENTION
[0003] U.S. Pat. No. 8,813,218, the contents of which are incorporated herein by reference in their entirety, dramatically advanced the state of the art of computer system security. Nevertheless, certain challenges and opportunities for improvement remain.
[0004] Conventional computing devices typically include one to many conventional types of subsystems such as storage, networking, audio/video, I/O interfaces, etc. However, these subsystems are typically inherently unsecure and vulnerable to many different types of threats.
[0005] For example, as shown in FIG. 1A , a conventional non-secure computer 150 (e.g. a desktop or notebook computer) includes a host system 102 , typically including a CPU running an operating system, application software and device drivers. Computer 150 further includes devices 106 associated with various computer subsystems such as an internal drive 106 - 1 (e.g. HDD or SSD), audio/video input and output devices 106 - 2 (e.g. display, speakers, etc.), I/O ports and devices 106 - 3 (e.g. USB, Firewire, etc.) and network interfaces 106 - 4 (e.g. WiFi, Ethernet, etc.).
[0006] The lack of security over the subsystems associated with these devices results in many vulnerabilities. More particularly, in connection with internal drive 106 - 1 , data stored on it is typically non-encrypted. This means that if it is discarded or surreptitiously inspected (e.g. by someone stealing computer 150 or by virus software on host 102 ), its contents can be retrieved, including any sensitive, private or confidential data. Further, many users do not regularly back up their data, rendering the data on drive 106 - 1 vulnerable to drive or system failure.
[0007] Even when data is encrypted and/or backed-up, its level of security depends on the specific operating system and application. Further, if encryption keys are also stored locally on computer 150 they can be accessed and used surreptitiously.
[0008] In connection with audio/video input and output devices 106 - 2 , data displayed or audio played can include sensitive information which is subject to eavesdropping, particularly when computer 150 is being operated in a public place. However, when unauthorized copies of this displayed information are discovered, it is sometimes difficult to prove the source or circumstances of the unauthorized copy.
[0009] In connection with I/O ports and devices 106 - 3 , standard I/O communication protocols such as USB do not provide any level of security for the data transmitted from the peripheral devices to the host system. USB data is sent in plain text. Accordingly, the data can be captured and analyzed by any USB protocol analyzer or software application. Moreover, any USB peripheral is capable of connecting to a host computer since USB specification doesn't provide any means to filter unwanted or potentially harmful devices. This poses a huge risk for enterprises, and more particularly, IT administrators who are responsible for securing their IT systems and devices. Still further, USB devices may contain executable programs that can run on (and potentially harm) the computer 150 .
[0010] In connection with network interfaces 106 - 4 , data sent over a network can include sensitive information that is also subject to interception. Moreover, network data received by computer 150 can include harmful applications such as viruses and malware. Some organizations provide some level of security over their internal networks using such security protocols as VPN. However, not all network connections by computers in an organization utilize a VPN security protocol. And even when they do, they are not always automatically started prior to boot/network connection, providing a window of opportunity for the resident malware to send/receive information. Moreover, VPN connections in software are fairly slow and they do not support high-bandwidth connections, such as those in the hundreds of megabits/sec (e.g. 100 Mbs or 1 Gbs Ethernet and higher). In principle, all network communications using an organization's computers (whether internal or external) should be secured.
[0011] It should be apparent from the foregoing that many applications would benefit from the ability to seamlessly and unobtrusively add security over the above and other subsystems and/or from the ability to centrally manage such additional security features over the computer devices of an organization.
SUMMARY OF THE INVENTION
[0012] The present invention relates to a system and architecture for securing otherwise unsecured computer subsystems and IO interfaces that addresses the above shortcomings among others. According to one aspect, the invention provides an independent hardware platform for running software in a secure manner. According to another aspect, the invention provides the means to control and secure all disk, network and other I/O transactions. According to still further aspects, the invention provides a means to monitor and prevent unauthorized user and malicious software activity Additional aspects include providing a secure platform for device and user authentication as well as encryption key management, providing a means to perform background backup snapshots, and providing the means for enabling full management over computer operations.
[0013] In accordance with these and other aspects, a secure computer according to embodiments of the invention includes a plurality of subsystems for receiving, storing, retrieving from storage and outputting data, a host system running an operating system and applications that receive, store, retrieve and output the data, and a secure subsystem that controls access by the host systems to the plurality of subsystems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures, wherein:
[0015] FIG. 1A is a block diagram illustrating an example non-secure computer system according to the prior art;
[0016] FIG. 1B is a block diagram illustrating an example secure computer system according to embodiments of the invention;
[0017] FIG. 2 is a block diagram illustrating an example system for managing a plurality of secure computer devices according to embodiments of the invention; and
[0018] FIG. 3 is a more detailed block diagram illustrating an example architecture for a secure computer system according to embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The present invention will now be described in detail with reference to the drawings, which are provided as illustrative examples of the invention so as to enable those skilled in the art to practice the invention. Notably, the figures and examples below are not meant to limit the scope of the present invention to a single embodiment, but other embodiments are possible by way of interchange of some or all of the described or illustrated elements. Moreover, where certain elements of the present invention can be partially or fully implemented using known components, only those portions of such known components that are necessary for an understanding of the present invention will be described, and detailed descriptions of other portions of such known components will be omitted so as not to obscure the invention. Embodiments described as being implemented in software should not be limited thereto, but can include embodiments implemented in hardware, or combinations of software and hardware, and vice-versa, as will be apparent to those skilled in the art, unless otherwise specified herein. In the present specification, an embodiment showing a singular component should not be considered limiting; rather, the invention is intended to encompass other embodiments including a plurality of the same component, and vice-versa, unless explicitly stated otherwise herein. Moreover, applicants do not intend for any term in the specification or claims to be ascribed an uncommon or special meaning unless explicitly set forth as such. Further, the present invention encompasses present and future known equivalents to the known components referred to herein by way of illustration.
[0020] According to general aspects, embodiments of the invention include a secure computer platform creating a robust area of trust, secure processing, secure I/O and security management. In embodiments, the secure computer architecture includes a secure subsystem that operates independently alongside a host processor, eliminating the need to modify the host CPU hardware or software (e.g. operating system and/or applications). The secure subsystem is responsible for all security, management, data integrity, activity monitoring, archival and collaboration aspects of the secure computer. According to certain additional aspects, the security functions performed by embodiments of the invention can be logically transparent to both the upstream host and to the downstream device(s).
[0021] FIG. 1B illustrates an example secure computer 120 according to embodiments of the invention.
[0022] As can be seen in comparison to the prior art computer 150 in FIG. 1A , and in accordance with certain aspects of the invention, secure computer 120 includes secure subsystem 104 . In general, secure subsystem 104 operates alongside of and is agnostic of the host 102 (i.e. its hardware, software and operating system). For example, it does not share memory space with the host 102 nor is it accessible from the host CPU's operating system and applications. Similarly, the host 102 has little or no knowledge of the existence of the secure subsystem 104 . All data visible to the host 102 is secure, and all data stored on disk 106 - 1 or on other devices connected through ports 106 - 3 (e.g. USB mass storage device) or sent over the network 106 - 4 is secure. According to further aspects, the performance of subsystems associated with devices 106 is not reduced by the actions of secure subsystem 104 .
[0023] Certain other aspects of secure computer 120 contrast with those of prior art computer 150 . In a desktop PC implementation, for example, conventional computer 150 typically includes open interfaces (not shown), such as a PCI or PCIe expansion bus, by which host 102 connects to and communicates with devices 106 . The present inventors recognize, however, that this presents a potential security breach, such as where a probe could be inserted to extract/insert data/viruses, etc. In embodiments, therefore, the host 102 of secure computer 120 communicates with devices 106 only through secure subsystem 104 via secure connection 170 and is not connected to any expansion bus such as PCI or PCIe.
[0024] Secure connection 170 can be implemented in various ways, depending perhaps on the implementation of host system 102 and secure subsystem 104 . In one example where host system 102 includes a CPU on a separate chip as secure subsystem 104 but on a common motherboard, secure connection 170 can be implemented by embedded motherboard traces. In another example, host system 102 and secure subsystem 104 are implemented in a common chip such as a SOC. In this example, secure connection 170 includes internal chip traces.
[0025] Similarly, and in further contrast to conventional computer 150 according to aspects of the invention, connections 172 between secure subsystem 104 and devices 106 are also secured. However, it may not always be physically possible to make connections 172 completely inaccessible to the outside world. Accordingly, in embodiments these connections 172 are made secure by encrypting data between subsystem 104 and devices 106 . It should be noted that certain connections 172 in embodiments of the invention can include a conventional bus such as a dedicated PCIe bus. However, host 102 has no direct access whatsoever to devices 106 connected to these connections 172 , and vice-versa, except via subsystem 104 .
[0026] In accordance with aspects of the invention, embodiments of secure subsystem 104 transparently perform one or more of the following security functions in connection with drive 106 - 1 : data security (e.g. encryption of data stored on drive 106 - 1 , key management, anti-virus scanning); and data integrity (e.g. server-based backup using a snapshot mechanism);
[0027] In connection with ports/devices 106 - 3 , embodiments of secure subsystem 104 transparently perform one or more of the following security functions: data security (e.g. encryption of data sent from host 102 , key management); gatekeeping (e.g. preventing a prohibited device from connecting to host 102 ); data snooping; and keyboard and mouse emulation (e.g. emulating keyboard and mouse commands by subsystem 104 separately from commands from actual keyboards and mice devices 106 - 3 ).
[0028] In connection with network interface 106 - 4 , embodiments of secure subsystem 104 transparently perform one or more of the following security functions: VPN (e.g secure tunnel over Ethernet connection intended to protect all network traffic); and three-way switch (e.g. to direct incoming network traffic to one of the two hosts 102 or 104 ).
[0029] In connection with audio/video devices 106 - 2 , embodiments of secure subsystem 104 transparently perform one or more of the following security functions: video overlay of the video streams from the host system 102 and secure subsystem 104 ; video watermarking; display privacy; screen analytics, such as OCR; remote screen viewing; mixing audio inputs from the host system 102 and secure subsystem 104 ; audio watermarking; and forwarding of audio to a remote management system.
[0030] Secure computer 120 may be implemented as a desktop PC, notebook, thin client, tablet computer, smart phone, server, or any other type of computing device (e.g. TelePresence Unit, ATM machine, Industrial Controls, etc.).
[0031] It should be noted that, in embodiments such as that shown in FIG. 1 , the secure subsystem 104 controls access to all interfaces and peripheral devices 106 of computer 120 . However, this is not necessary, and other embodiments allow for certain of these devices 106 to be accessed directly by host 102 in the conventional manner. It should be further noted that the particular number and/or combination of devices and interfaces 106 can also depend on the particular implementation of secure computer 120 .
[0032] In one possible implementation, secure subsystem 104 is a standalone subsystem, and is not configurable. However, according to certain management aspects of the invention, in embodiments, secure subsystem 104 is configurable and one or more secure computers are managed either centrally or remotely by a remote management system.
[0033] FIG. 2 shows an example of system for implementing and managing secure computers according to embodiments of the invention.
[0034] In this example, there are three types of secure computers: a PC 220 - 3 , a notebook computer 220 - 2 , and a point-of-sale device 220 - 1 , each connected to a remote management system 206 by a respective communication channel 208 . Although not shown separately, a secure subsystem 104 is embedded into each of the appliances 220 and operates transparently to the normal functioning of the device.
[0035] In this example, secure PC 220 - 3 is similar to a conventional standalone desktop computer. In such an example, host 102 is implemented by a CPU (e.g. x86), a conventional operating system such as Windows and associated device driver software.
[0036] Likewise, in this example, secure notebook computer 220 - 2 is similar to a conventional standalone notebook computer. In such an example, host 102 is implemented by a CPU (e.g. x86), a conventional operating system such as Windows and associated device driver software. Unlike PC 220 - 3 , however, peripherals such as displays, keyboards and mice are integrated within the computer 220 - 2 and are not controlled via external interfaces such as HDMI and USB.
[0037] In secure point-of-sale device 220 - 1 , host 102 can be implemented by an embedded and/or industrial PC.
[0038] In these and other examples of secure computers 220 , subsystem 104 is preferably an embedded system. As such, it runs a designated software system furnished together with an embedded processor, and cannot be modified by the end-user of the computer under any circumstances. Various aspects of the types of security functionality performed by secure subsystem 104 that can be adapted for use in the present invention are described in more detail below. Those skilled in the art will be able to understand how to implement the security functionality of the invention using software and embedded processors after being taught by the present examples.
[0039] FIG. 2 further shows a Remote Management system 206 coupled to secure computers 220 by respective communication channels 208 . Channels 208 can be implemented in various ways, possibly depending on the number and type of devices to be managed by system 206 . Channels 208 can be separate direct point-to-point links between system 206 and computers 220 . In other embodiments, channels 208 can be implemented by a transmission medium that is shared between many computers 220 . In these and other embodiments, the medium can be any combination of wired or wireless media, such as Ethernet or Wireless LAN. In these and other embodiments, channels 208 can be implemented by various types and/or combinations of public and private networks using proprietary protocols running on top of conventional protocols such as UDP or TCP. In some embodiments, data sent over three communication channels described above is encrypted to improve security, for example using a secure VPN connection.
[0040] According to general aspects, in embodiments of the invention, remote management system 206 is responsible for managing policies that control the secure subsystem's security functionality, including whether or not to perform data encryption, whether and how to perform data snooping, device gatekeeping lists, etc. Based on these lists, and devices attached to interfaces of computers 220 , remote management system 206 sends appropriate configuration information to computers 220 via channels 208 . System 206 also receives and perhaps further processes data sent to system 206 from devices 220 such as video data from a computer's monitor, history of attached devices, keyboard and mouse input data, and disk backup data.
[0041] Various aspects of a remote management system and/or security policies that can be adapted for use in the present invention are described in more detail in U.S. Pat. No. 9,215,250, the contents of which are incorporated herein by reference in their entirety.
[0042] FIG. 3 is a block diagram of an example secure computer 320 according to embodiments of the invention.
[0043] As shown, secure computer 320 includes a host system 302 and a secure subsystem 304 . Host system 302 includes its own CPU (e.g. x86, ARM-based apps processor, server CPU, MIPS, QorIQ or PowerPC), memory & I/O sub-system. In embodiments, host system 302 has no direct access to the secure subsystem 304 . According to transparency aspects of the invention, the interface between host system 302 and secure processor 304 is implemented using host system 302 ′s standard interfaces with devices 106 , such as standard I/O, networking and storage interface. In some embodiments, there may be a control interface between the secure subsystem 304 and host system 302 with a predefined communications protocol over a dedicated hardware interface (e.g. UART) or a hardware-based handshake only (e.g. GPIO).
[0044] Secure subsystem 304 controls the overall operation of secure computer 320 , including access by host system 302 to all peripherals. Importantly, according to aspects of the invention, host system 302 is unable to directly exchange data with some or all of the computer system peripherals such as USB and other I/O devices, network interfaces, storage devices and audio/video devices except via secure subsystem 304 . In embodiments, secure subsystem 304 further controls all power management functions such as power on sequence, power down sequence, and entering and exiting low-power modes. Further, the secure processor 362 in secure subsystem 304 is booted first, and it goes to sleep or powers-down last. All aspects of BIOS authentication and update are managed by the secure subsystem 304 . Certain aspects of a computer having a host system 302 and whose overall operation is managed by secure subsystem 304 are described in U.S. Pat. No. 8,813,218, and can be adapted for use in the present invention.
[0045] In an example embodiment where computer 320 is similar to a conventional desktop PC, computer 320 includes a motherboard, host CPU, system bus, and memory. Differently from a conventional desktop PC, however, computer 320 does not include an expansion bus such as PCI or PCIe accessible to the host CPU. In one such embodiment, subsystem 304 is implemented by an ASIC or FPGA that is separate from the host CPU and data is sent between host system 302 and secure subsystem 304 over secure, embedded traces on the motherboard. In other embodiments, including where computer 320 is a tablet or mobile device (e.g. smartphone), or in other implementations where power, area and/or cost constraints are factors, both host system 302 and secure subsystem 304 are implemented in the same SOC.
[0046] Another possible embodiment includes providing secure subsystem 304 on a PCIe card in a conventional computer's PCIe expansion bus. Differently from the conventional computer PCIe expansion bus, however, this embodiment includes a “secure” PCIe connector that would prevent someone from inserting a “probe” between the connector and the card in order to trace the non-encrypted data between the host system 302 and secure subsystem 304 . This secure connector is preferably secure and destructive. The PCIe card could be inserted into a standard motherboard at manufacture time and it wouldn't be able to be removed thereafter. If someone tried to thereafter extract the PCIe card, the connector would “break” and the card wouldn't be able to be inserted again (and function properly). This may be achieved mechanically or even through the use of smart sensors that would detect an “abnormal” insertion of the PCIe card (i.e. the existence of a snooping device, like a simple PCIe extender card).
[0047] Secure processor 362 in subsystem 304 is typically implemented as an embedded processor, such as ARM or other embedded processor core. The processor is connected to memory and other system components, including subsystems 352 - 360 via a shared bus, such as AXI. In embodiments, components that require high-speed data transfer are connected via dedicated point-to-point DMA channels.
[0048] Although not shown in detail in FIG. 3 , embodiments of secure processor 362 include: a CPU (e.g. a single or many core CPU complex); local DDR memory and caches; non-volatile storage (e.g. flash memory); peripherals (e.g. 12C, SPI, UART, GPIO, and others); and media engines (e.g. 2D/3D graphics, audio/video compression). In general, secure processor 362 performs two primary tasks: to configure and manage all the sub-systems, and to run secure software stacks, applications, etc
[0049] As shown in the example of FIG. 3 , computer 320 also includes peripherals (keyboard, mouse, camera, mic, speakers, etc.), peripheral interfaces (USB, etc.), video (i.e. display), networking (e.g. Ethernet), SATA devices (e.g. storage HDD/SSD).
[0050] As further shown, and as described in more detail below, each of these peripherals has a corresponding subsystem 352 - 360 in secure subsystem 304 that essentially implements a secure I/O environment. They provide a secure bridge between host system 302 and the actual devices and implement security tasks such as data encryption/decryption, gate-keeping and snooping. According to aspects of the invention, each subsystem 352 - 360 performs these functions transparently to the host system 302 , in real-time, with minimal delay and in hardware (fast path).
[0051] In addition to managing the security tasks performed by subsystems 352 - 360 , secure processor 362 performs such tasks as exception handling, analyzing data captured by subsystems 352 - 360 , accumulating traffic statistics, etc. Secure processor 362 also includes a network interface for communicating with remote management system 206 via communication channel 308 . Such communications can include receiving policies for the security functions performed by subsystems 352 - 360 from management system 206 , sending data captured by subsystems 352 - 360 to management system 206 , and sending alerts of certain violations or threats detected by subsystems 352 - 360 to management system 206 .
[0052] In embodiments, the secure processor 362 receives logged/snooped information from the various subsystems and runs an application to store and analyze it for potential threat behavior. This can include correlating data from the various sub-systems of the secure computer as well as cross-correlating data between different secure computers. If a threat is detected, then an alarm is sent to remote system 206 , which will in return modify a policy and apply it to the suspicious secure computer. This may limit or shut down a certain interface, or lockout a certain user or shut down the entire computer, etc.
[0053] In embodiments, USB subsystem 352 is responsible for one or more tasks associated with attached USB devices such as data security (e.g. encryption, key management), gatekeeping, data snooping, and keyboard and mouse emulation. Example aspects of these and other security tasks that can be adapted for use in the present invention are described in more detail in co-pending applications U.S. patent application Ser. Nos. 13/971,582 and 13/971,604, and U.S. Pat. No. 9,076,003, for example.
[0054] In embodiments, networking subsystem 354 is one or more tasks associated with Ethernet, WiFi, and 3G devices such as secure protocols for secure, high-bandwidth connections (e.g. IPSec, SSL/TLS) and network processing, including classification and flow control engines.
[0055] In embodiments, storage subsystem 356 is responsible for one or more tasks associated with internal or external storage devices (e.g. SATA devices) such as data security (encryption, key management, anti-virus scanning), data integrity (e.g. server-based backup using snapshot mechanism) and data compression. Example aspects of these and other security tasks that can be adapted for use in the present invention are described in more detail in co-pending applications U.S. patent application Ser. Nos. 13/971,732 and 13/971,651.
[0056] In embodiments, audio subsystem 358 and video/graphics subsystem 360 are responsible for one or more tasks associated with audio/video devices such as displays, speakers, microphones and cameras such as multi-layer video resize, alpha-blending, audio mixing, audio and video watermarking (visible and invisible), 2D/3D graphics acceleration, compression, secure remote desktop, video conferencing, video surveillance, and desktop and video analytics applications. Example aspects of these and other security tasks that can be adapted for use in the present invention are described in more detail in U.S. Pat. No. 9,232,176.
[0057] In embodiments, every aspect of how secure subsystem 304 manages the operation of computer 320 is controlled by the remote management system 206 either dynamically or according to predefined policies stored and/or sent to the secure subsystem 304 . In embodiments, I/O interfaces are remotely controlled, monitored and backed up by the remote management system 201 , and may be limited or shut down completely if needed.
[0058] In embodiments where data written/read to/from storage and I/O devices as well as network traffic is encrypted/decrypted, the encryption and authentication keys are managed by the remote management system 206 and may be cached locally on the secure subsystem 304 .
[0059] Although the present invention has been particularly described with reference to the preferred embodiments thereof, it should be readily apparent to those of ordinary skill in the art that changes and modifications in the form and details may be made without departing from the spirit and scope of the invention. It is intended that the appended claims encompass such changes and modifications.
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The present invention relates to a system and architecture for securing otherwise unsecured computer subsystems. According to one aspect, the invention provides an independent hardware platform for running software in a secure manner. According to another aspect, the invention provides the means to control and secure all disk, network and other I/O transactions. According to still further aspects, the invention provides a means to monitor and prevent unauthorized user and malicious software activity Additional aspects include providing a secure platform for device and user authentication as well as encryption key management, providing a means to perform background backup snapshots, and providing the means for enabling full management over computer operations.
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FIELD OF THE INVENTION
The invention relates to controlling the access to a networked control system such as a lighting control system or a home control system.
BACKGROUND OF THE INVENTION
Networked control systems are a ubiquitous trend in commercial, industrial and institutional business markets and also in consumer markets. Examples of networked control systems are building automation systems, e.g. for lighting, heating and ventilation or safety. A networked control system may consist of devices like light ballasts, switches, daylight or occupancy sensors, actuators or meters. A networked control system also comprises a home control system for controlling for example media devices, which are connected to a network in the home and may be accessed and controlled via for example a web interface by means of another device such as a computer or network remote controller. The devices are preferably connected wirelessly, i.e. via RF (radio frequency) modules.
An example of a networked control system is the Light Master Modular (LMM) product line of the Applicant. LMM allows controlling of lamps in one or multiple rooms. A special version of LMM is controllable over a TCP/IP network connection remotely. In order to enable a comfortable control, a room controller with its IP-address must be bound to user interface devices being in the same room. However, one problem is that the user interface device has to get notified, when ever the room controller gets a new IP address, e.g. by means of a DHCP service, or a name server has to translate the controller name into the correct IP address. Another problem is that the user interface device may be moved to a different room but still controls devices in the original room, because the user interface device is still bound to the room controller of the original room.
US2005/0190768A1 addresses these problems and suggests to transmit the network address assigned to a device located in a delimited space to another discovering device not via the common network of the devices in the space, but in a manner that substantially limits its reception to the delimited space, for example by using infrared (IR) signals. When the discovering device receives such a signal containing the address of the discoverable device in the delimited space, it can establish a communication via the common network with the discoverable device that transmitted the address. Thus, discovery is limited to discovering devices residing in the delimited space also containing the discoverable devices.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a system and a method, which implement a control mechanism for the access to a networked control system, such as the access to devices controlled by a room controller.
The object is solved by the subject matter of the independent claims. Further embodiments are shown by the dependent claims.
A basic idea of the invention is to control the access to devices of a networked control system such as a lighting system by transmitting access information for the devices within a delimited space over a transmission channel differing from the transmission channel(s) of the networked control system and in a manner that substantially limits the reception of the access information to the delimited space, so that a user control device may receive the access information essentially only in the delimited space and may thus control only the devices in the delimited space, when it is located in the delimited space. According to the invention, the access information comprises an access identifier for obtaining access for controlling one or more of the devices in the delimited space. According to an embodiment of the invention, the access information may further comprise user profiles of the devices, which inform a user of the functionality of devices and may implement user interfaces for the devices in a receiving user control device. In contrast to a kind of pairing mechanism for two devices to communicate as disclosed in US2005/0190768A1, the invention provides an access mechanism to a group of devices, namely devices in a delimited space such as room, which enables a user control device to access all devices in the delimited space by using the access identifier contained in the access information.
An embodiment of the invention provides a system for controlling the access to a networked control system, wherein
devices of the networked control system are connected to the same network and are assigned to the same delimited space, a transmitter device transmits access information for the devices within the delimited space over a transmission channel differing from the transmission channel(s) of the networked control system and in a manner that substantially limits the reception of the access information to the delimited space, wherein the access information comprises an access identifier for obtaining access for controlling one or more of the devices in the delimited space, and a receiver device receives the transmitted access information and controls a device assigned to the delimited space over the network by using the access identifier contained in the received access information.
The access information enables a receiver device in the delimited space to access all devices of the networked control system in the delimited space. The access identifier may be regarded as a kind login information, which allows the receiver device to get an access to all devices in the delimited space. It should be noted that the access information is not a simple network address of one of the devices in the delimited space, as it is known from US2005/0190768A1, but is information allowing a receiver device to access all devices in the delimited space. When a receiver device, for example a PDA of a user, is carried into another delimited space such as another room, the PDA may obtain the access information broadcasted in this room and obtain access to the devices located in this room. Devices as used herein comprise every device, which may be part of a networked control system and has a network connection, and may be accessed via a network. Devices may be for example lamps, light ballasts, switches, daylight or occupancy sensors, actuators or meters, media devices such as consumer electronic goods like networked MP3 players, sat receivers, media disk player, which allow control over an web user frontend.
The transmitter device may frequently change the access identifier contained in the transmitted access information. Thus, operation of the devices is essentially restricted to a receiver device located in the delimited space. In other words, when a receiver device is brought outside the delimited space, it may loose access to the devices located in the delimited space, when the access identifier is changed. This allows avoiding for example a situation, where a user changes a room and has still access to the devices of the room, where the user were previously located.
The transmitted access information may further comprise a network address of a central controller of the network, so that a direct communication with the central controller and a receiver device over the same network is enabled. For example, in case of a TCP/IP network, a receiver device may directly contact an embedded web server of a central controller and get access to special features of the central controller or an overview of the devices, which are controlled by the central controller.
The access information may further comprise user profiles of the devices and the receiver device may control a device assigned to the delimited space over the network by using the corresponding user profile and the access identifier contained in the received access information. By transmitting user profiles of devices, which are located in a delimited space, together with an access identifier, a comfortable access control to only the device within the delimited space may be achieved. The user profiles of devices, which may be contained in the access information, may for example instruct a receiver device to adapt a GUI (Graphical User Interface) on the receiver device for a comfortable control of the device, to which the user profile is assigned, such as showing the functionality of the device and allowing to use the functionality from the receiver device.
A user profile of a device may contain one or more of the following: user interface properties; controllable parameters of the corresponding devices; a pointer to a download location for a user interface properties and/or applets; device settings for special situations. User interface properties may be for example comprise text boxes and buttons of a user interface for a certain device. The controllable parameters may for example comprise lighting intensity, color, saturation in case of a lamp as controllable device, or the temperature in case of an HVAC (Heating, Ventilation, Air Conditioning) controller, or selectable pictures in case of a digital picture frame or TV set, or a selection of display information in case of an electronic display, or typical printer parameters in case of a printer station.
One device may act as a proxy device for the other devices, and the access information comprises only the user profile of the proxy device. The one device may be for example a central controller, which is configured to control all devices connected to the central controller, for example a central lighting control module such as the before mentioned LCM of the Applicant. Thus, only one user interface must be transmitted and displayed on a receiver device, which may make the control of the devices connected to the proxy device easier and more comfortable for a user. Also, devices located in other delimited spaces or devices shared with multiple delimited spaces such as a HVAC devices shared with multiple rooms in building may be controlled via the proxy devices.
The devices may be selected from the group comprising lamps, window shutters, HVAC controllers, electronic displays, printer stations, beamer, teleconference devices, roll down projection walls. This group essentially comprises devices, which may be typically located in an office environment, such as a conference or meeting room. However, also some of the device may be also found in an home environment, such as lamps and window shutters, thus qualifying the invention also for home use.
The transmitter device may transmit the access information via optical and/or RF means, wherein the range of transmission is essentially constrained to the delimited space. Optical means may for example comprise Infrared (IR) transmitter, or lamps, which generate modulated light in order to transmit the access information. The RF (Radio Frequency) means may typically comprise Near Field Communication (NFC), ZigBee™ or Bluetooth™ technology. These technologies typically operate with low power and, thus, merely have a restricted range of receipt. Especially, these technologies may be operated adapted to the delimited space so that access information can essentially be received in the delimited space, but not in neighbored spaces. There may be however also interesting situations where overlapping space can be detected e.g. an area between two workplaces and the control may neither work for one or the other or depending on a preprogrammed policy for both.
A further embodiment of the invention relates to a transmitter device being adapted for application with a system of the invention and as described before and comprising the transmitter device. The transmitter device comprises an interface to a device of the network, which may be configured as central controller of the network, wherein the interface is adapted to receive access information for the devices controlled by the central controller and assigned to a delimited space. The transmitter device may be for example implemented as a IR or RF transmitter with a serial interface, which allows a connection with the central controller, and the controller may control the transmitter device over the interface to transmit access information. Also, the transmitter device may comprise a logic which may generate the access information based on information received from the central controller.
The invention relates in another embodiment to a receiver device being adapted for application with a system of the invention and as described before. The receiver device is configured to process access information received within a delimited space and to control a device assigned to the delimited space by using the access identifier contained in the received access information. Particularly, the receiver device may be configured to control a device assigned to the delimited space by using a user profile of the device, which is contained in the received access information. For example, the receiver device may be a kind of remote control with a display for displaying a Graphical User Interface with a received user profile, allowing a user to comfortably access devices in the delimited space. The receiver device may for example be implemented by a PDA, which executes software, which configures an IR or RF interface of the PDA to receive the access information, to process the received information and to enable a user by means of a GUI to comfortably operate and control devices in the delimited space. In order to accomplish this, the PDA may establish a connection to the networked control system over for example a mobile data connection such as a wireless network connection such as a mobile radio communication data connection. Also, the receiver device may be implemented by a PC and an IR or RF detector device, which contains all necessary software (or a boot loader for the software) to allow the PC to act as user interface for the room infrastructure.
A further embodiment of the invention relates to a method for controlling the access to a networked control system, wherein devices of the networked control system are connected to the same network and are assigned to the same delimited space and the method comprises the acts of
transmitting access information for the devices within the delimited space over a transmission channel differing from the transmission channel(s) of the networked control system and in a manner that substantially limits the reception of the access information to the delimited space, wherein the access information comprises an access identifier for obtaining access for controlling one or more of the devices in the delimited space, and receiving the transmitted access information and controlling a device assigned to the delimited space over the network by using the access identifier contained in the received access information.
The method may comprise one or more of the following:
frequently changing the access identifier contained in the transmitted access information; transmitting with the access information a network address of a central controller of the network; the access information may further comprise user profiles of the devices and controlling a device assigned to the delimited space over the network by using the corresponding user profile and the access information; integrating in a user profile of a device one or more of the following: user interface properties; controllable parameters of the corresponding devices; a pointer to a download location for a user interface properties and/or applets; device settings for special situations, such as for example limit values for an allowed setting may be transferred or a preferred setting that adjusts to a nice all day setting with one button action; selecting one device, which acts as a proxy device for the other devices, and integrating in the access information only the user profile of the proxy device; selecting the devices from the group comprising lamps, window shutters, HVAC controllers, electronic displays, printer stations, beamer, teleconference devices, roll down projection walls; transmitting the access information via optical and/or RF means, wherein the range of transmission is restricted in that the reception of the access information is essentially limited to the delimited space.
According to a further embodiment of the invention, a record carrier storing a computer program according to the invention may be provided, for example a CD-ROM, a DVD, a memory card, a diskette, internet memory device or a similar data carrier suitable to store the computer program for optical or electronic access.
A further embodiment of the invention provides a computer programmed to perform a method according to the invention such as a PC (Personal Computer).
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
The invention will be described in more detail hereinafter with reference to exemplary embodiments. However, the invention is not limited to these exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an overview of a lighting system installation as an example of a networked control system with an access control according to the invention;
FIG. 2 shows a block diagram of an embodiment of a system for controlling the access to a networked lighting system according to the invention;
FIG. 3 shows an embodiment of a central controller of a system for controlling the access to a networked lighting system according to the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
In the following, functionally similar or identical elements may have the same reference numerals.
The embodiments of this invention, which are described in the following, relate to a method to distribute access information for a user interface device or PC application by means of IR light through out a room as delimited space. This is achieved by adding an IR sender LED to a central light controller, as will be described in detail. The controller can select information to be broadcasted into the room that user interface devices can decode from IR and use to access functions for that room. Changing access codes will guarantee that if the user interface device gets moved out of the room will soon lose the access rights and can not erroneously operate devices in the old room. More over it will automatically learn available features of the area it is placed and will allow to control the light there. This is an enabling feature to allow mobile phones, palms or ultra portable-PCs and PCs to control room infrastructure via a wireless LAN (Local Area Network) or internet because users will only be granted access if they are in optical contact to the room controlled. This opens up also access to shutters, air condition, presentation or media playback means that are available for a room.
FIG. 1 shows an overview of two neighbored rooms 16 and 18 . Both rooms are equipped with a networked control system 10 , which comprises several lamps 121 , an electronic display 122 installed near the entry to the room 16 or 18 , respectively, a window shutter 124 , and a central controller 32 and 34 , respectively, to which the devices 121 , 122 and 124 are connected via control connections 15 . In room 18 also a printer station 123 is located, which is connected to the central controller 34 of this room. A central controller may be implemented based on the LCM of the Applicant, but with additional features such as a TCP/IP network connection and an interface for a transmitter device 20 / 22 (as will be explained later).
Each controller 32 and 34 is part of a networked control system of the building housing the two rooms 16 and 18 . The controller 32 and 34 are connected to a TCP-IP network 14 , which may enable an access for example to a WAN (Wide Area Network) such as the Internet 38 by means of a router 36 . The central controller 32 and 34 may also be accessed from a remote location via the Internet 38 and the router 36 . The router 36 comprises also a DHCP (Dynamic Host Configuration Protocol) server, which automatically assigns IP addresses to the controller 32 and 34 and to each device, which is connected to the TCP/IP network 14 and does not have a fixed IP address.
Each controller 32 and 34 is connected to an IR transmitter device 20 or 22 , respectively, which is controlled by the connected controller 32 or 34 , respectively, and frequently transmits in broadcast manner access information within the room 16 or 18 , respectively. The receiving range 28 and 30 , respectively, of the broadcasted access information is shown by a dotted circle around the IR transmitter device 20 and 22 , respectively. Thus, the broadcasted access information can only be received in the respective room, and not in any neighbored room. It is clear that even without the wall between rooms 16 and 18 the non overlapping feature of ranges 28 and 30 would allow to control the two different lamp installations dependant on the position of the controller. This might be the important application in open plan office spaces or cube farms. Instead of using an IR transmitter device, also one or more of the lamps 121 can be controlled by the respective controller 32 or 34 to modulate their light flux with the access information. Thus, no extra transmitter device for the access information broadcasting is required. Alternatively or additionally, RF technologies can be applied to transmit access information. The applied RF technologies should be selected and operated such that the range 28 and 30 , respectively, corresponds essentially to the respective room 16 and 18 . Typically and suitable known RF technologies are the already before mentioned ZigBee™ and Bluetooth™ technologies. These RF technologies allow restricting the range of receipt to some meters, which may be sufficient to cover the area of a standard conference or meeting room. For larger facilities, several transmitter devices may be applied to cover the entire are of a facility.
Access to the devices 121 - 124 , or to control of the devices 121 - 124 in each of the rooms 16 and 18 may be achieved by means of a receiver device 26 , for example a PDA or a PC of a user. The receiver device 26 is adapted to receive the broadcasted access information within a room, for example comprises an IR receiver or a RF module. Also, the receiver device 26 may establish a network connection 14 for example a wireless network connection with the router 36 in order to access the Internet 38 and the central controller 32 . Furthermore, the receiver device 26 is configured to process the received access information. The access information comprises user profiles of the devices 121 - 124 and a room identifier as an access identifier to the devices. The following table shows an example of typical access information for lamps in a room:
Room ID 01234567
device ID 01 user profile (lamp)
device ID 02 user profile (electronic display)
device ID 03 user profile (window shutter)
. . .
Each user profile comprises user interface properties; controllable parameters of the corresponding devices; a pointer to a download location for a user interface properties and/or applets; device settings for special situations. An example of a typical user profile “device ID XY user profile” of a lamp is shown in the following table:
UI Property “ON/OFF”
UI Property “Color”
UI Property “Brightness”
UI Property “Saturation”
http://www.xyz.com/UI/applets/UI_properties
Setting “Presentation”
Setting “Meeting”
Setting “Videoconference”
. . .
The receiver device 26 processes the received access information by means of a dedicated software executed by the receiver device, for example an networked control system access program, which may be for example executed by a PDA or PC. Each user profile contained in the received access information is processed in that a GUI on the receiver device 26 is configured in accordance with the received user profiles. Thus, a GUI is displayed with controls for each device 121 - 124 in the room for controlling each device, for example in case of a lamp for switching the lamp on or off, adjusting the color, brightness and saturation of the lighting created by the lamp. Also, an applet may be downloaded from the Internet 38 under the exemplary address http://www.xyz.com/UI/applets/UI_properties which implements the GUI for the respective device. The location of downloadable applets must not necessarily be the Internet, also an HTML frontend integrated in the controller 32 or 34 , respectively, itself might get accessed in the same way by issuing a local IP address or by issuing a device name that can be localized by a dynamic name server. So the device ID XY user profile may also contain a pointer into a local area network space. Particularly, the applet may implement further functionality which is not achievable only with the program on the PDA or PC. For example, the GUI may display buttons “Presentation”, “Meeting” and “Videoconference” for setting a lamp for the respective situation. When a user selects the button “Presentation” on the PDA, a command is transmitted from the PDA to the central controller 32 in the room 16 to set the lamps 121 to create a lighting suitable for doing presentations with a beamer in the room 16 , such as a dimmed lighting and instructing the window shutter 124 to close the window. Also, the central controller 32 may roll down a projection screen. The command transmitted from the PDA contains the room identifier in order to assure that only devices in the room 16 are controlled, and no devices of the neighbored room 18 .
A block diagram of central controller for a lighting system is shown in FIG. 2 . The central controller 32 controls a number of lamps 121 connected to the controller 20 . Different sensors 13 may be connected to monitor the room, for example motion or presence detection and/or light flux sensors. Another example of a sensor is an air quality sensor, which may be able to set a warn signal on the remote receiver device 26 when CO2 concentration gets to high for a meeting situation. So sensors may not only be used that have direct control towards the lighting system but get used by human operators. Also user operated switches 17 may be connected. The controller 32 is remotely accessible over an addressable network connection like a TCP/IP wired or wireless network 14 . The controller 32 is in addition connected to several IR transmitters 20 . Especially, for a large room multiple IR transmitter 20 may be necessary to flood the whole room. The controller 20 has an access identifier that is stored in an internal memory 33 . The access identifier may also correspond to the room identifier as mentioned above with regard to FIG. 1 . During active time the controller 32 may constantly or from time to time broadcast access information containing the access identifier from the internal memory 33 and user profiles for the lamps and the controller itself via the IR transmitter 20 to a UI (User Interface) receiver device 26 that is equipped with an IR sensor 27 for receiving the IR signals sent out by the IR transmitter 20 . The access information may also comprise the controller's address, for example IP address or the node name, and also other information supporting the light control which may be broadcasted into the room e.g.: what parameters are available, how the UI should look like etc.
In a further improved embodiment of the central controller a frequently, particularly constantly changing access identifier or code may be broadcasted so that only UI devices receiving it in the room may access devices in the room. Stolen UI devices will not work any more. Or UI devices that get moved to another room with the same kind of light controller installed will automatically take over the role of a user interface for the new room.
Optically broadcasted information may also pinpoint to an internet location or a local server or storage place where an appropriate user interface applet can be loaded enabling PCs or other programmable appliances to get appropriate UI visualization and controls, refer to the table above showing a typical user profile broadcasted with the access information in a room.
In a further improved embodiment the central controller may also have memory that can be used to store access information as well as user interface control information for totally different features as installed in the room like beamers, TV-sets, teleconference means, roll down projection walls, window shutters or air condition or heating control. In this way a user of a meeting room having an IR detector integrated in his laptop or plugged in the USB of the laptop gets automatic notification of all available features and a user interface applet to control these. This would be the end of lost remote controls for meeting rooms.
It is clear that a networking of the aforementioned features makes sense in many cases anyway, e.g. adjust lights and window shutters automatically when the beamer gets activated and roll down the projection screen, or having special light settings for TV viewing or teleconferences.
It may be even beneficial to integrate the access to the other room features through the light controller which then proxies the different control commands towards the different devices. In this way the UI has only to communicate with a single entity. This may be very advisable if devices like air-conditioning or heating are shared with multiple rooms, since then one light controller can decide for the setting of such a room-shared device. Also intelligent spaces where presence detection gets used to control some of the room features would be straighter forward in the implementation.
One possible implementation of a central controller 32 is shown in FIG. 3 . The control box 32 is mounted in a hole in the ceiling and has directly mounted an IR broadcasting transmitter 20 in the cover. Other sensors like presence detectors 13 may also be integrated directly in the box 32 .
The invention can be applied in any networked control system such as a complex lighting system with a plurality of light sources, for example a lighting system installed in homes, shops and office applications. It is particularly suitable for the comfortable and easy control of functions by means of a user interface device.
At least some of the functionality of the invention may be performed by hard- or software. In case of an implementation in software, a single or multiple standard microprocessors or microcontrollers may be used to process a single or multiple algorithms implementing the invention.
It should be noted that the word “comprise” does not exclude other elements or steps, and that the word “a” or “an” does not exclude a plurality. Furthermore, any reference signs in the claims shall not be construed as limiting the scope of the invention.
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A system and method for controlling access to a networked control system, such as a lighting control system or a home control system, include devices connected to the same network and assigned to a particular delimited space, a transmitter device which transmits access information for the devices within the delimited space over a range restricted transmission channel differing from the transmission channel(s) of the networked control system which substantially limits the reception of the access information to the delimited space, wherein the access information includes an access identifier for obtaining access for controlling one or more of the devices in the delimited space, and a receiver device which receives the transmitted access information and controls a device assigned to the delimited space over the network by using the access identifier contained in the received access information.
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TECHNICAL FIELD
The present invention relates generally to equipment for applying a liquid to surfaces, and more particularly, to fluid level sensing for a spray applicator device.
BACKGROUND OF THE INVENTION
A wide variety of spray application devices for applying liquids such as paint, varnish, cleaning solvents, or other liquid materials to a surface are known. Typically, such spray applicator devices include a supply vessel that contains a volume of the liquid to be applied to the surface. The liquid is transferred from the supply vessel to a spray gun that atomizes the liquid and projects the atomized liquid towards the surface. In one example of a spray applicator device, the supply vessel is positioned above the spray gun so that the liquid is transferred to the spray gun by a gravity-feed system. In another example of an applicator device, the supply vessel may be positioned below the spray gun and internally pressurized to transfer the liquid upwardly into the gun. In still other examples, the vessel may be positioned remotely relative to the gun so that the liquid is transferred from the vessel to the spray gun through a flexible hose.
In all of these spray applicator devices, determining the volume of the liquid remaining in the supply vessel as the application of the liquid proceeds constitutes a significant problem. If the liquid volume in the supply vessel is reduced to a low value, the gun may be supplied with liquid only intermittently, so that the gun emits the atomized liquid on an interrupted basis. As a consequence, the spray applicator device fails to apply the liquid uniformly to the surface. In particular, when the spray applicator device is used to apply a paint material to a surface, surface imperfections in the paint finish may result when non-atomized paint is projected, or “sputtered” onto the surface, thus necessitating time consuming surface rework and re-painting. Since supply vessels commonly used with spray guns are comprised of materials that are substantially non-transparent, a visual indication of the liquid level in the supply vessel is not generally possible.
Accordingly, there is a need in the art for a level-sensing device for spray applicators to provide a user of the spray applicator with an audible or visual indication when the volume of liquid in the supply vessel has been reduced to a predetermined level.
SUMMARY OF THE INVENTION
The present invention relates generally to a spray applicator device for applying a liquid to surfaces, and more particularly, to a fluid level sensing apparatus and method for a spray applicator device. In one aspect, a spray applicator apparatus includes a gun configured to receive a liquid and atomize the liquid, and a supply vessel coupled to the gun. The supply vessel retains a volume of the liquid and includes a level sensor responsive to the volume retained by the supply vessel. In another aspect, a level-sensing supply vessel for a spray applicator includes a level sensor responsive to a volume of liquid retained by the supply vessel, the sensor including a sensor element configured to detect the volume by sensing a resistance property of the liquid. In still a further aspect, a method of sensing a level of a liquid retained within a storage vessel of a spray applicator includes sensing a first volume retained within the vessel, removing a portion of the first volume to define a second volume, determining if the second volume is less than a predetermined minimum volume, and generating an alarm signal if the second volume is less than the predetermined minimum volume.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial diagrammatic view of a spray applicator according to an embodiment of the invention.
FIG. 2 is a schematic view of a control system for a spray applicator having a level sensor according to an embodiment of the invention.
FIG. 3 is a is a schematic view of a control system for a spray applicator having a level sensor according to another embodiment of the invention.
FIG. 4 is a partial cross-sectional view of a supply vessel for a spray applicator having a level sensor according to another embodiment of the invention.
FIG. 5 is a partial cross-sectional view of a supply vessel for a spray applicator having a level sensor according to still another embodiment of the invention.
FIG. 6 is a partial cross-sectional view of a supply vessel for a spray applicator having a level sensor according to still yet another embodiment of the invention.
FIG. 7 is a cross sectional portion of a sensor element according to still yet another embodiment of the invention.
FIG. 8 is a partial cross-sectional view of a supply vessel for a spray applicator having a level sensor according to a further embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is generally directed to equipment for applying liquid coating materials to surfaces, and in particular, to fluid level sensing for a spray applicator. Many of the specific details of certain embodiments of the invention are set forth in the following description and in FIGS. 1–8 to provide a thorough understanding of such embodiments. One skilled in the art will understand, however, that the present invention may be practiced without several of the details described in the following description. Moreover, in the description that follows, it is understood that the figures related to the various embodiments are not to be interpreted as conveying any specific or relative physical dimension. Instead, it is understood that specific or relative dimensions related to the embodiments, if stated, are not to be considered limiting unless the claims expressly state otherwise.
FIG. 1 is a partial diagrammatic view of a spray applicator 10 according to an embodiment of the invention. The spray applicator 10 includes a supply vessel 12 that contains a volume of a liquid 14 . A spray gun 16 is coupled to the supply vessel 12 , and transfers the liquid 14 to the spray gun 16 so that an atomized spray pattern may be developed at a nozzle 18 . As the spray pattern is emitted from the gun 16 , the liquid 14 retained within the supply vessel 12 is gradually depleted, so that a surface level of the liquid 14 gradually descends as the spraying operation is conducted. Operational details of the spray gun 16 are well known in the art, and need not be discussed in further detail. Although a gravity-feed type spray applicator is shown in FIG. 1 , it is understood that the various embodiments of the present invention may also be employed in other types of spray applicators, and are therefore not limited to the spray gun shown in FIG. 1 . For example, the supply vessel 12 may be positioned below the spray gun 16 , or alternately may be located remotely from the spray gun 16 so that the liquid 14 is transferred to the spray gun 16 by a flexible hose, or other similar devices (not shown).
Still referring to FIG. 1 , the spray applicator 10 further includes a sensor element 20 that extends into the liquid 14 within the supply vessel 12 . The sensor element 20 is configured to allow an electrical resistance property of the liquid 14 to be measured that corresponds to a volume of liquid 14 retained within the vessel 12 . For example, when the volume of liquid 14 defines a first level 22 within the supply vessel 12 , a first resistance quantity may be measured by the sensor element 20 . As the volume of the liquid 14 is gradually reduced to define a relatively lower intermediate level 24 , a second resistance quantity that differs from the first resistance quantity may be read by the sensor element 20 . As the level of the volume of the liquid 14 is reduced still further to define a second level 26 , so that the sensor element 20 is no longer immersed in the liquid 14 , the sensor element 20 ceases to measure a resistance quantity related to the liquid 14 , so that only a resistance property related to the sensor element 20 is measurable. The sensor element 20 will be described in further detail below.
A control system 28 is operatively coupled to the sensor element 20 . The control system 28 includes circuitry that is configured to measure electrical resistance quantities sensed by the sensor element 20 , and to output a control signal when a predetermined resistance quantity is measured. Referring now to FIG. 2 , a particular embodiment for the control system 28 of FIG. 1 is shown. The control system 28 includes a voltage source 30 that is selectively coupled to a current-sensing network 32 by a switch 34 . The system 28 is coupled to the sensor element 20 , which has a resistance value (R L ) that depends upon the volume of the liquid 14 retained by the supply vessel 12 , as previously described. With the switch 34 closed, the system 28 is energized and current flows in the resistance R L . The current-sensing network 32 measures a current flowing in the control system 28 and generates an output signal 36 when a predetermined current level corresponding to a predetermined volume of the liquid 14 is reached. In order to adjustably control the current flowing in the system 28 , a potentiometer 38 may be serially coupled to the sensor element 20 . In an alternative particular embodiment, the potentiometer 38 may be coupled in parallel with the sensor element 20 .
Turning now to FIG. 3 , another particular embodiment for the control system 28 of FIG. 1 is shown. In this embodiment, the control system 28 includes a current source 40 that is selectively coupled to a voltage-sensing network 42 by the switch 34 . The system 28 is coupled to the sensor element 20 . With the switch 34 closed, the system 28 is energized and a constant current flows in the resistance R L . The voltage-sensing network 42 measures a voltage across the resistance R L and generates an output signal 36 when a predetermined voltage corresponding to a predetermined volume of the liquid 14 is reached. To adjustably control the voltage appearing across the resistance R L , a potentiometer 38 may be serially coupled to the sensor element 20 . In still another alternative particular embodiment, the potentiometer 38 may be coupled in parallel with the sensor element 20 .
Returning to FIG. 1 , the control system 28 is coupled to an alarm device 29 that is configured to emit an alarm indication when a suitable output signal 36 is received from the control system 28 . In one specific embodiment of the invention, the alarm device 29 may be a visual alarm device, such as an incandescent light bulb, light emitting diode (LED), or other similar devices that illuminate when the output signal 36 is received. In another specific embodiment, the alarm device may be an audible alarm device, such as a piezoelectric speaker device, or other similar device capable of emitting acoustic energy that may be perceived by an operator of the spray applicator 10 . The alarm device 29 may also include a source of electrical energy to energize the audible or visual alarm device, or alternately, the alarm device 29 may receive electrical energy from the electrical energy source located within the control system 28 .
The operation of the spray applicator 10 will now be described in detail. Still referring to FIG. 1 , the supply vessel 12 on the spray applicator 10 is supplied with an initial volume of the liquid 14 that defines the first level 22 . At this point, the sensor element 20 senses a first resistance quantity corresponding to the initial volume of the liquid 14 . Since the sensed first resistance quantity corresponds to a supply vessel 12 that contains a suitable amount of the liquid 14 , the control system 28 does not generate an output signal 36 (as shown in FIGS. 2 and 3 ) so that the alarm device 29 does not generate an audible or visual signal. As the liquid 14 is drawn from the supply vessel 12 , the volume of the liquid 14 decreases to the second level 26 , so that a different resistance quantity is sensed. Since the sensor 20 is no longer exposed to the liquid 14 , the output signal 36 is generated by the control system 28 in response to the different resistance quantity. Accordingly, the alarm device 29 generates the audible or visual alarm that alerts the operator of the spray applicator 10 that the liquid 14 in the supply vessel has been depleted. Although the foregoing describes the output signal 36 as generated when the supply vessel 12 is substantially depleted, it is understood that the control system 28 may be configured to generate the output signal 36 when the volume of liquid 14 has decreased to a value that is intermediate between a full and a depleted state. For example, and referring still to FIG. 1 , the control system 28 may be configured to generate the output signal 36 when the volume of liquid 14 falls to the intermediate level 24 .
FIG. 4 is a partial cross sectional view of the supply vessel 12 of FIG. 1 that shows a sensor element 50 according to another embodiment of the invention. The sensor element 50 includes a first electrode 52 and a second electrode 54 that is spaced apart from the first electrode 52 . The first electrode 52 and the second electrode 54 are comprised of an electrically conductive material, and are structured to extend through a wall of the supply vessel 12 and to extend downwardly into the liquid 14 within the supply vessel 12 . In order to electrically isolate the first electrode 52 and the second electrode 54 from the wall of the supply vessel 12 , insulators 56 are interposed between the first electrode 52 , the second electrode 54 and the wall of the supply vessel 12 . The first electrode 52 and the second electrode 54 may further include extended portions 58 to permit the sensor element 50 to be coupled to the control system 28 .
FIG. 5 is a partial cross sectional view of the supply vessel 12 of FIG. 1 that shows a sensor element 60 according to still another embodiment of the invention. As in the previous embodiment, the sensor element 60 includes a first electrode 62 and a second electrode 64 that is spaced apart from the first electrode 62 . The first electrode 62 and the second electrode 64 are similarly comprised of an electrically conductive material, and positioned adjacent to the wall of the supply vessel 12 and spaced apart from the wall by respective insulating layers 63 and 65 . The first electrode 62 and the second electrode 64 are electrically isolated from the wall of the supply vessel 12 by insulators 56 that extend through the wall of the supply vessel 12 . The first electrode 62 and the second electrode 64 also may include extended portions 58 to permit the sensor element 50 to be coupled to the control system 28 .
FIG. 6 is a partial cross sectional view of the supply vessel 12 of FIG. 1 that shows a sensor element 70 according to still yet another embodiment of the invention. The sensor element 70 includes a first electrode 72 and a second electrode 74 that are formed on an insulating substrate 76 that extends downwardly into the supply vessel 12 . Referring briefly to FIG. 7 , a cross sectional portion of the sensor element 70 is shown along the section line 7 — 7 of FIG. 6 . The first electrode 72 and the second electrode 74 may be formed from a relatively thin and electrically conductive foil that is cladded onto the insulating substrate 76 . The substrate 76 may be comprised of a generally rigid, nonconductive material such as a rigid polymer. The sensor element 70 is suspended within the liquid 14 by an insulating support means (not shown) that is coupled to the wall of the supply vessel 12 . As in the previous embodiments, the first electrode 72 and the second electrode 74 may be coupled to the control system 28 by extended portions 58 that project through the wall of the supply vessel 12 .
FIG. 8 is a partial cross sectional view of the supply vessel 12 of FIG. 1 that shows a sensor element 70 according to a further embodiment of the invention. The sensor element 70 includes an electrode 82 formed from an electrically conductive material, which extends downwardly into the supply vessel 12 and is spaced apart from the wall of the supply vessel 12 . Instead of an electrode that opposes electrode 82 , as in the previous embodiments, the wall of the supply vessel 12 forms an electrode opposite the first electrode 62 . The first electrode 82 is coupled to the control system 28 by an extended portion 58 that extends through the wall of the supply vessel 12 , and is electrically insulated from the wall by an insulator 56 . The supply vessel 12 is also coupled to the control system 28 by a lead 84 that is conductively coupled to the supply vessel 12 .
From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. For example, certain features shown in the context of one embodiment of the invention may be incorporated into other embodiments as well. Accordingly, the invention is not limited by the foregoing description of embodiments except as by the following claims.
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The present invention relates to a level sensing spray applicator. In one embodiment, the spray applicator includes a gun that receives a liquid and a supply vessel coupled to the gun. The vessel includes a level sensor responsive to the volume retained by the supply vessel. In another aspect, a level-sensing supply vessel includes a level sensor responsive to a volume of liquid retained by the supply vessel, the sensor including a sensor element to detect the volume by sensing a resistance property of the liquid. In still a further aspect, a method of sensing a level of a liquid retained within a storage vessel includes sensing a first liquid volume, removing a portion of the first volume to define a second volume, determining if the second volume is less than a minimum volume, and generating an alarm signal if the second volume is less than the minimum volume.
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SUMMARY OF THE INVENTION
This invention relates to an improved construction of a pumping unit for circulating either fluids or gases.
One of the objects of this invention is to provide a hydraulic fluid device with a vertical channel of varying cross sectional area which contains a fluid or gas to be pumped by a second fluid which rises and falls in this channel.
Another object of this invention is to provide a pumping device for fluids or gases comprising a sealed container adapted to hold a dense fluid, a vertical plunger entering the container and a vertical channel within the plunger which is open at the bottom and valved at the top.
Another object of this invention is to provide a pumping device for fluids or gases comprising a sealed container adapted to hold a dense fluid, a vertical plunger entering the container and a vertical channel within the plunger open at the bottom and valved at the top, the vertical channel containing flexible membranes which form distinct free interior volumes or chambers, that completely contain the fluids or gases within them.
Another object of this invention is to provide a hydraulic fluid device for circulating either fluids or gases under variable pressure to volume ratios that may be predetermined or altered as desired with a given force operating the device during the course of a single pumping stroke.
Additional objects, advantages and features of invention reside in the construction, arrangement and combination of parts involved in the embodiment of the invention and its practice as will be understood from the following description and accompanying drawings wherein
FIG. I is a vertical sectional view through the pumping unit.
FIG. II is a top plan view thereof.
FIG. III is a vertical sectional view of the outer sleeve of the pump plunger.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings which illustrate a practical embodiment of the invention, 10 designates a container or cylinder which is provided with a bottom sleeve 11, detachably secured in place, as by the cooperating flanges 12 and 13 and the connecting bolts 14. A top closure 14A for the container 10 is detachably secured in place by the cooperating flanges 15 and 16 and the connecting bolts 14. A fixed cylindrical plunger guide 17 extends into the container 10 from the top closure 14A.
A pump plunger assembly 18, comprising an outer sleeve 19, an inner sleeve assembly 37, an intake valve 21, an exhaust valve 22, a charging valve 33, an exhaust valve 34 and a handle 23 which is one possible means to reciprocate the entire pump plunger assembly 18 which fits slidably into the fixed cylindrical plunger guide 17 and is sealed gas tight by the high pressure seal 26. The closed upper ends of the outer sleeve assembly 19 and the inner sleeve assembly 37 are connected to the intake valve 21 and exhaust valve 22 by channels 24, 30 and 25.
The inner sleeve assembly 37 is comprised of an inner sleeve 32, a connecting bolt 36 containing channel 30 which extends to the channels 24 and 25, cooperating gaskets 38 and 39 which are positioned about the connecting bolt 36 and a flexible membrane 20, a lower flexible membrane 48, cooperating gaskets 40 and 41, and plate 42. Connecting screws 43 detachably secure plate 42, flexible membrane 20, lower flexible membrane 48 and gaskets 40, 41 to the lower end of the inner sleeve 32. The connecting bolt 36 detachably secures the inner sleeve assembly 37 to the outer sleeve 19.
Referring further to the inner sleeve assembly 37 the flexible membranes 20 and 48 within a vertical channel 28 form two distinct free interior volumes or chambers 44 and 45 which completely contain the fluids or gases within them.
The chamber 44 is charged with fluid or gas 35 by means of the charging valve 33 and channel 46 and the fluid or gas is exhausted by means of the channel 47 and the exhaust valve 34.
The flexible membranes 20 and 48 may be composed of any suitable material and may be of any predetermined shape to form distinct free interior volumes or chambers with flexible walls within the vertical channel 28 of the pump plunger assembly 48 which completely contain the fluids or gases within them. The flexible membrane 20 is a common wall to both chambers. The chamber 44 may be charged with a fluid or gas 35 by means of the charging valve 33 and channel 46 and exhausted by means of the channel 47 and the exhaust valve 34 to achieve a desired interior profile within the plunger assembly 48 at any instant of time which may be varied instantaneously and at will, depending on the pressure and amount of the charging fluid or gas that is used and the flexibility of the membrane or the ability of the membrane to stretch.
The pressure within the chamber 44 should preferably be greater than the pressure in the chamber 45, so that the membrane 20 is the less flexible or stiffer wall of the chamber 45 which contains the fluid or gas 49 to be pumped.
The container 10 is filled with a fluid 27 to such a level that, at the top of the stroke of the plunger assembly, the bottom of the vertical channel 28 is immersed in the fluid 27. The vertical channel 28 may vary in cross sectional area from the open lower end 29 to the closed and valved upper end 30. Above the fluid 27 and within the chamber 45 is the fluid or gas 49 which is being circulated.
As the plunger assembly 18 shown in FIG. I is moved downwardly, the pumped fluid or gas 49 is displaced from the chamber 45 as the fluid 27 rises through plate 42 in a channel 28 because pressure is being exerted upon all of the fluids; the fluid 27, the pumped fluid and the charging fluid 25. This pressure can only be relieved as the pumped fluid escapes through the exhaust valve 22.
As the plunger assembly 18 shown in FIG. I is moved upwardly, the pumped fluid or gas 49 is drawn into the channels 24, 30 and chamber 45 because pressure is reduced until the partial vacuum thus formed is relieved as the pumped fluid or gas flows in through the intake valve 21.
As the fluid 27 rises and falls in the channel 28, drawing in and then exhausting the pumped fluid or gas 49 through the intake valve 21 and exhaust valve 22, the cross sectional area of the chamber 45 may be varied instantaneously and at will by means of simultaneously employing the charging valve 33 and relief or exhaust valve 34 to determine the pressure and amount of the charging fluid or gas 35 that is employed, thereby causing the flexible membrane 20 to expand or stretch as the fluid 27 rises and falls in the channel. Additionally, the relief valve 34 may be used to discharge the fluid or gas from within the chamber 45, allowing the flexible membrane to relax to some desired intermediate profile as a predetermined amount of fluid or gas is released, or the charging valve 33 may be employed to charge the fluid or gas within the chamber 45 to a higher pressure to cause the flexible membrane 20 to expand or stretch to achieve a desired interior profile within the channel. Therefore, if the surface of the fluid 27 on the lower flexible membrane 48 is considered as a piston face doing work on the pumped fluid 49 in the channel 28, a given amount of force on this piston face may either pump a smaller amount of the pumped fluid at a higher pressure or a larger amount of the pumped fluid at a lower pressure depending on the cross sectional area of the chamber 45 which may be varied instantaneously and at will and which determines the area of the hypothetical piston face. Therefore, as the configuration of the chamber 45 varies, this pump may have different and variable pressure to volume ratios in the different parts of a single stroke that may be predetermined or altered as desired in the different parts of a single stroke while a given force or thrust moves the piston which is the surface of the fluid 27 upon the lower flexible membrane 48 in the channel 28.
A wide selection of flexible membranes may be used with any given pump plunger assembly. The flexible membranes are replaceable within the pump plunger assembly if they tear or leak and any desired shape of flexible membrane of any desired material or combination of materials may be used at any given time to achieve a desired interior profile when charged or inflated with a charging fluid or gas. The flexible membranes may be formed by any suitable fabrication process, as for instance, they may be molded or they may be cut, formed and joined together by adhesive bonding or a vulcanizing process may be employed. The flexible membranes may be thermally conductive to conduct heat away from or transmit heat to the pumped fluid or gas employing the fluid 27 as either a heat sink or a heat source or by employing the charging fluid as either a heat sink or a heat source or by simultaneously employing both the charging and working fluids as heat sinks and/or heat sources to establish any desired thermal gradient within the fluid or gas being circulated. The thermal conductivity of the flexible membranes may thus be used to affect the stale point (pressure, volume, temperature) of the fluid or gas being pumped or circulated.
There are two necessary characteristics of fluid 27 and the charging fluid or gas 35 and the pumping fluid 49. The first is that the fluid within 27 the container be of greater density than the pumped fluid or gas 49 and the second is that all of the fluids or gases employed not mix or react in a harmful manner with each other or with the flexible membranes. Some examples of contemplated fluids and charging fluids would be mercury pumping oil, water or air. Water could be used as the fluid within the container and as the charging fluid to pump light oils, or it could be used to pump air or oxygen. It is to be understood that there are any number of possible combinations of fluids within the container and charging fluids or gases and pumped fluids or gases that may be used to practice this invention.
FIG. I shows one contemplated embodiment of my invention. FIG. III shows the pump plunger outer sleeve 19 which may be fabricated from metal or other suitable material by any standard precision means.
Having illustrated and described three preferred embodiments of my invention, it is to be understood that it 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 pump with a plunger assembly that is received within an outer housing containing a fluid. The plunger assembly includes a slidable sleeve portion defining a vertical channel. A pair of flexible membranes form outer and inner chambers within the vertical channel, one of the flexible membranes constituting a common wall that separates the chambers. A charging fluid is fed to the outer chamber through an inlet valve and exits therefrom through an exhaust valve. A fluid to be pumped is fed to the inner chamber through an inlet valve and exits therefrom through an exhaust valve. The charging fluid governs the interior profile within the vertical channel for providing variable pressure to volume ratios within the chambers.
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[0001] This application claims priority pursuant to 35 U.S.C. §119(e) to U.S. provisional application Ser. No. 61/443,598, filed Feb. 16, 2011, which application is specifically incorporated herein, in its entirety, by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to computer networking and, more particularly, to methods of and systems for transporting packets through a network while supporting packet traceback.
[0004] 2. Description of the Related Art
[0005] It is advantageous to trace a particular route by which a packet is transported through a network. However, packets that are transported through networks have fixed lengths while the number of hops each packet can take through a network vary widely. Allocating insufficient space to record the route of a packet within the packet defeats proper tracing of the route. Often, there are no limits on the number of hops a packet can take through a network and so there is no amount of space that can be reserved in a packet to guarantee accuracy for route tracing. Even in situations in which the number of hops a packet may take are limited, allocating space to record the maximum packet route in each packet will waste precious bandwidth for all packets taking less than the maximum packet route.
SUMMARY OF THE INVENTION
[0006] In accordance with the present invention, tokens identifying all of the physical routing devices, i.e., network nodes, through which a packet travels are recorded in a limited amount of space reserved in the header of the packet for such tokens. When insufficient space remains in the header of the packet for all tokens required to identify all physical routing devices through which the packet travels, sequences of multiple tokens are replaced with a single token representing the sequence.
[0007] The single token is sometimes referred to herein as an abbreviation token. The sequence of tokens represented by an abbreviation token can also be composed of abbreviation tokens, supporting recursive abbreviation of the token sequence in the header of the packet as needed to record the entire route of the packet through the network regardless of the limited space in the header for tracking the route of the packet.
[0008] To identify the physical nodes through which the packet travels, the tokens are derived from hardware features of each node, much the way a digital fingerprint is derived. Accordingly, identification of the physical nodes through which the packet travels cannot be defeated by spoofing easily reconfigurable attributes such as network addresses.
[0009] Various nodes of the network can learn the tokens of adjacent nodes of the network through interior gateway routing protocols such as RIP packets or Hello packets found in OSPF or similar protocols. Nodes can also encrypt the packet for secure hops using the token of the next node as an encryption key.
[0010] The abbreviation tokens can be produced in a manner that is consistent throughout all nodes of the network such that expansion of abbreviation tokens to reconstruct the route of the packet can be achieved by any device that knows the abbreviation token generation method.
[0011] The abbreviation tokens can also be generated by each node using its own particular method. In such cases, the node that generates an abbreviation token ensures that its own token immediately follows the abbreviation token to thereby identify itself as the node that can properly expand the abbreviation token. To reconstruct the route of a packet through the network, the node generating each abbreviation token is identified and asked to expand the abbreviation token.
[0012] Specifically, a first aspect of the present invention accordingly provides a method for routing a packet through a network from a source to a destination, the method comprising: storing data in a header of the packet to represent a complete route of the packet through the network, the data identifying at least one physical routing device of the network through which the packet travels.
[0013] In another form, the method further comprises replacing data identifying at least two physical routing devices with a single token in the header of the packet such that the single token identifies the at least two physical routing devices.
[0014] In another form, the method further comprises storing data in the header of the packet that identifies a particular physical routing device that performs the replacing.
[0015] In another form, the storing is performed by node logic executing within each physical routing device that receives the packet along the route.
[0016] In a second aspect, the present invention accordingly provides a method for identifying a particular route taken by a packet through a network, the method comprising:
[0017] retrieving one or more tokens from a header of the packet, the tokens collectively identifying one or more physical routing devices through which the packet traveled;
[0018] determining that at least a selected one of the tokens represent two or more other tokens; and replacing the selected with the two or more other tokens.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. Component parts shown in the drawings are not necessarily to scale, and may be exaggerated to better illustrate the important features of the invention. In the drawings, like reference numerals may designate like parts throughout the different views, wherein:
[0020] FIG. 1 is a diagram showing computers, including a node manager, connected through a computer network that includes a number of nodes that transport packets in accordance with the present invention.
[0021] FIG. 2 is a block diagram showing a node of FIG. 1 in greater detail.
[0022] FIG. 3 is a logic flow diagram of the transport of a packet by the node of FIG. 1 in accordance with the present invention.
[0023] FIG. 4 is a logic flow diagram showing a step of the logic flow diagram of FIG. 3 in greater detail.
[0024] FIG. 5 is a logic flow diagram showing a step of the logic flow diagram of FIG. 4 in greater detail.
[0025] FIG. 6 is a block diagram of a token definition of the token database of FIG. 2 in greater detail.
[0026] FIG. 7 is a block diagram of a packet that includes a number of token slots in its header in accordance with the present invention.
[0027] FIGS. 8A-8E are block diagrams illustrating the recording of the route of a packet, including the use of abbreviation tokens.
[0028] FIG. 9 is a logic flow diagram illustrating the reconstruction of the route taken by a packet through the network of FIG. 1 .
[0029] FIGS. 10A-10E are block diagrams illustrating the reconstruction of the route recorded in FIGS. 8A-8E according to the logic flow diagram of FIG. 9 .
DETAILED DESCRIPTION
[0030] In accordance with the present invention, nodes 108 A-I of network 106 transport packets in a manner that records the full route of each packet through network 106 while requiring a relatively small portion of fixed size within each packet for the recording. The route identifies individual, specific ones of nodes 108 A-I and not merely IP addresses or other easily configurable or modifiable characteristics of nodes 108 A-I.
[0031] As described more completely below, each of nodes 108 A-I has an identifying token that is unique among tokens of nodes within network 106 . The identifier is derived from data specific to each of nodes 108 A-I such that the identifier identifies a specific node device. When a packet is routed to any of nodes 108 A-I, the receiving node records its token within the packet to thereby record the receiving node as part of the route of the packet. When recorded tokens have filled the limited space of the packet allocated for recording the route, a receiving node replaces multiple tokens in the recorded route with a single token that represents the sequence of replaced tokens, to thereby free space to record additional tokens of the packet's route.
[0032] Before describing the recording of a packet's route through network 106 in accordance with the present invention, some elements of node 108 A ( FIG. 1 ) are briefly described. Nodes 108 A-I are analogous to one another and the following description of node 108 A is equally applicable to each of nodes 108 B-I except as noted herein.
[0033] Node 108 A is shown in greater detail in FIG. 2 and includes one or more microprocessors 202 (collectively referred to as CPU 202 ) that retrieve data and/or instructions from memory 204 and execute retrieved instructions in a conventional manner. Memory 204 can include generally any computer-readable medium including, for example, persistent memory such as magnetic and/or optical disks, ROM, and PROM and volatile memory such as RAM.
[0034] CPU 202 and memory 204 are connected to one another through a conventional interconnect 206 , which is a bus in this illustrative embodiment and which connects CPU 202 and memory 204 to network access circuitry 208 . Network access circuitry 208 sends and receives data through a network 106 ( FIG. 1 ) and includes ethernet circuitry or fiber optic circuitry in some embodiments.
[0035] Node 108 A is shown without user input and output, i.e., user-interface devices. While many nodes of a network do not have user-interface devices, some nodes are computers intended to be used by a person and therefore do include user-interface devices.
[0036] A number of components of node 108 A are stored in memory 204 . In particular, routing logic 210 is all or part of one or more computer processes executing within CPU 202 from memory 204 in this illustrative embodiment but can also be implemented using digital logic circuitry. As used herein, “logic” refers to (i) logic implemented as computer instructions and/or data within one or more computer processes and/or (ii) logic implemented in electronic circuitry. Routing table 212 and token table 214 are data stored persistently in memory 204 . In this illustrative embodiment, routing table 212 and token table 214 are each organized as a database.
[0037] Logic flow diagram 300 ( FIG. 3 ) illustrates the processing of packets by routing logic 210 of node 108 A to thereby transport the packets through network 106 . In step 302 , routing logic 210 receives the packet through network access circuitry 208 ( FIG. 2 ). In step 304 ( FIG. 3 ), routing logic 210 determines the next node to which the packet should be sent toward the packet's ultimate destination through network 106 by reference to routing table 212 ( FIG. 2 ). Steps 302 ( FIG. 3) and 304 are conventional and are known and are not described further herein.
[0038] In step 306 , routing logic 210 tags the packet with the token of node 108 A in a manner described more completely below in conjunction with logic flow diagram 306 ( FIG. 4 ). In alternative embodiments, routing logic 210 can tag the packet with the token of the next node determined in step 304 in addition to or instead of tagging the packet with the token of node 108 A. In such alternative embodiments, node 108 A at least knows the token of each adjacent node among nodes 108 A-I and stores all known tokens in routing table 212 ( FIG. 2 ). In embodiments in which nodes 108 A-I know each other's tokens, nodes 108 A-I inform one another of their tokens in a manner described below during network configuration.
[0039] In step 308 ( FIG. 3 ), routing logic 210 sends the packet as tagged to the next node toward the ultimate destination of the packet through network 106 . The sending of a packet to a next node is conventional and known and not described further herein. However, in some embodiments in which each of nodes 108 A-I knows the tokens of at least its adjacent nodes, the sending node can encrypt payload 706 of the packet for the next node, thereby preventing interception of the packet by an unauthorized node or other nefarious logic that might be injected into either node 108 A or the node to which node 108 A sends the packet.
[0040] Logic flow diagram 306 ( FIG. 4 ) shows step 306 in greater detail. In step 402 , routing logic 210 finds the first empty token slot of the packet. An example of a packet transported by node 108 A is shown as packet 702 ( FIG. 7 ).
[0041] Packet 702 includes a header 704 and a payload 706 . Payload 706 is that portion of packet 702 that is data intended to be transported through network 106 and is conventional. Header 704 is mostly conventional except that header 704 includes a number of token slots 708 A-C, each of which can store a single token. In this illustrative embodiment, each token is 16 octets in length and header 704 can store three (3) tokens, one in each of token slots 708 A-C. Of course, tokens can be of different lengths and header 704 can include different numbers of token slots in alternative embodiments.
[0042] In this illustrative embodiment, an empty token slot stores all zeros. Accordingly, 16 octets of all zeros is not a valid token. Thus, routing logic 210 finds the first empty token slot by identifying the first of token slots 708 A-C that stores all zeros.
[0043] In test step 404 ( FIG. 4 ), routing logic 210 determines whether an empty token slot was found in step 402 .
[0044] If so, processing transfers to step 414 in which routing logic 210 stores the token of node 108 A into the first empty token slot of the packet. As noted above, routing logic 210 can store the token of the next node in the first empty slot of the packet, first ensuring that the token of node 108 A is stored in the immediately preceding token slot.
[0045] Conversely, if routing logic 210 did not find an empty token slot in step 402 , processing by routing logic 210 transfers from test step 404 to step 406 .
[0046] In step 406 , routing logic 210 retrieves the tokens from the packet, e.g., retrieves the tokens stored in token slots 708 A-C.
[0047] In step 408 , routing logic 210 determines an abbreviation for a sequence of at least two tokens in a manner described more completely below with respect to logic flow diagram 408 ( FIG. 5 ). The abbreviation is itself a token that is unique among all tokens known to node 108 A and all tokens for any nodes of network 106 .
[0048] In step 410 , routing logic 210 replaces the two or more tokens represented by the abbreviation with the abbreviation itself. Since the abbreviation is a single token replacing at least two other tokens, at least one token slot will be freed and therefore empty. Routing logic 210 marks the token slots freed by replacement with the abbreviation as empty by storing all zeros therein.
[0049] In step 412 , routing logic 210 identifies the first empty token slot after the abbreviation substitution of step 410 .
[0050] Processing transfers from step 412 to step 414 in which routing logic 210 stores the token of node 108 A into the first empty token slot of the packet as described above. After step 414 , processing according to logic flow diagram 306 ends, and therefore step 306 ( FIG. 3 ), completes.
[0051] Step 408 ( FIG. 4 ) is shown in greater detail as logic flow diagram 408 ( FIG. 5 ).
[0052] In step 502 , routing logic 210 retrieves, from token table 214 ( FIG. 2 ), an abbreviation token that represents the full sequence of tokens retrieved from token slots 708 A-C of the subject packet. In other embodiments, routing logic 210 can also retrieve an abbreviation token that represents a contiguous sub-sequence of the full sequence of retrieved tokens.
[0053] Token table 214 includes one or more token definitions such as token definition 602 ( FIG. 6 ). Token definition 602 includes a token 604 and a definition 606 . Definition 606 is a sequence of two or more tokens. Token 604 is a token that is an abbreviation of the sequence of tokens represented in definition 606 .
[0054] To identify an abbreviation for a sequence of two or more tokens, routing logic 210 searches token table 214 for a token definition whose definition 606 is that sequence. The corresponding token 604 is the abbreviation.
[0055] In test step 504 ( FIG. 5 ), routing logic 210 determines whether an abbreviation was found within token table 214 in step 502 . If so, routing logic 210 determines, in step 506 , that the retrieved abbreviation is the appropriate abbreviation for the sequence of tokens and processing according to logic flow diagram 408 , and therefore step 408 ( FIG. 4 ) completes.
[0056] In alternative embodiments, routing logic 210 can use a hashing function to map multiple tokens to a single abbreviation token. In such embodiments, the look-up and test of steps 502 and 504 can be replaced with a single hashing step. In some embodiments, the hashing function is designed to avoid producing hashed tokens that can be confused with a node token. Processing from such a hashing step would transfer to step 506 , which is described above.
[0057] Returning to logic flow diagram 408 ( FIG. 5 ), if an abbreviation was not found within token table 214 in step 502 , processing by routing logic 210 transfers from test step 504 to step 508 .
[0058] In step 508 , routing logic 210 creates a token that is unique from all abbreviation tokens stored in token table 214 ( FIG. 2 ) and from all tokens of nodes in network 106 ( FIG. 1 ). In this illustrative embodiment, the total range of values for legitimate tokens is divided into a range reserved for nodes of network 106 and a range that each of nodes 108 A-I can use in their respective token tables 214 . For example, for a token 16 octets in length, all tokens in which the most significant octet is zero can be reserved for tokens of nodes of network 106 . That would leave roughly seven times as many tokens for representing sequences of tokens within each node. Similar rules may be applied in other embodiments where the token has a length other than 16 octets. For example, in a system having token lengths of 4 octets, all tokens in which the most significant bit is zero can be reserved for tokens of nodes of network 106 , while all other 4-octet tokens may represent token sequences.
[0059] Each of nodes 108 A-I is informed of the reserved token range during the registration process by which each node is assigned its own token. During system configuration, each of nodes 108 A-I registers with node manager 110 , identifying itself with a digital fingerprint in this illustrative embodiment. Digital fingerprints are known and are described, e.g., in U.S. Pat. No. 5,490,216 and that description is incorporated herein by reference. In general, a digital fingerprint uniquely identifies the physical device (e.g., a computer or router) based on a sampling of user-configurable and/or non-user-configurable machine parameters readable from the device, wherein each parameter may represent a particular hardware or a software configuration associated with the device.
[0060] It should be appreciated that the token created by routing logic 210 in step 508 need not be unique with respect to tokens used by nodes 108 B-I in their respective token tables. As a result, routing logic 210 of node 108 A need not consult any other node or computer to create an adequately unique new token in step 508 , thus avoiding significant delay in transport of the subject packet to its ultimate destination through network 106 . However, in such embodiments, routing logic 210 of node 108 A should take care to not replace the last token of node 108 A with an abbreviation as the last token of node 108 A identifies node 108 A as the particular one of nodes 108 A-I that is capable of reversing the abbreviation. In alternative embodiments, creation of an abbreviation token for multiple other tokens can be performed in a way that is both deterministic and global within nodes 108 A-I such that an abbreviation used by any of nodes 108 A-I can be properly reversed by any of nodes 108 A-I. In these alternative embodiments, routing logic 210 of node 108 A can replace the last token of node 108 A with an abbreviation.
[0061] In step 510 , routing logic 210 creates a new token definition that associates the token created in step 508 with the sequence of tokens to be replaced with the new token.
[0062] In step 512 , routing logic 210 returns the token created in step 508 as the abbreviation token and ends processing according to logic flow diagram 408 , and therefore step 408 ( FIG. 4 ) completes.
[0063] To illustrate the packet transportation described above, the recording of a route of a packet transported through network 106 ( FIG. 1 ) from computer 102 to computer 104 is described. As shown in FIG. 1 , computer 102 connects to network 106 through node 108 A. Accordingly, node 108 A is the first to process a packet from computer 102 .
[0064] As shown in FIG. 8A , token slots 708 A-C of the packet are initially all empty. Performance of step 306 by node 108 A results in node 108 A storing its token in the first empty token slot, i.e., in token slot 708 A in this illustrative example. Node 108 A forwards the packet so tagged to node 108 C.
[0065] As shown in FIG. 8B , when received by node 108 C, token slot 708 A stores the token of node 108 A and token slots 708 B-C of the packet are initially empty. Performance of step 306 by node 108 C results in node 108 C storing its token in the first empty token slot, i.e., in token slot 708 B in this illustrative example. Node 108 C forwards the packet so tagged to node 108 F.
[0066] As shown in FIG. 8C , when received by node 108 F, token slot 708 A stores the token of node 108 A, token slot 708 B stores the token of node 108 C, and token slot 708 C is empty. Performance of step 306 by node 108 F results in node 108 F storing its token in the first empty token slot, i.e., in token slot 708 C in this illustrative example. Node 108 F forwards the packet so tagged to node 108 H.
[0067] As shown in FIG. 8D , when received by node 108 H, token slot 708 A stores the token of node 108 A, token slot 708 B stores the token of node 108 C, and token slot 708 C stores the token of node 108 F. None of token slots 708 A-C is empty. Performance of step 306 by node 108 H results in (i) replacement of the sequence of tokens for nodes 108 A, 108 C, and 108 F with an abbreviation 802 and (ii) node 108 H storing its token in the first empty token slot, i.e., in token slot 708 B in this illustrative example. Replacing three (3) tokens with one (1) frees up two token slots in the subject packet. In addition, since the token of node 108 H immediately follows abbreviation 802 , node 108 H is marked as the author of abbreviation 802 . Such is used in reconstructing the route of the subject packet in the manner described below. Node 108 H forwards the packet so tagged to node 108 I.
[0068] Node 108 I processes the packet in an analogous manner and stores its own token in token slot 708 C as shown in FIG. 8E . It should be appreciated that another node can replace abbreviation 802 , the token of node 108 H, and the token of node 108 I with another abbreviation token. Node 108 I forward the packet tagged with the token of node 108 I to computer 104 , to thereby effect delivery of the packet to computer 104 .
[0069] Tracing a route taken by a particular packet is illustrated by logic flow diagram 900 ( FIG. 9 ). The steps of logic flow diagram can be performed by logic in any of nodes 108 A-I, node manager 110 , and computers 102 and 104 . For the purposes of current discussion, the logic is referred to as “traceback logic”.
[0070] The traceback logic stores a route 1002 ( FIGS. 10A-E ) and a token list 1004 , both of which are lists of tokens. Initially, route 1002 is empty and token list 1004 includes the tokens stored in token slots 708 A-C of the subject packet, as shown in FIG. 10A .
[0071] Loop step 902 and next step 914 define a loop in which the traceback logic processes route 1002 and token list 1004 according to steps 904 - 912 until token list 1004 is empty.
[0072] In step 904 , the traceback logic pops the last token from token list 1004 . As used herein, popping the token from token list 1004 means retrieving the token from the last position in token list 1004 and removing the retrieved token from token list 1004 . As shown in FIG. 10A , the last token of token list 1004 identifies node 108 I.
[0073] In test step 906 , the traceback logic determines whether the popped token identifies a node. If so, processing transfers to step 908 . Conversely, if the popped token does not identify a node, processing by the traceback logic transfers from test step 906 to step 910 .
[0074] In this illustrative example, the token popped from the last position in token list 1004 is the token of node 108 I. Accordingly, processing by the traceback logic transfers to step 908 in which the traceback logic pushes the popped token onto the beginning of route 1002 . The result is shown in FIG. 10B in which the token for node 108 I is popped from the end of token list 1004 and is pushed on to the beginning of route 1002 .
[0075] After step 908 , processing by the traceback logic transfers to next step 914 , in which the loop of steps 902 - 914 are repeated if token list 1004 is not empty.
[0076] In the next iteration of the loop of steps 902 - 914 in this illustrative example, the traceback logic pops the token of node 108 H from the end of token list 1004 and pushes the token on to the beginning of route 1002 in an analogous manner. The result is shown in FIG. 10C .
[0077] In the next iteration of the loop of steps 902 - 914 in this illustrative example, the traceback logic pops abbreviation 802 ( FIG. 10C ) from the end of token list 1004 . In test step 906 ( FIG. 9 ), the traceback logic determines that abbreviation 802 is not a node token and processing of the traceback logic transfers to step 910 .
[0078] In step 910 , the traceback logic queries the node whose token is at the top of route 1002 ( FIG. 10C ) for expansion of abbreviation 802 . It should be appreciated that, in embodiments such as those described above in which an abbreviation is a hash of the multiple tokens and is produced in a manner shared by all of nodes 108 A-I, it is unnecessary to query the particular one of nodes 108 A-I that stored abbreviation 802 in the packet and step 910 is therefore obviated. However, as described above in some embodiments, each of nodes 108 A-I maintains its own token table 214 ( FIG. 2 ) separately and independently of other nodes of network 106 . Accordingly, the only node of network 106 that can expand abbreviation 802 in this illustrative embodiment is the node that created abbreviation 802 . Since the node that created abbreviation 802 in a performance of step 408 ( FIG. 4 ) stored its own token in the subject packet in step 414 , the token immediately following abbreviation 802 identifies the node that authored abbreviation 802 .
[0079] As shown in FIG. 10C , the token of node 108 H is at the top of route 1002 and is therefore the node that created abbreviation 802 . The traceback logic therefore queries node 108 H for expansion of abbreviation 802 in step 910 . Each of nodes 108 A-I is configured to receive requests for expansion of abbreviation tokens and to respond by returning the sequence of tokens associated with the received abbreviation token within token table 214 . In this illustrative example, node 108 H responds with the sequence described above, namely, tokens for nodes 108 A, 108 C, and 108 F in order.
[0080] In step 912 , the traceback logic appends the token sequence received in step 910 to token list 1004 ( FIG. 10D ). As shown in FIG. 10D , token list 1004 does not include abbreviation 802 (popped from token list 1004 in step 904 ) and includes the expansion thereof (appended in step 912 ). It should be appreciated that the token list resulting from expansion of abbreviation 802 can include other abbreviations, including abbreviations authored by other nodes.
[0081] Subsequent iterations of the loop of steps 902 - 914 ( FIG. 9 ) by the traceback logic result in moving the tokens of nodes 108 F, 108 C, and 108 A from the end of token list 1004 to route 1002 in sequence until token list 1004 is empty, as shown in FIG. 10E .
[0082] Thus, in accordance with the present invention, a route of five (5) hops was completely recorded and reconstructed from only three (3) slots available to record nodes to which the packet hopped. Given the recursive nature of the recording of the nodes as described above, i.e., that abbreviations of token sequences can themselves include abbreviations of token sequences that can in turn include abbreviations of token sequences, the length of a packet route through a network that can be traced is unlimited, aside from the practical limitations of the collective capacity of token table 214 of all nodes of the network.
[0083] As described above, some embodiments require that each of nodes 108 A-I knows all the tokens of at least its adjacent nodes, i.e. those of nodes 108 A-I with which data is directly exchanged. Of course, all of nodes 108 A-I can know the tokens of all others of nodes 108 A-I, but such is not always necessary. For example, since node 108 A never directly exchanges data with node 108 D, node 108 A is not always required to have the token of node 108 D.
[0084] As described briefly, each of nodes 108 A-I receives a token from node manager 110 . Node manager 110 derives the token from a digital fingerprint of each node. Thus, the token identifies the particular physical device that acts as a node and not an easily reconfigurable attribute such as a network address.
[0085] Nodes 108 A-I learn the tokens of others of nodes 108 A-I during route configuration. Route configuration involves an exchange of information among nodes 108 A-I to build routing table 212 . In particular, each of nodes 108 A-I builds a routing table such that a given destination address of a packet indicates to which node the packet should be forwarded. Conventional route configuration protocols include RIP (Routing Information Protocol), EIGRP (Enhanced Interior Gateway Routing Protocol), and OSPF (Open Shortest Path First).
[0086] In each such route configuration protocol, one or more packets are exchanged between nodes 108 A-I to share various elements of information of nodes 108 A-I that can be used by each of nodes 108 A-I to properly identify a next node in routing a particular packet to its destination. In this illustrative embodiment, nodes 108 A-I include their respective tokens assigned by node manager 110 in such route configuration packets, either by including the token as a field in a packet conveying other items of information (such as an additional field in a RIP packet) or as an additional packet such as a Hello packet in EIGRP or OSPF.
[0087] The above description is illustrative only and is not limiting. The present invention is defined solely by the claims which follow and their full range of equivalents. It is intended that the following appended claims be interpreted as including all such alterations, modifications, permutations, and substitute equivalents as fall within the true spirit and scope of the present invention.
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Tokens identifying all of the physical routing devices, i.e., network nodes, through which a packet travels are recorded in a limited amount of space reserved in the header of the packet for such tokens. When insufficient space remains in the header of the packet for all tokens required to identify all physical routing devices through which the packet travels, sequences of multiple tokens are replaced with an abbreviation token representing the sequence. The sequence of tokens represented by an abbreviation token can also be abbreviation tokens, supporting recursive abbreviation of the token sequence in the header of the packet as needed to record the entire route of the packet through the network regardless of the limited space in the header for tracking the route of the packet.
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FIELD OF THE INVENTION
The present invention relates generally to a closed molding process that produces cured composite parts, and more particularly, to a method for producing multiple composite parts via resin transfer molding in a single cycle.
BACKGROUND OF THE INVENTION
Resin Transfer Molding (RTM) is a process that uses a closed mold to produce cured composite parts. A dry fabric preform is placed in the mold cavity, the mold is closed and a resin in injected into the mold. The mold is exposed to an elevated curing temperature, and after a predetermined curing cycle has elapsed, a finished part is removed from the mold. The part is then ready for final trim.
Prior RTM processes are only capable of producing one composite part for each cycle. Therefore, after each cycle the RTM molding tool must be cleaned or reprocessed for the next injection.
Another disadvantage of the known RTM processes is the cost of low-tolerance tooling Typical aerospace applications for RTM, for example, will require a part to be formed to a predetermined thickness within about ±0.025 mm (±0.001 in.). As those skilled in the art will readily understand, the fabrication of the tooling having this capability is relatively expensive, often costing 20-35% more than similar tooling having more open tolerances.
Accordingly, there remains a need in the art for an RTM tool and method that is capable of producing a plurality of highly consistent molded parts in a single molding cycle that overcomes the aforementioned drawbacks.
SUMMARY OF THE INVENTION
The Resin Transfer Molding Multi-Part/Shim Tooling (RTM-MPST) process overcomes this disadvantage by injecting resin into the mold cavity thus flooding multiple parts and shims, the pressure is distributed hydrostatically (evenly in all directions). This distributes the tolerance across each of the parts and with more shims in the cavity, the closer the parts will be to nominal thickness in a cost effective manner.
In one preferred form, the present invention provides a method for forming a plurality of composite parts via resin transfer molding in a single molding cycle. The method includes the steps of providing a mold having first and second mold members that cooperate to define a mold cavity; providing a plurality of shims; loading a plurality of preform workpieces into the mold cavity such that at least one of the shims is disposed between each of an adjacent pair of the preform workpieces; injecting a liquid resin into the mold cavity; curing the liquid resin to thereby form a cured workpiece matrix that is composed of a plurality of semi-finished composite parts and the at least one shim; and separating the plurality of semi-finished composite parts and the at least one shim from one another.
In another preferred form, the present invention provides a mold apparatus for performing a resin transfer molding operation on a plurality of preform workpieces to substantially simultaneously mold a plurality of semi-finished composite parts in a single molding cycle. The mold apparatus includes a first mold member, which defines a first mold line, a second mold member, which defines a second mold line, and at least one shim. The second mold member cooperates with the first mold member to define a mold cavity that is bounded by the first and second mold lines. The shim(s) are sized to fit within the mold cavity and are configured to be spaced in relation to the first and second mold lines to thereby segregate the mold cavity into a plurality of sub-cavities. Each of the sub-cavities is configured to house one of the perform workpieces. With the present invention, (RTM-MPST) produces multiple composite parts in one cycle thereby reducing the frequency that the tool is reprocessed and reduces resin waste.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a side elevation view of a molding apparatus constructed in accordance with the teachings of the present invention;
FIG. 2 is a sectional view of a portion of the molding apparatus of FIG. 1 illustrating the mold assembly in greater detail;
FIG. 3 is an exploded perspective view illustrating the arrangement of the composite preforms and shims as they would be loaded into the mold cavity prior to the injection of a liquid resin; and
FIG. 4 is an exploded perspective view illustrating the semi-finished composite parts and shims as separated from one another after their removal from the mold cavity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1 of the drawings, a molding apparatus 10 is illustrated to include a mold assembly 12 that is constructed in accordance with the teachings of the present invention. The molding apparatus 10 is also illustrated to include a base 14 , an upper platten 16 , a lower platten 18 , a ram 20 , a control unit 22 a plurality of upright guides 24 a , 24 b and a mold assembly 12 . The base 14 , the upper and lower plattens 16 and 18 , the ram 20 , the control unit 22 and the upright guides 24 a , 24 b comprise a conventional molding press 10 of the type that is suited for resin transfer molding. Since such presses are well known in the art and as such, a detailed discussion of their construction and operation need not be provided herein. Briefly, in the example provided, the upright guides 24 a , 24 b are coupled to the base 14 and serve to fix the upper platten 16 in a predetermined spaced relation from the base 14 . The ram 20 is illustrated to be coupled to both the base 14 and the lower platten 18 . The ram 20 is conventionally hydraulically actuated via a hydraulic power source (not shown) to permit the lower platten 18 to be raised and lowered relative to the upper platten 16 in a desired manner. The upright guides 24 a , 24 b conventionally guide the lower platten 18 as it is being raised and lowered. The control unit 22 is coupled to and operable for controlling the source of hydraulic power and the heating elements (not shown) within each of the upper and lower plattens 16 and 18 . The control unit 22 may be configured to control the source of hydraulic power such that the ram 20 positions the lower platten 18 at a predetermined distance from the upper platten 16 , or may be simply configured to exert a predetermined force or pressure onto the upper and lower plattens 16 and 18 . When actuated by the control unit 22 , the heating elements generate heat that is transmitted through the upper and lower plattens 16 and 18 to the mold assembly 12 .
With additional reference to FIG. 2, the mold assembly 12 includes a first mold member 32 , a second mold member 34 , a resin inlet conduit 36 , a resin outlet conduit (not shown) and at least one shim member 40 . The first and second mold members 32 and 34 are illustrated to define a mold cavity 42 having a predetermined size and thickness. The resin inlet 36 provides a means for facilitating the introduction of a liquid resin into the mold cavity 42 , while the resin outlet provides a means for facilitating the evacuation of air from the mold cavity 42 .
The shims 40 are disposed within the mold cavity 42 and operably segregate the mold cavity 42 into a plurality of sub-cavities 44 . The shims 40 are preferably “free-floating” within the mold cavity 42 and as such, are formed to a size (e.g., length and width) that are relatively smaller than the size of the mold cavity 42 . In the example provided, the shims 40 are perishable, being disposed of after one or more molding cycles. The quantity of shims 40 in the mold cavity 42 , as well as their thickness, are dependant upon several factors, which may include, for example, the actual depth of the mold cavity, the quantity of composite parts that are to be formed in a single molding cycle and the thickness tolerance of the finished composite parts.
In the particular example provide, the finished composite parts that are to be formed in the mold assembly 12 are substantially flat panels having a thickness tolerance of about +/−0.0254 mm (+/−0.001 inch). As noted above, the fabrication of tooling that would reliably and repeatably meet this thickness tolerance is extremely expensive, whereas tooling having “standard”, more open tolerances, e.g., ±0.127 mm (±0.005 inch), often costs as much as 35% less. As, in the example provided, both improved processing efficiency and reduced tooling costs are desirable, a decision is made prior to the construction of the mold assembly 12 as to what tolerances are to be used with regard to the overall depth of the mold cavity 42 . For illustrative purposes, the example provided herein will assume a tolerance of ±127 mm (±0.005 inch) with regard to the overall depth of the mold cavity 42 ; this tolerance will hereinafter be referred to as the mold cavity tolerance.
It should be noted that the mold cavity tolerance exceeds the thickness tolerance for the finished composite parts, i.e., ±0.0254 mm (±0.001 inch). The segregation of the mold cavity 42 by the shims 40 into a plurality of sub-cavities 44 , however, permits the mold cavity tolerance to be substantially equally distributed to each of the sub-cavities 44 . With the mold cavity tolerance (MCT) and the thickness tolerance (TT) of the finished composite parts being known quantities, the quantity (Q) of finished composite parts that are to be formed in a single molding cycle is determined from the equation:
Q ≧( MCT÷TT ).
Accordingly, the mold cavity 42 must be sized for a minimum quantity of five (5) sub-cavities 44 to ensure that each composite part that is formed in the mold assembly 12 meets the desired thickness tolerance. As those skilled in the art will understand, the mold cavity 42 may, of course, be sized for a greater quantity of sub-cavities 44 to thereby achieve improved processing efficiency and improved process capability.
With concerns for tolerances, processing efficiency and process capability being accounted for when determining the number of sub-cavities 44 that are to be formed within the mold cavity 42 , the overall depth of the mold cavity 42 is then determined. This is determined with reference to the number of finished composite parts that are to be formed in a single molding cycle (i.e., the number of sub-cavities 44 ), the nominal thickness of each of the finished composite parts, and the nominal thickness of the shims 40 that form the sub-cavities 44 .
The mold assembly 12 thus formed is loaded with the shims 40 and a plurality of composite preform workpieces 46 as shown in FIG. 3 .
After the preforms and shims are loaded into the mold cavity, the mold members are closed and a liquid resin is injected into the mold cavity via the resin inlet conduit. The liquid resin is pressurized to a predetermined pressure. As the resin outlet conduit permits air within the mold cavity to escape, a pressure differential across the mold cavity is generated, permitting the liquid resin to fully infiltrate and surround each of the sub-cavities, thereby coating and/or penetrating each of the composite preform workpieces with resin.
Once the air has been completely evacuated from the mold cavity and resin is exiting the mold assembly from the resin outlet conduit, the supply of liquid resin to the mold assembly is halted and the heating elements within the upper and lower plattens are actuated by the control unit to heat the mold assembly and cure the resin within the mold cavity.
When the resin within the mold cavity has cured sufficiently after the mold assembly's exposure to a predetermined elevated temperature and the elapse of a predetermined amount of time, the mold assembly is opened and a cured workpiece matrix 50 is removed from the mold cavity, as shown in FIG. 4 .
While the finished composite parts that are formed via the single molding cycle of the present invention are described herein as being substantially flat panels, those skilled in the art will understand that composite parts having other contours may also be molded. For example, the construction of a panel that conforms to a spherical radius may be readily undertaken assuming, of course, that the tolerance on the radius is sufficiently large to permit the deviations that would occur from the successive layering of one or more shims and composite preform workpieces onto the lower mold member. In this regard, it is preferable to form the lower mold member such that it will form the semi-finished composite part that contacts it to a radius that is at or just slightly greater than the minimum spherical radius to which the panels are to be formed. Construction of the mold assembly in this manner permits the maximization of the number of spherical panels that are formed in the single molding cycle. Those skilled in the art will understand that the contour of the upper mold member will be different from that of the lower mold member, as the radius to which it is formed is greater than that for the lower mold member by an amount that is related to the number of shims and composite preform workpieces that are disposed between the upper and lower mold members.
While the invention has been described in the specification and illustrated in the drawings with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined in the claims. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling within the foregoing description and the appended claims.
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A method for forming a plurality of composite parts via resin transfer molding in a single molding cycle. The method includes the steps of using a mold having first and second mold members that cooperate to house a plurality of shims and placing a plurality of preform workpiece into the mold cavity such that at least one of the shims is disposed between each of an adjacent pair of the preform workpieces. A liquid resin is then injected into the mold cavity and subsequently cured to thereby form a cured workpiece matrix that is composed of a plurality of semi-finished composite parts and at least one shim separating the plurality of semi-finished composite parts from one another.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority based on U.S. Provisional Patent Application No. 60/467,871, filed May 5, 2003, which is hereby incorporated by reference in full.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of small-scale generation of ammonia.
BACKGROUND OF THE INVENTION
[0003] A by-product of the combustion process is often the production of nitrogen oxides (“NOx”). (For all purposes herein, nitrogen oxides or NOx shall comprise all forms of N y O z , where y and z are respectively and independently 1 or greater.) Large amounts of nitrogen oxides are formed in combustion processes that incorporate air because nitrogen is present in both fuel and air. As combustion temperature increases, so does the formation of nitrogen oxides.
[0004] The most common oxides are NO (nitrogen monoxide) and NO 2 (nitrogen dioxide). NO is the dominant nitrogen oxide in exhaust gases. In the atmosphere NO rapidly oxidizes into NO 2 . Nitrogen oxides are believed to have a negative impact on the environment, contributing to “acid rain” and causing the formation of photochemical oxidants (such as ozone).
[0005] There is a great need for devices and strategies to control NOx production and emissions. Sources of NOx include open and internal combustion processes that are used to provide power for industry, transportation, human comfort, and waste reduction. Many of these are operated in a manner that generates at least a small concentration of NOx in exhaust gases. As a consequence, a large effort is focused on the removal of NOx from the exhaust gases by after-treatment.
[0006] One strategy to reduce NOx emissions involves selective catalytic reduction (“SCR”). SCR is often used to reduce nitrogen oxide emissions from the internal combustion engines of motor vehicles. In the SCR process, nitrogen oxides are reduced primarily through the following reactions:
Catalyst NO + NO 2 + 2NH 3 → 2N 2 + 3H 2 O 4NO + 4NH 3 + O 2 → 4N 2 + 6H 2 O 2NO 2 + 4NH 3 + O 2 → 3N 2 + 6H 2 O 4NO + 4NH 3 → 5N 2 + 6H 2 O 6NO 2 + 8NH 3 → 7N 2 + 12H 2 O
[0007] As these formulae indicate, SCR reduces nitrogen oxides in exhaust gases to nitrogen and water through the use of a catalyst and ammonia (“NH 3 ”), or an ammonia-producing compound like urea, as the reduction agent. Thus, SCR requires an ammonia source.
[0008] Various industrial and transportation processes might also benefit from the use of relatively small quantities of ammonia. Many NOx reducing applications used with large, stationary, industrial processes employ ammonia gas that is delivered into the exhaust stream before it reaches the catalyst bed. The ammonia is stored in gaseous form under high pressure or as a liquid, and the storage containers are periodically refilled or exchanged for a full reservoir. In practice, the need to store the compressed or liquid ammonia on-site may raise technical, safety, or security concerns that may make such an application of stored or compressed ammonia unacceptable.
[0009] Unattended internal combustion engines also may require devices and strategies to control NOx production and emissions. Many of these engines, as one example only, power generators for oil and natural gas wells, are often located in remote areas that are difficult to access routinely. The re-supply of ammonia or urea for NOx reduction to these locations may be expensive or impractical. Consequently, reducing or eliminating the need to re-supply ammonia or urea for NOx reduction for such engines would reduce the costs associated with transportation of required fluids.
[0010] An immediate need for devices and strategies to control NOx emissions is in internal combustion engines used in the transportation industry. Current mandates by the U.S. Environmental Protection Agency (“EPA”) require increasingly tighter control of NOx emissions from internal combustion engines.
[0011] The need to reduce the quantity of NOx emitted by diesel engines on trucks is addressed by various approaches. One way to reduce the NOx from such emissions is by injecting ammonia into the exhaust stream over a catalyst bed to form nitrogen gas and water. However, a need remains for a solution that reduces NOx in the exhaust gases without requiring the use of special high pressure gases or liquid solutions that must be purchased separately.
[0012] One solution for these unmet needs would be the on-demand synthesis of ammonia in miniature ammonia plants without storage of pure ammonia, or with minimal storage, that does not represent a significant safety or security hazard.
SUMMARY OF THE INVENTION
[0013] The present invention comprises methods and apparatus to address these needs through the small scale generation of ammonia. In one embodiment, without limitation, the present invention comprises an on-board micro ammonia synthesis plant that offers a solution of NOx reduction without the hazards and inconvenience of carrying a secondary fluid on a motor vehicle. Thus, one embodiment of the present invention comprises a micro ammonia plant that controllably produces and stores ammonia that is used to reduce NOx levels in the exhaust streams of internal combustion engines. Other embodiments of the invention comprise, without limitation, methods and apparatus for the small scale generation of ammonia for industrial or agricultural uses.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The features and inventive aspects of the present invention will become more apparent upon reading the following detailed description, claims, and drawings, of which the following is a brief description.
[0015] FIG. 1 is a diagram of four components of the present invention.
[0016] FIG. 2 is a flow diagram of one embodiment of the present invention.
[0017] FIG. 3 is an example, without limitation, of one embodiment of the present invention usable on a motor vehicle.
[0018] FIG. 4 is a graph of operating pressure versus ammonia yield relating to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The present invention provides an alternative solution to the hazardous storage of ammonia through on-demand, load-following, or steady state synthesis of ammonia in a micro ammonia plant. Generated ammonia would immediately be used or stored in a non-hazardous state, as one example only, in a Temperature Swing Adsorption system using a zeolite. Embodiments of the invention comprise, without limitation, diesel and spark ignition motor vehicles, stationary and movable power generating sources, and other apparatus and processes where the controlled production of ammonia is desirable, as some examples only, the generation of ammonia-based fertilizers and in nitriding furnaces.
[0020] As shown in FIG. 1 , in one preferred embodiment, without limitation, the invention is comprised of:
1. at least one nitrogen generation source 10 ; 2. at least one hydrogen source 12 ; 3. at least one ammonia reactor 14 ; and 4. means for ammonia storage, such as an ammonia storage container 16 .
[0025] A mechanism for transporting the ammonia to an emissions system 18 is represented by dashed line 20 . As described more fully below, regulation of ammonia production is shown by line 22 .
[0026] As shown in the embodiment of FIG. 2 , without limitation, the nitrogen 10 and hydrogen 12 sources are connected with the ammonia reactor 14 , where ammonia is created and transferred to storage container 16 . The storage container 16 provides an ammonia source for use in the emissions system 18 . In such a system, transients or turn-downs are minimized, which is unique in storage systems and requires no user intervention.
[0027] As indicated in the embodiment of FIG. 2 , ammonia synthesis requires an accurate stoichiometric mixture of high purity hydrogen and nitrogen, which combine together at appropriate high temperature and pressure while in contact with a suitable catalyst, mixture of catalysts, or a series of different catalysts. The presence of catalyst allows the reaction to proceed at a higher rate and a significantly lower pressure and temperature than without catalyst, according to the following formula:
3H 2 +N 2 (in the presence of catalyst, high T, high P)=2NH 3 .
[0028] This is the rate limiting reaction.
[0029] The ammonia storage container 16 of the invention may be comprised of at least one zeolite source, which may be porous, with pore sizes created to a select a given molecular size, and shaped to hold and adsorb ammonia under normal operating conditions. The ammonia may be stored at ambient (e.g., 50 degrees C.) temperatures. Under use or demand conditions, the ammonia may be driven off from the storage system by controlled heating 24 of the catalyst.
[0030] In some embodiments, the invention comprises one or more storage sources for storage system 16 ( FIG. 3 ). In such embodiments, the invention may be operated through control systems (not shown) in order to select for the same or differential rates of charge or depletion of the individual storage sources, thus allowing the ammonia reactor 14 to be load-following or steady state, according to user-specified criteria.
[0031] In some embodiments, all catalysts are heated to appropriate operating temperature before becoming reactive. This permits operation in either a load-following state, for example, controlled by the engine output of NOx, or in a steady state of ammonia generation. Some embodiments comprise a control system (not shown) containing one or more algorithms that can be used to control or drive the ammonia reaction at peak conditions, for example, creating yield of the plant, with a variable speed motor in the compressor, and providing ammonia on demand.
[0032] In the present invention, ammonia may be synthesized from nitrogen, extracted from atmospheric air, and hydrogen, extracted from liquid or solid sources known to those of ordinary skill, such sources typically being significantly easier to monitor and control as compared to sources for high-pressure liquefied ammonia. In addition, both nitrogen and hydrogen could be, with the available technologies, generated only during the ammonia-making process. Consequently, in the period when ammonia is not manufactured, there would be no significant quantities of hydrogen or ammonia present in the system.
[0033] Nitrogen may be produced from a nitrogen source 10 such as atmospheric air according to one or more techniques know to those of ordinary skill in the art. One example involves a membrane separator ( FIG. 2 ), and another example involves a pressure swing absorption unit ( FIG. 2 ). Some embodiments of the invention may be comprised of at least one argon purge valve 8 to discharge argon and other contaminant gases accumulated in the system due to the use of air as a nitrogen source. Some embodiments may also be comprised of a circulator 9 which may be used to increase the efficiency and utilization of ammonia generated or stored in the invention.
[0034] The hydrogen source 12 may produce hydrogen for ammonia synthesis through one or more techniques including diesel fuel reforming and electrolysis, according to methods known to those of ordinary skill in the art. One downstream product of the SCR reaction is water, which, in some embodiments may be collected and circulated to the hydrogen source for use in hydrogen generation. Another source of water could come from condensing the water out of the exhaust stream and using that water for hydrogen generation. In some situations the water may need to be filtered to take out particulate matter or other undesirable species that would be inherent to condensed water from exhaust.
[0035] Ammonia reactors 14 of the invention are comprised of fluidized bed reactors made of iron oxide catalysts or other appropriate catalysts known to those of ordinary skill in the art. The invention may be comprised of one or more reactors 14 , which may be temperature-controlled in some embodiments. The size of the reactors 14 may be selected according to the anticipated peak ammonia demand.
[0036] One often cited prerequisite for successful ammonia synthesis is the high purity of the reacting gases under high pressure. A higher pressure within a reactor 14 results, for the same catalyst, in a higher yield of ammonia, but limitations exist to the pressure, depending on the applications the micro ammonia plant is being used, due to safety and cost issues.
[0037] The present invention takes advantage of the use of lower pressures which results in a lower yield of ammonia which is still suitable for reducing NOx in the exhaust stream. The invention permits ammonia generation at a modest pressure, where lower yield may be acceptable, for example and without limitation, at approximately 7% efficiency ( FIG. 4 ). At low yields, extra pumps can be used, and at high pressure, there may be low flow applications.
[0038] In some embodiments, the acceptance of a lower pressure range allows for the lower cost use of two or more compressors that would, as a group, have redundant capacity. By properly scheduling the running times of the compressors, one can prevent the unplanned interruption of the micro-plant operation caused by the compressor failure.
[0039] In some embodiments, in order to achieve the maximum reaction yield at lowered reaction pressures, the temperature in the catalytic reactor may be maintained at an optimum temperature through controls and heating or cooling system is maintained at the optimum. Maintenance of stable high temperature, or the ability to control the temperature within a narrow range, is an important requirement for performing the catalytic synthesis of ammonia in the mini plant, allowing steady yields and long, uninterrupted operation.
[0040] In addition, in order to avoid any runaway temperature excursions, the actual volume of the catalytic reactor can be divided in several segments that can be connected by simple tubular heat exchangers. In such an arrangement, the reaction mixture can be cooled down between reactor segments
[0041] One of the concerns for both safety and security is the quantity of the pure ammonia that can be released in the environment in the case of an accident. The present invention addresses this concern by two approaches:
A) The total quantity of ammonia that should be stored within the entire micro-plant should be kept at zero or at a minimum. If the ammonia storage is needed it should be sized to hold a supply of ammonia for the period of time that is necessary to start the micro-plant, and bring it up to the operating conditions; and B) The design of the storage for ammonia may be made to minimize the release of ammonia to the environment in case of an accidental breakage.
[0044] Although certain preferred embodiments of the present invention have been described, the invention is not limited to the illustrations described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention. A person of ordinary skill in the art will realize that certain modifications and variations will come within the teachings of this invention and that such variations and modifications are within its spirit and the scope as defined by the claims.
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The present invention comprises, without limitation, an on-board micro ammonia plant that offers a solution of NOx reduction without the hazards and inconvenience of carrying a secondary fluid on the vehicle. Thus, one embodiment of the present invention comprises a micro ammonia plant that controllably produces and stores ammonia that is used to reduce NOx levels in the exhaust streams of internal combustion engines.
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BACKGROUND OF THE INVENTION
[0001] This invention provides methods for the preparation of antibody fragment-targeted liposomes (“immunoliposomes”), including lipid-tagged antibody fragment-targeted liposomes, methods for in vitro transfection using the immunoliposomes, and methods for systemic gene delivery in vivo. The liposomes of the present invention are useful for carrying out targeted gene delivery and efficient gene expression after systemic administration. The specificity of the delivery system is derived from the targeting antibody fragments.
[0002] An ideal therapeutic for cancer would be one that selectively targets a cellular pathway responsible for the tumor phenotype and which is nontoxic to normal cells. While cancer treatments involving gene therapy have substantial promise, there are many issues that need to be addressed before this promise can be realized. Perhaps foremost among the issues associated with macromolecular treatments is the efficient delivery of the therapeutic molecules to the site(s) in the body where they are needed. A variety of delivery systems (a.k.a. “vectors”) have been tried including viruses and liposomes. The ideal delivery vehicle would be one that could be systemically (as opposed to locally) administered and which would thereafter selectively target tumor cells wherever they occur in the body.
[0003] The infectivity that makes viruses attractive as delivery vectors also poses their greatest drawback. Consequently, a significant amount of attention has been directed towards non-viral vectors for the delivery of molecular therapeutics. The liposome approach offers a number of advantages over viral methodologies for gene delivery. Most significantly, since liposomes are not infectious agents capable of self-replication, they pose no risk of transmission to other individuals. Targeting cancer cells via liposomes can be achieved by modifying the liposomes so that they selectively deliver their contents to tumor cells. There now exists a significant knowledge base regarding specific molecules that reside on the exterior surfaces of certain cancer cells. Such cell surface molecules can be used to target liposomes to tumor cells, because the molecules that reside upon the exterior of tumor cells differ from those on normal cells.
[0004] The publications and other materials used herein to illuminate die background of the invention or provide additional details respecting the practice, are incorporated by reference.
[0005] Current somatic gene therapy approaches employ either viral or non-viral vector systems. Many viral vectors allow high gene transfer efficiency but are deficient in certain areas (Ledley F D, et al. Hum. Gene Ther. (1995) 6:1129-1144). Non-viral gene transfer vectors circumvent some of the problems associated with using viral vectors. Progress has been made toward developing non-viral, pharmaceutical formulations of genes for in vivo human therapy, particularly cationic liposome-mediated gene transfer systems (Massing U, et al., Int. J. Clin. Pharmacol. Ther . (1997) 35:87-90). Features of cationic liposomes that make them versatile and attractive for DNA delivery include- simplicity of preparation; the ability to complex large amounts of DNA; versatility in use with any type and size of DNA or RNA; the ability to transfect many different types of cells, including non-dividing cells; and lack of immunogenicity or biohazardous activity (Felgner P L, et al., Ann. NY Acad. Sci. (1995) 772:126-139; Lewis J G, et al., Proc. Natl. Acad Sci. USA (1996) 93:3176-3181). More importantly from the perspective of human cancer therapy, cationic liposomes have been proven to be safe and efficient for in vivo gene delivery (Aoki K et al., Cancer Res. (1997) 55:3810-3816; Thierry A R, Proc. Natl. Acad. Sci. USA (1997) 92:9742-9746). More than thirty clinical trials are now underway using cationic liposomes for gene therapy (Zhang W et al., Adv. Pharmacology (1997) 32:289-333; RAC Committee Report: Human Gene Therapy Protocols-December 1998), and liposomes for delivery of small molecule therapeutics (e.g., antifungal and conventional chemotherapeutic agents) are already on the market (Allen T M, et al., Drugs (1997) 54 Suppl 4:8-14).
[0006] The transfection efficiency of cationic liposomes can be dramatically increased when they bear a ligand recognized by a cell surface receptor. Receptor-mediated endocytosis represents a highly efficient internalization pathway present in eukaryotic surface (Cristiano R J, et al., Cancer Gene Ther. (1996) 3:49-57, Cheng P W, Hum. Gene Ther . (1996) 7:275-282). The presence of a ligand on a liposome facilitates the entry of DNA into cells through initial binding of ligand by its receptor on the cell surface followed by internalization of the bound complex. A variety of ligands have been examined for their liposome-targeting ability, including transferrin and folate (Lee R J, et al., J. Biol. Chem . (1996) 271:8481-8487). Transferrin receptors (TfR) levels are elevated in various types of cancer cells including prostate cancers, even those prostate cell lines derived from human lymph node and bone metastases (Keer H N et al., J. Urol. (1990) 143:381-385); Chackal-Roy M et al., J. Clin. Invest. (1989) 84:43-50; Rossi M C, et al., Proc. Natl. Acad. Sci. USA (1992)89:6197-6201; Grayhack J T. et al., J. Urol. ( 1979)121:295-299). Elevated TfR levels also correlate with the aggressive or proliferative ability of tumor cells (Elliot R L, et al., Ann. NY Acad Sci. (1993) 698:159-166). Therefore, TfR levels are considered to be useful as a prognostic tumor marker, and TfR is a potential target for drug delivery in the therapy of malignant cells (Miyamoto T, et al., Int. J. Oral Maxillofac. Surg. (1994) 23:430-433:, Thorstensen K. et al., Scand. J. Clin. Lab. Invest. Suppl. (1993) 215:113-120). In our laboratory, we have prepared transferrin-complexed cationic liposomes with tumor cell transfection efficiencies in SCCHN of 60%-70%, as compared to only 5-20% by cationic liposomes without ligand (Xu L. et al., Hum. Gene Ther. (1997) 8:467-475).
[0007] In addition to the use of ligands that are recognized by receptors on tumor cells, specific antibodies can also be attached to the liposome surface (Allen T M et al., (1995) Stealth Liposomes, pp. 233-244) enabling them to be directed to specific tumor surface antigens (including but not limited to receptors) (Allen T M, Biochim. Biophys. Acta (1995) 1237:99-108). These “immunoliposomes,” especially the sterically stabilized immunoliposomes, can deliver therapeutic drugs to a specific target cell population (Allen T M, et al., (1995) Stealth Liposomes , pp. 233-244). Park, et al. (Park J W, et al., Proc. Natl. Acad Sci. USA (1995) 92:1327-1331) found that anti-HER-2 monoclonal antibody (Mab) Fab fragments conjugated to liposomes could bind specifically to HER-2 overexpressing breast cancer cell line SK-BR-3. The immunoliposomes were found to be internalized efficiently by receptor-mediated endocytosis via the coated pit pathway and also possibly by membrane fusion. Moreover, the anchoring of anti-HER-2 Fab fragments enhanced their inhibitory effects. Doxorubicin-loaded anti-HER-2 immunoliposomes also showed significant and specific cytotoxicity against target cells in vitro and in vivo (Park J W, et al., Proc. Natl. Acad. Sci. USA (1995) 92:1327-1331). In addition, Suzuki et al., (Suzuki S, et al., Br. J. Cancer (1997) 76:83-89) used an anti-transferrin receptor monoclonal antibody conjugated immunoliposome to deliver doxorubicin more effectively in human leukemia cells in vitro. Huwyler et al. (Huwyler J, et al., Proc. Natl. Acad. Sci. USA (1996) 93:14164-14169) used anti-TfR monoclonal antibody immunoliposome to deliver daunomycin to rat glioma (RT2) cells in vivo. This PEGylated immunoliposome resulted in a lower concentration of the drug in normal tissues and organs. These studies demonstrated the utility of immunoliposomes for tumor-targeting drug delivery. It should be noted that the immunoliposome complexes used by Suzuki et al. and Huwyler et al. differ from those of the invention described herein in that they are anionic liposomes and that the methods used by Suzuki et al. and Huwyler et al. are not capable of delivering nucleic acids.
[0000] Single-Chain Antibody Fragments
[0008] Progress in biotechnology has allowed the derivation of specific recognition domains from Mab (Poon R Y, (1997) Biotechnology International: International Developments in the Biotechnology Industry, pp. 113-128). The recombination of the variable regions of heavy and light chains and their integration into a single polypeptide provides the possibility of employing single-chain antibody derivatives (designated scFv) for targeting purposes. Retroviral vectors engineered to display scFv directed against carcinoembryonic antigen, HER-2, CD34, melanoma associated antigen and transferrin receptor have been developed (Jiang A, et al., J. Virol . (1998) 72:10148-10156, Konishi H, et al., Hum. Gene Ther. (1994) 9:235-248:, Martin F, et al., Hum. Gene Ther. (1998) 9:737-746). These scFv directed viruses have been shown to target, bind to and infect specifically the cell types expressing the particular antigen. Moreover, at least in the case of the carcinoembryonic antigen, scFv was shown to have the same cellular specificity as the parental antibody (Nicholson I C, Mol. Immunol. (1997) 34:1157-1165).
[0009] The combination of cationic liposome-gene transfer and immunoliposome techniques appears to be a promising system for targeted gene delivery.
SUMMARY OF THE INVENTION
[0010] We constructed a variety of immunoliposomes that are capable of tumor-targeted, systemic delivery of nucleic acids for use in human gene therapy. Based upon the data given in the Examples below these immunoliposome-DNA complexes incorporating the TfRscFv are capable of producing a much higher level of transfection efficiency than the same liposome-DNA complex bearing the complete Tf molecule. Therefore, in one aspect of the invention the immunoliposomes of the invention can be used to produce a kit for high efficiency transfection of various mammalian cell types that express the transferrin receptor. In one aspect of the invention, we constructed an scFv protein with a lipid tag such that the lipid is added naturally by the bacterial cell to allow easy incorporation of the scFv into liposomes while also avoiding chemical reactions which can inactivate the scFv.
[0011] The lipid-tagged scFv-immunoliposomes are prepared basically by two methods: a lipid-film solubilization method and a direct anchoring method. The lipid-film solubilization method is modified from the detergent dialysis method, which was described by Laukkanen M L, et al., (Laukkanen M L, et al., Biochemistry (1994) 33:11664-11670) and de Kruif et al., (de Kruif et al., FEBS Lett. (1996) 399:232-236) for neutral or anionic liposomes, with the methods of both hereby incorporated by reference. This method is suitable for attaching lipid-tagged scFv to cationic liposomes as well. In the lipid-film solubilization method, the lipids in chloroform are evaporated under reduced pressure to obtain a dry lipid film in a glass round-bottom flask. The lipid film is then solubilized with 0.54%, preferably 1%, n-octyl β-D-glucoside (OG) containing the lipid-modified scFv and vortexed. After dilution with sterile water, the solution is briefly sonicated to clarity.
[0012] The second method for attaching lipid-tagged antibodies or antibody fragments is the direct anchoring method that is specifically useful for attaching the E coli lipoprotein N-terminal 9 amino acids to an scFv (lpp-scFv) or other lipid-modified antibody or fragments and attaching these to preformed liposomes. For attaching the scFv to preformed liposomes, the lipid-modified scFv in 1% OG is added to preformed liposomes while vortexing, at volume ratios from 1:3 to 1:10. The mixture is vortexed for approximately a further 5-10 minutes to obtain a clear solution of scFv-immunoliposomes. The remaining OG and the uncomplexed scFv can be eliminated by chromatography, although they will not interfere very much with the subsequent usage. Separation experiments, i.e., ultrafiltration with Centricon-100 (Amicon), Ficoll-400 floatation (Shen D F, et al., Biochim. Biophys. Acta (1982) 689: 31-37), or Sepharose CL-4B (Pharmacia) chromatography, demonstrated that virtually all the lipid-tagged scFv molecules added have been attached or anchored to the cationic liposomes. This is an improvement over the much lower attachment rate of lpp-scFv to neutral or anionic liposomes. Therefore, this improvement makes it unnecessary to include a further purification step to remove the unattached scFv.
[0013] Any antibodies, antibody fragments, or other peptide/protein ligands that can be modified to have one or more lipid-tags on the surface are useful in the present invention. Other lipid-modification methods include directly conjugating a lipid chain to an antibody or fragment, as described in Liposome Technology, 2nd Ed., Gregoriadis, G., Ed., CRC Press, Boca Raton, Fla., 1992.
[0014] In another aspect of the invention a cysteine was added at the C-terminus of the scFv sequence and the protein was expressed in the inclusion bodies of E. coli, then refolded to produce active scFv. The C-terminal cysteine provided a free sulfhydryl group to facilitate the conjugation of the scFv to liposomes. There are two strategies which can be used in the conjugation process. 1) Pre-linking method: The first step is to conjugate the scFv-SH with the cationic liposome which contains a maleimidyl group or other sulfhydryl-reacting group, to make the scFv-liposome. The nucleic acids are then added to the scFv-liposome to form the scFv-liposome-DNA complex. The pre-linking is designated since scFv is linked before DNA complexing. 2) Post-linking method: This strategy is to complex the cationic liposome with nucleic acids first to form a condensed structure. The scFv-SH is then linked onto the surface of DNA-liposome complex to produce scFv-liposome-DNA. The post-linking is designated since scFv is linked after DNA complexing. The post-linking strategy ensures that 100% of scFv linked are on the surface of the complex, accessible to receptor binding. Therefore, this method can make a better use of the targeting ligand scFv and a better controlled inside structure of the complex.
[0015] The nucleic acid-immunoliposome complexes, regardless of whether the antibody or antibody fragment is lipid tagged or conjugated to the liposome, can be used therapeutically. Preferably the complexes are targeted to a site of interest, preferably to a cell which is a cancer cell, more preferably to a cell expressing a transferrin receptor. The targeting agent is the antibody or antibody fragment which preferably binds to a transferrin receptor. The nucleic acid is the therapeutic agent and is preferably a DNA molecule and more preferably encodes a wild type p53 molecule. The nucleic acid-immunoliposome complexes, preferably in a therapeutic composition, can be administered systemically, preferably intravenously.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 show scFv TfR lipid-tag construction.
[0017] FIG. 2 shows a Western blot analysis of scFv-liposome-targeted p53 expression in vivo in tumor xenografts with systemic administration.
[0018] FIG. 3 shows pCMVp53 and pCMVpRO constructs.
[0019] FIG. 4 shows p53-3′Ad construction.
[0020] FIG. 5 shows construction of scFvTfR-cysteine with a His tag.
[0021] FIG. 6 shows construction of scFvTfR-cysteine without a His tag. FIG. 7 shows construction of scFvTfR-cysteine with a cellulose binding domain (CBD) tag and with an S-tag.
[0022] FIG. 8 shows a Coomassie Blue stained SDS-polyacrylamide gel of purified TfRscFv protein produced by the conjugation method.
[0023] FIG. 9 shows a Western blot analysis of conjugation method produced TfRscFv-liposome-targeted p53 expression in vivo in tumor xenografts with systemic administration.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The invention is directed to immunoliposomes and methods of making and using these immunoliposomes. A variety of embodiments are disclosed including immunoliposomes with different tags and various methods with which to attach the scFv to the liposomes. The immunoliposomes may include lipid tags or be linked through a reducing group, which in a preferred embodiment is a free sulfhydryl.
[0025] Mutant forms of the tumor suppressor gene p53 have been associated with more than 50% of human cancers, including 15-50% of breast and 25-70% of metastatic prostate cancers. Abnormalities in p53 also correlate with poor prognosis in various types of malignancies. Therefore, the capability to systemically deliver and target gene therapy specifically to tumors to efficiently restore wtp53 function will be an important therapeutic modality in cancer treatment. Thus the immunoliposomes produced by the method of this invention will be useful as an effective new cancer therapeutic modality not just for restoration of wtp53 function but also as a tumor targeted systemic delivery vehicle for other therapeutic genes.
[0026] The invention is illustrated by the following Examples.
EXAMPLE 1
Construction and Expression of Biosynthetically Lipid-Tagged scFv
[0000] 1. Construction of the Expression Vector for TfRscFv
[0027] To construct the expression vector, we used the vector pLP1 which contains an amino acid linker sequence between the E. coli lipoprotein signal peptide (ssLPP) and the scFv cloning site (de Kruif et al., FEBS Lett . (1996) 399:232-236). This vector contains both c-myc and His 6 tag sequences that can be used for purification and detection of the expressed scFv ( FIG. 1 ).
[0028] We obtained a plasmid expression vector, pDFH2T-vecOK, which contains the single chain fragment for the 5E9 (Haynes et al., J. Immunol. (1981) 127:347-351) antibody linked to a DNA binding protein, which recognizes the human transferrin receptor (TfR). This vector also contains the sequence for a DNA binding protein, and there are no unique restriction enzyme sites flanking the scFv sequence in pDFH2T-vecOK. Therefore, we cloned the VH-linker-Vκ scFv by PCR amplification of the desired fragment using a 5′ primer (5′ GGCCCATGGAGGTGCAGCTGGTGG 3′ (SEQ ID NO:1)) (RB551) containing an NcoI site and a 3′ primer (RB552) (5′ CCGGAATTCGCGGCCGCTTTTATCTCCAGCTTGGTC 3′ (SEQ ID NO:2) containing a NotI site. The PCR amplification using primers RB551 and RB552 amplified the scFv for TfR from pDFH2T-vecOK from the Met at base 81 to Lys at base 821. The pLP1 vector also contains sequences for the E. coli lipoprotein signal peptide (ssLPP) and the E. coli lipoprotein N-terminal 9 amino acids (LPP), as described by Laukkanen M L, et al., (Laukkanen M L, et al., Biochemistry (1994) 33:11664-11670) and de Kruif et al (de Kruif et al., FEBS Lett. (1996) 399:232-236). The insertion of these sequences will lead to fatty acid acylation of the expressed signal in the E. coli host and its insertion into the bacterial membrane. The vector also has a non-critical 10 amino acid linker sequence to increase the space between the lipid-tag site and the scFv. Purification of the lipid modified scFv sequence from the bacterial membrane results in an active molecule that can be attached or inserted into liposomes.
[0000] 2. Expression and Purification of the TfRscFv
[0029] We transformed E. coli expression host SF110 F′ with the expression vector constructed above. While the host cell is not critical it is preferred that it contain expressed lac repressor. A number of clones were selected and the one that produces the best yield of scFv was chosen. The lipid-modified scFv (lpp-scFv) was isolated from the bacterial membrane using Triton X-100 as described by de Kruif et al., (de Kruif et al., FEBS Lett. (1996) 399:232-236). For purification a single colony was resuspended in 200 μl LB containing 5% glucose and the appropriate antibiotics. The mixture was plated onto two 90 mm LB agar plates containing 5% glucose and the appropriate antibiotics and grown overnight. The next day, the cells were washed from the plates and used to inoculate a total of 5 liters of LB containing 0.1% glucose and the appropriate antibiotics. The cultures were grown at 25° C., at 200 rpm for 6 hours until the OD 6000 reached 0.5 to 0.7. IPTG was added to a final concentration of 1 mM and the cultures were further incubated overnight. The next day, the bacterial cultures were collected by centrifugation and lysed in 200 ml lysis buffer at room temperature for 30 minutes. The sample was sonicated at 28 watts for 5 minutes with cooling on ice. The lysis buffer contains 20 mM HEPES pH 7.4 to 7.9, 0.5 M NaCl, 10% glycerol. and 0.1 mM PMSF. The only deviations from the cited protocol include washing and elution of metal affinity columns in buffer containing 20 mM HEPES pH 7.4 to 7.9, 0.5 M NaCl, 10% glycerol, 0.1 mM PMSF. 1% n-octyl β-D-glucoside (OG), and 10% glycerol containing 20 and 200 mM imidazole, respectively. The eluted samples of lpp-scFv were analyzed by SDS-PAGE and Westem Blot using anti-c-myc antibody 9E10 which confirmed that the purified scFv showed a band of the size of about 30 kDa.
EXAMPLE 2
Preparation of Lipid-Tagged scFv-Immunoliposomes by a Lipid-Film Solubilization Method
[0030] This example discloses a detailed procedure of lipid-film solubilization method to prepare lipid-tagged scFv-immunoliposomes. 5 μmol lipids (DOTAP/DOPE, 1:1 molar ratio) in chloroform are evaporated under reduced pressure to obtain a dry lipid film in a glass round-bottom flask. To the lipid film is added 0.5 ml 1% OG, 20 mM HEPES, 150 mM NaCl, pH 7.4, containing the lipid-modified scFv. This is incubated 10-20 minutes at room temperature and then vortexed to solubilize the lipid membrane. 2 ml sterile water is then added to dilute the scFv-lipid mixture. The solution is briefly sonicated to clarity in a bath-type sonicator at 20° C. The scFv-liposome is a clear solution with a limited amount of detergent OG left. The OG aid the uncomplexed scFv can be eliminated by chromatography with Sepharose CL-4B or Sephacryl S500, even though they do not interfere a lot with the subsequent use.
EXAMPLE 3
Preparation of Lipid-Tagged scFv-Immunoliposomes by a Direct Anchoring Method
[0031] This example provides a direct anchoring method to prepare lipid-tagged scFv-immunoliposomes. 20 μmol lipids (LipA-H, see below for compositions and ratios) prepared as dry lipid film in a glass round-bottom flask is added to 10 ml pure water and sonicated in a bath-type sonicator for 10-30 min at room temperature (LipA, B, C) or at 65° C. (LipD, E, G, H, or any composition with Cholesterol (Chol)). The cationic liposomes prepared are clear solutions, their compositions and ratios are as follows:
LipA DOTAP/DOPE 1:1 molar ratio LipB DDAB/DOPE 1:1 molar ratio LipC DDAB/DOPE 1:2 molar ratio LipD DOTAP/Chol 1:1 molar ratio LipE DDAB/Chol 1:1 molar ratio LipG DOTAP/DOPE/Chol 2:1:1 molar ratio LipH DDAB/DOPE/Chol 2:1:1 molar ratio
[0032] For attaching the scFv to preformed liposomes, the lipid-modified scFv (lpp-scFv) in 20 mM HEPES, 150 mM NaCl, pH 7.4, containing 1% OG is added to preformed liposomes while vortexing, at volume ratios from 1:3 to 1:10. The mixture is vortexed for a further 1 to 5 min to get a clear solution of scFv-immunoliposomes. The remaining OG and the uncomplexed scFv can be eliminated by chromatography although they do not interfere very much with the subsequent usage. Separation experiments, i.e., ultrafiltration with Centricon-100 (Amicon), Ficoll-400 floatation (Shen D F, et al., Biochim Biophys Acta (1982) 689:31-37), or Sepharose CL-4B (Pharmacia) chromatography, demonstrated that virtually all the lipid-tagged scFv added have been attached or anchored to the cationic liposomes. This is in contrast to the much lower attachment rate of lpp-scFv to neutral or anionic liposomes. Therefore, it is unnecessary to have a further purification step to get rid of the unattached scFv.
EXAMPLE 4
Immunoreactivity of Lipid-Tagged scFv-Immunoliposomes Revealed by ELISA, FACS and Immunofluorescence
[0033] This example provides the characterization of the anti-TfR scFv-immunoliposomes with respect to their ability of binding to the TfR(+) cells. The human prostate cancer cell line DU145 and the human squamous cell carcinoma of head and neck cell line JSQ-3 served as the TfR+ target cells for these studies.
[0034] Indirect cellular enzyme-linked immunosorbent assay (ELISA) was employed to determine the immunoreactivity of the lpp-scFv before and after attachment to liposomes. Confluent JSQ-3 cells in 96-well plates were fixed with 0.5% glutaraldehyde in PBS for 10 min at room temperature. The plate was blocked with 5% fetal bovine serum (FBS) in PBS at 30° C. for 30 min. The lpp-scFv, scFv-immunoliposomes and liposomes were added to wells in duplicate and incubated at 4° C. overnight. After three PBS-washes, an anti-c-myc monoclonal antibody was added to each well in 3% FBS in PBS and incubated at 37° C. for 60 min. After three PBS-washes, HRP-labeled goat-anti-mouse IgG (Sigma) diluted in 3% FBS was added to each well and incubated for 30 min at 37° C. The plate was washed three times with PBS and 100 μl substrate 0.4 mg/ml OPD in citrate phosphate buffer (Sigma) was added to each well. The color-development was stopped by adding 100 μl 2 M sulfuric acid to each well. The plate was read by an ELISA plate reader (Molecular Devices Corp.) at 490 nm. Indirect cellular ELISA demonstrated that the anti-TfR scFv retained its immunoreactivity after incorporation into the to liposome complex (Table 1).
TABLE 1 Binding of anti-TfR scFv-liposomes to JSQ-3 cells* Lip(A) only 0.142 ± 0.036 scFv-LipA1 1.134 ± 0.038 scFv-LipA2 1.386 ± 0.004 lpp-scFv 0.766 ± 0.009 *ELISA, OD 490 , Mean ± SD scFv-LipA1: by lipid-film solubilization method. scFv-LipA2: by direct anchoring method.
[0035] For FACS analysis, anti-TfR scFv-Lip(A), was incubated at 4° C. with JSQ-3 and DU145 cells, then with FITC-labeled sheep anti-mouse IgG, also at 4° C. Incubation of JSQ-3 cells with the scFv-Lip(A) resulted in a fluorescence shift identical to that observed with the unattached free anti-TfR lpp-scFv antibody demonstrating a significant amount of binding to the target cells. In contrast, the untargeted liposome demonstrated very low binding to the cells. Similar results were observed with prostate tumor cell line DU145. Here also, the scFv-Lip(A) complex demonstrated clear, substantial binding to the tumor cells as compared to the untargeted Lip(A). The FACS data is summarized in Table 2, where the fluorescence shift is indicated as the percent of the cells displaying fluorescence above the threshold level (percent of positive cells). In these studies also, the level of binding to the cells, represented by the percent of positive cells, was similar to that of the unattached free scFv further indicating that incorporation into the liposome complex did not inactivate the immunological activity of the anti-TfR lpp-scFv. It should be noted that the liposome preparation used for these initial experiments with DU145 was that optimized for JSQ-3 cells. Therefore, the binding of the scFv-targeted liposome complex to the prostate tumor cells can be further enhanced by the use of the liposome complex optimized for this cell type.
TABLE 2 FACS Analysis of TfRscFv-liposome Binding to JSQ-3 and DU145 JSQ-3 DU145 Transfected by % Positive Mean a % Positive Mean a Untransfected 3.46 4.07 2.22 3.40 Lip(A) 9.69 6.26 4.51 4.07 scFv-LipA1 86.38 19.8 50.19 12.40 scFv-LipA2 89.58 21.30 39.52 11.1 Free lpp-scFv 85.09 21.30 78.09 18.40 HB21 b 99.44 69.80 98.70 64.90 a Mean of the relative fluorescence b Parental monoclonal antibody of the anti-TfR scFv
[0036] Indirect immunofluorescence staining with scFv-liposome (where Lip(A) had been labeled with rhodamine-DOPE) and FITC-labeled anti-mouse IgG following anti-c-myc antibody, confirmed the binding of the scFv-targeted liposome complex to the JSQ-3 cells. The concurrence of the red and green fluorescence in the transfected cells demonstrates that the anti-TfR scFv (indicated by the FITC-labeled anti-c-myc antibody as green fluorescence) does indeed direct the rhodamine-labeled Lip(A) to the cells. Moreover, the high level of cellular binding of the scFv-Lip(A) system is demonstrated by the large percentage of red/green double-positive fluorescent cells.
EXAMPLE 5
Optimization of scFv-Immunoliposome Mediated Gene Transfection of Target Cells In Vitro
[0037] We determined the in vitro transfection efficiency of the anti-TfR scFv-Lip(A) complex in JSQ-3 cells using β-galactosidase as the reporter gene. In these studies the reporter construct used contained the β-galactosidase gene under the control of the CMV promoter (pCMVb), the same promoter used in pCMVp53 ( FIG. 3 ). The level of β-Gal expression in the transfected cells (correlating with the transfection efficiency) was assessed by β-Gal enzymatic assay (Xu L, et al., Hum. Gene Ther. (1997) 8:467-475). As shown in Table 3, the attachment of the anti-TfR scFv to the Lip(A) resulted in a doubling of the enzyme activity in the scFv-Lip(A)-pCMVb transfected cells, as compared to the untargeted liposome complex. This level of expression was also found to be virtually identical to that observed when transferrin itself was used as the targeting ligand (Tf-Lip(A)-pCMVb). Moreover, this increase in gene expression was shown to be reporter gene DNA dose dependent. Table 4 shows the optimization of scFv-liposome mediated transfection of JSQ-3 cells.
TABLE 3 Transfection of JSQ-3 Cells by Anti-TfR scFv-liposomes* DNA (μg/well) Lip(A) only Tf-Lip(A) scFV-LipA1 scFv-LipA2 1.0 475 1031 997 1221 0.5 601 981 811 854 0.25 266 503 578 471 0.125 130 262 215 236 *milliunits/mg protein, β-galactosidase equivalent, β-Gal enzymatic assay scFv-LipA1: by lipid-film solubilization method scFv-LipA2: by direct anchoring method
[0038]
TABLE 4
Optimization of scFv-liposome transfection to JSQ-3*
DNA/Lip
Lip(A)
scFv-
scFv-
scFv-
scFv-
sFv-
(μg/nmol)
only
LipA1
LipA2
LipB
LipD
LipG
⅛
1.559
2.793
2.642
1.827
0.874
0.648
1/10
1.776
2.846
2.83
2.268
1.606
1.283
1/12
1.868
2.772
2.815
2.175
1.257
1.416
1/14
1.451
3.031
2.797
2.31
1.78
1.656
*β-Gal enzymatic assay, OD 405
scFv-LipA1: by lipid-film solubilization method
scFv-LipA2: by direct anchoring method
EXAMPLE 6
scFv-Immunoliposome Mediated p53 Gene Transfection Target to Tumor Cells Causing Sensitization to Chemotherapeutic Agents
[0000] 1. Anti-TfR scFv Facilitated Liposome-Mediated wtp53 Gene Transfection In Vitro
[0039] The expression of exogenous wtp53 in JSQ-3 tumor cells transfected with the anti-TfR scFv-targeted Lip(A)-p53-3!Ad was assessed by co-transfection of an expression plasmid (pBP100) which contains the luciferase reporter gene under the control of a p53 responsive promoter (Chen L, et al., Proc. Natl. Acad. Sci. USA (1998) 95:195-200). Consequently, the higher the level of exogenous wt p53 expression (representing the scFv-Lip(A)-p53-3′Ad transfection efficiency), the higher the level of luciferase activity. This luciferase enzyme activity is expressed as relative light units (RLU). As was demonstrated above with the β-gal reporter gene, the addition of the anti-TfR scFv as the targeting agent to the Lip(A)-p53-3′Ad complex resulted in a significant increase in transfection efficiency and wtp53 protein expression (as expressed by RLU of Luciferase activity) over the untargeted Lip(A)-p53-3′Ad complex (Table 5). Once again, the level of p53 expression in the scFv-Lip(A)-p53-3′Ad transfected cells was similar to that observed when transferrin itself was used as the targeting ligand (LipT(A)-p53-3′Ad). Therefore these findings indicate that the anti-TfR single-chain antibody strategy is a useful method of targeting the cationic liposome complex, and delivering a biologically active wtp53 gene, to tumor cells.
TABLE 5 In Vitro p53 Expression Mediated by Different Liposomes in JSQ-3 cells Transfected by RLU* Medium + p53-3′Ad + pBP100 158 Lip(A) + p53-3′Ad + pBP100 4073 LipT(A) + p53-3′Ad + pBP100 7566 scFv-Lip(A1) + p53-3′Ad + pBP100 6441 *Relative light units per well
2. Anti-TfR scFv-Immunoliposome Mediated p53 Gene Restoration sensitized the Tumor Cells to the Cytotoxicity of Cisplatin (CDDP).
[0040] For the p53-induced apoptosis study, mouse melanoma cell line B16 was transfected with anti-TfR scFv-immunoliposome complexed with p53-3′Ad ( FIG. 4 ) or pCMVpRo plasmid ( FIG. 3 ) DNA (scFv-Lip(A)-p53 and scFv-Lip(A)-pRo, respectively) at a dose of 5 μg DNA/2×10 5 cells in 2 sets of 6-well plates. For comparison, transferrin-liposome-DNA (LipT-p53 or LipT-pRo) were also transfected at a dose of 5 μg DNA/2×10 5 cells. 24 hours later, CDDP was added to one set of plates to 10 μM final concentration. 24 and 48 hours after the drug was added, both the attached and floating cells were collected for apoptosis staining. The cells were stained with an Annexin V-FITC Kit (Trevigen, Inc., Gaithersburg, Md.) according to manufacturer's protocol. Annexin V is a lipocortin, a naturally occurring blood protein and anti-coagulant. The stained cells were analyzed on a FACStar cytometer (Becton and Dickinson). Table 6 summarizes the results of the apoptosis analysis.
TABLE 6 Apoptosis of B16 Cells Induced by Liposomal p53-gene Restoration and CDDP* 24 hours 48 hours Transfected by −CDDP +CDDP −CDDP +CDDP Untransfected 0.22 4.4 6.33 20.11 LipA-p53 15.9 26.7 15.02 26.52 scFv-LipA-p53 13.9 38.4 34.94 43.7 scFv-LipA-pRo 8.1 19.9 24.14 37.59 Tf-LipA-p53 22.4 29.5 34.47 31.7 Tf-LipA-pRo 14.1 12.6 14.00 25.34 *% of apoptotic cells (Annexin V-FITC positive)
[0041] Without CDDP there was no increase in the percent of apoptotic cells induced at 24 hours by the addition of the scFv ligand as compared to the amount induced by the liposome complex alone. However, by 48 hours, there is a greater than 2-fold increase in the percent of apoptotic cells by the addition of the targeting scFv to the lipoplex. With CDDP there is a significant increase in apoptotic cells (approximately 1.5-fold) even at 24 hours as compared to the untargeted liposome complex. More significantly, this increase in apoptotic cells in combination with CDDP is more pronounced using the scFv to the Tf receptor as the targeting ligand than using the Tf molecule itself This increase correlates with transfection efficiency.
EXAMPLE 7
scFv-Immunoliposome-Targeted wtp53 Gene Delivery and Expression In Vivo with Systemic Administration
[0042] To examine the ability of the anti-TfR scFv containing liposomes to deliver wtp53 specifically to tumor tissue in vivo, scFv-Lip(A)-p53-3′Ad ( FIG. 4 ) or the untargeted Lip(A)-p53-3′Ad ( FIG. 4 ) was injected intravenously into nude mice bearing JSQ-3 subcutaneous xenograft tumors. Two days after injection, the tumors were excised and protein isolated from liver and skin, as well as the tumor, for Western blot analysis (Xu L, et al., Hum. Gene Ther. (1997) 8:467-475). Equal amounts of protein (100 μg, as determined by concentration) were loaded in each lane. As shown in FIG. 2 , the tumor from the mouse systemically treated with the scFv-Lip(A)-p53-3′Ad complex, labeled scFv-Lip(A)-p53 in FIG. 2 , displayed a very intense p53 signal as well as the additional lower band indicative of a high level of expression of the exogenous wtp53, while only the lower expression of the endogenous mouse p53 is evident in both the skin and the liver. In contrast, as would be expected based upon our earlier results, a significantly lower level of exogenous p53 expression is evident in the tumor isolated from the untargeted Lip(A)-p53-3′Ad injected mouse, labeled Lip(A)-p53 in FIG. 2 . Therefore, the liposome complex targeted by our new and unique anti-TfR lpp-scFv ligand can clearly deliver exogenous genes selectively to the tumor in vivo. These results demonstrate the potential of this new way of efficiently targeting systemically delivered, cationic liposome complexes specifically to tumors in vivo.
EXAMPLE 8
Construction and Purification of TfRscFv with a 3′ Cysteine for Use in the Conjugation Method
[0043] In the absence of a lipid tag, another method was devised to attach the purified TfRscFv protein to the lipoplex. This approach entails the conjugation of the single chain protein to cationic liposomes via a reducible group such as a sulfhydryl group. In the preferred embodiment a cysteine residue is added at the 3′ end of the TfRscFv protein. Reduction of this cysteine results in a free sulfhydryl group which is capable of being conjugated to cationic liposomes, thus targeting the lipoplex to cells expressing the transferrin receptor. While the following examples use cysteine as the reducible group it is obvious that other similar reducing groups would also work with this method.
[0000] 1. Construction
[0000] A. Construction of an Expression Vector Containing a 3′ Cysteine with a Histidine Tag for Use in the Conjugation Method of Producing TfRscFv Immunoliposomes
[0044] As in Example 1, the VH-linker-Vκ scFv for the TfR was obtained from plasmid expression vector, pDFH2T-vecOK (described in Example 1). Using a 5′ primer (5′ GGCCCATGGAGGTGC AGCTGGTGG 3′ (SEQ ID NO:3)) for PCR amplification, an NcoI site was introduced into pDFH2T-vecOK. The nucleotide sequence for the cysteine residue as well as a NotI restriction site was introduced using a 3′ primer (5′ GGCGCGGCCGCGCATTTTATCTCCAGCTTG 3′ (SEQ ID NO:4)). The PCR product was cloned into NcoI and NotI sites of the commercial vector pET26b(+) (Novagen). This vector also contains, 5′ of the NcoI site, the pelB leader signal sequence. The presence of this sequence in the expression vector allows transport of the protein to the periplasmic space. To aid in purification of the protein, the pET26b(+) vector also contains a Histidine tag sequence 3′ of the NotI site ( FIG. 5 ).
[0000] B. Construction of an Expression Vector Containing a 3′ Cysteine without a Histidine Tag for Use in the Conjugation Method of Producing TfRscFv Immunoliposomes
[0045] For human use as a therapeutic delivery vehicle, it is preferable that the TfRscFv be produced without the Histidine tag. Therefore, the construct described in Example 8, section 1. A, was modified to eliminate this tag in the final protein product. To accomplish this, the same 5′ primer as described above (in Example 8, section 1. A) was used. However, a different 3′ primer was used. In addition to the nucleotide sequence for the cysteine residue and the NotI restriction site, this primer (5′GGCGCGGCCGCTCAGCATTTTATCTCCAGCTTG 3′ (SEQ ID NO:5)), introduced a DNA stop codon adjacent to the cysteine sequence and before the NotI site ( FIG. 6 ). Thus, the protein product of this construct will not contain the His-tag.
[0000] C. Construction of an Expression Vector Containing a 3′ Cysteine with a 5′ CBD™-Tag for Use in the Conjugation Method of Producing TfRscFv Immunoliposomes
[0046] A third alternative construct containing a cysteine residue for linkage to the cationic lipoplex using the conjugation method was also made. For this construct ( FIG. 7 ), the same two primers described above in Example 8, section 1 B, were used. Thus no His-tag would be present in the protein product. However, the PCR product of these reactions was cloned into a different vector, pET37b(+) (Novagen). This vector contains a cellulose binding domain tag (CBD™-tag) and an S-tag, both 5′ of the NcoI site in the vector. The CBD-tag sequence encodes a cellulose binding domain derived from a microbial cellulase. Thus, the presence of this tag enables the use of cellulose-based supports for highly specific, low cost affinity purification of the protein product. The presence of the S-tag present in this construct allows for easy detection of the protein product on Western blots and for easy enzymatic quantitation of protein amounts.
[0000] 2. Purification of the TfRscFv Containing the Cysteine Residue
[0047] The commercially available E. coli expression host BL21(DE3), which contains the expressed lac repressor, was transformed with an expression vector (all three were used individually) described above in Example 8, section 1. A number of clones were selected and the ones that produced the best yield of TfRscFv were chosen. Purification of the protein from the construct described above in Example 8. section 1. A, with the histidine tag is given in detail as an example, although the same method is used for purification of the cysteine containing TfRscFv protein from all three constructs described in Example 8, section 1. The majority of the TfRscFv protein (approximately 90%) was found not to be soluble but to be contained within the inclusion bodies. Therefore, the TfRscFv containing the cysteine-linker was purified from the inclusion bodies as follows. A single clone was inoculated into 5-10 ml LB containing 50 μg/ml Kanamycin, and grown at 37° C., and 250 rpm to an OD 600 of 0.5-0.7 (4-5 hrs). 30 ml of the mini culture was pelleted, suspended in LB broth, added to 1 L LB containing 50 μg/ml Kanamycin and incubated at 37° C. and 250 rpm, to an OD 600 of 0.5-0.7 (4-5 hrs). To induce expression of the TfRscFv protein, IPTG at a final concentration of 1 mM was added to the culture at this time and incubation continued for an additional 4 hrs. This time was determined to yield the maximum level of protein expression. The bacterial cultures were then collected by centrifugation and lysed in 100 ml of cold 20 mM Tris-HCl, pH 7.5, containing 100 μg/ml lysozyme, at 30° C. for 15 minutes. The sample was sonicated at 1 0 watts for 5 minutes (in 30 second bursts) with cooling on ice. The inclusion bodies were isolated by centrifugation at 13,000 g for 15 minutes. The resulting pellet was washed three times in cold 20 mM Tris-HCl buffer, pH 7.5. The purity and quantity of the inclusion bodies were determined by SDS-polyacrylamide gel electrophoresis before solubilization.
[0048] The isolated inclusion bodies were dissolved in 100 mM Tris-HCl, pH 8.0 containing 6 M guanidine-HCl and 200 mM NaCl (6 M GuHCl buffer) and centrifuged at 12,300 g for 15 minutes to remove insoluble debris. 2-mercaptoethanol was added to the supernatant to a final concentration equal to approximately 50 molar fold of the protein concentration and the mixture incubated with rotation for 1 hour at room temperature. The presence of such a high concentration of guanidine-HCl and the reducing agent results in a totally unfolded protein. Refolding of the TfRscFv protein was accomplished by dialysis at 4° C. against decreasing concentrations of guanidine-HCl in the absence of 2-mercaptoethanol: Dialysis was performed for 24 hours each against the following concentrations of guanidine-HCl in 100 mM Tris-HCl, pH 8.0 and 200 mM NaCl: 6 M, 3 M, 2 M, 1 M and 0.5 M. The last dialysis was against three changes of just 100 mM Tris-HCl, pH 8.0 and 200 mM NaCl. The fourth dialysis solution (of 1 M guanidine-HCl) also contained 2 mM glutathione (oxidized form) and 500 mM L-arginine. These reagents allow the partially refolded protein to form the proper disulfide bonds to produce the correct protein conformation. The solution was clarified by centrifugation at 13000 g to remove aggregates. The sample was concentrated approximately 1.5 fold using the Centrplus centrifugal filter (Amicon) at 3000 g for 90 min. SDS-PAGE showed a single band of the solubilized cysteine containing TfRscFv with a molecular weight of approximately 28-30 kDa containing only minor contaminants ( FIG. 8 ).
EXAMPLE 9
Preparation of scFv-Liposomes by the Conjugation Method
[0000] 1. Reduction of scFv
[0049] The purified TfRscFv was reduced by DTT to obtain monomer scFv-SH as follows: To scFv in HBS (10 mM HEPES, 150 mM NaCl, pH 7.4) was added 1 M DTT to a final concentration of 1-50 mM. After rotation at room temperature for 5-10 min, the protein was desalted on a 10-DG column (Bio-Rad). The free —SH group was measured by 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB, Ellman's reagent) (G. L. Ellman (1959) Arch. Biochem. Biophys. 82:70-77. P. W. Riddles, R. L. Blakeley, B. Zeruer (1993) Methods Enzymol. 91:49-60) and calculated as —SH/protein molar ratio, or number of free —SH per scFv molecule (Table 7). The results indicate that 1-10 mM DTT is appropriate for the scFv reduction.
TABLE 7 Reduction of TfRscFv DTT Concentration (mM) -SH/scFv molar ratio 0 0.15 1 0.45 10 1.94 20 2.26 50 3.03
2. Liposome Preparation
[0050] 4-(p-maleimidophenyl)butyrate-DOPE (MPB-DOPE) (Avanti Polar Lipids) is included in the seven liposome formulations described in Example 3, to a 5-8% molar of total lipids. The MPB-liposomes were prepared the same way as described in Example 3. Other liposome preparation methods can also be used to prepare the cationic liposomes. For example, the ethanol injection method modified form that described by Campbell M J ( Biotechniques June 1995; 18(6):1027-32) was used successfully in the present invention. In brief, all lipids were solubilized in ethanol and mixed, injected into vortexing pure water of 50-60° C. with a Hamilton syringe. The solution was vortexed for a further 10-15 min. The final concentration was 1-2 mM total lipids. The ethanol injection method is faster, easier and more robust. 1 M HEPES, pH 7.5 (pH 7.0-8.0) was added to a final concentration of 10-20 mM. Since we have found that the maleimide group is not stable in aqueous solution with pH>7, the liposomes should be prepared in water (pH 5-6.5). The pH can be adjusted to 7.0-8.0 before linking to scFv-SH with 1 M HEPES buffer, pH 7.0-8.0. to facilitate the post-coating reaction.
[0000] 3. Preparation of scFv-Liposome-DNA Complexes
[0051] A. Pre-Linking Method
[0052] scFv-SH was added to MPB-liposome at a protein/lipid (w/w) ratio of 1/5-1/40, preferably 1/10-1/20. The solution was mixed by gentle rotation for 30 min at room temperature to yield scFv-Lip. The scFv-Lip was used without purification although it can be purified by Sepharose CL-4B column chromatography. Plasmid DNA was diluted in water and added to the scFv-Lip at a DNA/lipid (μg/nmol) ratio of 1/6-1/20, preferably 1/10-1/14. The solution was mixed well for 5-15 min by inversion several times to produce scFv-Lip-DNA complex. scFv-Lip-DNA was used without purification although it can be purified by Sepharose CL-4B column chromatography. 80-100% of the scFv was found to be conjugated to the liposome.
[0053] B. Post-linking Method
[0054] Plasmid DNA was diluted in water and was added to the MPB-liposome at a DNA/lipid (μg/nmol) ratio of 1/6-1/20, preferably 1/10-1/14. The solution was mixed well for 5-15 min by inversion several times to produce an MPB-Lip-DNA complex. scFv-SH was then added to the complex at a protein/lipid (w/w) ratio of 1/5-1/40, preferably 1/10-1/20. The solution was mixed by gentle rotation for 30 min at room temperature, to produce the final scFv-Lip-DNA complex. The scFv-Lip-DNA was used without purification although it can be purified by Sepharose CL-4B column chromatography. 80-100% of the scFv was found to be conjugated to the liposome. 4. For intravenous injection, a 50% dextrose solution was added to the scFv-Lip-DNA to a final concentration of 5%.
EXAMPLE 10
Immunoreactivity of Cysteine Containing TfRscFv-Immunoliposomes by the ELISA Assay
[0055] This example provides the characterization of the anti-TfRscFv-immunoliposomes produced by the conjugation method of this invention with respect to their ability to bind to TfR(+) cells in vitro. Human squamous cell carcinoma of head and neck cell line JSQ-3 served as the TfR(+) target cells for these studies.
[0056] As previously described in Example 4, indirect cellular enzyme-linked immunosorbent assay (ELISA) was employed to determine the immunoreactivity of the TfRscFv before and after conjugation to liposomes. Confluent JSQ-3 cells in 96-well plates were fixed with 0.5% glutaraldehyde in PBS for 10 min at room temperature. The plate was blocked with 5% fetal bovine serum (FBS) in PBS at 30° C. for 30 min. The cysteine containing TfRscFv alone, this TfRscFv conjugated to cationic liposomes (TfRscFv-immunoliposomes) and untargeted liposomes were added to wells in triplicate. An anti-transferrin receptor monoclonal antibody (Hb21, obtained from David Fitzgerald, NIH) was used in one series of wells as a positive control. The plate was incubated at 4° C. overnight. The wells were washed three times with PBS, and an anti-His monoclonal antibody (Qiagen) was added to each well (except for those receiving the antibody positive control) in 3% FBS in PBS and incubated at 37° C. for 60 min. After three PBS washes, HRP-labeled goat-anti-mouse IgG (Sigma) diluted in 3% FBS was added to each well and incubated for 30 min at 37° C. The plate was washed three times with PBS and 100 μl substrate 0.4 mg/ml OPD in citrate phosphate buffer (Sigma) was added to each well. The color-development was stopped by adding 100 μl 2 M sulfuric acid to each well. The plate was read on an ELISA plate reader (Molecular Devices Corp.) at 490 nm.
[0057] Indirect cellular ELISA clearly demonstrated that the anti-TfR scFv containing a C-terminal cysteine maintained its immunoreactivity. The OD 490 values increased with increasing amounts of TfRscFv protein, rising from 0.060±0.0035 with 0.6 μg of protein, to 0.100±0.0038 at 1.5 μg and 0.132±0.0031 with 3 μg of TfRscFv. Moreover, this TfRscFv protein appears to have even greater binding activity than the parental Hb21 anti-transferrin receptor antibody used as a positive control. The OD 490 for the highest concentration of the Hb21 (100 μl) was approximately 2-4 fold less (0.033±0.0086).
[0058] The indirect cellular ELISA assay was also performed after the same TfRscFv protein was incorporated via the conjugation method of the invention (Example 9) into two different liposome complexes (Lip(A) and Lip(B)) to demonstrate the universality of this method with cationic liposomes. Both the pre- and post-linking conjugation methods of liposome preparation detailed in Example 9 were used. As shown in Table 8, the immunoreactivity of the TfRscFv prepared by the conjugation method is not lost through complexing to either of the two liposome compositions. This was true for both pre- and post-linking methods used to produce the immunoliposome complex. The TfRscFv-targeted lipoplexes also demonstrated binding to the cells. This binding was significantly higher than that of the liposome without the TfRscFv, suggesting that this binding is in fact mediated through the attachment of the TfRscFv to the transferrin receptor on the cells.
TABLE 8 Binding of TfRscFv-immunoliposomes Prepared by the Conjugation Method to JSQ-3 Cells In Vitro* DNA:Lipid Ratio OD 490 Lip(B)-DNA 1:10 0.088 TfRscFv-Lip(A)-DNA by Pre- 1:10 0.152 ± 0.016 TfRscFv-Lip(A)-DNA by Pre- 1:12 0.166 ± 0.009 TfRscFv-Lip(A)-DNA by Post- 1:12 0.168 ± 0.006 TfRscFv-Lip(B)-DNA by Pre- 1:12 0.139 ± 0.012 TfRscFv only — 0.235 *ELISA, OD 490 , Mean ± SD (triplicate readings except for Lip(B)-DNA) Pre- = Pre-linking Conjugation Method Post- = Post-linking Conjugation Method
EXAMPLE 11
Conjugated TfRscFv-Immunoliposome Mediated Gene Transfection of Target Cells In Vitro
[0059] We determined the in vitro transfection efficiency of the TfRscFv-liposome complex, prepared by the conjugation method, in cells using the plasmid pLuc, which contains the firefly luciferase gene under control of the CMV promoter as the reporter gene. To demonstrate the universality of the TfRscFv as a targeting ligand, here also, as in Example 10, two separate liposome compositions (Lip(A) and Lip(B)) were conjugated to the TfRscFv protein. Human breast cancer cell line MDA-MB-435 and human squamous cell carcinoma of the head and neck cell line JSQ-3 were used in these studies. The in vitro transfection was performed in 24-well plates (Xu L, et al., Atom. Gene Ther. (1999) 10:2941-2952). The transfection solutions were added to the cells in the presence of 10% serum. 24 hr later the cells were washed and lysed to measure the luciferase activity and protein concentration. The results are expressed as 10 3 relative light units (RLU) per μg protein in the lysate, as shown in Tables 9A and 9B.
TABLE 9A Conjugated TfRscFv-immunoliposome Mediated Transfection In Vitro # Luciferase Activity (×10 3 RLU/μg protein) MDA-MB-435 JSQ-3 LipA 106 377 Tf-LipA 284 640 scFv-LipA* 560 1160 scFv-LipA** 660 1210 scFv-LipA (1/10) @ — 1315 scFv-LipA (1/20) @ — 751 # Mean of duplicates *Containing 5% MPB-DOPE **Containing 7% MPB-DOPE @ Ratio of scFv/lipids (w/w)
[0060]
TABLE 9B
In Vitro Transfection Activity of Conjugated
TfRscFv-Immunoliposome-DNA Complexes
Prepared for Systemic Administration
Luciferase Activity
(×10 3 RLU/μg protein)
MDA-MB-435
JSQ-3
scFv-LipA-pLuc (pre-linking)*
58.4
675
scFv-LipA-pLuc (pre-linking)**
45.6
513
scFv-LipB-pLuc (pre-linking)*
51.4
415
scFv-LipA-pLuc (post-linking)*
58.1
856
scFv-LipA-pLuc (post-linking)**
45.3
343
scFv-LipB-pLuc (post-linking)*
47.2
237
*Containing 5% MPB-DOPE
**Containing 7% MPB-DOPE
[0061] The results show that the cysteine containing TfRscFv-immunoliposomes prepared by the conjugation method have very high transfection activity in vitro. 3-6 fold higher than the untargeted liposomes and 2-3 fold higher than the transferrin-targeted liposomes. This was true for both liposome compositions and both human tumor cell lines. Thus, they still retain their immunoreactivity and can bind to their target receptor. Based upon Table 9A, the scFv-liposomes can also be used as efficient gene transfection reagents in vitro and are much more efficient than commercially available cationic liposomes (DOTAP/DOPE and DDAB/DOPE) and transferrin-liposomes. The TfRscFv-immunoliposomes disclosed in the present invention can be used for an efficient in vitro gene transfection kit useful for the transfection of mammalian cells with transferrin receptors.
[0062] The TfRscFv is a smaller molecule than transferrin itself. Thus, the resulting complex is more compact and more easily taken up by the cells giving a higher transfection efficiency. These results are also advantageous for the use of the TfRscFv immunoliposome for systemic delivery for human use. The smaller size allows increased access to the tumor cells through the small capillaries. Most significantly, the TfRscFv is not a human blood product as is the Tf molecule. Therefore, the concerns and technical problems associated with the use of transferrin itself for human therapy are avoided.
EXAMPLE 12
Conjugated TfRscFv-Immunoliposome Mediated Expression of Wild-Type p53 in a Nude Mouse Xenograft Model Following Systemic Delivery
[0063] In this example the ability of the TfRscFv, produced by the conjugation method of this invention, to direct a lipoplex carrying the wild-type p53 (wtp53) gene preferentially to tumor cells in vivo after systemic delivery is demonstrated. To demonstrate the universality of the TfRscFv as a targeting ligand, here also, as in Example 10, two separate liposome compositions (Lip(A) and Lip(B)) were complexed to the cysteine-containing TfRscFv protein by the conjugation method. Only the pre-linking method of conjugation as detailed in Example 9 was used in this study. 2.5×10 6 MDA-MB-435 human breast cancer cells were subcutaneously injected into 4-6 wk old female athymic nude mice. 1.1×10 7 DU145 human prostate cancer cells suspended in Matrigel® collagen basement membrane (Collaborative Biomedical Products) were also subcutaneously injected into 4-6 week old female athymic nude mice and tumors were allowed to develop. Animals bearing tumors of between 50-200 mm 3 were used in the study (1 animal/sample tested). Conjugated TfRscFv immunoliposomes carrying the wtp53 gene, as well as untargeted Lip(B)-p53 and wtp53 naked DNA were intravenously injected into the tail vein of the animals. As an additional control, conjugated TfRscFv-Lip(A) carrying the empty vector in place of the p53 containing vector was also injected into a mouse. As described in Example 7, approximately 60 hours post-injection, the animals were sacrificed and the tumors, as well as the liver, were excised. Protein was isolated from the tissues and 100 μg of each sample (as determined by protein concentration assay) was run on a 10% polyacrylamide gel for Western blot analysis using an anti-p53 monoclonal antibody. In both of these tumor types the endogenous mouse and the exogenous human p53 migrate at the same position. The results here mirror those described in Example 7. As shown in FIG. 9 , both the DU145 and MDA-MB-435 tumors from the animals intravenously injected with the TfRscFv-Lip(A)-pCMVp53 lipoplex or the TfRscFv-Lip(B)-pCMVp53 lipoplex prepared by the conjugation method displayed a high level of expression of exogenous wtp53, as indicated by the intense p53 signal and an additional lower band, with the best expression in the DU145 tumors. While it appears that in both tumor types the Lip(A) composition was somewhat better than the Lip(B), both liposome compositions worked demonstrating the universality of this method. Only the endogenous mouse p53 protein was evident in the liver of these animals. In contrast, only the endogenous mouse p53 protein was evident in the tumors excised from the mice injected with the conjugated TfRscFv-Lip(B) carrying the empty vector or the naked wtp53 DNA. A small increase in p53 expression also was observed in the DU145 tumor with the untargeted Lip(B)-p53. Thus, the conjugated TfRscFv-immunoliposomes delivered the wtp53 gene preferentially to the tumors, as desired. It is also significant that this tumor targeting was evident in two different tumor types, indicating the general usefulness of the method of this invention. Therefore, the methods of this invention described in the preceding Examples generate a TfRscFv protein that not only retains its ability to bind to cationic liposomes but is still immunologically active preserving its ability to bind to the transferrin receptor in vitro and in vivo, thus fulfilling our objective of producing a tumor-specific, targeted immunoliposome for gene therapy.
[0064] While the invention has been disclosed in this patent application by reference to the details of preferred embodiments of the invention, it is to be understood that the disclosure is intended in an illustrative rather than in a limiting sense, as it is contemplated that modifications will readily occur to those skilled in the art, within the spirit of the invention and the scope of the appended claims.
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A targeted vector allowing enhanced gene transfer to human hepato-cellular carcinoma (HCC 1 ) cells in vitro was developed using cationic liposomes covalently conjugated with the mAb AF-20. This high affinity antibody recognizes a rapidly internalized 180 kDa cell surface glycoprotein which is abundantly expressed on the surface of human HCC and other cancer cells. Quantitative binding analysis of liposomes with target cells by flow cytometry showed specific association of mAb-targeted liposomes with human HCC cells. Using mAb-targeted cationic liposomes containing 20% DOTAP, in the presence or absence of serum, gene expression in HuH-7 cells was enhanced up to 40-fold as compared to liposomes conjugated with an isotype-matched non-relevant control antibody. Transfection specificity was not observed in a control cell line that does not express the antigen recognized by mAb AF-20. This study demonstrates that cationic liposome foormulations can be targeted with monclonal antibodies (mAbs) to enhance specific in vitro gene delivery and expression in the presence or absence of serum.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally for drill bits and cutters used downhole in oil, gas or other type wells and particularly to cutters and drill bits for the removal of obstructions jammed in the casings of such wells.
2. Brief Description of the Prior Art
Well packers have, on occasion, been known to jam within the casing of oil and gas wells. When this occurs, there has been no practical means for removing the packer from the casing. Attempts to drill out or through the jammed packer with conventional drill bits have proved unsuccessful. Typically, the debris created by the drilling operation becomes jammed between the drill bit and the casing. The net result is that the drilling operation cannot be continued and often, the drill bit itself also becomes jammed within the well and is lost. When a packer becomes jammed in the casing of an oil or gas well and cannot be removed, the well is lost.
U.S. Pat. No. 2,663,546 to Kammerer is a conventional drill bit in terms of its operation and design. Kammerer apparently teaches a rotary drill bit having a center bore through which drilling fluid is pumped downward such that the fluid pushes the cuttings outward from the cutters washing them toward the well bore and then upward. The Kammerer drill bit would therefore be totally unsatisfactory for the removal of items such as well packers which become jammed within a well casing. The cuttings would become jammed between the drill bit and the casing preventing such cuttings from being flushed from the casing. This would result in a build-up of cuttings between the drill bit and the jammed packer. Ultimately, either the drill bit would seize cutting further into the jammed packer due to the build-up of cuttings or, the build-up of cuttings would cause the drill bit to seize or jam within the casing preventing further rotational movement.
U.S. Pat. No. 3,385,385 to Kucera et al teaches a roller drill bit for drilling through earth formations. The design of the cutters of Kucera et al do not direct the cuttings and debris inward nor does Kucera et al teach the flushing of the debris inward and up through the center bore of the drill bit. As such, the Kucera et al drill bit design is insufficient for the removal of well packers or other items which may become jammed within the casing of an oil or gas well.
U.S. Pat. No. 3,126,973 to Kiel teaches yet another rotary drill bit directed to drilling through earth formations. Kiel's drill bit is three conical cutters which have noncircular rows of teeth. The purpose of the noncircular rows of teeth is apparently to generate a vibratory action to increase penetration. The shaft is provided with a center bore through which fluid is pumped downward to flush debris outward from the drill bit. As such, the Kiel drill bit design is inadequate for the purpose of removing well packers or other items jammed within the casing of oil and gas wells.
U.S. Pat. No. 3,081,829 to Williams, Jr. teaches yet another drill bit design directed to boring holes into earth formations. As is the case with the prior art patents previously mentioned, Williams, Jr. does not teach cutters which direct the cuttings inward toward the center of the drill bit nor does it teach the flushing of such cuttings upward through the central bore of the bit. The same can be said for U.S. Pat. Nos. 2,094,856 to Smith et al and 2,533,260 to Woods. None would be adaptable for use in drilling out or through packers or other items jammed within the casing of an oil or gas well.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a drill bit which can drill out and/or through well packers or other items which become jammed within the casing of an oil or gas well.
It is a further object of the present invention to provide a drill bit which prevents the cuttings and debris from becoming jammed between the drill bit and the well casing.
Yet another object of the present invention is to provide a drill bit in which the cutters are designed and arranged such that they direct the cuttings inwardly toward the axial center of the drill bit.
A further object of the present invention is to provide a drill bit which controls the size of the cuttings it creates.
Still another object of the present invention is to provide a drill bit in which the cuttings are flushed upward through the central bore of the drill bit and stem.
Briefly stated, the foregoing and numerous other objects and advantages of the present invention are accomplished by arranging the cutters on the drill bit in arcs of decreasing radius and positioning such cutters so that they cutting face of each cutter directs the cuttings inwardly toward the center of the drill bit. The drill bit has a central bore through which cuttings and debris may be flushed to the surface. Fluid is pumped down the casing between the drill bit and the casing. The drill bit is provided with notches or channels in its circumference to permit the fluid to pass freely between the drill bit and the well casing. In this manner, the fluid crosses the face of the drill bit thereby flushing the cuttings and debris from the cutters inward to the central bore.
As stated above, the cutters are arranged in arcs of decreasing radius. Depending on the diameter of the drill bit, the cutters may be arranged in 1, 2, 3 or 4 arcs. Regardless of the number of arcs, the lead cutter of each arc is disposed at a position furthest from the central axis of the drill bit. The cutters which follow are each disposed slightly inwardly toward the central axis of the drill bit from the cutter immediately in front of it in the arc. In such manner, the cutters on a single arc can be made to slightly overlap one another to cut one broad surface in a series of narrow shavings. Alternativley, the cutters can be spaced such that as they cut a gap is left in the surface between cut between one cutter and the next thus creating a rake pattern. The high points left in the rake pattern would be cut by a second arc of cutters.
The cutters are positioned such that their cutting surface is offset 30° inwardly form a line projecting radially outwardly from the center of the drill bit. This directionining of the cutters aids in projecting the cuttings inwardly toward the center. Further, the back of each cutter is sloped in such manner toward the center of the drill bit that as cuttings curl forward from each cutting face, should they begin to move outwardly, they will encounter the sloped rear face of the cutter immediately in front and be deflected toward the central bore of the drill bit.
Each drill bit is provided with two governors which control the depth of cut that each cutter makes. Such governors are actually cylindrical pieces of carbide having a flat surface projecting outward from the drill bits substantially parallel to the cutters. The flat surfaces are set such a distance such that they project from the drill bit slightly less than the cutting surface of each cutter. This difference in extension between the cutter and the governor prevents the cutter from gouging deeply into the surface being cut and allows one to set the maximum thickness of the individual cuttings. Thus, not only does the present invention direct the cuttings inwardly, but it also controls the width and thickness of each cutting thus making sure that the central bore does not become plugged with large pieces of debris so that flushing can be continuous.
Each drill bit is also provided with two other cutting surfaces located at 180° apart from one another at the extreme outside of the drill bit. These cutting surfaces provide backup should one of the lead cutters become damaged or broken. Each of the secondary cutters is provided with a sloped shoulder which rises to a flat surface projecting from the drill bit an identical distance as each of the governors. In such manner, these shoulders on the secondary cutters also govern the depth of cut.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of the drill bit of the presnt invention.
FIG. 2 is an elevational view of the main body of the drill bit of the present invention.
FIG. 3 is an end view of FIG. 2 taken along lines 3--3.
FIG. 4 is a detailed partial section taken along lines 4--4 of FIG. 3.
FIG. 5 is a partial section taken along lines 5--5 of FIG. 3.
FIG. 6 is a sectional view taken along lines 6--6 of FIG. 3.
FIG. 7 is a partial section taken along lines 7--7 of FIG. 3.
FIG. 8 is an end view of the drill bit of the present invention.
FIG. 9 is a partial section taken along lines 9--9 of FIG. 8.
FIG. 10 is an enlarged view of the cutting edge of the secondary cutters.
FIG. 11 is a partial section taken along lines 11--11 of FIG. 8.
FIG. 12 is a partial section taken along lines 12--12 of FIG. 8.
FIG. 13 is a partial section taken along lines 13--13 of FIG. 8.
FIG. 14 is a detailed partial elevation of the cutter of the present invention.
FIG. 15 is a detailed end view of the cutter of the present invention.
FIG. 16 is a partial section taken along lines 16--16 of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning first to FIG. 1, there is shown the drill bit 10 of the present invention. Drill bit 10 is substantially cylindrical in shape and has in its face a series of bores 12 which provide residence for cutters 14. Bores 12 and consequently cutters 14 are arranged in arcs or flutes 16 of decreasing radius. The lead cutter 18 of each arc or flute 16 is disposed such that its cutting path is slightly inside the outside diameter of the drill bit 10. Because of its position at the outside diameter of the drill bit 10, lead cutter 18 and its corresponding bore 20 cannot be perpendicular to the face 22 of the drill bit 10. Therefore, bore 20 and lead cutter 18 are directed into drill bit 10 at an angle which converges with the central axis of the drill bit 10.
Notches or channels 24 are placed along the cylindrical surface of drill bit 10. These notches or channels 24 allow fluid to be pumped down through the well casing between the drill bit 10 and the well casing. When the fluid is pumped in such manner, it flows across the cutters 14 substantially radially inward toward the central bore 26. In such manner, the cuttings and drilling debris are flushed inwardly from the cutters 14 and up the central bore of the drill bit 10 where they exit the well. The area of the notches or channels 24 is substantially equal to the area of the central bore 26 so that a steady flow rate can be maintained for the fluid entering and exiting the well.
The cutting face 28 and cutting edge 29 of the lead cutters 18 are substantially parallel to a line projecting radially from the central axis of the drill bit 10. In other words, the cutting face 28 and cutting edge 29 of the lead cutter 18 are substantially perpendicular to the arc of rotation of the drill bit 10. The cutting faces 30 and cutting edges 31 of the trailing cutters 14 are positioned such that they create an angle of intersection A with a line extending radially from the center of drill bit 10. It is preferable that this angle A be 30° but experiments have shown that angles of 10° through 40° will work effectively. This angle A of cutting faces 14 help direct the cuttings and drilling debris inwardly toward the central bore 26.
The lead cutter 18 and trailing cutters 30 may be positioned such that they slightly overlap one another progressively inward along arc or flute 16. In such manner, the cutters 14, 18 in each arc or flute 16 cut the same area. Alternatively, the cutters 14, 18 can be positioned such that there is a gap in the cutting path between cutting edges 29, 31. In this manner, each arc or flute 16 would cut a rake-like pattern into the surface being cut thus creating a series of arcuate grooves and ridges. The cutters 14, 18 of the second arc or flute 16 would be positioned such that their cutting edges 29, 31 would cut the ridges of material left by the first arc or flute 16 of cutters 14, 18. Drill bit 10 is provided with a series of radial bores 32 drilled radially inward from the cylindrical surface of drill bit 10 in close proximity to the face 22 of drill bit 10. These bores 32 provide residence for locking pins 34. There is one bore 32 and locking pin 34 corresponding to each cuttter 14, 18. Each of the bores 32 intersects a corresponding bore 12, 20 perpendicularly. Thus, with the exception of the bores 32 corresponding to lead cutter(s) 18 and its bore(s) 20, all bores 32 are directed substantially perpendicular to the central axis of the drill bit 10.
At the base of each cutter 14, 18 there is a V-notch 36. The interaction between each V-notch 36 and its corresponding locking pin 34 prevents rotational movement of the cutters 14, 18 and allows cutting faces 28, 30 to be fixed in the desired positions thus setting the value for angle A. Further, the interaction of each V-notch 36 and its corresponding locking pin 34 precisely sets the distance each cutting edge 29, 31 extends from face 33.
Each cutter 14 has shoulders 38 which slope away from cutting edge 31 thus creating clearance angles for each cutter 14. It is preferable that such clearance angles be approximately 30° however, it is noted that clearance angles of 5° through 60° have been found to be acceptable. It is also noted that it is not necessary that the clearance angles be equivalent.
Toward the rear of each cutter 14 there is a deflecting slope 40. The angle created between the top 42 of deflecting slope 40 and the cutting face 30 is 35°. This deflector angle aids in directing cuttings which may curl off one of the trailing cutters 14 toward the central bore 26. Deflector slope 40 rests at an angle of approximately 5° from vertical.
Cutting face 30 preferably has a depth of 0.110 inches but depths varying from 0.020 inches through 0.200 inches have been found to be adequate depending primarily on the type of material being cut.
Cutting face 30 is comprised of intersecting slopes 44 and 46. Slope 44 lies at an angle of 18° from the vertical while slope 46 lies at an angle of 18° from the horizontal. However, it should be understood the angles of slopes 44 and 46 may vary from 0° to 30° and need not be equivalent to one another again depending on material being cut. Slopes 44 and 46 intersect at radius 48. Radius 48 is preferably 0.062 inches but tests have shown that radii varying from 0.020 inches to 0.100 inches and greater are adequate. As is the case with other dimensions specified herein, dimensions outside the ranges given may also be acceptable.
The top rear portion 50 of each cutter 14 slopes back from cutting edge 31 at an angle of approximately 7° and increases to 15°. The width of cutting edge 31 determines the width of the cutting removed as drill bit 10 rotates. Because it is desired to keep the cuttings relatively small to make sure that central bore 26 does not become clogged, the width of cutting edge 14 should generally be no greater than 3/16ths of an inch. However, the width of cutting edge 14 may even become greater depending on the diameter of the bit 10 and type of material being cut. Preferably, the width of cutting edge 31 should be maintained at 0.100 inches.
The overall dimensions of each cutter 14, of course, may vary depending upon the diameter of the drill bit 10 in which they are used. However, it has been found that an overall length of 1.5 inches and a diameter of 0.375 inches works well.
The face 33 of drill bit 10 is also provided with two larger cylindrical bores 54 which are parallel to the cylindrical axis of drill bit 10. Cylindrical bores 54 provide residence for feed control rods 56. Feed control rods 56 extend outwardly or downwardly from the face 22 of drill bit 10 to a distance which is slightly less than the distance which cutting edges 29, 31 extend from the face 22 of drill bit 10. The large flat surface provided by feed control rod 56 acts as a governor which prevents cutting edges 29, 31 and cutting faces 28, 30 from gouging too deeply into the article being cut and therefore prevents cutting edges 29, 31 and cutting faces 28, 30 from taking overly thick cuttings. It has been found that it is preferable to allow cutting edges 29, 31 to extend approximately 0.002-0.003 inches further from the face 22 of drill bit 10 than does feed control rod 56 when cutting through materials such as Hastelloy or Inconel. If the material being cut was steel, it would be preferable to allow cutting edges 29, 31 to extend approximately 0.010 inches further from the face 22 of drill bit 10 than does feed control rod 56. This will allow cutting edge 52 and cutting face 30 to cut very fine shavings from the article which is jammed in the well casing. These fine shavings are easily directed and flushed to the central bore 26.
The face 22 of drill bit 10 is also provided with secondary cutters 58 disposed toward the outside diameter of drill bit 10. Secondary cutters 58 provide back-up cutting capability should one of the lead cutters 18 become damaged or broken. Further, secondary cutters 58 provide substantially full diameter cutting capability for the drill bit 10. The cutting edge 60 of secondary cutter 58 is provided with a series of notches 62 which serve to limit the width of the cuttings delivered by secondary cutters 58. Cutting edge 60 is the furthest extending portion of secondary cutter 58 downwardly from the face 22 of drill bit 10. Shoulder 64 which projects rearward from cutting edge 60 slopes downward toward the face 22 of the drill bit 10. Shoulder 64 then intersects with planar surface 66 thus creating a valley 68 behind cutting edge 60. Planar surface 68 serves as a secondary governor or feed control. Planar surface 68 extends from the face of drill bit 10 slightly less than cutting edge 60 extends from the face 22 of drill bit 10. It is preferably that this dimension be equal to the difference that cutting edges 29, 31 extend beyond feed control rod 56.
In the preferred embodiment, each of the cutters 14, 18, 58 are carbide and are silver soder brazed in place. However, cutters 14, 18, 58 may be press-fitted, screwed or brazed in place.
In operation, a series of fine cuttings are removed from the article which is jammed within the well casing. These cuttings are directed inwardly toward the central bore 26 by cutters 14, 18, 58. Further, the cuttings are flushed inwardly toward central bore 26 by fluid which is circulated between drill bit 10 and the well casing through notches or channels 24. In such manner, the cuttings are prevented from becoming jammed between the drill bit and the well casing or from building up between the drill bit 10 and the well casing. Substantially all of the cuttings are flushed upward through central bore 26 and out of the well.
From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the device.
It will be understood that certain features and subcombinations are of utility and may be employed with 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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Disclosed is a drill bit for use downhole in oil and gas wells. It is particularly adoptable for use in removing obstructions such as well packers which may become jammed within the casings of oil and gas wells. Cutters are arranged on the cutting face of the drill bit in arc-like patterns of decreasing radius. The shear angle of each cutter combined with the arc-like pattern in which the cutters are arranged serve to direct the cuttings and drilling debris inward toward the central bore. Fluid can be pumped down through the well casing and circulated about the drill bit through longitudinal channels provided in the main body of the drill bit. In such manner, the fluid circulates downward within the casing and across the cutting face of the drill bit carrying the cuttings and drilling debris up through the central bore thus preventing the cuttings in drilling debris from building up within the casing or causing the drill bit to jam within the casing.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application claims the benefit of U.S. Provisional Application No. 62/259,370, filed 24 Nov. 2015, which is herein incorporated by reference.
COPYRIGHT NOTICE
[0002] A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
FIELD
[0003] The presently described subject matter relates to transferring non-mechanical forms of energy to or from the body. More particularly, the described subject matter relates to transferring radiofrequency energy into the heart for ablation.
BACKGROUND
[0004] Mapping of electrical potentials in the heart is now commonly performed, using cardiac catheters comprising electrophysiological sensors for mapping the electrical activity of the heart. Typically, time-varying electrical potentials in the endocardium are sensed and recorded as a function of position inside the heart, and then used to map a local electrogram or local activation time.
[0005] When conduction abnormalities, such as atrial fibrillation are present, radiofrequency (RF) ablation of the heart is a procedure that is widely used to correct problematic cardiac conditions. The procedure typically involves insertion of a catheter having an electrode into the heart, and ablating selected regions within the heart with RF energy transmitted via the electrode.
SUMMARY
[0006] Safety requirements can be limiting factors in miniaturization of devices for intra-body applications. For example, catheters used for electrophysiological procedures have various sensors in their distal portions, while processing of the signals from the sensors can occurs proximally. However, providing signal processing capabilities in the distal portion of the catheter can improve the quality of the electrophysiological data and measurements. Signal processing circuitry requires electrical power to be supplied to the distal portion of the catheter. If mechanical failure of the catheter shaft or a short circuit in the power wires supplying the signal processing circuitry were to occur, the subject could experience an electrical shock. The presently described subject matter is directed to methods and systems that provide electrical safety in devices for intra-body applications.
[0007] The presently described subject matter is directed to a method, comprising disposing electrical power circuitry outside a medical catheter; disposing remote internal circuitry within the medical catheter; isolating at least one of the power circuitry and the internal circuitry from electrical ground; connecting the power circuitry to the internal circuitry by two wires, for example, by exactly two wires; and communicating an alternating carrier from the power circuitry to the internal circuitry via the two wires. The method may further comprise performing half-duplex data communication between the power circuitry and the internal circuitry by, for example, alternately modulating the carrier voltage amplitude with one of the power circuitry and the internal circuitry and decoding the modulated carrier voltage amplitude with another of the power circuitry and the internal circuitry.
[0008] According to one aspect of the presently described method, the power circuitry can comprise a transceiver for modulating the carrier voltage amplitude and a decoder for demodulating the carrier voltage amplitude.
[0009] According to a further aspect of the presently described method, the internal circuitry can comprise a decoder for demodulating the carrier voltage amplitude.
[0010] Yet another aspect of the method can comprise obtaining and processing data in the internal circuitry from sensors in the catheter and modulating the carrier voltage amplitude according to the processed data for communication a decoder to the power circuitry.
[0011] According to still another aspect of the method alternately modulating the carrier voltage amplitude is performed with a first switch in the power circuitry and with a second switch in the internal circuitry to vary first and second resistances across the alternating carrier, respectively.
[0012] According to certain embodiments of the presently described subject matter an apparatus, further provided is an apparatus comprising a medical catheter; electrical power circuitry disposed outside the catheter; and remote internal circuitry disposed within the catheter. At least one of the power circuitry and the internal circuitry is isolated from electrical ground. The apparatus may further include two wires, for example, exactly two wires, connecting the power circuitry to the internal circuitry, and a signal generator for generating an alternating carrier that is communicated from the power circuitry to the internal circuitry via the wires. Decoders are disposed in the power circuitry and the internal circuitry, and a transceiver performs half-duplex data communication between the power circuitry and the internal circuitry. The transceiver is operative for alternately modulating the carrier voltage amplitude in one of the power circuitry and the internal circuitry and decoding the modulated carrier voltage amplitude in the decoder of another of the power circuitry and the internal circuitry.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0013] For a better understanding of the presently described subject matter, reference is made to the detailed description of the presently described subject matter, by way of example, which is to be read in conjunction with the following drawings, wherein like elements are given like reference numerals, and wherein:
[0014] FIG. 1 is a pictorial illustration of a system, which is constructed and operative in accordance with a disclosed embodiment of the presently described subject matter;
[0015] FIG. 2 is an electrical schematic of an embodiment of a system for digital communication in accordance with an embodiment of the presently described subject matter; and
[0016] FIG. 3 is a flow chart illustrating a sequence of operations using the system shown in FIG. 2 in accordance with an embodiment of the presently described subject matter.
DETAILED DESCRIPTION
[0017] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the various principles of the presently described subject matter. It will be apparent to one skilled in the art, however, that not all these details are necessarily needed for practicing the presently described subject matter. In this instance, well-known circuits, control logic, and the details of computer program instructions for conventional algorithms and processes have not been shown in detail in order not to obscure the general concepts unnecessarily.
[0018] Documents incorporated by reference herein are to be considered an integral part of the application except that, to the extent that any terms are defined in these incorporated documents in a manner that conflicts with definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.
Overview
[0019] Turning now to the drawings, reference is initially made to FIG. 1 , which is a pictorial illustration of a system 10 for evaluating electrical activity and performing ablative procedures on a heart 12 of a living subject, which is constructed and operative in accordance with a disclosed embodiment of the presently described subject matter. The system comprises a catheter 14 , which is percutaneously inserted by an operator 16 through the patient's vascular system into a chamber or vascular structure of the heart 12 . The operator 16 , who is typically a physician, brings the catheter's distal tip 18 into contact with the heart wall, for example, at an ablation target site. Electrical activation maps may be prepared, according to the methods disclosed in U.S. Pat. Nos. 6,226,542, and 6,301,496, and in commonly assigned U.S. Pat. No. 6,892,091, whose disclosures are herein incorporated by reference. One commercial product embodying elements of the system 10 is available as the CARTO® 3 System, available from Biosense Webster, Inc., 3333 Diamond Canyon Road, Diamond Bar, Calif. 91765. This system may be modified by those skilled in the art to embody the principles of the presently described subject matter.
[0020] Areas determined to be abnormal, for example by evaluation of the electrical activation maps, can be ablated by application of thermal energy, e.g., by passage of radiofrequency electrical current through wires in the catheter to one or more electrodes at the distal tip 18 , which apply the radiofrequency energy to the myocardium. The energy is absorbed in the tissue, heating it to a point (typically about 50° C.) at which it permanently loses its electrical excitability. When successful, this procedure creates non-conducting lesions in the cardiac tissue, which disrupt the abnormal electrical pathway causing the arrhythmia The principles of the presently described subject matter can be applied to different heart chambers to diagnose and treat many different cardiac arrhythmias.
[0021] The catheter 14 can comprise a handle 20 , having suitable controls on the handle to enable the operator 16 to steer, position and orient the distal end of the catheter as desired for the ablation. To aid the operator 16 , the distal portion of the catheter 14 contains position sensors (not shown) that provide signals to a processor 22 , located in a console 24 . The processor 22 may fulfill several processing functions as described below.
[0022] Ablation energy and electrical signals can be conveyed to and from the heart 12 through one or more ablation electrodes 32 located at or near the distal tip 18 via cable 34 to the console 24 . Pacing signals and other control signals may be conveyed from the console 24 through the cable 34 and the electrodes 32 to the heart 12 . Sensing electrodes 33 , also connected to the console 24 are disposed between the ablation electrodes 32 and have connections to the cable 34 .
[0023] Wire connections 35 link the console 24 with body surface electrodes 30 and other components of a positioning sub-system for measuring location and orientation coordinates of the catheter 14 . The processor 22 or another processor (not shown) may be an element of the positioning subsystem. The electrodes 32 and the body surface electrodes 30 may be used to measure tissue impedance at the ablation site as taught in U.S. Pat. No. 7,536,218, issued to Govari et al., which is herein incorporated by reference. A temperature sensor (not shown), including for example, a thermocouple or thermistor, may be mounted on or near each of the electrodes 32 .
[0024] The console 24 may contain one or more ablation power generators 25 . The catheter 14 may be configured to conduct ablative energy to the heart using any known ablation technique, including for example, but not limited to, radiofrequency energy, ultrasound energy, and laser-produced light energy. Such methods are disclosed in commonly assigned U.S. Pat. Nos. 6,814,733, 6,997,924, and 7,156,816, both of which are herein incorporated by reference.
[0025] In one embodiment, the positioning subsystem can comprise a magnetic position tracking arrangement that determines the position and orientation of the catheter 14 by generating magnetic fields in a predefined working volume and sensing these fields at the catheter, using field generating coils 28 . The positioning subsystem is described in U.S. Pat. No. 7,756,576, which is hereby incorporated by reference, and in the above-noted U.S. Pat. No. 7,536,218.
[0026] As noted above, the catheter 14 is coupled to the console 24 , which enables the operator 16 to observe and regulate the functions of the catheter 14 . Console 24 includes a processor, preferably a computer with appropriate signal processing circuits. The processor is coupled to drive a monitor 29 . The signal processing circuits typically receive, amplify, filter, and digitize signals from the catheter 14 , including, for example, signals generated by sensors, including but not limited to, electrical, temperature, and contact force sensors, and a plurality of location sensing electrodes (not shown) located distally in the catheter 14 . The digitized signals are received and used by the console 24 and the positioning system to compute the position and orientation of the catheter 14 , and to analyze the electrical signals from the electrodes.
[0027] Typically, the system 10 includes other elements, which are not shown in the figures for the sake of simplicity. For example, the system 10 may include an electrocardiogram (ECG) monitor, coupled to receive signals from one or more body surface electrodes, in order to provide an ECG synchronization signal to the console 24 . As mentioned above, the system 10 may also include a reference position sensor, either on an externally-applied reference patch attached to the exterior of the subject's body, or on an internally-placed catheter, which is inserted into the heart 12 maintained in a fixed position relative to the heart 12 . Conventional pumps and lines for circulating liquids through the catheter 14 for cooling the ablation site can be provided. The system 10 may receive image data from an external imaging modality, such as an MRI unit or the like and includes image processors that can be incorporated in or invoked by the processor 22 for generating and displaying images.
[0028] Reference is now made to FIG. 2 , which is an electrical schematic of an embodiment of a system for digital communication in a catheter using two alternating current (AC) coupling wires in accordance with an embodiment of the presently described subject matter. The components shown are dimensioned to an intra-body catheter.
[0029] A system 40 comprises electrical power circuitry 42 , which is can be located outside the catheter, for example, in the console 24 ( FIG. 1 ). Power circuitry 42 comprises an alternating current signal generator 44 connected in a power supply circuit 46 . The signal generator 44 generates a carrier frequency in the range of tens or hundreds of kHz. The AC current passes through a network comprising resistors R 1 , R 2 and capacitors C 1 , C 2 . The AC current is used both as an electrical energy source for remote circuitry 48 and as the carrier frequency for information transfer between the power circuitry 42 and remote circuitry 48 .
[0030] Power circuitry 42 includes a signal processing module 50 , which controls a switch 52 (ON/OFF) to modulate the carrier frequency. The signal processing module 50 includes an amplifier 54 and a transceiver 56 . The amplifier 54 receives and decodes or demodulates signals that are received from internal remote circuitry 48 . The transceiver 56 handles communications that are directed to the remote circuitry 48 .
[0031] The remote circuitry 48 comprises an energy harvesting component 58 , a measurement and processing component 60 and an amplifier and decoder 62 for demodulating the carrier voltage amplitude. The energy harvesting component 58 , which can be model LTC3331 from Linear Technology, converts the AC voltage at its input to a DC voltage and charges the storage capacitor C 5 to a constant value that can be in the range of 3 to 10 volts direct current (VDC). The measurement and processing component 60 and amplifier and decoder 62 are switched in when the DC voltage on the capacitor C 5 reaches a predetermined value by switch 64 .
[0032] As noted above, the remote circuitry 48 is remote from the power circuitry 42 . The power circuitry 42 and the remote circuitry 48 are connected by a wire pair 66 . The wire pair 66 may be implemented by a twisted pair that reduces sensitivity to external magnetic fields.
Operation
[0033] An AC carrier current produced by signal generator 44 passes through resisters R 3 , R 4 and capacitors C 3 , C 4 in the power circuitry 42 ; then through wire pair 66 into the remote circuitry 48 . Data communication between the power circuitry 42 and remote circuitry 48 is implemented by carrier voltage amplitude modulation. The signal generator 44 together with the resistors R 1 and R 2 act as the current source and the voltage across the wires of the wire pair 66 depends on the impedance across the two wires.
[0034] When both switches 52 , 64 are open, i.e., in an OFF state, and the impedance of the capacitors C 1 and C 2 at the carrier frequency is much less than the values of R 1 and R 2 , the transmission (Tx) voltage between the wires assumes a first value:
[0000] Tx=V 1*[ Rc /( R 1+ R 2+ Rc )],
[0000] where V 1 is the output voltage of the signal generator 44 and Rc is the impedance of the parasitic capacitance and the load of the remote circuitry 48 at the carrier frequency.
[0035] As noted above, the signal processing module 50 modulates the carrier voltage amplitude by varying switch 52 between open and closed positions. Signal processing module 50 influences only switch 52 and the remote circuitry 48 influences switch 64 . When switch 52 is closed and switch 64 is open, the Tx voltage between across the wire pair 66 assumes a second value:
[0000] Tx=V 1*( Rc/R 1+ R 2+ Rc+R 6.
[0036] When switch 52 is opened and switch 64 is closed the Tx voltage between across the wire pair 66 assumes a third value:
[0000] Tx=V 1*( Rc/R 1+ R 2+ Rc+R 5).
[0037] The amplifier and decoder 62 in the remote circuitry 48 receives the modulated carrier voltage and demodulates the information that is embedded in the input signal.
[0038] Reference is now made to FIG. 3 , which is a flow chart illustrating a sequence of operations using the system 40 ( FIG. 2 ), in accordance with an embodiment of the presently described subject matter. The process steps are shown in a particular linear sequence for clarity of presentation. However, it will be evident that many of them can be performed in parallel, asynchronously, or in different orders. Those skilled in the art will also appreciate that a process could alternatively be represented as a number of interrelated states or events, e.g., in a state diagram. Moreover, not all illustrated process steps may be required to implement the method.
[0039] At initial step 68 switches 52 , 64 are both opened. The voltage at energy harvesting component 58 is maximal and it charges the storage capacitor C 5 . When the storage capacitor is charged, the remote unit 48 is ready to work.
[0040] Next, communication step 70 is performed, which comprises two steps 72 , 74 , which are performed in alternation, i.e., the communication is half-duplex. Any suitable communications protocol may be used:
[0041] In step 72 the remote circuitry 48 transmits data to the signal processing module 50 , modulating a carrier voltage by opening and closing switch 64 . Switch 52 remains open during step 72 .
[0042] In step 74 the signal processing module 50 transmits commands to the remote circuitry 48 , modulating the carrier voltage by opening and closing switch 52 . Switch 64 remains open during step 74 .
[0043] It should be noted that the remote circuitry 48 is fully isolated from the power circuitry 42 . There is no common ground connection between the two components. If a short between the wires of the wire pair 66 should occur, the patient would be exposed only to a low voltage. Disconnection would result in a higher voltage than normal but still within a low range, so that patient safety would not be compromised. For example, if the generator's output voltage is no more than 2 V and resistors R 1 , R 2 are in the range of 50 kΩ, the maximum current through the patient's body would be 2V/100 kΩ=20 uA. In this regard, it may be noted that the maximum allowable current through the patient's body in a single fault condition according to the standard IEC60601-1 is 50 uA.
[0044] It will be appreciated by persons skilled in the art that the presently described subject matter is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present presently described subject matter includes both combinations and sub-combinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description.
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Provided are a method and apparatus for performing medical catheterization using electrical power circuitry disposed outside a medical catheter and remote internal circuitry disposed within the medical catheter. At least one of the power circuitry and the internal circuitry is isolated from electrical ground. Exactly two wires connect the power circuitry to the internal circuitry and a signal generator is provided for generating an alternating carrier that is communicated from the power circuitry to the internal circuitry via the wires. Decoders are disposed in the power circuitry and the internal circuitry, and a transceiver performs half-duplex data communication between the power circuitry and the internal circuitry by alternately modulating the carrier voltage amplitude in one of the power circuitry and the internal circuitry and decoding the modulated carrier voltage amplitude in another of the power circuitry and the internal circuitry.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a recording medium for a sublimation type heat-sensitive transfer recording process.
(2) Prior Art
Sublimation type heat-sensitive transfer recording process have various advantages, including quiet operation, compactness, low cost, and simple maintenance of the recording device. In addition short output time and high gradation recording is easily achieved by changing the amount of thermal energy on the sublimation disperse dye continuously; and high-density and high-resolution recording is also possible.
With these favorable characteristics, sublimation type heat-sensitive recording method are far more advantageous than any other recording method in production. In particular, it is capable of producing full-color hard copies, and it has been extensively used as the recording method for color printers and video printers.
The recording medium for sublimation type heat-sensitive transfer recording method normally consists of a substrate of cellulosic fiber paper or synthetic paper (mainly polypropylene paper), which is coated with a dye-accepting layer. The above substrate, however, has several disadvantages: it tends to curl after being recorded with heat from the thermal head, thereby degrading the transport characteristics of the recording medium in the printer; the curled print-outs also cause problems with respect to handling and filing.
In an attempt to solve the above problems, laminated paper made of cellulosic fiber paper bonded to synthetic paper has been proposed for the substrate, as disclosed in Japanese Patent Application, first publication No.(Tokukai Sho) 62-198497. It is, however, still difficult to totally eliminate curling even with this substrate due to the fact that dissimilar materials of different linear thermal expansion coefficients have been laminated together. Another disadvantage is its increased cost due to the use of expensive synthetic paper made of plastics. Other methods have been proposed to prevent curling; Japanese Patent Application, first publication No.(Tokukai Sho) 63-214484 discloses a substrate of synthetic paper that is lined on the back with a bonded layer of cellulosic fiber paper or plastic film. Japanese Patent Application, first publication No.(Tokukai Hei) 1-44781 discloses a substrate which is coated on the back with thermoplastic resin or a similar material to prevent curling. Each of these substrates, however, tends to be expensive, running counter to the goal of cost reduction.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a recording medium for sublimation type heat-sensitive transfer processes, recording, which causes essentially no curling and is produced at a low cost.
The present invention provides a recording medium for sublimation type for heat-sensitive transfer recording process which comprises laminated paper as the substrate. In this laminated paper at least two cellulosic fiber papers are bonded together by adhesive agent and one side is coated with a dye accepting layer.
Therefore, the recording medium for sublimation type for heat-sensitive transfer recording process which the present invention concerns uses, as the substrate, laminated paper in which cellulosic fiber papers are bonded together. This structure almost completely prevents curling of the recorded medium and also lowers the substrate production cost to achieve a low-cost recording medium and thereby greatly contribute to the expanded use of sublimation type recording printers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross section of the structure of the recording medium for a sublimation type heat-sensitive transfer process according to the present invention.
FIG. 2 is a cross section of another structure of the recording medium for a sublimation type heat-sensitive transfer process according to the present invention.
FIG. 3 is a cross section of yet another structure of the recording medium for a sublimation type heat-sensitive transfer process according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described in detail.
FIG. 1 is a schematic cross section of a structure of the recording medium of the present invention. As shown in this figure, the first cellulosic fiber paper 1 is bonded to the second cellulosic fiber paper 3 via the adhesive layer 4 to form the substrate, which is coated with the dye-accepting layer 2.
The first cellulosic fiber paper 1 on which comes in contact with the dye-accepting layer 2 is not limited to this type of paper, though it must be a plain paper made of cellulose. It is, however, preferable to use paper whose surface is smooth to attain recorded images of acceptable quality. Preferable types of cellulosic fiber paper include art or coated paper. It is also recommended that the thickness of the entire recording medium be in the range of from 50 to 250 μm: a recording medium consisting of excessively thin cellulosic fiber paper will curl to an unacceptable extent, while that of excessively thick cellulosic fiber paper will experience transport problems during operation in the printer.
Material for the second cellulosic fiber paper 3 is not limited; it may be the same as, or different from, that of the first cellulosic fiber paper 1. Its thickness, however, is preferably be determined so as to achieve the proper thickness of the entire recording medium, as described above. Moreover, the back of the second cellulosic fiber paper 3 may be coated with a special layer to improve transport characteristics of the recording medium in the printer, or with an antistatic layer to prevent the accumulation of static electricity while the recording medium is running in the printer.
Basically, two cellulosic fiber papers are bonded together to form the substrate. However, the substrate may have a total of three bonded cellulosic fiber papers in which the third cellulosic fiber paper 6 is placed between the first and second cellulosic fiber papers 1 and 3 as illustrated in FIG. 2, in order to secure an adequate thickness of the recording medium, or to further prevent curling of the recorded medium.
Four or more cellulosic fiber papers may be laminated to form the substrate, but it is preferable to limit the number of cellulosic fiber papers to three for reasons of productivity and production cost.
Any adhesive agent may be used for the adhesive layer 4 provided it is normally used for bonding paper or plastic film. However, in view of ease of bonding and elasticity, it is preferred to use adhesives which are conventionally used for dry laminates, for example, urethane type adhesives for dry laminates, such as AD-COAT produced by Toyo-Morton. Furthermore, the adhesive agent is spread over the surface preferably in the range of from 1 to 10 g/m 2 ; an excessively thin adhesive layer is apt to produce poor images, while an excessively thick layer is apt to create an overall recording medium that is unacceptably thick. To reduce curling of the recording medium, it is recommended that when two cellulosic fiber papers 1 and 3 are bonded, a tension exerted on the second cellulosic fiber paper 3 is higher than that on the first cellulosic fiber paper 1, rather than being bonded at the same tension to these papers. It should be noted, however, when the both papers 1 and 3 are bonded the tension exerted on the second cellulosic fiber paper is excessively higher than that on the first paper 1, the recording side will be curved convexly before recording, thus degrading the transport characteristics of the recording medium. The ratio of tension between the first cellulosic fiber paper on which the dye-accepting layer is formed and the second cellulosic fiber paper should be in a range of from 1/1.5 to 1/20 preferably from 1/2 to 1/17.
When a total of three cellulosic fiber papers 1, 3 and 6 are laminated to form the substrate, the first cellulosic fiber paper 1 on which the dye accepting layer is formed may be first bonded to the third, intermediate, cellulosic fiber paper 6. The second cellulosic fiber paper 3 can then be bonded to the backside of the third cellulosic fiber paper 6. Alternatively, the second cellulosic fiber paper 3 may be first bonded to the third cellulosic fiber paper 6. The first cellulosic fiber paper 1 on which the dye-accepting layer 2 is formed can then be bonded to the third cellulosic fiber paper 6. It is preferable, as is the case when two cellulosic fiber papers are laminated, that the ratio A/B, in which A is the ratio of the tension between the first cellulosic fiber paper 1 and the third cellulosic fiber paper 6 (i.e. tension of the first cellulosic fiber paper 1:tension of the third cellulosic fiber paper 6) and B is the ratio of the tension between the second cellulosic fiber paper 3 and the third cellulosic fiber paper 6 (i.e. tension of the second cellulosic fiber paper 3:the third cellulosic fiber paper 6), is in a range of from 1/1.5 to 1/20, and preferably from 1/2 to 1/17.
Keeping the lamination tension within the above ratio will achieve a substrate which is remarkably curl-free after recording, even in the case where only cellulosic fiber paper is used.
The dye-accepting layer 2 is formed on one side of the laminated paper which has been prepared as above. It accepts the sublimation-type dye transferred from the transfer sheet, and colors develop. It may accepts dyes well and causes no blocking with ink during the recording process, material for the dye-accepting layer 2 is not limited. The preferrable materials for the dye-accepting layer 2 include, but are not limited to, resins having an ester bond, such as polyester, polyacrylic ester, polycarbonate, polyvinyl acetate, styrene acrylate resin or vinyl toluene acrylate resin; resins having an urethane bond, such as polyurethane; resins having a polyamide bond, such as polyamide (nylon); resins having an urea bond, such as urea; polycaprolactone, styrene-containing resins, polyvinyl chloride, vinyl chloride vinyl acetate copolymer or resin with a highly polar bond, such as polyacrylonitrile; or a mixture thereof, or a copolymer thereof. In addition to the above, resins may contain an inorganic filler, such as silica, calcium carbonate, titanium oxide or zinc oxide, a release agent, and a thermosetting component, such as isocyanate and polyol.
However, as disclosed in Japanese Patent Application, first publications Nos. (Tokukai-Sho) 62-46689 and 63-67188, it is recommended, for reasons of productivity and product quality, that the composition of dye-accepting layer 2 contain a sublimation type disperse dye acceptable resin, a cross-linking agent, and a release agent, the former agent capable of being hardened by an activation energy ray, after having been spread over the substrate. The resin for the dye accepting layer may be of the type described here. The cross-linking agent which can be hardened with an activation energy ray and, which is useful for the present invention includes monomer or oligomer containing an acryloyloxy or a mathacryloyloxy group. The release agent that can be used for the present invention includes a silicone-base or a fluorine-base surface-active agent; graft polymer having polyorganosiloxane in its main or branch chain, or a silicone-base or a fluorine-containing compound capable of forming cross-linked structures, such as a combination of amino-modified and epoxy-modified silicone. One or a combination of two or more of these release agents may be used. The dye-accepting layer 2 of the above composition can readily accept sublimation-type disperse dye, to develop colors that are highly stable and preserve their original brightness after recording.
The recording medium of the present invention may have an additional layer 5 as shown in FIG. 3, between the dye-accepting layer 2 and the first cellulosic fiber paper 1. This additional layer 5 is used to facilitate bonding, prevent accumulation of static electricity, improve whiteness, or achieve a combination of them.
For example, the material for the additional layer 5, which facilitates bonding, and improves adhesion of the dye-accepting layer 2 to the first cellulosic fiber paper 1, may be selected from various thermoplastic and thermosetting resins, depending on the composition of the dye-accepting layer 2 and the characteristics of the first cellulosic fiber paper 1.
The additional layer 5 can act as an anti-static layer, preventing dust from attaching to the recording medium, and preventing the recording media from sticking to each other as a result of static electricity. Therefore, degradation in transport of the medium through the printer is prevented. Materials useful for the anti-static layer include: an anti-static agent, such as anionic, cathionic, dipolar or non-ionic surface active agent; and an electrically conducting resin, such as polyvinylbenzyl type cathionic resins or polyacrylate-type cathionic resins. The above anti-static agent may be mixed with a binder polymer selected from various types of thermoplastic and thermosetting resins.
The additional layer 5 can also work to improve whiteness of the recording medium. Materials useful for this layer include: white pigment, such as titanium oxide and zinc oxide and/or a fluorescent whiteness improver, mixed with a binder polymer selected from various thermoplastic and thermosetting resins.
This additional layer 5 may be of a composite layer, exhibiting two or more functions as described above. This composite layer is formed by spreading the composition containing two or more of the above-described anti-static agents, a whiteness-improving pigment, a fluorescent-whiteness improver and/or the others, mixed in a binder polymer selected from various thermoplastic and thermosetting resins.
EXAMPLES
The present invention will be more clearly understood by referring to the following examples. The term "part" described in EXAMPLES and COMPARATIVE EXAMPLES means "part by weight."
* Preparation of the Substrate
SUBSTRATES 1 through 14
Two sheets of cellulosic fiber paper were bonded together, to prepare each of SUBSTRATES 1 through 14; the type of sheet and bonding tension for each substrate is given in Table 1. The adhesive agent used was urethane-base adhesive agent Toyo Morton's AD-COAT (trade name) consisting of two liquid adhesives, AD-577-1 and CAT-52. It was spread at 5 g/m 2 (dry basis) over the surface, dried at 80° C. for approximately 30 seconds, and aged at 40° C. for 3 days.
SUBSTRATES 15 through 20
Three sheets of cellulosic fiber paper were bonded together, to prepare each of SUBSTRATES 15 through 20; the type of sheet and bonding tension for each substrate is given in Table 2. The first cellulosic fiber paper on which the dye-accepting layer was to be placed was bonded to the third cellulosic fiber paper, and the second cellulosic fiber paper was bonded on the backside of the third cellulosic fiber paper. The adhesive agent used consisted of Toyo Morton's AD-577-1 and CAT-52. It was spread at 5 g/m 2 (dry basis) over the surface, dried at 80° C. for approximately 30 seconds, and aged at 40° C. for 3 days.
SUBSTRATE 21
Art paper (weight: 209.3 g/m 2 , thickness: approximately 180 μm) was used singly for the substrate.
SUBSTRATE 22
Synthetic paper of polypropylene (thickness: approximately 200 μm), supplied by Oji-Yuka Synthetic Paper Co. Ltd., was used singly for the substrate.
EXAMPLE 1 TO 20, COMPARATIVE EXAMPLES 1 and 2
Each of the SUBSTRATE 1 to 22 was dipped in and uniformly covered with the coating solution given in Table 3. Each of the substrate 1 to 22 was then irradiated in air with ultraviolet rays emitted from a high-pressure mercury lamp, to form the 5 to 6 μm-thick dye-accepting layer.
An image was recorded on the recording medium thus prepared using a video printer (Mitsubishi Electric's SCT-CP100). The color sheet (ink sheet) used was SCT-CK100TS provided for the above equipment.
The extent of curling of the recorded medium was determined by placing it on the flat surface of a desk and measuring the warp height at the four corners. The average value was reported for each recording medium, as shown in Table 4.
EXAMPLE 21
A 10% methanol solution of N-lauryl pyridinium chloride was spread over SUBSTRATE 7, described in Table 1, by a bar coater, and dried to form a uniform coating film. The same coating solution as used in EXAMPLE 1 was used to form the dye-accepting layer.
The same procedure as used in EXAMPLE 1 was repeated to assess the recording medium thus prepared. The results are given in Table 4.
EXAMPLE 22
The following composition was spread over SUBSTRATE 7, described in Table 1, by a wire bar, and dried to form a 10 μm, uniformly coated film. Then, the coating solution described in Table 3 was used to form the dye-accepting layer, in the same manner as used in EXAMPLE 1. The same procedure as used in EXAMPLE 1 was repeated to assess the recording medium thus prepared The results are given in Table 4.
______________________________________Copolymer of methyl methacrylate/ethyl 16 parts by weightacrylate/methacrylic acid (84/13/3)(weight-average molecular weight:approximately 90,000)Titanium oxide (Titanium Kogyo's KA-10) 4 parts by weightMethylethylketone 80 parts by weight______________________________________
The results given in Table 4 show that the recording medium of the present invention for sublimation type heat-sensitive transfer recording processes, which is characterized by achieving a reduced curling after recording, can be formed by the simple and convenient method of laminating only sheets of cellulosic fiber paper to prepare the substrate.
TABLE 1__________________________________________________________________________First Cellulosic Fiber Second Cellulosic FiberPaper 1*.sup.1 Paper 3*.sup.2 Weight Tension Weight Tension ThicknesssubstrateTypes (g/m.sup.2) (kg/m) Types (g/m.sup.2) (kg/m) (mm)__________________________________________________________________________1 Art Paper 104.7 4 Art Paper 104.7 4 1802 Art Paper 104.7 4 Art Paper 104.7 10 1803 Art Paper 104.7 4 Art Paper 84.9 10 1604 Art Paper 84.9 4 Art Paper 104.7 10 1605 Art Paper 104.7 4 Art Paper 104.7 30 1806 Art Paper 104.7 4 Art Paper 84.9 30 1607 Art Paper 84.9 4 Art Paper 104.7 30 1608 Art Paper 104.7 4 Art Paper 104.7 60 1809 Art Paper 104.7 4 Art Paper 84.9 60 16010 Art Paper 84.9 4 Art Paper 104.7 60 16011 Art Paper 104.7 3 Art Paper 104.7 75 18012 Coated 104.7 4 Coated 104.7 30 180Paper Paper13 Coated 84.9 4 Art Paper 104.7 30 160Paper14 Art Paper 104.7 4 High Quality 104.7 30 180 Paper__________________________________________________________________________ *.sup.1 The dyeaccepting layer side *.sup.2 Backside
TABLE 2__________________________________________________________________________First Cellulosic FiberPaper 1 Second Cellulosic Fiber(on the dye-accepting) Paper 3layer side) Third Cellulosic Fiber Paper 6 (back side) Tension TensionSUB- Weight Tension Weight 1 2 Weight Tension ThicknessSTRATE Types (g/m.sup.2) (kg/m) Types (g/m.sup.2) (kg/m) (kg/m) Types (g/m.sup.2) (kg/m) (μm)__________________________________________________________________________15 Coated 73.3 4 Coated 73.3 20 20 Coated 73.3 10 190 Paper Paper Paper16 Coated 73.3 4 Coated 73.3 20 20 Coated 73.3 30 190 Paper Paper Paper17 Coated 73.3 4 Coated 73.3 20 20 Coated 73.3 60 190 Paper Paper Paper18 Art 84.9 4 Art 84.9 20 20 Art 84.9 20 210 Paper Paper Paper19 Art 84.9 4 Coated 60.2 20 20 Coated 60.2 20 185 Paper Paper Paper20 Coated 60.2 4 High- 81.4 20 20 Coated 60.2 20 185 Paper Quality Paper Paper__________________________________________________________________________ Tension 1: Tension at which the first cellulosic fiber paper 1 is bonded. Tension 2: Tension at which the second cellulosic fiber paper 3 is bonded
TABLE 3______________________________________ Parts byIngredients Weight______________________________________Crosslinking 2P6A*.sup.1 3agent 2P5A*.sup.2 4 2P4A*.sup.3 3 A-DEP*.sup.4 10Polyester Resin A*.sup.5 60resin Resin B*.sup.6 20Photopolymerization 1-hydroxycyclohexyl 5initiator phenyl ketoneSilicone-base surface active agent*.sup.7 0.1Solvent methyl ethyl ketone 400 toluene 100______________________________________ *.sup.1 2P6A: dipentaerythritol hexaacrylate *.sup.2 265A: dipentaerythritol pentaacrylate *.sup.3 264A: dipentaerythritol tetraacrylate *.sup.4 A-DEP: 2,2bis (4acyloyloxy diethoxyphenyl) propane *.sup.5 Polyester resin A: Resin produced by condensing/polymerizing terephthalic acid/isophthalic acid/sebacic acid/ethylene glycol/neopentyl glycol (molecular weight: 20,000 to 25,000, Tg: 10° C.) *.sup.6 Polyester resin B: Resin produced by condensing/polymerizing terephthalic acid/isophthalic acid/sebacic acid/ethylene glycol/neopentyl glycol/1,4butane diol (molecular weight: 20,000 to 25,000, Tg: 47° C.) *.sup.7 Silicon-base surface active agent ##STR1## ##STR2##
TABLE 4______________________________________ SUB- Recording Den- Extent ofNo. STRATE sity (OD level) *.sup.1 curling *.sup.2______________________________________EXAMPLE 1 1 2.55 15EXAMPLE 2 2 2.55 11EXAMPLE 3 3 2.49 13EXAMPLE 4 4 2.53 12EXAMPLE 5 5 2.54 8EXAMPLE 6 6 2.50 10EXAMPLE 7 7 2.53 11EXAMPLE 8 8 2.55 10EXAMPLE 9 9 2.43 9EXAMPLE 10 10 2.45 10EXAMPLE 11 11 2.54 16EXAMPLE 12 12 2.55 9EXAMPLE 13 13 2.53 10EXAMPLE 14 14 2.55 10EXAMPLE 15 15 2.56 10EXAMPLE 16 16 2.57 8EXAMPLE 17 17 2.55 9EXAMPLE 18 18 2.58 8EXAMPLE 19 19 2.55 11EXAMPLE 20 20 2.57 12EXAMPLE 21 7 2.54 .sup. 11*.sup.3EXAMPLE 22 7 2.60 .sup. 7*.sup.4COMPARATIVE 21 1.86 20EXAMPLE 1COMPARATIVE 22 2.60 46EXAMPLE 2______________________________________ *.sup.1 Kyocera's thermal head (6 dots/mm) was used. The color sheet used was Mitsubishi Electric's SCTCK100TS (cyanine) Recording voltage: 13V, Pulse width: 20 ms Measurement of recording density: Macbeth optical densitometer TR927 Density of reflected light transmitted through a Status A filter was measured using TR927. *.sup.2 A black image was recorded over the entire surface of the recording medium, using a Mitsubishi Electric's video printer CP100. "Extent of curling" is the average warp height at the four corners of the recorded medium (mm) *.sup.3 Quantity of dust attached by static electricity is smaller. *.sup.4 Brighter whiteness.
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The present invention provides a recording medium for sublimation type for heat-sensitive transfer recording process which comprises laminated paper as the substrate. In this laminated paper at least two cellulosic fiber papers are bonded together by adhesive agent and one side is coated with a dye accepting layer. Therefore, the recording medium for sublimation type for heat-sensitive transfer recording process which the present invention concerns uses, as the substrate, laminated paper in which cellulosic fiber papers are bonded together. This structure almost completely prevents curling of the recorded medium and also lowers the substrate production cost to achieve a low-cost recording medium and thereby greatly contribute to the expanded use of sublimation type recording printers.
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FIELD OF THE INVENTION
[0001] The present invention is directed to the preparation of fibrous substrates, including textiles, marked with colloidal particle nanobar codes, to the fibrous substrates so prepared, and to methods for detecting the nanobar codes on the fibrous substrates for use in quality control, counterfeiting, and the like.
BACKGROUND OF THE INVENTION
[0002] It would be desirous to mark textiles and textile products for a number of reasons, including supply chain tracking, failure/liability analysis, and reduction of transshipments/grey market diversion/counterfeiting. Such marking should be easy to apply to the textile and easy to read, yet not damage or change the character of the textile nor be easy to reproduce (to avoid copying and counterfeiting).
[0003] NANOBARCODES™ particles (Nanoplex Technologies, Inc., Mountain View, Calif.) are encodeable, machine-readable, durable, nanoparticulate identification tags. These particles are disclosed in U.S. Pat. Appln. Pubin. No. US 2002/0104762 A1. The particles are manufactured in a semi-automated, highly scalable process by electroplating inert metals (such as gold, nickel, platinum, or silver) into templates that define the particle diameter, and then releasing the resulting striped nano-rods from the templates. These templates can be obtained commercially and subsequently modified, or they can be designed from scratch using lithographic processes developed by the semiconductor industry.
[0004] Just as conventional barcode is read by measuring the differential contrast between adjacent black and white lines using an optical scanner, individual NANOBARCODES particles are read by measuring the differential reflectivity between adjacent metal stripes within a single particle using a conventional optical microscope. NANOBAR™ software (Nanoplex Technologies, Inc.) then identifies which particles are present in a fraction of a second.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a process for attaching nanoscopic-sized bar codes (“nanobar codes”), such as but not limited to NANOBARCODES™ particles, to textiles and other fibrous substrates. The nanobar codes are durably attached to the fibrous substrate and further are readily identifiable for reading. More particularly, the fibrous substrates are tagged with nanobar code particles mixed with a fluorophore and a particles binder to give the treatment preparation. The particles binder of the present invention comprises a polymer, preferably a carboxyl-containing polymer or polycarboxylate; a petroleum distillate; one or more sorbitan monooleates; ammonium hydroxide; and water. It may optionally further include a resin.
[0006] The particles binder durably attaches the nanobar code particles to the fibrous substrate. The fluorophore allows identification of the location on the fabric or garment of the particles by UV fluorescence, such as by illumination under “black” light. Once the location or locations are identified, the particles are read under a microscope and interpreted with appropriate recognition software, such as the NANOBAR™ software.
[0007] The invention is further directed to fibers, yarns, fabrics, textiles, finished goods, or non-woven goods (encompassed herein under the terms “fibrous substrates”, “textiles” or “fabrics”) that have been treated with a treatment preparation comprising nanobar code particles. The particles are durably affixed to the treated fibrous substrates.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The particles binder of the present invention comprises a polymer, preferably a carboxyl-containing polymer or “polycarboxylate”; a petroleum distillate; one or more sorbitan monooleates; ammonium hydroxide; and water. It may optionally further include a resin. The binder durably attaches the nanobar code particles to the fibrous substrate. By “durably” is meant that the particles remain on the substrate for a minimum of five home launderings. The inclusion of a resin will increase the number of home launderings. In one embodiment, the particles will remain on the substrate for 10 or more, preferably for at least 25 home launderings. In another embodiment, the treatment is permanent; that is, the nanobar code particles are present for the life of the treated fibrous substrate.
[0009] In a presently preferred embodiment, the particles binder comprises from about 10 wt % to about 50 wt % of a petroleum distillate, from about 2 wt % to about 25 wt % of one or more sorbitan monooleates, from about 5 wt % to about 40 wt % of a polycarboxylate, and from about 5 wt % to about 40 wt % of ammonium hydroxide, the remainder being water. The optional resin is present in the particles binder in an amount of from 0 wt % to about 15 wt % in the particles binder.
[0010] The treatment preparation of the invention comprises the particles binder, a fluorescent dye or fluorophore, nanobar code particles, and water. In a presently preferred embodiment, the treatment preparation comprises from about 0.5 wt % to about 5 wt % of particles binder, from about 0.005 wt % to about 0.1 wt % of fluorescent dye, and from about 0.1 wt % to about 5 wt % of nanobar code particles, with the remainder being water.
[0011] The nanobar code particles are introduced onto the fibrous substrate, such as a fabric or a textile, during the finishing step in textile manufacturing. The fabric finishing step typically consists of dipping fabrics in finishing solution, padding the fabrics, and drying the fabrics in an oven. The treatment preparation containing the particles may be introduced onto the fabric using existing printing equipment, and introduction occurs after padding the fabric and before entry into the oven. Alternatively, a simple dropping device, such as those known in the art, can be utilized in place of the printing equipment.
[0012] In one embodiment, the nanobar code particles are applied to fabric in approximately 1 square centimeter dots or spots. Application of about nine such spots per square yard of fabric will ensure that all fabric and garments made from the fabric will be properly tagged. In a presently preferred embodiment, NANOBARCODES particles are used, and each spot will contain approximately 100,000 of these particles, together with the fluorescent dye marker and the particles binder, while weighing approximately 0.02 grams. During the oven process, most of that weight will evaporate due to the spots' large water composition. The remainder of the binder is composed of cellulosic paste. Thus, the total mass change per dot would be an extremely small amount of carbohydrates (on the order of 0.0004 grams, for example), minimizing any effects to the fabric (color, hand, and the like) and garment. The dot would thus be undetectable to the end consumer.
[0013] Another benefit of the present marking system is the miniscule amounts of waste it presents. Due to the sub-micron size of the NANOBARCODES particles, only minimal amounts of metal, on the order of 10 −6 grams per spot, or 10 −5 grams per square yard would be present. The NANOBARCODES particles themselves, as well as the binder, are invisible to the human eye and touch. The spots can be quickly found on the fabric by using UV fluorescence, such as a “black” light, and subsequently the pattern on the NANOBARCODES particles is read.
[0014] Readers for reading and interpreting the nanobar code particles utilize conventional microscopes and the appropriate software for reading bar codes. In the case of NANOBARCODES™ particles, NANOBAR™ software is utilized. The readers are capable of producing accurate results very quickly. The readers can simultaneously test for the presence of any or all codes. The readers can confirm the successful attachment of the particles at textile mills during initial application. They can also be used for periodic quality control during the manufacturing process. They may be further used by, for example, customs agents to authenticate that garments entering the United States are made from finished fabric made in and exported from the United States, to detect and deter the entry of grey market goods.
[0015] NANOBARCODES™ encoded particles are particularly useful in the present invention. Their small size makes them an ideal covert tag, invisible to the human eye. By varying the length and width of the stripes in the barcode, the number and type of metals used, or the number, width, and order of the stripes, libraries of thousands of uniquely identifiable particle types can be prepared. When used in combinations, the number of unique codes goes up exponentially. Because the particles are made in customizable templates, particles can be made with unique shapes and sizes that can be changed repeatedly over time. Additionally, the software that identifies the particles can be fine-tuned to accept or reject particular particle shapes and sizes, as well as particular types. Further, because the NANOBARCODES particles are made from inert metals, they are insensitive to temperature, ambient light, pH, and mechanical stress. Unlike most organic or fluorescence-based tagging systems, NANOBARCODES particles will survive stressful manufacturing or environmental conditions and still permit accurate detection and read-out.
[0016] The carboxyl-containing polymers (“polycarboxylates”) for use in the treatment preparation of the invention can be obtained through polymerization or copolymerization of one or more monomers that contain a carboxyl group, a carboxylate, or a group that can become a carboxyl or carboxylate group through a chemical reaction (a “carboxyl precursor group”). Non-limiting examples of such monomers include: acrylic acid; methacrylic acid; aspartic acid; glutamic acid; β-carboxyethyl acrylate; maleic acid; monoesters of maleic acid [ROC(O)CH═CHC(O)OH, where R represents a chemical group that is not hydrogen]; maleic anhydride; fumaric acid; monoesters of fumaric acid [ROC(O)CH═CHC(O)OH, where R represents a chemical group that is not hydrogen]; acrylic anhydride; crotonic acid; cinnamic acid; itaconic acid; itaconic anhydride; monoesters of itaconic acid [ROC(O)CH 2 (═CH 2 )C(O)OH, where R represents a chemical group that is not hydrogen]; saccharides with carboxyl (e.g. alginic acid), carboxylate, or carboxyl precursor groups; and macromonomers that contain carboxyl, carboxylate, or carboxyl precursor groups. Carboxyl precursors include, but are not limited to, acid chlorides, N-hydroxysuccinimidyl esters, amides, esters, nitriles, and anhydrides. Examples of monomers with carboxyl precursor groups include (meth)acrylate chloride, (meth)acrylamide, N-hydroxysuccinimide (meth)acrylate, (meth)acrylonitrile, asparigine, and glutamine. Herein the designation “(meth)acryl” indicates both the acryl- and methacryl-versions of the monomer. Preferred carboxylate cations include aluminum, barium, chromium, copper, iron, lead, nickel, silver, strontium, zinc, zirconium, and phosphonium (R 4 P + ). More preferred cations include hydrogen, lithium, sodium, potassium, rubidium, ammonium, calcium, and magnesium. The polymers may be linear or branched. In a presently preferred embodiment, the polymers are branched, and more preferably they have between about 0.001% and about 10% branching, inclusive. Preferred monomers are acrylic acid, methacrylic acid and β-carboxyethyl acrylate.
[0017] Acrylate polymers containing carboxyl groups are commercially available. In particular, poly(acrylic acid) is in wide production worldwide for use as a “super-absorbent” in disposable diapers and as a thickener in printing pastes. Poly(acrylic acid) can be obtained from, among other sources, Polycryl AG, Bohler, Posffach, CH-6221 Rickenbach, Switzerland (trade name: Polycryl); Stockhausen, 2401 Doyle Street, Greensboro, N.C., 27406-2911; and BFGoodrich, Four Coliseum Centre, 2730 West Tyvola Rd., Charlotte, N.C. 28217-4578 (trade name: Carbopol). The presently preferred polycarboxylate is poly(acrylic acid) (PM).
[0018] Fluorescent dyes or fluorophores are well known, and those useful in the present invention are known to those of skill in the textile arts, or can be determined without undue experimentation. Any such fluorescent dyes or fluorophores are encompassed within the present invention.
[0019] Sorbitan monooleates useful in the present invention include, but are not limited to, sorbitan monooleate, polyethylene sorbitan monooleate, and polyoxyethylene sorbitan monooleate.
[0020] A resin is optionally included in the particles binder to further increase the durability of the nanobar codes particles on the fibrous substrate. Resins useful in the present invention are known to those of skill in the textiles art or may be determined without undue experimentation and include, but are not limited to, the following crosslinking moieties: isocyanates, epoxides, divinylsulfones, aldehydes, chlorohydrins, N-methylol compounds, and polycarboxylic acids. Of these, N-methylol compounds are the most useful. Examples include dimethylol urea, dimethylol ethylene urea, trimethylol trazine, dimethylol methyl carbamate, uron, triazone, and dimethylol dihydroxy ethylene urea.
[0021] Other binders, for example those used in the paper and textile industries, may be employed as the particles binder in the present invention by one skilled in the art.
[0022] The invention is further directed to fibrous substrates treated with the treatment preparation comprising nanobar code particles. These treated fibrous substrates can be used in a variety of ways including, but not limited to, the following: clothing, upholstery and other interior furnishings, hospital and other medical uses, and industrial uses. The Wellington Sears Handbook of Industrial Textiles (Ed. S. Adanur, Technomic Publishing Co., Lancaster, Pa., 1995, p. 8-11) lists a number of potential uses.
[0023] The fibrous substrates of the present invention are intended to include fibers, fabrics and textiles, and may be sheet-like structures (woven, knitted, tufted, stitch-bonded, or non-woven) comprised of fibers or structural elements. Included with the fibers can be non-fibrous elements, such as particulate fillers, binders, and sizes. The textiles or webs include fibers, woven and non-woven fabrics derived from natural or synthetic fibers or blends of such fibers. They can comprise fibers in the form of continuous or discontinuous monofilaments, multifilaments, staple fibers, and yarns containing such filaments and/or fibers, which fibers can be of any desired composition. Mixtures of natural fibers and synthetic fibers may also be used. Examples of natural fibers include cotton, wool, silk, jute, and linen. Examples of man-made fibers include regenerated cellulose rayon, cellulose acetate, and regenerated proteins. Examples of synthetic fibers include, but are not limited to, polyesters (including polyethyleneterephthalate and polypropyleneterephthalate), polyamides (including nylon), acrylics, olefins, aramids, azions, modacrylics, novoloids, nytrils, aramids, spandex, vinyl polymers and copolymers, vinal, vinyon, vinylon, Nomex® (DuPont) and Kevlar® (DuPont).
EXAMPLES
Example 1
Preparation of a Particles Binder
[0024] 25 Weight percent Isopar M petroleum distillate (ExxonMobil Chemical), 3.7 wt % Span 80 sorbitan monooleate, 7.5 wt % Tween 80 polyoxyethylene(20) sorbitan monooleate, 15 wt % Carbopol 846 poly(acrylic acid) [viscosity cP (% solids)=35000 (0.35); Noveon, Inc.], 15 wt % ammonium hydroxide, and 33.8 wt % water were added together and mixed to form a binder for nanobar code particles.
Example 2
Preparation of Nanobar Code Particles Printing Paste (Treatment Preparation)
[0025] 2 Weight percent of the particles binder from Example 1, 0.0225 wt % fluorescent dye, and 1 wt % NANOBARCODES™ particles (1 billion bars per gram of NANOBARCODES) were added to 97.9775 wt % water and mixed together to give the treatment preparation for use as a printing paste for application to a fibrous substrate.
Example 3
[0026] The printing paste from Example 2 was applied to a fabric as follows:
[0027] A thin coat of the printing paste was placed on the end of a 1 cm diameter stainless steel rod. The end of the rod was touched to fabric to transfer the paste onto the fabric. The approximate mass of wet printing paste transferred (wet pickup) is 20 mg. The treated fabric was then dried in an oven at 100° C. for 5 minutes.
[0028] The locations of the NANOBARCODES particles were detected by black (UV) light. The printing paste was placed on a wide variety of colored backgrounds, including black, browns and greens, and the NANOBARCODES particles could be read from all of these.
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The present invention is directed to the preparation of fibrous substrates, including textiles, marked with colloidal particle nanobar codes, to the fibrous substrates so prepared, and to methods for detecting the nanobar codes on the fibrous substrates for use in quality control, counterfeiting, and the like.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 11/194,360 filed on Aug. 1, 2005, now U.S. Pat. No. 7,345,824, which is a continuation-in-part of U.S. application Ser. No. 10/108,296 filed on Mar. 26, 2002, now abandoned, a continuation-in-part of U.S. application Ser. No. 10/688,785 filed on Oct. 17, 2003, now U.S. Pat. No. 7,428,367, and claims the benefit of priority of U.S. Provisional Application No. 60/600,272 filed on Aug. 10, 2004.
FIELD OF INVENTION
The present application relates to both (1) transflective structures and (2) light collimating structures. In particular, the present application relates to a method of making a reflective layer for transflective films and light collimating films.
BACKGROUND
Light collimating films, sometimes known as light control films, are known in the art. Such films typically have opaque plastic louvers lying between strips of clear plastic. U.S. Pat. No. Re 27,617 teaches a process of making such a louvered light collimating film by skiving a billet of alternating layers of plastic having relatively low and relatively high optical densities. After skiving, the high optical density layers provide light collimating louver elements which, as illustrated in the patent, may extend orthogonally to the surface of the resulting louvered plastic film. U.S. Pat. No. 3,707,416 discloses a process whereby the louver elements may be canted with respect to the surface of the light collimating film. U.S. Pat. No. 3,919,559 teaches a process for attaining a gradual change in the angle of cant of successive louver elements.
Such light collimating films have many uses. U.S. Pat. No. 3,791,722 teaches the use of such films in lenses for goggles to be worn where high levels of illumination or glare are encountered. Such films also may be used to cover a backlit instrument panel, such as the dashboard of a car, to prevent undesired reflections in locations such as the windshield, or a backlit electronic device (e.g., a LCD computer screen or LCD TV).
U.S. Pat. No. 5,204,160 discloses light collimating films that are formed from a plastic film with a series of grooves formed therein. The grooves are filled with a light absorbing material or the sides and bottoms of the grooves may be painted with a light absorbing ink.
U.S. Patent Application Publication No. 2005/0259198 discloses light collimating devices and transflecting devices that include a layer having a plurality of three dimensional optical elements and a reflective layer. The reflective layer has apertures corresponding to the position and shape of the ends of the three dimensional optical elements.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, structures are illustrated that, together with the detailed description provided below, describe exemplary embodiments of the claimed invention.
In the drawings and description that follows, like elements are identified with the same reference numerals. The drawings are not to scale and the proportion of certain elements may be exaggerated for the purpose of illustration.
FIG. 1 is a depiction of a vertical plane cross-section of one embodiment of an optical element;
FIG. 2 is a three-dimensional depiction of another embodiment of an optical element;
FIG. 3 is a three-dimensional depiction of one embodiment of an array of optical elements defined by cross channels;
FIG. 4 is a three-dimensional depiction of one embodiment of an array of optical elements defined by lenticular channels;
FIGS. 5A and 5B are a perspective view and an exploded perspective view, respectively, of one embodiment of a light collimating device;
FIGS. 6A and 6B are vertical plane cross-sections of one embodiment of a light manipulating device;
FIG. 7 is a front plan view of one embodiment of a micro-milling tool;
FIG. 8 is a front plan view of an alternative embodiment of a micro-milling tool;
FIG. 9 is a vertical plane cross-section of an alternative embodiment of a light manipulating device having a first and second immersion layer;
FIG. 10 is a vertical plane cross-section of an alternative embodiment of a light manipulating device having a spacing layer;
FIG. 11 is a vertical plane cross-section of an alternative embodiment of a light manipulating device with no immersion layer;
FIGS. 12A and 12B are vertical plane cross-sections of alternative embodiments of a light manipulating device;
FIG. 13 is a three-dimensional depiction of one embodiment of an array of optical elements defined by lenticular channels and having additional shallow cuts in a top surface;
FIG. 14 is a simplified side view of one embodiment of a light collimating assembly;
FIG. 15 is a simplified side view of an alternative embodiment of a light collimating assembly;
FIG. 16 is a simplified side view of one embodiment of a light transflecting sub-assembly;
FIG. 17 is a simplified side view of an alternative embodiment of a light transflecting sub-assembly;
FIG. 18 is a simplified side view of one embodiment of a light transflecting and collimating sub-assembly; and
FIG. 19 is a simplified side view of an alternative embodiment of a light transflecting and collimating sub-assembly.
DETAILED DESCRIPTION
The following includes definitions of selected terms employed herein. The definitions include various examples and/or forms of components that fall within the scope of a term and that may be used for implementation. The examples are not intended to be limiting. Both singular and plural forms of terms may be within the definitions.
“Horizontal plane cross-section” as used herein, refers to a cross-section taken along a plane perpendicular to the direction in which light travels through the element.
“Tapered” as used herein, refers to a narrowing along either a linear or curved line in the vertical plane cross-section direction, such that horizontal plane cross-sections taken at different locations will have different areas. In other words, a tapered object will have a small area end and a large area end.
“Vertical plane cross-section” as used herein, refers to a cross-section taken along a plane parallel to the direction in which light travels through the element.
The present application relates to both (1) transflective devices and (2) light collimating devices. Light collimation is defined as taking the given angular distribution of a light source and increasing the peak intensity, which may be on-axis, by the process of narrowing that given angular distribution.
Light collimating effects can be accomplished by using an optical layer formed by a series of discrete tapered optical elements in combination with a reflecting layer having openings or apertures disposed therein, corresponding to the position and shape of the tapered ends of the optical elements. To perform a light collimating function, the optical element is tapered towards a light source, such that the optical element has a large area end and a small area end. In a light collimating device, the small area ends are light input ends and the large area ends are light output ends.
Transflecting devices and collimating devices are more fully described in U.S. patent application Ser. No. 11/194,360 (“the '360 application”), now published as U.S. Publication No. 2005/0259198 and incorporated herein by reference. The '360 application discloses light collimating devices and transflecting devices that include a layer having a plurality of three dimensional optical elements and a reflective layer. The reflective layer has apertures corresponding to the position and shape of the ends of the three dimensional optical elements. The present application discusses methods for making the three dimensional optical elements and aligning the optical elements with the apertures of the reflective layer.
FIG. 1 illustrates a vertical plane cross-section of one embodiment of an optical element 100 . The optical element 100 may be used as part of a light collimating device or as part of transflecting device. The optical element 100 includes a tapered end 110 and a broad end 120 . The optical element further includes sidewalls 130 configured to reflect and/or guide light. In the illustrated embodiment, the sidewalls are curved. The curved lines may be parabolic, circular, or defined by other known curves, or a combination thereof. In alternative embodiments, the sidewalls may be defined by straight lines or a plurality of straight and curved lines.
In one embodiment, light L enters the optical element 100 at one end and exits from the opposite end. Some light rays L strike the sidewalls 130 and are reflected. Other light rays (not shown) pass directly through the optical element 100 without striking a sidewall 130 .
When the optical element 100 is used as a collimator, light L enters the optical element 100 at the narrow end 110 from multiple directions. As the light L travels through the optical element 100 , it may impinge on the sidewall 130 . The sidewall 130 reflects the light L and focuses it an angle such that the light L emerges from the broad end 120 as a substantially uniform sheet.
When the optical element 100 is used as a transflector, light from a first source enters the optical element 100 at the broad end 120 . As the light travels through the optical element 100 , it may impinge on the sidewall 130 . The sidewall 130 reflects the light such that it emerges from the tapered end 110 . As is described more fully below and in the '360 application, the optical element is used in combination with a reflective layer that reflects light traveling from a second source opposite the first source.
FIG. 2 illustrates a perspective view of one embodiment of an optical element 200 having a tapered end 210 and a broad end 220 . In this embodiment, the optical element is a discrete post and the tapered end 210 is a flat square. The broad end 220 of the optical element 200 is also square and the optical element has a square horizontal plane cross-section. In other embodiments (not shown), the ends and the horizontal plane cross-section may be a circle, a rectangle, or any curved or polygonal shape.
FIG. 3 illustrates one embodiment of an optical element array 300 (also referred to as an optical element layer). The illustrated optical element array is an exemplary 10×10 array of optical elements having square horizontal plane cross-sections, such as the optical element 200 illustrated in FIG. 2 . In other embodiments, an optical element array can be of any desired size or include any desired number or arrangement of optical elements. As shown, the square cross-section allows for a high packing density of optical elements. As will be explained in more detail below, in one embodiment the optical element array 300 is made by micro-milling a first set of substantially parallel lenticular channels, then micro-milling a second set of substantially parallel lenticular channels that are substantially perpendicular to the first set of lenticular channels.
FIG. 4 illustrates an alternative embodiment of an optical element array 400 . In this embodiment, a plurality of optical elements 410 are defined by a plurality of lenticular channels 420 . The lenticular channels are substantially parallel to each other. In one embodiment, the lenticular channels 420 are formed by micro-milling.
FIGS. 5A and 5B show exploded and assembled views, respectively, of a light collimating device that includes a light manipulating device 500 . The light manipulating device 500 includes an optical element layer 510 and a reflecting layer 520 . In the illustrated embodiment, the reflecting layer 520 is formed on an immersing layer 530 . In the illustrated embodiment, the optical element layer 510 is an array of optical elements formed by cross-channels, such as the optical element array 300 shown in FIG. 3 . In an alternative embodiment, the optical elements of the optical element layer are formed by lenticular channels, such as the optical element array 400 shown in FIG. 4 .
The reflecting layer 520 includes apertures (or openings) 540 which match the tapered ends of optical elements in the optical element layer 510 . In the illustrated embodiment, the apertures 540 are square shaped to correspond with square-shaped tapered ends of the optical elements. In alternative embodiments (not shown), the apertures are polygonal, circular, or any combination of curved and/or straight lines that correspond to the shape of the tapered ends of the optical elements. For example, in the case of optical elements formed by lenticular channels, the apertures of the reflecting layer would be elongated rectangles.
In one embodiment, the reflecting layer 520 is constructed of metal, such as nickel, gold, aluminum, silver, or other suitable metal. In other embodiments (not shown), the reflecting layer may be constructed of any reflecting substance.
Also shown in FIGS. 5A and 5B is a backlight B (such as one used in a LCD TV) having a surface S that simultaneously acts as an emitting and reflecting surface. Those familiar with the state of the art will recognize that this is a standard feature in LCD backlights. The reflecting feature allows for light recycling, a property that enhances performance. In the illustrated embodiment, the tapered ends of the optical elements are facing the backlight B, and thus light manipulating device 500 acts as a light collimator. As will be described further below, if the light manipulating device 500 is reversed, it acts as a transflector.
FIG. 6A illustrates a vertical plane cross-sectional view of one embodiment of the light manipulating device 600 . In the illustrated embodiment, the light manipulating device 600 includes an optical element layer 610 having a plurality of optical elements 620 . Each optical element 620 has a tapered end 630 and a broad end 635 . The tapered end 630 has a width W e and the broad end 635 has a width W 0 . In one embodiment, the width W e of the tapered end 630 and/or the width W 0 of the broad end 635 are pre-selected. In another embodiment, described in more detail below, other dimensions are pre-selected and the width W e of the tapered end 630 and/or the width W 0 of the broad end 635 are a function of those dimensions. In one embodiment, the width W e of the tapered end 630 is selected to be 5 μm. In alternative embodiments, the width W e of the tapered end 630 may be any dimension.
The optical elements 620 are defined by a plurality of channels 640 . Each channel has a bottom surface 650 and a pair of sidewalls 660 . In one embodiment, the channels 640 are formed by micro-milling. In the illustrated embodiment, the optical elements 620 may be formed by cross-channels, forming an array such as shown in FIG. 3 or the optical elements 620 may be formed by lenticular channels, forming an array such as shown in FIG. 4 . In one embodiment, the optical elements are formed by micro-milling a plurality of substantially parallel channels 640 by a tool.
FIG. 7 illustrates a front plan view of one embodiment of a tool 700 for micro-milling channels. In one embodiment, the tool has a bit 710 with a tip 720 . In one embodiment, the tool bit 710 is a diamond tool bit. In one embodiment, the tool bit 710 has a width W t and a sidewall 730 having a shape defined by the equation:
( x+k 1 ) 2 +( y+k 2 ) 2 =( k 3 ) 2 (1)
here x is the horizontal distance from a predetermined point external to the bit 710 and y is the vertical distance measured from the tip 720 . For exemplary purposes, the X-Y axes defining the curve of the bit 710 are as shown in FIG. 7 . In one embodiment, k 1 =596.2 μm, k 2 =3.8 μm, and k 3 =622.26 μm. All dimensions are cited in microns for convenience. In alternative embodiments, other dimensions may be used.
In an alternative embodiment, the above selected k values are scaled proportionally upwards. In one known embodiment, the k values are scaled proportionally upwards by a factor of 5 or less. In another alternative embodiment, the above selected k values are scaled proportionally downwards. In one known embodiment, the k values are scaled proportionally downwards by a factor of 5 or less. In an alternative embodiment, other values may be selected for k 1 , k 2 , and k 3 .
In one embodiment, the bit 710 has a circular horizontal plane cross-section. In this embodiment, the sidewalls 730 of the drill bit are symmetrical about a central radius. In an alternative embodiment, the bit 710 has a polygonal horizontal plane cross-section.
FIG. 8 illustrates an alternative embodiment of a tool bit 810 . In the illustrated embodiment, the tool bit 810 has a main body portion 820 having curved sidewalls. In one embodiment, the curved sidewalls are defined by equation (1) above.
In the illustrated embodiment, the tool bit 810 further includes a lower linear end 830 and an upper linear end 840 . The lower and upper linear ends 830 , 840 each have sidewalls defined by a straight line. Linear ends limit the vertical angle of the sidewall, which has manufacturing benefits. In an alternative embodiment (not shown) the tool bit includes a lower linear end, but not an upper linear end. In another alternative embodiment, the tool bit includes an upper linear end, but not a lower linear end.
In one embodiment, the bit 810 has a circular horizontal plane cross-section. In this embodiment, the sidewalls of the drill bit are symmetrical about a central radius. In an alternative embodiment, the bit 810 has a polygonal horizontal plane cross-section.
Returning to the light manipulating device 600 of FIG. 6A , the channels 640 , when milled with the tool 700 , will have the same dimensions as the tool 700 . In other words, the bottom surface 650 of the channel 640 will have a width equal to the width W t of the tip 710 and each sidewall 660 will be a curve defined by equation (1) above.
In this embodiment, the origin of the X-Y axes is shown at the center of the broad end 635 of an optical element 620 . We may refer to the left and right sidewalls 660 of an optical element 620 , rather than refer to the sidewalls of a channel. It should be understood that an optical element may include more than a left and right sidewall. The number of sidewalls of an optical element is determined by the shape of the horizontal plane cross-section of the element.
Under the above stated conventions, we may use a modified equation (1) to define both the left and right sidewalls 660 of an optical element 620 . Equation (1) may be modified as such:
(| x|+k 1 ) 2 +( y+k 2 ) 2 =( k 3 ) 2 (2)
This modification expresses the symmetry of the optical elements 620 about the Y-axis. As with the tool, in one embodiment, W t =2.5 μm, k 1 =596.2 μm, k 2 =3.8 μm, and k 3 =622.26 μm.
In an alternative embodiment, the above selected k values are scaled proportionally upwards. In one known embodiment, the k values are scaled proportionally upwards by a factor of 5 or less. In another alternative embodiment, the above selected k values are scaled proportionally downwards. In one known embodiment, the k values are scaled proportionally downwards by a factor of 5 or less. In an alternative embodiment, other values may be selected for k 1 , k 2 , and k 3 .
As shown in FIG. 6A , the channel 640 has a depth defined as y d . At the top of the sidewall 660 , x has a value defined as x d (or −x d ). The width of the tapered end W e of the optical element 620 is therefore defined as:
W e =2x d (3)
With continued reference to FIG. 6A , at the bottom of the sidewall 660 , y=0 and x has a value defined as x 0 (or −x 0 ). The width W 0 of the optical element 620 at the broad end 635 is therefore defined as:
W 0 =2x 0 (4)
In one embodiment, the channels 640 are micro-milled such that the optical elements 620 form a regular array having a periodicity P. The periodicity P is defined as the horizontal distance between any point on an optical element, and an identical point on the adjacent optical element. In FIG. 6A , the periodicity P is shown as measured from the right side of the broad end 635 of an optical element 620 to the right side of the broad end of the adjacent optical element. It should be understood that because the optical elements 620 have substantially the same dimensions and are arranged in a regular array, the periodicity P is constant, no matter what point is chosen as a measuring point.
When P is measured from the right side of the broad end 635 of an optical element 620 as described above, it follows that:
P=W t +W 0 (5)
Substituting equation (4) into equation (5), it follows that:
P=W t +2 x 0 (6)
As can be seen from above, the periodicity P, the width W t of the channel 640 (or the width of the tip 710 of the tool 700 ), the half-width x 0 of the broad end 635 (or the width W 0 of the broad end 635 ), the half-width x d of the tapered end 630 of the optical element 620 (or the width W e of the tapered end 630 of the optical element 620 ), and the depth y d of the channel 640 are all dependent variables. In one embodiment the width W t of the channel 640 , the half-width x 0 of the broad end 635 , and the half-width x d of the tapered end 630 of the optical element 620 are pre-selected. Additionally, in one embodiment, the width W t of the channel 640 is selected as 2.5 μm, the half-width x 0 of the broad end 635 is selected as 26.05 μm, and the half-width x d of the tapered end 630 of the optical element 620 is selected as 2.5 cm. In this embodiment, from equation (6) it follows that the periodicity P is 54.6 μm. Further, it follows from equation (2), when k 1 =596.2 μm, k 2 =3.8 μm, and k 3 =622.26 μm, then the depth y d of the channel 640 is 165.8 μm.
In alternative embodiments, other values for the constants and the dependent values may be selected. In another alternative embodiment, the depth of the channels and/or the periodicity may be pre-selected in combination with other dependent variables. In such an embodiment, the remaining dependent variables could be determined based on equations (2)-(6).
After the optical elements 620 are formed in the optical element layer 610 of the light manipulating device 600 , a separate reflective layer 670 is formed. In one embodiment, the reflective layer 670 is less than 1 μm. In one known embodiment, the reflective layer 670 is thinner than 0.2 μm, just sufficient thickness and optical density to maximize reflectivity. FIG. 6A shows the reflective layer 670 separate from the optical element layer 610 to show that the reflective layer 670 may be formed separately before it is combined with the optical element layer 610 .
In one embodiment, the reflective layer 670 is formed on an immersion layer 680 . In one embodiment, the reflective layer 670 is formed directly on the immersion layer 680 by a sputtering process. In alternative embodiment, the reflective layer 670 is formed directly on the immersion layer 680 by a chemical vapor deposition process or any other known forming process. In another alternative embodiment, the reflective layer 670 is a thin, solid layer of reflecting material formed by a rolling process.
In one embodiment, after the reflective layer 670 is formed, it is placed in contact with the tapered ends 630 of the optical elements 620 of the optical element layer 610 . Then, a combination of heat and/or pressure of sufficient amounts is used to puncture the optical elements 620 through the reflective layer 670 , pushing aside portions of the reflective layer 670 that block or partially block either the sidewall 660 or the tapered end 630 of the optical element layer 610 , as shown in FIG. 6B .
In this embodiment, the result is a light manipulating device 600 that (1) reflects light where the reflective layer 670 is intact and (2) transmits light through the optical elements 620 where the optical elements 620 have punctured the reflective layer 670 .
In the embodiment illustrated in FIG. 6B , the reflective layer 670 is disposed on an immersion layer 680 . Because the reflective layer 670 is thin, the immersion layer 680 provides stability to and helps maintain the integrity of the reflective layer 670 during the piercing process. The immersion layer 680 is softer than the optical elements 620 . In one embodiment, the immersion layer 680 is a polymer film. In one embodiment, the immersion layer 680 is a pressure sensitive adhesive (PSA). In an alternative embodiment, the immersion layer 680 is a polymer with a low glass transition temperature (T g ) or a polymer that could be hardened after penetration by exposure to, for example, UV light.
In one embodiment the immersion layer 680 has an index of refraction equal to that of the optical element layer 610 . In another embodiment, the immersion layer 680 has an index of refraction lower than that of the optical element layer 610 . In yet another embodiment, the immersion layer 680 has an index of refraction higher than that of the optical element layer 610 . It should be understood that both the optical element layer 610 and the immersion layer 680 are light transmitting layers.
With continued reference to FIG. 6B , the optical elements 620 puncture the reflective layer 670 and extend through the combined reflective layer 670 and into the immersion layer 680 a specified distance, defined as the penetration depth D. In the illustrated embodiment, the reflective layer 670 is located a vertical distance y r above the bottom surface 650 of the channel 640 . This vertical distance y r may be any distance less than the depth y d of the channel 640 . Once the vertical distance y r is selected, a corresponding half-width x r of the optical element 620 at y r can be determined from equation (2). In one embodiment, the vertical distance y r is selected as 150 μm. From equation (2), when k 1 =596.2 μm, k 2 =3.8 μm, and k 3 =622.26 μm, it follows that the corresponding half-width x r of the optical element 620 is 6.75 cm.
Additionally, a width W a of the aperture of the reflective layer 670 can be determined. The width W a of the aperture is defined as:
W a =2x r (7)
Therefore, when the half-width x r of the optical element 620 at y r is 6.75 μm, it follows that the width W a of the aperture of the reflective layer 670 is 13.5 μm.
In one embodiment, the combined thickness of the reflective layer 670 and the immersion layer 680 exceeds the penetration depth D of the optical element 620 . In an alternative embodiment, the combined thickness of the reflective layer 670 and the immersion layer 680 does not exceed the penetration depth D of the optical elements 620 . In other words, in this embodiment, the tapered ends 630 of the optical elements 620 extend beyond the immersion layer 680 . The thickness of the immersion layer is limited only by manufacturing constraints of total penetration depth.
FIG. 9 illustrates a vertical plane cross-section of an alternative embodiment of a light manipulating device 900 having an optical element layer 910 and a reflective layer 920 . In the illustrated embodiment, an immersion layer 930 includes a first immersion layer 940 disposed on the reflective layer 920 and second immersion layer 950 disposed on the first immersion layer 940 , opposite the reflective layer 920 . In this embodiment, the first immersion layer 940 is softer than the optical element layer 910 , thereby facilitating penetration of the optical element layer 910 into the first immersion layer 940 . The second immersion layer 950 is constructed of a material sufficiently hard to stop the penetration. In one embodiment the second immersion layer 950 is as hard as the optical element layer 910 . In an alternative embodiment, the second immersion layer 950 is harder than the optical element layer 910 . In these embodiments, the thickness of the first immersion layer 940 is equal to the penetration depth of the optical element layer 910 .
FIG. 10 illustrates a vertical plane cross-section of an alternative embodiment of a light manipulating device 1000 having an optical element layer 1010 . In the illustrated embodiment, the light manipulating device 1000 includes a reflective layer 1020 and an immersion layer 1030 , similar to the reflective layer 670 and immersion layer 680 of the light manipulating device 600 illustrated in FIG. 6 . In an alternative embodiment (not shown), the light manipulating device includes a first and second immersion layer, similar to the light manipulating device 900 illustrated in FIG. 9 .
With continued reference to FIG. 10 , the light manipulating device further includes a spacing layer 1040 disposed on the reflective layer 1020 on the side opposite the immersion layer 1030 . The spacing layer 1040 assists in pushing aside the reflective layer to maintain the integrity of the reflective layer 1020 during the piercing process. In one embodiment the spacing layer 1040 is constructed of a polymer. In one specific embodiment, the spacing layer 1040 is constructed of the polymer used to construct the immersion layer 1030 .
In one embodiment, the spacing layer 1040 has an index of refraction lower than that of the optical element layer 1010 . In one known embodiment, the spacing layer 1040 has an index of refraction sufficiently lower than the optical element layer 1010 such that total internal reflection occurs inside the optical element layer 1010 .
In one embodiment, the optical element layer 1010 , the immersion layer 1030 , and the spacing layer 1040 are all light transmitting layers. In an alternative embodiment, the spacing layer 1040 is not a light transmitting layer.
In one embodiment, the combined thickness of the reflective layer 1020 , the immersion layer 1030 , and the spacing layer 1040 exceeds the penetration depth D of the optical element layer 1010 . In an alternative embodiment, the combined thickness of the reflective layer 1020 , the immersion layer 1030 , and the spacing layer 1040 does not exceed the penetration depth D of the optical element layer 1010 . In other words, in this embodiment, the tapered ends of the optical elements in the optical element layer 1010 extend beyond the immersion layer 1030 . In all embodiments, the penetration depth exceeds the combined thickness of the reflective layer 1020 and the spacing layer 1040 . If the penetration depth did not exceed this combined thickness, the reflective layer 1020 would not be pierced.
FIG. 11 illustrates a vertical plane cross-section of an alternative embodiment of a light manipulating device 1100 having an optical element layer 1110 . In the illustrated embodiment, a reflective layer 1120 is disposed on a spacing layer 1130 . The optical element layer 1110 then punctures the combined reflective layer 1120 and spacing layer 1130 , such as described with relation to FIGS. 6A and 6B .
In one embodiment, the light manipulating device 1100 is employed as illustrated in FIG. 11 . In an alternative embodiment, an immersion layer (not shown) is added to the device 1100 , such that the device resembles the light manipulating device 1000 illustrated in FIG. 10 . The immersion layer may be a liquid polymer that is poured on the device 1100 and then hardens, a semi-solid polymer that is formed around the ends of the optical element layer 1110 , or a solid polymer that is preformed to cover both the optical element layer 1110 and the reflective layer 1120 .
In one embodiment, the spacing layer 1130 has an index of refraction lower than that of the optical element layer 1110 . In one known embodiment, the spacing layer 1130 has an index of refraction sufficiently lower than the optical element layer 1110 such that total internal reflection occurs inside the optical element layer 1110 .
In one embodiment, the optical element layer 1110 and the spacing layer 1130 are both light transmitting layers. In an alternative embodiment, the spacing layer 1130 is not a light transmitting layer.
FIG. 12A illustrates a vertical plane cross-section of an alternative embodiment of a light manipulating device 1200 having an optical element layer 1210 . In the illustrated embodiment, a reflective layer 1220 is disposed between an immersion layer 1230 and a spacing layer 1240 . The optical element layer 1210 then punctures the combined reflective layer 1220 , immersion layer 1230 , and spacing layer 1240 , such that the tapered ends of the optical elements extend beyond the immersion layer 1230 and are exposed.
In one embodiment, the light manipulating device 1200 is employed as illustrated in FIG. 12A . In an alternative embodiment, a second immersion layer 1250 is added to the device 1200 , such as illustrated in FIG. 12B . The second immersion layer 1250 may be a liquid polymer that is poured on the device 1200 and then hardens, or it may be a solid polymer that is preformed to cover both the optical element layer 1210 and the immersion layer 1230 . In one embodiment, the second immersion layer 1250 has the same index of refraction as the immersion layer 1230 . In an alternative embodiment, the second immersion layer 1250 has a different index of refraction from the immersion layer 1230 .
In one embodiment, the spacing layer 1240 has an index of refraction lower than that of the optical element layer 1210 . In one known embodiment, the spacing layer 1240 has an index of refraction sufficiently lower than the optical element layer 1210 such that total internal reflection occurs inside the optical element layer 1210 .
In one embodiment, the optical element layer 1210 and the spacing layer 1240 are both light transmitting layers. In an alternative embodiment, the spacing layer 1240 is not a light transmitting layer.
While the above descriptions applies to both arrays of optical elements formed by cross-channels (such as the array 300 illustrated in FIG. 3 ) and arrays of optical elements formed by lenticular channels (such as the array 400 illustrated in FIG. 4 ), in one embodiment, additional steps may be taken with arrays formed by lenticular channels to aid in the piercing of a reflective layer. As is understood in the art, a smaller surface area is more effective at piercing an object. Therefore, FIG. 13 illustrates an array 1300 of optical elements 1310 defined by lenticular channels 1320 , wherein the optical elements 1310 further include shallow cross cuts 1330 defining square tops 1340 . A common term to describe this shallow cross cut is “nicking”. In alternative embodiments, the cross cuts define circular or polygonal tops or any top defined by curved and/or straight lines.
In one embodiment, the periodicity and depth of the cross cuts 1330 are calculated such that the piercing process will not leave unpierced regions in the remainder of the channel while simultaneously totally penetrating the immersion layer and the reflective layer. Unpierced regions are undesirable because they act as dead spots in the collimating device. An appropriate choice of these parameters allows the use of the piercing technique for manufacturing the reflective layer in a lenticular-channeled device.
With continued reference to FIG. 13 , the cross cuts 1330 in the optical elements 1310 define a plurality of 5 μm square tops 1340 . In order for the cross cut region of the lenticular channels to penetrate the reflective layer, the vertical distance y c between the base of the cross cut 1330 and the bottom surface of the lenticular channel 1320 must be greater than the vertical distance y r between the reflective layer (as shown in FIG. 6 ) and the bottom surface of the lenticular channel 1320 :
y c >y r (8)
In one embodiment, the lenticular channel 1320 has a depth y d of 165.8 μm, the vertical distance y r between the reflective layer (not shown) and the bottom surface of the lenticular channel 1320 is 150 μm, and the vertical distance y c between the bottom surface of the cross cut 1330 and the bottom surface of the lenticular channel 1320 is 160.8 μm. Further, instead of defining the vertical distance y c between the bottom surface of the cross cut 1330 and the bottom surface of the lenticular channel 1320 , we may define a nicking depth D n as the vertical distance from the bottom surface of the cross cut 1330 to the top surface of an optical element 1310 . In alternative embodiments, other values of y r and y c may be used.
In one embodiment, a cross cut of 1330 having a vertical depth of 160.8 μm relative to the cross channel 1330 is formed by using the tool 700 of FIG. 7 at a depth 5 μm from the tip 720 of the bit 710 . In other words, the cross cut 1330 has a nicking depth D n of 5 μm. To determine the periodicity of the cross cuts 1330 , the width of the tool at the nicking depth D n must be calculated. The width of the tool at a specified distance above the tip 720 can be determined since the change in width is simply twice the difference in the values of x from the tip 720 to the nicking depth D n of the cross cut 1330 . The difference between the two values of x can be calculated by substituting the values of y into equation (2) and subtracting the results. This difference when added to the width of the tool 700 at the tip 710 is equal to the width of the tool at the nicking depth D n . Therefore, when the nicking depth D n is 5 μm, the two values of x are 26.05 μm and 26.0 μm. Thus the width of the of the cross cut 1330 at the top of the optical element 1320 is 5.1 μm. Accordingly, the cross cuts 1330 have a periodicity 10.1 μm when the depth of cut is 5 μm.
In another embodiment a tool of different shape. For example, the edge of the tool could be chosen to optimize the edge of the penetrator shape that is orthogonal to the channel in the lenticular design.
While the processes described thus far are directed to a method for micro-milling an optical element array, it should be understood that in manufacturing, other methods of making an optical element array may be employed. In one embodiment, the above described process is used to manufacture a master array. The master array is then used to create a negative mold. The negative mold may be used as an impact mold, an injection mold, or a blow mold to form optical element arrays. The master array may be constructed of metal, a hard polymer, or other known material of sufficient hardness to create a negative mold. Similarly, the negative mold may be constructed of metal, a hard polymer, or other known material.
In one embodiment, the negative mold is used to form a second master. The second master is then used to form a second negative mold. The second negative mold may be used as an impact mold, an injection mold, or a blow mold to form optical element arrays. In an alternative embodiment, the process is repeated for several generations and the final negative mold may be used as an impact mold, an injection mold, or a blow mold to form optical element arrays.
In an alternative embodiment, the optical element layer is formed by an electroforming process. In another alternative embodiment, a negative mold is formed by an electroforming process.
FIGS. 14-17 illustrate light manipulating devices, such as those illustrated in FIGS. 6 and 9 - 13 , in use as a collimator or transflector.
FIG. 14 illustrates a collimating device 1400 positioned adjacent a backlight B. The collimating device 1400 is one of a light manipulating device 600 , 900 , 1000 , 1100 , 1200 , or 1300 as shown in FIGS. 6 and 9 - 13 . The collimating device 1400 includes a reflecting layer having apertures formed therein to both transmit light from the backlight B and recycle light back to the backlight B. In this embodiment, the reflecting layer is formed on the side of an immersing layer facing an optical element layer. A more detailed description of collimators is included in the '360 application and is incorporated herein by reference.
In one embodiment, the collimating device 1400 is optically coupled to the backlight B, thereby creating a sub-assembly with no air gaps between the collimating device 1400 and the backlight B. Optically coupling the elements eliminates unwanted loss of light. In an alternative embodiment (not shown), for manufacturing purposes, the collimating device 1400 is positioned adjacent the backlight B such that there is an air gap.
FIG. 15 illustrates an alternative embodiment of a collimating assembly 1500 . In this embodiment, a diffusing layer 1510 is positioned between a collimating device 1520 and a backlight B. In one embodiment, one side the diffusing layer 1510 is optically coupled to the collimating device 1520 and the opposite side of the diffusing layer 1510 is optically coupled to the backlight B, thereby creating an assembly 1600 with no air gaps. In an alternative embodiment (not shown), the diffusing layer 1510 is positioned between the collimating device 1520 and the backlight B such that air gaps exist.
FIG. 16 illustrates a transflective device 1600 positioned between a backlight B and an ambient light source A. The transflective device 1600 is one of a light manipulating device 600 , 900 , 1000 , 1100 , 1200 , or 1300 as shown in FIGS. 6 and 9 - 13 . The transflective device 1600 includes a reflecting layer having apertures formed therein to transmit light from the backlight B while reflecting light from the ambient light source A. In this embodiment, the reflecting layer is formed on the side of an immersing layer facing an optical element layer. A more detailed description of transflectors is included in the '360 application and is incorporated herein by reference.
In one embodiment, the transflective device 1600 is optically coupled to the backlight B, thereby creating a sub-assembly with no air gaps between the transflective device 1600 and the backlight B. Such an embodiment eliminates unwanted loss of light. In an alternative embodiment (not shown), for manufacturing purposes, the transflective device 1600 is positioned adjacent the backlight B such that there is an air gap.
FIG. 17 illustrates an alternative embodiment of a transflective assembly 1700 . In this embodiment, a diffusing layer 1710 is positioned between a transflective device 1720 and a backlight B. In one embodiment, one side the diffusing layer 1710 is optically coupled to the transflective device 1720 and the opposite side of the diffusing layer 1710 is optically coupled to the backlight B, thereby creating an assembly 1700 with no air gaps. In an alternative embodiment (not shown), the diffusing layer 1710 is positioned between the transflective device 1720 and the backlight B such that air gaps exist.
FIGS. 18 and 19 illustrate sub-assemblies that combine both a collimator and a transflective device. FIG. 18 illustrates one embodiment of a sub-assembly 1800 that includes the collimating device 1400 of FIG. 14 , adjacent to a backlight B. The collimating device 1400 is also adjacent to a transflective device 1810 . The transflective device 1810 is one of a light manipulating device 600 , 900 , 1000 , 1100 , 1200 , or 1300 as shown in FIGS. 6 and 9 - 13 . In an alternative embodiment (not shown), the sub-assembly includes a collimating device having a diffusing layer, as illustrated in FIG. 15 .
In the illustrated embodiment, the sub-assembly components are optically coupled such that there are no air gaps. In an alternative embodiment (not shown), for manufacturing purposes, the collimating device 1400 is positioned adjacent the backlight B such that there is an air gap. In another alternative embodiment (not shown), for manufacturing purposes, the transflective device 1810 is positioned adjacent the collimating device 1400 such that there is an air gap. In yet another alternative embodiment (not shown), for manufacturing purposes, the components are positioned such that there is an air gap between each component of the sub-assembly.
FIG. 19 illustrates one embodiment of a sub-assembly 1900 that includes the transflective device 1600 of FIG. 16 , adjacent to a backlight B. The transflective device 1600 is also adjacent to a collimating device 1910 . The collimating device 1910 is one of a light manipulating device 600 , 900 , 1000 , 1100 , 1200 , or 1300 as shown in FIGS. 6 and 9 - 13 . In an alternative embodiment (not shown), the sub-assembly includes a transflective device having a diffusing layer, as illustrated in FIG. 17 .
In the illustrated embodiment, the sub-assembly components are optically coupled such that there are no air gaps. In an alternative embodiment (not shown), for manufacturing purposes, the transflective device 1600 is positioned adjacent the backlight B such that there is an air gap. In another alternative embodiment (not shown), for manufacturing purposes, the collimating device 1910 is positioned adjacent the transflective device 1600 such that there is an air gap. In yet another alternative embodiment (not shown), for manufacturing purposes, the components are positioned such that there is an air gap between each component of the sub-assembly.
While the present application illustrates various embodiments, and while these embodiments have been described in some detail, it is not the intention of the applicant to restrict or in any way limit the scope of the claimed invention to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's claimed invention.
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A method for manufacturing a collimating device is disclosed herein. In one embodiment the method includes a step of constructing a reflective layer. After the reflective layer is constructed, a step of constructing an optical element layer follows, including a step of forming an array of microstructures in the optical element layer. Next, the array of microstructures is abutted against the reflective layer. Heat and pressure are then applied to the optical element layer to puncture the reflective layer and penetrate a predetermined distance through the reflective layer. Sub-assemblies are also defined, wherein optical elements are coupled to prevent light loss.
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FIELD OF THE INVENTION
The present invention relates to a method for manufacturing composite connecting rods. It more particularly but not exclusively relates to a method for manufacturing connecting rods that can be used in the field of aeronautics and aerospace.
The invention also relates to the connecting rods obtained according to the method and to the end-pieces used for manufacturing the connecting rod.
STATE OF THE ART
It is known that a connecting rod is a component either for stiffening or for transmitting movement. The forces transmitted by the connecting rod are mainly tensile, compression and bending forces based on resistance torque at the end of the rod.
In the field of aeronautics, use is made of a high number of connecting rods. Mention may be made of the use of rods in members for flight control, landing gear, door opening, etc. As an illustration, FIGS. 1( a ), 1 ( b ) and 1 ( c ) represent diagrams of a connecting rod with different, nonexhaustive means for securing at the ends parts; these means ensure the securing of the rod to the members to which it must transmit a movement or from which it is to receive a movement, or to ensure the securing thereof.
A connecting rod is a component that must meet several criteria. It must be able to withstand major thermal variations, the rod being subjected to temperatures oscillating between −55 and 120° C. It must also have a mechanical strength/weight ratio that is as high as possible. For this purpose, the connecting rod is of hollow design and the thickness of the walls at the central part of the rod body is thinner than the parts located at the ends where the end-pieces are secured as will be described below (see FIG. 2 ).
In their most frequent design, connecting rods are made of aluminium or stainless steel depending on their application.
Connecting rods in composite material are also commercially available.
They may be of a single-piece type such as shown in FIG. 3 . The method for manufacturing such a connecting rod is described in document FR 2 705 610 A1. The method consists in depositing pre-impregnated fibres on an extractable mandrel with a shape corresponding to the shape of the rod. The assembly obtained is then polymerized with homogeneous pressure being applied over the entire outer surface of the assembly and finally, after the mandrel is extracted, the rod is machined to the required dimensions. This method is relatively costly and requires the presence of a mandrel of complex shape and its withdrawal.
A method for manufacturing rods is also known from document GB 2 008 484 A, in which a fibre-reinforced plastic material surrounds an expendable mandrel and the anchoring part of each end fitting (securing means) so that when the plastic material is polymerized, the connecting rod is obtained in a single piece. The expendable mandrel is a thin-walled metal tube, a tube in expanded material or a tube in plastic-reinforced fibre and with thin wall. In this embodiment, using different materials for the mandrel and the polymerized layer causes heat-expansion differences to appear with use. These will translate in the onset of cracks and lifting at the interface. If the tube is also made of a composite material with organic matrix, the use of different resins for the mandrel and the polymerized layer translates in contamination and ageing problems. In general, discontinuities and porosities are observed through the section of the rod body when different materials are used for its manufacturing.
Connecting rods may also be found with an added metallic end-piece bonded to the body of the composite rod (see FIG. 4 : the rod body and the end-piece are shown with and without shading, respectively). The disadvantage of such assembly is that it weakens the rod body. When a tensile force is exerted on the metallic end-piece of the rod, the adhesive is worked elastically and causes spacing between the metallic end-piece and the composite part (see FIG. 5( a )). When the end-piece is compressed on the rod, the adhesive is still elastically worked and sets up a bearing point between the metallic end-piece and the composite part (see FIG. 5( b )). With fatigue cycles, this phenomenon will generate cracking on the body of the composite rod and substantially reduce the lifetime of the connecting rod (see FIG. 5( c )).
Aims of the Invention
The present invention aims to provide a solution allowing to overcome the drawbacks of the state of the art.
More particularly, the present invention aims to manufacture connecting rods with a fully homogeneous structure, devoid of any porosity and meeting the criteria of mechanical strength and heat resistance.
The present invention has the further aim to manufacture connecting rods with a method close to conventional methods but generating low production costs whilst avoiding the drawbacks of a bonded assembly.
Main Characteristic Elements of the Invention
The present invention relates to a method for manufacturing a connecting rod comprising a rod body in composite material and at least one end-piece, said end-piece comprising a first cylindrical hollow part, a conical hollow part and a second cylindrical hollow part, successively, said second cylindrical hollow part ending in an end part of reduced outer diameter delimited by a shoulder, said method comprising at least the following steps, successively:
a) an inner body is achieved by the following sub-steps:
a tube is achieved by winding pre-impregnated fibres onto a first rotating mandrel, said tube having a wall thickness equal to the height of the shoulder and an outer diameter equal to the maximum outer diameter of the second cylindrical hollow part the tube is polymerized, the first mandrel is withdrawn from the tube, the tube is cut to length and its outer side is roughened, thereby forming the inner body;
b) one end of the inner body is added to the end of reduced outer diameter of each end-piece, said end of the inner body bearing on the shoulder of the end-piece; c) a first portion of a second mandrel is inserted into the first cylindrical hollow part of each end-piece and a driving jaw is placed at the free end of a second portion of the second mandrel; d) said pre-impregnated fibres are wound around the outer surface of an assembly formed by the inner body, the end-piece(s) and the jaw-free second portion(s) of the second mandrel(s), said fibres thereby forming an outer body; e) after the jaw(s) are removed, the inner body and the outer body are polymerized to form a single-piece polymerized body; f) the second mandrel(s) are removed and the polymerized single-piece body is cut to length.
According to particular embodiments of the invention, the method comprises at least one or a suitable combination of the following characteristics:
the pre-impregnated fibres wound at steps a) and d) are identical, i.e. they comprise the same resin and the same fibre, and they are continuous; the inner diameter of the first cylindrical hollow part is substantially constant; the outer diameter of the first cylindrical hollow part is substantially constant and the conical hollow part has a wall thickness which tapers towards the second cylindrical hollow part; the outer diameter of the first cylindrical hollow part, starting from its free end, is first constant, then gradually decreases and finally widens again so that it lies in the continuity of the outer side of the conical hollow part, said conical hollow part having a wall thickness which tapers towards the second cylindrical hollow part; the outer diameter of the first cylindrical hollow part, starting from its free end, is first constant, then gradually decreases and finally widens again so that it lies in the continuity of the outer side of the conical hollow part, said conical hollow part flaring towards the second cylindrical hollow part and having a discontinuity where the inner diameter of the conical hollow part suddenly increases; the end-piece comprises an insert integrating the first cylindrical hollow part and partly the conical hollow part as far as the discontinuity, and comprises a complementary part, also called a layer, integrating the remainder of the conical hollow part and the second cylindrical hollow part; the method comprises a least four additional steps for manufacturing said end-piece, said steps being implemented before conducting step b) of the method for manufacturing a connecting rod and being as follows:
1) the insert is achieved; 2) the insert is mounted on a third mandrel successively comprising a first cylindrical portion whose shape mates with the first cylindrical hollow part of the end-piece, a first conical portion whose shape mates with the conical hollow part of said insert, an abutment whose height is substantially equal to the thickness of the insert wall at the free end of its conical hollow part, and a second conical portion flaring towards a second cylindrical portion, said first cylindrical portion of the third mandrel being inserted in the first cylindrical hollow part of the end-piece and said end of the insert coming to bear upon the abutment; 3) one or more layers of said pre-impregnated fibres are wound around the second cylindrical portion and the second conical portion of the third mandrel and partly around the insert up to the discontinuity; 4) the layer(s) of pre-impregnated fibres are polymerized in an oven in order to form the layer and the third mandrel is then removed;
the shoulder is formed by placing a clamping ring between step 3) and step 4) or, preferably, by machining after polymerization step 4); the insert is metallic; the pre-impregnated fibres are identical to those used to perform steps a) and d) and the layer is polymerized with the inner body and the outer body at step e) in order to form a polymerized single-piece body; the end-piece is metallic, made of high-strength plastic material or of carbon; the fibres are carbon fibres; the inner side of the cylindrical hollow part of the end-piece is provided with securing means for the rod; the securing means comprise tapping; the free end of the conical hollow part of the insert has an outer diameter that is smaller than the inner diameter of the rod body; the first portion of the second mandrel is cylindrical and has a diameter substantially equal to the inner diameter of the first cylindrical hollow part of the end-piece, and the second portion of the second mandrel is cylindrical and has a diameter substantially equal to the outer diameter of the first cylindrical hollow part of the end-piece; the polymerized single-piece body is cut to length at step f) by cutting at the level of the free end of each end-piece; the end-piece comprises lathing grooves on its outer side.
The present invention also relates to a connecting rod comprising a rod body in composite material and at least one end-piece, said end-piece successively comprising a first cylindrical hollow part, a conical hollow part and a second cylindrical hollow part, said second cylindrical hollow part ending in an end portion having a reduced outer diameter delimited by a shoulder, and said rod body comprising a polymerized single-piece body tightly gripping the end-piece or an insert of the end-piece over its entire outer side.
The present invention also relates to an end-piece successively comprising a first cylindrical hollow part, a conical hollow part and a second cylindrical hollow part, the inner diameter of said first cylindrical hollow part being substantially constant and said second cylindrical hollow part ending in an end portion having a reduced outer diameter delimited by a shoulder.
According to particular embodiments of the invention, the end-piece comprises at least one or a suitable combination of the following characteristics:
the outer diameter of the first cylindrical hollow part is substantially constant and the conical hollow part has a wall thickness tapering towards the second cylindrical hollow part; the outer diameter of the first cylindrical hollow part, starting from its free end, is first constant, then gradually decreases and finally widens again so that it lies in the continuity of the outer side of the conical hollow part, said conical hollow part having a wall thickness tapering towards the second cylindrical hollow part; the outer diameter of the first cylindrical hollow part, starting from its free end, is first constant, then gradually decreases and finally widens again so that it is lies in the continuity of the outer side of the conical hollow part, said conical hollow part flaring towards the second cylindrical hollow part and having a discontinuity where the inner diameter of the conical hollow part suddenly increases; it comprises an insert and a complementary part, also called a layer, said insert integrating the first cylindrical hollow part and partly the conical hollow part as far as the discontinuity, and said complementary part integrating the remainder of the conical hollow part and the second cylindrical hollow part.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 , already mentioned, shows the general diagram of metallic connecting rods as in the state of the art, with different securing means for the rod.
FIG. 2 , already mentioned, is a longitudinal section view of a connecting rod as in the state of the art, showing the variation in thickness of the walls.
FIG. 3 , already mentioned, is a longitudinal section view of a connecting rod of the single-piece type as in the state of the art.
FIG. 4 , already mentioned, is a partial, cross-sectional and longitudinal view of a rod body with added and bonded end-pieces as in the state of the art.
FIG. 5 , already mentioned, diagrammatically shows tensile demands ( FIG. 5( a )) and compressive demands ( FIG. 5( b )) exerted on a rod body with added and bonded end-pieces as in the state of the art, and the resulting damage ( FIG. 5( c )).
FIG. 6 is a longitudinal section view of an end-piece as in a first embodiment, used when the connecting rod as in the invention is manufactured.
FIG. 7 is a longitudinal section view of an end-piece as in a second embodiment, used when the connecting rod of the invention is manufactured.
FIG. 8 is a longitudinal section view of an end-piece as in a third embodiment, used when manufacturing the connecting rod of the invention.
FIG. 9 is a partial cross-sectional and longitudinal view of an end-piece as in the invention having lathing grooves.
FIG. 10 is a longitudinal section view of the insert prepared at step 1) when the end-piece as in the third embodiment is manufactured.
FIG. 11 is a longitudinal section view of the mounting of the insert on the mandrel at step 2) when the end-piece as in the third embodiment is manufactured.
FIG. 12 is a longitudinal section view of step 3) for filament winding when the end-piece as in the third embodiment is manufactured.
FIG. 13 is a side view of the formation of the inner body of the connecting rod by filament winding as in the invention (step a)).
FIG. 14 is a longitudinal section view of the inner body of the rod obtained at step a).
FIG. 15 is a longitudinal section view of the assembling of the end-pieces with the inner body of the rod (step b)).
FIG. 16 is a longitudinal section view of the mounting of the mandrels at step c) of rod manufacture.
FIG. 17 is a longitudinal section view of the mounting of the driving jaws at step c) of rod manufacture.
FIG. 18 is a longitudinal section view of the formation of the outer body by filament winding at step d) of rod manufacture.
FIG. 19 shows longitudinal section views of the assembly before a) and after (b) polymerization at step e) of rod manufacture.
FIG. 20 is a longitudinal section view of the finished part (connecting rod) after the mandrels are removed and a cutting operation (step f)), the end-pieces being obtained as in the first embodiment.
FIG. 21 is a longitudinal section view of the finished part (connecting rod) after the mandrels are removed and a cutting operation (step f)), the end-pieces being obtained as in the third embodiment.
FIG. 22 diagrammatically shows the compression demands (a) and tensile demands (b) exerted on the rod obtained as in the invention with end-pieces as in the first embodiment.
FIG. 23 diagrammatically shows the compression demands (a) and tensile demands (b) exerted on the rod obtained as in the invention with end-pieces as in the second embodiment.
KEY
( 1 ) First cylindrical hollow part of the end-piece
( 2 ) Tapping
( 3 ) Conical hollow part of the end-piece
( 4 ) Second cylindrical hollow part of the end-piece
( 5 ) End of the second cylindrical hollow part of the end-piece with reduced outer diameter
( 6 ) Shoulder
( 7 ) Discontinuity in the conical hollow part of the end-piece
( 8 ) Insert of an end-piece
( 9 ) Complementary part, also called layer, of an end-piece
( 10 ) Third mandrel used for manufacturing an end-piece
( 11 ) First cylindrical portion of the mandrel
( 12 ) First conical portion of the mandrel
( 13 ) Abutment of the mandrel
( 14 ) Second conical portion of the mandrel
( 15 ) Second cylindrical portion of the mandrel
( 16 ) Pre-impregnated fibre
( 17 ) First mandrel used for manufacturing the inner body
( 18 ) Inner body
( 19 ) Second mandrel used for manufacturing the outer body
( 19 a ) First portion of the second mandrel ( 19 ) ( 19 b ) Second portion of the second mandrel ( 19 )
( 20 ) Driving jaws
( 21 ) Outer body
( 22 ) Polymerized single-piece body
( 23 ) Lathing grooves
( 24 ) Compression force
( 25 ) Tensile force
( 26 ) Bearing zone
DETAILED DESCRIPTION OF THE INVENTION
The design of the connecting rod as in the invention lies midway between the single-piece rod and the rod with added, bonded metal end-piece.
In the present invention, the connecting rod comprises a composite rod body and at least one end-piece. The rod may comprise an end-piece at each end, or it may comprise an end-piece at only one end and a bearing at the other end, directly inset into the rod. The figures below give non-limiting illustrations of the method for manufacturing the rod for cases when both ends comprise an end-piece.
First, the end-pieces and their manufacturing method will be described. Thereafter, the method for manufacturing the connecting rod formed by the end-piece(s) and by the rod body will be detailed.
Detailed Description of the End-Pieces and their Manufacturing Method
The end-piece as in the invention preferably has three different embodiments. The end-piece may however have any other form useful for implementing the method for manufacture a rod such as described below.
The end-pieces as in the three embodiments, shown in FIGS. 6 to 8 , respectively, have the common feature that they are formed of three main parts. Each end-piece comprises a first cylindrical hollow part 1 followed by a conical hollow part 3 flaring towards a second cylindrical hollow part 4 . By “cylindrical hollow part of the end-piece” is meant that the end-piece comprises a bore of cylindrical shape. The term “inner” is used to designate the side facing the cylindrical bore as opposed to the term “outer” designating the other side.
The first cylindrical hollow part 1 forms the free end of the end-piece after it is assembled with the rod body, and the second cylindrical hollow part 4 is intended to be assembled to the rod body. The first cylindrical hollow part 1 is provided on its inner side with securing means for the rod. In the examples shown in FIGS. 6 to 8 , it is tapped (tapping 2 ) for subsequently receiving a rod-securing element. The securing element may also be an integral part of the end-piece; the end-piece may, for example, be fork-shaped (not shown).
According to the three embodiments of the end-piece, the second cylindrical hollow part 4 ends in an end portion of reduced outer diameter 5 delimited by a shoulder 6 .
FIG. 6 shows the different parts forming the end-piece as in a first embodiment of the invention. According to this embodiment, the first cylindrical hollow part 1 has a wall thickness that is substantially equal along the longitudinal axis of the end-piece, and the conical hollow part 3 has a wall thickness tapering towards the second cylindrical hollow part 4 .
The end-piece as in a second embodiment of the invention, shown in FIG. 7 , has the characteristic that the first cylindrical hollow part 1 varies in wall thickness along the longitudinal axis of the end-piece, whilst always maintaining a bore of cylindrical shape with a substantially constant diameter. Starting from the free end, the outer diameter of the first cylindrical hollow part 1 is first constant, before gradually decreasing and finally widening again so that it lies in the continuity of the outer side of the conical hollow part 3 .
The end-piece as in a third embodiment of the invention, shown in FIG. 8 , comprises a first cylindrical hollow part 1 substantially comparable to that as in the second embodiment of the end-piece and comprises a second cylindrical hollow part 4 substantially comparable to that as in the first and second embodiments. The end-piece as in the third embodiment has the characteristic that the wall of the conical hollow part 3 has a discontinuity 7 . At the level of the discontinuity and in the direction of the increasing cross-section of the conical part, the inner diameter of the conical part suddenly increases. This discontinuity originates from the manufacturing method for the end-piece which is detailed below.
According to this third embodiment, the end-piece comprises an insert 8 integrating the first cylindrical hollow part 1 and partly the conical hollow part 3 as far as the discontinuity 7 , and comprises a complementary part 9 , also called a layer, integrating the remainder of the conical hollow part 3 and the second cylindrical hollow part 9 . According to the invention, the insert 8 and the layer 9 are joined together during the manufacture of the end-piece.
According to the first and second embodiment, the end-pieces are preferably metallic (e.g. aluminium, 17-4 stainless steel or titanium) and are conventionally machined; they have lathing grooves 23 on their outer side produced during rapid-advance lathing (see FIG. 9 ). These grooves 23 will allow the gripping between the end-piece and the reinforcement fibre of the rod. The end-pieces may also be made of a high-strength plastic, of carbon or of any other material suitable for the intended application.
According to the third embodiment of the end-piece, the insert 8 is preferably metallic and the layer 9 is preferably of composite material. This end-piece resorts to an innovative manufacturing method which comprises at least four steps.
At a first step 1), the insert 8 is prepared which may be metallic as mentioned above or made of any material adapted for its use (see FIG. 10 ). The maximum outer diameter of the conical part 3 of the insert is of reduced size compared to the inner diameter of the body of the future connecting rod.
At a second step 2), shown in FIG. 11 , the insert is mounted on a metallic mandrel 10 . The mandrel 10 comprises a first cylindrical portion 11 which is inserted in the first cylindrical hollow part 1 of the insert and comprises a first conical portion 12 whose shape mates with the conical part 3 of the insert, followed by an abutment 13 against which the insert 8 comes to bear. The height of the abutment 13 is substantially equal to the thickness of the wall of the insert 8 at its end part. After the abutment 13 , the mandrel 10 comprises a second conical portion 14 flaring towards a second cylindrical portion 15 whose shape mates with the layer 9 of the end-piece to be formed.
At a third step 3), shown FIG. 12 , one or several layers of pre-impregnated fibres 16 are deposited by filament winding around the second cylindrical portion 15 and the second conical portion 14 of the mandrel, and partly around the insert 8 up to the discontinuity 7 . According to the present invention, the pre-impregnated fibres 16 are identical to those used during the formation of the rod body and are preferably of carbon fibre.
At a fourth step 4), the layer(s) of pre-impregnated fibres 16 are polymerized in an oven in order to form layer 9 ; the mandrel 10 is then removed (not shown).
The shoulder 6 , such as shown in FIG. 8 on the final part, is achieved by placing a clamping ring before polymerization (between step 3) and 4)), or preferably by conventional machining after the polymerization step 4).
The method such as described above applies indifferently for manufacturing the left or right end-piece of a connecting rod.
Similarly to the end-pieces as in the first and second embodiments, the end-piece comprises a lathing groove on its outer side.
Detailed Description of the Method of Manufacturing the Connecting Rod
According to the present invention, the rod is manufactured in six steps. By way of illustration the method for manufacturing the rod is illustrated in FIGS. 13 to 20 with end-pieces as in the first embodiment. The method with end-pieces as in the second and third embodiments is similar.
A first step a) consists in forming an inner body by conventional filament-winding method, in which a pre-impregnated fibre 16 is wound onto a smooth mandrel 17 at a given angle using a to-and-fro movement as shown in FIG. 13 . Preferably, the wound fibres are carbon fibres. However, any other high-strength fibre may also be suitable.
A tube is formed with a thickness that is equal to the height of the above-mentioned shoulder 6 . The inner diameter of the tube is determined by the inner diameter of the body of the rod to be formed and on the basis of dimensioning calculations to determine the maximum compression load that the tube can withstand without deforming at the level of the bearing zone 26 between the endpiece and the tube i.e. at the level of the shoulder.
The tube and mandrel assembly is then placed in an oven to polymerize the resin pre-impregnating the fibres and thereby rigidify the tube. After polymerization, the mandrel 17 is removed and the tube is cut to length and roughened to obtain an adhering surface. The inner body 18 thus obtained is shown in FIG. 14 .
A second step b) consists in adding an end-piece to each end of the inner body. The added end-piece is an end-piece as in the first, second or third embodiment such as shown in FIGS. 6 to 8 , respectively, or any end-piece of adapted shape. The end of the inner body 18 is joined to the end having a reduced outer diameter 5 and bears against the shoulder 6 . In this way, the outer surface of the inner body 18 extends that of the second cylindrical part 4 of the end-pieces (see FIG. 15 ).
At a third step c), two mandrels 19 are mounted at the respective free ends of the end-pieces (see FIG. 16 ). Each mandrel of cylindrical shape comprises two portions of different diameters. A first portion 19 a of the mandrel comprises a cylinder of a diameter that is substantially equal to the inner diameter of the first cylindrical hollow part of the end-pieces 1 , and a second portion 19 b comprises a cylinder of a diameter that is substantially equal to the outer diameter of the first cylindrical hollow part of the end-pieces 1 . During assembly, the first portion 19 a of the mandrel 19 is inserted into the cylindrical hollow part 1 of the end-piece. A driving jaw 20 is then arranged at the free end of the second portion 19 b of the mandrel 19 (see FIG. 17 ).
The fourth step d) shown in FIG. 18 consists in winding pre-impregnated fibres 16 over the outer surface of the assembly formed by the inner body 18 , the end-pieces, and the jaw-free second portion 19 b of the mandrels, by the filament-winding method. The fibres will form a layer around this assembly which will be called the outer body 21 (see FIG. 19 ( a )). In order to subsequently form a single-piece body as described below, the pre-impregnated fibres used at this step are the same (same fibre, same resin) as those used at step a). Similarly, to ensure the continuity of the filament winding, there is no interruption of the fibre between steps a) and d).
The fifth step e) consists in polymerizing the assembly after the driving jaws 20 are removed. FIGS. 19( a ) and 19 ( b ) show the assembly before and after polymerization, respectively. After polymerization, the inner body 18 and the outer body 21 form a polymerized single-piece body 22 which will form the body of the connecting rod. In the particular case of the end-piece as in the third embodiment such as shown in FIG. 8 , the layer 9 formed of pre-impregnated fibres 16 identical to those used to achieve the body of the connecting rod, is also part of the polymerized single-piece body 22 . When the jaws are dismounted at this step, the fibre is cut from the reel and the polymerized single-piece body part comprising the cut fibre is removed when the connecting rod is cut to length at the last step f).
At the last step f), the mandrels 19 are removed and the polymerized single-piece body 22 is cut at the level of the free end of the end-pieces (see FIG. 20 ). The part thus obtained forms the connecting rod as in the invention. FIG. 21 shows the rod formed with the end-pieces as in the third embodiment, in which the layer 9 of the end-piece is integrated into the single-piece body 22 .
Advantages of the Method of the Invention
According to the present invention, the pre-impregnated fibres used at steps a) and d) are identical (same resin, same fibre) and there is continuity between the filament windings (same filament) for the inner body and the outer body. Using one same resin allows to form a single-piece body during post-curing at step e), that will be devoid of any differential heat-expansion problem. The continuity of the filament winding is important to guarantee correct positioning of the fibres and to guarantee a 100% automated process. The manufacture of a single-piece body and the continuity of the filament winding also allows to obtain a product devoid of any discontinuity or porosity.
The manufacture of connecting rods with end-pieces formed as in the third embodiment allows to reduce the weight of the rod. On the one hand because part of the end-piece is in composite material and on the other because there is a smaller amount of material in the end-piece. Indeed, at the level of the discontinuity, the inner diameter of the end-piece increases which in other words corresponds to a removal of material.
Unlike the bonded assembly of the prior art, in which the end-pieces are adjoined to the rod body, the end-pieces of the present invention are inserted inside the rod body. This design of the rod will allow it to take the load of the compression forces 24 . For a connecting rod with endpieces obtained as in the first embodiment, the highlighted zones in FIG. 22( a ) are regions on which demand is placed firstly by a gripping effect between the end-piece and the rod body, and secondly by direct bearing between the rod body in carbon fibre and the endpiece at the level of the shoulder 6 . In the event of too heavy loading, only the bearing zone 26 at the level of the shoulder 6 needs to be fractured in order to move the endpiece. The geometry of the end-piece as in the second embodiment has the advantage that two zones instead of one need to be fractured in the event of overload. As shown in FIG. 23( a ) there is the bearing zone 26 at the level of the shoulder 6 and the zone where the first cylindrical hollow part of the end-piece 1 is narrowing. In concrete terms, this means that the geometry of the end-piece as in the second embodiment allows it to take the load of more forces. The design of the connecting rod as in the invention will also allow it to take the load of tensile forces 25 , irrespective of the geometry of the end-piece. For a connecting rod with end-pieces formed as in the first embodiment such as shown in FIG. 22( b ), the end-piece transmits the tensile force 25 to the rod body via the first cylindrical hollow part 1 , via the conical part 3 and partly via the second cylindrical hollow part 4 . The tensile force 25 is therefore directly transmitted to the body of the rod. For a rod with end-pieces formed as in the second embodiment such as shown in FIG. 23( b ), the end-piece transmits the tensile force 25 to the rod body via the conical part 3 and partly via the second cylindrical hollow part 4 . In the frame of alternate tensile-compression stresses, the end-piece, whatever its geometry, cannot move inside the rod body and therefore cannot generate a fatigue phenomenon on the carbon fibre body and a phenomenon of plastic deformation of the carbon-fibre body.
The method as in the invention also advantageously allows the manufacture of a complex part using conventional filament-winding methods, which generates low production costs. The gain is found in the implementation of the methods and in the design of the connecting rod itself.
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The present invention relates to a method for manufacturing a connecting rod including: a) manufacturing an inner body; b) adding one end of the inner body to the end of the reduced outer diameter of each end piece, said end of the inner body resting on the shoulder of the end piece; (c) inserting a first portion of a second mandrel in the hollow cylindrical portion of each end piece and placing a driving bit at the free end of a second portion of the second mandrel; d) winding said pre-impregnated fibers onto the outer surface of an assembly consisting of the inner body, the end piece(s) and the second part(s) of the second mandrel(s) which are free of bits, said fibers then forming an outer body; e) after removing the bit(s), polymerizing the inner body and the outer body to form a polymerized integral body; f) removing the second mandrel(s) and cutting the polymerized integral body to the required length.
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BACKGROUND OF THE INVENTION
The present invention relates to a workpiece feeding apparatus for a sewing machine used for leather products or the like wherein a workpiece is fed by wheels.
It is a conventional practice in workpiece feeding apparatus for sewing machines to hold a workpiece between wheels disposed at upper and lower positions so as to face each other for the workpiece to be fed out by driving the lower wheel. However, none of those workpiece feeding apparatus has been provided with anything like a workpiece reverse feeding function, in other words, the function of allowing a lower wheel to be rotated in the reverse direction. This is because the one-way clutch which is used to intermittently rotate the lower wheel only has the function of rotating the lower wheel in the forward direction and because it is not adapted to function in the reverse direction.
In a case where the reverse feeding described above is not available, a workpiece has to be turned around when reverse stitching or the like is desired, the user thus being forced to perform troublesome work. To deal with this problem, it is known that a feed dog used in a conventional sewing machine is employed in order to provide both forward and reverse feeding to a workpiece.
However, such a feed dog is designed to perform four motions simultaneously, that is, to and fro motions, and up and down motions, and to feed a workpiece out by engaging the same when it is raised. Therefore, in the case of a leather product workpiece, it is most likely that the surface of the leather product is scratched when it is fed out by the feed dog, which involves the problem that the product value is likely to deteriorate to a great extent.
It is an object of the present invention to provide a workpiece feeding apparatus for feeding a workpiece in forward and reverse directions by means of wheels, thus eliminating any risk of scratching the surface of a workpiece, even if the workpiece is a leather product.
SUMMARY OF THE INVENTION
The present invention is directed to a workpiece feeding apparatus which comprises oscillating members adapted to oscillate through the action of a shaft which rotates with the rotation of a drive shaft, one-way clutches adapted to transform the oscillating motions of the oscillating members into the intermittent rotation of a first feed shaft, and a second feed shaft adapted to rotate in the direction reverse to the rotational direction of the first feed shaft by virtue of rotational motion-transmission mechanisms, whereby rotation of either of these feed shafts is transmitted to a lower wheel by means of a clutch.
In the present invention, both of the shafts are designed to rotate in synchronism with the rotation of the drive shaft, but in the reverse direction relative to each other. As the need arises, a clutch disposed between the shafts is brought into contact with either of the shafts, the rotation of the shaft with which the clutch is in contact thus being transmitted to the lower wheel, which in turn is actuated to feed a workpiece intermittently in synchronism with the vertical motion of a needle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional front view of a sewing machine illustrated herein as one embodiment of the present invention;
FIG. 2 is a bottom view of the same sewing machine;
FIG. 3 is a vertical sectional end view of the same sewing machine as viewed from the left hand side;
FIG. 4 is a vertical sectional end view of the same sewing machine as viewed from the right hand side;
FIG. 5 is an exploded perspective view showing the embodiment of the present invention;
FIG. 6 is a sectional view taken along the line VI--VI of FIG. 5 and showing the forward feeding state;
FIG. 7 is a cross sectional view taken along the line VII--VII of FIG. 6;
FIG. 8 is a sectional view taken along the line VIII--VIII of FIG. 5 and showing the reverse feeding state;
FIG. 9 is an end view as viewed from the right hand side illustrating the first rotational motion-transmission mechanism shown in FIGS. 6 and 8; and
FIG. 10 is an end view as viewed from the left hand side also illustrating the first rotational motion-transmission mechanism.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention will now be described with reference to the accompanying drawings. The same numeral references are assigned to the same components throughout the drawings.
In the figures, reference numeral 1 denotes an intermediate shaft as a drive shaft. Provided at one end thereof is a flywheel 2 connected with a drive source, which is not shown, via a drive belt, and sprockets 3 and 4 are secured on the central portion of the drive shaft 1. The sprocket 3 is connected via a toothed belt 7 with a sprocket 6 which is secured on an arm shaft 5, the sprocket 4 being connected via a toothed belt 10 with a sprocket 9 which is secured on a bottom shaft (shaft body) 8 at one end thereof. With such a construction, the arm shaft 5 and the bottom shaft 8 are designed to rotate as the intermediate shaft 1 rotates, and one rotation of the arm shaft 5 generates one stroke of a needle N (a descending and ascending motion). When descending, the needle N is accepted into a needle hole MAI provided in a work support MA which is provided on the bed of a sewing machine MB in such a manner as to project therefrom.
As shown in FIGS. 2 and 5, an eccentric cam 11 is secured on a certain position of the bottom shaft 8. A feed rod 12 is rotatably fitted over the outer peripheral portion of the eccentric cam 11 at one end thereof and at the other end it is rotatably connected to one end of an arm 14 which is secured at a certain position of an oscillating shaft 13, the oscillating shaft 13 thus being caused to rotate through a predetermined angle in clockwise and counterclockwise directions by the arm 14 which oscillates as the bottom shaft 8 rotates. Provided and secured at one end of the oscillating shaft 13 is an arm 15, which is connected via a link 19a with an arm body 18 as an oscillating member provided at a certain position of a feed shaft 16.
The arm body 18 is mounted on the feed shaft 16 via a one-way clutch 17, which allows the feed shaft 16 to rotate only when the arm body 18 rotates clockwise (refer to FIG. 5).
The feed shaft 16 has, as shown in FIG. 6, a hollow configuration and is supported on a sewing machine main body M via a bearing 21 and a bushing 20, the latter being mounted over the circumference of a one-way clutch 19b.
This one-way clutch 19b is designed to allow rotation in the direction opposite to that allowed by the one-way clutch 17, thus preventing the feed shaft 16 from rotating in the opposite direction while the arm body 18 is being caused to oscillate. Formed on a certain portion of the feed shaft 16 is a gear 16a, which is adapted to engage with an intermediate gear 23 fitted over a shaft 22 which is supported on the sewing machine main body M. Respective gears 27a and 27b are secured at certain positions of a shaft 26 which is rotatably supported by bearings 24 and 25, and the intermediate gear 23 is adapted to engage one of these gears, 27a.
A feed reversing shaft 28 having a hollow configuration is provided along the axis of the feed shaft 16 and supported there on the sewing machine main body M via a bearing 29. Formed at a certain position of the feed reversing shaft 28 is a gear 28a, which is adapted to engage the gear 27b secured on the shaft 26. Thus, the gears 16a, 23, 27a, 27b and 28a together with the shafts 22 and 26 operate as a first rotational motion-transmission mechanism T1.
In addition, the feed shafts 16 and 28 are formed with flared clutch portions 16b and 28b at their opposed ends. A clutch 30 having shaft portions 30c, 30d and clutch portions 30a and 30b corresponding to the clutch portions 28b and 16b, respectively, is provided between the feed shafts 16 and 28 in such a manner that the shaft portions 30c and 30d of the clutch 30 are rotatably supported via bushings 28c and 16c inside the shafts 28 and 16, respectively.
A hole 30e receiving a spring 33 is formed inside the shaft portion 30c of the clutch 30 in such a manner as to extend axially, and splines 30f are formed on the inner surface of the end portion of the hole 30e. Formed in one end of a first gear shaft 32 are splines 32a for engagement with the splines 30f. A presser spring 33 is installed in the hole 30e with one end thereof in contact with the end face of the first gear shaft 32.
Secured at the other end of the first gear shaft 32 is a gear 34 (FIGS. 2 and 5) which engages with a gear 36 secured on a second gear shaft 35. Rotational motion transmitted to the gear 36 is in turn transmitted to a third gear shaft 38 via another gear 37 secured on the second gear shaft 35 and a gear 39 secured at one end of the third gear shaft 38, a bevel gear 38a thus being caused to rotate. This bevel gear 38a is adapted to engage with a gear 41a formed in the side of a lower wheel 41, the lower wheel 41 thus being caused to rotate on an axle 40 according to the rotational direction of the bevel gear 38a. Thus, the gears 34, 36, 37, 38a and 39 and the shafts 32, 35 and 38 operate as a second rotational motion-transmission mechanism T2.
Reference numeral 42 is a reverse lever for use in reverse stiching, which is secured at one end of a shaft 43 supported by the sewing machine main body M. A cam having two projections 44a and 44b is secured on the shaft 43. Two curved links 46 and 47 are connected to the cam 44 in such a manner that they can rotate in forward and reverse directions on a link axle 45. Provided at one end of the respective links 46 and 47 are rollers 48 and 49 which can rotate in both directions. One end of a rod 52 is provided to the other end of the link 46. The other end of the rod 52 is provided to one end of a "dog-leg" shaped link 51 which is supported on the sewing machine main body M via a shaft 50 so as to rotate thereon in both directions. The link 51 is connected to a lever 53 via a rod 54 at the other end thereof.
A shaft 55 having a collar portion 55a is installed in the feed shaft 16, with a return spring 56 and a thrust block 57 fitted thereover, as shown in FIGS. 6 and 8. The thrust block 57 is locked by a nut 58 so that the return spring 56 can be retained therein as it is pressed. Concave portions 30cl and 55al having the same curvature are respectively formed in the end face of the shaft portion 30c of the clutch 30 and the end face of the collar portion 55a of the shaft 55 allowing a spherical body 59 to be fitted therein. The other end of the thrust block 57 is adapted to contact one end of the shaft 53.
Referring again to FIG. 1, reference numeral 60 is an upper wheel mounted at one end of a support arm 61 in such a manner as to be opposite to the lower wheel and to rotate in forward and reverse directions, thus being designed to press the upper surface of the workpiece against the lower wheel.
OPERATION OF THE PREFERRED EMBODIMENT
Operation of the preferred embodiment of the present invention will now be described on the basis of the construction described above.
The forward feeding of a workpiece will first be described.
When feeding a workpiece forward, the reverse lever 42 is located at an upper position, the rollers 48 and 49 of the respective links 46 and 47 thereby being caused to locate at the channel portions 44c and 44d of the cam 44. In this condition, the biassing force produced by the presser spring 33 in the clutch 30 (refer to FIG. 6) overcomes that produced by the return spring 56 in the feed shaft 16, which causes the clutch 30 to move toward the feed shaft 16 side, the clutch portion 30b of the clutch 30 thus being brought into contact with the clutch portion 16b of the feed shaft 16, as shown in FIG. 6. This produces space between the feed reversing shaft 28 and the clutch 30. Under this condition, when the intermediate shaft 1 rotates, the arm shaft 5 and the bottom shaft 8 are caused to rotate in synchronism therewith. Rotation of the bottom shaft 8 causes the eccentric cam 11 to rotate, the feed rod 12 thereby being caused to oscillate to and fro. This oscillating motion is then transmitted to the oscillating shaft 13 via the arm 14 and further to the arm body 18 via the arm 15 and the link 19a, the arm body 18 thus being caused to oscillate through a predetermined angle. This rotation of the arm body 18 causes the one-way clutch 17 to intermittently rotate the feed shaft 16. In other words, the feed shaft 16 is designed to rotate only when the arm body 18 rotates in a certain direction. When the feed shaft 16 rotates, the clutch 30 also rotates due to the fact that they are in contact with each other. Then, the rotational motion of the clutch 30 is transmitted to the first gear shaft 32, the rotational motion of the first gear shaft 32 in turn being transmitted to the second gear shaft 35 via the gears 34 and 36 and further to the third gear shaft 38 via gears 37 and 39. Thus, the rotational motion transmitted to the third gear shaft 38 causes the bevel gear 38a to rotate, which in turn causes the lower wheel 41 to rotate forward (in the direction of the arrow C shown in a solid line in FIG. 5), thus feeding forward the workpiece on the work support MA. As is clear from the above, the lower wheel rotates as the bottom shaft 8 rotates, and as a result, it rotates in synchronism with an ascending and descending motion of the needle N.
As shown in FIGS. 9 and 10, rotational motion of the feed shaft 16 is transmitted from the intermediate gear 23 to the feed reversing shaft 28 via the gears 27a, 27b and 28a. However, since the feed reversing shaft 28 is away from the clutch 30, the rotational motion transmitted to the shaft 28 has no effect on the clutch 30.
Next the reverse feeding of a workpiece will be described hereinbelow.
When effectuating the reverse feeding, the reverse lever 42 is pressed down, whereby the cam 44 is caused to rotate via the shaft 43, which in turn causes the roller 48 to mount on the projection 44a. This causes the link 46 to rotate on the link axle 45, the rod 52 thus being pulled up. This rotates the link 51 connected to the shaft 52, the rotation of the link 51 then causing the lever 53 to rotate via the rod 54, whereby the thrust block 57 is forced into the inside of the feed shaft 16 against the action of the elastic force of the return spring 56, as shown in FIG. 8. In this condition, the biassing force produced by the return spring 56 and acting on the collar portion 55a overcomes the biassing force of the clutch 30 produced by the presser spring 33, whereupon the clutch 30 starts to separate from the feed shaft 16 and is biassed toward the feed reversing shaft 28 via the spherical body 59. This causes the clutch portion 28b of the feed reversing shaft 28 to come into contact with the clutch portion 30a of the clutch 30. Under this condition, when the intermediate shaft 1 rotates, the feed shaft 16 is intermittently rotated by the one-way clutch 17, as previously described. When the feed shaft 16 rotates, the shaft 26 rotates in the same rotational direction as that of the feed shaft 16 via the intermediate gear 23 and the gear 27a. As shown in FIG. 10, rotational motion of the shaft 26 is transmitted to the feed reversing shaft 28 via the gears 27b and 28a, the feed reversing shaft 28 being caused to rotate in the direction reverse to the rotational direction of the feed shaft 16, whereby the clutch 30 and the first gear shaft 32 which are both in contact with the feed reversing shaft 28 are also caused to rotate in the direction reverse to the rotational direction of the feed shaft 16. As previously described, this rotational motion of the first gear shaft 32 is transmitted to the third gear shaft 38 via the gears 34 and 36, the second gear 35 and the gears 37 and 39, the bevel gear 38a thus being caused to rotate. However, since the rotation of the bevel gear 38a in this condition is reverse to the rotation thereof at the time of the forward feeding, the lower wheel 41 is caused to rotate in the reverse feeding direction (in the direction of the arrow R shown by a chain line in FIG. 5), whereby a workpiece is fed in the reverse direction. It is needless to say that the lower wheel 41 rotates intermittently in synchronism with an ascending and descending motion of the needle N, as is the case with forward feeding.
In this embodiment, the lower wheel 41 and the upper wheel 60 (FIGS. 1 and 3) are respectively designed to serve as a drive wheel and a non-drive wheel, the latter for pressing down the upper surface of a workpiece. However, it is also possible to provide the upper wheel 60 with a drive mechanism like one provided for the lower wheel 41, and, in contrast to the above embodiment, even if the upper wheel 60 is made to act as a drive wheel with the lower wheel 41 acting as a non-drive wheel, the same operational effect as that of the above embodiment would be attainable. Furthermore, if both wheels are designed to act as a drive wheel, a more desirable feeding operation will be attained.
Although the conical friction clutch is employed to contact and separating from the first and second feed shafts in the above embodiment, a claw clutch may instead be employed to perform the above described function wherein gears are utilized to contact and separate from the shafts.
As is described above, with this invention, a workpiece can be intermittently fed in forward and reverse directions, and with such a feeding operation even if the workpiece takes the form of a leather product, any risk of scratches can be eliminated. Thus, an advantage of the present invention is that desirable feeding of a workpiece can be attained.
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A sewing machine with a pair of feed wheels which clamp a workpiece therebetween to transport the workpiece, the sewing machine comprising first and second feed shafts each of which have a clutch portion at an end thereof in opposition to each other and a group of gears disposed between these feed shafts for rotating the second shaft in the direction reverse to the rotational direction of the first shaft. The direction of transportation of the workpiece is changed by means of a clutch having a portion which selectively contacts the clutch portion of either the first or second feed wheel.
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[0001] This application claims the benefit of provisional application Ser. No. 60/245,463 filed on Nov. 3, 2000, and provisional application Ser. No. 60/308,552 filed on Jul. 27, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention.
[0003] The present invention relates to surveillance camera systems, and more particularly to a rotary scanner for a surveillance camera for outdoor use that has water-resistant features to prevent rainwater and other moisture from entering the internal mechanics of the scanner, and which includes one or more magnetically operable positioning stops for setting the limits of the camera scan.
[0004] 2. Description of the Prior Art.
[0005] In the field of surveillance cameras, it is often desirable for the camera to be deployed with a housing that is mounted outdoors where it is exposed to changes in climate. It is also desirable for the camera housing to be mounted on a base that is part of an oscillating mechanical rotary unit that allows the camera to scan a particular area. Such rotary scanning units are typically mounted on top of a structure such as a protruding beam or a pole, but are also frequently mounted in an inverted position such as underneath a beam, as a dangling pendant, on a ceiling, and the like. When mounted on top of a structure, the camera housing tends to act as a shield, deflecting precipitation such as rain and snow away from the base. However, when mounted in an inverted position (such as underneath a ceiling or soffit), the underside of the housing and mounting base may be directly exposed to these elements. Over time, such exposure can result in rust and damage to mechanical parts, and, if the housing is penetrated, potential corrosion and damage to the camera and sensitive internal printed circuit boards.
[0006] It is therefore desirable to provide a housing and base assembly for a surveillance camera that is resistant to water and moisture penetration, especially when mounted in an inverted position, to provide protection for the internal electrical and mechanical components from exposure to precipitation, moisture and other external foreign contaminants.
[0007] Oscillating mechanical rotary bases are well known in the art, and have been used on surveillance cameras, household fans, and other devices for many years, allowing such devices to oscillate back and forth between defined limits. Such bases allow a surveillance camera to scan an area between the limits, instead of having a stationary view from being constantly pointed in the same direction. It is often desirable to be able to easily adjust the positions of the end limits or stops of the oscillation area in order to increase or decrease the size of the area to be scanned.
[0008] Existing scanning bases for surveillance cameras utilize one or physical switches inside the camera housing on the rotating part that are associated with adjustable mechanical stops on the stationary base which set the limits of the scan. The mechanical toggle lever of each switch extends out and away from the camera enclosure through a hole in the enclosure. When the rotating part approaches one of the stops, the toggle lever of the switch makes contact with the stop. As rotation continues, the lever is moved, toggling the switch. Circuitry inside the enclosure recognizes the toggle, and reverses the direction of the drive motor thereby reversing the direction of rotation. This rotation continues until the toggle lever encounters another stop, at which point the stop again physically moves the lever, toggling the switch and reversing the direction of rotation. This back and forth rotation continues between the stops. The positions of the stops establish the beginning and ending points of the scanning arc (i.e. the length of the arc of rotation).
[0009] Unfortunately, the opening(s) in the camera enclosure required by the mechanical toggle lever of the switch(es) expose the internal circuitry to the outside atmosphere, and particularly to foreign material such as moisture and dust. Over time, exposure to such foreign material can and often does result in corrosion of the sensitive printed circuit boards, as well as rust and damage to other internal electrical and/or mechanical parts. In addition, over time, the switch lever(s) and contacts tend to wear out as a result of the constant back and forth physical contact of the switch lever(s) and the stop(s). These kinds of continuing failures result in the need to regularly repair or replace significant parts of the rotatable base and/or camera electronics.
[0010] U.S. Pat. No. 4,543,609 discloses a television surveillance camera system that employs a magnet attached to the camera and a set of magnetically sensitive position sensors deployed in fixed positions below the rotational arc of the camera for monitoring and changing the direction of rotation of the camera. However, the position sensors of this invention are fixed, making it impossible to alter the length(s) of the arc(s) of rotation of the camera, or for the camera to rotate through a full 360° or more.
[0011] It is therefore desirable to provide a rotary base for a surveillance camera that provides a flexible and adjustable scanning range through a full 360° or more, while also providing protection for the internal electrical and mechanical components from exposure to outside foreign contaminants.
SUMMARY OF THE INVENTION
[0012] The present invention provides a protective rotatable enclosure for the sensitive internal electrical and mechanical components of a surveillance camera scanner system particularly when deployed in an inverted position together with the ability to set and adjust the limits of the scanning arc(s) of the enclosure (and hence, the surveillance camera mounted thereon) using a series of features including a sloped mounting base with an optional annular lip, a stepped relationship between the mounting base and the rotary spindle, at least one O-ring seal, and the use of one or more fixed-position magnetically responsive electronic sensors located inside the enclosure which are triggered by one or more external magnetic actuators adjustably deployed on the rotatable enclosure.
[0013] The present invention prevents foreign material from entering at the interface between the fixed spindle and the rotatable housing of the camera mounting assembly. The horizontal annular edge of the rotatable housing base of the present invention is sloped toward the outside in order that, when inverted, water, fluids, dust, debris and foreign matter will tend to roll off the housing base instead of seeping inside. An optional vertically oriented annular lip may be provided near the inside edge of the sloped region to further prevent such materials from reaching the inside. Additionally, at least one annular O-ring is provided between the fixed spindle and the rotatable housing base in order to seal the interface between these two parts, further preventing outside contaminants from entering the interior where they could cause premature wear and potential mechanical failures. The O-ring seal is oriented such that it is not in direct communication with the gap between the base and spindle such that it does not make direct contact with fluids from the outside, preventing the seal from being broken or dislodged. The combination of the slope, lip and seal of the present invention is capable of withstanding a sustained force of 65 gallons per minute without allowing penetration to the inside.
[0014] The present invention also allows considerable adjustability and flexibility with respect to establishing and changing the scanning arc(s) through which the enclosure rotates, while keeping the sensitive internal components shielded from outside contaminants. One or more magnetically sensitive contacts as well as other sensitive components are provided at fixed locations inside the enclosure that rotates around them. This provides the dual function of protecting these sensitive electronic components from the outside, while at the same time allowing the enclosure's arc(s) of rotation to be adjusted from the outside. Establishing and changing the limits of the arc(s) of rotation is accomplished using one or more durable magnetic actuators that are adjustably deployed on an external annular plate that is part of the base of the rotatable enclosure. These actuators may be moved to different locations on an annular track provided on the plate. As rotation occurs, each magnetic actuators is brought into conductive proximity of each magnetically responsive sensor inside the enclosure once per rotation. Each time this occurs, a signal is sent by the affected sensor to an internal microprocessor. The microprocessor can be programmed to selectively respond to the signals it receives from the sensors to change the direction of rotation, or to selectively ignore the signals to allow rotation to continue.
[0015] By programming different responses or patterns of responses to these signals, a wide range of rotational possibilities are available. Different modes of programming may also be implemented to change the pattern(s) of rotational arc(s). The rotational arc(s) may also be affected by changing the physical location of the actuators on the track. Thus, through a combination of physical and programming adjustments, virtually any desired rotational pattern may be established. Since magnetically responsive sensors are used, there is no physical contact between the actuators and the sensors, allowing the sensors to be physically separated from the actuators and enclosed inside the rotatable housing.
[0016] The speed of rotation may also be selected manually using a speed selection switch. Typical speeds for the stepper motors used in surveillance camera systems of this type range from 3 to 12 degrees of rotation per second. The present invention has a 3 position manual switch capable of selecting either 3°, 6° or 12°.
[0017] It is therefore a primary object of the present invention to prevent premature wear and potential mechanical failures by providing a rotatable protective surveillance camera support housing for covering sensitive electronic scanning equipment that is attached to a stationary base that prevents outside contaminants from reaching the inside, particularly when mounted in an inverted position.
[0018] It is also a primary object of the present invention to provide a method and apparatus for easily adjusting the rotational scanning arc(s) of a rotatable surveillance camera support housing while protecting the sensitive electronic scanning equipment inside the housing from outside contaminants.
[0019] It is also an important object of the present invention to provide a protective enclosure for holding sensitive electronic surveillance camera scanning equipment having an annular edge that is sloped toward the outside in order that, when inverted, water, fluids, dust, debris and other foreign matter will tend to roll off the enclosure instead of seeping inside.
[0020] It is also an important object of the present invention to provide a protective enclosure for holding sensitive electronic surveillance camera scanning equipment having a vertically oriented annular lip provided near the inside edge of the sloped region to further prevent outside contaminants from reaching the inside.
[0021] It is also an important object of the present invention to provide a protective enclosure for holding sensitive electronic surveillance camera scanning equipment having one or more annular O-rings provided between a fixed spindle and the rotatable enclosure in order to seal the interface between these two parts, further preventing outside contaminants from entering the interior where they could cause premature wear and potential mechanical failures.
[0022] It is also an important object of the present invention to provide a method and apparatus for easily adjusting the rotational scanning arc(s) of a rotatable surveillance camera support housing using one or more magnetically sensitive contacts deployed inside the housing instead of on the outside, serving the dual function of protecting sensitive interior electronic components from the outside, while at the same time allowing the housing's arc(s) of rotation to be adjusted from the outside.
[0023] It is also an important object of the present invention to provide a method and apparatus for easily adjusting the rotational scanning arc(s) and limits of a rotatable surveillance camera support housing by using one or more durable magnetic actuators that are adjustably deployed on an external annular plate that is part of the rotatable camera support housing base, such that the internal magnetically sensitive contacts are activated through the wall of the housing by the magnetic actuators as they rotate into the conductive proximity of the sensors.
[0024] It is also an important object of the present invention to provide a method and apparatus for easily adjusting the rotational scanning arc(s) of a rotatable surveillance camera support housing having one or more internal magnetically sensitive contacts and one or more adjustable external magnetic actuators and an internal microprocessor that may be programmed to selectively respond to the signals it receives from the contacts to either change the direction of rotation, or to selectively ignore the signals to allow rotation to continue.
[0025] It is also an important object of the present invention to provide a method and apparatus for easily adjusting the rotational scanning arc(s) of a rotatable surveillance camera support housing using a programmable microprocessor that selectively responds to signals from internal magnetically sensitive contacts as they are activated by external magnetic actuators in conjunction with physically adjusting the position(s) of the actuator(s) on an external track.
[0026] It is also an important object of the present invention to provide a method and apparatus for manually adjusting the speed of rotation of a rotatable surveillance camera support housing.
[0027] Additional objects of the invention will be apparent from the detailed descriptions and the claims herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] [0028]FIG. 1 is a perspective exterior view of one embodiment of the present invention.
[0029] [0029]FIG. 2 is a side elevational view of the embodiment of FIG. 1
[0030] [0030]FIG. 3 is an inverted sectional side view of the embodiment of FIGS. 1 and 2.
[0031] [0031]FIG. 4 is a detailed sectional side view of a portion of FIG. 3.
[0032] [0032]FIG. 5 is a detailed sectional side view of a different portion of FIG. 3.
[0033] [0033]FIG. 5A is an alternative embodiment of the invention of FIG. 5.
[0034] [0034]FIG. 6 is a partially cut-away side elevational view of the internal scanning mechanism of the present invention without the outer housing.
[0035] [0035]FIG. 7 is a top view of FIG. 6.
[0036] [0036]FIG. 8 is a perspective view of FIG. 6.
[0037] [0037]FIG. 9 is a bottom view of the support base showing magnetic positioning stops.
[0038] [0038]FIG. 10 is a sectional view along line 10 - 10 of FIG. 2.
[0039] [0039]FIG. 11 is a bottom view of a magnetic positioning stop.
[0040] [0040]FIG. 12 is a sectional view along line ( 12 - 12 ) of FIG. 11.
[0041] [0041]FIG. 13 is a perspective view of a magnetic positioning stop.
[0042] [0042]FIG. 14 is a schematic of the circuitry for the scanner of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] Referring to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, and referring particularly to FIGS. 2 and 6, it is seen that the rotary scanner of the present invention includes a stationary section and a rotatable section. The stationary section includes a base 11 for attachment to a flat surface such as a wall, ceiling, soffit or shelf; a spindle 12 fixedly attached to mounting plate 11 ; and a set of electronic components fixedly attached to spindle 12 . The proximal end of spindle 12 is attached to base 11 and the distal end supports the internal components. The rotatable section includes a support base 18 that fits over spindle 12 , and a housing 17 that is fixedly attached to base 18 . Rotatable housing 17 covers the motor, gears, microprocessor, magnetically responsive sensors, and other mechanical and electronic parts that allow the rotatable section to rotate relative to the stationary section. A camera is mounted on table 13 on the exterior of housing 17 .
[0044] The path of rotation is shown by arrows 9 in FIG. 7. The gears, mechanics, wiring and contacts between the stationary section and rotatable section allow the rotatable section to rotate continuously in either direction, clockwise or counterclockwise. Thus, if no stops are provided, it is capable of rotating around and around in either direction indefinitely.
[0045] Referring to FIGS. 3 and 5, a plurality of steps 19 are provided on spindle 12 which correspond to steps 21 on rotatable base 18 (see detail FIG. 5). At least one bearing 23 is provided between spindle 12 and base 18 . At least one deformable annular seal 20 is provided in the gap between the steps 19 of spindle 12 and the corresponding steps 21 on base 18 . The body of seal 20 fits into one of the steps 19 of spindle 12 , and includes a deformable annular flange 22 which extends out to seal against a corresponding step 21 on base 18 . The seal prevents water, moisture, dust and other contaminants from reaching bearings 23 or from penetrating further and potentially reaching the internal components inside housing 17 , particularly when inverted as shown in FIG. 3.
[0046] As an additional water-resisting feature, the outer bottom surface 25 of base 18 is radially sloped away from the center such that any precipitation that falls upon this surface is directed by gravity to the outside and away from the central workings of the scanner. As a further water-resisting feature, an overlapping annular flange 24 is provided at the intersection of base 18 and housing 17 , as shown in FIGS. 3 and 4. The radial slope of annular surface 25 combined with the overlapping annular flange 24 help direct precipitation out and away from the center of the scanner.
[0047] In an alternative embodiment shown in FIG. 5A, an additional annular ridge or lip 26 is provided at the center of the radially sloping surface 25 of base 18 in the area immediately adjacent to spindle 12 . Lip 26 acts as a barrier preventing precipitation falling onto surface 25 from entering the internal central area of the scanner. The lip 26 is useful in deployments where wind or other environmental conditions might overcome the gravitational slope of surface 25 and blow precipitation, dust and other contaminants into the central area of the scanner.
[0048] Referring to FIGS. 6 - 12 , it is seen that one or more limit devices or stops 31 are provided for adjustable attachment to annular plate 15 of base 18 . Each stop 31 includes a detachable attachment device, clamp or thumbscrew 32 for fixing the position of the stop 31 on an annular track on plate 15 , preferably using an annular groove 30 . Stop 31 is magnetized. Alternatively, at least the upper portion 25 of stop 31 is magnetized. This may be done, as illustrated in FIG. 12, using a magnet 35 that is held in place using a screw 36 or other attachment device. A captive screw 39 is also provided on stop 31 alongside thumbscrew 32 for engagement with groove 30 on plate 15 . Captive screw 39 may be used in conjunction with or as an alternative to thumbscrew 32 for setting the position of stop 31 . Captive screw 39 may be partially threaded into groove 30 allowing stop 31 to slide in the groove, but preventing stop 31 from falling off or being removed from groove 30 . Thumbscrew 32 is then used to fix the position of stop 31 . Alternatively, thumbscrew 32 may be eliminated and the position of stop 31 fixed by fully threading captive screw 39 into groove 30 . This makes it more difficult to change the position of stop 31 , discouraging unauthorized users from making such position changes.
[0049] The stationary mechanical and electronic components inside housing 17 include a reversible motor 51 (preferably a stepper motor) to impart rotational motion to base 18 relative to spindle 12 . A micro-controller or processing unit 33 is also provided inside housing 17 for controlling such things as the speed and direction of motor 51 , among other things. One or more magnetically responsive sensors 29 are also provided inside housing 17 in communication with microprocessor 33 . The motor 51 , microprocessor 33 , and sensors 29 are all attached to spindle 12 such that their positions do not change as base 18 and housing 17 rotate around them.
[0050] The operation of motor 51 causes base 18 to rotate relative to stationary spindle 12 . The magnetically sensitive contacts 29 are provided inside housing 17 near its perimeter. Each sensor or contact 29 is positioned such that as motor 51 rotates base 18 , each actuator or stop 31 attached to plate 15 travels on a circular path or track that passes directly under each sensor 29 . This path is shown by the circular phantom line 46 of FIG. 7. Each contact 29 is mounted such that its magnetically sensitive region comes into conductive relationship with the magnetic portion 35 of each stop 31 once along circular path 46 . When such a conductive relationship is reached, sensor 29 sends a signal to the processing unit 33 . Upon receipt of the signal, processing unit 33 may reverse the direction of rotation of motor 51 , reversing the direction of movement of base 18 . This reversal in direction will eventually bring contact 29 again into conductive relationship with stop 31 whereupon a signal is again sent to processing unit 33 which may again result in the reversal of direction of motor 51 and base 18 .
[0051] The magnetically triggered limits of the present invention allow for complete encapsulation of the sensitive circuitry and mechanics of the rotatable mount, while maintaining all of the flexibility of adjustment of existing mounts. The encapsulation of the sensitive internal components of the mount protects them against failure from exposure to corrosive moisture and other external elements, prolonging the useful life of these components.
[0052] In a simple embodiment, a single contact 29 and a single stop 31 is provided, and the processor 33 is programmed to interpret every signal from contact 29 (each time it encounters stop 31 ) as “change direction.” As a result, in this embodiment rotatable base 18 will travel back and forth through a full 360° circle, reversing direction each time. If a second stop 31 is provided in this embodiment, then base 18 will rotate back and forth on an arcuate path of less than 360° between the two stops 31 . Thus, if the stops are 50° apart, base 18 will travel on an arc of either 50° or 310° between the two stops, depending upon where contact 29 was at the beginning of movement.
[0053] In another embodiment, two contacts 29 a and 29 b may be provided with a single stop or actuator 31 . Depending upon the programming of the processing unit 33 , the signal from each of such contacts 29 a or 29 b may result in a reversal of direction of motor 51 and base 18 . In this embodiment, if every signal from contact 29 a or 29 b is interpreted to mean “change direction,” and the contacts are 20° apart, and then base 18 will rotate back and forth through a 340° arc. Alternatively, if the first signal from either contact 29 a or 29 b is interpreted as “get ready” and the second signal is interpreted as “change direction,” and the contacts are 20° apart, then base 18 will rotate back and forth through a 380° arc. However, the positions of the contacts 29 a and 29 b inside housing 17 are generally fixed. Thus, in order to adjust the arc of rotation, at least one additional stop or actuator 31 is required.
[0054] In the preferred embodiment, two magnetically sensitive contacts 29 a and 29 b are provided with at least two actuators or stops 31 a and 31 b as illustrated in FIG. 7. The presence of two contacts 29 a and 29 b makes it possible to rotate base 18 through an arc of more or less than 360° depending upon the programming of unit 33 as described in the previous embodiment. The presence of an additional stop 31 b provides additional flexibility with respect to the size of the arc(s) of rotation through which base 18 travels. Depending upon the programming, and the variable positioning of stops 31 a and 31 b with respect to each other, this may be any of several different arcs of more or less than 360°. In particular, the processor may be programmed to ignore certain signals (every other signal, two out of every three signals, etc.) and change direction on other signals. Different processor modes may also be provided, thereby changing the processor's response to signals after a given period of time or a given number of signals/rotations (e.g. once every hour, ignore all signals and rotate through a full 360°; or, continuously changing the pattern of responses to signals (thereby changing the arcs of rotation) at given time intervals (or after a certain number of signals) to change the scope of the scan).
[0055] For example, in the preferred embodiment having two contacts 29 a and 29 b and two actuators or stops 31 a and 31 b, the processor 33 may be programmed to interpret the first signal from contact 29 a as “get ready” and the second signal form contact 29 a as “change direction.” Similarly, when traveling in the opposite direction, the processor 33 may interpret the first signal from contact 29 b as “get ready” and the second signal as “change direction.” Using FIG. 7, if angle A between contacts 29 a and 29 b is 20°, and angle B between stops 31 a and 31 b is 60°, when traveling clockwise stop 31 b will first encounter contact 29 a resulting in a “get ready” signal. When stop 31 a encounters contact 29 a (assuming contact 29 b ignores stop 31 b as it passes by), the above programming will result in a reversal of direction to counterclockwise. After 340° (assuming stop 31 b is again ignored as it passes by contacts 29 b and 29 a ), stop 31 a will be encountered by contact 29 b which is the “get ready” signal. Then, after another 60° (assuming contact 29 a ignores stop 31 a as it passes by), stop 31 b will be encountered by contact 29 b resulting in a reversal of direction. Thus, an overlapping 400° of rotation will occur.
[0056] It will be appreciated from the above example that the microprocessor 33 may be selectively programmed to ignore or not to ignore signals from contacts 29 a and 29 b as stops 31 a and 31 b are encountered (e.g. respond differently to signals or patterns of signals from contacts 29 a and 29 b ), such that different arcs or patterns of arcs may be established for scanning. It will also be appreciated that the lengths of these arcs may be changed by physically changing the position of stops 31 a and 31 b on the track of plate 15 in conjunction with or separate from any change in programming. Employment of additional stops ( 31 c, 31 d, etc.) will allow additional flexibility of programming, arc patterns and arc lengths. The programming mode may also be automatically changed on a periodic or random basis to respond differently to the signals, thereby defining different arcs or patterns of arcs at different times. By using techniques such as these, any desired limit of more or less than 360°, can be achieved at any desired time.
[0057] It is to be appreciated that a plurality of additional stops 31 and/or additional contacts 29 may be provided to allow for any desired combination of arcs of rotation and direction.
[0058] By properly positioning, programming and combining the stops 31 and contacts 29 of the present invention, a wide range of scanning options are available.
[0059] It is to be understood that variations and modifications of the present invention may be made without departing from the scope thereof. It is also to be understood that the present invention is not to be limited by the specific embodiments disclosed herein, but only in accordance with the appended claims when read in light of the foregoing specification.
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The present invention is a protective rotatable enclosure for the sensitive internal electrical and mechanical components of a surveillance camera scanner system that is particularly suited for deployment in an inverted position. The invention includes a sloped mounting base with an optional annular lip, a stepped relationship between the mounting base and the rotary spindle, and at least one O-ring seal. The invention also has the ability to set and adjust the limits of the scanning arc(s) of the scanner enclosure through the use of one or more fixed-position magnetically operable electronic sensors located inside the enclosure which are triggered by one or more external magnetic actuators adjustably deployed on the rotatable enclosure.
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BACKGROUND OF THE INVENTION
This invention relates to an exhaust gas cleaning system for a so-called V-type internal combustion engine having two cylinders arranged in V-shape.
More particularly, the present invention relates to an exhaust gas cleaning system in which secondary air is introduced into an exhaust system of the engine to burn unburnt detrimental components in the exhaust gas.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an exhaust gas cleaning system for a V-type internal combustion engine of the character described, which is simple in structure and can be compactly fitted on the engine in a dead space defined between the V-arranged two cylinders without hindering the layout and maintenance of other devices; and which is easy to maintain and is protected from contact with other members; and which does not degrade the overall appearance of the engine when fitted thereto.
It is another object of the present invention to provide an exhaust gas cleaning system for an internal combustion engine of the character described, which can be effectively cooled to insure the proper cleaning operation over an extended period of time and can greatly prolong its service life.
It is still another object of the present invention to provide an exhaust gas cleaning system for an internal combustion engine of the character described, which is improved in assemblability and requires a reduced number of components so as to simplify the construction.
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a motorcycle having an internal combustion engine equipped with an exhaust gas cleaning system in accordance with the present invention;
FIG. 2 is a plan view, partly broken away and in section, showing a secondary air supplying system of the engine;
FIG. 3 is a sectional view taken along line III--III in FIG. 2;
FIG. 4 is a sectional view taken along line IV--IV in FIG. 2;
FIG. 5 is a sectional view taken along line V--V in FIG. 4; and
FIG. 6 is a sectional view taken along line VI--VI in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, a preferrerd embodiment of the present invention will be described in detail with reference to the accompanying drawings. In FIGS. 1 and 3, a V-type internal combustion engine E having two cylinders 1, 1 transversely arranged in a V-shape is mounted on the frame F of a motorcycle V. An intake port 5 is formed in the rear half of a cylinder head 2 of each cylinder 1 so as to communicate with a combustion chamber 4 defined in each cylinder bore above a piston 3 while an exhaust port 6 is defined in the front half of the cylinder head 2 so as to communicate with the combustion chamber 4. Each intake port 5 opens at the rear surface of the cylinder 1 and each exhaust port 6 opens at the front surface thereof. An intake pipe 12 leading to a carburetor 7 is connected to the intake port 5 and an air cleaner 8 is connected to the rear end portion of the intake pipe 12. As shown in FIG. 5, the exhaust port 6 is bifurcated from the externally open end portion towards the combustion chamber 4 and communicates at the respective bifurcated ends with exhaust valve openings 15, 15 that open to the combustion chamber 4. An exhaust pipe 13 is connected to the external open end of the exhaust port 6 and a muffler 10 is connected to the rear end of the exhaust pipe 13. A catalytic converter 11 for reaction and cleaning of the exhaust gas is disposed in the muffler 10. Two intake valve openings 14, 14 are formed to open to the combustion chamber 4 in opposing relation to the exhaust valve openings 15, 15 respectively.
As is customary in the art, the cylinder head 2 is equipped with intake and exhaust valves 16, 16; 17, 17 for opening and closing the intake and exhaust valve openings 14, 14; 15, 15 of the intake and exhaust ports 5; 6. Those valves are actuated by cooperation of valve springs 18, 18 and valve operating mechanisms 19, 19. A spark plug P is screwed into the cylinder head 2 at a position between the intake and exhaust valves 16, 16; 17, 17 with its electrode being present in the combustion chamber 4. A cylinder head cover 20 is mounted on the cylinder head 2.
A secondary air supplying system A is connected between the body of the internal combustion engine and the air cleaner 8 in order to feed secondary air to the exhaust ports 6. This secondary air supplying system A will be described below. As shown in FIG. 2, a secondary air intake pipe 21 is connected at one end with the air cleaner 8 and at the other end with an inlet 23 of a known air control valve 22 which is operated to open in response to the starting of the engine E. The air control valve 22 has an outlet 24 connected to a main secondary air supplying pipe 25 which is, in turn, connected to an inlet 26 of a secondary air reservoir chamber Ch having a relatively large capacity.
As shown in FIG. 3, the secondary air reservoir chamber Ch is fixedly mounted by a mounting bolt 38 onto a support member 37 which bridges between the V-arranged right and left cylinders 1, 1 and is secured thereto by fixing bolts 42, 42 in a substantially horizontal manner. The mounting position of the chamber Ch can be adjusted in the transverse direction by making the fitting holes for the fixing bolts 42, 42 greater in diameter than the bolt 42. Vertical adjustment of the chamber Ch can be made by interposing a spacer between the cylinders 1 and the support plate 37. A V-shaped space is defined between the right and left cylinders 1, 1 and the secondary air reservoir chamber Ch. Reed valve devices L, L, which will be described later in further detail, are disposed on the right and left sides of the secondary air reservoir chamber Ch, and secondary air supplying pipes 28, 28 are connected with outlets 27, 27 of the reed valve devices L, L, respectively. As shown in FIG. 2, these pipes 28, 28 are wound to surround the outer surfaces of the cylinders 1, 1 and extend toward fitting flanges 39 welded thereto. As clearly shown in FIG. 5, each fitting flange 39 is fixed by a fitting bolt 40 to the cylinder head 2 via a gasket 41, and the secondary air supplying pipes 28, 28 communicate with the exhaust ports 6, 6, respectively, via secondary air distribution passages 29, 29 formed at the front portion of the cylinder head 2.
The secondary air supplying pipes 28, 28 have substantially the same length and diameter so that pulsating pressure at the exhaust ports 6, 6 acts substantially equally on the right and left reed valves L, L. The secondary air supplying pipes 28, 28 are formed of a metal and plated on their surface with nickel, chromium or the like. As clearly shown in FIG. 5, each of the secondary air distribution passages 29 consists of a main passage 29 1 communicating with the secondary air supplying pipe 28 and a pair of branch passages 29 2 , 29 2 that are bifurcated at the inner end of the main passage 29 1 via an expansion chamber 30. The inner ends of the branch passages 29 2 , 29 2 communicate with the exhaust port 6 in the vicinity of the exhaust valve openings 15, 15.
The reed valve devices L are disposed at the right and left portions of the secondary air reservoir chamber Ch. Each valve device L comprises a reed valve body 31 and a valve cover 32 jointly secured to the secondary air reservoir chamber Ch by several mounting bolts 33. The secondary air reservoir chamber Ch defines an upstream chamber a of the reed valve device L and the valve cover 32 defines therein a downstream chamber b. The secondary air supplying pipe 28 is welded or brazed at one end to the downstream chamber b. A valve port 34 is formed in the reed valve body 31 with a reed 35 secured thereto for opening and closing the valve port 34. The reed 35 is forced under pulsations of exhaust gas to open in an increasing sense until it strikes a stopper 36 so that secondary air is permitted to flow only from the upstream chamber a to the downstream chamber b. When exhaust pulsations develop at the exhaust port 6 due to the operation of the internal combustion engine E, the reed 35 is caused under exhaust pulsations to open and close the valve port 34 to distribute the secondary air inside the upstream chamber a, or the secondary air reservoir chamber Ch, to the exhaust valve openings 15, 15 of the exhaust port 6 via the secondary air supplying pipe 28, the main passage 29 1 , the expansion chamber 30 and the branch passages 29 2 , 29 2 .
Now, the operation of the device of this embodiment will be described. When the multiple-cylinder internal cmbustion engine E is operated, the exhaust pulsating pressure is generated at the exhaust port 6. This pulsating pressure passes through the branch passages 29 2 , the expansion chambers 30, the main passages 29 1 and the secondary air supplying pipes 28 into the reed valve devices L to open the latter. Part of the clean air inside the air cleaner 8 is led into these two reed valve devices L via the secondary air intake pipe 21, the air control valve 22 and the main secondary air supplying pipe 25 and then, is directly introduced to the two exhaust ports 6 in the vicinity of the exhaust valves 17 via the secondary air supplying pipes 28, the main passages 29 1 , the expansion chambers 30 and the branch passages 29 2 . In this case, secondary air is directly distributed to each exhaust port 6 opening to the combustion chamber 4. Inside each exhaust port 6, exhaust gas and secondary air are uniformly mixed. Moreover, because the secondary air is directly fed to the exhaust ports 6 in the vicinity of the exhaust valve openings 15, the secondary air can be mixed with the high temperature exhaust gas, thereby further promoting the recombustion of the exhaust gas as a whole.
The secondary air, flowing into the expansion chamber 30, is once stored therein to stabilize its flow rate so that it is equally distributed to the branch portions of the exhaust port 6 via the secondary air distribution passages 29, 29. Accordingly, the secondary air can be fed in an optimal quantity for burning HC, CO and the like in the exhaust gas to effectively purify the exhaust gas.
The formation of the expansion chambers 30 in the cylinder head 2 increases freedom in arrangement of the secondary air supplying pipes 28 with respect to its mounting direction and position to facilitate the connection thereof to the secondary air distribution passages 29, 29 communicating with the branch portions of the exhaust ports 6. This arrangement is especially effective for the internal combustion engines of motorcycles having only a limited mounting space.
The present invention as described in the foregoing provides the following advantages. The reed valve devices are disposed in a dead space between the V-arranged two cylinders of the internal combustion engine without hindering the layout and maintenance of the other devices. As the regions around the reed valve devices are kept open, maintenance of the reed valve devices becomes easy.
Since the outlets of the reed valve devices and the exhaust ports of the engine communicate with one another by the secondary air supplying pipes surrounding the cylinders, each secondary air supplying pipe has only a limited outwardly protruding portion so as to avoid its contact with other portions and resulting damage. Furthermore, the head cover of the engine is detachable without any contact with the exhaust gas cleaning system so that maintenance, such as tappet adjustment, can be easily made.
If the secondary air supplying pipe is formed of metal, it can be plated with the same material as that of the exhaust pipe, e.g., nickel, chromium or the like, so as to match the external appearance thereof with other devices, thus improving the appearance of the engine as a whole equipped with the inventive exhaust gas cleaning system.
Since the reed valve devices are integrally fitted to the cylinders via the support member bridgingly connected to the two cylinders, the reed valve devices and the engine body always vibrate as an integral unit whereby the secondary air supplying pipe connected therebetween can be formed of a rigid metallic material because no excessive force acts thereupon, thus improving the durability and reliability.
The reed valve devices are kept open therearound for excellent coolability to prevent heat deterioration of the constituent components thereof, insuring the intended proper operation of the exhaust gas cleaning system for an extended period of time.
The secondary air supplying pipes, formed of a metallic material, may have one of the ends thereof integral with the reed valve devices so as to be used to form a part of the reed valve devices, and the other ends formed integral with the support member bridging the V-arranged two cylinders. With this arrangement, the secondary air supplying pipes can be readily attached to the reed valve devices and the engine body simply by fitting the opposite ends thereof to the reed valve devices and the engine body and fastening them by virtue of fastening means such as bolts, thus greatly enhancing the assemblability thereof. Since one of the ends of the secondary air supplying pipes are used also as the compenents for the reed valve devices while the other ends thereof are integral with the support member fixed to the engine body, the overall construction of the secondary air supplying system can be remarkably simplified to reduce the cost of production.
While a presently preferred embodiment of the invention has been shown and described, it will be clearly understood to those skilled in the art that various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.
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An exhaust gas cleaning system for an internal combustion engine including two cylinders arranged in V-shape and an exhaust system having exhaust ports. A secondary air supplying system is connected to the exhaust system for supply of secondary air. Reed valve devices responsive to an exhaust gas pulsation pressure are incorporated in the secondary air supplying system and are opened and closed under the action of exhaust gas pulsation developing during engine operation. The reed valve devices are disposed in a space defined between the two cylinders. The reed valve devices are connected to the exhaust ports through respective secondary air supplying pipes which form a part of the secondary air supplying system. The secondary air supplying pipes are wound so as to surround the respective cylinders.
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FIELD OF THE INVENTION
The invention relates to a cargo carrier suspension and, in particular, to a cargo carrier suspension having an adjustment for suspension resistance.
BACKGROUND OF THE INVENTION
Suspensions are provided on cargo carriers such as bicycle trailers or strollers. The suspension provides a smoother ride for the occupant or load. Sometimes, the suspension includes a means for resistance adjustment.
SUMMARY OF THE INVENTION
A cargo carrier suspension has been invented. The suspension acts between the cargo support area, for example the seat, and the transport means on which the carrier rides such as, for example, wheels, rollers, skis etc.
In accordance with a broad aspect of the present invention, there is provided a cargo carrier suspension for installation on a cargo carrier having a cargo support and a transport means on which the cargo support rides, the cargo carrier suspension comprising: a leaf spring connectable on a cargo carrier between the seat and the transport means; and a clamping device for engagement on the leaf spring and adjustable to select the degree of flexibility of the leaf spring.
In accordance with another broad aspect, there is provided a cargo carrier comprising: a cargo support; a transport means on which the cargo support is supported to ride; a suspension for damping vibration between the transport means and the cargo support, the suspension including a leaf spring connected to act between the cargo support and the transport means and a clamping device for engagement on the leaf spring and adjustable to select the degree of flexibility of the leaf spring.
The suspension acts between the cargo support and the transport means to damp vibration from the transport means to the cargo support. The cargo support can be, for example, a floor or a seat. The cargo support can be rigid or flexible, as formed of fabric. However, if the cargo support is flexible it includes a rigid member, such as a support frame, onto which the suspension is connectable. As an example, the cargo support can be rigid and the suspension connectable directly thereto, the cargo support can include a support frame to which the suspension is connectable or the cargo—support can be mounted in a frame for the cargo carrier and the suspension is connectable between the cargo carrier frame and the transport means. The transport means can be any apparatus on which the seat can ride. As an example, transport means can include wheels, skis and rollers.
The suspension is connectable to the cargo carrier in any way such as, for example, by forming integral therewith, by welding or fusing or by fasteners such as clamps, bolts, screws, straps or rivets.
The leaf spring can be formed of spring steel or other materials having resilient, spring properties such as, for example, polymers or metals. The leaf spring can include one leaf or a plurality of leaves forming a spring pack.
The clamping device is selected to be engageable on, and adjustable to select the degree of flexibility of, the leaf spring. In one embodiment, the clamping device acts to select the degree of flexibility of the leaf spring by controlling its free flexing length. In another embodiment, the clamping device acts to select the degree of flexibility of the leaf spring by controlling the stiffness of the spring, for example, as determined by the number of leaves acting in the spring pack or the frictional engagement of the plurality of springs in the spring pack. The clamp can be engageable on the leaf spring in various ways such as, for example, by bolting thereon, by engagement of a pin in a detent or by spring biasing.
BRIEF DESCRIPTION OF THE DRAWINGS
A further, detailed, description of the invention, briefly described above, will follow by reference to the following drawings of specific embodiments of the invention. These drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. In the drawings:
FIG. 1 is side elevation of a cargo carrier according to the present invention with a suspension;
FIG. 2 a is side elevation of a cargo carrier according to the present invention with a suspension;
FIG. 2 b is a perspective view of a suspension according to the present invention;
FIGS. 3 a , 3 b and 3 c are side elevations of the suspension of generally as shown in FIG. 2 in progressively flexed conditions;
FIG. 4 is a perspective view of another suspension according to the present invention;
FIG. 5 is a perspective view of another suspension according to the present invention; and
FIG. 6 is a perspective view of another suspension according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 there is shown a cargo carrier 10 in the form of a bicycle trailer for carrying a child. Cargo carrier 10 includes a frame 12 , a seat 14 supported on the frame and wheels 16 acting as transport means to support and permit transport of the carrier. While there are two wheels 16 on the cargo carrier, in the drawing one is disposed behind the other. The Illustrated cargo carrier Is specifically is a trailer for towing behind a bicycle, and therefore includes a tow arm 17 . It is to be understood that while a bicycle trailer has been shown, a cargo carrier according to the present invention can also be other forms of trailers, a stroller or a sled such as for example, a three or four wheeled stroller, a cargo trailer having a cargo support floor rather than a seat, a trailer having any number of wheels or a trailer for human towing such as a rickshaw.
The cargo carrier has further installed thereon a suspension 18 for damping vibration, which would tend to be transferred from wheels 16 to seat 14 . In particular, suspension 18 is connected between a wheel axle (cannot be seen) and frame 12 . The cargo carrier preferably has no rigid connection between wheels 16 and seat 14 such that the suspension is free to act.
The suspension includes a leaf spring 20 connected by bracket 22 adjacent its first end to a lower section 12 a of the frame. The leaf spring can be connected by other means such as by direct engagement by fasteners, welding, fusing or strapping, to the frame. However, care should be taken to ensure that the connection will accommodate the stress, which can be significant, without unacceptably low durability. The leaf spring is connected, again in any desired way, at its second end to the wheel axle. Again, while various connection arrangements are possible, care should be taken to address the material stress at this connection.
Leaf spring 20 is formed of any desired material having spring properties, but capable of supporting the frame. As an example, the leaf spring can be formed of spring steel, or polymeric materials. The leaf spring can include one or more spring leaves.
In the most usual arrangement, there is a leaf spring connected adjacent each wheel or at least each rear wheel of the cargo carrier. However, other arrangements can be used, such as one leaf spring centrally located between the wheels or a plurality of leaf springs spaced apart between the wheels and along the wheel axle or one or more leaf springs mounted up closer to the seat.
The wheel axle can be a common axle or cross member extending between the two wheels. Alternately, the leaf springs can be connected to an independent stub axle for each wheel. In such an embodiment, care should be taken to avoid twisting and fatigue of the leaf springs.
To provide some rigidity to the frame and to prevent a feeling of unstability, in one embodiment a stabilizer bar (cannot be seen in FIG. 1) is mounted to the lower frame 12 a . The stabilizer bar can be a member fastened to the lower frame or formed integral therewith. Of course, if the frame could be formed very rigid, this stabilizer bar could be omitted.
The suspension further includes a clamping device 24 that is engaged on leaf spring 20 and is adjustable to control the degree of flexibility in the spring and thereby the stiffness of the suspension. In one embodiment shown in FIGS. 1, 2 and 3 , the leaf spring is formed as a spring pack containing a plurality of spring leaves and the clamping device is adjustable to control the degree to which the plurality of spring leaves are connected to act together in the spring pack. In another embodiment shown in FIG. 4, the clamping device is adjustable to control the free flexing length of the spring. In yet another embodiment, the spring is formed as a spring pack containing a plurality of spring leaves and the clamping device is adjustable to control the degree of frictional engagement between the spring leaves, thereby adjusting the flexibility of the leaf spring.
It is useful to select the stiffness of a suspension to adjust the ride and/or to maintain a selected suspension flexibility, when the weight of the load is changed (i.e. to prevent the trailer from bottoming out when a heavier load is carried). In general, a stiffer suspension is desired when transporting a heavier load.
Referring to FIGS. 2 and 3, leaf spring 20 is formed as a spring pack containing a plurality of spring leaves 26 a , 26 b . While two leaves are shown, other numbers can be used as desired. As will be appreciated, each of the spring leaves will have a characteristic spring force or degree of flexibility. However, when connected to act together, the spring pack provides a degree of flexibility, which is greater than that of either of the spring leaves alone.
Spring leaves 26 a , 26 b are connected together at end 20 a by bracket 22 . This bracket also serves to connect leaf spring 20 to frame 12 b of a cargo carrier. The bracket includes an opening 28 for accepting frame 12 b therethrough and an opening 30 for leaves 26 a , 26 b . The bracket, spring leaves and frame include alignable apertures through which bolts 32 are inserted and secured by nuts 34 . Through this connection any force in leaves 26 a , 26 b at end 20 a will be transmitted to frame 12 b through the bracket.
Leaf spring 20 is connected at its opposite end 20 b to a bracket 36 . Bracket 36 includes an opening 38 in which a wheel axle 40 and a hollow axle 42 are secured. The bracket can be formed in any way to secure the axle and to serve other purposes such as, for example, in the illustrated embodiment, the bracket includes an extension 41 for retaining a parking brake.
While the bracket can be secured to the leaf spring in various ways such as by forming one integral with the other, fusing, welding, riveting, fastening etc, in the illustrated embodiment, bracket 36 is secured to leaf spring 20 via a flange 44 having apertures which can be aligned with apertures on the leaf spring 20 to accept bolts 46 and nuts 48 .
While leaf spring 20 includes a spring pack of leaves 26 a , 26 b , it is to be noted that only one of the leaves 26 a , is directly connected to bracket 36 and thereby to the wheels. The other spring leaf 26 b is only connected indirectly to the wheel through engagement by a clamping device 24 to spring leaf 26 a.
Clamping device 24 is engaged to leaf spring 20 and, in particular, secures spring leaf 26 b to spring leaf 26 a so that they can flex together. Clamping device 24 controls the degree to which the spring leaves are connected to act together in the spring pack in response to the application of force.
In the illustrated embodiment, clamping device 24 includes an opening 50 sized to accommodate the spring leaves in a such a way that the clamping device surrounds the spring leaves, but that the clamping device can be moved along the leaves if not engaged in a position. Clamping device 24 further includes a knob 52 with a threaded stem that is threadedly engaged in a threaded aperture (cannot be seen) through device 24 . The aperture is formed such that the stem can be threaded into opening 50 to engage against spring leaf 26 a to hold the clamping device in a selected position on leaf spring 20 and to clamp leaves 26 a , 26 b together. To adjust the position of the clamping device along the leaf spring, the stem can be withdrawn from engagement with leaf 26 a and the device can be slid along to another position. While one clamping device has been shown and described, it is to be understood that any device that operates to clamp the leaf springs together can be used. For example, a U-shaped clamp can be used in a similar fashion as device 24 , a bolt, or other removable fastener such as a clip or wire, can be inserted through a selected one of a plurality of aligned pairs of apertures formed through the spring leaves and a spring-biased pin could be used in place of the stem.
A stabilizer bar 55 is secured between lower frame member 12 b and the lower frame member on the other side of the trailer.
FIGS. 3 a to 3 c are provided to facilitate understanding of the invention. FIG. 3 a shows the suspension at a generally neutral position wherein insufficient force is applied to the cargo carrier wheel, and thereby to bracket 36 , to cause flexing of leaf spring 20 out of its neutral position. However, in FIG. 3 b some force is applied upwardly to the bracket to cause leaf spring to flex and in FIG. 3 c a force greater than the force in FIG. 3 b is applied to the bracket. The force could be, for example, that applied to the wheel by pulling or pushing the cargo carrier over a bump or curb.
Clamping device 24 is engaged at a selected position along leaf spring 20 and clamps leaves 26 a , 26 b together at this position. Thus, on one side of clamping device 24 , indicated as A, leaves 26 a , 26 b act together in response to applied force and exhibit a first degree of flexibility, while on the other side, B, spring leaf 26 a acts alone in response to applied force and exhibits a second degree of flexibility which is greater than that of portion A. This is illustrated in the drawings. When no force is applied to leaf spring 20 , as in FIG. 3 a , the leaves 26 a , 26 b remain in their neutral position. In the illustration, the leaf spring is maintained in a flexed position, termed preloading, to provide the spring with a selected stiffness, which is greater than the stiffness that it would have without the preload effect. Because of preloading, the spring leaves lie close together in the neutral position. While preloading is useful with some springs to accommodate a change in cargo weight (i.e. putting a child in the seat) without activating the suspension, it is to be noted that it is not necessary to preload the spring pack.
When force is applied to the wheel and thereby to the bracket, as shown in FIG. 3 b , spring 20 will flex to absorb the force. On side A, the leaves 26 a , 26 b being clamped together at both ends will flex together. However, on side B, leaf 26 a which is secured between device 24 and bracket 36 will separate from leaf 26 b and flex to an amount greater than that of side A. In FIG. 3 c , the applied force is greater and so the effect is greater.
The overall flexibility of leaf spring 20 is determined by the proportion of the spring that is acting as a leaf pack relative to the portion of the spring that is acting as a single spring. The flexibility of leaf spring 20 can, therefore, be adjusted by securing the clamping device at various positions along the spring. In particular, moving clamping device 24 closer to end 20 a , thereby reducing the length of side A, causes spring 20 to have increased flexibility, such as would be useful for carrying lighter loads, and moving the clamping device in the opposite direction, toward the bracket 36 and the free end of spring leaf 26 b , decreases the spring flexibility.
Markings 58 can be placed along a visible surface of the leaf spring as shown or on frame 12 b to guide a user on an appropriate placement of the clamping device 24 for a specified load. Leaf springs 26 a , 26 b can be treated or surface coated to enhance appearance or wear characteristics. In the illustrated embodiment, a rubber sheet 59 is secured to leaf spring 26 a to protect the surface of the spring and to enhance the grip between device 24 and the spring.
In the illustrated embodiment, frame 12 b extends out under leaf spring 20 . Although this is not necessary, as shown in FIG. 1, the frame in the embodiment of FIGS. 2 and 3 permits connection of some upper frame members (not shown) of the cargo carrier though aperture 60 . In addition, frame 12 b , underlying leaf spring 20 , limits the range of movement of the spring. In particular, the spring is free to flex upwardly, away from the frame, but is limited in its downward flex by abutment against the frame. Bumpers 62 a , 62 b , such as rubber or polymeric pads, can be secured between the leaf spring and the frame to reduce the noise caused by the spring hitting against the frame. In addition, bumpers, such as bumper 62 a , can be sized to urge the spring into a preload (preflexed) condition.
Referring to FIG. 4, another suspension is shown including a leaf spring 120 and a clamping device 124 . The clamping device 124 permits the flexibility of the leaf spring to be adjusted, depending on the clamped position of the clamping device along the leaf spring.
Leaf spring 120 includes one, as shown, or more spring leaves connected at one end by a bracket 122 to a frame 12 b of a cargo carrier. At its other end, spring 120 is connected to a bracket 36 for accepting a wheel axle (not shown) of a cargo carrier. If the leaf spring includes more than one spring leaf, all of the leaves are secured together to respond to application of force.
Leaf spring 120 extends adjacent to frame 12 b . Clamping device 124 includes an opening 170 sized to fit closely around both leaf spring 120 and frame 12 b to clamp them together. This clamping causes end 120 a to be fixed against flexing in response to application of force, while free end 120 b , between bracket 36 and clamping device 124 , is free to flex in response to any force applied. As will be appreciated, the length of end 120 b determines the stiffness of the suspension. In particular, as clamping device 124 is moved in direction B to shorten end 120 b , the stiffness of the suspension will increase and the flexibility of the leaf spring will decrease.
To permit the clamping device to be locked in a selected position, a spring-biased pin 172 is mounted to releasably engage in detents 174 on the leaf spring. Pin 172 is manipulated by grasping knob 176 .
In another embodiment shown in FIG. 5 the clamping device 124 a is secured to frame 12 c by a knob/fastener 180 . The fastener can be, for example, a bolt, a spring loaded pin or a push button. In yet another embodiment shown in FIG. 6, the clamping device 124 b is secured to frame 12 d by a lock pin 182 that is inserted through alignable apertures in the clamp and the frame.
It will be apparent that many other changes may be made to the illustrative embodiments, while falling within the scope of the invention and it is intended that all such changes be covered by the claims appended hereto.
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A cargo carrier suspension for installation on a cargo carrier having a seat and wheels, skis or rollers on which the seat rides, the cargo carrier suspension comprising: a leaf spring connectable on a cargo carrier between the seat and the wheels, skis or rollers, and a clamping device for engagement on the leaf spring and adjustable to select the degree of flexibility of the leaf spring.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is divisional application of U.S. patent application Ser. No. 10/428,605 filed May 2, 2003, which is a continuation of U.S. patent application Ser. No. 10/134,784, filed Apr. 29, 2002, which issued as U.S. Pat. No. 6,679,413 on Jan. 20, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 10/072,603 filed Feb. 7, 2002, which issued as U.S. Pat. No. 6,609,646 and which claimed the benefit of U.S. Provisional Application No. 60/267,359, filed Feb. 8, 2001. Other features of the present invention are discussed and claimed in commonly assigned U.S. Pat. Nos. 6,648,202 and 6,772,931.
FIELD OF THE INVENTION
[0002] The present invention generally relates to a pneumatically actuated device for driving fasteners fed from a magazine into a workpiece and more specifically to a pneumatic engine that employs a shifting cylinder sleeve to control the supply of air to and exhaust from the pneumatic engine.
BACKGROUND OF THE INVENTION
[0003] A number of pneumatically operated devices have been developed for use in driving fasteners, such as staples and nails, into workpieces. These tools typically include an engine, a triggering system, and a head valve for controlling the flow of air to the engine. The engine generally includes a piston that is housed in a liner or sleeve, wherein the piston is coupled to a rod that extends through the liner and out of the nose of the tool. The triggering system controls the flow of compressed air to the main valve. The main valve is normally open to the atmosphere. When the triggering system is actuated, the main valve opens, simultaneously closing the path to the atmosphere and venting high pressure air that will act against the piston. The piston is pushed so that the rod that is attached thereto will apply a force to a fastener and thereby drive the fastener into a Workpiece. When the triggering system is reset, or unactuated, the main valve closes, reopening the path to the atmosphere. The high pressure air that is over the piston is exhausted, allowing a charge of high pressure air that had been compressed by the movement of the piston to act against the opposite side of the piston to push it to its returned position.
[0004] Despite the wide spread use of such tools, several drawbacks have been noted. One such drawback concerns the main valve in that it adds a significant amount of weight and length to the tool. Another drawback concerns the mechanism by which the magazine assembly is mounted to the tool.
SUMMARY OF THE INVENTION
[0005] In one form, the teachings of the present invention provide a fastening tool that employs a unique head valve to reduce the weight of the fastening tool. In another form, the teachings of the present invention provide a method for operating a fastening tool. A fastening tool constructed in accordance with the teachings of the present invention may employ an engine with a sliding sleeve arrangement which can reduce the complexity of the pneumatic circuitry of the fastening tool and thereby reduce the overall weight and length of the tool.
[0006] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings, wherein:
[0008] FIG. 1 is a left side view of a tool constructed in accordance with the teachings of a preferred embodiment of the present invention;
[0009] FIG. 2 is a right side view of the tool of FIG. 1 ;
[0010] FIG. 3 is an exploded perspective view of the tool of FIG. 1 ;
[0011] FIG. 4 is a sectional view of the tool of FIG. 1 taken through its longitudinal axis;
[0012] FIG. 4 a is a section view taken along the line 4 a - 4 a of FIG. 4 ;
[0013] FIG. 5 is a top view of the tool of FIG. 1 ;
[0014] FIG. 6 is a sectional view taken along the line 6 - 6 of FIG. 5 ;
[0015] FIG. 7 is an enlarged portion of FIG. 4 illustrating the nose assembly in greater detail;
[0016] FIG. 8 is a front view of a portion of the tool of FIG. 1 illustrating the nose body and the contact tip in greater detail;
[0017] FIG. 9 is a sectional view taken along the line 9 - 9 of FIG. 2 ;
[0018] FIG. 9 a is sectional view of a portion of the magazine clamp assembly illustrating the spring collar in greater detail;
[0019] FIG. 9 b is a perspective view of a portion of the magazine clamp assembly illustrating the clamp pin in greater detail;
[0020] FIG. 10 is an enlarged portion of FIG. 4 illustrating the trigger assembly in greater detail;
[0021] FIG. 11 is an exploded view of the tool of FIG. 1 ;
[0022] FIG. 12 is an enlarged portion of FIG. 4 illustrating the rear of tool in greater detail;
[0023] FIG. 13 is a sectional view of a portion of the exhaust manifold illustrating the construction of the exhaust ports in greater detail;
[0024] FIG. 14 is an enlarged portion of FIG. 4 illustrating the engine assembly in greater detail;
[0025] FIG. 15 is an enlarged portion of FIG. 11 illustrating the engine assembly in greater detail;
[0026] FIG. 16 is a sectional view of the sleeve taken along its longitudinal axis;
[0027] FIG. 17 is a sectional view taken along the line 17 - 17 of FIG. 16 ;
[0028] FIG. 18 is a sectional view similar to that of FIG. 10 but illustrating the trigger assembly in an actuated condition;
[0029] FIG. 19 is an exploded perspective view of the magazine assembly;
[0030] FIG. 20 is a sectional view taken along the line 20 - 20 of FIG. 1 and illustrating the construction of the magazine body assembly;
[0031] FIG. 21 is a rear view of a portion of the magazine body assembly;
[0032] FIG. 22 is a side view of a portion of the magazine body assembly illustrating the L-shaped pin aperture in greater detail;
[0033] FIG. 23 is a top view of a guide structure;
[0034] FIG. 24 is a front view of the bracket structure;
[0035] FIG. 25 is a rear view of a portion of the bracket structure;
[0036] FIG. 26 is a side view of a portion of the bracket structure;
[0037] FIG. 27 is a side view of the follower structure;
[0038] FIG. 28 is a top view of a portion of the follower structure illustrating the construction of a portion of the follower body, the follower guide and the actuating lever;
[0039] FIG. 29 is a view of a portion of the follower structure illustrating the configuration of the forward leg of the follower body;
[0040] FIG. 30 is a view of a portion of the follower structure illustrating the configuration of the rearward leg of the follower body;
[0041] FIG. 31 is a front view of a portion of the follower structure;
[0042] FIG. 32 is a partial view of the follower structure from a side opposite the side which is illustrated in FIG. 27 ;
[0043] FIG. 32 a is a view similar to that of FIG. 32 but illustrating the leg of the cam follower engaged into the catch portion of the second loading cam;
[0044] FIG. 33 is a side view of the follower spring;
[0045] FIG. 34 is a side view of the magazine end cap assembly;
[0046] FIG. 35 is a sectional view of a portion of the end cap structure taken along the line 35 - 35 in FIG. 34 ;
[0047] FIG. 36 is a sectional view of a portion of the end cap structure taken along the line 36 - 36 in FIG. 35 ;
[0048] FIG. 37 is a top view of a portion of the end cap structure;
[0049] FIG. 38 is a front view of the cam follower;
[0050] FIG. 39 is a partial side view of the cam follower;
[0051] FIG. 40 is an enlarged portion of the cam follower illustrated in FIG. 38 ;
[0052] FIG. 41 is a partial side view of the cam follower illustrating the follower hook in greater detail;
[0053] FIG. 42 is a partial section view illustrating the position of the cam follower on the pivot structure just prior to contact between the loading cam and the follower hook;
[0054] FIG. 43 is a partial section view similar to that of FIG. 42 but illustrating the cam follower when the follower hook is contacting the first loading cam portion;
[0055] FIG. 44 is a side view of the follower structure engaged to the magazine end cap assembly;
[0056] FIG. 45 is a section view taken along the line 45 - 45 illustrating the follower hook disposed within the capture aperture;
[0057] FIG. 46 is a side view of a portion of a tool constructed in accordance with the teachings of the an alternate embodiment of the present invention illustrating the magazine assembly removed from the tool;
[0058] FIG. 47 is a side view similar to that of FIG. 46 but illustrating the magazine assembly coupled to the tool;
[0059] FIG. 48 is a perspective view similar to that of FIG. 9 b but illustrating an alternately constructed clamp pin; and
[0060] FIG. 49 is a partial front view similar to that of FIG. 24 but illustrating a bracket structure having an alternately constructed slotted pin aperture.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0061] With reference to FIG. 1 of the drawings, a fastening tool constructed in accordance with the teachings of the present invention is generally indicated by reference numeral 10 . Fastening tool 10 is illustrated to include a detachable magazine assembly 20 and a fastening tool portion 30 . The fastening tool portion 30 includes a nose assembly 40 , a housing assembly 42 , a cap assembly 44 , an engine assembly 46 and a trigger assembly 48 .
[0000] Nose Assembly
[0062] With reference to FIGS. 1 through 9 , the nose assembly 40 is illustrated to include a nose structure 50 , a contact trip 52 , a trigger lever 54 and a contact trip-return spring 56 . The nose structure 50 includes a nose body 60 , a pair of magazine stabilizing tabs 62 , a magazine flange 64 , a pair of magazine guide posts 66 , a mounting base 68 , a spring post 70 and a pair of contact trip guides 72 . The nose body 60 is generally U-shaped, with the legs 80 of the “U” being inwardly offset to form a semi-circular blade cavity 82 . The inwardly offset legs 80 of the nose body 60 also serve as a guide surface 84 for guiding the lower front portion 86 of the contact trip 52 . The contact trip guides 72 are coupled to the top of the nose body 60 and form a guide surface for guiding the portion 88 of the contact trip 52 that extends over the nose body 60 .
[0063] The magazine stabilizing tabs 62 are situated on opposite sides of the nose body 60 and are spaced apart by a predetermined distance. The magazine flange 64 is a generally flat structure that is coupled to the bottom of the nose body 60 and that includes a lock-out dog aperture 90 . The magazine guide posts 66 , which are cylindrically shaped in the particular embodiment illustrated, extend downwardly and rearwardly from the magazine flange 64 . The magazine stabilizing tabs 62 , magazine flange 64 and magazine guide posts 66 are discussed in greater detail, below.
[0064] The mounting base 68 is coupled to the magazine flange 64 and the nose body 60 and includes a pair of mounting apertures 94 , a nose seal groove 96 and a nose guide 98 . The nose guide 98 is generally cylindrically shaped and includes an internal cavity 100 that having a cross-section that is configured to receive the fastener F and which may include a fastener stop 102 which is configured to prevent the fasteners F from traveling rearwardly toward the engine assembly 46 . In the embodiment illustrated, the internal cavity 100 is generally semi-circular in shape but which includes a key-shaped fastener stop 102 . The nose seal groove 96 is formed around the outer perimeter of the nose guide 98 and is sized to receive a nose seal 104 , which is an O-ring seal in the particular embodiment illustrated. The spring post 70 is coupled to the top of the mounting base 68 and includes a boss 108 that is sized to fit within the contact trip-return spring 56 .
[0065] The contact trip 52 is fit over and slides on the nose body 60 , being guided thereon by the inwardly offset legs 80 of the nose body 60 and the contact trip guides 72 . Preferably, the effective length of the contact trip 52 is adjustable so as to permit the tool operator to vary the depth at which the tool 10 sets the fasteners F. A spring protrusion 110 , which is sized to engage the inside diameter of the contact trip-return spring 56 , is formed in the rear of the contact trip 52 . The contact trip-return spring 56 is set over the boss 108 on the spring post 70 and the spring protrusion 110 on the contact trip 52 and exerts a spring force that biases the contact trip 52 away from the spring post 70 . Forward motion of the contact trip 52 is checked by a contract trip stop 114 that is formed onto a side of the nose body 60 and which contacts the contact trip 52 at a predetermined point.
[0066] The trigger lever 54 is fixedly coupled to the contact trip 52 at a first end 120 and extends rearwardly from the nose structure 50 where a second end 122 engages the trigger assembly 48 in a conventional manner that is well known in the art. Briefly, the trigger assembly 48 includes a primary trigger 126 , a secondary trigger 128 and a trigger valve 130 that selectively controls the flow of compressed air to the engine assembly 46 . The primary trigger 126 is pivotably mounted to the housing assembly 42 and movable in response to the tool operator's finger. Movement of the primary trigger 126 will not, in and of itself, alter the state of the trigger valve 130 . Rather, the second end 122 of the trigger lever 54 must also move rearwardly and into contact with the secondary trigger 128 before the state of the trigger valve 130 is changed to permit compressed air to flow to the engine assembly 46 . A stop member 134 , which is configured to interact with the magazine assembly 20 in a matter that will be discussed in greater detail below, is coupled to the trigger lever 54 below the magazine flange 64 and extends inwardly toward the nose body 60 . In the particular embodiment illustrated, the stop member 134 is die-punched into the trigger lever 54 and is offset inwardly therefrom toward the nose body 60 .
[0000] Housing Assembly
[0067] Housing assembly 42 includes a unitarily formed housing 150 , a piston bumper 152 , a magazine clamp assembly 154 and a housing seal 156 , which is illustrated to be an O-ring seal in the example provided. The housing 150 includes a housing body 160 , a trigger housing 162 , a nose housing 164 and a handle portion 166 . The housing body 160 is a container-like structure having a front base 170 and an outwardly tapering sidewall 172 that cooperate to form a housing cavity 174 . The outwardly tapering sidewall 172 terminates at the rear of the housing body 160 at a rear housing face 176 , which in the particular embodiment illustrated, includes a housing seal groove 178 that is configured to receive the housing seal 156 . A guide bore 180 is formed into the inside face 182 of the housing cavity 174 and terminates at its forward end at a guide stop 184 . A nose guide aperture 188 is formed through the front base 170 of the housing body 160 .
[0068] The nose housing 164 is coupled to the front base 170 of the housing body 160 and extends forwardly therefrom. The nose housing 164 includes an upper shroud 200 , a pair of sidewalls 202 and a pair of spaced apart bosses 204 , each of which having a threaded aperture 206 . The upper shroud 200 , sidewalls 202 and spaced apart bosses 204 cooperate to locate the nose assembly 40 to the housing 150 and the nose guide 98 is inserted into the nose guide aperture 188 . Threaded fasteners 210 are placed through each of the mounting apertures 94 in the mounting base 68 and threadably engaged to the threaded apertures 206 in the spaced apart bosses 204 to fixedly but removably couple the nose assembly 40 to the housing 150 . The axis 212 of the threaded fasteners 210 is skewed toward the rear of the tool 10 , causing the threaded fasteners 210 to exert a clamping force that pushes the nose assembly 40 downwardly onto the spaced apart bosses 204 and rearwardly against the front face of the front base 170 to thereby compress the nose seal 104 and sealingly engage the nose structure 50 to the housing body 160 . The upper shroud covers the spring post 70 , the contact trip-return spring 56 and a portion of the rear of the contact trip 52 to prevent foreign objects from lodging between the rear of the contact trip 52 and the spring post 70 .
[0069] The handle portion 166 is preferably non-circular in shape and contoured to comfortably fit the hand of a tool operator. The distal end 250 of the handle portion 166 is enlarged so as to render the handle portion 166 less prone to slipping out of the tool operator's hand. With additional reference to FIG. 4 a , a clamp boss 252 is coupled to the forward face of the distal end 250 of the handle portion 166 . The clamp boss 252 includes a clamp boss base 254 that extends toward the front of the tool 10 , a clamp boss sidewall 256 that wraps around the perimeter of the clamp boss base 254 and an annular intermediate clamp boss wall 258 that cooperates with a portion of the clamp boss sidewall 256 to form a circular spring cavity 260 . The clamp boss base 254 and the clamp boss sidewall 256 cooperate to form a clamp cavity 262 into which the magazine clamp assembly 154 is disposed. A pair of U-shaped pin apertures 264 , which will be discussed in further detail below, are formed into an end of the clamp boss sidewall 256 .
[0070] The handle portion 166 intersects both the housing body 160 and the trigger housing 162 and includes an air inlet cavity 270 which extends through the distal end 250 of the handle portion 166 to receive a supply of compressed air. The air inlet cavity 270 extends through the handle portion 166 and into both the housing cavity 174 and the trigger housing 162 to permit the compressed air to be directed through the tool 10 in a predetermined manner that will be described in detail, below.
[0071] In the example provided, the magazine clamp assembly 154 is illustrated to include a clamp pin 300 , a compression spring 302 , a spring collar 304 , an actuating cam 306 and a coupling pin 308 . The clamp pin 300 includes a head portion 322 , a first body section 324 , which is coupled to the head portion 322 , and a second body section 326 that is coupled to the opposite end of the first body section 324 . The first body section 324 is generally cylindrically shaped and includes a pair of parallel flats 328 . The second body section 326 is generally cylindrically shaped but has an outer diameter that is smaller than that of the first body section 324 . The head portion 322 includes a frusto-conical abutting face 330 .
[0072] The spring collar 304 includes a first annular portion 340 having a diameter that is sized to fit within the compression spring 302 , and a second annular portion 342 that is relatively larger in diameter than the compression spring 302 and which has a flat contact surface 344 . A pin aperture 346 is formed through the spring collar 304 that is sized to receive the second body section 326 of the clamp pin 300 .
[0073] The actuating cam 306 has a base portion 350 and a leg portion 352 which are arranged relative to one another in an L-shape. The end of the base portion 350 opposite the intersection point 354 between the base and leg portions 350 and 352 includes a coupling pin aperture (not specifically shown) which is sized to engage the coupling pin 308 . The leg portion 352 of the actuating cam 306 is arcuate in shape and includes a plurality of gripping protrusions 356 or is otherwise textured on its inside surface so as to improve the tool operator's ability to move the actuating cam 306 in a desired direction. A slot 358 , which is sized to engage the second body segment 326 of the clamp pin 300 in a slip-fit manner, is formed into the actuating cam 306 through the base portion 350 and a portion of the leg portion 352 .
[0074] The clamp pin 300 extends through a pin aperture 360 formed into the clamp boss base 254 of the clamp boss 252 such that the second body section 326 extends into the spring cavity 260 . The compression spring 302 is positioned over the second body section 326 and into the spring cavity 260 . The spring collar 304 is placed over the second body section 326 such that the first annular portion 340 is disposed inside the compression spring 302 . The base portion 350 of the actuating cam 306 is positioned into contact with the flat contact surface 344 such that the second body segment 326 extends into the portion of the slot 358 that is formed into the base portion 350 of the actuating cam 306 . The coupling pin 308 , which is a roll-pin in the example illustrated, is positioned into one of the U-shaped pin apertures 264 and driven through the base portion 350 of the actuating cam 306 and into engagement with a pin aperture 364 in the second body segment 326 of the clamp pin 300 . Accordingly, the coupling pin 308 pivotably couples the actuating cam 306 to the clamp pin 300 . Rotation of the actuating cam 306 about the coupling pin 308 places the intersection point 354 into contact with the flat contact surface 344 , causing the spring collar 304 to compress the compression spring 302 and transmit a clamping force to the head portion 322 of the clamp pin 300 . When the actuating cam 306 has been pivoted sufficiently so as to place the leg portion 352 into contact with the flat contact surface 344 , the force exerted by the compression spring 302 urges the spring collar 304 against the leg portion 352 to releasably lock the actuating cam 306 in place. The clamp cavity 262 protects the actuating cam 306 from being contacted during the operation of the tool 10 , thereby guarding against the inadvertent unlocking or releasing of the actuating cam 306 .
[0075] In FIG. 10 , the trigger housing 162 is configured to receive the trigger assembly 48 and includes a supply port 370 , which is coupled to the air inlet cavity 270 to provide the trigger assembly 48 with a source of compressed air. A biasing port 372 extends from the trigger housing 162 through the guide bore 180 in the housing cavity 174 that permits the trigger assembly 48 to direct air to or exhaust air from the housing cavity 174 .
[0076] As shown in FIGS. 7 and 11 , the piston bumper 152 is a unitarily formed molded elastomeric structure. In the particular example illustrated, the piston bumper 152 has a cylindrical body portion 390 and an annular lip 392 . The cylindrical body portion 390 preferably includes a first annular bumper portion 396 and a second annular bumper portion 398 that is generally larger in diameter than the first annular bumper portion 396 and which is disposed between the first annular bumper portion 396 and the annular lip 392 . The annular lip 392 extends radially outwardly of the body portion 390 and includes a front abutting face 400 that is configured to abut the inside surface 402 of the housing body 160 and sealingly engage the front base 170 of the housing body 160 . The annular lip 392 also includes a rear abutting face 404 having a first annular lip portion 406 and a second annular lip portion 408 that lies radially outwardly of and recessed forwardly relative to the first annular lip portion 406 . The rear abutting face 404 and a cylindrically-shaped driver blade aperture 410 that extends through the center of the piston bumper 152 will be described in detail, below.
[0000] Cap Assembly
[0077] With reference to FIGS. 11 and 12 , the cap assembly 44 includes a cap housing 420 , an exhaust manifold 422 and a top bumper 424 . The cap housing 420 includes an outer cap wall 430 that is generally flat at the rear of the tool 10 , but folds over on its sides to form a cup-like container having a generally flat forward face 432 that is configured to engage the housing seal 156 to permit the cap housing 420 to be sealingly coupled to the rear of the housing 150 .
[0078] The cap housing 420 also includes a plurality of foot tabs 434 , a plurality of strengthening gussets (not specifically shown), an annular exhaust port wall 438 , an exhaust button 440 and a cylindrical locating hub 442 having a threaded aperture 444 formed therethrough. The foot tabs 434 extend forwardly from the flat portion of the outer cap wall 430 beyond the front face 432 by a predetermined distance. The outside diameter of the foot tabs 434 is sized such that the foot tabs 434 fit within the housing cavity 174 . The foot tabs 434 will be discussed in greater detail, below. The strengthening gussets are employed to couple both the foot tabs 434 or the outer cap wall 430 to the annular exhaust port wall 438 , which extends forwardly from the flat rear portion 446 of the outer cap wall 430 . The exhaust button 440 is an annular member that also extends forwardly from the flat rear portion 446 of the outer cap wall 430 but which is spaced apart from the annular exhaust port wall 438 and the locating hub 442 . A plurality of primary exhaust ports 450 are formed through the exhaust button 440 and a plurality of secondary exhaust ports 452 are formed through the portion of the outer cap wall 430 between the annular exhaust port wall 438 and the exhaust button 440 .
[0079] The exhaust manifold 422 is preferably unitarily formed from a molded from a plastic material and includes a center hub 460 , an annular spacing wall 462 and an annular manifold wall 464 . The center hub 460 is configured to fit between the exhaust button 440 and the locating hub 442 and includes a hub aperture 468 that is configured to engage the locating hub 442 in a slip fit manner. The annular spacing wall 462 is coupled to the forward-most portion of the center hub 460 and is spaced apart from the exhaust button 440 . The annular manifold wall 464 is coupled to the outer perimeter of the annular spacing wall 462 and includes a plurality of circumferentially extending exhaust slots 470 that are spaced around the circumference of the annular manifold wall 464 . The exhaust slots 470 are generally U-shaped and as best shown in FIG. 13 , have a rear edge 472 that tapers rearwardly and inwardly toward the center hub 460 .
[0080] Returning to FIGS. 11 and 12 , the top bumper 424 preferably includes a dampening member 480 that is molded from an elastomeric material, such as urethane, and a structural member 482 , such as a washer, that is molded into the dampening member 480 . The dampening member 480 is a cup-shaped structure that is sized to fit within the center hub 460 of the exhaust manifold 422 . The dampening member 480 includes an annular wall 484 that extends forwardly from the base 486 of the dampening member 480 . A ridge 488 is formed into the forward end of the annular wall 484 , thereby creating a groove 490 between the base 486 of the dampening member 480 and the ridge 488 . A plurality of slits 492 are formed into the annular wall 484 , creating a plurality of wall segments 494 that are flexibly coupled to the base 486 . A threaded fastener 496 is threadably engaged to the threaded aperture 444 in the locating hub 442 to fixedly but removably couple the top bumper 424 to the cap housing 420 . The structural member 482 is employed so as to permit the clamping force that is exerted by the threaded fastener 496 to be transmitted through the top bumper 424 without crushing the base 486 of the dampening member 480 . A portion of the clamping force is transmitted through the base 486 of the dampening member 480 and into the center hub 460 of the exhaust manifold 422 to maintain the exhaust manifold 422 in a stationary position relative to the cap housing 420 .
[0000] Engine Assembly
[0081] Engine assembly 46 is shown to include a cylinder assembly 500 , a piston assembly 502 , a rod or driver blade 504 . The cylinder assembly 500 includes a hollow, cylindrical, and unitarily constructed sleeve 510 , an inner exhaust port seal 512 , an outer exhaust port seal 514 , a cap flange seal 516 , rear and front guide seals 518 and 520 , a guide assembly 522 , a compensating valve 524 , a rear spring flange 526 , a spring 528 , a front spring flange 530 and a front spring flange seal 532 . In the particular embodiment illustrated, inner exhaust port seal 512 , outer exhaust port seal 514 , rear and front guide seals 518 and 520 and front spring flange seal 532 are conventional, commercially available O-ring seals. The cap flange seal 516 is a molded elastomeric seal having an outside surface with a generally flat seal face 540 and first and second radially inwardly extending flanges 542 and 544 , respectively, that are spaced apart from one another to form an engagement groove 546 therebetween.
[0082] With additional reference to FIG. 16 , the sleeve 510 is shown to include a first sleeve body portion 550 , an annular sleeve flange 552 , a second sleeve body portion 554 having a maximum outer diameter that is generally the same as that of the first sleeve body portion 550 and a third sleeve body portion 556 having a maximum outer diameter that is generally larger than that of the first sleeve body portion 550 . The first sleeve body portion 550 includes a first U-shaped seal groove 560 , which is sized to receive the front spring flange seal 532 , a plurality of circumferentially-spaced front exhausting ports 562 , a spring flange groove 564 , which is sized to receive the rear spring flange 526 , a valve groove 566 , which is discussed in greater detail, below, and a second U-shaped seal groove 568 , which is sized to receive the front guide seal 520 .
[0083] The valve groove 566 has a first U-shaped portion 570 , a second U-shaped portion 572 and a plurality of valve apertures 574 . The first U-shaped portion 570 is sized to receive the compensating valve 524 , which in the particular embodiment illustrated, is a flat elastomeric band 580 . The second U-shaped portion 572 is disposed within the first U-shaped portion 570 , but has a diameter that is somewhat smaller than that of the first U-shaped portion 570 so as to define an annular ring that extends around the circumference of the first U-shaped portion 570 . In the particular embodiment illustrated, the diameter of the second U-shaped portion 572 is about 0.010 inches to about 0.030 inches smaller in diameter than the first U-shaped portion 570 . The valve apertures 574 are illustrated to be relatively small diameter holes that are located within the second U-shaped portion 572 and which are drilled through the sleeve 510 . The valve apertures 574 will be discussed in greater detail, below, as will the set of front exhausting ports 562 that are located between the first U-shaped seal groove 560 and the spring flange groove 564 .
[0084] The annular sleeve flange 552 extends radially outwardly from the first sleeve body portion 550 of the sleeve 510 and separates the first and second sleeve body portions 550 and 554 from one another. A third U-shaped seal groove 584 , which is sized to receive the rear guide seal 518 is formed into the outer surface of the annular sleeve flange 552 .
[0085] The majority of the second sleeve body portion 554 of the sleeve 510 is of approximately the same outer diameter as the first sleeve body portion 550 . The rear end of the second sleeve body portion 554 , however, includes a flange portion 590 that extends radially outwardly to form a seal lip 592 and a fourth U-shaped seal groove 594 prior to its connection with the third sleeve body portion 556 . The seal lip 592 is configured to engage the engagement groove 546 formed into the cap flange seal 516 and abut the first and second radially inwardly extending flanges 542 and 544 . The fourth U-shaped seal groove 594 is configured to receive a portion of the first radially inwardly extending flange 542 .
[0086] The third sleeve body portion 556 is fixedly coupled to the end of the second sleeve body portion 554 and is larger in diameter than the outer diameter of the first sleeve body portion 550 . A fifth U-shaped seal groove 600 is formed into the outer surface of the third sleeve body portion 556 and is sized to receive the outer exhaust port seal 514 . A plurality of circumferentially extending rear exhaust slots 604 are disposed around the perimeter of the third sleeve body portion 556 . The rear exhaust slots 604 are located between the fourth and fifth U-shaped seal grooves 594 and 600 . A sixth U-shaped seal groove 608 , which is configured to receive the inner exhaust port seal 512 , is formed into the inner diameter of the third sleeve body portion 556 .
[0087] The hollow cavity 610 that is formed through the sleeve 510 has a first cavity portion 612 that is generally of a constant diameter over the portion of its length that includes the first and second sleeve body portions 550 and 554 and the annular sleeve flange 552 . The hollow cavity 610 also has a second cavity portion 614 having a larger diameter than that of the first cavity portion 612 .
[0088] In FIG. 14 , the guide assembly 522 is shown to include a guide 650 and first and second housing seals 652 and 654 , which in the particular embodiment illustrated, are O-ring seals. The guide 650 is a molded plastic component, having a stepped-diameter body portion 660 , a plurality of longitudinally extending legs 662 , a locating tab 664 and a plurality of stop tabs 668 . The stepped-diameter body portion 660 includes a flange bore 670 , which is sized to receive the annular sleeve flange 552 and sealingly engage the rear guide seal 518 , a body bore 672 , which is sized to receive the first sleeve body portion 550 and sealingly engage the front guide seal 520 , and an abutting flange 676 that forms the transition between the flange bore 670 and the body bore 672 .
[0089] The longitudinally extending legs 662 extend away from the stepped-diameter body portion 660 and are spaced apart circumferentially in equal amounts. The locating tab 664 is positioned on the same side of the stepped-diameter body portion 660 as the longitudinally extending legs 662 between two of the longitudinally extending legs 662 . The locating tab 664 is employed to signify the presence of an air gallery 680 and locate the guide assembly 522 relative to the housing assembly 42 . The air gallery 680 is configured to permit air to flow through the stepped-diameter body portion 660 from a point between the first and second housing seals 652 and 654 through the stepped-diameter body portion 660 and out the abutting flange 676 .
[0090] The rear and front guide seals 518 and 520 and the elastomeric band 580 that forms a portion of the compensating valve 524 are initially installed to the sleeve 510 . Thereafter, the guide assembly 522 is positioned over the first sleeve body portion 550 and pushed onto the sleeve 510 such that the flange bore 670 and body bore 672 are sealingly engaged to the rear and front guide seals 518 and 520 , respectively, and the abutting flange 676 abuts the annular sleeve flange 552 .
[0091] The rear spring flange 526 is next installed to the sleeve 510 . The rear spring flange 526 is a plastic collar that is split on one side to permit the ends of the rear spring flange 526 to be spread apart so that it may be loaded onto the first sleeve body portion 550 of the sleeve 510 and into the spring flange groove 564 . The rear spring flange 526 has a cylindrically shaped body portion 690 and a flange portion 692 that extends radially-outwardly from the body portion 590 in a manner that provides the rear spring flange 526 with a L-shaped cross-section. The rear spring flange 526 is located to the spring flange groove 564 such that the flange portion 692 is nearest the annular sleeve flange 552 .
[0092] The front spring flange 530 is a plastic collar having a tapering outside diameter 596 and a generally flat rear face 698 . The inside surface 700 of the front spring flange 530 is generally cylindrical, but includes an annular protrusion 702 that extends radially inwardly of the remainder of the inside surface 700 and which engages the first sleeve body portion 550 of the sleeve 510 in a slip-fit manner.
[0093] The spring 528 is a conventional compression spring having both ends ground flat. The spring 528 is disposed over the first sleeve body portion 550 of the sleeve 510 such that its rear end abuts the flange portion 692 of the rear spring flange 526 . Thereafter, the front spring flange 530 is positioned such that its rear face 698 contacts the second end of the spring 528 . The front spring flange 530 is pushed toward the annular sleeve flange 552 to compress the spring 528 a sufficient distance to permit the front spring flange seal 532 to be inserted into the first U-shaped seal groove 560 . Thereafter, the front spring flange 530 is moved toward the front of the sleeve 510 such that the front spring flange seal 532 is sealingly engaged with the inside surface 700 of the front spring flange 530 . The rear side of the front spring flange seal 532 contacts the annular protrusion 702 to limit the forward travel of the front spring flange 530 prior to the installation of the engine assembly 46 to the housing assembly 42 . Forward motion of the guide assembly 522 along the sleeve 510 is checked by contact between the stop tabs 668 and the rear surface of the flange portion 692 of the rear spring flange 526 to thereby prevent the guide 650 from becoming disengaged from the rear and front guide seals 518 and 520 . Construction in this manner is highly advantageous in that it permits the entire cylinder assembly 500 to be pre-assembled outside of the housing assembly 42 in a relatively easy and cost efficient manner.
[0094] The piston assembly 502 includes a piston 720 and a ring 722 . In the example provided, the piston 720 is shown to include a first piston portion 730 and a second piston portion 732 . The first piston portion 730 in an annular member that is smaller in diameter than the first cavity portion 612 of the hollow cavity 610 in the sleeve 510 . A U-shaped annular ring groove 734 is formed around the circumference of the first piston portion 730 that is sized to receive the ring 722 . In the embodiment illustrated, the ring 722 is shown to be fabricated from a plastic material and have a rectangular cross-section. The ring 722 is split to permit its ends of the ring 722 to be spread apart so that it may be loaded around the first piston portion 730 and into the ring groove 734 . The second piston portion 732 is an annular member that is smaller in diameter than the first piston portion 730 . The second piston portion 732 is coupled to the rear end of the first piston portion 730 and includes a pair of wrench flats 740 and a locking protrusion 744 , both of which will be discussed in more detail, below. A generous fillet radius 746 is employed at the intersection between the first and second piston portions 730 and 732 so as to reduce the concentration of stress within the piston 720 .
[0095] The construction of the driver blade 504 is largely conventional and as such, a detailed discussion of it is neither required nor within the scope of this disclosure. Briefly, the driver blade 504 is shown to include a coupling portion 760 and a driver body 762 . In the example provided, the coupling portion 760 includes a collar 764 and a threaded portion 766 which are formed into the rear end of the driver blade 504 . The wrench flats 740 on the second piston portion 732 are employed to facilitate relative rotation between the driver blade 504 and the piston 720 to permit the threaded portion 766 to threadably engage a threaded aperture 768 that is formed through the piston 720 and to permit the collar 764 to engage the front surface 770 of the piston 720 to generate a clamping force that fixedly but removably couples the piston 720 and the driver blade 504 together. Coupling of the piston 720 and the driver blade 504 via a threaded connection is presently preferred so as to permit the servicing and replacement of the driver blade 504 , since this portion of the tool 10 is essentially perishable. Those skilled in the art will understand from this disclosure, however, that other coupling mechanisms, such as press-fitting, shrink fitting, welding, or any other mechanical coupling method may also be employed.
[0096] The driver body 762 is sized to fit in the blade cavity 82 and is shown to include a keyway 774 , a slide surface 776 , a loading groove 778 and a tip portion 780 . The keyway 774 is illustrated to be a cut that is formed into the surface of the driver body 762 along its longitudinal axis. The fastener stop 102 that is formed into the internal cavity 100 in the nose guide 98 is disposed within the keyway 782 to guard against a situation wherein fasteners F feed rearwardly into the tool 10 . The slide surface 776 is generally flat and provides the driver body 762 with a relatively large surface that will consistently slide over the fasteners F that are loaded into the magazine assembly 20 . The tip portion 780 is formed at the front end of the driver body 762 and is operable for contacting the fasteners F and driving them into a workpiece. The loading groove 778 is cylindrically shaped and is formed along an axis that is skewed to the longitudinal axis of the driver blade 504 such that it intersects both the tip portion 780 and the slide surface 776 . The loading groove 778 is tapered such that it is deepest at the front of the driver blade 504 . The loading groove 778 ensures that only one fastener F is sheared from the remaining fasteners F in the magazine assembly 20 . The loading groove 778 also permits the fasteners F in the magazine assembly 20 to move upwardly toward the nose body 60 of the tool 10 prior to the time at which the driver blade 504 has stroked back to its rear-most (i.e., retracted) position to thereby minimize the lag time between the point at which the driver blade 504 has moved to its retracted position and the point at which the driver blade 504 can be moved forwardly to drive another fastener F.
[0097] With additional reference to FIGS. 16 and 17 , the driver blade 504 and the piston assembly 502 , once coupled to one another, are inserted into the second cavity portion 614 of the hollow cavity 610 in the sleeve 510 . The diameter of the second cavity portion 614 is larger than the diameter of the piston assembly 502 (with the ring 722 in an expanded condition). A chamfer 790 is employed at the front of the second cavity portion 614 to facilitate the transition to the smaller-diameter first cavity portion 612 . With the exertion of light force onto the rear of the piston assembly 502 , the piston assembly 502 is moved forwardly in the hollow cavity 610 and into contact with the chamfer 790 . The chamfer 790 is operable for compressing the ring 722 to permit the piston assembly 502 to travel into the first cavity portion 612 .
[0098] Once assembled, the engine assembly 46 is placed into the housing cavity 174 such that the locating tab 664 is aligned to a tab slot 800 formed into the housing cavity 174 and the driver blade 504 is inserted through the driver blade aperture 410 in the piston bumper 152 and into the internal cavity 100 in the nose guide 98 . The engine assembly 46 is pushed forwardly into the housing cavity 174 to engage the guide assembly 522 against the guide stop 184 . In this position, the first and second housing seals 652 and 654 sealingly engage the guide bore 180 that is formed into the inside surface 182 of the outwardly tapering sidewall 172 . The first and second annular bumper portions 396 and 398 extend through the front face 810 of the sleeve 510 and into the hollow cavity 610 . The front face 820 of the front spring flange 530 sealingly contacts the second annular lip portion 408 on the piston bumper 152 . The cap assembly 44 is thereafter placed onto the rear end of the housing assembly 42 such that each of the longitudinally extending legs 662 contacts one of the foot tabs 434 . The foot tabs 434 cooperate with the longitudinally extending legs 662 to prevent the guide assembly 522 from moving along the longitudinal axis of the tool 10 . The sleeve 510 , however, is slidable within the guide assembly 522 , as will be discussed in greater detail, below.
[0099] Alternatively, the piston assembly 502 and driver blade 504 may be inserted into the housing cavity 174 such that the driver blade 504 is inserted through the driver blade aperture 410 in the piston bumper 152 and into the internal cavity 100 in the nose guide 98 . The cylinder assembly 500 is then loaded into the housing cavity 174 in the manner discussed above. A lead L formed into the front face 810 of the sleeve 510 that permits the ring 722 to be compressed so that the piston assembly 502 can travel rearwardly into the first cavity portion 612 of the hollow cavity 610 in the sleeve 510 .
[0000] Engine Operation
[0100] With reference to FIGS. 10, 14 and 16 , when the tool 10 has been coupled to a source of compressed air, the trigger assembly 48 maintains the trigger valve 130 in an unactuated state wherein compressed air is directed from the supply port 370 to the biasing port 372 where it enters the air gallery 680 at a point between the first and second housing seals 652 and 654 . Compressed air flows through the stepped-diameter body portion 660 and exits from the abutting flange 676 where it enters a sleeve return chamber 850 that is defined by the forward face 852 of the annular sleeve flange 552 , the rear guide seal 518 , the flange bore 670 , the body bore 672 , the front guide seal 520 and the first sleeve body portion 550 of the sleeve 510 . As the guide 650 is not movable within the housing 150 , the pressure of the air that is in the sleeve return chamber 850 is exerted against the front face 852 of the annular sleeve flange 552 to bias the sleeve 510 in a rearward direction.
[0101] The air inlet cavity 270 also provides compressed air to a sleeve extend chamber 860 that is defined by the rearward face 862 of the annular sleeve flange 552 , the rear guide seal 518 , the guide 650 , the second housing seal 654 , the portion of the outwardly tapering sidewall 172 that is situated rearwardly of the second housing seal 654 , the outer portion of the cap housing 420 that includes the annular exhaust port wall 438 , the cap flange seal 516 and the second sleeve body portion 554 of the sleeve 510 . Compressed air in the sleeve extend chamber 860 directs force to both the rearward face 862 of the annular sleeve flange 552 and the front face 864 of the flange portion 590 of the second sleeve body portion 554 of the sleeve 510 .
[0102] The forces that act on the annular sleeve flange 552 and the front face 864 of the flange portion 590 , in cooperation with the force that is exerted by the spring 528 , bias the sleeve 510 in a rearward direction into its retracted position such that the flat seal face 540 of the cap flange seal 516 sealingly engages the front face 866 of the annular exhaust port wall 438 .
[0103] With reference to FIGS. 10 and 12 , when the sleeve 510 is in the retracted position, a primary exhaust chamber 870 is defined by the cap flange seal 516 , the inside surface 872 of the annular exhaust port wall 438 , the outer exhaust port seal 514 , the third sleeve body portion 556 of the sleeve 510 , the inner exhaust port seal 512 , the exhaust manifold 422 , the second sleeve body portion 554 of the sleeve 510 , the piston assembly 502 and the driver blade 504 . The position of the sleeve 510 relative to the cap assembly 44 is such that the air that is in the primary exhaust chamber 870 is permitted to flow between the third sleeve body portion 556 and exhaust manifold 422 , through the exhaust slots 470 in the exhaust manifold 422 and out the primary exhaust ports 450 in the exhaust button 440 where this air is vented to atmosphere.
[0104] With the sleeve 510 in the retracted position, a secondary exhaust chamber 880 is formed by the annular exhaust port wall 438 , the outer exhaust port seal 514 , the third sleeve body portion 556 of the sleeve 510 , the inner exhaust port seal 512 , the exhaust manifold 422 , the exhaust button 440 and the portion of the outer cap wall 430 between the annular exhaust port wall 438 and the exhaust button 440 . Air that is in the secondary exhaust chamber 880 is vented to the atmosphere through the primary exhaust ports 450 in the exhaust button 440 and through the secondary exhaust ports 452 in the portion of the outer cap wall 430 between the annular exhaust port wall 438 and the exhaust button 440 .
[0105] With reference to FIGS. 12, 14 and 18 , when the trigger assembly 48 is actuated to change the state of the trigger valve 130 to an actuated state, air in the sleeve return chamber 850 is vented through the trigger assembly 48 to the atmosphere. Consequently, the force that is exerted onto the rear face 862 of the annular sleeve flange 552 causes the sleeve 510 to slide forwardly relative to the housing assembly 42 . When the sleeve 510 slides in a forward direction, the seal between the cap flange seal 516 and the front face 866 of the annular exhaust port wall 438 is broken, permitting compressed air to flow through the rear exhaust slots 604 in the third sleeve body portion 556 of the sleeve 510 . As the area of the front surface 900 of the rear exhaust slots 604 is larger than the area of its rear surface 902 , the pressure of the air flowing through the rear exhaust slots 604 also tends to push the sleeve 510 in a forward direction. The piston bumper 152 checks forward travel of the sleeve 510 . More specifically, forward travel of the sleeve 510 is checked when the front face 810 of the sleeve 510 contacts the first annular lip portion 406 of the piston bumper 152 .
[0106] Simultaneous with the forward motion of the sleeve 510 , the inner exhaust port seal 512 slides forwardly by an equal amount to sealingly engage the outer circumference 910 of the exhaust manifold 422 at a point forward of the exhaust slots 470 to thereby prevent air from flowing to the atmosphere through the exhaust slots 470 . Pressure acts on the rear surface 920 of the piston assembly 502 to disengage the locking protrusion 744 in the second piston portion 732 from the groove 490 in the top bumper 424 . The pressure acts on the piston assembly 502 to drive the piston assembly 502 and the driver blade 504 forwardly through the first cavity portion 612 of the hollow cavity 610 in the sleeve 510 . Air in the first cavity portion 612 is compressed by the forward motion of the piston assembly 502 , causing it to be expelled from the hollow cavity 610 through the internal cavity 100 in the nose guide 98 , as well as through the front exhausting ports 562 and into a frontal air chamber 940 . The frontal air chamber 940 is defined by the first sleeve body portion 550 of the sleeve 510 , the front guide seal 520 , the guide 650 , the first housing seal 652 , the outwardly tapering wall 172 of the housing body 160 , the second annular lip portion 408 of the annular lip 392 in the piston bumper 152 , the front spring flange 530 and the front spring flange seal 532 .
[0107] The piston bumper 152 checks the forward motion of the sleeve 510 . Thereafter, the piston assembly 502 pushes the driver blade 504 forwardly so that the tip portion 780 drives a fastener F into a workpiece (not shown). With the piston bumper 152 also checks the forward motion of the piston assembly 502 and effectively seals against the front surface 770 of the piston assembly 502 to seal the frontal air chamber 940 . In this condition, the piston assembly 502 is positioned forwardly of the valve apertures 574 in the first sleeve body portion 550 of the sleeve 510 . Accordingly, if the pressure of the air in the portion of the hollow cavity 610 that is rearward of the piston assembly 502 is greater than the pressure of the air in the frontal air chamber 940 , the compensating valve 524 permits air to flow through the sleeve 510 and into the frontal air chamber 940 so as to balance the air pressure that is acting on the front and rear surfaces 770 and 920 of the piston assembly 502 . The compensating valve 524 , however, is a one-way valve that does not permit air to flow from the frontal air chamber 940 through the valve apertures 574 and into the hollow cavity 610 .
[0108] Referring back to FIGS. 10, 12 , 14 and 16 , when the state of the trigger valve 130 is changed to its unactuated state, compressed air is once again routed to the sleeve return chamber 850 where it applies a force against the front face 852 of the annular sleeve flange 552 . The balance of the forces on the sleeve 510 is such that the sleeve 510 is pushed in a rearward direction until the cap flange seal 516 sealingly engages the front face 866 of the annular exhaust port wall 438 . Air in the primary and secondary exhaust chambers 870 and 880 is then vented to the atmosphere in the manner discussed above.
[0109] The piston assembly 502 , immediately prior to the exhausting of the air in the primary and secondary exhaust chambers 870 and 880 , was such that it remained in sealed engagement with the piston bumper 152 . When the air in the primary exhaust chamber 870 is vented to the atmosphere, however, the pressure in the frontal air chamber 940 generates a force on the front surface 770 of the piston assembly 502 that exceeds the force that is acting on its rear face 920 . As mentioned above, the compensating valve 524 is a one-way valve that prevents air from flowing through the valve apertures 574 and into the hollow cavity 610 and as such, the pressure of the air to the rear of the piston assembly 502 is less than the pressure of the air in the frontal air chamber 940 . Accordingly, the pressure acting on the front surface 770 of the piston assembly 502 drives the piston assembly 502 rearwardly until the locking protrusion 744 in the second piston portion 732 engages the groove 490 in the top bumper 424 .
[0110] Those skilled in the art will understand from this disclosure that while the above-described configuration of the engine assembly 46 results in a relatively lighter-weight tool as compared with pneumatic fastening devices that employ a conventional head valve, the reduction in the weight of the tool 10 does not come at the expense of increased recoil that is felt by the tool operator. In this regard, the felt force that is exerted onto the cap assembly 44 when a fastener F is driven into a workpiece is counteracted by the felt force that is exerted by the sliding of the sleeve 510 in a forward direction.
[0000] Magazine Assembly
[0111] The magazine assembly 20 is shown to include a magazine body assembly 1000 , a follower structure 1002 , a follower spring 1004 and a magazine endcap assembly 1006 . The magazine body assembly 1000 includes a magazine housing 1010 , a pair of guide structures 1012 a and 1012 b and a coupling bracket 1014 . In the example illustrated, the magazine housing 1010 is extruded from a lightweight material, such as aluminum and includes a wall member 1020 that defines a fastener head portion 1022 , a follower housing portion 1024 , a pair of guide housing portions 1026 and a fastener body portion 1028 .
[0112] The fastener head portion 1022 is generally rectangular in shape, defining a fastener head chamber 1030 that is open at its top and bottom ends so as to permit the head portion H of the fasteners F to travel through the fastener head portion 1022 . The fastener head portion 1022 is also open along a portion of one of its sides 1032 so as to permit the follower structure 1002 to travel upwardly within the magazine housing 1010 . With additional reference to FIG. 21 , a threaded fastener 1034 is threadably engaged to the wall member 1020 , forming a contact surface 1036 that checks the upward travel of the follower structure 1002 .
[0113] As shown in FIGS. 19, 20 and 22 , the follower housing portion 1024 is coupled to the forward side of the fastener head portion 1022 and defines a generally rectangular follower cavity 1040 that is sized to receive the follower structure 1002 and the follower spring 1004 . A slot 1042 is formed into the rear surface 1044 of the follower housing portion 1024 . The slot 1042 interconnects the follower cavity 1040 to the fastener head chamber 1030 . An L-shaped pin aperture 1050 is formed into a side of the follower housing portion 1024 . The L-shaped pin aperture 1050 includes a relatively narrow first portion 1052 that extends generally parallel the longitudinal axis of the follower housing portion 1024 and a second portion 1054 that is skewed to the first portion 1052 . The L-shaped pin aperture 1050 will be discussed in greater detail, below.
[0114] In FIGS. 19 and 20 , each guide housing portion 1026 is shown to include a pair of spaced apart and arcuate protrusions 1060 a and 1060 b that are coupled to the wall member 1020 . The arcuate protrusions 1060 a and 1060 b cooperate with the wall member 1020 to define a guide structure cavity 1062 that extends over the length of the magazine housing 1010 and which is configured to receive one of the guide structures 1012 a and 1012 b . In the particular embodiment illustrated, the guide structure cavity 1062 includes a first cavity portion 1064 that is generally cylindrically shaped and located proximate the follower housing portion 1024 , and a second cavity portion 1066 that is shaped as a generally flat void that is generally tangent to the cylindrically shaped first cavity portion 1064 .
[0115] The fastener body portion 1028 is generally U-shaped, being coupled to the forward portion of the pair of guide housing portions 1026 . The fastener body portion 1028 includes a U-shaped fastener body cavity 1070 that is configured to receive the body B of the fasteners F. A plurality of oval windows 1072 are formed into the sides 1074 of the fastener body portion 1028 which permit the tool operator to monitor the quantity of fasteners F that are housed in the magazine assembly 20 , as well as to reduce the overall weight of the magazine assembly 20 .
[0116] As guide structures 1012 a and 1012 b are generally identical in construction, reference numerals may occasionally be shown on only of the guide structure 1012 a and 1012 b . Those skilled in the art will understand from this disclosure, however, that guide structure 1012 b is a mirror image of guide structure 1012 a . In the embodiment illustrated in FIGS. 19, 20 and 23 , each of the guide structures 1012 a and 1012 b includes a cylindrically-shaped guide port 1100 , first and second retention tabs 1102 and 1104 , respectively, an intermediate member 1106 and an end member 1108 . The guide port 1100 is generally hollow, having an outside diameter that is sized to slip fit into the first cavity portion 1064 of an associated one of the guide housing portions 1026 and an inside diameter that is to engage an associated one of the magazine guide posts 66 . The first retention tab 1102 is coupled to the guide port 1100 on one side and to the intermediate member 1106 on the opposite side. The second retention tab 1104 is coupled to the intermediate member 1106 on the side opposite the first retention tab 1102 . The intermediate member 1106 is sized to fit between the arcuate protrusions 1060 a and 1060 b in the guide housing portion 1026 as well as to space the first and second retention tabs 1102 and 1104 apart from one another by a predetermined distance that permits the first and second retention tabs 1102 and 1104 to engage the arcuate protrusions 1060 a and 1060 b when the guide structures 1012 a and 1012 b are inserted into the guide structure cavities 1062 . The inner surface 1110 of the second retention tab 1104 extends inwardly further toward the centerline 1112 of the magazine housing 1010 than the inside surfaces of the U-shaped fastener body cavity 1070 so as to form a wear surface 1114 against which the body B of the fastener F is permitted to rub. The end member 1108 is coupled to the end of the guide structures 1012 a and 1012 b opposite the end to which the guide port 1100 is coupled. The end member 1108 is configured to abut the ends of the arcuate protrusions 1060 a and 1060 b so as to prevent the guide structures 1012 a and 1012 b from moving upwardly out of the top of the magazine housing 1010 .
[0117] In FIGS. 24 and 25 , the coupling bracket 1014 is shown to have a pair of threaded bushings 1200 and a bracket structure 1202 having a pair of mounting flanges 1204 and a U-shaped body portion 1206 that is coupled to one of the mounting flanges 1204 at each of its opposite ends. Each of the threaded bushings 1200 is coupled to one of the mounting flanges 1204 . The mounting flanges 1204 abut the side of the follower housing portion 1024 and threaded fasteners 1210 ( FIG. 2 ) are employed to engage the threaded bushings 1200 to fixedly but removably couple the coupling bracket 1014 to the magazine housing 1010 .
[0118] The U-shaped body portion 1206 includes a base 1220 and a plurality of legs 1222 , with each of the legs 1222 coupling a side of the base 1220 to an associated one of the mounting flanges 1204 . The base 1220 includes a slotted pin aperture 1230 that includes a circular portion 1232 , a slotted portion 1234 that is spaced apart from the circular portion 1232 , and a necked-down slotted portion 1236 having a width that is smaller than that of the slotted portion 1234 and which interconnects the circular and slotted portions 1232 and 1234 . The circular portion 1232 is sized to receive the head portion 322 of the clamp pin 300 , the slotted portion 1234 is sized to slidingly receive the first body section 324 of the clamp pin 300 , and the necked-down slotted portion 1236 is sized to receive the second body section 326 of the clamp pin 300 but not the first body section 324 . With specific reference to FIG. 25 , the back side of the base 1220 is illustrated in pertinent detail. The end of the slotted portion 1234 is shown to include a conical detent 1238 which is configured to confront the frusto-conical abutting face 330 of the head portion 322 of the clamp pin 300 .
[0119] With reference to FIGS. 19, 20 and 27 through 32 , the follower structure 1002 is illustrated to have a follower body 1300 , a front guide tab 1302 , a lock-out dog 1304 , a loading cam 1306 , a follower guide 1308 and an actuating lever 1310 . The follower body 1300 is generally U-shaped, having a base 1320 and a pair of follower legs 1322 a and 1322 b . The lock-out dog 1304 extends upwardly from the base 1320 in a direction opposite that of the follower legs 1322 a and 1322 b . The front guide tab 1302 is also coupled to the base 1320 but extends upwardly and forwardly therefrom in the same plane as the base 1320 . Accordingly, when the follower structure 1002 is installed to the magazine housing 1010 , the front guide tab 1302 extends forwardly from the follower housing portion 1024 , past the pair of guide housing portions 1026 and into the fastener body portion 1028 where the U-shaped tip portion 1330 of the front guide tab 1302 supports the body B of the fasteners F.
[0120] The loading cam 1306 is formed into follower leg 1322 a and includes a first loading cam portion 1350 , a second loading cam portion 1352 and an unloading cam portion 1354 . The first loading cam portion 1350 is a tapered ramp that extends outwardly and upwardly from the distal end of the follower leg 1322 a . The second loading cam portion 1352 includes an oval follower capturing portion 1360 , a downwardly and forwardly extending intermediate portion 1362 and a forwardly and upwardly extending catch portion 1364 and a catch aperture 1368 that is formed at the lower-most portion of the catch portion 1364 . The follower capturing portion 1360 and the intermediate portion 1362 are formed into a first side of the follower leg 1322 a at a first depth, and the catch portion 1364 is formed into the first side of the follower leg 1322 a at a second depth that is greater than the first depth. The unloading cam portion 1354 is a generally flat portion of the front surface 1370 of the follower leg 1322 a.
[0121] The follower guide 1308 is formed onto the outside surface of follower leg 1322 b . The follower guide 1308 includes a V-shaped flange 1380 , an end member 1382 and a connector portion 1384 that couples the V-shaped flange 1380 and the end member 1382 . The connector portion 1384 is configured to fit into the slot 1042 in the follower housing portion 1024 such that the V-shaped flange 1380 and the end member 1382 confront the rear inside surface 1044 and the rear outside surface 1388 , respectively, of the follower housing portion 1024 .
[0122] The actuating lever 1310 extends outwardly from the end member 1382 and thereafter bends inwardly toward the follower legs 1322 a and 1322 b . The distal end of the actuating lever 1310 forms an engagement surface 1390 that is configured for receiving an input from the tool operator's thumb. A protrusion 1392 that is configured to contact the contact surface 1036 in the fastener head portion 1022 is also formed onto the actuating lever 1310 .
[0123] With reference to FIGS. 19, 20 , 29 , 30 and 33 , the follower spring 1004 is illustrated to include a spring hook 1400 , a coiled, flat band spring 1402 , a cylindrically-shaped spring roller body 1404 and a spring roller pin 1406 . The spring roller pin 1406 extends through and rotatably supports the spring roller body 1404 . The band spring 1402 is a type of torsion spring, being coupled to and wound around the spring roller body 1404 . The free end of the band spring 1402 is coupled to the spring hook 1400 . Each end of the spring roller pin 1406 is set into a generally U-shaped spring roller slot 1410 that is formed into each inside surface of the follower legs 1322 a and 1322 b to couple the follower spring 1004 to the follower structure 1002 .
[0124] When the follower structure 1002 is disposed within the follower housing portion 1024 , the band spring 1402 is unwound to permit the C-shaped spring hook 1400 to be engaged to the side of the follower housing portion 1024 opposite the side in which the L-shaped pin aperture 1050 is formed. The torsion exerted by the band spring 1402 is converted to a force that is exerted through the spring roller pin 1406 to the follower structure 1002 , thereby biasing the follower structure 1002 in an upward direction toward the spring hook 1400 .
[0125] In the particular embodiment illustrated in FIGS. 1, 19 and 35 through 45 , the magazine endcap assembly 1006 includes a molded end cap structure 1600 , a crush tube 1602 , a pivot structure 1604 , a cam follower 1606 , a cam follower spring 1608 and a thrust member 1610 . The end cap structure 1600 is configured to mate against the bottom of the magazine housing 1010 to close off the follower housing portion 1024 and the fastener body portion 1028 .
[0126] The end cap structure 1600 includes a bushing trunnion 1620 for receiving the crush tube 1602 , a fastener trunnion 1622 for receiving a fastener 1623 a ( FIG. 1 ) that couples the nose 1623 b of the end cap structure 1600 to the fastener body portion 1028 and a pair of pivot trunnions 1624 for receiving the pivot structure 1604 , which is illustrated to be a threaded fastener 1626 that is secured to the end cap structure 1600 via a threaded nut 1628 in the example provided. The crush tube 1602 , which is retained by the bushing trunnion 1620 , prevents the end cap structure 1600 form being overstressed as well as the follower housing portion 1024 from being deformed as a result of the clamping force that is exerted by the threaded fastener 1630 ( FIG. 1 ) that couples the end cap structure 1600 to the follower housing portion 1024 .
[0127] The end cap structure 1600 also includes a follower directing wall 1640 , a thrust flange 1642 and a spring flange 1644 . The follower directing wall 1640 extends upwardly from the base 1646 of the end cap structure 1600 and includes a ramped portion 1650 , which tapers outwardly and downwardly from the top end 1652 of the follower directing wall 1640 , and a generally flat portion 1654 that interconnects the ramped portion 1650 to the base 1646 of the end cap structure 1600 . The spring flange 1644 is located proximate one of the pivot trunnions 1624 , extending upwardly from the base 1646 of the end cap structure 1600 behind one of the pivot trunnions 1624 . The thrust flange 1642 is located between the spring flange 1644 and the follower directing wall 1640 and includes a first U-shaped aperture 1660 that is configured to receive the pivot structure 1604 and a second U-shaped aperture 1662 that is configured to receive the hollow thrust member 1610 .
[0128] In the particular embodiment illustrated, the cam follower 1606 includes a lever 1670 and a follower hook 1672 . The lever 1670 includes a slotted pivot aperture 1680 that is sized to receive and rotate as well as pivot in a lateral (side-to-side) direction on a portion of the pivot structure 1604 . The lever 1670 extends beyond the slotted pivot aperture 1680 to form a spring follower hook 1672 that can be employed during the assembly of the magazine endcap assembly 1006 . The follower hook 1672 includes a cylindrical body portion 1690 that is coupled to the distal end of the lever 1670 and a leg member 1692 that is coupled to the outer end of the body portion 1690 and which extends downwardly from the body portion 1690 generally parallel to the lever 1670 . The outside face 1694 of the leg member 1692 is heavily chamfered such that the leg member 1692 terminates at a rounded tip portion 1696 . The intersection between the body portion 1690 and the leg member 1692 is undercut by a radius 1698 .
[0129] The cam follower spring 1608 is illustrated to be a combination compression and torsion spring having a spring body 1700 that wraps around a portion of the pivot structure 1604 , a bent end 1702 for contacting the front face of the lever 1670 and a straight end 1704 for contacting the spring flange 1644 . The cam follower spring 1608 is operable for exerting a rotational biasing force onto the cam follower 1606 which biases the cam follower 1606 toward the rear of the tool 10 . The cam follower spring 1608 is also operable for exerting a lateral force onto the cam follower 1606 which biases the cam follower 1606 toward the thrust member 1610 .
[0130] The pivot structure 1604 is positioned through the pivot trunnion 1624 that is adjacent the spring flange 1644 . The cam follower spring 1608 is positioned over a portion of the pivot structure 1604 such that the straight end 1704 is in contact with the spring flange 1644 . The cam follower 1606 is positioned into the end cap structure 1600 such that the lever 1670 will contact the thrust member 1610 and the follower hook 1672 will be proximate the follower directing wall 1640 . The spring follower hook 1672 of the cam follower 1606 is employed to lift the bent end 1702 of the cam follower spring 1608 onto the lever 1670 . The pivot structure 1604 is then pushed through the slotted pivot aperture 1680 . The hollow thrust member 1610 , which is a washer in the embodiment illustrated, is positioned in the second U-shaped aperture 1662 in the thrust flange 1642 and the pivot structure 1604 is pushed entirely through the end cap structure 1600 and secured in place with the threaded nut 1628 .
[0131] With additional reference to FIGS. 27, 31 and 32 , when fasteners F are to be loaded into the magazine assembly 20 , the tool operator presses the engagement surface 1390 of the actuating lever 1310 to move the follower structure 1002 downward toward the end cap structure 1600 . The ramped portion 1650 of the follower directing wall 1640 directs the follower leg 1322 a of the follower structure 1002 toward the cam follower 1606 and the flat portion 1654 of the follower directing wall 1640 ensures that proper contact is established and maintained between the loading cam 1306 and the cam follower 1606 .
[0132] When the first loading cam portion 1350 of the loading cam 1306 contacts the leg member 1692 of the follower hook 1672 on the cam follower 1606 , the ramp of the first loading cam portion 1350 pushes the follower hook 1672 in a side-to-side motion along the axis of the pivot structure 1604 in the direction of Arrow R ( FIG. 43 ), permitting the leg member 1692 to travel over the first loading cam portion 1350 and into the oval follower capturing portion 1360 of the second loading cam portion 1352 of the loading cam 1306 . With the leg member 1692 being positioned in the oval follower capturing portion 1360 , the follower structure 1002 cannot be moved further down the magazine housing 1010 . When pressure on the engagement surface 1390 of the actuating lever 1310 is released, the force generated by the follower spring 1004 is employed to lift the follower structure 1002 within the magazine housing 1010 so as to simultaneously cause the cam follower 1606 to pivot about the axis of the pivot structure 1604 , thereby permitting the leg member 1692 to travel through the intermediate portion 1362 and into the catch portion 1364 of the second loading cam portion 1352 of the loading cam 1306 . When the leg member 1692 is positioned in the catch portion 1364 of the loading cam 1306 , the leg member 1692 extends through the catch aperture 1368 and around the follower leg 1322 a of the follower structure 1002 as illustrated in FIG. 32 a , thereby securely coupling the cam follower 1606 to the follower structure 1002 and inhibiting upward travel of the follower structure 1002 within the magazine housing 1010 . In this condition, fasteners F may be readily loaded into the magazine assembly 20 .
[0133] If the magazine assembly 20 is not already coupled to the fastening tool portion 30 , this operation is performed next. This is accomplished by positioning the top end of the magazine assembly 20 relative to the nose assembly 40 such that the holes in the guide ports 1100 are proximate an associated one of the magazine guide posts 66 , the stop member 134 on the trigger lever 54 is positioned directly above the first portion 1052 of the L-shaped pin aperture 1050 , and the head portion 322 of the clamp pin 300 is engaged to the circular portion 1232 of the slotted pin aperture 1230 in the base 1220 of the bracket structure 1202 . The actuating cam 306 is then pushed toward the clamp boss 252 to compress the compression spring 302 and extend the clamp pin 300 in an outward direction so that the second body section 326 of the clamp pin 300 extends through the slotted pin aperture 1230 . With the clamp pin 300 in this condition, the magazine assembly 20 is slid upwardly until the clamp pin 300 is fully positioned into the slotted portion 1234 of the slotted pin aperture 1230 . Simultaneously, the guide ports 1100 are slid further onto the magazine guide posts 66 so that the top of the magazine assembly 20 cannot pivot relative to the nose assembly 40 and the stop member 134 on the trigger lever 54 is disposed in the second portion 1054 of the L-shaped pin aperture 1050 .
[0134] Thereafter, the tool operator releases the actuating cam 306 , causing the compression spring 302 to retract the clamp pin 300 somewhat so that the first body section 324 of the clamp pin 300 is disposed within the slotted portion 1234 of the slotted pin aperture 1230 . In this condition, the parallel flats 328 that are formed onto the first body section 324 abut the parallel sides of the slotted portion 1234 of the slotted pin aperture 1230 , thereby permitting the magazine assembly 20 to be slid along an axis defined by the magazine guide posts 66 and the slotted portion 1234 of the slotted pin aperture 1230 . The magazine assembly 20 is pushed upwardly into contact with the magazine flange 64 that is formed into the nose structure 50 . The actuating cam 306 is then pivoted to place the leg portion 352 in contact with the flat contact surface 344 . More specifically, the frusto-conical abutting face 330 of the head portion 322 of the clamp pin 300 engages the conical detent 1238 that is formed into the end of the slotted portion 1234 to both locate the magazine assembly 20 relative to the tool portion 30 as well as to mechanically lock the clamp pin 300 to the coupling bracket 1014 .
[0135] In this condition, the compression spring 302 exerts a clamping force that is transmitted through the clamp pin 300 to fixedly but removably couple the coupling bracket 1014 to the clamp boss 252 . The magazine stabilizing tabs 62 extend downwardly from the magazine flange 64 and abut the opposite sides of the fastener body portion 1028 of the magazine housing 1010 to inhibit excessive rotation of the magazine assembly 20 relative to the nose assembly 40 .
[0136] With the magazine assembly 20 attached, the fasteners F are fed into the magazine assembly 20 such that the body B of the fasteners F enter the follower cavity 1040 via the slot 1042 . Typically, the fasteners F are collated (usually at an angle of 20° or 31°) in “sticks”, which permits the magazine assembly 20 to be loaded relatively rapidly.
[0137] The follower structure 1002 is released from the cam follower 1606 by pressing downwardly on the engagement surface 1390 of the actuating lever 1310 . The body portion 1690 of the follower hook 1672 rides on the upper surface of the forwardly and upwardly extending catch portion 1364 , causing the cam follower 1606 to rotate forwardly. The simultaneous downward movement of the follower structure 1002 and the forward rotation of the cam follower 1606 continues until the leg member 1692 slips out of the catch portion 1364 and the body portion 1690 of the follower hook 1672 slides onto the unloading cam portion 1354 of the loading cam 1306 . As the leg member 1692 of the follower hook 1672 is not contacting the side of the leg 1322 a of the follower structure 1002 , the follower spring 1004 exerts a force against the lever 1670 that pushes the follower hook 1672 in a side-to-side motion so that the lever 1670 abuts the thrust member 1610 . With the body 1690 of the follower hook 1672 engaged against the unloading cam portion 1354 of the loading cam 1306 , the body 1690 of the follower hook 1672 prevents the cam follower 1606 from engaging the follower structure 1002 and the upward motion of the follower structure 1002 is controlled by the follower spring 1004 . The upward movement of the follower structure 1002 brings the tip portion 1330 of the front guide tab 1302 into contact with the bottom-most fastener F in the magazine assembly 20 which urges the fasteners F upwardly and into the nose assembly 40 . The force exerted by the follower structure 1002 onto the fasteners F, along with the configuration of the fastener head portion 1022 , ensures that fasteners F will not slip rearwardly out of the magazine assembly 20 during the operation of the tool 10 .
[0138] As discussed above, the tool operator must push the contact trip 52 against the workpiece to cause the trigger lever 54 to push the secondary trigger 128 in to contact with the trigger valve 130 to permit the state of the trigger valve 130 to be changed. With the magazine assembly 20 fully engaged against the magazine flange 64 , the stop member 134 on the trigger lever 54 is free to move in a direction parallel to the longitudinal axis of the tool 10 (i.e., rearwardly-forwardly) within the second portion 1054 of the L-shaped pin aperture 1050 .
[0139] In the event of a “jam” condition wherein fasteners F have not fed properly through the nose assembly 40 , the tool operator need only rotate the actuating cam 306 such that its base portion 350 is abutted against the flat contact surface 344 to release the clamping force that is exerted through the clamp pin 300 . The magazine assembly 20 may then be slid downwardly from the magazine flange 64 to permit the tool operator to service the nose assembly 40 . The magazine assembly 20 , however, is constrained by the magazine guide posts 66 and the clamp pin 300 so that it can only move in a predetermined linear direction. The predetermined linear direction is cooperatively defined by the magazine guide posts 66 , which remain engaged in the holes 1800 in the guide ports 1100 , and the first body section 324 of the clamp pin 300 , which remains engaged in the slotted portion 1234 of the slotted pin aperture 1230 . Downward movement of the magazine assembly 20 is checked when the first body section 324 of the clamp pin 300 contacts the necked-down slotted portion 1236 of the slotted pin aperture 1230 . Accordingly, the nose assembly 40 may be serviced without completely removing the magazine assembly 20 from the magazine flange 64 . Furthermore, when the magazine assembly 20 is moved downwardly into this condition, the stop member 134 is moved out of the second portion 1054 of the L-shaped pin aperture 1050 and into the first portion 1052 of the L-shaped pin aperture 1050 . With the stop member 134 located in this manner, rearward motion of the contact trip 52 relative to the nose body 60 is limited such that the stop member 134 contacts the rearward edge 1820 of the first portion 1052 of the L-shaped pin aperture 1050 , thereby preventing the trigger lever 54 from pushing the secondary trigger 128 sufficiently rearward so that the state of the trigger valve 130 cannot be changed (i.e., actuated). Accordingly, the stop member 134 and the L-shaped pin aperture 1050 cooperate to selectively prevent the trigger valve 130 from being actuated depending upon the position of the magazine assembly 20 relative to the magazine flange 64 .
[0140] Those skilled in the art will understand from this disclosure that as fasteners F are dispensed from the tool 10 , the follower spring 1004 will force the follower structure 1002 in an upwardly direction so as to continue to feed fasteners F into the nose body 60 . When the magazine assembly 20 is empty of fasteners F, the follower structure 1002 will be raised within the magazine housing 1010 to a point wherein the lock-out dog 1304 extends through the lock-out dog aperture 90 that is formed into the magazine flange 64 so that it inhibits sufficient rearward motion of the contact trip 52 so as to prevent the trigger lever 54 from changing the state of the trigger valve 130 . Accordingly, the lock-out dog 1304 inhibits the tool 10 from cycling when the magazine assembly 20 is empty of fasteners F and coupled to the magazine flange 64 .
[0141] In an alternate embodiment of the present invention illustrated in FIGS. 46 and 47 , the nose assembly 40 includes a pivoting lock-out tab 2000 that is rotatably coupled to the nose structure 50 and pivotable between a first position, which is illustrated in FIG. 47 , that permits the contact trip 52 to move rearwardly a sufficient amount that permits the trigger lever 54 to change the state of the trigger valve 130 , and a second position, which is shown in FIG. 46 , that inhibits rearward motion of the contact trip 52 by an amount wherein the trigger lever 54 cannot change the state of the trigger valve 130 . As illustrated in FIG. 47 , when the magazine assembly 20 abuts the magazine flange 64 , the top surface 2010 of the magazine housing 1010 contacts the lock-out tab 2000 and rotates it into the first position. When the magazine assembly 20 is not abutted against the magazine flange 64 as illustrated in FIG. 46 , however, the lock-out tab 2000 is rotated by a torsion spring (not specifically shown) into the second position to prevent the tool 10 from being cycled.
[0142] Those skilled in the art will understand from this disclosure that the configuration of the slotted pin aperture and the clamp pin may be somewhat different from that which is shown in FIGS. 9 b and 24 . For example, the clamp pin and the slotted pin aperture may be formed as is illustrated in FIGS. 48 and 49 , respectively. In this embodiment, the clamp pin 300 ′ is substantially identical to the clamp pin 300 except for the omission of the parallel flats 328 from the first body section 324 ′.
[0143] The configuration of the slotted pin aperture 1230 ′, however, is substantially different from the configuration of the slotted pin aperture 1230 . In this regard, the slotted pin aperture 1230 ′ includes a circular portion 1232 ′, which is sized to receive the head 322 ′ of the clamp pin 300 ′ therethrough, and a slotted portion 1234 ′, which has a body portion 1234 a with a first end 1234 b and a second end 1234 c . The first end 1234 b interconnects the body portion 1234 a to the circular portion 1232 ′ in a dog-legged manner. In this regard, the first end 1234 b defines a protrusion 1234 d that necessitates that the coupling bracket 1014 ′ and the clamp pin 300 ′ be moved laterally relative to one another to permit the clamp pin 300 ′ to move around the protrusion 1234 d and into the circular portion 1232 ′. The first end 1234 b and the protrusion 1234 d may be sized so as to permit the first body section 324 ′ of clamp pin 300 ′ to pass around the dog-leg and into the circular portion 1232 ′, or, as is presently preferred may be sized to allow only permit the second body section 326 ′ of the clamp pin 300 ′ to pass around the dog-leg and into the circular portion 1232 ′. The second end 1234 c of the body portion 1234 a is similar in configuration to the end of the slotted portion 1234 , in that it includes a conical detent 1238 . The second end 1234 c , however, defines one or more protrusions 1234 e which are relatively narrower than the body portion 1234 a so as to admit therethrough only the second body section 326 ′ of the clamp pin 300 ′.
[0144] This alternate construction of the clamp pin 300 ′ and the coupling bracket 1014 ′ is advantageous in that it simplifies the construction of the clamp pin 300 ′ (relative to the clamp pin 300 ), and renders the connection between the clamp pin 300 ′ and the coupling bracket 1014 ′ more secure.
[0145] While the invention has been described in the specification and illustrated in the drawings with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined in the claims. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling within the foregoing description and the appended claims.
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A pneumatic fastening tool assembly that employs an engine having a sliding sleeve arrangement to control the supply of air to and exhaust from the pneumatic engine. The sliding sleeve arrangement eliminates the need for a conventional main valve and thereby reduces the overall weight and length of the pneumatic fastening tool relative to those tools that employ a conventional engine configuration.
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BACKGROUND OF THE INVENTION
This invention relates to an image pickup method using a CCD (charge-coupled device) type solid state image pickup device as an image input device such as a television camera.
FIG. 1 is a plan view roughly showing a conventional CCD-type solid state image pickup device. In FIG. 1, an input 1 supplies vertical transfer clock signals, a horizontal transfer clock is supplied at an input 2, and an image signal obtained by the image pickup operation is produced at an output 3. An array of photosensitive elements 4 corresponding to image pixels supplies signals to corresponding vertical shift registers 5, which in turn supply signals to a horizontal shift register 6 in response to read-out pulses on a line 7.
In the operation of a raster scanning system of the type shown in FIG. 1 in which the image signals are read from respective photosensitive elements 4 using read-out pulses 7 and transferred into the vertical shift register 5, and then transferred from the vertical shift register to the horizontal shift register 6 using vertical transfer clock pulses 1 and the data is read as an image signal output 3 from the horizontal shift register 6 using horizontal transfer clock pulses from the input 2, reading of an image requires a relatively long interval, such as 1/30th second. This requires a long image-exposure time, thereby hindering high-speed image pickup if an interlace system employing the NTSC system is used.
If the image signal received by the vertical shift register 5 is transferred to the horizontal shift register 6 using an especially high-speed vertical transfer clock by modifying the raster scanning system to a nonraster scanning system, and if the image signal is read out of the horizontal shift register 6 in a short time using a higher-speed horizontal transfer clock and discarded (the scanning for such discard is hereinafter referred to as the nonraster scan), and if the image signals which are formed by the photodetection of the respective photosensors in that short time are then reread and taken as an output, the image exposure time can be shortened and high-speed image pickup can be performed so that an unblurred image signal can be obtained even if the object is moving.
FIG. 2a is a schematic cross-sectional view of a portion M of a CCD structure in which the corresponding portions of one photosensitive element 4 and a vertical shift register 5 of FIG. 1 are included. In other words, FIG. 2a shows an MOS-type CCD pixel structure having an overflow drain structure for eliminating excessive signal charges which may be the cause of blooming and/or smear.
FIG. 2b illustrates schematically the distribution of energy levels at a time t 1 in the structure of FIG. 2a. FIG. 2c illustrates the distribution of energy levels at another time t 2 in the same structure.
In FIG. 2a, the reference numeral 11 denotes a one-pixel image area. FIGS. 2a and 2b show channel stops 12, a V-CCD 13 corresponding to a vertical shift register 5 in FIG. 1, a read-out gate 14, a photosensitive area 15, an overflow control gate 16, and an overflow drain 17. In FIG. 2a, the structure includes an Al photoshield 18, a transparent electrode 19, an insulating film 20, and an electrode 21. FIGS. 2b and 2c illustrate signal charges 22 and overflow charges 23.
In the symbol representation of P + , N + and P - , + and - indicate that the impurity densities are higher or lower, respectively. Reference character P denotes a P-type semiconductor and N denotes an N-type semiconductor, as usual.
FIG. 3 is a timing chart for the vertical transfer clock signals at the input 1 of FIG. 1 and the read-out pulses 7 applied to the device shown in FIG. 2a.
The operation of the system will now be described with reference to FIGS. 2a, 2b, 2c and 3.
In FIG. 2a, a bias potential V SG is applied to the transparent electrode 19. Vertical transfer clock pulses 1 and read-out pulses 7, shown in FIG. 3, are applied to the electrode 21. Synthesis of a clock signal 1 and a read-out pulse 7 will result in a three-value (V H , V M and V L ) signal as shown in FIG. 3.
A distribution of electron energy levels during storage of signal charges in the device of FIG. 2a, for example, at a time t 1 (FIG. 3) is shown in FIG. 2b. At the time t 1 , namely, when no read-out pulse 7 is applied, the transparent electrode 19 is impressed with a bias voltage V SG , and the energy level is lowered by a potential difference V SG , corresponding to the bias voltage V SG between the photosensitive section 15 and overflow drain 17. As a result, a well for storage of electric charges is formed.
If a vertical transfer clock pulse 1 is applied to the electrode 21, the energy levels will be lowered by potential differences V M ' and V L ' corresponding to the potential levels V M and V L of the transfer clock pulse 1 between the overflow drain 17 and the read-out gate 14, and thus a well for storage of electric charges will be formed.
As is clear from FIG. 3, the following relationship holds:
V.sub.M '>V.sub.L '
In FIG. 2b, the relationship P A >P B holds where P B is the magnitude of a potential barrier produced at the junction between the photosensitive section 15 and the overflow control gate 16 of the device and V SG '-V M '=P A .
If light enters the solid state image pickup device, electrons are optically excited where the layer 20 is not covered with the Al photoshield 18, and they are stored as electric charges in the electron well in the photosensitive section 15.
The quantity of electric charge stored in the well is limited by the potential barrier P B , and any electric charges 23 overflowing the barrier P B flow out via the overflow control gate 16 to the overflow drain 17 and are then discharged from the image pickup device.
The potential barrier P B is usually selected so that the total charge on the photosensitive section 15 does not exceed the charge which can be handled by the V-CCD 13. The magnitude of the barrier is determined by the difference in the impurity densities of the semiconductors constituting the photosensitive section 15 and the overflow control gate 16.
Application of a read-out pulse at a time t 2 as shown in FIG. 3 will be described with reference to FIG. 2c. If a read-out pulse 7 is applied to the electrode 21 of FIG. 1, the energy level will be lowered by a level difference V H ' corresponding to the potential V H of the read-out pulse 7 between the overflow drain 17 and the read-out gate 14. If V H '-V M '=P C , the energy level will be further lowered by a level corresponding to a potential barrier P C compared to the level shown in FIG. 2b.
At this time, the following condition should hold:
V.sub.H '≧V.sub.SG '
Thus, the energy level of read-out gate 14 is lowered compared to the photosensitive section 15 and the signal charges 22 flow via the read-out gate 14 into the V-CCD 13 and are read.
It is to be noted that a channel stop 12 is provided between the V-CCD 13 and the adjacent pixel overflow drain 17 such that no electric charges 22 on the V-CCD 13 leak out.
At a time t 3 when a vertical transfer clock pulse 1 is applied, the energy level difference between the read-out gate 14 and the photosensitive section 15 will be further increased because:
P.sub.A '>P.sub.A if V.sub.SG '-V.sub.L '=P.sub.A '
At present, the electric charge transfer system for one known CCD includes a four-phase clock system. Herein, as an example, the structure of a CCD which employs a three-phase clock system is shown in FIG. 4a, while fluctuations in the electron energy level of the CCD at the respective timings by three-phase transfer clock pulses 25a, 25b and 25c, such as are shown in FIG. 5, are illustrated in FIG. 4b.
FIG. 4a shows a V-CCD 13 corresponding to the vertical shift register 5 of FIG. 1 having electrodes 21. The V-CCD 13 of FIG. 4a receives the inflow signal charges shown in FIG. 2c.
In FIGS. 4a, 4b and 5, when the time shifts from Ta to Tc, the clock pulse 25b changes from low L to high H while the clock pulse 25a changes from high H to low L. This shifts the charge well by a distance corresponding to one electrode 21 to the right as viewed in FIG. 4a, moving the signal charges 22 in the well by a distance corresponding to one electrode 21. Such shifting of electric charges 22 is repeated as shown in FIG. 4b until the time Tg to thereby transfer signal charges 22 for one pixel.
In the foregoing, description has been made with respect to FIG. 1 as follows: if the image signal taken into vertical shift register 5 is transferred to horizontal shift register 6 in a nonraster scanning system by modifying a raster scanning system using an especially high-speed vertical transfer clock, and if the image signal is read out of the horizontal shift register 6 in a short time using a much higher-speed horizontal transfer clock and discarded, and if the image signal formed by the photodetection of the respective photosensors in that short time is then reread out and taken as an output, then a short exposure time will be obtained to permit high-speed image pickup.
If the quantity of electric charges read out of the horizontal shift register 6 and discarded as useless is large and greater than the discharge capacity of the horizontal shift register 6, the charges may remain in the horizontal shift register 6 for a time without being discharged. As a result, the remaining charges are added to the next electric charges received as an image signal is read out next, such as the electric charges constituting the edge portion of the image, to thereby distort part of the received image and deteriorate the image quality.
SUMMARY OF THE INVENTION
The object of this invention is to solve the above problems and eliminate the retention of useless electric charges in the horizontal shift register by improving the capacity of the register to discharge useless charges, and to prevent the occurrence of distortion in the image with a method using a conventional CCD-type solid state image pickup device which is capable of performing image pickup at high speed. In othe words, the object of this invention is to provide an image pickup method in which distortion in the image does not occur using a CCD-type solid state image pickup device.
These and other objects of the invention are attained by transferring charges from a photosensitive element to a vertical CCD register in accordance with transfer clock signals, and reducing the potential barrier in the vertical CCD register in the clock phase which the transfer clock assumes when charges are discharged from the horizontal CCD register so that the charges in the horizontal CCD register flow back to the photosensitive element through the vertical CCD register and are also discharged from the overflow drain of the photosensitive element without encountering a potential barrier.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the invention will be apparent from a reading of the following description in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic block diagram showing a conventional CCD-type solid state image pickup device;
FIG. 2a is a cross-sectional view of an MOS-type CCD pixel structure and FIGS. 2b and 2c illustrating the distribution of energy levels therein;
FIG. 3 is a timing chart for the vertical transfer clock and read-out pulses applied to the device shown in FIG. 2a;
FIG. 4a is a schematic view showing a CCD structure which employs a three-phase clock drive system and FIG. 4b illustrates fluctuations in the electron energy levels thereof;
FIG. 5 is a timing chart for the transfer clock pulses applied to the CCD shown in FIG. 4;
FIG. 6a is a schematic plan view illustrating a representative CCD arrangement in accordance with this invention and FIGS. 6b and 6c show the operation thereof;
FIG. 7 is a schematic block diagram showing a representative embodiment of a CCD-type device arranged according to this invention;
FIG. 8 is a timing chart for the signals at the selected locations in the circuit of FIG. 7; and
FIGS. 9a and 9b illustrate the operational mode of this invention.
DESCRIPTION OF PREFERRED EMBODIMENT
The invention will now be described with reference to FIGS. 6a, 6b and 6c.
FIG. 6a illustrates a representative arrangement for solving the problems of the prior art in accordance with this invention and FIGS. 6b and 6c show the operation thereof. FIG. 6a is a schematic plan view of a regular CCD-type solid state image pickup device used in this invention corresponding to the plan view obtained when viewed from above in FIG. 1. Reference numeral 5 denotes a V-CCD corresponding to the V-CCD 13 in FIG. 1 including a photosensitive section 15, an overflow drain 17, a horizontal shift register 6 (H-CCD), a series of electrodes 21 positioned over the V-CCD 5, and three-phase transfer clocks 25a, 25b and 25c.
FIG. 6b is a timing chart for the three-phase transfer clocks 25a, 25b and 25c when this invention is not being used, and FIG. 6c is a timing chart for three-phase transfer clocks 25a, 25B and 25c when the invention is used, the interval 7 being the time during which a read-out pulse is applied.
As is clear from a comparison between FIGS. 6b and 6c, the corresponding three-phase transfer clocks have the same timing phase except for the transfer clocks 25b and 25B. Specifically, when the invention is not used, the clock shown in FIG 6b is used as the three-phase transfer clock while, when this invention is used, the clock shown in FIG. 6c is used, which provides the method for solving the prior art problems.
The operation will now be described with reference to FIGS. 6a, 6b and 6c.
When a read-out pulse 7 is applied and conventional vertical transfer clock signals 25a, 25b and 25c (FIG. 6b) are applied to the electrodes 21, a potential barrier is formed at the boundary between the V-CCD 5 and the H-CCD 6 shown by a broken-line area S at the time in which clock signal 25b is applied, so that useless electric charges to be discharged from the H-CCD 6 are prevented from flowing reversely to the V-CCD 5.
When this invention is carried out by applying vertical transfer clocks 25a, 25B and 25c as shown in FIG. 6c to the electrodes 21, the potential barrier present at the boundary represented by the broken-line area S is eliminated by vertical transfer clock 25B during the time in which the clock signal 25B is applied, i.e., at the point in time when a large amount of useless discarded electric charges, read out of the photosensitive section 15 and transferred via the V-CCD 5 to the H-CCD 6 at high speed, remain on the H-CCD 6. Thus, the useless charges on the H-CCD 6 may flow reversely through the V-CCD 5 to the nearest photosensitive section 15 and hence discharge to the overflow drain 17. The charges do not flow reversely to more remote photosensitive section because a potential barrier is formed midway in the passageway to the more remote photosensitive section.
In this way, the useless electric charges on the H-CCD 6 are efficiently discarded. Thereafter, the potential of transfer clock 25B may be raised to a level as high as the transfer clock 25a (to the extent to which the device is not damaged). Thus, when the lowered energy level of the V-CCD 5 is lowered below that of the overflow control gate 16, the maximum amount of electric charge can be discharged.
By this method, any distortion in the image occurs in only one pixel line comprising the nearest photosensitive section to H-CCD 6. If an image pickup device is used in which that one image line is a dummy, no image distortion will occur.
A Specific arrangement according to this invention will now be described with reference to FIGS. 7 and 8.
FIG. 7 is a schematic block diagram showing a representative embodiment of this invention. In FIG. 7, the embodiment includes a CCD-type solid state image pickup device 30, a driver 31, a transfer signal synthesizer 32, a vertical transfer clock generator 33 for signal discharge, a read-out pulse generator 34 for nonraster scanning, a read-out pulse generator 35 for carrying out this invention, a timer 36 and a standard drive circuit 37.
FIG. 8 is a timing chart showing the signals at selected portions of the circuit of FIG. 7. In FIG. 8, reference numeral 40 denotes a blanking signal from the drive circuit 37 having a V-blanking interval 48, the signal 43 is a horizontal transfer clock from the drive circuit, the signal 44 is an image sweep-out (discharge) signal from the timer 46 with an image sweep-out (discharge) interval 49, the signals 25a, 25B and 25c are the three-phase vertical transfer clock signals from the transfer signal synthesizer 32 having an image sweep-out (discharge) read-out pulse 46 and a read-out pulse 47, and the signal 50 represents the device output.
The operation of the circuit will now be described with reference to FIGS. 7 and 8. The blanking signal 40 is supplied from the standard drive circuit 37 to the timer circuit 36. When the timer circuit 36 senses a V-blanking interval 48 in the blanking signal 40, it supplies a signal indicative of the image sweep-out interval 49 to the transfer signal synthesizer 32, which, during that interval operates so as to block a signal from the standard drive circuit 37 from being transferred and to supply signals from the signal discharge vertical transfer clock generator 33 and the read-out pulse generators 34 and 35.
The timer circuit 36 generates a signal indicative of an interval of A" to cause discharge of the vertical transfer clock generator 33, a signal indicative of an interval of A' to the read-out pulse generator 34, and a signal indicative of an interval of B' to the read-out pulse generator 35 to operate the respective circuits for only those corresponding intervals. During the interval B", all of the vertical transfer clocks 25a, 25B and 25c are stopped, and only the electric charges on the H-CCD 6 are discharged by the horizontal transfer clock 43 from the standard drive circuit 37.
This embodiment has been described with respect to the three-phase V-CCD-type solid state image pickup device. In FIG. 8, reference character A denotes a nonraster scanning interval and B an electric charge discharge interval according to this invention. The interval B' is the one during which the electric charges on the H-CCD 6 flow reversely, as shown by the arrow Y in FIG. 9a, and the interval of B" is the one in which the electric charges on the H-CCD 6 discharge to others, as shown by the arrow K in FIG. 9b.
According to this invention, the efficiency of discharging useless signal electric charges is improved in the H-CCD (horizontal shift register) of a CCD-type solid state image pickup device, thereby solving the conventional problem of distortion of part of the received image which degrades the image quality.
Although the invention has been described herein with reference to specific embodiments, many modifications and variations therein will occur to those skilled in the art. Accordingly, all such variations and modifications are included within the intended scope of the invention.
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In the CCD-type solid state image pickup device described in the specification, a photodetection unit has an overflow drain structure and a vertical CCD register receives electric charges from the photodetection unit and a horizontal CCD register receives charges from the vertical CCD register. Charges are transferred from the vertical CCD register at a higher rate than normal and, to prevent accumulation of charges in the horizontal CCD register, an interval is provided in which unused charges are drained through the vertical CCD register.
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FIELD OF THE INVENTION
The present invention relates to a method of manufacturing a fibre reinforced metal matrix composite article, and the present invention relates in particular to a method of manufacturing a fibre reinforced metal matrix composite rotor, for example a compressor rotor or turbine rotor.
BACKGROUND OF THE INVENTION
In one known method of manufacturing a fibre reinforced metal matrix composite article, as disclosed in European patent No. EP0831154B1, a plurality of metal-coated fibres are placed in an annular groove in a metal ring and a further metal ring is placed on top of the metal-coated fibres. Each of the metal-coated fibres is wound spirally in a plane and the metal-coated fibre spirals are stacked in the annular groove in the metal ring. The metal rings are pressed predominantly axially to consolidate the assembly and to diffusion bond the metal rings and the metal coated fibre spirals together to form an integral structure.
In a further known method of manufacturing a fibre reinforced metal matrix composite article, as disclosed in European patent application No. EP1288324A2, the arrangement described in EP0831154B1 is modified by the inclusion of metal wires in the annular groove in the metal ring with the metal-coated fibres. Each of the metal wires is wound spirally in a plane and the metal wire spirals are stacked in the annular groove in the metal ring with the metal-coated fibre spirals.
In these methods of manufacturing a fibre reinforced metal matrix composite the metal coated fibres, or the metal coated fibres and metal wires, are wound spirally in a plane on a former and the metal coated fibre spirals, or metal coated fibre spirals and metal wire spirals, are temporarily held together with a glue to enable the metal coated fibre spirals, or metal coated fibre spirals and metal wire spirals, to be assembled in the annular groove in the metal ring. The glue is applied locally to the metal-coated fibre spirals, or metal coated fibre spirals and metal wire spirals.
Due to necessary clearances and slight variation in the diameter of the fibres or fibres and wires, the metal coated fibre spirals, or metal coated fibre spirals and metal wire spirals are not perfectly flat, i.e. adjacent metal coated fibres, or metal coated fibres and metal wires, are slightly out of plane. As a result the spirals are not ideally packed during the dry assembly of the spirals in the annular groove in the metal ring and this leaves undesirable excess free space between the metal-coated fibres. The excess free space means that the confronting faces of the metal rings will not abut each other and it is not possible to seal the assembly. It is then necessary to provide a deeper annular groove in the metal ring in order to allow the confronting faces of the metal rings to abut each other. An increase in the depth of the annular groove is undesirable because the further metal ring has to be moved a greater distance to achieve consolidation. Additionally, the excess free space allows the metal coated fibres to move out of position and may even allow some of the metal coated fibres to cross other metal coated fibres and this may results in breaking of the metal coated fibres during processing, essentially creating material defects.
SUMMAARY OF THE INVENTION
Accordingly the present invention seeks to provide a novel method of manufacturing a fibre reinforced metal matrix composite article.
Accordingly the present invention provides a method of manufacturing a fibre reinforced metal matrix composite article, the method comprising the steps of:
(a) forming a first metal component, (b) forming a second metal component, (c) forming at least one fibre preform, the fibre preform comprising at least one fibre, applying a glue to the fibre preform to hold the at least one fibre in position, (d) softening the glue on the at least one fibre preform and simultaneously pressing the at least one fibre preform to increase the packing density of the at least one fibre preform, (e) placing the at least one fibre preform and filler metal between the first metal component and the second metal component, (f) sealing the second metal component to the first metal component, (g) removing the glue from the at least one fibre preform, (h) applying heat and pressure such to consolidate the at least one fibre preform and the filler metal and to diffusion bond the filler metal, the first metal component and the second metal component to form a unitary composite component.
Preferably step (a) comprises forming a circumferentially extending groove in a face of the first metal member, placing at least one circumferentially extending fibre preform and the filler metal in the circumferentially extending groove of the first metal component and placing the second metal component in the groove of the first metal component.
Preferably step (b) comprises forming a projection on the second metal component and step (e) comprises placing the projection of the second metal component in the groove of the first metal component.
Preferably step (a) comprises forming a circumferentially extending groove in a face of the first metal member, placing at least one circumferentially extending fibre preform and the filler metal in the circumferentially extending groove of the first metal component and placing the second metal component in the groove of the first metal component.
Preferably step (d) comprises softening the glue by introducing a solvent into the fibre preform.
Preferably step (d) comprises softening the glue by introducing a small quantity of liquid solvent into the fibre preform.
Alternatively step (d) comprises softening the glue by flowing a liquid solvent, or a vaporised solvent, through the fibre preform.
Alternatively step (d) comprises softening the glue by heating the first and second metal components.
Alternatively step (d) comprises softening the glue by flowing a hot fluid through the fibre preform.
Preferably the at least one fibre is a silicon carbide fibre, a silicon nitride fibre, a boron fibre or an alumina fibre.
Preferably the at least one fibre is a metal coated fibre.
Preferably the at least one metal coated fibre is a titanium coated fibre, a titanium aluminide coated fibre or a titanium alloy coated fibre.
Preferably step (c) comprises winding at least one fibre on a former to form a spiral fibre preform, applying a glue to the spiral fibre preform to hold the at least one fibre in position and removing the spiral fibre preform from the former.
Preferably step (c) comprises winding a plurality of fibres on a former to form a plurality of spiral fibre preforms, applying a glue to each spiral fibre preform to hold each fibre in position and removing each spiral fibre preform from the former.
Preferably the filler metal comprises at least metal wire and the method comprises winding at least one metal wire on a former to form a spiral wire preform, applying a glue to the spiral wire preform to hold the at least one metal wire in position and removing the second spiral wire preform from the former.
Preferably the at least one metal wire is a titanium wire, a titanium aluminide wire or a titanium alloy wire.
Preferably the method includes winding a plurality of metal wires on a former to form a plurality of spiral fibre preforms, applying a glue to each spiral fibre preform to hold each metal wire in position and removing each spiral fibre preform from the former.
The present invention also provides a method of manufacturing a fibre reinforced metal matrix composite article, the method comprising the steps of:
(a) forming a circumferentially and axially extending groove in an face of a first metal component, (b) forming a circumferentially and axially extending projection on an face of a second metal component, (c) winding at least one fibre on a former to form a spiral fibre preform, applying a glue to the spiral fibre preform to hold the at least one fibre in position and removing the spiral fibre preform from the former, (d) arranging the at least one spiral fibre preform and filler metal in the circumferentially and axially extending groove in the first metal component, (e) placing the circumferentially and axially extending projection on the second metal component in the circumferentially and axially extending groove in the first metal component, (f) softening the glue on the at least one spiral fibre preform and simultaneously pressing the circumferentially and axially extending projection on the second metal component into the circumferentially and axially extending groove in the first metal component to increase the packing density of the at least one spiral fibre preform, (g) sealing the second metal component to the first metal component, (h) removing the glue from the at least one spiral fibre preform, (i) applying heat and pressure such that the circumferentially and axially extending projection moves into the circumferentially and axially extending groove to consolidate the at least one spiral preform and the filler metal and to diffusion bond the filler metal, the first metal component and the second metal component to form a unitary composite component.
Preferably step (f) comprises introducing a solvent into the circumferentially and axially extending groove in the first metal component to soften the glue.
Preferably step (f) comprises introducing a small quantity of liquid solvent into the circumferentially and axially extending groove in the first metal component.
Alternatively step (f) comprises flowing a liquid solvent, or a vaporised solvent, through the circumferentially and axially extending groove in the first metal component.
Alternatively step (f) comprises heating the first and second metal components to soften the glue.
Alternatively step (f) comprises flowing a hot fluid though the circumferentially and axially extending groove in the first metal component to soften the glue.
Preferably the at least one fibre is a silicon carbide fibre, a silicon nitride fibre, a boron fibre or an alumina fibre.
Preferably the at least one fibre is a metal coated fibre.
Preferably the at least one metal coated fibre is a titanium coated fibre, a titanium aluminide coated fibre or a titanium alloy coated fibre.
Preferably (c) comprises winding a plurality of fibres on a former to form a plurality of spiral fibre preforms, applying a glue to each spiral fibre preform to hold each fibre in position and removing each spiral fibre preform from the former.
Preferably the filler metal comprises at least metal wire and the method comprises winding at least one metal wire on a former to form a spiral wire preform, applying a glue to the spiral wire preform to hold the at least one metal wire in position and removing the second spiral wire preform from the former.
Preferably the at least one metal wire is a titanium wire, a titanium aluminide wire or a titanium alloy wire.
Preferably the method includes winding a plurality of metal wires on a former to form a plurality of spiral fibre preforms, applying a glue to each spiral fibre preform to hold each metal wire in position and removing each spiral fibre preform from the former.
Preferably the first metal component and the second metal component comprise titanium, titanium aluminide or titanium alloy.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully described by way of example with reference to the accompanying drawings in which:
FIG. 1 is a longitudinal, axial, cross-sectional view through a bladed compressor rotor made according to the method of the present invention.
FIG. 2 is a plan view of a fibre preform used in the method of the present invention.
FIG. 3 is a cross-sectional view through the preform shown in FIG. 2 .
FIG. 4 is a longitudinal, axial, cross-sectional view through an assembly of fibre preforms positioned between first and second metal rings.
FIG. 5 is an enlarged cross-sectional view through the fibre preforms shown in FIG. 4 before softening of the glue.
FIG. 6 is an enlarged cross-sectional view through the fibre preforms shown in FIG. 4 after softening of the glue.
FIG. 7 is a longitudinal, axial, cross-sectional view through the assembly of fibre preforms positioned between first and second metal rings after welding together.
FIG. 8 is a longitudinal, axial, cross-sectional view through the assembly of fibre preforms positioned between first and second metal rings after consolidation and bonding to form a unitary composite article.
FIG. 9 is a plan view of a fibre and wire preform used in an alternative method of the present invention.
FIG. 10 is a cross-sectional view through the preform shown in FIG. 9 .
DETAILED DESCRIPTION OF THE INVENTION
A finished ceramic fibre reinforced metal rotor 10 with integral rotor blades is shown in FIG. 1 . The rotor 10 comprises a metal ring 12 , which includes a ring of circumferentially extending reinforcing ceramic fibres 14 , which are embedded in the metal ring 12 . A plurality of solid metal rotor blades 16 are circumferentially spaced on the metal ring 12 and extend radially outwardly from and are integral with the metal ring 12 .
A ceramic fibre reinforced metal rotor 10 is manufactured using a plurality of metal-coated ceramic fibres. Each ceramic fibre 14 is coated with metal matrix 18 by any suitable method, for example physical vapour deposition, sputtering etc. Each metal-coated 18 ceramic fibre 14 is wound around a mandrel to form an annular, or disc shaped, fibre preform 20 as shown in FIGS. 2 and 3 . Each annular, or disc shaped, fibre preform 20 thus comprises a single metal coated ceramic fibre 14 arranged in a spiral with adjacent turns of the spiral abutting each other. A glue 22 is applied to the annular, or disc shaped, fibre preform 20 at suitable positions to hold the turns of the spiral together. The glue is selected such that it may be completely removed from the annular, or disc shaped, fibre preform 20 prior to consolidation. The glue 22 may be for example polymethyl-methacrylate in dichloromethane or Perspex (RTM) in dichloromethane.
A first metal ring, or metal disc, 30 is formed and an annular axially extending groove 32 is machined in one radially extending and axially facing face 34 of the first metal ring 30 , as shown in FIG. 4 . The annular groove 32 has straight parallel sides, which form a rectangular cross-section. A second metal ring, or metal disc, 36 is formed and an annular axially extending projection 38 is machined from the second metal ring, or metal disc, 36 such that it extends from one radially extending and axially facing face 40 of the second metal ring, or metal disc 36 . The second metal ring, or metal disc, 36 is also machined to form two annular grooves 42 and 44 in the face 40 of the second metal ring, or metal disc 36 . The annular grooves 42 and 44 are arranged radially on opposite sides of the annular projection 38 and the annular grooves 42 and 44 are tapered radially from the face 40 to the base of the annular projection 38 . It is to be noted that the radially inner and outer dimensions, diameters, of the annular projection 38 are substantially the same as the radially inner and outer dimensions, diameters, of the annular groove 32 .
One or more of the annular fibre preforms 20 are positioned coaxially in the annular groove 32 in the face 34 of the first metal ring 30 . The radially inner and outer dimensions, diameters, of the annular fibre preforms 20 are substantially the same as the radially inner and outer dimension, diameters, of the annular groove 32 to allow the annular fibre preforms 20 to be loaded into the annular groove 32 while substantially filling the annular groove 32 . A sufficient number of annular fibre preforms 20 are stacked in the annular groove 32 to partially fill the annular groove 32 to a predetermined level, as shown in FIG. 4 .
The second metal ring 36 is then arranged such that the face 40 confronts the face 34 of the first metal ring 30 and the axes of the first and second metal rings 30 and 36 are aligned such that the annular projection 38 on the second metal ring 36 aligns with the annular groove 32 in the first metal ring 30 . The second metal ring 36 is then pushed towards the first metal ring 30 such that the annular projection 38 enters the annular groove 32 .
The annular fibre preforms 20 are not locally perfectly flat, i.e. adjacent turns of the metal coated ceramic fibre 14 are slightly out of plane due to necessary clearances and slight variation in the diameter of the metal coated ceramic fibre 14 , see FIG. 5 . Consequently, the annular fibre preforms 20 are not ideally packed in the annular groove 32 and thus there are undesirable excess free spaces, which will prevent the face 40 of the second metal ring 36 from abutting the face 34 of the first metal ring 30 .
A small quantity of a solvent, for the glue, is introduced into the annular groove 32 in order to soften the glue 22 and the second metal ring 36 is pressed towards the first metal ring 30 so as to move the individual metal coated ceramic fibres 14 of the annular fibre preforms 20 , see FIG. 6 . The metal coated ceramic fibres 14 of the annular spiral preforms 20 are able to move small distances while they are constrained by the adjacent annular spiral preforms 20 in order to move adjacent turns of the metal coated ceramic fibres 14 closer to, or into, plane to achieve a greater packing density of the metal coated ceramic fibres 14 , which will allow the face 40 of the second metal ring 36 to abut the face 34 of the first metal ring 30 , as shown in FIG. 7 . The metal coated ceramic fibres 14 of each annular fibre preform 20 are closer to being planar and this reduces the risk of the metal coated ceramic fibres 14 moving out of position and crossing the metal coated ceramic fibres 14 of adjacent fibre preforms 20 and hence reducing the risk of damage, breakage, of the metal coated ceramic fibres 14 during the consolidation. The locally applied glue 22 is dispersed by the solvent so that the glue 22 is more widespread, but thinner, and then the glue 22 re-hardens. The glue 22 is then more easily removed later.
The radially inner and outer peripheries of the face 34 of the first metal ring 30 are sealed to the radially inner and outer peripheries of the face 40 of the second metal ring 36 to form a sealed assembly. The sealing is preferably by TIG welding, electron beam welding, laser welding or other suitable welding processes to form an inner annular weld seal 46 and an outer annular weld seal 48 as shown in FIG. 7 .
The sealed assembly is evacuated using a vacuum pump and pipe 50 connected to the grooves, or chambers, 42 and 44 . The sealed assembly is then heated, while being continuously evacuated to remove the glue 22 from the annular fibre preforms 20 and to remove the glue 22 from the sealed assembly.
After all the glue 22 has been removed from the annular fibre preforms 20 and the interior of the sealed assembly is evacuated, the pipe 50 is sealed. The sealed assembly is then heated and pressure is applied to the sealed assembly to produce axial consolidation of the annular fibre preforms 20 and diffusion bonding of the first metal ring 30 to the second metal ring 36 and diffusion bonding of the metal on the metal coated 18 ceramic fibres 14 to the metal on other metal coated 18 ceramic fibres 14 , to the first metal ring 30 and to the second metal ring 36 . During the application of heat and pressure the pressure acts equally from all directions on the sealed assembly, and this causes the annular projection 38 to move axially into the annular groove 32 to consolidate the annular fibre preforms 20 .
The resulting consolidated and diffusion bonded ceramic fibre reinforced component is shown in FIG. 8 which shows the ceramic fibres 14 and the diffusion bond region 62 . Additionally the provision of the annular grooves, or chambers, 42 and 44 allows the annular projection 38 to move during the consolidation process and in so doing this results in the formation of a recess 63 in the surface of what was the second metal ring 36 . The recess 63 indicates that successful consolidation has occurred.
After consolidation and diffusion bonding the article 60 is machined to remove at least a portion of what was originally the first metal ring, at least a portion of the second metal ring and at least a portion of the diffusion bonded region. In the example the majority of the second metal ring and the majority of the diffusion bonded region is removed. Thus the fibre reinforced area is retained in it's intended shape with straight, flat, sides and thus the machining is in planes to produce flat, planar, surfaces on the article to provide a uniform distance between the surfaces and the fibre reinforced areas.
The article may then be machined for example by electrochemical machining or milling to form the integral compressor blades 16 , as shown in FIG. 1 , or the article may be machined to form one or more slots to receive the roots of the compressor blades.
Alternatively, compressor blades may be friction welded, laser welded or electron beam welded onto the article.
The reinforcing fibres may comprise alumina, silicon carbide, silicon nitride, boron or other suitable fibre.
The metal coating on the reinforcing fibre may comprise titanium, titanium aluminide, titanium alloy, aluminium, aluminium alloy, copper, copper alloy or any other suitable metal, alloy or intermetallic which is capable of being diffusion bonded.
The first metal ring and the second metal ring comprise titanium, titanium aluminide, titanium alloy, aluminium, aluminium alloy, copper, copper alloy or any other suitable metal, alloy or intermetallic which is capable of being diffusion bonded.
Although the present invention has been described with reference to spirally wound metal coated fibres alone, the present invention is also applicable to the use of fibre preforms 20 A comprising spirally wound metal coated 18 ceramic fibres 14 and wire preforms 24 A comprising spirally wound metal wires 26 , as shown in FIGS. 9 and 10 . In FIGS. 9 and 10 each fibre preform 20 A is arranged in the same plane as an associated wire preform 24 A, but each wire preform 24 A is at a greater diameter. The preforms 20 A and 24 A may be arranged in different planes.
Although the present invention has been described with reference to the introduction of a small quantity of solvent into the annular groove in the first metal ring to soften the glue on the annular fibre preforms, it is equally possible to flow solvent vapour or liquid solvent through the annular groove to soften the glue on the annular fibre preforms. A further alternative is to flow a hot fluid, for example argon or other inert gas or gas that is non reactive with the metal, through the annular chamber to soften the glue on the annular preforms. An additional alternative is to heat the first and second metal rings to a temperature sufficient to soften the glue on the annular fibre preforms.
Additionally the present invention is applicable to the use of spirally wound ceramic fibres and metal foils, helically wound ceramic fibres in a metal ribbon, spirally wound fibres and spirally wound metal wires or other form of metal filler.
The metal wire may comprise titanium, titanium aluminide, titanium alloy or any other suitable metal, alloy or intermetallic which is capable of being diffusion bonded. The metal foil, metal ribbon or other metal filler may comprise titanium, titanium aluminide, titanium alloy or any other suitable metal, alloy or intermetallic which is capable of being diffusion bonded.
Although the present invention has been described with reference to providing a circumferentially extending groove in an face of a first metal ring and a circumferentially extending projection on an face of a second metal ring it is equally applicable to the provision of a circumferentially extending groove on a radially outer or inner face of a ring. The circumferentially extending groove may be defined by a radially extending removable member. The present invention is also applicable to the use of a plurality of fibres, or metal coated fibres, extending in a single direction with the fibres, or metal coated fibres, being arranged in layers and with the layers being stacked upon each other.
The present invention is also applicable to any arrangement where the fibres are placed between two or more metal components.
Although the present invention has been described with reference to reinforcement of metal rings it is equally applicable to other arrangements and in such cases the reinforcing metal-coated fibres will be arranged accordingly.
Although the present invention has been described with reference to the placing of the filler metal and the ceramic fibres between two metal components and the diffusion bonding of the filler metal and two metal components, the filler metal and ceramic fibres may be placed between two tools but the filler metal is not bonded to the tools.
The advantages of the present invention is that it produces a higher “green” density of the fibre preforms which reduces volume changes during consolidation and hence controls the shape and position of the fibre reinforced area of the finished article. The higher “green” density maintains the positions of the metal-coated fibres and reduces the risk of metal-coated fibres moving out of position and subsequent breakage during consolidation. The smaller enclosed volume and the reduced excess space enables the use of a smaller and cheaper evacuation system. The ability to tolerate less than perfectly flat fibre preforms allows wider tolerances on the fibre winding equipment, which in turn avoids the need for high precision and expensive fibre winding equipment.
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A method of manufacturing a fibre reinforced metal matrix composite article, the method comprising placing metal coated ( 18 ) fibers ( 14 ) between a first metal ring ( 30 ) and a second metal ring ( 36 ). Each of the metal-coated ( 18 ) fibres ( 14 ) having a glue ( 22 ) to hold the metal-coated ( 18 ) fibers ( 14 ) in position. A solvent is supplied to the glue ( 22 ) on the metal-coated ( 18 ) fibers ( 14 ) to soften the glue ( 22 ) and pressure is applied to allow the metal-coated ( 18 ) ceramic fibers ( 14 ) to become more closely packed. Thereafter the glue ( 22 ) is removed and the metal coated ( 18 ) fibers ( 14 ) and first and second metal rings ( 30, 36 ) are consolidated and diffusion bonded together.
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RELATED CASES
[0001] This application is a continuation in-part application and claims the benefit of U.S. NonProvisional application Ser. No. 12/198,466, filed Aug. 26, 2008.
ORIGIN OF THE INVENTION
[0002] The invention described herein was made by an employee of the United States Government, and may be manufactured and used by or for the Government for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention is generally related to space-based imaging and more particularly to accurately sensing and controlling the wave-front in a space-based imaging interferometer.
[0005] 2. Background Description
[0006] National Aeronautics and Space Administration (NASA) has been developing interferometric space-based imaging to realize future larger aperture science missions. Imaging interferometers contain an array of two (2) or more telescopes, or apertures, that coherently mix (interferometrically combine) images in a resultant high-resolution image, effectively synthesizing a single aperture. Misaligning the mirrors degrades the image wave-front, blurring or aberating images. Misalignment can even cause multiple images, with severe misalignment causing one per aperture or telescope.
[0007] Thus, the ability to sense and control the individual aperture misalignments is paramount to achieving high quality images. Typically, individual misalignments are quantified/encoded as what is known as wave-front error(s). The wave-front errors may be used as feedback control to adjust the mirror positions in what is known as wave-front control. Interferometric missions will require wave-front control onboard with the mirrors.
[0008] To that end the NASA Goddard Space Flight Center (NASA/GSFC) has developed the Fizeau Interferometry Testbed (FIT), to study wave-front sensing and control methodologies for future NASA interferometric missions, e.g., the Stellar Imager mission (hires.gsfc.nasa.gov/˜si). The FIT includes from 7-18 articulated mirrors (elements) in a non-redundant Golay pattern that focuses input light into an interferometric white light image. While coarse alignment, dithering combinations of mirrors to eliminate extra images for severe misalignment, may relatively straightforward; finer alignment necessary for high quality imaging requires accurate wave-front sensing and controlling each of the articulated mirrors. Even with such precise control, correctly aligning a number of articulated mirrors with each other can be a long, exhausting, iterative process. Previously, this was a computationally intensive process that required an unacceptably high number of iterations to converge.
[0009] Thus, there is a need for quick, compact wave-front sensing for efficiently aligning and controlling articulated mirrors in an array of mirrors in interferometric imaging systems.
SUMMARY OF THE INVENTION
[0010] It is an aspect of the invention to quickly align articulated mirrors in an array of mirrors;
[0011] It is another aspect of the invention to facilitate wave-front sensing and control of articulated mirrors in an array of mirrors;
[0012] It is yet another aspect of the invention to minimize the wave-front sensing and control time required to align and simplify control of articulated mirrors in an array of mirrors used in an interferometric imaging system.
[0013] The present invention relates to a method of aligning an array of mirrors, apertures or telescopes, and computer program product therefor. The method may be used to align multiple apertures or telescopes in a sparse aperture telescope system, e.g., a spaced based imaging interferometer. The multiple apertures focus light from an external source, e.g. a star, to an image on a sensor. The focused light interferometrically combines all the light from the individual apertures to produce a spatial image. A local computer processes the spatial image, algorithmically, to extract the spatial frequency sidebands in pairwise fashion, where pairwise refers to interference from two separate apertures. Piston differences and tip and tilt sums result from this pairwise extraction, where the piston difference is the path length difference between 2 apertures and tip/tilt sums are the sum of the tip/tilts of the same pair of apertures. Since piston, tip and tilt quantify aperture position, wave-front error is linearly related to piston, tip and tilt. Thus, using linear algebraic techniques, each set of pairwise piston differences and tip and tilt sums translate into individual aperture piston, tip and tilt positions. Subsequently, individual aperture piston, tip and tilt positions are used to generate commands (feedback) to control the mirrors positions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which:
[0015] FIG. 1 shows an example of application of the present invention in providing remote onboard wave-front sensing and control to quickly align before and, maintain alignment during, science observations and after array reconfigurations in the NASA SI;
[0016] FIG. 2 shows a schematic example of the NASA/GSFC Fizeau Interferometry Testbed (FIT) developed for studying wave-front sensing and control methodologies for SI;
[0017] FIG. 3 shows an example of a suitable method of wave-front sensing and control alignment;
[0018] FIG. 4 shows an example of steps in direct solve image-based wave-front sensing 140 according to a preferred embodiment of the present invention;
[0019] FIGS. 5A-E show pictorial examples of the steps in determining local piston differences;
[0020] FIGS. 6A-E show pictorial examples of those steps in determining tip and tilt sums;
[0021] FIG. 7A shows an example of constrained linear equations for converting piston differences (Δp ij ) to mirror pistons (p i , p j ) for mirrors i and j;
[0022] FIG. 7B shows a matrix solution example of the constrained piston differences, using a simple sparse matrix solution to converts from the direct solve phase retrieval piston differences to actual mirror piston per mirror.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] Turning now to the drawings and more particularly FIG. 1 shows an example of a National Aeronautics and Space Administration (NASA) space-based imaging interferometer, e.g., the NASA Stellar Imager (SI). In this example, application of the present invention provides remote onboard wave-front sensing and control to maintain aperture alignment during science observations and after array reconfigurations. SI is an ultraviolet (UV) optical interferometry mission in the NASA Sun-Earth 100 , 102 connection, far-horizon roadmap. Such a mission requires both spatial and temporal resolution of stellar magnetic activity patterns 104 , representing a broad range of activity level from stars 106 . Studying these magnetic activity patterns 104 enables improved forecasting of solar/stellar magnetic activity as well as an improved understanding of the impact of that magnetic activity on planetary climate and astrobiology. SI, for example, may also allow for measuring internal structure and rotation of the stars 106 using the technique of asteroseismology and relating asteroseismology to the respective stellar dynamos 106 .
[0024] SI may also image central stars in external solar systems (not shown) and enable an assessment of the impact of stellar activity on the habitability of the planets in those systems. Thus, SI may complement assessments of external solar systems that may be done by planet finding and imaging missions, such as the Space Interferometer Mission (SIM), Terrestrial Planet Finder (TPF) and Planet Imager (PI). SI employs a reconfigurable sparse array of 30 one-meter class spherical mirrors (e.g., 108 ) in a Fizeau mode, i.e., an image plane beam combination, with maximum baseline length up to ˜500 meters, yielding 435 independent spatial frequencies of the image. An earth orbit satellite or other vehicle 109 collects reflected image data and relays the collected information to earth 102 .
[0025] Presently, imaging interferometry requires sensing path lengths to a fraction of the observing wavelength of light and controlling optical path lengths to a fraction of the coherence length, i.e., λ 2 /Δλ=λR. For example, λ=1550 Angstroms (1550 Å) at a spectral resolution R=100 implies sensing to λ/10=155 Å and effective control to <15.5 microns (15.5μ) in direct imaging mode provided tip/tilt per sub-aperture is corrected to better than 1.22λ/D=40 milli-arcseconds (mas) at the shortest wavelength. NASA Goddard Space Flight Center (NASA/GSFC) developed the Fizeau Interferometry Testbed (FIT) to study wave-front sensing and control methodologies for SI and other large, interferometric telescope systems.
[0026] FIG. 2 shows a schematic example of the FIT 110 , which includes in this example a light source 112 directing light at a hyperboloidal secondary mirror 114 . The hyperboloidal secondary mirror 114 reflects and redirects the light to an off axis parabola (OAP) collimator 116 or OAP. Collimated light from the OAP 116 is directed to interferometric mirror array 118 . Light reflected from the interferometric mirror array 118 is redirected by an elliptical secondary mirror 120 to focal 122 , where the light from the individual mirrors 118 combine interferometrically into the resultant image.
[0027] Initially, FIT 110 was designed to operate at optical wavelengths using a minimum-redundancy array for segments of the primary mirror 118 . Light from the source assembly 112 can illuminate an extended-scene film located in the front focal plane of the collimator mirror assembly, which includes the hyperboloid secondary mirror 114 and the off-axis paraboloid primary 116 . The elements of the primary mirror array 118 are each positioned to intercept the collimated light, and relay it to the oblate ellipsoid secondary mirror 120 , which subsequently focuses relayed light onto the image focal plane 122 .
[0028] Previously, an optical trombone arrangement was used near the focal plane to allow 2 out-of-focus images to be simultaneously recorded on two CCD cameras for subsequent phase-diversity wave-front analysis in a typical state of the art computer. This optical trombone arrangement was proposed as a backup for the Hubble Space Telescope, and further, in diagnosing the initial problems with Hubble and estimating the quality of the fix. See, e.g., Grey et al., “Correction of Misalignment Dependent Aberrations of the Hubble Space Telescope,” Proc of SPIE 1168, August 1989; Lyon et. al, “Hubble Space Telescope Phase Retrieval: A Parameter Estimation,” Proc of SPIE 1567, July 1991; and Lyon, et. al., “Hubble Space Telescope Faint Object Camera Calculated Point Spread Functions,” Applied Optics, Vol. 36, Nov. 8, 1997. Moreover, the James Webb Space Telescope uses an optical trombone arrangement. See, e.g., Lyon et. al, “Extrapolating HST Lesions to NGST,” Optics and Photonics News, Vol 9, Nov. 7, 1998.
[0029] Unfortunately, however, this optical trombone arrangement has proven highly inefficient for space based imaging interferometry. It requires splitting the light into two paths, which lowers the signal-to-noise ratio. Further, it requires two CCD cameras and introduces non-common path errors in the wave-front sensing. This is all beyond the computing power of state of the art computers that are compact and light enough for onboard computers. Thus, such an optical trombone arrangement makes implementing an interferometric space mission much more costly and complex.
[0030] By contrast a preferred embodiment direct solve approach directly addresses these problems, requiring only a single in-focus, but broadband image collected on a single CCD camera. A computer, which may or may not be the same computer, manipulates piezo actuators that control the aperture pistons positioning articulated primary mirror elements, and that control data acquisition by the CCD arrays mirror assembly, the hyperboloid secondary mirror 120 and OAP primary mirror 116 in the FIT 110 . The primary mirror array 118 elements intercept the collimated light and relay it to the oblate ellipsoid secondary mirror 120 , which finally focuses the collimated light onto the focal 122 . The FIT 110 optics and mechanics are described in detail at hires.gsfc.nasa.gov/˜si and, moreover may be found in Richard G. Lyon et al., “Wave-front Sensing and Closed-Loop Control for the Fizeau Interferometry Testbed,” Proceedings of SPIE, Volume: 6687, 12 Sep. 2007, the contents of which are incorporated herein by reference.
[0031] As noted hereinabove, the distributed spacecraft in the NASA SI space-based ultraviolet (UV) imaging interferometer will require onboard wave-front sensing and control to maintain alignment during observations and after array reconfigurations. For example, an on-board flight processor may use images collected by a science camera located in the SI hub spacecraft ( 109 in FIG. 1 ). Thus to insure that this requirement is satisfied, FIT 110 is equipped with wave-front sensing and control according to a preferred embodiment of the present invention.
[0032] FIG. 3 shows an example of a suitable method of wave-front sensing and control alignment 130 according to a preferred embodiment of the present invention, e.g., as may be implemented in FIT 110 of FIG. 2 . This preferred example includes four (4) primary stages Coarse-Coarse alignment/control 132 , Coarse Tip/Tilt adjustment 134 , Coarse Piston adjustment 136 , and Fine Piston/Tip/Tilt adjustment 138 according to a preferred embodiment of the present invention.
[0033] Wave-front control 130 begins with Coarse-Coarse alignment/control 132 , which occurs when the system 110 is initially turned on. The focal planes 122 collect a single white light image of an unresolved source. If the system 110 is unaligned a number of spots (primary beam images) appear in the focal plane 122 with each spot having a determinable flux. If the number of spots does not match the number of mirrors in the primary mirror array 118 , then some may be overlapping and each spot is checked. If the number of spots are less than the number of mirrors, then each mirror is dithered. Dithering introduces tip and/or tilt into each of the mirrors. The tip/tilt is introduced in various different directions and by different amounts for each mirrorlet. Then, a new image is collected and compared to (differenced from) the preceding image. The differences identify which mirror corresponds to which spot.
[0034] Coarse Tip/Tilt adjustment 134 uses a sigma-centroid algorithm to find the centroid of all the spots and to crop the image acquisition region. By first locating the mean and the standard deviation of the entire image, the result may be pared to only those points that fall above the mean plus 1 sigma to determine the centroid, i.e. the flux weighted center of mass of the image. The image acquisition region is an area centered on the centroid. Again, the spots are matched with mirrors, this time using a smaller tip/tilt dither and a simple estimate of the mapping from actuator tip/tilt to motion of the spot on the CCD grid of focal planes 122 . At this point the mirrors are coarse corrected for tip/tilt but, because of significant piston errors between the mirrors, have not been phased.
[0035] Coarse Piston adjustment 136 brings each of the baseline pairs piston difference to within a coherence length of each other. Coarse Piston adjustment 136 begins by first unstacking the images, i.e. moving all the mirrors such that the pattern of spots emulates the aperture pattern. Then, continuing by moving two of the mirrors in tip/tilt such that they overlap in the center of the image acquisition region and dithering the respective pistons (not shown) until interference starts to occur. This can be performed for each baseline pair sequentially or for two or more in parallel. Once Coarse Piston adjustment 136 is complete, all the mirrors have been tip/tilted to the center and partially piston corrected such that all piston errors are within ±0.61 λB/D. However, since the tip/tilt motion of the actuators is not totally separable from the piston motion, the mirrors are still only partially pistoned.
[0036] Fine Piston/Tip/Tilt adjustment (or fine phasing) 138 uses direct solve image-based wave-front sensing to determine local piston difference, tip and tilt sums for each baseline pair according to a preferred embodiment of the present invention. Generally, fine phasing 138 takes a more global approach using only a single white light in-focus point spread function, and simultaneously using all mirrors in the array 118 to solve for piston differences and tip/tilt sums on a per baseline pair basis and. Further, by collecting images from the focal planes 122 and solving for the optical wave-front, the collected wave-front is proportional to optical misalignments, design errors, fabrication errors and may be used as a diagnostic to assess the performance of the optical system. Unlike prior fine phasing approaches, direct solve image-based wave-front sensing provides a wave-front solution directly from a single image without defocusing and without resorting to nonlinear iterative algorithms.
[0037] FIG. 4 shows an example of steps in direct solve image-based wave-front sensing 140 according to a preferred embodiment of the present invention. FIGS. 5A-E show corresponding pictorial examples of the steps in determining local piston differences and FIGS. 6A-E show corresponding pictorial examples of those steps in determining tip and tilt sums. Direct solve image-based wave-front sensing 140 is a closed loop solution that converges quickly after a relatively small number of iterations as opposed to other prior approaches.
[0038] Beginning in step 142 of FIG. 4A , the focal planes 122 collect an image, amplitude 1420 and phase 1422 , from a single, white-light, in-focus, point spread function (PSF) for each pair of mirrors in the array 118 . Typically, unselected mirrors are blocked (e.g., masked off or closed aperture) during testing of a selected pair. So, as reflected by the corresponding example of FIG. 5A , the amplitude or pupil component 1420 of the collected image includes an amplitude component 1420 - 1 and 1420 - 2 for each of the pair of mirrors (not shown), indexed 1 and 2 for convenience of discussion herein. Likewise the phase component 1422 includes a phase component 1422 - 1 and 1422 - 2 for each of the pair of mirrors. The respective image renderings combine in step 144 in an in-focus, white-light, sparse-aperture optical PSF of the region 1440 in FIG. 5B . If the mirrors are both properly aligned (i.e., the respective pistons are aligned and the mirror tip/tilt sums are correct), the PSF 1440 reflects a single spot. Since in this example the mirrors are not aligned, the PSF 1440 reflects two spots 1440 - 1 and 1440 - 2 .
[0039] In step 146 , the PSF 1440 is Fourier Transformed (FT) to extract real and imaginary optical transfer function (OTF) components (Re{OTF}) 1460 , (Im{OTF}) 1462 in FIG. 5C . Each component 1460 , 1462 includes a carrier component 1460 c, 1462 c and two identical sideband components 1460 s, 1462 s. The real component (Re{OTF}) 1460 and imaginary component (Im{OTF}) 1462 are passed to an extractor/shifter 148 . The extractor/shifter 148 extracts the sidebands 1460 s, 1462 s and shifts the result to change the carrier frequency (OTF*), resulting in real and imaginary components (Re{OTF*}) 1480 , (Im{OTF*}) 1482 in FIG. 5D . Inverse Fourier Transforming (FT −1 { }) 150 the shifted components (Re{OTF*}) 1480 , (Im{OTF*}) 1482 provides spatial images 1500 , 1502 in FIG. 5E with the form: Ψ=2ghe ik(p1−p2) .
[0040] The in-phase portion ((φ pist ) of Ψ gives piston information as the difference for the two pistons is p 1 −p 2 . The 2gh term is tip/tilt information for the baseline pupils, where g is the Fourier Transform of one pupil and h is the Fourier Transform of the other and [g] 2 +[h] 2 contains a mix of all other baselines. In particular, the in-phase of the term may be determined 152 from the arctangent of the ratio of the imaginary to real components of Ψ, i.e., φ pist ={Im{Ψ}/Re{Ψ}}. Thus, the piston difference for two mirrors may be determined 154 from the arcsine of the sine of the in-phase of the term and has the form: p 1 −p 2 =λ/2π sin −1 [sin φ pist ].
[0041] Determining the tip/tilt sums begins by taking 160 the real component part of gh, 1600 in FIG. 6A , i.e., (Ψ/2)e −iφpist ε R, which has a real component 1602 and a discarded imaginary component 1604 . Next, in step 162 the real component 1602 is Fourier Transformed (Γ=FT{(Ψ/2)e −iφpist }) 1620 , which provides real and imaginary components 1622 , 1624 in FIG. 6B . In step 164 , Γ provides ( 1640 in FIG. 6C ) an image (Φ Γ ) 1642 and phase components (sin Φ Γ ) 1644 , (cos Φ Γ ) 1646 . Since mirror tip/tilt differences manifest as phase variations (i.e., a gradient) in step 166 , 2D changes are extracted from the phase 1660 in FIG. 6D , i.e., changes in the x direction (d(sin Φ Γ )/dx) 1662 and the y direction (d(sin Φ Γ )/dy) 1664 . In step 168 , the extracted 2D changes are normalized 1680 in FIG. 6E , i.e., divided by cos Φ 1 , providing tip/tilt components 1682 , 1684 . This eliminates sign ambiguities and/or phase unwrapping problems (from phase >, or multiple of, 2π) for a non-redundant aperture. The tip/tilt sums may be determined by integrating the normalized differences 1686 over the focal area, where a 1 , a 2 , b 1 and b 2 are tip/tilt values for the respective mirrors.
[0042] The values of a, b and p are extracted in step 170 , e.g., using any suitable well-known curve fitting technique. In step 172 another pair of mirrors is selected until differences and sums have been selected and applied, when the result is compared with the preceding values. If the difference of the comparison is within an acceptable threshold value (δ), a solution has been found and direct solve ends in step 174 . Otherwise, if the new values are not within δ of the old, in step 172 the new values are applied to the mirrors. Then, returning to step 144 , the focal plane 122 collects amplitude 1420 and phase 1422 from a single white light with pair of mirrors in the array 118 adjusted according to the new values an another iteration begins.
[0043] FIG. 7A shows an example of constrained linear equations for converting piston differences (Δp ij ) to mirror pistons (p i , p j ) for mirrors i and j. These equations are subject to the constraint that the sum of the n pistons is zero, where n is the number of mirrors, i.e.,
[0000]
∑
j
=
1
n
p
j
=
0.
[0000] By introducing arbitrary biases to maintain this constraint, the set of piston motions remain in the center of the actuator range.
[0044] FIG. 7B shows the constrained piston differences expressed in matrix formalism 180 to yield a solution 182 that, using a simple sparse matrix multiply, converts from the direct solve phase retrieval piston differences (p 1 , p 2 ) to actual mirror piston locations. The tip/tilt sums may be similarly determined with the incorporation of a rotation matrix for the de-rotations from the different baseline vector directions. Ultimately, however, this yields a simple matrix multiplication for tip/tilt sum determination as well.
[0045] Advantageously, direct solve sensing provides a simple image-based wave-front sensing approach that, unlike other approaches, uses a single in-focus white-light image to solve directly for piston differences and tip/tilt sums. Focus and/or wavelength dithering is unnecessary to consistently and quickly (˜0.01 seconds) arrive at a solution in a minimal number of floating point operations on a simple, single process computer. Further, direct solve avoids sign ambiguities and/or phase unwrapping problems for a non-redundant aperture that are otherwise encountered. Finally, because of its simplicity, any state of the art onboard computer may implement direct solve for space based wave-front sensing and control.
[0046] While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims. It is intended that all such variations and modifications fall within the scope of the appended claims. Examples and drawings are, accordingly, to be regarded as illustrative rather than restrictive.
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A method of aligning an array of mirrors and computer program product therefor. The method may be used to align mirrors in a sparse aperture telescope system, e.g., a spaced based imaging interferometer. An image projected onto mirrors in an array of mirrors is reflected onto a sensor, where a point spread function (PSF) is collected from a pair of mirrors. A spatial image is extracted from PSF sidebands and a difference (e.g., piston difference) is determined for the pair of mirrors from the spatial image. Tip and tilt are determined for the pair of mirrors from spatial image characteristics.
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The present application is a continuation-in-part of copending U.S. patent application Ser. No. 849,044 filed on Nov. 7, 1977 and entitled "EAR ORNAMENT CLIPS," which in turn is a continuation of U.S. patent application Ser. No. 724,970 filed on Sept. 20, 1976 and entitled "EAR ORNAMENT CLIPS", now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to ear ornament clips which include front and back parts which are so dimensioned and connected together as to provide greater ease in handling and application than prior ear ornament clip constructions.
An ear ornament clip construction is disclosed in United Kingdom Patent Specification No. 976,341, and the form in which the ear ornament clip disclosed therein has been marketed for more than ten years is illustrated in FIGS. 7 and 8 of the accompanying drawings.
FIG. 7 of the drawings illustrates a first clip member 10 (hereinafter called the front part) and a second clip member 11 (hereinafter called the back part) which are pivotally connected together at 12, the back part being in the position which it is able to occupy, and will in practice occupy, when the two parts have been separated to release the ear lobe. This condition of the clip, and indeed of any ear ornament clip, will be hereinafter referred to as the fully open condition. It will be appreciated that for a woman to apply the clip and the ornament carried thereby to her ear lobe, it will be necessary for her to put, for instance, her index finger in contact with the front surface of ornament 13 and the tip of her thumb in contact with the surface 14 of the back part 11. However, instead of being able to simply squeeze the front part 10 and the back part 11 towards each other, she must first push the back part upwardly about pivotal axis 12 relative to front part 10 in order to bring that back part into the position thereof which is illustrated in FIG. 8 of the accompanying drawings.
In practice, this necessity proves to be a complication from the woman's point of view because the ear ornament clip is extremely small and its smallness makes it very easy for a woman to inadvertently drop the clip in the course of trying to apply it to an ear lobe. In fact, the smaller the ornament 13 is, the more difficult is the task of application of the clip to the ear lobe. If the ornament were circular and of the diameter shown in FIG. 8 in full line, it would be relatively easy for the tip of the index finger and the ball of the thumb to exert a clip-closing force along, i.e., the line A--A shown in FIG. 8 whereas, if the ornament (for example, a small pearl) were to be of the size shown in dotted line in FIG. 8, the ability of the woman to exert pressure along line A--A without either the index finger or the thumb slipping off would diminish very considerably because the index finger would have much less area of ornament to which to apply the force. In fact, in experiments which have been conducted, particularly when the ornament carried by the front part 10 is quite small, it has been found that (with the front and back parts in the FIG. 8 positions) the index finger and thumb sometimes exert the force along line B--B because the thumb is not actually far enough along the back part 11 towards the curved end part 15 thereof. Discovery of this problem necessitates re-positioning of the clip carefully between the tips of the index finger and thumb and even then the closure of the clip to the lobe-gripping condition thereof can be quite a slow process.
SUMMARY OF THE INVENTION
The principal object of the present invention is to provide a clip construction in which the above-discussed drawbacks are completely overcome, or at least significantly reduced.
To this end, the present invention provides an ear ornament clip which includes a front part and a back part, with the front and back parts being so connected to one another as to permit angular movement of the parts relative to each other in order to grip or release a wearer's ear lobe. The front part has a first portion of which one face is adapted to carry the ornament and of which the other face is adapted to be placed in contact with that surface of the wearer's ear lobe against which the ornament is to be displayed. The front part also has a second portion integral with the first portion and including elements which are so joined to one another at corresponding one ends thereof as to form resilient elements substantially in the form of a modified V or spread U, the corresponding other and free ends of the elements extending substantially parallel to the first portion of the front part. The back part has a first portion which includes a face of which at least a portion thereof is adapted to be placed in contact with that surface of the wearer's ear lobe which is remote from the surface thereof against which the ornament is to be displayed, and the back part further has a second portion which is integral with the first portion thereof and which comprises substantially parallel legs. The front part has first means disposed near the resilient elements and the back part has second means disposed near the free ends of the legs, the first and second means cooperating to form a pivotal connection between the front and back parts. Relative angular movement of the front and back parts to a condition in which an ear lobe becomes gripped between the first portion of the front part and the first portion of the back part not only causes the lobe-gripping portions of the front and back parts of the clip to become disposed substantially directly opposite to each other, but also causes the inside surfaces of the legs to frictionally slide along the outside surfaces of the resilient elements towards the free ends of the resilient elements and to force the resilient elements together to establish and maintain the desired lobe-gripping condition of the front and back parts.
In the preferred embodiment, the first portion of the back part of the clip is substantially U-shaped with diverging legs, the first diverging leg having a free end, and the second diverging leg being integral with the second portion of the back part. The free end of the first diverging leg comprises the lobe contacting portion of the first portion of the back part of the clip.
Other objects and details of the invention will become apparent from the following description, when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a side elevation view of an ear ornament clip according to the invention, shown in the fully open condition.
FIG. 2 illustrates a side elevation view of the clip of FIG. 1, shown in an ear lobe gripping condition.
FIG. 3 is an enlarged view of the clip taken along line 3--3 of FIG. 1.
FIG. 4 is an enlarged view of the clip taken along line 4--4 of FIG. 2.
FIG. 5 depicts a perspective view of the front part of an ear ornament clip in accordance with the invention.
FIG. 6 illustrates a perspective view of the back part of an ear ornament clip in accordance with the invention.
FIGS. 7 and 8 illustrate different conditions of a prior art ear ornament clip as discussed hereinabove.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
There is hereby incorporated by reference thereto the entire disclosure of the aforementioned U.S. patent application Ser. No. 724,970 filed on Sept. 20, 1976 and U.S. patent application Ser. No. 849,044 filed on Nov. 7, 1977.
With reference to FIG. 5, there is illustrated a front part 20 of the two-part ear ornament clip according to the invention. The front part 20 has a first portion 21 of which one face 22 is adapted to carry the ornament (not illustrated) and of which the other face 23 is adapted to be placed in contact with that surface of the lobe of the wearer's ear against which the ornament is to be displayed. The front part 20 also has a second portion 24 which is integral with the first portion 21 and which includes elements 25 which are so joined to one another at corresponding one ends thereof as to form resilient elements substantially in the form of a V having a flattened lower portion, the corresponding other and free ends 26 of the resilient elements 25 extending substantially parallel to the first portion 21 of front part 20.
As shown in FIG. 5, the two divergent elements 25 are substantially identical. Located near the resilient elements 25 are two lugs 27, in which coaxial apertures 28 are formed, one of the lugs 27 and the aperture 28 being partially hidden from view behind one of the resilient elements 25 in FIG. 5. The first portion 21 has an aperture 29 in the enlarged free end 30 thereof, the end 30 and aperture 29 being provided for support and attachment of certain kinds of ornaments, discussed more fully hereinbelow.
With reference to FIG. 6, there is illustrated a back part 40 of the two-part ear ornament clip. Back part 40 has a first portion 41 which includes a face 42, the end portion 41a of which is adapted to be placed in contact with that surface of the lobe of the wearer's ear which is remote from the surface thereof against which the ornament is to be displayed. Back part 40 also comprises a second portion 43 which is integral with first portion 41 and which is constituted by substantially parallel legs 44. Each leg 44 has near the free end thereof a protuberance or pip 45 formed by upsetting, the pips 45 being coaxial and extending towards one another. The circle seen in FIG. 6 near the free end of the rightmost leg 44 is the depression or dimple formed in that face of the leg 44 when the pip 45 was upset.
Referring now to FIGS. 1 through 4, the front part 20 and the back part 40 are brought together to cause the coaxial pips 45 of back part 40 to snap into coaxial apertures 28 of front part 20. The front part 20 and back part 40 of the clip are each made of substantially springy material, and most preferably of stainless steel. A primary advantage of the invention, which is of importance to anyone having to assemble front part 20 and back part 40, is that their assembly is completed, for example, by simply moving the two parts together in such a manner that the centers of apertures 28 of front part 20 are directed towards the centers of pips 45 of back part 40 until pips 45 have snapped into apertures 28. Due to the shapes of front part 20 and back part 40, the possibility of improperly assembling the two parts is substantially reduced in comparison to the prior art construction depicted in FIGS. 7 and 8 wherein improper assembly of the two parts can easily occur due in part to the comparatively long distance from the edge of the front part to the pivot point.
The clip illustrated in FIGS. 1 through 4 is identical in configuration to the disassembled clip shown in FIGS. 5 and 6, however, in FIGS. 1-4 the clip is shown provided with an added ornamental button 22a. The button 22a is secured to the face 22 of first portion 21 of front part 20 such as by passing suitable securing means through aperture 29. The button 22a can alternatively be either riveted, soldered, or spot welded to end 30. End 30 may be altered to provide for securing an ornament by an adhesive, or by heat (heated tabs on end 30 being pressed into an ornament made of a synthetic resin) and to provide for securing of a pearl bouton ornament. The button 22a shown in FIGS. 1 and 2 is provided with a downwardly projecting small eye 22b which enables the clip to be associated with a pendant decoration.
In FIG. 1, the front part 20 and back part 40 are shown in the fully open condition in which the inside surfaces of substantially parallel legs 44 are no longer in firm frictional engagement with the outer surfaces of the divergent resilient elements 25. This relative position between parallel legs 44 and divergent resilient elements 25 is more clearly depicted in FIG. 3. In this fully open condition of the clip, it can be seen that the free end 41a of first portion 41 of back part 40 is substantially spaced from and above the free ends 26 of resilient elements 25.
It should again be noted that the "fully open" condition of the clip (as shown in FIG. 1) is that relative position of front part 20 with respect to back part 40 in which the two parts are separated so as to either release the ear lobe or in preparation for applying the clip to the ear lobe, and that relative position of the two parts where they are frictionally engaged and able to maintain this position.
In this fully open condition of the clip, a woman will not need to make any such preliminary adjustment of back part 40 relative to front part 20 as was described above with reference to FIGS. 7 and 8, since the clip can be preset to the position shown in FIG. 1. All she will need to do is to pick up the clip and press front part 20 and back part 40 together to bring them into the lobe-gripping condition thereof which is illustrated in FIG. 2. Although the angle through which back part 40 needs to be moved relative to front part 20 is approximately 40°, as can be measured by comparing FIGS. 1 and 2, the inside surfaces of legs 44 contact the outside surfaces of divergent elements 25 at a very early stage, as compared to prior art of the angular movement of back part 40 about the pivotal axis provided by the interengaged pips 45 and apertures 28. Thus, the degree of friction which is ultimately necessary to maintain the clip parts in the relative positions thereof shown in FIG. 2 begins to be developed almost as soon as back part 40 is moved angularly relative to front part 20. The friction developed between legs 44 and divergent elements 25 increases as the elements are constrained to become less divergent, and reaches a degree in the FIG. 2 position of back part 40 which will maintain that setting of the clip parts. The frictional engagement between the outside surfaces of divergent elements 25 and the inside surfaces of legs 44 in the FIG. 2 position of back part 40 is clearly depicted in FIG. 4.
In the FIG. 2 condition of the clip, the entire ear ornament clip may be contained within a rectangle of approximately 9 mm by 13 mm. In general, the periphery of the clip in the FIG. 2 condition substantially defines a general box shape or rectangular shape.
It should be noted that the second portion 43 of back part 40 is further provided with a nib 43' disposed between the legs 44. The nib 43' will butt against the lower horizontal outside edge of second portion 24 of front part 20 when back part 40 is pivoted down completely, thus serving as a stop member to restrict any further downward pivotal movement of back part 40 with respect to front part 20.
A highly important advantage afforded by the present invention which is of importance to the user can be appreciated from a comparison of FIGS. 2 and 7. In FIG. 7, the back part 11 is drawn in dotted lines in approximately the position in which it occupies when the lobe is gripped between front part 10 and back part 11. However, it will be seen that surface 16 of the curved end part 15 of back part 11 is not in horizontal alignment with the top edge 17 of front part 10. This configuration of the prior art clip does not give rise to any particular awkwardness when the ornament is large (as drawn in full line, marked 13) but could give rise to awkwardness and possible discomfort when the ornament is small (as shown in dotted line, marked 13). In FIG. 2, it will be seen that with the clip according to the present invention the two portions which will actually grip the lobe between them are in horizontal alignment, and such is clearly the optimum arrangement because the grip does not depend for effectiveness and comfort on the size of the ornament.
In particular, in FIG. 2 it can be seen that, due to the fact that first portion 41 of back part 40 is substantially curved at its uppermost portion to form a general U-shape with diverging legs, the free end 41a of first portion 41 will comprise the actual ear lobe contacting portion of back part 40. The remainder of face 42 of first portion 41 will diverge slightly away from the wearer's ear lobe. With this configuration of first portion 41, it is a simple manner, for example, for the user to remove the clip from an ear lobe gripping position (FIG. 2) by merely inserting her finger tip or fingernail into the slight space between the face 42 and her ear lobe and merely applying a pulling force to pivot the back part away from her ear lobe. Back part 40 may also be pulled rearwardly away from front part 20 by grasping the divergent leg of the U-shaped first portion 41 which is most remote from the user's ear lobe.
The resilient elements 25 can either be inherently resilient as a result of the material chosen for manufacture of the clip parts, or can be given the necessary springiness by placing elastic means between the elements if the clip parts are made of a precious metal. Such elastic means and their design and mode of use in a precious metal ear ornament clip are described and illustrated in United Kingdom patent Specification No. 1,286,245 and U.S. Pat. No. 3,654,774. Consequently, any reference to "resilient elements" in the appended claims is to be interpreted as including elements to which the necessary springiness has been imparted by such elastic means.
Although there have been described what are at present considered to be the preferred embodiments of the invention, it will be understood that various modifications may be made therein without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative, and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description.
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A two-part ear ornament clip including front and back parts which are pivotally connected together. The front and back parts are so dimensioned and connected together that, in the open condition of the clip, handling and application of the clip by the wearer to her ear lobe is greatly facilitated. The front and back parts, when disposed in their ear lobe gripping positions relative to each other, are such that the portion of the front part to which an ornament would be secured is directly opposite the portion of the back part which is in contact with the inside face of the ear lobe.
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CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This patent application is based on and entitled, under 35 USC 120, to the benefit of the filing date of U.S. provisional application No. 60/053,664 filed Jul. 24 1997 by James F. McGuckin, Jr. and entitled “Minimal Access Breast Surgery Apparatus and Method”.
FIELD OF THE INVENTION
[0002] This invention relates to surgical apparatus and methods for obtaining a subcutaneous target mass having varied shape and dimension.
BACKGROUND OF THE INVENTION AND DESCRIPTION OF THE PRIOR ART
[0003] Modern medical diagnostics increasingly rely on complex imaging technologies to identify abnormal conditions and/or masses within the human body. Such technologies as magnetic resonance imaging (MRI), ultrasonics, computerized axial tomography (CAT scan), and mammogram x-rays, aid medical personnel in the initial identification of areas within the body exhibiting potentially dangerous, abnormal biological activity. The beneficial aspect of these technologies is their ability to image biological structures interior to the human body, providing a non-invasive tool useful in facilitating preliminary diagnosis and treatment of detected anomalies.
[0004] Detected subcutaneous biological growths, masses, etc. once identified generally require complete surgical excision or at the very least an open biopsy procedure.
[0005] Small masses such as calcifications encountered in breast tissue are generally removed in their entirety. The process of excising the mass is an invasive process, performed either during exploratory surgery or utilizing specifically designed surgical apparatus. The retrieved specimen is subsequently pathologically analyzed to determine its biological properties, i.e. benign or malignant.
[0006] Several types of apparatus are known for use in removing portions of subcutaneous masses in breast tissue targeted by these imaging techniques. However, these apparatus generally either obtain only small tissue specimens from the main mass or cause significant surface scarring due to the size of the incision necessary to remove the mass with a safe resection margin.
[0007] One type of specimen retrieval is performed with needle aspiration devices. These devices have a needle with an end hole. The needle is advanced to a desired location where a sample specimen is obtained via suction. Size and quality of specimens obtained by these devices are often poor, requiring multiple sampling of each desired target mass. Moreover, tissue encountered along the path to the desired location is unavoidably removed. A hollow channel is created upon withdrawal of the device from the patient, thereby allowing “seeding” of the hollow channel removal tract with abnormal cells. Some needle systems utilize an enlarged needle end hole, creating a boring probe which obtains a greater portion of tissue. This lessens the likelihood that the specimen will be too small but increases the amount of surface scarring due to the larger size incision required.
[0008] The percutaneous incisions needed when multiple needle channels or large needle bore channels are used often result in significant scarring, dimpling and disfigurement of surface tissue.
[0009] Needle side cutting devices have a blade extending around the circumference of a hollow needle shaft. The shaft and blade are axially rotated around the skin entry site, allowing a larger overall specimen to be excised. Target tissue is sliced and a non-contiguous specimen is obtained due to the spiral blade path. While these needle side cutting devices facilitate capture of larger sample specimens, they require resection of a relatively large core of tissue between the incision and the specimen desired to be resected. Additionally, needle side cut devices result in irregularly shaped specimens and subcutaneous cavities having irregular and/or bleeding margins.
[0010] Hence, the known devices are particularly ill suited in retrieving tissue masses from the female breast, due to the interest in preserving cosmetic integrity of the surface tissue as well as the inability of the known devices to remove most masses/calcifications during a single application.
SUMMARY OF THE INVENTION
[0011] This invention provides surgical apparatus and methods where size and shape of subcutaneous tissue identified for excision is minimally dependent on dimensions of the percutaneous incision. The apparatus and methods have specific utility in breast surgery.
[0012] In one of its aspects this invention provides apparatus for excision of the subcutaneous target tissue mass through a cutaneous incision smaller than maximum transverse dimension of the tissue mass excised where the apparatus includes an axially elongated member including cutaneous tissue piercing means at one end and means connected to the elongated member and being radially expandable relative thereto for cutting a circumferential swath of radius greater than maximum transverse dimension of the elongated member and greater than maximum transverse cross-sectional dimension of the target tissue mass in order to separate the target tissue mass from surrounding tissue for excision thereof through the incision. The apparatus may further include an expandable aseptic shield concentric with the elongated member and axially slidably advanceable over the cutting means when in the radially expanded configuration, to collectibly bag the target tissue mass detached from the patient by the cut circumferential swath, for aseptic removal in an axial direction together with the elongated member through the incision resulting from entry of the cutaneous tissue piercing means.
[0013] The apparatus may yet further include a sheath which is axially slidably concentric with the elongated member and connected to first ends of the cutting means for expanding the cutting means from generally linear and axial orientation to a curved basket-like orientation by axial movement relative to the elongated member.
[0014] In yet another of its aspects the invention provides apparatus for excision of a sub-cutaneous target tissue mass through a cutaneous incision smaller than maximum transverse dimension of the tissue mass excised where the apparatus includes an axially elongated member through which cutaneous tissue piercing means may be extended to emerge at one end thereof. The apparatus further includes means insertable through the elongated member which is radially expandable relative to the elongated member for cutting a conical swath having base radius greater than maximum transverse dimension of the elongated member and greater than maximum transverse cross-sectional dimension of the target tissue mass, for separating the target tissue mass from surrounding tissue for removal thereof through the incision. In this embodiment of the invention the apparatus further preferably includes expandable aseptic shield means insertable through the elongated member and advanceable over the path of the cutting means to radially expand and collectibly bag the tissue mass detached from a patient by the conical swath cutting for aseptic removal in an axial direction through the elongated member and the incision resulting from entry of the cutaneous tissue piercing means.
[0015] In one of its aspects this invention preferably provides such apparatus having a piercing segment for penetrating a percutaneous entrance incision. The forward edge of the piercing segment preferably separates breast tissue in the path of the target tissue to be excised. The piercing segment preferably passes through the specimen to be excised, delivering an associated preferably circular array of preferably highly flexible cutting blades to the interior identified subcutaneous breast growth.
[0016] The circular array of preferably flexible cutting blades is preferably radially expanded by action of an attached actuating shaft. The blades radially expand to preferably cut by electro-cauterizing the breast tissue as they rotate around a defined periphery. The blades preferably outwardly expand to envelope the target tissue specimen and axially rotate to separate the target tissue growth from surrounding breast tissue. The target tissue growth is excised from surrounding breast tissue outisde the periphery of the circular blade path and is preferably secured by a snaring membrane placed riding over the circular array of flexible cutting blades.
[0017] The membrane is preferably secured over the blade array through an integral drawstring assembly contracting the mouth of the snaring membrane. The membrane-encased blade array is preferably drawn into a recovery sheath and compressed for aseptic removal from the excision site.
[0018] In a method aspect this invention removes subcutaneous breast growths. A percutaneous surface incision is prepared for reception of surgical apparatus. Through use of suitable medical imaging technologies, the cutting apparatus device is guided to the area of the target subcutaneous breast growth while preferably maintaining a fixed subcutaneous reference point. A circular array of blades is then preferably radially expanded, preferably forming a cutting basket having dimensions larger than the target subcutaneous breast growth. Radial expansion and rotation of the electro-cauterizing blades separates the targeted growth from surrounding tissue. A snaring membrane advances over the blade array and is secured by an integral drawstring assembly. A recovery sheath compresses the membrane, encasing the target growth as it is withdrawn from the subcutaneous breast cavity. As a result, a growth which is large relative to the entrance incision is excised. In another of its method aspects this invention provides a procedure for excision of a sub-cutaneous target tissue mass through a cutaneous incision which is smaller than maximum transverse dimension of the target tissue mass to be excised where the procedure includes an advancing tissue piercing means towards a patient to create an incision in the patient's skin, slidably advancing cutting means through the incision and into sub-cutaneous tissue until in position to radially expand and cut a circumferential swath around the target tissue mass larger than the incision, cutting a circumferential swatch around the target tissue mass thereby separating the target mass from the surrounding tissue, slidably advancing flexible aseptic containment means over the separated target tissue mass to a position of closure about the target tissue mass and withdrawing the flexible aseptic containment means, with the target tissue mass aseptically contained therewithin, through the incision. The method may further include collapsing the cutting means after cutting the swath.
[0019] In yet another of its method aspects, this invention provides a procedure for excision of sub-cutaneous target tissue mass through a cutaneous incision smaller than maximum transverse dimension of the target tissue mass to be excised where the procedure includes advancing tissue piercing means towards the patient to create an incision in the patient's skin, slidably advancing cutting means through the incision and into sub-cutaneous tissue until in position to gradually radially expand and cut a conical swath about the target tissue mass larger than the incision thereby separating the target tissue mass from the surrounding tissue, slidably advancing flexible aseptic containment means over the separated target tissue mass to a position of closure around the target tissue mass and withdrawing the flexible aseptic containment means with the target tissue mass aseptically contained therewithin through the incision. The invention in this aspect preferably further includes radially inwardly collapsing the cutting means, which is preferably wire, after cutting the conical swath and may yet further include radially inwardly cutting tissue along the base of said cone by a passage of the cutting wire therethrough and thereafter closing flexible aseptic containment means over about the periphery of the cone and the target tissue mass contained therewithin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 is a side view one embodiment of apparatus manifesting aspects of the invention with the cutting blades in radially expanded condition.
[0021] [0021]FIG. 2 is a side view of the surgical apparatus illustrated in FIG. 1 of the cutting blades in their non-expanded condition.
[0022] [0022]FIG. 3 is a front view of a modified version of the apparatus illustrated in FIGS. 1 and 2 with the cutting blades in a non-expanded condition as illustrated in FIG. 2.
[0023] [0023]FIG. 4 is a front view of a modified version of the apparatus illustrated in FIGS. 1 through 3 with the cutting blades in their radially expanded condition as illustrated generally in FIG. 1.
[0024] [0024]FIG. 5 is a broken schematic partially sectioned view of female breast tissue with the apparatus illustrated in FIGS. 1 through 4 in position within the breast in the process of removing a target tissue mass from the breast with the target tissue mass encased within an aseptic shield portion of the apparatus.
[0025] [0025]FIG. 6 is a side view of a portion of apparatus according one preferred embodiment of the invention shown in the course of practicing a preferred method aspect of the invention.
[0026] [0026]FIG. 7 is a side view of a part of the apparatus illustrated in FIG. 6 showing additional parts of one preferred apparatus embodiment of the invention in the course of practicing the inventive method.
[0027] [0027]FIG. 8 is a side view of the apparatus illustrated in FIG. 7 showing the support struts deployed.
[0028] [0028]FIG. 9 is a side view of the preferred embodiment of the apparatus showing the struts deploying about a percutaneous growth.
[0029] [0029]FIG. 10 is a side view of the preferred embodiment of the apparatus showing advancement of the cutting wire along a strut margin.
[0030] [0030]FIG. 11 is a side view of the apparatus shown in FIG. 10 with the cutting wire fully deployed.
[0031] [0031]FIG. 12 is a side view of the preferred embodiment of the apparatus depicting a new cutting wire retraction.
[0032] [0032]FIG. 13 is a side view of the preferred embodiment of the apparatus showing advancement of the bagging structure.
[0033] [0033]FIG. 14 is a side view of the preferred embodiment with tissue containment bagging completed.
[0034] [0034]FIG. 15 is a side view of the preferred embodiment of the apparatus showing the containment sheath deploying.
[0035] [0035]FIG. 16 is a side view of the preferred embodiment of the apparatus showing the containment sheath normally deployed.
[0036] [0036]FIG. 17 is an isometric view of the apparatus shown in FIG. 16.
[0037] [0037]FIG. 18 is a broken view of the tissue containment bag showning the drawstring tissue.
[0038] [0038]FIG. 19 is a side view similar to FIG. 16 but showing the containment sheath fully deployed.
[0039] [0039]FIG. 20 is a side view similar to FIG. 19 but showing the containment sheath being withdrawn.
[0040] [0040]FIG. 21 is a side view similar to FIG. 19 showing optional use of a medicament bag and a radiological marker
[0041] [0041]FIG. 22 is a side view similar to FIG. 19 showing optional use of liquid medication supported in part by the containment sheath.
[0042] [0042]FIG. 23 is an elevation of a support member.
[0043] [0043]FIG. 24 depicts the female breast and illustrated the incision resulting from practice of the method.
[0044] [0044]FIG. 25 is partial end elevation taken looking from the right in FIG. 8.
[0045] [0045]FIG. 26 is partial end elevation taken looking from the right in FIG. 10.
[0046] [0046]FIG. 27 is partial end elevation taken looking from the right in FIG. 16.
[0047] [0047]FIG. 28 is a side elevation of a second preferred embodiment of apparatus embodying the invention with hook and rod structure facilitating simultaneous performance of the cutting and bagging steps.
[0048] [0048]FIG. 29 is a partially sectioned side elevation of the embodiment of apparatus illustrated in FIG. 28 prior to deployment of the hook and rod structure facilitating simultaneous performance of the cutting and bagging steps.
[0049] [0049]FIG. 30 is a partially sectioned side elevation of the embodiment of apparatus illustrated in FIG. 28 showing deployment of the hook and rod structure facilitating simultaneous performance of the cutting and bagging steps.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] This invention provides surgical apparatus and methods for excision of percutaneous breast tissue. The apparatus has the capability to pass through an incision substantially smaller than the maximum percutaneous target specimen dimension occupying an excision site.
[0051] In one embodiment the surgical apparatus preferably cuts the target tissue with an electro-cauterizing, circular array of flexible cutting blades, preferably collecting the specimen within the periphery of an expandable blade path; thus the complete growth is preferably obtained in a single procedure. The tissue is preferably returned as a complete specimen or, alternatively, in segments within a snaring membrane. A recovery sheath is preferably positioned to further encase and compress the blade array upon contraction.
[0052] Referring to FIG. 1, the illustrated embodiment of surgical apparatus 10 includes an inner rotatable shaft 20 , a tubular recovery sheath 25 , a snaring membrane 30 , a circular array of radially flexible and expandable cutting blades generally designated 50 , a membrane drawstring 80 , a membrane mouth section 27 of recovery sheath 25 , a power source 15 and a tissue piercing member 65 .
[0053] Membrane 30 preferably has an inner surface 32 coaxially parallel with shaft 20 , and an outer surface 34 . Inner surface 32 of membrane 30 preferably slidably facingly contacts the outside surface 22 of shaft 20 . Membrane 30 is adjustably positioned in either the distal or proximate direction through the proximate end of shaft 20 .
[0054] Tubular recovery sheath 25 preferably includes a distal pleated mouth section 27 , an outer surface 45 , and an inner surface 60 facingly coaxially contacting membrane 30 . Inner surface 60 slidably engages outer surface 34 of membrane 30 . Shaft 20 defines a rotational axis 12 .
[0055] Shaft 20 rotates as denoted by arrow 12 . Rotatable shaft 20 of surgical apparatus 10 is preferably rotated manually, through mechanical hand control. However, shaft 20 may be operably linked with an electrical motor, not shown, which may be driven by power source 15 .
[0056] Circular cutting blade 50 includes individual flexible blades 55 which are preferably anchored between piercing member 65 and proximate end of shaft 20 . Blades 55 are preferably electro-cauterizing, heated by electrical power source 15 .
[0057] The materials utilized to construct surgical apparatus 10 are preferably radiopaque to be visible using modern medical imaging systems.
[0058] Referring to FIG. 2, surgical apparatus 10 is shown with individual flexible blades 55 in their non-expandable, tissue insertion orientation. In this insertion orientation the blades are parallel with and of slightly smaller diameter than tubular recovery sheath 25 . Tubular recovery sheath 25 includes a snaring membrane 30 having a mouth section 27 and a drawstring 80 , for drawing membrane 30 closed once it has been opened. Drawstring 80 is positioned along the distal margin of mouth section 27 .
[0059] Mouth section 27 of membrane 30 expands outwardly in response to pulling of a polyvinyl tab or ripcord upon reaching the excision site. The polyvinyl tab or ripcord is preferably at the end of shaft 20 to the right, which is not shown in the drawing. The polyvinyl tab or ripcord is not visible in the drawing.
[0060] Recovery sheath 25 is preferably advanced over circular array of cutting blades 50 and preferably secured in place around the cutting blades and the excised specimen by pulling the drawstring towards the proximate end of shaft 20 .
[0061] Referring now to FIG. 3, piercing segment 65 is formed to separate subcutaneous tissue in the path between the surface incision and the growth.
[0062] [0062]FIG. 3 and FIG. 4 show a modification of the embodiment of surgical apparatus 10 illustrated in FIGS. 1 and 2. In the modification illustrated in FIGS. 3 and 4, shaft 20 includes an interior channel 21 extending forwardly through the center of the cutting blade circular array 50 and connecting with piercing membrane 65 . A shaft stem section which is not shown connects to a dye port 70 in piercing member 65 for optional delivery of marking fluid to subcutaneous areas. Dye port 70 enables operators of apparatus 10 to deliver marking substances to the subcutaneous excision site. Alternatively, a titanium clip can be ejected from a clip fastening surface 75 for marking excision sites for future medical imaging analysis.
[0063] As shown in FIG. 4, the circular array 50 of cutting blades 55 expands radially upon relative moment of shaft 20 in the direction of piercing member 65 , defining a cutting orientation. Flexible cutting blades 55 are preferably electro-cauterizing, cutting as they outwardly expand and as they rotate after radially outward expansion. Upon rotation of flexible cutting blades 55 in the direction indicated by arrow A in FIG. 4, the target tissue growth is separated from the surrounding subcutaneous breast tissue and remains within the periphery of the circular blade path.
[0064] As variations, the circular array of flexible cutting blades 50 may employ radially expandable ultrasonic cutting means, referred to as “harmonic scalpels”, or laser cutting means.
[0065] The method of excising subcutaneous breast target tissue growths is shown in FIG. 5. In FIG. 5 the edges of a surgical site where a growth has been removed is indicated as 100 ; removal of the growth has created subcutaneous cavity 105 . As shown, subcutaneous cavity 105 is separated from a surface incision 126 by an excision distance 95 .
[0066] In preparation for removing the subcutaneous breast tissue growth, percutaneous tissue is cut to produce an incision 126 . A piercing member 65 of surgical apparatus 10 is placed at incision 126 . An excision path is created by forcing piercing member 65 through the subcutaneous breast tissue between the percutaneous incision 126 and the identified target tissue growth. The target tissue growth is the desired excision site which is visualized via a medical imaging system such as ultrasound or mammography. The tip of surgical apparatus 10 is advanced until the piercing segment passes through the growth to be excised.
[0067] Once apparatus 10 is properly positioned relative to the target tissue mass as indicated by the medical imaging system, the proximate end of shaft 20 is urged towards piercing member 65 . Flexible cutting blades 55 radially expand to define subcutaneous margin 100 . The array of flexible cutting blades 50 is then rotated about the shaft axis as indicated by arrow 12 , separating the target tissue growth along margin 100 .
[0068] Membrane 30 is then advanced over the circular array of cutting blades 50 and secured by pulling integral drawstring 80 to the right in FIG. 5 towards the end of shaft 20 . Drawstring 80 secures the distal margin of membrane 30 . The mouth 27 of sheath 25 is expanded by the polyvinyl pull tab when drawn towards the end of shaft 20 .
[0069] Circular array of cutting blades 55 , now encased by membrane 30 , is drawn into the mouth of snaring sheath 25 and removed from subcutaneous cavity 105 .
[0070] In the preferred embodiment shown in FIG. 6, a plurality of guide struts generally designated 150 are advanced through a skin surface incision 126 and past a target tissue mass 115 via a tubular housing defining an extrication channel 26 . As shown in FIGS 7 and 8 , guide struts 150 are inserted through surface incision 126 and moved to a position to define a conically shaped desired excision margin 100 respecting the target tissue mass 115 , shown in FIG. 11. As shown in FIGS. 8 through 10, the extension and configuration of struts 150 from surface incision 126 past target mass 115 creates a gradually expanding subcutaneous retrieval path referred to as a conical penumbra 95 .
[0071] As shown in FIGS. 11 through 13, an electro-cauterizing cutting snare 155 is advanced along guide struts 150 , creating a conically shaped excision margin.
[0072] Referring to FIG. 14, the cutting snare 155 is advanced beyond the length of the guide struts 150 to where cutting snare 155 is drawn closed by pulling an integral drawstring 160 towards the exterior of the skin. As shown in FIGS. 15 through 17, mouth 27 of sheath 25 is advanced along the defined extrication channel 26 and expanded by pulling the polyvinyl pull tab which is not shown. As shown in FIGS. 18 through 24, guide struts 150 are enveloped by snaring sheath 25 and may be removed from subcutaneous cavity through extrication channel 26 .
[0073] In one preferred practice of the invention as depicted in FIGS. 6 through 27 and using the apparatus shown therein, apparatus 200 includes a support conduit designated generally 202 and axially elongating skin cutting means 204 having a cutting blade 205 which is insertable through support conduit 202 as illustrated generally in FIG. 6. Skin cutting means 204 and particularly cutting blade 205 to make a suitable incision in the skin, preferably in the human breast designated generally 246 in FIG. 24 where the skin is designated 224 in the drawing figures including FIG. 6 and FIG. 24. The incision is made to provide access to a target tissue mass designated generally 228 in the drawings which has been previously identified preferably using x-ray mammographic techniques as being dangerous and hence to be removed.
[0074] Once a skin incision, designated generally 248 in the drawings, has been made by skin cutting means 204 and appropriate use of cutting blade 205 thereof, skin cutting means 204 is preferably withdrawn axially through support conduit 202 , moving to the left in FIG. 6, and support means designated generally 207 and having a plurality of support members designated generally 206 is inserted axially through support conduit 202 and into the sub-cutaneous tissue 226 of the breast as indicated generally in FIG. 7, with the direction of travel of support means 207 indicated generally by arrow A in FIG. 7.
[0075] As support members 206 of support means 207 are inserted into the sub-cutaneous tissue 226 , support members expand 206 radially due to influence of resilient spring means 210 , illustrated in dotted lines in FIG. 8 and forming a portion of support means 207 to a position where support members 206 define a conical penumbra enveloping target tissue mass 228 . The conical penumbra 208 defines planes of incision for removal of target tissue mass 228 and a medically advisable amount of surrounding sub-cutaneous healthy tissue 226 .
[0076] As support members 206 radially diverge one from another due to the influence of resilient spring means 210 , remote tips 209 of support members 206 define a circle which in turn defines the base of conical penumbra 208 . Remaining, proximate ends of support members 206 are pivotally connected to a supporting shaft, not numbered in the drawings, for pivoting rotation thereabout in response to spring 210 .
[0077] Once support members 206 have been deployed, into the position illustrated in FIG. 8, the target tissue mass is well within the conical penumbra defined by support members 206 .
[0078] A pair of tissue cutting wire loops 214 are positioned about the bases of support members 206 , as illustrated generally in FIG. 9, and are supported by and emerge from respective support catheters 212 , also illustrated in FIG. 9. Support catheters 212 are sufficiently rigid that when force is applied in the axial direction to support catheters 212 is indicated by arrows B and B′ in FIG. 9, support catheters 212 move to the right in FIG. 9 advancing tissue cutting wire loops 214 along the outer periphery of support members 204 as depicted generally in FIG. 10.
[0079] As support catheters 212 are moved to the right in FIGS. 9 and 10, additional lengths of tissue cutting wires 214 is supplied through support catheters 212 so that tissue cutting wires 214 , which are in the form of loops about the exterior surfaces of support members 206 as illustrated in FIG. 10, can enlarge as the circumference of the conical penumbra, measured about the slant surface of the conical penumbra defined by support members 206 as illustrated in FIG. 10, increases.
[0080] Support catheters 212 are urged to the right in FIG. 10 until tissue cutting wire loops 214 pass the remote tips 209 of support members 206 and define a pair of essentially coincident and in any event concentric circles forming the base of conical penumbra 208 .
[0081] Once tissue cutting wire loops 214 have reached this position due to movement of support catheters 212 , the wire forming tissue cutting wire loops 214 are drawn to the left, through respective support catheters 212 . This causes the respective tissue cutting wire loops 214 each to cinch together as the wires are withdrawn as indicated generally by arrows C, C′ in FIG. 11. As the tissue cutting wires are drawn to the left in FIG. 11 through respective support catheters 212 , the wire loops each cinch together thereby cutting circular incisions through the sub-cutaneous tissue; this action is illustrated generally in FIG. 11 where the respective tissue cutting wire loops are shown partially, but not completely, cinched. Two wire loops are preferable, for symmetrical application of force.
[0082] Once tissue cutting wire loops 214 have been completely cinched and the wires withdrawn to the position illustrated in FIG. 12 by continually drawing the respective tissue cutting wires 214 in the directions indicated by arrows D, D′ in FIG. 12, the conical penumbra 208 defines planes of incision created by action of tissue cutting wire loops 214 where those planes of incision are shown in dotted lines in FIG. 12. Note that two dotted lines are shown at the extreme right of FIG. 12 to indicate that two circular planar incisions created by action of respective tissue cutting wire loops 214 . Desirably, these two circular planar incisions are essentially congruent one with another.
[0083] Once tissue cutting wire loops 214 have been completely withdrawn into the position illustrated in FIG. 12, a suitable tissue containment bag structure 216 is advanced outwardly of support conduit 202 , around the outer periphery of support means 207 and particularly support members 206 . Tissue containment bag 216 preferably has a pair of drawstrings 218 , which may be metal, suture material, suitable plastic monofilaments and the like, which are sewn or threaded into tissue containment bag 216 proximate the vertical right-hand margin thereof appearing in FIG. 13. Drawstrings 218 have extremity portions 219 illustrated in FIG. 13.
[0084] Once tissue containment bag 216 has been advanced so that its margin 217 has traveled inwardly with respect to the breast past the remote tips 209 of members 206 , to the position generally corresponding to the base of conical penumbra 208 , drawstring extremities 219 are pulled to the right in FIGS. 13 and 14, thereby causing looped drawstrings 218 , 218 'to close margin 217 of bag 216 , causing margin 217 to circularly gather as shown in FIG. 14.
[0085] Once margin 217 of bag 216 has been circularly gathered thereby effectively closing bag 216 about the target tissue mass 228 of interest, an expandable sheath 230 is advanced through the interior of support conduit 202 about tissue containment bag 216 with expandable sheath 230 moving in the direction indicated by arrow F in FIG. 15. Expandable sheath 230 has a pleated expandable portion 231 , which is resilient and seeks to expand radially outwardly to relieve internal stresses such that upon expandable portion 231 reaching terminus 203 of support conduit 202 which is within sub-cutaneous tissue 226 , expandable portion 231 expands radially into the configuration illustrated generally in FIG. 16. Expandable portion 231 of sheath 230 is preferably pleated, as depicted in FIG. 17.
[0086] Expandable sheath 230 and particularly expandable portion 231 thereof provides support in the form of radially inwardly directed force on tissue containment bag 216 as bag 216 with target tissue mass 228 enveloped therein is pulled to the left in FIGS. 16, 19 and 20 as indicated generally by arrows G in FIG. 19 and arrow H in FIG. 20. The radially inward force provided on tissue containment bag 216 and target tissue mass 228 contained therein by expandable sheath 230 , as tissue containment bag 216 is pulled to the left in FIG. 19, compresses tissue mass 228 into a smaller volume and essentially squashes tissue mass 228 into a longitudinally elongated form for passage through support conduit 202 . Application of the radial force to tissue mass 228 reduces the transverse cross-sectional dimension of tissue mass 228 to at least the diameter of support conduit 202 as tissue containment bag 216 is drawn through the funnel-shaped expandable portion 231 of sheath 230 and into the interior of support conduit 202 . Once bag 216 and tissue mass 228 contained therein have been removed from the sub-cutaneous tissue, expandable sheath 230 may be removed by pulling it in the direction indicated by arrow H in FIG. 20.
[0087] Optionally, while expandable sheath 230 is in position and perhaps only part way removed from the resected area of interest, a medicament bag 232 may be inserted into the resected area through the interior of support conduit 202 and through expandable sheath 230 , as indicated in FIG. 21. This may provide means for supplying radioactive gas to provide radiation therapy to the resected area. Additionally, a radiographic marker depicted as 236 may be implanted into the resected area of interest, using the balloon or otherwise while expandable sheath 230 remains in the area of the resection. As an additional option while expandable sheath remains in position thereby maintaining a void in the resected area of the sub-cutaneous tissue, liquid medication indicated schematically as 234 in FIG. 22 may be supplied to the resected area. In such case expandable sheath maintaining the resected tissue in a spaced-apart condition facilitates application of the liquid medication to all parts of the resected volume.
[0088] Utilizing the method and apparatus as described hereinabove results in a small, tunnel like incision approaching the skin of the breast with a larger, resected mass being removed therefrom; the resulting internal incision is depicted 244 in FIG. 24.
[0089] Support members 206 preferably have metallic tips to provide radiopaque characteristics as indicated by 230 in FIG. 23 and may also have metallic or other radiopaque marker bands indicated as 248 in FIG. 23. Central portions 242 of support members 206 are preferably radiolucent as indicated by the stippling in FIG. 23.
[0090] In FIGS. 28 thorugh 30 the curring wire and bag are connected by hook and rod structure as illustrated.
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A surgical apparatus for cutting a tissue mass comprising an elongated housing having a distal portion, a rotatable shaft positioned in the elongated housing, and a plurality of flexible electrocautery cutting blades extending from the housing, wherein the plurality of cutting blades are radially expandable from a first position defining a first diameter to a second larger diameter and the blades are rotatable and transmit electrical energy to cut the tissue mass.
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BACKGROUND OF THE DISCLOSURE
1. Field of the Invention
The present invention is directed to a device for generating radiant energy. More particularly, the present invention is directed to a device for generating radiant energy emitted by a rare earth metal oxide or rare earth metal halide in electrical communication with, and disposed between, a first and second electrode.
2. Description of the Prior Art
The development of light emitting devices is a major activity in the semiconductor arts. This is to be expected insofar as information propagation by means of harnessing light waves so generated represents a potential source of information transmission. Transmission by light waves removes speed and power restrictions associated with electrical wire transmission. Thus, the development of efficient light emitting semiconductor structures represents an attractive and burgeoning area of technical development.
Currently, the most efficient light-emitting semiconductor materials are direct-gap compound semiconductors e.g. III-V and II-VI materials.
However, severe processing constraints associated with these materials have prevented the development of very large scale integrated (VLSI) circuits utilizing these materials. Thus, attention has been directed to modifications of silicon-based semiconductors insofar as silicon semiconductors are the best developed and understood semiconductor materials. Unfortunately, silicon is an indirect bandgap semiconductor. As such, it exhibits extremely poor luminescence, whether electrically-pumped or optically-pumped.
In view of the above remarks recent research has focused on the manufacture of optoelectronic integrated circuits (OEICs) on silicon. This research has attempted to develop chip-to-chip interconnects, parallel processing and the integration of photonics on silicon chips. The integration of photonics on silicon chips require operation of a silicon-based light source at 1.54 microns. That wavelength corresponds to an absorption minimum in silica-based optical fibers. This, in turn, has focused upon the utilization of erbium-doped silica fiber amplifiers.
This latter development is the result of the fact that erbium atoms have a strong absorption band centered around 0.98 microns, corresponding to a 4 I 15/2 to 4 I 11/2 (4f 11 ) transition and a strong emission spectrum centered around 1.54 microns, corresponding to a 4 I 13/2 to 4 I 15/2 (4f 11 ) inner atomic transition. When Er-doped silica fiber is photopumped by semiconductor lasers emitting at 0.98 microns, the gain spectrum peaks around 1.54 microns. Thus, an optical signal, centered around 1.54 microns, passing through an Er-doped silica photopumped fiber would be greatly amplified. In fact, if sufficient population inversion were obtained, and a Fabry-Perot cavity created, an Er-doped fiber laser would be obtained.
In view of these scientific facts much activity has focused upon doping of silicon with erbium to effectuate the aforementioned results. Franzo et al., Applied Physics Letters, 64, 2235, (1994) and Michel et al. Applied Physics Letters, 64, 2842 (1994) describe ion implantation of erbium into silicon. Serna et al., J. ADpl. Phys., 75, 2644 (1994) sets forth Er incorporation during molecular beam epitoxy growth. Michel et al., J. A)pl. Phys., 70, 2672 (1991) describes the coimplantation of oxygen, carbon, nitrogen and fluorine with erbium into silicon.
Surprisingly, these studies emphasize that luminescence intensity depends strongly on the concentration of other impurities. Indeed, these studies indicate that the presence of oxygen is imperative for light emission with acceptable quantum efficiency. Alder et al. Appl. Phys. Letters, 61, 2180 (1992) found that extended X-ray absorption fine-structure (EXAFS) measurements from erbium implanted by the Czochralski (CZ) method and by the float-zone (FZ) technique produce dramatically different local structures around Er with respect to coordination number, type of atom and bond length. These studies show that the first coordination shell in Er: FZ Si closely resemble the 12 Si atoms in ErSi 2 , whereas the first shell around Er in the CZ technique resembles the 6 oxygen atoms in Er 2 O 3 . This explains how the local chemical environment around Er determines its optical activity, i.e. Er in Si effectively acts as a microscopic getter, reacting in with Si only when either the amount of or accessability to oxygen is limited. Since the sixfold oxygen coordination to erbium cannot be centrosymmetric, the crystal field of the Si host lattice breaks inversion symmetry and mixes states of opposite parity, allowing the 4 I 13/2 to 4 I 15/2 transition (which is dipole forbidden in the free atom) to take place. Because the magnitude of the crystal-field splitting, which determines the transition probability, depends on the symmetry and chemical nature of the ligands bound to Er, the two different local environments in CZ and FZ lead to very different degrees of optical activity.
The prior art, i.e. Ennan, et al, Appl. Phys. Letters, 46, 381 (1985), reports photoluminescence and electroluminescence from Er-doped Si. the aforementioned Franzo et al. and Michel et al. Applied Physics Letters articles report the formation of light emitting diodes (LEDs) fabricated in silicon p + -n + diodes with Er and O co-doping at the metallurgical junction region. Kimura et al., Appl. Phys. Letters, 65, 983 (1994) reports electrochemical Er doping of porous Si and the room temperature luminescence of the so-doped silicon at 1.54 microns.
In spite of the above discussed activities, the introduction of erbium into silica has not produced the requisite quantum efficiency necessary to commercialize this advance. The above discussed scientific developments indicate that erbium-oxygen complexes are crucial to intra-shell luminescence. However, carrier transfer to these complexes from a host silicon lattice remains unsolved. Therefore, there is a continuing need in the art for further development of erbium and other rare earth metal modified silicon semiconductors to provide light-emitting devices.
BRIEF SUMMARY OF THE INVENTION
A solution to the problem of poor quantum efficiency has now been discovered which permits silicon semiconductor materials to be used, in conjunction with rare earth metal compounds, to produce effective light-emitting semiconductor materials. This discovery overcomes the inherent inefficiencies associated with rare earth metal implantation in silicon. Instead of rare earth metal doping of silicon, a new device has been devised which utilizes rare earth metals in conjunction with a silicon chip to produce radiant energy more efficiently than the methods utilized in the prior art.
In accordance with the present invention a device for generating radiant energy is provided which includes a first electrode and a second electrode, spaced apart from the first electrode. A material, selected from the group consisting of rare earth metal oxides and rare earth metal halides, is disposed between and in electrical communication with the first and second electrodes.
In further accordance with the present invention a field effect transistor is disclosed. The field effect transistor includes a source region and a drain region formed in a first semiconductor material. A channel region is thus formed between the source region and the drain region on the surface of the first semiconductor material. A first electrode is electrically connected to the source region and a second electrode is connected to the drain region. A second material, a rare earth metal oxide or a rare earth metal halide, is disposed above the. surface between the first and second electrodes together with a low interface-state oxide and is in electrical communication with them. A gate electrode is disposed over the second material.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be better understood with reference to the accompanying drawing which is a schematic representation of a light-emitting device in accordance with the present invention.
DETAILED DESCRIPTION
The light emitting device of the present invention is generally depicted at 1 region of the drawing. The device 1 includes a substrate 2 which includes a p-doped silicon region 9. Two donor doped silicon portions of substrate 2 is n-type, denoted at 4 and 6, are connected to first and second electrodes 3 and 5, respectively. A channel region generally encompasses the region in the substrate 2 between the n-type electrodes 4 and 6 and is defined by electron inversion due to presence of bias at the gate electrode 12. The channel region 7 broadly occupies an area bordered by the bottom an insulator 8, the dotted line and inner edges of regions 4 and 6 as illustrated in the drawing. The just mentioned insulator 8 is disposed over the channel region 7 but also extends over portions of the donor doped first and second electrodes 4 and 6. In a preferred embodiment the insulating layer 8 is silica.
A second material 10, the first material being the semiconductor material of a rare earth metal oxide or a rare earth metal halide, is disposed atop the insulating layer 8. Preferably, the rare earth metal of the earth metal oxide or rare earth metal halide compound is erbium, samarium, europium, terbium, ytterbium, neodymium or gadolinium. Of the rare earth metals utilized in the rare earth metal compound which constitutes second material 10, erbium is most preferred.
In the preferred embodiment wherein the second material 10 is a rare earth metal halide, the halogen of that compound is preferably fluorine, chlorine or iodine. Of these, fluorine is more preferred.
In a particularly preferred embodiment of the second material 10 that material is erbium oxide having the structural formula Er 2 O 3 or erbium fluoride having the structural ErF 3 .
The device 1 includes a gate electrodes 12 and 14 in electrical communication with electrical conducts 15 and 18 respectively. The material of construction of gate electrode 12 is restricted to a material which is transparent at the wave frequency at which the rare earth metal generates radiant energy, as discussed below. Thus, in a preferred embodiment, wherein the rare earth metal of the second material 10 is erbium, the material of construction of the gate electrode 12 is cadmium tin oxide (CTO) or indium tin oxide (ITO). CTQ or ITO is transparent at a wavelength of 1.54 microns. The second gate electrode 14, not in the path of the emitted light from material 10, need not be so limited. Thus, other materials, in addition to cadmium tin oxide, normally used in gate electrodes are usable as the second gate electrode 14. For example, aluminum, a preferred material of construction of gate electrodes, is a preferred material of construction of gate electrode 14.
The device 1, in a preferred embodiment, acts as a field effect transistor. Thus, the transistor includes the components mentioned above in the discussion of device 1. In the parlance of field effect transistors, the donor doped portion 4 represents a source region while the donor doped portion 6 of substrate 2 is the drain region. The first electrode 3 is electrical connected to the source region 4 and the second electrode 5 is electrically connected to the drain region 6.
The light emitting device 1 operates upon imposition of a voltage between the first and second electrodes 3 and 5. A second voltage is imposed across the substrate 2 by the imposition of a voltage difference at 16 and 18 which are in electrical communication with gate electrodes 12 and 14, respectively. This, in turn, drives the device, which may be said to be a metal oxide semiconductor field effect transistor, into breakdown, with hot electrons being injected from the valence band of the positively doped silicon region 9 into the second material 10 layer. These impact-ionized carriers cause excitement of rare earth metal ions from a ground state to an excited state, whereupon light is emitted. For example, in the preferred embodiment wherein the material 10 is Er 2 O 3 , Er +++ ions are excited from the ground state 4 I 15/2 to either of the excited states, viz., the 4 I 13/2 state or the 4 I 11/2 state. In the latter case, the Er +++ ions relax non-radioactively into the 4 I 13/2 state and then emit light at a wavelength of 1.54 microns during the transition from the 4 I 13/2 to the 4 I 15/2 state.
As emphasized above, the gate electrode 12 must be fabricated of a transparent metallic layer. Thus, cadmium tin oxide, which is transparent at a wavelength of 1.54 microns, is well suited for use as the gate electrode 12 when the rare earth metal of the rare earth compound of material 10 is erbium. Other metallic or metal-like materials, such as polysilicon, epitaxially-deposited silicon or conducting oxides such as indium tin oxide, may also be employed as the gate electrode 10 consistent with the use of a rare earth metal that radiates energy at a wavelength at which these materials are transparent.
A preferred application of the device 1 is in the fabrication of a dielectric waveguide for guiding light, emitted from the electroluminescent device to a light conduit, e.g., an optical fiber.
The above preferred embodiments are given to illustrate the scope and spirit of the present invention. These embodiments will make apparent, to those skilled in the art, other embodiments and examples. These other embodiments and examples are within the contemplation of the present invention. Therefore, the present invention should be limited only by the appended claims.
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A device for generating radiant energy comprising a first electrode, a second electrode spaced apart from said first electrode, a material disposed between and in electrical communication with first and second electrodes, which emits radiant energy upon activation. This material is a rare earth metal oxide or a rare earth metal halide.
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BACKGROUND OF THE INVENTION
The present invention relates to a microcomputer, such as a single-chip microcomputer with a built-in read-only memory.
A conventional single-chip microcomputer comprises a central processing unit (CPU) including a control unit, an operation unit and a register section, a memory device including a read-only memory (ROM) incapable of re-writing (reprogramming) and a random access memory (RAM) capable of writing and reading, and an input/output (I/O) device, which are all built in an IC chip.
The data processing speed of a microcomputer of this kind is increased year by year, and the minimum instruction execution time is about 1 microsecond in a 4-bit microcomputer, and about 500 nanoseconds in an 8-bit microcomputer. The circuit within a microcomputer is becoming more and more complicated, and accordingly, testing the functioning of the circuit is becoming more and more difficult.
In a conventional test, an external memory in which a test program has been written, is connected to the microcomputer through various terminals. The test mode is set using a control terminal. In this mode, address signals are outputted through input/output terminals and supplied to the external memory, and the test program is read out of the external memory and inputted through other input/output terminals to the microcomputer, and is executed. The test of the internal logic circuits is thereby accomplished.
The above-described microcomputer has the following problems.
When a function test of the microcomputer is conducted, time for outputting the address signals to access the external memory, and time for reading the test program out of the external memory are necessary, so that the execution of the test program is slower than the execution of the instructions of the internal ROM. As a result, it is impossible or very difficult to conduct the test under the same condition as where the internal ROM is operated at the maximum instruction execution speed. The reliability of the test is therefore not sufficient. Moreover, a large number of terminals are required for input/output of the addresses and the instructions. Another shortcoming of the conventional microcomputer is the incapacity of programming after manufacture. To generalize, the conventional microcomputer is not versatile enough for certain applications.
SUMMARY OF THE INVENTION
An object of the invention is to provide a microcomputer whose logic circuits can be tested at a high execution speed and which does not need to have a large number of terminals for the test.
Another object of the invention is to provide a microcomputer having an improved versatility.
A further object of the invention is to provide a method for testing at the same speed as the execution of the program stored in the internal ROM.
According to the invention, there is provided a microcomputer selectively operable in a first mode or a second mode, comprising
a first read-only memory for storing a first program to be executed in the first mode,
a second, programmable read-only memory for storing a second program to be executed in the second mode,
input means for inputting the second program to be written in the second read-only memory,
execution means for executing the first program or the second program, and
mode control means responsive to a mode selection signal for enabling execution of the first program when the mode selection signal designates the first mode and for enabling writing and execution of the second program when the mode selection signal designates the second mode.
With the arrangement described above, the programmable ROM may be used to store a test program. In such a case, when the second mode is selected, instructions for the test program are written in the programmable ROM, and are then read out and executed at the same speed as in the first mode. The various problems which were previously described are thereby solved.
As an alterative to the test program, an application program may be stored in the programmable ROM. Such an application program may be an addition to the application program stored in the ROM, in such a case, the additional application program is stored in the programmable ROM to provide an optional function thereby meeting same line the special requirements for a particular use.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a block diagram showing an embodiment of a microcomputer according to the present invention;
FIG. 2 is a block diagram showing an example of the serial-parallel converter of FIG. 1;
FIG. 3 is a block diagram showing an example of an operation mode control circuit of FIG. 1;
FIG. 4 is a time chart showing various signals and time periods allotted for the respective operations;
FIG. 5 is a flow chart showing an operation performed under control of a program stored in the ROM of FIG. 1; and
FIG. 6 is a block diagram showing another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A microcomputer of an embodiment shown in FIG. 1 is a single-chip microcomputer 1 and comprises a mask ROM 16 which is programmed during fabrication. The programs stored in the mask ROM 16 may include an ordinary application program of a type provided for a microcomputer of this particular design.
There is also provided a programmable ROM (PROM) 17 which can be programmed after fabrication. The PROM 17 is preferably an electrically erasable PROM (EEPROM) which can be programmed and erased by application of a voltage, e.g., 21V higher than the normal operating voltage, e.g., 5V. However, other types of PROM's, such as an EPROM may also be used. The PROM may be used to store a test program for testing the logical circuits of the microcomputer or an optional application program, which may be one used in conjunction with the application program stored in the mask ROM 16. For example, if the application program stored in the ROM 16 is a standard program for controlling a VTR (video tape recorder), the program stored in the PROM 17 may be a program for the additional functions of VTR control which may differ from one user (VTR manufacturer) to another, or from one type of VTR to another.
The address input terminals of the mask ROM 16 and the PROM 17 are connected through an address bus 5 to a program counter 12, which contains the address of the next instruction to be fetched and executed. The address contained in the program counter is automatically incremented each time an instruction is fetched.
The data output terminals of the mask ROM 16 and the data input/output terminals of the PROM 17 are connected to a data bus 16, which in turn is connected to an instruction register 10. An instruction fetched from the ROM 16 or the PROM 17 is temporarily held in the instruction register 10. An instruction decoder 11 decodes the instruction held in the instruction register 10 and produces control signals, not shown, to execute the instruction. Although there are also provided a RAM (random access memory) used as a data memory, an ALU (arithmetic logic unit) and registers which are essential for operation of a microcomputer, these are not illustrated since they are well-known and are not features of the invention.
An input/output terminal 4 is provided for input of a program (e.g., a test program) to be stored in the PROM 17. In the illustrated embodiment, bits forming instructions of the program are serially inputted into the chip 1 through the terminal 4. A serial-parallel converter 15 converts the serially transmitted bits into a set of parallel bits forming an instruction. An example of the serial-parallel converter 1b is shown in FIG. 2. As illustrated, the serial-parallel converter 1b comprises a shift register 15a and a control circuit 15b. The shift register 15a, under control of the control circuit 15b, converts the serially transmitted bits into parallel bits. In the example shown, the data bus 18 comprises 8 lines, and the shift register 15a therefore has 8 stages respectively connected to the 8 lines of the data bus 18. Each time 8 bits of information forming an instruction have been serially inputted into the shift register 15a and held at the respective stages of the shift register 15a, the contents at the respective stages are outputted onto the data bus 16. Simultaneously, a timing signal ES is produced from the shift register. This timing signal ES is used to make the PROM 17, etc. ready for writing the instruction.
The shift register 15a and the control circuit 15b are also used to convert the parallel data on the data bus 18 into serial data and to output the serial data through the input/output terminal 4. For instance, during execution of a test program, data indicating the result of the test may be outputted through the input/output terminal 4. This allows the result of the test to be judged outside the microcomputer.
An operation mode controller 14, as shown in FIG. 1 is connected to receive a mode selection signal MS inputted through a mode selection terminal 3. The mode selection signal MS is at "0" when a first or an ordinary mode is selected, and is at "1" when a second or a special mode is selected. The operation mode control circuit 14 delivers the mode selection signal MS to various circuits within the microcomputer, including the ROM 16, the PROM 17 and the program counter 12 to cause them to operate in the ordinary mode or the special mode.
When the mode selection signal MS rises to "1" the program counter 12 is initialized, e.g., set to have the address value of zero, and the PROM 17 is made ready for operation.
The operation mode control circuit 14 also provides control signals for use in operation in the special mode. For this purpose, as shown in FIG. 3, it includes AND gates 14a through 14d and a sequence control circuit 14e. Each of the AND gates 14a through 14d receives at its one input terminal the mode selection signal MS and receives at another input terminal a respective one of control signals TCa through TCd supplied from the sequence control circuit 14e and produces a respective one of control signals XCa through XCd. The sequence control circuit 14e is responsive to the mode selection signal MS rising to "1" for beginning, upon confirmation of the state that the special mode may be entered, to cyclically produce the signals TCa through TCc as shown in FIG. 4. The signal TCa gives the timing for reading the serially-transmitted data into the shift register 15a. The signal TCb is produced when the signal ES is produced, and causes the data in the shift register 15a to be written into the PROM 17. For this to be realized, the data in the shift register 15a is transferred onto the data bus 18. Then, the data on the data bus 16 is written into the appropriate location now being addressed by the program counter 12. During such writing a high voltage, e.g., 21V, is applied to the PROM 17 for a period of several tenths of a msec. Such a voltage may be supplied from the outside of the chip or may be generated inside the chip.
The signal TCc is for incrementing the program counter 12 upon completion of writing each instruction in the PROM 17. As the above-described steps are repeated the instructions of the program are successively written in the PROM 17.
In the illustrated embodiment, the program to be written in the PROM 17 is made to consist of less than 100 steps, and the program counter 12 is arranged to produce a signal EP when its content (the address value) becomes 100 to indicate the end of programming.
When the signal EP is produced, the sequence control circuit 14e causes to produce the signals TCa through TCc and instead begins to produce the signals TCd. When this signal TCd is produced the program stored in the PROM 17 is executed.
The manner of execution of the program in the PROM 17, as shown in FIG. 1 is similar to that of the execution of the program in the ROM 16. That is, the instructions of the program are successively fetched and executed. More specifically, the instruction at the location of the PROM 17 now being designated by the program counter 12 is read out onto the data bus 18, and is latched by the instruction register 10. The instruction decoder 11 decodes the instruction latched in the instruction register 10 and supplies various control signals to various parts of the microcomputer to execute the instruction. When the execution of one instruction is completed, the next address now being designated by the program counter 12 (whose content was incremented upon fetching of the instruction during the preceding cycle) is fetched and then executed. In this way, the instructions of the program stored in the PROM 17 are executed in sequence.
The program stored in the PROM 17 may be executed more than once. When the program already stored in the PROM 17 is to be executed, the step of programming is omitted and the execution of the program in the PROM 17 is immediately started upon entry into the special mode.
When the mode selection signal MS is at "0", the operation mode control circuit 14 permits the program stored in the ROM 16 to be executed. The execution of the program stored in the ROM 16 may be achieved in the following manner.
The instruction at the location of the ROM 16 now being designated by the program counter 12 is read out onto the data bus 18, and is latched by the instruction register 10. The instruction decoder 11 decodes the instruction latched in the instruction register 10 and supplies various control signals to various parts of the microcomputer to execute the instruction. When the execution of one instruction is completed, the next address now being designated by the program counter 12 (whose content was incremented upon fetching of the instruction during the preceding cycle) is fetched and then executed. In this way, the instructions of the program stored in the ROM 16 are executed in sequence. During such an operation, the PROM 17 may be used as a data memory for back-up.
A timing control circuit 13 receives clock pulses CP through a clock pulse terminal 2 and produces timing signals and supplies them to various circuits within the chip 1. In FIG. 1, the operation mode control circuit 14 alone is shown to be connected to receive the signals from the timing control circuit 13, but this is exemplary and does not mean that other circuits are not connected to the timing control circuit 13.
As was described earlier, the PROM 17 may be used to store various program, such as a test program or an optional application program.
The test may be conducted by the manufacturer of the microcomputer. After the test, the test program may be erased. If an EEPROM is used for the PROM 17, the erasure can be achieved automatically. After the erasure, the PROM 17 is ready for a further programming by the manufacture or by the user. The user may conduct its own test (acceptance test) using the PROM 17 to store the user's own test program. An optional application program may thereafter be written in the PROM 17. If the test by the user is not needed, the optional application program may be written by the manufacturer before delivery to the user.
The microcomputer described above has the advantage of improved versatility with a minimum number of terminals. Moreover, if the microcomputer is used for testing, there is an additional advantage that the instruction of the test program is made to be executed at the same speed as the ordinary program. This is because the time required for accessing an external memory, which was necessary with the conventional system, is not necessary.
In the embodiment described, the control for programming PROM 17 and executing the program within the PROM 17 is made by the sequence control circuit 14e. Alternatively, such control including control of the serial-parallel converter 15 can be made by a program stored in the ROM 16. FIG. 5 shows an operation performed in such a case.
As illustrated, when the mode selection signal MS rises to "1" and the special mode is permitted entry (101), then it is judged whether it is necessary to program the PROM 17 because the desired program has not been written in, or execution of the program may be started immediately because the desired program has already been written in (102). If it is necessary to program, then the programming is conducted (103). That is, the serial data (instruction) is inputted into the shift register 15a (103a), and the parallel data is written into the location of the PROM 17 now being addressed by the program counter 12 (103b). Then, the program counter 12 is incremented (103c). The steps 103a through 103c are repeated until the program counter reaches "100" (103d). Then, the program stored in the PROM 17 is executed (104). If, at the step 102, the PROM 17 is already programmed, the execution of the program in the PROM 17 is immediately started (104). Operations for the execution of the program stored in the PROM 17 are similar to those already described in connection with the embodiment of FIG. 1.
In the embodiment described, a mode selection signal MS consisting of a single bit is supplied through the terminal 3. But the mode selection signal may be supplied through the input/output terminal 4 and may consist of a plurality of bits, e.g., 8 bits, and it may be so arranged that it is judged by means of a program stored in the ROM 16 at the time of the power-on of the microcomputer, whether the data supplied through the input/output terminal 4 is of a specific code, and if it is found to be the specific code, a single-bit signal is set at "1": otherwise the signal is at "0". This signal may be used in place of the mode selection signal MS of the abovedescribed embodiment.
In the embodiment of FIG. 1, the data to be written in the PROM 17 is serially inputted through a terminal 4. Alternatively, there may be provided terminals for parallel input. FIG. 6 shows an example of such an arrangement. As illustrated, there are provided a plurality of (e.g., eight) terminals 19 respectively connected to the lines of the data bus 18. The serial-parallel converter 14 of FIG. 1 is eliminated. This embodiment has an advantage over the embodiment of FIG. 1 in that the time required for programming the PROM 17 is shorter. Although the number of terminals is greater than in the embodiment of FIG. 1, it is smaller than the prior art where the address must be supplied from the microcomputer to the external memory.
As has been described, the invention provides a microcomputer having a PROM in addition to a ROM. The PROM may for example be used to store a test program or an optional application program. Accordingly, the versatility of the microcomputer is improved. Moreover, when the PROM is used to store a test program, there is an additional advantage that the instructions of the test program can be made to be executed at the same speed as the instructions of an ordinary program stored in the ROM. The reliability of the test is therefore improved.
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A microcomputer selectively operable in a first mode or a second mode comprises a first read-only memory for storing a first program to be executed in the first mode, a second, programmable read-only memory for storing a second program to be executed in the second mode, an input circuit for inputting the second program to be written in the second read-only memory, an execution circuit for executing the first program or the second program, and a mode control circuit responsive to a mode selection signal for enabling execution of the first program when the mode selection signal designates the first mode and for enabling writing and execution of the second program when the mode selection signal designates the second mode.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is related to patent application Ser. No. 357,106 filed Mar. 11, 1982, now abandoned, the assignee of which is the same as the present application.
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention is in the field of power semiconductor devices generally and is directed to overvoltage protection of thyristors specifically.
2. Description of the Prior Art:
Typically overvoltage protection of a thyristor employs an avalanche current in the gate region to trigger the thyristor. The avalanching is achieved by etching a deep well, approximately 10 mils, in the gate region, during processing of a silicon wafer, the etching usually occurring after an aluminum diffusion and before a gallium diffusion is carried out. The avalanche voltage is determined by the depth and profile of the etched well.
The use of avalanching for self-protection will succeed or fail depending upon whether the avalanche voltage is less than or more than the edge breakdown voltage of the device.
The use of avalanching necessarily involves some derating of the electrical parameters of the device. Particularly, there is a derating of the forward blocking voltage, V DRM , along with an attendant increase in forward drop, V F , for the same V DRM .
A major shortcoming of the prior art etched well protection system is the requirement that the well be formed relatively early in the wafer fabrication processing, before the blocking capability of the thyristor can be measured.
Another shortcoming of this prior art is the difficulty of controlling the subsequent gallium diffusion, after the etching of the well, to obtain the necessary curvature of the forward blocking junction.
The deep well prior art is discussed in "Thyristors With Overvoltage Self-Protection", J. X. Przybysz and E. S. Schlegel, 1981 IEDM, pgs. 410-413.
Two other prior art methods of overvoltage protection are (1) a thinned anode base for controlling V BO location and voltage level, and (2) using a curved forward blocking junction.
Both of these methods require building in the protection before the thyristor is completed and its parameters measured.
A deep well that results in avalanching at 2800 volts provides no protection to a thyristor which experiences edge breakdown at 2700 volts. On the other hand, a 2800 volt avalanche is too much derating for a thyristor which could block 3200 volts.
The deep well avalanche method leaves the process engineer the choice between high yield with greatly derated thyristors or a low yield with only slightly derated devices.
The curved junction technique frequently results in low yields due to the diffuculty in masking p-type diffusions.
The thin anode base and curved junction technique for achieving overvoltage protection are discussed in "Controlled Thyristor Turn-On For High DI/DT Capability", V. A. K. Temple, 1981 IEDM, pgs. 406-409.
The use of auxiliary thyristors and inhomogeneous or heterogeneous doping of the n-type base region is discussed in "A Thyristor Protected Against di/dt Failure At Breakdown Turn-On", P. Voss, Solid State Electronics, 1974, Vol. 17, pgs. 655-661.
U.S. Pat. No. 4,003,072 teaches curved junctions as a means of overvoltage protection.
"A New Bipolar Transistor-GAT", Hisao Kondo and Yoshinori Yukimoto, IEEE Transactions On Electronic Devices, Vol. Ed. 27 No. 2, Feb. 1980, pgs. 373-379 is a typical example of prior art teachings of a transistor in which the base region has portions extending deeper into the collector region than the remainder of the base region to contact the depletion region.
Application Ser. No. 190,699 filed Sept. 25, 1980, now abandoned, is an example of several applications filed in which the p-type base region of a thyristor has spacedapart portions extending into the n-type base region to contact the depletion region.
Application Ser. No. 357,106, filed Mar. 3, 1982, now abandoned, teaches providing overvoltage protection in a thyristor by pulsing the center of a gating region of a thyristor with a laser thereby deforming the blocking junction and resulting in a portion of the p-type base extending into the n-type base region.
SUMMARY OF THE INVENTION
The present invention is directed to a process for providing overvoltage self-protection in a thyristor, said thyristor being comprised of a cathode emitter region, a cathode base region, an anode base region and an anode emitter region, metal electrodes in ohmic electrical contact with said cathode emitter region, anode emitter region and one of said base regions, said process comprising forming a well in said one base region and disposing an electrical contact in said well, said metal contact being in an electrical contact relationship with said electrode in ohmic contact with said one base region.
The present invention also includes an overvoltage self-protected thyristor being comprised of a body of silicon, said body of silicon having a top surface, a bottom surface and an edge portion extending between said top and bottom surfaces, said thyristor being comprised of a cathode emitter region, a cathode base region, an anode base region and an anode emitter region, a p-n junction between adjacent regions, said cathode emitter region being segmented and extending from the top surface of said body into said body a predetermined first distance, said cathode base region extending from said top surface of said body, where it surrounds said segments of said cathode emitter region, into said body a predetermined second distance, said second distance being greater than said first distance, a central portion of said top surface being comprised of only said cathode base region, first metal electrodes disposed on said top surface of said body in ohmic electrical contact with both said cathode emitter region and said cathode base regions, a second ring-shaped metal electrode disposed centrally on the top surface of the body in ohmic electrical contact with only said cathode base region, walls of said cathode base region forming a well within said cathode base region, said well having side walls and a bottom surface, the well extending from the top surface of the body, and having its opening completely surrounded by said second ring-shaped electrode, into said cathode base region a predetermined distance, said predetermined distance being such that a space charge region of said p-n junction between said cathode base region and said anode base contacts the bottom surface of the well at a predetermined breakover voltage and a third metal electrode in an ohmic electrical contact relationship with at least the bottom surface of the well and the ring-shaped electrode disposed about the opening of the well on the top surface of the body.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference should be had to the following detailed description and drawings in which:
FIG. 1 is a side view in section of a thyristor prior to processing in accordance with the teachings of this invention;
FIG. 2 is a side view, in section of the thyristor of FIG. 1 after processing in accordance with the teachings of this invention; and
FIGS. 3 and 4 are I-V traces of the thyristor of FIG. 2 at 25° C. and 125° C.
DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to FIG. 1, there is shown a thyristor 10.
The thyristor 10 is a typical thyristor known to those skilled in the art. The thyristor 10, comprised of silicon, has a segmented cathode emitter region 12 which is of N+ type conductivity doped to a surface concentration of from 10 19 to 10 20 atoms/cc and has a doping concentration of about 6×10 16 atoms/cc at its other major surface 13. Typically, the cathode emitter region 12 has a thickness of from 15 to 20 microns. There is a cathode base region 14 adjacent to the cathode emitter region. The cathode base region 14 is of p-type conductivity and doped to a surface concentration of from 5×10 17 to 10 19 atoms/cc. Typically, the cathode base region has a thickness of from 70 to 90 microns. There is a p-n junction 16 between regions 12 and 14.
Adjacent to the cathode emitter base region 14 is an anode base region 18. The anode base region 18 is of n-type 55 ohm-cm conductivity. The thickness of the anode base region is dependent on the breakdown voltage capability desired for the thyristor. Typically, the anode base region will have a thickness of one micron for each 10 volts of breakdown voltage desired. A thickness of 230 microns is typical.
There is a p-n junction 20 between regions 14 and 18.
Anode emitter region 22 is adjacent to the anode base region 18. The anode emitter region 22 is of p+ type conductivity and is doped to a surface concentration of from 5×10 17 to 10 19 atoms/cc. Typically, the anode base region has a thickness of from 70 to 90 microns and normally is of the same thickness as p-type region 14.
There is a p-n junction 24 between regions 18 and 22.
There is also an auxiliary emitter or floating gate region 26 formed in the cathode base region 14 and spaced apart from the cathode emitter region 12. The auxiliary emitter or floating gate region 26 is of n-type conductivity and doped to a surface concentration of from 10 19 to 10 20 . There is a p-n junction 29 between regions 26 and 12.
An aluminum ohmic contact 28, referred to as an emitter contact, is affixed to, and in ohmic electrical contact with the segments of the cathode emitter regions 12 on top surface 30 of the thyristor 10 and is also in ohmic electrical contact with base region 14. This in effect electrically shorts regions 12 and 14.
A second aluminum ohmic contact 32 is affixed to the auxiliary emitter or floating gate region 26 on top surface 30 of the thyristor 10. The ohmic contact 32 is in ohmic electrical contact with both the auxiliary emitter region 26 and the cathode base region 14 and bridges the p-n junction 29 where the junction 29 intersects surface 30.
A circular or ring gate contact 34 is disposed on surface 30 in ohmic electrical contact with cathode base region 14.
The contacts 28, 32 and 34 all disposed on top surface 30 of the thyristor 10 are spaced apart from each other as shown in FIG. 1.
An anode emitter contact 36, preferably of molybdenum, is affixed to bottom surface 38 of the thyristor 10 in ohmic electrical contact with the anode emitter region 22.
It should be understood that the thyristor 10 of FIG. 1 is a finished thyristor.
In practicing the teaching of this invention, a curve tracer 40 is electrically connected between the cathode emitter contact 28 and the anode emitter contact 36 by electrical conductors 42 and 43, respectively. A suitable curve tracer is one sold commercially by Tektronix and designated as Curve Trace 576.
With the thyristor 10 connected to the curve tracer 40 the IV characteristic of the thyristor 10 is determined.
With reference to FIG. 2, a laser is then used to pulse the thyristor 10 at approximate the center of the cathode base region. The pulsing is carried out on top surface 30 between the ring gate contact 34 and results in the formation of a well 46 in the anode base region 14.
The IV characteristic of the thyristor is measured after each pulse or after a few pulses at the beginning and then after each pulse to determine the blocking voltage. The laser pulsing is continued until the desired blocking voltage is realized.
The laser used in practicing the present invention may be a YAG laser or a ruby laser.
With a YAG laser, pulse widths may vary from about one nanosecond to about one millisecond and energy per pulse from 70 to 80 millijoules. Energy per pulse may, however, be considerably less as for example as small as 3 to 15 millijoules.
With a ruby laser, pulse widths may vary from about 20 microseconds to about 1 millisecond with an energy per pulse of about 200 millijoules.
With a device such as described relative to FIG. 1, eighteen pulses of a YAG laser with an energy per pulse of 70 to 80 millijoules produced wells of from 44 to 47 microns deep.
The well 46 may also be formed by means other than a laser.
For example, wells have been formed by drilling or abrading using 1/16 inch to 1/32 inch diameter carbide bits powered by a 20,000 rpm air grinder. Wells have also been formed using a Comco Inc. Microabrasive Glove Box and forming the well by abrasive blasting as for example with 10 micron alumina powder propelled at 70 psi through an 18 mil nozzle.
Following the formation of the well, a piece of solder is disposed in the well and melted in situ. The quantity of solder used must be sufficient to cover the bottom of the well and extend up to and make contact with gate electrode 34.
The melting of the solder may be accomplished by heating with a CO 2 laser.
Upon re-solidification the solder 48 comprises an electrical contact between the bottom of the well and gate electrode or contact 34. The contact between the solder and the silicon, at the bottom of the well, may be an ohmic contact or a Schottky contact.
A suitable solder is one sold commercially under the designation Consil 970 which consists by weight 97% silver, 2% lead and 1% antimony.
Any suitable metal solder can be used as long as it makes good electrical contact to the silicon and the gate contact or electrode.
In operating the thyristor of this invention, prepared in accordance with the teachings of this invention, at the self-protected switching voltage, the spacecharge region of the forward blocking junction contacts the bottom of the well. The electrical fields, which are present in the space charge region, draw a current out of the solder contact 48, and this causes the thyristor to switch on. The switching occurs very abruptly, at a low current, and at a voltage which is stable with respect to temperature.
A thyristor of the type described in FIGS. 1 and 2 was fabricated.
The thyristor had a cathode emitter region doped to a surface concentration of 10 20 atoms/cc. The cathode emitter region was 17 microns thick. The cathode base region and the anode emitter regions were each doped to a surface concentration of 8×10 17 atoms/cc and had a thickness of 75 microns. The doping concentration of the cathode emitter region at the interface with the cathode base region was 6×10 16 atoms/cc. The anode base region was doped to a concentration of 9×10 13 atoms/cc and had a thickness of 230 microns.
The thyristor was connected to a Tektronix 576 Curve Tracer as described above and pulsed with a YAG laser to form a well.
The pulse width was 100 microseconds and the energy per pulse was 70 millijoules.
After the eighteenth pulse, a sharp knee appeared in the current voltage characteristic at 1600 volts. The well at this point was 45 microns deep.
A 2 mil foil of the silver, lead antimony solder sold commercially as Consil 970, and described above, was disposed in the well and melted in situ using a CO 2 laser of 47 watt power focussed to a 20 mil diameter spot on the solder foil.
FIG. 3 shows the self-protected switching of this thyristor at about 1500 volts at room temperature, 25° C.
With reference to FIG. 4, the thyristor was heated to 125° C. and it can be seen that the thyristor still switched at 1500 volts with a low switching current.
This excellent temperature stability is attributable to the fact that no leakage currents are involved in generating the switching current.
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The present invention is directed to a process for providing overvoltage protection to a thyristor and to the thyristor so protected and comprises contacting the space charge region of the forward blocking junction of the thyristor with an electrical contact when the predetermined switching voltage is reached.
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This application is a continuation of Ser. No. 08/657,687, filed May 31, 1996, now U.S. Pat. No. 5,794,311.
BACKGROUND OF THE INVENTION
The present invention relates to an opening roller for an open-end spinning device. Opener rollers are used with open-end spinning devices to separate the fibers to be spun and which are fed to the opener roller in the form of a fiber sliver. It rotates at high speed and with its clothing, consisting of teeth or needles, it separates individual fibers, which are then fed to a spinning element, from the fiber sliver. The clothing of an opener roller is in fact not suitable for all fiber materials, so that when a spinning machine is changed over to a new type of material, the opener roller or its clothing must be replaced. The clothing is furthermore subject to wear, so that replacement of the clothing is also required for this reason. In the state of the art different embodiments of an opener roller are known, whose clothing is replaceable. The opener roller is installed on a shaft which is supported by a bearing, so that the opener roller is designed to be rotatable in this manner, whereby at least a part of the opener roller which is made up of several parts is connected to the shaft. This connection is usually effected by means of a press fit.
DE-OS 25 28 485 discloses the possibility of making the clothing of the opener roller in several parts for the purpose of replaceability, whereby it consists of a basic body which is connected to a shaft by means of a press fit and whereby the clothing is installed on the opener roller by means of a clothing holder in such a manner that a secure coordination between basic body and clothing holder is ensured. It is impossible for the clothing to come loose or to rotate. For this purpose, fasteners, e.g. in the form of screws are provided which reach through an opening in the clothing holder all the way into the basic body. These fasteners are located on the face of the opener roller which is located on the side away from the bearing of the opener roller. This design has the disadvantage that surface of this face is roughened by the fasteners. Fiber particles can be caught there and accumulate, and then become loose again, causing faulty spots in the yarn. It is also a disadvantage that the shaft extends into the face.
It is a known method to make the face of the opener rollers as much as possible without edges, but the solutions proposed are not very satisfactory. U.S. Pat. No. 4,296,527 discloses an embodiment which does not use fasteners. For this, the basic body and the clothing holder are designed so as to become attached to each other via threads, for example. Another embodiment is also shown here, in which the clothing holder is attached by means of a screw to the opener roller on the face away from the bearing. Thus the second embodiment resembles also that of DE-OS 25 28 485. The first embodiment mentioned has the disadvantage that its manufacture is expensive, or that the connection between basic body and clothing holder is either not secure enough, or the connection is difficult to disconnect.
Patent CH 661 535 A5 discloses another opener roller whose clothing holder is attached without fasteners. To accomplish this, it is shrink-fitted as the basic body on the shaft. This has the disadvantage that a replacement of the clothing is time-consuming. Besides, the shaft on which the opener roller is supported may be damaged from the repeated installation of a press-fit.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore a principal object of the present invention to design an opener roller for an open-end spinning machine in such a manner that the clothing can be exchanged easily and rapidly, with a simple construction and fasteners, and with the opener roller designed and the fasteners placed in such a manner that the yarn quality is not affected. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the descriptions or may be learned through practice of the invention.
The invention is based on the realization that it is not sufficient to make the fasteners as much as possible free of edges, but surprisingly also that it matters on which of the two faces of the opener rollers the fasteners are located. In further development of the opener roller housings for opener rollers of open-end spinning machines, the state of the art provided in the meantime for the fiber to be conveyed not only as before, exclusively in the circumferential sense in the area of the clothing, but for certain applications of the fibers, provided also the possibility of taking a direction in the opener roller housing which guides them along the face of the opener roller. The fibers were conveyed here along the face of the opener roller which is away from the bearing. This realization has led to new standards against which the development of opener rollers is measured.
The movement of the fibers in the opener roller housing as described above is described in the German patent application P 43 41 411.7-26. The result of the design of the opener roller according to the invention is that the face of the opener roller away from the bearing can be an even surface which has no raised areas, depressions, or other edges on which fibers may catch. Thanks to this design, this opener roller can also be used in open-end spinning machines having improved fiber conveying in the opener roller housing. Thanks to the utilization of fasteners expensive embodiments of basic body and clothing holder which can be connected to each other through their own form can be dispensed with, and the less costly type of attachment, e.g. with screws, can be used. This has at the same time the advantage that it can be serviced more easily and, at the same time, ensures secure connection of basic body and clothing holder, covering the shaft also in a simple manner.
It is especially advantageous if the basic body is designed so that it contains the face towards the bearing, as this makes it possible to exchange the clothing holder easily because it need not be moved beyond the bearing. The danger of damage to the clothing during its replacement is thereby reduced. Furthermore, the bore of the hub of the basic body can thus go all the way through, rendering its machining easier, and the shaft can be covered simply by the clothing holder.
However it may also be advantageous for the clothing holder to contain the face towards the bearing, in particular if the clothing holder interacts with a ring-shaped clothing support. In that case, the opener roller can be placed on its face away from the bearing for disassembly, the clothing holder can then be removed, and the ring-shaped clothing support can then be removed. This simple manipulation considerably reduces the danger of damaging the clothing. The basic body then covers the shaft with its face away from the bearing.
It is especially advantageous for the basic body or clothing holder to be designed so as to contain an opening for a fastener, whereby the opening may be a bore extending parallel to the shaft on which the opener roller is mounted. If the basic body has the opening, the fastener, e.g. a screw, is inserted through it and extends all the way into the clothing holder where the threads for this screw are located. The reverse is analogous where, in another embodiment of the opener roller, the clothing holder has the opening through which the fastener is inserted which then ends in the threads of the basic body.
In an especially advantageous embodiment of the opener roller, the clothing holder is configured so that it has an essentially cylindrical mantle surface which is approximately as wide as the clothing in the axial direction and this clothing is installed on the mantle surface of the clothing holder. This may be accomplished by means of a toothed wire for example, or e.g., also by means of a firmly press-fitted clothing support which may be provided with needles or teeth.
In another advantageous embodiment of the clothing holder, the latter is provided with a seat by means of which a ring-shaped clothing support is radially supported.
In another advantageous embodiment of the clothing holder, the latter is provided with a stop which bears axially upon a clothing support and thus holds it against the basic body. In that case, it is also possible for the clothing holder to be provided with a seat as well as with a stop.
In an advantageous embodiment of the fastener, the latter is made in form of screws, it being especially advantageous for them to be placed at even distances from each other. It is especially advantageous here to see to it that the distribution of mass on the opener roller is uniform, so as to avoid imbalance in its running. It is also possible to consider one single fastener if provisions are made for the opener roller to be balanced. Advantageously, three screws are used for the connection between basic body and clothing holder. If countersunk head screws are used, these have the advantage of only minimally disturbing the evenness of the face through which they are inserted if they are suitably designed.
An embodiment of the opener roller in which the threads for the screw are located in the clothing holder is especially advantageous, because in this case the opener roller is provided with new threads each time the clothing holder is replaced. Since the clothing holder is often made of aluminum, fastening is always equally easy even in case of frequent replacement of the clothing, since the fasteners are able to interact with unused threads.
In an especially advantageous embodiment, the clothing holder is provided with an axial bore which is closed by a cover during operation of the opener roller. This cover is inserted into the clothing holder in such a manner that this face of the opener roller practically constitutes a completely flat surface. This is because if the clothing holder has this axial bore, and in case that the clothing is coated in its manufacture, several clothing holders can be supported on one support thanks to this axial bore, so that coating can be rendered simpler and less costly. It is especially advantageous when the cover is disassembled, as the interior of the opener roller can then be cleaned without having to disassemble the clothing holder.
For the installation of clothing holder on the basic body, it is advantageous to provide an adjusting device on the opener roller which makes it easier during assembly to align the openings through which the fasteners, e.g. screws, are inserted exactly with the appertaining threads, so that the latter need not first be located. For this purpose a stop is provided which signals the correct position of clothing holder relative to the basic body. If the stop interacts with a helicoidal edge on the basic body, this has the advantage that the clothing holder can be set on the basic body and is then rotated until the stop fits inside. Further rotation in the same direction causes the stop to be brought into its end position which then indicates correct alignment. A helicoidal edge has the advantage here, that if rotation is effected in the wrong direction, no abrupt stopping occurs, but merely increasingly difficult rotation and finally jamming. It is especially advantageous for at least the face of the opener roller away from the bearing to be provided with a helicoidal hub which is placed so that air is conveyed radially outward from the area of the axis of rotation of the face as a result of the rotation of the opener roller.
In an advantageous further development, at least the clothing holder is to be an extruded component. Thereby a non-porous surface can be produced, so that the component can be coated at especially low cost.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an opener roller with its bearing, partly in a section
FIG. 2 is a partial representation of an opener roller in section, with a ring-shaped clothing support;
FIG. 3 is a top view of the basic body with a cut-away representation of the clothing holder and
FIG. 4 is a top view of the face of an opener roller away from the bearing
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the presently preferred embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. It is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents.
The opener roller 1 of FIG. 1 is mounted on a shaft 2 which is supported in a bearing 3. On its side away from the opener roller 1, the shaft 2 is provided with a wharves 21 via which the opener roller is driven by means of a belt. The opener roller 1 itself, which is shown in the lower half of the drawing in a section, consists of a basic body 11 and a clothing holder 12. The clothing holder 12 is connected to the basic body 11 through a fastener 4 in the form of a screw 41. The basic body 11 has a hub 111 which is pressed on shaft 2 by means of a press-fit. The basic body 11 has an opening 112 in the form of a bore through which the screw 41 is inserted and extends all the way into the clothing holder 12 where it interacts with threads 117. The opening 112 extends parallel to axis 22 of shaft 2. The clothing holder 12 is attached according to the invention on the side of the face 14 of opener roller 1 towards the bearing 3. This means that the surface of the face towards the bearing is interrupted because the fastener 4 extends through its surface. However, because the screw 41 is in the form of a countersunk head screw, the disturbance of the evenness and smoothness of the surface of face 14 is kept at a minimum.
The opening 112 is countersunk in the area of face 14 to receive the countersunk head screw 41. To increase the stability of the basic body 11, and in particular of its hub 111, it is reinforced by means of ribs 114. It is especially advantageous for the basic body 11 to be provided with air ducts 115. Shaft 2 is provided with a bore 23 parallel to its axis so that the air duct 115 is connected via bore 23 with the outside air, i.e. the air outside an opener roller housing. This has the advantage that the sealing gap 9 between the basic body 11 and the sleeve 31 of bearing 3 is connected to the outside air. As a result, air is able to flow through bore 23 through the air duct 115 and into the area in front of the face 14 towards the bearing. The result of this is that the interior of the opener roller is kept free of fibers and dirt which would otherwise reach the interior through the sealing gap 9 and could soil the ball bearing of shaft 2, for example, or could accumulate to such an extent that a rotation of the basic body relative to sleeve 31 of bearing 3 is no longer possible. Penetration of dirt or fibers into the opener roller can occur in the particular in case of unfavorable pressure conditions in the opener roller housing.
The basic body 11 is provided with a receiving surface 116 through which the clothing holder 12 is centered on the basic body 11. The clothing holder 12 is provided with a cylindrical mantle surface 121 having an axial length equal to the width of the clothing 8 installed on the mantle surface. The clothing holder 12 is made in one piece with the cylindrical mantle surface 121, and this provides an especially favorable and simple embodiment. The cylindrical mantle surface 121 is provided with grooves 122 into which the foot of the clothing wire is press-fitted. The face 15 of opener roller 1 away from bearing 3 is here constituted by the clothing holder 12.
It is also conceivable, in another embodiment of the basic body 11, that the latter extend as far as into the plane of the face 15 away from the bearing 3, so that this face would be constituted in part by the basic body 11 and in part by the clothing holder 12. This would however have the disadvantage that a gap would be produced between the two into which dirt caused by fibers could accumulate and lead to interference with the spinning operation. It is however a special advantage over the state of the art, in this embodiment, that the shaft does not reach into the plane of the face 15 towards the bearing 3 but is covered by the basic body 11 or the clothing holder 12. This is because the end of shaft 2 is especially conducive to the accumulation of fibers. The clothing holder 12 of FIG. 1 is provided with an axial bore 123 which is closed by cover 124 so that the face 15 away from bearing 3 is completely even, whereby the transition between cover 124 and the clothing holder 12 has so insignificant a gap that it cannot lead to interference with the spinning operation. The axial bore 123 is provided in order to facilitate the handling of the clothing holder 12 during its manufacture. Especially if the clothing 8 is coated, the presence of axial bores 123 make it possible to thread several clothing holders 12 on a mandrel so that they may be coated together.
In the embodiment of FIG. 1 the basic body 11 is provided with the face 14 towards bearing 3. It would however be just as possible to design the basic body so that it be provided with the face 15 away from bearing 3. This has the corresponding consequence that the clothing holder would be provided with the face 14 towards bearing 3. During assembly or disassembly the clothing holder would then have to be brought to the basic body via bearing 3. The basic body would then correspondingly be provided with the threads into which the screws are screwed in, and the clothing holder would be provided with an opening for the insertion of the screw. The embodiment shown in FIG. 1 has the advantage over this embodiment that whenever the clothing holder 12 is replaced, new threads 117 are used each time. Since the opener roller is most often made of aluminum which is not very hard and could wear out the threads faster, this is especially advantageous.
The opener roller partially shown in a section in FIG. 2 also contains a fastener 4 by means of which the face 14 towards bearing 3 is attached. The opener roller of FIG. 2 has however a ring-shaped clothing support 7 which is connected to the basic body 11 by means of the clothing holder 12 and the fastener 4. The clothing holder 12 is provided with a seat 125 which holds the ring-shaped clothing support radially. At the same time the clothing holder 12 is provided with a stop 126 which holds the ring-shaped clothing support 7 axially. In the embodiment shown in FIG. 2, the clothing support 7 is provided with a clothing 8 consisting of a mounted clothing wire. The clothing support 7 can however be provided with a clothing which is cut from the solid block, e.g. which is ground out of the clothing support 7. It is of course equally possible to use clothing supports 7 equipped with needles. By contrast with the embodiment of FIG. 1, the clothing holder 12 is not provided with an axial bore (123, FIG. 1) To convey air through the bore 23 of shaft 2 in the area of the clothing holder 12, the latter is provided with a air-guiding groove (not shown) so that the air duct 115 of the basic body 11 is connected via bore 23 of shaft 2 to the outside air.
FIG. 3 shows a top view of the opener roller of FIG. 1 from the side away from bearing 3, whereby the clothing holder is shown in a cutaway in the area of line A--A of FIG. 1. The adjusting device consists essentially of an adjusting stop 61 which is installed on the clothing holder 12 and of an edge 62 which is formed on the basic body 11. The edge 62 is in the form of a helicoidal line deviating slightly from a circular line, with the center in the center of the opener roller. The opener roller of FIG. 3 is provided with three such helicoidal edges 62 and the clothing holder 12 correspondingly with three adjusting stops. At the beginning or end of each helicoidal edge 62 a shoulder 63 is produced due to the changed distance from the edge 62 to the center, whereby the adjusting stop 61 impacts against this shoulder 63 to adjust the clothing holder relative to the basic body 11. The helicoidal form of edge 62 has the advantage that when the clothing holder 12 is mounted on the basic body 11, the adjusting stop 61 is generally to be found in an area in which the distance from the adjusting stop 61 to the center of the opener roller is smaller than the distance to the edge 62. This means that the clothing holder 12 does not catch on the basic body 11. Only by rotation of the clothing holder 12 to the right relative to the basic body 11 does the adjusting stop 61 arrive in an area in which a clearance exists between the adjusting stop 61 and the edge 62, so that the clothing holder is seated on the basic body 11. In order to bring the threads (117, FIG. 1) into alignment with the opening 112, the clothing holder 12 only needs to be rotated further in the same direction, until the adjusting stop 61 of the clothing holder 12 impacts the shoulder 63 of the basic body 11. In the embodiment of FIG. 3, three shoulders 63 exist and have the advantage that when the clothing holder 12 is placed on the opener roller 1, the latter does not jam as readily. It is also possible to operate with fewer shoulders or adjusting stops.
FIG. 4 shows a top view of the face 14 of the opener roller away from the bearing. In this embodiment the face 14 is provided with a helicoidal groove 140 which is used to convey air from the area of the rotational axis of the opener roller radially to the outside when the opener roller rotates. The helicoidal groove 140 need not extend to the center of face 14 in this case. It is sufficient if a curved groove 140 is provided at least in the outer area of face 14, suitable to convey air radially to the outside when the opener roller is used (arrow P). Such a shorter groove, not shown in FIG. 4, is especially suitable for the face of the opener roller towards the bearing. In the design of groove 140, care must be taken that it does not have edges on which fibers could settle.
In the description of the present invention, screws in particular were described as fasteners. It is however also possible to use a bayonet-type closure.
It will be apparent to those skilled in the art that various modifications and variations can be made in the invention without departing from the scope and spirit of the invention. It is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents.
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For an opener roller for an open-end spinning device provided with a basic body by which it is connected to a supported shaft for rotatable support, it is proposed that the clothing be attached to the basic body via a clothing holder, whereby fasteners are used. For the fixed allocation of the clothing holder to the basic body it is provided that the attachment of the clothing holder by means of the fasteners be effected from the side of the opener roller which is facing the shaft bearing. The face of the opener roller away from the shaft covers the shaft, so that this face of the opener roller is also an even surface.
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FIELD OF THE INVENTION
The invention relates to fittings used to cover pipe insulation. More particularly, the invention relates to fittings made of poly(vinyl chloride) adapted to provide enhanced stiffness to the fitting covers.
BACKGROUND OF THE INVENTION
Insulation has long been used to cover piping through which either hot or cold fluids flow.
Early efforts at insulating piping consisted of spreading cement in place on the exterior of the piping and pipe fitting and then adhering a fabric over the cement. Since then, insulation techniques have been developed that include various insulating materials, such as fiberglass covered with aluminum or plastic coverings. The aluminum and plastic covering are variously formed to take the shape of pipe lengths and pipe fittings.
The plastic coverings have generally been formed of commercial grade poly(vinyl chloride). Typically, the poly(vinyl chloride) used in coverings for pipe insulation has a specific gravity in the range of 1.44.
The poly(vinyl chloride) fittings have been formed into many shapes, some taking the shape of a Tee, an elbow or any other fitting to be covered. Others, such as described in U.S. Pat. No. 3,495,629 (Botsolas, Feb. 17, 1970) are designed with a first shape different from the fitting to be covered but with the capacity to be manipulated into a second shape in the form of the fitting to be covered.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a poly(vinyl chloride) fitting having a low specific gravity and stiffness characteristics greater than previously experienced by poly(vinyl chloride) insulation fitting covers.
It is another object of the invention to provide a process to produce poly(vinyl chloride) fitting covers having enhanced stiffness characteristics.
It is a further object of the present invention to produce fitting covers having stiff, hard exterior surfaces and foam-like interior with enhanced insulation characteristics.
It is still a further object of the present invention to provide poly(vinyl chloride) sheets that can be vacuum formed into large, relatively light weight fitting covers; i.e., above eighteen inches.
Thus, a process for producing poly(vinyl chloride) fitting and pipe covers has been created wherein the poly(vinyl chloride) for the cover is produced with a blowing agent dispersion.
In essence, the blowing agent dispersion is preproduced in a pre-dispersion process in which the dispersion medium components are initially milled at temperatures in the 140° C. range and thereafter Barium Stearate and polyurethane elastomer are cut and folded into the dispersion. Finally, the blowing agent system is completed by adding azodicarbonamide and allowing the dispersion to cool to room temperature.
Thereafter, the blowing agent dispersion goes through a size reduction process and is added to a conventional poly(vinyl chloride) composition. Approximately one hundred parts of poly(vinyl chloride); two parts of dibutyl tin bis iso octyl thioglycolate; three parts acrylic processing aid and twelve parts impact modifier; twelve parts titanium dioxide; one and three quarters parts of Calcium Stearate; one and one-quarter parts parafin wax; one-half part oxidized polyethylene; and one and one-quarter part of the blowing agent dispersion are combined at high temperatures to provide the modified poly(vinyl chloride) for the fitting cover.
In a continuous process, the modified poly(vinyl chloride) is extruded at temperatures in the range of 365° F. and immediately subjected to sheet forming through a conventional three-roller assembly that has been cooled to approximately 70° F.
The sheets of modified poly(vinyl chloride) are then vacuum formed into the desired fitting cover shapes or cut to size to form pipe covers and produce fitting and pipe section covers having a specific gravity of about 1.03 and enhanced stiffness.
DESCRIPTION OF THE DRAWING
The invention will be better understood when viewed with the following drawings wherein:
FIG. 1 is a process flow diagram illustrating a process of the present invention;
FIG. 2 is an illustration of one fitting cover of the present invention; and
FIG. 3 is a cross-sectional view of the fitting cover of FIG. 2 taken through line 3--3 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention has application with any insulation fitting cover and utility in environments wherein low specific gravity poly(vinyl chloride) having enhanced stiffness characteristics is desirable.
Thus, the invention will be described in detail in the formation of a poly(vinyl chloride) elbow fitting cover.
As best seen in FIG. 1, a blowing agent dispersion medium is pre-formed as a pre-dispersed composition in mixing equipment shown schematically as mill 2.
In production, the pre-dispersion can be formed in any suitable, batch blending apparatus. However, it has been pre-dispersed in development by first milling, the dispersion medium additives at elevated temperatures such as 140° C. and, after fusion, cutting and folding Barium tearate and thermoplastic urethane into the pre-dispersion with the final step being the addition of a blowing agent, in this case, azodicarbonamide. Upon completion of the formation of the blowing agent dispersion the poly(vinyl chloride) composition is formed using the blowing agent dispersion to provide a poly(vinyl chloride) with enhanced properties for use as insulation covers.
The poly(vinyl chloride) composition is again formed in any suitable mixing or blending apparatus. Practice has shown that a high intensity mixer such as a Henschel mixer 4 is well suited for the application.
Poly(vinyl chloride) resin and dibutyl tin bis iso octyl thioglycolate are first charged to the mixer 4 and heated to a temperature in the range of 165° F. Next, an impact modifier is added to the dispersion in the mixer 4 and the temperature further elevated, e.g. to about 185° F. Thereafter, calcium stearate and parafin wax are added to the dispersion in the mixer 4 and the temperature again increased, e.g. to about 200° F.
The dispersion is then dropped into a cooling blender 6 and the blowing agent dispersion initially produced is added to form the final poly(vinyl chloride) dispersion which is cooled in the cooling blender to about 120° F.
The final poly(vinyl chloride) dispersion is formed into sheets in the sheet forming assembly 12 seen in FIG. 1, which is comprised of a hopper 14, extrusion assembly 16 and a three roll stack 18.
The extruder assembly 16 is arranged with the extruded die opening 20 in close adjacent relationship to the roll stack 18, e.g., one and one-half inches apart. Practice has shown that a Cincinnati Millicron extruder CM-80 with high performance screws feeding a fifty-two inch die 20 can be used in this application.
The extruder assembly 16 is set with the barrel, screw oil and die at elevated temperatures. Illustratively, the barrel temperature is set between 335° F. and 365° F., the screw oil temperature is set in the range of 340° F. and the die temperature in the range of 320° F.
All three rollers 22, 24 and 26 of the roll stack 18 are set for low temperature, i.e. a temperature below 75° F. and preferably 70° F.
The process proceeds by charging the final poly(vinyl chloride) dispersion from the cooling blender, into the hopper 14, extruding the poly(vinyl chloride) material through the extruder 16 heated as previously described and out the die 20 set for a fifty-two inch discharge and thereafter rolled into fifty-two inch sheets by the cooled roll stand 18.
The formed sheet 30 is approximately 90 mils thick and comprised of poly(vinyl chloride) having a specific density of less than 1.04; i.e. about 1.03 and an improved stiffness/weight ratio over conventional poly(vinyl chloride) when tested according to the ASTM D-790 test method. The product formed provided a hard shell 34 and a foam 36 on the inside, thus resulting in a stiffer, lighter material with better insulating properties than the poly(vinyl chloride) fitting and pipe covers previously used.
The sheet 30 is then formed into various pipe insulation covers such as the elbow cover 32 shown in FIG. 2 by conventional vacuum molding. Illustratively, a table 28 is shown in FIG. 1 with a mold 38 over which the sheet 30 is vacuum formed to produce the elbow cover 32.
An illustrative example of the process, procedure and resulting product of the present invention proceeds as follows:
The following materials are used with the respective parts to provide the blowing agent dispersion:
______________________________________Ingredients Respective Parts______________________________________poly(vinyl chloride) 100.00dibutyl tin bis iso octyl thioglycolate 2.00Butyl Benezl Phthalate 25.00urethane elastomer 43.00azodicarbonamide 35.00Barium Stearate 17.50parafin wax 1.25calcium stearate 1.75calcium carbonate 35.00______________________________________
First the poly(vinyl chloride), dibutyl tin bis iso octyl thioglycolate, butyl benzl phthalate, parafin wax, calcium stearate and calcium carbonate are cut and folded for three minutes in a mill at 140° C. Thereafter, the Barium Stearate and Urethane elastomer are added and cut and folded into the dispersion for one and one-half minutes. Finally, the azodicarbonamide (which is yellow) is added to the dispersion and mixed until a uniform color results. The dispersion is allowed to cool to room temperature and solidify. The solid is then ground to a suitable particle size for use as the system blowing agent dispersion medium.
Thereafter, the poly(vinyl chloride) composition which is ultimately charged to the hopper 14 is prepared from the following formulation:
______________________________________Ingredients Respective Parts______________________________________poly(vinyl chloride) 100.00dibutyl tin bis iso octyl thioglycolate 2.00acrylic impact modifier 12.00acrylic processing aid 3.00titanium dioxide 12.00calcium stearate 1.75parafin wax 1.25oxidized polyethylene 0.50blowing agent dispersion 1.25(from above process)______________________________________
The poly(vinyl chloride) and dibutyl tin bis iso octyl thioglycolate are charged in a Henschel mixer and elevated in temperature to 165° F. The impact modifier is added to the mixer and the composite dispersion is raised in temperature to 185° F. The calcium stearate and parafin wax are added to the mixer and the composite dispersion is raised in temperature to 200° F. Next, the titanium dioxide and acrylic processing aid are added to the mixer and the temperature is raised to 220° F. The composition is next dropped into a cooling blender wherein the blowing agent dispersion medium is added. The dispersion is cooled to 120° F. while the blowing agent dispersion medium is mixed into the dispersion, resulting in a powder at 120° F.
The resulting powder is charged to the hopper 14 and extruded through the extruder at conditions wherein the extruder barrel temperature is 335° F. to 365° F., the screw oil temperature is 340° F., the die temperature is 320° F. and the material feed and screw speed are set for 60-70 amps.
The extruder material leaving the die 20 is immediately rolled (by rollers set at 70° F.) into poly(vinyl chloride) sheets 90 mils thick and 51 inches wide. The resulting sheets were vacuum formed into insulation pipe fitting covers such as seen in FIG. 2.
Although various suppliers' materials can be used, the example was conducted with GEON 85 poly(vinyl chloride) (B. F. Goodrich Co.); CC-11 Cardinal Chemical Co. dibutyl tin bis iso octyl thioglycolate; K120N Rohm & Haas acrylic processing aid; D-200 M&T impact modifier; C-Wax Cardinal Chemical Co. 165° F. parafin wax; AC 629A Allied Chemical oxidized polyethylene; Monsanto BBP butyl benzl phthalate; TPU 455 Morton Thiokol urethane elastomer; AZRV Uniroyal azodicarbonamide; and UFT Omya Corp. calcium carbonate. Generic calcium stearate, barium stearate and titanium dioxide were used.
As used herein "pipe insulation cover" means insulation covers for both pipe lengths and the various fittings that connect the pipe lengths such as elbows, Tees, etc. As used herein "blowing agent dispersion" means the blowing agent ingredient prepared as a pre-dispersion to be added to the poly(vinyl chloride) composition ultimately used in the manufacture of the pipe insulation cover.
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A process in which a blowing agent dispersion is used for producing poly(vinyl chloride) that is particularly well suited for use in insulation covers and the insulation covers made from the resultant poly(vinyl chloride).
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention pertains to the art of cooking appliances and, more particularly, to a system for programming multiple ovens for different cooking operations, while enabling automatic sequencing of the cooking operations such that the operations can terminate simultaneously.
[0003] 2. Discussion of the Prior Art
[0004] When preparing a meal, whether in a commercial or residential setting, it is typically necessary to plan in advance the sequence in which different food items will be cooked in an attempt to have all the components of the meal completed at the same time. In some environments, only a single oven is available such that it is impossible to have all of the desired components of the meal done at the same time. However, the facilities at essentially all commercial cooking establishments provide for multiple ovens. Even in a residential setting, dual wall ovens are fairly commonplace. In addition, slide-in ranges which incorporate multiple ovens are now advantageously available in the marketplace. In any event, there exists various scenarios wherein multiple oven cooking operations can be performed for a single overall meal.
[0005] Regardless of the availability of multiple cooking ovens, the timing in the completion of the meal depends upon individual(s) actually preparing the meal. For example, if the cook is to prepare a casserole and biscuits, with the casserole needing to be cooked at 350° F. for 60 minutes, and the biscuits at 475° F. for 12 minutes, it is necessary for the cook to timely preheat the ovens and place the biscuits for baking after the casserole has been cooking for 48 minutes. Taking into account all the remaining prep and other work which might be required in connection with the overall meal, it is not uncommon to miss the window of opportunity in timing the cooking of various components of a meal. Obviously, missing this window can have a negative effect on the success of the entire meal. Although some cooking appliances provide for the programming of a delayed cooking operation, this still requires the user to calculate the delayed cooking time between the ovens and then to program at least one oven to operate in a delay cook mode. Not only can this process be time consuming, but it leaves room for errors which could detriment the meal.
[0006] Based on the above, it would be beneficial to enable multiple cooking cavities to be programmed for separate cooking operations through a system which provides for an automatic sequencing of the cooking operations. With such an arrangement, even though the cooking operations to be performed may have various different parameters, such as cooking time and temperature, the operations can be caused to advantageously, automatically finish at the same time.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a system used to program and coordinate the cooking operations for two or more ovens such that the cooking operations are completed at the same time, independent of particular setting variations. In accordance with a preferred embodiment of the invention, a single controller is utilized to program each of the ovens, with the controller incorporating an auto sequencing feature which causes the different cooking operations to be automatically performed, while terminating at the same time. Preferably, the system enables a second cooking operation to be programmed and initiated after a first cooking operation, while still providing for the auto sequencing of the cooking operation.
[0008] In accordance with the invention, a user need not calculate any delayed cooking operation or properly time the initiation of a second cooking operation in order to assure that the multiple cooking operations will finish at the same time. In any event, additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a perspective view of a slide-in double oven range incorporating the automatic cook sequencing system of the present invention;
[0010] [0010]FIG. 2 is a perspective view of a double wall oven incorporating the automatic cook sequencing system of the invention;
[0011] [0011]FIG. 3 is a block diagram illustrating the control system of the invention; and
[0012] [0012]FIG. 4 is a flow diagram showing a control sequence in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] With initial reference to FIG. 1, the invention is illustrated for use in connection with an electric range generally indicated at 2 . In the embodiment shown, electric range 2 includes a cabinet 5 within which is arranged a first or upper oven 8 and a second or lower oven 9 . Upper and lower ovens 8 and 9 have associated doors 10 and 11 which are respectively provided with handles 12 and 13 that can be used to pivot doors 10 and 11 in order to access respective cooking chambers or cavities of ovens 8 and 9 . For the sake of completeness, this figure illustrates doors 10 and 11 with respective viewing windows 14 and 15 .
[0014] Cabinet 5 is also provided with an associated range top 18 which supports various spaced surface heating elements 20 - 23 in a manner known in the art. At an upper rear portion, cabinet 5 includes an upstanding portion 26 which is provided with a control panel 28 . At this point, it should be realized that the arrangement and location of control panel 28 could vary in accordance with the present invention. For example, control panel 28 could be located along an upper face panel 32 of cabinet 5 . In any event, upstanding portion 26 includes a plurality of knobs 36 - 39 for use in selectively activating and deactivating surface heating elements 20 - 23 respectively. Control panel 28 is preferably arranged between knobs 36 - 39 and is shown to include a substantially central display 44 , such as an LED, LCD or VFD display unit. Furthermore, control panel 28 is provided with a number pad generally indicated at 46 that has an associated button 48 for use in setting a clock arranged either within display 44 or in another portion of control panel 28 .
[0015] As also known in the art and shown in this figure, control panel 28 of range 2 includes a first row of control buttons generally indicated at 51 which are generally used to establish an operational mode for upper oven 8 . Although not separately labeled, first row 51 preferably includes cancel, bake, broil, cleaning mode, toasting, warming mode and light control members shown in the form of buttons. In a generally similar manner, a second row of control buttons 61 are provided for lower oven 9 . In the most preferred form of the invention, second row 61 includes cancel, bake, broil, cleaning mode, convection mode and light control members, preferably in the form of individual buttons. In the most preferred form of the invention, the user is able to program the operation of at least upper and lower ovens 8 and 9 through the use of the first and second rows of buttons 51 and 61 , along with numeric pad 46 , timer buttons 70 and 72 , cook time and stop time buttons 74 and 76 , and an auto set button 78 . Since this basic programming arrangement is known in the art as exemplified by U.S. Pat. No. 6,255,630 which is incorporated herein by reference, and not considered part of the present invention, it will not be described further here in detail. Instead, with reference to this first embodiment, the inclusion of sequencing button 80 , shown arranged between the convection mode and light buttons in row 61 for exemplary purposes, is of concern with respect to the present invention. In general, sequencing button 80 can be used to cause programmed cooking operations for ovens 8 and 9 to automatically terminate at the same time, regardless of whether different cooking levels, times and/or modes are selected. In any event, additional details of the preferred sequencing control will be presented below after discussing the embodiment of FIG. 2.
[0016] [0016]FIG. 2 shows the invention in connection with a cooking appliance 102 depicted as a wall oven. In the embodiment shown, cooking appliance 102 constitutes a dual oven wall unit which includes a structural frame 103 supporting an upper cooking cavity 104 and a lower cooking cavity 105 . According to the present invention, respective door assemblies 110 and 111 are provided to selectively provide access to upper and lower cooking cavities 104 and 105 . Cooking appliance 102 is shown to incorporate an upper control panel 112 . In the embodiment shown, control panel 112 includes first and second rows of oven control buttons 113 and 114 for programming, in combination with a numeric pad 115 and a display 117 , particular cooking operations for oven cavities 104 and 105 respectively.
[0017] Again the general programming and operation of cooking appliance 102 to perform distinct cooking operations in oven cavities 104 and 105 is known in the art and does not form part of the present invention. Instead, like the embodiment of FIG. 1, different cooking operations can be established for oven cavities 104 and 105 through upper control panel 112 . What is important to note in connection with this embodiment is that the present invention can be applied to dual wall ovens. In fact, the invention is applicable to any dual oven arrangement wherein the controls for the ovens are linked. At this point, it should be realized that the embodiment of FIG. 2 has not been described as including a button directly corresponding to sequencing button 80 of the first embodiment. Instead, in this embodiment, certain predetermined control elements on panel 112 are utilized to initiate a desired sequencing operation. For instance, depressing two or more buttons within numeric pad 115 simultaneously would initiate the sequencing operation as will not be discussed with reference to FIGS. 3 and 4.
[0018] In accordance with the invention, the sequencing operation can be performed in various fashions. In general, the control of cooking operations performed in oven cavities 8 and 9 , or 104 and 105 , are regulated by a common controller, such as CPU 200 as shown in FIG. 3 . CPU 200 receives cooking operation control inputs for upper oven cavities 8 , 104 as indicated at 205 , with upper oven inputs 205 collectively including selection from row 51 , 113 , numeric pad 46 , 115 , cook time and temperature settings. In a similar manner, CPU 200 receives cooking operation control inputs for lower oven cavities 9 , 105 as generically indicated at 210 . Additional control signals can also be received in a manner known in the art, such as temperature and door position signals as indicated at 215 and 220 respectively. Again, operating a dual oven in this general manner is known in the art. However, in accordance with the invention, CPU 200 is also linked to a sequencing control 225 , which preferably constitutes either sequencing control button 80 or a predetermined simultaneous or sequential operation of a plurality of control elements. CPU 200 can also output various operational parameters, such as audible and/or visual signals at 250 , upper oven heating element(s) 255 , lower oven heating element(s) 260 , lights 265 within the oven cavities 8 , 9 or 104 , 105 , and door locks 270 .
[0019] More specifically, in accordance with the invention, the cooking mode, temperature and/or time settings for upper and lower oven cavities 8 , 9 or 104 , 105 can vary from each other by inputs at 205 and 210 . If sequencing control 225 is not activated, separate and distinct cooking operations will simply be performed, whether immediately or on a delay basic depending on the particular operator programming. However, if sequencing control 225 is activated, CPU 200 will automatically function to sequence the two cooking operations to finish at the same time. In this sense, the operator need not calculate one or more specific delay times in order to assure that two different food items will be completed simultaneously.
[0020] [0020]FIG. 4 will now be reference to present a particular cooking example. In initial step 400 , a user establishes a first desired cooking operation in a first one of the dual oven cavities, such as a casserole to be cooked at 350° F. for sixty minutes. In accordance with the invention, a user can next establish a second desired cooking operation for the second one of the dual oven cavities in step 405 , such as arranging biscuits for cooking at 475° F. for twelve minutes. It is also possible in accordance with the invention to enable the first cooking operation to be initiated at 410 prior to proceeding to step 405 . In either case, if an automatic sequencing control signal is received at 415 , the first and second cooking operations will be automatically sequenced to finish at the same time. In the particular example provided, the start of the second cooking operation would be automatically delayed by CPU 200 for approximately forty-eight minutes and, more specifically, enough time to allow for the twelve minute cook time and, preferably, an ample warm-up period.
[0021] When employing the present invention, the user need not calculate any delay period, which can be particularly problematic if an initial delayed cooking operation is established for the first oven cavity or if the first cooking operation is already underway. If a second cooking operation is to be sequenced with a first cooking operation which is already underway and the time remaining on the first cooking operation is less than that established for the second cooking operation, CPU 200 will preferably provide an audible and/or visual non-available sequence signal to the user at 250 . In any event, if the cooking operations are successively programmed, CPU 200 will control the respective ovens to turn on the oven with the longest cook time first, then automatically sequence the other oven at an appropriate time to allow both ovens to complete their cooking functions at precisely the same time.
[0022] Although described with reference to preferred embodiments of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, as indicated above, it should be readily apparent that the automatic cook time sequencing system of the present invention can be incorporated into a variety of different types of cooking appliances having multiple ovens. To this end, it should be recognized that the ovens in accordance with the present invention can also vary and may include radiant, convection, microwave, combinations thereof, and the like. In addition, the ovens can be heated through various energy sources, including electricity or gas. Therefore, in general, the invention is only intended to be limited by the scope of the following claims.
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A system used to program and coordinate the cooking operations for two or more ovens such that the cooking operations are completed at the same time, independent of particular setting variations. In accordance with a preferred embodiment of the invention, a single controller is utilized to program each of the ovens, with the controller incorporating an auto sequencing feature which causes the different cooking operations to be automatically performed, while terminating at the same time. Preferably, the system enables a second cooking operation to be programmed and initiated after a first cooking operation, while still providing for the auto sequencing of the cooking operation.
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BACKGROUND OF THE INVENTION
The present invention generally relates to a thermostatic fluid controller, and more particularly, to a thermostatic fluid controller for showerhead assemblies and faucet assemblies featuring two thermostatic cylinders for precluding water between different pre-determined temperatures for an increased closing time over a broader range of temperatures.
Recent legislation requiring products to prevent accidents involving scalding water indicates an increased interest in devices that can control water, namely hot water. Scald-burn injuries can range from minor to life-threatening and can even cause death in certain cases. These injuries are frequently caused by water temperature fluctuation in the plumbing system. Occurrences such as toilets being flushed are common causes of water temperature fluctuations. As an example, when a toilet is flushed while a shower or faucet with a proper hot-to-cold water ratio is running, cold water is used to refill the tank of the toilet and, consequently, the water pressure, from the cold water pipes, decreases. The result is that less cold water is available for the hot/cold mix flowing to the shower, bathtub, or faucet, thereby causing the water mix to increase in temperature. In many instances, the temperature for hot water can be too hot in buildings that share a common boiler or water heater, i.e. apartment buildings, hospitals, or nursing homes. Frequently water temperatures in these residential and commercial water supplies can exceed 130° F., temperatures at which an adult can easily be scalded or burned. Children are especially vulnerable to being scalded from overly-hot bath or shower mix because they have thinner skin than adults. A child can sustain a third degree burn from exposure to 140 F water for a mere three seconds.
The water temperature in buildings that share a common boiler or water heater is often kept higher than recommended so that a sufficient source of hot water is available to a great number of users at a given time. This means that a way to regulate the temperature at the “end-line” location in buildings with a large common boiler is critical.
The serious consequences of over-hot water temperatures has caused a majority of states to enact legislation requiring new construction to incorporate anti-scald devices that feature a means of controlling maximum water temperatures delivered to the faucet and showerhead assemblies. These regulations, however, only apply to new construction and do not mandate the use of anti-scald fixtures in older buildings. Since the legislation applies only to new construction, many of the anti-scald devices currently known in the field relate to devices incorporated “in-line” or behind the walls adjacent to the showers, bathtubs or sinks, or are otherwise difficult to access and require the skill of a professional plumber.
Such “in-line” devices are incorporated within the lines of the home or business plumbing systems. These devices are normally installed prior to the interior finishing and “dry-walling.” These devices often have a reset capability for normal use. However, when the device is damaged, defective, or is unable to be reset, it is very difficult to repair or replace the device without a trained plumber. Furthermore, the devices are incorporated behind the walls, so it is necessary to tear out portions of the wall to replace or repair the device. Such destruction can be very costly. Furthermore, a device that electronically controls the temperature of water often has a sensor component, which is mounted behind the wall of the shower. In situations of an electrical malfunction or short circuit, the electronic device is only accessible by a plumber. Such systems can lead to high repair costs.
An “in-line” device is incorporated for use with existing faucet assemblies or showerhead assemblies, and is described in U.S. Pat. No. 5,584,432 (“'432 patent”). The '432 patent teaches a structure for blocking the flow of water using a shape memory alloy spring. The shape memory alloy spring stiffens at a specific temperature against a valve to preclude the flow of water from exiting the valve. The shape memory alloy spring softens at a second pre-determined temperature to enable the flow of water to exit the valve.
The previously described regulating devices in the prior art are for “in-line” locations rather than “point-of-use” locations. The Safe Drinking Water Act amendments of 1996, 104 P.L. 182 (1996), distinguishes between point-of-entry and point-of-use devices in § 105. Point-of-entry devices are located at a plumbing systems “in-line” location, or in other words, located within the plumbing supply pipes. Point-of-use devices are located at the systems “end-line” location, or in other words, the apparatus the consumer uses.
The present invention is an “end-line” device integrated into a unique faucet assembly or shower head assembly. The present invention offers an “end-line” anti-scald device providing relatively inexpensive scald prevention in both new and existing homes and/or commercial buildings. The invention's location in the water supply system, integrated into an “end-user” device offers inexpensive and efficient scald prevention. This “end-line” location offers a device that blocks the flow of excessively hot water and is located in a showerhead assembly or a faucet assembly. Previous devices are incorporated directly into the plumbing system behind the walls of a building. The present invention enables the user to incorporate an anti-scald system into pre-existing plumbing systems and can be easily replaced by the user. Replacement occurs by replacement of the unit at the end of the water line.
The previous devices utilize a single thermostatic cylinder having a specific “ramp-up” time period. These devices do not account for instances where the change in fluid temperature instantly increases because the slow reaction time of the single thermostatic cylinder. Therefore, there is a need for thermostatic fluid controllers that regulate fluid flow when fluid temperature changes at a moderate rate and when fluid temperature changes at a high rate. The present invention solves this problem by incorporating a primary and secondary thermostatic cylinder system designed to operate at separate temperatures as well as over different temperature ranges.
SUMMARY OF THE INVENTION
The present invention is directed to a thermostatic valve suitable for blocking the flow of water between predetermined temperatures that may be used in a plumbing system comprising, a valve housing having a first compartment and a second compartment, where the first compartment includes a first inlet end and a first outlet end, and the second compartment includes a second inlet end and a second outlet end; a fluid passageway which communicates between the first compartment and the second compartment; a first valve assembly which is housed within the first compartment and a second valve assembly which is housed within the second compartment, such that the first valve assembly responds to fluid temperature changes and the second valve assembly responds to fluid temperature changes, such that the first valve assembly and the second valve assembly operatively cooperate to preclude the flow of scalding fluid; the first valve assembly includes: a first spring associated with the valve housing which is proximate to the outlet aperture end; a first stopper which is biased by the first spring, such that a first face of the first stopper forms a first gap with the first outlet end; a first flange abuts a first shoulder in the first compartment, such that the first flange permits the flow of water between the first inlet end and the first outlet end; a first thermostatic cylinder having a first cylinder body, a first piston housing, and a first piston where the first cylinder body abuts the first flange, such that the first piston axially extends through the first piston housing from the first cylinder body, and the first cylinder body includes a first temperature sensitive wax, where the first temperature sensitive wax and the first piston axially cooperate to produce axial movement of the first stopper to substantially block the first outlet end; also, a second spring which biases the first cylinder body against said first flange; the second valve assembly includes: a second stopper which is biased by the second spring, such that the second stopper includes a second face forming a second gap with the second outlet end; a second flange which abuts a second shoulder in the second compartment, such that the second flange permits the flow of fluid between the second inlet and the second outlet end; a second thermostatic cylinder having a second cylinder body, a second piston housing, and a second piston, such that the second cylinder body abuts the second flange, where the second piston axially extends through the piston housing from the second cylinder body, the second cylinder body includes, a second temperature sensitive wax, such that the second temperature sensitive wax and the second piston axially cooperate to produce axial movement of the second stopper to substantially block the second outlet end; also, a third spring which biases the second cylinder body against the second flange, such that the third spring associates with the second compartment at the second inlet end.
A method of supplying temperature regulated fluid, comprising the steps of flowing hot fluid from a second compartment having temperature regulated by a second valve assembly to a first compartment having temperature regulated by a first valve assembly, such that said second compartment and the first compartment communicate to form a fluid passageway; blocking hot fluid in the first compartment by the first valve assembly when the fluid temperature rises above a third predetermined temperature, where the first valve assembly includes a first thermostatic cylinder and a first stopper which axially associates with the first thermostatic cylinder to block hot fluid from flowing through the first compartment; releasing hot fluid from the first compartment by the first valve assembly when the fluid temperature drops below the third predetermined temperature, where the first thermostatic cylinder resets to its pre-response position to release the hot fluid; blocking hot fluid in the second compartment by the second valve assembly when the fluid temperature rises above a second predetermined temperature, where the second valve assembly includes a second thermostatic cylinder and a second stopper which axially associates with the second thermostatic cylinder to block hot fluid from flowing through the second compartment; releasing hot fluid from the second compartment by the second valve assembly when the fluid temperature drops below the second predetermined temperature, where the second thermostatic cylinder resets to its pre-response position to release hot fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut-away cross section view of the thermostatic controller.
FIG. 2 is a cut-away, partial close up view of the first valve assembly in the normally open position.
FIG. 3 is a cut-away, partial close up view of the second valve assembly in the normally open position.
FIG. 4 is a cut-away, partial close up view of the first valve assembly in the closed position.
FIG. 5 is a cut-away, partial close up view of the second valve assembly in the closed position.
FIG. 6 is a cut-away cross section view of the thermostatic controller where the first valve assembly and the second valve assembly are in the closed position, respectively.
FIG. 7 is a cut-away cross section view of the thermostatic controller within a shower head, an alternate embodiment.
FIG. 8 is a partially sectional pre-assembly exploded view of the thermostatic controller and the shower head thermostatic insert housing.
FIG. 9 is a cut-away cross-sectional view of the thermostatic controller within a faucet, an alternate embodiment.
FIG. 10 is a cut-away cross-sectional view taken along line 1 - 1 of FIG. 9 of the first valve assembly and the second valve assembly detailed in a faucet assembly embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 , the thermostatic valve 10 is situated within a valve housing 9 . The valve housing 9 includes a first compartment 11 and a second compartment 12 . A fluid passageway 3 communicates between first compartment 11 and second compartment 12 to allow fluid to flow from a second inlet end 19 to a first outlet end 1 . A first valve assembly 8 is housed within first compartment 11 . The first valve assembly 8 responds to a first predetermined temperature of fluid entering a first inlet end 2 of first compartment 11 to block first outlet end 1 . A second valve assembly 21 is housed within second compartment 12 . Additionally, the second valve assembly 21 responds to a second predetermined temperature of fluid entering second inlet end 19 to block second outlet end 20 .
FIG. 2 shows an exploded view of first valve assembly 8 , which includes a first thermostatic cylinder 7 . The first thermostatic cylinder 7 includes a first cylinder body 55 , a first piston housing 56 , and a first piston 13 . The first cylinder body 55 is securely positioned against a first flange 15 by a second spring 17 . The first flange 15 abuts a first shoulder 57 as to keep first cylinder body 55 stationary against second spring 17 . A first temperature sensitive wax 43 is located in the first cylinder body 55 ; while, the first piston 13 axially extends from the first cylinder body 55 outward through first piston housing 56 . The first piston 13 axially associates between the first temperature sensitive wax 43 and a first stopper 4 . The first stopper 4 includes a first face 6 , while the first stopper 4 is biased by a first spring 14 to form a first gap 5 between first face 6 and first outlet end 1 . The first spring 14 is preferably compressed between the first outlet end 1 and first stopper 4 .
FIG. 3 details the second valve assembly 21 , which includes a second thermostatic cylinder 53 . The second thermostatic cylinder 53 includes a second cylinder body 60 , a second piston housing 61 , and a second piston 54 . The second cylinder body 60 is securely positioned against a second flange 51 by a third spring 50 that is compressed against a spring catch insert 18 at second inlet end 19 . Second flange 51 abuts a second shoulder 58 as to keep second cylinder body 60 stationary against third spring 50 . A second temperature sensitive wax 44 is located in the second cylinder body 60 , while the second piston 54 axially extends outward from second cylinder body 60 through second piston housing 61 . The second piston 54 axially associates between the second temperature sensitive wax 44 and a second stopper 47 . The second stopper 47 includes a second face 49 , while the second stopper 47 is biased by second spring 17 to form a second gap 48 between second face 49 and a second outlet end 20 of the second compartment 12 .
FIG. 4 shows the first valve assembly 8 blocking the flow of fluid from the first outlet end 1 . Preferably, the first spring 14 is a cylindrical coil spring of corrosion resistant steel with a spring rate which corresponds to a force exerted by the first temperature sensitive wax 43 when it expands to move first piston 13 . The first temperature sensitive wax 43 expands at a first predetermined temperature, such that first predetermined temperature sensitive wax 43 expands to axially associate with first piston 13 . Subsequently, at a third predetermined temperature, first piston 13 axially moves the first stopper 4 toward the first outlet end 1 . The first face 6 of first stopper 4 cooperates with the first outlet end 1 to substantially block fluid from flowing out the first outlet end 1 . Preferably, the first predetermined temperature is 113° F., where the first temperature sensitive wax 43 begins expanding. The expansion of the first temperature sensitive wax 43 results in a force upon first piston 13 at first predetermined temperature to axially engage with first stopper 4 . However, first spring 14 will prevent first stopper 4 from axially moving into contact with first outlet end 1 , thereby preventing any change in flow rate at first outlet end 1 . Preferably, when the third predetermined temperature of the first temperature sensitive wax 43 is 117° F., the first temperature sensitive wax 43 will significantly expand to axially move first stopper 4 to substantially engage first outlet end 1 and restrict flow of the fluid. In a preferred embodiment, the first valve assembly 8 substantially blocks the first outlet end 1 at a third predetermined temperature within a first time range of at least a minute. Preferably, the first valve assembly 8 will completely terminate the flow of fluid in passageway 3 at a fourth predetermined temperature of 120° F. in a second time range of 10 seconds. Alternatively, all predetermined temperatures in the can be adjusted to temperatures between 70° F. and 130° F. in order to preclude scalding.
FIG. 5 shows the second valve assembly 21 blocking the flow of fluid from the second outlet end 20 . Preferably, the second spring 17 is a cylindrical coil spring of corrosion resistance steel with a spring force and spring rate selected to enable the second temperature sensitive wax 44 to overcome the second spring 17 . The second temperature sensitive wax 44 expands at a second predetermined temperature and axially moves the second piston 54 . Preferably, the second temperature sensitive wax 44 responds to a second predetermined temperature of 130° F. or greater to expand and axially move second piston 54 to engage second stopper 47 . Immediately, second piston 54 axially moves the second stopper 47 towards second outlet end 20 . Once the fluid temperature reaches 130° F., the second face 49 substantially engages the second outlet end 20 to block fluid from flowing out of second compartment 12 . Preferably, the second cylinder body 60 has a smaller volume than first cylinder body 55 , in order for the second temperature sensitive wax 44 to quickly expand upon temperatures of 130° F. or greater. Alternatively, the distance between second outlet end 20 and second piston 54 is relatively small to facilitate a quick engagement time between second stopper 47 and second outlet end 20 . Alternatively, the second temperature sensitive wax 44 can expand in response to temperatures between 100° F. and 200° F.
FIG. 6 details the thermostatic valve 10 in the closed position, where both the first valve assembly 8 and the second valve assembly 21 are in the closed position. Between temperatures of 113° F. and 117° F., first valve assembly 8 initializes the axial movement of first stopper 4 to begin the closing process of first outlet end 1 . However, if temperatures were to rapidly heat to 130° F. or higher while the first valve assembly 8 was in the closing process, second valve assembly 21 would rapidly close the second outlet end 20 by second stopper 47 to prevent further fluid flow into the first compartment 11 .
Alternatively, the first stopper 4 includes a plurality of weep holes 65 that allow the hot fluid to trickle out, as shown in FIG. 6 . Consequently, cold fluid is able to cycle in after the first valve assembly 8 is in the closed position. Such cold fluid will cool the temperature of the fluid in the first compartment 12 , so that the first temperature sensitive wax 43 will cool and contract, thereby causing the first valve assembly 8 to open first outlet end 1 . Likewise, the second stopper 47 includes a plurality of weep holes 66 that allow hot fluid to trickle out. Consequently, cold fluid is able to cycle in after the second valve assembly 21 is in the closed position. Such cold fluid will cool the temperature of the fluid in the second compartment 12 , so that the second temperature sensitive wax 44 will cool and contract causing second valve assembly 21 to open second outlet end 20 .
FIG. 7 and FIG. 8 illustrates one preferred embodiment of the thermostatic valve 10 removably attached to a shower head 31 . In FIG. 7 , the valve housing 9 includes a ball joint geometry end 22 that is rotatably mounted to a reciprocal ball joint geometry washer 26 . The reciprocal ball joint geometry washer 26 then removably is associated with retainer 27 , so that first outlet end 1 communicates with shower head second inlet end 34 . Fluid flow then departs through showerhead second outlet end 29 by a fluid spraying means 30 . Setting flow means 28 can also be associated with showerhead 31 .
FIG. 8 illustrates the assembly of thermostatic valve 10 within a showerhead assembly 32 . First spring 14 is inserted into the valve housing 9 in order to attach to the first outlet end 1 . First stopper 4 is inserted such that first spring 14 surrounds first stopper 4 which causes first stopper 4 to abut against first outlet end 1 , as shown in FIG. 7 . Next, first flange 15 is removably attached to the mid portion of valve housing 9 at a first shoulder 57 , as shown in FIG. 2 . Also, the first flange 15 includes first flange apertures 16 , which permit fluid to flow from first inlet end 2 to first outlet end 1 . Then, first thermostatic cylinder 7 is inserted so that the first cylinder body 55 abuts first flange 15 ; and, second spring 17 is inserted so that second spring 17 surrounds the first cylinder body 55 and biases first thermostatic cylinder 7 against first flange 15 . Second stopper 47 is inserted to abut and secure second spring 17 against the second end of first thermostatic cylinder 7 . Next, second flange 51 is inserted against a second shoulder 58 , seen in FIG. 3 , as to removably associate to second compartment 12 , also shown in FIG. 3 . Also, second flange 51 includes second flange apertures 52 that permit fluid to flow from second inlet end 19 to second outlet end 20 . Second thermostatic cylinder 53 is inserted to abut second flange 51 . Third spring 50 is inserted so that third spring 50 surrounds the second cylinder body 60 and abuts to spring catch insert 18 . Finally, coupling sleeve 37 and insert cap 39 attach the thermostatic valve 10 to a water supply.
FIG. 9 illustrates an embodiment where the thermostatic valve 10 in FIG. 7 is housed within a faucet assembly 38 . A faucet housing 36 includes a faucet housing inlet aperture 41 that is removably associated with first outlet end 1 , so that fluid can flow between a fluid supply 24 and a faucet housing outlet aperture 33 . The assembly of thermostatic valve 10 remains the same as described in the showerhead assembly 32 and showerhead 31 .
FIG. 10 illustrates a cross-sectional view taken along the line 1 - 1 and looking in the direction of the arrows. Valve housing 9 is situated so that first outlet end 1 operatively communicates with faucet housing inlet aperture 41 . The details of the first valve assembly 8 and second valve assembly 21 remain the same as described above.
In operation, the first valve assembly 8 starts to react at a first predetermined temperature; however, the first spring 14 is coiled to deter axial movement of first stopper 4 , as shown in FIG. 2 . The first thermostatic cylinder 7 is of the wax-filled or paraffin-filled type generally known in the art. The first thermostatic cylinder 7 is filled with a temperature sensitive wax 43 formulated to change from solid to liquid or from liquid to solid over a predetermined temperature range. As the temperature sensitive wax 43 changes state from solid to liquid, its volume increases. The increase in volume displaces the first piston 13 to extend outwards from the first piston housing 56 . Motion is transmitted from the first temperature sensitive wax 43 to first piston 13 in the first cylinder body 55 , as shown in FIG. 4 . First piston 13 axially engages the first stopper 4 , while the first thermostatic cylinder 7 remains stationary biased against first flange 15 . Subsequently, first stopper 4 abuts first outlet end 1 to preclude the flow of fluid out of first outlet end 1 . In FIG. 5 , the second thermostatic cylinder 53 responds to increases in temperature just as first thermostatic cylinder 7 described above.
Once the temperature of the temperature sensitive wax 43 drops below the predetermined temperature range, the temperature sensitive wax 43 volume decreases to enable first spring 14 to axially bias first stopper 4 to form first gap 5 . Thus, first valve assembly 8 is reset to enable the flow of fluid out of first outlet end 1 . The second valve assembly 21 responds to temperature decreases just as first valve assembly 8 described above. The first temperature sensitive wax 43 may be formulated to produce a solid to liquid transition over a 4° change in temperature. The first temperature sensitive wax 43 may also allow selection of the transition temperature over a predetermined range of 113° F. to 120° F.
The above has been provided for illustrative purposes only and is not intended to limit the scope of the invention of this application which is defined in the claims below. Accordingly, the description is provided for the purposes of teaching those skilled in the art the best mode for carrying out the invention
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A thermostatic valve incorporated within a plumbing system for regulating the flow of fluid. The thermostatic valve includes two valve assemblies operatively cooperating to preclude the flow of scalding water. The first valve assembly and second valve assembly respond to different fluid temperatures, as well as, over separate periods of time. The thermostatic valve can be incorporated in an “end-line” device such as a showerhead or faucet assemblies to create an “anti-scaled” plumbing fixture. The invention includes a valve housing having a first compartment and a second compartment, a fluid passageway, a first valve assembly, a second valve assembly, a first spring, a first stopper, a first flange, a first-thermostatic cylinder, a second spring, a second stopper, a second flange, a second thermostatic cylinder, and a third spring.
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CROSS-REFERENCE
This is a National Phase Application filed under 35 U.S.C. 371 of International Application No. PCT/IL2005/000088, filed on Jan. 25, 2005, claiming the benefit under 35 USC 119(e) of U.S. Provisional Patent Application No. 60/539,101, filed on Jan. 27, 2004, the entire content of each of which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention relates to brominated polymers, dispersions thereof, and uses of such polymers and dispersions.
BACKGROUND OF THE INVENTION
It is known in the art to include bromine-containing additives in articles such as fabrics, coatings, and adhesives, in order to render them fire-retardant. If such additives are of small molecular weight, and not chemically bond to the matrix, they might diffuse out of the product (especially if the product is frequently washed, like in the case of fabrics), and fire retardancy decreases. Furthermore, the drainage of manufacturers and users of such products may contain brominated additives, which might cause environmental problems.
One object of the present invention is to provide novel brominated substances that may be used as additives for rendering an article fire retardant. Other objects will be made clear to the reader from the following description and claims.
RELATED ART
The following publications may be helpful in understanding the background of the invention. An appearance of a publication under this title, however, should not be construed as applying that the publication is relevant to the patentability of the invention.
1. US patent application publication no. 2002/24042, describing dispersions and terpolymers of PBBMA; 2. U.S. Pat. No. 5,072,028, describing a process for the preparation of PBBMA and related compounds; 3. U.S. Pat. No. 4,728,463, describing brominated styrene-maleate copolymers; 4. U.S. Pat. No. 4,412,051, describing fire resistant copolymers of bromostyrene and another monomer, preferably, acrylonitrile; 5. U.S. Pat. No. 5,290,636 describing flame retardant latex coatings, which comprise copolymers of ring-halogenated aromatic monomer units, alkyl acrylate/methacrylate monomer units, and optionally another monomer unit; and 6. U.S. Pat. No. 5,276,091 describing polymeric compositions wherein a base polymer is blended with a stable interpolymer prepared by compolymerizing a brominated monovinyl aromatic monomer, a methacrylic acid ester and, optionally, an ethlenically unsaturated nitrile.
SUMMARY OF THE INVENTION
The present invention provides a copolymer made of at least one bromine-containing monomer, and at least one other monomer. Bromine containing monomers included in the copolymer of the invention are of the formula A-B-C wherein A is a phenyl, substituted with 3-5 bromine atoms, B is a C 1 -C 4 alkyl, optionally substituted with 1-8 bromine atoms, and C is an acrylic or methacrylic group. The copolymer of the invention is characterized in having bromine contents of at least 20%. All the concentrations expressed herein by % refer to w/w percentage, unless otherwise is indicated.
The group A defined above may be substituted with 3, 4, or 5 bromine atoms, where 5 is most preferable. Independently, the group B is a lower alkyl, which may have 1, 2, 3, or 4 carbon atoms, each of which may independently have none, 1, or 2 bromine substituents.
Some examples for brominated monomers in accordance with the present invention are tri, tetra, and penta bromo benzyl acrylate, tri, tetra, and penta bromo benzyl methacrylate, tri, tetra, and penta bromo phenyl ethyl (meth)acrylate, tri, tetra, and penta bromo phenyl mono-, di-, tri-, or tetra-bromo ethyl (meth)acrylate, tri, tetra, and penta bromo phenyl mono-, di-, tri-, tetra-, penta-, or hexa-bromo propyl (meth)acrylate, and tri-, tetra-, or penta-bromo phenyl mono-, di-, tri-, tetra-, penta-, hexa-, septa-, or octa-bromo butyl (meth)acrylate. Penta bromo benzyl acrylate will be referred to hereinafter as PBBMA.
The polymer of the invention includes monomers of at least two different structures, and therefore, may also be named copolymer. Thus, the terms polymer and copolymer are used herein interchangeably.
According to one embodiment the polymer of the invention has bromine contents of 60-70%, according to another embodiment the bromine contents is between 25 and 50%, and according to another embodiment 20-35%. Polymers of different bromine percentage may be useful for different applications and corresponding flame retardancy (FR) standards.
Additionally to the bromine containing monomer, a polymer according to the present invention has at least one non-brominated monomer, which may be a specialty monomer, or a non-specialty monomer.
Non-limiting examples of functions that may be attributed to specialty monomers include cross-linking, surface active, or adhesion promoting. In some cases, a single specialty monomer may have more than one function, for instance, N-methylol acryl amide functions both as a surfactant and as an adhesion promoter, which improves the adhesion of the polymer to textiles. Non-limiting examples of specialty monomers that may be used according to the invention are sodium salt of 2-acrylamido-2-methyl propane sulphonic acid, betal-carboxymethyl acrylate, ammonium allyloxypolyethoxy(10)sulphate, laurethoxy(23)methacrylate, laurethoxy(25)methacrylate, allyl methacrylate, hydroxyl ethyl methacrylate. glycidyl methacrylate, ammonium salt of α-sulfo-ω-[1-(Alkoxy)methyl-2-(2-propenyloxy)ethoxy]-ω-hydro-poly(oxy-1,2,-ethanediyl), ammonium salt of α-[1-(Alkoxy)methyl-2-(2-propenyloxy)ethoxy]-ω-hydro-poly(oxy-1,2,-ethanediyl), Ditrimethylolpropane tetraacrylate, Ethoxylated trimethylolpropane triacrylate, and Trimethylolpropane triacrylate. Such specialty monomers are sold under trade names such as AMPS2405 (manufactured by Lubrizol), Beta C, DVP-010, Lem 23, Lem25 (all by Bimax Inc.), HEMA (by Laporte), Akeda Reasope SR-10, Akeda Reasope SR-20, Akeda Reasope SR-30, all by Asahi Denka, and SR355, SR454, SR351 (all by Cray Vally).
Non-limiting examples of non-specialty monomers that may be used according to the present invention are acrylic monomers, vinyl acetate, styrene, and styrene derivatives such as α-alkyl styrene, and particularly α-methyl styrene.
Preferable acrylic monomers are acrylamide, acrylic acid, methacrylic acid, acrylonitrile, butyl acrylate, ethyl acrylate, 2-ethyl hexyl acrylate, and methyl methacrylate.
A polymer according to the invention is typically made of between two and six different monomers. When very high bromine content is desirable, the non-brominated monomers are typically specialty monomers.
A specific group of monomers useful according to the present invention are of acrylic structure, namely, monomers of the formula R 1 CH═CR 2 C(O)A, wherein
A is selected from the group consisting of OR 3 , NR 3 R 4 , and CN; and
R 1 , R 2 , are each independently selected from H or alkyl, said alkyl being linear or branched, and each of R 3 and R 4 independently may be H, alkyl, alkenyl, alkoxy, polyalkoxy, alkanol, or ether, each of which may be linear or branched, substituted or unsubstituted. As may be apparent from the examples given below, the carbon-containing R groups (namely, those groups of R 1 , R 2 , R 3 , and R 4 that contain carbon) have usually between 1 and 15 carbons, although some of them may at times contain more carbon atoms. The alkyl R groups are typically of 1-4 carbon atoms.
Among the above mentioned acrylic monomers, those with R 3 or R 4 other than alkyl are typically specialty monomers.
According to another aspect of the present invention, there is provided an aqueous polymeric dispersion of a bromine-containing polymer, wherein the solid content in said dispersion is at least 40%, typically 40-65%, most typically 40-55%.
The term dispersion is used herein to refer to solid particles dispersed in liquid medium. In a dispersion, the particles do not agglomerate, at least on a time scale of practical interest, and this is usually achieved by including therein suitable surface active agents. According to the invention, two or more surface active agents are usually required.
Surface active agents, surfactants, emulsifiers, and dispersants, are all terms that are used herein interchangeably.
It should be noted that it is preferable to use such surfactants that are useful in all the stages of the polymerizing procedure, starting with stabilizing a dispersion of the brominated monomer, through stabilizing pre emulsion or pre dispersion and allowing efficient polymerization reaction between the different monomers, and ending with stabilizing the polymeric aqueous dispersion obtained eventually. This complicated task is usually accomplished in accordance with the present invention by two or more surfactants. Surfactants that were found by the inventor to be most suitable according to the present invention are nonionic and/or anionic surfactants. Among the nonionic surfactants, alkyl phenol based surfactants are particularly useful. It should be noted, that some countries tend to limit the use of alkyl phenols, since these compounds are suspected as being non-friendly to the environment and to human health. Therefore, substitutes to alkyl phenols are being developed, and such substitutes are expected to be also very useful in accordance with the present invention.
Of the anionic surfactants, of most particular interest are alkyl aryl based, such as alkyl aryl sulphonic acid or alkyl aryl sulphonate.
Non-limiting examples to liquid mediums in which a brominated copolymer may be dispersed in accordance with the present invention are water, glycols, and mixtures thereof.
Preferably, the bromine-containing polymer, which is dispersed in the dispersion of the invention, has a bromine content of at least 20% (w/w), and is in accordance with the first aspect of the invention, as described above.
Typically, the aqueous polymeric dispersion has a high density (comparing to commercial acrylic polymers), of above 1.2 g/cc, usually between 1.2 and 1.7 gr/cc, which makes it difficult to stabilize its aqueous dispersion. The dispersion is stabilized by surfactants, and usually by a combination of two or more surfactants, each of which may be reactive (i.e. become part of the polymer chain) and/or non-reactive (i.e. remain as independent substance in the dispersion).
Preferable aqueous polymeric dispersions according to the invention have a particle size of 2000 nm and smaller, preferably between 50 and 1000 nm, more preferably between 80 and 400 nm. Typically, the molecular weight of polymers according to the invention is 500,000 and above, preferably above 1,000,000.
Polymeric aqueous dispersions according to the invention proved to be stable for at least six months at 5-35° C. without direct sunlight. Conventional additives, such as propylene glycol may extend this temperature range to about −70°-+35° C.
According to another aspect thereof, the present invention provides fire-retardant products comprising a bromine-containing polymer together with antimony-oxide (hereinafter AO). The AO is usually added to the aqueous polymeric dispersions in methods known in the art per se, namely, as commercially available dispersion, added to the final dispersion after its stabilization. Nevertheless, the invention also encompasses products and dispersions that include AO, which was added in other manners. One non-limiting example for such products is a dispersion wherein the AO is added during polymerization stage, as demonstrated in Example 12 below. Preferably, the bromine-containing polymer, dispersed in the dispersion that renders the products of the invention fire retardant, has a bromine contents of at least 20% (w/w) and is by itself in accordance with the first aspect of the present invention.
In the context of the present application and claims a product is considered fire retardant if it meets international standards, such as standard CFR16/1615 for fabrics, standard-ASTM D3806 for paints, and standard ASTM D2859, BS 476-7, DIN 4102-1, ISO1182 for building materials.
Non-limiting examples to products according to the invention are textiles, non-woven fabrics, paints, coatings, and adhesives.
In case of textiles according to the invention, polymers of the invention may be applied thereto mainly by means of topical application of a dispersion according to the invention or impregnation of such dispersion into the treated textile. Methods for topical application include, for instance, spraying, padding, or printing. Since these methods (including impregnation are commonly used in the textile industry, the present invention does not require any unique production line dedicated to the treatment of the textiles to make them fire retardant.
Another advantage that may be associated with the use of textiles according to the invention is that the drainage of the manufacturing facility as well as that of the users does not contain free bromine compounds.
Many textiles are designed to be hydrophobic, in order to retain their color strength, to allow them to remain stain free, and to eliminate water penetration through the textile. The present invention is suitable for such applications, especially if a polymer with a non-brominated hydrophobic monomer is used. Non-limiting examples of monomers to be used for obtaining a hydrophobic fire retardant textile according to the invention are butyl Acrylate, 2-ethyl hexyl acrylate, and styrene.
Typically, polymers in accordance with the invention have Tg of between −20° C. and 70° C. It is interesting to note that according to the invention it is also possible to obtain polymers with Tg lower than 0° C. This may be achieved by using polymers with non-brominated monomers having a low Tg, of typically lower than 0° C., which results in a soft hand fire retardant textile that is out of reach of most state of the art methods. Non-limiting examples of monomers with Tg lower than 0° C. are butyl Acrylate, ethyl Acrylate, and 2-ethyl hexyl acrylate. Another advantage that may be associated with textiles that are made fire retardant in accordance with the present invention is that they remain transparent without affecting the final color of the textile. However, such transparency is typically obtained only in such textiles that were treated with dispersions according to the invention that had a particle size of between about 100 and about 350 nm.
Similar advantages may be obtained also by applying the dispersion or polymer of the invention to non-woven fabrics. Furthermore, in case of non-woven materials, these may be made by the chemical bond method, in which case, a polymer in accordance with the present invention may be used for chemically bonding fibers of the non-woven fabric and at the same time rendering said fabricfire-retardant.
Naturally, non-woven fabrics may also be made fire retardant by topically applying to them a dispersion according to the invention, for example, by printing, spraying, and the like, or by impregnation.
Non-woven articles may frequently benefit from having a soft, non-fragile structure. This may be obtained with polymers of the invention, wherein the non-brominated monomer is of a low Tg, preferably, lower than 0° C. Non-limiting examples to such monomers are butyl acrylate, ethyl acrylate, and 2-ethyl hexyl acrylate.
Regarding to paints, coatings and adhesives, since these are typically water-based acrylics, the dispersion of the present invention may easily be made compatible with such products, do not shorten their shelf life, neither adversely affects their effectiveness.
According to another of its aspects, the present invention provides a method for obtaining an aqueous dispersion of a co-polymer containing at least a first monomer and a second monomer, wherein said second monomer is at least partially dissolved in said first monomer, and reacts to polymerize therewith in the presence of water surfactants; the method being characterized in that the first monomer is a brominated aromatic compound.
Preferences for the first monomer in accordance with this aspect of the invention are the same as for the brominated monomer in accordance with the other aspects of the invention.
The second monomer is preferably styrene or a derivative thereof, such as α-alkyl stryerne.
According to one embodiment, the method comprising:
(i) dissolving said first monomer in a first liquid to obtain a solution, wherein said first liquid includes said second monomer optionally together with surfactants; (ii) mixing said solution with water and optionally also with surfactants to obtain a stable emulsion comprising water, surfactants, and said first monomer; and (iii) reacting said stable emulsion with an initiator to obtain an aqueous dispersion of a polymer containing at least said first monomer and said second monomer.
According to one embodiment, the first liquid does not include surfactants, and these are added only in (ii). Preferably, this method of the invention is utilized to obtain an aqueous polymeric dispersion in accordance with the invention (i.e. at least 40% solid content, etc.), and the polymer dispersed therein is also in accordance with the invention (at least 20% bromine content, etc.)
One embodiment of particular interest is where at least one of the surfactants is reactive, and the obtained polymer contains it in the polymeric chain.
Another embodiment of particular interest is a method as described herein, wherein the first and second monomers react with at least one other monomer, such that the polymer obtained by the method is a copolymer of the first monomer, the second monomer, and this at least one other monomer. All non-brominated monomers mentioned in relation to the other aspects of the invention may be useful in this embodiment.
It should be noted that the solution of the first monomer dissolved in the second monomer is not necessarily clear, and may include non-dissolved particles of the first monomer. However, usually, the solution is prepared to appear clear to the naked eye.
According to another aspect of the present invention there is provided a method for obtaining an aqueous polymeric dispersion having a polymeric particles of a first size, by reacting a dispersion of monomers having particles of a second size, wherein said second size is larger than said first size, comprising: reacting said dispersion with a mixture comprising said other monomers, and stirring the reaction mixture at about 200-300 rpm and adding reactive substances to the mixture at a rate of between 1 and 10 ml per minute, while keeping the temperature at about 70-90° C.
DETAILED DESCRIPTION OF THE INVENTION
In order to understand the invention and to see how it may be carried out in practice, several exemplary embodiments will now be described, by way of non-limiting example only. In all these examples, the order of adding the various ingredients may be of crucial importance.
In particular, presented here is a list of substances that were used by the inventor for carrying out the invention in accordance with the following examples. The invention is not limited to the substances listed herein, however, they should suffice for carrying out the following examples.
In this regard, it should be noted that some of the surfactants listed below are commercially available when they are water-diluted. In other cases, the user should dilute them in water before use. When the inventor diluted a surfactant from the list below in order to use it in accordance with the invention, the used dilution is mentioned in the list. Amounts mentioned in the Examples below are always of diluted surfactants.
List of Useful Substances
General
PBBMA—pentabromo benzyl acrylate. (FR-1025M. Dead Sea Bromine Group).
APS—Ammonium Per Sulphate—(Degussa, Caldig, Stan Chem)
Formosul—Sodium Formaldehyde Solphoxylate dihydrate (Stan, Transpek-silox)
TBHP—tert-Butylhydroperoxide 70% (Peroxide Chemie, Witco)
Nyacole 1550—Antimony pent oxide dispersion. (Nyacol Nono)
Nyacole 1540N—Antimony pent oxide dispersion. (Nyacol Nono)
Nyacole 1550PH7—Antimony pent oxide dispersion. (Nyacol Nono)
Surface Active agents: Aerosol OT75—Sodium Dioctyl sulphosuccinate in ethanol/water (Cytec)
NP6—Nonyl Phenol+6 Ethylene oxide (Sasol)
NP9—Nonyl Phenol+9 Ethylene oxide (Sasol)
Synperonic NP10—Nonyl Phenol+10 units of Ethylene oxide (Uniqema)
Synperonic NP12—Nonyl Phenol+12 units of Ethylene oxide (Uniqema)
Synperonic NP10—Nonyl Phenol+10 units of Ethylene oxide (Uniqema)
Synperonic NP17—Nonyl Phenol+17 units of Ethylene oxide (Uniqema)
NP20—Nonyl Phenol+20 units of Ethylene oxide (Sasol)
NP30—Nonyl Phenol+30 units of Ethylene oxide (Sasol)
Synperonic NP40—Nonyl Phenol+40 units of Ethylene oxide (Uniqema)
Otix40—Octyl phenol ethoxylate (Condea)
Emulgaten CO 55—Alkyl polyglycol ether (Condea)
Emulgante AS25—Alkyl polyglycol ether (Condea)
Byk190—Sol. Of a polyfunctional polymer with anionic/nonionic character (Byk chemia)
Byk 380—Dipropylene glycolmethyl ether (Byk chemia)
Byk 154—Ammonium acrylate copolymer (Byk chemia)
Zoropol SLS—Sodium lauryl sulfate (Zohar detergent Factory)
Zoropol AN—Ammonium nonoxynol 9 sulphate (Zohar detergent Factory)
Labs60—Sodium Alkylbenzene sulfonate (Zohar detergent Factory)
Labs100—Dodecylbenzene sulphonic acid (Zohar detergent Factory)
Solsperse 44000—(Avecia)
Ethylan Co-55—Cethyl-Oleyl Alcohol Ethoxylate (Akcros)
Imbentin U60—Branch oxo alcohol C11+6 ethylene oxide (Dr. Kolb)
Lutensol AT80—Fatty alcohol ethoxylated. (BASF)
Antifoam:
Antifoam—Blend of hydrocarbon & nonionic (Stockhausen)
Foamaster 3082—fatty acid ester and salts in hydrocarbons alkylate (Nymco)
Darpo 2162—(Elementis)
Moussex 3029 HL—(Synthron)
Foamaster 50—(Cognis)
Special Monomers:
N-Methylol Acryl amide—N-(Hydroxymethyl)Acrylamide (our synthesis product)
Glycidyl Methacrylate—(Dow)
AMPS2405—2-acrylamido-2-methyl propane sulphonic acid, sodium salt (Lubrizol)
Beta C—Beta-carboxyethyl acrylate (Bimax)
DVP-010—Ammonium allyloxypolyethoxy(10) Sulfate (Bimax inc.)
Lem 23—Laurylethoxy (23) methacrylate (Bimax)
Lem 25—Laurylethoxy (25) methacrylate (Bimax)
Allyl Methacrylate—(Shinwa trading)
HEMA—Hydroxy ethyl methacrylate (Laporte)
ADEKA Reasoap SR-10—(Asahi Denka)
ADEKA Reasoap E20—(Asahi Denka)
ADEKA Reasoap ER30—(Asahi Denka)
Mono&Di&Tri&Highly functional monomer and oligomer acrylate (Cray Vally)
Marlon AS—Alkylbenzene sulphonic acid (Condea)
Marlon A—Alkylbenzene sulphonate sodium salt (Condea)
DISPONIL FES 32—Fatty alcohol poly glycole ether sulphate, sodium salt
Disponil AES 72—Alkyl Aryl Polyglycole ether Sulphate sodium salt
Biocides:
Acticide SPX—5-chloro-2-methyl-2H-isothiazol-3-one+methyl-2H-isothiazol-3-one (THOR).
Acticide GR—2,2′,2″-(hexahydro-1,3,5-triazine-1,3,5-triyl)triethanol (THOR) (May be Mergal KM200 of Troy).
Acticide MBS—Combination of 1,2-benzisothiazol-3(2H)-one+2-methyl-2H-isothiazol-3-one (THOR)
Acticide FS—methylisothiazolones and Formaldehyde donors(THOR)
Nipacide OPG—N-octylisothiazolinone (Nipa Labratories)
Rheological Modifiers:
Carbopol 846—(BFGoodrich)
Prox AM162—Aqueous emulsion of an acrylic copolymer (Synthron)
Commercial Monomers:
Acrylamide—(Cytecs, Stan Chem)
Acrylic Acid—(Atochem)
Acrylonitrile—(DSM)
Butyl Acrylate—(Rohm&Haas, Basf, Atochem)
Ethyl Acrylate—(Rohm&Haas, Basf, Atochem)
2-Ethyl Hexyl Acrylate—(Hoechst, Nippon, Basf)
Methyl Methacrylate—(Deggusa, Basf, Atochem)
Styrene—(Gadot)
EXAMPLES
In all the following examples, where addition of AO is not described, it may be added to the final dispersion with short mixing.
Example 1
This example shows how to obtain a copolymer of PBBMA, acrylic acid, N-methylol acryl amide, acrylo nitrile, butyl acrylate, and methyl methacrylate. Such a copolymer was obtained according to this example, and was found to include 32% (w/w) bromine. The aqueous solution obtained in accordance with this example had a 45% solids content with typical particle size of 475 nm and viscosity of 3580 cps (Brookfield, LVT, spindle 3, 12 rpm).
In this example the aqueous polymeric dispersion is obtained from a PBBMA dispersion and an emulsion of the other monomers. Monomers and polymerizing agents are fed simultaneously.
Preparation of the PBBMA dispersion: To a 2-liter round bottom flask, fitted with mechanical stirrer, add 450 gr water and about 150-200 gr of diluted dispersing agents. The dispersing agents should be a combination of an anionic surfactant and a non-ionic surfactant in weight ratio of 1:1. The non-ionic surfactant is to be an alkyl phenol based dispersing agent with a Low HLB, of about 7-11.
After short mixing an emulsion is obtained. Add slowly to the emulsion, 400 gr of commercial PBBMA powder (FR1025M, average particle size of 5-8 micron), and 1 gr biocide (in this order). The obtained dispersion should then be mixed for another 10 minutes.
Grind the dispersion until the particle size is about 600-1500 nm. This may be done with High Sheer Homogenizer, such as IKA Ultraturax T-50, operated for about 20 minutes followed by additional 3 cycles of grinding process with pearl mill such as Dyno mill, to obtain the required size. All grinding should be carried out while temperature is observed not to raise over 30° C. After grinding, PH should be adjusted to 7-8.
Pre-emulsion: To a 1 liter round bottom flask, fitted with mechanical stirrer, add about 70 gr water and 3-8 gr of anionic surfactant. After 5-10 min stirring at about 250 rpm, add slowly, one by one, and with continuous stirring, the following ingredients: 2-6 gr acrylic acid, 15-40 gr N-methylol acryl amide (45% solids), 15-30 gr acrylonitrile, 80-110 gr butyl acrylate, 40-70 gr methyl methacrylate and about 15 gr water. The obtained pre emulsion should be mixed for another 15 minutes.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, 2 dropping funnels and Nitrogen inlet, add about 120 gr water, 0.5 gr sodium bicarbonate and 0.5 gr sodium carbonate. Hot water should be passed through the jacket, to warm the solution up to 80-82° C. Continuous stirring (200-300 rpm) should be applied. Nitrogen is to be introduced under the surface of the liquid for about 10 min. First initiator solution, made by dissolving 0.5 gr APS in 5 gr water, is then added. 5 min later, 10-20 gr of the pre-emulsion described above is to be added. Few minutes later, when no change in Temp is observe, the rest of pre emulsion is to be slowly added through one dropping funnel (this should take about 3.5 hours). 500 gr of the PBBMA dispersion described above should then be added, through the second dropping funnel, drop wise. This takes about 1.5 hours. A main initiator solution, prepared by dissolving 1.8-3 gr APS and 1 gr ammonia in 40 gr water is added through a separate dropping funnel, during both pre emulsion and dispersion addition. Temperature should be kept at 80-82° C. during the entire procedure. About 4 hours from the beginning of the polymerization, raise the temperature to 85° C., and stir the dispersion obtained for another 45-55 min. Lower the temperature to 65° C., and add a solution of 1.4 gr TBHP in 4 gr water. After 5 min, add a solution of 0.9 gr Formosul in 8 gr water, cool the dispersion to room temperature, and add 2 gr Ammonia, 10-20 gr of dispersing agent and about 3 gr biocide with constant stirring. The dispersing agent should be of the alkyl phenol type, with HLB value of between about 13.
Example 2
In this example, obtained is a copolymer of PBBMA, acrylic acid, N-methylol acryl amide, and butyl acrylate. Aqueous dispersions obtained in accordance with this examples had about 46-47% solid content, where the solids are 32% bromine. In two repetitions the particle sized varied from 134 to 154 nm, and with it the viscosity changed from 1580 to 3060 cps (Brookfield, LVT, spindle 3, 12 rpm).
A textile impregnated with this dispersion (after addition of the antimony penta-oxide dispersion) to a pick up of 25.8% was found to be fire retardant in accordance with the standard cited above. Antimony penta-oxide was added in the form of dispersion, sold under the trade name NyacolA1550, in concentration of 18.5 gr per 100 gr polymeric dispersion
Here, a pre-dispersion of PBBMA with the other monomers is first prepared from the PBBMA dispersion described above, mixed with the other monomers and suitable surface active agents, and then this pre-dispersion is polymerized.
Pre-dispersion: To a 1 liter round bottom flask, fitted with mechanical stirrer, 500 gr of the described PBBMA dispersion is added together with 3-8 gr of surfactant combination, made of two surfactants, one being anionic, and the other non-ionic with high HLB of about 14-18. The weight ration between the anionic and non-ionic surfactants should be 2:1. Also added to the dispersion, slowly, with continuous stirring, and in the following order are 1-5 gr acrylic acid, 15-40 gr N-methylol acryl amide (45% solids), 165-200 gr butyl acrylate and 15 gr water. This leads to the formation of a stable pre dispersion that should be stirred for another 15 minutes.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, dropping funnel and Nitrogen inlet, one should add 220 gr water, 0.05-0.5 gr of the non-ionic surfactant used in the combination mentioned above, and 0.5 gr Ammonia. Hot water is to be passed through the jacket, to warm the solution up to 80-82° C. Continuous stirring (200-300 rpm) should be applied. Nitrogen is introduced under the surface of the liquid for 10 min. First initiator solution, made by dissolving 0.5 gr APS in 5 gr water, is to be added, and 5 minutes later, the pre emulsion is to be added through the dropping funnel, drop wise, over 4 hours. Main initiator solution, prepared by dissolving 1-3 gr APS and 0.5 gr ammonia in 40 gr water is added as well, simultaneously with the pre dispersion. Temperature should be kept at 80-82° C. during the procedure. After 4 hours, temperature is to be allowed to raise to 85° C., and the dispersion is stirred for another 45-55 minutes. The temperature is then lowered to 65° C., and solution of 0.5 gr TBHP in 5 gr water is added. After 5 min, solution of 0.3-2 gr Formosul in 5 gr water is added. The dispersion is cooled to room temperature, and 0.5 gr anti-foam and 2 gr biocide should be added with stirring.
Example 3
This example teaches how to obtain a copolymer of the same monomers as in Example 2, however, in the present example, the dispersion obtained has somewhat lower solid content of 41%, and significantly lower viscosity, of only 62 cps (Brookfield, LVT, spindle 1, 60 rpm). The particle size was measured to be 116 nm and the bromine content was 30.6%.
This example uses a PBBMA dispersion as described under example 1 above, and a pre-emulsion with the other monomers. The dispersion, pre-emulsion and main initiator were added all simultaneously.
Pre-emulsion: To a 1 liter round bottom flask, fitted with mechanical stirrer, add 130 gr water and 1-5 gr of a surfactant combination. This combination is like the one used in example 2, but the weight ratio between the anionic and non-ionic surfactants is 4:1, rather than 2:1 used in example 2. After 5-10 min stirring at 250 rpm add slowly, with continuous stirring, and in the following order: 1-5 gr acrylic acid, 15-40 gr N-methylol acryl amide (45% solids), 140-170 gr butyl acrylate and 15 gr water. The stable pre emulsion thus obtained is to be stirred for additional 15 minutes.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, 2 dropping funnels and Nitrogen inlet, add 168 gr water, and 0.5 gr Ammonia. Hot water should be passed through the jacket, to warm the solution up to 80-82° C. Apply continuous stirring (200-300 rpm). Introduce nitrogen under the surface of the liquid for 10 min. Add a first initiator solution, made by dissolving 0.5 gr APS in 3 gr water. After 5 minutes add the pre emulsion through one dropping funnel and 440 gr of PBBMA dispersion, described above, through the second dropping funnel. Add the dispersion and pre-emulsion simultaneously drop wise, over 4 hour. Prepare a main initiator solution by dissolving 1-3 gr APS and 0.5 gr ammonia in 40 gr water, and add them as well, simultaneously with both dispersion and pre emulsion. Temperature must be kept at 80-82° C. during the procedure. After 4 hours, temperature should be raised to 85° C., and the dispersion stirred for another 45-55 min. The temperature should then be lowered to 65° C., and solution of 1-3 gr TBHP in 5 gr water be added. After 5 min, add solution of 0.3-2 gr Formosul in 5 gr water. Cool the thus obtained dispersion to room temperature, and add with stirring 2 gr Ammonia and 2 gr biocide.
Example 4
Preparation of copolymer of PBBMA, butyl acrylate and acrylic acid. The example allows obtaining a polymeric aqueous dispersion with a solids content of about 40% and bromine content of about 52%, which is also characterized by exceptionally small particle size of 87 nm, with exceptionally low viscosity of 12 cps (Brookfield, LVT, spindle 1, 60 rpm).
PBBMA dispersion: To a 2-liter round bottom flask, fitted with mechanical stirrer, add 450 gr water and 50-80 gr of a dispersing agents combination. This combination should be a 1:1 combination of an anionic and nonionic surfactant. After short mixing, add slowly about 480 gr of commercial PBBMA powder (FR1025M, average particle size of 5-8 micron) and follow it by adding 1 gr biocide. Mix the obtained dispersion for another 10 minutes. Grind the dispersion with High Sheer Homogenizer such as IKA Ultraturax T-50, for 20 min while keeping temp max 30° C. Transfer the dispersion for additional 3 cycles of grinding with pearl mill, such as Dyno mill, until having particle size of 600-1500 mn. Adjust the PH to 7-8.
Solution: To a 1 liter round bottom flask, fitted with mechanical stirrer, add slowly, one by one in the given order 50-100 gr butyl acrylate, 1-5 gr acrylic acid and 1-5 gr of an alkyl aryl sulphonic acid.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, 2 dropping funnels and Nitrogen inlet, add 140 gr water, 1 gr of a nonionic high HLB alkyl phenol based surfactant and 0.6 gr Ammonia. Hot water should be passed through the jacket, to warm the solution up to 80-82° C. Continuous stirring at 200-300 rpm should be applied. Introduce nitrogen under the surface of the liquid for 10 min, and then add a first initiator solution, made by dissolving 0.5 gr APS in 3 gr water. 5 min later, add drop wise, over 5 hours, the solution through one dropping funnel simultaneously with adding through the second dropping funnel a mixture of 700 gr of the PBBMA dispersion described above and 15-40 gr N-Methylol Acryl Amide. Still simultaneously, add a main initiator solution, prepared by dissolving 1.5 gr APS, 1-3 gr nonionic high HLB alkyl phenol based surfactant and 0.5 gr ammonia in 30 gr water. Temperature should be kept at 80-82° C. during the procedure. After 5 hours, temperature should be raised to 85° C., and the dispersion should be mixed for another 45-55 min. The temperature is then lowered to 65° C., and solution of 0.5 gr TBHP in 5 gr water is added. After 5 min, solution of 0.35 gr Formosul in 5 gr water is added. The dispersion is then let to cool to room temperature, and 0.5 gr antifoam and 2 gr biocide are to be added while stirring.
Example 5
Preparation of copolymer of PBBMA, butyl acrylate, 2-ethyl hexyl acrylate and acrylic acid. The example allows obtaining a polymeric aqueous dispersion with a solids content of about 46% and bromine content of 20%, which is also characterized by low Tg value of −12° C. (calculated), particle size of 186 nm, with viscosity of 860 cps (Brookfield, LVT, spindle 3, 12 rpm).
PBBMA dispersion: To a 2-liter round bottom flask, fitted with mechanical stirrer, add 360 gr water and 40-55 gr of a 1:1 combination of low HLB alkyl phenol based nonionic dispersing agent and anionic surfactant. After short stirring, add slowly 490 gr of commercial PBBMA powder (FR1025M, average particle size of 5-8 micron) and 8 gr antifoam, followed by 1 gr biocide. Stir the obtained dispersion for another 10 minutes. Grind the obtained dispersion with High Sheer Homogenizer, such as IKA Ultraturax T-50 for 20 minutes while keeping the temp at maximum 30° C. Transfer the ground dispersion for 3 additional grinding cycles with pearl mill (Dyno mill), until a particle size of 600-1500 nm is obtained. Adjust the PH to 7-8.
Pre-dispersion: To a 1 liter round bottom flask, fitted with mechanical stirrer, add 3-8 gr of surfactant combination, made of two alkyl phenol based surfactants, one being anionic, and the other non-ionic with high HLB of about 14-18. The weight ration between the anionic and non-ionic surfactants should be 2:1. Also add to the dispersion, slowly, with continuous stirring, and in the following order 1-5 gr acrylic acid, 15-40 gr N-methylol acryl amide (45% solids), 140-200 gr butyl acrylate, 140-200 gr 2 ethyl hexyl acrylate and 15 gr water. This leads to the formation of a stable predispersion, that should be stirred for another 15 minutes.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, 2 dropping funnels and Nitrogen inlet, add 202 gr water, 0.05-2 gr of a nonionic high HLB alkyl phenol based surfactant and 0.5 gr Ammonia. Hot water should be passed through the jacket, to warm the solution up to 80-82° C. Continuous stirring at 200-300 rpm should be applied. Introduce nitrogen under the surface of the liquid for 10 min, and then add a first initiator solution, made by dissolving 0.5 gr APS in 3 gr water. 5 min later, add drop wise, over 5 hours, the pre dispersion through one dropping funnel simultaneously with adding through the second dropping funnel 265 gr of the PBBMA dispersion described above. Still simultaneously, add a main initiator solution, prepared by dissolving 1-3 gr APS and 0.5 gr ammonia in 40 gr water. Temperature should be kept at 80-82° C. during the procedure. After 5 hours, temperature should be raised to 85° C., and the dispersion should be mixed for another 45-55 min. The temperature is then lowered to 65° C., and solution of 1-3 gr TBHP in 5 gr water is added. After 5 min, solution of 0.3-2 gr Formosul in 5 gr water is added. The dispersion is then let to cool to room temperature, and 0.5 gr antifoam and 2 gr biocide are to be added while stirring.
Example 6
A PBBMA-alkyl methacrylate copolymer with 68% bromine, viscosity of 20 cps, solid content of 41.5% and particle size of 100 nm.
PBBMA dispersion: Prepare as in the previous example.
Prepare a solution by dissolving 2-8 gr of low HLB nonionic dispersing agent, the same weight of anionic surfactant and 1-4 gr thickening agent in 100 gr Water.
Prepare a semi-final PBBMA dispersion by mixing the above dispersion and solution in 9:1 w/w proportions.
Final Dispersion: To a 1 liter round bottom flask, fitted with mechanical stirrer, add slowly, with continuous stirring, 800 gr of the above semi-final PBBMA dispersion and 0.05-3 gr Allyl Methacrylate.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, dropping funnels and Nitrogen inlet, add 130 gr water, 1-4 gr high HLB nonionic surfactant and 0.6 gr Ammonia. Let hot water pass through the jacket, to warm the solution up to 80-82° C. with continuous stirring at 200-300 rpm. Introduce nitrogen under the surface of the liquid for 10 min. Five minutes later add a first initiator solution, made by dissolving 0.5 gr APS in 3 gr water. Another 5 min later, add the final dispersion through the dropping funnel, drop wise, over 4.5 hour. Add a main initiator solution, prepared by dissolving 1-3 gr APS, 0.1-2 gr high HLB nonionic surfactant and 0.5 gr ammonia in 30 gr water simultaneously with adding both the dispersion and pre emulsion. Keep temperature at 80-82° C. during the procedure. After 4.5 hours, raise the temperature to 85° C., and mix the dispersion for another 45-55 min. Let the temperature cool to 65° C., and add a solution of 1-3 gr TBHP in 5 gr water. After 5 min, add a solution of 0.3-2 gr Formosul in 5 gr water. Let the dispersion cool to room temperature, and add with stirring 0.5 gr antifoam and 2 gr biocide.
Example 7
Another recipe for a copolymer and aqueous dispersion containing it is given in the present example. The polymer obtained by the inventor in accordance with this example contained 50.6% solids, and had a viscosity of 16200 cps (Brookfield, LVT, spindle 4, 12 rpm). The polymer particle size was measured to be 134 nm, and the bromine content was 26.8%.
The polymeric dispersion was applied over various kinds of fabrics, including cotton and polyester. The treated fabrics were tested according to test CFR16/1615. The results were good, such the treated fabrics may be considered as sufficient flame retarded in accordance with said test.
PBBMA dispersion: The same as in Example 1.
Pre-emulsion: To a 1 liter round bottom flask, fitted with mechanical stirrer, add 90 gr water and 5-9 gr Anionic surfactant. After 5-10 min mixing at 250 rpm, add slowly, one by one and while stirring the following ingredients: 1-3 gr acrylic acid, 25-40 gr N-methylol acryl amide (45% solids), 220-290 gr butyl acrylate and 15 gr water. Stir the thus obtained stable pre emulsion for another 15 min.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, 2 dropping funnels and Nitrogen inlet, add 90 gr water, 0.5-3 gr Anionic surfactant and 0.5 gr Ammonia. Pass hot water through the jacket, to warm the solution up to 80-82° C. Apply Continuous stirring at 200-300 rpm. Introduce nitrogen under the surface of the liquid for 10 min. Add a first initiator solution, made by dissolving 0.5 gr APS in 3 gr water. 5 min later, add 8-25 gr of the pre-emulsion described above. Few minutes later, when no change in Temp is observed, add the rest of the pre emulsion through one dropping funnel and through the second dropping funnel add 472 gr of the PBBMA dispersion of example 1, drop wise, over 4 hour. Add a main initiator solution, prepared by dissolving 1-3 gr APS and 0.5 gr ammonia in 40 gr water simultaneously with the dispersion and the pre emulsion. Keep Temperature at 80-82° C. during the procedure. After 4 hours, raise temperature to 85° C., and mix the obtained dispersion for another 45-55 min. Let the temperature drop to 65° C., and add a solution of 1-3 gr TBHP in 5 gr water. After 5 min stirring, add a solution of 0.3-2 gr Formosul in 5 gr water. Cool the obtained dispersion to room temperature, and add with stirring 2 gr Ammonia and 2 gr Biocide.
Example 8
This is another example for an extraordinary non-viscous dispersion obtainable in accordance with the present invention. This polymeric dispersion was applied to various kinds of fabrics, such as cotton and polyester, and tested according to test CFR16/1615. The results were good, such that the treated fabrics may be considered as sufficient flame retarded.
The aqueous dispersion prepared by the inventor in accordance with the present example had 40.1% solid content and a viscosity as low as 10 cps (Brookfield, LVT, spindle 1, 60 rpm). The polymer particle size was measured to be 137 nm, and the polymer bromine content was 43%.
PBBMA dispersion: The same as in Example 4.
Pre-emulsion: To a 1 liter round bottom flask, fitted with mechanical stirrer, add 90 gr water, 5-8 gr of a 2:1 mixture of Anionic surfactant and with Nonionic high HLB surfactant. After 5-10 min mixing at 250 rpm, add slowly, with constant stirring according to the following order 1-4 gr acrylic acid, 15-30 gr N-methylol acryl amide (45% solids), 110-150 gr butyl acrylate and 15 gr water. Stir the stable pre emulsion thus obtained for another 15 min.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, 2 dropping funnels and Nitrogen inlet, add 177 gr water, and 0.55 gr Ammonia. Pass hot water through the jacket to warm the solution up to 80-82° C. Apply Continuous stirring at 200-300 rpm. Introduce nitrogen under the surface of the liquid for 10 min. Add a first initiator solution, made by dissolving 0.5 gr APS in 3 gr water. 5 min later, add the pre emulsion one of the dropping funnels and 492 gr of PBBMA dispersion of example 4 through the other dropping funnel, drop wise, over 5 hours. Add a main initiator solution, prepared by dissolving 1-3 gr APS and 0.5 gr ammonia in 40 gr water simultaneously with both dispersion and pre emulsion. Keep temperature at 80-82° C. during the procedure. After 5 hours, raise the temperature to 85° C., and stir the dispersion for another 45-55 min. Lower the temperature to 65° C., and add a solution of 1-3 gr TBHP in 5 gr water. After 5 min, add a solution of 0.3-2 gr Formosul in 5 gr water. Cool the obtained dispersion to room temperature, and add with stirring 2 gr Antifoam and 2 gr Biocide.
Example 9
Here a copolymer of PBBMA, butyl acrylate, acrylic acid and N-methylol acryl amide is prepared. The inventor obtained in accordance with this example, am aqueous polymeric dispersion having 49.3% solid content and viscosity of 530 cps (Brookfield, LVT, spindle 2, 30 rpm). The polymer was measured to have a particle size of 176 nm and bromine content of 47.2%. This polymeric aqueous dispersion was applied to various kinds of fabrics, such as cotton, polyester, etc, and tested according to test CFR16/1615. The results were good, such that the treated fabrics may be considered as sufficient flame retarded.
PBBMA dispersion: The same as in Example 4.
Solution: To a 1 liter round bottom flask, fitted with mechanical stirrer, add slowly, with constant mixing, by the given order, 60 gr butyl acrylate, 1-3 gr Acrylic Acid and 0.5-1.5 anionic alkyl aryl solphonic acid based surfactant slowly.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, 2 dropping funnels and Nitrogen inlet, add 134 gr water, 1-4 gr nonionic high HLB surfactant and 0.6 gr Ammonia. Pass hot water through the jacket, to warm the solution up to 80-82° C. Stir continuously at 200-300 rpm. Introduce nitrogen under the surface of the liquid for 10 minutes. Add a first initiator solution, made by dissolving 0.5 gr APS in 3 gr water. 5 min later, add the obtained solution through one dropping funnel, and add simultaneously through the other dropping funnel, drop wise, over 5 hours, a mixture of 660 gr of final PBBMA dispersion, described under example 4, and 25-40 gr N-Methylol Acryl Amide. Add a main initiator solution, prepared by dissolving 1-3 gr APS, 0.5-2 gr nonionic high HLB surfactant and 0.5 gr ammonia in 30 gr water, simultaneously with both the dispersion and the pre emulsion. Keep the temperature at 80-82° C. during the procedure. After 5 hours, raise the temperature to 85° C., and the stir the obtained for another 45-55 min. Lower the temperature to 65° C., and add a solution of 1-3 gr TBHP in 5 gr water. After 5 min, add a solution of 0.3-2 gr Formosul in 5 gr water. Cool the dispersion to room temperature, and add with stirring 0.5 gr Antifoam and 2 gr Biocide.
Example 10
This and the following two examples demonstrate another aspect of the present invention, according to which a solution (rather than dispersion or emulsion) of the brominated polymer is first prepared.
In accordance with this example an aqueous dispersion with 48% solid content, and viscosity of 15 cps (Brookfield, LVT, spindle 1, 60 rpm) was prepared. The polymer included therein was made of PBBMA, acrylic acid and N-methylol acryl amide, had a bromine content of 24.3% and the size of the polymeric particles was 950 nm. The obtained polymer had a calculated Tg of 115° C.
PBBMA solution: To a 1 liter round bottom flask, fitted with mechanical stirrer, add 320-350 gr styrene and warm up to 45-50° C. Add 130-180PBBMA powder (styrene: PBBMA weight ratio 1.8:1) and stir until the obtained solution appears to be clear. Cool the solution to room temperature.
Pre-emulsion: To a 1 liter round bottom flask, fitted with mechanical stirrer, add 204 gr water, 1-4 gr linear anionic surfactant, 3-6 gr non ionic, alcohol Ethoxylated surfactant with HLB value of 15-18, 3-6 gr acrylic acid, 15-30 gr N-methylol acryl amide (45% solids), the above PBBMA solution and 15 gr water. These ingredients should be added slowly, in the given order, with continuous stirring. Stir the stable pre emulsion obtained in this manner for another 15 min.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, dropping funnel and Nitrogen inlet, add 204 gr water, 0.5 gr sodium carbonate and 0.5 gr sodium bicarbonate. Pass hot water through the jacket, to warm the solution up to 80-82° C. Stir continuously at 200-300 rpm. Introduce nitrogen under the surface of the liquid for 10 minutes. Add a first initiator solution, made by dissolving 0.5 gr APS in 5 gr water. 5 min later, add the pre emulsion obtained this way through the dropping funnel, drop wise, over 4 hours. Add a main initiator solution, prepared by dissolving 1-3 gr APS and 1 gr ammonia in 40 gr water simultaneously with adding the pre emulsion. Keep the temperature at 80-82° C. during the procedure. After 4 hours, raise the temperature to 86° C., and stir the obtained dispersion for another 45-55 min. Lower the temperature to 70° C., and add a solution of 1-3 gr TBHP in 4 gr water. After 5 min, add a solution of 0.5-2 gr Formosul in 8 gr water. Cool the obtained dispersion to room temperature, and add 2 gr Ammonia and 2 gr biocide while stirring.
A polymer obtained in accordance with this example was applied to various kinds of fabrics such as cotton and polyester, and tested according to test CFR16/1615. The results were good and the substrates may be considered as sufficient flame retarded.
Example 11
The polymer obtained in the present example is similar in monomer content to that obtained in the preceding example, but includes also butyl acrylate, which makes it more hydrophobic and lowers its Tg value. Please note also the difference in the order according to which the components are added to the pre-emulsion. The aqueous dispersion obtained in accordance with this example had 50.8% solids content and viscosity of 31 cps (Brookfield, LVT, spindle 1, 60 rpm). The polymer had a particle size of 803 mn and bromine content of 20.5%. The calculated Tg of the obtained polymer was 59 C.
PBBMA solution: Prepare according to Example 10.
Pre-emulsion: To a 1 liter round bottom flask, fitted with mechanical stirrer, add slowly, with stirring and by the following order 204 gr water, 1-4 gr linear anionic surfactant, 3-6 gr non ionic, high HLB alcohol Ethoxylated surfactant, 3-6 gr acrylic acid, 15-30 gr N-methylol acryl amide (45% solids), 120-160 gr butyl acrylate, the above PBBMA solution and 15 gr water. Stir the stable pre emulsion obtained this way for another 15 min.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, dropping funnel and Nitrogen inlet, add 180 gr water, 0.6 gr ammonia and 1 gr sodium bicarbonate. Pass hot water through the jacket, to warm the solution up to 80-82° C. Stir Continuously at 200-300 rpm. Introduce nitrogen under the surface of the liquid for 10 minutes. Add a first initiator solution, made by dissolving 0.5 gr APS in 5 gr water. 5 min later, add the pre emulsion through the dropping funnel, drop wise, over 4 hours. Add also a main initiator solution, prepared by dissolving 1.7-2.7 gr APS and 1 gr ammonia in 40 gr water, simultaneously with adding the pre emulsion. Keep the temperature at 80-82° C. during the procedure. After 4 hours. Raise the temperature to 86° C., and stir the dispersion for another 45-55 min. Lower the temperature to 70° C., and add a solution of 1-3 gr TBHP in 4 gr water. After 5 min, add a solution of 0.5-2 gr Formosul in 8 gr water. Cool the dispersion to room temperature, and add with stirring 2 gr Ammonia and 2 gr biocide.
Example 12
This example shows that antimony oxide may be added to the aqueous dispersion during the polymerization process, and it may also be added into the pre-emulsion before polymerization.
A polymer that was prepared in accordance with the present invention had 51.9% solid content, and viscosity of 2250 cps (Brookfield, LVT, spindle 4, 12 rpm). The polymer showed particle size of 138 nm, bromine content of 22.5%, and had a calculated Tg of 116° C.
PBBMA solution: Prepare as detailed in Example 10.
Pre-emulsion: To a 1 liter round bottom flask, fitted with mechanical stirrer, add slowly, one by one, in accordance with the given order, and with constant stirring 204 gr water, 3-6 gr anionic surfactant, 1-4 gr acrylic acid, 20-35 gr N-methylol acryl amide (45% solids), 75-90 gr antimony pentaoxide dispersion(Nyacole A1550PH7) the above PBBMA solution and 15 gr water. Stir the stable pre emulsion thus obtained for another 15 minutes.
Polymerization process: To a 1.7 liter, 5-neck, round bottom flask, with warming/cooling double glassing jacket, fitted with mechanical stirrer, reflux condenser, thermometer, dropping funnel and Nitrogen inlet, add 122 gr water, 75-90 gr antimony pentaoxide dispersion (Nyacole A1550PH7), 0.5-3 gr anionic surfactant and 0.5 gr sodium bicarbonate. Pass hot water through the jacket, to warm the solution up to 80-82° C. Stir continuously at 200-300 rpm. Introduce nitrogen under the surface of the liquid for 10 min. Add a first initiator solution, made by dissolving 0.4 gr APS in 5 gr water. 5 minutes later, add the pre emulsion through the dropping funnel, drop wise, over 4 hours. Add a main initiator solution, prepared by dissolving 1-3 gr APS and 1 gr ammonia in 35 gr water simultaneously with the addition of the pre emulsion. Keep the temperature at 80-82° C. during the procedure. After 4 hours, raise the temperature to 86° C., and stir the dispersion for another 45-55 min. Lower the temperature to 70° C., and add a solution of 1-3 gr TBHP in 4 gr water. After 5 min, add a solution of 0.5-2 gr Formosul in 8 gr water. Cool the obtained dispersion to room temperature, and add 2 gr Ammonia and 2 gr biocide while stirring.
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The present invention provides a polymer, an aqueous suspension of a polymer, methods for obtaining them, and fire-retardant products comprising a polymer and antimony oxide. The polymer of the invention is made of (i) at least one non-brominated monomer and (ii) at least one brominated monomer having the structure A-B-C, wherein A is a phenyl, substituted with 3-5 bromine atoms, B is a C1 to C4 alkyl, optionally substituted with 1 to 8 bromine atoms, and C is an acrylic or methacrylic group. An example of a suitable brominated monomer is penta bromo methyl acrylate. Preferable polymers have at least 20% w/w bromine. Preferable aqueous suspensions have at least 40% solid content. Fire-retardant products according to the invention comprise a polymer made of at least one bromine-containing monomer and at least one non-brominated monomer. Preferable fire-retardant products include polymers according to the invention.
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FIELD OF THE ART
This invention relates to metal structures used in construction, proposing a system of assembling the sections which are arranged as columns and beams in said metal structures, by means of which assemblies are obtained with the rigid consistency of conventional welded assemblies, with an advantageous mounting arrangement by means of screws as in conventional articulated assemblies.
STATE OF THE ART
The use of metal structures as a support frame in building construction is known, using resistant H-shaped sections or similar configurations for forming said structures, such that the assemblies between said sections must be done with the resistance and safety assurances required by the specific mounting in each case.
A system used for the assemblies of the sections of said structures is the rigid assembly system carried out by means of welding, therefore the assemblies are very resistant, but they have the drawback that performing the welds is very expensive, which is even more significant in welds that inevitably have to be carried out in the structure installation site.
Articulated assemblies by means of screwing are used for assemblies requiring less resistance, these assemblies being easy to carry out and mount at the site, so they are used whenever the necessary resistance conditions so allow, nevertheless their limited resistance in many cases does not make them substitutes for the rigid welded assemblies.
OBJECT OF THE INVENTION
According to this invention, a system is proposed which allows carrying out assemblies with the advantages for resistance of rigid welded assemblies and with the advantages of easy mounting of the screwed assemblies, thus overcoming the drawbacks of various conventional solutions, such that it provides very considerable advantages.
This system object of the invention is based on the incorporation of accessories housed between the side flanges and web of the sections that are to receive the assembly of other secondary sections in the structures of application, such that the assembly of these second sections is done by means of screws which pass through the corresponding assembly part of said second sections, together with the part of the receiving sections on which the assembly is carried out and the corresponding part of at least one accessory.
Assembly nodes between the component sections for the structures are thus obtained which have the resistance of rigid welded assemblies due to the extra thickness determined in the anchoring area by the accessories and the resistant distribution of stress that said accessories provide on the entire surface occupied by them. The thickness of the accessories can vary where applicable according to the resistance that is required in the assembly in each application.
Said assemblies carried out with the system of the invention have on the other hand the advantage of the screwed assemblies as regards the mounting because the fastening between the elements of the assembly is carried out by means of screwed anchoring, which can be carried out with relative ease at the installation site once the parts to be assembled have been suitably prepared in the shop, such that the pre-prepared elements are taken to the installation site where only the screwed anchoring must be carried out.
The accessories incorporated in the assemblies according to the proposed system are rigid elements with a basic U-shaped configuration that are can be fitted between the flanges and web of the receiving section of the assembly, such accessories, however, being able to adopt different implementations according to the features of the assemblies to be carried out in each application.
In this sense, the accessories can be, for example, U-shaped with at least one of the side flanges having a greater length than the flanges of the assembly receiver section, so rigid assemblies that are highly resistant in the coinciding parts of the accessories and the receiving section can be carried out, while at the same time being able to carry out assemblies of less resistance by means of anchoring secondary sections directly on the projecting part of the accessories.
When the assemblies require special resistance, the accessories can also be provided with stiffening reinforcements, for example by means of transverse partitions between their flanges perpendicular to the central web, or by means of a prismatic tubular configuration, i.e. with the basic U shape closed by means of a transverse assembly between the ends for the side flanges.
The mentioned system object of the invention is certainly very advantageous, taking on a life of its own and preferably applicable in the function for which it is intended.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an exploded perspective view of the corresponding accessories on the receiving section of an assembly according to the proposed system.
FIG. 2 shows an exploded perspective view of the ensemble of the assembly of two secondary sections on a receiving section according to the mentioned system of the invention.
FIG. 3 shows a perspective view of the assembly of four secondary sections on a receiving section according to the arrangement of the previous figure.
FIG. 4 shows an upper plan view of the assembly of the previous figure.
FIG. 5 shows a perspective view of a practical embodiment including other ways of fastening the secondary sections on the receiving section in an assembly which is also part of the scope of the invention.
FIG. 6 shows another practical embodiment of a group of assemblies with the system of the invention.
FIG. 7 shows an upper plan view of the ensemble of the previous Figure.
FIG. 8 shows a perspective view of a practical embodiment including an assembly with a reinforced accessory between its flanges.
FIG. 9 shows a perspective view of another practical embodiment including an assembly with a tubular-shaped accessory.
FIG. 10 shows an enlarged perspective view of an embodiment of a reinforced accessory such as the one of the attachment of FIG. 8 .
FIG. 11 shows an enlarged perspective view of an embodiment of a tubular accessory such as the one of the attachment of FIG. 9 .
FIG. 12 shows a perspective view of a partial metal structure ensemble carried out with assemblies according to the system of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The object of the invention relates to an assembly system for forming metal building frame structures and the like, for the purpose of carrying out an assembly between the component elements of said structures with the particularities of resistance of rigid welded assemblies but with the ease of mounting of articulated screwed assemblies. This system is useful for the assembly of beam sections on the column sections, and vice versa, in the corresponding structures and it is further applicable with any type of conventional sections used in said structures, such as those of an H-shaped section, an I-shaped section, a U-shaped section, etc.
The system is based on the incorporation of accessories ( 1 ) in the areas of the assemblies so as to arrange the anchoring of the corresponding elements ( 2 and 3 ) to be assembled in each case by means of screws ( 4 ) which are arranged such that they pass through both the respective parts of the elements ( 2 and 3 ) which are assembled and at least one accessory ( 1 ), which gives the anchoring a resistance making it equivalent to conventional rigid welded assemblies.
The accessories ( 1 ) used in the application of the system are U-shaped in their most basic implementation, with width and depth dimensions which correspond with the dimensions between the side flanges and the web of the receiving sections ( 2 ) which receive the assemblies to be carried out, such that to carry out the fastening of said accessories ( 1 ), they are fitted between the flanges and web of the corresponding assembly receiving section ( 2 ) as shown in FIGS. 1 and 2 .
The sections ( 3 ) to be fastened in the assemblies are conventionally equipped with a front plate ( 5 ) fixed on their end to form the coupling on the assembly receiving section ( 2 ), the fastening being carried out by means of screws ( 4 ) which are included through the mentioned plate ( 5 ), at the same time passing through the corresponding receiving section ( 2 ) and the accessory or accessories ( 1 ), as can be seen in FIGS. 2 , 3 and 4 .
Assemblies are thus obtained in which the anchoring is reinforced by the corresponding accessories ( 1 ), which provide extra thickness giving rigidity and distributing the resistant stress throughout the entire area occupied by such accessories ( 1 ), such that the resistance must not be supported by the receiving section ( 2 ) at any point in the areas in which the screws ( 4 ) are applied, so the assemblies are very resistant, being equivalent to the conventional rigid assemblies carried out by means of welding, the walls of the receiving section ( 2 ) also being able to be of a relatively reduced thickness.
The assemblies of the secondary sections ( 3 ) can be done both on the sides and on the front parts of the receiving section ( 2 ), with the only condition that the anchoring plate ( 5 ) for the secondary sections ( 3 ) is of a suitable width in each case because in front assemblies, said plate ( 5 ) must pass between the side flanges of the corresponding receiving section ( 2 ) to be coupled to the area of the web of said section ( 2 ), as can be seen in FIG. 4 .
Assemblies for fastening secondary sections ( 3 . 1 ) directly on the ensemble of the receiving section ( 2 ) and the respective accessory ( 1 ), without a coupling plate ( 5 ), can be formed, as shown in FIG. 5 , without altering the scope and with the same resistant anchoring effect.
In one embodiment, the accessories ( 1 ) can have one or both of its side flanges oversized in length such that in the coupling with respect to the receiving section ( 2 ) of the assemblies, part of said flanges projects from the mentioned accessories ( 1 ) with respect to the side flanges of the section ( 2 ), a lower fastening resistance of secondary sections ( 3 . 2 ) able to be provided directly on said projecting part of the oversized flanges of the accessories, as shown in FIGS. 6 AND 7 .
The resistance of the assemblies varies according to the thickness of the accessories ( 1 ) that are arranged, such that more or less resistant assemblies can be obtained by incorporating accessories ( 1 ) with a different thickness. However, the rigidity and resistance of the accessories ( 1 ) may also vary according to other features, for example by means of including transverse reinforcements ( 6 ) between the side flanges and perpendicular to the web, as shown in FIG. 10 , with which type of accessories ( 1 ) the assemblies can however be carried out in the same way as with the simple U-shaped accessories ( 1 ) as shown in FIG. 8 .
In the same sense, tubular-shaped accessories ( 1 . 1 .), as shown in FIG. 11 , can be used in the assemblies within the scope of the invention, also being able to carry out secondary sections ( 3 ) with them on a receiving section ( 2 ), as shown in FIG. 9 . In the case of said tubular-shaped accessories ( 1 . 1 .), openings ( 7 ) for accessing the interior are provided therein so as to facilitate the handling of the mounting of the anchoring screws ( 4 ).
In any case, any type of assemblies needed in forming the applicable metal structures can be carried out in any case by means of the system of the invention, based on the incorporation of accessories ( 1 or 1 . 1 .) in the anchoring assemblies between secondary sections ( 3 ) and a receiving section ( 2 ), whether coupled on the side or on the front on the receiving sections ( 2 ), or with a perpendicular arrangement or an inclined arrangement of the secondary sections ( 3 ) with respect to the receiving sections ( 2 ), as shown in FIG. 12 .
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The invention relates to a rigid screwed assembly system for metal structures, which is designed to fix secondary sections ( 3 ) to a H-shaped receiving section ( 2 ) or similar. According to the invention, accessories ( 1 ) are provided at the assembly points, said accessories being fitted into the receiving section ( 2 ), and the secondary sections are fixed using screwed attachments ( 4 ) which pass through the corresponding assembly parts of the sections ( 2 and 3 ) as well as the corresponding accessories ( 1 ).
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This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application Ser. No. 60/325,349, filed Sep. 27, 2001.
FIELD OF THE INVENTION
This invention relates generally to a process for improving the shelf life of hindered phenol antioxidants by intimately contacting it with an sulfur-containing peroxide decomposer.
BACKGROUND OF THE INVENTION
Polymers are subject to degradation by environmental forces, such as actinic radiation, oxidation, moisture, atmospheric pollutants and combinations thereof. Degradation, which primarily consists of a change in molecular weight of the polymers, may result in discoloration, brittleness, loss of clarity and mechanical strength, surface crazing and other manifestations.
Antioxidants are often used during the processing of polymers, such as polymer extrusion and molding, to inhibit or retard polymer oxidation and it ensuing degradative effects.
Oxidative degradation of polymers is a sequential process involving initiation, propagation, and termination phases. The initiation phase is started by the formation of free radicals, which may be produced by a number of factors such as the presence of reactive peroxides in the polymerization step, thermal, mechanical and radiation stresses during processing or end-use, or chemical reactions with impurities in the polymer. During the propagation phase, these radicals react with oxygen to form peroxy (ROO.) and alkoxy (RO.) radicals which in turn abstract hydrogen from the polymer to form unstable hydroperoxides (ROOH), alcohols (ROH) and new hydrocarbon free radicals (R.). These free radicals can once again combine with oxygen to continue the oxidative cycle.
Antioxidants can stop this oxidation cycle by interfering with the initiation and propagation steps. Primary antioxidants, such as hindered phenolics and secondary amines, are radical scavengers and react with free, peroxy and alkoxy radicals. Secondary antioxidants, such as phosphites and thioesters, act as peroxide decomposers and react with the unstable peroxides (ROOH) to form more stable alcohols.
One of the problems with some of the hindered phenol primary antioxidants is that they do not have long shelf lives. They tend to yellow with age, which is undesirable because the yellowness imparts color to the polymer. The present invention relates to a process of improving the shelf life of a hindered phenol antioxidant by intimately mixing it with a sulfur-containing peroxide decomposer thereby reducing the yellowness that results from age.
A number of publications, such as U.S. Pat. Nos. 4,820,755; 5,155,153 and 4,579,900, have disclosed the combination of hindered phenol antioxidant and thioesters. However, these patents only disclose the use of these components to stabilize a polymeric composition, and are only mixed together at the time of processing the polymer. There is no disclosure or teaching in these documents on increasing the shelf life of a hindered phenol antioxidant by mixing with a sulfur-containing peroxide decomposer.
SUMMARY OF THE INVENTION
The present invention relates to a process for improving the shelf life of a hindered phenol antioxidant comprising the step of intimately mixing the hindered phenol antioxidant with a sulfur-containing peroxide decomposer. The inventors have discovered that mixing the peroxide decomposer with the hindered phenol antioxidant reduces the tendency of hindered phenols to yellow with age. This increases the desirability of the hindered phenol because it will not impart color to polymer systems.
The present invention also relates to a composition produced from the process described above, and stabilized compositions and additive packages containing the composition produced from the above-described process.
DETAILED DESCRIPTION OF THE INVENTION
The present invention concerns a process for improving the shelf life of a hindered phenol antioxidant comprising the step of intimately mixing the hindered phenol antioxidant with a sulfur-containing peroxide decomposer.
The term “intimately mixing” means that the two components are mixed together so that they are in intimate contact. Examples of such intimate mixing include, but are not limited to at least partially dissolving the two components in a solution, (solution form) or melting one or both components (melt form). The two components are then mixed using any suitable method depending on the form. Although not wishing to be bound by any theory, it appears that there may be a chemical interaction, such as a complex, between the two components, and that they should be in intimate contact in order to improve the shelf life of the hindered phenol antioxidant. In contrast, merely mixing the two components in dry (e.g., powder) form is not intimate mixing because it does not appear to improve shelf life of the hindered phenol antioxidant.
The phrase “improving shelf life” means that the amount of yellowing that occurs in the hindered phenol antioxidant with age is reduced as compared to a hindered phenol antioxidant control that does not contain the sulfide-containing peroxide decomposer. The amount of yellowing that is reduced versus the control preferably is greater than about 5%, or greater than about 10%, or greater than about 20%, or greater than about 30%, or greater than about 50% based on the shelf life testing procedure, (percent transmission (% T) at 420 nm), disclosed in Examples 13 to 24 of the present application. The above percentages can be calculated using the formula—% yellowing reduced=100×((% T sample−% T control)/% T control).
The hindered phenol antioxidants are known compounds used in the polymer industry. Preferably, these compounds contain at least one group of the formula:
wherein R 1 is hydrogen, substituted or unsubstituted alkyl, cycloalkyl, aryl, or araalkyl or substituted thioether having up to 18 carbon atoms and R 2 is a substituted or unsubstituted alkyl, cycloalkyl, aryl, or araalkyl or substituted thioether having up to 18 carbon atoms. The above phenolic compound may also be further substituted with additional substituents. Preferably, R 1 and R 2 are independently methyl or tert-butyl.
Examples of hindered phenol antioxidants include, but are not limited to: 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-i-butylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-(α-methylcyclohexyl)-4,6-dimethylphenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-methoxymethylphenol, 2,6-dinonyl-4-methylphenol, 2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol, 2,2′-thiobis(6-tert-butyl-4-methylphenol), 2,2′-thiobis(4-octylphenol), 4,4′-thiobis(6-tert-butyl-3-methylphenol), 4,4′-thiobis(6-tert-butyl-2-methylphenol), 2,2′-methylenebis(6-tert-butyl-4-methylphenol), 2,2′-methylenebis(4,-ethyl-6-tert-butylphenol), 2,2′-methylenebis(6-tert-butyl-4-ethylphenol), 2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol], 2,2′-methylenebis(4-methyl-6-cyclohexylphenol), 2,2′-methylenebis(6-nonyl-4-methylphenol), 2,2′-methylenebis(4,6-di-tert-butylphenol), 2,2′-ethylidenebis(4,6-di-tert-butylphenol), 2,2′-ethylidenebis(6-tert-butyl-4-isobutylphenol), 2,2′-methylenebis[6-(α-methylbenzyl)-4-nonylphenol], 2,2′-methylenebis[6-(α-α-dimethylbenzyl)-4-nonylphenol], 4,4′-methylenebis(2,6-di-tert-butylphenol), 4,4′-methylenebis(6-tert-butyl-2-methylphenol), 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol, 1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-3-n-do-decylmercaptobutane, ethylene glycol bis[3,3-bis(3′-tert-butyl-4′-hydroxyphenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methylphenyl)dicyclopentadiene, bis[2-(3′-tert-butyl-2′-hydroxy-5′-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide, isooctyl 3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate, bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) dithioterephthalate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, dioctadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate and the calcium salt of monoethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 2-propenoic acid 2-(1,1-dimethylethyl)-6-[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]methyl]-4-methylphenylester, benzene propanoic acid 3,5,-bis(1,1-dimethyl-ethyl)-4-hydroxy-1,6, hexanediylester, benzene propanoic acid 3-(1,-dimethylethyl)-4-hydroxy)-5-methyl-1,2, ethanediylbis(oxy-2,1-ethanediyl)ester, 2,2,-ethylidene-bis-(4,6-ditert-butylphenol, 4,4′,4″-(2,4,6-trimethyl-1,3,5-benzenetriyl)tris-(methylene)tris[2,6,-bis(1,1-dimethylethyl)phenol, 1,3,5-tris(3,5-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)-trione, octadecyl-3-5-di-tert-butyl-4-hydroxyhydrocinnamate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2-6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 2,6-di-tert-butyl-n,d-dimethylamino-p-cresol, 2,2′-oxamido bis-[ethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 4-methyl-2,6-bis(1-phenylethyl)-phenol, triethyleneglycol-bis-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, N,N′-hexamethylene-bis-(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 2,2′-methylene-bis-6-(1-methyl-cyclohexyl)-para-cresol, Benzenepropanoic acid-3,5-bis(1,1-dimethylethyl)-4-hydroxy-C13-15-branched and linear alkyl esters, 2,2′-thiodiethyl bis-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, tocopherol and mixtures thereof.
A preferred list of phenol antioxidants are 1,3,5-tris(4-tert-butyl-3-hydroxy-2-6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, octadecyl-3-5-di-tert-butyl-4-hydroxyhydrocinnamate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 1,1,3-tris(2′-methyl-4′-hydroxy-5′-t-butylphenyl)butane, a compound of the formula:
wherein p is an integer of 1 to about 50, and mixtures thereof.
The sulfur-containing peroxide decomposers are also known compounds used in the polymer area. Preferably, these compounds are thioesters. Many thioesters have the formula:
where R 3 and R 4 are alkyl or alkoxy groups of 1 to about 30 carbon atoms and m and n are integers from 1 to about 10.
Examples of sulfur-containing peroxide decomposers include, but are not limited to: laurylhexylthiodipropionate, dilaurylthiodipropionate, ditridecylthiodipropionate, butylstearylthiodipropionate, 2-ethylhexyllaurylthiodipropionate, di-2-ethylhexylthiodipropionate, diisodecylthiodipropionate, isodecyltetradecylthiodiheptanoate, laurylstearylthiodipropionate, distearylthiodipropionate, hexyltetracosylthiodiacetate, octyltetradecylthiodibutyrate, heptylheptadecylthiodiheptanoate, dimyristyl thiodipropionate, neopentanetetrayl tetrakis(3-dodecylthiopropionate), the 1-lauryl-8-stearyl diester of 4-thiaoctanedioic acid, propanoic acid-3-(dodecylthio)-2,2-bis[3-(dodecylthio)-1-oxopropoxy]methyl-1,3-propanediyl ester, the 1-hexyl-10-tetracosyl diester of 3-thiadecanedioic acid, mercaptobenzimidazole or the zinc salt of 2-mercaptobenzimidazole, zinc alkyldithiocarbamates, zinc dibutyldithiocarbamate, dioctadecyl monosulfide, dioctadecyl disulfide, pentaerythritol tetrakis(β-dodecylmercapto)propionate tetramethyl-thiuram monosulfide, N-cyclohexyl-2-benzothiazolesulfenamide, 2-(morpholinothio)benzothiazole, N-tert-butyl-2-benzothiazolesulfenamide, 2-mercaptobenzothiazole, tetramethylthiuram disulfide, 4,4′dithiodimorpholine and mixtures thereof.
The amount of the sulfur-containing peroxide decomposer is about 0.01% to about 50% by weight based on the total weight of the hindered phenol antioxidant and the sulfur-containing peroxide decomposer. Preferably, the amount of the sulfur-containing peroxide decomposer is about 0.1% to about 30%, about 0.3% to about 20%, about 0.5% to about 15% or about 1% to about 10% by weight based on the total weight of the hindered phenol antioxidant and the sulfur-containing peroxide decomposer.
Preferably, the sulfur-containing peroxide decomposer is intimately mixed with the hindered phenol antioxidant during or just subsequent to the hindered phenol's manufacture. “Just subsequent” means less than about 10 days, or less than about 5 days from the manufacture of the hindered phenol.
The sooner the sulfur-containing peroxide decomposer is mixed with the hindered phenol antioxidant, the better the shelf life. Preferably, the intimate mixing is conducted during the manufacturing process when the hindered phenol may already be in solution form and before it is crystallized and/or dried in solid form.
The dissolution of the two component system in solution form may be conducted in any suitable solvent provided that at least one, and preferably both of the components are at least partially dissolved, and preferably totally dissolved in the solvent. One skilled in the art will be able to choose a suitable solvent.
Similarly, if the two components are mixed in melt form, at least one, and preferably both of the components are at least partially melted, and preferably totally melted when mixed together. One skilled in the art would be able to choose a suitable method such as mixing them in an extruder.
The present invention also contemplates an antioxidant composition produced by the process disclosed above.
This invention further contemplates a stabilized composition containing the two component antioxidant system and a material to be stabilized. Examples of such materials are: polyolefins, polyesters, polyethers, polyketones, polyamides, natural and synthetic rubbers, polyurethanes, polystyrenes, high-impact polystyrenes, polyacrylates, polymethacrylates, polyacetals, polyacrylonitriles, polybutadienes, polystyrenes, ABS, styrene acrylonitrile, acrylate styrene acrylonitrile, cellulosic acetate butyrate, cellulosic polymers, polyimides, polyamideimides, polyetherimides, polyphenylsulfides, polyphenylene oxide, polysulfones, polyethersulfones, polyvinylchlorides, polycarbonates, polyketones, aliphatic polyketones, thermoplastic TPO's, aminoresin crosslinked polyacrylates and polyesters, polyisocyanate crosslinked polyesters and polyacrylates, phenol/formaldehyde, urea/formaldehyde and melamine/formaldehyde resins, drying and non-drying alkyd resins, alkyd resins, polyester resins, acrylate resins cross-linked with melamine resins, urea resins, isocyanates, isocyanurates, carbamates, epoxy resins, cross-linked epoxy resins derived from aliphatic, cycloaliphatic, heterocyclic and aromatic glycidyl compounds, which are cross-linked with anhydrides or amines, polysiloxanes, Michael addition polymers, amines, blocked amines with activated unsaturated and methylene compounds, ketimines with activated unsaturated and methylene compounds, polyketimines in combination with unsaturated acrylic polyacetoacetate resins, polyketimines in combination with unsaturated acrylic resins, radiation curable compositions, epoxymelamine resins, organic dyes, cosmetic products, cellulose-based paper formulations, photographic film paper, ink, waxes, fibers and mixtures thereof.
The stabilized composition may also contain other additives conventionally employed in the UV stabilizing art such as other anti-oxidants, UV absorbers and stabilizers, metal deactivators, hydroxylamines, nitrones, co-stabilizers, nucleating agents, clarifying agents, neutralizers metallic stearates, metal oxides, hydrotalcites, fillers and reinforcing agents, plasticizers, lubricants, emulsifiers, pigments, rheological additives, catalysts, level agents, optical brighteners, flameproofing agents, anti-static agents and blowing agents. Examples of these additives may be found, for example, in U.S. Pat. No. 6,096,886, herein incorporated by reference in its entirety. Further examples are those described in Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition, Vol. A18, pp. 429-471, VCH, Weinheim 1991; and Calbo, Leonard J., ed., Handbook of Coatings Additives, New York: Marcel Dekker (1987).
This invention also contemplates an additive package comprising the composition produced by the process above and the other additives conventionally employed in the UV stabilizing art listed above.
Especially preferred additives for the additive package and the stabilized composition are UV stabilizers and other antioxidants including, but not limited to 2-(2′-hydroxyphenyl)benzotriazoles, oxamides, 2-(2-hydroxphenyl)-1,3,5-triazines, 2-hydroxybenzophenones, sterically hindered amines and hindered phenol antioxidants.
Examples of such anti-oxidants and UV stabilizers are: 2-(2′-hydroxy-5′-methylphenyl)-benzotriazole; 2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)benzotriazole; 2-(5′-tert-butyl-2′-hydroxyphenyl)benzotriazole; 2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole; 2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole; 2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5-chloro-benzotriazole; 2-(3′-sec-butyl-5′-tert-butyl-2′-hydroxyphenyl)-benzotriazole; 2-(2′-hydroxy-4′-octoxyphenyl)benzotriazole; 2-(3′,5′-di-tert-amyl-2′-hydroxphenyl)benzotriazole; 2-(3′,5′-bis(α,α-dimethylbenzyl)-2′-hydroxyphenyl)-benzotriazole; a mixture of 2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)-carbonylethyl]-2′-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)benzotriazole, 2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)benzotriazole, 2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)benzotriazole and 2-(3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenylbenzotriazole; 2,2-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-ylphenol], the transesterification product of 2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxyphenyl]benzotriazole with polyethylene glycol 300; [R—CH 2 CH—COO(CH 2 ) 3 ] 2 B where R=3′-tert-butyl-4′-hydroxy-5′-2H-benzotrazol-2-ylphenyl; bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate; bis(2,2,6,6-tetramethylpiperidin-4-yl)succinate; bis(1,2,2,6,6-pentamethylpiperidin-4-yl)sebacate; bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl)sebacate; bis(1,2,2,6,6-pentamethylpiperidin-4-yl) n-butyl 3,5-di-tert-butyl-4-hydroxybenzylmalonate; the condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid; the condensate of N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine; tris(2,2,6,6-tetramethylpiperidin-4-yl)nitrilotriacetate; tetrakis(2,2,6,6-tetramethylpiperidin-4-yl)-1,2,3,4-butanetetracarboxylate; 1,1′-(1,2-ethanediyl)bis(3,3,5,5-tetramethylpiperazinone); 4-benzoyl-2,2,6,6-tetramethylpiperidine; 4-stearyloxy-2,2,6,6-tetramethylpiperidine; bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate; 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decan-2,4-dione; bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate; bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate; the condensate of N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine; the condensate of 2-chloro-4,6-bis(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine and 1,2-bis(3-aminopropylamino)ethane; the condensate of 2-chloro-4,6-bis(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine and 1,2-bis-(3-aminopropylamino)ethane; 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione; 3-dodecyl-l-(2,2,6,6-tetramethylpiperidin-4-yl)pyrrolidin-2,5-dione; 3-dodecyl-1-(1-ethanoyl-2,2,6,6-tetramethylpiperidin-4-yl)pyrrolidin-2,5-dione; 3-dodecyl-1-(1,2,2,6,6-pentamethylpiperidin-4-yl)pyrrolidine-2,5-dione; a mixture of 4-hexadecyloxy- and 4-stearyloxy-2,2,6,6-tetramethylpiperidine; the condensate of N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro-1,3,5-triazine; the condensate of 1,2-bis(3-aminopropylamino)ethane, 2,4,6-trichloro-1,3,5-triazine and 4-butylamino-2,2,6,6-tetramethylpiperidine; 2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxospiro[4.5]decane; oxo-piperanzinyl-triazines and the reaction product of 7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro[4.5]decane and epichlorohydrin; 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine; 2-(2-hydroxy-4-n-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; 2-(2-hydroxy-4-(mixed iso-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; 2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine; 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazin 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; 2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; 2-[2-hydroxy-4-(2-hydroxy-3-butyloxypropyloxy)phenyl]4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; 2-[2-hydroxy-4-(2-hydroxy-3-octyloxypropyloxy)-phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; 2-[4-dodecyloxy/tridecyloxy-2-hydroxypropoxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; 2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxypropoxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; 2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl-1,3,5-triazine; 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine; 2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxypropoxy)phenyl]-1,3,5-triazine; 2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,5-triazine, 2,4-dihydroxybenzophenone; 2-hydroxy-4-methoxybenzophenone; 2-hydroxy-4-octyloxybenzophenone; 2-hydroxy-4-decyloxybenzophenone; 2-hydroxy-4-dodecyloxybenzophenone; 2-hydroxy-4-benzyloxybenzophenone, 4,2′,4-trishydroxybenzophenone; 2′-hydroxy-4,4′-dimethoxybenzophenone; 1,3,5-tris(2,6-dimethyl-4-tert-butyl-3hydroxybenzyl)isocyanurate; 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate; 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene; 2,6-di-tert-butyl-4-methylphenol; 2,2′-ethylidene-bis(4,6-di-tert-butylphenol); 1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane; esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols; esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyhydric alcohols; dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphosphonate; diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate; dioctadecyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate; dioctadecyl-5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate; and the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid; amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid such as N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine; N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamine; and N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine.
The present invention will now be illustrated by the following examples. The examples are not intended to limit the scope of the present invention. In conjunction with the general and detailed descriptions above, the examples provide further understanding of the present invention.
EXAMPLES
Examples 1 to 12 Preparation of Antioxidant Compositions
Several compositions were prepared using 1,3,5-tris(4-tert-butyl-3-hydroxy-2-6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione (CYANOX® 1790, a trademark of Cytec Industries Inc.) as the hindered phenol antioxidant. A sample of the hindered phenol antioxidant was sampled near the end of its manufacturing process. To approximately a 30% solution of the hindered phenol antioxidant (150 gm) in a methyl isobutyl ketone (MIBK) solvent was added a series of peroxide decomposers as disclosed in Table 1 below. The percent peroxide decomposer added in the Examples is based on the weight of the hinder phenol antioxidant. The mixtures were vacuum distilled and then crystallized using standard methods.
TABLE 1
% Peroxide
Example #
Peroxide decomposer
decomposer
1
None
0
2
Distearylthiodipropionate
0.3
(CYANOX ® STDP)
3
STDP
0.67
4
STDP
1
5
STDP
1.3
6
STDP
1.6
7
STDP
3.3
8
STDP
6.6
9
5-butyl-5-ethyl-2-[2,4,6-tris(1,1-dimethylethyl)-
1.67
phenoxy]-1,3,2-dioxaphosphorinane
(ULTRANOX ® 641)
10
bis(2,4-di-t-butyl)pentaerythritol diphosphite
1.67
(ULTRANOX ® 626)
11
3,9-bis[2,4-bis(1-methyl-1-
1.67
phenylethyl)phenoxy]-2,4,8,10-tetraoxa-3,9-
diphosphaspiro[5.5]undecane
(DOVERPHOS ® S-9228)
12
tris-(2,4-di-t-butyl phenyl) phosphite
1.67
(IRGAFOS ® 168)
ULTRANOX is a trademark of G. E. Specialty Chemicals Inc.
CYANOX is a trademark of Cytec Industries Inc.
DOVERPHOS is a trademark of Dover Chemical Corporation
IRGAFOS 168 is a trademark of Ciba Specialty Chemicals, Corp.
Examples 13 to 24 Shelf Life Testing
The above samples were tested for shelf life. The shelf life tests were performed by placing the samples in a glass container with five holes drilled into the cap for air circulation. The glass containers were then placed in a convection oven at 50° C. for fifty days to accelerate the aging process. The aged samples were then dissolved in toluene for a 23% solution (30 gm sample in 100 gm toluene). The percent transmission, (%T), of the solution was measured at a wavelength of 420 nm as an indication of yellowness. The higher the percent transmission, the less yellowing and the greater the improvement in shelf life.
TABLE 2
Preparation
Percent transmission
Example #
Example
% peroxide decomposer
(% T)
13
1-Control
0
51.5
14
2-Sulfur
0.3
53
15
3-Sulfur
0.67
64
16
4-Sulfur
1
75
17
5-Sulfur
1.3
81
18
6-Sulfur
1.6
80
19
7-Sulfur
3.3
82
20
8-Sulfur
6.6
91.5
21
9-Phosphite
1.67
35
22
10-Phosphite
1.67
17
23
11-Phosphite
1.67
53
24
12-Phosphite
1.67
46
The results demonstrate that the sulfur-containing peroxide decomposer decreased the amount of yellowing thereby improving the shelf life of the hindered phenol antioxidant. Surprisingly, the compositions containing the phosphite-based peroxide decomposers were similar, or had more yellowing than the control.
Comparison Example C-25—Shelf Life Testing Without Intimate Mixing
A comparison sample, C-25, was prepared to determine if physically mixing powders of the hindered phenol antioxidant and sulfur-containing peroxide decomposer would lead to a reduction of yellowing with age. The components, STDP and CYANOX 1790, were physically dry blended. The blend was then shelf life tested using the procedure in Examples 13 to 24 above. The result is shown in Table 3 below.
TABLE 3
Example
% peroxide decomposer
Percent transmission (% T)
C-25
5.25
48.5
This data shows that physical dry blending of the components does not result in an improvement in shelf life.
The invention described and claimed herein is not to be limited in scope by the specific embodiments herein disclosed, since these embodiments are intended as illustrations of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.
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The present invention relates to a process for improving the shelf life of a hindered phenol antioxidant comprising the step of intimately mixing the hindered phenol antioxidant with a sulfur-containing peroxide decomposer. The inventors have discovered that mixing the peroxide decomposer with the hindered phenol antioxidant reduces the tendency of hindered phenols to yellow with age. This increases the desirability of the hindered phenol because it will not impart color to polymer systems. The present invention also relates to a composition produced from the process described above, and stabilized compositions and additive packages containing the composition produced from the above-described process.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of Korean Application No. 2002-46778, filed Aug. 8, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a washing machine, and more particularly, to a disinfecting washing machine equipped with a disinfecting liquid dispenser.
2. Description of the Related Art
Colloidal silver can be produced by forming silver ions (Ag + ) and dissolving them in water. The colloidal silver is used as an antibacterial agent or a bactericide. It is reported that the colloidal silver eliminates about 650 different kinds of bacteria. In particular, the colloidal silver is characterized as not inducing resistance, which is different from general antibiotics, and is safe because the colloidal silver has no toxic effects. Methods of manufacturing the colloidal silver are an electrolysis method, a chemical resolution method and a pulverization method.
A disinfecting washing machine is a washing machine that is equipped with a disinfecting liquid dispenser that produces and supplies a colloidal silver to disinfect laundry through antibacterial and bactericidal actions of the colloidal silver.
A conventional disinfecting washing machine is described below with reference to FIGS. 1 and 2 .
FIG. 1 is a cross section of a conventional disinfecting washing machine. As shown in FIG. 1 , a water tub 104 is disposed in a body casing 102 to contain washing water. A washing tub 106 is disposed in the water tub 104 . A pulsator 108 is mounted in a lower portion of an interior of the washing tub 106 to be rotated in forward and reverse directions so as to form currents of the washing water. A drive unit 110 is positioned under the water tub 104 to rotate the washing tub 106 and the pulsator 108 . The drive unit 110 comprises a drive motor 112 and a power transmission unit 114 . The drive motor 112 is rotated by power supplied thereto, and the power transmission device 114 serves to selectively transmit power generated by the drive motor to the pulsator 108 and the washing tub 106 . A belt 116 is wound around the drive motor 112 and the power transmission device 114 to mediate transmission of the power. A drain assembly 118 comprises a pipe 118 a to drain the washing water from the washing tub 106 and a drain pipe valve 118 b , which selectively opens and closes the drain pipe 118 a to allow draining of the washing water from the washing tub 106 .
FIG. 2 is a partially sectional view of a conventional disinfecting liquid dispenser. As depicted in FIG. 2 , when power is supplied to the washing machine and a washing course is selected while laundry is contained in a disinfecting washing machine, washing water is fed into an interior of a water tub 104 . The washing water fed into the water tub 104 dissolves a detergent while passing through a detergent dispenser (not shown), and is supplied to the water tub 104 along with the dissolved detergent.
If a user selects a disinfection washing course, an inlet valve 204 of a disinfecting liquid dispenser 120 , connected to external source of water through an inlet pipe 212 , is opened and the water is supplied to an interior of a storage container 122 , whereas the washing water is fed to the water tub 104 . When power is applied to two silver plates 220 and 222 of the disinfecting liquid dispenser 120 , a silver disinfecting liquid is produced. The silver disinfecting liquid is supplied to the interior of the washing tub 106 and disinfects the laundry.
The water supplied though an inlet 202 of the storage container 122 is halted to stabilize a speed and a current of the water while filling a first space 210 of the storage container 122 . The water contained in the first space 210 overflows a first partition 206 and flows into a second space 214 . The water having passed through the first space 210 and flowing into the second space 214 fills the second space 214 to a water level corresponding to the height of a second partition 208 . After the second space 214 is filled with the water, the water overflows the second partition 208 and flows into a third space 224 and then is supplied to the interior of the washing tub 106 through an outlet pipe 124 from an outlet 216 of the storage container 122 . The water flows into the third space 224 while a certain amount of the water is contained in the second space 214 . In a process, the silver disinfecting liquid is produced through electrolysis in the water, and the produced disinfecting liquid is supplied to the washing tub 106 through the outlet 216 . The process of producing a disinfecting liquid is continuously carried out while the water is supplied to the storage container 122 . A top 218 of the storage container 122 fixedly holds the sliver plates 220 and 222 in the water contained in the second space 214 . The storage container 122 , the top 218 , the inlet 202 , the outlet 216 and the bypass pipe 128 may be of a nonconductive material.
Further, in the process of producing the disinfecting liquid, if the amount of the water supplied through the inlet 202 is large, the water contained in the interior of the storage container 122 flows into a drain pipe 118 a through a bypass pipe 128 from a bypass outlet 126 at an upper portion of the storage container 122 , so the water can be maintained at an appropriate water level in the storage container 122 , thereby enabling a disinfecting liquid of a certain concentration to be produced. When the process of producing a disinfecting liquid is stopped, the water supply to the storage container 122 is stopped by closing of the inlet value 204 and the power to the silver plates 220 and 222 is stopped. At that time, the water remaining in the interior of the storage container 122 flows into the outlet 216 through remaining water discharging holes 206 a and 208 a and is completely discharged from the storage container 122 .
After the washing water including the disinfecting liquid fills the washing tub 106 , washing of the laundry is performed by a rotation of the pulsator 108 and bacteria are killed by the disinfecting liquid in a process of the washing of the laundry.
The disinfecting liquid dispenser 120 carries out the electrolysis in the water by alternately applying a positive voltage and a negative voltage to the two silver plates 220 and 222 , respectively, thus generating the silver ions. The amount of the silver ions, which is a concentration of the colloidal silver, is proportional to an amount of current flowing through the two silver plates 220 and 222 or an amount of voltage applied to the two silver plates 220 and 222 .
The disinfecting performance obtained by the colloidal silver is determined by the concentration of the colloidal silver. If the concentration of the colloidal silver is excessively low, a disinfecting performance of the colloidal silver decreases; but if the concentration of the colloidal silver is excessively high, the colloidal silver discolors the laundry. Accordingly, the concentration of the colloidal silver has to be appropriately adjusted so as not to damage the laundry while disinfecting the laundry. To produce the appropriate concentration of the colloidal silver, the amount of voltage applied to the two silver plates 220 and 222 or the amount of current flowing through the two silver plates 220 and 222 has to be appropriately adjusted.
Since the concentration of the colloidal silver is varied according to a pressure and temperature of the water, the voltage applied to the two silver plates 220 and 222 or the current flowing through the two silver plates 220 and 222 must not be limited to a fixed value but must be varied in a certain range so as to maintain the concentration of colloidal silver in an appropriate range.
SUMMARY OF THE INVENTION
Accordingly, an aspect of the present invention is to provide a disinfecting washing machine, which is capable of controlling an amount of voltage applied to silver plates using a pulse width modulation signal, so a colloidal silver can have a concentration in an appropriate range that sufficiently disinfects laundry but does not damage the laundry.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
To accomplish the above and/or other aspects, a disinfecting washing machine comprises a disinfecting liquid dispenser supplying a disinfecting liquid to disinfect laundry; a drive unit outputting first and second voltages to determine a concentration of the disinfecting liquid; and a control unit detecting the concentration of the disinfecting liquid and controlling the drive unit so that the concentration of the disinfecting liquid is within a preset range.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a cross section of a conventional disinfecting washing machine;
FIG. 2 is a partially sectional view showing a disinfecting liquid dispenser of FIG. 1 ;
FIG. 3 is a block diagram showing a device for controlling a concentration of colloidal silver used in a washing machine of an embodiment of the present invention;
FIG. 4 is a circuit diagram of a drive unit of the colloidal silver concentration control device of the embodiment of the present invention; and
FIGS. 5A-5E are charts showing waveforms of signals applied to the drive unit of FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
A disinfecting washing machine and method of controlling the disinfecting washing machine are described with reference to FIGS. 3 , 4 and 5 A- 5 E. FIG. 3 is a block diagram showing a device for controlling the concentration of colloidal silver used in a washing machine of an embodiment of the present invention. As shown in FIG. 3 , a drive unit 302 alternately applies positive and negative voltages to a disinfecting liquid dispenser 304 to produce colloidal silver. Levels and polarities of the voltages applied to the disinfecting liquid dispenser 304 from the drive unit 302 are controlled by a duty ratio of a pulse width modulation signal 314 , a first switching signal 316 and a second switching signal 318 outputted from a control unit 306 to the drive unit 302 .
An amount of current supplied to the disinfecting liquid dispenser 304 is proportional to amounts of voltages applied to the disinfecting liquid dispenser 304 . The amount of current, supplied to the disinfecting liquid dispenser 304 , is detected by a current detection unit 308 and a current/voltage conversion unit 310 . The control unit 306 determines the duty ratio of the pulse width modulation signal 314 in consideration of the amount of the current being currently supplied to the disinfecting liquid dispenser 304 . If the amount of current being currently supplied to the disinfecting liquid dispenser 304 deviates from an appropriate range that can produce the colloidal silver of an appropriate concentration necessary for a disinfection of laundry, the amount of current supplied to the disinfecting liquid dispenser 304 is controlled to be in the appropriate range by increasing or decreasing a pulse width of the pulse width modulation signal 314 .
If excessive amounts of voltages are supplied to the disinfecting liquid dispenser 304 , a concentration of the colloidal silver is increased, thus damaging the laundry. A current limiter 312 generates an excessive current signal 320 and inputs the excessive current signal 320 to the control unit 306 when the amount of current detected by the current detection unit 308 exceeds a preset reference value. When the excessive current signal 320 is generated, the control unit 306 decreases the concentration of the colloidal silver by lowering a level of voltage applied to the disinfecting liquid dispenser 304 by decreasing the duty ratio of the pulse width modulation signal 314 to the drive unit 302 , or by completely shutting off a power supply to the disinfecting liquid dispenser 304 .
A construction of the drive unit 304 controlling the concentration of the colloidal silver is described in detail below with reference to FIGS. 4 and 5 A- 5 E. FIG. 4 is a circuit diagram showing the drive unit of the colloidal silver concentration control unit. As shown in FIG. 4 , a PNP bipolar transistor 402 and an NPN bipolar transistor 404 form a first series circuit between a voltage VCC and a second voltage GND. A PNP bipolar transistor 406 and a NPN bipolar transistor 408 form a second series circuit in parallel with the first series circuit.
First and second NPN bipolar transistors 410 and 412 are connected in series to each other between a base of the PNP bipolar transistor 402 of the first series circuit and the second voltage GND. The first NPN bipolar transistor 410 is controlled by the pulse width modulation signal 314 , while the second NPN bipolar transistor 412 is controlled by the first switching signal 316 . Accordingly, when the pulse width modulation signal 314 and the first switching signal 316 are both at a high level, the first and second NPN bipolar transistors 410 and 412 are both turned on. When the first and second NPN bipolar transistors 410 and 412 are both turned on, the PNP bipolar transistor 402 of the first series circuit is turned on. As a result, while the second NPN bipolar transistor 412 is turned on, the duty ratio of the pulse width modulation signal 314 determines a turned-on range of the PNP bipolar transistor 402 of the first series circuit. The NPN bipolar transistor 404 of the first series circuit is controlled by the second switching signal 318 . A first control voltage 326 outputted from between the PNP bipolar transistor 402 and the NPN bipolar transistor 404 of the first series circuit is applied to one of the two silver plates 220 or 222 of the disinfecting liquid dispenser 304 .
Third and fourth NPN bipolar transistors 414 and 416 are connected in series to each other between a base of the PNP bipolar transistor 406 of the second series circuit and the second voltage GND. The third NPN bipolar transistor 414 is controlled by the pulse width modulation signal 314 , while the fourth NPN bipolar transistor 416 is controlled by the second switching signal 318 . Accordingly, when the pulse width modulation signal 314 and the second switching signal 318 are both at a high voltage level, the third and fourth NPN bipolar transistors 414 and 416 are both turned on. When the third and fourth NPN bipolar transistors 414 and 416 are both turned on, the PNP bipolar transistor 406 of the second series circuit is turned on. As a result, while the fourth NPN bipolar transistor 416 is turned on, the duty ratio of the pulse width modulation signal 314 determines a turned-on range of the PNP bipolar transistor 406 of the second series circuit. The NPN bipolar transistor 408 of the second series circuit is controlled by the first switching signal 316 . A second control voltage 328 outputted from between the PNP bipolar transistor 406 and the NPN bipolar transistor 408 of the second series circuit is applied to a remaining one of the two silver plates 220 or 222 of the disinfecting liquid dispenser 304 . In FIG. 4 , an emitter current of the NPN bipolar transistors 404 and 416 is detected by the current detection unit 308 , as shown in FIG. 3 , and converted into a voltage signal in the current/voltage conversion unit 310 . The control unit 306 determines an amount of current being currently supplied to the disinfecting liquid dispenser 304 based on a magnitude of the converted voltage signal.
FIGS. 5A-5E are charts showing waveforms of signals applied to the drive unit of FIG. 4 .
As shown in FIGS. 5A-5B , the first and second switching signals 316 and 318 , which are input signals, have opposite phases, respectively. A slight dead time t d exists between transition points of the first and second switching signals 316 and 318 . If the first and second switching signals 316 and 318 transition at a same time, an overlapped range is formed. In this case, the two silver plates 220 and 222 of the disinfecting liquid dispenser 304 are short-circuited. When the dead time t d is provided between the first and second signals 316 and 318 , the two silver plates 220 and 222 of the disinfecting liquid dispenser 304 can be prevented from short-circuiting. As shown in FIG. 5C , the pulse width modulation signal 314 , which is another input signal, is a signal whose duty ratio is variable by the control unit 306 . The duty ratio of the pulse width modulation signal 314 , as shown in FIG. 5C , is 100%.
As shown in FIGS. 5D-5E , the first and second control voltages 326 and 328 , which are output signals, have opposite phases. A phase of the first control voltage 326 is a same phase as that of the first switching signal 316 , while a phase of the second control voltage 328 is a same phase as that of the second switching signal 318 . Levels of the first and second control voltages 326 and 328 are proportional to the duty ratio of the pulse width modulation signal 318 . In FIG. 5D-5E , the levels “A” of the first and second control voltages 326 and 328 are for the case where the duty ratio of the pulse width modulation signal 314 is 100%, the levels “B” of the first and second control voltages 326 and 328 are for the case where the duty ratio of the pulse width modulation signal 314 is about 90%, and the levels “C” of the first and second control voltages 326 and 328 are for the case where the duty ratio of the pulse width modulation signal 314 is about 50%.
An operation of the drive unit 302 , which controls the colloidal silver concentration, of the disinfecting liquid dispenser 304 is described with reference to FIGS. 4 and 5 A- 5 E. If the first switching signal 316 of the input signals 314 , 316 and 318 , as shown in FIGS. 5A-5C , respectively, is at a high voltage level and the second switching signal 318 is at a low voltage level, the first switching signal 316 is a high voltage level, so the second NPN bipolar transistor 412 is turned on. In this state, since the first NPN bipolar transistor 410 is only turned on when the pulse width modulation signal 314 is in a high voltage level range, the PNP bipolar transistor 402 of the first series circuit has a turned-on range which is equal to the high voltage level range of the pulse width modulation signal 314 . At this time, the second switching signal 318 is at the low voltage level, so the NPN bipolar transistor 404 of the first series circuit is turned off.
In contrast, the fourth NPN bipolar transistor 416 is turned off by the second switching signal 318 of the low voltage level. Accordingly, turned-on and turned-off operations of the third NPN bipolar transistor 414 in response to the pulse width modulation signal 314 do not affect operation of the PNP bipolar transistor 406 of the second series circuit. At this time, the first switching signal 316 is at the high voltage level, so the NPN bipolar transistor 408 of the second series circuit is turned on.
As described above, in a range where the first switching signal 316 is at the high voltage level and the second switching signal 318 is at the low voltage level, only the PNP bipolar transistor 402 of the first series circuit and the NPN bipolar transistor 408 of the second series circuit are turned on, so that a source voltage VCC, the PNP bipolar transistor 402 of the first series circuit, the disinfecting liquid dispenser 304 , the NPN bipolar transistor 408 of the second series circuit and the second voltage GND provide a closed circuit to enable current to flow through the two silver plates 220 and 222 . In this case, the first control voltage 326 has a positive polarity, while the second control voltage 328 has a negative polarity. Since a turned-on range of the PNP bipolar transistor 402 of the first series circuit is proportional to the duty ratio of the pulse width modulation signal 314 , the levels of the first and second control voltages 326 and 328 are proportional to the duty ratio of the pulse width modulation signal 314 .
If the first switching signal 316 is at the low voltage level and the second switching signal 318 is at the high voltage level as a result of alternating the voltage levels of the first and second switching signals 316 and 318 , the second switching signal is at the high voltage level, so the fourth NPN bipolar transistor 416 is turned on. In this state, the third NPN bipolar transistor 414 is only turned on when the pulse width modulation signal 314 is in the high voltage level range, so that the PNP bipolar transistor 406 of the second series circuit has a turned-on range which is equal to the high voltage level range of the pulse width modulation signal 314 . At this time, the first switching signal 316 is at the low voltage level, so that the NPN bipolar transistor 408 of the second series circuit is turned off.
In contrast, the second NPN bipolar transistor 412 is turned off by the first switching signal 316 of the low voltage level. Accordingly, turned-on and turned-off operations of the first NPN bipolar transistor 410 in response to the pulse width modulation signal 314 do not affect operation of the PNP bipolar transistor 402 of the first series circuit. At this time, the second switching signal 316 is at the high voltage level, so that the NPN bipolar transistor 404 of the first series circuit is turned on.
As described above, in a range where the second switching signal 318 is at the high voltage level and the first switching signal 316 is at the low voltage level, only the PNP bipolar transistor 406 of the second series circuit and the NPN bipolar transistor 404 of the first series circuit are turned on, so the source voltage VCC, the PNP bipolar transistor 406 of the second series circuit, the disinfecting liquid dispenser 304 , the NPN bipolar transistor 404 of the first series circuit and the second voltage GND provide a closed circuit and enable current to flow through the two silver plates 220 and 222 . In this case, the first control voltage 326 has the negative polarity, while the second control voltage 328 has the positive polarity. Since the turned-on range of the PNP bipolar transistor 406 of the second series circuit is proportional to the duty ratio of the pulse width modulation signal 314 , the levels of the first and second control voltages 326 and 328 are proportional to the duty ratio of the pulse width modulation signal 314 .
As described above, the polarities of the first and second control voltages 326 and 328 outputted from the drive unit 302 to the disinfecting liquid dispenser 304 are repeatedly alternated by the first and second switching signals 316 and 318 . The amounts of the first and second control voltages 326 and 328 are controlled to be proportional to the duty ratio of the pulse width modulation signal 314 . Since the first and second control voltages 316 and 318 are voltages applied to the two silver plates 220 and 222 , the colloidal silver of a concentration proportional to the levels of the first and second control voltages 326 and 328 is produced. The control unit 306 determines whether the concentration of a currently produced colloidal silver is within an appropriate range by monitoring an amount of current flowing through the two silver plates 220 and 222 . If the concentration of the colloidal silver deviates from the appropriate range, the control unit 306 adjusts the amounts of the first and second control voltages 326 and 328 applied to the disinfecting liquid dispenser 304 by varying the duty ratio of the pulse width modulation signal 314 . Since the polarities of the first and second control voltages 326 and 328 are repeatedly alternated, an oxidation and a reduction of silver ions are uniformly carried out on the two silver plates 220 and 222 , thus preventing only one of the two silver plates 220 and 222 from being consumed.
As described above, a disinfecting washing machine is provided, which is capable of maintaining a concentration of a colloidal silver within an appropriate range, which does not damage laundry while sufficiently disinfecting the laundry, by controlling amounts of voltages applied to silver plates based on a preset concentration of the colloidal silver using a duty ratio of a pulse width modulation signal. Further, the disinfecting washing machine prevents only one of the two silver plates from being consumed by repeatedly alternating polarities of first and second control voltages 326 and 328 .
Although a few preferred embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
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A disinfecting washing machine includes a disinfecting liquid dispenser, a drive unit and a control unit. The disinfecting liquid dispenser supplies a disinfecting liquid to disinfect laundry. The drive unit outputs first and second voltages to determine a concentration of the disinfecting liquid. The control unit detects the concentration of the disinfecting liquid and controlling the drive unit so that the disinfecting liquid has a concentration within a preset range.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The invention relates to an apparatus and method for the repair of failure areas in a previously set plug within a subterranean well.
(2) Brief Description of the Prior Art
Subterranean wells, such as oil, gas or water wells, are required to be “plugged” when they are abandoned, to assure that any slow flow of hydrocarbons or other fluids within the well do not escape and flow to the top surface of the well. As used herein the term “first plug” is intended to include such conventional plugs as hydraulically set, or mechanically set, or electrically set plugs, bridge plugs, packers and the like, as well as the use of cementious material, alone, or in combination with such other first plugs, as herein described, as typically used to plug off a well or zone in a well to be temporarily or permanently abandoned. These first plugs are many times intended to properly secure the well and prevent any flow of any fluids from within the well to the top of the well or into other formations within the well. Over time, and after exposure to high temperatures and pressures in the well, as well as a corrosive and acidic environment in the well, failures in such plugs occur, as the result of leaks, metallic pitting, loss of elastomeric seal integrity, and the like. It therefore becomes necessary to either mill out the first plug and provide a replacement plugging means of some sort or set additional cement plugs. These procedures are, of course, expensive and time consuming.
U.S. Pat. No. 6,474,414, entitled “Plug For Tubulars” is directed to the use of moltenl solder for providing a plug in a subterranean well which may be poured or otherwise applied directly upon a platform for the molten solder in the well.
U.S. Pat. No. 6,536,349, entitled “Explosive System For Casing Damage Repair” illustrates the use of liquid explosives to fragment damaged casing which has become an obstruction to proper flow of the well.
The present invention addresses problems, as above described.
SUMMARY OF THE INVENTION
The present invention provides a secondary plugging tool for use in a subterranean well for the repair of a first plug previously introduced into and set within the well. The plugging tool comprises an outer tubular housing including a ported lower end. The ports in the ported end may be initially closed by means of a thinner outer portion of the housing which also melts to open the ports during the ignition of the tool, or by a series of meltable eutectic plugs. Alternatively, small, open ports may be provided circumferentially around and immediate the lower end of the outer tubular housing. An inner tubular housing is concentrically positioned within the outer tubular housing. A low temperature melting eutectic metal alloy charge is deposited within the outer tubular housing. A thermitic reaction charge is deposited within the inner tubular housing immediate and covering the ported end. The thermitic reaction charge is also provided in a chamber in a lower housing member selectively and releasably secured to the outer tubular housing. The thermitic reaction charge in the chamber in the lower housing is provided to bake/melt the eutectic metal alloy charge after it is decanted from the upper chamber. Means are secured to at least one of the said housings for introducing, positioning and retrieving the plugging tool.
The igniting charge may be ignited by percussion means, such a dropping of a bar, or by electric signal or other known means.
In lieu of using a separate inner housing for purposes of receiving the thermitic reaction charge, the thermitic reaction charge and the eutectic metal alloy charge may be placed into one housing and separated simply by use of cardboard or plastic tubes or sheets, or the like. In such an arrangement, the thermitic reaction charge would be placed into an interior section, and exteriorally surrounded by the low temperature melting eutectic charge. Ports or port means are provided around the lower end of the housing for permitting flow of the molten eutectic charge upon melting of the eutectic.
The secondary plugging tool of the present invention may be introduced into the well and withdrawn there from on wire line, cable, electric line, or tubing. If it is desired that the secondary plugging tool not be retrieved from the well subsequent to use, it may be left in the well by providing a release mechanism, such as a shear release between the top of inner and outer housings and the line, cable, or tubing used to introduce the tool within the well. Alternatively, the now empty inner and outer tubular members may be separated from the lower housing by providing a releasing means, such as a shear pin connection, between the lowermost end of at least one of the outer tubular housing and the top of the lower housing. When the method is completed, the line, cable, or tubing is pulled until the shear pin mechanism shears and separates the inner and outer housings from the lower housing, and the line or cable or tubing may be retrieved from the well with the lower housing left in the well
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical longitudinal sectional schematic view of the secondary plugging tool of the present invention carried into a well on an electric line and positioned just above a first plug previously placed in the well.
FIG. 2 is a view similar to that of FIG. 1 , illustrating the secondary plugging tool after it has been activated with the eutectic alloy charge flowing out of the openings through the lower end of the outer housing and upon the first plug.
FIG. 3 is an illustration of an alternative design of the present invention wherein the thermitic reaction charge and the eutectic charge are carried within a housing having concentric housing sections.
FIG. 4 is a further illustration of yet another alternative preferred embodiment wherein the eutectic metal alloy charge is secured, such as by casting, or the like, to the exterior of a tubular housing containing the thermitic reaction charge.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now referring to FIG. 1 , there is shown a subterranean well W. The well W includes previously run and set first plug FP. The plug FP contains a number of abrasions, crevices, corrosive spots and electrometric failures, all generally identified as F. These failures F are believed to be the cause of well fluid leaks, previously detected at the top of the well W.
As shown in FIGS. 1 and 2 , the apparatus 100 of the present invention is preferably run into the well W (having casing C) on wire line 101 , of conventional and known nature. Alternatively, it may be run into the well W on tubing or electric line. If means other than electric line are used to run and set the apparatus 100 , an electric line 103 is provided form the top of the well W and connected to a source of electric energy at the top or other location in the well W and is connected at the lower end to a starter charge 104 within an upper section 105 within an inner tubular housing 106 , concentrically positioned within an outer tubular housing member 107 . The housing members 106 and 107 preferably are made of metal, such as an alloy steel or the like.
The lower end of the outer housing member 107 is ported, at ports 108 . Such ports may be provided by making the wall of the outer housing member 107 very thin in a series of circular or other geometric form, spaced radially around the outer housing member lower end, or even the bottom of the outer housing member 107 . If formed in this fashion, the extremely high heat resulting from the ignition of the thermitic reaction charge in the tool 100 will permit these thinned wall portions to give way and open, permitting the eutectic metal alloy charge, described below, in the outer housing to melt and pour through such openings. Alternatively, eutectic plugs may be sealingly placed into openings in the outer housing member 107 , such that melting of the eutectic plugs will transpose the plugged openings into the ports.
The inner housing 106 contains a thermitic reaction charge 109 , as hereinafter described. The housing 106 is in communication with the lower ends of each of the inner and outer tubular housings 106 and 107 as well as a lower housing 110 having a chamber 111 , also containing the thermitic reaction charge. A release joint 120 , or a shear pin connection 120 , of known construction and commercially available from a number of sources, secures the tubular housings 106 and 107 to the lower housing 110 . Alternatively, a meltable or shear release mechanism may be provided between the lower housing 110 and the outer housing 107 .
The invention contemplates use of two charges of materials. The first, or lower temperature melting eutectic metallic alloy LTA is deposited into the interior of the outer housing 107 . The eutectic composition LTA is an alloy, which, like pure metals, has a single melting point. This melting point is usually lower than that of any of the constituent metals. Thus, for example, pure Tin melts at 449.4 degrees F., and pure Indium melts at 313.5 degrees F., but combined in a proportion of 48% Tin and 52% Indium, they form a eutectic which melts at 243 degrees F. Generally speaking, the eutectic alloy composition LTA of the present invention will be a composition of various ranges of Bismuth, Lead, Tin, Cadmium and Indium. Occasionally, if a higher melting point is desired, only Bismuth and Tin or Lead need be used. The chief component of this composition LTA is Bismuth, which is a heavy coarse crystalline metal that expands when it solidifies. Water and Antimony also expand but Bismuth expands much more than the former, namely 3.3% of its volume. When Bismuth is alloyed with other materials, such a Lead, Tin, Cadmium and Indium, this expansion is modified according to the relative percentages of Bismuth and other components present. As a general rule, Bismuth alloys of approximately 50 percent Bismuth exhibit little change of volume during solidification. Alloys containing more than this tend to expand during solidification and those containing less tend to shrink during solidification. After solidification, alloys containing both Bismuth and Lead in optimum proportions grow in the solid state many hours afterwards. Bismuth alloys that do not contain Lead expand during solidification, with negligible shrinkage while cooling to room temperature. In summary, when reference herein is made to a low temperature alloy composition, or “a low temperature melting eutectic melting metal alloy”, we mean to refer to these exemplary compositions and to metallic compositions which melt at temperatures of no more than about 1,100 degrees F.
Most molten metals when solidified in molds or annular areas shrink and pull away from the molds or annular areas or other containers. However, eutectic fusible alloys expand and push against their container when they solidify and are thus excellent materials for use as plugging agents for correcting failure spots in well tubular conduits, such as casing.
The thermitic reaction charge TRC is deposited within a third chamber 130 in the inner housing 106 and within a second chamber 131 in the lower housing 110 . A first chamber 132 houses the LTA in outer housing 107 . The thermitic reaction materials used to prepare the charge will melt at temperatures of about 2,400 degrees F. or greater. An example of thermite, forming the thermitic reaction charge, is a mixture of powdered or granular aluminum or magnesium metal and powdered iron oxide or other oxides. The reaction is very exothermic. 1.
OPERATION
The apparatus 100 of the present invention is run into the well W on wire line 101 or other means well known to those skilled in the art to a depth just above the top of the first plug FP. The tool or apparatus 100 contains the thermitic reaction charge within the inner housing 106 , as well as in the lower housing 110 . The low temperature eutectic metal alloy charge LTA has been placed into the outer housing 107 . The tool 100 is activated by electric activation through electric signal in electric line 103 to activate the fuel charge 109 . The tool 100 may also be activated by a number of other known means such as by percussion means, the dropping of a heavy bar, or the like. Upon activating, the thermitic reaction charge will ignite and the temperature in the chamber outer housing 107 will increase quickly. Upon the outer housing 107 being heated to a temperature in excess of about 1,100 degrees F. i.e. the melting point for the low temperature eutectic metal alloy charge LTA is reached and the eutectic metal alloy charge begins to quickly form a molten mass. The low temperature eutectic charge LTA is permitted to flow through the ports 108 , into the well W and pass upon, through and across the exterior of the first plug FP. Upon cooling and solidification of the LTA within the well W, the tool 100 may be retrieved from the well, or left permanently in the well W and the electric line or tubing or the like disengaged from the tool 100 and removed from the well W.
Although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that this is by illustration only that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention.
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A secondary plugging tool is disclosed for use in a subterranean plug, such as in a plugged and/or abandoned well. The repaired plug may be of a cementicious material, or a mechanically, hydraulically or electrically set plug or packer. The plugging tool includes an outer housing containing an eutectic metal alloy. A thermitic reaction charge is contained within chambers within an inner tubular member and a lower housing. The lower end of the outer housing being ported circumferentially there around, the thermitic reaction charge activates the eutectic metal charge such that the eutectic charge melts and pours out of the outer housing and across and upon the initial plug to repair any failure areas therein.
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RELATED APPLICATIONS
[0001] This patent application claims the benefit of priority from co-pending U.S. Provisional Patent Application Serial No. 60/364,880 filed on Mar. 13, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to curtain walls used for building exteriors and, more particularly, but not by way of limitation, to the construction and assembly of sill and mullion sections of such curtain walls along with the curtain wall panels associated therewith.
[0004] 2. Description of the Related Art
[0005] Curtain walls are typically constructed of extruded aluminum frame support members having generally U-shaped channels (although other shapes may apply) for supporting a plurality of panel members that serve as the exterior of a building. Such panel members are most often panes of glass, and often double pane glass sections, but other paneled building materials such as aluminum, granite, slate, or concrete are also utilized. Such panel members are often of identical size and shape. However, near doors, opening windows, or other access points into the building, panel members of different sizes and shapes may be utilized.
[0006] More specifically, such curtain walls generally include a horizontal sill member having at least one portion forming a channel at the bottom of a wall section, a horizontal head member having a downwardly facing channel at the top of a wall section, and a plurality of vertical mullions running between the sill and head members. Panel members are supported by the channels of the sill member and the head member, and the vertical joints between adjacent panel members are formed at the mullions. In some designs, the mullions are disposed interiorly of the sill member, the head member, and the panel members so that only the joint between adjacent panel members, and not the mullions themselves, are visible from the exterior of the building. The designs do, however, vary, depending upon the desired aesthetics of the curtain wall construction.
[0007] In another curtain wall construction, multiple panel members are typically arranged side-by-side and are secured and sealed between a sill member and a head member, with their vertical joints overlapping at a mullion. This vertical joint must then be sealed from both the interior and exterior of the building using both resilient gaskets, sealant tapes, sealant, and/or structural silicone, as described for reference purposes below.
[0008] An existing solution is set forth and shown in U.S. Pat. No. 6,158,182 and assigned to the assignee of the present invention. Referring now to FIG. 1, a schematic, cross-sectional view of a sill member 10 of an exemplary curtain wall is shown. The sill member 10 secures a curtain wall to a structural support surface such as a concrete slab 12 . The concrete slab 12 may be at ground level or comprising a floor surface of a high rise building. Although not shown in FIG. 1, a head member similar to the sill member 10 secures the curtain wall to a concrete slab between floors of a building or other building structures, and a plurality of mullions span between the sill member 10 and the head member. The sill member 10 is typically formed as an integral aluminum extrusion. The sill member 10 also generally includes a channel section 14 , an anchoring section 16 disposed interiorly of a channel section 14 , and a cover 18 .
[0009] Still referring to FIG. 1, the channel section 14 and the cover 18 cooperate to secure the panel member 20 to the sill member 10 . More specifically, the channel section 14 includes a base 14 a and two legs 14 b and 14 c that form a upwardly facing U-shaped channel. A support member 22 rests on the top surface of the base 14 a . The exterior leg 14 b has a groove 24 proximate the upper end of its interior surface facing the panel member 20 , and the interior leg 14 c has a support surface 26 proximate the upper end of its interior surface. The cover 18 has a downward projecting leg 28 that engages a groove 30 on the exterior surface of the interior leg 14 c . The cover 18 also has two tongues 32 , 49 , one proximate to each end of the cover 18 . The panel member 20 is placed within the channel section 14 on an upper surface of a setting block 34 . An exterior and interior gasket 36 , 38 are located at the upper end of the exterior and interior legs 14 b , 14 c . The gaskets 36 , 38 operate to hold the panel member 20 in the channel section 14 . The setting block 34 is disposed on the top surface of the support member 22 . The exterior gasket 36 has a tongue 36 a that engages the groove 24 of the exterior leg 14 b . The exterior gasket 36 is typically pre-installed in groove 24 of the exterior leg 14 b during the manufacture of the sill member 10 . The interior gasket 38 has a groove 38 a that engages the tongue 32 of the cover 18 and the support surface 26 of the interior leg 14 c . The channel section 14 further includes a plurality of support legs 40 below base 14 a.
[0010] The anchoring section 16 includes a base 16 a , an interior leg 16 b , and a plurality of support legs 42 below the base 16 a . The base 16 a has a plurality of holes 44 spaced along its length for receiving fasteners 46 to secure the sill member 10 to the structural support surface 12 . The interior leg 16 b has a groove 48 for receiving the tongue 49 of the cover 18 . The cover 18 stabilizes the interior gasket 38 that presses against the panel member 20 and also conceals the base 16 a of the anchoring section 16 so that the fasteners 46 are not visible. A drawback of this example is that the panel member 20 cannot be installed until the cover 18 is placed over the fasteners, due to the fact that the cover 18 is needed to hold the interior gasket in place against the panel member 20 . Therefore, the entire structure must be inspected before the panel member 20 is installed as discussed in more detail below.
[0011] The following technique is typically used to install the panel member 20 of such a curtain wall. First, the sill member 10 is laid on a shim 56 in the proper position on the concrete slab 12 and is used as a template to drill holes into the concrete slab 12 for each fastener 46 . One should note that the shim 56 does not run continuously along the length of the sill member 10 . Instead, the shim 56 is used at low points of the concrete slab 12 to level the sill member 10 , if necessary. The sill member 10 is removed from the shim 56 , and a hole 50 with a larger diameter is drilled in the place of each of the holes drilled using the sill member 10 . A structural insert 52 is secured within each of the holes 50 via epoxy or other conventional means. Each insert 52 has an internally threaded hole 54 for receiving fasteners 46 . The sill member 10 is repositioned on the shim 56 and secured to the concrete slab 12 using fasteners 46 . A sealant 58 is disposed continuously on the concrete slab 12 along both the exterior and interior sides of the shim 56 . A head member similar to the sill member 10 is secured to part of the building structure using the above-described techniques. Vertical mullions are secured between the sill member 10 and the head member at appropriate intervals along the curtain wall. The vertical mullions are attached at each side to sill members 10 . The support member 22 is disposed on the base 14 a of the sill member 10 , and the setting block 34 is disposed on the support member 20 . The panel member 20 is then installed from the exterior of the building, typically first being tilted into the channel section of the head member, and then being dropped into the channel section 14 of the sill member 10 . The cover 18 is installed in the sill member 10 , and a glazing stop is installed in the head member of the curtain wall. The interior gasket 38 is disposed on the tongue 32 of the cover 18 of the sill member 10 , and a similar gasket is disposed on the tongue of the glazing stop of the head member.
[0012] While such curtain walls, and other conventional curtain walls, have proved to be reliable commercial building systems, they suffer from several drawbacks. For example, installing the panel members at the building site also requires inspections during the process. These inspections must be performed by building code enforcement personnel, whose schedule may or may not be compatible with time schedules for the contractor erecting such curtain walls.
[0013] Another solution is set forth and shown in U.S. patent application Ser. No. 10/099,070, assigned to the assignee of the present invention, and incorporated herein by reference. Referring now to FIG. 2, a side cross-sectional view a sill assembly 100 of the '070 patent application is shown. By first installing a sill flashing 112 directly upon a support surface 155 such as a concrete slab, the remaining portions of the curtain wall may be assembled at the factory prior to delivery to the field for installation. An outside cap 108 , an interior cover 110 , and a sill member 106 are adapted for resting upon and mounting to the sill flashing 112 .
[0014] The curtain wall as set forth in the '070 patent application is assembled by first temporarily fastening, with a fastener 153 , the sill flashing 112 to the support surface 155 of a building at the job site. The sill member 106 is mounted to two vertical mullions (not shown) at opposite ends of the sill member 106 . An outside cap 108 is secured to the sill member 106 and provides a groove for attaching an exterior gasket 151 . The exterior gasket 151 presses against the exterior of the panel member 150 to secure the panel member 150 set on the top surface of a setting block 200 placed in a channel of the sill member 106 . The sill member 106 , outside cap 108 , panel member 150 , and setting block 200 may be preassembled at a factory prior to being shipped to the job site. However, the sill flashing 112 must be temporarily secured at the job site prior to fastening the sill member 106 and other components permanently to the support surface 155 . After the sill flashing 112 has been temporarily secured to the support surface 150 and the sill member 106 , outside cap 108 , panel member 150 , exterior gasket 151 , and setting block 200 have been assembled at the factory and shipped to the job site, then the sill member 106 is permanently secured to the sill flashing 112 and the support surface 155 with at least one fastener 152 . Building code enforcement personnel then inspect the securement of the sill assembly 100 . Once approved, then the interior cover 110 is secured to the sill flashing 112 and the sill member 106 .
[0015] The '070 patent application allows for some pre-assembly to occur at the factory, however, the sill assembly must to be split into two pieces, namely the sill member 106 and the sill flashing 112 , in order to allow the pre-assembly of the sill member 106 with other components.
[0016] For this reason, it would be greatly advantageous to provide a curtain wall system construction that maximizes the ability for pre-assembly without sacrificing the structural integrity of the overall curtain wall system.
SUMMARY OF THE INVENTION
[0017] The present invention relates to curtain walls used for building exteriors and the assembly of a building curtain wall with a sill and mullion assembly permitting the substantially flush mounted panel members therewith. More particularly, one aspect of the present invention relates to a curtain wall system including a first vertical mullion operable to attach to a first sill member and a second vertical mullion operable to interlock with the first vertical mullion. The present invention also relates to a mullion cap for attaching to a bottom surface of a vertical mullion. The mullion cap includes a substantially planar bottom plate having an upper surface, a lower surface, a front edge, and a back edge. The mullion cap further includes an attachment face located on the upper surface of the substantially planar bottom plate. The attachment face is operable to attach to the vertical mullion.
[0018] In another aspect, the present invention includes a curtain wall system comprising a first vertical mullion operable to attach to a first sill member, and a second vertical mullion operable to interlock with the first vertical mullion. The first vertical mullion may also include a protrusion and the second vertical mullion may include a groove for interlocking with the protrusion. In one aspect, the first sill member attaches to the first vertical mullion via at least one screw spline and screw. The second vertical mullion may also be further operable to attach to a second sill member, while the first sill member may be formed as a single extrusion. The curtain wall system may also include a mullion cap for attaching to a bottom surface of at least one of the first and second vertical mullions. In one aspect, the mullion cap attaches to the first vertical mullion. The vertical mullions may also include a securement clip for attaching the vertical mullions to one another. The securement clip may be fastened to an interior surface of a second vertical mullion. The securement clip includes an extension that abuts a securement face located on an interior surface of the first vertical mullion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] For a more complete understanding of the present invention, and for further objects and advantages thereof, reference is made to the following description taken in conjunction with the accompanying drawings in which:
[0020] [0020]FIG. 1 (Prior Art) illustrates a side cross-sectional schematic view of a sill member of a conventional curtain wall;
[0021] [0021]FIG. 2 illustrates a side cross-sectional view of a sill assembly of a curtain wall system;
[0022] [0022]FIG. 3 illustrates a perspective view of a sill and mullion assembly according to an embodiment of the present invention;
[0023] [0023]FIG. 4 illustrates an enlarged perspective view of a mullion cap as shown in accordance with an alternate embodiment of the present invention;
[0024] [0024]FIG. 5 illustrates an enlarged top view of the vertical mullion and mullion cap as shown in FIG. 4,
[0025] [0025]FIG. 6 illustrates a bottom view of the mullion cap as shown in FIG. 4;
[0026] [0026]FIG. 7 illustrates a bottom exploded view of a sill and mullion assembly including the mullion cap of FIG. 4 according to an alternate embodiment of the present invention;
[0027] [0027]FIG. 8 illustrates a bottom perspective view of the sill and mullion assembly including the mullion cap of FIG. 5;
[0028] [0028]FIG. 9A illustrates a top view of a securement clip of the mullion assembly of an alternate embodiment of the present invention;
[0029] [0029]FIG. 9B illustrates a perspective view of a securement clip of the mullion assembly of FIG. 9A,
[0030] [0030]FIG. 10A illustrates a top view of the engaged securement clip of the mullion assembly of FIG. 9A;
[0031] [0031]FIG. 10B illustrates a perspective view of the engaged securement clip of the mullion assembly of FIG. 10A;
[0032] [0032]FIG. 11 illustrates a perspective view of the sill and mullion assembly according to an alternate embodiment of the present invention; and
[0033] [0033]FIG. 12 illustrates a side cross-sectional view of the sill and mullion assembly including the mullion cap of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] In the present embodiment, as shown in FIG. 3, a curtain wall assembly 250 of a preferred embodiment of the present invention is illustrated. Vertical mullions 300 , 302 are extruded in a shape permitting direct interengagement one with the other. One of the vertical mullions 300 is formed to provide a groove 304 on its rearward face for receiving a protrusion 306 of another of the vertical mullions 302 . The groove 304 and protrusion 306 are arranged so that the vertical mullions 300 , 302 are angled with respect to each other and then rotated until the rearward faces of both vertical mullions 300 , 302 are aligned in a planar fashion as described in more detail in FIGS. 7 and 8. Although the preferred embodiment of the present invention describes the interlocking mechanism of the vertical mullions as a groove 304 and protrusion 306 , any means of interlocking the two vertical mullions 300 , 302 together may be used. For example, a male and female snap arrangement may be employed, as well as two protrusions from the rearward faces of the vertical mullions 300 , 302 which may be secured together with additional fasteners. The interlocking vertical mullions 300 , 302 permit a restricted amount of movement to allow for thermal expansion and contraction while preventing failure under extreme stresses that may be exhibited by a hurricane or other natural disasters.
[0035] Sill members 308 are constructed as a single extrusion for direct engagement with the vertical mullions 300 , 302 via screw splines 310 . The sill members 308 are further constructed to provide a channel 312 for receiving a panel member (not shown) such as glass, granite, or other building material. The sill members 308 are fastened to the vertical mullions 300 , 302 which are then interlocked. The sill members 308 also provide various other grooves within the channel 312 for receiving components used to stabilize or secure the panel member. In the preferred embodiment, the interior surface of a forward leg 312 a of the channel 312 includes two grooves 314 , 316 while the interior surface of an intermediate leg 312 b includes a groove 318 , a support leg 320 , and an upper protrusion 322 . These grooves 314 , 316 , 318 , the support leg 320 , and the upper protrusion 322 may be oriented in a variety of ways to aid in the securement of various components placed in the channel 312 . In an alternate embodiment, the grooves 314 , 316 , 318 , support leg 320 , and upper protrusion 322 are eliminated and the components may be placed directly on the upper surface of a base 312 c of the channel 312 . The face opposite the groove 318 and support leg 320 of the intermediate leg 312 b includes a groove 324 in addition to a groove 326 disposed on the interior surface of a rearward leg 328 . In the preferred embodiment, the screw splines 310 are oriented between the intermediate and rearward legs 312 b and 328 .
[0036] Referring now to FIGS. 4 - 6 , a mullion cap 400 may be used with the curtain wall assembly 250 of the present invention. The mullion cap 400 may also be eliminated in an embodiment of the present invention. The mullion cap 400 includes a bottom plate 402 that is substantially planar and substantially rectangular in shape, however, other orientations may be used depending on the configuration of the vertical mullions 300 , 302 and the sill members 308 . On an upper surface of the bottom plate 402 , an attachment face 404 is located approximately near the center of the bottom plate 402 . In the preferred embodiment, sides of the attachment face 404 do not extend to the outside edges of the bottom plate 402 . In alternate embodiments, the attachment face 404 may be located at a position other that near the center of the bottom plate 402 and may also have sides that extend to or beyond the edges of the bottom plate 402 . Also in the preferred embodiment, the attachment face 404 includes an aperture 406 for securement to at least one of the vertical mullions 300 , 302 . A lower surface of the bottom plate 402 is substantially planar as illustrated in FIG. 6, although other orientations are possible.
[0037] As shown in the top view of FIG. 5, a fastener 500 is utilized to secure the attachment face 404 of the mullion cap 400 to a vertical face 502 of the vertical mullion 302 . The attachment face 404 may also be oriented in another direction to facilitate securement to another face of the vertical mullion 302 . As shown, the bottom plate 402 abuts the lower surface of the vertical mullion 302 and extends on both sides of the vertical face 502 . The bottom plate 402 may also be fabricated to be flush with the vertical face 502 instead of extending past the vertical face 502 .
[0038] [0038]FIGS. 7 and 8 illustrate the process of interlocking the vertical mullions 300 , 302 together, as well as the securement of the mullion cap 400 to the bottom surface of the vertical mullions 300 , 302 . The vertical mullions 300 , 302 are angled with respect to each other and sealant 700 is placed on bottom edges of the vertical mullions 300 , 302 , as well as an upper surface of the mullion cap 400 . The mullion cap 400 is secured to the bottom surface of the vertical mullions 300 , 302 . An end dam 702 may also be utilized in the preferred embodiment and attached to the vertical mullion 300 that is not secured to the mullion cap 400 . The end dam 702 is secured to a vertical face of the vertical mullion 300 in a similar fashion to that of the mullion cap 400 . The sealant 700 placed on the upper surface of the mullion cap 400 marries the end dam 702 to the mullion cap 400 , thereby providing a water tight seal. As shown in FIG. 8, the groove 304 may be placed over the protrusion 306 and rotated into position. In an alternate embodiment, the vertical mullions 300 , 302 may be rotated into position and then the sealant 700 may be applied. Then the mullion cap 400 may be secured to the bottom surface of the vertical mullions 300 , 302 .
[0039] Now referring to FIGS. 9A and 9B, a securement clip 900 according to an alternate embodiment of the present invention is described. To further enhance the structural integrity of the interlocking vertical mullions 300 , 302 during negative pressure loading, a securement clip 900 may be added to an internal face of the vertical mullion 300 including the groove 304 . In a first embodiment of the securement clip 900 , the securement clip 900 is formed of a single aluminum extrusion and is fashioned with an extension 904 at one end of the securement clip 900 . Although in the preferred embodiment a single aluminum extrusion is utilized, other configurations and material may be used to form the securement clip 900 . Other configurations may include multiple pieces and may span only a portion of the interior face. The securement clip may also be integrally formed with the vertical mullion 300 . The securement clip 900 abuts the internal face of the vertical mullion 300 from a side 906 of the groove 304 to a leg 908 oriented at or near a corner 910 of the vertical mullion 300 . The leg 908 abuts at least a portion of the extension 904 . The extension 904 includes a curved end portion for fastening against a securement face 902 of the opposite vertical mullion 302 with the protrusion 306 . The securement face 902 protrudes from an interior surface at or near a corner 912 of the vertical mullion 302 . The extension 904 of the securement clip 900 is operable to contact the securement face 902 as shown in FIGS. 10A and 10B.
[0040] As illustrated in FIGS. 10A and 10B, the curved end portion of the extension 904 abuts the securement face 902 to further secure the vertical mullions 300 , 302 . When the vertical mullions 300 , 302 are interlocked, the respective corners 910 , 912 are oriented near each other to facilitate engagement between the extension 904 and the securement face 902 . As shown, the leg 908 is oriented to protrude rearward of the corners 910 , 912 of the vertical mullions 300 , 302 and supports the extension 904 of the securement clip 900 . When the securement clip 900 is engaged, the leg 908 may rest on the interior surface of the vertical mullion 302 near the securement face 902 .
[0041] [0041]FIG. 11 illustrates the curtain wall assembly 250 once the vertical mullions 300 , 302 have been rotated into place and the mullion cap 400 has been secured to the vertical face 502 of the vertical mullion 302 and a bottom surface of the end dam 702 . Once rotated into position, the rear faces of both vertical mullions 300 , 302 are substantially planar. Depending on the interlocking mechanism utilized, one of the rear faces may be slightly inset with respect to the other rear face. As shown and discussed with reference to FIG. 5, in the preferred embodiment, the bottom plate 402 of the mullion cap 400 substantially covers the lower surface of the curtain wall assembly 250 from the edge of the sill member 308 attached to one vertical mullion 302 to the edge of a second sill member 308 attached to the other vertical mullion 300 that is interlocked with the first vertical mullion 302 . The mullion cap 400 , as installed, creates a water tight seal for the vertical mullions 300 , 302 . The interlocking vertical mullions 300 , 302 also provide addition structural support and do not pull apart when loaded with extreme stresses such as those experienced during natural disasters.
[0042] Referring now to FIG. 12, a curtain wall assembly 250 including a panel member 1000 secured in the channel 312 of the sill member 308 is illustrated. A setting chair 1002 may be fashioned with two legs 1004 , 1006 operable to sit in the grooves 316 , 318 of the forward leg 312 a and the intermediate leg 312 b , respectively. A setting block 1008 rests on an upper surface of the setting chair 1002 . The panel member 1000 has a lower surface that rests on the upper surface of the setting block 1008 . As noted above, the setting block 1008 may also rest on an upper surface of the base 312 c of the channel 312 . An exterior gasket 1010 attaches to the forward leg 312 a via the groove 314 . The exterior gasket 1010 aids in the stabilization and securement of the panel member 1000 in the channel 312 . On the interior side of the panel member 1000 , a plug 1012 is supported by the support leg 320 of the intermediate leg 312 b . On the upper face of the plug 1012 , structural silicone 1014 is utilized to create a water tight and structural seal between the panel member 1000 and the intermediate leg 312 b . In an alternate embodiment, in place of the plug 1012 and the structural silicone 1014 , a gasket similar to the exterior gasket 1010 may be utilized. The panel member 1000 is stabilized and secured via the exterior gasket 1010 , the setting chair 1002 , the setting block 1008 , the plug 1012 , and the structural silicone 1014 . The assembly of the panel member 1000 within the channel 312 may take place at the factory or other alternate site.
[0043] The curtain wall assembly 250 may be assembled at the factory and then shipped to the job site. The assembly required at the job site is the attachment of the sill member 308 to a support structure 1016 of the building via at least one fastener 1018 . The fastener 1018 secures the bottom surface of the sill member 308 to the support structure 1016 . Once the sill member 308 is secured, an assembly cover 1020 is placed over the exposed portion of the sill member 308 . Preferably, the assembly cover 1020 includes two legs 1022 , 1024 , one disposed at each end of the assembly cover 1020 . The forward leg 1022 is operable to fit in the groove 324 located on the intermediate leg 312 b and the rearward leg 1024 is operable to fit in the groove 326 located on the rearward leg 328 . The assembly cover 1020 may also be fastened to the sill member 308 by other securement means such as fasteners or snaps. By allowing direct access to the fully assembled and secured curtain wall assembly 250 , an inspector may easily view the securement of the sill member 308 to the support structure 1016 . Once viewed, the assembly cover 1020 may be secured to the sill member.
[0044] It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description. While the curtain wall assembly shown and described have been characterized as being preferred it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the invention.
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Disclosed is a curtain wall assembly used for building exteriors. The curtain wall system includes a first vertical mullion operable to attach to a first sill member and a second vertical mullion operable to interlock with the first vertical mullion. A mullion cap may be attached to a bottom surface of at least one of the vertical mullions. The mullion cap includes a substantially planar bottom plate having an upper surface, a lower surface, a front edge, and a back edge. The mullion cap further includes an attachment face located on the upper surface of the substantially planar bottom plate. The attachment face is operable to attach to the vertical mullion.
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BACKGROUND OF THE INVENTION
[0001] The present invention is directed to a support device for a cannula. More specifically, the present invention is directed to a cannula support that includes a plurality of interlocking fibers spiral-bound together in a manner that permits selective attachment to a flexible plastic cannula tube for providing cushioned and molded support in and around the ear, and preventing irritation known to be induced by plastic-to-skin contact from the flexible tube.
[0002] A cannula is a somewhat slender and elongated tube that can be used to deliver or remove fluids from the body. In this respect, the more specific nasal cannula or oral-nasal cannula is a device used to deliver supplemental oxygen to a patient in need of respiratory help. At one end, the flexible tube may extend from or attach to a device that might include an oxygen tank, a portable oxygen generator, or a wall connection in a hospital that delivers oxygen via a flow meter. At the other end, the flexible tube terminates into one or more open-ended ports designed to be inserted into the nostrils and/or the mouth. Oxygen flows from the source, through the tube and out through the open-ended ports as a means to supplement breathing. The open-ended ports may vary in size depending on the desired flow rate of oxygen.
[0003] As generally shown in FIG. 1 , the cannula is positioned to provide oxygen through one or more ports positioned near the wearer's nostrils. The flexible plastic tube of the cannula wraps around the cheeks toward the ears. In most cases, the flexible plastic tube of the cannula sits in the space or channel formed between the ear and the scalp—doing so can cause skin irritation, as described in more detail below. Furthermore, the flexible plastic tube of the cannular wraps around behind the ear and comes back toward the front area of the neck, by the chin, for travel back to the oxygen source. In this configuration, the cannula typically does not inadvertently fall out of the patient's nostrils and/or mouth through casual movement.
[0004] The problem is that the plastic material of the cannula typically remains compressed against the skin between the ear and the scalp and after a while the plastic material tends to stick to the skin. Constant contact can cause indentations in the skin, redness, sores or other skin irritations, especially if the skin-to-plastic contact does not allow the skin to breathe underneath. In this respect, if the flexible plastic tube sticks to the skin, the wearer can tear the skin in and around the ear when the cannula moves (e.g., by turning your head). This problem is exacerbated by the fact that nasal cannula are often used or worn by elderly patients whose skin may produce insufficient quantities of oil to keep the external area of the skin lubricated in a manner that prevents or lessens sticking. Placing the plastic tube on open sores or against torn skin is particularly painful and does not allow for healing.
[0005] As such, several products have been developed to help solve the problem of skin irritation around the ears associated with cannula usage. But, these products have drawbacks of their own. For example, the E-Z Wrap Soft Foam Ear Protectors for Oxygen Nasal Cannulas (1-Pair), made by Salter Labs of 100 W. Sycamore Road, Arvin, Calif. 93203, are 3-inch soft closed-cell foam tubes having an inner diameter relatively larger than the external diameter of the cannula tube such that the cannula tube can be inserted therein through a slit down one side of the foam tube. The foam tube covers the portion of the plastic cannula tubing that sits over a portion of the ear when the oxygen cannula is worn. In this respect, the E-Z Wraps are designed to improve comfort and help prevent chafing and soreness. But, this product does not stay in place and tends to easily slip down along a portion of the cannula tube such that it is no longer in position. Additionally, the straight and relatively stiff structure of the foam tube has a tendency to dislodge from the curved area of the ear because the straight foam tube is non-conforming thereto. This too may cause the E-Z Wrap to slide down the flexible plastic tube of the cannula such that it is no longer in a position to protect the ear from the irritating plastic flexible tube of the cannula. As a result, this product may be a nuisance or not work at all, especially for active users. Some solutions have included applying an adhesive, such as tape, to prevent such movement, but this is not ideal.
[0006] Accordingly, there is a need in the art for a cannula support that is flexible so as to be selectively attachable to the cannula, may be adjusted or bent to fit or conform to the exterior surface of the curved area of the ear where the cannula sits and is supported when worn, is comfortable, and prevents substantial skin-to-plastic contact that may otherwise cause skin irritation. The present invention fulfills these needs and provides further related advantages.
SUMMARY OF THE INVENTION
[0007] The cannula support disclosed herein includes a helical cord flexible along its length to permit selective axial displacement of adjacent coils for insertion of a cannula tube therein. In this respect, the support preferably includes a plurality of elastic coils that conform to a curved exterior surface of a cannula tube by expanding along a major or outer diameter and contracting without bunching along a minor or inner diameter of the curved cannula tube. To permit prolonged skin contact without substantial irritation thereof, the helical cord is preferably made from a breathable material such as a polyester outer sheath made from a series of interwoven spiral-bound fibers forming a porous material that permits moisture to vent from the skin surface. This aspect of the cannula support is advantageous over the prior art in that known devices cause irritation, as described herein. Furthermore, this outer sheath of the cannula support preferably has a coefficient of friction that substantially prevents sliding movement along the length of the cannula tube when mounted thereon.
[0008] In an alternative embodiment, the helical cord includes an inner diameter relatively smaller than the exterior surface of the cannula tube. This feature further prevents unwanted sliding movement along the length of the curved exterior surface of the cannula tube. In this respect, the plurality of coils may taper in diameter along a common axis of the helical cord to provide a better fit. To this extent, the taper may be in a conical shape. Alternatively, for example, the helical cord may be made from at least a portion of a curled shoelace, or at least have a common shape therewith. The helical cord should be of a thickness sufficient to bias the cannula tube away from skin contact when the cannula tube is worn and may include an inner cord made from cotton, polyester, or other like material surrounded by the softer or relatively more pliable polyester outer sheath. The helical cord should be sized for easy slide-fit reception between a wearer's ear and scalp.
[0009] In an alternative embodiment, the cannula support includes a helical cord having a plurality of elastic coils that conform to a curved exterior surface of a cannula tube by expanding along a major diameter and contracting without bunching along a minor diameter. The helical cord is flexible along its length to permit selective axial displacement of adjacent coils for insertion of the cannula tube therein. Preferably, the helical cord is made from a breathable material that permits prolonged skin contact substantially without causing irritation thereof and includes a thickness sufficient to bias the cannula tube away from skin contact when the cannula tube is worn.
[0010] Further to this embodiment, the helical cord may include an inner diameter relatively smaller than the exterior surface of the cannula tube to enhance the fit thereto. This may be especially beneficial when used in conjunction with a helical cord that includes a inner cord made from cotton, polyester, or other like material and a polyester outer sheath having a series of interwoven spiral-bound fibers forming a porous material permitting moisture to vent from the skin—a polyester outer sheath having a coefficient of friction designed to substantially prevent sliding movement of the cannula support along the length of the cannula tube when mounted thereon. Further to this extent, the plurality of coils may taper in diameter along a common axis of the helical cord to form, for example, a conical shape. In one embodiment, the helical cord may be made from at least a portion of a curled shoelace and is preferably sized for slide-fit reception between a wearer's ear and scalp.
[0011] In an additional embodiment, the cannula support includes a helical cord that includes at least a portion of a curled shoelace flexible along its length to permit selective axial displacement of adjacent coils for insertion of a cannula tube therein. The helical cord is preferably of a thickness sufficient to bias the cannula tube away from skin contact when the cannula tube is worn. To this extent, the helical cord is also sized for slide-fit reception between a wearer's ear and scalp and is made from a breathable material having a coefficient of friction substantially preventing sliding movement along the length of the cannula support while permitting prolonged skin contact substantially without irritation when mounted thereon. In this embodiment, the helical cord also includes a plurality of elastic coils that taper in diameter along a common axis and conform to a curved exterior surface of the cannula tube by expanding along a major diameter and contracting along a minor diameter. The helical cord may include an inner cord made from cotton, polyester, or other like material and a polyester outer sheath having an inner diameter relatively smaller than the exterior surface of the cannula tube. The polyester outer sheath may include a series of conically-shaped interwoven spiral-bound fibers forming a porous material permitting moisture to vent from the skin.
[0012] Other features and advantages of the present invention will become apparent from the following more detailed description, when taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings illustrate the invention. In such drawings:
[0014] FIG. 1 is a perspective view illustrating a patient wearing a nasal-cannula including a flexible tube wrapped around an ear;
[0015] FIG. 2 is a perspective view of a cannula support as disclosed herein;
[0016] FIG. 3 is a perspective view of the cannula support of FIG. 2 partially uncoiled;
[0017] FIG. 4 is an environmental perspective view illustrating attachment of the cannula support to the flexible tube;
[0018] FIG. 5 is a perspective view illustrating the cannula support fully attached to the flexible tube;
[0019] FIG. 6 illustrates placement of the cannula support behind the ear; and
[0020] FIG. 7 illustrates the cannula support positioning the flexible tube of the cannula in substantial non-contact relation with the skin in and around the ear.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] As shown in the drawings for purposes of illustration, the present invention for a cannula support is referred to generally by the reference number 10 in FIGS. 2-7 . In this respect, the support 10 may be used in association with a cannula that consists of a somewhat slender and elongated tube 12 ( FIG. 1 ) that extends from a device such as an oxygen tank, a portable oxygen generator, or a wall connection in a hospital that delivers oxygen via a flow meter (not shown) at one end to one or more open ended branches or ports 14 at the other end designed to be inserted into, for example, a nostril 16 to deliver supplemental oxygen to a patient in need of respiratory help. Oxygen flows from the source, through the flexible tube 12 and out through one or more of the open-ended branches or ports 14 as a means to supplement breathing. The open-ended branches or ports 14 may vary in size depending on the desired flow rate.
[0022] As generally shown in FIG. 1 , the branches or ports 14 of the cannula flexible tube 12 are positioned near the nostrils 16 to provide oxygen thereto. From here, the cannula flexible tube 12 wraps around the cheeks of the wearer 22 toward the ears 18 . As such, the flexible plastic tube 12 may extend into a space or channel 24 formed between the head 20 and a portion of the outwardly extending ear 18 . The cannula flexible tube 12 then wraps around the ear 18 , comes back toward the front of the neck by the chin and travels back to the oxygen source. The tube 12 is typically made from a somewhat flexible plastic material that can be manipulated in a manner that allows conformity around the wearer's facial features, for example the exterior curvature of the face and around the ear 18 , to streamline the fit of the cannula to the wearer 22 as shown in FIG. 1 .
[0023] The support 10 disclosed herein is a supplemental attachment for the cannula flexible tube 12 as it is designed to reduce or eliminate the aforementioned problems associated with skin-to-plastic contact with the flexible tube 12 . That is, the support 10 helps reduce indentations that may form in and around the skin from constant contact with the flexible tube 12 , reduce redness, sores or other skin irritations, and reduce or eliminate tearing of the skin resultant from the flexible tube 12 sticking to the skin.
[0024] FIG. 2 illustrates one embodiment of the support 10 in the form of a curled or coiled cord that may be formed by winding strips of material around a cylinder to create the shown helical shape. Preferably, the support 10 comprises a form of elastic material (e.g., polyester) that permits stretching or uncoiling when loaded ( FIG. 3 ), while also returning to its natural length ( FIG. 2 ) when unloaded. The helical shape of the support 10 shown in FIGS. 2-7 produces a smooth three-dimensional curve with each coil initially aligned along a common central axis 30 ( FIG. 3 ). While the support 10 in FIGS. 2-7 is substantially cylindrical in shape, it could be made into a conical shape by winding it around a cone, for example. In this respect, the ends 26 , 28 of the support 10 may taper inwardly toward the exterior circumference of the flexible tube 12 to provide a tighter fit thereto at each of the ends 26 , 28 . This embodiment may prevent the support 10 from sliding along the length of the flexible tube 12 , as is problematic with the E-Z Wraps.
[0025] The shape, structure and materials of the support 10 are, in one embodiment, comparable to or the same as the outer polyester material of curly or spiral shoelaces. In this respect, the support 10 may similarly include a tight inner core that helps maintain or form the outer polyester material into the spiral or helical shape of the support 10 . The outer layer preferably includes the aforementioned polyester material, but a person of ordinary skill in the art will readily recognize that the outer layer of the support 10 may be made from various types of materials, such as cotton, nylon, polyester, spandex, etc. Of course, the support 10 may include only the outer polyester material or both the outer polyester material with the harder inner core. In this respect, the outer polyester material may be configured to naturally coil itself, as disclosed herein.
[0026] The elasticity of the support 10 allows it to be bent, curved, extended, retracted, etc. as generally shown in FIGS. 3-7 . In this respect, material selection is important so that the support 10 can adequately conform to the outer curved surface of the ear ( FIGS. 6 and 7 ) to bias the plastic tube 12 away from contacting the skin. The support 10 may also enhance the positional stability of the cannula in and around the ear 18 by increasing the traction therewith while comfortably contacting the skin without causing irritation thereto. The substantially spiral or helical shape of the support 10 made from polyester (or a comparable material) accomplishes these objectives.
[0027] For instance, FIG. 4 illustrates the support 10 being bent and turned around the exterior of the flexible tube 12 . In this embodiment, the inner diameter formed by the helical structure of the support 10 is approximately the same size as the outer diameter of the flexible tube 12 . This allows the wearer 22 to comfortably slide or spiral bind the support 10 along the length of the flexible tube 12 to properly locate and place the support 10 to attain a comfortable fit behind the ear 18 , as shown in FIG. 7 . The inner diameter of the support 10 may, alternatively, be somewhat smaller than the outer diameter of the flexible tube 12 to enhance frictional contact therebetween during use. This, of course, will tend to inhibit movement of the support 10 along the length of the flexible tube 12 relative to a support 10 with a larger diameter. In another alternative embodiment, the support 10 may have a somewhat larger inner diameter at or near its mid-section 32 (generally shown in FIG. 2 ) that terminates at respective conically shaped ends 26 , 28 . This embodiment may provide enhanced contact at each end 26 , 28 , while allowing greater adjustability in the larger diameter mid-section 32 .
[0028] As shown in FIG. 5 relative to FIG. 4 , the support 10 is flexible enough to be wound around the exterior of the flexible tube 12 . In one embodiment, the support 10 attached to the flexible tube 12 , as shown in FIG. 5 , may be a two inch piece of curled shoelace with the harder interior cord removed. Once attached, the wearer may manipulate the shape and placement of the flexible tube 12 with the support 10 mounted thereto. In this regard, FIG. 5 illustrates the support 10 partially curved and shaped to conform to the curved exterior surface of the ear 18 . Placement behind the ear 18 in this manner, and as shown in FIG. 7 , permits the support 10 to bias the inner plastic flexible tube 12 away from contacting the skin in and around the ear 18 to prevent or stop the aforementioned skin irritations. Since the support 10 is curled around the exterior of the flexible tube 12 , it does not fall off when bent around the ear 18 . In this respect, the curled helical shape not only grips to portions of the flexible tube 12 to prevent slippage, as described above, but it also provides enhanced traction against the skin in the area in and around the ear 18 . Additionally, the polyester clothing-type material made from a series of interwoven spiral-bound fibers allows the skin to breath underneath (similar to clothing) and does not have the same abrasive surface interaction with the skin as does the plastic material of the flexible tube 12 . Accordingly, the support 10 stays on the flexible tube 12 until purposefully unwrapped, provides adequate stability, and causes virtually no skin irritation.
[0029] Moreover, the spiral or helical shape of the interwoven fibers of the support 10 provides the flexibility necessary to conform to the outer curvature in and around the ear 18 while providing sufficient traction against the skin without irritation. In this respect, each of the coils of the support 10 may expand ( FIG. 2 ) or contract ( FIG. 3 ) and bend along the central axis 30 thereof ( FIG. 3 relative to FIGS. 6-7 ). A solid foam material, such as the E-Z Wrap design, is unable to flex in this manner because the solid material bunches and prevents interior curving, and otherwise does not permit exterior stretching in the same manner that a series of spaced apart and flexible/bendable helical coils provide. This shape and structure of the support 10 further enhances gripping action in and around the ear 18 so that the support 10 and the flexible tube 12 do not slip or slide out from this space or channel 24 when worn by the wearer 22 . That is, the coils are able to bend with the flexible tube 12 so as to remain in some constant frictional contact therewith such that each of the individual coils are no longer necessarily aligned with the central axis 30 .
[0030] Several individuals using a nasal-cannula have used the support 10 disclosed herein as an alternative to using bandages to cover areas around the ears that were torn and bleeding from the irritation of the cannula flexible tube 12 . In each case, the individual was able to use the support 10 for at least six months without having any of the aforementioned problems associated with skin irritation in and around the ears. Of course, the support 10 would be beneficial to those who use oxygen, and especially those who must be on oxygen all day and all night.
[0031] Although several embodiments have been described in detail for purposes of illustration, various modifications may be made without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited, except as by the appended claims.
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The cannula support includes a helical cord flexible along its length to permit selective axial displacement of adjacent coils for insertion of a cannula tube therein and a breathable material that permits prolonged skin contact substantially without irritation. Furthermore, the cannula support includes an exterior surface having a coefficient of friction substantially preventing sliding movement along the length of the cannula tube when mounted thereon.
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FIELD OF THE INVENTION
[0001] This invention relates to a pneumatic rubber tire having a sidewall and/or tread made predominantly of synthetic rubber (“SR”) a major proportion by weight of which is a relatively low molecular weight high cis-1,4-polybutadiene (“cis-1,4-PBD”) rubber, so termed because its “cis” content is at least 90 percent, with a relatively broad molecular weight distribution “Mw/Mn” or “polydispersity”. The remaining rubber is natural rubber (“NR”) used in minor proportion relative to the SR. Such a sidewall shows improved fatigue performance; moreover, the sidewall compound has better processing characteristics relative to others compounded with a high cis-1,4-PBD polymer but having lower polydispersity and higher number average molecular weight Mn, with polymer chains which are less branched. A sidewall made with the composition (sidewall compound) of the invention also shows improved resistance to propagation of a cut (“cut growth”), and better tear resistance (tear strength) which is also exhibited in a tread; the novel tread compound exhibits better tear resistance than that exhibited by a tread made with any other cis-1,4-PBD having essentially the same Mooney viscosity, all other ingredients being the same.
BACKGROUND OF THE INVENTION
[0002] State of the art pneumatic rubber tires are typically prepared with a rubber tread on a toroidal carcass having a sidewall which extends between and connects opposite sides of the tread to opposed spaced apart wire beads. As a tire is driven over pavement it is flexed continuously, the higher the load carried by the tire and the higher its speed, the greater the strain imposed which causes higher stress during dynamic flexing. A cut in the sidewall tends to grow faster as the strain and resultant stress levels increase. In addition, a sidewall of a tire used on a typical automobile is subjected to weathering, and scuffing against curbs when the car is being parked. The combination of high strain and resultant high stress accelerates damage caused by heat buildup and ozone degradation.
[0003] Though such degradation also takes its toll on the tread, tear resistance of a tire's tread is of greater importance and even a small improvement thereof is deemed a substantial contribution to the tread's performance. In U.S. Pat. No. 6,046,266 Sandstrom et al teach an improved tread composition containing precipitated silica and a combination of trans-1,4- and cis-1,4-PBD but did not suggest that the substitution of any particular cis-1,4-PBD might contribute any particularly desirable property.
[0004] To obtain a desirable balance of properties the art has modified both the NR and SR components in a blend, as well as the relative amounts used of each, and the blend contains various antiozonants/antioxidants (hereinafter, together, “antidegradants”), fillers and curing agents. Choosing the best components for a sidewall recipe is complicated by the requirement that not only they be co-curable in a particular range of temperature, but also that they be compatible when cured. Over the years, improvements have made the modern high speed passenger tire reliable, rugged and affordable. Because fatigue performance of current sidewall compounds is already highly satisfactory, the ability to improve sidewall performance further is not easily achieved.
[0005] U.S. Pat. No. 5,451,646 to Castner disclosed that the use of p-styrenated diphenylamine or hexadiene effectively reduced the molecular weight of the cis-1,4-polybutadiene (“cis-1,4-PBD”) produced with a conventional organonickel-based “catalyst package”. Unlike with cis-1,4-PBD produced by conventional organometal catalysts, a cis-1,4-PBD produced with p-styrenated diphenylamine as the molecular weight reducer in the catalyst package has produced unexpectedly good performance characteristics in a sidewall. It is believed that an arylamine affects the structural activity of organonickel-based catalyst packages which are a combination of an organonickel compound, an organoaluminum compound and a fluorine-containing compound, as disclosed in U.S. Pat. No. 4,983,695 to Kuzma et al. Other organometal-based catalyst packages may be modified to produce polymer chains of cis-1,4-PBD having a more dendritic (branched) structure than those produced with hexadiene.
[0006] Though the high cis-1,4-PBD produced with the amine or hexadiene modifiers had a cis-content in excess of 95 percent, there is no suggestion that the molecular architecture of the PBDs was either similar or different. Castner disclosed he found it unnecessary to oil-extend the '646 cis-1,4-PBD to improve its processability, indicating it processed as if it had a lower molecular weight than other high cis-1,4-PBDs. One skilled in the art would know that a lower molecular weight polymer will process more easily than the same polymer having a higher molecular weight. Castner did not suggest that either the polydispersity or the branched chain structure of the mass of one high cis-1,4-PBD was different from that of another; or that the properties of a compounded rubber would depend upon the molecular architecture of the cis-PBD produced; or that the molecular architecture had a critical influence in the compound; or that the molecular architecture was controlled by the organometal-based catalyst package with which the cis-PBD was produced.
[0007] Therefore one would not expect that a particular high cis-1,4-PBD would have a substantially different compounding effect compared with that of any other high cis-1,4-PBD of essentially the same molecular weight but different molecular architecture, in particular, its dendritic structure, its hydrodynamic volume and its polydispersity. In particular, it was unexpected that a first high cis-1,4-PBD having essentially the same Mooney viscosity as a second high cis-1,4-PBD would provide worse performance characteristics than the second, mainly because the second had a lower Mn, a higher polydispersity and a greater degree of branching.
[0008] U.S. Pat. No. 5,244,028 to Segatta et al. teaches that a precipitated silica filler having a BET surface area of between 100 and 250 square meters per gram and a pH in the range 4.0 to 6.5 improves the properties of conventional antidegradants in a sidewall composition, regardless of which synthetic rubbers are used in the composition. Segatta et al. disclose that mixtures of NR and PBD may be used, as well as mixtures of the various types of PBD including a high cis-1,4-PBD wherein at least 90 percent of its butadiene repeat units are a cis-1,4-isomeric structure, and other synthetic rubbers such as medium vinyl PBD having from 40 to about 60 percent 1,2-vinyl repeat units, and trans-1,4-PBD having at least 65 percent trans-1,4 repeat units. It focussed the effect of a particular filler but failed to suggest that any particular high cis-1,4-PBD might inculcate better performance characteristics than another. They could not have known that a nickel-based catalyst package in which an arylamine was used as a molecular weight reducer, produced a relatively low molecular weight high cis-1,4-PBD which had a higher polydispersity and higher degree of branching than others of comparable viscosity. The degree of branching is measured in a 0.1 percent concentration of polymer in a solution of tetrahydrofuran (THF), as a ratio of light scattering to refractive index. The light scattering and refractive index measurements are made at the outlet of a GPC column. The results are corroborated by measurements of solution viscosity in a solvent such as THF or toluene, such solvent molecules having a higher affinity for high cis-1,4-PBD molecules than a Θ (theta) solvent.
[0009] Since the branched chain structure of high cis-1,4-PBD molecules of approximately the same Mooney viscosity would be expected to have substantially the same molecular weight, irrespective of the process by which each was prepared, there was no reason in the prior art to expect that a particular high cis-1,4-PBD might have a structure which was so different as to change both, the properties and the processing characteristics of the sidewall compound, both substantially; the art failed to recognize that the fatigue performance characteristics of a sidewall compound could be affected by tailoring the molecular architecture of the synthetic rubber component.
SUMMARY OF THE INVENTION
[0010] It has been discovered that a mass of high cis-1,4-PBD which has a higher degree of branching and a higher heterogeneity index (“HI”, also referred to as molecular weight dispersity or polydispersity) than those of other high cis-1,4-PBDs, results in compounding properties found highly desirable in a rubber component of a sidewall or a tread.
[0011] It is therefore a general object of this invention to provide a sidewall or tread compound made with from 55 to 70 phr (parts per hundred parts of all rubber present) of high HI, high cis-1,4-PBD (referred to as a “high HI cis-1,4-PBD”) having a unique branched chain molecular structure, the remaining rubber being NR; the virgin “high HI cis-1,4-PBD” (not extended or diluted to lower its viscosity) has a Mooney in the range from about 40 to 55, a number average molecular weight Mn in the range from about 100 to 150, a polydispersity or HI in the range of from about 3 to 5, and a degree of branching (ratio of light scattering response to refractive index in THF) in the range from about 2 to 3.5.
[0012] It is also a general object of this invention to tailor the SR content of a sidewall or tread compound with a PBD having a polydispersity in the range from about 3 to 5; to improve both “tensile strength (or break strength)” and “elongation percent at break” of the sidewall compound, each in the range from about 7 percent to 17 percent, compared to those of a sidewall compound made with a high-cis-1,4-PBD having essentially the same Mooney viscosity; and to improve the tear resistance of the tread compound in the range from about 10 percent to 15 percent compared to that of a tread compound made with a high-cis-1,4-PBD having essentially the same Mooney viscosity.
[0013] In a specific example, the “high HI cis-1,4-PBD” has at least a 90 percent cis- content, preferably greater than 95 percent, and most preferably an essentially “all cis-” structure; an essentially “all cis-” structure refers to one in which less than 3 percent of all the molecules have a structure which is not cis-1,4-; most preferred is a PBD having about 98 percent cis- content, the remaining being trans- and/or vinyl PBD.
[0014] It is another specific object of the invention to provide a rubber tire with a sidewall or tread having NR in a minor proportion by weight relative to the synthetic rubber (“SR”) in it; the SR contains a major proportion of “high HI cis-PBD” having the properties given above. The sidewall exhibits unexpectedly superior resistance to flexural fatigue and cut growth compared to a sidewall containing another high cis-PBD with comparable Mooney but lower polydispersity and a lower degree of branching; the tread exhibits unexpectedly superior tear resistance while maintaining substantially the same other properties of a state-of-the-art tread made with another cis-1,4-PBD. The less the relative amount of the high HI cis-1,4-PBD with respect to any other SR present, the less the perceived benefit of the '646 high cis-1,4-PBD.
[0015] It is a more specific object of this invention to provide a pneumatic tire having a sidewall or tread made with a compound consisting essentially of more than 50 phr of synthetic rubber and less than 50 phr of NR; further, the synthetic rubber consists essentially of a major amount of high HI cis-1,4-PBD, the remaining synthetic rubber being selected from the group selected from commercially available high cis-1,4-PBD not a high HI cis-1,4-PBD; other conventionally used ingredients being used in amounts generally used.
[0016] It is another general object of this invention to provide a pneumatic tire having a sidewall or tread made from a compound having both improved “tensile strength (or break strength)” and “elongation percent at break”, using a high HI cis-1,4-PBD to provide a greater improvement in the amount of energy under a curve plotting tensile strength against percent elongation at break than that which is provided by a sidewall compound having a lower HI and a lower degree of branching than other high cis-1,4-PBDs having the same Mooney viscosity.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] This invention produces a pneumatic tire comprising a generally toroidal carcass with a circumferential tread, shaped beads and a sidewall extending between the tread and beads. The compound from which the tire's sidewall is made preferably comprises less than 50 phr NR and more than 50 phr of synthetic rubber, the latter containing a major proportion by weight of high HI cis-1,4-PBD and a minor proportion by weight of another synthetic PBD; less than 10 phr of an antidegradant; from about 35 to 65 phr of carbon black; less than 5 phr of a tackifier resin and/or a peptizer; less than 15 phr total, of each of a processing aid, typically an aromatic, naphthenic, and/or paraffinic processing oil, zinc oxide, wax, preferably a mixture of microcrystalline waxes; a fatty acid, typically stearic acid.
[0018] The compound from which the tire's tread is made preferably comprises less than 50 phr NR and more than 50 phr of synthetic rubber, the latter containing a major proportion by weight of high HI cis-1,4-PBD and a minor proportion by weight of another synthetic PBD; about 40 to about 80 phr of an inert reinforcing filler, preferably a combination of carbon black and precipitated silica, carbon black being present in a major proportion by weight of the filler; a suitable coupling agent; a rubber processing oil; and other conventionally used ingredients including antidegradants, accelerators, etc. in amounts typically used. The novel tread compound is most preferably prepared in three stages; and it is cooled to ambient (room) temperature after each stage. The high HI cis-1,4-PBD may also be used in compounds for the production of tread base, wire coat, ply coat, chafer, wedge and apex components of a tire.
[0019] The high HI cis-1,4-PBD most preferred is made by polymerizing 1,3-butadiene in the presence of an organonickel or organocobalt (“organo-Ni/Co”) compound, an organoaluminum compound, a fluorine containing compound, and para-styrenated diphenylamine; wherein the organoaluminum compound and the fluorine containing compound are brought together at a temperature in the range from about −10° C. to about 120° C. in the presence of the para-styrenated diphenylamine. Typically a trialkylaluminum compound, and hydrogen fluoride (HF) or a HF complex are used with an organo-Ni/Co compound, most preferably a nickel salt of a carboxylic acid and from 0.25 phm (parts by weight per hundred parts of monomer) to about 1.5 phm of the para-styrenated diphenylamine. Further details are provided in the '646 patent the disclosure of which is incorporated by reference thereto as if fully set forth herein.
[0020] The antidegradant is selected from the group consisting of amines, phenolics, quinolines and mixtures thereof, microcrystalline and paraffinic waxes having melting points in the range from about 30° C. to about 100° C. such as are disclosed in The Vanderbilt Rubber Handbook (1990), Pages 366 and 367. Typical antioxidants include diphenyl-p-phenylenediamine and others, such as, for example, those disclosed in The Vanderbilt Rubber Handbook (1990), Pages 343 through 362. Typical antiozonants include N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine available as Santoflex 6PPD from The Flexys Company, and others disclosed in The Vanderbilt Rubber Hand - book (1990), Pages 363 through 365. Typical peptizers include pentachlorothiophenol and dibenzamidodiphenyl disulfide. Choice of the appropriate additives and their relative amounts is well within the skill of a rubber compounder and only incidental to the invention which is primarily directed to the utilization of a high HI cis-1,4-PBD as a major constituent of the synthetic rubber portion of a sidewall or tread.
[0021] Vulcanization is effected by a sulfur vulcanizing agent. Examples of suitable sulfur vulcanizing agents include elemental sulfur (free sulfur) or sulfur donating vulcanizing agents, for example, an amine disulfide, polymeric polysulfide or sulfur olefin adducts. Preferably, the sulfur vulcanizing agent is elemental sulfur. As known to those skilled in the art, sulfur vulcanizing agents are used in an amount ranging from about 0.5 to about 4 phr, or even, in some circumstances, up to about 8 phr, with a range of from about 1.5 to about 2.25 being preferred.
[0022] Accelerators are used to control the time and/or temperature required for vulcanization and to improve the properties of the vulcanizate. In one embodiment, a single accelerator system may be used, i.e., primary accelerator. Conventionally, a primary accelerator is used in amounts ranging from about 0.5 to about 2.0 phr. In another embodiment, combinations of two or more accelerators which is generally used of which the primary accelerator is usually used in the larger amount (0.5 to 1.0 phr), and a secondary accelerator which is generally used in smaller amounts (0.05 to 0.50 phr) in order to activate and to improve the properties of the vulcanizate. Combinations of these accelerators have been known to produce a synergistic effect of the final properties and are generally preferred over the use of either accelerator alone. In addition, delayed action accelerators may be used which are not affected by normal processing temperatures but produce satisfactory cures at ordinary vulcanization temperatures. Suitable types of accelerators that may be used in the present invention are amines, disulfides, guanidines, thioureas, thiazoles, thiurams, sulfenamides, dithiocarbamates and xanthates. Preferably, the primary accelerator is a sulfenamide. If a second accelerator is used, the secondary accelerator is preferably a guanidine, dithiocarbamate or thiuram compound. As with other conventional ingredients the use of a sulfur vulcanizing agent and accelerator(s) is only incidental to the tire constructed with the specified NR and SR components.
[0023] The process conditions and equipment for producing the sidewall compound are conventional; a first essentially homogeneous blend is preferably produced in a first non-productive stage by mixing at a temperature in the range from about 130° C. to 170° C. for from about 1 to 10 min, allowed to cool to ambient temperature, then, in a second productive stage, blended at a temperature in the range from about 80° C. to 120° C. for from about 1 to 4 min, until essentially homogeneous with an antidegradant(s), sulfur and accelerator(s).
[0024] In the following Table A is listed side-by-side, the properties of three virgin high cis-1,4-PBDs obtained from The Goodyear Tire & Rubber Company, and each of which was used in identical amounts in a recipe for a sidewall compound.
TABLE A Budene ®1207 Budene ®1208 Budene ®1280 cis- content, percent 98 98 98 trans- content, percent 1 1 1 vinyl content, percent 1 1 1 Tg, ° C. −105 −104 −104 Mooney 54 45 45 Mn × 10 −3 251 209 127 Mw × 10 −3 532 481 445 HI 1 2.1 2.3 3.5 DB 2 1.6 1.6 2.88
[0025] The DB ratio is determined by dissolving the PBD in THF to yield a 0.1 percent concentration solution, and measuring the ratio of its light scattering response in a GPC column to its refractive index.
[0026] The tire of this invention can be built, shaped, molded and cured by any desirable conventional method used by one skilled in the art. The invention may be better understood by reference to the following example in which the parts and percentages are by weight unless otherwise indicated.
[0027] In the following examples “phr” refers to parts per 100 parts of rubber, the rubber not including any other compounding ingredients, and each PBD has a cis-1,4- content greater than 95 percent; “high” HI refers to an HI in the range from 3 to 5; high degree of branching refers to a ratio in the range from 2 to 3.5.
EXAMPLES
[0028] Three sidewall compositions are prepared containing 60 phr of high-cis-1,4-PBD and 40 phr NR by being mixed with carbon black and conventional processing aids in two stages, a non-productive (first) stage and a productive (second) stage, under conditions set forth in Table 1 below. Each high cis-1,4-PBD is made with a nickel-based catalyst package to yield an essentially all-cis-content. The compounds are identified as follows:
[0029] Compound A: made with essentially all-cis-1,4-PBD having a relatively higher molecular weight than the other two all-cis-PBDs as evidenced by a Mooney viscosity of 55; it is well known that the weight average molecular weight Mw of PBD is directly proportional to its Mooney viscosity.
[0030] Compound B: made with an essentially all-cis-1,4-PBD having a relatively lower molecular weight (Mooney viscosity of 45) than the all-cis-1,4-PBD used in Compound A.
[0031] Compound C: the compound of this invention, is made with an essentially all-cis-1,4-PBD high HI cis-1,4-PBD having a molecular weight (Mooney viscosity of 45) essentially the same as that of the all-cis-1,4-PBD used in Compound B, but having higher polydispersity and a higher degree of branching than either of the all cis-1,4-PBDs used in compounds A or B.
TABLE 1 Compound No. A B C Non-Productive Stage Natural rubber 40 40 40 High cis 1,4-PBD 1 (55 Mooney) 60 0 0 High cis-1,4-PBD 2 (45 Mooney) 0 60 0 High HI cis-1,4-PBD 3 (45 Mooney) 0 0 60 Carbon black (ASTM N550) 50 50 50 Processing Oil 4 10 10 10 Wax 1.5 1.5 1.5 Zinc oxide 3 3 3 Fatty Acid 1.5 1.5 1.5 Antiozonant + Antioxidant 5 5.5 5.5 5.5 Productive Stage Accelerator (sulfenamide type) 0.5 0.5 0.5 Sulfur 2 2 2
[0032] First stage processing of each of the foregoing compounds was as follows:
Compound No. A B C Work, MJ/m 624 615 575 Torque, Kg 4.1 4.0 3.6 Power, KW 1.8 2.0 1.6 Dump Temp., ° C. 130-170 130-170 130-170
[0033] Second (Productive) Stage processing conditions were as follows:
Compound No. A B C Work, MJ/m 359 372 343 Torque, Kg 3.7 3.7 3.5 Power, KW 1.1 1.2 1.0 Dump Temp., ° C. 80-120 80-120 80-120
[0034] [0034] TABLE 2 Properties of the Sidewall Compounds Compound No. A B C Modulus, 100% 1.53 1.48 1.38 Modulus, 150% 2.32 2.23 2.08 Modulus, 200% 3.51 3.37 3.17 Modulus, 300% 6.86 6.68 6.33 Break Strength, MPa 12.94 13.77 14.76 Elongation at Break (%) 502 536 586 Energy, J 99.0 109.4 129.66
[0035] The above data indicate the break strength of C is 7 percent and 14 percent better than those for B and A respectively; and the percent elongation at break of C is 9 percent and 17 percent better than those for B and A respectively.
[0036] The value of Energy, J is calculated as the area under the curve of a plot of “break strength (or tensile strength)” against “percent Elongation at Break”.
[0037] It is evident that the Energy value (129.66 J) for Compound C is about 19 percent greater than the Energy value (109.4 J) for Compound B, each compound being made with the identical components to have the same Mooney, except that Compound C was made with high HI cis-1,4-PBD. Note that the break strength and percent elongation at break were only about 10 percent higher for Compound C than the values for Compound B.
TABLE 3 Properties of Compared Sidewall Compounds Compound No. A B C Hardness at 23° C., Shore A 53 53 50 Hardness at 100° C., Shore A 48 48 46 Rebound at 23° C., ASTM D-1024 63 62 60 Rebound at 100° C., ASTM D-1024 69 68 67 Specific gravity 1.094 1.093 1.095
[0038] As one would expect, the specific gravity and Rebound of each Compound A, B and C is essentially the same as the only variable is the unique polymer structure generated by the organonickel catalyst package.
[0039] Crack growth resistance is measured by a Pierced Groove Flex test conducted at 93° C. at 360 cycles/min using a conical piercing needle {fraction (1/32)}″ in diameter using a 6″×1.5″×0.25″ sample using 180° flex wherein the flex region is a ¼″ diameter molded groove against the grain of the sample. The results after defined intervals of 15 min and multiples thereof are set forth in Table 4 below.
TABLE 4 Crack Growth Resistance by PG Flex Compound No. A B C 15 min 1,1,1 1,1,1 1,1,1 30 min 1,1,1 1,1,1 1,1,1 60 min 1,1,3 1,1,3 1,1,1 120 min 1,1,8 1,1,8 1,1,1 180 min 2,2,12 1,6,13 1,1,1 240 min 4,8,23 1,23,31 1,1,1
[0040] Tear resistance is measured by a peel adhesion value (at 95° C. to self), to indicate a predictive measure of ultimate tear strength. The steady state (SS) tear resistance of the sidewall compound with Budene® 1280 was 139 Newtons as set forth below:
Compound No. A B C Tear Resistance, SS, Avg. Load, N 113 128 139
[0041] Most notably, both PG Flex and Tear Resistance are substantially better for Compound C than for A and B, indicating better crack growth resistance and tear resistance. As shown, tear resistance was improved over those for B and A in the range from about 8 percent to 23 percent respectively.
[0042] The improved tear resistance exhibited in compound C is also exhibited in a comparison of tread compounds: Compound D made with Budene® 1208; and Compound E, the novel tread compound, made with Budene® 1280, as follows:
[0043] Each tread compound was made in three stages, first and second non-productive stages followed by a productive stage using ingredients, given as phr based on 100 parts of all rubber present. In the first stage, ingredients are mixed in a Banbury® mixer for from about 1 to 10 min at a temperature in the range from about 150° C. to 170° C., until essentially homogeneous; in the second stage the ingredients are mixed for from about 1 to 10 min at a temperature in the range from about 140° C. to 160° C.; and in the third (productive) stage the ingredients are mixed for from about 1 to 4 min at a temperature in the range from about 90° C. to 110° C.; the time for mixing in each stage depends upon the ease with which the mass becomes essentially homogeneous. Moreover, it will be understood that the number of non-productive stages used for producing either the sidewall or the tread is not narrowly critical, depending upon several factors of commercial importance, and the number illustrated herein are deemed optimal for typical factors.
[0044] In the first non-productive stage the following ingredients were mixed for about 2.5 min at 160° C. in a Kobe Banbury® mixer:
Compound No. D E NR 20 20 Budene ®1208 80 0 Budene ®1280 0 80 Carbon black, N-121 30 30 Processing oil 5 5 Wax (blend) 1.5 1.5 Zinc oxide 3 3 Fatty acid 3 3
[0045] The blended stock is cooled to ambient temperature (23° C.) and then, in the second non-productive stage, the following ingredients were mixed for about 2 min at 150° C. in the same mixer:
Compound No. D E Carbon black, N-121 30 30 Antiozonant 2.5 2.5
[0046] The blended stock is cooled to room temperature (23° C.) and then, in the productive (third) stage, the following ingredients were mixed for about 2 min at 104° C. in the same mixer:
Compound No. D E Sulfenamide accelerator 1.5 1.5 Sulfur 1.4 1.4 DPG accelerator 6 0.2 0.2
[0047] [0047] TABLE 5 Properties of compared tread compounds Compound No. D E Break Strength, MPa 15.9 15.77 Elongation at Break (%) 424 426 Modulus, 300% 10.5 10.3 Hardness at 23° C., Shore A 70 69 Hardness at 100° C., Shore A 62 60 Rebound at 23° C., ASTM D-1024 47 45 Rebound at 100° C., ASTM D-1024 55 53 Tear Resistance, SS, Avg. Load, N 169 193
[0048] The above data indicate the tear resistance of E is about 14 percent better than that of D and all other properties are essentially the same.
[0049] The pneumatic tires of the present invention may be radial or bias. Preferably, the tires are radial.
[0050] While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.
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Sidewalls of a pneumatic tire have greater resistance to failure due to dynamic flexing and abrasion, and the tire's tread has better resistance to tearing than with conventionally used rubber compositions, when sidewalls and tread are formed from a compound having a major proportion by weight of synthetic rubber (SR) and a minor proportion by weight of natural rubber (NR), and a major proportion by weight of the SR itself consists essentially of a high cis-1,4-polybutadiene having defined molecular architecture. The high cis-1,4-PBD has more than 90 percent cis- structure, a poly-dispersity in the range from about 3 to 5, a number average molecular weight Mn in the range from 100,000 to 150,000 and a degree of branching in the range from 2 to 3.5. The sidewall compound has characteristics quite different from one made with a typical commercially available high cis-1,4-PBD; and the tread has excellent tear strength. The dendritic structure of the high HI cis-1,4-PBD molecules has an unexpectedly beneficial effect on the performance characteristics of the sidewall and tread, particularly important in a high-performance automobile tire.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to processes for the desulfurization of petroleum products during the refining process or otherwise before combustion, and particularly to a laser-based method for the removal of sulfur, particularly in the form of dimethyldibenzothiophene, in hydrocarbon fuels.
[0003] 2. Description of the Related Art
[0004] Clean desulfurization of hydrocarbon fuels is an important issue due to environmental concerns (green house effect, acid rain, ozone depletion) and compliance with the regulations set by international agencies, controlling the environment. Sulfur content in transportation fuel (diesel) is an environmental concern because upon combustion, sulfur is converted to SO x during combustion, which not only contributes to acid rain, but also poisons the catalytic converter installed in modem automobiles for exhaust emission treatment.
[0005] Due to these concerns, drastic changes and stringent regulations were implemented in many countries concerning diesel and gasoline. Currently the fuel specifications for all highway traffic in the U.S., Japan, and Western Europe limit the sulfur content of the diesel to be less than 500 ppm. The new regulations in many countries will further lower the contents of sulfur in diesel fuels. By the year 2006, the sulfur content in diesel has to be reduced to less than 15 ppm and to less than 30 ppm in gasoline.
[0006] For this purpose, various techniques, such as hydrogenation and caustic treatment, have been developed to reduce the sulfur contents in hydrocarbon fuels. These conventional hydro-desulfurization (HDS) methods can remove a major portion of the sulfur from diesel fuels, but they are unable to remove the so-called “hard sulfur”, i.e., the sulfur that is strongly bonded in a polycyclic aromatic sulfur compound. In order to meet the 15 ppm specifications for diesel in the future, hard sulfur contents, such as dimethyldibenzothiophene (DMDBT), must be removed from diesel and other feed stocks and products.
[0007] The conventional hydrodesulfurization (HDS) process for removing easy sulfurs and polycyclic aromatics has been adopted on a commercial scale. Easy sulfurs include non-thiophenic sulfur (elemental sulfur, disulfides, mercaptans, etc.), but not thiophenes, benzothiophenes, and dibenzothiophenes in which the substituents are away from the sulfur heteroatom. In the conventional HDS process, polycyclic aromatics with more than one aromatic ring are mostly reduced to polynuclear aromatics having a single aromatic ring (e.g., tetralins). Thus, there is a strong demand for removing hard sulfurs from a large number of polynuclear aromatics.
[0008] Conventional techniques have their own technical limitations and cost effectiveness (octane loss) to reduce certain sulfur compounds, such as 4,6 dimethyldibenzothiophene, which is a major obstacle to bringing down the sulfur level to <15 ppm limit.
[0009] Due to the above mentioned reasons, there is a continuing vital interest in the development of approaches to ultra-clean diesel fuels by deep desulfurization and deep dearomatization. The procedures of sulfur removal are mostly related to degradation of the most stubborn sulfur-containing contaminants, which are benzothiophenes, particularly 4,6-dimethyldibenzothiophene, and they involve catalytic desulfurization and photolytic oxidation of this family of compounds.
[0010] Recent photochemical approaches for desulfurization of hydrocarbon fuels involve photochemical oxidation of sulfur-containing hydrocarbons by conventional UV or visible radiation sources (lamps). The sulfur-containing hydrocarbons are oxidized when suspended in aqueous-soluble solvent (e.g., acetonitrile), and the oxidation products are concentrated in this solvent due to their higher polarity. The exploration of these processes by Hirai et al., Ind. Eng. Chem. Res ., Vol. 36, pp. 530-533 (1997) and Shiraishi et al., Ind. Eng. Chem. Res ., Vol. 37, pp. 203-211 (1998); Vol. 38, pp. 3310-3318 (1999); Vol. 40, pp. 293-303; and J. Chem. Eng. of Japan , Vol. 32, No. 1, pp. 158-161 (1999) revealed the ensuing features of these processes:
[0011] (i) The photochemical excitation of benzothiophenes is diminished in the presence of naphthalene, which is due to triplet energy transfer from the photoexcited benzothiophenes to the ground state naphthalene;
[0012] (ii) Photo-oxidation is assisted by a triplet photosensitizer (9,10-dicyanoanthracene);
[0013] (iii) The desulfurization is improved by introducing hydrogen peroxide into the contact water phase, since H 2 O 2 acts as a weak oxidizing reagent of the photoexcited benzothiophenes and also makes the triplet energy transfer between benzothiophenes and naphthalene less efficient.
[0014] Although these photo-oxidation approaches are efficient for removing sulfur from light oils, catalytically cracked gasoline, and vacuum gas oils, their application in industry is not obvious due to problems in the separation of the solvent, the oxidized products and the sensitizer. The products of photo-oxidation of benzothiophenes in water are benzothiophene carboxylic acids, and the major mechanism of photochemical degradation of dibenzothiophene in aqueous solution is the oxidation of a benzo ring to form benzothiophene dicarboxylic acid and opening the thiophene ring, leading to sulfobenzoic acids.
[0015] A somewhat promising process for application purposes appears to be a conventional photochemical desulfurization in a hydrogen peroxide aqueous solution extraction system that is suited for high sulfur-content-straight-run light gas oil and aromatic-rich light cycle. However, this procedure is performed through the use of a high-pressure mercury lamp for direct excitation of sulfur-containing compounds, and results in a decreased sulfur content only after very prolonged (36 hours) irradiation.
[0016] These photochemical desulfurization processes reported so far are unfortunately suppressed in the presence of aromatic compounds (2-ring aromatics) and are therefore too slow with substituted dibenzothiophenes. This finding is in line with the commonly considered relative feasibility of sulfur compounds to undergo desulfurization. The reactivities decrease in the order thiophenes>benzothiophenes>dibenzothiophenes.
[0017] None of the above publications, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus, a laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
[0018] The laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels provides for deep desulphurization of hydrogen fuels through the elimination of dimethyldibenzothiophene (DMDBT) from hydrocarbon fuels. The method involves photoexciting atomic or molecular oxygen to a singlet or triplet energy state, mixing the photoexcited oxygen with the hydrocarbon fuel, and irradiating the hydrocarbon fuel with UV radiation from a tunable laser source at a wavelength corresponding to an absorption band of dimethyldibenzothiophene. The hydrocarbon fuel may be in a liquid or an aerosol state. The oxygen may be provided by pure oxygen gas, by N 2 O, or by air, and may be diluted by an inert carrier gas, such as N 2 . Exemplary wavelengths of the laser radiation include 193 nm, 248 nm, and 266 nm. Sulfur is eliminated from DMDBT as elemental sulfur or gaseous sulfides and sulfur oxides, which are easily separated from the hydrocarbon fuels.
[0019] The method is particularly effective in removing 4,6-dimethyldibenzothiophene, a compound present in hydrocarbon fuels that is resistant to conventional methods of removing sulfur from hydrocarbon fuels due to steric hindrance of the sulfur in thiophene. However, the method is also effective in removing other alkyl substituted dibenzothiophenes. The reaction is thought to proceed by oxidation of triplet dimethyldibenzothiophene by the photoexcited oxygen. The formation of triplet dimethyldibenzothiophene is enabled by the ability to tune the laser to the very narrow wavelength required to excite DMDBT without also exciting other aromatic compounds that are also present in hydrocarbon fuels. Photoexcitation of the oxygen may occur simultaneously with laser irradiation of the DMDBT, i.e., the order of the steps is not critical.
[0020] Hydrocarbon fuels desulfurized by the laser-based method of the present invention may be produced in greater yield and with less deterioration in quality than hydrocarbon fuels desulfurized by conventional methods. The hydrocarbon fuel may be gasoline, diesel fuels, kerosene, fuel oils, and any other hydrocarbon fuel that may be derived from petroleum or petroleum products. The laser-based method of the present invention may be used in combination with, or as a supplement to, conventional desulfurization processes used to remove mercaptans, disulfides, and other simpler sulfur compounds from hydrocarbon fuels.
[0021] These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a reaction scheme for a laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels according to the present invention.
[0023] FIG. 2 is an alternative reaction scheme for a laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels according to the present invention.
[0024] FIG. 3 are absorption spectra showing the extent of desulfurization as a function of time with irradiation from an ArF laser in a laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels according to the present invention.
[0025] FIG. 4 is a chart showing the extent of desulfurization as a function of time with irradiation at 241 nm in a laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels according to the present invention.
[0026] FIG. 5 are absorption spectra showing the extent of desulfurization with irradiation from a KrF laser at 248 nm in a laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels according to the present invention, the spectrum (a) showing the absorption spectrum before irradiation and the spectrum (b) showing the absorption spectrum after one minute of irradiation.
[0027] FIG. 6 is a chart showing depletion as a function of fluence in a laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels according to the present invention.
[0028] FIG. 7 are absorption spectra showing selective degradation of 4,6 DMDBT in the presence of naphthalene in a laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels according to the present invention, spectrum A showing the absorption spectrum of a mixture of DMDBT before irradiation and spectrum B showing the absorption spectrum of the mixture after 20 seconds irradiation at 248 nm.
[0029] FIG. 8 is absorption spectra showing depletion as a function of pulse duration with irradiation at 266 nm in a laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels according to the present invention.
[0030] FIG. 9 are absorption spectra showing the effect of H 2 O 2 and oxygen gas on degradation of DMDBT in a laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels according to the present invention.
[0031] FIG. 10 are absorption spectra showing the effect of oxygen on depletion of DMDBT in a laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels according to the present invention, spectrum (a) showing the absorption spectrum before radiation and spectrum (b) showing the absorption spectrum after irradiation.
[0032] Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] The present invention is a laser-based method for removal of sulfur, and particularly dimethyldibenzothiophene, in hydrocarbon fuels. The method was developed by studying oxidative photodegradation of 1,6-dimethyldibenzothiophene using intense laser irradiation at 150≦λ≦530 nm. The method is based on laser irradiation of benzothiophenes in the presence of such compounds as atomic oxygen (O), molecular oxygen (O 2 ), air, and nitrous oxide (N 2 O) that can be laser-photolysed into very reactive oxidative reagents that can react with benzothiophenes to yield photo-oxidation products that finally degrade into hydrocarbons and sulfur/sulfur oxide.
[0034] Two major research schemes were investigated. These are laser-induced photo-oxidation of dibenzothiophenes with molecular oxygen in an excited state ( 1 O 2 ) and laser-induced photo-oxidation of dibenzothiophenes with atomic oxygen in highly reactive states like O ( 1 D). The excited molecular state and atomic oxygen states can be generated by selective excitation of molecular oxygen and nitrous oxide using a tunable UV laser.
[0035] FIG. 1 shows a first reaction scheme for carrying out the laser-based method of the present invention. In this reaction scheme, molecular ( 1 O 2 ) is generated through interaction of triplet benzothiophene with 3 O 2 , which is simply ensured by laser excitation of benzothiophene in the presence of triplet molecular oxygen or air. The use of laser monochromatic radiation makes possible selectively exciting dibenzothiophenes, and leaves most other aromatic hydrocarbons not activated for reaction with 3 O 2 due to tuning the laser wavelength to specific absorption bands of dibenzothiophenes.
[0036] FIG. 2 shows an alternative reaction scheme for carrying out the laser-based method of the present invention. This alternative reaction scheme is based upon (i) the photochemical decomposition of nitrous oxide into atomic oxygen and molecular nitrogen i.e.,
[0000] N 2 O+ h ν→O( 1 D)+N 2
[0000] and on (ii) the high reactivity of O atoms towards thiophene in the gas phase (or in an aerosol system). Here the oxygen atom is generated by photo-dissociation of N 2 O using an ArF laser.
[0037] The rate constant for the reaction of atomic oxygen with thiophene is 300 times higher than that with benzene, but is similar to that with alkenes. The course of the reaction of oxygen with sulfur-containing organic molecules proceeds via an initial addition of oxygen to the sulfur atom. N 2 O is soluble in organic solvents and could be photolysed by laser radiation, and thus induce reaction of atomic oxygen with dibenzothiophenes. This reaction is faster than that with aromatic compounds and comparable to that with hydrocarbons.
[0038] It is expected that the oxygen atom reacts with hydrocarbons via addition to multiple bonds and via H-abstraction. These reactions lead to the formation of hydroxide radical that can undergo further reaction with hydrocarbons to finally produce H 2 O, lower-molecular weight hydrocarbons, and oxygenated hydrocarbons. The hydroxide radical reaction with benzothiophene is expected to be initiated by addition to the aromatic ring.
[0039] In this alternative reaction scheme, laser oxidative cleavage could lead to aromatic compounds with S—O and SO 2 groups, as indicated in FIG. 2 , and also further cleavage (extrusion of sulfur-containing fragments). These reactions could be accompanied with oxidation of unsaturated hydrocarbons present in hydrocarbon fuels.
[0040] The effect of the oxidizing reagent could partly consist in the laser-induced (transient) formation of hydroxide radical that can induce a chain photo-oxidation of DMDBT in the liquid phase. This reaction could occur in a specific way, so that DMDBT depletion occurs within intervals longer than the laser irradiation interval.
[0041] The laser-based method of the present invention provides for UV laser-induced degradation of 4,6dimethyldibenzothiophene either in the absence or in the presence of hydrogen peroxide and molecular oxygen. This process enables the degradation of 4,6-dimethyldibenzothiophene by tuning the laser irradiation particularly and preferentially to 4,6-dimethyldibenzothiophene absorptions bands, and thus to achieve a preferential decomposition of this compound. The principle of selective irradiation/preferential decomposition of 4, 6dimethyldibenzothiophene is enabled by the different absorption spectra of fuel contaminants. The inventors completed several experiments to demonstrate the ability of the laser photolytic process to the remove 4,6-dimethyldibenzothiophene from model hydrocarbon compounds.
[0042] A special reaction chamber for the removal of DMDBT was designed and fabricated locally. The irradiation experiments for removal of DMDBT were carried out in different vessels and the following protocols were adopted.
[0043] N 2 O or O 2 or synthetic air was bubbled through the hydrocarbon solution of DMDBT using a gas dispersion tube.
[0044] A hydrocarbon solution of DMDBT was introduced to a vessel containing gases (N 2 O, O 2 or air) at reduced pressures through a capillary tube.
[0045] Droplets of hydrocarbon solution of DMDBT (aerosol) were introduced into the irradiated zone of a vessel in a stream of N 2 O or O 2 diluted with inert carrier gas.
[0046] The N 2 concentration was considerably higher than that of N 2 O to prevent complications from the reaction: O+N 2 O→2NO.
[0047] In detail, a special Pyrex® (Pyrex is a registered trademark of Corning, Incorporated of Corning, N.Y.) cell of 1 ml volume, equipped with optical grade quartz windows for the transmission of UV and visible laser beams, was used. The cell was equipped with some ports and rubber septums for sampling. Keeping in view the importance of the main experimental parameters and their effect on the desulfurization process, the first step was to see the laser wavelength dependence, duration of laser exposure and the laser energy for maximum removal of DMDBT in a model compound like hexane and naphthalene. The above-mentioned parameters were optimized. The tuning range studied for the optimization of the laser wavelength was 150≦λ≦530 nm, while for optimization of laser energy, the range studied was 30-150 mJ/cm 2 . The irradiated DMDBT solutions or aerosols were analyzed by UV absorption spectrometry, gas chromatography and mass spectrometry-gas chromatography (GC/MS) to determine the final products of the photochemical oxidative degradation. Care was taken to determine photochemical efficiency of the photo-oxidative degradation of DMDBT.
[0048] Four different kinds of lasers were employed as a tunable light source. These include 355 and 266 nm wavelength laser beams generated by the third and fourth harmonics of a Spectra Physics Nd:YAG Laser (Model GCR 250), a 193 nm laser beam generated from an ArF Excimer Laser (Lambda Phys Model EMG 201), and a 248 nm laser beam generated from a KrF excimer Laser (Lambda Phys Model EMG 201). The pulse width of these lasers was in the 8-20 nano second range with a 10 Hz repetition rate. The laser beam was directed into the center of the reaction chamber using a set of mirrors. For all the measurements, the laser beam diameter was kept constant. This precaution was taken to ensure the exposure of the same volume of the hydrocarbon fuels, and to study the parametric dependence under the same photon intensity.
[0049] Specific experiments were performed to study the removal of sulfur containing compound DMDBT, which are described below as different examples.
EXAMPLE 1
DMDBT Removal as a Function of Laser Irradiation Time Using ArF Laser
[0050] Laser irradiation (at 193 nm having incident pulse energy of 34 mJ and repetition rate of 10 Hz) of a 10 −4 M solution of 4,6-dimethyldibenzothiophene in c-hexane (cyclohexane) in a standard UV spectral grade cell (1 ml in volume) for 4 minutes resulted in an almost complete degradation of 4,6-dimethyldibenzothiophene, as shown by FIG. 3 , and yields, as identified by mass spectral analysis, volatile gaseous hydrocarbons (ethyne, ethane, propene) and aromatic hydrocarbons, along with elemental sulfur.
EXAMPLE 2
DMDBT Removal in Different Solvents Using ArF Laser (193 nm)
[0051] Laser irradiation (193 nm, incident pulse energy 70 mJ, 10 Hz) of the 6×10 −5 M and 8×10 −5 M solutions of 4,6-dimethyldibenzothiophene in c-hexane, tetrahydrofuran and acetonitrile in a UV spectral cell (1.5 ml in volume) resulted in a 30-35% degradation of 4,6-dimethyldibenzothiophene within 1 minute, as shown in FIG. 4 . The degradation of 4,6-dimethyldibenzothiophene in these solvents proceeds at similar rates and is not affected by the presence of hydrogen peroxide.
[0052] In FIG. 4 , Solution A is 1.5 ml of an 8×10 −5 M solution of DMDBT in c-hexane, Solution B is 1.5 ml of a 6×10 −5 M solution of 4,6-dimethyldibenzothiophene in acetonitrile, and Solution C is 1.5 ml of an 8×10 −5 M solution of 4,6-dimethyldibenzothiophene in c-hexane containing 1.5 μl of 10 −2 M H 2 O 2 in water and intensely stirred during laser irradiation.
EXAMPLE 3
Degradation of 4,6-dimethyldibenzothiophene Using KrF Laser
[0053] Laser irradiation (248 nm, incident pulse energy 60 m], 10 Hz) of a 5×10 −6 M solution of 4,6-dimethyldibenzothiophene in c-hexane (UV spectral grade) in a standard UV spectral cell (4 ml in volume) for 40 seconds resulted in an almost complete degradation of 4,6-dimethyldibenzothiophene, as shown in FIG. 5 .
EXAMPLE 4
Effect of Laser Power on DMDBT Removal
[0054] The efficiency of the KrF laser-photolytic depletion of 4,6-dimethyldibenzothiophene is linearly dependent on the incident laser fluence, as shown in FIG. 6 . This implies that the degradation takes place as a 1 photon-induced process.
EXAMPLE 5
DMDBT Removal in C-Hexane and Naphthalene Model Hydrocarbons
[0055] Laser irradiation (248 nm, incident pulse energy 60 mJ, 10 Hz) of a solution obtained by mixing 2 ml of a 2.5×10 −6 M solution of 4,6-dimethyldibenzothiophene in hexane and 2 ml of a 0.75×10 −5 M solution of naphthalene in hexane for 20 seconds in the 4 ml spectral cell resulted in a complete degradation of 4,6-dimethyldibenzothiophene and much slower degradation of naphthalene, as shown in FIG. 7 . This example shows the effect of tuning the radiation into 4,6-dimethyldibenzothiophene absorption band and reveals that other aromatic compounds are also degraded (but less efficiently) with 248 nm radiation.
EXAMPLE 6
DMDBT Removal Monitored Using GC Analysis
[0056] Laser irradiation (248 nm, incident pulse energy 200 mJ, 10 Hz) for 15 minutes of 25 ml of 4×10 −3 M solution of 4,6-dimethyldibenzothiophene in c-hexane placed in a quartz tube opened to air atmosphere results in complete degradation of 4,6-dimethyldibenzothiophene and development of a yellow color (elemental sulfur). The major products identified by GC/MS technique were toluene, phenol, 2-methylpropylbenzene, 1-ethylbutylbenzene, 1-methyl-1-pentylbenzene, p-mentha-2,5-dien-7-ol, 1,4-dihydrophenylmethanol, n-hexylbenzene, 1,2-dimethylpropoxybenzene, n-hexylphenyl ether, diphenyl, 1-hexanol, and 2,5-hexanediol, which confirms homolytic formation of radicals, their coupling reactions and reactions with air (oxygen). The results also show that there were cleavage reactions of the solvent.
EXAMPLE 7
Nd:YAG Laser Degradation of 4,6-dimethyldibenzothiophene Under Air Atmosphere
[0057] Irradiation of 4 ml of A 0.8×10 −6 M solution of 4,6-dimethyldibenzothiophene in c-hexane (in spectral cell) for 6 minutes at a wavelength of 266 nm generated by the fourth harmonic of an Nd:YAG laser (Spectra Physics, Model GCR 10, incident pulse energy 40 mJ, 10 Hz) resulted in a complete depletion of 4,6-dimethyldibenzothiophene, as shown in FIG. 8 . The arrows indicate the depletion of 4,6-dimethyldibenzothiophene at about 240 nm and a build-up of photolytic products at around 190 nm.
EXAMPLE 8
Nd:YAG Laser Degradation of 4,6-dimethyldibenzothiophene Under Molecular Oxygen (O 2 ) Atmosphere
[0058] A mixture of 25 ml of a 6.8×10 −6 M solution of 4,6-dimethyldibenzothiophene in c-hexane together with 25 ml of 30% H 2 O 2 in H 2 O was placed in a photochemical reactor equipped with quartz window and O 2 was intensely bubbled through the vigorously stirred phases. Simultaneous irradiation at 266 nm (incident pulse energy 35 mJ, repetition frequency 10 Hz) for 10 minutes resulted in about 80% depletion of 4,6-dimethyldibenzothiophene, as shown in FIG. 9 .
EXAMPLE 9
Nd:YAG Laser Degradation of 4,6-dimethyldibenzothiophene Under Intense Bubbling of (O 2 )
[0059] 25 ml of 6.8×10 −6 M solution of 4,6-dimethyldibenzothiophene in c-hexane was contained in a photochemical reactor equipped with quartz window and oxygen was intensely bubbled through the vigorously stirred solution. Simultaneous laser irradiation at 266 nm (incident pulse energy 35 mJ, repetition frequency 10 Hz) for 20 seconds resulted in a complete depletion of 4,6-dimethyldibenzothiophene, as shown in FIG. 10 .
[0060] It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
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The laser-based method for removal of sulfur (DMDBT) in hydrocarbon fuels provides for deep desulfurization of hydrogen fuels through the elimination of dimethyldibenzothiophene (DMDBT) from hydrocarbon fuels. The method involves photoexciting atomic or molecular oxygen to a singlet or triplet energy state, mixing the photoexcited oxygen with the hydrocarbon fuel, and irradiating the hydrocarbon fuel with UV radiation from a tunable laser source at a wavelength corresponding to an absorption band of dimethyldibenzothiophene. The hydrocarbon fuel may be in a liquid or an aerosol state. The oxygen may be provided by pure oxygen gas, by N 2 O, or by air, and may be diluted by an inert carrier gas, such as N 2 . Exemplary wavelengths of the laser radiation include 193 nm, 248 nm, and 266 nm. Sulfur is eliminated from DMDBT as elemental sulfur or gaseous sulfides and sulfur oxides, which are easily separated from the hydrocarbon fuels.
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COPYRIGHT NOTICE
[0001] A portion of the disclosure of this patent document contains material, which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. The following notice applies to the software and data as described below and in the drawings hereto: Copyright © 2002, Sun Microsystems, Inc., All Rights Reserved.
FIELD OF INVENTION
[0002] The present invention generally relates to the field of authentication. More specifically, an embodiment of the present invention provides for passing authentication between users.
BACKGROUND OF INVENTION
[0003] As the Internet becomes increasingly a part of everyday life, the number of users utilizing the Web to perform commercial transactions (such as e-commerce) is growing exponentially. The always-available services through Web pages are contributing to this growth. For example, a user in a different time zone than a service provider does not have to worry about the customer service hours of operation when utilizing a Web site-based customer service tool. As a result of its many benefits, e-commerce is envisioned to become more commonplace than traditional commerce in the coming years.
[0004] Larger companies are also actively participating in the commercial use of the Internet. One problem with today's Internet-based solutions, however, is that an authenticated entitlement is not readily transferable between users or entities. For example, to pass an entitlement from an originating user to a receiving user, the target user needs to already be a registered user on the system utilized by the originating user. In other words, to pass authentication, the originating or receiving users need to first create an account (or provide a set of data) for the receiving user. Once the account is created, the originating user may pass an entitlement to the receiving user. The steps involved in traditional authentication of users can be cumbersome and time-consuming.
[0005] Also, the traditional authentication transfer methods allow transfer within the system that authorizes the receiving user. This limitation can be a problem because such internal system transfers may not always be the most efficient, flexible, or convenient way of transferring authentication between users.
[0006] Furthermore, the limitations imposed by the traditional system transfers prevent free commercial transactions by resellers. For example, resellers who are in the business of buying from a seller and selling to a purchaser are not able to readily pass authentication due to, for example, the limitations posed by the traditional authentication transfer systems.
SUMMARY OF INVENTION
[0007] The present invention, which may be implemented utilizing a general-purpose digital computer, in certain embodiments of the present invention, includes novel methods and apparatus to provide efficient, effective, and/or flexible passage of authentication between users. In accordance with an embodiment of the present invention, a method of passing authentication between a plurality of users is disclosed. The method includes: creating a token; associating the token with an entitlement; passing the token to a target user without having to first establish that the target user is a registered user; the target user presenting the token for redemption; authenticating the token; and if the token is authenticated, providing the entitlement to the target user in a same session.
[0008] In another embodiment of the present invention, an expiration of the token may be different than an expiration of the entitlement corresponding to the token.
[0009] In a further embodiment of the present invention, a computer system for passing authentication between a plurality of users is disclosed. The system includes: a user environment to request an entitlement; a system environment to create a token associated with the entitlement; and a token management service coupled to the system environment to authenticate the token.
[0010] In yet a further embodiment of the present invention, the token may be passed to a target user without having to first establish that the target user is a registered user.
[0011] In a different embodiment of the present invention, if the token is authenticated by the token management system, the entitlement may be provided to the target user in a same session.
[0012] In one other embodiment, the authentication may also be used to associate the entitlement with the target user for use in subsequent sessions. In such use, the expiration period of the token could be relatively far shorter than that of the entitlement.
BRIEF DESCRIPTION OF DRAWINGS
[0013] The present invention may be better understood and its numerous objects, features, and advantages made apparent to those skilled in the art by reference to the accompanying drawings in which:
[0014] [0014]FIG. 1 illustrates an exemplary computer system 100 in which certain embodiments of the present invention may be implemented;
[0015] [0015]FIG. 2 illustrates an exemplary token management system 200 in accordance with an embodiment of the present invention; and
[0016] [0016]FIG. 3 illustrates an exemplary token state diagram 300 in accordance with an embodiment of the present invention.
[0017] The use of the same reference symbols in different drawings indicates similar or identical items.
DETAILED DESCRIPTION
[0018] In the following description, numerous details are set forth. It will be apparent, however, to one skilled in the art that embodiments of the present invention may be practiced without these specific details. In other instances, well-known structures, devices, and techniques have not been shown in detail, in order to avoid obscuring the understanding of the description. The description is thus to be regarded as illustrative instead of limiting.
[0019] Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least an embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
[0020] Also, select embodiments of the present invention include various operations, which are described herein. The operations of the embodiments of the present invention may be performed by hardware components or may be embodied in machine-executable instructions, which may be in turn utilized to cause a general-purpose or special-purpose processor, or logic circuits programmed with the instructions to perform the operations. Alternatively, the operations may be performed by a combination of hardware and software.
[0021] Moreover, embodiments of the present invention may be provided as computer program products, which may include machine-readable medium having stored thereon instructions used to program a computer (or other electronic devices) to perform a process according to embodiments of the present invention. The machine-readable medium may include, but is not limited to, floppy diskettes, optical disks, compact disc-read only memories (CD-ROMs), and magneto-optical disks, read-only memories (ROMs), random-access memories (RAMs), erasable programmable ROMs (EPROMs), electrically EPROMs (EEPROMs), magnetic or optical cards, flash memory, or other types of media or machine-readable medium suitable for storing electronic instructions and/or data.
[0022] Additionally, embodiments of the present invention may be downloaded as a computer program product, wherein the program may be transferred from a remote computer (e.g., a server) to a requesting computer (e.g., a client) by way of data signals embodied in a carrier wave or other propagation medium via a communication link (e.g., a modem or network connection). Accordingly, herein, a carrier wave shall be regarded as comprising a machine-readable medium.
[0023] [0023]FIG. 1 illustrates an exemplary computer system 100 in which certain embodiments of the present invention may be implemented. The system 100 comprises a central processor 102 , a main memory 104 , an input/output (I/O) controller 106 , a keyboard 108 , a pointing device 110 (e.g., mouse, track ball, pen device, or the like), a display device 112 , a mass storage 114 (e.g., a nonvolatile storage such as a hard disk, an optical drive, and the like), and a network interface 118 . Additional input/output devices, such as a printing device 116 , may be included in the system 100 as desired. As illustrated, the various components of the system 100 communicate through a system bus 120 or similar architecture.
[0024] In accordance with an embodiment of the present invention, the computer system 100 includes a Sun Microsystems computer utilizing a SPARC microprocessor available from several vendors (including Sun Microsystems, Inc., of Santa Clara, Calif.). Those with ordinary skill in the art understand, however, that any type of computer system may be utilized to embody the present invention, including those made by Hewlett Packard of Palo Alto, Calif., and IBM-compatible personal computers utilizing Intel microprocessor, which are available from several vendors (including IBM of Armonk, N.Y.). Also, instead of a single processor, two or more processors (whether on a single chip or on separate chips) can be utilized to provide speedup in operations. It is further envisioned that the processor 102 may be a complex instruction set computer (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing a combination of instruction sets, and the like.
[0025] The network interface 118 provides communication capability with other computer systems on a same local network, on a different network connected via modems and the like to the present network, or to other computers across the Internet. In various embodiments of the present invention, the network interface 118 can be implemented utilizing technologies including, but not limited to, Ethernet, Fast Ethernet, Gigabit Ethernet (such as that covered by the Institute of Electrical and Electronics Engineers (IEEE) 801.1 standard), wide-area network (WAN), leased line (such as T1, T3, optical carrier 3 (OC3), and the like), analog modem, digital subscriber line (DSL and its varieties such as high bit-rate DSL (HDSL), integrated services digital network DSL (IDSL), and the like), cellular, wireless networks (such as those implemented by utilizing the wireless application protocol (WAP)), time division multiplexing (TDM), universal serial bus (USB and its varieties such as USB II), asynchronous transfer mode (ATM), satellite, cable modem, and/or FireWire.
[0026] Moreover, the computer system 100 may utilize operating systems such as Solaris, Windows (and its varieties such as CE, NT, 2000 , XP, ME, and the like), HPUX, IBM-AIX, PALM, UNIX, Berkeley software distribution (BSD) UNIX, Linux, Apple UNIX (AUX), Macintosh operating system (Mac OS) (including Mac OS X), and the like. Also, it is envisioned that in certain embodiments of the present invention, the computer system 100 is a general purpose computer capable of running any number of applications such as those available from companies including Oracle, Siebel, Unisys, Microsoft, and the like.
[0027] [0027]FIG. 2 illustrates an exemplary token management system 200 in accordance with an embodiment of the present invention. The system 200 includes a user environment 202 and a system environment 204 . The user environment 202 and system environment 204 may be remotely located in accordance with an embodiment of the present invention (for example, on different computer servers located at different data centers). The user environment 202 includes an originator 206 (or originating user) and a target user 208 (or receiving user). The system 204 includes a website and/or an entitlement 210 and a token management service 212 . In one embodiment of the present invention, the originator 206 requests a token from the website 210 . The website 210 requests creation of a token from the token management service 212 . The token management service 212 returns a created token to the website 210 which is then forwarded (e.g., as a token key) to the originator 206 . The originator 206 may then pass the token key created by the token management service 212 to the target user 208 , or otherwise utilize the token key. The target user 208 may then present the token key to the website 210 for redemption. I an alternative embodiment of the present invention, the token service may be accessed by the originator using a mechanism other than the website (e.g. a different website or computer application). For example, an employee may create tokens for publishing in a promotion.
[0028] In an embodiment of the present invention, the website 210 may authenticate the presented token by requesting authentication of the token from the token management service 212 . The token management service may then respond with a yes or a no, for example, to the website 210 indicating whether the presented token is authenticated. By receiving an acknowledgement from the token management service 212 , website 210 may respond to the target user 208 indicating whether the presented token key was authenticated.
[0029] In one embodiment of the present invention, the authentication discussed with respect to FIG. 2 involves the identification of a user to a system, typically so that the system can establish whether the user should have access to an entitlement (such as a purchase, a right to use, access to a user group or account (such as access to join a user group, permission to access a particular account, or functions to be performed on an account), and the like). The token key is envisioned to be the actual data (e.g., text or numbers, or otherwise binary data) passed from one user to another. The originator maybe the user who requests the creation of the token and the target user maybe the user(s) whom the originator wishes to authenticate. According, in accordance with an embodiment of the present invention, a token allows for hand off of entitlement from one user (e.g., the originator) to another user (e.g., the target user). In an alternative embodiment of the present invention, once permission to access the entitlement is granted, the entitlement may be associated with the user and the user may access the entitlement in future sessions without being required to present the token again.
[0030] In another embodiment of the present invention, the passing of authentication can be external to the system 204 . For example, the token key may be published or broadcast using any mechanism that is independent of the system 204 and can pass the token key. Such external methods may include, but are not limited to, electronic mail (e-mail), telephone transmissions, voice mail, written note (e.g., handwritten and/or typed), web confirmation page, faxed transmissions, regular mail, periodic publications (such as news papers or magazines), braille, spoken words, and alike. In a further embodiment of the present invention, the token may be a database record in the system 204 that stores an association with the entitlement corresponding to the token key.
[0031] In accordance with an embodiment of the present invention, the token may include one or more of the following properties (where “->” indicates a pointer to):
[0032] token key or string (numeric/alpha-numeric code)
[0033] token type (e.g., service, invitation, and/or purchase)
[0034] feature
[0035] permissions or role
[0036] authentication identity (ID)->
[0037] service->service entitlement ID
[0038] invitation->group ID
[0039] purchase->line item ID
[0040] expiration (in an embodiment of the present invention, of the token and not the entitlement or permission created)
[0041] account of creator
[0042] usage quantity (number of times the token can be used)
[0043] token status
[0044] Accordingly, in accordance with an embodiment of the present invention, the token may have a status and may be created for one to N authentications. In a further embodiment of the present invention, the authentication ID may point to a combination of other Ids such as service, group (or permission), or line item. In one embodiment of the present invention, the token status may be selected from those discussed (as states) with respect to Table 1 below. Once all authentications are used, the token may be considered as used-up. Also, each type of token may be used within a typical timeframe, for instance a week or a month. For security reasons, a token having a specific type may expire after a given default period. It may be up to the application to determine how the time is set (for example, the application (e.g., 210 ) may ask the token management service 212 to set the time period differently for each type of token, or even differently for each token instance).
[0045] In a further embodiment of the present invention, it is envisioned that the expiration of the token may be different than the expiration of the entitlement corresponding to a token (or of a user's access to the entitlement once it has been authenticated). In an embodiment of the present invention, it is envisioned that the originator 206 may utilize (e.g., present) the token key to the website 210 instead of, or in addition to, the target user 208 .
[0046] In one embodiment of the present invention, the originator 206 may pass the token to the target user 208 without having to first establish that the target user 208 is a registered user on the system 204 . Accordingly, a user may register and gain authentication in the same session. In another embodiment of the present invention, the registration of a user who is trying to present a token key may be an optional step. It is also envisioned, in accordance with another embodiment of the present invention, that a single token may be generated for multiple target users (or for multiple entitlements) and/or multiple tokens may be generated for a same entitlement. The purchase and/or entitlement access may be associated with a user account (and persisted for future sessions in an embodiment of the present invention).
[0047] In accordance with one embodiment of the present invention, there may be three types of tokens. First, a purchase token may be utilized to pass purchaser permissions, for example, from a reseller to a purchaser. Second, a service token may allow a purchaser to pass consumption and/or other permissions to a consumer. Third, an invitation token may permit an administrator of a group to distribute membership and/or permissions to members of the group. Such tokens may include a specific role or permission and point to a specific use in an embodiment of the present invention.
[0048] In a further embodiment of the present invention, the authentication may be performed by an intermediary. For example, a service token may be generated and given to a target user. The target user might telephone a call center for service and give the token key to the call center representative as entitlement for receiving service during the call. The call center representative would then access the system, present the token key, and the system may authenticate the caller and log consumption of the token. In an alternative embodiment of the present invention, the originator 206 may be an internal employee and the token key may be distributed to customers for example for marketing promotions or as part of other bundled products purchased by customers. In a further embodiment of the present invention, the intermediary may be a reseller, agent, sales or account representatives, various customer employees, and the like.
[0049] [0049]FIG. 3 illustrates an exemplary token state diagram 300 in accordance with an embodiment of the present invention. The token state diagram 300 starts at a creation stage 302 which transitions to a valid stage 304 . The token state diagram 300 also includes a locked stage 306 , a used up stage 308 , a canceled stage 310 , and an expired stage 312 . In an embodiment of the present invention, the locked stage 306 may be invoked when requests and usage do not happen relatively simultaneously to, for example, ensure that no more than one user uses up the last token (since only one use should be allowed to finish). Table 1 below summarizes the transitions between the stages of FIG. 3 and the corresponding triggering events.
TABLE 1 Token State Stages State (or Status) Transition to . . . Trigger Valid Valid Quantity remaining more than zero Locked Upon a request, and ((Quantity - number of remaining outstanding) equal zero) Canceled Token Canceled Expired Token Expires Locked Locked Upon successful use, and (Quantity remaining greater than zero) Valid Upon failed use Used Up Upon successful use, and (Quantity remaining equal to zero) Used Up Valid More added to Quantity Canceled Valid(Not likely/not shown) Token Reinitialized Expired Valid(Not likely/not shown) Expiration Extended
[0050] The foregoing description has been directed to specific embodiments of the present invention. It will be apparent to those with ordinary skill in the art that modifications may be made to the described embodiments of the present invention, with the attainment of all or some of the advantages. For example, the techniques of the present invention may be utilized for provision of discounts (such as coupons, vouchers, and the like), royalty points, frequent shopping credit, and the like. Furthermore, portions of the present invention may be published or passed by either human or machine-readable medium, or both. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the spirit and scope of the invention.
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Disclosed are novel methods and apparatus for provision of efficient, effective, and/or flexible passing of authentication between users. In accordance with an embodiment of the present invention, a method of passing authentication between a plurality of users is disclosed. The method includes: creating a token; associating the token with an entitlement; passing the token to a target user without having to first establish that the target user is a registered user; the target user presenting the token for redemption; authenticating the token; and if the token is authenticated, providing the entitlement to the target user in a same session.
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TECHNICAL FIELD
[0001] The present invention is directed to an orthodontic appliance and particularly to orthodontic aligners.
BACKGROUND
[0002] Orthodontic appliances represent a principal component of corrective orthodontic treatment devoted to improving a patient's occlusion. In conventional orthodontic treatment, an orthodontist or an assistant affixes an orthodontic appliance, such as, orthodontic brackets, to the patient's teeth and engages an archwire into a slot of each bracket. The archwire applies corrective forces that coerce the teeth to move into orthodontically correct positions. Traditional ligatures, such as small elastomeric O-rings or fine metal wires, are employed to retain the archwire within each bracket slot. Due to difficulties encountered in applying an individual ligature to each bracket, self-ligating orthodontic brackets have been developed that eliminate the need for ligatures by relying on a movable latch or slide for captivating the archwire within the bracket slot. Conventional orthodontic brackets are ordinarily formed from stainless steel, which is strong, nonabsorbent, weldable, and relatively easy to form and machine. Patients undergoing orthodontic treatment using metal orthodontic brackets, however, may be embarrassed by the visibility of metal, which is not cosmetically pleasing. To address the unsightliness of metal brackets, certain conventional orthodontic brackets incorporate a bracket body of a transparent or translucent non-metallic material, such as a clear or translucent polymer or a clear or translucent ceramic, that assumes the color or shade of the underlying tooth.
[0003] Alternatives to orthodontic brackets include appliances that are not required to be affixed to the patient's teeth. Such appliances include so-called “aligners” that are interchangeable by the patient during treatment. Accordingly, the clinician may prescribe a series of aligners, which are generally placed over but are not themselves adhesively secured or otherwise attached to the patient's teeth, to move one or more teeth from their original position to their aesthetically pleasing position. Typically, a series of aligners is required to fully treat the patient because the degree of movement produced by each individual aligner is limited. As such, when used in a series, each aligner in the series may be designed to fulfill a portion of the treatment process or move one or more teeth over a portion of the entire distance toward the desired position.
[0004] One aligner system is the Invisalign® system available from Align Technology, Inc. The Invisalign® system includes removable aligners that are to be worn by the patient. Generally, these aligners are clear or transparent polymer orthodontic devices that are removably positioned over the teeth of the maxilla and/or the teeth of the mandible. In this system, as treatment progresses, the patient wears an a first aligner having a specific prescription for a period of several days or few weeks, then removes the first aligner and replaces it with a second aligner having a second, different prescription. Each aligner is responsible for moving the teeth toward their final predetermined or aesthetically correct position.
[0005] Patients undergoing treatment with these types of systems often experience a treatment that does not progress as originally anticipated by the clinician. Specifically, at some point during treatment the patient cannot fit the next successive aligner in the series onto his or her teeth. This is generally due to one or more or each of the previous aligners' failing to move one or more of the patient's teeth to the exact prescribed location. When a previous aligner fails to generate the prescribed orientation of the teeth, the subsequent aligner may not fit exactly as planned. As a result, the subsequent aligner may not move the tooth to its final, predetermined position. The tooth is thus at a location other than where it ought to be according to the treatment plan or is misplaced. An accumulation of these individual misplacement errors often prohibits placement of the next aligner in the series. It is typically necessary for the treatment process to be “rebooted” when this occurs. That is, the orthodontist may need to determine the actual position of the teeth by taking a mold thereof or by scanning the teeth. Once the actual tooth position is known, the misplacement error can be determined and one or more additional aligners may be prescribed to correct the uncorrected error of previous aligners. In this way, the new, additional aligners may place the patient back-on-track with the original treatment process. Correcting for errors in movement in the initial treatment process is undesirable as it requires additional visits to the orthodontist's office as well as extends the treatment time, and increases the costs associated with treatment.
[0006] Consequently, there is a need for an orthodontic appliance that moves teeth to their predetermined positions such that error correction is less frequently required. There is also a need for polymeric orthodontic appliance that can endure the biochemical environment found in the oral environment without substantial degradation in mechanical properties or aesthetics, and that does not otherwise negatively impact the patient's teeth during treatment.
SUMMARY OF THE INVENTION
[0007] The above described needs are met in accordance with principles of the present invention, which in one aspect features an orthodontic appliance such as an aligner, or any other appliance of continuously polymeric material having two or more tooth-conforming cavities, which in use is elastically deformed from an initial shape to a deformed shape when fitted upon a patient's teeth, so that the polymeric material generates an initial elastic return stress. Unlike the materials used in the prior art, the appliance material is selected such that it is capable of generating a continuing elastic return stress driving the polymeric material from a deformed shape toward its initial shape even after the polymeric material has been continuously deformed to said deformed shape for more than one day, and in some embodiments, for periods of two weeks or longer.
[0008] In one embodiment, an appliance in accordance with this aspect of the invention generates initial, continuing and ongoing elastic return stresses sufficient to cause remodeling of bone adjacent to the tooth's roots after two weeks, and thereby can generate greater and more accurate tooth movements than appliances made of elastic materials which plastically deform after a short period of time.
[0009] In embodiments disclosed herein, suitable polymeric material are identified, which are characterized by viscoelastic material properties, and a stress relaxation time that is long enough to generate continuing stress sufficient to remodel bone adjacent to an engaged tooth on or after 20 days after the initial installation of the appliance.
[0010] In further aspects, the invention features a method of moving teeth of a patient, comprising applying an appliance as described above to the patient's teeth, so that the appliance elastically deforms and generates an initial and continuing elastic return stress over a period of greater than one day, and in some embodiments, for periods of two weeks or longer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the detailed description given below, serve to explain various aspects of the invention.
[0012] FIG. 1 is a perspective view of one embodiment of the invention;
[0013] FIG. 2 is a photograph of a test fixture used to test various commercially available polymeric materials;
[0014] FIG. 3 is a photograph illustrating the deformation or configuration of strips of polymeric materials obtained through the use of the test fixture depicted in FIG. 2 after two-week (14 day), 5-day, and 2-day tests;
[0015] FIG. 4 illustrates the anatomy of a human tooth and surrounding tissue; and
[0016] FIG. 5 illustrates an orientation of the tooth of FIG. 4 after an aligner is positioned thereon.
DETAILED DESCRIPTION
[0017] In general, one embodiment of the invention includes an orthodontic appliance capable of moving teeth according to a predetermined treatment plan. In particular, the orthodontic appliance may move one or more teeth from one orientation to another which advances the overall orientation of the teeth toward their final aesthetic positions.
[0018] In one embodiment of the invention, a series of individual orthodontic appliances may be utilized for complete orthodontic treatment. Accordingly, each appliance in the series may move one or more teeth a prescribed amount. Cumulatively, these individual amounts may result in complete treatment of the patient's malocclusion.
[0019] By way of example only, in one embodiment, the orthodontic appliance may include an aligner. Such aligners may be similar to those disclosed in U.S. Pat. No. 6,450,807, which is incorporated by reference herein in its entirety, but differ in the polymer from which it is made, as is described in detail below. The aligner may be configured to fit over or encapsulate multiple teeth on one of the mandible or maxilla. It is known that such an aligner may not be secured to the patient's teeth, such as with an adhesive or a fastener. Instead, these aligners may be designed to couple to one or more teeth by virtue of the shape of the aligner itself. In this regard, the patient may be able to remove and reattach the aligner during treatment without the aid of the orthodontist.
[0020] With reference to FIG. 1 , in one embodiment, an aligner 10 may be one of a series of aligners that are prescribed to treat a patient's malocclusion or a portion thereof by moving one or more teeth 12 on the patient's mandible 14 from the misaligned position toward their orthodontically correct position. For instance, the aligner 10 , according to one embodiment of the invention, may move a single tooth 12 from one orientation to another orientation. This movement may be predetermined according to a treatment plan that includes a starting orientation and a final orientation. The starting orientation may be the initial orientation before treatment begins or any of the subsequent, intermediate tooth orientations as determined by a previous aligner or another orthodontic device. The final orientation for any aligner 10 in a series of aligners may include a position that is intermediate between the starting orientation and the final orientation or it may be the aesthetically correct position for the tooth observed at the conclusion of treatment. In this regard, in one embodiment of the invention, a system for treating a malocclusion may include a series of aligners 10 differing in their configuration sufficient to fulfill a predetermined treatment plan. Accordingly, each respective aligner may incrementally move one or more teeth from their misaligned positions toward or to their aesthetically correct or final orientation. While embodiments of the invention include aligners that may not be secured to the patient's teeth with adhesives or such, it will be appreciated that the appliance, according to embodiments of the invention, are includes orthodontic appliances that are adhesively secured to the patient's teeth. Specifically, embodiments of the appliance may be adhesively joined to another orthodontic appliance and/or to the patient's teeth during orthodontic treatment.
[0021] Furthermore, though not shown, it will also be appreciated that the appliance may alternatively be used on the maxilla or on both the maxilla and mandible.
[0022] By way of example, the aligner 10 may be similar in shape to that shown in U.S. Pat. No. 6,450,807. In this regard, the aligner 10 may substantially conform to one or more of the teeth 12 on the jaw 14 over which the aligner is placed. The aligner 10 may encapsulate or nearly replicate the reverse shape of each tooth 12 . However, there may be teeth 12 in contact with the aligner 10 that may not match or conform to the aligner 10 . Accordingly, there may be nonalignment between one or more teeth 12 and the aligner 10 . As a result of the lack of complete alignment between all of the teeth and the aligner 10 , a portion of the aligner 10 may be deformed or strained elastically, and generate an elastic stress. The stress may be tensile, shear, or compressive in nature. This stress typically produces loads in an opposing direction on the respective teeth. During treatment, at least one tooth may move to at least partially alleviate the opposing load. In this manner, desired tooth movement may be achieved.
[0023] To better understand aligner mode of operation and the materials from which current aligners are manufactured, a number of commercially available polymers from which commercially available aligners are made, were tested to determine their resistance to plastic deformation under prolonged deformation in somewhat of a simulated oral environment. In this regard, straight strips (not shown) of each of the materials were cut from vacuum formed aligner analogs originally 0.030 inch (0.75 mm) thick. The polymers tested were 1) Zendura® available from Bay Materials LLC, California, 2) Biocryl available from Great Lakes Lab, and 3) Triplast from Adell Polymers. With reference to FIG. 2 , a sinusoidal (to net a continuum of strains) test fixture 16 was designed to examine the material properties of three current aligner materials (above) in vitro. The fixture 16 consisted of thirty 0.125 inch diameter stainless steel pins 18 pressed into a plastic block on 0.5 inch centers. The fixture 16 consisted of six rows of five of the pins 18 . FIG. 2 is a photo of the fixture 16 with the strips laced between the pins (2 strips of each material). The loaded test fixture 16 was placed in a 37° C. water bath (not shown).
[0024] The typical recommended wear period for the aligners of the above-mentioned materials is about two weeks. As such, for an initial test, each of the strips 20 was held in the water bath laced between the pins 18 for a duration of two weeks. As is shown in FIG. 3 , after two weeks, each of the strips 20 took a “set.” In other words, each polymeric strip 20 took on a plastically deformed shape dictated by the test fixture 16 and essentially conformed to that configuration permanently after two weeks. There was no observable elastic recovery to the initially straight configuration when the strips 20 were removed from the fixture 16 .
[0025] As is also shown in FIG. 3 , the same result was observed after reducing the test duration to 5 days. And, as shown, a 2-day test produced the same result as the 5- and 14-day tests. A 1-day test or 24-hour test (not shown) gave identical results. In sum, each polymeric strip 20 plastically deformed to a set position as determined by the test fixture after the time period indicated. It was observed that after as little as 24 hours in the fixture 16 , none of the strips visually recovered a portion of their initial, straight shape.
[0026] Applicant observed that this characteristic of commercially used materials is problematic and has significant implications for orthodontic treatment. For example, without being bound by theory, as a consequence of the rapid plastic deformation of aligner material, it is thought that the elastic stress load applied by aligners made of these polymers decreases rapidly over the first 24 hours of use. In this regard, while the elastic stress load initially applied is sufficiently high to produce bone remodeling, after 24 hours in vitro, it is suspected that little, if any, load is applied to the teeth by these materials.
[0027] That is, commercially available aligners are nearly ineffective after 24 hours in the patient's mouth. However, it is known that aligners of these polymeric materials move teeth, though commercially available treatment systems have the above-mentioned problems that require them to be rebooted.
[0028] In this regard, the anatomy of the teeth and the surrounding supporting bone may serve to explain the movement of the teeth that is observed despite the now-identified limits of the current aligner materials and may also explain the aforementioned problems of current aligners and treatment with them. With reference to FIG. 4 , it is known that a root 28 of a tooth 22 sits in a socket of lamina dura 24 , which is a relatively thin layer of extremely hard, mostly avascular, cortical bone. The cortical bone is surrounded by a mass of soft, spongy, vascular or trabecular bone 26 . The root 28 of the tooth 22 is attached to the bone 24 by a periodontal ligament (PDL) 30 . The PDL 30 is typically narrowest (0.15 mm) at the middle third of the root 28 and is typically widest occlusally and at the root tip 32 (0.38 mm).
[0029] With reference now to FIG. 5 , when an aligner 34 is placed on the tooth 22 , it moves the tooth 22 until the PDL 30 is compressed against the lamina dura, for example, at 36 and 38 . Because the PDL 30 has viscoelastic-like material properties, it yields under the load applied by the aligner 34 . Viscoelasticity is a material property that describes the deformation of a material having both fluid-like, or viscous, and solid-like, or elastic, characteristics. The bone 24 , 26 may also be thought of as having viscoelastic-like material properties, though the PDL 30 is more fluid-like and, consequently, less solid-like, than the adjacent bone 24 , 26 . The polymer of the aligner 34 may also have viscoelastic material properties in the oral environment.
[0030] Referring now to the polymeric aligner materials tested above in view of FIG. 5 , it is observed that the polymers tested have viscoelastic material properties by which their elastic behavior is between that of the PDL 30 and the respective bone 24 , 26 . Based on this observation, while the PDL 30 yields under the initial load of the aligner 34 , it is the aligner 34 that ultimately yields before the bone 24 remodels to any significant extent. In other words, in the conditions found in the oral environment, the initial elastic stress produced by the initially deformed polymeric aligner 34 is high enough to compress the PDL 30 . However, that initial elastic stress in the aligner 34 is reduced by viscous flow. And, the rate of this stress reduction is high enough that the magnitude of the stress after one day may be lower than that required to maintain compression of the PDL 30 . Thus, the load applied by the aligner 34 is insufficient to cause further tooth movement after one day from the start of treatment.
[0031] In further detail, taking into account the above description, and with continued reference to FIG. 5 , an aligner 34 of the above-mentioned polymers compresses the PDL 30 up against the bone 24 . After 24 hours, the aligner 34 plastically deforms to a new set position, as described above. As such, the aligner 34 takes a set before the bone 24 has a chance to remodel. It will be appreciated that it may take from between about 20 to about 40 days for the lamina dura to resorb from the trabecular bone side because of the increased vascularity there.
[0032] Once the aligner 34 sets, the load applied by the aligner 34 is significantly reduced as compared to the initial load or the load disappears altogether. As such, no additional appreciable tooth movement may occur after the aligner 34 takes a set. However, the plastically deformed aligner may hold the tooth 22 in a repositioned location while the bone 24 remodels away from the tooth 22 . In this manner, it is thought that aligners made of the above-mentioned materials move teeth, though the movement is limited to a distance related to the thickness of the PDL 30 . Therefore, use of the aligners made of these materials is limited in this regard. It may be concluded that current treatment plans that require an aligner of the above-mentioned polymers to move a tooth greater than is permitted by the thickness of the PDL 30 may be particularly susceptible to a failure and a “reboot,” as described above.
[0033] In view of the above, in one embodiment of the invention, the aligner 10 may be made of a polymer characterized by a modulus of elasticity that, while varying with temperature, maintains a modulus in the oral environment sufficient to move tooth for a time period greater than 24 hours after insertion to an oral environment. By way of example, the aligner 10 may be capable of applying loads sufficient to compress the PDL as the bone remodels over a period of several days. This may be, for example, on or after 20 days from the insertion of the aligner 10 into the oral environment. The aligner 10 according to embodiments of the present invention may thus be capable of moving teeth over a distance that is not limited by the thickness of the PDL.
[0034] Advantageously, according to embodiments of the invention, treatment may proceed at a more rapid pace in that the patient may not be required to have the treatment “rebooted.” Furthermore, fewer aligners in the series may be required, making treatment more cost effective.
[0035] In embodiments of the invention, it is anticipated that the polymer of the aligner may exhibit viscoelastic material properties as has been seen in prior art aligners. However, the polymer may be characterized by relatively high relaxation times compared to the polymers tested above. The relaxation time of a polymer is defined as the time necessary for the stress to fall to 0.37 of the initial stress. The exponential decay of the stress with time is given by σ=σ 0 e −t/τ where σ 0 is the initial stress, t is the time, and τ is the relaxation time. Stress relaxation is an Arrhenius phenomenon, which is described by the equation 1/τ=Ce −Q/RT , where C is a pre-exponential constant, Q is the activation energy for viscous flow, R is the universal gas constant, and T is the absolute temperature.
[0036] By way of example, an aligner, according to the present invention, has an in vitro relaxation time that is at least about double that of the polymers tested above. By way of additional example, the aligner according to one embodiment of the present invention may have an in vitro relaxation time that is an order of magnitude greater than those of the polymers tested above. As such, the aligner may be capable of maintaining at least 37% of the initial load at installation for at least two weeks in the oral environment. It will be appreciated that 37% of the initial stress may be greater than the stress needed to move the tooth, that is, compress the PDL and generate remodeling of bone during this entire timeframe.
[0037] To that end, the aligner may be made of a polymeric material having a glass transition temperature that is equal to or exceeds about 30° C., for example, about 37° C., about 70° C., or about 100° C. By way of alternative example, the aligner may be made of a polymer, such as one or more thermoplastic or thermoset polymers or resins suitable for use in the human mouth. Exemplary polymers may include polyurethanes, ionomers, or polycarbonates. Other exemplary polymers include polysulphone, acrylic, polyamide, acrylonitrile-butadiene-styrene terpolymer, or polyethylene terephthalate. In a further example, the aligner may be at least one of polyoxymethylene, acrylonitrile, styrene acrylonitrile, styrene butadiene rubber, polyetheretherketone, or polyarylethereketone.
[0038] It will be appreciated that the aligner may be made entirely of one or more of the above mentioned polymers. That is, the aligner may be 100% polymer or polymer mixture.
[0039] Alternatively, the aligner may be layered. That is, two or more of the polymers listed above may be layered to reduce degradation of the underlying polymeric layer from direct exposure to the fluid found in the oral environment. In addition, the aligner may include a reinforcing agent, such as, glass particles or fibers or polymeric fibers.
[0040] While the present invention has been illustrated by a description of various embodiments and while these embodiments have been described in some detail, it is not the intention of the inventor to restrict or in any way limit the scope of the appended claims to such detail. Thus, additional advantages and modifications will readily appear to those of ordinary skill in the art. The various features of the invention may be used alone or in any combination depending on the needs and preferences of the user.
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An orthodontic aligner of the type that is deformable from its initial shape to a deformed shape when fitted upon a patient's teeth in order to apply a load to the teeth to move the teeth to an orthodontically preferred position is made from a polymeric material that generates a continuing elastic return stress driving toward the initial shape after a substantial period of continuous deformation, such as longer than one day and up to or exceeding two weeks. Elastic stress loads applied to teeth over such durations cause greater remodeling of the bone adjacent to a tooth's roots than is possible with known aligner materials.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a variable delay line of a distributed constant type, and in particular to an improvement of a variable delay line using a transmission line such as a microstrip line.
2. Description of the Prior Art
Since a transmission line can function as a delay line, it has been known from the past that the delay time may be varied when a variable delay line is formed by using such a transmission line by providing fixed contacts in the electroconductive path of this transmission line at certain intervals and by changing the length of the electroconductive path over which a signal travels through switchover of these fixed contacts.
Such a variable delay line of a distributed constant type has advantages in that the structure is simple and the manufacturing cost may be kept low, and it is capable of varying the delay time of a high speed signal having an extremely fast rise time, for instance less than one nanosecond.
However, in order to increase the incremental resolution of the delay time, a large number of fixed contacts must be formed in the electroconductive path of the transmission line at small intervals. Therefore, when such a variable delay line is to be reduced in size and its incremental resolution is to be increased, it is necessary to form a large number of fixed contacts in the electroconductive path at small intervals, and the formation of the fixed contacts becomes difficult. Therefore, it has been extremely difficult to achieve both reduction in the size of such a variable delay line and also increase in the incremental resolution of said delay time at the same time.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a variable delay line which can easily achieve both reduction in size and also improved incremental resolution of switchover in delay time, making good use of the features of a transmission line as a delay line element.
To achieve this object, the variable delay line of this invention comprises a transmission line comprising an electroconductive path and a ground plate disposed opposingly with a dielectric body interposed therebetween, a fixed contact array consisting of fixed contacts provided at certain intervals along the electroconductive path, and a movable contact which may be slid along contacting said fixed contacts of said fixed contact array; characterized in that said movable contact contents one of said fixed contacts in said fixed contact array in a first state and contacts two neighboring ones of said fixed contacts in said fixed contact array in a second state, and as said movable contact is slid over said fixed contact array its state alternates between said first state and said second state.
In a structure according to the present invention, when the movable contact slides along the fixed contact array in an alternating manner it (a) enters into a single contact with one individual one of the fixed contacts and (b) enters into a double contact with two neighboring ones of the fixed contacts, thereby it becomes possible to increase the incremental resolution of the delay time provided by the transmission line over that obtained in the prior art, when the movable contact only touches at the most one of the fixed contacts at one time. Therefore, because the incremental resolution can be increased according to this invention without any necessity of arranging a large number of fixed contacts along the electroconductive path at small intervals, it becomes possible to drastically reduce the size of the variable delay line and to achieve fine switchover of delay time.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be shown and described with reference to the preferred embodiments thereof, and with reference to the illustrative drawings, which however are given for the purposes of explanation and exemplification only, and are not intended to be limitative of the scope of the present invention in any way. In the drawings:
FIG. 1 is a front partial sectional view showing a preferred embodiment of the variable delay line of this invention;
FIG. 2 is a side partial sectional view of the variable delay line of FIG. 1;
FIGS. 3 and 4 are respectively a plan view and a side view of a delay line element included in the variable delay line of FIG. 1;
FIG. 5 is a perspective view of a holder shown in FIG. 1;
FIG. 6 is an equivalent circuit diagram for the variable delay line of FIG. 1;
FIG. 7 is a view illustrating the action during a single contact situation of the variable delay line of FIG. 1;
FIG. 8 is a view illustrating the action during a double contact situation of the variable delay line of FIG. 1;
FIG. 9 is a set of three wave form diagrams relating to the operation of the variable delay line of FIG. 1; and
FIGS. 10 and 11 are respectively a plan view and a side view, similar to FIGS. 3 and 4 respectively, and showing the delay line element incorporated in another preferred embodiment of the variable delay line of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described with reference to the preferred embodiments thereof, and with reference to the appended drawings. Referring to FIGS. 1 and 2, a case 1 is molded from synthetic resin in the form of an elongated box having an open upper side. A delay line element 5 is fixedly secured to the bottom 3 of the case 1 with its broader face downwards.
As shown in FIGS. 3 and 4, the delay line element 5 has an electroconductive path 11 which is folded round and round in a spiral manner at a pitch P over a dielectric body 9 formed on the outer surfaces and around the edges of an elongated ground plate 7, and part of the ground plate 7 projects from both the longitudinal ends of the dielectric body 9. Therefore, the electroconductive path 11 portion of the delay line element 5 is made to be relatively long, and opposes the surface of the ground plate 7, and is formed generally as a flat body. The delay line element 5 is fixedly secured to the bottom 3 of the case 1 with the broader surfaces of the ground plate 7 facing in the upwards and downwards directions, as shown in FIGS. 1 and 2.
The ground plate 7 of the delay line element 5 fixedly secured inside the case 1 is connected to input and output ground terminals 13, 15 formed in the bottom 3 of the casing 1 and penetrating therethrough. One end of the electroconductive path 11 is connected to an output terminal 17 which is likewise produced in the bottom 3, and the other end of the electroconductive path 11 is connected to the input ground terminal 13 by way of an internal terminal resistor R 0 (not shown in FIGS. 1 and 2).
A support piece 19 projects from the internal surface of the case 1 above the delay line element 5, and the open upper side of the case 1 is closed by an electroconductive plate 21 supported by the support piece 19. The electroconductive plate 21 is press formed and has a depression 23 which extends along the lengthwise direction of the delay line element 5, and the portion of the electroconductive plate 21 which forms the depression 23 is also provided with an elongated slit 25 which extends also along the lengthwise direction of the delay line element 5. The electroconductive plate 21 is connected to an input terminal 27 which is provided extending through the bottom 3 by way of a conductor 27a extending along the internal surface of the case 1.
Between the portion of the electroconductive plate 21 defining the depression 23 and the delay line element 5 is disposed a holder 29 which accomodates a movable contact spring 37 which will be described in detail later. This holder 29 is formed as a frame, and is provided with a partition plate 31 which divides this frame and a projection 33 which projects upwardly from the center of this partition plate 3 as shown in FIG. 5, and, as shown in FIGS. 1 and 2, the projection 33 projects into the depression 23 by way of the slit 25. And by affixing a knob 35 to this projection 33, the holder 29 is movably and slidably supported by the electroconductive plate 21.
The holder 29 accomodates a movable contact spring 37 which is formed by arcuately bending a strip of an electroconductive plate in such a manner that a middle bulging portion 38 thereof is elastically contacting the delay line element 5 and the two ends thereof are elastically contacting the electroconductive plate 21. The pitch P of the electroconductive path 11 in the delay line element 5 and the arcuately bent shape of the movable contact spring 37 are so selected that the middle bulging portion 38 of the movable contact spring 37, when said spring 37 is in certain positions, contacts two neighboring ones of the fixed contacts 39 defined by the upper surfaces of the turns of the spiral winding of the electroconductive path 11 at the same time; this state of affairs is shown in FIG. 1. Therefore, by moving the knob 35, the movable contact spring 37 is well as the holder 29 moves along the lengthwise direction of the delay line element 5 and the movable contact spring 37 moves across the electroconductive paths 11 of the delay line element 5 elastically contacting therewith while maintaining an elastic contact with the electroconductive plate 21. Furthermore, the movable contact spring 37, during its travel, either contacts just one of the fixed contacts 39, or simultaneously contacts two adjacent ones of said fixed contacts 39; and these conditions alternate as the movable contact spring 37 slidingly travels. Thus, for each winding of the delay line element 5, the portion of each electroconductive path 11 located on its upper surface functions as a fixed contact 39, and these fixed contacts 39, which are aligned along the lengthwise direction of the delay line element 5, form a fixed contact array 41.
If the delay line element 5 is formed in such a manner that the electroconductive path 11 is formed in a flat spiral at the pitch P by being alternatingly folded back over a first plane U and a second plane V which is parallel to the first plane U and is located at a distance T therebetween, as shown in FIG. 4, and the pitch P and the inter-plane distance T are selected so that for instance the ratio T/P is between zero and unity, the following advantages may be obtained. Namely, it becomes possible to increase the positive couplings in the electroconductive path 11, and a favorable delay property may be obtained by restricting the reduction in the line length due to the negative couplings in the electroconductive path 11, by employing the positive couplings.
The variable delay line of this invention may be expressed by an equivalent circuit in which a plurality of transmission lines (which will be referred to merely as unit lines 43) each having a delay time t d , a characteristic impedance of R 0 , and having same line lengths, are connected in series, and an internal terminal resistor R 0 is connected to the unit line 43 located at one end thereof, while a load resistor R 0 for taking out an output signal is connected to the unit line 43 located at the other end. And fixed contacts 39 are provided, one at each of the junctions of the unit lines 43, and one at each end at the junctions between the end unit lines 43, and the respective resistors R 0 , thereby defining a fixed contact array 41; and the movable contact spring 37 moves over this fixed contact array 41 alternatingly entering into a single contact situation and a double contact situation. The position of the movable contact spring 37 indicated by broken lines in FIG. 6 shows a single contact situation, while the position of the movable contact spring 37 indicated by solid lines in FIG. 6 shows a double contact situation. Therefore, when a signal is inputted to an arbitrary one of the fixed contacts 41 from the input terminal 27 by way of the electroconductive plate 21, the signal is outputted after a delay time which corresponds to the number of the unit lines 43 located between the input point and the load resistor R 0 .
Now, the working principle of the variable delay line of this invention will be described in the following, with reference to FIGS. 7 and 8. Here, it is assumed that the pulse generator PG in the drawings has an internal impedance of R 0 /2, a rise time of t r , and an electromotive force of e 1 .
First is explained the case in which the movable contact spring 37 is making a single contact with one of the fixed contacts 39 at an intermediate point of the fixed contact array 41. In this case, the pulse generator PG is connected to transmission lines 45, 47, respectively having a delay time t d1 and a delay time t d2 , and both have a characteristic impedance R 0 , which are connected in parallel, as shown in FIG. 7, and each of the transmission lines 45, 47 is terminated by a resistor R 0 , while the output is taken out from the transmission line 45 having the delay time T d1 . Because the two transmission lines 45, 47 are connected in parallel to the input point P 1 of the transmission lines 45, 47, the impedance at the input point P 1 is R 0 /2. The voltage e 2 at the point P 1 is:
e.sub.2 =e.sub.1 /2 . . . (1)
and as shown by the broken line in FIG. 9A, has the same rise time t r as the voltage e 1 , but has an amplitude which is only one half as much. In FIG. 9, only the rise portion is shown, for the convenience of description. Further, a rise time generally means the time interval between 10% and 90% of the amplitude, and the wave form is generally a smooth curve as shown by the dotted line in FIG. 9A near 0% amplitude and 100% amplitude. However, for the convenience of description, it is assumed that the waveform linearly rises in time t r as indicated by the broken line between E and G in FIG. 9A between zero amplitude and 100% amplitude.
And at the output side of the transmission line 45 to which the voltage e 2 is applied, an output voltage which is delayed by time T d1 therefrom may be taken out. Also, at the other transmission line 47, an output voltage having a delay time of T d2 is obtained, and is consumed in the internal terminal resistor R 0 .
Next is explained the state in which the movable contact 37 has moved from the single contact state one step to the left in FIG. 6 to the double contact state (the double contact state shown in FIG. 6 is three steps away from the single contact state shown therein). In this case, as shown in FIG. 8, the transmission line 45 for taking out an output signal has a delay time T d1 which is the same as the single contact state, while the other transmission line 49 has a delay time T d3 which is shorter by the delay time t d belonging to the unit line 43 between two neighboring contacts. In this double contact state, the two ends of the single unit line 43 are short circuited by the movable contact spring 37, and the one ends of the transmission lines 45, 49 and the two ends of the single unit line 43 are connected to the pulse generator PG in parallel.
Since, in the double contact state, a result which is different from that of the single contact state can be obtained when the same pulse signal voltage e 1 as FIG. 7 is applied thereto, due to the relationship between the rise time t r of the pulse generator PG and the delay time t d of the unit line 43, this will be discussed in the following with reference to FIG. 9. In FIG. 9, the solid line indicates a voltage waveform e 3 during the double contact situation.
First is described the case in which t d (the delay time) is greater than t r (the rise time), with reference to FIG. 9A. This relationship is not desirable from a practical viewpoint, but nonetheless this case will be explained as a starting point for the convenience of explanation. Because the input point P 2 to the transmission lines 45, 49 has four lines connected in parallel, the impedance at the input point P 2 is R 0 /4. Therefore, the voltage e 3 at this point P 2 is: ##EQU1## and the ratio of the voltage e 3 during the double contact situation to the voltage e 2 during the single contact situation is:
e.sub.3 /e.sub.2 =2/3≃0.667 . . . (3)
Therefore, the voltage e 3 rises in the same rise time t r as the first rise (E-J of FIG. 9A) up to 66.7% amplitude of the voltage e 2 . And with respect to the unit line 43 whose two ends are connected to the input point P 2 , the first rise signal propagates from the two ends towards the other ends at the same time, and reaches the two ends after the time t d .
This unit line 43 is equivalent to a circuit in which a signal transmission line having a characteristic impedance of R 0 /2 and a delay time of td/2 is connected with its other end kept open, and the signal reflected at the open end returns to the input point P 2 after a two way travel time of t d . Analysis is simplified in this way. Part of the returned signal is added to the voltage e 3 at the input point P 2 , and becomes the second rise indicated by K-L in FIG. 9A, and a part thereof is again reflected back to the open end.
In regards to this second rise, assuming that the degeneration of the signal propagating through the unit line 43 is negligible because the length of the unit line 43 is short, the reflection coefficient ρ as seen from the unit line 43 to the input point P 2 is: ##EQU2## Therefore, from equations (2) and (4), the following equation:
e.sub.3 =e.sub.1 /3+(e.sub.1 /3)(1+ρ)=5/9 e.sub.1 (5)
holds, and therefore:
e.sub.3 /e.sub.2 =10/9≃1.111 (6)
holds. Therefore, in FIG. 9A, the second rise begins after the time t d from the start point E of the first rise, and reaches 111.1% of the voltage e 2 after the time t r as indicated by K-L.
Thereafter, in the unit line 43 of t d /2, the signal repeats the reciprocating reflection, and affects the voltage e 3 according to the reflection coefficient ρ, which is -166 as per equation (4). Therefore, after the time t d from the beginning point K of the second rise, the signal drops to 96.3% of the amplitude in the time t r as indicated by M-N of FIG. 9A. Although it is not so shown in the drawings, the wave form alternately repeats a rise and decline for each time interval t d to 101.2% amplitude, 99.6% amplitude, and so on, thus converging to 100% amplitude.
As a result, as shown by FIG. 9A, the voltage e 3 is delayed by ΔT dm with respect to the voltage e 2 , during the interval F-H which is the 50% amplitude of the voltage e 3 . This ΔT dm may be expressed by equation (7) from the proportionally calculation, based upon similar triangles:
ΔT.sub.dm =0.25tr (7)
Thus, under the condition that t d (the delay time) is greater than t r (the rise time), the wave form at the input point P 2 during the double contact situation is an irregular wave form having the first and second rises. However, as compared to the single contact situation, there arises the delay time ΔT dm , which is 0.25t r delay at the 50% amplitude, the delay time of T d1 plus ΔT dm arises also at the output end of the transmission line 45, and the delay time is increased by ΔT dm over the single contact.
Next is explained the case in which t d (the delay time) equals t r (the rise time), with reference to FIG. 9B. In this case, the wave form is J-K, L-M, and so on, in FIG. 9A, minus the horizontal portions. Therefore, the first rise, the second rise, and so on are connected continuously. Because in this case also the voltage e 3 involves the delay time of ΔT dm equal to 0.25t r , during the interval F-H of the 50% amplitude relative to the voltage e 2 , in the same way as in equation (7), the output end of the transmission line 45 involves the delay time of T d1 plus ΔTdm, thus resulting in a delay time which is ΔT dm greater than the single contact state. And this case is also not a desirable condition.
Now will be described the case in which t d (the delay time) is smaller than t r (the rise time), with reference to FIG. 9C. In this case, the start point K of the second rise precedes the end point J of the first rise, and the signal rises from the start point E of the first rise to the point J initially. However, after the time t d therefrom, a signal which forms the second rise is produced from the two ends of the unit line 43, and is added to the first rise and therefore the slope of the rise in increased, so that the signal rises from the point K to the point J'. However, the interval K-J' is not necessarily a straight line, and the increase and the decrease in the slope are repeated for each time interval t d , over K-L-N-P--J', and finally the degrees of the increase and the decrease of the slope diminishes and the magnitude of the slopes ultimately converges to the same value as that of the rise of the voltage e 2 in the single contact state, or the slope of the interval E-G indicated by a broken line in FIG. 9C. The magnitudes of the increase and the decrease of the slope can be easily obtained by sequentially adding the values of the output of the reflected signals, based upon the reflection coefficient of equation (4). After the point J', the slope becomes smaller because of the completion of the first rise portion, but the signal reaches the point S, which is approximately the 100% amplitude, after the time t r from the beginning point K of the second rise. In this case, the voltage e 3 involves the delay time ΔT d as follows:
T.sub.d ≃0.25t.sub.d (8)
with respect to the voltage e 2 over the interval F-H of 50% amplitude.
In other words, in the cases in which t d (the delay time) is greater than t r (the rise time), and td (the delay time) is equal to t r (the rise time), as shown in FIGS. 9A and 9B, the delay time ΔT dm between the voltage e 2 and the voltage e 3 is dependent only on the rise time t r of the input signal e 1 , and is not dependent on the delay time t d of the unit line 43. However, in the case in which t d (the delay time) is smaller than t r (the rise time), or, to be accurate, t d is equal to or smaller than 0.75t r , the delay time ΔT d between the voltage e 2 and the voltage e 3 is dependent on the delay time t d of the unit line 43. And when the delay time t d is relatively near 0.75t r , the delay time ΔT d varies over the range of 0.22t d to 0.33t d , according to the ratio of the delay time t d to the rise time t r , but as the delay time td becomes smaller as compared to the rise time t r the delay time ΔT d becomes more and more constant at 0.25t d .
Therefore, in this case, with reference to FIG. 6, as the movable contact spring 37 is moved to the left step by step from the rightmost position repeating the single contact situation and the double contact alternately, the delay time obtained at the output end changes from zero through 0.25t d , t d , 1.25t d , 2t d , 2.25t d , and so on. In other words, it is possible to have an incremental resolution of delay time width which is finer than the delay time t d , with the delay time t d of the unit line 43 used as a unit. On the other hand, when t d is greater than 0.75t r , the delay time ΔT dm between the voltage e 2 and the voltage e 3 is determined by 0.25t r or the rise time t r alone, and is not dependent on the delay time t d . Therefore, the greater the delay time t d becomes, as compared to the rise time t r , the smaller the delay time difference between the single contact state and the double contact state becomes, and the effect of increasing the incremental resolution diminishes. Additionally, the waveform becomes irregular as shown in FIGS. 9A and 9B.
However, when a variable delay line is to be used in reality, it is rare to have the cases shown in FIGS. 9A and 9B, and in most cases the actual situation is as shown in FIG. 9C. For instance, the highest speed type ECL (a type of super high speed logic circuit IC) has a rise time t r of output signal of 700 ps or so (this is the interval between 20%-80% of the final amplitude). As a variable delay line which is suited for adjusting the delay time of this output signal, forty unit lines 43 each having the delay time t d of 50 ps can be used with a total variable range of delay time of 2 ns. In this case, the delay time t d becomes 0.0714tr, and it can satisfy the above mentioned necessity with a margin of one order or more. If this condition is not satisfied and an unexpected high speed pulse signal is applied, a filter circuit may be inserted between the input terminal 27 and the electroconductive plate 21 for slowing down the rise of the input signal, and the filter function may be provided by the electroconductive plate 21, the movable contact spring 37, and so on.
In the above analysis, it has been assumed for the requirements of explanation that the delay time is the same for all the unit lines 43, but if these delay times are increased gradually in this invention an advantage may be obtained in that the delay time Δt d may be likewise increased, if it remains within the range in which equation (8) applies.
The variable delay line of this invention described above may not necessarily use a delay line element 5 which is formed by spirally bending back an electroconductive path 11 as shown in FIG. 3, but may also use a delay line element 6 as shown in FIGS. 10, and 11 and 12.
Specifically, an electroconductive path 11 is wound over a dielectric body 9 formed on a ground plate 7 by spiral winding in a first direction for a few turns, and the electroconductive path 11 is then wound in the opposite direction over the succeeding few turns, and further the direction of the winding is then reversed every few turns. In other words, the delay line element 6 is formed by changing the winding direction of the electroconductive path 11 alternatingly each few turns as it is wound along the lengthwise direction X--X of the ground plate 7. When such a delay line element 6 is used, because a new negative coupling arises at each change of the direction of the winding of the electroconductive path 11, the positive couplings increased by winding the electroconductive path 11 may be controlled by these negative couplings. Therefore, even if the delay line element 5 shown in FIG. 3 is reduced in size and its positive couplings are made more strong than is required or desirable, it is possible to restrain the positive couplings and to obtain a favorable property.
This invention is not limited to the above described delay line elements, but may be implemented by using a transmission line consisting of a coaxial cable, a transmission line which is made by forming an electroconductive path on one surface of a ground plate by way of a dielectric body, or a transmission line. Thus, although the present invention has been shown and described with reference to certain preferred embodiments thereof, and in terms of the illustrative drawings, nevertheless its scope is to be defined only by the appended claims, since various possible modifications, omissions, and alterations can be conceived of by one skilled in the art to the form and the content of any particular embodiment, without departing from the scope of the present invention.
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This variable delay line makes use of a transmission line as a delay line element and is suitable for switching over the delay time of a high speed signal having for instance a rise time of one nanosecond or less. And this variable delay line includes a transmission line which includes an electroconductive path and a ground plate disposed opposingly with a dielectric body interposed therebetween, a fixed contact array consisting of fixed contacts provided at certain intervals along the electroconductive path, and a movable contact which may be slid along contacting the fixed contacts of the fixed contact array. Particularly, the movable contact contacts one of the fixed contacts in the fixed contact array in a first state and contacts two neighboring ones of the fixed contacts in the fixed contact array in a second state, and the movable contact may be slid over the fixed contact array by alternatingly repeating the first and the second states.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part application of PCT Application Serial No. PCT/EP96/03023 (U.S. Ser. No. 08/981,966), filed Jul. 11, 1996.
FIELD AND BACKGROUND OF THE INVENTION
This invention relates to a series of tetracyclic derivatives, processes for their preparation, pharmaceutical compositions containing them, and their use as therapeutic agents. In particular, the invention relates to tetracyclic derivatives which are potent and selective inhibitors of cyclic guanosine 3',5'-monophosphate specific phosphodiesterase (cGMP-specific PDE) having utility in a variety of therapeutic areas where such inhibition is thought to be beneficial, including the treatment of cardiovascular disorders and erectile dysfunction.
SUMMARY OF THE INVENTION
The present invention provides compounds of formula (I) ##STR2## and pharmaceutically acceptable salts and solvates (e.g., hydrates) thereof, in which:
R 0 represents hydrogen, halogen, or C 1-6 alkyl;
R 1 is selected from the group consisting of:
(a) hydrogen,
(b) C 1-6 alkyl, optionally substituted with one or more substituents selected from phenyl, halogen, --CO 2 R a and --NR a R b ,
(c) C 3-6 cycloalkyl,
(d) phenyl, and
(e) a 5- or 6-membered heterocyclic ring containing at least one heteroatom selected from oxygen, nitrogen and sulphur, and being optionally substituted with one or more C 1-6 alkyl, and optionally linked to the nitrogen atom to which R 1 is attached via C 1-6 alkyl;
R 2 is selected from the group consisting of:
(f) C 3-6 cycloalkyl,
(g) phenyl, optionally substituted with one or more substituents selected from --OR a , --NR a R b , halogen, hydroxy, trifluoromethyl, cyano, and nitro,
(h) a 5- or 6-membered heterocyclic ring containing at least one heteroatom selected from oxygen, nitrogen and sulphur; and
(i) a bicyclic ring ##STR3## attached to the rest of the molecule via one of the benzene ring carbon atoms, wherein A is a 5- or 6-membered heterocyclic ring as defined in (h); and
R a and R b , independently, represent hydrogen or C 1-6 alkyl.
The term "C 1-6 alkyl" as used herein denotes any straight or branched alkyl chain containing 1 to 6 carbon atoms, and includes methyl, ethyl, n-propyl, iso-propyl, n-butyl, pentyl, hexyl, and the like.
The term "halogen" as used herein denotes fluorine, chlorine, bromine, and iodine.
A particular group of compounds according to formula (I) are those wherein R 0 represents any of hydrogen, methyl, bromine, and fluorine, but the definition of R 0 given in formula (I) includes within its scope other C 1-6 -alkyl and halogen groups.
R 1 can represent a substituent selected from methyl, ethyl (optionally substituted by one or more chlorine atoms), butyl, cyclohexyl and benzyl. Other R 1 substituents include hydrogen; cycloalkyl groups, such as cyclopropyl; C 1-6 alkyl, typically ethyl or propyl, substituted by an --NR a R b substituent, such as a dimethylamino substituent; phenyl optionally linked to the nitrogen atom to which R 1 is attached via a C 1-6 alkyl chain, such as ethyl or the like; and C 1-6 alkyl, e.g., methyl, substituted by --CO 2 R a , such as --CH 2 CO 2 Et (Et is CH 2 CH 3 ) and the like.
Suitable heterocyclic rings within the definition of R 1 include pyridyl, morpholinyl, piperazinyl, pyrrolidinyl, and piperidinyl. Generally, such heterocyclic rings are linked to the nitrogen atom to which R 1 is attached via a C 1-6 alkyl chain, more appropriately a C 1-4 alkyl chain.
A particular substituent represented by R 2 is ##STR4## Other R 2 substituents include thienyl, pyridyl, furyl, and phenyl, wherein phenyl can be substituted with one or more substituents selected from --OR a (e.g., methoxy), --NR a R b (e.g., dimethylamino), halogen (in particular chlorine or fluorine), hydroxy, trifluoromethyl, cyano, and nitro. Alternatively, R 2 can represent a C 3-6 cycloalkyl group, such as cyclohexyl or the like.
The pharmaceutically acceptable salts of the compounds of formula (I) that contain a basic center are acid addition salts formed with pharmaceutically acceptable acids. Examples include the hydrochloride, hydrobromide, sulfate or bisulfate, phosphate or hydrogen phosphate, acetate, benzoate, succinate, fumarate, maleate, lactate, citrate, tartrate, gluconate, methanesulphonate, benzenesulphonate, and p-toluenesulphonate salts. Compounds of formula (I) also can provide pharmaceutically acceptable metal salts, in particular alkali metal salts, with bases. Examples include the sodium and potassium salts.
It is to be understood that the present invention covers all appropriate combinations of particular and preferred groupings hereinabove.
Particular individual compounds of the invention include:
Cis-2-benzyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-benzyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-5-(4-methoxyphenyl)-2-methyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-ethyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-ethyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-ethyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-ethyl-5-(2-thienyl)-5,6,11,11a-tetrahydro-1H-imidazo-[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-5-(4-dimethylaminophenyl)-2-ethyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-9-methyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-9-bromo-2-butyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-butyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-butyl-9-fluoro-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-9-fluoro-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-butyl-5-(3-chlorophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-(3-chlorophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-butyl-5-(4-chlorophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-(4-chlorophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-(4-fluorophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-(4-hydroxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1', 5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-butyl-5-(4-trifluoromethylphenyl)-5,6,11,11a-tetrahydro-1H-imidazo-[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-butyl-5-(4-cyanophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-(4-cyanophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-butyl-5-(4-nitrophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-(4-nitrophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-butyl-5-(3-pyridyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-butyl-5-(3-thienyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-(3-thienyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-butyl-5-(3-furyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-(3-furyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-cyclohexyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-cyclohexyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-cyclohexyl-9-fluoro-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-cyclohexyl-9-fluoro-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-benzyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-benzyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-benzyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1', 5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
(5R,11aR)-2-benzyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-benzyl-5-(4-hydroxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-(2-chloroethyl)-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-benzyl-5-cyclohexyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-benzyl-5-cyclohexyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-cyclohexyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-cyclohexyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-ethoxycarbonylmethyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-5-(4-methoxyphenyl)-2-[2-(2-pyridyl)-ethyl]5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-cyclopropyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-phenethyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-5-phenyl-2-(2-pyridylmethyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-5-phenyl-2-(4-pyridylmethyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-5-(4-methoxyphenyl)-2-(3-pyridylmethyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-(2-dimethylaminoethyl)-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-(3-dimethylaminopropyl)-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-(2-morpholin-4-yl-ethyl)-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-5-(4-methoxyphenyl)-2-[3-(4-methyl-piperazin-1-yl)-propyl]-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-5-(4-methoxyphenyl)-2-(2-pyrrolidin-1-yl-ethyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-5-(4-methoxyphenyl)-2-[2-(1-methyl-pyrrolidin-2-yl)-ethyl]-5,6,11,11a-tetrahydro-1H-imidazo-[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
and pharmaceutically acceptable salts and solvates thereof.
Particularly preferred compounds of the invention are:
(5R,11aR)-2-benzyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-cyclohexyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Trans-2-butyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrohydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
Cis-2-benzyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione;
and pharmaceutically acceptable salts and solvates thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It has been shown that compounds of the present invention are potent and selective inhibitors of cGMP-specific PDEs 1, 5, and 6, and particularly PDE5. Thus, compounds of formula (I) are of interest for use in therapy, specifically for the treatment of a variety of conditions where inhibition of cGMP-specific PDE is thought to be beneficial.
In summary, the biochemical, physiological, and clinical effects of PDE5 inhibitors suggest their utility in a variety of disease states in which modulation of smooth muscle, renal, hemostatic, inflammatory, and/or endocrine function is desirable. The compounds of formula (I), therefore, have utility in the treatment of a number of disorders, including stable, unstable, and variant (Prinzmetal) angina, hypertension, pulmonary hypertension, congestive heart failure, acute respiratory distress syndrome, acute and chronic renal failure, atherosclerosis, conditions of reduced blood vessel patency (e.g., postpercutaneous transluminal coronary or carotid angioplasty, or post-bypass surgery graft stenosis), peripheral vascular disease, vascular disorders, such as Raynaud's disease, thrombocythemia, inflammatory diseases, stroke, bronchitis, chronic asthma, allergic asthma, allergic rhinitis, glaucoma, osteoporosis, preterm labor, benign prostatic hypertrophy, male and female erectile dysfunction, and diseases characterized by disorders of gut motility (e.g., irritable bowel syndrome or IBS).
An especially important use is the treatment of male erectile dysfunction, which is one form of impotence and is a common medical problem. Impotence can be defined as a lack of power, in the male, to copulate and can involve an inability to achieve penile erection or ejaculation, or both. The incidence of erectile dysfunction increases with age, with about 50% of men over the age of 40 suffering from some degree of erectile dysfunction.
Many compounds have been investigated for their therapeutic potential in the treatment of MED, including phenoxybenzamine, papaverine, prostaglandin E1 (PGE1), and phentolamine. These compounds, either alone or in combination, are typically self-administered by intracavernosal (i.c.) injection. While such treatments are effective, a treatment that is less invasive than injection therapy is preferred because pain, priapism, and fibrosis of the penis are associated with the i.c. administration of these agents.
For example, alprostadil (i.e., prostaglandin E1) delivered by intraurethral deposition has been approved for the treatment of MED. However, clinical studies showed that this route of administration is not effective in all patients. In addition, phentolamine and apomorphine are being evaluated as oral and sublingual therapies for MED, but neither compound has demonstrated efficacy across a broad range of subjects. Potassium channel openers (KCO) and vasoactive intestinal polypeptide (VIP) also have been shown to be active i.c., but cost and stability issues could limit development of the latter. An alternative to the i.c. route is the use of glyceryl trinitrate (GTN) patches applied to the penis, which has been shown to be effective but produces side effects in both patient and partner.
As an alternative to pharmacological treatment, a variety of penile prostheses have been used to assist achievement of an erection. The short-term success rate is good, but problems with infection and ischemia, especially in diabetic men, make this type of treatment a final option rather than a first-line therapy.
Because of the disadvantages of prior treatments for MED, new strategies to improve erectile response that exploit different physiological mechanisms are being investigated. One area of investigation is increasing the intracellular concentration of cGMP by providing a new type of oral therapy for the treatment of MED.
Increasing cGMP concentration is an important step in the physiology of penile erections. A penile erection is caused by neural stimuli that ultimately cause vasodilation of the arteries and sinusoidal spaces of the corpus cavernosum. Research indicates that nitric oxide plays a central role in this vasodilation.
In particular, atrial natriuretic peptides (ANP) and nitric oxide (NO, sometimes referred to as endothelium-derived relaxing factor or EDRF) relax smooth muscle by increasing guanylyl cyclase activity, which raises intracellular cGMP concentration. Intracellular cGMP is hydrolyzed by phosphodiesterases (PDEs), thereby terminating the action of the cyclic nucleotide. PDE5 is the major cGMP hydrolyzing enzyme in vascular smooth muscle. Accordingly, PDE5 inhibition potentiates the relaxant effects of ANP and nitric oxide by increasing the cGMP levels. Therefore, a compound that inhibits the PDE5 enzyme (and thereby indirectly inhibits the hydrolysis of cGMP) should potentiate the vascular response to nitric oxide, thereby facilitating the achievement and maintenance of erection.
PDE5 inhibitors have potential for use in treating male erectile dysfunction (MED), hypertension, heart failure, and other disease states because of their ability to facilitate the action of ANP and NO. For example, sildenafil, a PDE inhibitor showing little selectivity with respect to PDE6, has the structure: ##STR5## and has shown efficacy in oral administration clinical trials for MED, which supports the hypothesis that augmenting normal or subnormal guanylyl cyclase stimuli has therapeutic benefits.
It is envisioned, therefore, that compounds of formula (I) are useful in the treatment of erectile dysfunction. Furthermore, the compounds can be administered orally, thereby obviating the disadvantages associated with intracavernosal administration. Thus, the present invention concerns the use of compounds of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition containing either entity, for the manufacture of a medicament for the curative or prophylactic treatment of erectile dysfunction in a male animal, including man.
It also has been observed that human corpus cavernosum contains three distinct PDE enzymes (see A. Taher et al., J. Urol., 149, p. 285A (1993)), one of which is the cGMP-specific PDE5. As a consequence of the selective PDE5 inhibition exhibited by compounds of the present invention, the present compounds sustain cGMP levels, which in turn mediate relaxation of the corpus cavernosum tissue and consequent penile erection.
Although the compounds of the invention are envisioned primarily for the treatment of erectile dysfunction in humans, such as male erectile dysfunction and female sexual dysfunction, including orgasmic dysfunction related to clitoral disturbances, they also can be used for the treatment of premature labor and dysmenorrhea.
It is understood that references herein to treatment extend to prophylaxis, as well as treatment of established conditions.
It also is understood that "a compound of formula (I)," or a physiologically acceptable salt or solvate thereof, can be administered as the neat compound, or as a pharmaceutical composition containing either entity.
A further aspect of the present invention is providing a compound of formula (I) for use in the treatment of stable, unstable, and variant (Prinzmetal) angina, hypertension, pulmonary hypertension, chronic obstructive pulmonary disease, congestive heart failure, acute respiratory distress syndrome, acute and chronic renal failure, atherosclerosis, conditions of reduced blood vessel patency (e.g., post-PTCA or post-bypass graft stenosis), peripheral vascular disease, vascular disorders such as Raynaud's disease, thrombocythemia, inflammatory diseases, prophylaxis of myocardial infarction, prophylaxis of stroke, stroke, bronchitis, chronic asthma, allergic asthma, allergic rhinitis, glaucoma, osteoporosis, preterm labor, benign prostatic hypertrophy, male and female erectile dysfunction, or diseases characterized by disorders of gut motility (e.g., IBS).
According to another aspect of the present invention, there is provided the use of a compound of formula (I) for the manufacture of a medicament for the treatment of the above-noted conditions and disorders.
In a further aspect, the present invention provides a method of treating the above-noted conditions and disorders in a human or nonhuman animal body which comprises administering to said body a therapeutically effective amount of a compound of formula (I).
Compounds of the invention can be administered by any suitable route, for example by oral, buccal, inhalation, sublingual, rectal, vaginal, transurethral, nasal, topical, percutaneous, i.e., transdermal, or parenteral (including intravenous, intramuscular, subcutaneous, and intracoronary) administration. Parenteral administration can be accomplished using a needle and syringe, or using a high pressure technique, like POWDERJECT™. Oral administration generally is preferred.
With respect to treating sexual dysfunction and particularly erectile dysfunction in humans, oral administration of the compounds of the invention is the preferred route. Oral administration is the most convenient and avoids the disadvantages associated with intracavernosal administration. For patients suffering from a swallowing disorder or from impairment of drug absorption after oral administration, the drug can be administered parenterally, e.g., sublingually or buccally.
For administration to man in the curative or prophylactic treatment of the conditions and disorders identified above, oral dosages of a compound of formula (I) generally are about 0.5 to about 1000 mg daily for an average adult patient (70 kg). Thus, for a typical adult patient, individual tablets or capsules contain 0.2 to 500 mg of active compound, in a suitable pharmaceutically acceptable vehicle or carrier, for administration in single or multiple doses, once or several times per day. Dosages for intravenous, buccal, or sublingual administration typically are 0.1 to 500 mg per single dose as required. In practice, the physician determines the actual dosing regimen which is most suitable for an individual patient, and the dosage varies with the age, weight, and response of the particular patient. The above dosages are exemplary of the average case, but there can be individual instances in which higher or lower dosages are merited, and such are within the scope of this invention.
For human use, a compound of the formula (I) can be administered alone, but generally is administered in admixture with a pharmaceutical carrier selected with regard to the intended route of administration and standard pharmaceutical practice. For example, the compound can be administered orally, buccally, or sublingually in the form of tablets containing excipients such as starch or lactose, or in capsules or ovules, either alone or in admixture with excipients, or in the form of elixirs or suspensions containing flavoring or coloring agents. Such liquid preparations can be prepared with pharmaceutically acceptable additives, such as suspending agents (e.g., methylcellulose, a semisynthetic glyceride such as witepsol, or mixtures of glycerides such as a mixture of apricot kernel oil and PEG-6 esters, or mixtures of PEG-8 and caprylic/capric glycerides). A compound also can be injected parenterally, for example, intravenously, intramuscularly, subcutaneously, or intracoronarily. For parenteral administration, the compound is best used in the form of a sterile aqueous solution which can contain other substances, for example, salts, or monosaccharides, such as mannitol or glucose, to make the solution isotonic with blood.
For veterinary use, a compound of formula (I) or a nontoxic salt thereof, is administered as a suitably acceptable formulation in accordance with normal veterinary practice. The veterinarian can readily determine the dosing regimen and route of administration that is most appropriate for a particular animal.
Thus, the invention provides in a further aspect a pharmaceutical composition comprising a compound of the formula (I), together with a pharmaceutically acceptable diluent or carrier therefor.
There is further provided by the present invention a process of preparing a pharmaceutical composition comprising a compound of formula (I), which process comprises mixing a compound of formula (I), together with a pharmaceutically acceptable diluent or carrier therefor.
In a particular embodiment, the invention includes a pharmaceutical composition for the curative or prophylactic treatment of erectile dysfunction in a male animal, including man, comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof, together with a pharmaceutically acceptable diluent or carrier.
A compound of formula (I) also can be used in combination with other therapeutic agents which can be useful in the treatment of the above-mentioned and other disease states. The invention thus provides, in another aspect, a combination of a compound of formula (I), together with a second therapeutically active agent.
A compound of formula (I) can be used in the preparation of a medicament for co-administration with the second therapeutically active agent in treatment of conditions where inhibition of a cGMP-specific PDE is beneficial. In addition, a compound of formula (I) can be used in the preparation of a medicament for use as adjunctive therapy with a second therapeutically active compound to treat such conditions. Appropriate doses of known second therapeutic agents for use in combination with a compound of formula (I) are readily appreciated by those skilled in the art.
In particular, because compounds of the present invention maintain cGMP levels, the compounds of formula (I) can provide beneficial antiplatelet, antineutrophil, antivasospastic, vasodilatory, natriuretic, and diuretic activities, as well as potentiate the effects of endothelium-derived relaxing factor (EDRF), gastric NO administration, nitrovasodilators, atrial natriuretic factor (ANF), brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), and endothelium-dependent relaxing agents such as bradykinin, acetylcholine, and 5-HT 1 .
The present selective PDE5 inhibitors in combination with vasodilators, including nitric oxide and nitric oxide donators and precursors, such as the organic nitrate vasodilators which act by releasing nitric oxide in vivo, are especially useful in treatment of angina, congestive heart failure, and malignant hypertension (e.g., pheochromocytoma). Related to the capacity of the present PDE5 inhibitors to potentiate nitric oxide donors and precursors is their ability, in spontaneously hypertensive rats, to reverse the desensitization to these agents that occurs with chronic use.
Examples of vasodilators that can be used in conjunction with the compounds of formula (I) include, but are not limited to, (a) organic nitrates, such as nitroglycerin, isosorbide dinitrate, pentaerythrityl tetranitrate, isosorbide-5-mononitrate, propatyl nitrate, trolnitrate, nicroandil, mannitol hexanitrate, inositol hexanitrate, N-[3-nitratopivaloyl]-L-cysteine ethyl ester, (b) organic nitrites, like isoamyl nitrite, (c) thionitrites, (d) thionitrates, (e) S-nitrosothiols, like S-nitroso-N-acetyl-D,L-penicillamine, (f) nitrosoproteins, (g) substituted furoxanes, such as 1,2,5-oxadiazole-2-oxide and furazan-N-oxide, (h) substituted sydnonimines, such as molsidomine and mesocarb, (i) nitrosyl complex compounds, like iron nitrosyl compounds, especially sodium nitroprusside, and (j) nitric oxide (NO) itself.
Other classes of therapeutic agents that can be used in conjunction with the compounds of formula (I), in addition to vasodilators, include, but are not limited to, α-adrenergic blockers, mixed α,β-blockers, prostaglandin EI (PGEI) and prostacyclin (PGI2), angiotensin converting enzyme inhibitors (ACE inhibitors), neutral endopeptidase (NEP) inhibitors, centrally acting dopaminergic agents (such as apomorphine), vasoactive intestinal peptides (VIP), calcium channel blockers, and compounds like thiazides.
Alpha-adrenergic blockers inhibit vasoconstriction in the corpus cavernosum. Because PDE5 inhibitors enhance vasodilation of the same smooth muscle tissue, a PDE5 inhibitor of formula (I) and an α-adrenergic blocker, like phentolamine or prazocin, or a centrally acting dopaminergic agent, like apomorphine, can be expected to potentiate one another in a treatment for MED or other disorders. Potentiation of mixed α,β-blockers, like carvedilol, which is employed in treatment of hypertension, also is expected. Similarly, α 2 -adrenergic blockers, like yohimbine, can be potentiated.
Prostaglandin E1 enhances relaxation of the corpus cavernosum by increasing the formation of cyclic AMP. Cyclic AMP can be degraded in the corpus cavernosum by PDE3, which is inhibited by cyclic GMP. By maintaining cyclic GMP levels, a PDE5 inhibitor can indirectly inhibit PDE3 activity, and hence block degradation of cyclic AMP. Therefore, a PDE5 inhibitor of formula (I) can be expected to potentiate the activity of PGE1 in the treatment of MED or compounds having similar activities, such as PGI2, in the treatment of pulmonary hypertension, for example.
Angiotensin converting enzyme (ACE) inhibitors block the conversion of angiotensin I into angiotensin II, which causes systemic vasoconstriction and the retention of sodium and water. PDE5 inhibitors cause vasodilation in hypertensive animals, and stimulate the excretion of sodium and water in normotensive animals. Therefore, a PDE5 inhibitor of formula (I) can be combined with an ACE inhibitor to achieve more powerful vasodilatory and natriuretic effects in, for example, treatment of congestive heart failure or hypertensive states.
Neutral endopeptidase (NEP) inhibitors inhibit the degradation of atrial natriuretic peptide (ANP) by NEP. PDE5 inhibitors can be expected to potentiate the action of ANP by inhibiting degradation of its second messenger, cyclic GMP, and, therefore, a compound of formula (I) can potentiate the effects of agents, like NEP inhibitors, that increase blood levels of ANP.
The combination referred to above can be presented for use in the form of a single pharmaceutical formulation, and, thus, pharmaceutical compositions comprising a combination as defined above together with a pharmaceutically acceptable diluent or carrier comprise a further aspect of the invention.
The individual components of such a combination, therefore, can be administered either sequentially or simultaneously from the same or separate pharmaceutical formulations. As is the case for the PDE5 inhibitors of formula (I), a second therapeutic agent can be administered by any suitable route, for example, by oral, buccal, inhalation, sublingual, rectal, vaginal, transurethral, nasal, topical, percutaneous (i.e., transdermal), or parenteral (including intravenous, intramuscular, subcutaneous, and intracoronary) administration.
In some embodiments, the compound of formula (I) and the second therapeutic agent are administered by the same route, either from the same or from different pharmaceutical compositions. However, in other embodiments, using the same route of administration for the compound of formula (I) and the second therapeutic agent either is impossible or is not preferred. For example, if the second therapeutic agent is nitric oxide, which typically is administered by inhalation, the compound of formula (I) must be administered by a different route. Furthermore, if a compound of formula (I) is used in combination with a nitrate vasodilator, for example, in treatment of an erectile dysfunction, it is preferred that the compound of formula (I) is administered orally and the vasodilator is administered topically, and preferably in a manner which avoids substantial systemic delivery of the nitrate.
The combination of a compound of formula (I) and a second therapeutic agent is envisioned in the treatment of several disease states. Examples of such treatments are the systemic and topical treatment of male and female sexual dysfunction, wherein a compound of formula (I) is used in combination with phentolamine, prazocin, apomorphine, PDE1, or a vasoactive intestinal peptide. The compound of formula (I) can be administered orally or transuretherally, and the second therapeutic agent can be administered orally, topically, or intracavernosally, for example. Persons skilled in the art are aware of the best modes of administration for each therapeutic agent, either alone or in a combination.
Other disease states that can be treated by a combination of a compound of formula (I) and a second therapeutic agent include, but are not limited to:
(a) treatment of hypertension using a compound of formula (I) in combination with an α-adrenergic blocker, a mixed α,β-blocker, like carvedilol, a thiazide, sodium nitroprusside, an ACE inhibitor, or a calcium channel blocker;
(b) treatment of pulmonary hypertension using a compound of formula (I) in combination with inhaled NO on other inhaled vasodilators, or with PGI2 administered via an IV pump; and
(c) treatment of chronic obstructive pulmonary disease using a compound of formula (I) in combination with inhaled NO.
Compounds of formula (I) can be prepared by any suitable method known in the art or by the following processes which form part of the present invention. In the methods below R 0 , R 1 , and R 2 are as defined in formula (I) above unless otherwise indicated.
Thus, a process (A) for preparing a compound of formula (I) comprises reacting a compound of formula (II) ##STR6## with an isocyanate of formula R 1 --N═C═O, in the presence of a suitable organic solvent, such as a ketone solvent, e.g., butanone, acetone, or the like, and under reflux for several hours, e.g., 14 to 16 hours. Alk as used herein represents a C 1-6 alkyl group, e.g., methyl.
Compounds of formula (I) can be prepared as individual enantiomers in two steps from the appropriate enantiomer of formula (III) or as mixtures (e.g., racemates) of either pairs of cis or trans isomers from the corresponding mixtures of either pairs of cis or trans isomers of formula (III).
Individual enantiomers of the compounds of the invention can be prepared from racemates by resolution using methods known in the art for the separation of racemic mixtures into their constituent enantiomers, for example using HPLC (high performance liquid chromatography) on a chiral column such as Hypersil naphthylurea.
A compound of formula (II) can be prepared from a tryptophan derivative, such as an alkyl ester thereof of formula (III) ##STR7## (where Alk is as previously defined) or a salt thereof (e.g., the hydrochloride salt) according to either of the following procedures (a) and (b). Procedure (b) is only suitable for preparing cis isomers of formula (III) and can be particularly suitable for preparing individual cis enantiomers of formula (III) from D- or L-tryptophan alkyl esters as appropriate.
Procedure (a)
This comprises a Pictet-Spengler cyclization between a compound of formula (III) and an aldehyde R 2 CHO. The reaction can be conveniently effected in a suitable solvent such as a halogenated hydrocarbon (e.g., dichloromethane) or an aromatic hydrocarbon (e.g., toluene) in the presence of an acid such as trifluoroacetic acid. The reaction can be conveniently carried out at a temperature of from -20° C. to reflux to provide a compound of formula (II) in one step. The reaction also can be carried out in a solvent such as an aromatic hydrocarbon (e.g., benzene or toluene) under reflux, optionally using a Dean-Stark apparatus to trap the water produced.
The reaction provides a mixture of cis and trans isomers which can be either individual enantiomers or racemates of pairs of cis or trans isomers depending upon whether racemic or enantiomerically pure tryptophan alkyl ester was used as the starting material. Individual cis or trans enantiomers can be conveniently separated from mixtures thereof by fractional crystallization or by chromatography (e.g., flash column chromatography) using appropriate solvents and eluents. Similarly, pairs of cis and trans isomers can be separated by chromatography (e.g., flash column chromatography) using appropriate eluents. An optically pure trans isomer also can be converted to an optically pure cis isomer using suitable epimerization procedures. One such procedure comprises treating the trans isomer or a mixture (e.g., 1:1 mixture) of cis and trans isomers with methanolic or aqueous hydrogen chloride at a temperature of from 0° C. to the refluxing temperature of the solution. The mixture then can be subjected to chromatography (e.g., flash column chromatography) to separate the resulting diastereoisomers, or in the procedure utilizing aqueous hydrogen chloride the desired cis isomer precipitates out as the hydrochloride salt which then can be isolated by filtration.
Procedure (b)
This comprises a four-step procedure from a compound of formula (III) or a salt thereof (e.g., the hydrochloride salt). The procedure is particularly suitable for preparing a 1R, 3R isomer of formula (III) from a D-tryptophan alkyl ester of formula (IV) or a salt thereof (e.g., the hydrochloride salt). Thus, a first step (i) comprises treating a compound of formula (IV) with an acid halide R 2 COHal (where Hal is as previously defined) in the presence of a base, e.g., an organic base such as a trialkylamine (for example, triethylamine), to provide a compound of formula (IV) ##STR8##
The reaction can be conveniently carried out in a suitable solvent such as a halogenated hydrocarbon (e.g., dichloromethane) or an ether (e.g., tetrahydrofuran) and at a temperature of from -20° C. to +40° C.
Step (ii) comprises treating a compound of formula (IV) with an agent to convert the amide group to a thioamide group. Suitable sulphurating agents are well known in the art. Thus, for example, the reaction can be conveniently effected by treating (IV) with Lawesson's reagent. This reaction can be conveniently carried out in a suitable solvent such as an ether (e.g., dimethoxyethane) or an aromatic hydrocarbon (e.g., toluene) at an elevated temperature such as from 40° C. to 80° C. to provide a compound of formula (V) ##STR9##
Step (iii) comprises treating a compound of formula (V) with a suitable agent to provide a compound of formula (VI) ##STR10## (where Hal is a halogen atom, e.g., iodine). The reaction can be conveniently effected by treating (VI) with an alkylating agent such as a methyl halide (e.g., methyl iodide) or an acylating agent such as an acetyl halide (e.g., acetyl chloride) in a suitable solvent such as a halogenated hydrocarbon (e.g., dichloromethane) at an elevated temperature (e.g., under reflux).
In step (iv) the resulting iminium halide of formula (VI) can be treated with a reducing agent such as boron hydride, e.g., sodium borohydride, to provide the desired compound of formula (II). The reduction can be conveniently effected at a low temperature, e.g., within the range of -100° C. to 0° C., in a suitable solvent such as an alcohol (e.g., methanol).
According to a second process (B), a compound of formula (I) can be prepared by reaction of a compound of formula (VII) ##STR11## where Alk is as previously defined, with the imidazolide of R 1 --NH 2 under suitable conditions. Compounds of formula (VII) are known in the art and can be made by standard methods.
According to a third process (C), a compound of formula (1) where R 1 represents hydrogen can be prepared by reacting a compound of formula (VII) with urea at elevated temperature.
The pharmaceutically acceptable acid addition salts of the compounds of formula (I) which contain a basic center can be prepared in a conventional manner. For example, a solution of the free base can be treated with a suitable acid, either neat or in a suitable solution, and the resulting salt isolated either by filtration or by evaporation under vacuum of the reaction solvent. Pharmaceutically acceptable base addition salts can be obtained in an analogous manner by treating a solution of a compound of formula (I) with a suitable base. Both types of salt can be formed or interconverted using ion-exchange resin techniques.
Compounds of the invention can be isolated in association with solvent molecules by crystallization from or evaporation of an appropriate solvent.
Thus, according to a further aspect of the invention, we provide a process (D) for preparing a compound of formula (I) or a salt or solvate (e.g., hydrate) thereof which comprises process (A) as hereinbefore described followed by
i) an interconversion step, and/or either
ii) salt formation, or
ii) solvate (e.g., hydrate) formation.
The synthesis of the compounds of the invention and of the intermediates for use therein are illustrated by the following, nonlimiting Examples. The following abbreviations are used hereafter in the accompanying examples: rt (room temperature), min (minute), g (gram), mmol (millimole), m.p. (melting point), eq (equivalents), mL (milliliter), μL (microliters), NaHCO 3 (sodium bicarbonate), Na 2 SO 4 (sodium sulfate), MeOH (methyl alcohol), H 2 SO 4 (sulfuric acid), N 2 (nitrogen), and NH 4 OH (ammonium hydroxide), CH 2 Cl 2 (dichloromethane).
Intermediates 1 and 2
Methyl 1,2,3,4-tetrahydro-1-(3,4-methylenedioxyphenyl)-9H-pyrido[3,4-b]indole-3-carboxylate, cis and trans isomers
To a stirred solution of racemic tryptophan methyl ester (13 g) and piperonal (9.7 g) in anhydrous CH 2 Cl 2 (300 mL) cooled at 0° C. was added dropwise trifluoroacetic acid (9 mL) and the solution was allowed to react at ambient temperature. After four days, the yellow solution was diluted with CH 2 Cl 2 (100 mL), washed with a saturated aqueous solution of NaHCO 3 , then with water and dried over Na 2 SO 4 . The organic layer was evaporated to dryness under reduced pressure and the residue was purified by flash chromatography eluting with CH 2 Cl 2 /MeOH (99/1) to give first Intermediate 1, the cis isomer (6.5 g) m.p.: 90-93° C., followed by Intermediate 2, the trans isomer (6.4 g) m.p.: 170° C.
The following compounds were obtained in a similar manner:
Intermediates 3 and 4
Methyl 1,2,3,4-tetrahydro-1-(4-methoxyphenyl)-9H-pyrido [3,4-b]indole-3-carboxylate, cis and trans isomers
The same method as employed in the preparation of Intermediates 1 and 2 but starting from racemic tryptophan methyl ester and 4-methoxybenzaldehyde gave Intermediate 3, the cis isomer as white crystals m.p.: 142° C., and Intermediate 4, the trans isomer as white crystals m.p.: 209-210° C.
Intermediates 5 and 6
Methyl 1,2,3,4-tetrahydro-1-(2-thienyl)-9H-pyrido[3,4-b]indole-3-carboxylate, cis and trans isomers
The same method as employed in the preparation of Intermediates 1 and 2 but starting from racemic tryptophan methyl ester and 2-thiophenecarboxaldehyde gave Intermediate 5, the cis isomer as a pale yellow solid m.p.: 134-137° C., and Intermediate 6, the trans isomer as white crystals m.p.: 169° C.
Intermediate 7
Ethyl 1,2,3,4-tetrahydro-1-(4-dimethylaminophenyl)-9H-pyrido[3,4-b]indole-3-carboxylate, mixture of cis and trans isomers
The same method as employed in the preparation of Intermediates 1 and 2 but starting from racemic tryptophan ethyl ester and 4-dimethylaminobenzaldehyde gave the title compound as white crystals m.p.: 170° C.
Intermediates 8 and 9
Methyl 1,2,3,4-tetrahydro-6-fluoro-1-(4-methoxyphenyl)-9H-pyrido[3,4-b]indole-3-carboxylate, cis and trans isomers
The same method as employed in the preparation of Intermediates 1 and 2 but starting from racemic 5-fluoro-tryptophan methyl ester and 4-methoxybenzaldehyde gave Intermediate 8, the cis isomer as a solid 1H NMR (CDCl 3 ) δ (ppm) 7.4-6.8 (m, 8H), 5.15 (brs, 1H), 3.9 (dd, 1H), 3.8 (s, 3H), 3.2-2.9 (m, 2H), and Intermediate 9 the trans isomer as a solid m.p.: 197° C.
Intermediates 10 and 11
Methyl 1,2,3,4-tetrahydro-1-(4-chlorophenyl)-9H-pyrido[3,4-b]indole-3-carboxylate, cis and trans isomers
The same method as employed in the preparation of Intermediates 1 and 2, but starting from racemic tryptophan methyl ester and 4-chlorobenzaldehyde gave Intermediate 10, the cis isomer as white crystals m.p.: 208-209° C., and Intermediate 11, the trans isomer as white crystals m.p.: 108-109° C.
Intermediates 12 and 13
Methyl 1,2,3,4-tetrahydro-1-(4-trifluoromethylphenyl)-9H-pyrido[3,4-b]indole-3-carboxylate, cis and trans isomers
The same method but starting from racemic tryptophan methyl ester and 4-trifluoromethylbenzaldehyde gave Intermediate 12, the cis isomer as pale yellow crystals m.p.: 190° C., and Intermediate 13, the trans isomer as pale yellow crystals m.p.: 203° C.
Intermediates 14 and 15
Ethyl 1,2,3,4-tetrahydro-1-(4-cyanophenyl)-9H-pyrido[3,4-b]indole-3-carboxylate, cis and trans isomers
The same method but starting from racemic tryptophan ethyl ester and 4-cyanobenzaldehyde gave Intermediate 14, the cis isomer as white crystals m.p.: 200° C., and Intermediate 15, the trans isomer as white crystals m.p.: 156° C.
Intermediates 16 and 17
Ethyl 1,2,3,4-tetrahydro-1-(4-nitrophenyl)-9H-pyrido[3,4-b]indole-3-carboxylate, cis and trans isomers
The same method but starting from racemic tryptophan ethyl ester and 4-nitrobenzaldehyde gave Intermediate 16, the cis isomer as yellow crystals m.p.: 168° C., and Intermediate 17, the trans isomer as yellow crystals m.p.: 195° C.
Intermediates 18 and 19
Ethyl 1,2,3,4-tetrahydro-1-(3-pyridyl)-9H-pyrido-[3,4-b]indole-3-carboxylate, cis and trans isomers
The same method but starting from racemic tryptophan ethyl ester and 3-pyridinecarboxaldehyde gave Intermediate 18, the cis isomer as pale yellow crystals m.p.: 230-232° C., and Intermediate 19 the trans isomer as white crystals m.p.: 210-214° C.
Intermediates 20 and 21
Ethyl 1,2,3,4-tetrahydro-1-(3-thienyl)-9H-pyrido-[3,4-b]indole-3-carboxylate, cis and trans isomers
The same method as employed in the preparation of Intermediates 1 and 2 but starting from racemic tryptophan ethyl ester and 3-thiophenecarboxaldehyde gave Intermediate 20 the cis isomer as white crystals m.p.: 130° C., and Intermediate 21 the trans isomer as white crystals m.p.: 182-184° C.
Intermediate 22
Methyl 1,2,3,4-tetrahydro-1-(3-furyl)-9H-pyrido[3,4-b]indole-3-carboxylate, mixture of cis and trans isomers
The same method but starting from racemic tryptophan methyl ester and 3-furaldehyde gave the title compound as a yellow solid m.p.: 130° C.
Intermediates 23 and 24
(1R,3R)-Methyl 1,2,3,4-tetrahydro-1-(3,4-methylenedioxyphenyl)-9H-pyrido[3,4-b]indole-3-carboxylate, cis isomer and
(1S,3R)-methyl 1,2,3,4-tetrahydro-1-(3,4-methylenedioxyphenyl)-9H-pyrido[3,4-b]indole-3-carboxylate trans isomer
To a stirred solution of D-tryptophan methyl ester (11 g) and piperonal (7.9 g) in anhydrous CH 2 Cl 2 (400 mL) cooled at 0° C. was added dropwise trifluoroacetic acid (7.7 mL) and the solution was allowed to react at ambient temperature. After 4 days, the yellow solution was diluted with CH 2 Cl 2 (200 mL) and washed with a saturated aqueous solution of NaHCO 3 , then with water (3×200 mL) and dried over Na 2 SO 4 . The organic layer was evaporated under reduced pressure and the residue was purified by flash chromatography eluting with dichloromethane/ethyl acetate (97/3) to give first Intermediate 23 the cis isomer (6.5 g) m.p.: 154° C. followed by Intermediate 24 the trans isomer (8.4 g) m.p.: 188° C.
Intermediate 25
Ethyl 1,2,3,4-tetrahydro-6-methyl-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate, cis and trans isomers
To a stirred mixture of racemic 5-methyltryptophan (4 g) in 1N H 2 SO 4 (18 mL) and water (54 mL) was added benzaldehyde (2 mL) and the solution was heated at 80° C. under N 2 for 48 hours. The precipitated product was collected by filtration, washed with water and dried. The crude acid (4.5 g) was then dissolved in ethanol (100 mL) and the solution was cooled at -10° C. Thionyl chloride (1.2 mL) was added dropwise to the solution and the mixture was heated at 60° C. for 48 hours. The solvent was removed under reduced pressure and the residue was taken up in ice water and basified with NH 4 OH. The precipitated compound was washed with water, dried and purified by flash chromatography eluting with dichloromethane/methanol (98/2) to give first the cis isomer (1.7 g) m.p.: 128-130° C., followed by the trans isomer (0.53 g) m.p.: 198-200° C.
Intermediate 26
Ethyl 1,2,3,4-tetrahydro-6-bromo-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate, cis and trans isomers
The same procedure as described in the preparation of Intermediate 25 but starting from racemic 5-bromo-tryptophan and benzaldehyde gave the cis isomer as white crystals m.p.: 157-160° C. and the trans isomer as white crystals m.p.: 212-216° C.
Intermediate 27
Methyl 1,2,3,4-tetrahydro-1-(3-chlorophenyl)-9H-pyrido[3,4-b]indole-3-carboxylate, mixture of cis and trans isomers
The same method as employed in the preparation of Intermediate 1 and 2 but starting from racemic tryptophan methyl ester and 3-chlorobenzaldehyde gave the title compound as white solid m.p.: 150-160° C.
Intermediate 28
Methyl 1,2,3,4-tetrahydro-1-(4-fluorophenyl)-9H-pyrido[3,4-b]indole-3-carboxylate, cis and trans isomers
The same method as employed in the preparation of Intermediate 1 and 2 but starting from racemic tryptophan methyl ester and 4-fluorobenzaldehyde gave the cis isomer as white crystals m.p.: 92° C., and the trans isomer as pale yellow crystals m.p.: 183° C.
Intermediate 29
Methyl 1,2,3,4-tetrahydro-1-(4-hydroxyphenyl)-9H-pyrido[3,4-b]indole-3-carboxylate, trans isomer
To a stirred solution of racemic tryptophan methyl ester (3 g ) and 4-hydroxybenzaldehyde (1.84 g) in anhydrous dichloromethane (50 mL) cooled at 0° C. was added dropwise trifluoroacetic acid (1.27 mL) and the solution was allowed to react at ambient temperature. After 22 hours, the solution was washed with a saturated solution of NaHCO 3 , then with water, dried over Na 2 SO 4 and evaporated to dryness. The residue was purified by flash chromatography eluting with ethyl acetate to give the title compound (3.48 g) as an off-white solid m.p.: 233-235° C.
Example 1
Cis-2-benzyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido-[3,4-b]indole-1,3(2H)-dione and
Trans-2-benzyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido-[3,4-b]indole-1,3(2H)-dione
To a stirred solution of a mixture of cis and trans isomers of Intermediates 1 and 2 (1 g, 2.85 mmol) in 2-butanone (50 mL) was added dropwise benzyl isocyanate (0.37 mL, 2.99 mmol) and the mixture was refluxed for 15 hours. The solvent was then removed under reduced pressure and the residue was purified by flash chromatography eluting with toluene/ethyl acetate: 85/15 to give first, the trans isomer (240 mg) as white crystals after recrystallization from diethyl ether. m.p.: 208-210° C.
Analysis for C 27 H 21 N 3 O 4 : Calculated: C,71.83; H,4.69; N,9.31; Found: C,71.46; H,4.77; N,9.24%;
and followed by the cis isomer (470 mg) as white crystals after recrystallization from ethanol. m.p.: 159-161° C.
Analysis for C 27 H 21 N 3 O 4 : Calculated: C,71.83; H,4.69; N,9.31; Found: C,71.79; H,4.80; N,9.09%.
Example 2
Cis-5-(4-methoxyphenyl)-2-methyl-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 3 and methyl isocyanate gave after recrystallization from ethanol, the title compound as white crystals m.p.: 233-240° C.
Analysis for C 21 H 19 N 3 O 3 : Calculated: C,69.79; H,5.30; N,11.63; Found: C,69.63; H,5.29; N,11.68%.
Example 3
Cis-2-ethyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5': 1,6]pyrido[3,4-b]indole-1,3(2H)-dione and
Trans-2-ethyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from a mixture of Intermediates 3 and 4 and ethyl isocyanate gave the cis isomer as white crystals after recrystallization from ethanol m.p.: 210-220° C.
Analysis for C 22 H 21 N 3 O 3 : Calculated: C,70.38; H,5.64; N,11.19; Found: C,69.97; H,5.71; N,10.83%.
and the trans isomer as white crystals after recrystallization from 2-propanol m.p.: 245-248° C. Analysis for C 22 H 21 N 3 O 3 : Calculated: C,70.38; H,5.64; N,11.19; Found: C,70.28; H,5.76; N,11.22%.
Example 4
Trans-2-ethyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido-[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from the Intermediate 2 and ethyl isocyanate gave after recrystallization from ethyl acetate/hexane, the title compound as white crystals m.p.: 238° C.
Analysis for C 22 H 19 N 3 O 4 : Calculated: C,67.86; H,4.92; N,10.79; Found: C,68.32; H,4.90; N,10.90%.
Example 5
Trans-2-ethyl-5-(2-thienyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 6 and ethyl isocyanate gave after recrystallization from 2-propanol, the title compound as white crystals m.p.: 242-248° C.
Analysis for C 19 H 17 N 3 O 2 S: Calculated: C,64.94; H,4.88; N, 11.96; Found: C,64.79; H,5.00; N,11.88%.
Example 6
Trans-5-(4-dimethylaminophenyl)-2-ethyl-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from a mixture of cis and trans isomers of Intermediate 7 and ethyl isocyanate gave after recrystallization from methanol, the title compound as white crystals m.p.: 262-265° C.
Analysis for C 23 H 24 N 4 O 2 : Calculated: C,71.11; H,6.23; N,14.42; Found: C,71.01; H,6.29; N,14.49%.
Example 7
Trans-2-butyl-9-methyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from the trans isomer of Intermediate 25 and butyl isocyanate gave after recrystallization from diisopropyl ether, the title compound as white crystals m.p.: 196-198° C.
Analysis for C 24 H 25 N 3 O 2 : Calculated: C,74.39; H,6.50; N,10.84; Found: C,74.38; H,6.52; N,10.63%.
Example 8
Trans-9-bromo-2-butyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from the trans isomer of Intermediate 26 and butyl isocyanate gave after recrystallization from diisopropyl ether, the title compound as white crystals m.p.: 207-210° C.
Analysis for C 23 H 22 BrN 3 O 2 : Calculated: C,61.07; H,4.90; Br,17.66; N,9.29; Found: C,61.28; H,4.95; Br,17.53; N,9.10%.
Example 9
Cis-2-butyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6] pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from the Intermediate 3 and butyl isocyanate gave after recrystallization from methanol, the title compound as white crystals m.p.: 220-225° C.
Analysis for C 24 H 25 N 3 O 3 : Calculated: C,71.44; H,6.25; N,10.41; Found: C,71.56; H,6.23; N,10.36%.
Example 10
Trans-2-butyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from the Intermediate 4 and butyl isocyanate gave after recrystallization from ethanol/water, the title compound as white crystals m.p.: 173-174° C.
Analysis for C 24 H 25 N 3 O 3 : Calculated: C,71.44; H,6.25; N,10.41; Found: C,71.53; H,6.20; N,10.28%.
Example 11
Cis-2-butyl-9-fluoro-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 8 and butyl isocyanate gave after recrystallization from methanol, the title compound as white crystals m.p.: 125-130° C.
Analysis for C 24 H 24 FN 3 O 3 (0.3H 2 O) Calculated: C,67.53; H,5.81; N,9.84; Found: C,67.19; H,5.74; N,9.85%.
Example 12
Trans-2-butyl-9-fluoro-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo [1',5':1,6]pyrido-[3,4-b]indole-1,3 (2H)-dione
The same method as employed in the preparation of Example 1 but starting from the Intermediate 9 and butyl isocyanate gave after recrystallization from diisopropyl ether/pentane, the title compound as white crystals m.p.: 187-189° C.
Analysis for C 24 H 24 FN 3 O 3 : Calculated: C,68.39; H,5.74; N,9.97; Found: C,68.61; H,5.71; N,10.04%.
Example 13
Trans-2-butyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 2 and butyl isocyanate gave after recrystallization from 2-propanol, the title compound as white crystals m.p.: 152° C.
Analysis for C 24 H 23 N 3 O 4 : Calculated: C,69.05; H,5.55; N,10.07; Found: C,68.93; H,5.49; N,9.99%.
Example 14
Cis-2-butyl-5-(3-chlorophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione and
Trans-2-butyl-5-(3-chlorophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from a mixture of cis and trans isomers of Intermediate 27 and butyl isocyanate gave the cis isomer as pale yellow crystals after recrystallization from diethyl ether/cyclohexane m.p.: 215-217° C.
Analysis for C 23 H 22 ClN 3 O 2 : Calculated: C,67.73; H,5.44; Cl,8.69; N,10.30; Found: C,67.62; H,5.49; Cl,8.59; N,10.03%.
and the trans isomer as white crystals after recrystallization from ethanol m.p.: 207-209° C. Analysis for C 23 H 22 ClN 3 O 2 : Calculated: C,67.73; H,5.44; Cl,8.69; N,10.30; Found: C,67.60; H,5.41; Cl,8.77; N,10.20%.
Example 15
Cis-2-butyl-5-(4-chlorophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 10 and butyl isocyanate gave after recrystallization from methanol, the title compound as pale yellow crystals m.p.: 252° C.
Analysis for C 23 H 22 ClN 3 O 2 : Calculated: C,67.73; H,5.44; Cl,8.69; N,10.30; Found: C,67.60; H,5.44; Cl,8.55; N,10.30%.
Example 16
Trans-2-butyl-5-(4-chlorophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 11 and butyl isocyanate gave after recrystallization from methanol, the title compound as pale yellow crystals m.p.: 174° C.
Analysis for C 23 H 22 ClN 3 O 2 : Calculated: C,67.73; H,5.44; Cl,8.69; N,10.30; Found: C,67.75; H,5.49; Cl,8.75; N,10.46%.
Example 17
Trans-2-butyl-5-(4-fluorophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from the trans isomer of Intermediate 28 and butyl isocyanate gave after recrystallization from 2-propanol, the title compound as pale yellow crystals m.p.: 242° C.
Analysis for C 23 H 22 FN 3 O 2 : Calculated: C,70.57; H,5.66; F,4.85; N,10.73; Found: C,70.57; H,5.63; F,4.66; N,10.83%.
Example 18
Trans-2-butyl-5-(4-hydroxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 29 and butyl isocyanate gave after recrystallization from 2-propanol/water, the title compound as white crystals m.p.: 259° C.
Analysis for C 23 H 23 N 3 O 3 : Calculated: C,70.93; H,5.95; N,10.79; Found: C,70.41; H,6.04; N,10.63%.
Example 19
Cis-2-butyl-5-(4-trifluoromethylphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 12 and butyl isocyanate gave after recrystallization from methanol/water, the title compound as pale yellow crystals m.p.: 232° C.
Analysis for C 24 H 22 F 3 N 3 O 2 : Calculated: C,65.30; H,5.02; F,12.91; N,9.52; Found: C,65.29; H,5.05; F,12.56; N,9.37%.
Example 20
Cis-2-butyl-5-(4-cyanophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as used in the preparation of Example 1 but starting from Intermediate 14 and butyl isocyanate gave after recrystallization from 2-propanol, the title compound as white crystals m.p.: 260° C.
Analysis for C 24 H 22 N 4 O 2 : Calculated: C,72.34; H,5.57; N,14.06; Found: C,72.30; H,5.59; N,14.08%.
Example 21
Trans-2-butyl-5-(4-cyanophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 15 and butyl isocyanate gave after recrystallization from diethyl ether/cyclohexane, the title compound as white crystals m.p.: 158° C.
Analysis for C 24 H 22 N 4 O 2 : Calculated: C,72.34; H,5.57; N,14.06; Found: C,72.40; H,5.56; N,13.95%.
Example 22
Cis-2-butyl-5-(4-nitrophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
Trans-2-butyl-5-(4-nitrophenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from a mixture of Intermediates 16 and 17 and butyl isocyanate gave the cis isomer as yellow crystals after recrystallization from methanol m.p.: 236° C.
Analysis for C 23 H 22 N 4 O 4 : Calculated: C,66.02; H,5.30; N,13.39; Found: C,65.82; H,5.36; N,13.25%.
and the trans isomer as yellow crystals after recrystallization from 2-propanol m.p.: 206° C.
Analysis for C 23 H 22 N 4 O 4 Calculated: C,66.02; H,5.30; N,13.39; Found: C,66.12; H,5.38; N,13.28%.
Example 23
Cis-2-butyl-5-(3-pyridyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 18 and butyl isocyanate gave after recrystallization from 2-propanol, the title compound as white crystals m.p.: 257-263° C.
Analysis for C 22 H 22 N 4 O 2 : Calculated: C,70.57; H,5.92; N,14.96; Found: C,70.38; H,6.07; N,14.88%.
Example 24
Cis-2-butyl-5-(3-thienyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione and
Trans-2-butyl-5-(3-thienyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from a mixture of Intermediates 20 and 21 and butyl isocyanate gave the cis isomer as white crystals after recrystallization from 2-propanol m.p.: 219-221° C.
Analysis for C 21 H 21 N 3 O 2 S: Calculated: C,66.47; H,5.58; N,11.07; S,8.45; Found: C,66.13; H,5.68; N,11.00; S,8.27%.
and the trans isomer as white crystals after recrystallization from ethyl acetate m.p.: 240-242° C.
Analysis for C 21 H 21 N 3 O 2 S: Calculated: C,66.47; H,5.58; N,11.07; S,8.45; Found: C,66.68; H,5.69; N,11.05; S,8.56%.
Example 25
Cis-2-butyl-5-(3-furyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione and
Trans-2-butyl-5-(3-furyl)-5,6,11,11a-tetrahydro-1H-[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method but starting from a mixture of cis and trans isomers Intermediate 22 and butyl isocyanate gave the cis isomer as white crystals after recrystallization from toluene m.p.: 155-160° C.
Analysis for C 21 H 21 N 3 O 3 : Calculated: C,69.41; H,5.82; N,11.56; Found: C,69.44; H,5.86; N,11.52%.
and the trans isomer as pale yellow crystals after recrystallization from ethanol m.p.: 215-219° C.
Analysis for C 21 H 21 N 3 O 3 : Calculated: C,69.41; H,5.82; N,11.56; Found: C,69.43; H,5.73; N,11.46%.
Example 26
Cis-2-cyclohexyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione and
Trans-2-cyclohexyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from a mixture of Intermediates 3 and 4 and cyclohexyl isocyanate gave the cis isomer as white crystals after recrystallization from ethanol m.p.: 250-260° C.
Analysis for C 26 H 27 N 3 O 3 : Calculated: C,72.71; H,6.34; N,9.78; Found: C,72.73; H,6.39; N,9.63%.
and the trans isomer as white crystals after recrystallization from 2-propanol m.p.: 265-269° C. Analysis for C 26 H 27 N 3 O 3 : Calculated: C,72.71; H,6.34; N,9.78; Found: C,72.82; H,6.38; N,9.69%.
Example 27
Cis-2-cyclohexyl-9-fluoro-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 8 and cyclohexyl isocyanate gave after recrystallization from methanol, the title compound as white crystals m.p.: 275-278° C.
Analysis for C 26 H 26 FN 3 O 3 : Calculated: C,69.78; H,5.86; N,9.39; Found: C,69.75; H,5.85; N,8.96%.
Example 28
Trans-2-cyclohexyl-9-fluoro-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 9 and cyclohexyl isocyanate gave after recrystallization from ethanol, the title compound as white crystals m.p.: 265-267° C.
Analysis for C 26 H 26 FN 3 O 3 : Calculated: C,69.78; H,5.86; N,9.39; Found: C,69.71; H,5.91; N,9.37%.
Example 29
Trans-2-benzyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from trans methyl 1,2,3,4-tetrahydro-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate (see J. Cook et al., Heterocycles, 4(7), 1249-1255 (1976)) and benzyl isocyanate gave after recrystallization from diethyl ether, the title compound as white crystals m.p.: 200-202° C.
Analysis for C 26 H 21 N 3 O 2 : Calculated: C,76.64; H,5.19; N,10.31; Found: C,76.75; H,5.18; N,10.23%.
Example 30
Cis-2-benzyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 3 and benzyl isocyanate gave after recrystallization from ethanol, the title compound as pale yellow crystals m.p.: 240-243° C.
Analysis for C 27 H 23 N 3 O 3 : Calculated: C,74.13; H,5.30; N,9.60; Found: C,74.13; H,5.31; N,9.58%.
Example 31
Trans-2-benzyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 4 and benzyl isocyanate gave after recrystallization from 2-propanol, the title compound as white crystals m.p.: 208-212° C.
Analysis for C 27 H 23 N 3 O 3 : Calculated: C,74.13; H,5.30; N,9.60; Found: C,74.25; H,5.47; N,9.49%.
Example 32
(5R,11aR)-2-benzyl-5-(3,4-methylenedioxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo-[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 23 and benzyl isocyanate, gave after recrystallization toluene, the title compound as white crystals m.p.: 145° C.
Analysis for C 27 H 21 N 3 O 4 : Calculated: C,71.83; H,4.69; N,9.31; Found: C,71.47; H,4.74; N,9.28%.
Example 33
Trans-2-benzyl-5-(4-hydroxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 29 and benzyl isocyanate gave after recrystallization from methanol, the title compound as white crystals m.p.: 268-272° C. Analysis for C 26 H 21 N 3 O 3 : Calculated: C,73.74; H,5.00; N,9.92; Found: C,73.63; H,5.09; N,10.02%.
Example 34
Trans-2-(2-chloroethyl)-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 4 and 2-chloroethyl isocyanate, gave after recrystallization from diethyl ether/hexane, the title compound as white crystals m.p.: 218-219° C.
Analysis for C 22 H 20 ClN 3 O 3 : Calculated: C,64.47; H,4.92; Cl,8.65; N,10.25; Found: C,64.44; H,4.98; Cl,8.81; N,10.20%.
Example 35
Cis-2-benzyl-5-cyclohexyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from cis methyl 1,2,3,4-tetrahydro-1-cyclohexyl-9H-pyrido[3,4-b]indole-3-carboxylate (see J. Cook et al., Heterocycles, 4(7), 1249-1255 (1976)) and benzyl isocyanate gave after recrystallization from methanol, the title compound as white crystals m.p.: 170-173° C.
Analysis for C 26 H 27 N 3 O 2 : Calculated: C,75.52; H,6.58; N,10.16; Found: C,75.63; H,6.48; N,9.75%.
Example 36
Trans-2-benzyl-5-cyclohexyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from trans methyl 1,2,3,4-tetrahydro-1-cyclohexyl-9H-pyrido[3,4-b]indole-3-carboxylate (see J. Cook et al., Heterocycles, 4(7), 1249-1255 (1976)) and benzyl isocyanate gave after recrystallization from methanol, the title compound as white crystals m.p.: 130-135° C.
Analysis for C 26 H 27 N 3 O 2 : Calculated: C,75.52; H,6.58; N,10.16; Found: C,75.74; H,6.67; N,9.94%.
Example 37
Trans-2-butyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from trans methyl 1,2,3,4-tetrahydro-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate and butyl isocyanate gave after recrystallization from 2-propanol, the title compound as white crystals m.p.: 240-243° C.
Analysis for C 23 H 23 N 3 O 2 : Calculated: C,73.97; H,6.21; N,11.25; Found: C,73.95; H,6.32; N,11.28%.
Example 38
Trans-2-cyclohexyl-5-phenyl-5 6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from trans methyl 1,2,3,4-tetrahydro-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate and cyclohexyl isocyanate gave after recrystallization from methanol, the title compound as white crystals m.p.: 248-250° C.
Analysis for C 25 H 25 N 3 O 2 : Calculated: C,75.16; H,6.31; N,10.52; Found: C,75.23; H,6.33; N,10.60%.
Example 39
Cis-2-cyclohexyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from cis methyl 1,2,3,4-tetrahydro-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate and cyclohexyl isocyanate gave after recrystallization from methanol, the title compound as white crystals m.p.: 267-270° C.
Analysis for C 25 H 25 N 3 O 2 : Calculated: C,75.16; H,6.31; N,10.52; Found: C,75.20; H,6.33; N,10.52%.
Example 40
Trans-2-ethoxycarbonylmethyl-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 1 but starting from Intermediate 4 and ethyl isocyanatoacetate gave after recrystallization from ethanol, the title compound as white crystals m.p.: 165-167° C.
Analysis for C 24 H 23 N 3 O 5 : Calculated: C,66.50; H,5.35; N,9.69; Found: C,66.66; H,5.32; N,9.66%.
Example 41
Trans-5-(4-methoxyphenyl)-2-[2-(2-pyridyl)-ethyl]-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
To a stirred solution of carbonyl diimidazole (0.28 g, 1.72 mmol) in dry tetrahydrofuran (5 mL), was added dropwise a solution of 2-(2-aminoethyl)pyridine (0.205 g, 1.68 mmol) in tetrahydrofuran (3 mL) and the solution was stirred at room temperature for 0.5 hour. Then, a solution of Intermediate 4 (0.5 g, 1.43 mmol) in dry tetrahydrofuran (7 mL) was added and the resulting solution was refluxed for 20 hours. The solvant was removed under reduced pressure and the residue was dissolved in dichloromethane (50 mL). The solution was washed three times with water (3×20 mL), dried over Na2SO4 and concentrated. The residue was then purified by flash chromatography eluting with dichloromethane/methanol: 99/1 and recrystallised from ethanol/water to give the title compound (0.35 g) as white crystals m.p.: 140-143° C.
Analysis for C 27 H 24 N 4 O 3 : Calculated: C,71.67; H,5.35; N,12.38; Found: C,71.87; H,5.41; N,12.28%.
Example 42
Trans-2-cyclopropyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 41 but starting from trans methyl 1,2,3,4-tetrahydro-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate and cyclopropylamine gave after recrystallization from ethanol, the title compound as white crystals m.p.: 250-255° C.
Analysis for C 22 H 19 N 3 O 2 : Calculated: C,73.93; H,5.36; N,11.76; Found: C,73.84; H,5.45; N,11.63%.
Example 43
Trans-2-phenethyl-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 41 but starting from trans methyl 1,2,3,4-tetrahydro-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate and phenethylamine gave after recrystallization from diethyl ether, the title compound as white crystals m.p.: 240-242° C.
Analysis for C 27 H 23 N 3 O 2 : Calculated: C,76.94; H,5.50; N,9.97; Found: C,77.20; H,5.65; N,10.05%.
Example 44
Trans-5-phenyl-2-(2-pyridylmethyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 41 but starting from trans methyl 1,2,3,4-tetrahydro-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate and 2-(aminomethyl) pyridine, gave after recrystallization from methanol, the title compound as white crystals m.p.: 165-175°.
Analysis for C 25 H 20 N 4 O 2 : Calculated: C,73.51; H,4.94; N,13.72; Found: C,73.46; H5.29; N,13.84%.
Example 45
Trans-5-phenyl-2-(4-pyridylmethyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 41 but starting from trans methyl 1,2,3,4-tetrahydro-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate and 4-(aminomethyl) pyridine, gave after recrystallization from methanol, the title compound as white crystals m.p.: 247-249° C.
Analysis for C 25 H 20 N 4 O 2 : Calculated: C,73.51; H,4.94; N,13.72; Found: C,73.41; H,4.98; N,13.62%.
Example 46
Trans-5-(4-methoxyphenyl)-2-(3-pyridylmethyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 41 but starting from Intermediate 4 and 3-(aminomethyl) pyridine, gave after recrystallization from ethanol, the title compound as white crystals m.p.: 160-165° C. Analysis for C 26 H 22 N 4 O 3 : Calculated: C,71.22; H,5.06; N,12.78; Found: C,71.12; H,5.15; N,12.59%.
Example 47
Trans-2-(2-dimethylaminoethyl)-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 41 but starting from Intermediate 4 and N,N-dimethyl-ethane-1,2-diamine, gave after recrystallization from ethanol/water, the title compound as pale yellow crystals m.p.: 120-124° C.
Analysis for C 24 H 26 N 4 O 3 : Calculated: C,68.88; H,6.26; N,13.39; Found: C,68.91; H,6.43; N,13.23%.
Example 48
Trans-2-(3-dimethylaminopropyl)-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 41 but starting from Intermediate 4 and N,N-dimethyl-propane-1,3-diamine, gave after recrystallization from ethyl acetate/hexane, the title compound as white crystals m.p.: 159-161° C. Analysis for C 25 H 28 N 4 O 3 : Calculated: C,69.42; H,6.53; N,12.95; Found: C,68.89; H,6.60; N,12.91%.
Example 49
Trans-2-(2-morpholin-4-yl-ethyl)-5-phenyl-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 41 but starting from trans methyl 1,2,3,4-tetrahydro-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate and 2-morpholin-4-yl-ethylamine, gave after recrystallization from ethanol, the title compound as white crystals m.p.: 183-185° C.
Analysis for C 25 H 26 N 4 O 3 : Calculated: C,69.75; H,6.09; N,13.01; Found: C,69.68; H,6.17; N,12.80%.
Example 50
Trans-5-(4-methoxyphenyl)-2-[3-(4-methyl-piperazin-1-yl)-propyl]-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 41 but starting from Intermediate 4 and 3-(4-methyl-piperazin-1-yl)-propylamine, gave after recrystallization from ethanol/water, the title compound as white crystals m.p.: 164-168° C.
Analysis for C 28 H 33 N 5 O 3 (0.5 H 2 O): Calculated: C,67.72; H,6.9; N,14.1; Found: C,67.85; H,6.75; N,14.13%.
Example 51
Trans-5-(4-methoxyphenyl)-2-(2-pyrrolidin-1-yl-ethyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 41 but starting from Intermediate 4 and 2-pyrrolidin-1-yl-ethylamine, gave after recrystallization from ethanol/water, the title compound as white crystals m.p.: 126-130° C. Analysis for C 26 H 28 N 4 O 3 : Calculated: C,70.25; H,6.35; N,12.60; Found: C,69.99; H,6.35; N,12.50%.
Example 52
Trans-5-(4-methoxyphenyl)-2-[2-(1-methyl-pyrrolidin-2-yl)-ethyl]-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 41 but starting from Intermediate 4 and 2-(1-methyl-pyrrolidin-2-yl)-ethylamine, gave after recrystallization from methanol, the title compound as white crystals m.p.: 170-180° C.
Analysis for C 27 H 30 N 4 O 3 : Calculated: C,70.72; H,6.59; N,12.22; Found: C,70.86; H,6.62; N,12.41%.
Example 53
Trans-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo-[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
A mixture of Intermediate 4 (0.5 g, 1.48 mmol) and urea (0.1 g) was heated at 220° C. for a few minutes. The reaction was then cooled to room temperature and the solid suspended in methanol, filtered then recrystallised from hot methanol to give the title compound as off-white crystals m.p.: 295-305° C.
Analysis for C 20 H 17 N 3 O 3 : Calculated: C,69.15; H,4.93; N,12.10; Found: C,68.87; H,4.95; N,12.00%.
Example 54
Cis-5-(4-methoxyphenyl)-5,6,11,11a-tetrahydro-1H-imidazo[1',5':1,6]pyrido[3,4-b]indole-1,3(2H)-dione
The same method as employed in the preparation of Example 53 but starting from Intermediate 3 and urea, gave after recrystallization from methanol, the title compound as pale yellow crystals m.p.: 300-310° C.
Analysis for C 20 H 17 N 3 O 3 : Calculated: C,69.15; H,4.93; N,12.10; Found: C,68.90; H,4.91; N,11.98%.
Tablets for Oral Administration
A. Direct Compression
______________________________________1. mg/tablet______________________________________Active Ingredient 50.0 Crospovidone USNF 8.0 Magnesium Stearate Ph Eur 1.0 Anhydrous Lactose 141.0______________________________________
The active ingredient was sieved and blended with the excipients. The resultant mix was compressed into tablets.
______________________________________2. mg/tablet______________________________________Active Ingredient 50.0 Colloidal Silicon Dioxide 0.5 Crospovidone 8.0 Sodium Lauryl Sulfate 1.0 Magnesium Stearate Ph Eur 1.0 Microcrystalline Cellulose USNF 139.5______________________________________
The active ingredient was sieved and blended with the excipients. The resultant mix was compressed into tablets.
B. Wet Granulation
______________________________________1. mg/tablet______________________________________Active Ingredient 50.0 Polyvinylpyrrolidone 150.0 Polyethylene glycol 50.0 Polysorbate 80 10.0 Magnesium Stearate Ph Eur 2.5 Croscamellose Sodium 25.0 Colloidal Silicon Dioxide 2.5 Microcrystalline Cellulose USNF 210.0______________________________________
The polyvinylpyrrolidone, polyethylene glycol and polysorbate 80 were dissolved in water. The resultant solution was used to granulate the active ingredient. After drying the granules were screened, then extruded at elevated temperatures and pressures. The extrudate was milled and/or screened then was blended with the microcrystalline cellulose, croscarmellose sodium, colloidal silicon dioxide, and magnesium stearate. The resultant mix was compressed into tablets.
______________________________________2. mg/tablet______________________________________Active Ingredient 50.0 Polysorbate 80 3.0 Lactose Ph Eur 178.0 Starch BP 45.0 Pregelatinized Maize Starch BP 22.5 Magnesium Stearate BP 1.5______________________________________
The active ingredient was sieved and blended with the lactose, starch, and pregelatinised maize starch. The polysorbate 80 was dissolved in purified water. Suitable volumes of the polysorbate 80 solution were added and the powders were granulated. After drying, the granules were screened and blended with the magnesium stearate. The granules then were compressed into tablets.
Tablets of other strengths can be prepared by altering the ratio of active ingredient to the other excipients.
Film Coated Tablets
The aforementioned tablet formulations were film coated.
______________________________________Coating Suspension % w/w______________________________________Opadry white † 13.2 Purified water Ph Eur to 100.0*______________________________________ † Opadry white is a proprietary material obtaining from Colorcon Limited, UK, which contains hydroxypropyl methylcellulose, titanium dioxide, and triacetin. *The water did not appear in the final product. The maximum theoretical weight of solids applied during coating was 20 mg/tablet.
The tablets were film coated using the coating suspension in conventional film coating equipment.
Capsules
______________________________________1. mg/capsule______________________________________Active Ingredient 50.0 Lactose 148.5 Polyvinylpyrrolidone 100.0 Magnesium Stearate 1.5______________________________________
The active ingredient was sieved and blended with the excipients. The mix was filled into size No. 1 hard gelatin capsules using suitable equipment.
______________________________________2. mg/capule______________________________________Active Ingredient 50.0 Microcrystalline Cellulose 233.5 Sodium Lauryl Sulfate 3.0 Crospovidone 12.0 Magnesium Stearate 1.5______________________________________
The active ingredient was sieved and blended with the excipients. The mix was filled into size No. 1 hard gelatin capsules using suitable equipment.
Other doses can be prepared by altering the ratio of active ingredient to excipient, the fill weight and if necessary changing the capsule size.
______________________________________3. mg/capsule______________________________________Active Ingredient 50.0 Labrafil M1944CS to 1.0 ml______________________________________
The active ingredient was sieved and blended with the Labrafil. The suspension was filled into soft gelatin capsules using appropriate equipment.
Inhibitory Effect on cGMP-PDE
cGMP-PDE activity of compounds of the present invention was measured using a one-step assay adapted from Wells et al., Biochim. Biophys. Acta, 384, 430 (1975). The reaction medium contained 50 mM Tris-HCl, pH 7.5, 5 mM magnesium acetate, 250 μg/ml 5'-Nucleotidase, 1 mM EGTA, and 0.15 μM 8-[H 3 ]-cGMP. The enzyme used was a human recombinant PDE5 (ICOS Corp., Bothell, Wash.).
Compounds of the invention were dissolved in DMSO finally present at 2% in the assay. The incubation time was 30 minutes during which the total substrate conversion did not exceed 30%.
The IC 50 values for the compounds examined were determined from concentration-response curves typically using concentrations ranging from 10 nM to 10 μM. Tests against other PDE enzymes using standard methodology also showed that compounds of the invention are highly selective for the cGMP-specific PDE enzyme.
cGMP Level Measurements
Rat aortic smooth muscle cells (RSMC), prepared according to Chamley et al., Cell Tissue Res., 177, 503-522 (1977), were used between the 10th and 25th passage at confluence in 24-well culture dishes. Culture media was aspirated and replaced with PBS (0.5 ml) containing the compound tested at the appropriate concentration. After 30 minutes at 37° C., particulates guanylate cyclase was stimulated by addition of ANF (100 nM) for 10 minutes. At the end of incubation, the medium was withdrawn, and two extractions were performed by addition of 65% ethanol (0.25 ml). The two ethanolic extracts were pooled and evaporated until dryness, using a Speed-vac system. cGMP was measured after acetylation by scintillation proximity immunoassay (AMERSHAM). The EC 50 values are expressed as the dose-giving half of the stimulation at saturating concentrations.
Biological Data
The compounds according to the present invention were typically found to exhibit an IC 50 value of less than 500 nM and an EC 50 value of less than 5 μM. In vitro test data for representative compounds of the invention is given in the following table:
TABLE 1______________________________________In vitro results Example No. IC.sub.50 nM EC.sub.50 μM______________________________________10 4 <1 26 (cis isomer) 7 0.3 1 (cis isomer) <10 0.3 32 <10 0.2______________________________________
The hypotensive effects of compounds according to the invention as identified in Table 2 were studied in conscious spontaneously hypertensive rats (SHRs). The compounds were administered orally at a dose of 5 or 10 mg/kg in a mixture of 5% DMF (dimethylformamide) and 95% olive oil, or i.v. at a dose of 10 mg/kg in a mixture of 40% dimethylformamide, 25% tetraglycol, and 25% glucose serum. Blood pressure was measured from a catheter inserted in the carotid artery and recorded for 5 hours after administration. The results are expressed as Area Under the Curve (AUC from 0 to 5 hours in mmHg.hour) of the fall in blood pressure over time.
TABLE 2______________________________________In vivo results Example No. AUC (mmHg · H)______________________________________10 147 (dosed at 10 mg/kg i.v.) 26 (cis iosmer) 117 (dosed at 10 mg/kg i.v.) 1 (cis isomer) 104 (dosed at 5 mg/kg p.o.) 32 65 (dosed at 5 mg/kg p.o.)______________________________________
Obviously, many modifications and variations of the invention as hereinbefore set forth can be made without departing from the spirit and scope thereof, and, therefore, only such limitations should be imposed as are indicated by the appended claims.
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Compounds of the general structural formula ##STR1## and use of the compounds and salts and solvates thereof, as therapeutic agents.
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This is a continuation of application(s) Ser. No. 08/377,450 filed on Jan. 24, 1995, now abandoned. Ser. No. 08/060,653 filed on May 13, 1993, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to the storage of data on magnetic recording tape, and more specifically, to the storage of digital data in helical format on a magnetic tape housed within a single reel tape cartridge.
2. Related Art
The data processing industry stores large amounts of digital data on magnetic tapes. The 3480 tape cartridge (developed by IBM Corporation, Armonk, N.Y., U.S.A.) is an industry standard for magnetic storage media. The 3480 cartridge is a single reel cartridge with a length of ½ inch wide magnetic tape stored on it. The cartridge housing protects the tape from damage while allowing the tape reel to be driven from a drive mechanism on the underside of the cartridge housing. The tape is withdrawn from an opening formed at one corner of the cartridge. A leader block attached to a free end of the tape allows the tape to be withdrawn from the cartridge for read/write operations.
Read/write operations are performed by a tape “transport.” The standard tape transport accepts the tape cartridge into an elevator assembly. A threading mechanism grabs the leader block and pulls it free from the cartridge. The leader block is then used to thread the tape through a series of guide posts, across a longitudinal read/write head, and into a slot in a take-up reel. Once threaded, the tape from the cartridge can be driven across the read/write heads for data transfer operations.
The standard 3480 cartridge contains 541 feet of tape. Data is stored on the tape in an 18 track format, typically providing approximately 200 MB (megabytes) of data storage capacity.
For automated storage and handling of large numbers of 3480 cartridges, automated mass storage systems have been developed. For example, the 4400 automated cartridge system (ACS) from Storage Technology Corporation, Louisville, Colo., U.S.A., is capable of storing up to 6,000 3480 cartridges. The 4400 ACS can quickly locate a selected cartridge and load it into a cartridge transport for read/write operations. The Model 4400 ACS typically has between one and four cartridge transports associated with it.
The 4400 ACS has proven to be a cost-effective data storage system. With each of 6,000 cartridges providing 200 megabytes of storage capacity, one 4400 ACS has a total capacity of 1.2 terabytes (1.2×10 12 bytes). This storage capacity is provided in a unit that occupies approximately 100 square feet of floor space. Nevertheless, it is desirable to increase the storage density of the 4400 ACS.
Data is currently stored on a 3480 cartridge in an 18 track longitudinal format. However, it is known in the industry that using a helical scan data storage format would allow approximately a 100 times increase in storage capacity. In other words, the typical 3480 cartridge would have a helical scan storage capacity of 25 gigabytes rather than the 200 megabytes of the longitudinal format. At 25 gigabytes per cartridge, the 4400 ACS would provide a total storage capacity of 150 terabytes. Thus, helical-scan technology holds promise for increasing the storage capacity of the 4400 ACS by a factor of greater than 100 by simply changing the format with which data is stored in each tape cartridge.
Changing the data storage format for a cartridge necessitates that a new transport be developed. Helical scan transports have gained widespread use in the video industry. However, a helical-scan transport for a one-half inch tape cartridge is not currently commercially available.
The helical scan transport is quite different than the longitudinal style transport. The helical scan transport includes a cylindrical rotating head around which the tape must be wrapped for read/write operations. The helical scan tape path is much more complex than the path for longitudinal transports.
The video industry has adopted a two reel magnetic tape cassette as its standard media. Loading of the tape from a cassette through the tape path of a helical scan transport is straightforward and well known in the art. The loading of tape from a cartridge through a helical scan tape path, however, is more difficult and has not been developed to the level of that for a cassette. Thus, two standard and distinct media form factors have developed for the video industry and the data processing industry. The form factors are incompatible. 3480 style cartridges cannot be used with the helical-scan cassette transports of the video industry.
One apparent reason for the data processing industry's selection of the cartridge as its standard data storage media is volumetric economy. By not including a take-up reel, the cartridge is roughly one-half the size of a cassette for the same tape length. Thus, a cartridge has twice the storage capacity per unit volume of a cassette.
While a helical-scan transport is not commercially available for a one-half inch tape cartridge, one is described in commonly owned U.S. Pat. No. 5,128,815 to Leonhardt et al. Leonhardt et al. teach positioning a cartridge and a take-up reel in a helical transport so that a cassette is emulated. This simplifies tape loading. However, such a design would have a form factor incompatible with the 4400 ACS. That is, the physical layout and dimensioning would not allow the resulting transport to be used with existing 4400 ACS equipment without substantial modification. This is a critical concern in the computer and data processing industry. New technologies and advancements must be compatible with existing technologies. For example, to have maximum utility, a helical-scan transport must have a form factor compatible with the 4400 ACS environment.
An important feature of the form factor of such a transport is the frontal surface area. That is, the front face of the transport which contains the opening for accepting a tape cartridge must be small enough to interface with other equipment. Form factors such as that disclosed by Leonhardt et al. in the '815 patent may have too large a frontal area for many applications because of the side-by-side arrangement of the cartridge and the take-up reel.
What is needed is a helical scan transport which can store data on and retrieve data from a 3480 or similar data cartridge and which has a form factor compatible with existing data storage systems (e.g., the Storage Technology Corporation Model 4400 ACS).
SUMMARY OF THE INVENTION
The invention is a helical scan transport for a magnetic tape cartridge. The transport has a substantially linear tape loading path and a form factor which allows its use with a Storage Technology Corporation Model 4400 automated cartridge system (also known as a data cartridge storage “library”). A new helical scan tape cartridge was developed for use with the transport of the invention. The helical cartridge has a form factor similar to the 3480 style cartridge. Thus, the 4400 ACS can store both the helical cartridges and the 3480 style cartridges. By producing a helical scan transport and helical cartridge which are compatible with existing automated cartridge systems, the data storage capacity of existing systems can be vastly increased without the need for retrofitting or otherwise modifying existing systems.
The helical scan transport apparatus of the invention includes a chassis having a front end portion and a rear end portion. An elevator assembly is mounted on the chassis at the front end. The elevator assembly is configured to receive a tape cartridge and to position the tape cartridge in a loaded position. A take-up reel assembly is coupled to the chassis at the rear end portion. A helical deck is mounted on a central portion of the chassis between the elevator assembly and the take-up reel assembly. The helical deck includes a rotary read/write head, a substantially linear tape loading path between the elevator assembly and the take-up reel assembly, and movable guides for seizing the tape from the tape loading path and for at least partially wrapping the tape around the rotary head. A linear threading mechanism is configured to grasp the leader block of the tape, thread the tape through the tape loading path of the helical deck, and couple the leader block to the take-up reel assembly.
In the preferred embodiment, the helical deck is taken from a commercially available Panasonic Model D350 digital video cassette recorder. Also in the preferred embodiment, the helical transport is dimensioned to fit within a rectangular enclosure measuring approximately 12.5″ (inches) wide by 26.5″ deep and configured such that a plurality of the transport apparatuses may be stacked within the enclosure with a vertical spacing of 11.06″ on center. The front end portion of the chassis extends 7.0″ outward from the enclosure and is configured to mate with the 4400 automated cartridge system when the enclosure is coupled to a housing of the 4400 automated cartridge system.
The rectangular enclosure is a frame assembly configured to enclose up to four of the helical transports of the invention. The enclosure measures 26.5″ inches deep by 28.0 inches wide by 67.775 inches high (not including castors). The enclosure houses each transport and its associated electronic circuitry in a side-by-side arrangement. The transport fills approximately 12.3″ of the width and the remaining width is available for a power supply and the electronic circuitry associated with the transport.
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a Storage Technology Corporation Automated Cartridge System (ACS).
FIG. 2 is a top cross-sectional view of the Automated Cartridge System of FIG. 1 .
FIG. 3 is a perspective view of a cartridge drive unit of the invention.
FIG. 4 is a top view of a cartridge drive unit of the invention illustrating a helical transport and its associated electronics mounted within the frame assembly.
FIG. 5 is a front view of a cartridge drive unit of the invention illustrating four helical transports mounted within the frame assembly.
FIG. 6 is a perspective view of the helical transport of the invention.
FIG. 7 is a top view of the helical transport of the invention.
FIG. 8 is a top view of the helical transport of the invention with the linear tape threading mechanism removed.
FIG. 9 is a right side view of the helical transport of the invention.
FIG. 10 is a left side view of the helical transport of the invention.
FIG. 11 is a simplified top view of the helical transport of the invention illustrating the dimensions and pre-loading tape path.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention is discussed in detail below. While specific part numbers and configurations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the art will recognize that other components and configurations may be used without departing from the spirit and scope of the invention.
The invention is a helical scan transport for a magnetic tape cartridge. The transport has a substantially linear tape loading path and a form factor which allows its use with a Storage Technology Corporation Model 4400 automated cartridge system or ACS. The transport is dimensioned to fit within a rectangular enclosure (i.e., a cartridge drive unit) measuring approximately 28″ wide by 26.5″ deep and configured such that a plurality of the transports may be stacked within the enclosure with a vertical spacing of 11.06″ on center. The transport itself is 12.3″ wide. The additional space is used for the associated electronic circuitry. The transport includes a front end portion (for receiving a helical data cartridge) which extends outward 7″ from the enclosure. The front end portion of the transport is configured to mate with the 4400 automated cartridge system when the enclosure is coupled to a housing of the 4400 automated cartridge system.
The inventors have discovered that the costs involved with developing a helical scan transport for a single reel cartridge are prohibitive. Development of the required head assembly, servo controls, and data path (i.e., read/write electronics between the head assembly and the input/output data channels) are extremely high. This may account for the fact that such a device is not commercially available. In overcoming this problem, the inventors have further discovered that a double reel cassette type helical scan video transport could be adapted to produce a single reel cartridge transport which meets the required form factor for use with a 4400 ACS. By using the head assembly, the servo controls and the data path from the video transport, development costs were minimized and time to market was greatly reduced. The resulting helical scan transport allows the storage capacity of the 4400 ACS to be increased from approximately 1.2 terabytes to approximately 150 terabytes. This is over a 100 times increase in storage capacity without requiring modification to the 4400 ACS.
A new helical scan tape cartridge was developed for use with the transport of the invention. The helical cartridge has a form factor similar to the 3480 cartridge. Thus, the 4400 ACS can store both helical cartridges and 3480 cartridges. By producing a helical scan transport and helical cartridge which are compatible with existing automated cartridge systems, the data storage capacity of existing systems can be vastly increased without the need for retrofitting or otherwise modifying existing systems.
In addition, the new helical transport and helical cartridge can coexist in a 4400 ACS environment with the 4480 transport (and other Model 4400 ACS compatible longitudinal-format transports) and the 3480 cartridge. The helical cartridges bear identification marking so that the 4400 ACS can distinguish a helical cartridge from a 3480 cartridge and route each cartridge to an appropriate transport.
The helical transport of the invention is now described with reference to the figures. The 4400 ACS is indicated in FIG. 1 by reference number 100 . ACS 100 includes a housing 102 . Housing 102 is a substantially circular shaped housing having twelve substantially flat sides. Each side is approximately 36 inches wide. The overall housing 102 is approximately 128 inches in diameter and 92 inches high. For a more detailed discussion of the 4400 ACS, see U.S. Pat. Nos. 4,864,511, 4,928,245, and 4,932,826 to Moy et al. The full text of each of the '511, '245, and '826 patents is hereby incorporated by reference. As described in these patents, housing 102 encloses a robot assembly and a plurality of data cartridge storage cells or bins 118 (see FIG. 2 ).
Coupled to a side of housing 102 is a cartridge drive assembly 200 . Cartridge drive assembly 200 includes a frame assembly 202 for housing a plurality (e.g., four) of helical cartridge transports 204 (not shown in FIG. 1 ). Cartridge drive unit 200 mates with a side of housing 102 via a drive opening 108 . Drive opening 108 is a substantially rectangular recess approximately 50 inches high by 16 inches wide by 7 inches deep. A rear wall of opening 108 forms a template 110 . Template 110 includes a plurality of cassette openings 114 and locating holes 116 .
Template 110 is configured to mate with each transport 204 so that cartridge opening 114 mates with a front face 206 of cartridge transport 204 and a cartridge may be passed through opening 114 and into an elevator assembly 208 (see FIG. 6 ). Locating holes 116 are configured to mate with alignment pins 210 (see FIG. 3) of cartridge transport 204 .
FIG. 2 is a cross-sectional top view of ACS 100 showing ACS housing 102 and cartridge drive unit 200 . Cartridge transport 204 is illustrated within cartridge drive unit 200 . A plurality of cartridge storage bins 118 within housing 102 are also depicted.
FIG. 3 is a perspective view of cartridge drive unit 200 with the side and top panels removed from frame assembly 202 . Four cartridge transports 204 are shown mounted within frame assembly 202 . Note that front face 206 of each cartridge transport 204 is covered by a dust cover 213 which includes an opening 214 configured to accept passage of a tape cartridge into elevator assembly 208 . Frame assembly 202 is configured to accept mounting of one, two, three or four cartridge transports 204 .
Note that transports 204 extend out from the front face of cartridge drive unit 200 for mating with template 110 of ACS 100 . Note also that transports 204 are located to the right side of frame assembly 202 . Much of the electronic circuitry for each transport 204 is positioned in frame assembly 202 to the left side of each transport 204 in an electronics area 211 . This is further illustrated in FIGS. 4 and 5.
FIG. 4 is a cross-sectional top view and FIG. 5 is a front view of cartridge drive unit 200 . Cartridge drive unit 200 is 26.5″ deep by 28″ wide by 67.8″ high (not including casters). Cartridge drive unit 200 is configured to mate with ACS housing 102 without physically interfering with other ACS subsystems which may be part of or coupled to housing 102 . These include slave ACS's, additional cartridge drives, control units, and access doors.
In order for the helical transport 202 of the invention to be compatible with cartridge drive unit 200 and ACS 100 , transport 202 must fit within frame assembly 204 . Front end 212 of transport 202 must extend approximately 7″ out from frame assembly 202 . In addition, the height of each transport 204 must be limited so that a vertical distance of 11.08″ inches is maintained between alignment pins 210 of adjacently stacked transports 204 . This will allow the front faces 206 of the transports 204 to precisely mate with the cartridge openings 114 and locating holes 116 in drive opening 108 of ACS housing 102 .
The helical scan transport of the invention is now described in detail with reference to FIGS. 6-10. FIG. 6 is a perspective view, FIG. 7 is a top view, FIG. 9 is a right side view, and FIG. 10 is a left side view of helical scan transport 204 . FIG. 8 is a top view of transport 200 with linear threading mechanism 218 removed. Transport 200 includes an elevator assembly 208 , a helical deck 216 , a take-up reel 236 , a linear threading mechanism 218 , a circuit card area 220 , and a transport chassis 234 . Elevator assembly 208 is configured to receive a tape cartridge and to load the cartridge into transport 204 . Helical deck 216 includes a rotary scan head 222 , a loading ring 224 , and a plurality of guide posts and capstans which make up a tape path (discussed below).
Linear threading mechanism 218 includes a linear bearing 226 , a threading arm 228 , and a threading cam 230 . Linear threading mechanism 218 is described in detail in commonly owned, co-pending U.S. Pat. No. 5,333,810, filed concurrently herewith, titled “Raised Linear Threading Mechanism for a Tape Transport System,” and naming as inventors David T. Hoge and John C. Owens, which is incorporated herein by reference. Similarly, the servo-control of linear threading mechanism 218 is described in detail in commonly owned, co-pending U.S. Pat. No. 5,325,028, titled “System and Method for Magnetic Tape Leader Block Extraction,” and naming as inventor Bruce McWilliams Davis, which is incorporated herein by reference.
Circuit board area 220 includes a plurality of D-type printed circuit board connectors for connecting to a plurality of printed circuit board containing electronic circuitry for transport 204 . An opening 232 in chassis 234 is configured to accept mounting of a muffin fan for cooling the electronic circuitry of transport 204 .
As discussed above, designing and developing a helical deck such as helical deck 216 is an expensive and time consuming process. Helical deck 216 includes a tape path and associated guides, a supply reel drive assembly (not shown), a take-up reel assembly, and all associated servo control circuitry. Helical deck 216 further includes complex electronic circuitry associated with the read/write data path. In order to bypass the expense and difficulties in developing a custom helical deck, the inventors have taken helical deck 216 from a commercially available device and adapted it for use in helical transport 204 .
In the preferred embodiment of the invention, helical deck 216 is taken from an AJ-D350 ½″ digital studio video tape recorder available from Panasonic Broadcasts Systems Co., Secaucus, N.J. The Panasonic D350 is a video tape recorder configured to be used with ½″ video cassettes. It will not accept a 3480 tape cartridge. Accordingly, the inventors have taken only the helical deck (including the read/write electronics, data path, servo controls and motors, and the associated electronic circuitry) from the Panasonic D350. For a detailed technical discussion of the D350, see John Watkinson, The D -3 Digital Video Recorder, Focal Press, 1992, which is incorporated herein by reference.
Essentially, the inventors have produced a transport configuration which will allow the D350 deck to be used with a tape cartridge while maintaining a form factor compatible with the Storage Technology Corporation Model 4400 ACS. A cartridge loading mechanism (elevator assembly 208 ) and a tape threading mechanism (linear threading mechanism 218 ) work together in providing the tape to helical deck 216 in a format such that helical deck 216 “sees” a cassette. Once the tape is pre-loaded through the tape path by linear threading mechanism 218 , tape control can then be turned over to the D350 helical deck.
Because the Panasonic D350 helical deck was designed to work with a tape cassette, the servo controls were designed to feed tape from a supply reel of a cassette in a counter-clockwise direction and to wind the tape on a take up reel (within the cassette), also in a clockwise direction. The standard 3480 cartridge, however, requires that the supply reel be turned in a counter clockwise direction to feed the tape. Accordingly, in order to use the servo control circuits and motors of the Panasonic D350, a new tape cartridge had to be developed.
The new helical cartridge has essentially the same dimensions and features as the 3480 cartridge. However, the helical cartridge feeds tape from the take-up reel when it is turned in a clockwise direction. Thus, the tape feeds from a front, left-side corner of the cartridge rather than a front, right-side corner as in the 3480 cartridge. Since the dimensions and other features of the helical cartridge are substantially the same as the 3480 cartridge, the helical cartridge may be used in the Model 4400 ACS. The helical cartridge is detailed in co-pending and commonly owned U.S. patent application Ser. No. 07/870,576, filed on Apr. 17, 1992, and titled “Magnetic Tape Cartridge for Helical Scan Transport,” which is incorporated herein by reference.
The 3480 cartridge and the new helical cartridge have the same essential dimensions and features. Therefore, they are hereafter referred to as “3480-style” cartridges.
The new cartridge will bear identification markings so that ACS 100 can distinguish the helical cartridges from the 3480 cartridges and route each cartridge to an appropriate transport. Thus, helical transport 204 may coexist in an ACS 100 environment with other transports (e.g., the Storage Technology Corporation 4480).
In order to meet the conflicting requirements of producing a helical transport (1) with a form factor compatible with ACS 100, (2) which uses a tape cartridge compatible with ACS 100 (i.e., can be stored in bins 118 and manipulated by a robot mechanism of the ACS); and (3) which uses a commercially available helical deck; the components of helical transport 204 were configured and arranged as illustrated in FIGS. 7-10. The dimensions of the preferred embodiment are shown in FIG. 11 .
Note that the motor which drives the supply reel of the tape cartridge has been relocated off of helical deck 216 to a position beneath elevator assembly 208 at the front of transport 204 . Similarly, the motor which drives take-up reel 236 has been moved off of helical deck 216 to a position to the rear of helical transport 204 . It is this arrangement which provides a substantially linear tape pre-load path to linear threading mechanism 218 and allows helical transport 204 to meet the form factor requirements of ACS 100 .
FIG. 11 also illustrates the tape path 338 . During the pre-load operation performed by linear threading mechanism 218 , the leader block of the tape is pulled under guide post A; over guide posts B, C, D, E, F and G; under guide post H; and into take-up reel 236 . Guide posts A and H are fixed position guide posts of helical deck 216 . Guide posts E and F are mounted on loading ring 224 and move therewith to load the tape around helical head 222 for data read/write operations. Guide post G is part of the incline post assembly of helical deck 216 . Guide post D is a fixed post added by the inventors. It is not part of the Panasonic D350 helical deck.
As discussed above, once the pre-load operation is complete, tape control can be turned over to helical deck 216 . Helical deck 216 may then load the tape around head 222 as is known in the art.
The transport of the invention has been described in the environment of a Storage Technology Corporation Model 4400 ACS. It will be apparent to a person skilled in the art, however, that the transport of the invention may be used with other automated cartridge systems. These include the Storage Technology Corporation WOLFCREEK™ ACS, the Storage Technology Corporation POWDERHORN™ ACS, and the 3495 ACS available from IBM Corporation, Armonk, N.Y. Each of these ACS's currently store data in a longitudinal recording format on a 3480 cartridge. Moreover, the transport of the invention may be used with any single reel tape cartridge and is not limited to the 3480-style cartridge.
While the invention has been particularly shown and described with reference to several 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 in the appended claims.
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A helical scan transport apparatus for reading and writing data on to a magnetic recording tape which is wound on a supply reel rotatably mounted within a removable tape cartridge includes a chassis having a front end portion and rear end portion. An elevator assembly is mounted on the chassis at the front end. The elevator assembly is configured to receive the tape cartridge and to position the tape cartridge in a loaded position. A take-up reel assembly is coupled to the chassis at the rear end position. A helical deck is mounted on a central portion of the chassis between the elevator assembly and the take-up reel assembly. The helical deck includes a rotary read/write head, a substantially linear tape loading path between the elevator assembly and the take-up reel assembly, and a movable guide for the seizing the tape from the tape loading path and for at least partially wrapping the tape around the rotary head. A linear threading mechanism is configured to grasp the leader block of the tape, thread the tape through the tape loading path of the helical deck, and couple the leader block to the take-up reel assembly. The helical transport has a form factor compatible with the Storage Technology Corporation Model 4400 Automated Cartridge System.
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FIELD OF TECHNOLOGY
[0001] The present invention relates to a process for preparing diamond, graphite or mixtures of diamond and graphite from CO or CO 2 served as the carbon source by reduction with active metals.
BACKGROUND OF TECHNOLOGY
[0002] Diamond has the advantages of high melting point, low compressibility coefficient, high symmetry and high refractive index. It has wide applications in industrial manufacture and scientific research. Owing to the specific properties and uses thereof, quite long ago, people tried to prepare it by chemical method in order to supplement the insufficiency of the natural storage. A large amount of time and a long course of events have been spent on solving a series of problems such as the exploration of transition condition and relevant facilities as well as searches for an effective catalyst. In 1954, first work on successful preparation of diamond by conversion of graphite under strict control of high temperature and high pressure with FeS used as the flux was reported in Nature, Vol. 176, 51. Thereafter research and production of man-made diamond have been developing rapidly and grows to be a new industry. The conventional method of preparation for diamond involves the use of graphite as the raw material, molten metals (Ni, Cr, Mn, Fe, Co, Ti, Al etc) as the catalyst and flux, little diamond particles as crystal seeds. Thus graphite is converted into diamond under pressure of 5-100 kbar and high temperature of 1200-2400K. This kind of method has to endure critical conditions and very high cost.
[0003] Chinese patent 97119450.5 and Science, 1998, Vol. 281, 246 disclosed a method in which CCl 4 was used as the carbon source, Na was used as the reducing agent and solvent, Ni—Co metal was used as the catalyst. CCl 4 could be converted into diamond at 700° C. The size of the diamond particles thus prepared was less than 0.2 micrometer and the method had the danger of explosion. Therefore at the moment, the method is not suitable for large-scale industrial production of diamond.
[0004] On the other side, the global storage of CO 2 on earth is extremely abundant. CO 2 is also the by-product of exhaust emission of many industrial manufactures. When CO 2 is expelled into air, “greenhouse effect” will be induced which will cause the global weather getting warmer. As a result, many countries in the world have to spend huge amount of manpower and resources to bring it under control. CO 2 is non-toxic and cheap. Utilization of CO 2 as main raw material for synthesizing inorganic and organic compounds is one of the objectives of chemists. It is regrettable to notice that up to now no any well-industrialized method of treatment that uses CO 2 as raw material in huge amount has been reported.
[0000] Content of Technology
[0005] The objective of the present invention is to provide a method for the preparation of diamond, graphite or mixtures of diamond and graphite by using CO 2 (or compound that could release CO 2 on decomposition) or CO (or CO source) as the carbon source and active metals as the reducing agents.
[0006] In order to realize the above-mentioned objective, the inventor of present invention carried out a large amount of intensive investigations and found that CO 2 or CO 2 source and CO or CO source could react with active metal that is capable of reducing them into elementary carbon to form diamond, graphite or mixture of diamond and graphite.
[0007] Hence the present invention provides a method for preparing diamond, graphite or mixture of diamond and graphite. The method includes the steps in which active metals (capable of reducing carbon source into elementary carbon) under reducing conditions capable of reducing carbon source into elementary carbon are brought in contact with carbon source (CO and/or CO source and/or CO 2 and/or CO 2 source) to start a reduction reaction. The carbon source is preferably CO 2 and/or CO 2 source.
[0008] In the method of the present invention based on a preferred approach, CO 2 is used as the carbon source and is reduced by active metal to form diamond. Therefore any compound, such as dry ice, oxalates, carbonates or their mixture that could release CO 2 on decomposition as well as CO 2 itself could be used as a carbon source to prepare diamond.
[0009] Any metal that is capable of reducing CO or CO 2 into elementary carbon could be used as an active metal in the present invention. Metals whose standard electrode potentials are lower than −2.2 V are preferred. Such metals include (but not limited to) one or mixture of several of the following: metal Na, Li, K, Rb, Cs, or Mg, Ca, Sr, Ba. Although not wished to be bound by any theory, it is generally believed that standard electrode potential of CO 2 /CO 2 . − in aprotic solvent is −2.2 V. CO 2 . − is an active single electron free radical that reacts easily with CO 2 to form C—C linkage. Therefore those metals having standard electrode potential lower than −2.2 V, such as the standard electrode potential of Na is −2.7 V, the standard electrode potential of K is −2.931 V, the standard electrode potential of Li is −3.04 V, the standard electrode potential of Mg is −2.37 V, could all be used to reduce CO 2 to prepare diamond or mixtures of diamond and graphite. Temperature of reduction reaction suitable to be used in the present invention is preferably 300° C. at least, preferably 300-2000° C. Specific temperature of reaction to be adopted would depend on the selected pressure condition and the selected active metal used. When metal Na or Li, K, Rb, Cs is used as reducing metal, reaction temperature is preferably 300° C. at least, more preferably 300-2000° C.; When Mg, Ca, Sr, Ba is used as reducing metal, reaction temperature is preferably 650° C. at least, more preferably 650-2000° C.;
[0010] Pressure of reduction reaction suitable to be used in the present invention is 0.2 kbar at least, preferably 0.2-5.0 kbar. Specific pressure of reaction to be adopted would depend on what kind of elementary carbon product expected to be prepared and on the temperature selected. It should be emphasized that when diamond of high purity is expected to be synthesized, higher pressure is preferably adopted, more preferably higher pressure is maintained throughout the whole course of reaction.
[0011] Under higher pressure, the product obtained is diamond with high density; If the reaction is carried out in a reaction kettle that could not maintain higher pressure automatically, pressure of the system will drop in the course of reaction and the main product formed at that time will be graphite of lower density and the final product will be a mixture of graphite and diamond. Under higher temperature and higher pressure, said reaction route is as follows;
3CO 2+4 M=C (diamond, graphite or mixture of graphite and diamond)+2M 2 CO 3 (M=Li or Na, K, Rb, Cs)
3CO 2+2 N═C (diamond, graphite or mixture of graphite and diamond)+2NCO 3 (N==Mg or Ca, Sr, Ba)
[0012] The thermodynamic property of diamond determines that a definite pressure is necessary for the formation of diamond. The higher the pressure is, the more favorable the formation of diamond will be. In the method of the present invention, it is possible to vary the pressure of the reaction system by controlling the amounts of dry ice, oxalate, carbonate or CO 2 gas added. Experiments prove that when temperature is lower than 300° C. and pressure is lower than 0.2 kbar, no diamond will be formed. Judging the tolerance of the common reaction kettle, it is appropriate to carry out the reaction at a temperature of 300-2000° C. and a pressure of 0.2-5.0 kbar.
[0013] Reduction reaction of the present invention is preferably carried out under a supercritical condition. It is believed that when CO 2 is heated to exceed its critical point (for example, 31.5° C., 73 kbar), its gas phase and liquid phase will turn into a single supercritical phase having high mixing rate and relatively weaker intermolecular association power. This will induce the supercritical CO 2 to possess high reactivity. Many physico-chemical properties of the supercritical CO 2 lie between gas and liquid and possess the advantages of both two. For instance, it possesses dissolution power and heat conductivity coefficient similar to liquid and viscosity coefficient and diffusion coefficient similar to gas. In the preferred approach of the present invention, temperature and pressure are adjusted to turn the CO 2 of the reaction system into supercritical state.
[0014] Based on the method of the present invention, time of the reduction reaction is determined by temperature, pressure and reducing power of the reducing metal adopted. 10-48 hours are preferred.
[0015] After the completion of the reaction, the reaction system is cooled to room temperature, and pressure is lowered to atmospheric pressure and diamond, graphite or their mixture could be obtained.
[0016] If small diamond granule, such as 300 μm-sized diamond granule, is added to the above-mentioned reaction system as a crystal seed, up to 6000 μm-sized diamond granule could be obtained. For the sake of convenience and lowering cost, reaction product of the preceding experiment is preferably selected as the crystal seed.
[0017] In order to obtain pure diamond, diamond or mixture of diamond and graphite obtained by the method of the present invention could be purified by any conventional purification method. For instance, it is possible to obtain pure diamond particulate through intensive heat treatment with perchloric acid or sedimentation separation with 0.5% aqueous solution of gum Arabic.
[0018] If only graphite is to be prepared, reaction could be carried out merely at pressure lower than 0.2 kbar.
[0019] The present invention utilizes industrial by-product CO 2 or CO or compounds capable of releasing CO or CO 2 on decomposition as the main raw material and thus possesses the advantages of low reaction temperature, good dispersion and good flowability of carbon source. Diamond crystals obtained have good crystallinity, contains no impurities and could have size up to several hundred micrometers. If small diamond granule, such as 300 μm-sized diamond granule, is added to the above-mentioned reaction system as a crystal seed, diamond granule with size of 3000 μm or even up to 6000 μm could be obtained.
[0020] Especially when CO 2 is used as the carbon source, the approach has the following advantages: CO 2 is the by-product of exhaust emission of many industrial manufactures. When CO 2 is expelled into air, “greenhouse effect” will be induced which will cause the global weather getting warmer. As a result, many countries in the world have to spend huge amount of manpower and resources to bring it under control. The present invention uses CO 2 as the raw material to prepare diamond, graphite or their mixture. Thus this approach not only could turn wastes into valuables and could perform it at low cost but also it is beneficial to the improvement of environment and thus possesses good social benefit and economic benefit. The present invention could also be used to reduce CO 2 into graphite that is also an important industrial raw material. Using CO 2 as a reactant has advantages of non-toxicity, non-combustion and safe handling. In addition, CO 2 could easily be separated from the reactant and thus by lowering the pressure, CO 2 turns into gas and then is expelled and the final product could conveniently and directly be obtained. In comparison with the conventional method of preparation for diamond, the present method uses lower temperature, pressure, simpler facility and is of low cost and easily manipulative. When compared with method of reduction of CCl 4 into diamond, the present method is safer in manipulation, could yield diamond of larger size and thus possesses significance of practical industrial production and potential wide markets.
BRIEF DESCRIPTION OF THE DRAWING
[0021] FIG. 1 is the X-ray diffraction profile for the sample obtained in Example 1.
[0022] FIG. 2 is the Raman spectrum for the sample obtained in Example 1.
[0023] FIG. 3 a , 3 b are SEM (scanning electronic micrograph) profiles for the diamond sample obtained in Example 1. FIG. 3 b is a magnified profile for the portion selected by the square in FIG. 3 a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
EXAMPLE 1
[0024] 2.0 g of metal sodium of chemical pure grade and 8.0 g of self-prepared dry ice were put into an autoclave of a capacity of 12 mL. The autoclave was heated to 440° C. so that the pressure in the autoclave reached 500-1000 kbar and this state was maintained for 16 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.20 g of black powder was obtained.
[0025] The X-ray diffraction spectrum of the sample was measured. In the diffraction spectrum ( FIG. 1 ) of the sample obtained, there appeared 3 characteristic diffraction peaks of cubic phase diamond (JCPDS card No. 6-675) and 1 rather broad diffraction peak of graphite at 26.2°.
[0026] Raman spectrum of the sample was measured. In the spectrum, there was a characteristic peak of diamond at 1332 cm −1 ( FIG. 2 , 1332 cm −1 is the characteristic peak of diamond, see Nature 1999 , Vol. 402, 164) with its half-height width of 4.7 cm −1 close to that of natural diamond (2.5 cm −1 ), which indicating that the diamond synthesized has good crystallinity. In addition there were two characteristic peaks of graphite at 1363 cm −1 and 1591 cm −1 respectively indicating that the product was a mixture of diamond and graphite.
[0027] The mixed powder obtained was intensively heat-treated with perchloric acid at 160° C. and 0.018 g of pure diamond granule was finally obtained. SEM micrograph indicated that the average diameter of the diamond granule was 100 μm ( FIG. 3 ).
[0028] If the metal sodium of the present example was replaced by Li, K, Rb, Cs as the reducing metal, mixtures of diamond and graphite were similarly obtained.
EXAMPLE 2
[0029] 2.5 g of potassium of chemical pure grade was put into an autoclave. Said autoclave was heated to 470° C. and CO 2 gas was fed into an autoclave under pressure to 400-1500 kbar and this state was maintained for 12 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.22 g of black powder was obtained.
[0030] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0031] The mixed powder obtained was separated by sedimentation in 0.5% aqueous solution of gum Arabic and 0.02 g of pure diamond granule was finally obtained. SEM micrograph indicated that the average diameter of the diamond granule was 120 μm and the maximum diameter could reach 300 μm.
[0032] If potassium of the present example was replaced by Li, Na, Rb, Cs as the reducing metal, mixture of diamond and graphite was similarly obtained.
EXAMPLE 3
[0033] 2.2 g of potassium of chemical pure grade and 6.0 g of MgCO 3 were put into an autoclave of 12 mL that was heated to 500° C. and to a pressure of 800-2000 kbar and this state was maintained for 18 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. 0.08 g of black powder was obtained.
[0034] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0035] The mixed powder obtained was intensively heat treated with perchloric acid and pure diamond granule with average diameter of the diamond granule of 260 μm (determined by SEM) was obtained.
[0036] If potassium of the present example was replaced by Li, Na, Rb, Cs as the reducing metal, mixtures of diamond and graphite were similarly obtained.
[0037] If MgCO 3 of the present example was replaced by Ag 2 CO 3 , CaCO 3 , CdCO 3 , CoCO 3 , CuCO 3 ,FeCO 3 , BaCO 3 , MnCO 3 , NiCO 3 , PbCO 3 , SrCO 3 , ZnCO 3 , Na 2 CO 3 , K 2 CO 3 , Li 2 CO 3 and the temperature was changed to 470° C., 950° C., 500° C., 450° C., 480° C., 520° C., 1000° C., 460° C., 550° C., 540° C., 900° C., 440° C., 1500° C., 1400° C., 750° C. respectively, a mixture of diamond and graphite was similarly obtained.
EXAMPLE 4
[0038] 2.2 g of Li of chemical pure grade and 14.0 g of NiC 2 O 4 were put into an autoclave of 12 mL which was heated to 560° C. and to a pressure of 500-1000 kbar and this state was maintained for 12 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.28 g of black powder was obtained.
[0039] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0040] The mixed powder obtained was intensively heat treated with perchloric acid at 160° C. and pure diamond granule with average diameter of the diamond granule of 100 μm (determined by SEM) was obtained.
[0041] If Li of the present example was replaced by K, Na, Rb, Cs as the reducing metal, a mixture of diamond and graphite was similarly obtained.
[0042] If NiC 2 O 4 of the present example was replaced by CaC 2 O 4 , CdC 2 O 4 , CoC 2 O 4 , CuC 2 O 4 , CrC 2 O 4 , FeC 2 O 4 , K 2 C 2 O 4 , MnC 2 O 4 , La 2 (C 2 O 4 ) 3 , Li 2 C 2 O 4 , MgC 2 O 4 , Na 2 C 2 O 4 , PbC 2 O 4 , SrC 2 O 4 , ZnC 2 O 4 , La 2 (C 2 O 4 ) 3 , Cr 2 (C 2 O 4 ) 3 , a mixture of diamond and graphite was similarly obtained.
EXAMPLE 5
[0043] 2.5 g of Mg of chemical pure grade was put into an autoclave of 12 mL. The autoclave was heated to 650° C. and CO 2 gas was fed into an autoclave under pressure to 500-1500 kbar and this state was maintained for 12 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.23 g of black powder was obtained.
[0044] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0045] The mixed powder obtained was intensively heat treated with perchloric acid and a pure diamond granule was finally obtained. SEM micrograph indicated that the average diameter of the diamond granule was 60 μm.
[0046] If Mg of the present example was replaced by Ca, Sr, Ba as the reducing metal and temperature was changed to 850° C., 800° C. and 750° C. respectively, mixture of diamond and graphite was similarly obtained.
EXAMPLE 6
[0047] 2.5 g of Ca of chemical pure grade and 8.0 g of self-prepared dry ice were put into an autoclave of capacity of 12 mL. The autoclave was heated to 850° C. so that the pressure in the autoclave reached 500-1000 kbar and this state was maintained for 16 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.20 g of black powder was obtained.
[0048] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0049] The mixed powder obtained was intensively heat treated with perchloric acid and pure diamond granule was finally obtained. SEM micrograph indicated that the average diameter of the diamond granule was 130 μm.
[0050] If Mg of the present example was replaced by Ca, Sr, Ba as the reducing metal and temperature was changed to 850° C., 800° C. and 750° C. respectively, mixture of diamond and graphite was similarly obtained.
EXAMPLE 7
[0051] 2.0 g of Mg of chemical pure grade and 14.0 g of CoC 2 O 4 were put into an autoclave of 12 mL which was heated to 650° C. and to a pressure of 500-1000 kbar and this state was maintained for 16 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.20 g of black powder was obtained.
[0052] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0053] The mixed powder obtained was intensively heat treated with perchloric acid and pure diamond granule with average diameter of the diamond granule of 50 μm (determined by SEM) was obtained.
[0054] If Mg of the present example was replaced by Ca, Sr, Ba as the reducing metal and the temperature was changed to 850° C., 750° C., 800° C., mixture of diamond and graphite was similarly obtained.
[0055] If CoC 2 O 4 of the present example was replaced by CaC 2 O 4 , CdC 2 O 4 , NiC 2 O 4 , CuC 2 O 4 , CrC 2 O 4 , FeC 2 O 4 , K 2 C 2 O 4 , MnC 2 O 4 , La 2 (C 2 O 4 ) 3 , Li 2 C 2 O 4 , MgC 2 O 4 , Na 2 C 2 O 4 , PbC 2 O 4 , SrC 2 O 4 , ZnC 2 O 4 , mixture of diamond and graphite was similarly obtained.
EXAMPLE 8
[0056] 3.5 g of Sr of chemical pure grade and 16.0 g of FeCO 3 were put into an autoclave of 12 mL which was heated to 800° C. and to a pressure of 500-1500 kbar and this state was maintained for 16 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.28 g of black powder was obtained.
[0057] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0058] The mixed powder obtained was intensively heat treated with perchloric acid and pure diamond granule with average diameter of the diamond granule of 100 μm (determined by SEM) was obtained.
[0059] If Sr of the present example was replaced by Ca, Mg, Ba as the reducing metal and the temperature was changed to 850° C., 650° C., 800° C., mixture of diamond and graphite was similarly obtained.
[0060] If FeCO 3 of the present example was replaced by CaCO 3 , CdCO 3 , CoCO 3 , CuCO 3 , Mg CO 3 , BaCO 3 , MnCO 3 , NiCO 3 , PbCO 3 , SrCO 3 , ZnCO 3 , Na 2 CO 3 , K 2 CO 3 , Li 2 CO 3 and the temperature was changed to 950° C., 820° C., 840° C., 880° C., 860° C., 1000° C., 860° C., 850° C., 840° C., 900° C., 940° C., 1500° C., 1400° C., 850° C., mixture of diamond and graphite was similarly obtained.
EXAMPLE 9
[0061] 2.2 g of K of chemical pure grade was put into an autoclave and a diamond seed of size of 300 μm was added. The autoclave was heated to 520° C. and CO 2 gas was fed into autoclave under pressure to 500-1500 kbar and this state was maintained for 16 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.24 g of black powder was obtained.
[0062] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0063] The mixed powder obtained was intensively heat treated with perchloric acid and a pure diamond granule was finally obtained. SEM micrograph indicated that the average diameter of the diamond granule was 430 μm.
[0064] If K of the present example was replaced by Li, Na, Rb, Cs as the reducing metal, mixture of diamond and graphite was similarly obtained.
EXAMPLE 10
[0065] 3.2 g of Cs of chemical pure grade and 8.0 g of self-prepared dry ice were put into an autoclave of a capacity of 12 mL and a diamond seed of 300 μm was also added. After the autoclave was heated to 300° C., CO 2 gas was fed under pressure, so that the pressure in the autoclave reached 200-1500 kbar and this state was maintained for 16 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.12 g of black powder was obtained.
[0066] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0067] The mixed powder obtained was intensively heat treated with perchloric acid and a pure diamond granule was finally obtained. SEM micrograph indicated that the average diameter of the diamond granule was 300 μm.
[0068] If Cs of the present example was replaced by Li, Na, Rb, K as the reducing metal and temperature was changed to 450° C., 520° C., 480° C. and 580° C. respectively, mixture of diamond and graphite was similarly obtained.
EXAMPLE 11
[0069] 2.2 g of potassium of chemical pure grade, 6.0 g of MgCO 3 and diamond seed of 300 μm were put into an autoclave of 12 mL which was heated to 500° C. and to a pressure of 800-1000 kbar and this state was maintained for 18 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.10 g of black powder was obtained.
[0070] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0071] The mixed powder obtained was intensively heat treated with perchloric acid and a diamond granule with average diameter of 270 μm (determined by SEM) was obtained.
[0072] If potassium of the present example was replaced by Li, Na, Rb, Cs as the reducing metal, mixture of diamond and graphite was similarly obtained.
[0073] If MgCO 3 of the present example was replaced by CaCO 3 , CdCO 3 , CoCO 3 , CuCO 3 , FeCO 3 , BaCO 3 , MnCO 3 , NiCO 3 , PbCO 3 , SrCO 3 , ZnCO 3 , Na 2 CO 3 , K 2 CO 3 , Li 2 CO 3 and the temperature was changed to 950° C., 500° C., 450° C., 480° C., 520° C., 1000° C., 460° C., 550° C., 540° C., 900° C., 440° C., 1500° C., 1400° C., 750° C. respectively, mixture of diamond and graphite was similarly obtained.
EXAMPLE 12
[0074] 2.2 g of Na of chemical pure grade, 16.0 g of NiC 2 O 4 and diamond seed of 300 μm were put into an autoclave of 12 mL which was heated to 480° C. and to a pressure of 500-1000 kbar and this state was maintained for 18 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.26 g of black powder was obtained.
[0075] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0076] The mixed powder obtained was intensively heat treated with perchloric acid and pure diamond granule with average diameter of the diamond granule of 360 μm was obtained.
[0077] If Na of the present example was replaced by Li, Na, Rb, Cs as the reducing metal, mixtures of diamond and graphite were similarly obtained.
[0078] If NiC 2 O 4 of the present example was replaced by CaC 2 O 4 , CdC 2 O 4 , CoC 2 O 4 , CuC 2 O 4 , CrC 2 O 4 , FeC 2 O 4 , K 2 C 2 O 4 , MnC 2 O 4 , La 2 (C 2 O 4 ) 3 , Li 2 C 2 O 4 , MgC 2 O 4 , Na 2 C 2 O 4 , PbC 2 O 4 , SrC 2 O 4 , ZnC 2 O 4 , mixture of diamond and graphite was similarly obtained. Oxalates that could release CO 2 on decomposition could also be used as the carbon source for producing a diamond.
EXAMPLE 13
[0079] 2.5 g of Mg of chemical pure grade and reaction product of Example 2 (used as a seed) were put into an autoclave. The autoclave was heated to 650° C. and CO 2 gas was fed into autoclave under pressure to 500-1500 kbar and this state was maintained for 12 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.24 g of black powder was obtained.
[0080] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0081] The mixed powder obtained was intensively heat treated with perchloric acid and pure diamond granule was finally obtained. SEM micrograph indicated that the average diameter of the diamond granule was 3200 μm.
[0082] If Mg in the present example was replaced by Ca, Sr, Ba as the reducing metal and the temperature was changed to 860° C., 840° C., 780° C., mixture of diamond and graphite was similarly obtained.
EXAMPLE 14
[0083] 2.0 g of Sr of chemical pure grade, 8.0 g of self-prepared dry ice and diamond seed of 300 μm were put into an autoclave of a capacity of 12 mL. The autoclave was heated to 800° C. so that the pressure in the autoclave reached 500-1000 kbar and this state was maintained for 16 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.21 g of black powder was obtained.
[0084] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0085] The mixed powder obtained was intensively heat treated with perchloric acid and pure diamond granule was finally obtained. SEM micrograph indicated that the average diameter of the diamond granule was 1100 μm.
[0086] If Sr of the present example was replaced by Ca, Mg, Ba as the reducing metal and temperature was changed to 880° C., 680° C. and 820° C. respectively, mixtures of diamond and graphite were similarly obtained.
EXAMPLE 15
[0087] 2.0 g of Mg of chemical pure grade, 14.0 g of FeC 2 O 4 and diamond seed of 300 μm were put into an autoclave of 12 mL which was heated to 700° C. and to a pressure of 500-1000 kbar and this state was maintained for 16 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.20 g of black powder was obtained.
[0088] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0089] The mixed powder obtained was intensively heat treated with perchloric acid and pure diamond granule with average diameter of 800 μm was obtained.
[0090] If Mg of the present example was replaced by Ca, Sr, Ba as the reducing metal and the temperature was changed to 860° C., 840° C., 780° C., mixture of diamond and graphite was similarly obtained.
[0091] If FeC 2 O 4 of the present example was replaced by CaC 2 O 4 , CdC 2 O 4 , CoC 2 O 4 , CuC 2 O 4 , CrC 2 O 4 , NiC 2 O 4 , K 2 C 2 O 4 , MnC 2 O 4 , La 2 (C 2 O 4 ) 3 , Li 2 C 2 O 4 , MgC 2 O 4 , Na 2 C 2 O 4 , PbC 2 O 4 , SrC 2 O 4 , ZnC 2 O 4 , mixture of diamond and graphite was similarly obtained.
EXAMPLE 16
[0092] 2.0 g of Ca of chemical pure grade, 16.0 g of FeCO 3 and diamond seed of 300 μm were put into an autoclave of 12 mL which was heated to 850° C. and to a pressure of 500-1000 kbar and this state was maintained for 16 hrs. Then the autoclave was cooled to room temperature and the pressure in the autoclave dropped to atmospheric pressure. The reaction product was treated with HCl and washed with water. 0.20 g of black powder was obtained.
[0093] X-ray diffraction pattern and Raman spectrum of the sample were measured and the obtained sample was proved to be a mixture of diamond and graphite.
[0094] The mixed powder obtained was intensively heat treated with perchloric acid and pure diamond granule with an average diameter of 1600 μm (determined by SEM) was obtained.
[0095] If Ca of the present example was replaced by Mg, Sr, Ba as the reducing metal and the temperature was changed to 660° C., 880° C., 820° C., mixtures of diamond and graphite were similarly obtained.
[0096] If FeCO 3 of the present example was replaced by CaCO 3 , CdCO 3 , CoCO 3 , CuCO 3 , MgCO 3 , BaCO 3 , MnCO 3 , NiCO 3 , PbCO 3 , SrCO 3 , ZnCO 3 , Na 2 CO 3 , K 2 CO 3 , Li 2 CO 3 and the temperature was changed to 950° C., 860° C., 870° C., 880° C., 920° C., 1000° C., 860° C., 950° C., 850° C., 900-C, 880° C., 1500° C., 1400° C., 850° C., respectively, mixture of diamond and graphite was similarly obtained.
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The present invention provides a method of preparation for diamond, graphite or mixtures of diamond and graphite by reduction of CO or CO 2 . Said method comprises a step of contacting an active metal capable of reducing a carbon source into elementary carbon with carbon source (such as CO and/or CO 2 and/or their origin) under conditions suitable to reduce the carbon source to elementary carbon in the course of a reduction reaction. After the raw diamond or mixtures of diamond and graphite thus obtained are subjected to intensive heat treatment with perchloric acid, pure diamond granules are obtained. The present method employs relatively low reaction temperature and pressure and the facilities needed in the method are simple and easy to operate. Diamond finally obtained has good crystallinity and free of impurities with granule size of several hundred micrometer. In addition, the present invention makes use of the industrial by-product of CO and CO 2 which not only turns wastes into valuables and is low in cost, but also improves the environment and thus possesses both good social benefits and economical benefits.
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FIELD OF INVENTION
[0001] This invention relates to a local area network (LAN), that is to say a high bandwidth computer network operating over a relatively small area, such as an office or group of offices.
BACKGROUND TO THE INVENTION
[0002] Typically, a LAN includes a plurality of access points hardwired together, the access points being positioned at appropriate positions in a building or group of offices. Each access point may act as a base station for wireless communication with a number of users of the LAN. For example, as shown in FIG. 1, one floor, indicated generally by the reference numeral 1 , of a building could be provided with nine access points 2 a to 2 i, the access points being interconnected by hardwiring 3 . Each of the access points 2 a to 2 i communicates with user workstations (not shown) using the Internet protocol.
[0003] The disadvantage of this type of LAN is that it is difficult to reconfigure to accommodate movement of users from one part of the floor to another, particularly where high-usage access points exist. Thus, if the access point 2 d is fully utilised, and a user moves into the vicinity of that access point (either from one of the other access points or as a new user), the LAN will not be able to accommodate such a user. In this connection, it will be appreciated that, although in theory such a new user could be accommodated, in that communication with the access points would be possible, in practice communication for that user (and all other users of that access point) would become intolerably slow. In such a case, it would be necessary to provide an additional access point, and to hardwire this additional access point into the existing hardwired network.
SUMMARY OF THE INVENTION
[0004] The present invention provides a LAN comprising a plurality of access points, each access point being provided with a first transceiver for wireless communication with one or more user workstations, wherein the access points are provided with second transceivers for wireless communication with one another, and wherein at least one of the access points is configured for movement to enable reconfiguration of the LAN.
[0005] In preferred embodiments, each of the access points will be configured for movement.
[0006] In a preferred embodiment, each access point configured for movement is provided with propulsion means for moving that access point to enable reconfiguration of the LAN.
[0007] Advantageously, each access point configured for movement is provided with a buoyancy device, the buoyancy devices being such that, in use, the access points can be positioned so as to float at predetermined heights. A respective helium balloon may constitute each of the buoyancy devices. Preferably, each of the helium balloons is such that its buoyancy substantially matches the combined mass of the associated access point and propulsion means.
[0008] Preferably, a respective electric motor and propeller constitute the propulsion means of each access point configured for movement.
[0009] Alternatively, the LAN may further comprise a tracking along which the access points can be propelled. Each access point configured for movement may be provided with a support wheel engageable with the tracking.
[0010] In a preferred embodiment each first transceiver is arranged to communicate with the or each associated user workstation using the Internet protocol. Preferably, the second transceivers are arranged to communicate with each other using the IEEE 802.11b, the IEEE 802.11a, or the HiperLAN/2 protocol.
[0011] In a further aspect, the invention provides an access point for a local area network comprising a first transceiver for wireless communication with one or more user workstations, a second transceiver for wireless communication with other access points, wherein the access points is configured for movement to enable reconfiguration of the local area network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention will now be described in greater detail, by way of example, with reference to the drawings, in which:
[0013] [0013]FIG. 1, as previously described, is a schematic view of a known form of LAN
[0014] [0014]FIG. 2 is a schematic view of a LAN constructed in accordance with the invention;
[0015] [0015]FIG. 3 is a schematic view of one of the access points of the LAN of FIG. 2;
[0016] [0016]FIG. 4 is a schematic representation of two access points of a modified form of LAN constructed in accordance with the invention;
[0017] [0017]FIG. 5 is a schematic representation of another modified form of LAN constructed in accordance with the invention; and
[0018] [0018]FIG. 6 is a schematic view of one of the access points of the LAN of FIG. 5.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] Referring to the drawings, FIG. 2 is a drawing of one floor, indicated generally by the reference numeral 11 , of a building provided with a LAN having nine access points 12 a to 12 i. As shown in FIG. 3, the access point 12 a includes a first and second transceivers 13 and 14 , respective antennas 13 a and 14 a associated therewith, and controller 15 . The remaining access points 12 b to 12 i are of similar construction. Each of the transceivers 13 is configured to use the Internet protocol, and each of the transceivers 14 is configured to use the IEEE802.11b protocol (which operates at 2.4 to 2.4835 GHz).
[0020] Each of the access points 12 a to 12 i communicates with one or more user workstations (not shown) in the vicinity thereof using its first transceiver 13 . The access points 12 a to 12 i communicate with one another using their second transceivers 14 .
[0021] It will be apparent that the LAN described above is considerably easier to reconfigure than the known LAN. Thus, as the access points 12 a to 12 i are not hardwired together, they can be moved around the floor of the building to accommodate different user configurations. Thus, if a group of users moves from one part of the floor served by a first access point to the vicinity of another access point which is already fully utilised, the first access point could be moved with the users, thereby maintaining good utilisation. Alternatively, an additional access point (not shown) could be installed to accommodate the new users. In either case, the reconfiguration is relatively simple, as there is no hardwiring to modify.
[0022] [0022]FIG. 4 includes two access points 22 a and 22 b of a modified form of the LAN of FIG. 2. Each of the access points 22 a and 22 b is attached to a respective helium balloon 23 , so that the access points can float in the air. Each access point 22 a and 22 b is also provided with a small electric motor 24 which can be used to power an associated propeller 25 . The buoyancy of each of the helium balloons 23 is such that it just matches the combined masses of the associated access point 22 a, 22 b and the associated motor 24 and propeller 25 . The access points 22 a and 22 b can, therefore, be positioned, for example, in the ceiling region of an open plan office for communication with respective groups of users.
[0023] The access points 22 a and 22 b are, apart from the provision of the balloons 23 , motors 24 and propellers 25 , identical to the access points 12 a to 12 i of the embodiment of FIG. 2, and so interact with one another and with the user groups in a similar manner. This embodiment has, however, an additional advantage in that an access point can more easily be moved from place to place. Control of the movement of the access points can be carried out from a central control station (not shown) under software control.
[0024] As an alternative to moving the access points using electric motors and propellers, they could be provided, instead, with air jets. It would also be possible to mount the access points on tracking provided within the ceiling region of a building. Thus, as shown in FIG. 5, a modified form of the LAN of FIG. 2 is provided in a floor, indicated generally by the reference numeral 31 , of a building. The LAN has nine access points 32 a to 32 i, each of which is moveable along a tracking 33 provided in the ceiling region of the floor 21 . As shown in FIG. 6, the access point 32 a includes first and second transceivers 43 and 44 , and respective antennas 43 a and 44 a associated therewith. The access point 32 a is provided with a support wheel 45 which is rotatably mounted on a support structure 46 . The wheel 45 is engageable with the track 33 to enable the access point 32 a to be moved therealong. The access point 32 a can be moved either by hand, or by any suitable form of propulsion means such as those described above with reference to the access points 22 a to 22 i. The remaining access points 32 b to 32 i are similar construction. As with the embodiment of FIG. 2, each of the transceivers 43 is configured to use the Internet protocol, and each of the transceivers 44 is configured to use the IEE802.11B protocol.
[0025] It will be apparent that any LAN of FIG. 5 has similar advantages to the LAN of FIG. 2, in that it is considerably easier to reconfigure the known LANs. Thus, as the access points 32 a to 32 i are not hardwired together, they can be moved along the tracking 33 to accommodate different user configurations. It would also be possible to install one or more additional access points to accommodate new users. In either case, the reconfiguration is relatively simply, as there is no hardwiring to modify. It will also be appreciated, however, that in some cases it may be desirable to have a LAN in which some of the access points are fixed and some are movable—this may be desirable, for example, where a part of the demand is expected to remain fixed for a long period of time.
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A local area network comprises a plurality of access points. Each access point includes a first transceiver for wireless communication with one or more user workstations. The access points include second transceivers for wireless communication with one another. At least one of the access points is configured for movement to enable re-configuration of the local area network.
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FIELD OF THE INVENTION
This invention concerns a device with rollers to separate chips and particles of wood or material similar to wood of different gradings, and also the forming machine employing the said roller device, as set forth in the respective main claims.
The invention is applied in machines employed to select chips and particles according to their grading from a loose mass in the form of chips, shavings, fibres, granules etc., in order to then use the material, separated according to the different gradings, in the same machines.
To be more exact, the invention is applied to a separating device with a bed of rollers employed as a screen for chips, particles or fibres, of wood or material similar to wood, to be used by the said machine or to be sent to other processing, for example to refining processes for those parts not suitable for gravimetric selection, to gluing processes or other desired processes.
The invention is also applied to forming machines suitable to select the material according to its grading size and deposit it in super-imposed layers, each having its own range of different gradings; the layered mat thus formed is then generally sent to a pressing process to produce panels of wood or material similar to wood.
BACKGROUND OF THE INVENTION
For some time the state of the art has included screening devices to separate and select chips and particles according to their gradings from a loose or fibrous mass, whether it be dry or wet, generally but not exclusively of wood-based material.
Although the state of the art covers separating devices incorporating rollers, comprising adjacent rollers which rotate in the same direction and which define a bed on which the material to be selected is fed, in the past, and in the industrial field there was a large-scale preference to use screens of the type with a vibrating or oscillating netting, or also with rotary disks.
Within the range of these devices, screens with netting or with disks have been developed with one or more levels or orders of selecting elements; screens with netting or with disks using respectively meshes or gaps where the passage area is progressively increased, or also screens with netting or a disk with transverse bands, where the opening distance is progressively increased in order to discharge particles with a progressively increasing grading.
It is only in recent times that the use of screens and forming machines incorporating rollers has become of considerable importance in the industrial field, especially since materials which are highly resistant to wear, such as special steels, high resistance linings, etc., have become available at a reasonable cost.
The availability of these materials with very high surface resistance and hardness has made it possible, in recent years, to produce and employ separating devices with rollers, which have a great efficiency of production, a long life, and limited or no maintenance; this has made the applications of these machines, both simple screens on one or more levels, and also forming machines, extremely advantageous.
Although the technology of roller screens has been known to the state of the art for many years, it is only in recent years that it has found a real, large-scale industrial application, for the reasons given above.
In the light of these developments, linked to the increasingly evolved types of material available, there have been trials and experimentations in the field on solutions which substantially reproduce the effects and the functions of screens with netting and with disks, though their efficiency has been increased, thanks to the natural functionality of roller devices.
The natural functionality of roller devices is shown particularly in the selection of the fine particles, since the use of rollers instead of, for example, disks mounted on disk-bearing shafts, makes it possible to accurately gauge the gaps to an extremely reduced size which is both continuous and constant.
When disks are used, in fact, the discharge gap is of a substantially rectangular shape, where the distance between the surfaces of the adjacent disk-bearing shafts determines the length of the particles to be selected, while the distance between two adjacent disks mounted on the same shaft determines the thickness of the particles to be selected.
It should however be noted that neither netting screens nor disk screens normally allow the discharge gap in the individual sections of the selection bed to be varied during the operating cycle.
The natural functionality of roller devices has the following direct, resulting advantages:
the preferential choice of the reliefs on the surfaces of the rollers in order to obtain a more coherent screening with the chips, particles and fibres available, and with the specific desired result;
the possibility to distance the rollers reciprocally, both on the horizontal and vertical plane, so as to vary the discharge gap even during the operating cycle, and also to adjust, if so required, the speed of rotation of the rollers, also during the operating cycle.
These features have been the object of a multitude of patents, filed at different times and at long intervals, and therefore their solutions must be considered according to what technology was available at that specific time, with particular reference to the materials available and usable in the industrial field.
For example, U.S. Pat. No. 1,424, published in 1839, already discloses a separating device, in this case for the screening of lead oxide, including adjacent rollers equipped with grooves and penetrating peaks.
U.S. Pat. No. 292,656 also discloses rollers, with mating V-shaped threads on the surface, with a sloping and substantially helical development.
However, this embodiment has the disadvantage that it progressively displaces the material to be selected in a transverse direction with respect to the direction of feed.
U.S. Pat. No. 1,173,737, published in 1916, includes a screener with parallel rollers where the rollers include grooves cooperating with the mating tapered peaks of the adjacent rollers, and where the grooves are not penetrated by the peaks but together define a constant gap through which the particles can pass, the gap being substantially perpendicular to the direction of feed of the material.
U.S. Pat. No. 4,452,694 describes a selection device consisting of a plurality of disks arranged in a line in a plurality of parallel axes forming all together a conveyor bed for the material to be selected, the material being transported in a direction substantially at a right angle to the axis of the disks.
This conveyor bed includes a feeder end on one side and a discharge end at the other.
According to this document, the peripheral surface of the disks includes disks with protrusions or tapered peaks which position themselves in a mating position with tapered recesses or grooves on the adjacent disks.
According to this document, moreover, the rotary speeds of the disk-bearing shafts can be different.
WO 86/01580 refers to selection devices used in incinerator plants. It uses rollers which have on their surfaces protruding ribs with a development substantially parallel to the axis of the relative roller; the walls of the ribs are substantially perpendicular to the roller.
The ribs of one roller face the ribs of the other roller, but do not mutually penetrate each other, so that the discharge gap is substantially linear.
U.S. Pat. No. 3,387,795 discloses a device to process fibrous material comprising a plurality of adjacent rollers which include on their circumferential surface pyramid-shaped tapered protrusions, separated by tapered grooves, the protrusions penetrating at least partly into the tapered grooves of the adjacent roller.
EP-B-328.067 discloses a roller device where the outer circumferential surface of the rollers has individual tapered pyramid-shaped protuberances, developing substantially in a spiral around the surface of the rollers and extending lengthwise, separated by tapered grooves.
The tips of the protuberances of two adjacent rollers face one another and define the discharge gap for the selected material; therefore, there is no penetration of the grooves by the protuberances. The discharge gap is substantially constant, at a right angle to the direction of feed of the material, and parallel to the axis of the rollers.
This embodiment, compared with the afore-mentioned U.S. Pat. No. 1,173,737 substantially includes the sole characteristic that its protuberances are pyramid-shaped and tapered, and this characteristic is in any case included in the afore-mentioned U.S. Pat. No. 3,387,795.
The modifications to the surfaces of the rollers and the disks make it possible to reproduce the natural and intrinsic effect of the netting screens and forming machines on the chips, thus obtaining a good decantation of the finer particles.
Another function of these surface modifications is to delay the passage of the cubic particles through the discharge gap as a result of the dynamic thrust caused by the faces of the protrusions of the counter-opposed rollers.
Moreover, the inclusion of these surface modifications brings the advantage that they do not cause the rollers to jam when the device starts off again; in effect, this makes the roller devices comparable to the netting screens where no problems are caused when the screening is stopped.
The conformation of the surface modifications known to the state of the art, together with a discharge gap at right angles to the direction of feed of the material, proved to have, when used, a plurality of disadvantages which had not been foreseen.
To be more exact, it has been seen that with rollers of the type known to the state of the art the passage of long and light fibrous particles through the discharge gap is very difficult.
In fact, it is very difficult for fibrous particles which are much longer than the discharge gap to pass, even if they are less thick than the discharge gap, as these long particles tend to form a bridge and therefore are not discharged through the gap.
As a result, these particles are only discharged when the gaps are much thicker than the particles themselves, and consequently also discharge short particles and cubic particles of an undesired thickness, that is to say, excessively thick.
This is an extremely serious problem for the subsequent use of the particles and substantially compromises, in many cases, the possibility of using this type of screen, particularly in forming machines, since this widening of the gap leads to cubic particles being accepted, and the latter cause an “orange peel” effect on the surface layers of the mat.
For some time the process has been known to the state of the art, namely from U.S. Pat. Nos. 3,848,741, 4,209,097, CA-A-651.347, whereby the rollers are positioned on the horizontal plane and maintained parallel, in order to vary the gap between adjacent rollers.
DE-C-2.358.022 and SU-A-1.227.263 disclose how to move one roller in alternation to the adjacent roller on the vertical plane in order to vary the gap to discharge the material.
The state of the art also covers the fact that the speed of rotation of the rollers may be adjusted.
DE-A-95 874 refers to a roller-type sizing device for materials in particle form, specifically for coal particles.
The rollers are peripherally equipped with alternate peaks and grooves, wherein the peaks of one roller face the grooves on the adjacent roller.
The peaks and grooves may be rounded, segmented or with a sharp edge.
It is also possible that the surfaces of the peaks and grooves may have channels.
This document refers to the sizing of materials which, once crumbled, take on a shape substantially of little cubes or similar, according to what is said in the first part of the description.
Moreover, the description says that among these materials a flat shape is never found.
On the contrary, due to the fibrous nature of the material, wood chips and particles tend to have an elongated shape, with a thickness much less than their length and width.
With materials derived from wood, therefore, it is usual to find a flat shape, in fact it is the most frequent shape.
Particles which are thin and have elongated fibres are more valuable, and they must be sized in a most rigorous manner.
A device such as that described in DE'874, if applied to size wood chips and particles, would not carry out its function efficiently.
In fact, as explained before, particles of wood material which are flat, fibrous and light, and much greater in length than the discharge gap, tend to form a bridge and are not discharged through the discharge gap even if their thickness is less than the width of the said gap.
Because of this shortcoming, cube-shaped particles of a greater and therefore unacceptable thickness are also accepted, together with the long fibrous particles.
Moreover, the substantially flat shape of the surface of the rollers disclosed in DE'874, even if they have channels, causes only a partial vibration of the material which is not at all sufficient for long, flat particles like wood particles, even though it may be sufficient for large, heavy particles, square or cube like particles of coal.
Furthermore, the penetration of the grooves by the peaks is only partial and limited, and not even this characteristic is suitable if referred to sizing wood-based chips or particles.
GB-A-280,191 also refers to a sizing device for particles of coal or similar, and has the same disadvantages as DE'874.
Even if the discharge gap defined by the disks is in a zig-zag, this zig-zag development is obtained with large variations of section—a phenomenon which is not very suitable to select fibrous particles and wood chips correctly and in a uniform manner.
Moreover, the protrusions on the disks perform a cutting function, which may not damage heavy, cubic particles, but considerably damages long, light particles.
Furthermore, this document does not teach to provide a sufficient vibratory effect on the particles which are to be sized, and moreover the mutually penetrating disks do not allow thin particles to be gauged.
The present Applicants, aware of the optimum functioning of screens and forming machines incorporating netting, and considering the shortcomings of the state of the art in screens and forming machines incorporating disks and rollers, have designed, tested and embodied innovative solutions to be applied to roller devices, whether they be employed with the sole function of screening, with one or more beds of rollers arranged in sequence or on several planes with a constant or progressively increasing discharge gap, and also in possible applications for roller-type forming systems.
DISCLOSURE OF THE INVENTION
This invention is set forth and characterised in the respective main claims, while the dependent claims describe variants of the idea of the main embodiment.
The purpose of the invention is to provide a device with rollers, which can be applied both to screens with one or more levels and also roller-type forming machines, the device guaranteeing an efficient and selective separation of the particles of wood or material similar to wood according to their gradings, starting from a mass of loose and/or fibrous material.
This separation substantially reproduces what can be obtained by means of screens and forming machines using netting, except that a whole series of particular advantages are added, as will be explained hereafter.
When it is used as a screen, the roller device according to the invention can be arranged on a single plane, or there can be roller devices arranged on several planes in sequence or one above the other, each one having a respective value for the relative discharge gap.
When it is used in a forming station, the roller devices according to the invention are arranged on several planes, with a different discharge gap on each plane; they cooperate at the lower part with a conveyor belt on which the layered mat is gradually formed.
According to the invention, in the case of a forming machine, the rollers of each plane or level are arranged reciprocally at a constant distance between the axes, although adjustable, so as to select particles with a defined and different grading with respect to the roller device arranged on a different level.
The material which is not selected is discharged from the terminal end of the roller device above onto the one below, and so on.
According to the invention, the surface of the rollers includes circumferential V-shaped grooves, alternating with peaks, where the grooves in one roller mate with the peaks on the adjacent roller.
In this way, each roller is substantially conformed as a plurality of adjacent, V-shaped rings keyed onto a substantially cylindrical shaft or core.
According to one embodiment of the invention, at least some of the rollers have their respective connecting surfaces between the circumferential V-shaped peaks and grooves endowed with protuberances, protrusions or other type of desired shaping or working, facing towards the outside of the plane defined by these surfaces.
According to a variant, the connecting surfaces between the peaks and grooves have hollows or facets, facing towards the inside of the roller, which may be triangular, prismatic, semi-circular or oval in shape.
According to another embodiment of the invention, along the peaks and/or grooves of the rollers, protrusions or protuberances of a triangular or prismatic section are made in a lengthwise direction.
According to a further embodiment of the invention, the peaks and grooves have a curved and/or filleted development, with protuberances and/or hollows made in correspondence with the connecting surfaces.
According to the invention, the adjacent rollers include at least a working position where the peaks of one roller penetrate the grooves of the relative adjacent roller so as to define a discharge gap with a zig-zag development with respect to the direction of feed of the material.
In the roller device according to the invention, the rollers are individually, or in groups, adjustable both on the horizontal and on the vertical plane so as to vary, in both embodiments, the discharge gap during the operating cycle too.
The inventive idea of the invention, and particularly the surface conformation of the rollers, together with the discharge gap which has a zig-zag development with respect to the direction of feed of the material, allows a plurality of advantages to be obtained.
The first advantage is that at every step of the screening cycle an efficient vibration is maintained of the loose mass fed above the bed defined by the rollers; this is due to the zig-zag route obtained also along the direction of feed. The zig-zag route is defined by the peaks which face and penetrate the grooves. It causes the material to be continuously cut and separated by the tips of the V-shaped peaks as the material advances.
Moreover, making the discharge gap not perpendicular to the direction of feed of the material assists the alignment of the longer and finer fibrous particles, and reduces the risk of these particles leapfrogging over the discharge gap because of the bridge effect.
In fact, these long particles, separated and guided by the peaks, are arranged parallel to the connecting surfaces between the peaks and grooves, and are then discharged when there is a gap comparable with their thickness.
This improved condition for selecting the long and thin particles gives a better grading selection and therefore a better gauging of the thickness of the selected particles, inasmuch as the intense vibration of the particles encourages the fine particles to be decanted towards the discharge gap,
This reduces the necessity, as is often required in screens known to the state of the art, to subsequently pass the selected particles again through gravimetric selectors in order to eliminate any possible particles of too great a thickness, selected by mistake.
When the invention is used in a forming station, a considerable advantage is obtained by eliminating cubic particles from the surface layers of the mats of finished particles, and therefore by reducing the “orange peel” effect which they determine on the surface of the finished product.
This is achieved because, as we have already said, the long particles are discharged with a gap which is comparable with their thickness, and therefore, in order to discharge them, it is not necessary to widen the gap excessively, which, in devices known to the state of the art, also leads to the discharge of cubic particles onto the surface layers of the layered mat.
Moreover, the close, mutual penetration of the peaks and grooves of the adjacent rollers, creating a transit section substantially constant in width, acts as a limit to the length of the particles accepted; this length is defined by the development of the side surfaces of the peaks and grooves.
Another advantage, achieved by including a discharge gap with a zig-zag development transverse to the direction of feed of the material, is that a mat is obtained which is formed by super-imposed layers of crossed particles.
This arrangement considerably improves the mechanical characteristics of the finished panel in all its orientations.
In fact, roller-type forming machines known to the state of the art perform a random pouring of the particles or at most, with a preferential arrangement on the mat formed.
The negative result of this arrangement is that the finished product does not have a homogeneous resistance to bending; it is higher in the direction of preferential arrangement of the pouring, and lower in the non-preferential direction.
According to a variant, the screens include at least one terminal section of the type including disks.
In this embodiment, the distance between the centres of the disk-bearing shafts is adjustable so as to vary the thickness and/or the length of the particles selected, even during the operating cycle.
BRIEF DESCRIPTION OF THE DRAWINGS
The attached figures are given as a non-restrictive example, and show some preferred embodiments of the invention as follows:
FIG. 1 shows a first form of embodiment of a screen with rollers according to the invention;
FIG. 2 shows a second form of embodiment of a screen with rollers according to the invention;
FIG. 3 shows a variant of FIG. 2;
FIG. 4 shows an application of the invention in a forming station;
FIG. 5 a shows two adjacent rollers in a first form of embodiment of the invention, in a part view from above;
FIG. 5 b shows a side view of a roller in FIG. 5 a;
FIG. 5 c shows the detail B in FIG. 5 a;
FIG. 5 d shows a section from A to A in FIG. 5 b;
FIG. 6 a shows a variant of FIG. 5 a;
FIG. 6 b shows a side view of a roller in FIG. 6 a;
FIG. 6 c shows the detail C in FIG. 6 b;
FIG. 6 d shows a section from D to D in FIG. 6 b;
FIG. 7 a shows another variant of FIG. 5 a;
FIG. 7 b shows a side view of a roller in FIG. 7 a;
FIG. 7 c shows the detail E in FIG. 7 b;
FIG. 7 d shows a section from F to F in FIG. 7 b;
FIG. 8 a shows a further variant of FIG. 5 a;
FIG. 8 b shows a side view of a roller in FIG. 8 a;
FIG. 8 c shows the detail G in FIG. 8 b;
FIG. 9 shows the roller device according to the invention with the rollers distanced vertically;
FIGS. 10 a , 10 b and 10 c show other surface sections of the rollers according to the invention.
DESCRIPTION OF THE INVENTION
The roller device 10 according to the invention is employed for the selection of fine particles from a loose mass.
The roller device 10 comprises a plurality of rollers 11 rotating in the same direction and arranged adjacent so as to define a discharge gap 18 of the desired value, which is adjustable.
FIGS. 1, 2 and 3 show possible applications of the invention in screens 27 .
The screen 27 shown in FIG. 1 includes a feeder belt 21 , or other equivalent system, to feed the loose mass 16 of material which is to be selected, the feeder belt 21 cooperating with a metering/fluidizing assembly 17 .
The feeder belt 21 , in correspondence with one feeder end 14 a , discharges the material to be selected onto a first section 27 a of the screen 27 , this section 27 a consisting of a roller device 10 characterised by its own discharge gap 18 defined by the degree of penetration between adjacent rollers 11 .
The fine particles 19 b ,selected by the first section 27 a , are discharged onto a second section 27 b, characterised by a discharge gap 18 which is smaller than that of the first section 27 a ,in order to select particles 19 a of the finest degree.
The particles 19 b which are not selected by the second section 27 b fall and are discharged at the outlet end of the second section 27 b, and are sent to a subsequent processing step.
The particles not accepted by the first section 27 a fall and are discharged onto the third section 27 c, which has a discharge gap 18 greater than that of the first section 27 a , for the selection of particles 19 c of a greater grading.
The particles which are not selected even by the third section 27 c fall and are discharged onto the fourth section 27 d, which has a greater discharge gap 18 , for the selection of particles 19 d of a greater grading.
According to a variant not shown here, below the third section 27 d there is another screening section.
The particles not accepted by this fourth section 27 d are those with the maximum grading 19 e, which fall and are discharged from the outlet end of the fourth section 27 d which is also the outlet end 14 b of the screen 27 . In this case, the fourth section 27 d is of the type with penetrating disks 28 mounted on respective disk-bearing shafts 29 .
According to a variant, the third section 27 c of the screen 27 is also of the disk type.
According to the invention, at least the distance between the centres of the disk-bearing shafts 29 can be adjusted, even during the operating cycle, so as to vary the thickness of the particles to be selected.
The respective rollers 11 or disk-bearing shafts 29 of all the sections 27 a - 27 d of the screen 27 can be inclined on the horizontal plane (see the positions shown with a line of dashes) by an angle α which can have a value of as much as ±30°.
Moreover, all the rollers 11 or disk-bearing shafts 29 , apart from being adjustable on the horizontal plane in order to vary the distance between the centres, can be displaced with respect to each other on the vertical plane (see FIG. 9) so as to vary the discharge gap also during the operating cycle.
It is also possible to adjust the speed of rotation of the rollers 11 or the disk-bearing shafts 29 , even during the operating cycle.
The variant shown in FIG. 2 differs from the embodiment shown in FIG. 1 in that the sections 27 a , 27 c and 27 d are all arranged on the same horizontal plane and that section 27 d is also of the roller type.
The further variant as shown in FIG. 3 differs from that of FIG. 2 in that the fourth section 27 d of the screen 27 is of the disk type.
FIG. 4 shows an application of the invention in a forming station 20 , that is, a station suitable to form, on a forming belt 15 , or on any other type of equivalent movable device, a mat of particles arranged in super-imposed layers, in this case, a lower layer 31 a, an intermediate layer 31 b, and an upper layer 31 c, each one characterised by its own defined range of grading.
According to a variant not shown here, the forming belt 15 is stationary and the whole forming station 20 moves.
In this case, the forming station 20 consists of three roller devices 10 according to the invention, respectively 10 a, 10 b and 10 c, each one arranged on a respective plane and each one defined by its own discharge gap 18 which is constant and different from that of the other roller device 10 above or below.
The first roller device 10 a selects fine particles 19 a which are deposited on the conveyor belt 15 so as to form the first layer 31 a of the mat.
The particles not accepted by the roller device 10 a fall and are discharged onto the second roller device 10 b, defined by a discharge gap 18 which is greater in size and which causes particles 19 b , of a larger grading, to be accepted so as to form a second layer 31 b.
The particles not accepted by the second roller device 10 b are discharged onto the roller device 10 c, defined by a discharge gap 18 which is even larger, and which causes particles 19 c, of an even larger grading, to be accepted so as to form another layer 31 c of the mat.
Those particles 19 d which are not even selected by the third roller device 10 c are discharged by means of a transporter belt 30 .
According to the invention (see FIGS. 5 a, 6 a, 7 a and 8 a ) each. roller 11 of the roller device 10 includes on its surface an alternation of circumferential peaks 12 and grooves 13 . These peaks 12 and/or grooves 13 have a sharp edge at their tip, or, according to a variant, the tip is at least filleted or rounded, as can be seen in FIG. 7 a.
The peaks 12 and grooves 13 are arranged parallel to each other on the circumference of the relative roller 11 and extend at a right angle to the axis 11 a of the roller 11 , substantially lengthwise to the direction of feed of the material which is to be selected.
In at least one working position, the peaks 12 of one roller 11 closely penetrate the grooves 13 of the adjacent roller 11 (FIGS. 5 a, 6 a, 7 a, 8 a ) in such a manner that the discharge gap 18 between the adjacent rollers 11 has a substantially zig-zag development with respect to the axis 11 a of the relative roller 11 .
The distance “p” between the tips of two adjacent peaks is inside the range of 3/4 and 1/20 of the outer diameter “d” of the relative roller 11 .
In the embodiment shown in FIGS. 5 a - 5 d, the surfaces 26 connecting the peaks 12 and the grooves 13 have pyramid-shaped protrusions 24 with a substantially square base, arranged along generation lines 124 substantially helical or radial.
The size “s” of the side of the base of the pyramid-shaped protrusions 24 is inside the range of 1/40 and 1/10 of the outer diameter “d”.
In the variant shown in FIGS. 6 a - 6 d, the connecting surfaces 26 have raised parts shaped like a parallelepipedon or prism 25 , aligned along one (FIG. 6 a ) or more circumferential orders (FIGS. 6 c , 6 d ), in this case arranged in a straight line along the lateral. development of the connecting surface 26 .
In the variants shown in FIGS. 10 b and 10 c, the parallelepipedon or prism-shaped raised parts 25 are helically inclined, respectively left-hand or right-hand, with respect to the lateral development of the connecting surfaces 26 .
The relative side walls of these parallelepipedon or prism-shaped raised parts 25 are arranged substantially at a right angle to the plane defined by the connecting surfaces 26 , or tapered with the tip facing outwards.
In the embodiment shown in FIGS. 7 a - 7 d, on the connecting surfaces 26 between the peaks 12 and the grooves 13 there are hollows or bevels 23 of a substantially oblong shape.
In the preferred embodiment of the invention, the depth of the hollows/bevels 23 is defined as “q”, which is in the range of 1/15 and 1/300 of the outer diameter “d” of the roller 11 , the length is “r”, between 1/120 and 1/8 and the width is “t”, between 1/150 and 1/20 of the outer diameter “d”.
The oblong hollows/bevels 23 can be substantially parallel to the axis 11 a of the roller 11 , or they can be sloping with respect to the axis 11 a (see the profile in FIG. 10 a ) in one direction or the other.
In the embodiment shown in FIGS. 8 a - 8 c , in cooperation with each peak 12 , and lengthwise to it, there are protrusions and/or protuberances 22 , in this case substantially pyramid-shaped with a square base.
According to a variant which is not shown here, the protrusions 22 are prism-shaped.
The protrusions/protuberances 22 , in this case, have a height “m” (FIG. 8 c ) with respect to the base of the groove 13 inside a range of 1/50 and 1/5 of the outer diameter “d” of the relative roller 11 . The distance “n” between the tips of the adjacent protrusions/protuberances 22 is inside a range of 1/50 and 1/10 of the diameter “d” of the relative roller 11 .
It is possible to achieve other, different profiles of the protrusions/protuberances, or of the hollows on the connecting surfaces 26 between the peaks 12 and the grooves 13 , still remaining within the field of the invention.
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Device incorporating rollers to separate particles of different gradings a plurality of adjacent rollers ( 11 ) forming a selection bed where each roller ( 11 ) has a surface conformation defining a plurality of circumferential peaks ( 12 ) alternating with circumferential grooves ( 13 ), the rollers ( 11 ) including at least a working position where the grooves ( 13 ) of one roller are facing and at least partly penetrated by the peaks ( 12 ) of the adjacent roller ( 11 ), the discharge gap ( 18 ) between the two adjacent rollers ( 11 ) having a substantially zig-zag development, in at least some rollers ( 11 ) the connection surface ( 26 ) between the peaks ( 12 ) and grooves ( 13 ), and/or the peaks ( 12 ) and/or the grooves ( 13 ) themselves being at least partly worked with protuberances, protrusions, hollows and/or facets ( 23, 24, 25 ).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of the instant invention relates to polymeric material, particularly as used in laminates with metal in the electronic industry.
2. Description of the Known Art
A polymeric material is known from U.S. Pat. No. 4,468,485. In this patent specification the polymer that can be cross-linked under the influence of radicals is an unsaturated polyester resin. The epoxy resin is of the DGEBA type (diglycidyl ether of Bisphenol-A) and is cross-linked using a polyfunctional amine. For the preparation of an interpenetrating network (IPN) without phase separation the above-mentioned patent specification describes a process in which use is made of microwave radiation of a frequency spectrum so chosen as to effect the cross-linking of the polyester, with the heat released in this process triggering the cross-linking reaction of the epoxy resin.
Admittedly, in this manner there is obtained a polymeric material which has one single glass transition temperature (Tg) (in the range of 50°-100° C. depending on the IPN's composition), but the process used is not universally applicable. Although said patent specification does teach the skilled man a process for the preparation of IPNs, it offers no teaching on how, by the proper selection of IPN components, suitable electronic materials can be manufactured.
It is generally known that there is a need to replace the present electronic materials with materials meeting requirements such as
low dielectric constant
low electrical dissipation factor
high Tg
ready processability
low price
high dimensional stability
high solvent resistance
more satisfactorily.
The instant invention employs IPN technology to obtain materials especially suited to be used in the electronics industry.
SUMMARY OF THE INVENTION
The present invention is a polymeric material comprising an interpenetrating network (IPN) built up from a polymer that can be cross-linked in the presence of a free radical catalyst and an epoxy resin comprising a cross-linking agent. The polymer is built up from at least one cyclic moiety-containing polyallyl compound which may or may not be combined with an aromatic difunctional methacylate. The cross-linking agent for the epoxy resin is a polyhydric phenol or a cyclic carboxylic anhydride not containing a functional group polymerizable under the influence of radicals.
DETAILED DESCRIPTION OF THE INVENTION
The two IPN-forming polymer and epoxy resin are mixed in such a ratio as to give a resin of which the properties are no longer determined by one of the IPN constituents individually. Although this ratio is to some extent dependent on the type of allyl compound and the type of epoxy resin used, in general a weight ratio of 80/20 or 20/80 will be adhered to as a limit. Since both the allyl polymer and the epoxy resin provide a share of the favorable IPN properties, the preferred ratio is dependent on those properties which are especially envisaged. If it is desired to stress electrical or thermal properties, then a ratio of allyl polymer to epoxy resin of 70/30-60/40 will be selected; if the manufacture is desired of a laminate with a metal layer (such as for printed circuits), then a ratio of allyl polymer to epoxy resin of 30/70-40/60 will be chosen on account of the favorable peel strength. Preference is given to an IPN in which the properties of the two constituents come out optimally. This is the case for a ratio of allyl polymer to epoxy resin of 40/60-60/40, more preferably 50/50.
It should be noted that the above-mentioned cross-linking agents for epoxy resin are known. However, what is novel and surprising is that from an epoxy resin to be cross-linked with the aforesaid materials and ring-containing allyl polymers an IPN is obtained with one glass transition temperature (Tg), since it is known from U.S. Pat. No. 4,468,485 already referred to above that, if the method described in that specification is not followed, in general IPN synthesis will give rise to structures with phase separation.
It should further be noted that in U.S. Pat. No. 4,604,317 and 4,661,568 (corresponding to WO 85/03515 and 86/02085, respectively) an epoxy resin is described which is used for the manufacture of electronic materials. The advantage to the IPNs according to the invention is that, compared with these electronic materials which are made up exclusively of epoxy resin, they are less expensive, have more favorable electrical properties, display a higher solvent resistance, and are fire retardant at a lower bromine content, which is beneficial to the environment.
The polymer that can be cross-linked in the presence of a free radical catalyst is built up from ring-containing polyallyl compounds. To prepare the polymer the allyl compounds may be employed either in the monomeric or the oligomeric (prepolymeric) form.
As suitable polyallyl compounds may be mentioned triallyl cyanurate (TAC), triallyl isocyanurate (TAIC), and aromatic polyallyl esters such as diallyl phthalate, diallyl isophthalate, diallyl terephthalate, triallyl trimellitate, tetrallyl pyromellitate, and diallyl tetrabromophthalate.
The structural formulae of TAC and TAIC are given below: ##STR1##
TAC and TAIC prepolymers can be prepared by the partial polymerization of TAC monomer or TAIC monomer in, say, methylethyl ketone (MEK) in the presence of a peroxide of a relatively low decomposition temperature, e.g. dibenzoyl peroxide or di(orthomethylbenzoyl) peroxide. The monomer conversion, the viscosity, and the molecular weight distribution of the TAC or TAIC oligomers can be controlled by means of the amount of peroxide employed and the reaction time. Optionally, use may be made in the polymerization process of a chain regulator such as carbon tetrabromide to prevent the prepolymerization resulting in gelling.
As is known to the skilled man, it is possible to remove monomers from TAC or TAIC prepolymers by selective precipitation, using a suitable organic solvent.
Aromatic polyallyl esters can be illustrated using the following general structural formula: ##STR2## wherein n=2, 3 or 4 and each X individually represents hydrogen or halogen (especially bromine).
Of course, suitable ring-containing polyallyl compounds are not restricted to the above-indicated structural formulae.
Preferably, the polyallyl compound used is TAC (in the monomeric or prepolymeric form), since this will give an IPN with optimal thermal properties. Moreover, TAC has the advantage that it may also serve as a solvent in the IPN preparation; consequently, additional solvent may largely be omitted.
Aromatic difunctional methacrylates may be used to partially replace the polyallyl compounds in the IPN. Suitable methacrylates may be of the following structural formula: ##STR3## wherein R and R 1 may be the same or different and represent H or CH 3 , n and m may be the same or different and 0, 1, 2, 3 or 4, with n+m being 4 maximum, and wherein A represents a hydrocarbon group having 1-6 carbon atoms, or else stands for ##STR4## Preferably, use is made of 2,2-di(4-methacryloxyethoxyphenyl)propane (BMEPP).
The polymerization of the ring-containing polyallyl compounds is carried out under the influence of an initiator that will generally be employed in a ratio of 0.1-5 wt. %, calculated on the allyl compound. Examples of suitable initiators include peroxides, such as t-butylperoxy benzoate, t-butylperoxy-3,5,5-trimethyl hexanoate, and benzoyl peroxide.
By the term "epoxy resin" is meant a curable composition of oxirane ring-containing compounds. Such compounds have been described in C. A. May's "Epoxy Resins", 2nd. Edition, Marcel Dekker Inc., New York & Basle, 1988.
As examples of epoxy resins may be mentioned phenol types, such as those based on the diglycidyl ether of Bisphenol-A, on polyglycidyl ethers of phenol-formaldehyde Novolac or cresol-formaldehyde Novolac, on the triglycidyl ether of tris(p-hydroxyphenol)methane, or on the tetraglycidyl ether of tetraphenyl ethane; amine types, such as those based on tetraglycidyl methylene dianiline or on the triglycidyl ether of p-aminoglycol; and cycloaliphatic types, such as those based on 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate.
By the term "epoxy resin" are also meant reaction products of compounds (e.g. of the foregoing types) containing an excess of epoxy with aromatic dihydro compounds. These dihydro compounds may be halogen substituted. The same epoxy resins were described in WO 86/02085 referred to above.
Preference is given to epoxy resins of the phenol type, especially because of their low price.
It should be noted that, as a rule, one unequivocal structural formula is used to illustrate epoxy resins. Differing products resulting from side reactions which occur in the preparation of epoxy resins should, as the skilled man products form a standard constituent of cured epoxy resins, so they make up a standard constituent of the IPNs according to he invention.
It is of importance that the epoxy resin be so cured as to give a non-segregated IPN. Moreover, the curing method has its effect on the IPN's final material properties.
To obtain a non-segregated IPN of favorable properties the epoxy resin is cured using the types of cross-linking agent referred to above. As examples of polyhydric phenols may be mentioned aromatic dihydroxy compounds of such formulae as ##STR5## wherein A represents an aliphatic or alicyclic hydrocarbon group having 1-12 carbon atoms, ##STR6## Y stands for halogen, notably bromine or chlorine, R or OR, with R being a hydrocarbon group having 1-10 carbon atoms; and wherein n=0 or 1 and m=0, 1, 2, 3 or 4. Alternatively, Novolac resins such as phenol/formaldehyde, cresol/formaldehyde or phenol/p-hydroxybenzaldehyde may serve as polyhydric phenol cross-linking agent.
The invention will be further illustrated with reference to the following nonlimiting examples.
Further explanation:
Epoxy resin A is a polyglycidyl ether of a phenol-hydroxy-benzaldehyde condensate having an epoxy equivalent weight (EEW) of 220 and an average epoxy functionality of 3.5.
Epoxy resin B is a phenol-formaldehyde Novolac epoxy resin having an average epoxy functionality of 3.5 and an EEW of 178.
Epoxy resin C is a Bisphenol A bisepoxide resin having an EEW of 174.
Epoxy resin D is a 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate having an EEW of 137.
Determination of Properties
The glass transition temperature (Tg) was determined with a Differential Scanning Calorimeter (DSC) manufactured by Dupont, basic module 990 with DSC module 910 at a heating rate of 10° C./min in an atmosphere of nitrogen.
The coefficient of thermal expansion (TEC) in the z-direction and also Tg were determined using a Dupont Thermal Mechanical Analyzer (TMA), basic module 990 with TMA module 942 at 100 ml/min in an atmosphere of nitrogen. Values were determined both during heating (5° C./min) and cooling (2° C./min).
The decomposition behavior of neat resins was studied with a Dupont Thermo-Gravimetric Analyzer (TGA), basic module 990 with TGA module 951 at a heating rate of 10° C./min in an atmosphere of nitrogen. The study of laminates was conducted in air.
Cured resins were tested for fire retardancy by means of a manual test in which the sample to be tested was held in a flame for 30 seconds. The sample was considered to be fire retardant, if it stopped burning immediately upon being removed from the flame.
Laminates were tested for fire retardancy in accordance with the UL-94 test, which is known to the skilled man.
EXAMPLE 0
Preparation of TAC prepolymer (used in Examples 1, 8, 9, 11, 12 and 13)
To 1 kg of molten TAC monomer in a reactor (fitted with a cooling apparatus and a stirrer) were added 223 g of MEK. Next, the contents of the reactor were heated to 82° C., with stirring, and over a period of 1 hour there was added dropwise a solution of 4.4 g of di(ortho-methylbenzoyl)peroxide in 100 g of MEK phlegmatized with 1.2 g of water.
After a total reaction period of 8 hours at 82° C. the 75% solution of TAC prepolymer in MEK was cooled down to room temperature. Next, MEK was stripped off under reduced pressure. The result was a TAC prepolymer containing less than 2% of MEK residue with a (Brookfield) viscosity of 1250 mPa.s at 23° C., a monomer conversion (mc) of 37%, a number average molecular weight (Mn) of 8000, and a degree of dispersion (D) of 13 (by HPLC relative to Styrene standards).
EXAMPLE 1
66.7 g of a solution prepared from 52.76 g (0.194 equivalents) of tetrabromo Bisphenol-A (TBBPA), 47.24 g of epoxy resin A (0.215 equivalents), and 33.3 g of MEK were mixed, with stirring, with 50 g of TAC prepolymer (mc 37%, Mn 8000, D 13, viscosity 1250 mPa.s). The part by weight of TAC prepolymer thus was equal to that of epoxy resin A plus TBBPA.
To the mixture, which contained 12.5 wt. % of methylethyl ketone (MEK),was added 0.5 g of a 10 wt. % solution of 2-ethyl-4-methyl imidazole (2E4MI) in MEK and, subsequently, 0.5 g of tert. butylperoxy perbenzoate. The resin solution was then poured into aluminum dishes in such a way as to give a layer thickness for the resin solution of about 1 mm.
Next, the samples were heated to 60° C. in a forced-circulation air oven and kept at this temperature for 1 hour. The temperature of the oven was then raised to and kept for 30 minutes at 100° C., followed by 3 hours at 150° C. and, finally, 30 minutes at 180° C. After the orangish-brown, homogeneously transparent plates had been cooled slowly and released from the mould, the samples were post-cured for a further 2 hours at 200° C. and then cooled to room temperature. The following properties were measured on the flat, cured plates of a thickness of about 1 mm:
______________________________________Tg (°C.)by DSC (mid point) 186TMA 191TECz (ppm/°C.)< Tg 48> Tg 198average (over 20°-250° C.) 102TGA (in an atmosphere of nitrogen)loss at 300° C. (%) 2.0decomposition maxima (°C.) 325 and 394residue at 650° C.° (%) 24Manual flame test, fire retardant? yes______________________________________
EXAMPLE 2
The prepreg and laminates were prepared on the basis of a resin solution consisting of:
921 g of a 76%-solution of 330.68 g of epoxy resin A and 369.32 g of TBBPA in MEK;
933 g of a 75%-solution of TAC prepolymer (having a monomer conversion of 36%, Mn=9035, D=15.2, prepared with the use of benzoyl peroxide as initiator) in MEK;
4.7 g of a 15%-solution of 2-ethyl-4-methyl imidazole in acetone;
7.0 g of t-butylperoxy benzoate; and
50 g of acetone.
The resin solution in which the TAC prepolymer part by weight was equal to that of epoxy A plus TBBPA had a viscosity of 50 mPa.s determined in accordance with the instructions by Brookfield at 23° C.
The E-glass fabric type 7628 (finishing agent Z6040) much used in the electronics industry was manually impregnated with the resin solution. Next, the impregnated fabrics were kept at a temperature of 160° C. in a forced-circulation air oven for 286 seconds, resulting in tack-free prepregs of excellent appearance being obtained in the B stage. The percentage by volume of resin in the prepreg was 65%.
Eight prepregs stacked one on top of the other were molded in an autoclave at a pressure of 15 atm. and a temperature of, successively, 150° C. for 30 minutes, 180° C. for 30 minutes, and, finally, 200° C. for 30 minutes. Heating and cooling was at a rate of 3.5° C./min.
In this manner both a laminate coated on one side with copper (1 ounce, electrodeposited type) and an uncoated laminate of an overall thickness of 1.60 mm were made.
The properties of the laminate and two reference laminates are given in Table 1. Reference laminate 1 is a purchased standard FR4 laminate that is used on a very wide scale in the printed board industry and contains, in addition to E-glass fabric, a resin made up of brominated Bisphenol A bisepoxy, with dicyanodiamide as curing agent.
The preparation of reference material 2 was analogous to that of the laminate described in Example 2, except that the 65%-solution of resin in MEK contained 490 g (2.227 equivalents) of epoxy A, 544 g (2.000 equivalents) of TBBPA, and 0.72 g of 2-methyl imidazole. Prepregs of this type of resin were prepared in an oven at 175° C. for 60 seconds and molded to form a laminate over a period of 60 minutes at a pressure of 15 atm. and a temperature of 175° C.
The properties of the two reference laminates, each 1.6 mm thick, are given in Table 1.
Besides the aforementioned techniques the following methods/processes were employed to determine a number of additional properties.
Tg was determined with a type MK1 dynamic, mechanical, thermal analysis (DMTA) apparatus of Polymer Laboratories at 10 Hz under an atmosphere of nitrogen and at a heating rate of 5° C./min.
The water absorption was determined in accordance with I.P.C. (Institute for Interconnecting and Packaging Electronic Circuits) TM 650 method 2.6.2.1.
The dichloromethane absorption was determined in conformity with I.P.C. TM 650 method 2.3.4.3., i.e. over a period of 30'. A second measurement was carried out after 1 week.
The dielectric constant and the dissipation factor were measured at 1 MHz on samples which, after having been dried for 30' at 50° C. and cooled in a dessicator, were stored for at least 40 hours at 23° C. in an atmosphere of 50% relative humidity.
The copper peel strength was measured at 23° C. at an angle of 90° C. on a laminate sample of 14×2 on which there was a strip of copper of 3 mm wide. The measuring process was effected by removing excess copper from a copper laminate in a known manner by etching. The peel strength was also measured on samples of which the copper side had been place on hot solder for 10" (Solder float test).
TABLE 1______________________________________ Ref. 1 Example 2 (FR-4) Ref. 2______________________________________Tg (°C.)by DSC (center) [185].sup.a 120 [180].sup.aDMTA (damping maximum) 180 [190].sup.a 125 170 [180].sup.aTMA 165 [170].sup.a 115 160 [165].sup.aTECz (ppm/°C.)< Tg 25 36 30> Tg 225 236 251average (over 20°-250°C.) 110 154 123TGA (in air)loss at 300° C. (%) 1.6 1.2 1.0decomposition maximum (°C.) 325 320 335residual glass (= wt. % 63 65 62glass) (%)Dielectric constant 4.2 4.9 4.7(ε.sub.r) at 1 MHzDissipation factor 0.007 0.03 0.012(tan δ) at 1 MHzWater absorption (%) 0.1 0.1 0.1Dichloromethane absorptionafter 30' <0.1 0.6 1.80 [0.20].sup.aafter 1 week 1.4 [0.4].sup.a 21.9* 23 [8].sup.aFire retardancy UL 94, VO VO VOclassBromine content in 5.7 7.4 11.7laminate (%)Copper peel strength (N/cm)as such 14 14 16after solder bath 10" 14b n.b. n.b.(260'C.)after solder bath 10" 12b n.b. n.b.(288° C.)______________________________________ .sup.a values in brackets were measured on samples subjected to an additional postcuring treatment in an oven at 200° C. for 2 hours. .sup.b there was no blistering and/or delamination. .sup.c there was delamination.
EXAMPLES 3 THROUGH 9
Analogous to the description in Example 1 resins of the composition indicated in Table 2 were prepared in Examples 3 through 9. The properties of the resulting cured resins are to be found in the same table.
EXAMPLE 10
Analogous to the Examples 1 and 3 through 9, except that a portion of the allyl compound was replaced with 2,2-bis(4-methacryloxy-ethoxyphenyl)propane (BMEPP). The composition of the resin formulation and the properties measured on the cured resin are listed below.
______________________________________TAC monomer 16 gBMEPP 24 gEpoxy resin A 28.34 g (0.130 equiv.)TBBPA 31.66 g (0.116 equiv.)fraction by weight 0.40TAC plus BMEPP calculatedon overall weight10% of 2MI in 2-methoxyisopropanol 3.0 gt-butylperoxy perbenzoate 1.2 gMEK 20.4 gcalculated bromine % 18.6Results:Tg (°C.) by TMA 150TEC.sub.z (ppm/°C.) 30TGAloss at 300° C. (%) 2decomposition maximum (°C.) 320residual at 650° C. (%) 25flame test, fire retardant? yes______________________________________
EXAMPLES 11 AND 12
In Examples 11 and 12 two non-flame retardant interpenetrating network resin compositions were prepared analogous to Example 1.
In Example 11 hexahydrophthalic anhydride (HHPA) was employed as curing agent for the epoxy and in Example 12 Bisphenol A (BPA).
The composition and properties are compiled in Table 3.
TABLE 2__________________________________________________________________________Resin compositionand properties ofthe cured resin Example 3 Example 4 Example 5 Example 6 Example 7 Example Example__________________________________________________________________________ 9Allyl compound TACmon./70 TACmon./40 TAC mon./25 TACprep.sup.a /50 DAPmon.sup.c /40 TACprep./50 TACprep./50type/g TAICmon./25Epoxy A/14.17/0.065 A/28.34/0.130 A/23.62/0.108 A/23.62/0.108 A/28.34/0.130 B/20/0.112 C/20/0.115type/g/equivalentTBBPA 15.83/0.058 31.66/0.116 26.38/0.097 26.38/0.097 31.66/0.116 30/0.110 30/0.110g/equivalentFraction by weight 0.70 0.40 0.50 0.50 0.40 0.50 0.50of allyl calculatedon overall (b)10% of 2E4MI in 1.5 -- 1.0 1.5 -- 1.0 1.0MEK (g)10% of 2E4MI in -- 3.6 -- -- 3.0 --2-methoxy-isoprop. (g)t-butylperoxy 2.1 1.2 1.5 0.5 1.2 0.5 0.5perbenzoate (g)MEK (g) 10 20.4 16.7 16.7 20.4 16.7 16.7calculated Br. % 9.3 18.6 15.5 15.5 18.6 17.6 17.6Tg (TMA), °C. 191 150 151 135 120 175 178TEC.sub.z < Tg, ppm/° C. 50 30 25 46 30 68 30TGAloss at 300° C., % 1.8 2.8 3 4 4 2 2decomp. max., °C. 324 and 389 325 and 395 323 and 397 350 350 322 and 330 and 385residual at 650° C., % 19 25 29 26 27 24 17flame test, yes yes yes yes yes yes yesfire retardant?__________________________________________________________________________ .sup.a mc = 14%, Mn = 2990, D = 2.85, visc. = 220 mPa · S .sup.b fraction by weight of allyl compound calculated on overall amount of allyl, epoxy, and curing agent .sup.c DAP mon = orthodiallyl phthalate monomer
TABLE 3______________________________________ Example 11 Example 12______________________________________TAC prepolymer (g) 50 50Epoxy resin B g/equivalent 27/0.152 31/0.174HHPA g/equivalent 23/0.149 --BPA g/equivalent -- 19/0.167fraction by weight of TAC prepreg 0.50 0.50calculated on overall weight10% of 2MI in 2-methoxyisopropanol 1.0 --(g)10% of 2E4MZ in MEK (g) -- 2.5t-butylperoxy perbenzoate (g) 0.5 0.5MEK (g) 10 16.7dimethyl formamide (g) 7 --Results:Tg (°C.) by TMA 120 168T.C.E..sub.z < Tg (ppm/°C.) 80 55TGAloss at 300° C. (%) 2.0 2.0decomp. max. (°C.) 430 430residual at 650° C. 8 17______________________________________
EXAMPLE 13
Analogous to Example 1 an interpenetrating network resin composition was prepared of which composition and properties are outlined below:
______________________________________Composition:______________________________________TAC prepolymer (g) 50Epoxy resin D g/equivalent 17/0.124TBBPA g/equivalent 33/0.121fraction by weight of TAC prepreg 0.50calculated on overall weight10% of 2E4MI in MEK (g) 0.5t-butylperoxy perbenzoate (g) 0.5MEK (g) 20calculated bromine content (%) 19.4Results:Tg (°C.) by DSC (mid-point) 135 Tg (°C.)by TMA 144T.C.E..sub.z < Tg (ppm/°C.) 40TGAloss at 300° C. (%) 3.0decomp. max. (°C.) 308; 370residual at 650° C. 12flame test, fire retardant? yes______________________________________
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A polymeric material used in laminates with metal-comprises an interpenetrating polymer network composed of a cyclic moiety-containing pollyallyl compound optionally with an aromatic difunctional compound (co)polymerized and cross-linked in the presence of a free radical initiator, and an epoxy resin cross-linked with a polyhydric phenol.
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RELATED APPLICATIONS
[0001] The present application is based on, and claims priority from, Taiwan Application Serial Number 93116183, filed on Jun. 4, 2004, the disclosure of which is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for treating surfaces of textile, and more particularly, to a method of manufacturing textile with one or multi-functions.
BACKGROUND OF THE INVENTION
[0003] Depending on the different requirements for the function of textile products, the textile products that merely provide a warmth-keeping function do not satisfy the requirement of the customers. The textile industry continues to develop textiles with more functions, for example, the textile products with single or composite functions such as hydrophobicity, anti-bacteria or hydrophilicity (hygroscopicity) The textile with the hydrophobic function is coated with a hydrophobic material on the outer surface thereof, the one with the hydrophilic function is coated with a hydrophilic material on the inner surface thereof, and the one with the anti-bacterial function is coated with a anti-bacterial material on the surface thereof.
[0004] However, when such different materials are coated on the same or different surfaces, respectively, some problems often occur, for example, the spreading layer is coated unevenly and unfirmly. The prior arts have disclosed the methods for solving the problem of the unfirm spreading layer resulting in less wash ability. For example, TW Patent Pub. No. 429,280 discloses a surface treatment method, in which fibers are activated in a high ion density microwave plasma system for forming free radicals on surfaces, and then grafted with functional monomer for giving the textile products with specific hydrophilic function. Moreover, JP Patent Pub. No. 11-256,476 discloses a method for the modification of a single surface of a woven or knit fabric or a non-woven fabric. The fabric is subjected to low-temperature plasma treatment, so as to obtain a woven or knit fabric or a non-woven fabric having different functions between the front and back surfaces. Furthermore, JP Patent Pub. No. 2001-159,074 discloses a method for modifying one side of a fabric. The textile or non-woven fabric is subjected to atmospheric plasma treatment for 8 hours, so as to obtain the textile or non-woven fabric having different function in surface and reverse face. Nevertheless, the single surface modification subjected to energy irradiation has disadvantages as follows. On one hand, the process of the fabric, one surface of which is modified by low-temperature plasma treatment for giving the textile products with specific hydrophilic function, must be carried out in a vacuum condition, but the apparatus is cost-intensive. On the other hand, during the process of the fabric is treated by atmospheric plasma, the gas mixtures that contain helium or argon, nitrogen and acrylic acid must be introduced by separating into several times in graft-processing for approximately 24 hours to 36 hours. Therefore, this process is difficult to perform a continuously mass production.
[0005] Besides, WO Patent Pub. No. 02,075,038 discloses a textile surface, which increases the viscosity of the functional resin(chemical) to inhibit it diffusing, so as to achieve the function of single side coating. However, this conventional coating or halftone transferring processing has disadvantages as follows. First, if a conventionally coating process is applied, the viscosity of the functional resin(chemical) must be increased for coating the resin(chemical) on the single side of the textile, but that will increase the instability of processing. Second, in the conventionally coating process, the amount of the resin must be coated in a range of 30 g/m 2 to 200 g/m 2 . But that is difficult to carry out an ultra-thin coating treatment, and the basic fabric for processing is limited, as well as the softness of the textile is affected. Third, the intermediate, such as a thickening agent or an isolating agent, is added for increasing the viscosity of the resin, resulting in water spots on the textile products. Fourth, the conventionally coating process is difficult for coating on both sides, so the textile is difficult to have composite functions.
[0006] Therefore, it is necessary to resolve the problem of the textile with composite functions, so as to effectively coat spreading materials with different functions on one and the other sides of the textile, respectively, and to keep the textile soft, comfortable and washable.
SUMMARY OF THE INVENTION
[0007] According to the aforementioned description, it is an aspect of the present invention to provide a method for treating surfaces of textile, for forming at least one ultra-thin functional spreading layer on the surface of the textile by a continuous process. Therefore, a firm, washable textile with single or multi-function is obtained.
[0008] It is another aspect of the present invention to provide a method for treating surfaces of textile, which utilizes a polymer with reactive groups to form a coating solution with various functions, such as hydrophobicity, anti-bacteria or hydrophilicity (hygroscopicity), by employing a surface treating technique of gravure coating, and appropriately selecting the groove shape and the gravure meshes. Next, the spreading solution with various functions and doses (such as viscosity, concentration, and thickness) is coated on the surface of the textile by employing a continuously coating technique. After an anchoring treatment such as thermal drying, the functional spreading solution is fixed on the surface of the textile by a reactive site, so as to produce a textile that has a functional surface, such as one hydrophobic surface and the other anti-bacterial and hydrophilic (hygroscopic) surface.
[0009] It is a further aspect of the present invention to provide a method for treating surfaces of textile by utilizing a gravure coating manner, which adjusts gravure meshes to freely regulate a viscosity, concentration, coating thickness and other variables of the functional chemicals. After an anchoring manner by an air drying such as thermal drying, an anchor is generated from the functional chemicals on the whole or partial surface of the textile. The drying process is speedy, and the method of the present invention increases a textile with multi-functions in fastness and wash durability.
[0010] It is still another aspect of the present invention to provide a method for treating surfaces of textile by utilizing a gravure coating manner, which selects the groove shape, meshes of the gravure roller, a viscosity and concentration (solid content) of the functional chemicals, to freely regulate a coating thickness of the functional resin (chemical).
[0011] It is yet another aspect of the present invention to provide a method for treating surfaces of textile by utilizing a gravure coating manner, which can directly adjust and control the dose and thickness of various functional chemicals coated on a surface of the textile. Therefore, the functional chemicals are uniformly coat on the surfaces of the textile, and different chemicals on different surfaces are functionally independent and cause no effect with each other.
[0012] It is still further aspect of the present invention to provide a method for treating surfaces of textile, which performs neither pre-processing such as surface activation or modification, nor any processing procedure. Instead, a spreading layer with single or multi-functions, such as hydrophobicity, anti-bacteria and hydrophilicity (hygroscopicity), is coated on the surfaces of the textile by a continuous process. Therefore, the investing in equipments is saved, as well as the power source and labor power are consumed less.
[0013] According to the aforementioned aspects of the present invention, the present invention provides a method for treating surfaces of textile, which utilizes a functional compound composition including a functional additive, for example, a polymer with at least one reactive group such as epoxy group, double bond (such as acrylic group, alkenyl group), isocyanate, silane, aziridine (or ethyleneimine), hydroxy group, organic acid and so on, to form a coating solution. According to the desired effect of the coated layer on the textile, the functional additive includes various functional resins(chemicals), for example, a hydrophobic agent, anti-bacterial agent such as organic polymer containing quaternary ammonium salts, or hydrophilic agent such as organic acid salt. The hydrophobic agent may be paraffin, polysiloxane or a fluoride. The viscosity of the spreading solution depends on the thickness of the desired coating layer. The method for treating surfaces of textile disclosed by the present invention is not limited by the viscosity of the coating solution. Even if the coating solution has less viscosity (less than 1000 cp of the viscosity), the gravure meshes is merely adjusted (by selecting the groove shape and gravure roller) to uniformly coat the ultra-thin layer, rather than using a thickening agent to increase the viscosity. The textile may be synthetic fiber fabrics such as knitting, woven and non-woven fabrics.
[0014] Hence, the present invention provides an ultra-thin gravure coating manner to coat the coating solution with functions such as hydrophobicity, anti-bacteria and hydrophilicity (hygroscopicity), which is formed by the polymer composition with the reactive group, on the surface of the textile. After an anchoring manner such as thermal drying, the functional components are fixed on the single or partial surface of the textile, so as to produce a textile that has composite functional surfaces, such as the outer hydrophobic surface and the inner anti-bacterial and hydrophilic (hygroscopic) surface. The present invention is applied not only to products in the prior cloth field, but also to the basic fabric for shoe materials and bags that need hydrophobic surfaces. Under this technology platform, the present invention is supposed to be applied in paper materials, non-woven fabrics and various substrates. This method for treating surfaces of textiles can simplify the treatment process increase the additional value, reduce the production cost, and enhance the value and competitiveness of the industry.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
[0016] FIG. 1 depicts a diagram of the gravure coating apparatus for treating surfaces according to a preferred embodiment of the present invention; and
[0017] FIGS. 2 and 3 show images of fabrics of different materials treated by the treating method according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] For more clarifying the method for treating surfaces of textile of the present invention, the following embodiment are described in detail how the method disclosed by the present invention is applied, and more specifically, the testing result disclosed herein is helpful to comprehend the advantages of the present invention.
[0019] Reference is made to FIG. 1 , which depicts a diagram of the gravure coating apparatus for treating surfaces according to a preferred embodiment of the present invention. The gravure printing apparatus 100 comprises a tank 102 , a gravure roll 104 , a pressure roller 106 and guiding rollers 108 and 110 . A spreading solution 112 with various functions such as hydrophobicity, anti-bacteria and hydrophilicity (hygroscopicity), which is formed by a polymer composition with at least one reactive group, is placed in the tank 102 with an opening, wherein water, alcohol, reactive diluent or other organic hydrocarbon solvent may act as a solvent of the spreading solution 112 , and the reactive group is preferably epoxy group, double bond (such as acrylic, alkenyl group), isocyanate, silane, aziridine (or ethyleneimine), hydroxyl group, organic acid or the like. The gravure roll 104 is disposed above the tank 102 , and the pressure roller 106 is disposed on a side of the gravure roll 104 . A textile 114 , whose surface needs to be treated, is guided by the guiding roller 108 to pass between the gravure roll 104 and the pressure roller 106 , and then guided by the guiding roller 110 to enter into a drying apparatus (not shown) for performing a drying and cross-linking process. A coating thickness of the textile 114 is in a range of about 0.5 mm to 2 mm, and a weight thereof is in a range of about 150 grams per meter (g/m) to about 200 g/m. The textile 114 moves on the apparatus at a speed of 2 meters per minute (m/min) and 10 m/min. The drying apparatus typically works as a thermal drying manner, and a thermal drying temperature is typically at a range of about 80 degrees Celsius (° C.) to 200° C.
[0020] When the gravure roll 104 rotates, the coating solution 112 in the tank 102 is brought to bumps on the surface of the gravure roll 104 , and then is coated on a surface of the textile 114 at a pressing point between the gravure roll 104 and the pressure roller 106 . Typically, the size of the bump on the surface of the gravure roll 104 is in a range of about 40 mesh per square inch (mesh/in 2 ) to 200 mesh/in 2 , and preferably in a range of about 40 mesh/in 2 to 180 mesh/in 2 . A pressure between the gravure roll 104 and the pressure roller 106 is 2 kilograms weight per square centimeter (kgw/cm 2 ) or less. A viscosity of the spreading solution 112 is not limited herein, however, preferably in a range of 10 centipoises (cps) to 10000 cps, and more preferably in a range of 200 cps to 5000 cps. A weight of the polymer composition with the reactive groups, which is brought onto the surface of the textile 114 by the coating solution 112 , is less than 100 g/m 2 . Actually, by applying the gravure coating manner disclosed by the present invention, the weight of the polymer composition with the reactive group is easily achieved to less than 50 g/m 2 .
[0021] The size of bumps on the surface of the gravure roller 104 is able to control the transferred amount of the coating solution 112 . The more the bumps are, the more the coating solution are brought, and vice versa. If a coating solution with less viscosity such as less than 1000 cps is applied, a textile coated with the polymer composition containing 0.5 g/cm 2 to 5 g/cm 2 of the reactive groups can be obtained, and the resultant coating layer is merely 1 μm in thickness.
[0022] The amount of the coating solution coated on the surface of the textile is controlled to be much less, so the problem that the coating solution diffuses to the other surface of the textile is prevented. Therefore, the textile, one surface of which is coated (printed) with hydrophobic coating layer and the other surface of which is coated with hydrophilic (hygroscopic) coating layer, is produced by applying the present method, so as to form the textile with coated layers of composite functions, such as an outer hydrophobic surface and an inner hydrophilic surface.
[0023] Reference is made to FIGS. 2 and 3 , which show images of fabrics of different materials treated by the treating method according to a preferred embodiment of the present invention. The fabrics are woven fabrics of polyester materials, which are 0.35 mm and 0.24 mm in thickness, respectively, and 155 g/m 2 and 136 g/m 2 , respectively. In FIGS. 2 and 3 , the left surfaces 200 and 300 are treated with the hydrophilic (hygroscopic) coating layer, and the right surfaces 202 and 302 are treated with the hydrophobic coating layer. When water drops, the hydrophilic surfaces 200 and 300 make the water drops spread out and diffuse rapidly, but the hydrophobic surfaces 202 and 302 make the water drops gather and water-repellent thereon. Generally, the method for treating surfaces of textile disclosed by the present invention can enhance a textile, a thickness of which is in a range of about 0.5 mm to about 2 mm and a weight of which is in a range of about 120 g/m 2 to 300 g/m 2 , to attain 80 or more in its hydrophobicity. With regard to hydrophilicity (hygroscopicity), a diffusion area of the hydrophilic surface of the textile is more than 1500 mm 2 at 20 seconds. Tab. 1 shows a relationship between the diffusion area and time. The comparative example is a textile without hydrophilic surface treatment, and the experimental embodiment is a textile with hydrophilic surface treatment. It is significantly observed that the textile with hydrophilic surface treatment is three times the diffusion speed of water on the textile without hydrophilic surface treatment. The water absorption of the hydrophilic surface of the textile is 2 seconds or less, and during the drying time of 40 minutes to 60 minutes, more than 93% of the water absorptive amount can be eliminated in such a drying rate.
TABLE 1 Diffusion Area of The Textile (mm 2 ) Diffusion time 5 seconds 20 seconds 3 minutes 4 minutes Comparative 0 69 410 518 Example (Un-treated Textile) Experimental 966 1670 3780 3931 Embodiment
[0024] The polymer with the reactive groups may be chosen from a hydrophilic or hydrophobic polymer, and the polymer itself acts as a carrier for fixing on the textile, and the hydrophobic agent, hydrophilic agent or the anti-bacterial agent can adhere to the polymer. The hydrophobic agent and the hydrophilic agent can enhance the hydrophilicity and hydrophobicity of the same, the anti-bacterial agent can make the textile to generate the function of anti-bacteria, and typically, the anti-bacterial ability is more than 99.9%. In addition, the reactive groups of the polymer anchors in the fibers of the textile, so it is washable and difficult to peel off. The textile is typically washed 18 times or more in average.
[0025] According to the aforementioned description, the present invention provides a method of treating surfaces of textile, which is applied with a gravure coating manner, by adjusting the mesh numbers and the viscosity of the coating(printing) solution with functional resin(chemicals), the amount of the printing solution coated on the surface of the textile is well controlled, so as to prevent from diffusing to the other surface and form the textile with a single or composite functional coating layer. The polymer in the printing solution has the reactive group. After fixing treatment such as thermal drying, the reactive group is fixed in the fibers of the textile, and the polymer with functional resin(chemicals) generates the anchor on the whole or partial surface of the textile product. The drying process is fast, and the fastness and wash durability of the textile with composite functions is greatly enhanced.
[0026] It can be comprehended from the aforementioned preferred embodiment of the present invention, as is understood by a person skilled in the art, the foregoing preferred embodiments of the present invention are illustrated of the present invention rather than limiting of the present invention. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structure.
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A method for treating surfaces of textile is disclosed. A coating solution, in which a polymer with reactive groups is utilized to give various functions, such as hydrophobicity, anti-bacteria or hydrophilicity (hygroscopicity) is formed. The coating solution with different viscosities, specially low viscosity, 100 cps or less, can be continuously coated onto a surface of the textile by employing a surface treating technique of gravure coating and appropriately adjusting the gravure meshes. After drying, a highly durable, washable and firm textile with single or multi-functions, such as outer hydrophobic surface and inner anti-bacterial and (or) hydrophilic (hygroscopic) surface.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved decoration for use on packages.
2. Prior Art
Heretofore, there have been proposed such decorations for use on packages, for example as disclosed in Japanese Utility Model publication No. 64-4867, decorations are disclosed which comprise a single belt shaped strip provided with plural holes thereon and a looped elastic string folded and passed through the holes and are capable of forming an imitation flower, bowknot, rosette or the like decorative configuration, with the belt shaped strip squeezed by simply pulling the elastic string.
However, these decorations for packages involve such drawbacks, that, when the decorative configuration of the imitation flower or the like is formed, both ends of the belt shaped strip are positioned on both outsides of the belt shaped strip, with intermediate segments thereof gathered by the string. Thus, there can be produced an unattractive appearance in the decorative configuration of the imitation flower or the like. The more petals the imitation flower or the like has, the more unstability and unhandiness involved there.
The present invention is aimed at overcoming these drawbacks involved in the prior art decorations for use on packages.
SUMMARY OF THE INVENTION
For the purpose of achieving the above object, the improved decoration for use on packages according to the present invention comprises, a belt shaped strip with plural segments longitudinally interconnected both edges segments rounded out in substantially in symmetry and a looped elastic string folded and passed through plural holes provided on suitable positions of the belt shaped strip. A decorative configuration provided on one end segment alone and consisted of at least two decorative pieces, the decorative configuration being formed only on one side of the segment with respect to the longitudinal axis of the belt shaped strip.
The end decorative configuration is formed on one side with respect of the longitudinal axis of the belt shaped strip and is formed with the decorative pieces radially diverged and is positioned substantially perpendicular or parallel to the longitudinal axis of the belt shaped strip. A small hole is bored on a joint portion of the decorative pieces of the end segment for passing therethrough a looped elastic string.
The belt shaped strip may be formed with two or more segments interconnected that are rounded out, like a bulged. When such a strip composed of three or more segments is to be formed, it is preferred to employ segments that successively become larger or smaller from one end to the other so that there may be formed in combination a decorative configuration of imitation flower having many petals. With small holes bored at each side on the center portion of the segments of the belt shaped strip, there can be provided decorative pattern having more varied configuration.
When forming the belt shaped strip with many segments and varying the manner of interconnection, there can be provided decorations for use on packages which are varied and of good appearance. For example, the belt shaped strip may be composed of two pairs of segments, each pair having two segments, of the same size, the respective sizes of the both pairs of segments being such that one pair of segments, having the end decorative pieces provided thereon has larger size than such of the other pair and those pairs of segments are arranged perpendicular to each other, bent at a joint portion of the both pairs.
The belt shaped strip may also be composed of ten segments all of the same size and divided into three pairs respectively, having four, four and two segments, the three pairs being arranged substantially to form a triangular shape, bent at joint portions thereof, with the decorative pieces provided on a free end of one pair with two segments being arranged to extend respectively along the axial directions of such one pair.
The belt shaped strip may likewise be composed of twelve segments all of the same size and divided into three pairs, respectively, having four, four and four segments, such pairs being arranged, respectively, to intersect at an angle of 120 degrees bent at the joint portions thereof.
The looped elastic string is folded and passed through the holes provided on the belt shaped strip and then unremovably held at one end, lest the one end should be slipped out of the end hole where it is unremovably held. The means for unremovably holding the one end may be a knot formed by fastening the folded elastic string together as illustrated in the Japanese Utility Model Publication No. 64-4867. However, it is also convenient that a button-like or disk-like stopper, as shown in FIG. 1, is fixed on one end of the looped elastic string, with the stopper per se serving as a decorative configuration.
The manner of passing the looped elastic string through the holes of the belt shaped strip may be any one that is capable of serving to form a desired decorative configuration thereby.
Materials to be used for the belt shaped strip may be any kind of sheet, as heretofore in use, made of a paper, metallic film, plastic film, woven fabric, unwoven fabric or other flexible sheet.
As described above, the decoration for use on packages according to the present invention comprises end decorative pieces arranged only on one side, so that such end decorative pieces extend from one side alone when formed into a decorative configuration to produce a good appearance and an advantageous handiness.
Further, by varying the manner of interconnection of the segments of the belt shaped strip, there can be provided various types of decorative configurations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a developed plan view of a decoration for use on package according to one embodiment of the present invention;
FIG. 2 is a plan view of the decoration of FIG. 1 as shown in completed form by gathering the segments thereof;
FIG. 3 is a developed plan view of a decoration for use on package according to another embodiment of the present invention;
FIG. 4 is a plan view of the decoration of FIG. 3 as shown in completed form by gathering the segments thereof;
FIG. 5 is a developed plan view of a decoration for use on package according to a further embodiment of the present invention;
FIG. 6 is a plan view of the decoration of FIG. 5 as shown in completed form by gathering the segments thereof;
FIG. 7 is a developed plan view of a decoration for use on package according to a still further embodiment of the present invention;
FIG. 8 is a plan view of the decoration of FIG. 7 as shown in completed form by gathering the segments thereof;
FIG. 9 is a developed plan view of a decoration for use on package according to a further embodiment of the present invention;
FIG. 10 is a plan view of the decoration of FIG. 9 as shown in completed form by gathering the segments thereof;
FIG. 11 is a developed plan view of a decoration for use on package according to a still further embodiment of the present invention;
FIG. 12 is a plan view of the decoration of FIG. 11 as shown in completed form by gathering the segments thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described in more detail with reference to the accompanying drawings illustrating several embodiments thereof. First referring to FIG. 1 which shows a first embodiment of the present invention, a belt shaped strip 1 is composed of two segments 1a, 1b longitudinally interconnected, each being in the form of a bulge rounded out on both edges in symmetry. There are formed two decorative pieces 2a, 2b on one end of the belt shaped strip 1. These decorative pieces 2a, 2b are arranged substantially in V-shaped form while perpendicularly intersecting as a whole with the longitudinal axis of the belt shaped strip 1 with their joint portion located at one end of the strip 1. On a center portion of the belt shaped strip 1 where the end decorative pieces 2a, 2b are formed, there is bored a small hole 3a for passing a looped elastic string 4 therethrough.
The belt shaped strip 1 is constricted in V-shaped form at the constricting portion of the segments 1a, 1b, and there is provided another small hole 3b for passing the looped elastic string 4 therethrough at such center portion of the belt shaped strip 1 as corresponding to the constricted connecting portion. In addition, at the outer end of the segment 1b, the segment without the end decorative pieces 2a, 2b, there is further bored a small hole 3c for passing the looped elastic string 4 therethrough.
The front end on the side of the small hole 3c of the looped elastic string 4 is provided with a button-like stopper 5.
The looped elastic string 4 may be passed through the holes 3a, 3b and 3c in the opposite direction to the illustrated so that the stopper 5 may be positioned at the side of the small hole 3a.
On the upper edge in FIG. 1 of the segment 1b is provided in place a bulge-like decorative piece 6 as an accent for the decoration. Such accent may be suitably selected from various forms, for example, those of a star and animal besides the illustrated and it may be omitted.
The decoration for use on packages which is illustrated in FIG. 1 as the first embodiment of the present invention can be completed to a decorative configuration as shown in FIG. 2 by squeezing or gathering with the looped elastic string 4. When completed, the decorative pieces 2a, 2b are naturally positioned on one side of the belt shaped strip thus folded or gathered and therefore the completed decoration as a whole provides a good appearance, stability and handiness no matter which side of the completed decoration, viz., the side with the decorative pieces 2a, 2b or the other side, is displayed obversely.
In FIG. 3, another embodiment of the present invention is illustrated. In this embodiment, the belt shaped strip 1' is composed of six segments 1a' 1b' 1c' 1d' 1e' and 1f' longitudinally interconnected. These segments are successively formed to become larger from the smallest 1a' to the largest 1f'. End decorative pieces 2a', 2b' are formed on the end of the largest segment 1f' alike those in FIG. 1. There are bored small holes 3a' . . . 3g' for passing a looped elastic string 4' therethrough on respective portions corresponding to the connecting portions of the segments. The completed decoration for use on packages in this embodiment as shown in FIG. 4 provides such a decorative configuration of an imitation flower having many petals, with the end decorative pieces 2a', 2b' protruding from only one side, that produce a good appearance and handiness.
FIG. 5 shows a further embodiment of the present invention. In this embodiment, the segments 1a' . . . 1f' shown in FIG. 3 have pairs of diamond-shaped holes 7a, 7a . . . 7f, 7f respectively bored at upper and lower parts on the central portion of the segments along the longitudinal axis of the belt shaped strip and three end decorative pieces 2a', 2b' and 2c' formed on the largest segment. The belt shaped strip thus formed provides, when completed, such a decorative configuration as shown in FIG. 6 that not only has petals having two cuts on the front end thereof but also end decorative pieces 2a', 2b' and 2c'. Thus, decoration can provide a gorgeous impression as a whole.
In FIG. 7, a still further embodiment of the present invention is illustrated. In this embodiment, the belt shaped strip is composed of two pairs of segments, one with end two segments 1a", and the other with two segments 1b", respectively of the same size. The one pair with end decorative pieces 2a" and 2b"' formed thereon is larger than the other pair and both pairs are arranged to perpendicularly intersect with each other end to end.
The decoration thus formed provides, when completed, a decorative configuration of an imitation flower as shown in FIG. 8 with the petals crossed per se different from those of the other embodiments.
An embodiment illustrated in FIGS. 9 and 10 is composed of ten segments all of the same size which are divided into three pairs of four, four and two segments that are arranged to substantially constitute a triangular form with each pair interconnected end to end, and such end decorative pieces 2a'", 2b'" are formed on the free end of the one pair having the segments 1',", 1'" that extend in the direction of the longitudinal axis thereof. The decoration of this embodiment provides when completed such a decorative configuration of an imitation flower with five petals shown in FIG. 10.
A further embodiment of the present invention as shown in FIGS. 11 and 12 is composed of twelve segments all of the same size which are divided into such three pairs all of four segments that are arranged to intersect in an angle of about 120 degree with each other end to end and when completed it provides a flower-like decorative configuration with six petals, as shown in FIG. 12. In this embodiment, near by a joint portion of the end decorative pieces 2a'", 2b'" to the belt shaped strip is provided such a tongue 8 in the form of a tadpole that extends in the direction opposite to said decorative pieces and has a meandering tail 8', and in the other hand, a V-shaped slit 9 is provided on the connecting portion of said decorative pieces. This tongue 8 serves to cover one end of the looped elastic string 4"" passed through the end small hole when the decoration is completed, with the meanderings tail portion 8' inserted into the V-shaped slit 9. Thus, unlike that shown in FIG. 9, the front end of the looped elastic string 4"" which is protruded from the small hole is not exposed outside and there can be kept a good appearance of the decorative configuration.
Manner of completion and use of the decoration for use on packages according to the present invention only requires, like with the conventional decoration of the same type, such a single operation that squeeze the belt shaped strip by gathering the segments thereof using the looped elastic string which is thereafter hung on the package to be decorated therewith.
The means to be provided on the looped elastic string for the prevention of the slipping out thereof may be selectively provided on one end with the decorative pieces formed thereon of the belt shaped strip or on the other end without such pieces, depending on, when the decoration is completed, which side thereof is exposed outside, one or the other with o without the decorative pieces.
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An improvement in a decoration consisted of a belt shaped strip with plural segments longitudinally interconnected both edges of which segments are rounded out in substantially in symmetry and a looped elastic string folded and passed through plural holes provided on suitable positions of the belt shaped strip, the improvement comprising a decorative configuration provided on one end segment alone and consisted of at least two decorative pieces, said decorative configuration being formed only on one side of the segment with respect to the longitudinal axis of the belt-shaped strip.
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[0001] Priority to German Patent Application No. 102 33 491, filed Jul. 24, 2002, and to U.S. Provisional Patent Application No. 60/399,581, filed Jul. 30, 2002, is hereby claimed. Both of these applications are hereby incorporated by reference herein.
BACKROUND INFORMATION
[0002] The present invention relates to a device for imaging a printing form, including a number of light sources as well as imaging optics for producing a number of image spots of the light sources on the printing form, the imaging optics including at least one macro-optical system of refractive optical components.
[0003] In order to pattern printing forms, in particular printing plates, into ink-accepting and ink-repelling regions, the printing form surface, which is initially in an unpatterned, for example, ink-accepting state, is often partially exposed to the influence of electromagnetic radiation, in particular heat or light of different wavelengths, so as to produce the other, for example, ink-repelling state at the affected positions. To image a printing form selectively, accurately and rapidly, a number of individually addressable light sources, in particular laser light sources, that are arranged in an array in rows or in the form of a matrix are often used in parallel operation, the light sources being projected through imaging optics onto the surface of the printing form, which is located in the image field of the imaging optics.
[0004] In this context, a number of requirements for the fulfillment of various functionalities are placed on an imaging optical system in such a device for imaging a printing form, whether in a printing form imaging unit or in a printing unit. First of all, a part of the imaging optics is intended for globally projecting the number of light sources to image spots with as few imaging defects as possible. In the context of description, this part is referred to as “macro-optics” or “macro-optical system”. Secondly, further parts of the imaging optics or parts of the macro-optics itself can fulfill additional functionalities, such as a possibility of adjusting the focus position.
[0005] Frequently, the light source arrays are composed of a certain number of individually addressable diode lasers, preferably single-mode diode lasers, which are arranged on a semiconductor substrate at certain intervals, typically at equal, i.e. substantially equal, intervals, and which have a common output plane that is precisely defined by the crystal fracture plane (IAB, individually addressable bar). Since the light-emission cones of these diode lasers have different opening widths in the two essentially orthogonal planes of symmetry, there is a need for optical correction to reduce the asymmetric divergence of the emerging light. The ratio of opening angles can be adjusted individually. This correction is carried out with respect to the individual light sources using a part of the imaging optics that is also referred to as “micro-optics”.
[0006] A number of imaging optics which were designed especially for projecting diode laser rows in order to image an image carrier are known from the prior art. For example, U.S. Pat. No. 4,428,647 describes an imaging device including a semiconductor laser array whose individual lasers each have associated therewith a nearby lens for correcting divergence. The light of the semiconductor lasers is then collected by an objective lens and focused onto an image carrier. An imaging device having an individually addressable diode laser array is known from European Patent Application No. EP 0 878 773 A2. The imaging optics has a micro-optical part and a macro-optical parts. The macro-optical part is a confocal lens arrangement that is telecentric on both sides. Prior German Patent Application No. DE 101 15 875.0 describes an imaging device having an array of light sources. The imaging optics includes micro-optics which produces virtual intermediate images of the light sources as well as macro-optics which contains a convex mirror and a concave mirror having a common center of curvature, a combination of the so-called “open type” and which produces a real image of the virtual intermediate images.
[0007] The approaches known from the prior art have in common that they require a large installation space compared to their functionalities. Modification or complementation with further functionalities can only be achieved with difficulty. Since, first of all, the installation space in such machines is very limited and, secondly, the design or configuration of the printing form imaging unit or of the printing unit can be modified only slightly for implementing an imaging device, it is necessary to reduce the installation space requirement without limiting the necessary functionalities. Moreover, an imaging optical system on a printing press or on a printing form imaging unit is subject to shocks or vibrations, which is why optical systems known from the prior art can generally not easily be transferred for use on a printing form imaging unit or inside a printing unit of a printing press.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a compact device for imaging a printing form which allows easy integration into the available installation space in a printing unit of a printing press.
[0009] According to the present invention, a device for imaging a printing form has a number of light sources as well as imaging optics for producing a number of image spots of the light sources on the printing form. The imaging optics includes at least one macro-optical system of refractive optical components or optical elements, in particular, a number of lenses, which is traversed twice by the optical path from the light sources to the image spots. In the context of this description, the word “optical path” is understood to mean all the optical paths of the number of light sources. In particular, the refractive optical components are passed through twice. It is the refractive optical components that substantially contribute to the generation of the number of image spots. Since the optical path passes through the macro-optics multiple times or repeatedly, the macro-optics can have a more compact and installation-space saving design compared to macro-optics having a simple optical path, while maintaining the same functionality. The number of light sources can also be 1; preferably, however, provision is made for a plurality of light sources. The light sources can be arranged in a one-dimensional array (line, preferred) or in a two-dimensional array, in particular in a regular array, preferably in a Cartesian arrangement. The light sources and the image spots are in a one-to-one functional relationship with each other. The image spots are disjunct from each other. It is possible for the image spots to be dense or, preferably, not to be dense with respect to each other; that is, their spacing can be greater than the minimum spacing of the printing dots to be placed. The spacing of neighboring image spots on the printing form in units of the minimum printing dot spacing is preferably a natural number that is relatively prime to the number of image spots (light sources). The printing form is preferably an offset printing form.
[0010] In this context, the optical path can run non-centrally through the macro-optics. In particular, the optical path can be different on the first path through the macro-optics than on the second path through the macro-optics. Moreover, the optical path can run symmetrically to the optical axis of the macro-optics. In particular, the first path can run symmetrically to the second path.
[0011] The double passage of the optical path through the macro-optics can be such that the first principal plane and the second principal plane of the macro-optics are located on one side of the macro-optics. The macro-optics can be designed in such a manner that objects (a number of light sources) and images are located on one side of the macro-optics. In other words, the optical path passes through the macro-optics on a first path in a first direction and on the second path in a direction opposite to the first direction.
[0012] In an advantageous embodiment of the device for imaging a printing form, at least one mirror, in particular a plane mirror, is associated with the macro-optics. The macro-optics can be designed in such a manner that the optical path passes through the macro-optics in a first direction on its first path until the light hits the at least one mirror, whereupon it passes through the macro-optics in a direction opposite to the first direction on its second path. The macro-optics is virtually equal to an optical system of double the size. In other words, a macro-optical system composed of a number of optical elements is optically doubled in size or doubled by the mirror or mirrors; the mirror or mirrors reflecting the light into a symmetrical second passage through the macro-optics.
[0013] In a device according to the present invention for imaging a printing form, the macro-optics can include at least one part that is designed as an adaptive optic, or at least one of the associated mirrors can be designed to be adaptive. In particular, at least one of the associated mirrors can be designed as an adaptive mirror, i.e., with a variable radius of curvature or with a variable surface structure. By varying the radius of curvature, it is possible to change the image width. A variation of the radius of curvature is small compared to the dimensions of the adaptive mirror. The adaptive mirror can also enable the wavefront of the light to be manipulated on the optical path through the macro-optics, for example, to achieve an axial change in focusing/defocusing. The adaptive mirror can be an adjustable element for compensating imaging defects. An adaptive mirror can be a membrane mirror, an electrostatic mirror, a bimorph mirror, a piezoelectrically driven (for example, polish-milled) metal mirror, or the like.
[0014] In an advantageous embodiment of the device according to the present invention for imaging a printing form, the macro-optics can include at least one movable lens, or, alternatively, a movable mirror. The movable lens is preferred, in particular because the telecentricity of macro-optics is maintained although the lens is moved. When the printing form or printing plate is clamped to a cylinder, the attachment often causes a disturbing curvature (“plate bubble”), which can be on the order of several 100 micrometers. Due to the curvature, it is possible for the printing form surface to come to rest outside the usable focal range of the laser radiation so that the power density of the laser radiation at such a distance from the focus position is not sufficient to achieve an acceptable imaging result. A movable lens in the macro-optic makes it possible for the focus position of the laser radiation to be moved (refocused) in the direction of the optical axis in a simple manner. The accuracy requirements for this refocusing result from the depth of focus of the laser beams. The device according to the present invention allows easy integration of the functionality of focus displacement. The device has a defined distance between the last optical component and the printing form, the distance remaining unchanged by the focus displacement. At the same time, it is possible to obtain a good ratio between the displacement of the movable lens and the focus position variation.
[0015] In an advantageous embodiment of the device for imaging a printing form, the light sources are individually addressable lasers. Each light source corresponds to an individually addressable imaging channel having one imaging beam. In particular, the light sources can emit in the infrared (preferred), visible, or ultraviolet spectral ranges. In an advantageous refinement, the lasers can be tunable and/or operated in pulsed mode in the nanosecond, picosecond, or femtosecond regime. The individually addressable lasers can be, in particular, diode lasers or solid lasers. The individually addressable lasers can be integrated on one or more bars, which, in particular, can be one or more individually addressable bars (IAB), preferably single-mode. A typical IAB includes 4 to 1,000 lasers, in particular, 30 to 260 lasers. The lasers are located on the IAB preferably at substantially equal intervals, in particular in a line (one-dimensional array) or on a grid (two-dimensional array).
[0016] In the device according to the present invention for imaging a printing form, a micro-optical system can be arranged downstream of the number of light sources along the optical path, the micro-optics being arranged upstream of the macro-optics along the optical path. For diode lasers, in particular on a bar, the micro-optics can be used, inter alia, for adjusting the beam diameters. Due to the very small diameters of the individual laser beams at the front of the IAB, typically a few micrometers in the horizontal direction (slow axis) and a few micrometers in the vertical direction (fast axis), the beam diameters need to be adjusted in both axes independently of each other in order to achieve the diameters needed on the printing form, typically a few micrometers in the horizontal or vertical directions. The aim is to obtain fundamental mode Gaussian laser beams that are as ideal as possible, because these have the greatest natural depth of focus and, thus, are maximally insensitive to shifts in focus or “plate bubbles”. The lasers are preferably operated in single mode. A micro-optics can be arranged downstream of the individually addressable lasers, allowing the beam diameters of the light beams emerging from the lasers to be influenced in two orthogonal axes independently of each other, i.e. to be adjusted independently of each other. The image spots of the micro-optics (intermediate image) can be real or virtual. In particular, the micro-optics can be produce a virtual, enlarged intermediate image of the number of light sources that is projected by the macro-optics.
[0017] In the device according to the present invention for imaging a printing form, it is particularly advantageous if the light of the number of light sources is coupled into the macro-optics via at least one light-deflecting element. This measure makes it possible to make the design even more compact. As an alternative to a mirror pair, it is possible and preferred to use a Porro prism as the light-deflecting element to couple the light of the number of light sources into the macro-optics. Using a Porro prism, it is also possible to adjust the optical path through the macro-optics.
[0018] In an advantageous embodiment, the macro-optics of the device according to the present invention is telecentric on both sides. In this connection, it should be pointed out that during focusing, for example, using an adaptive mirror or a movable lens in the macro-optics of the device according to the present invention, the telecentricity is maintained. In other words, the object-to-image distance is changed by the focus displacement described in detail above, while the object distance is fixed. Using an optical path that is telecentric over the whole extent, it is achieved that the size of the image is not changed or changed only within very small tolerances of typically ±1 micrometers in the directions orthogonal to the beam propagation (optical axis). Moreover, the macro-optics can advantageously be designed to allow imaging essentially without changing the size, i.e. 1:1 imaging. The focal length of the macro-optics is preferably infinite.
[0019] In an advantageous embodiment of the device according to the present invention, correction optics for adjusting the image size can be arranged downstream of the macro-optics along the optical path. The correction optics permits very high positional accuracy of the image spots and preferably also a very accurate adjustment of the image size. Preferably, the correction optics is a zoom lens system of two lenses. The zoom lens system itself is telecentric on both sides, just as the macro-optics. The telecentricity is maintained during adjustment of the image size.
[0020] In an advantageous embodiment of the device according to the present invention, neighboring image spots of the number of image spots of the light sources on the printing form can have a substantially equal distance a, i.e. equal distance a, which is a whole-number multiple of minimum printing dot spacing p. In particular, the number of light sources can advantageously be n, with n being relatively prime to the number (a/p), so that a non-redundant interleaving method can be carried out for imaging the printing form. Obviously, n and (a/p) are not both 1 simultaneously.
[0021] In a preferred embodiment of the device according to the present invention for imaging a printing form, the printing form to be imaged can be mounted on a rotatable cylinder. Alternatively, the surface of a rotatable cylinder can constitute a printing form. In other words, the printing form can be a plate-shaped printing form (having one edge) or a sleeve-shaped printing form (having two edges). It can be a (conventional) printing form that can be written once, a recoatable or a rewritable printing form. In the context of this description of the device according to the present invention, “printing form” is understood to include also a so-called “digital printing form”. A digital printing form is a surface that is used as an intermediate carrier for printing ink before this printing ink is transferred to a printing substrate. In this context, the surface itself can be patterned into ink-accepting and ink-repelling regions, or only be provided with printing ink in a patterned manner through imaging. Interaction with laser radiation allows the digital printing form to be patterned into regions which do or do not deliver the printing ink to a printing substrate or to an intermediate carrier. The patterning of the digital printing form can be carried out prior or subsequent to applying ink to the printing form. The printing form can also be essentially composed of the printing ink itself, for example, for use in a thermal transfer method.
[0022] The imaging device according to the present invention can be used especially advantageously in a printing form imaging unit or in a printing unit of a printing press. A printing unit can contain one or more imaging devices. A plurality of devices can be arranged in such a manner that they can concurrently image partial areas of a printing form. A printing press according to the present invention, which features one or more inventive printing units can be a web-fed or sheet-fed press. A sheet-fed press can typically include a feeder, a delivery, and one or more finishing stations, such as a varnishing unit or a dryer. A web-fed printing press can have a folding apparatus arranged downstream. The underlying printing method of the inventive printing unit or of the inventive printing press can be a direct or indirect planographic printing method, a flexographic printing method, an offset printing method, a digital printing method, or the like.
[0023] Also related to the inventive idea is a method for changing the relative position of an image spot with respect to the position of a printing form in a device for imaging a printing form, including a number of light sources as well as imaging optics for producing a number of image spots of the light sources on the printing form, the imaging optics including at least one macro-optical system. The method according to the present invention has the feature that a lens of the macro-optics that is traversed twice by the optical path is moved. When using macro-optics which is traversed twice by the optical path, the object-to-image distance can be changed by moving a lens in the macro-optics, while the object distance is fixed. Advantageously, the telecentricity is maintained. The method according to the present invention can preferably be carried out using a device for imaging a printing form, such as is described in this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Further advantages as well as expedient embodiments and refinements of the present invention will be depicted by way of the following Figures and the descriptions thereof. Specifically,
[0025] [0025]FIG. 1 shows a preferred embodiment of the imaging optics of the device according to the present invention for imaging a printing form;
[0026] [0026]FIG. 2 shows a preferred embodiment of the micro-optics of the device according to the present invention for imaging a printing form, with Subfigure A in the vertical plane and Subfigure B in the horizontal plane;
[0027] [0027]FIG. 3 is a schematic representation of an advantageous embodiment of the device according to the present invention for imaging a printing form on a printing form cylinder; and
[0028] [0028]FIG. 4 is a schematic representation of an advantageous embodiment of the device according to the present invention for imaging a printing form in a printing unit of a printing press.
DETAILED DESCRIPTION
[0029] [0029]FIG. 1 shows a preferred embodiment of the imaging optics of the device according to the present invention for imaging a printing form. Along optical path 22 , starting at the number of light sources 14 , in a preferred embodiment an individually addressable diode laser bar (IAB), imaging optics 18 includes micro-optics 34 , a Porro prism 48 , macro-optics 20 , i.e. a lens system producing a 1:1 image, and correction optics 50 . Imaging optics 18 produces a number of image spots 16 of the number of light sources 14 . At the top left of FIG. 1, a scale in millimeters is added for quantitative purposes.
[0030] Using micro-optics 34 , the beam diameters can be influenced independently of each other in the two orthogonal directions perpendicular to the propagation direction (optical axis). The micro-optics makes it possible to adjust the size of the spots to be imaged. FIG. 2 serves to illustrate in more detail micro-optics 34 , which includes a fast-axis lens 36 and a slow-axis lens 38 . The number of light sources 14 and micro-optics 34 can also be enclosed in a common housing. Porro prism 48 , or alternatively two mirrors, is used to couple the light into the multiple-lens 1:1 lens system of macro-optics 20 and to align the beams in the image plane. Inner surfaces of Porro prism 48 serve as light-deflecting elements 46 through total reflection. Macro-optics 20 includes a first lens 56 , a second lens 58 , a third lens 60 , a fourth lens 62 , a fifth lens 64 , a movable lens 32 (the moving direction is indicated by the double arrow), and a mirror 30 . The lenses of the macro-optics and mirror 30 are arranged axisymmetrically around the optical axis 24 . Optical axis 22 does not run along optical axis 24 , but non-centrally or off-axis. Using mirror 30 , which is preferably provided with a highly reflective coating, the light is reflected and passes through micro-optics 20 again; however, in such a manner that it is symmetrically mirrored on optical axis 24 with respect to the first path. In other words, optical path 22 runs through macro-optics 20 such that it is folded. First principal plane 26 and second principal plane 28 of the macro-optics are located on one side of macro-optics 20 , in particular, symmetrically. In the preferred embodiment shown in FIG. 1, a Porro prism 48 is arranged upstream of macro-optics 20 . In consequence, spots of mirrored principal plane 27 , in which are located light sources 14 , are imaged onto second principal plane 28 of macro-optics 20 . To adjust the focus position of image spots 16 , the object-to-image distance of macro-optics 20 , which is traversed twice by the optical path, is changed in a controlled manner. In this embodiment, this is done by moving movable lens 32 . Due to the double passage and the suitable design of macro-optics 20 , a good ratio between the displacement of movable lens 32 and the change in the focus position of image spots 16 is achieved; a displacement by s results in a change by m*s, with m>>1. The optical path through macro-optics 20 is telecentric. In the embodiment shown in FIG. 1, telecentric correction optics 50 including a first lens 52 and a second lens 54 is arranged downstream of macro-optics 20 for fine correction. Correction optics 50 is a two-lens zoom lens system which allows stepless adjustment of the image size in a range of plus or minus a few percent, approximately from 0.9 to 1.1.
[0031] [0031]FIG. 2 shows a preferred embodiment of the micro-optics of the device according to the present invention for imaging a printing form. Subfigure A shows a view in the vertical plane in vertical direction 42 and with horizontal direction 40 out of the plane of paper, while Subfigure B shows a view in the horizontal plane in horizontal direction 40 and with vertical direction 42 into the plane of paper. At the top left of FIGS. 2A and 2B, a scale in millimeters is added for quantitative purposes. In a preferred embodiment, micro-optics 34 is composed of a fast-axis lens 36 and a slow-axis lens 38 . Fast-axis lens 36 is a glass fiber which is polished on one side and reduces the divergence of all beams of the number of light sources 14 in the fast axis thereof. Slow-axis lens 38 is an array of a number of cylindrical lenses whose number corresponds to the number of light sources, each individual lens reducing the divergence of the beams of the light source 14 that is associated with the lens. Micro-optics 34 is designed in such a manner that a virtual intermediate image 44 is produced.
[0032] [0032]FIG. 3 relates to a schematic representation of an advantageous embodiment of the device according to the present invention for imaging a printing form on a printing form cylinder. FIG. 3 shows a device for imaging 10 a printing form 12 which is mounted on a printing form cylinder 66 . The beams of a number of light sources 14 , here individually addressable diode lasers on a bar, are shaped by micro-optics 34 and subsequently coupled a into macro-optics 20 having a mirror 30 via a Porro prism 48 . Optical path 22 passes through macro-optics 20 twice and then passes through correction optics 50 . Light sources 14 are projected onto image spots 16 on printing form 12 . A triangulation sensor 68 is integrated for determining the position of printing form 12 compared to the focus position of the imaging optics of the imaging device 10 . Sensor light 70 is reflected at the surface of printing form 12 , so that it is possible to determine the distance. The surface of the printing form can have marked curvatures on the order of several 100 micrometers (“plate bubbles”) so that the focus position is changed using movable lens 32 . Triangulation sensor 68 can make a measurement at a point of printing form 12 which is reached in the image field of image spots 16 only at a later time by rotation of printing form cylinder 66 in direction of rotation 80 . This point can also be offset from image spot 16 along the axis of printing form cylinder 66 . The number of light sources 14 is connected to a laser driver 72 which is operatively connected to a control unit 74 .
[0033] [0033]FIG. 4 shows a schematic representation of an advantageous embodiment of the device according to the present invention for imaging a printing form in a printing unit of a printing press. In a printing unit 88 of a printing press 90 , an imaging device 10 according to the present invention is associated with a printing form 12 on a printing form cylinder 66 . By way of example, three imaging beams 76 produce three image spots 16 in an image field 82 on printing form 72 . Printing form cylinder 66 is rotatable about its axis 78 in direction of rotation 80 ; imaging device 10 is movable in direction of translation 86 parallel to axis 78 . The unfolding line running through image spots 16 is preferably oriented substantially parallel to axis 78 of printing form cylinder 66 . Printing dots are produced on printing form 12 by image spots 16 which are passed over the two-dimensional surface of printing form 12 along helical paths 84 (helices) through the interaction of the rotation of printing form cylinder 66 and the translation of imaging device 10 .
[0034] The advance in direction of translation 86 and the rotation in direction of rotation 80 are preferably coordinated in such a manner that printing form 12 is traversed in a non-redundant manner, but in such a way that it is possible to place dense printing dots. In order to pass a number of imaging beams 76 (independently of whether they are arranged on one or on several imaging devices) in a non-redundant manner over the locations of a two-dimensional surface of a printing form 12 on which printing dots are to be placed by image spots 16 , it is required to observe certain advance rules for the passage of positions (locations) that are imaged in a preceding step with respect to positions (locations) that are imaged in a subsequent step. These advance rules must be strictly complied with, especially if in an imaging step, n imaging beams 76 place n printing dots at positions (locations) which are not dense on printing form 12 , i.e., whose distance is not the minimum printing dot spacing p (typically 10 micrometers). When looking at an azimuth angle of the printing form, then dense imaging can be achieved if printing dots are placed between already imaged printing dots in a subsequent imaging step. This procedure is also known by the term “interleaving method” (interleaving). An interleaving method for imaging a printing form is characterized, for example, in German Patent Application No. DE 100 31 915 A1 or in U.S. Patent Applicaton No. US2002/0005890A1, the disclosures of which are incorporated herein by reference. For a given minimum printing dot spacing p, for a row of n imaging channels on an unfolding line which are equally spaced and whose neighboring image spots on the printing form have a distance a which is a multiple of minimum printing dot spacing p, a non-redundant advance by a distance (np) in the direction of the unfolding line is ensured when n and (a/p) are relatively prime. The observance of an interleave advance rule results in interleaved helical paths 84 of the image spots. Along the unfolding line of an azimuth angle, image spots 16 are placed on helical paths 84 between image spots 16 of other helical paths 84 , which were already placed at a previous point in time. In a printing unit 88 according to the present invention, a printing form 12 is imaged using imaging device 10 according to the present invention, preferably in an interleaving method, in particular in the interleaving method described in German Patent Application No. DE 100 31 915 A1.
[0035] List of Reference Numerals
[0036] [0036] 10 imaging device
[0037] [0037] 12 printing form
[0038] [0038] 14 number of light sources
[0039] [0039] 16 image spot
[0040] [0040] 18 imaging optics
[0041] [0041] 20 macro-optics
[0042] [0042] 22 optical path
[0043] [0043] 24 optical axis
[0044] [0044] 26 first principal plane
[0045] [0045] 27 mirrored principal plane
[0046] [0046] 28 second principal plane
[0047] [0047] 30 mirror
[0048] [0048] 32 movable lens
[0049] [0049] 34 micro-optics
[0050] [0050] 36 fast-axis lens
[0051] [0051] 38 slow-axis lens
[0052] [0052] 40 horizontal direction
[0053] [0053] 42 vertical direction
[0054] [0054] 44 virtual intermediate image
[0055] [0055] 46 light-deflecting element
[0056] [0056] 48 Porro prism
[0057] [0057] 50 correction optics
[0058] [0058] 52 first lens of the correction optics
[0059] [0059] 54 second lens of the correction optics
[0060] [0060] 56 first lens of the macro-optics
[0061] [0061] 58 second lens of the macro-optics
[0062] [0062] 60 third lens of the macro-optics
[0063] [0063] 62 fourth lens of the macro-optics
[0064] [0064] 64 fifth lens of the macro-optics
[0065] [0065] 66 printing form cylinder
[0066] [0066] 68 triangulation sensor
[0067] [0067] 70 sensor light
[0068] [0068] 72 laser driver
[0069] [0069] 74 control unit
[0070] [0070] 76 imaging beam
[0071] [0071] 78 axis of the printing form cylinder
[0072] [0072] 80 direction of rotation
[0073] [0073] 82 image field
[0074] [0074] 84 path of the image spots
[0075] [0075] 86 direction of translation
[0076] [0076] 88 printing unit
[0077] [0077] 90 printing press
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A compact device for imaging ( 10 ) a printing form ( 12 ), including a number of light sources ( 14 ) as well as imaging optics ( 18 ) for producing a number of image spots ( 16 ) of the light sources ( 14 ) on the printing form ( 12 ), the imaging optics ( 18 ) including at least one macro-optical system ( 20 ) of refractive optical components ( 32, 56, 58; 60, 62, 64 ), the imaging device having the feature that the optical path ( 22 ) from the light sources ( 14 ) to the image spots ( 16 ) passes through the macro-optics ( 20 ) twice. The installation-space saving imaging device ( 10 ) can be used in a printing unit ( 88 ) of a printing press ( 90 ).
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CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims the benefit of U.S. Provisional Application No. 60/318,233 filed on Sep. 7, 2001.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an apparatus for insertion into a manhole. More particularly, the present invention relates to an apparatus which is inserted into a manhole to prevent water leakage into the manhole.
[0003] Most cities and municipalities typically have two separate sewer systems, a sanitary sewer system and a storm water sewer system. The sanitary sewer system is designed to accept water that is discharged from homes and business including, but not limited to, water that is used in the toilet, cooking, bathing and washing clothes. All of the water that enters the sanitary sewer system is treated in a waste water treatment facility prior to being discharged into the environment.
[0004] The storm water sewer system is designed to accept large quantities of water from rainfall and melting snow. Typically, the water entering the storm water sewer is clean and not needing treatment. Therefore, the water transferred through the storm water sewer system is discharged directly into the environment without being treated in the waste water treatment facility.
[0005] Because all the water entering the sanitary sewer system is treated in a waste water treatment facility, municipalities and cities desire to keep the water intended to be transferred by the storm water sewer, which does not require treatment, from entering into the sanitary water sewer. Allowing clean storm water into the sanitary sewer system unnecessarily consumes capacity in the waste water treatment facility while increasing the costs of treating the water. When excessive storm water enters the waste water treatment plant, the waste water treatment plant may not have the capacity to treat the large amount of water causing untreated water, including raw sewage, to be discharged into the environment which can potentially cause an environmental disaster.
[0006] One of the major contributors of clean storm water entering the sanitary sewer is the design of most manhole structures which provide access to the sanitary sewer. The manhole box, typically a junction box, is positioned below ground level and has a through hole in the upper surface. A series of concrete rings called risers are positioned about the through hole on an upper surface of the manhole box. The risers bring the manhole structure up to approximately ground level while providing access to the manhole. A manhole cover frame is positioned on the upper surface of the upper riser such that the upper surface of the frame is at ground level. The manhole cover fits within the frame.
[0007] After the manhole box, the series of risers, the frame, and the cover are placed in the selected positions, the hole is backfilled to secure the structure in position. Water from rain and melting snow runoff can seep through the ground and enter the sanitary sewer system through seams between the manhole box and the first riser, between the seams between the risers, between the top riser and the frame and also between the frame and the manhole cover.
[0008] Besides having to treat clean runoff water in the waste water treatment plant, seepage of water also causes soil erosion around the manhole structure. As water enters into the sanitary sewer system through the manhole structure, the water also carries the surrounding soil into the manhole box. As the soil is eroded from around the manhole structure, a cavity is formed which over time will cause the soil above the cavity to collapse. When the soil collapses around the manhole cover, the surface needs to be filled in which adds additional repair expenses to the city or municipality.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention includes a device from preventing water from entering a manhole. The device includes a body having first and second portions that are integrally formed. The first portion extends along and above a periphery of the opening of the manhole and the second portion extends upwardly from the first portion and provides access to the opening of the manhole. Preferably, the first portion includes a downwardly extending lip disposed along an outer vertical surface of the manhole. In addition, a cap is positionable on the second portion to prevent water entering the manhole from the manhole's opening.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a partial sectional view of the present invention disposed within a manhole.
[0011] [0011]FIG. 2 is a perspective view of the insert of the present invnetion disposed on an upper surface of a box of a manhole.
[0012] [0012]FIG. 3 is a perspective view of a plurality of risers disposed on an upper surface of the insert wherein the plurality of concrete risers are disposed about the chimney of the insert.
[0013] [0013]FIG. 4 is an alternative to concrete risers where a form is disposed about the insert where concrete is poured between the insert and the form.
[0014] [0014]FIG. 5 is a perspective view of the insert of the present invention including a manhole cover frame disposed on a top surface of the upper riser.
[0015] [0015]FIG. 6 is an exploded perspective view of the present invention.
DETAILED DESCRIPTION
[0016] The present invention includes a device generally illustrated at 10 in FIG. 1 for use within a manhole assembly 40 . The device 10 prevents leakage of surface water and dirt infiltration into the manhole assembly 40 . The device 10 includes an insert 12 and a cap 14 .
[0017] Referring to FIGS. 1 and 6, the manhole assembly 40 includes a box 42 positioned below ground level 11 . The box 42 has an opening 44 through an upper surface 46 which provides access to an interior 43 of the box 42 . The box 42 can provide access to a utility junction box such as banks of telephone or electric switches as well as sewer systems such as a junction for several pipes in a sewer system.
[0018] Referring to FIGS. 1, 2 and 6 , a bottom surface 18 of a plate 16 of the insert 12 is positioned adjacent the upper surface 46 of the box 42 . A peripheral edge 22 of the plate 16 extends beyond an exterior surface 48 of the box 42 . A first lip 24 extends downwardly from the bottom surface 18 of the plate 16 and preferably along the peripheral edge 22 of the plate 16 such that a distal edge 26 of the first lip 24 is disposed below the upper surface 46 and about the exterior surface 48 of the box 42 . Because the distal edge 26 of the first lip 24 extends below the upper surface 46 of the box 42 , the first lip 24 serves as a water seal diverting water into the soil below the upper surface 46 of the box 42 .
[0019] Extending substantially centrally upwardly from the plate 16 is a chimney 28 having a substantially central passageway 30 aligned with an aperture 32 in the plate 16 and the through hole 44 in the upper surface 46 of the box 42 . The chimney 28 is slightly tapered towards its upper edge 29 primarily for nesting several inserts 12 one on top of each for storage and shipping purposes. Although a chimney 28 having a circular cross-section is preferred, other cross-sectional configurations are within the scope of the invention.
[0020] The insert 12 is preferably of a unitary (integral) construction, molded from a plastic (polymer) such as polyethylene. Polyethylene is very suitable material of construction, being corrosion resistant to sewage gases being produced within the sewer system and to many liquids including water.
[0021] With the insert 12 positioned in a selected position upon the box 42 , at least one concrete riser 50 is disposed about the chimney 28 and adjacent a top surface 17 of the plate 16 as illustrated in FIGS. 1, 3 and 6 . Additional concrete risers 52 , 54 are disposed about the chimney 28 and stacked upon each other such that an upper surface 56 of the upper riser 54 is a selected distance from ground level 11 .
[0022] As illustrated in FIGS. 1 and 6, the central passageway 30 of the chimney 28 forms the entry into the box 42 . The concrete risers 50 , 52 , 54 are also protected from corrosion from sewage gases within the manhole structure 40 due to the polyethylene barrier created by the chimney 28 of the insert 12 . Since the insert 12 is preferably constructed from a plastic, the chimney 28 can easily be cut to a selected height and can be customized for manhole structures of different depths between ground level 11 and the upper surface 46 of the box 42 .
[0023] Referring to FIGS. 1, 5 and 6 , a manhole cover frame 58 is positioned on the upper surface 56 of the upper riser 54 with the upper edge 29 of the chimney 28 of the insert 12 extending within an opening in the manhole frame 58 . Prior to installing a manhole cover 40 within the manhole frame 56 , the cap 14 is positioned over the upper edge 29 of the chimney 28 to provide an additional seal within the manhole structure 40 . The cover 14 has a downwardly extending second lip 34 , preferably about the peripheral edge 15 , where the second lip 34 extends below the upper edge 29 and about an outer surface 27 of the chimney 28 .
[0024] A lifting structure 36 is secured to the cap 14 to aid in positioning the cap 14 over the chimney 28 and removing the cap 14 from the chimney 28 . The lifting structure 36 is preferably an eyescrew.
[0025] With the cap 14 disposed over the chimney 28 , the manhole cover 60 is placed within the manhole frame 58 as illustrated in FIGS. 1 and 6. The void around the manhole structure 40 is backfilled to secure the box 42 , the plurality of concrete risers 50 , 52 , 54 , the manhole frame 58 and the manhole cover 60 into position.
[0026] The device 10 prevents all surface water from leaking or seeping into the box 42 . When water enters through the manhole cover 60 or between the manhole cover 60 and the manhole frame 58 , the water contacts the cap 14 and flows over the second lip 34 , down the outer surface 27 of the chimney 28 , over the upper surface 17 of the plate 16 and down the first lip 24 . After flowing off of the first lip 24 , the water disperses into the soil below the upper surface 46 of the box 42 thereby preventing any water from entering the box 42 .
[0027] When water enters the manhole structure 40 through seams between the risers 50 , 52 , 54 or between the upper surface 46 of the box 42 and the bottom riser 50 , the water runs down the outer surface 27 of the chimney 28 , over the upper surface 17 of the plate 16 and down the first lip 24 . After flowing off of the first lip 24 , the water disperses into the soil without entering the box 42 .
[0028] Because the second lip 34 of the cap 14 is below the upper edge 29 of the chimney 28 , water is prevented from entering between the cap 14 and the insert 12 . Similarly, because the distal edge 26 the first lip 24 of to the plate 16 is below the upper surface 46 of the box 42 , water is prevented from entering between the insert 12 and the box 42 , thereby making the box 42 free from any runoff water.
[0029] Since the runoff water cannot enter into the box 42 , the soil around the manhole structure 40 cannot enter into the box 42 , thereby preventing erosion around the manhole structure 40 . Because there is no erosion around the manhole structure 40 , the maintenance and repair costs are decreased. Additionally, since surface water leakage is eliminated into the sanitary sewer manholes, large amounts of surface water do not have to be processed by the water treatment plant freeing up capacity and reducing treatment costs.
[0030] Alternatively, the manhole structure 40 can be constructed by installing the box 42 and the insert 12 on the upper surface 46 of the box 42 . Instead of placing a plurality of risers 50 , 52 , 54 on top of each other creating seams through which water can seep, a form 62 is placed about the riser 12 as illustrated in FIG. 4. Concrete is poured into a cavity 64 between the form 62 and the insert 12 . After the concrete is set, the form 62 is removed and the manhole frame 58 is placed upon the top surface of the concrete form (not shown). The cap 14 having the second lip 34 is placed on the upper surface 29 of the chimney 28 . With the manhole frame 58 and the cap 14 in the selected positions, the manhole cover 60 is placed within the frame 58 . In the alternative construction, the manhole construction 40 prevents seepage into the box 42 by eliminating the seams between the plurality of risers. Any water that penetrates the concrete form (not shown) flows down the outer surface of the chimney 28 , along the top surface 17 of the plate 16 , down the first lip 24 and into the adjacent soil.
[0031] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A device prevents water from leaking into a manhole. The device includes a body having first and second portions that are integrally formed. The first portion extends along and above a periphery of the opening of the manhole and the second portion extends upwardly from the first portion and provides access to the opening of the manhole. Preferably, the first portion includes a downwardly extending lip disposed along an outer vertical surface of the manhole. In addition, a cap is positionable on the second portion to prevent water entering the manhole from the manhole's opening.
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BACKGROUND OF THE INVENTION
This invention relates to the preparation of elastomeric organopolysiloxanes. This invention further relates to the preparation of elastomeric, heat-resistant organopolysiloxanes which do not revert to lower molecular weight liquids or semi-solids when exposed to elevated temperatures.
It is well known to prepare elastomeric, polymeric organopolysiloxanes by reacting a precondensed organosiloxane of the general formula
XO--Si(R).sub.2 --O-SiR.sub.2 ].sub.n O-Si(R).sub.2 --OX
wherein R is alkyl or aryl, X is hydrogen or alkyl and n represents an integer of 50 or more, with a polyfunctional silicon-containing crosslinking agent such as a tri- or tetraalkoxy silane in the presence of a suitable catalyst. U.S. Pat. No. 3,127,363 discloses that this reaction can be carried out under relatively mild conditions if a filler such as carbon black, one of the various types of clays or diatomaceous earth is present during the reaction of the precondensed organosiloxane with the curing agent. The resultant cured materials are disclosed as being useful for a variety of applications, including sealants, casting compositions, coatings, encapsulants and molding compositions. The aforementioned U.S. Pat. No. 3,127,363 teaches that any of the known catalysts for curing silicone resins can be employed. These catalysts include metal soaps, metal oxides, metal chelates such as chromium acetylacetonate, metal salts of thiols or dithiocarbamic acids, organometallic compounds such as dibutyltin dilaurate and phenyl mercury acetate and basic nitrogen-containing compounds, preferably amines and substituted amines such as triethanol amine. The majority of the examples in this patent employ dibutyltin dilaurate as the catalyst. While this compound and other organotin compounds yield acceptable cured polyorganosiloxane elastomers which retain their initial properties virtually indefinitely at ambient temperatures, polyorganosiloxanes prepared using organotin compounds wherein tin is in a tetravalent state are not stable when exposed to temperatures above about 150° C. At these temperatures the organotin compound catalyzes an irreversible depolymerization to low molecular weight liquid or semi-solid products. Organotin compounds therefore cannot be employed if the cured elastomers are to be exposed to the operating temperatures of high power electronic equipment, which often exceed 150° C.
It is possible to avoid the problem of depolymerization or "reversion" at elevated temperatures by employing a stannous compound such as stannous-2-ethylhexoate in place of an organotin compound. While stannous compounds as a class may be useful for certain applications the catalytic activity of these compounds is so high that even at minimum effective concentrations the working or "pot" life of a catalyzed composition is extremely short and may be as short as five minutes. For certain applications, particularly when thicker sections are desired, stannous compounds as a class cannot be employed. The uppermost layer may cure rapidly to form an impenetrable skin while the lower layers remain uncured or only partially cured.
Surprisingly it has now been found that stannous salts of certain ethylenically unsaturated hydroxycarboxylic acids containing from 10 to about 20 carbon atoms are unique among stannous compounds in that the working life of a typical uncured polysiloxane composition is one hour or more. In addition, the properties of the cured product, including hardness, are equivalent or superior to those obtained using conventional catalysts such as amines and tin compounds.
SUMMARY OF THE INVENTION
The present invention provides an improved method for preparing heat-resistant elastomeric polyorganosiloxanes by reacting (1) as the major component, a linear difunctional polysiloxane of the general formula
XO--Si(R.sup.1).sub.2 --OSi(R.sup.1).sub.2 ].sub.n O--Si(R.sup.1).sub.2 --OX
wherein R 1 is selected from the group consisting of lower alkyl, aryl and halomethyl, X is hydrogen or R 1 and n is an integer greater than 50, (2) as the crosslinking agent a compound of the general formula R m 2 SiY 4-m wherein R 2 is alkyl or aryl, Y is alkoxy and m is 0 or 1 and (3) an effective amount of a catalyst, wherein the improvement resides in employing as said catalyst a stannous salt of a monoethylenically unsaturated monohydroxy monocarboxylic acid containing from 10 to 20 carbon atoms.
This invention also provides compositions for preparing heat-resistant elastomeric polysiloxanes. The compositions contain the three ingredients listed in the preceding paragraph.
DETAILED DESCRIPTION OF THE INVENTION
The novel feature of the present invention resides in the catalyst employed for the reaction of the difunctional polysiloxane with the crosslinking agent to form the cured elastomeric polyorganosiloxane. These catalysts are stannous salts of ethylenically unsaturated hydroxycarboxylic acids that contain from 10 to 20 carbon atoms. A preferred catalyst is the stannous salt of ricinoleic acid (12-hydroxy-9-octadecenoic acid). As previously disclosed, this class of catalysts is unique among the compounds of divalent tin, most of which are too active for use with conventional polyorganosiloxane compositions. The working life or pot life of polyorganosiloxane compositions containing stannous-2-ethylhexoate is five minutes or less. Replacing the 2-ethylhexoic acid with oleic acid increases the working life to about 30 minutes. By the addition of a hydroxyl group to oleic acid to form ricinoleic acid, the catalytic activity of the corresponding stannous salt is reduced by a factor of four, and the working life of a polysiloxane composition containing this catalyst is increased to two hours or more. It is not apparent that the addition of a hydroxyl group to an ethylenically unsaturated carboxylic acid would have such a profound effect on the catalytic activity of the corresponding stannous salt, with a resultant increase in the working life of the composition.
The present catalysts can be employed to prepare cured polyorganosiloxane elastomers at ambient temperatures using any of the conventional precondensed difunctional organosiloxanes, crosslinking agents and optional inert fillers. Suitable reagents and fillers are disclosed in U.S. Pat. No. 3,127,363, the pertinent sections of which are hereby incorporated by reference.
The present crosslinking agents are preferably organosilicates represented by the formula R n Si(OR') 4-n wherein R' usually contains from 1 to 4 carbon atoms. These crosslinking agents can be employed as the monomeric compound or as a liquid product obtained by partial hydrolysis of the monomeric compounds using water and small amounts of acid.
The amounts of alkyl silicate and curing catalyst can be varied within fairly wide limits, depending upon the desired curing time and the desired physical properties of the cured material. Generally it has been found that the alkyl silicate or an oligomeric hydrolysis product derived therefrom can be present at concentrations of from 0.1 to 10%, and the catalyst is present at concentrations of from 0.1 to about 5%, both concentration ranges being based on the weight of polyorganosiloxane. The weight ratio of organosilicate to catalyst is generally from 0.1 to 3 parts of catalyst per part of silicate.
In addition to the silicone compounds and catalyst the curable compositions of this invention generally contain one or more reinforcing fillers to modify the physical properties of the final cured product. Useful fillers include calcium carbonate, titanium dioxide, lithopone, zinc oxide, fumed silica, and glass fibers. The amount of filler used can be varied within relatively wide limits (10 to about 300%, based on the aforementioned polyorganosiloxane), depending upon the density of the filler and the application of the final cured product.
The present compositions can be prepared by blending the silicon compounds, catalyst and any other ingredients, including fillers, until a homogeneous mixture is obtained. The viscosity of such a mixture will remain relatively stable for two hours or longer at ambient temperature (20° to 30° C.) and a relative humidity below about 70%, which is the desired working life for an uncured composition. It may be desirable to store a catalyzed composition for short periods of time prior to curing.
The following example represents a preferred embodiment of this invention and should not be interpreted as limiting the scope of the claims.
The composition employed to evaluate the various catalysts contained 100 parts by weight of a hydroxyl-terminated dimethylpolysiloxane exhibiting a degree of polymerization, represented by n in the foregoing formula, of from 25 to 50, 3 parts by weight of a partially hydrolyzed ethyl silicate and 40 parts calcium carbonate. Fifty grams of this composition were combined with a specified amount of the catalyst to be evaluated and stirred rapidly to insure homogenity. The resultant mixture was allowed to remain under ambient conditions. Periodically, at about quarter hour intervals, the mixtures were tested using a spatula. Initially the compositions were sufficiently fluid to flow or drip off the spatula. As curing progressed the fluid became more elastomeric in character. As the spatula was withdrawn from the material a portion of the material adhered to the spatula but remained connected to the main mass of material. At a point during the curing cycle the connecting portion elongated to an extent and then abruptly severed or "snapped" in a manner similar to a rubber band when elongated beyond its elastic limit. The time at which this elastomeric behavior, referred to as "snap" was first observed is recorded in the accompanying table as the "snap time".
The hardness of the final cured product was measured using a Shore type A durometer. The cured material was then heated at 200° C. for 24 hours in an oven, following which the hardness was again measured. A decrease in hardness indicates that partial depolymerization of the cured product had occurred during heating. Each of the catalysts was employed at a concentration level equivalent to a tin content of 0.1%, based on the weight of the composition.
Stannous ricinoleate was prepared by reacting ricinoleic acid (90% purity) with stannous methoxide in a molar ratio of 1.8:1, respectively. Toluene was employed as the diluent and the reaction mixture was heated to the boiling point. The methanol which formed as a by-product was removed by azeotropic distillation at a temperature of 64° C. After substantially all of the methanol had been removed the reaction mixture was heated at the boiling point for 1/2 hour, following which the toluene was evaporated. The product, stannous ricinoleate, was an amber liquid that was found to contain 15.5% tin.
The other catalysts evaluated are commercially available.
______________________________________ Catalyst Concen- tration Snap Hardness (% by Time (Shore A)Catalyst Type weight) (Hours) Ambient.sup.1 100° C.______________________________________Stannous Ricinoleate 0.71 2.3 45 49Dibutyltin Dilaurate 0.55 3.0 50 35(control)Stannous-2-Ethylhexoate 0.36 0.2 50 49(control)Stannous "Oleate".sup.2 0.60 0.5 50 51(control)Dibutyltin-S,S'-bis 0.55 4.sup.3 37 20(isooctyl mercapto-acetate) (control)______________________________________ .sup.1 Exposure Time = 24 hours. .sup.2 Prepared using a commercial grade of oleic acid (a mixture consisting mainly of oleic and linoleic acids). .sup.3 Formulation cured at 100° C.
The data in the preceding table demonstrate that while the extent of cure (determined by hardness of the sample) achieved using stannous 2-ethylhexoate and stannous oleate was acceptable and no depolymerization occurred at 200° C., the working time or "pot life" of catalyzed compositions was relatively short. The working life can be extended using organotin compounds wherein tin is in the tetravalent state, however, these compounds also catalyze polymer degradation at elevated temperatures, as indicated by the decrease in hardness when the samples were heated at 200° C. for 24 hours. The present class of stannous compounds are unique in that they combine the advantages of stannous and organotin compounds yet do not exhibit the disadvantages of either class of catalysts.
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Heat-resistant, polyorganosiloxane elastomers are prepared by reacting a linear, difunctional polyorganosiloxane with a silicon-containing crosslinking agent and a stannous salt of a monoethylenically unsaturated monohydroxy monocarboxylic acid as the curing catalyst. A filler can optionally be included in the formulation. The present catalysts are unique in that they impart a relatively long working life to the uncured composition yet do not catalyze the depolymerization reaction at elevated temperatures as do conventional organotin catalysts such as dibutyltin dilaurate.
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This is a division of application Ser. No. 08/476,188, filed Jun. 7, 1995 now U.S. Pat. No. 5,885,924.
BACKGROUND OF THE INVENTION
Transition metal catalysts, i.e., Ziegler-Natta and metallocenes, generally cannot be practically used for gas or slurry phase polymerization unless sufficiently supported. The use of supported catalysts offers the possibility of gas and slurry phase compatibility. Control of the particle size distribution of the polymeric product in the various polymerization processes eliminates or reduces the extent of reactor fouling.
Supported catalysts for olefin polymerization are well known in the art. These catalysts offer, among other things, the advantages of being useable in gas or slurry phase reactors, allowing the control of polymer particle size and thereby the control of the product bulk density. Gas phase reactors also eliminate the need for a solvent and the equipment for solvent handling during separation of the solvent from the resin. However, it is known that transition metal catalysts, particularly metallocene catalysts, are deactivated by supports that contain reactive functionalities, such as silicas which are oxide supports.
Accordingly, when using supported polyolefin catalysts, it is often desired to remove or reduce hydroxyl groups and other reactive functionalities from the support particles before and/or during manufacture of the supported catalyst. Removal of the reactive functionalities is often desirable since they will often react with the catalyst thereby deactivating it.
For example, in the past, various thermal and/or chemical treatments have been used in an effort to achieve dehydroxylation of the oxide particles.
Thermal treatments (i.e., calcining) are advantageous from the point that they do not add undesirable chemicals to the support and that they are relatively simple inexpensive processes. Unfortunately, thermal treatments are often ineffective for achieving a high degree of dehydroxylation. Further, for many porous oxide supports (e.g., silica gel), thermal treatments often result in an undesirable loss of pore volume, shrinkage of the pores and/or loss of surface area.
Furthermore, a variety of chemical treatments have been attempted to remove or deactivate reactive functionalities. Many types of chemicals have been used such as organo aluminum compounds, magnesium chloride/dehydrating agent combinations, organosilanes, halosilanes, silanes, etc. These various chemical processes are often expensive and may result in the addition of undesired or complicating constituents to an oxide support.
Thus, there remains a need for improved catalytic supports and supported activators having the undesired reactive functionalities deactivated.
Moreover, it is sometimes desirable to impart different characteristics to the support surface. The attachment of selected organic moieties to the support effects the characteristics of the support and hence the catalytic nature of the catalyst and/or activator placed on the support.
Thus it is an object of this invention to provide a method to deactivate reactive functionalities on catalytic supports as well to provide for a new support for transition metal catalysts and a supported catalytic activator.
Furthermore, it is an object of the present invention to provide a supported activator and a supported transition metal catalyst and/or catalyst system (support, activator and catalytic precursor) capable of not only producing polymers, but also providing a catalyst with hydrogen sensitivity so as to allow use of hydrogen to control molecular weight in olefin polymerization reactors.
SUMMARY OF THE INVENTION
The invention provides supports, supported catalytic activators and supported catalytic systems, wherein the supports have unique surface chemical compositions. The present invention further includes methods for making and using such compositions.
In particular, the present invention uses halogenated organic moieties that are covalently bonded to the support surface. Reactive functionalities on typical catalyst supports, such as hydroxyl groups, known as catalyst poisons, are consumed and the halogenated, most preferably fluorinated, organics are bonded to the support in their stead. These halogenated organic supports are ideal for supporting transition metal catalysts, particularly metallocene and/or Ziegler-Natta catalysts, particularly when a borate and/or aluminate catalyst activator is used. The support and supported catalytic activator of the present invention imparts enhanced properties, including improved activity and reduced reactor fouling while obtaining a resin particle of good morphology, bulk density, and enhanced comononer incorporation.
In one aspect, the present invention is a support composition represented by the following formula.
Carrier—L—RX (n) :,
wherein the Carrier is not particularly limited and includes any material capable of forming a covalent bond with the halogenated organic group RX(n) and includes inorganic carriers, inorganic oxide carriers and organic carriers. Of these, inorganic carriers and inorganic oxide carriers are particularly preferred.
RX (n) X′ is any halogenated organic compound, wherein X and X′ are independently halogen groups and typically are fluorine, chlorine, iodine, and bromine and mixtures thereof; and n is a number from 1 to 9.
L represents the linkage resulting from the reaction of the support reactive functionality with a base (described below) that would be present on the support and capable of forming a covalent bond with the halogenated organic group RX n .
In another aspect of the invention, the invention provides a supported catalytic activator for use with transition metal catalytic precursor represented by the below formula.
Carrier—L—RX (n) [Compound A]
Where the Carrier, L, and RX (n) are as described above and Compound A is a compound capable of forming an ionic complex when reacted with a transition metal catalytic precursor and is further represented by the formulas [Ct] + [M n (Q 1 −Q n+1 )] − and M n Q n .
[Ct] + is an activating cation, which may be a Bronsted acid capable of donating a proton to the transition metal catalytic precursor resulting in a transition metal cation; or [Ct] + may be an abstracting moiety that is capable of reacting with a transition metal catalytic precursor resulting in the transition metal cation.
[M n (Q 1 −Q n+1 ] − is a compatible, large (bulky), non-coordinating anion capable of stabilizing the active transition metal catalytic species which is formed when the transition metal catalyst precursor is combined with the supported activator of present invention. These anionic coordination complexes comprise a plurality of lipophilic radicals covalently coordinated to and shielding a central charge-bearing metal or metalloid.
M n (Q n ) is a large (bulky), non-coordinating, neutral species that is capable of stabilizing the active transition metal catalytic species which is formed when the transition metal catalyst precursor is combined with the supported activator of present invention. These anionic coordination complexes comprise a plurality of lipophilic radicals covalently coordinated to and shielding a central charge-bearing metal or metalloid.
In a third embodiment of the present invention, the support or the supported activator is combined (in any order of addition) with a transition metal catalytic precursor to provide a supported catalyst or a supported catalytic system. The support or the supported activator of the present invention may be combined with the transition metal catalytic precursor either prior to or during introduction to the polymerization reactor zone. Upon contact with the activator, the transition metal precursor reacts to form the active catalytic species.
The invention further includes the method for producing halogenated supports, supported catalytic activators, and catalyst systems as well, and methods for using the halogenated support in transition metal catalyst systems to polymerize olefins, diolefins, cyclic olefins and acetylenically unsaturated monomers to produce polymers, particularly polyethylene.
These and other aspects of the invention will be described in further detail below.
DETAILED DESCRIPTION OF THE INVENTION
The invention broadly encompasses support particles characterized by the present of halogenated organic groups on the particle surface represented by the formula Carrier- L- RX (n) :; and further a supported catalytic activator represented by the formula Carrier- L -RX (n) :: [Compound A] and supported catalyst systems by placing transition metal catalysts on the support of the present invention or the supported catalytic activator of the present invention. For purposes of this invention the symbol . . . is intended to represent a weak coordinative bond between the RX n groups and Compound A as disclosed in Organometallics, 1995, Vol. 14, pages 3135 to 3137; and Angew Chem. Int. Ed. Engl., 1992, Vol. 31, No. 10, pages 1375 to 1377.
The components of the present invention are described below.
The Carrier
The carrier particles of the invention may be virtually any material having a reactive functionality and capable of forming a covalent bond to the halogenated organic compound RX (n) X′.
The carrier suitable for the present invention includes inorganic carriers, inorganic oxide carriers, and organic carriers. Of these, inorganic carriers and inorganic oxide carriers are particularly preferably. More specifically, the inorganic carriers include magnesium compounds or their complex salts such as MgC12, MgC1(OEt) and Mg(OEt) 2 , and organic magnesium compounds such as those represent by MgR 2 a X 2 b . As used herein, R 2 is an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms; X 2 is a halogen atom; a is a number from 0 to 2 and b is a number from 0 to 2.
Inorganic oxide carriers include talcs, clays, SiO 2 , Al 2 O 3 , MgO, ZrO 2 , TiO 2 , Fe 2 O 3 , B 2 O 3 , CaO, ZnO, BaO, ThO 2 and mixtures thereof such as silica alumina, silica alumina titania, zeolite, ferrite and glass fibers. In addition, the above-mentioned inorganic oxide carriers may contain a small amount of carbonates, nitrates, sulfides or the like.
Additional carrier materials include aluminum phosphate gel materials as well as polymeric or organic supports containing reactive functionalities such as polyvinylcholoride, polyvinylalcohol, poly(methylmethacrylate) and hydroxy substituted polystyrene and mixtures of two or more of the foregoing.
Preferred carrier materials are silica or alumina based materials such as silica, and oxides of Si—Al, Si—Ti, Si—Al—Ti, SiMgCl 2 , and aluminum phosphate gel materials and mixtures thereof; and most preferred materials are silica, silica-alumina, silica-alumina-titania and SiMgCl 2 materials and mixtures thereof.
The carriers suitable for this invention can be, but need not be calcined before use.
Preferably, the carriers are compositions conventionally used as a catalyst support material. The degree of porosity in the carrier may be any level that is achievable in the starting material. Preferably, the carrier particles of the present invention have a pore volume of at least 0.3 cc/g; preferably from 0.3 to 5 cc/g; more preferably from 0.3 to 3 cc/g; and most preferably, the pore volume exceeds 1 cc/g. Preferably, the carrier particles have a surface area of about 1-1000 m 2/ g; preferably from 200-800 m 2/ g; and most preferably from 250 to 650 m 2 /g. The typical median particle size for a suitable carrier for this invention is from 1 to 300 microns, preferably from 10 to 200 microns, more preferably from 20 to 100 microns.
Pore volume and surface area can be, for example, measured from volume of nitrogen gas adsorbed in accordance with BET method. (Refer to J. Am. Chem. Soc., vol. 60, p. 309 (1938)).
The Linker
L represents the linkage resulting from the reaction of the support reactive functionality with a base (described below) and is preferably selected from the group comprising oxygen, carbon, sulfur, nitrogen, boron and mixtures thereof, that would be present on the support and capable of forming a covalent bond to the halogenated organic compound RX (n) X′.
The Halogenated Organic
The halogenated organic groups on the support particle surface are believed to be substituted for at least some of the reactive functionality groups on the surface of the carrier particles. The net effect of the substitution is to form a linkage (L) between the support and the halogenated organic group (RX (n) ) where L and RX (n) is as herein defined. The total amount of RX (n) groups on the support surface is dependent on the number of reactive groups present on the carrier to be treated. The amount of RX (n) groups is typically about 10 mmol per gram of support (mmole/g) or less (but greater than zero), preferably, from 0.1 to 5 mmole/g; and most preferably, from 1.0 to 3.0 mmole/g.
RX (n) is any halogenated organic group where X is a halogen group element and is typically fluorine, chlorine, and bromine and mixtures thereof; preferred is fluorine; n is a number from 1 to 9; and R is mono or multi-cyclic aryls, alkyls, and alkenyl groups and mixtures thereof; preferred are C 1-20 alkenyl groups (such as ethene, propylene, butene, and pentene); C 1-20 alkyl groups (such as methyl, ethyl, n-proply, iso-propyl, n-butyl, n-octyl, and 2-ethylhexyl groups), C 6-20 aryl group (including substituted aryls) (such as phenyl, p-tolyl,benzyl, 4-t-butylphenyl, 2,6 dimethylphenyl, 3,5-methylphenyl, 2,4-dimethylphenyl, 2,3-dimethylphenyl groups) and mixtures thereof. More preferred R groups are C 1-5 alkyls, C 2-5 alkenyls, phenyl and napthyl and mixtures thereof.
Preferred RX (n) groups are C 1-20 halogenated hydrocarbon groups such as XCH 2 , X 2 CH, X 3 C, C 2 X n H n-5 (where n=1-5), C 3 H n X n-7 (n=1-7) and C 6 X n X n-6 (n=1-6) and mixtures thereof; most preferably, FCH 2 , CHF 2 , F 3 C, and fluorosubstituted phenyl, wherein the phenyl can be mono to pentasubstituted (such as p-fluorophenyl, 3-5-diflourophenyl, pentafluorophenyl, 3,4,5-trifluorophenyl, and 3,5-bis(trifluoromehyl) phenyl groups) and mixtures thereof; of these the most preferred is pentafluorophenyl.
Compound A
Compound A is a compound capable of forming an ionic complex when reacted with a transition metal catalytic precursor and is further represented by the formulae:
[Ct] + [M n (Q 1 −Q n+1 )] −
and
M n (Q n ).
[Ct] + is an activating cation, which may be a Bronsted acid capable of donating a proton to the transition metal ionic catalytic precursor resulting in a transition metal cation. Such Bronsted acids include but are not limited to ammoniums, oxoniums, phosphoniums and mixtures thereof; preferably ammoniums of methylamine, aniline, dimethylamine, diethylamine, N-methylaniline, diphenylamine, trimethylamine, triethylamine, N-N-dimethylaniline, methyldiphenylamine, pyridine, p-bromo-N,N,-dimethylaniline, p-nitro-N,N-dimethylaniline; phosphoniums from triethylphosphine, triphenylphosphine and diphenylphosphine; oxoniums from ethers such as diethyl ether, tetrahydrofuran and dioxane; sulfoniums from thioethers such as diethyl thioethers and tetrahydrothiophene; mixtures thereof; most preferably dimethylanilinium.
Furthermore, [Ct] + may be an abstracting moiety that is capable of reacting with a transition metal catalytic precursor resulting in the transition metal cation. Acceptable abstracting moiety include but are not limited to silver, carbocations, tropylium, carbeniums, ferroceniums and mixtures thereof, preferably caboniums and ferroceniums and mixtures thereof; and most preferably triphenyl carbenium. The [Ct] + may also including mixtures of the Bronsted acids and the abstracting moiety species.
[M] is selected from the group consisting of boron, phosphorus, antimony or aluminum and mixtures thereof, having the n valence state. Preferably, the [M] is born, aluminum and mixtures thereof.
[Q 1 −Q n+1 ] are independent, wherein Q 1 −Q n+1 are RX (n) as is defined above and wherein each of the Q in the coordinating anion may be the same or different and may be the same or different from the RX (n) bonded to the support through the linker L defined above. Moreover, in this RX, the Q 1 to Q n may be hydride radicals, bridged or unbridged dialkylamido radicals, alkoxide and aryloxide radicals, substituted hydrocarbyl radicals, halocarbyl- and substituted-halocarbyl radicals and hydrocarbyl-substituted organometalloid radicals. Additionally, the Q 1 to Q n can simply be the X alone; for example as in BX 4 − .
In addition, neutral M n (Q n ), can be used in place of the [Ct] + [Mn(Q 1 Q n+1 )] − , for example B(C 6 F 5 ) 3 .
Preferred [M n (Q 1 −Q n+1 )] − are selected from the group consisting of Bphenyl 4 − , B(C 6 H 2 (CF 3 ) 3 ) 4 − , B(C 6 H 5 ) 4 − , AlPhenyl 4 − , Al(C 6 H 2 (CF 3 ) 3 ) 4 − , Al(C 6 H 5 ) 4 − , PF 6 − , BF 4 − , B(OPh) 4 − and mixtures thereof; preferably, B(C 6 F 5 ) 4 − , Al(C 6 F 5 ) 4 − , Al(C 6 H 2 (CF 3 ) 3 ) 4 − , Al(C 6 H 5 ) 4 − , BC 6 H 2 (CF 3 ) 3 ) 4 − and mixtures thereof; most preferred are B(C 6 F 5 ) 4 − , Al(C 6 F 5 ) 4 − and mixtures thereof. Preferred M n (Q n ) from the neutral species of the preferred list above of [M n (Q 1 −Q n+1 )] − .
Transition Metal Catalytic Precursors
The transition metal catalytic precursors are typically Ziegler-Natta catalysts including metallocenes. The term metallocenes is defined as organometallic compounds having a transition metal, including rare earth metals, in coordination with members of at least one five-member carbon ring, heterosubstituted five-member carbon ring, or a bridged (ansa) ligand defined as multi cyclic moieties capable of coordinating to the transition or rare earth metals.
The ansa bridge can be selected from the group comprising carbon, silicon, phosphorus, sulfur, oxygen, nitrogen, germanium, species such as, R 3 2 C, R 3 2 Si, R 3 2 Ge, R 3 2 CR 3 2 C, R 3 2 SiR 3 2 Si, R 3 2 GeR 3 2 Ge, R 3 2 CR 3 2 Si, R 3 2 CR 3 2 Ge, R 3 2 CR 3 2 CR 3 2 C, R 3 2 SiR 3 2 Si diradicals where R 3 is independently selected from the group containing hydride, halogen radicals, and C1-20 hydrocarbyl radicals and B1 the like. Preferably, the ansa bridge has a length of two atoms or less as in methylene, ethylene, diphenysilyl, dimethylsilyl, propylidene and methylphenylsilyl.
The transition metal component of the metallocene is selected from Groups 3 through 10, lanthanides and actinides of the Periodic Table and mixtures thereof; and most preferably, titanium, zirconium, hafnium, chromium, vanadium, samarium and neodymium and mixtures thereof. Of these Ti, Zr, and Hf and mixtures thereof are most preferable.
In one preferred embodiment, the metallocene catalyst precursor is represented by the general formula (CP) M MR 4 n R 5 p , wherein Cp is a substituted or unsubstituted cyclopentadienyl ring, M is a Group 3-6, lanthanide, actinide series metal from the Periodic Table and mixtures thereof; R 4 and R 5 are independently selected halogen, hydrocarbyl group, or hydrocarboxyl groups having 1-20 carbon atoms; m=1-3, p=0-3 and the sum of m+n+p equals the oxidation state of M.
In another embodiment the metallocene catalyst is represented by the formulae:
(C 5 R 6 m ) p R 7 s (C 5 R 6 m )MZ 3−p−x
and
R 7 s (C 5 R 6 m ) 2 MZ′.
Wherein M is a Group 3-6, lanthanide, actinide series metal from the Periodic Table and mixtures thereof; C 5 R 6 m is a substituted cyclopentadienyl each R 6 , which can be the same or different is hydrogen, alkenyl, aryl, or arylalkyl radical having from 1 to 20 carbon atoms or two carbon atoms joined together to form a part of a C 4 to C 6 ring; R 7 is one or more of or a combination of a carbon, a germanium, a silicon, a phosphorous or a nitrogen atom containing radical substitution on and bridging two C 5 R 6 m rings or bridging one C 5 R 6 m ring back to M, when p=0 and x=1 otherwise x is always equal to 0, each Z which can be the same or different is an aryl alkyl, alkenyl, alkaryl, or arylalkyl radical having from 1-20 carbon atoms or halogen, Z′ is an alkylidene radical having from 1 to 20 carbon atoms, s is 0 to 1 and when s is 0, m is 5 and p is 0, 1, or 2 and when s is 1, m is 4 and p is 1.
In particular, preferred metallocenes are derivatives of a cyclopentadiene (Cp), including cyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl, and 1,1-disubstituted silacyclopentadienes, phosphocyclopentadienes, 1-metallocyclopenta-2,4-dienes, bis(indenyl)ethane and mixtures thereof.
Additional illustrative but non-limiting examples of metallocenes represented by the above definition are dialkyl metallocenes such as bis(cyclopentadienyl)titanium dimethyl, bis(cyclopentadienyl)titanium diphenyl, bis(cyclopentadienyl)zirconium dimethyl, bis(cyclopentadienyl)zirconium diphenyl, bis(cyclopentadienyl)hafnium dimethy 1 and diphenyl, bis(cyclopentadienyl)titanium di-neopentyl, bis(cyclopentadienyl)zirconium di neopentyl, bis(cyclopentadienyl)titanium dibenzyl, bis(cyclopentadienyl)zirconium dibenzyl, bis(cyclopentadienyl)vanadium dimethyl; the mono alkyl metallocenes such as bis(cyclopentadienyl)titanium methyl chloride, bis(cyclopentadienyl)titanium ethyl chloride, bis(cyclopentadienyl)titanium phenyl chloride, bis(cyclopentadienyl)zirconium methyl chloride, bis(cyclopentadienyl)zirconium ethyl chloride, bis(cyclopentadienyl)zirconium phenyl chloride, bis(cyclopentadienyl)titanium methyl bromide; the trialkyl metallocenes such as cyclopentadienyl titanium trimethyl, cyclopentadienyl zirconium triphenyl, and cyclopentadienyl zirconium trineopentyl, cyclopentadienyl zirconium trimethyl, cyclopentadienyl hafnium triphenyl, cyclopentadienyl hafnium trineopentyl, and cyclopentadienyl hafnium trimethyl; monocyclopentadienyls titanocenes such as, pentamethylcyclopentadienyl titanium trichloride, pentaethylcyclopentadienyl titanium trichloride; bis(pentamethylcyclopentadienyl) titanium diphenyl, the carbene represented by the formula bis(cyclopentadienyl)titanium=CH2 and derivatives of this reagent; substituted bis(cyclopentadienyl)titanium (IV) compounds such as: bis(indenyl)titanium diphenyl or dichloride, bis(methylcyclopentadienyl)titanium diphenyl or dihalides; dialkyl, trialkyl, tetra-alkyl and penta-alkyl cyclopentadienyl titanium compounds such as bis(1,2-dimethylcyclopentadienyl)titanium diphenyl or dichloride, bis(1,2-diethylcyclopentadienyl)titanium diphenyl or dichloride; silicon, phosphine, amine or carbon bridged cyclopentadiene complexes, such as dimethyl silyldicyclopen tadienyl titanium diphenyl or dichloride, methyl phosphine dicyclopentadienyl titanium diphenyl or dichloride, methylenedicyclopentadienyl titanium diphenyl or dichloride and other dihalide complexes, and the like; as well as bridged metallocene compounds such as isopropyl(cyclopentadienyl)(fluorenyl)zirconium dichloride, isopropyl(cyclopentadienyl)(octahydrofluorenyl)zirconium dichloride diphenylmethylene(cyclopentadienyl)(fluorenyl) zirconium dichloride, diisopropylmethylene(cyclopentadienyl)(fluorenyl)zirconium dichloride, diisobutylmethylene(cyclopentadienyl)(fluorenyl)zirconium dichloride, ditertbutylmethylene(cyclopentadienyl)(fluorenyl)zirconium dichloride, cyclohexylidene(cyclopentadienyl)(fluorenyl)zirconium dichloride, diisopropylmethylene (2,5-dimethylcyclopentadienyl)(fluorenyl)zirconium dichloride, isopropyl(cyclopentadienyl)(fluorenyl)hafnium dichloride, diphenylmethylene(cyclopentadienyl)(fluorenyl)hafnium dichloride, diisopropylmethylene(cyclopentadienyl)(fluorenyl)hafnium dichloride, diisobutylmethylene(cyclopentadienyl)(fluorenyl)hafnium dichloride, ditertbutylmethylene(cyclopentadienyl)(fluorenyl)hafnium dichloride, cyclohexylidene(cyclopentadienyl)(fluorenyl)hafnium dichloride, diisopropylmethylene(2,5-dimethylcyclopentadienyl)(fluorenyl)hafnium dichloride, isopropyl(cyclopentadienyl)(fluorenyl)titanium dichloride, diphenylmethylene(cyclopentadienyl)(fluorenyl)titanium dichloride, diisopropylmethylene(cyclopentadienyl)(fluorenyl)titanium dichloride, diisobutylmethylene(cyclopentadienyl)(fluorenyl)titanium dichloride, ditertbutylmethylene(cyclopentadienyl)(fluorenyl)titanium dichloride, cyclohexylidene(cyclopentadienyl)(fluorenyl)titanium dichloride, diisopropylmethylene(2,5 fluorenyl)titanium dichloride, racemic-ethylene bis(1-indenyl)zirconium(IV)dichloride, racemic-ethylene bis(4,5,6,7-tetrahydro-1-indenyl)zirconium(IV)dichloride, racemic-dimethylsilyl bis(1-indenyl) zirconium(IV)dichloride, racemic-dimethylsilyl bis(4,5,6,7-tetrahydro-1-indenyl)zirconium(IV)dichloride, racemic-1,1,2,2- tetramethylsilanylene bis(1-indenyl) zirconium(IV)dichloride, racemic-1,1,2,2-tetramethylsilanylene bis(4,5,6,7-tetrahydro-1-indenyl)zirconium(IV), dichloride, ethylidene (1-indenyl tetramethylcyclopentadienyl)zirconium(IV)dichloride, racemic-dimethylsilyl bis(2-methyl-4-t-butyl-1-cyclopentadienyl)zirconium(IV)dichloride, racemic-ethylene bis(1-indenyl)hafnium(IV)dichloride, racemic-ethylene bis(4,5,6,7-tetrahydro-1-indenyl)hafnium(IV)dichloride, racemic-dimethylsilyl bis(1-indenyl)hafnium(IV)dichloride, racemic-dimethylsilyl(4,5,6,7-tetrahydro-1- indenyl)hafnium(IV)dichloride, racemic-1,1,2,2-tetramethylsilanylene bis(1-indenyl)hafnium(IV)dichloride, racemic-1,1,2,2-tetramethylsilanylene bis(4,5,6,7-tetrahydro-1-indenyl)hafnium(IV), dichloride, ethylidene(1-indenyl-2,3,4,5-tetramethyl-1-cyclopentadienyl)hafnium(IV)dichloride, racemic-ethylene bis(1-indenyl)titanium(IV)dichloride, racemic-ethylene bis(4,5,6,7-tetrahydro-1-indenyl)titanium(IV)dichloride, racemic-dimethylsilyl bis(1-indenyl)titanium(IV)dichloride, racemic-dimethylsilyl bis(4,5,6,7-tetrahydro-1-indenyl)titanium(IV)dichloride, racemic-1,1,2,2-tetramethylsilanylene bis(1-indenyl)titanium(IV)dichloride racemic-1,1,2,2-tetramethylsilanylene bis(4,5,6,7-tetrahydro-1-indenyl)titanium(IV)dichloride, and ethylidene(1-indenyl-2,3,4,5-tetramethyl-1-cyclopentadienyl)titanium IV) dichloride.
Preferred metallocenes are bis(cyclopentadienyl)titanium dimethyl, bis(cyclopentadienyl)zirconium, isopropyl(cyclopentaienyl)fluroenyl)zirconium dimethyl, bis(1-indenyl)zirconium(IV)dimethyl, (4,5,6,7-tetrahydro-1-indenyl)hafnium(IV)dimethyl, dimethylzirconene, dimethyethylenebisindenylzirconium, and dimethylethylene bis(tetrahydroindenyl)zirconium.
The transition metal catalyst useful in this invention can also include non-cyclopentadienyl catalyst components (such as pentadienyls) as well as ligands such as borollides or carbollides in combination with a transition metal.
Transition metal catalyst precursor also includes traditional Ziegler-Natta (“ZN”) catalysts precursor which are represented by the formula M′ a R a wherein M′ is a transitional metal from the Groups 3 through 10, the lanthanide, actinide Series in the Periodic Table, wherein “a” is its valence state and the number of R′s is equal to “a” and each may be the same or different and independently selected from the group consisting of halogens(preferably Cl and Br); alkyls(preferably C 1 -C 20 ; more preferably ethyl, butyl, octyl and ethylhexyl); alkoxys (preferably C 1 -C 20 , more preferably ethoxy, isopropoxy, butoxy and phenoxy); aryls (preferably C 6 -C 20 , including substituted aryls, more preferably phenyl, p-tolyl, benzyl, 4-t-butylphenyl, 2,6-dimethylphenyl, 3,5-methylphenyl, 2,4-dimethylphenyl, 2,3-dimethylphenyl groups) and mixtures thereof. For example, TiCl 4 , TiCl 3 , VOCl 3 , VCl 4 , TiPhenyl 4 , V(OButyl) 3 , tetramethyl zirconium, tetrabenzylzirconium, tetramethoxyzirconium, tetraethoxyzirconium, tetrabutoxyzirconium, bis(2,5-di-t-butylphenoxy)dimethylzirconium, bis(2,5-di-t-butylphenoxy)dichlorozirconium and zirconium bis(acetylacetonate), tetramethyl titanium, tetrabenzyltitanium, tetramethoxytitanium, tetraethoxytitanium, tetrabutoxytitanium, bis(2,5-di-t-butylphenoxy)dimethyltitanium, bis(2,5-di-t-butylphenoxy)dichlorotitanium and titanium bis(acetylacetonate) and mixtures thereof.
Methods of Producing the Compositions of the Present Invention
Making the Support
The methods of the invention generally encompass a step where reactive functionality containing carrier particles are reacted with a halogenated organic in the presence of a base whereby at least a portion of the reactive functionality groups are removed or eliminated and the halogenated organic groups are covalently bonded to the carrier particle surface.
The base reactant used is typically a metal hydroxide (such as NaOH or KOH), primary, secondary or tertiary amines (such as methylamine, dimethylamine, triethylamine, dimethylaniline and tributylamine), metal alkyls (wherein the metal is from Group 1, 2, 13, and 14 of the Periodic Table and the alkyl are C 1 -C 8 , including n-Butyllithium, dibutyl magnesium, trimethylaluminum, methyllithium). Preferred bases are NaOH, n-butyllithium, dibutyl magnesium, triethyl amine and tributyl amine. Most preferred bases are NaOH, n-butyllithium, and tributylamine and mixtures thereof.
When an aqueous basic solution is used, the resultant reaction product should have excess water removed.
The methods preferably involve formation of an initial mixture containing the carrier particles, a base and the halogenated organic. The initial mixture preferably also contains a solvent (preferably non-aqueous); however, neat mixtures of the carrier particles, halogen and base may be used. The ingredients forming. the initial mixture may be combined in virtually any desired sequence to effect the desired transformation.
While the carrier particles may contain some free water, it is preferred that any free water be removed before the initial mixture is formed. For example, by solvent exchange, heating, and chemical reaction.
The carrier particles are preferably porous. The porosity of the particles is preferably dictated by the intended end use of the particles. Preferably, the porosity of the particles to be deactivated is such that the resulting particles would be suitable for use as polyolefin catalyst supports.
The initial mixture preferably contains a solvent to facilitate intimate mixing of the carrier particles and the reagents.
The solvent is preferably a non-aqueous solvent. Organic solvents such as C 5 -C 10 hydrocarbons, typically, hexane, tetrahydrofuran, toluene, ether and heptane are generally preferred. The amount of solvent used is not critical, but amounts in excess of that needed to form a pourable slurry are generally unnecessary.
The mixing temperature depends on the solvent and base used and can vary from well below 0° C. to the reflux temperature of the solvent, preferably from about 0° C. to the reflux temperature of the solvent.
In general the method of the present invention comprises the steps of combining the carrier and the base and mixing a temperature in the range of from about −78° C. to the reflux temperature of the solvent (preferably from about 0° C. to the ref lux temperature of the solvent). The mixing time depends on the mixing temperature. In general the higher the temperature the shorter the time required. Mixing should continue until the reaction between the carrier's functionality groups and the basic reagent is completed.
While reacting the support with the halogenated organic can generally be completed in a single reaction step, it is possible to repeat the reaction step by recovering the support particles and forming a new reaction mixture in the same manner as for the formation of the initial mixture.
Once the desired level of functionality has been accomplished, the support particles may be recovered from the mixture. The preferred level of the functionality is a approximately 10 mmoles per gram of support; more preferably, 0.1-5 mmole/g; and more preferably, 1-3 mmole/g. This can be determined by known analytical techniques, such as IR, NMR, and elemental analysis.
Preferably, recovery can be accomplished by simply evaporating the solvent and other reactants. In some instances, it may be desirable to wash the halogenated carrier with a solvent to further remove any residual reactants(such as the base), etc. Preferably, however, the reactants are selected such that they are all removable by volatilization. Preferably, the removal is conducted under at least a partial vacuum. If desired, techniques such as spray drying may be employed.
The carrier of the present invention will typically be in the form of a free flowing powder having the surface groups R as defined above used in the reacting step. The recovered product may be further treated as desired to place a catalyst or other constituents on its surface.
This support may be used to support a transition metal catalytic precursor or can be used in another embodiment of the present invention to prepare the supported activator.
Making the Supported Activator
The activator [Ct] + [M n (Q 1 −Q n+1 )] − and/or M n (Q n )as defined above, is dissolved in the desired solvent described above, preferably toluene, C 5 -C 10 hydrocarbons, and combined with the halogenated support to form a slurry. The reagents are mixed thoroughly using well known mixing and agitation techniques and can be mixed at any appropriate temperature depending on the reagents selected, preferably room temperature. This step can be performed after the halogenated support is prepared or can be accomplished simultaneously with the preparation of the halogenated support by combining all the ingredients in one step.
These materials can be combined at any temperature suitable for the reagents, typically from about −78° C. to the reflux temperature of the halogenated reagent, preferably from about 0° C. to the ref lux temperature of the solvent. This can be accomplished using multiple mixing steps. For example, the mixing can take place for one period of time at one temperature, e.g., −78° C. for two hours and then for another period of time at another temperature, e.g., reflux temperature for two hours. This stepwise (varying time and temperature) can be used for any number of mixing conditions. The time for mixing is dependent on the mixing temperature. In general, it is best to keep the temperature low so as to avoid decomposing temperature sensitive reagents. The protocol is selected so as to maximize the efficiency of the reaction.
Once the desired level of activator on the support is achieved the supported activator can be recovered by any of number of usual methods, typically by evaporating the solvent and other reactants.
Making the Supported Catalytic Systems
Transition metal (Ziegler Natta and/or metallocene) catalyst precursors can be placed on the support and/or supported activator of the present invention through various techniques. For example, once the halogenated support and/or supported activator is prepared, the catalytic precursor can be placed on the support through known techniques such as in a slurry, dry mixing or fluidized gas mixing well known to those skilled in the art. Moreover, an admixture of all necessary reagents can be prepared where the halogenated support, support activator and catalyst system are prepared simultaneously.
Furthermore, the supported activator and catalyst precursor need not be combined until introduced into the polymer reactor zone either before or during the introduction of the monomer feedstock.
Methods of Using the Compositions of the Present Invention
Activation of the supported catalyst or catalytic system of the present invention may be accomplished by any suitable method for bringing the support and/or the supported activator into contact with the transition metal catalytic precursor to create the active catalytic species. Such mixing techniques include the mixing of the dry powders, mixing through gaseous impregnation or via a slurry composition in a solvent.
It is also possible to use any of the traditional transition metal catalytic activator co-catalysts which should be selected based on the catalytic system design and desired polymer characteristics.
The activated catalyst is useful to polymerize olefinic materials, particularly ethylene. Polymerizations of olefinic monomers can be accomplished by any number of well known techniques by having the olefinic material come into contact with the polymerization catalyst(s) in a reaction zone under appropriate conditions.
As used herein, “Polymerization” includes copolymerization and terpolymeriztion and the terms olefins and olefinic monomer includes olefins, alpha-olefins, diolefins, strained cyclic, styrenic monomers, acetylenically unsaturated monomers, cyclic olefins alone or in combination with other unsaturated monomers. While the catalyst system of the present invention is active for this broad range of olefinic monomer feedstock, alpha-olefins polymerizations is preferred, especially the homopolymerization of ethylene or the copolymerization of ethylene with olefins having 3 to 10 carbon atoms.
“Polymerization techniques” for olefin polymerization according the present invention can be solution polymerization, slurry polymerization or gas phase polymerization techniques. Method and apparatus for effecting such polymerization reactions are well known and described in, for example, Encyclopedia of Polymer Science and Engineering published by John Wiley and Sons, 1987, Volume 7, pages 480-488 and 1988, Volume 12, pages 504-541. The catalyst according to the present invention can be used in similar amounts and under similar conditions to known olefin polymerization catalyst.
Typically, for the slurry process, the temperature is from approximately 0 degrees C. to just below the temperature at which the polymer becomes swollen in the polymerization medium. For the gas phase process, the temperature is from approximately 0 degrees C. to just below the melting point of the polymer. For the solution process, the temperature is typically the temperature from which the polymer is soluble in the reaction medium up to approximately 320 degrees C.
The pressure used can be selected from a relatively wide range of suitable pressures, e.g., from subatmospheric to about 350 Mpa. Suitably, the pressure is from atmospheric to about 6.9 Mpa, or 0.05-10 MPa, especially 0.14-5.5 Mpa. Pressure is dictated by the process and the desired product. In the slurry or particle form process, the process is suitably performed with a liquid inert diluent such as a saturated aliphatic hydrocarbon. Suitably the hydrocarbon is a C 4 to C 10 hydrocarbon, e.g., isobutane or an aromatic hydrocarbon liquid such as benzene, toluene or xylene. The polymer is recovered directly from the gas phase process or by filtration or evaporation from the slurry process or evaporation from the solution process.
The catalysts of the present invention are particularly suited for the gas phase or slurry process.
In addition to the examples of the present invention provided in the Examples 1-17, preferred supports, supported activators, and supported catalyst systems can be prepared from the following materials.
Table of Preferred Materials
Abbreviations:
TS =
Tosyl (paratoluene sulfonic acid)
APS =
aminopropyl silica
[DMAH] [BF 20 ] =
dimethylanilinium
tetrakis (pentafluorophenyl) borate
BEM =
butylethylmagnesium;
PVC =
Poly(vinylchloride);
PVA =
Poly(vinylalcohol)
BF 15 =
tris (pentafluorophenyl) borane;
TEAL =
triethylaluminum;
TNOA =
Tri-n-octylaluminum;
en(ind) 2 =
bisindenylethane;
APG =
Aluminumphosphate gel;
CPS =
chloropropyl silica;
PMMA =
Poly(methylmethacrylate);
CMPS =
chloromethylated poly(styrene)
BuCp =
butylcyclopentadienyl
iPr =
isopropyl
Carrier
Base/RX
Compound A
Metal Cmpd.
Silica-200° C.
KOH/BrC 3 F 7
[DMAH] [BF 20 ]
en(ind) 2 ZrMe 2
Silica-400° C.
MeOLi/TsOC 6 F 5
[DMAH] [AlF 20 ]
en(ind) 2 HfMe 2
Silica-600° C.
Bu 2 Mg/ClC 6 F 5
TNOA
(BuCp) 2 ZrCl 2
Silica-
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
iPrCpFluZrMe 2
Alumina
600° C.
PVC
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
iPrCpFluZrMe 2
PVC
Bu 2 Mg/ClC 6 F 5
TEAL
(BuCp) 2 ZrCl 2
PVA
KOH/(CF 3 ) 2 C 6 H 3
BF 15
Ph 2 C(CpTMS) 2 ZrMe 2
Silica-
BEM/ClC 3 F 7
[DMAH] [BF 20 ]
(BuCp) 2 ZrCl 2
Titania
600° C.
Silica-600° C.
MeLi/Br 2 C 6 F 4
1) t-BuLi
en(ind) 2 ZrMe 2
2) BF 15
Silica-600° C.
LiAlH 4 /BrC 6 F 5
[Ph 3 C] [BF 20 ]
Me 2 Si(C 5 Me 4 )N-t-
BuZrMe 2
PVC
MeLi/Br 2 C 6 F 4
B((CF 3 ) 2 C 6 H 3 ) 3
(BuCp) 2 ZrCl 2
Silica-800° C.
nBuLi/BrC 6 F 5
[DMAH] [BF 20 ]
en(ind) 2 ZrMe 2
Alumina
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
en(ind) 2 HfMe 2
Titania
MeMgCl/BrC 6 F 5
[DMAH] [BF 20 ]
(BuCp) 2 ZrCl 2
APG
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
iPrCpFluZrMe 2
Silica-
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
iPrCpFluZrMe 2
Titania-
Chromia
APG
MeNa/BrC 6 F 5
[DMAH] [BF 20 ]
(BuCp) 2 ZrCl 2
Silica-
MeK/BrC 6 F 5
[DMAH] [BF 20 ]
Ph 2 C(CpTMS) 2 ZrMe 2
Alumina
PVA
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
(BuCp) 2 ZrCl 2
PVC
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
en(ind) 2 ZrMe 2
CMPS
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
Me 2 Si(C 5 Me 4 )N-t-
BuZrMe 2
Brominated
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
(BuCp) 2 ZrCl 2
PE
Alumina
MeLi/Br 2 C 6 F 4
1) t-BuLi
(BuCp) 2 ZrCl 2
2) B((CF 3 ) 2 C 6 H 3 ) 3
Silica-800° C.
Cp 2 Mg/BrC 6 F 5
[DMAH] [BF 20 ]
Zr(CH 2 Ph) 4
Silica-800° C.
Bu 2 Mg/ClC 6 F 5
TEAL
TiCl 4 /(BuCp) 2 ZrCl 2
Silica-
Bu 2 Mg/ClC 6 F 5
TNOA
TiCl 4 /(BuCp) 2 ZrCl 2
Titania
Silica-600° C.
n-BuLi/BrC 6 F 5
[DMAH] [BF 20 ]
Ti(CH 2 Ph) 4 /Cp 2 ZrCl 2
APG
MeOLi/TsOC 6 F 5
[DMAH] [AlF 20 ]
Me 2 Si(C 5 Me 4 )N-t-
BuZrMe 2
Silica-
Bu 2 Mg/ClC 6 F 5
TNOA
(BuCp) 2 ZrCl 2
Alumina
PVA
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
(BuCp) 2 ZrCl 2
PVC
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
(BuCp) 2 ZrCl 2
CMPS
Bu 2 Mg/ClC 6 F 5
TEAL
Zr(CH 2 Ph) 4
Brominated
KOH/(CF 3 ) 2 C 6 H 3
BF 15
TiCl 4 /(BuCp) 2 ZrCl 2
PE
Alumina
BEM/ClC 3 F 7
[DMAH] [BF 20 ]
TiCl 4 /(BuCp) 2 ZrCl 2
Talc
n-BuLi/BrC 6 F 5
[DMAH] [BF 20 ]
Ti(CH 2 Ph) 4 /Cp 2 ZrCl 2
Montmorollin
MeOLi/TsOC 6 F 5
[DMAH] [AlF 20 ]
Me 2 Si(C 5 Me 4 )N-t-
ite, Clay
BuZrMe 2
PMMA
Bu 2 Mg/ClC 6 F 5
TNOA
(BuCp) 2 ZrCl 2
Talc
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
(BuCp) 2 ZrCl 2
Starch
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
(BuCp) 2 ZrCl 2
Zeolite
MeLi/BrC 6 F 5
[DMAH] [AlF 20 ]
Ti(CH 2 Ph) 4 /Cp 2 ZrCl 2
CPS
Bu 2 Mg/ClC 6 F 5
TEAL
en(ind) 2 ZrMe 2
APS
MeLi/BrC 6 F 5
[DMAH] [AlF 20 ]
en(ind) 2 HfMe 2
Chlorinated
Bu 2 Mg/ClC 6 F 5
TNOA
iPrCpFluZrMe 2
Silica
Fluorinated
MeOLi/TsOC 6 F 5
[DMAH] [AlF 20 ]
Me 2 Si(C 5 Me 4 )N-t-
Silica
BuZrMe 2
Silica-
Bu 2 Mg/ClC 6 F 5
TNOA
(BuCp) 2 ZrCl 2
Magnesia
Silica-
MeLi/BrC 6 F 5
[DMAH] [BF 20 ]
(BuCp) 2 ZrCl 2
Magnesia
Silica-600° C.
Bu 2 Mg/ClC 6 F 5
TNOA
TiCl 4
Silica-600° C.
KOH/
Al 2 Et 3 Cl 3
VOCl 3
Cl 3 CCO 2 C 2 Cl 7
Silica-600° C.
Bu 2 Mg/ClC 6 F 5
TNOA
VOCl 3 /TiCl 4
Silica-600° C.
MeLi/BrC 6 F 5
BF 15 /TEAL
VOCl 3 /Zr(CH 2 Ph) 4
The invention is further illustrated by the following examples. It is understood that the invention is not limited to the specific details of the examples.
EXAMPLES 1-14
Examples 1-10 are example of modifying a carrier containing reactive functionalities to create the support of the present invention. Examples 11 and 12 are examples of preparing the supported activator according to the present invention. Examples 14 are examples of the supported activator catalyst system according to the present invention.
Abbreviations:
Si—Al=Silica Alumina
Si—MgCl 2 =Silica Supported Magnesium Chloride
Si—Al—Ti=Silica Alumina Titania Cogel
CMPS=Chloromethylated Poly(styrene)
H-PS=Poly(4-hydroxystyrene)
PVA=Poly(vinylalcohol)
BPFB=Bromopentafluorobenzene
4-BTFT=4-Bromotetrafluorotoluene
B-3,5-DTFMB=Bromo-3,5-di(trifluoromethyl)benzene
1,4-DBTFB=1,4-Dibromotetrafluorobenzene
TFMI=Trifluoromethyliodide
EXAMPLES 1-14
SOL-
HALO.
EX.
CARRIER
BASE
VENT
ORG.
COMMENTS
1
Silica
NaOH
H 2 O
BPFB
100 g of silica is slurried with 0.3 moles of NaOH in 1L
of water for 4 hours. The support is filtered, washed
and dried.
20 g of the support is slurried in 150 mL of hexanes and
cooled to −78° C. under an atmosphere of argon. 80 mmols
of BPFB is added as a hexane solution. The slurry is
mixed for 1 hour at −78° C. and warmed to room temperature
(mixed 4h). The support is filtered and dried in vacuo.
2
Alumina
Bu 3 N
Hexa
4-
100 g of alumina is slurried with 0.4 moles of Bu 3 N in 1L
nes
BTFT
of hexanes for 4 hours. The support is filtered, washed
and dried under an atmosphere of argon. 20 g of the
support is slurried in 150 mL of hexanes and cooled to-
78° C. under an atmosphere of argon. 80 mmols of 4-BTFT
is added as a hexane solution. The slurry is mixed for
1 hour at −78° C. and warmed to room temperature (mixed
4h). The support is filtered and dried in vacuo.
3
CMPS
n-
Hexa
BPFB
20 g of CMPS is slurried with enough n-BuLi in 100 mL of
BuLi
nes
hexanes at 0° C. and warmed to RT for 4 hours to react
with all pendant chlorines. The reacted support is
cooled to −78° C. under an atmosphere of argon. BPFB is
added as a hexane solution to react with the produced
anionic sites. The slurry is mixed for 1 hour at −78° C.
and warmed to room temperature (mixed 4h). The support
is filtered and dried in vacuo.
4
Silica
n-
Hexa
B-3,5-DTFMB
100 g of silica is slurried with 0.3 moles of n-
BuLi
nes
BuLi in 1L of hexanes at 0° C. for 1 hour and RT
for 2 hours. The support is filtered, washed and
dried. 20 g of the support is slurried in 150 mL
of hexanes and cooled to −78° C. under an
atmosphere of argon. 80 mmols of B-3,5-DTFMB is
added as a hexane solution. The slurry is mixed
for 1 hour at −78° C. and warmed to room
temperature (mixed 4h). The support is filtered,
washed, and dried in vacuo.
5
Silica
KOH
H 2 O
1,4-DBTFB
100 g of silica is slurried with 0.3 moles of KOH
in 1L of water for 4 hours. The support is
filtered, washed and dried.
20 g of the support is slurried in 150 mL of
hexanes and cooled to −78° C. under an atmosphere
of argon. 80 mmols of 1,4-DBTFB is added as a
hexane solution. The slurry is mixed for 1 hour
at −78° C. and warmed to room temperature (mixed
4h). The support is filtered, washed and dried
in vacuo.
6
Si—Al
MeLi
Ether
BPFB
100 g of silica-alumina is slurried with 0.3 moles
of MeLi in 1L of diethyl ether at 0° C. for 2 hours
and at RT for 4 hours. The support is filtered,
washed and dried. 20 g of the support is slurried
in 150 mL of hexanes and cooled to −78° C. under an
atmosphere of argon. 80 mmols of BPFB is added
as a hexane solution. The slurry is mixed for 1
hour at −78° C. and warmed to room temperature
(mixed 4h). The support is washed, filtered and
dried in vacuo.
7
Si—MgCl 2
Bu 2 Mg
Heptanes
BPFB
100 g of silica supported magnesium chloride is
slurried in 1L of heptanes and cooled to 0° C..
200 mmol of DBM is added as a heptane solution
and mixed for 1 hour. The slurry is warmed to
RT for 4 hours. The support is filtered, washed
and dried in vacuo. 20 g of this support is
slurried 200 mL of hexanes under an argon
atmosphere and cooled to −78° C. 80 mmol of BPFB
is added as a hexane solution and the reaction
media is mixed for 1 hour. After warming to RT
the slurry is stirred an additional 4 hours
prior to filtering, washing and drying in vacuo.
8
Si—Al—Ti
Bu 2 Mg
Toluene
BPFB
100 g of silica-alumina-titania cogel is slurried
in 1L of toluene and cooled to 0° C. 200 mmol of
DBM is added as a toluene solution and mixed for
1 hour. The slurry is warmed to RT for 4 hours.
The support is filtered, washed and dried in
vacuo. 20 g of this support is slurried 200 mL of
hexanes under an argon atmosphere and cooled to
−78 ° C. 80 mmol of BPFB is added as a hexane
solution and the reaction media is mixed for 1
hour. After warming to RT the slurry is stirred
an additional 4 hours prior to filtering,
washing and drying in vacuo.
9
H—PS
Bu 2 Mg
Toluene
BPFB
100 g of poly(hydroxystyrene) is swollen in 1L of
toluene and cooled to 0° C. DBM is added as a
toluene solution to deprotonate the polymer and
mixed for 1 hour. The slurry is warmed to RT
for 4 hours. The support is filtered, washed
and dried in vacuo. 20 g of this support is
slurried 200 mL of toluene under an argon
atmosphere and cooled to −78° C. BPFB is added as
a toluene solution to react with the formed
phenoxide anions and the reaction media is mixed
for 1 hour. After warming to RT the slurry is
stirred an additional 4 hours prior to
filtering, washing and drying in vacuo.
10
PVA
NaAc
H 2 O
TFMI
100 g of poly(vinylalcohol) is dissolved in 1L of
water and cooled to 0° C. Sodium acetate is added
as an aqueous solution and mixed for 1 hour.
The slurry is warmed to RT for 4 hours. The
support is filtered, washed and dried in vacuo.
20 g of this support is slurried 200 mL of
pentane under an argon atmosphere and cooled to
−78° C. TFMI is added as a pentane solution and
the reaction media is mixed for 1 hour. After
warming to RT the slurry is stirred an
additional 4 hours prior to filtering, washing
and drying in vacuo.
EX.
Carrier
Activator
COMMENTS
11
Ex. 5
BF 15
The support is slurried in hexane and cooled to −78° C. under an
atmosphere of dry, deoxygenated argon. t-Butyllithium is added
to debrominate the supported organic moiety. The slurry is
warmed to room temperature and a solution of BF 15 is added. The
slurry is mixed a further 2 hours and the solid is filtered,
washed and dried in vacuo.
12
Ex. 1
[DMAH][BF 20 ]
The support is slurried in hexanes and [DMAH][BF 20 ] is added as
a solution. After one hour of mixing the solvents are removed
in vacuo.
13
Ex. 3
[DMAH][BF 20 ]
The support is swollen in toluene and [DMAH][BF 20 ] is added as a
solution. After one hour of mixing the solvents are removed in vacuo.
14
Ex. 8
[DMAH][BF 20 ]
The support is slurred in hexanes and a mixture of [DMAH][BF 20 ]
Cp 2 ZrMe 2
and Cp 2 ZrMe 2 is added as a solution at 0° C. After one hour of
mixing the solvents are removed in vacuo.
Polymerization Example
EXAMPLE 15
The Support
SiO 2 ,available from Grace Davison, a business unit of W. R. Grace Co.-Conn., as Sylopol® 948 (30 g, previously calcined at 800° C. for 4 hours), was slurried in 150 mL of hexanes under an atmosphere of purified argon and cooled to 0° C. A hexane solution of n-BuLi (80 mmol) was added and mixed for 2 hours at 0° C. After warming to RT, the slurry was mixed an additional 16 hours. The slurry was recooled to 0° C. and neat bromopentafluorobenzene (100 mmol) was added. After mixing 1 hour at 0° C., the slurry was warmed to RT and mixed a further 16 hours. The liquid phase was removed and the solids washed with hexanes (3 times with 75 mL). The solid was dried in vacuo.
EXAMPLE 16
The Supported Activator
To Example A (2.4 g) was added toluene (50 mL) under an atmosphere of dry, deoxygenated argon. A toluene solution of [DMAH][BF 20 ] (50 mL, 1 mmol) was added to the foregoing slurry. The light green slurry was mixed for 1 hour. The liquid phase was removed and the solids washed with hexanes (3 times with 50 mL). The solid was dried in vacuo.
EXAMPLE 17
The Support Catalyst System
A 500 mL polymerization vessel was charged, in order, with heptanes (150 mL), TEAL (1 mmol), Example B (100 mg) and zirconocene dichloride (40 mmol) under an atmosphere of dry, deoxygenated argon at 40° C. The reactor was refilled with ethylene to a pressure of 45 psig after evacuation. Polymerization was carried out for 30 minutes and was quenched by rapid venting of monomer followed by methanol (50 mL). The polymer was washed with methanol and dried more than 12 hours in a vacuum oven at 60° C. to yield 15 g of polyethylene.
|
The present invention is directed to a supported catalytic activator composition resulting from the contact of a catalyst support (formed by reaction of a carrier, such as an inorganic oxide (e.g., silica) and an organo halide such as bromo pentafluorobenzene in the presence of base) and a catalytic activator such as dimethylanilinium tetrakis (pentafluorophenyl) borate, and methods for making the same.
| 2
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FIELD OF THE INVENTION
The present invention relates to bidet devices of the type which are added to an existing toilet.
BACKGROUND
Bidet devices are known as described in my prior U.S. Pat. No. 5,933,881 the disclosure of which is hereby incorporated by reference. This device of my prior patent provides a structure for attachment thereof to an existing toilet (water closet) and which supports a valve structure for (1) positioning the spray tube and for turning on the supply of water. The flow and pressure of water through the spray tube and the spray holes thereof are dependent upon the water line pressure at the toilet, less any friction losses through fittings and the spray holes. Thus, if the line pressure is relatively constant, the flow and pressure and hence velocity of the water emitted from the spray tube holes will remain relatively constant as well. For the user to decrease the flow/pressure/velocity of the water or to turn it off completely to prevent, for example, a child from playing with the device, the user would have to turn off the supply of water to the device and toilet at, for example, an on/off valve at the wall behind the toilet.
There is a need for an improvement which provides for a simple, economical means to control flow/pressure/velocity of the water emitted by the device and to turn off the flow. Since the device may be operated by handicapped individuals, there is also a need for a flow control device which is position for easy, one hand control. There is further a need for the flow control to be ergonomically incorporated into the bidet device.
SUMMARY OF THE INVENTION
There is, therefore, provided according to the present invention an improved bidet device which provides for modulating the flow rate and pressure of the liquid flowing though the spray tube when the spray is activated. The improved bidet includes the handle coupled to a hollow capstan rotatable with the handle. The capstan has at one end a first hole adapted to communicate with a supply of water and at the other end a second radial hole adapted to communicate with the tube. At the second end the capstan further has internal threads. A screw having a hollow shank with external threads is configured to be threadably received into and close said capstan second end and to couple a handle to the capstan for rotation of the capstan with the handle to position the tube and open and close the supply of water through the capstan and tube. The screw shank further includes a radial port to rotatably register with the capstan second hole. An actuator is coupled to the screw to rotate the screw relative to the handle to position the port between a closed position where the port is positioned to not register with the second opening to prevent the flow of water to a full open position where port is fully registered with the second hole for full flow of water through the tube to modulate the flow and pressure of water though the tube and spray holes of the tube.
Thus the user can set the actuator to moderate the pressure and flow of water through the tube and spray holes of r the comfort of the user. One the actuator is position, the user need only move the handle to open the supply of water through the capstan and tube at the flow/pressure set by the actuator. Further the actuator can be set to close the supply of water to prevent inadvertent actuation of the bidet as by, for example, children.
In a further embodiment, the actuator may be ergonometrically shaped having a tear drop-shaped plan to define an arcuate surface to mate with the thumb for actuation of the actuator apart from actuation of the handle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, with a part broken away, of a portion of a prior art apparatus;
FIG. 2 is a perspective view of apparatus of FIG. 1;
FIG. 3 is a side elevation of a water tube in FIG. 1;
FIG. 4 is a plan view, with a part broken away, of the apparatus of FIG. 1;
FIG. 5 is a side elevation, with parts broken away, of a valve block and a hose bib of FIG. 1;
FIG. 6 is a front view of a valve chamber insert of FIG. 5;
FIG. 7 is side elevation of the valve chamber insert of FIG. 6;
FIG. 8 is a bottom view of the valve chamber insert of FIG. 7;
FIG. 9 is a view of the valve chamber insert of FIG. 7 taken along the line 9 — 9 ;
FIG. 10 is a view of the valve chamber insert of FIG. 5 taken along the line 10 — 10 ;
FIG. 11 is a side elevation, with parts broken away, of a handle of the apparatus of FIG. 2;
FIG. 12 is a view of FIG. 11 taken along the line 12 — 12 ;
FIG. 13 shows various orthogonal views of the transfer tube according to the present invention;
FIG. 14 shows orthogonal and section views of the handle according to the present invention;
FIG. 15 shows various orthogonal and section views of the flow control and shut-off screw according to the present invention; and
FIG. 16 shows orthogonal views of the flow control actuator.
DESCRIPTION
1. The Existing, Prior Device
As shown in FIGS. 1-4, a cleansing apparatus 10 (FIG. 2) includes an L shaped toilet mounting frame 12 that is preferably made from plastic. The frame 12 has a long side 14 with a pair of mounting holes 16 that have a spacing there between that is substantially equal to the spacing between mounting holes of a toilet seat. The spacing between the toilet seat mounting holes is standardized in the United States.
The long side 14 is positioned upon the rear of the exterior of a toilet bowl 18 (FIG. 1) of a toilet, with the holes 16 aligned with corresponding holes (not shown) of the bowl 18 . A short side 20 of the frame 12 extends on the exterior of the bowl 18 along an outer edge 22 thereof.
A toilet seat 24 includes a hinged section 26 where the toilet seat mounting holes are located. Mounting bolts (not shown) pass through the holes of the bowl 18 , the holes 16 and the toilet seat mounting holes whereby the long side 14 is sandwiched between the rear of the exterior of the bowl 18 and the hinged section 26 . The bolts are screwed into nuts (not shown).
A plurality of standoffs 28 are connected to the bottom of the seat 24 in any suitable manner. The standoffs 28 create a space between the seat 24 and a rim 30 of the bowl 18 that is used in a manner described hereinafter. The use of a standoff to create a space between a toilet seat and a toilet bowl is well known in the art and is commonly provided on standard toilet seats.
A plastic spacer strip 32 (FIG. 2) is cemented between the short side 20 and a plastic component strip 34 . The strip 34 has a surface 36 whereon a plastic valve block 40 is carried. A plastic handle 42 is carried on a surface 38 of the strip 34 . The handle 42 is rotatable upon the surface 38 about a screw 44 . The valve block 40 is connected to a hose bib 46 .
A proximal end 51 of a plastic water tube 50 extends from an end 48 of the handle 42 . More particularly, the tube 50 extends horizontally from the end 48 . Because of the strip 32 , the tube 54 passes beneath the seat 24 , over the rim 30 (FIG. 1) to the interior of the bowl 18 via the space created by the spacers 28 .
The tube 50 has a first right angle bend 52 (FIGS. 1-3) that causes a distal portion 54 (FIG. 3) of the tube 50 to extend below the rim 30 . The tube 50 additionally has a second right angle bend 56 that causes the distal portion 54 to extend over water within the bowl 18 . The distal portion 54 has a plurality of longitudinally aligned holes 58 therein (FIGS. 1 - 4 ).
In response to water being provided to the proximal end 51 , a sheet of water is discharged from the holes 58 . The orientation of the holes 58 causes the sheet of water to be directed toward the underside of the torso of a person seated upon the seat 24 .
The sheet of water has been found to cause less splashing and provide superior cleansing than a fountain of water typically produced by devices of the prior art. Additionally, a wide coverage provided by the sheet of water obviates both the lateral movement of the person and a precise targeting of the water.
The tube 50 is at a withdrawn location when the distal portion 54 is withdrawn to a rear portion 60 of the bowl 18 (FIG. 4 ). When the tube 50 is withdrawn, the toilet can be used for the usual toilet facility activities without the tube 50 be subjected either to droppings of fecal matter or urine. For reasons explained hereinafter, water is not discharged from the holes 58 when the tube 50 is withdrawn. When the tube 50 is not withdrawn, water that flows into the hose bib 46 , passes through the valve block 40 and the handle 42 to the tube 50 . The water is discharged from the holes 58 .
When, for example, the handle 42 is rotated to cause the distal portion 54 to pivot to a location 62 , the tube 50 is in an anal cleansing position, whereby the sheet of water cleanses the anus of a woman seated upon the seat 24 . When the handle 42 is rotated to cause the distal portion 54 to pivot to a location 64 , the tube 50 is in a vaginal cleansing position whereby the sheet of water cleanses the woman's vagina. It should be understood that the handle 42 is rotatable to cause the distal portion 54 to be at any location that is intermediate to the locations 62 , 64 whereby the sheet of water is moved to cleanse the woman's perineal skin area.
As shown in FIG. 5, the hose bib 46 has a mid-section 66 in the shape of a hexagonal bolt head. The hose bib 46 additionally has a threaded end 68 and a scalloped end 70 . As explained hereinafter, the end 68 is screwed into the valve block 40 . Hose bibs are well known to those skilled in the art.
A passageway 72 within the valve block 40 extends from a widened threaded section 74 thereof to a valve chamber 76 . The end 68 screws into the threaded section 74 . A wrench (not shown) may be used to turn the mid-section 66 to screw the end 68 into the threaded section 74 .
The passageway 72 includes a coupling section 80 that has the general shape of a funnel. A wide end 82 of the coupling section 80 is connected to the threaded section 74 . A narrow end 84 of the coupling section 80 is connected to one end of a narrowed cylindrical section 86 of the passageway 72 ; the other end is contiguous with an opening in the valve chamber 76 . Accordingly, there is a path for water that extends from the hose bib 46 to the valve chamber 76 .
A valve stem 88 is disposed mostly within the passageway 72 . The valve stem 88 has a rounded end 90 . The end 90 extends into the interior of the valve chamber 76 .
The valve stem 88 additionally has an end 91 that has the shape of a right truncated cone. The end 91 is disposed within the coupling section 80 .
The pressure of water provided via the hose bib 46 urges the valve stem 88 to move in the direction of an arrow 92 . Because of its conical shape, the end 91 occludes the passageway 72 to prevent a flow of water to the valve chamber 76 . As explained hereinafter, the passageway 72 is cleared when the handle 42 is rotated to cause the tube 50 to move from the rest position.
A hole 94 extends from the valve chamber 76 to a top surface 98 of the valve block 40 . The hole 94 is coaxial with a hole 100 through the strip 34 . The holes 94 , 100 have substantially the same diameter.
A hole 102 extends from the valve chamber 76 through a bottom surface 104 of the valve block 40 . A plastic valve chamber insert 106 is inserted through the hole 102 into the valve chamber 76 . The insert 106 includes a transfer tube 108 that has a section 109 that protrudes through the hole 100 . The transfer tube 108 has a generally cylindrical shape. After the insertion, the hole 102 is sealed by a plastic sheet 110 that is cemented to a bottom surface 104 of the valve block 40 .
As shown in FIGS. 6-8, the insert 106 includes a disc 112 with a surface 114 that is integrally connected to a cylindrical capstan 116 . The disc 112 and the capstan 116 are coaxial.
A coil spring 118 (FIG. 5) is wound about the capstan 116 . One end of the spring 118 (not shown) is fixedly connected to the capstan 116 ; the other end is fixedly connected to the wall of the valve chamber 76 . The purpose of the spring 118 is explained hereinafter.
The disc 112 is integrally connected to a support member 122 (FIGS. 6 - 8 ). A surface 124 (FIG. 8) of the capstan 116 and a surface 126 of the member 122 are rotatably supported upon the sheet 110 (FIG. 5 ). Accordingly, a rotary movement of the insert 106 causes a corresponding rotary sliding movement of the capstan 116 and the member 122 upon the sheet 110 .
As shown in FIGS. 9 and 10, with continuing reference to FIGS. 6 and 7, the insert 106 additionally includes a disc 128 with a surface 130 that is integrally connected to vanes 132 - 134 (FIG. 9) at distal ends thereof. Proximal ends of the vanes 132 - 134 (FIG. 10) are integrally connected to a surface 136 of the disc 112 .
The insert 106 is rotatable to cause the vane 132 to move the end 90 in a direction opposite from the direction of the arrow 92 , thereby clearing the passageway 72 . The purpose of the vanes 133 , 134 is to provide structural support for a separation that is maintained between the discs 112 , 128 .
It should be understood that the range of angles of rotation of the insert 106 that causes the vane 132 to clear the passageway 72 is directly related to the widths of the vane 132 and the end 90 . The widths are chosen to cause the passageway 72 to be cleared when the location of the distal portion 54 is within a range substantially defined by the locations 62 , 64 . As explained hereinafter, the rotation of the discs 112 , 128 is caused by a corresponding rotation of the handle 42 .
The disc 128 has a central hole 137 there through that extends to an intersection of the vanes 132 - 134 (FIG. 9 ). Additionally, a hole 138 extends through an intersection of the vanes 132 , 133 to an edge of the vane 134 . There is substantially a ninety-degree angle of intersection between the holes 137 , 138 .
The transfer tube 108 has an axial hole 140 that is contiguous with the hole 137 . The holes 137 , 140 have substantially the same diameter.
The protruding section 109 has a discharge hole 142 therein that has an angle of intersection of substantially ninety degrees with the hole 140 . The protruding section 109 additionally has a flattened outer surface 144 in the region of the hole 142 . Therefore, when the passageway 72 is cleared, water that enters the valve chamber 76 passes through the transfer tube 108 and is discharged therefrom through the discharge hole 142 . The path of water through the discharge tube 108 is along a path A—A shown in broken lines (FIGS. 6 and 7 ). As explained hereinafter the flattened wall 144 is used to couple the tube 108 to the handle 42 . As shown in FIGS. 11 and 12, the handle 42 has a generally cylindrical coupling hole 146 therein that has substantially the same diameter as the transfer tube 108 (FIGS. 6 and 7 ).
An outlet hole 148 extends through the end 48 and has an angle of intersection of substantially ninety degrees with the coupling hole 146 . The proximal end 51 is disposed within the hole 148 and is preferably cemented therein whereby the tube 50 extends from the end 48 as described hereinbefore.
The coupling hole 146 has a flattened surface 150 in the region of the intersection with the hole 148 . In this embodiment, the shape of the coupling hole 146 is complimentary to the shape of the protruding section 109 .
The protruding section 109 is disposed within the coupling hole 146 with the flattened surfaces 144 , 150 in an abutting relationship. The complimentary shapes prevent a rotation of the handle 42 relative to the transfer tube 108 . In other words, when the handle 42 is rotated, the insert 106 is rotated. Hence, the handle 42 is rotatable to cause either the occlusion or the clearing of the passageway 72 . Moreover, the occlusion occurs when handle 42 is rotated to cause the tube 50 to be in the rest position.
The holes 142 , 148 are in an alignment that is maintained by the complimentary shapes. The alignment is essential to providing a desired transfer of water through the transfer tube 108 to the tube 50 through the handle 42 .
The spring 118 urges the transfer tube 108 to rotate in a direction that results in the occlusion the passageway 72 . Because the relative rotation is prevented, the handle 42 is urged to rotate in a direction that moves the tube 50 to the rest position. Therefore, when the woman releases the handle 42 , the tube 50 is rotated to the rest position and no water flows there through, whereby the toilet can be used for usual toilet facility activities.
Preferably, an O-ring 152 (FIG. 5) is maintained about the transfer tube 108 to prevent a leakage of water from the valve block 40 between the transfer tube 108 and the hole 94 . Similarly, an O-ring 154 (FIG. 11) is preferably retained within a recess 156 within the handle 42 to prevent a leakage of water from the coupling hole 146 .
The coupling hole 146 is contiguous with a cylindrical coupling section 158 within the handle 42 . The coupling section 158 is contiguous with an O-ring recess 160 that extends through a top surface 162 of the handle 42 . Additionally, the hole 140 is contiguous with a threaded hole 164 (FIGS. 6 and 7) that extends through a top 166 of the protruding section 109 .
When the protruding section 109 is within the coupling hole 146 , the screw 44 is screwed into the hole 164 , thereby securely connecting the handle 42 to the transfer tube 108 . Additionally, an O-ring 167 is disposed within the recess 160 to prevent a leakage of water from the coupling hole 146 . O-rings are well known in the art.
The hose bib 46 is connected at its scalloped end 70 (FIG. 1) to a water heater 168 at an outlet end 170 thereof through a flexible tube 172 . An inlet end 174 of the heater 168 is connected through a TEE connector 176 and a flexible tube 178 to a manual control valve 180 at an outlet port 182 thereof whereby water from the port 182 is available to the hose bib 46 via the heater 168 .
The heater 168 has a manual control knob 184 that is adjustable to cause water provided at the outlet end 170 to be at a desired temperature. The heater 168 is of a type well known in the art.
Preferably, the heater 168 includes a compartment where medication may be placed for a timed release into the water provided at the outlet end 170 whereby a medicated solution is provided at the outlet end 170 . The medicated solution may be desirable when a woman who has had an episiotomy uses the apparatus 10 . Apparatus for providing the timed release of the medication is well known to those skilled in the art.
The tee connector 176 is additionally connected to a toilet water tank 186 at an input port 188 whereby water is available within the tank 186 to flush the bowl 18 . Toilet water tanks are well known to those skilled in the art.
2. The Present Invention
Turning to FIG. 13, the transfer tube 108 ′ of the present invention is shown. The transfer tube 108 ′ is substantially similar to the tube 108 including an upstanding section 109 , capstan 116 , discharge hole 142 fashioned in a flat 143 and which communicates with an axial hole 140 . The axial hole 140 , in turn, is in communication with the water flow passageway 72 through hole 138 . The axial hole 140 , proximate the end of the section 109 opposite the capstan 116 is threaded to receive the screw 44 ′ of the present invention. Further the flat 143 extends to the end of the section for purposes of which will hereinafter become evident. The tube 108 ′ may be fashioned from a suitable plastic.
To rotate the transfer tube 108 ′ the handle 42 ′ of the present invention is provided. The handle 42 ′ may be ergonomically designed and includes a head 99 with a hole 100 ′ there through which is configured to pass and mate with the top of the transfer tube 108 ′ as well as accommodate the end 51 of the water tube 50 as in FIG. 11 . The hole 100 ′ has a stepped countersink 101 to receive the screw 44 ′ head 51 .
To secure the handle 42 ′ to the transfer tube 108 ′, the screw 44 ′ is provided. Unlike the screw 44 of my prior patent, screw 44 ′ has a threaded shank 45 with an axial bore 47 which emerges from a side of the shank 45 to define a port 49 . The shank 45 is threaded and sized to be closely received and threaded into the threaded end of the transfer tube 108 ′. Rotation of the screw 44 ′ opens and closes the hole 142 by registering all or a portion of the port 49 with the hole 142 to control the pressure/flow of he water through the transfer tube 108 ′ to the water tube 50 . The screw 44 ′ also mounts the handle 42 ′ to the transfer tube 108 ′. Manipulation of the handle 42 ′ swings the tube 50 into position for the water flowing there through and though the port 49 of the screw 42 ′ to flow through the holes 58 . Thus it can be appreciated that the handle 42 ′ swings the tube 50 and registers the hole 158 with the passageway 72 to pass the water through hole 140 and port 49 out through the tube 50 . The flow and pressure of the water is controlled by the port 49 which can open and close the hole 142 and modulate the flow of the water to the tube 50 and holes 58 .
With reference to FIG. 15, he screw 44 ′ may be provided with a recessed shoulder 155 to retain a sealing elastomeric washer (not shown). The head 51 also includes a flat 53 .
To couple the handle 42 ′ to the transfer tube 108 ′ the handle 42 ′ hole 100 ′ includes a flat (not shown) to mate with the flat 143 of the transfer tube 108 ′.
To provide an ergonometric actuator for the flow control, the device of the present invention includes a flow control actuator 300 as shown in FIG. 16 . The actuator 300 may be of any suitable shape such as a tear drop shape as shown which defines arcuate surface 301 to be engaged by the thumb or finger for rotation of the actuator 300 . At the underside of the actuator 300 is a cylindrical recess 302 having a flat 304 to closely receive and mate with the head 51 of the screw 44 ′. The actuator 300 is secured to the screw 44 ′ head 51 by a suitable adhesive. The actuator 300 when mounted to the screw 44 ′ head 51 is disposed on top of the top surface of the handle 42 ′ with the actuator poised for control by a finger or the thumb. In a first position, the actuator 300 is disposed to permit the water to flow through the tube 52 at full water line pressure when the handle 42 ′ is manipulated. At this position the actuator 300 engages a stop 306 on the handle 42 ′ (FIG. 14) to prevent over rotation of the actuator 300 . At a second position, the actuator is rotated approximately 180 degrees to engage the stop 306 on the handle 42 ′ to shut off water flow, regardless of the position of the handle 42 ′ and preventing over-rotation of the actuator 300 . The actuator 300 can also be position anywhere between the first and second positions to modulate the flow of water. Thus the user can modulate flow when the handle 42 ′ is in the “On” position to control flow and pressure of the water or can be preset to the desired modulated position and left in that position for the comfort of the user. The actuator 300 can be placed in the second position to prevent flow regardless of the position of the handle 42 ′.
While I have shown certain embodiments of the present invention it is to be understood that it is subject to modifications and changes without departing from the spirit and scope of the invention.
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An improved bidet device is set forth which includes a rotatable handle and capstan for positioning a spray tube and for opening the supply of water to the tube for spraying. A screw is received by the capstan to mount the handle and is further provided with a radial port. An actuator is coupled to the screw for rotation of the screw relative to the capstan to modulate the flow of water through the device. The actuator may be ergonometrically designed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. Ser. No. 09/712,759, filed Nov. 14, 2000, now abandoned.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to vortex induced vibration suppression and more particularly to an improved apparatus for suppressing vortex induced vibrations in vertical risers of oil and gas well drilling platforms and production platforms. Even more particularly, the present invention relates to an improved vortex induced vibration suppression apparatus, also known as a strake, wherein the improved apparatus includes an elongated body of flexible polymeric material such as polyurethane, the body having a wall surrounding a continuous open-ended bore, a plurality of helical vanes provided on the body, (preferably integral therewith) that extend along the length of the body and a longitudinal slot that extends through the wall enabling the body to be separated such as during placement upon a pipe, riser or pipeline.
2. General Background of the Invention
Vortex induced vibration suppressors are devices that have been used commercially to prevent vortex induced vibration. It has been stated that risers such as those associated with TLP type platforms suffer from vortex induced vibration or “VIV”. Floatable and tension leg platform (TLP) risers suffer from vibration induced vortex caused by ocean currents, for example. VIV can be an acute problem in deep water drilling operations. As the current flows around an unsupported pipe such as a pipeline riser, it creates vortices on the leeward side of the pipe. Vortices produce minute pressure fluctuations that create vibrations on the leeward side of the pipe. When these vortices break away from the pipe, they set up vibrations which will dynamically excite the riser and cause the pipe to fail prematurely. Strong currents increase the amount of vortex induced vibration (VIV).
Presently, there are a number of commercially available vortex induced vibration suppressors. One such product is available from Mark Tool Company of Lafayette, La. Another commercially available vortex induced vibration suppressor is available from CRP Marine Products of England. Another commercially available vortex induced vibration suppressor or “strake” system is being commercialized by Dunlaw of Aberdine, Scotland. Another device that is commercially available and that suppresses vortex induced vibration is sold under the mark Uraduct® VIV.
One of the problems of placing a vortex induced vibration suppressor on an oilfield riser pipe such as the riser associated with a deep water oil and gas well drilling or production platform is the problem of installing or placing the strake. This problem can be solved by using an underwater diver or divers. However, such a procedure is dangerous and very costly. Some VIV devices have multiple parts that limit overall structural strength.
BRIEF SUMMARY OF THE INVENTION
The present invention provides an improved method and apparatus for solving the problem of vortex induced vibration by providing a suppression apparatus of improved construction that features an elongated body of flexible polymeric material (for example polyurethane), the body having a wall surrounding a continuous, open-ended bore.
A plurality of helical vanes are provided on the body, extending along the length thereof.
A longitudinal slot extends through the wall, enabling the body to be separated to afford access to the bore (such as during placement on a pipe or riser). In another embodiment, the apparatus can be cast in place on a pipe joint or cast as a one piece strake that is slipped over a pipe and then glued, eliminating the slot and bolted connection.
In the preferred embodiment, the entire elongated body and vanes are of a integrally formed, preferably cast or molded polymeric material (for example, polyurethane). This construction enables the entire elongated body to be flexed as portions of the body are separated apart at the slot.
In the preferred embodiment, the slot extends along one of the vanes, separating the vane into first and second vane portions, each having a surface that abuts a corresponding surface of the other vane portion upon assembly.
The slot is preferably a helically shaped slot that tracks the path of the vane.
A removable connection can hold the body together at the slot. In the preferred embodiment, this removable connection is in the nature of a bolted connection or connections that bolt first and second vane portions together.
This removable connection is preferably comprised of a plurality of regularly spaced apart, bolted connections.
In the preferred embodiment, the slot separates one of the vanes into first and second longitudinally extending vane sections, each having a flat mating surface (or offset for aiding alignment), wherein the flat mating surfaces are engaged, the bolted connections can be perfected to hold them together.
In another embodiment, the present invention provides an improved vortex induced vibration suppression apparatus that features the elongated body and helical vanes with a longitudinal slot that extends through the wall at a vane for enabling the body to be separated to afford access to the bore.
In an alternate embodiment, a spacer is removably attachable to the body, the spacer including a rounded outer surface that enable the spacer and body to be rolled such as during handling upon the deck of a ship or barge. The spacer provides an elongated bore that is shaped to fit the body and its helical vanes.
The present invention provides an improved method of installing a riser having one or more vortex induced vibration suppression devices thereon. The method includes first making up the riser section on a pipeline lay barge that provides a stinger. The vortex induced vibration device or devices is attached to the pipeline on the lay barge. In this fashion, the riser and attached vortex induced vibration suppression devices can be lowered to the seabed by first passing the riser and attached vortex induced vibration suppression devices over the stinger part of the barge. With the present invention, the improved construction of the vortex induced vibration suppression device enables the apparatus to be lowered over a stinger of a lay barge to the ocean floor.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
FIG. 1 is a side view of the preferred embodiment of the apparatus of the present invention;
FIG. 2 is an end view of the preferred embodiment of the apparatus of the present invention taken along lines 2 — 2 of FIG. 1;
FIG. 3 is an end view of the preferred embodiment of the apparatus of the present invention and showing part of the method of the present invention wherein the vortex induced vibration suppression apparatus is being separated at its slot for installation;
FIG. 4 is another end view illustrating the preferred embodiment of the apparatus of the present invention and showing the optional method step of applying an adhesive to the inside wall surface thereof and is part of the method of the present invention;
FIG. 5 is a perspective view of the preferred embodiment of the apparatus of the present invention and illustrating one of the method steps of the present invention, namely the application of the vortex induced vibration suppression device to a riser;
FIG. 6 is a perspective view showing the preferred embodiment of the apparatus of the present invention and illustrating part of the method of the present invention, namely the application of fasteners such as bolted connections to the apparatus after placement upon a riser;
FIGS. 7A-7B are side views of the preferred embodiment of the apparatus of the present invention showing the device after placement upon a riser;
FIG. 8 is an elevation schematic view showing the method of the present invention, namely the step of lowering the riser and attached vortex induced vibration suppression devices from a pipeline lay barge to the ocean floor;
FIG. 9 is an elevation, schematic view of the preferred embodiment of the apparatus of the present invention illustrating the method of the present invention, showing several vortex induced vibration suppression devices mounted to a riser and showing a riser and connected devices positioned next to an offshore oil and gas well drilling/production platform;
FIG. 10 is an exploded view of the preferred embodiment of the apparatus of the present invention; and
FIG. 11 is an end view of the preferred embodiment of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1-11 show the preferred embodiment of the apparatus of the present invention, designated generally by the numeral 10 .
Vortex induced vibration suppression device 10 includes body 11 having a central longitudinal open ended bore 12 and end portions 13 , 14 .
Body 11 is preferably a one piece, molded or cast flexible body that is preferably of a polymeric material such as polyurethane. A plurality of helical vanes 15 , 16 , 17 extend from the wall 30 of body 11 and are preferably integral therewith. A longitudinally extending slot can be optionally formed by mating surfaces 20 , 21 of vane sections 18 , 19 as shown in FIGS. 1-4. Otherwise, body 11 does not have a slot but is a one piece integral member that can be installed by slipping it over an end of a joint of pipe. It can also be case in place on a joint of pipe.
A hinge area 29 is provided generally opposite vane sections 18 , 19 and the respective mating surfaces 20 , 21 . A user can spread apart the vane sections 18 , 19 as shown by arrows 34 in FIG. 3 for enabling a technician 25 to apply an adhesive 23 using a desired tool or implement such as dispenser 24 to the inside surface 22 of body 11 . During this procedure, a spreader bar 26 can be used to hold the vane sections 18 , 19 apart as shown in FIGS. 3-5.
The vane section 18 provides a plurality of longitudinally extending, spaced apart openings 27 . The openings 27 align with a corresponding plurality of longitudinally extending, spaced apart openings 28 through vane section 19 . After an adhesive is applied to inside surface 22 of wall 30 of body 11 , the body 11 can be placed upon a pipeline riser section 32 as indicated schematically by arrow 35 in FIG. 5 . Arrow 36 in FIG. 5 schematically illustrates the removal of spreader bars 26 once the body 11 is placed upon riser section 32 .
When properly assembled upon a pipeline riser section 32 as shown in FIG. 6, the wall 30 outer surface 31 provides a smooth contour that is substantially similar in curvature to the outside surface of the pipeline riser section 32 .
The adhesive 23 is designed to form a good bond between body 11 and the outside surface 33 of pipeline riser section 32 . A plurality of bolted connections 40 can be used to bolt vane sections 18 , 19 together to further secure each body. 11 to its pipeline riser section 32 . In FIG. 6, each bolted connection 40 includes bolt 37 , nut 38 and a plurality of washers 39 if desired.
The method the present invention is further illustrated in FIGS. 8-9 and 10 - 11 . In FIG. 8, a pipeline lay barge 41 is shown having a deck 42 upon which is stacked a plurality of pipe joints 43 . The pipeline lay barge 41 also includes a welding area 44 that enables a plurality of the pipe joints 43 to be welded together end-to-end as known in the art. A stinger 45 is also provided with lay barge 41 . Such a lay barge 41 and stinger 45 are well known in the art.
According to the method of the present invention, the vortex induced vibration suppression devices 10 of the present invention are assembled to the welded pipeline riser 47 before the riser 47 is lowered to the seabed 50 via stinger 45 . In FIG. 8, the arrow 46 schematically illustrates a riser 47 that is fitted with a plurality of vortex induced vibration suppression devices 10 . The combination of pipeline riser 47 and its vortex induced vibration suppression devices 10 or “strakes” are lowered over the stinger 45 as indicated by arrow 46 . To further schematically illustrate the method of the present invention, the surrounding ocean 49 is also shown with water surface 48 and seabed 50 .
In FIG. 9, an offshore platform 53 is shown. It should be understood that platform 53 can be an offshore oil and gas well drilling and/or production platform. Such a platform 53 is typically supported with support 52 that can be a semisubmersible, TLP or jacket type foundation or any other marine platform support known in the art. In FIG. 9, the numeral 51 schematically indicates the entire marine structure that includes support 52 and platform 53 .
In FIGS. 10 and 11, a plurality of spacers 54 are shown that are attachable to one of the bodies 11 . As shown in FIGS. 10 and 11, three spacers 54 can be added to a single body 11 in order to transform it into a cylindrically shaped member that can be easily rolled for ease of transport and ease of installation. Each spacer 54 has end portions 55 , 56 . Each spacer has a concave surface 57 and a convex surface 58 . The concave surfaces 57 are shaped to conform to the outside surface 31 of body 11 in between two adjacent vanes such as 15 , 16 or 16 , 17 . Each spacer 54 provides side beveled edges 59 , 60 that fit next to a vane 15 , 16 , 17 as shown in FIG. 10 .
In FIG. 11, three spacers 54 are shown attached to a single body 11 . A plurality of straps (not shown) can be used to encircle the combination of spacers 54 and body 11 to thereby secure the spacers 54 to the body 11 until they are to be removed. Typically, this removal can be accomplished just before the body 11 is to be transported to an end user or job site.
As an alternate embodiment, the polymer (eg. polyurethane) has a copper nickel particulate dust contained therein. This mixture of polymer and copper nickel particulate dust enhances antifouling capability of the strake.
PARTS LIST
The following is a list of suitable parts and materials for the various elements of the preferred embodiment of the present invention.
10
vortex induced vibration
suppression device
11
body
12
bore
13
end portion
14
end portion
15
helical vane
16
helical vane
17
helical vane
18
vane section
19
vane section
20
mating surface
21
mating surface
22
inside surface
23
adhesive
24
dispenser
25
technician
26
spreader bar
27
opening
28
opening
29
hinge area
30
wall
31
outer surface
32
pipeline riser section
33
outer surface
34
arrow
35
arrow
36
arrow
37
bolt
38
nut
39
washer
40
bolted connection
41
pipeline lay barge
42
deck
43
pipe joint
44
welding area
45
stinger
46
arrow
47
welded riser
48
water surface
49
ocean
50
seabed
51
marine structure
52
support
53
drilling/production platform
54
spacer
55
end portion
56
end portion
57
concave surface
58
convex surface
59
beveled edge
60
beveled edge
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 vortex induced vibration suppressor and method is disclosed. The apparatus includes a body that is a flexible member of a polymeric (eg. polyurethane) construction. A plurality of helical vanes on the body extend longitudinally along and helically about the body. A longitudinal slot enables the body to be spread apart for placing the body upon a riser, pipe or pipeline. Adhesive and/or bolted connections optionally enable the body to be secured to the pipe, pipeline or riser.
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FIELD OF THE INVENTION
[0001] The present invention relates to a cooling system for an internal combustion engine and more particularly relates to an oil cooling system for both combustion ignition and diesel engines, collectively internal combustion (IC) engines.
BACKGROUND OF THE INVENTION
[0002] Most internal combustion engines require a cooling circuit having a coolant pump, radiator and passageways which circulate a coolant from the radiator through the engine block to cool the engine block and the moving components in the engine block. Lubricants, typically a synthetic or mineral-based oil, are utilized to lubricate the relatively moving surfaces in the engine to counteract friction, reduce wear and reduce operating temperatures.
[0003] However, excessive heat generated in the operation of the engine may cause the oil to degrade and break down losing its lubricating ability. When motor oils break down, they oxidize, thermally degrade and lose viscosity due to shear forces. As a result, many internal combustion engines, particularly high speed diesel engines and high performance combustion ignition engines, utilize engine block mounted oil coolers. Oil from the engine is passed through a cooler which operates as a heat exchanger with heat exchanger fluid, usually water and glycol, being provided from the engine cooling system from either the radiator or the engine block.
[0004] However, since the opening temperature of the thermostat in cooling systems of most internal combustion engines is approximately in the range of 180° to 200° Fahrenheit, an oil cooler utilizing engine coolant as the heat exchanger fluid is limited in its ability to cool the engine oil. By the operation of the cooling system thermostat in many engines, an oil temperature of approximately 200° to 220° F. is maintained so that the oil effectively lubricates and does not break down or degrade. Further, a low oil temperature is preferred because the oil, in addition to being a lubricant, also serves to cool the internal combustion engine components.
[0005] In a coolant to oil cooler system, the engine oil temperature is dependent upon the coolant supply. In the event of even a minor coolant loss, the engine may be damaged as the engine will incur the cooling loss provided both by the coolant and the engine oil.
[0006] Accordingly, there exists a need for an improved coolant to oil cooler system for IC engines which obviates the deficiencies set forth above.
BRIEF SUMMARY OF THE INVENTION
[0007] Briefly, the present invention provides a cooling system which replaces the conventional engine mounted coolant-to-oil heat exchanger with an external, high-capacity air-to-liquid heat exchanger. An adaptor block or manifold is configured to replace an existing Original Equipment Manufacturer (OEM) engine oil cooler and is mounted in place on the engine block utilizing the existing mounting and similar hardware and gaskets that secure the conventional engine oil cooler in place.
[0008] The manifold is configured or ported with a passageway to receive the hot, unfiltered oil from the engine and directs the oil to a cannister-style oil filter of the type having a replaceable cartridge. The filter may be located immediately adjacent to the manifold or may be at a remote location within the engine compartment. Filtered oil from the oil filter is directed to an external heat exchanger, preferably a high-capacity air to liquid heat exchanger, which returns the cooled and filtered oil to the manifold which, in turn, returns cooled and filtered oil to the engine. The system may also include separate bypass filtration and a particle filtration screen within the manifold, as well as an oil bleeder valve and an anti-siphon valve. Suitable provision is made in the manifold for installation of sensors to measure engine operating parameters such as oil pressure and temperature. Further provision can be made for oil supply to an accessory such as a turbo charger.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The above and other advantages and objects of the present invention will become more apparent when taken in conjunction with the following description, claims and drawings in which:
[0010] FIG. 1 is a schematic representation of an embodiment of a cooling system according to the present invention;
[0011] FIG. 2 is a detailed perspective view of the adaptor or manifold section of the cooling system shown in FIG. 1 ;
[0012] FIG. 3 is a plan view of the bottom of the manifold showing a representative 5 mounting configuration which is adapted to replace the conventional OEM oil cooler;
[0013] FIG. 4 is a cross-sectional view of a section of the manifold illustrating the air bleed valve;
[0014] FIG. 5 is a schematic view of an engine oil by-pass that may be incorporated into the cooling system;
[0015] FIG. 6 is a schematic view showing the oil by-pass of FIG. 5 incorporated in the system of FIG. 1 ; and
[0016] FIG. 7 is a schematic showing a modified system as shown in FIG. 6 further including both coolant-to-oil and air-to-oil heat exchangers with by-pass features to provide warming of the engine oil upon start-up.
DETAILED DESCRIPTION
[0017] Turning now to the drawings, FIG. 1 shows the cooling system of the present invention mounted in place on the cylinder block B of an IC engine which is represented schematically by dotted lines. The mounting location may vary depending on the engine configuration. The IC engine may be a CI or diesel having an engine mounted cooler 8 which is removed and replaced with a manifold 11 . The system indicated by the numeral 10 includes a housing or manifold 11 which may be cast and machined from a single block or billet of material such as steel or aluminum. Preferably the underside of the manifold, as best seen in FIG. 3 , is machined to conform to the mounting configuration of the conventional coolant-to-oil cooler mounted on the engine block which cooler has been removed, having bolt holes 19 conforming to the existing bolt pattern. FIG. 3 shows a representative 5 mounting for a 6.0 L International® VT365 diesel engine also known as the 6.0 L Ford® Powerstroke diesel engine (hereinafter referred to as the “6.0 L VT365 diesel engine”) found in a 2004 Ford F350 truck. If the engine has not been originally equipped with an oil cooler, suitable mounting provision for the manifold must be made which may involve appropriate modifications such as tapping the engine block at suitable locations for mounting the manifold and installing suitable hydraulic lines.
[0018] However, in most cases, the cooling system of the present invention will be applicable and is adapted for replacement of a conventional engine mounted IC coolant-to-oil cooler and the following description proceeds on that basis. Once the existing oil cooler is removed, the manifold 11 is secured using suitable hardware and gaskets to position and mount the housing on the engine block B. Port or passageway 25 in the underside of the manifold aligns with a port P in the engine block B through which hot, unfiltered oil is directed to the manifold 11 . The oil enters the manifold at passageway 25 and flows through the manifold 11 exiting at port 13 . Port 13 is connected by a hydraulic line 20 to oil filter 14 . Line 20 has an anti-siphon check valve 21 to prevent reverse flow of oil through line 20 . The oil filter 14 may be located immediately adjacent the manifold 11 or may be at a convenient location in the engine compartment considering engine size, available space and other installation restrictions.
[0019] The oil filter 14 is a canister-type and has an inlet 22 which communicates with and receives oil from the manifold. The housing has a lower screw or spin-on body 24 which is removable. The body 24 contains a suitable element 26 of a filtering material such as paper or fiber which is periodically replaceable. Preferably the filter is a conventional filter available from manufacturers such as FRAM, WIX and others. Particulates and contaminants are substantially removed as the oil passes through the filter element 26 .
[0020] The oil exiting oil filter 14 is then directed to an external heat exchanger, preferably an air-to-liquid heat exchanger 15 . The external heat exchanger may be a tube or plate design and is preferably of the tube type having a tube 28 carrying the oil to be cooled which extends in serpentine fashion within the heat exchanger housing. Because air is a relatively poor conductor of heat, the heat transfer area between the air passing over the tubes is increased by adding fins 30 to the tubes. The heat exchanger 15 is mounted in a location remote from the location of the OEM heat exchanger, preferably located in the vehicle to receive substantial airflow, for example at the front of the vehicle immediately adjacent and in front of the radiator for the engine cooling system. Ducting may be provided to increase airflow to the heat exchanger 15 .
[0021] The oil which has been cooled and filtered is returned to an inlet port 17 on the manifold 11 via line 32 . The inlet port 17 connects with internal passageway 34 communicating with outlet port 12 . The outlet port 12 on the bottom of the manifold is aligned and communicates with the engine block port P so the cooled and filtered oil returns to the engine to provide lubrication. An additional outlet port 12 A, as seen in FIG. 3 , is provided to supply cooled and filtered oil to the high pressure oil pump.
[0022] Additional filtering may be provided by a bypass filter 18 . The bypass filter 18 is a separate filter and may be of the cannister type as described with reference to filter 14 . A bypass line 36 removes a portion of the cooled and filtered oil prior to the oil entering into port 17 and directs the oil to the inlet of the bypass filter 18 . The bypass filter 18 has an outlet which directs the flow via line 38 to port 12 to be returned to the engine. 5
[0023] Passageway 34 connected to port 17 may also be intercepted by passageways 40 , 42 and 44 which are suitably threaded for connection to gauges such as the pressure gauge at 40 , temperature gauge 42 and oil feed for the turbo at 44 . Other sensing locations can also be provided to measure other operating parameters. Provision is made in the manifold to circulate coolant through the engine cooling system. Coolant enters the manifold at port 55 and exits at port 56 where it is returned to the engine cooling system without passing through the external heat exchanger 15 . The coolant thus returned to the engine cooling system is circulated by a water pump through the existing passages in the engine block and radiator.
[0024] In many engines, metal particles will be released during operation. In addition to metal particles, sand used in the engine block casting process and retained in the engine may also be released. These larger, particulate materials can be harmful to the engine and may also quickly clog or reduce the effectiveness of the filters, such as the F1A filter, which are primarily intended to remove finer particulate materials.
[0025] The oil cooling system of the present invention may be provided with a particulate filter internal within the manifold 11 to trap and remove larger particulates which may otherwise quickly impair the effectiveness of element type filters. A cavity 50 is provided within the housing and removably receives a screen 52 having a mesh in the 0.003 to 0.005 inch range. The screen is accessible and removable by detaching the manifold from the engine block or access may be provided through a suitable access panel 54 on the manifold. A portion of the cooled and filtered oil entering the manifold at port 17 may be internally diverted to the cavity 50 and onto a surface of the particulate screen 52 . The oil will, due to pressure existing in the system and gravity, flow downwardly through the screen to ports 12 and 12 A returning to the engine. Particulate material will collect on the screen 52 and may be periodically removed by accessing the screen by removal of the manifold or through an access panel as described above.
[0026] An oil bleed valve 16 may be provided as seen in FIG. 4 . The oil bleed valve 16 is in a passageway 60 communicating with passageway 34 . A ball 65 is held in place by a spring 66 . The spring 66 is retained by a plug 68 with a small orifice 70 . Passageway 60 is closed by a plug 72 . When the pressure in passageway 34 exceeds a predetermined level, the ball 65 will open returning oil to the engine crank case via line 62 , allowing air within the engine's oil system to be removed.
[0027] FIGS. 2 and 3 illustrate a representative configuration for the manifold and for the configuration of the passageways within the manifold which may be utilized in connection with the cooling system of the present invention. However, it will be appreciated that the particular configuration shape of the manifold may vary with the intended installation. It will also be appreciated that the present system has broad utility and application to various internal combustion engines of different types and displacement. Accordingly, while the present invention has been described in detail with reference to a preferred embodiment it is to be understood that the disclosure has only illustrated an exemplary embodiment.
[0028] FIGS. 5 and 6 are schematics which show a by-pass 100 that may be incorporated into the system 10 shown in FIG. 1 . Referring to FIG. 5 , which 5 shows the by-pass 100 which has a housing 102 having an inlet 106 and outlet 108 connected by a passageway 110 is intercepted by a pressure by-pass line 112 and a temperature by-pass line 114 both of which communicate with by-pass outlet 120 . A pressure control valve 122 such as a spring-biased valve is located in line 112 . The valve 122 may be a direct acting relief valve which opens at a fixed pre-set pressure established by a spring which may be adjusted by a spring adjustment screw. The valve is set to by-pass fluid to the outlet when the differential pressure between the inlet and outlet of the oil cooler is above the setting, typically about 40-50 psi, which differential may initially occur during start-up before the pressure in the system generated by the engine oil pump has fully pressurized the engine oil system.
[0029] Similarly, the temperature by-pass line includes a thermostatic control 126 which has a selected opening temperature generally between 170-200° F. The thermostat control will block flow through the by-pass 100 and direct the oil flow to outlet 120 until such time as the temperature of the oil reaches a temperature at which the thermostat is set to open. Thus, the oil entering the by-pass 100 will be directed to the cold by-pass outlet 120 if either: (1) the engine oil is below a predetermined temperature by the closed thermostat 126 or (2) the oil pressure differential between the inlet and outlet of the oil cooling heat exchanger 15 is greater than the differential setting of the control valve 122 .
[0030] In FIG. 6 , the by-pass 100 is shown in the system 10 of FIG. 1 . The system 10 has been simplified in FIG. 6 but is as described in greater detail with reference to FIG. 1 which description is incorporated here by reference. The by-pass 100 is located adjacent the air-to-liquid heat exchanger 15 , either ahead of the heat exchanger 15 or downstream of the discharge. In FIG. 6 , the by-pass 100 is shown ahead of the heat exchanger 15 . The outlet 108 of the by-pass 100 is in communication with the heat exchanger 15 . The by-pass outlet 120 is connected via by-pass line 130 to line 32 leading to the manifold 11 . Accordingly, if engine oil is below a predetermined temperature or if a predetermined pressure differential exists between the inlet and outlet of oil exceeding the setting of control valve 122 , oil will be by-passed through by-pass 100 allowing the system oil temperature and pressure to build to acceptable levels due to engine operation. This typically may take 4 or 5 seconds after start up. The by-pass 100 lessens stress and wear on engine components due to oil conditions which reduce the effectiveness of the lubrication.
[0031] In FIG. 7 , a modification of the system 10 of Claim 1 is shown which is adopted for engines which operate in colder climates. They system of FIG. 7 is indicated by the numeral 200 and includes a manifold 11 secured to the engine block B as described with reference to FIG. 1 . The hot, unfiltered oil from the engine is directed to a filter 14 by line 20 and exits the filter 14 to tee 202 having outlet lines 232 , 232 A. Line 232 is directed to by-pass 100 located adjacent an air-to-liquid heat exchanger 15 . The by-pass 100 is as described with reference to FIGS. 5 and 6 . The heat exchanger 15 is as has been previously described with reference to FIG. 1 . The by-pass 100 will direct engine oil either to the heat exchanger 15 or, if the temperature or pressure conditions of the oil are within predetermined by-pass parameters, the oil will be by-passed around the heat exchanger 15 via line 130 to line 32 .
[0032] The engine oil discharged through line 232 A is directed to a coolant-to-oil heat exchanger 225 which receives liquid coolant at inlet port 226 from the engine cooling system under pressure from the engine water pump 230 which is recirculated from the heat exchanger via line 234 . The thermostat in the engine cooling system will operate at a preset opening temperature of typically around 190°-200° F. and be circulated by the water pump 230 through the heat exchanger 225 to warm the oil initially flowing through the heat exchanger from the filter. As the engine warms and the engine oil is heated, the heat exchanger 225 will operate to maintain the oil temperature at about the temperature of the engine coolant fluid from the water pump. Thus, the heat exchanger initially assists in heating the engine oil during the initial engine start-up and thereafter will operate to maintain the oil at an acceptable temperature.
[0033] The dual system of FIG. 7 having both an air heat exchanger and a liquid heat exchanger in parallel enhances or increases the effective heat exchange area and operates to cool engine oil during operation and will heat or warm the engine oil during initial start-up and has particular application to engines operating in colder climates or conditions.
[0034] It will be obvious to those skilled in the art to make various changes, alterations and modifications to the invention described herein. To the extent such changes, alterations and modifications do not depart from the spirit and scope of the appended claims, they are intended to be encompassed therein.
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A method of modifying the oil cooling system of a diesel engine includes the steps of removing the original equipment liquid-to-liquid heat exchanger and installing a manifold having a configuration adapted to match the mounting configuration of the oil passages of the original equipment liquid-to-liquid heat exchanger. The manifold has an oil outlet port directed to a remotely mounted oil cooler. The manifold also has a water passage having a configuration that is adapted to match the mounting configuration of the water passages of the original equipment liquid-to-liquid heat exchanger. The water passage causes the entirety of the flow of water to be discharged back to the water cooling system of the engine where it is circulated by the water pump through the water cooling passages in the engine.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 11/845,670, filed Aug. 27, 2007, now abandoned, the entirety of which is incorporated herein by reference.
This application claims priority to U.S. Provisional Application No. 60/840,466, filed on Aug. 28, 2006, the entire disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to high strength surgical suture materials, and more particularly to braided suture blends of ultrahigh molecular weight polyethylene having bioabsorbable coatings.
2. Description of the Related Art
Suture strength is an important consideration in any surgical suture material. One of the strongest materials currently formed into elongated strands is an ultrahigh molecular weight long chain polyethylene, typically used for fishing line and the like, which is sold under the trade names Dyneema or Spectra. This material is much stronger than ordinary surgical suture, however, it does not have acceptable knot tie down characteristics for use in surgical applications.
BRIEF SUMMARY OF THE INVENTION
The present invention advantageously provides a high strength surgical suture material with improved tie down characteristics. The suture features a braided jacket made of ultrahigh molecular weight fibers coated with collagen. The ultrahigh molecular weight polyethylene provides strength. Polyester fibers woven with the high molecular weight polyethylene provide improved tie down properties. Collagen coating is provided to stimulate proliferation and protein synthesis more than standard sutures, and therefore may aid in the tendon-to-bone incorporation process. Moreover, collagen, in addition to providing structural support, can interact with other matrix proteins and cellular receptor affecting cell behavior and gene expression.
There are 19 recognized genetically distinct collagen types and amongst them, the most abundant type is the collagen type I, a heterotrimer. Integrins, a heterodimeric cell surface receptor involved in cell-cell and cell-substrate adhesion, bind the collagen. Typically, four different integrins, for example, α 1 β 1 , α 1 β 1 , α 10 β 1 and α 11 β 1 , are required to bind a collagen. The interactions of integrins with collagen involve a von Willebrand factor A-like domain and require triple helical collagen structures.
Many of the integrins can react with a specific amino acid sequence. Certain integrins appear to bind to only one specific ligand such as a fibronectin receptor, whereas other integrins such as platelet IIb/IIIa and vitronectin receptor can interact with numerous Arg-Gly-Asp (RGD)-containing proteins. Although collagens contain RGD sequences in their primary sequences, the RGD sequences are cryptic and generally inaccessible to cells in the native proteins and therefore, collagens are considered as non-RGD-dependent ligands.
In a preferred embodiment, the suture includes a multifilament jacket formed of ultrahigh molecular weight polyethylene fiber braided with polyester. The jacket surrounds a fiber core made substantially or entirely of ultrahigh molecular weight polyethylene. The core preferably includes three strands of ultrahigh molecular weight polyethylene, twisted at about three to six twists per inch.
The jacket preferably comprises eight strands of ultrahigh molecular weight polyethylene braided with six strands of polyester. Tinted strands can be included in black or some other contrasting color.
Ultrahigh molecular weight polyethylene fibers suitable for use in the present invention are marketed under the Dyneema trademark by Toyo Boseki Kabushiki Kaisha, and are produced in the U.S. by Honeywell under the trademark Spectra.
The suture of the present invention advantageously has the strength of Ethibond No. 5 suture, yet has the diameter, feel and tie-ability of No. 2 suture. As a result, the suture of the present invention is ideal for most orthopedic procedures such as rotator cuff repair, Achilles tendon repair, patellar tendon repair, ACL/PCL reconstruction, hip and shoulder reconstruction procedures, and replacement for suture used in or with suture anchors.
The suture is coated with collagen. Collagen suitable for use in the present invention is marketed under the FIBRACOL trademark by Johnson & Johnson, Medifil® by BioCore, and hyCURE® by The Hymed Group.
A trace thread or two in the suture jacket aids surgeons in identifying the travel direction of the suture during surgery, particularly during operations viewed arthroscopically or remotely. Providing the trace threads in a regularly repeating pattern is particularly useful, allowing the surgeon to decode different ends of a length of suture, and to determine the direction of travel of a moving length of suture. The trace threads preferably are provided uniquely on each half of a length of suture to allow for tracing and identification of each end of the suture, such as when the suture is threaded through an eyelet of a suture anchor.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a copy of a scanning electron micrograph of a length of suture according to the present invention.
FIG. 2 is a schematic cross section of a length of suture according to the present invention.
FIG. 3 is an illustration of the suture of the present invention attached to a suture anchor loaded onto a driver.
FIGS. 4A and 4B show the suture of the present invention attached to a half round, tapered needle.
DETAILED DESCRIPTION OF THE INVENTION
The term “yarn(s),” as used herein, is to be understood as including fiber(s), filament(s), and the like used to make a suture of the present invention. Typically, though, yarns are comprised of fibers and/or filaments.
Referring to FIG. 1 , a scanning electron micrograph of a length of suture 2 according to the present invention is shown. Suture 2 is made up of a jacket 4 and a core 6 surrounded by the jacket 4 . See FIG. 2 . Strands of ultrahigh molecular weight polyethylene (UHMWPE) 8 , such as that sold under the tradenames Spectra and Dyneema, strands of polyester 10 , and tinted strands 12 are braided together to form the jacket 4 . Core 6 is formed of twisted strands of UHMWPE.
UHMWPE, used for strands 8 , is substantially translucent or colorless. The polyester strands 10 are white (undyed). Due to the transparent nature of the UHMWPE, the suture takes on the color of strands 10 and 12 , and thus appears to be white with a trace in the contrasting color.
In accordance with the present invention, trace strands 12 are preferably provided in black. The black trace assists surgeons in distinguishing between suture lengths with the trace and suture lengths without the trace. Traces also assist the surgeon in identifying whether the suture is moving. The trace can extend the entire length of the suture or only on half of a length of suture, the other half of the suture length remaining plain (white). Alternatively, the traces can form visibly distinct coding patterns on each half of the suture length. As a result, when the suture is threaded through the eyelet of a suture anchor, for example, the two legs (halves) of the length of suture are easily distinguished, and their direction of travel will be readily evident when the suture is pulled during surgery.
Details of the present invention will be described further below in connection with the following examples:
EXAMPLE
USP Size 5 (EP size 7)
Made on a 16 carrier Hobourns machine, the yarns used in the braided jacket are Honeywell Spectra 2000, polyester type 712, and nylon. The jacket is formed using eight strands of 144 decitex Spectra per carrier, braided with six strands of 100 decitex polyester, and two strands of tinted nylon. The core is formed of three carriers of 144 decitex Spectra braided at three to six twists per inch. A No. 5 suture is produced.
To make various sizes of the inventive suture, different decitex values and different PPI settings can be used to achieve the required size and strength needed. In addition, smaller sizes may require manufacture on 12 carrier machines, for example. The very smallest sizes can be made without a core. Overall, the suture may range from 5% to 90% ultrahigh molecular weight polymer (preferably at least 40% of the fibers are ultrahigh molecular weight polymer), with the balance formed of polyester and/or nylon. The core preferably comprises 18% or greater of the total amount of filament.
The suture is coated with collagen (FIBRACOL, Medifil), a bioabsorbable material. Collagen is a natural biomaterial that acts as a hemostatic agent. Collagen coating, like all suture coatings, also improves the pliability and handleability of the suture without sacrificing the physical properties of the constituent elements of the suture.
In one embodiment of the present invention, a suture may be coated with native collagen. First, suitable amounts of collagen are dissolved in acetic acid of about 0.1% concentration to derive a stock solution having a final concentration of about 0.5 mg/ml. The stock solution is further diluted with water to a final concentration of about 0.5 mg/ml and the suture is soaked in the stock solution at 4° C. The suture is then dried for at least 1 hour in a laminar flow hood free of dust and debris. About 30 mg of collagen can coat about 200 ft of the suture. A collagen-coated suture may be stored at room temperature for future use.
In yet another embodiment of the present invention, a suture may be coated with denatured collagen. First, suitable amounts of collagen are dissolved in acetic acid of about 0.1% concentration to derive a stock solution having a final concentration of about 0.5 mg/ml. The stock solution is then heated in a water bath at about 50° C. for about 12 hours, later diluted with water to about 0.5 mg/ml and the suture soaked at 4° C. The suture is then dried for at least 1 hour in a laminar flow hood free of dust and debris. About 30 mg of collagen can coat about 200 ft of the suture. A collagen-coated suture may be stored at room temperature for future use.
In an alternative embodiment of the present invention, a partially bioabsorbable suture is provided by blending a high strength material, such as UHMWPE fibers, with a bioabsorbable material, such as PLLA or one of the other peptides, for example. Accordingly, a suture made with about 10% Spectra or Dyneema blended with absorbable fibers would provide greater strength and with less stretch. Over time, 90% or more of the suture would absorb, leaving only a very small remnant of the knot. The absorbable suture can include coatings, for example collagen.
The ultra high molecular weight (UHMW) polymer component of the present invention provides strength, and the polyester component is provided to improve tie ability and tie down characteristics. However, it has been found that the UHMW polymer provides an unexpected advantage of acting as a cushion for the polyester fibers, which are relatively hard and tend to damage each other. The UHMW polymer prevents breakage by reducing damage to the polyester when the suture is subjected to stress.
In one method of using the suture of the present invention, the suture 2 is attached to a suture anchor 14 as shown in FIG. 3 (prepackaged sterile with an inserter 16 ), or is attached at one or both ends to a half round, tapered needle 18 as shown in FIGS. 4 A and 4 B. FIG. 4A also illustrates a length of suture having regularly repeating pattern of trace threads according to the present invention. Sections of the length of suture 2 have tinted tracing threads woven in. The alternating patterned and plain sections aid the surgeon in determining the direction of suture travel when pulling the suture, for example.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art.
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A high strength surgical suture formed of ultrahigh molecular weight polyethylene (UHMWPE) yarns, the suture being coated with native or denatured collagen. The braided jacket surrounds a core formed of twisted yarns of ultrahigh molecular weight polyethylene. The suture has exceptional strength, is ideally suited for most orthopedic procedures, and can be attached to a suture anchor or a curved needle.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/794,602 filed Apr. 25, 2006, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] There are numerous topical pharmaceutical products, which are applied to the skin to treat various conditions. Unfortunately, many of the pharmaceutically active ingredients provided in topical formats can actually penetrate the skin too quickly. This can have a number of potentially adverse consequences. First, the actual degree of exposure of active ingredient and the fungus, bacterial infection or other skin condition in any given skin layer may be too brief. This can require additional dosing, higher dosing frequencies and prolonged treatment. In extreme cases, a particular product could be rendered ineffective.
[0003] Second, when the active ingredient traverses the skin, it may enter the bloodstream where it may be active on unintended vessels and organs. The faster the active material traverses the skin, the greater the amount which reaches the bloodstream unaltered—not having interacted with the intended condition—and hence is available to other systems and organs within the body. Therefore, it would be desirable to provide formulations, which prolong the length of interaction between an active ingredient and the actual layers of skin. Certain fatty alcohol phosphate ester mixtures and their use in topical products are disclosed in U.S. Pat. No. 6,117,915, issued Sep. 12, 2000, to Pereira et al. See also K. F. Gallagher, A New Phosphate Emulsifier for Sunscreens, 113 Cosmetics & Toiletries, 73 (1998).
SUMMARY OF THE INVENTION
[0004] The present invention can provide advantage hitherto unrealized in the field of topical pharmaceutical preparations. By use of the present invention, one can retard the flux (the rate at which a specified amount of a material applied to a specified surface area of skin traverses or travels across the skin in a given period of time) of a topical active pharmaceutically ingredient or “TAPI.” By retarding their transport, i.e., by decreasing their flux across (through the skin—from one side to the other), the active ingredients are provided with more opportunity to interact with the patient's skin condition in the afflicted area. This may permit more efficient, therapeutic relief. In certain embodiments, this may lessen: the length of treatment; the amount of active which must be applied in any one application or in total; the frequency of application; and/or the amount of active which traverses the skin entirely and becomes bioavailable through the circulatory system. Thus, in one embodiment, the present invention provides methods of decreasing the flux of a TAPI across the skin by formulating the TAPI in a topical formulation including mixed fatty alcohol phosphate esters. Methods of increasing skin retention time are also contemplated and include the same steps.
[0005] In another embodiment, the present invention involves a method of improving the “skin retention time” or decreasing the flux of a TAPI in an already known product comprising the steps of adding to that product an effective amount of a fatty alcohol phosphate ester or mixture in accordance with the present invention and forming a homogenous mixture therewith. The improved formulations resulting from that addition are also contemplated.
[0006] Methods of treating humans and animals in need of such treatment by applying to at least one afflicted area of the skin a composition in accordance with the invention that exhibits a decreased flux or increased skin retention time, particularly compared to an otherwise identical formulation not containing mixed fatty alcohol esters of the invention for a time sufficient to provide a biological effect are specifically contemplated. A “biological effect” does not mean that condition is effectively treated, cured or prevented—or even that symptomatic relief is obtained. Moreover, a biological effect may not be observed or measurable for days or even weeks, even with repeated applications of products in accordance with the present invention. A biological effect can be observed on the cellular level, at the level of a layer of skin or in gross and includes any change in biological system that is eventually observable or measurable that results directly or indirectly from the application of the TAPI.
[0007] In another embodiment there are provided new topical formulations containing at least one TAPI and a mixed fatty alcohol phosphate ester in accordance with the present invention. In one preferred embodiment in accordance with this aspect of the invention, these formulations exist as an oil-in-water, water-in-oil or oil-in-oil systems.
[0008] In another embodiment, there are provided formulations containing an amount of mixed fatty alcohol phosphate esters that are sufficient to reduce the flux or increase the surface retention time of the TAPI through the skin, when measured after a period of 24 hours and when compared to the same formulation which omits the fatty alcohol phosphate esters. In a preferred embodiment, these topical formulations reduce the amount of TAPI which traverses the skin after a 24-hour period by 10% or more as measured by counts per minute or CPM or on a weight basis as assayed when compared to the identical formulation without mixed fatty alcohol phosphate esters as described herein. Methods of making these topically active formulations and methods of their use are also contemplated.
[0009] Finally, and in an alternative embodiment, there is provided a method of administering a drug to the blood stream at a predetermined rate comprising the steps of applying a specific amount of a nontopically active pharmaceutical ingredient (“API”) to a predetermined surface area of a patient's skin, preferably a portion of the skin not afflicted with a condition for which the API is being administered to treat, for a time sufficient to allow the desired amount of the nontopically active pharmaceutical ingredient to traverse the skin and enter the blood stream. Formulations including the mixed fatty alcohol phosphate esters or mixtures of the invention along with a nontopically active pharmaceutical ingredient are also contemplated. The products and methods of the invention are suitable for both human and veterinary use and both are contemplated unless otherwise specified.
[0010] In one embodiment, the invention provides a topical pharmaceutical preparation exhibiting decreased flux or increased skin retention comprising: a topical active pharmaceutically ingredient in an amount of at least about 0.1% by weight of the final preparation, about 0.1 to about 20% by weight of mixed fatty alcohol phosphate esters comprising at least one alkoxylated fatty alcohol phosphate ester and at least one non-alkoxylated fatty alcohol phosphate ester present in a ration of 80:20 to 20:80 and a vehicle, said preparation having an improved flux or increased skin retention time of at least about 10%, more preferably about 20% or more, in 24 hours (when measured at about 24 hours) when compared to the same preparation without said mixed fatty alcohol phosphate esters.
[0011] In another embodiment, the invention provides a pharmaceutical preparation exhibiting decreased flux or increased skin retention comprising: a active pharmaceutically ingredient in an amount of at least about 0.1% by weight of the final preparation, about 0.1 to about 20% by weight of mixed fatty alcohol phosphate esters comprising at least one alkoxylated fatty alcohol phosphate ester and at least one non-alkoxylated fatty alcohol phosphate ester present in a ration of 80:20 to 20:80 and a vehicle, said preparation having an improved flux or increased skin retention time of at least about 10%, more preferably about 20% or more, in 24 hours when compared to the same preparation without said mixed fatty alcohol phosphate esters.
[0012] The present invention also provides a method of treating a topical condition in a patient in need thereof by applying to an afflicted area of a patient the composition of claim 1 , maintaining said composition in contact with said afflicted area of said patient, and optionally reapplying said formulation, for a time sufficient to treat said topical condition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 illustrates the reduction in flux of 68% of 3H-cortisol in test skin between two identical formulations with (“CES”) and without (“no CES” or “S-70”) the mixed phosphate esters of the invention at 24 hours.
[0014] FIG. 2 illustrates the reduction in flux as illustrated in FIG. 1 , at 48 hours-57% more 3H-cortisol in/on the test skin.
[0015] FIG. 3 illustrates the systems of FIGS. 1 and 2 at 72 hours—system has rendered equilibrium.
[0016] FIG. 4 illustrates the relative amount of 3H-cortisol in the receptor fluid after 24 hours of two formulations one with and one without a mixed phosphate ester of the invention-91% decrease in CES material in receptor fluid compared to S-70.
[0017] FIG. 5 illustrates the relative reduction of 3H-cortisol in the receptor fluid of the formulations illustrated in FIG. 4 after 48 hours—reduction of 68%.
[0018] FIG. 6 illustrates the relative reduction as in FIGS. 4 and 5 at 72 hours—reduction by 19%.
DETAILED DESCRIPTION
[0019] While the specification concludes with the claims particularly pointing and distinctly claiming the invention, it is believed that the present invention will be better understood from the following description. All percentages and ratios used herein are by weight of the total composition and all measurements made are at 25° C. and normal pressure unless otherwise designated. However, PBS was kept at 37° C., by circulating water bath, so tissue was exposed basally to 37 and apically to RT. The present invention can “comprise” (open ended) or “consist essentially of” the components of the present invention as well as other ingredients or elements described herein. As used herein, “comprising” means the elements recited, or their equivalent in structure or function, plus any other element or elements which are not recited. The terms “having” and “including” are also to be construed as open ended unless the context suggests otherwise. As used herein, “consisting essentially of” means that the invention may include ingredients in addition to those recited in the claim, but only if the additional ingredients do not materially alter the basic and novel characteristics of the claimed invention. Preferably, such additives will not be present at all or only in trace amounts. However, it may be possible to include up to about 10% by weight of materials that could materially alter the basic and novel characteristics of the invention as long as the utility of the compounds (as opposed to the degree of utility) is maintained. All ranges recited herein include the endpoints, including those that recite a range “between” two values. Terms such as “about,” “generally,” “substantially,” and the like are to be construed as modifying a term or value such that it is not an absolute, but does not read on the prior art. Such terms will be defined by the circumstances and the terms that they modify as those terms are understood by those of skill in the art. This includes, at very least, the degree of expected experimental error, technique error and instrument error for a given technique used to measure a value.
[0020] In accordance with the present invention, one objective of certain embodiments is increasing the “skin retention time” of a TAPI. By improving the skin retention time, it is understood that the term encompasses both the amount of time the TAPI is maintained on the outer surface of the skin and/or within any layer thereof. This is evaluated by determining either the amount of TAPI that remains on and/or within skin after 24 hours of exposure using the in vitro testing methodology described herein or by determining the amount of TAPI that has completely traversed the skin and is contained in a receptor fluid using the methodologies described herein including normal analytical assays. Increases in skin retention time, particularly on the outer surface of the skin, can also be observed by skilled medical professionals by simply observing the application area.
[0021] As long as the skin retention time of a topical formulation is improved (e.g., lengthened) when compared to an identical formula not containing mixed fatty alcohol phosphate esters, as described herein, in something more than a negligible way, that is considered improvement. However, in a preferred embodiment in accordance with the present invention, the degree of improvement is at least about 10%, more preferably at least about 20%, more preferably at least about 30% either by CPM or w/w depending upon the system used to measure. These are all based on measurements taken at 24 hours after the test begins.
[0022] Another term used herein, sometimes interchangeably with skin retention time is “flux.” Flux is a measure of the amount of API that traverses or moves across a predetermined area of skin when measured after a period of 24 hours in accordance with the methods described herein when compared to the same formulation, which omits the fatty alcohol phosphate esters or mixtures thereof as described herein. Again, this can be measured directly by measuring the amount of material in the retention fluid after 24 hours and subtracting it from the original amount applied to the skin. In addition, flux can be determined by calculation based on subtraction of the amount of TAPI left in the skin or on the skin subtracted from the amount initially applied and using standard analytical methods. As long as the flux (rate of transport) is lowered for a product in accordance with the present invention when compared to the flux for the product without the mixed fatty alcohol phosphate esters of the present invention, flux has been “improved” in accordance with the invention. Preferably, the amount of improvement is at least about 10% and more preferably about 20%, more preferably at least about 30% either by CPM or w/w depending upon the system used to measure. These are all based on measurements taken at 24 hours after the test begins. That means that the amount of active in the receptor fluid, after 24 hours, is 10, 20, or even 30% less because of the invention.
[0023] Note that in the context of both skin retention time and flux, any technique that provides reliable data can be used as a measure. It is not always practicable to measure the ability of a particular formulation to establish an improvement in either skin retention time or flux by reference to an actual API or TAPI found in a premade formulation. While sometimes the API or TAPI retained in or on the skin can be determined by an assay of the receptor fluid can be measured analytically at 24 hours. A marker or surrogate compound may also be added to a formulation in accordance with the present invention or any formulation that is being evaluated. In that case, the flux or skin retention time of that surrogate compound may be measured instead of or in addition to the actual API or TAPI. As described herein, one such surrogate is a radioactive cortisol known as 3 H cortisol. This may be added to a given formulation and if the formulation tested with and without the mixed fatty alcohol phosphate esters of the present invention are compared, one can evaluate whether or not skin retention time or flux are influenced and indeed improved by the addition of the mixed fatty alcohol phosphate esters. The use of such markers or surrogates is a preferred way to determine flux or skin retention time in accordance herewith.
[0024] Note further that in certain embodiments of the present invention such as those concerned with the actual delivery of an API to the blood stream, skin retention time is not as important as flux. Delaying and/or controlling the delivery of certain active ingredients can be highly desirable. Thus, by reducing the rate of delivery (e.g., flux, the amount of API traversing a defined portion of the skin in 24 hours) one may be able to extend the release of a drug over a period of time that is considered desirable.
[0025] Both topical and systemic embodiments of the present invention can be used alone or in combination with other types of treatment. For example, a topically applied API that provides, in a given formulation in accordance with the invention, a desired flux, may be useful in combination with orally ingested dosage forms to assist in maintaining at least minimum blood level exposures.
[0026] While the invention may be described in terms of patients or subjects, a term which includes people, it will be appreciated that formulations in accordance with the present invention are also highly useful for the topical and systemic administration of APIs and TAPIs for veterinary use, principally in connection with mammals such as dogs, cats, rodents, horses, domestic livestock and the like. Indeed, in one embodiment, the present invention is formulated such that it can be applied to one area of the skin of an animal in treating a veterinary condition and the material will then spread over a much greater portion of the surface area of the animal skin.
[0027] Note also that in this instance, and indeed in other instances as well, the TAPI can be an insecticide such as the material used to retard or fleas and ticks or other insects such as mosquitoes. These are materials, which are not necessarily topically active on their own. Rather they are active in killing or retarding insects. Nonetheless such insecticides are considered TAPIs in accordance with the present invention.
[0028] Similarly, materials which are not necessarily topically active, but can be used for prophylaxis such as antiviral, antifungal or antibacterial agents can be considered TAPIs and can be formulated and applied in accordance with the present invention and used to prevent skin being affected by such external forces.
[0029] It has been discovered that the use of certain fatty alcohol phosphate esters and mixtures or blends can enhance the activity of certain TAPIs, which are intended to be active in at least one layer of the skin. It has been found that these fatty acid phosphate esters are added to various known or novel topical pharmaceutical preparations, preferably those including an oil-phase or oily materials such as oil-in-water emulsions, oil-in-oil systems, water-in-oil emulsions, ointments and the like, the skin retention time can be increased. These mixed fatty alcohol phosphate ester mixtures may be added to currently available topical preparation containing an oil phase or, at least, oily materials, as that term is known in the personal care industry (e.g., fatty acids, fatty alcohols, waxes, mineral oils, silicone oils and the like) or to a non-oily material.
[0030] The use of fatty alcohol phosphate esters in accordance with the present invention is by no means restricted to existing topical pharmaceutical products. Indeed, brand new products can be designed predicated, in whole or in part, on the discovery that these phosphate esters can be used to reduce the rate of transport (reduce flux or increase skin retention time) of a TAPI across the skin. Such new formulations can include, without limitation, new delivery formats for an existing topical product, as well as topical delivery products for a TAPI, which had not previously been formulated in any topically applied product.
[0031] The mixed fatty alcohol phosphate ester useful in accordance with the present invention include, amongst others, those described in U.S. Pat. No. 6,117,915, issued to Pereira et al. on Sep. 12, 2000, and assigned on its face to Croda, Inc., the text of which is hereby incorporated by reference. All are mixtures of at least one alkoxylated and at least one nonalkoxylated fatty alcohol phosphate ester. Indeed, in one embodiment, the fatty alcohol phosphate esters of the invention include a mixture containing between about 10% and about 70% by weight of a blend of mono- and di-ester phosphates of alkoxylated fatty alcohols containing between about 12 and 22 carbon atoms and alkoxylated with between about 1 and about 50 moles of an alkylene oxide consisting of ethylene oxide, wherein the mono- and di-ester ratio is between about 10:90 and about 90:10; and between about 90% and about 30% by weight of a blend of mono- and di-ester phosphates of nonalkoxylated fatty alcohols containing between about 12 and 22 carbon atoms, wherein the mono- and di-ester ratio is between about 10:90 and about 90:10.
[0032] The fatty alcohol phosphate esters useful in accordance with the present invention include a blend of mono- and di-ester phosphates of alkoxylated and non-alkoxylated fatty alcohols containing between 12 and 22 carbon atoms. Preferred fatty alcohols contain between 14 and 20 carbon atoms. Most preferably, a fatty alcohol blend known as cetearyl alcohol is employed, which is a blend of cetyl and stearyl alcohols, which contain 16 and 18 carbon atoms, respectively.
[0033] The phosphate esters of the alkoxylated and non-alkoxylated fatty alcohols of the present invention may be formed by reacting alkoxylated and non-alkoxylated fatty alcohols, respectively, with phosphorous pentoxide (P 2 O 5 ). The alkoxylated fatty alcohols preferably have between about 2 and about 20 moles of the alkoxylating moieties present for each fatty alcohol moiety and are preferably either polyethoxylated, polypropoxylated or both polyethoxylated and polypropoxylated. Therefore, preferred alkoxylated fatty alcohols for use in accordance with the present invention have the structural formula of Formula I:
wherein R is a saturated or unsaturated, substituted or unsubstituted fatty moiety containing from 12 to 22 carbon atoms. X and Y are independently zero or integers from 1 to 50, inclusive, and the sum of X and Y is between 1 and 50, inclusive.
[0034] The non-alkoxylated fatty alcohols suitable for use in accordance with the present invention have the structural formula of Formula II:
R—OH (II)
R is the same as described above with respect to Formula I.
[0035] As is well understood by those of ordinary skill in the art, fatty alcohols [can be derived] are derived from fatty acids, and for this reason, groups such as R are defined as fatty moieties. Fatty alcohols are often commercially prepared from a mixture of fatty acids and contain a mixture of fatty moieties. Therefore, in accordance with the present invention, R may represent a blend of fatty moieties.
[0036] Saturated, unsubstituted fatty moieties containing from 14 to 20 carbon atoms are preferred, and, as noted above, a 16 and 18 carbon atom fatty moiety blend, known as a cetearyl blend, is most preferred.
[0037] The alkoxylated fatty alcohol depicted in Formula I is prepared by the alkoxylation of the fatty alcohol of Formula II. In the above-depicted alkoxylated fatty alcohol of Formula I, X and Y are preferably independently selected from integers from 2 to 20, inclusive, with the sum of X and Y preferably being between 2 and 20, inclusive.
[0038] The alkoxylated fatty alcohols of Formula I are prepared by initially reacting, either sequentially, or in their mixed forms, the fatty alcohols of Formula II with an epoxide, preferably ethylene oxide, propylene oxide, or mixtures thereof, in the presence of an acidic or basic catalyst. It is typical of propylene oxide to branch upon opening of the epoxide ring. Catalysts suitable for this reaction are well-known in the art and include, for example, organic and inorganic alkalies such as alkali metal oxides and hydroxides, e.g., potassium hydroxide, sodium methoxide, sodium borohydride, protic and Lewis acids, e.g., boron trifluoride, stannic chloride and sulfuric acid. Amines, quaternary ammonium compounds, water and other acids may also be employed. Mixtures of catalysts may also be employed. Certain reactive substrates known in the art, for example, acetylenic alkanols may eliminate the need for such catalysts.
[0039] Preferably, a basic catalyst is used in this reaction and most preferably from about 0.1 to about 2.0 weight % of potassium or sodium hydroxide, sodium methoxide, sodium borohydride or mixtures thereof, based on the weight of the fatty alcohol. The reaction is carried out under anhydrous conditions to avoid formation of by-products, and at a temperature, which is preferably in the range of from about 110° C. to about 200° C., although higher temperatures may be utilized.
[0040] The reaction can be carried out at substantially atmospheric pressure, although it is preferably carried out in an autoclave at pressures of from about 10 psig to about 80 psig. The amount of ethylene oxide or propylene oxide introduced to the reaction zone, and the duration of reaction time, determines the numbers of moles of such components added to the fatty alcohol of Formula II, as is well known by those of ordinary skill in the art. In Formula I, X represents the number of moles of ethylene oxide, which are incorporated into each alkoxylated fatty alcohol chain. Likewise, Y represents the number of moles of propylene oxide that are incorporated into the alkoxylated fatty alcohol chain. As will be readily appreciated by those of ordinary skill in the art, stoichiometric quantities of fatty alcohols, ethylene oxide and propylene oxide are reacted together, and stoichiometric quantities of the alkoxylated fatty alcohol and P 2 O 5 are then reacted together to form the mono- and di-phosphate ester alkoxylated fatty alcohol blend.
[0041] For alkoxylation reactions in which the fatty alcohol is both ethoxylated and propoxylated, that is, when neither X nor Y is zero, the alkoxylation reaction is preferably carried out sequentially in that the fatty alcohol is first reacted with the propylene oxide and after complete reaction, the ethylene oxide is introduced into the reaction. After complete reaction of the ethylene oxide, an acid, e.g., phosphoric acid or acetic acid, is introduced into the reaction mixture to neutralize the basic catalyst.
[0042] The fatty acid phosphate ester mixtures of the present invention, in addition to being a blend of alkoxylated and non-alkoxylated fatty alcohol phosphate esters, are also mono- and diester phosphate blends of both the alkoxylated and non-alkoxylated fatty alcohol phosphate esters. Thus, the alkoxylated fatty alcohol of Formula I, prepared as described above, is next reacted in a conventional phosphating reaction with P 2 O 5 to form a mono- and diester phosphate alkoxylated fatty alcohol blend. The fatty alcohol phosphate esters can also be prepared by reacting P 2 O 5 with mixtures of nonalkoxylated fatty alcohols and alkoxylated fatty alcohols.
[0043] The phosphating reaction is typically performed by combining stoichiometric quantities of the alkoxylated fatty alcohol and the P 2 O 5 . As is well understood by those of ordinary skill in the art, the ratio of the two reagents will depend upon the ratio of mono- and diester phosphates desired. To obtain significant quantities of diester in the first place, a stoichiometric excess of P 2 O 5 should be employed, with greater excess levels of P 2 O 5 employed to increase the level of diester obtained. A 1:3 molar ratio of P 2 O 5 to alkoxylated fatty alcohol is preferred.
[0044] The alkoxylated fatty alcohol is heated to a temperature between about 35° C. and about 90° C., and preferably at a temperature between about 50° C. and about 80° C., and then combined with mixing with P 2 O 5 to form a reaction mixture. The alkoxylated fatty alcohol is a liquid at this temperature; therefore, a reaction solvent is not needed. The reaction is then allowed to continue until essentially complete, typically until about 10% or less of unreacted alkoxylated fatty alcohol and trace amounts of unreacted P 2 O 5 , now in the form of phosphoric acid, remain, usually about four hours. The reaction mixture is then recovered as a mono- and diester phosphate blend of alkoxylated fatty alcohols.
[0045] The alkoxylated fatty alcohol phosphate esters are then combined with a mono- and diester phosphate blend of non-alkoxylated fatty alcohols. The phosphate ester blend of non-alkoxylated fatty alcohols is prepared essentially the same as the phosphate ester blend of the alkoxylated fatty alcohols, by reacting stoichiometric quantities of the fatty alcohol of Formula II and P 2 O 5 essentially in the same manner as described above for the alkoxylated fatty alcohol phosphate ester blend.
[0046] As noted above, mixed forms of fatty alcohols containing from 12 to 22 carbon atoms can be employed. Therefore, the resulting phosphate ester blends of alkoxylated and non-alkoxylated fatty alcohols can contain mixtures of alkoxylated and non-alkoxylated fatty alcohol phosphate esters containing from 12 to 22 carbon atoms.
[0047] The phosphate ester compositions of the present invention are then prepared by blending the mono- and di-phosphate ester blends of alkoxylated fatty alcohols with the mono- and diester phosphate blends of non-alkoxylated fatty alcohols. Quantities of the alkoxylated and non-alkoxylated phosphate esters are added to a stirred vessel and heated with mixing at a temperature between about 60° C. and about 90° C., and preferably at a temperature between 75° C. and 85° C., until a uniform homogeneous mixture is obtained, typically about 30 minutes.
[0048] The amount of alkoxylated fatty alcohol phosphate esters blended with non-alkoxylated fatty alcohol phosphate esters will depend upon the ultimate ratio of phosphate esters of alkoxylated and non-alkoxylated fatty alcohols desired. The emulsifier compositions of the present invention contain between about 10% and about 90% of alkoxylated fatty alcohol phosphate esters and between about 90% and about 10% of non-alkoxylated fatty alcohol phosphate esters. Preferred emulsifier compositions contain the ratio of alkoxylated fatty alcohol phosphate esters to non-alkoxylated fatty alcohol phosphate esters between about 20:80 and about 80:20, and more preferably between about 30:70 and about 70:30. The desired ratio is obtained by combining the alkoxylated fatty alcohol phosphate esters and non-alkoxylated fatty alcohol phosphate esters on a weight ratio basis.
[0049] The fatty alcohol phosphate ester mixtures of the present invention may be formulated as emulsifying waxes. Emulsifying waxes are essentially a blend of the emulsifier compositions of the present invention with a fatty alcohol containing from 12 to 22 carbon atoms. Other mixed alkoxylated and nonalkoxylated phosphate esters can be selected from Oleth-5 Phosphate and Dioleyl Phosphate, Oleth-3 Phosphate, DEA Oleth-3 Phosphate, Oleth-10 Phosphate, DEA-Oleth-10 Phosphate. In one embodiment, the mixed phosphate esters, and indeed the other ingredients used in the formulations, are liquid at room temperature. In a particularly preferred embodiment, the final product is one used for veterinary applications where the material is applied to a single place on the animal's skin and it spreads to cover much, if not all, of the animal's skin surface.
[0050] Oil-in-water emulsions typically contain fatty alcohol thickening agents, and fatty alcohol based emulsifying waxes represent a convenient form by which fatty alcohols may be added to oil-in-water emulsions in combination with an appropriate quantity of emulsifier. Thus, the amount of the composition of the present invention combined with a fatty alcohol to form an emulsifying “wax” will depend upon the ratio of fatty alcohol to emulsifier in the oil-in-water emulsion to be prepared. Therefore, emulsifying waxes in accordance with the present invention may contain from about 5% to about 90% by weight of the emulsifier composition of the present invention, although preferred emulsifying waxes will contain up to about 30% by weight of the emulsifier composition of the present invention.
[0051] Preferred emulsifying waxes in accordance with the present invention will be based upon one or more fatty alcohols containing from 14 to 20 carbon atoms. The cetearyl alcohol blend of 16 and 18 carbon atom fatty alcohols is most preferred.
[0052] Oil-in-water emulsions in accordance with the present invention are a preferred form of delivery vehicle for TAPIs and are generally made by combining an oil phase, a water phase and an amount of an emulsifier effective to form an emulsion of the oil and water phase. Likewise, oil-in-water microemulsions in accordance with the present invention combine an oil phase, a water phase and an amount of an emulsifier effective to form a microemulsion of the oil and water phases. The fatty alcohol phosphate ester mixtures may be used as the emulsifier. However, any other emulsifier may be used to build the emulsion, as the primary roles of the fatty alcohol phosphate esters of the invention are believed to be permeation retardation. Any activity as an emulsifier is a bonus, although it is understood that the fatty alcohol phosphate ester mixtures described herein are excellent emulsifiers. Other emulsifiers that may be used include polysorbates and ethoxylated fatty alcohols. Accordingly, no other emulsifier may be necessary.
[0053] Typical emulsions contain an oil phase at a level between about 2% and about 80% by weight, preferably between about 5% and about 60% by weight, and more preferably between about 15% and about 40% by weight; and a water phase at a level between about 10% and about 98% by weight, preferably between about 20% and about 80% by weight, and more preferably between about 40% and about 70% by weight, based on the total emulsion weight.
[0054] For microemulsions, significantly higher levels of emulsifier are often used, so that the oil droplets formed are so small that the emulsion is transparent. Typically, the emulsifier is present at a level greater than or equal to that of the oil phase up to a level of about 300% by weight of the oil phase. A level of between about 150% and about 275% by weight of the oil phase is preferred, with a level of between about 225% and about 250% of the oil phase being more preferred. Such microemulsions typically contain an oil phase at a level of between about 5% and about 80% by weight, and preferably between about 20% and about 40% by weight. The water phase is typically at a level between about 20% and about 95% by weight, preferably between about 30% and about 70% by weight, and most preferably between about 40% and about 60% based on the total weight of the microemulsion.
[0055] The oil-in-water emulsions of the present invention are formulated utilizing techniques that are well-known in the art. Typically, all water-soluble ingredients are mixed together to form the water phase and all water-insoluble ingredients are mixed together to form the oil phase. The two phases are then combined with the emulsifier composition of the present invention and mixed until an emulsion is formed.
[0056] The microemulsion compositions of the present invention are formulated in a similar manner, particularly as described in U.S. patent application Ser. No. 08/052,557, filed Apr. 23, 1993, now abandoned, the disclosure of which is incorporated herein by reference. The emulsifier compositions, the mixed phosphate esters, of the present invention are substituted for the surface active agents described in that application.
[0057] There are many methods for manufacturing products as microemulsions. In one method, all of the ingredients are charged to a reactor and heated, with stirring, until a homogeneous mixture is achieved. Generally, the formulation is heated to between about 80-85° C. and then cooled to about 35° C. or less. During cooling, the microemulsion is established.
[0058] One preferred method of making microemulsions in accordance with the present invention requires the separate and discrete formation of a water phase and an oil phase. In some cases, the water phase may be composed of just water. In other cases, the water phase may include water and the mixed phosphate esters of the invention.
[0059] The oil phase includes at least one oil, preferably mineral oil, and at least one of the mixed phosphate esters of the invention.
[0060] The emulsion and microemulsion based topical preparations of the invention are formulated utilizing techniques that are well-known in the art. Typically, the water-soluble ingredients are dissolved in the water-phase and the water-insoluble ingredients are combined with the oil phase prior to formation of the emulsion. Typically, the ingredients are combined with mixing and the addition of heat if necessary until uniform, homogeneous phases are formed. The two phases are then combined with the addition of the emulsifier composition of the present invention to form an emulsion or microemulsion based topical preparation.
[0061] Those of ordinary skill in the art can readily identify whether a particular active agent is water-soluble or water-insoluble and therefore whether it should be included in the water phase or oil phase of the emulsion. Likewise, whether the topical preparation will be based on an emulsion, microemulsion, ointment or other delivery format is more or less an aesthetic determination based upon whether a milky, opaque product is desired, or whether a clear gel-like microemulsion is preferred. In selecting the microemulsion product form, potential skin irritation from the use of elevated levels of emulsifier and/or surfactant should be considered.
[0062] The topical preparations of the present invention, in addition to including one or more active ingredients (API and/or TAPI) in an oil-in-water, oil-in-oil or water-in-oil emulsion or microemulsion may also include coloring agents, fragrances, proteins, salts, preservatives, essential oils, antiacne agents, and the like. These additional components may be added in various amounts as is well-known in the cosmetic and personal care product formulation art. Such ingredients need not be added prior to the emulsion formation, but may instead be combined with the emulsion with mixing and the addition of heat if necessary until a uniform, homogeneous product is formed.
[0063] While described in terms of oil-in-water emulsion and in mixtures of fatty alcohol ester and emulsified waxes, neither is essential. The fatty alcohol phosphate ester mixtures of the present invention can be added directly to an already existing formulation and need not be mixed with a fatty alcohol based wax or other wax material. In addition, the formulations in accordance with the present invention need not be oil-in-water emulsions. They can be oil-in-oil, water-in-oil emulsions, mixtures and nonemulsified systems and preparations based on at least one oily component as that term is understood in the personal care industry.
[0064] While emulsions and particularly oil-in-oil and oil-in-water emulsions and indeed water-in-oil emulsions are a preferred aspect of the present invention, they are not the only aspect of the invention. Transdermal and topical products and methods as described herein can be accomplished using creams, ointments, gels, pastes and the like, as long as they meet the criteria of the present invention in terms of providing a decrease in flux and/or a concomitant increase in skin retention time. Nonemulsified vehicles which can be used include, without limitation, Triglycerides Oils, e.g. Sesame Oil, Soybean Oil, etc., Ethyl Oleate, Oleic Acid, Cetearyl Ethylhexanoate, Caprylic-Caparic Triglyceride, and PPG-2 Myristyl Ether Propionate. Therefore, products in accordance with the present invention include emulsions as well as creams, ointments, gels, lotions and pastes.
[0065] The total amount of mixed fatty alcohol phosphate esters used in a formulation in accordance with the present invention will vary with the number of factors, including, amongst other things, the remaining ingredients of the formulation, the TAPI or API to be delivered, the degree to which the transport of the TAPI or API across the skin is to be retarded or delayed and the composition of the fatty alcohol phosphate mixture itself. However, at a minimum, the amount used should be an amount sufficient to provide at least some measurable amount of improvement in the flux or skin retention time of some amount of the TAPI or API when compared to an identical formulation without the fatty alcohol phosphate esters. And again, such an improvement in flux or skin retention time may be measured by assay of the actual active or by adding a surrogate or proxy such as 3 H-cortisol and measuring the flux or skin retention time of the surrogate.
[0066] In one embodiment, the total amount of mixed fatty alcohol phosphate esters in accordance with the present invention, based on the total amount of phosphate containing active species, is provided an amount of at least about 0.05% by weight of the total formulation. The upper limit is not critical, however, a point of diminishing returns may be reached. However generally, the amount may range from between about 0.1% to about 20% by weight of the total formulation, more preferably between about 0.5% and about 10% by weight and most preferably between about 0.5% and about 5% by weight of the total formulation.
[0067] One particularly preferred material, which may be used, is sold under the name CRODAFOS CES available from Croda, Inc., 300-A Columbus Circle, Edison, N.J. 08837. CRODAFOS CES is a mixture of cetearyl alcohol and dicetyl phosphate and ceteth-10 phosphate. The amount of phosphate containing fatty alcohol species is roughly 25% with a fatty alcohol wax comprising the other 75% by weight thereof. Therefore, the use of 3% of CRODAFOS CES will provide approximately 0.75 weight percent fatty alcohol phosphate esters based on total weight of the final formulation. Other mixed phosphate esters may be selected from mixtures of, for example, Cetearyl Alcohol and Ceteth-20 Phosphate and Dicetyl Phosphate, Oleth-5 Phosphate and Dioleyl Phosphate, Oleth-3 Phosphate, DEA Oleth-3 Phosphate, Oleth-10 Phosphate, DEA-Oleth-10 Phosphate, PPG-5 Ceteth-10 Phosphate, Cetyl Phosphate and Stearic Acid.
[0068] Any topically active pharmaceutical ingredient (“TAPI”) may, potentially, be delivered in a formulation in accordance with the present invention. Preferably these materials will be active in or on the skin, and on conditions that affect the skin. In the case of water-in-oil emulsions, such TAPIs must also be capable of existing in a system which is both aqueous and nonaqueous without degradation, loss of potency, discoloration or the like.
[0069] Nontopically active pharmaceutical ingredient, also referred to as “APIs,” are pharmaceuticals, drugs or other active materials which are intended to be administered into the blood stream where they exert their influence on the body. Though these APIs are identified as being nontopically active, they may indeed be materials which can exert topical activity. However, the reason for their administration in this instance is not for the treatment of a topical condition. Alternatively, these may be used for the treatment of a topical condition by something other than topical administration. For example, certain steroids may be useful to treat topical conditions. Steroids may also be used to treat other conditions within the body. If the steroids are administered to an area of a patient's skin afflicted by a particular condition, bacterial infection, fungal infection, or the like, for the purposes of treating that condition then the steroid would be considered a TAPI. However, if it were administered through nonafflicted skin, with the intention that the steroid exerts its activity within the body, it would be considered an API.
[0070] Similarly, there are skin conditions, which can affect broad areas of a patient's surface area, which are treated by drugs, which are currently ingested orally. These drugs can now be administered through the skin in accordance with the present invention and, as they are intended to treat a skin condition, they would be considered APIs in the context of the invention, rather than TAPIs.
[0071] Active ingredients, both those to be applied and active in or on the skin, nail, or other topical surfaces (TAPIs) and those which are to be delivered through the skin to the circulatory system (APIs) in accordance with the present invention can be any pharmaceutically active ingredient including, without limitation, abortifacient/interceptive, ace-inhibitor, α-adrenergic agonist, β-adrenergic agonist, α-adrenergic blocker, β-adrenergic blocker, adrenocortical steroid, adrenocortical suppressant, adrenocorticotropic hormone, alcohol deterrent, aldose reductase inhibitor, aldosterone antagonist, 5-alpha reductase inhibitor, anabolic, analeptic, analgesic, androgen, angiotensin converting enzyme inhibitor, angiotensin II receptor antagonist, anorexic, antacid, anthelmintic, antiacne, antiallergic, antialopecia agent, antiamebic, antiandrogen, antianginal, antiarrhythmic, antiarteriosclerotic, antiarthritic/antirheumatic, antiasthmatic, antibacterial, antibacterial adjuncts, antibiotic, anticancer, anticholelithogenic, anticholesteremic, anticholinergic, anticoagulant, anticonvulsant, antidepressant, antidiabetic, antidiarrheal, antidiuretic, antidote, antidyskinetic, antieczematic, antiemetic, antiepileptic, antiestrogen, antifibrotic, antiflatulent, antifungal, antiglaucoma, antigonadotropin, antigout, antihemorrhagic, antihistaminic, antihypercholesterolemic, antihyperlipidemic, antihyperlipoproteinemic, antihyperphosphatemic, antihypertensive, antihyperthyroid, antihypotensive, antihypothyroid, anti-infective, anti-inflammatory, antileprotic, antileukemic, antilipemic, antimalarial, antimanic, antimethemoglobinemic, antimigraine, antimycotic, antinauseant, antineoplastic, antineoplastic adjunct, antineutropenic, antiosteoporotic, antipagetic, antiparkinsonian, antiperistaltic, antipheochromocytoma, antipneumocystis, antiprostatic hypertrophy, antiprotozoal, antipruritic, antipsoriatic, antipsychotic, antipyretic, antirheumatic, antirickettsial, antiseborrheic, antiseptic/disinfectant, antispasmodic, antisyphilitic, antithrombocythemic, antithrombotic, antitubercular, antitumor, antitussive, antiulcerative, antiurolithic, antivenin, antivertigo, antiviral, anxiolytic, aromatase inhibitors, astringent, benzodiazepine antagonist, beta-blocker, bone resorption inhibitor, bradycardic agent, bradykinin antagonist, bronchodilator, calcium channel blocker, calcium regulator, calcium supplement, cancer chemotherapy, capillary protectant, carbonic anhydrase inhibitor, cardiac depressant, cardiotonic, cathartic, CCK antagonist, central stimulant, cerebral vasodilator, chelating agent, cholecystokinin antagonist, cholelitholytic agent, choleretic, cholinergic, cholinesterase inhibitor, cholinesterase reactivator, CNS stimulant, cognition activator, contraceptive, control of intraocular pressure, converting enzyme inhibitor, coronary vasodilator, cytoprotectant, debriding agent, decongestant, depigmentor, dermatitis herpetiformis suppressant, diagnostic aid, digestive aid, diuretic, dopamine receptor agonist, dopamine receptor antagonist, ectoparasiticide, emetic, enkephalinase inhibitor, enzyme, enzyme cofactor, enzyme inducer, estrogen, estrogen antagonist, expectorant, fibrinogen receptor antagonist, gastric and pancreatic secretion stimulant, gastric proton pump inhibitor, gastric secretion inhibitor, gastroprokinetic, glucocorticoid, α-glucosidase inhibitor, gonad-stimulating principle, gout suppressant, growth hormone inhibitor, growth hormone releasing factor, growth stimulant, hematinic, hematopoietic, hemolytic, hemostatic, heparin antagonist, hepatoprotectant, histamine H 1 -receptor antagonist, histamine H 2 -receptor antagonist, HIV proteinase inhibitor, HMG CoA reductase inhibitor, hypnotic, hypocholesteremic, hypolipidemic, hopotensive, immunomodulator, immunosuppressant, intropic agent, insulin sensitizer, ion exchange resin, keratolytic, lactation stimulating hormone, laxative/cathartic, leukotriene antagonist, LH-RH agonist, lipotropic, 5-lipoxygenase inhibitor, lupus erythematosus suppressant, major tranquilizer, matrix metalloproteinase inhibitor, mineralocorticoid, minor tranquilizer, miotic, monoamine oxidase inhibitor, mucolytic, muscle relaxant, mydriatic, narcotic analgesic, narcotic antagonist, nasal decongestant, neuroleptic, neuromuscular blocking agent, neuroprotective, nootropic, nsaid, opioid analgesic, oral contraceptive, ovarian hormone, oxytocic, parasympathomimetic, pediculicide, pepsin inhibitor, peripheral vasodilator, peristaltic stimulant, pigmentation agent, plasma volume expander, potassium channel activator/opener, pressor agent, progestogen, prolactin inhibitor, prostaglandin/prostaglandin analog, protease inhibitor, proton pump inhibitor, pulmonary surfactant, 5α-reductase inhibitor, replenishers/supplements, respiratory stimulant, retroviral protease inhibitor, reverse transcriptase inhibitor, scabicide, sclerosing agent, sedative/hypnotic, serenic, serotonin noradrenaline reuptake inhibitor, serotonin receptor agonist, seratonin receptor antagonist, serotonin uptake inhibitor, skeletal muscle relaxant, somatostatin analog, spasmolytic, stool softener, succinylcholine synergist, sympathomimetic, thrombolytic, thromboxane A 2 -receptor antagonist, thromboxane A 2 -sythetase inhibitor, thyroid hormone, thyroid inhibitor, thyrotropic hormone, tocolytic, topical protectant, topoisomerase I inhibitor, topoisomerase II inhibitor, tranquilizer, ultraviolet screen, uricosuric, vasodilator, vasopressor, vasoprotectant, vitamin/vitamin source, vulnerary, Wilson's disease treatment, xanthine oxidase inhibitor. Preferably, the drug is selected from the group consisting of acyclovir; auranofin; bretylium; cytarabine; doxepin; doxorubicin; hydralazine; ketamine; labetalol; mercaptopurine; methyldopa; nalbuphine; nalozone; pentoxifyll; pyridostigmine; terbutaline; verapamil; buserelin; calcitonin; cyclosporin; oxytocin and heparin. Also encompassed by the terms TAPI and API are the drugs and pharmaceutical active ingredients described in Mantelle U.S. Pat. No. 5,234,957 includes 18 through 21 . The terms Topically Active Pharmaceutical Ingredient(s) and TAPI and Active Pharmaceutical Ingredients(s) and API do not include the actives described in U.S. Pat. No. 6,117,915 which include: UV absorbing agents, aqueous moisturizing agents, oily moisturizing agents, film-forming polymers, thickening agents, secondary emulsifiers other than said mono- and diester phosphates of said alkoxylated and non-alkoxylated fatty alcohols, antiseptic agents, skin conditioning agents, hair conditioning agents, deodorant actives, humectants, rheological modifiers, the above-mentioned protein reducing agents or protein hydrolyzing agents for permanent wave and hair relaxer products, and the like. Some of these, however, may be present in formulations in accordance with the present invention as additional ingredients, additional actives, and/or excipients. For example, topical formulations could include a nonsteroidal anti-inflammatory (“NSAID”) agent as a TAPI and a UV absorbing agent may be present as an additional active.
[0072] Particularly preferred TAPIs and APIs include one or more cyclic or aromatic groups and/or bulky molecules with considerable steric hindrance. These actives include both prescription and over the counter actives, as well as vitamins, collagen, insect repellents, bioflavonoids, as well as products based on squalene, salicylic acid, resouncinol, miconazole, DEET (N,N, diethyl-m-toluamide), tocopherol, tocopherol acetate, retinoic acid, retinol, and retinoids. Examples of suitable anti-acne medicaments include sulfur, erythromycin, zinc, and benzoyl peroxide. Other desirable TAPIs and APIs also include, without limitation, compounds based on perhydrocyclopentanophenanthrene nucleus, the nucleus of steroids, cholesterol and lanosterol, as well as derivatives thereof. Derivatives include, without limitation, androgens such as testosterone and derivatives thereof such as, without limitation, dihydrotesterone, progestational hormones such as progesterone and derivatives thereof, and corticosteroids such as cortisols (hydrocortisones), corticosterone and derivatives thereof. Estrogen based compounds such as beta-Estradiol and derivatives thereof are also desirable. Birth control substances, nicotine and nitroglycerine may also be used.
[0073] In general, the predetermined amount of active ingredient incorporated into each formulation may be selected according to known principles of pharmacy. “Formulation” means an amount of active ingredient and pharmaceutically acceptable excipients combined together which are ultimately incorporated into an overall dosage form. Generally, the amount of active ingredient incorporated is a pharmaceutically effective amount. A “pharmaceutically effective amount” is the amount or quantity of an active ingredient which is sufficient to elicit the required or desired therapeutic response. In other words, it is the amount which is sufficient to elicit an appreciable biological response when administered to a patient. Of course, the amount of active ingredient used can vary greatly. It depends on the size of the dosage, the requirements of other ingredients, the size, age, weight, sex, condition of the patient, their medical condition, and the number of, for example, tablets which constitute a single dose. Typically, an active ingredient in each dose can be present in an amount of from about 0.1 mg to about 1000 mg, preferably from about 1 mg to about 500 mg and more preferably from about 4 mg to about 200 mg. Conventional amounts of pharmaceutically acceptable excipients can be used in this these formulations as well.
[0074] The amount of TAPI or API to be provided in accordance with the present invention will vary with the TAPI or API, the condition of the patient, the length and duration of dosing, the sound judgment of treating professionals, and the Food and Drug Administration or other related regulatory agencies, the solubility or compatibility of the active in the formulation and the like. It will also vary with the condition being treated and whether or not the invention is being used to treat a topical condition or a condition where delivery of the API is through the blood stream. However, generally, formulations in accordance with the present invention will contain at least about 0.1% TAPI or API by weight based on the weight of the total formulation. More preferably, the amount of TAPI or API by weight in the formulation will range from between about 0.1% to about 50%, more preferably from about 0.1% to about 10%, and most preferably from about 0.1% to about 5%. The remainder is excipients, additional ingredients, and/or carriers.
[0075] The compositions of the invention may also include a wide range of miscellaneous ingredients (also known as carriers, excipients, or additional ingredients). Some suitable miscellaneous ingredients commonly used in the cosmetic and personal care industry are described in The CTFA Cosmetic Ingredient Handbook, (2nd Ed., 1992), which is incorporated by reference herein.
[0076] Thus, the compositions of the invention may also include one or more absorbents, anti-acne agents, antiperspirants, anti-caking agents, antifoaming agents, antimicrobial agents, antioxidants, antidandruff agents, astringents, binders, buffers, biological additives, buffering agents, bulking agents, chelating agents, chemical additives, coupling agents, conditioners, colorants, cosmetic astringents, cosmetic biocides, denaturants, drug astringents, detergents, dispersants, external analgesics, film formers, foaming agents, fragrance components, humectants, keratolytics, opacifying agents, pH adjusters, preservatives, propellants, proteins, retinoids, reducing agents, sequestrants, skin bleaching agents, skin-conditioning agents (humectants, miscellaneous, and occlusive), skin soothing agents, skin healing agents, softeners, solubilizing agents, lubricants, penetrants, plasticizers, solvents and co-solvents, salts, essential oils, and vitamins. These may all be present in amounts conventionally used for such ingredients in the topical pharmaceutical, personal care and cosmetics industries, and can range from as little as about 0.01% to about 60% by weight, more preferably from about 0.5% to about 30% by weight. As noted previously, preferred embodiments in accordance with the present invention are provided in the form of an emulsion. Thus, the vehicle used for the mixed fatty alcohol phosphate esters and the TAPI or API is an emulsion. These can include oil-in-water, water-in-oil, and oil-in-oil emulsions. Nonemulsified vehicles including solvents and co-solvents or other carriers may also be used as discussed herein. In particular, topical preparations in accordance with the present invention preferably include an emollient, an emulsifier, a thickener, water, a preservative, a stabilizer, a pH-adjusting substance, a color, a solvent, a co-solvent, a dispersion aide or a solid particulate. The topical pharmaceutical preparations of the present invention can be provided in any known form. However, preferred are creams, milks, lotions, gels, salves, ointments, sprays, mousses, liquids, and sticks. In addition, the topical preparations of the present invention can be applied and then covered with a bandage, or patch, or some other occlusive barrier, or may be provided as part of a pre-made, ready-to-use topical device, such as a bandage, pad, patch or the like. Thus, the material may be applied to a gauze, pad, swab, cotton ball, batting, bandage, patch or occlusive barrier. In one particular embodiment, a preparation in accordance with the present invention can be provided in a well or reservoir or as part of a unitary adhesive or nonadhesive mixture. This material can be sandwiched between a peelable or removable layer and a backing layer, which often forms the reservoir, which is occlusive. While these sorts of patch structures are typically useful for transferal drug applications, they can be used for the topical preparations of the present invention which provide enhanced topical exposure.
[0077] The compositions of the invention may also include one or more emollient compounds such as fats, waxes, lipids, silicones, hydrocarbons, fatty alcohols and a wide variety of solvent materials. The amount of the emollient depends on the application. For the final product compositions, emollients are included in the amount of up to 50% by weight of the composition, preferably, from about 0.1% to about 20%, and more preferably, from about 0.5% to about 10% by weight of the composition.
[0078] Examples of suitable emollients include C 8-30 alkyl esters of C 8-30 carboxylic acids; C 1-6 diol monoesters and diesters of C 8-30 carboxylic acids; monoglycerides, diglycerides, and triglycerides of C 8-30 carboxylic acids, cholesterol esters of C 8-30 carboxylic acids, cholesterol, and hydrocarbons. Examples of these materials include diisopropyl adipate, isopropyl myristate, isopropyl palmitate, ethylhexyl palmitate, isodecyl neopentanoate, C 12-15 alcohols benzoates, diethylhexyl maleate, PPG-14 butyl ether, PPG-2 myristyl ether propionate, cetyl ricinoleate, cholesterol stearate, cholesterol isosterate, cholesterol acetate, jojoba oil, cocoa butter, shea butter, lanolin, lanolin esters, mineral oil, petrolatum, and straight and branched C 16 -C 30 hydrocarbons.
[0079] Also useful are straight and branched chain fatty C 8 -C 30 alcohols, for example, stearyl alcohol, isostearyl alcohol, phenyl alcohol, cetyl alcohol, isocetyl alcohol, and mixtures thereof. Examples of other suitable emollients are disclosed in U.S. Pat. No. 4,919,934; which is incorporated herein by reference in its entirety.
[0080] Other suitable emollients are various alkoxylated ethers, diethers, esters, diesters, and triesters. Examples of suitable alkoxylated ethers include PPG-10 butyl ether, PPG-11 butyl ether, PPG-12 butyl ether, PPG-13 butyl ether, PPG-14 butyl ether, PPG-15 butyl ether, PPG-16 butyl ether, PPG-17 butyl ether, PPG-18 butyl ether, PPG-19 butyl ether, PPG-20 butyl ether, PPG-22 butyl ether, PPG-24 butyl ether, PPG-30 butyl ether, PPG-11 stearyl ether, PPG-15 stearyl ether, PPG-10 oleyl ether, PPG-7 lauryl ether, PPG-30 isocetyl ether, PPG-10 glyceryl ether, PPG-15 glyceryl ether, PPG-10 butyleneglycol ether, PPG-15 butylene glycol ether, PPG-27 glyceryl ether, PPG-30 cetyl ether, PPG-28 cetyl ether, PPG-10 cetyl ether, PPG-10 hexylene glycol ether, PPG-15 hexylene glycol ether, PPG-10 1,2,6-hexanetriol ether, PPG-15 1,2,6-hexanetriol ether, and mixtures thereof.
[0081] Examples of alkoxylated diethers include PPG-10 1,4-butanediol diether, PPG-12 1,4-butanediol diether, PPG-14 1,4-butanediol diether, PPG-2 butanediol diether, PPG-10 1,6-hexanediol diether, PPG-12 1,6-hexanediol diether, PPG-14 hexanediol diether, PPG-20 hexanediol diether, and mixtures thereof. Preferred are those selected from the group consisting of PPG-10 1,4-butanediol diether, PPG-12 1,4-butanediol diether, PPG-10 1,6-hexandiol diether, and PPG-12 hexanediol diether, and mixtures thereof.
[0082] Examples of suitable alkoxylated diesters and triesters are disclosed in U.S. Pat. Nos. 5,382,377, 5,455,025 and 5,597,555, assigned to Croda Inc., and incorporated herein by reference.
[0083] Suitable lipids include C 8 -C 20 alcohol monosorbitan esters, C 8 -C 20 alcohol sorbitan diesters, C 8 -C 20 alcohol sorbitan triesters, C 8 -C 20 alcohol sucrose monoesters, C 8 -C 20 alcohol sucrose diesters, C 8 -C 20 alcohol sucrose triesters, and C 8 -C 20 fatty alcohol esters of C 2 -C 62 -hydroxy acids. Examples of specific suitable lipids are sorbitan diisostearate, sorbitan dioleate, sorbitan distearate, sorbitan isosotearate, sorbitan laurate, sorbitan oleate, sorbitan palmitate, sorbitan sesquioleate, sorbitan esquistearte, sorbitan stearate, sorbitan triiostearte, sorbitan trioleate, orbitan tristeate, sucrose cocoate, sucrodilaurate, sucrose distearate, sucrose laurate, sucrose myristate, sucrose oleate, sucrose palmitate, sucrose ricinoleate, sucrose stearate, sucrose tribehenate, sucrose tristearate, myristyl lactate, stearyl lactate, isostearyl lactate, cetyl lactate, palmityl lactate, cocoyl lactate, and mixtures thereof.
[0084] Other suitable emollients include mineral oil, petrolatum, cholesterol, dimethicone, dimethiconol, stearyl alcohol, cetyl alcohol, behenyl alcohol, diisopropyl adipate, isopropyl myristate, myristyl myristate, cetyl ricinoleate, sorbitan distearate, sorbitan dilaurate, sorbitan stearate, sorbitan laurate, sucrose laurate, sucrose dilaurate, sodium isostearyl lactylate, lauryl pidolate, sorbitan stearate, stearyl alcohol, cetyl alcohol, behenyl alcohol, PPG-14 butyl ether, PPG-15 stearyl ether, and mixtures thereof.
[0085] Emulsifiers
[0086] The compositions of the invention may also include various emulsifiers other than the mixed phosphate esters of the present invention. In the final product compositions of the invention, emulsifiers may be included in the amount of up to about 10%, preferably, in the amount of from about 0.5% to about 5% by weight of the composition. The examples of suitable emulsifiers include stearamidopropyl PG-dimonium chloride phosphate, stearamidopropyl ethyldimonium ethosulfate, stearamidopropyl dimethyl (myristyl acetate) ammonium chloride, stearamidopropyl dimethyl cetearyl ammonium tosylate, stearamidopropyl dimethyl ammonium chloride, stearamidopropyl dimethyl ammonium lactate, polyethyleneglycols, polypropyleneglyocis, and mixtures thereof.
[0087] Thickeners
[0088] The compositions of the invention may also include various thickeners, such as cross-linked acrylates, nonionic polyacrylamides, xanthan gum, guar gum, gellan gum, and the like; polyalkyl siloxanes, polyaryl siloxanes, and aminosilicones. In the final product compositions of the invention, thickeners may be included in the amount of up to about 10%, preferably, in the amount of from about 0.2% to about 5% by weight of the composition.
[0089] Examples of the suitable thickening silicone compounds include polydimethylsiloxane, phenylsilicone, polydiethylsiloxane, and polymethylphenylsiloxane. Some of the suitable silicon compounds are described in European Patent Application EP 95,238 and U.S. Pat. No. 4,185,017, which are incorporated herein by reference. The compositions of the invention may also include silicone polymer materials, which provide both style retention and conditioning benefits to the hair. Such materials are described in U.S. Pat. No. 4,902,499, which is incorporated herein by reference.
[0090] Examples of suitable film formers include glycerin/diethylene glycol myrystate copolymer, glycerin/diethylene glycol adipate copolymer, ethyl ester of PVM/MA copolymer, PVP/dimethiconylacrylate/polycarbamyl/polyglycol ester, and mixtures thereof. If the film formers are present in the final product compositions, the amount may vary from about 0.1% to about 15.0% by weight of the composition, preferably, from about 0.1% to about 2.5% by weight of the composition.
[0091] Methods of Analysis of Skin Penetration
[0092] In one clinical measure of penetration depth is used here only to illustrate the invention, 100 mg of the creams described in Example 1 with or without 2% hydrocortisone were applied to the volar forearm skin for 2 hours uncovered. After 2 hours the volar surface was examined by in vivo confocal laser scanning microscopy using the technique described in in vivo Real-Time Confocal Imaging, J. V. Jester, P. M. Andrews, W. M. Petroll, M. A. Lemp and H. D. Cavanaugh, Jour. Electron Microscopy Techniques, 18:50-60 (1991), in vivo confocal microscopy of human skin: A new design for cosmetology and dermatology, P. Corcuff, G. Gonnord, G. E. Pierard and J. L. Leveque, Scanning: Vol. 18, 351-355 (1996). Images can be collected in real time. 2.1 micron optical sections can be viewed from the top of the stratum corneum to the granulosum ˜14.7 microns depth.
EXAMPLES
Example 1
[0093] For determining flux and/or skin retention time, the following test may be employed. Human skin from breast reduction surgery was used for experimentation. All skin used was deemed intact but not metabolically active. Prior to experimentation the skin integrity was determined by measuring the migration of tritiated water (Bronaugh, et al. 1986). The formulas used contained mineral oil, cetylstearyl alcohol and emulsifying wax NF with and without the fatty acid phosphate ester of the present invention. Specifically, the first formulation included: 5% Polawax, 5% Mineral Oil, 3% CES, and 1% Germaben II. “CES” refers to CRODAFOS CES described herein which is a mixture of cetylstearyl alcohol (2.25% by weight of the final formulation) and a mixture of alkoxylated and nonalkoxylated fatty acid phosphate esters (0.75% by weight of the final formulation). The second formulation is similar and is composed of 5% Polawax, 5% Mineral Oil, 2.25% Crodacol S-70 (cetylstearyl alcohol 70%) and 1% Germaben II with the balance being water. Crodacol S-70 is cetylstearyl alcohol. Thus the only significant difference between the two is whether or not the formulations contain any mixed fatty acid phosphate esters (“CES” or no “CES”).
[0094] Prior to use 11.2 microcuries (uCi) of [1,2,6,7− 3 H] cortisol was added to the prewarmed (37° C.) formulas as noted above, mixed thoroughly, and incubated at 370 C. Split-thickness skin was prepared by dermatoming to an approximate thickness of 0.28 mm. Franz cell finite dosing chambers were used, tissue was placed dermis side down onto phosphate buffered saline (PBS), and 100 microliters of the formulas were placed directly in contact with the stratum corneum. PBS was removed at predetermined times and the radioactivity counted. The lotions were removed and the tissue digested with 50% H 2 O 2 and then counted. Experiments were done in duplicate with each condition tested in triplicate.
[0095] 3 H cortisol was initially applied for 6 hours. There was no migration of the 3 H cortisol into the skin from either formulation. The time was increased to 24 hours.
[0096] After 24 hours there was significantly less radiolabel found in both epidermis ( FIG. 1 ) and the receptor fluid ( FIG. 4 ) of the CES treated skin versus the matched S-70 control. It can be seen in FIG. 1 that the CES restricts the migration of the radiolabeled cortisol to the epidermis by 60% compared to the S-70 control. In FIG. 4 , at 24 hours there was 91% less radiolabel in the CES treated skin receptor fluid as compared to the S-70 formula treated skin. During the next 24 hours ( FIG. 2 , 48H), the migration of the 3 H cortisol into the CES treated epidermis was still significantly less than the S-70 treated skin. The CES restricted the migration by 57% as compared to the S-70 control ( FIG. 2 ). When the receptor fluid data is viewed in FIG. 5 , the amount of 3 H cortisol found was significantly lower in the CES treated skin than the S-70 control by 68%. By 72H there was no significant difference in the amount of 3 H cortisol found in the epidermis of either skin sample ( FIG. 3 ). It appears that the two systems have achieved equilibrium in the split thickness skin. But, in FIG. 6 it appears that CES decreases the 3 H cortisol release from the skin into the receptor fluid by 19% as compared to S-70. Note that this data is not cumulative. Each data set at each time period reflects the discreet differences between the CES containing material and the control at that time point.
[0097] From these data it can be concluded that the inclusion of CES into the formula increases the residence time of 3 H cortisol in the skin. The increased residence time of 3 H cortisol in the epidermis would correlate with less applications of the drug which would increase patient compliance, directed delivery of the drug and lower systemic exposure.
[0098] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
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The present invention relates to methods of influencing the flux or surface retention time of a topically active pharmaceutical ingredient through skin and formulations relating thereto.
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BACKGROUND OF THE INVENTION
This invention relates generally to an improved, light-weight, above-the-ground swimming pool construction which is catastrophic failure-proof owing to the use of a new and improved novel plastic wall material. The new pool requires no internal reinforcement or external support of any kind against the outward pressure of the water contained therein.
Above-ground pools are typically constructed of steel, aluminum or molded thermoplastic material and utilize the same components regardless of the materials. Ordinarily, the components making up the framework for an above-ground pool include rail sections connected to separate base plates; vertical uprights or posts set on the base plates and coping or ledge sections normally connected together over the posts; and, cap members to cover the joints over the posts. A flexible side retaining wall of sheet metal or relatively thick plastic is provided and is held in the rail and by the coping and a liner, normally of flexible vinyl plastic, is supported on the upper edge of the retaining wall. Examples of such prior art pool frames can be found in U.S. Pat. Nos. 3,268,917 Diamond et al 1965; 3,233,251 Barrera 1966; 3,874,132 Mendelow et al 1975; 4,062,158 Kaufmann et al 1977; 4,847,926 Laputka 1989; and 5,054,134 Dallaire et al 1991.
Assembly and joining of the panels is time-consuming, requires tools often not available in households, an important consideration in the erection of small backyard pools. More importantly, earlier pool walls in this type structure have sometimes failed catastrophically and flooded the surrounding area.
SUMMARY OF THE INVENTION
A main object of the invention is to provide an improved, light-weight, above-the-ground swimming pool construction which is free of the above-outlined deficiencies of the prior art, is comparatively easy to assemble and to erect, and is catastrophic failure-proof.
A related object of the invention is to provide a simple, very light, yet solid and long lasting circular swimming pool wall element which can be manufactured at a lower cost than prior art elements fabricated for this purpose. Another important object of this invention is to provide a light-weight, do-it-yourself kit containing the constituent parts of the present pool so as to enable its facile erection by unskilled persons in their backyards and the like.
The objects of the invention may be achieved through the use of a new and improved pool wall material comprising a laminate of woven polypropylene mesh fabric and polypropylene sheets. The new wall material provides a stronger and safer wall than has heretofore been available in this type structure. Advantageously the new wall may be decorated by either printing a design on the mesh before lamination or by weaving a chosen design into the mesh during its fabrication. Existing plastic walls, while fundamentally much safer than metal walls, are relatively heavy and have a tendency (as does metal) to fail catastrophically and to dump water into the surrounding environment like a dam breaking. In accordance with the principles of the invention, the new material, should it fail, will not "burst"; rather, a few strands of fiber mesh may break permitting some water to slowly leak from the pool. In addition, use of the new wall material significantly reduces the weight of an otherwise all solid plastic wall; it reduces manufacturing costs; it reduces shipping costs, and provides many useful options to decorate pool walls through the use of colorful woven mesh designs.
Other advantages to be derived from the practice of this invention will appear from the following description thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view showing an above-ground pool in accordance with the principles of the present invention;
FIG. 2 is an enlarged fragmentary view showing the cross section of the new pool wall with a liner in place;
FIG. 3 is a perspective view of the flat pool wall element before assembly and erection;
FIG. 4 is a perspective view of the wall assembly;
FIG. 5 is an enlarged fragmentary exploded view of the overlapped bolted ends of the pool wall assembly;
FIG. 6 is a fragmentary view of the pool assembly with adhesive tape covering the bolts; and
FIG. 7 is an exploded view of pool fitting hardware.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawing and in particular to FIG. 1, reference character 10 represents the inventive circular, above-the-ground pool which is delimited by an upstanding vertical peripheral wall set up on the ground (preferably over a flat sand support surface) to form a cylindrical tank or shell 12. As is conventional in this type of pool, the pool shell 12 is lined with a water-retaining flexible liner 14 of polyvinyl chloride in the shape of a right cylinder.
A flexible U-shaped plastic coping 16 is used to secure the liner 14 to the upper edges of the shell wall 12 after it is draped in the shell. Thus after erection of the wall 12, as will be described hereinbelow, the liner 14 is draped within the periphery of the cylindrical pool wall 12 to establish a water-retaining structure.
In accordance with the invention and as shown in FIG. 2, the new wall 12 is formed of a core of continuous length of semi-rigid, flexible high-melt strength polypropylene plastic 18 to which a woven mesh polypropylene fabric sheet structure 20 is laminated, preferably autogenously under heat and pressure. The sheet structure 20 is advantageously woven having a density of about 3 ounces per yard, a mesh of 24×11, and containing a UV inhibitor.
More specifically, the characteristics of a preferred mesh reinforcement sheet 20 are:
______________________________________Typical Properties Test Method______________________________________Material PolypropyleneColor NaturalConstruction ASTM D-3775 24 × 11Weight, oz/yd ASTM D-3776-C 3.0Tensile Strength ASTM D-1682-GEwarp, lbs. 150fill, lbs. 80Burst Strength, PSI ASTM D-3786 275UV Resistance: ASTM D-4355 N/AStrength Retention______________________________________
The characteristics of a preferred base polypropylene core are:
______________________________________Typical Resin Properties High-Melt-Strength Polypropylene______________________________________Melt flow rate, dg/min 0.4Density, g/cm.sup.3 0.902Notched Izod impact strength 3.0 (161)at 23° C. ft-lbs/in. (J/m)Tensile strength at yield, psi (MPa) 5,400 (37)Elongation at yield, % 12Flexural modulus, psi (MPa) 240,000 (1,650)Rockwell hardness, R Scale 96Deflection temperature at 19466 psi (455 k Pa), °F. (°C.)Water absorption after 24 hrs. % 0.02Environmental stress-cracking, hrs. >1,000Coefficient of linear thermalexpansion, cm/cm/°C.-30 to 0° C. 7.1 × 10.sup.-50 to 30° C. 9.7 × 10.sup.-530 to 60° C. 11.0 × 10.sup.-5______________________________________
The cylindrical wall or shell 12 of the pool of FIG. 1 is formed from a 38 ft. by 3 ft. rectangular sheet 30 (FIG. 3) having a series of assembly holes 31, 32 formed at its opposite side edges. The sheet 30 is folded so that the ends overlap and the holes 31, 32 register (FIG. 4). A series of bolts 36 inserted through each of the registered holes (FIG. 5) and secured by nuts 37 to establish a collapsed, closed sidewall loop 12 which is then set up as a cylindrical side wall 12 (FIG. 1). This provides an approximately 12 ft. diameter pool which will hold approximately 2,500 gallons. The length of the wall 12 can be increased to 47 ft. to provide a 15 ft. diameter pool holding approximately 3,900 gallons or to 57 ft. to provide an 18 ft. diameter pool holding approximately 5,700 gallons.
The wall 12 is provided with an intake opening 33 associated with which are circulating fittings including a leaf strainer 44, intake fitting 45, gasket 46, and locking ring 47. Advantageously a protective strip of adhesive tape (duct tape) 48 is superimposed on the nuts and bolts to cover any rough edges.
The intake fitting 45 is passed through a hole (not shown) formed in the liner 14 in registry with the intake hole 33 in the pool wall 12.
As common in above-ground, lined pools, the pool water is circulated by a circulating pump-filter 40 having an inlet hose line 41 extending from the intake fitting 35 to the pump and having a return hose line 42 extending back into the pool as shown.
An inverted-U shaped ladder 43 may be included as part of a pool kit for facilitating entry and egress from the pool.
The commercial attractions of the inventive pool are: the provision of a stronger, safer wall wherein the failure of a few strands of woven material will allow small amounts of pool water to escape without catastrophically bursting and flooding the area; the provision of a lighter product since reinforcing the polypropylene wall with polypropylene fabric allows a reduction of about 30% of the pool weight as compared with solid prior art walls; the reduction in the cost of production of pools; and the increase in the facility with which the pool wall may be decorated.
The pool of the invention has been thoroughly tested under actual use conditions and has been found to be completely successful for the accomplishment of the above-stated objects of the present invention.
It is understood that persons skilled in the art to which this invention is directed will be able to obtain a clear understanding of the invention after considering the foregoing description in connection with the accompanying drawing.
Although the foregoing description has been given by way of one preferred embodiment, it will be understood by those skilled in the art that other forms of the invention falling within the ambit of the following claims is contemplated. Accordingly, reference should be made to the following claims in determining the full scope of the invention.
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An above-the-ground pool construction having a catastrophic failure-proof wall of comparatively low weight which is fabricated from a laminate of polypropylene and a woven polypropylene mesh reinforcement. The new wall is stronger and safer than existing walls; it is lighter weight; and it provides ease of pool wall decoration through the use of woven designs in the reinforcing mesh or by printing the mesh before it is laminated.
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This invention was funded in part by a grant from the National Institute of Health under contract number NOl-HV-88106.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a device and method for providing pumping support to an artificial ventricle or heart. More particularly, the present invention pertains to a hydraulic pumping system used in connection with an artificial ventricle which relies on transfer of hydraulic fluid between a pumping chamber associated with the ventricle and a volume displacement chamber which is separated from the pumping chamber and associated ventricle.
2. Prior Art
Current trends in research in the general field of ventricle assist devices and artificial hearts is placing greater emphasis on electrohydraulic drive systems instead of air-driven mechanisms which require use of a driveline through the skin. The advantages of an electrohydraulic heart are numerous. The total unit is implantable and self-contained. In contrast, pneumatic drive systems are cumbersome and impose serious constraints in view of the transcutaneous driveline and potential for infection.
An early design for an electrohydraulic drive system is set forth in U.S. Pat. No. 4,173,796 by Jarvik. It discloses the use of an axial impeller assembly with an electric drive motor, referred to hereafter as a "fluid pump and drive motor". Hydraulic fluid is moved by action of the impeller assembly as it rotates about its axis. By reversing the electric motor, the hydraulic fluid can be reversibly pumped, thereby filling and extracting the fluid with respect to a pumping chamber associated with the ventricle.
When used within a total artificial heart, the fluid pump and drive motor can simple be reversed to transfer fluid from a first pumping chamber associated with a left ventricle, to a second pumping chamber associated with the right ventricle. The difference in cardiac output between the left and right ventricles can be balanced by use of an intra-atrial shunt, a leaking pulmonary artery valve or a small extra compliance reservoir.
In situations where the pumping fluid is not alternately driving a blood pumping chamber, a volume displacement chamber is used to store this pumping fluid. For example, during diastole in a single ventricle assist device, pumping fluid is removed from the pumping chamber associated with the ventricle through a conduit, and is stored in a bag or other volume displacement chamber. This transfer is accomplished with the same type of reversible fluid pump and drive motor as is disclosed in the Jarvik patent. During systole, the motor reverses and forces the fluid from the displacement chamber to the pumping chamber with the ventricle.
Prior practice in positioning the fluid pump and drive motor has followed the pattern set by the Jarvik patent. Specifically, this device is placed in the intermediate flow line or interconnect between the pumping chamber and the volume displacement chamber. This is a logical position because the fluid must pass through the impeller assembly of the pump, which naturally becomes part of the flow path. Accordingly, prior art practice has consistently positioned the fluid pump and drive motor as a continuous part of the interconnect device, or as a continuous part of the interconnect flow path. As such, hydraulic fluid contact has been limited to the interior flow channel within the fluid pump. The exterior surface of the fluid pump and drive motor have been treated much like a tubular enclosure in that this exterior structure functioned to contain the fluid within the flow path. Therefore, any contact of hydraulic fluid with the exterior of the interconnect and associated fluid pump was contrary to reasonable design considerations.
The use of an electrohydraulic drive system involves other mechanical considerations which are not associated with a pneumatic drive system. For example, because the system is self-contained within the patient, dependability and durability are critical. Both of these factors are affected by the minimization of wear on components of the drive motor. Accordingly, a variety of techniques have been applied to design drive motors with a minimal amount of friction, as well as other mechanical factors that cause abrasive wear and generate attendant heat.
Although advanced technology has provided much improved motor design, there remains the challenge of dissipating heat generated with the drive motor. It will be apparent to those skilled in the art that electrohydraulic drive systems depend on conversion of electric power to hydraulic power. Such conversions will always generate some heat as a by product. When such heat is confined and accumulated within the small volume of a pumping system in support of a ventricle, some detrimental effect is inevitable. In prior art systems where the drive motor and impellers are further confined within a tubular interconnect, dissipation of heat is even more difficult. Without effective heat control, increased wear occurs and the inevitable failure of the system is accelerated.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide improved means for dissipating heat within a ventricle assist device utilizing an electrohydraulic drive system.
A further object of the present invention is to provide improved efficiency in a fluid delivery system to an artificial ventricle pumping membrane.
A still further object of this invention is to provide an improved electrohydraulic drive system which requires less space within the ventricle assist device, thereby facilitating emplacement within a patient and simplifying surgical procedures.
These and other objects are realized in a ventricle assist device for placement within a living body which includes a self contained drive motor for generating pumping action with respect to a hydraulic pumping fluid being reversibly transferred to and from a pumping chamber for effecting blood transfer. This device is comprised of a ventricle housing and an internal pumping membrane which divides the ventricle into a blood chamber and a pumping chamber. The blood chamber includes inlet and outlet means for enabling unidirectional blood flow to and from the ventricle. A separate volume displacement chamber having sufficient fluid volume to receive the pumping fluid from the pumping chamber is attached to the ventricle by means of interconnect means which define a fluid flow channel therebetween. A fluid pump and drive motor is positioned at the interconnect means and is substantially within the volume of the displacement chamber such that a substantial exterior portion of the pump and drive motor is contacted by the hydraulic pumping fluid contained therein. This device can also be structured with respect to a clamshell pumping mechanism in which the clamshell provides a ventricle support housing and an internal pumping membrane which forms an exposed flexible pumping diaphragm which is powered by the fluid pump and drive motor. Here again, the fluid pump and drive motor are positioned within a separate volume displacement chamber wherein a substantial exterior portion of the pump and drive motor is contacted by the hydraulic fluid within the displacement chamber.
Other objects and features of the present invention will be apparent to those skilled in the art in view of the following detailed description, in combination with the accompanying drawings.
DESCRIPTION OF DRAWINGS
FIG. 1 is a elevated perspective view of a ventricle assist device constructed in accordance with the present invention.
FIG. 2 is a graphic representation of a cross-section taken along the lines 2--2 in FIG. 1.
FIG. 3 shows a schematic representation of an additional embodiment of the inventive ventricle assist device.
FIG. 4 is a cross-section taken along the lines 4--4 of FIG. 3.
FIG. 5 is a schematic representation of a further embodiment of the present invention wherein two ventricle assist devices are coupled to a single volume displacement chamber.
FIG. 6 is a cross-section taken along the lines 6--6 of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 illustrate a ventricular assist device comprising a ventricle which consists of a ventricle housing 11 which encloses a blood chamber and includes inlet 12 and outlet 13 for enabling unidirectional blood flow 15 to and from the ventricle 10. The base 16 of the ventricle comprises a flexible membrane which cooperates with a pumping membrane 17 to alternately extend and collapse in accordance with conventional practice. The embodiment illustrated in FIG. 1 is generally characterized as a clamshell structure because the ventricle 10 is structured as a soft polymer, compliant blood sack. The more rigid pumping structure is supplied by the shell portion of the ventricle assist device which consists of a more rigid structure 18 formed as a concave support (see FIG. 2). The flexible pumping diaphragm 17 is sealed at the periphery 19 of the rigid shell and provides the pumping force required by extending (shown in phantom line) and collapsing 20 in a reciprocating manner.
In practice, the soft ventricle 10 is first sutured in place within the patient and tested for operational integrity to ensure that there are no leaks in the system and to verify that the ventricle is operational. At that point, the shell portion 18 and pumping support system are added by nesting the soft ventricle 10 within the concave shell 18. A stiff interlock perimeter 21 which extends around the soft ventricle 10 seats within a retaining ring 22 as illustrated in FIG. 2. In this configuration, the contacting membrane 16 of the blood chamber reciprocates inward and outward in response to corresponding movement of the pumping membrane 17. The components of the ventricle 10 and clamshell 18 are made by vacuum forming polyurethane and by radio frequency welding perimeters to develop the required structures. Ventricle sizes depend on the needs of a patient, but are typically in the range of 60 to 100 cc.
It is apparent in this configuration that a separate volume displacement chamber 25 is required to receive the pumping fluid during diastole, when the pumping membrane 17 is retracted to its collapsed position 20. This separate volume displacement chamber 25 must have sufficient fluid volume to receive the pumping fluid from the pumping chamber 26 when the blood chamber 27 is in diastole and the pumping chamber is at its minimal volume (as illustrated in FIG. 2). The illustrated volume displacement chamber 25 is configured as a disc with opposing first 28 and second 29 exterior faces of convex configuration when fluid volume is full. One of these convex faces 28 comprises rigid material for maintaining the disc configuration and for providing support to a fluid pump and drive motor (referred to collectively as 30) which may be secured 31 to the rigid face 28. This rigid face or back plate 28 was formed of a thick sheet of polyurethane of about 0.180 inches. It is also possible to fabricate the volume displacement chamber 25 with a soft back 28 inasmuch as maintenance of any particular disc configuration is not essential to operation of the system.
The opposing face of the volume displacement chamber 25 comprises a flexible member 29 which is capable of readily collapsing in response to evacuation of a substantial portion of the fluid into the pumping chamber 26. This desired compliance can be embodied with a sheet fabricated of polyurethane and appropriately sealed at the disc perimeter 33. This perimeter 33 is also provided with an access port 45 which facilitates initial filling of the volume displacement chamber with hydraulic fluid, as well as making adjustment in fluid volume at a later time.
The pumping chamber 26 and volume displacement chamber 25 are coupled together by an interconnect means 40 which defines a fluid flow channel 41 enabling delivery of pumping fluid between the displacement chamber 25 and the pumping chamber 26. The configuration and length of the interconnect means 40 is selected to permit placement of the ventricle 10 and pumping chamber 26 in proximity to the patient's cardiac cavity, with the volume displacement chamber 25 being disposed in the thorax or abdomen. Specifically, the volume displacement chamber is configured to fit against the human rib cage in the dorsal part of the phrenicocostal sinus. The neck is made flexible 43 to facilitate positioning of the volume displacement chamber 25 within the patient.
The primary feature of the present invention involves the placement of the fluid pump and drive motor 30 within the volume displacement chamber 25, rather than within the interconnect means 40. The fluid path 41 through the interconnect is maintained into the fluid pump and drive motor 30 by attachment of the proximal end 44 of the fluid pump at the interconnect means 45, with the distal end 46 being positioned within the displacement chamber for providing reversible pumping action to transfer hydraulic fluid through the interconnect means and between the displacement chamber and the pumping chamber. The fluid pump and drive motor is positioned substantially within the volume displacement chamber such that a substantial exterior portion 47 of the fluid pump and drive motor is contacted by hydraulic fluid contained within the volume displacement chamber.
The illustrated fluid pump and drive motor comprises an axial flow pump in which the exterior portion 47 is fabricated of heat transfer material which enhances thermal transfer of energy from the drive motor 48 into the hydraulic fluid contained within the volume displacement chamber. For preferred efficiency, at least one half of the exterior portion of the fluid pump and drive motor 30 should be contained within the volume displacement chamber and in contact with the hydraulic fluid. A vacuum formed ring 49 comprised of polyurethane keeps the motor in place at its point of attachment to the interconnect means. A strain relief flap 50 is provided adjacent to the distal end of the fluid pump and drive motor to protect the compliance membrane 29 from folding over the distal end 46 of the fluid pump. This ensures that this membrane is not sucked into the fluid pump as hydraulic fluid is being returned to the pumping chamber 26.
The size of the drive motor 30 is configured to be slightly smaller than an inner diameter of the tubular interconnect 40 to facilitate sealing at the vacuum formed ring 49. Power supply wires 51 leave the volume displacement chamber through a small tube which has a side tube connected to it, proximal to where it is sealed to the electric plug. The free end 52 of the side tube can be occluded with a plug and buried under the skin so that it can be retrieved if necessary. This tube can also be used to fill and de-air the volume displacement chamber, as well as change the hydraulic fluid volume after implantation of the device. It is also possible to take pressure recordings from the volume displacement chamber at the end of this tube 52. The wire tube leaves the skin using a skin button as is well known in this field of art, particularly with the use of pneumatic drive lines. The system can be made completely implantable by the use of transcutaneous energy transfer systems, which are currently under development.
It will be apparent to those skilled in the art that the preferred embodiment set forth in FIGS. 1 and 2 is merely an exemplary of the inventive emplacement of positioning the fluid pump and drive motor within the volume displacement chamber. In addition, additional embodiments are illustrated in FIGS. 3 through 6.
FIG. 3 illustrates the use of a coupling element 60 within the interconnect line 61. This facilitates attachment and detachment of the volume displacement chamber 62 without the need of concurrently removing the ventricle 63. This figure also illustrates the use of a crows foot indentation 64 wherein the rigid material comprising one of the convex faces of the disc members includes a channel indentation 64 projecting away from the volume displacement chamber (see FIG. 4) to provide fluid flow paths for the hydraulic fluid as the compliant face 66 seats toward the rigid convex face 65. The fluid pump and electric motor 67 is illustrated at its central position within this volume displacement chamber 62.
FIGS. 5 and 6 illustrate the use of a single volume displacement chamber for servicing two separate ventricles 70 and 71. In this case, the volume displacement chamber 72 includes separate fluid pumps and drive motors 73 and 74. Although less chamber volume is available, the alternating fill and extraction cycles of the respective motors 73 and 74 provide adequate hydraulic fluid to maintain pumping operations. Operational aspects of both embodiments shown in FIGS. 3 and 5 are in accordance with previous discussion.
In all instances, the present invention provides several significant advantages over the prior art. First, by placement of the energy convertors or drive motors within the volume displacement chamber, more effective cooling of the energy convertors is provided. Heat is conducted away from the energy convertor into the volume displacement chamber or into the pumping chamber, where further heat dissipation is accomplished into the patient's body. Secondly, the placement of the energy converter within the volume displacement chamber reduces the size requirements for the total system. This facilitates compactness of the device and ease of emplacement within the patient. Both of these benefits have been verified in actual test situations within test animals. Sizing and placement considerations have been verified in cadavers. The invention appears to have immediate utility with respect to ventricle assist devices which are in constant demand. As the demand for permanent ventricle assist devices develops, the inventive ventricle assist device disclosed herein will be of even greater value, in view of its greater capacity to dissipate heat and survive extended use.
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A ventricle assist device for placement within a living body and including a self contained drive motor for generating pumping action with respect to a hydraulic pumping fluid. The ventricle assist device includes a ventricle having a blood chamber and a pumping chamber and an interconnect means coupled to the pumping chamber of the ventricle for receiving and displacing hydraulic fluid. A separate volume displacement chamber is attached to the interconnect means and provides a reservoir for excess hydraulic fluid for storage during diastole. A fluid pump and drive motor is positioned within the volume displacement chamber and connected at the interconnect means to supply the required pumping action for transfer of hydraulic fluid to and from the pumping chamber. Placement of the fluid pump and drive motor within the volume displacement chamber provides enhanced dissipation of heat from the energy conversion system and improved performance and durability.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to planetary gearing, clutches and brakes for an automatic transmission used in motor vehicles. The invention pertains, more particularly, to a transaxle having two planetary gear units that produce two overdrive speeds, direct drive, and two underdrive speeds.
2. Description of the Prior Art
Various arrangements of clutches, brakes and one-way clutches are used in the prior art to control operation of dual interconnected planetary gear units to produce forward speed ratios and a reverse drive ratio in an automatic transmission.
U.S. Pat. No. 4,418,585 has clutches and brakes arranged so that a gear ratio change from the lowest speed to the second speed is made nonsynchronously, i.e., by transferring torque from an overrunning coupling to a friction clutch. In that transmission, a gear shift from the second speed to the third speed requires disengagement of the brake band and application of a clutch. A gear ratio change from the third speed to the fourth or overdrive speed also requires disengagement of a brake band and engagement of a friction clutch. In the operation of the transmission, none of the gear shifts require synchronous disengagement of a clutch and engagement of another clutch. Therefore, timing problems in the engagement and release of the clutch brake control servos are eliminated.
The transmission according to the '585 patent requires time for disengagement of a high speed ratio clutch and application of a friction brake in order to produce the ratio change from the third forward speed to the fourth overdrive speed.
U.S. Pat. No. 4,368,649 describes a four-speed transaxle that overcomes this difficulty. In the transaxle of the '649 patent the gear shift from the third speed to the fourth speed results by applying a single friction brake in addition to the other friction elements engaged during the third speed ratio. A gear shift from the first speed to the second forward speed results merely by engaging a second friction clutch while a companion friction clutch remains applied. In this way, a ratio change from the first ratio and from the third ratio in the forward driving speed range results merely by engaging or disengaging a single friction element, either a clutch or a brake, thereby greatly simplifying control of the clutches and eliminating potential for harsh or abrupt gear shift changes.
U.S. Pat. No. 4,509,389 describes a further improvement that eliminates a latent difficulty in control of the transmission of the '649 patent that makes calibration of the two-three upshift difficult. The sun gear is not connected to a friction clutch cylinder but is connected instead to the inner race of an associated one-way clutch. The inner races of each one-way coupling are connected to a common member, which operates as a torque delivery element for the input sun gear of the planetary gear. The maximum speed of the friction clutch cylinders is equal to the speed of the driven sprocket of a chain mechanism connecting the output of a torque converter to the input shaft of the transmission.
U.S. Pat. No. 4,086,827 describes a four speed transmission in which a single one-way clutch is located in series between an input friction clutch and a gear member of a planetary gear set. The one-way clutch permits the gear member to overrun the input during an overdrive ratio so that an upshift from the third speed to the fourth speed results without a synchronous release of the input friction clutch. To produce a downshift from the fourth speed to the second or third speeds, the input increases to the speed of the gear member by engagement of the one-way clutch when a friction brake or another friction clutch is released.
The present invention provides for five forward speeds and a reverse drive ratio, and is an improvement over the four speed transaxle described in U.S. Ser. No. 739,641 filed Aug. 2, 1991, assigned to the assignee of this invention.
SUMMARY OF THE INVENTION
My invention is a two-axis transaxle having a hydrokinetic torque converter mounted on an axis concentric with the engine crankshaft and parallel to the axis of the multiple speed gearing. The transaxle produces two underspeed ratios, a direct drive ratio, two overspeed ratios and a reverse drive ratio.
The automatic transaxle of this invention produces five forward speed ranges and a reverse drive. Because of the unique arrangement of the clutch, brakes and one-way couplings, the transaxle is extremely compact and its weight is low. The compactness of the transaxle is the result of use of certain components of the transaxle for multiple purposes to produce multiple speed ratios. For example, the structure that provides the gearset reaction force through a one-way coupling in intermediate speed ranges, the second and third speed ratios, is used also to transmit torque converter turbine torque in the reverse drive condition.
The torsional path between the engine and the planetary gear in the reverse drive condition is through a reverse friction clutch and a cylinder or drum that provides a surface engaged by an intermediate brake band and the friction plate of the reverse friction clutch. This use of the shell or drum for multiple purposes eliminates the need for an additional component.
A one-way coupling, located between the gear units and engine, overruns in the reverse coast condition. The engine is driveably disconnected from the wheels and therefore unavailable to impede vehicle movement. This avoids abrupt unexpected changes in acceleration when the operator changes from drive to coast conditions in the reverse range.
The transmission includes three planetary gear units each including a sun gear, a ring gear, a carrier and planetary pinions rotatably supported on the carrier and meshing with the sun gear and ring gear. The carrier of the first gear unit is fixed to the ring gear of the second gear unit and is driveably connected as the output from the gearing to the sun gear of a final drive planetary gearset that drives a differential mechanism.
The carrier of the second gear unit is connected to the ring gear of the first gear unit and to the inner race of a one-way brake fixed to the transmission casing. The sun gears of the second and third gear units are connected mutually and to two one-way couplings, each coupling fixed to a respective brake. The carrier of the third gear unit is releasably connected to a brake.
Parallel torque delivery paths between the ring gear of the first planetary gear unit and a low reverse brake drum comprise a one-way coupling and a forward clutch in parallel with a coast clutch, which provides a torque reaction that bypasses the one-way clutch during a coast condition.
The clutches and brakes of the transaxle are arranged so that the gear ratio change from the lowest speed to the second speed results by transferring torque from a one-way brake to a intermediate brake band. A gear ratio change from the second speed to the third speed results when a direct clutch is engaged and while the brake band continues to be applied. A gear ratio change from the third speed to the fourth speed results by applying an overdrive brake, a friction member, while maintaining engagement of the direct clutch. An upshift to fifth speed from fourth speed result by engaging a fifth speed brake while maintaining engaged the friction elements that produce fourth speed. Therefore, no ratio change requires synchronous disengagement of a friction element and application of another friction element. Because of this feature, timing problems in the engagement and release of friction clutches and brakes and control servos are eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-4 in combination comprise a cross section taken along the axes of the input and output shaft showing various friction clutches and brakes, and several one-way couplings used to produce multiple forward speeds and reverse drive.
FIG. 5 is a schematic diagram showing planetary gearing, clutches, brakes, couplings, torque converter, chain drive mechanism, final gearing and a differential mechanism.
FIG. 6 is a chart that shows a schedule of engagement and disengagement of clutches, couplings and brakes and to establish the forward drive ratios and reverse drive of the transaxle of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIGS. 1-5, a hydrokinetic torque converter 10 is driveably connected to an internal combustion engine having a crankshaft 12 connected to a bladed impeller 14 of the torque converter. A bladed turbine 16, a bladed stator 18, and the impeller 14 define a toroidal fluid flow circuit within the casing of the torque converter. The stator 18 is supported on a stationary sleeve shaft 20, and a overrunning brake 22 anchors the stator to shaft 20 to prevent rotation of stator 18 in a direction opposite to the direction of rotation of the impeller, although free-wheeling motion in the opposite direction is permitted.
Turbine 16 is connected to turbine sleeve shaft 24, which drives the torque input sprocket wheel 26. Sprocket wheel 26 is part of an input torque transfer drive that includes also drive chain 28 and driven sprocket wheel 30, which is mounted for rotation about the torque input sleeve shaft 32. Axle shafts 34, 36 are concentric with the axis of input shaft 32.
Planetary gearing includes three simple planetary gear units. The first gear unit includes a sun gear 36, ring gear 38, carrier 40 and planetary pinions 42, supported by carrier 40 in meshing engagement with sun gear 36 and ring gear 38. The second planetary gear unit includes a sun gear 44, a ring gear 46, carrier 48 and planet pinions 50, supported by carrier 48 in meshing engagement with sun gear 44 and ring gear 46. The third gear unit includes a sun gear 52, a ring gear 54, a carrier 56 and planet pinions 58, supported by carrier 56 in meshing engagement with sun gear 52 and ring gear 54. Carrier 48 and ring gear 54 are connected mutually, and they are connected to ring gear 38 by a drum 60, forward clutch 62 and a one-way coupling 64, also identified as OWC2. Ring gear 46 is connected to carrier 40 and to torque output shaft 66. Sun gears 44, 52 are connected mutually by shaft 68.
A final drive planetary gearset 70 is located in a torque delivery path between output shaft 66 and a differential gear unit 72, to which axle shafts 34 and 36 are connected. Gear unit 70 includes sun gear 74, connected to output shaft 66; ring gear 76, permanently fixed to the transmission casing; a carrier 78, connected to the spindle 80 of the differential mechanism 72; and planet pinions 82, rotatably supported on carrier 78 in engagement with sun gear 74 and ring gear 76. Differential gear unit 72 has bevel pinions 84, 85, which mesh with bevel side gears 86, 87, connected respectively to axle shafts 34, 36.
Sprocket wheel 30, connected to sleeve shaft 32, is connected directly to sun gear 36 of the first planetary gear unit. Sun gears 44, 52 of the second and third gear units are releasably connectable to the transmission casing through a one-way coupling 92 (OWC3) and a brake 88, which carries also the symbol 4B. Sun gears 44, 52 are releasably connected to the casing also through one-way coupling 94 (OWC4) and by a brake 90, which also carries the symbol 2B. The inner races of one-way couplings 92, 94 are directly connected by sleeve shaft 68 to sun gears 44, 52; the outer races of couplings 94, 92 are connected respectively to the drum 96, which is connected, to the transmission casing through operation of brake 90 and to brake 88.
The outer torsional member of reverse clutch 98 (RC) is connected to drum 96, and the inner member of the reverse clutch is directly connected to input shaft 32 and to the outer member of direct clutch 100 (DC). Carrier 48 of the second gear unit is selectively connected to input shaft 32 through direct clutch 100.
The torque converter includes a lockup clutch 102, located within the torque converter and impeller housing. The torque output side of the lockup clutch has a damper 104 located between the impeller and the turbine sleeve shaft 24 so that engagement of the lockup clutch will not be accompanied by harshness due to transitional torque fluctuations.
The inner race of a one-way or overrunning brake (OWC1) 106 is directly connected to carrier 48 and drum 60; the outer race of brake 106 is fixed permanently against rotation to the transmission casing. The inner race of one-way clutch 64 is connected to ring gear 38, and its outer race is connected to one element of forward clutch 62. One-way couplings 64, 92, 94 and one-way brake 106 are roller-type overrunning couplings generally having an outer cam with an inclined surface driveably connected to, and released from the inner race by a roller in accordance with the speed of rotation ,of the inner race relative to the outer race. Brake 110 (5B), a friction disc brake, holds carrier 56 against rotation by connecting it to the casing when the brake is engaged and releases carrier 56 when disengaged.
The inner race of one-way coupling 64 is also connected to an element of coast clutch 108 (CC), the other component of the coast clutch being connected to drum 60.
Friction elements 62, 88, 98, 100, 108, 110 are hydraulically actuated clutches and brakes of the type having multiple friction discs supported rotatably on one member of the friction element and a second set of friction discs interposed between the members of the first friction disc set and supported rotatably on the other member of the friction element. When hydraulic pressure is applied to the friction element, the discs are brought into mutual frictional contact and the friction element transmits torque between its members. When the magnitude of hydraulic pressure supplied to the friction elements is reduced, a spring disengages the discs and the friction element is thereafter unable to transmit torque.
A low/reverse brake band 112 selectively engages drum 60 in low speed manual and reverse drive conditions. Brake bands 90, 112 are actuated by hydraulic servos, which contract the corresponding brake band into engagement with the respective drums 60, 96 and release this engagement when the corresponding servo is vented
FIG. 6 shows a chart indicating the clutches and brakes that are engaged and released selectively to produce each of the various forward drive ratios and the reverse ratio. In the chart, the symbol X is used to identify an engaged clutch or brake, the symbol O/R is used to designate an overrunning condition for couplings or brakes 52, 84, 96, and a blank is used with respect to columns entitled "OWC1", "OWC2" and "OWC3" and "OWC4" to indicate a one-way coupling or brake that is neither overrunning nor driving.
In operation with the gear selector in the "D" or "OD" position, to establish automatically the lowest forward speed ratio, forward clutch 62 is applied, one-way clutch 64 drives, and one-way brake 106 drives. When the forward clutch is engaged, ring gear 38 is fixed to the transmission casing against rotation, thereby providing the gearset reaction. Engine torque then is transmitted hydrodynamically through the torque converter, and transfer drive chain 28 to sprocket wheel 30, input shaft 32, and sun gear 36. Carrier 40 of the first planetary gear unit drives output shaft 66, and the axle shafts 34, 36 are driven through final drive gear set 70 and differential unit 72. When operating in the D-range under a coast condition, one-way brake 106 and one-way clutch 64 overrun.
When first gear is selected manually by the operator by placing the gear shift lever in the 1M-range position, coast clutch 108 and low reverse band 112 are applied. The torque delivery path from ring gear 38 through the coast clutch shunts the torque path that includes one-way coupling 64 and forward clutch 62. Therefore, in the drive condition, there are two parallel paths potentially providing a gearset reaction on the transmission casing to hold ring gear 38 against rotation. One path is through one-way coupling 64 and forward clutch 62, and one-way brake 106; the other path is through coast clutch 108 and reverse band 102. However, in the coast condition, couplings 64 and 106 are inoperative, and the reaction on the transmission casing that holds ring gear 38 is provided through the coast clutch and the low/reverse band.
The torque delivery path for the second forward speed in the D-range results when forward clutch 62 and brake band 90 are applied, one-way couplings 64, 94 drive, and one-way brake 106 overruns. In this instance, sun gear 44 is held against rotation on the transmission casing by engagement of brake band 90. Torque from the engine is delivered to sun gear 36 and the output is taken at carrier 40, which is connected to output shaft 66. In the coast condition, all one-way couplings 64, 84 106 overrun; therefore, the output means comprising output shaft 66, carrier 40 and planet pinions 42 turn as a unit.
When the gear selector is set manually for operation in the 2M-range, coast clutch 108, forward clutch 62, friction brake 88 and brake band 90 are applied. During the drive condition in the 2M-range, one-way couplings 64, 94 drive and one-way brake 106 overruns. In this instance, sun gear 44 is fixed against rotation on the transmission housing by engagement of the brake band 90, and ring gear 38 is driveably connected to carrier 48 of the second planetary gear unit through either the torque delivery path that includes coast clutch 108 or the parallel path that includes one-way coupling 64 and forward clutch 62. In the coast condition in the 2M-range, one-way brake 106 overruns and one-way couplings 64 and 94 are inoperative. Sun gear 44 is fixed to the transmission casing against rotation by brake 88. Ring gear 38 is connected to carrier 48 of the first planetary gear unit through the path that includes coast clutch 108 and drum 60. Sun gear 36 drives input shaft 32.
When the transmission operates in the third forward speed and the gear selector is in the D-range, where gearshifts are produced automatically, forward clutch 62 and brake band 90 remain engaged, direct clutch 100 is engaged and one-way coupling 62 drives. Torque input from the engine is directed through the direct clutch and intermediate shaft 102, arranged concentrically with input shaft 32 and axle shaft 34, to carrier 48 of the second planetary gear unit. Carrier 48 drives ring gear 36 through drum 60, forward clutch 62 and one-way coupling 64. The torque output is taken by carrier 40 to output shaft 66.
During a coast condition in the third forward speed of the D-range, one-way couplings 64, 94, 106 overrun and torque from output shaft 66 is transmitted through carrier 48 to ring gear 46, which is driveably connected by overrunning coupling 64 to input shaft 32.
With the transmission operating in the 3M-range forward clutch 62, coast clutch 108, direct clutch 100 and brake band 90 are applied. During a drive condition in that range, one-way coupling 64 drives. With the friction elements so engaged, the engine shaft 12 is driveably connected through the torque converter and chain drive to the input shaft 32, which is connected through direct clutch 100 to intermediate shaft 114, which drives carrier 48, the input member of the second planetary gear unit. Carrier 48 is connected through forward clutch 62 and one-way clutch 64 to ring gear 38. The third speed ratio is a direct drive ratio; therefore, the output unit, ring gear 46, carrier 40 and output shaft 66, turn at the speed of carrier 48 and ring gear 38. During a coast condition in the 3M-range, one-way couplings 94, 106 overrun, and couplings 64, 92 are inoperative. Therefore, coast clutch 108 and drum 60 bypass the torque delivery path that includes forward clutch 62 and one-way coupling 64 to driveably connect ring gear 38 to carrier 48, thereby driving input shaft 32 at the speed of output shaft 66. Engagement of brake 82 assures that one-way coupling 94 overruns.
The fourth forward speed, an overdrive ratio, is available when the gear selector is in the D-range and 4M-range positions. To produce the fourth speed ratio in the D-range, brake band 88, forward clutch 62 and direct clutch 100 are applied, one-way coupling 64 and 106 overrun, one-way coupling 94 is inoperative and coupling 92 drives. Consequently, the engine shaft is connected through the torque converter, chain drive mechanism, input shaft 32, direct clutch 100 and intermediate shaft 114 to carrier 48, the input to the planetary gearing. Sun gear 44 is fixed against rotation on the transmission housing by engagement of friction brake 88. The output is ring gear 46, carrier 40 and output shaft 66, whose speed of rotation is multiplied through this arrangement in the second planetary gear unit only. The first gear unit is inoperative, although forward clutch 62 is engaged, because one-way coupling 64 overruns. Engagement of brake band 90 assures that one-way coupling 94 overruns in the drive condition.
During the fourth speed coast condition in the D-range, one-way couplings 64, 92, 106 overrun. Sun gear 44 is held against rotation by brake 88, and shaft 66 drives carrier 40 and ring gear 46. Carrier 48 is driveably connected to the sprocket wheel 30 of the chain drive mechanism through intermediate shaft 114, direct clutch 100 and input shaft 32.
During operation in the 4M-range, brake 88, direct clutch 100, and forward clutch 62 are engaged. Couplings 64, 106 overrun but coupling 92 drives. Consequently, under drive conditions, sun gear 44 produces the gearset reaction because it is held on the casing through coupling 92 by engagement of brake 88. Carrier 48 is driven, but because coupling 64 overruns,the output is taken at ring gear 46, carrier 40 and shaft 62.
Under coast conditions in the 4M-range, shaft 66 drives carrier 40 and ring gear 46, but sun gear 44 is held against rotation by brake 88. Consequently carrier 48 drives intermediate shaft 114, which is connected to the engine through shaft 32, the direct clutch, and the chain drive mechanism.
The fifth speed is available only with the gear selector in the D-range. Fifth speed results when brakes 88 and 90, the direct clutch, and forward clutch are engaged. This causes couplings 64, 92, 106 to overrun and holds carrier 56 against rotation. Input shaft 66 drives carrier 48 and ring gear 54 through the direct clutch and intermediate shaft. Planet pinions 58 counterdrive sun gear 52 and drum 56 through coupling 94 because carrier 58 held. Torque carried by compound sun gears 52 and 44 combine in the second gear unit to drive planet pinions 58, which also revolve due to the connection of carrier 48 to the input shaft. Ring gear 46, which is driven by carrier 48 and pinions 58, is connected to the output shaft by carrier 40. Ring gear 38 and the inner race of coupling 64 overrun.
When the transmission is disposed for reverse drive operation, input shaft 32 is driveably connected through reverse clutch 98, drum 96, one-way coupling 94 and sleeve shaft 68 to compound sun gears 52 and 44, the input to the second planetary gear unit. Carrier 48 is fixed against rotation through engagement of low/reverse brake band 112. As a result of this engagement, ring gear 46 is counterrotated and the output is taken on carrier 40 and output shaft 66. During the coast condition in the R-range, coupling 94 overruns, thereby driveably disconnecting sun gears 44 and 52 from input shaft 32 and from the engine.
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A transaxle for use in an automotive vehicle driveline includes a torque converter and a compound planetary gear system having three simple planetary gear units adapted to provide five forward driving torque delivery paths, the two highest speed ratios being overdrive, the axis of the torque converter being located on the crankshaft axis of the vehicle engine, and a torque output shaft being parallel to the torque converter and engine axis. Hydraulically actuated friction clutches and brakes and one-way couplings interconnect the input and output of the transmission to members of the planetary gearing and the transmission casing. A final drive planetary gearset, driven by the output of the planetary gear units, drives a differential mechanism connected to the axle shaft of the vehicle.
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BACKGROUND
1. Field of Invention
This invention relates to firearms, in particular to the buffering of the impact of movable parts placed into motion by the firing of the firearm that would be normally transmitted to the frame of the firearm when the movement is terminated.
2. Description of Prior Art
Many firearms have moveable parts that move in response to the firing of the firearm, a process commonly called recoil. The rearward movement of these parts is terminated by their slamming into the frame of the firearm. Such pounding reduces the accuracy of the firearm and can reduce the service life of the component parts through deformation or breakage. The shock of the pounding from firing is fatiguing to the shooter and will lengthen the amount of time necessary to realign the sights before accurately firing subsequent shots.
Recent introduction of more powerful ammunition has increased the problem, resulting in the overstressing of firearms that were originally designed for less powerful ammunition. Recent trends of arming the police with more powerful firearms has resulted in the issuing of firearms beyond the recoil tolerance levels of many police officers.
Prior art such as U.S. Pat. No. 3,756,121 to Roy (1973), U.S. Pat. No. 3,901,125 to Raville (1975), U.S. Pat. No. 4,522,107 to Woodcock et al. (1985) and U.S. Pat. No. 4,754,689 to Grehl (1988) employed the use of a buffer mechanism installed between the rear of the recoil spring and the frame that would be entrapped between the frame and a part moving to the rear upon firing. Such a mechanism is clearly inapplicable for firearm designs wherein the rear of the recoil spring is seated in a well in the frame below the surface of the frame impacted by the moving part. As a result an entire type of firearm design that features a recoil spring the rear of which is seated in a well in the frame cannot be protected from impact by these means.
U.S. Pat. No. 2,522,192 to Porter (1950) employs a spring-loaded plunger that protrudes from the front of the recoil spring guide that contacts the moving part at a point in the center of the front of the recoil spring. Such a mechanism is clearly inapplicable for firearm designs wherein the recoil spring guide extends through the moving part past the surf-ace contacted by the front of the recoil spring. As a result an entire type of firearm design that features a recoil spring guide that extends forward of the front of the recoil spring cannot be protected from impact by this means.
OBJECTS AND ADVANTAGES
The principal object of the invention is to buffer the impact of moving parts set into motion by the firing of a firearm, a process commonly called recoil, that would normally be transmitted to the frame of the firearm when their movement is terminated.
In particular the invention permits the installation of a buffering mechanism in firearm designs where the rear of the recoil spring or springs are seated in a well in the frame of the firearm to the rear of the surface upon which the moving parts collide in the termination of their movement.
Another object of the invention is to provide a mechanism that may be adapted to a wide variety of firearms.
Another object of the invention is to provide a mechanism that may be easily retrofitted to a variety of existing firearms without the need for a skilled gunsmith.
Another object of the invention is to provide a mechanism that would not denigrate from the handling of the firearm when the mechanism is operated manually for the loading or unloading of ammunition.
It is a further object of the invention to produce a mechanism that would not add appreciably to the maintenance of the firearm and that would have a long service life.
Other objects will be in part obvious and in part pointed out in more detail later.
A better understanding of the objects, advantages, features, properties and relationships of the invention will be obtained from the following detailed description and accompanying drawings which set forth certain illustrative embodiments and is indicative of the way in which the principal of the invention is employed.
SUMMARY OF THE INVENTION
A impact-buffering recoil mechanism for firearms includes a buffer (3) (4) moveably mounted on a guiding member (1) (17) between a plurality of coil springs (2) (5). the mechanism is positioned sin the firearm so that the moveable buffer travels from a position of repose to interpose between moveable parts (7) of the firearm (16) set into motion by the firing of the firearm and the frame of the firearm (8). this interposing will bring the moveable parts to an orderly halt while dissipating impact energy that would normally be transmitted to the frame and hence to the shooter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross-sectional side view of a conventional firearm, parts in repose, ready to fire with the impact buffering recoil mechanism in place.
FIG. 2 is a partial cross-sectional side view of a conventional firearm with a moveable slide in movement from firing with the impact buffering recoil mechanism in place.
FIG. 3 is a partial cross-sectional side view of a conventional firearm with a moveable slide at the final stage of movement from firing with the impact buffering recoil mechanism in place.
FIG. 4 is a cross-sectional side view of an alternative embodiment of the invention.
FIG. 5 is a graph showing the relationship between the pressure on a moveable slide during movement and its position during movement.
FIG. 6 is an exploded side view of a typical embodiment of the invention.
REFERENCE NUMERALS IN DRAWINGS
1. end stop
2. buffer spring
3. end plates
4. belleville disc springs
5. slide spring
6. slide spring guide
7. moveable slide
8. frame
9. barrel
10. slide tunnel (A location)
11. rear surface of the slide spring guide (A location)
12. slide tunnel face (A location)
13. frame shoulder (A location)
14. spring well (A location)
15. trigger
16. firearm
17. assembly guide
18. sliding member
19. retaining means
DESCRIPTION OF THE INVENTION
A typical embodiment of the present invention is illustrated in FIG. 6.
An end stop 1 is a cylindrical part having a radially enlarged head at the rear and a body that serves as a guide for a buffer spring 2, end plates 3 and belleville disc springs 4 at the front. The preferred material for the end stop is hardened steel to resist wear. The forward end of the body attaches to a slide spring guide 6 during assembly of the mechanism.
The buffer spring 2 is a coil spring selected to have a compressed solid length shorter than the depth of a spring well 14 FIG. 1-3 minus the height of the end stop head as well as to provide specific pressures at points B and C of FIG. 5.
The end plates 3 are washers of tempered steel to provide surfaces for the bellevilles 4 to flex against during compression. The end plates also provide support for the bellevilles in cases where the design of the firearm 16 FIG. 1-3 has part of a frame shoulder 13 FIG. 1-3 and/or a slide tunnel face 12 FIG. 1-3 removed.
Belleville disc springs 4 are common commercial components selected to stop the movable parts in recoil without compressing flat. In some applications it has been found advantageous to mix sizes of bellevilles to prevent a shock wave from being transmitted through them from the a moveable slide 7 to a frame 8 FIG. 1-3.
The belleville disc springs 4 and end plates 3 collectively compose the moveable buffer of the typical embodiment of the impact buffering recoil mechanism.
A slide spring 5 is a coil spring selected to have a solid compressed length shorter than the depth of a slide tunnel 10 FIG. 1-3 and to provide specific pressures at points A and B FIG. 5.
Slide spring guide 6 is a cylindrical part having a diameter greater than that of the body of the end stop 1. A rear surface of the slide spring guide 11 forms a shoulder Where it abuts to the front of the end stop 1 to entrap the buffer spring 2, end plates 3 and bellevilles 4 so that the entire mechanism minus slide spring 5 can be handled as a unit.
The slide spring 5 being separate can be interchanged with other springs of various powers to accommodate ammunition of different levels of power.
BEST MODE FOR CARRYING OUT THE INVENTION
A conventional firearm 16 as illustrated in FIG. 1-3 includes a frame 8 to which a barrel 9 and a moveable slide 7 are mounted. Between the frame 8 and a moveable slide 7 an impact buffering recoil mechanism with end stop 1, buffer spring 2, end plates 3 and belleville disc springs 4, slide spring 5 and slide spring guide 6 are mounted. FIG. 1 illustrates the relationship of the parts in a position of repose, ready for the depressing of a trigger 15 to fire the firearm.
Upon the firing of the firearm the slide will reactively travel to the rear compressing the less powerful slide spring 5 and to a lesser degree the more powerful buffer spring 2. This movement will correspond to section A to B FIG. 5. Note the modest increase in pressure placed on the slide.
FIG. 2 corresponds to section B to C FIG. 5. The slide spring 5 has been compressed to the maximum amount permitted by its position in a slide tunnel 10. The end plates 3 and bellevilles 4, which collectively compose the moveable buffer of the invention, are being pushed to the rear by a slide tunnel face 12 compressing the buffer spring 2 against the head of the end stop 1. The compressing of the more powerful buffer spring 2 results in a greater increase in spring pressure between points B and C FIG. 5.
FIG. 3 illustrates the firearm with the slide at the end of its rearward movement. This corresponds to section C to E FIG. 5. The slide spring 5 has been compressed to the maximum amount permitted by its position in a spring well 14. The bellevilles 4 are now being compressed between the end plates 3 which are in turn entrapped between a frame shoulder 13 and the slide tunnel turn entrapped between a frame shoulder 13 and the slide tunnel face 12. The rearward movement of the slide 7 will terminate at point D FIG. 5, at a point short of E FIG. 5 where the bellevilles 4 would have been compressed flat. This will result in all of the slide energy being depleted short of the slide tunnel face 12 slamming into the frame shoulder 13.
The sequential compression of the slide spring 5, buffer spring 2 and the belleville disc springs 4 result in the "L" shaped pressure curve in FIG. 5. The advantage of this curve rather than a straight line from A to D is that it permits the slide 7 to establish a momentum level sufficient for the reliable functioning of the firearm 16 and permits the firearm to be more readily functioned by hand in the loading and unloading of ammunition. The ease of manually functioning the firearm is a distinct safety advantage since the pressure required to manually operate the slide 7 from point A to B is a close duplication of the original stock spring of the firearm.
A slide spring guide 6 is of larger size than the body of the end stop 1 so that the mechanism can be handled as a unit with the buffer spring 2, end plates 3 and bellevilles 4 being entrapped between the head of the end stop 1 and a rear surface of the recoil spring guide 11. This feature will avoid presenting the shooter with a multitude of small and easily lost parts during disassembly of the firearm for maintenance. The slide spring 5 is easily exchanged during disassembly for one of a different power to accommodate ammunition of differing levels of power.
FIG. 4 illustrates an alternative embodiment of the invention wherein the end stop 1 and the recoil spring guide 6 are replaced by a single assembly guide 17 which entraps the buffer spring 2, end plates 3, bellevilles 4 and slide spring 5 between an radially enlarged head at the rear and a sliding member 18 at the front held on the assembly guide 17 by a retaining means 19. As illustrated in FIG. 4 the buffer spring 2 and slide spring 5 are partially compressed. When installed in the firearm 16 the sliding member 18 is pushed slightly to the rear by the bottom of the slide tunnel 10 relieving pressure from the retaining means 19 and applying it to the slide 7. The functioning of the alternative embodiment is the same as for the invention.
A resilient sheet of an energy-dissipating material may be substituted for the belleville disc springs 4 in the moveable buffer.
One or both of the end plates 3 in the movable buffer may be unnecessary for some applications of the invention.
As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosures can be made without departing from the teaching of the invention.
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A impact-buffering recoil mechanism for firearms includes a buffer (3)(4) moveably mounted on a guiding member (1)(17) between a plurality of coil springs (2)(5). The mechanism is positioned in the firearm so that the moveable buffer travels from a position of repose to interpose between moveable parts (7) of the firearm (16) set into motion by the firing of the firearm and the frame of the firearm (8). This interposing will bring the moveable parts to an orderly halt while dissipating impact energy that would normally be transmitted to the frame and hence to the shooter.
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BACKGROUND OF INVENTION
[0001] This invention relates to floating brush seal assemblies. Specifically, this invention relates to axial brush seal assemblies that can float in the axial direction within a gap between two components.
[0002] Gas turbine engines that exhibit high axial and radial growth transients between adjacent components during operation typically use a labyrinth seal between the components to control leakage. A labyrinth seal comprises a plurality of teeth extending from a disk on one of the components and a honeycomb pad on the other component. The teeth and the pad cooperate to form a serpentine leakage path between the components. The serpentine path inhibits fluid flow between the components.
[0003] However, labyrinth seals have several drawbacks. First, the rigid teeth of the labyrinth seal cannot accommodate a “zero clearance” condition without incurring permanent wear or damage to the teeth. This wear increases the leakage rate of the seal. Second, the leakage rate of the labyrinth seals increases with the increased clearance between the teeth and the pad.
SUMMARY OF INVENTION
[0004] It is an object of the present invention to provide an improved seal.
[0005] It is a further object of the present invention to use a brush seal to control leakage between adjacent components that exhibit high axial and radial growth transients during operation.
[0006] It is a further object of the present invention to provide a seal that can accommodate tight “zero clearance” conditions without permanent wear or damage.
[0007] It is a further object of the present invention to provide a compliant seal that can accommodate a wide range of clearances.
[0008] It is a further object of the present invention to provide a seal that maintains a relatively constant leakage flow rate even as the clearance between the components increases.
[0009] These and other objects of the present invention are achieved in one aspect by a brush seal assembly for sealing a gap between a first component and a second component. The assembly comprises: a body; bristles extending from the body; and an extension from the body, the extension having an elongated slot therein. The slot, when the brush seal assembly mounts between the first and second components, allows the brush seal assembly to float within the gap.
[0010] These and other objects of the present invention are achieved in another aspect by an axial brush seal assembly for sealing a gap between a first component and a second component. The brush seal assembly comprises: a body; bristles extending from said body; and means for allowing movement of the brush seal assembly in an axial direction within the gap.
[0011] These and other objects of the present invention are achieved in another aspect by an apparatus, comprising: a first component; a second component spaced from the first component in an axial direction; and an axial brush seal assembly movably mounted between the first and second components. The brush seal assembly can move in the axial direction.
[0012] These and other objects of the present invention are achieved in another aspect by a method of sealing a gap between a first component and a second component. The method comprises the steps of: placing an axial brush seal assembly between the first and second components; and allowing the brush seal assembly to float in the gap.
BRIEF DESCRIPTION OF DRAWINGS
[0013] Other uses and advantages of the present invention will become apparent to those skilled in the art upon reference to the specification and the drawings, in which:
[0014] [0014]FIG. 1 is a perspective view, in cross-section, of one embodiment of a brush seal assembly of the present invention;
[0015] [0015]FIG. 2 is a perspective view, in cross-section, of another embodiment of a brush seal assembly of the present invention;
[0016] [0016]FIG. 3 is a cross-sectional view of another embodiment of a brush seal assembly of the present invention; and
[0017] [0017]FIG. 4 is a perspective view, in cross-section, of another embodiment of a brush seal assembly of the present invention.
DETAILED DESCRIPTION
[0018] [0018]FIG. 1 displays one alternative embodiment of the present invention. The figure provides a brush seal assembly 10 that inhibits fluid flow through a gap 11 between a first component 13 and a second component 15 of an apparatus such as a gas turbine engine. The components 13 , 15 could be stationary or rotating components. The figure shows the first component 13 as a rotating component (such as a turbine disc). The component 13 could include a ring 17 that acts as a land surface for the brush seal assembly 10 .
[0019] The figures also show the second component 15 as a stationary component (such as a turbine nozzle). Since the component 15 remains stationary, no need exists for a ring to provide a land surface like the rotating first component 13 may require. As seen in the figures, multiple elements could form the stationary component 15 . Alternatively, both components could be stationary components such as adjacent sections of the engine case, compressor stators and the engine case, or turbine nozzles and the engine case.
[0020] During operation of the gas turbine engine, the components 13 , 15 exhibit high axial growth transients. In other words, the components 13 , 15 move substantially in the axial direction during operation. Although a secondary consideration, the present invention can also accommodate radial growth transients.
[0021] The brush seal assembly 10 serves to inhibit flow through the gap 11 between the components 13 , 15 despite the growth transients. Generally speaking, the present invention allows movement of the brush seal assembly 10 to ensure an adequate seal despite substantial growth transients. For example, a substantial growth transient could reduce or increase the gap 11 by up to approximately 15% in the axial direction.
[0022] The brush seal assembly 10 is preferably an axial brush seal assembly. The brush seal assembly 10 could use a separate brush seal for each component 13 , 15 as seen in FIGS. 1 and 2. Alternatively, the brush seal assembly 10 could be a single brush seal that engages both components 13 , 15 such as that shown in FIG. 3. The brush seal preferably has a conventional arrangement, with a bristle pack 19 secured to a backing plate 21 and a side plate 23 such as by welding the metallic pieces together.
[0023] An extension 25 bridges between the backing plates 21 . The annular extension 25 has a suitable number of circumferentially located slots 27 therein. The slots 27 are elongated in the axial direction of the engine. Preferably, the slots are not elongated in the circumferential direction to prevent rotation of the brush seal. The slots 27 could receive bushings 29 made from, for example, a suitable low friction material.
[0024] The second component 15 includes threaded blind holes that correspond to the slots 27 in the extension 25 . To secure the brush seal assembly 10 to the second component 15 , suitable fasteners, such as set screws 31 , extend through the slots 27 in the extension 25 and into the blind holes of the second component 15 . The head of the screw 31 is preferably larger than the slot 27 .
[0025] A spring 33 could surround the shaft of each of the screws 31 . The springs 33 help center the brush seal assembly 10 within the engine.
[0026] During axial growth transients, the second component 15 can move relative to the first component 13 without affecting the performance of the brush seal assembly 10 . The elongation of the slots 27 in the extension 25 allows movement of the screws 31 from the second component 15 therein.
[0027] Although a secondary consideration, the second component 15 should also be able to move relative to the first component 13 during radial growth transients without affecting the performance of the brush seal assembly 10 . The gap between the extension 25 and the second component 15 allows for such movement. The slots 27 allow the screws 31 to move therein. In essence, the present invention allows the brush seal assembly 10 to float between the components 13 , 15 .
[0028] The present invention self centers within the gap 11 . As transients increase, the bristles of the brush seal assembly 10 comply and increase their lay angle. Similarly, as transients decrease, the bristles of the brush seal assembly 10 relax and decrease their lay angle. Throughout this range of bristle movement, the brush seal assembly 10 maintains a relatively constant leakage flow rate through the gap 11 between the components 13 , 15 .
[0029] Since the screw 31 does not occlude the entire slot 27 (the slot 27 being elongated), this arrangement may produce an undesired leakage flow rate. To reduce leakage through the slots 27 , the brush seal assembly 10 could include an annular ring 35 that bridges between the side plates 23 . The ring 35 could secure to the side plates 23 using any suitable technique such as press-fitting or welding (obviously after the screws 31 have been properly secured in the blind holes). The ring 35 prevents fluid flow through the slots 27 . Other alternative techniques, however, could be used. For example, a large washer (not shown) could be placed between the inner diameter of the extension 25 and the head of the screw 31 . The washer is sized to occlude the enlarged slots 27 at any position of the screw 31 within the slot 27 .
[0030] [0030]FIG. 2 displays another alternative embodiment of the present invention. The figure displays a brush seal assembly 100 that inhibits fluid flow through a gap between a first component 101 and a second component 103 of an apparatus such as a gas turbine engine. Similar to the aforementioned embodiment, the first component 101 is preferably a rotating component and the second component 103 is preferably a stationary component.
[0031] The brush seal assembly 100 includes a bristle pack 105 sandwiched between backing plates 107 and side plates 109 . Similar to the aforementioned brush seal assembly 10 , the brush seal assembly 100 includes an extension 111 that bridges between the backing plates 107 .
[0032] Differently than the aforementioned brush seal assembly, the annular extension 111 has a suitable number of threaded holes therein. The holes receive a suitable fastener such as a plunger assembly 113 . The plunger assembly 113 includes a set screw 115 with a plunger 117 extending from the distal end. A spring (not shown) within the screw 115 biases the plunger away from the head of the screw 115 . The spring within the screw 115 also helps center the brush seal assembly 100 within the engine.
[0033] To secure the brush seal assembly 100 to the second component 103 , the operator urges the brush seal assembly 100 towards a shoulder 119 of the second component 103 . As the brush seal assembly 100 approaches the second component 103 , the plunger 117 will eventually abut a chamfer 121 on the second component 103 . Continued urging of the brush seal assembly 100 towards the shoulder causes the chamfer 121 to depress the plunger 117 . Eventually, the brush seal assembly 100 arrives adjacent the shoulder 119 . The plunger 117 will encounter one of a plurality of elongated slots 123 in the second component 103 . The spring biases the plunger 117 into the elongated slot 123 . The brush seal assembly 100 is now fully secured to the second component 103 . To remove the brush seal assembly 100 , the plunger assemblies 113 could be unscrewed from the extension 111 . Alternatively, the brush seal assembly 100 may be removed from the second component 103 by disengaging the plunger 117 from the slot 123 . Conventional techniques to disengage the plunger 117 include providing the proximal end (the end opposite plunger 117 ) of the plunger assembly 113 with pull levers, knobs or rings (none shown). The operator can actuate these pull levers, knobs or rings to withdraw the plunger 117 from the slot 123 .
[0034] During axial growth transients, the second component 103 can move relative to the first component 101 without affecting the performance of the brush seal assembly 100 . The elongation of the slots 123 in the second component 103 allows movement of the plunger assemblies 113 therein.
[0035] Note that the plunger assemblies 113 completely occlude the holes in the extension 111 . As a result, no leakage paths exist in the extension 111 . Therefore, the brush seal assembly 100 does not require the annular ring 35 used by the aforementioned brush seal assembly 10 .
[0036] [0036]FIG. 3 displays another alternative embodiment of the present invention. The figure displays a brush seal assembly 200 that inhibits fluid flow through a gap between a first component 201 and a second component 203 of an apparatus such as a gas turbine engine. Differently than with the earlier embodiments, both components 201 , 203 are preferably stationary components.
[0037] The brush seal assembly 200 is preferably a single axial brush seal. However, the brush seal assembly 200 could use separate brush seals for each component 201 , 203 as seen in FIGS. 1 and 2. The brush seal assembly 200 includes a bristle pack 205 secured to a backing plate 207 and a side plate 209 (with an integral windage cover) such as by welding the metallic pieces together.
[0038] The brush seal assembly 200 can reside within an annular slot 211 in the first component 201 . Preferably, the slot 211 is sized to allow the brush seal assembly 200 to move axially (i.e. parallel to centerline L of the engine) within the engine to accommodate axial growth transients. In addition, the slot 211 is sized to generally limit radial movement of the brush seal assembly 200 in the engine.
[0039] As necessary, the slot 211 could have a plurality of circumferentially spaced keyways 213 in communication therewith. The keyways 213 accept splines 215 radially extending from the backing plate 207 . This arrangement prevents the brush seal assembly 200 from rotating.
[0040] [0040]FIG. 4 displays another alternative embodiment of the present invention. The figure shows a brush seal assembly 300 that inhibits fluid flow through a gap between a first component 301 and a second component 303 of an apparatus such as a gas turbine engine. The first component 301 is preferably a rotating component and the second component 303 is preferably a stationary component.
[0041] Similar to the aforementioned brush seal assembly 200 , the brush seal assembly 300 is preferably a single axial brush seal. The brush seal assembly 300 could, however, use separate brush seals for each component 301 , 303 . The brush seal assembly 300 includes a bristle pack 305 secured to a backing plate 307 and a side plate 309 (with an integral windage cover) such as by welding the metallic pieces together.
[0042] An extension 311 projects from the backing plate 307 . The annular extension 311 has a plurality of elongated slots 313 therein. The slots 313 extend in the axial direction of the engine. Preferably, the slots 311 are not elongated in the circumferential direction to prevent rotation of the brush seal. A boss 315 surrounds each slot 313 . The boss 315 /slot 313 could have a low-friction coating thereon, or a bushing (not shown) made from a low friction material could be placed in the slot 313 .
[0043] Suitable fasteners, such as set screws 317 , extend through the slots 313 to mount the brush seal assembly 300 to the second component 303 . A coil spring 319 surrounds the fastener 317 . The spring 319 serves to bias the extension 311 away from the head of the fastener 317 and towards the second component 303 .
[0044] The fastener 317 sufficiently compresses the spring 319 to urge the extension 311 against the second component 303 . However, the spring 319 should also permit movement of the second component 303 relative to the brush seal assembly 300 by allowing the fastener 317 to move with the elongated slot 313 . The spring rates of the bristles of the bristle pack 305 keep the brush seal assembly 300 centered within the gap between the components 301 , 303 . This centering capability also allows the fasteners 317 will move within the slots 313 .
[0045] This arrangement allows movement of the second component 303 relative to the first component 301 without affecting the performance of the brush seal assembly 300 . The elongation of the slots 313 in the extension 311 allows movement of the fasteners 317 therein. In other words, the present invention allows the brush seal assembly 300 to float between the components 301 , 303 in the axial direction.
[0046] The present invention has been described in connection with the preferred embodiments of the various figures. It is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function of the present invention without deviating therefrom. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims.
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A brush seal assembly for sealing a gap between a first component and a second component, comprising: a body; bristles extending from the body; and an extension from the body, the extension having an elongated slot therein. The slot, when the brush seal assembly mounts between the first and second components, allows the brush seal assembly to float within the gap. An axial brush seal assembly, comprising: a body; bristles extending from the body; and means for allowing movement of the brush seal assembly in an axial direction within the gap. An apparatus, comprising: a first component; a second component spaced from the first component in an axial direction; and an axial brush seal assembly movably mounted between the first and second components. The brush seal assembly can move in said axial direction.
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RELATED PREVIOUS INVENTIONS
In U.S. Pat. No. 5,029,760 issued Jul. 3, 1991, U.S. Pat. No. 5,205,499, issued Apr. 27 1993, and in a U.S. patent application of even dale herewith entitled "Improved Planetary Grinding Apparatus", I describe various configurations of planetary grinding systems that have the capability of being continuously fed without the use of rotating seals. This invention is an improvement upon such devices and upon ball mills.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of grinding or comminution and dispersion and more particularly to the reduction of solid matter into fine particles.
The reduction of solid matter into fine powders is a major task of an industrial society. As an example Portland cement is made from finely ground limestone, clay or shale, sand, and coal or other fuel. The limestone, clay or shale, and sand are subjected to a thermal process in which the heat is derived from the coal and the results are clinkers of material that must again be ground to produce the cement. Gypsum, after calcining, must be ground to produce sheet rock and other such products.
The food industry grinds many products including wheat, corn, rice, spices, sugar, and even chocolate. Paints, inks, and so forth use ground pigments and in turn undergo a dispersion process to disperse the ground pigment in a suitable vehicle.
Ceramics are made from finely ground materials. Generally the better the grind the better the ceramic product. Metals are ground as part of powder metallurgy and to prepare metallic pigments.
2. Description of the Prior Art
One of the oldest and simplest methods of grinding materials to fine powders uses a ball mill that generally consists of a horizontal cylindrical chamber that may be of any size. Ball mills have been constructed in sizes of up to eighteen feet in diameter by fifty or sixty feet long.
For many applications the ball mill is about half full of steel or ceramic balls in addition to the material to be ground. The balls roll over one another and aid in the grinding process.
In cases where the material to be ground, such as a paint, consists of a fine pigment to be dispersed, the balls, usually called the grinding media, are essential to the process while in other cases such as the grinding of cement clinker, the media is omitted. In this latter case the larger clinkers act as media for the smaller ones and a means is usually provided for extracting only the finer particles from the mill.
While the ball mill is effective and reliable, it tends to be large and slow. The physical size of the mill tends to cause it to be high in capital cost for the amount of work done.
There is much art having to do with overcoming the deficiencies of the ball mill. Alternative approaches to the task of grinding include mills wherein a material is stirred with media by means of mandrels. In another approach the material being ground in a liquid carrier is subjected to high shear rates by high speed blades or by being forced through narrow gaps between rapidly moving surfaces. These devices are most useful for dispersion while a ball mill both grinds and disperses.
In yet other attempts to obtain the benefits of a ball mill while overcoming its deficiencies, considerable prior art has addressed planetary mills in which the grinding chamber is orbited about an axis parallel to the axis of the grinding chamber. In such art the planetary motion imparts a centrifugal force that aids the action in the grinding chamber.
In U.S. Pat. No. 5,029,760 I describe a system wherein a rotatable drum assembly carries two rotatably mounted grinding tubes that are constrained to have no net rotation with respect to the base of the machine. Access to the grinding tubes may be made only to their ends and only one of the two grinding tubes may be addressed from either end. A second embodiment uses a series of four rotating wheels that drive two oppositely mounted frames that each carry one or more grinding tubes.
In U.S. Pat. No. 5,205,499 I describe a rotatable drum assembly that carries a single grinding tube that has advantages of permitting access to the grinding tube from both ends.
In a separate application of even date herewith entitled, "Improved Planetary Grinding Apparatus", I have described an improvement to the systems described in both of these previous patents wherein the improvement permits more ready access to the grinding tubes so that continuous feeding of the device is easier and more flexible than with previous methods.
Ball mills and planetary mills have in common that both use cylindrical grinding chambers that rotate in a force field that is perpendicular or almost perpendicular to the axis of rotation. This force field, in the case of a ball mill, is the gravitational field of the earth and, in the case of a planetary mill, is the centrifugal field generated by the planetary motion. Because of the equivalence of forces due to acceleration and gravitation, it can reasonably be said that ball mills and planetary mills both operate due to inertial fields.
It is advantageous to operate both ball and planetary mills in a continuous manner, with continuous feed being especially important for planetary devices. With ball mills the volume of the mill tends to be quite large, and the time required for grinding long. In a batch mode, that is, where the device is filled, run and then emptied, then refilled and so forth, ball mills might be loaded once a day and allowed to grind for twenty four hours. Though the time required for grinding is long, since the mill is large, significant production takes place and loading and unloading the mill is not an undue burden.
Still, even in the case of ball mills, it may be convenient to operate the mill continuously and to feed and withdraw material as steady streams. In such a case the mill needs almost no attention and production takes place with minimal labor content.
With a planetary mill, however, the volume of the mill tends to be small and the time for grinding only a few moments. If continuous feed is not used, much of the operating cycle may be spent in starting and stopping and loading and unloading the mill. In the case of a planetary mill it is usually a practical necessity that the device be continuously fed.
As has been discussed at length in my previous patents, listed above, it is possible to construct planetary mills that achieve continuous feed and withdrawal of the material being ground without rotating seals. Ball mills, on the other hand, appear to require such seals. Fortunately ball mills rotate at a relatively slow rate so that rotating seals are not much of a problem with continuous feed systems for such mills.
Two major problems exist with continuous feed systems. The first is that since the mill is usually a single cylinder, material that is insufficiently ground may by-pass grinding in the mill and be found in the output so as to compromise the grind. This problem can be overcome by making the mill long compared to its diameter, or by dividing the mill into separate connecting chambers so that equilibration tends to take place in stages (such an arrangement is sometimes called a tube mill).
The second problem has to do with the separation of media used for grinding in the mill from the material being ground. Especially in the case of planetary mills, wherein the grinding tube may be quite small in volume compared to the volume of the material going through the mill per unit time, there is a tendency for media to be carried along with the ground material. Since any media retained with the ground material tends to be a major problem, precautions need be taken to prevent media from being mixed with the product from the mill.
This problem has become especially severe in recent times because demand for ever finer grinds has led to the use of ever finer media in milling machines in general. This invention addresses this particular problem by providing for helical chambers at each end of a mill that tend to screw media back toward the center of the mill while permitting free flow of the material being ground.
SUMMARY OF THE INVENTION
In the present invention I describe an improvement to ball mills or planetary mills, mills such as the ones I have described in the inventions listed above, that gives a powerful, dynamic separation of the media used in the mill from the material being ground.
Each grinding tube in the mill has a longitudinal section at each end of its length that has a helical chamber that wraps helically around or within and coaxial with the grinding tube. If a helical chamber at one end has a right hand orientation, the helical chamber at the other end is left handed. When the mill is rotating in the appropriate direction, the media is constantly driven toward the center of the grinding tube by the screw action of the helical chambers.
Input and output connections to the mill are made at the ends of the helical chambers most remote from the center of the grinding tube. Material entering the mill can readily be pumped through the helical chamber to the center of the mill where it is ground, but the media, which has a different specific gravity than the material to be ground, is driven to the outer wall of the helical chamber by the force field inherent with ball and planetary mills. At the wall of the helix the media is moved by the relative rotation of the helix axially toward the center of the grinding tube.
It is not obvious, but it is true that the specific gravity of the media need only be different from that of the material being ground, that is, the media may have either a greater or lesser specific gravity than the material being ground. In either case the media will be driven toward the longitudinal center of the mill as it operates. If the media and material have the same specific gravity, then, as with most media mills, no grinding takes place, and in the case of the instant invention no separation of the media from the material being ground takes place.
In the case of planetary mills, the centrifugal forces in the mill enhance the forces that cause separation of the media from the material being ground so that especially clean separations take place even in difficult situations. The forces that operate in planetary mills are described in more detail (and more quantitatively) below.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of the vectors that determine the location through time of an element of material moving with the grinding tube of a planetary mill.
FIG. 2 is a side view of a grinding tube that has a helical chamber at either end in accord with the teachings of the invention.
FIG. 3 is a side view of such a grinding tube incorporated in a planetary milling machine.
DETAILED DESCRIPTION OF THE INVENTION
In the case of a ball mill, it has long been known that grinding of material into a fine powder and homogeneous dispersion of fine powder can be obtained if the mill is operated for a sufficiently long time, e.g. 24 hours. Grinding results from the cascading of the balls against each other, the wall of the mill, and the material to be ground. Cascading of the balls results from the fact that the rotation of the cylindrical grinding chamber and the viscosity of the material to be ground tends to carry the balls up the walls of the grinding chamber until the force of gravity cause the balls and the material to be ground to flow. At high rotational speeds, the centrifugal forces developed overcome the gravitational forces developed and neither cascading nor grinding occurs. The grinding power of a ball mill, which determines its capacity, is directly related to its size.
However, if the grinding chamber is orbited about an axis parallel to its own axis and rotated about its own axis in the opposite direction at a rate of one rotation per orbit, the grinding chamber will maintain a fixed orientation with respect to the machine base.
The analysis of such a mill starts by defining three vectors which are diagramed in FIG. 1. The first is from the center of rotation of the planetary motion to the center of the grinding tube and is called R1. The second vector is any vector from the center of the grinding tube to any point on the grinding tube. This vector is R2. The third vector is the sum of R1 and R2 and thus is a vector from the center of the planetary motion to any point on the grinding tube. Symbolically R is given by R=R1+R2.
Let the second derivative of R with respect to time be taken when the mill is in operation. As observed above the grinding tube always maintains its orientation in space so that R2 does not vary with time. Both its first and second derivatives are thus zero, and the second derivative of R is the same as the second derivative of R1, which, in turn, is a vector of magnitude w 2 R1 pointed toward the origin, where w is the rotational speed in radians per second. What all this means is that an element of material carried by the grinding tube and rotating with this tube experiences forces exactly as if it were in a gravitational field of magnitude w 2 R1.
In the case of a ball mill it has been observed that the best grinding action takes place when the media in the mill is at about a 45 degree angle. This angle is observed when the ratio of force due to centrifugal force is about 1/2.15 that due to gravity. In the case of the planetary mill, the force that is comparable to gravity is given as w 2 R1 while that comparable to the centrifugal force is given by w 2 R2. In the case of a planetary machine, again the ratio of the centrifugal force to the equivalent of the gravitational force must be taken as 1/2.15 in order to maintain a 45 degree grinding angle. When this ratio is taken, however, the speed of rotation drops out, and it can be seen that the condition for the 45 degree grinding angle is just that R1 and R2 be in the ratio of 1/2.15.
The fact that the rotation speed drops out means that the media angle in the mill is independent of rotation speed. Such a result is certainly desirable since, as opposed to a ball mill, the maximum speed of rotation and thus the grinding action is not limited by the force of gravity.
The power consumed by a such a centrifugal mill can be related to the energy expended in raising the media against the centrifugal force of the planetary rotation. Thus the power consumed by a centrifugal mill is given by:
P=4.785×10.sup.-2 d l w.sup.3 R1 .sup.4 watts
(P=3.083×10.sup.-9 d l (rpm).sup.3 R1 .sup.4 horsepower)
where R1 is the radius of planetary motion and is in meters (feet), L is the length of the grinding tube in meters (feet), d is the mill base density in kilograms per cubic meter (lbs. per cubic foot), w is the rotation rate in radians per second, and (rpm) is the rotation rate in rounds per minute.
The grinding power of a ball mill is directly related to the power consumed in its operation. In the same way the grinding power of a planetary mill is also given by the power consumed in its operation. The grinding power of a planetary mill having a single 5.6 inch diameter grinding chamber and a length of 2.0 feet orbiting at 1000 rpm on an orbital diameter of 1.0 foot and employing 1/16 inch diameter balls is about the same as that of a conventional ball mill 4 feet in diameter and eight feet long rotating at 21 rpm and employing 3/8 inch diameter balls.
What has been achieved is the power to grind large quantities of material per unit time in a small apparatus. The capital cost of the device is reduced, but the flexibility is greatly increased. For example suppose a ball mill is being used to make black ink and it is desired that yellow ink be produced instead. In the case of a ball mill a very large quantity of media must be washed free of black ink to accomplish the task. In the case of a planetary mill only a small volume need be cleaned. A practical alternative exists in the case of the planetary mill to have two grinding tubes, one for yellow and one for black. Such an alternative is, of course, not practical with a ball mill.
The basic nature of both a ball mill and the planetary mills addressed by this invention involve the rotation of a cylindrical tube with its axis perpendicular to an inertial field. In the case of a ball mill this force is furnished by the force of gravity and, as discussed above, in the case of a planetary mill this force arises from the centrifugal force caused by the planetary motion. Generally speaking the forces involved with a planetary device are many times the force associated with gravity.
In the case of a planetary mill, the force driving a particle of media, which depends upon the force field, is correspondingly greater. The rate of fall of a spherical ball in a viscous fluid in response to a force field can be calculated by means of Stokes law. This law establishes a linear relation between the rate of fall of the ball and the intensity of the force field. In the case of a planetary mill that has an effective force field sixty times as strong as gravity, we should expect that separation of the media from the material being ground occurs sixty times faster.
In the case of the helical chamber that leads material out of a mill, it can be seen that if the orientation of the rotation of the mill is in the appropriate direction, the media, provided it can reach the wall of the device during the time it takes an element of fluid to flow around a half turn, will be driven counter to the flow and back toward the grinding tube. It is also readily seen that the fact that the force field on the media is enhanced in the case of a planetary mill leads to powerful forces that tend to separate the media from the material being ground. It is this principle that permits the helical chambers in a planetary mill to act to powerfully to separate the media on a dynamic basis.
Reference is now made to FIG. 3 which represents a side view of one embodiment of the instant invention. End supports, 1, which are placed rigidly upon a fixed datum, support bearings, 2, that rotatably mount shafts, 3. Shafts, 3, connect rigidly to and carry rotors, 4, that, in turn, are rotatably mounted to grinding tube holder, 5. The ends of grinding tube holder, 5, project through the rotors, 4, and are rigidly connected to sprockets, 6, that in turn are interconnected by means of chains, 7, to sprockets, 8. Sprockets, 8, are rigidly connected to base, 1. By this means as the rotor rotates so as to impart planetary motion to the grinding tube carrier, the grinding carrier is constrained by sprockets 6 and 8, interconnected by means of chain, 7, to contra-rotate about its own axis at the same rate and opposite in sense to the planetary rotation of the grinding tube.
This combination of motions results in access tubes, 9, to the grinding tube, 10, which is rigidly mounted in the grinding tube holder, remaining in a vertical orientation as the grinding tube holder undergoes planetary rotation. The ends of the access tubes undergo the circular motion of the planetary rotation, but do not twist about their own axis, and as noted above, always point up. These tubes may be connected rigidly to external flexible tubes (not shown) that in turn rigidly connect to the external environment.
Shafts, 3, are driven by sprockets, 11, that in turn are driven by chains, 12, that in turn are driven by sprockets, 13. Sprockets, 13, are rigidly mounted upon jackshaft, 15, that is, in turn, driven by sheave, 16. Sheave, 16, is driven by belt, 19, that is driven by sheave, 17, that in turn is driven by motor, 18. The ratio of the size of sheave, 18, to sheave, 16, is selected to provide for an optimum rotation speed of the mill for a standard motor speed.
The helical chambers at each end of the grinding tube have the purpose of separating any media from the material being ground and returning it to the center region of the tube. Consider FIG. 1 with the grinding tube undergoing notion as shown. Now consider the helical chamber shown in FIG. 2 at the left of the grinding tube. The helix shown is a right hand screw. Such handedness is related to the human hand and means that if one places ones right hand so that the fingers wrap around the helix the thumb of the hand will point in the direction of advance of the helix if the screw is right handed. Otherwise the screw is left handed.
It is perhaps not obvious, but the property of handedness of a screw is inherent to the screw. Turning a screw through a 180 degree angle about an axis perpendicular its own axis or wrapping ones fingers from the opposite side of the screw does not affect the result achieved with the handedness test described above.
If the helical chamber at the left of the grinding tube were mounted so that it were found closest to the observer in the diagram shown in FIG. 1, since the higher density grinding media would be thrown to the outside of the grinding tube, but the tube would rotate clockwise relative to this outside position, the grinding media would be moved axially by the helical chamber. In the case shown the media would be driven axially away from the observer, that is, toward the center of the grinding tube.
Should the media have been less dense than the material being ground, the media would have been found at a position around the grinding tube about 180 degrees from that of the more dense media. However, it is readily seen that the screw action would still move the media in the same direction. The only condition that must be met is that the force perpendicular to the helical axis (that is, the inertial field) act in such a way that the element to be separated seeks a wall and thus become trapped by the helix and subject to its screw action,
In the actual operation of a mill of the type shown in FIG. 3, the mill will be set in motion and a fluid be pumped in the inlet and extracted from the outlet of the grinding tube. The fluid being pumped in most likely will entrain the material to be ground in the presence of the fluid. Generally speaking the operator of the system will increase flow to the point where the grind achieved just meets measures of the specified level of fineness, It is perhaps not appropriate to discuss here the technical details of how such measurements are done. Suffice it to say there exist grind gages and so forth for various grinding tasks that permit fairly accurate control over the results achieved.
At the level of flow achieved with a particular mill, it is the objective of this invention that the helical chamber separate the media from the stream of material at the output and place it back into the center region of the grinding tube. Consider, for example the case of a helical chamber with a one inch cross section in a mill capable of grinding at the rate of ten gallons per minute. The rate of flow required gives rise to a fluid flow rate of about 100 cm per second in the helical chamber.
If we consider the viscosity of the material to be ground as one poise and consider grinding media one millimeter in diameter it will be seen that in a mill operating with a g field of a little over sixty times gravity, the rate of fall of the ball in the material being ground is about ten times faster than the transport rate of material in the helical tube, that is about 1000 cm per sec.. In such a case the media cannot be entrained in the material being ground, that is, the media will fall to the wall in the inertial field so that there is a clean separation of the material being ground from the media.
In the case of a ball mill, the rate of flow is much less and the media size larger so that conditions can readily be found wherein the mill operates so as to reject the media while permitting the material being ground to flow from the mill.
In any particular case the pitch of the helix must be selected as well as any taper from one end to the other. Further the size of the central core or root of the helix must be selected as must be the shape of its cross section. The configuration shown in FIG. 2 is one particular realization. This particular configuration is readily constructed by welding a coil of flat stock, say of steel or plastic, to a central core and gluing or welding the whole inside the grinding tube as shown.
Other procedures such as wrapping tubing around a core and joining the end to an appropriately shaped hole in the grinding chamber by welding, gluing, clamping or so forth is an alternative for the realization of a helical chamber. More than one helical chamber may be run in parallel at each and by using two coils or two tubes that run in parallel. In such a case provision would need to be made for connecting each such tube to the inlet and outlet tubes.
A helix is defined mathematically by defining the motion of a point with respect to an orthogonal coordinate system. This motion is described by a point that undergoes a constant circular motion with respect to two of the coordinates while simultaneously undergoing uniform rectilinear motion along the third coordinate. A somewhat more general spiral motion involves a growing or decreasing spiral in one plane along with rectilinear motion in the direction perpendicular to this plane. The helical chambers described herein can be defined by the locus of points generated by a rigid plane, all of whose points move in a parallel spiral path.
The pitch of a spiral chamber can be described as that angle whose tangent is given by the ratio of the rate of advance divided by the rate of circular motion. Alternatively it can be defined as the angle the spiral makes with the plane defined by the circular motion.
The helical chamber in the radial direction has an inner limit or core that is called the root or core diameter. It also has an outer diameter which is conveniently selected to be the same as the inner diameter of the grinding tube though such an arrangement is not a requirement for proper operation of the system. Similarly the root diameter can be selected to range from near zero to a fraction slightly less than one of the outer diameter. I have found that such chambers that have a ratio of root diameter to outer diameter of between about 0.3 to 0.8 to be preferred.
In FIG. 2, as shown, the outer diameter of the helical chamber is the same as the inner diameter of the grinding tube and the core diameter is about one third the outer diameter. The helical chamber can have any number of turns ranging from less than one, that is a fractional number of turns, to perhaps as many as twenty, where a turn refers to the number of times the helix returns to its starting point in a projection onto the plane of its circular motion.
The desired pitch of the helical chamber used with grinding tube, as well as the number of turns involves a consideration of the conditions under which the mill operates. If the pitch angle is low, the media can more readily be carried counter to the desired stream by the flow of the material being ground. By the same token a high pitch angle requires a longer chamber to achieve a particular axial length of helix. Under this condition there may occur undesirable pressure drops. In most cases a few turns of moderately high pitch (such as, say, fifteen degrees from the vertical) and perhaps a total four to five turns appears to be desirable.
The core diameter also is not critical. If this number is small the cross sectional area of the helical chamber is large, bringing about a lower rate of flow for a given volume of material processed per unit time. On the other hand, it can readily be seen that a small root or inner core on the helix permits material to more readily be carried from turn to turn through the helix, counter to the desired direction. I have found the most preferred arrangement to be a core diameter about one half the outer diameter of the helix.
It is to be realized that the desired properties of the helical lead in and lead out chambers may be different from each other, and in any case are dependent upon the tasks faced by a particular grinding device. A machine grinding high viscosity oily materials, such as offset inks, might require relatively large helical chambers of only a turn or two at the outlet and essentially no chamber at the inlet. On the other hand the dry grinding of cement where the grinding fluid itself is air might require a number of turns of relatively high pitch and small cross section at both the outlet and inlet.
In some cases multiple grinding tubes may be used in series to accomplish a particular grinding task. As mentioned above, a ball mill may be divided into sections with connections between each section and be called a tube mill. Similarly, in some of my previous patents, discussed above, multiple grinding tubes that may be connected in series are described. In such cases, helical chambers may be used at the ends of all units treated as one, or each grinding tube may independently have input and output helical chambers. Such choices will be made by the designer of a system to accomplish a particular task and determined by the nature of the task to be accomplished.
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A mill for comminution comprising a cylinder rotating with its axis perpendicular to a uniform inertial force field that has helical chambers at each end of the cylinder that are coaxial to and connected with the cylinder. The other end of each helix is connected to an external connection such that one feeds into and the other removes material from the mill. The helical chambers have opposite senses of rotation so that when the mill is rotated in one of its two possible directions any media in the mill is dynamically retained in the mill by the screw action of the helices even as material to be ground flows through the mill.
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This application claims the benefit of U.S. Provisional Application No. 60/137,146, filed Jun. 1, 1999, the disclosure of which is hereby incorporated herein by reference.
This invention was made with Government support under Grant no. HG01506, awarded by NIH. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
The present invention relates, in general, to the efficient separation of molecules such as DNA and proteins, and more particularly to a separation device including nanofluidic channels of different sizes for providing alternate thin and thick regions along a channel to act as a filtering or sieving structure.
The separation of molecules according to their sizes is an essential step in biology and other fields and in analytical procedures such as chromatography, DNA sequencing or genome mapping. Conventional methods for separating molecules include electrophoresis and chromatography, which utilize the different transport properties (mobility) of different molecules in a solution-filled capillary or column. In many cases, additional sieving material, such as a gel matrix, is required to obtain sufficient separation of the molecules to permit analysis. In a conventional gel electrophoresis, as an example, molecules such as DNA molecules are separated during an electric-field-driven motion in a highly restrictive gel matrix, because the mobility of the molecules is dependent on their length. However, this length-dependence of molecule mobility vanishes for DNA molecules longer than about 40,000 base pairs, mainly because the molecules tend to be more stretched and oriented in the direction of the applied electric field. Molecules as long as 10,000,000 base pairs can be separated by pulsing the electric field (pulsed field gel electrophoresis), but this process is usually very time consuming and inefficient.
To obtain better efficiency and control for separation process, the use of an artificial system using a precisely defined microchannel structure as a molecular sieve has been suggested. However, initial attempts to produce efficient artificial gel systems were hindered by poor understanding of the molecular dynamics in the microchannels. It has been found that the conformation (shape) of DNA or other polymer molecules has a direct impact on their motion in a restrictive medium because the interaction cross section of the molecules with obstacles is changed with conformational change. In free solution, polymer molecules such as DNA have a spherical shape in their equilibrium state, and the size of this equilibrium shape is characterized by a radius of gyration (R o ) of the molecule. In the separation process of DNA or other polymers, it is important to maintain the conformation of the molecule in its equilibrium shape as much as possible, because otherwise the polymeric molecule will stretch out in the direction of the motion, rendering the mobility of the molecule length (size) independent. This is because there is minimal difference in their interaction with a retarding matrix such as gel or obstacles.
In terms of the fabrication of artificial gel systems, current photolithography techniques are limited in resolution at about the 1 micrometer level. Therefore, one cannot easily make constrictions or obstacles small enough for the separation of important molecules (DNA, proteins etc). Electron beam lithography can fabricate smaller features but it generally is too expensive, and it is difficult to produce a large-area device with this process.
It became clear that a more careful design of a separation device, combined with an inexpensive technique that can produce many ultrasmall constrictions over a large area, is essential in developing a functioning molecular separation device.
SUMMARY OF THE INVENTION
When molecules become relaxed or are in their equilibrium spherical shape, their interaction with a retarding matrix can be dependent on the molecule's radius of gyration (R o ), and in turn on the length of the molecule. Accordingly, a design for a molecule sieving structure should include a somewhat open area where molecules can relax, as well as narrow constrictions that can serve as a molecular sieve.
It is, therefore, an object of the present invention to provide a separation device incorporating nanofluidic constrictions (thin regions) and obstacle free regions (thick regions), through which molecules can be caused to flow either by electrophoresis or by non-electric forces.
Briefly, the device of the invention provides a flow channel incorporating alternating thin and thick regions which operate as a filter, or sieving structure. The thin regions are sufficiently small to act as constrictions to the flow of small objects, such as DNA molecules, proteins, cells, viruses, or other similarly-sized particles, while the thick regions allow molecules to relax for more efficient separation at the thin region. To this end, the thick region depth may be made comparable to, or substantially larger than, the size of a molecule (for example, the radius of gyration R o for polymer molecules) to be sieved. Also the thin region depth may be made substantially smaller than the size of the molecule or other object to be sieved. Although the device of the invention can be used to filter a variety of objects, the following description will be in terms of molecules, and particularly DNA molecules for convenience.
Accordingly, the present invention is directed to a nanofluidic channel in which the motion of molecules such as DNA molecules is characterized by the provision of molecular traps. In accordance with the invention, an elongated nanofluidic channel is provided with alternating regions of thick and thin gaps along its length. The equilibrium spherical shape of a molecule such as DNA or protein has a radius of gyration R o , which is the shape the molecule assumes when it is relaxed in an open region, such as in the thick regions of the channel. If the molecule is forced to enter a constriction that is much less than R o , the molecule has to be deformed from its equilibrium shape. Since such a deformation is entropically unfavorable, a driving force is required to force the molecule to enter the constriction. This effect is referred to as the entropic trapping of a long polymer, and this effect is crucial in the operation of present invention.
The entropic trapping effect can be utilized in operations such as molecular trapping, molecular band formation, molecular separation and sieving, and molecular flow manipulation in nanofluidic or microfluidic channels. The separation or sieving can be achieved when a suitable driving force is supplied to trapped molecules, when they migrate across many molecular traps and get separated because of the size-dependent trapping effect. Just before the migration through the thin regions, molecules are sieved by entropic trapping effect. After the molecules pass through the thin region, they relax back to their equilibrium shape quickly because of the existence of the thick regions. This process is repeated many times until the required separation is achieved. By controlling the driving force for the molecules, molecular trapping and manipulation can be achieved with the same structure.
In accordance with one embodiment of the invention, a new method was used to fabricate a nanofluidic channel having narrow constrictions (thin regions), spaced along the length of the channel, with the depth of the thin regions ranging between about 10 nm and about 500 nm, and having relatively thick regions between adjacent constrictions, of between about 0.5 micrometer and about 10 micrometer. Channels of these approximate dimensions may be referred to herein as nanofluidic channels, or simply as nanochannels. In accordance with this method, channels with variable depths were defined and etched in a silicon substrate, or wafer, using two-level photolithography. After a thermal oxidation process, mainly for electrical isolation, the top surface of the device was covered with a thin transparent plate. This technique permitted easy fabrication of very narrow gaps or constrictions without the need for e-beam lithography for the patterning of sub-micrometer features. This process was accomplished by the use of differential etching of two regions and the bonding of a capping layer.
BRIEF DESCRIPTION OF DRAWINGS
The foregoing and additional objects, features and advantages of the present invention will be apparent to those of skill in the art from the following detailed description of preferred embodiments thereof, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a diagrammatic cross sectional view of an entropic trapping nanochannel in accordance with the present invention;
FIG. 2 is a diagrammatic top plan view of an entropic trap, which illustrates the separation mechanism;
FIGS. 3 through 7 diagrammatically illustrate the fabrication process for the nanofluidic sieving device of the present invention;
FIG. 8 illustrates one embodiment of the nanochannel of the invention in combination with cathode and anode electrodes and two loading reservoirs;
FIG. 9 graphically illustrates the mobility of two different DNA species versus electric field in a nanofluidic sieving channel;
FIG. 10 illustrates the collection of DNA, launching, separation and detection of DNA bands, in one preferred embodiment of the invention; and
FIG. 11 is a diagrammatic top plan view of a multiple channel entropic trap device, where two different DNA samples can be loaded and separated simultaneously.
DESCRIPTION OF PREFERRED EMBODIMENT
Turning now to a more detailed consideration of the present invention, there is illustrated in FIG. 1 a nanofluidic sieving device 10 in accordance with the present invention. The device 10 includes a silicon wafer or substrate 12 in which is fabricated a nanofluidic channel 14 having alternating thick regions 16 and thin regions 18 along its length. The channel 14 preferably is covered by a transparent top plate 22 which is bonded to the substrate 12 along the edges of the channel. The nanochannel 14 is filled with a buffer solution or other liquid containing DNA molecules or other polymer molecules 20 to be separated. It will be understood that any desired material such as glass or plastic may be used as the substrate 12 , and as the transparent coverplate 22 , and any conventional bonding techniques can be used to seal the coverplate 22 to a particular substrate 12 .
In the illustrated embodiment of the invention, which is specific for DNA molecule separation by way of example, the thick regions 16 may be between about 0.5 micrometers and 5 micrometers in depth, or thickness, while the thin regions may be between 50 and 200 nm in depth, or thickness. The thicknesses of the thick and thin regions can be varied according to the size of the molecule 20 to be separated. The thin region 18 thickness (defined as t s ) is substantially smaller than the radius of gyration R o of the DNA or other polymer molecule 20 to be separated. The thick region 16 thickness (defined as t d ) is compatible to R o of a molecule 20 to be separated, and thus to a typical long DNA or other polymer molecule, allowing the molecule to relax to its equilibrium spherical shape in this region. Because molecules can relax in the thick regions 16 , they are entropically hindered from entering the thin regions 18 of the channel. When a molecule 20 to be separated is driven through the nanochannel 14 by an electric field or by hydrodynamic pressure, the motion of the molecule 20 will be retarded whenever it reaches the thin regions 18 .
FIG. 2 is a top view of the nanofluidic sieving channel 14 where two different DNA molecules or polymers 20 a (smaller) and 20 b (larger) were driven toward the right-hand end of the channel. Both molecules 20 a and 20 b are trapped at starting points 22 of the thin regions 18 . The larger molecule 20 b has a wider contact area with the thin region 18 , as compared with the smaller molecule 20 a (w a <w b ), which makes the larger molecule 20 b have a higher probability of escaping the trapping point and progressing through the 20 channel.
The length of the thin region 18 (defined as 1 s ) and the length of the thick region 16 (defined as 1 d ) along the length of elongated nanochannel 14 can be varied to accommodate molecules with different R o and length. Changing 1 d changes the relaxation of the molecule after it escapes the thin region 18 . As the size of the molecule 20 increases, 1 d should be increased to accommodate the increased relaxation time required for big molecules to relax back to equilibrium shape. In the illustrated embodiments, the nanofluidic channel is 30 micrometer wide (W), although other widths can be provided. It will be understood that any desired number of nanochannels with any desired combination of values of 1 s , 1 d , W, t s , t d may be provided on a wafer, or substrate.
As illustrated in FIGS. 3 through 7, nanofluidic channels such as the channels 14 illustrated in FIGS. 1 and 2, may be fabricated on a silicon wafer 30 by a photolithography and reactive ion etching technique. In an experimental fabrication of nanochannels in accordance with the invention, as illustrated in FIG. 3, a channel 32 was defined on the top surface 33 of the wafer 30 by standard photolithography, and was etched by a reactive ion etch (RIE), providing a channel having a floor 34 . Thereafter, as illustrated in FIG. 4, a second level of photolithography and chlorine RIE etching with an oxide mask were used to make spaced thick regions 36 within the channel 30 . This etching step was performed in the floor 34 of the channel 32 (FIG. 3) to produce a second, lower floor 37 in each of the thick regions, leaving in the channel a series of parallel transverse barriers 38 spaced apart along the length of the channel 32 between the thick regions. The barriers form the ends of the thick regions of the channel (region 16 in FIG. 1) with the tops 34 of the barriers forming the thin regions. The structural parameters 1 s , 1 d , W, t s , t d in FIG. 1 can be easily varied during these first two lithography steps with a high precision, and according to the specific needs of the device.
After completing the channel 32 , a pair of loading/unloading apertures 40 and 42 were fabricated at opposite ends of the channel by potassium hydroxide (KOH) etch-through using a silicon nitride etch mask. One of the two apertures 40 and 42 may serve as an inlet for a buffer solution or other liquid, containing molecules to be separated, while the other aperture may serve as the outlet for the solution and the separated molecules. Alternatively, the aperture need not be fabricated, but the channel 32 may instead be connected to other microfluidic or nanofluidic channels or chambers that have different functions, to form an integrated system.
As illustrated in FIG. 6, a thermal oxide layer 50 may be grown on all of the surface of the channel 32 and on the surface:of the wafer to a thickness of up to 400 nm to provide electrical isolation between the buffer solution and the silicon substrate. In the case where a non-conducting substrate, or wafer 30 , such as glass is used, this step may be omitted.
Finally, as illustrated in FIG. 7, the top of the channel 32 was hermetically sealed with a thin glass coverslip 52 secured to the top surface 54 of the silicon substrate 30 and its oxide coating 50 , as by anodic bonding, to provide the nanofluidic channel 56 . The coverslip 52 may be a thin Pyrex glass or other suitable material to close the channel and to provide a fluid path across the barriers 38 from the inlet end 40 to the outlet end 42 . In the case of using substrates 30 other than silicon, the hermetic seal may be obtained by suitable bonding techniques such as glass-to-glass fusion bonding or bonding with an intervening thin glue layer. The coverplate 52 is thin and transparent enough to allow the detection of separated molecules.
In one preferred embodiment of a nanofluidic channel device, as illustrated in FIG. 8, the nanofluidic sieving device 56 illustrated in FIG. 7 is turned upside down, and two liquid reservoirs 58 and 60 , respectively, are attached. Metallic wires 62 and 64 , preferably noble metals such as platinum or gold, may be inserted into the reservoirs 58 and 60 respectively, to make a cathode 66 and an anode 68 . A voltage V applied across the electrodes produces separation of molecules 20 , which is detected from the bottom side through the transparent coverplate 22 of the device 10 . The detection of molecules 20 , as an example not as a limitation, may be done by using a fluorescent dye attached uniformly to the molecules 20 and observing in the channel by an optical microscope 70 or equivalent optical detection system.
FIG. 9 is a graphical illustration of the mobility of two different (large and small) molecules versus the electric field applied as a driving force to the nanofluidic sieving channel. The driving force for the molecules in the channel may also come from hydrodynamic pressure if desired, and in such a case the pressure will be the relevant quantity, instead of the electric field as given in this example. It is understood that the mobility curves plotted versus the electric field have a sigmoidal shape as shown in FIG. 9 . The curve 80 for larger polymer molecule should be higher than the curve 82 for a smaller polymer in a particular range 84 of the electric field. If electric field is higher (in the range 86 ), the mobility is the same irrespective of the molecule size, because the driving force is too strong and the entropic trapping is negligible. If the electric field is lower (in the range 88 ), then the entropic trapping is so strong that molecules are trapped indefinitely, irrespective of their size. The electric field applied to the nanofluidic channel should be adjusted to the level corresponding to the range 84 . The specific value for this range may vary for a specific molecules to be separated. If the electric field is adjusted to the range 86 , all the molecules move at the same speed, irrespective of the size. Therefore, this range 86 may be used for recollection of already separated molecules or moving the mixture of DNA molecules from one location to another without fractionating them. The electric field range 88 allows molecules to be collected at the first entropic barrier, because in the range 88 the entropic trapping effect is too severe for DNA to overcome even a single entropic barrier within a reasonable amount of time.
As illustrated in FIG. 10, by way of an example and not limitation, if a number of molecules are supplied to channel 14 , as by way of reservoir 60 and aperture 42 , and an electric field in the range 88 in FIG. 9 is applied for a specific amount of time along the nanofluidic sieving channel 14 , one can collect many DNA or polymer molecules 20 at the first entropic trap 90 , yielding a highly defined and concentrated molecule band 92 . The concentrated band 92 may be launched into the nanochannel for band separation by switching the electric field from the value in the range 88 of FIG. 9 to the value in the range 84 of FIG. 9 . In this illustrated embodiment of the invention, two different types of DNA ( 20 a and 20 b , small and large DNA, respectively) are mixed in the band 92 . When launched into the nanochannel, the band 92 becomes separated, as it migrates through many entropic traps along the channel, into two bands, a first band 94 and a second band 96 . It is understood that the first band is composed of larger DNA 20 b , while the second band is composed of smaller DNA 20 a.
For the detection of this separation, in one preferred embodiment, one may set up a region of interest 98 and collect the fluorescent signal from the bands 94 and 96 , either optically or using other suitable methods, as a function of time. The separated bands 94 and 96 , may then be recollected at the other end of the channel sequentially, preferably in aperture 40 and reservoir 58 , or other fluidics channels may be used to redirect each band into separate microfluidic chambers.
It is imperative to note that the above-mentioned method may be utilized to fractionate mixtures with any number of different types of molecules, as the resolution permits. The resolution may be improved by applying several different optimization techniques. Having a longer channel is one way, but another important method is changing the various structural parameters mentioned in, FIG. 1 to get optimized results. For certain polymer molecules, one may optimize a specific set of conditions, including but not limited to, the structural parameters illustrated in FIG. 1, the electric field or the electric field range 84 of FIG. 10, and the overall length of the nanochannel.
As diagrammatically illustrated in the top plan view of FIG. 11, by way of example and not limitation, a multiple channel device 98 , which is capable of separating multiple samples simultaneously, may be fabricated. In this embodiment of the invention, several nanofluidic sieving channels 100 , 102 , 104 and 106 , each with a different sieving structural parameter, are connected to a larger loading and collection chamber 108 . The different structural parameters are optimized for the separation of different length ranges of molecules to be separated. The number of nanochannels which may be connected to a loading or collection chamber 108 may be increased without any difficulty in the fabrication or operation of the device, mainly to accommodate wide variety of molecules. The loading and collection chamber 108 is connected to the cathode by a wider channel 110 , and to a reservoir of sample solution by a loading channel 112 . In addition, the central collection chamber 108 is defined by two entropic barriers 114 and 116 , which enable manipulation of the molecules to be separated, which are in the central collection chamber 108 . The central chamber 108 , the loading channel 112 and the channel 110 are all supported by a supporting pillar structure 120 , mainly to prevent possible collapse of the coverplate (roof) of the channel down to the bottom.
In the embodiment of the invention illustrated in FIG. 11, there are two multiple channel devices 98 and 98 's , having two separate loading and collection chambers 108 connected to two separate sample reservoirs (sample reservoirs A and B). Each loading and collection chamber 108 is connected to the same sets of nanofluidic sieving channels 100 , 102 , 104 and 106 , with various structural parameters, and eventually all of these nanochannels 100 lead to a common anode, whereas the two loading chambers 108 also lead to a common cathode.
In the operation of the device of FIG. 11, two different samples of molecules, possibly one unknown sample to be analyzed and one known control or reference sample with size information about the fragments in the sample (in DNA analysis for example, a DNA ladder sample could serve as a reference) may be introduced into sample reservoirs. For loading the molecules into the channels, a suitable electrical potential may be applied between the cathode and the sample reservoirs, causing the molecules to enter the loading channel 112 , the central collection chamber 108 , and the channel to the cathode 110 . As a result, the central chamber 108 would be evenly filled with molecules to be separated. Then another electric field is applied between the cathode and the anode, causing molecule transport to the nanofluidic sieving channels 100 , 102 , 104 and 106 . The electric field between the cathode and the anode may be selected to have a value in the electric field range 88 of FIG. 9, so the molecules are collected at the very first barriers of each nanochannel. With this low electric field, the molecules behind the entropic barrier 114 cannot drift into the central collection chamber 108 , but pile up behind the barrier 114 . Additionally the existence of the barrier 116 makes sure that the molecules in the loading channel 112 do not drift into the central chamber 108 since there is no substantial electric field existing between the sample reservoir and the cathode. Therefore, only the molecules in the collection chamber 108 can drift into the nanochannels, providing the concentrated band discussed with respect to FIG. 10 which will be launched into each of the nanochannels.
After this process, the field may again be developed between the cathode and the sample reservoirs, causing the remainder of the molecules behind the entropic barrier 114 to be drained back to the sample reservoir, without affecting the collected molecules at the first barriers of the nanochannels 100 , 102 , 104 and 106 . This process permits control of the concentration of molecules in the launching band, which is relevant in the separation process. Also, the same process can be repeated as many times as desired, to obtain even higher concentrations of the molecules in the band.
As the separation process proceeds, the data taken from different samples can be easily detected and compared, enabling more reliable analysis. It is important to know that the number of samples to be analyzed may be increased as desired without any serious technical and operational difficulties.
Thus, there has been disclosed a nanofluidic channel for use in entropic trapping and sieving of polymer molecules such as DNA and proteins. The channel includes alternating thick and thin segments, or sections, which alternately cause DNA or other polymer molecules to stretch and to return to a rest equilibrium configuration. The channel permits separation of long polymers in a DC applied electric field, with the device structure affecting the mobility of the molecules as they pass through the channels. Entropic traps have other uses in manipulating and collecting many molecules, with a high degree of control, into a narrow band, which is useful in the separation process. Although the invention has been disclosed in terms of preferred embodiments, it will be apparent that variations and modifications may be made without departing from the true spirit and scope thereof as set forth in the following claims.
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Nanofluidic entropic traps, comprising alternating thin and thick regions, sieve small molecules such as DNA or protein polymers and other molecules. The thick region is comparable or substantially larger than the molecule to be separated, while the thin region is substantially smaller than the size of the molecules to be separated. Due to the molecular size dependence of the entropic trapping effect, separation of molecules may be achieved. In addition, entropic traps are used to collect, trap and control many molecules in the nanofluidic channel. A fabrication method is disclosed to provide an efficient way to make nanofluidic constrictions in any fluidic devices.
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BACKGROUND OF THE INVENTION
This invention relates to quality control in manufacturing operations, and more particularly to apparatus for checking a sequence of manufactured elements for conformity to predetermined dimensional, configuration or orientation standards.
Where large numbers of similar elements such as machine parts are manufactured or otherwise processed, it is often necessary to check each successive part for conformity to some predetermined configuration along one or more dimensions of the part or to check for parts which may be misoriented relative to the others. This may variously be necessary in order to eliminate defective parts or to initiate operation of automatic machinery for correcting some detected dimensional or positional irregularity. In many instances it is unduly time consuming or costly to do this manually using simple measuring tools. Most such purely manual techniques rely upon visual tactile or other sensing operations by workmen. As a result, distractions, fatique or the like can cause occasional errors and detract from the general reliability of the checking process.
In order to provide for more rapid, efficient and reliable monitoring of manufactured parts, a variety of automatic checking devices have heretofore been developed. In general, these are undesirably complex and costly. Typically, such devices require movable mechanical sensing elements for checking dimensions or configurations of each part, as well as electrical circuits for detecting dimensional deviations on the basis of movements of the mechanical sensors. Such mechanisms are subject to wear, jamming and other malfunctions, and may be difficult to adjust.
SUMMARY OF THE INVENTION
This invention provides for detecting disconformities of any of a series of similar manufactured elements from a predetermined desired dimensional configuration or orientation, without requiring any movable mechanical sensor elements for this purpose, provided that the elements to be checked are formed of a ferromagnetic or magnetizable material such as iron, steel, nickel or the like.
The invention utilizes an electromagnetic sensing device which includes a ferromagnetic core and an electrical winding which may be energized to establish a magnetic flux path within the core. Guide means are provided for bringing the elements which are to be checked against a test surface of the core in a predetermined position thereon. One or more gaps are formed in the core at locations where a normally shaped and properly oriented element will not extend across the gaps when positioned as described above. If the element deviates from the desired configuration or orientation, it spans one or more portions of the gap in the core, thereby decreasing the reluctance of the magnetic flux path while correspondingly increasing the self-inductance of the winding.
Circuit means are provided for energizing the winding and for detecting the increase of winding inductance that occurs when a part having an undesired dimensional characteristic or orientation is positioned against the sensing device. The inductance sensing means produces a signal which may variously be caused to actuate an indicator, an alarm or automatic mechanism for rejecting or correcting the faulty part. In a preferred form, the circuit includes means for adjusting sensitivity to inductance changes, means for suppressing spurious signals which may be caused by very brief winding inductance variations, and self-contained means for monitoring the performance of internal portions of the circuit itself to facilitate adjustment and to assure reliability.
The apparatus is adaptable to checking one or more dimension or general configurational characteristics of a variety of different forms of element provided they are formed of magnetizable material, the configuration of the core and the configuration and position of the gaps in the core being modified as required for this purpose.
Accordingly, it is an object of this invention to facilitiate and simplify the checking of series of elements for conformance to a configurational or orientation standard. It is another object of the invention to provide a simple, reliable and economical means for detecting any of a sequence of similar manufactured parts which differ from a desired configuration in some dimensional characteristic or which may be misoriented relative to others in the series.
The invention, together with further objects and advantages thereof will best be understood by reference to the following description of preferred embodiments in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a perspective view of a first embodiment of the invention as adapted for determining if each of a sequence of cylindrical bushings is properly oriented by checking the internal diameter of an adjacent end of each bushing as it is progressed along a predetermined path,
FIG. 2 is a plan section view taken along line II--II of FIG. 1, and showing the internal construction of a bushing end configuration sensing device thereof and further showing a properly oriented bushing in the process of being checked,
FIG. 2A is a plan section view corresponding to FIG. 2, but illustrating conditions which exist when an improperly oriented bushing is present at the sensing device,
FIG. 3 is an electrical circuit diagram of the apparatus of FIG. 1,
FIG. 4 is a perspective view of a modification of the invention as adapted for detecting if any of a sequence of rectangular parts have end surface dimensions exceeding predetermined desired values, and
FIG. 5 is a cross-section view of the apparatus of FIG. 4, taken along lines V--V thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the invention is adaptable to checking one or more dimensions of a particular surface of a series of machine parts or other elements which are intended to be identical, and the sensing device 11 against which the elements are disposed for checking purposes may take a variety of forms according to the configuration of the particular elements which are to be checked. In the embodiment depicted in FIG. 1, the elements to be checked are cylindrical bushings 12 and the particular dimension of the bushings which is checked in this example is the diameter of the axial bore 13 through the bushings. In some cases, it may be desirable to check some dimensions such as the diameters of bushing bores 13, simply to assure that it does not exceed a predetermined manufacturing standard or in other cases, such as the present example, such checking may serve a further purpose. In the example of FIG. 1, the purpose of checking the internal diameter of one end of each bushing 12 is to assure that the successive bushings all have like ends facing in the same direction as the bushings are traveled along a particular path represented by arrow 14. Path 14 may, for example, be a path of travel of the bushings through processing machinery of any of various known kinds in which the bushings must all be oriented in the same direction. By referring momentarily to FIG. 2, it may be seen that the bushing 12 each have an internal bore 13 which is of larger diameter at one end 13a than at the other end 13b. In this example, it is desired that the bushings 12 be traveled along path 14 with the ends 13a of larger internal diameter being to the left as viewed in FIG. 1, and the checking apparatus 16 of the present invention is utilized to identify any bushing which may have accidentally been reversed so that it may be turned over to the correct orientation either manually or by automatic machinery provided for that purpose.
The sensing device 11 portion of the apparatus in this example is of cylindrical configuration in accordance with the cylindricity of the bushings to be checked, and has a circular test surface 17 at one end against which the adjacent end surface of each bushing is momentarily disposed as the bushing progresses along path 14. In being moved towards test surface 17 and then away therefrom as indicated by angled arrows 18a and 18b respectively, the bushing should be maintained in strictly coaxial relationship with the sensing device 11 at least while in the immediate vicinity thereof for reasons which will hereinafter be apparent. Such movement of the bushings may be accomplished either manually or by automatic mechanism provided for that purpose.
Each bushing to be checked must be briefly disposed against test surface 17 of the sensing device 11 in a precise predetermined positional relationship therewith which in the present example is a coaxial relationship. Guide means 19 are provided to assure that this relationship is established. In the present example, the guide means 19 is a block 21, having a slot 22 of V-shaped cross section, and having the sensing device 11 mounted at one end with the test surface 17 facing the end of the slot. Slot 22 is proportioned to support each bushing 12 in the desired coaxial relationship with test surface 17. A multi-conductor electrical cable 23 connects sensing device 11 with an electric console 24 containing power supply and detection circuits which will hereinafter be described.
Referring now again to FIG. 2, sensing device 11 has a core 26 formed of iron or other ferromagnetic material, the core having a cylindrical outer portion 27 which may be intregal with a circular end portion 28 and further has a rod like center portion 29 extending from end portion 28 along the axis of the device to terminate at a flange portion 31 which, together with the adjacent end of the cylinder portion 26 forms the test surface 17 against which the bushings 12 are momentarily positioned. Flange portion 31 has a diameter slightly greater than the internal diameter of end 13b of the bushings and the internal diameter of cylindrical portion 26 of the core is slightly smaller than the internal diameter of the other end 13a of the bushings while being greater than that of the flanged portion 31. Thus an annular gap 32 is present in the core at end surface 17 of the test device, the gap having inside and outside diameters intermediate between the inside diameters of the two ends of the bushing.
To establish a magnetic flux within the core 26, an annular winding or coil 33 is disposed coaxially around the rod portion 29 of the core within the cylinder portion 26 and has a pair of electrical leads 34a and 34b extending out of the core through cable 23.
Thus upon electrical energization of the winding 33, a closed magnetic flux path is established within the core 26 which, as indicated by flux lines 36, extends along rod portion 29 of the core, then radially outward within end portion 28, then in an opposite direction along the cylindrical outer portion 26 of the core, and then radially inward across gap 32 and then back to the rod portion through flange portion 31.
In the absence of a bushing 12, the core 26 will exhibit a magnetic reluctance value determined by the proportions of the core and the characteristics of the material of which it is formed. As the winding 33 is inductively coupled to the core, the self-inductance of the winding will in turn have some fixed value. The self-inductance of such a winding is an inverse function of the reluctance of the assoicated core. Thus, if the reluctance of the core should be decreased, for example by the presence of magnetic material spanning the gap 32, then the self-inductance of the winding will exhibit an increase. This characteristic of the core and winding combination is relied upon to determine which end of each bushing 12 is adjacent test surface 17 of the core.
If, as illustrated in FIG. 2, the bushing end 13a of large diameter is adjacent test surface 17, core gap 32 is not spanned by ferromagnetic material and the presence of the bushing does not have a significant effect on the reluctance of the core. But if the bushing 12 should be inverted end to end as illustrated in FIG. 2A, then gap 32 of the core 26 is spanned by ferromagnetic material and the reluctance of the core decreases substantially. The self-inductance of winding 33 is correspondingly increased under the condition depicted in FIG. 2A, and circuit means to be hereinafter described detects this increase in self-inductance to produce a signal indicative of the inversion of the bushing 12.
Considering now a suitable construction for the circuit means, reference should be made to FIG. 3. Electrically, the sensing device 11 including winding 33 and core 26 is essentially a variable inductance which has one inductance value in the absence of a bushing or when an adjacent bushing is properly oriented but which exhibits a higher inductance value when an improperly oriented bushing is present. To detect this inductance change, winding 33 is connected through leads 34a and 34b to form one of the four legs of a bridge circuit 37.
Bridge circuit 37 had a first terminal 38 to which coil lead 34b connects and which is grounded, a second terminal 39 to which the other coil lead 34a connects, and has third and fourth terminals 41 and 42. To energize the bridge, terminals 39 and 42 are connected to opposite ends of a first secondary winding 43 of a power transformer 44. A resistor 46 is connected between terminals 39 and 41, another resistor 47 is connected between terminals 38 and 42, while an additional and variable resistor 48 is connected between terminals 41 and 42 in parallel with a adjustable capacitor 49. Resistors 46, 47 and 48 are selected to have resistance values equivalent to the impedance value which winding 33 exhibits in the absence of a bushing at the sensing device 11. Thus, in the absence of a bushing, the bridge 37 is balanced and no significant voltage difference is present between terminals 38 and 41 of the bridge. Resistor 48 is variable in order that adjustments may be made to assure balance under this condition, and the adjustable capacitance 49 provides for phase compensation adjustment. If an improperly oriented bushing should be disposed at sensing device 11 as previously described, the inductance increase at winding 33 is accompanied by a corresponding impedance increase. This unbalances the bridge 37, and causes a voltage difference to appear between terminals 38 and 41.
Power transformer 44 may have a primary winding 51 connected to any suitable source 52 of alternating current. In order to provide a regulated direct current for other components of the circuit to be hereinafter described, the transformer may have an additional secondary winding 53 connected to a rectifier which in this instance is a diode bridge circuit 54. Bridge 54 has input terminals 56 and 57 to which opposite ends of secondary winding 53 connect, and has output terminals 58 and 59, terminal 58 being grounded and terminal 59 being coupled to a DC supply conductor 61 through a resistor 62. Four diodes 63 complete the bridge 54, each diode being connected between a separate pair of the terminals 56, 57, 58 and 59 with terminal 59 being connected to the positive sides of the two adjacent diodes 63 while terminal 58 connects to the negative sides of the other two diodes. A capacitor 64 is connected between terminal 59 and ground to smoooth the output waveform, and a zener diode 66 is connected between DC supply conductor 61 and ground to maintain a constant voltage thereon.
As pointed out above, the appearance of an AC voltage at terminal 41 of bridge 37 is indicative of the detection of a misoriented bushing. This voltage is detected and caused to produce an output signal by closing a set of normally open output relay contacts 67, which in this example are connected between DC supply conductor 61 and ground through a resistor 68 and also through an indicator lamp 69 which is connected in parallel with the resistor 68. Thus lamp 69 is energized by closing of relay contacts 67 to give a visual indication of the detection of a misoriented bushing. It will be apparent that other indicator means such as audible alarms may be substituted for the indicator lamp 69. Further, upon closing of the relay contact 67, a signal voltage appears at a terminal 71 between the relay contacts and resistor 68. The signal may be utilized to actuate suitable automatic bushing position correcting mechanisms or for other purposes as desired.
Considering now suitable circuitry for operating the output relay contacts 67 in response to the appearance of an AC voltage at bridge terminal 41, such terminal is connected to the base of an amplifying transistor 72 through a coupling capacitor 73. The base and emitter of transistor 72 are connected to ground through resistors 74 and 76 respectively and bias voltage is supplied to the base of transistor 72 through another resistor 77 which connects to DC supply conductor 61. Still another resistor 78 is connected between the DC supply conductor and the collector of transistor 72. Thus the appearance of an AC voltage at bridge terminal 41 results in an amplified AC waveform appearing at the collector of transistor 72. The collector of the transistor is coupled to a terminal 79 through a capacitor 80 and a diode 75. Another inverted diode 82 is connected between ground and the anode of diode 75. Thus diodes 75 and 82 rectify the AC waveform to apply a DC voltage to terminal 79 in response to the AC voltage at bridge terminal 41. This DC voltage is applied to the inverting input of an operational amplifier 81 through another diode 85 and an input resistor 83. A resistor 84 and capacitor 86 are connected between terminal 79 and ground to complete the rectifying action of diodes 75 and 82 by smoothing ripple in the DC signal applied to terminal 79.
Operational amplifier 81 is connected to operate in the Schmitt trigger mode, and for this purpose may have a power supply circuit connected between DC supply conductor 61 and ground, a compensating resistor 87 connected between the output and the non-inverting input with the non-inverting input being connected to ground through a resistor 88, the movable tap of a potentiometer 89 and another resistor 91. The other end of the resistive element of potentionmeter 89 is connected to DC supply conductor 61. Thus potentiometer 89 enables adjustment of the trigger threshold of the Schmitt trigger circuit formed by amplifier 81.
Accordingly, when the DC voltage applied to the inverting input of amplifier 81 reaches a predetermined level as determined by the setting of potentiometer 89, a trigger action occurs and a voltage appears at the output of the amplifier 81 which output voltage remains until the signal at the amplifier input drops to a substantially lower level in accordance with the Schmitt trigger action. This output voltage from amplifier 81 is caused to energize a driver coil 93 which closes output relay contacts 67 as previously described. Impedance matching is provided for by connecting one end of driver coil 93 to ground and by connecting the other end to DC supply conductor 61 through the emitter-collector circuit of another transistor 94. Transistor 94 has a base connected to the output of amplifier 81 through a resistor 96. A diode 97 may be connected between the ends of driver coil 93 to supress any inverted transient voltage spikes which might occur.
To prevent production of spurious output signals in response to very brief voltage rises at bridge terminal 41 such as might occur from accidental movement of a properly oriented bushing or form some other cause, a time delay circuit is provided between terminal 79 and amplifier 81 to delay triggering of the amplifier until an incoming signal has continued for a predetermined time. For this purpose a capacitor 98 may be connected between ground and the junction between diode 85 and amplifier input resistor 83, while a potentiometer 99 is connected in parallel with diode 85. Thus a DC signal appearing at terminal 79 is not transmitted on to trigger amplifier 81 until such time as capacitor 98 has charged up a voltage level required for this purpose. If the duration of the signal is less than that which can be relied upon as indicative of a misoriented bushing, the partial charge of capacitor 98 will gradually discharge through potentiometer 99 and resistor 84 without triggering the amplifier. Potentiometer 99 provides for adjustment of the signal duration required for triggering the amplifier. It should also be noted that capacitor 98 assures that once the amplifier is triggered it will remain in this condition for a predetermined period of time as the voltage accumulated on the capacitor 98 must leak away through potentiometer 99 and resistor 84 to a low level before the Schmitt trigger connected amplifier 81 reverts to the original condition. Misoriented bushing signals of undesirably brief duration are thereby prevented.
Accordingly, the circuit described above provides an output signal, produced by closing of relay contact 67, in response to a change of self-inductance of winding 33 of more than a predetermined magnitude and duration, this self-inductance change being indicative of a misoriented bushing as previously described. Means have also been described for making various sensitivity and threshold adjustments in the circuit to optimize performance and to adapt to different operating conditions. Such adjustments may be facilitated if built-in means are provided for measuring the voltages present at certain key points in the circuit. A voltmeter 101 may be provided in the circuit for this purpose. Switch means 102 are provided for selectively connecting the voltmeter between any selected one of four pairs of contacts A, B, C and D. The first set of contacts A are unconnected to other portions of the circuit and simply define an Off position for the voltmeter 101. Operation of the switch means 102 to connect the voltmeter between terminals B enables measurement of the AC output signal of amplifier transistor 72 which in turn facilitates adjustment of the bridge 37 by means of potentiometer 48 and variable capacitor 49 for the purpose of eliminating any significant voltage signal at bridge terminal 41 in the absence of a misoriented bushing at sensing device 11. For this purpose, one contact B connects to one output terminal of another diode bridge rectifier circuit 103 which may be similar to the bridge 54 previously described, while the other contact B connects to the other output terminal of bridge 103 through a current limiting resistor 104. One input of bridge 103 is grounded while the other input connects to the collector of amplifier transistor 72 through a coupling capacitor 106. To complete the rectifying action, a smoothing capacitor 107 is connected across the output terminals of bridge 103. Bridge 103 in conjunction with capacitor 107 thus rectifies the AC voltage present at the collector of amplifier transistor 72 and applies such rectified voltage to contacts B for measurement by voltmeter 101.
One of a third set of contacts C is grounded while the other contact C connects to terminal 79 through a current limiting resistor 108 to enable checking of the rectified signal magnitude which is applied to time delay capacitor 98 through diode 85 and to the amplifier 81. The final set of contacts D provide for measurement of the threshold voltage which must be applied across the inputs of amplifier 81 to trigger the amplifier. This facilitates use of potentiometer 89 to make adjustments in the threshold voltage if needed. For this purpose, one of the contacts D is connected to the non-inverting input of amplifier 81 through resistor 88. The other of the contacts D is connected to the source terminal of a field effect transistor 92 through a resistor 109 and that transistor terminal is also grounded through a resistor 111. The drain terminal of transistor 92 is connected to DC power conductor 61 while the gate of the transistor 92 is connected to the junction between amplifier input resistor 83 and diode 85 through another resistor 112. The result of including the field effect transistor 92 in the contact D circuit is to create a virtually infinite input imepedance to prevent the voltage undergoing measurement from being altered by interference effects.
The example of the invention described above with reference to FIGS. 1 to 3 is particularly adapted for detecting any end to end misorientation of bushings in a progression of such bushings, and accomplishes this by checking the inside diameter of one end of each bushing. It will be apparent that the apparatus is not limited to this particular usage but may be modified to perform any of a large number of parts monitoring operations. In general, the invention may be adapted to detect any one of a progression of elements which deviates from a predetermined dimensional configuration at some accessible surface. The variations in the test surface of the sensing device which may be provided for this purpose are as numerous as the variations in the shape of diverse manufactured parts and for purposes of illustration, an additional example of a sensing device 11', suitable for a different purpose, is illustrated in FIGS. 4 and 5.
The sensing device 11' of FIGS. 4 and 5 is adapted to determine if any of a series of rectangular block shaped ferromagnetic objects 12' have an end surface which exceeds a predetermined dimension in either direction (a) or in the right angled direction (b) or in both directions. Accordingly, the test surface 17' against which the blocks 12' are temporarily disposed for monitoring has a rectangular first portion 113 with dimensions conforming dimensions (a) and (b) of the block 12' and has an angled outer portion 114 which extends along two sides of portion 113 but which is separated therefrom by a small gap 32'. The two portions of the test surface 17' are connected, beneath test surface 17', by a U-shaped yoke portion 117 having a winding 33' coupled thereto to establish a magnetic flux path within the core 26'. The lead wires 34a' and 34b' from winding 33' may connect with a detection circuit similar to that previously described with respect to the first embodiment of the invention. To position successive ones of the block-shaped objects 12' on test surface 17', an angled upwardly extending guide 19', preferably formed of non-magnetic material such as plastic, is secured to the core 26' at one corner of portion 113.
Thus the previously described circuit will produce no output signal as long as each block 12' which is positioned on test surface 17' does not extend at least partly across the gap 32' in either direction (a) or (b). If a wrongly dimensioned block 12' should extend across the gap 32' in one direction or both, the reluctance of core 26' is increased and the self-inductance of winding 33' is corresponding decreased to trigger the associated detection circuit as previously described.
The gap 32' is shown as being fairly broad in FIGS. 4 and 5 for clarity of illustration, but can in practice be made considerably narrower in order to detect slight deviation of the objects 12' from predetermined dimensions. While the examples of the invention herein described function to detect an oversized condition of an outside measurement of objects or an undersized condition of an inside diameter of objects, the invention may also be adapted to monitor for the opposite conditions. For example, if the gap 32' in the sensing device 19' of FIGS. 4 and 5 is proportioned to be just covered by a normal sized object 12', then an undersized object will not span the gap. In that case, with reference to FIG. 3, the presence of an undersized object is indicated by a failure of relay contacts 67 to close while the object is positioned on the test surface.
Accordingly, many modifications of the apparatus are possible, and it is not intended to limit the invention except as defined in the following claims.
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One or more dimensions of each of a series of similar manufactured elements, which are formed of magnetizable materials such as iron, steel, nickel or the like may be quickly checked for conformity to a predetermined value by momentarily positioning each successive element against an electromagnetic sensing device. The sensing device has a winding establishing a magnetic flux path through a core which is formed with one or more gaps in the magnetic circuit that are located to be spanned by a wrongly dimensioned or wrongly oriented one of the manufactured elements. Spanning of a flux gap of the core by a wrongly dimensioned or misoriented element changes the self-inductance value of the winding, and circuit means are provided for detecting such change in order to indicate the presence of a disconforming element or to actuate mechanism for rejecting or correcting the element.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a heat dissipation device, and more particularly to a heat dissipation device having a heat sink and a fan holder for facilitating mounting of a fan on the heat sink.
[0003] 2. Description of Related Art
[0004] Generally, in order to ensure the normal running of an electronic device, a heat dissipation device is used to dissipate heat generated by the electronic device. A conventional heat dissipation device includes a heat sink and a fan attached on the heat sink to improve a heat-dissipation capacity of the heat sink.
[0005] When installing the fan to the heat sink, it is generally to fix the fan to a side of the heat sink via a fan holder with screws. Although using the screws can achieve the fastening objective, it requires a lot of manpower and material resource. Furthermore, it is necessary to remove the fan first by unscrewing the screws when disassembling and maintaining the heat dissipation device. Such unscrewing operation is tiresome for a user. In addition, it is also possible that the unscrewed screws may fall into a computer in which the heat dissipation device is mounted to cause damages to components of the computer.
[0006] What is need therefore is a heat dissipation device having a design which makes assembling and disassembling of a fan to/from a heat sink of the heat dissipation device be convenient and easy.
SUMMARY OF THE INVENTION
[0007] The present invention relates to a heat dissipation device for dissipating heat generated by a heat-generating electronic component. The heat dissipation device includes a heat sink, a fan for providing airflow through the heat sink and a fan holder coupling the fan to the heat sink. The heat sink has a first locking part and a second locking part opposite to the first locking part of the heat sink. The fan holder has a first engaging part engaging with the first locking part at one side of the heat sink and a second engaging part engaging with the second locking part at an opposite side of the heat sink.
[0008] Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiment when taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Many aspects of the present device can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0010] FIG. 1 is an assembled view of a heat dissipation device in accordance with a preferred embodiment of the present invention;
[0011] FIG. 2 is an exploded, isometric view of FIG. 1 ;
[0012] FIG. 3 is an exploded, isometric view of a heat sink of the heat dissipation device of FIG. 2 ;
[0013] FIG. 4 is an inverted view of a fan holder of the heat dissipation device of FIG. 2 ; and
[0014] FIG. 5 is an assembled view of the fan holder with a fan of the heat dissipation device of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0015] Referring to FIGS. 1-3 , a heat dissipation device in accordance with a preferred embodiment of the present invention is shown. The heat dissipation device is used to be mounted to two heat-generating electronic elements (not shown), to dissipate heat therefrom. The heat dissipation device comprises a heat sink, a fan holder 50 secured at a front side of the heat sink and a fan 60 attached to the fan holder 50 .
[0016] The heat sink comprises a base 10 , a fin set 30 located on the base 10 , a heat pipe assembly 20 thermally connecting the base 10 and the fin set 30 and a fin cover 40 covering top and two opposite lateral sides of the fin set 30 .
[0017] The base 10 comprises a supporting frame 13 and two plates 11 attached to a bottom of the supporting frame 13 for contacting with the two corresponding heat-generating electronic elements. Each of the plates 11 is made of good conductive material such as copper, and is rectangular in shape and defines three parallel receiving grooves 110 in a top surface thereof. The supporting frame 13 comprises two spaced and parallel shoulders 132 and two spaced and parallel bridges 134 connecting the two shoulders 132 together. The bridges 134 are perpendicular to the shoulders 132 . The supporting frame 13 is provided with a first locking part for engaging with the fan holder 50 . In this embodiment, the first locking part is two fixing slots 1320 parallel to the shoulders 132 . The two fixing slots 1320 are defined in two joints of the two bridges 134 with one of the shoulders 132 for engaging with the fan holder 50 . A plurality of countersinks 1322 are defined in the shoulders 132 , adjacent to two remote edges thereof, for receiving fixtures (not labeled) to attach the heat sink onto the heat-generating electronic elements. The two shoulders 132 are respectively provided with two step portions 1324 that face to each other, for receiving the plates 11 under the frame 13 . Each of the shoulder 132 defines two mounting orifices 1326 in two opposite lateral ends thereof, for engaging with screws 100 to secure the fin cover 40 to the base 10 . The two bridges 134 define a rectangular opening 130 therebetween. Two cutoffs (not labeled) are defined beside the bridges 134 , respectively, and between the shoulders 132 . Each of the bridges 134 defines three parallel receiving grooves 1340 in a bottom surface thereof corresponding to the receiving grooves 110 of the plates 11 .
[0018] The heat pipe assembly 20 includes two groups of heat pipe, each having three heat pipes 21 . Each of the heat pipes 21 is U-shaped in profile and comprises an evaporating section 217 , two parallel condensing sections 214 perpendicular to the evaporating section 217 and two curved connecting sections (not labeled) extending from two opposite ends of the evaporating section 217 and connecting the evaporating section 217 with corresponding condensing sections 214 .
[0019] The fin set 30 comprises a plurality of fins 32 and defines four spaced and parallel rows of receiving holes 34 for receiving the condensing sections 214 of the heat pipes 21 . Two rows of the receiving holes 34 are defined in a middle portion of the fin set 30 , and the other two rows of the receiving holes 34 are defined in two lateral portions of the fin set 3 , respectively. Each row of the receiving holes 34 includes three receiving holes 34 vertically extending through the fin set 30 . Each fin 32 is made of a rectangular metallic plate.
[0020] The fin cover 40 is integrally made of a piece of metal sheet and comprises a rectangular top panel 42 and two sidewalls 44 extending perpendicularly and downwardly from two lateral opposite edges of the top panel 42 . The top panel 42 is provided with a second locking part at a middle portion thereof, for securing the fan holder 50 to the fin cover 40 . In this embodiment, the second locking part is a connecting sheet 422 recessing from a top surface of the top panel 42 . The connecting sheet 422 defines a locking orifice 4220 therein, for engaging with the fan holder 50 . Due to the recessing of the connecting sheet 422 , the top panel 42 forms a concave portion in a middle thereof. The connecting sheet 422 has a width less than that of other portion of the top panel 42 . The two sidewalls 44 are constructed to be disposed snugly on the two opposite lateral sides of the fin set 30 . The two sidewalls 44 each have a width increasing gradually in a same direction from a top to a bottom thereof. A bottom end of each of the sidewalls 44 is bent inwardly and perpendicularly, then further downwardly and perpendicularly to form a mounting leg 442 . Each of the mounting legs 442 defines two fixing orifices 4420 adjacent to two opposite ends thereof, for allowing the screws 100 to extend therethrough to screw into the mounting orifices 1326 of the base 10 .
[0021] Particularly referring to FIG. 2 , in assembly of the heat sink, the evaporating sections 217 of two groups of the heat pipes 21 are sandwiched between the two respective plates 11 and the two corresponding bridges 134 of the supporting frame 13 and received respectively in channels formed cooperatively by the receiving grooves 110 , 1340 of the two plates 11 and the bridges 134 of the supporting frame 13 ; the condensing sections 214 of two groups of the heat pipes 21 are engagingly received in the receiving holes 34 of the fin set 30 , respectively; thus, the base 10 and fin set 30 are thermally connected together by the heat pipes 21 . The fin cover 40 covers on the fin set 30 and is secured to the base 10 by the screws 100 extending through the corresponding fixing orifices 4420 of the mounting legs 442 of the sidewalls 44 to screw into the mounting orifices 1326 of the base 10 .
[0022] It can be easily understood in some embodiment, the fin cover 40 can be omitted. Correspondingly, a top fin 32 of the fin set 30 defines a locking orifice replacing the locking orifice 4220 of the fin cover 40 to engage with the fan holder 50 .
[0023] As shown in FIG. 4 , the fan holder 50 is formed by molded plastic material and substantially ring-shaped. The fan holder 50 has a ring body 51 with a through hole 52 therein for allowing air flow generated by the fan 60 to pass through the fan holder 50 . The ring body 51 defines a plurality of engaging orifices 510 therein for engaging with corresponding fixtures 200 to attach the fan 60 onto the fan holder 50 . The fan holder 50 is provided with a first engaging part at an upper edge of the ring body 51 and a second engaging part at a lower edge of the ring body 51 opposite to the upper edge. In this embodiment, the first engaging part is a fixing arm 54 that extends perpendicularly and rearwards from a top of the ring body 51 . The fixing arm 54 has a barb 540 extending downwardly form a middle of a bottom surface thereof and matching with the locking orifice 4220 of the fin cover 40 . The second engaging part is two inhibiting tabs 56 protruding downwardly from a bottom of the ring body 51 for engaging into the fixing slots 1320 of the base 10 .
[0024] The fan 60 has a frame (not labeled) with a shape and size corresponding to that of the fan holder 50 . The frame defines a plurality of through orifices 62 ( FIG. 2 ) corresponding to the engaging orifices 510 of the fan holder 50 , for receiving the fixtures 200 .
[0025] In assembly of the heat dissipation device, the fan holder 50 and the fan 60 are assembled into a fan assembly by the fixtures 200 extending through the through orifices 62 of the fan 60 to engage into the engaging orifices 510 of the fan holder 50 . The fixing arm 54 of the fan holder 50 of the fan assembly is disposed in the concave portion of the fin cover 40 and supported by the connecting sheet 422 of the fin cover 40 with the barb 540 of the fixing arm 54 aligned with the locking orifice 4220 of the fin cover 40 . The fan holder 50 of the fan assembly is then pressed downwardly to force the barb 540 of the fixing arm 54 to be interferentially fitted into the locking orifice 4220 of the fin cover 40 . As soon as the barb 540 of the fixing arm 54 fits in the locking orifice 4220 of the fin cover 40 , the barb 540 hooks with the connecting sheet 422 of the fin cover 40 . When the barb 540 is engaged into the locking orifice 4220 of the fin cover 40 , the two inhibiting tabs 56 at the bottom of the fan holder 50 of the fan assembly are forced to be engagingly inserted into the two corresponding fixing slots 1320 of the frame 13 of the base 10 . The fan 60 combined with the fan holder 50 is thus mounted to the heat sink securely and easily. To detach the fan assembly from the heat sink, a user only needs to pull the fixing arm 54 upwardly by hand to release the hooked connection between the barb 540 and the connecting sheet 422 ; then the fan assembly can be pulled away from the heat sink easily.
[0026] According to aforementioned description, assembling and disassembling of the fan assembly consisting of the fan 60 and the fan holder 50 to/from the heat sink can be easily and simply completed by the user using his (her) hands, without requiring any special tool to rotate a plurality of screws.
[0027] It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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A heat dissipation device for at least a heat-generating electronic component includes a heat sink, a fan for providing an airflow through the heat sink and a fan holder coupling the fan to the heat sink. The heat sink has a first locking part and a second locking part opposite to the first locking part. The fan holder has a first engaging part engaging with the first locking part at one side of the heat sink and a second engaging part engaging with the second locking part of the heat sink at an opposite side thereof. The first engaging part has a horizontally extending fixing arm and a barb extending downwardly from the fixing arm and hooking with a top side of the heat sink.
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[0001] This is a continuation-in-part (CIP) of U.S. patent application Ser. No. 09/674,700, filed Nov. 6, 2000, now U.S. Pat. No. 6,470,690, and U.S. patent application Ser. No. 10/108,450, filed Mar. 29, 2002.
FIELD AND BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method and a system for supplying pressurized gas from a liquefied-gas (LG) storage tank.
[0003] LG systems are widely used in residential, agricultural, and industrial settings and they are expected to be a reliable source of energy, to operate safely, continuously, and to constantly supply guaranteed output. One critical performance criterion of LG systems is the delivery of a constant, stable and reliable flow of vaporized gas to the burners.
[0004] Some commonly used systems and methods of vaporization employ over-capacity storage tanks and vaporizers. The over-capacity storage tanks are expensive and provide inconsistent vapor pressure, especially during extreme ambient conditions. They also waste space, call for surplus gas stock and unnecessarily large and expensive storage area.
[0005] In one known system, the heat of vaporization is supplied by convection with respect to the ambient heat. However, this requires large heat-convection surfaces, according to the demand for the vaporized gas. Moreover, such systems are incapable of delivering gas at pressures exceeding that of the tank pressure.
[0006] In another known system, an external vaporizer is used to heat and vaporize the liquefied gas, with the vaporized gas being recirculated to the storage tank. The vaporized gas supplied to the consumer is delivered via a separate line connected to the storage tank, according to consumer demand. The recirculation of vaporized gas requires a large installation, and correspondingly high investment cost and maintenance expenses. Alternatively, the vaporized gas can be delivered directly to the consumer. However, various mechanical and control-related failures, as well as reduced consumer demand, can cause liquid-phase liquefied gas to be introduced to or to be condensed in the consumer delivery line. Liquid-phase liquefied gas in the vaporized gas is a major problem for many consumers. Consequently, such a process scheme generally requires the addition of vapor/liquid separation equipment for providing the consumer with solely vaporized gas. This equipment increases system complexity, size and cost, and introduces additional reliability and safety problems.
[0007] In the parent application, now U.S. Pat. No. 6,470,690, which is hereby incorporated for all purposes as if fully set forth herein, a system and method are disclosed in which the liquefied gas is circulated through an external heat exchanger and returned to the storage tank as a heated liquid. The sensible heat of the heated liquefied gas provides all of the requisite heat for vaporizing the gas (or at least a substantial portion thereof), which occurs within the storage tank. The vaporized gas is delivered via a separate vapor line connected to the storage tank, according to consumer demand.
[0008] The above-described system has numerous advantages with respect to other known systems. One important advantage is that the system enables major electrical components to be located remotely from the storage tank. This safety advantage is of particular importance due to the flammable nature of the gases disposed within and delivered from the storage tank.
[0009] In some applications, however, it is impractical to install an external heat exchanger through which liquefied gas is pumped.
[0010] It would, therefore, be highly advantageous to have a method and a system for supplying vaporized gas on consumer demand without a circulation of liquefied gas external to the storage tank, and without the requisite equipment therefor. It would be of further advantage if the system would allow for improved fire safety with respect to prior-art systems, by enabling all electrical components to be located remotely from the storage tank. It would be of yet further advantage if such a system would be simple and energy-efficient.
SUMMARY OF THE INVENTION
[0011] The present invention is a method and a system for supplying pressurized gas from a liquefied-gas (LG) storage tank.
[0012] According to one aspect of the invention, the method includes the steps of: (a) providing a system including: (i) a storage tank for storing liquefied gas, the tank having a lower liquid region and a vapor region thereover; (ii) a heat exchanger external to the storage tank, disposed in a heat-exchange relationship with a wall of the storage tank; (iii) a device for delivering a heat-exchange liquid from a reservoir to the heat exchanger, and (iv) a, delivery line for directly transferring the combustible vaporized gas from the heat exchanger to the consumer; (b) supplying the vaporized gas directly to the consumer, according to consumer demand; (c) upon vaporization of a portion of the liquefied gas within the storage tank, and subsequent cooling of the liquefied gas within the storage tank, transferring heat from the heat-exchange liquid to the storage tank by means of the heat exchanger, so as to increase the pressure within the storage tank.
[0013] According to further features in the described preferred embodiments, the method further includes the step of (d) heating the reservoir to supply the heat-exchange liquid with the requisite heat for transferring to the storage tank.
[0014] According to still further features in the described preferred embodiments, the method further includes the step of: (e) circulating the heat-exchange liquid between the reservoir and the heat exchanger.
[0015] According to still further features in the described preferred embodiments, the system further includes a first line for delivering the heat-exchange liquid to the heat exchanger, and a second line for returning the heat-exchange liquid from the heat exchanger to the reservoir.
[0016] According to still further features in the described preferred embodiments, the method further includes the step of: (f) measuring a temperature of the heat-exchange liquid in'the second line, to obtain a measured temperature.
[0017] According to still further features in the described preferred embodiments, the method further includes the step of: (g) heating the reservoir based on the measured temperature of the heat-exchange liquid in the second line.
[0018] According to still further features in the described preferred embodiments, the method further includes the step of: (g) controlling the device for delivering the heat-exchange liquid based on the measured temperature of the heat-exchange liquid in the second line.
[0019] According to still further features in the described preferred embodiments, the method further includes the step of: (f) measuring a pressure within the delivery line to obtain a vapor pressure measurement.
[0020] According to still further features in the described preferred embodiments, the method further includes the step of: (g) controlling the transfer of heat from the heat-exchange liquid to the storage tank based on the vapor pressure measurement.
[0021] According to another aspect of the present invention there is provided a gas supply system for supplying a combustible vaporized gas to a consumer, according to consumer demand, the gas supply system including: (a) a storage tank for storing liquefied gas, having a lower liquid region and a vapor region thereover; (b) a heating system for providing heat to the storage tank, including: (i) a heat exchanger external to the storage tank, the heat exchanger disposed in a heat-exchange relationship with a wall of the storage tank; (ii) a reservoir for storing a heat-exchange liquid for the heat exchanger; (iii) a first line connecting the reservoir and the heat exchanger, and a second line for returning the heat-exchange liquid from the heat exchanger to the reservoir, and (iv) a pumping device for delivering the heat-exchange liquid from the reservoir to the heat exchanger, via the first line; (c) a delivery line for transferring the vaporized gas from the storage tank to the consumer, and (d) a control system associated with the heating system and configured to control a heat supply to the storage tank, by means of the heat-exchange liquid, such that the storage tank produces the vaporized gas at sufficient pressure so as to meet the consumer demand.
[0022] According to further features in the described preferred embodiments, the control system includes a temperature sensor for measuring a temperature of the heat-exchange liquid returning to the reservoir.
[0023] According to still further features in the described preferred embodiments, the heating system includes a heating element for heating the reservoir.
[0024] According to still further features in the described preferred embodiments, the control system effects the control by operating the heating element based on the temperature measured by the sensor.
[0025] According to still further features in the described preferred embodiments, all electrical components of the gas supply system are disposed remotely to the storage tank. Preferably, the electrical components should be at least 5 meters from the gas supply system, more preferably, 10-25 meters, and most preferably, more than 25 meters from the gas supply system.
[0026] According to still further features in the described preferred embodiments, the delivery line has a pressure sensor for measuring a vapor pressure of the vaporized gas in the delivery line.
[0027] According to still further features in the described preferred embodiments, the control system controls the heating system based on the vapor pressure measured by the pressure sensor.
[0028] According to still further features in the described preferred embodiments, if the vapor pressure measured by the sensor exceeds a pre-determined value, the control system reduces or completely curtails the heat supply to the storage tank.
[0029] According to still further features in the described preferred embodiments, if the vapor pressure measured by the sensor exceeds a pre-determined value, the control system controls the pumping device so as to reduce or completely curtail the heat supply to the storage tank.
[0030] According to still further features in the described preferred embodiments, the heat exchanger includes a flexible heat transfer plate for disposing against an external wall of the storage tank.
[0031] According to still further features in the described preferred embodiments, the heat exchanger further includes a pipe containing the heat-exchange liquid, the pipe being fluidly connected to the first line, and disposed in heat-exchange relation to the flexible heat transfer plate.
[0032] According to still further features in the described preferred embodiments, the heat transfer plate is a corrugated heat transfer plate.
[0033] According to still further features in the described preferred embodiments, the heat-exchange liquid includes water.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The invention is herein described, by way of example only, with reference to the accompanying drawings. 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 than 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.
[0035] In the drawings:
[0036] [0036]FIG. 1 is a block diagram illustrating a system for supplying vaporized gas according to the parent application, U.S. Pat. No. 6,470,690, and
[0037] [0037]FIG. 2 is a schematic diagram illustrating one embodiment of a system for supplying vaporized gas according to the present invention;
[0038] [0038]FIG. 3 a is a top, schematic, partially cut-away view of a heating blanket for use in conjunction with the system of the present invention, and
[0039] [0039]FIG. 3 b is a side view of the heating blanket of FIG. 3 a.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] The principles and operation of the system in the invention according to the present invention may be better understood with reference to the drawings and the accompanying description.
[0041] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawing. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
[0042] As used herein in the specification and in the claims section that follows, the term “liquid” refers to a non-explosive and, preferably, a non-inflammable liquid.
[0043] Referring now to the drawings, FIG. 1 is a block diagram illustrating a vaporization system 10 for vaporizing gas according to the parent application, U.S. patent application Ser. No. 09/674,700, now U.S. Pat. No. 6,470,690. A storage tank 20 contains gas, such as propane or butane, in liquefied form, in a lower region 22 . Upper region 23 , which is in fluid contact with lower region 22 , contains gas in vapor form. Liquefied gas from lower region 22 is circulated, preferably by a water-driven turbine pump 40 , through a heat exchanger 50 . The liquefied gas is heated in heat exchanger 50 , the heating being controlled such that the liquefied gas is returned in liquid form to storage tank 20 . The sensible heat of the heated liquefied gas provides all of the requisite heat for vaporizing the gas, or at least a substantial portion thereof. The vaporized gas, produced in storage tank 20 , is delivered to a consumer 100 , according to demand, via a separate vapor line 70 connected to storage tank 20 .
[0044] Heat exchanger 50 is a surface heat exchanger typically using water as the heat exchange liquid. The water, which is heated and pressurized externally to vaporization system 10 , is introduced to heat exchanger 50 via line 36 . The water exiting heat exchanger 50 can also serve to drive water-driven turbine pump 40 , before leaving system 10 via line 32 .
[0045] The above-described system has numerous advantages with respect to other known systems. One important advantage is that the system enables major electrical components to be located remotely from the storage tank. This safety advantage is of particular importance due to the flammable nature of the gases disposed within and delivered from the storage tank.
[0046] In some applications, however, it is impractical to install an external heat exchanger through which liquefied gas is pumped. Hence, it would be advantageous to have a system for supplying vaporized gas on consumer demand without a circulation of liquefied gas external to the storage tank, and without the requisite equipment therefor. It would be of further advantage if the system would allow for improved fire safety with respect to prior-art systems, by enabling all electrical components, including electrical actuators and indicators, to be located remotely from the storage tank.
[0047] [0047]FIG. 2 illustrates a storage tank 2 that is heated by a heating system 100 of the present invention, which includes a remote water heater 51 , a heating blanket 50 , a circulation pump 52 , temperature indicator 55 , and optionally, CPU 60 . Heating blanket 50 , which is directly applied to the external surface of the storage tank, is heated by hot water circulated to heating blanket 50 via a circulation pump 52 . A remote water heater 51 , typically gas-fired or electric, heats the circulated water to heating blanket 50 .
[0048] Heating blanket 50 may be disposed substantially anywhere on the body of storage tank 2 . However, it is generally preferable to position heating blanket 50 towards the bottom of storage tank 2 , well below the interface between liquid region 2 a and vapor region 2 b within storage tank 2 .
[0049] Heating system 100 is designed to provide heat to storage tank 2 , so as to vaporize the requisite amount of fuel upon consumer demand. Remote water heater 51 supplies heat to the liquefied gas in storage tank 2 , along with the influx of ambient heat to boost the internal heat of the liquefied gas within, the storage tank, so as to provide the heat of vaporization for vaporizing, within the storage tank, the liquefied gas, according to the consumer demand therefor.
[0050] In simplest form, heating system 100 is controlled as follows: the temperature within remote water heater 51 is controlled by thermostat 58 , which is electrically connected to remote water heater 51 . Temperature indicator 55 is preferably disposed in the flow of water returning from heating blanket 50 to remote water heater S 1 . As long as the temperature measured by temperature indicator 55 is below a predetermined value assigned to thermostat 58 , remote water heater 51 is heated by heating element 54 , such that the water pumped from water heater 51 to heating blanket 50 is relatively hot, enabling substantial heat transfer, via heating blanket 50 , to storage tank 2 . When the temperature measured by temperature indicator 55 reaches a predetermined value, the heating of remote water heater 51 by heating element 54 is curtailed, such that the transfer of heat to storage tank 2 is gradually reduced, and the temperature of the water within heating blanket 50 approaches the temperature of the liquefied gas within storage tank 2 .
[0051] When consumer demand resumes or increases, vaporized gas is discharged from storage tank 2 via consumer gas line 4 . Liquefied gas within liquid region 2 a vaporizes, with the heat of vaporization being drawn from the liquefied gas. Consequently, the temperature within storage tank 2 is decreased. The increased AT between heating blanket 50 and storage tank 2 results in an increased transfer of heat from heating blanket 50 to storage tank 2 . The temperature in the return flow decreases, such that the temperature measured by temperature indicator 55 falls below the pre-determined value assigned to thermostat 58 , and heating element 54 is activated to heat the water delivered to heating blanket 50 .
[0052] While the activation of thermostat 58 has been described as a simple on-off control, it will be apparent to one skilled in the art that various known programs for activating thermostat 58 could be used. In addition, in some applications, particularly those in which remote water heater 51 is maintained at a relatively constant temperature, the rate of heat delivered by heating blanket 50 to storage tank 2 can be controlled by controlling the flowrate provided by circulation pump 52 .
[0053] In many of the prior-art systems for heating gas storage tanks, an external evaporator vaporizes a stream of liquefied gas as long as consumer demand is maintained. This type of system is extremely inefficient from an energy standpoint, because the energy-intensive evaporation is linked to consumer demand, and not to the intrinsic thermodynamic properties of the gas in the system. In a preferred embodiment of the present invention, a pressure indicator or switch 62 , disposed on consumer gas line 4 , is operatively connected to heating system 100 . When the pressure measured by pressure switch 62 is above a pre-determined value, pressure switch 62 deactivates heating system 100 , because the pressure of the vaporized gas supplied to the consumers via consumer gas line 4 is sufficiently high. As demand continues, the pressure in consumer gas line 4 is reduced, until the pressure measured by pressure switch 62 drops below a pre-determined value, at which point pressure switch 62 activates heating system 100 , which then provides heat to storage tank 2 as described hereinabove.
[0054] Pressure switch 62 may directly or indirectly activate and deactivate circulation pump 52 . Preferably, heating system 100 is configured such that the deactivation of circulation pump 52 deactivates, in turn, heating element 54 . Similarly, when circulation pump 52 is activated, the heating of remote water heater 51 by heating element 54 is enabled.
[0055] In another embodiment of the present invention, CPU 60 receives a data signal from temperature indicator 55 , and is pre-programmed to control heating element 54 (and/or circulation pump 52 ) based upon the value received. In addition, CPU 60 may be configured to receive a data signal from pressure indicator or switch 62 , and to activate or deactivate heating element 54 (and/or circulation pump 52 ) based upon the data signal received.
[0056] It will be evident to one skilled in the art that many other control relationships between pressure switch 62 and heating system 100 are possible. It must be emphasized, however, that the control of heating system 100 is by no means trivial. The design criteria include:
[0057] Minimization of safety risks associated with electrically-powered components in the vicinity of a system containing inflammable or explosive gases
[0058] Quick response to consumer demand
[0059] Ability to cope with periods in which there is no consumer demand in a safe and energy-efficient manner
[0060] Substantially 100% reliability
[0061] The system illustrated in FIG. 2 is particularly useful in underground storage tanks, and involves a minimal modification to the existing equipment, both in terms of equipment and in terms of ease of installation.
[0062] It must be emphasized that various designs and configurations for achieving the requisite heat-exchange relation will be apparent to those skilled in the art.
[0063] [0063]FIG. 3 a is a top, schematic, partially cut-away view of heating blanket 50 , which includes an inlet tube 72 for supplying hot water for heating the storage tank, an outlet tube 74 for returning water to the reservoir, a serpentine tube 76 connecting between inlet tube 72 and outlet tube 74 , and a flexible, conductive mat or plate 78 . The difference between the temperature of the water flowing through serpentine tube 76 and the temperature of the liquefied gas in the storage tank provides the driving force for the transfer of heat from the water, through the wall of serpentine tube 76 , via conductive plate 78 , to the wall of the storage tank, and from there, to the liquefied gas contained therein. Conductive plate 78 is typically made of aluminum, and preferably has a corrugated surface 79 to provide for an increased surface area for heat transfer. The flexibility of conductive plate 78 allows for a good fit with the external wall of the storage tank, such that efficient heat transfer is achieved.
[0064] A side view of heating blanket 50 of FIG. 3 a is provided in FIG. 3 b . It should be appreciated that the thin, compact heating blanket 50 described herein is advantageously installed in new gas storage systems, and is also advantageously retrofitted in existing gas storage systems.
[0065] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, no citation or identification of any reference in this application shall be construed as an admission that such reference is available as prior art to the present invention.
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A method for supplying a vaporized gas, including: (a) providing a system having: (i) a storage tank for storing liquefied gas; (ii) a heat exchanger external to the tank, disposed in a heat-exchange relationship with a wall of the tank; (iii) a device for delivering a heat-exchange liquid from a reservoir to the heat exchanger, and (iv) a delivery line for directly transferring the vaporized gas from the heat exchanger to the consumer; (b) supplying the vaporized gas directly to the consumer, according to consumer demand; (c) upon vaporization of a portion of the liquefied gas within the storage tank, and subsequent cooling of the liquefied gas within the storage tank, transferring heat from the heat-exchange liquid to the tank via the heat exchanger, so as to increase the tank pressure.
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RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 09/120,934, filed Jul. 22, 1998, entitled “Bathtub-Bathseat”, which is hereby incorporated fully by reference.
BACKGROUND OF THE INVENTION
The invention relates to a bathtub and bathseat combination and in particular to an apparatus for use interchangeably in a bathtub configuration and a bathseat configuration.
Children's bathtubs allow persons to bathe a child in a manner in which the child is safe and comfortable. These bathtubs are typically adapted to fit within an adult-sized bathtub, or even a sink. Persons can place the children's bathtub into the adult bathtub or the sink, fill the children's bathtub with water, put the child into the children's bathtub, and bathe the child.
Bathseats can also be used to bathe the child, with the child positioned in a seated, upright position. Typically, these seats are used for children that are at least a few months old and have enough neck strength to support their heads.
SUMMARY OF THE INVENTION
In general, in one aspect, the invention features an apparatus including a tub adapted to receive a child and to hold water in a top side at least when oriented in a reclined position, the tub having a back side, a head end, and a foot end, a first arm portion and a second arm portion connected by a front cross member, the first and second arm portions each being pivotally attached to the tub about an axis displaced from the foot end of the tub into at least first and second positions, the front cross member being disposed above, and displaced from, the top side of the tub when the arm portions are in the first position, and an elongated member attached to the front cross member at a first end and extending from the front cross member to a second end having a foot disposed below the foot end of the tub and adapted to engage a smooth surface, the elongated member extending toward the foot end of the tub to provide a passive crotch restraint for a child received by the tub when the arm portions are in the first position.
Implementations of the invention may include one or more of the following features. The apparatus can further comprise a third arm portion connected to the first arm portion and a fourth arm portion connected to the second arm portion, the third and fourth arm portions extending from the first and second arm portions behind the back side of the tub and toward the head end of the tub when the first and second arm portions are in the second position. The apparatus can further comprise a rear cross member connecting the third and fourth arm portions to form a rear support. The rear support can include a pair of feet adapted to engage the bathtub floor. The front cross member can be disposed adjacent to the top side of the tub near the foot end when the first and second arm portions are in the second position. The tub can define a hole near the foot end for slidably receiving the elongated member. The apparatus can further comprise a coupling adapted to secure the first arm portion to the tub when the first arm portion is in the second position to prevent rotation of the first arm portion toward the first position when a torque less than a predetermined torque is applied to the first arm portion relative to the tub. The coupling can be further adapted to substantially prevent rotation of the first arm portion when the first arm portion is in the first position. The tub, the arm portions, and the elongated member can be arranged to be received by a kitchen sink or an adult-sized bathtub.
In general, in another aspect, the invention features an apparatus adapted to receive a child and to be pivoted between a bathtub position and a bathseat position, the apparatus including a tub having a front side and a rear side, the front side adapted to receive a child and to hold water, the tub further having a head end and a foot end and defining an opening near the foot end, a support including a pair of arm portions, a first cross member, and a second cross member, each arm portion being selectively pivotally coupled to the tub to a bathtub position and a bathseat position, the first cross member connecting arm portions above the front side of the tub when the arm portions are in the bathseat position, the second cross member connecting the arm portions behind the rear side of the tub in both the bathtub and bathseat positions, the support including a pair of feet disposed behind the rear side of the tub and adapted to be mounted to a smooth surface, and a leg depending from the first cross member and configured to be slidably received by the hole in the tub, the leg including a foot displaced from the first cross member and adapted to be mounted to the smooth surface, wherein feet of the support and the foot of the leg are adapted to be received by a kitchen sink.
In general, in another aspect, the invention features an infant bathseat including a tub having a bottom surface and raised side, head and foot portions defining a volume for containing water when the tub is in a reclining position with the head and foot portions positioned above the bottom surface, an arm portion on each side of the tub extending toward the foot portion and extending below the tub adjacent the, each arm portion being pivotally connected to the tub between the foot and the head portions, whereby on rotation of the arm portions away from the tub, the tub is raised from a reclining to a seating position with the head portion elevated above the foot portion, a cross member connecting the arm portions near the foot portion, and a support member extending vertically downward from the cross member and with the tub in a seating position forming a passive restraint for a child when seated in the bathseat.
Implementations of the invention may include one or more of the following features. The arm portions can be disposed above the foot portion when the tub is in the seating position. The arm portion can be fixedly attached to a shaft having a generally dumbbell shape, and the tub can include a hub defining a slot in communication with a circular hole, the hole being adapted to rotatably receive the shaft, the slot being adapted to slidably receive the shaft when the length of the dumbbell shape is directed along the length of the shaft. The arms and the cross member are integrally connected.
Embodiments of the invention may provide one or more of the following advantages. A single apparatus can be used as both a bathtub and a bathseat. Accidental movement of an apparatus from a bathseat configuration to a bathtub configuration can be inhibited. An arm portion of a combined bathtub-bathseat can be selectively pivoted and locked. A single apparatus can adapt to changing needs of the child and the child's parents as the child grows. An apparatus can be stably mounted or attached to a bathtub. Other advantages will become apparent from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a bathtub-bathseat, in a bathseat position.
FIG. 2 is a perspective view of the bathtub-bathseat, shown in FIG. 1, in a reclining bathtub position.
FIG. 3 is a perspective exploded view of the bathtub-bathseat shown in FIGS. 1-2.
FIG. 4 is a plan view of the left side of a tub of the bathtub-bathseat shown in FIGS. 1-2.
FIG. 5 is a cross-sectional view of a rod shown schematically in FIG. 3, as indicated by a line 5 — 5 in FIG. 3 .
FIG. 6 is a schematic cross-sectional view of a portion of an arm and a portion of the tub shown in FIG. 2 as indicated by a line 6 — 6 in FIG. 2 .
FIG. 6A is a plan view of the left side of a tub of the bathtub-bathseat shown in FIGS. 1-2 with a portion of the tub removed to shown a vane of the tub.
FIG. 7 is a schematic cross-sectional view of a rod in a key-hole for the bathtub-bathseat in the position shown in FIG. 2 .
FIG. 8 is a schematic cross-sectional view of a rod in a key-hole for the bathtub-bathseat in the position shown in FIG. 1 .
FIG. 9 is a left side view of the bathtub-bathseat, shown in FIG. 1, in an assembly position.
FIG. 10 is a schematic cross-sectional view of a rod in a key-hole for the bathtub-bathseat in an assembly position shown in FIG. 9 .
FIG. 11 is a schematic side view of a support and a portion of the tub of the bathtub-bathseat in the bathseat position.
FIG. 12 is a schematic side view of a support and a portion of the tub of the bathtub-bathseat in the bathtub position.
FIG. 13 is a perspective view of the bathtub-bathseat shown in FIG. 1 mounted in an adult-sized bathtub.
FIG. 14 is a side view of the bathtub-bathseat shown in FIG. 2 mounted in a sink.
FIG. 15 is a schematic cross-sectional view of an alternative shape of a rod of the bathtub-bathseat shown in FIGS. 1 - 2 .
DESCRIPTION OF PREFERRED EMBODIMENTS
The invention provides an apparatus that can be used as a bathtub for bathing an infant and converted for use as a bathseat for bathing a child. The apparatus can be locked into the bathseat configuration to help guard against the apparatus accidentally shifting from the bathseat configuration to the bathtub configuration. The apparatus can be securely attached or mounted to the floor or hubs 55 of an adult-sized bathtub or attached or mounted at least partially within a sink.
As shown in FIGS. 1-2, a bathtub-bathseat assembly 10 includes a tub or basin 12 , a substantially rectangular (see FIG. 3) arm 14 including two sides 16 and 18 connected by cross members 20 and 22 , and a front support 24 . Assembly 10 can be positioned in either the bathseat position, shown in FIG. 1, or the bathtub position, shown in FIG. 2 . Assembly 10 is configured to be placed in a sink or placed within an adult-sized bathtub and mounted to the floor of the adult-sized bathtub. Rounded edges and corners of assembly 10 help prevent injury.
Tub 12 has a bottom wall 26 and side walls 28 and 30 (see FIG. 4) that provide a volume 32 . Volume 32 is configured for receiving a child. Bottom wall 26 is contoured to accommodate a child and includes a bottom/back rest 34 . Rest 34 includes a top portion 36 adapted so that an infant can sit on top portion 36 . Rest 34 also includes a front portion 38 adapted to provide back support to a child sitting on a surface region 40 (not shown in FIG. 2) of bottom wall 26 . Bottom wall 26 is integrally connected to side walls 28 and 30 such that tub 12 is adapted to hold water in volume 32 , especially when in the bathtub position. A drainage hole 33 is provided through bottom wall 26 (FIG. 3 ).
Referring to FIG. 3, tub 12 has a head end 42 and a foot end 44 . At foot end 42 , a ledge 46 provides a recess 48 and includes an upwardly directed tab 50 . Ledge 46 and a foot end portion of bottom wall 26 also provide a hole 52 through ledge 46 and bottom wall 26 .
Referring also to FIG. 4, tub 12 provides key holes 54 (only one is shown in FIG. 4) in exterior portions of each side of tub 12 . Key holes 54 do not extend through side walls 28 and 30 of tub 12 . Each key hole 54 has an upper circular hole 56 , centered along an axis 64 , and a lower slot 58 in fluid communication with hole 56 . As shown in FIG. 4, slot 58 has a width 60 relatively smaller than a diameter 62 of hole 56 . Key holes 54 are located along the sides of tub 12 closer to foot end 44 than to head end 42 .
Arm 14 includes two sets of discs 66 and 68 integrally connected by shafts 70 (schematically shown in FIG. 3) that are adapted to be received by key holes 54 . Discs 66 and 68 and shafts 70 are centered on an axis 72 . Shafts 70 are configured to be slidingly received by slots 58 of key holes 54 in tub 12 and to be rotatingly received within holes 56 in key holes 54 . As shown in FIG. 5, shaft 70 includes a plurality of ribs 76 arranged to effectively provide two flat sides indicated by lines 78 and two rounded ends 80 . Flat sides 78 are separated by a distance 82 approximately equal to, but slightly smaller than width 60 of slot 58 in tub 12 . Rounded ends 80 effectively provide the curvature of a circle 84 having a diameter 86 approximately equal to, but slightly less than, diameter 62 of hole 56 in tub 12 and larger than width 60 of slot 58 . Shafts 70 are schematically shown as rectangles with rounded ends in FIGS. 3, 7 - 8 , and 10 .
Referring to FIGS. 3 and 5, a ramp surface 74 is disposed adjacent the periphery of each disc 68 . Ramp 74 has a thin end 88 and a thick end 90 , with a flat top portion 92 .
Returning to FIGS. 1-2, arm 14 is pivotally connected to tub 12 for movement about axis 64 .
Referring to FIGS. 6 and 6A, tub 12 includes vanes 94 (only one shown) forming part of key holes 54 (FIGS. 3 - 4 ). As shown in FIG. 6A (partially cut away with the portion of tub 12 shown in FIGS. 3-4 forming part of key holes 54 removed), vane 94 has a semicircular cutout 96 of the same diameter 62 as hole 56 (FIG. 4) and is centered along axis 64 . FIG. 6 shows the relationship of discs 66 and 68 , and shaft 70 of arm 14 , to tub 12 . As shown, side 16 of arm 14 is disposed adjacent to tub 12 and, in particular, to a wall 100 (see also FIGS. 3-4) of tub 12 forming part of key hole 54 . Disc 66 is disposed adjacent to an opposite side of wall 100 from side 16 . Vane 94 is disposed between discs 66 and 68 . Shaft 70 extends through hole 56 and cutout 96 (FIG. 6 A). Vane 94 has a rib 98 disposed and configured to interfere with ramp 74 (FIGS. 3 and 5) when arm 14 is pivoted about axis 64 .
Referring to FIGS. 1-3, arm 14 is shaped and connected to tub 12 such that cross member 20 is disposed in front of tub 12 and cross member 22 is disposed behind tub 12 . Side 16 has a somewhat “Z” shape when viewed from the left side of assembly 10 and side 18 has a somewhat “S” shape when viewed from the right side of assembly 10 . Cross member 20 includes posts 106 (only one is shown in FIG. 3) in a trough 102 for receiving a toy 104 (FIGS. 1 - 2 ). A hole 118 is provided in the bottom of trough 102 to allow liquid to drain. Forward of hole 118 , shown in FIG. 3 with a portion of cross member 20 cut away, are two posts 120 (only one of which is (schematically) shown).
Referring to FIG. 3, front support 24 includes a base 124 and a lever 126 . Two holes 122 (only one shown in FIG. 3) in base 124 are sized to pivotally receive posts 120 of arm 14 . Lever 126 includes two posts 125 (only one (schematically) shown in FIG. 3) adapted to be received by holes 127 in base 124 . Lever 126 has a top end 121 and a middle section 119 that are configured to be inserted through hole 52 in tub 12 and a bottom end 123 that is larger than hole 52 . Lever 126 is coupled to base 124 by a spring 128 and is pivotally received about holes 127 in an opening 130 in base 124 . Spring 128 is received by a tube (not shown) inside opening 130 of base 124 and receives a rod (not shown) extending from lever 126 . Spring 128 biases lever 126 to rotate about the center axis of holes 127 . Lever 126 includes an upwardly-extending tab 132 to interfere with an end wall 134 of opening 130 in base 124 . Lever 126 also includes a downwardly-extending tab 142 configured to be received by recess 48 in cross member 20 of tub 12 . Tab 142 extends downwardly further than tab 50 of tub 12 extends upwardly plus the depth of recess 48 .
Suction cups are attached to the bottoms of arm 14 and front support 24 for attaching to the floor of an adult-sized bathtub. Two suction cups 108 and 110 are mounted to the bottoms of junction 112 and 114 between cross member 22 and sides 16 and 18 , respectively. A suction cup 116 is mounted to the bottom of base 124 . The locations of the suction cups 108 , 110 , and 116 , as shown, provides stability to assembly 10 when, e.g., mounted, attached, or rested on a surface such as a bathtub floor.
A plug 136 is received by drainage hole 33 . Tabs 138 interfere with a bracket 140 (see also FIG. 2) on the bottom of tub 12 to inhibit rotation of plug 136 when received by hole 33 .
Assembly 10 is assembled as follows. Front support 24 is assembled by placing spring 128 in the tube inside base 124 and inserting lever 126 into opening 130 . Lever 126 is inserted such that posts 125 are received by holes 127 and spring 128 is received by the rod extending from lever 126 . Suction cup 116 is attached to the bottom of base 124 . Suction cups 108 and 110 are attached to the bottoms of junctions 112 and 114 of arm 14 . The top of support 24 is inserted through hole 52 in tub 12 and base 124 coupled to arm 14 with holes 122 of base 124 receiving posts 120 of arm 14 . As shown in FIG. 9, arm 14 is rotated substantially perpendicular to tub 12 and slid over tub 12 as indicated by arrow 144 and up as indicated by arrow 146 such that shafts 70 have their flat edges 148 aligned parallel to the walls of slots 58 , allowing key holes 54 to receive shafts 70 as shown in FIG. 10 . Axis 72 of arm 14 thus is substantially aligned with axis 64 of holes 56 . Arm 14 is rotated as indicated by arrow 150 in FIG. 8 toward the bathseat position shown in FIG. 1, with shaft 70 rotating to its bathseat position as shown in FIG. 8 . Ramp 74 (FIGS. 3 and 5) ramps over rib 94 on disc 68 . Thick end 90 of ramp 74 inhibits rotation in a direction 190 opposite to direction 150 , thus inhibiting edges 148 of shafts 70 from realigning with slots 58 . Arm 14 is thus inhibited from being removed from tub 12 . Toy 104 is inserted into trough 102 with toy 104 being received by posts 106 . Plug 136 is inserted into drainage hole 33 .
In operation, assembly 10 can be positioned and used interchangeably in a bathseat configuration (FIG. 1) and a bathtub configuration (FIG. 2 ).
With assembly 10 in the bathseat position, shaft 70 is in the position shown in FIG. 8, and front support 24 is in the position shown in FIG. 11 (arm 14 not shown in FIG. 11 ). Front support 24 extends downwardly from cross member 20 through hole 52 of tub 12 to provide a passive crotch restraint for a child seated in volume 32 provided by tub 12 . As shown in FIG. 11, bottom end 123 of support 24 is not inserted up through hole 52 in tub 12 , bottom end 123 being unable to fit through hole 123 . This helps prevent arm 14 from being rotated such that edges 148 of shafts 70 realign with slots 58 , thus inhibiting disassembly of arm 14 from tub 12 . Downwardly-extending tab 142 is received by recess 48 in tub 12 . Cross members 20 and 22 are separated from tub 12 .
In the bathseat position, as shown in FIG. 13, assembly 10 can be mounted in an adult-sized bathtub 160 (shown schematically and out of scale). Suction cups 108 , 110 , and 116 (FIG. 3) removably connect assembly 10 to the floor of the tub 160 , with sides 16 and 18 (not shown in FIG. 11) and cross member 22 providing support to assembly 10 . The tub 160 can be filled with water and a child placed in volume 32 as shown. The child sits on region 40 with the child's lower back resting against front portion 38 of rest 34 and the child's legs extending through openings 162 and 164 (FIG. 1) between front support 24 , cross member 20 , ledge 46 of tub 12 , and sides of the tub 12 . Front support 24 serves as a passive crotch restraint in this position.
Assembly 10 can be repositioned from the bathseat position to the bathtub position. The child in volume 32 should be removed, and water in volume 32 drained by opening plug 136 . Referring to FIGS. 1 and 11, cross member 20 is separated from tub 12 , lifting tab 142 from recess 48 as indicated by arrow 166 in FIG. 11 . (The weight of a child in volume 32 will inhibit separating cross member 20 from tub 12 .) Front support 24 is squeezed to push lever 126 into opening 130 . Tabs 142 and 50 and a wall of recess 48 inhibit lever 126 from being pushed into opening 130 unless front support 24 is moved upward in direction 166 to remove tab 142 from recess 48 . Cross member 20 is brought close to ledge 46 , such that support 24 moves through hole 52 in tub 12 in direction 168 shown in FIG. 12, until arm 14 (shown schematically in FIG. 12) interferes with tub 12 . Shaft 70 rotates in direction 150 until it reaches its bathtub position shown in FIG. 7 .
In the bathtub position, as shown in FIG. 14, assembly 10 can be mounted in a sink 170 (e.g., disposed in a counter 174 ). Tub 12 can be filled with water and an infant placed in volume 32 as shown with substantially the infant's entire body, including legs, being received by volume 32 . The infant sits on top portion 36 and uses the portion of bottom 26 between top portion 36 and head end 42 as a back rest. In the bathtub position, cross member 20 is adjacent foot end 44 of tub 12 and cross member 22 is closer to head end 42 of tub 12 than when in the bathseat position (FIG. 1 ).
To move assembly 10 from the bathtub position to the bathseat position, cross member 20 is separated from tub 12 . The infant should be removed, and the water drained by opening plug 136 . Separating cross member 20 from tub 12 causes shaft 70 to rotate in direction 190 as indicated in FIG. 7 and causes lever 126 to rub against a wall 172 (FIG. 12) of hole 52 , causing lever 126 to be pushed into opening 130 . When tab 142 is disposed higher than tab 50 , spring 128 pushes lever 126 away from base 124 . Tab 132 on lever 126 hits wall 134 and stops pivoting of lever 126 . Support 24 is lowered such that tab 142 is received by recess 28 . Shaft 70 is again in its bathseat position shown in FIG. 8 .
Other embodiments are within the scope of the following claims. For example, a dumbbell-shaped shaft 180 shown in FIG. 15 can be used instead of shaft 70 . Hole 56 can rotatably receive shaft 180 if the length of the shaft 180 is aligned with the length of slot 58 .
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A tub defines a volume for receiving a child and holding water in a top side at least when oriented in a reclined position, the tub having a back side, head and foot ends, and first and second arms connected by a front cross member. The first and second arms are pivotally attached to the tub about an axis displaced from the foot end of the tub into at least first and second positions. The front cross member is disposed above, and displaced from, the top side of the tub when the arms are in first position. An elongated member is attached to the front cross member at a first end and extends from the front cross member to a second end having a foot disposed below the foot end of the tub and adapted to engage a smooth surface. The elongated member extends toward the foot end of the tub to provide a passive crotch restraint for a child received by the tub when the arms are in first position.
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FIELD OF THE INVENTION
The present invention relates to a pressure control system for a construction machine. More particularly, the present invention relates to a pressure control system for a construction machine, in which a variable adjustment of the set pressure of a relief valve that limits a set pressure of the hydraulic system can be performed based on the pressure of the hydraulic system or the input value by manipulation of a joystick by a user.
BACKGROUND OF THE INVENTION
In general, in a hydraulic system applied to an excavator or the like, a one or two stage relief value having a set pressure is installed so that the pressure of the hydraulic system can be maintained at a constant level to drive a hydraulic actuator or the like. Such a relief valve is used to perform a pressure boosting function of increasing the set pressure of the relief value upon the selection of the function by an operator depending on the work conditions. That is, the set pressure of the relief valve is boosted temporarily by the operator so that a torque of a force of the hydraulic actuator (e.g., a boom cylinder) can be increased.
In the meantime, the excavator allows a high load to occur during the work so that there frequently occurs a case where a hydraulic fluid discharged from a hydraulic pump is relieved. In this case, when the set pressure of the relief valve is boosted, the discharged hydraulic fluid is not relieved so that a loss of the hydraulic fluid relieved can be reduced. On the other hand, an operator suffers from an inconvenience of carrying out the pressure boosting function depending on the work conditions during the work, and thus such a hydraulic system is practically not applied to the equipment.
DETAILED DESCRIPTION OF THE INVENTION
Technical Problems
Accordingly, the present invention has been made to solve the aforementioned problem occurring in the prior art, and it is an object of the present invention to provide a pressure control system for a construction machine, in which the set pressure of the relief valve is boosted automatically based on the pressure of the hydraulic system or the input value by manipulation of the joystick by a user so that a loss of a hydraulic fluid that is relieved under the work condition of a high load can be reduced, and the set pressure of the relief valve can be maintained at the optimal level to thereby protect the hydraulic parts.
Technical Solution
To accomplish the above object, in one aspect, there is provided a pressure control system for a construction machine in accordance with an embodiment of the present invention, including:
a variable displacement hydraulic pump;
a plurality of hydraulic actuators connected to the hydraulic pump;
a plurality of joysticks configured to respectively output control signals according to manipulation amounts thereof;
a flow rate control valve installed in a flow path between the hydraulic pump and the hydraulic actuators and configured to be shifted to control an operation of the hydraulic actuators in response to a control signal according to an manipulation of each of the joysticks;
a main relief valve installed in a flow path between a discharge flow path on an upstream side of the hydraulic pump and a hydraulic tank and configured to return a hydraulic fluid to the hydraulic tank when a high load that exceeds a set pressure of the main relief valve occurs in the system;
a pressure adjustment means configured to adjust the set pressure of the main relief valve in a consecutive or stepwise manner;
a pressure detection means configured to detect a pressure of the hydraulic fluid on the discharge side of the hydraulic pump 1 ; and
a controller configured to determine the set pressure of the relief valve, which is required according to an input value by the manipulation of the joystick and a system pressure that is detected by the pressure detection means and configured to output a control signal to the pressure adjustment means so as to enable the set pressure of the relief valve to be variably adjusted to the determined set pressure.
In another aspect, there is also provided a pressure control system for a construction machine in accordance with an embodiment of the present invention, including a variable displacement hydraulic pump, a hydraulic actuator connected to the hydraulic pump, a plurality of joysticks, a flow rate control valve configured to be shifted to control the drive of the actuator, a main relief valve configured to return a hydraulic fluid to a hydraulic tank when a high load that exceeds a set pressure of the main relief valve occurs in the system, a pressure adjustment means configured to adjust the set pressure of the main relief valve in a consecutive or stepwise manner, a pressure detection means configured to detect a pressure of the hydraulic fluid on the discharge side of the hydraulic pump, and a controller configured to control the set pressure of the relief valve to be adjusted based on an input value of a control signal by the manipulation of the joystick and a system pressure, the pressure control system including:
a first step of detecting the input value of the control signal by the manipulation of the joystick and the system pressure by the pressure detection means;
a second step of determining the set pressure of the relief valve based on the input value of the joystick and the system pressure, respectively, or determining the set pressure of the relief valve based on both the input value of the joystick and the system pressure;
a third step of determining a final set pressure of the relief valve among the set pressures of the relief valve determined in the second step; and
a fifth step of outputting a control signal to the pressure adjustment means to control the pressure of the relief valve to be set to the final set pressure determined in the third step.
In accordance with a preferred embodiment of the present invention, the pressure detection means may be a pressure sensor that detects the pressure of the hydraulic fluid on the discharge side of the hydraulic pump and transmits a detection signal to the controller.
The pressure detection means may be a pressure switch that is turned on/off to generate a signal when the pressure of the hydraulic fluid on the discharge side of the hydraulic pump reaches the set pressure value of the main relief valve.
The pressure adjustment means may be a solenoid valve that is shifted to output a control signal to the relief valve in response to an electric control signal applied thereto from the controller.
The pressure adjustment means may be an electro proportional valve that is driven to output a secondary signal pressure to the relief valve in response to the electric control signal applied thereto from the controller 9 .
The input value of the control signal by the manipulation of the joystick may be an input signal by a pressure sensor that detects a pilot pressure.
The input value of the control signal by the manipulation of the joystick may be an input signal by a pressure switch that detects the pilot pressure.
The input value of the control signal by the manipulation of the joystick may be an input signal by an electric joystick.
The set pressure of the relief valve may be set to be relatively lower than the previous set pressure of the relief valve when a control value corresponding to manipulation of the joystick during low load construction work is input to the controller.
The set pressure of the relief valve may be set to be relatively higher than the previous set pressure of the relief valve when a control value corresponding to manipulation of the joystick during high load construction work is input to the controller, or the system pressure is determined to approximate the previous set pressure of the relief valve. After being set to be relatively higher the set pressure of the relief valve is reduced either (1) after a predetermined period of time, or (2) when relief loss is expected due to system pressure being higher than the previously set pressure.
The pressure control system may further include a fourth step S 400 of determining whether to activate or inactivate a function of performing an automatic variable adjustment of the set pressure of the relief valve based on the input value of the joystick and the system pressure through selection of a user setting means.
Advantageous Effect
The pressure control system for a construction machine in accordance with an embodiment of the present invention as constructed above has the following advantages.
The set pressure of the relief valve is boosted automatically based on the pressure of the hydraulic system or the input value of the joystick by a user so that a loss of a hydraulic fluid that is relieved under the work condition of a high load can be reduced, thereby improving workability, and the set pressure of the relief valve can be maintained at the optimal level, thereby extending the lifespan of the hydraulic parts.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects, other features and advantages of the present invention will become more apparent by describing the preferred embodiments thereof with reference to the accompanying drawings, in which:
FIG. 1 is a hydraulic circuit diagram showing a pressure control system for a construction machine in accordance with an embodiment of the present invention; and
FIG. 2 is a flowchart showing a pressure control system for a construction machine in accordance with an embodiment of the present invention.
PREFERRED EMBODIMENTS OF THE INVENTION
Now, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The matters defined in the description, such as the detailed construction and elements, are nothing but specific details provided to assist those of ordinary skill in the art in a comprehensive understanding of the invention, and the present invention is not limited to the embodiments disclosed hereinafter.
A pressure control system for a construction machine in accordance with an embodiment of the present invention as shown in FIG. 1 includes:
a variable displacement hydraulic pump (hereinafter, referred to as “hydraulic pump”) 1 ;
a plurality of hydraulic actuators (referring to “boom cylinder” and the like) 2 that is connected to the hydraulic pump 1 ;
a plurality of joysticks 3 that is configured to respectively output control signals according to manipulation amounts thereof;\
a flow rate control valve (MCV) 4 that is installed in a flow path between the hydraulic pump 1 and the hydraulic actuators 2 and is configured to be shifted to control the drive of the hydraulic actuators 2 in response to a control signal according to an manipulation of each of the joysticks 3 ;
a main relief valve (hereinafter, referred to as “relief valve”) 6 that is installed in a flow path 10 between a discharge flow path 5 on an upstream side of the hydraulic pump 2 and a hydraulic tank T and is configured to return a hydraulic fluid to the hydraulic tank when a high load exceeding a set pressure of the main relief valve occurs in the system;
a pressure adjustment means 7 that is configured to adjust the set pressure of the main relief valve 6 in a consecutive or stepwise manner;
a pressure detection means 8 that is configured to detect a pressure of the hydraulic fluid on the discharge side of the hydraulic pump 1 ; and
a controller 9 that is configured to determine the set pressure of the relief valve 6 , which is required according to an input value by the manipulation of the joystick and a system pressure that is detected by the pressure detection means and is configured to output a control signal to the pressure adjustment means so as to enable the set pressure of the relief valve 6 to be variably adjusted to the determined set pressure.
In a pressure control system for a construction machine in accordance with an embodiment of the present invention shown in FIGS. 1 and 2 including a variable displacement hydraulic pump 1 , a hydraulic actuator (i.e., boom cylinder or the like) 2 connected to the hydraulic pump 1 , a plurality of joysticks 3 , a flow rate control valve (MCV) 4 configured to be shifted to control the drive of the actuator 2 , a main relief valve (hereinafter, referred to as “relief valve”) 6 configured to return a hydraulic fluid to a hydraulic tank when a high load that exceeds a set pressure of the main relief valve occurs in the system, a pressure adjustment means 7 configured to adjust the set pressure of the main relief valve 6 in a consecutive or stepwise manner, a pressure detection means 8 configured to detect a pressure of the hydraulic fluid on the discharge side of the hydraulic pump 1 , and a controller 9 configured to control the set pressure of the relief valve to be adjusted based on an input value of a control signal by the manipulation of the joystick 3 and a system pressure, the pressure control system includes:
a first step (S 100 A, S 100 B) of detecting the input value of the control signal by the manipulation of the joystick 3 and the system pressure by the pressure detection means 8 ;
a second step (S 200 A, S 200 B) of determining the set pressure of the relief valve 6 based on the input value of the control signal of the joystick 3 and the system pressure, respectively, or (S 200 C) determining the set pressure of the relief valve 6 based on both the input value of the control signal of the joystick 3 and the system pressure;
a third step (S 300 ) of determining a final set pressure of the relief valve 6 among the set pressures of the relief valve determined in the second step (S 200 A, S 200 B, S 200 C), and determining a required relief pressure for the relief valve 6 ;
a fourth step (S 400 ) of determining whether to activate or inactivate a function of performing an automatic variable adjustment of the set pressure of the relief valve 6 based on the input value of the joystick 3 and the system pressure through selection of a user setting means 11 .
a fifth step (S 500 A, S 500 B) of outputting a control signal to the pressure adjustment means to control the pressure of the relief valve 6 to be set to the required relief pressure determined in the third step S 300 .
Herein, the pressure detection means 8 used in the present invention is a pressure sensor that detects the pressure of the hydraulic fluid on the discharge side of the hydraulic pump 1 and transmits a detection signal to the controller 9 .
The pressure detection means 8 used in the present invention is a pressure switch that is turned on/off to generate a signal when the pressure of the hydraulic fluid on the discharge side of the hydraulic pump 1 reaches the set pressure value of the main relief valve.
The pressure adjustment means 7 used in the present invention is a solenoid valve that is shifted to output a control signal to the relief valve 6 in response to an electric control signal applied thereto from the controller 9 .
The pressure adjustment means 7 used in the present invention is an electro proportional valve that is driven to output a secondary signal pressure to the relief valve in response to the electric control signal applied thereto from the controller 9 .
The input value of the control signal by the manipulation of the joystick 3 is an input signal by a pressure sensor that detects a pilot pressure.
The input value of the control signal by the manipulation of the joystick 3 is an input signal by a pressure switch that detects the pilot pressure.
The input value of the control signal by the manipulation of the joystick 3 is an input signal by an electric joystick.
The set pressure of the relief valve 6 is set to be relatively lower than the previous set pressure of the relief valve 6 when a control value of the joystick of a pattern that is manipulated by a low load is inputted to the controller 9 .
The set pressure of the relief valve 6 is set to be relatively higher than the previous set pressure of the relief valve 6 when a control value of the joystick of a pattern that is manipulated by a high load is inputted to the controller 9 or the system pressure is determined to approximate the previous set pressure of the relief valve 6 .
The set pressure of the relief valve 6 is re-set to be lower than the previous set pressure of the relief valve when the set pressure of the relief valve 6 is set to be higher than the previous set value of the relief valve 6 , but the set pressure thereof is maintained over a predetermined time period or approximates a re-set high pressure to expect a relief loss.
Hereinafter, a use example of the pressure control system for a construction machine in accordance with an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
As shown in FIG. 1 , when a manipulation signal is inputted to a signal pressure port of the flow rate control valve 4 according to the manipulation of the joystick 3 by an operator to cause a spool of the flow rate control valve 4 to be shifted, a hydraulic fluid discharged from the hydraulic pump 1 is supplied to the actuator 2 via the flow rate control valve 4 along the discharge flow path 5 to drive the actuator 5 . For example, the hydraulic fluid from the hydraulic pump 1 is supplied to a large chamber of the boom cylinder to drive the boom cylinder in a stretchable manner. In this case, a hydraulic fluid returned to the flow rate control valve 4 from the actuator 2 is returned to the hydraulic tank T via the flow rate control valve 4 . For example, the hydraulic fluid from a small chamber of the boom cylinder is returned to the hydraulic tank T.
At this time, a detection signal of the system pressure detected by the pressure detection means 8 installed on the discharge flow path 5 side of the hydraulic pump 1 and a detection signal of a control signal value by the manipulation of the joystick 3 are transmitted to the controller 9 , respectively. For this reason, the controller 9 outputs a control signal to the pressure adjustment means 7 so as to adjust the set pressure of the relief valve 6 based on the control signal input value by the manipulation of the joystick 3 and the system pressure.
An adjustment of the set pressure of the relief valve based on the system pressure and the control signal input value by the manipulation of the joystick 3 as described above will be described hereinafter with reference to the flowchart of FIG. 2 .
As shown in FIG. 2 , an input value (S 100 A) of the control signal by the manipulation of the joystick 3 and the system pressure (S 100 B) by the pressure detection means 8 are detected, respectively, and detection signals are applied to the controller 9 .
At step S 200 A, the set pressure of the relief valve 6 is determined based on the input value (referring to “instruction value”) of the joystick 3 . At step S 200 B, the set pressure of the relief valve 6 is determined based on the system pressure. At step S 200 C, the set pressure of the relief valve 6 is determined based on both the input value of the joystick 3 and the system pressure.
At subsequent step S 300 , a final set pressure of the relief valve 6 is determined among the set pressures of the relief valve determined in the second step (S 200 A, S 200 B, S 200 C).
The program proceeds to step S 400 where the controller 9 determines whether to activate or inactivate a function of performing an automatic variable adjustment of the set pressure of the relief valve 6 based on the input value of the joystick 3 and the system pressure through selection of a user setting means 11 . If it is determined at step S 400 that the function of performing an automatic variable adjustment of the set pressure of the relief valve 6 is activated, the program proceeds to step S 500 A.
On the contrary, it is determined at step S 400 that the function of performing an automatic variable adjustment of the set pressure of the relief valve 6 is inactivated, the program proceeds to step S 500 B where the set pressure of the relief valve 6 is set to a specific value based on the input value of the joystick 3 and the system pressure through selection of the user setting means 11 .
At step S 500 A, an automatic variable adjustment of the set pressure of the relief valve 6 can be performed based on the input value of the joystick 3 and the system pressure.
In this case, the set pressure of the relief valve 6 is set to be relatively lower than the previous set pressure of the relief valve 6 when a control value of the joystick 3 of a pattern that is manipulated by a low load is inputted to the controller 9 so that hydraulic parts can be protected from an instantaneous collision or an external pressure (S 500 A, S 500 C, S 600 A).
In the meantime, at step 600 B, the set pressure of the relief valve 6 is set to be relatively higher than the previous set pressure of the relief valve 6 when a control value of the joystick 3 of a pattern that is manipulated by a high load is inputted to the controller 9 or the system pressure is determined to approximate the previous set pressure of the relief valve 6 so that a loss by relief can be minimized.
On the other hand, at steps S 700 A and 700 B, the set pressure of the relief valve 6 is re-set to be lower than the previous set pressure of the relief valve when the set pressure of the relief valve 6 is set to be higher than the previous set value of the relief valve 6 , but the set pressure thereof is maintained over a predetermined time period or approximates a re-set high pressure to expect a relief loss.
At step 500 B, the set pressure of the relief valve 6 may be set to a specific value required according to the work conditions, i.e., the set pressure of the relief valve 6 is fixed to a selected value without being changed depending on the input value of the joystick 3 and the system pressure.
According to the pressure control system for a construction machine in accordance with an embodiment of the present invention as described above, the set pressure of the relief valve is automatically boosted based on the pressure of the hydraulic system or the input value of the joystick by a user so that a loss of the flow rate of the hydraulic fluid that is relieved under the work condition of a high load can be reduced and the set pressure of the relief valve can be maintained at the optimal level to thereby protect the hydraulic parts.
While the present invention has been described in connection with the specific embodiments illustrated in the drawings, they are merely illustrative, and the invention is not limited to these embodiments. It is to be understood that various equivalent modifications and variations of the embodiments can be made by a person having an ordinary skill in the art without departing from the spirit and scope of the present invention. Therefore, the true technical scope of the present invention should not be defined by the above-mentioned embodiments but should be defined by the appended claims and equivalents thereof.
INDUSTRIAL APPLICABILITY
As described above, the pressure control system for a construction machine in accordance with an embodiment of the present invention is advantageous in controlling the hydraulic pressure of a construction machine including an excavator or a loader. In addition, the set pressure of the relief valve is automatically boosted based on the pressure of the hydraulic system or the input value of the joystick by a user during the operation of the construction machine so that a loss of a hydraulic fluid that is relieved under the work condition of a high load can be reduced, thereby improving workability, and the set pressure of the relief valve can be maintained at the optimal level, thereby extending the lifespan of the hydraulic parts.
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The present invention relates to a hydraulic control system for construction machinery capable of variably adjusting a set pressure of a relief valve, which controls a set pressure of a hydraulic system, according to a value inputted by means of pressure in the hydraulic system or the manipulation of a joystick. The hydraulic control system comprises: a flow control valve installed in a passage between a hydraulic pump and a hydraulic actuator, for controlling the driving of the hydraulic actuator by being switched by a control signal according to the manipulation of the joystick; a main relief valve installed in a passage between an upstream-side discharge passage of the hydraulic pump and a hydraulic tank, for returning a working fluid to the hydraulic tank when a high load exceeding a set pressure occurs in the system; a pressure controlling means for controlling, either continuously or in stages, a set pressure of the main relief valve; a pressure sensing means for sensing a pressure at a discharge side of the hydraulic pump; and a controller for determining the value inputted by the manipulation of the joystick, and a required set pressure for the relief valve according to the system pressure sensed by the pressure sensing means, and then outputting a control signal to the pressure controlling means to enable a set pressure of the relief valve to be variably adjusted to a determined set pressure.
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CLAIM OF PRIORITY TO RELATED APPLICATION
This application claims priority to and is a continuation-in-part of copending U.S. utility application entitled, “An Electromagnetic Bandgap Structure For Isolation In Mixed-Signal Systems,” having Ser. No. 10/936,774, filed Sep. 8, 2004, which is entirely incorporated herein by reference.
This application claims priority to co-pending U.S. provisional application entitled “Design Methodologies In Mixed-Signal Systems With Alternating Impedance Electromagnetic Bandgap (AI-EBG) Structure” having Ser. No. 60/679,540, filed on May 10, 2005, which is entirely incorporated herein by reference.
TECHNICAL FIELD
The present disclosure is generally related to noise suppression/isolation for mixed-signal systems in which RF/analog and digital circuits exist together, filters, and more particularly, is related to tunable electromagnetic bandgap structures.
BACKGROUND
Radio frequency (RF) front-end circuits like low noise amplifiers (LNAs) need to detect low-power signals and are therefore extremely sensitive by nature. A large noise spike, either in or close to the operating frequency band of the device, can de-sensitize the circuit and destroy its functionality. To prevent this problem, all radio architectures include filters and other narrow band circuits, which prevent the noise in the incoming spectrum from reaching the LNA. However, there are no systematic ways to filter noise from other sources, such as noise coupling through the power supply and appearing at the output of the LNA, where it can degrade the performance of the downstream circuits.
The sensitivity of RF circuits to power supply noise has resulted in difficulties for integration of digital and RF/analog sub-systems on packaging structures. One typical approach to isolate the sensitive RF/analog circuits from the noisy digital circuits is to split the power plane or both power and ground planes. The gap in power plane or ground plane can partially block the propagation of electromagnetic waves. For this reason, split planes are usually used to isolate sensitive RF/analog circuits from noisy digital circuits. Although split planes can block the propagation of electromagnetic waves, part of the electromagnetic energy can still couple through the gap. Due to the electromagnetic coupling, this method only provides a marginal isolation (i.e., −20 dB to −60 dB) at high frequencies (i.e., above ˜1 GHz) and becomes ineffective as the sensitivity of RF circuits increases and operating frequency of the system increases. At low frequencies (i.e., below ˜1 GHz), split planes provide an isolation of −70 dB to −80 dB.
In addition, split planes sometimes require separate power supplies to maintain the same DC level, which is not cost-effective. Therefore, the development of a better noise isolation method is needed for good performance of a system having a RF/analog circuit and a digital circuit.
Furthermore, as systems become more compact, multiple power supplies become a luxury that the designer cannot afford. The use of ferrite beads have been suggested as a solution to these problems, enabling increased isolation as well as the use of a single power supply. However, due to the high sensitivity of RF circuitry, the amount of isolation provided by ferrite beads again tends to be insufficient at high frequencies.
Electromagnetic bandgap (EBG) structures have become very popular due to their enormous applications for suppression of unwanted electromagnetic mode transmission and radiation in the area of microwave and millimeter waves. EBG structures are periodic structures in which propagation of electromagnetic waves is not allowed in a specified frequency band. In recent years, EBG structures have been proposed to suppress simultaneous switching noise (SSN) in a power distribution network (PDN) in high-speed digital systems for antenna applications. These EBG structures have a thick dielectric layer (60 mils to 180 mils) that exists between the power plane and the ground plane. In addition, these EBG structures require an additional metal layer with via connections. Thus, these EBG structures are expensive solutions for printed circuit board (PCB) applications.
Accordingly, there is a need in the industry to address the aforementioned deficiencies and/or inadequacies.
SUMMARY
Alternating impedance electromagnetic bandgap (AI-EBG) structures, systems incorporating AI-EBG structures, and methods of making AI-EBG structures, are disclosed. A representative embodiment of a structure, among others, includes a first layer, wherein the first layer comprises a signal layer; a second layer disposed on a back side of the first layer, wherein the second layer comprises a dielectric layer; a third layer disposed on a back side of the second layer, wherein the third layer comprises a solid metal plane; a fourth layer disposed on a back side of the third layer, wherein the fourth layer comprises a dielectric layer; and a fifth layer disposed on a back side of the fourth layer, wherein the fifth layer comprises an alternating impedance electromagnetic bandgap (AI-EBG) plane.
The AI-EBG plane includes a plurality of first elements disposed on a first plane, each first element comprising a first metal layer, wherein each first element has a rectangular shape; and a second element connecting each first element to an adjacent first element at a position adjacent to the corner of the first element, the second element being disposed on the first plane, the second element comprising the first metal layer, wherein the first elements and second elements substantially filter electromagnetic waves to a stopband floor of about −60 dB to about −140 dB in a bandgap of about 100 MHz to about 50 GHz, having a width selected from about 1 GHz, 2 GHz, 3 GHz, 5 GHz, 10 GHz, 20 GHz, and 30 GHz, and having a center frequency positioned at a frequency from about 1 GHz to 37 GHz.
A representative method of fabricating an AI-EBG structure, among others, includes providing a first layer, wherein the first layer comprises a signal layer; disposing a second layer on a back side of the first layer, wherein the second layer comprises a dielectric layer; disposing a third layer on a back side of the second layer, wherein the third layer comprises a solid metal plane; disposing a fourth layer on a back side of the third layer, wherein the fourth layer comprises a dielectric layer; and disposing a fifth layer on a back side of the fourth layer, wherein the fifth layer comprises an alternating impedance electromagnetic bandgap (AI-EBG) plane.
Other structures, systems, methods, features, and advantages of the present disclosure will be, or become, apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional structures, systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1A illustrates a top view of one embodiment of a system having an AI-EBG structure. FIG. 1B illustrates a three-dimensional elevated, side view of the system having the AI-EBG structure.
FIG. 2 illustrates a top view of another embodiment of a system having a partial AI-EBG structure.
FIG. 3 illustrates a top view of another embodiment of a system having a hybrid AI-EBG structure.
FIGS. 4A through 4C illustrate embodiments of the structures including alternating impedance electromagnetic bandgap (AI-EBG) planes.
FIG. 5 illustrates a flow chart of a method of fabricating the structure in FIG. 4A .
FIG. 6 illustrates noise coupling in a mixed-signal system.
FIG. 7 illustrates a schematic of an embodiment of a three-dimensional (3-D) structure view of the AI-EBG structure.
FIG. 8 illustrates: (a) a schematic of a periodic pattern in one of power and ground planes in the AI-EBG structure, and (b) a unit cell in a periodic pattern in one of power and ground planes in the AI-EBG structure.
FIG. 9 illustrates an embodiment of the AI-EBG structure with alternating impedance.
FIG. 10 illustrates one-dimensional (1-D) equivalent circuits for 3 parts of an AI-EBG structure. In (a) a 1-D equivalent circuit for the metal patch including FR4 and the corresponding metal part of the other solid plane is illustrated. In (b) a 1-D equivalent circuit for the metal branch part including FR4 and the corresponding metal part of the other solid plane is illustrated. In (c) a 1-D equivalent circuit for the interface between a metal patch and a metal branch is illustrated.
FIG. 11 illustrates a two-dimensional (2-D) unit cell of the AI-EBG structure.
FIG. 12 illustrates an equivalent TL circuit for the unit cell in FIG. 11 in the y-direction.
FIG. 13 illustrates a dispersion diagram for the unit cell of the AI-EBG structure in FIG. 11 using transmission line network (TLN) method.
FIG. 14 illustrates: (a) a plane pair structure and (b) a unit cell and equivalent circuit (T and II models).
FIG. 15 illustrates an equivalent Π circuit for the unit cell including fringing and gap effects.
FIG. 16 illustrates: (a) a schematic of the simulated AI-EBG structure and (b) simulated results of transmission coefficient (S 21 ) for the AI-EBG structure in (a).
FIG. 17 illustrates simulated voltage magnitude distributions on the AI-EBG structure at different frequencies: (a) At 500 MHz. (b) At 1.5 GHz. (c) At 4 GHz. (d) At 7 GHz.
FIG. 18 illustrates the fabrication of AI-EBG structure. In (a) a cross section of fabricated AI-EBG structure is illustrated and in (b) a photo of a fabricated AI-EBG structure is shown.
FIG. 19 illustrates measured S-parameters of the AI-EBG structure.
FIG. 20 illustrates a model to hardware correlation for the AI-EBG structure.
FIG. 21 illustrates a cross section of the fabricated mixed-signal systems.
FIG. 22 illustrates a photo of the mixed-signal system containing the AI-EBG structure.
FIG. 23 illustrates a simulated transmission coefficient (S 21 ) between the LNA and FPGA in PDN with the AI-EBG structure.
FIG. 24 illustrates a measurement set-up for noise measurements.
FIG. 25 illustrates a measured output spectrum of the LNA: (a) illustrates when the FPGA is completely switched off and (b) illustrates when the FPGA is switched on.
FIG. 26 illustrates measured 7 th harmonic noise peaks at 2.1 GHz for the test vehicle with and without the AI-EBG structure.
FIG. 27 illustrates a measured LNA output spectrum for the test vehicles with and without the AI-EBG structure.
FIG. 28 illustrates a waveform measurement at two locations on the mixed-signal board.
FIG. 29 illustrates measured waveforms at two different locations for signal integrity analysis.
FIG. 30 illustrates a measured characteristic impedance profile of the first transmission line over the AI-EBG structure in the mixed-signal system. In (a) a characteristic impedance profile of the first transmission line over the AI-EBG structure is illustrated. In (b) a magnified characteristic impedance profile of the first transmission line over the AI-EBG structure is illustrated.
FIG. 31 illustrates an embodiment of a plane stack-up for avoiding possible problems related to signal integrity and EMI.
FIG. 32 illustrates a cross section of the three test vehicles: (a) test vehicle 1 is a microstrip line on a solid plane, (b) test vehicle 2 is a microstrip line on an AI-EBG structure, and (c) test vehicle 3 is a microstrip line on an embedded AI-EBG structure.
FIG. 33 illustrates a top view of the test vehicles.
FIG. 34 illustrates far field simulation results: (a) test vehicle 1 (a solid plane as a reference plane), (b) test vehicle 2 (an AI-EBG plane as a reference plane), and (c) test vehicle 3 (a solid plane in an embedded AI-EBG structure as a reference plane).
FIG. 35 illustrates a far field measurement set-up and results: (a) measurement set-up for far field measurement and (b) far field measurement results.
DETAILED DESCRIPTION
Structures and systems having alternating impedance electromagnetic bandgap (AI-EBG) structures or planes and methods of fabrication thereof are described. Embodiments of the structures (hereinafter “AI-EBG structures”) provide deeper stopband and wider stopband, which provides better noise suppression than other EBG structures. In addition, embodiments of the AI-EBG structure maintain signal integrity (e.g., maintaining signal integrity ensures signals are undistorted and do not cause problems to themselves, to other components in the system, or to other systems nearby) and limit electromagentic interference (EMI). Further, embodiments of the AI-EBG structure provide tunable isolation between RF/analog circuits and digital circuits in certain frequency bandgaps.
The AI-EBG structure can be used in mixed signal systems and high-speed digital systems. For example, the AI-EBG structures can be included in, but are not limited to, cellular systems, power distribution systems in mixed-signal package and board, power distribution systems in a high-speed digital package and board, power distribution networks in RF systems, and combinations thereof. The compact design of the AI-EBG structure is particularly well suited for devices or systems requiring minimization of the size of the structure.
In general, the AI-EBG structure includes a stacking structure that includes, but is not limited to, a signal layer, an AI-EBG plane, and a solid metal plane. The design methodology of the stacking of layers and planes provides an AI-EBG structure that operates in mixed-signal systems while maintaining signal integrity, reducing EMI, and reducing noise. By using the solid metal plane as the reference plane for the signal layer in mixed-signal systems, the AI-EBG structure substantially avoids signal integrity and EMI problems, while the AI-EBG plane suppresses noise.
The stacking configurations illustrated in FIGS. 4A through 4C show a number of embodiments employing the design methodology described herein to design AI-EBG structures that substantially avoid signal integrity and EMI problems and suppress noise. It is contemplated that other designs not shown in FIGS. 4A through 4C can be used to substantially avoid signal integrity and EMI problems and suppress noise, and that the design methodology described herein describes such embodiments.
In regard to the AI-EBG plane, the AI-EBG plane includes a plurality of first elements, where each first element is connected to another first element by a second element, thereby forming a continuous, two-dimensional, and periodic structure in the same dimensional plane. Unlike mushroom-type EBG structures, the AI-EBG structure is relatively simple and can be easily designed and fabricated using planar printed circuit board processes.
Although not intending to be bound by theory, the plurality of first elements can be etched in a power plane (or in a ground plane) and connected by the second elements etched in the same dimensional plane to form a distributed LC network (where L is inductance and C is capacitance). The second elements introduce additional inductance, while the capacitance is mainly formed by the first elements and the corresponding parts of the other solid plane. The resultant effect is substantial isolation of electromagnetic waves from one or more components positioned on the AI-EBG structures.
EBG structures in the two dimensional plane (i.e., xy plane) are desirable because vias are not required to interconnect components positioned in different dimensional planes. In addition, the design and fabrication are simple as compared to EBG structures having components positioned in different dimensional planes with vias and additional metal patch layers interconnecting the components. Standard planar printed circuit board (PCB) processes can be used to fabricate the structures of the present disclosure. For example, the systems having AI-EBG structures can be fabricated using a FR 4 process. In addition, the dielectric thickness can be thin (e.g., 1 mil about 4 mils) and thus lower costs.
The AI-EBG structures can be designed to have a stopband floor of about −40 dB to −140 dB, −50 dB to −140 dB, −60 dB to −140 dB, −80 dB to −140 dB, and −100 dB to −140 dB. In addition, the AI-EBG structure can be designed to have a bandgap that can range from about 100 MHz to 35 GHz, having widths of about 1 GHz, 2 GHz, 3 GHz, 5 GHz, 10 GHz, 20 GHz, and 30 GHz (e.g., about 500 MHz to 3 GHz, about 3 GHz to 8 GHz, and about 15 GHz to 50 GHz), depending on the stopband floor selected. Since the AI-EBG structure is tunable, the center frequency can be at a pre-selected frequency. In particular, the center frequency can be selected from a frequency from about 1 GHz to 37 GHz.
FIG. 1A illustrates a top view of one embodiment of a system having an AI-EBG structure 10 . The AI-EBG structure 10 has an AI-EBG plane that includes, but is not limited to, a plurality of first elements 12 continuously connected by a plurality of second elements 14 in the same dimensional plane. At a first location 16 and a second location 18 , the AI-EBG plane can also include, but is not limited to, various devices or circuits. At the first location 16 , the AI-EBG plane can include, but is not limited to, a port, an RF/analog circuit, and/or a digital circuit. At the second location 18 , the AI-EBG plane can include, but is not limited to, a port, an RF/analog circuit, and/or a digital circuit. In one embodiment, a digital circuit is located at the first location 16 , while an RF/analog circuit is located at the second location 18 .
The first element 12 and the second element 14 can be various shapes. The first elements 12 illustrated in FIG. 1A have square shapes and the second elements 14 illustrated in FIG. 1A also have square shapes. By having the first elements 12 and the second elements 14 each as the same shape, the AI-EBG plane is easy to design, fabricate, and analyze.
It should be noted that the first elements 12 and the second elements 14 can also be other structures that produce sections of high and low impedance. In particular, the first elements 12 and the second elements 14 can each independently be a shape such as, but not limited to, rectangular shapes, polygonal shapes, hexagonal shapes, triangular shapes, circular shapes, or combinations thereof.
The second element 14 can be attached to the first element 12 at various positions. In FIG. 1A , the second elements 14 are attached to the corners of the square first elements 12 . However, the second elements 14 can be attached at other positions on the perimeter of the first elements 12 , but are shown to be disposed on the edges of the first elements 12 for the best isolation. The simulation results using TMM and a conventional full-wave solver (SONNET) confirm that the second elements 14 disposed on the edges of the first elements 12 showed better isolation than that of the second elements 14 disposed on the centers of the first elements 12 .
FIG. 1B illustrates a three-dimensional view of the system having the AI-EBG structure 10 . The system having the AI-EBG structure 10 can include, but is not limited to, a AI-EBG plane 13 , a dielectric layer 15 , and a solid metal plane 17 . The AI-EBG plane 13 can be included in, but is not limited to, a ground plane or a power plane. For example, the AI-EBG plane 13 can be a power plane etched with first elements 12 and second elements 14 (as shown in FIG. 1B ), while the solid metal plane 17 can be a continuous metal layer acting as a ground plane.
The AI-EBG plane 13 can include, but is not limited to, copper (Cu), palladium (Pd), aluminum (Al), platinum (Pt), chromium (Cr), or combinations thereof. The AI-EBG plane 13 can be, but is not limited to, any material with a conductivity (σ c ) between about 1.0×10 6 S/m and about 6.1×10 6 S/m. The AI-EBG plane 13 can have, but is not limited to, a thickness between about 1 mil and 100 mils.
The dielectric layer 15 can be, but is not limited to, a dielectric material with a dielectric constant having a relative permittivity (ε r ) of about 2.2 to about 15, and/or a dielectric loss tangent (tan (δ)) of about 0.001 to about 0.3, and combinations thereof. The dielectric layer 15 can include, but is not limited to, FR4 ceramic, and combinations thereof. In general, FR4 is used as an insulating base material for circuit boards. FR4 is made from woven glass fibers that are bonded together with an epoxy. The board is cured using a combination of temperature and pressure that causes the glass fibers to melt and bond together, thereby giving the board strength and rigidity. “FR” stands for “Flame Retardant”. FR4 is also referred to as fiberglass boards or fiberglass substrates. The dielectric layer 15 can have, but is not limited to, a thickness between about 1 mil and about 100 mils.
The solid metal plane 17 can be included in, but is not limited to, a ground plane or a power plane. The solid metal plane 17 can include, but is not limited to, Cu, Pd, Al, Pt, Cr, or combinations thereof. The solid metal plane 17 can be, but is not limited to, a material with a conductivity (σ c ) between about 1.0×10 6 S/m and about 6.1×10 6 S/m. The solid metal plane 17 can have, but is not limited to, a thickness between about 1 mil and 10 mils.
In general, the length and width of the AI-EBG structure 10 can vary depending on the application. The AI-EBG structure 10 can be fabricated to a length and a width to accommodate consumer and commercial electronics systems.
FIG. 2 illustrates another embodiment of a system having an AI-EBG structure 20 . The AI-EBG structure 20 includes, but is not limited to, a plurality of first elements 22 continuously connected by a plurality of second elements 24 . The plane elements 29 a and 29 b can be, but are not limited to, a continuous metal layer. At a first location 26 and a second location 28 , the system having the AI-EBG structure 20 can also include, but is not limited to, various devices or circuits. At the first location 26 , the system having the AI-EBG structure 20 can include, but is not limited to, a port, a RF/analog circuit, and/or a digital circuit. At the second location 28 , the system having the AI-EBG structure 20 can include, but is not limited to, a port, a RF/analog circuit, and/or a digital circuit. In one embodiment, a digital circuit is located at the first location 26 , while an RF/analog circuit is located at the second location 28 .
FIG. 3 illustrates another embodiment of a system having an AI-EBG structure 30 . The AI-EBG structure 30 includes, but is not limited to, a plurality of first elements 32 a and 32 b continuously connected by a plurality of second elements 34 . The first elements 32 a are smaller in size than the first elements 32 b . At a first location 36 and a second location 38 , the system having the AI-EBG structure 30 can also include, but is not limited to, various devices or circuits. At the first location 36 , the system having the AI-EBG structure 30 can include, but is not limited to, a port, a RF/analog circuit, or a digital circuit. At the second location 38 , the system having the AI-EBG structure 30 can include, but is not limited to, a port, an RF/analog circuit, or a digital circuit. In one embodiment, a digital circuit is located at the first location 36 , while an RF/analog circuit is located at the second location 38 .
Using the AI-EBG structure 30 enables the structure to obtain very wide bandgap (e.g., −40 dB bandgap ranging between 500 MHz and 10 GHz). For example, the larger first elements 32 b and the second elements 34 can produce a bandgap from about 500 MHz to 3 GHz (−40 dB bandgap), while smaller first elements 32 a and the second elements 34 produce a bandgap from about 3 GHz to 10 GHz (−40 dB bandgap). Thus, a AI-EBG structure can produce an ultra wide bandgap. The ratio between the first element and the second elements could be, but is not limited to, from about 4 to 300.
FIGS. 4A through 4C illustrate embodiments of the AI-EBG structure having various stack configurations. FIG. 4A illustrates structure A 40 including, but not limited to, a signal layer 42 , a dielectric layer 44 , a solid metal plane 46 , a dielectric layer 48 , and a AI-EBG plane 52 . Structure A 40 substantially avoids signal integrity problems, EMI problems, and suppresses noise when used in mixed-signal systems. Variations of this stack configuration (combinations of layers/planes or multiple stacks of structure A 40 ) can be used to design AI-EBG structures that substantially avoid signal integrity and EMI problems and suppresses noise (AI-EBG plane) in a mixed-signal system.
The signal layer 42 is positioned on the top of the dielectric layer 44 . The solid metal plane 46 is positioned on the bottom (back side) of the dielectric layer 44 . The dielectric layer 48 is positioned on the bottom of the solid metal plane 46 . The AI-EBG plane is positioned on the bottom of the dielectric layer 48 .
Each layer or plane can be a ground plane or a power plane, and the selection of the type of layer or plane can be determined based, at least in part, on the product that the AI-EBG structure is incorporated into and the desired characteristics of the AI-EBG structure.
The dielectric layer, the solid metal plane, and the AI-EBG plane have been described in detail above. The signal layer 42 is a partial metal layer. The metal can include, but is not limited to, Cu, Pd, Al, Pt, Cr, or combinations thereof. The signal layer 42 includes transmission lines, which send signals from one place to the other place. By using the solid metal plane as the reference plane for the signal layer in mixed-signal systems, the stacking of structure A 40 substantially avoids signal integrity and EMI problems, while the AI-EBG plane suppresses noise.
FIG. 4B illustrates structure B 60 having a signal layer 62 , a dielectric layer 64 , a solid metal plane 66 , a dielectric layer 68 , a AI-EBG plane 72 , a dielectric layer 74 , a solid metal plane 76 , a dielectric layer 78 , and a signal layer 82 . The dielectric layer, the solid metal plane, the AI-EBG plane, and the signal layer have been described in detail above. When used in mixed-signal systems, the stacking of structure B 60 substantially avoids signal integrity and EMI problems, and the AI-EBG plane 72 suppresses noise.
The signal layer 62 is positioned on the top of the dielectric layer 64 . The solid metal plane 66 is positioned on the bottom of the dielectric layer 64 . The dielectric layer 68 is positioned on the bottom of the solid metal plane 66 . The AI-EBG plane 72 is positioned on the bottom of the dielectric layer 68 . The dielectric layer 74 is positioned on the bottom of the AI-EBG plane 72 . The solid metal plane 76 is positioned on the bottom of the dielectric layer 74 . The dielectric layer 78 is positioned on the bottom of the solid metal plane 76 . The signal layer 82 is positioned on the bottom of the dielectric layer 78 .
Each layer or plane can be a ground plane or a power plane, and the selection of the type of layer or plane can be determined based, at least in part, on the product that the AI-EBG structure is incorporated into and the desired characteristics of the AI-EBG structure.
FIG. 4C illustrates structure C 90 having a signal layer 92 , a dielectric layer 94 , a solid metal plane 96 , a dielectric layer 98 , a AI-EBG plane 102 , a dielectric layer 104 , a solid metal plane 106 , a dielectric layer 108 , a signal layer 112 , a dielectric layer 114 , a solid metal plane 116 , a dielectric layer 118 , a AI-EBG plane 122 , a dielectric layer 124 , a solid metal plane 126 , a dielectric layer 128 , and a signal layer 132 . The dielectric layer, the solid metal plane, the AI-EBG plane, and the signal layer have been described in detail above. The stacking structure C 90 substantially avoids signal integrity and EMI problems, while the AI-EBG plane suppresses noise, when used in mixed-signal systems.
The signal layer 92 is positioned on the top of the dielectric layer 94 . The solid metal plane 96 is positioned on the bottom of the dielectric layer 94 . The dielectric layer 98 is positioned on the bottom of the solid metal plane 96 . The AI-EBG plane 102 is positioned on the bottom of the dielectric layer 98 . The dielectric layer 104 is positioned on the bottom of the AI-EBG plane 102 . The solid metal plane 106 is positioned on the bottom of the dielectric layer 104 . The dielectric layer 108 is positioned on the bottom of the solid metal plane 106 . The signal layer 112 is positioned on the bottom of the dielectric layer 108 . The dielectric layer 114 is positioned on the bottom of the signal layer 112 . The solid metal plane 116 is positioned on the bottom of the dielectric layer 114 . The dielectric layer 118 is positioned on the bottom of the solid metal plane 116 . The AI-EBG plane 122 is positioned on the bottom of the dielectric layer 108 . The dielectric layer 124 is positioned on the bottom of the AI-EBG plane 122 . The solid metal plane 126 is positioned on the bottom of the dielectric layer 124 . The dielectric layer 128 is positioned on the bottom of the solid metal plane 126 . The signal layer 132 is positioned on the bottom of the dielectric layer 128 .
Each layer or plane can be a ground plane or a power plane, and the selection of the type of layer or plane can be determined based, at least in part, on the product that the AI-EBG structure is incorporated into and the desired characteristics of the AI-EBG structure.
FIG. 5 illustrates a flow diagram 140 of the fabrication of the AI-EBG structure 40 in FIG. 4A . It should be noted that the steps of the flow diagram could be conducted in a different order. Also, portions of the AI-EBG structure 40 can be formed separately and then combined. For example, the signal layer 42 , dielectric layer 44 , and solid metal plane 46 can be formed separately from the dielectric layer 48 and the AI-EBG plane 52 , and then these portions combined. It should be noted that AI-EBG structures 60 and 90 could be fabricated in a similar manner.
In block 142 , a signal layer 42 is provided. In block 144 , a dielectric layer 44 is disposed on the backside of the signal layer 42 . In block 146 , a solid metal plane 46 is disposed on the backside of the dielectric layer 44 . In block 148 , a dielectric layer 48 is disposed on the backside of the solid metal plane 46 . In block 152 , an AI-EBG plane is disposed on the back of the dielectric layer 48 .
It should be noted that ratios, amounts, and other numerical data may be expressed herein in a range format. It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a concentration range of “about 0.1% to about 5%” should be interpreted to include not only the explicitly recited concentration of about 0.1 wt % to about 5 wt %, but also include individual concentrations (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.5%, 1.1%, 2.2%, 3.3%, and 4.4%) within the indicated range.
It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the disclosure. For example, the systems having the AI-EBG structures can be fabricated of multiple materials. Therefore, many variations and modifications may be made to the above-described embodiment(s) of the disclosure without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.
Now having described the embodiments of the systems having the AI-EBG structures in general, example 1 describes some embodiments of the AI-EBG structure that is described in J. Choi, V. Govind, M. Swaminathan, K. Bharath, D. Chung, D. Kam, J. Kim, “Noise suppression and isolation in mixed-signal systems using alternating impedance electromagnetic bandgap (AI-EBG),” submitted to IEEE Transactions on Electromagnetic Compatibility , September 2005.
While embodiments of systems having the AI-EBG structures are described in connection with Example 1 and the corresponding text and figures, there is no intent to limit embodiments of the structures to these descriptions. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of embodiments of the present disclosure.
EXAMPLE 1
In this Example, a two-layer AI-EBG structure has been discussed. Along with reducing the layer count, this structure does not require any blind vias. Moreover, this structure provides better isolation level as compared to other EBG structures that have been proposed so far. In this Example, the proposed AI-EBG structure has been investigated with a mixed-signal test vehicle to quantify the isolation levels that are achievable.
Noise Coupling in Mixed-Signal Systems
With the evolution of technologies, mixed-signal system integration is becoming necessary for combining heterogeneous functions such as high-speed processors, radio frequency (RF) circuits, memory, microelectromechanical systems (MEMS), sensors, and optoelectronic devices. This kind of integration is necessary for enabling convergent Microsystems that support communication and computing capabilities in a tightly integrated module. A major bottleneck with such heterogeneous integration is the noise coupling between the dissimilar blocks constituting the system. As an example, the noise generated by high-speed digital circuits can couple through the power distribution network (PDN) and transfer to sensitive RF circuits, completely destroying the functionality of noise-sensitive RF circuits. FIG. 6 shows the noise coupling mechanism due to electromagnetic (EM) waves in a mixed-signal system including RF and digital circuits. The time-varying current flowing through a via due to the switching of digital circuits can cause the excitation of EM waves. Since a power/ground plane pair used to supply power to the switching circuits behaves as a parallel-plate waveguide at high frequencies, the EM wave can propagate between the power/ground plane pair and couple to the RF circuit, causing the failure of the RF circuit. To prevent this noise coupling, traditional isolation techniques have used split planes with multiple power supplies, split planes and ferrite beads with a single power supply, and split power islands.
All these methods have two fundamental problems, namely, a) they provide poor isolation in the −20 dB to −60 dB range above 1 GHz and b) they provide narrow band capability. Hence, the development of better noise isolation methods for the integration of digital and RF functions is necessary. One method for achieving high isolation over broad frequency range is through the use of electromagnetic band gap (EBG) structures. EBG structures are periodic structures that suppress wave propagation in certain frequency bands while allowing it in others. For power delivery network, EBG structures can be constructed by patterning one of the power and ground planes. In this Example, a novel EBG structure based on the alternating impedance (AI-EBG) concept is discussed for use in power delivery networks.
Design of AI-EBG Structure
The AI-EBG structure is a metallo-dielectric EBG structure that includes two metal layers separated by a thin dielectric material, as shown in FIG. 7 . In the AI-EBG structure, one metal layer has only a periodic pattern that is a two-dimensional (2-D) rectangular lattice with each element including a metal patch with four connecting metal branches, as shown in FIG. 8( a ).
This EBG structure can be realized with metal patches etched in the power plane (or in the ground plane depending on design) connected by metal branches to form a distributed LC network (where L is inductance and C is capacitance). In this structure, a metal branch introduces additional inductance while the metal patch and the corresponding solid plane form the capacitance. The unit cell of this EBG structure is shown in FIG. 8( b ). The location of metal branches on edges of the metal patch was optimized to ensure maximum wave destructive interference, which results in excellent isolation in the stopband frequency range. It is important to note that the shape of the metal patch and branch can be shapes including, but not limited to, a square, or a rectangle. FIG. 8( a ) represents one layer of the plane pair where the other layer (not shown) is a solid plane.
The EBG structure formed in FIG. 7 does not require blind vias and the dielectric thickness can be very thin (1 mil˜4 mils), which results in a low-cost process. Hence, the AI-EBG structure has the advantage of being simple and can be easily designed and fabricated using standard printed circuit board (PCB) processes without the need for vias and only using two metal layers, as compared to the mushroom-type EBG structure, which requires three metal layers and blind vias.
Equivalent Circuit Representation of AI-EBG Structure
The EBG structure presented in this Example can be called as the alternating impedance EBG (AI-EBG) since it includes alternating sections of high and low characteristic impedances, as shown in FIG. 9 . The EBG structure in FIG. 7 is a two-dimensional (2-D) parallel-plate waveguide (or 2-D transmission line) with alternating perturbation of its characteristic impedance. The metal patch on the top layer and the corresponding solid plane on the bottom layer can be represented as a parallel-plate waveguide having low characteristic impedance, while the metal branch and the corresponding solid plane pair can be treated as a parallel-plate waveguide having high characteristic impedance. This is because the characteristic impedance in a parallel-plate waveguide for a TEM mode (dominant mode in plane pairs with thin dielectrics), is given by the following formula:
Z o = η d w = L C ( 1 )
where η is intrinsic impedance of the dielectric, d is the dielectric thickness, w is the width of the metal, L and C are inductance and capacitance per unit length. Since w patch >w branch and characteristic impedances are inversely proportional to w, Z o of the metal patch is lower than Z o of the metal branch. Due to this impedance perturbation, wave propagation can be suppressed in certain frequency bands.
The AI-EBG dispersion characteristics can also be explained using filter theory. FIG. 10 shows the three-dimensional (3-D) schematic of the EBG structure with 3 equivalent circuits described. FIG. 10( a ) shows the one-dimensional (1-D) T-type equivalent circuit of the metal patch including dielectric and the corresponding solid plane and FIG. 10( b ) shows the 1-D equivalent circuit of the metal branch including dielectric and the corresponding solid plane. In this figure, C branch is very small and can be neglected due to the size of the metal branch. In addition to the LC elements, small parasitic reactances at the interface between the metal patch and branch exist, as shown in FIG. 10( c ) due to discontinuities caused by the change in width. From FIG. 10 , it is clear that the resulting two-dimensional LC network representing AI-EBG structure is a low-pass filter (LPF), which has been verified through simulations and measurements in the following sections.
Propagation Characteristics of AI-EBG Structure
To understand the dispersion characteristics, the transmission line network (TLN) method has been used in this Example. The TLN approach is based on standard periodic analysis for one dimensional symmetric unit cells. FIG. 11 shows the unit cell for the two-dimensional AI-EBG structure. It includes two metal layers with a metal patch on the top layer, four metal branches on the top layer, and a ground plane on the bottom.
For clarity, the structure is assumed periodic along the y direction with perfect magnetic walls along the x directed boundaries. The structure is assumed infinite along y direction with wave propagation along the y axis. This enables the modeling and visualization using TLN analysis, while retaining sufficient generality to describe the unique dispersion characteristics of the AI-EBG structure.
Using the equivalent transmission line circuit in FIG. 12 , the transfer matrix for the unit cell can be written as:
T Unit — Cell(B2) =T L/2 T TL T C T TL T L/2 (2).
The first and fifth matrix in (2), T L/2 , represents the equivalent series inductance due to metal branch on the edge of metal patch. The value of the series inductance is halved (L/2) to account for symmetry of the structure. The second and fourth matrix, T TL , represents the transfer matrix for a uniform section of transmission line of length d/2. The third matrix, T C , represents the equivalent shunt capacitance between the metal patch and the corresponding ground plane.
Using ABCD matrix, T Unit — Cell(B2) can be expressed as
T Unit_Cell ( BZ ) = [ 1 Z branch 2 0 1 ] [ cos kd 2 jZ 0 sin kd 2 jY 0 sin kd 2 cos kd 2 ] [ 1 0 Y patch 1 ] [ cos kd 2 jZ 0 sin kd 2 jY 0 sin kd 2 cos kd 2 ] [ 1 Z branch 2 0 1 ] ( 3 )
where Z branch =jωL branch , kd=phase delay of transmission line segment, k=2πf√{square root over (με)}, d is the length of a unit cell, Y patch =jωC patch , Z o is the characteristic impedance of the transmission line segment, Y o is the characteristic admittance of the transmission line segment, ω is the angular frequency given by ω=2πf, f is the frequency and μ and ε are the permeability and permittivity of the dielectric material.
After some calculations, (3) becomes:
T
Unit_Cell
(
BZ
)
=
[
A
BZ
B
BZ
C
BZ
D
BZ
]
where
A
BZ
=
cos
2
kd
2
(
1
+
ZY
2
)
-
Z
o
Y
o
sin
2
kd
2
+
j
sin
kd
2
cos
kd
2
(
ZY
o
+
Z
o
Y
)
,
B
BZ
=
cos
2
kd
2
(
1
+
Z
2
Y
4
)
-
sin
2
kd
2
(
ZZ
o
Y
o
+
Z
o
2
Y
)
+
j
sin
kd
2
cos
kd
2
(
Z
2
Y
2
+
Z
o
ZY
+
2
Z
o
)
,
C
BZ
=
Y
cos
2
kd
2
+
j2Y
o
sin
2
kd
2
cos
kd
2
,
D
BZ
=
cos
2
kd
2
(
1
+
ZY
2
)
-
Z
o
Y
o
sin
2
kd
2
+
jsin
kd
2
cos
kd
2
(
ZY
o
+
Z
o
Y
)
,
Z
=
Z
branch
and
Y
=
Y
patch
.
(
4
)
By combining the ABCD matrix of the Brillouin zone unit cell, T Unit — Cell(B2) , with Floquet's theorem, which relates the voltage and current between the nth terminal (input and n+1th terminal (output of the unit cell) through e −γd , the following is
[ V n I n ] = T Unit_Cell ( BZ ) [ V n + 1 I n + 1 ] = [ A BZ B BZ C BZ D BZ ] = ⅇ γ d [ V n + 1 I n + 1 ] ( 5 )
where γ=α+jβ is the complex propagation constant, α is the attenuation constant, and β is the phase constant.
Based on a nontrivial solution for (5), the following analytic dispersion equation for the AI-EBG structure can be obtained as:
cos
β
d
=
Z
branch
Y
patch
2
cos
2
kd
2
+
cos
kd
+
j
sin
kd
2
(
Z
branch
Y
0
+
Z
0
Y
patch
Z
0
Y
0
)
.
(
6
)
FIG. 13 shows the dispersion diagram using (6) for the unit cell of the AI-EBG structure in FIG. 11 . As shown in FIG. 13 , the dispersion diagram includes layers of alternating passbands and stopbands. In this dispersion diagram, the first mode is a slow-wave TM mode that is tightly bound to the surface. It starts as a forward propagating TEM mode at very low frequency, and transits to a forward propagating TM surface wave. The group velocity (dω/dβ) of this mode is positive and its phase velocity (ω/β) is much less than the speed of light, which indicates that this mode is forward propagating as a slow-wave. The second mode is a backward mode since it has a negative group velocity. The third mode is a forward propagating TE mode. In the dispersion diagram, the AI-EBG structure, like other periodic structures, supports slow-wave propagation and has passband and stopband characteristics similar to those of filters.
Modeling of AI-EBG Structure
This section describes the modeling of the AI-EBG structure for extracting the S-parameters and computing voltage distributions. The full-wave EM solvers can be used to analyze EBG structures, but they are computationally expensive due to the grid size required. So, there is a need for efficient methods for modeling EBG structures with reasonable simulation time and good accuracy. The transmission matrix method (TMM) is a good candidate for analyzing the AI-EBG structure since it has been successfully applied to complex power delivery networks elsewhere. The good model to hardware correlation for a realistic PDN in packages and boards has been verified elsewhere.
Power/ground planes can be divided into unit cells, as shown in FIG. 14( a ), and represented using a lumped element model for each cell. The lumped element model parameters are computed from the physical structure. Each cell includes an equivalent circuit with R, L, C, and G components, as shown in FIG. 14( b ) for a rectangular structure. Each unit cell can be represented using either a T or Π model, as shown in the FIG. 14( b ). The equivalent circuit parameters for a unit cell can be derived from quasi-static models, provided the dielectric separation (d) is much less than the metal dimensions (a, b), which is true for a power/ground pair.
From the lateral dimension of a unit cell (w), separation between planes (d), dielectric constant (ε), loss tangent of dielectric (tan (δ), metal thickness (t), and metal conductivity (σ c ), the equivalent circuit parameters of a unit cell can be computed from the following equations:
C
=
ɛ
o
ɛ
r
w
2
d
,
L
=
μ
o
d
,
R
DC
=
2
σ
c
t
,
R
AC
=
2
π
f
μ
o
σ
c
(
1
+
j
)
,
and
G
d
=
ω
C
tan
(
δ
)
.
(
7
)
In the above equation, ε o is the permittivity of free space, μ o is the permittivity of free space, and ε r is the relative permittivity of the dielectric. The parameter R DC is the resistance of both the power and ground planes for a steady DC current, where the planes are assumed to be of uniform cross-section. The AC resistance R AC accounts for the skin effect on both conductors. The shunt conductance G d represents the dielectric loss in the material between planes.
In order to increase accuracy of the simulation, it is necessary to extend the basic model described above with circuit models for edge and gap effects. It is critical to model these effects to obtain accurate bandwidth and isolation levels in S parameter simulation. Edge effects can be modeled by adding an LC network to all the edges of the AI-EBG structure to model the fringing fields. The total capacitance (C T ) including fringing capacitance (C f ) for the edge cells of the AI-EBG structure can be calculated by employing the empirical formula for the per unit length capacitance of a microstrip line given by:
C T = ɛ eff [ ( W d ) + 0.77 + 1.06 ( W d ) 0.25 + 1.06 ( t h ) 0.5 ] ,
where ɛ eff = ɛ r + 1 2 + ɛ r - 1 2 1 1 + 12 d W
is the effective dielectric ( 8 )
constant, W is the metal line width, d is the dielectric thickness and t is the metal thickness. In (8), the first term is for the parallel-plate capacitance, and the other three terms in (8) accounts for fringing capacitance. In order to maintain a physical phase velocity, the per unit length inductance must be reduced from the parallel-plate inductance in accordance with
√{square root over (LC)}=√{square root over (με)}. (9)
This reduction is accomplished by adding an inductance between two adjacent nodes on the edge of the AI-EBG structure. Gap coupling can be modeled by including a gap capacitance, C g , between nodes across a gap in two metal patches in the AI-EBG structure. The gap capacitance was extracted from a 2-D solver such as Ansoft Maxwell™. For example, the gap capacitance per unit length extracted from Ansoft Maxwell™ for the AI-EBG structure in FIG. 16( a ) was 5.5 pF/m. FIG. 15 shows the updated equivalent II circuit for the unit cell including fringing and gap capacitances. It is important to note that the locations of the fringing and gap capacitances in the unit cell depend on the location of the unit cell in the AI-EBG structure. Once the unit cell equivalent circuits are available, these are converted to ABCD matrices and efficiently solved using TMM.
The test structure used was a two metal layer board with size 9.5 cm by 4.7 cm in size. In this example, the size of the metal patch was 1.5 cm×1.5 cm and the size of the metal branch was 0.1 cm×0.1 cm. The dielectric material of the board was FR4 with a relative permittivity, ε r =4.4, the conductor was copper with conductivity, σ c =5.8×10 7 S/m, and dielectric loss tangent was tan (δ)=0.02. The copper thickness for power plane and ground plane was 35 μm and dielectric thickness was 2 mils. A unit cell size of 0.1 cm×0.1 cm, which corresponds to an electrical size of λ/14.3 at 10 GHz, was used for approximating the structure. Port 1 was placed at (0.1 cm, 2.4 cm) and port 2 was located at (9.4 cm, 2.4 cm) with the origin (0 cm, 0 cm) lying at the bottom left corner of the structure, as shown in FIG. 16( a ). The transmission coefficient between two ports, S 21 , was computed by TMM and is shown in FIG. 16( b ). This result shows an excellent stopband floor (−120 dB) and broad stopband (over 8 GHz for −40 dB bandgap). This simulation result is well correlated with the dispersion results in FIG. 13 .
TMM was also used to obtain voltage variation on the AI-EBG structure in FIG. 16( a ). First, the transfer impedances from the input port to all locations on the power/ground planes were computed using TMM. Then, a 10 mA current source was applied between power and ground planes on the input port that is port 1 in FIG. 17( a ) to obtain the voltage distribution across the AI-EBG structure. FIG. 17( a - d ) are the simulated color scale voltage magnitude distributions on the AI-EBG structure at 500 MHz, 1.5 GHz, 4 GHz and 7 GHz. The voltage variation is represented by a color contrast in these figures. The unit in the color bars in FIG. 17 is [V]. Isolation is desirable between port 1 and port 2 in this example. FIG. 17( a ) shows that the AI-EBG structure does not provide good isolation at 500 MHz since 500 MHz is a frequency in passband. FIG. 17( b ) shows the voltage distribution on the AI-EBG structure at 1.5 GHz, which is still a frequency in passband. In contrast, a voltage distribution in FIG. 17( c ) shows excellent isolation since voltage variation is observed only in few metal patches around the metal patch containing port 1 . This frequency, 4 GHz, corresponds to around the stopband center frequency in the first stopband for the AI-EBG structure in FIG. 16 . It is important to note that noise generated by the current source on the input port can not propagate to the metal patches in the fourth, fifth, sixth columns in the AI-EBG structure at 4 GHz, which means that noise generated by digital circuits can not propagate to the RF circuits located at port 2 in FIG. 16( a ). Finally, voltage variation across the whole AI-EBG structure is again observed at 7 GHz, as can be seen in FIG. 17( d ), which represents the passband.
Model to Hardware Correlation
To verify the simulated results, the AI-EBG structures discussed in this Example were fabricated using standard PCB processes. FIG. 18( a ) shows the cross section of the fabricated structure. The top layer is a metal layer with AI-EBG pattern, and the second metal layer is a continuous solid plane. The dielectric material between these two metal layers is FR4 with a relative permittivity, ε r =4.4, the conductor is copper with conductivity, σ c =5.8×10 7 S/m, and the dielectric loss tangent is tan (δ)=0.02. The bottom layer is a FR4 core layer for mechanical support.
The S-parameter measurements were carried out using an Agilent 8720 ES vector network analyzer (VNA). FIG. 19 shows S-parameter results for one of the fabricated AI-EBG structures. In this case, the size of the metal patch was 1.5 cm×1.5 cm, and the size of the metal branch was 0.3 mm×0.3 mm. The entire structure size was 9.15 cm×4.56 cm. The measured S 21 shows a very deep and wide bandgap (over 8 GHz for −40 dB bandgap), and S 21 reached the sensitivity limit (−80 dB˜−100 dB) of the VNA used in the frequency range from 2.2 GHz to 4.5 GHz. The modeling results were compared with the measurement result in FIG. 20 , which shows reasonable agreement. The discrepancy between modeling and measurement is due to the sensitivity limit of the VNA in the stopband.
Noise Suppression and Isolation in Mixed-Signal System
In this section, the design, fabrication, and measurement of mixed-signal systems containing the AI-EBG structure in the power delivery network has been demonstrated. The results have been compared to a similar system with a regular power delivery network.
Design and Fabrication: To verify the use of the AI-EBG based scheme for mixed-signal noise suppression, a test vehicle containing an FPGA driving a 300 MHz bus with an integrated low noise amplifier (LNA) operating at 2.13 GHz was designed and fabricated on an FR4 based substrate. FIG. 21 shows the cross section of the fabricated mixed-signal test vehicle. The board is a three metal layer PCB that is 10.8 cm by 4.02 cm. The first metal layer is a signal layer, the second metal layer is a ground layer (Gnd), and the third metal layer is a power layer (Vdd). The AI-EBG structure was located on the ground layer in the test vehicle. The dielectric material in the PCB was FR4 with a relative permittivity, ε r =4.4 and dielectric loss tangent tan (δ)=0.02. The metallization used was copper with conductivity, σ c =5.8×10 7 S/m. The dielectric thickness between metal layers was 5 mils, with a bottom dielectric layer thickness of 28 mils. The bottom dielectric layer was used for mechanical support. FIG. 22 shows the photograph of the fabricated mixed-signal system containing the AI-EBG structure. The LNA was used as the noise sensor since it is the most sensitive device in an RF receiver. Noise generated in the FPGA couples to the LNA through the power distribution network. In the fabricated test vehicle, the size of the metal patch and metal branch used in the EBG structure was 2 cm×2 cm and 0.2 mm×0.2 mm, respectively. FIG. 23 shows the transmission coefficient (S 21 ) between FPGA and LNA, which was simulated using transmission matrix method (TMM). In FIG. 23 , S 21 shows a very deep stopband (˜−100 dB), which is required to suppress harmonic noise peaks generated by the digital circuits in the FPGA.
Measurements: FIG. 24 shows the measurement set-up for noise measurements. The AI-EBG-based common power distribution system was used for supplying power (3.3 V) to the RF and FPGA ICs. For comparison, a test vehicle similar to FIG. 22 was also fabricated without the AI-EBG structure.
In the measurements, the FPGA was programmed as four switching drivers using Xilinx software. The input terminal of the LNA was grounded to detect only noise from the FPGA through the PDN. The output terminal of the LNA was connected to a HP E4407B spectrum analyzer to observe noise from the FPGA.
FIG. 25 shows the measured output spectrum of the LNA for the test vehicle without the AI-EBG structure. With the FPGA completely switched off, the output spectrum is clean and contains only low frequency noise, as shown in FIG. 25( a ). However, when the FPGA is switched on with four switching drivers, the output spectrum exhibits a large number of noise components, as shown in FIG. 25( b ), at the output of the LNA. As can be seen in FIG. 25( b ), the noise components are harmonics of the FPGA clock frequency, which is at 300 MHz. In this diagram, the 7 th harmonic of the 300 MHz FPGA clock (at 2.1 GHz) lies close to the frequency of operation of the LNA, potentially degrading its performance. Hence, the 7 th harmonic noise peak should be suppressed for good LNA functionality. With the AI-EBG structure integrated into the ground plane, it is possible to suppress this harmonic noise peak. FIG. 26 shows the measured the LNA output spectrum around 2.1 GHz for the test vehicles with and without the AI-EBG structure. The 7 th harmonic noise peak at 2.1 GHz has been suppressed from −58 dBm to −88 dBm using the AI-EBG structure, which shows the ability of the AI-EBG structure for excellent noise suppression. It should be noted that −88 dBm is the noise floor in this measurement, which means that the 7 th harmonic noise peak due to the FPGA has been suppressed completely. FIG. 27 shows the measured LNA output spectrum from 50 MHz to 3 GHz for the test vehicles with and without the AI-EBG structure. The harmonic noise peaks from 2 GHz to 3 GHz have been suppressed completely using the AI-EBG structure. This frequency range (from 2 GHz to 3 GHz) corresponds to a stopband with −100 dB isolation level, as shown earlier in FIG. 23 . As can be observed, the AI-EBG based scheme shows very efficient suppression of noise propagation from the digital circuits into RF circuits in integrated mixed-signal systems.
Signal Integrity Analysis
The power delivery network needs to function along with the signal lines for high-speed transmission. Since the power and ground planes carry the return currents for the signal transmission lines, the impact of AI-EBG structure in signal transmission needs to be analyzed, which is the focus of this section.
Time Domain Waveforms: Since the AI-EBG plane (i.e., the plane with the AI-EBG pattern) is used as a reference plane for signal lines in the stack-up shown in FIG. 21 , the gaps in the AI-EBG structure function as discontinuities, causing degradation in the waveform. In a solid plane, return currents for high-speed transmission follow the path of least inductance. The lowest inductance return path lies directly under a signal line, which minimizes the loop area between the outgoing and returning current path.
To better understand signal quality, signal waveforms at the output of the FPGA and the far end of the transmission line were measured. These two locations are shown in FIG. 28 . The signal from the FPGA propagates along a transmission line. FIG. 29 shows the measurement results at both locations at 100 MHz. In this figure, two signal waveforms were overlapped to compare differences between them. In this case, there is no serious signal integrity problem since slopes of signal waveforms are almost the same. But the signal waveform at the far end of the transmission line has larger amplitude as compared to the output of the FPGA.
To investigate this phenomena, time domain reflectometry (TDR) measurements were performed to measure the characteristic impedance of the transmission line. In the TDR measurements, an injected voltage pulse propagates down the signal line, reflects off the discontinuity, and then returns to form a pulse on the oscilloscope. FIG. 30( a ) shows the measured characteristic impedance profile for one of four transmission lines used in the test vehicle. For this measurement, cascade microprobes were used for probing the pad at the end of the first transmission line. FIG. 30( b ) shows the magnified impedance profile for the device under test (DUT). In this figure, discontinuities in the impedance profile were observed. Each change in characteristic impedance causes the TDR trace to bump up or down to a new impedance level. Increasing impedance implies increased inductance, decreased capacitance, or both. Conversely, decreasing impedance implies increased capacitance, decreased inductance, or both. In FIG. 30( b ), the first discontinuity is caused by the first gap in the EBG structure, which is an inductive discontinuity, as can be seen in FIG. 30 . The inductive discontinuity is followed by a lower impedance transmission line due to the extra capacitance caused by the transmission line traversing a metal patch. Since an injected signal passes over five gaps before it arrives at the FPGA, there are five discontinuities along the signal path, as shown in FIG. 30( b ).
Design Methodology: Since the AI-EBG plane is used as a reference plane for signal lines, it can cause signal integrity problems. The best solution for avoiding this signal integrity problem is to use a solid plane as a reference plane, rather than the AI-EBG plane. For example, in FIG. 21 , the AI-EBG plane should be located on power layer (3 rd metal layer) rather than on ground layer (2 nd metal layer), which eliminates the signal degradation due to the EBG structure.
To prevent possible signal integrity as well as EMI problems, the plane stack-up in FIG. 31 is suggested. In FIG. 31 , the first plane is the solid reference ground plane for the signal lines on the top signal layer, the second plane is the AI-EBG plane, and the third plane is the solid reference ground plane for the signal lines on the bottom signal layer. In this stack-up, the AI-EBG plane is located between solid planes, which avoids possible problems associated with signal integrity because solid planes are used as reference planes for signal transmission lines. Since gaps in reference planes cause common mode currents of the transmission lines, the stack-up shown in FIG. 31 also avoids radiation from the AI-EBG structure. This has been confirmed through a combination of modeling and measurements in the next section.
Far Field Radiation Analysis: Three test vehicles were designed and fabricated for far field radiation analysis. The first test vehicle is a microstrip line on a solid plane, the second test vehicle is a microstrip line on an AI-EBG structure, and the third test vehicle is a microstrip line on an embedded AI-EBG structure. The third test vehicle was designed to suppress noise in mixed-signal systems without any EMI problems. This is possible since the solid plane was used as a reference plane for the microstrip line in this embedded AI-EBG structure. In FIG. 32 , the cross-section of these three test vehicles are shown. The top view of these three test vehicles is also shown in FIG. 33 . The dielectric material of the test vehicles is FR4 with a relative permittivity, ε r =4.4, the conductor is copper with conductivity, σ c =5.8×10 7 S/m, and dielectric loss tangent is tan (δ)=0.02. The copper thickness for the microstrip line, solid plane, and AI-EBG plane in the test vehicles is 35 μm, the dielectric thickness between two conductors is 5 mils, and the dielectric thickness of the most bottom layer is 28 mils. For the AI-EBG structures in the second and third test vehicles, the size of the metal patch is 1.5 cm×1.5 cm, and the size of metal branch is 0.1 cm×0.1 cm. It should be noted that the size of the metal patches in the first column near the SMA connector is 1.3 cm×1.5 cm.
The far field simulation was performed using SONNET™ for the three test vehicles. In this simulation, surface radiation from the surface of the test vehicles was investigated by changing the degrees (phi=0°˜180° at every 10° intervals and theta=−90°˜90° at every 10° intervals). FIG. 34 shows far field simulation results for the three test vehicles. It should be noted that test vehicle 2 showed the maximum radiation intensity (after 2 GHz) among the three test vehicles, since the AI-EBG plane was used as a reference plane. The periodic pattern in the AI-EBG plane makes higher radiation in the stopband.
To verify the simulation results, far field measurements were done for the test vehicles. The far field measurements were carried out using an Anritsu MG3642A RF signal generator (BW: 125 kHz˜2,080 MHz), an Agilent E4440A spectrum analyzer (BW: 3 kHz˜26.5 GHz, Res. BW=Video BW=3 MHz), and an antenna in an anechoic chamber. FIG. 35( a ) shows the measurement set-up for the far field measurements. Since the RF signal generator works properly up to 2 GHz, the far field measurement was also done up to 2 GHz. The distance between EUT and antenna was 3 m in this case. The RF signal generator was connected to EUT as a source, and the spectrum analyzer, which was connected to the antenna, recorded the field intensity from the surface of the test vehicles. In this measurement, radiation intensity from test vehicle 2 is the maximum among the three test vehicles, as shown in FIG. 35( b ), and test vehicles 1 and 3 showed almost the same radiation intensity because a solid plane was used as a reference plane. It should be noted that the radiated power intensities of the far field measurements in FIG. 35( b ) are in the range of the simulated radiated power intensities in FIG. 34 , except for the peaks at 190 MHz and 550 MHz for the test vehicle 2 . To minimize possible EMI problems, the test vehicle with the embedded AI-EBG structure (test vehicle 3 ) was designed and showed almost the same (or a little better) radiation characteristics than that of test vehicle 1 (reference test vehicle). This test vehicle (test vehicle 3 ) showed that an embedded AI-EBG structure could be used to suppress noise in mixed-signal systems without causing EMI problems.
Conclusion
In this Example, an efficient method for noise suppression and isolation in mixed-signal systems using a novel EBG structure, called an AI-EBG structure, has been described. The AI-EBG structure has been developed to suppress unwanted noise coupling in mixed-signal systems, and this AI-EBG structure showed excellent isolation (−80 dB to −140 dB) in the stopband. This results in noise coupling free environment in mixed-signal systems. Moreover, the AI-EBG structure has the advantage of being simple and can be designed and fabricated using standard printed circuit board (PCB) processes without the need for additional metal layer and blind vias. The excellent noise suppression in mixed-signal systems with the AI-EBG structure has been demonstrated through measurements, which make the AI-EBG structure a promising candidate for noise suppression and isolation in mixed-signal systems. Signal integrity analysis for the mixed-signal system with the AI-EBG structure has been described, and design methodology has been suggested for avoiding signal integrity and EMI problems. The AI-EBG structure can be made part of power distribution networks (PDN) in mixed-signal systems and is expected to have a significant impact in noise suppression and isolation in mixed-signal systems, especially at high frequencies.
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Alternating impedance electromagnetic bandgap (AI-EBG) structures, systems incorporating AI-EBG structures, and methods of making AI-EBG structures, are disclosed.
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CROSS-REFERENCE TO OTHER APPLICATIONS
This is a regular patent application submitted for a filing receipt under 35 U.S. Code Section 111(a). It claims priority from a provisional patent application submitted under 35 U.S. Code Section 111(b), accorded Ser. No. 60/081,869, filed Apr. 16, 1998.
FIELD OF THE INVENTION
The field of the invention are hollow structural metal or rigid members that are generally rectangular in cross sectional shape but with two opposing sides slightly wider than the other two opposing sides and with linear grooving formed near or upon the seams for the purpose of selective and controlled flaring of the tubing ends.
BACKGROUND OF THE INVENTION
Many modern greenhouses utilize elongated metal hollow tubing to construct various elements of the structure. Both square and rectangular cross-sectional shapes are utilized, as well as round and elliptical shapes. These are usually standard in cross sectional size, and typically measured by the outside dimensions of the cross-section.
Several wall thicknesses of steel are available in standard gauge dimensions (such as 12 gauge, 14 gauge, 16 gauge, etc.) to allow for a wide range of structural strength combinations. When hollow structural tubes are created from rigid materials that can be extruded, (such as aluminum or plastic), or from cold rolled, steel sheeting; the range of wall thicknesses is limitless.
Most of these structures are assembled on site, in an erector-set-like fashion. In many cases, erection is performed by employees of the owner of the building, who are non-experts the practice of building structures. They also usually have limitations on the tools available to them; although, standard wrenches, drills, saws, etc. needed to build an erector set are usually available and familiar. Because the height of walls and rough opening sizes for equipment needing to be installed usually vary from structure to structure, tubing members are usually shipped in long standard lengths. Measurements are then taken on site as the structure is built, and the standard tubes are cut down to the desired lengths.
A typical gable end of a greenhouse will usually be formed by a series of vertical hollow tubes being mated to horizontal hollow tubes to create openings for necessary fans, shutters and doorways. Most of these junctures of tubing members create 90° angled to interconnections, and usually employing 90° angle brackets. The typical angle bracket is usually first bolted, or otherwise fastened, to the side of a vertical post and then the horizontal member is fastened to the other side of the 90° angle bracket. If two angle brackets are used at a joint, this basically creates a two point mechanical junction at the joint (even if more than one fastener is used in each side of each 90° angle bracket).
The roof line of many greenhouses presents a Quonset-hut type or a bowed roof outline. When the vertical hollow tubing meets the outline of the roof bows, the junctions that are created form angles less than, or greater than, 90°. These angles change consistently along the roof bowing. The use of 90° angle brackets to form connections that are not 90°, are just not practical. In those cases, specially adapted end brackets are needed to join the vertical or horizontal members to the changing angles of the roof bow. These special brackets also rely on fasteners to clamp the special bracket to one or both sides of the bow, and then fasteners to connect the bracket to the vertical or horizontal structural member. This resulting connection of the prior art also usually results in a two point mechanical junction at the joint.
It is a principal object of the invention to provide a tubing member that can utilize an end portion of it's own length of material to readily construct an interconnection with another tubing member of the same cross-sectional size, using standard and readily available fasteners, but without the use of 90° angled or special brackets, and without the need for welding these members to each other.
It is another object of the invention to provide biasing grooves continuously along the longitudinal dimensions of the tubing, to selectively allow the end sides of the tubing to be split away and then flared outward, in a controlled manner, so as to create the fastening flanges that allow the two tubes to be reliably conjoined together at various angles of inclination.
A further object of the invention is to allow the internal dimension of two opposing longitudinal sides of the tube to be equal to, or slightly exceed, the external dimensions of the other two opposing longitudinal sides which will enable the two unflared ends of the tube to is span and overlap(?) the narrower dimension of the same sized tube.
A yet further object of the invention is to allow the person who is erecting the new structure to utilize one sized (squared or rectangular cross-sections) structural members to create both horizontal posts and vertical beams without needing various sized structural members, or various sized brackets, for accomplishing variously angled connections.
A still further object of the invention is to allow the installer to create end joints and tubing interconnections mechanically with simple fasteners that result in a three or four point mechanical interconnection on many junctures.
Another object of the invention is to create stable multi-rigid tubing interconnections that allow the external surfaces of the completed structure to be relatively free of protruding lugs and edge brackets, which protrusions would hinder fastening of sheet-like materials over the framed structure.
Still another object of the invention is to allow the tube to selectively allow the sides of the tubing to be split away and then flared outward, in a controlled manner, so to create the fastening flanges that allow the tube to be reliably conjoined with flat surfaces or the edges or corners of flat surfaces.
Still another object of the invention is to allow the tube to selectively allow the sides to of the tubing to be reliably conjoined with structural members that are rounded, elliptical, angular, larger, or smaller than the tube.
SUMMARY OF THE INVENTION
The present invention provides improved hollow structural tubing members that are adapted to allow integral interconnection flanges to be easily fabricated from the longitudinal ends of the tubing, by selectively flaring out one or more of the sides of the tube. The tubing, in a preferred embodiment, will be made having a basically square, or rectangular, cross-sectional configurations. The internal corners will not have much of an internal radius so that they form substantially 90° corners. In the preferred embodiment, one pair of opposing internal sides of a given tubing will have an inside dimension that is the same as, or slightly exceeds, the external dimension of the other two opposing sides.
Elongate, linear grooves are formed into the longitudinal planar walls of the tube, either internally or externally, or both. These grooves will be located proximal to or at the elongate seams of the tube, along the elongated comers of the tube. Such grooves are specifically provided to weaken the tubing walls at precise points (edges) near the corner seams. This feature will provide shear line(s) along these grooves. A special flaring tool, will be employed, which will have a slotted chamber in the tool working face, that allows it to readily extend over the somewhat variable wall thickness of the tubing. When this special tool is inserted inside the longitudinal end of the tube, and is projecting over one of the sidewalls of the tube, and while the tube is held firmly in place, as in a vice, a levering force is exerted on the handle end of the tool in an outward arcuate direction from the tube. The grasped side of the tube will split outwards, breaking away cleanly from the two adjoining sides of the tube, that are otherwise integral, at 90° angles to the one side being split away. The linear grooves will assure that the side splits away along the weakening grooves, resulting in the tube end bending outwards (or flaring) of the side that is being split away. The angular degree to which such split side is flared out will readily conform to the angle desired for the flange to provide an interconnection with another structural member or surface, either at a right angle or an inclined one.
BRIEF DESCRIPTION OF THE DRAWING (22 FIGS.)
FIG. 1 is a gable end view of a contemporary greenhouse having an arcuate-roofed structure, employing in tie structural framing, a variety of the tubular members of the present invention;
FIG. 2 is an enlarged, fragmentary end view of the end structure of FIG. 1, depicting same with some greater resolution;
FIG. 3 is perspective view depicting a prior art mode of conjoining two rectangular section, tubular members at a right angle, using dual 90° angle brackets;
FIGS. 4P, 4 S, and 4 E are perspective, side elevational, and longitudinal end views, respectively, of a first embodiment of the present invention, depicting an improved mode of conjoining certain tubular members of dissimilar cross dimensions;
FIG. 5 is a perspective view depicting another prior art mode of conjoining two rectangular members at a right angle at their longitudinal ends using one angle bracket of 90°;
FIGS. 6P, 6 S, and 6 E are perspective, side elevational, and longitudinal end views, respectively, of another improved mode of conjoining tubular members at the longitudinal ends of a pair of them;
FIG. 7 is a perspective view depicting a prior art mode of conjoining two members at a right angle, like that depicted in FIG. 3 using dual brackets, but now having been rotated spatially 90°;
FIGS. 8P, 8 S, and 8 E are a perspective, side elevational, and longitudinal end views, respectively, of another mode of conjoining at a right angle two rectangular, tubular members, which are each of substantially the same cross dimensions (squared);
FIG. 9 is an end elevational view of the next to final step for providing the single stepped-out finger-like end flaring (first stage) that overlaps the vertical member, with the results as seen in FIG. 8E;
FIGS. 10B and 10P are successive perspective views of one longitudinal end of a prior art rectangular tubular member, before and after cold working, which member lacks the groovings pretreatment feature of the present invention, but where an abortive effort was made to provide a discrete single flared finger, by mechanical leveraging;
FIGS. 11S, 11 E, and 11 T, are end, side, and top elevation views, respectively, of the conjoining of two tubular members, one of this invention, mated to a prior art round tube, at acute/obtuse angles;
FIGS. 12P and 12E are perspective and end views, respectively, of one angular member conjoined to one tubular member in a planar mode, at an interior acute angle, with flanges to be drawn from the one longitudinal member angled end, presenting one flared finger (and one sidewall) of the inclined member, serving as the dual areas of attachment to the horizontal tubular member;
FIGS. 13P, 13 S and 13 E are perspective, side elevation, and end elevational views, respectively, of one mode of conjoining one channel member (three sides as in FIG. 19 ), to one tubular member, being oriented acute angularly, now presenting three flared fingers, with the flanges all drawn from the one longitudinal channel member end, as projecting and providing three areas of attachment to the horizontal tubular member;
FIGS. 14R and 14S are longitudinal end views of a pair of tubular members, one of a rectangular cross section and the other of a squared cross section, each being provided with a plurality of longitudinal grooving lines coincident with (or proximal to) the elongate seams, on both of the inner and outer surfaces of the two members;
FIGS. 15R and 15S are longitudinal end views of another pair of members (rectangular and squared cross sections, respectively), each being provided with only a configuration of external grooving lines, located coincident with the elongate outer seams of each of such members;
FIGS. 16R and 16S are longitudinal end views of two tubular members (rectangular and squared cross sections, respectively), being provided with paired sets of longitudinal groovings, each pair bracketing the outer elongate seams of such members;
FIGS. 17R and 17S are longitudinal end views of two tubular members (of rectangular and squared cross sections, respectively) provided with elongate groovings, but only provided along the internal seams, with each linear grooving being located at each elongate corner of such member;
FIG. 18 depicts a tubular member of a rectangular cross section, now provided on one planar surface with two dissimilar, laterally projecting, hooked ledges, which ledges are adapted to receive an elongate wire spring element (not seen), which spring will serve to retain any overlapping sheeting (not seen) within the single sidewall external channel of the tubular member;
FIG. 19 is a three sided channel member of rectangular cross section, provided with both inner and outer longitudinal groovings located along its two elongate seams, having configurations like the groovings of FIGS. 14 R/S;
FIG. 20 is a two sided L-angle member provided with inner and outer longitudinal groovings, along its single elongate seam, like those of FIG. 19;
FIGS. 21S and 21T are side and top elevational views, respectively, of a elongate levered tool used for exerting a selective shearing force upon an open tubular end of a tubular member of the present invention and thus effecting the flared fingers, such as are depicted in FIGS. 4P, 6 P, 8 P, 11 S, and 12 P and 13 P; and
FIGS. 22A and 22B depict successive steps for the rotational shift of the tool of FIG. 21S after downward exertion, which produces a first outwardly projecting flange at one longitudinal end of a tubular member of the invention, and at any others, as needed.
FIGS. 23A, 23 B, 23 C, and 23 D are a longitudinal end views of a complemental set of rectangular cross-sectioned, tubular members, dimensioned to be snugly end-fitted one to another, when fabrication needs invite use of variably dimensioned tubings in a construction like that of FIG. 1;
FIGS. 24A and 24B are longitudinal end views of the similar tubular member having a rectangular cross-section and paired sets of external longitudinal groovings, with FIG. 24A denoting the internal longitudinal groovings located proximal to the external groovings and the location of external midwall, longitudinal groovings. FIG. 24B denotes sets of external pairs of groovings omitting the internal groovings;
FIG. 25 is a perspective schematic view of how a single stock tubular member can be variably end-modified (four variations) to provide both flared and lapped fingers for conjoining the member relative to an underlying linear edge of a mounting surface;
FIGS. 26P, 26 T, 26 S, and 26 E are perspective, top elevational, side elevational, and end elevational views, respectively, of a longitudinal ends conjoining of a pair of tubular members, each identically modified to include a longitudinal dimension, elongate recesses (or chambers), which recesses are also adapted to receive a depicted elongate spring clip, that will serve to retain a tucked-in sheeting (not seen);
FIG. 27E is a longitudinal end view of the horizontal member of FIG. 26P, now isolated from the conjoined vertical member of FIG. 26E, depicting an example of how tubing can be extruded in one piece with secondary uses built into the extrusion, in this case, for an elongate spring clip that is retained therein while it engages a flexible sheeting (not seen);
FIG. 28 is a side elevational view (partly in vertical section) of three tubular members, but now conjoined at right angles to provide a skeletal framework for an overlying wooden work bench.
FIGS. 29A to F depict the variety of end flange segments, producible from the longitudinal ends of a rectangular cross section tubing (See. FIG. 14R) for both right angle and acute angle conjoining to planar surfaces, like walls or ceilings;
FIGS. 30A to 30 G depicts the sequence of steps involved in converting a stock steel sheet to a rectangular cross section tubular member provided with a single longitudinal seam at each internal corner seam of the member (groovings provided on the inwardly folding surface); and,
FIGS. 31A to 31 F depicts the sequence of steps involved in converting a stock steel sheet to a rectangular cross section tubular member provided with a single longitudinal seam at each external corner seam of the member (the groovings initially provided on the outwardly folding surface).
DESCRIPTION OF PREFERRED EMBODIMENTS
In the gable end elevation view of a greenhouse structure (FIG. 1 ), a plurality of conjoined tubular members are depicted, involving both of arcuate and linear members, with right angle and acute/obtuse angle interconnections being provided. Gabled end 30 has: at least two right angle squared member unions, located intermediate of the longitudinal ends of horizontal members, such units as 32 L and 32 R; a right angle, squared member union located at the longitudinal ends of two tubular members, like 34 L/R; plural right angled, member unions, located intermediate of the ends of the vertical members, like 36 L/R; plural acute-angled, unions of two members, intermediate of the longitudinal ends of one inclined member, like lower 38 L/R, like middle level 40 L/R, and upper level 42 L/R members; Framed larger rectangular opening 44 would serve as a door position; higher rectangular opening 46 would serve as a fan-jet opening (intake shutter); left side, squared opening 48 L serves as a fist exhaust fan (not seen) opening, and opening 48 R serves as a second exhaust fan (not seen) opening. The elongate arcuate member 50 would present a uniform roof bow which will support the affixing of planar roof panels, or flexible sheeting (not seen), like the known Quonset style modules.
The broken-out side elevational view of FIG. 2 also depicts the plural, varied angle conjoining of tubular members of the present invention fabricated according to the present invention, in greater detail.
In the perspective of FIG. 3 is depicted a typical joinder means of two tubular members 52 and 54 , according to prior art practice. Two opposing L-brackets, 56 L/R, are the sole means of holding members 52 and 54 together, but providing strength only in the direction of the plane defined by such conjoined tubular members.
In FIGS. 4P, 4 S, and 4 E (perspective, side elevation and end elevation, respectively), are shown exemplary rectangular hollow tubular members, 58 and 60 in which the wider outside side dimension is 1.78:, the narrower outside side dimension is 1.5″, the wall thicknesses are ⅛″, and the inside dimension of the wider side is 1.53″, or slightly wider, than the outside narrower side dimension.
In the perspective view of FIG. 4P, a four way conjoining of two right angled, tubular members, 58 and 60 , is seen. The lower longitudinal end of vertical member 58 has been preworked to provide two opposing fingers, 62 L and 62 R, produced by a longitudinal end flaring-out tool means, to be disclosed later. These fingers provide bolting platforms for screw fasteners, like 64 L and 64 R. The remaining two sidewall fingers, 66 and 68 , are integral extensions of the upper member 58 lower end 70 . They serve to snugly straddle the underlying horizontal member 60 . These laterally aligned sidewalls ( 66 / 68 ) are also the platforms for two other fasteners, like 72 F and 72 B (in FIG. 4 E), which then provide a tube connection strength in all four directions. The linear groovings 73 L/R are seen in both of FIGS. 4P and 4S. Linear groovings, 75 U/L, are seen in both FIGS. also.
In the side elevational view of FIG. 4S, the narrower cross-dimension 74 (typically 1.5″ on this exemplary view) of upright member 58 is seen, as is the depending parallel sidewalls 66 , (and 68 ) which are spaced apart by appropriate cross-dimensioning of these members so to snugly straddle the narrower cross-dimension 76 (FIG. 4P) of underlying member 60 .
The end view of FIG. 4E depicts three of the four fingers/sidewalls ( 62 L, 66 , and 68 ), that interlock tubular members 58 and 60 .The wider cross-section 78 of member 58 is 1.78″, being such that the depending sidewalls, like 66 and 68 , slidingly engage the narrower surface 76 of horizontal tubular member 60 .
In the perspective view of FIG. 5, is depicted another prior art tubing end joinder of two rectangular tubular members, 80 and 82 , providing for only a single L-shaped, right angle bracket 84 , aligned inwardly. This provides but a single point interconnection with structural strength only, against outward divergence of the two members in their vertical plane.
In the perspective view of FIG. 6P, a three surface interconnection is provided by a modified upright member 86 of the present invention. Inwardly projecting finger 88 (formed from flaring one longitudinal wall of member 86 ), provides an inner L-bracket connection with member 90 (fastener 95 ), while parallel depending sidewalls, 92 F and 92 B, straddle upper surface 94 of underlying horizontal member 90 . The unflared sidewalls 92 F/B are traversed by fasteners 96 F and 96 B (FIG. 6 E). This configuration provides a three surface connection of members providing inherent strength against torsional forces in three directions.
The side elevation of FIG. 6S, shows the three point connection, profiling the split out, horizontal flanged finger 88 . The wider dimension ( 86 W FIG. 6P) of upright member 86 snugly straddles the narrower dimension (not seen) of horizontal member 90 . The end elevational view of FIG. 6E also depicts the three surface end mating of the members. The elongate linear groovings, like 96 L and 96 R, are depicted which facilitate the creation of end split off, like flanges 88 (FIG. 6 S), resting on the upper surface of member 90 .
In the perspective view of FIG. 7, is depicted a prior art, intermediate point conjoinder of a tubular vertical member 100 and a horizontal member 102 , along with their is two brackets, 104 U and 104 L, which provide bilateral strength in the plane of the two members only.
In FIGS. 8P, 8 E, 8 S and 9 are shown squared tubular members 106 and 114 attached at 90° angles to each other, to provide four directional strength. The preferred procedure to make this joint is to bend out 108 U and 108 L, then bend out 110 L, then fasten 108 U, 108 L, and the unflared side, then use tool to bend 110 L back to straddle.
In the perspective view of FIG. 8P, the longitudinal end of horizontal member 106 has been flared doubly to provide upwardly and depending fingers, 108 U and 108 L, and a stepped out, finger 110 L, drawn from sidewall 112 of member 106 . The opposing vertical sidewall (not seen) is unflared and not stepped-out, can still straddle the cross-dimension 114 N of upright member 114 . The unilateral stepped-out finger 110 L is achieved by bending same inwardly (from the intermediate position of FIG. 9) into parallel alignment of the sidewall 114 W of member 114 , after the other three fingers straddle upright member 114 . This provides a four surface tubular interconnection with structural strength in four directions. Note the elongate linear groovings ( 116 L/R and 119 L/R) on the external surfaces of both members. In the side elevational view of FIG. 8S, the expanded width of finger 110 L is depicted as embracing the dimension ( 114 N of FIG. 8P) of upright member 114 . In the end view of FIG. 8E, the four of the surface fasteners of this embodiment ( 118 U/L/F/B) are shown.
In FIG. 9 is depicted the pre-final fabricating step in the flaring of horizontal member 106 . The vertically flared fingers ( 108 U/ 108 L) and the unflared sidewall finger (not shown) are fastened to the vertical members 114 . Prior to anchoring, the right side sidewall finger 110 L is oriented outwardly (via tool levering) and is now positioned for manual bending about the upright member 114 to overlap same, so to give the four surface interconnection of FIG. 8 E.
In the view of FIGS. 10B and 10P, are depicted the alterations wrought upon one longitudinal end of a rectangular tubular member 120 , before and after cold working, where the prior art member lacks the longitudinal pre-grooving features (e.g., 116 L/R in FIG. 8P) of the present invention. By mechanical leveraging with the tool of FIG. 21, an effort was made to provide a discrete, outwardly flared finger 122 . The result was the poorly separated, sidewalls distorted, and ragged edged partitions 124 L/R of FIG. 10 P. Also, an internal protrusion 121 , bulging inwardly at external bulge 123 is caused by the mechanical leveraging tool of FIG. 21 . The member is unusable for planar interconnection.
In the side elevation view of FIG. 11S, a four surface interconnection has been provided for vertical member 124 (tubing of this invention), and inclined member 126 (a round tube not of this invention). Vertical member 124 has two opposing sidewalls (not seen) flared outwardly, i.e., finger 126 L at an acute angle, and finger 126 U at an obtuse angle, so to make dual contact on the surface of inclined member 126 . The vertical sidewalls ( 124 F and 124 B, FIG. 11E) of member 124 are cut transversely to conform their edges ( 128 F/B) to the changing angle of gable end bow (compare FIG. 2 ). This configuration provides for four fastener surfaces, and thus yields four directions of structural stability. The top view of FIG. 11T depicts the contacting surfaces and associated securing fasteners. In the end view of FIG. 11E, the unflared sidewall ( 128 F) is fastened to other gable end bow of member 126 . The opposing sidewall 128 B is flared outwardly to overlap the opposing linear surface of the bow member 126 .
The perspective view of FIG. 12P depicts an angular structural member 132 connected to a tubular structural member 136 . Member 132 (pre-flaring) is shown in the end view of FIG. 20, as two-sided channel 182 . A single, split out flanged finger 130 U and adjacent sidewall extension 130 F, of inclined member 132 , provide a two surface connection for fasteners 134 U/F. Here one side of inclined member 132 connects with the wider cross dimension 136 W of horizontal member 136 , while the second side 132 F of member 132 connects to the narrower cross dimension 136 N of horizontal member 136 . This is better depicted in the end view of FIG. 12 E.
In the perspective view of FIG. 13P, the lower member 142 has been rotated 90°. The inclined channel member 140 is fabricated with a single flared finger 140 U (obtuse angle), so that depending sidewall ends 140 F and 140 B straddle the narrow dimension 142 N of horizontal member 142 . The three surface connection of members (secured with fasteners 144 U, 144 F, and 144 B) is better seen in the end view of FIG. 13 E. The elongate linear groovings of member 140 , like 146 L, and 146 R, are quite proximal to the linear seams of tubing 142 and channel 140 , and are depicted in both FIGS. 13P and 13E. The side elevation view of FIG. 13S is also common to the embodiments of both FIG. 12 P and FIG. 13P, as the front side conjoinder shows a two surface connection, from this perspective.
In the related views of FIGS. 14R and 14S are seen both rectangular and squared cross-sectional tubular members, each with a plurality of longitudinal weakening groovings. In FIG. 14R, the inner comer seams 150 A, 150 B, 150 C, and 150 D, are each provided with a linear groovings, 152 A-D, for the length of the elongate member, providing an inner set of length. These incisions constitute useful weakening groovings that permit a clean separation and finger flaring out of each, or all, of the end walls, as may be required for a particular assembly. Companion squared member 145 is similarly scored, both internally ( 151 A-D) and externally ( 158 A-H) of its elongate seams.
In the paired embodiments of FIGS. 15R and 15S, the groovings configuration is altered. No inside seam groovings are incorporated, while only the external seams each have a single initially V-shaped grooving 160 A, 160 B, 160 C, and 160 D. These also will facilitate clean separation and flaring out of each, or all, of the longitudinal end sidewalls. Similarly so with squared cross-section of FIG. 15S ( 161 A-D).
In the paired embodiments of FIGS. 16R and 16S, only an external pair of groovings 162 A/B, 162 C/D, 162 E/F, and 162 G/H are included at each elongate seam. They are in a like configuration to that of the external groovings of FIG. 14R, and will still provide for selected weakening lines upon tube end flaring. The squared cross sectional member of FIG. 16S are similarly scored ( 164 A-D) on the external seams.
In the final cross sectional paired views of FIGS. 17R and 17S, only the internal elongate seams are provided with linear grooves, 164 A, 164 B, 164 C, and 164 D, for the elongate member length. These will provide the weakening lines for end flaring of any or all of the four sidewalls, 166 A-D. The squared member of FIG. 17S is similarly scored ( 167 A-D)on the internal seams.
In the cross sectional view of FIG. 18, the rectangular member of FIG. 14R has been modified in the process of extrusion ( 168 ) to present, on one surface, two laterally projecting ledges, dissimilarly configured. These elongate, seam-integral ledges ( 170 U and 170 L) present an externally located and recessed channel 172 , adapted to receive flexible sheeting (not seen), when the member 168 is positioned, in either the vertical or horizontal position, in the end wall of a greenhouse, like that of FIG. 2, and when vertical sheeting is to be draped and secured over the gabled end of the structure. A flexible wire spring device (not seen), such as I have disclosed in my earlier files, now U.S. Pat. No. 5,671,795 granted Sep. 30, 1997, can be used here to retain a draped over sheeting firmly within channel 172 of the horizontal-post-like member 168 of FIG. 18 . The flexible sheeting clasping ability, enabled by the protecting flanges 170 U and 170 L and channel 172 is not part of this invention, but is representative of how an ability to clasp flexible fabric to these structural members can be molded into the shape of the structural member when creating these shapes from extrudable materials. Similarly, with extruded members, the ability to mold other external sides of the tube can be utilized as an added benefit to the extruded shape while still allowing the flaring of ends of the tubes and the resulting conjoining of tubes, such as further described in FIGS. 26 .
In the FIG. 19 cross sectional view, a three sided channel member 174 is depicted, having a generally squared cross section, and being provided with a pair of offset groovings, 176 A/B and 176 C/D, located about the external elongate seams; and a single longitudinal grooving 178 A and C, located at both internal corners, 180 A and 180 C. The sectional view of FIG. 20 depicts a L-shaped, elongate member 182 having a set of both external and internal groovings, 184 A/B and 186 like the ones depicted in FIGS. 14S and 19. The use of members 174 and 182 in FIGS. 19 and 20 are shown in connections depicted in FIGS. 13P and 12P, respectively.
The schematic views of FIGS. 21T and 21S present one embodiment of an isolated flaring tool, useful with the structural member interconnections (as in FIG. 2) of this invention. The preferred embodiment of a flaring/bending tool 191 shown in FIGS. 21 S/ 21 T, side and top views, respectively, has a narrow tool-head 194 N and an opposing end wide tool-head 194 W welded to each end of the tool handle 192 . The tube bending slots 196 N and 196 W in the narrow tool-head 194 N and the wide tool-head 194 W, respectively, are slightly wider than the thickness of the tubing walls 200 N/W, and 201 N/W. The width of the narrow tool-head 194 N is slightly narrower than the narrower internal sidewall 200 N of the tubing 198 , and the width of the wider tool-head 194 W is slightly narrower than the wider internal sidewall 200 W of the tube 198 .
When the narrow tool-head 194 N is inserted between the wider sides of tube 198 and the slot 196 N is projected down over the end of the narrow tubing sidewall 200 N, as in FIG. 22A, the tool is in a position to begin bending out the end of the sidewall 200 N, of FIG. 21 T. As the tool handle 192 is pulled and rotated in the direction of the arrows shown in FIG. 22B, the narrow sidewall 200 N in FIG. 21T is bent or flared outwards and downwards to create the flare 200 in FIG. 22 B. The upper and lower flaring grooves 199 U/L in FIG. 21T would allow a controlled break-away of the end of sidewall 200 N from the opposing two sidewalls 200 W and 201 W. This step can be continued on one or more of the other end sidewalls of the structural members as the conjoining of the tubular, channel and angular, members of this invention may be required.
In the related end views of FIGS. 23A-D, are seen a complemental set of four rectangular cross-section tubular members, configured to have complementally sized cross-sections, such that they permit the snug lodging of the larger side dimension of one member within the shorter side-dimension of the next larger dimensioned tubular member; for example, the higher dimension 206 of tubular member 202 A will lodge snugly within the narrower vertical dimension 208 of tubular member 202 B.
Similarly, so with tube “B”, the wider dimension 210 of tubular member 202 B will lodge snugly within the shorter width between the inner sidewalls 212 of tube member 202 C, while the “C” tube 202 C has higher outer dimension 214 which will snugly fit into the inner vertical dimension 216 of “D” tube 202 D. These examples of complemental tubular cross-section dimensions provide for a variety of abutting ends pairing of rectangular tubings having close tolerances and adapted for pressure-fitted end engagements.
In the two longitudinal end views of FIG. 24 A/B, in addition to the depicted inner and outer corners sets of paired groovings, first shown in FIGS. 14 R/S, there are now provided, transversely and midway of each of the four planar external surfaces 220 N/S/E/W of tubing 220 , a longitudinal linear grooving located at 221 N/S/E/W for the purpose of assisting the installation of self-drilling fasteners 64 L as seen in FIG. 4P, to be started within the drill-guide grooves 221 N/S/E/W. In the machine extruded tubular embodiment of FIG. 24A, there are also provided elongated, paired outer grooves 222 A/D 223 A/B, 222 B/C, and 223 C/D, and elongate, rounded inner grooves, 224 A/B/C/D. Inner grooves 224 A/B work together with opposing outer grooves 223 A/B, to provide controlled sidewall separation lines to enable flaring outward of side 220 E. Inner grooves 224 B/C work together with opposing outer grooves 222 B/C to allow controlled flare-out of sidewall 220 S, etc.
In FIG. 24B, the outer grooves 222 A/D, 223 A/B, 222 B/C, and 223 C/D are deeper than the comparable outer grooves in FIG. 24A, and do not require the inner corner grooves, such as 224 A/B/C/D as in FIG. 24A, in order to effect controlled sidewall separation lines for flareout of the respective sides as illustrated in FIG. 25 .
The perspective views of FIG. 25 depict how longitudinal ends of tubular members, 228 , 230 , 232 and 234 , of the present invention can be adapted to be mounted upon the linear edge of a subsisting solid object 220 , like a concrete slab. On tubular member 228 , as the four fingers are produced using the tool of FIG. 21S, one finger (not shown) is eliminated by flexing the flared tab several times, until it breaks off at the bending line 228 E. One finger 228 F depends externally to be fastened to the slab sidewall 220 S, and two fingers 228 L/B are flared outwardly, to be fastened to the horizontal plane 220 F of slab 220 . On tubular member 230 , there are one depending finger 230 F, and three flared fingers, 230 L, 230 R, and 230 B.
Corner position tubular member 232 C has two depending end segments, 232 F and 232 R, and two flared fingers 232 L and 232 B, all being slab fastened. Inclined member 234 (like that of FIG. 12 P), is fastened to slab 220 S having one depending sidewall finger 234 R and three flared fingers, 234 L/F/B. This composite Figure depicts many of the useful end tube flarings that can be obtained by modifying the squared tubular ends of the tubular members of this invention.
In the views of FIGS. 26P, 26 T, 26 S, and 26 E, an end-conjoining of two identically configured tubular members, 240 and 242 (like that shown in FIGS. 6P, 6 E, and 6 S), are depicted with one major variation. Each of the conjoined members are provided with an integral elongate external recess, 240 R and 242 R, respectively. These elongate recesses are effected by modification of the extrusion die profile, well within the skill of the metal fabricating arts, to provide assembled tubular members, 240 / 242 , as appearing in end FIG. 26 E. While the U-shaped recesses, 240 R/ 242 R, are depicted as being integral with the shorter dimension 240 N of the horizontal tubing 240 of FIG. 27E, they can as readily be provided for the longer vertical dimension 240 W of tube 240 . The side elevation, end elevation, and perspective views of FIGS. 26 S/E/P show the end-conjoined pair of tubes, 240 / 242 , using two sidewall fingers 244 R and 244 L, and one horizontal flared finger 244 T. The end and top plan views of FIG. 26 E/T depicts how the three fasteners, 246 A/B/C, affix the tubes to one another with stability.
The retainer clips 248 / 250 in FIGS. 27 E/ 26 T snap resiliently into the channels 240 R/ 242 R of the modified tubular members. Clips 248 / 250 are a simple resilient V-shaped member of spring steel or plastic, which are shown engaged with flexible sheeting tucked into the channels, 240 R/ 242 R and anchored therein, when clips 248 / 250 are pressed between opposing inner lugs 252 U/L, which lugs are integral to the channel members themselves. This U-shaped clip and U-shaped channel is prior art and this configuration represents how features can be moulded into the sides of extruded tubes of this invention and still allow the tube sides at the ends to be flared out and utilized to construct various connections.
In the elevational view of FIG. 28, there is depicted how three tubular members, 264 / 266 / 268 , of this invention are conjoined at right angles to one another so as to provide a skeletal supporting framework, generally 260 , for an overlying planar bench surface 262 . Vertical member 264 admits internally of the end view cross section of final, horizontal tubular member 266 , having flared end 267 , and two unflared sides, 264 L/R. The other horizontal member 268 has a depending, right angle flared end segment 270 , a projecting, right angle flared finger 273 , aligned with the side of horizontal tube member 266 , and also a straightly aligned end segment 272 , overlapping horizontal member 266 . These modified end segments serve to conjoin the three members via the use of tubing sidewall fasteners 274 A,B,C and D, while the larger depending wood screw 276 , anchors the bench top 262 to the underlying tubular member framework 260 .
The composite views of FIGS. 29A-F show end modification of six tubular members, 290 , 292 , 294 , 296 , 298 , and 300 , which have been prepared to mount to any flat surface, such as a wall, floor or ceiling. The views of FIGS. 29 A/B show modification of two tubular members 290 , 292 , to present flared outward segments 290 A/B/C/D in FIG. 29A, and like flared outer segments 292 A/B/C in FIG. 29 B. The sole difference is the comparable reverse flared segment 290 D, depicted in FIG. 29A, but not appearing in FIG. 29B, because the equivalent fared member has been flexed with a flaring tool, as shown in FIG. 21T, until it has been broken off through metal fatigue at its bending line (not shown).
In FIG. 29C, the ends of the four sides of tube member 294 have been flared outward at 90° angles to create four flared fingers, 294 A/B/C/D. Likewise in FIG. 29D, tube member 296 has three 90° flared fingers, 296 A/C/D, but the comparable finger 294 B in FIG. 29C is missing in FIG. 29D, because the finger (not shown) has been broken away along line 296 B with a flaring tool like shown in FIG. 21 T. Similarly, in FIGS. 29 E/F are seen comparable linear edges, 298 B/C and 300 B/C of the tube members 298 / 300 , where fingers (not shown) have been flexed with the tool in FIG. 21T, and broken away after metal fatigue occurred.
The sequence of tube forming steps for working with stock sheet steel (an alternate metal to aluminum extrusions and suitable for these purposes) are depicted in FIGS. 30A to 30 G. The stock sheet 310 of FIG. 30A is conventionally converted to the longitudinally and parallelly multi-grooved planar member 312 in FIG. 30B, using a rotatable multiblade lathe 314 or hardened wheels in FIG. 30 C. The resulting multi-grooved member, 316 , is first folded, as seen in FIG. 30D, along the outermost pair of grooves, 317 A/B, and drawn to opposing right angles, 315 A/B, as are depicted in FIG. 30 E. Then, the inward convergence of the sidewalls, 318 A/B, is next forced along the inner set of longitudinal groovings, 319 A/B, as depicted in FIG. 30 F. Finally, in FIG. 30G, the three sidewalls, 318 A/B/C, are converged to form a rectangular cross section for a resulting tubular member 320 . Conventional welding along the longitudinal seam 322 provides a sheet steel tubular member having structural integrity for conjoining with other such tubular members, of like materials of construction. Internal longitudinal flaring weakening grooves, 317 A/B and 319 A/B, provide for controlled flaring at the ends of the tubes such as shown in FIGS. 29A-29F. Sheet gauges range from 44 (very thin) to zero (relatively thick). Sheets ranging from gauges 16 to 3 are best processed with the bending tools described herein.
Another alternate sequence of the tube forming steps for working with sheet steel that results in providing external longitudinal flaring weakening grooves, such as shown in FIGS. 15 R/S, is illustrated in FIGS. 31A-31F.
The stock sheet 330 of FIG. 31A is conventionally converted to the longitudinal and parallel multi-grooved planar member 332 in FIG. 31B using a rotatable multiblade lathe or hardened wheels 334 . The resulting multi-grooved member 332 is first folded, as seen in FIG. 31C, along the outermost pair of grooves, 337 A/B, and drawn to opposing right angles, 335 A/B, as are depicted in FIG. 31 D. Then the inward convergence of the sidewalls, 338 A/B, is next forced along the inner set of longitudinal groovings, 339 A/B, as depicted in FIG. 31, FIG. 31 E. Finally, in FIG. 31F, the three sidewalls 338 A/B/C, are converged to form a rectangular cross section for a resulting tubular member 340 . Conventional welding along the longitudinal seam 342 provides a sheet steel tubular member having structural integrity for conjoining with other such tubular members of like materials of construction, with external weakening grooves 337 A/B/C/D, located proximal to each corner for controlled flaring as illustrated in FIG. 25 and FIGS. 29A-F.
In Operation
Often, the side of the tube opposing the side that was just flared outwards will also need to be flared outwards. This will result in a dual-finger configuration for an interconnection between two lengths of tube of the same cross-section. Because the inside dimensions of the wider longitudinal sides of the tube are equal to, or slightly exceed, the external dimension of the same tube size, the two unflared sidewalls of the first tube will slidingly engage the narrower sidewall of another length of the same sized tube. The two flared-outwards sides of the first tube will be brought into planar contact with one of the narrower sides of the second tube.
After perforation, one or more fasteners can now be placed through each of the two (or more) flanges formed by flaring outwards the ends of the wider sides of the first tube and through the one narrower side of the second tube if using a self-threading fastener (or by bolting through both narrow sides of the second tube). Also, one or more fasteners can now be placed through the two narrower width sides of the first tube that were not flared outwards, through the wider sides of the sidewalls of the second tube which the first tube straddles.
When interconnections provide right angled junctures at two longitudinal ends of two tubes, one wider sidewall of the first tube can be flared outwards, while leaving the opposing second wider sidewall unflared. The narrower width sides of the first tube can be slipped over the one end of the second tube, straddling one of the narrower sides of the second tube, for a three point connection.
Preferably, by the use of self-drilling fasteners they can be used to create the interconnection in one simple step of drilling and fastening at one time. Installers, who do not have ready access to such fasteners, can drill holes through the flanges and utilize standard bolts and nuts for securing the conjoined tubular members.
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A rigid tubular member of variable length and rectangular cross-section adapted to be sized, flared and conjoined with at least one other rigid member to create a variety of tubular member frameworks for greenhouse construction, and the like. Each member is provided with a plurality of elongate, linear groovings, either located proximal to, or coincident with, the external and/or internal elongate seams of the member, with the inscribed sets of groovings are such being of a depth sufficient to facilitate separation under manual force of at least one, up to four, of the end sidewall segments, providing flared end segments, either disposed at right or acute angles, which segments are adapted to be fastened to another rigid member in any of several locations, along it, in the course of a framework erection.
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DESCRIPTION
This invention relates to a binding device with articulated components, particularly but not exclusively useful with such sport implements as ski boots, ice hockey boots, roller skates, and the like.
More specifically, the invention concerns a binding device of the type wherein a serrated strap is connected, with one end, to a tensioning assembly and is secured, with the other end, releasably to an adjusting assembly.
The tensioning assembly generally comprises a second class lever pivoted to a base of appropriate shape and size for attachment to a sport implement, such as the shell of a ski boot, and the adjusting assembly generally comprises a respective base defining a leader for the serrated strap and carrying a pawl or equivalent locking means adapted to engage with the strap serration teeth under the bias force of a suitable spring, said pawl being formed on a lever pivoted to said base and operable by the user of the sport implement.
A first, well recognized disadvantage of the binding devices of the type considered arises from the likelihood of the binding tension relaxing to a greater or lesser extent during the sport practice, owing to inadvertent striking of the pawl control lever causing disengagement of the pawl from the strap serration.
A second disadvantage is that ice formation between the pawl control lever and the ski boot shell may hinder operation of said lever, and accordingly, release of the binding at the end of a run.
An additional, not negligible disadvantage resides in the elaborate and expensive construction of such a device, especially as relates to making the various elements which comprise it and their assembly. In fact, in the making of the many pivotal connections for such components, it is necessary to perform appropriate drilling thereof, align the drilled hole axially to engage them simultaneously with a pivot pin, and to upset the pivot pin ends to confirm the resulting articulation. All these operations require the availability of suitable equipment, a comparatively long time, and labor.
It is the primary object of this invention to provide a binding device as indicated, which has such constructional and operating features as to overcome all of the disadvantages listed above in connection with prior art approaches.
This and other objects, to become apparent hereinafter, are achieved by a binding device with articulated components, particularly for use with sport implements such as ski boots, roller skates, and the like, of a type wherein a serrated strap is connected, at one end, to a tensioning assembly and is secured, at the other end, releasably to an adjusting assembly comprising a base effectively defining a leader for said serrated strap, which device is characterized in that it comprises a wall in said leader in juxtaposed relationship with said base and sloping toward said base and tensioning assembly, a wedge guided movingly across through said leader in substantial contact with said sloping wall, and a lever pivoted to said base and linked operatively to said wedge and being displaceable angularly against the bias of a spring means to drive said wedge through said leader.
Further features and advantages will be more clearly apparent from the following detailed description of a binding device according to the invention, given herein with reference to the accompanying illustrative and not limitative drawings, where:
FIGS. 1 and 2 show diagramatically in longitudinal section a binding device according to the invention, at two operative settings thereof; and
FIG. 3 is an exploded view showing in perspective the same device as in the preceding Figures.
With reference to the cited drawing figures, a binding device according to the invention comprises a serrated strap 1, connected at one end to a second class lever 2 pivoted on a base 3 which is adapted to be attached, by means known per se and not shown, to a sporting implement, e.g. the shell of a ski boot.
More specifically and in accordance with a feature of this invention, the strap 1 would be provided, at one end 1a thereof, with a pair of parallel lugs 4,5 extending lengthwise to said strap 1 and jutting therefrom. Said lugs 4,5 are through-penetrated by respective holes 6,7 adapted for engagement by pivot pins 8,9 of unitary construction and located at a selected intermediate position on said lever 2. Coupling of the pins 8 and 9 in the holes 6 and 7 is accomplished by force fitting and elastic spreading of the lugs 4,5.
The lever 2 (FIG. 3) has a forked resisting arm the prongs 2a,2b whereof are stiffened mutually by a cylindrical crosspiece 9a, formed integrally at the ends thereof. This cylindrical cross-piece forms the pivot for the lever 2 on the base 3. In particular, to accomplish this, the base 3 would be formed longitudinally with a raised portion 10 through--penetrated by a hole 11 forming a seat for receiving the aforesaid pivot pin 9a. The seat 11 has a cross-sectional configuration that does not complete a loop owing to the provision of a slit 12, formed in the raised portion 10 lengthwise to the hole 11. The coupling of the pin 9a with its corresponding seat 11 is of the snap-action type.
The device of this invention further comprises an adjusting assembly, comprehensively designated 13 in FIG. 1.
This adjusting assembly comprises, in turn, a base 14 which it designed and constructed for attachment, in a manner known per se, to the shell of a ski boot. This base 14 is constrained longitudinally by two lateral sides 14a,14b and defines a leader 15 for the serrated strap 1. In particular, (FIGS. 1 and 2) said leader has an inner wall 15a juxtaposed to the base 14 which is inclined toward the base and a strap inlet opening 16 (or entry of the leader 1), which has a slightly larger breadth than the overall thickness of the strap.
In the sections of the walls 14a,14b that extend within the leader 15, there are formed straight grooves 17,18, respectively, which extend parallel to the inner wall 15a of said leader. These grooves 17,18 form sliding guides for a wedge 19, which is provided for that purpose with a pair of side fins 19b,19c (FIG. 3).
Thus, the wedge 19 is guided movingly across the leader 15 and through it, and has a wall 19a in substantial contact with the sloping wall 15a of said leader.
The wedge 19 is provided with a tang 20 provided, in turn, with a pin 21 at its free end, whereby it takes a T-like shape. The pin 21, tang 20, and wedge 19 with its fins 19b and 19c are a unitary construction obtained, for example and preferably, by a molding process from a suitable plastic material.
Concurrently with this molding operation, the wedge 19 is provided with a serrated wall adapted to engage with the serration on the strap 1.
For operation of the wedge 19, the inventive device is provided with a second class lever 22 pivoted to the walls 14a,14b of the base 14. In particular, the lever 22 would be provided, to accomplish this, with two pins or trunnions 23,24 at one of its ends, which jut out at right angles and are adapted to snap-action engage with respective seats 25,26 formed in the aforesaid walls 14a,14b.
Again in accordance with the previously mentioned feature of this invention, the pins or trunnions 23,24, just like the seats 25,26 whereinto they snap, would be formed integrally with the lever 22 and the base 14, respectively.
This lever 22 is of a type formed laterally with a pair of opposed lateral sides 22a,22b, which are formed longitudinally and internally with respective grooves 27,28 (in the drawing only the groove 28 is shown). In these grooves, there are guided slidingly and rotatably the opposed ends of the pin 21 and wedge 19.
A spring 29 has one end engaged with the base 14 and the other end with the pivot pin 24 for the lever 22, to resist angular displacements around the respective pivot.
After tightening on the strap just described, it is the pull itself applied to the strap which locks it within the leader 15 by the very presence of the wedge 19 movable in said leader. The higher the pull applied to the strap in the release direction thereof the higher becomes the force locking it within the leader 15.
When the binding tension is to be relaxed, it will be sufficient to act on the lever 22 in the direction shown in FIG. 2. As a consequence of the lever 22 to wedge 19 coupling, the latter is released from the previously established engagement, thus freeing the serrated strap 1.
In addition to the technical advantage of providing a highly reliable binding which is easily adjusted, the inventive device affords the significant advantage that it is inexpensive to manufacture, especially as regards the assembling operations of its various parts. This advantage is attained also by virtue of the expedient adopted in forming the articulated couplings between the various component parts of the device: in fact, all the pins and their respective seats are formed integrally with their respective parts and their mutual fit is of the snap-action type.
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In a binding device comprising a serrated strap engaged through a leader of an assembly for adjusting the binding tension, the strap can be locked by tightening within the leader with the intermediary of a wedge mounted movably in the leader itself.
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FIELD OF THE INVENTION
The present invention relates to compositions and methods for accelerating decoke operation of transfer line exchangers (TLE) in steam crackers for olefin production. Particularly, the compositions and methods disclosed relate to introducing decoke enhancers by atomized injection into TLE inlet cone before and/or during furnace decoke operation. More particularly, the decoke enhancers are aqueous solutions of metal chromates and dichromates, or metal manganates and permanganates, or metal carbonates, or metal acetates and oxalates, or metal hydroxides, or their mixtures thereof. Additionally, the said compositions and methods are applicable to both shell-and-tube and double-pipe TLE's which are commonly used in steam crackers for olefin production.
BACKGROUND OF THE INVENTION
In a typical steam cracking furnace, a cracked hydrocarbon stream leaves furnace coils at a temperature ranging from 750 to 850° C. and enters immediately the TLE's, where the hot process stream is cooled rapidly from typically 750° C. to about 300° C. There are two types of TLE's which are very commonly used in industrial steam crackers for ethylene production: shell-and-tube TLE's and double-pipe TLE's. A shell-and-tube TLE has three main sections: the entrance cone, the tubesheet and tubes, and the exit cone, while a double-pipe TLE has mainly one section of a-pipe-in-a-pipe configuration.
Coke deposition in steam cracking furnaces is an inevitable process, reflecting the chemistry and nature of cracking reactions of hydrocarbons. Although coke deposition occurs in furnace coils, especially in the high temperature radiant section, it also happens in TLE's operated at lower temperatures. Particularly, coke deposition can become a very severe problem in a shell-and-tube TLE due to its geometric configuration. Additionally, with heavy feedstocks such as naphtha, the low operating temperatures (650-300° C.) in a TLE can induce substantial condensation of high boiling components from the cracked hydrocarbon stream. Then, the formed condensates in TLE can undergo a dehydrogenation process and form solid coke deposits.
Due to the inevitable coke build-up in the radiant coil and TLE's, steam cracking furnaces can normally operate for typically 20-60 days and a decoke operation has to take place to remove the coke deposits. A typical decoke operation involves passing air and steam through the furnace coils and TLE's which are maintained at more or less the same temperature range as during cracking operation. After 2-3 days, the coke deposits in the furnace coils can be removed (combusted or gasified) almost completely. However, for TLE's, such decoke operation often can not remove the coke deposits completely since the TLE operating temperatures are too low for combustion/gasification reactions to proceed to completion. Therefore, coke deposits accumulate fairly rapidly in TLE's and after a few cycles of coking-decoking operation (typically 3-4 months), the TLE's together with the whole furnace must be brought offline, cooled and the TLE's must be cleaned mechanically. This operation not only requires high maintenance costs but also cause interruptions to production for typically about 4-10 days. The present invention discloses a method to accelerate decoke operation for TLE's as well as the compositions of the decoke enhancers. Therefore, the overall TLE run length before a mechanical decoke can be prolonged and very likely mechanical decoke for the TLE can be eliminated. In addition, the injected decoke enhancer can also reduce coke formation in the TLE during the subsequent cracking operations and therefore extend the overall runlength of a steam cracker.
To date, different inhibitors to reduce coke formation in the furnace coils have been patented [U.S. Pat. No. 6,228,253 of Zalman Gandman, U.S. Pat. Nos. 4,889,146 and 4,680,421 of David Forester, U.S. Pat. Nos. 5,330,970 and 4,724,064 of Dwight Reid]. Reports on accelerators to gasification of coke in furnace coils can also be found in literatures [Dave Kesner et al, Chemical Technology Europe, Sep/Oct. 94, pp14-16, and S. E. Babash et al, PTQ Autumn 99, pp113-120]. However, there is hardly any prior art available on decoke enhancers for TLE's.
U.S. Pat. No. 6,228,253 issued May 8, 2001 to Zalman Gandman discloses an injection nozzle for injecting additives into the coils of a pyrolysis furnace. The body of the specification discloses injecting salts of group IA (group 1) and group IIA (group 2) in a polar solvent into the coils. The patent discloses the salts may be tetrasilicates, tetraborates, pentaborates, borates, nitrates, potassium liquid glass and boric acid. The patent fails to teach the use of chromate salts or carbonates as required in the present invention. Further the patent does not disclose or suggest injecting such mixtures into transfer line exchangers.
U.S. Pat. No. 4,889,146 issued Dec. 26,1989 to Betz Laboratories, Inc. discloses treating pyrolytic reactors and furnaces with alkali metals, preferably magnesium, acetates, chlorides and nitrates and magnesium sulfate. The reference fails to teach the use of group 1 or 2 chromates and dichromates nor does the reference relate to treating transfer line exchangers.
U.S. Pat. No. 5,330,970 issued Jul. 19, 1994 to Betz Laboratories teaches that a mixture of a boron compound and a dihydroxybenzene compound may be added to the steam or feedstock to a heated metal surface to reduce or inhibit coke formation. The boron compound may be ammonium borate, biborate, pentaborate, boron oxide or sodium borate. The dihydroxybenzene compound may be hydroquinone, resorcinol, catechol, or 4-tert-butyl resorcinol. The mixture may be added to the steam or the feedstock. The reference fails to teach the use of group 1 or 2 metal chromates and dichromates nor does the reference teach the application of these types of systems to transfer line exchangers.
There are a number of patents which teach the use of boron compounds to inhibit coke formation on heated metal surfaces, typically at about 1600° F. (about 870° C.) including boron, boron oxides or metal borides (U.S. Pat. No. 4,555,326) boron oxides, metal borides, and boric acid (U.S. Pat. No. 4,724,064) ammonium borate U.S. Pat. No. 4,680,421); and boric acid, boric oxide and borax (U.S. Pat. No. 3,661,820). These patents fail to teach the use of the chromate and dichromate compounds of the present invention and fail to teach the use of such compounds in decoking transfer line exchangers.
Chemical Abstract Vol. 83; 30687k (of French Patent 2,202,930) teaches adding molten oxides or salts of group III (now 13), IV (now 14) and VIII (now 8, 9, and 10). The abstract does not disclose the use of the metal chromates and dichromates of the present invention nor does the abstract disclose the treatment of transfer line exchangers.
U.S. Pat. No. 2,063,596, issued Dec. 8, 1936 to I. G. Farbenindustrie Aktiengesellschaft discloses exposing compounds such as molybdenum carbonyl, tetra ethyl lead and chromyl chloride to temperatures above which they decompose to help reduce coke formation on metal surfaces. The patent does not teach the chemicals required in the present invention.
U.S. Pat. No. 5,648,178 issued Jul. 15, 1997 to Chevron Chemical Company teaches treating or coating (painting) the internal surface of a reactor system with a group VI B (now group 6) metal layer. A particularly useful metal is chromium and the chloride forms appear to be particularly useful in the paint. The patent fails to teach the group 1 or 2 metal chromates and dichromates of the present invention.
There are several papers by VNIIOS in 1994 and 1999 relating to inhibitors for coke build up in a furnace using group 1 and 2 metal acetates, carbonates, nitrates and sulphates and compounds of sulphur, phosphorous, boron, aluminum, silicon, tin antimony, lead, cadmium, siloxane, derivatives of monocarboxylic and alkylsulphonic acids. The inhibitor is continuously injected into the hydrocarbon process stream prior to the cracking section. VNIIOS also has a paper (Chem. Tech. Eur. September 1994, pp14-16) which discloses an accelerated decoking method for hydrocarbon furnace coils. The methods were developed for vinyl chloride (VCM) plants, but it was claimed to be applicable to furnace tubes of other plants where coke buildup is a problem. This process differs from conventional chemical cleaning methods because it uses an endothermic reaction and is carried out in the absence of air. Therefore, coke removal is achieved through catalytic gasification reactions, instead of combustion.
A Russian patent R.U. 2168533, issued Oct. 6, 2001 to V. A. Bushuev, reveals a periodical non-stop decoking process for tubular pyrolysis furnace coils. The process consists of two periods without switching the furnace train to decoke mode. In the first period—hydrocarbon cracking, the first additive is introduced into hydrocarbon feed which optionally may contain sulfur. Typical additive components are phosphorous-containing or sulfur-containing compounds, such as KH 2 PO 4 , H 3 PO 4 , or DMS. During the second period—coil decoking, another additive containing either alkali or alkali-earth metal compounds, such as MgCl 2 , MgSO 4 , Mg(OCOCH 3 ) 2 is introduced into hydrocarbon feed to promote online coke gasification from the coil surfaces. Again, this invention fails to reveal the use of group 1 or 2 metal chromates or dichromates to enhance decoke operation in TLE.
SUMMARY OF THE INVENTION
The present invention provides a process of treating transfer line exchangers in an ethylene cracker comprising injecting up to 15 wt % based on the stream entering the transfer line exchanger of a solution consisting of a polar solvent and up to 80 weight % of a solute composition comprising
(i) from 10 wppm to 100 wt % of one or more group 1 or 2 metal chromates and dichromates;
(ii) from 0 wppm to 40 wt % of one or more group 1, 2 and 7 metal carbonates;
(iii) from 0 to 30 wt % of one or more group 1 or 2 manganates or permanganates;
(iv) from 0 to 20 wt % of one or more group 1 and 2 metal acetates and oxalates;
(v) from 0 to 1 wt % of one or more group 6 or 7 acetates or oxalates; and
(vi) from 0 to 1 wt % of one or more group 1 and 2 metal hydroxides, into a carrier stream comprising an inert gas, or air, or process steam or mixtures thereof injected at one or more points between the outlet of the radiant coils and the inlet of said transfer line exchanger at a temperature from 300° C. to 750° C. during a decoking operation of said ethylene cracker for a period of time not less than 1 second.
DETAILED DESCRIPTION
FIG. 1 is a schematic drawing of the device to conduct the lab scale experiments.
In steam cracking of hydrocarbon feedstocks typically the product stream leaves the furnace and enters the transfer line exchangers (“TLE's”) which are normally made of lower grade metals such as carbon steel. During normal operation there is a build up of coke in the transfer line exchanger. There are technologies that permit furnace tubes to be operated for longer periods of time before decoking (e.g. U.S. Pat. No. 5,630,887). However, the transfer line exchanger is not decoked until the furnace tube is decoked. Accordingly there is a need for methods to decoke the transfer line exchanger faster and cleaner and to reduce the coke build up in a transfer line exchanger.
During steam cracking operation (e.g. normal operation) the transfer line exchanger may be operated at a temperature from about 300° C. to about 650° C. During decoking, the transfer line exchanger may be held at temperatures from 300° C. to 750° C., preferably from 450° C. to 750° C.
At such a temperature range, the desired combustion and gasification reactions to remove coke deposits do not normally proceed at a fast rate. Therefore, introduction of disposable catalysts (decoke enhancers) to accelerate these reactions at such low temperatures becomes necessary.
The decoking compositions of the present invention may comprise up to six groups of components. One of the groups of components is essential (e.g. component (I)) and there are up to five optional groups of components (e.g. components (ii), (iii), (iv), (v) and (vi) although it is preferred that component (ii) be present).
The essential component is one or more group 1 or 2 (formerly group IA or IIA) metal chromates and dichromates. Preferably these salts are selected from the group consisting of Li 2 CrO 4 , K 2 CrO 4 , Na 2 CrO 4 , BaCrO 4 , Ba 3 (CrO 4 ) 2, , MgCrO 4 , CaCrO 4 , Cs 2 CrO 4 , Li 2 Cr 2 O 7 , K 2 Cr 2 O 7 , Na 2 Cr 2 O 7 , and Cs 2 Cr 2 O 7 . The chromates and dichromates may be used in an amount from 10 parts per million by weight (wppm) to 80 wt %, preferably from 50 wppm to 30 wt %, most preferably from 100 wppm to 15 wt % of the solute composition.
The compositions of the present invention may comprise up to five optional groups of components selected from the group consisting of
(ii) from 0 wppm to 40 wt % of one or more group 1, 2 and 7 metal carbonates;
(iii) from 0 to 30 wt % of one or more group 1 or 2 manganates or permanganates;
(iv) from 0 to 20 wt % of one or more group 1 and 2 metal acetates and oxalates;
(v) from 0 to 1 wt % of one or more group 6 or 7 acetates or oxalates; and
(vi) from 0 to 1 wt % of one or more group 1 and 2 metal hydroxides.
The one or more group 1, 2 and 7 metal carbonates may be selected from the group consisting of K 2 CO 3 , Na 2 CO 3 , MgCO 3 , CaCO 3 , and MnCO 3 . The carbonates may be used in the solute in an amount from 5 wppm to 40 wt %, preferably from 50 wppm to 10 wt %, most preferably from 100 wppm to 5 wt %.
The one or more group 1 or 2 manganates or permanganates may be selected from the group consisting of potassium manganate (K 2 MnO 4 ), potassium permanganate (KMnO 4 ), sodium manganate (NaMnO 4 ), and magnesium permanganate (hexahydrate) (Mg(MnO 4 ) 2 ·6H 2 O). The group 1, 2 or 7 manganates or permanganates may be used in the solute in an amount from 0 to 30 wt %, preferably from 1 wppm to 15 wt %, most preferably from 10 wppm to 5 wt %.
The one or more group 1 and 2 metal acetates and oxalates may be selected from the group consisting of potassium acetate (KC 2 H 3 O 2 ), calcium acetate (Ca(C 2 H 3 O 2 ) 2 ), potassium oxylate (K 2 C 2 O 4 ), and calcium oxylate CaC 2 O 4 . The group 1 and 2 metal acetates and oxylates may be used in the solute in amounts from 0 to 20 wt %, preferably from 20 wppm to 10 wt %, most preferably from 100 wppm to 1 wt %.
The one or more group 6 or 7 acetates or oxalates may be selected from the group consisting of manganese (II) acetate tetrahydrate (Mn(C 2 H 3 O 2 ) 2 ·4H 2 O), manganese (II) oxalate dihydrate (MnC 2 O 4 ·2H 2 O), chromium (II) acetate monohydrate (Cr(C 2 H 3 O 2 ) 2 ·H 2 O), and chromium oxalate monohydrate (CrC 2 O 4 ·H 2 O). The group 6 or 7 acetates or oxalates may be used in the solute in amounts from 0 to 10,000 wppm, preferably from 1 to 1,000 wppm, most preferably from 5 to 500 wppm.
The one or more group 1 and 2 metal hydroxides may be selected from the group consisting of NaOH and KOH although other hydroxides are available. The hydroxides may be used in the solute in amounts from 0 to 1 wt %, preferably less than 1000 wppm, most preferably less than 100 wppm.
The above components are dissolved in a polar solvent, preferably water to provide a solution comprising up to 80 wt % of solute, preferably less than 30 wt %, most preferably less than 15 wt % of solute. Typically the solute is present in the solution in an amount not less than 100 wppm.
The resulting solution is used during the decoking operation of an ethylene furnace to accelerate (catalyze) the rate of decoking of a transfer line exchanger. As an additional benefit the treatment retards the formation of coke in a transfer line exchanger treated in accordance with the present invention. The solution may be introduced at one or more points between the outlet of the radiant coils and the inlet of the transfer line exchanger in several manners. The solution could be atomized into a carrier gas and injected just upstream of the inlet of the transfer line exchanger. If the solution is atomized in a stream injected upstream of the inlet to the transfer line exchanger the carrier gas may be air, steam or an inert gas such as nitrogen or a mixture thereof. Preferably the carrier gas is nitrogen. The solution is injected to provide up to 15 wt %, preferably from 5 wppm to 15 wt %, most preferably from 10 to 12000 wppm, desirably from 50 to 1000 wppm based on the decoking stream entering the transfer line exchanger.
The process may be a continuous process conducted over the duration of the decoking process. The process may be pulsed. One or more pulses of solution is injected into the transfer line exchanger during the first part of the decoking operation before an oxidizing atmosphere such as air is introduced into the transfer line exchanger. Typically one, but possibly more than one pulse is introduced into the transfer line exchanger shortly before the decoking operation terminates.
In the pulsed mode of operation the time for introducing the solution into the transfer line exchanger (e.g. one or more pulses) may range up to about 120 minutes or more. Generally, under typical conditions the time of treatment should not be less than 1 second. The time may be split so that from 25 to 100%, preferably from 30 to 70% of the time for introducing the solution into the transfer line exchanger is prior to the introduction of the oxidizing atmosphere (e.g. air) during the decoking operation and the balance 75 to 0%, preferably from 70 to 30% of the time occurs (shortly) before termination of the decoking operation. The duration of the injection may be as short as 1 second for high injection rates of high concentration solutions (e.g. 15 wt % injection rate of an 80 wt % solution) or at lower injection rates and concentrations (e.g. injection rate of less than 12000 wppm of a 15 wt % and lower solution) typically not less than about 10 seconds.
The present invention will now be illustrated by the following non-limiting examples.
EXAMPLES
The reactor used for testing of the decoke enhancers is shown in FIG. 1 . Typically, hydrocarbon feeds are introduced into the reactor through a flow control system 1 . A metering pump 2 delivers the required water for steam generation in a preheater 3 typically operating at about 300° C. The vaporized hydrocarbon stream then enters a tubular quartz reactor tube 4 typically heated at about 900° C., where steam cracking of the hydrocarbon stream takes place to make pyrolysis products. The product stream then enters a quartz tube 5 which simulates the operation of a transfer line exchanger. This transfer line exchanger was designed and calibrated in such a way that metal coupons 6 can be placed at locations where temperatures are known. Typically, metal coupons are located at the positions where the temperature is 650° C., 550° C., 450° C. and 350° C. Coupons are weighed before and after an experiment to determine changes in weight. The coupon surfaces can be examined to determine morphology and composition. After the transfer line exchanger 5 , the process stream 7 enters a product knockout vessel (not shown) where gas and liquid samples can be collected for further analyses. In the reactor unit, another metering pump 8 is used to deliver decoke enhancer solution of the present invention at precise flow rates and a gas control system 9 to disperse the enhancer solution at the inlet of the transfer line exchanger 5 .
For decoke experiments, air enters at a controlled flow rate of 2 standard liters per minute (slpm), replacing hydrocarbon feeds, through the feed delivery system 1 . Water is also admitted, through the metering pump 2 , into the preheater where steam is generated. The tubular furnace 4 operates at again typically 900° C. and transfer line exchanger 5 maintains a temperature profile from 700° C. to 300° C. Coke samples are placed at the temperature locations of 650° C., 550° C. and 450° C. In the decoke experiment, the coke samples used can be either ground coke particles, coke chips directly from an ethylene plant transfer line exchanger or coke deposits formed in situ on the surfaces of the metal coupons during a previous cracking experiment.
In the experiments the following agents were used
NDE1 was an aqueous solution containing: 200 wppm of Ba 3 (CrO 4 ) 2 , 800 wppm of K 2 CrO 4 , 3000 wppm of K 2 Cr 2 O 7 , 200 wppm of MgCO 3 , 5 wppm of CaCO 3 , 5 wppm of CaC 2 O 4 .H 2 O and 25 wppm of KOH
NDE2 was an aqueous solution containing: 300 wppm of Cs 2 CrO 4 , 500 wppm of K 2 CrO 4 , 3000 wppm of K 2 Cr 2 O 7 , 500 wppm of MgCO 3 , 5 wppm of Ca(C 2 H 3 O 2 ) 2 , 400 wppm of Mg(MnO 4 ) 2 , 500 wppm of KMnO 4
NDE3 was an aqueous solution containing: 2000 wppm of K 2 Cr 2 O 7 , 500 wppm of MgCO 3 , 300 wppm of Ca(C 2 H 3 O 2 ) 2 , 500 wppm of KMnO 4
Example 1
Decoke Test in a Thermobalance
Plant TLE coke deposits were crushed into small coke particles (2-5 mm). The coke particles were then impregnated with a decoke enhancer (NDE1, NDE2 or NDE3) at various concentrations up to 3190 wppm of the coke sample weight. Decoke tests were carried out in a commercial thermal balance operating at 600° C. A typical sample size of 10 mg was used for the tests and an air flow of 50 standard cubic centimeters per second (sccm), saturated with 60° C. water vapor, was used to decoke the sample. Baseline runs, without the enhancer loading, were also carried out under the identical conditions. The results are shown in Table 1.
TABLE 1
Enhancer loading
Time for 50 wt % Decoke
Coke sample
(wppm of sample)
(min)
TLE coke
0
100.6
TLE coke + NDE1
50
80.4
TLE coke + NDE1
100
64.2
TLE coke + NDE1
300
45.1
TLE coke + NDE1
500
34.7
TLE coke + NDE1
1662
21.1
TLE coke + NDE2
100
83.03
TLE coke + NDE2
1663
20.41
TLE coke + NDE3
3190
12.0
The results clearly show that any one of these three tested enhancers can accelerate the decoking process. For NDE1 and NDE2, the time for 50% decoke can be as short as ⅕ of the time for the baseline run test. With NDE3 at a higher impregnation concentration, the time for 50% decoke is just ⅛ of the time for the baseline run. Based on these results, the enhancers loaded at concentrations even higher than indicated in the table are likely to further accelerate the decoking process.
Example 2
Decoke Tests with Preloaded Enhancer Using the TLE Testing Unit
The same coke sample, as used in Example 1, was used for further tests using the TLE testing unit (FIG. 1 ). Three quartz boats, containing coke samples of typically 1.0 gram each, were located at the pre-calibrated temperature points, 650° C., 550° C. and 450° C., in the TLE tube 5 . The coke samples were impregnated with the decoke enhancer NDE2 at a concentration from 100 to 1600 wppm of the coke sample weight. Prior to the decoke test, the furnace of TLE testing unit was heated to 900° C. with a flow of N 2 at 6 slpm and steam at 10 cc/min entering the TLE. Once the TLE temperatures reached the required profile, N 2 was reduced from 6 slpm to 2 slpm and air introduced at 2 slpm to start the decoke test. The water remained at the same feeding rate.
After 3 hours of decoke, furnace heating was stopped and air and water feeds were shutdown. N 2 flow was increased from 2 slpm to 6 slpm to cool the TLE tube to room temperature. The coke sample residues were then taken out and weighed to determine the weight loss. The results are shown in Table 2.
TABLE 2
Enhancer loading
conc. (wppm
Coke weight loss, wt %
of coke sample)
At 450° C.
At 550° C.
At 650° C.
Total
0 (baseline)
1.2
6.1
37.5
14.9
100
1.0
4.9
37.8
14.2
300
2.0
8.1
44.0
18.0
700
2.3
11.5
51.4
21.7
1100
3.4
12.4
58.6
26.6
1600
5.7
15.7
68.6
31.0
It is clear that NDE2 enhancer accelerates the decoke process at tested TLE temperatures. At 650° C., the coke weight loss increased with increasing NDE2 loading concentration. Up to 1600 wppm loading, the coke weight loss is 83% higher than the baseline. At the other two TLE temperature locations, the increases in weight loss are lower. However, the relative increases (in terms of percentage changes) are higher: 370% and 160% higher than their baseline numbers, respectively. This indicates that decoke enhancement at lower temperatures is more significant in relative teams, and this is consistent with basic principles of catalysis.
Example 3
Decoke Tests with Enhancer Injection
Plant TLE coke deposits were cut into flat coupons whose external surface areas can be measured. These coke coupons were then placed at the 650° C., 550° C. and 450° C. locations in the TLE tube 5 . The same procedure, as in Example 2, was used to heat up the TLE tube to the desired temperature profile. The decoke enhancer NDE2 (1000 wppm aqueous solution) was, then, delivered through a metering pump 8 at 2 cc/min into the injection port. At the same time, N 2 was admitted through the gas delivery system 9 at 5 slpm into the injection port to disperse the NDE2 solution into the TLE tube 5 . After 10 minutes of injection, both NDE2 solution and the N 2 were shut down. However, the N 2 and steam flows through 1, 2, 3 and 4 were maintained for about 30 minutes to allow the TLE temperature profile to re-establish. Afterwards, a decoke test was started following the same procedure as in Example 2. A baseline run, without enhancer injection, was also carried out for comparison. The results given in Table 3 are normalized for the gross or apparent surface areas of the coke chip coupons tested.
TABLE 3
NDE2 injection
Surface normalized decoke rate
(wppm of warm-up
(mg/cm2/hr)
stream)
450° C.
550° C.
650° C.
Baseline
0
0.6
2.7
22.7
Run-1
114
1.3
6.6
49.3
Run-2
114
1.5
7.3
52.9
Run-1 and run-2, carried out under identical cracking conditions, were duplicate runs for the confirmation of experimental repeatability. The results show that decoking rates increase by at least 100% for all three TLE temperatures at tested injection rate of NDE2 enhancer. It is, however, believed that further improvement in decoking rate can be reached with further increase of NDE2 injection concentration, either by increasing NDE2 enhancer concentration or by extending injection duration.
Example 4
Composition Changes of Carbon Steel Surfaces
Two sets of carbon steel coupons (2½ wt %Cr, 1 wt % Mo), a typical metal for ethylene plant TLE's, were used in coking-decoking experiments for comparison. The coking test was carried out in the TLE testing unit for 16 hours. Ethane was used as feedstock entering the reactor at 4.3 slpm and steam dilution ratio was at 0.3 w/w, with a residence time of about 1 second. After the coking period, N 2 and steam were admitted into the TLE test unit to establish the temperature profile for the decoking period. The experimental parameters for the decoking period were previously given in Example-3. With one set of coupons, this full coking-decoking cycle was done as a baseline case, whilst with the other set of coupons the decoke enhancer NDE2 was injected prior to decoking at about 60 wppm of the process stream for 10 mins. An additional injection of the same dose took place in the middle of the decoking period (at 1.5 hr for 10 mins). After the completion of the whole coking-decoking experiment, both sets of coupons were taken out for determination of their surface compositions. The results are given in Table 4. Additionally, the composition of a fresh metal coupon is also listed for comparison.
TABLE 4
Surface composition (wt %)
Coupon
C
O
Mg
Si
K
Cr
Mn
Fe
Base Metal
0.82
0.15
2.35
0.56
95.23
0.
Baseline Run (TLE 450° C.)
0.94
1.89
0.79
0.70
95.61
Baseline Run (TLE 550° C.)
0.79
1.96
0.19
0.43
0.77
95.77
Baseline Run (TLE 650° C.)
0.83
1.78
0.15
0.26
0.91
95.96
NDE2 Injected (TLE 450° C.)
2.94
1.52
0.74
0.70
94.01
NDE2 Injected (TLE 550° C.)
0.81
2.03
0.21
0.14
0.91
0.84
95.06
NDE2 Injected (TLE 650° C.)
1.34
1.38
0.37
0.30
20.10
12.88
0.64
59.63
3.
Comparing the surface compositions of metal coupons between the baseline run and the base metal, oxygen content became obviously higher after the coking-decoking cycle. The main metal element Fe and some of the minor elements, such as Si and C remain relatively unchanged. However, Cr concentration is seen to drop substantially from the base metal to the coupons for the baseline run. Further, the decrease in Cr concentration continues as coupon temperature rises from 450 to 650° C. Mn is seen to increase marginally, and Mo became not measurable.
From the NDE2 injection experiment, there are four major changes:
1. The surface concentrations of elements, such as Cr, Mo, Mn and Si, increased
2. Elements, which promote coke gasification/decoke, such as K and Mg, are seen to increase. In some cases, e.g., on the coupon placed at 650° C., such increases are substantial.
3. The main element (Fe) is seen to decrease substantially due to the deposition of Cr and K on the coupon surfaces.
4. Oxygen concentrations increased to the similar level as for the coupons from the baseline run.
Example 5
Comparative Coking Tests of Coated Coupons
The two sets of metal coupons, as used for the experiments in Example 4, were tested again for coke make in the TLE. The purpose of these further coking tests was to determine the effect of the residual NDE2 decoke enhancer on the coke formation when these metal surfaces are exposed to hydrocarbon cracking stream again. For further comparison, results of a set of fresh coupons are also given in Table 5.
TABLE 5
coke make in TLE (mg/cm2)
350° C.
450° C.
550° C.
650° C.
Fresh coupons
0.1
3.2
5.4
43.8
Coupons used for baseline run
n/d
2.9
32.0
123.8
Coupons used for injection run
n/d
0.0
6.1
3.1
Clearly, the metal coupons used for the baseline run in Example 4 produced much more coke deposits than the fresh coupons. In contrast, the set of coupons used for the injection run produced significantly less coke deposits. For the 650° C. coupon, for Example, the coke make is only 2.5% of the coke deposited on the coupon used for the baseline run in Example 4, and is about 7% of the coke formed on a fresh coupon and about 2.5% of the coke make for the conventionally decoked coupon.
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In a steam cracking operation the formation of coke is a problem which needs to be overcome. While significant work has been done on decoking of furnaces little work has been done regarding transfer line exchangers. Coking of transfer line exchangers (TLE) may be reduced by injection of a solution containing at least one group 1 or 2 metal dichromate or dichromate and one or more of a group 1, 2 or 7 metal carbonate into the TLE.
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BACKGROUND OF THE INVENTION
This invention relates generally to signaling devices of the type which indicate when the door of a mailbox has been opened and mail is present in the box. It is desirable that a remotely visible flag or other such signaling means be automatically displayed in response to opening of the door so that the mail carrier has no responsibility for actuating the signaling device. It is also desirable that the device be easily reset or cocked after the addressee removes the delivered items from the box without employing both hands in the resetting operation.
One prior art signaling device which incorporates the desirable features noted above is disclosed in U.S. Pat. No. 3,084,853 issued to P. E. Kopp on Apr. 9, 1963. Kopp shows an elongated signal arm pivotably mounted on a mailbox and swingable from a cocked horizontal position to a tripped vertical position. The non-signaling end of Kopp's arm carries a pawl which interfers with a strike bracket mounted on the box door whereby the arm is maintained in a horizontal position until the door is swung open. Upon opening the door, the arm is pivoted downwardly by gravitational force operating on a pair of weights attached to the non-signaling end of the arm. The first weight causes the arm to pivot to an upright or vertical signaling position while the second weight, due to a different moment arm, urges the arm against a stop to maintain its vertical orientation. To reset the Kopp device the signal arm is swung manually back to a horizontal position whereby the pawl, which is pivotably linked to the first weight, strikes the strike bracket and pivots about the non-signaling end of the arm to override the strike bracket there by assuming the cocked position.
While the Kopp device does provide automatic, gravity actuated signaling and resetting can be accomplished with only one hand, this device is overly complicated from a structural standpoint and is, therefore, unnecessarily costly to manufacture. Thus Kopp requires a pair of weights and means for individually mounting the same on his signal arm. Also complicating Kopp's device is the reset pawl which is pivotalby attached to the signal arm and is also pinned to a strap which carries one of the weights.
SUMMARY OF THE INVENTION
A general object of the invention is to provide a mailbox signaling device which overcomes the aforedescribed shortcomings of prior art signaling devices intended for the same purpose. More specifically, this invention provides improvements in the type of signaling device disclosed by Kopp in U.S. Pat. No. 3,084,853.
The principal object of this invention is to provide a gravity actuated signaling device which is resettable by the use of only one hand and which comprises a minimum of operating parts. To this end the invention comprehends a signal arm pivotably attached to a mail box and a single weight pivotably attached to the non-signaling end of the arm. The weight configured according to this invention is advantageously adapted to serve the combined functions of Kopp's pair of weights and also replaces the separate pawl and complicated linkage required by Kopp to interact with his strike bracket.
Another object is to provide a signal arm which carries at its non-signaling end a single weighted member which performs the following functions:
provides means coacting with the arm and a strike bracket on the mailbox door to hold the arm in the horizontal or nonsignaling position;
provides sufficient weight to cause the arm to pivot to the vertical or signaling position due to gravity acting on the member;
pivots with respect to the end of the arm to shift its center of gravity in a manner adapted to maintain the arm in a vertical position; and,
cams with respect to the end of the arm during resetting or cocking of the arm to override the strike bracket.
Another important object is to provide a signaling device having a multifunctional, weighted member whereby the number of parts making up the device comprises an irreducible minimum.
Still another object is to provide an improved signaling device having the aforesaid characteristics which is practical and efficient in its use and operation, which is of simple construction and installation, and which can be mass produced at very low cost.
These and other objects and advantageous features of the invention will become apparent and the invention will be best understood and fully appreciated by having reference to the following detailed description of a preferred embodiment of the invention taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary side elevation of a mailbox with the improved signaling device attached to one side thereof and device in the signaling position;
FIG. 2 is an enlarged fragmentary side elevational view of the signalling device shown in FIG. 1;
FIG. 3 is a fragmentary side elevational view with a portion of the signal arm broken away;
FIG. 4, is a view similar to FIG. 3 wherein the signal arm has been pivoted counterclockwise;
FIG. 5, is a view similar to FIGS. 3 and 4 showing the signal arm in the cocked or non-signaling position;
FIG. 6 is a partial end view of the signaling device in the position shown in FIG. 5; and,
FIG. 7 is a partial sectional view taken along line 7--7 of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
A typical rural mailbox 10 is illustrated in FIG. 1 and generally comprises a curved top wall 12 with depending side panels 14, a flat rear closure wall 16, a flat bottom wall, not shown, and a manually operable front door 18. A pair of mounting feet 20 extend rearwardly from the base of door 18 and are pivotably secured to the opposed side walls 14 by pins or fasteners 22 so that the door 18 may be swung open and closed in a well-understood manner. A bracket 24 is suitably fixed to the upper portion of door 18 and provides an operating handle for the door. For a purpose to be described hereinafter, a strike bracket 26 is attached at the side of the door 18 slightly above its top to bottom centerline. Preferably, the bracket 26 is made by bending a generally rectangular piece of sheet meal to form a tab 28 which extends perpendicularly from the bracket body 30. As shown in FIGS. 5 and 6, the strike bracket 26 is rigidly affixed to the door 18 by securing the tab 28 to the side of door 18 and the body 30 to the door front by means of rivets 32 or other suitable fasteners.
The signaling unit, indicated in its entirety by numeral 34, generally comprises an angularly bent, sheet metal flag 36 secured adjacent the narrower or tailend 38 of a tapered pivot arm 40 which is secured intermediate its ends to a flat side panel 14 of the mailbox 10. The wider or head end 42 of the arm 40 carries a multipurpose, bar-shaped member 44.
As best illustrated in FIG. 7, the pivot arm 40 comprises, in transverse cross section, a U-shaped channel having an arcuate bottom 46 and extending legs 48. As viewed in FIGS. 1 and 2, the channel opens forwardly or toward the door-end of the mailbox 10; and, as viewed in FIGS. 3 through 7, the channel opens upwardly or toward the top of the mailbox. FIG. 7 shows a bolt 50 extending through horizontally aligned openings in the channel legs 48 and mailbox side panel 14, respectively, for securing the arm 40 in swingable relation with the box 10. The end of bolt 50 penetrates the side panel 14 and receives a washer 56 and nut 58. Other washers 60 and a nut 62 are mounted on the bolt 50 to provide adequate spacing between the side panel 14 and the arm 40 and flag 36 to permit the signal unit 34 to swing alongside the mailbox 10.
The head end 42 of the arm 40 is arcuately shaped and is transversly penetrated by a fixed pin 64. The aforementioned bar-shaped member 44 is pivotably mounted intermediate the channel legs 48 on a pivot pin 66 between spacers 68. The pin 66 may comprise a rivet, a bolt or other such means. As shown in FIG. 5, for example, the major sides of member 44 are in the general shape of a rectangle except for a frontal nose 44a which curves downwardly to a tip 44b. For a purpose to be described, the transverse aperture through member 44 which receives the pivot pin 66 is displaced laterally from the longitudinal centerline of the member 44 toward the bottom wall 46 of the arm 40. It will also be noted that this transverse aperture is located forwardly of the lateral centerline of the member 44 or proximate the tip 44b of the member. The member 44 has a substantial thickness and is therefore quite massive and heavy compared to the sheet metal parts of the signaling arm 40.
The head end 42 of member 44 is open between the side walls 48; and, a forwardmost segment of the bottom wall 46 is cut away to permit the nose 44a of member 44 to swing freely about the pivot pin 66 from the position shown in FIG. 5 to that shown in FIG. 2.
The flag 36 may be of any desired shape, size and color which renders it visible from a considerable distance from the site of the mailbox. The preferred embodiment of such flag comprises a rectangle bent along its centerline so that the bent portions are perpendicular. The length of the flag may be quite substantial provided its weight does not become so great that it impedes the operation of the device, as will be described. The flag 36 is rigidly fixed to the tail end 38 of the arm 40 by rivits 70 or like fasteners.
The signaling unit 34 is installed on a standard mailbox by means of the single bolt 50 which pivotably secures the unit to the box. The strike bracket 26 is installed on the door 18 so that, once the signaling unit is in place, the member 44 rests atop the bracket 18 to support the arm 40 and attached flag 36 in the generally horizontal condition shown in FIG. 5. It will be appreciated that the unit 34 and the strike bracket are easily installed by use of simple tools and technics.
OPERATION OF THE INVENTION
In the drawings, FIGS. 1 and 2 show the signaling device in the vertical or tripped condition; and, FIGS. 5, 6 and 7 show the same in the horizontal or cocked or set condition. Assuming that the device is in the cocked or FIG. 5 condition, the forward tip 44b of the member 44 abutts with the top surface of the strike bracket 26. The underside of the member 44 engages with the bottom wall 46 of the arm 40 so that the arm and member coact to prevent the considerable weight of the member from pivoting the signaling unit 34 clockwise about the bolt 50. It is critical to proper operation of the signaling unit that the weight of the member 44 be much greater than that of the flag 36 to insure that the gravitational force available to pivot the arm 40 clockwise about bolt 50 is substantially greater than the opposed force.
When the addressee pivots the mailbox door 18 outwardly about pins 22 to retrieve the mailbox contents, the strike bracket body 30 is moved out of underlying supportive engagement with the nose 44a of member 44; and, the weight of member 44 acting on the pivot arm 40 causes the latter to pivot clockwise about the bolt 50 to the generally vertical or tripped condition shown in FIGS. 1 and 2. As the pivot pin 66 swings downwardly into approximate vertical alignment with the bolt 50, the member 44 will pivot clockwise about pin 66 due to the fact that pin 66 is displaced laterally from the longitudinal centerline of member 44 as noted hereinbefore. This is an important feature of the invention since the location of the center of gravity of the member 44 will be generally vertically aligned with the bolt 50 when the clockwise movement of the member 44 is arrested by striking the pin 64. With the center of gravity of the member 44 so situated, the pivots 50 and 66 lie on a line which is at an angle from vertical; however, the flag 36 will project vertically upwardly above the mailbox top 12 in the manner shown in FIG. 1. It will also be appreciated that the substantial weight of the member 44 will dampen any tendency of the signaling unit 34 to oscillate about bolt 50 due to wind acting on the flag 36.
An important feature of this device resides in its ability to be reset or cocked from the vertical condition shown in FIGS. 1 and 2 to the condition shown in FIG. 5 by the use of only one hand of the operator. First the door 18 is pushed rearwardly to its closed position shown in FIGS. 3,4 and 5 whereby the body 30 of the strike bracket 26 is placed inside the arc of movement of the tip 44b of member 44. Manual force is then applied to either the flag 36 or the arm 40 to rotate the signaling unit 34 counterclockwise about bolt 50. During the course of such counterclockwise rotation from the tripped condition shown in FIG. 2, the tip 44b. of member 44 will strike the bracket body 30, as shown in FIG. 3, arresting the arcuate travel of the tip. As the pivot pin 66 continues to move in a counterclockwise arc about bolt 50, the member 44 will pivot clockwise about pin 66 sufficiently to permit the tip 44b to slide upwardly upon the surface of the bracket body 30 while the rear end 44c of the member 44 pivots upwardly between and beyond the spaced legs 48 of the arm 40. When the tip 44b clears and overrides the extreme upper surface of the strike bracket body 30, the member 44 will pivot counterclockwise about pin 66 due to the weight and long moment arm of the rear end portion 44c of the member 44; and, the arm 40 will pivot clockwise about bolt 50 until the lower surface of the member 44 contacts the bottom 46 of the arm 40 as shown in FIG. 5.
From the foregoing detailed description, it will be appreciated that the member 44 provides in one simply formed part an efficient means for coacting with the arm 40 and the strike bracket 26 to maintain the signaling unit 34 in a nonsignaling condition while it also provides the weight needed for pivoting the arm 40 to the signaling position and thereafter automatically shifts its center of gravity to maintain the signal flag in a preferred vertical position. Finally, the same member 44 cams with respect to the arm 40 during resetting of the arm 40 to override the strike bracket 26.
Another advantageous feature of this invention is the pivot arm 40 which, due to its tapered configuration and open interior construction, coacts with the member 44 to permit the member to project outwardly therefrom at the top, front and bottom of the arm as required to perform its various functions.
The foregoing description of the embodiments of the invention shown in the drawings is illustrative and explanatory only; and, various changes in the size, shape and materials, as well as in specific details of the illustrated construction may be made without departing from the scope of the invention.
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A gravity operated mailbox signaling device which is actuated by opening the mailbox door, is resettable by one hand of an operator, and comprises a minimum number of parts, namely, an elongated signal arm in the form of a U-shaped channel and a single, bar-shaped member of considerable mass and weight. The arm is pivotably attached intermediate its ends to the mailbox; and, the member is pivotably attached to the non-signaling end of the arm and is disposed substantially interiorly of the U-shaped channel. The member coacts with a bracket mounted on the mailbox door to hold the signal arm in its non-signaling condition and to reset the arm after the same has been operated to its signaling condition. The member also shifts its center of gravity as the arm swings to its signaling condition to help maintain the arm in that condition until it is reset.
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FIELD OF THE INVENTION
[0001] The present invention relates to a novel organic compound, a material comprising the same for organic electroluminescence devices, and an organic electroluminescence device comprising the material.
DESCRIPTION OF RELATED ART
[0002] Organic electroluminescence devices are self luminous, can be driven at a low voltage, have very excellent viewing angle, contrast, and others compared with popular liquid crystal displays (LCDs) such as flat panel display devices, require no backlight sources, can achieve light weight and ultrathin thickness, are also very favorable in terms of power consumption, and have wide range of color presentation, thus receiving great attention as the next generation of displays.
[0003] In the structure of an ordinary organic electroluminescence device, an anode is formed on a substrate, and then a hole transport layer, an emission layer, an electron transport layer, and a cathode are sequentially formed on the anode. Here, the hole transport layer, the emission layer, and the electron transport layer are thin films formed of an organic compound.
[0004] The principle for driving the organic electroluminescence devices having the structure above is as follows. When a voltage is applied between the anode and the cathode, holes injected from the anode move via the hole transport layer to the emission layer, and electrons injected from the cathode move via the electron transport layer to the emission layer. Excitons are formed when carriers that are the same as the holes and electrons are recombined in the emission layer, and light is emitted when the excitons fall from the excited state back to the ground state excitons.
[0005] The substances used in the organic electroluminescence device are largely a pure organic substance or a complex formed by an organic compound with a metal. Depending on different uses, the substances may be classified into hole injection substances, hole transport substances, emission substances, electron transport substances, electron injection substances, and so on. Herein, as a hole injection substance or a hole transport substance, an organic substance having a p-type property is mainly used, that is, an organic compound that is prone to oxidation, and is stable in chemical state of electrons upon oxidization. Furthermore, as an electron injection substance or an electron transport substance, an organic substance having an n-type property is mainly used, that is, an organic compound that is prone to reduction, and is stable in chemical state of electrons upon reduction. As an emission layer substance, a substance having both a p-type property and an n-type property is used, preferably a substance that is stable in both oxidized and reduced states is used, and preferably a substance is used which has a high luminous efficiency with respect to conversion of excitons to light when the excitons are formed.
[0006] In addition, the substance used in the organic electroluminescence device preferably has the following additional properties.
[0007] In the first place, the substance used in the organic electroluminescence device preferably has an excellent thermal stability. This is mainly because Joule heating takes place in the organic electroluminescence device, due to the movement of charges. At present, as a hole transport layer substance, TPD or NPB is mainly used, which has a glass transition temperature (Tg) as low as 60° C. and 96° C. respectively. Therefore, based on the above reasons, a fatal disadvantage of short service life of the device is present.
[0008] In the second place, to obtain a high-efficiency organic electroluminescence device driven at a low voltage, the injected holes and electrons need to be prevented from flowing outside of the emission layer, while the holes or electrons injected in the organic electroluminescence device are ensured to flow smoothly to the emission layer. To this end, the substance used in the organic electroluminescence device needs to have appropriate bandgap reference and HOMO or LUMO energy level.
[0009] Moreover, the substance used in the organic electroluminescence device needs to have excellent chemical stability, charge mobility, and interfacial properties with electrodes or adjacent layers. That is, the substance used in the organic electroluminescence device needs to have a small deformation caused by factors including moisture or oxygen. Furthermore, by having an appropriate hole or electron mobility, the hole and electron densities in the emission layer of the organic electroluminescence devices are kept evenly, such that the formation of excitons is maximized. In addition, for the sake of device stability, an interface between electrodes comprising a metal or a metal oxide is well formed.
[0010] To exert the aforesaid excellent properties of the organic electroluminescence device fully, the substance for forming an organic layer in the device, for example, the hole injection substance, the hole transport substance, the emission substance, the electron transport substance, the electron injection substance, and so on, should be a stable and high-efficiency material. However, no stable and high-efficiency organic materials for organic electroluminescence devices are well developed hereto. Therefore, there is a persistent need in the art for developing novel materials with low drive voltage, high efficiency, and long life.
PRIOR ART LITERATURES
Patent Document
[0000]
South Korea Laid-Open Patent Publication No: 10-2011-0103141
SUMMARY OF THE INVENTION
Technical Problem
[0012] An objective of the present invention is to provide a novel organic compound, which can be used in organic electroluminescence devices as a hole injection layer substance, a hole transport layer substance, an electron blocking layer substance, or an emission layer substance, and functions to lower the drive voltage, and increase the luminous efficiency, luminance, thermal stability, color purity, and service life of the devices.
[0013] Another objective of the present invention is to provide a hole injection layer material, a hole transport layer material, an electron blocking layer material, and an emission layer material comprising the novel organic compound.
[0014] A further objective of the present invention is to provide an organic electroluminescence device using the novel organic compound.
Means to Solve the Problem
[0015] The present invention provides a novel organic compound represented by General Formula 1 below:
[0000]
[0016] where Ar1 and Ar3 are the same or different in each case, and are an aromatic or heteroaromatic ring system having 6 to 60 carbon atoms selected from the group consisting of benzene, biphenyl, naphthalene, phenanthrene, fluorene, dibenzofuran, dibenzothiophen (each of which may be substituted with one or more radicals R4), substituted or unsubstituted spirobifluorene, or a combination of 2, 3, 4, or 5 thereof (which are the same or different in each case);
[0017] Ar2 is a heteroaromatic ring system selected from the group consisting of benzene, biphenyl, naphthalene, phenanthrene, fluorene, spirobifluorene, dibenzofuran, and dibenzothiophen (each of which may be substituted with one or more radicals R4);
[0018] R4 is the same or different in each case, and is one selected from the group consisting of H, D, F, CI, Br, I, CN, Si(R) 3 , a linear alkyl, alkoxy or thioalkyl having 1 to 31 carbon atoms or a basin-like alkyl or cycloalkyl, alkoxy, or thioalkyl having 3 to 31 carbon atoms, an aromatic or heteroaromatic ring system having 6 to 40 carbon atoms selected from the group consisting of benzene, naphthalene, phenanthrene, fluorene, spirobifluorene, dibenzofuran, dibenzothiophen or a combination of 2, 3, 4, or 5 thereof (which are the same or different in each case), an aryloxy having 5 to 40 aromatic ring atoms, or an aralkyl having 5 to 40 aromatic ring atoms; and
[0019] R1, R2, R3, and R4 are the same or different in each case, and are selected from H, D, F, Cl, Br, I, CN, Si(R) 3 , a linear alkyl, alkoxy or thioalkyl having 1 to 40 carbon atoms or a basin-like alkyl or cycloalkyl, alkoxy, or thioalkyl having 3 to 40 carbon atoms, an aromatic or heteroaromatic ring system having 6 to 60 carbon atoms selected from the group consisting of benzene, naphthalene, phenanthrene, fluorene, spirobifluorene, dibenzofuran, dibenzothiophen, or a combination of 2, 3, 4, or 5 thereof (which are the same or different in each case), an aryloxy having 5 to 60 aromatic ring atoms, or an aralkyl having 5 to 60 aromatic ring atoms.
[0020] Further, the present invention provides a material comprising the organic compound of General Formula 1 for forming a hole injection layer, a hole transport layer, an electron blocking layer, or an emission layer.
[0021] Moreover, the present invention provides an organic electroluminescence device, which has one or more organic thin film layers, including at least an emission layer, laminated between a cathode and anode. The organic electroluminescence device is characterized in that at least one of the organic thin film layers contains one or two or more of the organic compounds as defined in claim 1 .
Beneficial Effect of the Invention
[0022] The organic compound according to the present invention can be used in organic electroluminescence devices as a hole injection layer substance, a hole transport layer substance, an electron blocking layer substance, and an emission layer substance such as green and red phosphorescent host substance, and when used in the organic electroluminescence devices, can reduce the drive voltage, and increase the luminous efficiency, luminance, thermal stability, color purity and service life of the devices.
[0023] Furthermore, the organic electroluminescence device fabricated by using the organic compound of the present invention has the characteristics of high efficiency and long service life.
DETAILED DESCRIPTION
[0024] The present invention relates to a novel organic compound represented by General Formula 1 below:
[0000]
[0025] where Ar1 and Ar3 are the same or different in each case, and are an aromatic or heteroaromatic ring system having 6 to 60 carbon atoms selected from the group consisting of benzene, biphenyl, naphthalene, phenanthrene, fluorene, dibenzofuran, dibenzothiophen (each of which may be substituted with one or more radicals R4), substituted or unsubstituted spirobifluorene, or a combination of 2, 3, 4, or 5 thereof (which are the same or different in each case);
[0026] Ar2 is a heteroaromatic ring system having 6 to 60 carbon atoms selected from the group consisting of benzene, biphenyl, naphthalene, phenanthrene, fluorene, spirobifluorene, dibenzofuran, and dibenzothiophen (each of which may be substituted with one or more radicals R4);
[0027] R4 is the same or different in each case, and is one selected from the group consisting of H, D, F, CI, Br, I, CN, Si(R) 3 , a linear alkyl, alkoxy or thioalkyl having 1 to 31 carbon atoms or a basin-like alkyl or cycloalkyl, alkoxy, or thioalkyl having 3 to 31 carbon atoms, an aromatic or heteroaromatic ring system having 6 to 60 carbon atoms selected from the group consisting of benzene, naphthalene, phenanthrene, fluorene, spirobifluorene, dibenzofuran, dibenzothiophen, or a combination of 2, 3, 4, or 5 thereof (which are the same or different in each case), an aryloxy having 5 to 40 aromatic ring atoms, or an aralkyl having 5 to 40 aromatic ring atoms;
[0028] R1, R2, and R3 are the same or different in each case, and are selected from H, D, F, Cl, Br, I, CN, Si(R) 3 , a linear alkyl, alkoxy or thioalkyl having 1 to 40 carbon atoms or a basin-like alkyl or cycloalkyl, alkoxy, or thioalkyl having 3 to 40 carbon atoms, an aromatic or heteroaromatic ring system having 6 to 60 carbon atoms selected from the group consisting of benzene, naphthalene, phenanthrene, fluorene, spirobifluorene, dibenzofuran, dibenzothiophen, or a combination of 2, 3, 4, or 5 thereof (which are the same or different in each case), an aryloxy having 5 to 60 aromatic ring atoms, or an aralkyl having 5 to 60 aromatic ring atoms.
[0029] In General Formula 1,
[0030] Ar1 and Ar3 are the same or different in each case, and are an aromatic or heteroaromatic ring system having 6 to 31 carbon atoms selected from the group consisting of benzene, naphthalene, phenanthrene, fluorene, dibenzofuran, dibenzothiophen (each of which may be substituted with one or more radicals R4), and substituted or unsubstituted spirobifluorene;
[0031] Ar2 is a heteroaromatic ring system having 6 to 31 carbon atoms selected from the group consisting of benzene, naphthalene, phenanthrene, fluorene, spirobifluorene, dibenzofuran, and dibenzothiophen (each of which may be substituted with one or more radicals R4); and
[0032] R1, R2, R3, and R4 are the same or different in each case, and are selected from H, D, F, CI, Br, I, CN, Si(R) 3 , a linear alkyl, alkoxy or thioalkyl having 1 to 25 carbon atoms or a basin-like alkyl or cycloalkyl, alkoxy, or thioalkyl having 3 to 25 carbon atoms, an aromatic or heteroaromatic ring system having 6 to 31 carbon atoms selected from the group consisting of benzene, naphthalene, phenanthrene, fluorene, spirobifluorene, dibenzofuran, and dibenzothiophen, an aryloxy having 5 to 31 aromatic ring atoms, or an aralkyl having 5 to 31 aromatic ring atoms.
[0033] Specifically, the organic compound may be one of Compounds 1 to 45:
[0000]
[0034] The organic compound provided in the present invention can be used in organic electroluminescence devices as a hole injection layer material, a hole transport layer material, an electron blocking layer material, and an emission layer material. For example, the emission layer material may be a green or red phosphorescent host material.
[0035] Furthermore, the present invention also relates to a hole injection layer material, a hole transport layer material, an electron blocking layer material, and an emission layer material comprising the organic compound above.
[0036] For facilitating the formation of the hole injection layer, the hole transport layer, the electron blocking layer, and the emission layer, during fabrication, the hole injection layer material, the hole transport layer material, the electron blocking layer material, and the emission layer material can not only be in various states, for example liquid state, but also added with commonly used substances.
[0037] Moreover, the present invention further relates to an organic electroluminescence device, which has one or more organic thin film layers, including an emission layer, deposited between an anode and a cathode. At least one of the organic thin film layers contains one or a combination of two or more of the organic compounds of General Formula 1.
[0038] At least one of the hole injection layer material, the hole transport layer material, the electron blocking layer material, and the emission layer material of the organic electroluminescence device contains the organic compound of General Formula 1.
[0039] The organic electroluminescence device has a structure where the anode, a hole injection layer, a hole transport layer, the emission layer, an electron transport layer, an electron injection layer, and the cathode are laminated. Optionally, an electron blocking layer and a hole blocking layer may be added.
[0040] The organic thin film layers include a hole injection layer, a hole transport layer, the emission layer, an electron transport layer, and an electron injection layer, and the organic compound of General Formula 1 is contained in at least one of the hole injection layer, the hole transport layer, and the emission layer.
[0041] In addition, the organic thin film layers include a hole injection layer, a hole transport layer, the emission layer, an electron transport layer, an electron blocking layer, and an electron injection layer, and the organic compound of General Formula 1 is contained in one of the hole injection layer, the hole transport layer, the electron blocking layer, and the emission layer.
[0042] Hereinafter, the organic electroluminescence device of the present invention is described by way of examples. However, the organic electroluminescence device of the present invention is not limited thereto.
[0043] The organic electroluminescence device of the present invention has a structure comprising the anode (hole injection electrode), a hole injection layer (HIL), a hole transport layer (HTL), the emission layer (EML), and the cathode (electron injection electrode) stacked in sequence. If possible, an electron blocking layer (EBL) may be added between the anode and the emission layer, and a hole blocking layer (HBL) may be added between the cathode and the emission layer.
[0044] The organic electroluminescence device of the present invention is fabricated by a process comprising the following steps.
[0045] Step 1: An anode material is laminated through a conventional process on a surface of a substrate to form an anode. The substrate used is a glass or transparent plastic substrate having good penetrability, surface smoothness, operability, and waterproof performance. Furthermore, the anode material may be transparent and highly conductive ITO, IZO, SnO 2 , and ZnO etc.
[0046] Step 2: A hole injection layer (HIL) material is applied onto a surface of the anode through a conventional process by vacuum thermal deposition or by spin coating. The hole injection layer substance may be, in addition to the organic compound of the present invention, for example, CuPc, m-MTDATA, m-MTDAPB, and starburst amines TCTA, 2-TNATA, or IDE406 commercially available from Idemitsu Kosan Co., Ltd.
[0047] Step 3: A hole transport layer (HTL) material is applied onto a surface of the hole injection layer through a conventional process by vacuum thermal deposition or by spin coating, to form a hole transport layer. The hole transport layer material may be, in addition to the organic compound of the present invention, α-NPD, NPB, or TPD.
[0048] Step 4: An emission layer (EML) material is applied onto a surface of the hole transport layer through a conventional process by vacuum thermal deposition or by spin coating, to form an emission layer. The emission layer material may be the organic compound of the present invention, Tris(8-hydroxyquinolinato)aluminium (Alq 3 ) and the like, when the sole light-emitting substance or light emitting host substance is green; and may be Balq, DPVBi series, spiro substance, spiro-DPVBi, LiPBO, bis(biphenylvinyl)benzene, aluminium-quinoline metal comlex, and compexes of imidazole, thiazole, and oxadiazole with metals, when the sole light-emitting substance or light emitting host substance is blue. The organic compound of the present invention may also be used as a red phosphorescent host substance.
[0049] Further, the emission layer substance may include a dopant used with the light emitting host, and the florescent dopant may be IDE102 and IDE105 commercially available from Idemitsu Kosan Co., Ltd; and the phosphorescent dopant may be Ir(ppy)3, Flrpic (see [Chihaya Adachi et al., Appl. Phys. Lett., 2001, 79, 3082-3084]), PtOEP, and TBE002 (Cobion).
[0050] Further, an electron blocking layer (EBL) may be added between the hole transport layer and the emission layer.
[0051] Step 5: An electron transport layer (ETL) material is applied onto a surface of the emission layer through a conventional process by vacuum thermal deposition or by spin coating, to form an electron transport layer. The electron transport layer material is not particularly limited, and preferably Alq 3 .
[0052] Further, a hole blocking layer (HBL) may also be added between the emission layer and the electron transport layer, which, in combination with the use of a phosphorescent dopant in the emission layer, can prevent the triplet excitons or hole from diffusing into the electron transport layer.
[0053] A hole blocking layer (HBL) material is applied onto a surface of the emission layer through a conventional process by vacuum thermal deposition or by spin coating, to form a hole blocking layer. The hole blocking layer material is not particularly limited, and preferably the organic compound of General Formula 1 of the present invention, Liq, bis(2-methyl-8-quinolinolato)-(1,1′-Biphenyl-4-olato)aluminum, BCP, and LiF etc.
[0054] Step 6: An electron injection layer (EIL) material is applied onto a surface of the electron transport layer through a conventional process by vacuum thermal deposition or by spin coating, to form an electron injection layer. The electron injection layer substance may be LiF, Liq, Li 2 O, BaO, NaCl, CsF, and so on.
[0055] Step 7: A cathode material is applied onto the electron injection layer through a conventional process by vacuum thermal deposition or by spin coating, to form a cathode.
[0056] The cathode material may be Li, Al, Al—Li, Ca, Mg, Mg—In, Mg—Ag, and the like. Furthermore, for the organic electroluminescence devices, a light penetrable transparent cathode can be fabricated when indium tin oxide (ITO) or indium zinc oxide (IZO) is used.
[0057] Further, according to the composition of the overlay above, a capping layer (CPL) may be further formed on a surface of the cathode.
[0058] Hereinafter, methods for synthesizing the compounds of General Formula 1 are described by way of representative examples. However, the methods for synthesizing the compounds of the present invention are not limited to those exemplified below, and the compounds of the present invention may be prepared through the methods exemplified below and methods generally known in the art.
Preparation Process 1: Compound Synthesis
Synthesis of Intermediate 1
[0059]
[0060] Under a nitrogen atmosphere, naphthalenecarboxylic acid (1.72 g, 10 mmol) was dissolved in tetrahydrofuran (10 mL), and mixed with 1.4 M s-butyllithium at −40° C. Then, the cold water bath was removed, and the reaction solution was stood for 30 min in a water bath at room temperature, stirred for 2 hrs, and cooled at −78° C. Tetrahydrofuran (10 mL) containing methanesulfonic acid (1.44 g, 15 mmol) was added dropwise. Then, the cold water bath was removed, and the resulting mixture was stood for 30 min in a water bath at room temperature, and refluxed at 60° C. for 2 hrs.
[0061] After the reaction was terminated, the reaction solution was washed with a saturated sodium chloride solution, and then a 2N aqueous HCl solution was added, stirred for 30 min, and then extracted with diethyl ether.
[0062] The organic layer was dried over anhydrous magnesium sulfate, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=5:1, to obtain Intermediate 1 (0.79 g, 51%).
[0063] Intermediate 1 MS(FAB): 154(M + )
Synthesis of Intermediates 2 and 3
[0064]
[0065] 1-bromo-4-iodonaphthalene (3.33 g, 10 mmol) was dissolved in tetrahydrofuran (15 mL), and cooled to −78° C. n-butyllithium (2.5 M, 4 mL) was added dropwise, and stirred at −78° C. for 1 h. Intermediate 1 (1.54 g, 10 mmol) dissolved in tetrahydrofuran (30 mL) was slowly added dropwise, and warmed to normal temperature. After the reaction was terminated, MC and 2N HCl were added, and the organic layer was extracted.
[0066] The organic layer was dried over anhydrous magnesium sulfate, suctioned under reduced pressure, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=5:1, to obtain Intermediate 2 (2.76 g, 76%).
[0067] Intermediate 2 was dissolved in acetic acid, and then concentrated hydrochloric acid was added dropwise, and refluxed for 1 hr. The reaction was terminated, and extracted with diethyl ether and water. The organic layer was washed with a saturated sodium bicarbonate solution in water, dried over magnesium sulfate, recrystallized, and purified by column chromatography eluting with Hex:EA=4:1, to obtain Intermediate 3 (2.85 g, 83%).
[0068] Intermediate 2 MS(FAB): 363(M + )
[0069] Intermediate 3 MS(FAB): 343(M + )
Synthesis of Intermediates 4 and 5
[0070]
[0071] 3-bromo-1-iodonaphthalene (3.33 g, 10 mmol) was dissolved in tetrahydrofuran (15 ml), and then cooled to −78° C. n-butyllithium (2.5 M, 4 mL) was added dropwise and stirred at −78° C. for 1 hr. Intermediate 1 (1.54 g, 10 mmol) dissolved in tetrahydrofuran (30 ml) was slowly added dropwise, and warmed to normal temperature. After the reaction was terminated, MC and 2N HCl were added, and the organic layer was extracted.
[0072] The organic layer was dried over anhydrous magnesium sulfate, suctioned under reduced pressure, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=5:1, to obtain Intermediate 4 (2.76 g, 75%).
[0073] Intermediate 4 was dissolved in acetic acid, and then concentrated hydrochloric acid was added dropwise, and refluxed for 1 hr. The reaction was terminated, and extracted with diethyl ether and water. The organic layer was washed with a saturated sodium bicarbonate solution in water, dried over magnesium sulfate, recrystallized, and purified by column chromatography eluting with Hex:EA=4:1, to obtain Intermediate 5 (2.75 g, 80%).
Synthesis of Intermediate 6
[0074]
[0075] Under a nitrogen atmosphere, Intermediate 3 (3.43 g, 10 mmol) was dissolved in anhydrous tetrahydrofuran (40 mL), the reactant was cooled to −78° C., and cooled to −78° C. n-butyllithium (2.5 M, 4 mL) was slowly added dropwise, stirred at 0° C. for 1 hr, and then cooled to −78° C. again. Trimethyl borate (12.47 g, 12 mmol) was added dropwise, and stirred for 12 hrs at normal temperature. After the reaction was terminated, a 2 N aqueous HCl solution was added, stirred for 30 min, and extracted with diethyl ether.
[0076] The organic layer was dried over anhydrous magnesium sulfate, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=5:1, to obtain Intermediate 6 (2.43 g, 79%).
Intermediate 6 MS (FAB): 334(M + )
Synthesis of Intermediate 7
[0077]
[0078] Under a nitrogen atmosphere, Intermediate 6 (3.08 g, 10 mmol) and 1-bromo-3-iodobenzene (2.83 g, 10 mmol) were mixed and dissolved in tetrahydrofuran (40 mL). Then Pd(PPh 3 ) 4 (0.58 g, 0.5 mmol) and K 2 CO 3 (2 M, 30 mmol, 15 mL) were added and refluxed for 24 hrs.
[0079] After the reaction was terminated, the reactants were cooled to normal temperature, and MC (200 mL) and H 2 O (200 mL) were added. The MC layer was extracted, dried over anhydrous magnesium sulfate, concentrated, and purified by column chromatography eluting with Hex:EA=5:1, to obtain Intermediate 7 (2.97 g, 71%).
Intermediate 7 MS(FAB): 419(M + )
Synthesis of Intermediate 8
[0080]
[0081] Under a nitrogen atmosphere, Intermediate 6 (3.08 g, 10 mmol) and 1-bromo-4-iodobenzene (2.83 g, 10 mmol) were mixed and dissolved in tetrahydrofuran (40 mL). Pd(PPh 3 ) 4 (0.58 g, 0.5 mmol) and K 2 CO 3 (2 M, 30 mmol, 15 mL) were added and refluxed for 24 hrs.
[0082] After the reaction was terminated, the reactants were cooled to normal temperature, and MC (200 mL) and H 2 O (200 mL) were added. The MC layer was extracted, dried over anhydrous magnesium sulfate, concentrated, and purified by column chromatography eluting with Hex:EA=4:1, to obtain Intermediate 8 (2.89 g, 69%).
[0083] Intermediate 8 MS(FAB): 419(M + )
Synthesis of Intermediate 9
[0084]
[0085] Under a nitrogen atmosphere, phenylboronic acid (1.22 g, 10 mmol) and 4-bromoaniline (1.72 g, 10 mmol) were mixed and dissolved in tetrahydrofuran (20 mL). Pd(PPh 3 ) 4 (0.58 g, 0.5 mmol) and K 2 CO 3 (2 M, 30 mmol, 15 mL) were added and refluxed for 24 hrs.
[0086] After the reaction was terminated, the reactants were cooled to normal temperature, and MC (200 mL) and H 2 O (200 mL) were added. The organic layer was distilled under reduced pressure and then purified by column chromatography eluting with Hex:MC=5:1, to obtain Intermediate 9 (1.20 g, 71%).
[0087] Intermediate 9 MS(FAB): 169(M + )
Synthesis of Intermediate 10
[0088]
[0089] Under a nitrogen atmosphere, Intermediate 9 (1.69 g, 10 mmol) and 2-bromo-9,9-dimethyl-9H-fluorene (2.73 g, 10 mmol) were mixed and dissolved in toluene (30 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (1 M, 0.4 ml, 0.4 mmol), and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 5 hrs.
[0090] After the reaction was terminated, the reactants were cooled to normal temperature, and MC (200 mL) and H 2 O (200 mL) were added. After extraction, the organic layer was dried over anhydrous magnesium sulfate to remove a small amount of water contained therein, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:MC=5:1, to obtain Intermediate 10 (2.57 g, 71%).
[0091] Intermediate 10 MS(FAB): 361(M + )
Synthesis of Intermediate 11
[0092]
[0093] Under a nitrogen atmosphere, 2-methylphenylboronic acid (1.34 g, 10 mmol) and 3-bromoaniline (1.72 g, 10 mmol) were mixed and dissolved in tetrahydrofuran (20 mL). Pd(PPh 3 ) 4 (0.58 g, 0.5 mmol) and K 2 CO 3 (2 M, 30 mmol, 15 mL) were added and refluxed for 24 hrs.
[0094] After the reaction was terminated, the reactants were cooled to normal temperature, and toluene (200 mL) and H 2 O (200 mL) were added. The MC layer was extracted, and the organic layer was distilled under reduced pressure and purified by column chromatography eluting with Hex:MC=5:1, to obtain Intermediate 11 (1.25 g, 68%).
[0095] Intermediate 11 MS(FAB): 183(M + )
Synthesis of Intermediate 12
[0096]
[0097] Under a nitrogen atmosphere, Intermediate 11 (1.83 g, 10 mmol) and 2-bromo-9,9-dimethyl-9H-fluorene (2.73 g, 10 mmol) were mixed and dissolved in toluene (30 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (1 M, 0.4 ml, 0.4 mmol), and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 5 hrs.
[0098] After the reaction was terminated, the reactants were cooled to normal temperature, and toluene (200 mL) and H 2 O (200 mL) were added. After extraction, the organic layer was dried over anhydrous magnesium sulfate to remove a small amount of water contained therein, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:MC=5:1, to obtain Intermediate 12 (2.44 g, 65%).
[0099] Intermediate 12 MS(FAB): 375(M + )
Synthesis of Intermediate 13
[0100]
[0101] Under a nitrogen atmosphere, 2,7-dibromo-9,9-dimethyl-9H-fluorene (3.52 g, 10 mmol) and phenylboronic acid (1.22 g, 10 mmol) were mixed and dissolved in tetrahydrofuran (25 mL). Then Pd(PPh 3 ) 4 (0.58 g, 0.5 mmol) and K 2 CO 3 (2 M, 30 mmol, 15 mL) were added and refluxed for 24 hrs.
[0102] After the reaction was terminated, MC (200 mL) and H 2 O (200 mL) were added. The MC layer was extracted, dried over anhydrous magnesium sulfate, concentrated, and purified by column chromatography eluting with Hex:MC=5:1, to obtain Intermediate 13 (2.13 g, 61%).
[0103] Intermediate 13 MS(FAB): 349(M + )
Synthesis of Intermediate 14
[0104]
[0105] Under a nitrogen atmosphere, Intermediate 9 (1.69 g, 10 mmol) and Intermediate 13 (3.49 g, 10 mmol) were dissolved in toluene (40 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (1 M, 0.4 ml, 0.4 mmol), and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 5 hrs.
[0106] After the reaction was terminated, the reactants were cooled to normal temperature, and toluene (300 mL) and H 2 O (300 mL) were added. After extraction, the organic layer was dried over anhydrous magnesium sulfate to remove a small amount of water contained therein, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=4:1, to obtain Intermediate 14 (2.98 g, 68%).
[0107] Intermediate 14 MS(FAB): 437(M + )
Synthesis of Intermediate 15
[0108]
[0109] Under a nitrogen atmosphere, Intermediate 11 (1.83 g, 10 mmol) and Intermediate 13 (3.49 g, 10 mmol) were mixed and dissolved in toluene (35 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (1 M, 0.4 ml, 0.4 mmol), and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 5 hrs.
[0110] After the reaction was terminated, the reactants were cooled to normal temperature, and toluene (200 mL) and H 2 O (200 mL) were added. After extraction, the organic layer was dried over anhydrous magnesium sulfate to remove a small amount of water contained therein, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=4:1, to obtain Intermediate 15 (2.85 g, 63%).
[0111] Intermediate 15 MS(FAB): 451(M + )
Synthesis of Intermediate 16
[0112]
[0113] Under a nitrogen atmosphere, dibenzofuran (1.68 g, 10 mmol) was dissolved in tetrahydrofuran (10 mL), and mixed with n-BuLi (2.5 M, 4 mL) at −40° C. The cooling device was removed, and the reaction solution was placed in a water bath and warmed to room temperature in about 30 min, and then stirred for 2 hrs. Then, the reaction solution was cooled to −78° C., and 1,2-dibromoethane (2.82 g, 15 mmol) in tetrahydrofuran (10 mL) was added dropwise. The cooling device was removed, and the mixture was placed in a water bath and warmed to room temperature in about 30 min, and then stood for 2 hrs.
[0114] After the reaction was terminated, the reaction solution was washed with a saturated sodium chloride solution, taken up in a 2 N aqueous HCl solution, stirred for 30 min, and extracted with diethyl ether.
[0115] The organic layer was dried over anhydrous magnesium sulfate to remove a small amount of water contained therein, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=5:1, to obtain Intermediate 16 (1.83 g, 74%).
[0116] Intermediate 16 MS(FAB): 247(M + )
Synthesis of Intermediate 17
[0117]
[0118] Under a nitrogen atmosphere, Intermediate 9 (1.69 g, 10 mmol) and Intermediate 16 (2.47 g, 10 mmol) were dissolved in toluene (30 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (1 M, 0.4 ml, 0.4 mmol), and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 5 hrs.
[0119] After the reaction was terminated, the reactants were cooled to normal temperature, and toluene (200 mL) and H 2 O (200 mL) were added. After extraction, the organic layer was dried over anhydrous magnesium sulfate to remove a small amount of water contained therein, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=5:1, to obtain Intermediate 17 (2.45 g, 73%).
[0120] Intermediate 17 MS(FAB): 335(M + )
Synthesis of Intermediate 18
[0121]
[0122] Under a nitrogen atmosphere, Intermediate 16 (2.47 g, 10 mmol) was dissolved in anhydrous tetrahydrofuran (40 mL), and then cooled to −78° C. n-butyllithium (2.5 M, 4 mL) was slowly added dropwise, stirred at 0° C. for 1 hr, and then cooled to −78° C. again. Trimethyl borate (12.47 g, 12 mmol) was added dropwise, and stirred for 12 hrs at normal temperature. After the reaction was terminated, a 2N aqueous HCl solution was added, stirred for 30 min, and extracted with diethyl ether.
[0123] The organic layer was dried over anhydrous magnesium sulfate, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=5:1, to obtain Intermediate 18 (1.55 g, 73%).
Intermediate 18 MS (FAB): 212(M + )
Synthesis of Intermediate 19
[0124]
[0125] Under a nitrogen atmosphere, Intermediate 18 (2.12 g, 10 mmol) and 1-bromo-3-iodobenzene (2.83 g, 10 mmol) were dissolved in tetrahydrofuran (30 ml). Pd(PPh 3 ) 4 (0.58 g, 0.5 mmol) and K 2 CO 3 (2 M, 30 mmol, 15 mL) were added and refluxed for 24 hrs.
[0126] After the reaction was terminated, the reactants were cooled to normal temperature, and MC (200 mL) and H 2 O (200 mL) were added. The MC layer was extracted, dried over anhydrous magnesium sulfate, concentrated, and purified by column chromatography eluting with Hex:EA=5:1, to obtain Intermediate 19 (2.23 g, 69%).
Intermediate 19 MS(FAB): 323 (M + )
Synthesis of Intermediate 20
[0127]
[0128] Under a nitrogen atmosphere, Intermediate 9 (1.69 g, 10 mmol) and Intermediate 19 (3.23 g, 10 mmol) were mixed and dissolved in toluene (40 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (1 M, 0.4 ml, 0.4 mmol), and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 5 hrs.
[0129] After the reaction was terminated, the reactants were cooled to normal temperature, and toluene (200 mL) and H 2 O (200 mL) were added. After extraction, the organic layer was dried over anhydrous magnesium sulfate to remove a small amount of water contained therein, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=4:1, to obtain Intermediate 20 (3.13 g, 76%).
[0130] Intermediate 20 MS(FAB): 411(M + )
Synthesis of Intermediate 21
[0131]
[0132] Under a nitrogen atmosphere, Intermediate 9 (1.69 g, 10 mmol) and 3-bromo-9-phenyl-9H-carbazolyl (3.22 g, 10 mmol) were mixed and dissolved in toluene (40 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (1 M, 0.4 ml, 0.4 mmol), and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 5 hrs.
[0133] After the reaction was terminated, the reactants were cooled to normal temperature, and toluene (200 mL) and H 2 O (200 mL) were added. After extraction, the organic layer was dried over anhydrous magnesium sulfate to remove a small amount of water contained therein, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=4:1, to obtain Intermediate 21 (3.20 g, 78%).
[0134] Intermediate 21 MS(FAB): 410(M + )
Synthesis of Intermediate 22
[0135]
[0136] Under a nitrogen atmosphere, 4-bromo-2-iodo-1-nitrobenzene (3.28 g, 10 mmol) and phenylboronic acid (1.22 g, 10 mmol) were mixed and dissolved in tetrahydrofuran (25 mL). Pd(PPh 3 ) 4 (0.58 g, 0.5 mmol) and K 2 CO 3 (2 M, 30 mmol, 15 mL) were added and refluxed for 24 hrs.
[0137] After the reaction was terminated, MC (200 mL) and H 2 O (200 mL) were added. The MC layer was extracted, dried over anhydrous magnesium sulfate, concentrated, and purified by column chromatography eluting with Hex:MC=5:1, to obtain Intermediate 22 (1.97 g, 71%).
[0138] Intermediate 22 MS(FAB): 278(M + )
Synthesis of Intermediate 23
[0139]
[0140] Under a nitrogen atmosphere, Intermediate 22 (2.78 g, 10 mmol) was dissolved in o-DCB (40 mL), and then triphenylphosphine (6.56 g, 25 mmol) was added and refluxed.
[0141] After the reaction was terminated, MC (200 mL) and H 2 O (200 mL) were added. The MC layer was extracted, dried over anhydrous magnesium sulfate, concentrated, and purified by column chromatography eluting with Hex:MC=5:1, to obtain Intermediate 23 (1.94 g, 79%).
[0142] Intermediate 23 MS(FAB): 246(M + )
Synthesis of Intermediate 24
[0143]
[0144] Under a nitrogen atmosphere, Intermediate 23 (2.46 g, 10 mmol) was dissolved in anhydrous tetrahydrofuran (40 mL), and then cooled to −78° C. n-butyllithium (2.5 M, 4 mL) was slowly added dropwise, stirred at 0° C. for 1 hr, and then cooled to −78° C. again. Trimethyl borate (12.47 g, 12 mmol) was added dropwise, and stirred for 12 hrs at normal temperature. After the reaction was terminated, a 2N aqueous HCl solution was added, stirred for 30 min, and extracted with diethyl ether.
[0145] The organic layer was dried over anhydrous magnesium sulfate, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=5:1, to obtain Intermediate 24 (1.56 g, 74%).
[0146] Intermediate 24 MS(FAB): 211(M + )
Synthesis of Intermediate 25
[0147]
[0148] Under a nitrogen atmosphere, Intermediate 24 (2.11 g, 10 mmol) and iodobenzene (2.04 g, 10 mmol) were mixed and dissolved in tetrahydrofuran (30 mL). Pd(PPh 3 ) 4 (0.58 g, 0.5 mmol) and K 2 CO 3 (2 M, 30 mmol, 15 mL) were added and refluxed for 24 hrs.
[0149] After the reaction was terminated, the reactants were cooled to normal temperature, and MC (200 mL) and H 2 O (200 mL) were added. The MC layer was extracted, dried over anhydrous magnesium sulfate, concentrated, and purified by column chromatography eluting with Hex:EA=5:1, to obtain Intermediate 25 (1.73 g, 71%).
[0150] Intermediate 25 MS(FAB): 243(M + )
Synthesis of Intermediate 26
[0151]
[0152] Under a nitrogen atmosphere, Intermediate 25 (2.43 g, 10 mmol) and 4-bromo-4′-iodo-1, l′-biphenyl (5.39 g, 15 mmol) were dissolved in nitrobenzene (50 mL) K 2 CO 3 (4.15 g, 30 mmol) and Cu (0.19 g, 3 mmol) were added and refluxed for 16 hrs.
[0153] After the reaction was terminated, nitrobenzene was removed by distillation, and MC (200 mL) and H 2 O (200 mL) were added. The MC layer was extracted, dried over anhydrous magnesium sulfate, concentrated, and purified by column chromatography eluting with Hex:EA=3:1, to obtain Intermediate 26 (3.65 g, 77%).
[0154] Intermediate 26 MS(FAB): 474(M + )
Synthesis of Intermediate 27
[0155]
[0156] Under a nitrogen atmosphere, Intermediate 9 (1.69 g, 10 mmol) and Intermediate 26 (4.74 g, 10 mmol) were mixed and dissolved in toluene (50 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (1 M, 0.4 ml, 0.4 mmol), and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 7 hrs.
[0157] After the reaction was terminated, the reactants were cooled to normal temperature, and toluene (300 mL) and H 2 O (300 mL) were added. After extraction, the organic layer was dried over anhydrous magnesium sulfate to remove a small amount of water contained therein, suctioned, and concentrated. The resultant compound was purified by column chromatography eluting with Hex:EA=3:1, to obtain Intermediate 27 (4.05 g, 72%).
[0158] Intermediate 27 MS(FAB): 562(M + )
Synthesis of Compound [2]
[0159]
[0160] Under a nitrogen atmosphere, Intermediate 3 (3.43 g, 10 mmol) and Intermediate 10 (3.61 g, 10 mmol) were dissolved in toluene (50 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (0.4 ml, 0.4 mmol) and t-BuONa (2.88 g, 30 mmol), were added and refluxed for 12 hrs.
[0161] After the reaction was terminated, MC (300 mL) and H 2 O (300 mL) were added. The MC layer was extracted, and the organic layer was suctioned and purified by column chromatography eluting with Hex:MC=3:1, to obtain Compound 2 (5.05 g, 81%).
[0162] 1 H NMR (DMSO, 300 Hz): δ(ppm)=8.21-8.10 (m, 1H), 8.10-7.80 (m, 2H), 7.75-6.90 (m, 20H), 6.90-6.55 (m, 4H), 1.35 (s, 6H).
[0163] MS(FAB): 623(M + ).
Synthesis of Compound [5]
[0164]
[0165] Under a nitrogen atmosphere, Intermediate 5 (3.43 g, 10 mmol) and Intermediate 10 (3.61 g, 10 mmol) were dissolved in toluene (50 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (0.4 ml, 0.4 mmol) and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 12 hrs.
[0166] After the reaction was terminated, MC (300 mL) and H 2 O (300 mL) were added. The MC layer was extracted, and the organic layer was suctioned and purified by column chromatography eluting with Hex:MC=3:1, to obtain Compound 5 (5.11 g, 82%).
[0167] 1 H NMR (DMSO, 300 Hz): δ(ppm)=8.21-8.07 (m, 1H), 8.07-7.75 (m, 2H), 7.75-6.90 (m, 20H), 6.90-6.55 (m, 4H), 1.35 (s, 6H)
[0168] MS(FAB): 623(M + )
Synthesis of Compound [15]
[0169]
[0170] Under a nitrogen atmosphere, Intermediate 3 (3.43 g, 10 mmol) and Intermediate 17 (3.61 g, 10 mmol) were mixed and dissolved in toluene (50 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (0.4 ml, 0.4 mmol) and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 12 hrs.
[0171] After the reaction was terminated, MC (400 mL) and H 2 O (400 mL) were added. The MC layer was extracted, and the organic layer was suctioned and purified by column chromatography eluting with Hex:MC=2:1, to obtain Compound 15 (4.30 g, 72%).
[0172] 1 H NMR (DMSO, 300 Hz): δ(ppm)=8.23-8.09 (m, 1H), 8.09-7.78 (m, 2H), 7.73-6.88 (m, 20H), 6.88-6.55 (m, 4H).
[0173] MS(FAB): 597(M + ).
Synthesis of Compound [24]
[0174]
[0175] Under a nitrogen atmosphere, Intermediate 3 (3.43 g, 10 mmol) and Intermediate 26 (3.35 g, 10 mmol) were mixed and dissolved in toluene (40 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (0.4 ml, 0.4 mmol) and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 12 hrs.
[0176] After the reaction was terminated, MC (300 mL) and H 2 O (300 mL) were added. The MC layer was extracted, and the organic layer was suctioned and purified by column chromatography eluting with Hex:MC=3:1, to obtain Compound 24 (4.64 g, 69%).
[0177] 1 H NMR (DMSO, 300 Hz): δ(ppm)=8.40-8.00 (m, 5H), 8.00-7.80 (m, 1H), 7.80-6.90 (m, 24H), 6.90-6.55 (m, 4H)
[0178] MS(FAB): 672(M + )
Synthesis of Compound [37]
[0179]
[0180] Under a nitrogen atmosphere, Intermediate 3 (3.43 g, 10 mmol) and Intermediate 27 (4.11 g, 10 mmol) were mixed and dissolved in toluene (60 mL). Pd 2 dba 3 (0.18 g, 0.2 mmol), t-Bu 3 P (0.4 ml, 0.4 mmol), and t-BuONa (2.88 g, 30 mmol) were added and refluxed for 12 hrs.
[0181] After the reaction was terminated, MC (300 mL) and H 2 O (300 mL) were added. The MC layer was extracted, and the organic layer was suctioned and purified by column chromatography eluting with Hex:MC=3:1, to obtain Compound 37 (5.28 g, 64%).
[0182] 1 H NMR (DMSO, 300 Hz): δ(ppm)=8.40-8.00 (m, 5H), 8.00-7.85 (m, 1H), 7.85-6.90 (m, 30H), 6.90-6.55 (m, 4H).
[0183] MS(FAB): 825(M + ).
[0184] Compounds 1 to 45 of General Formula 1 can be prepared following the processes described in Reaction equations 1-30.
[0185] Hereinafter, the present invention is described in further detail with reference to examples. However, the examples are merely illustrative of the present invention specifically, and the protection scope of the present invention is not limited thereto. Appropriate modifications and changes may be made to the examples by those skilled in the art without departing from the protection scope of the present invention.
Examples 1-16: Fabrication of Organic Electroluminescence Devices
[0186] An ITO anode (5 Ω/cm 2 , 1200 Å) coated glass substrate was cut to have a size of 45 mm×45 mm×0.7 mm, ultrasonicated for 5 min in isopropanol and pure water, rinsed for 30 min with ozone under UV irradiation, and then disposed on a vacuum coating equipment.
[0187] On the top of the ITO coating, 2-TNATA was deposited to form a hole injection layer of 300 Å in thickness; and a corresponding ingredient was selected from Compounds 2, 5, 6, 7, 15, 17, 21, 24, 27, 28, 30, 34, 37, 41, and 45 of the present invention and deposited under vacuum on a surface of the hole injection layer, to form a hole transport layer of 900 Å in thickness.
[0188] Then, AND and DPAVBi were deposited at a weight ratio of 97:3 under vacuum on a surface of the hole transport layer, to form an emission layer of 300 Å in thickness.
[0189] Then, Alq 3 was deposited on a surface of the emission layer, to form an electron transport layer of 300 Å in thickness; LiF was deposited on a surface of the electron transport layer, to foam an electron injection layer of 10 Å in thickness; Al was deposited on a surface of the electron injection layer, to form a second electrode (cathode) of 1000 Å in thickness. In this way, an organic electroluminescence device was obtained. The organic electroluminescence device was sealed with a water absorbing material containing a UV curable binder on a surface of the cathode, to protect the organic electroluminescence device from being influenced by oxygen or moisture in the atmosphere.
[0000]
Comparative Example 1: Fabrication of Organic Electroluminescence Device
[0190] This example was the same as Example 1 except that α-NPD was used as the electron transport layer in place of the compound of the present invention.
Experiment Example 1: Characteristic Evaluation of Organic Electroluminescence Devices
[0191] The characteristics of the organic electroluminescence devices 1 to 16 fabricated in the examples and the organic electroluminescence device fabricated in the comparative example were determined at a current density of 10 mA/cm 2 . The results are shown in Table 1.
[0000]
TABLE 1
Lumi-
nous
Current
Volt-
effi-
density
age
ciency
CIE system
Material
(mA/cm 2 )
(V)
(Cd/A)
(X Y)
Comparative
NPD
10
4.1
4.50
(0.150 0.090)
Example 1
Example1
Compound
10
3.9
7.21
(0.149 0.089)
1
Example2
Compound
10
4.1
7.53
(0.150 0.089)
2
Example3
Compound
10
4.0
7.43
(0.150 0.087)
5
Example4
Compound
10
3.9
6.87
(0.151 0.090)
6
Example5
Compound
10
4.0
7.62
(0.150 0.089)
7
Example6
Compound
10
3.9
7.51
(0.150 0.089)
15
Example7
Compound
10
3.8
7.65
(0.148 0.089)
17
Example8
Compound
10
3.9
7.51
(0.150 0.088)
21
Example9
Compound
10
4.1
7.49
(0.149 0.089)
24
Example10
Compound
10
4.0
7.66
(0.150 0.089)
27
Example11
Compound
10
3.9
7.39
(0.149 0.089)
28
Example12
Compound
10
3.9
7.45
(0.150 0.088)
30
Example13
Compound
10
4.0
7.58
(0.150 0.090)
34
Example14
Compound
10
3.9
7.52
(0.150 0.089)
37
Example15
Compound
10
3.9
7.33
(0.150 0.090)
41
Example16
Compound
10
4.0
7.61
(0.150 0.090)
45
[0192] It can be seen from the experimental results in Table 1 that the organic electroluminescence devices fabricated in Example 1 to 16 of the present invention have obviously increased luminous efficiency, compared with the existing electroluminescence device fabricated in Comparative Example 1.
[0193] Further, it can be known from the experimental results above that for the examples where the organic compound of the present invention is used as a hole transport substance, the luminous efficiency of the organic electroluminescence devices is improved. Therefore, the organic compound of the present invention enables the device to be driven at a reduced voltage, and can reduce the power consumption as well. Furthermore, the luminous service of the organic electroluminescence devices is also enhanced.
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The present invention provides a novel organic compound, a material comprising the same for organic electroluminescence devices, and an organic electroluminescence device comprising the material. The organic compound provided in the present invention is useful in organic electroluminescence devices as a hole injection layer material, a hole transport layer material, an electron blocking layer material, and an emission layer material such as green and red phosphorescent host material, and can reduce the drive voltage, and increase the luminous efficiency, luminance, thermal stability, color purity and service life of the devices.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No. 12/065,856, filed Mar. 5, 2008 which is a National Stage completion of PCT/EP2006/007430, filed Jul. 27, 2008 which claims priority to DE 10 2005 042 406.6, filed Sep. 6, 2005.
TECHNICAL FIELD
[0002] The invention relates to a filter arrangement, comprising a filter and a sensor device disposed downstream of the filter for monitoring the service life of the filter, having at least one first measuring sensor for detecting the flow velocity of the fluid flowing through the filter.
STATE OF THE ART
[0003] Filter arrangements of this type are known from DE 101 40 510 A 1. Filter systems, such as those in air conditioning systems, have limited fan power, so that the volume flow pumped through the air conditioning system decreases as the particle load of the filter increases. With a sensor device disposed downstream of the filter, having a measuring sensor for detecting the flow velocity, the clogging level of the filter can be determined and a necessary replacement of the filter can be indicated. The filtration of moist air may result in condensation in the filter. The condensation deposited in the filter likewise reduces the volume flow. However, in this case, it is not necessary to replace the filter because the filter can be regenerated by drying. Loading with water, however, cannot be detected only by velocity measurement.
DESCRIPTION OF THE INVENTION
[0004] It is therefore the object of the invention to provide a filter arrangement with improved service life monitoring.
[0005] In order to solve the task, the sensor device comprises a further measuring sensor for measuring the humidity of the fluid flowing through the filter. The measuring sensor detects the load of the fluid with water. Moisture readings close to the saturation limit indicate that the filter is laden with water. Both readings are evaluated in an evaluation unit, wherein the readings of the moisture sensor bring about an error correction of the flow velocity readings. A further source for errors is the sensitivity of the flow velocity measuring element toward moisture. In particular flow measurement sensors that are formed by measuring wires made of electric resistance material are sensitive toward moisture. The measured air velocity is accordingly dependent on the moisture level. This measurement deviation is compensated for by the simultaneous measurement of the moisture level in a further measuring sensor, and the cross-sensitivity of the air velocity meter toward moisture is reduced. Due to the arrangement on the clean air side, the sensor device is protected from clogging.
[0006] The sensor devices may comprise an additional measuring sensor for measuring the temperature of the fluid flowing through the filter. As a result of the temperature sensor, potential cross-sensitivity of the air velocity meter toward temperature fluctuations can be compensated for. In this embodiment, the two essential parameters for controlling an air conditioning system are captured. The readings captured with the inventive sensor device can be provided to an air conditioning controller in order to regulate the air conditioning system. It is advantageous that the sensor device is easily accessible and replaceable and that the sensor device is attached to the filter in a simple manner.
[0007] The sensor device can be configured as a preassembled unit. This results in a compact and easy-to-install sensor element. The connection of the measuring sensors to the evaluation unit is advantageously established by means of a single plug connection.
[0008] The sensor device can be configured as an injection molded part. Injection molded parts are cost-efficient to produce, even if they have complicated geometries. The measuring sensors are then securely fixed in the injection molded housing.
[0009] The sensor device may be disposed at a distance to the filter. The distance is advantageously between 3 and 10 cm. As a result of the distance, the influence of the filter on the fluid flow is reduced, and it is possible to mix the fluid flow, achieving improved measuring accuracy.
[0010] The filter may comprise an injection molded frame. The sensor device can be attached particularly easily to the plastic frame.
[0011] The sensor device may be attached to the filter non-positively or positively. This produces a detachable connection, so that the filter and sensor device can be replaced independently from each other. The connection can be established by a snap-fit connection, for example. The necessary distance between the sensor device and filter can be created by a cross-member.
[0012] The sensor device may be connected to the filter by a material bond. This captively fastens the sensor device to the filter and makes the production of the unit comprising the sensor element and filter cost-efficient. The necessary distance between the sensor device and filter can be created by a cross-member made of a single material.
[0013] According to the invention, the filter arrangement is used as a cabin air filter in a motor vehicle. Due to the integration of the sensor device in a filter, the filter arrangement has a particularly compact design and is especially easy to install and replace. As a result of the improved monitoring of the service life, unnecessary maintenance is avoided. Furthermore, the readings can be used for optimization and filter design purposes, for example in order to save installation space in enhanced models.
[0014] A further use according to the invention is the provision of the filter arrangement in an inflow of a fuel cell. The arrangement in a PEM fuel cell is particularly advantageous because this cell requires moist inflow to achieve the best possible efficiency. Moistening is frequently achieved by means of a humidifier, for example a membrane humidifier. When providing the filter arrangement according to the invention upstream of a humidifier, the data detected by the sensor device, particularly the moisture of the inflow that is measured, can be used to control the humidifier. The sensor device is disposed particularly compact and easily accessibly in the filter arrangement.
[0015] A further advantageous use is the application of the inventive filter arrangement in a mobile device, such as an ambient air purifier. By integrating a sensor in a filter arrangement, a particularly compact design is achieved, which is required for mobile devices.
[0016] Furthermore, the filter arrangement according to the invention may advantageously be integrated in the filter systems/filter covers of paint systems. For high-quality painting work, the supply of low-particle air is required. The inventive filter arrangement enables continuous monitoring of the air quality.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] A few embodiments of the inventive filter arrangement will be explained in more detail hereinafter with reference to the figures. They are schematic illustrations:
[0018] FIG.1 is a filter arrangement comprising a sensor device attached by material bond;
[0019] FIG.2 is a filter arrangement comprising a sensor device attached positively.
EXECUTION OF THE INVENTION
[0020] FIG. 1 shows a filter arrangement 1 , which is used as a cabin air filter in a motor vehicle or as a filter in an inflow of a PEM fuel cell. The filter arrangement is made of a filter 2 and a sensor device 3 , which is disposed downstream of the filter 2 , which is to say on the clean air side. The sensor device on the one hand serves the monitoring of the service life of the filter 2 and on the other hand supplies the on-board electronic system, for example the control system of the motor vehicle air conditioning system, with the detected readings. The sensor device 3 comprises a first measuring sensor 4 , which is formed by measuring wires made of electric resistance material 9 and serves the detection of the flow velocity of the fluid 5 flowing through the filter 2 . Furthermore, the sensor device 3 comprises a further measuring sensor 6 , which is equipped to measure the moisture of the fluid 5 flowing through the filter 2 . An additional measuring sensor 7 , which is equipped to measure the temperature of the fluid 5 flowing through the filter 2 , is likewise provided in the sensor device 3 . The filter 2 is provided with a frame 8 , which is configured as an injection molded part. The sensor device 3 is produced as one piece with the frame 8 and is made of the same material, wherein the measuring sensors 4 , 6 , 7 are firmly embedded in the injection molded sensor device 3 . The sensor element 3 is fastened to the frame 8 at a distance to the filter 2 . Furthermore, the sensor device 3 has an oblong configuration, so that the measuring sensors 4 , 6 , 7 protrude into the free flow and a falsification of the readings by marginal influences is prevented.
[0021] FIG. 2 shows a filter arrangement according to FIG. 1 , wherein the sensor device 3 is configured as a separate element and forms a preassembled unit. In this embodiment, the sensor device 3 is likewise configured as an injection molded part. The frame 8 comprises a recess 10 , into which the sensor device 3 is inserted, wherein the sensor device 3 is positively fixed to the filter 2 by snap-fit elements 11 . In other embodiments, the sensor device 3 may also be fastened to the filter 2 non-positively, for example by means of a screw connection.
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A method of providing error correction to flow velocity readings of a fluid flowing through a filter arrangement for monitoring the service life of the filter, wherein a filter arrangement, comprising a filter and a sensor device is arranged downstream of the filter, the sensor device including at least one measuring sensor for detecting the flow velocity of the fluid which flows through the filter, and a further measuring sensor for measuring the air humidity of the fluid which flows through the filter. A reading of said second sensor element provides an error correction to the first sensor element.
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CLAIM OF PRIORITY
This application claims the benefit of priority under 35 U.S.C. §119(e) to U.S. provisional application Ser. No. 61/842,389, filed Jul. 3, 2013, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
The technology described herein generally relates to optical coherence tomography systems, and more particularly relates to such systems based on vertical cavity surface emitting laser devices.
BACKGROUND
Optical Coherence Tomography (OCT) is a technique for high-resolution depth profiling of a sample (biological samples such as tissues, organs, living bodies, or industrial samples such as polymers, thin-films). There are two types of OCT, namely, a time-domain OCT (TD-OCT), and a frequency-domain OCT (FD-OCT). In TD-OCT, the broadband light source is typically a superluminescent diode, which simultaneously emits multiple wavelengths; by scanning the position of a reference mirror, the frequencies of interference components in the reflecting light from the sample are analyzed. In FD-OCT, a swept source type OCT (SS-OCT), which employs a wavelength tunable laser as the broadband source, has become more widely used. In SS-OCT, only one wavelength is present at any one time, and sweeping of the laser wavelength replaces the mechanical scanning of the reference mirror. The signal to noise ratio of SS-OCT is fundamentally better than that of TD-OCT.
For a tunable laser for use in SS-OCT, requirements include: single-mode operation, a wide tuning range, high scan rate of wavelength, and wavelength tuning that is a simple monotonic function of a tuning control signal.
A tunable VCSEL with a MEMS that utilizes two distributed Bragg reflectors (DBR) has been reported. Such a device employs a bottom mirror consisting of a lower DBR composed of multiple alternating layers of AlGaInAs and InP, and an active layer composed of InP-based multiple quantum wells (MQWs) and barriers, which are all grown on a InP substrate, and a MEMS tunable upper DBR. The device has a tuning range of 55 nm at a center wavelength around 1550 nm. This tuning range is not sufficient for a number of applications.
FIG. 1 illustrates such a tunable VCSEL with MEMS, as known in the art. On a InP substrate 1 , a n-doped distributed Bragg reflector (DBR) 2 consisting of over 40 pairs (not all shown) of alternating layers of AlGaInAs 2 a (lattice-matched to InP) and InP 2 b are epitaxially grown, followed by a n-type AlGaInAs cladding layer 3 . On the top of the cladding layer 3 , an active layer 4 consisting of multiple (six) AlGaInAs quantum wells (“QWs”) 4 a and multiple (seven) AlGaInAs barriers 4 b are grown, followed by a p-type AlGaInAs cladding layer 5 . Above the p-type cladding layer 5 , a p ++ -doped-AlGaInAs/n ++ -doped-AlGaInAs tunnel junction layer 6 is grown to allow the replacement of a p-type InP layer with a n-doped InP layer since the tunnel junction can convert electrons to holes, which is followed by a n-doped InP layer 7 and a n ++ -doped GaInAs contact layer 8 . VCSEL p-electrode 9 is formed on the top of the contact layer 8 and n-electrode 10 is formed on the substrate 1 , to complete the “half VCSEL” structure. On the top of the half VCSEL structure, an independently manufactured upper mirror part is bonded to the half VCSEL structure. The independently manufactured upper mirror part is formed on a “handle” Si-substrate 11 that bonds the two layers together. A SiO 2 layer 12 is formed as an insulation layer, followed by a beam support layer of Si 13 . A thin membrane 14 is formed by etching the SiO 2 layer 12 as a sacrificial layer. An upper dielectric DBR 15 is deposited on one side of the membrane 14 , and an antireflection (AR) coating 16 is deposited on the opposite side. A MEMS electrode 17 and Au-bumps 18 are formed to supply the MEMS voltage, which can change the air gap between the contact layer 8 and the upper DBR 15 . An electric voltage source 19 is connected with the MEMS electrode 17 and with the p-electrode 9 . Therefore, the membrane 14 can be moved by the electrostatic force induced by the electric voltage source 19 , thereby changing the cavity length formed between the upper and bottom DBR mirrors, which in turn changes the lasing wavelength. An electric current source 20 is connected for current injection to the half VCSEL part.
Details of a device such as in FIG. 1 are described in T. Yano, H. Saitou, N. Kanbara, R. Noda, S. Tezuka, N. Fujimura, M. Ooyama, T. Watanabe, T. Hirata, and Nishiyama, “Wavelength modulation over 500 kHz of micromechanically tunable InP-based VCSELs with Si-MEMS technology”, IEEE J ., Selected Topics in Quantum Electronics, vol. 15, pp. 528-534, May/June 2009, incorporated herein by reference. VCSEL's with fixed lasing wavelengths of 1310 nm and 1550 nm, utilized in the prior art, are described in N. Nishiyama, C. Caneau, B. Hall, G. Guryanov, M. H. Hu, X. S. Liu, M.-J. Li, R. Bhat, and C. E. Zah, “Long-wavelength vertical-cavity surface-emitting lasers on InP with lattice matched AlGaInAs—InP DBR grown by MOCVD”, IEEE J ., Selected Topics in Quantum Electronics, vol. 11, pp. 990-998, September/October 2005, incorporated herein by reference.
In the prior art configuration of FIG. 1 , a tuning range of 55 nm at a center wavelength around 1550 nm has been shown. The maximum tuning range is limited by the reflectivity bandwidth of the bottom DBR, which is determined by the ratio of the refractive indices of high-index and low-index materials. The reflectivity bandwidths of a DBR composed of alternating layers of AlGaInAs (high-index material) and InP (low-index material) are approximately 50 nm and 70 nm for center wavelengths of 1310 nm and 1550 nm, respectively. However, SS-OCT requires over 100 nm tuning range. Therefore, the VCSEL employing a DBR composed of AlGaInAs and InP and an active layer comprising quantum wells is not suitable for OCT applications.
To overcome this tuning range limitation, a tunable VCSEL with MEMS has been suggested, that employs a bottom mirror consisting of a DBR composed of alternating layers of AlGaAs (high-index material) and Al x O y (low-index material) that has a reflectivity bandwidth over 200 nm centered near 1300 nm. This type of tunable VCSEL has achieved a tuning range over 100 nm by optical pumping. The details are described in V. Jayaraman, J. Jiang, H. Li, P. J. S. Heim, G. D. Cole, B. Potsaid, J. G. Fujimoto, and A. Cable, “OCT imaging up to 760 kHz axial scan rate using single-mode 1310 nm MEMS-tunable VCSEL with >100 nm tuning range”, CLEO: 2011—Laser Science to Photonic Applications, PDPB2, 2011, incorporated herein by reference. In this approach, the active region comprises InP based multiple quantum wells (MQWs) epitaxially grown on an InP substrate. The bottom DBR is epitaxially grown on a GaAs substrate. Therefore, the materials in the active region and the DBR part cannot be grown on a single type substrate. The two wafers must be bonded together, and then the InP substrate needs to be removed in order to form the half VCSEL part. Bonding the GaAs and InP wafers and the removing the InP wafer requires a very complicated process and introduces potential reliability issues.
Quantum dot (QD) lasers have been investigated with the aim of replacing conventional quantum-well lasers. QD lasers have unique characteristics such as ultra-low threshold currents and low temperature sensitivity due to the three-dimensional quantum size effect. Quantum dot technology has progressed significantly by the self-assembling growth technique of InAs QD's on large GaAs substrates. Application of QD's to conventional edge emitting lasers (as opposed to VCSEL systems) has been accomplished by replacing quantum wells of the active layer by QD's. The high performance of 1.3 μm QD Distributed Feedback (DFB) lasers has been reported recently. These lasers are fabricated by molecular beam epitaxy (MBE) of 8 stacks of a high density QD layer with p-doped GaAs layers on a p-type GaAs substrate. The gain spectrum has been measured: a maximum net modal gain as high as 42 cm −1 at around 1280 nm is obtained, and the 3 dB gain bandwidth is approximately 65 nm. The details are described in K. Takada, Y. Tanaka, T. Matsumoto, M. Ekawa, H. Z. Song, Y. Nakata, M. Yamaguchi, K. Nishi, T. Yamamoto, M. Sugawara, and Y. Arakawa, “10.3 Gb/s operation over a wide temperature range in 1.3 μm quantum-dot DFB lasers with high modal gain”, Optical Fiber Communication Conference\National Fiber Optic Engineers Conference, (2010), Technical Digest, incorporated herein by reference.
A 1.3 μm VCSEL comprising QD's for fixed wavelength applications has also been reported recently: On a GaAs substrate, a bottom DBR composed of 33.5 pairs of n + -doped AlGaAs layer and n + -doped GaAs layer, an undoped active region composed of InAs/InGaAs QD's, a p-doped AlGaAs oxidation layer, and a upper DBR composed of 22 pairs of p + -doped AlGaAs layers and p + -doped GaAs layers, are grown by MBE. The lasing wavelength is around 1279 nm at room temperature. A small linewidth enhancement factor of 0.48 has also been reported, which can provide a narrow linewidth that is critical for OCT applications. The details are described in P.-C. Peng, G. Lin, H.-C. Kuo, C. E. Yeh, J.-N. Liu, C.-T. Lin, J. Chen, S. Chi, J. Y. Chi, S.-C. Wang, “Dynamic characteristics and linewidth enhancement factor of quantum-dot vertical-cavity surface-emitting lasers”, IEEE J . Selected Topics in Quantum Electronics, vol. 15, pp. 844-849, May/June 2009, incorporated herein by reference.
The discussion of the background herein is included to explain the context of the technology. This is not to be taken as an admission that any of the material referred to was published, known, or part of the common general knowledge as at the priority date of any of the claims found appended hereto.
Throughout the description and claims of the specification the word “comprise” and variations thereof, such as “comprising” and “comprises”, is not intended to exclude other additives, components, integers or steps.
SUMMARY
The present invention includes a microelectromechanical system (MEMS) tunable vertical cavity surface-emitting laser (VCSEL) comprising one or more layers of quantum dots.
The present invention includes a novel MEMS tunable quantum dot-based VCSEL swept source design having a narrow dynamic line width with a wide tuning range, necessary for deeper tomographic imaging with higher axial resolution. The present invention provides a MEMS tunable quantum dot VCSEL that solves at least two problems in the prior art: (1) insufficient DBR reflectivity bandwidth of InP based DBR, and (2) complicated wafer bonding required for two different types of wafers, (as in, for example, an InP based active region wafer and a GaAs based DBR wafer). In the present invention, a GaAs based DBR with high reflection bandwidth and an active region of optical gain peak wavelength (including an exemplary embodiment centered around 1300 nm) can be epitaxially grown on a GaAs substrate, continuously without wafer bonding.
The MEMS tunable VCSEL includes an upper vertically movable mirror part and a bottom half VCSEL part. The upper mirror part includes: a membrane part supported by suspension beams, and an upper DBR provided on the membrane for reflecting light. The bottom half VCSEL part includes a bottom GaAs based DBR, an active region consisting of quantum dots which are epitaxially grown on top of the bottom DBR, and formed in a position facing the top DBR layer of the top mirror part via a gap. The cavity length of the cavity formed between the upper DBR and the bottom DBR can be changed by changing the gap distance through application of an electrostatic force to the membrane. Therefore, the lasing wavelength can be continuously changed with high speed. Since the VCSEL oscillates in a single mode, sample detection sensitivity is high in that the internal detectable depth is as deep as 50 mm in the SS-OCT system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a prior art MEMS tunable VCSEL;
FIG. 2 is a schematic representation of a MEMS tunable quantum dot VCSEL according to one exemplary embodiment of the present invention;
FIG. 3 is a schematic representation of a MEMS tunable quantum dot VCSEL according to a second exemplary embodiment of the present invention;
FIG. 4 a is a top view of an upper mirror part of a MEMS tunable VCSEL according to an embodiment of the present invention;
FIG. 4 b is a cross-section view along the A-A line of the upper mirror part in the embodiment of FIG. 4 a;
FIG. 5 is a schematic representation of a swept source optical coherence tomography system (SS-OCT) based on a MEMS tunable quantum dot VCSEL of the present invention;
FIG. 6 a is a schematic of a fiber based MEMS tunable quantum dot VCSEL swept source; and
FIG. 6 b is a schematic of a free space based MEMS tunable quantum dot VCSEL swept source.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
The technology of the present invention is exemplified by the two embodiments shown in FIGS. 2 and 3 , respectively. Each embodiment in FIGS. 2 and 3 comprises a pair of DBR's, one in the lower VCSEL half, and one in the upper MEMS portion. The two embodiments differ in the configuration of the upper (MEMS) half of each device. Both upper portions have the same overall function, and contain a membrane, an air gap and an upper (dielectric) DBR. The laser frequency is generated from a combination of the two DBR's and the air gap in between them.
FIG. 2 shows a schematic of an exemplary embodiment of the MEMS tunable quantum dot VCSEL of the present invention. On GaAs substrate 321 , a n-doped DBR 322 consisting of 30 to 40 pairs of alternating layers of GaAs 322 a , and AlGaAs 322 b lattice matched to GaAs, is epitaxially grown, followed by a n-doped GaAs cladding layer 323 . Then, an active layer 324 consisting of multi-layer stacks of InAs quantum dots (QD's) 324 a (for example, lateral size of about 20 nm and a height of about 5 nm) alternating with InGaAs barrier layers 324 b , are grown, followed by a p-doped AlGaAs cladding layer 325 . Other size quantum dots are acceptable, for example having an average diameter of 5-8 nm, though may be 10 nm in size or up to 30 nm. The dot density in each layer 324 a is typically in the range 10 10 -10 11 dots/cm 2 . This is expressed as a “surface area density”, since each layer typically supports only a single layer of dots. There are typically 8-20 layers per stack in the active layer, where each layer is up to about 40 nm thick, preferably 10-30 nm thick. Other numbers of layers are also consistent with the devices herein. The quantum dots are preferably made from InAs, though may be made from InGaAs, consistent with the operation of the overall technology. Quantum dots thereby provide different properties and functions in the active layer, when compared to the quantum wells previously used in the art. The quantum dots in the active layers may consist of dots of different sizes, as well as different compositions. In some embodiments, the quantum dots have a second quantized energy state (that is beneficial because it broadens the available spectrum to shorter wavelengths).
Above the cladding layer 325 , an AlGaAs oxidation layer 326 and a further p-doped AlGaAs cladding layer 325 a are grown. The oxidation layer 326 is partly oxidized except in a center region, referred to as aperture 326 a having a diameter of 3 to 8 μm, to which an injection current (from 325 a to the center region of 325 ) is confined ( 326 inhibits the current flow due to oxidation). On the top of cladding layer 325 a , a p-doped GaAs contact layer 327 is grown. VCSEL p-electrode 328 and n-electrode 329 (typically made of Ti, Pt, or Au and Cr, Ni, or Au respectively) are formed on the top of the contact layer 327 and the bottom of substrate 321 , respectively, to complete a half VCSEL structure.
After depositing an anti-reflection (AR) coating 51 on the GaAs contact layer 327 , the top half MEMS is formed by depositing a spacer layer 52 , composed of, for example, amorphous Ge, which is followed by a frame structure 53 , composed of, for example, silicon nitride (SiN x ). A membrane 54 is formed by etching the spacer layer 52 . In FIG. 2 , items 53 and 54 correspond to frame structure 332 , and to membrane 333 , respectively, in FIG. 4( a ). An upper dielectric DBR 55 , comprised of alternating layers of, for example, TiO 2 and SiO 2 , or Al 2 O 3 and a-Si (amorphous silicon), is deposited on one side of the membrane 54 . A MEMS electrode 56 is formed on frame structure 53 . An electric voltage source 57 is connected between the electrode 56 and the p-metal (typically Ti, Pt or Au) electrode 328 , to supply a MEMS voltage. Therefore, the membrane 54 can be deflected vertically by the electrostatic force induced by the voltage source 57 . This deflection can change the cavity length formed between the upper DBR 55 and the bottom DBR 322 , which changes the lasing wavelength. It is to be understood that where particular materials are specified for various layers and portions of the structure in FIG. 2 , other materials having equivalent functions and properties could be used in their place, according to considerations understood to those of skill in the art.
FIG. 3 shows a schematic of another exemplary embodiment of the MEMS tunable quantum dot VCSEL of the present invention. On GaAs substrate 321 , a n-doped DBR 322 consisting of 30 to 40 pairs of alternating layers of GaAs 322 a , and AlGaAs 322 b lattice matched to GaAs, is epitaxially grown, followed by a n-doped GaAs cladding layer 323 . Then, an active layer 324 consisting of multi-layer stacks of InAs quantum dots (QD's) 324 a (for example, lateral size of about 20 nm and a height of about 5 nm) alternating with InGaAs barrier layers 324 b are grown, followed by a p-doped AlGaAs cladding layer 325 . Above the cladding layer 325 , an AlGaAs oxidation layer 326 and a p-doped AlGaAs layer 325 a are grown. The oxidation layer 326 is partly oxidized except in a center region, referred to as aperture 326 a , having a diameter of 3˜8 μm, to which an injection current (from 325 a to the center region of 325 ) is confined. The oxidation layer 326 inhibits the current flow because the oxide is a poor conductor. On the top of the cladding layer 325 a , a p-doped GaAs contact layer 327 is grown, and thereafter an anti-reflection (AR) coating 336 is deposited on the GaAs contact layer 327 .
VCSEL p-electrode 328 and n-electrode 329 are formed on the top of the contact layer 327 and the bottom of substrate 321 , respectively, to complete a half VCSEL structure. To the extent thus far described, the structure of FIG. 3 is the same as that in FIG. 2 . In the embodiment of FIG. 3 , on the top of the half VCSEL structure, an independently manufactured top mirror part is bonded with a method such as thermo-compression The embodiment of FIG. 3 is therefore made differently from that of FIG. 2 : in FIG. 2 , the device can be manufactured from the bottom all the way up to the topmost layer (i.e., based on a single substrate). The device of FIG. 3 , by contrast, is made in two pieces. The bottom half of the VCSEL is deposited on the substrate, layer by layer, whereas the upper MEMS portion is made separately, and then attached to the bottom half.
FIG. 4 a is a top view of a vertically movable upper mirror part of a VCSEL according to the embodiment of FIG. 3 . FIG. 4 b is a cross-sectional view along the A-A line of FIG. 4 a . The portion shown in FIG. 4 b corresponds to the upper part of the device of FIG. 3 ; it is shown inverted relative to FIG. 3 in order to illustrate the manner in which it is made (by deposition of layers on to a substrate 330 that then becomes the top of the device). The movable upper mirror part is formed on a handle Si-substrate 330 , as follows. The MEMS part is made independently from the half VCSEL part, and bonded through the Au bumps 338 to the half VCSEL part. The Si-substrate 330 thereby functions like a kind of handle for bonding the two parts to one another. A SiO 2 layer 331 is formed as an insulation layer, followed by a frame structure 332 . A thin circular membrane 333 is formed, supported by four suspension beams 334 ( FIG. 4 a ), which are formed by etching the SiO 2 layer 331 as a sacrificial layer. An upper dielectric DBR 335 , comprised of alternating layers of, for example, TiO 2 and SiO 2 , or Al 2 O 3 and a-Si, is deposited on one side of the membrane 333 . As shown in FIG. 3 , a MEMS electrode 337 is formed on the substrate 330 , and gold (Au) bumps 338 are formed on membrane 333 . Typically, within the upper MEMS part, layers 331 , 332 / 333 and 338 are formed in sequence on the Si substrate 330 .
The upper mirror part (shown in FIG. 4 a ) is bonded to the p-electrode 328 via Au bumps 338 (with a method such as thermo-compression). An electric voltage source 339 is connected between the MEMS electrode 337 and the p-metal (typically Ti, Pt or Au) electrode 328 , to supply a MEMS voltage. Therefore, the membrane 333 can be deflected vertically by the electrostatic force induced by the voltage source 339 . This deflection can change the cavity length formed between the upper DBR 335 and the bottom DBR 322 , which thereby changes the lasing wavelength. An electric current source 340 is connected to provide current injection to the active region 324 . It is to be understood that where particular materials are specified for various layers and portions of the structures in FIGS. 3 , 4 a and 4 b , other materials having equivalent functions and properties could be used in their place, according to considerations understood to those of skill in the art.
FIG. 5 shows a schematic of a swept source optical coherence tomography system (SS-OCT) based on a MEMS tunable quantum dots VCSEL swept source utilizing a MEMS tunable quantum dot VCSEL such as shown in FIGS. 2 , and 3 , 4 a and 4 b . In this embodiment, the MEMS tunable quantum dots VCSEL swept source 100 has an optical output 209 that is then divided into two parts via fiber optic coupler 101 . One division of wave output is directed through a circulator 102 to a sample arm 103 . Another division from the fiber optic coupler 101 is directed through circulator 104 to reference arm 105 . Reflected wave from sample arm 103 and reference arm 105 are recombined through fiber optic coupler 106 , and the recombined wave is detected by balance detector 107 to give interference signal 112 . Wavelength monitoring/k-clock output 210 is divided in two parts through fiber optic coupler 108 and recombined through fiber optic coupler 109 that is detected by balance detector 110 to give k-clock signal 111 . A data acquisition card (DAQ) 113 is used to collect interference signal 112 and k-clock signal 111 , and a reconstructed depth profile is displayed through processing and display module 114 . Components such as couplers, balance detectors, and circulators, are typically off-the-shelf components that can be used with the technology described herein with little modification.
Regarding the MEMS tunable quantum dots VCSEL swept source 100 shown in FIG. 5 , there are two exemplary embodiments (fiber based and free space based). FIG. 6 a shows a schematic of an exemplary fiber based MEMS tunable quantum dots VCSEL swept source ( 100 a ). This embodiment comprises quantum dot tunable VCSEL 201 (such as one shown in FIG. 2 , or in FIGS. 3 , 4 a and 4 b ), isolator 202 , fiber optic coupler 203 , semiconductor optical amplifier (SOA) 206 , isolator 207 and fiber optic coupler 208 . Optical output 209 a and another output for wavelength monitoring/k-clock 210 a comes from fiber optic coupler 208 . An additional output from coupler 203 can be added for post amplification wavelength monitoring 205 , and a polarization control 204 can be used to maximize power after amplification through SOA 206 . Items 202 , 203 , 206 , 207 , 208 , 209 a , and 210 are off-the-shelf items that can be used without much modification.
FIG. 6 b shows a schematic of an exemplary free-space based MEMS tunable quantum dot VCSEL swept source of the present invention ( 100 b ) that produces optical output 209 b . This embodiment comprises a MEMS tunable quantum dot VCSEL 201 (such as one shown in FIG. 2 , or in FIGS. 3 , 4 a and 4 b ), isolator 211 , SOA 212 , isolator 213 , and a beam splitter 214 . In this embodiment, two outputs, optical output 215 b and wavelength monitoring/k-clock 210 b , are created by the beam splitter 214 . Items 211 , 212 , 213 , 214 , 215 b , and 210 b are off-the-shelf items that can be used without much modification.
Tunable Wavelength Range
The combination of a QD active region and a MEMS tunable DBR, as described herein and exemplified in FIGS. 2 and 3 , has not previously been reported. The tunable wavelength range of the swept source from such a combination is preferably greater than 100 nm. Typically, the tunable wavelength range of a single swept source is from 100-200 nm, i.e., may be up to 110 nm, up to 120 nm, up to 150 nm, up to 180 nm. Variations are achieved by altering, for example, the compositions of the quantum dots, or by using combinations of quantum dots of different compositions. The tunable range is typically centered on one of three or four different bands, including but not limited to center wavelengths from 250-1950 nm for example at: 850 nm; 1,050 nm (sometimes loosely referred to as “1 micron”); 1,300 nm; 1,500; and 1,700 nm. The relevant applications of different center wavelengths depend on the tissue or other material that is being analyzed by the laser light produced by the device. The present invention is able to achieve the stated tuning range, as explained hereinbelow.
The peak wavelength of the optical gain of a QD is determined by the size and shape of the QD and its composition, as well as the barriers surrounding the QD. Although the shape of a real QD is not a rectangular solid, the gain peak wavelength for a QD formed with size a×b×c along the x-, y- and z-directions respectively, can be calculated relatively straightforwardly as follows: the emission wavelength corresponding to the transition between the quantized energy levels of the conduction and valence bands with the same quantization number is given by equation (1):
λ(μm)=1.24/( E g +E c mnl +E v m′n′l′ )(eV) (1)
where E c mnl and E v m′n′l′ are quantized energy levels in the conduction and valence band of the QD, respectively. The gain peak wavelength is a little shorter than the emission wavelength given by equation (1) due to the carrier related broadening effect. If an infinite barrier potential for the QD is assumed for the sake of simplicity, E c mnl and E v m′n′l′ can be expressed analytically as:
E c lmn = E c 0 + ℏ 2 2 m e * [ ( l π a ) 2 + ( m π b ) 2 + ( n π c ) 2 ] ( 2 ) E v l ′ m ′ n ′ = E v 0 - ℏ 2 2 m h * [ ( l ′ π a ) 2 + ( m ′ π b ) 2 + ( n ′ π c ) 2 ] ( 3 )
where E c0 is the conduction-band edge energy, E v0 is the valence band edge energy, m* e and m* h are the effective mass of the electrons and the holes, respectively, ℏ is “h-bar” (the Planck constant h divided by 2π). Integers l, m, and n are quantum numbers that denote the labels of the quantized energy levels. The lowest energy level corresponds to l=m=n=1 (or l′=m′=n′=1). The gain peak appears around the quantized energy level. Therefore, the gain peak wavelength is determined by the dot size, and the dimensions a, b and c. In this way, the gain peak wavelength can be changed by changing the size of a QD. A QD with larger size has a second quantized state (either of l, m, or n (or l′, m′, n′) is larger than 1) with higher energy that has a gain peak at shorter wavelength side. These two gain peaks make a broad gain spectrum.
The detail of the gain spectrum of QD's is described in (S. L. Chuang, Physics of Photonic Devices , John Wiley & Sons 2009, pp. 376-381, incorporated herein by reference). As noted in equations (1) and (2), the energy levels are also determined by the effective masses m* e and m* h of the carriers, and the band edge energies E c0 and E v0 , which are related to the compositions of the QD's and the respective barriers. The size and shape of QD's in each QD layer can be adjusted by varying crystal growth condition and composition selection: therefore, the gain peak wavelength can have a distribution which will produce a broader gain spectrum. A gain bandwidth of 65 nm has been reported in the publication Takada, et al., “10.3 Gb/s operation over a wide temperature range in 1.3 μm quantum-dot DFB lasers with high modal gain”, Optical Fiber Communication Conference\National Fiber Optic Engineers Conference, Technical Digest (2010), incorporated herein by reference.
In other work, the gain bandwidth of QD's can further be broadened by combining QD's and a quantum well (QW): the quantized energy level of the QW is chosen to be higher than the second quantized energy level of the QD, providing another gain peak to broaden the gain bandwidth. Using this method, a total gain bandwidth of more than 200 nm has been achieved. In this work, a gain bandwidth of 160 nm from QD's alone was shown. The detail is described in (S. Chen, K. Zhou, Z. Zhang, J. R. Orchard, D. T. D. Childs, M. Hugues, O. Wada, and R. A. Hogg, “Hybrid quantum well/quantum dot structure for broad spectral bandwidth emitters”, IEEE J . Selected Topics of Quantum Electron., vol. 19, No. 4, July/August 2013, incorporated herein by reference). But the structures described in the two references cited in this and the preceding paragraph are not sufficient to achieve the lasing wavelength tuning of a widely tunable laser or a swept source.
As explained hereinabove, the present invention provides a MEMS tunable quantum dot VCSEL (with an exemplary embodiment emitting a center wavelength around 1,300 nm). This present invention at solves at least two problems in the prior art. First, the problem of insufficient DBR reflectivity bandwidth of InP based DBR's in the prior art is solved by using a GaAs based DBR with broader reflectivity bandwidth. Second, the problem of a complicated wafer bonding process that was believe to be necessary in the prior art to bond an InP based active region wafer to a GaAs based DBR wafer, is obviated by using a quantum dot active region continuously grown on top of a GaAs based DBR, which is grown on a GaAs substrate.
All references cited herein are incorporated by reference in their entireties.
The foregoing description is intended to illustrate various aspects of the instant technology. It is not intended that the examples presented herein limit the scope of the appended claims. The invention now being fully described, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the appended claims.
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A wavelength-tunable vertical-cavity surface-emitting laser (VCSEL) with the use of microelectromechanical system (MEMS) technology is provided as a swept source for Optical Coherence Tomography (OCT). The wavelength-tunable VCSEL comprises a bottom mirror of the VCSEL, an active region, and a MEMS tunable upper mirror movable by electrostatic deflections. The bottom mirror comprising a GaAs based distributed Bragg reflector (DBR) stack, and the active region comprising multiple stacks of GaAs based quantum dot (QD) layers, are epitaxially grown on a GaAs substrate. The MEMS tunable upper mirror includes a membrane part supported by suspension beams, and an upper mirror comprising a dielectric DBR stack. The MEMS tunable quantum dots VCSEL can cover an operating wavelength range of more than 100 nm, preferably with a center wavelength between 250 and 1950 nm, and the sweeping rate can be from a few kHz to hundreds of kHz, and up to a few MHz.
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This application claim the benefit of provisional application Ser. No. 60/203,034, filed May. 9, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to brassieres. More particularly, the present invention relates to a brassiere having underwire support, yet permits natural shaping and flexibility.
2. Description of the Prior Art
To be comfortable, a brassiere must combine both support for the wearer's breasts and freedom of movement for the wearer's body.
In order to give freedom of movement to the wearer, some brassieres include a high percentage of stretchable materials, such as elastic. However, brassieres formed primarily of stretchable fabric may not provide sufficient breast support.
To achieve a suitable level of support for the breast, brassieres use support underwires and/or nonstretchable fabric in certain areas. However, support underwires, especially when secured in place by nonstretchable material, can become an impediment to an active wearer. Moreover, support underwires, especially during movement by an active wearer, may poke through the fabric of the brassiere.
There are brassieres that attempt to combine support and freedom of movement. For example, some brassieres place the underwires in an inner panel next to the skin, so that the underwires are spaced apart from the material forming the breast cups. However, this configuration increases the complexity of the brassiere, and may do little to overcome the dual problem of achieving flexibility and support.
Giving the foregoing, there is a need for a brassiere that provides freedom of movement without discomfort, as well as support for the breasts, during all activities of the wearer.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a brassiere that provides freedom of movement without affecting adversely the brassiere's ability to support the wearer's breast.
It is also an object of the present invention to provide such a brassiere that has a partially floating underwire.
It is another object of the present invention to provide such a brassiere that has stretchable panels.
It is yet another object of the present invention to provide such a brassiere that has a stretchable underwire sheath.
It is a further object of the present invention to provide such a brassiere that has underwires with an anatomically desired shape thereby enhancing support, natural shaping and comfort on the body.
These and other objects of the present invention are achieved by a brassiere that includes a body having a pair of breast cups, a pair of panels each adjacent to a separate breast cup and connected to a back of the brassiere, and a pair of stretchable sheaths secured along a lower portion of the breast cup and floating along the side panel of the brassiere. Each side panel is made of a stretchable material. The brassiere further includes a pair of underwires, each positionable in one of said pair of sheaths. In a preferred embodiment, the panels stretch only in the sideways or horizontal direction. Since the sheath is not attached to the body of the brassiere along the side panel, it floats thereby providing greater flexibility. In a first embodiment, the panel one panel that extends to the back of the brassiere. In a second embodiment, the panel is a side panel that is connected to one or more other panels, one of which extends to the back of the brassiere. Preferably, in any embodiment, the underwire is anatomically shaped so that the curve of the underwire is greater on the inner portion compared to the outer portion thus providing enhanced support at all times.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a brassiere according to the present invention;
FIG. 2 is a portion of the exterior of the brassiere of FIG. 1;
FIG. 3 is a portion of the interior of the brassiere of FIG. 1;
FIG. 4 is a cross-sectional view taken along line 4 — 4 of FIG. 3; and
FIG. 5 is a cross-sectional view taken along line 5 — 5 of FIG. 3 .
FIG. 6 is an alternative embodiment of a portion of the interior of the brassiere of FIG. 1 ;
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings and, in particular, FIG. 1, there is provided a brassiere according to the present invention, generally represented by reference numeral 10 . Brassiere 10 has a body with a pair of breast cups 12 , a pair of side panels 30 connected to the pair of breast cups, and a pair of back straps or panels 50 connected to the pair of side panels, and a pair of support panels 60 connected to the pair of breast cups 12 and a body encircling band 65 .
As shown in FIGS. 2 and 3, each breast cup 12 has an inner edge 14 , an outer or back edge 16 , an upper edge 18 and a bottom edge 20 . Each outer edge 16 is connected to one side panel 30 . In addition, the bottom edge 20 of each breast cup 12 is connected to a support panel 60 .
Each side panel 30 at an outer or back edge 36 thereof is preferably connected to one back panel 50 . The back panels 50 encircle the remainder of the torso of the wearer and are joined together by conventional fasteners 54 , such as, for example, hook-and-eye closures.
In an alternative embodiment of the present invention, brassiere 10 may encircle the torso of the wearer and breast cups 12 may be joined together by a front closure utilizing conventional fasteners.
As illustrated in FIG. 1, brassiere 10 preferably has a pair of adjustable shoulder straps 70 that connect to upper edges 18 of breast cups 12 and back panels 50 .
As used herein the terms “sideways,” “vertical,” and “horizontal” are defined in reference to the orientation of brassiere 10 as it would be positioned on a wearer's body and, thus, shown in FIG. 1 . Thus, back panels 50 extend substantially sideways or horizontally, while shoulder straps 70 extend substantially vertically.
Again referring to FIGS. 2 and 3, side panel 30 is a panel, preferably having a triangular shape, disposed between breast cup 12 and back panel 50 . Side panel 30 is made of a stretchable or elastic type material. Side panel 30 may be made of any suitably stretchable material that is adapted to stretch primarily, and preferably only, in the sideways or horizontal direction. Thus, each side panel 30 provides one-way stretch. Accordingly, side panel 30 is substantially inflexible in the vertical direction. Preferably, side panel 30 is made of a stretch woven or elastomeric fabric.
FIG. 3 illustrates the inside of brassiere 10 . Underlying breast cup 12 and side panel 30 is sheath or wire channeling 80 . Sheath or wire channeling 80 is adapted to receive underwire 90 . Sheath or wire channeling 80 has a first portion 82 that is positioned along the lower portion of breast cup 12 and a second portion 84 that is positioned angularly in breast cup 12 and side panel 30 . Sheath or wire channeling 80 , namely first portion 82 and second portion 84 is adapted to accommodate underwire 90 . First portion 82 is connected to breast cup 12 . Preferably, first portion 82 is connected just up to outer edge 16 . Alternatively, but less preferably, first portion 82 may be connected to an inner lining (not shown) that is separated from breast cup 12 or partially integrated with the breast cup.
In an alternative embodiment of the invention, shown in FIG. 6, side panel 30 and back panel 50 of FIG. 1, are made as one integral panel 30 ′. Panel 30 ′ is made from one piece of stretchable or elastic type material. The function of panel 30 ′ remains the same as side panel 30 of FIG. 1 in that it provides one-way, horizontal stretch at the area of each breast cup 12 .
Referring to FIG. 4, second portion 84 of sheath or wire channeling 80 is not attached to side panel 30 (or panel 30 ′ of the embodiment shown in FIG. 6 ). Instead, the distal end of second portion 84 is connected to underarm edge 95 . Thus, second portion 84 “floats” along side panel 30 between underarm edge 95 to the side of outer edge 16 in breast cup 12 , while first portion 82 is secured to support panel 60 or breast cup 12 .
Sheath or wire channeling 80 is made of a stretchable material. Accordingly, sheath or wire channeling 80 stretches as shown by arrows A seen in FIGS. 3 and 6. As shown in FIG. 5, sheath or wire channeling 80 is preferably made of two plies. Such a two ply structure has been found to avoid underwire poke through and to provide more comfort to the wearer. The inner ply is a biased cut cushioning fabric layer 86 . The outer ply is a covering fabric layer 88 .
Cushioning fabric layer 86 may be made of cotton batting, polyester non-woven, or other suitable padding material. Preferably, cushioning fabric layer 86 is a one hundred percent polyester non-woven material. A preferred one hundred percent polyester non-woven material is manufactured by Tietex Corporation U.S.A. and sold under the tradename T316. Covering fabric layer 88 is wrapped over cushioning fabric layer 86 . Covering fabric layer 88 is preferably made of stretchable material, such as elastomeric, or stretch woven, material that is the same as side panel 30 .
In one embodiment, side panel 30 or panel 30 ′ is made of a three bar knit. The elastomeric, or stretch woven, fabric may be made of varying combinations of cotton or polyester or nylon and spandex. This elastomeric material may contain from 5% to 35% spandex, and the remainder is nylon or cotton or polyester or any combinations thereof.
Preferably, covering fabric layer 88 is a three bar knit, with a ratio of about 77% nylon to about 23% spandex.
The combined stretchability of side panel 30 (or panel 30 ′) and floating second portion 84 creates greater freedom of movement for the wearer.
Underwire 90 is made of any material that provides support. For example, underwire 90 can be made of rigid plastic or metal. In addition, the gauge of underwire 90 preferably does not vary from one end to the other.
Preferably, underwire 90 is asymmetrically shaped as shown clearly in FIGS. 2 and 3. Underwire 90 has a first or inner portion 92 that is positioned in first portion 82 of sheath, or wire channeling, 80 and follows a first angle a. Underwire 90 also has a second or outer portion 94 that is positioned in second portion 84 of sheath or wire channeling 80 and follows a second angle θ. Preferably, first angle a is greater than second angle θ. Thus, first portion 92 has a greater curve compared to second portion 94 . When shaped accordingly, underwire 90 mirrors the shape of a woman's breast. Therefore, underwire 90 provides better support and enhanced comfort to the wearer.
It is preferable that first angle α equals about 55° to about 70° and, more preferably, about 63°. In comparison, it is preferable that second angle θ equals about 50° to about 65° and, more preferably, about 57°. The difference between first angle a and second angle θ is preferably about 1 to about 10 degrees and, more preferably, about 5 degrees.
The present invention having been described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.
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There is provided a brassiere that includes a body having a pair of breast cups, a pair of stretchable panels each adjacent a separate breast cup and connected to a back of the brassiere, and a pair of stretchable sheaths secured along a lower portion of the breast cup and floating along the panel of the brassiere. Each panel is made of a stretchable material. The brassiere further includes a pair of underwires each positionable in one sheath. Preferably, the underwire is anatomically shaped so that the curve of the underwire is greater on the inner portion compared to the outer portion.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 09/897,401, filed Jul. 3, 2001 now U.S. Pat. No. 6,665,147, which claims priority from Japanese Patent Application No. 2000-208228, filed Jul. 5, 2000. This application is related to and claims priority from Japanese Patent Application No. 2002-12291, filed Jan. 22, 2002. The entire disclosures of these applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a hard disk drive that uses a magnetic recording medium in which at least a magnetic layer and a protective layer are formed on a magnetic disk substrate, and a liquid lubricating agent with a perfluoroether structure is applied to the surface thereof. The present invention also relates to a hard disk drive with a mechanism for supplying a lubricating agent into the device in the form of a gas.
The recording densities in hard disk drives has been steadily increasing at a significant rate. Recently, recording densities of 20 gigabits per square inch (Gbit/inch 2 ) have been announced. A requirement for achieving these high densities is to reduce the distance between the magnetic head and the magnetic recording layer of the magnetic disk as much as possible. Currently, this distance must be no more than 20 nm.
To reduce this distance as much as possible, the surface roughness of the magnetic disk must be reduced as much as possible. Therefore, there has been a transition from the contact start/stop (CSS) systems, where the magnetic head is in contact with the magnetic disk when the disk is not spinning and the magnetic head flies up due to air currents when the magnetic disk begins spinning, to load/unload (U/UL) systems, where the magnetic head is retracted away from the magnetic disk (unloaded) when the disk is stopped and is loaded on to the magnetic disk when the magnetic disk begins spinning. In U/UL systems, anti-sliding characteristics can be relaxed somewhat. However, the hard disk drive must be able to withstand impacts from load-on operations as well as sudden irregularities in head orientation that can occur even in normal operations.
Improvements in the protective layer and lubricating layer on magnetic disks are being made in order to minimize frication and damage caused by contact between the head and the magnetic disk. For example, in Japanese laid-open patent publication number Hei 8-319491, a perfluoro polyether with a phosphazene ring group is used in a lubricating agent to improve its properties. In Japanese laid-open patent publication number Hei 10-143836, a polyphenoxy cyclotriphosphazene is mixed with a perfluoro polyether at a weight ratio of 0.01-1. In Japanese laid-open patent publication number 2001-187796, a lubricating agent contains at least 30% perfluoro polyether having a phosophezene ring group. The object of these technologies is to improve wear resistance in magnetic disks, reduce head debris, reduce friction, reduce decomposition of the lubricating agent, or the like.
With regard to decomposition of the lubricating agent, it is believed that hydrogen fluoride (HF) is generated due to thermal decomposition from friction heat or decomposition due to Lewis acid, and that this HF causes a chain reaction that leads to decomposition of the lubricating agent. Japanese laid-open patent publication number Hei 10-143839 states that lubricating agents decompose due to exoelectrons generated by friction between the magnetic head and the magnetic disk.
Lubricating agents are supplied so that splattering of the lubricating agent due to rotation and heat can be reduced. In conventional technologies that supply lubricating agents to hard disk drives in the form of a gas, the lubricating agent supply source is placed within the head disk assembly. This conventional technology did not take into account the material and absorption properties of the supplied lubricating agent, the material and absorption properties of the lubricating layer formed on the magnetic disk, and the combinations of these elements. As a result, some lubricating agents are not able to prevent debris on the magnetic head, thus leading to reduced reliability. Furthermore, with some lubricating agents, corrosive outgas in the hard disk drive could generate a deposit on the magnetic head element that corrodes the metal in the element.
Also, absorption properties of the lubricating agent can vary depending on the type and characteristics of the protective layer of the magnetic disk. With diamond-like carbon (DLC) layers in particular, the absorption of the lubricating agent is less than that of carbon layers formed by sputtering, making it difficult to support the supplied lubricating agent on the magnetic disk and leading to reduced wear prevention.
SUMMARY OF THE INVENTION
When mixing two types of lubricating agents, e.g., a lubricating agent containing phosphazene and another lubricating agent, the combination must at least be evaluated based on compatibility, head debris, friction, and the like.
Magnetic heads used in magnetic disks are generally formed from a reproducing element that uses the Magneto-Resistive effect and a magnetic induction recording element. The recording element is formed from a coil generating a magnetic field and a magnetic pole that induces the magnetic field. The recording element records signals by sending a current of approximately a few dozen mA to the coil. The reproducing element receives a bias current. The reproducing element plays back signals by detecting changes in resistance resulting from the magnetic field. This bias current is between a few and a few dozen mA. Recording and reproducing frequencies increase with the recording density. With a 3.5 inch hard disk drive having a recording density of 20 Gbit/inch 2 , the frequency reaches approximately 300 MHz. When recording at such high frequencies, the recording element generates heat due to electrical resistance and impedance resistance, becoming very hot. The heat that is generated depends on the element structure, but can reach 200-250 degrees Centigrade. Heat generation increases when the recording frequency increases. The reproducing element also generates heat in a similar manner. The layer thickness of the reproducing element is on the order of submicrons, and the track width decreases as the recording density increases. As a result, heat generation increases with higher recording densities.
Friction heat causes the lubricating agent of a magnetic disk to decompose. However, it has not been clearly pointed out that heat from the recording or reproducing element in the head leads to the decomposition of the lubricating agent on the slider surface near the recording/reproducing element of the head, resulting in reduced reliability in the hard disk drive. We have studied the causes of reduced reliability in hard disk drives and have discovered that reduced reliability is caused by decomposition and transfer of the lubricating agent due to heat from the recording and reproducing elements in the head.
This will be described in more detail. Lubricating agent adhered to the slider surface near the recording and reproducing elements is decomposed by heat from the recording or reproducing element. This creates hydrogen fluoride (HF), causing lubricating agent with a higher concentration of HF to be adhered to the magnetic disk surface. The lubricating agent adhered to the magnetic disk surface corrodes the magnetic layer and the like of the magnetic disk. As a result, a protrusion formed on the magnetic disk surface, which undergoes volume expansion due to this corrosion, is adhered. The magnetic disk surface forming the protrusion comes into contact with the magnetic head, leading to wear on the protective layer, the magnetic layer, and the like. In the worst case, this can lead to loss of data recorded on the magnetic layer, resulting in secondary errors in which data recorded on the magnetic layer is erased.
The present invention provides a hard disk drive that overcomes the loss of reliability in hard disk drives caused by these secondary errors.
More specifically, the present invention provides a hard disk drive including: a magnetic disk to which is applied a first lubricating agent formed as:
(where p=0 or an integer of at least 1, q=0 or an integer of at least 1, and X=1-5); a spindle motor spinning the magnetic disk; a magnetic head reading information recorded on the magnetic disk; an arm supporting the magnetic head; a voice coil motor positioning the arm on the magnetic disk; a circuit processing a signal read by the magnetic head; and a mechanism for supplying a second lubricating agent formed as:
HOCH 2 CF 2 (OC 2 F 4 ) p (OCF 2 ) q OCF 2 CH 2 OH
(where p=0 or an integer of at least 1 and q=0 or an integer of at least 1) into the device.
According to another aspect, the present invention provides a hard disk drive including: a magnetic disk to which is applied a first lubricating agent formed as:
(where p=0 or an integer of at least 1, q=0 or an integer of at least 1, and X=1-5), and over which is applied a second lubricating agent formed as:
HOCH 2 CF 2 (OC 2 F 4 ) p (OCF 2 ) q OCF 2 CH 2 OH
(where p=0 or an integer of at least 1 and q=0 or an integer of at least 1) into the device; a spindle motor spinning the magnetic disk; a magnetic head reading information recorded on the magnetic disk; an arm supporting the magnetic head; a voice coil motor positioning the arm on the magnetic disk; and a circuit processing a signal read by the magnetic head.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified drawing showing a cross-section structure of a magnetic disk according to embodiment 1.
FIG. 2 is a simplified drawing of a structure of a magnetic disk.
FIG. 3 is a drawing comparing numbers of secondary errors as they relate to following time in embodiments 1, 2 and comparative example 1.
FIG. 4 is a drawing comparing lubricating layer thicknesses before and after a test in embodiments 1, 2 and comparative example 1.
FIG. 5 is a drawing comparing the number of secondary errors as they relate to following time in embodiment 3 and comparative example 2.
FIG. 6 is a drawing showing how the number of secondary errors depends on molecular weight.
FIG. 7 is a drawing comparing lubricating layer thicknesses before and after a test in embodiment 4 and comparative example 3.
FIG. 8 is a drawing showing the relationship between the proportion of chemical formula (1) and secondary errors.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An example of the advantages of the present invention will be described using an embodiment. A glass substrate marketed for magnetic disks is suitable as a non-magnetic magnetic disk substrate. In order to reflect the surface roughness of a substrate surface, a magnetic disk medium which surface roughness (Ra) was approximately 0.8 nm, was prepared.
<Embodiment 1>
FIG. 1 is a simplified drawing of the layer structure of a magnetic disk according to embodiment 1. After washing a glass substrate 1 , a disk sputtering device (Intevac Corp.'s MDP-250) is used to form a seed layer 2 , a base layer 3 , a lower magnetic layer 4 , a non-magnetic intermediate layer 5 , an upper magnetic layer 6 , and a protective layer 7 , as shown in the figure. The seed layer 2 is sputtered using a NiTa alloy target to form a layer that is approximately 30 nm thick. The thickness of the seed layer was measured using X-ray spectrometry. After it is formed, the seed layer is heated at approximately 260 degrees Centigrade and exposed for approximately 3.5 seconds to an Ar—O 2 gas. The CrTi alloy base layer 3 is formed over the seed layer 2 with a thickness of approximately 5 nm. The base magnetic layer is formed as a CoCrPt alloy magnetic layer with a thickness of approximately 3.5 nm. The intermediate layer is formed Ru layer with a thickness of approximately 0.5 nm. The upper magnetic layer 6 is formed as a CoCrPtB alloy layer with a thickness of approximately 15 nm. The protective layer 7 is formed with a thickness of approximately 3.5 nm over the upper magnetic layer 6 . An example of this protective layer 7 is a DLC (diamond-like carbon) layer formed using CVD (chemical vapor deposition) or IBD (ion beam deposition). The thickness of the protective layer 7 is measured using X-ray reflection. To improve accuracy in the thickness measurement, quantizing is done by forming a 5 nm Cr layer over the protective layer 7 . The X-ray reflection quantization of layer thickness was performed using Rigaku Denki Kogyo Corp.'s SLX2000TM with an [CuK alpha1 ] X-ray. Using Sumitomo-3M Corp.'s HFT7100 as a solvent, a lubricating agent solution as shown in chemical formula (1) was created. The magnetic disk was dipped into this lubricating agent solution to form the lubricating layer 8 . The perfluoro polyether backbone chain in the lubricating agent based on chemical formula (1) has a number-average molecular weight of approximately 2,000. An FTIR measurement of the lubricating layer showed a thickness of approximately 1.5 nm.
(where p=0 or an integer of 1 or more, q=0 or an integer of 1 or more, X=1-5.)
<Embodiment 2>
A magnetic disk was created in a manner similar to that used in embodiment 1. However, a lubricating agent as shown in chemical formula (2) was used. The perfluoro polyether backbone chain in the lubricating agent based on chemical formula (2) has a number-average molecular weight of approximately 2,000. An FTIR measurement of the lubricating layer showed a thickness of approximately 1.5 nm.
COMPARATIVE EXAMPLE 1
A magnetic disk was created in a manner similar to that used in embodiment 1. However, a lubricating agent as shown in chemical formula (3) was used. Five types of lubricating agents were used, with number-average molecular weights of 1,000, 2,000, 3,000, 4,000, and 6,000, as measured using NMR (nuclear magnetic resonance). FTIR measurements of the lubricating layer thicknesses showed that each had a thickness of approximately 1.5 nm.
HOCH 2 CF 2 (OC 2 F 4 ) p (OCF 2 ) q OCF 2 CH 2 OH Chemical Formula (3)
(where p=0 or an integer of 1 or more and q=0 or an integer of 1 or more.)
The magnetic disks from embodiment 1, embodiment 2, and comparative example 1 were installed in a 3.5 inch hard disk drive (magnetic disk device). A simplified drawing of the hard disk drive is shown in FIG. 2 .
The disk device includes: a spindle motor 10 for spinning a magnetic disk 9 ; an arm 12 for supporting a magnetic head 11 used to record information to the magnetic disk 9 and/or to read information recorded on the magnetic disk 9 ; a voice coil motor 13 for aligning the arm 12 ; a circuit 14 for processing information recorded on the magnetic disk 9 and read by the magnetic head 11 and information to be written to the magnetic disk 9 ; a mechanism for supplying the lubricating agent to the device (in this case, a dust filter 15 ); and the like. An approximately 1.0 mg drop of the lubricating agent indicated by chemical formula (3) and having a number-average molecular weight of 2,000 was applied to the dust filter 15 , which was placed at a predetermined position to supply the lubricating agent to the device. The magnetic disks from the embodiments and the comparative examples were installed. The hard disk drive was operated at a speed of approximately 10,000 rpm (rotations per minute), with a recording density of approximately 20 Gbit/inch 2 , a head flying height of approximately 15 nm, and a test environment temperature of approximately 50 degrees Centigrade.
The heads of the hard disk drive was fixed at a radial position of 38 mm so that they continuously followed a fixed recording track. The number of secondary errors was monitored, and the results are shown in FIG. 3 .
As shown in FIG. 3, there were no secondary errors in embodiment 1 and embodiment 2. Thus, secondary errors were reduced and reliability was improved by applying perfluoro polyether lubricating agents having the molecular structures shown in chemical formula (1) and (2) to magnetic disks and using a hard disk drive equipped with a mechanism for supplying a lubricating agent shown in chemical formula (3) with a number-average molecular weight of 2,000. With comparative example 1, however, the number of secondary errors increased over time. As a result, it was found that secondary errors took place and the number increased over time when the same lubricating agent as shown in chemical formula (3) was applied to a magnetic disk.
This hard disk drive was taken apart after it was operated for 465 hours, and FTIR measurements were made of the lubricating layer thicknesses on the installed magnetic disks. FIG. 4 shows the changes in lubricating layer thickness before and after the test.
For example, the lubricating layer thickness of the magnetic disk from embodiment 1 was initially approximately 1.5 nm but increased to approximately 1.8 nm after the test. This indicates that the lubricating agent indicated by chemical formula (3) that was applied to the dust filter 15 adhered to the magnetic disk and increased the thickness. From this result, it can be postulated that the lubricating layer on the magnetic disk consists of approximately 1.5 nm of the lubricating agent indicated by the chemical formula (1) and approximately 0.3 nm of the lubricating agent indicated by the chemical formula (3). In this case, the lubricating agent from the chemical formula (1) would make up approximately 83% of the entire lubricating layer. The values shown in FIG. 4 show the proportions of lubricating agents on the magnetic disks before the test. After the test, the lubricating agent proportion was approximately 70-90% compared to before the test for embodiment 1, embodiment 2, and comparative example 1. These results show that the frequency of secondary errors can be reduced by forming the lubricating layer on the magnetic disk ahead of time as a mixture of the lubricating agents shown in chemical formula (1) and (2) and the lubricating agent shown in chemical formula (3) with a number-average molecular weight of 2,000, and by setting the proportion of the mixture to be the same as that of the lubricating layer after the test.
<Embodiment 3>
A magnetic disk was produced in the same manner as embodiment 2. An FTIR measurement showed that the lubricating layer had a thickness of approximately 1.5 nm. A drop of approximately 1.0 mg of lubricating agent as shown in chemical formula (3) with a number-average molecular weight of 1,000 was applied to the dust filter 15 , which was placed at a predetermined position in a 3.5 inch hard disk drive. In another 3.5 inch hard disk drive, a drop of 1.0 mg of the lubricating agent with a number-average molecular weight of 1,000 was applied to the dust filter 15 placed at a predetermined position. The magnetic disk from embodiment 3 was installed in the hard disk drives. A test was conducted in a manner similar to those for embodiment 1 and 2.
COMPARATIVE EXAMPLE 2
A magnetic disk was created in a manner similar to that used in embodiment 3. However, a lubricating agent as shown in chemical formula (3) was used. Three types of lubricating agents were used, with number-average molecular weights of 3,000, 4,000, and 6,000, and 1.0 mg drops were applied to the dust filters 15 placed at predetermined positions in three hard disk drives, and the disks from the comparative example 2 were installed in these devices. A test was conducted in a manner similar to those for embodiment 1 and 2.
FIG. 5 shows test results for the embodiment 3 and the comparative example 2.
These test results show that the frequency of secondary errors increases significantly as the molecular weight of the lubricating agent increases. FIG. 6 shows the results illustrated using the molecular weights of the lubricating agents as a parameter.
As FIG. 6 shows, secondary errors are less frequent with lower molecular weights. In particular, almost no secondary errors take place at molecular weights of 2,400 and less. Since a molecular weight that is too low can impede the function of the lubricating agent, e.g., because there is too much evaporation, so an average molecular weight of at least approximately 600 is preferable. Based on the test results for embodiments 1, 2, 3 and comparative examples 1, 2, a highly reliable hard disk drive can be achieved by supplying the hard disk drive with a lubricating agent as shown in chemical formula (3) and with a number-average molecular weights of at least approximately 600 and no more than approximately 2,400 and by forming the lubricating layer on the magnetic disks with a lubricating agent as shown in chemical formula (1) or chemical formula (2).
Next, the lubricating layer thickness of the hard disk drives from the embodiment 3 was measured after the test. It was found that the magnetic disk installed in the hard disk drive with the lubricating agent having a number-average molecular weight of 1,000 had a layer thickness of approximately 1.75 nm. The magnetic disk installed in the hard disk drive with the number-average molecular weight of 2,000 had a layer thickness of approximately 1.86 nm. As a result, it was determined that the proportions of the lubricating agent shown in chemical formula (2) were approximately 86% and 81% respectively. Thus, it is believed that few secondary errors take place in magnetic disks with lubricating layers formed by mixing a lubricating agent from chemical formula (1) or (2) with a lubricating agent from chemical formula (3) with a number-average molecular weight of approximately 600-2,400.
<Embodiment 4>
Magnetic disks were made in a manner similar to that of embodiment 2. However, the lubricating layer thicknesses were set to 1.0, 1.2, 1.5, and 1.8 nm.
<Comparative Embodiment 3>
Magnetic disks were made in a manner similar to that of embodiment 2. However, the lubricating layer thicknesses were set to 0.4, 0.6, and 0.8 nm.
Two types of 3.5-type hard disk drives were prepared, one in which a 1.0 mg drop of lubricating agent as shown in chemical formula (3) with a number-average molecular weight of 1,000 was applied to the dust filter 15 placed at a predetermined position in the device, the other in which a 1.0 mg drop of lubricating agent as shown in chemical formula (3) with a number-average molecular weight of 2,000 was applied to the dust filter 15 placed at a predetermined position in the device. The magnetic disks from the embodiment 4 and the comparative example 3 were installed in these hard disk drives. The hard disk drive was operated at a speed of approximately 10,000 rpm, with a recording density of approximately 20 Gbit/inch 2 , a head flying height of approximately 15 nm, and a test environment temperature of approximately 50 degrees Centigrade. A test was performed 500 hours and the numbers of secondary errors were compared. Also, the lubricating layer thicknesses before and after the test were compared.
FIG. 7 shows lubricating layer thickness comparisons from before and after the test. FIG. 8 shows the relationship between the proportion of the lubricating agent shown in chemical formula (2) in the lubricating layer after the test and the number of secondary errors.
FIG. 7 shows that the lubricating layer thicknesses increased after the test. The thicknesses were not dependent on the initial lubricating layer thickness and were about 1.8 nm. The samples with lower initial layer thicknesses had smaller proportions of the lubricating agent from chemical formula (2). Also, FIG. 8 shows that there were no secondary errors when the proportion of the chemical formula (2) was approximately 50% or less, i.e., the proportion of the lubricating agent from the chemical formula (3) was approximately 50% or more. In other words, it was found that there were no secondary errors if the proportion of the lubricating agent from the chemical formula (3) was less than the proportion of the lubricating agent from the chemical formula (2). Based on these results, a highly reliable hard disk drive with no secondary errors can be achieved with a lubricating layer containing a lubricating agent shown in chemical formula (1) or chemical formula (2) and a lubricating agent shown in chemical formula (3), where the average molecular weight is at least approximately 600 and no more than approximately 2,400 and the proportion of the lubricating agent shown in chemical formula (3) is no more than approximately 50%.
Looking at these points from another perspective, this means that secondary errors do not take place if the initial layer thickness is at least approximately 1.0 nm. The test results show that the thickness of the lubricating layer from chemical formula (3) together with the lubricating agent from chemical formula (1) or (2) tends to not go over approximately 1.8 nm. In other words, applying a lubricating agent from chemical formula (1) or (2) at a thickness of more than approximately 1.8 nm may prevent the lubricating agent from chemical formula (3) from being adhered. Thus, it would be preferable for the lubricating agent from chemical formula (1) or (2) to be approximately 1.0 nm-1.8 nm.
Comparative Example 4
A magnetic disk was made in a manner similar to that of embodiment 1. However, a lubricating agent applied to the magnetic disk is formed approximately 70% from a lubricating agent shown in chemical formula (2) and approximately 30% from a lubricating agent shown in chemical formula (4) with an average molecular weight of 3,000. The lubricating agent layer thickness was approximately 1.5 nm. This magnetic disk was installed in a magnetic disk with a mechanism for supplying a lubricating agent with an average molecular weight of 2,000. A following test was performed and secondary errors were studied.
R1—(CF 2 CF 2 O) p —(CF 2 O) q —R2
R1, R2═HO—(CH 2 CH 2 O) r —CH 2 CF 2 O— [Chemical Formula]4
[As a result, after 500 hours of testing, there were 24 errors, thus showing decreased reliability compared to the magnetic disks from the embodiments. Thus, it is believed that secondary errors do not take place when chemical formula (1) or (2) and chemical formula (3) with an average molecular weight of approximately 600-2,400 are combined in the lubricating agent and when the proportion of the lubricating agent from chemical formula (1) or (2) is at least approximately 50%.
In the lubricating agents applied to the magnetic disks in the embodiments, the molecular weight of the backbone chain of the lubricating agent shown in chemical formula (1) or (2) was 2,000. However, the present invention is not restricted to this molecular weight, and similar advantages can be obtained if the lubricating agent has an average molecular weight in the range of 1,500-6,500. In general, aggregation in the lubricating layer decreases with higher molecular weights in the lubricating agent, so a high molecular weight of about 3,500-5,500 is believed to be suitable for stable head flight.
As indicated by the embodiments, a magnetic disk that uses a mixed lubricating layer combining a lubricating agent as shown in chemical formula (1) or (2) with a lubricating agent shown in chemical formula (3) with an average molecular weight of 600-2400, with the proportion of the lubricating agent shown in chemical formula (3) being at least 50%, works well with a hard disk drive with a mechanism for supplying a lubricating agent as shown in chemical formula (3) with an average molecular weight of 600-2,400. The reliability of the resulting hard disk drive is significantly improved.
A magnetic disk with an ultrathin-layer protecting layer with a layer thickness of 1.0-5.0 nm according to the present invention provides superior recording/reproducing performance, dust resistance, and wear resistance.
|
A recording element or a reproducing element in a head generates heat that decomposes lubricating agent adhered to a slider surface near the recording/reproducing element of the head. This decomposed lubricating agent leads to corrosion of the magnetic layer and the like of the magnetic disk. The lubricating agent undergoes volume expansion due to this corrosion, creating a protrusion on the magnetic disk surface to which the lubricating agent is adhered. The magnetic disk surface to which the lubricating agent is adhered comes into contact with the magnetic head, leading to friction with the protective layer, the magnetic layer, and the like. In the worst case, this can lead to secondary errors where data recorded on the magnetic layer is erased. To prevent such secondary errors, the present invention provides a hard disk drive including:
a magnetic disk to which is applied a first lubricating agent formed as
(where p=0 or an integer of at least 1, q=0 or an integer of at least 1, and X=1-5); and
a mechanism for supplying a second lubricating agent to the magnetic disk having an average molecular weight of no more than 2,400 and no less than 600 and formed as
HOCH 2 CF 2 (OC 2 F 4 ) p (OCF 2 ) q OCF 2 CH 2 OH
(where p=0 or an integer of at least 1 and q=0 or an integer of at least 1).
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FIELD OF THE INVENTION
The present invention relates to novel perfluoro chemicals (PFC), particularly perfluorocyclic ethers and polyfluorinated compounds containing a few chlorine atoms and to a method for the preparation thereof.
BACKGROUND OF THE INVENTION
Clark and Gollan's discovery triggered the investigation on the possible use of PFC as oxygen-carrying fluids and Slovitor and Geyer's breakthrough using PFC in an emulsified form has made it realistic. One of the most important factors relating to the realization of such oxygen-carrying fluids is the synthesis of PFC which are non-toxic, have high oxygen and carbon dioxide solubilities, are stable as an emulsion for 2 years even at room temperature; and are easily removable from the body in an unchanged form after accomplishing its role with the formation of the natural blood.
Various PFC are disclosed in patents, wherein they are described as being suitable as an oxygen and carbon dioxide carrier. Almost all of the PFC patented are prepared by the electrochemical fluorination method or the cobalt trifluoride method. The cobalt trifluoride method, which is excellent in preparing perfluorohydrocarbon, is too vigorous to fluorinate ethers. That is, degradation products are caused by the cleavage of oxygen and carbon bonds. The electrochemical fluorination method, which is excellent in preparing perfluoro amine, has limited utility in preparing perfluoro cyclic ethers. Therefore, in general, perfluorocyclic ethers, which are believed to be suitable as an oxygen and carbon dioxide carrier, remain to be synthesized. The exception are the ones synthesized by the electrochemical fluorination method, such as those set forth below: ##STR1## described by Abe et al (e.g., T. Abe, E. Hayashi, H. Baba and S. Nagase: J. Fluorine Chem. 25:419 (1984), and Japanese Patent Application (OPI) Nos. 119449/79, 119471/79, 128566/79 and 44071/80.
In the present invention, the substrates followed by the prefix "perfluoro" mean substrates having all of the hydrogens replaced by fluorine atoms but containing no halogens such as chlorine, bromine and iodine, and they may be cyclic or straight-chain compounds. Furthermore, polyfluorinated compounds with a few chlorine atoms denote substrates wherein the hydrogens are mostly replaced by fluorines, but the rest of the hydrogens, usually one or two hydrogens, are replaced by chlorine atoms.
SUMMARY OF THE INVENTION
It has now been found, in accordance with the present invention, that the combined use of F-hexane (FC-72) and 1,1,2-trichloro-1,2,2-trifluoroethane (F113) as a reaction medium or solvent for the substrate in liquid-phase photofluorination broadens the substrate spectrum applicable to this method from partially fluorinated substrates to unfluorinated substrates. Therefore, perfluorocyclic ethers, which have been difficult to prepare by the conventional method such as the cobalt fluoride method as described in Industrial and Engineering Chemistry, 39:292 (1947) and J. Appl. Chem., 2:127 (1952), or electrochemical fluorination method, are now available as a result of the present invention.
The perfluorocyclic ethers and other compounds synthesized herein are perfluoro derivatives of C 10 ethers having mono- or bi-cyclic structures. Moreover, if only F113 is used, concomitant chlorination along with the fluorination occur and in the case of the fluorination of adamantane, mono- or di-chloro derivatives of perfluoroadamantane can be obtained. Therefore, by regulating the mixing ratio of F113 and F-hexane, both chlorofluorination and fluorination can be controllably carried out, as exemplified by the fluorination of decalin and adamantane described below.
It has been found that if one bromine atom is introduced into a PFC, the critical solution temperature (C.S.T.) of such a bromine-replaced PFC is drastically lowered compared to the starting PFC. This effect on the lipophilicity of PFC is desirable from the viewpoint of the excretion rate, but the bromine can act as a hook to be attacked by some chemical reagents (e.g., conc. H 2 SO 4 ).
Although the effect of chlorine might be less than the effect of bromine, it is easy to estimate that chlorine has the same kind of effect on the C.S.T. of PFC cf. c-C 8 Cl 3 F 13 O is miscible with benzene, while c-C 8 F 16 O is only slightly soluble. (George Van Dyke Tiers, J. Am. Chem. Soc., 77:4837 (1955)).
Contrary to the situation where a bromine atom is present, the chlorine atom embedded in the PFC framework is shielded by fluorine atoms against chemical attack. Further, replacement by a fluorine atom by the cobalt trifluoride method is difficult. (R. E. Banks, R. N. Haszeldine and J. B. Valton, J. Amer. Chem. Soc., 5581 (1963) and R. J. Heitzman et al, J. S. C., 281 (1963).) This inertness of chlorine was investigated through the Manhattan Project and it is concluded in its voluminous report that monochloropentadecafluoroheptane is inert enough for use in the gas-diffusion method of separating uranium isotopes as well as perfluoroheptane. (Slesser and Schram, "Preparation, Properties and Technology of Fluorine and Organic Fluorocompounds", Part IIIA, Chapter 16-23.)
It is clear from the above discussion, that chlorine-containing perfluoro chemicals have desirable properties as oxygen-carrying fluids.
DETAILED DESCRIPTION OF THE INVENTION
The PFC of the invention have high oxygen and carbon dioxide solubility and no toxicity. The emulsion prepared thereof possess high stability and low body tissue retention. The fluorine containing compounds of the invention are the perfluoro and polyfluorinated derivatives of C 10 mono-cyclic or bi-cyclic-structure-bearing ethers other fluorine containing compounds.
Examples thereof include the following compounds.
(1) F-3,4-dimethyl-bicyclo(4,4,0)-2,5-dioxadecane ##STR2## (2) F-1,3,3-trimethyl-bicyclo(2,2,2)-2-oxaoctane ##STR3## (3) F-3-ethyl-bicyclo(3,4,0)-2-oxanonane ##STR4## (4) F-cyclohexylmethyl isopropyl ether ##STR5## (5) F-1-(2-chlorocyclopentyl)cyclopentyl ether ##STR6## (6) F-1-(2-chlorocyclopentyl)n-pentyl ether ##STR7## (7) F-2-ethyl-3,6,7-trimethyl-1,5-dioxepane ##STR8## (8) F-2-ethyl-2-isopropyl-4,5-dimethyl-1,3-dioxole, ##STR9## and also of mono- and di- and tri-chloro-polyfluoro adamantanes and F-adamantane ##STR10##
In the formulae shown herein "F-" means that the compound is perfluorinated unless otherwise indicated.
This invention also includes the partially fluorinated starting materials to be fluorinated by the present process.
Examples of such partially fluorinated starting materials thereof include the following compounds:
(9) 2-(F-ethyl)-2-(2-H-hexafluoroisopropyl)-4,5-dimethyl-1,3-dioxole ##STR11## (10) 2,4-difluoro-4-(F-ethyl)-3-(F-methyl)-6,7-di-methyl-1,5-dioxepan-2-ene ##STR12## (11) 4,4-difluoro-2-(F-ethyl)-3-(F-methyl)-6,7-di-methyl-1,5-dioxepan-2-ene ##STR13## (12) 2,4,4-trifluoro-2-(F-ethyl)-3-(F-methyl)-6,7-dimethyl-1,5-dioxepane ##STR14## (13) 2-chlorohexafluorocyclopentenyl cyclopentyl ether ##STR15## (14) 2-chlorohexafluorocyclopentenyl 2,2,3,3,4,4,5,5-octafluoro-n-pentenyl ether ##STR16## (15) 5,6,7,8-tetrafluoro-2,3-dimethyl-1,4-benzodioxin ##STR17##
All of the unmarked bonds are to fluorine and H inside a ring denotes that the bonds of the ring moiety with H are saturated with hydrogen atoms.
The perfluorination can be conducted by the liquid-phase photofluorination method of Scherer and Yamanouchi (U.S. patent application Ser. No. 582,448, filed Feb. 22, 1984).
More particularly, the PFC of the present invention is prepared from a partially fluorinated or non-fluorinated compound by a liquid phase fluorination method wherein:
(a) the fluorination is carried out at -75 to +100° C. in an inert liquid medium;
(b) the inert liquid medium is F-hexane (FC-72) and/or 1,1,2-trichloro-1,2,2-trifluoroethane (F-113);
(c) undiluted or diluted fluorine (F 2 ) is used;
(d) the F 2 is maintained in stoichiometric excess at all times, so that the intermediate carbon radicals react with F 2 rather than each other;
(e) the compound to be fluorinated is metered in slowly with vigorous stirring, so that it is rapidly diluted by the solvent and its concentration is kept low compared to F 2 , and so that efficient heat dispersal occurs;
(f) UV illumination is used to initiate the fluorination reaction if spontaneous initiation is not sufficiently rapid.
In the method of the present invention, F-hexane and/or F113 is used as an inert liquid medium.
The key points in operation of the present process are as follows:
(a) The perfluorination is carried out at -75° C. to +100° C., preferably -30° to +25° C., in an inert liquid medium; preferably a perfluoro chemical which may be the reaction product itself;
(b) Either F-hexane or F113 or a mixture thereof can be used as an inert liquid medium;
(c) Molecular fluorine itself, that is, undiluted or diluted F 2 is used as perfluorinating agent;
(d) The F 2 is maintained in stoichiometric excess at all times during the reaction, so that the intermediate carbon radicals react with F 2 rather than each other;
(e) The compound to be perfluorinated is metered and charged in slowly with vigorous stirring, so that it is rapidly diluted by the solvent and its concentration is kept low compared to F 2 , and so that efficient heat dispersal occurs; and preferably,
(f) UV irradiation, preferably of wavelength 240 to 330 nm is used to initiate the fluorination reaction if spontaneous initiation is not sufficiently rapid, and further preferably;
(g) The reaction is preferably carried out by employing UV illumination, to smoothly give the corresponding perfluorinated compounds in high yield.
The substrate or starting material for preparing the PFC of the present invention which can be used in the present process include any partially fluorinated or non-fluorinated compounds as long as they are soluble in F-hexane or F113.
Examples of the partially fluorinated compounds include compounds of formulae (10) to (15) described hereinabove, those compounds described in U.S. Ser. No. 582,448, filed Feb. 22, 1984, and the like.
These partially fluorinated compounds can be prepared according to the conventional methods described in J. C. Tatflow et al, J. Chem. Soc., 763 (1964); N. Ishikawa et al, Nihon Kagakukaishi, p. 563-7 (1973); N. Ishikawa et al, J. Fluorine Chem., 18:447-57 (1981); M. Murata et al, J. Fluorine Chem., 16:75-88 (1980); and U.S. Ser. No. 582,448.
Examples of the non-fluorinated compounds include ethers having a cyclic structure (such as cyclopentenyl pentyl ether), cyclic ethers (such as chromene derivatives), tertiary amines (such as tricpropylamine), cyclic amines (such as N-methyldecahydroisoquinoline), condensed polycyclic hydrocarbons (such as naphthalene, decalin, adamantane), etc.
If the substrate to be fluorinated is sparingly soluble in F-hexane, F113 is used as co-medium and/or as the solvent for the substrate. Elemental fluorine gas is preferably used in this process, but it is not essential. Therefore, fluorine gas diluted with inert gas such as nitrogen, helium and argon is also usable in this process.
Preparation of the Starting Substrate
The preparation of the starting substrate is carried out based on typical fluorine chemistry such as the nucleophilic substitution of perfluoroolefins and hexafluorobenzene with various nucleophiles.
The present invention is further illustrated by the following examples which should not be construed as limiting the present invention thereto.
EXAMPLE 1
2,3-Butanediol (2.7 g, 0.03 mol) was added to a mixture of perfluoro-2-methyl-2-pentene (D-II) (10.8 g, 0.036 mol) and triethylamine (6.06 g, 0.06 mol) in 60 ml of acetonitrile. The mixture was stirred with a magnetic stirrer for 1 hour at room temperature. The reaction mixture was poured into water (200 ml) and an organic layer was separated. The aqueous layer was extracted with 4 portions of 50 ml of F113. The organic layer and the extracts were combined and dried over sodium sulfate overnight. F113 was distilled out and that which remained was distilled under reduced pressure using a semi-micro distilling apparatus with a 6-inch jacketed column to give 6 fractions whose compositions are summarized in the following table.
The substance (4.6 g) collected in a trap cooled by liquid nitrogen was almost pure (I) (41% yield).
______________________________________ Product Distribution Boiling Range Amount (I) (II) (III)Fraction (°C.) (g) (%) (%) (%)______________________________________Trap 4.60 93 7 --F-1 28-35/1.7 mmHg 0.39 63 37 --F-2 35-36/1.7 mmHg 0.35 43 57 --F-3 43-46 0.99 22 73 5F-4 50-52 0.77 9 83 8F-5 52-57 0.78 -- 86 14F-6 57-60 0.38 -- 79 21Residue 1.45 -- 25 75______________________________________
The 19 F-NMR data for each chemical structure (CFCl 3 reference) depicted below is also provided. ##STR18##
EXAMPLE 2
Triethylamine (6.06 g, 0.06 mol) was added to a solution of D-II (10.8 g, 0.036 mol) in 30 ml of F113 to give a suspension of a complex thereof. Into this suspension was added 2,3-butanediol (2.7 g, 0.03 mol) dispersed in 90 ml of F113 with vigorous stirring.
The insoluble material which arose after stirring for 18 hours at room temperature was filtered off, and F113 was distilled out. The resulting material was distilled in the same manner as in Example 1 to give 3 fractions whose compositions are summarized in the following Table.
______________________________________ Product Distribution Boiling Range Amount (I) (II) (III) (IV)Fraction (°C.) (g) (%) (%) (%) (%)______________________________________Trap 4.15 6.7 4 1 --F-1 35-45/0.6 mmHg 5.72 1.1 4 1 --F-2 45 0.4 -- 1.7 1 --F-3 55-65 4.88 -- -- 1 6.4______________________________________ ##STR19##
Chemical shifts are minus toward upper field from CFCl 3 .
EXAMPLE 3
Cyclopentanol (23 g, 0.27 mol) and sodium metal (5.6 g, 0.24 mol) were refluxed with 25 ml dry tetrahydrofuran (THF) overnight. The reaction mixture was diluted with 200 ml of dry ether and then added to 1,2-dichlorohexafluorocyclopentene (49 g, 0.2 mol) in 100 ml of dry ether at room temperature with stirring over 20 minutes. After the completion of the addition, the reaction mixture was heated to reflux for 2 hours. The reaction mixture was poured into ice water (150 ml) and the organic layer was separated. Then the aqueous layer was extracted with 4 portions of 100 ml of ether. Next, the organic layer and the ether extracts were combined and dried over CaCl 2 overnight. Thereafter, the solvent was distilled out at atmospheric pressure. That which remained was distilled under reduced pressure to give the desired 2-chlorohexafluorocyclopentenyl cyclopentyl ether in 79% yield based on the 1,2-dichlorohexafluorocyclopentene used.
The 19 F-NMR measured shows three signals with relative intensities 1:1:1 at -106.1, -111.1 and -125.5 ppm from the CFCl 3 reference. Molecular ion (m/z 294, 296), ##STR20## (m/z 69) were found in the mass spectrum.
EXAMPLE 4
2,2,3,3,4,4,5,5-Octafluoro-n-pentanol (11.6 g, 0.05 mol) and sodium metal (1.4 g, 0.05 mol) were added to 100 ml of dry ether and stirred at room temperature overnight. The solution obtained was added into a solution of 1,2-dichlorohexafluorocyclopentene (12.3 g, 0.05 mol) in 100 ml of dry ether. The reaction mixture was poured into 150 ml of ice water and an organic layer was separated. The aqueous layer was then extracted with 3 portions of 100 ml ether. Next, the extracts were combined with the separated organic layer and dried over sodium sulfate overnight. The desired 2-chlorohexafluorocyclopentyl 2,2,3,3,4,4,5,5-octafluoro-n-pentyl ether (38°-42° C./0.3 mmHg) was obtained in 50% yield based on 1,2-dichlorohexafluorocyclopentene used by vacuum distillation.
The 19 F-NMR (neat φ*): -108.3 (2F), -110.5 (2F), and -126.1 (2F) are to F 3 on the ring and -117.2 (2F), -121.3 (2F), -126.1 (2F), -134.5 (2F) are to the one alkyl chain. MS: M + (m/z 440, 442), M-F + (m/z 421, 423), ##STR21## (m/z 209, 211) were observed in relative intensities of (48.9, 16.6) (18.0, 5.7), (85.9, 28.1) and 100, 33.8), respectively.
EXAMPLE 5
Hexafluorobenzene (13.9 g, 0.11 mol) and 2,3-butanediol (67.7 g, 0.72 mol) were refluxed in the presence of 1.15 mol of NaOH. After work up of the 3-hydroxy-2-butoxypentafluoro benzene (19 g) boiling at 64°-70° C./0.35 mmHg (73% yield based on hexafluorobenzene) was obtained by vacuum distillation.
3-Hydroxy-2-butoxypentafluorobenzene thus obtained was refluxed with dimethyl formamide (DMF) in the presence of K 2 CO 3 . After work up of the reaction mixture, ##STR22## was obtained as crystal in 58% yield.
m.p. 91°-93°
19 F-NMR:
AA'BB' type
A-163.1
B-169.5
from CFCl 3 reference liquid-phase photofluorination
EXAMPLE 6 ##STR23## (7 g) obtained in the Example 5 was dissolved in F113 to make a 4 w/v% solution. F113 was used as the reaction medium instead of F-hexane. The photofluorination was carried out according to the method described in U.S. patent application Ser. No. 582,448, filed Feb. 22, 1984 (which is a continuation-in-part application of Ser. No. 300,273, filed Sept. 8, 1981, corresponding to EP-A-77114). After the reaction was completed, the reaction mixture was washed with saturated aqueous NaHCO 3 , 10 w/v% aqueous sodium thiosulfate, and water in that order.
An organic layer separated was dried over Na 2 SO 4 .
The solvent was distilled off and that which remained was fractionally distilled using a 6-inch long vacuum-jacketed column packed with stainless steel gauze to give the fraction boiling at 126°-133° C. which is mainly the desired ##STR24## compound. The yield was 14%.
EXAMPLE 7
Cineal (8 g) was dissolved in F113 to make a 4 w/v% solution which was used as a feeding solution. FC-72 was used as a reaction medium. After fluorination was completed, the reaction mixture was treated in the same manner as the previous examples. The fraction (7.6 g) boiling at 121°-123° C. was mainly the desired F-1,3,3-trimethyl-bicyclo(2,6,2)-oxaoc. The yield was 31%.
EXAMPLE 8
A 4 w/v% solution of 2-ethyloctahydrobenzofuran (8 g) in F113 (200 ml) was pumped into the reaction medium of FC-72 (500 ml) saturated with fluorine and irradiated with a UV lamp (100 W Hg lamp). After the reaction was completed, the reaction medium was treated as in the previous examples.
The main fraction boiling at 124° C. was the desired F-2-ethyloctahydrobenzofuran (30% yield).
EXAMPLE 9
2-Methoxy-2-phenyl-F-propane was fluorinated in same manner as in the Example 8 using FC-72. The desired F-2-cyclohexyl-2-methoxypropane was obtained in 20.8% yield, along with F-isopropylhexane (9.9%) and F-isopropoxymethylcyclohexane (19.7%). The boiling range of the fraction containing F-2-cyclohexyl-2-methoxypropane and F-isopropoxymethyl-cyclohexane is 130°-132° C. F-2-cyclohexyl-2-methoxypropane
______________________________________ ##STR25##
______________________________________C(CF.sub.3).sub.2 -66.65OCF.sub.3 -52.55F -179.3Fcc' -127.0, -115.4Fbb' -138.1, -121.8Faa' -142.1, -124.2______________________________________
F-isopropoxymethylcyclohexane
______________________________________ ##STR26##
______________________________________Faa' -142.41, -124.53Fbb' -140.30, -122.75Fcc' -131.79, -119.76CF(ring) -187.4 ##STR27## -146.0CF.sub.2O 69.16CF.sub.3 81.28 Ja-a' = 288.1 Hz Jb-b' = 286.0 Jc-c' = 297.7______________________________________
EXAMPLE 10
A 10 w/v% solution of 2-chlorohexafluorocyclopentenyl cyclopentyl ether (10 g) dissolved in FC-72 (100 ml) was pumped into the reaction medium of FC-72 saturated with fluorine and irradiated with an UV lamp (100 W Hg lamp). After the reaction was completed, the reaction mixture was treated as in the previous examples. The fraction boiling at 146°-149° C. was mainly the desired F-1-(2-chloropentyl)cyclopentyl ether. The yield was 29%.
EXAMPLE 11
A 20 w/v% of 2-chlorohexafluorocyclopentenyl 2,2,3,3,4,4,5,5-octafluoro-n-pentyl ether (11.6 g) dissolved in F113 was pumped into F113 saturated with fluorine and irradiated with an UV lamp (100 W Hg lamp). After the reaction was completed, the reaction mixture was treated as in the previous examples. The fraction boiling at 141°-147° C. was mainly the desired F-1-(2-chloropentyl)cyclopentyl. The yield was 38%.
EXAMPLE 12
Ten g of 2-(F-ethyl)-2-(2H-hexafluoroisopropyl)-4,5-dimethyl-1,3-dioxole was dissolved in F113 to make a 8 w/v% solution. This solution was pumped into a 1:1 by volume mixture of F113 (500 ml) and FC-72 saturated with fluorine at a temperature of -20° to -30° C. and irradiated with an UV lamp (100 W Hg lamp). After the fluorination was completed, the reaction mixture was worked up as in the previous examples.
The fractional distillation using a 6-inch vacuum jacketed column packed with a stainless steel gauze gave a fraction boiling at 130°-132° C. (5.32 g, yield 37%), which mainly consists of the desired F-2-ethyl-2-isopropyl-4,5-dimethyl-1,3-dioxole.
EXAMPLE 13
The mixture (8.6 g) of 2,4-difluoro-4-(F-ethyl)-(F-methyl)-6,7- dimethyl-1,5-dioxepan-2-ene and 4,4-difluoro-2-(F-ethyl)3-(F-methyl)-6,7-dimethyl-1,5-dioxepan -2-ene purified from the fractions obtained in the Examples 1 and 2 was fluorinated using F113 both as a solvent for the substrate and as the reaction medium. After the reaction mixture was worked up as in the previous examples, the desired F-2-ethyl-3,6,7-trimethyl-1,5-dioxepan was obtained as the fraction boiling at 134°-139° C. by the fractional distillation using a 6-inch long vacuum jacketed column. The yield was 36%.
(M-F) - (m/z 513), (M-C 2 F 5 ) - (m/z 413) and (M-CF 3 ) - (m/z 463) were found in their negative ion mass spectra. A small amount of monochlorofluorinated derivative whose chlorine position has not yet been ascertained, concomitantly formed in this procedure, supported by the observation of (C 10 F 19 ClO 2 -C 2 F 5 ) - (m/z 431, 429) in the negative mass spectrum.
EXAMPLE 14
Decahydronaphthalene (8 g) was dissolved in F113 to make a 4 w/v% solution. This solution was pumped into a 3:1 by volume mixture of FC-73 and F113 (600 ml) saturated with undiluted fluorine at a temperature of -30° to -20° C. and irradiated with an UV lamp (100 W Hg lamp).
The reaction mixture was worked up as in the previous examples. The solvent was evaporated and that which remained was fractionally distilled using a 6-inch long vacuum jacketed column packed with stainless steel gauze. The five fractions obtained were analyzed by GC-MS and the results are summarized in the following table.
All of the compounds obtained are known and assigned by the comparison with the authentic samples.
TABLE 1______________________________________Composition of each fraction obtained by thefractional distribution of the reaction mixtureof the fluorination of decahydronaphthalene Boiling A-Frac- Range mount Product Distributiontion (°C.) (g) (I) (II) (III) (IV) (V) (VI)______________________________________F-1 89 1.4 6.0 24.2 9.7 6.6 2.6 0.3F-2 89-136 3.7 -- -- 7.0 7.6 69.0 11.4F-3 136-40 5.4 -- -- 0.9 1.0 80.9 14.6F-4 140 2.5 -- -- -- -- 81.2 17.0F-5 140 1.3 -- -- -- -- 77.7 19.4Resi- 3.4due______________________________________ I: F--methylcyclohexane II: F--1,2dimethylcyclohexane III: F--1ethyl-2-methylcyclohexane IV: F--npropylcyclohexane V: F--transdecalin VI: F--cisdecalin The products distribution of (I)-(VI) was expressed by a percentage of each peak area against the total peak area on their gas chromatogram.
No chlorine-containing compound was found in the reaction of the starting cis- and trans-decahydronaphthalene. About an 8:2 by mol mixture of trans- and cis-perfluorodecalin was obtained in 50% yield.
EXAMPLE 15
Adamantane (8 g) was dissolved in F113 to make a 4 w/v% solution. This solution was pumped into 600 ml of F113 saturated with undiluted fluorine at a temperature of -20° to -10° C. and irradiated with an UV lamp (100 W Hg lamp). The reaction mixture was worked up as in the previous examples. The solid material (sublimables at room temperature) obtained by removing the solvent was about a 1:1 by volume mixture of perfluoro and monochloropolyfluoro adamantane. Other minor components were dichloro- and trichloropolyfluoro adamantane.
The structures are supported by M - ions formed in their negative ion mass spectrum. C 10 F 18 - (m/z 462) C 10 F 17 35 Cl - (m/z 478) C 10 F 16 35 Cl 37 Cl (m/z 496) C 10 F 15 35 Cl 2 37 Cl (m/z 512).
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
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The present invention relates to novel perfluoro chemicals (PFC), particularly perfluorocyclic ethers and polyfluorinated compounds containing a few chlorine atoms and to a method for the preparation thereof.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a ceramic leadless package usable for mounting a small size electronic device such as a semiconductor or the like and connecting it to a circuit substrate. And also, the invention relates to a process for manufacturing such a ceramic leadless package.
(2) Description of the Prior Art
As the ceramic package of this type, there have hitherto been employed a laminated type chip carrier and a flat type chip carrier, but they have the following drawbacks: (1) When the top surface of the package is flat, for instance, as in the package described in U.S. Pat. No. 3,404,214, external terminals provided on the top surface of the package are substantially flush with the top surface of the package, so that it is necessary to separate these adjacent terminals from each other by grooves. If there is no groove, when the external terminals or the top surface of the package is soldered to another substrate, short circuit is apt to occur between the terminals due to the bridging of the solder.
(2) When the package is not provided on its side surface and bottom surface with connection conductors as in the abovementioned package, if the top surface of such a package is connected to another circuit substrate, the soldering for terminals cannot sufficiently be confirmed from the exterior and the soldered area is small, so that the adhesive strength becomes insufficient.
(3) When the package surface is flat as in the laminated type chip carrier or the flat type chip carrier, there remains substantially no space between the package surface and another circuit substrate after the package is connected to the circuit substrate, and hence electronic components cannot be attached to the mounting area occupied in the package, so that the packaging density for the circuit substrate is restricted. Moreover, since there is a limit on the connecting area between the top surface of the package and the circuit substrate, the heat dissipation is not achieved sufficiently.
(4) As disclosed in U.S. Pat. No. 3,483,308 (Japanese Patent Application Publication No. 49-41,901), there is proposed a supporting member for an electronic device, which is produced by subjecting a flat ceramic carrier body provided on its bottom surface with projections to a metallization. In this type of the package, conductors extending over the respective projections are formed after the molding or firing of the ceramic body, so that the mass-productivity is poor, and it is difficult to make the body lighter and thinner.
SUMMARY OF THE INVENTION
It is, therefore, an object of the invention to solve the above-mentioned drawbacks, and to provide a ceramic leadless package wherein a plurality of metallizing patterns and external terminals are printed on an unfired plate-like ceramic green sheet, subjected to a hot pressing so as to make a wave shape of the pattern, for instance, to make the top surface of the external terminal portion convex and the bottom surface thereof concave, and then fired to form external terminal portions as a conductor owing to the metallization of the above pattern.
According to the invention, there is the provision of a ceramic leadless package comprising a ceramic substrate having first and second opposite surfaces parallel to each other, a plurality of ceramic projections protruding from the first surface and separated from each other, a metallized layer provided on the end surface of each of the ceramic projections, an electrode portion for an electronic device such as a semiconductor provided on the central portion of the second surface so as to mount the electronic device on the second surface, a plurality of metallized layers extending from the circumference of the ceramic substrate toward the electrode portion for the electronic device, a side metallized layer connecting each metallized layer of the first surface to the corresponding each metallized layer of the second surface, wherein the metallized layer of the first surface and the metallized layer of the second surface correspondingly are convex and concave at a position corresponding to each ceramic projection and are connected to each other through the side metallized layer, and the metallized layers provided on the second surface are spaced from each other and extend toward the electrode portion for the electronic device provided on the central portion of the second surface, and the metallized layers existent in the concave portion and a greater part of the metallized layers extending toward the center of the second surface are covered with an insulating layer.
Another object of the invention is to provide a ceramic leadless package in which the electrode portion for the electronic device is provided with a metallized layer drawn from this electrode portion to a corner of the ceramic substrate and serving both as a plating electrode and as an index corner.
Still another object of the invention is to provide a ceramic leadless package in which the metallized layer provided on each ceramic projection extends over the projection toward the center of the first surface to a certain extent.
A further object of the invention is to provide a ceramic leadless package in which the metallized layer drawn from the electrode portion for the electronic device to the corner of the ceramic substrate is provided with a metallized layer extending over the side and back surfaces of the corner.
According to the invention, there is further provided a process for manufacturing a ceramic leadless package, which comprises steps of: punching a ceramic green sheet at predetermined positions to form through-holes for side metallized layers corresponding to a ceramic leadless package unit; printing the inner circumferential surface of each of the through-holes with a metallizing paste to form a side metallizing layer; screen-printing a first surface of the ceramic green sheet with a metallizing paste to form a plurality of metallizing layers for connecting to an external electronic circuit, each extending from the circumference of the through-hole and being electrically connected to the side metallizing layer and at the same time screen-printing a second surface of the ceramic green sheet with a metallizing paste to form an electrode portion for an electronic device to be mounted thereon and a pluality of metallizing layers, each extending from the circumference of the through-hole toward the electrode portion for the electronic device and being electrically connected to the side metallizing layer; screen-printing the metallizing layers of the second surface except a desired portion of the metallizing layer near the electrode portion for the electronic device with an insulating paste to form an insulating layer; hot-pressing only a region including the through-hole and a part of the insulating layer adjacent thereto up to a given depth to protrude a part of each metallizing layer from the first surface of the ceramic green sheet; and firing and plating the resulting pressed product.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in detail with reference to the accompanying drawings, wherein:
FIG. 1 is a flow sheet illustrating the process for manufacturing ceramic leadless packages according to the invention;
FIG. 2 is a plan view of a ceramic green sheet to be used in the invention;
FIG. 3 is a plan view illustrating such a state that through-holes are punched in the ceramic green sheet;
FIGS. 4 and 5 are rear and plan views illustrating such states that patterns are printed with a metallizing paste on the back and front surfaces of the ceramic green sheet, respectively;
FIG. 6 is a plan view illustrating such a state that a part of the ceramic green sheet is covered with an insulating layer;
FIG. 7 is an enlarged sectional view of the outer peripheral portion of the metallizing pattern in the package after the hot-pressing; and
FIGS. 8a, 8b, 9 and 10 are plan, fragmentary, rear and side views of the package illustrating such a state that the green sheet is fired, subjected to a plating on the metallizing layers and separated into individual sections, respectively.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will successively be described on every steps in accordance with the flow sheet shown in FIG. 1. First, alumina powder, a flux, an organic binder, a plasticizer and a solvent are mixed at a given mixing ratio to prepare a ceramic slurry, which is shaped into a tape by means of a knife coater. Then, the resulting tape is dried and cut in a given length to form a plurality of unfired ceramic green sheets 1 as shown in FIG. 2.
In FIG. 2, a reference numeral 2 denotes a notch for determining a working position in the side portion of the ceramic green sheet. As shown in FIG. 3, plural sets of through-holes 3 penetrating from one surface to the other, each set corresponding to a contour of a ceramic leadless package body, are punched at a predetermined interval in the green sheet 1. A reference numeral 4 denotes a guide hole for use in printing and hot-pressing steps, which is formed in each corner of the green sheet 1 during the punching, and a reference numeral 5 denotes an index to be used as a mark for actually mounting a ceramic package.
In the next step, the inner surface of each of the through-holes 3 is printed from one surface of the green sheet 1 to the other thereof with a metallizing paste. As the metallizing paste, there may be used the conventionally known tungsten-base paste and molybdenum-base paste.
Thereafter, as shown in FIG. 4, a back pattern 6 is printed in a thickness of 10-50 μm on the first surface of the green sheet 1 with the metallizing paste.
Next, the green sheet 1 having the printed back pattern 6 is turned over, on which is printed a front pattern 7 as shown in FIG. 5. A reference numeral 8 is a metallizing portion printed in a central part of a contour 9 of a section constituting the front pattern 7, which corresponds to an electrode portion for mounting an electronic device thereon. Peripheral pattern 10 corresponding to side electrodes of the section in the front pattern 7 are separated from each other and metallize-printed so as to extend at least toward the printed metallizing portion 8 for mounting the electronic device. A reference numeral 11 is an index pattern printed at a corner of the section in the front pattern 7 and connected to the printed metallizing portion 8 through a single metallizing line, which is used as an electrode for plating after the firing. The front pattern 7 is also printed in a thickness of 10-50 μm with the metallizing paste.
The order of the metallize-printing for the back pattern, front pattern and the like on the ceramic green sheet is not always the same as shown in FIG. 1, but may be determined in view of the efficiency of the printing steps.
Then, as shown in FIG. 6, an insulating layer pattern 12 is formed by covering the middle areas of the peripheral patterns 10 of FIG. 5 with an insulating paste. In FIG. 6, the pattern 12 is shown as a white portion corresponding to the middle areas of the peripheral patterns 10. The insulating layer 12 is printed in a thickness of 10-50 μm.
Next, only a part of each of the peripheral patterns 10 covered with the insulating layer 12 and located near the through-hole 3 is hot-pressed in a direction of the back surface (i.e. a first surface) from the front surface (i.e. a second surface) of the green sheet 1 so as to make the front surface concave and the back surface convex, whereby the separation between the adjoining peripheral patterns 10 is further ensured.
In FIG. 7 is enlargedly and sectionally shown a peripheral part of the ceramic green sheet 1 after the hot-pressing, wherein reference numerals 1A and 1B show the concave and convex parts of the ceramic green sheet 1 and the inner surface of the through-hole 3 has a printed metallizing layer.
The hot-pressing of the pripheral pattern as mentioned above is carried out at a temperature of 50°-100° C. under a pressure of 10-100 kg/cm 2 .
Next, the ceramic green sheet 1 is subjected to knife-cutting in transverse and longitudinal directions to form snap lines. For this purpose, there are used marks 13 and 14 for the formation of snap lines capable of dividing the ceramic sheet into individual ceramic leadless packages.
Next, the ceramic green sheet 1 is fired at a temperature of about 1,500° to 1,600° C. in a reducing atmosphere, whereby the printed metallizing layers 6, 7, 8, 10 and 11 are changed into electrically conductive metallized layers.
After the printed metallizing portions in the front and back patterns 7 and 6 and the through-holes 3 are changed into the metallized layers by firing, the resulting ceramic sheet is plated with nickel, gold, silver or the like at positions corresponding to the metallized layers. As the plating method, either an electroplating or electroless plating may be used. In this case, the portions of the metallized layers not covered with the insulating layer 12 are plated.
In the next step, the ceramic substrate is divided along the snap lines passing through-holes punched in the first step to obtain ceramic leadless packages as a finished product.
The division of the ceramic substrate into the ceramic leadless packages may be performed prior to the plating. Alternatively, when the division is carried out by a laser scribing method, the formation of snap lines as described above is not always required.
The detail of the resulting ceramic leadless package is shown in FIGS. 8a, 8b, 9 and 10. FIGS. 8a, 8b, 9 and 10 are a plan view of the front surface (second surface), a fragmenary view, a rear view of the back surface (first surface), and the side view in the finished product, respectively.
In FIGS. 8a, 8b, 9 and 10, a reference numeral 15 is a ceramic leadless package body, a reference numeral 16 an electrode portion for an electronic device provided in the central part of the body, a reference numeral 17 an electrode corresponding to the peripheral pattern formed on the front surface (second surface), a reference numeral 18 a through-hole electrode provided on the through-hole, a reference numeral 19 an electrode provided on the convex part of the back surface (first surface), and reference numerals 20 and 21 concave and convex parts of the ceramic substrate produced by the hot-pressing. The electrode 17 is electrically connected to the corresponding electrode 19 through the through-hole electrode 18. A reference numeral 22A indicates an index corner of the front surface, a reference numeral 22B indicates an index corner of the back surface, and a reference numeral 22C indicates a side portion index corner connecting the index corners 22A and 22B. A reference numeral 23 is a lead electrode for connecting the index corner 22A to the electrode portion 16.
Since the ceramic leadless package according to the invention can directly be attached to another circuit substrate, it is not necessary to attach any lead members to the ceramic leadless package. Therefore, an integrated circuit may properly be mounted on the ceramic leadless package before or after the division of the ceramic substrate.
According to the invention, the ceramic green sheet is shaped into a plate-like tape, and the punching of through-hole, the metallize printings for through-hole, back pattern and front pattern, and the printing for insulating layer are all made on the plate-like ceramic green sheet, so that the tape-shaping, the metallize-printing and the insulating layer-printing can be performed extremely effectively. Further, since the provision of the insulating layer enhances the electric insulation between the adjacent peripheral patterns and also smoothens the unevenness due to the gauges of the peripheral patterns, it contributes to improve the airtightness in the sealing of the electronic device and the anti-corrosion property of the peripheral patterns and further prevents the damaging of the printed peripheral patterns in the hot-pressing. Since the peripheral pattern electrodes on the front and back surfaces are correspondingly pressed in such a manner that they are concave in the front surface (second surface) and convex in the back surface (first surface), short circuit is not caused between the adjacent peripheral pattern electrodes at the front surface. That is, ceramic leadless packages of thin and light type can be mass-produced according to the invention.
Moreover, since the electrode portions at the front surface are concave in the package according to the invention, solder-bridging hardly occurs in the soldering and also the product yield is enhanced, and the area for soldering can be widened and the connection state may be confirmed easily from the exterior.
In addition, when the electronic device is mounted to the package and sealed therein, the sealing strength and airtightness are excellent because the peripheral portion of the package provided with the insulating layer is concave.
Further, since the package according to the invention is thin and the electrode portions at the back surface thereof are convex to give a space in the bottom, the packaging of another circuit substrate can be attained three-dimensionally, so that the packaging density can be increased and the heat dissipation can be improved. Thus, according to the invention, the thin and light type ceramic leadless packages can cheaply be provided in industry.
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A ceramic leadless package for integrated circuits, which comprises a ceramic substrate having first and second opposite surfaces, a plurality of ceramic projections protruding from the first surface, a metallized layer provided on the end surface of each of the projections, an electrode portion for an electronic device provided in the central portion of the second surface, a plurality of metallized layers extending from the circumference of the substrate toward the electrode portion, and a side metallized layer connecting the above metallized portions in the first and second surfaces to each other. In the package of this type, the metallized layers of the first and second surfaces are concave and convex at a position corresponding to each projection, respectively, and a greater part of the metallized layers of the second surface are covered with an insulating layer.
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FIELD OF THE INVENTION
This invention relates to the controlled fracturing of rock adjacent to well bores to increase fluid flow rates for natural gas, petroleum, water, etc.
BACKGROUND OF THE INVENTION
Conventionally, a rock formation bearing a well bore hole may be fractured to increase fluid flow rates through the use of high pressure water to create cracks or increase the size of cracks in the surrounding rock. Since water is essentially non-compressible, a great deal of pump work must be effected to open up a sizeable amount of voids contained in the cracks. Typically, water must be raised to several thousands of pounds pressure per square inch, pumped into the well hole or bore, and a typical well may require as much as 20,000 gallons of water under high pressure to achieve any effective rock fracturing about the well bore. Such equipment to achieve that end is formidable in size, complexity and cost. In most cases, drilling at another location represents a less expensive choice.
SUMMARY OF THE INVENTION
The present invention is directed to a process of raising the pressure within a well hole or well bore extending into the earth by the introduction of a combustible mixture of a gaseous oxidizer and a fuel to a sealed length of the well bore or bore hole, and igniting the mixture. The resulting combustion raises the pressure of the gas momentarily to a substantial value such that the pressure rise increases the flow of fluid from the surrounding earth into the well by fracturing the rock surrounding the well or bore hole. The oxidizer may comprise pure oxygen, compressed air or a mixture of the two. By varying the pressure to which the reactants are raised prior to ignition, the peak combustion pressure may be thereby controlled. Preferably, the combustion pressure increase is transmitted into or through a volume of liquid contained below the fuel and gaseous oxidizer mixture wherein combustion occurs. The process has application to water wells, oil wells or gas wells. The bore hole may be sealed at the top thereof by a packer. Preferably, the top packer is designed to allow the flow of reactant to a sealed bore hole volume below the top packer, and the top packer is provided with ignition means to ignite combustion of the fuel and gaseous oxidizer.
The process may involve the segregation of the well or bore hole into upper and lower sealed lengths separated by a check valve with the process steps involving the introduction of the combustible mixture of the gaseous oxidizer and fuel into the first sealed length of the well or bore hole and the ignition of the mixture within that sealed length to create a momentary high pressure wave within the upper sealed volume. The check valve opens to transmit the pressure wave into a second sealed volume of the well or bore hole, thereby allowing a step-wise increase of the pressure in the second sealed chamber. Successive firings of combustible mixtures in the first sealed volume may function to create a steady pressure in the second sealed volume nearly equivalent to the peak transitory pressures realized during combustion in the first sealed volume.
A better understanding of the principles of the invention may be appreciated from a study of the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a vertical sectional view of a water well for gaseous detonation fracturing under the method of the present invention.
FIG. 1b is an enlarged vertical sectional view of the water well shown in FIG. 1a using the method of gaseous detonation in the well for rock fracturing.
FIG. 2 is a vertical sectional view of a deep oil well illustrating a modified form of the gaseous detonation fracturing method of the present invention.
FIG. 3 is a pressure time curve for a typical gaseous detonation employed in the detonation fracturing method of the present invention.
FIG. 4 is a vertical sectional view of a well employing a modified set up for utilizing an alternate gaseous detonation process forming yet another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention has general application to wells or bore holes for the extraction of fluids such as natural gas, petroleum or water from earth formations. In that regard, reference to FIG. 1a shows a typical water well indicated generally at W formed by drilling a well bore or bore hole 10, which bore hole 10 is drilled vertically downwardly within an earth formation, indicated generally at E, from ground level G. The bore hole 10 passes through an outer surface layer of soil as at 12 and thence through rock 11 to a vertical distance below an inclined crack 13 within the rock 11. Water contained in the ground follows the seam of the crack 13 and collects within the bore hole 10 to a given level as at 16 and forming a volume of water 17 therein.
For illustration purposes, an assumption is made that the rate of water inflow from crack 13 to bore hole 10 is relatively low, for instance one-half gallon per minute. Where an increased flow is required, the choice is limited to either drilling of the bore hole 10 deeper to encounter further cracks, where water may seep to the bore hole 10 or the drilling of a new well at another location, unless an increased flow from existing cracks 13 may be achieved.
Typically, the well driller will attempt to increase the water flow by blasting several sticks of dynamite placed within the bottom 10a of the bore hole 10. Often this is successful, and the crack as at 13 opens further into the rock formation 11 intercepting additional zones bearing water. Further, the crack 13 may be widened which may function to allow an increased flow. However, in many cases, the intense blast created by the detonation of the dynamite or explosive results in considerable damage to the well. If excessive, it simply precludes further use as a water or other liquid source.
As an alternative to blasting, conventionally, hydrofracturing is employed. This involves the application of water raised to several thousands pounds of pressure per square inch and pumped into the hole. A typical well of extended length may require as much as 20,000 gallons of water. The equipment required to achieve hydrofracturing is formidable in size, complexity and cost.
In hydrofracturing, there is a requirement that cylindrical casing formed of a strong metal be securely attached to the rock formation 11 and projecting downwardly from a point in the vicinity of the ground level. Physical attachment is normally effected by means of a mass of concrete, as at 15, poured between the well bore 10 and the earth formation, whether it be the soil 12 or the rock 11, and wherein most of the attachment of the casing 14 is effected between the casing 12 and the rock formation 11 through which casing 14 passes.
The present invention involves effecting a gaseous detonation by an effective, simple and inexpensive manner within the well bore 10. As seen in FIG. 1b, which is an enlarged vertical sectional view of the well W of FIG. 1a, a cap 18 or a special packer is sealably and fixedly mounted to the upper end of casing 14 and the interior of the bore hole 10 is sealed off from the outside at or near ground level G. Cap 18 may take the form of a rather thick metal plate as at 19, as shown, welded to the top of casing 14 and projecting interiorly within the same. Alternatively, a "packer" of conventional design may be employed. The plate 19 bears a supply tube 20 through which air or oxygen is supplied to the interior of the extended bore of volume 24, as formed by casing 14, along with a supply of propane or other gaseous or liquid fuel by way of tube 21, the oxidizer and fuel being fed under pressure as indicated by the arrows respective to tubes 20 and 21. Tube 21 forms a Tee with tube 20, such that both the fuel and gaseous oxidizer are supplied under pressure to the interior of bore hole 10 via sealed casing 14. Alternatively, air, oxygen or a mixture of both may be passed through tube 20 under pressure to the interior of casing 14. The fuel and oxidizer mixture (optionally stociometric) is pumped into the bore hole volume 24 until a determined desired pressure is realized throughout the extent of the captive volume of fuel and oxidizer mixture. The mixture is ignited by energizing a spark plug 22 and the creation of a spark across gap 23 between the points of the electrodes of spark plug 22.
Depending upon the gas pressure prior to ignition, the peak pressure reached by the detonation or deflagrating (gases) can be controlled.
EXAMPLE NO. 1
Assuming the static level 16 of water 17 within the bore hole 10 to be 100 feet below the cap 18 at the top of casing 14 and with a well diameter averaging seven inches, the filling of the bore hole 10 with a combustible gas mixture to 500 psig requires approximately 915 cubic feet of gas measured at standard pressure and temperature (14.7 psig and 60° F.). If the oxidizer is air, the weight of this amount of air is about 60 pounds. Thus, the fuel/gas component is only about five pounds or one-twentieth the standard 100 pound tank of propane. However, this amount of propane represents a tremendous quantity of energy.
The peak pressure of combustion can be estimated using standard combustion equations. Assuming perfect, stociometric combustion of air plus propane
C.sub.3 H.sub.8 +5O.sub.2 +18.8N.sub.2 →3CO.sub.2 +4H.sub.2 O+18.8N.sub.2
24.8 moles of reactants form 25.8 moles of products. Assuming a peak combustion temperature of 3,600° F., the adiabatic maximum gas pressure becomes ##EQU1## or 4,061 psig. The actual peak pressure will be somewhat less due to heat loss to the well bore hole walls.
An advantage of the gaseous detonation method of the present invention is the controlled rise of the pressure curve. It is not the nearly instantaneous and destructive pressure rise resulting from the ignition of a solid explosive. FIG. 3 constitutes a pressure/time curve of a typical gaseous detonation within a long bore hole 10. The curve 30 shows that the pressure rises rapidly (but not destructively) to its maximum value and then the pressure decays slowly as the heat from the gas passes into the cold rock 11.
The peak pressure of over 4,000 psig is usually more than sufficient to open and extend tight cracks such as crack 13 within the rock 11, FIG. 1a. In some cases, higher initial pressures may be required. In others, sand grains may be added to the well water 17 and upon detonation, the increased pressure forces the sand into the cracks to help keep the cracks open once the pressure wave has passed longitudinally.
EXAMPLE NO. 2
Alternatively, pure oxygen may be used in place of compressed air. Again, assuming perfect, stociometric combustion of oxygen plus propane
C.sub.3 H.sub.8 +5.5O.sub.2 →3CO.sub.2 +4H.sub.2 O
Six moles of reactants create seven moles of products. Again, assuming an initial pressure of 500 psig and a peak combustion temperature of 5,400° F., the peak pressure reaches 6,900 psig neglecting heat losses. This is nearly double that for compressed air and heat outputs are increased several-fold. Propane consumption increases to about twenty-five pounds per firing.
In the illustrated embodiment of FIGS. 1a/1b, the packer or plate 19 is positioned at the top of the cylindrical steel casing 14. In deep wells, regardless of whether the deep wells are oil or water, the packer may be positioned deep in the bore hole 10 to limit the volume of combustion required to achieve the pressure needed to create or extend the cracks. Reference to FIG. 2 illustrates a well bearing an alternate arrangement to achieve a fluid flow rate input under gaseous detonation. In this case, the well bore or bore hole 10 extends vertically through the earth 41 and through a petroleum bearing seam 43 to a point below the seam. Preferably two packers are set, one at 44 just below the oil bearing seam 43 and the other, 45, at some point above seam 43 but well below rig 42. It is the volume of the portion of bore 40, between the packers 44 and 45, which controls the extent of combustion reaction and the maximum pressure achieved within that portion of the bore hole. The packer 45 functions in addition to sealing off a portion of the bore hole 40, as the means for providing the oxidizer and fuel mixture under pressure via a tubing or piping similar to that of 20-21 of FIG. 1b, and the packer 45 further bears a spark plug and other elements of an ignition system for achieving sparking and thus ignition of the fuel oxidizer mixture within the portion of bore hole 40 segregated by packers 44 and 45.
Combustion is effected in the manner of the embodiment of FIGS. 1a, 1b.
Turning next to FIG. 4, the method of the present invention involves a slight modification in which two packers are provided to a well bore hole as at 40' within an earth formation 41' with the bore hole 40' terminating just below a petroleum formation 43'. In this case, an upper or top packer 51 receives reactants which pass through the top packer 51 via a supply tube 52 under pressure, as indicated by the arrow, the combustible mixture filling the space 55 between upper or top packer 51 or a lower or bottom packer 50. The lower packer 50 takes the form of a check valve including a ball valve member 50a which is borne within a larger diameter axial passage portion 50c within plate 50d. The ball 50a is prevented from falling into the bore hole by a perforated screen as at 50b. The ball 50a has a diameter slightly larger than passage portion 50e which is open to a larger diameter passage portion 50c. The packer 51 is provided with a spark plug as at 53 corresponding to spark plug 22 of the embodiment of FIG. 1b. Electrical current is applied via line 54 to spark plug 22. While pressurization occurs in bore chamber portion or volume 55 as well as the lower bore hole portion or chamber 56, beneath packer 50, the ignition of the fuel and oxidizer mixture in gaseous form in the vicinity of the spark plug 53 causes a pressure wave in the combustion volume, captured between the packers 50 and 51, to pass through the check valve, thus raising the pressure in the petroleum formation 43'. Multiple firings are used to raise this pressure to very high value with the pressure within volume 56 being much greater than the residual pressure value within volume 55. In this way, a steady pressure may be imposed upon the petroleum bearing rock, in place of pulse pressure rises. For multiple firings, means must be provided to remove the products of combustion of each firing, replacing them with fresh reactants. Such means would normally involve the piping or tube 52 leading to volume 55. Obviously, for all embodiments, the tube 52 may be sealed off to the source of the combustible mixture prior to ignition of the confined and sealed volume in chambers such as 55 and 24 for embodiments of FIG. 4 and FIG. 1b, respectively.
As may be appreciated, the invention has application to a drilled well or even a natural well, and references to terms such as well bore or bore hole are not intended to be limited to a hole within an earth formation achieved through conventional drilling techniques to effect creation of a vertical or inclined bore hole.
While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.
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A portion of an earth well bore is sealed off, and a combustible mixture of gaseous oxidizer and fuel is introduced into a sealed length of the well bore and ignited with substantial momentary pressure rise, fracturing the earth formation adjacent the well bore to increase the flow of fluid from the surrounding earth into the well. A check valve intermediate of the sealed well bore length functions to segregate the well bore into upper and lower sealed portions. By igniting a fuel gas mixture within the first sealed length, there is created a momentary high pressure wave within the sealed volume that is transmitted as a standing pressure into the second sealed volume. Successive firings of combustible mixtures in the first sealed volume create a steady pressure in the second sealed volume nearly equivalent to the peak transitory pressures realized in the first sealed volume during the individual firings.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a steel cord for the reinforcement of rubber articles comprising a core consisting of two to four steel filaments, and one layer of steel filaments around the core. The layer consists of filaments which face two filaments of the core and which form an inner-sheath, and of filaments which face only one filament of said core and which form an outer-sheath. All these filaments are twisted in the same direction and at the same pitch.
2. Description of the Related Art
A steel cord for the reinforcement of rubber articles conveniently comprises steel filaments having a carbon content of more than 0.60 per cent by weight (e.g. more than 0.65% 0.78%, 0.82% or 0.90%). A typical steel composition is:a minimum carbon content above 0.65% a manganese content between 0.40% and 0.70%, a silicon content between 0.15% and 0.30% and a maximum sulphur and maximum phosphorus content of 0.03%, all percentages being percentages by weight. Other elements such as chromium or boron or vanadium may also be alloyed.
The diameter of such steel filaments lies in the range of 0.05 mm to 0.80 mm, preferably in the range of 0.15 mm to 0.40 mm (e.g. 0.23 mm, 0.26 mm or 0.32 mm).
The steel filaments are usually provided with a coating which promotes the adherence of steel wire to rubber articles.
Such a coating conveniently comprises copper, zinc, brass or ternary brass alloy, or a combination of two or more different layers thereof. The thickness of the coating ranges from 0.05 to 0.40 micron, preferably from 0.12 to 0.22 micron. The coating may also be present in the form of a thin film of chemical primer material for ensuring good rubber penetration and adhesion.
A steel cord with all the filaments - except for the wrapping filament--twisted in the same direction with the same twist pitch is disclosed e.g. in GB-A-2 028 393 and is know as a compact cord.
Advantages of such a steel cord are its economical way of manufacturing (in one step), its compact form which allows much steel per cross-sectional surface unit and its line contacts.
Such a steel cord, however, suffers from fretting wear between the filaments of the layer and from core migration, i.e. the filaments of the core slips out of the cord due to repeated bends.
The prior art has already provided several solutions for avoiding core migration.
First of all, core migration may be avoided by differing the twist pitch of the filaments of the core substantially from the twist pitch of filaments of the layer and by increasing the diameter of the core filaments with respect to the diameter of the layer (U.S.-A-4,627,229).
In U.S.-A-4,783,955 another solution is proposed. The diameter of the core filaments is increased with respect to the diameter of the filaments of the layer while the twist pitch of the core filaments remains the same as the twist of the filaments of the layer.
The latter solution is based on the reasoning that in order to avoid core migration two measures must be taken:
1. the filaments of the layer must apply a tightening force to the core filaments, and
2. rubber must sufficiently penetrate into the inside of the cord.
SUMMARY OF THE INVENTION
The present inventors, however, have discovered that only the second measure, sufficient rubber penetration, is necessary, the first measure resulting only in secondary effects. This discovery has led to an alternative construction where core migration is as well avoided as in the prior art. This alternative steel cord construction is the subject of the present application.
According to the present invention there is provided a steel cord for the reinforcement of rubber articles. The steel cord comprises a core, consisting of two to four steel filaments and a layer of steel filaments around said core. All the filaments have a diameter between 0.15 and 0.40 mm and are twisted in the same direction and at the same pitch. The cord has substantially over its entire length cross-sections which present gaps between adjacent filaments of the layer. The accumulated gaps are at least 0.03 mm. At least one filament of the layer has been preformed substantially differently from the other filaments.
By "substantially over its entire length" it is meant that there may be, occasionally, some cross-sections where the accumulated gaps are less than 0.03 mm. However, such a cross-section is preceded and followed by cross-sections where the accumulated gaps are at least 0.03 mm.
By "gap" between adjacent filaments it is meant the minimum distance between the filaments.
By "accumulated gaps" it is meant the sum of all the gaps over the circumference of the layer. The accumulated gaps must be at least 0.03 mm in order to allow sufficient rubber to penetrate to the inside of the cord. If the accumulated gaps are less than 0.03 mm then the chances for core migration increase.
Preforming as such is widely known in the art of steel cord manufacturing. Appropriate preforming of at least one filament of the layer "creates" - together with the possible difference in diameters between the core filaments and the layer filaments--the gaps in the layer and, consequently, promotes rubber penetration.
The extent of preforming may be characterized by the preforming ratio. The preforming ratio of a filament is the outer diameter of the helicoid formed by this filament when taken out of the cord divided by the diameter of the cord. The greater the preforming ratio the more remote are the filaments from the centre of the cord.
A filament of the layer has been preformed substantially different from the other filaments of the layer if its preforming ratio is at least four per cent (4%) greater than the greatest preforming ratio this filament could have while still having line contacts with the neighboring filaments of the core.
The advantage of the present invention that filaments with different diameters no longer have to be used and that all the drawbacks associated with this use of different diameters such as wrong filament location or position changes of filaments are avoided.
If, nevertheless, the diameter of the filaments of the core is greater than the diameter of all or some filaments of the layer, then the preforming of one or more filaments oil the layer further facilitates rubber penetration and further decreases the chances for core migration.
In a preferable embodiment of the present invention only the filaments of the inner-sheath have been preformed differently from the other filaments. This embodiment has the advantage that the necessary gaps may be created without increasing the diameter of the cord (it is hereby understood that for a given tensile strength small cord diameters are appreciated in the tire manufacturing industry because small cord diameters lead to thin rubber plies).
If the cord has three or four core filaments and at least one of these core filaments has been preformed differently, from the other core filaments then gaps may be created between the core filaments so that rubber may even penetrate to the inside of the core. Although this feature is not necessary for avoiding core migration it has the advantage of higher corrosion fatigue resistance since the central void between the core filaments is avoided.
The steel cord according to the invention may or may not be provided with an additional single steel filament which is wrapped around the steel cord.
The steel cord according to the present invention is preferably used as a reinforcement of the belt area and/or carcass area of tires.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be further explained and illustrated by means of a number of drawings in which
FIG. 1 and FIG. 2 show cross-sections of prior art steel cord constructions;
FIG. 3 shows a cross-section of a steel cord construction according to the present invention;
FIG. 4a shows an apparatus to manufacture a cord according to the present invention;
FIG. 4b shows the subsequent cross-section of a cord during its manufacturing process; and
FIG. 5 shows a cross-section of another steel cord construction according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the cross section of a prior art 12×1 compact cord 1. The core consists of three filaments 2. In the layer the inner-sheath consists of three filaments 3 and the outer-sheath consists of six filaments 4.
All these filaments 2-3-4 have an equal diameter, e.g. 0.22 mm. The steel cord is wrapped around by a single filament S. As may be easily seen on FIG. 1, the layer has no gaps so that rubber cannot penetrate into the inside of the cord 1.
FIG. 2 shows the cross section of another prior art 12×1 compact cord 1. The difference with the embodiment of FIG. 1 is that the diameter of the filaments 2 of the core is greater than the diameter of the filaments 3-4 of the layer, e.g. 0.22 mm core filament diameter versus 0.20 mm core filament diameter. Due to this difference in diameter the layer has three gaps δ1, δ2 and δ3, which allow rubber to penetrate and adhere to the surface of the core filaments 2 to the extent represented by the thickened line of FIG. 2.
FIG. 3 shows a cross-section of a steel cord 1 according to the present invention. The diameter of all the filaments is the same. The three filaments 3 of the inner-sheath have been preformed and occupy the place represented by full lines. If these filaments 3 were not preformed they would occupy the place represented by broken lines.
Due to the preforming the cross-section of filaments 3 oscillate over the entire length of the cord 1 between the position represented by broken lines and a position which is more remote from the centre of the cord. Dependent on the particular way of preforming and on the way of manufacturing the cord this oscillation may be planar or spatial. Due to this preforming, six gaps δ1, δ2, δ3, δ4, δ5 and δ6 are created and allow rubber to penetrate and to adhere to the surface of the core filaments 2 to the extent represented by the thickened line 21.
Comparing FIG. 3 with FIG. 2 it may be easily seen that the surface 21 which may be adhered to by rubber is much larger in the case of the invention than in the case of the prior art. This means that the steel cord according to the invention has less chance for core migration.
Since in FIG. 3 only the filaments 3 of the inner-sheath have been preformed, the diameter of the cord is not necessarily increased with respect to a prior art compact cord without preformed filaments.
A supplementary advantage of the steel cord according to the present invention is that a wrapping filament 5--if present--is supported by all the filaments 3-4 of inner-sheath and outer-sheath whereas for the prior art compact structures the wrapping filament 5 is only supported by the filaments 4 of the outer-sheath thereby "bridging" the filaments 3. A more uniform support for the wrapping filament 5 reduces the fretting wear of this filament.
A process for manufacturing the steel cord according to the present invention is illustrated in FIG. 4a.
Core filaments 2 are centrally led to a well known double twisting machine (not shown). Filaments 3 of the inner-sheath are guided through the holes 71 of a distributing disc 7 and further over the edge of a disc 8 where the layer filaments 3 form an angle and where they receive the necessary preforming.
It is to be understood that due to the effect of the downstream double twister the filaments 3 rotate around their own axis while they are rotating with the same rotation speed around the circumference of disc 8 so that this preforming operation will result in a planar oscillation of filaments 3. The preforming degree may be tuned by adjusting the distance between the distributing disc 7 and the disc 8 by means of a threaded body 81, which is connected to the disc 8:the greater the distance between the disc 7 and the disc 8 the greater the preforming ratio of filaments 3. The preforming ratio of a filament is the diameter of the helicoid formed by this filament when taken out of the cord divided by the diameter of the cord. The greater the preforming ratio the more remote the filaments are from the center of the cord.
Following this preforming the filaments 3 of the inner-sheath come together with the core filaments 2 at a guiding hole 9 (see FIG. 4b). They are further led through a central hole 101 of a distributing disc 10. The other filament 4 are also led through holes 101 of distributing disc 10 and join the filaments 3 at cabling disc 11 (see FIG. 4b).
FIG. 5 shows a cross-section of a steel cord according to the present invention where one of the core filaments 2 has been preformed differently from the the core filaments. Gaps are created between the core filaments so that rubber may penetrate to the inside of the core.
Different properties of two prior art steel cord constructions are now compared with a steel cord according to the present invention.
Prior art cord nr 1 is a normal compact cord 12×1 with all filament diameters equal to 0.22 mm and with no filament subjected to a special preforming treatment.
Prior art cord nr 2 is compact cord the core filaments 2 of which have a diameter of 0.22 mm and the layer filaments 3-4 of which have a diameter of 0.20 mm.
The steel cord according to the present invention has filaments with all the same diameter 0.22 mm, among which the three filaments 3 of the inner-sheath have been subjected to a preforming treatment as described in relation with FIGS. 4a and 4b.
The breaking load has been determined by a tension test. The fatigue strength has been determined by the well known Hunter test.
The rubber penetration is determined by measuring the amount of air passing through a rubber block (224 mm long, 15 mm high, and 265 mm wide), in which four identical steel cord constructions are embedded at 4 bar air pressure difference. The lesser amount of air passing the greater the rubber penetration.
In order to determine whether there is core migration or not the steel cord is embedded in a rubber cylinder and this cylinder is then subjected to a number of repeated bendings.
If the core filaments 2 slip out of the cord there is core migration, in the opposite case there is no core migration. The accumulated gaps are measured manually on an enlarged photo of a number of cross-sections taken along the length a cord. The average value is mentioned in the table.
Most of the above-cited tests are described more in detail in the paper by Bourgois Luc, "Survey of Mechanical Properties of Steel Cord and Related Test Methods", Tire Reinforcement and Tire Performance, ASTM STP 694, R. A. Fleming an D. I. Livingston, Eds., American Society for Testing and Materials, 1979, pp. 19-46.
TABLE______________________________________ PRIOR ART INVENTION 2 12 × 0.22 1 3 × 0.22 + inner-sheath 12 × 0.22 cc 9 × 0.20 cc preformed______________________________________diameter (mm) 1.16 1.09 1.16breaking load (N) 1310 1223 1310elongation (%) 2.74 2.73 3.01fatigue strength 950 1050 900(embedded)(N/mm.sup.2)rubber penetration 8.7 2.0 3.3(l/H)core migration yes no noadhesion 645 676 656accumulated gaps 0 0.12 0.04(mm)______________________________________ cc = compact cord
As may be derived from the table, core migration is avoided in the cord according to the invention as in prior art cord 2, despite the fact that the accumulated gaps in the invention cord are much smaller (0.04) than in prior art cord 2 (0.12).
FIG. 6 shows a tire 23 having a carcass 25 and a belt area 27. The belt area 27 is reinforced with the steel cord 1. Likewise, the carcass 25 may also be reinforced with the steel cord 1.
It is to be understood that the invention is not limited to compact cord constructions comprising only one layer around the core, but that it may also be applied to constructions compressing more coaxial layers around the core. Proper preforming of filaments of the radially most inner layer causes the global cross-sectional circumference to be greater than in a normal compact configuration, which makes that the filaments of the radially outer layer do not longer make contact with each other and allow rubber to penetrate to the core filaments.
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A steel cord (1) for the reinforcement of rubber articles such as tires includes a core of two to four steel filaments (2) and a layer of steel filaments (3, 4) around the core. All of the filaments have a diameter between 0.15 and 0.40 mm and are twisted in the same direction and at the same pitch. The cord has over a substantial portion of its entire length cross-sections where the accumulated gaps between adjacent layer filaments are at least 0.03 mm. At least one filament of the layer has been preformed differently from the other filaments. The above structure avoids core migration.
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FIELD OF THE INVENTION
The present invention relates to fluid compositions which exhibit substantial changes in rheological properties when exposed to electric fields. More specifically, the present invention relates to an electrorheological material which utilizes an anionic surfactant as the active particle component.
BACKGROUND OF THE INVENTION
Electrorheological materials are fluid compositions which exhibit substantial changes in rheological properties in the presence of an electric field. Electrorheological materials typically consist of (1) a carrier fluid, (2) a particle component, (3) an activator, and (4) a surfactant. The surfactant of the electrorheological material is utilized to disperse the particle component within the carrier fluid while the activator is utilized to impart electroactivity to the particle component. In the presence of an electric field, the particle component becomes organized so as to increase the apparent viscosity or flow resistance of the overall fluid. Therefore, by manipulating the electric field, one can selectively change the apparent viscosity or flow resistance of an electrorheological material to achieve desired results in various known devices and applications.
In the absence of an electric field, electrorheological materials exhibit approximately Newtonian behavior; specifically, their shear stress (applied force per unit area) is directly proportional to the shear rate (relative velocity per unit thickness). When an electric field is applied, a yield stress phenomenon appears and no shearing takes place until the shear stress exceeds a yield value which rises with increasing electric field strength. This phenomenon can appear as an increase in apparent viscosity of several, and indeed many, order of magnitude.
The mechanism responsible for the observed behavior of electrorheological materials is believed to be an induced polarization of the particle component (particles) followed by a mutual interaction of the polarized particles to form a filamentary structure. In general, the particles in an electrorheological material are able to polarize due to internal or surface conductivity which leads to Maxwell-Wagner polarization when an external field is applied. Although polarization can also occur due to electronic or atomic distortions and the orientation of molecular dipoles, i.e. the real part of the dielectric constant, conduction and subsequent Maxwell-Wagner polarization will dominate at low frequency.
Induced polarization in most electrorheological materials, particularly the so called "water-activated" materials is due to ionic conduction. Adsorbed water on the surface of these particles form an electrolyte with Ca or an alkali metal such as Na, K or Li which are generally present as impurities or are added on purpose to form mobile cations. These cations move through the pores and along the surface of the particles under the influence of an external field to form induced dipoles. An activator such as water is required by these electrorheological materials in order to solvate the cations. If the activator is removed, the ions are no longer mobile and polarization can no longer occur or occurs so slowly that little electrorheological effect is observed. The activator for these materials can also be solvents or molecules containing an amine or an alcohol functionality such as ethylene glycol, diethylamine or acetamide such as is discussed in U.S. Pat. No. 3,427,247 and Matsepuro, "Structure Formation in an Electric Field and the Composition of Electrorheological Suspensions," Royal Aircraft Establishment Library Translation 2110, July 1983.
For electrorheological materials in general, a higher volume fraction of particle component affords a higher induced yield stress and the relationship between induced yield stress and volume fraction has been found to be approximately linear for volume fractions up to about 50%. Volume fractions greater than 50% are generally not used since the materials become very strongly dilatant above this point. Above a 50% volume fraction the zero-field viscosity and zero-field yield stress increases so rapidly that the proportional change in stress due to the applied electric field is actually less than that obtained for a volume fraction less than 50%.
Particle size has little influence on the magnitude of the electrorheological effect as long as the particles have a diameter more or less within the range of 0.1 to 100 microns. Particles smaller than this range may show a decreased effect due to competition from thermal effects, e.g. Brownian motion, which tends to inhibit formation of particle chains when the electric field induced particle-particle interaction energy is less than or on the same order as the thermal energy kT/2. Particles larger than the above range will continue to exhibit an electrorheological effect; however, they become increasingly difficult to maintain in suspension and are subject to jamming and filter cake packing, i.e. the particles chain but the continuous phase liquid continues to move between them. These effects are minimized by keeping the particle small enough such that the Stokes drag forces experienced by a particle are of the same order as the electric field induced forces.
At a fixed electric field strength, the shear stress of electrorheological materials generally increases linearly with shear rate. The rate of stress increase with increasing shear rate is the plastic viscosity of the electrorheological material. The plastic viscosity is, in general, equal to the zero-field or Newtonian viscosity of the electrorheological material.
Many different types of specific electrorheological materials have been previously developed in an attempt to optimize the parameters and properties discussed above. For example, an electrorheological material utilizing silica gel as the particle component and electrically stable dielectric oily vehicles such as white oils and transformer oils as the carrier fluid is disclosed in U.S. Pat. No. 2,661,596. Water is used as the activator while various dispersing agents such as sorbitol sesquioleate, ferrous oleate, sodium oleate, and sodium naphthenate are utilized as surfactants. Similarly, U.S. Pat. No. 2,661,825 discloses an electrorheological material which utilizes carbonile iron powder or silica gel as the particle component and mineral oil or kerosene as the carrier fluid. Various activators mentioned include water, ethylene glycol, and mono ethyl ether while surfactants utilized include aluminum stearates, lithium stearate, lithium rasinoleate, sorbitol sesquioleate, and lauryl peridinium chloride.
An electrorheological material composed of a non-conductive solid particle component dispersed within an oleaginous carrier fluid is described in U.S. Pat. No. 3,047,507. The compositions utilize as an activator a minimum amount of water and utilize as a surfactant various anionic and cationic surface active agents such as fatty acids, naphthenic acids, resinic acids, various salts of these acids, and primary amines. Also, U.S. Pat. No. 3,367,872 discloses an electrorheological material which utilizes alumina or silica alumina as the particle component and an oleaginous vehicle as the carrier fluid. Water is described as the activator and various anionic and cationic agents such as alkyl aryl sulfonates, sulfated alcohols, oleyl alcohol sulfates, lauryl alcohol sulfates, various sodium alkyl sulfates, quaternary ammonium salts, and salts of higher alkyl amines are described as surfactants.
Traditional electrorheological materials such as the materials described above require both a particle component and a surfactant in order to perform effectively in various applications. It would be desirable to eliminate the need for both a particle component and a surfactant in present electrorheological materials.
Turning to more specific applications, in order to fulfill their potential as a unique interface between electronic controls and mechanical systems, appropriate electrorheological materials must demonstrate certain practical characteristics. For example, in certain applications an electrorheological material should be miscible with water to facilitate handling of the material and cleaning of mechanical systems containing the material. Also, in applications involving mechanical components or objects having delicate surfaces, the dispersed phase particles should be non-abrasive. As would be expected, the chemical nature of the carrier fluid, the particle component, and any resulting combination should be compatible with the mechanical materials used to produce the electrorheological device.
One particular group of applications in which it is desirable that electrorheological materials exhibit miscibility with water are fixturing and chucking applications in which electrorheological materials are used to hold or secure an object firmly in place so that it may be machined, measured, gauged or otherwise inspected. Examples of such electrorheological material-based chucking devices are disclosed in U.S. Pat. Nos. 3,197,682 and 3,253,200. One problematic aspect of such devices is that the object to be held is placed in contact with the electrorheological material and after the chucking process is complete an undesirable residue of electrorheological material remains on the surface of the object. This residue is generally oily in nature and may often be pigmented depending on the nature of the dispersed phase. Cleaning of the object after the chucking process is a problem with normal electrorheological materials such as silicates in silicone oil or pigmented fluids. Any advantage incurred by the electrorheological material chucking device may be lost due to the additional time required to clean the part.
It is also important to utilize a non-abrasive particle component in such chucking device applications as well as in other applications such as clutching devices in order to avoid scratching or marring of any object or component surface. Non-abrasive dispersed phase particles are particularly desirable in chucking applications involving parts having a delicate surface finish.
Therefore, it would be desirable to create electrorheological materials which are miscible with water and yet which are physically, mechanically, and chemically compatible with applied systems.
SUMMARY OF THE INVENTION
The present invention is an electrorheological material which eliminates the need for both a particle component and a surfactant and which is uniquely compatible with certain applied systesms. The present electrorheological material is exceptionally well suited for use in chucking device applications or other mechanical systems requiring frequent cleaning since the material is essentially self-cleaning due to its miscibility with water and is based on a soft, non-abrasive particle component that will not mar delicate surfaces.
It has presently been discovered that certain anionic surfactant compositions will function as both the particle component and surfactant of an electrorheological material. More specifically, the present invention comprises an electrically insulating hydrophobic liquid as the carrier fluid, an anionic surfactant as the particle component, and water or other molecule containing hydroxyl, carboxyl or amine functionality as the activator. The anionic surfactant acts as both the particle component and surfactant and therefore no additional surfactant is needed for the material of the present invention. The present non-abrasive electrorheological material is also miscible with water so as to facilitate cleaning and exhibits sufficient electrorheological activity to be useful in known electrorheological devices.
It is therefore an object of the present invention to provide an electrorheological material which eliminates the need for both a particle component and a surfactant.
It is another object of the present invention to provide an electrorheological material which will demonstrate appropriate electrorheological capabilities and improved handling characteristics that facilitate the cleaning of mechanical systems containing the material.
It is still another object of the present invention to provide an electrorheological material which exhibits appropriate electrorheological capabilities and is miscible with water.
It is yet another object of the present invention to provide an electrorheological material which utilizes a soft, non-abrasive material as the particle component.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to an electrorheological material comprising a carrier fluid, a particle component, and an activator wherein the particle component is a non-abrasive, water-soluble anionic surfactant which behaves as both an electrorheological particle and a dispersing agent.
The carrier fluid of the invention is a continuous liquid phase and may be selected from any of a large number of electrically insulating, hydrophobic liquids known for use in electrorheological materials. Typical liquids useful in the present invention include mineral oils, white oils, paraffin oils, chlorinated hydrocarbons such as 1-chlorotetradecane, silicone oils, transformer oils, halogenated aromatic liquids, halogenated paraffins, polyoxyalkylenes, fluorinated hydrocarbons and mixtures thereof. Silicone oils having viscosities of between about 0.65 and 1000 milli Pascal seconds (mPa·s) are the preferred carrier fluids of the invention. As known to those familiar with such compounds, transformer oils refer to those liquids having characteristic properties of both electrical and thermal insulation. Naturally occurring transformer oils include refined mineral oils which have low viscosity and high chemical stability. Synthetic transformer oils generaly comprise chlorinated aromatics (chlorinated biphenyls and trichlorobenzene) which are known collectively as "askarels", silicone oils, and esteric liquids such as dibutyl sebacates. The carrier fluid is utilized in an amount from about 50 to about 90, preferably from about 55 to about 70 percent by weight of the final electrorheological material.
The particle component of the present invention can essentially be any known anionic surfactant. Preferred are anionic surfactants containing a long lipophilic tail bonded to a water-soluble (hydrophilic) group at the other end. In solution, an anionic surfactant ionizes in such a way that the hydrophilic group carries a negative charge. A cation, which is typically sodium but can also be one of the other alkali metals or ammonium, is attracted to the negative charge and can move under the influence of an applied electric field to polarize the particle. The lipophilic tail is preferably an alkyl group typically having from about 8 to 21 carbon atoms.
Typical anionic surfactants include carboxylic acid salts such as fatty acid salts having the formula R 1 COOR 2 wherein R 1 is a straight chain, saturated or unsaturated, hydrocarbon radical of 8 to 21 carbon atoms and R 2 is a base-forming radical such as Li, Na, K or NH 4 which makes the detergent-like surfactant soluble in water. Typical fatty acid salts include sodium stearate, sodium palmitate, ammonium oleate, and triethanolamine palmitate. Additional carboxylic acid salts useful as anionic surfactants of the invention include sodium and potassium salts of coconut oil fatty acids and tall oil acids as well as other carboxylic acid salt compounds including amine salts such as triethanolamine salts, acylated polypeptides and salts of N-lauroyl sarcosine such as N-dodecanoyl-N-methylglycine sodium salt.
Other anionic surfactants useful in the present invention include aryl and alkyl aryl sulfonates such as alkylbenzene sulfonate, linear alkylbenzene sulfonates, sodium tetrapropylene benzene sulfonate, sodium dodecylbenzene sulfonate, benzene-, toluene-, xylene- and cumenesulfonates; ligninsulfonates; petroleum sulfonates; paraffin sulfonates; secondary n-alkane-sulfonates; α-olefin sulfonates; alkylnapthalene sulfonates, n-acyl-n-alkyltaurates; sulfosuccinate esters; isethionates; alkyl sulfates having the formula R 1 OSO 3 R 2 wherein R 1 and R 2 are as defined above, such as lithium dodecyl sulfate, sodium dodecyl sulfate, potassium dodecyl sulfate, and sodium tetradecyl sulfate; alkyl sulfonates having the formula R 1 SO 3 R 2 wherein R 1 and R 2 are as defined above, such as sodium lauryl sulfonate; sulfated and sulfonated amides and amines; sulfated and sulfonated esters such as lauric monoglyceride sodium sulfate, sodium sulphoethyl oleate, and sodium lauryl sulphoacetate; sulfuric acid ester salts such as sulfated linear primary alcohols, sulfated polyoxyethylenated straight-chain alcohols and sulfated triglyceride oils; phosphoric and polyphosphoric acid esters; perfluorinated carboxylic acids; and polymeric anionic surfactants such as alginic acid. These and other anionic surfactants are discussed in Rosen, "Surfactants and Interfacial Phenomena," John Wiley & Sons, pp. 7-16, 1989. Mixtures or combinations of anionic surfactants may also be utilized as the particle component. Sodium dodecyl sulfate is the presently preferred anionic surfactant for use in the present invention.
The particle component typically comprises from about 10 to about 50, preferably from about 30 to about 45, percent by weight of the total electrorheological material depending on the specific particle being used, the desired electroactivity and the viscosity of the overall fluid. The particular amount of particle component required in individual materials will be apparent to those skilled in the art.
A small amount of activator is required for the present electrorheological material to exhibit proper electrorheological activity. Typical activators for use in the present invention include water and other molecules containing hydroxyl, carboxyl or amine functionality. Typical activators other than water include methyl, ethyl, propyl, isopropyl, butyl and hexyl alcohols, ethylene glycol, diethylene glycol, propylene glycol, glycerol; formic, acetic and lactic acids; aliphatic, aromatic and heterocyclic amines, including primary, secondary and tertiary amino alcohols and amino esters which have from 1-16 atoms of carbon in the molecule; methyl, butyl, octyl, dodecyl, hexadecyl, diethyl, diisopropyl and dibutyl amines, ethanolamine, propanolamine, ethoxyethylamine, dioctylomine, triethylamine, trimethylomine, tributylamine, ethylenediamine, propylene-diamine, triethanolamine, triethylenetetramine, pyridine, morpholine and imidazole; and mixtures thereof. Water is the preferred activator for use in the present invention. The activator is utilized in an amount from about 0.1 to about 10, preferably from about 0.5 to about 5.0, percent by weight relative to the weight of the particle component.
An additional surfactant to further disperse the particle component may also be utilized in the present invention. Such surfactants include known surfactants or dispersing agents such as the ionic surfactants discussed in U.S. Pat. No. 3,047,507 (incorporated herein by reference) but preferably comprise non-ionic surfactants such as the steric stabilizing amino-functional, hydroxy-functional, acetoxy-functional, or alkoxy-functional polysiloxanes such as those disclosed in U.S. Pat. No. 4,645,614 (incorporated herein by reference). Other steric stabilizers such as graft and block copolymers may be utilized as an additional surfactant for the present invention and such other steric stabilizers as, for example, block copolymers of poly(ethylene oxide) and poly(propylene oxide) are disclosed in detail in U.S. Pat. No. 4,772,407 (incorporated herein by reference) and in Napper, "Polymeric Stabilization of Colloidal Dispersions," Academic Press, London, 1983. The additional surfactant, if utilized, is preferably an amino-functional polydimethylsiloxane. The additional surfactant is typically utilized in an amount from about 0.1 to about 10 percent by weight relative to the weight of the particle component.
The electrorheological materials of the present invention can be prepared by simply mixing together the carrier fluid, the particle component and the activator. If water is used as an activator, the corresponding electrorheological material is preferably prepared by drying the particle component in a convection oven at a temperature of from about 110° C. to about 150° C. for a period of time from about 3 hours to about 24 hours and subsequently allowing the particle component to absorb the desired amount of water from the atmosphere. The ingredients of the electrorheological materials may be initially mixed together by hand with a spatula or the like and then subsequently more thoroughly mixed with a mechanical mixer or shaker.
Evaluation of the properties and characteristics of the electrorheological materials of the present invention, as well as other electrorheological materials, can be carried out by directing the fluids through a defined channel, the sides of which form parallel electrodes with definite spacing therebetween. A pressure transducer measures the pressure drop between the entry and exit ends of the flow channel as a function of applied voltage. By keeping flow rates low, the viscous contribution to the pressure drop is kept negligible. Induced yield stress (T) is calculated according to the following formula:
T=dp(B/2L)
where dp represents the pressure drop, L is the length of the channel and B is the electrode spacing. The numerical constant 2 is generally valid for the normally encountered ranges of flow rates, viscosities, yield stresses and flow channel sizes. In its strictest sense, this constant can have a value between 2 and 3, a detailed discussion of which is given in R. W. Phillips "Engineering Applications of Fluids With a Variable Yield Stress," Ph. D. Thesis, University of California, Berkley, 1969.
The following examples are given to illustrate the invention and should not be construed to limit the scope of the invention.
EXAMPLE 1
To a Thermolyne convection oven maintained a temperature of 116° C. was added 70 g of sodium dodecyl sulfate obtained from Sigma Chemical Company. The sodium dodecyl sulfate was dried for a period of 24 hours in the convection oven and then allowed to absorb 0.35 g of water from the atmosphere. The water activated sodium dodecyl sulfate was added to 100 g of 10 mPa·s silicone oil obtained from Union Carbide Corporation. The ingredients were thoroughly mixed with a spatula and then vigorously shaken with a Red Devil mechanical shaker.
EXAMPLE 2
An electrorheological material was prepared according to the method disclosed in Example 1 except that 20 g of N-dodecanoyl-N-methylglycine sodium salt was utilized as the particle component which was activated with 0.5 g of water.
EXAMPLE 3
An electrorheological material was prepared according to the method disclosed in Example 1 except that 40 g of lithium dodecyl sulfate was utilized as the particle component which was activated with 0.4 g of water.
EXAMPLE 4
An electrorheological material was prepared according to the method disclosed in Example 1 except that 70 g of sodium dodecylbenzenesulfonate was utilized as the particle component which was activated with 1.7 g of water.
EXAMPLE 5
An electrorheological material was prepared according to the method disclosed in Example 1 except that 70 g of alginic acid sodium salt was utilized as the particle component which was activated with 2.1 g of water.
ELECTRORHEOLOGICAL ACTIVITY
Each of the electrorheological materials prepared in Examples 1-5 were tested for electrorheological activity and the results are indicated in Table 1 below.
TABLE 1*______________________________________Example # Electric Field (kV/mm) Yield Stress (Pa)______________________________________1 4.5 4303 4.0 410______________________________________ *Examples 2, 4, and 5 exhibited a significant electrorheological effect when exposed to an electrical probe operated at 1.0 kV/mm.
It is understood that the foregoing is a description of the preferred embodiments of the present invention and that the scope of the invention is not limited to the specific terms and conditions set forth above but is determined by the following claims.
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An electrorheological material containing a carrier fluid, an anionic surfactant particle component, and an activator. The non-abrasive anionic surfactant acts as both a particle component and a surfactant and the electrorheological material is miscible with water and will not mar the surface of objects utilized in an electrorheological device.
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FIELD OF THE INVENTION
The invention relates generally to the field of security printing and, more particularly, to a computer-generated printed security device comprising microscopic characters, group(s) of which are phase shifted relative to others so as to form a latent image which is macroscopically viewable with the aid of a finding screen.
BACKGROUND
The printing of latent images per se, for purposes of security or authentication, is known. For example, Canadian Patent No. 1,172,282 to Trevor Merry provides a security device comprising overlying line deflection patterns which produce different macroscopically viewable images when overlain at different positions by a finding screen. The latent image disclosed by the said Canadian patent is comprised of parallel lines, portions of which are deflected a predetermined distance in the area of the latent image to define the same. The lines are, of course, readily visible and do not themselves provide any additional security feature apart from the latent image. Thus, in order to increase the level of security provided by such a security device it was previously necessary to combine a separate security feature with the device, thereby adding printing or embossing steps to the overall process for producing the desired security document.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a security device, and method for producing the same, which itself provides two distinct security features, one at a microscopic level and the other at a macroscopic level. The security device comprises a substrate having applied thereto an array of characters. The characters are of a sufficiently small size as to appear uniform when ordinarily viewed but individually identifiable when viewed with the aid of appropriate magnification means. Group(s) of said characters are phase-shifted relative to the others in such a manner as to collectively define a latent image, the image being relatively indiscernible when the device is ordinarily viewed but discernible when viewed with the aid of a finding screen.
Preferably the array of characters comprises a plurality of lines of alphanumeric characters. The characters preferably occupy an area of less than, 0.2 square millimetres and have a density in the range of 1-3 character lines per millimeter.
Use of a dark background and light characters may be preferred. Preferably the application of the array of characters includes the use of a computer to generate the array.
SUMMARY OF THE DRAWINGS
The invention is described below with reference to the following drawings:
FIG. 1 is an enlarged illustration of a micro character array in accordance with the invention (The individual characters of the repeated message "Canadian Bank Note Microplex" actually occupying a space of about 0.18 mm square).
FIG. 2 is an illustration of another example of a micro character array in accordance with the invention (again, the individual characters actually occupying a space of about 0.18 mm square).
FIG. 3 is an illustration of the arrays of FIGS. 1 and 2 interlaced such that the two macroscopic images defined thereby occupy alternating lines of the characters.
FIG. 4 is a illustration of the positioning of the macroscopic image "CBN" within a character array. (This figure has been enlarged and an outline of the macroscopic image has been superimposed on the character array in order to more clearly illustrate the invention).
FIG. 5 illustrates an alternate macroscopic image "MRP" in similar manner to that of FIG. 4.
FIG. 6 is an enlarged illustration of a micro character array in accordance with another embodiment of the invention, whereby a dark background surround light characters.
FIG. 7 is an enlarged illustration of a micro character array in accordance with another embodiment of the invention, whereby the characters and the backgrounds thereof alternate between white and black, respectively, for each successive line of characters.
FIG. 8 is a flow chart diagram of the steps which are performed by a computer to generate an array of micro characters, groups of which are phase shifted relative to the others to collectively form a macroscopic image.
DETAILED DESCRIPTION OF THE INVENTION
The invention is a security device comprising a pattern of microscopic characters, group(s) of which are phase-shifted relative to the others to collectively define a latent image which is macroscopically viewable with the aid of a finding screen such as a lenticular screen (described below). FIGS. 1 and 2 show examples of security devices in accordance with the invention; for purposes of illustration the printing of those figures has been substantially enlarged so that the microscopic characters may be readily viewed by the reader. However, in actuality the individual characters comprising the repeated message "CANADIAN BANK NOTE MICROPLEX" occupy a space of only about 0.18 mm square. The characters (which, alternatively, may make up any word, phrase or symbol) are spaced in lines or columns about 0.18 mm apart which results in a character density of about 2.75 character lines per millimeter. Generally, the characters preferably occupy an area of less than 0.2 mm square (i.e. 2 mm ×0.2 mm) and have a density in the range of 1-3 character lines per millimeter. Thus, the characters are not readily viewable and, at a macroscopic level, appear to be uniform non-distinct lines or other print elements. However, the individual characters are viewable with the aid of a microscope or suitable magnifying lens.
As illustrated by the drawings the micro characters (i.e. in the case of FIGS. 1 through 7, the letters comprising the character string "CANADIAN BANK NOTE MICROPLEX" are printed to form an array of rows (i.e. lines) and columns. Macroscopically, the character array appears generally uniform, particularly in the example shown by FIGS. 6 and 7 in which light characters appear within a dark background, but microscopically the alphanumeric characters are individually identifiable and able to convey meaningful information. Portions of the lines and columns comprising the characters are phase-shifted to collectively form larger characters or symbols, for example the letters "CBN" or "MRP" most clearly illustrated by FIGS. 4 and 5 respectively which are discernable only when the array is viewed through a finding screen. As described below, the pattern of the micro characters, including the phase-shifting, is most conveniently generated by a computer, as is the required pattern for the finding screen.
The characters (or groups of characters) are shifted above or below the centerline of the character string by a distance of about one half the character height (i.e. about 0.09 mm). This phase shifting of the individual pre-selected characters is pre-arranged to, collectively, define a message comprising a word or symbol at a macroscopic level. If desired, two sets of character strings may be independently phase-shifted to macroscopically define two distinct messages as shown by FIG. 3 of the drawings. The shifting of the characters is gradual, retaining a continuum of legible information across the boundary between the background and the macroscopically viewable image. By this means, the macroscopic image is not perceived without the assistance of the viewing screen, while at the macroscopic level, integrity of the individual characters and words is maintained.
FIG. 8 provides a flow chart of a sequence of steps which are performed by a computer to generate the character arrays of FIGS. 1 through 7. Of course, many program instruction sets might be developed on the basis of the flow-chart of FIG. 8 depending upon the selected computer and output device and the specific characters and messages to be produced thereby, which are not specific to the subject matter claimed herein.
Computer-generated imaging is well known in the security printing industry and does not, per se, form any aspect of the present invention. Such imaging method provides a convenient and practical means of implementing the invention by reason of the degree of precision and control provided thereby.
The preferred methods of printing the character array are intaglio and offset lithography according to the conventional and well-known procedures in the industry. Embossing printing methods may also be appropriate where the security device is required for, for example, aluminized foil lottery tickets or where plastic laminates are used to protect identification documents.
The latent image within the printed character array, according to the foregoing, is viewable by overlaying the array with a lenticular finding screen comprising a set of convex plano-cylindrical lenses having the same line (or column) frequency as the character strings. When the lenses are aligned parallel to the character strings, the latent image is viewed at a slightly different angle than the array due to refraction. To construct the line pattern of the plano-cylindrical lenses it is convenient to generate the same by means of a computer such that a set of computer generated lines having the same frequency as the character strings can be produced on photographic film. The lines are then etched through a photo sensitive resist into a suitable substrate such as copper using a solution of ferric chloride. Each line is reproduced as a concave depression in the copper with a maximum depth of 0.15 mm. After polishing the copper mould can be used to produce screens by heating a transparent plastic material such as PLEXIGLASS (trade-mark) under pressure against the mould. The plastic flows into the depressions forming a set of convex plano-cylindrical lenses raised above a base about 1 mm thick. It will be appreciated that other lens arrays having optical characteristics matched to specific character line frequencies can be readily generated by this means.
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A security device comprising a substrate having applied thereto an array of characters, the characters being of a sufficiently small size as to appear uniform when ordinarily viewed but individually identifiable when viewed with the aid of appropriate magnification means, whereby group(s) of the characters are phase-shifted relative to the others in such a manner as to collectively define an image, the image being relatively indiscernible when the device is ordinarily viewed but discernible when viewed with the aid of a finding screen.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a U.S. national stage of application No. PCT/JP2010/063167, filed on Apr. 8, 2010, 2010. Priority under 35 U.S.C. §119(a) and 35 U.S.C. §365(b) is claimed from Japanese Application No. 2009-186342, filed Aug. 11, 2009, the disclosure of which is also incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to an optical unit which is mounted on a cell phone with a camera or the like and its manufacturing method.
BACKGROUND
In recent years, a cell phone is structured as an optical device on which an optical unit for photographing is mounted. In the optical unit for photographing, in order to prevent disturbance of a photographed image due to a hand shake of a user, it has been proposed that a movable module provided with an optical element such as a lens is supported so as to be capable of being displaced with respect to a fixed body by a spring member and a movable module drive mechanism for correcting the hand shake is structured between the movable module and the fixed body for swinging the movable module (see Patent Literature 1).
Further, in the optical unit described in Patent Literature 1, the movable module includes an optical element unit provided with a lens and the like and a module cover holding the optical element unit and the module cover is formed with an opening part larger the optical element unit. According to this structure, after the module cover is supported by the fixed body through the spring member, the optical element unit is accommodated in the inside of the module cover and, after that, the optical element unit can be fixed in the inside of the module cover by an adhesive or welding. Therefore, the optical element unit provided with a lens and the like can be manufactured in a separated step from another mechanism.
[PTL 1] Japanese Patent Laid-Open No. 2007-41418
However, in the structure in which, after the optical element unit has been accommodated in the inside of the module cover, the optical element unit is fixed in the inside of the module cover by an adhesive or welding, the optical element unit inserted into the module cover is required to be held until the adhesion or the welding has been completed and thus considerable time and labor are required for assembling. Further, when the optical element unit is to be fixed in the inside of the module cover, the optical axis may be displaced.
The above-mentioned problems are not limited to the optical unit for photographing provided with the shake correction mechanism but are common to a general optical module in which the movable module is supported by the fixed body so as to be capable of being displaced.
SUMMARY
In view of the problems described above, at least an embodiment of the present invention provides an optical unit which is easily assembled and in which displacement of an optical axis is hard to occur even when the optical element unit may be manufactured in a separate step from a step for another mechanism, and to provide a manufacturing method for the optical unit.
In order to solve the problem, at least an embodiment of the present invention provides an optical unit with a shake correcting function including a fixed body, a movable module which holds an optical element, a spring member through which the movable module is supported by the fixed body so as to be capable of displacing, a shake detection sensor which detects a shake of the movable module, and a movable module drive mechanism for a shake correction which is provided between the movable module and the fixed body and which generates a magnetic drive force for relatively displacing the movable module with respect to the fixed body so as to cancel the shake on the basis of a detection result of the shake detection sensor. In a case that one side in an optical axis direction is a first direction and the other side is a second direction, the fixed body is provided with a fixed body side opening part which is larger than an optical element unit on a first direction side. In addition, the movable module includes the optical element unit which holds the optical element, a module cover which is supported by the fixed body so as to be capable of displacing through the spring member and is provided with a module cover side opening part larger than the optical element unit at a position superposed on the fixed body side opening part on the first direction side, a support part which supports an end part on a second direction side of the optical element unit, and a pressing member which supports an end part on the first direction side of the optical element unit.
Further, at least an embodiment of the present invention provides a manufacturing method for an optical unit with a shake correcting function, the optical unit including a fixed body, a movable module which holds an optical element, a spring member through which the movable module is supported by the fixed body so as to be capable of displacing, a shake detection sensor which detects a shake of the movable module, and a movable module drive mechanism for a shake correction which is provided between the movable module and the fixed body and which generates a magnetic drive force for relatively displacing the movable module with respect to the fixed body so as to cancel the shake on the basis of a detection result of the shake detection sensor. The manufacturing method includes, in a case that one side in an optical axis direction is a first direction and the other side is a second direction, previously providing the fixed body with a fixed body side opening part which is larger than an optical element unit on a first direction side, previously providing the movable module with the optical element unit which holds the optical element, a module cover which is supported by the fixed body so as to be capable of displacing through the spring member and is provided with a module cover side opening part larger than the optical element unit at a position superposed on the fixed body side opening part on the first direction side, a support part which supports an end part on a second direction side of the optical element unit, and a pressing member which supports an end part on the first direction side of the optical element unit. In addition, the manufacturing method includes a first step in which the module cover and the support part are mounted on the fixed body through the spring member and the movable module drive mechanism is provided between the module cover and the fixed body, a second step in which the optical element unit is inserted to an inner side of the module cover through the fixed body side opening part and the module cover side opening part, and a third step in which the pressing member is connected with the module cover.
In at least an embodiment of the present invention, the fixed body is provided with a fixed body side opening part which is opened in a first direction and the module cover is also provided with a module cover side opening part on the first direction side. Therefore, the module cover is mounted on the fixed body through the spring member and the movable module drive mechanism is provided between the module cover and the fixed body and, after that, the optical element unit can be inserted to an inner side of the module cover through the fixed body side opening part and the module cover side opening part. Accordingly, the optical element unit can be manufactured in a separate step from a step in which the module cover, the spring member, the movable module drive mechanism are attached to the fixed body. Therefore, different from a case that inspection is performed after all the members have been assembled, inspection can be performed during manufacturing. As a result, a loss caused by a defective product can be restrained. Further, the support part is provided on the second direction side with respect to the module cover and the pressing member is provided on the first direction side. Therefore, when the optical element unit is inserted in the inside of the module cover, the end part on the second side of the optical element unit is supported by the support part. Further, after the pressing member is attached, the end part on the first direction side of the optical element unit is supported by the pressing member. Therefore, different from a structure in which, after the optical element unit is accommodated in the inside of the module cover, the optical element unit is fixed to the inside of the module cover by adhesion, welding or the like, assembling is easily performed and displacement of the optical axis is hard to be occurred. Accordingly, the production efficiency and yield of the optical unit can be improved. In addition, after the optical element unit is mounted, only the optical element unit can be exchanged and, when the optical unit is to be manufactured, the optical element unit to be mounted can be easily changed to another optical element unit.
In at least an embodiment of the present invention, it is preferable that the module cover is provided with a tube-like shape body part which surrounds the optical element unit and a support plate part which is protruded toward the module cover side opening part from an end part on a second direction side of the tube-like shape body part as the support part. According to this structure, even when the support part is not structured of a separate member, the end part on the second direction side of the optical element unit is supported.
In at least an embodiment of the present invention, it may be adopted that the module cover is provided with a tube-like shape body part which surrounds the optical element unit, and the support part is a support member which is a separate member from the module cover and is provided on a second direction side with respect to the tube-like shape body part.
In at least an embodiment of the present invention, for example, the second direction is a direction to which an optical axis is extended in the optical element unit, and the first direction is an opposite direction to the side to which the optical axis is extended in the optical element unit.
In this case, it is preferable that the shake detection sensor is provided at a position which is not superposed on the optical element unit in the optical axis direction. According to this structure, in the optical element unit, even when the shake detection sensor is provided on the opposite side to the side where the optical axis is extended, the optical element unit can be inserted to the inner side of the module cover through the fixed body side opening part and the module cover side opening part. Therefore, the shake detection sensor is not required to be provided at a position superposed on the optical element unit on the second direction side after the optical element unit has been inserted to the inner side of the module cover and thus, the optical unit can be made relatively thin.
In at least an embodiment of the present invention, it may be structured that the first direction is a direction to which an optical axis is extended in the optical element unit, and the second direction is an opposite direction to the side to which the optical axis is extended in the optical element unit.
In this case, it is preferable that a connector member which is electrically connected with the optical element unit is disposed between the end part on the second direction side of the optical element unit and the support part. According to this structure, electric connection can be performed easily at the end part on the second direction side of the optical element unit.
In at least an embodiment of the present invention, it may be adopted that the optical element unit holds an imaging element as the optical element. Further, in at least an embodiment of the present invention, it may be adopted that the optical element unit holds an optical element drive mechanism for driving the optical element in the optical axis direction.
In at least an embodiment of the present invention, the module cover is mounted on the fixed body through the spring member and the movable module drive mechanism is provided between the module cover and the fixed body and, after that, the optical element unit can be inserted to an inner side of the module cover through the fixed body side opening part and the module cover side opening part. Therefore, the optical element unit can be manufactured in a separate step from a step in which the module cover, the spring member, the movable module drive mechanism are attached to the fixed body. Accordingly, different from a case that inspection is performed after all the members have been assembled, inspection can be performed during manufacturing. As a result, a loss caused by a defective product can be restrained. Further, when the optical element unit is inserted in the inside of the module cover, the end part on the second side of the optical element unit is supported by the support part and, after the pressing member has been attached, the end part on the first direction side of the optical element unit is supported by the pressing member. Therefore, different from a structure in which, after the optical element unit is accommodated in the inside of the module cover, the optical element unit is fixed to the inside of the module cover by adhesion, welding or the like, assembling is easily performed and displacement of the optical axis and the like are hard to be occurred. Accordingly, the production efficiency and yield of the optical unit can be improved. In addition, after the optical element unit is mounted, only the optical element unit can be exchanged and, when the optical unit is to be manufactured, the optical element unit to be mounted can be easily changed to another optical element unit.
BRIEF DESCRIPTION OF DRAWINGS
Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which:
FIGS. 1( a ) and 1 ( b ) are explanatory views showing an optical unit for photographing in accordance with a first embodiment of the present invention.
FIGS. 2( a ), 2 ( b ) and 2 ( c ) are explanatory views showing a fixed body and a movable module of the optical unit in accordance with the first embodiment of the present invention.
FIG. 3 is an explanatory view showing a photographing unit which is incorporated into the movable module of the optical unit in accordance with the first embodiment of the present invention.
FIG. 4 is an exploded perspective view showing the movable module of the optical unit in accordance with the first embodiment of the present invention.
FIGS. 5( a ) and 5 ( b ) are explanatory views showing a manufacturing method for the optical unit in accordance with the first embodiment of the present invention.
FIGS. 6( a ) and 6 ( b ) are explanatory views showing a manufacturing method for the optical unit in accordance with the first embodiment of the present invention.
FIGS. 7( a ) and 7 ( b ) are explanatory views showing an optical unit for photographing in accordance with a second embodiment of the present invention.
FIGS. 8( a ), 8 ( b ) and 8 ( c ) are explanatory views showing a fixed body and a movable module of the optical unit in accordance with the second embodiment of the present invention.
FIGS. 9( a ) and 9 ( b ) are explanatory views showing the movable module of the optical unit in accordance with the second embodiment of the present invention.
FIG. 10( a ) through 10 ( d ) are explanatory views showing a manufacturing method for the optical unit in accordance with the second embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following descriptions, a structure for preventing a hand shake in a photographing unit will be described below as an example for an optical element unit. Further, in the following descriptions, three directions perpendicular to each other are set to be an X-axis, a Y-axis and a Z-axis, and a direction along an optical axis “L” (lens optical axis) is set to be the Z-axis. Therefore, in the following descriptions, a swing around the X-axis of shakes in the respective directions corresponds to a so-called pitching (vertical swing), a swing around the Y-axis corresponds to a so-called yawing (lateral swing), and a swing around the Z-axis corresponds to a so-called rolling. Further, “+X” is attached on one side in the X-axis, “−X” is attached on the other side, and “+Y” is attached on one side in the Y-axis, “−Y” is attached on the other side, and “+Z” is attached on one side (opposite side to an object side) in the Z-axis, and “−Z” is attached on the other side (object side).
First Embodiment
In this embodiment, after a module cover and the like have been mounted on a fixed body, a photographing unit (optical element unit) is inserted into a module cover from an opposite side to an object to be photographed (side to which an optical axis is extended). Therefore, in this embodiment, “first direction” and “second direction” are as follow:
First direction=an opposite direction to a side to which the optical axis is extended (opposite side to an object to be photographed).
Second direction=a direction to which the optical axis is extended (object side to be photographed).
(Entire Structure of Optical Device for Photographing)
FIGS. 1( a ) and 1 ( b ) are explanatory views showing an optical unit for photographing in accordance with a first embodiment of the present invention. FIG. 1( a ) is a perspective view showing the optical unit which is viewed from an object side and FIG. 1( b ) is a perspective view showing the optical unit which is viewed from an opposite side to the object side. FIGS. 2( a ), 2 ( b ) and 2 ( c ) are explanatory views showing a fixed body and a movable module of the optical unit in accordance with the first embodiment of the present invention. FIG. 2( a ) is a perspective view showing a fixed body which is viewed from the opposite side to the object side, FIG. 2( b ) is a perspective view showing a movable module which is viewed from the opposite side to the object side, and FIG. 2( c ) is a perspective view showing the movable module which is viewed from the object side. In FIG. 2( a ), a fixed cover is not shown.
An optical unit 100 (optical unit with shake correcting function/photographic optical device) shown in FIGS. 1( a ) and 1 ( b ) and FIGS. 2( a ), 2 ( b ) and 2 ( c ) is a thin camera used in an optical device such as a cell phone with a camera. The optical unit 100 is formed in a roughly rectangular prism shape as a whole. The optical unit 100 is provided with a coil holding body 260 , a frame 270 which is fixed to the coil holding body 260 on an opposite side (“+Z”-axis direction) to an object side (“−Z”-axis direction), and a box-shaped fixed cover 230 which holds the coil holding body 260 and the frame 270 in its inner side. The fixed body 210 is structured of the coil holding body 260 , the frame 270 and the fixed cover 230 . A movable module 300 provided with a photographing unit 1 is disposed on an inner side of the fixed body 210 which is structured as described above. An upper plate part 231 located at an end part on the object side of the fixed cover 230 is formed with a rectangular window-shaped opening part 231 a . In this embodiment, a substantially all region superposed on the movable module 300 in an optical axis “L” direction is formed as the opening part 231 a . Further, an end part of the fixed cover 230 on the opposite side to the object side is formed to be an open end.
(Structure of Photographing Unit 1 )
FIG. 3 is an explanatory view showing the photographing unit 1 (optical element unit) which is incorporated into the movable module 300 of the optical unit 100 in accordance with the first embodiment of the present invention. A left half portion in FIG. 3 shows a view in which the movable body is located at an infinity position (normal photographing position) and a right half portion in FIG. 3 shows a view in which the movable body is located at a macro-position (close-up photographing position).
As shown in FIG. 3 , the photographing unit 1 is, for example, an optical element unit in which a plurality of lenses 10 as an optical element (see FIG. 1( a )) is moved in both directions, i.e., in an “A”-direction (front side) approaching an object to be photographed (object side) along the optical axis “L” direction and in a “B”-direction (rear side) approaching the opposite side (imaging element side/image side) to the object to be photographed. The photographing unit 1 is formed in a roughly rectangular prism shape. The photographing unit 1 is generally provided with the movable body 3 which holds optical elements such as a plurality of lenses 10 (see FIG. 1( a )) and a fixed diaphragm on its inner side, a lens drive mechanism 5 for moving the movable body 3 along the optical axis “L” direction, and a support body 2 on which the lens drive mechanism 5 , the movable body 3 and the like are mounted. The movable body 3 is provided with a lens holder 12 , which is formed in a cylindrical tube shape and holds the lenses and the fixed diaphragm, and a coil holder 13 which holds the lens holder 12 on its inner side. Lens drive coils 30 s and 30 t structuring the lens drive mechanism 5 are held on an outer peripheral side face of the coil holder 13 .
The support body 2 is provided with an imaging element holder 19 , which is formed in a rectangular plate shape and positions an imaging element 155 on the opposite side to the object side, a box-shaped case 18 which covers the imaging element holder 19 from the object side, and a spacer 11 which is formed in a rectangular plate shape and is disposed on an inner side of the case 18 . Circular incident windows 110 and 18 a are respectively formed at centers of the case 18 and the spacer 11 for taking light from the object to be photographed to the lenses. Further, a window 19 a for guiding the incident light to the imaging element 155 is formed at a center of the imaging element holder 19 . In the photographing unit 1 , the support body 2 is provided with a circuit board 151 on which the imaging element 155 is mounted and the circuit board 151 is fixed to an under face of the imaging element holder 19 .
The case 18 is made of a ferromagnetic plate such as a steel plate and also functions as a yoke. Therefore, the case 18 structures an interlinkage magnetic field generating body for generating interlinkage magnetic field in the lens drive coils 30 s and 30 t together with lens drive magnets 17 described below. The interlinkage magnetic field generating body structures the lens drive mechanism 5 together with the lens drive coils 30 s and 30 t which are wound around an outer peripheral face of the coil holder 13 .
The support body 2 and the movable body 3 are connected with each other through metal spring members 14 s and 14 t which are provided at positions separated in the optical axis “L” direction. Basic structures of the spring members 14 s and 14 t are similar to each other and they are provided with an outer peripheral side connecting part held by a support body 2 side, a ring-shaped inner peripheral side connecting part held by a movable body 3 side, and an arm-shaped plate spring part which connects the outer peripheral side connecting part with the inner peripheral side connecting part. The outer peripheral side connecting part of the spring member 14 s on the imaging element 155 side is held by the imaging element holder 19 and its inner peripheral side connecting part is connected with an end face on the imaging element side of the coil holder 13 of the movable body 3 . The outer peripheral side connecting part of the spring member 14 t on the object side is held by the spacer 11 and its inner peripheral side connecting part is connected with an end face on the object side of the coil holder 13 of the movable body 3 . In this manner, the movable body 3 is movably supported by the support body 2 in the optical axis “L” direction through the spring members 14 s and 14 t . Each of the spring members 14 s and 14 t is made of nonmagnetic metal such as beryllium copper or SUS steel material and is formed by means of that a thin plate having a certain thickness is performed by press working or etching processing using photo lithography technique. The spring member 14 s is divided into two pieces and respective coil ends of the lens drive coils 30 s and 30 t are respectively connected with the spring pieces. Further, the two spring pieces of the spring member 14 s are respectively formed with a terminal and thus the spring member 14 s functions as a power supply member to the lens drive coils 30 s and 30 t.
A ring-shaped magnetic piece 61 is held on an object side end face of the coil holder 13 and the magnetic piece 61 is located at a position on the object side with respect to the lens drive magnet 17 . Therefore, the magnetic piece 61 applies an urging force in the optical axis “L” direction to the movable body 3 by an attraction force acted between the lens drive magnet 17 and the magnetic piece 61 . Therefore, at a non-energized time (home position), the lens holder 12 is maintained on an imaging element 155 side in a stationary state by an attraction force acted between the lens drive magnet 17 and the magnetic piece 61 . Further, the magnetic piece 61 acts as a yoke and thus leakage flux from a magnetic path which is structured between the lens drive magnets 17 and the lens drive coils 30 s and 30 t is reduced. As the magnetic piece 61 , a bar-shaped magnetic body or a spherical magnetic body may be used. In a case that the magnetic piece 61 is formed in a ring shape, it is effective that, when the lens holder 12 is to be moved in the optical axis “L” direction, magnetic attraction forces acted between the lens drive magnets 17 and the magnetic piece 61 become isotropic. In addition, when the lens drive coils 30 s and 30 t are energized, the magnetic piece 61 is moved in a direction separated from the lens drive magnets 17 and thus an unnecessary force that the lens holder 12 is pressed against the imaging element 155 side is not acted. Therefore, the lens holder 12 is moved in the optical axis “L” direction with a small electric power.
In the photographing unit 1 in this embodiment, when viewed in the direction of the optical axis “L”, the lens 10 (see FIG. 1( a )) is circular but the case 18 used in the support body 2 is in a rectangular box-like shape. Therefore, the case 18 is provided with a rectangular tube-shaped body part 18 c and an upper plate part 18 b formed with the incident window 18 a is provided on the upper face side of the rectangular tube-shaped body part 18 c . The lens drive magnet 17 is fixed to side face parts which correspond to sides of a quadrangle of the rectangular tube-shaped body part 18 c . Each of the lens drive magnets 17 is formed of a rectangular flat plate-shaped permanent magnet. Each of four lens drive magnets 17 is divided into two pieces in the direction of the optical axis “L” and each magnet piece is magnetized so that a magnetic pole of its inner face and a magnetic pole of its outer face are different from each other.
In this embodiment, when the coil holder 13 is viewed in the direction of the optical axis “L”, its inner peripheral shape is circular but its outer peripheral side face which determines the outer peripheral shape of the coil holder 13 is quadrangular and the lens drive coils 30 s and 30 t are wound around the coil holder 13 . In this embodiment, four lens drive magnets 17 are respectively divided into two pieces in the optical axis “L” direction and each of the magnet pieces is magnetized so that a magnetic pole of its inner face and a magnetic pole of its outer face are different from each other and thus winding directions of the two lens drive coils 30 s and 30 t are opposite to each other. The movable body 3 structured as described above is disposed on an inner side of the case 18 . As a result, the lens drive coils 30 s and 30 t respectively face the lens drive magnets 17 which are fixed to the inner faces of the rectangular tube-shaped body parts 18 c of the case 18 .
In the photographing unit 1 structured as described above, the movable body 3 is normally located on the imaging element side (“+Z” side) and, in this state, when an electric current is supplied to the lens drive coils 30 s and 30 t in a predetermined direction, an electro-magnetic force toward the object side (“−Z” side) is applied to the respective lens drive coils 30 s and 30 t . Therefore, the movable body 3 to which the lens drive coils 30 s and 30 t are fixed begins to move to the object side (front side). In this case, elastic forces restricting movement of the movable body 3 are generated between the spring member 14 t and the front end of the movable body 3 and between the spring member 14 s and the rear end of the movable body 3 . Therefore, the movable body 3 is stopped when the electro-magnetic force for moving the movable body 3 to the front side and the elastic force for restricting the movement of the movable body 3 are balanced. In this case, when an amount of the electric current which is supplied to the lens drive coils 30 s and 30 t is adjusted depending on the elastic forces of the spring members 14 s and 14 t acting on the movable body 3 , the movable body 3 can be stopped at a desired position.
(Internal Structure of Optical Unit 100 )
In the optical unit 100 shown in FIGS. 1( a ) and 1 ( b ), a shake correction mechanism (hand shake correction mechanism) for displacing the photographing unit 1 to perform shake correction is structured on an inner side of the fixed cover 230 . In order to structure the shake correction mechanism, in this embodiment, as shown in FIGS. 1( a ) and 1 ( b ) and FIGS. 2( a ), 2 ( b ) and 2 ( c ), the optical unit 100 includes a fixed body 210 , a movable module 300 holding the photographing unit 1 on its inner side, and a plate-shaped spring member 600 which is connected with the fixed body 210 and the movable module 300 . A movable module drive mechanism is structured between the movable module 300 and the fixed body 210 for generating a magnetic drive force which relatively displaces the movable module 300 with respect to the fixed body 210 as described below. In the optical unit 100 , a sensor flexible circuit board 410 and a drive flexible circuit board 420 are disposed on an opposite side to the object side.
(Structure of Fixed Body 210 )
As shown in FIGS. 1( a ) and 1 ( b ) and FIG. 2( a ), in the fixed body 210 , the coil holding body 260 is provided with support pillar portions 261 at four corner portions and upper end parts of the support portions 261 are connected with each other through crosspiece parts 262 . The support pillar portion 261 is formed with a hole for passing a screw 279 (see FIG. 1( b )). Four side faces of the coil holding body 260 are fixed with two “X”-side coils 571 disposed on both sides of the movable module 300 in the “X”-axis direction and two “Y”-side coils 572 disposed on both sides of the movable module 300 in the “Y”-axis direction. The “X”-side coil 571 and the “Y”-side coil 572 are an air-core coil which is wound around in a rectangular frame shape and is provided with two effective side portions facing each other in the “Z”-axis direction.
In the fixed body 210 , a frame 270 formed in a rectangular frame shape is disposed on an opposite side to the object side so as to superpose on the coil holding body 260 . The frame 270 is provided with a rectangular frame-shaped part 271 and cylindrical tube parts 272 which are protruded toward the coil holding body 260 at four corner portions of the frame-shaped part 271 . The cylindrical tube part 272 is formed with a hole for passing a screw 279 (see FIG. 1( b )). The corner portions of the coil holding body 260 are superposed on the cylindrical tube parts 272 of the frame 270 . Therefore, the coil holding body 260 and the frame 270 are fixed to each other at four corner portions by the screws 279 and, in this fixed state, a fixed body side opening part 210 b whose size is larger than an area of the photographing unit 1 when projected in the optical axis “L” direction is opened in the optical axis “L” direction on the opposite side to the object side in the fixed body 210 .
An auxiliary circuit board 450 is used for power supply to the “X”-side coils 571 and the “Y”-side coils 572 . An end part of the auxiliary circuit board 450 is fixed to an under face of the frame 270 (face on the opposite side to the object side) when the frame 270 and the coil holding body 260 are connected with each other by the screws 279 .
(Structure of Movable Module 300 )
FIG. 4 is an exploded perspective view showing the movable module 300 of the optical unit 100 in accordance with the first embodiment of the present invention. As shown in FIGS. 1( a ) and 1 ( b ), FIGS. 2( b ) and 2 ( c ) and FIG. 4 , the movable module 300 in the optical unit 100 in this embodiment is provided with the photographing unit 1 described with reference to FIG. 3 , a rectangular tube-shaped module cover 390 which accommodates the photographing unit 1 on its inner side, a sensor holding plate 370 which is formed in a rectangular frame shape and is disposed so as to superpose on one side of the module cover 390 in the “Z”-axis direction, and a pressing member 380 which is disposed so as to superpose on one side of the sensor holding plate 370 in the “Z”-axis direction.
The module cover 390 is provided with a rectangular tube-shaped body part 398 . An outer face of the rectangular tube-shaped body part 398 is fixed with “X”-side magnets 581 which are disposed on both sides of the movable module 300 in the “X”-axis direction and “Y”-side magnets 582 which are disposed on both sides of the movable module 300 in the “Y”-axis direction. Each of the “X”-side magnet 581 and the “Y”-side magnet 582 is structured of two flat plate-shaped magnet pieces arranged in the “Z”-axis direction. The two magnet pieces are magnetized so that an inner face and an outer face are magnetized in different poles from each other and are magnetized so that magnetic poles in the optical axis “L” direction are different from each other. The module cover 390 is made of a magnetic plate and functions as a back yoke.
An inner side of the rectangular tube-shaped body part 398 is formed as a sensor accommodation part 396 where a gyroscope 180 (shake detection sensor/angular velocity sensor) is accommodated and as a photographing unit accommodation part 397 where the photographing unit 1 is accommodated. The sensor accommodation part 396 is provided with an upper plate part 394 . In the sensor accommodation part 396 , a block 305 is located on a lower side of the upper plate part 394 and the gyroscope 180 is disposed at a lower position of the block 305 .
In the module cover 390 , an object side end part of a portion of the rectangular tube-shaped body part 398 corresponding to the photographing unit accommodation part 397 is located on a further object side with respect to the upper plate part 35 of the sensor accommodation part 396 . Four corner portions of the photographing unit accommodation part 397 are formed with a triangular support plate part 395 (support part).
Further, end parts on the opposite side to the object side at four corner portions of the rectangular tube-shaped body part 398 of the module cover 390 are formed with a connecting part 393 protruded toward an outer peripheral side. Each of the four connecting parts 393 is formed with a hole for passing a screw 108 .
In this embodiment, an object side end part of the rectangular tube-shaped body part 398 of the module cover 390 is formed as an open end and, in the module cover 390 , a module cover side opening part 390 b is opened in the optical axis “L” direction. An area of the module cover side opening part 390 b is larger than a projected area of the photographing unit 1 in the optical axis “L” direction and the module cover side opening part 390 b is superposed on the fixed body side opening part 210 b.
An end part 10 e on the object side of the photographing unit 1 is formed with four triangular recessed parts 102 which are recessed in the optical axis “L” direction at a portion superposed on the support plate part 395 of the module cover 390 . When the photographing unit 1 is accommodated on the inner side of the module cover 390 , the support plate parts 395 of the module cover 390 are fitted to the recessed parts 102 of the photographing unit 1 .
Further, in four outer side faces of the photographing unit 1 , an end face located on the “−Y”-axis side is formed with two projections 103 and both side end parts of an end face located on the “+Y”-axis side are formed with a projection 104 . In this embodiment, the outer side of the photographing unit 1 is the case 18 shown in FIG. 3 and thus all of the end part 10 e , the recessed parts 102 , the projections 103 and the projections 104 are formed by using the case 18 . An end face of the photographing unit 1 on the opposite side to the object side is connected with a circuit board main body part of a sub circuit board 440 of the drive flexible circuit board 420 .
The sensor holding plate 370 is provided with a rectangular frame part 371 and cylindrical tube parts 372 which are protruded toward the module cover 390 at diagonal positions of the rectangular frame part 371 . The cylindrical tube part 372 is formed with a through hole for fitting a screw 108 , and a hole 371 a for fitting a screw 109 is formed in a pair of side parts facing each other and another side part of the rectangular frame part 371 . Further, an inner edge of the side part of the rectangular frame part 371 where only one hole 371 a is formed is formed with two cut-out parts 371 c for holding an elastic spacer 106 on an inner side.
The pressing member 380 includes a rectangular flat plate part 381 , two seat parts 386 which are protruded toward the sensor holding plate 370 from a pair of side parts facing each other of the flat plate part 381 , and a seat part 385 which is protruded toward the sensor holding plate 370 from another side part of the flat plate part 381 . The seat parts 385 and 386 are formed with a hole for passing the screw 109 . In this embodiment, a dimension in the “X” direction of the seat part 385 is longer than that of the seat part 386 .
(Structure of Drive Flexible Circuit Board 420 )
As shown in FIGS. 1( a ) and 1 ( b ), FIGS. 2( a ) through 2 ( c ) and FIG. 4 , in the optical unit 100 , the drive flexible circuit board 420 is disposed on the opposite side to the object side with respect to the fixed body 210 . The drive flexible circuit board 420 is comprised of a main circuit board 430 and a sub circuit board 440 connected with the main circuit board 430 . The main circuit board 430 is provided with a circuit board main body part 431 which is formed in a connected shape of two rectangular portions and two belt-shaped elongated connecting parts 432 and 433 which are extended toward the “+Y”-axis direction from both end portions in a widthwise direction (“X”-axis direction) of the circuit board main body part 431 . The sub circuit board 440 is provided with a rectangular circuit board main body part (not shown) and strip-shaped connection parts 442 and 443 which are extended toward the “+Y”-axis direction from portions located on a little inner side with respect to both end portions in the widthwise direction (“X”-axis direction) of the circuit board main body part and then are bent toward both sides in the “X”-axis direction. In this embodiment, tip end parts of the elongated connecting parts 432 and 433 of the main circuit board 430 and tip end parts of the strip-shaped connection parts 442 and 443 of the sub circuit board 440 are joined to each other. In this manner, the main circuit board 430 and the sub circuit board 440 are integrated with each other to structure the drive flexible circuit board 420 and the main circuit board 430 and the sub circuit board 440 are electrically connected with each other.
(Structure of Sensor Flexible Circuit Board 410 )
In the optical unit 100 , a sensor flexible circuit board 410 is disposed on the opposite side to the object side with respect to the photographing unit 1 . The sensor flexible circuit board 410 is provided with a rectangular circuit board main body part 411 , belt-shaped elongated connecting parts 412 and 413 which are extended toward the “+Y”-axis direction from both end portions in a widthwise direction (“X” direction) of the circuit board main body part 411 , and a sensor mounting part 414 having a wider width which connects tip end parts of the elongated connecting parts 412 and 413 . Further, the sensor flexible circuit board 410 is provided with a bent portion 416 which is extended from a portion of the sensor mounting part 414 so as to be interposed between the elongated connecting parts 412 and 413 . The bent portion 416 is perpendicularly bent toward the object side in the vicinity of a connecting part with the sensor mounting part 414 and then is bent toward one side in the “Y”-axis direction.
In the sensor flexible circuit board 410 , a gyroscope 180 as a hand shake sensor (angular velocity sensor) is mounted on the sensor mounting part 414 and a block 305 is mounted on an inner side of the bent portion 416 . The block 305 functions as a pressing and fixing member for the gyroscope 180 .
(Structure of Spring Member 600 )
The movable module 300 which is structured as described above is supported by the plate-shaped spring member 600 in a state so as to be capable of displacing with respect to the fixed body 210 described with reference to FIGS. 2( a ) through 2 ( c ). As shown in FIG. 2( c ), the spring member 600 is provided with movable module side connecting parts 610 which are disposed on an inner side and are connected with the movable module 300 , fixed body side connecting parts 620 which are disposed on an outer side and are connected with the fixed body 210 , and arm parts 630 which are extended between the movable module side connecting part 610 and the fixed body side connecting part 620 . The movable module side connecting part 610 and the fixed body side connecting part 620 are respectively formed with a hole for passing the screw 108 and the screw 279 . The spring member 600 is made of nonmagnetic metal such as beryllium copper or nonmagnetic SUS steel material and is formed by means of that a thin plate having a certain thickness is performed by press working or etching processing using photo lithography technique.
In this embodiment, the spring member 600 is formed in a rectangular frame shape as a whole and each of the movable module side connecting part 610 and the fixed body side connecting part 620 is disposed at four corner portions of the spring member 600 . Each of the four arm parts 630 is extended in the same direction in the circumferential direction from the movable module side connecting part 610 and is perpendicularly bent and extended to the fixed body side connecting part 620 . In accordance with an embodiment of the present invention, the spring member 600 may be structured so that the movable module side connecting parts 610 and the fixed body side connecting parts 620 are connected with each other in the circumferential direction.
(Manufacturing Method for Optical Unit 10 )
FIGS. 5( a ) and 5 ( b ) and FIGS. 6( a ) and 6 ( b ) are explanatory views showing a manufacturing method for the optical unit 100 in accordance with the first embodiment of the present invention. In the following descriptions, a state where the fixed cover 230 is detached from the fixed body 210 is referred to as the fixed body 210 . However, the following steps may be performed in a state that the fixed cover 230 is attached.
In order to manufacture the optical unit 100 in this embodiment, the sensor holding plate 370 and the module cover 390 are connected with each other with the screws 108 . In this case, the movable module side connecting parts 610 of the spring member 600 have been previously disposed between the cylindrical tube parts 372 of the sensor holding plate 370 and the connecting parts 393 of the module cover 390 . Therefore, when the sensor holding plate 370 and the module cover 390 are connected with each other with the screws 108 , the movable module side connecting parts 610 of the spring member 600 are sandwiched between the sensor holding plate 370 and the module cover 390 . Further, in this case, the sensor mounting part 414 of the sensor flexible circuit board 410 on which the gyroscope 180 is mounted and the bent portion 416 on which the block 305 is mounted have been previously disposed between sensor holding plate 370 and module cover 390 . As a result, the gyroscope 180 is set in a state that the gyroscope 180 is sandwiched together with the block 305 between the module cover 390 and the sensor holding plate 370 . In this state, the center of the gyroscope 180 is located in a region surrounded by the connecting positions (positions of the screws 108 ) of the module cover 390 with the pressing member 380 . In this embodiment, the gyroscope 180 is formed in a rectangular flat shape and thus the center of the gyroscope 180 is determined as an intersecting point of straight lines obtained by connecting diagonal corners of the gyroscope 180 .
Next, in the fixed body 210 shown in FIG. 2( a ), when the frame 270 and the coil holding body 260 are to be connected with each other with the screws 279 , the fixed body side connecting parts 620 of the spring member 600 are disposed between the cylindrical tube parts 272 of the frame 270 and the support pillar portions 261 of the coil holding body 260 . Therefore, the fixed body side connecting parts 620 of the spring member 600 are sandwiched between the frame 270 and the coil holding body 260 . In this state, the module cover 390 and the sensor holding plate 370 are set in a supported state so as to be capable of displacing with respect to the fixed body 210 through the spring member 600 (first step).
In this case, the circuit board main body part 411 of the sensor flexible circuit board 410 and the end part of the auxiliary circuit board 450 are superposed on the frame 270 and, in this state, the screws 279 are fixed. As a result, the circuit board main body part 411 of the sensor flexible circuit board 410 and the end part of the auxiliary circuit board 450 are fixed to the frame 270 with the screws 279 . Further, in the state where the module cover 390 and the sensor holding plate 370 are disposed on the inner side of the fixed body 210 , the “X”-side magnets 581 of the movable module 300 and the “X”-side coils 571 of the coil holding body 260 are faced each other to structure an “X”-side magnetic drive mechanism of the movable module drive mechanism. Further, the “Y”-side magnets 582 of the movable module 300 and the “Y”-side coils 572 of the coil holding body 260 are faced each other to structure a “Y”-side magnetic drive mechanism of the movable module drive mechanism.
Further, as shown in FIG. 5( a ), the elongated connecting parts 412 and 413 of the sensor flexible circuit board 410 are located on side positions with respect to a space where the photographing unit 1 is inserted. The module cover side opening part 390 b of the module cover 390 is not closed by the elongated connecting parts 412 and 413 of the sensor flexible circuit board 410 . Further, the fixed body side opening part 210 b of the fixed body 210 is larger than the module cover side opening part 390 b and thus, even when the module cover 390 is disposed on the inner side of the fixed body 210 , the module cover side opening part 390 b is not closed by the fixed body 210 .
Next, as shown in FIG. 5( b ), the photographing unit 1 is inserted into an inner side of the module cover 390 from the end part of the module cover 390 on the opposite side to the object side through the fixed body side opening part 210 b and the module cover side opening part 390 b to dispose the photographing unit 1 on the inner side of the module cover 390 (second step).
Next, as shown in FIG. 6( a ), an elastic spacer 106 made of rubber or the like is fitted to the cut-out parts 371 c of the sensor holding plate 370 and the recessed corner portions of the rectangular frame part 371 . As a result, the elastic spacer 106 is disposed at positions superposed on the projections 103 and 104 of the photographing unit 1 in the optical axis “L” direction. In this case, the circuit board main body part 441 of the sub circuit board 440 has been joined to the end face on the opposite side to the object side of the photographing unit 1 .
After that, as shown in FIG. 6( b ), the pressing member 380 is superposed on the photographing unit 1 on the opposite side to the object side and screws 109 are fitted to the holes 371 a of the sensor holding plate 370 through the holes of the seat parts 385 and 386 of the pressing member 380 and thus the pressing member 380 is connected with the module cover 390 through the sensor holding plate 370 . As a result, the photographing unit 1 is sandwiched between the support plate part 395 of the module cover 390 and the pressing member 380 .
After that, as shown in FIG. 1( b ), the main circuit board 430 is superposed and the circuit board main body part 431 is fixed to the frame-shaped part 271 of the frame 270 by the fixing plate 480 with screws 491 . As a result, the tip end parts of the elongated connecting parts 432 and 433 of the main circuit board 430 and the tip end parts of the strip-shaped connection parts 442 and 443 of the sub circuit board 440 are superposed on each other and thus the tip end parts of the elongated connecting parts 432 and 433 of the main circuit board 430 and the tip end parts of the strip-shaped connection parts 442 and 443 of the sub circuit board 440 are joined with each other.
When the optical unit 100 is assembled as described above, the movable module 300 is supported so as to be capable of being displaced with respect to the fixed body 210 through the spring member 600 . Further, on the object side, the recessed part 102 is fitted to the support plate part 395 of the module cover 390 and the photographing unit 1 is directly abutted with the module cover 390 and, on the opposite side to the object side, the projections 103 and 104 of the photographing unit 1 and the seat parts 385 and 386 of the pressing member 380 are abutted with each other through the elastic spacer 106 . Therefore, even when dimensional errors are occurred in the respective members, the dimensional errors are absorbed by compression of the elastic spacer 106 .
In accordance with an embodiment of the present invention, it may be manufactured that, in a step before the movable module 300 has been assembled, the tip end parts of the elongated connecting parts 432 and 433 of the main circuit board 430 and the tip end parts of the strip-shaped connection parts 442 and 443 of the sub circuit board 440 are joined to each other to structure the drive flexible circuit board 420 and, in this state, the circuit board main body part 441 of the sub circuit board 440 is joined to the end face on the opposite side to the object side of the photographing unit 1 .
(Hand Shake Correcting Operation)
In a monitoring result of the gyroscope 180 in the optical unit 100 in this embodiment, when the movable module 300 is detected to be swung around the “Y”-axis by a hand shake, energization to the “X”-side coils 571 is controlled so as to cancel the shake and the movable module 300 is swung around the “Y”-axis. Further, in a monitoring result of the gyroscope 180 , when the movable module 300 is detected to be swung around the “X”-axis by a hand shake, energization to the “Y”-side coils 572 is controlled so as to cancel the shake and the movable module 300 is swung around the “X”-axis. Therefore, the swing of the movable module 300 can be corrected. Further, when the swing around the “X”-axis of the movable module 300 and the swing around the “Y”-axis are combined with each other, the movable module 300 can be displaced for the entire “X-Y” plane. Therefore, all shakes occurred in the optical unit 100 can be corrected surely.
(Principal Effects in this Embodiment)
As described above, in the optical unit 100 and its manufacturing method in this embodiment, the fixed body 210 is provided with the fixed body side opening part 210 b which is opened on an opposite side (first direction side) to an object to be photographed side and the module cover 390 is provided with the module cover side opening part 390 b on an opposite side (first direction) to the object side at a position superposed on the fixed body side opening part 210 b . Therefore, in the first step, the module cover 390 is mounted on the fixed body 210 through the spring member 600 and the movable module drive mechanism 500 is provided between the module cover 390 and the fixed body 210 and, after that, in the second step, the photographing unit 1 is inserted on the inner side of the module cover 390 through the fixed body side opening part 210 b and the module cover side opening part 390 b . Therefore, the photographing unit 1 can be manufactured in a separate step from a step in which the module cover 390 , the spring member 600 , the movable module drive mechanism 500 are attached to the fixed body 210 . Accordingly, different from a case that inspection is performed after all the members have been assembled, inspection can be performed during manufacturing. Therefore, a loss caused by a defective product can be restrained.
Further, the support plate part 395 as a support part is provided on the object side (second direction side) of the module cover 390 and the pressing member 380 is provided on the opposite side (first direction side) to the object side. Therefore, when the photographing unit 1 is inserted in the inside of the module cover 390 , the end part on the object side of the photographing unit 1 (second direction side) is supported by the support plate part 395 . Further, after the pressing member 380 is attached, the end part on the opposite side (first direction side) to the object side of the photographing unit 1 is supported by the pressing member 380 . Therefore, different from a structure in which, after the photographing unit 1 is accommodated in the inside of the module cover 390 , the photographing unit 1 is fixed to the inside of the module cover 390 by adhesion, welding or the like, assembling is easily performed and displacement of the optical axis “L” or the like is hard to be occurred. Accordingly, the production efficiency and yield of the optical unit 100 can be improved.
In addition, after the photographing unit 1 is mounted, only the photographing unit 1 can be exchanged and, when the optical unit 100 is to be manufactured, the photographing unit 1 can be easily changed to another photographing unit 1 .
Further, in this embodiment, the support part which supports the end part on the object side of the photographing unit 1 (second direction side) is the support plate part 395 of the module cover 390 and thus, even when the support part is not structured by using a separate member, the end part on the object side of the photographing unit 1 (second direction side) is supported. Moreover, the portion of the photographing unit 1 which is superposed on the support plate part 395 is formed with the recessed part 102 which is recessed in the optical axis “L” direction and thus, even when the module cover 390 is provided with the support plate part 395 , the movable module 300 can be made thinner by a depth of the recessed part 102 and the optical unit 100 can be effectively made thinner.
Further, the module cover 390 and the photographing unit 1 are directly abutted with each other and the pressing member 380 is abutted with the photographing unit 1 through the elastic spacer 106 . Therefore, even when dimensional errors are occurred in the respective members, the dimensional errors are absorbed by compression of the elastic spacer 106 and thus the photographing unit 1 is surely sandwiched between the module cover 390 and the pressing member 380 . In this case, since the sensor holding plate 370 is surely connected, the gyroscope 180 detects a shake of the movable module 300 surely.
Further, in this embodiment, the sensor holding plate 370 is disposed so as to surround the periphery of the photographing unit 1 and the gyroscope 180 is held by the sensor holding plate 370 at a position where the gyroscope 180 is not superposed on the photographing unit 1 in the optical axis “L” direction. Therefore, since the gyroscope 180 and the photographing unit 1 are not superposed on each other in the optical axis “L” direction, the dimension in the optical axis “L” direction (thickness dimension) of the movable module 300 is reduced. Further, when the photographing unit 1 is to be inserted into the inner side of the module cover 390 , the photographing unit 1 is not obstructed by the gyroscope 180 .
Further, the sensor holding plate 370 is connected with both of the module cover 390 and the pressing member 380 and thus rigidity of the sensor holding plate 370 is large. In addition, the center position of the gyroscope 180 is disposed in a region surrounded by the connected portions of the sensor holding plate 370 with the module cover 390 and thus rigidity of the portion of the sensor holding plate 370 where the center of the gyroscope 180 is located is large. Therefore, the portion of the sensor holding plate 370 where the center of the gyroscope 180 is located is hard to vibrate and thus, even when the movable module 300 and the optical unit 100 are made thinner, unnecessary vibration is hard to occur in the gyroscope 180 and a shake of the movable module 300 can be surely corrected.
Second Embodiment
In the second embodiment, after a module cover and the like are mounted on a fixed body, a photographing unit (optical element unit) is inserted in the inside of the module cover from an object side (side to which an optical axis “L” is extended). Therefore, in the second embodiment, “first direction” and “second direction” are as follows:
First direction=direction where an optical axis “L” is extended (object side to be photographed)
Second direction=direction opposite to a side where the optical axis “L” is extended (opposite side to an object to be photographed)
(Structure of Optical Unit)
FIGS. 7( a ) and 7 ( b ) are explanatory views showing an optical unit for photographing in accordance with a second embodiment of the present invention. FIG. 7( a ) is a perspective view showing the optical unit which is viewed from an object to be photographed side and FIG. 7( b ) is a perspective view showing the optical unit which is viewed from an opposite side to the object side. FIGS. 8( a ), 8 ( b ) and 8 ( c ) are explanatory views showing a fixed body and a movable module of the optical unit in accordance with the second embodiment of the present invention. FIG. 8( a ) is a perspective view showing a fixed body which is viewed from an object side, FIG. 8( b ) is a perspective view showing a movable module which is viewed from the object side, and FIG. 8( c ) is a perspective view showing the movable module which is viewed from an opposite side to the object side. In FIG. 8( a ), a fixed cover is not shown. Further, a basic structure in the second embodiment is similar to the first embodiment and thus the same reference signs are used in portions having the common functions.
An optical unit 100 shown in FIGS. 7( a ) and 7 ( b ) and FIGS. 8( a ), 8 ( b ) and 8 ( c ) is, similarly to the first embodiment, a thin camera used in a cell phone with a camera and is formed in a roughly rectangular prism shape as a whole. Also in this embodiment, in order to structure a shake correction mechanism, the optical unit 100 includes a fixed body 210 comprised of a fixed cover 230 and a coil holding body 260 , a movable module 300 holding the photographing unit 1 on its inner side, and a plate-shaped spring member 600 which is connected with the fixed body 210 and the movable module 300 , and a movable module drive mechanism 500 for generating a magnetic drive force which relatively displaces the movable module 300 with respect to the fixed body 210 between the movable module 300 and the fixed body 210 . The spring member 600 is provided with a movable module side connecting part 610 which is disposed on an inner side and is connected with the movable module 300 , a fixed body side connecting part 620 which is disposed on an outer side and is connected with the fixed body 210 , and an arm part 630 which is extended between the movable module side connecting part 610 and the fixed body side connecting part 620 .
(Structure of Fixed Body 210 )
An upper plate part 211 of the fixed cover 210 which is located at an end part on the object side is formed with a rectangular window-shaped opening part 211 a . In this embodiment, an opening part 211 a is formed in a wide region including a region superposed on the photographing unit 1 in the optical axis “L” direction.
A coil holding body 260 which is used in the fixed body 210 is comprised of a first coil holding member 270 which is formed in a rectangular frame shape and is located on an opposite side to the object side and a second coil holding member 280 which is disposed on the object side so as to be superposed on the first coil holding member 270 . First coils 541 , 542 , 543 and 544 are held on a side face of the first coil holding member 270 . Further, second coils 551 , 552 , 553 and 554 are held on a side face of the second coil holding member 280 . The first coils 541 , 542 , 543 and 544 and the second coils 551 , 552 , 553 and 554 are an air-core coil which is wound around in a rectangular frame shape and is provided with two effective side portions facing each other in the “Z”-axis direction.
In this embodiment, in order to structure the coil holding body 260 by using the first coil holding member 270 and the second coil holding member 280 , the first coil holding member 270 and the second coil holding member 280 are disposed so as to be superposed on each other in the “Z”-axis direction and then, four pin-shaped terminals 591 formed in a square bar shape are press-fitted to holes formed at four corner portions to connect the first coil holding member 270 and the second coil holding member 280 with each other. In this case, when the fixed body side connecting part 620 of the spring member 600 is disposed between the first coil holding member 270 and the second coil holding member 280 , the fixed body side connecting part 620 is sandwiched and held by the first coil holding member 270 and the second coil holding member 280 .
In this embodiment, the pin-shaped terminal 591 is penetrated through the first coil holding member 270 and the second coil holding member 280 in the “Z”-axis direction and both end parts of the pin-shaped terminal 591 are protruded from the coil holding body 260 . Therefore, the first coils 541 through 544 and the second coils 551 through 554 can be electrically connected through four metal pin-shaped terminals 591 . Accordingly, when two pin-shaped terminals 591 and two power supply terminals 594 held by the first coil holding member 270 are soldered to a sensor flexible circuit board 410 , power supply to the first coils 541 through 544 and the second coils 551 through 554 can be performed.
An end part on the object side of the coil holding body 260 structured as described above is formed with an opening part 260 a which is opened in the optical axis “L” direction. The opening part 260 a has the same size as the opening part 211 a of the fixed cover 210 and the size is larger than an area that the photographing unit 1 is projected in the optical axis “L” direction. In this embodiment, both of the opening parts 211 a and 260 a are included in the fixed body side opening part 210 a.
(Structure of Movable Module 300 )
FIGS. 9( a ) and 9 ( b ) are explanatory views showing the movable module 300 of the optical unit 100 in accordance with the second embodiment of the present invention. FIG. 9( a ) is an exploded perspective view showing the movable module 300 when viewed from an object to be photographed side and FIG. 9( b ) is an exploded perspective view showing the movable module 300 when viewed from an opposite side to the object side.
As shown in FIGS. 8( b ) and 8 ( c ) and FIGS. 9( a ) and 9 ( b ), in the optical unit 100 in this embodiment, the movable module 300 is provided with the photographing unit 1 which is described with reference to FIG. 3 , a rectangular tube-shaped module cover 310 which accommodates the photographing unit 1 on its inner side, a support member 330 which is connected with the module cover 310 on the opposite side to the object side with respect to the photographing unit 1 , and a rectangular pressing member 350 which is connected with the module cover 310 on the object side with respect to the photographing unit 1 .
In this embodiment, the module cover 310 is formed in a rectangular tube shape and is provided with a module cover side opening part 310 a on the object side which is opened in the optical axis “L” direction and whose size is larger than an area formed by projecting the photographing unit 1 in the optical axis “L” direction. Further, the module cover 310 is provided with an opening part 310 c on the opposite side to the object side and a connector member 910 mounted on a drive flexible circuit board 420 described below is located on an inner side of the opening part 310 c.
The pressing member 350 is formed with a circular hole 350 a for guiding light from an object to be photographed to the photographing unit 1 . Further, the pressing member 350 is provided with hooks 353 which are protruded from the vicinities of four corners toward the module cover 310 . The hooks 353 are engaged with engaging projections 318 of the module cover 310 and thus the pressing member 350 and the module cover 310 are connected with each other.
The support member 330 is provided with a hook 338 in two side portions facing each other in the “X”-axis direction and is also provided with a hook 338 in one side portion in the “Y”-axis direction. In this embodiment, bent portions of a plurality of the hooks 338 are located at different height positions and a bent portion to an inner side of the module cover 310 is fitted to a portion between the bent portions of the hook parts and, in this manner, the support member 330 and the module cover 310 are connected with each other. Further, an upper face of the support member 330 is provided with a gyro stopper (not shown). The gyro stopper secures a space for disposing the gyroscope 180 between the support member 330 and the photographing unit 1 .
Further, the movable module 300 is provided with a first spacer member 321 and a second spacer member 322 which are fixed to an outer peripheral face of the module cover 310 . The first spacer member 321 and the second spacer member 322 are fixed to the outer peripheral face of the module cover 310 in the vicinity of a substantially center in the optical axis “L” direction and the first spacer member 321 and the second spacer member 322 are adjacent to each other in the optical axis “L” direction.
Two first magnets 561 formed in a rectangular flat plate shape are disposed on each of four outer faces of the module cover 310 on the opposite side to the object side with respect to the first spacer member 321 so as to be adjacent to each other in the “Z”-axis direction. Further, two second magnets 562 formed in a rectangular flat plate shape are disposed on each of the four outer faces of the module cover 310 on the object side with respect to the second spacer member 322 so as to be adjacent to each other in the “Z”-axis direction.
(Holding Structure of Spring Member 600 on Movable Module 300 Side)
In this embodiment, the first spacer member 321 and the second spacer member 322 are used as a pair of spring holding members and the movable module side connecting part 610 of the spring member 600 and the module cover 310 (movable module 300 ) are connected with each other. In other words, when the first spacer member 321 and the second spacer member 322 are to be fixed to the module cover 310 , the movable module side connecting part 610 of the spring member 600 is disposed between the first spacer member 321 and the second spacer member 322 . As a result, the movable module side connecting part 610 of the spring member 600 is sandwiched and held by the first spacer member 321 and the second spacer member 322 from both sides in the optical axis “L” direction. Adhesion, welding or the like is performed in a state that the movable module side connecting part 610 of the spring member 600 is sandwiched and held by the first spacer member 321 and the second spacer member 322 .
(Structure of Movable Module Drive Mechanism 500 )
When the movable module 300 structured as described above is disposed on an inner side of the coil holding body 260 which is described with reference to FIG. 8( a ) and the like, the first magnets 561 of the movable module 300 face the first coils 541 , 542 , 543 and 544 of the coil holding body 260 to structure the movable module drive mechanism 500 . Further, the second magnets 562 of the movable module 300 face the second coils 551 , 552 , 553 and 554 of the coil holding body 260 to structure the movable module drive mechanism 500 . The movable module drive mechanism 500 is structured so as to sandwich the movable module 300 on both sides in the “X”-axis direction and is structured so as to sandwich the movable module 300 on both sides in the “Y”-axis direction. Therefore, when energization control to the first coils 541 through 544 and the second coils 551 through 554 is performed on the basis of a detection result of the gyroscope 180 , swing of the movable module 300 can be corrected.
A sensor flexible circuit board 410 and a drive flexible circuit board 420 are disposed on the opposite side to the object side in the optical unit 100 and the gyroscope 180 is mounted on the sensor flexible circuit board 410 .
An external connection part 425 of the drive flexible circuit board 420 is electrically connected with the sensor flexible circuit board 410 and the drive flexible circuit board 420 is extended to an outer side of the optical unit 100 . The drive flexible circuit board 420 is used for energization control to the first coils 541 , 542 , 543 and 544 and the second coils 551 , 552 , 553 and 554 from the outside.
Further, the drive flexible circuit board 420 is used for inputting and outputting a signal to and from the photographing unit 1 and a “Board-to-Board” type connector 900 is used for electrically connecting the drive flexible circuit board 420 with the photographing unit 1 . Therefore, a connector member 910 is mounted on the drive flexible circuit board 420 and a connector member 920 is mounted on an end part on the opposite side to the object side of the photographing unit 1 . The connector member 920 is connected with the connector member 910 to structure the connector 900 .
(Manufacturing Method for Optical Unit 10 )
FIG. 10( a ) through 10 ( d ) are explanatory views showing a manufacturing method for the optical unit 100 in accordance with the second embodiment of the present invention. In order to manufacture the optical unit 100 in this embodiment, first, as shown in FIGS. 10( a ) and 10 ( b ), in the first step, the module cover 310 is mounted on the fixed body 210 through the spring member 600 . In this case, the support member 330 has been attached to an end part on the opposite side to the object side of the module cover 310 . Further, the sensor flexible circuit board 410 and the drive flexible circuit board 420 are disposed on the opposite side to the object side of the module cover 310 . In this state, the connector member 910 is located on an inner side of the opening part 310 c on the opposite side to the object side of the module cover 310 .
Next, in the second step, as shown in FIGS. 10( c ) and 10 ( d ), the photographing unit 1 is inserted on an inner side of the module cover 310 through the fixed body side opening part 210 a and the module cover side opening part 310 a . As a result, the connector member 920 provided in the photographing unit 1 is connected with the connector member 910 which is mounted on the drive flexible circuit board 420 .
Next, in the third step, as shown in FIG. 7( a ), the pressing member 350 is attached to an end part on the object side of the module cover 310 and the end part on the object side of the photographing unit 1 is pressed and supported by the pressing member 350 .
(Principal Effects in this Embodiment)
As described above, in the optical unit 100 and its manufacturing method in this embodiment, the fixed body 210 is provided with the fixed body side opening part 210 a which is opened on the object side (first direction side) and the module cover 390 is provided with the module cover side opening part 390 a on the object side (first direction) at a position superposed on the fixed body side opening part 210 a . Therefore, in the first step, the module cover 310 is mounted on the fixed body 210 through the spring member 600 and the movable module drive mechanism 500 is provided between the module cover 310 and the fixed body 210 and, after that, in the second step, the photographing unit 1 is inserted on the inner side of the module cover 310 through the fixed body side opening part 210 a and the module cover side opening part 390 a . Therefore, the photographing unit 1 can be manufactured in a separate step from a step in which the module cover 310 , the spring member 600 , the movable module drive mechanism 500 are attached to the fixed body 210 . Accordingly, different from a case that inspection is performed after all the members have been assembled, inspection can be performed during manufacturing. Therefore, a loss caused by a defective product can be restrained.
Further, the support member 330 as a support part is provided on the opposite side to the object side (second direction side) of the module cover 310 and the pressing member 350 is provided on the object side (first direction side). Therefore, when the photographing unit 1 is inserted in the inside of the module cover 310 , the end part on the opposite side (second direction side) to the object side of the photographing unit 1 is supported by the support member 330 . Further, after the pressing member 350 is attached, the end part on the object side (first direction side) of the photographing unit 1 is supported by the pressing member 350 . Therefore, different from a structure in which, after the photographing unit 1 is accommodated in the inside of the module cover 310 , the photographing unit 1 is fixed to the inside of the module cover 310 by adhesion, welding or the like, assembling is easily performed and displacement of the optical axis “L” is hard to be occurred. Accordingly, the production efficiency and yield of the optical unit 100 can be improved.
In addition, after the photographing unit 1 is mounted, only the photographing unit 1 can be exchanged and, when the optical unit 100 is to be manufactured, the photographing unit 1 can be easily changed to another photographing unit 1 .
Further, in this embodiment, the connector 900 (connector members 910 and 920 ) is disposed between the end part on the opposite side (second direction side) to the object side of the photographing unit 1 and the support member 330 . Therefore, the photographing unit 1 and the drive flexible circuit board 420 are electrically connected with each other only by inserting the photographing unit 1 in the inside of the module cover 310 .
Other Embodiments
In the embodiments described above, at least an embodiment of the present invention is applied to the optical unit 100 which is used in a cell phone with a camera. However, at least an embodiment of the present invention may be applied to an optical unit 100 which is used in a thin digital camera or the like. Further, in the embodiments described above, in addition to the lens 10 and the imaging element 155 in the photographing unit 1 , the lens drive mechanism 5 for magnetically driving the movable body 3 including the lens 121 in the optical axis “L” direction is supported on the support body 2 . However, at least an embodiment of the present invention may be applied to a fixed-focus type optical unit in which the lens drive mechanism 5 is not mounted on the photographing unit 1 .
Further, in the embodiments described above, a movable module which is provided with a lens and an imaging element is described as a movable module. However, at least an embodiment of the present invention may be applied to an optical unit which is provided with at least a lens as a movable module. The optical unit includes, for example, a laser pointer, a portable projection display device or an on-vehicle projection display device and the like.
While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.
The presently disclosed 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 the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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Provided is an optical unit comprising a shake detecting sensor which is less likely to unnecessarily vibrate even with the optical unit being designed to have a thinner profile. At a first step in the assembly of an optical unit provided with a shake correction mechanism, a module cover is mounted on a fixed body with a spring member therebetween and a movable module driving mechanism is provided between the module cover and the fixed body. At a second step, an image-capturing unit is inserted into the interior of the module cover by way of a fixed-body-side opening portion and a module-cover-side opening portion, and at a third step, a holding member is attached to a module cover.
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CONTRACTUAL ORIGIN OF THE INVENTION
The U.S. Government has rights in this invention pursuant to Contract No. DE-AC01-79ET15440 between the U.S. Department of Energy and United Technologies Corporation.
BACKGROUND OF THE INVENTION
This invention relates to the production of electrodes for use in molten carbonate fuel cells. In particular it is concerned with anode structures that tend to creep or otherwise distort within the loaded conditions of a fuel cell stack. A typical fuel cell stack for commercial or utility use may contain hundreds of electrodes.
Fuel cells with alkali-metal carbonates as electrolyte are well known and are generally referred to as molten carbonate fuel cells. Such fuel cells and stacks of cells are illustrated and described in U.S. Pat. No. 4,514,475 to Mientek; U.S. Pat. No. 4,411,968 to Reiser et al. and U.S. Pat. No. 4,206,270 to Kunz et al.
Molten carbonate fuel cells have used porous plaques of nickel and nickel alloy as anode structures. These anodes tend to be dimensionally unstable losing thickness by creep distortion within the fuel cell stack. It is well accepted to use chromium additive into the nickel anodes to enhance the structural stability of the plaque. In U.S. Pat. No. 4,239,557 to Thellmann et al., nickel anodes with up to 30 weight percent chromium are disclosed as being thermally stable at elevated temperatures. Typically alloys of at least 10 weight percent chromium are used to stabilize a porous nickel structure for use as a molten carbonate fuel cell anode.
The use of such high levels of chromium in porous nickel anodes not only is expensive but may result in the degeneration of the structure on oxidation of the chromium. Prior efforts to reduce the amount of chromium to less than 5% by weight have resulted in nickel anodes with increased susceptability to creep under fuel cell stack conditions.
Various efforts have been made to stabilize anode structures with low chromium concentrations. Precipitation hardening with elements such as aluminum or titanium in small proportions, solid solution strengthening by impregnating a standard nickel anode with a solution of the strengthening element such as aluminum, copper, tin or chromium and strengthening by second phase dispersed particles, such as CeO 2 or Cr 2 O 3 have been investigated. In some instances promising results have occured. However, in long term operations under simulated fuel cell stack conditions of a hundred hours or more, the initial creep resistance and stability of the anodes have degraded.
Therefore, in view of the above discussion it is an object of the present invention to provide a method of forming a dimensionally stable electrode structure for molten carbonate fuel cell use.
It is further object to provide a method of preparing a porous anode of nickel and chromium that maintains structural stability in extended use under fuel cell stack conditions.
It is also an object to provide an improved method of producing a porous nickel-chromium alloy with a substantially reduced chromium content over that previously required for long-term stability.
In accordance with the present invention, a method is disclosed for forming a dimensionally stable electrode structure for use in a fuel cell with molten alkali metal carbonate as an eletrolyte. A porous plaque of a nickel-chromium alloy with no more than 5 weight percent chromium is prepared. The chromium is selectively oxidized by exposure to a steam-hydrogen gas mixture containing only a minor proportion of hydrogen in respect to a major proportion of steam at a temperature of at least 600° C. but not more than 800° C.
In further aspects of the invention, the cromium in the plaque is selectively oxidized by exposure to a steam-hydrogen gas mixture at a temperature of 700°-800° C. for at least one hour.
In yet other aspects of the invention, the steam-hydrogen gas is provided in mixture with an inert carrier gas.
In another important aspect of the invention, the steam to hydrogen gas mixture is provided in a volumetric ratio of 80/1 to 120/1 preferably in a steam to hydrogen ratio of about 100/1.
In other aspects of the invention, the porous plaque of nickel has a porosity of about 50 to 60%, a composition of about 98% nickel and 2% chromium by weight, and is formed as a nickel-chromium alloy by heat treating a particulate mixture of nickel and chromium metals of similar particle size for about 5-90 minutes at a temperature of about 1000°-1100° C. preferrably about 1050° C. for about 15 minutes.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated in the accompanying drawings wherein:
FIG. 1 is a graph showing creep verses time for anode plaques prepared by different methods.
FIG. 2 shows a graph illustrating anode creep over a longer period of time than that in FIG. 1 for anodes selectively oxidized at different conditions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In one manner of preparing the anode structure of the present invention, an alloy of nickel with low chromium content is formed. Although other methods may be used, powder metallurgical techniques conveniently are selected in preparing the porous anode structure.
Compacted powders of uniformly mixed nickel and chromium in the desired proportions are formed. To promote a uniform mixture, the nickel and chromium particles preferrably are provided of about the same particle size. For example, particles sizes in the range of 1-100 microns can be selected for use.
The compact of mixed nickel and chromium powder is sintered and heat treated at elevated temperature to uniformly diffuse the chromium into the nickel and thereby form a nickel-chromium alloy. It has been found that temperatures of about 1000°-1100° C. for 5-90 minutes, preferrably about 1050° C. for about 15 minutes, can be used to form a uniform alloy of nickel and chromium at about the 1-4% by weight chromium level.
It is of considerable importance that a uniform alloy be formed in order to obtain the uniform and consistent dispersal of the subsequently oxidized chromium particles within the porous nickel structure. Pockets rich in chromium content can result in a weakened structure on oxidation. Conversely portions of the structure devoid in chromium will exhibit poor structural stability.
Anode structures in excess of 50% porosity are desirable to provide adequate sites for contact of electrolyte and fuel gas. Although some densification occurs at the elevated sintering temperatures required to alloy chromium with nickel, anodes of 50-60% porosity and pore sizes of 2 to 10 microns are consistently prepared by powder metallurgical techniques.
The porous plaque of nickel-chromium alloy is exposed to an oxidizing environment of potential sufficient to oxidize chromium without substantial oxidation of nickel. The inventors have found that this oxidation potential should be as high as possible without affecting the nickel structure. It is important to rapidly oxidize the dispersed chromium within the nickel structure before substantial chromium migration occurs to the surfaces of the nickel particles. Excessive oxidation potential will attack the nickel structure, and subsequent reduction to nickel metal in the fuel gas environment does not restore this structural defect. Low oxidizing environments may oxidize surface chromium and establish a steep chromium concentration gradient that may promote chromium migration.
The desired oxygen potential for selectively oxidizing the chromium at a rapid rate in-situ can be provided by carefully managed techniques. In laboratory efforts, a pack of nickel and nickel oxide powder is maintained in contact around the anode structure at elevated temperatures. A nickel-to-nickel oxide ratio of about 1 to 8 by weight can provide a partial pressure of oxygen of suitable oxidizing potential.
In a preferred method, an equilibrium oxygen potential is established by the dissociation of steam at elevated temperatures:
H.sub.2 O⃡H.sub.2 +1/2O.sub.2
The inventors have found that this equilibrium must be biased with the addition of minor amounts of hydrogen gas to the steam to obtain an oxygen potential which will oxidize the chromium in preference to the nickel. In addition, the oxygen potential must be suitable to oxidize the chromium in situ prior to substantial chromium migration. A steam to hydrogen ratio of about 80/1 to 120/1 by volume is suitable for this purpose. Preferably a steam to hydrogen ratio of about 100/1 is selected for use. In some applications an inert carrier gas, of such as nitrogen, may be used in the gas mixture to provide a desired flow rate and gas distribution.
Elevated temperatures are used to internally oxidize the anode with the steam/hydrogen gas mixture. However, it is of considerable importance that substantial oxidation of chromium in the nickel structure be performed with the oxidizing gas at a temperature of 800° C. or below. This limited temperature may retard chromium migration to improve the creep resistance of the completed anode. As will be seen below, in conjunction with FIG. 2, a substantial improvement in creep resistance results at an oxidizing temperature below 800° C. It also will be seen that exposure to temperatures above 800° C. may not adversely affect creep resistance after substantial oxidation has occurred below 800° C.
Although, the minimum oxidizing temperature may vary with conditions, it is expected that a temperature of at least 600° C. is desirable to promote a practical oxidation rate. Accordingly, the nickel structure is oxidized with the steam-hydrogen gas mixture at a temperature of 600°-800° C. Preferably, a temperature of 700°-800° C. is employed.
To illustrate the improvement obtained by the method of this invention, FIGS. 1 and 2 are presented showing thickness reduction or creep for anodes prepared by different methods. FIG. 1 shows the creep record for several anodes over a period of about 70 hours. Creep is expressed in microns of anode thickness reduction.
The anodes of FIG. 1 were prepared by press molding a mixture of about 98% nickel and 2% chromium powder by weight and presintering at about 700° C., to tack the structure together. The temperature then was raised to the sintering temperature and held there for about one hour. One anode was sintered at 910° C., a second at 1070° C. and a third was sintered at 1070° C. The third anode was treated further in a step to internally oxidize the dispersed chromium.
The internal oxidation was conducted by exposing the porous anode structure for about 100 hours to an oxygen atmosphere emitted by a powder pack consisting of about 8 weight parts nickel oxide and 1 weight part nickel metal heated to about 800° C. The anodes with thickness of about 1.6 mm were subjected to static loads of about 7 atmospheres between pressure plates to simulate fuel cell stack conditions. The results shown in FIG. 1 make it clear that after 60 hours only the internally oxidized anode exhibited good creep resistance.
The anodes of FIG. 2 were prepared in a similar manner, and of a similar size to that of the FIG. 1 anodes. However, the chromium was oxidized within the anode structure by exposure to a steam-hydrogen gas mixture of about 100/1 volume ratio. Creep is expressed in microns of thickness reduction.
One anode labeled 760° C. was heated in a 3%H 2 /N 2 gas to thermal equilibrium at 760° C. at which temperature the steam was introduced and maintained in flowing contact with the anode for 24 hours. A second anode labeled 870° C. was heated in a similar manner except that the steam was first introduced at a temperature of 870° C. FIG. 2 shows the excellent creep resistance of the first anode exposed to the oxidizing gas at the lower temperature compared to that of the second anode which suffered a rapid decrease in thickness over time. A third anode in FIG. 2 labeled 760-870C was heated in a manner similar to the other two to 760° C. at which temperature steam was first introduced. The temperature of the anode and oxidizing gas was increased to 870° C. over a period of about 5 hours, and held at that temperature for about 24 hours. FIG. 2 shows that the creep properties of this anode are practically the same as the first anode oxidized isothermally at 760° C., indicating that contact between the oxidizing gas and the anode is necessary at the lower temperature (below about 800° C.) in order to enhance the creep resistance of the anode. This result further indicates that subsequent heating to a temperature in excess of 800° C. does not reverse the beneficial effects achieved from oxidizing at a lower temperature.
From the above it is seen that a substantial improvement in creep resistance of nickel-chromium alloy anodes can be obtained through use of the inventors' preparation procedure. This new procedure permits use of low chromium contents of less than 5 weight percent with good creep characteristics. Improvements in creep resistance are obtained by internally oxidizing only the dispersed chromium at a sufficient rate to achieve in-situ oxidation prior to substantial chromium migration. This is achieved by contacting the anode with an oxidizing gas comprising steam below 800° C. with a minor hydrogen gas addition to retard oxidation of nickel.
Although this invention is described and illustrated with specific materials, process parameters and embodiments, it will be understood by those skilled in the art that variations may be made within the scope of the invention as claimed.
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A method is disclosed for preparing a dimensionally stable electrode structure, particularly nickel-chromium anodes, for use in a molten carbonate fuel cell stack. A low-chromium to nickel alloy is provided and oxidized in a mildly oxidizing gas of sufficient oxidation potential to oxidize chromium in the alloy structure. Typically, a steam/H 2 gas mixture in a ratio of about 100/1 and at a temperature below 800° C. is used as the oxidizing medium. This method permits the use of less than 5 weight percent chromium in nickel alloy electrodes while obtaining good resistance to creep in the electrodes of a fuel cell stack.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH FOR DEVELOPMENT:
[0002] No Federal Funds were used in the development of this Invention.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not Applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC.
[0004] Not Applicable.
BACKGROUND OF THE INVENTION
[0005] There is a great need for a portable thermal bookbinding machine which is as effective as the stationary thermal bookbinding machines now on the market. The invention herein disclosed meets that need in a very effective way. There are other thermal bookbinding systems but portability has heretofore been limited.
FIELD OF THE INVENTION
[0006] Thermal bookbinding machine.
DESCRIPTION OF RELATED ART
[0007] Historical attempts to address some or all of the limitations in prior patented binding machines have been numerous. Examples of relevant art from U.S. Patents are U.S. Pat. Nos. 5,536,044, 5,152,654, 4,385,225, 4,178,201, 4,149,829, 4,141,100, 6,986,631, 6,732,777, 6,641,345, 6,619,900, 5,536,044, 5,536,044, 5,346,350, 5,31,6424, 5,035,561, 4,187,571 and U.S. patent application Ser. No. 4800110. None of these are portable machines as capable of creating high quality bindings of documents as the subject invention.
BRIEF SUMMARY OF THE INVENTION
[0008] This improved thermal document binding machine is designed for the portable binding of documents using thermal heat to melt a hot melt material over the binding, thereby sealing the pages therein.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] FIG. 1 shows a perspective view of an assembled Binding Machine without the Document Stacking Base Housing which can also be used with it.
[0010] FIG. 2 shows an exploded perspective view of the machine with the Left Frame Cover removed and a stack of documents ready to bind in it.
[0011] FIG. 3A shows a perspective view of a stack of documents in the Document Stacking Base Housing anchored together with the Paper Clamp.
[0012] FIG. 3B shows a perspective view of a stack of documents in the Paper Clamp after removal from the Document Stacking Base Housing.
[0013] FIG. 4 shows an exploded perspective view of the machine with a stack of documents already in the Paper Clamp about to be inserted into the Binding Machine.
[0014] FIG. 5 shows a perspective view of the machine with the Thermal Strip placed on the spine of the document about to be heated by the Heater Element.
[0015] FIG. 6 shows a perspective view of the machine with the Heater Element in the closed position over the Hot Strip Material.
[0016] FIG. 7 shows a perspective view of the Heater Element in the open position with the Cooling Element in place over the Hot Melt Strip.
[0017] FIG. 8A shows a perspective view of the bound document removed from the Binding Machine. At that point in the binding process the excess Hot Melt Thermal Strip is cut off or broken off from both sides of the document being bound.
[0018] FIG. 8B shows a close up perspective view of the Thermal Strip Trimmer in use to trim off the excess of the Thermal Strip composed of the Hot Melt Material after binding.
[0019] FIG. 9A shows a bound document in the Document Holder with Binding Tape or clear “Magic” Tape applied to the spine.
[0020] FIG. 9B shows a bound document pushed down into the Document Stacking Base Housing to fold down the Binding Tape or clear “Magic” Tape applied previously to the spine of the document.
[0021] FIG. 10 : Shows a close up perspective view of the Thermal Strip Trimmer used to trim off the excess of the Thermal Strip composed of the Hot Melt material after binding.
[0022] FIG. 11 shows a bound document ready for use.
[0023] FIG. 12 shows a perspective view of another embodiment of the invention using a motor means to open and close the heating and cooling Elements instead of hand actuated levers.
DETAILED DESCRIPTION OF THE INVENTION
[0024] FIG. 1 shows an orthogonal view an assembled Binding Machine without the Document Stacking Base Housing which can also be used with it.
[0025] FIG. 2 shows an exploded perspective view of the machine with the Left Frame Cover ( 61 ) removed and a stack of documents ready to bind in it. A Paper Clamp Assembly comprised of a Front Paper Clamp ( 57 ), a Rear Paper Clamp ( 24 ) Shown in FIG. 2B , a Right Clamp Release Knob ( 58 ) and a Left Clamp Release Knob ( 59 ) holds a sheaf of papers or documents to be bound ( 60 ). The Heater Handle ( 55 ) which lowers the Heater Cover Housing ( 69 ) and the Cooling Element Handle ( 56 ) which raises and lowers the Cooling Element ( 66 ) can also be seen. The Cooling Element Handle ( 56 ) is connected to the Cooling Element ( 66 ) by the Cooling Element Pivot Shaft ( 63 ) in FIG. 4 . The Cooling Element ( 66 ) also known as the Cooling Block in the preferred embodiment is a large block of metallic or other heat resistant material with the ability to act as a heat sink and rapidly diffuse heat from the Hot Melt Material after it has been heated. The Heater Cover Housing ( 69 ) is connected to the Heater Handle ( 55 ) by the left and Right Heating Arm Anchor ( 30 ), which rotates on the Heater Element Pivot Shaft ( 64 ) in FIG. 4 . The Binding Machine sits upon a Right Folding Leg also known as a Right Collapsible Leg ( 61 ) and a Left Folding Leg also known as a Collapsible Leg ( 62 ). The Heater Element ( 67 ) is contained within the Heater Cover Housing ( 69 ). The Heater Cover Housing ( 69 ) in the preferred embodiment has a Left End Cap ( 31 ) and a Right End Cap ( 42 ) and contains a Heater Center Pin ( 68 ), which pivots to allow even pressure to be applied to the document being bound. In the preferred embodiment, the Heater Cover Housing ( 69 ) has a Left End Cap ( 31 and a Right End Cap ( 42 ) at each end. The Cooling Element ( 66 ) in the preferred embodiment, is anchored inside a Cooling Element Cover by two Cooling Arm Anchor Grommets ( 70 ) which anchor the Cooling Element ( 66 ) and the Cooling Element Cover over it to the Cooling Element Pivot Shaft ( 63 ) in FIG. 4 . In the preferred embodiment, a Frame Support Rod ( 29 ) is anchored into place by the Right Frame Cover ( 35 ) on the right side. Also in the preferred embodiment, the Frame Support Rod ( 29 ) is anchored into both the Right Frame Cover ( 35 ) and the Left Frame Cover by a Frame Support Rod Button ( 65 ). The Front Main Frame Shaft ( 26 ) and the Rear Main Shaft ( 25 ) hold the frame together. The Thermal Strip, also known as a Hot Melt Strip, which is made of a Generic Hot Melt Adhesive ( 37 ), which will be fused onto the sheaf of documents ( 60 ), is also shown. The Hot Melt Strip ( 37 ) is placed on top of the Spine Edge of the document to be bound.
[0026] FIG. 3A : Shows a perspective view of a stack of documents ( 60 ) anchored together with a Paper Clamp Assembly. The housing comprising the Document Stacking Base ( 20 ) is shown with a sheaf of documents ( 60 ) being clamped between the Front Paper Clamp ( 57 ) and the Rear Paper Clamp ( 24 ). The Front Paper Clamp ( 57 ) and the Rear Paper Clamp ( 24 ) are kept tight by securing the Right Clamp Release Knob ( 58 ) and the Left Clamp Release Knob ( 59 ). A Right Side Cutter And Tape Guide ( 71 ) and a Left Side Cutter And Tape Guide ( 23 ) in conjunction with the Paper Stopper ( 22 ) assist in keeping the sheaf of documents properly stacked for binding.
[0027] FIG. 3B shows a perspective view of a stack of documents in the Paper Clamp Assembly after removal from the Document Stacking Base Housing ( 20 ) ready to be inserted into the Binding Machine. The Right Clamp Screw ( 27 ) and the Left Clamp Screw ( 28 ) secured and released by the Right Clamp Release Knob ( 58 ) and the Left Clamp Release Knob ( 59 ) via the Right Clamp Post ( 72 ) and Left Clamp Post ( 73 ) are also visible.
[0028] FIG. 4 shows an exploded perspective view of the Binding Machine with a stack of documents already in the Paper Clamp Assembly next to it. A Hot Melt Strip ( 37 ) composed of a generic Hot Melt adhesive material has already been applied to the stack of documents which is about to be inserted into the Binding Machine. In the preferred embodiment, the Front Main Frame Shaft Button ( 32 ), Cooling Element Pivot Shaft Button ( 33 ) Rear Main Frame Shaft Button ( 34 ) and Heater Element Pivot Shaft Button ( 36 ) all anchor into the Left Frame Cover (not shown). They also anchor on the right side into the Right Frame Cover ( 35 ). The Left Side Front Main Frame Shaft Anchor Pin ( 38 ) and Right Side Front Main Frame Shaft Anchor Pin ( 39 ) prevent the 5 Right Folding Leg ( 61 ) and Left Folding Leg ( 62 ) from opening too far when the portable Binding Machine is set up.
[0029] FIG. 5 shows a perspective view of the machine with the Thermal Strip placed on the spine of the book about to be heated by the Heater Element ( 67 ). The Heater Element ( 67 ) is above the Hot Melt Strip ( 37 ) in the open position. The Cooling Element 10 ( 66 ) can also be seen in the open position below the Heater Element ( 67 ).
[0030] FIG. 6 shows a perspective view of the machine with the Heater Element inside the Heater Cover Housing ( 69 ) in the closed position over the Hot Strip material ( 37 ).
[0031] The Heater Element ( 67 ) then heats the Hot Melt Strip, causing the Hot Melt material to flow downward in between the sheets of the document ( 60 ), sealing their ends and 1 5 creating a sealed binding for the documents.
[0032] FIG. 7 shows a perspective view of the Heater Element ( 67 ) in the open position with the Cooling Element ( 66 ) in place over the Hot Melt Strip ( 37 ). The Right Heating Arm Anchor ( 43 ) can be seen next to the Heater Handle ( 55 ).
[0033] FIG. 8A shows a perspective view of the bound document ( 60 ) removed from 20 the Binding Machine. The document is now ready for both ends to have the excess portion of the Hot Melt Thermal Strip to be trimmed off and the Magic Tape Cutoff ( 45 ).
[0034] FIG. 8B shows a close up perspective view of the Thermal Strip Trimmer ( 47 ) in use to trim off the excess of the Thermal Strip composed of the Hot Melt material after binding. The Thermal Strip Trimmer can be seen near the lower part of the view removing a portion of excess Thermal Strip Hot Melt material from the document ( 60 ). A Document Stop ( 46 ) helps keep the document ( 60 ) steady during the trimming process.
[0035] FIG. 9A shows a bound document pushed down into the Document Holder ( 20 ) with Binding Tape or clear “Magic” Tape ( 44 ) applied to the spine. The paperback panel ( 48 ) is used to support the document when it is being prepared for the Binding Tape or Magic Tape ( 44 ) to be applied. It is also used when cutting off the excess Binding Tape or Magic Tape ( 71 ) from both ends of the document being bound. The paperback panel recess ( 49 ) allows the size of the paperback panel ( 48 ) to be adjusted to fit varying sizes of documents to be bound.
[0036] FIG. 9B shows a bound document pushed down into the Document Tape Press Slot ( 40 ) to fold the tape applied previously to the spine.
[0037] FIG. 10 : Shows a close up perspective view of the Thermal Strip Trimmer ( 47 ) used to trim off the excess of the Thermal Strip composed of the Hot Melt material after binding. The Thermal Strip Trimmer is comprised of a Trimmer Housing ( 41 ), a Trimmer Blade ( 53 ) and a Trimmer Blade Stop ( 52 ). The Trimmer is manipulated by the operator using the Trimmer Handle ( 51 ).
[0038] FIG. 11 shows a Bound Document ( 50 ) ready for use.
[0039] FIG. 12 shows a perspective view of another embodiment of the invention using a motor means ( 74 ) to open and close the heating and cooling Elements instead of hand actuated levers. The Front Paper Clamp attached to the Left Clamp Release Knob ( 59 ), the Right Clamp Release Knob ( 58 ), the Document being Bound ( 60 ), and Heater Center Pin ( 68 ), are still visible inside the invention. The motor means and other mechanical parts in this embodiment are enclosed by a Right Side Cover Panel ( 81 ), a Left Side Cover Panel ( 78 ), a Top Panel ( 80 ), and a Sliding Cover ( 76 ) operated by a Sliding Cover Handle ( 75 ). Although the legs do not fold up, the configuration of the frame, heating and cooling means still make this machine very portable.
[0040] Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.
[0041] While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
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A portable thermal document binding machine which uses a strip of thermal hot melt material melted by a heating element, which is then cooled by a cooling element to use gravity to securely seal the documents being bound. A portable trimming board and thermal strip trimmer are used to finish the binding process.
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PRIORITY
This application claims the benefit under 35 U.S.C. §119(a) of a Korean patent application filed on May 3, 2012 in the Korean Intellectual Property Office and assigned Serial No. 10-2012-0047040, the entire disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and device for a Wi-Fi communication system. More specifically, the present invention relates to a method and device that provide content casting services using a Wi-Fi communication system.
2. Description of the Related Art
With recent popularization of terminals or devices supporting Wi-Fi communication or Wireless Local Area Network (WLAN) communication, research has been actively conducted into devices that can provide various services using a WLAN communication system.
In particular, a device may provide a content casting service to another device. For example, a first device may transmit stored content data to a second device such as a Wireless Access Point (WAP) through a first frequency band, and transmit content data to a third device such as a smartphone through a second frequency band. Here, as is widely known, a WAP refers to a device that allows wireless devices to connect to a wired network using Wi-Fi or related standards.
However, an existing device may use only one of a plurality of frequency bands at a particular time to communicate with external devices. In other words, to simultaneously connect to multiple external devices (for example, first and second external devices), an existing device needs to conduct periodic switching between communication channels (actually used frequency bands) at the PHYsical (PHY) layer. For example, the device may receive content data from a first external device (e.g. WAP) through a channel of a first frequency band (e.g. 2.4 GHz) and store the same. The device then switches the PHY layer channel from the first frequency band to a second frequency band (e.g. 5 GHz) and transmits the stored content data to a second external device (e.g. TV) through the second frequency band channel. Then, to connect back to the first external device, the device needs to switch the PHY layer channel from the second frequency band to the first frequency band.
An existing device operating as described above may suffer degradation of maximum available throughput at each frequency band according to loss of throughput due to time division and loss of time due to switching between frequency bands. For example, when the device attempts to transmit a large amount of content data through a 5-GHz band while using Voice over Internet Protocol (VoIP) through a 2.4-GHz band, the amount of content data transmittable through the 5-GHz band may be limited. Additionally, the device may experience loss of time owing to periodic switching between frequency bands at the MAC and PHY layers.
Accordingly, there is a need for a device and method for receiving content data from a first external device through a receive frequency band and simultaneously transmitting the received content data to a second external device through a transmit frequency band.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.
SUMMARY OF THE INVENTION
Aspects of the present invention are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a method and device for providing content casting services.
Another aspect of the present invention is to provide a method and device that receives content data from a first external device through a receive frequency band and transmits the received content data to a second external device through a transmit frequency band at the same time.
Another aspect of the present invention is to provide a method and device that transmit content to external devices through multiple transmit frequency bands.
In accordance with an aspect of the present invention, a method of providing a content casting service in a device having a first band communication module for communicating with external devices over a first frequency band and a second band communication module for communicating with external devices over a second frequency band is provided. The method includes detecting occurrence of a cast request event, indicating content delivery, selecting, upon detection of the cast request event, a first external device possessing the indicated content, receiving the content from the selected first external device through the first band communication module, and transmitting the received content to a second external device through the second band communication module.
In accordance with another aspect of the present invention, a method of providing a content casting service in a device having a first band communication module for communicating with external devices over a first frequency band and a second band communication module for communicating with external devices over a second frequency band is provided. The method includes detecting occurrence of a cast request event indicating content delivery, selecting, upon detection of the cast request event, one of content stored in a storage unit, selecting a first external device and a second external device, transmitting the selected content to the first external device through the first band communication module, and transmitting the selected content to the second external device through the second band communication module.
In accordance with another aspect of the present invention, a method of providing a content casting service in a device having a first band communication module for communicating with external devices over a first frequency band and a second band communication module for communicating with external devices over a second frequency band is provided. The method includes detecting occurrence of a cast request event indicating image delivery, receiving, upon detection of the cast request event, captured images from a first external device through the first band communication module, and transmitting the received captured images to a second external device through the second band communication module.
In accordance with another aspect of the present invention, a device capable of providing a content casting service is provided. The device includes a touchscreen capable of providing a user interface for user interactions, a first band communication module capable of communicating with a first external device over a first frequency band, a second band communication module capable of communicating with a second external device over a second frequency band, wherein the first band communication module and the second band communication module are integrated into one chip, and a control unit capable of controlling the touchscreen, the first band communication module and the second band communication module, wherein the control unit is capable of controlling a process of detecting occurrence of a cast request event indicating content delivery, selecting, upon detection of the cast request event, the first external device possessing the indicated content, receiving the content from the first external device through the first band communication module, and transmitting the received content to the second external device through the second band communication module.
In accordance with another aspect of the present invention, a device capable of providing a content casting service is provided. The device includes a touchscreen capable of providing a user interface for user interaction, a first band communication module capable of communicating with a first external device over a first frequency band, a second band communication module capable of communicating with a second external device over a second frequency band, wherein the first band communication module and the second band communication module are integrated into one chip, and a control unit capable of controlling the touchscreen, the first band communication module and the second band communication module, wherein the control unit is capable of controlling a process of detecting occurrence of a cast request event indicating content delivery, selecting, upon detection of the cast request event, one of content stored in a storage unit, selecting a first external device and second external device, transmitting the selected content to the first external device through the first band communication module, and transmitting the selected content to the second external device through the second band communication module.
In accordance with another aspect of the present invention, a device capable of providing a content casting service is provided. The device includes a touchscreen capable of providing a user interface for user interaction, a first band communication module capable of communicating with a first external device over a first frequency band, a second band communication module capable of communicating with a second external device over a second frequency band, wherein the first band communication module and the second band communication module are integrated into one chip, and a control unit capable of controlling the touchscreen, the first band communication module and the second band communication module, wherein the control unit is capable of controlling a process of detecting occurrence of a cast request event indicating image delivery, receiving, upon detection of the cast request event, captured images from the first external device through the first band communication module, and transmitting the received captured images to the second external device through the second band communication module.
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a block diagram of a device according to an exemplary embodiment of the present invention;
FIG. 2 illustrates a content casting service according to an exemplary embodiment of the present invention;
FIGS. 3 and 4 illustrate a time domain relationship between receive and transmit signals during a content casting service of a device according to an exemplary embodiment of the present invention;
FIG. 5 illustrates a content casting service according to an exemplary embodiment of the present invention;
FIG. 6 illustrates a content casting service according to an exemplary embodiment of the present invention;
FIG. 7 illustrates a content casting service according to an exemplary embodiment of the present invention;
FIG. 8 is a flowchart of a method for providing a content casting service according to an exemplary embodiment of the present invention;
FIGS. 9 to 11 are screen representations depicting steps in the method of FIG. 8 according to exemplary embodiments of the present invention;
FIG. 12 is a flowchart of a method for providing a content casting service according to an exemplary embodiment of the present invention;
FIGS. 13 and 14 are screen representations depicting steps in the method of FIG. 12 according to exemplary embodiments of the present invention;
FIG. 15 is a flowchart of a method for providing a content casting service according to an exemplary embodiment of the present invention;
FIG. 16 illustrates screen representations depicting steps in the method of FIG. 15 according to exemplary embodiments of the present invention;
FIG. 17 is a flowchart of a method for providing a content casting service according to an exemplary embodiment of the present invention;
FIG. 18 illustrates screen representations depicting steps in the method of FIG. 17 according to exemplary embodiments of the present invention;
FIG. 19 illustrates screen representations of a method for providing a content casting service according to exemplary embodiments of the present invention; and
FIG. 20 is a flowchart of a procedure to determine whether to operate in a dual mode or repeater mode according to an exemplary embodiment of the present invention.
Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.
In the following description, the terms “cast” or “casting” may refer to a unicast where a device sends content to one external device, a multicast where a device sends content to multiple external devices belonging to the same group, or a broadcast where a device sends content to multiple unspecified external devices.
The method and device according to exemplary embodiments of the present invention are applicable to terminals with a communication function. That is, the exemplary method and device of the present invention can be applied to communication and multimedia appliances such as a smartphone, a tablet computer, a laptop computer, a desktop computer, a TV, a navigation aid, a videophone, and the like. The exemplary method and device may also be applied to convergence appliances such as a refrigerator having a communication function and a TV.
The description primarily focuses upon the provision of a content casting service using Wireless Local Area Network (WLAN). However, the content casting service may also be provided using a different communication scheme such as Bluetooth. In the following description, only multicasting is described and illustrated. However, it is to be understood that the present invention is also applicable to unicasting or broadcasting.
FIG. 1 is a block diagram of a device according to an exemplary embodiment of the present invention.
Referring to FIG. 1 , the device 100 may include a touchscreen 110 including a touch panel 111 and a display unit 112 , a key input unit 120 , a touch panel controller 125 , a storage unit 130 , an audio processing unit 135 including a speaker (SPK) and microphone (MIC), a first wireless unit 140 , a second wireless unit 145 , and a control unit 180 .
The touch panel 111 may be placed on the display unit 112 . The touch panel 111 generates touch data (e.g. touch event) corresponding to a touch gesture made by the user and sends the touch data to the control unit 180 . The touch panel 111 may be of an add-on type (e.g., placed on the display unit 112 ) or an on-cell or in-cell type (e.g., inserted in the display unit 112 ). The control unit 180 may control other components on the basis of touch data sent by the touch panel 111 . Touch data or a touch event may be divided into a touch action and touch gesture. A touch action may include a touch, a tap, a double tap, a long tap, a drag, a drag and drop, a flick, a press, and the like. Here, a touch corresponds to single point contact with the screen using a touch means such as a finger or stylus pen; a tap corresponds to touch and release at the same point; a double tap corresponds to two consecutive taps at the same point; a long tap corresponds to a long touch and a release at the same point; a drag corresponds to a touch and a move in one direction; a drag and drop corresponds to a drag and a release; a flick corresponds to a touch, a fast move and a release; and a press corresponds to a touch and a push at the same point. Namely, a touch action may be focused on a state of contact on the screen, and a touch gesture may be focused on a movement of a touch action from a contact on the screen to a release from the screen. The touch panel 111 may include a pressure sensor to sense pressure at a touched point. In that case, sensed pressure information is sent to the control unit 180 , which can distinguish a touch from a press on the basis of the sensed pressure information. The touch panel 111 may be realized using a resistive, a capacitive, or an electromagnetic induction technology.
The display unit 112 converts video data from the control unit 180 into an analog signal and displays the analog signal under control of the control unit 180 . The display unit 112 may output various screens generated in the course of using the device 100 , such as a lock screen, a home screen, an application (or app) screen, a menu screen, a keypad screen, a message-handling screen, and an Internet access screen. The lock screen is displayed when the display unit 112 is turned on. When a given touch event for unlocking is generated, the control unit 180 may perform a screen transition from the lock screen to the home screen or a preset app screen. The home screen includes a plurality of icons mapped to various apps. When one of the icons is selected by the user, the control unit 180 may execute an app mapped with the selected icon and control the display unit 112 to display the corresponding application screen. The display unit 112 may be realized using a flat display panel composed of Liquid Crystal Display (LCD) devices, Organic Light Emitting Diodes (OLEDs), or Active Matrix Organic Light Emitting Diodes (AMOLEDs).
The key input unit 120 may include a plurality of alphanumeric and function keys for entering alphanumeric information and for setting various functions. The function keys may include direction, side, and shortcut keys associated with corresponding functions. The key input unit 120 transmits key signals from the user for setting and controlling the device 100 to the control unit 180 . Key signals may be related to power on/off, volume adjustment, and screen on/off. The control unit 180 may control the components according to key signals. The key input unit 120 may include a QWERTY keypad, a 3*4 keypad, or a 4*3 keypad, including multiple keys. When the touch panel 111 is configured to support a full touchscreen feature, the key input unit 120 may include only one or more side keys that are arranged at sides of the case of the device 100 for screen on/off and power on/off.
The touch panel controller 125 is connected to the touch panel 111 . The touch panel controller 125 receives analog touch data from the touch panel 111 , converts the analog touch data into digital touch data, and sends the digital touch data to the control unit 180 . The control unit 180 identifies a touch gesture from the received touch data. That is, the control unit 180 may extract information regarding a touch point, a distance, a direction and speed of the touch and movement, and a touch pressure.
The storage unit 130 may include a high-speed random access memory, nonvolatile memory, optical storage medium, and flash memory (NAND or NOR type). The storage unit 130 stores various kinds of software such as an operating system, a communication program, a graphics program, a user interface program, and other applications. Modules or components of particular software include a set of instructions. The operating system (for example, Windows, Linux, Darwin, RTXC, UNIX, OS X, or VxWorks) includes various software modules for controlling the device 100 . The communication program includes instructions enabling the device 100 to communicate with external devices through the first wireless unit 140 and second wireless unit 145 . More particularly, the communication program may include a routine for determining whether to activate a content casting service on the basis of detected user input, and a routine for actually providing a content casting service. The graphics program includes various components for displaying graphics data on the touchscreen 110 . Here, graphics data may be composed at least one of text, web pages, icons, digital images, video and animation. The graphics program includes a routine for controlling an operation to display graphics data corresponding to a function executed by the control unit 180 on the touchscreen 110 . The user interface program includes various routines for managing interactions between the device 100 and the user. Application programs may perform operations related to Web browsing, electronic mail, instant messaging, word processing, keyboard emulation, address books, widgets, Digital Rights Management (DRM), speech recognition, position determination, location based services, content casting services, and the like. The storage unit 130 may further store other programs or routines, or may not store one or more of programs or routines described above.
The audio processing unit 135 inputs and outputs audio signals for speech recognition, voice reproduction, digital recording, and call processing by means of the speaker and microphone. The audio processing unit 135 outputs an audio signal through the speaker and receives an audio signal through the microphone. The audio processing unit 135 converts audio data from the control unit 180 into an electrical signal and outputs the electrical signal to the speaker, and converts an electrical signal from the microphone into audio data and outputs the audio data to the control unit 180 . The speaker converts an electrical signal from the audio processing unit 135 into a sound wave for output. The microphone converts a sound wave propagated from a sound source such as a person into an electrical signal.
The first wireless unit 140 and the second wireless unit 145 perform communication operations to send and receive signals (e.g. carrying content data) to and from external devices. The first wireless unit 140 may include at least one of a radio frequency transceiver and an optical (e.g. infrared) transceiver. For example, the first wireless unit 140 may support one of Global System for Mobile Communications (GSM) network, Enhanced Data Rates for GSM Evolution (EDGE) network, Code Division Multiple Access (CDMA) network, Wideband Code Division Multiple Access (WCDMA) network, Long Term Evolution (LTE) network, Orthogonal Frequency Division Multiple Access (OFDMA) network, and Bluetooth network.
The second wireless unit 145 supports Wi-Fi communication. The second wireless unit 145 may include a first band communication module 150 and a second band communication module 160 that are physically separated to send and receive signals using different frequency bands. For example, the first band communication module 150 and second band communication module 160 may respectively support 2.4 GHz and 5 GHz, and may support other frequency bands according to design. The first band communication module 150 and second band communication module 160 may each include an RF section, a PHY layer, and a MAC layer. Hence, the second wireless unit 145 may receive a signal through a first frequency band and send a signal through a second frequency band at the same time. The second wireless unit 145 may simultaneously receive signals or simultaneously send signals through a first frequency band and a second frequency band at the same time. The frequency bands (for example, 2.4 GHz and 5 GHz) supported respectively by the first band communication module 150 and second band communication module 160 may be independent of one another. Thereby, interference between receive and transmit signals can be avoided and RF performance degradation can be prevented.
The first band communication module 150 may include a first RF section 151 , a first PHY layer 152 , a first MAC layer 153 and a first antenna 154 to process a first frequency band signal. The second band communication module 160 may include a second RF section 161 , a second PHY layer 162 , a second MAC layer 163 and a second antenna 164 to process a second frequency band signal.
The first band communication module 150 and the second band communication module 160 may be configured as physically separate entities in the same chip. That is, a signal received by the first antenna 154 is delivered through the first RF section 151 , first PHY layer 152 and first MAC layer 153 to an application processor 181 ; and a transmit signal from the application processor 181 is delivered through the first MAC layer 153 , first PHY layer 152 and first RF section 151 to the first antenna 154 . A signal received by the second antenna 164 is delivered through the second RF section 161 , second PHY layer 162 and second MAC layer 163 to the application processor 181 ; and a transmit signal from the application processor 181 is delivered through the second MAC layer 163 , second PHY layer 162 and second RF section 161 to the second antenna 164 . Under control of the application processor 181 , the first band communication module 150 and the second band communication module 160 may receive signals at the same time; the first band communication module 150 and the second band communication module 160 may transmit signals at the same time; the first band communication module 150 may receive a signal and the second band communication module 160 may transmit a signal at the same time; or the first band communication module 150 may transmit a signal and the second band communication module 160 may receive a signal at the same time.
The first frequency band (for example, 2.4 GHz) supported by the first band communication module 150 and the second frequency band (for example, 5 GHz) supported by the second band communication module 160 may not overlap with each other. Hence, interference between a first frequency band signal and a second frequency band signal can be avoided, preventing RF performance degradation.
The first RF section 151 (the second RF section 161 ) receives an RF signal from the first antenna 154 (the second antenna 164 ), converts the RF signal into a baseband signal, and outputs the baseband signal to the first PHY layer 152 (the second PHY layer 162 ). The first RF section 151 (the second RF section 161 ) receives a baseband signal from the first PHY layer 152 (the second PHY layer 162 ), converts the baseband signal into an RF signal, and outputs the RF signal to the first antenna 154 (the second antenna 164 ). The first RF section 151 and the second RF section 161 may each include an amplifier, mixer, oscillator, DAC, and filter.
The first PHY layer 152 (the second PHY layer 162 ) may act as a modem for performing conversion between a baseband signal and a bit string according to the physical layer specification of Wi-Fi communication. For example, when Wi-Fi communication employs Orthogonal Frequency Division Multiplexing (OFDM) the first PHY layer 152 (the second PHY layer 162 ) converts a bit string to be sent into complex symbols through coding and modulation, and converts the complex symbols into OFDM symbols through complex symbol-to-subcarrier mapping, Inverse Fast Fourier Transform (IFFT) and Cyclic Prefix (CP) insertion for data transmission. For data reception, the first PHY layer 152 (the second PHY layer 162 ) separates a baseband signal into OFDM symbols, and converts the OFDM symbols into a bit string through subcarrier-to-complex symbol mapping, Fast Fourier Transform (FFT), demodulation, and decoding.
The first MAC layer 153 (the second MAC layer 163 ) may use various communication-related algorithms in relation to network access control (or addressing), channel sharing between multiple nodes (or collision avoidance), packet encryption, fragmentation, power saving mode, and flow control.
In the above description, for signal transmission and reception, the first band communication module 150 and second band communication module 160 are depicted as each having one antenna (i.e. the first antenna 154 or second antenna 164 ). However, the first band communication module 150 and second band communication module 160 may be designed to share a single antenna by employing a diplexer to separate the path of the first RF section 151 from that of the second RF section 161 .
The second wireless unit 145 may further include a third band communication module 170 , which acts similarly to the first and second band communication modules 150 and 160 but uses a different frequency band. The third band communication module 170 may include a third RF section 171 , a third PHY layer 172 , a third MAC layer 173 and a third antenna 174 to process a signal of a second frequency band.
The control unit 180 controls the overall operation of the device 100 , controls signal exchange between the internal components thereof, and performs data processing. The control unit 180 also controls power supply from a battery to other components. The control unit 180 executes an application in response to a touch gesture. To achieve this, the control unit 180 may include the application processor 181 .
The application processor 181 may determine the receive frequency band and the transmit frequency band when a casting request event (e.g., a touch on a “Cast” button on the screen) is detected. For example, the application processor 181 may determine to use a first frequency band and a second frequency band respectively for reception and transmission, or use the first frequency band and the second frequency band respectively for transmission and reception. The first frequency band and the second frequency band may be in the same frequency range of, for example, 2.4 GHz. In this case, the first frequency band and the second frequency band may correspond to non-overlapping orthogonal channels. For example, the first frequency band and the second frequency band may be assigned in the frequency range of 2.4 GHz. In the 2.4 GHz range, 14 channels may be defined (channel bandwidth of 22 MHz and channel separation of 5 MHz), and three non-overlapping channels (Channels 1 , 6 and 11 ) are possible. Then, the first frequency band may be related to Channel 1 and the second frequency band may be related to Channel 6 or 11 . The application processor 181 may determine to use both the first frequency band and the second frequency band for transmission, or use both the first frequency band and the second frequency band for reception.
The application processor 181 may set the receive frequency band and the transmit frequency band to a preset frequency range, or determine the receive frequency band and the transmit frequency band according to a function used in a content casting service and external devices involved in the content casting service. That is, the application processor 181 may determine the receive frequency band and the transmit frequency band in consideration of frequencies used by an executed function or supported by external devices during a content casting service. For example, when a Web browsing function and a display function are used in a content casting service, the application processor 181 may determine the receive frequency band and the transmit frequency band according to frequencies used by the Web browsing function and the display function. Here, the device 100 may execute the Web browsing function to receive Web pages through an external device such as a wireless Access Point (AP), and execute the display function to display content on an external device such as a TV by sending content data (e.g. received Web pages) to the external device. For another example, when the device 100 is already connected with an access point, to initiate a content casting service, the application processor 181 may determine the receive frequency band and the transmit frequency band in consideration of a frequency band used to connect to the access point. Here, the receive frequency band may be set to the frequency band used to connect to the access point, and the transmit frequency band may be set to a different frequency band.
The application processor 181 controls an operation to receive content through the first band communication module 150 and send the received content through the second band communication module 160 at the same time. The application processor 181 may determine to operate in a dual mode or a repeater mode according to characteristics of the current content casting service. In the repeater mode, content received by the first band communication module 150 is forwarded directly to the second band communication module 160 (the application processor 181 is bypassed). In the dual mode, content received by the first band communication module 150 is sent to the application processor 181 , which processes the content (for example, resolution adjustment or resizing) and forwards the processed content to the second band communication module 160 . The application processor 181 may send content stored in the device 100 to both the first band communication module 150 and second band communication module 160 . The application processor 181 may receive content through both the first band communication module 150 and the second band communication module 160 from the outside.
The exemplary device 100 of the present invention may further include an external port, a vibration motor, a Global Positioning Sensor (GPS) receiver, a camera module, and the like (not shown). With the trend towards digital convergence, it should be apparent that the exemplary device 100 of the present invention may further include a unit comparable to the above-described units, and one unit of the device 100 may be removed or replaced with another unit.
FIG. 2 illustrates a content casting service according to an exemplary embodiment of the present invention.
In the following description, a “main owner” refers to a device that casts content to other devices. A “contents group” refers to one or more devices that are capable of providing content to the main owner. A “casting group” refers to one or more devices that receive content from the main owner. One or more casting groups may be present according to frequency bands. For example, a casting group communicating with the main owner through a first frequency band may be referred to as a first casting group, and a casting group communicating with the main owner through a second frequency band may be referred to as a second casting group. The contents group may communicate with the main owner through a frequency band not used by the casting group.
Referring to FIG. 2 , a main owner 210 may include the above-described components 181 , 150 and 160 . The main owner 210 may connect to an access point through the first band communication module 150 . After being connected to the access point, the main owner 210 may detect a user input for connecting to a contents group 220 (for example, selection of a YouTube icon on the touchscreen). Here, the contents group 220 may include a cloud server, a Social Networking Service (SNS) server such as Twitter or Facebook, a moving image database server such as YouTube, and the like. In response to a user input, the main owner 210 may connect to an external device in the contents group 220 through the access point, receive content from the external device, and play back the received content in real time.
The main owner 210 may connect to a casting group 230 through the second band communication module 160 . Here, the second band communication module 160 may directly connect to the casting group 230 without an intermediate medium such as an access point. Direct connection between the main owner 210 and casting group 230 may be achieved using, for example, Wi-Fi Direct. As Wi-Fi Direct is known in the art, a detailed description thereof is omitted herein.
When the user enters an input for a content casting service (for example, touch on the “Cast” button on the touchscreen), the main owner 210 may transmit the content received from the external device of the contents group 220 to the casting group 230 .
As described above, the main owner 210 may receive content from the contents group 220 through the access point and transmit the received content to the casting group 230 . In FIG. 2 , the user may use a smartphone (main owner 210 ) to view a moving image received from YouTube (contents group 220 ) and share the moving image with nearby friends (casting group 230 ). Hence, the user may view and enjoy a moving image together with friends.
The main owner 210 may determine whether to operate in a repeater mode 240 or dual mode 250 . For example, when content is a document file or a compressed file, the main owner 210 may determine to operate in the repeater mode 240 . On the other hand, when content is a moving image, the main owner 210 may determine to operate in the dual mode 250 . In the repeater mode 240 , the main owner 210 uses the first band communication module 150 to receive content through the access point and uses the second band communication module 160 to transmit the received content in real time. In the dual mode 250 , the main owner 210 uses the first band communication module 150 to receive content through the access point, processes the received content through the application processor 181 (for example, resolution adjustment or resizing) and uses the second band communication module 160 to transmit the processed content in real time. In the dual mode 250 , the content delivered to the casting group 230 may be content received through the access point, or be content generated by or stored in the main owner 210 (for example, camera-captured images).
FIGS. 3 and 4 illustrate a time domain relationship between receive and transmit signals during a content casting service of a device according to an exemplary embodiment of the present invention.
Referring to FIGS. 3 and 4 , since the main owner 210 includes the two communication modules 150 and 160 that operate independently on different frequency bands within the same chip as described in connection with FIG. 2 , the main owner 210 may simultaneously receive content from the contents group 220 and transmit the received content to the casting group 230 . Hence, as shown in FIG. 3 , the device 100 does not need a separate switching time for receiving content and transmitting the received content, and can simultaneously perform content reception as indicated by reference numeral 300 or 302 and content transmission as indicated by reference numeral 310 or 312 . As content reception and content transmission are simultaneously performed (without time delay due to switching between frequency bands), exemplary embodiments of the present invention have an advantage over related art techniques in terms of real-time playback. Delay indicated by reference numeral 320 or 322 in FIG. 3 has no relation to switching between frequency bands, and is merely a time needed for the main owner 210 to transmit content received through the first band communication module 150 from the access point to the casting group 230 through the second band communication module 160 .
When a single host interface is used for communication between the application processor 181 and the communication modules 150 and 160 , the application processor 181 has to alternately communicate with the first band communication module 150 and the second band communication module 160 . In this case, the first band communication module 150 and second band communication module 160 may fragment one transmit or receive frame into multiple packets under control of the application processor 181 . The application processor 181 may alternately communicate with the first band communication module 150 and the second band communication module 160 on the basis of fragmented packets. As shown in FIG. 4 , the application processor 181 may process receive packets indicated by reference numerals 400 , 401 , 402 , 403 and 404 alternately with transmit packets indicated by reference numerals 410 , 411 , 412 , 413 and 414 . As the application processor 181 does not have to switch between frequency bands at the MAC or PHY layer (no time delay due to switching between frequency bands), exemplary embodiments of the present invention are more advantageous to real-time playback in comparison to a related art technique.
FIG. 5 illustrates a content casting service according to an exemplary embodiment of the present invention.
Referring to FIG. 5 , a main owner 510 may include the above-described components 181 , 150 and 160 . The main owner 510 may simultaneously receive content from a contents group 520 through the first band communication module 150 and an access point and transmit the received content to a casting group 530 . In FIG. 5 , the main owner 510 is a home network server. The casting group 530 includes user appliances connected to the home network. Such home network appliances may be connected with the home network server using Wi-Fi Direct techniques. The home network appliances may include a smartphone, a TV, a tablet computer, a laptop computer, a refrigerator having a TV, and the like.
FIG. 6 illustrates a content casting service according to an exemplary embodiment of the present invention.
Referring to FIG. 6 , a main owner 610 may include the above-described components 181 , 150 and 160 . The main owner 610 may connect to an access point through the first band communication module 150 , and connect to a second casting group 630 through the access point. The main owner 610 may also connect to a first casting group 620 through the second band communication module 160 . Here, the main owner 610 may connect directly to the first casting group 620 through, for example, Wi-Fi Direct. Thereafter, the main owner 610 may detect a user input requesting a content casting service (for example, a tap on a “Cast” button of a music player application screen).
In response to the user input, the main owner 610 may display information regarding the first casting group 620 and the second casting group 630 . The information on the first casting group 620 may include identification information of external devices within the first casting group 620 (for example, phone numbers, user names, user images, device names, and the like). Here, the identification information may include information that is received by the main owner 610 from external devices of the first casting group 620 during connection establishment. The identification information may also include information pre-stored in the main owner 610 (for example, phonebook information). The information on the second casting group 630 may include identification information of external devices within the second casting group 630 .
When the user selects external devices from the first casting group information and the second casting group information displayed on the screen, the main owner 610 transmits the current content (for example, a music file being played back) to the selected external devices of the second casting group 630 through the first band communication module 150 and transmits the current content to the selected external devices of the first casting group 620 through the second band communication module 160 . In FIG. 6 , the user may listen to music played back by the smartphone (main owner 610 ) and allow both nearby friends (first casting group 620 ) and friends at a distance (second casting group 630 ) to listen to music in real time. In other cases, the user may allow nearby friends and friends at a distance to view images being captured by the smartphone in real time. Also, the user may allow nearby friends and friends at a distance to hear the speech of a counterpart in a call in real time.
In the above description, the device 100 is depicted as having two physically separated communication modules to support two frequency bands. If necessary, an exemplary device of the present invention may include three or more physically separated communication modules to support three or more frequency bands.
FIG. 7 illustrates a content casting service according to an exemplary embodiment of the present invention.
Referring to FIG. 7 , a main owner 710 may include the above described components 181 , 150 and 160 and may further include the third band communication module 170 supporting a third frequency band. The main owner 710 may connect to a contents group 720 through the first band communication module 150 . Here, the contents group 720 is composed of accessories that are directly connectable to the main owner 710 through, for example, Wi-Fi Direct (such as a camera, a CCTV, a remote-controllable miniature car or helicopter with a camera, and the like). The main owner 710 may play back, in real-time, content received through the first band communication module 150 from the contents group 720 (for example, images captured from a miniature helicopter).
The main owner 710 may directly connect to a first casting group 730 through the second band communication module 160 . The main owner 710 may connect to an access point through the third band communication module 170 and connect to a second casting group 740 through the access point. Thereafter, the main owner 710 may detect a user input requesting a content casting service (for example, a touch on a “Cast” button of a captured image screen).
In response to the user input, the main owner 710 may display information regarding the first casting group 730 and the second casting group 740 . When the user selects external devices from the first casting group information and the second casting group information displayed on the screen, the main owner 710 transmits content received from the contents group 720 to the first casting group 730 through the second band communication module 160 and transmits the content to the second casting group 740 through the third band communication module 170 .
FIG. 8 is a flowchart of a method for providing a content casting service according to an exemplary embodiment of the present invention, and FIGS. 9 to 11 are screen representations depicting steps in the method of FIG. 8 according to exemplary embodiments of the present invention.
Referring to FIGS. 1 and 8 to 11 , the control unit 180 of the device 100 may control the display unit 112 to display a home screen. When an icon associated with a chatting application is selected on the home screen (for example, a tap on the icon), the control unit 180 executes a chatting application associated with the selected icon in step 801 . The control unit 180 may control the touchscreen 110 to display a chatting application screen as indicated by reference numeral 901 in FIG. 9 .
The control unit 180 detects a touch input on the chatting application screen 901 in step 802 . For example, the control unit 180 may detect selection of a first object 902 associated with an option menu on the chatting application screen 901 (e.g., a touch on the first object 902 ). Upon selection of the first object 902 , the control unit 180 controls the touchscreen 110 to display an option menu 903 .
The control unit 180 determines whether a cast request event is detected in step 803 . When a cast request event is detected (for example, when a second object 904 (a cast music object) associated with content casting is selected on the option menu 903 ), the control unit 180 controls the touchscreen 110 to display a playlist 905 in step 804 .
The control unit 180 selects music to be cast from the playlist 905 according to a user manipulation in step 805 . After music selection, the control unit 180 controls the first band communication module 150 and the second band communication module 160 to transmit the selected music (content) to external devices connected respectively therewith (for example, first and second external devices) in step 806 .
More specifically for step 806 , when music to be cast is selected, as shown in FIG. 10 , the control unit 180 controls the touchscreen 110 to display a message 1001 notifying of initiation of music casting in a chat window. The control unit 180 controls the first band communication module 150 to send a cast invite message to the first casting group. The first band communication module 150 may be directly connected to the first casting group by means of, for example, Wi-Fi Direct without an intermediate medium such as an access point under control of the control unit 180 . Alternatively, the first band communication module 150 may be connected to the first casting group through an access point.
The control unit 180 controls the second band communication module 160 to send a cast invite message to the second casting group. Here, the second band communication module 160 may be directly connected to the second casting group without an access point or be connected thereto through an access point.
The control unit 180 may control an operation to send cast invite messages according to a preset priority. For example, when the first band communication module 150 is actively engaged in communication, the control unit 180 may control the second band communication module 160 to send a cast invite message to the second casting group first and then control the first band communication module 150 to send a cast invite message to the first casting group. When the first band communication module 150 and the second band communication module 160 are both available, that is, not engaged in communication, the control unit 180 may control the first band communication module 150 to send a cast invite message to the first casting group first and then control the second band communication module 160 to send a cast invite message to the second casting group.
A cast invite message 1002 is displayed in a chat window of the first casting group. A cast invite message 1003 is displayed on a chat window of the second casting group. A first external device of the first casting group may detect selection of a “Join” button in response to the cast invite message 1002 . Upon selection of the “Join” button, the first external device sends a cast join message to the device 100 (main owner). When a second external device of the second casting group detects selection of a “Join” button in response to the cast invite message 1003 , it sends a cast join message to the device 100 .
As shown in FIG. 11 , the control unit 180 controls the touchscreen 110 to display a cast wait message 1101 . When cast join messages are received from the first and second casting groups, the control unit 180 controls the touchscreen 110 to display a music cast screen 1102 . The control unit 180 sends the selected music data to the first casting group through the first band communication module 150 , and sends the music data to the second casting group through the second band communication module 160 . After sending a cast join message to the device 100 , the first external device of the first casting group displays a cast wait message 1103 . When music data is received from the device 100 , the first external device displays a music cast screen 1104 and plays back the received music data. After sending a cast join message to the device 100 , the second external device of the second casting group displays a cast wait message 1105 . When music data is received from the device 100 , the second external device displays a music cast screen 1106 and plays back the received music data. Among the music cast screens 1102 , 1104 and 1106 , the music cast screen 1102 of the device 100 may include buttons 1107 and 1108 for controlling music playback. The user may add or delete music to be cast using such buttons.
As described above in connection with FIGS. 1 and 8 to 11 , the user may introduce favorite content such as music to acquaintances nearby or far away during a chat session.
FIG. 12 is a flowchart of a method for providing a content casting service according to an exemplary embodiment of the present invention, and FIGS. 13 and 14 are screen representations depicting steps in the method of FIG. 12 according to exemplary embodiments of the present invention.
Referring to FIGS. 1 and 12 to 14 , the control unit 180 of the device 100 executes an SNS application according to a user selection (for example, a tap on an icon mapped to the SNS application on the home screen) in step 1201 . The control unit 180 may control the touchscreen 110 to display an SNS application screen 1301 .
The control unit 180 detects a touch input on the SNS application screen 1301 in step 1202 . For example, the control unit 180 may detect selection of a first object 1302 associated with an option menu on the SNS application screen 1301 (e.g. a touch on the first object 1302 ). Upon selection of the first object 1302 , the control unit 180 controls the touchscreen 110 to display an option menu 1303 .
The control unit 180 determines whether a cast request event is detected in step 1203 . When a cast request event is detected (for example, when a second object 1304 (a cast music object) associated with content casting is selected on the option menu 1303 ), the control unit 180 controls the touchscreen 110 to display a playlist 1305 in step 1204 .
The control unit 180 selects music to be cast from the playlist 1305 according to a user manipulation in step 1205 . After music selection, the control unit 180 determines recipient devices to receive music (for example, first and second external devices) in step 1206 .
More specifically for step 1206 , when music to be cast is selected from the playlist 1305 , the control unit 180 controls the touchscreen 110 to display first casting group information 1401 and second casting group information 1402 . Here, the first casting group information 1401 includes identification information of external devices connected with, for example, the first band communication module 150 of the device 100 . The identification information may include photographs and names of users of the external devices. The identification information may be information received from the external devices or information pre-stored in the device 100 . The external devices may be directly connected to the first band communication module 150 without an access point or be connected thereto through an access point. The second casting group information 1402 may be displayed when, for example, the second band communication module 160 of the device 100 is connected to an access point. The second casting group information 1402 may be not displayed when the device 100 is not connected with an access point. The second casting group information 1402 may be obtained from contact information stored in the storage unit 130 . When the user selects external devices from the displayed first casting group information 1401 and second casting group information 1402 , the control unit 180 determines the selected external devices as recipient devices to receive content (music).
The control unit 180 controls the first band communication module 150 and the second band communication module 160 to transmit the selected content (music) to the recipient devices (for example, a first external device connected with the first band communication module 150 and a second external device connected with the second band communication module 160 ) in step 1207 .
More specifically for step 1207 , when an “Invite” button 1403 is selected, the control unit 180 controls the first band communication module 150 to send a cast invite message to a selected external device of the first casting group. The first band communication module 150 may be directly connected to the first casting group or be connected thereto through an access point under control of the control unit 180 . In addition, the control unit 180 controls the second band communication module 160 to send a cast invite message to a selected external device of the second casting group. The second band communication module 160 may be directly connected to the second casting group or be connected thereto through an access point under control of the control unit 180 . As described before, the control unit 180 may send cast invite messages according to a preset priority.
The selected external device of the first casting group displays a cast invite message 1404 . The selected external device of the second casting group displays a cast invite message 1405 . When a “Join” button is selected on the cast invite message 1404 , the external device of the first casting group sends a cast join message to the device 100 . When a “Join” button is selected on the cast invite message 1405 , the external device of the second casting group sends a cast join message to the device 100 . Subsequent steps are substantially the same as described in connection with FIG. 11 , and a description thereof is omitted.
As described above in connection with FIGS. 1 and 12 to 14 , the user may introduce favorite content such as music to acquaintances nearby or far away during an SNS session.
FIG. 15 is a flowchart of a method for providing a content casting service according to an exemplary embodiment of the present invention, and FIG. 16 illustrates representations depicting steps in the method of FIG. 15 according to exemplary embodiments of the present invention.
Referring to FIGS. 1, 15 and 16 , the control unit 180 of the device 100 may control the display unit 112 to display a home screen. Here, the home screen may include icons associated with playback applications for stored content (for example, a music player and video player). When an icon is selected (for example, a tap on the icon), the control unit 180 executes a content playback application associated with the selected icon and controls the touchscreen 110 to display a content playback screen 1601 correspondingly in step 1501 . When a “Play” button 1608 on the content playback screen 1601 is selected, the control unit 180 plays back content (e.g. music). Here, the content may be the last one played back by the corresponding application or one selected by the user from a playlist.
The control unit 180 detects a touch input on the content playback screen 1601 in step 1502 . The control unit 180 determines whether the touch input is a cast request event in step 1503 . For example, when a “Cast” button is selected on the content playback screen 1601 , the control unit 180 determines recipient devices to receive content (music) (for example, first and second external devices) in step 1504 . More specifically for step 1504 , when the “Cast” button 1602 is selected, the control unit 180 controls the touchscreen 110 to display first casting group information 1603 and second casting group information 1604 . When the user selects external devices from the displayed first casting group information 1603 and second casting group information 1604 , the control unit 180 determines the selected external devices as recipient devices to receive content (music).
The control unit 180 controls the first band communication module 150 and the second band communication module 160 to transmit the content (music) to the recipient devices (for example, a first external device connected with the first band communication module 150 and a second external device connected with the second band communication module 160 ) in step 1505 . More specifically, in step 1505 , when an “Invite” button 1605 is selected, the control unit 180 controls the first band communication module 150 to send a cast invite message to a selected external device of the first casting group. In addition, the control unit 180 controls the second band communication module 160 to send a cast invite message to a selected external device of the second casting group. As described before, the control unit 180 may send cast invite messages according to a preset priority. Accordingly, the selected external device of the first casting group displays a cast invite message 1606 . The selected external device of the second casting group displays a cast invite message 1607 . When a “Join” button is selected on the cast invite message 1606 , the external device of the first casting group sends a cast join message to the device 100 . When a “Join” button is selected on the cast invite message 1607 , the external device of the second casting group sends a cast join message to the device 100 . Subsequent steps are substantially the same as described in connection with FIG. 11 , and a description thereof is omitted.
As described above in connection with FIGS. 1, 15 and 16 , the user listening to music using a player application on the smartphone may introduce the music to acquaintances nearby or far away.
FIG. 17 is a flowchart of a method for providing a content casting service according to an exemplary embodiment of the present invention, and FIG. 18 illustrates screen representations depicting steps in the method of FIG. 17 according to exemplary embodiments of the present invention.
Referring to FIGS. 1, 17 and 18 , the control unit 180 of the device 100 may control the display unit 112 to display a home screen. Here, the home screen may include icons associated with streaming applications such as a music player, a video player, a mobile browser, and the like. When an icon is selected (for example, the icon is tapped), the control unit 180 executes a streaming application associated with the selected icon and controls the touchscreen 110 to display a streaming application screen 1801 correspondingly in step 1701 .
The control unit 180 controls the first band communication module 150 to connect to a first external device providing a streaming service (for example, a YouTube server) in step 1702 . Here, the first band communication module 150 may connect to the first external device through an access point. The control unit 180 may control the first band communication module 150 to download content (e.g. moving image or music) from the first external device and control the touchscreen 110 to play back the downloaded content in real time.
The control unit 180 detects a touch input on the streaming application screen 1801 in step 1703 . The control unit 180 determines whether the touch input is a cast request event in step 1704 . For example, when a “Cast” button 1802 is selected on the streaming application screen 1801 , the control unit 180 determines recipient devices to receive content (for example, second external device) among external devices connected with the second band communication module 160 in step 1705 .
More specifically for step 1705 , under control of the control unit 180 , the second band communication module 160 may be directly connected with one or more nearby external devices through, for example, Wi-Fi Direct without an intermediate medium such as an access point. The control unit 180 controls the touchscreen 110 to display first casting group information 1803 regarding external devices connected to the second band communication module 160 . The control unit 180 may detect user selection on the first casting group information 1803 . The control unit 180 may control the touchscreen 110 to display second casting group information 1804 . Here, the second casting group information 1804 may be displayed when the third band communication module 170 is connected to an access point. The second casting group information 1804 may be not displayed when the third band communication module 170 is not connected to an access point. The second casting group information 1804 may be, for example, contact information stored in the storage unit 130 . The control unit 180 may detect a user selection on the second casting group information 1804 . When an “Invite” button 1805 is selected, the control unit 180 controls the second band communication module 160 to send a cast invite message to a selected external device of the first casting group. In addition, the control unit 180 controls the third band communication module 170 to send a cast invite message to a selected external device of the second casting group. Accordingly, the selected external device of the first casting group displays a cast invite message 1806 . The selected external device of the second casting group displays a cast invite message 1807 . When a “Join” button is selected on the cast invite message 1806 , the external device of the first casting group sends a cast join message to the device 100 . When a “Join” button is selected on the cast invite message 1807 , the external device of the second casting group sends a cast join message to the device 100 . The control unit 180 determines the external device of the first casting group having sent a cast join message (a second external device) as a recipient device to receive content. The control unit 180 determines the external device of the second casting group having sent a cast join message (a third external device) as a recipient device to receive content.
After determining recipient devices, the control unit 180 controls the first band communication module 150 to receive streaming content (e.g. moving images or music) from the first external device in step 1706 . The control unit 180 plays back the received streaming content, and transmits the streaming content to the second external device through the second band communication module 160 in step 1707 . The control unit 180 may also transmit the received streaming content to the third external device through the third band communication module 170 .
As described above in connection with FIGS. 1, 17 and 18 , the user viewing, for example, a YouTube video using a moving image player on the smartphone may introduce the video to acquaintances nearby or far away.
FIG. 19 illustrates screen representations of a method for providing a content casting service according to exemplary embodiments of the present invention.
Referring to FIGS. 1 and 19 , the control unit 180 of the device 100 may control the touchscreen 110 to display a camera application screen 1901 . For example, the control unit 180 may activate a camera module and display images captured by the camera module on the touchscreen 110 . For another example, the control unit 180 may control the first band communication module 150 to connect to an accessory (e.g. a miniature helicopter that has a Wi-Fi Direct capability and a camera module and that is controlled remotely by the control unit 180 ) and receive captured images from the accessory, and control the touchscreen 110 to display the received images.
When a “Cast” button 1902 is selected on the camera application screen 1901 , the control unit 180 controls the touchscreen 110 to display first casting group information 1903 and second casting group information 1904 .
The user may select external devices from the displayed first casting group information 1903 and second casting group information 1904 . When an “Invite” button 1905 is selected, the control unit 180 controls the second band communication module 160 to send a cast invite message to a selected external device of the first casting group. In addition, the control unit 180 controls the third band communication module 170 to send a cast invite message to a selected external device of the second casting group. Accordingly, the selected external device of the first casting group displays a cast invite message 1906 . The selected external device of the second casting group displays a cast invite message 1907 . Subsequent steps are substantially the same as described in connection with FIG. 11 , and a description thereof is omitted.
As described above in connection with FIGS. 1 and 19 , the user viewing moving images captured by a camera module installed in the smartphone or an external accessory may introduce the moving images to acquaintances nearby or far away.
FIG. 20 is a flowchart of a procedure to determine whether to operate in a dual mode or repeater mode according to an exemplary embodiment of the present invention.
Referring to FIGS. 1 and 20 , the control unit 180 of the device 100 controls the first band communication module 150 supporting a receive frequency band to receive content from a first external device (such as a YouTube server) in step 2001 . The control unit 180 determines an operating mode for a content casting service in step 2003 . The operating mode may be determined in consideration of the type of the received content. For example, when the received content is a document file or a compressed file, the operating mode may be set to a repeater mode. When the received content is a moving image, the operating mode may be set to a dual mode.
When the operating mode is determined to be a repeater mode, the control unit 180 controls the second band communication module 160 to send the received content to a second external device in step 2005 . When the operating mode is determined to be a dual mode, the control unit 180 processes the content received through the first band communication module 150 (for example, resolution adjustment) in step 2007 , and controls the second band communication module 160 to send the processed content to a second external device in step 2009 .
In an exemplary feature of the present invention, a method and device that support content casting services are provided. Content data may be received from a first external device through a receive frequency band and be transmitted to a second external device through a transmit frequency band at the same time. Content can be simultaneously transmitted to external devices through multiple transmit frequency bands.
The exemplary methods of the present invention may be implemented as computer programs and may be stored in various computer readable storage media. The computer readable storage media may store program instructions, data files, data structures and combinations thereof. The program instructions may include instructions developed specifically for the present invention and existing general-purpose instructions. The computer readable storage media may include magnetic media such as a hard disk and floppy disk, optical media such as a CD-ROM and DVD, magneto-optical media such as a floptical disk, and memory devices such as a ROM and RAM. The program instructions may include machine codes produced by compilers and high-level language codes executable through interpreters. Each hardware device may be replaced with one or more software modules to perform operations according to the present invention, and vice versa.
While the invention has been shown and described with reference to certain exemplary 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 and their equivalents.
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A method and device for content casting services using Wi-Fi communication are disclosed are provided. The device includes a first band communication module for communicating with external devices over a first frequency band and a second band communication module for communicating with external devices over a second frequency band. The method includes detecting occurrence of a cast request event indicating content delivery, selecting, upon detection of the cast request event, a first external device possessing the indicated content, receiving the content from the selected first external device through the first band communication module, and transmitting the received content to a second external device through the second band communication module.
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RELATED APPLICATION INFORMATION
This patent is a continuation of application Ser. No. 12/870,729, entitled FLOW STATISTICS AGGREGATION, filed Aug. 27, 2010.
NOTICE OF COPYRIGHTS AND TRADE DRESS
A portion of the disclosure of this patent document contains material which is subject to copyright protection. This patent document may show and/or describe matter which is or may become trade dress of the owner. The copyright and trade dress owner has no objection to the facsimile reproduction by anyone of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright and trade dress rights whatsoever.
BACKGROUND
1. Field
This disclosure relates to generating and receiving traffic for testing a network or network device.
2. Description of the Related Art
In many types of communications networks, each message to be sent is divided into portions of fixed or variable length. Each portion may be referred to as a packet, a frame, a cell, a datagram, a data unit, or other unit of information, all of which are referred to herein as packets.
Each packet contains a portion of an original message, commonly called the payload of the packet. The payload of a packet may contain data, or may contain voice or video information. The payload of a packet may also contain network management and control information. In addition, each packet contains identification and routing information, commonly called a packet header. The packets are sent individually over the network through multiple switches or nodes. The packets are reassembled into the message at a final destination using the information contained in the packet headers, before the message is delivered to a target device or end user. At the receiving end, the reassembled message is passed to the end user in a format compatible with the user's equipment.
Communications networks that transmit messages as packets are called packet switched networks. Packet switched networks commonly contain a mesh of transmission paths which intersect at hubs or nodes. At least some of the nodes may include a switching device or router that receives packets arriving at the node and retransmits the packets along appropriate outgoing paths. Packet switched networks are governed by a layered structure of industry-standard protocols.
In order to test a packet switched network or a device included in a packet switched communications network, test traffic comprising a large number of packets may be generated, transmitted into the network at one or more ports, and received at different ports. Each packet in the test traffic may be a unicast packet intended for reception at a specific destination port or a multicast packet, which may be intended for reception at two or more destination ports. In this context, the term “port” refers to a communications connection between the network and the equipment used to test the network. The term “port unit” refers to a module with the network test equipment that connects to the network at a port. The received test traffic may be analyzed to measure the performance of the network. Each port unit connected to the network may be both a source of test traffic and a destination for test traffic. Each port unit may emulate a plurality of logical source or destination addresses. The number of port units and the communications paths that connect the port units to the network are typically fixed for the duration of a test session. The internal structure of the network may change during a test session, for example due to failure of a communications path or hardware device.
A series of packets originating from a single port unit and having a specific type of packet and a specific rate will be referred to herein as a “stream.” A source port unit may support multiple concurrent outgoing streams, for example to accommodate multiple packet types, rates, or destinations. “Simultaneous” means “at exactly the same time.” “Concurrent” means “within the same time.”
The test traffic may be divided into a plurality of “traffic items”, where each traffic item is effectively a separate test from each other traffic item. Test traffic for some or all of a plurality of traffic items may be generated and transmitted concurrently. Each traffic items may include a plurality of streams, and each stream may typically be a portion of a single traffic item.
For the purpose of collecting test data, the test traffic for each traffic item may be organized into packet groups, where a “packet group” is any plurality of packets for which network traffic statistics are accumulated. The packets in a given packet group may be distinguished by a packet group identifier (PGID) contained in each packet. The PGID may be, for example, a dedicated identifier field or combination of two or more fields within each packet.
For the purpose of reporting network traffic data, the test traffic for each traffic item may be organized into flows, where a “flow” is any plurality of packets for which network traffic statistics are reported. Each flow may consist of a single packet group or a small plurality of packet groups. Each packet group may typically belong to a single flow.
Within this description, the term “engine” means a collection of hardware, which may be augmented by firmware and/or software, which performs the described functions. An engine may typically be designed using a hardware description language (HDL) that defines the engine primarily in functional terms. The HDL design may be verified using an HDL simulation tool. The verified HDL design may then be converted into a gate netlist or other physical description of the engine in a process commonly termed “synthesis”. The synthesis may be performed automatically using a synthesis tool. The gate netlist or other physical description may be further converted into programming code for implementing the engine in a programmable device such as a field programmable gate array (FPGA), a programmable logic device (PLD), or a programmable logic arrays (PLA). The gate netlist or other physical description may be converted into process instructions and masks for fabricating the engine within an application specific integrated circuit (ASIC).
Within this description, a hardware “unit” also means a collection of hardware, which may be augmented by firmware and/or software, which may be on a larger scale than an “engine”. For example, a unit may contain multiple engines, some of which may perform similar functions in parallel. The terms “engine” and “unit” do not imply any physical separation or demarcation. All or portions of one or more units and/or engines may be collocated on a common card, such as a network card 114 , or within a common FPGA, ASIC, or other circuit device.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a network environment.
FIG. 2 is a block diagram of a port unit.
FIG. 3 is a graphical representation of a packet.
FIG. 4A is a block diagram of a statistics memory.
FIG. 4B is a timing diagram illustrating the operation of the statistics memory of FIG. 4A .
FIG. 5 is a flow chart of a process for designing a network test session.
FIG. 6 a schematic representation of a process for defining PGIDs.
FIG. 7 is a flow chart of a process for testing a network.
FIG. 8 is a flow chart of a first portion of a process for displaying selected test data.
FIG. 9 is a graphical representation of the process for displaying selected test data.
FIG. 10 is a flow chart of a second portion of a process for displaying selected test data.
FIG. 11 is a graphical representation of a graphic user interface for selecting and displaying test data
Throughout this description, elements appearing in block diagrams are assigned three-digit reference designators, where the most significant digit is the figure number and the two least significant digits are specific to the element. An element that is not described in conjunction with a block diagram may be presumed to have the same characteristics and function as a previously-described element having a reference designator with the same least significant digits.
In block diagrams, arrow-terminated lines may indicate data paths rather than signals. Each data path may be multiple bits in width. For example, each data path may consist of 4, 8, 16, 32, 64, or more parallel connections.
DETAILED DESCRIPTION
Description of Apparatus
FIG. 1 shows a block diagram of a network environment. The environment may include network test equipment 100 and a network 190 which may include one or more network device 195 .
The network test equipment 100 may be a network testing device, performance analyzer, conformance validation system, network analyzer, or network management system. The network test equipment 100 may include one or more network cards 114 and a backplane 112 contained or enclosed within a chassis 110 . The chassis 110 may be a fixed or portable chassis, cabinet, or enclosure suitable to contain the network test equipment. The network test equipment 100 may be an integrated unit, as shown in FIG. 1 . Alternatively, the network test equipment 100 may comprise a number of separate units cooperative to provide traffic generation and/or analysis. The network test equipment 100 and the network cards 114 may support one or more well known standards or protocols such as the various Ethernet and Fibre Channel standards, and may support proprietary protocols as well.
The network cards 114 may include one or more field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), programmable logic devices (PLDs), programmable logic arrays (PLAs), processors and other kinds of devices. In addition, the network cards 114 may include software and/or firmware. The term network card encompasses line cards, test cards, analysis cards, network line cards, load modules, interface cards, network interface cards, data interface cards, packet engine cards, service cards, smart cards, switch cards, relay access cards, and the like. The term network card also encompasses modules, units, and assemblies that may include multiple printed circuit boards. Each network card 114 may support a single communications protocol, may support a number of related protocols, or may support a number of unrelated protocols. The network cards 114 may be permanently installed in the network test equipment 100 or may be removable.
Each network card 114 may contain one or more port unit 120 . One port unit or a plurality of port units may connect to the network 190 through respective ports. Each port may be connected to the network through a respective communication medium 185 , which may be a wire, an optical fiber, a wireless link, or other communication medium. The communications media connecting the network to the plurality of port units may be the same or different. Each port unit 120 may generate and transmit test traffic to the network, and each port unit 120 may receive test traffic from the network. Packets transmitted by one of the port units 120 may commonly be received by one or more other port units.
The backplane 112 may serve as a bus or communications medium for the network cards 114 . The backplane 112 may also provide power to the network cards 114 .
The network test equipment may communicate with a test administrator 105 . The test administrator 105 may be a computing device contained within, or external to, the network test equipment 100 . The network test equipment may include an operator interface (not shown) for receiving test instructions from and displaying test results to an operator.
The network 190 may be a Local Area Network (LAN), a Wide Area Network (WAN), a Storage Area Network (SAN), wired, wireless, or a combination of these, and may include or be the Internet. Communications on the network 190 may take various forms, including frames, cells, datagrams, packets or other units of information, all of which are referred to herein as packets. The network test equipment 100 and the network devices 195 may communicate simultaneously with one another, and there may be plural logical communications paths between the network test equipment 100 and a given network device 195 . The network itself may be comprised of numerous nodes providing numerous physical and logical paths for data to travel.
The network device 195 may be any devices capable of communicating over the network 190 . The network devices 195 may include one or more of servers, network capable storage devices including disk drives such as network attached storage (NAS) and storage area network (SAN) devices, routers, relays, hubs, switches, bridges, multiplexers and other devices.
Referring now to FIG. 2 , an exemplary port unit 220 may include a port processor 230 , a traffic generator unit 240 , a traffic receiver unit 260 , and a network interface unit 280 which couples the port unit 220 to a network under test 290 . The port unit 220 may be all or part of a network card such as the network cards 114 .
The port processor 230 may include a processor, a memory coupled to the processor, and various specialized units, circuits, software and interfaces for providing the functionality and features described here. The processes, functionality and features may be embodied in whole or in part in software which operates on the processor and may be in the form of firmware, an application program, an applet (e.g., a Java applet), a browser plug-in, a COM object, a dynamic linked library (DLL), a script, one or more subroutines, or an operating system component or service. The hardware and software and their functions may be distributed such that some functions are performed by the processor and others by other devices.
The port processor 230 may communicate with a test administrator 205 . The test administrator 205 may provide the port processor 230 with instructions and data required for the port unit 220 to participate in testing the network 290 . The instructions and data received from the test administrator 205 may include, for example, definitions of packet streams to be generated by the port unit 220 and definitions of performance statistics to be accumulated and reported by the port unit 220 . The test administrator 205 may be coupled to or include an operator interface 207 . The operator interface 207 may be used to receive commands and requests from an operator (not shown) and to present test data to the operator. The operator may be, for example, a test engineer or system operator who needs access to the test data.
The port processor 230 may provide the traffic generator unit 240 with stream data 232 which may be stored in a stream data memory 242 within the traffic generator unit 240 . The stream data 232 may cause the traffic generator unit 240 to form a plurality of streams that may be interleaved to form outgoing test traffic 246 . The plurality of streams may be portions of a single traffic item or a plurality of traffic items. Each of the streams may include a sequence of packets, which may be divided between a plurality of packet groups. The stream data 232 may include, for example, the type of packet, the frequency of transmission, definitions of fixed and variable-content fields within the packet and other information for each packet stream.
As the traffic generator unit 240 generates the outgoing test traffic 246 , transmit traffic statistics may be stored in a transmit traffic statistics memory 244 . The stored transmit traffic statistics may include, for example, a count of the number of packets generated for each stream.
The network interface unit 280 may convert the outgoing test traffic 246 from the traffic generator unit 240 into the electrical, optical, or wireless signal format required to transmit the test traffic to the network under test 290 via a link 285 , which may be a wire, an optical fiber, a wireless link, or other communications link. Similarly, the network interface unit 280 may receive electrical, optical, or wireless signals from the network over the link 285 and may convert the received signals into incoming test traffic 282 in a format usable to the traffic receiver unit 260 .
The traffic receiver unit 260 may receive the incoming test traffic 282 from the network interface unit 280 . The traffic receiver unit 260 may include a statistic engine 262 and a statistics memory 264 . The statistics engine 262 may identify each received packet as a member of a specific packet group and may extract test data from each packet. The statistics memory 264 may be used to store accumulated traffic statistics for each packet group. The stored statistics for each packet group may include, for example, a total number of received packets, a number of packets received out-of-sequence, a number of received packets with errors, a maximum, average, and minimum latency or propagation delay, and other statistics for each packet group. After each new packet is received, the statistics engine 262 may update the test statistics stored in the statistics memory 264 for the associated packet group.
The traffic receiver unit 260 may also capture and store specific packets in accordance with capture criteria provided by the port processor 230 . The traffic receiver unit 260 may provide test statistics and/or captured packets 266 to the port processor 230 , for additional analysis during, or subsequent to, the test session.
The outgoing test traffic 246 and the incoming test traffic 282 may be primarily stateless, which is to say that the outgoing test traffic 246 may be generated without expectation of any response and the incoming test traffic 282 may be received without any expectation of a response or intention of responding. However, some amount of stateful, or interactive, communications may be required or desired between the port unit 220 and the network 290 during a test session. For example, the traffic receiver unit 260 may receive control packets, which are packets containing data necessary to control the test session, that require the port unit to send an acknowledgement or response.
The traffic receiver unit 260 may separate incoming control packets 236 from the incoming test traffic and may route the incoming control packets 236 to the port processor 230 . The port processor 230 may extract the content of each control packet and may generate an appropriate response in the form of one or more outgoing control packets 238 . Outgoing control packets 238 may be provided to the traffic generator unit 240 . The traffic generator unit 240 may insert the outgoing control packets into the outgoing test traffic 246 .
In this patent, a port unit that generates and transmits traffic will be referred to as a source port unit. A port unit that receives traffic will be referred to as a destination port unit. A port unit connected to a network test may function as both a source port unit and a destination port unit.
Referring now to FIG. 3 , a representative packet 300 may include a header 310 and a payload 320 . The header 310 may include a plurality of cascaded headers corresponding to sequential communications protocol layers. For example, the header 310 may include a layer two header, such as a Media Access Control header; a layer three header, such as an Internet Protocol header; and a layer four header, such as a Transmission Control Protocol or User Datagram Protocol header. In some cases, such as packets representing traffic on a virtual local area network, one or more encapsulation headers may be disposed between the layer two header and the layer three header. When a network under test utilises multiprotocol label switching (MPLS), one or more MPLS labels may be disposed between the layer two header and the layer three header. In addition, the header 310 of the packet 300 may be changed during transmission through a network, for example by the addition or removal of MPLS labels, tunneling protocol headers, and/or IP.v6 extension headers. Thus a substantial amount of processing may be required to parse and interpret the various fields within the header 346 .
To allow a packet receiver unit to determine if a received packet is part of a test session, and to enable the packet receiver to extract test data from a received packet without parsing the entire header portion of the packet, the packet 300 may include a signature 322 , a PGID 324 and test data 326 . The test data 326 may include, for example, a sequence number of the packet within a packet group defined by the PGID and/or a timestamp. The signature 322 , the PGID 324 and the test data 326 may commonly be placed in the payload 348 . A traffic receiver may locate the signature 322 within a received packet by performing a floating comparison or pattern match against the known value of the test signature, as described in Published Application US 2007/0115833 A1. Once the signature is located, the traffic receiver unit may locate and extract the PGID 324 and test data 326 based on the known position of these fields in relationship to the signature 322 . As shown in FIG. 3 , the PGID 324 and the test data field 326 may follow immediately after the signature 322 .
In some circumstances, a user may want to collect test data indicating changes made to packets as they are transmitted through a network under test. In particular, a network may modify a quality of service (QoS) or type of service (ToS) field within the headers of at least some packets. To maintain traffic statistics including data indicating changes made to one or more header fields, a traffic receiver may collect and store traffic statistics based on an augmented PGID 328 . The augmented PGID may include, for example, the PGID 324 from the packet payload 320 and all or a portion of a QoS field 312 or other field from the packet header. U.S. Pat. No. 7,643,431 describes methods and apparatus for generating a PGID from two or more fields of a packet.
Referring now to FIG. 4A , a port unit 420 , which may be port unit 220 , may include a traffic receiver 460 and a port processor 430 . The traffic receiver 460 may include a statistics memory 464 for storing statistics on the incoming traffic received at the port unit 420 . The statistics memory 464 may be divided into two separately-accessible memory banks A 1 , B 1 . The port processor 430 may include a memory 434 which may include two memory banks A 2 , B 2 .
As shown in the exemplary timing diagram of FIG. 4B , the memory banks A 1 , B 1 , A 2 , and B 2 may allow traffic statistics to be accumulated continuously while allowing concurrent near real-time analysis of the traffic statistics. From a time t 0 to a time t 1 , traffic statistics 401 may be accumulated in memory bank A 1 within the port unit 420 . At time t 1 , memory bank A 1 may be frozen and memory bank B 1 may be activated to accumulate traffic statistics 402 . Immediately after time t 1 , all or portions of the accumulated traffic statistics 401 may be copied from memory bank A 1 to memory bank A 2 within the port processor 430 . The port processor 430 may then aggregate, analyze, and/or report the accumulated traffic statistics 401 . The time t 0 may be, for example, the start of a test session.
From time t 1 to a time t 2 , traffic statistics 402 may be accumulated in memory bank B 1 within the port unit 420 . At time t 2 , the functions of the memory banks A 1 and B 1 may be reversed. Memory bank B 1 may be frozen and memory bank A 1 may be activated to accumulate traffic statistics 403 . Note that traffic statistics 403 are accumulated along with traffic statistics 401 , which remain in memory bank A 1 . Immediately after time t 2 , all or portions of the accumulated traffic statistics 402 may be copied from memory bank B 1 to memory bank B 2 within the port processor 430 . The port processor 430 may then aggregate, analyze, and/or report the accumulated traffic statistics 401 and 402 which are stored in memory banks A 2 and B 2 respectively.
From time t 2 to a time t 3 , traffic statistics 403 may be accumulated in memory bank A 1 within the port unit 420 . At time t 3 , the functions of the memory banks A 1 and B 1 may again be reversed. Memory bank A 1 may be frozen and memory bank B 1 may be activated to accumulate traffic statistics 404 . Note that traffic statistics 404 are accumulated along with traffic statistics 402 , which remain in memory bank B 1 . Immediately after time t 3 , all or portions of the accumulated traffic statistics 403 may be copied from memory bank A 1 to memory bank A 2 within the port processor 430 . The port processor 430 may then aggregate, analyze, and/or report the accumulated traffic statistics 401 and 403 which are stored in memory bank A 2 and accumulated traffic statistics 402 which are stored in memory bank B 2 respectively.
The time intervals between time t 0 , time t 1 , time t 2 , and time t 3 may be a predetermined capture period. The capture period may be set by a test administrator coupled to the port unit 420 . The test administrator may set the capture period to ensure that the transfer of data between the memory banks and the required aggregating, analyzing, and/or reporting by the port processor can be completed within the capture period.
The time intervals between time t 0 , time t 1 , time t 2 , and time t 3 may be determined by operator requests to view test data. For example, time t 0 may be the start of a test session and times t 1 , t 2 , and t 3 may be respectively associated with first, second, and third operator requests to view specific test data.
As shown in FIG. 4B , either memory bank A 1 or B 1 is alternately available for the traffic receiver 460 to continuously accumulate traffic statistics. Simultaneously, all of the traffic statistics accumulated up to the last time the memory banks A 1 /B 1 were switched is available in memory banks A 2 and B 2 for analysis by the port processor 430 .
Dividing the statistics memory 464 and port processor memory 434 into two banks is not necessary to accumulate and report traffic statistics. For example, if the statistics memory 464 and the port processor memory 434 each have a single bank, the aggregation and display of test statistics may simply be delayed until the test session has been completed. To allow analysis and display of test statistics during a test session, the test session may be briefly suspended while test statistics are transferred from the statistics memory 464 to the port processor memory 434 . Alternatively, the accumulation of test statistics may be continued while test statistics are transferred from the statistics memory 464 to the port processor memory 434 , with the understanding that the transferred statistics may not represent a single specific instant in time.
Description of Processes
Referring now to FIG. 5 , a process 500 for designing a network test session may start at 505 and may finish at 590 . For the purpose of discussion, an assumption is made that the network to be tested uses internet protocol (IP) and IP addresses. However, the process 500 may be applied to designing test session for networks using other protocols and address schemes.
The process 500 may be done, for example, by a test administrator computing device, such as the test administrator 205 , coupled to one or more port units, such as the port unit 220 . The test administrator computing device may be supervised by one or more test engineers or other operators who may provide inputs to automated tools that perform at least part of the process 500 .
The process 500 for designing a network test session may begin by defining a test equipment topology at 510 . Defining the test equipment topology at 510 may include determining how many test ports will be involved in the test session and where each test port will connect to the network. Defining the test equipment topology at 510 may also include defining what each test port will emulate during the test session. Each test port may emulate as little as a single IP address and as much as an entire network encompassing a large plurality of IP addresses. Additionally, defining the test equipment topology at 510 may include defining control packets that will advertise each test port to routers, switches, and other devices within the network using one or more routing protocols such as Border Gateway Protocol, Exterior Gateway Protocol, Open Shortest Path First Protocol, Resource Reservation Protocol and other routing protocols.
At 515 the test traffic to be generated during the test session may be defined. The test traffic may include one or more traffic items. Each traffic item may effectively be a separate test of the network. Each traffic item may be defined as a plurality of streams. Each stream may be described by stream data that defines attributes of the stream such as source port; transmission frequency; fixed and variables fields of the packets in the stream such as, for example, protocol or type of packet, source and destination IP addresses, type of service, and payload content; and other characteristics of each packet in the stream.
An extensive test of a complex network may include thousands of streams comprising a million or more flows. Since it is not possible for a test operator to evaluate or understand a million flows during a test session, tracking factors, or parameters that may be used to categorize and consolidate test statistics, may be defined for each traffic item at 525 - 540 . Tracking factors may include fields within each packet, such as source IP address, destination IP address, type of service, protocol, and other fields. Tracking factors may include information associated with each packet but not included within the packet, such as, for example, source port unit and destination port unit.
As previously discussed, each packet to be generated may include a PGID to identify the packet as a member of a packet group, and traffic statistics may be accumulated for each PGID. To allow the traffic statistics to be sorted, aggregated, and reported based on the defined tracking factors, each PGID value may correspond to a unique combination of values for the tracking factors. In some circumstances, a PGID also may contain information not associated with tracking factors.
The rationale and method for mapping tracking factors to PGIDs can be understood with reference to FIG. 5 and with reference to an example presented in FIG. 6 . In the example of FIG. 6 , an IP.v4 packet 600 includes a type of service (ToS) field 602 , a source IP address field 604 and a destination IP address field 606 which have been defined, at 520 , as tracking factors. Additionally, the example of FIG. 6 assumes that the test session includes four traffic items, and a traffic item identifier 622 is automatically defined to be one of the tracking factors.
The actions from 525 through 540 may be repeated for each tracking factor. At 525 , a first tracking factor may be selected. At 530 , a plurality of values of the selected tracking factor that will actually be used during the test session may be identified. The plurality of values may be identified, for example, by searching the stream data defined at 515 . At 535 , the plurality of actual values may be mapped or compressed to a code associated with the selected tracking factor. The length of the code may be the minimum number of bits necessary to identify each of the plurality of actual values for the tracking factor.
In the example of FIG. 6 , the ToS field 602 of an IPv4 packet is 8 bits in length and thus has 256 possible values. However, during a test session less than all of the 256 possible values for ToS field may be used. The number of values for the ToS field may be determined, at 530 , by analyzing all of the stream data defined at 515 . In the example of FIG. 6 , an assumption is made that only 8 of the 256 possible ToS values are actually used in the test traffic for a specific test item. Thus the ToS values that are actually used may be mapped, at 535 , to a ToS code 624 having only 3 bits. The mapping from the eight actually used 8-bit values of the ToS field 602 to the 3-bit ToS code 624 may be done using a ToS map 612 . The ToS map 612 may be a look-up table or other data structure that uniquely relates each actual ToS field value with a corresponding ToS code value.
Similarly, the header of the exemplary packet 600 includes a 32-bit source IP address field 604 and a 32-bit destination IP address field 606 , each defining about 4.3 billion discrete IP addresses. However, during a test session only a small fraction of the source and destination IP addresses may be used. Further, since at least some of the test ports connected to the DUT may represent networks rather than discrete addresses, a least significant portion, such as a least significant byte or two least significant bytes, of some IP addresses may not be used to differentiate packet groups during a test session. Thus the number of source and destination IP address values that may be tracked during a test session may much smaller than 4.3 billion.
The source and destination IP address values to be tracked during the test session (as identified at 530 ) may be mapped (at 535 ) to respective codes 626 , 628 by respective maps 624 , 626 . For example, 500 source IP address values may be mapped to a 9-bit source IP code 624 by the source IP map 614 . For further example, 250 destination IP address values may be mapped to an 8-bit destination IP code 626 by the destination IP map 616 .
When the values for all of the selected tracking factors have been mapped to respective codes (at 525 - 540 ), the codes may be combined at 545 to form global flow identifiers (IDs). In this context, the term “global” means used everywhere, or used by all port units. Continuing the example of FIG. 6 , the ToS code 624 , the source IP code 626 , and the destination IP code 628 may be combined with a traffic item identifier 622 to form a global flow ID 620 . In this example, the global flow ID 622 includes two bits for the traffic item identifier 622 , three bits for the ToS code 624 , nine bits for the source IP code 626 , and eight bits for destination IP code 628 , for a total of 22 bits. Each value of the global flow ID 620 may correspond to a unique combination of values for the selected tracking factors. More specifically, each value for the global flow ID 620 can be associated with a specific traffic item, a specific ToS, a specific source IP address, and a specific destination IP address.
Continuing the example of FIG. 6 , a 22-bit global flow ID has a capacity to uniquely identify over 4 million packet groups. In an ideal situation, each destination port unit used during the exemplary test session will have the memory capacity (in each of two memory banks, as discussed with respect to FIG. 4A ) to accumulate test statistics on over 4 million different packet groups. In this case, the 22-bit global flow ID may simply be inserted into each packet generated during the test session. However, in a real test environment, it may be impractical or unaffordable to provide this large memory capacity at each port unit. Thus the traffic may be defined such that the number of flows sent to each of the receive port does not exceed the capacity of the ports.
At 550 a destination port may be selected from a plurality of destination ports defined at 510 . At 555 , the global flow IDs of the packets that will be received at the selected port may be identified. At 560 , the global flow IDs identified at 555 may be mapped, or compressed, to a port-specific set of PGIDs by a port-specific PGID map.
For example, a selected destination port may receive 100,000 different flows during a test session, each associated with a unique 22-bit global flow ID. In this case, the 100,000 22-bit global flow IDs may be uniquely mapped to 100,000 17-bit PGIDs for use exclusively in packets sent to the selected destination port. The actions from 550 to 565 may be repeated for each destination port to develop a corresponding PGID map and a corresponding set of PGIDs. Each PGID value may correspond to a single global flow ID value. Since each global flow ID value corresponds to a unique combination of values for the selected tracking factors, each PGID value also may be associated with a specific combination of values for the selected tracking factors.
The PGID map and the set of PGIDs may be different for each destination port. However, a multicast packet can have only a single PGID value. Thus, the global flow ID of a multicast packet flow may be mapped to the same PGID value in the PGID maps of all destination ports that receive the multicast packet flow.
In some circumstances, it may not be possible to generate, at 560 , an acceptable port-specific PGID map for one or more ports. For example, mapping 100,000 global flow IDs to 100,000 17-bit PGIDs is not satisfactory if the destination port only has memory capacity to accumulate traffic statistics for 50,000 packet groups. In such a situation, the process 500 may return to 510 , 515 , or 525 to change the test equipment topology, to redefine the traffic, or to select different tracking factors. The process 500 may repeat iteratively as needed to arrive at an acceptable PGID map for each destination port.
In the example of FIG. 6 , the set of 22-bit global flow IDs 620 may be mapped by a first port PGID map 630 - 1 to a first set of PGID values 632 - 1 . A PGID selected from the first set of PGID values 632 may be incorporated into every packet received at the first destination port. Similarly, the set of 22-bit global flow IDs 620 may be mapped by an n th port PGID map 630 -n to an n th set of PGID values 632 -n. A PGID selected from the n th set of PGID values 632 -n may be incorporated into every packet received at the n th destination port.
When an acceptable PGID may and corresponding set of PGID values have been defined (at 550 - 565 ) for each destination port, the stream data defined, at least in part, at 515 may be completed at 570 by adding appropriate PGID data to each stream definition. At 575 , the stream data may be downloaded to the source ports defined at 510 , and the PGID maps generated at 550 - 565 may be downloaded to corresponding destination ports. After the stream data and maps are downloaded, the process 500 for designing a test session may end at 590 .
Referring now to FIG. 7 , a process 700 for testing a network may be performed by a test administrator, such as the test administrator 205 , coupled to a plurality of port units such as the port unit 200 . Each port unit may include a traffic generator, a traffic receiver, and a port processor. Each traffic receiver may accumulate traffic statistics in a statistics memory which may have two memory banks. If present, the two statistics memory banks in each traffic receiver may be used to accumulate traffic statistics alternately, as described in conjunction with FIG. 4A and FIG. 4B . The process 700 may be cyclic in nature and may repeat continuously for the duration of a test session.
The process 700 may begin after the port units have received stream data and PGID maps, for example from a test session design process such as 575 in the test session design process 500 . At 710 , the test session may be initialized to logically connect the IP addresses represented by the port units to the network under test. Initializing the test session may include the port units advertising their presence to the network under test using one or more routing protocols such as Border Gateway Protocol, Exterior Gateway Protocol, Open Shortest Path First Protocol, Resource Reservation Protocol and other routing protocols. Initializing the test session may also include the port units negotiating communications parameters, for example MPLS labels, with the network under test.
After the port units are logically connected to the network under test at 710 , test traffic may be generated by one or more source ports units at 715 and received by one or more destination port units at 720 . The test traffic may include one or more traffic items. Each traffic item may include a plurality of streams and each stream may include a large plurality of flows. Test traffic may be generated simultaneously by a plurality of source port units at 715 . The test traffic generated by each source port unit may include a plurality of interleaved streams and flows. At 715 , each port unit may also accumulate transmit traffic statistics, including at least a number of packets transmitted for each stream. Test traffic may be received simultaneously by a plurality of destination port units at 720 . Each destination port unit may accumulate received traffic statistics for packet groups identified by a PGID or an augmented PGID extracted from each received packet. The source port units and the destination port units may continuously generate and receive test traffic until a determination is made at 725 that all required test traffic has been transmitted.
At 730 , an operator may request and view near real-time test data. In this patent, the term “near real-time” means current except for a processing delay that is small with respect to the overall duration of a test session. Near real-time test data may be, for example, delayed by a period of a few seconds to a few minutes. Near real-time test data may be reported or viewed at 730 concurrently with and/or after traffic statistics are accumulated at 715 and 720 . The actions at 730 cannot be performed until at least some traffic statistics have been accumulated at 715 and 720 . The actions at 730 may not be performed until an operator has entered a request to view specific test data. The test data requested and viewed at 730 may include transmit traffic statistics accumulated at 715 and/or received traffic statistics collected at 720 .
Requesting and viewing test data at 730 may be cyclic in nature. The actions at 730 may be repeated each time an operator enters a new request to view test data. The actions at 730 may be periodic and may be repeated at regular time intervals. The time interval at which 730 is repeated may be synchronized with switching statistics memory banks within port units, as described in conjunction with FIG. 4A and FIG. 4B . The actions at 730 may be repeated periodically until a determination is made, at 735 , that no additional test data views are required. The process 700 may finish at 790 when no additional traffic or test data views are required.
FIG. 8 shows a flow chart of a process 830 for viewing received traffic statistics that may be suitable for use as a portion of action 730 in FIG. 7 . The process 830 will be explained in conjunction with an example shown in FIG. 9 . In the following description, reference designators from 830 to 850 refer to FIG. 8 and reference designators from 910 to 940 refer to FIG. 9 .
The process 830 may be performed by an operator interface coupled to a test administrator computing device which is, in turn, coupled to a plurality of port units. The process 830 may be done concurrently with the accumulation of traffic statistics at 815 and 820 . At 820 , accumulated traffic statistics may be stored in a statistics memory having two banks that are used alternately as described in conjunction with FIG. 4A and FIG. 4B .
At 832 , an operator may enter one or more requests to view specific data via an operator interface coupled to the test administrator computing device. For example, the operator may enter the requests using a graphic user interface presented on a display device of the operator interface. Each request may identify one more tracking factors to be used to aggregate and organized the requested data.
In response to the requests entered at 832 , the test administrator may configure the port units to provide received traffic statistics requested at 832 . The test administrator may configure the port units by sending each port unit configuration data. The configuration data may include, for example, a filter mask indicating what received traffic statistics are required, one or more aggregate masks indicating how the received traffic statistics should be summarized, and other information.
At 834 , the test administrator may determine the specific received traffic statistics required to satisfy the requests entered at 832 . The test administrator may generate a unique filter mask for each destination port unit. For example, each filter mask may be a bit string having a single bit corresponding to each port-specific PGID. Each bit of the filter mask may indicate if the received traffic statistics accumulated for corresponding PGID are, or are not, required to satisfy the requests entered at 832 . At 834 , the filter masks may be transmitted to the respective destination port units. The filter masks may include a substantial number of bits (a filter mask for a port unit that accumulates received traffic statistics for 100,000 PGIDs may require 100,000 bits). Long filter masks may be compressed, for example by run-length encoding, for transmission by the test administrator and subsequently decompressed at the respective destination port units. When two or more test data views are requested at 832 , the filter masks generated and transmitted to the destination port units may indicate the received traffic statistics required for all of the requested test data views in combination.
At 836 , the test administrator may generate an aggregate mask corresponding to each requested test data view. The one or more aggregate masks may be common to all destination port units. The aggregate masks may define which global flow ID fields are to be used to aggregate and present the received traffic statistics requested at 832 . The aggregate masks may also be transmitted to the destination port units at 836 .
In this patent, the term “aggregate” has the broad meaning of “to collect or combine into a whole”. The exact mathematical operations involved in aggregating traffic statistics may depend on the nature of the statistics. For example, a number of received packets may be accumulated for each PGID. To aggregate the number of received packets for a plurality of PGIDs, the number of packets received for each of the plurality of PGIDs may simply be summed to provide the aggregate number of packets received. For further example, a maximum latency time may be accumulated for each PGID. To aggregate the maximum latency time for a plurality of PGIDs, the maximum latency for each PGID may be mutually compared and the single largest value may be selected as the aggregate maximum latency.
At 838 , a port processor within each port unit may retrieve received traffic statistics from the statistics memory in accordance with the respective filter mask. As shown in FIG. 9 , each port unit may accumulate received traffic statistics for a set of PGIDs 910 . A filter mask 920 may contain a single bit for each PGID indicating if the received traffic statistics associated with the corresponding PGID are, or are not, required to provide the test data requested at 832 . The PGID set 910 may be filtered by the filter mask 920 to provide a filtered PGID set 925 . Referring back to FIG. 8 , the port processor may retrieve the received traffic statistics associated with each PGID of the filtered PGID set at 838 .
The PGID values in received packets may be assigned in a manner that does not provide for immediate correlation of a PGID with values for tracking factors. At 840 , each PGID of the filtered PGID set 925 may be mapped to a filtered global flow ID set 935 . Each PGID of the filtered PGID set 925 may be mapped to a corresponding global flow ID using a port-specific PGID map 930 , such as the port specific PGID maps 630 - 1 , 630 -n shown in FIG. 6 . Each global flow ID may include fields or codes corresponding to a plurality of tracking factors. Continuing the example of FIG. 6 , each global flow ID of the filtered global flow ID set 935 may include, for example, separate fields corresponding to traffic item, ToS/TC, source IP address, and destination IP address.
At 842 , each port unit may aggregate the received traffic statistics associated with the filtered global flow IDs in accordance with the aggregate mask provide by the test administrator at 836 . The aggregate mask may identify one or more fields of the filtered global flow IDs to be used for sorting and reporting traffic statistics. For example, the 1 st aggregate mask 940 - 1 shown in FIG. 9 identifies (dark shading) the traffic item field. This mask may cause each port units to sort the received traffic statistics associated with the filtered global flow IDs in accordance with the value of the traffic item field and then aggregate the received traffic statistics for all global flow IDs having the same traffic item value. The 2 nd and 3 rd aggregate masks 940 - 2 and 940 - 3 will be discussed subsequently in conjunction with the discussion of FIG. 11 .
At 844 , the aggregated received traffic statistics may be uploaded from each port unit to the test administrator. Continuing the previous example, one set of received traffic statistics corresponding to each value of the traffic item field may be uploaded from each port unit to the test administrator. At 846 , the test administrator may aggregate the received traffic statistics received from the port units.
At 850 , the test administrator may present the aggregated received traffic statistics from 846 via the operator interface. The aggregated traffic statistics may be presented to an operator via a test data view on a display device within the operator interface. The aggregated received traffic statistics may also be printed, transmitted via a network, stored, and/or reported in some other manner.
At 848 , the test administrator may set or update the capture period used by the port units to determine when to swap statistics memory banks. The capture period may be set to a time just longer than the processing time required at 838 through 846 , such that the test data reported at 850 may be updated as often as possible within the limitations of the test administrator and port devices.
The entire process 830 may be cyclic in nature. The actions from 838 through 850 may be repeated each time the port swap statistics memory banks, or once each capture period. The actions at 832 through 836 may be repeated each time a new test data view is requested.
FIG. 10 shows a flow chart of a process 1030 for viewing transmit traffic statistics that may be suitable for use as a second portion of action 730 in FIG. 7 . The process 1030 may be performed by an operator interface coupled to a test administrator computing device which is, in turn, coupled to a plurality of port units. The process 1030 may be performed concurrently with the accumulation of traffic statistics at 815 and 820 and concurrently with the process 830 for reporting of received traffic statistics as shown in FIG. 8 .
At 1032 , an operator may enter one or more requests to view specific data via an operator interface coupled to the test administrator computing device. For example, the operator may enter the requests using a graphic user interface presented on a display device of the operator interface. Each request may identify one more tracking factors to be used to aggregate and organized the requested data.
In response to the requests entered at 1032 , at 1054 the test administrator may define a plurality of aggregation groups for aggregating transmit traffic statistics accumulated, for example at 715 in FIG. 7 , by transmit port units. An “aggregation group” is a group of traffic statistics that should be aggregated in response to a specific test data view requested at 1032 . The aggregation groups may be defined, for example, by traffic item, IP source and/or destination address, source and/or destination port unit, source and/or destination TCP port, quality or type of service, other factors, and combinations of factors. Test data may commonly be displayed, printed, and otherwise reported in tabular form and the aggregation groups may correspond, for example, to the rows of a table. Displaying and reporting test data in tabular form will be subsequently discussed in further detail in conjunction with FIG. 11 .
At 1054 , transmit traffic statistics, including transmitted packet counts per stream, may be uploaded from one or more port units to the test administrator computing device. At 1056 , the transmitted packet counts from 1054 may be allocated among the aggregation groups. Allocation of transmitted packet counts between aggregation groups may be done, for example, by the test administrator computing device executing a software application that analyzes the stream forming data for each stream to determine what portion of the packets in each stream belong to each of the aggregation groups defined at 1052 .
For example, assume that a user has requested a test data view consisting of the number of packets transmitted by each source port unit. In this case, the allocation groups would correspond to respective port units and, at 1056 , all of the packets transmitted form a given port unit would be allocated to the corresponding aggregation group.
For a more realistic example, assume that the user request a test data view consisting of test statistics by traffic item. In this case, at 1056 , the stream forming data for every packet stream would be analyzed to determine what portion of the transmitted packets in that stream should be allocated to each aggregation group. For example, at 1056 , the analysis of the stream forming data for a given steam may determine that the stream consists of a sequence of 100 packets that are repeated cyclically. The analysis at 1056 may further determine that the 100 packets in the repeated sequence are uniformly divided between 5 aggregation groups. In this case, if the total transmitted packet count for the stream is 2000 packets, a count of 400 packets would be allocated to each of the five aggregation groups. The analysis and allocation process may be repeated similarly for every packet stream until all of the transmitted packet counts have been allocated among the aggregation groups.
At 1050 , the test administrator may present the aggregated transmit traffic statistics from 1046 via the operator interface. The aggregated transmit traffic statistics may be presented to an operator via a test data view on a display device within or coupled to the operator interface. The aggregated transmit traffic statistics may also be printed, transmitted via a network, stored, and/or reported in some other manner. The aggregated transmit traffic statistics may be presented, printed, transmitted, stored and/or report in some other manner in combination with received traffic statistics from the process 830 or FIG. 8 .
The entire process 1030 may be cyclic in nature. The actions at 1032 through 1050 may be repeated cyclically or each time a new test data view is requested.
FIG. 11 shows exemplary test data views 1101 , 1103 , 1105 which may be displayed to an operator or otherwise reported. The exemplary test data views 1101 , 1103 , 1105 combine aggregated received traffic statistics from the process 830 of FIG. 8 and aggregated transmit traffic statistics from the process 1030 of FIG. 10 . The exemplary test data views are based on the example first started in FIG. 6 . For ease of presentation, only one transmit statistic, number of packets transmitted, and two received traffic statistics, number of packets received and number of packets out-of-sequence, are shown. In a real-world test numerous other received traffic statistics may be accumulated and presented. Received traffic statistics may include quantitative data such as number of packet received, number of packets received out of sequence, and number of packets lost; temporal data such as minimum, maximum, and/or average latency; and other information. The received traffic statistics may include data accumulated at destination port units and data, such as number of packets transmitted, accumulated at source port units.
The first test data view 1101 shows both transmit traffic statistics and received traffic statistics aggregated according to traffic item. The first test data view may be consistent with the 1 st aggregate mask 940 - 1 of FIG. 9 . In keeping with the example of FIG. 6 , traffic item has only four values. The four traffic items and the corresponding aggregated traffic statistics may be displayed, for example, in tabular form as shown at 1101 in FIG. 11 .
The first test data view may be considered a first-level summary of data for a test session. A first-level summary view may present summary test data for all packet groups aggregated in accordance with a selected first tracking factor (in this example—traffic item). Another tracking factor such as, for example, source port number or destination port number may be selected as the first tracking factor and a similar first-level summary test data view may be generated.
An operator, upon reviewing a first-level test data view, may select one specific value for the first tracking factor and then request a second-level test data view aggregated according to a second tracking. In the example of FIG. 11 , an operator may review the first-level test data view 1101 and select Traffic Item 0 (shown with shading). A list 1102 of possible second tracking factors may then be presented, and the operator may select a second tracking factor. In the example of FIG. 11 , the operator is assumed to select Source IP Address (shown shaded in the table 1102 ) as the second tracking factor.
In response to the operator selection of Source IP Address, a second-level test data view 1103 may be generated. The exemplary second-level test data view 1103 may show only test data for Traffic Item 0 , and may show the test data for Traffic Item 0 sorted and aggregated by source IP address. The second-level test data view 1103 may be generated using a filter mask 920 that rejects all test data not associated with Traffic Item 0 and an aggregate mask, such as the aggregate mask 940 - 2 that instructs port unit to aggregate traffic statistics based on the source IP address field of the filtered global flow IDs 925 .
An operator, upon reviewing a second-level test data view, may select one specific value for the second tracking factor and then request a third-level test data view aggregated according to a third tracking factor. In the example of FIG. 11 , an operator may review the second-level test data view 1102 and select source IP address bbb.bbb.bbb.bbb (shown with shading). A list 1104 of possible third tracking factors may then be presented, and the operator may select a third tracking factor. In the example of FIG. 11 , the operator is assumed to select type of service (ToS, shown shaded in the table 1004 ) as the third tracking factor.
In response to the operator selection of ToS, a third-level test data view 1105 may be generated. The exemplary third-level test data view 1005 may show only test data for Traffic Item 0 and source IP address bbb.bbb.bbb.bbb sorted and aggregated by ToS. The third-level test data view 1105 may be generated using a filter mask 920 that rejects all test data not associated with Traffic Item 0 and source IP address bbb.bbb.bbb.bbb and an aggregate mask, such as the aggregate mask 940 - 3 , that instructs port unit to aggregate traffic statistics based on the ToS of the filtered global flow IDs 925 . One or more additional levels of sorting and aggregation may be available, depending on the number of tracking factors used of a given traffic item.
Closing Comments
Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and procedures disclosed or claimed. Although many of the examples presented herein involve specific combinations of method acts or system elements, it should be understood that those acts and those elements may be combined in other ways to accomplish the same objectives. With regard to flowcharts, additional and fewer steps may be taken, and the steps as shown may be combined or further refined to achieve the methods described herein. Acts, elements and features discussed only in connection with one embodiment are not intended to be excluded from a similar role in other embodiments.
As used herein, “plurality” means two or more. As used herein, a “set” of items may include one or more of such items. As used herein, whether in the written description or the claims, the terms “comprising”, “including”, “carrying”, “having”, “containing”, “involving”, and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of”, respectively, are closed or semi-closed transitional phrases with respect to claims. Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements. As used herein, “and/or” means that the listed items are alternatives, but the alternatives also include any combination of the listed items.
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There are disclosed apparatus and methods for testing a network. An apparatus for testing a network may include first and second memory banks configured to alternate between being active and inactive in a complementary manner. A traffic receiver may receive traffic comprising a plurality of packets from the network, accumulate traffic statistics, store the accumulated traffic statistics in the active memory bank of the first and second memory banks, and copy contents of the first memory bank, when inactive, to a third memory bank, and copy contents of the second memory bank, when inactive, to a fourth memory bank. A port processor may aggregate at least selected traffic statistics stored in the third memory bank and the fourth memory bank.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention concerns a gas diffusion layer for fuel cell and a manufacturing method of the same.
[0003] 2. Detailed Description of the Prior Art
[0004] [0004]FIG. 6 is a dismantled cross-section view showing a basic configuration of an element cell of a solid polymer type fuel cell which is one embodiment of the conventional fuel cell. A cell is constructed by bonding an air electrode (cathode) side catalyst layer 2 containing a noble metal (mainly platinum) and a fuel electrode (anode) side catalyst layer 3 respectively to main faces at the both sides of a solid polymer electrolyte film 1 . An air electrode side gas diffusion layer 4 and a fuel electrode side gas diffusion layer 5 are disposed respectively in opposition to the air electrode side catalyst layer 2 and the fuel electrode side catalyst layer 3 . Thereby, an air electrode 6 and a fuel electrode 7 are configured respectively. These gas diffusion layers 4 and 5 has a function to pass an oxidant gas and a fuel gas respectively and, at the same time, to make the current flow to the outside. Then, an element cell 11 is configured by providing a gas passage 8 for reaction gas communication facing the cell, and pinching with a set of separators 10 provided with a cooling water passage 9 for cooling water communication on the opposed main faces and formed of an electrically conductive and gas impermeable material.
[0005] [0005]FIG. 7 is a cross-section view showing a basic composition of a solid polymer type fuel cell stack. A number of element cells 11 are stacked, sandwiched by a collector plate 12 , an insulator plate 13 for of electric insulation and heat insulation, and a tightening plate 14 for maintaining the stacked state by applying a load, and tightened by means of bolts 15 and nuts 17 a tightening load being applied by a plate spring 16 .
[0006] The solid polymer electrolyte film 1 has a proton exchange group in the molecular, and functions as proton electrically conductive electrolyte, as the specific resistance becomes equal to or less than 20Ω cm2, if the water content is saturated. Thus, as the solid polymer electrolyte film 1 functions as proton electrically conductive electrolyte by containing water, in the solid polymer type fuel cell, a method to operate by supplying each element cell 11 with reaction gas saturated with water vapor is adopted.
[0007] When the fuel electrode 7 is supplied with a fuel gas containing hydrogen, and the air electrode 6 with an oxidant gas containing oxygen, the fuel sell electrode reaction for decomposing hydrogen molecular into hydrogen ions and electrons takes place in the fuel electrode 7 and the following electric chemical reaction for generating water from oxygen, hydrogen ions and electrons in the air electrode 6 respectively, the load is supplied with power by electrons moving in an external circuit from the fuel electrode towards the air electrode, resulting in the production of water at the air electrode side.
[0008] Fuel electrode; H 2 →2H + +2e − (fuel electrode reaction)
[0009] Air electrode; 2H + +(½) O 2 +2e − →H 2 O (air electrode reaction)
[0010] Whole; H 2 +(½) O 2 +→H 2 O
[0011] Thus, in addition to water produced by the reaction at the air electrode 6 side, water moving from the fuel electrode 7 side to the air electrode 6 side along with the movement of hydrogen ions also results in.
[0012] Therefore, the gas diffusion layers 4 and 5 are required to assure functions of 1) supplying the catalyst layer evenly with reaction gas to be supplied, 2) conducting the current to the outside, 3) controlling satisfactorily the supply/discharge of reaction produced water and moving water, or other functions.
[0013] Consequently, in the prior art, as gas diffusion layer 4 and 5 , carbon paper, carbon cloth or other electrically conductive porous material, the electrically conductive porous material subjected to the water repellent treatment, or material coated with a mixture formed of carbon powder and water repellent filler on the electrically conductive porous material have been used.
[0014] However, the conventional gas diffusion layer was expensive and, moreover, in case of carbon paper, it has been manufactured by batch as its mechanical strength is not sufficient and fragile, making difficult to form continuously in respect of the electrode manufacturing and resulting in a poor productivity.
SUMMARY OF THE INVENTION
[0015] The first object of the present invention is to solve the problems of the prior art and to supply a cheap gas diffusion layer for fuel cell excellent in water repellency, and also excellent in mechanical strength, allowing a continuous formation.
[0016] The second object of the present invention is to provide a method for manufacturing easily such a gas diffusion layer for fuel cell.
[0017] The Inventors have studied diligently in order to solve the problems of the prior art, and as a result, found that the problems can be resolve by using a gas diffusion layer formed by using a mesh sheet having an heat resistance and an acid resistance such as, for example, stainless mesh, and filling voids of the sheet with a mixture of electrically conductive powder such as carbon powder and water repellent filler such as fluorine resin, and devised the present invention.
[0018] In short, the gas diffusion layer for fuel cell of claim 1 of the present invention is a gas diffusion layer used for at least one of gas diffusion layers of a fuel cell where a fuel electrode side catalyst layer and an air electrode side catalyst layer are disposed at both faces of an electrolyte film, and further a gas diffusion layer is disposed respectively on the outer surface of the fuel electrode side catalyst layer and air electrode side catalyst layer, characterized by that: the gas diffusion layer is formed of a mesh sheet having an heat resistance and an acid resistance, and a mixture of electrically conductive powder and water repellent filler for filling voids of the mesh sheet.
[0019] The gas diffusion layer for fuel cell of claim 2 is the gas diffusion layer for fuel cell of claim 1, wherein a second gas diffusion layer is stacked on a face of the gas diffusion layer in contact with the catalyst layer, the second gas diffusion layer being formed of the mixture of electrically conductive powder and water repellent filler, and presenting a void rate smaller than that of the gas diffusion layer.
[0020] The gas diffusion layer for fuel cell of claim 3 is the gas diffusion layer for fuel cell of claim 2, wherein the content of water repellent filler contained in the second gas diffusion layer is higher than the content of water repellent filler contained in the gas diffusion layer.
[0021] The gas diffusion layer for fuel cell of claim 4 is the diffusion layer for fuel cell of any of claims 1 to 3, wherein the fiber forming the mesh sheet is coated beforehand with water repellent material.
[0022] The gas diffusion layer for fuel cell of claim 5 is the gas diffusion layer for fuel cell of any of claims 2 to 4, wherein the thickness of the second gas diffusion layer is smaller than that of the gas diffusion layer.
[0023] The gas diffusion layer for fuel cell of claim 6 is the gas diffusion layer for fuel cell of any of claims 2 to 5, wherein the electrically conductive powder used for the gas diffusion layer and the second gas diffusion layer is carbon powder, and the specific surface area of the carbon powder used for the gas diffusion layer is smaller than the specific surface area of the carbon powder used for the second gas diffusion layer.
[0024] The claim 7 of the present invention is a manufacturing method of the gas diffusion layer for fuel cell of claim 1 or 2, comprising the steps of, making a gas diffusion layer (precursor) using the mixture of electrically conductive powder, water repellent filler and hole making agent powder, or stacking further the second gas diffusion layer (precursor) and, thereafter, decomposing and scattering the hole making agent by heat treatment to form a gas diffusion layer having there fine holes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1( a ) is an illustrative drawing showing schematically the cross-section view of one embodiment of gas diffusion layer for fuel cell of the present invention, while ( b ) is a plan illustrative drawing of a mesh and porous sheet having a heat resistance.
[0026] [0026]FIG. 2( a ) is an illustrative drawing showing schematically the cross-section view of another embodiment of gas diffusion layer for fuel cell of the present invention, while ( b ) is a plan illustrative drawing of a mesh sheet having a heat resistance and an acid resistance.
[0027] [0027]FIG. 3 an illustrative drawing showing the manufacturing method of one embodiment of gas diffusion layer for fuel cell of the present invention.
[0028] [0028]FIG. 4 a graphic showing the relation between cell voltage−current density.
[0029] [0029]FIG. 5 a graphic showing the relation between cell voltage−air availability.
[0030] [0030]FIG. 6 a dismantle cross-section view showing a basic configuration of an element cell of solid polymer type fuel cell which is one embodiment of the fuel cell.
[0031] [0031]FIG. 7 a cross-section view showing a basic composition of a solid polymer type fuel cell stack.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] Now embodiments according to the present invention will be described in detail referring to the attached drawings.
[0033] [0033]FIG. 1( a ) is an illustrative drawing showing schematically the cross-section of first embodiment of gas diffusion layer for fuel cell of the present invention, while ( b ) is a plan illustrative drawing of a mesh and porous sheet having a heat resistance.
[0034] In FIGS. 1 ( a ) and ( b ), it should be appreciated that the same components as components shown in FIG. 6 shall be referenced with the same symbols, and their duplicate explanation shall be omitted.
[0035] As shown in FIG. 1( a ), a gas diffusion layer 4 for fuel cell of the present invention is formed by filling voids 21 of a mesh sheet 20 having a heat resistance and an acid resistance as a metal mesh with a mixture 22 of electrically conductive powder such as carbon powder and water repellent filler such as fluorine. A catalyst layer 2 is formed evenly on the upper portion of the gas diffusion layer for fuel cell 4 .
[0036] The material of the mesh sheet 20 having a heat resistance and an acid resistance used for the present invention is not particularly limited, and for example, metals, ceramics, glass, engineering plastics or the others can be used. As metal, to be more specific, fro example, stainless steel base metals (SUS316, SUS304, or others), titan or titan alloys or others can be cited. The hole diameter of the mesh sheet 20 is also not particularly limited, but it is preferable to used those of the order of about 70 to 95% in the porosity. The form of the mesh sheet 20 is also not particularly limited, and any of metal gauze form, plain weave form, textile cloth form, mesh form, punching metal form can be used.
[0037] The mesh sheet 20 having a high mechanical strength can play the role of cell support member. Being formed by filling voids 21 of the mesh sheet 20 with the mixture 22 of electrically conductive powder such as carbon powder and water repellent filler such as fluorine, it is excellent in gas permeability, water repellency or others, can supply the catalyst layer with reaction gas by diffusing sufficiently, and at the same time, can discharged reaction produced water or moving water satisfactorily. Moreover, an excellent mechanical strength thereof allows to form continuously easily, and to provide a cheap gas diffusion layer.
[0038] Though the mesh sheet 20 can be used as it is, it is preferable to coat beforehand the fibers of the mesh sheet 20 with water repellent material such as fluorine resin. Such preliminary coating increases the water repellency in the proximity of the fabric of the mesh sheet 20 , improves and keeps the gas permeability, and at the same time, the water repellent material acts as adhesive between the fabric and the electrically conductive powder such as carbon powder, and prevents conductive powder such as carbon powder from falling from the gas diffusion layer for fuel cell 4 .
[0039] As water repellent filler, to be more specific, for example polytetrafluoroethylene, perfluorocarbon sulfonic acid, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polychlorotrifluoroethylene, polyfluorovynilidene, polyfluorovinyl, and tetrafluoroethylene-ethylene copolymer or others can be cited.
[0040] To be more specific, as electrically conductive powder, for example, carbon powder, graphite powder, carbon fiber powder, metal powder, metal fiber powder, metal plating ceramics can be cited.
[0041] [0041]FIG. 2( a ) is an illustrative drawing showing schematically the cross-section of another embodiment of gas diffusion layer for fuel cell of the present invention, while ( b ) is a plan illustrative drawing of a mesh sheet having a heat resistance and an acid resistance.
[0042] In FIG. 2( a ) and ( b ), it should be appreciated that the same components as components shown in FIG. 6 shall be referenced with the same symbols, and their duplicate explanation shall be omitted.
[0043] As shown in FIG. 2( a ), in the gas diffusion layer 4 A for fuel cell of the present invention, the gas diffusion layer 4 is formed by filling voids 21 of a mesh sheet 20 having an heat resistance and an acid resistance as a metal mesh with a mixture 22 of electrically conductive powder such as carbon powder and water repellent filler such as fluorine. A second gas diffusion layer 23 is formed of a mixture of electrically conductive powder and water repellent filler in the same composition ratio as the mixture 22 or in a different composition ratio thereof on a face of the gas diffusion layer 4 to be come into contact with the catalyst layer 2 of the gas diffusion layer 4 . The second gas diffusion layer 23 presenting a void rate smaller than that of the gas diffusion layer 4 is stacked The catalyst layer 2 is formed uniformly on the upper portion of the second gas diffusion layer 23 .
[0044] By adopting the composition, in the gas diffusion layer for fuel cell 4 A of the present invention, the gas diffusion layer 4 having a mesh sheet 20 of high mechanical strength can play the role of cell support member, while the second gas diffusion layer 23 allows to from a more uniform catalyst layer 2 . Besides, since the second gas diffusion layer 23 presenting a void rate- smaller than that of the gas diffusion layer 4 is disposed by stack, the second gas diffusion layer 23 can play a role to control satisfactory the supply/discharge of reaction produced water and moving water.
[0045] Though the content of water repellent material contained in the second gas diffusion layer 23 is not particularly limited, it is preferably higher than the content of water repellent material contained in the gas diffusion layer 4 . Evaporation and scattering of reaction produced water and moving water into the reaction gas can be controlled by increasing the content of water repellent material contained in the gas diffusion layer 4 .
[0046] Though the mesh sheet 20 can be used as it is, as mentioned above, it is preferable to coat beforehand the fabric of the mesh sheet 20 with a water repellent material such as fluorine resin, because such preliminary coating increases the water repellency in the proximity of the fabric of the mesh sheet 20 , improves and keeps the gas permeability, and at the same time, the water repellent material acts as adhesive between the fabric and the electrically conductive powder such as carbon powder, and prevents conductive powder such as carbon powder from falling from the gas diffusion layer for fuel cell 4 .
[0047] The thickness of the second gas diffusion layer 23 is not limited particularly. It is preferable that the thickness of the second gas diffusion layer 23 be inferior to the thickness of the gas diffusion layer 4 . By doing this, the effect of the second gas diffusion layer 23 presenting a lower gas diffusion capacity can be limited, and the gas diffusion of the whole cell can be maintained.
[0048] The electrically conductive powder used for the gas diffusion layer 4 and the second gas diffusion layer 4 A is not specified particularly. However, carbon powder, being cheap and easily available, can be used preferably as electrically conductive powder. Moreover, it is preferable to compose so that the specific surface area of the carbon powder of the gas diffusion layer 4 be smaller than the specific surface area of the carbon powder of the second gas diffusion layer 4 A.
[0049] Whereby, the absorbency of the gas diffusion layer 4 becomes higher than that of the second gas diffusion layer, allowing to move excessive moisture in the second gas diffusion layer 4 A and evaporate in the gas, without stagnation or detention.
[0050] [0050]FIG. 3 is an illustrative drawing showing the manufacturing method of one embodiment of gas diffusion layer for fuel cell of the present invention shown in FIG. 2.
[0051] As shown in FIG. 3, first, a mesh sheet having a heat resistance and a acid resistance as metal mesh is prepared, and then, treated with emulsion of water repellent material such as fluorine resin, and a water repellent treated mesh sheet is made by heat treatment.
[0052] Thereafter, a gas diffusion layer (precursor) is formed by filling voids of the water repellent treated mesh sheet with a mixture of electrically conductive powder, water repellent filler and hole making agent powder. Then, the second gas diffusion layer (precursor) is formed by applying and stacking the mixture of electrically conductive powder and water repellent filler on the gas diffusion layer (precursor).
[0053] Though, in the aforementioned embodiment, the second gas diffusion layer (precursor) is heat treated after stack, the second gas diffusion layer may also be formed after the heat treatment of the gas diffusion layer (precursor) before stacking the second gas diffusion layer (precursor) for obtaining a gas diffusion layer by decomposing, scattering and removing the hole making agent.
[0054] By the manufacturing method, it becomes possible to manufacture easily the gas diffusion layer for fuel cell of the present invention where the void rate of the gas diffusion layer is changed as will only by adding steps of decomposing, scattering and removing the hole making agent.
EMBODIMENT OR EXAMPLE
[0055] Now the present invention shall be described more in detail referring to examples and comparison examples; however the present invention is not limited by these examples at all.
Example 1
[0056] (1) A metal mesh made of SUS316 (line diameter 0.2 mm) is soaked in a FEP dispersion adjusted to the specific weight of 1.09 and thereafter, dried, and heat treated (360° C., 30 min) to prepare a metal mesh having a FEP layer partially formed on the surface,
[0057] (2) Vulcan XC-72 (specific surface area 250 to 300 m3/g) 7 g, PTFE A (polytetrafluoro ethylene ) powder (PTFE 6CJ) 3 g and hole making agent powder (ammonium acid carbonate) 14 g are mixed using kerosene as dispersion medium, and excessive kerosene is removed. The obtained mixture is formed into a sheet by rollers.
[0058] (3) The sheet mold obtained by the aforementioned (2) and the metal mesh obtained by the aforementioned (1) are stacked, calendered and thereby finished to a thickness substantially equal to the metal mesh thickness, and a sheet shape mold [gas diffusion layer (precursor)] where voids of the metal mesh is filled with the aforementioned mixture is obtained.
[0059] (4) Hole making agent powder (ammonium acid carbonate) is decomposed, scattered and removed through the heat treatment of the sheet shape mold obtained in the aforementioned (3) at 60° C. for 30 min, to prepare a gas diffusion layer (precursor).
[0060] (5) Vulcan XC-72 6 g, 60 weight 5 of PTFE dispersion 6 . 67 g are mixed using terpionel as dispersion medium, to prepare a past having an appropriate viscosity.
[0061] (6) The paste obtained in the aforementioned (5) is applied to the sheet [gas diffusion layer (precursor)] obtained in the aforementioned (4) to a thickness of the order of 0.05 mm and, thereafter, dried at 60° C. for 30 min, and a second gas diffusion layer (precursor) is stacked on the gas diffusion layer (precursor).
[0062] (7) After drying, the gas diffusion layer for fuel cell of the present invention is made by sintering PTFE (water repellent filler) through heat treatment of 360° C. for 30 min.
Example 2
[0063] (1) A metal mesh made of SUS316 (line diameter 0.2 mm) is soaked in a FEP dispersion adjusted to the specific weight of 1.09 and thereafter, dried, and heat treated (360° C., 30 min) to prepare a metal mesh having a FEP layer partially formed on the surface.
[0064] (2) Ketjenblack (specific surface area: 800 m3/g) 7 g, PTFE powder (PTFE 6CJ) 3 g and hole making agent powder (ammonium acid carbonate) 14 g are mixed using kerosene as dispersion medium, and excessive kerosene is removed. The obtained mixture is formed into a sheet by rollers.
[0065] (3) The sheet mold obtained by the aforementioned (2) and the metal mesh obtained by the aforementioned (1) are stacked, calendered and thereby finished to a thickness substantially equal to the metal mesh thickness, and a sheet shape mold [gas diffusion layer (precursor)] where voids of the metal mesh is filled with the aforementioned mixture is obtained.
[0066] (4) Hole making agent powder (ammonium acid carbonate) in the sheet shape mold [gas diffusion layer (precursor)] is decomposed, scattered and removed through the heat treatment of the sheet shape mold [gas diffusion layer (precursor)]obtained in the aforementioned (3) at 360° C. for 30 min, after having dried at 60° C. for 30 min, and at the same time, PTFE (water repellent filler) is sintered to prepare a gas diffusion layer.
[0067] (5) Vulcan XC-72 6 g, 60 weight % of PTFE dispersion 6 . 67 g are mixed using terpionel as dispersion medium, to prepare a past having an appropriate viscosity.
[0068] (6) The paste obtained in the aforementioned (5) is applied to the sheet (gas diffusion layer) obtained in the aforementioned (4) to a thickness of the order of 0.02 mm and, thereafter, dried at 60° C. for 30 min, and a second gas diffusion layer (precursor) is stacked.
[0069] (7) After drying, the gas diffusion layer for fuel cell of the present invention is made by sintering PTFE (water repellent filler) in the second gas diffusion layer (precursor) through a heat treatment of 360° C. for 30 min.
Comparison Example 1
[0070] (1) A carbon paper TGP-060 (thickness: 0.2 mm) made by TORAY Co., LTD. is soaked in a PTFE dispersion adjusted to a specific weight of 1.10 and thereafter, dried, and heat treated (360° C., 30 min).
[0071] (2) Vulcan XC-72 6 g, 60 weight % of PTFE dispersion 6 . 67 g are mixed using terpionel as dispersion medium, to prepare a past having an appropriate viscosity.
[0072] (3) The paste obtained in the aforementioned (2) is applied to the sheet obtained in the aforementioned (1) to a thickness of the order of 0.02 mm and, thereafter, dried at 60° C. for 30 min, to make a gas diffusion layer.
[0073] (4) After drying, the gas diffusion layer for comparison is formed by sintering PTFE (water repellent filler) through a heat treatment of 360° C. for 30 min.
[0074] [Element Cell for Test]
[0075] An element cell for test of 25 cm2 in electrode area is prepared for evaluation of respective cells, by making the gas diffusion layer prepared in the Examples 1 and 2 and Comparison Example 1 the air electrode side gas diffusion layer, and using the gas diffusion layer prepared in the Comparison Example 1 as the fuel electrode side gas diffusion layer for all.
[0076] [Test Results]
[0077] [0077]FIG. 4 shows the current voltage characteristics of the element cell using the gas diffusion layer of the Examples 1 and 2 and Comparison Example 1. In every element cell prepared by any of Examples, performances substantially equal to the comparison example 1 can be obtained.
[0078] [0078]FIG. 5 shows the air availability dependency of cell voltage in each element cell of the Examples 1 and 2 and Comparison Example 1. In case of Example 2, the voltage tends to lower suddenly at the high air availability side, while the voltage drop amount at the lower air availability side tends to become smaller than that of the conventional example and the Example 1, whereby, performances substantially equal to the comparison example 1 can be obtained.
[0079] The gas diffusion layer for fuel cell of claim 1 of the present invention being formed of a mesh sheet having an heat resistance and an acid resistance, and a mixture of electrically conductive powder and water repellent filler for filling voids of the mesh sheet, it becomes possible to prepare the gas diffusion layer occupying a large part of the material cost of the element cell of fuel cell at a low cost, as a high strength and cheap material can be used as mesh sheet and, moreover, a production excellent in mass productivity is enabled as it becomes possible to take up the gas diffusion layer (sheet) by using a flexible material as mesh sheet, and also the mesh sheet plays the role of cell support as it present a high mechanical strength, or other remarkable effects are deployed.
[0080] Besides, the gas diffusion layer for fuel cell of claim 1 of the present invention is excellent in gas permeability, water repellency or others, and deploys a remarkable effect of being able to supply the catalyst layer with reaction gas by well diffusing, and at the same time, to discharge reaction produced water and moving water satisfactory.
[0081] As the gas diffusion layer for fuel cell of claim 2 is the gas diffusion layer for fuel cell of claim 1, wherein a second gas diffusion layer is stacked on a face of the gas diffusion layer in contact with the catalyst layer, the second gas diffusion layer being formed of the mixture of electrically conductive powder and water repellent filler, and presenting a void rate smaller than that of the gas diffusion layer, it can deploy the same effects as the gas diffusion layer for fuel cell of claim 1 and, furthermore, the second gas diffusion layer allows to form more uniform catalyst layer, and moreover, to control satisfactorily the supply/discharge of reaction produced water and moving water.
[0082] The gas diffusion layer for fuel cell of claim 3 is the gas diffusion layer for fuel cell of claim 2, wherein the content of water repellent filler contained in the second gas diffusion layer is formed higher than the content of water repellent filler contained in the gas diffusion layer and has a remarkable effect of allowing to control the evaporation scattering of reaction water and moving water to the reaction gas.
[0083] The gas diffusion layer for fuel cell of claim 4 is the diffusion layer for fuel cell of any of claims 1 to 3, wherein the fiber forming the mesh sheet is coated beforehand with water repellent material and, thereby, has remarkable effects of enhancing the water repellency in the vicinity of the fiber of mesh sheet, improving and keeping the gas permeability and making the repellent material to act as adherent between the fiber and the electrically conductive powder as carbon powder, thereby preventing the electrically conductive powder as carbon powder from falling from the gas diffusion layer for fuel cell.
[0084] The gas diffusion layer for fuel cell of claim 5 is the gas diffusion layer for fuel cell of any of claims 2 to 4, wherein the thickness of the second gas diffusion layer is smaller than that of the gas diffusion layer, whereby, the effect of the second gas diffusion layer poor in gas diffusion is reduced, and has a remarkable effect of maintaining the gas diffusion of the whole cell.
[0085] The gas diffusion layer for fuel cell of claim 6 is the gas diffusion layer for fuel cell of any of claims 2 to 5, wherein the electrically conductive powder used for the gas diffusion layer and the second gas diffusion layer is carbon powder, which is easily available and cheap, and the specific surface area of the carbon powder used for the gas diffusion layer is made smaller than the specific surface area of the carbon powder used for the second gas diffusion layer, thereby, the absorbency of the gas diffusion layer becomes higher than that of the second gas diffusion layer, allowing to have a remarkable effect of allowing to move excessive moisture in the second gas diffusion layer and evaporate in the gas, without stagnation or detention.
[0086] The manufacturing method of the gas diffusion layer for fuel cell of claim 7 of the present invention has a remarkable effect of allowing to manufacture easily a gas diffusion layer for fuel {{cell}} wherein the void rate of the gas diffusion layer is changed as will, only by adding the step of decomposing, scattering and evaporating the hole making agent.
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The object of the present invention is to provide a cheap gas diffusion layer for fuel cell excellent in gas permeability water repellency, and also excellent in mechanical strength, allowing a continuous formation, and to provide a manufacturing method of the same. A gas diffusion layer used for at least one of gas diffusion layers of a fuel cell where a fuel electrode side catalyst layer and an air electrode side catalyst layer are disposed at both faces of an electrolyte film, and further a gas diffusion layer is disposed respectively on the outer surface of the fuel electrode side catalyst layer and air electrode side catalyst layer, characterized by that the gas diffusion layer is formed of a mesh sheet having an heat resistance and an acid resistance, and a mixture of electrically conductive powder and water repellent filler for filling voids of the mesh sheet.
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BACKGROUND OF THE INVENTION
[0001] Thirty one common fruit extracts were screened for their antioxidant potential by using ABTS' and DPPH' radical scavenging assays and iron chelating capacity. Among them, the extract of Grewia asiatica L. (Phalsa) exhibited not only good in-vitro radical scavenging and iron chelating activity but also found to be good in in-vivo antioxidant and hepatoprotective activity by normalizing liver enzymes levels in animal model. Antioxidant-activity guided isolation of fruits of G. asiatica L., leads to the isolation of new compound, isorhamnetol 5-O-[6″-(3-hydroxy-3methyl glutarate)]β-D-glucodise β-D-glucoside (1) in addition to kaempferol 3-O-β-D-glucoside (2), kaempferol 3-O-α-D-rhamnoside (3), quercetin 3-O-β-D-glucoside (4), quercetin 3-O-β-D-rhamnoside (5), quercetin 3-O-(2-p-courmaroylglucoside (6), myricetin 3-O-β-D-xylosidc (7), 5-hydroxymethylfurfural (8), 3,4-dihydroxybenzoic acid (9), 1,5-dimethyl citrate (10), and trimethyl citrate (11). The structures of the isolated compounds were deduced by using mass spectrometry and 1D- and 2D-NMR techniques. Trolox equivalent antioxidant capacity (TEAC) measurements on compounds 1-11 were also carried out and potent antioxidant activity was observed,
[0002] The fruits of Grewia asiatica L., was identified as potential crop for nutraceutical products as number of bioactive compounds were identified and characterized. Further investigations are needed at molecular level to explore the mechanism of action of active ingredients.
SUMMARY OF THE INVENTION
[0003] An imbalance between the reactive oxygen species (ROS) and endogenous antioxidant defence is suggested to be a major cause of oxidative stress sad ultimately the onset, of various diseases. There are varieties of antioxidant constituents present in human plasma including various classes of naturally occurring compounds, such as ascorbate, various proteins, thiols, bilirubin, urate and α-tocopherol. Diet based on plant-food is recommended due to rich source natural antioxidant compounds. Among the dietary antioxidants, naturally occurring flavonoids in plants have gained a significant recognition in the prevention of diseases and degenerative processes, associated with the oxidative stress. These include cancers, atherosclerosis, rheumatoid arthritis, aging and other clinical conditions associated with generalized leukocytes activation, such as shock, sepsis and trauma.
[0004] In subcontinent, squashes and traditional cold drinks, prepared from fruits of phalsa ( Grewia asiatica L.) are amongst the most popular drinks in the summer seasons. The traditional uses of ripe fruits includes as cooling agent and tonic, for improving digestibility, quench thirst, against burning sensation and inflammation, heart and blood disorders, and fever. It is also good for the treatment of throat problems, and helps in the removal of dead fetus. The fruits of G. asiatica also find uses in folk cultures for the treatment of respiratory, cardiac and blood disorders, as well as for fever and inflammations. Some of the other medicinal properties of the barks of G. asiatica tree include demulcent and febrifuge effect whereas root bark is used for the treatment of rheumatism. The traditional application of the leaves of G. asiatica includes their use against skin eruptions due to its antibiotic properties. The extract of G. asiatica was found to have protective effects against radiation induced oxidative stress.
[0005] Pakistan has a tropical and sub-tropical climate which is suitable tor cultivation of fruits like phalsa ( Grewia asiatica L.). It is, however, felt that phalsa has still not attracted attention of horticulturists to develop or introduce new cultivars that yield better quality of fruits with smaller stone and more flesh. If this is done it can open new vistas in food and beverage industries to step up their production, value addition, health food and nutraceutical production, both for domestic consumption and exports as well.
[0006] On the basis of in-vitro and in-vivo studies, G. asiatica was consequently subjected to characterize the compounds responsible of its antioxidant activities.
DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 depicts comparison of ABTS, DPPH radical scavenging, and Fe 2+ chelating activity of fruits extracts, at conc. 500 μg/mL, values expressed as mean μM±SEM, where n=3.
[0008] FIG. 2 depicts results of TAS (mmol/L) in animal oral dietary extract feeding experiment (100 mg/kg/body wt/day). Crude extracts and fractions of ( G. asiatica have higher antioxidant activities in-vivo, in comparison to normal and positive control (Trolox, 100 mg/kg/body wt/day).
[0009] FIG. 3 depicts Key COSY ( ) and HMBC ( ) correlations in compound 1
DETAILED DESCRIPTION OF THE INVENTION
[0010] All chemicals, including standard compounds, were purchased from Sigma-Aldrich (St. Louis, USA). Buffers were prepared in distilled deionized water, obtained from Simplicity Water Purification System (Millipore, USA), HPLC grade ethanol (Merck, Germany) was used as solvent. All assays were performed by using 96-well microplates with Spectramax M2 spectrophotometer (Molecular Devices, CA. USA).
[0011] Fruit samples were purchased from the local vegetable market in Karachi. The botanical identification of the G. asiatica L. was performed by the Department of Botany, University of Karachi (Voucher no. 005, Herbarium No. 01570).
[0012] The edible part of all fruits were obtained by deseeding, peeling and cutting of the samples and then soaking in alcohol (5 L×3) for about two weeks at room temperature. The solvent was filtered and evaporated to obtain crude alcoholic extract for bioactivities.
[0013] The selected G. asiatica L., crude extract was partitioned, re-solubilized in water, and subsequently extracted with various organic solvents. Five major tractions, namely hexanes, dichloromethane, ethyl acetate, butanol and aqueous fraction were prepared.
[0014] DPPH Radical Scavenging Assay
[0015] The solution of DPPH' (1,1-dipheny-2-pierylhydrazyl) was prepared by dissolving DPPH in ethanol (final concentration of 300 μM). [8] To the 96-well plate, 20 μL of sample (extracts/fractions, 500 μg/mL), control (solvent) and standard (1 mM Trolox, 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid) were added and the absorbance was recorded at 515 Nm. 180 μL of prepared DPPH solution was then added and the plates were incubated for 30 min at 37°°C. Decrease in absorbance, before and 30 mm after the addition of radical solution, was measured at 515 nm. The percentage of DPPH radical scavenging activity of ex tract or fractions was calculated by using following formula;
[0000] % Radical Scavenging Activity ( RSA )=100-( OD sample/ OD control)×100 (1)
[0016] ABTS Radical Scavenging Assay
[0017] For ABTS radical scavenging assay, decrease in absorbance of preformed ABTS** solution at 734 nm was recorded to evaluate the inhibition of radicals by active constitutes. Briefly, the reaction mixture or radical solution containing 1 mM ABTS (2-2'-Azinobis-3-ethylbenzthiazoline sulfonate), 35 μM H 2 O 2 , and 6 μM HRP in 0.7% acidified ethanol was prepared. The sample and radical solution were added in a similar manner as discussed earlier, while absorbance at 734 nm was recorded. The decrease in absorbance correlates with the inhibition of pre-formed radicals by antioxidant compounds present in the sample. Results were compared with the Trolox. Percent radical scavenging activity (% USA) was calculated by using Eq. 1.
[0018] Evaluation of Iron (II) Chelating Capacity Assay
[0019] The Fe +2 chelating ability was determined according to the modified method described by Decker and Welch. The concentrations of Fe +2 ions were measured from the formation of ferrous ion-ferrozine complex. In the 96-well plate, 5 μL (500 μg/mL) of selected extracts in pure DMSO (Dimethyl sulfoxide) was mixed with 35 μL of 0.0625 mM FeCl 2 (Ferrous chloride), and 60 μL of 4 mM ferrozine (reagents prepared in deionized distilled water). The mixture was shaken, and left at room temperature for 10 min. The absorbance of resulting mixture (100 μL, total volume) was measured at 562 nm. A lower absorbance of reaction mixture indicated a higher Fe +2 chelating ability. Percent inhibition of absorbance was calculated according to the following formula;
[0000] % Inhibition=100-( OD sample/ OD control)×100 (2)
[0020] Animal Handling and Dosing Conditions
[0021] Male Wistar rats (average weight 120±20 g) were obtained from animal house facility of tbe ICCBS University of Karachi. Rats were boused in polycarbonate cages, containing hardwood chip bedding. A standard pallet diet and water was made available ad-libitum. A 12 hr light/dark cycle was maintained throughout tbe study. After 14 days of acclimatization, the rats were randomized, and divided to 6 animals in each group: control, test, and positive control (Trolox). Oral doses of extracts were given after every alternate day and their physical status and weight changes were monitored daily. Control group has received an equal volume of normal saline for the same period of time. The experiment was terminated after two weeks of feeding. Under mild anesthetic conditions, blood was drawn via heart puncture. Blood was collected in clot activator plastic tubes, and allowed to clot for 30-40 minutes. Serum was separated by centrifugation and then stored at −20° C. till antioxidant status and other biochemical analysis were carried out.
[0022] Total Antioxidant Status (TAS)
[0023] The in-vivo antioxidant activity was evaluated by the method based on the method developed by Miller in 1993, using Randox Total Antioxidant Status assay kit with calibrator and controls (Randox Laboratories Ltd., Admore, UK) on 96-well plate.
[0024] LPT and Lipid Profile
[0025] The diagnostic facilities of PCMD (ICCBS), University of Karachi, were used for the biochemical analysis of serum samples. Lipid profile includes cholesterol, triglycerides, high density lipoproteins (HDL), low density lipoproteins (LDL), and LPT including bilirubin (total and direct), enzymes such as alanine aminotransferase (ALT), alkaline phosphatase (ALP), and gamma glutatmyltransferae (GGT), were measured. These assays were performed by fully automated chemistry analyzer (Hitachi 902, Roche Diagnostics, Japan) with standardized kits, calibrators, and controls. Total lipid was estimated manually by calorimetric method of phosphovanilline on a photometer (Clinicon 4010, Boehringer Meannheim, Germany).
[0026] Isolation of Bioactive Constituents
[0027] General Experimental
[0028] A variety of stationary and mobile phases were used to carry out isolation and purification of active metabolites. Stationary phase includes silica gel (E. Merck, type 60, 70-230, and 230-400 mesh), Sephadex LH-20 (Pharmacia, Uppsala, Sweden), ODS (reverse phase), polyamide, Diaion HP-20 resin, preparative TLC plates (20×20, 0.5 mm thick, PF 254 E. Merck). Recycling preparative HPLC (RP-HPLC) based separation was performed on a JAI LC-908W (Japan Analytical Industry, Japan), equipped with R1 and UV (256 nm) detectors, and ODS H-80, M-80 or L-80 stationary phases (YMC Co., Ltd., Japan). HPLC Grade methanol, acetonitrile and water from Merck were used as mobile phase. TLC Cards (pre-coated silica gel GF-255) were used for the detection purification, viewed at 254 nm under UV lights, and 366 nm for fluorescent spots. For staining TLC ceric sulphate reagent was sprayed, followed by heating.
[0029] Antioxidant Activity Guided and Isolation
[0030] ABTS** radical scavenging activity guided isolation and purification of active metabolites was achieved using following procedures.
[0031] Well-matured G. asiatica fruits ( 20 Kg) were air-dried in shade and defatted by soaking in hexanes. Fruits were then soaked in alcohol (10 L×3) for about two weeks at room temperature. The solvent was filtered and evaporated to obtain crude alcoholic extract (1.2 Kg, 78.01% RSA). Crude extract was dissolved in distilled water and then partitioned with solvent mixture of increasing polarity in order to obtain fractions of hexanes (inactive), dichloromethane (75.4% RSA) ethyl acetate (82.4% RSA), butanol (86.% RSA), and water (87.4% RSA). Ethyl acetate, dichloromethane and aqueous fractions were further subjected to column chromatography for the purification of bioactive secondary metabolites. Dicholoromethane fraction (310 g) was subjected to silica gel column chromatography by using hexanes/DCM as elating solvent. A fraction obtained from 100% DCM (75.54% RSA) was further subjected to silica gel column chromatography with MeOH/DCM as elating solvents, which yielded compound 8. Ethyl acetate traction (220 g) was subjected to polyamide column chromatography by using MeOH/CHCl 3 as eluting solvent. Fraction obtained from 10% MeOH/CHCl 3 (87.93% RSA) when subjected to slica gel column with same eluting agent, yielded 9 sub-tractions. Sub-fraction 3, obtained from 3% MeOH/CH 3 Cl 3 (88.77% RSA) was further subjected to PR HPLC by using L-80 column with 50% MeOH/H 2 O, which yielded compound 9. Sub-fractions 5, obtained from 8% MeOH/CHCl 3 (89.37% RSA) were further subjected to PR HPLC by using ODS-M80column with 3:1 H 2 O/ACN, which yielded compounds 3-7.
[0032] Aqueous extract (200 g) was subjected to HP 20 column chromatography by using MeOH/H 2 O which gives four sub-fractions. Sub-fraction obtained from 1:1 MeOH/H 2 O, (80.50% RSA) was further subjected to LH 20 column chromatography, by using MeOH/H 2 O as eluting solvent which yielded compound 11, and three sub-tractions. Sub-fraction, obtained from 100% MeOH (81.20% RSA) was further subjected to LH20 column chromatography. Sub-fraction obtained by 1:1 MeOH/H 2 O (94.51% RSA) was subjected to repeated ODS polyamide column chromatography by using MeOH/CHCl 3 as eluting agent. Sub-fractions thus obtained from 20%, 40% and 80% MeOH/CHCl 3 , were further subjected to PR HPLC by using ODS-L80 column with 1:1 MeOH/H 2 O as eluting solvent, which yielded compounds 10 and 2 and 1 respectively.
[0033] Spectral Data of New Acylated Flavanoid Glycoside (Isorhamnetol 5-O-[6″-(3-hydroxy-3-methyl glutarate)] β-D-glucoside) (1)
[0034] Yellow amorphous powder UV (CH 3 OH, nm) λ max (log ε): 354 (4.59), 273 (4.70), 257 (4.09), 208.IR (KBr, cm −1 )v max :3390, 1724, 1648, 1643, 1516, 1510, and 1268, EI MS m/z: 622.1 HRFAB MS (+ve): m/z; 623.1620 (Calcd for C 28 H 30 O 16 +H, 623.1612), FAB MS (+ve) m/z: 623 [M+H] + ,FAB MS (−ve) m/z: 621 [M-H] + , for 1 H-NMR (600 MHz CD 3 OD) and 13 C-NMR (125 MHz, CD 3 OD) chemical shifts sec Table 3.
[0000]
TABLE 3
1 H- and 13 C-NMR Chemical shift values of 1
(ppm, CD 3 OD, 400 and 100 MHz respectively)
δ
Position
δ H (J = Hz)
Aglycone
2
—
1
3
1
4
—
1
5
—
1
6
6.17 d (J 8, 6 = 1.8)
1
7
—
1
8
6.38 d (J 6, 8 = 1.8)
9
9
—
1
10
—
1
1′
—
1
2′
7.85 d (J 2′,6′= 2.2)
1
3′
—
1
4′
—
1
5′
6.92 d (J 5′,6′ = 8.4)
1
6′
7.61 dd (J 6′,5′ = 8.4 and J 6′,2′ = 2.2)
1
Sugar
1″
5.21 d (J 1″,2″ = 8.0)
1
2″
3.34-3.50*
7
3″
3.34-3.50*
7
4″
3.34-3.50*
7
5″
3.34-3.50*
7
6″
4.13 bd (J 6″a,6″b = 10.5), 4.09 dd (J 6a″,6b″ = 10.5, J 6″,5″ =
6
3-OH, 3-CH 3 methyl glutaric
1′″
—
1
2′″
2.24 d (J 2″a,2″b = 15.6), 2.30 d (J 2″a,2″b = 15.6)
4
3′″
—
7
4′″
2.38 d (J 4″a,4″b = 14.2), 2.33 d (J 4″a,4″b = 14.2)
4
5′″
—
1
6′″
1.15 s
2
OCH 3
3.94 s
5
Assignments unclear due to overlapping. abbreviations: s; singlet, d; doublet; assignments confirmed by homonuclear decoupling, 1 H— 1 H COSY, NOESY, HMQC, and HMBC.
indicates data missing or illegible when filed
[0035] Trolox Equivalents Antioxidant Capacity (TEAC) Assay of Compounds (1-11)
[0036] Pure compounds and standards (conc. Range 10-1000 μM) were reacted with the fixed concentration of ABTS (0.5 mM) according to the reported method. [12] The decrease in absorbance at 734 nm was recorded 6 min after the addition of pro-formed ABTS radical solution. Standards including Trolox, quercetin, kaempferol and ascorbic acid were used for the comparison of structure-activity relationship with the isolated compounds. The calculation of TEAC values was obtained by plotting the graphs between various concentrations of compounds and percent radical scavenging activity. Slope (m) was then calculated by using the linear regression (y=mx+c) of the plotted curve. Ratio of the value of slope of Trolox with that of isolated compounds was calculated to get TEAC value as follows;
[0000] TEAC Compound =Slope of Trolox/Slope of compound (3)
[0037] Data Analysis
[0038] All the values are expressed as mean±SEM. Statistical analysis was carried out by using one-way ANOVA, followed by the Analysis of Variance. Statistical (Version 5.0) software package was used for statistical analysis.
[0039] Results and Discussion
[0040] In-vitro Radical Scavenging and Iron Chelating Potential of Fruits Extracts
[0041] Thirty one common fruits extracts were screened for their antioxidant activity using the DPPH* and ABTS** radical scavenging assays (Table 1).
[0000]
TABLE 1
ABTS* + and DPPH* radical scavenging activity of fruits extracts
S. No.
Botanical Name
English Name
% ABTS*
% DPPH*
Achrus zapota Linn.
Sapota
16.89 ± 1.61
N.D $
Aegle marmelos Linn. Correa.
Bael
85.47 ± 0.78
56.62 ± 2.86
Ananas comosus L. Merr.
Pineapple
8.28 ± 0.196
29.81 ± 2.65
Averrhoa carambola Linn.
Carambola
67.32 ± 2.10
59.11 ± 213
Carica papaya Linn.
Papaya
7.77 ± 1.32
4.23 ± 0.60
Carissa carandas Linn.
Karanda
20.83 ± 1.21
52.97 ± 3.91
Citrullus lanatus Thunb.
Water Melon
5.91 ± 0.44
6.92 ± 1.26
Citrus aurantifolia Christmann.
Lemon
19.07 ± 3.21
15.83 ± 3.21
Citrus sinensis Linn.
Sweet Orange
7.21 ± 1.56
8.31 ± 0.31
Cocos nucifera Linn.
Coconut
1.47 ± 1.44
19.91 ± 5.32
Cucumis melo Linn.
Sweet Melon
5.56 ± 0.52
N.D $
Eriobotrya japonica Linn.
Loquat
56.62 ± 1.72
48.89 ± 1.45
Fragaria ananassa Duch.
Strawberry
93.82 ± 0.43
59.49 ± 2.86
Grewia asiatica Linn.
Phalsa
78.01 ± 1.51
75.23 ± 0.82
Lichi chinensis Sonner.
Litchi
9.20 ± 2.65
45.01 ± 2.10
Mangifera indica Linn.
Mango
25.92 ± 0.06
24.54 ± 1.21
Malus sylvestris Linn.
Apple
8.62 ± 3.21
N.D $
Morus macroura Miq.
Mulberry
31.30 ± 0.39
26.11 ± 2.10
Musa paradisica Linn.
Banana
19.84 ± 2.11
3.62 ± 1.78
Opuntia vulgaris Linn.
Prickly pear
85.10± 0.035
14.42 ± 0.67
Phoenix dactylifera Linn.
Dates
7.28 ± 0.35
1.48 ± 0.99
Physalis peruviana Linn.
Cape goose berry
40.21 ± 1.21
49.17 ± 0.86
Prunus armeniaca Linn.
Apricot
72.42 ± 0.87
15.58 ± 0.23
Prunus avium Linn.
Cherry
20.93 ± 1.23
31.15 ± 1.45
Prunus domestica Linn.
Plum
7.60 ± 0.62
18.16 ± 0.61
Prunus persica Linn.
Peach
23.50 ± 0.98
14.55 ± 0.60
Psidium guajava Linn.
Guava
38.27 ± 3.12
42.30 ± 1.20
Syzygium jambos L. Aisyon.
Iambul
73.28 ± 1.46
42.70 ± 2.37
Terminalia catappa Linn.
Indian almond
70.91 ± 0.39
69.47 ± 1.13
Vitis vinifera Linn.
Grapes
69.42 ± 0.99
34.20 ± 1.21
Zizyphus jujube Linn.
Indian jujube
19.85 ± 2.33
12.60 ± 2.15
Conc. of extracts, 500 μg/mL, values represent mean μM ± SEM (n = 3),
$ not determined
[0042] Moderate to good RSA were observed with a number of extracts, Aegle marmelos, Eriobotrya japonica, Grewia asiatica, Syzygium jambos, Terminalia catappa and Fragaria ananassa were found to have comparatively good activities and selected for further iron chelating potential evaluation. G. asiatica, S. jambos , and T. catappa were chosen for further in-vivo screening, as their Fe +2 chelating potential was found to be highly significant ( FIG. 1 ).
[0043] In-vivo TAS and Biochemical Analysis of Selected fruit Extracts and Fractions of G. asiatica L.
[0044] The extracts which showed activities in various in-vitro antioxidant assays were evaluated for the in-vivo antioxidant activities by using normal animal model and results were compared with normal and positive control (Trolox treated). Among all selected samples for in-vivo assays, TAS of the crude alcoholic extract of G. asiatica showed the highest activity ( FIG. 2 ). Four major fractions of G. asiatica were also subjected to in-vivo antioxidant activity measurement, and their effects on normal functioning of liver and lipid profile of animals were evaluated.
[0045] The dichloromethane and aqueous fractions of G. asiatica were found to be potent in-vivo antioxidants, compared to positive control ( FIG. 3 ). The results in current study showed normalising effects on enzymes and bilirubin levels in animal groups fed with various fractions of G. asiatica , as compared to positive control (Table 2).
[0000]
TABLE 2
Effects of G. asiatica Sub-Fractions on liver function test (LFT) and lipid profile.
Normal
Positive
Crude
Ethyl
control
control
ext.
Dichloromethane
acetate
Aqueous
Total
213.25 ± 14.32
260 ± 5**
267.5 ± 20.12*
196.5 ± 4.09*
206.5 ± 10.2*
226.5 ± 13.38*
Lipid
(mg/dL)
TAG
34.25 ± 3.34
40 ± 1.54**
43.5 ± 2.25*
38.7 ± 0.23*
39.25 ± 5.89*
40 ± 5.56*
(mg/dL)
Chol
46 ± 2.15
56.75 ± 2.07**
60 ± 5.92*
40 ± 1.54*
41.50 ± 1.35*
49.0 ± 1.87*
(mg/dL)
HDL-c
47 ± 1.77
55 ± 1.97**
58 ± 5.68*
37.0 ± 1.06*
40 ± 1.22*
47.5 ± 1.75*
(mg/dL)
LDL-c
11.25 ± 0.22
14.25 ± 0.96**
14.5 ± 0.43*
12.0 ± 0.94*
11.25 ± 0.54*
10.25 ± 1.14*
(mg/dL)
VLDL
7.5 ± 0.75
8.5 ± 0.25**
8.75 ± 0.41*
7.5 ± 0.25*
8.25 ± 2.28*
8.0 ± 0.94*
(mg/dL)
Total
0.432 ± 0.12
0.51 ± 0.02**
0.45 ± 0.02*
0.46 ± 0.01*
0.45 ± 0.005*
0.43 ± 0.02*
Bilirubin
(mg/dl)
Direct
0.085 ± 0.006
0.085 ± 0.007**
0.057 ± 0.004*
0.035 ± 0.004*
0.075 ± 0.01*
0.052 ± 0.002*
Bilirubin
(mg/dl)
Indirect
0.345 ± 0.01
0.43 ± 0.03**
0.395 ± 0.02*
0.43 ± 0.01*
0.372 ± 0.01*
0.38 ± 0.02
Bilirubin
(mg/dl)
ALT/SGP
37 ± 0.71
45.5 ± 5.49**
43.5 ± 5.55*
41.5 ± 3.27*
48 ± 2.89*
46 ± 6.451*
T (U/L)
ALP (U/L)
117 ± 5.23
212.54 ± 24.51**
159.75 ± 15.25*
180.25 ± 16.27*
192 ± 5.84*
151.5 ± 9.93*
GGT
3 ± 0.61
4.25 ± 0.74
2.75 ± 0.41*
2.25 ± 0.21*
3.25 ± 0.44
2.5 ± 0.25
(U/L)
Results expressed as mean mg/dL or U/L ± SEM, where n = 6,
**P < 0.05: Normal control v/s positive control.
*P < 0.05: Normal control v/s G. asiatica extract and fractions (ANOVA)
[0046] This suggested that various fractions of G. asiatica possess hepatoprotective effect, causing a lowering of the liver enzymes (ALT, ALP, GGT), and bilirubin levels. The study showed that compounds present in the fractions of G. asiatica have a potential to protect liver. The results are in accordance with the earlier reports on other natural products.
[0047] Structure Elucidation of Compounds
[0048] A combination of column chromatography using size exclusion, normal phase and reverse phase adsorbents, were employed to isolate of thirteen compounds from ethyl acetate and aqueous extracts. Compound 1 was isolated as yellow powder. The molecular formula was determined to be C 28 H 30 O 16 from HRFAB-MS (+ve) as it showed [M+H] + m/z 623.1620 (Calcd for C 28 H 30 O 16 +H.623.1612), 13 C- and 1 H-NMR spectra displayed five downfield methine signals at δ c /δ H 100.8/6.17 d (1H,J 6,8 =1.8 Hz), 95.5/6.38 d (1H, J 8,6 =1.8 Hz), 116.9/6.92 d (1H, 5,6 =8.4 Hz), 123,5/7.61 dd (1H, J 6,5 =8.4 Hz, J 6,2 =2.2 Hz), and 114.5/7.85 d (1H, J 2,6 =2.2 Hz), which were assigned to the C-6, C-8, C-6′, C-5′ and C-2′ methane carbons respectively. 13 C- and 1 H-NMR spectrum indicated the presence of a sugar molecule in compound by showing resonances at δ c /δ H 104.3/5.21 d (1H, J 1″,2″ =8.0 Hz, CH-1″), 75.5/3.45 overlapped (1H, CH-2″), 71.1/3.41 overlapped (1H, CH-3″). 75.8/3.40 overlapped (1H, CH-4″), 78.0/3.35 overlapped (1H, CH-5″), and 64.1/4.13 br d (1H, J 6″,5″ =10.5 Hz,) /4.09 dd (1H, J 6a″,6b″ =10.5 Hz, J 6″, 5″ =4.5 Hz, CH 2 -6″). A couple of cross-peaks in the HMBC spectrum between H-1″ (δ H 5.21)/C-5(δ c 161.8), and H-6 ((δ H 6.17)/C-1″ ((δ C 104.3) indicated that β-D-glueopyranoside is substituted at C-5 of the flavonoid skeleton. The HMBC correlation between δ H 3.94 (OMe), and δ C 148.3 (C-3″) indicated the position of the —OMe group at C-3″. Anomeric proton appeared as a doublet at δ H 5.21 (d, J=8.0Hz), which indicated a β-linkage of the sugar moiety. Moreover, the 1 H-NMR spectrum also showed AB geminal protons resonated at δ2.24 (d, J 2″a 2″b =15.6 Hz), and 2.30 (J 2″a,2″b =15.6 Hz), while another AB doublets ascribed to the H 2 -2″, while resonances at δ2.33 (J 4″′a,4″′b =14.2 Hz) and 2.38 (J 4′″a,4′″b =14.2 Hz), which were attributed to the H 2 -4′″.
[0049] Further analysis of the 1D- and 2D-NMR data supported the presence of a hemiterpene unit (3-hydroxy-3-methylglutaric acid) in compound 1, which was found to be substituted with a C-6″ of β-D-glucopyranoside, based on the HMBC correlations. Key HMBC Interactions in compound 1 are shown in FIG. 3 . 13 C-NMR Chemical shifts values of sugar moiety of compound 1 were in accordance with the reported 13 C-NMR values for D-glucose. The stereochemistry at C-3 was deduced by comparasion with the reported spectroscopic data of the same moiety. From the spectral data, the structure of compound 1 was deduced as isorhamnetol 5-O-[6″-(3-hydroxy-3-methyl glutarate)] β-D-glucoside.
[0050] The structures of known, compounds were determined by comparing spectral data with the reported literatures and identified as kaempferol 3-O-β-D-glucoside (2), kaempferol 3-O-β-D-rhamnoside (3), quercetin 3-O-β-D-glucoside (4), quercetin 3-O-β-D-rhamnoside (5), quercetin 3-O-(2-p-coumaroylglucoside) (6), myricetin 3-O-β-D-xyloside (7), 5-hydroxymethylfurfural (8), 3,4-dihydroxybenzoic acid (9), 1,5-dimethyl citrate (10), trimethyl citrate (11). Among them, except compounds 2 and 4 all others were obtained for the first time from this plant.
[0051] Structure-Antioxidant Activity Relationship of Isolated Constituents
[0052] The TEAC assay was used to assess the power of reduction of total amount of ABTS** radicals formed during the reaction by bioactive metaboilite. The ABTS is intensely colored and when it reacts with antioxidant the color disappeared. The TEAC value therefore shows the capacity of a test compound to donate hydrogen and scavenge preformed ABTS** radical cation. In present procedure, the ratio of the slope of concentrations of standard and test compound is taken, therefore TEAC is considered as relative value with no unit. Trolox used as standard antioxidant with TEAC value as 1.
[0053] The 3-OH group with the contiguous double bond in the C-ring consisted to be as radical stabilizer in quercetin (TEAC=1.07±0.23). Glycosylation at C-3 reduces the delocolization, of electron in compounds 3 and 4, but the C-3′ and C-4′-hydroxylation still lead to the higher TEAC values 0.82±0.32 and 0.82±0.23, respectively (Table-4).
[0000]
TABLE 4
The Antioxidant Activities of Isolated
Compounds of Grewia asiatica L.
No
Samples
TEAC a ± SEM
1
Isorhamnetol 5-O-[6″-(3-hydroxy-3-
0.88 ± 0.21
methyl glutarate)] β-D-glucoside (1)
2
Kaempferol 3-O-β-D-glucopyranoside
0.80 ± 0.31
(2)
3
Kaempferol 3-O-β-rhamnpyrnoside (3)
0.91 ± 0.21
4
Quercetin 3-glucoside (4)
0.82 ± 0.32
5
Quercetin 3-rhamnoside (5)
0.82 ± 0.23
6
Quercetin 3-O-β-D-2-p-
0.36 ± 0.19
coumaroylglucoside (7)
7
Myricetin 3-O-β-D-xyloside (6)
0.92 ± 0.35
8
3,4-Dihydroxybenzoic acid (8)
1.05 ± 0.24
9
5-Hydroxymethylfurfural (9)
0.95 ± 0.01
10
1,5-Dimethyl citrate (10)
0.67 ± 0.31
11
Trimethyl citrate (11)
0.58 ± 0.12
12
Quercetin (reference)
1.07 ± 0.23
13
Kaempferol (reference)
0.97 ± 0.27
14
Ascorbic acid (reference)
1.14 ± 0.29
15
Trolox (reference)
1
a TEAC: Trolox equivalent antioxidant capacity. values represent mean ± SEM (n = 3)
[0054] The comparison of quercetin with kaempferol (Table-4) indicated the importance of two adjacent hydroxy* groups in the ring B of quercetin. The C-2/C-3 double bond, and 3-OH groups of keampferol appear to be the major contributor in activity (TEAC 0.97=0.27). Additional third hydroxyl group does not enhances the antioxidant potential in ring B of myricetin when compared, with quercetin (TEAC 0.92±0.35) (Table-4). The results in current study are in accordance with the already established radical stabilization effects of flavonoids. The unsaturation in ring C allows the electron delocalization across the molecule for die stabilization of the aryloxyl radicals.
[0055] Oxygen in furan ring, aldehyde oxygen adjacent to C-1/C-3, and C-4/C-3 double bonds conjugated system makes 5-hydroxymethyl furfural (8) an excellent candidate for radical stabilization effect with highest TEAC value (1.05±0.24), among all. isolated compounds (Table-4). In addition to flavanoid glycosides, 5-hydroxymethyl furfural (8) is the most potent compound obtained from G. asiatica fruit extract. Various bioactivities of this compound have also been reported.
[0056] The hydroxy substituents of 3,4-dihyroxybenzoic acid (9) cause the antioxidant activity. The meta and para hydroxylation on ring A influence the electron withdrawing capacity (Table-4).
[0057] Citric acid derivatives (10 and 11) showed moderate to low antioxidant activity. Carboxylic acid group of citric acid is replaced with methyl groups at C-1 and C-5 in 1.5-dimethyl citrate (10), and at C-1, C-5 and C-6 in trimethyl citrate (11), respectively (TEAC 0.67±0.31, 0.58±0.12) (Table-4).
[0058] The study of natural products for their therapeutic potential has led to the development of many new drugs as well as functional foods. Particularly important are the dietary plants which can serve as functional foods and nutraceuticals to prevent diseases and promote health. The development of new antioxidant supplements, functional ingredients and products should be based on well-defined and systematic screenings against valid therapeutic targets.
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The present invention relates to 5-O-[ 6 ″-( 3 -hydroxy- 3 methyl glutarate)β-D-glucodise as a new antioxidant.
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BACKGROUND OF THE INVENTION
The field of the invention relates to a control system for maximizing power output of internal combustion engines. In particular, the invention relates to controlling the timing of combustion for maximizing engine torque output. Combustion timing may be controlled by controlling ignition timing in one embodiment and fuel timing in another embodiment.
It is known that optimal torque output, within acceptable emission limits, is achieved when ignition timing of an engine is set at "minimum spark for best torque (MBT)." The ignition timing of a particular model of motor vehicle is typically set or calibrated at a predefined spark advance before top dead center (TDC) such that the average of all such vehicles, when new, is near MBT. This approach however has been found to be less than optimal because variations among engines, subsequent maintenance, environmental conditions, and aging often result in an actual MBT which is different from the initial spark advance calibration. It is therefore desirable to have a control system which continuously maintains ignition timing at MBT.
Various approaches have been attempted to achieve MBT during vehicular operation. In one typical approach, pressure transducers are coupled to the combustion cylinders and the crank angle location of peak pressure (LPP) is compared to a reference. Allegedly, the reference is associated with MBT. It is further presumed that LPP always provides a measurement of MBT. Examples of these approaches are found in U.S. Pat. No. 4,063,538 issued to Powell et al, U.S. Pat. No. 4,391,248 issued to Latsch, U.S. Pat. No. 4,481,925 issued to Karau et al, U.S. Pat. No. 4,706,628 issued to Trombley and U.S. Pat. No. 4,760,825 issued to Morita.
A disadvantage of the above approaches is that actual LPP varies with changing operation conditions. That is, the correlation between MBT and LPP is not constant. It is therefore contented that a fixed reference value for LPP does not exist. Another disadvantage is that LPP does not always provide a measurement of MBT in such engines as engines with stratified fuel charges. Accordingly, these types of control systems have been found to be unsatisfactory.
Another approach aimed at achieving MBT is to change spark ignition timing and compare fluctuations in engine speed. Examples of this approach are found in U.S. Pat. No. 4,026,251 issued to Schweitzer et al, and U.S. Pat. No. 4,379,333 issued to Ninomiya et al. In U.S. Pat. No. 4,026,251 ignition timing is perturbed to one side of the reference for a predetermined sample time and engine speed measured. Ignition timing is then perturbed to another side of a reference value for a predetermined sample time and engine speed again measured. Ignition timing is then adjusted in response to the measured difference in engine speed. The inventor herein has recognized numerous disadvantages of this approach. For example, during the sample times, engine speed may vary as a result of changes in operational conditions such as while encountering inclines. Further, engine speed at a particular sample time is also related to engine time at a previous sample time due to inertial effects. Thus, changes, in engine speed are caused by more factors than the perturbation and ignition timing. Accordingly, an accurate measurement of changes in engine torque resulting from changes in ignition timing may not be obtainable. In addition, a predetermined number of samples must be taken at each ignition timing offset as determined by worst case analysis. Stated another way, each ignition timing decision, or correction, occurs at a fixed time interval which is determined by the worst case conditions under which such a decision may be made. These systems have therefore also been found to be unsatisfactory.
SUMMARY OF THE INVENTION
It is an object of the invention herein to provide a control system for optimizing engine torque by adjusting the timing of combustion events.
The problem and disadvantages discussed above are overcome, and object achieved, by providing both an apparatus and method for optimizing power output by updating a timing reference wherein cylinder combustion events are related to the timing reference. In one particular aspect of the invention, the method comprises the steps of: generating the ignition timing reference; generating learning intervals related in timing to the combustion events; offsetting the ignition timing reference during every other one of the learning intervals; calculating pressure differences in the cylinder each learning interval; providing an average value related to said pressure differences; determining whether the average value is converging; and updating the ignition timing reference in response to the determination steps at the end of the learning cycle.
An advantage of the above recited method, is that changes in output power are directly and solely related to the timing reference offset. More specifically, because a pressure difference is calculated once for each timing offset, the time interval is sufficiently short to prevent contribution by changes in vehicular operation. Further, each pressure measurement is independent of previous combustion events. Therefore, changes in output power are solely due to the last timing reference offset. Another advantage is that the timing reference is updated whenever the average pressure differences indicate convergence. Thus, updating occurs in the minimum required time rather than during a time associated with worst case analysis as in prior approaches.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and advantages described herein will be more fully understood by reading the description of the preferred embodiment with reference to the drawings wherein:
FIG. 1 is a block diagram of the system in which the invention is used to advantage;
FIG. 2 is a representation of a portion of the embodiment shown in FIG. 1;
FIG. 3 is a graphical representation of look-up tables associated with the embodiment shown in FIG. 1;
FIGS. 4A and 4B are a flowchart illustrating various process steps performed by a portion of the embodiment shown in FIG. 1;
FIG. 5 is a graphical representation presented to help illustrate operation of the embodiment shown in FIG. 1; and
FIG. 6 is a block diagram of the system in which another embodiment of the invention is used to advantage.
DESCRIPTION OF PREFERRED EMBODIMENTS
An example of an embodiment in which the invention claimed herein is used to advantage is now described with reference to the attached figures. Referring first to FIG. 1, microcomputer 10 is shown controlling ignition module 12 in response to various measurements from engine 14. In this particular example, engine 14 is shown as a conventional 4 cylinder gasoline engine having spark plugs 21, 22, 23, and 24 each receiving electrical energy via respective signals S 1 , S 2 , S 3 , and S 4 from ignition module 12. Each of the spark plugs 21, 22, 23, and 24 is coupled in a conventional manner to respective combustion cylinders 1, 2, 3, and 4 (not shown). Pressure transducers 31, 32, 33, and 34 provide microcomputer 10 with pressure signals P 1 , P 2 , P 3 , and P 4 each related to the actual pressure in respective combustion cylinders 1, 2, 3, and 4. Air intake 40 is shown coupled to intake manifold 42 for inducting air past throttle plate 44 into the combustion cylinders.
Throttle angle sensor 46 is shown coupled to throttle plate 44 for providing throttle angle signal TA. Manifold pressure sensor 48 is shown coupled to intake manifold 42 for providing manifold absolute pressure (MAP) signal related to the manifold pressure in intake manifold 42. Temperature sensor 50 is shown coupled to engine 14 for providing temperature signal T. Crank angle sensor 52 is shown coupled to engine 14 for providing crank angle signal CA related to crankshaft position. Mass air flow sensor 56 is shown coupled to air intake 40 for providing mass air flow signal MAF related to the mass air flow inducted into engine 14. Those skilled in the art will recognize that either MAP sensor 48 or MAF sensor 56 may be used to provide an indication of engine load by known techniques.
It is noted that conventional components necessary for engine operation are not shown such as a fuel delivery system (either carbureted or fuel injected). Those skilled in the art will also recognize that the invention may be used to advantage with other types of engines, such as engines having a number of cylinders other than four.
Referring now to FIG. 2, a block diagram of microcomputer 10 is shown including conventional input/output interfaces 60, central processing unit 62, ROM 64, and RAM 66. Ignition timing signals SA R are permanently stored in ROM 64 for providing base ignition timing at a desired crank angle position before top dead center (TDC) as a function of speed and load. RAM 66 provides trim signals (SA t ) to spark ignition timing signals SA R at the corresponding speed and load points for each cylinder. Engine speed information is calculated from signal CA and load information is calculated from signal MAP by microcomputer 10 in a conventional manner.
Referring to FIG. 3, a three coordinate graph of a SA v speed v load which is applicable to either ROM 64 or RAM 66 is shown. For illustrative purposes, a hypothetical speed v load point (70) is shown within a square (72) defined by four stored SA signals (73, 74, 75, and 76). In response to a particular set of speed and load values (such as represented by point 70) microcomputer 10 calculates a SA signal by interpolation among the four values defined by the surrounding square (such as represented by points 72, 73, 74, and 75).
The operation of microcomputer 10 in controlling ignition timing signal SA for MBT is now described with particular reference to the flowchart shown in FIG. 4 and the associated MBT v SA curve shown in FIG. 5. The operations, or steps, described hereinbelow are performed separately for each cylinder (j) such that a separate, and corrected, ignition timing signal SA is provided to each cylinder.
At the start of each learning cycle, a test or learning interval i for a cylinder j is initiated (see steps 78 and 80). Engine speed and load are then computed in a conventional manner from crank angle signal CA and signal MAP (see step 82). During step 84, ignition timing signal SA R is determined by look-up and interpolation from ROM 64 storage. In a similar manner, ignition timing trim signal SA t is determined by look-up and interpolation from RAM 66. Engine parameters, including throttle angle signal TA, are then monitored to determine whether there are any rapid transients (see step 88). During step 90, engine speed and load are monitored to determine whether they are still within the square of ROM 64 defined by the four SA memory locations which surround the original speed and load points. In the event of either rapid transients or a new square, the present learning cycle is bypassed and ignition timing is trimmed in the same manner that it is trimmed during engine control without a learning interval (see steps 92 and 94).
During step 98, a predetermined ignition timing offset dA i is provided for the i th learning interval of the j th cylinder. Ignition timing offset dA i is only provided for odd learning intervals, otherwise it is set to zero. In response, as shown by step 100, both the ignition trim signal SA t and ignition timing offset dA i are added to ignition timing signal SA R to generate offset ignition timing signal SA i . Thus, the timing of spark energy applied to the j th spark plug is advanced to SA i (see FIG. 5). For the next learning interval, the ignition timing will return to SA i-l .
As shown in step 104, the indicated mean effective pressure (IMEP i ) during the i th learning interval for the j th cylinder is calculated in response to the actual pressure measurement (P i ) for the j th cylinder. The difference in IMEP calculations between the previous and present learning intervals for the j th cylinder (dIMEP i ) is then calculated (see step 106) for the i th learning interval. During step 110, the average of these differences is determined (dIMEP i ) utilizing an average calculation as follows:
dIMEP.sub.i =(-1).sup.i+1 /i*dIMEP.sub.i +(i-1)/i*dIMEP.sub.i-1
In step 112, a statisticl analysis is used to provide a desired confidence level in the above calculation. In this particular example, parametric statistical analysis is used. That is a number of positive and negative signs of dIMEP are counted during the learning cycle. When some preset number N lim of either positive or negative signs is reached, a decision is made that the desired confidence level is achieved and the above calculations have converged.
A determination of dIMEP convergence is then made during step 114. In one particular example, the number of signs in one direction N lim is set to 8, after which a correction of RAM 66 table is initiated. That is, the values in RAM 66 are increased to advance ignition timing for positive signs, and decreased to retard ignition timing for negative signs. The four surrounding memory values of the original engine speed and load point are updated by known extrapolation techniques. The amount of correction is a function of the chosen confidence level. That is, at a lower confidence level a smaller correction to RAM 66 is provided than when the confidence level is set high. In this example, a correction of +1 CA degrees is made to advance RAM table 66, and -2 CA degrees is made to retard RAM 66 table.
During step 116 a decision is made to prevent the learning system from searching for prolonged periods under conditions in which a decision cannot be made. For example, prolonged searching may occur when the MBT curve is excessively flat, or when there is a large variance in IMEP due to engine operating conditions. In this example, the number of learning intervals is compared to a predetermined number N max such as, for example 50 learning intervals for the confidence level corresponding to N lim =8. When an indication of excessive searching is provided, RAM 66 is retarded during step 120 as previously described herein. After RAM 66 is updated, all the calculations provided by the previously described steps are reset and a new learning cycle is started (see step 94).
When there is no indication that either dIMEP i has converged or that the maximum number of learning intervals N max has been reached, the learning interval i is incremented for the j th cylinder. Stated another way, the next time a learning interval is called for the j th cylinder, that learning interval will be incremented by one and the process steps described above repeated for the j th cylinder. Cylinder j is also incremented such that the process steps described above are performed for the next cylinder (see step 118 and 120).
In accordance with the above description, ignition trim signal SA t is updated at different speed and load points in RAM 66 for each of the cylinders. Therefore, ignition timing for each cylinder will be operated near MBT regardless of vehicular aging, maintenance performed, and variations in initial manufacturing tolerances.
Referring now to FIG. 6, an alternate embodiment is shown wherein like numerals refer to like parts shown in FIG. 1. In general terms, the invention is practiced in the embodiment shown in FIG. 6 by controlling the time duration of fuel injection, rather than by controlling ignition timing. More specifically, engine 14' is shown including fuel injectors 221, 222, 223, and 224 coupled to fuel rail 230. Each fuel injector is electronically actuated by respective signals S 1 ', S 2 ', S 3 ', and S 4 ' from fuel module 212. In this particular example, fuel module 212 is responsive to signal SA' from microcomputer 10'. The operation of microcomputer 10' in controlling fuel module 212 and engine 14' is substantially the same as described previously herein with respect to FIGS. 1-4.
This concludes the description of the preferred embodiment. The reading of it by those skilled in the art will bring to mind many alterations and modifications without departing from the spirit and the scope of the invention. The invention may be used to advantage by controlling any engine parameter upon which combustion events are dependant such as ignition timing or the timing of fuel injection. Accordingly, it is intended that the scope of the invention be limited to only the following claims.
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A control system and method for optimizing power in a combustion cylinder of an engine. An ignition timing reference is offset during each learning interval. Differences in indicated mean effective pressure (IMEP) which result from the timing offset are calculated. When a determination is made that the offset timing reference is converging towards an optimal value, the timing reference is updated.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to the field of financial risk reduction and, in particular, to enabling a managing party to assist a funded liability issuer in improving its financial standing by being able to remove long-term, funded liabilities from its balance sheet.
[0003] 2. Description of the Related Art
[0004] Prepaid gift cards and frequent flier and/or other loyalty programs are used extensively these days. One recent study estimates that retailers sold $82 billion worth of gift cards in 2006 alone. Of those, it is predicted that more than $8 billion worth will never be redeemed. Retailers have received this consideration, but cannot book it to revenue on their balance sheets until the cards are actually redeemed.
[0005] In 2004 and 2005 alone, airlines awarded almost 5 trillion frequent flier miles. During that span, travelers redeemed 1.528 trillion miles, resulting in a surplus of almost 3.5 trillion miles for just those two years. In fact, since 1981, the cumulative number of unredeemed frequent flier miles is over 14.2 trillion. An issuer may provide these miles or points in a couple different ways, each of which also attributes a different cash value per mile or point for the company. An airline or similar company may, for example, allow a consumer to earn one mile for every mile flown. Alternatively, the miles may be earned based on the cost of the purchase. For example, one mile or point is earned for every dollar spent on a ticket or a hotel room. Until these miles or points are redeemed by the customer, they remain on the issuer's balance sheet as a funded liability. In addition, while the miles might be earned at one mile per dollar spent and redeemed for less than 1% of that value, the issuer must keep sufficient cash on hand to pay for the fulfillment of the promise a member has for future travel. Even if these miles only cost an airline a fraction of a cent per mile, this still accounts for several billion dollars worth of liabilities on the airlines' balance sheet. In addition, most major hotel chains and credit card companies, among others, offer similar reward programs allowing consumers to earn points each time they stay at the hotel or make a qualifying purchase.
[0006] In both the gift card and frequent flier/loyalty program cases, although the issuer receives cash value for the card or the points at the time of the initial transaction, it cannot book the cash to revenue until the card or points are actually redeemed. Thus, the company has significant liabilities on its balance sheet but does not know when they will be redeemed, if ever. Several states prohibit retailers from putting expiration dates on these cards so, in theory, the liabilities could remain on the balance sheet forever. In fact, it is likely that a percentage of the funded liability may never be redeemed. As a result, an issuer that offers one of these programs not only must report a significant liability on its balance sheet, which negatively affects its borrowing ability, but it must also keep a sizeable amount of cash easily liquefiable in case the liabilities are redeemed, minimizing its investment options.
[0007] There have been attempts to address this problem of long-term, funded liabilities remaining on the issuer's balance sheet. U.S. Published application 2003/0004864 by Kregor, et al, discloses a method by which a liability issuer provides a financial incentive to the party to which the liability was issued to insure the risk of nonpayment or late payment of the liability, thereby minimizing the issuer's risk.
[0008] U.S. Pat. No. 7,076,446 by Kennard addresses the issue of unredeemed funded liabilities in the form of airline frequent flier miles. It teaches a method by which the number of unredeemed miles a participant retains is minimized by giving a participant greater flexibility in redeeming those miles. It sets a threshold number of miles below which the miles cannot be redeemed, but allows the participant to contribute a monetary amount to account for any shortfall if the participant has more than the threshold number of miles but fewer than the total normally needed for redemption.
[0009] U.S. Pat. No. 6,647,375 by Gelman, et al, discloses a method for reducing risk in order to derecognize debt. It teaches a method for taking a liability with a known future value and date at which it is due and calculating its present value for a given interest rate. A third party insurance company buys the liability at a premium, i.e., at a value greater than the present value of the liability. This allows the liability owner to discharge the liability and recognize the difference between the future value of the liability and the premium it paid to the third party as income. When the liability comes due, the third party will discharge the liability. In the interim, however, it may invest the premium so that it will be worth more than the known future value of the debt, thereby obtaining a profit on the transaction.
[0010] While the prior art relates generally to the field of the invention, none of it adequately addresses the needs of an issuer looking to remove the risk associated with a long-term funded liability from its balance sheet unless it also changes the nature of the agreement between the issuer and the party to whom the liability was originally issued.
BRIEF SUMMARY OF THE INVENTION
[0011] A novel method for allowing a second party manager to manage the liability of a first party funded liability issuer. First, the amount of the issuer's funded liability is determined. Then, the parties ascertain the amount of the funded liability or the risk associated with that liability that the issuer is willing to transfer. A discounted amount of consideration to be received from the issuer in exchange for assuming the liability or risk is established. Once the amounts have been determined, the manager accepts the consideration from the issuer and assumes the transferable funded liability or its risk of redemption. In exchange, it confirms assumption with the issuer.
[0012] The method, as it relates to the situation caused by prepaid cards, may provide for the transferable liability being equal to approximately the amount of funded liability expected to remain unredeemed.
[0013] The method allows for flexibility in determining the time span in which funded liabilities are established. Among the allowable time spans, the method may be applied to funded liabilities that are acquired in an already completed time span, from a certain date until inception of the method, or from inception of the method moving forward in time.
[0014] In other aspects, such as those that relate to frequent flier or other loyalty programs, the method may allow for the transferable liability being equal to whatever amount the issuer is willing to transfer, regardless of the amount of funded liability that is expected to remain unredeemed.
[0015] In this aspect, the method involves investing the consideration received from the issuer for a period of time long enough to create a desired profit margin. The manager may either invest the consideration itself, or it may transfer the consideration to a third party financial manager in exchange for interest payments and a financial guarantee. At the end of the period of time, consideration is transferred back to the issuer, along with the payment of a premium, as is the transferred liability or its risk of redemption.
[0016] These and other features and advantages are evident from the following description of the present invention, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a flow chart explaining the general method of the present invention.
[0018] FIGS. 2A-2B are a flow chart depicting an embodiment of the invention as it relates to the funded liability caused, for example, by prepaid gift cards.
[0019] FIGS. 3A-3E are a flow chart depicting an embodiment of the invention as it relates to the funded liability caused, for example, by frequent flier or other loyalty programs.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The invention relates to a new method 10 for improving the financial standing of a company, described broadly in FIG. 1 . The embodiment shown in FIGS. 2A-2B discloses a method 210 as it relates to a company that acquires a funded liability by selling, for example, prepaid cards that may later be redeemed for the company's goods or services.
[0021] Turning to FIG. 1 , a method 10 for managing liability is disclosed. Method 10 includes determining step 20 in which a second party manager determines a first amount of at least one funded liability that a first party issuer possesses. The liability has a known amount, but its redemption date is unknown.
[0022] Method 10 further includes ascertaining step 30 in which the manager ascertains a percentage of the funded liability or the risk of redemption of a percentage of the funded liability that it is willing to assume. In addition, method 10 includes establishing step 40 in which the amount of consideration the manager receives is determined. In accepting step 50 , the manager receives the consideration determined in establishing step 40 . In exchange, the manager also assumes the funded liability or risk of redemption associated with the funded liability that was determined in ascertaining step 30 at assuming step 60 . The amount of the consideration the manager receives in accepting step 50 is less than the value of the funded liability or risk of redemption assumed in assuming step 60 .
[0023] As part of assuming step 60 , the funded liability issuer retains responsibility for payment of any funded liability that is redeemed but which risk was not assumed by the manager. Following assuming step 60 , confirming step 70 provides that, after the issuer has covered redemption of the entire unassumed amount, the manager provides the issuer with some form of financial guarantee to assure that the manager is responsible for payment of any further redemption.
[0024] In one variation, method 10 contains an additional investing step 80 in which the manager may invest the consideration after it has been received from the issuer. Another variation of investing step 80 provides that the manager may transfer the consideration to a third party financial partner which will invest it and, in turn, provide the manager with interest payments for a calculated time over the course of method 10 .
[0025] In another variation, method 10 contains additional returning step 90 that allows the financial partner to return the original amount of consideration to the manager at the end of the calculated period of time. Also in returning step 90 , the manager may return the funded liability or risk of redemption to the issuer along with a second payment of consideration which value is greater than the first payment of consideration.
[0026] Turning now to FIGS. 2A-2B , what is disclosed is a method 210 to allow a funded liability issuer to bring forward a portion of its funded liabilities in order to improve its financial standing. This portion of liability may correspond, for example, to the expected unused balances on the prepaid cards it has issued. Method 210 includes a determining step 220 in which the manager determines a first amount of at least one funded liability that a first party issuer possesses. In one application, because it is already issued and is for a fixed amount, the liability has present and future values that are both known and equal.
[0027] Determining step 220 includes time span choice 221 at which the time span over which the funded liability acquired by the issuer is determined. Electing fixed time option 221 a , the funded liability is established over a predetermined period of time, preferably one fiscal year. In this case, the manager receives the payment and assumes the liability from the issuer at the end of the time period. In clean-up option 221 b , the funded liability results, for example, from all cards that an issuer sold from the inception of its program or its record-keeping until a given date. Under looking forward option 221 c , the funded liability results, for example, from all cards that are sold after a given time. In this instance, every time the issuer sells a card after that date, an agreed-upon percentage of its value is automatically transferred to the manager along with an agreed-upon percentage of the funded liability, as calculated in ascertaining step 230 .
[0028] At this step, the parties generally know that, beyond a certain percentage, a portion of the funded liability will never be redeemed. This amount, known as the “hurdle rate,” may be calculated at hurdle rate calculation 231 using tools commonly used in the art. With this information, a “protected amount” is then calculated at protected amount calculation 232 , preferably by subtracting the hurdle rate from one hundred percent.
[0029] Knowing this information, the manager agrees to assume a percentage of the protected amount, preferably about all of it. In exchange, the funded liability issuer agrees to pay an amount of consideration to the manager and method 210 proceeds to establishing step 240 . At this step, the amount of consideration the manager receives is calculated using payment calculation 241 . How much consideration the funded liability issuer pays in comparison to how much liability the manager assumes may be either a fixed or variable relationship. The manager may elect fixed rate option 241 a and charge the same percentage regardless of the hurdle rate. For example, if the hurdle rate is 70%, 85% or 98%, the manager may charge 20% of the protected amount. Preferably, however, the higher the hurdle rate, the lower the percentage of consideration required in the transaction, leading the manager to elect variable rate option 241 b . In that case, if the hurdle rate for one industry is 98% for example, the issuer might only be required to pay 10% of the remaining 2%. However, if the hurdle rate is 70%, the issuer might have to pay as much as 50% of the remaining 30% that corresponds to the protected amount.
[0030] Once these amounts have been determined, method 210 proceeds to accepting step 250 in which the manager accepts the consideration that was calculated using payment calculation 241 . Method 210 also proceeds to assuming step 260 in which the manager assumes a portion of the protected amount that was calculated using protected amount calculation 232 , preferably all of it. Regardless of the hurdle rate or whether fixed rate option 241 a or variable rate option 241 b is chosen, the monetary value of the liability assumed is greater than the amount of consideration paid. In this embodiment, therefore, the funded liability issuer has to reduce the assets on its balance sheet by the amount of consideration it pays to the manager. However, it receives the benefit of being able to reduce its liabilities by a greater amount equal to the value of the funded liability the manager assumes.
[0031] Once the manager receives the liability and the consideration, method 210 proceeds to confirming step 270 . Although the amount of the funded liability assumed, preferably calculated using protected amount calculation 232 , is the amount of the funded liability that will likely never be redeemed, the manager has to guard against the risk of excess redemptions by making an election under redemption protection choice 271 of confirming step 270 . As one option, the manager may self-insure against the risk of excess redemptions at self-insurance option 271 a . If it has sufficient capital, it may pay out of its own pocket if the funded liability issuer submits a claim. Under insurance option 271 b , the manager may insure the risk of excess redemption with an insurer. In letter of credit option 271 c , the manager may provide the issuer with a letter of credit upon which the funded liability issuer can draw upon submission of a claim. Under promissory note option 271 d , the manager may give the funded liability issuer a promissory note to guard against excess redemption. Finally, if none of these options suit either the manager's or the funded liability issuer's needs, the manager may elect to provide the first party with some other equivalent financial guarantee at other financial guarantee option 271 e.
[0032] After the transfers occur, the parties must determine how often to monitor redemption of funded liabilities at redemption monitoring calculation 272 . They must then determine if redemptions exceed the hurdle rate at redemption threshold calculation 273 . If, during the course of method 210 , redemptions remain below the hurdle rate, method 210 proceeds to first party responsible option 273 a and the manager has no financial obligation to the first party funded liability issuer. If, however, redemptions exceed the hurdle rate, method 210 proceeds to claim submission and repaying step 274 . At this step, the issuer submits a claim for the amount of excess funded liability redeemed during the previous monitoring period. In addition, the manager agrees to compensate the issuer for the excess amount of this redemption over the amount of funded liability assumed. In one variation, evaluation of redemption will occur quarterly at redemption threshold calculation 273 and, at that point, the issuer may submit a claim to the manager for the amount, if any, of the excess at claim submission and repaying step 274 .
[0033] Turning now to FIGS. 3A-3E , the embodiment shown depicts method 310 for improving the financial standing of a company such as an airline, a hotel or a credit card company that issues frequent flier miles or reward points as part of a loyalty program. As in the previous embodiment, method 310 begins with determining step 320 in which the manager determines a first amount of at least one funded liability that a first party issuer possesses.
[0034] In order to ascertain how much liability or risk of redemption associated with the liability to transfer, method 310 includes liability treatment choice 333 in which the manager and issuer agree how to treat the funded liability. Under derecognition option 333 a , the manager actually acquires the liability from the issuer. Further, if electing this option, method 310 requires using liability type choice 334 to choose what form the liability the manager acquires will take. The funded liability may be monetary, valued, for example, in dollars. In contrast, it may be non-monetary, valued, for example in points or miles. Monetary liability option 334 a provides for the manager assuming responsibility for a percentage of the monetary liability, in one variation, calculated using the funded liability issuer's internal conversion rates. In contrast, under non-monetary liability option 334 b , the manager assumes the responsibility for a percentage of the non-monetary liability valued at its monetary equivalent, calculated in one variation using the issuer's internal conversion rates.
[0035] In contrast to derecognition option 333 a , by electing in-substance defeasance option 333 b , the manager does not actually acquire the funded liability. Instead, the liability remains on the issuer's balance sheet. However, it is offset by the manager providing the first party with a financial instrument at confirming step 370 promising to cover the risk of redemption of this portion of the liability. In either case, the following steps are the same and will be described for the variation in which the liability is actually assumed. For in-substance defeasance, replace “funded liability” with “risk of redemption of the funded liability.”
[0036] Remaining with FIGS. 3A-3E , after the manager has decided whether to acquire the funded liability or proceed via in-substance defeasance, the percentage of funded liability to transfer to the manager is calculated at liability amount calculation 335 . Preferably, the issuer will transfer all of it. Since the companies that issue these forms of liability may operate globally, one variation allows for currency choice 336 where the value of the funded liability is examined to see if it is in U.S. dollars. If not, it is converted to U.S. dollars using conversion option 336 a.
[0037] In exchange for the manager agreeing to accept the funded liability, the issuer agrees to pay to the manager a first amount of consideration equal to some percentage of the transferring funded liability, determined at payment calculation 341 . Preferably, the manager will choose fixed rate option 341 a and charge a fixed percentage, regardless of how much funded liability is transferred. This percentage should be at least 50% for the transaction to be financially feasible. Preferably, the funded liability issuer pays a first amount of consideration equal to 75-80% of the amount of funded liability transferred. More preferably, the first party would pay 80%. In addition, the manager may choose variable rate option 341 b and charge an amount that varies with the amount of the funded liability transferred. Preferably the more funded liability transferred, the higher the percentage charged.
[0038] Once the manager knows how much funded liability it is assuming from liability amount calculation 335 and has calculated how much it will charge at payment calculation 341 , it ascertains its desired profit margin at profit margin determination 342 . Knowing the initial value of the first amount of consideration it receives, its desired profit margin and a predetermined rate of interest, the manager calculates the time to achieve the desired profit margin at time calculation 343 using formulas well-known in the art. Preferably, the period of time will be calculated such that the first amount of consideration will grow to an amount equal to about twice the value of the funded liability transferred. More preferably, this period of time will be between 5-10 years. After determining the time span at time calculation 343 , the manager determines if the length of time is acceptable at time acceptability choice 344 . If the calculation results in a period of time outside the preferable 5-10 year span, the manager may still elect to proceed with method 310 . If the manager believes the length of time is unacceptable, method 310 moves to adjustment option 344 a . At this stage, the manager may require the issuer to adjust the amount of funded liability transferred or adjust the amount of consideration. Method 310 then reverts back to time calculation 343 to determine whether the newly calculated time falls within an acceptable range or is acceptable for other reasons.
[0039] Once time calculation choice 344 yields an acceptable result, method 310 proceeds to accepting step 350 . At this step, the manager receives that first amount of consideration that was calculated using payment calculation 341 . Method 310 also proceeds to assuming step 360 in which the manager assumes the funded liability from the issuer that was calculated using liability amount calculation 335 .
[0040] Staying with the embodiment of FIGS. 3A-3E , once the manager receives the first amount of consideration from the funded liability issuer, it has the option to invest the first amount of consideration at investment choice 381 . In one embodiment, the manager may elect self-investment option 381 a and invest the consideration itself. In another embodiment, the manager may elect third-party investment option 381 b and transfer the first amount of consideration, an amount thereof, or its monetary equivalent to a third party who is a financial partner. The financial partner will agree to invest the first amount of consideration at a predetermined rate of interest that will preferably be more favorable than what the issuer can receive by investing the first amount of consideration on its own. However, even if the interest rate is the same or even slightly lower than what the funded liability issuer may receive, method 310 is still beneficial to the issuer because it might be more valuable to reduce the amount of its liabilities than it is to invest the first amount of consideration or because it might have to keep an amount of cash equal to the first amount of consideration on hand to guard against excess redemptions of the liability.
[0041] In one variation of third-party investment option 381 b , the financial partner will add funds of its own to the payment and invest the combined funds to maximize the amount of interest earned. Preferably, the amount of funds added will equal about the difference between the value of the funded liability assumed and the first amount of consideration. In addition, the third party will provide the manager with a first promissory note or other financial document at third-party investment option 381 b and periodic interest payments at interest payment step 382 spread out over the period of time determined at time calculation 343 . The initial value of the first promissory note will preferably be equivalent to the amount of additional funds the third party adds to the investment. Over time, the value of the first promissory note will decrease, ultimately reaching zero at the end of a calculated period of time. However, the total value of the interest payments received will preferably far exceed the initial value of the consideration transferred. At the end of the period of time, the financial partner agrees to return the consideration transferred back to the manager at returning step 390 .
[0042] The issuer will periodically review its situation to determine how much liability was redeemed and how much new liability was issued at redemption monitoring calculation 372 . After the issuer pays the manager at accepting step 350 and transfers a percentage of its funded liability at assuming step 370 , the manager chooses how to protect itself against the risk of excess redemption at redemption protection choice 371 . As with the embodiment of FIGS. 2A-2B , the manager may self-insure against the risk of excess redemptions at self-insurance option 371 a . Under insurance option 371 b , the manager may insure the risk of excess redemption with an insurer. In letter of credit option 371 c , the manager may provide the issuer with a letter of credit upon which the issuer may draw upon submission of a claim. Under promissory note option 371 d , the manager may give the issuer a promissory note to guard against excess redemption. Finally, if none of these options suit either the manager's or the issuer's needs, the manager may elect to provide the issuer with some other equivalent financial guarantee at other financial guarantee option 371 e.
[0043] Under redemption threshold calculation 373 , it is necessary to determine if the number of redemptions requires reimbursement by the manager. However, the issuer retains the risk of redemption of the untransferred miles or points or their cash equivalent under first party responsible option 373 a . However, under confirming step 370 , if redemptions exceed the amount of the funded liability retained by the first party, the second party will cover the cost of redemption of the excess.
[0044] Over the life of method 310 , the parties may elect to renew and modify the agreement using modification choice 345 . The funded liability issuer will have redeemed some of the old miles or points and issued new ones so the parties have to employ new liability calculation choice 346 to determine what the new funded liability to transfer will be. Under all new liability option 346 a , the issuer submits a claim to the manager for the amount of the transferred funded liability that was redeemed and the manager compensates the issuer for that amount. Method 310 then reverts back to liability amount calculation 335 . Any new funded liability established then becomes the basis for the amount the issuer wants to transfer.
[0045] If, instead, marginal liability option 346 b is chosen, at the end of the period of time, the issuer, for example, calculates the number of new miles or points it issued as well as how many miles or points it redeemed since the start of method 310 or the last modification choice 345 , and the difference between the two is the issuer's new funded liability and method 310 reverts back to liability amount calculation 336 .
[0046] If one of the parties terminates method 310 before the time calculated in time calculation 343 , it may be subject to payment of a penalty. Preferably, the penalty is calculated by returning all of the remaining unredeemed funded liability to the issuer but remitting only a fraction of the second amount of consideration.
[0047] If the parties elect not to modify the agreement at modification choice 345 , at the end of the time calculated in time calculation 343 , if third-party investment option 381 b was elected, the financial partner transfers the first amount consideration back to the manager and the value of the promissory note or other financial document has gone to zero at returning step 390 . Also at returning step 390 , the manager pays the issuer for any previously unreimbursed, redeemed funded liability. Still further at returning step 390 , the manager transfers any unredeemed funded liability back to the issuer so that the issuer will become responsible for any future redemption of that funded liability (miles or points, etc.). Having accumulated interest payments dispersed over the period of time, the manager will also repay the first consideration payment to the issuer at a premium, second amount of consideration, at returning step 390 . Preferably, the amount of the premium is such that this total payment is about equal in value to the amount of the funded liability initially assumed. In addition, the payment will preferably be returned in the same currency in which it was received.
EXAMPLE 1
[0048] The following table illustrates the redemption history over a two year span of a group of prepaid gas cards sold in January 2004 by a major retailer.
[0000]
TABLE 1
Number of
Value of
Month,
Unredeemed
Unredeemed
Year
Cards
Cards
Issued:
63,788
$2,290,489.84
January 2004
59,321
$2,013,217.26
February 2004
43,900
$1,253,419.55
March 2004
31,366
$758,450.17
April 2004
24,799
$547,820.84
May 2004
20,547
$423,976.70
June 2004
17,583
$347,618.91
July 2004
15,660
$296,887.09
August 2004
14,552
$266,804.30
September 2004
13,720
$244,348.76
October 2004
13,003
$225,601.81
November 2004
12,301
$209,522.85
December 2004
11,532
$193,623.19
January 2005
11,297
$186,228.56
February 2005
7,909
$159,994.20
March 2005
7,687
$152,692.14
April 2005
7,488
$147,265.03
May 2005
7,338
$143,215.11
June 2005
7,170
$139,019.81
July 2005
3,436
$106,539.34
August 2005
3,401
$104,804.05
September 2005
3,378
$103,481.26
October 2005
3,354
$101,907.78
November 2005
3,314
$98,341.83
December 2005
3,275
$95,002.01
January 2006
2,648
$65,403.27
[0049] In the prepaid gas card sector, a major company issued 63,788 cards totaling $2,290,489.84 in January 2004. In July 2004, 15,660 of those cards, worth $296,887.09, had not been redeemed. In January, 2005, 11,297 cards with a total value of $186,228.56 had not been redeemed. Two years after their issuance, in January 2006, 2,648 cards worth $65,403.27 were not redeemed. This translates to a two-year hurdle rate of approximately 97.14% ($2,225,086.57/$2,290,489.84) and a protected amount of approximately 2.86% ($65,403.27/$2,290,489.84) for these cards. In addition, as of January 2006 the company had an additional 881,002 cards worth a total of $18,033,663.54 that were issued in the months between January 2004 and January 2006 but still not redeemed.
[0050] For the cards issued in January, 2004, if the initially calculated protected amount was 3%, the second party would assume liability for the value of all cards redeemed above $2,221,775.14, or 97% of the initial total worth of the cards. In other words, it would assume 3% of the value of the total liability of these cards, or $68,714.70. In exchange, if the two companies agreed on a consideration percentage of 10%, the first company would pay the second company $6,871.40 to assume this liability.
[0051] As of January 2005, $186,228.56 or 8.13% worth of cards had not been redeemed, still well above the protected amount. In this case, the first party would not be eligible to submit a claim for payment of redeemed cards to the second party.
[0052] However, as of January 2006, only $65,403.27 or 2.86% worth of cards had not been redeemed. Since the protected amount was exceeded by approximately 0.14%, or $3,311.43, the first party would present a claim to the second party for this amount. The second party would then pay this balance to the first party, using a self-insurance, insurance, letter of credit, promissory note or equivalent method.
[0053] The first party then reevaluates redemptions at a later date, preferably quarterly. If further redemptions occur in that time span, the first party may submit another claim, payment for which the second party has still guaranteed.
EXAMPLE 2
[0054] The following table represents an industry-wide analysis of the frequent flier mile programs of the U.S. airline industry from 1981-2005.
[0000]
TABLE 2
Cumulative
Number of
Cumulative
Number of miles
Cumulative
unredeemed
miles awarded
awarded miles
redeemed by
redeemed miles
miles/program liability
by the airlines
to date
members
to date
to date
Year
(in billions)
(in billions)
(in billions)
(in billions)
(in billions)
1981
4.1
4.1
1.9
1.9
2.2
1982
16.8
20.9
12.9
14.8
6.1
1983
38.3
59.2
28.6
43.4
15.8
1984
65.1
124.3
41.9
85.3
39
1985
94.3
218.6
57.3
142.6
76
1986
123.8
342.4
72.8
215.4
127
1987
163
505.4
81.3
296.7
208.7
1988
282.1
787.5
90.8
387.5
400
1989
337.6
1125.1
120.4
507.9
617.2
1990
394.1
1519.2
133.4
641.3
877.9
1991
443.3
1962.5
155.3
796.6
1165.9
1992
498.8
2461.3
178.6
975.2
1486.1
1993
583
3044.3
202.1
1177.3
1867.1
1994
644
3688.3
278.6
1455.9
2232.4
1995
661
4349.3
284.8
1740.7
2608.6
1996
830
5179.3
255.3
1996
3183.3
1997
980
6159.3
271.8
2267.8
3891.5
1998
1120
7279.3
403
2670.8
4608.5
1999
1290
8569.3
358.8
3029.6
5539.7
2000
1440
10009.3
349.5
3379.1
6630.2
2001
1600
11609.3
341.6
3720.7
7888.6
2002
1646
13255.3
402.9
4123.6
9131.7
2003
1730.6
14985.9
512.8
4636.4
10893.9
2004
2240.1
17226.0
633.6
5270.0
12367.3
2005
2714.1
19940.1
894.9
6164.9
14201.2
[0055] As can be seen in the table, the programs expand from year to year so that more new miles are being issued than are being redeemed. For this example, assume a first party airline has 10% of the total sales of frequent flier miles in the industry. In 1995, it therefore would have awarded 66.1 billion frequent flier miles. If each mile is worth one cent, this would be a total funded liability of $661 million. The airline wants the manager to assume the risk of all of the funded liability and is willing to pay 80% of the value, or $528.8 million, to do so. In this case, the manager may choose whether to accept the liability in monetary form or in the form of the miles themselves with the same cash equivalent. Either way, the issuer must reduce its assets by $528.8 million, but it may further reduce its liabilities by the full $661 million.
[0056] Assume the manager elects to align with a third party financial partner to invest the payment. Preferably, the financial partner will contribute $133 million to make the total investment equal the original $665 million and will provide the manager with a promissory note for $133 million. Also, for this example, the third party will be able to invest this amount and achieve a 12% rate of return on its investment. It would take approximately 5.2 years for the initial $532 million to double at a 12% interest rate, which is within the preferred 5-10 year range. The issuer might want to get the cash back sooner rather than later, and the manager might be willing to accept a slightly smaller profit margin, so they could set the arrangement for 5 years. Over these 5 years, the third party will provide the manager with interest payments and the value of the promissory note will steadily decrease to zero.
[0057] At the end of each year, the first party airline will calculate how many new miles it sold and how many miles it redeemed during the year. Assuming the same 10% market share, the first party in this example would have awarded 83 billion new miles, worth $830 million, and redeemed 25.53 billion miles in 2006.
[0058] The parties now have the option of renewing the agreement but must choose how to do so. Again, assume the manager is willing to assume all of the funded liability and the issuer will pay 80% of the value in cash in exchange. The manager may agree to cover redemption of the 25.53 billion miles and pay the issuer $255.3 million, and the issuer can pay 80% of the amount of the new liability, or $664 million and transfer the risk of redemption of all 83 billion miles to the manager.
[0059] Conversely, the difference between the new miles awarded and those redeemed in that year results in a net new funded liability of 57.47 billion miles. At the same one cent conversion rate, this new liability is worth $574.7 million. The manager would not have to pay the issuer for redeeming miles since they are taken into account in the new liability calculation. However, if the issuer wants the manager to assume the risk of this entire amount of new liability at the same 80% conversion rate, it would pay the second party $459.76 million.
[0060] The two parties may make this choice for each period of analysis, preferably yearly, over the course of the life of the agreement.
[0061] In addition, the parties may elect to not renew the agreement. Then, at the end of the first year, the issuer would submit a claim to the manager for the 25.53 billion redeemed miles. The manager would pay the issuer $255.3 million and reduce the amount of funded liability it still possesses by 25.53 billion miles to 40.97 billion miles. At the end of the next year, assuming the same 10% model, 27.18 billion miles will be redeemed. At 1 cent per mile, the manager would pay the issuer $271.8 million and reduce the amount of funded liability it still possesses by 27.18 billion miles to 13.97 billion miles. At the end of the year after that, 40.3 billion miles would have been redeemed, but the manager is only responsible for 13.97 billion of them and would pay the issuer $139.7 million.
[0062] While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific exemplary embodiment and method herein. The invention should therefore not be limited by the above described embodiment and method, but by all embodiments and methods within the scope and spirit of the invention as claimed.
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A method for allowing a second party manager to manage the liability of a first party funded liability issuer by either removing at least a fraction of the funded liability from the issuer's balance sheet or at least offsetting it with a guarantee from the manager to cover the risk of redemption of the liability. The manager will receive a discounted payment of consideration in exchange for taking on the liability. However, the payment will either be calculated such that the liability assumed will likely never be redeemed, minimizing the manager's risk, or else the payment may be invested such that the final value should exceed the potential risk of redemption.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 10/056,893, which was filed on Jan. 24, 2002, and which claims priority under 35 USC § 119(e) to U.S. provisional application Ser. No. 60/263,962 filed Jan. 24, 2001. The entirety of each of these applications is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates in general to the field of toy action figures and games and, in particular, to a surf toy action figure and associated simulated surfing game for play simulation of a live-action surfing experience.
[0004] 2. Description of the Related Art
[0005] Over the last several decades, surfing and associated wave riding activities, e.g., knee-boarding, body-boarding, skim-boarding, surf-kayaking, inflatable riding, and body surfing (all hereinafter collectively referred to as “wave-riding”) have grown in popularity along the world's surf endowed coastal shorelines.
[0006] My U.S. Pat. No. 5,236,280, incorporated herein by reference in its entirety, first disclosed the concept of an artificial simulated wave water ride attraction having an inclined ride surface covered with an injected sheet flow of water upon which riders could perform water skimming maneuvers simulative of actual ocean surfing. Sheet flow water rides are currently in widespread use at many water parks and other locations around the world. Such rides allow the creation of an ideal live-action surfing wave experience even in areas that do not have access to beaches or an ocean.
[0007] However, live-action water rides are generally expensive to construct and operate and, therefore, are not particularly well suited for very small-scale operations such as local family entertainment centers, arcades or similar venues. For these venues video-simulated surfing games have been used to recreate a surfing-like experience within a compact enclosure or game console. For example, U.S. Pat. No. 4,817,950 discloses a video game in which the game player is able to move a figure of a surfer on a video screen by standing on a simulated surfboard and moving the board with his feet; movements of the board from side to side and forward and backward are translated instantaneously to corresponding movements of the surfboard shown on the video screen, allowing the surfing figure to be maneuvered around obstacles, and up and down waves.
[0008] While such video-simulated surfing games are generally well-suited for small scale applications, such as video arcades and the like, they lack the realistic live-action, hydro-dynamic surfing experience of actual ocean surfing.
SUMMARY OF THE INVENTION
[0009] The present invention provides a reduced-scale simulated water ride attraction and associated surf game specifically adapted for use with one or more surf toy action figures. The surf toy action figures are preferably each mountable to a surf board appropriately sized and weighted to provide relatively stable or semi-stable surf-riding action upon a sheet flow of water flowing up an inclined ride surface of the reduced scale attraction. Various surf action figures may be set free upon the ride surface, or they may be constrained or partially constrained by wires, strings, magnets or the like, as desired. Alternatively, or in addition, they may be controlled via a remote control, or radio control transmitter, as desired. Thus, a fun and entertaining game is created that provides realistic live-action surfing within a relatively small or confined area.
[0010] The game also allows persons who may be physically challenged or who are otherwise unable to participate in open ocean surfing or other simulated surf ride attractions to safely participate in and enjoy a realistic live-action surfing experience. Thus, the subject invention pioneers a whole new realm of miniature live-action surf riding, as yet unexplored by current art. In one embodiment a surf-action game is provided comprising an inclined ride surface having a lower base portion and an upper ridge portion. A nozzle is disposed at or near the base portion and is sized and configured to receive a flow of water from a source and to inject the water as a sheet flow upward onto said ride surface. One or more toy surf-action figures are provided and are adapted to ride and/or perform water skimming maneuvers upon the sheet flow of water. Preferably, the inclined surface is substantially containerless and without side walls so as to provide substantially undisturbed flow without significant oblique wave formation, although sidewall-contained embodiments are also possible.
[0011] The nozzle preferably comprises an elongated nozzle extending substantially the width of the ride surface. Optionally, a reservoir may be used to contain a body of water at a desired height and having an opening at the base thereof forming the requisite nozzle. Alternatively, the nozzle may be connected directly to a pressurized water source, such as an ordinary garden hose.
[0012] The toy surf action figures preferably comprise miniature molded human figures in various surfing poses. The surf action figures are preferably mounted on a miniature surf board adapted to skim upon the upward sheet water flow. Optionally, the surf board may comprise a control mechanism adapted to enable a play participant to control the location and/or orientation of the surf action figure in relation to the injected sheet flow. The control mechanism preferably comprises a movable weight controlled by a magnet or radio frequency transmitter and receiver/actuator.
[0013] For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
[0014] All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiments) disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Having thus summarized the general nature of the invention and its essential features and advantages, certain preferred embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description herein having reference to the figures that follow, of which:
[0016] FIG. 1 is a schematic drawing of one embodiment of an inclined ride surface of a simulated surfing game apparatus having features and advantages of the present invention;
[0017] FIG. 2 is a schematic drawing of a surf toy action figure riding on a sheet flow of water flowing upward upon the inclined ride surface of FIG. 1 ;
[0018] FIG. 3 is a perspective view of marionette-style simulated surfing game apparatus having features and advantages of the present invention;
[0019] FIG. 4A is a perspective view of a magnetically operated simulated surfing game apparatus having features and advantages of the present invention;
[0020] FIG. 4B is a detail view of one embodiment of a magnetically operated surf toy action figure and associated actuator for use with the simulated surfing game apparatus of FIG. 4A ;
[0021] FIG. 5 is a perspective view of a radio remote controlled simulated surfing game apparatus having features and advantages of the present invention;
[0022] FIG. 6A is a detail view of one embodiment of a radio remote controlled surf toy action figure for use with the simulated surfing game apparatus of FIG. 5 ;
[0023] FIG. 6B is a detail view of the radio remote controlled surf toy action figure of FIG. 6A making a back-side turn;
[0024] FIG. 6C is a detail view of the radio remote controlled surf toy action figure of FIG. 6A making a front-side turn;
[0025] FIG. 7 is a perspective view of an alternative embodiment of a simulated surfing game apparatus having features and advantages of the present invention; and
[0026] FIG. 8 is a perspective view of a further alternative embodiment of a simulated surfing game apparatus having features and advantages of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] To better understand the features and advantages of the invention described herein a detailed explanation of certain terms is provided below. However, it should be pointed out that these explanations are in addition to the ordinary meaning of such terms, and are not intended to be limiting with respect thereto.
[0028] A body of water is a volume of water wherein the flow of water comprising that body is constantly changing, and with a shape thereof at least of a length, breadth and depth sufficient to permit water skimming maneuvers thereon as limited or expanded by the respective type of flow, i.e., deep water or sheet flow.
[0029] Deep water flow is a flow having sufficient depth such that the pressure disturbance from the rider and his vehicle are not significantly influenced by the presence of the bottom.
[0030] Sheet water flow is a flow having a relatively shallow depth such that the pressure disturbance from the rider and his vehicle are substantially influenced by the presence of the bottom according to the well-known hydrodynamic principle of “ground effect.”
[0031] Water skimming maneuvers are those maneuvers capable of performance on a flowing body of water upon a containerless incline including: riding across the face of the surface of water; riding horizontally or at an angle with the flow of water; riding down a flow of water upon an inclined surface countercurrent to the flow moving up said incline; manipulating the planing body to cut into the surface of water so as to carve an upwardly arcing turn; riding back up along the face of the inclined surface of the body of water and cutting-back so as to return down and across the face of the body of water and the like, e.g., lip bashing, floaters, inverts, aerials, 360's, etc. Water skimming maneuvers can be performed with the human body or upon or with the aid of a riding or planing vehicle such as a surfboard, bodyboard, water ski(s), inflatable, mat, inner tube, kayak, jet-ski, sail boards, etc. In order to perform water skimming maneuvers, the forward force component required to maintain a rider (including any skimming device that he may be riding) in a stable riding position and overcome fluid drag is due to the downslope component of the gravity force created by the constraint of the solid flow forming surface balanced primarily by momentum transfer from the high velocity upward shooting water flow upon said forming surface. A rider's motion upslope (in excess of the kinetic energy added by rider or vehicle) consists of the rider's drag force relative to the upward shooting water flow exceeding the downslope component of gravity. Non-equilibrium riding maneuvers such as turns, cross-slope motion and oscillating between different elevations on the “wave” surface are made possible by the interaction between the respective forces as described above and the use of the rider's kinetic energy.
[0032] The equilibrium zone is that portion of a inclined riding surface upon which a rider is in equilibrium on an upwardly inclined body of water that flows thereover; consequently, the upslope flow of momentum as communicated to the rider and his vehicle through hydrodynamic drag is balanced by the downslope component of gravity associated with the weight of the rider and his vehicle.
[0033] The supra-equidyne area is that portion of a riding surface contiguous with but downstream (upslope) of the equilibrium zone wherein the slope of the incline is sufficiently steep to enable a water skimming rider to overcome the drag force associated with the upwardly sheeting water flow and slide downwardly thereupon.
[0034] The sub-equidyne area is that portion of a riding surface contiguous with but upstream (downslope) of the equilibrium zone wherein the slope of the incline is insufficiently steep to enable a water skimming rider to overcome the drag force associated with the upwardly sheeting water flow and stay in equilibrium thereon. Due to fluid drag, a rider will eventually move in the direction of flow back up the incline.
[0035] The Froude number is a mathematical expression that describes the ratio of the velocity of the flow to the phase speed of the longest possible waves that can exist in a given depth without being destroyed by breaking. The Froude number equals the flow speed divided by the square root of the product of the acceleration of gravity and the depth of the water. The Froude number squared is a ratio between the kinetic energy of the flow and its potential energy, i.e., the Froude number squared equals the flow speed squared divided by the product of the acceleration of gravity and the water depth.
[0036] Subcritical flow can be generally described as a slow/thick water flow. Specifically, subcritical flows have a Froude number that is less than 1, and the kinetic energy of the flow is less than its gravitational potential energy. If a stationary wave is in a sub-critical flow, then, it will be a non-breaking stationary wave. In formula notation, a flow is subcritical when v<square root gd where v=flow velocity in ft/sec, g=acceleration due to gravity ft/sec 2 , d=depth (in feet) of the sheeting body of water.
[0037] Critical flow is evidenced by wave breaking. Critical flow is where the flow's kinetic energy and gravitational potential energy are equal. Critical flow has the characteristic physical feature of the hydraulic jump itself. Because of the unstable nature of wave breaking, critical flow is difficult to maintain in an absolutely stationary state in a moving stream of water given that the speed of the wave must match the velocity of the stream to remain stationary. This is a delicate balancing act. There is a match for these exact conditions at only one point for one particular flow speed and depth. Critical flows have a Froude number equal to one. In formula notation, a flow is critical when v=square root gd where v=flow velocity, g=acceleration due to gravity ft/sec 2 , d=depth of the sheeting body of water.
[0038] Supercritical flow can be generally described as a thin/fast flow. Specifically, supercritical flows have a Froude number greater than 1, and the kinetic energy of the flow is greater than its gravitational potential energy. No stationary waves are involved. The reason for the lack of waves is that neither breaking nor non breaking waves can keep up with the flow speed because the maximum possible speed for any wave is the square root of the product of the acceleration of gravity times the water depth. Consequently, any waves which might form are quickly swept downstream. In formula notation, a flow is supercritical when v>square root gd where v=flow velocity in ft/sec, g=acceleration due to gravity ft/sec 2 , d=depth (in feet) of the sheeting body of water.
[0039] The hydraulic jump is the point of wave-breaking of the fastest waves that can exist at a given depth of water. The hydraulic jump itself is actually the break point of that wave. The breaking phenomenon results from a local convergence of energy. Any waves that appear upstream of the hydraulic jump in the supercritical area are unable to keep up with the flow, consequently they are swept downstream until they meet the area where the hydraulic jump occurs; now the flow is suddenly thicker and now the waves can suddenly travel faster. Concurrently, the down stream waves that can travel faster than the flow move upstream and meet at the hydraulic jump. Thus, the convergence of waves at this flux point leads to wave breaking. In terms of energy, the hydraulic jump is an energy transition point where energy of the flow abruptly changes from kinetic to potential. A hydraulic jump occurs when the Froude number is 1.
[0040] A stationary wave is a progressive wave that is travelling against the current and has a phase speed that exactly matches the speed of the current, thus, allowing the wave to appear stationary.
[0041] White water occurs due to wave breaking at the leading edge of the hydraulic jump where the flow transitions from critical to sub-critical. In the flow environment, remnant turbulence and air bubbles from wave breaking are merely swept downstream through the sub-critical area, and dissipate within a distance of 7 jump heights behind the hydraulic lump.
[0042] Separation is the point of zero wall friction whereas the sheet flow breaks away from the wall of the incline or other form or shape placed thereon. Flow separation results from differential losses of kinetic energy through the depth of the sheet flow. As the sheet flow proceeds up the incline it begins to decelerate, trading kinetic energy for gravitational potential energy. The portion of the sheet flow that is directly adjacent to the walls of the incline (the boundary layers) also suffer additional kinetic energy loss to wall friction. These additional friction losses cause the boundary layer to run out of kinetic energy and come to rest in a state of zero wall friction while the outer portion of the sheet flow still has residual kinetic energy left. At this point the outer portion of the sheet flow breaks away from the wall of the incline (separation) and continues on a ballistic trajectory with its remaining energy forming either a spill down or curl over back upon the upcoming flow.
[0043] The boundary layer is a region of retarded flow directly adjacent to a wall due to friction.
[0044] The separating streamline is the path taken by the outer portion of the sheet flow which does not come to rest under the influence of frictional effects, but breaks away from the wall surface at the point of separation.
[0045] Flow partitioning is the lateral division of flows having different hydraulic states.
[0046] A dividing streamline is the streamline defining the position of flow partitioning. The surface along which flows divide laterally between super critical and critical hydraulic states.
[0047] A bore is a progressive hydraulic jump which can appear stationary in a current when the bore speed is equal and opposite to the current.
[0048] A velocity gradient is a change in velocity with distance.
[0049] A pressure gradient is a change in pressure with distance.
[0050] Conforming flow occurs where the angle of incidence of the entire depth range of a body of water is (at a particular point relative to the inclined flow forming surface over which it flows) predominantly tangential to this surface. Consequently, water which flows upon an inclined surface can conform to gradual changes in inclination, e.g., curves, without causing the flow to separate. As a consequence of flow conformity, the downstream termination of an inclined surface will always physically direct and point the flow in a direction aligned with the downstream termination surface. The change in direction of a conforming flow can exceed 180 degrees.
[0051] FIG. 1 is a schematic drawing of one embodiment of an inclined ride surface 3 of a miniature simulated surfing game apparatus 100 having features and advantages of the present invention. Plan-sectional lines as revealed in FIG. 1 are solely for the purpose of indicating the three-dimensional shape in general, rather than being illustrative of specific frame, plan, and profile sections. In fact, it should be noted that a wide variety of dimensions and configurations for a containerless incline 4 are compatible with the principles of the present invention. Therefore, these principles should-not be construed to be limited to any particular configuration illustrated in the drawings or described herein.
[0052] The surfing game apparatus 100 generally comprises sub-surface structural support 2 , and ride surface 3 which is bounded by a downstream ridge edge (line) 4 , an upstream edge 5 , and side edges 6 a and 6 b . Ride surface 3 can be a skin over sub-surface structural support 2 , or can be integrated therewith so long as sufficiently smooth. If a skin, ride surface 3 can be fabricated of any of several of well known materials e.g., plastic; foam; thin shell concrete; formed metal; treated wood; fiberglass; tile; reinforced tension fabric; air, foam or water filled plastic or fabric bladders; or any such materials which are sufficiently smooth to minimize friction loss and which will withstand the surface loads involved.
[0053] Sub-surface structural support 2 can be sand/gravel/rock/plaster/fiberglass/plastic; truss and beam; compacted fill; tension pole; or any other well known method for firmly grounding and structurally supporting ride surface 3 in anticipation of flowing water and ride action figures thereon. The inclined shape of ride surface 3 need not be limited to the sloping inclined plane as illustrated in FIG. 1 . Ride surface 3 can gradually vary in curvature to assist in smooth water flow. For example, ride surface 3 can observe: upward concavity in longitudinal section parallel to the direction of water flow; or a longitudinal section comprised of upward concavity transitioning to an upward convexity; or a combination of straight, concave and convex longitudinal sections. Illustrations of several curved surface shapes are presented in succeeding figures.
[0054] Although numerous shapes are possible, one element constant to all preferred embodiments is that there is an inclined portion of sufficient length, width and degree of angle to enable a rider action-figure to perform water skimming maneuvers. At a minimum such angle is approximately seven degrees from the horizontal. Steeper angles of incline (with portions having a curvature extending past a 90 degree vertical) can provide more advanced ride characteristics and flow phenomena, to be discussed. At a minimum the length (from upstream edge 5 to downstream ridge edge 4 ) and width (from side edge 6 a to side edge 6 b ) of incline 1 is preferably greater than the respective length and width of the intended ride vehicle or body. The maximum dimensions of containerless incline 1 are capable of a broad range of values which depend more upon external factors, e.g., site constraints, financial resource, availability of water flow, etc, rather than specific restrictions on the structure itself.
[0055] In one case, a containerless incline having an angle of 20 degrees with respect to the horizontal was found to be suitable, to achieve the purposes of the present invention, when a flow of water having a depth of ⅛- 1/16 inches and a flow rate of 5-11 feet per second was flowing thereover. The length and width of such incline was approximately 10 inches by 20 inches, respectively. This corresponds to a scale wave surface of roughly 1:24 (½″=1′). Alternatively, smaller or larger scale wave surfaces may be created as desired. For example, it is anticipated that suitable miniature wave surfaces may be created in scales ranging form about 1:48 (¼″=1′) to about 1:12 (1″=1′). Correspondingly scaled surface action figures would preferably be provided for each such miniature surfing game. Of course, smaller or larger surfaces are also possible depending upon design preferences and costs.
[0056] Using such miniature live action surfing apparatus 100 an artificial miniature surfing wave can be generated having an unbroken yet rideable wave face comprising a smooth inclined mound of water having sufficient incline such that the gravity force component tangential to the wave surface balances and/or exceeds the counter-acting forces of drag acting on a miniature surf board. In this manner, sustained live-action riding may be achieved and water skimming maneuvers (e.g., action figure surfing) may be performed and vicariously enjoyed by the game participants. Breaking waves can also be generated having one portion that is broken or breaking and another portion that has a smooth surface, the transition from the smooth to the broken part of the wave occurring continuously over a region spanning a few wave heights and having a surfable transition area. The transition area is of particular interest to the wave-rider. The transition area is where the wave-rider performs optimum water skimming (e.g., surfing) maneuvers. The transition area is also where the wave face reaches its maximum angle of steepness.
[0057] Preferably the flow of water over the ride surface comprises a relatively thin sheet flow of high-velocity water. A sheet flow is where the water depth is sufficiently shallow such that the pressure disturbance caused by a rider/action-figure and his vehicle is influenced by the riding surface through a reaction force, whose effects on the rider and his vehicle are generally known as the “ground effect.” This provides for an inherently more stable ride, thus requiring less skill to catch and ride the wave.
[0058] In the sheet flow situation, the board is so close to a solid boundary, i.e., the flow bed or riding surface, that the pressure disturbance form the board does not have time to diminish before it comes in contact with the solid boundary. This results in the pressure disturbance transmitting through the fluid and directly to the ground. This allows the ground to participate, as a reaction wall, against the weight of the planing-vehicle (and optional action figure) and helps to support the vehicle by virtue of the ground effect. Thus, sheet flows are inherently more stable than deeper water flows. From the perspective of an accomplished user, the ground effect principal offers improved performance in the form of more responsive turns, increased speed, and tighter radius maneuvers resulting from lift augmentation that enables a decrease in vehicle planing area.
[0059] Sheet flows also can provide a conforming flow in the sense that the flow generally follows the contours of the riding surface. Therefore, this enables one to better control the shaping of the waves as they conform to the riding surface, while still achieving wave special effects when insufficient velocity at the boundary layer allows for flow separation from the contoured flow bed.
[0060] In this regard, it should be pointed out that, with a sheet flow up a containerless incline, no wave (in a technical sense) is necessarily required in order to enjoy a water attraction constructed in accordance with the principals of the present invention. All that is required is an incline of sufficient angle to allow the ride action figure to slide down the upwardly sheeting flow. Furthermore, intentionally induced drag can slow the action figure and send it back up the incline to permit additional maneuvers. Likewise, if desired, the ride action figure can be operated in a state of equilibrium (e.g., a stationary position with respect to the flow) by regulating drag relative to the uphill water flow.
[0061] FIG. 2 shows containerless incline 100 of FIG. 1 in operation. The basic operation of this device requires a suitable flow source 7 (e.g., pump, hose or elevated reservoir) forming a supercritical sheet flow of water 8 in predominately singular flow direction 9 (as indicated by arrows) over ride surface 3 (whose lateral edges 6 and downstream ridge edge 4 are shown in dashed lines) to form an inclined body of water upon which a rider 10 performs water skimming maneuvers. A small recirculation pump is preferably used to achieve the desired flow of water upward over the ride surface 3 .
[0062] The orientation and ride path of rider action FIG. 10 may be controlled through a balance of forces, e.g., gravity, drag, hydrodynamic lift, buoyancy, and induced kinetic motion. Gravitational forces pull downward upon the ride action figure tending to drive it down the inclined ride surface 3 . Simultaneously, hydraulic drag forces tends to push the ride action FIG. 10 higher up the ride surface. Non-equilibrium riding maneuvers such as turns, cross-slope motion and oscillating between different elevations on the “wave-like” surface are made possible by the interaction between the respective forces as described above and the use of kinetic energy of the ride action figure.
[0063] There is no maximum depth for supercritical flow 8 , although shallow flows are preferred with a practical minimum of approximately 1/16″. The preferred relation of flow depth to flow speed can be expressed in terms of a preferred Froude number. A practical regime of Froude numbers for containerless incline 1 is from 2 through 75, with the preferred range between 4 and 25 for the entire sheet. Flows with Froude numbers greater than 1 and less than 2 are prone to contamination from pulsating motions known as “roll waves” which are actually vortices rather than waves. Sheet water flows are preferred because shallow flows upon a containerless incline 1 will: (a) increase vehicle stability and reduce capsizing or sinking of vehicles in a deep water flow; (b) reduce water maintenance due to decrease in volume of water treated; (c) reduce energy costs by minimizing the amount of pumped water; (d) reduce the requisite skill level of participants as the result of improved ride stability due to “ground effects”; and (e) improved ride performance (i.e., lift and speed) due to ground effects.
[0064] Of particular note is how containerless incline 1 will permit water run-off 11 (as indicated by downward curving lines with dotted ends), to cascade from side edges 6 and over downstream ridge edge 4 . As noted above, the “containerless” feature of the present invention is important in achieving the desired sheet flow characteristics. Essentially, the lack of lateral container walls permits an unbounded flow of water up the inclined riding surface 3 . So long as the stream lines of the water are coherent and substantially parallel to one another and to the lateral edges 6 a and 6 b of the riding surface 3 , the integrity (i.e., velocity and smooth surface flow characteristics) of the sheeting water flow is maintained. Consequently, a flow which is not side restrained advantageously avoids lateral boundary layer of effects and permits side water run-off, thus, maintaining a smooth flow and unimpaired velocity across the entire sheet of water. Furthermore, as pointed out above, the principles of the present invention apply equally well to an incline surface of various configurations, not necessarily with parallel sides 6 a and 6 b . Conversely, a side container wall creates a boundary layer effect which increases the static pressure of the water in the area of the container side wall, decreases the velocity of the sheet flow, and results in a disturbed surface flow. With a container or side wall, such boundary layer effect and disturbance is inevitable due to friction forces and the resultant propagation of oblique waves, both of which make difficult the maintenance of desirable parallel and coherent water streamlines. However, that is not to say that the invention cannot be practiced using an incline with side walls. Such an embodiment will function for the intended purpose, however, it will have some boundary-layer-induced flow disturbances.
[0065] Preferably, the propagation of oblique waves and other turbulent flow is eliminated by either eliminating side walls and/or by maintaining a low static pressure along the lateral edges of the sheet flow. On the other hand, it should be noted that the disadvantages of the boundary layer effect are greatly minimized when the sheet flow is on a downwardly inclined surface. This is because turbulence is less likely to be propagated upstream against the force of gravity. Furthermore, any surface disturbance that may form is more likely to be swept downstream by the greater kinetic energy of the main flow of water when compared to that of the turbulent flow, such kinetic energy resulting from the gravity component of the downward flow.
[0066] Moreover, by extending ride surface 3 , increasing or decreasing its elevation, adding to its surface area, warping its contour, adding horizontal and declining surfaces and/or by changing the direction, speed and thickness of entering supercritical water flow 8 , the diverse sheet flow attractions as herein described will result.
[0067] FIG. 3 is a perspective view of a marionette-style simulated surfing game apparatus having features and advantages of the present invention. For brevity of description and ease of understanding, similar features are denoted using similar and/or identical reference numerals. Multiple variations of the same or similar features may also be denoted using the same reference numerals and the structures thereof are as fairly illustrated and described. Optional reservoir 27 is provided for containing a static body of water and providing an injected sheet flow 8 upon ride surface 3 via nozzle 31 . The depth of water in reservoir 27 is preferably adjusted by adding water from a source 7 until a desired amount of head or pressure is achieved at the nozzle 31 .
[0068] Surf action figures 10 are of a marionette style and are suspending on or above the ride surface using one or more strings ( 1 , 2 , 4 , etc.) as illustrated. A suitable pole, stick or wire 40 may be used by each play participant 20 to control the relative orientation and position of each play action figure and its interaction with the sheet water flow on the ride surface 3 . An optional grate/net 98 may also be provided to catch action figures 10 that wipe out or get swept up in the flow 8 .
[0069] FIG. 4A is a perspective view of a magnetically operated simulated surfing game apparatus having features and advantages of the present invention. For brevity of description and ease of understanding, similar features are denoted using similar and/or identical reference numerals. Multiple variations of the same or similar features may also be denoted using the same reference numerals and the structures thereof are as fairly illustrated and described. Optional elevated support structure 2 is provided for supporting the ride surface 3 at an elevation above ground level.
[0070] Magnetically actuated surf action figures 10 are provided on the ride surface 3 and are controlled by play participants 20 using one or more magnets disposed underneath the ride surface 3 . In particular, the support structure has one or more openings therein (not shown) into which may be inserted an elongated pole or stick having affixed thereto a permanent or electric magnet. The magnetic forces created thereby are caused to interact with a similarly sized and configured magnet at the base of each surf action figure. In this manner, the stick 40 may be used by each play participant 20 to control the relative orientation and position of each play action figure and its interaction with the sheet water flow on the ride surface 3 . FIG. 4B is a detail view of a magnetically operated surf toy action figure and associated actuator for use with the simulated surfing game apparatus of FIG. 4A . Optionally, a containment/recirculation system may be provided as illustrated in FIG. 4 . In this optional embodiment, water flow 8 is contained by side walls 99 which funnel spent flow 8 into a recovery pool 97 . This water is then drawn through a conduit 96 and recirculated by a pump 95 .
[0071] FIG. 5 is a perspective view of a radio remote controlled simulated surfing game apparatus having features and advantages of the present invention. For brevity of description and ease of understanding, similar features are denoted using similar and/or identical reference numerals. Multiple variations of the same or similar features may also be denoted using the same reference numerals and the structures thereof are as fairly illustrated and described. In this case, sheet water flow 8 is provided upon ride surface 3 by a water source 7 configured in the form of an elongated nozzle connected to a pressurized water source 47 , such as an ordinary garden hose. The speed and depth of the sheet water flow can thus be adjusted by adjusting the water pressure provided by the garden hose 47 or other source.
[0072] Surf action figures 10 are preferably constructed so as to be capable of being controlled using radio frequency broadcasts from a transmitter 53 or similar “wireless” communications device as are well-known in the art. In particular, each action FIG. 10 includes a receiver and at least one actuator for causing one or more desired maneuvers, such as weight shifting, rudder and/or drag control, leaning, etc. The radio control may be of conventional design, such as of the type used for other radio-controlled model vehicles and aircraft. In one embodiment disclosed herein, the steering control is a three-position control, straight ahead, left turn and right turn. However, if desired, proportional control of the turning may readily be provided, as is well known in the art. In this manner each play participant 20 can control the relative orientation and position of each play action figure and its interaction with the sheet water flow on the ride surface 3 .
[0073] FIG. 6A is a detail view of one embodiment of a radio remote controlled surf toy action FIG. 10 for use with the simulated surfing game apparatus of FIG. 5 . The surf action FIG. 10 generally comprises a plastic molded toy action FIG. 63 pivotally mounted to a miniature surf board or other sheet flow riding vehicle 65 . The action FIG. 63 is preferably mounted on a base 67 which is pivotally mounted to the board 65 at pin 69 . Pin 69 is preferably rotatable clockwise and/or counter-clockwise directions in response to a radio frequency broadcast or other wireless communications protocol received by antenna 59 .
[0074] FIG. 6B is a detail view of the radio remote controlled surf toy action FIG. 10 of FIG. 6A making a back-side turn. In this case, the base 67 of the surf action FIG. 10 is remotely actuated and rotated counter-clockwise, thereby shifting the weight of the action FIG. 63 to the back-side edge of the board 65 . This induces the toy action figure to perform a back-side turning maneuver.
[0075] FIG. 6C is a detail view of the radio remote controlled surf toy action FIG. 10 of FIG. 6A making a front-side turn. In this case, the base 67 of the surf action FIG. 10 is remotely actuated and rotated clockwise, thereby shifting the weight of the action FIG. 63 to the front-side edge of the board 65 . This induces the toy action figure to perform a front-side turning maneuver.
[0076] FIG. 7 is a perspective view of an alternative embodiment of a simulated surfing game apparatus 500 having features and advantages of the present invention. In particular, it may be seen that a toy surfing action FIG. 10 is caused to traverse across and perform live-action water skimming maneuvers upon an uphill sheet flow of water 8 . Surf action FIG. 10 may be controlled using any one or more of the control mechanisms or methods described above and/or obvious variations thereof as will become readily apparent to those skilled in the art. Optionally, surf action FIG. 10 may be pre-programmed from among a selection of preset and/or custom maneuvers. Optionally, surf action FIG. 10 may be programmed or otherwise configured to perform random or varying surfing maneuvers. Again, many variations and modifications are possible. A game may also be played whereby play participants try to see or bet on whose surf action figure is able to stay upright on the ride surface the longest without wiping out. Multiple surf action figures of identical or varying design may be used for this purpose.
[0077] FIG. 8 is a perspective view of a further alternative embodiment of a simulated surfing game apparatus having features and advantages of the present invention. In this case the ride surface is formed so as to create a miniature curling wave 75 , as illustrated. Again, a game may be played whereby play participants try to see or bet on whose surf action FIG. 10 can stay upright and/or perform various surfing tricks (e.g., tube riding, aerials, floaters and the like) inside the curl of the wave without wiping or getting tumbled by the spilling wave 75 . Multiple surf action figures of identical or varying design may be used for this purpose.
[0078] Of course, those skilled in the art will recognize that the invention may be used to achieve a wide variety of desirable wave shapes or “flow shapes” using sheet water flow over a suitably shaped forming surface. The majority of flow manifestations created by the subject invention are technically not waves. They may appear like gravity waves breaking obliquely to a beach; however, these sheet flow manifestations are distinct hydrodynamic phenomena caused by the interaction of four dynamics: (1) the subject invention's unique surface architecture; (2) the trajectory of the water relative to the flow forming surface; (3) flow separation from this surface; and (4) changes in hydraulic state of the flow (i.e., supercritical, critical or subcritical) upon this surface.
[0079] Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.
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The present invention provides a miniature live-action surfing attraction and associated surf game specifically adapted for use with one or more surf toy action figures. The surf toy action figures are mountable to a surf board appropriately sized and weighted to provide relatively stable or semi-stable surf-riding action upon a sheet flow of water flowing up an inclined ride surface of the reduced scale attraction. Various surf action figures may be set free upon the ride surface, or they may be constrained or partially constrained by wires, strings, magnets or the like, as desired. Alternatively, or in addition, they may be controlled via a remote control, or radio control transmitter, as desired. Thus, a fun and entertaining game is created that provides realistic live-action surfing within a relatively small or confined area.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an LED lamp. More particularly, the invention relates to an LED diffusion assembly for use in various LED applications where diffusion of the emitted light is desired.
2. Description of the Prior Art
As the ability to effectively diffuse the light emitted by an LED becomes more efficient, their usefulness in various applications similarly increases. For example, LEDs are now commonly found in automobile tail lights and commercial signs. The use of LEDs in these applications results in the replacement of larger more expensive light sources with smaller, high output light sources without sacrificing the desired illumination levels.
As such, a need continually exists for LED diffusion arrangements offering improved and efficient dispersion of light generated by LEDs. The present invention provides such an LED diffusion assembly.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an LED diffusion assembly having a concave tip portion shaped and dimensioned for the diffusion of light emitted thereby. The assembly includes a bulb portion and first and second leads extending within the bulb portion. The assembly also includes LED dice embedded in the bulb portion and coupled to the first and second leads in a manner allowing for transfer of electrical energy to the LED dice. The bulb portion includes a concave tip substantially opposite the LED dice, wherein the concave tip is shaped and dimensioned for diffusing light emitted by the LED dice.
It is also an object of the present invention to provide an LED diffusion assembly wherein the bulb portion is formed from an epoxy resin.
It is another object of the present invention to provide an LED diffusion assembly wherein the bulb portion is formed from glass.
It is a further object of the present invention to provide an LED diffusion assembly wherein a first end of the first lead is embedded within the bulb portion and coupled to the LED dice and a first end of the second lead is embedded within the bulb portion and coupled to the LED dice.
It is still another object of the present invention to provide an LED diffusion assembly wherein the concave tip includes a plurality of facets.
It is still a further object of the present invention to provide an LED diffusion assembly wherein the concave tip includes a diameter D, a height H and a concave angle α.
It is also an object of the present invention to provide an LED diffusion assembly wherein α is preferably approximately between 85 degrees and 170 degrees.
It is another object of the present invention to provide an LED diffusion assembly wherein D is greater than approximately 2 mm.
It is a further object of the present invention to provide an LED diffusion assembly wherein H/D is less than approximately 58%.
It is also an object of the present invention to provide an LED diffusion assembly wherein the minimum Culer convex radius is approximately 1 mm.
It is yet another object of the present invention to provide an LED diffusion assembly wherein the concave tip is shaped as a diamond pavilion having a diameter D, a height H and a concave angle α.
It is a further object of the present invention to provide an LED diffusion assembly wherein α is preferably approximately between 85 degrees and 170 degrees.
It is also an object of the present invention to provide an LED diffusion assembly wherein the bulb portion is formed as a composite.
Other objects and advantages of the present invention will become apparent from the following detailed description when viewed in conjunction with the accompanying drawings, which set forth certain embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an LED diffusion assembly in accordance with the present invention.
FIG. 2 is a top view of the concave tip in accordance with the present invention.
FIG. 3 is cross sectional view of the concave tip in accordance with the present invention.
FIGS. 4 and 5 are perspective views of sockets which may be used in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The detailed embodiments of the present invention are disclosed herein. It should be understood, however, that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, the details disclosed herein are not to be interpreted as limited, but merely as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention.
With reference to FIG. 1, an LED diffusion assembly 10 is disclosed. The LED diffusion assembly 10 is generally composed of an LED lamp 12 mounted within a socket 14 . The LED lamp 12 has a concave tip portion 16 shaped and dimensioned for the diffusion of light emitted thereby.
The LED lamp 12 generally includes a bulb portion 18 . While a specific shaped bulb portion is contemplated in accordance with a preferred embodiment of the present invention, other shapes may be used without departing from the spirit of the present invention. The bulb portion 18 is generally formed from epoxy resin, or any other appropriate resin or glass known to those of skill in the art. Similarly, a composite material may be used in accordance with the present invention. Such a composite material would be formed from different materials in layers, or some other form, through the use of adhesive, fusion, brazing, etc.
The bulb portion 18 includes generally smooth sides 20 with a concave tip portion 16 . The concave tip portion 16 will be discussed below in greater detail. The side surfaces of the bulb portion 18 may be treated in various ways know to those skilled in the art to provide desired illumination. With the exception of the concave tip portion 16 discussed below in substantial detail, the manner in which the bulb portion 18 is treated is not critical and may be readily varied to suit specific needs without departing from the spirit of the present invention.
The LED lamp 12 further includes a pair of leads 22 a , 22 b . One end 23 a , 23 b of each lead 22 a , 22 b extends outside of the bulb portion 18 and the other end 25 a , 25 b of each lead is embedded in the bulb portion 18 . Finally, the LED lamp 12 includes a pair of LED chips (dice) 24 a , 24 b respectively connected to the ends 25 a , 25 b of the first and second leads 22 a , 22 b embedded in the bulb portion 18 . The LED dice 24 a , 24 b are connected to the first and second leads 22 a , 22 b using conventional techniques in such a manner that electrical power may be selectively supplied to the LED dice 24 a , 24 b.
The present LED lamp 12 is provided with at least one LED dice for emitting light of appropriate color (wavelength). While a preferred embodiment discloses an LED lamp using a pair of LED dice, those skilled in the art will appreciate the fact that the LED lamp may use one or more LED dice without departing from the spirit of the present invention. For example, an LED emitting a requested color of light can be obtained by appropriately arranging a plurality of red, green, and blue LED dice. In accordance with a preferred embodiment of the present invention, the diameter of the bulb portion is approximately 3 mm through 10 mm, though obviously, the diameter can be larger or smaller than these values without departing from the spirit of the present invention.
Referring to the concave tip portion 16 of the LED lamp 12 disclosed in FIGS. 2 and 3, it is generally formed in such a way to diffuse light as it is emitted from the LED dice 24 a , 24 b . In accordance with a preferred embodiment as disclosed in FIGS. 2 and 3, the concave tip portion 16 generally takes the form a diamond pavilion having a diameter D, a height H and a concave angle α. Based upon the facets of the diamond pavilion defining the concave tip portion 16 of the LED lamp 12 , light emitted by the LED dice 24 a , 24 b , and traveling within the epoxying making up the bulb shaped portion 18 , is deflected at a greater rate than the same light traveling through air. As such, when the light emitted by the LED dice 24 a , 24 b exits the epoxy of the bulb shaped portion 18 , the light bends away into the air.
In accordance with the preferred embodiment described above, α is preferably approximately between 85 degrees and 170 degrees. In addition, D is greater than approximately 2 mm and the depth (i.e., H/D) is less than approximately 58%. Finally, the minimum Culer convex radius is approximately 1 mm. While these ranges are given in accordance with a preferred embodiment, those skilled in the art will appreciate the possible variations within the spirit of the present invention.
Various sockets 14 a , 14 b which may be used in accordance with present LED lamp 12 are disclosed in FIGS. 4 to 5 . Each of the circular sockets 14 a , 14 b repeatedly comprises a flange 26 a , 26 b provided at the top or bottom of the socket 14 a , 14 b , an insulating material 28 a , 28 b incorporated into the flange 26 a , 26 b , and two opposing electrodes 30 a , 32 a , 30 b , 32 b set inside the insulating material 28 a , 28 b as shown in FIGS. 4 and 5. The LED lamp 12 is inserted into the socket 14 a , 14 b , making a connection between the electrodes 30 a , 32 a , 30 b , 32 b and the leads 22 a , 22 b . The two leads 22 a , 22 b extending downward from the base of the inserted LED lamp 12 are bent upward along the outside of the lamp 12 . In this state, the lamp 12 is inserted into either socket 14 a , 14 b in such way that the two leads 22 a , 22 b respectively connect with the two electrodes 30 a , 32 a , 30 b , 32 b . These electrodes are connected to the power source (not shown) through an appropriate conductor. Thus, the socket 14 a , 14 b can be fixed to the power source, and only the LED lamp 12 can be optionally removed from the power source or exchanged.
By providing the present LED assembly 10 with a concave tip portion 16 having a plurality of facets cut therein, the present invention is capable of effectively diffusing the light generated by the LED dice 24 a , 24 b.
While the preferred embodiments have been shown and described, it will be understood that there is no intent to limit the invention by such disclosure, but rather, is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention as defined in the appended claims.
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An LED diffusion assembly having a concave tip portion shaped and dimensioned for the diffusion of light emitted thereby. The assembly includes a bulb portion and first and second leads extending within the bulb shaped portion. The assembly also includes LED dice embedded in the bulb shaped portion and coupled to the first and second leads in a manner allowing for transfer of electrical energy to the LED dice. The bulb portion includes a concave tip substantially opposite the LED dice, wherein the concave tip is shaped and dimensioned for diffusing light emitted by the LED dice.
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