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RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application Ser. No. 61/483,586 filed May 6, 2011, as well as U.S. Provisional Application Ser. No. 61/487,372 filed May 18, 2011, the contents of both of which are incorporated herein by reference in their entireties as if set forth in full.
BACKGROUND
1. Field of the Invention
The embodiments described herein relate generally to the field of radio-frequency identification (RFID) devices, and more particularly, to RFID switch tags.
2. Related Art
Conventional RFID tags lack the ability to be deactivated. However, there are certain situations where it is actually desirable to have an RFID tag deactivated. For example, in the context of traveling, RFID tags will often contain sensitive personal information stored within, for instance, an e-Passport, a visa, or a national identification card. Such information may contain the traveler's name, birth date, place of birth, nationality, and/or biometric information associated with that traveler. This information is intended to be read only by customs officials or other governmental authorities when the traveler enters or exits a country. However, since the read range of RFID tags can extend up to 30 feet, since an RFID tag does not need to be directly in the line of sight of an RFID reader, this sensitive information may be read by any number of unauthorized individuals as the individual walks through a train station or an airport. Unless the traveler houses his travel documents within a Faraday shield or other type of electro-resistant casing (which most travelers do not have), the sensitive information stored within the RFID tag remains perpetually at risk of being read by these unauthorized parties.
As a second example, consider RFID tags that are installed within automobiles, where such tags are used to facilitate automatic billing for the repeated use of certain toll-roads. In some of these toll-roads, the use of a car-pool lane is considered free of charge (which may be validly used, for example, when the automobile is housing at least one passenger other than the driver). Since a driver's RFID tag may not be deactivated, however, the RFID tag may respond to an interrogation signal issued from the toll-gate even when the driver has validly used the carpool lane. The result is that the driver may be billed for using the toll-road even when such use should have been considered free of charge because of the driver's valid use of the car-pool lane.
What is needed is a system for an RFID tag that may be easily activated or deactivated. Ideally, the system should be versatile and provide a clear sensory indication of the operational status of the RFID tag (i.e., activated or deactivated).
SUMMARY
Various embodiments of the present invention are directed to RFID switch devices. Such RFID switch devices advantageously enable manual activation/deactivation of the RF module. The RFID switch device may include a RF module with an integrated circuit adapted to ohmically connect to a substantially coplanar conductive trace pattern, as well as booster antenna for extending the operational range of the RFID device. The operational range of the RFID switch device may be extended when a region of the booster antenna overlaps a region of the conductive trace pattern on the RF module via inductive or capacitive coupling. In some embodiments, all or a portion of the booster antenna may at least partially shield the RF module when the RFID switch device is in an inactive state. The RFID switch device may further include a visual indicator displaying a first color if the RFID switch device is in an active state and/or a second color if the RFID switch device is in an inactive state.
In a first exemplary aspect, an RFID device is disclosed. In one embodiment, the RFID device comprises: a booster antenna adapted to extend the operational range of the RFID device; an RF module comprising an integrated circuit and a set of one or more conductive traces, wherein at least one conductive trace of said set of one or more conductive traces is adapted to electrically couple to a coupling region of the booster antenna when the coupling region of the booster antenna is located in a first position relative to said set of one or more conductive traces; and a switching mechanism adapted to change the position of the coupling region of the booster antenna relative to the position of said at least one conductive trace.
In a second exemplary aspect, an RFID transponder is disclosed. In one embodiment, the RFID transponder comprises: a first substrate comprising a first conductive trace pattern, wherein at least a portion of the first substrate is adapted to serve as an antenna for the RFID transponder; a second substrate comprising an integrated circuit and a second conductive trace pattern, wherein at least a portion of the second conductive trace pattern is adapted to electrically couple with at least a portion of the first conductive trace pattern when the first substrate is located in a first position relative to the second substrate; and a switching mechanism adapted to switch the position of the first substrate between a first position and at least a second position.
In a third exemplary aspect, an RFID device is disclosed. In one embodiment, the RFID device comprises: a booster antenna adapted to extend the operational range of the RFID device; a first RF module comprising a first integrated circuit and a first conductive trace pattern, wherein at least a portion of the first conductive trace pattern is adapted to electrically couple to a coupling region of the booster antenna when the coupling region of the booster antenna is located in a first position relative to the first conductive trace pattern; a second RF module comprising a second integrated circuit and a second conductive trace pattern, wherein at least a portion of the second conductive trace pattern is adapted to electrically couple to the coupling region of the booster antenna when the coupling region of the booster antenna is located in a second position relative to the second conductive trace pattern; and a switching mechanism adapted to change the position of the coupling region of the booster antenna relative to the positions of said first and second RF modules.
In a fourth exemplary aspect, an RFID device is disclosed. In one embodiment, the RFID device comprises: a first booster antenna adapted to extend the operational range of a first RF module; a second booster antenna adapted to extend the operational range of a second RF module; the first RF module comprising a first integrated circuit and a first conductive trace pattern, wherein at least a portion of the first conductive trace pattern is adapted to electrically couple to a coupling region of the first booster antenna when the coupling region of the first booster antenna is located in a first position relative to the first conductive trace pattern; a second RF module comprising a second integrated circuit and a second conductive trace pattern, wherein at least a portion of the second conductive trace pattern is adapted to electrically couple to the coupling region of the second booster antenna when the coupling region of the second booster antenna is located in a second position relative to the second conductive trace pattern; and a switching mechanism adapted to change the position of the coupling region of the first booster antenna relative to the first RF module, and the position of the coupling region of the second booster antenna relative to the second RF module.
In a fifth exemplary aspect, an RFID device is disclosed. In one embodiment, the RFID device comprises: a first booster antenna adapted to extend the operational range of an RF module as used with a first RFID service; a second booster antenna adapted to extend the operational range of the RF module as used with a second RFID service; the RF module comprising an integrated circuit and a conductive trace pattern, wherein at least a portion of the conductive trace pattern is adapted to electrically couple to a coupling region of the first booster antenna when the coupling region of the first booster antenna is located in a first position relative to the conductive trace pattern; and wherein at least a portion of the conductive trace pattern is adapted to electrically couple to a coupling region of the second booster antenna when the coupling region of the second booster antenna is located in a second position relative to the conductive trace pattern; and a switching mechanism adapted to change the position of the RF module relative to the respective coupling regions of the first and second booster antennas.
Other features and advantages of the present invention should become apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Various embodiments disclosed herein are described in detail with reference to the following figures. The drawings are provided for purposes of illustration only and merely depict typical or exemplary embodiments. These drawings are provided to facilitate the reader's understanding of the invention and shall not be considered limiting of the breadth, scope, or applicability of the embodiments. It should be noted that for clarity and ease of illustration these drawings are not necessarily made to scale.
FIG. 1 is a block diagram illustrating an exemplary RFID system according to one embodiment of the present invention.
FIG. 2A is a block diagram illustrating an exemplary RFID switch tag with its RF module located in a first position relative to its booster antenna according to one embodiment of the present invention.
FIG. 2B is a block diagram of the exemplary RFID switch tag with its RF module located in a second position relative to its booster antenna according to the embodiment depicted in FIG. 2A .
FIG. 2C is a block diagram of the RFID switch tag depicted in FIGS. 2A and 2B as depicted within an exemplary casing featuring a position-altering mechanism according to one embodiment of the present invention.
FIG. 3 is a block diagram illustrating an exemplary RFID switch tag including two RF modules and a single booster antenna according to one embodiment of the present invention.
FIG. 4 is a block diagram illustrating an exemplary RFID switch tag including two RF modules and two corresponding booster antennas according to one embodiment of the present invention.
FIG. 5 is a block diagram illustrating an exemplary RFID switch tag including a single RF module and two booster antennas that are tuned to different frequencies according to one embodiment of the present invention.
FIG. 6A is a front-side view of an exemplary switch-activated RFID tag according to one embodiment of the present invention.
FIG. 6B is a perspective view of the back side of the exemplary switch-activated RFID tag according to the embodiment depicted in FIG. 6A .
FIG. 7A is a back-side view of an exemplary circular-shaped and rotatable RFID switch tag in a first position according to one embodiment of the present invention.
FIG. 7B is a back-side view of the exemplary circular-shaped and rotatable RFID switch tag in a second position according to the embodiment depicted in FIG. 7A .
FIG. 7C is a front-side view of the exemplary circular-shaped and rotatable RFID switch tag depicted in FIGS. 7A and 7B .
FIG. 8A is a perspective view of the back side of an exemplary triangular-shaped and rotatable RFID switch tag in a first position according to one embodiment of the present invention.
FIG. 8B is a back-side view of the exemplary triangular-shaped and rotatable RFID switch tag in a second position according to the embodiment depicted in FIG. 8A .
FIG. 8C is a front-side of the exemplary triangular-shaped and rotatable RFID switch tag depicted in FIGS. 8A and 8B .
FIG. 9A is a perspective view of the back side of an exemplary switch-activated RFID tag according to one embodiment of the present invention.
FIG. 9B is a front-side view of the exemplary switch-activated RFID tag depicted in FIG. 9A .
FIG. 10 is a perspective view of an exemplary slide-activated RFID tag according to one embodiment of the present invention.
DETAILED DESCRIPTION
RFID is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. The technology relies on cooperation between an RFID reader and an RFID tag. RFID tags can be applied to or incorporated within a variety of products, packaging, and identification mechanisms for the purpose of identification and tracking using radio waves. For example, RFID is used in enterprise supply chain management to improve the efficiency of inventory tracking and management. Some tags can be read from several meters away and beyond the line of sight of the RFID reader.
Most RFID tags contain at least two parts: One is an integrated circuit for storing and processing information, for modulating and demodulating a radio-frequency (RF) signal, and for performing other specialized functions. The second is an antenna for receiving and transmitting the signal. As the name implies, RFID tags are often used to store an identifier that can be used to identify the item to which the tag is attached or incorporated. An RFID tag may also contain non-volatile memory for storing additional data as well. In some cases, the memory may be writable or electrically erasable programmable read-only memory (i.e., EEPROM).
Most RFID systems use a modulation technique known as backscatter to enable the tags to communicate with the reader or interrogator. In a backscatter system, the interrogator transmits a Radio Frequency (RF) carrier signal that is reflected by the RFID tag. In order to communicate data back to the interrogator, the tag alternately reflects the RF carrier signal in a pattern understood by the interrogator. In certain systems, the interrogator can include its own carrier generation circuitry to generate a signal that can be modulated with data to be transmitted to the interrogator.
RFID tags come in one of three types: passive, active, and semi passive. Passive RFID tags have no internal power supply. The minute electrical current induced in the antenna by the incoming RF signal from the interrogator provides just enough power for the, e.g., CMOS integrated circuit in the tag to power up and transmit a response. Most passive tags transmit a signal by backscattering the carrier wave from the reader. This means that the antenna has to be designed both to collect power from the incoming signal and also to transmit the outbound backscatter signal.
Passive tags have practical read distances ranging from about 10 cm (4 in.) (ISO 14443) up to a few meters (Electronic Product Code (EPC) and ISO 18000-6), depending on the chosen radio frequency and antenna design/size. The lack of an onboard power supply means that the device can be quite small. For example, commercially available products exist that can be embedded in a sticker, or under the skin in the case of low frequency RFID tags.
Unlike passive RFID tags, active RFID tags have their own internal power source, which is used to power the integrated circuits and to broadcast the response signal to the reader. Communications from active tags to readers is typically much more reliable, i.e., fewer errors, than from passive tags. Active tags, due to their on-board power supply, may also transmit at higher power levels than passive tags, allowing them to be more robust in “RF challenged” environments, such as high environments, humidity or with dampening targets (including humans/cattle, which contain mostly water), reflective targets from metal (shipping containers, vehicles), or at longer distances. In turn, active tags are generally bigger, caused by battery volume, and more expensive to manufacture, caused by battery price. Many active tags today have operational ranges of hundreds of meters, and a battery life of up to 10 years. Active tags can include larger memories than passive tags, and may include the ability to store additional information received from the reader, although this is also possible with passive tags.
Semi-passive tags are similar to active tags in that they have their own power source, but the battery only powers the microchip and does not power the broadcasting of a signal. The response is usually powered by means of backscattering the RF energy from the reader, where energy is reflected back to the reader as with passive tags. An additional application for the battery is to power data storage. The battery-assisted reception circuitry of semi-passive tags leads to greater sensitivity than passive tags, typically 100 times more. The enhanced sensitivity can be leveraged as increased range (by one magnitude) and/or as enhanced read reliability (by reducing bit error rate at least one magnitude).
FIG. 1 is a block diagram illustrating an exemplary RFID system according to one embodiment of the present invention. As shown by this figure, RFID interrogator 102 communicates with one or more RFID tags 110 . Data can be exchanged between interrogator 102 and RFID tag 110 via radio transmit signal 108 and radio receive signal 112 . RFID interrogator 102 may include RF transceiver 104 , which contains both transmitter and receiver electronics configured to respectively generate and receive radio transit signal 108 and radio receive signal 112 via antenna 106 . The exchange of data may be accomplished via electromagnetic or electrostatic coupling in the RF spectrum in combination with various modulation and encoding schemes.
RFID tag 110 can be a transponder attached to an object of interest and serve as an information storage mechanism. The RFID tag 110 may itself contain an RF module 120 (including an integrated circuit 122 and conductive trace pattern 124 ) as well as its own antenna 126 . All or a portion of the antenna 126 may be adapted to interact with the conductive trace pattern 124 in order to gather energy from the RF field to enable the device circuit 122 to function. In some embodiments, the antenna 126 used to gather the RF energy may be in a different plane as that of the integrated circuit 122 .
The data in the transmit signal 108 and receive signals 112 may be contained in one or more bits for the purpose of providing identification and other information relevant to the particular RFID tag application. When RFID tag 110 passes within the range of the radio frequency magnetic or electromagnetic field emitted by antenna 106 , RFID tag 110 is excited and transmits data back to RF interrogator 102 . A change in the impedance of RFID tag 110 can be used to signal the data to RF interrogator 102 via the receive signal 112 . The impedance change in RFID tag 110 can be caused by producing a short circuit across the tag's antenna connections (not shown) in bursts of very short duration. RF transceiver 104 can sense the impedance change as a change in the level of reflected or backscattered energy arriving at antenna 106 .
Digital electronics 114 (which in some embodiments comprises a microprocessor with RAM) performs decoding and reading of the receive signal 112 . Similarly, digital electronics 114 performs the coding of the transmit signal 108 . Thus, RF interrogator 102 facilitates the reading or writing of data to RFID tags, e.g. RFID tag 110 that are within range of the RF field emitted by antenna 104 . Together, RF transceiver 104 and digital electronics 114 comprise reader 118 . Finally, digital electronics 114 and can be interfaced with an integral display and/or provide a parallel or serial communications interface to a host computer or industrial controller, e.g. host computer 116 .
As stated above, conventional RFID devices lack the ability to be manually activated or deactivated. Various embodiments of the present invention are therefore directed to an RFID switch tag adapted to allow a user to manually change the operational state of the RFID device by activation of a lever, switch, knob, slider, rotating member, or other similar structure.
As shown generally by the embodiments depicted in FIGS. 2A-2C , a tag may provided that includes an RF module, strap, or interposer, as well as a booster antenna 210 . The RF module 220 may comprise an RFID integrated circuit in an ohmic connection to impedance matched conductive trace pattern in the same plane as the integrated circuit. Even though the RF module 220 is fully functional and testable, it may have a limited range of operation due to the small surface area of the conductive trace pattern.
According to one embodiment, the operational range of the RF module 220 can be increased by conductive or inductive coupling. For example, an impedance matched booster antenna 210 can be used in conjunction with the RF module 220 . In one embodiment, this booster antenna 210 consists of a conductive trace pattern on a substrate. In this example, there is no RF device on the booster antenna 210 . Rather, the RF module 220 and booster antenna 210 are provided with an area where they can overlap so that the capacitive or inductive coupling of energy occurs. The RF energy gathered from the booster antenna 210 may be transferred through the RF module substrate and conducted into the RF module 220 . This is illustrated in FIG. 2A . As shown, the RF module 220 may be positioned relative to the booster antenna 210 such that RF energy gathered via the booster antenna 210 is transferred to the RF module 220 .
While not shown, RF module 220 may comprise an RFID integrated circuit and a conductive trace pattern. These trace patterns can then be either inductively or capacitively coupled with a booster antenna 210 . For optimal performance, the booster antenna 210 may be matched with the RFID integrated circuit inputs. If RF module 220 is displaced or not sufficiently coupled with antenna 210 , then the operational range of the tag can be significantly reduced.
Thus, the placement of the RF module 220 with respect to the booster antenna 210 may alter the operational range and performance of the RFID tag 110 . This is illustrated in FIG. 2B . In FIG. 2B , the relative positions of the RF module 220 and the booster antenna 210 are different than the arrangement shown in FIG. 2A . In the arrangement of FIG. 2B , a smaller portion, or none, of the RF energy collected by the booster antenna 210 is transferred to the RF module 220 . In this manner, the effective operational range of the RFID tag 110 may be reduced as compared to the arrangement of FIG. 2A . In fact, because RF module 220 is completely or at least partially shielded by a portion of antenna 210 , RFID communications between the RFID tag 110 and the RFID reader interrogator 102 may be completely halted. This non-operational state may be useful, for instance, in situations where it is desirable to render the RFID tag 110 unresponsive to an RFID interrogation signal. For example, as noted above, when no toll is due on a toll road due to the number of passengers in the car, it may be desirable for the RFID tag 110 to be unresponsive to an RFID interrogation issued by a toll road portal system.
In some embodiments, a mechanism is provided for selectively altering the relative position of RF module 220 and the booster antenna 210 . Advantageously, this allows a user to selectively displace the RF module 220 from an optimized position over the booster antenna 210 rendering it unresponsive or detuned such that it will not respond at a sufficient measurement or perform adequately. Thus, for example, when taking a toll road that is free for car-pools, a user can manipulate the mechanism in order to effectively deactivate the RFID tag 110 and avoid paying the toll. In various embodiments, the mechanism may include a switch, lever, knob, slider, rotatable member, or any other device or construction which serves this purpose.
A selectively-activatable RFID tag 110 is depicted in FIG. 2C . The RFID tag 110 may comprise a slider mechanism 240 and an indicator area 250 , where the RF module 220 is mechanically coupled to the slider 240 . By manipulating the slider, a user modifies the relative positions of the RF module 220 and the booster antenna 210 . The indicator area 250 may provide a visual indication of the status of the RFID tag 110 . For example, if the RF module 220 and booster antenna 210 are positioned for effective transfer of RF power, the indicator area 250 may present a first visual indication such as a green color. Conversely, if the RF module 220 and booster antenna 210 are not positioned for effective transfer of RF power, the indicator area may provide a second visual indication such as a red color. In this manner, one or more individuals can be alerted of the effective operability of the RFID tag 110 .
FIG. 3 is a block diagram illustrating an exemplary RFID switch tag including two RF modules and a single booster antenna according to one embodiment of the present invention. As shown, a single booster antenna 310 is provided. However, in this embodiment two RF modules 322 and 324 are shown. The booster antenna 310 and RF modules 322 and 324 may be positioned such that only one of the two modules 322 and 324 is effectively coupled to the booster antenna 310 at any one time. For example, as shown in FIG. 3 , RF module 322 is coupled to the booster antenna 310 while RF module 324 is shielded. Thus, RF module 322 is effectively tuned and responsive, while RF module 324 is effectively detuned and unresponsive.
A mechanism (e.g., switch, slider, knob, lever, rotatable member, etc.) such as the slider 240 depicted in FIG. 2C may be provided for selectively altering the relative position of RF module 322 and 324 and the booster antenna 310 . In this manner, the positioning altering mechanism can be manipulated to selectively cause zero or one of the two modules 322 and 324 to be coupled to the antenna 310 . For example, in a first state, only module 322 may be coupled with the booster antenna 310 . In a second state, only module 324 may be coupled with booster antenna 310 . In a third state, neither modules 322 or 324 are coupled with the booster antenna 310 .
Advantageously, this arrangement allows a single RFID tag 110 to be used for multiple services. For example, one RF module, e.g. module 322 , can be associated with toll road portal system. The other RF module, e.g., module 324 , can be associated with a system for tracking car-pool lane use. The user can manipulate the position altering mechanism in order to couple the booster antenna 310 to the RF module 322 or 324 that is appropriate for current usage. In some embodiments, one or more visuals indicators may also be provided to indicate which RF module 322 or 324 is currently coupled to the booster antenna. Note also that while only two RF modules 322 and 324 are depicted in FIG. 3 , any number of RF modules may be used in accordance with embodiments of the present invention.
In the embodiment of FIG. 3 , the RF modules 322 and 324 may be aligned horizontally and the direction of movement caused by manipulation of the position altering mechanism may likewise be horizontal. In other embodiments, however, the RF modules 322 and 324 may be aligned vertically and the direction of movement may be vertical. In still other embodiments, the RF modules 322 , 324 may be arranged in an arcuate manner and the direction of motion may also be arcuate. Various other arrangements of the RF modules 322 and 324 , the booster antenna 310 , and the direction of movement are also possible according to embodiments of the present invention.
FIG. 4 is a block diagram illustrating an exemplary RFID switch tag including two RF modules and two corresponding booster antennas according to one embodiment of the present invention. As shown by the figure, two booster antennas 412 and 414 and two RF modules 422 and 424 are provided. In some embodiments, each RF module 422 and 424 may be associated with a different RFID service such that a user may independently tune each pair of RF modules 422 and 424 and booster antennas 412 and 414 present within the RFID tag 110 . Note that while only two pairs of RF modules 422 and 424 and booster antennas 412 and 414 are depicted in FIG. 4 , any number of RF module/booster antenna pairs may be utilized according to embodiments of the present invention.
While the embodiment depicted in FIG. 4 depicts the antennas 412 and 414 as bearing similar physical properties (such as size and shape), each booster antenna 412 and 414 may have differing physical properties according to alternative embodiments. These differences may result in different properties for gathering RF energies. In some embodiments, the antennas 412 and 414 may be specifically tuned to different frequencies.
According to some embodiments, each of the RF modules 422 and 424 may be attached to single position altering mechanism (not shown). In this manner, a user can manipulate the mechanism such that only one of the two RF modules 422 and 424 is coupled to its respective boost antenna 412 or 414 at any one time. A visual indicator may be provided to indicate which RF module 422 or 424 is currently coupled to its respective booster antenna 412 and 414 . In some embodiments, the position altering mechanism may be manipulated such that both or neither of the RF modules 422 or 424 are coupled to the respective boost antennas 412 or 414 at the same time.
In other embodiments, each of the RF modules 422 and 424 may be attached to a separate position altering mechanism (not shown). According to these embodiments, both, neither, or only one of the RF modules 422 or 424 may be coupled to the respective boost antennas 412 and 414 at the same time. The visual indicator may display a first color if the first RF module 422 is active and a second color if the second RF module 424 is active.
Note that in the embodiment depicted in FIG. 4 , the booster antennas 412 and 414 may be arranged along a vertical axis, and a horizontal direction of motion is utilized via manipulation of the position altering mechanism. However, persons skilled in the art will appreciate that the booster antennas 412 and 414 may be arranged horizontally, vertically, along an arc, in different planes, or in various other manners. Additionally, the direction of motion may switch the RF modules 422 and 424 between coupled and uncoupled positions for the respective booster antennas 412 and 414 .
FIG. 5 is a block diagram illustrating an exemplary RFID switch tag including a single RF module and two booster antennas that are tuned to different frequencies according to one embodiment of the present invention. As shown, a single RF module 520 may be provided, along with two booster antennas 512 and 514 . The booster antennas 512 and 514 may be configured with different physical properties to enable the RF module 520 to switch between separate RFID services. In this respect, the RF module 520 may be mechanically coupled to a position altering mechanism such that the tag can be switched to select one or none of the booster antennas 512 and 514 . A visual indicator may display a first color if the first booster antenna 512 corresponding to a first RFID service is selected and a second color if the second booster antenna 514 corresponding to a second RFID service is selected.
As in the case of FIG. 4 , the booster antennas 512 and 514 may be arranged along a vertical axis and the direction of motion of the RF module 520 caused by manipulation of the position altering mechanism is vertical. In other embodiments, the booster antennas 512 and 514 may be arranged horizontally, along an arc, in different planes, or in another manner and the direction of motion is adapted to switch the RF module 520 between the booster antennas 512 and 514 .
FIGS. 6A-10 generally depict various embodiments of RFID switch tags which may be utilized, for example, within an automobile setting. Each of the RFID switch tags may be affixed, fastened, or adhered to a windshield, rearview mirror, automobile exterior, or to various other areas of the automobile according to embodiments of the present invention.
FIG. 6A is a front-side view of an exemplary switch-activated RFID tag according to one embodiment of the present invention, while FIG. 6B is a perspective view of the back side of the exemplary switch-activated RFID tag according to the embodiment depicted in FIG. 6A . As shown by the figure, the RFID tag may include a slider configuration 602 with a window 604 on the outside and one or more icon graphics 606 on the opposite side. In some embodiments, an optional mounting component (not shown) may be used to adhere, fasten, or clip the RFID tag to a visor, for example.
FIG. 7A is a back-side view of an exemplary circular-shaped and rotatable RFID switch tag in a first position according to one embodiment of the present invention, FIG. 7B is a back-side view of the exemplary circular-shaped and rotatable RFID switch tag in a second position according to the embodiment depicted in FIG. 7A , while FIG. 7C is a front-side view of the exemplary circular-shaped and rotatable RFID switch tag depicted in FIGS. 7A and 7B . As depicted in FIGS. 7A and 7B , a circular shaped member 702 may be rotated, for example, clockwise or counterclockwise, in order to activate or deactivate the RFID switch tag. Icon graphics 706 on the back-side may be used to inform one or more individuals of the activation state of the RFID switch tag. Optionally, a window 704 on the opposite side of the RFID switch tag (see FIG. 7C ) may be used to reveal the activation state of the RFID switch tag to the outside.
FIG. 8A is a perspective view of the back side of an exemplary triangular-shaped and rotatable RFID switch tag in a first position according to one embodiment of the present invention, FIG. 8B is a back-side view of the exemplary triangular-shaped and rotatable RFID switch tag in a second position according to the embodiment depicted in FIG. 8A , while FIG. 8C is a front-side of the exemplary triangular-shaped and rotatable RFID switch tag depicted in FIGS. 8A and 8B . FIGS. 8A-8C may operate similar to FIG. 7A-7C , but utilize a substantially triangular shape and design rather than a circular one. Various other shapes and designs may also be utilized in accordance with embodiments of the present invention.
FIG. 9A is a perspective view of the back side of an exemplary switch-activated RFID tag according to one embodiment of the present invention, while FIG. 9B is a front-side view of the exemplary switch-activated RFID tag depicted in FIG. 9A . As depicted in FIG. 9A , the RFID tag may utilize a slider configuration 902 with a windows on both sides 904 and 905 of the RFID tag. Such an RFID tag may be adhered to the window of the automobile or may also use a cradle system for mobility according to various embodiments.
FIG. 10 is a perspective view of a separate exemplary slide-activated RFID tag according to one embodiment of the present invention. According to some embodiments, no physical switch or level is utilized. Instead, the RFID tag may be activated or deactivated by manually sliding a first substrate 1002 to or from a casing 1004 .
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments. Where this document refers to technologies that would be apparent or known to one of ordinary skill in the art, such technologies encompass those apparent or known to the skilled artisan now or at any time in the future. In addition, the invention is not restricted to the illustrated example architectures or configurations, but the desired features can be implemented using a variety of alternative architectures and configurations. As will become apparent to one of ordinary skill in the art after reading this document, the illustrated embodiments and their various alternatives can be implemented without confinement to the illustrated example. One of ordinary skill in the art would also understand how alternative functional, logical or physical partitioning and configurations could be utilized to implement the desired features of the present invention.
Furthermore, although items, elements or components of the invention may be described or claimed in the singular, the plural is contemplated to be within the scope thereof unless limitation to the singular is explicitly stated. The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent. | Various embodiments of RFID switch devices are disclosed herein. Such RFID switch devices advantageously enable manual activation/deactivation of the RF module. The RFID switch device may include a RF module with an integrated circuit adapted to ohmically connect to a substantially coplanar conductive trace pattern, as well as booster antenna for extending the operational range of the RFID device. The operational range of the RFID switch device may be extended when a region of the booster antenna overlaps a region of the conductive trace pattern on the RF module via inductive or capacitive coupling. The RFID switch device may further include a visual indicator displaying a first color if the RFID switch device is in an active state and/or a second color if the RFID switch device is in an inactive state. | 6 |
SUMMARY OF INVENTION
Accordingly it is the object of the present invention to provide a fish net assembly with means applicable to existing as well as new nets whereby it may be stored when not in use with a minimum amount of exposure to view so that the aesthetic appearance of the aquarium is not destroyed.
It is therefore an object of this invention to provide a suspension bracket for a fish net whereby it may be suspended from the rim of the aquarium tank and may be disposed behind the rear wall of the tank so as to obscure it from view.
Another object of this invention is to provide a fish net assembly wherein the suspension bracket means may be readily attached to a fish net and removed therefrom as desired.
A still further object of this invention is to provide a fish net assembly with a suspension bracket which is capable of being disposed at any desired elevation along the length of the manipulating wand thereof so that it may be readily moved to a position in which it will not interfere with the manipulation of the net or its packaging or storage.
Another object of this invention is to provide a fish net assembly wherein the possibility of loss of the suspension bracket by accident or pilferage during exposure for sale is minimized.
BACKGROUND OF INVENTION
This invention relates to a fish net assembly and packaging therefore and more particularly to a fish net assembly wherein means are provided for conveniently and efficiently storing the fish net during periods of non-use as well as packaging means therefore adapted to economically and conveniently package the assembly in a pilfer proof manner.
Fish nets are utilized in the aquarium hobby for removing and transporting fish from and to an aquarium tank, as desired. Such nets since they are immersed in water when in use, are inconvenient to carry from place to place for storage and are therefore usually stored adjacent to the aquarium tank so as to be readily available for use when desired.
Customarily the fish net is placed on top of the tank as when a tank cover is provided. In such circumstances the net is exposed to view and in many respects tends to detract from the aesthetic appearance of the aquarium. Similar problems are presented when a net is stored on shelves or the like adjacent to the aquarium stand.
Such nets are usually formed of wire and essentially constitute a wire frame provided with extended portions which are twisted together to form a manipulating wand so that it may be dipped into the aquarium tank and manipulated there to capture a fish.
The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results which will be evident to those skilled in the tropical fish aquarium art in the light of this disclosure, may be achieved with the exemplary embodiment of the invention described in detail hereinafter and illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a packaged aquarium net assembly in accordance with the present invention.
FIG. 2 is a perspective view of the suspension bracket in accordance with the present invention, shown on enlarged scale.
FIG. 3 is a side elevational view of an aquarium net assembly removed from its packaging enclosure shown in stored position on an aquarium tank with the netting sack extended.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As is shown in FIG. 1, the invention comprises an aquarium fish net assembly designated generally by the numeral 10 which carries a suspension bracket member as more particularly shown in FIG. 2 and designated generally by the numeral 12, the assembly is adapted to be enclosed in packaging enclosure designated generally by the numeral 14 for transportation and sales display.
The fish net assembly 10 comprises a fish net which may be of conventional form and is comprised of a plastic coated wire frame 16 preferably of rectangular configuration which is provided with an integrally formed elongated twisted wire wand 17 extending therefrom. The wand 17 terminates in a hand grip 20 in the form of a loop. The wire utilized for the formation of the net is coated with a plastic or elastomeric material such as for example a polyvinyl-chloride which in addition to preventing corrosion of the steel wire, from which the frame is usually formed, provides a cushioning or somewhat compressible surface layer therefore. The looped hand grip is also desirably enclosed in an additional tube of similar plastic material to provide a more effective and convenient hand grip therefore.
An open mouth sack of formaminous material or netting 18 preferably formed of a synthetic resin fabric such as nylon or polyethelene is secured by suitable means, such as by stitching along about the perimeter of the rectangular frame 16. The meeting terminal portions of the wire along one side of the frame are twisted together to form the wand 17 which terminates in the hand grip 20.
The aquarium fish net assembly is further provided with a suspension bracket 12 for supporting the same in a suspended position as more particularly illustrated in FIG. 2. Said suspension bracket is in the form of a generally "C" shaped sleeve 22 comprised of a cylinder having an axially extending interruption or split 24 separating the wall thereof and extending from rim to rim of the sleeve as shown at 24. An arm 26 extends outwardly from the upper rim of the sleeve wall in diametric opposition to the split. The terminal end of the arm remote from the sleeve is provided with a depending lip 28. The sleeve is dimensioned so that it will encompass at least a major portion of the circumference of the twisted wire handle. It is formed of a plastic material having sufficient flexibility and resilience to permit the split to be temporarily enlarged so that the sleeve may be snapped into position about the twisted wire handle and to frictionally grip the same. The frictional engagement is sufficient to maintain the suspension bracket at any selected elevation and radial angular position. The suspension bracket is nevertheless capable of being slid along and rotated about the wand as desired by the user. The compressibility of the wire coating facilitates the sliding movement of the suspension bracket as well as its retention in a fixed position. By the same token, the suspension bracket may be rotated about the axis of the twisted wire wand and will be retained against displacement in any desired radial position. The suspension bracket is advantageously integrally formed by injection molding of a plastic material.
It will be apparent from the foregoing that the arrangement provides an aquarium fish net assembly with a suspension bracket which may be snapped onto and removed from the net and is capable of being frictionally maintained in position on the handle of the net. The suspension bracket may be manually moved along or about the handle of the net and manually relocated to any other desired position.
The net may readily be stored when not in use by merely rotating the suspension bracket so that it occupies a position projecting outwardly from the plane of the net frame and the arm may thus rest upon the upper rim of an aquarium tank in the manner indicated in FIG. 3 to suspend the net therefrom. The suspension bracket arm may be positioned at any desired elevation along the handle of the net so that only so much of the upper portion of the handle is visible above the aquarium rim as is desired. The fish net may thus be stored unobstrusively suspended from the tank rim and avoids an unsightly appearance. The net will nevertheless be available for immediate use.
It will be noted that in use for trapping fish it is undesirable to have an element protruding from the plane of the net frame since such projection causes interference. This is particularly true when it is desired to bring the face of the net into close proximity or contact with aquarium wall to thus prevent the escape of the fish. By rotating the suspension bracket so that the arm is positioned in alignment with the plane of the net frame it may be used without interference therefrom. The snagging of the net with aquarium plants and accessories is also prevented.
In packaging and marketing an item of this type significant problems are encountered. Since the suspension bracket is separable from the wand, any exposure of the arm beyond the packaging enclosure permits removal or loss of the support arm by accident or by deliberate pilferage. Furthermore any projection of the arm from the package may cause it to be snagged with others and requires additional packaging space. To completely enclose the entire net assembly in a package would involve additional expense as well as packaging space as would be the case if the entire assembly were to be enclosed in a transparent plastic bubble on a card. The foregoing arrangement of the assembly permits the elimination of these possibilities and minimizes packaging cost and space while at the same time providing a desirable arrangement for visible display purposes at the point of sale.
In order to overcome the foregoing disadvantages, the net portion of the fish net assembly comprising the frame and netting mounted thereon as well as the suspension bracket is enclosed in transparent plastic bag 30. The wand is permitted to extend from the upper edge of the bag. The bag is formed of two layers of a transparent heat sealable plastic film suitably joined as by heat sealing along three of its sides as indicated at 30a, 30b and 30c. The bag is dimensioned so that the upper edge thereof extends above the net frame for the distance necessary to enclose the suspension bracket when located at its lowermost position as shown in FIG. 1 leaving a sufficient margin above the bracket to accommodate a heat seal. The seal is formed along the top edge of the bag as shown at 34. For this purpose the suspension bracket 12 is rotated about the wand to a position wherein it extends parallel to the plane of the frame and is in alignment therewith. The frame and bracket portion of the net is disposed within and the layers of bag material are joined to form the upper edge closure for the bag. This is advantageously accomplished by heat sealing the layers to each other as indicated at 34. It will be noted that the heat seal is interrupted at as indicated at 32, to accommodate and permit the projection of the wand through the opening thus formed.
By reason of the foregoing arrangement a relatively flat package is provided for the net assembly. The package occupies a minimum amount of package space and yet permits the item to be suitably displayed at the point of sale. The package further permits the suspension bracket to be enclosed within the bag so as to prevent accidental displacement or loss as well as to prevent the pilferage of the suspension bracket which would otherwise be readily removeable. It should also be noted that the projecting wand permits the packaged item to be hung on a display rack by means of the hand grip loop thus eliminating the requirement of a perforated stiffening attachment so as a "header" for the plastic bag as would otherwise be the case.
It will be seen from the foregoing that there has been provided an aquarium fish net assembly which may be readily and efficiently utilized and conveniently and unobstrusively stored when not in use. The arrangement further provides an economical packaging arrangement which eliminates the possibility of accidental loss or pilferage of a readily separable element of the assembly and minimizes packaging bulk.
Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and is not to be construed as a limitation of the invention. | An aquarium net assembly comprising an aquarium net including a frame mounted netting sack and an elongated wand extending from said frame, a suspension bracket mounted on said wand for movement along the longitudinal axis of said wand for rotation about the axis said suspension bracket, comprising a sleeve frictionally engaged about said wand and an arm extending from said sleeve, said arm terminating in a downwardly extending lip in combination with a flat bag-like enclosure for said assembly within which said frame mounted net and said bracket is received, said bracket being disposed adjacent to the frame and having its arm in alignment with the plane of the frame thus constituting a flat packaged fish net assembly. | 0 |
FIELD OF THE INVENTION
The present invention relates to soap formulations, particularly liquid soap formulations, with high concentration of soap. Using formulation and processing criticalities, applicants have found a way in which these high concentration soaps can be readily dispensed (have correct rheology) from, for example, tube, bottle, pump or such dispensers.
BACKGROUND OF THE INVENTION
The rapid growth in human population and the changing economic environment are placing ever increasing demand on world water supplies. Because of water scarcity over much of the world, for example, it is important to prepare liquid cleansing products with as little water as possible. Low water cleansing products offer an environmentally friendly cleansing route which lowers strain on water supply. In the current invention, applicants have provided precisely such low water (high soap) cleansers, which are formed by replacing water with a dense liquid crystalline surfactant phase. Quite unpredictably, these formulations are formulated in a manner that, despite being concentrated products, they can be readily dispensed by hand by the end user consumer.
High concentration soap formulations (i.e., formulations in which fatty acid soap comprises >50%, preferably >50 to 80%, more preferably 55 to 80% by wt. and, more preferably, 60 to 80% by wt. of the formulation) typically have a solid or thick gel-like rheology at room temperature. Because of this rheology, such formulations are difficult to pump while in production and are extremely difficult to use as personal cleansers dispensed from a tube, bottle, pump or tottle.
While not wishing to be bound by theory, it is believed that the thick rheology associated with high concentration liquid soap composition is the result of the large amount of hexagonal and solid surfactant phases present in the soap at high concentration.
Unpredictably, applicants have found that if the ratio of free fatty acid to soap (e.g., percent of neutralized soap) in these concentrated soap/free fatty acid liquid soap formulations (e.g., percent of soap neutralized) is maintained within defined critical ranges; and, further, that if (1) concentrations or percentage of soap with specifically defined preferred counterion; (2) preferred percentage of saturation versus unsaturation of fatty acid soap and free fatty acid chain lengths; (3) chain length distribution of fatty acid soap and free fatty acid; (4) amount synthetic surfactant (if any); and (5) concentration of solvent (e.g., water, alkylene, glycol) are all selected and maintained within critically defined parameters, then the amount or degree of hexagonal and solid surfactant phase formation can be controlled such that a highly concentrated liquid soap can be made which has a pumpable viscosity (as specifically defined below). If these parameters are not carefully maintained, on the other hand, the viscosities quickly rise and formulations become difficult or impossible to pump (again, outside of ranges defined by the invention).
It should be noted that when we speak of “pumpable” or “flowable” viscosity, this is a rheological property which can be critical at many different stages in the manufacturing or distribution process. Thus, it can be critical to keep pumpable viscosity for example in the mixing stage of a manufacturing tank; in filing and/or discharging fluid to manufacturing or storage tanks; and/or in filling product into final packaging.
One great benefit of this invention is that the liquids made by this specific selected blend of neutralized soap and unneutralized fatty acids can be made in what would normally be used as a bar production facility. Unexpectedly, and unpredictably, applicants have found that the blends of fatty acid and soap used in the bar production process can be used to produce concentrated liquids as well (i.e., assuming the criticalities noted above are maintained).
In addition, concentrated liquids having the correct rheology and which are produced by the process of the invention can be sold as a “concentrated liquid product” whereby the consumer can be instructed to dilute the product at home (resulting in both environmentally friendly packaging and tremendous cost savings); or the concentrated liquid can be transported to a different place and later diluted as part of the production process. In the latter case, this allows the producer to produce more cheaply than when normally making liquid soap/syndet composition (e.g., reduction in transportation costs due to use of concentrates rather than transporting heavy water-containing product). As indicated above, tremendous efficiencies between bars and liquids are also found because any excess capacity from bar manufacturing sites may be used to make liquids.
The key, as noted above, is to obtain a final concentrated liquid formulation in which variables such as (1) ratio of neutralized soap to unneutralized fatty acid; (2) counterion; (3) chain length of fatty acid soaps and free fatty acids; (4) synthetic surfactant, if any; (5) and solvent are critically controlled to obtain viscosities below a defined level and defined by a dispensing force needed to dispense the product. This goal in turn may be achieved either by controlled neutralization of fatty acid; or by using mixtures of free fatty acid and fully neutralized soap such that resulting formulation falls within defined formulation parameters where this defined pumpable or squeezable rheology is obtained.
It should be noted that there is interplay between variables and these variables can be adjusted as long as the overall goal of maintaining a low dispensing force is maintained. Thus, for example, the degree of neutralization or exact percent of long chain or low chain length soap/fatty acids may be closer to the upper or lower ranges in which case adjustments can be made to solvent level or level or synthetic surfactant.
In one embodiment of the invention, for example, there may be present only soap/fatty acid and neutralizing solvent such as potassium hydroxide (e.g., no viscosity reducing co-solvent such as dipropylene glycol, propylene glycol). Such embodiment would minimize the level of long chain length, fatty acid/soaps (which tend to increase viscosity) and certainly ensure their level is within defined ranges. In another embodiment of the invention, the concentrate could tolerate higher levels of longer chain length soaps/fatty acids but would also have some required level of synthetic surfactant and/or viscosity reducing co-solvent to ensure the dispensing force is within defined parameters. This second embodiment is specifically claimed in a co-pending application filed on the same date by applicants.
As far as applicants are aware, the art does not disclose the specific parameters required to obtain concentrated soap liquids of the invention, or a method of obtaining these liquids such that the liquid soap has a pumpable, readily pourable rheology, i.e., measured by dispensing force which is defined in the protocol. Specifically, there is nothing in the art which would teach or suggest the person of ordinary skill either that this is a problem or how to begin to solve such problem.
GB 699 189 is an example of references disclosing compositions made by neutralization of fatty acids with caustic potash. Although the fatty acids of the resulting liquid cleansers are neutralized, there is no indication of partial neutralization, or of the resulting critical, specific ratios, of fatty acid to soap. Further, there is no disclosure that such specific ratios, or of any of the other criticalities of saturation, chain length, etc. which are required to obtain the pumpable (e.g., squeezable), concentrated soap liquids of the invention having defined viscosity. This reference is typical of many older references from before 1960.
More recent references include those which use soap at much lower levels. Examples of such references include WO 95/13355, WO 05/18760 and WO 97/27279.
U.S. Pat. Nos. 5,952,286 and 6,077,816, both to Puwada, relate to the use of free fatty acid to form lamellar structures in liquid cleansing products having 9 to 50% surfactant concentration. Overall concentrations of surfactant in these references are lower than the overall concentration of surfactant (e.g., soap plus fatty acid) of the compositions of the invention and the concentrations of water are higher than those of our invention. Further, there is no recognition of use of specific ratios of fatty acid to soap or of other criticalities noted.
U.S. Pat. No. 7,351,749 to Divone et al. relates to the process for manufacture of personal care products using concentrated water phase. The reference is not related to concentrated soaps or to specific ratios of fatty acid to the soap.
U.S. Pat. Nos. 5,296,158 and 5,149,574 to MacGilp disclose compositions with potassium soap and free fatty acid. Concentrations of water are 55-90% compared to top solvent concentration (water/solvent) of 40% in our invention. U.S. Pat. No. 4,310,433 to Stiros discloses mixtures of neutralized and unneutralized fatty acids where fatty acids are mixtures of saturated and unsaturated. The compositions again comprise 50-95% water, levels of solvent well above those of our invention. Various other references to MacGilp, (U.S. Pat. No. 5,158,699; U.S. Pat. No. 5,296,157) also have much higher levels of water/overall solvent.
U.S. Pat. No. 5,308,526 to Dias discloses composition with K + soap and free fatty acids. They comprise 35-70% water. The compositions have much less than 50% soap.
WO 2004/080431 to Unilever relates to method of preparing personal care compositions from concentrate. There appears to be no recognition of a concentrate having critically specific levels of neutralization (ratio of fatty acid to soap) or other noted variables which provide a rheology allowing concentrated soap formulations to be pumped or readily dispensed. The reference also fails to disclose a separate concentrated liquid (e.g., as separate stand alone product) which can be sold to consumers for possible dilution at home.
GB 2005297 (Unilever) discloses liquid soap compositions comprising potassium soap, 0-20% glycerol, 5-20% alkylene glycol, 0-10% free fatty acids and 20-50% water. Levels of soap are well below the 50% level of the subject invention.
GB1427341 (Unilever) discloses potassium soap crystals in aqueous glycerin solution comprising 12-40% glycerol and 20-50% H 2 O. Again, levels of soap are well below those of compositions of the invention.
JP 2006/282,591 and JP 2002/226,359 relate to face wash creams. Neither appears to disclose criticality of fatty acid to soap in combination with other criticalities to yield a high concentrated, pumpable liquid soap.
None of the reference discloses high soap (>50% by wt.) compositions having a critical ratio of fatty acid to soap or combination with criticalities of saturation, chain length, solvent etc. to produce pumpable, concentrated liquid soaps. There also is no reference relating to sale of such specific compositions as stand alone concentrates with instructions for home dilution.
BRIEF DESCRIPTION OF THE INVENTION
Unexpectedly, and quite unpredictably, applicants have now found that, if the ratio of unneutralized fatty acid to neutralized fatty acid soap (in a concentrate solution where soap comprises >50%, preferably ≧60% of concentrate) is kept within a specific critical window, in combination with other critical parameters noted below, the resulting concentrate will have a rheology that allows it to be pumped and/or dispensed. Such pumpability is defined as a formulation which can be dispensed by a force of less than 300N at steady state when measured at temperature of 23° C. Measurement can also be made at 12° C. although, for purposes of the measurement definition, the temperature is preferably 23° C. Measurement details are defined in more detail in the protocol below. It should be noted that, although it is probably not possible for humans, unassisted by technology, to generate a force of 300N, tubes of varying orifice size can be designed which allow for dispensing of fluid at values closer to the upper ranges of Newton force required by the protocol.
In one embodiment, the invention relates to a concentrated soap formulation, which, optionally, can be moved (as an intermediate for preparation of final product at same or other site); or which is sold as a “final” product (e.g., to be diluted by consumer elsewhere). In a second embodiment, the invention relates to a packaged product containing said concentrated solution. Finally, in a third embodiment, the invention relates to a process for preparing concentrated liquids which process comprises either (a) neutralizing soap stock comprising oils, triglycerides and fatty acids to provide soap and obtain required parameters (e.g., ratio of fatty acid to neutralized soap); or (b) mixing already neutralized soap and free fatty acid to form mixture having desired criteria.
In one compositional embodiment of the invention (subject of the present application), the present application comprises concentrated soap formulation and does not necessarily comprise synthetic and/or co-solvent (other than water and/or neutralizing hydroxide solution). This embodiment comprises:
(a) >50% by wt. fatty acid soap, preferably >50 to 80%, more preferably 55 to 80%, even more preferably 60 to 80% fatty acid soap; (b) free fatty acid at concentration such that soap to free fatty acid ratio is about 2:1 to 20:1 on a weight basis, preferably 2.5:1 to 12:1. Typically ratio of 2.5:1 to 12:1 reflects a neutralization (if soap is formed in-situ versus combining fatty acid and already pre-formed soap) of about 60 to about 90% neutralization; (c) 0% to 30%, preferably 1% to 20% by wt., more preferably 1% to 15% by wt. (even more preferably 10% by wt. or below) of synthetic non-soap surfactant (e.g., used to help reduce viscosity to defined “pumpable” goal), wherein said synthetic, if used, comprises at least one anionic surfactant and, more preferably, comprises a combination of anionic and amphoteric surfactant wherein anionic comprise more than half of such mixture; although synthetic, if present, helps serve as a viscosity modifier, if short chain soap and fatty acid definitely comprise ≧50% of total, then the synthetic and/or co-solvent (other than water) are not absolutely required; and (d) 10-40% by wt. solvent wherein solvent includes combination of water and/or co-solvents preferably selected from alkylene glycols (e.g., propylene glycol, dipropylene glycol, mixtures, etc.); as noted, where short chain soap and fatty acid comprise ≧50%, then co-solvent (other than water) is not required so, preferably, the 10-40% solvent comprises only water;
wherein the soap counterion is preferably potassium and/or amine based counterion (e.g., sodium counterions can be used, but tend to increase viscosity);
wherein soap and fatty acid chains may be a mix of saturated and unsaturated, but are preferably >75%, more preferably 80% to 100%, even more preferably 96% to 100% and even more preferably 100% saturated;
wherein soap and fatty acid comprise a mixture of long (>C 14 -C 30 ) and short (≦C 14 ) chain and preferably comprise ≧50%; more preferably >60%, even more preferably >75% short chain (as indicated above, where short chain is definitely ≧50%, synthetic and/or co-solvents are not required, although of course small amounts, e.g., less than 5% by wt., preferably less than 3%, more preferably less than 1% of one or both may be used);
and wherein the “pumpable” viscosity achieved by maintaining ratio of soap to fatty acid (e.g., through neutralization) and maintaining other noted variable within defined parameters is defined as a dispensing force of less than 300 Newtons (N) measured at steady state and at a temperature of 23° or 12° C. as defined in the protocol.
In a second compositional embodiment of the invention (subject of co-pending application filed same date), the invention comprises concentrated soap formulation where short chain fatty acid and soap (≦C 14 ) is less than 50% total fatty acids and soap. Long chain (>C 14 ) may comprise >50% to 80%, or possibly even more. In this embodiment, viscosity modifier such as some synthetic and/or co-solvent is required to ensure pumpable viscosity as defined in the protocol.
More specifically, this embodiment comprises:
(a) >50% by wt., preferably >50% to 80%, more preferably 55% to 80% and even more preferably 60% to 80% fatty acid soap; (b) free fatty acid in the same ratio as defined for the first compositional embodiment; (c) 0% to 30%, preferably 1% to 20%, more preferably 1% to 15%, even more preferably 5% to 15% synthetic, preferably comprising at least one anionic; and (d) 10% to 40% solvent which preferably will comprise 1% to 15% solvent other than water;
wherein at least 1% to 10%, preferably at least 2 to 10% by wt. of total (c) and/or solvent other than water in (d) (i.e., there must be present at least 1% synthetic surfactant and/or solvent other than water) must be present and where such other solvent is preferably an alkylene glycol;
wherein counterion and level of saturation are as defined for first compositional embodiment;
wherein long chain soap (>C 14 ) comprises >50% to 80% of fatty acid/soap chain length; and
wherein pumpable viscosity combined is defined as a dispensing force of less than 300 Newton (N) at steady state as defined in protocol.
In another embodiment, the invention provides a packaged personal care/personal wash product which comprises:
(a) a container or bottle comprising a label or advertising intended for sale or distribution to consumers; and (b) concentrated soap formulation as defined in the compositional embodiments of the invention.
In this embodiment, the container or a package in which the container is held may contain instructions to the consumer as to how and when to dilute the concentrated product for ultimate use.
In yet another embodiment, the invention comprises a process for preparing a concentrated soap liquid according to either compositional embodiment which process comprises:
(a) reacting a soap stock comprising oils, triglycerides, fatty acids and mixtures thereof with a neutralizing solution, preferably a caustic solution such as KOH, to obtain composition where ratio of soap to free fatty acid is between 2:1 to 20:1, preferably 2.5:1 to 12:1 on weight basis (generally corresponding to level of 60-90% neutralization), and subsequently or simultaneously combining soap stock and neutralizing solution with 0% to 20% synthetic surfactant, and 10% to 40% solvent; or (b) mixing already neutralized soap and free fatty acid to form mixture having ratios and/or neutralization levels noted above and subsequently combining with same levels of synthetic surfactant, and solvent also noted.
These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Other than in the experimental example, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein are to be understood as modified in all instances by the term “about”. Similarly, all percentages are weight/weight percentages of the total composition unless otherwise indicated. Numerical ranges expressed in the format “from x to y” are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format “from x to y” it is understood that all ranges combining the different endpoints are also contemplated. Further in specifying the range of concentration, it is noted that any particular upper concentration can be associated with any particular lower concentration. Where the term “comprising” is used in the specification or claims, it is not intended to exclude any terms, steps or features not specifically recited. For the avoidance of doubt, the word “comprising” is intended to mean “including” but not necessarily “consisting of” or “composed of”. In other words, the listed steps, options, or alternatives need not be exhaustive. All temperatures are in degrees Celsius (° C.) unless specific otherwise. All measurements are in SI units unless specified otherwise. All documents cited are—in relevant part—incorporated herein by reference.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to liquid soap formulations with highly concentrated amounts of soap, yet which maintain a viscosity/rheology suitable for these concentrated soaps to be pumped from a reservoir, container or bottle, as defined by formulations which can be dispensed by a dispensing force less than 300N at steady state measured at 23° C. and defined using protocol below. Unexpectedly, applicants have found that, only when the ratio of neutralized soap to unneutralized free fatty acid is maintained within strict, critically defined limits, and parameters such as counterion, saturation, chain length of fatty acids and soap; solvent and/or synthetic surfactant levels etc. are controlled, only then is it possible to obtain such concentrated soap formulations (i.e., >50% soap) which maintain the characteristics of a suitable pumpable liquid (defined by a dispensing force as noted).
In a compositional embodiment, the invention is directed to the concentrated liquid formulations themselves. Those compositions are defined by ratios of neutralized soap to fatty acid (which also correspond to levels of neutralization) where the critical rheology is obtained. The formulations can be obtained by controlled neutralization and/or by mixing fatty acids and soap to fall within the critically defined parameters. One aspect of the compositional invention is directed to compositions where preferably ≧50% of soap/fatty acid have chain length ≦C 14 and wherein use of synthetic surfactant and/or certain co-solvents is not required, and a second aspect (claimed in co-pending application) is directed to composition having >50% chain length >C 14 and where a minimum level of synthetic and/or co-solvent (e.g., alkylene glycol) is required.
In a second embodiment, the invention is defined by a packaged consumer product which comprises the packaged bottle or container comprising the concentrated formulation of the first compositional embodiment. Preferably, the label provides instructions to consumers on how to add water to effectively use the concentrates.
In a third embodiment, the invention comprises a process for preparing these unique concentrated soap liquids which process essentially comprises controlling the neutralization process and/or reactants to ensure the final product has the criticality defined ratios which will ensure the unpredictable pumpable rheology.
The invention is described in greater detail below.
The composition of the invention comprises as noted, >50% by wt. fatty acid soap, preferably >50% to 80% by wt., more preferably 55% to 80%, even more preferably 60 to 80% fatty acid soap.
In addition, compositions of the invention comprise free fatty acid and indeed, it is the ratio of free fatty acid to soap which helps define (along with other variables discussed below) the rheology which is required for “pumpability”.
More specifically, the concentration of free fatty acid to soap (obtained either by controlled neutralization or by simple mixing) is such that ratio of soap to free fatty acid is about 2:1 to 20:1, preferably 2.5:1 to 12:1. This latter ratio typically reflects a neutralization (if formed in-situ) of about 60 to 90% neutralization.
Further the counterion on soap; the degree of saturation or unsaturation; chain length distribution in soap and/or fatty acid, and levels of synthetic and/or solvent can be critical in determining final rheology (e.g., what dispensing force is required for pumping or dispensing). As indicated, depending in particular on chain length distribution, the levels of synthetic and/or solvent can also be critical in obtaining the right feeling.
Although any salt counterion can be used, preferably the counterion for the soap is potassium. Sodium counterions tend to increase the viscosity and may raise the viscosity above that required by the invention depending on interplay of other factors (for example, use of sodium might require also greater use of synthetic and/or co-solvent). Amine based counterions (trialkanolamine, ammonium, etc.) may have similar effect as potassium and can also be used. Other counterions which may be used include calcium, magnesium and zinc. As indicated, preferably the goal is to use counterions which have the least effect on viscosity and which will allow, together with other factors, pumpability as defined to be maintained.
In particular, as noted, it is preferred to use counterions which are 50% to 100%, more preferably 80% to 100% and even 100% potassium and/or amine (e.g., trialkanolamine). More preferably, counterion can be >75%, preferably 80% to 100% potassium.
It is also preferred to use saturated fatty acid and soap chains. Saturated chains generally have fewer color (e.g., browning) or odor problems and have generally good lather. Some unsaturates may be used, however, in that they help keep the product softer or pastier, for example. Typically, it is preferred to use >75%, more preferably 80% to 100%, even more preferably 96% to 100% and even 100% saturated chains.
Fatty acids and soaps of chain length C 14 or less are also generally preferred. Typically, a product of chain length only above C 14 would have very thick rheology. As discussed above, however, although having ≧50% short chain length (≦C 14 ) is preferred (and is encompassed by first compositional embodiment of the invention), a composition comprising <50% C 14 chain length, i.e., having >50% to 80%>C 14 chain length may be used but, in such cases (as in the second compositional embodiment), a minimum amount of synthetic surfactant and/or co-solvent (other than water) are used. Preferably, if solvent is used, it is an alkylene glycol solvent, such as, for example, dipropylene glycol or propylene glycol. As also noted above, use of synthetic and/or co-solvent as viscosity modifiers may also be found if sodium (or other counterion which may enhance viscosity too much) is used as soap counterion. The key is to manipulate ratios, counterions, synthetic and/or solvent to ensure the dispensing force of the resulting solution as per test described in the protocol is less than 300 Newtons (N) at steady state when measured at defined temperature.
Compositions of the invention should also comprise 0% to 30%, preferably 1% to 20%, more preferably 1% to 15%, even more preferably 1% to 10% by wt. synthetic non-soap surfactant. Again, in formulation with ≧50% chain length of no synthetic may be needed whereas, if >50% is >C 14 , some synthetic and/or co-solvent is required.
While syndet (synthetic detergent) is not required to produce, for example, a soft paste at 23° C., the syndet can be used to reduce low temperature viscosity (as can co-solvent, as noted below), for reasons noted.
Typically, synthetic surfactant, if present, will comprise at least one anionic surfactant (e.g., alkyl sulfate or isethionate). Preferably, the compositions will comprise a combination of anionic synthetic and amphoteric surfactant (e.g., betaine), especially when anionic comprises 50% or greater of such mixture of synthetics.
The concentrate compositions of the invention further comprise 10% to 40% by wt. solvent. The solvent comprises water or caustic neutralizing solution and may further comprise non-water co-solvent, e.g., polypropylene glycol.
Generally, the greater the amount of co-solvent, the less water required. It is also easy to keep viscosity within required range as more co-solvent and less water is used.
Viscosity reducing co-solvents of the invention include propylene glycol, dipropylene glycol, polypropylene glycol, ethylene glycol, polyethylene glycol and many other such related solvents as would be well known to those skilled in the art.
In one embodiment, glycerin can be used as co-solvent. While glycerin does not enhance low temperature stability, low viscosity product can be made with small amounts of glycerin. At levels above about 10%, higher amounts of co-solvent and/or synthetic surfactant might have to be used.
Finally, a suitable pumping viscosity is defined as a product which requires a dispensing force of less than 300N, measured as defined in protocol.
The concentrate formulations of the invention, in addition to comprising soap/fatty acid, solvent and synthetic surfactant, may also comprise various benefit agents and/or other ingredients which can typically be used in flowable, liquid personal care formulations.
Benefit agent may be any material that has potential to provide an effect on, for example, the skin.
The benefit agent may be water insoluble material that can protect, moisturize or condition the skin upon deposition from compositions of invention. These may include silicon oils and gums, fats and oils, waxes, hydrocarbons (e.g., petrolatum), higher fatty acids and esters, vitamins, sunscreens. They may include any of the agents, for example, mentioned at column 8, line 31 to column 9, line 13 of U.S. Pat. No. 5,759,969, hereby incorporated by reference into the subject application.
The benefit agent may also be a water soluble material such as glycerin, polyols (e.g., saccharides), enzyme and α- or β-hydroxy acid either alone or entrapped in an oily benefit agent.
The compositions may also comprise perfumes, sequestering agents such as EDTA or EHDP in amounts 0.01 to 1%, preferably 0.01 to 0.05%; coloring agents, opacifiers and pearlizers such as zinc stearate, magnesium stearate, TiO 2 , mica, EGMS (ethylene glycol monostearate) or styrene/acrylate copolymers.
The compositions may further comprise antimicrobials such as 2-hydroxy 4,2′4′trichlorodiphenylether (DP300), 3,4,4′-trichlorocarbanilide, essential oils and preservatives such as dimethyl hydantoin (Glydant XL 1000), parabens, sorbic acid, etc.
The compositions may also comprise coconut acyl mono or diethanol amides as suds boosters, and strongly ionizing salts such as sodium chloride and sodium sulfate may also be used to advantage.
Antioxidants such as, for example, butylated hydroxyl toluene (BHT) may be used advantageously in amounts of about 0.01% or higher if appropriate.
Cationic conditioner which may be used including Quatrisoft LM-200 Polyquaternium-24, Merquat Plus 3330-Polyquaternium 39; and Jaguar® type conditioners.
Composition may also include clays such as Bentonite® claims as well as particulates such as abrasives, glitter, and shimmer.
In a second embodiment of the invention, the invention relates to a packaged personal care or personal wash product which comprises a container or bottle which container or bottle comprises a label (e.g., indicating product logo or insignia) and/or advertising (e.g., print copy or other form of advertising) and which is intended for sale or distribution. The product comprises the soap formulation as set forth in the compositional embodiment of the invention.
In a preferred embodiment, the package or container has instructions which directs the consumer how and when to dilute the concentrated soap for use at home or elsewhere.
This packaged product can be used, for example, to save on cost of transporting a much heavier product to the point of sale (e.g., market) by the producer of the product and further to save cost (weight/energy, etc.) of the consumer to transport to their point of use. Further, it provides an ecologically friendly product which can be used as a source of advertising and good will.
In a third embodiment, the invention relates to a process for making concentrated soap.
This can be done either by reacting soap stock and fatty acid to neutralize and obtain ratios as required by the invention (e.g., in situ) that meet required viscosity targets for obtaining “pumpability”; and/or by mixing already prepared soap and fatty acid to obtain same desired ratios. In either case, the fatty acid and soap (preferred or not) are further reacted with optional synthetic and with solvent to form final concentrates.
EXAMPLES
Protocol
Rheological Measurement Protocol
In the rheological measurement used to determine pumpablility, a tube which is 31.4 mm in diameter is used. This tube is open on one end and sealed at the other end with an orifice plate which has a hole that is 3 mm in diameter and 12 mm in length. 150 ml of product is first loaded into the tube through the open end. A piston is then inserted into the open end of the tube and the product is pushed through the orifice at a flow rate of 0.5 ml/sec using an Instron universal testing machine. Using the Instron the force required to achieve this flow rate at steady state is measured. To account for frictional forces, a second run is then conducted without any product in the tube at the same piston velocity. The force required to push the piston without product is then subtracted from the force required to push the product through the orifice. This friction adjusted force is defined as the product dispensing force. According to the subject invention, products which are defined as “pumpable” require a force of less than 300 N at steady state. Steady state is defined as the longest measured interval over which the measured dispensing force is approximately consistent. In order for the measurement interval to be considered the steady state interval, more than 0.75 ml of product must be dispensed during the interval. This rheological measurement simulates flow from a tube and is a direct determination of the amount of force required to dispense the product from a tube. The measurements were conducted at two temperatures, 23° C. and 12° C. although, for purposes of keeping definition consistent, the measuring temperature is preferably 23° C. The temperature was held constant using a temperature controlled jacket surrounding the tube.
In short, pumpability is defined as requiring less than 300N of force to extrude through an orifice which is 3 mm in diameter and 12 mm in length as described above. Primarily, the test is to be conducted at a temperature of 23° C. (e.g., about room temperature)
Sample Preparation
The examples were made by first heating the fatty acid blend in a mixer to a temperature between 65-80° C. Of the total caustic required 75%-90% was added to the melted fatty acids while mixing at low speed during a period of 15 minutes. The mixing speed used was sufficient to thoroughly react the caustic. Synthetic detergent (SLES, CAPB or sodium lauryl sarcosinate) and co-solvent (dipropylene glycol, i.e., DPG or PPG-9) were then mixed into the fatty acid soap blend. After the addition of synthetic detergent and co-solvents, the remaining caustic was added and the mixed well. The final product was then cooled to room temperature.
DEFINITIONS
SLES=sodium lauryl ether sulfate
CAPB=cocoamidopropyl betaine
PPG=polypropylene glycol
HT=hard topped
Examples
Using the rheological protocol noted above, a commercial soap bar was tested. The soap bar represents the low water soap formulations which are in the prior art. These formulations have a high viscosity and can not be dispensed from a tube. The force which would be required for dispensing a soap bar according to the applied rheological protocol is 5160 N. This force is well above the critical range of the subject invention of 0-300 N.
For the raw materials used in the example formulations the chain length distributions are given in the table below:
HT
Com-
Coconut
mercial
Fatty
Lauric
Myristic
Palmitic
Stearic
Chain Length
Acid
Acid
Acid
Acid
Acid
Short Chain (<C8) (wt %)
0
0
0
0
0
Capric C10 (+C8) (wt %)
0
0
0
0
0
Lauric C12 (+C11) (wt %)
55.1
100
0
0
0
Myristic C14 (+C13)
21.9
0
100
2
2
(wt %)
Palmitic C16 (+C15)
11.4
0
0
92
45
(wt %)
Stearic C18 (+C17)
11.4
0
0
6
52
(wt %)
Long Saturates >= C19
0.2
0
0
0
0
(wt %)
Other
0
0
0
0
1
Examples 1-3 and Comparatives A & B
For a mixture of short chain potassium soaps, a critical window of neutrality exists where the soap mixture has a low enough viscosity (as defined in protocol) for dispensing from a tube. The examples below (Example 1-3 and Comparatives A & B) show that for neutralizations where the final soap:fatty acid ratio is between 2:1 and 20:1, a low viscosity soap mixture is obtained at room temperature. In all of the examples, more than 75% of the fatty acid chains used have chain length less than or equal to C 14 .
Examples 1-3 and Comparatives A & B
Ingredients by wt %
Formulation Number
Comp A
1
2
3
Comp B
HT Coco Fatty Acid
53.6%
51.4%
0.0%
47.6%
45.9%
Lauric Fatty Acid
0.0%
0.0%
34.1%
0.0%
0.0%
Myristic Fatty Acid
21.4%
20.5%
34.1%
19.0%
18.3%
KOH (45 wt %)
25.0%
28.1%
31.8%
33.4%
35.8%
Soap:Fatty Acid
1.75
2.74
4.71
10.50
Infinite
Solvent Concentration
17%
19%
22%
23%
25%
Dispensing Force @
412
232
53
38
1061
23° C.
Dispensing Force @
1106
12° C.
% of Fatty acid and soap
16.4%
16.4%
0.0%
16.4%
16.4%
with chain length > C 14
% of neutralization of
60%
70%
80%
90%
100%
final composition
As seen from examples above, when soap to fatty acid ratio was in ranges of invention and percent of fatty acid and soap having chain length ≦C 14 is greater than or equal to 50% (Example 1-2), the dispensing force was clearly less than 300N (defining pumpable viscosity). When outside such ratios (Comparative A has ratio of 1.75 and comparative B has infinite ratio), dispensing force is well above 300N. It is noted that these compositions comprise no solvent other than water and no syndet and that, measured at 12° C., viscosity is not pumpable as defined.
Example 4 and Comparative C
If more than 50% of the used fatty acid has a chain length greater than C 14 , the soap mixture is too thick to be dispensed from a tube, even when measured at 73° C. (Comparative C). However, with the addition of co-solvent and synthetic surfactant (e.g., SLES and CAPB), the viscosity is within a range which is suitable for tube dispensing (Example 4).
Ingredients by wt %
Formulation Number
Comp C
4
HT Coco Fatty Acid
29.5%
0.0%
Lauric Fatty Acid
0.0%
13.0%
Myristic Fatty Acid
9.5%
12.2%
Palmitic Fatty Acid
7.5%
4.5%
Stearic Fatty Acid
22.1%
23.6%
KOH (45 wt %)
31.5%
0.0%
KOH (85 wt %)
0.0%
13.1%
SLES (70 wt %)
0.0%
9.6%
CAPB (28 wt %)
0.0%
8.6%
DPG
0.0%
9.0%
Water
0.0%
6.4%
Soap:Fatty Acid
9.74
10.58
Dispensing Force @ 23° C.
383
38.8
% of Fatty acid and soap with
51.83%
51.30%
chain length % > C 14
% of neutralization of final
89.38%
90.14%
composition
Solvent in final composition
21.88%
30.00%
As seen, therefore, even though both examples have >50% of chain length greater than C 14 (which make viscosity higher), the interplay of solvent and synthetic surfactant brings the defined dispensing force from well above 300 (383N) to well below (38.8N).
Examples 5 and 6 and Comparative D
The viscosity of soap formulations are low enough for dispensing from a tube at solvent concentrations between 10 and 40%. Comparative D has a solvent concentration below 10% and is not dispensable from a tube. Examples 3, 5 and 6 have the same fatty acid blend as Comparative Example D but have a solvent concentration in the range of 10 to 40%. All of these formulations have a dispensing force less than 300 N measured at 23° C. Comparative D has less than 10% solvent and much higher dispensing force. Comparison of Examples 3 and 6 also shows that the addition of the co-solvent DPG lowers the dispensing force to below 300N measured at 12° C. (from 1106N to 70N). This demonstrates that co-solvent can be used to improve low temperature dispensability.
Ingredients by wt %
Formulation Number
Comp D
5
6
HT Coco Fatty Acid
56.5%
37.2%
43.4%
Myristic Fatty Acid
22.5%
14.8%
17.3%
KOH (45 wt %)
0.0%
26.1%
30.4%
KOH (85 wt %)
21.0%
0.0%
0.0%
DPG
0.0%
0.0%
8.9%
Water
0.0%
21.9%
0.0%
Soap:Fatty Acid
10.49
10.50
10.50
Solvent Concentration
8.9%
40.0%
30.0%
Dispensing Force @ 23° C.
19094
269
56.8
Dispensing Force @ 12° C.
70
% of Fatty acid and soap
16.45%
16.45%
16.45%
with chain length > C 14
% neutralization of final
89.97%
89.98%
89.98%
composition
Examples 7-9
Like co-solvents, synthetic surfactant can also be used to reduce or maintain the dispensing force below 300 N, particularly low temperature dispensing. Examples 7-9 are two formulations which demonstrate the effect of synthetic surfactants on partially neutralized soap formulations. When compared to Example 3, the addition of synthetic surfactants reduces the dispensing force at both 23° C. and 12° C.
Ingredients by wt %
Formulation Number
7
8
9
HT Coco Fatty Acid
37.8%
37.8%
37.8%
Myristic Fatty Acid
15.1%
15.1%
15.1%
KOH (45 wt %)
26.5%
0.0%
0.0%
KOH (85 wt %)
0.0%
14.0%
14.0%
SLES (70 wt %)
9.5%
9.5%
0.0%
CAPB (28 wt %)
8.5%
8.5%
0.0%
Sodium Lauryl Sarcosinate
0.0%
0.0%
30.1%
(30 wt %)
DPG
0.0%
3.0%
3.0%
Water
2.6%
12.1%
0.0%
Soap:Fatty Acid
10.50
10.49
10.49
Solvent Concentration
30.0%
30.0%
30.0%
Syndet Concentration
9.0%
9.0%
9.0%
Dispensing Force @ 23° C.
51.5
11.2
6.7
Dispensing Force @ 12° C.
460
91
482
% of Fatty acid and soap
16.45%
16.45%
16.45%
with chain length > C 14
% of neutralization of final
89.98%
89.97%
89.97%
composition | The present invention provides concentrated soap compositions formulated in such a manner that, quite unpredictably, despite high concentration of soap, they have viscosity which allows them to be pumped from, for example, consumer packaging (e.g., bottles) and/or transit or storage points during manufacture (e.g., pipes, storage tanks, etc.). | 0 |
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application Nos. 60/197,118 and 60/197,526, both filed Apr. 14, 2000. This application is related to U.S. application Ser. No. 09/234,349, filed Jan. 20, 1999, which is a divisional application of U.S. Pat. No. 5,902,441, issued May 11, 1999, and to U.S. application Ser. No. 09/416,787, which is a continuation-in-part of U.S. Pat. No. 6,007,318. The teachings of each of these references are incorporated herein by reference in their entirety.
BACKGROUND
[0002] Rapid prototyping involves the production of prototype articles and small quantities of functional parts, as well as structural ceramics and ceramic shell molds for metal casting, directly from computer-generated design data. There are a variety of methods to form a three-dimensional article including a selective laser-sintering process as described in U.S. Pat. No. 4,863,568, which is incorporated herein by reference.
[0003] Three-dimensional printing is a process invented by Sachs et al. at Massachusetts Institute of Technology in the early 1980's. In accordance with the process, an ink-jet printhead is used to deposit a liquid ink or binder onto a print plane composed of a powdered receiving medium. The combination of liquid binder and solid powder solidifies to form a finished article.
[0004] U.S. Pat. No. 5,204,055, incorporated herein by reference, describes an early three-dimensional printing technique that involves the use of an ink-jet printing head to deliver a liquid or colloidal binder material to layers of powdered material. The three-dimensional inkjet printing technique (hereafter “liquid-binder method”) involves applying a layer of a powdered material to a surface using a counter roller. After the powdered material is applied to the surface, the ink-jet printhead delivers a liquid binder to the layer of powder. The binder infiltrates into gaps in the powder material, hardening to bond the powder material into a solidified layer. The hardened binder also bonds each layer to the previous layer. After the first cross-sectional portion is formed, the previous steps are repeated, building successive cross-sectional portions until the final article is formed. Optionally, the binder can be suspended in a carrier that evaporates, leaving the hardened binder behind. The powdered material can be ceramic, metal, plastic or a composite material, and can also include fiber. The liquid-binder material can be organic or inorganic. Typical organic binder materials used are polymeric resins, or ceramic precursors such as polycarbosilazane. Inorganic binders are used where the binder is incorporated into the final articles; silica is typically used in such an application.
[0005] In the technology of ink-jet printing, there are a number of different types of printheads distinguished by the mechanism by which ink is ejected onto the printing plane. The two broadest classes of printheads are called, “continuous-jet” and “drop-on-demand.” In a continuous-jet printhead, a liquid ink or binder is projected continuously through a nozzle. To print segmented lines, the jet is deflected alternatively onto the print plane or in to a collector that masks the printing plane. In a drop-on-demand printhead, ink or binder is ejected when it is needed by sending an impulse, most usually electrical, that causes an actuator in the printhead to eject a droplet of ink or binder onto the print plane.
SUMMARY
[0006] The use of liquid-binder printing techniques with a thermal (bubble) printhead can present reliability problem associated with the spray nozzle becoming clogged with the binder material. Clogging can occur when binders having high levels of solids are used. The problem with clogging requires frequent interruptions of the build in order to clean the spray nozzle; this problem also increases the time and labor required to build parts and to maintain the equipment. Therefore, although the liquid-binder printing technique represents an advance in speed and cost over the selective laser-sintering process, it suffers from reliability problems that slow down the build rate, increasing labor and equipment maintenance costs. This problem interferes with the potential speed advantage of increased printing capability presented by the plurality of spray nozzles.
[0007] The materials for fabricating three-dimensional objects lead to a materials system and method that produce both appearance models and small numbers of functional parts in an office environment. The materials system can include at least one solid filler and a liquid binder composition. Particular binder compositions can be effectively deposited using an electromechanical printhead having suitable components. The fabrication methods can be quick, reliable, safe, and inexpensive.
[0008] An article can be made of a mixture of particles including adhesive and at least one filler. The adhesive may be activated by a fluid including a solvent. Optionally, the binder can also include various processing aids or additions that modify the working properties of the fluid and adhesive or that enhance the mechanical properties of the finished article. The mixture of particles can also optionally include particles of fiber and various processing aids. The activated adhesive causes the filler particles to adhere together, and to adhere to previously formed adjacent layers. Adhesive can be supplied to the article by coating it on the fiber and/or filler, by directly mixing it with the fiber and filler before delivering the fluid and/or by dissolving or mixing the adhesive in the fluid before the fluid is delivered to the mixture of particles.
[0009] A particular method for producing such articles can include applying a layer of the above-mentioned mixture onto a flat surface that can be indexed downward. Cross-sectional portions of an article can be defined by delivering an activating fluid, the adhesive, to the layer of the mixture of particles in a predetermined two-dimensional pattern. The fluid activates the adhesive, and the activated adhesive causes the particles to adhere together in an essentially solid layer. After the first cross-sectional portion of the article is formed, the movable surface can be indexed downward by an amount corresponding to the desired layer thickness. Successive layers of the mixture of particles are applied to previous layers in the same manner. Application of the fluid using an electromechanical ink-jet print head follows the application of each successive layer of the mixture of particulate material.
[0010] Depositing a layer of the mixture of particulate material and delivering the fluid to the layer can be repeated until the required number of cross-sectional portions have been built, completing formation of the article. After formation of the article has been completed, it typically remains immersed in a bed of unbound particulate material, where it can remain until the article is completely dry. Delicate features of the article remain supported by the unbound particulate material while drying. The finished article can then be removed from the bed of unbound particulate material and any excess unbound particulate material clinging to the finished article can be removed by a suitable cleaning process. For example, excess powder can be removed by vacuuming it off the article, by blowing it off the article, and by brushing to remove any powder left in crevices. In addition, the finished article can be placed in an oven for more rapid drying.
[0011] After cleaning, optional post-processing actions can include heat-treating, resin or wax infiltration, painting and sanding. Heat treating and infiltration can increase the strength and durability of the finished article. Infiltration can reduce porosity, making the article water resistant and more readily sanded. Painting the article can provide a more aesthetically pleasing appearance, and may also contribute to the strength and water resistance of the final articles. Sanding improves the surface smoothness, reducing any surface irregularities caused, for example, by fiber penetrating through the surface. Parts can be glued or fastened, or used as patterns for subsequent molding operations.
[0012] Various materials systems and methods offer the advantages of being able to fabricate relatively complex shapes reliably, quickly, safely and inexpensively compared to the selective laser-sintering and liquid-binder methods. Because various materials used in the present system present little or no problems with clogging, higher reliability can be offered relative to prior art methods, particularly prior art methods in which high levels of suspended solids are contained in the binder. The higher reliability results in reduced build times compared with prior art methods. Further, embodiments can be made and practiced more economically than prior art methods because inexpensive equipment and materials can be used, and the high reliability associated with materials and methods reduces cost even further. In addition, because non-toxic materials can be used, these methods can be carried out safely in a typical office environment.
[0013] Additionally, the use of electromechanical ink-jet printheads to deliver the fluid compositions allows for the incorporation of thermally-sensitive adhesives in the fluid due to the fact that electromechanical ink-jet printheads typically operate at ambient-temperature. Further, fluids with a large amount of dissolved or suspended solids subject to degradation with temperature excursions can likewise be better accommodated by an electromechanical printhead relative to a thermal printhead. The use of fluids with higher solids content with an electromechanical printhead further allows for the formation of materials that will shrink less (due to fewer escaping components) and that have higher strength and greater dimensional stability than materials formed with more dilute binders. Further still, the incorporation of adhesives in the activating fluid and the delivery of that fluid to the particulate bed allows for an increased amount of adhesive to be incorporated into the final part.
[0014] The composition selectively adhere particulate material to form a solid object in a three-dimensional printer. In one embodiment, the composition comprises a nonaqueous organic monomeric compound. That compound can include at least one of an alcohol, an ester, an ether, a silane, a vinyl monomer, an acrylic monomer, or a methacrylate monomer.
[0015] The composition can include a solvent and a solute, and in one embodiment, the compound is the solvent. The solvent can include an alcohol such as methyl alcohol, ethyl alcohol, isopropanol, or t-butanol. In alternative embodiments, the solvent includes an ester that includes at least one of ethyl acetate, dimethyl succinate, diethyl succinate, dimethyl adipate, or ethylene glycol diacetate.
[0016] In alternative embodiments, the compound is a solvent for a resin in the particulate material. The resin can include at least one of shellac, polyvinyl pyrrolidone, polyvinyl acetate, polyvinyl alcohol, polystyrene, styrene-butadiene copolymer, or acrylonitrile-butadiene-styrene copolymer.
[0017] Additionally, organic acids and sugars such as sucrose, dextrose, malic acid, and sodium citrate, and other compounds such as urea and hydrolized amino acids can be used as solutes in water solution. These compounds bind the particulate material together by drying in the powder, and not have any appreciable solvent character on their own.
[0018] The monomeric compound can include a mixed monomer vinyl-silane and can include vinyltriisopropoxysilane.
[0019] The acrylic monomer can include at least one of tri(propylene glycol) diacrylate, ethylene glycol phenyl ether acrylate, or 1,6 hexanediol diacrylate. The methacrylic monomer can include at least one of 1,3 butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, butyl methacrylate, 1,6 hexanediol dimethacrylate, or di(propylene glycol) allyl ether methacrylate.
[0020] The compound can be curable, in combination with a photoinitiator in a solid, by ultraviolet radiation having a wavelength between about 320-500 nm and an energy density of about 1 joule/cm 2 .
[0021] The particulate material can include a filler that includes an inorganic compound. In one embodiment, the filler includes at least one of clay, aluminum oxide, silicon dioxide, aluminum silicate, potassium aluminum silicate, calcium silicate, calcium hydroxide, calcium aluminate, calcium carbonate, sodium silicate, zinc oxide, titanium dioxide, or magnetite. A printing aid can be dispersed throughout the filler. The printing aid can include at least one of sorbitan trioleate, sorbitan mono-oleate, sorbitan monolaurate, polyoxyethylene sorbitan mono-oleate, polyethylene glycol, soybean oil, mineral oil, propylene glycol, fluroaklkyl polyoxyethylene polymers, glycerol triacetate, polypropylene glycol, ethylene glycol octanoate, ethylene glycol decanoate, ethoxylated derivatives of 2,4,7,9-Tetramethyl-5-decyne-4,7-diol, oleyl alcohol, or oleic acid.
[0022] A binder composition is also provided, which can include an adhesive in combination with a fluid, for selectively adhering particulate material to form a solid object in a three-dimensional printer. In one embodiment, the adhesive can include a nonaqueous organic monomeric compound.
[0023] In alternative embodiments, an adhesive for selectively adhering particulate material to form a solid object in a three-dimensional printer includes an anionically ionizable polymer consisting of compounds selected from the group including polymethacrylic acid, polymethacrylic acid sodium salt, and sodium polystyrene sulfonate.
[0024] In other embodiments, the adhesive includes a cationic polymer such as polyethyleneimine and polydiallyldimethylammonium chloride. In other embodiments, the adhesive includes a nonionic polymer. The polymer can include at least one of polyvinyl pyrrolidone, polyvinyl pyrrolidone copolymer with polyvinyl acetate, polyvinyl alcohol, polyvinyl methyl ether, polyacrylamide, or poly-2-ethyl-2-oxazoline. In yet other embodiments, the adhesive includes a polymer selected from the group consisting of polymethacrylic acid, polymethacrylic acid sodium salt, sodium polystyrene sulfonate, and polyethyleneimine.
[0025] In further embodiments, the adhesive includes a waterborne colloid such as polymethyl methacrylate, polystyrene, natural rubber, polyurethane, polyvinyl acetate, and alkyd resins. In yet other embodiments, the adhesive includes an inorganic solute selected from the group consisting of sodium polyphosphate, sodium tetraborate, sodium chloride, ammonium nitrate, potassium sulfate, ammonium chloride, and calcium formate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 schematically illustrates a first layer of a mixture of particulate material deposited onto a downwardly movable surface on which an article is to be built, before any fluid has been delivered;
[0027] FIG. 2 schematically illustrates an electromechanical ink-jet nozzle delivering an activating fluid to a portion of the layer of particulate material of FIG. 1 in a predetermined pattern;
[0028] FIG. 3 schematically illustrates a view of a final article made from a series of steps illustrated in FIG. 2 enclosed in the container while it is still immersed in the loose unactivated particles;
[0029] FIG. 4 schematically illustrates a view of the final article from FIG. 3 .
[0030] The foregoing and other objects, features and advantages will be apparent from the following more particular description of embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
DETAILED DESCRIPTION
[0031] A materials system for three-dimensional printing comprises a mixture of particles including a filler and possibly an adhesive. The materials system can also include a fibrous component, a printing aid for reducing edge curl due to uneven curing of the adhesive and resultant distortion of a part that is three-dimensionally printed, and an activating fluid comprising additional adhesive and a solvent that activates the adhesive. The activating fluid can also include such processing aids as a humectant, a flowrate enhancer, and a dye. The fluid activates the adhesive in the particulate mixture, adhesively bonding the material together to form an essentially solid article.
[0032] FIG. 1 schematically illustrates a first layer of a mixture of particulate material deposited onto a downwardly movable surface on which an article is to be built, before any fluid has been delivered. According to the method, a layer or film of particulate material 20 is applied on a downwardly movable surface 22 of a container 24 . The layer or film of particulate material can be formed in any manner; in one embodiment, the particulate material is applied using a counter roller. The particulate material applied to the surface includes a filler and, possibly, adhesive.
[0033] As used herein, “adhesive” is meant to define a component that forms the primary adhesive bonds in the mixture of material between portions of the mixture that were separate prior to delivery of the activating fluid. The adhesive can be included both in the particle mixture and in the activating fluid. As used herein, a “filler” is meant to define a component that is solid prior to application of the activating fluid, which is substantially less soluble in the fluid than the adhesive, and which gives structure to the final article.
[0034] According to a particular embodiment, the particulate mixture includes a reinforcing fiber, or a reinforcing fibrous component, added to provide structural reinforcement to the final article. The particulate material may include a plurality of particles of mean diameter of about 10-300 microns. As used herein, “fiber” or “fibrous component” is meant to define a component that is solid prior to application of the activating fluid, which can be but is not necessarily insoluble in the fluid, that is added to increase the final article strength. The reinforcing fiber length is restricted to a length approximately equal to the thickness of the layer of particulate mixture. The reinforcing fiber is typically about 60 to about 200 microns in length, and is included in an amount not greater than 20 percent, by weight, of the total mixture.
[0035] Additionally, a stabilizing fiber can be added to the filler to provide dimensional stability to the final article, as well as to slightly increase the article strength. Spreading the particulate mixture with the counter roller becomes increasingly difficult as friction caused by an excess of stabilizing fiber in the mixture increases, reducing the packing density. Restricting both the amount and length of the stabilizing fiber increases the packing density of the mixture resulting in finished parts of greater strength. The stabilizing fiber may be restricted to a length of less than half of the reinforcing fiber, in an amount not greater than 30 percent, by weight, of the total mixture. Optimal values can be determined with routine experimentation using, for example, a counter roller.
[0036] According to another particular embodiment, a printing aid in the form of an emulsifier, such as sorbitan trioleate (commercially available as SPAN 85 from Sigma Chemical Co., St. Louis, Mo., USA), can be added to the particulate mixture to prevent distortions in printing. The printing aid prevents fine particles of the mixture from becoming airborne while the fluid is dispensed from the print head which would distort the printed article. Lecithin, which also serves as a printing aid can be used as well.
[0037] The composition of the particulate mixture and fluid (binder) of a particular embodiment using a polymer solution as the adhesive is provided in Table 1, below. The composition of the particulate mixture and fluid (binder) of a particular embodiment using a colloidal suspension as the adhesive is provided in Table 2, below.
TABLE 1 Particle Example Example Size Particular Composition Composition Range Ingredient Compound Range (W/W) (W/W) (μm) Particulate Mixture Adhesive sucrose 10-50% 30% 10 Reinforcing cellulose 0-20% 10% 100 Fiber Filler maltodextrin 0-80% 50% <300 (dextrose equivalent = 5) Stabilizing cellulose 0-30% 10% 60 Fiber Printing lecithin 0-3% 0.27% N/A Aids sorbitan trioleate 0-3% 0.03% N/A Fluid Solvent water 20-88% 68% N/A Solvent isopropyl alcohol 0-5% 1% N/A water-sol. sulfonated 10-50% 25% N/A adhesive polystyrene Humectant glycerol 0-15% 5% N/A Flowrate diethylene glycol 0-10% 1% N/A Enhancer monobutyl ether Dye naphthol blue- 0-0.1% 0.1% N/A black
[0038]
TABLE 2
Particle
Example
Example
Size
Particular
Composition
Composition
Range
Ingredient
Compound
Range (W/W)
(W/W)
(μm)
Particulate Mixture
Adhesive
sucrose
10-50%
30%
10
Reinforcing
cellulose
0-20%
10%
100
Fiber
Filler
maltodextrin
0-80%
50%
<300
(dextrose
equivalent = 5)
Stabilizing
cellulose
0-30%
10%
60
Fiber
Printing
lecithin
0-3%
0.27%
N/A
Aids
sorbitan
0-3%
0.03%
N/A
trioleate
Suspending
water
20-88%
72%
N/A
Fluid
Solvent
isopropyl
0-5%
1%
N/A
alcohol
Colloid
polyvinyl
10-50%
20%
50-500
Adhesive
acetate
nm
Inorganic
acetic acid
0-2%
1%
N/A
Buffer
Humectant
glycerol
0-15%
5%
N/A
Flowrate
diethylene
0-10%
1%
N/A
glycol
Enhancer
monobutyl
ether
Dye
naphthol blue-
0-0.1%
0.1%
N/A
black
[0039] FIG. 2 schematically illustrates an electromechanical ink-jet nozzle delivering an activating fluid to a portion of the layer of particulate material of FIG. 1 in a predetermined pattern. The fluid 26 is delivered to the layer or film of particulate material in any predetermined two-dimensional pattern (circular, in the figures, for purposes of illustration only), using any convenient mechanism, such as a drop-on-demand (hereinafter “DOD”) electromechanical printhead driven by customized software which receives data from a computer-assisted-design (hereinafter “CAD”) system as described in greater detail in U.S. application Ser. No. 09/416,707, which is incorporated herein by reference in its entirety. Examples of suitable piezoelectric printheads include the Tektronix PHASOR 340 printhead by Xerox (Stanford, Conn., USA), the PJN 320 printhead from PicoJet, Inc. (Hillsboro, Oreg., USA), and the EPSON 900 printhead from Epson America, Inc. (Portland, Oreg., USA). A suitable solenoid valve printhead is the 1200 Hz INKA printhead from The Lee Co. (Westbrook, Conn., USA).
[0040] In one embodiment, where adhesive is mixed with the other particles, the first portion 30 of the particulate mixture is activated by the fluid, causing the activated adhesive to adhere the particles together to form an essentially-solid circular layer that becomes a cross-sectional portion of the final article. As used herein, “activates” is meant to define a change in state from essentially inert to adhesive. When the fluid initially comes into contact with the particulate mixture, it immediately flows outward (on the microscopic scale) from the point of impact by capillary action, dissolving the adhesive in the particulate mixture within the first few seconds. A typical droplet of activating fluid has a volume of about 50 pL, and spreads to about 100 microns once it comes into contact with the particulate mixture. As the solvent dissolves the adhesive, the fluid viscosity increases dramatically, arresting further migration of the fluid from the initial point of impact.
[0041] An adhesive can be dissolved, suspended, or otherwise included in the activating fluid before delivery, in addition to being in the powder mixture. The adhesive that is pre-mixed with the activating fluid will already be activated when delivered to the powder mixture and will adhere filler and other particles to form a solid, agglomerated structure, as described above.
[0042] Within a few minutes after the activating fluid is delivered to the particulate mixture, the fluid (with adhesive dissolved or suspended therein) infiltrates the less-soluble and slightly-porous particles, forming adhesive bonds between the filler and the fiber. The activating fluid is capable of bonding the particulate mixture in an agglomerated mass that is several times the mass of a droplet of the fluid. As volatile components of the fluid evaporate, the adhesive bonds harden, joining the filler and, optionally, fiber particulates into a rigid structure, which becomes a cross-sectional portion of the finished article.
[0043] Any portion of the particulate mixture 32 that was not exposed to the fluid remains loose and free-flowing on the movable surface. The unbound particulate mixture can be left in place until formation of the final article is complete. Leaving the unbound, loose-particulate mixture in place ensures that the article is supported during processing, allowing features such as overhangs, undercuts, and cavities (not illustrated, but conventional) to be defined without using support structures. After formation of the first cross-sectional portion of the final article, the movable surface is indexed downward.
[0044] Using, for example, a counter-rolling mechanism, a second film or layer of the particulate mixture is then applied over the first, covering both the rigid first cross-sectional portion, and any loose particulate mixture by which it is surrounded. A second application of fluid follows in the manner described above, forming adhesive bonds between a portion of the previous cross-sectional portion, the filler, and, optionally, fiber of the second layer, and hardening to form a second rigid cross-sectional portion added to the first rigid cross-sectional portion of the final article. The movable surface is again indexed downward.
[0045] The previous steps of applying a layer of particulate mixture, applying the fluid, and indexing the movable surface downward are repeated until the final article is completed.
[0046] FIG. 3 schematically illustrates a view of a final article made from a series of steps illustrated in FIG. 2 enclosed in the container while it is still immersed in the loose unactivated particles. The final article can be completely immersed in a bed 36 of unactivated particulate material. Alternatively, those skilled in this art would know how to build an article in layers upward from an immovable platform, by successively depositing, smoothing and printing a series of such layers.
[0047] FIG. 4 schematically illustrates a view of the final article from FIG. 3 . The unactivated particulate material can be removed by blown air or a vacuum. After removal of the unactivated particulate material from the final article 38 , post-processing treatment may be performed, including cleaning, infiltration with stabilizing materials, painting, etc.
[0048] The method of the present invention is capable of producing features on the order of about 250 μm. The accuracy achieved by the method of the present invention is in the range of about +/−250 μm. Shrinkage of the final article is about 1%, which can easily be factored into the build to increase accuracy.
[0000] Adhesive
[0049] The adhesive is a compound selected for the characteristics of high solubility in the activating fluid, low solution viscosity, low hygroscopicity, and high bonding strength. The adhesive should be highly soluble in the solvent in order to ensure that it is incorporated rapidly and completely into the activating fluid. Low solution viscosity can be used to ensure that activating fluid having adhesive dissolved therein will migrate quickly to sites in the powder bed to adhesively bond together the reinforcing materials. If the adhesive is naturally a solid, the adhesive can be milled as finely as possible prior to mixing with the filler and/or activating fluid and/or prior to coating the filler particles. The fine particle size enhances the available surface area, enhancing dissolution in the solvent, without being so fine as to cause “caking”, an undesirable article characteristic. Typical adhesive particle grain sizes are about 5-50 μm. Low hygroscopicity of an adhesive used in the particulate mixture avoids absorption of excessive moisture from the air, which causes “caking”, in which unactivated powder spuriously adheres to the outside surface of the part, resulting in poor surface definition.
[0050] Various types of adhesives that can be used with this invention are further and more specifically described under the section entitled, “Activating Fluid,” below.
[0000] Filler
[0051] The filler of the present invention is a compound selected for the characteristics of insolubility in the activating fluid, or extremely low solubility in the activating fluid, rapid wetting, low hygroscopicity, and high bonding strength. The filler provides mechanical structure to the hardened composition. Sparingly soluble filler material is used in particular, although insoluble filler material can also be used. The filler particles become adhesively bonded together when the adhesive dries/hardens after the activating fluid has been applied. The filler can include a distribution of particle grain sizes, ranging from the practical maximum of about 200 μm downward, to the practical minimum of about 5 μm. Large grain sizes appear to improve the final article quality by forming large pores in the powder through which the fluid can migrate rapidly, permitting production of a more homogeneous material. Smaller grain sizes serve to reinforce article strength.
[0052] Compounds suitable for use as the filler of the present invention can be selected from the same general groups from which the adhesive is selected, provided that the solubility, hygroscopicity, bonding strength and solution viscosity criteria described above are met. Examples of such fillers, which can be used alone or in combination, include starches such as maltodextrin, clay, cellulose fiber, glass, limestone, gypsum, aluminum oxide, aluminum silicate, potassium aluminum silicate, calcium silicate, calcium hydroxide, calcium aluminate, and sodium silicate; metals; metal oxides such as zinc oxide, titanium dioxide, and magnetite (Fe 3 O 4 ); carbides such as silicon carbide; and borides such as titanium diboride. In other embodiments, the filler is limestone, which can be used alone or in combination with other inorganic fillers. For example, the filler can be a combination of plaster (0-20%), limestone (calcium carbonate) (40-95%) and glass beads (0-80%). Generally the filler materials are selected on the basis of their ability to bond with the adhesive components, combined with the spreading characteristics of the dry powder. The selection of the solvent also typically determines which filler can be used.
[0000] Reinforcing Fiber
[0053] The reinforcing fiber can be insoluble or can dissolve substantially slower in the fluid than the adhesive dissolves. The reinforcing fiber is a stiff material chosen to increase the mechanical reinforcement and dimensional control of the final article without making the powder too difficult to spread. In order to promote wetting of the reinforcing fibers, the chosen fibers have a high affinity for the solvent. A particular embodiment includes a fiber length approximately equal to the layer thickness, which provides the greatest degree of mechanical reinforcement. Using longer fibers adversely affects the surface finish, and using too much fiber of any length can make spreading of the powder increasingly difficult. Fibrous material suitable for reinforcing the present invention includes, but is not limited to polymeric fiber, ceramic fiber, graphite fiber and fiberglass. The polymeric fiber may be cellulose and cellulose derivatives or substituted or unsubstituted, straight or branched, alkyl or alkene, including monomers up to eight carbon atoms in length. Specific useable fibrous materials include, but are not limited to cellulose fiber, silicon carbide fiber, graphite fiber, aluminosilicate fiber, polypropylene fiber, fiberglass, nylon, and rayon.
[0054] As indicated in Table 1, both the reinforcing fiber and the stabilizing fiber are can be cellulose. Some of the useful properties of cellulose making it particularly suitable for use in connection with the invention are low toxicity, biodegradability, low cost and availability in a wide variety of lengths.
[0055] Further considerations when selecting the adhesive, filler and fiber depend on the desired properties of the final article. The final strength of the finished article depends largely on the quality of the adhesive contacts between the particles of the mixture, and the size of the empty pores that persist in the material after the adhesive has hardened; both of these factors vary with the grain size of the particulate material. In general, the mean size of the grains of particulate material should not be larger than the layer thickness. A distribution of grain sizes increases the packing density of the particulate material, which in turn increases both article strength and dimensional control.
[0000] Printing Aid
[0056] As indicated in Table 1, sorbitan trioleate (SPAN 85) is used as a printing aid in the exemplary particulate mixture. Sorbitan trioleate is a liquid which is only slightly soluble in water. By adding a small amount to the powder, the sorbitan trioleate provides a light adhesion between powder grains before printing, thereby reducing dust formation. After printing, the sorbitan trioleate continues to adhere insoluble grains together for a short time until it dissolves. This effect tends to reduce distortion in printed layers in the brief time that is required for the adhesive to dissolve and redistribute in the powder. Hydrophillic grades of lecithin are particularly suitable. A wide variety of other liquid compounds work for the same purpose. Polypropylene glycol (PPG), especially with a molecular weight of about 400, and citronellol are two examples. Other suitable printing aides include ethylene glycol octanoate, ethylene glycol decanoate, and ethoxylated derivatives of 2,4,7,9-Tetramethyl-5-decyne-4,7-diol. Sorbitan trioleate can be used in combination with lethicin, which also functions as a printing aid. Other liquid compounds that can be used as printing aids include sorbitan mono-oleate, sorbitan monolaurate, polyoxyethylene sorbitan mono-oleate, polyethylene glycol, soybean oil, mineral oil, propylene glycol, fluroalkyl polyoxyethylene polymers, glycerol triacetate, oleyl alcohol, and oleic acid.
[0000] Activating Fluid
[0057] The fluid of the present invention is selected to comport with the degree of solubility required for the various particulate components of the mixture, as described above. The fluid includes a solvent in which the adhesive is active, particularly soluble, and can include processing aids such as a humectant, a flowrate enhancer, and a dye. An ideal solvent is one in which the adhesive component of the powder is highly soluble, and in which both the filler and fiber are substantially less soluble. The solvent can be aqueous or non-aqueous, although aqueous solvents offer some advantages. Suitable solvents can be selected from the following non-limiting list: water, methyl alcohol, ethyl alcohol, isopropanol, t-butanol, ethyl acetate, dimethyl succinate, diethyl succinate, dimethyl adipate, and ethylene glycol diacetate.
[0058] The activating fluid, which can have adhesive pre-mixed, is also referred to as the “binder.” The function of the binder is to infiltrate the insoluble or semi-soluble particle mixture and to bond the grains together. The activating fluid, with adhesive included, can belong to any one of the following classes: (1) polymer solutions, (2) colloidal suspensions, (3) inorganic (salt) solutions, (4) organic monomeric solutions, (5) non aqueous liquids. Classes 1-4 can be aqueous. The following description of particular fluids and adhesives are not meant to be limiting, other suitable compounds may be used in place of or in combination with the listed compounds.
[0059] There also exists a collection of water-based compounds that have been found to work particularly well in electromechanical printheads. In the first category, a water-soluble polymer can be dissolved in the binder to form a relatively low viscosity solution. Of these, there are a few particularly suitable polymers. These are anionically ionizable polymers, cationic polymers and nonionic polymers. The anionically ionizable polymers include polymethacrylic acid, polymethacrylic acid sodium salt, and sodium polystyrene sulfonate. The cationic polymers include polyethyleneimine and polydiallyldimethyl ammonium chloride. As a class, polyethyleneimine comes in two forms, linear and branched, both of which are useful. The nonionic soluble polymers that are particularly useful as binders are polyvinyl pyrrolidone, polyvinyl pyrrolidone copolymer with polyvinyl acetate, polyvinyl alcohol, polyvinyl methyl ether, polyacrylamide, and poly-2-ethyl-2-oxazoline.
[0060] In a typical embodiment, a low molecular weight polymer such as sodium polystyrene sulfonate is dissolved in water to form a solution containing approximately 20% solids by weight. A cosolvent such as isopropyl alcohol, at approximately 1% to 5% by weight, can modify the viscosity of the solution by controlling the conformation of the polymer chains in solution. A humectant such as glycerol used at approximately 5% to 10% will reduce the tendency of the binder to dry in the printhead. Other solution parameters such as pH and salt concentration may be used to modify flow properties. Added salts tend to lower the viscosity of binders that include a polyelectrolyte, such as sodium chloride, sodium phosphate, sodium sulfate, and potassium sulfate.
[0061] In the second category, colloidal suspensions of materials can be used as binders in three-dimensional printing. Organic latexes such as polymethyl methacrylate, polystyrene, styrenated polyacrylic acid, natural rubber, polyurethane latex, polyvinyl acetate latex, and alkyd resin latex are materials that can be applied to the process. Additionally, inorganic suspensions such as colloidal alumina, clay, and colloidal graphite could all be used to for solid articles containing substantial amounts of these technologically important materials. The advantage of using a colloid over a solution is that a very large content of solid materials can be suspended without greatly increasing the viscosity of the fluid.
[0062] The first two classes do not necessarily exclude one another. Very often, a soluble polyelectrolyte will be used to stabilize a suspension of solid particles. The polyelectrolyte will contribute to the structure of the finished article in addition to the dispersed particles.
[0063] A typical embodiment of a colloid-based binder comprises a polyvinyl acetate including approximately 30% solids. Additional additives such as triethanolamine at 2% to 5% by weight are used to control the pH of the suspension. Additionally, a humectant such as glycerol at 5% to 10% is used to reduce the tendency of the latex to dry in the printhead during idle periods.
[0064] In the third category, inorganic solutes can be dissolved in an aqueous solvent and printed as a binder. Glass-forming solutes such as sodium silicate, sodium polyphosphate and sodium tetraborate can be used to deposit a ceramic binder in a finished article. This ceramic binder could be fused in a subsequent heat treatment into a glass-bonded ceramic. Other inorganic solutes that could be printed include sodium chloride, ammonium nitrate, and potassium sulfate, ammonium chloride, and calcium formate.
[0065] Inorganic solutes participate in acid-base reactions. For example, sodium hydrogen phosphate solution could be printed onto powdered calcium carbonate. The acid binder etches the alkaline powder and forms calcium phosphate that recrystallizes and cements together the grains of powder. Another example is sodium silicate, which can be printed in a binder solution and can react with, for example, gypsum plaster to form calcium silicate.
[0066] In the fourth category, a solution of monomeric organic compounds can be printed through an electromechanical drop-on-demand printhead for three-dimensionally printed articles. These monomeric organic compounds generally fall into several broad classes: alcohols, esters, ethers, silanes, vinyl monomers, acrylic monomers, and methacrylate monomers.
[0067] Alcohols and esters that have been found to function well as the solvent phase, in addition to functioning as a solute in another solvent (usually water) are: methyl alcohol, ethyl alcohol, isopropanol, t-butanol, ethyl acetate, dimethyl succinate, diethyl succinate, dimethyl adipate, and ethylene glycol diacetate. These materials act as solvents for resins in the powder bed.
[0068] Resins that have been found to work in a 3-D printer are: shellac, polyvinyl pyrrolidone, polyvinyl acetate, polyvinyl alcohol, polystyrene, styrene-butadiene copolymer, and acrylonitrile-butadiene-styrene copolymer. These resins can be used in combination with any filler, or they can be used by themselves. A particularly suitable combination is 100% dimethyl succinate binder printed over a powder of 100% acrylonitrile-butadiene-styrene copolymer.
[0069] The other monomers contain active sites for polymerization, and possess mixed characteristics. The classes of polymerizable monomers are the vinyl monomers, acrylic monomers, and methacrylate monomers. A exemplary mixed vinyl-silane monomer is vinyltriisopropoxysilane. Acrylic monomers include tri(propylene glycol) diacrylate, ethylene glycol phenyl ether acrylate, and 1,6 hexanediol diacrylate. Methacrylates include 1,3 butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, butyl methacrylate, 1,6 hexanediol dimethacrylate, and di(propylene glycol) allyl ether methacrylate.
[0070] In addition, there are some proprietary monomers of unknown character that have been found to print well. These are manufactured by Sartomer Co. of Exton, Pa., with designations SR 521, SR 516, and CN 131. These materials are reactive, and when mixed with a photoinitiator, they can be solidified by applying ultraviolet radiation. A particularly suitable binder formula for this polymerizable class is 99% neopentyl glycol dimethacrylate mixed with 1% of Sartomer product # KT046 as a photoinitiator. Any of the above-listed monomers can be made to work, but this formula yields a suitable flow through the printhead and suitable reactivity. The radiation necessary to cure these materials is ultraviolet light with a wavelength of 363-378 nm and an energy density of 1 joule/cm 2 . A particularly suitable powder formula for this mixture is given in Table 1, above.
[0071] Additionally, there are organic acids and sugars: sucrose, dextrose, malic acid, and sodium citrate, and other compounds such as urea and the hydrolyzed amino acids that can be used as solutes in water solution. These compounds would bind by drying in the powder, and not have any appreciable solvent character on their own. In addition, reactive monomers, such as melamine-formaldehyde, can be printed in a liquid solution and later polymerized by heat, by an initiator, or by actinic radiation such as ultra-violet radiation.
[0072] The fifth class includes members that can be used with electromechanical printheads that are designed for printing molten wax, such as the Tektronix Phasor 340 printhead (which includes a temperature control). In this category, a room temperature solid such as wax can be used by itself or to replace water as a medium to convey the primary adhesives discussed in categories 1-4. The wax itself would serve as an adhesive to cement together powder particles. Binders formulated from these materials would be appropriate for electromechanical printheads that work at elevated temperatures. At these operating temperatures, the binder would become fluid and could then be used in the three-dimensional printing process.
[0073] Typical wax-based binder formulations would include waxes with a low melt viscosity (less than 100 centipoise) such as different grades of natural mineral, or refined waxes. Examples include but are not limited to carnauba wax beeswax, ceresine, ozokerite, montan, orlcury wax, paraffin, and microcrystalline wax. The waxes can be chemically modified to include reactive groups such as alcohols, organic acids, alcohol oxazolates, and urethane derivatives. To modify binder material properties such as melting point, melt viscosity, toughness and hardening rate, as well as to increase compatibility with added components, the waxes can be blended or compounded with resins, oils, and other polymers. Additional components include rosin, fatty acids, fatty acid salts, mono and diglycerides, mineral oils, and turpentines. Resins include polyethylene, polypropylene, polybutadiene, polyethylene oxide, polyethylene glycol, polymethyl methacrylate, poly-2-ethyl-oxazoline, polyvinylpyrrollidone, polyacrylamide, and polyvinyl alcohol.
[0074] Adhesives in members of the first class (polymer solutions) and the second class (inorganic-solutions) will often adsorb water if left exposed to ambient atmosphere. However, these adhesives will generally perform with greater reliability and efficacy if maintained in either a completely dry or wet state. By incorporating the adhesives in the liquid binder, they can thereby be maintained in a wet state and therefore exhibit the desired reliability and efficacy.
[0000] Humectant
[0075] A humectant can be included in the inventive mixture to retard evaporation of the solvent from the printed material, and to prevent drying/clogging of the printhead delivery system. Glycerol is a partcularly suitable humectant when the solvent is aqueous. Other polyhydric alcohols, including but not limited to ethylene glycol, diethylene glycol, and propylene glycol, are also known in the art to retard evaporation. Additional humectants include thiodiethanol, n-methyl pyrrolidinone, and dimethyl hydantoin.
[0000] Flowrate Enhancer
[0076] A flowrate enhancer can be included that has some humectant properties, but serves mainly to alter the hydrodynamic properties or wetting characteristics of the fluid to maximize the volume of fluid delivered by the printhead. Flowrate enhancement is thought to be a viscoelastic phenomena increasing the flow rate of the fluid, allowing thicker layers to be printed, thus allowing the final article to be built more quickly. Specific compounds that increase the flowrate of the fluid, either by reducing friction between the fluid and the walls of the jet, or by reducing the viscosity of the fluid, include ethylene glycol diacetate and potassium aluminum sulfate. Other suitable compounds for use as the flowrate enhancer can be selected from the following non-limiting list: tetraethylene glycol dimethylether, isopropyl alcohol, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, dodecyl dimethylammoniopropane sulfonate, glycerol triacetate, ethyl acetoacetate, and water-soluble polymers including polyvinyl pyrrolidone with a molecular weight of about 30,000 units, polyethylene glycol, polyacrylic acid, and sodium polyacrylate. For the ionic polymers, such as sodium polyacrylate, the increase in flow rate varies with pH. Salts that can be used to enhance flowrate include potassium sulfate, potassium aluminum sulfate, sodium hydrogen phosphate and sodium polyphosphate.
[0000] Dye
[0077] The fluid of the present invention can include a dye to provide a visual aid to the operator while building the article. The dye provides contrast between activated and unactivated powder which allows the operator to monitor the printed layers while building the article. The dye can be selected from the group including, but not limited to, naphthol blue-black and direct red. Other dyes that are compatible with the fluid can likewise be used.
[0000] Additional Ingredients in the Activating Fluid
[0078] Cosolvents can be added to an aqueous solution to alter the viscosity of a solution by altering the solvency of the liquid for the solute. Long-chain molecules in solution conform themselves either into extended chains or into coiled structures. If the solvent has a high affinity for the solute, long molecules will spread out causing the viscosity of the solution to be high. By adding a cosolvent to the solution, the polymer can be come less strongly attracted to other dissolved polymer molecules, and begin to coil into compact balls. This tends to reduce the viscosity of a polymer solution and allows more polymer to be dissolved. Cosolvents include isopropanol, ethyl alcohol, ethylene glycol monobutyl ether, butyrolactone and acetone.
[0079] Additives that control the pH of the binder, generally called buffers, can impart increased stability to the adhesive solutions and suspensions. Such materials include, but are not limited to, potassium hydroxide, ammonia, ammonium chloride, triethanolamine, sodium acetate, sodium gluconate, potassium sulfate, potassium hydrogen sulfate, sodium aluminum sulfate, and sodium tetraborate.
[0080] Wetting agents are substances that control the surface tension of a liquid. These can be used to modify the spreading of the liquid adhesive on the surfaces of the printhead mechanism. These include, but are not limited to, sodium dodecyl sulfate, sodium di-octyl sulfosuccinate, ethyl butyrate, diethylene glycol monobutyl ether, polyethylene glycol alkyl ether, and sodium p-toluene sulfonate.
[0081] Lubricants can be used to increase the rate at which liquid binder passes through the nozzles of a printhead. Depending on the materials of construction, substances such as glycerol triacetate, polyethylene oxide, polypropylene glycol, ethyl acetoacetate, diethyl succinate, and sodium polyacrylate can be used.
[0082] Additional substances can be used to promote the stability of suspensions. Stabilizers include emulsifiers such as sorbitan trioleate, polyoxyethylene mono-dodecyl ether, polyoxyethylene sorbitan mono-oleate, and protective colloids such as polyoxyethylene-co-polyoxypropylene, polyvinyl pyrrolidone, polyacrylic acid, gelatin, and acacia gum.
[0083] The equipment used in the method of the present invention is reliable, inexpensive, and easy to maintain, making it ideal for use in an office environment. The materials used in the present invention are capable of achieving much better performance in 3D Printing than those presently used in the liquid binder method. Thus, less equipment maintenance is required, and the reliability of the equipment is mcreased. Therefore, methods of the present invention can involve shorter build times and less labor than prior art methods.
[0084] Those skilled in the art will readily appreciate that all parameters listed herein are meant to be exemplary and actual parameters depend upon the specific application for which the methods and materials of the present invention are used. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the invention can be practiced otherwise than as specifically described. | A three-dimensional printing materials system and method can produce both appearance models and small numbers of functional parts in an office environment. The method can include building cross-sectional portions of a three-dimensional article, and assembling the individual cross-sectional areas in a layer-wise fashion to form a final article. The individual cross-sectional areas can be built by using an ink-jet printhead to deliver an aqueous solvent or binder to an adhesive particulate mixture, causing the particles of the mixture to adhere together, and to previous cross-sectional areas. The binder can include at least one of nonaqueous organic monomeric compound, anionically ionizable polymer, cationic polymer, polymer, waterborne colloid, or inorganic solute. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a continuously variable transmission means for use in a vehicle. The continuously variable transmission (CVT) varies transmitting speed ratios of a revolution number of a driven pulley to that of a driving pulley. More particularly, the present invention relates to a transmission means having a control means which permits a low engine RPM, even when an engine experiences a large load.
FIG. 1 shows a graph illustating a relationship between an engine torque and an engine speed (RPM) of a vehicle in which a continuously variable transmission means is mounted. Heretofore, the RPM of an engine equipped with a CVT was designed such that it assumed a value determined by the curves "a" and "b" in FIG. 1. It is preferable that an engine RPM is determined so that the amount of fuel consumption be minimized over the entire range. The curve "a" is shown in FIG. 1 determined such that the amount of fuel consumed may be minimized. On the other hand, in general, vibrations in the engine increase when the engine is at a low RPM, while experiencing a high load. This results in the occurrence of undesirable vibration in a vehicle body, and noise in a passenger compartment. Further, this vibration shortens the endurance of driving parts employed in a vehicle. It is quite difficult to determine an engine RPM especially under the condition that an engine RPM is low and an engine load is high. Hence, an engine RPM must be varied from an engine speed curve, indicated by the reference "a", to an another engine speed curve indicated by a reference "b", during the time when engine RPM is low. A point D1 on the curve "a" is a point where the curve "a" intersects with the curve "b". The curve "b" is determined independently from the minimum fuel consumption curve "a" as shown in FIG. 1. The preferable engine characteristics at a low engine RPM under a high engine load varies according to the type of engine mounting structure to a vehicle body, the vehicle body structure and the engine operating conditions. Hence, in order to obviate the above-mentioned drawbacks the engine characteristic curve at a low engine speed is determined by the curve "b", which is located at relatively higher engine RPM's than that of the curve "c". This results in a large amount of a gasoline consumption and impairs efficient operation.
SUMMARY OF THE INVENTION
The present invention was made in view of the foregoing background and to overcome the foregoing drawbacks. It is an object of this invention to provide a continuously variable transmission means which permits a low engine RPM even when a high load is applied to an engine.
To attain the above object, a continuously variable transmission according to the present invention, has a driving pulley with a fixed member and a movable member actuated by a hydraulic cylinder to form a V-shaped opening therebetween, a driven pulley with another fixed member and another movable member actuated by another hydraulic cylinder to form another V-shaped opening therebetween, and a flexible endless belt member spanning the pulleys so that different transmitting ratios can be obtained. A throttle valve controls an engine speed. A vehicle body vibration in accordance with an operating condition of the engine is detected by a vibration sensor. A storing circuit stores a predetermined basic value, and a comparator compares the detected physical quantity with the stored basic value. Finally, a compensator amends the engine speed from the compared results of the comparator and varies the transmitting ratios from the driving pulley to the driven pulley.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects, features and advantages of the present invention will become more apparent from the following description of the preferred embodiment taken in conjunction with the accompanying drawings.
FIG. 1 is a graph illustrating a relationship between an engine torque and an engine speed (RPM);
FIG. 2 is a schematic view of a vehicle in which a continuously variable transmission according to the present invention is applied;
FIG. 3 is an enlarged detailed view of a hydraulic circuit employed in the continuously variable transmission shown in FIG. 2;
FIG. 4 is a block diagram of an electronic control apparatus employed in the continuously variable transmission according to the present invention;
FIG. 5 is a block diagram showing an electronic operation employed in the continuously variable transmission according to the present invention; and
FIG. 6 is a flow chart of an electronic operation employed in continuously variable transmission according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is described in detail with reference to the accompanying drawings which illustrate different embodiments of the present invention.
FIG. 2 shows a schematic view of a vehicle in which a continuously variable transmission according to the present invention is applied.
An engine 1 generates a torque, and the torque is transmitted through a crank shaft 2 and a clutch 3 to an input shaft 5 of a continuously variable transmission (CVT) 4. The CVT 4 varies the transmitting ratios from the input shaft 5 to an output shaft 10. The continuously variable transmission 4 includes a plurality of pulleys 6, 7 and 8, 9. The pulley 6 and 7 is a driving pulley (input pulley) mounted on the driving and input shaft 5, which is driven by the engine 1. The pulley 8 and 9 is a driven pulley (output pulley) mounted on the driven and output shaft 10. The torque of the output shaft 10 is transmitted to wheels (not shown in drawings). A torque transmitting V-belt 11 extends between V-shaped peripheral portions of the pulleys 6, 7 and 8, 9. The driving pulley has a member 7 which is fixed to and rotatable with the input shaft 5, and a member 6 which is axially displaceable on and rotatable with the input shaft 5. The member 6 is designed to be axially moved by the pressure of a hydraulic cylinder 6c. When the member 6 axially moves in the direction to approach to the opposite member 7, the width defined between the members 6 and 7 can be narrowed. This results in the increase in the effective diameter of the driving pulley. In this condition, the transmitting speed ratio, (the rotating speed of the driven pulley)/(the rotating speed of the driving pulley) increases. Similarly, the driven pulley has a member 8 which is fixed to and rotatable with the driven shaft 10, and a member 9 which is axially displaceable on and rotatable with the driven shaft 10. The member 9 is designed to be axially moved by the pressure of another hydraulic cylinder 9c. When the member 9 axially moves in the direction to approach to the opposite member 8, the width defined between the members 8 and 9 can be narrowed, thereby increasing the effective diameter of the driven pulley. In order to minimize an amount of power loss consumed by an oil pump, the hydraulic pressure of the cylinder 9c is controlled to be as small as possible while keeping to the slip-free torque transfer between the driven pulley 8, 9 and the belt 11. The hydraulic pressure of the cylinder 6c of the driving pulley is controlled in order to vary the transmitting speed ratios between the driving and driven pulleys. The value of the pressure in the cylinder 6c is adapted to be smaller than that of the pressure in the cylinder 9c of the driven pulley. However, as the total square of the cylinder 6c is designed to be bigger than that of the cylinder 9c, it is possible to obtain the speed ratio which is less than one. The continuously variable transmission is supplied with a pressurized fluid in the following procedure:
An oil pump 17 driven by a motor supplies oil in a reservoir 16 to a passage 18. A regulator valve 15 controls the pressure of the fluid in a passage 19, thereby generating a line pressure P L in the passage 19. The line pressure P L is supplied through the passage 19 to the cylinder 9c of the driven pulley and to a flow control valve 24. The flow control valve 24 is a three port connection valve, and includes an inlet port 240 communicated through the passage 19 with the regulator valve 15, a drain port 242 communicated with a drain passage 25 and an outlet port 244 communicated with the cylinder 6c of the driving pulley. When the flow control valve 24 is in the first position 24A , the inlet port 240 communicates with the outlet port 244. Next, when the flow control valve 24 is in the second position 24B, there is no communication among three ports 240, 242 and 244 as shown in FIG. 2. Finally, when the flow control valve 24 is in the third position 24C, the outlet port 244 communicates with the drain port 242. The numeral 29, which is attached to a component adjacent the engine 1, designates a sensor for detecting an intake pressure in an intake pipe. Sensors 31 and 32 detect a rotating speed of each of the pulleys and are provided on the driving pulley 6, 7 and the driven pulley 8, 9, respectively. The numeral 34 designates an accelerator pedal in a passenger compartment, and the accelerator pedal 34 is connected with a throttle valve 35 mounted in an intake system. A sensor 36 detects the displaced stroke of the accelerator pedal 34. A sensor 37 for detecting either the sound in a vehicle or vibrations of a vehicle body is provided at a position over the accelerator pedal 34 in a dash panel, detects noise which occurs when the engine speed is low and the engine load is high. The output signals of the sensors 29, 31, 32 and 36, and the sensor 37 are inputted into an electronic control unit (hereinafter referred to as ECU) 40. The ECU 40 outputs the control signals to the valves 15 and 24.
Referring next to FIG. 3, there is illustrated the detailed construction of the regulator valve 15 and the flow control valve 24 which are schematically shown in FIG. 2. In this embodiment, both valves 15 and 24 are provided in the same valve body 100. The regulator valve 15 includes a valve spool 110, a Poppet shaped valve member 122 and a relief valve 130. The valve spool 110 slides in a bore 118, thereby opening or closing a port 158, which is defined between the passage 18 and a drain passage 20. The valve spool 110 includes a radially extending portion 114 and a head portion 112. Within the head portion 112, a small hole 116 is provided. There is provided a chamber 119 in a space defined between the portion 114 and the inner wall of the valve body 100. A compression coil spring 117 is located between the head portion 112 of the valve spool 110 and the inner wall of the valve body 100. The spring 117 biases the valve spool 110 toward the direction to close the port 158. The Poppet shaped valve member 122 controls the flow at a port 154 which connects a passage 152 with an oil chamber 156. A plunger 120 is fixed to the Poppet shaped valve member 122, and slides in a bore 124. A compression coil spring 126 is provided at the position between the plunger 120 and the inner wall of the valve body 100. The spring 126 biases the valve member 122 toward the direction to close the port 154. A first linear solenoid 128 is embedded around the plunger 120 in the valve body 100. An orifice 150 is provided on the passage 152, which communicates with the passage 18. The relief valve 130 comprises a check ball 132 and a spring 134 which biases the check ball 132 toward the direction to close a port 136. When the fluid pressure in the chamber 119 exceeds a predetermined value, the check ball 132 moves against the force of the spring 134. Under this condition, oil returns through the port 136 to the passage 18.
The flow control valve 24 is provided at a position between the regulator valve 15 and the hydraulic cylinder 6c of the driving pulley. The flow control valve 24 includes a valve spool 241, plungers 246 and 243, a second solenoid 249 and a third solenoid 250. The valve spool 241 controls the communication among ports 240, 242 and 244. Plungers 246 and 243 are fixed to each end of the valve spool 241, respectively. A compression spring 248 biases the plunger 246 toward the direction to open the drain port 242. A compression spring 245, which is provided at the opposite position to that of the spring 248, biases the plunger 243 toward the direction to close the drain port 242. Further, the second solenoid 249 is provided around the plunger 246 in the valve body 100. When the second solenoid 249 turns on, the second solenoid 249 pulls the plunger 246 with the electromagnetic force against the force of the spring 248. The third solenoid 250 is provided around the plunger 243 in the valve body 100. When the third solenoid 250 turns on, the third solenoid 250 pulls the plunger 243 with the electromagnetic force against the force of the spring 245.
In operation, after the engine starts, the oil pump 17 supplies the oil in the reservoir 16 to the passage 18. When the electric current fed into the first solenoid 128 increases, the first solenoid 128 pulls the plunger 120 against the force of the spring 126. Hence, the top end of the valve member 122 lifts up, and the opening area of the port 154 increases. As the chamber 156 is communicated through the small hole 116 with the drain passage 20, the amount of the drained oil also increases when the opening area of the port 154 increases. Under this condition, the value of the oil pressure in the chamber 119 decreases. When the force biasing the valve spool 110 toward the direction to close the port 158 becomes smaller than that of the force biasing the valve spool 110 toward the direction to open the port 158, in FIG. 3, the valve spool 110 upwardly moves to open the port 158. As a result, the line pressure P L of the passage 18 decreases.
When the electric current fed into the second and third solenoids 249 and 250 is not zero, the valve spool 241 of the flow control valve 24 positions the neutral point as shown in FIG. 3 (i.e., the second position 24B in FIG. 2). Under this condition, there exists on oil flow communication among ports 240, 242 and 244. When only the second solenoid 249 is supplied with electric current, the second solenoid 249 pulls the plunger 246 against the force of the spring 248. The opening square of the inlet port 240 increases in accordance with the increase of the electric current. Hence, the volume of the oil supplied to the cylinder 6c of the driving pulley increases. This results in the increase of the transmitting speed ratios. Contrary to this, when only the third solenoid 250 is supplied with electric current, the third solenoid 250 pulls the plunger 243 against the force of the spring 245. Under this condition, the opening square of the drain port 242 increases, and this results in an increase of the volume of oil drained from the cylinder 6c of the driving pulley. Hence, the transmitting speed ratio decreases. Thus, the speed ratios are controlled by varying the volume of oil supplied to or drained from the cylinder 6c of the driving pulley.
The ECU 40 controls the regulator valve 15 and the flow control valve 24 by the signals detected by the different types of sensors. FIG. 4 shows that the ECU 40 functions as a digital computer and has a central processing unit (hereinafter referred to as CPU) 41 which carries out the arithmetic and logic processing means, a random-access memory (hereinafter referred to as RAM) 42 which temporarily stores the calculated data of the CPU 41, a read-only memory (hereinafter referred to as ROM) 43 which stores a predetermined control program and arithmetic constants therein, a digital-analog converter (hereinafter referred to as D/A) 44, an inter-face (hereinafter referred to as I/F) 45, and an analog-digital converter (hereinafter referred to as A/D) 46.
The I/F 45 receives the output signals of the sensors 31 and 32 for detecting the rotating speed of the driving pulley and the driven pulley, respectively. The A/D 46 receives the output signals of the sensor 29 which detects an intake pressure in the intake pipe, the sensor 36 which detects the displaced stroke of the accelerator pedal 34 and a band-pass filter 52. The band-pass filter 52 receives an analog signal from the microphone 37, and passes the frequency (2˜40Hz) occurred at the intermittent fuel combustion at a low engine speed and a higher harmonic frequency thereof. The CPU 41, a microprocessor, then compares the received information, through a bus 47, against any stored information, and issues an output to the D/A 44 which then subsequently outputs the appropriate instructions to the regulator valve 15 and the flow control valve 24.
FIG. 5 illustrates a block diagram which shows an electronic operation employed in the CVT according to the present invention. In a block 57, the displaced stroke signal Xacc of the accelerator pedal 34 is detected, and the required horse power PS corresponding to the stroke Xacc is calculated. The required horse power PS is determined in such a way as the horse power is a function as to the accelerator pedal stroke Xacc. The program proceeds to a block 58. In the block 58, a desired engine speed RPMin' is calculated from the required horse power PS. The desired engine speed RPMin' is defined to be a curved line which is substantially the same as the curves "a" and "c" shown in FIG. 1.
The output of the sensor 37 is inputted through the filter 52 to a block 61. The filter 52 passes the basic frequency of the engine, which is the number of combination strokes per second, as well as a higher harmonic frequency which corresponds to the basic frequency either multiplied or divided by an integer. Thus, a signal V corresponding to noise in a passenger compartment is inputted to the block 61. In a block 62, a basic sound signal Vsh, which is a function of to the engine speed RPMin, is calculated. when the engine speed RPMin increases, the basic sound signal Vsh is inclined to decrease. When the engine speed RPMe (=RPMin) decreases, the noise level in the passenger compartment inversely increases. The basic sound signal Vsh is defined to be an appropriate value which is experimentally determined. The output Vsh of the block 62 is inputted into the block 61. In the block 61, a comparator compares the actual sound signal V supplied through the filter 52 with the basic sound signal Vsh. Next, the program proceeds to a block 63. In the block 63, the compensated engine speed ΔRPM is calculated from the output of the block 61 from the following procedures. When the actual sound signal V is equal to or more than the basic sound signal Vsh, the compensated engine speed ΔRPM is determined to have a value calculated by the formula (ΔRPM+K1). Contrary to this, when the sound-signal V is lower than the basic actual sound signal Vsh, the compensated engine speed ΔRPM is determined to have a value calculated by the formula (ΔRPM-K2). Hence, K1 and K2 are functions of the engine speed RPMin, and both of them are positive numbers. The compensated engine speed ΔRPM is selected to be equal to or more than zero. Next, the program proceeds to the block 64. In the block 64, (RPMin'+ΔRPM) is substituted a desired engine speed for RPMin*. Next, the value (RPM*-RPMin) is selected and, this value (RPM*-RPMin) is inputted into the flow control valve 24. When the undesirable noise in the passenger compartment increases, the value (V-Vsh) becomes equal to or more than zero, and the compensated engine speed ΔRPM increases. As a results, the engine speed RPMe (=RPMin) increases, resulting in the decrease of the undesirable noise. When the engine rotates at a higher speed than a predetermined minimum engine speed, the value (V-Vsh) becomes less than zero, resulting in the decrease of the compensated engine speed ΔRPM. Hence, the engine speed RPMe decreases. Thus, the engine rotates at the minimum engine speed within the limited zone where the level of the undesirable noise in a passenger compartment is acceptable. As the compensated engine speed RPM is selected to be equal to or more than zero, the desired engine speed RPMin* becomes equal to or more than RPMin', thereby limiting the lower limit of RPMin. The undesirable noise in a passenger compartment impairs a passenger's comfort and causes passenger fatigue. It is possible to obtain the minimum engine speed in view of the longitudinal acceleration of a vehicle without undesirable noise in the passenger compartment. In this case, sensors for detecting a vibration and an acceleration of a vehicle may be provided instead of a sound sensor. A displacement sensor for detecting the vibration of an engine and a transmission may be provided in order to obviate the bad influence generated by the intermittent combustion of an engine. The output signal of the displacement sensor is compared with the basic sound signal Vsh. The displacement sensor may be replaced by a sensor for detecting a load applied to a mounting structure of an engine or a transmission, or for detecting a strain of a mounting structure of an engine or a transmission. The line pressure P L is controlled by following manner: In FIG. 5, block 70, an engine torque Te is calculated from the relation between an engine torque and a pressure in an intake pipe. The pressure in an intake pipe is detected by the intake pressure sensor 29. The program proceeds to a block 71. In the block 71, the desired line pressure P L * is calculated by following equation:
P.sub.L *=K3·Te (RPMout/RPMin)
where, K3 is constant, and Te is an engine torque.
Hence, the desired line pressure P L * is in proportion to an engine torque. This signal of the desired line pressure (P L *) is supplied to the regulator valve 15.
FIG. 6 shows a flow chart of an electronic operation employed in the transmissions according to the present invention. In a step 75, the input data is read, such as the displaced stroke Xacc of an accelerator pedal 34, the rotating speed RPMin of the driving pulley, the rotating speed RPMout of the driven pulley, the intake pressure P in the intake pipe and the undesirable noise V in a passenger compartment. The program proceeds to a step 76. In the step 76, the required horse power PS, the desired engine speed RPMin', the basic sound signal Vsh and the engine torque are calculated form the maps Xacc-PS (shown in the block 57 in FIG. 5), PS-RPMin' (shown in the block 58 in FIG. 5), RPMin-Vsh (shown in the block 62 in FIG. 5), and P-Te (shown in the block 70 in FIG. 5), respectively. The program proceeds to a step 77. In the step 77, it is determined whether the level of the actually detected sound signal V is equal to or more than that of the basic sound signal Vsh. If the level of the actual sound signal V is equal to or more than that of the basic sound signal Vsh, the program proceeds to a step 78. Contrary to this, if the level of the signal V is less than the level of the basic signal Vsh, The program proceeds to a step 79. In the step 78, the compensated engine speed ΔRPM is replaced by the value (ΔRPM+K1). In the step 79, the compensated engine speed ΔRPM is replaced by the value (ΔRPM-K2). The compensated engine speed ΔRPM is selected to be equal to or more than zero. Next, the program proceeds to a step 80. In the step 80, the value, (RPMin'+ΔRPM), is substituted for the desired engine speed RPMin*. As a result of te program in the step 80, the engine speed is controlled to be equal to the desired engine speed RPMin*. Finally, the program proceeds to a step 81. In the step 81, the line pressure P L is calculated from the value of an engine torque Te and the ratio of (RPMout/RPMin).
Thus, the engine speed is controlled to be as small as possible while keeping the undesirable noise in the passenger compartment to an acceptable level.
While the present invention has been described in its preferred embodiment, it is to be understood that the invention is not limited thereto, and may be otherwise embodied within the scope of the following claims. | A continuously variable transmission means for vehicles which enables the engine speed under a high torque to be as small as possible, while ameliorating undesirable noise in a passenger compartment. The transmission means includes a device for detecting a noise and a comparator device for comparing the actual booming noise with a predetermined allowable noise level. | 1 |
TECHNICAL FIELD
[0001] This disclosure is directed to an architectural mesh panel, and more particularly to a framed architectural mesh panel with an integrated tensioning system.
BACKGROUND OF THE DISCLOSURE
[0002] Architectural mesh panels add an aesthetic look to a building façade while also adding additional benefits such as security, fall protection, and ventilation. Large mesh panels such as those spanning the heights of building can be used, for example, on parking garages in order to improve the appearance thereof. These large mesh panels are typically manufactured from a flexible mesh, such as that utilized in conveyor belts, and require a tensioning system to apply pre-tension to the mesh panel in order to keep the mesh taught so that it can withstand large wind loads. An example of such an architectural mesh system is shown in U.S. Pat. No. 7,779,888 to Cambridge International, Inc., the contents of which are hereby incorporated by reference.
[0003] In contrast, smaller framed mesh panels of rigid architectural mesh are typically used as wall panels, ceiling panels, room dividers, handrail in-fill panels, elevator wall panels, and the like. An example of an architectural mesh used in a smaller rigid panel is shown in U.S. Pat. No. D483,953 to Cambridge International, Inc., the contents of which are hereby incorporated by reference. The rigid nature required for these panels prevents a flexible mesh from being utilized in these applications because the typical mesh tensioning system is too bulky to fit inside of the conventional framing components.
[0004] Accordingly, there exists a need in the marketplace for a mesh panel system with a self-contained tensioning system integral to a frame such that the tension required to utilize flexible mesh can be applied. The advantages of utilizing a flexible mesh in a framed mesh panel include a greater variety of available mesh patterns and appearances, lower costs, lighter weight, increased ventilation, and light transparency.
SUMMARY
[0005] A framed architectural mesh panel system includes a mesh panel, a frame assembly, and a tensioning system integrated within the frame assembly.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0006] These and other objects, features, and advantages of the invention will become more readily apparent to those skilled in the art upon reading the following detailed description, in conjunction with the appended drawings in which:
[0007] FIG. 1 is a front view of an architectural mesh framing system according to an embodiment of the disclosure.
[0008] FIG. 2 is a perspective view of the architectural mesh framing system mounted within a support structure.
[0009] FIG. 3 is an enlarged view of the architectural mesh within the framing system.
[0010] FIG. 4 is a schematic illustration of a tension bar in the architectural mesh framing system.
[0011] FIGS. 5A and 5B are illustrations of attachment clips used in the architectural mesh framing system.
[0012] FIG. 6 is a schematic illustration of tensioning the architectural mesh framing system.
DETAILED DESCRIPTION
[0013] This disclosure is directed to a framed architectural mesh panel system 10 , as shown generally in FIGS. 1 - 3 . The system 10 includes a mesh panel 12 , a frame assembly 14 , a tensioning system 16 , and attachment clips 18 . The frame assembly 14 comprises a plurality of hollow structural steel tubing 20 with a slit 22 cut on the inner periphery in order to receive the edge of the mesh panel 12 . Sections of the tubing 20 are cut to allow insertion of the mesh panel 12 , mounting of components of the tensioning system 16 and to allow assembly of the steel tubing 20 to form a frame 24 having the desired size and configuration. The frame tubing 20 is typically stainless steel but it could of course be fabricated from other materials, and powder coated, if desired. Attachment clips 18 are welded onto the frame 24 for securing the frame 24 to the intended mounting surface or structure 26 .
[0014] The architectural mesh panel 12 , as shown best in FIG. 3 , is woven to a predetermined width and has the uppermost and lower edges defined by a plurality of loops 28 . A single helically-wound spiral wire 30 is associated with two connector crimp rods 32 a, 32 b positioned to be sequentially adjacent in the vertical direction of the mesh panel 12 and to define a spiral unit. Horizontal crimp rods 32 a, 32 b are inserted into the woven spirals 30 to join the individual spirals together into a panel 12 . The terminal ends of the crimp rods are welded to make the assembly permanent. The mesh 12 can be woven with a variety of different wire sizes, pitches, and directions to produce a large variety of patterns. Further details of possible woven mesh patterns are described, for example, in U.S. Pat. No. 8,006,739 to Cambridge International, Inc., the contents of which are hereby incorporated by reference. U.S. Pat. No. 8,006,739 describes an architectural mesh with a combination of various mesh patterns, however, it will be apparent to one skilled in the art that a single mesh pattern or any combination thereof could of course be utilized in the framing system disclosed herein. The mesh material is typically stainless steel but can be manufactured with a number of different metallic alloys for different appearances.
[0015] With reference to FIG. 4 , tensioning system 16 is used to keep the mesh panel taught and straight. The tensioning system 16 includes a plurality of flat tension bar sections 34 with holes 36 to match the pattern of loops on the connection spiral 30 . These sections are welded to the backing bar 38 giving the assembly the strength and rigidity to withstand the tension forces exerted on the mesh panel 12 . Tension nuts 40 are welded at different sections along the backing bar 38 . The number and spacing of these nuts are determined by the size of the mesh panel 12 .
[0016] The connecting spirals 30 of the mesh panel are rotated onto and through the holes 36 in the tension bars 34 , thereby joining the mesh panel 12 to the tensioning system 16 . The mesh panel 12 and tension bars 34 are inserted into the frame assembly 14 and the frame 24 is welded together. Screws 42 are inserted into fittings 44 on the top and bottom of the frame 24 and threaded into the tension nuts 40 on the tension bar assembly 34 , as best shown in FIG. 6 . The number and size of the fittings 44 are determined by the size of the frame 14 .
[0017] Referring also to FIGS. 5A and 5B , the framed architectural mesh panel 10 can be secured onto a mounting surface or structure 26 with a variety of attachment clips 18 , tabs, or fasteners. These clips can be designed to match existing clips or environment. The attachments can be mounted along the periphery of the frame edges or along the back side if the frame is mounted flush on a wall or ceiling. The size and number of attachment clips 18 is determined by the weight of the frame assembly and the availability of existing clips and structure.
[0018] The framed architectural mesh panel 10 is tensioned as shown in FIG. 6 by tightening the screws 42 in the fittings 44 located along either end of the frame 24 . The mesh panel 12 , connected to the tension bar 34 , is drawn in opposite directions towards the top and bottom of the frame 24 . This tension removes slack from the mesh panel 12 keeping the mesh spirals 30 in crimp and results in a uniform appearance.
[0019] While the present invention has been described with respect to a particular embodiment of the present disclosure, this is by way of illustration for purposes of disclosure rather than to confine the invention to any specific arrangement as there are various alterations, changes, deviations, eliminations, substitutions, omissions and departures which may be made in the particular embodiment shown and described without departing from the scope of the claims. | A framed architectural mesh panel system including a mesh panel; a frame assembly; and a tensioning system; wherein the tensioning system is integrated within the frame assembly. | 4 |
BACKGROUND
The invention relates to a board for ironing garments, namely pants, skirts, blouses, jackets, dresses, including the sleeves, that is, the whole garment in its entirety, to allow garments to be ironed perfectly in the least accessible areas. The inventive board has therefore been created for the purpose of ironing garments and could be associated with an ironing table, or larger ironing board, so that the two become one, and this would allow it to be used in all manner of ways depending on the difficulties encountered when ironing such clothing or garments.
Traditionally, there was the large ironing board which is composed of a fairly broad (about 30 to 45 centimeters) board approximately 120 centimeters long placed and fixed on long folding legs which, when placed on the high ground, stand approximately 90 to 110 centimeters high (depending on the height to which the ironing board is adjusted), and forming a large X. Said ironing board does not allow the garments to be ironed in the least accessible areas without creasing, that is to say does not allow pants, for example, to be slipped fully over the board as the legs and width of said board prevent this.
Likewise, there was the smaller sleeve board which allowed just a small bit of the sleeves of the garments to be ironed, whereas the inventive board allows the ironing of garments, and also, as compared with the sleeve board, allows the entire length of the sleeves to be ironed by the sleeves being slipped fully over the board, because it is longer than the former sleeve board.
BRIEF SUMMARY OF THE INVENTION
The ironing board according to the invention is therefore intended for ironing garments in their entirety, and in the least accessible areas, and comprises a long narrow board under which is fixed a metal support/base that folds out sideways. Under the board there are two support legs in the shape of a horizontal U, articulated at their horizontal upper arms so that they can be folded out flat on either side of the board, and means for connecting the lower horizontal arms of the two legs together so that they are further apart than the spacing between the two upper arms, to ensure that the two legs remain stable in the erected position. The legs may be of unequal height and length to allow the ironing board to be placed in a horizontally offset position with respect to the surface of a larger board to which it is attached, the lower arms of the support legs being slipped into holding means beneath the larger ironing board. Articulations between the upper arms and a larger board may consist of grooves in the arms held in saddle clips fixed under the larger board and thus holding the arms axially in place. The lower arms of the legs are longer than the upper arms. The board has connecting means namely pivoting means fixed under the larger ironing board in such a way that the board can be folded under the larger ironing board. The board is mounted so that it can pivot about a vertical axis on the horizontal upper arms so as to be able to free up the working area of the larger ironing board.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention will be made clear with reference to the following drawings of various embodiments of the invention, as follows:
FIGS. 1A, 1B and 1C are edge, top and bottom views, respectively, of a first embodiment of the ironing board of the present invention.
FIG. 2 illustrates the assembled support/base for the ironing board of the present invention.
FIG. 3 is a partially-exploded, dis-assembled view of the support/base of FIG. 2.
FIG. 4 is a bottom view showing the support/base in partially-exploded condition.
FIG. 5 is a top view similar to FIG. 4.
FIG. 6 is a bottom view showing the support/base in fully assembled condition.
FIG. 7 is an end view of the inventive board with assembled support/base from the left end as shown in FIG. 9.
FIG. 8 is a side view of a further embodiment of a fully assembled board and support/base of the present invention.
FIG. 9 is a top/side view of the embodiment of FIG. 8.
FIG. 10 illustrates an assembled second embodiment of the support/base for an ironing board of the present invention.
FIG. 11 is a dis-assembled view of the embodiment of FIG. 10.
FIG. 12 is a bottom view of an ironing board of the present invention fitted with the support/base of FIGS. 10 and 11, shown in partially assembled form.
FIG. 13 is a top view of the ironing board of FIG. 12, fitted with the support/base of FIGS. 10 and 11, shown in partially assembled form.
FIG. 14 is a bottom view of an ironing board of the present invention fitted with the support/base of FIGS. 10 and 11, shown in fully assembled form.
FIG. 15 is an end view of the inventive board with assembled support/base from the left end as shown in FIGS. 14, 16 and 17.
FIG. 16 is a side view of the embodiment of a fully assembled board and support/base of the present invention of FIGS. 14, 15 and 17.
FIG. 17 is a top/side view of the embodiment of FIG. 16.
FIG. 18 is a view of an assembled third embodiment of the support/base for an ironing board of the present invention.
FIG. 19 is a dis-assembled view of the embodiment of FIG. 18.
FIG. 20 is a bottom view of an ironing board of the present invention fitted with the support/base of FIGS. 18 and 19, shown in partially assembled form.
FIG. 21 is a top view of an ironing board of FIG. 20 fitted with the support/base of FIGS. 18 and 19, shown in partially assembled form.
FIG. 22 is a bottom view of an ironing board of the present invention fitted with the support/base of FIGS. 18 and 19, shown in fully assembled form.
FIG. 23 is an end view of the inventive board with assembled support/base from the left end as shown in FIGS. 22, 24 and 25.
FIG. 24 is a side view of the fully assembled board and support/base of the present invention as shown in FIGS. 22, 23 and 25.
FIG. 25 is a top/side view of the embodiment of FIG. 24.
FIG. 26 is a view of an assembled fourth embodiment of the support/base for an ironing board of the present invention.
FIG. 27 is a dis-assembled view of the embodiment of FIG. 26.
FIG. 28 is a bottom view of an ironing board of the present invention fitted with the support/base of FIGS. 26 and 27, shown in partially assembled form.
FIG. 29 is a top view of an ironing board of FIG. 28 fitted with the support/base of FIGS. 26 and 27, shown in partially assembled form.
FIG. 30 is a bottom view of an ironing board of FIGS. 28 and 29 fitted with the support/base of FIGS. 26 and 27, shown in fully assembled form.
FIG. 31 is an end view of the inventive board with assembled support/base from the left end as shown in FIGS. 30, 32 and 33.
FIG. 32 is a side view of the fully assembled board and support/base of the present invention as shown in FIGS. 30, 31 and 33.
FIG. 33 is a top/side view of the embodiment of FIG. 32.
FIG. 34 is a dis-assembled view of the embodiment of FIG. 35.
FIG. 35 is a view of an assembled fifth embodiment of the support/base for an ironing board of the present invention.
FIG. 36 is a dis-assembled view of the embodiment of FIG. 37.
FIG. 37 is a view of an assembled sixth embodiment of the support/base for an ironing board of the present invention.
FIG. 38 is a dis-assembled view of the embodiment of FIG. 39.
FIG. 39 is a view of an assembled seventh embodiment of the support/base for an ironing board of the present invention.
FIG. 40 is a dis-assembled view of the embodiment of FIG. 41.
FIGS. 40A and 40B show the complementary structures 62 and 61, respectively, viewed from lines XL in FIG. 40.
FIG. 41 is a view of an assembled eighth embodiment of the support/base for an ironing board of the present invention.
FIG. 42 is an edge, exploded view of a two-piece solid board according to the present invention.
FIG. 43 is a top, exploded view of the board of FIG. 42.
FIGS. 43A and 43B are end views of the respective portions of the board of FIG. 43 taken in the directions shown on line XLIII in FIG. 43.
FIG. 44 is a side view of the assembled board of FIGS. 42 and 43 also including support/base structure.
FIGS. 45, 46, 46A, 46B and 47 illustrate a mesh ironing board otherwise similar to that illustrated in FIGS. 42, 43, 43A, 43B and 44.
FIG. 48 shows an exploded view of support/base structure useful for the boards illustrated in FIGS. 42-47.
FIG. 49 illustrates an exploded view of another support/base structure useful like the structure illustrated in FIG. 48.
FIG. 50 illustrates an exploded view of still another support/base structure useful like the structure illustrated in FIG. 48.
FIG. 51 illustrates an exploded view of still another support/base structure useful like the structure illustrated in FIG. 48.
FIG. 52 shows a bottom view of an ironing board of the present invention illustrating the location of attachment fixtures for use with a ironing board cover.
FIG. 53 shows an end view of a board like that shown in FIG. 52, illustrating the location of fixtures on the bottom of the board for attachment of support/base structure.
FIG. 54 is another view similar to that shown in FIG. 53.
FIG. 55 is a bottom view of a board like that shown in FIG. 52 overlying the bottom view of a flexible ironing board cover.
FIG. 56 is a bottom view similar to that shown in FIG. 55, but with peripheral loops on the ironing board cover hooked on the fixtures on the bottom surface of the board.
FIG. 57 is a bottom view of a mesh ironing board according to the present invention showing the location of support/base structure and fixtures therefor.
FIGS. 58 and 59 show end views of a board like that illustrated in FIG. 57, additionally showing two embodiments of fixtures for fastening support/base structure to the mesh board.
FIG. 60 shows a bottom view of an ironing board of the present invention overlying another form of ironing board cover.
FIG. 61 shows a bottom view of an ironing board with cover similar to that shown in FIG. 60, but with the tie fasteners of the cover tied behind the bottom surface of the board.
FIG. 62 shows a bottom view of another form of ironing board in accordance with the present invention.
FIGS. 63, 64, 65 and 66 are views of the board of FIGS. 62 corresponding to the views of FIGS. 53-56.
FIG. 67 shows another form of mesh ironing board in accordance with the present invention similar to the board shown in FIG. 62.
FIGS. 68. 69, 70 and 71 are views of the board of FIGS. 67 corresponding to the views of FIGS. 58-61.
FIG. 72 shows a bottom view of another form of ironing board in accordance with the present invention.
FIGS. 73, 74, 75 and 76 are views of the board of FIG. 72 corresponding to the views of FIGS. 53-56.
FIG. 77 shows a bottom view of another form of mesh ironing board in accordance with the present invention similar to the board shown in FIG. 57.
FIGS. 78, 79, 80 and 81 are views of the board of FIG. 77 corresponding to the views of FIGS. 58-61.
FIG. 82 shows a bottom view of another form of ironing board in accordance with the present invention.
FIGS. 83, 84, 85 and 86 are views of the board of FIG. 82 corresponding to the views of FIGS. 53-56.
FIG. 87 is a bottom view of another form of mesh ironing board according to the present invention showing the location of support/base structure and fixtures therefor as in FIG. 57.
FIGS. 88, 89, 90 and 91 are views of the board like those illustrated in FIGS. 58-61.
FIG. 92 shows a top view of an ironing board of the present invention including a pivot unit permitting angular movement of the board in a plane corresponding to the plane of the board and about an axis perpendicular to the plane of the board.
FIG. 93A and FIG. 93B each show, in exploded view, a dis-assembled partially U-shaped leg for a support/base for the board of FIG. 92 and FIGS. 94-97.
FIG. 94 shows a bottom view of the board of FIG. 92 having U-shaped portions of support legs connected to a base portion of a pivot unit mounted on the bottom surface of the board.
FIG. 94B shows a bottom view of the bottom portion of the pivot unit.
FIG. 95 shows a side view of the pivotal board of FIG. 92 mounted on a larger ironing board or table.
FIG. 96 is an end view from the left end of the board portions of FIG. 95.
FIG. 97A is a side edge view of the bottom portion of the pivot unit also illustrated in FIG. 94A.
FIG. 97B is a side edge view from a similar point of view as FIG. 97A, but of the top portion of the pivot unit which fits together with the bottom portion shown in FIG. 97A in the manner shown in broken lines in FIGS. 95 and 96.
FIGS. 98 and 99 show edge and top exploded views of a two-piece board otherwise similar to that shown in FIG. 92.
FIGS. 99A and 99B show end views of each portion of the board of FIG. 99 taken along lines ICA and ICB, respectively.
FIG. 100A shows a side view of a pivot unit like that shown in FIG. 97A.
FIG. 100B shows a side view of a top portion of a pivot unit like that shown in FIG. 97B.
FIG. 100C shows a bottom view of a pivot unit like that shown in FIG. 94A.
FIG. 101 shows a bottom view of the board of FIGS. 98 and 99 having the bottom portion of the pivot unit installed therein including partially U-shaped leg portions attached to the bottom of the pivot unit.
FIG. 102 shows two partially U-shaped leg portions for use in conjunction with the base of a pivot unit.
FIG. 103 shows a side view of the assembled board of FIGS. 98-102 attached to a larger ironing board or table.
FIG. 104 is a bottom view of the left end portion of the larger ironing board or table of FIG. 103, showing the attachment system by which a smaller board is attached to the larger board.
FIG. 105 is an end view of the board portions of FIG. 103.
DETAILED DESCRIPTION OF THE INVENTION
The ironing board of the present invention comprises a flat board portion as illustrated, for example, in FIGS. 1A and 1B, wherein the board has a length of approximately 120 centimeters, and a thickness as illustrated in FIG. 1A of 1.5 to 2 centimeters. As shown in FIG. 1B, the width of the board tapers from a width of about 22 centimeters at the widest point at the left end, to a width of about 9 centimeters near the right end. These board dimensions should accommodate most pants which may average in length about 110 to about 115 centimeters, while also accommodating not only smaller youth sizes, but also much longer sizes for tall individuals. The ironing board portion of the structure may be made from solid material such as chipboard, i.e., wood/glue composite material. Other embodiments of the board may be formed from a metal mesh surface supported by metal supporting structure, as discussed below in connection with FIGS. 57-59.
FIG. 1C is a bottom view of the board shown in FIG. 1B, and in FIG. 1C the location of the support/base structure and the locations ± of the connecting means which connect the support/base to the bottom of the board are also shown.
A first embodiment of the support/base structure of the present invention is shown, fully assembled, in FIG. 2. FIG. 3 illustrates the parts of the support/base structure of FIG. 2, but in FIG. 3, those parts are illustrated in partially-exploded form ready for assembly. Those parts comprise two U-shaped or horseshoe-shaped lengths of tubing, which may be made of steel or copper metallic tubing about 2.40 centimeters in diameter. Each leg of each U-shaped structure has a length of approximately 90 centimeters and each of the structures is about 18 to 20 centimeters in width near the U-shaped base portion of the member. Near the free ends of the legs 32 the legs are approximately 18 to 21.5 centimeters apart. Spacer bars 33 are about 17 to 20 centimeters in length and are assembled between the ends of the legs 32 near the U-shaped bends, as shown in FIG. 2, and a third spacer 33 is assembled between the adjacent legs of the two U-shaped elements.
Finally, another U-shaped or horseshoe-shaped element 34 shown at the right side of FIGS. 2 and 3 connects the adjacent legs of the longer U-shaped elements. As shown in FIG. 3, for example, the ends of the legs of U-shaped element 34 may fit inside the adjacent tubular legs 32 of the longer U-shaped elements 31. The main portions of the short horseshoe 34 form a U-shape about 20 centimeters in depth from its open end toward its closed curved end, and each of the legs of that U-shaped structure may also include about 10 centimeters in length of smaller diameter tubing capable of fitting inside the ends of legs 32 of the adjacent longer U-shaped elements of the support/base structure of the present invention.
Assembly of the ironing board with support/base of the present invention can be seen with respect to FIGS. 2, 3 and 4-6. First taking the long, U-shaped leg pieces 31, 32 as illustrated in FIG. 3, a short straight connecting bar 33 is then connected between adjacent legs 32 adjacent U-shaped base portions 31 as illustrated in FIG. 2. This bar 33 can be connected to each of the legs 32 with screws or other fasteners and should be located about 20 centimeters from the line tangent to the bottom of each of the U-shaped portions. Thereafter, two additional short connecting bars 33 are connected between the legs 32 of each U-shaped base portion 31, as also shown in FIG. 2 and again in FIG. 4.
With the basic support/base structure thus assembled, the two lower legs of the pair of now-connected base portions 31 are placed on the underside of the board in the position shown in FIG. 4, keeping those adjacent legs parallel and about 10 centimeters apart with the end fittings 33 about 28 centimeters from the right end of the under side of the board. The fittings or fasteners used to connect legs 32 to the bottom of the board may be saddle-like clips which span over the circumference of legs 32 and are attached, by screws or the like, at each end to the bottom of the board. Once the pair of U-shaped base portions are thus connected to the bottom of the board, the right ends of the free legs 32 are then connected by insertion of the smaller diameter ends of smaller U-shaped horseshoe 34 therein as illustrated in FIG. 2 and again in FIG. 6. FIG. 5 is a top view of the same elements shown in FIG. 4, and FIG. 6 is a bottom view like FIG. 4 but wherein the short horseshoe 34 has been inserted in the free ends of legs 32 thus completing assembly of the support/base structure with the board.
A second embodiment of the advantageous support/base structure of the present invention is shown in FIGS. 10 and 11, and shown being assembled with the board in FIGS. 12-17. In this version, as illustrated in FIG. 11, the support/base comprises two long U-shaped base elements 31 each having legs 32. Base portions 31 are formed of steel or copper metallic tubing about 2.40 centimeters in diameter with each leg being about 90 centimeters long and the legs of each base portion being spaced apart 18 to 20 centimeters at their left, U-shaped ends and about 18 to 21.50 centimeters at their open, right ends.
This embodiment of the support/base structure also includes a third U-shaped element 36 formed of steel or copper metallic tubing having a larger inside diameter than the outside diameter of legs 32 of base portions 31. The long leg portions 37 of element 36 are about 90 centimeters in length and are spaced apart about 17 to 20 centimeters. Legs 37 are also connected by short connecting bars 33. One of the legs 32 of each of the base portions 31 also includes annular grooves 38. When these grooved legs are placed on the back side of an ironing board as illustrated in FIG. 12, in parallel relationship about 10 centimeters apart, with their right ends about 28 centimeters from the right end of the board, saddle clips or other suitable fasteners can be placed over the annular groove recessed portion thereof and screwed into the bottom of the board thus affixing legs 32 of base portions 31 to the bottom of the board, as illustrated in FIG. 12. The top view of the partially assembled board as shown in FIG. 12 is illustrated in FIG. 13.
FIG. 14 shows the board of FIGS. 12 and 13 now having the third tubular, U-shaped element slipped over the free ends of legs 32 opposite the legs attached to the back of the board, so that the length of legs 37 of tubular element 36 extends over substantially the length of leg 32 of each of the base portions 31, thus providing the assembled support/base structure stability.
FIG. 15 shows an end view of the assembled board with support/base as shown in FIG. 14, but standing upright on its support base, and viewed from the left end as oriented in FIG. 14. FIGS. 16 and 17 show a side view and a top/side view, respectively, of the assembled board with support/base as illustrated in FIGS. 14 and 15, standing upright on its base as in FIG. 15.
Another embodiment of the support/base structure of the present invention is illustrated in FIGS. 7-9 wherein the U-shaped base portions are formed like those illustrated in FIG. 3, without any cross braces 33 as shown in FIG. 2, and a third U-shaped tubular member is shown slipped over the free ends of legs 32 providing stability to the assembled support/base structure as in the embodiment illustrated in FIGS. 10-17. In the embodiment illustrated in FIG. 9, the tubular U-shaped member 36 has a single cross brace 33 near the free ends of legs 37 of tubular member 36.
A third embodiment of the support/base structure is illustrated in FIGS. 18 and 19, and shown assembled with a board of the present invention in FIGS. 20-25. This embodiment includes long, U-shaped base portions 31 one leg 32 of which includes circumferential grooves 38, shown in FIG. 19, like the structure shown and described in conjunction with FIG. 11. Additionally, the opposite leg 32' of each U-shaped base portion is somewhat longer than the other leg portion 32. In this embodiment, the third element of the base portion comprises a pair of tubular bars 39 having inside diameter greater than the outside diameter of long legs 32', and tubular bars 39 are arranged parallel to each other and connected by a plurality of connecting bars 33 forming a ladder-like rectilinear structure 40. When this structure 40 is assembled over the free ends of longer legs 32', the free ends of those longer legs 32' may extend through tubular legs 39 of rectilinear portion 40, as illustrated in FIG. 18.
As illustrated in FIGS. 20 and 21, legs 32 having annular grooves or recesses 38 therein are connected to the back surface of a board in the same way in which the legs illustrated in FIGS. 11-13 were connected. This is shown in FIGS. 20 and 21. Then, assembly of the support/base structure is completed by slipping the tubular legs 39 of rectilinear frame 40 over the free end of legs 32', as illustrated in FIG. 22. This assembled structure is also shown in FIGS. 23, 24 and 25 in views which correspond to the views of FIGS. 15, 16 and 17, respectively.
In this embodiment, the dimensions of the base portions 31 are similar to the dimensions of those portions as described in the earlier embodiments. Rectilinear structure 40 comprises two tubular side rails 39 of diameter larger than the outside diameter of legs 32' and having a length of about 50 centimeters. The width of structure 40 is about 20 to 24.8 centimeters, the tubular legs 39 being connected by two or more connecting bars 33.
A fourth embodiment of the support/base for an ironing board of the present invention is illustrated in FIG. 26, and the same embodiment is illustrated in a dis-assembled view in FIG. 27. This embodiment includes base portions 31 like those illustrated and discussed with respect to the embodiment of FIGS. 18-25, but includes a rectilinear frame 41 which is structurally different from rectilinear frame 40 in the embodiment of FIGS. 18-25. As illustrated in FIG. 27, frame 41 comprises two end cross members 42, one of which is shown in end or edge view 42'. Cross members 42 are connected by a longitudinal handle 43 joining cross pieces 42 as shown in edge view at 43'. End or cross members 42 include a substantial circumferential hook 44 at one end and a semi-circumferential hook 45 at the other end.
End or cross members 42 are made of steel or copper metal and the end hooks 44, 45 have an inside diameter slightly larger than the outside diameter of legs 32 of base portions 31. End or cross members 42 are about 22 to 25 centimeters in length and longitudinal handle member 43 is about 60 centimeters long. The substantially circumferential hooks 44 are attached to one of the legs 32 as shown in FIGS. 28 and 29. Then, for complete assembly, the rectilinear member 41 is rotated about leg 32 to which hook members 44 are attached, engaging hooks 45 on the outer surface of the other leg member 32 completing assembly of the structure as shown, for example, in FIG. 30 and FIG. 33. FIGS. 31, 32 and 33 provide additional views of the fully assembled board and support/base structure of FIG. 30, FIGS. 31-33 being views similar to the views illustrated in FIGS. 23-25.
A fifth embodiment of the support/base for an ironing board of the present invention is illustrated in FIGS. 34 and 35. In this embodiment, the U-shaped base portions 31 are similar to those shown and described in the embodiment of FIGS. 10-12, except that in addition to annular grooves or recesses 38 in the legs 32 to be attached to the bottom surface of the board, the opposite leg 32 also includes a longer circumferential groove or recess 46 which serves as a connecting location for detachable cross brace 47. As further shown in FIG. 34, edge views of cross brace 47 are shown at 47' showing the cross brace in its dis-assembled state as at 47, and further in its assembled state as shown at 47". Each end of cross brace 47 includes a substantially circumferential hook open at the ends of the longitudinal axis of cross brace 47 for grasping leg 32 at circumferential recess 46, as shown in FIG. 35.
This embodiment further comprises a shorter U-shaped element 48 having smaller diameter extensions which fit inside the free ends of tubular legs 32 as shown in FIGS. 34 and 35. As shown in FIG. 34, one of the extended ends of shorter U-shaped element 48 is a longer, lesser diameter portion 49, while the other extension is a shorter lesser diameter portion 50 which, like the corresponding end of tubular leg 32 includes a diametrically bored hole through which a fastener can be affixed for retaining element 48 in the ends of legs 32. The fastener in the hole in the end of extension 50 may constitute a spring-loaded "pip" which can be depressed when inserting extension 50 into the end of tubular leg 32 and the exterior locking portion of the spring-loaded "pip" will then engage in the corresponding hole near the end of tubular legs 32 thus locking short horseshoe 48 in the ends of leg 32. Short horseshoe element 48 has a length of about 20 to 25 centimeters plus the extension fittings. The dimensions of the other elements of this embodiment are similar to the dimensions of the previously described embodiments.
A sixth embodiment of the support/base structure for an ironing board of the present invention is illustrated in FIGS. 36 and 37 which are views similar to those presented for the embodiment shown in FIGS. 34 and 35, particularly the upper base member 31 as illustrated in FIG. 34. The embodiment of FIGS. 36 and 37 also includes a cross bar or member 51, an edge view of which is shown at 51'. One end of end cross bar 51 has a virtually circumferential hook with an opening at the outer periphery, the other end cross bar 51 has a greater than semi-circumferential hook 53, the inner diameter of hooks 52 and 53 being just greater than the outer diameter of the recessed portions 46 of legs 32 of base members 31.
This embodiment also includes a third, smaller horseshoe or U-shaped member 54. The ends of each of the legs of U-shaped member 54 include extensions 50 which include through holes having axes generally parallel to the plane of the U-shaped member. Similarly oriented holes also appear in the exterior surface of leg 32 of each base member 31 into which extensions 50 of horseshoe 54 extend during assembly. Also attached to the interior of the base of the U-shaped member 54 is a generally V-shaped spring-like device lying generally in the plane of U-shaped member 54, and having distal ends of its legs extending generally perpendicular to extensions 50 and located substantially coaxially with the holes in extensions 50. When the horseshoe-shaped member 54 is assembled with base members 31 by inserting extensions 50 into the respective ends of legs 32 of each of the base members 31, horseshoe member 54 is finally locked in engagement with the base members 31 by insertion of the distal ends of spring-like member 55 through the holes near the ends of legs 32 and into the coaxial holes in extensions 50, as shown in FIG. 37.
In FIG. 37 cross bar 51 is also shown with its hooks 52, 53 engaged over recessed portions 46 of legs 32 of base members 31. Horseshoe or U-shaped member 54 is similar in size to corresponding member 34 illustrated in FIG. 3. However, the extensions 50 as illustrated in FIG. 36 extend about 5 centimeters in length and are of reduced diameter sufficient to fit within the interior diameter of legs 32. The spring-like double hook member 55 may be welded to U-shaped member 54 where the base of V-shaped member 55 contacts the interior of the U surface of U-shaped member 54.
A seventh embodiment of the support/base structure for an ironing board of the present invention is illustrated in FIGS. 38 and 39. In this embodiment, the base portions 31 are substantially identical to the lower base member 31 illustrated in FIG. 36, with the exception that there is no hole in the exterior surface near the free end of interior leg 32. This embodiment also includes a third U-shaped member 56 which is similar to size and shape to element 48 illustrated and described in conjunction with FIG. 34, except that this horseshoe 56 includes two lesser diameter extensions 49 each having a length of approximately 10 centimeters and diameter just less than the inside diameter of legs 32 of base members 31. U-shaped member 56 also includes an annular groove or recess 57 in the central base portion of the U portion thereof.
When this embodiment of the support/base structure is assembled as shown in FIG. 39, extensions 49 of the horseshoe 56 are slipped into the open ends of legs 32. The three U-shaped members 31, 31 and 56 are then held together by a T-shaped brace structure comprising a cross bar portion 58 and a longitudinally extending portion 59. An edge view of cross bar 58 is shown at 58' illustrating partially circumferential hook portions 52 and 53 quite similar to the corresponding elements of the embodiment illustrated in FIG. 36. An edge view at 59' of the end of longitudinal bar 59 illustrates hook portion 60. When assembly is completed as shown in FIG. 39, hooks 52 and 53 are engaged over recessed portions 46 of legs 32, and hook 60 is engaged over recessed portion 57 of horseshoe 56. In this way, the T-shaped structure 58, 59 holds the three U-shaped members 31, 31 and 56 together in a stable support/base structure. Cross bar 58 has a length of about 20 centimeters, and longitudinal bar 59 has a length of about 90 centimeters.
An eighth embodiment of the support/base structure for an ironing board of the present invention is illustrated in FIGS. 40, 40A, 40B and 41. In this embodiment, base members 31 correspond in shape and size to those illustrated and described in conjunction with FIG. 19. Base members 31 are connected by a rectilinear structure 60 somewhat similar to structure 40 in FIG. 19, but capable of being disassembled into two distinct portions.
Rectilinear structure 60 comprises tubular rails 39 whose inside diameter is just larger than the outside diameter of leg 32 of base members 31 so that hollow rails 39 can slip fit over legs 32 as shown in FIG. 41. The assembly feature of structure 60 is illustrated in FIG. 40 wherein portions 61 and 62 are shown in partially-exploded schematic relationship. An end view of these elements is shown with portions 61' and 62' being in a partially-exploded relationship between tubular rails 39. The inter-fitting relationship of the three illustrated cross bar portions 63 is illustrated by FIGS. 40A and 40B, respectively, which correspond to views from line XLA in the central portion of FIG. 40. The ends of upper cross bars 63 as shown in FIG. 40 slip into the mating ends shown in the lower portion of structure 60 in FIG. 40, and a pin and hole arrangement in central cross bar 63 provide locking engagement for maintaining the structure 60 in assembled condition as shown in FIG. 41.
A further embodiment of the ironing board of the present invention is illustrated in FIGS. 42-44. FIG. 42 shows an edge view, and FIG. 43 shows a top view of an inventive ironing board which may be dis-assembled into two pieces 64, 65. The mating ends of pieces 64, 65 are illustrated in FIGS. 43A and 43B, respectively, which are views from line XLIII in FIG. 43. The assembled structure, including a support/base structure which likewise may be dis-assembled into shorter lengths, is illustrated in FIG. 44.
FIGS. 45-47 illustrate a further embodiment similar to that illustrated in FIGS. 42-44, but wherein the board portion of the device is a mesh board suitable for use with steam irons. The views of FIGS. 45, 46, 46A, 46B and 47 otherwise correspond to the views of FIGS. 42-44.
FIGS. 48-51 show four embodiments of support/base structures suitable for use with the board embodiments of FIGS. 42-44 and 45-47, respectively. The embodiment illustrated in FIG. 48 may be considered similar to the embodiment first presented in FIG. 3, except that the U-shaped base portions 31 are shorter than the corresponding portions in the embodiment of FIG. 3. Indeed, even the longest legs 32 of the embodiment of FIG. 48 are sufficiently short that the length of the support/base structure as assembled can be reduced almost by half by dis-assembling the structure illustrated in FIG. 48. This is accomplished by making the length of the outer legs 32 dis-assemblable into portions 32A and 32B, respectively, and lengthening the legs of the third U-shaped member 66 as shown in FIG. 48. Thus reduced diameter extensions of the legs of U-shaped member 66 and outer ends of legs 32B are assembled by insertion into the open ends of tubular legs 32 and 32A of tubular base members 31, as described previously herein.
The embodiment of FIG. 49 is quite similar to the embodiment of FIG. 48 except that the embodiment of FIG. 49 includes a plurality of circumferential grooves or recesses 38 on each of the outer legs 32 whereas there is only a single recess 38 on each of the outer legs in the embodiment of FIG. 48.
The further embodiment of FIG. 50 is very similar to the embodiment of FIG. 48 except that leg extension portions 67 are straight, rather than being connected by a U-shaped bend as in element 66 in the embodiment of FIG. 48. The further embodiment of FIG. 51 relates to the embodiment of FIG. 49 in the same way that the embodiment of FIG. 50 relates to the embodiment of FIG. 48. In any of the embodiments of FIGS. 48-51, the extensions which fit inside the tubular leg portions may simply push or slide directly in, or may be fitted with threads to screw into engagement with each other. The embodiments of FIGS. 50 and 51, when assembled, look similar to those illustrated in FIGS. 18 and 19.
Further features of the ironing board of the present invention are illustrated in the embodiment shown in FIGS. 52-56. In FIG. 52, the bottom surface of an ironing board is shown with cover-retaining pins or hooks 68 shown at locations spaced around the periphery of the bottom of the board. FIGS. 53 and 54 are end views of a board like that illustrated in FIG. 52 showing only the location of fastening means for retaining legs 32 of base members of support/base structures assembled in conjunction with such a board. FIG. 55 shows a board like that illustrated in FIG. 52 lying bottom side up on a flexible ironing board cover. Again, pins or hooks 68 are shown around the periphery of the board, and corresponding loops 69 are shown around the periphery of the cover. FIG. 56 shows the cover having been installed on the board by looping loops 69 over pins or hooks 68 thereby securing the cover on the ironing board.
A further embodiment of the ironing board of the present invention is illustrated in FIGS. 57-61, which generally correspond to the views of the embodiment illustrated in FIGS. 52-56, respectively. However, the board illustrated in FIG. 57 has a mesh surface as mentioned previously in conjunction with embodiment of FIGS. 45 and 46. The surface of the board itself is cut from metallic mesh and is about 120 centimeters long, tapering from a width of about 22 centimeters near the left end to a width of about 9 centimeters near the right end. A metal strip about 2.5 centimeters tall is attached, for example, by welding, around the edge of the metal mesh surface. Two reinforcing bars of angle iron, as shown in FIGS. 58 and 59, are attached, by welding, to the underside of the mesh to reinforce it throughout its length. Rings or saddle clips are attached to the reinforcing bar, for example by welding, to attach the mesh board to a suitable support/base structure as described herein. FIG. 60 illustrates a board such as that shown in FIG. 57 lying bottom side up on a flexible ironing board cover, which cover includes ties 70 extending from locations spaced around the periphery of the flexible cover. FIG. 61 shows pairs of ties tied together across the bottom side of the board thus securing the cover onto the board.
Further embodiments of board shapes and attached covers are shown in FIGS. 62-66, 72-76 and 82-86 which correspond, respectively, to the views illustrated in FIGS. 52-56. And, further embodiments of the shapes of mesh boards of the present invention, with covers, are illustrated in FIGS. 67-71, 77-81, and 87-91, respectively, which views correspond to the views illustrative of the embodiments shown in FIGS. 57-61.
Still further features of the ironing boards of the present invention are illustrated in FIGS. 92-97 and 98-105, respectively. FIGS. 92, 94, 95 and 96 illustrate a smaller ironing board of the present invention having a pivot fixture whereby the board may swing in a plane generally corresponding to the plane of the board itself about an axis perpendicular to that plane and located near the wider end of the smaller board. This pivot fixture 80 is shown as concentric circles in FIG. 92 and as a single circle in FIGS. 94 and 94A.
A base portion 81 shown in FIGS. 94A and 97A has a rectangular base upon which a lower portion of the circular pivot device is mounted. The rectangular base is attached to the bottom surface of the smaller ironing board with the circular portion extending upwardly through a circular hole in the smaller board. Once the lower portion 81 is secured to the bottom of the board, upper portion 82 illustrated in FIG. 97B can be installed from the top of the board and connected, for example, by screw threading with lower portion 81, thus holding the board yet permitting the board to pivot about an axis perpendicular to the board at about the center of circles 80.
The connected upper and lower portions 82, 81 of the pivot device are shown in broken lines in the side and end views of FIGS. 95 and 96, respectively.
Lower portion 81 also has fasteners 83 thereon, such as saddle fasteners or the like, for securing legs 84 of U-shaped support members 85 to the bottom of the small board, as illustrated in FIGS. 94 and 95. The support system also comprises straight tubular member 86 which may be secured to the lower surface of a larger ironing board or ironing table 87 as illustrated in FIG. 95, so that arms 84' of support members 85, as shown in FIG. 94, can be inserted within tubular members 86 as shown in FIGS. 95 and 96 thus supported the smaller board of the present invention over larger ironing table or board 87. This arrangement permits use of the smaller board of the present invention directly over a larger ironing board or table 87 whenever desired, yet the larger surface of board or table 87 may be used without interference by the smaller board by simply rotating the smaller board about the axis of the pivot device 80 thereby moving the smaller board away from the top surface of larger board or table 87.
Still a further embodiment of the ironing board structure of the present invention is illustrated in FIGS. 98-105, respectively. The small board with pivoting device as illustrated in FIGS. 98-102 is similar in detail to the embodiment illustrated in FIGS. 92-97B except that the embodiment of FIGS. 98-102 may be dis-assembled like the board embodiment illustrated in FIGS. 42-43B, supra. Additionally, the supporting members 95 each have legs 84 which are quite similar to legs 84 in the embodiment of FIGS. 92-94, however, the opposite legs 96 terminate in circumferential sleeves 97 which are fixed on a rod 98 connected to the lower surface of larger ironing board or table 87 as shown in FIGS. 103-105. This structure is complemented by bar 99 which is pivotally secured at one end to the underside of larger ironing board or table 87 and releasably secured at its other end by a tightening knob or the like for locking support members 95 in relationship to the bottom surface of larger board or table 87, as shown in FIGS. 103, 104 and 105.
The embodiment of FIGS. 98-105 provides additional flexibility in that not only can it be dis-assembled and stored in a smaller space, but the detachable right-hand portion of the smaller board can be extended, at least somewhat, during use, for example when ironing on entire sleeve or children's trousers or the like. To facilitate such use, any cover placed on the two-piece, extendable ironing board, likewise needs to be in corresponding separate pieces. FIGS. 95 and 103 also illustrate that larger ironing board or table 87 may include an iron rest 87' on which an iron being used may be placed while the smaller board of the present invention may be swiveled into and out of position for use over the upper surface of the larger ironing board or table 87. And, this adjustment of the smaller board into and out of useful position over the upper surface of larger board 87 can be accomplished without interfering with a hot iron located in iron rest 87'. Similarly, the iron may be placed and removed from iron rest 87' without collision with the smaller board of the present invention.
Other advantages and obvious variants of the advantageous ironing board structure of the present invention may occur to those conversant with this art and are intended to be included within the scope and spirit of the invention as claimed in the following claims. | An ironing board for thoroughly ironing all parts of trousers, skirts and two-legged garments whether plain or pleated at the waist and having pockets, as well as blouses, dresses and jackets, including the whole of each sleeve. The ironing board is a long, thin board onto which the garment is passed and below which are two U-shaped supporting legs hingedly interconnected by their upper horizontal arms so that they can be folded out flat on either side of the board, and also can connect the lower horizontal arms of the two legs together so that they are further apart than the spacing between the two upper arms to ensure that the two legs remain stable in the erected position. The ironing board can be placed on an ordinary table or on a standard ironing board. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. provisional patent application Ser. No. 61/286,338, filed Dec. 14, 2009, entitled “METHOD AND APPARATUS FOR CHARGE LEAKAGE COMPENSATION FOR CHARGE PUMP WITH LEAKY CAPACITIVE LOAD.”
FIELD OF TECHNOLOGY
[0002] The present application generally relates to charge pumps and more particularly relates to compensation of charge leakage in charge pump circuitry for charge pumps having a leaky capacitive load.
BACKGROUND
[0003] A phase lock loop (PLL) is an important apparatus that is used in numerous applications. A PLL receives a reference clock and generates accordingly an output clock that is phase locked with the reference clock. A phase lock loop typically comprises a controller and a controlled oscillator. The controlled oscillator outputs an output clock with a frequency controlled by a control signal generated by the controller. The output clock is usually divided down by a factor of N, where N is an integer, resulting in a divided-down clock. The controller issues the control signal based on detecting a phase difference between a reference clock and the divided-down clock. The frequency of the output clock is thus controlled in a closed-loop manner so as to minimize a phase difference between the reference clock and the divided-down clock. In a steady state, the output clock is thus phase locked with the reference clock.
[0004] In a typical PLL, the controller comprises a phase detector and a filter. The phase detector receives the reference clock and the divided-down clock and outputs a detector output signal representing a phase difference between the reference clock and the divided-down clock. The filter receives and converts the detector output signal into the control signal to control the controlled oscillator. In a typical PLL, the phase detector comprises a PFD (phase/frequency detector) and a charge pump circuit, and the resultant detector output signal is a current-mode signal. The filter serves as a capacitive load for the charge pump circuit, and effectively filters and converts the current-mode detector output signal into a voltage-mode control signal to control the oscillator, which is a voltage-controlled oscillator (VCO). Modern phase lock loops are usually implemented in a CMOS (complementary metal-oxide semiconductor) integrated circuit. In a deep submicron CMOS integrated circuit, high-speed devices of short channel lengths are prone to charge leakage. In particular, the capacitive load is prone to charge leakage due to either using a leaky MOS transistor as capacitor or interfacing with leaky MOS transistors. The charge leakage at the capacitive load effectively introduces an error in the phase detection, which results in an error in the voltage-mode control signal and thus an error in the phase/frequency of the output clock. The error in the phase/frequency of the output clock is generally referred to as clock jitter.
[0005] Accordingly, what is desired is a method to reduce the clock jitter due to charge leakage of the capacitive load of the charge pump.
SUMMARY OF THIS INVENTION
[0006] An embodiment of the present invention is directed to an apparatus comprising: a charge pump to receive a phase signal representing a result of a phase detection and to output a current flowing between an internal node of the charge pump and an output node of the charge pump; a capacitive load coupled to the output node; a current source controlled by a bias voltage to output a compensation current to the output node; a current sensor coupled between the internal node and the output node to sense the current; and a feedback network to generate the bias voltage in accordance with an output of the current sensor.
[0007] Another embodiment of the invention is directed to a method for compensating charge leakage of a charge pump, the method comprising: receiving a phase signal representing a result of a phase detection; converting the phase signal into a current signal using the charge pump; transmitting the current signal into a capacitive load; detecting the current signal using a current sensor; injecting a compensation current into the capacitive load in accordance with a control voltage; and adapting the control voltage using a feedback network in accordance with an output of the current sensor.
DETAILED DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows a schematic diagram of a circuit in accordance with the present invention.
DETAILED DESCRIPTION
[0009] The following detailed description refers to the accompanying drawings which show, by way of illustration, various embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice these and other embodiments. The various embodiments are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The following detailed description is, therefore, not to be taken in a limiting sense.
[0010] FIG. 1 shows a schematic diagram of a circuit 100 in accordance with an embodiment of the invention. Circuit 100 comprises: a charge pump 110 for receiving a phase signal (comprising a first logical signal UP and a second logical signal DN) and outputting a current signal I OUT at an internal node 105 ; a capacitive load 120 comprising a capacitor CL for receiving the current signal I OUT and converting the current signal I OUT into an output voltage VOUT at an output node 107 ; a current sensor 140 embodied by a resistor RS inserted between the internal node 105 and the output node 107 for sensing the current signal I OUT ; a compensation network 160 embodied by a PMOS transistor M 1 biased by a bias voltage VBP for injecting a compensation current I C into the output node 107 ; and a feedback network 150 embodied by an operational amplifier 152 loaded with an integrating capacitor CI for generating the bias voltage VBP. Here, VDD denotes a first substantially fixed-potential node (usually at an output of a power supply), and VSS denotes a second substantially fixed-potential node (usually referred to as “ground”).
[0011] For illustration purpose, FIG. 1 further includes an equivalent circuit 130 (e.g., a fictitious shunt) comprising a load resistor RL at the output node 107 serving as an illustrative equivalent circuit to model the phenomenon of the charge leakage of the capacitive load 120 . Note that in a real circuit embodiment, it is futile (and even detrimental) to purposely insert a real shunt circuit like equivalent circuit 130 at the output node 107 . Certain principles of this invention are explained below.
[0012] In a typical application to a phase lock loop, circuit 100 receives the phase signal (comprising the two logical signals UP and DN) as a timing detection result from a preceding phase detector (not shown in the FIGURE), and outputs the output voltage VOUT for controlling a succeeding voltage controlled oscillator (not shown in the FIGURE). A timing of an output clock of the voltage controlled oscillator is detected by comparing it with a reference timing (usually provided by a crystal oscillator) by the preceding phase detector. When a frequency of an output clock of the voltage controlled oscillator is too high, a timing of the output clock is often too early; this causes the second logical signal DN to be asserted more frequently, resulting in a decrease in the output voltage VOUT to decrease the frequency of the output clock. When the frequency of the output clock of the voltage controlled oscillator is too low, the timing of the output clock is often too late; this causes the first logical signal UP to be asserted more frequently, resulting in an increase in the output voltage VOUT to increase the frequency of the output clock. In this closed-loop manner, the output voltage VOUT is adjusted and settled into a value such that the frequency of the output clock is neither too high nor too low but just right. In the steady state, the output voltage VOUT must be settled, and therefore the following condition must be met:
[0000] I OUT +I C −I L =0 (1)
[0013] Here, denotes a statistical mean. Equation (1) provides that the mean net current following into the output node 107 must be zero, otherwise the output voltage VOUT cannot be settled. If the mean value of I OUT is positive, the current sensor 140 senses a positive current more frequently, causing the feedback network 150 to gradually lower the bias voltage VBP, leading to an increase to the compensation current I C and accordingly the output voltage VOUT; this leads to an increase to the frequency of the output clock and accordingly an earlier timing that results in the second logical signal DN being asserted more frequently and thus a reduction of the mean value of I OUT . If the mean value of I OUT is negative, the current sensor 140 senses a negative current more frequently, causing the feedback network 150 to gradually elevate the bias voltage VBP, leading to a gradual decrease to the compensation current I C and accordingly the output voltage VOUT; this leads to a decrease to the frequency of the output clock and accordingly a later timing that results in the first logical signal UP being asserted more frequently and thus an increase of the mean value of I OUT (but a decrease in an absolute value of the mean value of I OUT since it is negative). In either case, the phase lock loop reacts so as to reduce the absolute value of the mean value of I OUT . In the steady state, the mean value of I OUT must be zero, otherwise the bias voltage VBP will either keep increasing or keep decreasing. By applying I OUT =0 to equation (1), one has
[0000] I C −I L =0 (2)
[0014] That is, the leakage current I L is exactly compensated by the compensation current l C . In this manner, the detrimental effect of the leakage current is effectively alleviated.
[0015] However, in practical design one must choose a sufficiently large capacitance value for the integrating capacitor CI, so that the bias voltage VBP is adjusted much slower than the phase lock loop adjusts the output voltage VOUT (otherwise the phase lock loop may encounter instability).
[0016] Charge pump 110 comprises a current source I 1 , a current sink 12 , a first switch S 1 , and a second switch S 2 . When the first logical signal UP is asserted, the current source 11 injects current into the internal node 105 . When the second logical signal DN is asserted, the current sink 12 drains current from the internal node 105 .
[0017] In an alternative embodiment (not shown in FIG. 1 ), the capacitive load 120 comprises a serial connection of a resistor and a capacitor.
[0018] In embodiment 100 , it is assumed that the capacitive load 120 , as a stand-alone circuit, is leaking toward VSS, and therefore the equivalent circuit 130 comprises a resistor shunt between the output of the capacitive load and VSS and consequently the compensation network 160 must inject current into the output of the capacitive load to compensate for the charge leakage. Depending on the actual embodiment of the capacitive load 120 , however, it is possible that the capacitive load 120 , as a stand-alone circuit, is leaking toward VDD. In this case, the equivalent circuit 130 must be a resistor shunt between the output of the capacitive load 120 and VDD and consequently the compensation network 160 must drain current from the output of the capacitive load 120 ; this can be fulfilled by changing the PMOS transistor M 1 into a NMOS transistor. Those of ordinary skills in the art would appreciate other implementation details not particularly described herein.
[0019] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover adaptations and variations of the embodiments discussed herein. Various embodiments use permutations and/or combinations of embodiments described herein. It is to be understood that the above description is intended to be illustrative, and not restrictive, and that the phraseology or terminology employed herein is for the purpose of description. | An apparatus comprises a charge pump to receive a phase signal representing a result of a phase detection and to output a current flowing between an internal node of the charge pump and an output node of the charge pump; a capacitive load coupled to the output node; a current source controlled by a bias voltage to output a compensation current to the output node; a current sensor coupled between the internal node and the output node to sense the current; and a feedback network to generate the bias voltage in accordance with an output of the current sensor. A comparable method is also disclosed. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] Aspects of the present invention relate to a reclaimer machine for reclaiming and homogenizing materials such as ore, coal and others, either stocked or accumulated in yards.
[0003] 2. Description of Related Art
[0004] The machines currently available for reclaiming and homogenizing materials from stacks in storage yards are generally divided into two models: bridge reclaimer with bucket wheels, and drum reclaimer.
[0005] The bridge reclaimer with wheels and bucket is generally divided into three sets: (a) feed system on the stack, (b) system of lateral movement of the bucket wheels and rake and (c) turning system for digging and recovery of stack material. The dynamics of the operation is due by the synchronization of the feed, lateral and turning movement of these sets. As a result of the synchronized movements of these sets, the digging and recovery material from the stack is discharged in the center of the wheel, where there is a conveyor belt internal to the wheel and perpendicular to the stack receiving all the material which in turn gives sequence to the recovered material flow.
[0006] A similar setup exists in the case of a drum reclaimer, except that there is no lateral movement because the digging and recovery of the material against the stack occurs through the use of a drum designed with buckets that comprise the entire length of the storage yard, requiring, therefore, two basic movements from the machine, a forward movement towards the stack, and the rotation of the drum that discharges the material into the drum, similarly to the bridge reclaimer with wheels and bucket. There may be a conveyor belt internal to the wheel and perpendicular to the stack that receives the material and gives a sequence to the recovered material flow.
[0007] For the reclaimer machines currently available, supporting structures directly linked and supportive of the digging and recovery systems are necessary. They are positioned in locations above, or perpendicularly internal to, these systems. Further, such a configuration uses conveyor belts internal and central to these systems that are perpendicular to the stack. This configuration has the disadvantage of preventing direct access, e.g., for disassembly and assembly of the systems.
SUMMARY OF THE INVENTION
[0008] Various aspects of the present invention include a reclaimer machine that is cost-effective in construction and manufacture, as well as providing advantages with respect to maintenance and repair throughout its life cycle, which significantly reduces operational downtime.
[0009] Aspects of this invention also provide a structurally simple reclaimer machine, capable of maintaining the required sturdiness to perform the tasks to which the reclaimer applies.
[0010] Aspects of the present invention change and simplify the conventional configurations. The construction and position of the digging and recovery systems in the machine according to aspects of the present invention allow for the free access to the digging and recovery systems because no supporting structures are needed, thus avoiding structures disposed above and/or perpendicularly inside these systems. Furthermore, the conveyor belt (that receives the recovery material from the stack) is not positioned inside and centrally to the digging and recovery systems.
[0011] In order to enable these changes, aspects of the reclaimer machine according to the present invention use a counterweight in one end, allowing the use of the support structure (bridge) only in the central part of the machine and thus eliminating the need for using the support structure to support the rotation and lateral movement of the digging and recovery sets required by the current machines. This possibility is due to the fact that in aspects of the present invention, all the support of the front part of the machine—a set of rotation, digging and recovery of material—is sustained in a balance configuration from a central axis. Therefore, such a structure also enables the use of a conveyor belt external to the set of rotation, which is longitudinal to the pile.
[0012] According to aspects of the current invention, a reclaimer machine may include a bucket wheel that includes a series of buckets rotating around a shaft, a conveyor belt connected to the bucket wheel and to a transfer chute, the conveyor belt being supported by a mobile upper platform that moves laterally towards a pile of material to be transported on tracks attached to a mobile lower platform, wherein a first end of the conveyor belt structure may be connected to the bucket wheel, and another end of the conveyor belt structure may be connected to a first counterweight that maintains the balance of the reclaimer machine and supports the bucket wheel and upper platform movements.
[0013] According to aspects of the current invention, a principle of the machine, which reclaims piles of material and homogenizes the material, is that the machine works by means of forward movements and lateral translation of one or more bucket wheels placed on a horizontal base structure.
[0014] Additional advantages and novel features of these aspects of the invention will be set forth in part in the description that follows, and in part will become more apparent to those skilled in the art upon examination of the following or upon learning by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Various exemplary aspects of the systems and methods will be described in detail, with reference to the following figures, wherein:
[0016] FIG. 1 is a schematic view of a reclaimer machine according to various aspects of the current invention;
[0017] FIG. 2 is a side view of an aspect of a reclaimer machine according to various aspects of the current invention; and
[0018] FIG. 3 is a side view of an aspect of a reclaimer machine according to various aspects of the current invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary aspects.
[0020] Based on the various aspects of the current invention illustrated on FIGS. 1 to 3 , the reclaimer machine 100 may include a bucket wheel 1 having a series of buckets 8 rotating around a shaft 2 , driven by an engine and reducer (not illustrated), or by driving force (torque), for example, from a hydraulic engine. The bucket wheel 1 may be connected to a conveyor belt structure 3 , which holds the bucket wheel 1 and may also be connected to a transfer chute 5 .
[0021] FIG. 1 is a schematic view of a reclaimer machine according to various aspects of the current invention, and FIG. 2 is a side view of an aspect of a reclaimer machine according to various aspects of the current invention. A rake-type supporting structure 30 may be connected to the conveyor belt structure 3 which holds a counterweight 6 . This structure 30 may comprise a rake 31 with scarificators pointed towards the pile 20 or stack, aimed at dismantling the pile 20 . All of these structural connections may vary according to specific parameters of development of a particular project.
[0022] The conveyor belt structure 3 may be supported by an upper platform 4 . This upper platform may be placed over at least a pair and preferably two pairs of wheel sets 10 , which may move laterally to the pile 20 , on tracks 11 attached to a lower platform 7 . The lateral movement with regard to the pile of platform 4 may be driven by, but not limited to, motor bogies, chain and pinion or hydraulic or pneumatic systems. The lower platform 7 may be driven by motor bogies 14 in order to support the upper platform 4 and all of the machine's upper portion. Depending on the capacity and on the requirements, both upper 4 and lower 7 platforms can be structured with box girders or lattice bridge, designed to decrease the weight of the whole structure.
[0023] The first end 21 of the conveyor belt structure 3 may be connected to the bucket wheel 1 . The other end 22 of the conveyor belt structure 3 may be connected to a counterweight 6 , which helps balance the machine 100 against its own weight and also additional weight when the buckets 8 are loaded with material from the pile 20 .
[0024] A second counterweight 6 ′ may be placed in the lower platform 7 , at the opposite end of the bucket wheel 1 , in order to balance the lower platform 7 when the buckets 8 are loaded.
[0025] According to various aspects, the counterweights may allow the use of the support structure (bridge) only in the central part of the reclaimer machine 100 , thus eliminating the need for use a support structure to support the rotation of bucket wheel 1 and lateral movement of the upper 4 and lower 7 platforms. In this case, all the support of the front part of the reclaimer machine 100 —the bucket wheel 1 and buckets 8 —is sustained in the balance configuration from a central axis. Therefore, this configuration also enables the use of a conveyor belt structure 3 that is external to the bucket wheel 1 .
[0026] According to various aspects, the bucket wheel 1 may be driven by a driving force (torque) that may be provided by an engine, with or without a frequency inverter for speed variation, as well as a speed reducer and/or any other device, such as a hydraulic motor, connected to a shaft 2 in order to drive the wheel 1 . The material from the pile 20 is reclaimed/loaded by the buckets 8 through the rotation of the wheel 1 , and then dumped in the conveyor belt placed in the conveyor belt structure 3 that is external to the bucket wheel 1 . The lateral movement/translation of the upper platform 4 in relation to the pile 20 of material to be loaded allows for an effective and homogenous handling of the pile 20 .
[0027] According to various aspects, the conveyor belt structure 3 conveys the loaded material up to the transfer chute 5 , which transfers or unloads it onto the reversible conveyor 9 attached to the lower platform 7 . Aimed at flow sequence and transportation of the material in the yard conveyor 17 , the reversible conveyor 9 unloads the material into other chutes, namely 16 A and 16 B, depending on the direction of the machine flow.
[0028] According to various aspects, the lateral movement/translation of the upper platform 4 in relation to the pile 20 may be driven in different ways, for example using motor-driven wheel sets 10 , chain or hydraulic cylinders.
[0029] In addition to the bucket wheel 1 spin movement and the lateral translation/movement of the upper platform 4 , the lower platform 7 moves in a longitudinal way towards the yard (straightforward in relation to the pile) by means of motor bogies 14 .
[0030] All of the reclaimer machine 100 components and structures, as well as their respective composing items, may move in line with the lower platform 7 and the motor bogies 14 .
[0031] The bucket wheel 1 , the conveyor belt structure 3 , the transfer chute 5 and the counterweight 6 make up a structural set which moves while connected to the upper platform 4 . The structural set can be arranged according to several configurations, with different components and quantities depending on how the reclaimer machine 100 is to be used.
[0032] According to the needs and interests of the project, any dynamic part of the machine can have variable speed. In addition, in order to reverse the reclaimer's direction, the machine may include the installation of a system at the ends of the yard so as to allow for the machine to rotate 180° using a specific car/platform.
[0033] FIG. 3 is a side view of an aspect of a reclaimer machine according to various aspects of the current invention. Based on this aspect, the reclaimer machine 100 may include the same components and functions described in the previous configuration. However, the first conveyor belt 3 may be inclined at an angle, and both the transfer chute 5 and the counterweight 6 are bigger and more suitable to fit the belt's incline. The other described functions may remain the same as with respect to FIGS. 1 and 2 described above.
[0034] Some of the advantages of the reclaimer machine 100 , as compared against similar known machines, may include one or more of the following:
General Advantages
[0035] The described aspects may provide one or more of the following:
[0036] Considerably simplified general maintenance and higher life cycle components and subsets when compared with those used in machines for the same purpose although with a different design;
[0037] Simplicity regarding mechanical, structural and electric/electronic components;
[0038] Possibility of standardizing the components of, but not limited to, the bucket wheel and its driving system, according to other likewise uniquely-designed machines such as the Bucket Wheel Reclaimer;
[0039] Reduced risks of personal accidents due to simplified maintenance;
[0040] Reduced costs with general components and spare parts;
[0041] Use of bridge, robust box girders, structural arch for supporting the bucket wheels or drums, which hold a history of high incidence of cracks as well as structural collapse risks during life cycle, becomes unnecessary;
[0042] Compared with conventional reclaiming devices, misalignments due to forward movement from one end to the other are decreased due to the platform-type horizontal structure, which provides higher horizontal stability for the machine's structure;
[0043] The access for handling and lifting cargo is improved, specially from the bucket wheel, since there is no structure on top of the bucket wheel, in opposition to currently available machines, in which there is a bridge (box girder) over the bucket wheel or drum; and
[0044] The use of docks for maintenance is facilitated since aspects of the reclaimer machine of the current invention are not as tall as the conventional reclaimer machines.
Advantages With Respect To Conventional Bridge-Type Bucket Reclaimers
[0045] The described aspects may provide one or more of the following:
[0046] Use of spin, guiding rolls and/or supporting rolls bearing becomes unnecessary (a component that in addition to being special and of great diameter is also expensive in terms of acquisition and replacement);
[0047] Ease of maintenance (bucket wheels can be removed without interfering with components, such as the conveyor belt, bearings, shaft or drivers as is the case with currently available machines);
[0048] Easier access for inspection and maintenance along the whole conveyor belt used in the machine;
[0049] Easier access for inspection of the bucket wheel's bearing and simplicity regarding removal/disassembly of bucket wheel(s);
[0050] Use of rack and pinion to spin the bucket wheel becomes unnecessary;
[0051] Lateral movement of the mobile upper platform, using chain or even a hydraulic cylinder;
[0052] Reduced overall cost;
[0053] Simplicity of construction and manufacturing; and
[0054] Operational simplicity;
Advantages With Respect To Conventional Drum Reclaimers
[0055] The described aspects may provide one or more of the following:
[0056] Use of a drum (high manufacture, transportation and maintenance costs, expensive life cycle due to higher level of effort as a result of its constructive form) becomes unnecessary;
[0057] Use of bridge, robust box girders or structural arch for supporting the bucket wheels or drums, which hold a history of high incidence of cracks as well as structural collapse risks during life cycle, becomes unnecessary;
[0058] Use of supporting rolls becomes unnecessary;
[0059] Use of spin tracks becomes unnecessary;
[0060] Use of guiding rolls becomes unnecessary;
[0061] Use of rack and pinion to spin the bucket wheel becomes unnecessary;
[0062] Use of the drum's spin drivers, which require synchronism and have a high maintenance rate and a number of components, becomes unnecessary;
[0063] Elimination of risks and occurrences of clogging on the drum's internal conveyor, since in the design according to aspects of the current invention, the conveyor used may be placed externally to the buckets, and is thus not being affected by pile discharge and providing ease of access for inspections;
[0064] Decreased general maintenance due to reduced number of components and the use of higher life cycle components if compared with current designs;
[0065] Use of components and systems intended for moving the rakes, which increase maintenance and manufacture costs, becomes unnecessary;
[0066] Elimination of risks related to cracks and structural collapses in the drum, which is subject to great effort due to bending and twisting moments;
[0067] The machine can alternatively operate without one of the wheels (in the case of maintenance or any other problem); and
[0068] The axial movement is shorter when, for example, operating with three bucket wheels on the platform reclaimer, thus allowing for the wheels to work less time on axial load.
[0069] While this invention has been described in conjunction with the exemplary aspects of a reclaimer machine outlined above, various alternatives, modifications, variations, improvements, and/or substantial equivalents, whether known or that are or may be presently unforeseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the exemplary aspects of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention. Therefore, the invention is intended to embrace all known or later-developed alternatives, modifications, variations, improvements, and/or substantial equivalents. | Aspects of this invention include a reclaimer machine for reclaiming and homogenizing materials such as ore, coal and others, stock-piled in yards. The reclaimer machine may include a bucket wheel having a series of buckets rotating around a shaft, a conveyor belt connected to the bucket wheel and to a transfer chute, the conveyor belt being supported by a mobile upper platform that moves laterally to a pile on tracks attached to a mobile lower platform, wherein a first end of the conveyor belt structure may be connected to the bucket wheel and another end of the conveyor belt structure may be connected to a counterweight which maintains the balance of the reclaimer machine and supports the bucket wheel, upper platform and lower platform movements. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a Continuation Application of U.S. application Ser. No. 11/008,113 filed on Dec. 10, 2004, now U.S. Pat. No. 7,077,496 which is a Continuation Application of U.S. application Ser. No. 10/296,526, filed Nov. 23, 2002, now issued U.S. Pat. No. 6,893,109, which is a 371 of PCT/AU00/00596, filed May 24, 2000, all of which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a printhead capping arrangement for a printer.
More particularly, though not exclusively, the invention relates to a printhead capping arrangement for an A4 pagewidth drop on demand printhead capable of printing up to 1600 dpi photographic quality at up to 160 pages per minute.
The overall design of a printer in which the arrangement can be utilized revolves around the use of replaceable printhead modules in an array approximately 8 inches (20 cm) long. An advantage of such a system is the ability to easily remove and replace any defective modules in a printhead array. This would eliminate having to scrap an entire printhead if only one chip is defective.
A printhead module in such a printer can be comprised of a “Memjet” chip, being a chip having mounted thereon a vast number of thermo-actuators in micro-mechanics and micro-electromechanical systems (MEMS). Such actuators might be those as disclosed in U.S. Pat. No. 6,044,646 to the present applicant, however, there might be other MEMS print chips.
The printhead, being the environment within which the printhead capping arrangement of the present invention is to be situated, might typically have six ink chambers and be capable of printing four color process (CMYK) as well as infra-red ink and fixative.
Each printhead module receives ink via a distribution molding that transfers the ink. Typically, ten modules butt together to form a complete eight inch printhead assembly suitable for printing A4 paper without the need for scanning movement of the printhead across the paper width.
The printheads themselves are modular, so complete eight inch printhead arrays can be configured to form printheads of arbitrary width.
Additionally, a second printhead assembly can be mounted on the opposite side of a paper feed path to enable double-sided high speed printing.
CO-PENDING APPLICATIONS
Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention simultaneously with the present application:
PCT/AU00/00518, PCT/AU00/00519, PCT/AU00/00520, PCT/AU00/00521, PCT/AU00/00522, PCT/AU00/00523, PCT/AU00/00524, PCT/AU00/00525, PCT/AU00/00526, PCT/AU00/00527, PCT/AU00/00528, PCT/AU00/00529, PCT/AU00/00530, PCT/AU00/00531, PCT/AU00/00532, PCT/AU00/00533, PCT/AU00/00534, PCT/AU00/00535, PCT/AU00/00536, PCT/AU00/00537, PCT/AU00/00538, PCT/AU00/00539, PCT/AU00/00540, PCT/AU00/00541, PCT/AU00/00542, PCT/AU00/00543, PCT/AU00/00544, PCT/AU00/00545, PCT/AU00/00547, PCT/AU00/00546, PCT/AU00/00554, PCT/AU00/00556, PCT/AU00/00557, PCT/AU00/00558, PCT/AU00/00559, PCT/AU00/00560, PCT/AU00/00561, PCT/AU00/00562, PCT/AU00/00563, PCT/AU00/00564, PCT/AU00/00565, PCT/AU00/00566, PCT/AU00/00567, PCT/AU00/00568, PCT/AU00/00569, PCT/AU00/00570, PCT/AU00/00571, PCT/AU00/00572, PCT/AU00/00573, PCT/AU00/00574, PCT/AU00/00575, PCT/AU00/00576, PCT/AU00/00577, PCT/AU00/00578, PCT/AU00/00579, PCT/AU00/00581, PCT/AU00/00580, PCT/AU00/00582, PCT/AU00/00587, PCT/AU00/00588, PCT/AU00/00589, PCT/AU00/00583, PCT/AU00/00593, PCT/AU00/00590, PCT/AU00/00591, PCT/AU00/00592, PCT/AU00/00584, PCT/AU00/00585, PCT/AU00/00586, PCT/AU00/00594, PCT/AU00/00595, PCT/AU00/00596, PCT/AU00/00597, PCT/AU00/00598, PCT/AU00/00516, PCT/AU00/00517, PCT/AU00/00511, PCT/AU00/00501, PCT/AU00/00502, PCT/AU00/00503, PCT/AU00/00504, PCT/AU00/00505, PCT/AU00/00506, PCT/AU00/00507, PCT/AU00/00508, PCT/AU00/00509, PCT/AU00/00510, PCT/AU00/00512, PCT/AU00/00513, PCT/AU00/00514, PCT/AU00/00515
The disclosures of these co-pending applications are incorporated herein by cross-reference. Each application is temporarily identified by its docket number. This will be replaced by the corresponding PCT Application Number when available.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide an arrangement for reducing of print nozzles during non-use of a printer.
It is another object of the present invention to provide an arrangement for reducing nozzle blockage during non-use, suitable for the pagewidth printhead assembly as broadly described herein.
It is another object of the present invention to provide an arrangement for reducing nozzle blockage for a printhead assembly on which there is mounted a plurality of print chips, each comprising a plurality of MEMS printing devices.
SUMMARY OF THE INVENTION
The present invention provides an inkjet printer, including a printhead having a plurality of print nozzles for selectively ejecting drops of ink towards a print medium passing said nozzles, the printhead further having a structure that defines a space adjacent said nozzles, and a capping mechanism; such that,
when the printer is in an operational mode, the structure allows drops of ink ejected from the nozzles to strike the print medium while preventing contact between the nozzles and foreign bodies larger than a threshold size; and,
when the printer is in a non-operational mode, the capping mechanism is engageable with the structure to provide a closed atmosphere in the space.
Preferably, the structure includes a nozzle guard the space being defined between the nozzle guard and the nozzles, the nozzle guard having a plurality of apertures aligned with the nozzles so that ink drops ejected from the nozzles pass through the apertures to be deposited on the paper or other print medium.
Preferably, the nozzles are arranged in an array extending across at least an A4 pagewidth, the nozzles preferably comprising MEMS devices. Preferably, the nozzles are arranged on a plurality of print modules of the printhead each with a respective nozzle guard and space.
Preferably, air valve means shuts off air supply to the spaces when the printer is in a non-printing operational mode.
Preferably, said capping mechanism covers the nozzle guard to seal the nozzle from atmosphere by moving to a capping position when said printer is in said non-printing mode.
Preferably also, the capping member is located on a rotatable platen member of the printer, and includes a seal member contacting said printhead in a locus surrounding said nozzle guard apertures.
As used herein, the term “ink” is intended to mean any fluid which flows through the printhead to be delivered to a sheet. The fluid may be one of many different coloured inks, infra-red ink, a fixative or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein:
FIG. 1 is a front perspective view of a print engine assembly
FIG. 2 is a rear perspective view of the print engine assembly of FIG. 1
FIG. 3 is an exploded perspective view of the print engine assembly of FIG. 1 .
FIG. 4 is a schematic front perspective view of a printhead assembly.
FIG. 5 is a rear schematic perspective view of the printhead assembly of FIG. 4 .
FIG. 6 is an exploded perspective illustration of the printhead assembly.
FIG. 7 is a cross-sectional end elevational view of the printhead assembly of FIGS. 4 to 6 with the section taken through the centre of the printhead.
FIG. 8 is a schematic cross-sectional end elevational view of the printhead assembly of FIGS. 4 to 6 taken near the left end of FIG. 4 .
FIG. 9A is a schematic end elevational view of mounting of the print chip and nozzle guard in the laminated stack structure of the printhead
FIG. 9B is an enlarged end elevational cross section of FIG. 9A
FIG. 10 is an exploded perspective illustration of a printhead cover assembly.
FIG. 11 is a schematic perspective illustration of an ink distribution molding.
FIG. 12 is an exploded perspective illustration showing the layers forming part of a laminated ink distribution structure according to the present invention.
FIG. 13 is a stepped sectional view from above of the structure depicted in FIGS. 9A and 9B ,
FIG. 14 is a stepped sectional view from below of the structure depicted in FIG. 13 .
FIG. 15 is a schematic perspective illustration of a first laminate layer.
FIG. 16 is a schematic perspective illustration of a second laminate layer.
FIG. 17 is a schematic perspective illustration of a third laminate layer.
FIG. 18 is a schematic perspective illustration of a fourth laminate layer.
FIG. 19 is a schematic perspective illustration of a fifth laminate layer.
FIG. 20 is a perspective view of the air valve molding
FIG. 21 is a rear perspective view of the right hand end of the platen
FIG. 22 is a rear perspective view of the left hand end of the platen
FIG. 23 is an exploded view of the platen
FIG. 24 is a transverse cross-sectional view of the platen
FIG. 25 is a front perspective view of the optical paper sensor arrangement
FIG. 26 is a schematic perspective illustration of a printhead assembly and ink lines attached to an ink reservoir cassette.
FIG. 27 is a partly exploded view of FIG. 26 .
DETAILED DESCRIPTION OF THE INVENTION
In FIGS. 1 to 3 of the accompanying drawings there is schematically depicted the core components of a print engine assembly, showing the general environment in which the laminated ink distribution structure of the present invention can be located. The print engine assembly includes a chassis 10 fabricated from pressed steel, aluminum, plastics or other rigid material. Chassis 10 is intended to be mounted within the body of a printer and serves to mount a printhead assembly 11 , a paper feed mechanism and other related components within the external plastics casing of a printer.
In general terms, the chassis 10 supports the printhead assembly 11 such that ink is ejected therefrom and onto a sheet of paper or other print medium being transported below the printhead then through exit slot 19 by the feed mechanism. The paper feed mechanism includes a feed roller 12 , feed idler rollers 13 , a platen generally designated as 14 , exit rollers 15 and a pin wheel assembly 16 , all driven by a stepper motor 17 . These paper feed components are mounted between a pair of bearing moldings 18 , which are in turn mounted to the chassis 10 at each respective end thereof.
A printhead assembly 11 is mounted to the chassis 10 by means of respective printhead spacers 20 mounted to the chassis 10 . The spacer moldings 20 increase the printhead assembly length to 220 mm allowing clearance on either side of 210 mm wide paper.
The printhead construction is shown generally in FIGS. 4 to 8 .
The printhead assembly 11 includes a printed circuit board (PCB) 21 having mounted thereon various electronic components including a 64 MB DRAM 22 , a PEC chip 23 , a QA chip connector 24 , a microcontroller 25 , and a dual motor driver chip 26 . The printhead is typically 203 mm long and has ten print chips 27 ( FIG. 13 ), each typically 21 mm long. These print chips 27 are each disposed at a slight angle to the longitudinal axis of the printhead (see FIG. 12 ), with a slight overlap between each print chip which enables continuous transmission of ink over the entire length of the array. Each print chip 27 is electronically connected to an end of one of the tape automated bond (TAB) films 28 , the other end of which is maintained in electrical contact with the undersurface of the printed circuit board 21 by means of a TAB film backing pad 29 .
The preferred print chip construction is as described in U.S. Pat. No. 6,044,646 by the present applicant. Each such print chip 27 is approximately 21 mm long, less than 1 mm wide and about 0.3 mm high, and has on its lower surface thousands of MEMS inkjet nozzles 30 , shown schematically in FIGS. 9A and 9B , arranged generally in six lines—one for each ink type to be applied. Each line of nozzles may follow a staggered pattern to allow closer dot spacing. Six corresponding lines of ink passages 31 extend through from the rear of the print chip to transport ink to the rear of each nozzle. To protect the delicate nozzles on the surface of the print chip each print chip has a nozzle guard 43 , best seen in FIG. 9A , with microapertures 44 aligned with the nozzles 30 , so that the ink drops ejected at high speed from the nozzles pass through these microapertures to be deposited on the paper passing over the platen 14 .
Ink is delivered to the print chips via a distribution molding 35 and laminated stack 36 arrangement forming part of the printhead 11 . Ink from an ink cassette 93 ( FIGS. 26 and 27 ) is relayed via individual ink hoses 94 to individual ink inlet ports 34 integrally molded with a plastics duct cover 39 which forms a lid over the plastics distribution molding 35 . The distribution molding 35 includes six individual longitudinal ink ducts 40 and an air duct 41 which extend throughout the length of the array. Ink is transferred from the inlet ports 34 to respective ink ducts 40 via individual cross-flow ink channels 42 , as best seen with reference to FIG. 7 . It should be noted in this regard that although there are six ducts depicted, a different number of ducts might be provided. Six ducts are suitable for a printer capable of printing four color process (CMYK) as well as infra-red ink and fixative.
Air is delivered to the air duct 41 via an air inlet port 61 , to supply air to each print chip 27 , as described later with reference to FIGS. 6 to 8 , 20 and 21 .
Situated within a longitudinally extending stack recess 45 formed in the underside of distribution molding 35 are a number of laminated layers forming a laminated ink distribution stack 36 . The layers of the laminate are typically formed of micro-molded plastics material. The TAB film 28 extends from the undersurface of the printhead PCB 21 , around the rear of the distribution molding 35 to be received within a respective TAB film recess 46 ( FIG. 21 ), a number of which are situated along a chip housing layer 47 of the laminated stack 36 . The TAB film relays electrical signals from the printed circuit board 21 to individual print chips 27 supported by the laminated structure.
The distribution molding, laminated stack 36 and associated components are best described with reference to FIGS. 7 to 19 .
FIG. 10 depicts the distribution molding cover 39 formed as a plastics molding and including a number of positioning spigots 48 which serve to locate the upper printhead cover 49 thereon.
As shown in FIG. 7 , an ink transfer port 50 connects one of the ink ducts 39 (the fourth duct from the left) down to one of six lower ink ducts or transitional ducts 51 in the underside of the distribution molding. All of the ink ducts 40 have corresponding transfer ports 50 communicating with respective ones of the transitional ducts 51 . The transitional ducts 51 are parallel with each other but angled acutely with respect to the ink ducts 40 so as to line up with the rows of ink holes of the first layer 52 of the laminated stack 36 to be described below.
The first layer 52 incorporates twenty four individual ink holes 53 for each of ten print chips 27 . That is, where ten such print chips are provided, the first layer 52 includes two hundred and forty ink holes 53 . The first layer 52 also includes a row of air holes 54 alongside one longitudinal edge thereof.
The individual groups of twenty four ink holes 53 are formed generally in a rectangular array with aligned rows of ink holes. Each row of four ink holes is aligned with a transitional duct 51 and is parallel to a respective print chip.
The undersurface of the first layer 52 includes underside recesses 55 . Each recess 55 communicates with one of the ink holes of the two centre-most rows of four holes 53 (considered in the direction transversely across the layer 52 ). That is, holes 53 a ( FIG. 13 ) deliver ink to the right hand recess 55 a shown in FIG. 14 , whereas the holes 53 b deliver ink to the left most underside recesses 55 b shown in FIG. 14 .
The second layer 56 includes a pair of slots 57 , each receiving ink from one of the underside recesses 55 of the first layer.
The second layer 56 also includes ink holes 53 which are aligned with the outer two sets of ink holes 53 of the first layer 52 . That is, ink passing through the outer sixteen ink holes 53 of the first layer 52 for each print chip pass directly through corresponding holes 53 passing through the second layer 56 .
The underside of the second layer 56 has formed therein a number of transversely extending channels 58 to relay ink passing through ink holes 53 c and 53 d toward the centre. These channels extend to align with a pair of slots 59 formed through a third layer 60 of the laminate. It should be noted in this regard that the third layer 60 of the laminate includes four slots 59 corresponding with each print chip, with two inner slots being aligned with the pair of slots formed in the second layer 56 and outer slots between which the inner slots reside.
The third layer 60 also includes an array of air holes 54 aligned with the corresponding air hole arrays 54 provided in the first and second layers 52 and 56 .
The third layer 60 has only eight remaining ink holes 53 corresponding with each print chip. These outermost holes 53 are aligned with the outermost holes 53 provided in the first and second laminate layers. As shown in FIGS. 9A and 9B , the third layer 60 includes in its underside surface a transversely extending channel 61 corresponding to each hole 53 . These channels 61 deliver ink from the corresponding hole 53 to a position just outside the alignment of slots 59 therethrough.
As best seen in FIGS. 9A and 9B , the top three layers of the laminated stack 36 thus serve to direct the ink (shown by broken hatched lines in FIG. 9B ) from the more widely spaced ink ducts 40 of the distribution molding to slots aligned with the ink passages 31 through the upper surface of each print chip 27 .
As shown in FIG. 13 , which is a view from above the laminated stack, the slots 57 and 59 can in fact be comprised of discrete co-linear spaced slot segments.
The fourth layer 62 of the laminated stack 36 includes an array of ten chip-slots 65 each receiving the upper portion of a respective print chip 27 .
The fifth and final layer 64 also includes an array of chip-slots 65 which receive the chip and nozzle guard assembly 43 .
The TAB film 28 is sandwiched between the fourth and fifth layers 62 and 64 , one or both of which can be provided with recesses to accommodate the thickness of the TAB film.
The laminated stack is formed as a precision micro-molding, injection molded in an Acetal type material. It accommodates the array of print chips 27 with the TAB film already attached and mates with the cover molding 39 described earlier.
Rib details in the underside of the micro-molding provides support for the TAB film when they are bonded together. The TAB film forms the underside wall of the printhead module, as there is sufficient structural integrity between the pitch of the ribs to support a flexible film. The edges of the TAB film seal on the underside wall of the cover molding 39 . The chip is bonded onto one hundred micron wide ribs that run the length of the micro-molding, providing a final ink feed to the print nozzles.
The design of the micro-molding allow for a physical overlap of the print chips when they are butted in a line. Because the printhead chips now form a continuous strip with a generous tolerance, they can be adjusted digitally to produce a near perfect print pattern rather than relying on very close toleranced moldings and exotic materials to perform the same function. The pitch of the modules is typically 20.33 mm.
The individual layers of the laminated stack as well as the cover molding 39 and distribution molding can be glued or otherwise bonded together to provide a sealed unit. The ink paths can be sealed by a bonded transparent plastic film serving to indicate when inks are in the ink paths, so they can be fully capped off when the upper part of the adhesive film is folded over. Ink charging is then complete.
The four upper layers 52 , 56 , 60 , 62 of the laminated stack 36 have aligned air holes 54 which communicate with air passages 63 formed as channels formed in the bottom surface of the fourth layer 62 , as shown in FIGS. 9 b and 13 . These passages provide pressurised air to the space between the print chip surface and the nozzle guard 43 whilst the printer is in operation. Air from this pressurised zone passes through the micro-apertures 44 in the nozzle guard, thus preventing the build-up of any dust or unwanted contaminants at those apertures. This supply of pressurised air can be turned off to prevent ink drying on the nozzle surfaces during periods of non-use of the printer, control of this air supply being by means of the air valve assembly shown in FIGS. 6 to 8 , 20 and 21 .
With reference to FIGS. 6 to 8 , within the air duct 41 of the printhead there is located an air valve molding 66 formed as a channel with a series of apertures 67 in its base. The spacing of these apertures corresponds to air passages 68 formed in the base of the air duct 41 (see FIG. 6 ), the air valve molding being movable longitudinally within the air duct so that the apertures 67 can be brought into alignment with passages 68 to allow supply the pressurized air through the laminated stack to the cavity between the print chip and the nozzle guard, or moved out of alignment to close off the air supply. Compression springs 69 maintain a sealing inter-engagement of the bottom of the air valve molding 66 with the base of the air duct 41 to prevent leakage when the valve is closed.
The air valve molding 66 has a cam follower 70 extending from one end thereof, which engages an air valve cam surface 71 on an end cap 74 of the platen 14 so as to selectively move the air valve molding longitudinally within the air duct 41 according to the rotational positional of the multi-function platen 14 , which may be rotated between printing, capping and blotting positions depending on the operational status of the printer, as will be described below in more detail with reference to FIGS. 21 to 24 . When the platen 14 is in its rotational position for printing, the cam holds the air valve in its open position to supply air to the print chip surface, whereas when the platen is rotated to the non-printing position in which it caps off the micro-apertures of the nozzle guard, the cam moves the air valve molding to the valve closed position.
With reference to FIGS. 21 to 24 , the platen member 14 extends parallel to the printhead, supported by a rotary shaft 73 mounted in bearing molding 18 and rotatable by means of gear 79 (see FIG. 3 ). The shaft is provided with a right hand end cap 74 and left hand end cap 75 at respective ends, having cams 76 , 77 .
The platen member 14 has a platen surface 78 , a capping portion 80 and an exposed blotting portion 81 extending along its length, each separated by 120°. During printing, the platen member is rotated so that the platen surface 78 is positioned opposite the printhead so that the platen surface acts as a support for that portion of the paper being printed at the time. When the printer is not in use, the platen member is rotated so that the capping portion 80 contacts the bottom of the printhead, sealing in a locus surrounding the microapertures 44 . This, in combination with the closure of the air valve by means of the air valve arrangement when the platen 14 is in its capping position, maintains a closed atmosphere at the print nozzle surface. This serves to reduce evaporation of the ink solvent (usually water) and thus reduce drying of ink on the print nozzles while the printer is not in use.
The third function of the rotary platen member is as an ink blotter to receive ink from priming of the print nozzles at printer start up or maintenance operations of the printer. During this printer mode, the platen member 14 is rotated so that the exposed blotting portion 81 is located in the ink ejection path opposite the nozzle guard 43 . The exposed blotting portion 81 is an exposed part of a body of blotting material 82 inside the platen member 14 , so that the ink received on the exposed portion 81 is drawn into the body of the platen member.
Further details of the platen member construction may be seen from FIGS. 23 and 24 . The platen member consists generally of an extruded or molded hollow platen body 83 which forms the platen surface 78 and receives the shaped body of blotting material 82 of which a part projects through a longitudinal slot in the platen body to form the exposed blotting surface 81 . A flat portion 84 of the platen body 83 serves as a base for attachment of the capping member 80 , which consists of a capper housing 85 , a capper seal member 86 and a foam member 87 for contacting the nozzle guard 43 .
With reference again to FIG. 1 , each bearing molding 18 rides on a pair of vertical rails 101 . That is, the capping assembly is mounted to four vertical rails 101 enabling the assembly to move vertically. A spring 102 under either end of the capping assembly biases the assembly into a raised position, maintaining cams 76 , 77 in contact with the spacer projections 100 .
The printhead 11 is capped when not is use by the full-width capping member 80 using the elastomeric (or similar) seal 86 . In order to rotate the platen assembly 14 , the main roller drive motor is reversed. This brings a reversing gear into contact with the gear 79 on the end of the platen assembly and rotates it into one of its three functional positions, each separated by 120°.
The cams 76 , 77 on the platen end caps 74 , 75 co-operate with projections 100 on the respective printhead spacers 20 to control the spacing between the platen member and the printhead depending on the rotary position of the platen member. In this manner, the platen is moved away from the printhead during the transition between platen positions to provide sufficient clearance from the printhead and moved back to the appropriate distances for its respective paper support, capping and blotting functions.
In addition, the cam arrangement for the rotary platen provides a mechanism for fine adjustment of the distance between the platen surface and the printer nozzles by slight rotation of the platen 14 . This allows compensation of the nozzle-platen distance in response to the thickness of the paper or other material being printed, as detected by the optical paper thickness sensor arrangement illustrated in FIG. 25 .
The optical paper sensor includes an optical sensor 88 mounted on the lower surface of the PCB 21 and a sensor flag arrangement mounted on the arms 89 protruding from the distribution molding. The flag arrangement comprises a sensor flag member 90 mounted on a shaft 91 which is biased by torsion spring 92 . As paper enters the feed rollers, the lowermost portion of the flag member contacts the paper and rotates against the bias of the spring 92 by an amount dependent on the paper thickness. The optical sensor detects this movement of the flag member and the PCB responds to the detected paper thickness by causing compensatory rotation of the platen 14 to optimize the distance between the paper surface and the nozzles.
FIGS. 26 and 27 show attachment of the illustrated printhead assembly to a replaceable ink cassette 93 . Six different inks are supplied to the printhead through hoses 94 leading from an array of female ink valves 95 located inside the printer body. The replaceable cassette 93 containing a six compartment ink bladder and corresponding male valve array is inserted into the printer and mated to the valves 95 . The cassette also contains an air inlet 96 and air filter (not shown), and mates to the air intake connector 97 situated beside the ink valves, leading to the air pump 98 supplying filtered air to the printhead. A QA chip is included in the cassette. The QA chip meets with a contact 99 located between the ink valves 95 and air intake connector 96 in the printer as the cassette is inserted to provide communication to the QA chip connector 24 on the PCB. | A printhead assembly includes elongate, printhead integrated circuits having a plurality of micro-electromechanical ink ejection mechanisms configured to eject ink. An ink distribution assembly, to which the, or each, printhead integrated circuit can be mounted, defines a plurality of converging ink passages in fluid communication with respective ink ejection mechanisms. An ink reservoir is mounted to the ink distribution assembly and defines a plurality of parallel ink channels in fluid communication with respective groups of the passages, such that inks can be fed from the channels to respective groups of the ink ejection mechanisms. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to an internal combustion engine for a vehicle, and more particularly, to an internal combustion engine improved in the charging efficiency of an air-fuel mixture to each cylinder of the engine.
In a conventional four-cycle internal combustion engine for an automobile comprises one intake valve and one exhaust valve for each cylinder or combustion chamber. In order to enhance the output performance of the engine of this type, the charging efficiency of an air-fuel mixture to the combustion chambers and the discharging efficiency of exhaust gases therefrom must be improved. To attain this, an intake port and an exhaust port of each combustion chamber, adapted to be opened and closed by means of the intake valve and the exhaust valve, in each engine cylinder, should preferably be maximized in size. Usually, however, the intake and exhaust ports, as well as the bore of the cylinder, are circular in shape, so that their maximum permissible size is restricted by the diameter of the cylinder bore. Accordingly, there are some conventional engines in which the number of intake and exhaust ports for each cylinder is increased in order that the total opening areas of the ports are large enough even though the opening area of each port is reduced.
One such conventional engine comprises, for example, two intake ports and two exhaust ports for each cylinder and twin camshafts. The engine of this type, having two intake valves and two exhaust valves for opening and closing the intake and exhaust ports, respectively, are called a four-valve engine.
As compared with the two-valve engine, having one intake valve and one exhaust valve for each cylinder, the four-valve engine can enjoy improved output performance, higher rotating speed due to reduction of the weight of valve drive mechanisms, and less mechanical loss. Also, the low- and medium-speed torque performance can be improved by controlling the valve timing. Thus, the four-valve engine has started to be used as a practical engine, as well as a high-output engine for a sports car or the like.
There has recently been a demand for an engine whose output can be made higher than the four-valve engine, and in which the amount of fuel supply to the combustion chambers can be controlled in accordance with the operating conditions of the engine.
In developing the engine of this type, the engine output may be further improved by increasing the number of intake valves used in the engine to five. In this case, the developed engine is a five-valve engine. In order to control the fuel supply to the combustion chambers in accordance with the operating conditions of the engine, moreover, the operation of fuel injection valves, which are used to inject fuel directly into an intake manifold connecting with the individual combustion chambers, may be controlled by means of an electronic control device. The electronic control device, which includes a programmable electronic circuit such as a microcomputer, serves to determine the operating conditions of the engine in accordance with signals from various sensors, and control the operation of the fuel injection valve so that the air-fuel mixture can enjoy an optimum air-fuel ratio depending on the operating conditions.
In a specific example of the aforementioned internal combustion engine, the lower-course region of the inside of an intake passage leading to each cylinder is divided into three branch intake passages, which are connected individually to intake ports adapted to cooperate with their corresponding intake valves, and one fuel injection valve is disposed in a region on the upper-course side of the branch intake passages of each intake passage.
FIGS. 1 and 2 show a conventional one-flow injection valve 10 which has one jet 10a, and is used in the internal combustion engine of the aforesaid type. In the injection valve 10, an atomized fuel flow 11 injected from the jet 10a is supplied to three intake ports, including a central intake port 13 and two outside intake ports 12 and 14.
FIGS. 3 and 4 show a conventional two-flow injection valve 15 which has two jets 15a and 15b. In the injection valve 15, two atomized fuel flows 16 and 17 are injected from jets 15a and 15b, respectively. The one fuel flow 16 is supplied to the one outside intake port and one half of the central intake port 13, while the other fuel flow 17 is supplied to the other outside intake port 14 and the other half of the central intake port 13.
In the engine having the fuel injection valves of this type, however, fuel injected from each fuel injection valve has the form of one or two atomized fuel flows which radially spread toward the branch intake passages. It is difficult, therefore, to distribute the atomized fuel flow or flows uniformly to the three branch intake passages. Thus, air-fuel mixtures fed individually through the intake ports into each combustion chamber are different in fuel concentration. In consequence, the fuel concentration distribution in the combustion chambers is uneven, so that the fuel cannot undergo perfect combustion.
FIGS. 5 to 7 show a free-flow injection valve 18, disclosed in Japanese Utility Model Disclosure No. 61-186726, which has three jets 18a, 18b and 18c. The jets 18a, 18b and 18c of the injection valve 18, which serve to inject fuel toward intake ports 12, 13 and 14, respectively, are arranged in a straight line, and open so that the central jet 18b enjoys the largest injection quantity. Having different opening areas, the jets 18a to 18c are intended positively to cause unevenness in the fuel concentration distribution. In the engine disclosed in Japanese Utility Model Disclosure No. 61-186726, an intake control valve (not shown) is disposed in the intake port 12. The control valve is opened and closed during high- and low-load operations of the engine, respectively, so that the low-load combustion performance is improved. When the intake control valve is closed, however, a greater amount of fuel adheres to the wall surface near the intake port in which the control valve is located, so that the air-fuel ratio of the air-fuel mixture introduced through the central intake port 13 is excessively fuel-rich. Also when the intake control valve is open, only the air-fuel mixture from the central intake port 13 is excessively fuel-rich.
The fuel supplied to the combustion chambers is also utilized for cooling the intake valves. If the atomized fuel flows passing through the individual branch intake passages are different in fuel concentration, however, the intake valves cannot be cooled uniformly.
As mentioned before, moreover, the atomized fuel flows from each fuel injection valve radially spread toward the branch intake passages, so that the amount of fuel adhering to the respective inner walls of the branch passages naturally increases. Accordingly, the necessary fuel amount cannot be secured for acceleration. If the fuel supply is interrupted at the time of deceleration, on the other hand, the fuel adhering to the wall surface flows into the combustion chambers, thus exerting a bad influence on the responsiveness of the engine.
OBJECT AND SUMMARY OF THE INVENTION
The object of the present invention is to provide an internal combustion engine for a vehicle, which has three intake valves, i.e., three intake ports, for each cylinder so that air-fuel mixtures of uniform fuel concentration can be fed into a combustion chamber through the individual intake ports, thus ensuring improvement in the fuel combustion efficiency, the cooling efficiency of the intake valves, and the responsiveness of the engine.
The above object of the present invention is achieved by an internal combustion engine for a vehicle, which comprises port means defining three intake ports opening into a combustion chamber; an intake valve unit for opening and closing the three intake ports; passage means defining an intake passage connected to the combustion chamber through the three intake ports; partition wall means for dividing the lower-course region of the intake passage on the intake-port side into three separate branch intake passages leading to the individual intake ports; and a fuel injection valve disposed on the upper-course side of the branch intake passages of the intake passage and adapted to inject a fuel into the intake passage, the fuel injection valve including an injection end face fronting the inside of the intake passage and three jets through which atomized fuel flows of substantially equal quantities are injected toward the branch intake passages corresponding thereto, the jets being formed in the injection end face.
According to the internal combustion engine described above, the fuel injection valve is provided with the three jets, and the atomized fuel flows of equal quantities are independently injected through the jets toward their corresponding intake ports. Therefore, the amounts of fuel introduced through the individual intake ports into the combustion chamber are also equal. Thus, the distribution of the fuel fed into the combustion chamber is even, so that the combustion efficiency is improved, the output and torque of the engine can be increased, and production of soot in exhaust gas can be prevented. Since the fuel distribution in the combustion chamber can be made uniform, the start of the engine, especially at low temperature, can be facilitated, and a stable operating state can be obtained. Further, the amounts of fuel used to cool intake valves for opening and closing the individual intake ports are also equal, so that the intake valves can enjoy the same cooling effect.
Since the fuel injection valve produces the independent atomized fuel flows bound for the individual intake ports, the amount of fuel adhering to the intake passage, especially the inner walls of the branch intake passages, can be effectively restricted. Thus, the responsiveness of the engine can be improved.
According to the present invention, furthermore, the intake ports are three in number, so that each intake valve for opening and closing each corresponding intake port, in the intake valve unit, can be reduced in size, and hence, in weight. In consequence, the load acting on drive mechanisms for the intake valves can be reduced, so that the engine speed can be increased, and the valve timing for each intake valve can be controlled with high accuracy.
The above and other objects, features, and advantages of the invention will be more apparent from the ensuing detailed description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a horizontal sectional view showing part of an intake pipe leading to one cylinder of a prior art internal combustion engine and a fuel injection valve of a one-flow type;
FIG. 2 is a vertical sectional view taken along line II--II of FIG. 1;
FIG. 3 is a horizontal sectional view showing part of an intake pipe leading to one cylinder of another prior art internal combustion engine and a fuel injection valve of a two-flow type;
FIG. 4 is a vertical sectional view taken along line IV--IV of FIG. 3;
FIG. 5 is a horizontal sectional view showing part of an intake pipe leading to one cylinder of still another prior art internal combustion engine and a fuel injection valve of a three-flow type;
FIG. 6 is an enlarged sectional view of the three-flow injection valve shown in FIG. 5;
FIG. 7 is a front view showing jets of the three-flow injection valve shown in FIG. 5;
FIG. 8 is a sectional view schematically showing part of an internal combustion engine for a vehicle according to an embodiment of the present invention;
FIG. 9 is a horizontal sectional view showing part of an intake pipe leading to one cylinder of the engine of FIG. 8 and a fuel injection valve;
FIG. 10 is a vertical sectional view taken along line X--X of FIG. 9;
FIG. 11 is a sectional view taken along line XI--XI of FIG. 10; and
FIG. 12 is a front view showing jets of the injection valve shown in FIG. 9.
DETAILED DESCRIPTION
Referring now to FIG. 8, there is schematically shown a section of the top portion of an internal combustion engine for a vehicle. This engine has a cylinder block 1 in which are defined cylinder bores as many as cylinders of the engine. A piston 2 is fitted in each cylinder bore, and is connected to a crankshaft (not shown) by means of a connecting rod 3. In FIG. 8, a cylinder head 6 is disposed on the top of the cylinder block 1, and a combustion chamber 8 is defined between the cylinder head 6 and the piston 2, inside each cylinder bore.
The cylinder head 6 has three intake ports 20 of the same diameter and two exhaust ports 22 for each combustion chamber 8. These ports 20 and 22 open individually into the combustion chamber 8. FIG. 8 shows only each one of the intake ports and the exhaust ports for simplicity of illustration. Each intake port 20 is adapted to be opened and closed by means of an intake valve 24 which is formed of a poppet valve. Like the intake port 20, each exhaust port 22 is adapted to be opened and closed by means of an exhaust valve 26 formed of a poppet valve. As seen from Fig. 8, the intake valve 24 and the exhaust valve 26 are operated by means of a double overhead camshaft system. Thus, a single camshaft 28 is provided for the intake valve 24. As the camshaft 28 rotates, a cam 30 on the camshaft 28 and a rocker arm 32 cooperate with each other to actuate each corresponding intake valve 24. Another camshaft 34 is provided for the exhaust valve 26. As the camshaft 34 rotates, as in the case of the intake valve 24, a cam 36 and a rocker arm 38 cooperate with each other to actuate each corresponding exhaust valve 26. It is to be noted that the three intake valves 24 for each combustion chamber 8 are operated in synchronism with one another, and the two exhaust valves 26 for each chamber 8 are also operated synchronously with each other.
The three intake ports 20 for each combustion chamber 8 are connected to one intake pipe 40 of an intake manifold 38 through an internal passage 42 defined inside the cylinder head 6. Thus, the intake pipe 40 and the internal passage 42 constitute part of an intake passage through which an air-fuel mixture is introduced into the combustion chamber 8. The intake manifold 38 is connected to an air cleaner (not shown) through a surge tank 44. Meanwhile, the two exhaust ports 22 of each combustion chamber 8 are connected to an exhaust passage 46. The engine of FIG. 8 is provided with a turbocharger 48 which is driven by means of exhaust gas flowing through the exhaust passage 46. The turbocharger 48 has a function to pressurize air supplied to the intake manifold 38. An ignition plug is not shown in FIG. 8.
The internal passages 42, which communicate individually with the combustion chambers 8, have the same construction, so that only one of them will be described below.
As shown in FIG. 9, the internal passage 42, which constitutes part of the intake passage, includes three independent branch intake passages 50, 52 and 54 at its lower-course region on the side of the three intake ports 20. The passages 50, 52 and 54 are connected to their corresponding intake ports 20. These branch intake passages are substantially circular in cross-sectional shape, and have substantially the same cross-sectional area.
In this embodiment, as seen from FIGS. 9 and 10, the central branch intake passage 52, among the three branch passages 50, 52 and 54, is bent toward the piston 2 with a higher degree of curvature than the outside branch passages 50 and 54, and is then led to its corresponding intake port 20. Thus, among the three associated intake ports 20, the central intake port 20 (as in FIG. 9) which is connected to the branch intake passage 52 is situated closer to the piston 2 than the two others are. Also, the two other intake ports 20 are positioned at equal distances from the piston 2. In other words, the center of the central intake port 20 is situated within a plane which contains the center line of the internal passage 42 and extends along the axis of the piston 12, while the respective centers of the two other intake ports 20 are positioned at equal distances from that plane. The intake valves 24 are not shown in FIGS. 9 and 10.
Referring again to FIG. 8, the intake pipe 40, which constitutes part of each intake passage, is provided with one fuel injection valve 56. The valve 56 is attached to that region of the intake pipe 40 which is situated close to the internal passage 42 so that the front end of the valve 56 faces the passage 42. More specifically, the fuel injection valve 56 is disposed so that its axis is situated within the aforesaid plane and extends along the internal passage 42. The valve 56 is connected to a fuel pump (not shown), and the injection quantity of fuel injected from the valve 56 is controlled by means of an electronic control device (not shown) which includes a microcomputer.
As shown in FIG. 12, the fuel injection valve 56 has three jets 58a, 58b and 58c in its front end face which projects into the intake pipe 40. Among these jets, the jets 58a and 58c are deviated upward (as in FIGS. 10 and 12) from the center of the front end face of the fuel injection valve 56, when the valve 56 is in the aforementioned mounted position, and are arranged on the circumference of the same circle. On the other hand, the remaining jet 58b is situated below and between the jets 58a and 58c, as shown in FIGS. 10 and 12. Thus, the three jets 58a, 58b and 58c are situated individually corresponding to the three vertexes of an isosceles triangle whose base corresponds to a segment connecting the jets 58a and 58c. The jets 58a, 58b and 58c are associated with the branch intake passages 50, 52 and 54, respectively. Accordingly, the jet 58b is allocated to the central intake port 20, while the jets 58a and 58c are allocated individually to the two outside intake ports 20. The jets 58a, 58b and 58c have substantially the same diameter, so that substantially the same quantity of fuel is injected from each jet when the fuel is injected from the fuel injection valve 56. The arrangement of the jets is not limited to the aforesaid configuration, and all the three jets may be arranged on the circumference of the same circle.
When the fuel is injected from the fuel injection valve 56, it flows in the form of three atomized fuel flows Fa, Fb and Fc from the jets 58a, 58b and 58c toward their corresponding intake ports 20. Preferably, the respective axes of the fuel flows Fa, Fb and Fc are located so as to pass diverging inlets 50a, 52b and 54c of their corresponding branch intake passages 50, 52 and 54, more specifically, centers Ca, Cb and Cc of the inlets, the inlets being situated within a plane P which is perpendicular to the axis of the fuel injection valve 56. The plane P contains the respective tip ends of two partition walls 60 and 62 which define the three branch intake passages. Hereinafter, the plane P will be referred to as a formation plane for the branch intake passages.
In this embodiment, the diverging inlets 50a and 54c, among the three inlets on the formation plane P, are situated on the same level with one another, with respect to the combustion chamber 8 which is located on the lower side of FIG. 11. On the other hand, the diverging inlet 52b is situated on a level below that of the inlets 50a and 54c.
As described above, the best situation can be established if the axes of the atomized fuel flows Fa, Fb and Fc from the fuel injection valve 56 pass the centers Ca, Cb and Cc of the diverging inlets 50a, 52b and 54c, respectively. Practically, however, it is difficult to effect such an arrangement, so that the axes of the fuel flows Fa, Fb and Fc are located so as to pass regions near the centers Ca, Cb and Cc of their corresponding inlets 50a, 52b and 54c.
As mentioned before, the central branch intake passage 52, among the three branch passages, is bent toward the piston 2 with a higher degree of curvature than the outside branch passages 50 and 54, as shown in FIG. 10. Accordingly, the atomized fuel flow Fb in the branch intake passage 52 strikes against the inner wall of the passage 52 at a higher rate than the atomized fuel flows Fa and Fc in the other branch intake passages 50 and 54. Thus, a greater amount of fuel adheres to the inner wall of the passage 52 than to those of the passages 50 and 54. In order to avoid such an awkward situation, the target point at which the axis of the jet 58b of the fuel injection valve 56, i.e., the axis of the atomized fuel flow Fb, crosses the diverging inlet 52b of the branch intake passage 52 is preferably set as follows.
Now let it be assumed that the points at which the respective axes of the atomized fuel flows Fa, Fb and Fc from the fuel injection valve 56 actually cross the diverging inlets 50a, 52b and 54c of their corresponding branch intake passages 50, 52 and 54, within the formation plane P, are fa, fb and fc, respectively, and that the center points of the three intake ports 20 are Da, Db and Dc, respectively, as shown in FIG. 11. Thereupon, the axis of the atomized fuel flow Fb is inclined so as to extend on the side of the center point Db, with respect to a segment of line connecting the center points Da and Dc and extending parallel to the formation plane P, as shown in FIG. 9. Also, the point fb at which the axis of the atomized fuel flow Fb crosses the diverging inlet 52b of the branch intake passage 52 is situated on the side of the center point Db or on the side of the piston 2, with respect to a segment connecting the points fa and fc, as shown in FIG. 11.
More specifically, the atomized fuel flow Fb and the point fb are directed or positioned so that the axis of the flow Fb passes a point on the side of the inside portion (with respect to the curvature) of the wall surface of the branch intake passage 52, with respect to the center Cb of the diverging inlet 52b. As shown in FIG. 10, moreover, the curvature of the two other branch intake passages 50 and 54 is gentler than that of the passage 52. Since these three branch intake passages are bent in the same direction, however, the axes of the atomized fuel flows Fa and Fc are preferably arranged so as to pass the points fa and fc, respectively, on the side of the piston 2, with respect to the respective centers Ca and Cc of the diverging inlets 50a and 54c, as shown in FIG. 11. If the branch intake passages 50 and 54 are bent outward (as in FIG. 9) from the branch intake passage 52 and toward the segment connecting the centers Da and Dc, the points fa and fc at which the atomized fuel flows Fa and Fc cross the diverging inlets 50a and 54c, respectively, are preferably shifted outward with respect the passage 52, as shown in FIG. 11.
As seen from FIG. 9, moreover, the three atomized fuel flows Fa, Fb and Fc from the fuel injection valve 56 are radially spread toward the branch intake passages 50, 52 and 54. In this arrangement, all the regions at which the atomized fuel flows Fa, Fb and Fc cross the diverging inlets 50a, 52b, and 54c, respectively, are contained in their corresponding diverging inlets. Therefore, each atomized fuel flow can never enter the branch intake passage adjacent to its corresponding one.
In the engine described above, the fuel injection valve 56 is opened at predetermined time intervals and for a predetermined period of time to effect injection of an optimum quantity of fuel, in accordance with the operating conditions of the engine determined by means of the electronic control device. When the fuel injection valve 56 is opened, the three atomized fuel flows Fa, Fb and Fc of substantially equal quantities are simultaneously injected from the jets 58a, 58b and 58c, respectively. The fuel flows Fa, Fb and Fc pass through their corresponding branch intake passages 50, 52 and 54 while spreading radially. Thus, these fuel flows enter the combustion chamber 8 after passing through their corresponding intake ports 20 only. | An internal combustion engine for a vehicle comprising three intake ports for each combustion chamber, three intake valves for opening and closing the intake ports, and an intake passage connected to the combustion chamber through the three intake ports, the lower-course region of the intake passage on the intake-port side being divided into three separate branch intake passages leading to the individual intake ports. The internal combustion engine according to the present invention further comprises a fuel injection valve disposed on the upper-course side of the branch intake passages of the intake passage, the injection valve having three jets through which atomized fuel flows of substantially equal quantities are injected toward their corresponding branch intake passages. | 5 |
[0001] The invention relates to a cable actuator comprising a screw/nut assembly, the nut of which is mobile in translation, and is coupled to a pair of cables.
BACKGROUND OF THE INVENTION
[0002] Cable actuators are known comprising a screw/nut assembly, the screw of which is rotated by an electric motor, and the nut of which is mobile in translation. The mobile element is coupled to one or more cables, in order to exert traction on the cables.
[0003] A cable actuator of this type is known from document FR2809464, wherein the element in translation is the screw, whereas the nut is mobile in translation under the action of a motor. The cable passes into a bore in the screw, and is coupled by means of a tolerant fastener to the misalignments of the cable.
[0004] In certain applications, in particular in robotic applications, the size of the actuator is highly critical, and it is important to ensure that this size is as small as possible.
[0005] Cable actuators are known comprising a screw which is fitted such as to rotate, and is driven by an electric motor, with a nut cooperating with the screw and being associated with anti-rotation means, such that rotation of the screw under the action of the motor gives rise to axial displacement of the nut, and two parallel cables which are coupled to the nut on both sides of it.
[0006] For the same course, this device makes it possible to reduce the size of the cable actuator. In fact, in the known cable actuators, in which the cable(s) is/are coupled to the screw which is displaced, the screw is designed to extend from both sides of the actuator. Thus, the general size would be at least 2C+L, where C is the course of the actuator, and L is the size of the nut. In the actuator according to the invention, this minimum size is now only C+L.
OBJECT OF THE INVENTION
[0007] The object of the invention is to propose a cable actuator of the aforementioned type, which is tolerant to the various displacements and deformations which can interfere with its operation.
SUMMARY OF THE INVENTION
[0008] In order to achieve this objective, according to the invention a cable actuator is proposed comprising a screw which is fitted such as to rotate and is driven by an electric motor, with a nut cooperating with the screw and being associated with anti-rotation means, such that rotation of the screw under the action of the motor gives rise to axial displacement of the nut, and two parallel cables which are coupled to the nut on both sides of it, wherein, according to the invention, the cables are connected to an anchorage unit which is interposed between the cables and the nut, the anchorage unit being coupled to the nut, so as to permit relative movement between the nut and the anchorage unit. Thus, any misalignments of the cables are absorbed by movement of the anchorage unit, without subjecting the nut to stress.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention will be better understood by reading the following description of various embodiments of it, provided with reference to the figures of the accompanying drawings, among which:
[0010] FIG. 1 is a partial view in perspective of a cable actuator according to a particular embodiment of the invention;
[0011] FIGS. 2A and 2B are operating diagrams of the cable actuator in FIG. 1 , the nut being shown in the two end axial positions;
[0012] FIG. 3 is a partial view in perspective of an actuator according to a particular embodiment, the nut of which is equipped with a pivoting anchorage unit;
[0013] FIGS. 4A and 4B are lateral views according to two perpendicular orientations, illustrating an actuator with an anchorage unit according to another particular embodiment, illustrating two situations of misalignment of the cables;
[0014] FIGS. 5A and 5B are lateral views according to two perpendicular orientations, illustrating an actuator with an anchorage unit according to another particular embodiment, illustrating two situations of misalignment of the cables;
[0015] FIG. 6 is a schematic representation in perspective of another particular embodiment of a cable actuator according to the invention;
[0016] FIG. 7 is a detailed view in perspective of a detail of the embodiment in FIG. 6 ;
[0017] FIG. 8 is a schematic representation in perspective of another particular embodiment of a cable actuator according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] With reference to FIG. 1 , the cable actuator according to the invention comprises a chassis 1 on which a screw 2 is fitted so as to turn according to an axis X, whilst being rotated, in this case by an electric motor 3 . A nut 4 cooperates with the screw 2 , and is associated with an anti-rotation device 5 comprising two arms 6 which extend on both sides of the nut 4 , in order to support rollers 7 (only one can be seen in this case), which are fitted so as to turn according to an axis Y at right-angles to the axis X. The rollers 7 are engaged in longitudinal slots 8 which are provided in the chassis, and extend parallel to the axis X. The axis Y passes substantially into the center of the nut 4 . Thus, the nut is displaced axially under the effect of the rotation of the screw, without turning around the axis X. However, angular deviations are permitted around the axis Y, but also around an axis Z which is at right-angles to the axes X and Y.
[0019] The nut 4 comprises means 9 for coupling of two cables 10 a, 10 b which extend on both sides of the nut 4 , parallel to the axis X. In this case, the coupling means comprise two double flanges (only one can be seen in this case) which extend on both sides of the nut 4 .
[0020] As illustrated in FIGS. 2A and 2B , the cables 10 a and 10 b are each wound around a pulley 11 , the two pulleys 11 being integral with the same shaft 12 which is fitted such as to rotate according to an axis parallel to the axis Z. The shaft 12 is thus rotated once traction is exerted on the cables by displacement of the nut 4 . In a manner known per se, the cables 10 a and 10 b are kept taut, for example by placing the cables in a loop between two pulleys (as in document FR2809464), or, if only a one-way action is required, by means of a tension spring.
[0021] Various causes can introduce disturbances which give rise to dissymmetry in the traction of the two cables 10 . In particular, the shaft 12 may not turn around an axis which is perfectly parallel to the axis Z, and can be subjected to axial or transverse offsettings. Similarly, it is known that if a ball screw or roller screw is used, the nut is liable to oscillate around a transverse axis, which is or is not included on the plane defined by the pair of cables (in particular, if the actuator is equipped with an anti-rotation device, such as the one shown in FIG. 1 , the nut will oscillate around the axis Y), which will naturally induce dissymmetries in the traction of the cables 10 a, 10 b.
[0022] In order to absorb these disturbances, and according to the invention, the nut 4 is equipped with an anchorage unit to which the cables are coupled directly, the anchorage unit being integral with the nut whilst being mobile relative to the latter, in order to absorb these disturbances, and ensure homogeneous traction of the two cables.
[0023] According to a particular embodiment illustrated in FIG. 3 , in this case the anchorage unit comprises a frame 20 which is fitted so as to pivot on the nut 4 according to the axis Y. The frame 20 comprises pivots 21 which are fitted so as to pivot on the frame around the axis Z (when the frame is straight as shown here). The cables 10 a and 10 b are coupled directly to the pivots 21 . Thus, the nut is free to oscillate around the axis Y without however giving rise to imbalance in the traction of the cables 10 a, 10 b.
[0024] As a variant, it would be possible to couple the cables directly on the frame 20 , with the natural flexibility of the cables absorbing any rotation around the axis Z.
[0025] According to another particular embodiment illustrated in FIGS. 4A and 4B , the nut is once more associated with a frame 30 to which the cables 10 a and 10 b are coupled. However, the frame 30 is no longer fitted so as to pivot on the nut 4 , but is suspended on the nut by means of two rigid connecting rods 31 with ball ends. The connecting rods 31 extend on both sides of the nut 4 , the connecting rods preferably being coupled to the latter at coupling points which are symmetrical relative to the axis X (and are on the axis Y in FIG. 4 a ). The cables 10 a and 10 b are coupled directly to the frame 30 at two symmetrical points (according to the axis Z in FIG. 4B ). The two figures show how a frame 30 of this type makes it possible to absorb offsetting according to the axis Y of the axis of rotation of the shaft 12 ( FIG. 4A ), and offsetting of this same axis of rotation according to the axis Z ( FIG. 4B ). Angular offsetting of the said axis of rotation around the axis X or around the axis Y would be absorbed in the same manner by the mobility of the frame 31 .
[0026] According to yet another embodiment illustrated in FIGS. 5A and 5B , the frame 40 is now suspended on the nut by means of two naturally flexible portions of cable 41 .
[0027] These portions of cable 41 can be connected simply to the nut and to the frame, without a ball connection. For example, their ends can be secured directly on the nut and on the frame, or form a loop around a spindle.
[0028] In the embodiment represented in FIG. 6 , the nut is connected rigidly (in this case by welding) to a frame 50 with a square form comprising bores with references 51 to 54 at each of its corners. Two square frames 60 and 70 each comprising a central orifice 61 , 71 for passage of the screw 2 extending on both sides of the frame 50 . At each of their corners, the frames 60 and 70 comprise respective bores with the references 62 to 65 and 72 to 75 . The cable 10 a and the counterpart cable 10 b are wound around pulleys 11 and extend through bores in the frames 50 , 60 and 70 . As shown in detail in FIG. 7 , a first strand 80 of the cable 10 a passes through the bore 51 , extends on the first face 55 of the frame 50 whilst running along the edge 56 , then passes through the bore 52 , and extends on the second face 57 of the frame 50 whilst running along the edge 56 , then passes once more through the bore 51 . The first strand 80 of the cable 10 a then carries out a dead turn on the frame 50 and secures the cable 10 a to the nut 104 . The first strand 80 of the cable 10 a extends as far as the frame 60 , and carries out a dead turn on the latter through bores 62 and 63 , in order to exit through the bore 62 , and be wound around the pulley 111 . The second strand 81 of the cable 10 a extends parallel to the first strand 80 as far as the frame 60 , and then carries out a dead turn on the latter through the bores 63 and 62 in order to exit through the bore 63 . The second strand 81 then carries out a dead turn on the frame 50 through the bores 52 and 51 , in order to exit through the bore 52 . The second strand 81 then engages in the bore in the frame 70 , and carries out a dead turn on the frame 70 through the bores 73 and 72 , in order to exit once more through the bore 73 , and be wound around the pulley 11 . The second strand 81 is then connected to the first strand 80 , and carries out a dead turn on the frame 70 through bores 72 and 73 , in order to exit through the bore 73 and join once more the first strand 80 which is engaged through the bore 51 in the frame 50 . The counterpart cable 10 b follows a similar path through the bores 53 , 54 of the frame 50 , 64 , 65 of the frame 60 , 74 and 75 of the frame 70 .
[0029] The cables 10 a and 10 b are thus connected to the nut 4 by an anchorage unit comprising the frames 60 and 70 and the cable strands 80 , 81 . The frames 60 and 70 are suspended on the nut 4 by the cable strands 80 and 81 (which play the same part as the connecting rods 31 and the portions of cable 41 of the embodiments previously described) whilst being mobile relative to the nut.
[0030] The blocking of the cables by means of dead turns is particularly useful when using cables made of synthetic material, in particular polyaramide strings, the crimping of which on the nut 104 is difficult to carry out. It will be appreciated that the use of dead turns in order to render the cables 10 a and 10 b integral with the nut (via the frame 50 ) as well as with the anchorage units (in this case the frames 60 and 70 ) is not limited to single dead turns, and the blocking effect can be reinforced by carrying out a plurality of dead turns by passing the cable several times through the same pair of bores.
[0031] According to another particular embodiment represented in FIG. 8 , the transmission by the cables 10 a and 10 b is carried out by means of a single cable loop 90 , the two strands of which, which form the cables 10 a and 10 b, are represented in lines with different thicknesses in order to facilitate understanding. This effect is obtained by modifying the embodiment of the dead turns on the frame 50 . The first strand 91 of the cable 90 (corresponding to the first strand 80 of the embodiment in FIG. 6 ) is engaged through the bore 52 in the frame 50 , and extends on the first face 55 of the frame 50 , whilst running along an edge adjacent to the edge 56 , it then passes through the bore 53 and extends on the second face 57 of the frame 50 , whilst running along an edge 58 of the frame 50 parallel to the edge 56 , then passes through the bore 54 , before being engaged through the bore 65 in the frame 60 . The strand 91 then extends between the bore 65 and the bore 64 , exits once more via the bore 64 , and passes above the edge of the frame 60 in order to be wound around the pulley 11 and join once more the pulley 11 facing it, without being engaged in any of the frames 50 , 60 , 70 . The strand 91 then engages in the bore 74 in the frame 70 , in order to exit once more via the bore 75 , pass above the edge of the frame 70 , and extend as far as the bore 54 in the frame 50 . The strand 91 then engages through the bore 54 in the frame 50 , extends on the second face 57 of the frame 50 whilst running along an edge adjacent to the edge 58 , then passes through the bore 51 , and extends on the first face 56 of the frame 50 whilst running along the edge 56 of the frame 50 , then passes through the bore 52 , before engaging through the bore 63 in the frame 60 . The strand 91 then extends between the bore 63 and the bore 62 , exits once more via the bore 62 , and passes above the edge of the frame 60 , in order to be wound around the pulley 11 and join once more the pulley 11 facing it, without being engaged in any of the frames 50 , 60 , 70 . The strand 91 then engages in the bore 72 in the frame 70 , in order to exit once more via the bore 73 , pass above the edge of the frame 70 , and extend as far as the bore 52 in the frame 50 .
[0032] This embodiment makes it possible to obtain a cable actuator, the variations of length and resilience of which have a uniform effect on the operation of the actuator.
[0033] The invention is not limited to the preceding description, but incorporates all variants included in the scope of the invention defined by the claims. In particular, although in this case the anchorage unit is in the form of a frame, the anchorage unit can have any form once it is rendered integral with the nut, whilst being mobile relative to the latter. Any means for coupling the anchorage unit to the nut can be envisaged.
[0034] In addition, although, in the examples illustrated, the anchorage unit is coupled to the nut by coupling means which are connected to the anchorage unit at two points which define a first axis transverse to the axis of rotation of the screw, with the cables being coupled to the anchorage unit at a second transverse axis which is perpendicular to the first transverse axis, the two transverse axes need not be perpendicular to one another, but simply oblique.
[0035] Finally, if the misalignments of the cables are negligible, it is possible to dispense with an intermediate anchorage unit, and couple the cables directly to the nut. | A cable actuator comprising a chassis ( 1 ), a screw ( 2 ) mounted rotatably on the chassis and driven by an electric motor, a nut ( 4 ) engaging with the screw and associated with anti-rotation means such that a rotation of the screw, under the action of the motor, results in an axial movement of the nut, and two substantially parallel cables ( 10 ) coupled to the nut on either side of same. The cables are linked to an anchoring member ( 20; 30; 40 ) that is interposed between the nut and the cables, the anchoring member being secured to the nut while also being movable relative to same. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for treating waste gases containing ClF 3 . More particularly, the present invention relates to a method by which waste gases that result from the step of dry cleaning the inside surfaces of processing apparatus and related jigs in semiconductor device fabrication with ClF 3 can be rendered harmless by removing not only ClF 3 but also acidic gases including SiCl 4 , SiF 4 , Cl 2 and F 2 .
2. Description of the Prior Art
In order to meet the recent demand for reducing the feature size of VLSIs and improving the efficiency of their fabrication, there has been a growing need for auto-cleaning the inside surfaces of CVD and PVD apparatus as well as related jigs in the fabrication of semiconductor devices. In this respect, the effectiveness of ClF 3 has attracted the attention of manufacturers since it is capable of plasmaless cleaning at low concentrations and temperatures. However, ClF 3 has a very high level of toxicity (TLV-TWA=0.1 ppm) and it is strongly desired to establish a method of rendering ClF 3 harmless. Common methods for making ClF 3 harmless include wet systems using a scrubber with aqueous alkaline solutions and dry systems using soda lime or activated alumina.
In the prior art, ClF 3 cannot be completely removed by single use of treating agents such as alkali agents or activated alumina. In addition, chlorine oxides are released by reaction with the treating agents used. Further, acidic gases such as SiCl 4 , SiF 4 , Cl 2 and F 2 that are discharged together with ClF 3 can only be partially removed, or they can only be removed in very small amounts.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a process for treating ClF 3 containing gases by which the content of ClF 3 can be reduced below the TLV-TWA level despite simultaneous emission of acidic gases, and yet which is capable of removing the concomitant acidic gases in an effective manner.
Other objects and advantages of the present invention will be become apparent to those skilled in the art from the following description and disclosure.
DETAILED DESCRIPTION OF THE INVENTION
In its first aspect, the present invention attains its object by bringing a waste gas containing ClF 3 into contact with an iron oxide at ordinary temperatures.
In its second aspect, the present invention attains its object by bringing a waste gas containing ClF 3 into contact first with an iron oxide at ordinary temperatures and then with an alkali agent. In this second approach, a waste gas containing not only ClF 3 but also acidic gases such as SiCl 4 , SiF 4 , Cl 2 and F 2 is treated by the present invention in the following specific way: first, the waste gas is brought into contact with an iron oxide at ordinary temperatures so that ClF 3 in the waste gas is fixed as an iron fluoride or chloride on the surface of the iron oxide; secondly, gaseous fluorides and chlorides that are released as by-products are nearly removed by an alkali agent so that the waste gas becomes harmless.
When a waste gas containing ClF 3 is brought into contact with an iron oxide, ClF 3 is fixed as an iron fluoride or chloride on the surface of the iron oxide. An example of the reaction between ClF 3 and iron oxide is represented as follows:
3ClF.sub.3 +2Fe.sub.2 O.sub.3 →3FeF.sub.3 +FeCl.sub.3 +3O.sub.2.
While ClF 3 is fixed as FeF 3 and FeCl 3 on the surface of iron oxide, gaseous fluorides and chlorides are released as, for example, ClO 2 , FO 2 , HCl, HF, etc. These gaseous components are removed by neutralization through contact with the alkali agent. The other acidic gases in the waste gas can be substantially fixed as the iron fluorides and chlorides by mere contact with the iron oxide.
The iron oxide to be used in the present invention may be any ordinary commercial product as long as it is substantially composed of ferric oxide (Fe 2 O 3 ). Further, this iron oxide may be granular, rod-shaped, tabular or in any other form that is easy to handle and it need not be treated or processed in any special way to have a particularly high purity.
The alkali agent to be used in the present invention is preferably at least one alkaline earth metal compound selected from the group consisting of calcium hydroxide, calcium oxide, magnesium hydroxide or magnesium oxide. The shape of this alkali agent also is not limited in any particular way.
On the condition that an undesirably high pressure loss does not occur in the passage of waste gases, the particles of those treating agents are preferably as small as possible, desirably in the range of about 3-32 mesh, more desirably about 7-16 mesh, in order to ensure a large contact area.
The waste gases need be treated at ordinary temperatures and using elevated temperatures is not economical in view of the need to make the material and construction of the apparatus heat-resistant.
The waste gases are allowed to pass through said treating agents at a linear velocity (LV) of about 10-200 cm/min, preferably about 10-100 cm/min, to attain contact between said waste gases and said treating agents.
In practice, a column may be packed with two stages of treating agents (iron oxide and alkali agent) in specific amounts that depend on the load of a waste gas to be treated; then, the waste gas is supplied into the column either downwardly or upwardly so that it is brought into contact first with the iron oxide and then with the alkali agent.
EXAMPLES
The following examples are provided for the purpose of further illustrating the present invention but are in no way to be taken as limiting.
EXAMPLE 1 AND COMPARATIVE EXAMPLES 1-3
A polyacrylic vessel (40 mm.sup.φ) was packed with four different treating agents to a height of 50 mm and supplied with N 2 diluted ClF 3 (1 v/v %) at a flow rate of 0.3 l/min (LV=about 24 cm/min) at ordinary temperatures. In order to monitor the concentration of ClF 3 at the exit end, the concentration of chlorine oxides was measured with a detection tube (produced by Gastec Corporation). The treatment was continued until the concentration of chlorine oxides exceeded the detection limit (0.1 ppm as TLV) and the throughput of ClF 3 treatment was determined from the cumulative volume of ClF 3 and the amount of each treating agent packed. At the same time, the amounts of gaseous fluoride and chloride compounds that evolved as by-products of the treatment at the exit end of the layer of each treating agent were measured by the combination of absorption by alkali solution and ion-exchange chromatography.
The treating agents used were commercial products in a granular form having particle sizes of 7-16 mesh.
The results are shown in Table 1. When Fe 2 O 3 was used as a treating agent, the throughput was the highest (13 l of ClF 3 per liter of treating agent) but fluorides and chlorides were detected as by-products. Comparative treating agents, Al 2 O 3 , CaO.NaOH and Ca(OH) 2 , achieved much lower throughputs with high yields of by-products.
TABLE 1__________________________________________________________________________ Through- put of Concen- ClF.sub.3 Amount of F Amount of Cl tration (l-ClF.sub.3 / evolution: evolution: of l- total F total ClTreating ClF.sub.3 treating as ClF.sub.3 as ClF.sub.3agent (v/v %) agent) (ppm) (ppm)__________________________________________________________________________Ex. 1 Fe.sub.2 O.sub.3 1 13 0.19-0.32 0.43-0.51 (0.26) (0.47)Comp. Al.sub.2 O.sub.3 1 1.3 2.1-3.2 2.9-4.2Ex. 1 gel (2.6) (3.4)2 CaO.NaOH 1 0.6 4.5-6.3 3.7-7.1 (5.2) (5.9)3 Ca(OH).sub.2 1 0 -- --__________________________________________________________________________ Note: Numerals in parentheses refer to average values.
EXAMPLES 2-5
The ability of Fe 2 O 3 to treat acidic gases was evaluated using an apparatus of the same type as used in Example 1. The Fe 2 O 3 used as the treating agent was also of the same type as in Example 1. Four acidic gases, SiCl 4 , SiF 4 , Cl 2 and F 2 , each (2 v/v %) diluted with N 2 was individually supplied into the apparatus at a flow rate of 0.3 l/min (LV=about 24 cm/min) at ordinary temperatures. The treatment was continued until these gases were detected with a detection tube at the exit end of the apparatus, the detection limit of SiCl 4 , SiF 4 , Cl 2 and F 2 being 5 ppm as HCl, 3 ppm as HF, 1 ppm and 1 ppm, respectively. Their throughputs were determined from the cumulative volumes of the input gases. The results are shown in Table 2. It was verified that the four acidic gases under test could be removed using Fe 2 O 3 .
TABLE 2______________________________________ GasTreating concentration Throughputagent Acidic gas (v/v %) (l/l)______________________________________Example 2 Fe.sub.2 O.sub.3 SiCl.sub.4 2 163 Fe.sub.2 O.sub.3 SiF.sub.4 2 354 Fe.sub.2 O.sub.3 Cl.sub.2 2 35 Fe.sub.2 O.sub.3 F.sub.2 2 45______________________________________
EXAMPLE 6
A polyacrylic vessel (40 mm.sup.φ) was divided into two stages, one of which was packed with Fe 2 O 3 to a height of 200 mm and the other being packed with Ca(OH) 2 to a height of 50 mm. The Fe 2 O 3 and Ca(OH) 2 used were of the same types as used in Example 1 and Comparative Example 3, respectively. A N 2 diluted gaseous mixture of ClF 3 and SiF 4 was supplied into the vessel at a flow rate of 0.3 l/min (LV=about 24 cm/min) at ordinary temperatures so that it would first pass through the layer of Fe 2 O 3 , then through the layer of Ca(OH) 2 . The concentrations of ClF 3 and SiF 4 were each 1 v/v % at the entrance to the vessel.
The amounts of discharged chlorine oxide, fluorides and chlorides were measured at the exit end of the Ca(OH) 2 layer. The treatment was continued for 830 minutes and it was verified that those components had been removed to levels below their detection limit (0.1 ppm as ClF 3 ).
According to the present invention, not only ClF 3 but also concomitant acidic gases can be effectively removed. Further, the treating agents used in the method of the present invention have such a high throughput that they need not be replaced for a prolonged period of time. | Waste gases containing ClF 3 are treated by bringing them into contact with iron oxide substantially composed of a ferric oxide (Fe 2 O 3 ) at a linear velocity of about 10-200 cm/min at ordinary temperatures, or further into contact with an alkali agent at the same linear velocity and temperatures as the above, whereby the content of ClF 3 can be reduced below the permissible level despite simultaneous emission of acidic gases, and yet which is capable of removing the concomitant acidic gases in an effective manner. | 1 |
RELATED APPLICATIONS
[0001] The following applications of the common assignee, which are hereby incorporated by reference, may contain some common disclosure and may relate to the present invention:
[0002] U.S. patent application Ser. No. ______, entitled “RANDOM NUMBER GENERATORS IMPLEMENTED WITH CELLULAR AUTOMATA” (Attorney Docket No. 10017475-1); and
[0003] U.S. patent application Ser. No. ______, entitled “SOFTWARE IMPLEMENTATION OF CELLULAR AUTOMATA BASED RANDOM NUMBER GENERATORS” (Attorney Docket No. 10019023-1).
FIELD OF THE INVENTION
[0004] This invention relates generally to random number generation. More specifically, this invention relates to systems and methods to generate cellular automata based random number generators (CA-based RNG).
BACKGROUND OF THE INVENTION
[0005] Since the inception of computers, random numbers have played important roles in areas such as Monte Carlo simulations, probabilistic computing methods (simulated annealing, genetic algorithms, neural networks, and the like), computer-based gaming, and very large scale integration (VLSI) chip-testing. The bulk of the investigation into random (more properly, pseudo-random) number generation methods has been centered around arithmetic algorithms. This is because the prevalent computing medium has been the general purpose, arithmetic computer. Digital hardware designers have long relied on feedback shift registers to generate random numbers.
[0006] With the advent of VLSI design, built-in self-tests have become advantageous. In this design, the bulk of the chip testing system is incorporated on the chip itself. Linear feedback shift registers were used initially to implement the random number generation portion of the built-in self-test.
[0007] In 1986, Wolfram (S. Wolfram, “Random sequence generation by cellular automata,” Advances in Applied Mathematics , vol. 7, pp. 123-169, June 1986) described a random sequence generation by a simple one-dimensional (1-d) cellular automata with a neighborhood size of three. The work focused on the properties of a particular CA-based RNG dubbed “CA30,” so named due to the decimal value of its truth table. Statistical tests indicated that the CA30 was a superior random number generator to the ones based on linear feedback shift registers. Wolfram suggested that efficient hardware implementation of the CA30 should be possible.
[0008] Hortensius et al. (P. D. Hortensius, R. D. McLeod, and H. C. Card, “Parallel number generation for VLSI systems using cellular automata,” IEEE Transactions on Computers, vol. 38, no. 10, pp. 1466-1473, October 1989) described the use of CA30 as a random number generator in an Ising computer. They also described using combinations of CAs (CA90 and CA150), which generated even better random numbers than the CA30. They further indicated that time and site spacing may improve statistical quality of random numbers generated by the CA. Time spacing is where the RNG is advanced more than one step between random number samples and site spacing is where not every bit value generated is used.
[0009] Cellular automata (CA) may be thought of as a dynamic system discrete in both time and space. CA may be implemented as an array of cells with homogeneous functionality constrained to a regular lattice of some dimension. For example, in one-dimension, the lattice could be a string (open-ended) or a ring (close-ended), or in two-dimensions, the lattice could be a plane (open-ended) or a toroid (close-ended). Open-ended CAs have boundaries that are fixed and close-ended CAs have boundaries that are periodic.
[0010] A function of a CA cell may be represented as a truth table. FIG. 1A shows an exemplary truth table for a four-input CA cell. FIG. 1B shows an exemplary implementation of a cell of the CA. As shown, the cell i implicitly includes a one-bit register. In this instance, there are 16 possible conditions to which a cell may respond (the neighborhood size N is 4 corresponding to the number of inputs). The number of unique responses is 2 2 N or 65,536 (see Table 1 below). In other words, there can be 65,536 unique four-input machines for a given interconnection topology.
[0011] Referring back to FIG. 1A, a notation is provided to identify the CA implementing the above function. In essence, the output of the truth table is used as the identification in conjunction with the interconnection notation. As shown, the output of the truth table is converted to a number (from binary to base 16 to decimal). The CA represented by the truth table in FIG. 1A is denoted to be CA06990.
[0012] As indicated before, a CA may be made of multiple cells, and the inputs of one cell may connected to the output of other cells. There may even be a feedback contact meaning that one of the inputs of the cell is connected the output of the cell itself. Thus, to uniquely identify a CA, the interconnection topology information should also be provided in addition to it's truth table representation. FIG. 1C illustrates an exemplary notation, a relative displacement notation, which indicates the interconnection topology information of cell i, i.e., how far away the connecting cells are relative to a given four-input cell i.
[0013] As an example, FIG. 1D illustrates a 64-cell one-dimensional ring automata network with a displacement of {−1, 0, 1, 2} from the perspective of cell 0. In this instance, each cell i is assumed to have the same displacement value, i.e., all cells have identical functions. In a one-dimensional ring CA network, each cell i has two adjacent neighbors, one on either side. Because the CA network is periodic, cell 63 is adjacent to the cell 0, and thus the displacement of i−1 from cell 0 lands on cell 63.
[0014] In a one-dimensional CA network, a relative displacement value {-1, 0, 1, 2} indicates that d 8 input of cell i is connected to the output of the cell i−1 (one cell to the left), the d 4 input is connected to the output of the cell i itself, the d 2 input to cell i+1, and the d 1 input to cell i+2. More specifically, from the perspective of cell 0, the inputs d 8 , d 4 , d 2 , and d 1 are connected to the outputs of cell 63, itself, cell 1, and cell 2, respectively.
[0015] Each cell in the CA network has a state that is updated as a function of its neighbor connections at each time step. In other words, the state of a CA at time t depends on the states of the connected neighbors at time t−1. For a binary CA cell with a neighborhood size of N, there are 2 2 N possible functions. Table 1 illustrates the numbers involved. As Table 1 shows, the universe of possible functions increases extremely rapidly as the number of neighbors N grows.
TABLE 1 Neighborhood size N # of Possible Functions 1 4 2 16 3 256 4 65,536 5 4,294,967,296 6 1.84 × 10 19 7 3.4 × 10 38
[0016] It is theoretically possible to exhaustively search for viable CA-based RNG. However, in reality, the exhaustive search may be conducted for a small neighborhood size due to the tremendous growth of the search space (truth tables). With modem state of the art computing, N=4 may be the practical limit for exhaustive searches.
SUMMARY OF THE INVENTION
[0017] In a first aspect of the present invention, an embodiment of a method to reduce a search space for determining viable cellular automata based random number generators (CA-based RNGs) may include counting number of 1s and 0s of outputs of a truth table for a candidate CA-based RNG and counting number of 1s and 0s of inputs of the truth table for the candidate CA-based RNG. The method may also include accepting or rejecting the candidate CA-based RNG based on results of the counting steps.
[0018] In a second aspect of the present invention, a system to reduce a search space for determining viable cellular automata based random number generator (CA-based RNGs) may include a truth-table-counting-module counting number of 1s and 0s of outputs of a truth table for a candidate CA-based RNG. The truth-table-counting module may also count number of 1s and 0s of inputs of the truth table for the candidate CA-based RNG. The system may also include a prescreening-module accepting or rejecting the candidate CA-based RNG based on an output or outputs of the truth-table-counting module.
[0019] In a third aspect of the present invention, computer readable medium may have embedded a software comprising a set of instructions for performing a method to reduce a search space for determining viable cellular automata based random number generator (CA-based RNGs). The embedded method may include counting number of 1s and 0s of outputs of a truth table for a candidate CA-based RNG and counting number of 1s and 0s of inputs of the truth table for the candidate CA-based RNG. The method may also include accepting or rejecting the candidate CA-based RNG based on results of the counting steps.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Features of the present invention will become apparent to those skilled in the art from the following description with reference to the drawings, in which:
[0021] [0021]FIG. 1A illustrates an exemplary truth table for a four-input cellular automata cell and the naming notation for the cellular automata;
[0022] [0022]FIG. 1B illustrates an exemplary implementation of a cell of a cellular automata;
[0023] [0023]FIG. 1C illustrates an exemplary notation, a relative displacement notation, which provides a connection information of a CA cell;
[0024] [0024]FIG. 1D illustrates an exemplary cellular automata showing the relationship between the relative displacement notation and the interconnection topology;
[0025] [0025]FIG. 2 illustrates an exemplary method to prescreen a candidate CA-based RNG; and
[0026] [0026]FIG. 3 illustrates a block diagram of an exemplary system to prescreen a candidate CA-based RNG.
DETAILED DESCRIPTION
[0027] For simplicity and illustrative purposes, the principles of the present invention are described by referring mainly to exemplary embodiments thereof. However, one of ordinary skill in the art would readily recognize that the same principles are equally applicable to many situations in which random numbers generators are determined.
[0028] High quality random numbers generators (RNGs) that pass stringent statistical tests may be implemented with cellular automata (CA). The basis of each cell is a logic function, which can be described by a truth table such as shown in FIG. 1A. It is also discussed above that the number of binary logic truth tables with N-inputs is 2 2 N . As shown in Table 1, for N=4, the number of truth tables is 65,536. When N=5, the number of truth tables for a particular topology grows to over 4 billion.
[0029] To put this into perspective, assume that viable CA-based RNGs with N=5 are being searched. The simplest instance is where the CA-based RNG has identical-function cells, i.e., the truth table is identical for all cells for the CA. In this instance, for a given topology, there are over 4 billion candidate RNGs, and each candidate RNG must be tested and evaluated. Depending of the length of the random number desired, the testing time will correspondingly increase. For example, desired length of the random may be 32 bits, 64 bits, etc. This process must be repeated for all possible topologies. As the numbers show, when searching for new random number generator implementations, reducing the search space is greatly desirable.
[0030] After performing exhaustive searches on neighborhood size of 4 CA-based RNGs, the inventors of the present invention have discovered that the CA-based RNGs that pass the battery of stringent random number tests (such as the DIEHARD suite of tests) all have common characteristics regarding their functions as represented by their truth tables.
[0031] First, the number of is in the output column was typically equal to the number of 0s, i.e., each count was 8. Second, the number of 1s and 0s in the input contributing to output a 0 were typically equal as well. Similarly, the number of 1s and 0s in the input contributing to output a 1 were typically equal. This is clarified by the example below.
[0032] Assume that a truth table is as follows (CA21530):
d 8 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 d 4 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 d 2 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 d 1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 F 0 1 0 1 0 1 0 1 1 0 1 0 1 0 1 0
[0033] For the CA21530, there are eight 1s and eight 0s in the output. Also, for all combination of inputs (d 8 , d 4 , d 2 , d 1 ) contributing to output a 0, there are sixteen Is and sixteen 0s in the inputs. In a similar manner, it is also seen that there are sixteen 1s and sixteen 0s in the input contributing to output a 1. This indicates that the CA21530 is good candidate to pass the battery of random number tests, and thus passes the prescreening process. However, majority of the truth tables do not exhibit these characteristics and thus would not pass the prescreening process. This reduces the search space considerably.
[0034] [0034]FIG. 2 illustrates an exemplary method 200 to reduce a search space to determine viable CA-based RNGs. More specifically the method 200 prescreens a candidate CA-based RNG. In step 210 , 1s and 0s of the truth table output of the candidate CA-based RNG may be counted. In step 220 , if the difference in the output counts is less than or equal to a predetermined output difference threshold, then the method 200 may proceed to step 230 . Otherwise, the method 200 may proceed to step 280 indicating that the particular candidate RNG has failed the prescreen process.
[0035] The predetermined output difference threshold may be zero indicating that there must be equal number of 1s and 0s. However, it is within the scope of the invention that strict adherence to equal number of 1s and 0s may not be necessary, especially as the neighborhood size N grows larger. Thus, if N is 5 or greater, then perhaps a count difference of 2 or even 4 may be tolerated. Note this predetermined output difference threshold is a parameter that may be set.
[0036] In step 230 , the method 200 counts the 1s and 0s of the inputs in the truth table that generate 1s as outputs. In step 240 , if the difference in the input count is less than or equal to a predetermined 1s input difference threshold, then the method 200 proceeds to step 250 . Else, the method 200 proceeds to step 280 . Again, the predetermined 1s difference threshold may be set to be greater than 0.
[0037] In step 250 , the method 200 counts the 1s and 0s of the inputs in the truth table that generate 0s as outputs. In step 260 , if the difference in the input count is less than or equal to a predetermined 0s input difference threshold, then the method 200 proceeds to step 270 indicating that the candidate RNG has passed the prescreening process. Else, the method 200 proceeds to step 280 . As before, the predetermined 0s difference threshold may be set to be greater than 0.
[0038] Note that the steps of the method 200 may be modified and achieve a similar result. The steps may be modified, deleted or other steps may be added and still be within the scope of the invention.
[0039] The following example demonstrates how the screening process described above may reduce the search space. For a neighborhood size of 5 (each truth table has 32 entries), exhaustive search would require over 4 billion candidate RNGs to be evaluated for each given topology. However, if a strict equality of output counts is enforced, the number of candidate RNGs having sixteen is and sixteen 1s in the output is reduced to 601,080,390. In addition, if a strict equality of input counts is enforced, then the number of candidate RNGs is further reduced to 36,497,130. Thus from the original search space of 4,294,967,296, the search space is reduced by a factor of over 100—a reduction of over two orders of magnitude.
[0040] The method 200 may exist in a variety of forms both active and inactive. For example, they may exist as software program(s) comprised of program instructions in source code, object code, executable code or other formats. Any of the above may be embodied on a computer readable medium, which include storage devices and signals, in compressed or uncompressed form. Exemplary computer readable storage devices include conventional computer system RAM (random access memory), ROM (read only memory), EPROM (erasable, programmable ROM), EEPROM (electrically erasable, programmable ROM), flash memory, and magnetic or optical disks or tapes. Exemplary computer readable signals, whether modulated using a carrier or not, are signals that a computer system hosting or running the computer program may be configured to access, including signals downloaded through the Internet or other networks. Concrete examples of the foregoing include distribution of the program(s) on a CD ROM or via Internet download. In a sense, the Internet itself, as an abstract entity, is a computer readable medium. The same is true of computer networks in general.
[0041] [0041]FIG. 4 illustrates a block diagram of an exemplary system 400 to prescreen a candidate CA-based RNG. As shown, the system may include a truth-table-counting-module 410 counting the outputs and the inputs of the truth table of the candidate CA-based RNG. The output counting may be performed by an output-counting-module 412 and the input counting may be performed by an input-counting-module 414 . The system 400 may also include a prescreening-module 420 which accepts or rejects the candidate CA-based RNG based on the results outputted by the truth-table-counting-module 410 .
[0042] While the invention has been described with reference to the exemplary embodiments thereof, those skilled in the art will be able to make various modifications to the described embodiments of the invention without departing from the true spirit and scope of the invention.
[0043] The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. In particular, although the method of the present invention has been described by examples, the steps of the method may be performed in a different order than illustrated or simultaneously. Those skilled in the art will recognize that these and other variations are possible within the spirit and scope of the invention as defined in the following claims and their equivalents. | A system and a method to reduce a search space to determine viable cellular automata based random number generators (CA-based RNGs) are presented. A CA-based RNG is where an output of each cell of the CA at time t is dependent on inputs from any cells of the CA (including perhaps itself) at time t−1. The connections (or inputs) are selected to produce high entropy such that the RNG passes a standard suite of random number of tests, such as the DIEHARD suite. As the number of inputs grow (corresponding to the neighborhood size), the number of truth tables grows dramatically. By reducing the search space of viable CA-based RNGs, high quality random number generators with higher neighborhood sizes may be found. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a closed-type electromagnetic compressor, and more particularly relates to improved collimation and lubrication mechanisms in a closed-type (i.e., sealed) compressor preferably used for cooling systems in which both driving and pumping parts reciprocate in the axial direction of the compressor for compressive pumping action.
A closed-type compressor provided with an electromagnetic drive is already known in the art. In the construction of the compressor of this type, at least one stator core is connected via a half-wave rectifier circuit to a given AC source and a magnetic armature is allowed to reciprocate in the axial direction of the compressor across, i.e., substantially at a right angle to the line of magnetic induction generated by the stator core. The armature is integrally coupled with a piston which carries out the pumping action by its reciprocation in the piston chamber. When a pair of axially spaced stator cores are provided, electromagnetic attractions generated by alternate excitation of the two stator cores and acting on the armature cause reciprocation of the piston. Whereas, when only one set of stator core is used, movement of the piston in one direction is caused by the magnetic attraction acting on the armature and movement of the piston in the other direction is caused by a separate urging mechanism acting mechanically on the piston. One typical example of such an urging mechanism is given in the form of a return spring.
However, it is well known that conventional compressors of the above-described type have never been welcomed in the actual field of industry. Major causes for this poor acceptance of the conventional machines in the actual field of industry are thought to be as follows.
In the case of compressors of the rotary drive type, one end of the crank shaft of the rotary electric motor is immersed within lubrication oil so that the oil is supplied to the shaft bearing parts as the shaft rotates. In another example, a screw pump type oil supply system is used for lubrication.
In contrast to this, the compressor of the above-described reciprocal drive type contains no rotary shaft in its construction and, therefore, the above-mentioned lubrication system employed in the rotary drive type compressors cannot be utilized for lubrication of the reciprocal drive type compressors. This requires provision of a separate oil supply pump in the construction of the reciprocal drive type compressors entailing complicated construction, troublesome maintenance and escalated manufacturing costs.
Further, in the pumping mechanism of the reciprocal drive type compressors, reciprocation of the piston with the armature plays the most important decisive role. So, when the collimations of the armature with the stator core and of the piston with the bearing part are not in order, biased attraction on the armature and/or biased load on the piston has an undesirable influence on the life of the piston and its related parts. In order to obviate such problems, precise collimation must be established between the above-mentioned elements, which in general calls for complicated, time-consuming and highly skilled work in assembling the compressors.
BRIEF DESCRIPTION OF THE INVENTION
It is a principal object of the present invention to provide a closed-type electromagnetic compressor with a reciprocal drive provided with a novel lubrication system of a simple construction.
It is another object of the present invention to provide a closed-type electromagnetic compressor in which reliable and stable collimation of the piston with its related parts can be easily established.
In order to attain the above-described objects, the compressor in accordance with the present invention is provided, in addition to elements common to reciprocal drive type compressors, with means for establishing such a collimation and provided in the coupling plane of the driving part with the pumping part and means for lubricating the sliding plane of the piston within the bearing part of the machine which utilizes the gas flow returning into the compressor from the given gas circulation system.
Although the following explanation is limited to an embodiment in which magnetic attraction is used in combination with spring repulsion for effecting the piston reciprocation, it will be well understood that the present invention is applicable to reciprocal drive type compressors in which alternately generated magnetic attractions are used for effecting the piston reciprocation or in which magnetic attraction is used in combination with mechanical urging devices for the reciprocating piston other than the spring repulsion type.
It should be further noted that the present invention is applicable to any closed-type compressor with an electromagnetic drive in which a magnetic armature reciprocates across the line of magnetic induction, although the following description is limited to the one in which the armature reciprocates across, i.e., substantially at a right angle, the line of magnetic induction.
Further features and advantages of the present invention will be made clearer from the following description, reference being made to the accompanying drawings.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 is a front plan view, partly in section, of embodiment of the closed-type electromagnetic compressor to which the present invention is applied,
FIG. 2 is a section taken along the line 2--2 in FIG. 1,
FIG. 3 is a section taken along the line 3--3 in FIG. 1,
FIG. 4 is a section taken along the line 4--4 in FIG. 2,
FIG. 5 is a perspective plan view of the piston and its related major parts,
FIG. 6 is a perspective plan view of the stator core and
FIG. 7 is an electric connection diagram relating to the stator core shown in FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
In the following description, the terminal side of the compressor along the line of piston reciprocation on which an electromagnetic driving part is located will be referred to with terms "front" and "forward" whereas the terminal side on which a pumping part is located will be referred to with terms "rear" and "rearward." Further, when reference is made to vertical positional relationship, it is assumed that the compressor is placed in a normal posture with the direction of the piston reciprocation being in a horizontal plane.
As seen in FIGS. 1 and 2, a compressor assembly 14 of the compressor in accordance with the present invention is enclosed within a closed casing 12 made up of upper and lower halves 12a and 12b fixedly coupled to each other at their open ends.
The compressor assembly 14 is provided at its bottom with a pair of legs 16 and 18 and, in correspondence with them, a pair of spring seats 20 and 22 are formed on the inner bottom surface of the lower half 12b. Compression springs 24 and 26 are inserted over the legs 16 and 18 and the seats 20 and 24, respectively, so that the compressor assembly 14 can be elastically suspended within the closed casing 12. This suspension gives the compressor assembly 14 some extent of freedom to reciprocate in the axial direction of the compressor during the piston operation.
Separately from this, a stopper piece 28 is fixed to the inner ceiling of the upper half 12a in order to restrain excessive, unnecessary movement of the compressor assembly 14 within the closed casing during transportation thereof.
The compressor assembly 14 is comprised of the pumping part 30 on the rear side and the electromagnetic driving part 80 on the front side both parts lying along the axis of the compressor, which coincides with the direction of the piston reciprocation.
Referring to FIGS. 3 and 4, the pumping part 30 includes, as major elements, a main body 36 having a cylindrical part 34 and a cylinder head 44 fixed to the rear end of the cylindrical part 34 by screws 38. The cylindrical part 34 defines a piston chamber in which a later described piston 72 reciprocates in order to compress the cooling gas. The cylinder head 44 is internally provided with a suction valve 40 for introducing the cooling gas into the piston chamber and a discharge valve 42 for delivering the cooling gas out of the piston chamber.
A suction chamber 46 and a discharge chamber 58 is formed in the main body 36 on opposite lateral sides of the piston chamber.
As can best be seen in FIG. 4, the upper opening of the suction chamber 46 is covered by a closure 50 via a set bolt 52 screwed into the bottom of the chamber 46 and a suction pipe 48 extends through the closure 50 while opening in the chamber 46 in order to introduce the cooling gas prevailing in the closed casing 12 into the suction chamber 46. A suction port 56 is formed in the cylinder head 44 in communication with the piston chamber via the suction valve 40 and with the above-described suction chamber 46 via a suction hole 54 formed through the main body 36. Thus, following the piston action, the cooling gas introduced into the suction chamber 46 flows into the piston chamber through the suction hole 54, the suction port 56 and the suction valve 40 in the open state.
The upper opening of the discharge chamber 58 is covered by a closure 62 via a set bolt 64 screwed into the bottom of the chamber 58 and a discharge pipe 60 extends through the closure 62 while opening in the chamber 58 in order to deliver the compressed cooling gas out of the discharge chamber 58. A discharge port 66 is formed in the cylinder head 44 on the opposite side of the suction port 56 with respect to the compressor axis in communication with the piston chamber via the discharge valve 42 and with the above-described discharge chamber 58 via a discharge hole 68 formed through the main body 36. Thus, following the piston action, the cooling gas compressed in the piston chamber flows into the discharge chamber 58 through the discharge valve 42, the discharge port 66 and the discharge hole 68.
In connection with the above-described closure 62 for the discharge chamber 58, it is necessary that the upper surface of the closure 62 should be recessed below the surrounding surfaces of the main body 36 so that the recess should function as an oil reservoir 122 of the lubrication mechanism 110 which will be later explained in more detail.
As shown in FIG. 5, the main body 36 is provided on its front end with two pairs of projections 36a, 36a and 36b, 36b each projection having a seat 70 for receiving the electromagnetic driving part 80. In order to enable easy and reliable collimation of the electromagnetic driving part 80 with the pumping part 30, the pair of seats 70 arranged on a common diagonal are made symmetric to each other in their shapes and positions with respect to the center axis c of the cylindrical part 34 of the main body 36, which is shown with a chain-and-dot line in FIG. 5.
A stator core 82 forming the main part of the electromagnetic driving part 80 is comprised of a number of magnetic steel plates superimposed upon each other as shown in FIG. 6. Each of the plates has a confronting double E profile and, in the superimposed disposition, the confronting inner ends of the middle arms of the plates provides a pair of magnetic poles 84 spatially confronting to each other. The magnetic poles 84 define a column shaped magnetic field space 88 there between which space is so dimensioned as to allow free reciprocation of the later described armature 86 therethough during the pumping action. To this end, the end surfaces of the magnetic poles 84 are curved so as to conform to the circular curvature of the peripheral surface of the armature 86.
As shown in FIG. 7 the magnetic poles 84 are accompanied with stator windings 90 which are connected to a given AC source 92 via a rectifier 94 by connections 91.
On the side to face front end of the main body 36, the stator core 82 is accompanied with a steel plate 98 of a rather thick construction and fitting seats 96 are formed on the four corners of the steel plate 98. The pair of seats 96 on a common diagonal are made symmetric to each other in their shapes and positions with respect to the center axis of the magnetic field space 88 of the stator core 82. It is also necessary that the shapes and positions of the four fitting seats 96 should be so designed that they come into snug engagement with the corresponding fitting seats 70 formed on the projections of main body 36 when the stator core 82 is coupled to the main body 36. It is also possible to form the fitting seats 96 directly on the rear end surface of the superimposed magnetic plates of the stator core 82 with omission of the additional steel plate 98. However, use of the steel plate 98 assures easier formation of the fitting seats by machining.
The stator core 82 is fixedly coupled to the main body 36 by set screws 100 screwed down into threaded holes 35 formed in the front surfaces of the projections 36a and 36b. (see FIGS. 3 and 5)
The above-described armature 86 is integrally joined to the front end of the piston 72 via a set screw 74 and, in the coupled disposition of the stator core 82 with the main body 36, the body of the piston 72 is axially slidably received in the piston chamber defined by the cylindrical part 34 with the stator core 82 being exposed forwards out of the main body 36 as shown in FIG. 3.
A dome-shaped supporter cover 108 is fixed to the front end of the stator core 82 by the set screws 100, and this cover 108 is provided on its inner central portion with a pivot suspension 106 which rotatably carries a spring seat 104. A compression coil spring 102 is inserted between the seat 104 and the rear end of the stator core 82.
Referring now again to FIGS. 3 and 4, the lubrication mechanism 110 utilizes a cooling gas flow returning from a cooling gas circulation system (not shown) into the closed casing 12. This lubrication mechanism 110 includes a return tube 112 extending inwardly through the lower half 12b of the closed casing 12 and connected to a vertical tube 118. This vertical tube 118 has a lower opening 116 at a position far below the oil level 114 and close to the interior bottom of the lower half 12b. The vertical tube 118 has an upper opening 120 which is positioned above the oil reservoir 122 formed by the recessed closure 62 of the discharge chamber 58.
As shown in FIGS. 4 and 5 a horizontal oil guide 124 is formed in the upper surface of the main body 36 and, in communication with this horizontal oil guide 124, a vertical oil guide 125 is formed in the front end of the main body 36. Thus, in the case of the illustrated embodiment, the oil overflowing from the oil reservoir 122 is introduced to the sliding plane of the piston 72 with the inner surface of the cylindrical part 34 via the horizontal oil guide 124, the vertical oil guide 125, the outer periphery of the cylindrical part 34 and the front end face 126 of the cylindrical part 34.
As an alternative for this lubrication system, an oil conduit may be formed in the main body 36 in such an arrangement that the conduit opens on one hand upwardly in the upper surface of the main body 36 and on the other hand downwardly in one terminal of the cylindrical part 34. In this case, however, it is required that such a conduit should be formed at a position in the main body 36 as remote from the piston chamber as possible so that smooth downward flow of the oil should not be hindered by pressure of the gas leaking from the chamber.
As shown in FIG. 5, the piston 72 is provided with a pair of annular grooves 72a and 72b spaced from each other along the length of the piston 72. The front side groove 72a extends beyond the cylindrical part 34 during the forward movement of the piston 72 and receives the oil flowing down from the overhead oil reservoir 122. Upon the rearward movement of the piston 72, the oil so accomodated in the front side groove 72a is brought into the interior of the cylindrical part 34 for lubrication of the sliding plane. The rear side groove 72b functions as an oil reservoir in order to effectively hinder leakage of the cooling gas from the piston chamber.
The compressor in accordance with the present invention and having the above-described construction operates in the following fashion.
As the stator core 82 is excited by the AC source, an electromagnetic attraction is developed between the stator core 82 and the armature 86 and the piston 72 with the armature 86 moves forwards in the piston chamber while overcoming the repulsion by the spring 102. This forward movement of the piston 72 causes lowering of the gas pressure in the piston chamber, the suction valve 40 opens and the cooling gas in the closed casing 12 in introduced into the piston chamber via the suction pipe 48, the suction chamber 46, the suction hole 54, the suction port 56 and the suction valve 40 now in the open state. The discharge valve 42 remains closed during this procedure as the gas pressure in the discharge port 66 prevails over that in the piston chamber.
As the exciting of the stator core 82 is cancelled, the electromagnetic attraction disappears and the piston 72 is placed under the influence of the repulsion force exerted by the spring 102. That is, the spring 102 forces the piston 72 to move rearwards in the piston chamber and this rearward movement of the piston 72 causes escalation of the gas pressure in the piston chamber. Thus the gas pressure in the piston chamber begins to prevail over that in the suction port 56 and the suction valve 40 closes. Concurrently therewith the discharge valve 42 is forced to open and the compressed gas in the piston chamber is supplied to the cooling system via the discharge valve 42 which is now in the open state, the open discharge port 66, the discharge hole 68, the discharge chamber 58 and the discharge pipe 60. After circulation through the cooling system, the cooling gas returns into the interior of the closed casing 12 via the return tube 112.
Lubrication of the piston mechanism is carried out during this returning process of the cooling gas into the interior of the closed casing 12. As the lower opening 116 of the vertical tube 118 is positioned far below the oil level 114 and the upper opening 120 far above the oil level 114, there exists a pressure difference between the two openings 116 and 120 and, due to this pressure difference, most of the gas flowing out of the return tube 112 tends to flow towards the upper opening 120 and is discharged therefrom into the interior of the closed casing 12. This prevailing gas flow towards the upper opening 120 concurrently generates suction at the lower opening 116 of the vertical tube and the oil so sucked into the vertical tube is mixed with the the return gas to assume a misty state. Keeping this misty state, fine oil particles move towards the upper opening 120 being entrained on the gas flow through the vertical tube 118 and, upon arrival at the upper opening 120, are separated from the gas flow due to the difference in the specific gravity and drop into the oil reservoir 122 formed by the upper closure 62 of the discharge chamber 58. In the case of the illustrated embodiment, the oil so received in the oil reservoir 122 gradually flows towards the sliding plane between the piston 72 and the cylindrical part 34 of the main body 36 via the oil guides 124 and 125 and the front end face 126 of the cylindrical part 34 as the piston 72 reciprocates.
As is clear from the foregoing explanation, the following advantages can be obtained through employment of the present invention.
(a) As a perfect collimation is established between the cylindrical part 34 and the stator core 82 due to the symmetric arrangements of the seats 70 and of the fitting seats 96, the piston 72 and the armature 86 perform stable reciprocation while keeping precise collimation with the stator core 82. As a result, the aramture 86 is quite free of any biased load which otherwise applied thereto by the magnetic fluxes running at right angle to the moving direction of the armature 86. This assures effective elimination of harmful influence upon the life of the piston and its related parts by the biased electromagnetic load.
(b) Once the seats 70 of the main body 36 and the seats 96 of the stator core 82 are set in the symmetric arrangements no special troublesome effort is needed for establishment of the collimation between the main body 36 and the stator core 82. This remarkably simplifies the work in assemblage of the compressor.
(c) As the pressure difference between the two openings 116 and 120 of the vertical tube 118 is excellently utilized, lubrication of the piston and its related parts is as effective as in the case of the conventional rotary lubrication system via the crank shaft of the rotary motor. This assures a long useful operating life of the closed type cooling compressor.
(d) The oil dropping from the upper opening 120 of the vertical tube 118 is once received in the oil reservoir 122 formed atop the main body 36 and supplied therefrom to the sliding plane for the piston lubrication. So, even when the supply of the oil from the vertical tube is intermittent, the oil can be uniformly supplied to the sliding plane as the oil is once stored in the reservoir and overflows out of same when the amount being dropped exceeds the reservoir capacity.
(e) The oil reservoir 122 is positioned just above the discharge chamber 58. As the temperature of the compressed gas fed into the discharge chamber 58 from the piston chamber is very high, the oil stored in the oil reservoir 122 is heated so that the return gas mixing in the stored oil is driven off the stored oil. In other words, a complete separation of the gas from the lubrication oil is carried out at the oil reservoir and, on one hand, the gas so separated is taken into the compression system via the suction pipe 48. Thus, unfavourable introduction of the lubrication oil into the compression and gas circulation systems can be effectively prevented. On the other hand, the oil to be supplied to the lubrication system contains no cooling gas and, thus, the oil contained in the interior of the closed casing 12 contains substantially no cooling gas. Otherwise, the gas contained in the oil may develop numerous bubbles over the oil level as the compressor goes on its operation and the bubbles so developed may fill the interior of the closed casing 12. This clearly causes easy introduction of the lubrication oil into the compression and gas circulation systems.
(f) As the compressor in accordance with the present invention is very compact in its construction, it can advantageously be used for, for example, refrigerators with reduced space necessary for installation thereof.
(g) When compared with compressors of the conventional type with the rotary type cooling system, the compressor in accordance with the present invention provided for a reduced number of the mechanical parts. This fairly leads to lowered manufacturing costs and simplified mechanical maintenance. | In a closed-type compressor with an electromagnetic reciprocating drive, reliable and stable collimation of the electromagnetic driving part with the compressive pumping part is easily established by a snug engagement of fitting seats provided in the coupling plane of the two parts and lubrication of the piston and its related part is effected by a built-in type lubrication mechanism utilizing the flow of the gas returning from the given circulation system with simplified construction as well as in the case of compressors with rotary drive, the compressor being preferably used for cooling systems. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Priority of U.S. provisional patent application Ser. No. 61/050,067, filed 2 May 2008, is hereby claimed, and such application is incorporated herein be reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable.
BACKGROUND
The present invention relates to torquing systems. More particularly, in one embodiment the present invention relates to an improved torque wrench system having multiple torque stations providing for the makeup and removal of a plurality of threaded bolts or nuts. In one embodiment the improved torquing system includes both high torque and low torque phases of the makeup or removal process. In one embodiment both high speed and low speed phases are provided.
In the makeup or break down of large structures, such as, for example rig risers, the sections of the riser are flanged together with bolts threadably engaging the flanges on the end of each section, and made up very tightly to complete the structure. There are numerous other types of structures which use this same system of makeup, i.e., very large bolts through flanges connecting sections of structures.
Flanged riser joints use specially designed bolts that must be torqued to a precise preload. Typically, flanged riser connectors in the offshore drilling industry use six (6) bolt flanges with each bolt straddling an auxiliary line position. During the operation of running the blow out preventer or “BOP” (e.g., initially installing the BOP and riser), an upper flange of a riser joint in the riser string can be landed and supported on the riser spider (e.g., with the spider dogs in an extended state). A new riser joint can stabbed or placed on top of the supported riser joint and the plurality of riser bolts can be turned down and torqued thereby making up the connection. This process can be repeated as many times as needed until the riser string reaches the sea floor and can be attached to the wellhead.
In a typical rig riser structure the flanged sections of the risers include six (6) holes radially spaced apart in about sixty (60) degree increments (around the 360 degree bolt circle of the riser section flanges). The riser string typically extends from the drilling rig above the surface of the water to the wellhead located at sea floor. In deepwater installations the depth of water typically exceeds 5,000 feet. Riser sections are typically provided in 75 foot lengths, yielding a minimum of 67 riser sections or joints and 67 multiplied by 6 (or 402) bolts which must be properly tightened or made up (when installing the riser) or loosened or broken out (when removing the riser).
Presently, when installing or removing riser sections or joints, torque wrenches are manually positioned and operated to individually tighten or loosen each of the six bolts for each riser section or joint. In an effort to speed up the process two torque wrenches operated by two operators can be used addressing two bolts at the same time. However, each operator must individually position and operate his torque wrench on the head of each bolt when tightening or loosening. The operator continues around the flange until all six bolts have been torqued. Additionally, after completing each bolt, the operator must manually remove the torque wrench from the made up bolt and position the torque wrench on the next bolt. After all bolts are torqued down, the spider dogs are retracted and the riser string (e.g., plurality of riser joints and BOP) is lowered to allow the placement and make-up of the connection to the next riser joint section.
This manual process is time consuming and slows down both the initial installation along with the removal of the riser. Additionally, the operators of these torque wrenches can become tired slowing down the process, making mistakes, damaging equipment, and/or causing injury. Due to increasing rig day rates and improved HSE requirements, it is desirable to create a tool that can preload each riser flange connection quicker and without human presence at the well center. This would improve rig operational efficiency as well as safety performance. In a typical yearly operation of a drilling rig the riser string can be retrieved (tripping out) and installed (tripping in) between two and twenty four times.
While certain novel features of this invention shown and described below are pointed out in the annexed claims, the invention is not intended to be limited to the details specified, since a person of ordinary skill in the relevant art will understand that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation may be made without departing in any way from the spirit of the present invention. No feature of the invention is critical or essential unless it is expressly stated as being “critical” or “essential.”
BRIEF SUMMARY
One embodiment of the method and apparatus solves the problems confronted in the art in a simple and straightforward manner. What is provided is an improved method and apparatus for robotically and simultaneously installing or removing a plurality of bolts from the flanged joints of a rig's riser or the like wherein the apparatus includes a plurality of torque stations each having positionable variable torque wrenches for engaging the heads of the plurality of bolts and rotating the bolts during two torque phases including a low-torque phase (which has lower torques but higher rotational speeds), and a high-torque phase (which has higher torques but lower rotational speeds).
In one embodiment is provided a plurality of torque wrenches for rotating a plurality of bolts; a positioning mechanism for positioning and removing each wrench on, with, and/or off of the bolts during each successive cycle of tightening or loosening, and a source of fluid for driving each torque wrench.
In one embodiment is provided a hydraulically actuated riser spider that sits on the floor of the drilling rig such as on top of the gimbal or rotary table. In one embodiment the spider will have a wrench system attached to the spider (which can be welded or bolted on top of the spider).
In one embodiment the wrench system can include a plurality (e.g., six or eight) torquing stations and their operating systems. In one embodiment hydraulics to the riser spider and wrench system can come from a control panel that is located adjacent or next to the spider and wrench system (e.g., on the drill floor). In one embodiment the control panel for the wrench system can be located remote from the torquing stations. In one embodiment the control panel can be located in the drillers shack.
In one embodiment the wrench system can be placed on the spider and be moved with the spider to and from the riser. In one embodiment the wrench system can sit on the spider. In one embodiment the wrench system is connected to (e.g., bolted) to the spider.
In one embodiment operation of the wrench system (and/or spider) will require a single individual standing at the control panel, which can be strategically positioned to observe operation of the tool. In one embodiment no technicians will be required to be on the wrench system and/or spider and/or around the riser joint during flange make-up or break-out. In one embodiment the control panel for the wrench system can be located remote from the torquing stations. In one embodiment the control panel can be located in the driller's shack.
In one embodiment the spider can include retractable bearing surfaces that will hold the upper flange of a riser joint section, and transmit the weight of the riser string and BOP stack to the gimbal top plate or rotary table.
Makeup
In one embodiment the wrench system can comprise six (6) torque stations with the ability to preload all six riser bolts simultaneously during make-up. In one embodiment each torque station will torque each riser bolt to substantially the same torque value. In one embodiment each bolt will be torqued to within an acceptable range of a specified make-up torque value. In one embodiment the acceptable range is within about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 and/or 25 percent of each other. In various embodiments the acceptable range is between about any two of the above specified percentages.
In one embodiment a record (which can be computer generated) can be kept for the makeup value of each bolt in the riser string.
In one embodiment the make up sequence for each riser joint can include the following steps: (a) extending the spider legs (which can be controlled by the control panel) to support a riser string; (b) lowering the riser string until the top flange lands on spider dogs; (c) activating the torquing sequence of the wrench system from the control panel; (d) having the plurality of torquing stations engaging their respective bolts; (e) having the plurality of torquing stations spinning down their respective bolts from the lower flange on the upper riser section to the upper flange on the lower riser section; (f) having the plurality of torquing stations torquing down their respective bolts to a desired torque or torque range; (g) having the plurality of torquing stations disengaging the plurality of bolts and providing clearance for the riser string to be lowered, supported by the spider, and a new riser joint to be stabbed on top of the riser string; (h) lowering the made up portion of the riser string and stabbing a new riser joint on top of the lowered riser string; and (i) extending the spider legs to support the riser string.
In one embodiment the during step “d” the plurality of torquing stations move from retracted positions to radially extended positions. In one embodiment the plurality of torquing stations in step “d” move from upper positions to lower positions. In one embodiment the move from retracted to radially extended positions occurs before the move from upper positions to lower positions.
In one embodiment steps “c” through “g” are completed within less than a set period of time. In one embodiment the set period of time is less than 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, and 1 minutes. In various embodiments the set period of time is between any two of the above specified periods of time.
In one embodiment when first radially extended the upper part of the torque wrench is located within a projected circle of a flotation unit attached to the upper riser section, but also located between the floatation unit and the head of the bolt. In this way the torque wrench clears the floatation attachment without damaging same.
In one embodiment in step “d” the plurality of torquing stations simultaneously first engage the plurality of bolts. In one embodiment in step “d” at least of the plurality of torquing stations first engage the plurality of bolts at a different time then at least one of the other of the plurality of torquing stations.
In one embodiment during step “e” each bolt can freely vertically drop between the threads of the upper flange section and lower flange section of the two riser sections being attached. In one embodiment during this free drop the head of the bolt can remain engaged with the drive socket. In one embodiment the rotational speed of the drive socket can remain constant during the free drop of the bolt. In one embodiment the vertical speed of the drive socket can remain constant during the free drop.
In one embodiment during step “e” the spinning down can include a high speed/low torque rotation of the bolts, and during step “f” the torquing down can include a low speed/high torque rotation of the bolts, where high torque is substantially higher than low torque, and high speed is substantially higher than low speed.
In one embodiment step “e” can include first and second rotational high speeds, where the second rotational high speed is higher than the first rotational high speed, and both first and second rotational high speeds are substantially higher than the low speed of step “f.” In one embodiment the first rotational high speed is 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, and/or 75 percent of the second rotational high speed. In various embodiments the first rotational high speed is between about any two of the above specified percentages in relation to the second rotational high speed.
In one embodiment the rate of vertical speed of the drive socket head of each torquing station changes with the rotational speed of the drive socket. In one embodiment the rate of vertical speed of the drive socket is synchronized with the rotational speed of the drive socket. In one embodiment step “e” can include first and second vertical high speeds, where the second vertical high speed is higher than the first high speed, and both first and second vertical high speeds are substantially higher than the low vertical speed of step “f.” In one embodiment the first vertical high speed is 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, and/or 75 percent of the second vertical high speed. In various embodiments the first vertical high speed is between about any two of the above specified percentages in relation to the second vertical high speed.
In one embodiment first and second rotational high speeds of step “e” can be switched based on the height of the drive socket of each torquing station. In one embodiment first and second rotational high speeds of step “e” can be switched based on the height of the bolt being spun down. In one embodiment the switch can be based on the bolt engaging at least two threads of in the lower flange of the two sections of riser joints being attached. In one embodiment the switch from first to second high speeds can occur simultaneously with a plurality of torquing stations (or with all torquing stations). In one embodiment there can be a pause between the switch from first to second rotational high speeds of all torquing stations. In various embodiments the pause can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the pause can be between any two of the above specified time periods.
In one embodiment the switch from step “e” to step “f” can be switched based on the height of the drive socket of each torquing station. In one embodiment the switch from step “e” to step “f” can be based on the height of the bolt being spun down. In one embodiment the switch can be based on the shoulder of the bolt engaging the upper flange of the two sections of riser joints being attached. In one embodiment the switch from step “e” to step “f” can occur simultaneously with a plurality of torquing stations (or with all torquing stations). In one embodiment there can be a pause between the switch from step “e” to step “f” for all torquing stations. In various embodiments the pause can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the pause can be between any two of the above specified time periods. In one embodiment during the pause the rotational control of the drive sockets are relaxed so as not to attempt to rotate the bolts. In one embodiment the vertical location controls of the drive sockets are relaxed. In one embodiment the radial positioning controls are relaxed.
In one embodiment step “f” can simultaneously start with a plurality of torquing stations (or with all torquing stations). In one embodiment step “f” can simultaneously start with one half of the torquing stations (e.g., torquing stations 110 A-C) and then simultaneously start the second half of the torquing stations (e.g., stations 110 D-F). In one embodiment step “f” can simultaneously start with two of the torquing stations (e.g., torquing stations 110 A-B), and then simultaneously start with a second two of the torquing stations (e.g., stations 110 C-D), and then simultaneously start with a third two of the torquing stations (e.g., stations 110 E-F).
In one embodiment each of the torquing stations can continue in step “f” until the individual torquing station reaches a desired make up torque for its respective bolt. In one embodiment the desired make-up torque can be based on the stalling hydraulic pressure sent to the low speed high torque system of the particular torquing station.
In one embodiment the switch from step “f” to step “g” can occur simultaneously for each of the torquing stations. In one embodiment the switch from step “f” to step “g” can occur simultaneously for a plurality of the torquing stations. In one embodiment the switch from step “f” to step “g” can occur separately for each of the torquing stations, and can be based on the individual torquing stations torquing up its respective bolt to the desired torque.
In one embodiment, a warning signal is sent if one or more torquing stations are not able to torque up its respective bolt to a desired torque. In one embodiment this warning signal is sent after a set period of time after the particular torquing station entered high torque mode (i.e., step “f”).
In one embodiment the during step “f” the plurality of torquing stations move from extended positions to radially retracted positions. In one embodiment the plurality of torquing stations in step “f” move from lower positions to upper positions. In one embodiment the move from lower to upper positions occurs before the move from radially extended to radially retracted positions. In one embodiment, after raising a specified vertical height both radial retraction and raising of the drive socket can occur at a torquing stations. In one embodiment the set height is based on adequately clearing the station's respective head of its made up bolt.
In one embodiment during step “h” the riser string can be supported by the draw works of the rig or the top drive of the rig.
In one embodiment steps “a” through “i” are repeated until enough riser joints or sections are connected to the riser string so that the string can be attached to a well head.
Break-Out
In one embodiment the break out (or riser retrieval) sequence for each riser joint can include the following steps: (a) extending the spider legs/dogs (which can be controlled by the control panel) to support a riser string; (b) raising the riser string until an upper flange lands on spider dogs; (c) activating the torquing sequence of the wrench system from the control panel; (d) having the plurality of torque stations engaging their respective bolts; (e) having the plurality of torque stations breaking out their respective bolts from the upper flange on the lower riser section to the lower flange on the upper riser section; (f) having the plurality of torque stations spinning up bolts from the lower flange; (g) having plurality of torque stations lifting their respective bolts to the upper flange; (h) having the plurality of torque stations spinning their respective bolts into a storage position on the upper flange; (i) having the plurality of torque stations disengaging the plurality of bolts and providing clearance for the riser string to be raised; (j) retrieving the disconnected riser section; (k) raising the remaining portion of the riser string; and (l) extending the spider legs/dogs and supporting the remaining portion on the spider legs/dogs.
In one embodiment the during step “d” the plurality of torquing stations move from retracted positions to radially extended positions. In one embodiment the plurality of torquing stations in step “d” move from upper positions to lower positions. In one embodiment the move from retracted to radially extended positions occurs before the move from upper positions to lower positions. In one embodiment, for at least a portion of step “d” the move vertical and radial movement occur simultaneously.
In one embodiment steps “c” through “i” are completed within less than a set period of time. In one embodiment the set period of time is less than 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, and 1 minutes. In various embodiments the set period of time is between any two of the above specified periods of time.
In one embodiment when radially extended the upper part of the torque wrench is located within a projected circle of a flotation unit attached to the upper riser section, but also located between the floatation unit and the head of the bolt. In this way the torque wrench clears the floatation attachment without damaging same.
In one embodiment in step “d” the plurality of torquing stations simultaneously first engage the plurality of bolts. In one embodiment in step “d” at least of the plurality of torquing stations first engage the plurality of bolts at a different time then at least one of the other of the plurality of torquing stations.
In one embodiment, during step “d” each of the drive sockets at their respective torquing stations can rotate at a first high rotational speed until dropping down to a first vertical height as determined by a height sensor. In one embodiment a first vertical height of the socket head corresponds to the drive socket being located on the bolt head.
In one embodiment each drive socket is rotated at the first rotational speed until the drive socket reaches a second vertical height at which time the high speed low torque motor is stopped and hydraulically relaxed. At this same time vertical movement of the drive socket head is stopped and the hydraulic motor driving the vertical positioning screw is hydraulically relaxed for a set period of time. In one embodiment the set period of time can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment steps “d” and “f” can include first and second rotational high speeds, where the second rotational high speed is higher than the first rotational high speed, and both first and second rotational high speeds are substantially higher than the low speed of step “e.” In one embodiment the first rotational high speed is 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, and/or 75 percent of the second rotational high speed. In various embodiments the first rotational high speed is between about any two of the above specified percentages in relation to the second rotational high speed.
In one embodiment if a first vertical height of drive socket is not achieved within a set period of time at a particular torquing station, at least one locating high torque stroke is made on the drive socket to assist in locating the drive socket on the bolt head and a further check on the vertical height of the socket head is made to determine engagement of the bolt head by the drive socket. In one embodiment after the first iteration of the locating drive stroke is made and the locating high torque stroke is not achieved for the drive socket, a second iteration of locating drive stoke is made and the vertical height of the drive socket is checked. In various embodiment multiple iterations of locating high torque strokes can be made along with checks of the vertical heights of the drive sockets, until engagement of the bolt head is determined.
In various embodiments, before each locating high torque stroke is made, vertical movement of the drive socket is stopped. In one embodiment the vertical control system is also relaxed before each locating high torque stroke is made.
In various embodiments, before each locating high torque stroke is made, rotation of the drive socket is stopped. In one embodiment the high speed rotational motor is also relaxed before each locating high torque stroke is made. In one embodiment pressure is maintained on the rotational motor to assist in positioning each drive socket after it has located the head of its particular riser bolt.
In various embodiments, before each locating high torque stroke is made, the radial positioning system for the drive socket is relaxed.
In one embodiment, a warning signal is sent if one or more torquing stations are not able to be located on their respective bolt head within a set period of time (i.e., step “d”), or within a set number of high torque locating strokes.
In one embodiment, after reaching the first vertical height, the vertical positioning screw moves the drive socket to a second vertical height and holds the drive socket at this height. In one embodiment at the time the vertical positioning screw is stopped, the drive socket head enters a high torque break-out mode (step “e”).
In one embodiment during the high torque break out mode (step “e”), the high torque cylinder is cycled for a set number of cycles. In one embodiment the set number of cycles can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, and 50. In various embodiments the set number of cycles can be within a range of between any two of the above set number of cycles. In one embodiment after its last cycle, the high torque system fully retracts. In one embodiment full retraction is determined by a timing sequence using the high torque hydraulic cylinder, such as extension hydraulic pressure for a set period of time which can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment each of the drive sockets are started in the high torque mode simultaneously (step “e”). In one embodiment step “e” can simultaneously start with a plurality of torquing stations (or with all torquing stations). In one embodiment step “e” can simultaneously start with one half of the torquing stations (e.g., torquing stations 110 A-C) and then simultaneously start the second half of the torquing stations (e.g., stations 110 D-F). In one embodiment step “e” can simultaneously start with two of the torquing stations (e.g., torquing stations 110 A-B), and then simultaneously start with a second two of the torquing stations (e.g., stations 110 C-D), and then simultaneously start with a third two of the torquing stations (e.g., stations 110 E-F).
In one embodiment each of the torquing stations can continue in step “e” until the individual torquing station reaches a desired rotation of the respective bolt being broken out. In one embodiment the desired turn can be based on a number of strokes of the high torque system.
In one embodiment during the high torque mode the drive socket is not moved vertically upward. In this embodiment vertical movement of the drive head is taken up by a vertical angular turning of the torque wrench body. In one embodiment this differential vertical angular turning of the torque wrench body is relieved when the bolt leaves the threads of the lower flange, and is located in the gap between the upper and lower flanges, and is being raised by the lifting fork. In one embodiment the arms of the lifting fork are about set distance below the tip of the drive socket. In one embodiment the set distance is ¼, ⅜, ½, ⅝, ¾, ⅞, 1, 1¼, 1⅜, 1½, 1⅝, 1¾, 1⅞, 2 inches. In various embodiments the set distance can be within a range of between any two of the above specified distances.
In one embodiment the high torque mode is switched to low torque mode after a specified lower back pressure is achieved on the high torque system. In one embodiment a check can be made on the low torque high speed to see if it stalls when breaking out the bolt. In one embodiment the stalling condition is determined based on reaching a specified back pressure for the motor. In one embodiment the stalling condition is determined upon falling below a specified flow rate through the motor.
In one embodiment the switch from high torque to low torque modes for each of the modules are done simultaneously.
In one embodiment the rate of vertical movement of each drive socket head remains constant during vertical lifting of the drive sockets during break out. In one embodiment the rotational speed of the drive socket head remains constant during vertical lifting.
In one embodiment at a set vertical height the lifting fork is extended. In one embodiment full extension of the lifting fork is determined by a timing sequence using the lifting fork hydraulic cylinder(s), such as extension hydraulic pressure for a set period of time which can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment the lifting fork remains extended until the drive socket head reaches a second vertical height at which height the lifting fork is retracted. In one embodiment full retraction of the lifting fork is determined by a timing sequence using the lifting fork hydraulic cylinder(s), such as by retraction hydraulic pressure for a set period of time which can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment rotation of the drive socket is stopped simultaneously with the start of retraction of the lifting fork.
In one embodiment after start of retraction of the lifting fork, the drive socket is sent to a home position for retracted vertical and retracted horizontal positioning.
In one embodiment the retracted vertical mode is achieved before the start of retraction in a horizontal mode. In one embodiment the drive socket is not spun either in high speed or in high torque during retraction. In one embodiment retraction vertically is checked by a vertical height sensor. In one embodiment retraction horizontally is by a pre-set time period. The horizontal radially retracted home position can be checked by a timing sequence using the body slide cylinders, such as retraction hydraulic pressure for a set period of time which can be 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 seconds of retraction pressure. In various embodiments the set period of time can be within a range of between any two of the above set periods of time. Fully retracted positions can be controlled by fully retracted body slide cylinders, or by a retraction catch, or a combination of the two. In one embodiment there can be an adjustable body retraction stop for each body module in the retraction step.
In one embodiment the rate of vertical speed of the drive socket head of each torquing station changes with the rotational speed of the drive socket. In one embodiment the rate of vertical speed of the drive socket is synchronized with the rotational speed of the drive socket.
In one embodiment the during step “i” the plurality of torquing stations move from extended positions to radially retracted positions. In one embodiment the plurality of torquing stations in step “i” move from lower positions to upper positions. In one embodiment the move from lower to upper positions occurs before the move from radially extended to radially retracted positions. In one embodiment, after raising a specified vertical height both radial retraction and raising of the drive socket can occur at each torquing stations. In one embodiment the set height is based on adequately clearing the station's respective head of its broken out bolt.
In one embodiment during steps “j” and “k” the broken out riser flange is removed, and the riser is raised until a new flange is revealed to be broken out. In one embodiment the above specified steps are repeated for newly revealed flange connection.
In one embodiment the above specified steps are repeated until the length of riser has been removed.
In one embodiment during step “k” the riser string can be supported by the draw works of the rig or the top drive of the rig.
In one embodiment steps “a” through “l” are repeated until the entire riser is retrieved.
General Operation
Multiple Bolts Simultaneously
In one embodiment the method includes simultaneously tightening (making up) or loosening (breaking out) a plurality of bolts.
In one embodiment a plurality of at least 3, 4, 5, and/or 6 bolts are simultaneously tightened or loosened.
In one embodiment is provided a plurality of independently operated torque drivers. In one embodiment a plurality of at least 3, 4, 5, or 6 torque drivers are provided.
In one embodiment the plurality of bolts are in a bolt circle. In one embodiment the plurality of bolts are symmetrically and radially spaced apart by about 60 degrees each.
In one embodiment the plurality of bolts will or have connected two riser sections or joints of a riser string.
In one embodiment a plurality of drivers are provided each individually positionable both generally laterally and/or vertically.
In one embodiment a plurality of at least 3, 4, 5, and/or 6 drivers are positionable together to tighten (make up) or loosen (break out) respective bolts.
Method Steps at Individual Torque Stations
In one embodiment the method includes the driver moving vertically upward or downward when the bolt is being loosened or tightened.
In one embodiment a visual check is made of the existence and/or position of each bolt to be tightened (make up) or loosened (break out). If the visual check is satisfied the making up or breaking out sequences can begin.
Tightening (or Making Up)
In one embodiment a second section of riser is positioned next to a first section of riser, the second section of riser including a plurality of bolts.
In one embodiment a plurality of drivers are moved horizontally closer to a respective plurality of bolts to be tightened (made up).
In one embodiment a plurality of drivers are moved vertically closer to the respective plurality of bolts to be tightened (made up).
In one embodiment a plurality of drivers are turned to tighten the respective plurality of bolts to be tightened (made up).
In one embodiment a plurality of high speed/low torque systems control the turning of the respective plurality of bolts to be tightened. In one embodiment control can be switched between high and low torque systems as many times as needed or desired.
In one embodiment a plurality of low speed/high torque systems can transition to control over the turning of the respective plurality of bolts to be tightened. In one embodiment control can be switched between high and low torque systems as many times as needed or desired.
In one embodiment a plurality of drivers are moved vertically downward with the respective plurality of bolts to be tightened (made up) as the bolts move downward.
In one embodiment a plurality of drivers are moved vertically downward at a different vertical speeds with the respective plurality of bolts to be tightened (made up) as the bolts move downward.
In one embodiment each driver can be independently controlled in both controlling driver (high or low speed), and speed of vertical movement.
In one embodiment the first and second sections of risers are lowered and a third riser joint or section is positioned next to the second riser joint or section, and the third riser joint or section including a plurality of bolts to be made up.
In one embodiment the above tightening steps are repeated until a riser string spans from adjacent the sea floor (e.g., wellhead or blow out preventers) to the rig or platform.
In one embodiment the method includes the step of allowing a bolt to drop a distance while the bolt head is still retained in the driver. In one embodiment multiple bolts are allowed to drop a distance.
In one embodiment, after each of the plurality of bolts have been spun down so that shoulder to shoulder contact exists, each torque station simultaneously begins the final high torque makeup of their respective bolts. Simultaneously performing the final high torque make-up is believed to provide a more uniform make up connection between the riser sections or joints (e.g., keeping the flanges of the riser joints or section more parallel).
In one embodiment, at each torque station, the tightening cycle for each bolt is stopped after a desired torque on the bolt is reached (e.g., the high torque driver system stalls based on supply pressure), and the driving system is removed from the bolt.
In one embodiment the method includes the driver moving vertically downward when the bolt is being tightened.
In one embodiment, the retraction and disengagement of the driving system at each torque station includes the step of raising the driver so that it can at least clear the bolt head and moving away the driver radially from the bolt.
In one embodiment the vertical height of the system is limited to prevent the system from damaging the floatation/insulation found on each riser section or joint.
Loosening (or Breaking Out)
In one embodiment a plurality of drivers are moved horizontally closer to a respective plurality of bolts to be loosened (broken out) from second and first sections of riser.
In one embodiment a plurality of drivers are moved vertically closer to the respective plurality of bolts to be loosened (broken out).
In one embodiment a plurality of drivers are turned to loosen the respective plurality of bolts to be loosened (broken out).
In one embodiment a plurality of high speed/low torque systems control the turning of the respective plurality of bolts to be loosened. In one embodiment control can be switched between high and low torque systems as many times as needed or desired.
In one embodiment a plurality of low speed/high torque systems can transition to control over the turning of the respective plurality of bolts to be loosened. In one embodiment control can be switched between high and low torque systems as many times as needed or desired.
In one embodiment a plurality of drivers are moved vertically upward with the respective plurality of bolts to be loosened (broken out) as the bolts move upward.
In one embodiment a plurality of drivers are moved vertically upward at a different vertical speeds with the respective plurality of bolts to be loosened (broken) as the bolts move upward.
In one embodiment each driver can be independently controlled in both controlling driver (high or low speed), and speed of vertical movement.
In one embodiment the method includes the step of using a fork to lift a bolt to a vertical distance while the bolt head is still retained in the driver.
In one embodiment the driving cycle of each bolt is stopped after a desired height of the bolt is reached (e.g., the head of the bolt reaches a specified storage height), and the driving system is disengaged from the bolt.
In one embodiment the first riser section or joint is retrieved, and the remaining riser string is raised to reveal another riser section or joint to be retrieved, along with another plurality of bolts to be loosened.
In one embodiment the above retrieval steps are repeated until each riser section or joint in the riser string is retrieved.
In one embodiment the removal of the driving system includes the step of raising the driver so that it can at least clear the bolt head and moving away the drive radially from the bolt.
In one embodiment the method includes the driver moving vertically upward when the bolt is being loosened.
In one embodiment, at each torque station, the loosening cycle for each bolt is stopped after a desired height for the bolt is reached (e.g., a specified storage height for the bolt), and the driving system is disengaged and retracted from the bolt for the next loosening cycle.
In one embodiment, the retraction and disengagement of the driving system at each torque station includes the step of raising the driver so that it can at least clear the bolt head and move away the driver radially from the bolt.
In one embodiment the vertical height of the system is limited to prevent the system from damaging the floatation/insulation found on each riser section or joint.
Type of Control
In one embodiment a plurality of torque drivers are robotically controlled. In one embodiment a plurality of at least 3, 4, 5, and/or torque drivers are controlled. In one embodiment the control is simultaneous.
In one embodiment a plurality of torque drivers are computer controlled. In one embodiment a plurality of at least 3, 4, 5, and/or torque drivers are controlled. In one embodiment the control is simultaneous.
In one embodiment a plurality of torque drivers are automatically controlled. In one embodiment a plurality of at least 3, 4, 5, and/or torque drivers are controlled. In one embodiment the control is simultaneous.
In one embodiment a plurality of torque drivers are remotely controlled. In one embodiment a plurality of at least 3, 4, 5, and/or torque drivers are controlled. In one embodiment the control is simultaneous.
Items which are Controlled
Position of Driver
In one embodiment the control includes controlling the position of the driver. In one embodiment each of the plurality of torque drivers are positionable laterally (or radially towards or away from its respective bolt) and/or vertically (toward or away from its respective bolt).
In one embodiment each torque driver has a controlled vertical downward motion when tightening (making) up bolt. In one embodiment the controlled vertical motion of the driver is performed by a lifting and lower mechanism.
In one embodiment the lifting and lowering mechanism approximates the vertical movement of the bolt being tightened or loosened. In one embodiment each torque driver can move vertically substantially same as bolt which is engaged by the torque driver.
In one embodiment the vertical distance moved by the bolt is approximated by calculating the number of turns of the bolt and the pitch of the threads for the bolt. In this manner the vertical movement can be calculated by multiplying the number of turns of the bolt by the pitch. In one embodiment, at each torque station, the vertical speed of the driver is slightly greater than the vertical speed of the bolt being tightened, and motor controlling vertical movement of the driver stalls when it overshoots the vertical distance traveled by the bolt, and restarts when the bolt again moves ahead of the driver. In this manner the driver can be continuously maintained on the head of the bolt during tightening.
In one embodiment, at each torque station, the vertical speed of the driver is slightly lower than the vertical speed of the bolt being lowered, and motor controlling vertical movement of the driver can be speeded up when the bolt overshoots the vertical distance traveled by the driver. In this manner the driver can be continuously maintained on the head of the bolt during loosening.
In one embodiment the driver is slidingly connected to rig floor such that it can move in a substantially horizontal direction. In one embodiment a track system is used to guide movement of the driver. In one embodiment a linear bear or rod and bushing system is used.
Rotational Speed and Torque on Driver
In one embodiment at each torque station is provided torque drivers with both a high torque driving system and a low torque driving system. In one embodiment the low torque driving system drives at a faster rotational speed compared to the high torque driving system. In one embodiment both high torque driving system and low torque driving system are operatively connected to same driver for bolt.
In one embodiment the low torque driver system can have a plurality of driving speeds (such as fast, medium, and slow speeds), where the plurality of speeds are faster than the driving speed of the high torque driving system.
In one embodiment the both the high speed/low torque system and low speed high torque system are simultaneously operatively connected to the driver. In this vein when the high speed/low torque assembly is operating the driver, the low speed/high torque system will not inhibit movement of the driver because of a reverse ratcheting effect. Similarly, when the low speed/high torque system controls the driver (e.g., the high speed/low torque motor has stalled or been set to a non-energized state), the high speed/low torque system allows operation of the low speed/high torque assembly by turning along with the driver being turned by the low speed/high torque assembly.
In one embodiment each wrench includes a high speed/low torque motor controlling the high speed/low torque phase.
In one embodiment the rotational speed of the high speed/low torque driver is about 100 revolutions per minute. In one embodiment the high speed driver can have a programmable lower speeds such as 5 or 10 percent of the max speed.
In one embodiment each wrench includes a low speed/high speed torque wrench controlling the low speed/high torque phase.
In one embodiment one or more of the wrenches include mechanisms for automatically switching between the high speed/low torque phases and the low speed/high torque phases based on the individual torque requirements of the plurality of bolts being tightened or loosened.
Both Systems Energized Simultaneously
In one embodiment, both the high speed/low torque system can be energized simultaneously with the low speed/high torque system (because neither driving system in a non-operating state, or in a reduced operating state, will not interfere with the other driving assembly in the operating state).
In this embodiment switchover between the two systems depends on which system is controlling rotation of the bolt at any given instant.
In one embodiment both high and low torque drivers continue for substantially all of the processes when tightening (making up) or loosening (breaking out) a plurality of bolts.
Switchover by Height
In one embodiment transition between the high torque driver and low torque driver occurs when height of driver reaches a predetermined position.
In one embodiment both high and low torque drivers continue for predetermined amounts of process for (making up) or loosening (breaking out) a plurality of bolts.
In one embodiment the predetermined amount for continuance of high with low is one predetermined amount and the predetermined amount for continuance of low with high is a second predetermined amount.
Switchover by Pressure
In one embodiment the back pressure of the high speed/low torque motor can be sensed to determine a switchover point to the low speed/high torque system. This is a switchover can be made when the high speed/low torque motor is determined to be in a stalled condition.
In one embodiment the back pressure of the low speed/high torque assembly can be sensed to determine a switchover point to the high speed/low torque system. This is a switchover can be made when the back pressure in the low speed/high torque system is determined to be below a specified minimum pressure. In one embodiment the high speed low torque system can be energized/pressurized (but in a stalled condition) even when the low speed/high torque system is controlling the driver, but the low speed/high torque system is set to non-energized condition when it is determined that the high speed/low torque motor is no longer in a stalled condition (e.g., the back pressure from the high speed/low torque motor drops below a specified stalled pressure).
In one embodiment the stalling of the high speed/low torque motor in a particular wrench of the plurality of wrenches causes a transition to the low speed/high torque phase for such particular wrench.
In one embodiment falling below a specified resistance torque on the low speed/high torque wrench causes a transition to the high speed/low torque phase.
Structure of Wrenches
In one embodiment, at each torque station, the torque driver can comprise:
a body having a high torque wrench assembly, the high torque assembly being operatively connected to a main driver; a high torque wrench assembly, the high torque assembly being operatively connected to the main driver and rotating the main driver; and the driver being adjustable both in lateral and vertical directions, the lateral direction being substantially perpendicular to the vertical direction.
In one embodiment each torque driver includes a low torque assembly, the low torque assembly being operatively connected to the main driver and rotating the main driver, wherein the maximum torque of the low torque assembly is less than the maximum torque of the high torque assembly and the speed of the low torque assembly is greater than the speed of the high torque assembly.
One Way/Two Way Torque Wrench
In one embodiment a plurality of one way high torque wrench drivers are used.
In one embodiment to switch from tightening for (making up) or loosening (breaking out) body of toque wrench can be flipped.
In one embodiment a plurality of two way torque wrenches are used to avoid the necessity of turning the plurality of torque wrench bodies between loosening and tightening modes.
Fork Lift for Lifting Bolt During Loosening (or Breakout)
In one embodiment a bolt lifting mechanism is operatively connected to each driver.
In one embodiment the bolt lifting mechanism is slidingly connected to body of torque wrench.
In one embodiment the bolt lifting mechanism is controlled through a piston, or through a plurality of pistons.
In one embodiment the bolt lifting mechanism vertically travels with body of torque wrench.
In one embodiment the bolt lifting mechanism is a fork
Final Torque
In one embodiment a check is made regarding the final torque on each bolt (e.g., 32 A-F) during the tightening process. Such final torque can be calculated based on the back pressure (e.g., the stalling or back pressure of the hydraulic piston 740 ) during the high torque phase. In one embodiment a check is made against a minimum torque (such as by a calculation of the torque from the stalling or back pressure) and if the minimum torque is not achieved on one or more of the pistons 740 A-F and cylinders 700 A-F a warning signal is made. In one embodiment a record is kept of the torquing on each bolt during the make up (and/or break out procedure) for a substantial portion (or the entire riser).
In one embodiment a maximum of 40,000 foot pounds of torque can be obtained. In one embodiment the final torque of the driver is about 18,000 foot pounds.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS 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 top view of the rig floor with the spider dogs in an extended state supporting the riser string with the upper flange of a riser joint exposed.
FIG. 2 is a perspective and sectional view of the spider showing the spider dogs in an extended state.
FIGS. 3 through 10 show various sequence steps in a make up process for one of the torque stations.
FIG. 3 is a top view showing one embodiment of the torque wrench system during make up with all six of the torque stations ( 110 A-F) in horizontally retracted states (and station 110 A in a partially broken out view).
FIG. 4 is a top view showing one embodiment of the torque wrench system during make up with all six of the torque stations ( 110 A-F) in horizontally extended states (and station 110 A in a partially broken out view).
FIG. 5A is a schematic side view one of the torque stations ready for the beginning of a make up or break out sequence as the driver socket is completely retracted horizontally and moved to its highest vertical position which will clear a bolt previously placed in a storage condition for a riser joint along with being below the lowest point of the insulation or floatation for the upper riser section or joint. FIG. 5B is a top view of the torque station of FIG. 5A shown in partially broken out view.
FIG. 6A is a schematic side view the torque station of FIG. 5 where the driver socket has moved horizontally over a bolt and is rotating for tightening, the driver socket is also moving downwardly, and is about to engage the bolt head. FIG. 6B is a top view of the torque station of FIG. 6A shown in partially broken out view.
FIG. 7A is a schematic side view of the torque station of FIG. 5 where driver socket has engaged the bolt and begun to spin down the bolt through the upper flange and into the gap. FIG. 7B is a top view of the torque station of FIG. 7A shown in partially broken out view.
FIG. 8A is a schematic side view of the torque station of FIG. 5 after the driver socket has spun down the bolt, and the bolt is now allowed a free fall through the gap between the flanges, and the head of the bolt has vertically dropped in relation to the drive socket. FIG. 8B is a top view of the torque station of FIG. 8A shown in partially broken out view.
FIG. 9A is a schematic side view of the torque station of FIG. 5 after the driver socket has spun down the bolt, allowed a free fall of the bolt through the gap between the flanges, and spun down the bolt to the lower flange by about two threads in the lower flange. FIG. 9B is a top view of the torque station of FIG. 9A shown in partially broken out view.
FIG. 10A is a schematic side view of the torque station of FIG. 5 after the driver socket has spun down the bolt until shoulder to shoulder contact between the upper flange and the bolt head has occurred, and the torque station to go into a high torque mode where the piston and drive gear controls rotation of the driver. After the desired make up torque is achieved the driver socket will be moved upward and retracted to the position shown in FIG. 5 and be ready for the next make up cycle. FIG. 10B is a top view of the torque station of FIG. 10A shown in partially broken out view.
FIGS. 11 through 21 show various sequence steps in a break out process for one of the torque stations.
FIG. 11 is a top view showing one embodiment of the torque wrench system during break out with all six of the torque stations ( 110 A-F) in horizontally retracted states (and station 110 A in a partially broken out view).
FIG. 12 is a top view showing one embodiment of the torque wrench system during break out with all six of the torque stations ( 110 A-F) in horizontally extended states (and station 110 A in a partially broken out view).
FIG. 13 is a schematic side view one of the torque stations ready for the beginning of a break out sequence as the driver socket is completely retracted horizontally and moved to its highest vertical position which will clear the bolt being broken out along with being below the lowest point of the insulation or floatation for the upper riser section or joint.
FIG. 14 is a schematic side view one of the torque stations moving to a locating position for the drive socket on the bolt head and showing how the drive socket has been radially extended and also moved vertically down before being located above the head of the bolt to be broken out.
FIG. 15 is a schematic side view of the torque station of FIG. 13 illustrating the step of locating the drive socket on the bolt head for break out. Both low torque rotation along with high torque stroking is schematically shown for locating the drive socket on the bolt head prior to the high torque break out step.
FIG. 16 is a schematic side view of the torque station of FIG. 13 where the driver socket is engaged with the bolt, and the bolt has shoulder to shoulder contact with the upper flange, and the driver socket or socket is beginning the breakout process so that the torque station will go into the high torque mode with the drive gear.
FIG. 17 is a schematic side view of the torque station of FIG. 13 where the driver tip or socket has partially broken out the bolt, spun out the bolt to where a free spinning mode has been entered because the threads of the bolt are between the threads in the upper and lower flanges.
FIG. 18 is a schematic side view of the torque station of FIG. 13 where the lifting fork has engaged the freely spinning bolt and begun lifting the bolt so that its threads can engage the threaded portion of the upper flange.
FIG. 19 is a schematic side view of the torque station of FIG. 13 where the lifting fork has lifted the bolt enough to now engage the threaded portion of the upper flange, and the lifting fork can later retract.
FIG. 20 is a schematic side view of the torque station of FIG. 13 where the lifting fork has retracted and the bolt has been additionally spun up compared to its position in FIG. 19 , and is now located in the bolt's vertical position for retrieval of the section riser.
FIG. 21 is a schematic side view of the torque station of FIG. 13 where the driver socket has stopped rotating and has been vertically raised above the head of the bolt.
FIG. 22 is a schematic side view of the torque station of FIG. 13 where the driver socket is completely retracted both vertically and horizontally and ready for the start of the next break out cycle.
FIG. 23 is a front perspective view of a torque station where the wrench is set for tightening, and shown in a horizontally retracted position with the drive socket in the top most vertical position, and also showing the lifting fork in a retracted position.
FIG. 24 is a front perspective view of the torque station of FIG. 23 now shown in a horizontally extended position, and the lifting fork is also shown in an extended position.
FIG. 25 is a rear perspective view of the torque station of FIG. 23 now shown in a horizontally extended position.
FIG. 26 is a side perspective view of the wrench and elevator portion of the torque station of FIG. 23 where the wrench is set for tightening, and the lifting fork is shown in an extended position.
FIG. 27 is a side perspective view of the wrench and elevator portion of FIG. 26 but shown from the opposite side.
FIG. 28 is a top perspective view of the elevator portion shown in FIG. 26 .
FIG. 29 is a bottom perspective view of the elevator portion shown in FIG. 26 however with the lifting fork cylinders omitted for clarity.
FIG. 30 is an exploded perspective view of the high torque wrench portion.
FIG. 31 is a top perspective view of a portion of the high torque driver of the wrench of FIG. 30 .
FIG. 32 is an exploded perspective view of the high torque driver of the wrench of FIG. 30 .
FIG. 33 is a enlarged top view illustrating the cylinder and piston arrangement of the high torque driver of FIG. 30 .
FIG. 34 is a top view of the high torque driver of the wrench of FIG. 30 where the piston is in a completely retracted position.
FIG. 35 is a top view of the high torque driver of the wrench of FIG. 30 where the piston is in the middle of a stroke.
FIG. 36 is a top view of the high torque driver of the wrench of FIG. 30 where the piston is in a completely extended position.
FIG. 37 is a perspective view of a drive socket which can be operatively connected to the high speed low torque driver along with the high torque low speed driver.
FIG. 38 is a top view of the socket of FIG. 37 .
FIG. 39 is a bottom view of the socket of FIG. 37 .
FIGS. 40 and 41 are respectively top and bottom views of the high torque driver shown in FIG. 30 .
FIG. 42 is a top perspective view of the sliding housing, reaction bar, and vertical lifting and lowering mechanism of FIG. 23 .
FIG. 43 is a bottom perspective view of the sliding housing, reaction bar, and vertical lifting and lowering mechanism of FIG. 23 .
FIG. 44 is a top perspective view of the base for the sliding housing of FIG. 30 .
FIG. 45 is a schematic diagram of the hydraulic circuits controlling the high torque driver, low torque driver, vertical lifting and lowering mechanism, sliding housing, and lifting fork during make up mode.
FIG. 46 is a schematic diagram of the hydraulic circuits controlling the high torque driver, low torque driver, vertical lifting and lowering mechanism, sliding housing, and lifting fork during break out mode.
FIG. 47 is a schematic diagram of the hydraulic circuits for the hydraulic power unit.
FIG. 48 is a schematic side view of the step of making up a riser string of lowering a second riser section onto a first riser section where the first riser section along with the rest of the riser string is supported by the spider.
FIG. 49 is a closeup side view of where the second riser section has been placed on top of the first riser section showing a plurality of riser bolts ready to be tightened with the spider supporting the riser string and a plurality of torque modules are located in their home position.
FIG. 50 is a side view schematically indicating that the plurality of torque modules shown in FIG. 49 have extended are making up the plurality of riser bolts while the riser string is being supported by the spider.
FIG. 51 is a side view schematically indicating that the plurality of torque modules have completed the make up of the plurality of riser bolts and such modules are retracting to their home position.
FIG. 52 shows the now made up joint between the second and first riser sections is being lowered by the rig lifting elevator after the spider has been retracted.
FIG. 53 is a side view of the now made up joint between the second and first riser sections is being lowered by the rig lifting elevator (which supports the string by attachment to the upper flange of the second riser section) after the spider has been retracted.
FIG. 54 is a side view of the elevator supporting the riser string by the upper flange of the second riser section and located this upper flange in the spider for support.
FIG. 55 is a close up view of the elevator supporting the riser string by the upper flange of the second riser section and having placed the upper flange on the spider for support.
FIG. 56 is a close up view of the elevator being removed from the upper flange of the second riser section.
FIG. 57 is a perspective view of all six torque modules in their home positions and set up in the break out mode.
DETAILED DESCRIPTION
Detailed descriptions of one or more preferred embodiments 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 any appropriate system, structure or manner.
U.S. Pat. Nos. 7,146,880; 6,553,873; and 6,382,059 are incorporated herein by reference.
U.S. patent application Ser. No. 09/525,465, filed Mar. 13, 2000 is incorporated herein by reference.
Plurality of Wrenches
Hydraulic wrench apparatus 100 can comprise a plurality of torque stations each of which can include dual high and low torque wrenches (e.g., 110 A, 110 B, 110 C, 110 D, 110 E, and 110 F) for tightening (making up) or loosening (breaking out) a plurality of bolts.
Each wrench (e.g., 110 A, 110 B, 110 C, 110 D, 110 E, and 110 F) can be constructed in a substantially similar manner and, therefore, only one wrench 110 will be described below.
As indicated by vertical arrows 64 and 63 and horizontal arrows 60 and 61 , each wrench 110 (and driver 1000 ) can be robotically moved in both vertical and horizontal directions allowing the wrenches to be cycled in and out during successive tightening or loosening activities of bolts in different sections of a riser 40 .
Generally, each wrench 110 can include a wrench 400 which is adjustably mounted in a sliding housing 140 . Wrench 400 can be adjusted vertically relative to sliding housing 140 as schematically indicated by arrows 64 and 63 . Additionally, sliding housing 140 can be adjustably mounted on a base 300 . Sliding housing 140 can be adjusted horizontally relative to base 300 as schematically indicated by arrows 60 and 61 . In this manner driver tip or socket 1010 of wrench 400 can be both vertically and horizontally adjustable when tightening or loosening a bolt 32 .
In a preferred embodiment hydraulic wrench apparatus 100 will include six (6) torque wrenches (e.g., 110 A, 110 B, 110 C, 110 D, 110 E, and 110 F) spaced radially apart in sixty degree increments around the bolt circle of two riser sections.
Structural Components
FIGS. 1 through 47 show one embodiment of wrench 100 having a plurality of torque stations.
FIG. 1 is a top view of the rig floor 20 with the spider dogs in an extended state supporting the riser string 40 with the upper flange 47 of a riser joint 46 exposed.
FIG. 2 is a perspective and sectional view of the spider 50 showing the spider dogs in an extended state.
FIGS. 3 and 4 are top views showing one embodiment of the torque wrench system 100 in horizontally retracted and extended states in a make up mode. Preferably, all six stations ( 110 A, 110 B, 110 C, 110 D, 110 E and 110 F) will simultaneously extend and retract.
FIGS. 5 through 10 show various sequence steps for one of the torque stations 110 during make up. Because all six torque stations ( 110 A, 110 B, 110 C, 110 D, 110 E and 110 F) are substantially the same and operate similarly, only one representative torque station 110 will be described in detail. However, it should be understood that the detail description of the one applies equally to all six.
FIGS. 11 and 12 are top views showing one embodiment of the torque wrench system 100 in horizontally retracted and extended states in a break out mode. Preferably, all six stations ( 110 A, 110 B, 110 C, 110 D, 110 E and 110 F) will simultaneously extend and retract.
FIGS. 13 through 22 show various sequence steps for one of the torque stations 110 during break out. Because all six torque stations ( 110 A, 110 B, 110 C, 110 D, 110 E and 110 F) are substantially the same and operate similarly, only one representative torque station 110 will be described in detail. However, it should be understood that the detail description of the one applies equally to all six.
FIGS. 23 through 44 are perspectives view of various components of one of the torque stations 110 in multiple positions and performing multiple functions.
FIG. 23 is a front perspective view of a torque station 110 where the wrench 400 is set for tightening, and shown in a horizontally retracted position (direction of arrow 61 ) with the driver tip 1010 in the top most vertical position (schematically in the direction of arrow 64 ), and also showing the lifting fork 1400 in a fully retracted position (in the direction of arrow 61 ).
FIG. 24 is a front perspective view of torque station 110 now shown in a horizontally extended position (direction of arrow 60 ), and the lifting fork 1400 is also shown in an extended position (direction of arrow 60 ).
FIG. 25 is a rear perspective view of torque station 110 now shown in a horizontally extended position (direction of arrow 60 ).
FIG. 26 is a side perspective view of the wrench portion 400 of torque station 110 where the wrench 400 is set for tightening, and the lifting fork is shown in an extended position (arrow 1402 ). FIG. 27 is a side perspective view of the wrench portion 400 but shown from the opposite side.
FIG. 28 is a top perspective view of the high speed/low torque driver 1200 of wrench 400 , and shown operatively connected to driver 1000 by means of belt 1220 . Idler pulleys 1222 can maintain proper tension of belt 1220 . FIG. 29 is a bottom perspective view of high speed/low torque driver 1200 showing motor 1210 which is operatively connected to driver 1000 through belt 1220 . Although not shown one or more hydraulic cylinders and pistons can be operatively connected to fork 1400 to extend it (arrow 1402 ) or retract it (arrow 1404 ). Tracks 1252 , 1254 , 1256 , and 1258 of housing 1230 slidably connected to tracks 192 , 194 , 196 , and 198 of sliding housing 140 allowing housing 1230 to vertically slide (arrows 64 and 63 ) relative to sliding housing 140 (see FIGS. 23-25 ).
FIG. 30 is an exploded perspective view of a portion of the high torque driver 590 of wrench 400 . FIG. 31 is an assembled perspective view of the high torque driver 590 . FIG. 32 is a perspective exploded view of the high torque driver 590 .
FIG. 37 is a side perspective view of driver 1000 which can include tip or socket 1010 , opening 1020 for bolt 32 , and a maximum depth of penetration 1030 for the head of bolt 32 . FIGS. 38 and 39 are respectively top and bottom views of the driver 1000 .
FIG. 40 is a perspective view of wrench body 406 used in torque station 110 . FIG. 41 is another perspective view of wrench body 406 taken from the opposite side as that shown in FIG. 40 .
FIG. 42 is a front perspective view of the sliding housing 140 , reaction bar 500 , and vertical lifting and lowering mechanism 1300 . FIG. 43 is a bottom perspective view of sliding housing 140 , reaction bar 500 , and vertical lifting and lowering mechanism 1300 . FIG. 44 is a top perspective view of base 300 for sliding housing 140 .
The individual components and their operations will be described in more detail below.
Wrench 110 can comprise a body 406 including a cylinder 700 for hydraulically reciprocating a piston 740 and piston rod 750 . Piston 740 being operably connected to a driver 1000 . The connection between the piston 740 and driver 1000 can be a ratcheting mechanism comprising a drive gear 600 .
The high torque phase can be achieved by activation of hydraulic cylinder 700 pivotally connected to wrench body 406 by pivot pin 734 . Piston rod 750 is connected to piston rod tip 760 which, in turn, is respectively pivotally connected to first and second drive plates 800 , 810 at bores 850 , 852 . First and second drive plates 800 , 810 are pivotally connected to drive pawl 900 through bores 860 , 870 . Drive pawl 900 is operatively connected to drive gear 600 by a plurality of angular gear teeth 610 and drive pawl springs 920 . Drive plate extension 820 biases springs 920 against drive pawl 900 . Driver 1000 is connected to drive gear 600 through correspondingly shaped opening 620 . Extension of piston rod 750 rotates first and second drive plates 800 , 810 ; thereby rotating drive pawl 900 , thereby engaging drive gear 600 and turning driver 1000 rotating driver tip or socket 110 and finally engaging bolt 32 .
Drive bushings/bearings 880 and 882 are operatively connected to driver 1000 through bores 881 and 883 . Drive bushings 880 and 882 fit into bores 460 and 470 of wrench body 406 . Drive bushing/bearings 880 and 882 reduce friction and act as a bearing surface during rotation of driver 1000 for both high speed and high torque phases.
Wrench 400 can include a reaction bar 500 which provides a reacting force in opposition to the torque applied by driver 1000 on bolt 32 . Driver 1000 can be operably connected to a driver tip or socket 1010 which itself connects to threaded fastener 32 . In one embodiment there can be further included exchangeable socket tips mountable on driver 1000 for engaging a head of a threaded fastener 32 which are of different sizes.
Sliding housing 140 can slide radially, laterally, or horizontally relative to base 300 (in the directions of arrows 60 and 61 ). Sliding housing 140 can comprise top 142 , bottom 144 , front 146 , and rear 146 . Sliding housing can include first and second side walls 152 , 154 , which are connected by horizontal braces 180 and 170 . On the bottom 144 can be plurality of foot connectors 154 , 155 , 156 , and 157 , each of which can include a sliding bore.
Sliding housing 140 can include reaction bar or shaft 500 which spans between brace 170 and removable brace 160 .
Side wall 150 can include tracks 192 and 194 . Substantially opposite of tracks 192 and 194 can be tracks 196 and 198 located on side wall 152 . Male tracks 192 , 194 , 196 , and 198 can slidably connect wrench 400 located on top of housing 1230 (in a vertical direction and cooperating with female tracks 1252 , 1254 , 1256 , and 1258 ) to sliding housing 140 . Wrench 400 will also slide vertically relative to reaction bar or shaft 500 through cooperating bore 498 .
Sliding housing 140 can be adjustably mounted on a base 300 through foot connectors 154 , 155 and 156 , 157 being slidably connected to shafts 352 and 354 . Sliding housing 140 can be adjusted horizontally relative to base 300 as schematically indicated by arrows 60 and 61 . A pair of hydraulic cylinders and pistons (not shown) can be connected to sliding housing 140 and rear plate 358 such that extension of the cylinders pushes sliding housing 140 in the direction of arrow 60 (at least until the fully extended position where front plate 356 can stop further movement in the direction of arrow 60 ) and retraction of the cylinders pulls sliding housing 140 in the direction of arrow 61 . In one embodiment a maximum forward movement adjustment mechanism (such as a set screw) can be provided on front plate 356 to limit the amount of horizontal movement of sliding assembly (and driving tip or socket 1010 ) in the direction of arrow 60 . For example, forward movement in the direction of arrow 60 can be stopped when foot 156 and/or 157 hits forward plate 356 . In one embodiment the distance of forward movement in the direction of arrow 60 can be controlled by measuring the amount of extension of the hydraulic cylinders pushing sliding housing 140 .
Vertical lifting and lowering mechanism 1300 can comprise motor 1310 and screw 1330 . Hydraulic motor 1310 can be operatively connected to screw 1330 . Screw 1330 can be operatively connected to wrench 400 through threaded area 1242 of housing 1230 . Rotating in the direction of arrow 1332 (clockwise) would lower wrench 400 (in the direction of arrow 63 ), while rotating in the opposite direction (i.e., in the direction of arrow 1334 or counterclockwise) would raise wrench 400 (in the direction of arrow 64 ). Although not shown in the drawings, in one embodiment vertical lifting and lowering mechanism can comprise a cylinder and piston arrangement operatively connected to wrench 400 where extension of the cylinder raises wrench 400 (in the direction of arrow 64 ) and retraction of the cylinder lowers wrench 400 (in the direction of arrow 63 ). However, given the small clearance between wrench 400 and base 300 when wrench 400 is in its lowest position a telescoping arrangement may be required or the piston connection being made at the rear of wrench body 406 . The vertical positioning mechanism can vertically position the drive head independent from the operation of the high torque and low torque wrenches.
In one embodiment a bolt lifting mechanism 1400 is provided. Bolt lifting mechanism 1400 can comprise lifting fork 1410 and plate 1420 . Lifting fork 1410 can be slidingly connected to wrench 400 via housing 1230 by plate 1420 sliding in between tracks 1430 and 1432 . A pair of hydraulic cylinders and pistons (not shown) can be connected to plate 1420 and extension of the cylinders pushes fork 1410 in the direction of arrow 1402 (at least until the fully extended position where fork 1410 is blocked from further movement in this direction such as by contacting bolt 32 ) and retraction of the cylinders pulls fork 1410 in the direction of arrow 1404 . In one embodiment a maximum forward movement adjustment mechanism (such as a set screw) can be provided to limit the amount of horizontal movement of fork 1410 in the direction of arrow 1402 . In one embodiment the distance of forward movement in the direction of arrow 1402 can be controlled by measuring the amount of extension of the hydraulic cylinders pushing fork 1410 .
High and Low Torque Portions
Each wrench 110 can have both high torque and low torque driving mechanisms. Each wrench 110 can have a high speed/low torque portion 1200 for speeding up the tightening or loosening process until a higher torque is required/desired. When a higher torque is desired each wrench 110 can include a low speed/high torque portion 590 which can address final make-up torquing up of bolts 32 or the initial break out torque for breaking out bolts 32 .
In one embodiment the high and low torque portions of each wrench 110 can be switched during a cycle of tightening or loosening a bolt 32 . In one embodiment the switch from high to low or low to high torque options can be based on height. In one embodiment the height can be measured using a height sensor 1350 for elevator 1200 which height sensor can be commercially available. In one embodiment the height sensor 1350 can be a linear variable detection transducer.
In one embodiment the high and low torque portions of each wrench 110 can be switched as many times as needed when tightening or loosening a bolt 32 . The operations of each will be described below.
In one embodiment the high and low torque portions of each wrench 110 can be simultaneously energized. During requirements of low torque, the high speed portion 1200 takes over because it spins driver tip or socket 1010 faster than the low speed/high torque 590 portion. In this case drive gear 600 merely spins faster than low speed/high torque 590 portion attempts to turn drive gear 600 (by pawl 900 performing a ratcheting motion against biasing members 920 as drive gear 600 turns faster than piston 740 and pawl 900 attempt top turn drive gear 600 ). During requirements of high torque, the motor 1210 from the high speed portion 1200 “stalls” and the high torque 590 takes over (albeit at a slower rotational speed). In this manner each wrench 110 can transition between high and low torque modes as frequently and as many times as needed during either tightening (making up) or loosening (breaking out) a bolt 32 .
Torque wrench 110 can comprise a driver 1000 with tip or socket 1010 configured to engage a threaded connector 32 such as a bolt or nut. Socket head 1010 also comprises a plurality of faces or socket teeth radially positioned. Hydraulic wrench assembly 110 further comprises a hydraulic cylinder 700 . Hydraulic cylinder 700 is configured to extend and retract a drive pawl 900 which is positioned to engage ratchet teeth 610 upon extension of pawl 900 . When pawl 900 engages ratchet teeth 610 , driver 1000 , driver tip or socket 1010 , and threaded connector 32 are rotated upon further extension of pawl 900 , which will either tighten or loosen threaded connector 32 depending upon the direction of rotation of driver 1000 . Pawl 900 may retracted and extended again, further rotating driver 1000 and driver tip or socket 1010 , and threaded connector 32 until the desired torque is reached or until threaded connector 32 is adequately loosened.
Torque wrench 110 further comprises a high speed/low torque driver 1200 which can include a hydraulic motor 1210 which is mechanically coupled to driver 1000 (such as through a belt, toothed belt, or chain connection) so that operation of high speed driver 1200 will result in driver 1000 along with driver tip or socket 1010 , and threaded connector 32 being rotated at a relatively high rotational speed. Typically, high speed/low torque driver 1200 will rotate at about 100 rpm and will be configured to provide about 500 ft lbs of torque to threaded connector 32 . Driver 1200 can be used until threaded connector is snug, a condition that will be apparent when motor 1210 stalls, and driver 1000 stops turning.
In one embodiment high Speed/low torque driver 1200 will stop turning when the reaction force or torque from tightened bolt 32 equals the torque placed by driver 1200 (e.g., piston 740 , piston rod 750 , drive plates 800 , 810 , and pawl 900 on drive gear 600 ). This state can be called “stalled” or “being torqued out.” Hydraulic motor 1210 stalls out and acts as blockage in the hydraulic line feeding it. As the pressure builds up, the pressurized fluid causes hydraulic motor 1210 to rotate which allows the fluid to pass and prevents the pressure from building up further. However, if resistance from threaded connector 32 prevents motor 1210 from rotating, the pressure will continue to increase until either that obstacle is overcome and motor 1210 rotates allowing some of the fluid to pass or until relief is obtained elsewhere (such as by the high torque portion 590 taking over). As bolt 32 gets tighter, it will provide more and more resistance to rotation of motor 1210 . As threaded connector 32 gets tighter and tighter, the pressure in the hydraulic line will be increased ever higher.
In one embodiment both the high speed/low torque 1200 and low speed/high torque driver 590 portions are continuously hydraulically energized. During “low torque” phases of turning bolt 32 the high speed motor 1210 will “stall” and the high torque driver 590 will continue to turn bolt 32 either until bolt 32 is made up to an acceptable torque or the torque on bolt 32 drops and the high speed motor 1210 will again take over. In one embodiment when the back pressure from motor 1210 reaches a stalled condition operation is switched to low speed/high torque wrench 410 .
Reaction Torque
During both high speed and high torque phases reaction bar 500 will provide the reaction force to counteract the reaction torque generated by either tightening or loosening bolt 32 . During operation a reaction torque (or force) equivalent to the torque applied by torque wrench 110 will be generated when removing or tightening bolt 32 . This reaction torque must be compensated for, such as by having reaction bar 500 transmit such torque to the structure of the rig 20 and/or riser 40 .
In one embodiment the reaction torque from bolt 32 is transferred to driver 1000 and wrench body 406 to reaction bar 500 , and from reaction bar 500 to braces 160 and 170 , to feet 155 and 157 , to shafts 352 and 354 , and to base 300 . In one embodiment base 300 is connected to spider 50 which itself can be connected to the floor of rig 10 (even if by friction) and such reaction torque is transferred to the floor of rig 10 .
In one embodiment bases 300 A-F are interconnected (but sitting on the floor of rig 10 without being bolted down), and the reaction torque is ultimately transferred from each of the bolts 32 A-F to one or more of the other bolts 32 A-F, and to the upper and/or lower riser sections 42 and 46 through the flanges 43 and 47 .
Control Units
In one embodiment a single control unit 80 is used for torque modules 110 A-F. In one embodiment a control unit is used to control multiple wrenches (e.g., 2, 3, 4, 5 and/or 6). In one embodiment each wrench (e.g., 110 A-F) has its own control unit.
General Sequence Steps
FIGS. 3 through 10 show various sequence steps in a make up process for one of the torque stations.
FIGS. 11 through 22 show various sequence steps in a break out process for one of the torque stations.
Each process will be described below for one embodiment.
Make-Up Sequence
FIGS. 3 through 10 show various sequence steps in a make up process for one of the torque stations. Only one of the torque stations 110 is shown as all six follow substantially the same process—although each station 110 can act independently of the other stations for the described steps unless specified otherwise.
FIG. 3 is a top view showing one embodiment of the torque wrench system during make up with all six of the torque stations ( 110 A-F) in horizontally retracted states (and station 110 A in a partially broken out view).
FIG. 4 is a top view showing one embodiment of the torque wrench system during make up with all six of the torque stations ( 110 A-F) in horizontally extended states (and station 110 A in a partially broken out view).
FIG. 5A is a schematic side view one of the torque stations 110 ready for the beginning of a make up or break out sequence as the driver socket is completely retracted horizontally (arrow 61 ) and moved to its highest vertical position (arrow 64 ) which will clear a bolt 32 previously placed in a storage condition for a riser joint 42 along with being below the lowest point of the insulation or floatation (schematically indicated by numerals 44 ) for the upper riser section or joint 42 . FIG. 5B is a top view of the torque station of FIG. 5A shown in partially broken out view.
FIG. 6A is a schematic side view of torque station 110 where drive socket 1010 has moved horizontally (arrow 60 ) over a bolt 32 and is rotating for tightening (arrow 66 ), the drive socket or tip 1010 is also moving downwardly (arrow 63 ), and is about to engage the head of bolt 32 . FIG. 6B is a top view of the torque station 110 shown in partially broken out view.
FIG. 7A is a schematic side view of torque station 110 where drive socket or tip 1010 has engaged the bolt 32 and begun to spin down the bolt 32 through the upper flange 47 and into the gap 49 . FIG. 7B is a top view of the torque station 110 shown in partially broken out view.
FIG. 8A is a schematic side view of the torque station 1105 after the drive socket 1010 has spun down the bolt 32 , and the bolt 32 is now allowed a free fall through the gap between the flanges 43 and 47 , and the head of the bolt 32 has vertically dropped in relation to the drive socket 1010 . Free fall occurs and bolt 32 drops a distance such as 1 inch but its head remains in socket 1020 of tip 1010 because of excess capacity depth 1030 . FIG. 8B is a top view of the torque station 110 shown in partially broken out view.
FIG. 9A is a schematic side view of the torque station 1105 after the drive socket 1010 has spun down the bolt 32 , allowed a free fall of the bolt 32 through the gap 49 between the flanges 43 and 47 , and further spun down the bolt 32 to the lower flange 47 by about two threads in the lower flange 47 . FIG. 9B is a top view of the torque station 110 shown in partially broken out view.
FIG. 10A is a schematic side view of the torque station 110 after the drive socket 1010 has spun down the bolt 32 until shoulder to shoulder contact between the upper flange 43 and the bolt head has occurred, and the torque station 110 goes into a high torque mode where the piston 740 and cylinder 700 control rotation of the driver 1000 . After the desired make up torque is achieved the driver tip 1010 will be moved upward and retracted (arrows 64 and 61 ) to the position shown in FIG. 5 and be ready for the next make up cycle.
Now the general method for one embodiment will be described for the make up mode.
In the beginning all six modules ( 110 A-F) are in the fully retracted position (which can be called the home position). Previous to module 110 extension, there can be a safety check to make sure that all six modules ( 110 A-F) are in the home position before a make-up routine can be started. The home position can be both a vertical home position (arrow 64 —which can be checked by the vertical height sensor 1350 ) along with a horizontal radially retracted home position (arrow 60 —which can be checked by a timing sequence using the body slide cylinders 362 and 364 , such as retraction hydraulic pressure for a set period of time which can be 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 seconds of retraction pressure). Fully retracted positions can be controlled by fully retracted body slide cylinders 362 and 364 , or by a retraction catch (e.g., rear plate 358 ), or a combination of the two. In one embodiment there can be an adjustable body retraction stop (e.g., rear plate 358 ) for each body module ( 110 A-F) in the retraction step.
Pressing the start button (e.g., located on control panel 80 ) for make up causes all six modules ( 110 A-F) to be radially extended in the directions of arrow 61 (by the body slide cylinders 362 and 364 extending) and causing the modules ( 110 A-F) to radially extend (arrows 61 A-F) such that the individual drive sockets ( 1010 A-F) will be positioned over the individual bolts ( 32 A-F). Radial extension of modules ( 110 A-F) occurs on both a timing control along with a radial extension stop (e.g., extension adjusters 357 on front plate 356 ). In one embodiment there can be an adjustable body extension stop 357 for each body module 140 in the extension step. In one embodiment radial extension (in the direction of arrow 61 ) can be checked by a timing sequence using the body slide cylinders ( 362 and 364 ), such as extension hydraulic pressure for a set period of time which can be 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 seconds of extension pressure.
In one embodiment, after a set period of time following the release of hydraulic pressure to each of the body slide cylinders ( 362 and 364 ), each of the drive socket 1010 is lowered (in the direction of arrow 63 ). In one embodiment the set period of time can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment, at the beginning of the lowering step ( FIG. 6A ), each drive socket 1010 can be rotated (in the direction of arrow 66 ) using the high speed/low torque driver 1200 at a first rotational speed (which is lower than a second rotational speed). In various embodiments the relative rotational speeds can be 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 percent of each other. In various embodiments the relative rotational speeds can be within a range of between any two of the above specified percentages.
In one embodiment the first rotational speed (in the direction of arrow 66 ) of each individual drive socket ( 1010 A-F) is continued until a set height (H 2 shown in FIG. 9A ) of the individual drive socket head is reached. In one embodiment the switch from first to second vertical speeds (in the direction of arrow 63 ) corresponds with the bolt 32 dropping between the threaded sections of the two riser flanges (gap 49 ) and entering the threaded section of the lower riser flange 47 . In one embodiment this set height of the drive socket 1010 is based on the riser bolt 32 being threadably engaged with the threads of the lower riser flange joint 47 . In one embodiment this height is based on an engagement of at least 2 threads. In one embodiment each of the six modules 110 are individually controlled based on the height H of the individual drive sockets 1010 .
In one embodiment the rate of vertical movement (in the direction of arrow 63 ) of each drive socket ( 1010 A-F) has a first vertical speed and a second vertical speed during vertical drop (in the direction of arrow 63 ) of each drive socket ( 1010 A-F). In one embodiment the first vertical speed can be lower than a second vertical speed). In various embodiments the relative vertical speeds can be 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 percent of each other. In various embodiments the relative vertical speeds can be within a range of between any two of the above specified percentages. In one embodiment the switch from the first vertical speed to the second vertical speed can be simultaneous with the switch from the first rotational speed to the second rotational speed.
In one embodiment each of the drive sockets ( 1010 A-F) are checked to determine that a lower specified vertical height (H 3 shown in FIG. 10A ) has been achieved before a high torque mode is entered with each of the drive sockets ( 1010 A-F). In one embodiment a set period of time is waited from the last drive socket reaching its specified ending vertical height (H 3 ) before high toque mode is entered. In one embodiment the set period of time can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment each of the drive sockets ( 1010 A-F) respectively spin down its riser bolt ( 32 A-F) until a snug condition is achieved between the riser bolt and the joint before a high torque mode is simultaneously entered with each of the drive sockets ( 1010 A-F). In one embodiment a snug connection between the riser bolt and the joint is less than about 600, 500, 400, 300, 200, 100, 50, 25, and 0 foot pounds of torque between the riser bolt and the joint connection. In various embodiments each of the riser bolts is within the same range of between about any two of the above specified torques. In one embodiment a set period of time is waited from the last bolt reaching its snuggling torque before high toque mode is entered. In one embodiment the set period of time can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment each of the drive sockets ( 1010 A-F) are started in the high torque mode simultaneously. In one embodiment each of the drive sockets ( 1010 A-F) are continued in the high torque mode until a pre-set back pressure is achieved (and the high torque mode hydraulically stalls). In one embodiment the set period of time can be 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 seconds of extension pressure. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment the final make-up torque between each of the riser bolts ( 32 A-F) for a particular riser joint are within less than about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, ½ percent of each other's make-up torques. In various embodiments the final make-up torques can be within a range of between about any two of the above specified percentages.
In one embodiment a set period of time is specified for each of the drive cylinders ( 700 A-F) of the drive sockets ( 1010 A-F) to reach the preset torquing pressure, and if not met a warning signal is sent out. In one embodiment along with the warning sign the system is shut down for diagnostic checking.
In one embodiment where each of the drive sockets ( 1010 A-F) reach and maintain the pre-set back pressure each of the drive sockets ( 1010 A-F) are then sent back to the home position (retracted vertically in the direction of arrow 64 and horizontally in the direction of arrow 60 ). In one embodiment the retracted vertical mode is achieved before the start of retraction in a horizontal mode. In one embodiment the drive socket 1010 is not spun either in high speed or in high torque during retraction. In one embodiment retraction vertically is checked by a vertical height sensor 1350 . In one embodiment retraction horizontally (in the direction of arrow 60 ) is by a pre-set time period. The horizontal radially retracted home position can be checked by a timing sequence using the body slide cylinders 362 and 364 , such as retraction hydraulic pressure for a set period of time which can be 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 seconds of retraction pressure. In various embodiments the set period of time can be within a range of between any two of the above set periods of time. Fully retracted positions can be controlled by fully retracted body slide cylinders 362 and 364 , or by a retraction catch (rear plate 358 ), or a combination of the two. In one embodiment there can be an adjustable body retraction stop (e.g., adjustable fasteners in rear plate 358 ) for each body module ( 110 A-F) in the retraction step.
In one embodiment the made up riser flange ( 43 and 47 ) is lowered, and a new section of riser 42 ′ is placed on the riser (on top of riser section 42 ) for make-up. In one embodiment the above specified steps are repeated for attaching the new section of riser ( 42 ′ being attached to 42 ).
In one embodiment the above specified steps are repeated until the length of riser 40 spans from the sea floor (well head or blow out preventer) to the rig or platform.
Break-Out Sequence
To place torque module 110 in the breakout mode (i.e., to loosen bolt 32 ) compared to the make up mode, wrench 400 will have to be flipped over so that bottom 420 is now above top 410 . This can be accomplished relatively easily by removal of brace 160 , and sliding upward in the direction of arrow 64 wrench 400 . Bores 460 , 470 will allow wrench 400 to slide over driver shaft of driver 1000 . Bore 490 will allow wrench 400 slide over screw 1330 . Bore 498 will allow wrench 400 to slide over reaction shaft or bar 500 . High speed/low torque driver 1200 can maintain its position. Once flipped over (i.e., bottom 420 being above top 410 ), wrench 400 can again be placed on high speed/low torque driver 1200 with bores 460 , 470 again going over shaft of driver 1000 , bore 490 over screw 1330 , and bore 498 over reaction shaft or bar 500 . Brace 160 is again placed over reaction bar or shaft 500 .
FIGS. 11 through 22 show various sequence steps in a break out process for one of the torque stations 110 . Only one of the torque stations 110 is shown as all six follow substantially the same process—although each station 110 can act independently of the other stations for the described steps unless specified otherwise.
FIG. 11 is a top view showing one embodiment of the torque wrench system during break out with all six of the torque stations ( 110 A-F) in horizontally retracted states (and station 110 A in a partially broken out view showing various individual components). FIG. 12 is a top view showing one embodiment of the torque wrench system during break out with all six of the torque stations ( 110 A-F) in horizontally extended states (and station 110 A in a partially broken out view).
FIG. 13 is a schematic side view one of the torque stations 110 ready for the beginning of a break out sequence as the driver socket 110 is completely retracted horizontally and moved to its highest vertical position (arrow 64 ) which will clear the particular bolt 32 being broken out along with being below the lowest point of the insulation or floatation for the upper riser section or joint (schematically shown by lines 44 ). This position can be called the home position.
FIG. 14 is a schematic side view one of the torque stations 110 moving (schematically indicated by arrows 63 and 60 ) to a locating position for the drive socket 1010 on the bolt 32 head and showing drive socket 1010 after being partially radially extended (in the direction of arrow 60 ) to now move within a projected cylinder of the insulation 44 (schematically shown by dashed line 44 ′), and also moved vertically down (in the direction of arrow 63 ) to height H 1 before being positioned above the head of its respective bolt 32 to be broken out. At height H 1 , drive socket 1010 can begin to be rotated at a first speed in the direction of arrow 68 . In one embodiment height H 1 will be about ½ inch above the top of the head of bolt 32 . Also at H 1 , the downward speed of drive socket 1010 can be reduced (such as to 1, 2, 3, 4, 5, 6, 7, 8, 9 and/or 10 inches per minute) during the time it is being located on bolt 32 .
FIG. 15 is a schematic side view of the torque station 110 illustrating the step of locating (and engaging) the drive socket 1010 on the bolt 32 head for break out. As will be described below both low torque rotation using motor 1210 (schematically indicated by arrow 68 ) along with locating high torque stroking (schematically indicated by arrows 772 an 774 ) can be used during the locating step for drive socket 1010 before beginning the high torque break out step. As will be described below location of drive socket 1010 on bolt 32 can be determined when drive socket 1010 drops (in the direction of arrow 63 ) from height H 2 ( FIG. 15 ) to height H 3 ( FIG. 16 ).
FIG. 16 is a schematic side view one of the torque stations 110 where the drive socket 1010 is located on bolt 32 , bolt 32 has shoulder to shoulder contact with the upper flange 43 , and the drive tip or socket 1010 is beginning the breakout process in high torque mode (arrows 772 and 774 ) so that the torque station 110 will go into the high torque mode with the drive gear 600 .
FIG. 17 is a schematic side view of torque station 110 where the drive tip or socket 1010 has partially broken out the bolt 32 , spun out the bolt (arrow 68 ) to where a free spinning mode has been entered because the threads of the bolt 32 are in gap 49 —between the threads in the upper 43 and lower 47 flanges. In this figure arrow 68 schematically indicates the spinning out of bolt 32 .
FIG. 18 is a schematic side view of torque station 110 where lifting fork 1400 has engaged the freely spinning bolt 32 (arrow 1402 ) and begun lifting (arrow 64 ) the bolt 32 so that its threads can engage the threaded portion of upper flange 43 . In this figure arrow 68 schematically indicates the free spinning of bolt 32 .
FIG. 19 is a schematic side view of torque station 110 where lifting fork 1400 has lifted (arrow 64 ) the bolt 32 enough to now engage the threaded portion of the upper flange 43 , and the lifting fork can later retract. In this figure arrow 68 schematically indicates the spinning out of bolt 32 .
FIG. 20 is a schematic side view of torque station 110 where lifting fork 1400 has retracted (arrow 1404 ) and the bolt 32 has been additionally spun up (arrow 64 ) compared to its position in FIG. 19 , and is now located in the bolt's vertical position for retrieval of the section riser 42 (H s or Hstorage). In this figure arrow 68 schematically indicates the final spinning out of bolt 32 to its storage position in flange 43 .
FIG. 21 is a schematic side view of the torque station 110 where the drive socket 1010 has stopped rotating and has been vertically (arrow 64 ) raised above the head of the bolt 32 (H cl or Hclearance). At this point the threaded portion of bolt 32 can be protected by flange 32 during storage. Also at this point there still is clearance under the floatation or insulation of the riser joint or section 42 .
FIG. 22 is a schematic side view of torque station 110 where the drive tip or socket 1010 is completely retracted horizontally (arrow 61 ) and ready for the start of the next break out cycle.
In one embodiment ( FIGS. 9 and 16 ) the height H to the driving tip or socket 1010 is positioned above the maximum height of the tightened head of bolt 32 to be loosened. Vertical positioning of driving tip or socket 1010 can be accomplished by using vertical lifting and lowering mechanism 1300 . Horizontal positioning of driving tip or socket 1010 can be accomplished using adjustable sliding housing 140 . In one embodiment both vertical and horizontal movement is accomplished simultaneously to reduce the amount of time before loosening can be started (and reduce the overall cycling time).
Risers 40 are made up of a plurality of riser sections 42 , 46 , etc) and typically come in standard sizes and specifications so that bolts 32 in a tightened condition will be at a known maximum height. Additionally, the maximum height of bolt 32 when loosened can be calculated. Accordingly, the minimum height H ( FIG. 16 ) for driving tip or socket 1010 can be calculated relatively easily before loosening can begin. Additionally, the maximum height of the top of wrench 400 at the end of the loosening cycle should be below the bottom of the insulation or floatation 44 found on the riser 40 section being broken (otherwise the wrench 400 or torque station 110 could damage the insulation or floatation 44 ). The distance between the insulation or floatation 44 and the riser flange (e.g., flange 43 of upper riser section 42 shown in FIG. 9 ) typically is made to a specified distance and the maximum height can be easily determined. Although not shown in the drawings, in one embodiment a physical vertical limit is placed on the maximum height of high torque driver 590 to make sure that driver (or body 406 of wrench 400 ) does not rise above a specified level. In one embodiment this physical limit is a limiting brace on sliding housing 140 .
Now the general method will be described for one embodiment in break out mode.
In the beginning all six modules ( 110 A-F) are in the fully retracted position (horizontally in the direction of arrow 61 and vertically in the direction of arrow 64 —which can be called the home position). Previous to body 140 extension, there can be a safety check to make sure that all six modules ( 110 A-F) are in the home position before a make-up routine can be started. The home position can be both a module vertical home position (in the direction of arrow 64 —which can be checked by the vertical height sensor 1350 ) along with a horizontal radially retracted home position (in the direction of arrow 60 —which can be checked by a timing sequence using the body slide cylinders 362 and 364 , such as retraction hydraulic pressure for a set period of time which can be 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 seconds of retraction pressure). Fully retracted positions can be controlled by fully retracted body slide cylinders 362 and 364 , or by a retraction catch (e.g., rear plate 358 ), or a combination of the two. In one embodiment there can be an adjustable body retraction stop (e.g., limiter 359 ) for each body module ( 110 A-F) in the retraction step.
Pressing the start button (e.g., located on control panel 80 ) for break-out causes all six modules ( 110 A-F) to be radially extended (in the direction of arrow 60 by the body slide cylinders 362 and 364 extending) and causing the modules ( 110 A-F) to radially extend (arrows 60 A-F) such that the individual drive sockets ( 1010 A-F) will be positioned over the individual bolts ( 32 A-F). Radial extension of modules ( 110 A-F) occurs on both a timing along with a radial extension stop (e.g., extension adjusters 357 on front plate 356 ). In one embodiment there can be an adjustable body extension stop ( 357 A-F) for each body module ( 140 A-F) in the extension step. In one embodiment radial extension (in the directions of arrows 60 A-F) can be checked by a timing sequence using the body slide cylinders ( 362 A-F and 364 A-F), such as extension hydraulic pressure for a set period of time which can be 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 seconds of extension pressure.
In one embodiment, during horizontal extension (in the directions of arrows 60 A-F) of each of the body slide cylinders ( 362 A-F and 364 A-F), each of the drive sockets ( 1010 A-F) can be lowered (in the direction of arrow 63 ). In one embodiment rotation of the drive sockets ( 1010 A-F) at a first rotational speed (in the direction of arrow 68 ) begins when the individual drive socket ( 1010 A-F) reaches a first vertical height (H 1 ). In one embodiment, the first rotational speed can be lower than a second rotational speed during actual spin out of bolts ( 32 A-F). In various embodiments the relative rotational speeds can be 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 percent of each other. In various embodiments the relative rotational speeds can be within a range of between any two of the above specified percentages. In one embodiment at the time of beginning rotation of the drive socket ( 1010 A-F) the horizontal body slide cylinders ( 362 A-F and 364 A-F) are hydraulically relaxed.
In one embodiment each drive socket 1010 is rotated at the first rotational speed (in the direction of arrow 68 ) until the drive socket 1010 reaches a second vertical height (H 2 as shown in FIG. 15 ) at which time the high speed low torque motor 1200 is stopped and hydraulically relaxed. In one embodiment the second vertical height H 2 is such that drive socket 1010 is about 1½, 1, or ½ inches over the bolt 32 head. At this same time vertical movement (in the direction of arrow 63 ) of the drive socket 1010 is stopped and the hydraulic motor 1310 driving the vertical positioning screw 1330 is hydraulically relaxed for a set period of time. In one embodiment the set period of time can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment, after the set period of time, the vertical positioning screw 1300 attempts to move the drive socket 1010 to a third vertical height H 3 and holds the drive socket 1010 at this height H 3 . In one embodiment H 3 is about 1½, 1, or ½ inches in the direction of arrow 63 compared to H 2 .
In one embodiment if the third vertical height H 3 of drive socket 1010 is not achieved within a set period of time at a particular torquing station, at least one locating high torque stroke (schematically indicated by arrows 772 and 774 in FIG. 15 ) is made on the drive socket 1010 to assist in locating the drive socket 1010 on the bolt 32 head and a further check on the vertical height of the drive socket 1010 is made to determine engagement of the bolt 32 head by the drive socket 1010 . In one embodiment the vertical positioning screw 1300 continues to attempt to pull down (in the direction of arrow 63 ) the drive socket 1010 while the locating high torque stroke is made. In one embodiment the set period of time can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment after the first iteration of the locating drive stroke is made and the locating high torque stroke is not achieved for the drive socket 1010 , a second iteration of locating drive stoke is made and the vertical height (H) of the drive socket 1010 is checked to determine if the drive socket has dropped to height H 3 (and been properly located on the bolt 32 head). In various embodiment multiple iterations of locating high torque strokes can be made along with checks of the vertical heights of the drive socket 1010 , until engagement of the bolt 32 head is determined. In one embodiment the vertical positioning screw 1300 continues to attempt to pull down the drive socket 1010 while the locating high torque stroke is made. In various embodiments, before each locating high torque stroke is made, vertical movement of the drive socket 1010 is stopped. In one embodiment the vertical control system is also relaxed before each locating high torque stroke is made. In various embodiments, before each locating high torque stroke is made, rotation of the drive socket 1010 is stopped. In one embodiment the high speed rotational motor 1310 is also relaxed before each locating high torque stroke is made. In various embodiments, before each locating high torque stroke is made, the radial positioning system ( 362 and 364 ) for the drive socket 1010 is also relaxed. In one embodiment, a warning signal is sent if one or more torquing stations are not able to be located on their respective bolt head within a set period of time (i.e., step “d”), or within a set number of high torque locating strokes.
In one embodiment at the time the vertical positioning screw 1300 is stopped, the drive socket 1010 enters a high torque break-out mode (using high torque driver 590 ) and schematically indicated in FIG. 16 . In one embodiment the high torque mode is cycled (strokes of wrench 400 ) for a set number of stroking cycles. In one embodiment the set number of cycles can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, and 50. In various embodiments the set number of cycles can be within a range of between any two of the above set number of cycles. In one embodiment after its last cycle, the high torque system (piston 740 and rod 750 ) fully retracts. In one embodiment full retraction is determined by a timing sequence using the high torque hydraulic cylinder, such as extension hydraulic pressure for a set period of time which can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment each of the drive sockets ( 1010 A-F) are started in the high torque mode simultaneously. In this embodiment proper location of each of the six drive sockets is made ( FIGS. 15 to 16 ) before the high torque break out mode for any one of the drive sockets is started.
In one embodiment the high torque mode is switched to low torque mode after a specified lower back pressure is achieved on the high torque system 590 . In one embodiment a check can be made on the low torque high speed system 1200 to see if it stalls when breaking out the bolt 32 . In one embodiment the stalling condition is determined based on reaching a specified back pressure for the motor 1210 . In one embodiment the stalling condition is determined upon falling below a specified flow rate through the motor 1210 .
In one embodiment during the high torque breakout mode the drive socket 1010 is not moved vertically upward (in the direction of arrow 64 ) by vertical screw 1330 . Instead, in this embodiment vertical movement (in the direction of arrow 64 ) of the drive socket 1010 is taken up by a vertical angular turning (in the direction of arrow 70 ) of the torque wrench body 590 . In one embodiment this differential vertical angular turning of the torque wrench body 590 is relieved when the bolt 32 leaves the threads of the lower flange 47 , and is located in the gap 49 between the upper 43 and lower 47 flanges, and is being raised by the lifting fork 1410 . In one embodiment the arms of the lifting fork 1410 are located a set distance below the tip of the drive socket ( 1010 A-F). In one embodiment the set distance is about ¼, ⅜, ½, ⅝, ¾, ⅞, 1, 1¼, 1⅜, 1½, 1⅝, 1¾, 1⅞, 2 inches. In various embodiments the set distance can be about within a range of between any two of the above specified distances.
In one embodiment the switch from high torque to low torque modes for each of the modules ( 110 A-F) are done simultaneously. In one embodiment the switch is individually done for each of the modules.
In one embodiment the rate of vertical movement (in the direction of arrow 64 ) of each drive socket 1010 remains constant during vertical lifting (in the direction of arrow 64 ).
In one embodiment the rotational speed (in the direction of arrow 68 ) of the drive socket 1010 remains constant during vertical lifting (in the direction of arrow 64 ).
In one embodiment a set vertical height (H LF1 shown in FIG. 17 ) the lifting fork 1410 is extended (in the direction of arrow 1402 ). In one embodiment full extension of the lifting fork 1410 is determined by a timing sequence using the lifting fork hydraulic cylinder(s) 1440 , such as extension hydraulic pressure for a set period of time which can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment the lifting fork 1410 remains extended until the drive socket 1010 A-F) reaches a second vertical height in the direction of arrow 64 (H LF2 shown in FIG. 18 ) at which height the lifting fork 1410 is retracted (in the direction of arrow 1404 ). In one embodiment full retraction of the lifting fork 1410 is determined by a timing sequence using the lifting fork hydraulic cylinder(s) 1440 , such as by retraction hydraulic pressure for a set period of time which can be ½, ¾, 1, 1½, 2, 3, 4, and 5 seconds. In various embodiments the set period of time can be within a range of between any two of the above set periods of time.
In one embodiment rotation of the drive socket 1010 in the direction of arrow 68 is stopped simultaneously with the start of retraction (in the direction of arrow 1404 ) of the lifting fork 1410 .
In one embodiment after start of retraction (in the direction of arrow 1404 ) of the lifting fork 1410 , the drive socket 1010 is sent to a home position for retracted vertical (in the direction of arrow 64 ) and retracted horizontal (in the direction of arrow 61 ) positioning.
In one embodiment the retraction in a vertical mode (raising drive socket 1010 in the direction of arrow 64 ) is achieved before the start of retraction in a horizontal mode (in the direction of arrow 61 ). In one embodiment the drive socket 1010 is not spun either in high speed or in high torque during retraction. In one embodiment retraction vertically (in the direction of arrow 64 ) is checked by a vertical height sensor 1350 . In one embodiment retraction horizontally (in the direction of arrow 61 ) is by a pre-set time period. The horizontal radially retracted home position can be checked by a timing sequence using the body slide cylinders ( 362 and 364 ), such as retraction hydraulic pressure for a set period of time which can be 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 seconds of retraction pressure. In various embodiments the set period of time can be within a range of between any two of the above set periods of time. Fully retracted positions can be controlled by fully retracted body slide cylinders, or by a retraction catch, or a combination of the two. In one embodiment there can be an adjustable body retraction stop 358 (e.g., adjustment screws 359 ) for each body module 140 in the retraction step.
In one embodiment the broken out riser joint 42 is removed, and the remaining riser string (lower riser joints 46 etc.) is raised until a new flange is revealed to be broken out. In one embodiment the above specified steps are repeated for newly revealed flange connection between two riser joint sections.
In one embodiment the above specified steps are repeated until the length of riser has been removed.
Tightening or Make Up Sequence
Various additional embodiments are described below for the make up mode.
In one embodiment ( FIGS. 5 and 6 ) the height H to the driving tip or socket 1010 is such that it is positioned above (giving a clearance Hcl) the maximum height of the non-tightened head of bolt 32 which will be tightened by wrench 110 .
Vertical positioning of driving tip or socket 1010 can be accomplished by using vertical lifting and lowering mechanism 1300 which includes elevator 1200 . Horizontal positioning of driving tip or socket 1010 can be accomplished using adjustable sliding housing 140 and control cylinders 362 and 364 .
Risers 40 are made up of a plurality of riser sections 42 , 46 , etc., and typically come in standard sizes and specifications so that bolts 32 in a non-tightened condition will be at a known maximum height. Accordingly, the minimum height H ( FIGS. 5 and 6 ) for driving tip or socket 1010 can be calculated relatively easily. Additionally, the maximum height of the top of wrench 400 should be below the bottom of the insulation found on the riser section being make up (otherwise the wrench 400 could damage the insulation). The distance between the insulation and the riser typically is made to a specified distance and the maximum height can be easily determined.
Driving tip or socket 1010 can be moved horizontally in the direction of arrow 60 until driving tip or socket 1010 is directly over the head of bolt 32 .
Vertical lifting and lowering mechanism 1300 (with elevator 1400 ) can begin to lower driving tip or socket 1010 downward in the direction of arrow 63 .
For tightening driving tip or socket 1010 is turned clockwise in the direction of arrow 66 .
Initially, turning in the direction of arrow 66 can be at a relatively slow speed until driving tip or socket 1010 engages the head of bolt 32 .
After engagement the speed of driving tip or socket 1010 can be increased using the high speed/low torque driver 1200 to initially tighten bolt 32 .
As bolt 32 is tightened it will move vertically downward (in the direction of arrow 63 ). To compensate for such downward movement, vertical lifting and lowering mechanism 1300 can also lower wrench 400 . The amount of lowering of wrench 400 (and drive tip or socket 1010 ) can be calculated based on the rotational speed with which bolt 32 is being turned by driver tip or socket 1010 . Because the pitch of bolt 32 will be known, the amount of vertical movement can be calculated once the rotational speed of bolt 32 is known. The rotational speed of bolt 32 can be approximated by the nominal rotational speed of the high speed/low torque driver 1200 (which this controls) or the low speed/high torque driver 590 (when this controls). In this manner engagement between driver tip or socket 1010 can be achieved during the entire tightening process. In one embodiment a height sensor 1350 can be used which tracks movement of elevator 1300 (and therefore drive tip or socket 1010 ).
In one embodiment motor 1310 can be set to rotate lifting screw 1330 such that lifting screw 1330 tends to move housing 1230 (and driver tip or socket 1010 ) more rapidly downwardly in the direction of arrow 63 than bolt 32 (being tightened by tip 1010 ) moves downwardly. In this embodiment, when bolt 32 does not drop as fast as lifting screw 1330 attempts to move downwardly housing 1230 of high speed/low torque driver 1200 , the head of bolt 32 will prevent tip 1010 (and housing 1230 ) from being moved downward in the direction of arrow 63 , and motor 1310 of vertical lifting and lowering mechanism will stall based on the resistance to screw 1330 trying to pull down housing 1230 when bolt 32 and tip 1010 is holding up housing 1230 —at least until bolt 32 is tightened enough (i.e., rotated by tip 1010 ) to allow tip 1010 and housing 1230 to also move downwardly in the direction of arrow 63 thereby freeing motor 1310 to again start turning screw 1330 and lowering housing 1230 and tip 1010 . It is anticipated that repetitive “cycles” of starting and stalling of motor 1310 during this torquing down sequence of bolt 32 will be seen.
In various commercially available riser constructions, the bolt 32 is not completely threaded from its tip to its head and there exists a non-threaded portion. With these non-completely threaded bolts and risers there will exist during a part of the tightening process where the entire threaded portion of bolt 32 is between the threaded portions of the threaded portions of upper and lower riser sections 42 and 46 . At this point the bolt 32 will freely drop an amount (approximately one inch) until it engages the threaded portion of the lower riser section 46 . To address this partial free fall, driver tip or socket 1010 can have an excess socket depth so that when bolt 32 experiences such free fall, the head of bolt 32 is still retained (albeit by an amount less than the free fall), but a sufficient amount so that proper engagement can be continued during the remainder of the tightening process. Immediately, after engagement of bolt 32 with the lower riser section 44 only a small amount of torque will be needed.
During the tightening of bolt 32 in the flange 47 of lower riser section 46 , the free fall distance of the bolt 32 could be made up by wrench 400 using vertical lifting and lowering mechanism 1300 lower driving tip or socket 1010 . This can be done either by having wrench 400 lowered at a faster rate then bolt 32 is being moved downward by tightening. Alternatively, a lowering step of wrench 400 could be used where mechanism 1300 lower wrench 400 a distance (e.g., the free fall distance of bolt 32 ) while driving tip or socket 1010 is not rotating (or rotating at a very slow speed).
Typically, even after bolt 32 engages the threaded portion of flange 47 of lower riser section 46 , the low torque portion of wrench 400 can continue to tighten bolt 32 (and the high torque portion will not be needed) until shoulder to shoulder contact is achieved between the head of bolt 32 and the flange 43 of the upper riser section 42 .
In one embodiment the wrench 400 switches to high torque based on the height of drive socket 1010 . In one embodiment, when ever a high torque portion is needed (e.g., the driving torque for bolt 32 exceeds the recommended torque for low torque driving portion), wrench 400 can transition from the low torque to the high torque driver. In one embodiment, wrench 400 can switch from low torque to high torque (and vice versa) as many times and as frequently as needed by bolt 32 . For example, there may be some debris in the threaded portion of flange 43 of upper riser section 42 which increases the amount of torque required to turn bolt 32 . If this occurs then wrench 400 can transition to the high torque portion and turn bolt 32 until the debris is cleared at which time the torque required to drive bolt 32 decreases and wrench 400 transitions back to the low torque driver such as until shoulder to should contact between bolt 32 and riser section is achieved when again wrench 400 transitions to the high torque portion to complete the tightening process.
Driving tip or socket 1010 can be continued to be turned in the direction of arrow 66 (moving bolt 32 in the direction of arrow 63 ) until a specified height is achieved of drive tip 1010 (such height approximating shoulder-to-shoulder contact between the head of bolt 32 and the flange 43 of the upper riser section 42 ). After this point a higher torque is expected to be required in making up bolt 32 and the high torque/low speed portion of wrench 400 can take over rotating driver tip or socket 1010 in the direction of arrow 66 thereby torquing down bolt 32 until the desired torque is achieved.
After the desired “make up” torque on bolt 32 is achieved driver tip or socket 1010 can be disengaged from bolt 32 where vertical lifting and lowering mechanism 1300 raises driver tip or socket 1010 (in the direction of arrow 64 ) and driver tip or socket 1010 is also moved horizontally in the direction of arrow 61 so that none of the components of wrench 400 will fall within a hypothetical cylinder extending from the outside of the flanges 43 , 47 of upper and lower riser sections 42 and 46 . To decrease cycling time driver tip or socket 1010 can be moved horizontally in the direction of arrow 61 shortly after it clears the head of bolt 32 (compared to raising wrench 400 to its maximum height before horizontal movement in the direction of arrow 61 is started).
After adequate clearance between riser 40 and wrench 110 is achieved (such as when torque modules 110 A-F have been completely retracted), the riser sections are lowered so that a new riser section is placed on previously upper riser section 46 (and now riser section 46 becomes the new lower riser section and the newly placed riser section becomes the new upper riser section), and the making up process begins again using the above referenced steps.
It is expected that the entire cycle time from first starting the torque wrench 110 in the direction of arrow 60 , tightening bolts 32 , and moving torque wrench out of the way and ready for the next tightening cycle will be less than three minutes. In various embodiments the entire cycle time from the start of a tightening sequence for all six bolts on a single flange level to completion of tightening sequence on the flange level is less than about 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, and/or 360 seconds. In various embodiments a range between about any to of the above referenced times can be used. In various embodiments these timing limits can be maintained for greater than 5, 10, 15, 20, 30, 40, 50, 60, and more flange levels in installing or tripping in the riser string.
Loosening or Break Out Sequence
Various additional embodiments are described below for the break out mode.
Driving tip or socket 1010 can be moved horizontally in the direction of arrow 60 until driving tip or socket 1010 is directly over the head of bolt 32 .
Driving tip or socket 1010 can be turned in the direction of arrow 68 (i.e., counter-clockwise) for loosening. Vertical lifting and lowering mechanism 1300 can lower driving tip or socket 1010 downward in the direction of arrow 63 .
Initially, turning in the direction of arrow 68 can be at a relatively slow speed until driving tip or socket 1010 engages the head of bolt 32 . Typically, after engagement a high torque will be needed to break out shoulder to shoulder contact between the head of bolt 32 and the flange 43 of the upper riser section 42 .
In one embodiment the high torque/low speed portion of wrench 400 is prevented from operating until a desired minimum height of driving tip or socket head 1010 is achieved. This embodiment can resist stripping out of the head of bolt 32 . In this embodiment the driving tip or socket 1010 can be turned slowly at a low torque until the desired minimum depth of engagement between driving tip or socket 1010 and bolt 32 is achieved.
With adequate engagement between driving tip or socket 1010 and bolt 32 , the high torque/low speed portion of wrench 400 can be used to “break out” bolt 32 from its shoulder to shoulder engagement. Typically a high torque mode is required for this initial “break out” During the high torque mode wrench 400 rotates driving tip or socket 1010 in the direction of arrow 68 (moving bolt 32 in the direction of arrow 64 ) until shoulder-to-shoulder contact is relieved/removed between the head of bolt 32 and the flange 43 of the upper riser section 42 .
Shortly after breaking out the shoulder to shoulder contact, it is expected that a lower torque will be required to continue turning bolt 32 in the direction of arrow 68 , and the high speed/low torque driver 1200 can take over loosening of bolt 32 . Additionally, the high speed/low torque driver 1200 can turn bolt 32 rotationally faster compared to the high torque/low speed portion of wrench 400 .
As bolt 32 is loosened it will move vertically upward (in the direction of arrow 64 ). To compensate for such upward movement, vertical lifting and lowering mechanism 1300 can also raise wrench 400 . The amount of raising of wrench 400 (and driver tip or socket 1010 ) can be calculated based on the rotational speed with which bolt 32 is being turned by driver tip or socket 1010 . Because the pitch of bolt 32 will be known, the amount of vertical movement can be calculated once the rotational speed of bolt 32 is known. In this manner engagement between driver tip or socket 1010 and bolt 32 can be maintained during the entire loosening process.
In various commercially available riser constructions, the bolt 32 is not completely threaded from its tip to its head and there exists a non-threaded portion. With these non-completely threaded bolts and risers there will exist during a part of the loosening process where the entire threaded portion of bolt 32 is between the threaded portions of the threaded portions of upper and lower riser sections 42 and 46 . At this point the bolt 32 will “freely spin” and no longer rise. In one embodiment the “break out” portion is completed once the “free spin” condition is reached because bolt 32 no longer threadably connects upper and lower riser sections. However, if bolt 32 is left in the “free spin” state its threads can be damaged when riser section 42 is moved and relocated. Accordingly, it is preferred that bolt 32 is continued to be unloosed until it threads into upper riser section 42 so that the threads of bolt 32 will be protected. To address the “free spin” condition of bolt 32 , lifting fork 1400 can be used to lift bolt 32 until bolt 32 starts threading into the threaded portion of the upper riser section 42 . Lifting fork 1400 can move in the direction of arrow 1402 until fork 1400 engages the head of bolt 32 . Lifting fork 1400 and wrench 1400 can continue to be raised by vertical lifting and lowering mechanism 1200 until the threaded portion of bolt 32 begins to engage the threaded portion of the upper riser section 42 . To address this partial free spinning state of bolt 32 and re-engagement with the upper riser section, driver tip or socket can be slowed to avoid cross threading the upper riser section 42 . Immediately, after engagement of bolt 32 with the upper riser section 42 only a small amount of torque will be needed.
Driver tip or socket 1010 continues to loosen bolt 32 until a desired position for a “state of breakout” is obtained for bolt 32 . After the desired state of breakout is for bolt 32 is achieved driver tip or socket 1010 is disengaged from bolt 32 where vertical lifting and lowering mechanism 1300 raises driver tip or socket 1010 in the direction of arrow 64 and driver tip or socket 1010 is also retracted or moved horizontally in the direction of arrow 61 so that none of the components of wrench 400 will fall within a hypothetical cylinder extending from the outside of the flanges 43 , 47 of upper and lower riser sections 42 and 46 .
After clearance is achieved from the upper riser section 42 is removed and lower riser section raised so that a new riser section is seen connected to previously lower riser section 46 (and now riser section 46 becomes the new upper riser section and the newly raised riser section becomes the new lower riser section), and the breaking out process begins again using the above referenced steps.
It is expected that the entire cycle time from first starting the torque wrench 110 in the direction of arrow 60 , loosening bolt 32 , and moving torque wrench out of the way and ready for the next loosening cycle will be less than sixty seconds.
In one embodiment motor 1310 can be set to rotate lifting screw 1330 at a slower rate such that lifting screw 1330 tends to move housing 1230 (of high speed/low torque driver 1200 ) upwardly a little more slowly in the direction of arrow 64 than bolt 32 (being loosened by tip 1010 ) tends to move upwardly tip 1010 and housing 1230 . In this embodiment, when bolt 32 rises faster than lifting screw 1330 attempts to move up housing 1230 , the head of bolt 32 will push tip 1010 (and housing 1230 ) upward in the direction of arrow 64 , tending to cause screw 1330 to also rotate faster, turning and speeding up motor 1310 to catch up to the height of bolt 32 . In this embodiment it is anticipated that the threading of screw 1330 will not lock up with the interconnecting threading for housing 1230 .
In one embodiment motor screw 1330 can be turned at a rotational speed which will approximate the vertical lift of bolt 32 . If screw 1330 is actually turning faster and causing driver tip or socket 1010 to move upwardly (in the direction of arrow 64 ) faster than bolt 32 is moving, driver tip or socket 1010 has enough excess socket depth compared to the head of bolt 32 that driver tip socket 1010 will maintain adequate contact with the head of bolt 32 during the entire upward movement of bolt 32 . For example, the head of bolt 32 may have a nominal head depth of 3⅜ inches so that when driver tip or socket 1010 is fully placed on the head of bolt 32 3⅜ inches of head will be inside of driver tip or socket 1010 . If during the lifting cycle screw 1330 raises housing 1230 (and driver tip or socket 1010 ) an extra 1 or 2 inches compared to the height in which bolt 32 is raised, 2⅜ or 1⅜ inches of the head of bolt 32 will still remain in driver tip or socket 1010 .
It is expected that the entire cycle time from first starting the torque wrench 110 in the direction of arrow 60 , loosening bolt 32 , and moving torque wrench out of the way and ready for the next loosening cycle will be less than sixty seconds. In various embodiments the entire cycle time from the start of a loosening sequence for all six bolts on a single flange level to completion of loosening sequence on such flange level is less than about 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, and/or 360 seconds. In various embodiments a range between about any to of the above referenced times can be used. In various embodiments these timing limits can be maintained for greater than 5, 10, 15, 20, 30, 40, 50, 60, and more flange levels in retrieving tripping out the riser string.
Initial Engagement Between Driver and Head of Bolt
After driver or socket head 1010 has been placed directly over bolt 32 such that the centerline of rotation of driver or socket 1010 lines up with the center of rotation of bolt 32 , there may still be a non-alignment between the driving portions of driver or socket 1010 and the driven portions of the head of bolt 32 . There is a risk (albeit small) that rotating at such a high speed when initial contact between driver or socket 1010 and the head of bolt 32 will damage one or both if the driving surfaces of both are not properly aligned during first contact.
Accordingly, in one embodiment an alignment sequence can be used to facilitate initial engagement with driver or socket head 1010 and bolt 32 where the effective rotational speed of driver or socket 1010 is substantially reduced. Normal high speed rotational speed of high speed/low torque driver 1200 can exceed about 100 revolutions per minute, e.g., about 100, 105, 110, 115, 120, 125, 130, 135, 140, and 150 revolutions per minute. The alignment sequence can include high speed/low torque driver 1200 turning driver or socket 1010 at a relatively low speed until proper engage is achieved. This low alignment speed can be less than an average of 50, 45, 40, 35, 30, 35, 30, 25, 20, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2, and/or 1 revolution per minute.
The slower alignment speed with high speed/low torque driver 1200 can be achieved by controlling the speed of motor 1210 , such as by placing motor 1210 in a low speed phase.
Additionally, the slower alignment speed with high speed/low torque driver 1200 can be achieved by only intermittently supplying pressurized hydraulic fluid to motor 1210 (or supplying pressurized hydraulic fluid in spurts). Another option is to make motor 1210 a variable speed motor. Such an engagement mode can be maintained until a proper engagement between driver or socket 1010 with bolt 32 .
Proper engagement can be determined using a variety of means such as: (a) calculating a vertical movement of driver or socket head 1010 and/or measuring resistance to additional vertical dropping of driver or socket head 1010 when driver or socket head is restrained from additional dropping by the bolt head; (b) measuring backpressure in the hydraulic pressure of to motor 1210 ; and/or (c) measuring resistance to vertical dropping of driver or socket head 1010 (and connected wrench 400 ).
In one embodiment the effective vertical height of the head of bolt 32 is 3⅜ inches. In one embodiment a vertical drop of driver or socket 1010 a specified amount (e.g., 1, 1½, 2, 2½, 3, 3½, and/or 4 inches)(or 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, and 100 percent or the depth of the head of bolt 32 ) over the head of bolt 32 is determined to be effective engagement and high speed/low torque driver 1200 can increase to its normal high rotational speed mode.
In one embodiment changes in the back pressure to motor 1210 can be used to determined proper engagement. It is anticipated that resistance to the turning of driver or socket 1010 will vary before proper engagement (where the driving faces of both driver or socket 1010 and the driven faces of the head of bolt 32 ) meet compared to driver or socket merely spinning on top of the head of bolt 32 . This difference in back pressure can be used to determine proper engagement.
In one embodiment changes in backpressure to motor 1310 of vertical lifting and lowering mechanism can be used to determine proper engagement. If proper engagement is not obtained between driver or socket 1010 and bolt 32 (where the driving faces of both driver or socket 1010 and the driven faces of the head of bolt 32 ), bolt 32 will resist downward movement of wrench 400 and increase resistance to vertical lifting and lowering mechanism 1300 , which can cause motor 1310 to stall. This difference in back pressure can be used to determine proper engagement.
In one embodiment one or more (or all three) of the above means can be used to determine proper engagement.
In various embodiments the above referenced initial engage steps can be used in both the make up and break out sequences.
Schematic Diagrams for Components and Hydraulic Flow
FIGS. 45 through 47 include schematic diagrams of the hydraulic circuits controlling the high torque driver system 590 , low torque driver 1200 , vertical lifting and lowering mechanism 1300 , sliding system for sliding housing 140 (cylinders/pistons 362 and 364 ), and lifting fork mechanism 1400 .
FIGS. 45 (make up) and 46 (break out) show fluid flow and control for the low speed/high torque portion 590 . In one embodiment, automatic reciprocation of piston 740 (distinguished from manual reciprocation of prior art wrenches) is obtained. Basically, piston 740 can be automatically reciprocated between extended and retracted states inside (e.g., between first interior wall 712 and second interior wall 712 of hydraulic cylinder 700 ).
In one embodiment cylinder 700 can contain interior extension 713 and retraction 715 hydraulic ports. Cylinder 700 can have an interior chamber length L (between first 712 and second 714 interior walls), and piston 740 can have a width D corresponding to the interior chamber size of cylinder 700 . In one embodiment fluid source lines 713 and 715 can be located on side walls 712 and 714 . In other embodiments fluid source lines 713 and 715 can be spaced apart a desired length (such as between interior walls 712 and 714 ).
In the start of the extension/advance mode for piston 740 and rod 750 (i.e., movement in the direction of arrow 774 ) piston 740 can be located to the rear of cylinder 700 ( FIG. 34 ). Hydraulic fluid can flow into from port 713 causing piston 740 to move in the direction of arrow 774 . As piston 740 moves (in the direction of arrow 774 ) past port 722 , port 722 will see hydraulic pressure causing the flow direction mechanism schematically shown in the figures to switch flow from fluid source line 713 to fluid source line 715 causing the piston 740 and rode 750 to enter the retraction mode and move in the direction of arrow 772 .
The retraction mode can be controlled on a timing basis which can be flow through port 715 for a set period of time which can be 1, 2, 3, 4, 5, 6, 7, 8, 9, and/or 10 seconds of retraction pressure. In various embodiments the set period of time can be between any two of the specified periods of time.
During make up the above steps of entering the extension/advance mode and retraction mode continue until piston 740 stalls from reaching a specified back-pressure. This is preferably the backpressure which causes a desired torque on bolt 32 .
During break out the above steps of entering the extension/advance mode and retraction mode can continue for a specified number of strokes.
For extension in the high torque cylinder 700 , pressure is sent to the extension port 713 causing piston 740 to move in the direction of arrow 774 until pressure is read in the pilot port 722 (this will occur when the piston 740 passes up the pilot port 722 to see the hydraulic fluid inside the cylinder 710 ). Once the pilot port 722 sees pressure the system reverses hydraulic fluid flow to now send fluid through the retraction port 715 for a set period of time which can be 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 seconds of retraction pressure. Flow through retraction port 715 will cause piston 740 to move in the direction of arrow 772 .
On make-up this process (alternating stroking of piston 740 and rod 750 in the directions of arrows 774 and 772 ) is repeated until a pre-specified pressure is reached on the extension port with the pilot port having a reduced pressure (low to zero).
On break-out this process (alternating stroking of piston 740 and rod 750 in the directions of arrows 774 and 772 ) can be repeated for the set number of cycles.
Overall Side View in of Steps in Making Up (Tripping in) Multiple Sections of a Riser
FIGS. 48 through 57 schematically show various steps in making up individual joints of a riser 40 .
FIG. 48 is a schematic side view of the step of making up a riser 40 string of lowering (in the direction of arrow 63 ) a second riser section 45 onto a first riser section 46 where the first riser section 46 along with the rest of the riser 40 string is supported by the spider 50 .
FIG. 49 is a close up side view of where the second riser section 45 has been placed on top of the first riser section 46 showing a plurality of riser bolts 32 A-F ready to be tightened with the spider 50 supporting the riser 40 string and a plurality of torque modules 110 A-F are located in their home position.
FIG. 50 is a side view schematically indicating that the plurality of torque modules 110 A-F have extended (radially in the direction of arrow 60 ) are making up the plurality of riser bolts 32 A-F while the riser string 40 is being supported by the spider 50 .
FIG. 51 is a side view schematically indicating that the plurality of torque modules 110 A-F have completed the make up of the plurality of riser bolts 32 A-F and such modules are retracting (radially in the direction of arrow 61 ) to their home position.
FIG. 52 shows the now made up joint (flanges 43 and 47 ) between the second 42 and first 46 riser sections is being lowered (in the direction of arrow 63 ) by the rig lifting elevator 22 after the spider 50 has been retracted (in the direction of arrows 54 ).
FIG. 53 is a side view of the now made up joint (flanges 43 and 47 ) between the second 42 and first 46 riser sections is being lowered (in the direction of arrow 63 ) by the rig lifting elevator 22 (which supports the riser 40 string by attachment to the upper flange 45 of the second riser section 42 ) after the spider 50 has been retracted.
FIG. 54 is a side view of the elevator 22 supporting the riser string 20 by the upper flange 45 of the second riser section 42 and located this upper flange 45 in the spider 50 for support. Arrows 52 schematically indicate that the spider 50 has closed to support riser string 40 by supporting upper flange 45 .
FIG. 55 is a close up view of the elevator 22 supporting the riser string 40 by the upper flange 45 of the second riser section 42 and having placed the upper flange 45 on the spider 50 for support.
FIG. 56 is a close up view of the elevator 22 being removed (schematically indicated by arrow 64 ) from the upper flange 45 of the second riser section 42 . Riser string 40 (along with second riser section 42 ) is supported by spider 50 .
FIG. 57 is a perspective view of all six torque modules 110 A-F in their home positions and set up in the break out mode on spider 50 . Radial arrows 60 and 61 schematically indicate extension and retraction of each of the modules. Upper and lower arrows 62 and 63 schematically indicated upward movement and lower movement of individual drive sockets 1010 A-F for each of the modules.
Rotational Counter
In one embodiment a rotational counter can be used to count the number (and possibly the direction) of revolutions of driver tip or socket 1010 after driver tip or socket 1010 engages the head of bolt 32 . Because the pitch of the threads on bolt 32 are known the distance of vertical movement of bolt 32 can be determined. This distance of vertical movement of bolt 32 can be made up by vertical lifting and lowering mechanism 1300 in combination with height sensor 1350 . The counter of rotations of bolt 32 can be for one or more portions of the vertical movement of bolt 32 . Different portions can be analyzed because of the step where bolt 32 freely spins between the upper and lower flanges ( 43 and 47 ) and/or drops between these two upper and lower flanges ( 43 and 47 ).
In one embodiment a rotational counter can be used to count the number (and possibly the direction) of revolutions of vertical lifting and lowering screw 1330 (and/or motor 1310 ) to calculate the vertical movement of driver tip or socket 1010 . Because the pitch of the threads on screw 1330 are known the distance of vertical movement of bolt housing 1200 (and tip or socket 1010 ) can be determined. This distance of vertical movement can be used to control lifting and lowering mechanism 1300 during various steps in the various sequences.
LIST OF REFERENCE NUMERALS
The following is a list of reference numerals used in the present application:
Reference Numeral
Description:
10
perspective view of preferred embodiment
20
rig
22
lifting elevator for rig
32
bolt
40
riser
42
riser section
43
flange
44
floatation/insulation material for riser section
45
upper flange
46
riser section
47
flange
48
projection of cylinder
49
gap
50
spider
52
arrow (extension)
54
arrow (retraction)
60
arrow
62
arrow
64
arrow
66
arrow
68
arrow
70
arrow
80
control panel/hydraulic fluid source
100
wrench system
110
wrench
140
sliding housing
142
top
144
bottom
146
front
148
rear
150
side wall
152
side wall
154
foot connector
155
foot connector
156
foot connector
157
foot connector
160
brace
170
brace
180
brace
190
tracks
192
track
194
track
196
track
198
track
300
base
310
top
320
bottom
330
front
331
radial tabs
332
connecting pins
334
connecting pins
340
rear
350
guide system
352
guide shaft
354
guide shaft
356
front plate
357
extension adjusters
358
rear plate
359
retraction adjusters
360
positioning system for base
362
hydraulic cylinder and piston
363
rod
364
hydraulic cylinder and piston
3654
rod
400
wrench
406
wrench body
410
top
420
bottom
440
first end
450
second end
452
arrows
460
top opening for driver
470
bottom opening for driver
480
opening for cylinder pivot rod
490
opening for vertical lifting and lowering screw
498
bore for reaction bar
500
reaction bar
510
first end
520
second end
590
high torque driver
600
drive gear
610
plurality of angular teeth
620
opening in drive gear for drive pin
700
reciprocating cylinder
702
arrows
706
arrows
708
arrows
710
cylinder
712
first interior wall
713
extension port
714
second interior wall
715
retraction port
720
cylinder yoke
722
pressure port
730
opening for pivot pin
734
pivot pin
740
piston
750
piston rod
760
tip for piston rod
770
arrow
772
arrow
774
arrow
778
pivot
800
first drive plate
810
second drive plate
820
drive plate extension
825
spacer
830
bore in first drive plate for drive gear
840
bore in second drive plate for drive gear
850
bore in first drive plate for piston rod tip
852
bore in second drive plate for piston rod tip
860
bore in first drive plate for drive pawl
870
bore in second drive plate for drive pawl
880
first bushing
881
opening
882
second bushing
883
opening
884
plurality of connectors
900
drive pawl
910
pivot tips for drive pawl
920
drive pawl biasing member (e.g., springs)
1000
driver
1010
driver tip
1012
axis of rotation
1020
opening for head of bolt
1030
depth of opening
1040
driver shaft
1042
first end
1044
second end
1046
cross sectional shape
1050
high speed connection area
1052
plurality of teeth for high speed connector
1200
high speed/low torque driver
1210
motor
1220
belt
1222
tension pulleys
1230
housing
1232
first end
1234
second end
1236
top
1238
bottom
1240
opening for vertical lifting and lowering screw
1242
threaded area for vertical lifting and lowering screw
1250
plurality of tracks
1252
track
1254
track
1256
track
1258
track
1300
vertical lifting and lowering mechanism
1310
motor
1330
vertical lifting and lowering screw
1332
arrow
1334
arrow
1350
height sensor
1360
moving indicator for sensor
1370
depth to known origin/level/standard
1400
screw lifting mechanism
1402
arrow
1404
arrow
1410
lifting fork
1420
plate
1430
track
1432
track
1440
driving hydraulic cylinder and piston or pair of
driving cylinders and pistons
It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention set forth in the appended claims. The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims. | An improved multi-bolt and nut torque wrench for installing and removing bolts or nuts from flanged joints or the like which includes a plurality of torque stations having a plurality of high torque wrenches for engaging the heads of the bolts or nuts during a high torque phase of removal or installation; a plurality of low-torque motors operatively engaged with the wrenches for rotating the bolts or nuts during the low torque phase of removal or installation; a source of hydraulic fluid for driving the low-torque motors during the low-torque phase, and driving the high-torque wrenches during the high torque phase; and a mechanism for switching between the two phases depending on the torque needed. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to matrix multiplier systems and, more particularly, to such systems utilizing fiber optic coupling arrays.
2. Description of the Prior Art
The present invention performs a specific class of matrix operations. This operation is the multiplication of an N-dimensional vector by an N-by-M-dimensional matrix. The product of such an operation is an M-dimensional vector. In matrix algebra notation, the operation is written symbolically as
A=B×E, (1)
where B=B (b 1 , b 2 , . . . , b N ) is an N-dimensional vector having N components b 1 , b 2 , . . . , b N ; ##EQU1## is an N-by-M-dimensional matrix having N-times-M components; and A=A (a 1 , a 2 , . . . , a M ) is an M-dimensional vector. An alternative symbolic representation of matrix multiplication is written as follows: ##EQU2## where i and j are indices for the vector and matrix components (i=1, 2, . . . , M and j=1, 2, . . . , N), and the symbol ##EQU3## means that all of the products b j ×e ji are summed for every value of j between 1 and N. Equation (2) is the formula by which the product components are calculated if the components b j and e ji are known.
Multiplication operations of the type indicated by Equations (1) and (2) conventionally are berformed by electronic digital binary computers. This conventional process is performed by loading each of the components to be multiplied (the b j s and the e ji s) into digital memory devices, extracting the components one-by-one from memory into an arithmetic logic unit (ALU), and then the ALU multiplies the components and stores the products in selected memory elements.
This operation of matrix multiplication is considered, by people who are acquainted with digital computers, to be both time-consuming and memory extensive. Depending on the size of the vectors and the matrices, and depending on the speed of memory access, this operation may require several seconds and many tens of thousands of memory locations. Consequently, the computers required to perform this operation have high-capacity memories, and they are costly.
Several examples are known in the prior art of the use of electro-optical systems for matrix-vector multiplication to circumvent the dependence upon computers for such operations. Examples of such may be found in U.S. Pat. Nos. 3,305,669 of Fan, 3,588,486 of Rosen, 3,944,820 of Stotts, and 4,009,380 of Bocker et al. Some of these systems depend upon optical masks or the equivalent (either transmissive or reflective) in modulating light energy. The Stotts patent uses polarized light in conjunction with successive phase-synchronized modulators and optical waveguides.
U.S. Pat. Nos. 3,906,220 of Delingat and 3,937,952 of Ripley et al have been found which use intermixed sets of optical fibers for various specific purposes. The former is directed to an optical correlator, whereas the latter is directed to use in a keyboard for multi-digit encoding.
The present invention employs to particular advantage in a matrix multiplying system an integral array of substantially identical, fiber optic couplers. These couplers are of the unidirectional type, referred to as launch couplers, disclosed for example in my U.S. Pat. No. 4,307,933 entitled OPTICAL FIBER LAUNCH COUPLER, of which I am named as inventor with Phillip B. Ward, Jr. The fabrication of an array of such launch couplers is disclosed in U.S. application Ser. No. 333,955 filed Dec. 23, 1981, entitled FIBER OPTIC COUPLER ARRAY AND FABRICATION METHOD of John P. Palmer and Phillip B. Ward, Jr., assigned to the assignee of this invention. The disclosure of that application is incorporated herein by reference. In brief, an array of substantially identical launch couplers is fabricated by preparing first and second support blocks with pluralities of parallel grooves and placing appropriate optical fibers in the grooves. Each launch coupler comprises a launch fiber and a throughput fiber. Epoxy resin is applied to embed the respective fibers in their blocks and then the resin and embedded fibers are lapped to develop opposed mating planar surfaces. The launch fibers are lapped entirely through the cores to expose severed end surfaces of generally elliptical shape. The throughput fibers are lapped only deep enough to expose a corresponding surface of like extent and dimensions. The two blocks are then joined at the planar surfaces, and the array of launch couplers is aligned while applying light signals to the input ports of two launch fibers at opposite ends of the array and monitoring the light output at the output ports of the corresponding throughput fibers until the output is maximized. Preferred apparatus for use in the alignment procedure is disclosed in U.S. Pat. No. 4,302,267 entitled OPTICAL FIBER MATING APPARATUS AND METHOD of Palmer and Ward. Afterward the two blocks are affixed to each other by epoxy resin or other suitable adhesive. An array of launch couplers fabricated in this fashion can be used as the basis of a matrix multiplier system.
SUMMARY OF THE INVENTION
In brief, arrangements in accordance with the present invention incorporate a launch coupler array of the type just described in matrix multiplier systems. In such an array, light energy applied to the launch fiber exits from the opposite throughput fiber end with about 1 dB of loss (the insertion loss) and with very little light appearing at the other throughput fiber end. However, light entering either throughput fiber end exits from the other throughput fiber end with only about 0.5 dB of loss (the throughput loss). For light applied to the throughput fiber, almost no light appears at the end of the launch fiber. With suitable fiber sizes and spacing, a single tier array of 50 couplers can fit in a volume of 1 inch long×0.5 inches high by 0.5 inches deep. Such tiers can be stacked to achieve corresponding volumetric efficiency with many thousands of individual launch coupler elements.
In the present invention, such arrays are combined with optical reflectors in the manner disclosed in my prior U.S. Pat. No. 4,310,905 entitled ACOUSTICAL MODULATOR FOR FIBER OPTIC TRANSMISSION, the disclosure of which is incorporated herein by reference. Briefly, that patent describes particular ways in which varying the distance between the end of an optical fiber and a reflective surface can be used to vary the amount of reflected light transmitted by the fiber. The spacing can be fixed for certain signal transmissions, or it can be varied in accordance with a modulation signal for other signal transmissions. The use of such concepts in conjunction with the launch coupler arrays as previously disclosed provides added flexibility in the realization of fiber optic matrix multiplier systems of the present invention.
BRIEF DESCRIPTION OF THE DRAWING
A better understanding of the present invention may be had from a consideration of the following detailed description, taken in conjunction with the accompanying drawing in which:
FIG. 1 is a schematic representation of a single launch coupler employed in arrangements of the present invention;
FIG. 2 is a drawing of a plurality of such couplers in an integral array;
FIG. 3 is a schematic diagram representing the interaction between a single fiber end and a reflective surface as utilized in the present invention;
FIG. 4 is a schematic block diagram illustrating a single fiber optic system, the principles of which are employed in the present invention;
FIG. 5 is a schematic representation of a simplified embodiment exemplifying the present invention;
FIG. 6 is a schematic block diagram of one particular arrangement in accordance with the invention;
FIG. 7 is a diagram illustrating, in enlarged form, a particular portion of the diagram of FIG. 6;
FIG. 8 is a diagram illustrating a particular element which may be used in arrangements of the present invention;
FIG. 9 is a schematic block diagram illustrating one particular form of the arrangement of FIG. 5;
FIG. 10 is diagram illustrating a portion of the arrangement of FIG. 5;
FIG. 11 is a schematic block diagram illustrating the use of the structure of FIG. 10;
FIG. 12 is a diagram similar to that of FIG. 11, but illustrating a variant thereof;
FIG. 13 is a graph showing the effect of variations in the parameters illustrated in FIG. 10;
FIGS. 14-17 are various representations of patterns with which arrangements of the present invention may be used to advantage;
FIG. 18 is a graph of two waveforms showing results from using arrangements of the present invention;
FIG. 19 is a schematic circuit diagram incorporating particular arrangements of the present invention; and
FIG. 20 is a bar graph illustrating the results of the use of arrangements of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the schematic diagram of FIG. 1, a launch coupler 10 of the type utilized in the present invention is shown comprising a launch fiber 12 and a continuous throughput fiber 14. It will be noted that the launch fiber is preferably smaller in diameter than the throughput fiber. In preparation of the launch coupler, both fibers 12 and 14 are mounted in appropriate grooves on respective blocks (not shown), embedded in epoxy, and then respectively lapped to develop optically flat, planar surfaces. The depth of lapping of the launch fiber is sufficient to completely sever the fiber core. The other portion of the launch fiber 12 is omitted from the diagram for the sake of simplicity, since it is not used. The throughput fiber 14 is lapped to a sufficient depth to develop an exposed surface of the fiber core which substantially matches the exposed surface of the severed launch fiber, and these two exposed surfaces are matingly joined at the coupling interface 16. The result is a three-port coupler which is particularly efficient as a unidirectional, or launch, coupler. Light entering Port A exits Port C with about 1 dB of insertion loss, while the light appearing at Port B is negligible. However, light entering either Port B or Port C exits the other port of the throughput fiber 14 with a throughput loss of about 0.5 dB and with almost no light appearing at Port A. An integrated array of such couplers, fabricated in accordance with the description set forth hereinabove, is particularly effective when used in arrangements in accordance with the present invention to develop fiber optics in matrix multiplier systems.
Such an array is shown in FIG. 2 in the form of an assembly 17 comprising a base plate 18 having a plurality of holes, to facilitate mounting in alignment apparatus, and a pair of blocks 19, 20 to which pluralities of optical fibers 12, 14 are affixed. The lower block 20, to which the launch fibers are affixed, may be mounted to the plate 18 by any suitable means, for example by wax or adhesive (not shown). The upper block 19, to which the continuous throughput fibers 14 are affixed, is mounted to the upper surface of the block 20. Each of the blocks 19, 20 is fabricated with an optically flat mating surface lapped into a mound of epoxy resin, shown at 21. These mating surfaces are secured together by a suitable adhesive, such as epoxy, having the desired optical properties. Each of the launch fibers 12 of the assembly 17 is aligned with and joined to a corresponding throughput fiber 14 to develop an individual launch coupler of the type shown and described with respect to FIG. 1.
Each of the blocks 19, 20 of the assembly 17 of FIG. 2 has an arcuate surface on the side facing the other block and a plurality of longitudinal grooves formed therein for receiving the respective optical fibers 12 or 14. These grooves are cut across the curved surface of the respective blocks, are evenly spaced relatively close together, and are of uniform depth. The depth is selected to correspond to the size of the optical fibers mounted in the grooves. Thus, lapping of the epoxy resin and all of the fibers on a given block to develop an optically flat planar surface and joining of the two blocks together at their flat surfaces results in an array of substantially identical, individual launch couplers like that shown in FIG. 1.
Launch coupler arrays are utilized in the present invention by placing the ends of the throughput fibers adjacent a reflective surface. This is represented in FIG. 3 for a single fiber 14 in which the end designated Port C is adjacent a reflective surface 22, separated therefrom by a distance h. Light exiting Port C diverges in a conical pattern and this is reflected back to a plane 23 at the end of fiber 14. As indicated by the arrows, a portion of the reflected light will re-enter Port C for transmission back along the fiber 14. It will be seen that the proportion of the light exiting Port C which is reflected from the surface 22 back to Port C will vary as a function of the distance h. If this reflective surface 22 is a pressure sensitive reflective membrane 22', such as is indicated in FIG. 4, the reflected light is modulated by the function of the signal driving the membrane 22'.
In the block diagram of FIG. 4, a single coupler 10 as in FIG. 1 is shown having an input fiber 24 coupled to the launch fiber Port A, a bi-directional fiber 28, coupled to Port C, and an output fiber 30, coupled to the Port B. The input fiber 24 is positioned to receive input light signals from a photodiode 32 connected to be driven by an electronic driver 38. The reflective, pressure sensitive diaphragm 20' is coupled to a cone 34 positioned to be driven by a varying pressure wave front 36. The output fiber 30 is positioned to apply output light signals to a photodiode 40 which is coupled to an electronic receiver 42. Thus, the electrical signal generated by the driver 38 is converted at the photodiode 32 into a light signal which is applied through the coupler 10 and along the bi-directional fiber 28 to the reflective diaphragm 20'. There the light signal is reflected, the portion being received and transmitted back along the fiber 28 being modulated by the function of the pressure wave 36. As modulated, the light signal travels along fibers 28 and 30, is converted to electrical signals at the photodiode 40 and applied to the receiver 42.
A simplified array of such couplers and reflectors corresponding to the illustration of FIG. 4 is shown by way of example in FIG. 5, in which a small number of vector and matrix components are shown. This example is easily generalized to an arbitrary number of vector and matrix components. As discussed herein, the components of vectors A and B (Equations (1) and (2) above) are represented by optical signals, and the components of matrix E are represented by either static positions or by amplitudes of vibration of optical reflecting surfaces (mirrors). Hereinafter, the optical signals representing the components of vector B, and which are directed into the matrix multiplier, are referred to as the input vector components, b j ; and the optical signals representing the components of vector A, and which are directed out of the matrix multiplier, are referred to as the output vector components.
FIG. 5 illustrates an exemplary multiplier system 50, of which the key component is a 12-element monolithic array 52 of fiber optic directional couplers arranged in a 3×4-element matrix. Each element of this array is a three-port directional coupler of the type shown in FIG. 1 and the coupler array per se corresponds to FIG. 2. The 12 input fibers 54--the launch fibers--are arranged in four groups 56 of three fibers each. Each of these four input bundles receives an optica1 signal which represents a component of the input vector B; e.g., the third bundle from the left receives an optical signal representative of the component b 3 . This signal divides equally among the three fibers in that bundle, designated A, B and C, and the optical signal in each of these fibers is also representative of the vector component b 3 . The three fibers in this bundle transmit the optical signal b 3 to the 3rd, 7th, and 11th directional couplers, counting from the left, whereby the optical signal b 3 is coupled into the 3rd, 7th, and 11th optical fibers on the opposite side of the coupler array. These latter fibers are designated as "bidirectional" fibers because when reflective surfaces 57 are located opposite the ends of these fibers, a fraction of the optical signal emerging from each bidirectional fiber is reflected back into the same fiber and is transmitted in the opposite direction from the incident light energy. The relative magnitude of the signal coupled back into the fiber depends on the spacing between the reflective surface and the end of the fiber, as explained above in connection with FIGS. 3 and 4. For ease of presentation, the reflective surfaces 57 are represented as associated with modulating signals of the form e ji . This relative fraction of light reflected back into the fiber is representative of an element of the matrix E; consequently the magnitude of light coupled back through the coupler and into an output fiber is representative of the product b 3 ×e 3i , where the index i is 1 for coupler No. 3, 2 for coupler No. 7, and 3 for coupler No. 11, as indicated in FIG. 5.
The 12 output fibers are grouped into three bundles 58 of four fibers each. Consequently the optical flux a i radiating from any one of these three bundles is the sum of the fluxes from each of the fibers in that bundle, and this summation is representative of the respective component of the output vector, A. A careful examination of each of the optical paths in FIG. 5 shows that the three components of the output vector are given by the expressions:
a.sub.1 =b.sub.1 e.sub.11 +b.sub.2 e.sub.21 +b.sub.3 e.sub.31 +b.sub.4 e.sub.41
a.sub.2 =b.sub.1 e.sub.12 +b.sub.2 e.sub.22 +b.sub.3 e.sub.32 +b.sub.4 e.sub.42 (3)
a.sub.3 =b.sub.1 e.sub.13 +b.sub.2 e.sub.23 +b.sub.3 e.sub.33 +b.sub.4 e.sub.43
Equations (3) are the same as Equation (2) when N=4 and M=3.
The input vector components are optical signals; that is, the intensity of light coupled into the input fibers is representative of the magnitude of the respective vector components. If the light coupled into the fibers is coherent, as from laser sources, then the amplitudes and the phases of the optical signals may be representative of amplitudes and phases of the respective vector components. However, the optical sources used to date with the present invention have been noncoherent.
The optical signals representing the input vector components may be presented to the input ports of the matrix multiplier in a variety of different ways. Four alternative means are listed and are described as follows:
(1) The optical signals may be generated by electro-optical light-generating devices such as by light emitting diodes (LEDs) or by injection laser diodes (ILDs).
(2) The optical signals may be picture elements (pixels) of an image projected by means of lenses onto the end-surface array of input fiber bundles.
(3) The optical signals may be pixels of an illuminated surface in close proximity to the end-surface array of input fiber bundles.
(4) The optical signals may be pixels of an image generated on the phosphor surface of a cathode ray tube in close proximity to the input bundles.
An example of the first case is represented by the use of the exemplary multiplier of FIG. 5 in the manner indicated for a single coupler in FIG. 4. In such an arrangement a separate LED 32 is provided at each input fiber bundle 56. The optical signals coupled into the fiber bundles are proportional to the current driven through the LEDs by external drivers 38. Consequently, the input vector components are represented by the analog drive current values for the respective LEDs, whereby these vector components are generated electronically, as by a conventional computer.
An example of the second case of generation of the input vector components is illustrated in FIG. 6, in which the input fibers 62 of the launch coupler array 60 are mounted in the manner shown in FIG. 7 to form a close-packed array 64. Each circle in the diagram of FIG. 7 represents the end surface of a fiber bundle and is the input port for a particular vector component. The example of FIG. 7 represents 288 pixels. Thus, each bundle, such as 66 in FIG. 7, contains as many optical fibers as there are output ports (fiber bundles 58 in FIG. 5). For example, a 0.045-inch diameter bundle of 3-mil diameter fibers contains about 212 such fibers. Consequently, if the 288 bundles in FIG. 7 formed the input fiber array in FIG. 6, and if each bundle contained 212 fibers, then the output array would contain 212 bundles of 288 fibers each. (In this case the directional coupler array would have 61,056 couplers). The arrangement of FIG. 6 further shows a lens 68 positioned to project an image 70 in the position 72 in front of the input fiber bundle 64. The output fibers 74 are similarly bundled in the manner described to provide an output fiber bundle 76. In accordance with the matrix arrangement of FIG. 5, these output fiber bundles 76 would comprise 288 fibers each, there being 212 such bundles 76. The block 79 represents an array of reflectors such as the reflector/modulator arrangement of FIG. 3 or FIG. 4. Alternatively, the block 79 may represent other reflective arrays such as are shown in FIGS. 9, 10, 11 or 12 and described hereinbelow.
FIG. 6 may be used to illustrate the third case of generation of input vector components in which a "hard copy" of the image is presented in close proximity to the fiber array, as the arrow 72 representing the image, rather than projecting the image through the lens 68. In this example, the image may be illuminated either from the front side (the side adjacent the fiber array) or from the back side. In this manner, light is transmitted to the input fiber bundles in proportion to light transmitted through, or reflected by, the image on the hard copy. Alternatively, the image presented to the input ports of the matrix multiplier in this manner may be a pattern on a manufactured surface to be processed by the matrix multiplier for the purpose of quality assurance.
An example of the fourth case of generation of the input vector components is like that illustrated in FIG. 6, except that the surface 78 of the input fiber bundle array is contoured to match the face plate of a cathode ray tube (CRT). The CRT may be the display element of an oscilloscope, or of a television receiver, or of a computer terminal.
In order to assure that each of the fibers in a given input fiber bundle is illuminated uniformly, it may be necessary in some applications of the four cases described above to provide a short optical diffusion rod in front of each of the terminated bundles. One such termination member 80 is illustrated in FIG. 8 as comprising a diffusion rod 82 held in position adjacent a bundle of optical fibers 84 by a support tube 86. The diffusion rod 82 is shown withdrawn slightly from the fibers 84 for the purpose of illustration. The diffusion rod 82 is a glass rod of uniform composition having the same index of refraction as the cores of the optical fibers 84. The length of the diffusion rod 82 is preferably about four times its diameter, which is the same as the diameter of a fiber bundle. Consequently, an array of diffusion rods placed in front of the input bundles may appear as shown for the optical fiber bundles in FIG. 7.
As has been indicated, a variety of alternative reflector configurations may be utilized in matrix arrays such as are shown in FIGS. 5 and 6, for example. The selection of the appropriate reflector configuration may depend on the nature of the matrix elements and on the strength of the optical signal relative to background level. If all of the matrix elements have the same sense (unipolar matrix elements), then the value of a matrix element may be directly proportional to the fraction of light reflected back into the bidirectional fiber. As noted above with respect to FIGS. 3 and 4, for example, this reflection coefficient is related to the spacing between the end of a bidirectional fiber and the reflective surface opposite that fiber. Alternatively, the value of a unipolar matrix element e ji may be represented by the amplitude of vibration of an oscillating reflector surface. This latter structure is preferred when high resolution and accuracy of the matrix elements is required. The alternating reflected signal can be filtered in the electronic receiver in order to discriminate between the signal representing the matrix element (which is due to reflection by the oscillating reflector) and the constant light level due to reflection by the directional coupler.
Since the modulation of the input light levels by the reflectors is inherently unipolar (because the reflection process is passive), bipolar matrix elements cannot be represented by static reflectors. However, bipolar matrix elements can be represented by the amplitude of vibration of oscillating reflectors, wherein matrix elements with opposite senses are represented by reflectors which vibrate with a 180-degree phase difference. This effect is illustrated in FIG. 9, in which an array 90 of three identical launch couplers is shown with signal inputs b 1 , b 2 and b 3 applied to three input, or launch, fibers 92, respectively. The optical reflection coefficients at the reflector elements 93, equivalent the modulation of light signals re-entering the bi-directional fibers 96, are e 1 sin(ωt), e 2 sin(ωt), and e 3 sin(ωt+π), respectively. The resulting optical signals in the three output fibers 94 are b 1 e 1 sin(ωt), b 2 e 2 sin(ωt), and b 3 e 3 sin(ωt+π), respectively. If these three output signals are summed at a common photodetector, as by joining the three fibers 94 together in the manner shown in FIG. 9 adjacent a photodiode as in FIG. 4, then the output signal (electrical) from that photodiode is proportional to ##EQU4## Consequently, the matrix coefficient, e 3 , is effectively opposite in sense to the matrix coefficients, e 1 and e 2 .
In applications where static reflectors are appropriate, they may be fixed or adjustable. For example, the reflective surfaces may be attached to individual adjustment screws, as illustrated in FIG. 10. In the arrangement shown in FIG. 10, the coupler array 90 is depicted with bidirectional fibers 96 having their terminal ends adjacent individual reflectors 98. These reflectors 98 are positioned at different selected distances from the ends of the bidirectional fibers 96, the spacing being established by adjusting screws 100 on which the reflectors 98 are mounted being threadably fixed within a support block 102. The reflectors 98 are piezoelectric crystals supported on the ends of the adjusting screws 100 for modulating the light signal being directed back into the bidirectional fibers 96. The piezoelectric crystals 98 are driven via conductors (not shown) from a suitable driving source and have reflecting surfaces facing the fibers 96. Thus, the positioning of the reflectors 98 by means of the adjusting screws 100 develops a reference spacing, or DC bias, which is varied in accordance with the modulating waveform applied to the piezoelectric crystal.
An alternative modulating arrangement is depicted schematically in FIG. 11 in which the coupler array 90 and bidirectional fibers 96 are shown in operative position adjacent a terraced reflector block 104. The block 104 is formed with a terraced contour comprising individual stepped surfaces 106 facing corresponding ends of the fibers 96. The terraced contour may be machined or etched on the block 104 and the relative spacing between the respective stepped surfaces and the corresponding ends of the fibers 96 determines the static reflection coefficients for the matrix multiplier. It will be understood that the reflector block 104 may be a piezoelectric crystal or some other reflector assembly which may be caused to vibrate by the application of a varying modulation signal.
A variant of the arrangement of FIG. 11 is shown in FIG. 12 in which two reflector blocks 104A and 104B are shown associated with corresponding optical fibers 96 which are arrayed in two groups. Each of the blocks 104A and 104B is formed in the manner described for the block 104 of FIG. 11 and is pivotably mounted on a bar 110 at pivot points 112A and 112B. The bar 110 is supported on a fulcrum support 114 and the entire structure is movable in the fashion of a seesaw. As one reflector block, such as 104B, moves toward its corresponding set of bidirectional fibers 96, the other reflector block 104A is moving away from its corresponding set of fibers. The pivot arm 110 is coupled by arm 115 to be driven by a mechanical vibrator 116. Inasmuch as the dynamic light intensity modulation depends on the slope of the modulation curve as shown in FIG. 13, the reflector mean positions (i.e., the mean spacing of the blocks from the fibers 96) are selected accordingly by positioning the support 114.
FIG. 13 is a graph showing the effect of three different mean positions of the reflector block assembly of FIG. 12. In FIG. 13, output intensity is plotted as a function of the fiber-to-fiber reflector gap. Each of the reflector elements vibrates with the same amplitude (because they are on a monolithic structure). Consequently, the relative values of the dynamic reflection amplitudes are proportional to the slopes of the calibration curve at the three mean position locations which are indicated. In other words, the range and resolution of the matrix element representations depend on the nonlinearity of this calibration curve.
In various arrangements embodying the invention, the reflected light entering the bidirectional fibers is transmitted through the coupling array to the respective output fibers. As illustrated in the example of FIG. 5, the output fibers from all of the coupler elements are grouped in a set of bundles in a manner such that each output bundle includes one output fiber corresponding to each of the input bundles. Thus, as shown in FIG. 5, where there are four input bundles each having three input fibers, there are three output bundles each having four output fibers. Each of these output bundles is terminated at an interface to a separate electro-optical sensor such as photodiode, in the manner shown for an individual fiber element in FIG. 4. The output of this sensor is an electrical current which is proportional to the summation of the light outputs from each of the fibers in the corresponding output bundle.
Alternatively, the end surfaces of each of the output bundles may be terminated by an optically diffusion rod (see FIG. 8) such that the optical output from each of the bundles is diffused uniformly as it exits from the diffusion rod. In such an arrangement, the output from matrix multiplier is an array of diffusion rod surfaces, each of which emits a uniform spot of light. Such an array may be arranged in a planar (or curved) surface for visual display or for photographic reproduction.
The following example illustrates the application of an embodiment of the present invention to a specific method of pattern recognition. FIG. 14 illustrates a specific array of dark circles in a symmetrical pattern. FIGS. 15 and 16 illustrate similar arrays in different symmetrical patterns. The array of FIG. 14 is periodic with a fundamental spatial period of five spaces, where each line is scanned from left to right. The arrays in FIGS. 15 and 16 are periodic with fundamental spatial periods of 17 and eight spaces, respectively. FIG. 17 shows a composite matrix of dark circles obtained by superposition of the arrays of FIGS. 14-16. The periodicities (i.e., the symmetry) of the pattern in FIG. 17 are not apparent from a casual view of the figure. However, if an array of input fiber bundles is superimposed on the pattern of FIG. 17, one input bundle for each space of the array, such that the bundles opposite the dark circles are not illuminated and the bundles opposite the light circles are illuminated by a single uniform light intensity, then the matrix multiplier provides the spatial frequency components of each of the superimposed periodic patterns by means of Fourier analysis.
There are 392 spaces in the arrays of FIGS. 14-17. This also is the number of input fiber bundles. Suppose it is desired to resolve the first 30 spatial frequency components of the pattern in FIG. 17. Then each of the 392 bundles will contain 30 fibers. This analysis is achieved by way of the Fourier transform expressed by Equation (5): ##EQU5## The argument of the sine function is periodic with respect to x=nx o and with respect to λ=λ o /m. Let x o be the lateral dimension of one space (say, 1 millimeter), and let λ o be a dimension longer than the longest expected wavelength of periodicity (say, 60 spaces or 60 mm). Then Equation (5) becomes: ##EQU6## where m=1, 2, . . . , 30. Observe that for this example b n is binary, i.e., it is 1 for a space which is light, and it is 0 for a space which is dark. In general, however, a continuous spectrum of gray scales may exist with no change required in the apparatus of this invention.
The values for e nm =sin 2π/60 nm are the matrix elements for the positions of the reflectors opposite the fiber optic coupling elements. These reflectors are indexed by the integers n=1, 2, . . . , 392 and m=1, 2, . . . , 30. Note that the positions of the reflectors could be static if the matrix values, e nm , were all of the same sign (all positive or all negative). However, in this example, the values of e nm are not all the same sign; some are positive and others are negative. Consequently, an alternative to static reflectors has been devised to provide an effective sign for the matrix elements. This involves phase modulation of fluctuating reflector positions.
Consider two components of the output vector element a m in Equation (7); The ith element is b i sin (2πim/60), and the jth element is b j sin (2 πjm/60), where i and j have different integer values in the range of the index n. Suppose the matrix elements e im and e jm have positive and negative values, respectively, and that these matrix elements are represented by oscillating reflectors. Suppose, further, that the time dependence of the reflected signals is as indicated in FIG. 18, which is a graph of two waveforms plotted on scales of amplitude versus time in arbitrary units. Observe that the two oscillations shown in the figure are 180° out of phase, and the amplitudes of oscillation are not the same. That is, the reflected signals have different amplitudes, but the amplitudes of vibration of the reflectors have the same value. This is accomplished by making use of the nonlinearity of the reflection versus position of the reflector, as was illustrated in FIG. 13. When the reflected optical signals are summed at the optical port corresponding to a m , the alternating components are added, constructively, when those components are of the same sign (i.e., in phase), and they are subtracted when they are of opposite sign (i.e., 180° out of phase). The constant background intensity of the summed signal is filtered out by using an AC-coupled amplifier following the receiver photodiode at each output port. Such an arrangement is shown schematically in FIG. 19, in which a photodiode 120 is shown adjacent the end of an output bundle 122 in a position to monitor the light exiting therefrom. The signal from the photodiode 120 is applied to the input of a first amplifier 124, the output of which is AC coupled through a capacitor 126 to a second amplifier 128. The amplified AC signal is then coupled through a further capacitor 130 to a diode rectifier 132, associated filter 134 and output 136. By virtue of the circuit of FIG. 19, the output vector components a m (m=1, 2, . . . , 30) are all represented by AC electronic signals (each of which may be rectified by a stage following each of AC amplifiers if DC levels are preferred over AC levels).
In general, the vibrating reflectors which represent the matrix elements in Equations (1) and (2) may be independently controlled, as by individual piezoelectric crystals each causing deflection of individual reflective surfaces, in the manner shown in FIG. 10, for example. However, in many applications such as the example of FIG. 12, all of the reflective surfaces are driven synchronously in two groups, each group being driven 180° out of phase with the other (if the matrix elements include both positive and negative senses). In the present case, it is sufficient to have all of the reflectors representing matrix elements with positive sense on one vibrating support structure and all of the reflectors representing matrix elements with negative sense on another vibrating support structure. This greatly simplifies the reflector mechanism and the drive electronics.
When the time dependence of the matrix elements is included in the output components (Equation 5), the result is ##EQU7## where p=0 when sin (2πnmx o /λ o )>0, and p=1 when sin (2πnmx o /λ o )<0; that is to say, the index p depends on the index n. The output (product) vector components in Equation (8) are represented by (i.e., proportional to) the optical intensities at the respective output ports of the matrix multiplier disclosed herein.
If the output signals represented by Equation (8) are peak detected by a circuit as shown in FIG. 19, then the 30 output levels for the present example are as shown in FIG. 20 which is a bar graph of the Fourier transform of the image pattern in FIG. 17. The strong signals emanating from output bundles Nos. 12, 15, and 24 are the first harmonic corresponding to a period of five spaces (FIG. 14), the second harmonic corresponding to a period of eight spaces (FIG. 16), and the second harmonic corresponding to a period of 17 spaces (FIG. 15), respectively. This signature is characteristic of the patterns in FIGS. 14-17 and of the particular dimensions of the matrix multiplier.
The resolution limits of the Fourier transform obtained from this matrix multiplier increase as the numbers of input and output vector components are increased. Since, in the present example, λ o /x o was selected to be equal to 60, and since neither eight nor 17 factor into 60, the fundamental harmonics for these periods do not appear in the output array shown in FIG. 20. However, if the number of matrix elements, and the number of output bundles, had been increased by a factor of two, then the fundamental harmonic for the 8-space period would have appeared prominently at the 15th bundle (because 120÷8=15).
Although there have been described above specific arrangements of a fiber optic matrix multiplier in accordance with the invention for the purpose of illustrating the manner in which the invention may be used to advantage, it will be appreciated that the invention is not limited thereto. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art should be considered to be within the scope of the invention as defined in the annexed claims. | A matrix multiplier system incorporating an integrated fiber optic coupling array in combination with an arrangement for individually modulating the signals on the respective optical fiber transmission lines to develop the matrix multiplication. Each of the individual couplers accomplishes the coupling of an input signal into a bi-directional fiber optic transmission line with high efficiency and unilateral coupling effect. The signal thus coupled into the bi-directional transmission line is reflected back to the coupler output after multiplication by the modulating vector component for the individual coupler element. Because of the fabrication of a large number of identical fiber optic couplers in a compact, integral array and the manner in which the light signals can be modulated, the matrix multiplier system is extremely effective in pattern recognition, signal discrimination, selected signal enhancement, and the like. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel-vapor treatment method and apparatus for an internal combustion engine, wherein, to prevent air pollution and fuel loss, fuel vapor (hereinafter called the vapor) emitted from a fuel tank is temporarily stored and then released into an intake system in accordance with the engine operating condition.
2. Description of the Related Art
Generally, in prior known fuel-vapor treatment methods and apparatus, fuel vapor is adsorbed onto an adsorbent, such as activated charcoal, contained in a canister, and during engine operation, the adsorbed vapor is desorbed and released into an intake system by utilizing the negative pressure created by engine intake stroke (this process is hereinafter called the "canister purge"). Control of the purge is performed by using a solenoid valve installed in a purge passage communicating between the canister and an intake passage downstream of the throttle valve, the solenoid valve being controlled to open or close the purge passage depending on the engine operating condition.
More specifically, when the engine operating condition has passed from an operating range where purge is not performed (low load, low rpm range) to an operating range where purge is performed (high load, high rpm range), the solenoid valve is opened. Conversely, when the engine operating condition has passed from the operating range where purge is performed to the operating range where purge is not performed, the solenoid valve is closed. During purging, the duty cycle of the solenoid valve is controlled to control the purge gas amount in accordance with the engine operating condition. In a commonly employed method for such duty cycle control, control is performed so that a prescribed purge gas amount is obtained proportional to the intake air amount, that is, the purge ratio (the ratio of the purge gas amount to the intake air amount) is maintained constant. For the above prior art, refer, for example, to Japanese Patent Unexamined Publication No. 4-72453 (corresponding U.S. Pat. No. 5,323,751).
However, in the intake-air-amount-proportional purge as described above, no serious consideration has been given to the density of vapor to be purged into the intake passage. That is, the vapor actually charged into the intake passage through the solenoid valve includes not only the vapor from the canister but also the fuel vapor being emitted directly from the fuel tank. The density of the vapor purged into the intake passage is therefore determined by the tank vapor, the canister vapor, and the purge air amount which is the amount of atmosphere drawn into the canister. While the canister vapor amount increases in proportion to the purge air amount, the tank vapor amount tends to be held substantially constant regardless of the purge air amount.
Accordingly, when the density of the canister vapor is low and the density of the tank vapor is high, if the solenoid valve is operated to vary the purge gas amount, the density of the resulting mixture will vary greatly. More specifically, when the solenoid valve is operated toward an open position to increase the purge gas amount, only the canister vapor amount increases while the tank vapor amount remains constant. As a result, the overall density of the vapor mixture charged into the intake passage through the solenoid valve decreases because of the low density of the canister vapor; therefore, in a control operation for correcting the fuel injection amount based on the purge gas amount, the moment that the solenoid valve is operated toward its open position, the air-fuel mixture becomes lean, hence causing perturbations in the air-fuel ratio. On the other hand, when the solenoid valve is operated toward a closed position to decrease the purge gas amount, only the canister vapor amount decreases while the tank vapor amount remains constant. As a result, the overall density of the vapor mixture charged into the intake passage through the solenoid valve increases since the density of the canister vapor is low; therefore, in the control operation for correcting the fuel injection amount based on the purge gas amount, the moment that the solenoid valve is operated toward its closed position, the air-fuel mixture becomes rich, hence causing perturbations in the air-fuel ratio.
SUMMARY OF THE INVENTION
In view of the above situation, it is an object of the present invention to provide a fuel-vapor treatment method and apparatus for an internal combustion engine, wherein perturbations in air-fuel ratio are suppressed by providing means for preventing the density of the vapor mixture purged into the intake passage from varying substantially when the density of the fuel vapor being emitted directly from the fuel tank is high as compared to the density of the fuel vapor released from the canister. Thus, it is also an object of the present invention to improve the precision of air-fuel ratio control and to thereby contribute to exhaust gas purification.
To accomplish the above objects, according to the present invention, there is provided a fuel-vapor treatment method for an internal combustion engine equipped with a canister for temporarily adsorbing and storing fuel vapor emitted from a fuel tank for the engine, and a solenoid valve, installed in a purge passage communicating between the canister and an intake passage to the engine, for controlling a purge gas amount drawn into the intake passage through the purge passage, the method comprising the steps of: (a) correcting a fuel injection amount in accordance with the purge gas amount; (b) calculating a purge ratio, the ratio of the purge gas amount to an intake air amount for the engine, in accordance with operating conditions of the engine; (c) calculating, based on the purge ratio obtained in step (b), the duty cycle of a pulse signal used to control the operation of the solenoid valve; (d) making a judgement as to whether the fuel vapor emitted from the fuel tank and introduced into the intake passage directly through the solenoid valve is in a dense state as compared to the fuel vapor desorbed from the canister; and (e) limiting the duty cycle calculated in step (c) or the amount of change of the duty cycle to within a prescribed range when it is judged in step (d) that the fuel vapor from the fuel tank is in a dense state.
According to the present invention, there is also provided a fuel-vapor treatment apparatus for an internal combustion engine, comprising: a canister for temporarily adsorbing and storing fuel vapor emitted from a fuel tank for the engine; a solenoid valve, installed in a purge passage communicating between the canister and an intake passage to the engine, for controlling a purge gas amount drawn into the intake passage through the purge passage; fuel injection correcting means for correcting a fuel injection amount in accordance with the purge gas amount; purge ratio calculating means for calculating a purge ratio, the ratio of the purge gas amount to an intake air amount for the engine, in accordance with operating conditions of the engine; duty cycle calculating means for calculating, based on the purge ratio calculated by the purge ratio calculating means, the duty cycle of a pulse signal used to control the operation of the solenoid valve; density difference judging means for making a judgement as to whether the fuel vapor emitted from the fuel tank and introduced into the intake passage directly through the solenoid valve is in a dense state as compared to the fuel vapor desorbed from the canister; and duty cycle limiting means for limiting the duty cycle calculated by the duty cycle calculating means or the amount of change of the duty cycle to within a prescribed range when it is judged by the density difference judging means that the fuel vapor from the fuel tank is in a dense state.
In the fuel-vapor treatment method and apparatus for an internal combustion engine according to the invention, as described above, when the density of the fuel vapor emitted from the fuel tank and introduced into the intake passage direction through the solenoid valve is higher than the density of the fuel vapor desorbed from the canister, the duty cycle of the solenoid valve or the amount of change of the duty cycle is limited to within a prescribed range. By thus limiting the operation of the solenoid valve within a prescribed range, the purge gas amount is limited to within a prescribed range, as a result of which the variation in vapor density caused by the variation of the purge gas amount is suppressed, hence reducing perturbations in air-fuel ratio when performing control to correct the fuel injection amount in accordance with the purge gas amount. Further, by limiting the amount of change of the duty cycle to within a prescribed range, the change of the purge gas amount becomes gradual and stabilized, as a result of which the vapor density is stabilized, ensuring consistent air-fuel ratio when performing control to correct the fuel injection amount in accordance with the purge gas amount.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention will be apparent from the following description with reference to the accompanying drawings, in which:
FIG. 1 is a diagram showing the general construction of an electronically controlled fuel injection-type internal combustion engine equipped with a fuel-vapor treatment apparatus according to one embodiment of the present invention;
FIG. 2 is a simplified flowchart for explaining a basic procedure for engine control operations according to one embodiment of the present invention;
FIGS. 3A, 3B, 3C, and 3D show a simplified flowchart illustrating a procedure for fuel injection amount calculation according to one embodiment of the present invention;
FIGS. 4A and 4B show a flowchart illustrating a procedure for purge control operations according to one embodiment of the present invention;
FIG. 5 is a characteristic diagram showing the relationship between the intake manifold pressure and the full-open purge gas amount;
FIG. 6 is a characteristic diagram showing the relationship between the purge execution time and the maximum target purge ratio;
FIG. 7A is a characteristic diagram showing the relationship between the purge execution time and the maximum/minimum guard value of duty cycle DPG, and FIG. 7B is a characteristic diagram showing the relationship between the purge execution time and the canister vapor adsorption amount;
FIG. 8 is a flowchart illustrating a procedure for a duty cycle limiting operation according to a first embodiment of the present invention;
FIG. 9 is a flowchart illustrating a procedure for a duty cycle limiting operation according to a second embodiment of the present invention;
FIG. 10 is a flowchart illustrating a procedure for a vapor density change detection operation according to a third embodiment of the present invention;
FIG. 11 is a characteristic diagram showing the relationship between the purge execution time and the up guard/down guard value of duty cycle DPG;
FIG. 12 is a flowchart illustrating a procedure for a duty cycle limiting operation according to a fourth embodiment of the present invention;
FIG. 13 is a flowchart illustrating a procedure for a vapor density change detection operation according to a fifth embodiment of the present invention;
FIG. 14 is a flowchart illustrating a procedure for a duty cycle limiting operation according to the fifth embodiment of the present invention; and
FIG. 15 is a diagram showing control according to the present invention by comparison with control according to the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a diagram showing the general construction of an electronically controlled fuel injection-type internal combustion engine equipped with a fuel-vapor treatment apparatus according to one embodiment of the present invention. Air necessary for combustion in the engine 1 is filtered through an air cleaner 2, and introduced through a throttle body 5 into a surge tank (intake manifold) 11 for distribution to an intake pipe 13 for each cylinder. The amount of intake air is measured by an air flow meter 4 and regulated by a throttle valve 7 provided in the throttle body 5. The opening angle of the throttle valve 7 is detected by a throttle angle sensor 9. The intake air temperature is detected by an intake air temperature sensor 3. Further, the intake manifold pressure is detected by a vacuum sensor 12.
On the other hand, the fuel stored in a fuel tank 15 is drawn by a fuel pump 17, passed through a fuel pipe 9, and injected into the intake pipe 13 through a fuel injector valve 21. The air and fuel thus supplied are mixed together in the intake pipe 13, and the mixture is drawn through an intake valve 23 into the cylinder 1, that is, into the engine body. In the cylinder 1, the air/fuel mixture is first compressed by the piston, and then ignited by an igniter or a spark plug and burned, causing a rapid pressure rise and thus producing power.
An ignition distributor 43 is provided with a reference position detection sensor 45 which generates a reference position detection pulse for every 720-degrees of CA rotation of its shaft measured in degrees of crankshaft angle (CA), and a crankshaft angle sensor 47 which generates a position detection pulse for every 30-degrees of CA. The engine 1 is cooled by a coolant introduced into a coolant passage 49, and the coolant temperature is detected by a coolant temperature sensor 51.
The burned air/fuel mixture is discharged as exhaust gas into an exhaust manifold 27 through an exhaust valve 25, and introduced into an exhaust pipe 29. The exhaust pipe 29 holds an O 2 sensor 31 for detecting oxygen concentration in the exhaust gas. The exhaust system further downstream holds a catalytic converter 33 which contains a three-way catalyst that promotes the oxidation of unburned constituents in the exhaust gas and the reduction of nitrogen oxides at the same time. The exhaust gas thus purified in the catalytic converter 33 is discharged into the atmosphere.
The illustrated internal combustion engine is also equipped with a canister 37 containing activated charcoal (adsorbent) 36. The canister 37 has a fuel vapor chamber 38a and an air chamber 38b disposed opposite each other on either side of the activated charcoal 36. The fuel vapor chamber 38a communicates at one end with the fuel tank 15 through a vapor collector pipe 35, and at the other end with the surge tank 11, located in the intake passage downstream of the throttle valve 7, through a purge passage 39. Installed in the purge passage 39 is a solenoid valve 41 for controlling the purge gas amount. In this construction, fuel vapor emitted from the fuel tank 15 is introduced through the vapor collector pipe 35 into the canister 37 where the vapor is temporarily stored by being adsorbed onto the activated charcoal (adsorbent) 36 contained therein. When the solenoid valve 41 is opened, vacuum in the intake manifold causes air in the air chamber 38b to be drawn through the activated charcoal 36 into the purge passage 39. When the air passes through the activated charcoal 36, the fuel vapor adsorbed on the activated charcoal 36 is desorbed. In this way, the air is mixed with the fuel vapor, and the resulting vapor is introduced through the purge passage 39 into the surge tank 11 and mixed with the fuel injected through the fuel injector valve 21 for use as fuel in the cylinder 1. Not only the vapor temporarily stored on the activated charcoal is introduced into the purge passage 39, as described above, but vapor is also drawn into the purge passage 39 directly from the fuel tank 15.
An engine electronic control unit (engine ECU) 60 is also shown and is a microcomputer system that performs control operations, such as fuel injection control described in detail later and ignition timing control for sending an ignition signal to the igniter after determining optimum ignition timing by comprehensively judging the engine condition based on engine rpm and on the signals from various sensors. The signals from the various sensors are input via an A/D conversion circuit 64 or via an input interface circuit 65 to a CPU 61 which, in accordance with programs stored in a ROM 62, performs operations using the input signals, and based on the results of the operations, outputs control signals for various actuators via an output interface circuit 66. A RAM 63 is used to temporarily store data during the operation and control processes. These constituent parts of the ECU are interconnected by a system bus 69 (which consists of an address bus, a data bus, and a control bus).
The engine ECU 60 operates by looping through instructions in accordance with a base routine, and during the execution of the base routine, services interrupts to carry out operations synchronized with input signal changes, engine revolutions, or time. More specifically, as shown in FIG. 2, when power is turned on, the engine ECU 60 performs a prescribed initialization (step 102), after which sensor signal/switch signal input (step 104), engine rpm calculation (step 106), fuel injection amount calculation (step 108), ignition timing calculation (step 110), idle rpm calculation (step 112), and self-diagnosis (step 114) are repeated in a loop. Signals output from the A/D conversion circuit (ADC) or some of the sensors or switches are handled as interrupts requesting servicing (step 122). Further, since the results of the fuel injection amount or ignition timing calculation must be supplied to the appropriate actuator with optimum timing synchronized with engine revolution, these are serviced as interrupts caused by signals from the crankshaft angle sensor (steps 132, 134). Other processing that needs to be carried out at predetermined intervals of time is carried out using a timer interrupt routine.
Basically, fuel injection control involves calculating the fuel injection amount, that is, the time the fuel injector valve 21 is open, from the intake air amount measured by the air flow meter 4 and the engine rpm obtained from the crankshaft angle sensor 47, and the thus calculated amount of fuel is injected when a prescribed crankshaft angle is reached. In the above calculation, corrections are made, such as basic corrections based on signals from the throttle angle sensor 9, the coolant temperature sensor 51, the intake air temperature sensor 3, etc., an air-fuel ratio feedback correction based on a signal from the O 2 sensor 31, an air-fuel ratio learning correction to bring the median of the feedback correction value to stoichiometry, and a correction based on canister purge. The present invention is concerned, in particular, with canister purge and fuel injection amount corrections based on canister purge. The following describes in detail a fuel injection amount calculation routine (which corresponds to step 108 in the base routine) and a purge control routine (which is initiated by a timer interrupt) which implement the fuel-vapor control according to the present invention.
FIG. 3A to 3D show a simplified flowchart illustrating a procedure for fuel injection amount calculation according to one embodiment of the invention. The fuel injection amount calculation routine shown consists of air-fuel ratio (A/F) feedback (F/B) control (FIG. 3A), A/F learning control (FIG. 3B), vapor density learning control (FIG. 3C), and fuel injection time (TAU) calculation control (FIG. 3D). F/B control will be described to start with.
In F/B control, first a decision is made as to whether all of the following F/B conditions are satisfied (step 202).
(1) Not during engine crank.
(2) Not during fuel cutoff (F/C).
(3) Coolant temperature ≧40° C.
(4) Activation of A/F sensor (O 2 sensor) completed.
If the answer to the decision is YES, then a decision is made as to whether the air-fuel mixture (A/F) is rich, that is, whether the output voltage of the O 2 sensor 31 is lower than a reference voltage (for example, 0.45 V) (step 208).
If the answer to the decision in step 208 is YES, that is, if A/F is rich, then a decision is made as to whether A/F was also rich in the previous cycle, by checking whether an air-fuel rich flag XOX is 1 or not (step 210). If the answer to the decision is NO, that is, if A/F was lean in the previous cycle and has changed to rich in the current cycle, a skip flag XSKIP is set to 1 (step 212), a mean FAFAV between the air-fuel ratio feedback correction coefficient FAF immediately before the previous skip and the FAF immediately before the current skip is calculated (step 214), and the air-fuel ratio feedback correction coefficient FAF is decreased by a predetermined skip amount RSL (step 216). On the other hand, if the answer to the decision in step 210 is YES, that is, if A/F was also rich in the previous cycle, the air-fuel ratio feedback correction coefficient FAF is decreased by a predetermined integrated amount KIL (step 218). After carrying out step 216 or 218, the air-fuel rich flag XOX is set to 1 (step 220), F/B control is terminated, and the process proceeds to the next A/F learning control (step 302).
On the other hand, if the answer to the decision in step 208 is NO, that is, if A/F is lean, then a decision is made as to whether A/F was also lean in the previous cycle, by checking whether the air-fuel rich flag XOX is 0 or not (step 222). If the answer to the decision is NO, that is, if A/F was rich in the previous cycle and has changed to lean in the current cycle, the skip flag XSKIP is set to 1 (step 224), a mean FAFAV between the air-fuel ratio feedback correction coefficient FAF immediately before the previous skip and the FAF immediately before the current skip is calculated (step 226), and the air-fuel ratio feedback correction coefficient FAF is increased by a predetermined skip amount RSR (step 228). On the other hand, if the answer to the decision in step 222 is YES, that is, if A/F was also lean in the previous cycle, the air-fuel ratio feedback correction coefficient FAF is increased by a predetermined integrated amount KIR (step 230). After carrying out step 228 or 230, the air-fuel rich flag XOX is set to 0 (step 232), F/B control is terminated, and the process proceeds to the next A/F learning control (step 302).
In the above process, if the answer to the decision in step 202 is NO, that is, if the F/B conditions are not satisfied, then FAFAV and FAF are each set to a reference value 1.0 (steps 204, 206), F/B control is terminated, and the process proceeds to the next A/F learning control (step 302).
Next, A/F learning control (FIG. 3B) will be described. First, computation is made based on the current intake manifold pressure to determine the current A/F learning region j (j=1 to 7) out of seven A/F learning regions 1 to 7 classified by intake manifold pressure, and the determined region is denoted by tj (j=1 to 7) (step 302). Here, the intake manifold pressure is detected by the vacuum sensor 12. Next, a decision is made as to whether the current learning region tj coincides with the previous learning region j (step 304). If they do not coincide, that is, if the learning region has changed, the current learning region tj is substituted for j (step 306), a skip count CSKIP is cleared (step 310), and A/F learning control is terminated, after which the process proceeds to vapor density learning control (step 402).
On the other hand, if the answer to the decision in step 304 is YES, that is, if the current learning region coincides with the previous learning region, then a decision is made as to whether all the following A/F learning conditions are satisfied (step 308).
(1) Air-fuel ratio F/B in progress.
(2) No increase after engine start and no increase for engine warmup.
(3) Coolant temperature ≧80° C.
If they are not satisfied, the skip count CSKIP is cleared (step 310), A/F learning control is terminated, and the process proceeds to vapor density learning control (step 402).
If the answer to the decision in step 308 is YES, that is, if the A/F learning conditions are satisfied, then a decision is made as to whether the skip flag XSKIP is 1, that is, whether there was a skip immediately before that (step 312). If the answer to the decision is NO, that is, if there was no skip immediately before that, then A/F learning control is terminated and the process proceeds to vapor density learning control (step 402). On the other hand, if the answer is YES, that is, if there was a skip immediately before that, the skip flag XSKIP is cleared to 0 (step 314) and the skip count CSKIP is incremented (step 316). Then, a decision is made as to whether the incremented skip count CSKIP has reached a predetermined value KCSKIP (for example, 3) (step 318). If the answer is NO, A/F learning control is terminated and the process proceeds to vapor density learning control (step 402).
On the other hand, if the answer to the decision in step 318 is YES, then a decision is made as to whether the purge ratio PGR calculated by the purge control routine described later is 0 or not (step 320). If the answer is NO, that is, if purge is currently being performed, A/F learning control is terminated and the process proceeds to vapor density learning control (step 410). On the other hand, if PGR is 0, that is, if purge is not being performed, a learning value KGj (j=1 to 7) for the current learning region j is changed, according to the result of the comparison between the deviation of the FAFAV set in step 204, 214, or 226 in F/B control and a predetermined value (for example, 2%). That is, if FAFAV is equal to or greater than 1.02 (YES in step 322), the learning value KGj is increased by a predetermined value x (step 324); if FAFAV is less than 0.98 (YES in step 326), the learning value KGj is decreased by the predetermined value x (step 328). In other cases, an A/F learning end flag XKGj for the current learning region j is set to 1 (step 330). After A/F learning control is thus terminated, the process proceeds to vapor density learning control (step 402).
Next, vapor density learning control (FIG. 3C) will be described. First, in step 402, a decision is made as to whether the engine is being cranked. If the engine is not being cranked, vapor density learning control is terminated and the process proceeds to TAU calculation control (step 452). If the engine is being cranked, the vapor density is set to the reference value 1.0, while clearing a vapor density update count CFGPG to 0 (step 404). Next, other initialization processing is carried out (step 406), to terminate vapor density learning control.
In A/F learning control, if the answer to the decision in step 320 is NO, that is, if the A/F learning conditions are satisfied, and if a purge operation is in progress, the process proceeds to step 410 in vapor density learning control, where a decision is made as to whether or not the purge ratio PGR is greater than or equal to a predetermined value (for example, 0.5%). If the answer to the decision is YES, then a decision is made as to whether or not FAFAV is within a predetermined value (±2%) with respect to the reference value 1.0 (step 412). If FAFAV is within such a range, a purge density update value tFG per purge ratio is set to 0 (step 414); if not within such a range, the vapor density update value tFG per purge ratio is calculated from the following equation (step 416).
tFG←(1-FAFAV)/(PGR*a)
where a=constant (for example, 2) Next, the vapor density update counter CFGPG is incremented (step 418), and the process proceeds to step 428.
If the answer to the decision in step 410 is NO, that is, if the purge ratio PGR is smaller than 0.5%, this means that the vapor density update accuracy is not good; therefore, the deviation of the air-fuel ratio feedback correction coefficient FAF is examined (to determine, for example, whether or not the deviation is outside ±10% of the reference value 1.0). If FAF is larger than 1.1 (YES in step 420), the vapor density update value tFG is decreased by a predetermined value Y (step 422); if FAF is smaller than 0.9 (YES in step 424), the vapor density update value tFG is increased by the predetermined value Y (step 426). Finally, in step 428, the vapor density FGPG is corrected by the vapor density update value tFG obtained in the above process, after which vapor density learning control is terminated and the process proceeds to TAU calculation control (step 452).
Next, TAU (fuel injection time) calculation control (FIG. 3D) will be described. First, by referencing data stored as a map in the ROM 62, a basic fuel injection time TP is obtained based on engine rpm and engine load (intake air amount per engine revolution), and also, a basic correction coefficient FW is calculated based on signals from various sensors such as the throttle angle sensor 9, the coolant temperature sensor 51, and the intake air temperature sensor 3 (step 452). Here, the engine load may be estimated using the intake manifold pressure and engine rpm. Next, an A/F learning correction amount KGX appropriate to the current intake manifold pressure is calculated by interpolation from the A/F learning value KGj of an adjacent learning region (step 454).
Next, using the vapor density FGPG and the purge ratio PGR, a purge A/F correction amount FPG is calculated from the following equation (step 456).
FPG←(FGPG-1)*PGR
Finally, the fuel injection time TAU is calculated from the following equation (step 458).
TAU←TP*FW*(FAF+KGX+FPG)
This completes the fuel injection amount calculation routine.
FIGS. 4A and 4B show a simplified flowchart illustrating a procedure for purge control operations according to one embodiment of the present invention. The purge control routine shown here is initiated by a timer interrupt that occurs at prescribed intervals of time (for example, 1 ms); in this routine, the duty cycle (the ratio of pulse ON time to pulse spacing) of a pulse signal used to control the operation of the D-VSV (purge gas amount control solenoid) 41 is determined, and using this pulse signal, the energization of the D-VSV is controlled. This routine consists of purge ratio (PGR) calculation control (FIG. 4A) and D-VSV energization control (FIG. 4B). First, purge ratio calculation control will be described.
In purge ratio calculation control (FIG. 4A), first a decision is made as to whether the execution of this routine coincides with a period in which the solenoid valve control pulse signal can be turned on, that is, whether it matches a prescribed duty period (for example, 100 ms) (step 502). If it matches the duty period, then a decision is made as to whether purge condition 1 is satisfied, that is, whether all the A/F learning conditions except the condition "Not during fuel cutoff" are satisfied (step 504). If purge condition 1 is satisfied, then a decision is made as to whether purge condition 2 is satisfied, that is, the fuel is not cut off and the A/F learning end flag XKGj is set to 1 (step 506).
If purge condition 2 also is satisfied, a purge execution timer CPGR is incremented (step 512). Then, by referencing the map shown in FIG. 5 (stored in the ROM 62) using the current intake manifold pressure as the key, a purge gas amount PGQ at full-open VSV is obtained, and a ratio between the purge gas amount PGQ and the intake air amount QA is calculated to determine the purge ratio PG100 at full-open VSV (step 514). Next, a decision is made as to whether or not the air-fuel ratio feedback correction coefficient FAF is inside predetermined limits (greater than a constant KFAF85 but smaller than a constant KFAF15) (step 516).
If the answer to the decision in step 516 is YES, a target purge ratio tPGR is increased by a predetermined amount KPGRu, while controlling the obtained tPGR within the maximum target purge ratio P% (obtained from the map shown in FIG. 6) determined based on the purge execution time CPGR (step 518). On the other hand, if the answer to the decision in step 516 is NO, the target purge ratio tPGR is lowered by a predetermined value KPGRd, while controlling the obtained tPGR, in a similar manner to that in step 518, so that it does not become smaller than a minimum target purge ratio s% (step 520). In this way, A/F perturbations associated with purge operations are prevented.
Next, based on the target purge ratio tPGR and the purge ratio PG100 at full-open VSV, the duty cycle DPG is calculated from the following equation (step 522).
DPG←(tPGR/PG100)*100
Then, a duty cycle limiting operation, which constitutes a feature of the present invention, is performed on the thus obtained duty cycle DPG (step 524). The first to fifth embodiments of this DPG limiting operation will be described in detail later.
Next, taking into account a case where DPG is updated as a result of the DPG limiting operation in step 524, the actual purge ratio PGR is calculated from the following equation (step 526).
PGR←PG100*(DPG/100)
Finally, based on the duty cycle DPG and purge ratio PGR obtained in the above process, DPGO and PGRO for "remembering" the previous duty cycle and purge ratio are updated (step 528), and the process proceeds to step 602 in D-VSV energization control.
On the other hand, if, in step 502, a decision is made that the execution of the routine does not match the duty period, the process proceeds to step 606 in D-VSV energization control. Further, if the execution does match the duty period, but if purge condition 1 is not satisfied in step 504, the corresponding RAM is initialized (step 508), duty cycle DPG and purge ratio PGR are both cleared to 0 (step 510), and the process proceeds to step 608 in D-VSV energization control. Also, if purge condition 2 is not satisfied in step 506, the duty cycle DPG and purge ratio PGR are both cleared to 0 (step 510), and the process proceeds to step 608 in D-VSV energization control.
Next, D-VSV energization control (FIG. 4B) will be described. First, in step 602, which is performed following step 528 in purge ratio control, VSV is energized. Next, in step 604, VSV deenergization time TDPG is obtained from the following equation, and the process is terminated.
TDPG←DPG+TIMER
where TIMER is the value of a counter which is incremented for every execution cycle of the purge control routine.
In step 606, which is performed when the answer to the decision in step 502 is NO, a decision is made as to whether the current TIMER value coincides with the VSV deenergization time TDPG. If it does not coincide, the process is terminated; if it coincides, the process proceeds to step 608. In step 608, which is performed following step 510 or step 606, VSV is deenergized, and the process is terminated. The purge control routine is thus completed.
The duty cycle limiting operation (step 524) in the purge control routine (FIG. 4A) will now be described in detail below. As earlier described, the present invention is intended to suppress the phenomenon that when the density of the vapor emitted into the purge passage directly from the fuel tank is higher than that of the vapor from the canister, in other words, when the tank vapor has a greater contribution to the resulting vapor density, if the amount of purge gas is varied, the vapor density is caused to vary, hence causing large perturbations in the A/F. In the five embodiments hereinafter given, the criteria used in making a decision that the tank vapor has the greater contribution are described and, when such a decision is made, how the purge gas amount, that is, the duty cycle of the pulse signal to the solenoid valve, is actually limited is described.
First, a description is given of the first embodiment. In the first embodiment, the decision about whether the tank vapor amount is large or not is made based on the purge execution time, and an upper limit or a lower limit, or both, are imposed on the duty cycle. That is, as shown in FIG. 7B, the canister vapor adsorption amount decreases as the purge execution time increases, and the canister, if fully loaded first, will be emptied in about 20 to 30 minutes. Then, as shown in FIG. 7A, after a predetermined purge execution time has elapsed, the duty cycle DPG is limited using a maximum guard value MAXDPG and/or a minimum guard value MINDPG.
More specifically, a map such as the one shown in FIG. 7A is stored in advance in the ROM 62, and the DPG limiting operation shown in FIG. 8 is carried out. In the flowchart shown here, both the upper and lower limits are imposed, but one or other of the upper or lower limit may be used. First, by referencing the map using the current purge execution time as the key, the maximum guard value MAXDPG is obtained (step 702). Next, a decision is made as to whether or not the duty cycle DPG calculated in step 522 (FIG. 4A) is greater than or equal to MAXDPG (step 704). If the answer to the decision is YES, MAXDPG is substituted for DPG (step 706). On the other hand, if the answer is NO, the minimum guard value MINDPG is obtained in a similar way (step 708), and a decision is made as to whether or not the duty cycle DPG is smaller than or equal to MINDPG (step 710). If the answer to the decision is YES, MINDPG is substituted for DPG (step 712). If the answer to the decision is NO in both steps 704 and 710, the canister purge is allowed to be performed without imposing any limits.
As the purge execution time passes, the canister purge progresses and the contribution from the tank vapor increases. However, in this limiting operation, as the purge execution time increases, the upper limit of the duty cycle is lowered to suppress the increase in the amount of purge gas from the canister. This suppresses the change in vapor density that may occur during a transition from idling to driving (in the increasing direction of the purge gas amount), and improves the precision of A/F correction, the result being to suppress A/F perturbations. Furthermore, as the purge execution time increases, the lower limit of the duty cycle is raised to suppress the decrease in the amount of purge gas from the canister. This suppresses the change in vapor density that may occur during a transition from driving to idling (in the decreasing direction of the purge gas amount), and improves the precision of A/F correction, the resulting effect being to suppress A/F perturbations. By controlling both the upper and lower limits, A/F perturbations can be further suppressed. In any case, since priority is given to canister purge during early stages of the purge, there occurs no decrease in the adsorption ability of the canister.
Next, the second embodiment will be described. In the second embodiment, sensors are provided that directly detect whether or not the amount of vapor from the fuel tank is large, and as in the first embodiment, the upper limit or lower limit of the duty cycle, or both, are controlled. An increase in the amount of vapor from the fuel tank occurs, for example, when the tank fuel temperature is high, or when the tank internal pressure is high. Therefore, sensors are provided that directly detect these variables, and output signals from these sensors are input, for example, in step 104 in the base routine shown in FIG. 2; then, when it is decided that the tank vapor amount is large, a flag XTNK indicating that occurrence is set. Then, based on the flag XTNK, the duty cycle (DPG) limiting operation shown in FIG. 9 is carried out. First, a decision is made as to whether XTNK is 1 or not (step 802), and if the answer to the decision is YES, DPG is limited using a prescribed maximum guard value KMAXDPG and minimum guard value KMINDPG (steps 804 to 810).
In the second embodiment, since an increase in the tank vapor is directly detected, as described above, control precision is improved, and unlike the first embodiment, a situation does not occur where a prescribed time has to pass if the engine is started when the canister vapor adsorption amount is small.
Next, the third embodiment will be described. In the third embodiment, a decision is made, based on the change of vapor density, as to whether the tank vapor amount is large, and based on the result of the decision, the upper limit or lower limit of the duty cycle, or both, are controlled. Further, the maximum guard value and the minimum guard value are controlled in multiple steps according to the mode of the vapor density change, thereby aiming at accomplishing the promotion of purging and the suppression of A/F perturbations at the same time.
More specifically, the vapor density change detection process shown in FIG. 10 is added to the end (after step 428) of the vapor density learning control (FIG. 3C). In this process, first a decision is made as to whether a vapor update count CFGPG has reached a prescribed count a (step 902). The prescribed count a represents the number of times (for example, 10) required to complete the vapor density learning in the early period of the purge. Alternatively, the decision may be made based on the purge execution time. If the answer to the decision in step 902 is YES, then a decision is made as to whether the engine is idling, that is, whether a flag XIDL indicating an idling condition is set to 1 (step 904). If the engine is idling, a decision is made as to whether or not the vapor density update value tFG is less than or equal to a predetermined value -KFGTNK (for example, -3%), that is, whether the vapor density update value tFG has been increased toward the rich side. If the answer to the decision is YES, then a decision is made as to whether the tank vapor large flag XTNK is 1, that is, whether the flag is already set (step 910). If the answer to the decision in step 910 is NO, that is, if it is decided for the first time that the tank vapor amount is large, then the flag is set to 1 (step 912), and a predetermined value b is substituted for the minimum guard value KMINDPG and a predetermined value c for the maximum guard value KMAXDPG (step 914). On the other hand, if the answer to the decision in step 910 is YES, that is, if it is decided that the tank vapor amount is already large, d is substituted for the minimum guard value KMINDPG and e for the maximum guard value KMAXDPG, where d and e are predetermined values such that d>b and e<c (step 916). This means that, except when the tank vapor amount is judged as being large for the first time, severe limits are imposed, that is, the upper and lower limits are set in multiple steps. The flag XTNK is reset in the initialization operation (step 102 in FIG. 2), and after it has been set as described above, there is no need to reset it.
The DPG limiting operation is performed using the thus set flag XTNK, maximum guard value KMAXDPG, and minimum guard value KMINDPG. The operating procedure is the same as that of the second embodiment illustrated in the flowchart of FIG. 9, and therefore, will not be repeated here.
In the third embodiment, since the decision on whether the tank vapor amount is large or not is made based on the detection of a change in the vapor density, as described above, sensors such as a tank pressure detection sensor, as required in the second embodiment, need not be provided. Furthermore, since the upper and lower limits of the duty cycle DPG are set in multiple steps each time the amount of generated vapor, and hence the vapor density, changes beyond a predetermined limit, A/F perturbations caused by the canister purge and the tank vapor can be prevented in an appropriate manner.
Next, the fourth embodiment will be described. In the fourth embodiment, as in the first embodiment, the decision on whether the tank vapor amount is large or not is made based on the purge execution time, but unlike the first embodiment, the fourth embodiment is intended to limit the amount of increase or the amount of decrease, or both, of the duty cycle DPG with respect to the previous duty cycle DPGO (calculated in step 528 in FIG. 4A). More specifically, a map defining a DPG up guard value UPDPG and/or a DPG down guard value DNDPG, both decreasing with increasing purge execution time, such as the one shown in FIG. 11, is provided, and using this map, the DPG limiting operation shown in FIG. 12 is carried out.
First, a decision is made as to whether the DPG calculated in the current process is on the upper side or lower side of the previously calculated DPGO (step 1002). If it is on the upper side of the previous value, the DPG up guard value UPDPG is obtained by referencing the map of FIG. 11 using the current purge execution time as the key (step 1004). Next, the thus obtained UPDPG is added to the DPGO calculated in step 528, and the result is taken as DPG guard value tDPG (step 1006). Then, the current DPG is compared with tDPG (step 1008), and if the current DPG is larger than or equal to tDPG, DPG is replaced by tDPG (step 1010). On the other hand, if it is decided in step 1002 that the current DPG is smaller than the previous value, the DPG down guard value DNDPG is obtained by referencing the map of FIG. 11 using the current purge execution time as the key (step 1014). Next, DNDPG is subtracted from the DPGO calculated in step 528, and the result is taken as the DPG guard value tDPG (step 1016). Then, the current DPG is compared with tDPG (step 1018), and if the current DPG is smaller than or equal to tDPG, DPG is replaced by tDPG (step 1010).
In this manner, as the purge execution time increases, the allowable amount of increase of the duty cycle DPG is reduced, thereby reducing the rate at which the purge gas amount can increase from the previous value. This has the effect of stabilizing the vapor density during a transition from idling to driving (in the increasing direction of the purge gas amount). Further, as the purge execution time increases, the allowable amount of decrease of the duty cycle DPG is reduced, thereby reducing the rate at which the purge gas amount can decrease from the previous value. This has the effect of stabilizing the vapor density during a transition from driving to idling (in the decreasing direction of the purge gas amount). In either case, the effect can be further enhanced by combining the above control with the upper or lower limit control means described in the first embodiment.
Next, the fifth embodiment will be described. In the fifth embodiment, as in the third embodiment, the decision on whether the tank vapor amount is large or not is made based on the change of the vapor density, and like the fourth embodiment, the fifth embodiment is also intended to control the amount of increase or the amount of decrease, or both, of the duty cycle DPG with respect to the previous duty cycle DPGO. In the fifth embodiment, however, the DPG up guard value and the DPG down guard value are each controlled in multiple steps according to the mode of the vapor density change.
More specifically, as in the third embodiment, the vapor density change detection process shown in FIG. 13 is added to the end (after step 428) of the vapor density learning control (FIG. 3C). In the process shown in FIG. 13, steps 1114 and 1116 are different from the corresponding steps shown in FIG. 10, with KMAXDPG and KMINDPG in FIG. 10 replaced by an up guard value KUPDPG and a down guard value KDNDPG, respectively. Otherwise, the process is identical to that shown in FIG. 10, and therefore, detailed description of the process will not be given here. It will be noted, however, that, like the third embodiment, constants f, g, h, and i are so set as to reduce the amount of change, i.e. the amount of increase or the amount of decrease, to a greater extent when a change in the vapor density is detected successively than when the change is detected for the first time.
The procedure for the DPG limiting operation according to the fifth embodiment is illustrated in the flowchart of FIG. 14. First, a decision is made as to whether XTNK is 1 or not (step 1202); if the answer to the decision is YES, the amount of increase and the amount of decrease are limited (step 1204 to 1210), using the up guard value KUPDPG and down guard value KDNDPG obtained in the process of. FIG. 13. The procedure for such a change amount limiting operation is similar to the procedure of the fourth embodiment illustrated in FIG. 12, and therefore, no further explanation is necessary.
As described, in the fifth embodiment, the decision on whether the tank vapor amount is large or not is made by detecting the change of the vapor density, and based on the result of the decision, the allowable amount of increase or decrease of the duty cycle DPG is reduced, thereby reducing the rate at which the purge gas amount can increase or decrease from the previous value. This has the effect of stabilizing the vapor density and suppressing A/F perturbations.
FIG. 15 shows the control according to the present invention in comparison with the prior art control. In the case of the prior art purge-ratio-constant control, during idling when the intake air amount (hence, the fuel injection amount) is small, the tank vapor contribution (the ratio of the tank vapor amount to the fuel injection amount) is large and the degree of richness is overestimated and during driving when the intake air amount is large, the tank vapor contribution is small and the degree of richness is under-estimated. Accordingly, immediately after an idle-to-driving transition, since the A/F correction is made based on the vapor density during idling, the fuel increase correction is insufficient, resulting in acceleration enleanment. Conversely, immediately after a driving-to-idling transition, since the A/F correction is made based on the vapor density during driving, fuel decrease correction is insufficient, resulting in deceleration enrichment. This impairs drivability, etc.
On the other hand, in the case of the control according to the present invention, during a transition from idling to driving (in the increasing direction of the purge gas amount), the upper limit of the purge gas amount is lowered to suppress the change in the vapor density. This improves the precision of the A/F correction and hence contributes to suppressing A/F perturbations. Also, during a transition from driving to idling (in the decreasing direction of the purge gas amount), the lower limit of the purge gas amount is raised to suppress the change of the vapor density. This improves the precision of the A/F correction and hence contributes to suppressing A/F perturbations.
Although the preferred embodiments of the present invention have been described above, it will be appreciated that the invention is not limited to the illustrated embodiments. Rather, it will be easy for those skilled in the art to devise various other embodiments.
As described above, according to the present invention, when the density of the fuel vapor emitted from the fuel tank and introduced into the intake passage directly through the solenoid valve is higher than the density of the fuel vapor desorbed from the canister, the duty cycle of the solenoid valve or the amount of change of the duty cycle is limited to within a prescribed range; as a result, the change of the vapor density associated with the change in the purge gas amount is suppressed, or the change in the purge gas amount becomes less. This has the effect of stabilizing the vapor density and hence preventing perturbations in air-fuel ratio when performing control to correct the fuel injection amount in accordance with the purge gas amount. | A fuel-vapor treatment method and apparatus for an internal combustion engine, wherein when the density of fuel vapor emitted directly from a fuel tank is higher than the density of fuel vapor emitted from a canister, provisions are made to prevent the density of the mixture of these vapors purged into an intake passage from varying substantially, thereby suppressing perturbations in air-fuel ratio. When purge execution time becomes long, the energization of a solenoid valve used to control the amount of purge gas from the canister is limited to keep the maximum/minimum amount of purge gas or the amount of change thereof within a prescribed range. This serves to suppress the variation in purge gas amount, and hence the variation in vapor density, that may occur during a transition from idling to driving (in the increasing direction of the purge gas amount) or during a transition from driving to idling (in the decreasing direction of the purge gas amount). | 5 |
FIELD OF THE INVENTION
The invention relates to methods for making chiral phosphorus ligands including chiral phosphines, chiral phosphine oxides, phosphonamides, and aminophosphines. The chiral phosphorus ligands prepared by the methods of the invention are useful as components of chiral catalysts, e.g., transition metal complexes.
BACKGROUND OF THE INVENTION
Chiral phosphine ligands have been widely used as components of transition metal catalyts, which catalysts are useful for carrying out asymmetric synthesis. Although many methods for making chiral phosphines are known, the chiralities of most of these ligands rely mainly on a chiral substituent group to impart chirality to the resulting phosphine ligand. In contrast, only a limited number of P-chiral ligands have been prepared, presumably because no general and efficient methods are available for their synthesis.
In the 1970s Knowles and coworkers prepared the first prominent P-chiral ligand DIPAMP (see, e.g., reviews by Methot, J. L. et al. Adv. Synth. Catal. 2004, 346, 1035-1050; Seayad, J. et al., Org. Biomol. Chem. 2005, 3, 719-724; Connon, S. J. Angew. Chem., Int. Ed. 2006, 45, 3909-3912; and Benaglia, M. et al. Org. Biomol. Chem. 2010, 8, 3824-3830). However, methods for the synthesis of optically active P-chiral phosphines have emerged slowly. Representative methods include the formation and separation of diastereomeric mixtures of menthyl phosphinates, auxiliary-based transformations, enantioselective deprotonation of phosphine-boranes and sulfides, enzymatic resolution, transition metal catalyzed asymmetric phosphine alkylations, dynamic kinetic asymmetric oxidation of racemic phosphines, and through H-menthylphosphinates. Despite these elegant approaches, the currently available methods are often limited in terms of substrate scope and practicality, especially for the synthesis of sterically crowded P-chiral phosphines.
Thus, there is a need to provide a general, practical, and high stereoselective method for the synthesis of P-chiral compounds with diverse structures and functionalities.
BRIEF SUMMARY OF THE INVENTION
In its broadest embodiment, the invention relates to a method of making the compound of formula (I):
the method comprising allowing a compound of formula (IIa) or (IIb):
to react with a first organometallic reagent of formula M 1 -R 1 followed by reaction with a second organometallic reagent of formula M 2 -R 2 to provide the compound of formula (I); wherein
ring A of the compound of formula (IIa) represents a 5- to 7-membered heterocyclic ring optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, —CF 3 , —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl;
ring B of the compound of formula (IIb) represents a (C 6 -C 10 )aryl or a (5 to 11-membered)heteroaryl; wherein each of said (C 6 -C 10 )aryl and (5 to 11-membered)heteroaryl of said B ring is optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, and —CF 3 ;
R 1 , R 2 and R 3 represent different groups, wherein;
R 1 is selected from —(C 1 -C 6 )alkyl, —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl; wherein each of said —(C 1 -C 6 )alkyl, —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl of said R 1 group is optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, —CF 3 , dioxolanyl, and phenyl optionally substituted with 1 to 3 R 7 groups;
each R 2 is independently selected from hydrogen, —(C 1 -C 6 )alkyl, —(C 2 -C 6 )alkenyl, —(C 2 -C 6 )alkynyl, —(C 3 -C 6 )cycloalkyl, -(5 to 11-membered)heterocyclyl, —(C 6 -C 10 )aryl, -(5 to 11-membered)heteroaryl, —N(R 2a ) 2 , and ferrocenyl; wherein each of said —(C 1 -C 6 )alkyl, —(C 2 -C 6 )alkenyl, —(C 2 -C 6 )alkynyl, —(C 3 -C 6 )cycloalkyl, -(5 to 11-membered)heterocyclyl, —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl of said R 2 group is optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, —CF 3 , and phenyl optionally substituted with 1 to 3 R 8 groups;
each R 2a is independently selected from —(C 1 -C 6 )alkyl, —(C 2 -C 6 )alkenyl, —(C 2 -C 6 )alkynyl, —(C 3 -C 6 )cycloalkyl, -(5 to 11-membered)heterocyclyl, —(C 6 -C 10 )aryl, -(5 to 11-membered)heteroaryl, wherein each of said —(C 1 -C 6 )alkyl, —(C 2 -C 6 )alkenyl, —(C 2 -C 6 )alkynyl, —(C 3 -C 6 )cycloalkyl, -(5 to 11-membered)heterocyclyl, —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl of said R 2a group is optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, —CF 3 , and phenyl optionally substituted with 1 to 3 R 8 groups;
R 3 is selected from —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl; wherein each of said —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl of said R 3 group is optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, and —CF 3 , and phenyl optionally substituted with 1 to 3 R 9 groups;
R 4 is selected from (C 1 -C 6 )alkyl, —(C 3 -C 6 )cycloalkyl, -(5 to 11-membered)heterocyclyl, —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl; wherein each of said —(C 1 -C 6 )alkyl, —(C 2 -C 6 )alkenyl, —(C 2 -C 6 )alkynyl, —(C 3 -C 6 )cycloalkyl, -(5 to 11-membered)heterocyclyl, —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl of said R 4 group is optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, —CF 3 , and phenyl, or
R 4 is selected from phenylsulfonyl, pyridinylsulfonyl, and pyrimidinylsulfonyl; wherein each of said phenylsulfonyl, pyridinylsulfonyl, and pyrimidinylsulfonyl of said R 4 group is optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, and —CF 3 ; R 5 and R 6 are each independently selected from hydrogen, —(C 1 -C 6 )alkyl, —CF 3 , —(C 3 -C 6 )cycloalkyl, -(5 to 11-membered)heterocyclyl, —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl; wherein each of said —(C 1 -C 6 )alkyl, —(C 3 -C 6 )cycloalkyl, -(5 to 11-membered)heterocyclyl, —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl of said R 5 and R 6 is optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, and —CF 3 ;
R 7 , R 8 and R 9 are each independently selected from —(C 1 -C 6 )alkyl, —CF 3 , —(C 3 -C 6 )cycloalkyl, -(5 to 11-membered)heterocyclyl, —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl; wherein each of said —(C 1 -C 6 )alkyl, —(C 3 -C 6 )cycloalkyl, -(5 to 11-membered)heterocyclyl, —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl of said R 7 , R 8 and R 9 groups are each independently substituted by 1 to 3 groups selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, —CF 3 , and 1,3-dioxolanyl;
X 1 is selected from O, S, BH 3 or an electron pair;
M 1 and M 2 are each independently Li, MgX 2 or ZnX 2 ;
X 2 is selected from F, Cl, Br, and I; and
j is 0, 1 or 2.
In a second embodiment (embodiment 2), the invention relates to a method for making the compound of formula (I), wherein X 1 is O.
In a third embodiment (embodiment 3), the invention relates to a method for making the compound of formula (I) according to embodiment 1, wherein X 1 is an electron pair.
In a fourth embodiment (embodiment 4), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 1 to 3, wherein R 3 is phenyl.
In a fifth embodiment (embodiment 5), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 1 to 4, wherein R 1 is —(C 6 -C 10 )aryl; wherein said —(C 6 -C 10 )aryl is substituted by 1 to 3 substituents independently selected —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, dioxolanyl, and 1,3-dimethoxyphenyl.
In a sixth embodiment (embodiment 6), the invention relates to a method for making the compound of formula (I) according to any of one of embodiments 1 to 4, wherein R 1 is —(C 1 -C 6 )alkyl.
In a seventh embodiment (embodiment 7), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 1 to 8, wherein R 2 is —(C 1 -C 6 )alkyl.
In an eighth embodiment (embodiment 8), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 1 to 8, wherein R 2 is selected from methyl and t-butyl.
In a ninth embodiment (embodiment 9), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 1 to 6, wherein R 2 is ferrocenyl.
In a tenth embodiment (embodiment 10), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 1 to 6, wherein R 2 is selected from —(C 2 -C 6 )alkenyl and —(C 2 -C 6 )alkynyl substituted by phenyl.
In an eleventh embodiment (embodiment 11), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 1 to 6, wherein R 2 is selected from phenyl substituted by 1,3-dimethoxyphenyl.
In a twelfth embodiment (embodiment 12), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 1 to 11, wherein R 4 is selected from phenylsulfonyl, pyridinylsulfonyl, and pyrimidinylsulfonyl; wherein each of said phenylsulfonyl, pyridinylsulfonyl, and pyrimidinylsulfonyl is optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, and —CF 3 .
In a thirteenth embodiment (embodiment 13), the invention relates to a method for making the compound of formula (I) according to any of embodiments 1 to 13, wherein the compound of formula (IIa) is reacted with the first organometallic reagent of formula M 1 -R 1 followed by reaction with the second organometallic reagent of formula M 2 -R 2 to provide the compound of formula (I).
In a fourteenth embodiment (embodiment 14), the invention relates to a method for making the compound of formula (I) according to embodiment 13, wherein the compound of formula (IIa) is a five-membered heterocyclic ring optionally substituted by 1 to 3 substituents independently selected from —(C 1 -C 6 )alkyl and —(C 6 -C 10 )aryl.
In a fifteenth embodiment (embodiment 15), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 13 or 14, wherein the compound of formula (IIa) is a five-membered heterocyclic ring substituted by a —(C 1 -C 6 )alkyl and phenyl.
In a sixteenth embodiment (embodiment 16), the invention relates to a method for making the compound of formula (I) according to embodiment 13, wherein the compound of formula (IIa) is a five-membered heterocyclic ring of formula:
wherein said five-membered heterocyclic ring is optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, —CF 3 , —(C 6 -C 10 )aryl, and -(5 to 11-membered)heteroaryl.
In a seventeenth embodiment (embodiment 17), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 13 to 16, wherein the compound of formula (IIa) is a five-membered heterocyclic ring of structure:
including diastereomers and enantiomers thereof.
In an eighteenth embodiment (embodiment 18), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 13 to 17, wherein the compound of formula (IIa) is a five-membered heterocyclic ring of structure:
In a nineteenth embodiment (embodiment 19), the invention relates to a method for making the compound of formula (I) according to any of one of embodiments 1 to 12, wherein the compound of formula (IIb) is reacted with the first organometallic reagent of formula
M 1 -R 1 followed by reaction with the second organometallic reagent of formula M 2 -R 2 to provide the compound of formula (I).
In a twentieth embodiment (embodiment 20), the invention relates to a method for making the compound of formula (I) according to embodiment 19, wherein ring B of the compound of formula (IIb) is a —(C 6 -C 10 )aryl optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, and —CF 3 .
In a twenty first embodiment (embodiment 21), the invention relates to a method for making the compound of formula (I) according to embodiment 19 or 20, wherein ring B of the compound of formula (IIb) is a C 6 -aryl optionally substituted by 1 to 3 substituents independently selected from halogen, hydroxyl, —(C 1 -C 6 )alkyl, —O(C 1 -C 6 )alkyl, and —CF 3 .
In a twenty second embodiment (embodiment 22), the invention relates to a method for making the compound of formula (I) according to embodiment 19, 20, or 21, wherein ring B of the compound of formula (IIb) is a C 6 -aryl substituted by halo.
In a twenty third embodiment (embodiment 23), the invention relates to a method for making the compound of formula (I) according to any one of embodiments 19 to 22, wherein the compound of formula (IIb) is:
DETAILED DESCRIPTION OF THE INVENTION
As noted above, the invention relates to methods of making compounds of formula (I), comprising allowing a compound of formula (IIa) or (IIb) to react with a first organometallic reagent of formula M 1 -R 1 followed by reaction with a second organometallic reagent of formula M 2 -R 2 to provide the compound of formula (I).
Unless otherwise defined herein, the compounds of formula (IIa) and (IIb) including diastereomers and enantiomers thereof.
For all compounds of the invention disclosed hereinabove in this application, in the event the nomenclature is in conflict with the structure, it shall be understood that the compound is defined by the structure.
Abbreviations:
EtOAc=ethyl acetate
Fc=ferrocenyl
isoPrMgCl=isopropylmagnesiumbromide
MeMgBr=methylmagnesiumbromide
MeO-BIBOP=3,3′-di-tert-butyl-4,4′-dimethoxy-2,2′,3,3′-tetrahydro-2,2′-bibenzo[d][1,3]oxaphosphole
2-MeO-PhMgB=2-methoxyphenylmagnesiumbromide
PhMgBr=phenylmagnesiumbromide
t-BuLi=tert-butyllithium
t-BuMgCl tert-butylmagnesiumbromide
Ts=4-methylphenylsulfonyl
All terms as used herein in this specification, unless otherwise stated, shall be understood in their ordinary meaning as known in the art. For example, “C 1-6 alkoxy” or “O(C 1-6 )alkyl” is a (C 1-6 )alkyl with a terminal oxygen, such as methoxy, ethoxy, propoxy, butoxy. All alkyl, alkenyl, and alkynyl groups shall be understood as being branched or unbranched where structurally possible and unless otherwise specified. Other more specific definitions are as follows:
The term “alkyl” refers to both branched and unbranched alkyl groups. It should be understood that any combination term using an “alk” or “alkyl” prefix refers to analogs according to the above definition of “alkyl”. For example, terms such as “alkoxy”, “alkythio” refer to alkyl groups linked to a second group via an oxygen or sulfur atom. “Alkanoyl” refers to an alkyl group linked to a carbonyl group (C═O).
The term “(C 1 -C 6 )alkyl” refers to branched and unbranched alkyl groups having from 1 to 6 carbon atoms. Examples of —(C 1 -C 6 )alkyls include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentane, iso-pentyl, neopentyl, n-hexane, iso-hexanes (e.g., 2-methylpentyl, 3-methylpentyl, 2,3-dimethylbutyl, and 2,2-dimethylbutyl). It will be understood that any chemically feasible carbon atom of the (C 1 -C 6 )alkyl group can be the point of attachment to another group or moiety.
In all alkyl groups or carbon chains, one or more carbon atoms can be optionally replaced by heteroatoms such as O, S or N. It shall be understood that if N is not substituted then it is NH. It shall also be understood that the heteroatoms may replace either terminal carbon atoms or internal carbon atoms within a branched or unbranched carbon chain. Such groups can be substituted as herein above described by groups such as oxo to result in definitions such as but not limited to: alkoxycarbonyl, acyl, amido and thioxo.
The term “(C 3 -C 6 )cycloalkyl” refers to a stable nonaromatic 3-6 membered monocyclic carbocyclic radical including cyclopropane, cyclobutane, cyclopentane, and cyclohexane.
The term “(C 6-10 )aryl” refers to aromatic hydrocarbon rings containing from six to ten carbon ring atoms. The term C 6-10 aryl includes monocyclic rings and bicyclic rings where at least one of the rings is aromatic. Non-limiting examples of C 6-10 aryls include phenyl, indanyl, indenyl, benzocyclobutanyl, dihydronaphthyl, tetrahydronaphthyl, naphthyl, benzocycloheptanyl and benzocycloheptenyl. The term “C 6 -aryl” refers to benzene.
The term “(5 to 11-membered)heterocycle” refers to a stable nonaromatic 4-8 membered monocyclic heterocyclic radical or a stable nonaromatic 6 to 11-membered fused bicyclic, bridged bicyclic or spirocyclic heterocyclic radical. The 5 to 11-membered heterocycle consists of carbon atoms and one or more, preferably from one to four heteroatoms chosen from nitrogen, oxygen and sulfur. The heterocycle may be either saturated or partially unsaturated. Non-limiting examples of nonaromatic 4-8 membered monocyclic heterocyclic radicals include tetrahydrofuranyl, azetidinyl, pyrrolidinyl, pyranyl, tetrahydropyranyl, dioxanyl, thiomorpholinyl, 1,1-dioxo-1λ 6 -thiomorpholinyl, morpholinyl, piperidinyl, piperazinyl, and azepinyl. Non-limiting examples of nonaromatic 6 to 11-membered fused bicyclic radicals include octahydroindolyl, octahydrobenzofuranyl, and octahydrobenzothiophenyl. Non-limiting examples of nonaromatic 6 to 11-membered bridged bicyclic radicals include 2-azabicyclo[2.2.1]heptanyl, 3-azabicyclo[3.1.0]hexanyl, and 3-azabicyclo[3.2.1]octanyl. Non-limiting examples of nonaromatic 6 to 11-membered spirocyclic heterocyclic radicals include 7-aza-spiro[3,3]heptanyl, 7-spiro[3,4]octanyl, and 7-aza-spiro[3,4]octanyl.
The term “(5 to 11-membered)heteroaryl” refers to an aromatic 5 to 6-membered monocyclic heteroaryl or an aromatic 7 to 11-membered heteroaryl bicyclic ring where at least one of the rings is aromatic, wherein the heteroaryl ring contains 1-4 heteroatoms such as N, O and S. Non-limiting examples of 5 to 6-membered monocyclic heteroaryl rings include furanyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, pyrazolyl, pyrrolyl, imidazolyl, tetrazolyl, triazolyl, thienyl, thiadiazolyl, pyridinyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, and purinyl. Non-limiting examples of 7 to 11-membered heteroaryl bicyclic heteroaryl rings include benzimidazolyl, quinolinyl, dihydro-2H-quinolinyl, isoquinolinyl, quinazolinyl, indazolyl, thieno[2,3-d]pyrimidinyl, indolyl, isoindolyl, benzofuranyl, benzopyranyl, benzodioxolyl, benzoxazolyl and benzothiazolyl.
It will be understood that one to three carbon ring moieties in the each of the (C 3 -C 6 )cycloalkyl and (5 to 11-membered)heterocyclic rings, the nonaromatic portion of the bicyclic aryl rings, and the nonaromatic portion of the bicyclic heteroaryl rings can independently be replaced with a carbonyl, thiocarbonyl, or iminyl moiety, i.e., —C(═O)—, —C(═S)— and —C(═NR 2 )—, respectively, where R 2 is as defined above.
The term “heteroatom” as used herein shall be understood to mean atoms other than carbon such as O, N, and S.
The term “halogen” as used in the present specification shall be understood to mean bromine, chlorine, fluorine or iodine. The definitions “halogenated”, “partially or fully halogenated”; partially or fully fluorinated; “substituted by one or more halogen atoms”, includes for example, mono, di or tri halo derivatives on one or more carbon atoms. For alkyl, a non-limiting example would be —CH 2 CHF 2 , —CF 3 etc.
Each alkyl, cycloalkyl heterocycle or heteroaryl, or the analogs thereof, described herein shall be understood to be optionally partially or fully halogenated.
The chiral phosphine oxides prepared by the methods of the invention are useful intermediates for making chiral phosphine ligands. For example, the chiral phosphine ligand MeO-BIBOP can be prepared from compound 6q as depicted below in Scheme 1 according to known procedures. (See (a) Tang, W.; Qu, B.; Capacci, A. G.; Rodriguez, S.; Wei, X.-T.; Haddad, N.; Narayana, B.; Ma, S.; Grinberg, N.; Yee, N. K.; Krishnamurthy, D.; Senanayake, C. H. Org. Lett. 2010, 12, 176-179. (b) Rodriguez, S.; Qu, B.; Haddad, N.; Reeves, D. C.; Tang, W.; Lee, H.; Krishnamurthy, D.; Senanayake, C. H. Adv. Synth. Catal. 2011, 353, 533-537. (c) Tang, W.; Keshipeddy, S.; Zhang, Y.; Wei, X.; Savoie, J.; Patel, N. D.; Yee, N. K.; Senanayake, C. H. Org. Lett., 2011, 13, 1366-1369).
General Synthetic Methods
Schemes 2 and 3 below each depict a process for making the compound of formula (I) according to the process of the invention.
As depicted in Scheme 2, the compound of formula (IIa) or (IIb) is allowed to react with the compound of formula M 1 -R 1 to form a first intermediate (not shown), which is then allowed to react with the compound with the compound of formula M 2 -R 2 to provide the compound of formula (I). Typically, the first intermediate can be either not isolated or isolated prior to reaction with the compound of formula M 2 -R 2 . Nonlimiting of compounds of formula M 1 -R 1 and M 2 -R 2 useful for making the compound of formula (I) include organolithium reagents and Grignard reagents. Nonlimiting examples of organolithium reagents include PhLi, t-BuLi, MeLi, isoPrLi, 2-MeO-PhLi, CH2-CHLi, and Ph—CCLi. Nonlimiting examples of Grignard reagents include PhMgBr, t-BuMgCl, MeMgBr, isoPrMgCl, and 2-MeO-PhMgBr. Organolithium and Grignard reagents are commercially available or can be prepared by known methods. The reaction depicted in Scheme 2 is carried out in anhydrous, aprotic solvent, such as THF, methylene chloride, ethyl acetate, etc. and under inert atmosphere (e.g., N 2 , He, Ar).
The compound of formula (IIa) can be prepared according to the process depicted below in Scheme 3.
As depicted in Scheme 3 above, the compound of formula (IIa) is allowed to react with a phosphorus compound of formula R 3 P(X)Cl 2 in the presence of base, such as pyridine and its derivatives, triethylamine and its derivatives, imidazole and its derivatives, and others to provide the compound of formula (IIa). The R groups depicted in Scheme 3 for the compound of formula (IIa) represent the optional substituents of ring A as defined above, and n is an integer from 0 to 2.
The compound of formula (IIb) can be prepared by the method depicted below in Scheme 4.
Compounds of formula (IIb) and R 3 P(X 1 )Cl 2 are commercially available or can be prepared by known methods.
The method for making the compound of formula (IIb) depicted in Scheme 4 above is carried out in a manner similar to that described above for making the compound of formula (IIa) except that the compound of formula (IIb) is used instead of the compound of formula (IIb). Compounds of formula (IIb) are commercially available or can be prepared by known methods.
EXPERIMENTAL
Methods of making the compound of formula (I) using compounds of formula (IIb) are described in Examples 1-17 below.
Step 1: Preparation of Cyclic Intermediates
Scheme 5 below shows a nonlimiting method for making a cyclic intermediate (Intermediate 2) which corresponds to the compound of formula (IIb) described above.
As depicted in Scheme 5, intermediate 2 can be prepared by reacting of compound 1 with O═PCl 2 R in the presence of base. Intermediate 2 can also be prepared by reacting compound 3 followed with hydrogen peroxide. Compound 3 can be prepared by reacting 1 with PCl 2 R. Alternatively, 3 can be prepared by reacting 1 with PCl 3 to provide compound 4, and reacting 3 with an organometallic reagent (e.g., LiR 3 , MgR 1 . or ZnX) to provide 2 (where X is chloro, bromo or iodo).
The methods depicted above in Scheme 5 can be used to prepare specific compounds of formula (IIb) (compounds 2a-2d) shown in Table 2 and Scheme 6 below.
TABLE 1
Synthesis of 2
Entry
R 3
Base
Product
yield
dr
1
1-methyl- imidazole
75%
>99%
2
DMAP
78%
>99%
3
and then H 2 O 2
Pyridine
75%
>99%
Synthesis of Intermediate 2a
A solution of (R)—N-(1-(5-chloro-2-hydroxyphenyl)ethyl)-4-methylbenzenesulfonamide (1, 100.0 g, 307.69 mmol) in anhydrous dichloromethane (1200 ml) is cooled to −10° C. and then phenyl phosphonic dichloride (57.55 ml, 369.23 mmol, 90% by wt), is added to the reaction mixture. Then 1-methyl imidazole (61.02 ml, 769.2 mmol) is added over 30 minutes while maintaining reaction temperature <−5° C. under argon atmosphere. After completion of the reaction, water (500 mL) is added to reaction mixture to quench the reaction. The phases are separated and the organic phase is washed with 400 ml of 1N HCl followed by 100 ml of water and then 200 ml of saturated sodium bicarbonate solution. The organic phase is then filtered through Celite and then is concentrated. The residue is recrystallized using EtOAc: Hexane (500 ml: 1200 ml) to get 2a (103 g, 75%) as a white solid. 1 H NMR (400 MHz, CDCl 3 ) δ 1.3 (d, J=7.1 Hz, 3H), 2.29 (s, 3H), 3.8 (s, 3H), 4.58-4.67 (m, 1H), 6.06 (d, J=9.0 Hz, 1H), 6.76 (d, J=2.7 Hz, 1H), 6.88 (dd, J=2.8, 8.7 Hz, 1H), 6.95-7.02 (m, 3H), 7.09-7.18 (m, 2H), 7.43-7.51 (m, 4H), 7.54-7.63 (m, 2H), 7.88-7.95 (m, 2H), 8.1 (ddd, J=1.5, 7.6 Hz, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 21.7, 24.5, 56.1, 121.7 (d, J=4.7 Hz), 125.8 (d, J=1.5 Hz), 127.5, 128.3, 128.7, 128.9, 129.4, 129.8 (d, J=2.6 Hz), 130.5, 131.5, 131.6, 132.2 (d, J=11.8 Hz), 133.4 (d, J=3.4 Hz), 135.2, 144.9, 145.7 (d, J=8.9 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 13.530.
Synthesis of Intermediate 2b
A solution of (R)—N-(1-(5-chloro-2-hydroxyphenyl)ethyl)-4-methylbenzenesulfonamide (1, 100.0 g, 307.69 mmol) in anhydrous dichloromethane (800 ml) is cooled to −10° C. and then methyl phosphonic dichloride (61.19 g., 460.38 mmol) is added to the reaction mixture. Then 4-N,N-dimethyl-pyridine (DMAP) (78.7 g., 644.53 mmol) is added over 30 minutes while maintaining the temperature <−10° C. under argon atmosphere. Then the mixture is stirred at 0° C. for about 2 h to complete the reaction. The reaction mixture is quenched by adding 400 ml of water and the aqueous phase is extracted once with methylene chloride. The combined organic phase organic phases were washed with 350 ml of 1N HCl. The organic phase is then filtered through Celite and concentrated. The residue is recrystallized using isopropanol: water to get 2b (92 g, 78% yield) as a white solid. 1 H NMR (400 MHz, CDCl 3 ) δ 1.67 (d, J=76.8 Hz, 3H), 2.29 (d, J=17.9 Hz, 3H), 2.38 (s, 3H), 4.47-4.57 (m, 1H), 6.86 (d, J=2.5 Hz, 1H), 7.01 (dd, J=1.1, 8.6 Hz, 1H), 7.2 (dd, J=2.4, 8.5 Hz, 1H), 7.24 (s, 1H), 7.26 (s, 1H), 7.95 (dd, J=1.8, 5.8 Hz, 2H). 13 C NMR (100 MHz, CDCl 3 ) δ 17.2, 18.5, 21.5, 23.5, 55.7, 121.2 (d, J=4.2 Hz), 125.8 (d, J=1.5 Hz), 127.9, 129.7, 129.8, 130.2 (d, J=1.7 Hz), 131.6 (d, J=8.1 Hz), 135.5, 144.7, 145.2 (d, J=9.4 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 24.37
Synthesis of Intermediate 2c
A solution of 1 (19.57 g, 60.24 mmol) in anhydrous dichloromethane (220 ml) is cooled to −20° C. and then dimethoxy phosphine dichloride (14.40 g., 60.24 mmol) is added to the reaction mixture. Then pyridine (10.48 ml, 79.10 mmol) is added over 30 minutes while maintaining the reaction temperature <−10° C. under argon atmosphere. After addition, the reaction mixture is brought to room temperature and the mixture is stirred at for 2-3 hours and then cooled it to <0° C. Water (100 mL) is added to quench the reaction. The aqueous is removed and the organic phase is washed with 100 ml of 1N HCl and 50 ml of NaHCO 3 . And to the organic phase H 2 O 2 (7.65 mmol, 78.20 mmol) is added and stirred for another 3 hours. The organic phase is washed using brine and the organic phase is concentrated. The residue is purified on column to yield 2c (23 g, 75% yield) as a white solid. 1 H NMR (400 MHz, CDCl 3 ) δ 1.59 (d, J=7.0 Hz, 3H), 2.36 (s, 3H), 3.98 (s, 6H), 4.58-4.68 (m, 1H), 6.62-6.67 (m, 1H), 6.75 (d, J=2.5 Hz, 1H), 7.05-7.08 (m, 1H), 7.14-7.15 (m, 1H), 7.20 (d, J=8.4 Hz, 2H), 7.48 (t, J=8.5 Hz, 1H), 8.04 (d, J=8.4 Hz, 2H). 31 P NMR (400 MHz, CDCl 3 ) δ 7.220
Step 1: Preparation of Ring-opened Intermediates
Cyclic intermediate 2 can be reacted with an organometallic reagent to provide the ring-opened intermediate 5 as shown in Table 2 below.
TABLE 2
Synthesis of intermediate 5
Entry
R 1 MgX
product/yield
dr
1
5a/91%
>99:1
2
5b/72%
>99:1
3
t-BuLi
5c/65%
>99:1
4
5d/52%
>99:1
5 6
5e/85%
>99:1
Cyclic intermediate 2a can be reacted with an organometallic reagent to provide the ring-opened intermediates 5a-5d as described below.
Synthesis of (R)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl 2-methoxyphenyl(phenyl)phosphinate (5a)
A solution of 2a (4.0 g, 8.93 mmol) in anhydrous THF (40 ml) is cooled to −20° C. under argon atmosphere. And then 2-methoxy phenyl magnesium bromide (9.8 ml, 9.8 mmol, 1.0 M in THF) is added dropwise to the reaction mixture and stirred for 2 hours at −20° C. After the starting material is consumed completely, the reaction mixture is quenched using 10 ml of saturated ammonium chloride solution and diluted with 100 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated. The residue on column eluted with hexane: ethyl acetate, (70:30, v/v) to get 5a as while solid (4.5 g, 91%) in >99:1 dr. 1 H NMR (400 MHz, CDCl 3 ) δ 1.3 (d, J=7.1 Hz, 3H), 2.29 (s, 3H), 3.8 (s, 3H), 4.58-4.67 (m, 1H), 6.06 (d, J=9.0 Hz, 1H), 6.76 (d, J=2.7 Hz, 1H), 6.88 (dd, J=2.8, 8.7 Hz, 1H), 6.95-7.02 (m, 3H), 7.09-7.18 (m, 2H), 7.43-7.51 (m, 4H), 7.54-7.63 (m, 2H), 7.88=7.95 (m, 2H), 8.1 (ddd, J=1.5, 7.6 Hz, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 21.4, 22.4, 50.1, 55.9, 111.8 (d, J=7.9 Hz), 117.4, 118.7, 121.0, 121.2, 121.4 (d, J=3.9 Hz), 126.8, 127.8, 128.3 (d, J=5.3 Hz), 128.5, 129.2, 130.9, 131.4, 131.5, 132.3, 132.4 (d, J=2.9 Hz), 134.3 (d, J=6.0 Hz), 135.0 (d, J=7.2 Hz), 135.5 (d, J=1.9 Hz), 137.5, 142.9, 146.9 (d, J=8.5 Hz), 160.6 (d, J=4.6 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 30.918.
Synthesis of (R)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl 2-(1,3-dioxolan-2-yl)phenyl(phenyl)phosphinate (5b)
A solution of 2a (10.0 g, 22.32 mmol) in anhydrous THF (80 ml) is cooled to −20° C. under argon atmosphere. And then freshly prepared 2-ethylene diacetal phenyl magnesium bromide (39 ml, 31.24 mmol, 0.8 M in THF) is added dropwise to the reaction mixture and stirred for 2 hours at −20° C. After the starting material is consumed completely, the reaction mixture is quenched using 20 ml of saturated ammonium chloride solution and diluted with 200 ml of ethyl acetate. The organic layer is separated and dried over sodium sulphate and concentrated. The residue is purified on column eluted with 30:70 hexane:ethyl acetate to get 5b as a white solid (9.5 g, 71%) in >99:1 dr. 1 H NMR (400 MHz, CDCl 3 ) δ 1.19 (d, J=7.1 Hz, 3H), 2.32 (s, 3H), 3.87-3.99 (m, 3H), 4.01-4.10 (m, 1H), 4.74 (q, J=6.8 Hz, 1H), 5.66 (d, J=7.5 Hz, 1H), 6.5 (s, 1H), 6.88-6.93 (m, 2H), 7.02-7.09 (m, 3H), 7.43-7.59 (m, 6H), 7.66 (t, J=7.1 Hz, 1H), 7.74-7.88 (m, 3H), 8.06-8.12 (m, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 21.4, 22.1, 48.5, 65.1, 65.4, 100.3 (d, J=4.0 Hz), 121.9 (d, J=3.8 Hz), 126.8, 127.7, 127.8, 128.1, 128.6, 128.8, 129.0, 129.2, 129.3, 129.4, 129.8, 131.0, 131.1, 131.2, 132.6 (d, J=2.8 Hz), 133.2 (d, J=6.7 Hz). 137.5, 142.1, 142.2, 143.0, 146.3, 146.4. 31 P NMR (162 MHz, CDCl 3 ) δ 32.271 ppm.
Synthesis of (S)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl tert-butyl(phenyl)phosphinate (5c)
A solution of 2a (5 g, 11.18 mmol) in anhydrous THF (60 ml) is cooled to −70° C. under argon atmosphere. And then t-BuLi (8.3 ml, 13.4 mmol, 1.6 M in pentane) is added dropwise and the mixture is stirred for 1 hour at −70° C. After the starting material is consumed completely, the reaction mixture is quenched using 10 ml of saturated ammonium chloride solution and extracted using 200 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated. The residue is purified on column eluted with 10:90 hexane: ethyl acetate to provide 5c as a white solid (3.6 g, 65%) in >99:1 dr. 1 H NMR (400 MHz, CDCl 3 ) δ 1.3 (d, J=16.6 Hz, 9H), 1.40 (d, J=6.9 Hz, 3H), 2.31 (s, 3H), 5.05 (q, J=7.1 Hz, 1H), 6.03 (d, J=7.8 Hz, 1H), 6.8 (dd, J=2.6, 8.8 Hz, 1H), 7.01-7.12 (m, 4H), 7.43-7.50 (m, 2H), 7.54-7.60 (m, 3H), 7.72-7.80 (m, 2H). 13 C NMR (100 MHz, CDCl 3 ) δ 21.4, 23.3, 24.2, 33.3, 34.3, 47.3, 120.6 (d, J=4.4 Hz), 126.8, 127.2, 127.7, 128.0, 128.5, 128.6, 129.1, 129.4, 132.7 (d, J=2.6 Hz), 132.9, 133.0, 133.9 (d, J=6.1 Hz), 137.2, 143.2, 146.8 (d, J=9.6 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 50.882 ppm.
Synthesis of (R)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl mesityl(phenyl)phosphinate (5d)
A solution of 2-mesityl magnesium bromide (24.1 ml, 24.1 mmol, 1.0 M in THF), Lithium chloride (48.3 ml, 24.1 mmol, 0.5 M in THF) and dioxane (2.36 ml, 26.8 mmol) are mixed together and heated at 45° C. for 1 hour and then the mixture is brought to room temperature and then 2a (4 g, 8.94 mmol) dissolved in 30 ml THF is added to this reaction flask dropwise. After addition, the mixture warmed to 60° C. and stirred for 6 hours. The reaction is quenched using 10 ml of ammonium chloride saturated solution and the mixture is extracted using 100 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated. The residue is purified on column to yield 5d as a white solid (2.6 g, 52%) in >99:1 dr. 1 H NMR (400 MHz, CDCl 3 ) δ 1.39 (d, J=6.9 Hz, 3H), 2.32 (s, 3H),2.34 (s, 3H), 2.50 (s, 3H), 4.74 (q, J=7.3 Hz, 1H), 5.87 (d, J=7.1 Hz, 1H), 6.66-6.69 (m, 1H), 6.85-6.90 (m, 2H), 6.98 (d, J=4.1 Hz, 2H), 7.04 (d, J=7.9 Hz), 7.42-7.50 (m, 2H), 7.53-7.59 (m, 3H), 7.6-7.81 (m, 2H). 13 C NMR (100 MHz, CDCl 3 ) 6 21.2 (d, J=1.4 Hz), 21.4, 22.8, 23.4 (d, J=3.4 Hz), 48.7, 121.1 (d, J=3.8 Hz), 122.2, 123.4, 126.9, 128.1 (d, J=16.2 Hz), 128.9 (d, J=14.0 Hz), 129.8, 130.2 (d, J=13.2 Hz), 131.3 (d, J=13.4 Hz), 132.3 (d, J=3.0 Hz), 132.7, 134.1, 135.5 (d, J=5.1 Hz), 137.4, 143.0, 143.2 (d, J=3.0 Hz), 143.9, 144.0, 145.8 (d, J=8.3 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 36.669.
Synthesis of (S)-4-chloro-2-((R)-1-(4-methylphenylsulfonamido)ethyl)phenyl ((r)-2′,6′-dimethoxybiphenyl-2-yl)(phenyl)phosphinate 5e
A solution of 2′-bromo-2,6-dimethoxybiphenyl (2 g, 6.83 mmol) in THF (30 mL) was cooled −70° C. and nBuLi (3.5 mL, 2 M in hexane) was added slowly and the mixture was stirred for 2 h at that temperature. Then the mixture was warmed to −20° C. and stirred for 15 min and cooled to −70° C. again. A solution of 2a (2.7 g, 6.03 mmoL) in THF (50 mL) was added dropwise. The reaction mixture was stirred about 2 h at that temperature and warmed to −20° C. and stirred for about 30 min to complete the reaction. Then 10 mL of saturated ammonium chloride solution was added top quench the reaction and the mixture was extracted with 60 mL of ethyl acetate. The organic phase was dried and concentrated. The residue was purified on column eluted with EtOAc/hexane (10:90 to 45:55, v/v) to yield 3.8 g product in 85% yield and >99.5:0.5 er. 1 H NMR (400 MHz, CDCl 3 ) δ 1.19 (d, J=7.2 Hz, 3H), 2.36 (s, 3H), 3.17 (s, 3H), 3.44(s, 3H), 4.64 (m, 1H), 5.76 (d, J=6.52 Hz, 1H), 6.32 (d, J=8.56 Hz, 2H), 6.75-6.80 (m, 1H), 6.84-6.89 (m, 1H), 6.96-7.00 (m, 1H), 7.01-7.10 (m, 2H), 7.15-7.27 (m, 4H), 7.29-7.37 (m, 2H), 7.37-7.43 (m, 1H), 7.51-7.57 (m, 1H), 7.61-7.70 (m, 3H), 8.28-8.36 (m, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 21.50, 22.22, 48.44, 54.82, 55.30, 102.79, 103.34, 116.74, 116.78, 122.36, 122.39, 127.12, 127.15, 127.25, 127.69, 127.82, 127.89, 127.92, 129.37, 129.62, 129.73, 129.80. 130.21, 130.97, 131.17, 131.28, 131.51, 131.54, 131.59, 132.68, 132.80, 132.83, 133.36, 133,44, 135.40, 135.45, 137.36, 139.68, 139.81, 143.02, 146.20, 146.28, 157.52, 158.14. 31 P NMR (162 MHz, CDCl 3 ) δ 30.92; HRMS: calculated for C 35 H 33 ClNO 6 PS (M+H): 662.1533; found: 662.1525.
EXAMPLES 1-7
Scheme 8 below describes a method of making the compounds of the invention by reacting cyclic intermediate 2a with (2-methoxyphenyl)magnesium bromide to provide the compound 5a followed by reaction with a lithium alkyl to provide a compound of the invention (denoted as compound 6).
Specific compound of the invention prepared according to Scheme 8 are described in Table 3.
TABLE 3
Synthesis of compounds of the invention (Ex-1 to Ex-7).
Entry
R 2 M
Product
er
yield
Ex. 1
MeMgBr
>99%
91%
Ex. 2
tBuLi
97%
84%
Ex. 3
Fc—Li Fc = Ferrocene
>99%
82%
Ex. 4
isopropyl-Li
>95%
63%
Ex. 5
vinyl-MgBr
>98%
70%
Ex. 6
96%
54%
Ex. 7
98%
87%
Example 1
Synthesis of 6a
A solution of (R)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl 2-methoxyphenyl(phenyl)phosphinate (5a, 0.2 g, 0.359 mmol) in anhydrous THF (5 ml) is cooled to −10° C. under argon atmosphere. Then methyl Grignard reagent (0.47 ml, 1.43 mmol, 3.0 M in THF) is added dropwise to the reaction mixture and stirred for 15 minutes at −10° C. After the starting material is consumed completely, the reaction mixture is quenched using 1 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated. The residue is purified on column eluted with 5% MeOH-ethyl acetate mixture to provided 6a (88 mg, 91% yield) in 99.9:0.1 er. 1 H NMR (400 MHz, CDCl 3 ) δ 2.07 (d, J=14.1 Hz, 3H), 3.72 (s, 3H), 6.86-6.91 (m, 1H), 7.07-7.13 (m, 1H), 7.39-7.53 (m, 4H), 7.71-7.77 (m, 2H), 7.96 (ddd, J=1.8, 7.96 Hz, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 15.8, 16.5, 55.2, 110.8 (d, J=6.6 Hz), 121.0 (d, J=11.0 Hz), 121.9, 128.2 (d, J=12.1 Hz), 130.2 (d, J=10.2 Hz), 131.2 (d, J=2.8 Hz), 133.8-134.0 (m), 134.5 135.5, 159.9 (d, J=4.9 Hz). 31 P (162 MHz, CDCl 3 ) δ 28.39 ppm. HPLC: Column: Chiralpack AD-H, 4.6×250 mm; IPA: Hexane (12:88), 1.5 ml/min, 220 nm, r t =10.8 min, 14.5 min
Example 2
Synthesis of 6b
A solution of (R)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl 2-methoxyphenyl(phenyl)phosphinate (5a, 0.250 g, 0.450 mmol) in anhydrous THF (5 ml) is cooled to −70° C. under argon atmosphere. Then t-BuLi (1.2 ml, 1.8 mmol, 1.6 M in pentane) is added dropwise to the reaction mixture and stirred for 30 minutes at −70° C. After the starting material is consumed completely, the reaction mixture is quenched using 2 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated. The residue is purified on column eluted with 5% MeOH-ethyl acetate mixture to get 6b (108 mg, 83%) in 98.7:1.3 er. 1 H NMR (100 MHz, CDCl 3 ) δ 1.26 (d, J=15.5 Hz, 9H), 3.7 (s, 3H), 6.81-6.93 (m, 1H), 7.1 (t, J=7.2 Hz, 1H), 7.37-7.57 (m, 4H), 7.91-7.97 (m, 2H), 8.17 (ddd, J=1.6, 7.5 Hz). 13 C NMR (100 MHz, CDCl 3 ) δ 25.9 (d, J=1.0 Hz), 35.3, 35.1, 54.6, 110.8 (d, J=6.6 Hz), 119.7, 120.7, 120.9 (d, J=10.1 Hz), 127.8 (d, J=11.4 Hz), 131.0 (d, J=2.8 Hz), 132.0 (d, J=8.9 Hz), 132.5, 133.4, 133.5 (d, J=2.1 Hz), 136.1 (d, J=4.9 Hz), 159.5 (d, J=4.2 Hz). 31 P NMR: (162 MHz, CDCl 3 ) δ 42.686
Chiral HPLC: ChiralpackAD-H, 4.6×250 mm; IPA: Heptane (25:75), 1.2 ml/min, 220 nm, r t =3.7 min and 4.7 min
Example 3
Synthesis of 6c
A solution of (R)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl 2-methoxyphenyl(phenyl)phosphinate (5a, 0.2 g, 0.359 mmol) in anhydrous THF (5 ml) is cooled to −78° C. under argon atmosphere. Then fresh generated ferrocenyl lithium (FcLi) at −78 C. The reaction is completed in 30 minutes. The reaction is quenched using 2 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated. The residue is purified on column to provide 6c (123 mg, 82% yield) in 99.7:0.3 er. 1 H NMR (500 MHz, CDCl 3 ) δ 3.52 (s, 3H), 4.13 (s, 5H), 4.44 (s, 2H), 4.47 (s, 1H), 4.59 (s, 1H), 6.85-6.90 (m, 1H), 7.10 (t, J=7.6 Hz, 1H), 7.35-7.40 (m, 1H), 7.41-7.46 (m, 1H), 7.50 (t, J=7.27 Hz, 1H), 7.64-7.70 (m, 1H), 7.96 (ddd, J=1.8 Hz, 7.5 Hz, 1H). 13 C NMR (125 MHz, CDCl 3 ) δ 55.2, 69.5, 69.6, 70.9, 71.0, 71.2, 72.1, 72.2, 72.6, 72.8, 72.9, 73.6, 111.5 (d, J=6.4 Hz), 120.6 (d, J=11.4 Hz), 122.5, 123.3, 127.7, 127.8, 130.8, 130.8, 130.9, 133.6 (d, J=1.9 Hz), 134.3, 134.4, 135.4, 136.3, 160.3 (d, J=3.8 Hz). 31 P NMR (300 MHz, CDCl 3 ) δ 26.948 ppm.
HPLC: ChiralpackAD-H, 4.6×250 mm; IPA: Heptane (25:75); 1.2 ml/min; 230 nm, r t =10.2, 10.9 min
Example 4
Synthesis of 6d
A solution of (R)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl 2-methoxyphenyl(phenyl)phosphinate (5a, 0.2 g, 0.359 mmol) in anhydrous THF (5 ml) is cooled to −70° C. under argon atmosphere. And then isopropyl-Li (1.52 ml, 1.07 mmol, 0.7 M in pentane) is added dropwise to the reaction mixture and stirred for 30 minutes at −70° C. After the starting material is consumed completely, the reaction is quenched using 2 ml of saturated ammonium chloride solution and then it is extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated. The residue purified on column eluted with 5% MeOH-ethyl acetate to provide 6d (62 mg, 63%) in 99:1 er. 1 H NMR (400 MHz, CD 3 OD) δ 0.94-1.07 (m, 6H), 2.87-2.96 (m, 1H), 3.85 (s, 3H), 7.06-7.13 (m, 2H), 7.45-7.56 (m, 4H), 7.81-7.90 (m, 3H). 13 C NMR (100 MHz, CD 3 OD) δ 14.6 (d, J=3.1 Hz), 14.9 (d, J=2.8 Hz), 24.7, 25.5, 55.3, 111.3 (d, J=6.7 Hz), 120.0, 120.8 (d, J=10.3 Hz), 120.9, 128.2 (d, J=11.3 Hz), 130.7 (d, J=9.2 Hz), 131.2 (d, J=2.7 Hz), 132.9, 133.5 (d, J=4.8 Hz), 133.7 (d, J=2.2 Hz), 133.8, 159.0 (d, J=4.8 Hz). 31 P NMR (162 MHz, CD 3 OD) δ 35.689 ppm. HPLC: Column: ChiralpackAD-H, 4.6×250 mm; IPA: Heptane (25:75), 1.2 ml/min, 220 nm, r t =4.1 min, 4.8 min.
Example 5
Synthesis of 6e
A solution of (R)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl 2-methoxyphenyl(phenyl)phosphinate (5a, 0.2 g, 0.359 mmol) in anhydrous THF (5 ml) is cooled to −40° C. under argon atmosphere. And then vinyl magnesium chloride (0.78 ml, 1.25 mmol, 1.6 M in THF) is added dropwise to the reaction mixture and stirred for 30 minutes at −40° C. After the starting material consumed, the reaction is quenched with saturated NH4Cl solution and extracted with ethyl acetate. The organic layer is dried over sodium sulphate and concentrated. The residue is purified on column to provide 6e (65 mg, 70% yield) in >99:1 er. 1 H NMR (400 MHz, CDCl 3 ) δ 3.67 (s, 3H), 6.28 (dd, J=1.8, 12.7 Hz, 1H), 6.50 (dd, J=1.9, 18.7 Hz), 6.79-6.95 (m, 2H), 7.10-7.16 (m, 1H), 7.37-7.55 (m, 4H), 7.62-7.69 (m, 2H), 8.02 (ddd, J=1.8, 7.5 Hz, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 55.3, 110.9 (d, J=6.8 Hz), 119.6, 120.6, 121.2 (d, J=11.5 Hz), 128.1, 128.2, 128.3, 130.5, 130.6, 130.7, 131.3 (d, J=2.7 Hz), 133.6, 134.0, 134.1, 134.1, 134.2, 134.7, 160.0(d, J=4.1 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 20.76 ppm. HPLC: Column: ChiralpackAD-H, 4.6×250 mm; Heptane/EtOH (85/15), 1.0 ml/min, 220 nm, r t =7.2 min, 10.3 min.
Example 6
Synthesis of 6f
A solution of (R)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl 2-methoxyphenyl(phenyl)phosphinate (5a, 0.100 g, 0.179 mmol) in anhydrous THF (5 ml) is cooled to −70° C. under argon atmosphere. And then phenylacetylidine lithium (0.55 ml, 0.537 mmol, 1.0 M in THF) is added dropwise to the reaction mixture and stirred for 30 minutes at −70° C. After the starting material is consumed, the reaction is quenched using 1 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated and purified on column to provide 6f (59 mg, 53% yield) in 98.1:1.8 er. 1 H NMR (400 MHz, CDCl 3 ) δ 3.70 (s, 3H), 6.88-6.93 (m, 1H), 7.09-7.14 (m, 1H), 7.34-7.61 (m, 9H), 7.88-7.96 (m, 2H), 8.07 (ddd, J=1.8 Hz, 7.6 Hz, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 55.5, 76.7, 84.1, 103.5, 103.8, 111.5 (d, J=7.1 Hz), 120.5, 120.8 (d, J=13.3 Hz), 121.2, 128.0, 128.2, 128.5, 130.3, 130.7, 130.8, 131.6 (d, J=3.1 Hz), 132.4 (d, J=1.8 Hz), 133.8 (d, J=8.0 Hz), 134.5 (d, J=2.0 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ: 5.5 ppm. Chiral HPLC: ChiralpackAD-3, 4.6×150 mm; IPA: Heptane (25:75); 1.5 ml/min, 220 nm, r t =4.1 min and 5.4 min.
Example 7
Synthesis of 6 g
A solution of (R)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl 2-methoxyphenyl(phenyl)phosphinate (5a, 0.100 g, 0.180 mmol) in anhydrous THF (5 ml) is cooled to −70° C. under argon atmosphere. And in another round bottom flask corresponding biaryl-dimethoxy-Li specie is prepared by reacting biaryl-dimethoxy-bromide (200 mg, 0.684 mmol) with n-butyl lithium (0.27 ml, 0.684 mmol, 2.5 M in hexane), in dry THF at −70° C. for 30 minutes and then warm to −25° C., stirred for 30 minutes and a slurry formed and it is added to the another stiffing flask while maintaining the temperature below −70° C. and stirred for 30 minutes. After the starting material is consumed completely, the reaction mixture is quenched using 2 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated and purified on column to provide 6 g (68 mg, 87% yield) in 99.2:0.8 er. 1 H NMR (400 MHz, CDCl 3 ) δ 3.42 (s, 3H), 3.51 (d, J=13.3 Hz, 6H), 6.18 (d, J=8.9 Hz, 1H), 6.26 (d, J=8.2 Hz, 1H), 6.7 (bt, J=7.2 Hz, 1H), 6.8 (t, J=7.0 Hz, 1H), 7.01 (t, J=8.4 Hz, 1H), 7.15-7.21 (m, 1H), 7.23-7.40 (m, 5H), 7.46-7.55(m, 2H), 7.58-7.69 (m, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ 55.0, 55.1, 55.3, 102.9 (d, J=13.4 Hz), 110.8 (d, J=6.7 Hz), 117.7 (d, J=3.9 Hz), 120.4 (d, J=11.6 Hz), 121.4, 122.4, 126.2 (d, J=12.9 Hz), 127.3 (d, J=12.7 Hz), 129.1, 130.5 (d, J=2.9 Hz), 130.8 (d, J=2.7 Hz), 131.9 (d, J=10.6 Hz), 132.3 (d, J=10.2 Hz), 132.6, 133.1 (d, J=1.9 Hz), 133.4, 133.5, 133.7, 134.5, 134.6 (d, J=6.9 Hz), 139.0 (d, J=8.14 Hz), 157.5, 157.8, 160.4 (d, J=3.4 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 26.041. Chiral HPLC: Chiral AGP, 4.0×150 mm; pH5 buffer MB: ACN; isocratic: 79/21; 1.1 ml/min, 220 nm, r t =5.4 min and 7.6 min.
EXAMPLES 8-10
Scheme 9 below describes a method of making the compounds of then invention by reacting cyclic intermediate 2a with (2-methoxyphenyl)magnesium bromide to provide the compound 5b followed by reaction with a lithium alkyl to provide a compound of the invention (denoted as compound 6).
Specific compounds of the invention prepared according to Scheme 9 are described in Table 4 below.
Entry
R 2 M
Product
ee
yield
Ex. 8
CH 3 MgCl
>95%
73%
Ex. 9
t-BuLi
>80%
34%
Ex. 10
Fc—Li
>97%
82%
Fc = Ferocene
Example 8
Synthesis of 6h
A solution of (5b, 10.0 g, 16.722 mmol) in anhydrous THF (80 ml) is cooled to −10° C. under argon atmosphere. Methyl Grignard reagent (22 ml, 66.88 mmol, 3.0 M in THF) is added dropwise to the reaction mixture and stirred for 45 minutes at −10° C. After the starting material is consumed, the reaction is quenched using 10 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated. The residue is purified on column to provide 6h (3.5 g, 73% yield) in 99:1 er. 1 H NMR (400 MHz, CDCl 3 ) δ 2.11 (d, J=13.1 Hz, 3H), 3.85-4.07 (m, 4H), 7.37-7.62 (m, 6H), 7.67-7.74 (m, 2H), 7.78-7.83 (m, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 17.7, 18.4, 65.3, 100.1 (d, J=4.5 Hz), 127.4 (d, J=9.5 Hz), 128.5, 128.6, 128.7, 128.8, 130.5 (d, J=9.9 Hz), 131.7 (d, J=2.8 Hz), 131.8, 131.9, 132.0 (d, J=2.7 Hz), 132.8, 134.3, 135.3, 141.5 (d, J=7.1 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 32.387 ppm. HPLC: Column: ChiralpackAD-3, 4.6×150 mm; Heptane: EtOH (60:40), 1.0 ml/min, 220 nm, r t =9.2 min, 10.3 min.
Example 9
Synthesis of 6i
A solution of 5b (0.2 g) in THF (5 mL) is cooled -72° C. and t-BuLi (0.6 mL, 1.7 M in heptanes) is added dropwise. The reaction mixture is stirred for 30 min and added 2 mL of ammonium chloride solution to quench the reaction and diluted with EtOAc. The organic is removed and the aqueous phase is extracted with CH 2 Cl 2 The combined organic solvent is concentrated and the residue is purified on column to yield 0.04 g product (34%). NMR (500 MHz): 1 H: 1.34 (d, J=14.85 Hz, 9H), 3.88-3.95 (m, 1H), 3.95-4.02 (m, 1H), 4.05-4.10 (m, 1H), 4.10-4.16 (m, 1H), 6.85 (s, 1H), 7.34-7.40 (m, 1H), 7.43-7.48 (m, 2H), 7.48-7.52 (m, 1H), 7.60-7.66 (m, 1H), 7.84-7.90 (m, 3H). P 31 :43.71. C 13 :25.84, 34.27, 34.83, 65.46, 65.48, 99.66, 99.69, 127.87, 127.96, 128.20, 128.29, 128.98, 129.06, 131.35, 131.37, 131.65, 131.99, 132.08, 132.18, 132.25, 143.78, 143.83.
Example 10
Synthesis of 6j
A solution of (5b, 7.0 g, 11.705 mmol) in anhydrous THF (60 ml) is cooled to −70° C. under argon atmosphere. And then freshly prepared FcLi (35.117 mmol) is added dropwise to the reaction mixture while maintaining temperature below −70° C. and stirred for 30 minutes at −70° C. After the starting material is consumed, the reaction is quenched using 30 ml of saturated ammonium chloride solution and extracted using 300 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated and purified on column to provide 6j (3.5 g, 67%) in 98.1:1.9 er. 1 H NMR (400 MHz, CDCl 3 ) δ 3.69-3.75 (m, 1H), 3.84-3.95 (m, 2H), 3.99-4.01 (m, 1H), 4.05 (q, J=6.8 Hz, 1H), 4.26 (s, 5 H), 4.41-4.43 (m, 1H), 4.53-4.56 (m, 1H), 4.66-4.69 (m, 1H), 6.45 (s, 1H), 7.29-7.36 (m, 2H), 7.43-7.54 (m, 4H), 7.64-7.71 (m, 2H), 7.75 (dd, J=3.8, 7.9 Hz, 1H). 13 C NMR (400 MHz, CDCl 3 ) δ 14.3, 65.3, 65.4, 69.9, 71.4 (d, J=10.9 Hz), 72.1, 72.2 (d, J=4.9 Hz), 72.4, 73.4 (d, J=13.9 Hz), 74.6, 77.4, 100.4 (d, J=4.8 Hz), 127.9 (d, J=9.7 Hz), 128.3 (d, J=12.3 Hz), 128.5 (d, J=12.5 Hz), 131.2 (d, J=10.2 Hz), 131.5 (d, J=2.8 Hz), 131.9 (d, J=2.6 Hz), 132.7, 133.2, 133.3, 133.7, 134.3, 135.4, 141.9 (d, J=7.2 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 31.328. HPLC: Column: ChiralpackAD-3, 4.6×150 mm; IPA: Heptane (25:75), 1.0 ml/min, 220 nm, r t =6.2 min, 11.0 min.
Examples 11 and 12
Scheme 10 below describes a method of making the compounds of then invention by reacting cyclic intermediate 2a with (2′,6′-dimethoxybiphenyl-2-yl)magnesium bromide to provide the compound 5b followed by reaction with a lithium alkyl to provide a compound of the invention (denoted as compound 6).
Specific compound of the invention prepared according to Scheme 10 are described in Table 5.
TABLE 5
Synthesis of chiral phosphine oxides 6k and 6l.
Entry
R 2 M
Product
ee
yield
Ex. 12
CH 3 MgCl
>99.9:0.1
61%
Ex. 13
Fc—Li
98.9:1.1
59%
Example 12
Synthesis of 6k
A solution of (5c, 0.05 g, 0.075 mmol) in anhydrous THF (5 ml) is stirred at room temperature under argon atmosphere. Methyl magnesium chloride (0.12 ml, 0.377 mmol, 3.0 M in THF) is added dropwise to the reaction mixture and stirred at room temperature. The reaction is completed in 2 hours. The 2 ml of saturated ammonium chloride solution is added is quenched the reaction and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated and purified on column to provide 6k (16 mg, 61% yield) in >99.9:0.1 er. 1 H NMR (400 MHz, CDCl 3 ) δ 1.67 (d, J=13.7 Hz, 3H), 3.14 (s, 3H), 3.62 (s, 3H), 6.23 (d, J=8.5 Hz, 1H), 6.50 (d, J=8.5 Hz, 1H), 7.06-7.11 (m, 1H), 7.19-7.38 (m, 6H), 7.48-7.58 (m, 2H), 8.27-8.33 (m, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 14.9, 15.7, 54.8, 55.3, 103.1 (d, J=37.6 Hz), 117.6, 127.2 (d, J=11.2 Hz), 127.7 (d, J=11.0 Hz), 129.8, 130.3 (d, J=9.9 Hz), 130.6 (d, J=2.7 Hz), 131.6 (d, J=2.6 Hz), 131.9 (d, J=10.6 Hz), 132.9, 133.1 (d, J=8.3 Hz), 133.9, 134.5, 135.5, 137.6 (d, J=9.5 Hz), 157.7 (d, J=14.6 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 30.073. HPLC: Column: ChiralpackIA-3, 4.6×150 mm; IPA: Heptane (12:88), 1.5 ml/min, 220 nm, r t =12.2 min, 15.2 min.
Example 12
Synthesis of 61
A solution of (5c, 0.1 g, 0.151 mmol) in anhydrous THF (5 ml) is cooled to −78° C. under argon atmosphere. Then freshly prepared FcLi (85.1 mg, 0.453 mmol) is added dropwise to the reaction mixture and stirred at −78° C. The reaction is completed in 30 minutes. Then that the reaction is quenched using 2 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated and purified to provide 6l (47 mg, 59% yield) in 98.9:1.1 er. 1 H NMR (400 MHz, CDCl 3 ) δ 3.15 (s, 3H), 3.70 (s, 3H), 3.94 (s, 5H), 3.97-3.99 (m, 1H). 4.29-4.32 (m, 1H), 4.37-4.40 (m, 1H), 4.68-4.70 (m, 1H), 6.05 (d, J=8.0 Hz, 1H), 6.46 (d, J=8.4 Hz, 1H), 7.05-7.14 (m, 2H), 7.26-7.34 (m, 3H), 7.37-7.43 (m, 1H), 7.45-7.56 (m, 4H). 13 C NMR (100 MHz, CDCl 3 ) δ 54.5, 55.7, 69.5, 70.8 (d, J=10.1 Hz), 71.3 (d, J=10.2 Hz), 71.6 (d, J=13.3 Hz), 73.1 (d, J=10.8 Hz), 73.6, 74.8, 102.2, 103.5, 126.3 (d, J=12.3 Hz), 127.2 (d, J=12.2 Hz), 129.2, 130.3 (d, J=2.8 Hz), 130.7 (d, J=9.9 Hz), 131.3 (d, J=2.5 Hz), 132.4 (d, J=10.1 Hz), 133.6 (d, J=11.0 Hz), 133.8, 133.9, 134.8, 135.0, 139.0 (d, J=8.3 Hz), 156.9, 158.3. 31 P NMR (162 MHz, CDCl 3 ) δ 27.414. HPLC: Chiral AGP, 4.0×150 mm; mobile phase: A: pH5 buffer MB: ACN; isocratic: 79/21 A/B, 1.1 ml/min, 220 nm, r t =4.0 min, 5.3 min.
Example 13
Synthesis of 6m
A solution of 5c (0.150 g, 0.265 mmol) in anhydrous THF (4 ml) is stirred under argon atmosphere at −10° C. temperature. Methyl magnesium chloride (0.35 ml, 1.06 mmol, 3.0 M in THF) is added dropwise to the reaction mixture and stirred for 15 minutes at −10 C, and then slowly warm to room temperature and stirred for 3-4 hrs. Once starting material is all consumed, the reaction is quenched using 2 ml of saturated ammonium chloride solution and then extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated, and purified on column to provide 6m (0.050 g, 73% yield) in 98.6:1.3 er. 1 H NMR (400 MHz, CDCl 3 ) δ 2.10 (d, J=13.0 Hz, 3H), 2.29 (s, 3H), 2.40 (s, 6H), 7.39-7.48 (m, 3H), 7.56-7.63 (m, 2H), 6.88-6.91 (m, 2H); 13 C NMR (100 MHz, CDCl 3 ) δ 19.9, 20.6, 21.0 (d, J=1.3 Hz), 125.4, 126.4, 128.8 (d, J=11.9 Hz), 129.5 (d, J=10.3 Hz), 131.1 (d, J=11.1 Hz), 131.2 (d, J=11.2 Hz), 136.9, 137.9, 141.6 (d, J=2.5 Hz), 142.7 (d, J=10.4 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ: 34.594 ppm. Chiral HPLC: ChiralpackAD-3, 4.6×150 mm; IPA: Heptane (25:75); 1.5 ml/min, 220 nm, r t =3.0 min and 3.9 min.
Example 14
Synthesis of 6n
A solution of (5c, 0.2 g, 0.353 mmol) in anhydrous THF (5 ml) is cooled to −78° C. under argon atmosphere. A solution of FcLi (0.229 g, 1.23 mmol) is added to the reaction mixture and stirred for 1 hour at −78 C and then brought to 0° C. over 30 minutes. After the reaction completion, 2 ml of saturated ammonium chloride solution is added to quench the reaction and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated, purified on column to provide 6n (87 mg, 58%) and 99:1 er. 1 H NMR (400 MHz, CDCl 3 ) δ 2.16 (s, 6H), 2.24 (s, 3H), 3.97-4.0 (m, 1H), 4.27 (s, 5H), 4.36-4.39 (m, 1H), 4.50-4.52 (m, 1H), 4.69-4.72 (m, 1H), 6.79 (d, J=3.6 Hz, 2H), 7.43-7.52 (m, 3H), 7.70-7.76 (m, 2H). 13 C NMR (100 MHz, CDCl 3 ) δ 20.9 (d, J=1.3 Hz), 24.0, 24.1, 71.0, 71.6, 71.8, 72.6, 72.8, 73.2, 73.4, 128.0, 128.2, 131.0 (d, J=10.1 Hz), 131.1 (d, J=10.2 Hz), 141.0 (d, J=2.5 Hz), 142.8 (d, J=10.4 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ: 30.108. Chiral HPLC: ChiralpackAD-3, 4.6×150 mm; IPA: Heptane (25:75); 1.5 ml/min, 220 nm, r t =3.0 min and 3.9 min.
Example 15
Synthesis of 6o
Step 1: Synthesis of 2b
A solution of (1, 2.0 g, 6.414 mmol) in anhydrous dichloromethane (20 ml) is cooled to −10° C. and then methyl phosphonic dichloride (1.01 g., 7.69 mmol), is added to the reaction mixture. And 1-methyl imidazole (1.0 ml, 16.053 mmol) is added to the reaction mixture over 10 minutes time while maintaining reaction temperature <−10° C. under argon atmosphere. The starting material is consumed in about 2 hours after addition of base and stirring the reaction mixture below <0° C. The reaction is quenched using 10 ml of water and extracted. Organic phase is washed with 10 ml of 1N HCl. The organic phase is then filtered through Celite and then concentrated. The residue is recrystallized using isopropanol: water to provide 2b (1.8 g, 75.6% yield) as a white solid. 1 H NMR (400 MHz, CDCl 3 ) δ 2.07 (d, J=17.5 Hz, 3H), 2.42 (s, 3H), 4.43 (dd, J=10.6, 15.5 Hz, 1H), 4.67 (dd, J=10.6, 15.4 Hz, 1H), 7.03-7.09 (m, 1H), 7.28-7.34 (m, 2H), 8.01 (d, J=8.4 Hz, 2H). 13 C NMR (100 MHz, CDCl 3 ) δ 15.5, 16.8, 21.8, 46.6, 120.4 (d, J=5.4 Hz), 126.1 (d, J=6.2 Hz), 127.1 (d, J=1.1 Hz), 128.3, 130.1, 130.2, 130.4, 135.2, 145.2, 147.6 (d, J=9.4 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 24.5
Step 2: Synthesis of (R)-4-chloro-2-((S)-1-(4-methylphenylsulfonamido)ethyl)phenyl 2-methoxyphenyl(methyl)phosphinate (5d)
A solution of 2b (2.0 g, 5.19 mmol) in anhydrous THF (25 ml) is cooled to −20° C. under argon atmosphere. Then 2-methoxy phenyl magnesium bromide (5.71 ml, 5.71 mmol, 1.0 M in THF) is added dropwise to the reaction mixture and stirred for 2 hours at −20° C. After the starting material is consumed, the reaction is quenched using 20 ml of saturated ammonium chloride solution and extracted using 100 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated, and purified on column to provide 5d (2.4 g, 92%) in >99:5:0.5 dr. 1 H NMR (400 MHz, CDCl 3 ) δ 1.3 (d, J=7.1 Hz, 3H), 1.98 (d, J=15.3 Hz, 3H), 2.27 (s, 3H), 4.04 (s, 3H), 4.56-4.66 (m, 1H), 6.07-6.25 (m, 1H), 6.83-6.88 (m, 1H), 6.94 (d, J=7.3 Hz, 2H), 7.02-7.15 (m, 3H), 7.36-7.41 (m, 2H), 7.61 (t, J=8.1 Hz, 1H), 8.0 (ddd, J=1.7, 7.4 Hz, 1H). 13 C NMR (400 MHz, CDCl 3 ) δ 15.9, 16.9, 21.3, 22.3, 50.5, 50.6, 56.1, 111.3, 111.4, 117.1, 118.3, 121.0, 121.1, 126.8, 127.9, 128.4, 129.1, 133.9, 135.2, 135.5, 135.5, 137.5, 142.9, 146.9, 147.0, 160.3, 160.4. 31 P NMR (162 MHz, CDCl 3 ) δ 42.044.
Step 3. Synthesis of 6o
A solution of (5d, 0.2 g, 0.405 mmol) in anhydrous THF (5 ml) is cooled to −78° C. under argon atmosphere. Then freshly prepared FcLi (230 mg, 1.21 mmol) is added dropwise to the reaction mixture and stirred at −78° C. The reaction is completed in 30 minutes. The reaction is quenched using 2 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate, concentrated, and purified on column to provide 6o (119 mg, 82%) in 98.8:1.2 er. 1 H NMR (400 MHz, CDCl 3 ) δ 1.99 (d, J=13.8 Hz, 3H), 3.80 (s, 3H), 4.27 (s, 5H), 4.38 (s, 2H), 6.85-6.90 (m, 1H), 7.07 (t, J=7.5 Hz, 1H), 7.45 (t, J=8.1 Hz, 1H), 7.90-7.99 (m, 1H); 13 C NMR (100 MHz, CDCl 3 ) δ 55.3, 69.6, 71.2, 71.9, 77.4, 110.8, 121.0 (d, J=9.7 Hz), 133.4, 133.6, 159.8. 31 P NMR (162 MHz, CDCl 3 ) δ 29.246. HPLC: Chiralpack OJ_RH, 4.6×150 mm; 1% acetic acid in water, pH=4.5 adjusted with NH4OH; MB:ACN; isocratic: 45/55 A/B; 1.2 ml/min; 220 nm, r t =2.1, 4.1 min.
Example 16
Synthesis of 6p
Step 1: Synthesis of 5e
A solution of 2c (0.5 g, 0.984 mmol) is dissolved in anhydrous THF (5 ml) cooled to −78° C. under argon atmosphere. Freshly prepared FcLi (223 mg, 1.18 mmol) is added dropwise to the reaction mixture and stirred at −78° C. The reaction is completed in 20 minutes. Then the reaction is quenched using 2 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate, concentrated, and purified on column to provide 5e (560 mg, 82% yield). 1 H NMR (400 MHz, CDCl 3 ) δ 1.55 (d, J=6.9 Hz, 3H), 2.27 (s, 3H), 3.81 (s, 6H), 4.32 (s, 5H), 4.43-4.51 (m, 3H), 4.61 (bs, 1H), 4.78 (bs, 1H), 5.99 (d, J=9.6 Hz, 1H), 6.50 (d, J=2.7 Hz, 1H), 6.62 (dd, J=5.1, 8.6 Hz, 2H), 6.87-6.92 (m, 3H), 7.24-7.28 (m, 2H), 7.45 (t, J=8.4 Hz, 1H). 7.68 (d, J=8.9 Hz, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 14.4, 21.2, 21.5, 22.5, 52.2, 56.7, 60.6, 70.2, 71.0 (d, J=12.2 Hz), 71.4 (d, J=13.8 Hz), 72.1 (d, J=19 Hz), 72.5 (d, J=12.2 Hz), 73.1, 74.7, 105.4 (d, J=7.4 Hz), 107.0, 108.4, 121.3 (d, J=4.3 Hz), 127.0, 127.9, 128.2, 128.6, 129.3, 132.8 (d, J=7.3 Hz), 135.3, 137.5, 143.1, 148.5 (d, J=7.9 Hz), 163.4 (d, J=1.6 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 33.346.
Step 2: Synthesis of 6p
A solution of 5e (0.1 g, 0.144 mmol) in anhydrous THF (5 ml) is cooled to 0° C. under argon atmosphere. Methyl magnesium chloride (0.25 ml, 0.722 mmol, 3.0 M in THF) is added dropwise to the reaction mixture and stirred for 3 hrs at 0° C. After the completion of the reaction, 1 ml of saturated ammonium chloride solution is added to quench the reaction and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated, and purified on column to provide 6p (47 mg, 86% yield) in 99:1 er. 1 H NMR (400 MHz, CDCl 3 ) δ 2.10 (d, J=14.3 Hz, 3H), 3.71 (s, 6H), 4.25-4.27 (m, 1H), 4.30 (s, 5H), 4.31-4.33 (m, 1H), 4.36-4.38 (m, 1H), 4.69-4.71 (m, 1H), 6.48 (dd, J=4.1, 8.5 Hz, 2H), 7.29 (t, J=8.5 Hz, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 20.1, 20.9, 55.8, 69.7, 70.2, 70.4 (d, J=5.2 Hz), 70.5, 70.8, 71.0, 78.1, 79.3, 104.7 (d, J=6.2 Hz), 111.1, 112.1, 133.5, 162.3. 31 P (162 MHz, CDCl 3 ) δ 28.745. HPLC: Column: ChiralpackAD-H, 4.6×250 mm; IPA: Heptane (2:98), 1.0 ml/min, 220 nm, r t =11.1 min, 12.1 min.
Example 17
Synthesis 6q
Step 1: Synthesis of 5f
A solution of 2c (1.0 g, 1.97 mmol) in anhydrous THF (30 ml) is heated to 45° C. to dissolve the compound and cooled to −45° C. under argon atmosphere. t-BuLi (2.5 ml, 3.94 mmol, 1.6 M in pentane) is added dropwise to the reaction mixture and stirred for 30 minutes at −45° C. After the starting material is consumed, the reaction is quenched using 10 ml of saturated ammonium chloride solution, extracted using 50 ml of ethyl acetate, and dried over sodium sulphate. The organic solvent is removed and residue purified on column to provide 5f (0.770 g, 70%) in >99:1 dr. 1 H NMR (400 MHz, CDCl 3 ) δ 1.3 (d, J=17.4 Hz, 9H), 1.44 (d, J=6.9 Hz, 3H), 2.31 (s, 3H), 3.66 (s, 6H), 4.89-4.98 (m, 1H), 5.74 (d, J=7.7 Hz, 1H), 6.53-6.59 (m, 2H), 6.77-6.82 (m, 1H), 6.95-6.98 (m, 1H), 7.04 (d, J=8.9 Hz, 1H), 7.12 (d, J=8.1 Hz, 2H), 7.44 (t, J=8.3 Hz, 1H), 7.60 (d, J=8.2 Hz, 2H). 13 C NMR (100 MHz, CDCl 3 ) δ 21.3, 22.9, 24.4, 34.8, 35.9, 48.7, 56.0, 104.6 (d, J=7.0 Hz), 119.0 (d, J=5.5 Hz), 126.8, 126.9, 127.4, 127.8, 129.5, 133.0 (d, J=6.8 Hz), 135.1, 137.2, 143.1, 147.8 (d, J=9.8 Hz), 163.4 (d, J=1.8 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 48.419.
Step 2: Synthesis of 6q
A solution of 5f (0.70 g, 1.23 mmol) in anhydrous THF (10 ml) is added MgBr2.OEt2 (0.063 g, 0.247 mmol) and stirred at rt for about 30 minutes. Then methyl lithium (2.70 ml, 4.32 mmol, 1.6 M in pentane) is added dropwise to the reaction mixture and stirred for 30 minutes at rt. After the starting material is consumed, the reaction is quenched using 5 ml of saturated ammonium chloride solution and extracted using 50 ml of ethyl acetate. The organic layer is dried over sodium sulphate, concentrated, and purified on column to provide 6p (0.2 g, 63%) in 98.2:1.7 er. 1 H NMR (400 MHz, CDCl 3 ) δ 1.15 (d, J=15.5 Hz, 9H), 1.80 (d, J=13.2 Hz, 3H), 3.81 (s, 6H), 6.57 (dd, J=3.8, 8.3 Hz, 2H), 7.38 (t, J=8.3 Hz, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 15.6, 16.3, 24.5 (d, J=1.6 Hz), 34.3, 35.0, 55.7, 104.5 (d, J=5.9 Hz), 103.6, 163.2. 31 P NMR (162 MHz, CDCl 3 ) δ 51.210;
Scheme 11 below describes an alternative method of making the compounds of the invention (denoted as compound 6) by reacting compounds of formula (IIa) with organometallic reagents.
TABLE 6
Synthesis of chiral phosphine oxides from 1,2-amino alcohol templates.
Entry
R 1 M
yield (11)
R 2 M
Product
er
yield
Ex. 18 Ex. 19
91% (11a)
MeMgBr MeLi
99:1 90:10
38% 70%
Ex. 20
tBuLi
98:2
51%
Ex. 21 5
47% (11b)
MeLi
93:7
55%
Ex. 22 7
tBuLi (4) tBuMgCl
62% (11c)
MeMgBr MeLi
no reaction nd
42%
Synthesis of 10
A solution of (1R, 2S)—N-tosyl-norephedrine (120 g) in CH2C12 (800 mL) is cooled to −20° C. and then PhP(O)Cl 2 (1.3 eq) is added, followed by 1-Me-imidazole (2.5 eq), and the mixture is stirred and slowly warmed to room temperature and stirred overnight. After the completion of the reaction, the mixture is filtered to remove the solid. Then the organic phase is washed with brine, aqueous NaHCO3 solution, and 1 N HCl (150 mL). The to organic phase is dried and concentrated. The residue is recrystallized from ethyl acetate/hexane (1:2, v/v) twice to provide 10 (125 g) in 75% yields.
Synthesis of (R)-((1R,2S)-2-(4-methylphenylsulfonamido)-1-phenylpropyl) 2-methoxyphenyl(phenyl)phosphinate (11a)
A solution of 10 (2.0 g, 5.12 mmol) in anhydrous THF (40 ml) is cooled to −40° C. under argon atmosphere. Then 2-methoxy phenyl magnesium bromide (6.15 ml, 6.15 mmol, 1.0 M in THF) is added dropwise to the reaction mixture. During addition, the temperature rises to about −30° C. The mixture is stirred for 1 hour at −30° C., quenched using 5 ml of saturated ammonium chloride solution, and extracted using 100 ml of ethyl acetate. The organic layer is dried over sodium sulphate and concentrated. The residue is purified on A silica column to provide 11a (2.2 g, 91%) in optically pure form. 1 H NMR (400 MHz, CDCl 3 ) δ 1.08 (d, J=6.8 Hz, 3H), 2.31 (s, 3H), 3.52-3.61 (m, 1H), 3.77 (s, 3H), 4.85 (d, J=9.4 Hz, 1H), 6.93-6.99 (m, 1H), 7.06-7.15 (m, 5H), 7.21-7.35 (m, 6H), 7.43-7.49 (m, 1H), 7.54-7.60 (m, 1H), 7.63-7.72 (m, 4H), 7.95-8.02 (m, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 14.4, 21.4, 54.9 (d, J=2.5 Hz), 55.5, 80.4 (d, J=5.9 Hz), 111.7 (d, J=8.0 Hz), 118.1, 119.5, 120.9 (d, J=12.9 Hz), 125.5, 127.0, 127.8, 128.0, 128.1, 128.3, 129.4, 129.7, 131.4, 132.0, 132.1 (d, J=3.1 Hz), 134.4 (d, J=6.7 Hz), 134.9 (d, J=1.9 Hz), 138.0 (d, J=5.6 Hz), 138.5, 142.7, 160.7 (d, J=4.2 Hz). 31 P NMR (162 MHz, CDCl 3 ) δ 33.648.
Synthesis of 11b
Step 1. Synthesis of 11b: A solution of 10 (2.0 g, 4.68 mmol) in anhydrous THF (30 ml) is stirred at room temperature under argon atmosphere. Then 2-mesityl magnesium bromide (7.0 ml, 7.02 mmol, 1.0 M in THF) is added dropwise to the reaction mixture. After stirring at room temperature for about 1 hour, the reaction is quenched using 10 ml of saturated ammonium chloride solution and extracted using 100 ml of ethyl acetate. The organic layer is dried over sodium sulphate, concentrated, and the residue is purified on silica column to provide 11b (1.2 g, 47%) in optically pure form. 1 H NMR (400 MHz, CDCl 3 ) δ 1.10 (d, J=6.8 Hz, 3H), 2.34 (s, 3H), 2.4 (s, 3H), 2.5 (s, 6H), 3.51-3.65 (m, 1H), 5.18 (dd, J=1.8, 10.3 Hz), 6.92 (d, J=4.3 Hz, 1H), 6.96-6.98 (m, 2H), 7.16-7.25 (m, 8H), 7.37-7.47 (m, 3H), 7.81 (d, J=8.3 Hz, 2H) 13 C NMR (100 MHz, CDCl 3 ) δ 15.1, 21.1 (d, J=1.2 Hz), 21.5, 54.8 (d, J=1.3 Hz), 81.6 (d, J=6.1 Hz), 123.3, 124.7, 126.1, 127.2, 128.0, 128.2, 128.3, 128.4, 130.9 (d, J=4.5 Hz), 131.0 (d, J=1.8 Hz), 131.8 (d, J=3.0 Hz), 132.2, 133.5, 137.7 (d, J=6.2 Hz), 138.5, 142.5 (d, J=3.0 Hz), 142.8, 142.9, 143.0. 31 P NMR (162 MHz, CDCl 3 ) δ 40.844.
Synthesis of 11c:
A solution of 10 (1 g, 2.34 mmol) in anhydrous THF (15 ml) is cooled to −70° C. under argon atmosphere. And t-BuLi (1.60 ml, 2.57 mmol, 1.6 M in pentane) is added dropwise to the reaction mixture and stirred for 30 minutes at −70° C. After the reaction completion, the reaction is quenched using 5 ml of saturated ammonium chloride solution and extracted using 50 ml of ethyl acetate. The organic layer is dried over sodium sulphate, concentrated, and the residue is purified on silica column to provide 11c (0.68 g, 62%) in optically pure form. 1 H NMR (400 MHz, CDCl 3 ) δ 1.08 (d, J=6.9 Hz, 3H), 1.22 (d, J=16.1 Hz, 9H), 2.24 (s, 3H), 3.47-3.55 (m, 1H), 4.61 (d, J=8.9 Hz, 1H), 6.98-7.05 (m, 4H), 7.28-7.36 (m, 5H), 7.43-7.55 (m, 3H), 7.74 (d, J=8.2 Hz, 2H), 7.82 (d, J=9.6 Hz, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ 14.0, 21.4, 24.3, 32.4, 33.4, 55.0, 80.9 (d, J=8.2 Hz), 125.2, 125.3, 126.5, 127.0, 128.1, 128.3, 126.5, 127.0, 128.1, 128.3, 128.4, 128.6, 129.3, 132.5 (d, J=2.8 Hz), 133.3 (d, J=7.1 Hz), 133.3 (d, J=9.3 Hz), 138.2 (d, J=7.1 Hz), 138.7, 142.5. 31 P NMR (162 MHz, CDCl 3 ) δ 56.157.
Example 18
Synthesis of 6a from 11a with MeMgCl
A solution of 11a (0.5 g, 0.936 mmol) in anhydrous THF (10 ml) is stirred under argon atmosphere at room temperature. And then methylmagnesium chloride (1.87 ml, 5.61 mmol, 3.0 M in THF) is added dropwise to the reaction mixture and stirred for 8 hours at room temperature. The reaction mixture is quenched using 2 ml of saturated ammonium chloride solution and extracted using 50 ml of ethyl acetate. The organic layer is dried over sodium sulphate, concentrated, and purified on column to provide 6a (90 mg, 38% yield) in 99:1 er.
Example 19
Synthesis of 6a from 11a with MeLi
A solution of 11a (0.2 g, 385 mmol) in anhydrous THF (5 ml) is stirred under argon atmosphere at −78° C. temperature. Methyl lithium (1.0 ml, 1.54 mmol, 1.6 M in Et 2 O) is added dropwise to the reaction mixture and stirred for 15 minutes at −78 C. The reaction is quenched using 2 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate, concentrated, and purified on column to provide 6a (58 mg, 55% yield) in 85:15 er.
Example 20
Synthesis of 6b from 11a
A solution of 11a (0.2 g, 385 mmol) in anhydrous THF (5 ml) is stirred under argon atmosphere at −78° C. temperature. Then t-butyllithium (1.0 ml, 1.54 mmol, 1.6 M in Pentane) is added dropwise to the reaction mixture and stirred for 15 minutes at −78 C. The reaction is quenched using 2 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate, concentrated, and purified on column to provide 6b (58 mg, 51% yield) in 98:2 er.
Example 21
Synthesis of 6m from 11b
Procedure: A solution of 11b (0.1 g, 0.182 mmol) in anhydrous THF (5 ml) is stirred under argon atmosphere at −30° C. temperature. Methyl lithium (1.0 ml, 0.639 mmol, 1.6 M in Et 2 O) is added dropwise to the reaction mixture and stirred for 15 minutes at −30 C. The reaction is quenched using 2 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate, concentrated, and purified on silica column to provide 6m (26 mg, 55% yield) in 93:7 er. 1 H NMR (400 MHz, CDCl 3 ) δ 2.10 (d, J=13.0 Hz, 3H), 2.29 (s, 3H), 2.40 (s, 6H), 7.39-7.48 (m, 3H), 7.56-7.63 (m, 2H), 6.88-6.91 (m, 2H). 13 C NMR (100 MHz, CDCl 3 ) δ 14.1, 14.8, 19.8, 20.5, 21.0, 23.5, 23.6, 127.6, 127.7, 128.3, 128.4, 128.6, 128.7, 129.4, 129.5, 130.4, 130.5, 131.0, 131.2, 131.3, 141.5, 142.6, 142.7. 31 P NMR (162 MHz, CDCl 3 ) δ: 34.778. Chiral HPLC: ChiralpackAD-3, 4.6×150 mm; IPA: Heptane (25:75); 1.5 ml/min, 220 nm, r t =3.3 min and 4.3 min.
Example 22
Synthesis of 6r from 11c
A solution of 11c (0.2 g, 0.412 mmol) in anhydrous THF (5 ml) is stirred under argon atmosphere at −10° C. temperature. Methyl lithium (0.77 ml, 1.23 mmol, 1.6 M in Et 2 O) is added dropwise to the reaction mixture and stirred for 15 minutes at −10 C. The reaction is quenched using 2 ml of saturated ammonium chloride solution and extracted using 30 ml of ethyl acetate. The organic layer is dried over sodium sulphate, concentrated, and purified on column to provide 6r (35 mg, 43% yield). 1 H NMR (400 MHz, CDCl 3 ) δ 1.13 (d, J=14.9 Hz, 9H), 1.73 (d, J=12.1 Hz, 3H), 7.44-7.59 (m, 3H), 7.69-7.75 (m, 3H). 31 P NMR (162 MHz, CDCl 3 ) δ: 47.623. | Disclosed are methods for making chiral phosphorus ligands including chiral phosphines, chiral phosphine oxides, phosphonamides, and aminophosphines. The chiral phosphorus ligands prepared by the methods of the invention are useful as components of chiral catalysts, e.g., transition metal complexes. | 2 |
FIELD OF THE INVENTION
This invention pertains to gas distribution devices for hydrocarbon processes. More specifically, this invention relates to a device for uniformly distributing gas over a bed of fluidized solids.
BACKGROUND OF THE INVENTION
Processes employing beds of fluidized solids in modes of fluidized suspension or fluidized transport are well known. A particularly well known example of such a process is the fluidized catalytic cracking (FCC) process for the conversion of gas oils and heavier boiling hydrocarbons into lighter hydrocarbons. In most applications where a large diameter vessel or conduit confines the fluidized particles, it is essential that a good distribution of the gaseous fluidizing medium be obtained over the entire cross-section of the vessel or conduit. Good distribution of gas is necessary to evenly convey the particles when the fluidized bed is in a transport mode. Moreover, the introduction of a gas reactant, typically air, into the bed of fluidized particles increases the demand for even air distribution. A poor distribution of air promotes variations in the reaction rates over different portions of the confinement vessel which can lead to incomplete reactions and a non-uniform temperature profile. This is particularly true when operating a dense fluidized bed.
FCC units typically include a regenerator, many of which maintain a dense fluidized bed of catalyst particles through which a regeneration gas, such as air, passes to combust coke. The coke forms as a by-product of the cracking operation, and its removal regenerates the catalyst. A common regenerator arrangement introduces a regeneration gas, or air, into the bottom of the regenerator through the bottom closure of the regenerator vessel. The air distribution device divides the air and injects it into the catalyst bed at a multiplicity of points in order to obtain good air distribution. As long as there is no need to withdraw catalyst particles from below the point of air introduction, a simple air distribution device such as a perforated plate or dome over an air chamber will provide efficient and reliable air distribution for the regenerator.
However, the configuration of some FCC process flow arrangements require the removal of catalyst through the bottom closure of the regenerator. The need to withdraw catalyst from the bottom closure of the regenerator complicates the design of the air distribution device. The design of a reliable air distribution device is further complicated by regenerator operating temperatures that normally exceed 705° C. (1300° F.). These temperatures greatly reduce the strength of the materials from which the air distribution devices can be fabricated.
A variety of distribution device designs have been used that will permit the introduction of air and the withdrawal of catalyst from the bottom of the regenerator. One design was the modification of a full plate or dome type air distribution device to include a conduit that extended through the air distribution chamber and communicated a catalyst withdrawal point on the bottom closure with a collection point above the top dome or plate. In this arrangement, the conduit pierced the dome or plate. In order to prevent air leakage around and catalyst movement through the opening for the conduit, a seal bridged the opening between the outer conduit wall and the plate or dome. Catalyst induced erosion and the accumulation of fine catalyst particles made this seal prone to failure. Providing the catalyst collection area above the grid also blocked a significant portion of the distributor cross-section thereby interfering with air distribution.
In order to avoid the problems associated with the seal and to allow free passage of solid particles to a withdrawal point located below the point of air distribution, distribution devices consisting of a planar network or grid of horizontal pipe sections with air outlet nozzles spaced along the pipes have been used. Structural difficulties are often encountered with these pipe type grids. Such problems include weld cracking, metal erosion and warping of pipe sections, as well as the complete detachment or loss of pipe components. Although attempts were made to strengthen the pipe type grid, failure of stronger pipe components still occurred. The inability of stronger pipe components to remedy the problems is believed to stem from the fact that stresses which cause pipe warpage and cracking are typically generated by temperature differentials over the pipe components. Thus, strengthening the grid only serves to intensify the stresses and exacerbate the problems.
Cognizant of the fact that at least some of the stresses leading to failure of air grid components are thermally induced, more flexible designs for air distribution devices have been sought. One such design uses a combination of a dome and radially extending pipe branches to distribute air over the entire regeneration cross-section. This design provides flexibility by using, as a dome, a shallow dish head having a diameter smaller than the diameter of the regenerator vessel. The dome is often supported by a frusto-conical reducer section which decreases the diameter of the dome down to a smaller diameter section which is attached to the bottom of the regenerator closure. A relatively thin wall section and gradual taper of the frusto-conical section provide flexibility to allow for differential thermal expansions in the dome and reducer sections which are induced by temperature gradients and varying expansion rates. The reducer section allows an open space to be maintained between the outside diameter of the frusto-conical section and the end closure of regenerator so that fluidized particles can flow around the dome and into a catalyst withdrawal point. An evenly spaced series of orifices or nozzles distributed over the top of the dome distribute air uniformly over the cross-section of the regenerator lying above the dome.
The remaining cross-section of the regenerator, which is not above the dome, receives a uniformly distributed flow of air through the radially extending pipe branches. Orifices or nozzles are spaced along the branch pipes to provide outlets for the air. The pipe branches project from a cylindrical band which extends vertically and is located between the dome and frusto-conical section. Geometric discontinuities such as sharp corners or junctions between connecting components will multiply the magnitude of thermally or pressure induced stresses. In order to avoid such discontinuities between the vertical band, dome or reducer section, a large radius transition section or knuckle is provided at such junctions. Although the dome and branch pipe style air distribution device did alleviate some of the structural problems generally associated with the air distributors, small cracks in the junction between the band and the dome, and the band and the branch arms persisted in some cases. In addition, erosion of the dome and pipe arm material continued to be a problem. One source of the erosion appeared to be the result of a differential pressure between the outlets on the top of the dome and the outlets on the branch arms which aspirated catalyst into the interior of the dome through the branch arm openings and out through the holes on the dome.
A new attachment arrangement has been discovered for connecting the pipe branches in a dome and pipe branch type air distribution device. This new connection alleviates the cracking problems sometimes associated with the band to dome and band to branch pipe junction while also raising the elevation of the pipe arm outlets relative to the dome outlets so that the beforementioned aspiration of solid particles will not occur.
SUMMARY OF THE INVENTION
This invention is an improvement to a gas distribution device wherein the gas distribution device comprises a central dome and a series of radially projecting pipe branches for uniformly distributing gas over the cross-section of fluidized bed of particles while allowing particles to flow below the point of gas distribution. The improvement is the use of extruded connections that have an outwardly and upwardly extending segment to attach the pipe branches to a knuckle section located between the dome and its supporting member. Placing the extruded connection or extrusion in the knuckle section of the distribution device raises the elevation of the pipe branches with respect to the dome. The outlet of the extrusion will have a center line projecting at some upward angle with respect to the horizontal plane of the outlet openings. The use of a pipe elbow or bend to bring the center line projection of the outlet back to a horizontal orientation will further increase the relative height of the pipe branches with respect to the elevation of the dome outlet. The extruded outlet of the knuckle also provides a smooth geometric transition from the knuckle to pipe branch connections and alleviates stress risers that have contributed to the cracking problems of past air distributor designs. At the same time, the pipe branch connection of this invention relieves erosion problems by locating the outlets of the dome and pipe branches at a closer elevation.
Accordingly, it is an object of this invention to provide a reliable device for evenly distributing gas over a bed of solid particles.
It is a further object of this invention to improve the structural integrity of an air distribution device for distributing air in an FCC regenerator.
It is a more specific object of this invention to reduce cracking and erosion problems associated with a dome and pipe branch type air distribution device used in an FCC regenerator.
In one embodiment, this invention comprises an improved gas distribution device for distributing gas over a bed of fluidized solid particles. The gas distributor consists of a perforated central head having a predetermined arrangement of air distribution holes extending therethrough, and means for both supporting the head and conveying a fluidizing gas through an interior portion of the head. The means for supporting the head includes a toroidal knuckle attached to the outer periphery of the head. A series of radially and horizontally extending pipe branches are connected to the means for supporting the head and communicate with the interior of the head. The pipe branches also distribute fluidizing gas to the bed of solid particles. The gas distributor design is improved by the knuckle having a series of pipe branch connections formed therein. Each pipe branch connection has an outlet that communicates with the interior of the head and through which a pipe branch is attached to the connection. In order to improve the structural integrity of the device, the geometry of each pipe branch connection consists of continuous curves.
Other objects, embodiments, and details of this invention will be apparent from the following detailed description of the preferred embodiment. The description of this invention in the context of a preferred embodiment is not intended to restrict the scope of the claims to the details disclosed therein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a cross-section of an FCC regenerator.
FIG. 2 depicts a vertical section of the air distribution device of this invention.
FIG. 3 is an alternate detail for the air distribution device of this invention.
FIG. 4 is a partial plan view of the regenerator taken at Section 4--4 of FIG. 1.
FIG. 5 is an enlarged detail of the extruded connection for the pipe branch.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Looking then at FIG. 1, there is shown a regenerator 10 having a cylindrical shell 12, a top head 14, and a bottom closure 16 in the form of a conical section. Solid particles comprising spent catalyst enter regenerator 10 through a conduit 18. Compressed fluidizing gas comprising air flows through a conduit 20 and into the interior of a pipe branch type air distribution device 22. A dome 24 in the top of the air distribution device and a series of radially projecting pipe branches 26 distribute the air over the entire horizontal cross-section of the regenerator. The air rises upward and reacts with carbonaceous deposits on the catalyst, such as coke. The combustion of the carbon deposits with oxygen will produce temperatures at least above 650° C. (1200° F.) and more typically above 705° C. (1300° F.) so that the combustion produces a region of intense heat directly above the dome and pipe branches. Upward movement of the air fluidizes the catalyst above the dome and pipe branches. Air is introduced in a volume that will maintain a fluidized bed up to about confluence of conduit 18 with shell 12. As the air continues to rise, catalyst particles disengage, for the most part, and return to the dense bed of catalyst. Any catalyst that remains entrained with the air and gaseous combustion products referred to as flue gas enter a set of cyclone separators 28 through an inlet 30. Cyclone separators 28 centrifugally disengage the heavier catalyst particles from the lighter gases in two stages of separation. While the separators direct the catalyst particles downward through conduits 32 and back to the dense bed, the regeneration gases leave the regenerator through conduit 34. The regenerated catalyst particles, (i.e., those having a reduced concentration of coke as compared to the particles entering through conduit 18), pass through spaces between branch pipe 26 and are withdrawn from the regenerator vessel through regenerated catalyst conduit 36.
Further detail of the air distribution device appears in FIG. 2. The bottom of the air distribution device is a lower conduit 38 which is attached to bottom closure 16. A frusto-conical section 40 has a small end attached to the top conduit 38. A toroidal knuckle 42 connects the lower end of section 40 with the conduit 38 and another toroidal knuckle 44 connects the top of section 40 with knuckle 46 of dome 24. Toroidal knuckles 42 and 44 provide a smooth transition for the junctions of the conduit and dome with section 40. Knuckles 42 and 44 are provided with a bend radius, R 1 , of from 5 to 15% of its major toroidal diameter. The tangent lines of the knuckle or small radius section coincide with the tangent lines of the elements to which it is attached. Lower conduit 38, knuckle 42, and frusto-conical section 40 have a relatively thin wall section. Upper knuckle 44 has an increased thickness in order to provide a gradual thickness transition between the cone portion and the much thicker dome 24 and knuckle 46.
The dome 24 and knuckle 46 together provide a dished head design for the top of the air distribution device. This type of head is commonly known as a flanged and dished head. The shallow geometry for the head is chosen to minimize the difference in elevation between holes in the center of the dome and holes towards the outer edge of the dome. When the dome of the distributor has a small diameter, a flat plate section may sometimes be used for the center portion of the dome. However, when air flow through the air distribution device is stopped catalyst within the regenerator will accumulate on the top of the dome and impose a downward catalyst loading. Therefore, it is usually preferred that the dome have some arcuate shape in order to increase the strength under the downward catalyst loading. The diameter D 1 of the dome will usually equal 40-70% of the diameter D 2 of the regenerator vessel. The radius of curvature for the head R 2 is preferably between 100 and 200% of the diameter of the dome. Curvature R 3 of knuckle 46 will usually range from 5-25% of the head diameter D 1 . Dome 24 and its knuckle 46 are made substantially thicker than cone section 40. The additional thickness of the dome is provided so that the dome can support external loads, such as catalyst loading, and will contain adequate extra material to reinforce the dome around the air distribution apertures.
A predetermined pattern of air outlet openings 50 is arranged over the dome portion of the air distributor device. The distributor openings have a radial orientation along the line of radius R 2 . The size of these holes typically ranges from 1/2" to 13/4" . The openings may be simply drilled holes in the top dome or may be defined by nozzles fitted into holes within the top dome area. The nozzles serve a variety of purposes such as improving the jet characteristics of the air leaving through the nozzles and protecting the outlet opening from erosion caused by the circulation of catalyst near the outlet opening. Fluidizing gas and pressure drop requirements determine the total open area of the holes that will be required at the top of the
dome. It is usually desirable to maintain between 1/2 to 2 psi pressure drop across the dome. The diameter of the dome openings is chosen so that the dome has the required open hole area with a sufficient number of air openings to provide good distribution.
A perforated deflector plate 53 is suspended from the inside of the dome and serves to break up any large jet of fluid that may be formed by air entering through conduit 20. If uninterrupted, an air jet from conduit 20 can increase the gas pressure at the inlet of any of openings 50 located immediately above the jet thereby causing a higher air flow at the center of the grid.
Knuckle portion 46 may be formed separately and welded to the dome to form the distributor head or may be integrally formed with the head. In either case the major purpose of this knuckle is again to provide a smooth junction between the dome support member, in this case frusto-conical section 40 and the dome. In accordance with this invention, the knuckle 46 contains a series of regularly spaced pipe branch connections 48 having outlets for the attachment of the pipe branches 26. In a preferred embodiment, these connections are extruded from the material of the knuckle. The knuckle is usually made the same thickness as the dome section of the distributor. This thickness aids in the formation of extrusions 48 by providing extra material for the extrusion forming process. The extrusion can be formed by any method known to those skilled in the art of metal forming. The basic requirement for the extrusion is that knuckle and outlet be connected by material having a geometry consisting of continuous curves. A typical method of forming such extrusions uses male and female dies to progressively deform material around a drilled hole into the shape of the outlet nozzle extrusion. The branch connection opening is usually centered over the curvature of the knuckles so that the centerline of the outlet formed therein has an upward slope or upward angle. The inlet side of the extrusion nozzle communicates with the interior portion of the air distribution device. The outlet end of the extrusion supports an arcuate pipe branch section or elbow 52.
Arcuate pipe section 52 connects the upward sloping extrusion to the horizontally extending pipe branch 26. The pipe section 52 is shown in this case as a simple pipe elbow, however, a variety of pipe components can be used to provide the function of section 52. The process requirement for such components is that they provide pipe branches 26 with a sufficient horizontal elevation to allow branch pipe openings 54 to be located at an elevation close to the elevation of the dome openings. Thus, suitable elements for section 52 include lateral branch connections or a combination of an elbow and a T-section as shown in FIG. 3. The elbow 58 and the T-section 60 of FIG. 3 have the added advantage of facilitating adjustment of the branch arm elevation relative to the dome.
Each pipe branch extends horizontally to approximately the interior wall of the regenerator vessel. Air, communicated to the interior of the pipe branches enters the regenerator through openings 54 which are spaced along the bottom of the pipe branches. The openings 54 in the branch pipe have sizes generally ranging from 1/2" to 1". The openings 54 for the pipe branches use nozzles as shown in FIG. 2 and previously discussed in connection with the dome openings. The number and size of openings 54 are calculated to provide the desired volume of air addition through the branch pipes. The division of air addition between the branch pipes and the central dome is usually in ratio to the cross sectional area served by the branch pipes and the dome.
Turning then to FIG. 4, the dome and arms are shown in plan over the cross section of the regenerator. Dome openings 50 are evenly spaced from the center of dome 24 outward to approximately the upper junction of the knuckle. It is preferable to avoid having the openings 50 extend into the knuckles region of the dome in order to avoid weakening the weld at the dome to knuckle junction when such a weld is provided. In this particular arrangement the dome has a diameter equal to approximately half the diameter of the regenerator. Therefore, the area of the bed receiving fluidizing gas from the pipe branches is much greater than the area of the bed fluidized by the dome. It is, therefore, desirable to use a large number of arms circling the dome in order to provide good distribution of air over the outer diameter of the regenerator. Forming requirements that demand a minimum clearance between the extrusions limit the circumferential spacing of the pipe branches around the dome's periphery. Typically, the minimum spacing between branch pipe centerlines is twice the branch pipe diameter, with slightly larger spacings being preferred.
Additional details of the extruded connection, as set forth in FIG. 5, shows a radius R 4 on the inside of the extrusions and a radius R 5 on the outside extrusions. These radii are determined by the extrusion forming process and are preferably kept as large as possible. FIG. 5 also shows pipe elbow 52 welded to the outlet of the branch connection 48. Usually pipe elbow 52 will be a separate component since the forming of the extrusion will normally only provide a small outward extension, E 1 , of the branch connection. However, wherever possible, it would be desirable to form the extrusion and branch section 52 in one piece.
Due to the high temperatures associated with the FCC process the air distribution device is typically formed of high alloy materials. Suitable high alloy materials for the air distribution device include stainless steels, type 304H, as defined by ASTM standards, being the preferred metallurgy.
FIG. 2 shows a refractory material 56 covering almost the entire air distribution device. This refractory material is relatively thin usually having a thickness of from 1/2" to 11/2. The refractory material 56 provides erosion protection and a degree of insulation for the metal of the air distribution device and thereby evens out localized temperature gradients that could impose thermal stresses on the grid. Use of thin refractories and appropriate anchoring systems are well known in the hydrocarbon and chemical processing fields. Preferably, the refractory material is held to the air distribution device by a metal mesh or short anchors welded to the base metal of the device. | An improved air distribution device for distributing fluidizing gas to a bed of fluidized solids. The distribution device is arranged to maintain a bed of fluidized particles above a planar region of air injection and allow withdrawal of solids from below the region of air injection. The fluidizing gas is distributed to a bed of fluidized particles by a central dome and a series of horizontally extending branch pipes arranged about the periphery of the dome. In order to improve the structural integrity of the apparatus and the operation of the device, the horizontal branch pipes are attached to a knuckle region of the central dome by a series of extruded outlets that minimize stress concentrations in the branch pipe connection and locate outlet holes in the branch pipes at an elevation close to the outlet holes in the dome. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/201,759, filed May 4, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the building construction tools, and particularly to a shingle cutter which permits the on-site cutting of roofing shingles using a one-man operated machine.
2. Description of Related Art
A number of mechanical cutters and trimmers for producing fiber glass and asphalt roof shingles in a desired shape have been constructed and marketed, but most roofers have relied on a utility knife for cutting shingles in view of the knife's portability and simplicity.
Some shingle cutters are designed to produce particular kinds and shapes of shingles that are used in well-defined and specialized circumstances. For example, U.S. Pat. No. 4,951,540, issued to Cross et al., discloses a shingle ridge cap cutter used for cutting uniform sections from roof shingles. This cutter comprises a frame along which a shingle is guided under a manually operated cutter holding two blades with cutting edges positioned downward so that the cut shingle resembles a trapezoid adjoined to a rectangle so that the base of the trapezoid and a side of the rectangle coincide. Similarly, U.S. Pat. No. 5,052,256, issued to Morrissey, discloses a shingle cutting apparatus that produces a trapezoid-on-rectangle shingle used on ridge caps. The Morrissey cutter has grooves in the base into which the blades can fit.
Other patents deal with manufacturing processes that have also been applied to small scale applications. For example, U.S. Pat. No. 5,165,314, issued to Paulson et al., discloses the use of a rotating slitting blade. This devise is used to cut sheets of corrugated paperboard. Similarly, U.S. Pat. No. 5,322,001, issued to Boda, discloses a paper cutter using circular blades.
Several shingle cutters use a pivotal cutting blade. For example, U.S. Pat. No. 5,249,495, issued to Renk, discloses a pivotal cutter blade and anvil upon which the blade is mounted ins cooperation. A fence rotates in the plane of the base, so that angular cuts on a shingle can be made. Similarly, U.S. Pat. No. 5,787,781, issued to Hile, discloses a shingle cutter for cutting a straight even line and has a straight cutting edge pivotally mounted on a side and corner of the base. There is a bearing and lock nut disposed on a threaded rod and this combination keeps the blade tight against a support member recessed in the base. The base can be attached to legs.
U.S. Pat. No. 5,644,963, issued to Fountas, discloses a guide with no cutting edge.
It is apparent that no device other than a utility knife has gained wide-spread popularity for cutting and trimming shingles at the spot where the shingles are to be installed. Most of the devices are too cumbersome to be relocated on the roof or they are used only to perform specialized tasks. Recent changes in the manufacture of shingles from a single layer to a multi-layer shingle has made the hand cutting of shingles even more difficult than in the past further necessitating a cutting device which is efficient, easily portable, usable in place on a roof, and easily operated by a workman located on a roof slope.
None of the above inventions and patents, taken either singly, or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
The shingle cutter according to the present invention is used to cut a shingle to produce a shingle having a desired size and shape. The shingle cutter is portable and can be temporarily attached to and used on a roof. The power for cutting results from the housing of the cutting wheel being manually drawn back towards the operator.
The shingle cutter has a structural base attached to two end upright pieces that support a rectangular rack or bar, upon which a cutting wheel housing moves in a sliding manner. In one embodiment, the teeth of the bottom edge of the rack engage the gear teeth of a pinion, which in turn engage a circle of gear teeth fixed with and concentric with the cutting wheel. In another embodiment, the cutting block is supported by a rectangular guide bar with no teeth on its bottom edge. The cutting wheel is rotatably mounted on an axle disposed in a cutting block housing which is slidable along the bar. In both embodiments, the cutting block housing slides along the rectangular bar on four rollers whose axes are perpendicular to and are held rigidly by the two cutting block housing plates.
Accordingly, it is a principal object of the invention to provide a device for producing an efficient and clean cut edge on roof shingles in order to produce custom cut roof shingles.
It is another object of the invention to provide a convenient and easy to operate mechanism for cutting shingles.
It is a further object of the invention to provide a shingle cutting mechanism that is transportable from job site to job site and from ground level to roof top of the building where roof work is being performed. The shingle cutter of the present invention can be temporarily attached to the roof by a slotted mounting tab.
Still another object of the invention is to provide a device for cutting shingles to produce a variety of shapes for a variety of roofing conditions. Another object of the invention is to accommodate recent changes in the manufacture of shingles from a single layer to a multiple layer. This has made the cutting of shingles more difficult. This change has created a need for a more efficient and easier method of cutting shingles.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an environmental perspective view of a first embodiment of a shingle cutter according to the present invention.
FIG. 2 is a front perspective view of the first embodiment of the shingle cutter showing pivoting right and left fences being used to align a shingle for cutting a shingle at an angle.
FIG. 3A is a side elevation view of the first embodiment of the shingle cutter with part of the cutting block housing removed.
FIG. 3B is a detail view of the shingle cutter of FIG. 3A showing the pinion gear and cutting wheel and its driving gear adjusted so as to place the cutting wheel in a raised position.
FIG. 3C is a detail view of the shingle cutter of FIG. 3A showing the pinion gear and cutting wheel and its driving gear adjusted so as to place the cutting wheel in a lowered position.
FIG. 4 is a front perspective view of a second embodiment of the shingle cutter, featuring an alternative method using pegs for maintaining the shingle aligned in an angular position relative to the path of the cutting wheel.
FIG. 5 is a top view of the second embodiment of a shingle cutter according to the present invention.
FIG. 6 is a fragmented side perspective view of the second embodiment of the shingle cutter with part of the cutting block housing removed.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed to a roofing tool in the form of a shingle cutter. A first embodiment of the present invention is depicted in FIGS. 1-3 and is generally referenced by numeral 10 .
As generally illustrated in FIGS. 1-3, the shingle cutter 10 comprises a cutting block 26 that is mounted in a slidable manner on a rectangular rack 19 . The rectangular rack 19 is fixedly attached to a U-shaped frame which includes a structural base 14 and rear and forward walls 16 . The rectangular rack 19 is supported between the end walls 16 and spaced above a structural base 14 by a predetermined distance, the rack 19 being disposed in a plane normal to a plane in which the base 14 is disposed. The structural base 14 has a coplanar extension at a right angle to its length-wise dimension, hereinafter referred to as transverse base 17 . This transverse base 17 serves as a flat area for placing the shingle while it is being worked on. The forward edge of the transverse base 17 has two fences, 20 and 21 , that may be pivoted about pins 24 on the plane of the bases 17 and 14 and serve as a stop to prevent sliding of the shingle S during cutting. Although FIG. 1, for purposes of economy of illustration, depicts the operator cutting the shingle S in a direction moving away from the operator, the preferred method of operation is to position cutting block 26 at a point on rack 19 past the shingle S to be cut and then pull block 26 toward the operator I , thus cutting the shingle S. This is preferable in that fence 20 serves as a stop to avoid sliding of the shingle S.
The most externally conspicuous features of the cutting block 26 are the lower portions of the cutting wheel 31 , the right 27 and left 29 cutting block housing panels, and the right and left cutting block handles 28 . Aside from the handles, the most noticeable features on the panels 27 and 29 are the holes that accommodate the threaded ends of wheel axles, 52 , 66 , and 70 (shown in FIG. 3 ). A flat, elongated plate or shear ledge 32 is mounted on the structural base 14 such that one edge abuts the path of the cutting wheel 31 . The edge of the cutting wheel shear ledge 32 and the cutting wheel 31 coact in the same way each blade of a pair of scissors would cut or shear through a piece of material.
An elongated tab with a hole and slot 25 defined therein forms roof anchor 22 , which is used to anchor the shingle cutter to the roof by placing the hole portion of the hole and slot 25 of the tab 22 over the head of a nail attached to the roof and sliding the shaft of the nail into the slot. The roof anchor 22 is slidably mounted to the base 14 so that the anchor 22 can be retracted into a hollow space in the structural base 14 when the shingle cutter 10 is not in use. Two widened portions (not shown) on the end of the roof anchor 22 prevent the anchor from being pulled free of the shingle cutter 10 . The environmental perspective view of FIG. 1 shows an installer I cutting a shingle S by pulling the cutting block 26 by its handles, 28 . The shingle S is supported by the right 20 and left 21 pivotal fences as the cutting wheel 31 is drawn across the shingle S.
A second embodiment of the present invention is depicted in FIGS. 4-6 and is generally referenced by numeral 12 .
The second embodiment of the shingle cutter 12 , comprises the same or similar components as those of the shingle cutter 10 of the first embodiment. As shown in FIGS. 4-5, the shear ledge 132 may have a series of holes 62 into which shingle guiding pegs 63 are inserted. In the second embodiment, a fixed transverse back fence 61 is permanently fixed to the forward edge of the transverse base 17 . A cutter block bumper guard 23 projects from the forward end wall 16 in order to prevent the cutting block from bumping against the end wall 16 in both the first 10 and second 12 embodiments of the shingle cutter.
A side view of the cutting block 126 with the right panel 127 removed to show details of the cutting block 126 in FIG. 6 permits comparison of the first 10 and second 12 embodiments of the shingle cutter. Similar cutaway views are shown for the first embodiment in FIGS. 3A-3C. In both embodiments, the cutting block 26 or 126 is supported on the rack 19 or 119 by a plurality of roller wheels 45 which are rotatably mounted on axles 52 . Axles 52 are fixedly mounted to extend between plates 27 and 29 ( 127 and 129 in the second embodiment) and secured by axle nuts 37 . Each roller wheel 45 has a groove 56 or neck defined therein slightly greater than the thickness of the rack 19 or 119 so that the roller wheels 45 roll along the rack as the cutting block is pulled or pushed, the grooves 56 preventing lateral movement of the cutting block as it rolls along the rack. The roller wheels 45 may have a plurality of O-rings (not shown) disposed in the groove 56 to decrease rolling friction between the roller wheels 45 and the rack. The roller wheels 45 maintain the plates and in spaced apart relation.
AS shown in FIG. 3A, in a first embodiment the bottom edge of the rack has a plurality of gear teeth 51 defined therein which engage the gear teeth 65 of a pinion 64 which is rotatably mounted on axle 66 , which extends between plates 27 and 29 and is secured by nuts 35 (only one shown). Cutting wheel 31 is rotatably mounted on axle 70 , which is fixedly mounted between plates 27 and 29 and secured by nuts 33 (only one shown). The teeth of the pinion 64 engage the teeth of gear 71 , which is fixedly attached to cutting wheel 31 . Therefore, as the cutting block is pushed or pulled along rack 19 , pinion 64 drives gear 71 , causing cutting wheel 31 to rotate.
As shown in FIG. 6, in a second embodiment the bottom edge of rack 119 is smooth and has no gear teeth. The second embodiment includes roller wheels 45 as described above, but pinion 64 and gear 71 are absent. Cutting wheel 131 is rotatable mounted on axle 70 and rotates by frictional engagement of the edge of the cutting wheel 131 with the shingle S or other workpiece.
Referring to FIGS. 3B and 3C, in either the first or second embodiment, the height of the cutting wheel 31 or 131 may be made adjustable as follows. The axle 70 may include a cylindrical hub 72 mounted between the ends of the axle 70 . The cutting wheel may be rotatably mounted on the hub 72 . The hub 72 may be eccentrically mounted on the axle 70 . The end of the axle 70 may have a fitting 73 , such as an Allen head, so that the axle 70 may be rotated in its mounting holes. This raises and lowers the cutting wheel to adjust for different shingle thickness and depth of cut.
In the first embodiment, in order to compensate for movement of cutting gear wheel movement as cutting wheel 31 is raised upwardly or lowered downwardly to accomplish differing depth cuts, it may be necessary to mount pinion gear 64 in a manner similar to cutting wheel 31 in order to maintain proper mesh of its gear teeth with cutting wheel gear 71 while maintaining proper mesh with the gear teeth 51 along the lower edge of rectangular rack 19 . The axle 66 may include a cylindrical hub 67 mounted between the ends of the axle 66 . The pinion gear may be rotatably mounted on the hub. The hub may be eccentrically mounted on the axle 66 . The end of the axle 66 may have a fitting, such as an Allen head 68 , so that the axle 66 may be rotated in its mounting holes. This allows adjustment of the pinion gear 64 to maintain proper mesh with the cutting wheel gear 71 as the cutting wheel 31 is raised or lowered. Alternatively, the gear teeth of pinion 64 and cutting wheel gear 71 may be so designed so as to allow adequate meshing of the gears as cutting wheel 31 and its gear 71 as it is raised or lowered within a limited range so as to effectively turn cutting wheel 31 . In the second embodiment there are no gears or pinion so that the cutting wheel may be raised or lowered as described above without the need to manipulate gears for adequate meshing since the second embodiment employs no gears for operation.
As generally illustrated in FIG. 2, in a first embodiment, the shingle cutter 10 is shown cutting a shingle S using one or both pivotal fences 20 and 21 in order to make an angular cut. The right fence 20 rotates about the right pivotal fence pivot pin 24 to provide a reference position on the right end of the shingle S. The left fence 21 rotates about the left pivotal fence pivot pin (not shown) to provide a reference position on the forward long side of a shingle S. The positions of the rotated fences are associated with the particular angle at which the shingle S is being cut as long as the given sides of the shingle S are flush with their corresponding pivotal fences 20 and 21 .
As illustrated in FIG. 4, in a second embodiment, the shingle cutter 12 is shown cutting a shingle S using the pegs 63 and the peg holes 62 along a segment of the cutting wheel shear ledge 132 to orient the shingle S in order to make an angular cut. In FIG. 4, part of the apparatus is cut away to reveal the forward-most peg 63 located in forward-most peg hole 62 between both sections of the back fence 61 . The holes bored to hold the peg second closest to the operator are so placed that the direction of the width of the shingle S relative to the cutting direction corresponds to a pre-determined angle. The line between the two pegs, which is parallel to the cutting line, is the hypotenuse of a right triangle of which the width of the shingle S represents a side. The distance between the positions of the pegs 63 is determined by the inverse of trigonometric functions for pre-determined angles. Although a multiplicity of peg holes 62 are illustrated in FIGS. 4 and 6, the preferred number of peg holes 62 is four, corresponding to standard angle cuts in the industry. A standard spring-loaded clamp(not shown) may be attached where convenient such as near the intersection of the shingle S and transverse base 17 to assist in holding in place shingle S against transverse base 17 while the cutting operation is performed.
It is to be understood that the present invention is not limited to the sole embodiments described above, but encompasses any and all embodiments within the scope of the following claims. | A shingle cutter that is portable and can be temporarily attached to and used on the roof with the roofing nails used on the job. The power for cutting results from the housing of the cutting wheel being manually drawn back towards the operator. The shingle cutter has a structural base and two vertical end walls that support a rectangular rack, which holds the cutting block. In one version the rack drives a pinion, which in turn drives the cutting wheel. In a second version, the cutting wheel is free to rotate as it is pulled through the shingle. The cutting block is constrained by rollers in contact with the top and bottom of the rectangular guide bar so that the cutting wheel moves to perform a shearing function with an abutting shear ledge mounted on the structural base. | 8 |
FIELD OF THE INVENTION
The present invention relates to paper machine drying concepts and methods of air drying in the paper machine drying sections. More particularly, the present invention relates to the open draw sections of paper machine dryers where the paper web travels from top cylinders to bottom cylinders and then again from bottom cylinders to the upper cylinders, in an unsupported fashion. The invention could also be applied to a dryer section where the moist web is supported by a fabric or felt in a single tier or uni-run system.
BACKGROUND OF THE INVENTION
In a papermaking process, a moist paper web, after passing through mechanical water removal stations and a series of press nips, continues to pass over a series of heated cylinders that evaporates water form the web to approximately 95% dryness. The paper web, in a typical dryer section, is unsupported as it travels in a serpentine fashion between upper and lower dryer cylinder arrangements. A top and bottom fabric loop is arranged to guide the web around the cylinders. A top fabric or felt, guides the web around the group of top cylinders, which are situated in a single row at a high elevation, with felt turning rolls located between them and a lower fabric or felt run is similarly situated at the lower level. The web travels alternately between top and bottom cylinders. The top fabric or felt run disengages at the above location from the cylinders and the paper web, continuing to a fabric or felt turning roll, passing through a series of cylinders and felt rolls until the fabric is guided above the dryer section via turning rolls of a guide and stretcher arrangement in a closed loop fashion. A similar arrangement is fashioned for the bottom dryer section, creating an opposite fabric loop system for the lower dryer group.
The stretch or distance that the moist paper web has to travel from the upper dryer group to the bottom dryer group, unsupported by either cylinder or fabric, is called the open draw.
The conventional process through the industry is to include the supply air via different pocket ventilation systems using blow boxes of many and varied systems behind the fabric or felt turning rolls (i.e. above top felt turning rolls and below bottom felt turning rolls). The air from these blow boxes has to travel through the fabric in order to infiltrate the pocket of the open draw. This requires high open permeability of the fabric and, at high machine speed, much of the air is deflected, requiring a high air volume and high horsepower to force air through the fabric. Another standard method is to introduce air via the felt turning rolls, forcing air through the fabric into the pocket.
In either of the conventional cases, the air from the supply thereof is infiltrated into the pocket through the fabric itself and the ventilating felt roll systems as described above.
It is an accepted fact that if too much air is introduced into the pocket, the web bulges causing sheet breaks, especially where the sheet has a high moisture content and is consequently very weak. In addition, edge flutter may occur, especially at high machine speeds where the edge might stretch, causing a wrinkling effect in the web. Also, introducing an air jet directly perpendicular to the unsupported paper web can blow the sheet away from the jet, causing web breakage.
SUMMARY OF THE INVENTION
It is the primary object of the invention to address the problems of conventional practices as set out above by supplying air directly onto the paper web in the open draw section without having to move air through a fabric or any other paper or fabric support method in order to improve a mass movement of air onto the web. In accordance with the present invention, air is introduced via a cross-machine pocket ventilation system directly in the dryer pocket.
It is a further object of the invention to provide a method whereby the evaporation from the web is greatly enhanced by creating a high air turbulence on contact with the paper sheet surface. The high air turbulence created and directed onto the sheet results in a very effective scrubbing action at the vapor boundary layer of the sheet, increasing the mass transfer and consequently resulting in a high moisture evaporation rate. Furthermore, by impinging the relatively dry air directly onto the paper web (and avoiding dilution from surrounding relatively humid air which occurs in the conventional practises) the difference in partial pressure due to water vapour between the web and adjacent air is enhanced, thus increasing evaporative cooling in the draw, lowering the sheet temperature and allowing a greater heat transfer from the next steam heated dryer cylinder to the sheet, all resulting in a greater drying force.
It is a major object to accomplish the foregoing additional drying by utilizing a structure which is referred to as a radial jet reattachment nozzle. A standard air jet arrangement blowing perpendicularly to the sheet would blow the sheet away from the jet, causing paper web breakage. However, a unique feature of a radial jet reattachment nozzle is that it creates a negative force onto the web, thus pulling the sheet towards the nozzle, not away from the air impingement system as is common in conventional applications. The paper sheet will actually be pulled into a relatively straight linear web by the negative force of the radial jet reattachment blow box system towards the blow nozzles.
Furthermore, it is an object of the present invention to provide a method to control sheet flutter and sheet bulging without applying additional tension while travelling from an upper dryer cylinder to a lower dryer cylinder, (or vice-versa) the so-called open draw section.
It is still a further object to achieve cross-machine paper web moisture profile control by sectionalizing the multi-functional radial jet reattachment blow box across the width of a paper web.
In order to achieve the above objects, the invention makes use of a new concept for the industrial application of fluid mechanics in the drying of moist materials and centers around the design of a nozzle and reattachment configuration. This design permits the establishment of a radial jet reattachment on an adjacent surface. The radial jet reattachment nozzle produces a highly turbulent flow field which provides high surface transport co-efficients while permitting the magnitude and direction of the overall force of impingement to be controlled.
For the purpose of drying and sheet stabilizing, the invention provides a row of radial jet reattachment nozzles incorporated into a common supply header, introducing air directly onto the sheet in this unsupported paper draw section, whereby the magnitude and direction of the overall force of the impingement air can be controlled. This allows the placement of pocket ventilation air directly into a dryer pocket, adjacent and perpendicular to the paper web, to greatly increase the drying effect of the paper machine drying section, maintain or improve sheet stability, reduce the air humidity with a minimum of air volume and horsepower, and by controlling sections across the multi-functional radial jet reattachment nozzle blow box, control the cross-machine moisture profile of the web as well.
The principal characteristic feature of the invention is that the device comprises a blow box or boxes, complete with one or several arrays of the above described nozzles for the full width of the nozzle box, and then arranged to function against the paper web essentially throughout the width thereof; and whereby the impingement effect of the radial jet reattachment nozzle of the nozzle box is arranged to reach the web while the web is unsupported by either cylinder, fabric or felt.
The operation of the device is based on careful selection of the angle at which air exits the radial jet reattachment nozzles, plus the control of the air flow to the nozzles. These variables determine the pattern of the flow of the air which is responsible for the force which acts on the web. Thus, this controls the overall force of the impingement air onto the web in magnitude and direction by creating areas of underpressure below and between the nozzles via turbulent eddy currents. This control of air force towards the paper web allows the actual pulling of the web towards the radial jet reattachment nozzle box, preventing the normal bulging and sheet flutter that might otherwise occur. Straightening the paper sheet prevents undue web stress, minimizes sheet breaks, machine downtime and sheet wrinkling. While not essential to every application of the invention, the blow box may, if desired, incorporate an additional slot on the edge of the nozzle box to employ the Coanda Effect allowing the air flow to follow the contour of the blow box, evacuating the air before the air enters the area of the dryer and converging paper web after the web has travelled past the multi-functional radial jet reattachment nozzle blow box. By removing the air gently via the Coanda effect, a pressurizing of this area is greatly minimized.
In a device in accordance with the invention, the radial jet reattachment blow box extends over the whole width of the web, but the device may be compartmentalized, or the nozzles may be controlled directly to achieve different evaporation loads across the width of the web to control moisture profiling, thereby improving sheet quality.
DESCRIPTION OF THE DRAWINGS
The invention is illustrated, by way of example, in the accompanying drawings in which:
FIG. 1 is a schematic side elevation view of a typical dryer section using the prior art standard pocket ventilation system;
FIG. 2 is a schematic side elevation view of a typical dryer section using a multi-functional blow box system in accordance with this invention;
FIG. 3 is an end elevation of a multi-functional blow box and the radial jet reattachment nozzle as used according to this invention;
FIG. 4 is a fragmentary side view of a dryer pocket showing the location of the blow box in operating position, and the broken line indicating the blow box retracted position, shown in FIG. 2;
FIG. 5 is a front elevational view of the multi-functional radial jet reattachment blow box;
FIGS. 6a and 6b are schematic cross-section and plan views respectively illustrating the relationship between the forces of nozzle air and the paper sheet;
FIG. 7 is a fragmentary view of a nozzle body showing one example for adjusting the nozzle flow;
FIG. 8 is a cross-sectional view of the nozzle body showing another example for adjusting nozzle flow; and
FIG. 9 is a cross-sectional view of one form of nozzle structure.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a portion of a typical paper machine dryer section including an upper row of drying cylinders 2, 4, 6 and 8 and a bottom row of drying cylinders 1, 3, 5 and 7. As shown a paper web P1 travels from a bottom dryer i to a top dryer 2 and then again from the top dryer 2 to the next bottom dryer 3 and so on in a serpentine fashion. The top and bottom fabric 10, 12 respectively only guides with a certain pressure on the paper cylinder surface. FIG. 1 further illustrates a standard pocket ventilation nozzle 14 supplying air from behind (above or below depending on top or bottom roll) felt turning rolls 16. In this arrangement the air is forced via an air jet arrangement through the fabric to provide air into the dryer pocket 18. On high speed machines, a great amount of air is deflected via the fabric 10, 12 and therefore not effectively introduced into the dryer pocket. Furthermore air which does enter the dryer pocket 18 might cause paper sheet bulging (P) or may create cross-machine air flow causing sheet flutter and wrinkle and sheet breaks can be the result of the foregoing.
FIG. 2 illustrates the location of a multi-functional radial jet reattachment blow box 20 according to the invention and located inside the dryer pocket 18 adjacent and perpendicular to the paper web P1. In general, the present invention overcomes the air bulging and sheet flutter problem discussed with respect to the prior art in Figure i by providing a negative force onto the web P1, thus pulling the paper sheet towards the nozzle as a result of the functioning of the radial jet reattachment nozzle 20, subsequently to be described in detail.
The number of blow boxes, nozzles required air flow and the like are specific to each machine. Therefore, for the purpose of example only, FIG. 2 illustrates a total of six nozzle arrangements, 20, 22, 24, 26, 28 and 30, all located either above or below the dryer cylinders outside the fabric loops 32, 34, relocated from the narrow space between the dryer cylinders. The blow box nozzles 20-30 are positioned in a staggered arrangement for uniform drying, as shown by the phantom nozzles 90 in FIG. 5. In general, a paper machine would have many similar dryer sections, as illustrated in FIGS. 1 and 2. Each section would receive in a similar fashion multi-functional nozzles in each dryer pocket 18. While not forming part of this invention, FIG. 2 further illustrates a typical hot air supply unit 36 complete with the necessary ductwork 38, 40 supplying air to all six nozzles 20-30 inclusive.
FIG. 3 illustrates some of the details of the multi-functional radial jet reattachment nozzle box 42 in accordance with this invention. As illustrated therein, the blow box 42 is a hollow shell particularly shaped to be parallel to the web P1, allowing an array of radial jet reattachment nozzles 30 to be mounted at the face plate 44 and having a plenum body feeding each nozzle such as 30 with an amount of air. The nozzle face plate 44 has further a perforated nozzle protection shield 50 to avoid paper hang-up. A cylinder mounting plate 52 is secured to the plenum 42 which makes it possible to achieve a certain pivot movement via a cylinder stroke.
In addition, slot 54 has been added to the plenum to allow air gently to be moved away form the web via the Coanda effect.
FIG. 4 illustrates nozzle 30 and the associated blow box 42 location above dryer No. 7 and dryer cylinder No. 6 (FIG. 2) at the left side of the box 42. The paper is conveyed from the upper dryer cylinder No. 6 to the lower dryer cylinder No. 7. In the meantime, the fabric 10 has separated from dryer cylinder No. 6 and moves toward the fabric turning roll 16. Thus the paper web P1 is now unsupported between dryer cylinder No. 6 and No. 7, creating the open paper draw.
FIG. 4 further shows the radial jet reattachment nozzle 30 positioned perpendicular to the web and the blow box 42 with a plenum face 44. A pivot point 46 is shown, allowing the radial jet reattachment blow box 42 to pivot away from the paper sheet P1 during threading. Further, a front mounting bracket 48 is shown allowing the blow box 42 to be adjusted fore and aft.
FIG. 5 illustrates an array of radial jet reattachment nozzles 30 that extend across the paper sheet width to achieve uniform drying across the paper web. The blow box 42 is provided with two pivot supports 46 and the nozzle protection shield 50 over the full width of the nozzle. Air can be supplied from either end of the blow box 42, and similarly, the cylinder to pivot the blow box can be mounted either side.
Various forces act on a paper sheet as the paper travels from one dryer to the next. At the central area of the paper draw between top and bottom dryers, the present invention is utilized to apply a maximum negative force to pull the paper sheet towards the nozzles 30 and to flatten or straighten the paper sheet. The desire to apply the maximum negative force to the paper web at that position dictates the location of the blow boxes and their associated nozzles. The various forces that act on the sheet are for example an adhesion force, a vacuum force, a suction force, a pressure force as well as a centrifugal force from the weight of the paper.
In the arrangement according to the invention, an air cushion is provided between the head of the nozzles 30 and the paper sheet, this air cushion preventing the sheet from touching the nozzle heads so there is no contact between the metal and the sheet. At the same time, the sheet is forced toward the nozzles via regulation of the air flow from nozzles. FIGS. 6a and 6b show the path of the air from the nozzle body 30, through the area between the nozzle heads 60 and the bodies of the nozzle, the air flow providing (a) a cushion between the nozzle heads 60 and the sheet itself and also illustrates the air leaving the nozzles in a negative angle which creates a turbulence as at 62 on the sheet with an air flow away from the sheet both immediately underneath the nozzle heads and also between adjacent nozzles 30 and which creates a negative force that pulls the sheet towards the nozzles.
It may also be desirable to sectionalize the air flow for moisture profiling of the sheet. This could be accomplished by an external adjustment to the nozzles 30, one example being shown in FIG. 7 where a peripheral ring 64 is mounted on the outer surface of the nozzle body for slidable movement therealong whereby the ring can be moved to open or close the peripheral area between the nozzle head 60 and the adjacent rim of the nozzle body so as to regulate the amount of air emanating therefrom. A selective use of the rings 64 on a plurality of nozzles on the blow box, could be utilized to apply a desired amount of drying and air forces to specific areas of the web.
Figure S illustrates a further example of adjusting the amount of air emanating from the nozzle. Nozzle body 30 has a nozzle head 74 and its associated stem 76 slidably mounted for axial movement in the body 30. This is accomplished by a pair of spaced mounting brackets 78 having central collars 80 in which the stem 76 is slidably positioned.
An aperture 82 in the cylindrical wall of the nozzle body accommodates an adjusting rod 84 which may interconnect one or more stems 76 and which can be manually or automatically actuated to move the stem 76 and head 74 inwardly or outwardly to open or close the space between the peripheral edge of the nozzle body and the adjacent surface of the head 74.
The sliding rings 64 and the axially moveable nozzle stems and heads are but two examples of means for adjusting the air flow and these could be actuated either manually or automatically, for example, responsive to web moisture.
FIG. 9 shows one example of a nozzle structure in which the tubular or cylindrical nozzle body 30 has the nozzle head 60 located in the body 30 by means of an elongated stem 66 securely positioned in the body by means of one or more mounting brackets 68 each of which comprise a central sleeve 72 coaxially located on the outer surface of the stem 66 and a plurality of radially extending legs 70 engaging the inner surface of the valve 30.
While the invention has been described in connection with a specific embodiment thereof and in a specific use, various modifications thereof will occur to those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.
The terms and expressions which have been employed in this specification are used as terms of description and not of limitations, and there is no intention in the use of such terms and expressions to exclude any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claims. | An improved air drying process for a paper machine is disclosed whereby air is impinged directly onto a paper web between top and bottom dryers on an open paper draw. This provides additional drying and machine speed increase due to improved controlling of sheet flutter and improved drying via direct air impingement onto the sheet for all paper grades. The structure provides a radial jet reattachment nozzle to blow air onto the sheet while the paper web is not in contact with either cylinder surface and the fabric or felt. The nozzle stabilizes and supports the sheet to prevent sheet flutter and bulging. | 3 |
TECHNICAL FIELD
The present application relates to fault diagnosis and mitigation in motor vehicles, and more particularly to fueling error diagnosis and mitigation.
BACKGROUND
Motor-vehicle fuels of different compositions are sold alongside each other at filling stations. In particular, fuel mixtures comprising ethanol and gasoline are increasingly available, some of which may be used in conventional gasoline engines, while others may be used only in specially configured engines. E85, for instance, is a suitable fuel for so called flex-fuel vehicles: vehicles configured to run on widely varying fuel mixtures. Other mixtures, E10, for example, can be used in conventional gasoline engines so long as an appropriately homogenized mixture is provided.
However, some fuel distributors rely on splash blending during fuel transport to homogenize fuel mixtures. This method does not guarantee homogeneity and may result in a stratified mixture being supplied to the filling station. Thus, the mixture supplied to a customer's fuel tank may differ substantially from the expected composition. Moreover, stratification of a well-homogenized fuel mixture may occur on long standing in a vehicle's fuel tank as a result of repeated evaporation and condensation of fuel components. These factors may result in an inappropriately alcohol-rich fuel mixture being supplied to a gasoline engine not specially configured and/or controlled for alcohol-rich mixtures.
Further, vehicle fuel tank misfueling may be caused by simple, human error: a motorist or filling-station attendant may erroneously pump E85, for example, into a non-flex fuel vehicle. Results of misfueling may include degraded operation, e.g., stalling, difficulty starting, and rough idle. Further still, the misfueled motor vehicle may issue malfunction codes (MIL codes) that misdiagnose the problem. Misdiagnosis could trigger the servicing or replacement of non-defective, expensive parts, such as catalysts, fuel injectors, fuel pumps, exhaust gas oxygen sensors, or others. In addition, damage may occur to fuel-system or engine parts that are not resistant to high alcohol concentrations.
Finally, as alcohol-based fuels and alcohol-fueled vehicles become ever more common, the converse problem may arise: a vehicle designed to run on high-alcohol content fuel may be fueled erroneously with gasoline.
The inventors herein have recognized the above problems and have devised various solutions. For example, a method is provided to indicate improper fuel filling in a vehicle. In this method, an indicator is actuated if a proportion of alcohol in the fuel is outside a range of expected proportions. In some examples, the range corresponds to a non-flex fuel vehicle recommended range, or to an expected range for a low alcohol-content fuel, which may be between 0 and 15 percent alcohol by volume. The indicator may include a diagnostic code or a dash light. Further, the indicator may be actuated in combination with a mitigating action, which may involve adjustment of a fuel injector pulse width or an ignition spark timing, as examples.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an example configuration of vehicle components in accordance with the present disclosure.
FIG. 2 illustrates, by way of a flow chart, an example algorithm for fueling error diagnosis and mitigation in accordance with the present disclosure.
FIG. 3 shows a schematic diagram of an owner's manual of a vehicle with an example fixed fueling indicator.
FIG. 4 shows a schematic diagram of a fuel door of a vehicle with an example fixed fueling indicator.
DETAILED DESCRIPTION
FIG. 1 shows an example configuration of vehicle components in accordance with the present disclosure. FIG. 1 shows cylinder 102 with intake valve 104 , spark-ignition device 106 , fuel injector 108 , exhaust valve 110 , and crank-angle sensor 112 . Cylinder 102 may be one of several cylinders in an engine of a vehicle. In this example, at least some fuel enters cylinder 102 through fuel injector 108 . Air enters cylinder 102 through intake valve 104 . In some embodiments, fuel may enter the cylinder through the intake valve as well as the fuel injector. Thus, the configuration of components shown in FIG. 1 is intended to enable direct injection and arbitrary combinations of direct and port injection.
FIG. 1 also shows air-fuel ratio sensor 114 , fuel tank 116 , refill sensor 118 , fuel composition sensor 120 , and controller 122 . Refill sensor 118 is a device installed in the vehicle and configured to generate an output signal that indicates when fuel has been added to a fuel tank of the vehicle. Fuel composition sensor 120 is a device installed in the fuel system of the vehicle and configured to generate an output signal that is a function of the alcohol content of the fuel, i.e., the proportion or relative amount of alcohol in the fuel. Note that the proportion of alcohol in a fuel may be expressed as a volume percent or as a weight percent, which are interconvertible if the composition or distribution of the alcohols in the fuel is known. Alcohols that may be included in motor-vehicle fuel blends include methanol, ethanol, isopropyl alcohol, and others. In this example, refill sensor 118 and fuel composition sensor 120 are enclosed within fuel tank 116 , but in other embodiments, they may be located elsewhere within the fuel system. In particular, fuel composition sensor 120 may be located within or in proximity to a conduit that conducts fuel from fuel tank 116 to a fuel pump of the vehicle. In this way, the fuel composition sensor may be configured to reflect specifically an alcohol content of the fuel entering the fuel pump (in the event that alcohol is distributed inhomogeneously within the fuel system).
Controller 122 is configured to accept input signals from crank-angle sensor 112 , air-fuel ratio sensor 114 , refill sensor 118 , and fuel composition sensor 120 . Controller 122 is further configured to provide control signals to spark-ignition device 106 and fuel injector 108 . FIG. 1 also shows high-alcohol indicator 124 and low-alcohol indicator 126 , to which controller 122 is further configured to provide control signals. High-alcohol indicator 124 and low-alcohol indicator 126 are configured to receive control signals from controller 122 and to alert an operator of the vehicle when the alcohol content of the fuel is outside an expected range. In some embodiments, one or more of the indicators may be visual, e.g., an illuminated signal on a dashboard of the vehicle. In some embodiments, one or both of the indicators may be audible. In still other embodiments, one or both of the indicators may include setting a diagnostic code in an on-board diagnostic system of the vehicle. The code may indicate the manner of vehicle misfueling, e.g. alcohol content too high or too low, and may be readable by a universal diagnostic code reader of a kind known in the art.
Finally, FIG. 1 shows fixed fueling indicator 128 , which indicates a range of expected proportions of alcohol in the vehicle fuel. In this example, fixed fueling indicator 128 is a label located on or close to fuel filling cap 130 that indicates the range implicitly in words. Other such examples might include “UNLEADED GASOLINE ONLY” or “GASOLINE/E10 ONLY,” to indicate that the expected range is 0 to 10 percent ethanol by volume. In still other examples, the range of expected proportions of alcohol may be stated more explicitly, “ALCOHOL 15% MAXIMUM,” for example. Any of these examples may be included as an indicator that the vehicle is a non-flex fuel vehicle. In other embodiments, fixed fueling indicator 128 may be separate from the vehicle but included as text in an owner's manual of the vehicle. The information conveyed by fixed fueling indicator 128 may in some embodiments be consistent with the language used to market the vehicle for sale. Thus, a vehicle comprising the components shown in FIG. 1 and the fixed fueling indicator included therein may be marketed as a “gasoline-only” vehicle or a “non-flex fuel” vehicle.
It should be understood that FIG. 1 is entirely schematic. The components included therein may comprise significant structure not shown in the figure. The structure that is shown may be rendered in a simplified form. For example, spark-ignition device 106 may comprise not only a spark plug, as the drawing suggests, but also a distributorless spark-ignition system that provides voltage to the spark plug. Likewise, controller 122 may comprise a plurality of interconnected electronic devices distributed throughout the vehicle. It should further be understood that FIG. 1 is intended to be non-limiting. For instance, the vehicle engine may comprise additional cylinders with additional fuel injectors and additional sensors. Controller 122 may be configured to accept input signals from the additional sensors as well, and to provide control signals to the additional fuel injectors.
FIG. 2 illustrates, by way of a flow chart, an example algorithm by which controller 122 may execute fueling diagnosis and mitigation in accordance with the present disclosure. In describing the algorithm, continued numerical reference is made to the components of FIG. 1 . At 202 , controller 122 determines if a refill of fuel tank 116 has occurred. In making this determination, controller 122 may rely on an input signal from refill sensor 118 . At 204 , controller 122 determines if a fuel composition sensor, e.g. fuel composition sensor 120 , is installed in the fuel system of the vehicle. If a fuel composition sensor is installed, then at 206 , controller 122 reads an output from the fuel composition sensor to determine the content of alcohol in the fuel.
If no fuel composition sensor is installed, then at 208 , controller 122 executes an alcohol-determining algorithm to determine the content of alcohol in the fuel. In one example, the alcohol-determining algorithm may include controller 122 metering an amount of fuel through fuel injector 108 and an amount of air through intake valve 104 , and receiving an input from air-fuel ratio sensor 114 . These steps may be performed iteratively, with one or more of the metered amounts adjusted at each iteration to maintain the air-fuel ratio sensor at stoichiometry. As is known in the art, the metered amounts may be used by controller 122 to calculate an oxygen content in the fuel, which may be used to estimate the alcohol content of fuel mixtures composed substantially of hydrocarbons and alcohol.
Whether determined by reading a sensor or by executing an alcohol-determining algorithm as described above, the alcohol content of the fuel is compared, at 210 , to threshold values A H and A L , with A H >A L . If the alcohol content of the fuel is between A H and A L , it is indicated to be within the expected range for the vehicle. If the alcohol content of the fuel is above A H , then at 212 , controller 122 activates high-alcohol indicator 124 . If the alcohol content of the fuel is below A L , then at 214 , controller 122 activates low-alcohol indicator 126 . Note that the conditions A H =0, A L =0, A H =100% by volume, and A L =100% by volume are each allowed in some embodiments.
The example algorithm illustrated in FIG. 2 further comprises adjusting one or more engine operating parameters with actuation of high-alcohol indicator 124 or low-alcohol indicator 126 . In this way, controller 122 may be configured to take mitigating action when a proportion of alcohol in the fuel system is unexpectedly high or low. At 216 , controller 122 adjusts a pulse width of a fuel-delivery pulse of fuel injector 108 based on the alcohol content of the fuel. The pulse width may be adjusted if the alcohol content of the fuel is above A H and/or below A L . In some examples, controller 122 may be configured to increase the injector pulse width with increasing alcohol content of the fuel and to decrease the injector pulse width with decreasing alcohol content of the fuel.
At 218 , controller 122 adjusts a timing of spark-ignition device 106 based on the alcohol content of the fuel. The timing may be adjusted if the alcohol content of the fuel is above A H and/or below A L . In some examples, controller 122 may be configured to advance the spark from spark-ignition device 106 with increasing alcohol content of the fuel and to retard the spark from spark-ignition device 106 with decreasing alcohol content of the fuel.
At 219 , controller 122 takes further mitigating action by adjusting other vehicle parameters based on the alcohol content of the fuel. The further mitigating action may be taken if the alcohol content of the fuel is above A H and/or below A L . Examples of further mitigating action may include modifying how throttle position varies with torque request as a function of alcohol content, or changing a compression ratio of a turbocharger as a function of alcohol content. Such adjustments may be advantageous due to the lower power density of alcohol fuels relative to gasoline.
In this example, adjusting injector pulse width at 216 , adjusting spark timing at 218 , and adjusting other parameters at 219 are executed only when the alcohol content of the fuel is above A H or below A L . In other embodiments, steps 216 to 219 may be executed as functions of the alcohol content of the fuel irrespective of whether said content is outside an expected range for the vehicle.
Continuing in FIG. 2 , at 220 , controller 122 compares the alcohol content of the fuel to threshold values A HH and A LL , with A HH ≧A H , A LL ≦A L , and A HH >A LL . In one example, these values may bracket an alcohol-content interval outside of which the vehicle may not be able to operate acceptably. In other examples, they may bracket an interval outside of which serious damage to the vehicle may occur. If the alcohol content of the fuel is above A HH or below A LL , then at 222 , controller 122 indicates to the operator of the vehicle that the alcohol content of the fuel is outside of a remediable operating range. In one example, the indication may include enhancing an output of high-alcohol indicator 124 or low-alcohol indicator 126 , such as by causing a panel lamp to blink, an audible indicator to sound more loudly, etc.
Finally, at 224 , controller 122 resets refill sensor 118 so that evaluation of the alcohol content in the fuel may be suspended until the next refill. Thus, in this example, the alcohol content of the fuel is evaluated, indicator status is updated, and mitigating actions are taken only once with each refill event. Other embodiments are contemplated, however, in which steps 204 through 222 are executed repeatedly throughout the fueling cycle.
FIGS. 3 and 4 are included to illustrate example dispositions of fixed fueling indicators in accordance with the present disclosure. Thus, FIG. 3 shows a schematic diagram of owner's manual 300 of a vehicle with fixed fueling indicator 128 as text in the owner's manual. FIG. 4 shows a schematic diagram of fuel door 400 of a vehicle with fixed fueling indicator 128 as a label juxtaposed to fuel filling cap 130 .
It should be understood that the systems and methods described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are contemplated. Accordingly, the present disclosure includes all novel and non-obvious combinations of the various systems and methods disclosed herein, as well as any and all equivalents thereof. | A method is provided to indicate improper fuel filling in a vehicle. An indicator is actuated if a proportion of alcohol in the fuel is outside a range of expected proportions. In some examples, the range corresponds to a non-flex fuel vehicle recommended range, or to a normal range for a low alcohol-content fuel, which may be between 0 and 15 percent alcohol by volume. The indicator may include a diagnostic code or a dash light. Further, the indicator may be actuated in combination with a mitigating action, which may involve adjustment of a fuel injector pulse width or an ignition spark timing, as examples. | 5 |
This is a Continuation application of application Ser. No. 07/994,339, filed Dec. 21, 1992, now U.S. Pat. No. 5,382,836.
BACKGROUND OF THE INVENTION
The present invention relates to a push-button switch device and in particular, to a push-button switch device suitable far equipment incorporating a large number of push-button switches such as pendant switches.
FIG. 19 depicts the electric circuit of a 2-step type push-button switch for controlling an inverter used generally for a pendant switch. The push-button switch device 100 consists of a switch unit 101 and an output unit connected to an AC source at respective R and S terminals. The switch unit 101 is provided with two push-button switches PBa, PBb. The push-button switch PBa is provided with a 1st-stage switch 103 and a 2nd-stage switch 104 while the push-button switch PBb has a 1st-stage switch 105 and a 2nd-stage switch 106. FIG. 19 shows an example in which the 2nd-stage switches of the both push-button switches transmit a same signal and are connected to one same transmitting line a1.
With this arrangement, the 3 kinds of signals transmitted by the switch unit 101 are connected with the output unit 102 by transmitting lines a1, a2, a3, respectively, and the output unit 102 works with the signals from the switch unit 107 through detecting members 107, 108, 109 each formed by a by photocoupler, for example, provided for the respective transmitting lines, so as to transmit operating signals. Namely, the 3 transmitting lines a1, a2, a3 are required to transmit 3 different kinds of signals. For that reason, equipment incorporating a large number of push-button devices in one operating unit such as a pendant switch for operating a crane, hoist, etc., for example, requires wires of a number at least 3 times larger than the number of push-button switch devices plus one common line.
In that case, there is no problem if the number of push-button switch devices incorporated in the pendant switch, etc. is small. In recent times, however, inverter control is being increasingly used in place of the electromagnetic contactor and the specifications of pendant switch are becoming more an more complicated with incorporation of a buzzer switch or switching between linked operation and single operation, etc. Therefore, there is a general tendency for multi-point construction of the pendant switch and multi-stage construction of individual switches. This leads to an increase in the number of cable wires, an increase in the outer dimensions of the pendant switch and an increase in the weight of the cable itself. As a result, the wire bundle becomes rigid and makes the operation of pendant switch difficult in some cases.
SUMMARY OF THE INVENTION
The object of the present invention is to reduce the size of the switch unit and reduce the number of wires by adopting a double transmission system in which a plural number of signals are transmitted through one cable to simplify the circuit.
To achieve the above object, the present invention is composed-of a switch unit having a pair of push-button switches and diodes and an output circuit for detecting an electric current sent from the switch unit, in which selective closing of the push-button switches in the switch unit results in transmitting a plural number of signals, those plural number of signals being transmitted to the output unit through a common transmitting line, and in which the output unit is provided with discriminating means for discriminating such signals and transmitting prescribed operating signals according to the signal current.
With such arrangement, the push-button switch device of the present invention can reduce the number of the signal lines conducted between the switch unit and the output unit. Therefore, if the switch unit is incorporated in a pendant switch, for example, it is possible to reduce the weight of the conductors themselves and increase the operability and the reliability of the pendant switch at the same time. Moreover, it becomes possible to use the same cable as the signal line of an AC commercial voltage circuit without using any special shielded wire, etc. as the signal line.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general circuit diagram of the first example of the push-button switch device of the present invention.
FIG. 2 is an explanatory chart of a signal current of the first example.
FIG. 3 is a general circuit diagram of the second example of the push-button switch device of the present invention.
FIG. 4 is an explanatory chart of a signal current of the second example.
FIG. 5 is an explanatory chart of a signal current waveform.
FIG. 6 is a circuit diagram of the output unit of the second example.
FIG. 7 is a general circuit diagram of the third example of the push-button switch device of the present invention.
FIG. 8 is an explanatory chart of a signal current of the third example.
FIG. 9 is a circuit diagram of the output unit of the third example.
FIG. 10 is a general circuit diagram of the fourth example of the push-button switch device of the present invention.
FIG. 11 is an explanatory chart of a signal current of the fourth example.
FIG. 12 is a circuit diagram of the output unit of the fourth example.
FIG. 13 is a general circuit diagram of the fifth example of the push-button switch device of the present invention.
FIG. 14 is an explanatory chart of a signal current of the fifth example.
FIG. 15 is a perspective view of the push-button switch of the fifth example.
FIG. 16 is a general circuit diagram of the sixth example of the push-button switch device of the present invention.
FIG. 17 is an explanatory chart of a signal current of the sixth example.
FIG. 18 is a circuit diagram of the output unit of the sixth example.
FIG. 19 is a circuit diagram of switch signals for inverter control using a conventional 2-stage push-button switch device.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be explained hereafter based on illustrated examples. It is noted that like parts are designated by like reference numeral and letters throughout the accompanying drawings.
FIG. 1 and FIG. 2 indicate the first example. This push-button switch device 1 consists of a switch unit 2 and an output unit 3. The switch unit 2 is composed of a pair of push-button switches PB1, PB2 and diodes D1, D2 (hereinafter simply referred to as PB for push-button switches and D for diodes when they are called by a general name in the respective examples). The push-button switch PB1 and the diode D1 are connected in series, with the diode D1 in a forward direction, while the push-button switch PB2 and the diode D2 are connected in series with the diode D2 in a reverse direction, and these two circuits are connected in parallel. The two circuits are connected to the output unit 3 through a common transmitting line S1.
The output unit 3 is provided with discriminating means PC1, PC2 (hereinafter simply referred to as PC when they are called by a general name). FIG. 1 shows an example of using photocouplers as such discriminating means and a phototransistor for output, but it is also possible to use a cds cell, MOS relay, etc. instead. One discriminating means PC1 works with a normal half-wave rectification signal i.e. closing of push-button switch PB1 and the other discriminating means PC2 works with a half-wave rectification signal in a reverse direction i.e. closing of push-button switch PB2, to apply operating signals to an interface IF, for example, of the next process.
FIG. 2 indicates the current flowing through the transmitting line S1 with the closing of the respective push-button switches and the output of the discriminating means in the output unit. Namely, upon closing of the push-button switch PB1, only a pulsating current of positive half-wave rectification, is output and upon closing of the other push-button switch PB2 only a pulsating current of negative half-wave rectification is output, and upon simultaneous closing of both push-button switches, a full-wave alternating current is output. The respective discriminating means PC1, PC2 of the output unit 3 transmit output signals in response to such outputs as mentioned earlier. However, both discriminating means PC1, PC2 transmit output signals simultaneously in response to an alternating current. Namely, the switch circuit is arranged in such a way that the 4 signals produced with the closing of the respective push-button switches PB1, PB2 are transmitted to the output line 3 through one transmitting line S1.
Next, FIG. 3 to FIG. 6 indicate the second example. The push-button switch device of this example shows a switch unit using a 2-stage type push-button switch in which the switch unit 11 of the push-button switch device 10 consists of a first push-button switch PB3, a second push-button switch PB4 and a diode D1. The first-stage switch 13 of the first push-button switch PB3 and the first-stage switch 15 of the second push-button switch PB4 are provided in series to the common diode D1 and closing of the other second-stage switches 14, 16 outputs an alternating signal respectively.
The first-stage switch 13 and the second-stage switch 14 of said first push-button switch PB3 and the first-stage switch 15 and the second-stage switch 15 of the second push-button switch PB4 are connected respectively to a common transmitting line S3.
Reference IL in the drawings indicates an interlock provided to prevent simultaneous closing of the two push-button switches.
FIG. 4 shows outputs produced upon closing of the push-button switches. In the drawing, the columns 1, 2 of the push-button switches PB3, PB4 indicate the ON state of the first-stage switch and the second-stage switch respectively. The output waveform of those switches appears as shown in FIG. 5, W0 indicating 0 output, W1 the pulsation of positive half-wave rectification and W2 the alternating current of full wave, while W3 indicates the pulsation of negative half-wave rectification.
FIG. 6 indicates the output unit 12. This output unit 2 is constituted as an interface circuit and is provided with detectors PC3, PC4 forming a pair with the output line S2 and being in opposite phase, and discriminating means PC5, PC6 forming a pair with the output line S3 and being in opposite phase. With such an arrangement, the output unit 12 discriminates positive or negative of the signal current sent through the respective transmitting lines S2, S3 and selects those signals to apply a signal current to comparators CR1, CR2, CR3, CR4 through an integrating circuit of a resistor and capacitor to a control inverter as operating current signals U, D, etc. (illustration omitted).
Namely, in this example the two signals or the positive half-wave rectification signal and the alternating signal sent from the push-button switch PB3 of the switch unit are transmitted to the output line 12 through one transmitting line S2 and the positive half-wave rectification signal and the alternating signal sent from the push-button switch PB4 are transmitted to the output line 12 through one transmitting line S3.
Next, FIG. 7 to FIG. 9 indicate the third example. The switch unit 21 of the push-button switch device 20 of this example is also provided with diodes D1, D2 forming pairs with 2-stage push-button switches PB3, PB4 in the same way as the preceding example. The diode D1 is provided in a forward direction in the first-stage switch 13 of the push-button switch and the diode D2 is provided in a reverse direction in the first-stage switch 15 of the push-button switch PB4 in series respectively. The two switches PB3, PB4 are connected to the first transmitting line S4. The second-stage switches 14, 16 are connected to the second transmitting line S5.
FIG. 8 indicates outputs produced upon closing of push-button switches of this example. The output waveform of those switches appears as shown in FIG. 5, W0 indicating 0 output, W1 the output current of the pulsation of positive half-wave rectification and W2 that of the alternating current of full wave, while W3 indicates the output current of the pulsation of negative half-wave rectification.
FIG. 9 indicates the output unit 22 of this example. This output unit 22 is also constituted as an interface circuit as in the previous example. Only an alternating current signal is applied to the transmitting line S5 and it is discriminated by the discriminating means PC7. To the other transmitting line S4, signal currents of positive and negative half-wave rectifications are applied and discriminated by 2 discriminating means PC8, PC9. Those signals are selected and applied to the comparators CR5, CR6 through an integrating circuit of resistors and capacitors to generate operating current signals U,D. Namely, the two signals are transmitted to the transmitting line S4 and are discriminated by the output unit.
Next, FIG. 10 and FIG. 12 indicate the fourth example of the push-button device. The switch unit 31 of the push-button switch device 30 of this example is provided with a pair of 3-stage push-button switches PB5, PB6 and 3 diodes D1, D2, D3. The respective first contacts 33, 36 of the push-button switches PB5, PB6 are accompanied by normally closed contacts 33b, 36b. The said diode D1 is connected to the first contact 33 of the first push-button switch PB5 in series in a forward direction and the diode D2 is connected to the first contact 36 of the first push-button switch PB6 in a series in reverse direction, and both first contacts 33, 36 are connected to the output unit 32 through a common first transmitting line S6. Moreover, the diode D3 is connected to the second control 37 of the second push-button switch PB6 in series in a forward direction, and the second conduits 34, 37 and third contacts 35, 38 of the respective push-button switches are connected to the output unit 32 through a common second transmitting line S7.
FIG. 11 indicates the outputs produced upon closing of the push-button switches of this example. According to this example, 2 different kinds of signals can be transmitted to each of the two transmitting lines S6, S7 or 4 different kinds of signals in total can be transmitted. FIG. 12 indicates an example of output unit according to this example. This output unit 32 is also realized as an interface circuit as in the previous example. Pulsating signal currents of positive and negative half-wave rectification are applied to the transmitting line S6 and discriminated by a pair of discriminating means PC10, PC11. To the other transmitting line S7, a pulsating signal current of positive half-wave rectification and an alternating signal current are applied and discriminated by 2 discriminating means PC12, PC13. These signals are selected and applied to the comparators CR7, CR9 and CR10 through an integrating circuit of resistors and capacitors. Namely, each of the two transmitting lines S6, S7 transmits 2 different kinds or signals, or 4 kinds of signals in total and the output unit discriminates them with discriminating means and produces outputs corresponding to the signals.
Next, FIG. 13 and FIG. 15 indicate the fifth example of the push-button switch device. The switch unit 41 of the push-button switch device 40 of this example indicates utilization of a transformed 3-stage push-button switch. The switch unit 41 is provided with 2 push-button switches PB7, PB8. While the respective first contacts 43, 44 of those push-button switches PB7, PB8 close individually, the second and the third contacts 45, 46 are designed to close if either of the push-button switches is pressed down. An example is given in FIG. 15.
This switch unit 41 is realized by inserting push buttons 51, 52 at a certain distance between them in a case 50. The two push buttons have a same structure. Therefore, one push button 51 will be explained hereafter while the other push button 52 will be given with a suffix "a" attached to a same symbol for a same part, but the explanation for it will be omitted.
This push button 51 is provided with a contactor 54 of rectangular shape to be inserted in a slit 53. The contactor 54 is braced down into the slit by a spring 55 and the push button 51 itself is also braced at the head in the direction protruding from the case 50 by a spring 56. 57, 57a indicate left and right contacts. 58 indicates a projection protruding from the push button 51 to the side of the other push button 52 while 60 indicates an intermediate switch provided between the two push buttons 51, 52. The intermediate switch 60 is braced to the side of the projections 58, 58a by a spring 61. Long and short slits 62, 63 are formed in this intermediate switch 60 and rectangular contactors 64, 65 are inserted in those slits and braced to the bottom face side of the slits by springs 66, 67. 70, 70a indicate left and right contacts for the contactor 64 inserted in the slit 62 while 71, 71a indicate left and right contacts for the contactor 65 inserted in the slit 63. 59, 59a are left and right contacts for the contactor 54a on the side of the other push button 52.
In such a structure, the contactor 54 connects the contacts 57, 57a with pressing down of the first stage of the push button 51. Moreover, the contactor 54 connects the contacts 59, 59a with pressing down of the first stage of the push button 52. Next, pressing down of the second stage of the push button 51 or 52 presses down the intermediate switch 60, and the contactor 64 in the slit 62 connects the contacts 70, 70a. With further pressing down of the push button 51 or 52, the contactor 65 in the short slit 63 connects the contacts 71, 71a. The contacts 57, 57a in this case correspond to the contact 44, contacts 59, 59a to contact 44, contacts 70, 70a to contact 45 and contacts 71, 71a to contact 46. This case 50 houses diodes to be described later, but illustration of such diodes is omitted.
The switch unit 41 is provided with 3 diodes D1, D2, D3 in addition to the respective push-button switches PB7, PB8 and the respective diodes are connected as shown in the drawing. The outputs to transmitting lines S8, S9 by this connection are as shown in FIG. 14. The output unit 42 may be realized with a structure as shown in FIG. 12.
Next, FIG. 16 to FIG. 18 indicate the sixth example of the push-button switch device. The push-button switch device 80 of this example consists of a switch unit 81 and an output unit 82. The switch unit 81 is constituted by 3-stage push-button switches PB9, PB10, which make outputs by combination of 2 contacts, and 3 diodes D1, D2, D3. Namely, the push-button switches PB9, PB10 are 3-stage switches provided each with first contacts 83, 85 and second contacts 84, 86, and neither contact is turned on during a state (i.e., zero stage) in which the push-button switch PB9 is not pushed down. The first contact 83 is turned on with pressing down of the first stage of the push-button switch PB9 and the first and second contacts 83, 84 are turned on with pressing down of the second stage. With further pressing down of the third stage, the first contact is turned off and only the second contact 84 is turned on. The same is true with the other push-button switch PB10. The diode D1 is mounted in the direction opposite to that of the other diodes D2, D3.
With such an arrangement, the outputs obtained with the closing of respective contacts are those of pulsating signal current of positive half-wave rectification, alternating waveform signal current and pulsating signal current of negative half-wave rectification as shown in FIG. 17 which are obtained in order. The respective contacts 83, 84 of the push-button switch PB9 are connected to the output unit 82 through a common transmitting line S10 while respective contacts 85, 86 of the push-button switch PB11 are connected to the output unit 82 through a common transmitting line S11.
FIG. 18 indicates the output unit 82. In the interface circuit of this output unit 82, 2 discriminating means PC14, PC15 are provided on the transmitting line S10 and 2 discriminating means PC16, PC17 are provided on the transmitting line S11, respectively, to apply signals to comparators CR14-CR17 through an integrating circuit of resistors and capacitors, respectively. Namely, this example is realized in such a way that the 4 kinds of signals by the push-button switch PB9 are transmitted to the output unit through one transmitting line S11, the 4 kinds of signals by the push-button switch PB10 are transmitted to the output unit through one transmitting line S12 respectively, and that the output unit 82 discriminates those signals and transmits output signals according to such signals. | A switch unit receive an AC signal and includes first and second push-button switches and at least one rectifying diode. Each of the first and second push-button switches is a 2-stage switch or a 3-stage switch. The first and second push-button switches and the at least one rectifying diode are configured such that the switch unit selectively generates any one of a non-signal, a positive half-wave rectified signal, a negative half-wave rectified signal and a full wave alternating signal to first and second outputs. The first and second outputs of the switch units are transmitted to an output unit by way of two transmission wires, respectively. The output unit discriminates the switching state of the first and second push-button switches based on the signal received from the switch unit via the two transmission wires. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Patent Application No. 60/751,660, filed Dec. 20, 2005, entitled “Flux and Process For Hot Dip Galvanization”, and U.S. Provisional Patent Application No. 60/810,173, filed Jun. 2, 2006, entitled “Flux and Process For Hot Dip Galvanization”, the entire contents of which applications are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to a flux for the treatment of ferrous metals, e.g. in the form of iron or steel articles, prior to coating by dipping in molten zinc or zinc alloys. The invention is intended for application in hot dip galvanizing operations with kettles or baths holding zinc-aluminum alloys which may contain other components. The invention may also be applied to other zinc alloy systems.
BACKGROUND OF THE INVENTION
[0003] Zinc alloy coatings, having a high level of aluminum, impart increased corrosion protection to ferrous metals and improve formability as well as paintability, compared to conventional hot-dip zinc alloys. However, a high concentration of aluminum makes the coating process very sensitive to metal surface conditions. Consequently, the successful application of aluminum-rich zinc alloy coatings has been limited to some relatively expensive and sophisticated processes, such as the double dip process with standard galvanizing preceding an aluminum-zinc coating, using a suitable alloy such as GALFAN™, a trademark of International Lead Zinc Research Organization, Inc., which contains nominally 5% Al; the electro-fluxing process whereby electroplating with a thin zinc layer precedes the GALFAN™ alloy coating; and the hot process where a furnace with a reducing atmosphere is used before applying the GALFAN™ alloy coating.
[0004] Coating problems also persist at much higher aluminum concentrations (such as eutectoid compositions containing 22% Al) and with various other zinc alloy bath compositions (such as those containing vanadium, manganese, magnesium, silicon, tin, bismuth and nickel). Such specialty alloys are found to be incompatible with conventional zinc chloride/ammonium chloride fluxes. Certain patents, such as U.S. Pat. No. 6,200,636 and U.S. Pat. No. 6,284,122, attempt to deal with coating issues by deposition of a metallic layer by cementation on the steel surface. However, the successful application of such a method depends on cementing a layer of copper requiring a pristinely clean steel surface which is very difficult to achieve in practice.
[0005] Numerous attempts to apply GALFAN™ alloy coating in a traditional single-stage process have failed. Conventional fluxes used for aluminum-rich zinc alloy hot-dip galvanizing have resulted in uncoated spots, pinholes, surface roughness and bad adhesion. Special fluxes have been developed to overcome these problems. For example, U.S. Pat. No. 1,914,269 describes a galvanizing flux composition which contains ammonium chloride, zinc chloride and fluorine compounds. U.S. Pat. No. 3,806,356 discloses a pre-flux containing various combinations of fluorosilicic acid, hydrochloric acid, hydrofluoric acid, potassium fluoride and zinc chloride. U.S. Pat. No. 4,496,612 proposes an aqueous flux based on zinc chloride, ammonium chloride and from 0.6 to 3.0% fluoride ions. All of these fluxes contain acutely toxic fluorides which are hazardous to workers and the environment.
[0006] U.S. Pat. No. 4,802,932 discloses a fluoride-free top flux for kettles containing 80 to 90% ZnCl 2 ; 0 to 20% NH 4 Cl; and, based on the weight of ZnCl 2 +NH 4 Cl, 0.01 to 5% of a wetting agent, 0 to 5% of a foaming agent, and 0 to 5% of a soluble salt of rare earths.
[0007] EP 0 488 423 B1 suggests an aqueous flux composition which comprises 10 to 50% by weight of zinc chloride and/or stannous chloride; 1 to 20% by weight of at least one alkali metal chloride or alkaline earth metal chloride; and 0.1 to 30% by weight of at least one alkyl quaternary ammonium salt wherein the alkyl groups have 1 to 18 carbons.
[0008] The flux formulations of the above-cited U.S. Pat. No. 4,802,932 and EP 0 488 423 B1 were tested on galvanizing with GALFAN™ coatings but none of them gave good results with the coatings having high roughness, pinholes and sometimes uncoated (bare) spots.
[0009] The present invention is based on analysis of the chemical processes at the surface of steel samples after pickling in acid and fluxing. It is common practice to rinse articles with water after pickling in preparation for galvanizing. While advancing to the fluxing tank, moist surfaces, which have become very active by pickling, are exposed to air. Even though the articles are carefully washed, some iron salts still remain on the surface. Therefore, the surfaces after pickling may have active iron atoms and molecules of FeCl 2 which are rapidly converted by air into FeOHCl and Fe(OH) 2 . Applicant has found that at least one of these compounds, Fe(OH) 2 , cannot be dissolved in flux solution at pH>1.5. Consequently the surfaces contain Fe(OH) 2 which reacts with aluminum in the molten zinc-aluminum alloy, creating aluminum oxides, which are not wetted by the molten alloy, according to the following reaction:
3Fe(OH) 2 +4Al→3Fe+2Al 2 O 3 +3H 2 (1)
[0010] This peculiar feature of galvanizing in the presence of aluminum results in unsatisfactory coatings with bare spots and pinholes.
BRIEF SUMMARY OF THE INVENTION
[0011] Applicant has found that maintaining a flux pH of less than about 1.5 leads to gradual Fe(OH) 2 dissolution and that the rate of this dissolution is accelerated by the presence of FeCl 3 in the flux. After treatment in such a flux, steel samples do not have oxygen-containing compounds on the surface, eliminating a significant problem related to hot dip galvanizing with high aluminum alloys, namely aluminum oxides on the steel surfaces.
[0012] The present invention provides aqueous flux formulations such that steel articles can more easily be coated with zinc-aluminum alloys, such as GALFAN™ alloy, as well as with other zinc-aluminum alloys with much higher aluminum concentrations (such as eutectoid compositions containing 22% Al), or with various other zinc alloy compositions (such as those containing vanadium, manganese, magnesium, silicon, tin, bismuth and nickel).
[0013] According to one aspect of the invention there is provided an aqueous flux for hot dip galvanization comprising from about 15 to 40 weight % zinc chloride, about 1 to 10 weight %, preferably about 1 to 6 weight %, ammonium chloride, about 1 to 6 weight % of an alkali metal chloride, about 0.02 to 0.1 weight % of a nonionic surfactant containing, polyoxyethylenated straight-chain alcohols with a hydrophile-lipophile balance (HLB) of less than 11, and including an acidic component so that the flux has a pH of about 1.5 or less.
[0014] According to another aspect of the invention there is provided an aqueous flux for hot dip galvanization comprising from about 15 to 40 weight % zinc chloride, about 1 to 10 weight %, preferably about 1 to 6 weight %, ammonium chloride, about 1 to 4 weight % ferric chloride, about 1 to 6 weight % of an alkali metal chloride, about 0.02 to 0.1 weight % of a nonionic surfactant containing polyoxyethylenated straight-chain alcohols with a hydrophile-lipophile balance (HLB) of less than 11, about 0.1 to 0.2 weight % of an inhibitor containing an amino derivative, and including an acidic component so that the flux has a pH of about 1.5 or less.
[0015] The flux may further comprise bismuth, such as in the form of bismuth oxide, or other suitable bismuth compound, such as bismuth chloride or bismuth oxychloride. The flux may contain Bi 2 O 3 in an amount of at least about 0.02 weight % Bi 2 O 3 or more, preferably about 0.05%.
[0016] According to a further aspect of the invention, there is provided an aqueous flux for hot dip galvanization of cold rolled steel comprising from about 15 to 40 weight % zinc chloride, about 1 to 10 weight % ammonium chloride, about 1 to 6 weight % of an alkali metal chloride, about 0.02 to 0.1 weight % of a nonionic surfactant containing polyoxyethylenated straight-chain alcohols with a hydrophile-lipophile balance (HLB) of less than 11, and including an acidic component so that the flux has a pH of about 1.5 or less.
[0017] According to another aspect of the invention, there is provided an aqueous flux for hot dip galvanization of cold rolled steel comprising from about 15 to 40 weight % zinc chloride, about 1 to 10 weight % ammonium chloride, about 1 to 4 weight % ferric chloride, about 1 to 6 weight % of an alkali metal chloride, about 0.02 to 0.1 weight % of a nonionic surfactant containing, polyoxyethylenated straight-chain alcohols with a hydrophile-lipophile balance (HLB) of less than 11, about 0.1 to 0.2 weight % of an inhibitor containing an amino derivative, and including an acidic component so that the flux has a pH of about 1.5 or less.
[0018] As will be further elaborated on below, the HLB number is a measure of the ratio of hydrophilic and lipophilic (hydrophobic) characteristics of the surfactant molecule.
[0019] A surfactant such as MERPOL™ SE has been found to be suitable.
[0020] Also according to the invention there is provided a process for the hot dip galvanization of an iron or steel article comprising the steps pretreating the article in a fluxing bath containing a flux as described above and subsequently dipping the article in a hot dip galvanizing bath to form a coating thereon.
[0021] The galvanizing bath may contain Zn or a Zn alloy, such as a zinc-aluminum alloy containing above about 0.02 weight % aluminum, for example containing about 5% Al and about 95% Zn, or up to about 23% of Al or more.
[0022] Instead the galvanizing bath may also contain another alloy, such as a zinc-aluminum-magnesium alloy, a zinc-aluminum-silicon alloy or a zinc-tin-bismuth-vanadium alloy.
[0023] The invention also extends to an article provided with a coating by means of a process as herein described.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The main reactions between aluminum and conventional flux on steel surfaces are:
3H 2 O+2Al→Al 2 O 3 +3H 2 (2)
3Fe(OH) 2 +4Al→3Fe+2Al 2 O 3 +3H 2 (3)
2Fe(OH) 3 +4Al→2Fe+2Al 2 O 3 +3H 2 (4)
3ZnCl 2 +2Al→3Zn+2AlCl 3 (5)
6NH 4 Cl+2Al→2AlCl 3 +6NH 3 +3H 2 (6)
[0025] The first three reactions create aluminum oxides on the pickled steel surface, which are not wetted by molten zinc and are the cause of bare spots on the surface.
[0026] Aluminum also reacts with oxygen absorbed on the pre-fluxed surface of the steel:
3O 2 +4Al→2Al 2 O 3 (7)
[0027] These aluminum oxides become mixed with melted flux on the steel surface, increasing its viscosity and making flux removal from the surface more difficult. As result, the coating has black spots. The result of reactions (5) and (6) is gaseous aluminum chloride which mechanically interacts with viscous flux on the steel surface, resulting in roughness and lumpiness.
[0028] To prevent or dramatically reduce aluminum oxide formation, the flux of the present invention has a reduced pH, in the range of about 1.5 or below. According to equation (8), the flux dissolves the ferrous hydroxides on the steel surface, which are formed in air after rinsing. Low pH also prevents oxidation of the surface after fluxing and during drying in a preheating oven, according to equation (9):
Fe(OH) 2 +2HCl=FeCl 2 +2H 2 O (8)
2Fe+4HCl+O 2 →2FeCl 2 +2H 2 O (9)
[0029] It has been found that ferric chloride in the flux helps to reduce the time of Fe(OH) 2 dissolution to 3 to 10 seconds.
[0030] It is common to use corrosion inhibitors in pickling tanks. In the present invention an inhibitor is included in the acidic flux to reduce the rate of iron dissolution. According to the test data, amino derivatives can reduce the rate of iron accumulation in fluxes by two to three times. Aliphatic alkyl amines (preferably C 1 -C 12 alkyls) are examples of useful amino compounds. Specific examples are hexamethylenediamine tetra, hexapotassium hexamethylenediamine and alkyldimethyl quaternary ammonium nitrate. An inhibitor such as ARQUAD™, a trademark of Union Carbide, USA, which contains an alkyltrimethyl ammonium chloride, has been found suitable.
[0031] The alkali metal chloride components of the flux may be lithium chloride, potassium chloride or sodium chloride or mixtures of these. These chlorides improve the fluidity of the flux and contribute to better melting of the flux on the steel surface. The additional role of alkali chlorides is to bind gaseous aluminum chloride according to reaction (10), lessening its influence on pinhole formation and surface roughness.
MCl+AlCl 3 =M(AlCl 4 ) (10)
where M is Li, K or Na.
[0032] In accordance with reaction (6), it should be noted that ammonium chloride is decomposed at the coating temperature and the gaseous products of decomposition bubble onto the surface of steel immersed in the molten bath, thereby removing flux waste from the surface.
[0033] The specific action of surfactants derived from polyoxyethylenated straight-chain alcohols with an HLB<11 is not well understood. The HLB number represents a fundamental property of nonionic surfactants that correlates with physical properties and surface-active effects. The HLB number is a measure of the ratio of hydrophilic and lipophilic (hydrophobic) characteristics of the surfactant molecule. The surfactants indicated herein help produce bright, lustrous coatings. Using surfactants with other chemical characteristics or with the same characteristics, but with an HLB>11, did not produce positive effects. In some cases, the coating quality was actually worse.
[0034] Both cold rolled and hot rolled steels are used in conventional hot dip galvanizing. Cold rolled steel is usually easier to process and galvanize without defects (bare spots) because its surface is free of scale when it arrives at the plant and smoother than that of hot rolled steel. The mill scale on the surface of the hot rolled steel tends to absorb forming lubricants that are more difficult to remove in the degreaser and can affect subsequent pickling of the steel. The hot rolled steel surfaces are also rougher and the role of the flux is more demanding for producing defect free coatings. Thus, when testing the effectiveness of the various fluxes in producing smooth, continuous coatings without bare spots both cold rolled and hot rolled steels where used in the tests described below.
EXAMPLES
[0035] The following procedures were used for the examples 1 to 8 below. Cold rolled steel panels, measuring 3×70×100 mm in size, were cleaned, pickled, rinsed, and then immersed in aqueous flux solutions at temperatures of 20 to 30° C. After fluxing, the panels were dried in an electric oven for 3 minutes until the panels reached a surface temperature of 100 to 110° C. The panels were then hot dip galvanized by immersion in zinc-aluminum alloys containing 5% Al and 95% Zn for 2 minutes at a temperature of 450 to 455° C.
Example 1
[0036] In this example, an aqueous flux comprising 25% ZnCl 2 and 3.5% NH 4 Cl was used. The fluxing time was 40 seconds.
[0037] After hot dip galvanizing, the coating was rough and had bare spots, pinholes and spots of flux on the surface.
Example 2
[0038] Example 1 was repeated with the addition of 3% KCl to the aqueous flux.
[0039] After hot dip galvanizing, the coating was much smoother and had less bare spots and pinholes compared to that of Example 1.
Example 3
[0040] Example 2 was repeated with the aqueous flux pH adjusted downward to 0.6 by addition of hydrochloric acid.
[0041] The coating after hot dipping was smooth and had no bare spots or pinholes, but it was not bright and lustrous.
Example 4
[0042] Example 3 was repeated with the addition of 0.04% alcohol ethoxylate/propoxylate surfactant, such as MERPOL™ SE surfactant, to the aqueous flux.
[0043] The coating was bright and lustrous, without any defects.
Example 5
[0044] Example 4 was repeated except that the fluxing time was 3 seconds instead of 40 seconds.
[0045] The coating was bright and lustrous with a small number of pinholes.
Example 6
[0046] Example 5 was repeated with the addition of 2% FeCl 3 to the aqueous flux.
[0047] The coating was bright and lustrous, without any defects.
Example 7
[0048] Example 6 was repeated with the addition of 0.2% inhibitor, ARQUAD™ 12-50 (a trademark of Union Carbide, USA), which contains an alkyltrimethyl ammonium chloride.
[0049] The coating was similar in quality to that of Examples 4 and 6.
Example 8
[0050] Example 7 was repeated except that 4% NaCl was used, instead of 3% KCl.
[0051] The coating was similar in quality to that of Examples 4, 6 and 7.
[0052] The purpose of the tests, shown as examples 9 to 14 below, was to demonstrate the effectiveness of three flux compositions on both cold rolled and hot rolled steel dipped in a similar alloy as in examples 1 to 8.
Example 9
[0053] In this example, a conventional commercial “double salt” flux, namely an aqueous flux comprising 13.75% ZnCl 2 and 11.25% NH 4 Cl, was used. The flux time was 2 minutes at a temperature of 70° C. The steel sample was hot rolled steel.
[0054] After hot dip galvanizing, the coating was rough and did not cover most of the sample. There was a large portion of bare spots.
Example 10
[0055] Example 9 was repeated with the exception of the steel sample, which was cold rolled steel.
[0056] After hot dip galvanizing, the coating was rough with some shiny spots, but mostly a cloudy appearance. The coating covered the entire sample but had a poor appearance.
[0057] As can be seen, the flux produced marginal results on the cold rolled steel, and unacceptable results on the hot rolled steel.
Example 11
[0058] In this example, an aqueous flux comprising 25% ZnCl 2 , 4% NH 4 Cl, 4% KCl, 0.04% MERPOL™ SE surfactant and 0.4% hydrochloric acid, was used, so that the flux had a pH<1.5. The flux time was 45 seconds at a temperature between 20-30° C. The steel sample was hot rolled steel.
[0059] After hot dip galvanizing, the coating was rough with some shiny spots but mostly a cloudy appearance. The coating did not cover the entire sample.
Example 12
[0060] Example 11 was repeated with the exception of the steel sample, which was cold rolled steel.
[0061] After hot dip galvanizing, the coating was smooth and shiny with some cloudy spots. There were no bare spots on the sample and the quality appeared to be good.
[0062] As can be seen, the flux produced good results on the cold rolled steel, but results on the hot rolled steel were marginal.
Example 13
[0063] Example 11 was repeated with the addition of 0.05% Bi 2 O 3 in the flux.
[0064] After hot dip galvanizing, the coating was smooth and shiny with a spangle pattern. There were no bare spots on the sample and the quality appeared to be very good.
Example 14
[0065] Example 13 was repeated with the exception of the steel sample, which was cold rolled steel.
[0066] After hot dip galvanizing, the coating was smooth and shiny with a spangle pattern. There were no bare spots on the sample and the quality appeared to be very good.
[0067] As can be seen, the flux with an addition of Bi 2 O 3 produced good results on both the cold rolled and hot rolled steel.
[0068] The tests shown as examples 15 to 27 below were performed to demonstrate the effectiveness of a flux also containing Bi 2 O 3 when galvanizing with Zn—Al alloys containing aluminum levels ranging from 5% to 18% Al, and Si levels ranging from 0.01%-0.15% Si.
[0069] The results of these experiments showed that the flux produced commercially acceptable coatings, free of defects on hot rolled steels with all the alloy compositions.
[0070] The following procedures were used for the examples 15 to 27 below. Hot rolled steel panels, measuring 4×3×⅛ inches in size, were degreased, pickled, rinsed and then immersed in an aqueous flux solution comprising 25% ZnCl 2 , 4% NH 4 Cl, 4% KCl, 0.04% MERPOL™ SE surfactant, 0.4% hydrochloric acid (so that the flux has a pH<1.5) and 0.05% Bi 2 O 3 for 45 seconds at a temperature of 20-30° C. The panels were dried in an electric oven for 5 minutes at a temperature of 140° C. The panels were then hot dip galvanized by an immersion speed of 1½ ft/min for 6 minutes.
Example 15
[0071] In this example, the bath alloy was special high grade (SHG) Zn. The samples were dipped at a temperature of 450-455° C.
[0072] After hot dip galvanizing, the coating was smooth and shiny. There were no bare spots and the quality appeared to be very good.
Example 16
[0073] In this example, the bath alloy was 95% Zn and 5% Al. The samples were dipped at a temperature of 450-455° C.
[0074] After hot dip galvanizing, the coating appeared smooth and shiny with a small spangle pattern. There were no bare spots and the quality appeared to be very good.
Example 17
[0075] In this example the bath alloy was 95% Zn, 5% Al and 0.01% Si. The samples were dipped at a temperature of 485-490° C.
[0076] After hot dip galvanizing, the coating was smooth and shiny. There were no bare spots and the quality appeared to be very good.
Example 18
[0077] In this example, the bath alloy was 95% Zn, 5% Al and 0.03% Si. The samples were dipped at a temperature of 505-510° C.
[0078] After hot dip galvanizing, the coating was smooth and shiny. There were no bare spots and the quality appeared to be very good.
Example 19
[0079] In this example, the bath alloy was 88% Zn, 12% Al and 0.01% Si. The samples were dipped at a temperature of 470-475° C.
[0080] After hot dip galvanizing, the coating was smooth with a grayish color. There were no bare spots and the quality appeared to be very good.
Example 20
[0081] In this example, the bath alloy was 88% Zn, 12% Al and 0.03% Si. The samples were dipped at a temperature of 490-495° C.
[0082] After hot dip galvanizing, the coating was smooth with a grayish color. There were no bare spots and the quality appeared to be very good.
Example 21
[0083] In this example, the bath alloy was 88% Zn, 12% Al and 0.06% Si. The samples were dipped at a temperature of 510-515° C.
[0084] After hot dip galvanizing, the coating was smooth with a grayish color. There were no bare spots and the quality appeared to be very good.
Example 22
[0085] In this example, the bath alloy was 88% Zn, 12% Al and 0.15% Si. The samples were dipped at a temperature of 475-480° C.
[0086] After hot dip galvanizing, the coating was smooth and shiny with a small spangle pattern. There were no bare spots and the quality appeared to be very good.
Example 23
[0087] In this example, the bath alloy was 85% Zn and 15% Al. The samples were dipped at a temperature of 470-475° C.
[0088] After hot dip galvanizing, the coating was very rough with a grayish color. There were no bare spots throughout the rough thick coating.
Example 24
[0089] In this example, the bath alloy was 85% Zn, 15% Al and 0.01% Si. The samples were dipped at a temperature of 460-465° C.
[0090] After hot dip galvanizing, the coating was smooth with a grayish color. There were no bare spots and the quality appeared to be very good.
Example 25
[0091] In this example, the bath alloy was 85% Zn, 15% Al and 0.02% Si. The samples were dipped at a temperature of 480-485° C.
[0092] After hot dip galvanizing, the coating was smooth with a grayish color. There were no bare spots and the quality appeared to be very good.
Example 26
[0093] In this example, the bath alloy was 85% Zn, 15% Al and 0.04% Si. The samples were dipped at a temperature of 510-515° C.
[0094] After hot dip galvanizing, the coating was smooth with a grayish color. There were no bare spots and the quality appeared to be very good.
Example 27
[0095] In this example the bath alloy was 82% Zn, 18% Al and 0.01% Si. The samples were dipped at a temperature of 500-505° C.
[0096] After hot dip galvanizing, the coating was very rough with a grayish color. There were no bare spots with the exception of the rough thick coating.
[0097] The tests shown as examples 28 to 33 below were performed to compare the effectiveness of three fluxes when galvanizing cold rolled and hot rolled steels in a Zn-23% Al alloy.
[0098] The following procedures were used for the examples 28 to 33 below. Hot rolled and cold rolled steel panels measuring 4×3×⅛ inches in size were degreased, pickled, rinsed and then immersed in aqueous flux solutions. The panels were dried in an electric oven for 5 minutes at a temperature of 140° C. The panels were then hot dip galvanized by immersion of 2 ft/min in an alloy containing 77% Zn and 23% Al for 2 minutes at a temperature of 540 to 545° C.
Example 28
[0099] In this example, a conventional commercial “double salt” flux, namely an aqueous flux comprising 13.75% ZnCl 2 and 11.25% NH 4 Cl, was used. The flux time was 2 minutes at a temperature of 70° C. The steel panels used were hot rolled.
[0100] After hot dip galvanizing, there was very little coverage and most of the steel was exposed.
Example 29
[0101] Example 28 was repeated with cold rolled steel panels.
[0102] After hot dip galvanizing, there was very little coverage and most of the steel was exposed.
[0103] As can be seen, the flux produced unacceptable results.
Example 30
[0104] In this example, an aqueous flux comprising 25% ZnCl 2 , 4% NH 4 Cl, 4% KCl, 0.04% MERPOL™ SE surfactant and 0.4% hydrochloric acid, so that the flux has a pH<1.5, was used. The flux time was 45 seconds at a temperature between 20-30° C. The steel panels used were hot rolled.
[0105] After hot dip galvanizing, the coating was rough and did not cover most of the sample. There was a large portion of bare spots.
Example 31
[0106] Example 30 was repeated with cold rolled steel panels.
[0107] After hot dip galvanizing, the coating was rough and did not cover most of the sample. There was a large portion of bare spots.
[0108] As can be seen, the flux did not produce acceptable results with an alloy containing 23% by weight of Al on both hot and cold rolled steels
Example 32
[0109] Example 30 was repeated with the addition of 0.05% Bi 2 O 3 to the aqueous flux. The steel panels used were hot rolled steel.
[0110] After hot dip galvanizing, the coating was rough with a grayish color. There were no bare spots on the sample.
Example 33
[0111] Example 32 was repeated with cold rolled steel panels.
[0112] After hot dip galvanizing, the coating was rough with a grayish color. There were no bare spots on the sample.
[0113] As can be seen the flux with the addition of Bi 2 O 3 produced good results.
[0114] The purpose of the tests, shown as examples 34 to 39 below, was to demonstrate the effectiveness of three different flux compositions for galvanizing with a Zn—Sn—Bi—V alloy such as described in U.S. Pat. No. 6,280,795, the entire contents of which is incorporated herein by reference. The purpose of this alloy is for controlling steel reactivity during galvanizing of hot rolled, high silicon containing steels. Past work had showed that the use of conventional fluxes with this alloy produced coatings with bare spots.
[0115] As will be seen from Example 37 below, samples of cold rolled steel galvanized with this alloy produced good coatings with the flux of Example 36 without the addition of Bi 2 O 3 .
[0116] The following procedures were used for the examples below. Hot rolled and cold rolled steel panels, measuring 4×3×⅛ inches in size, were degreased, pickled, rinsed and then immersed in aqueous flux solutions. The panels were dried in an electric oven for 5 minutes. The panels were then hot dip galvanized by immersion of 3 ft/min in an alloy containing 98.9% Zn, 1% Sn, 0.1% Bi, 0.005% Al and 0.035% V for 4 minutes at a temperature of 440 to 445° C.
Example 34
[0117] In this example, a conventional commercial “double salt” flux was used, namely an aqueous flux comprising 13.75% ZnCl 2 and 11.25% NH 4 Cl. The flux time was 2 minutes at a temperature of 70° C. The steel sample was hot rolled steel.
[0118] After hot dip galvanizing, the coating was smooth and shiny with a spangle pattern. However, there were several small bare spots on the sample.
Example 35
[0119] Example 34 was repeated with the exception of the steel sample, which was cold rolled steel.
[0120] After hot dip galvanizing, the coating was smooth and shiny with a spangle pattern. There were no bare spots on the sample and the quality appeared to be very good.
Example 36
[0121] In this example, an aqueous flux comprising 25% ZnCl 2 , 4% NH 4 Cl, 4% KCl, 0.04% MERPOL™ SE surfactant and 0.4% hydrochloric acid, so that the flux has a pH<1.5, was used. The flux time was 45 seconds at a temperature between 20-30° C. The steel sample was hot rolled steel.
[0122] After hot dip galvanizing, the coating was smooth and shiny with a spangle pattern. There were several small bare spots on the sample but fewer bare spots than in Example 34.
Example 37
[0123] Example 36 was repeated with the exception of the steel sample, which was cold rolled steel.
[0124] After hot dip galvanizing, the coating was smooth and shiny with a spangle pattern. There were no bare spots on the sample and the quality appeared to be very good.
Example 38
[0125] Example 36 was repeated with the addition of 0.05% Bi 2 O 3 to the flux.
[0126] After hot dip galvanizing, the coating was smooth and shiny with a spangle pattern. There were no bare spots on the sample and the quality appeared to be very good.
Example 39
[0127] Example 38 was repeated with the exception of the steel sample, which was cold rolled steel.
[0128] After hot dip galvanizing, the coating was smooth and shiny with a spangle pattern. There were no bare spots on the sample and the quality appeared to be very good.
[0129] The purpose of the tests shown as examples 40 to 42 below, was to demonstrate the effectiveness of three flux compositions for galvanizing with a Zn—Al—Mg alloy.
[0130] The following procedures were used for these examples. Hot rolled steel panels, measuring 4×3×⅛ inches in size, were degreased, pickled, rinsed and then immersed in aqueous flux solutions. The panels were dried in an electric oven for 5 minutes at a temperature of 100° C. The panels were then hot dip galvanized by immersion at a rate of 3 ft/min in an alloy containing 94.7% Zn, 5% Al and 0.3% Mg for 2 minutes at a temperature of 430 to 435° C.
Example 40
[0131] In this example the aqueous flux comprised 13.75% ZnCl 2 and 11.25% NH 4 Cl. The flux time was 2 minutes at a temperature of 70° C.
[0132] After hot dip galvanizing, the coating was rough and did not cover most of the sample. There was a large portion of bare spots.
Example 41
[0133] In this example the aqueous flux comprised 25% ZnCl 2 , 4% NH 4 Cl, 4% KCl and 0.4% hydrochloric acid so that the flux has a pH<1.5. The flux time was 45 seconds at a temperature between 20-30° C.
[0134] After hot dip galvanizing, the coating was shiny but had bare spots. The coating did not cover the entire sample. However, it was an improvement to the previous example.
Example 42
[0135] Example 41 was repeated with the addition of 0.05% Bi 2 O 3 and 0.05% MERPOL™ SE surfactant.
[0136] After hot dip galvanizing, the coating was smooth and shiny. There were no bare spots on the sample and the quality appeared to be very good.
[0137] It can be seen from the above results that the addition of KCl and HCl so that the pH<1.5 gave improved, although not yet entirely acceptable results and that the addition of Bi 2 O 3 and the MERPOL™ SE surfactant resulted in a good quality product.
[0138] From the above it will be clear that a suitable flux can be tailored according to the article to be coated, e.g. whether it is cold rolled or hot rolled steel, as well as the particular alloy with which the coating is to be effected. It can be seen that in cases where the article is of a type that is more difficult to coat or, for example, in cases where an alloy with a high aluminum content is to be used, the presence of bismuth in the flux is required, whereas in less demanding cases, the presence of bismuth is not required. A flux can therefore be selected as dictated by the specific requirements in a particular case.
[0139] Although certain preferred embodiments of the present invention have been shown and described in detail, it should be understood that various changes and modifications may be made therein without departing from the scope of the appended claims.
[0140] The claims which follow are to be considered an integral part of the present disclosure. The term “comprises” or “comprising”, as used herein and in the claims, has its customary non-restrictive meaning which denotes that in addition to any items to which the term relates, there may be included additional items not specifically mentioned. | A flux for use in a hot dip galvanization process has an acidic component so that the flux has a pH of about 1.5 or less. The flux also includes an alkali metal chloride and a nonionic surfactant containing polyoxyethylenated straight-chain alcohols with a hydrophile-lipophile balance (HLB) of less than 11. Depending on the particular application, the flux also includes other components, such as ferric chloride, an inhibitor containing an amino derivative and bismuth oxide. | 1 |
TECHNICAL FIELD
[0001] The principles disclosed herein relate to fiber optic cable systems. More particularly, the present disclosure relates to fiber optic cable systems having breakout arrangements protecting branch cables broken out from main cables.
BACKGROUND
[0002] Passive optical networks are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities to customers. Passive optical networks are a desirable choice for delivering high-speed communication data because they may not employ active electronic devices, such as amplifiers and repeaters, between a central office and a subscriber termination. The absence of active electronic devices may decrease network complexity and/or cost and may increase network reliability.
[0003] FIG. 1 illustrates a network 100 deploying passive fiber optic lines. As shown in FIG. 1 , the network 100 may include a central office 110 that connects a number of end subscribers 115 (also called end users 115 herein) in a network. The central office 110 may additionally connect to a larger network such as the Internet (not shown) and a public switched telephone network (PSTN). The network 100 may also include fiber distribution hubs (FDHs) 130 having one or more optical splitters (e.g., 1-to-8 splitters, 1-to-16 splitters, or 1-to-32 splitters) that generate a number of individual fibers that may lead to the premises of an end user 115 . The various lines of the network can be aerial or housed within underground conduits (e.g., see conduit 105 ).
[0004] The portion of network 100 that is closest to central office 110 is generally referred to as the F 1 region, where F 1 is the “feeder fiber” from the central office. The F 1 portion of the network may include a distribution cable having on the order of 12 to 48 fibers; however, alternative implementations may include fewer or more fibers. The portion of network 100 that includes an FDH 130 and a number of end users 115 may be referred to as an F 2 portion of network 100 . Splitters used in an FDH 130 may accept a feeder cable having a number of fibers and may split those incoming fibers into, for example, 216 to 432 individual distribution fibers that may be associated with a like number of end user locations.
[0005] Referring to FIG. 1 , the network 100 includes a plurality of breakout locations 125 at which branch cables (e.g., drop cables, stub cables, etc.) are separated out from main cables (e.g., distribution cables). Breakout locations can also be referred to as tap locations or branch locations and branch cables can also be referred to as breakout cables. At a breakout location, fibers of the branch cables are typically spliced to selected fibers of the main cable. However, for certain applications, the interface between the fibers of the main cable and the fibers of the branch cables can be connectorized.
[0006] Stub cables are typically branch cables that are routed from breakout locations to intermediate access locations such as a pedestals, drop terminals or hubs. Intermediate access locations can provide connector interfaces located between breakout locations and subscriber locations. A drop cable is a cable that typically forms the last leg to a subscriber location. For example, drop cables are routed from intermediate access locations to subscriber locations. Drop cables can also be routed directly from breakout locations to subscriber locations hereby bypassing any intermediate access locations
[0007] Branch cables can manually be separated out from a main cable in the field using field splices. Field splices are typically housed within sealed splice enclosures. Manual splicing in the field is time consuming and expensive.
[0008] As an alternative to manual splicing in the field, pre-terminated cable systems have been developed. Pre-terminated cable systems include factory integrated breakout locations manufactured at predetermined positions along the length of a main cable (e.g., see U.S. Pat. Nos. 4,961,623; 5,125,060; and 5,210,812). However, the installation of pre-terminated cables can be difficult. For example, for underground applications, pre-terminations can complicate passing pre-terminated cable through the underground conduit typically used to hold fiber optic cable (e.g., 1.25 inch inner diameter conduit). Similarly, for aerial applications, pre-terminations can complicate passing pre-terminated cable through aerial cable retention loops.
SUMMARY
[0009] Certain aspects of the disclosure relate to a breakout process for pre-terminating branch cables to fiber optic distribution cables.
[0010] A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a prior art passive fiber optic network;
[0012] FIG. 2 is a side view of a tether branching from a distribution cable;
[0013] FIG. 3 is a cross sectional view of an example distribution cable;
[0014] FIG. 4 is a cross sectional view of an example tether;
[0015] FIG. 5 is a perspective view of an example breakout assembly installed on a distribution cable at breakout location;
[0016] FIG. 6 is a perspective view of an example retention block used at the breakout location of FIG. 5 ;
[0017] FIG. 7 shows an initial preparation of the distribution cable at the breakout location of FIG. 5 ;
[0018] FIG. 8 shows a first preparation step for a tether used at the breakout location of FIG. 5 ;
[0019] FIG. 9 shows a subsequent preparation step for the tether of FIG. 8 ;
[0020] FIG. 10 is a side view of an enclosure installed at breakout location according to one embodiment of the present disclosure;
[0021] FIG. 11 is a top view of the enclosure of FIG. 10 ;
[0022] FIG. 12 is a flowchart illustrating an example installation process for installing an enclosure over a breakout assembly according to one embodiment of the present disclosure;
[0023] FIG. 13 is a schematic view of a telecommunications cable including a tether branching from a distribution cable.
[0024] FIG. 14 is a flowchart illustrating an example treatment process for preparing a cable to bond with an enclosure body according to one embodiment of the present disclosure; and
[0025] FIG. 15 is a schematic diagram showing respective movement of a cable relative to a plasma etcher during the treatment process of FIG. 14 ;
[0026] FIG. 16 is a flow chart illustrating an example overmolding process for forming the enclosure body according to one embodiment of the present disclosure;
[0027] FIG. 17 is a cross-sectional, schematic view depicting a distribution cable and tether placed within molds during the overmolding process of FIG. 16 ; and
[0028] FIG. 18 is a schematic diagram depicting an enclosure overmolded over a breakout location on a distribution cable of FIG. 17 .
DETAILED DESCRIPTION
[0029] The present disclosure relates to mid-span breakout arrangements provided on distribution cables and methods for providing the breakout arrangements. Each breakout arrangement is provided at a breakout location to protect the optical coupling of a tether (i.e., a branch cable) to a distribution cable.
[0030] Referring now to the figures in general, a typical breakout location 260 is provided at an intermediate point along the length of a distribution cable 220 (e.g., see FIG. 2 ). At the breakout location 260 , a fiber 224 t of a tether 240 is optically coupled to a fiber 224 dc of the distribution cable 220 at a coupling location 205 . An enclosure 300 (e.g., an overmold) is typically provided around the distribution cable 220 and the tether 240 at the breakout location 260 to protect the optical fibers 224 .
[0031] FIG. 3 shows an example distribution cable 220 including six separate buffer tubes 222 each containing twelve fibers 224 dc . The buffer tubes 222 may be gel filled. The distribution cable 220 also includes a central strength member 226 for reinforcing the cable 220 , and an outer strength layer/member 228 , such as aramid fiber/yarn (e.g., Kevlar® fiber), also for reinforcing the cable. The distribution cable 220 further includes an outer jacket 230 that encloses the buffer tubes 222 . Ripcords 232 can be provided for facilitating tearing away portions of the jacket 230 to access the fibers 224 dc within the jacket 230 . A typical distribution cable includes a relatively large number of fibers (e.g., 72, 144 or more fibers). The fibers are typically segregated into separate groups with each group contained within a separate buffer tube. The fibers within each buffer tube can include either ribbon fibers or loose fibers.
[0032] The various aspects of the present disclosure are also applicable to distribution cables having fewer numbers of fibers (e.g., two or more fibers). For example, the distribution cable can include an outer jacket enclosing a single buffer tube and at least two strength members extending on opposite sides of the single buffer tube (not shown). An outer strength layer/member, such as aramid fiber/yarn, can surround the single buffer tube within the jacket. The single buffer tube can enclose loose fibers or ribbon fibers.
[0033] FIG. 4 illustrates an example tether 240 configured to join to the distribution cable 220 at the breakout location 260 . The tether 240 includes a central buffer tube 242 containing multiple fibers 224 t (e.g., typically one to twelve loose or ribbonized fibers). Strength members 246 (e.g., flexible rods formed by glass fiber reinforced epoxy) are positioned on opposite sides of the central buffer tube 242 . An outer jacket 250 surrounds the strength members 246 and the buffer tube 242 . An additional strength layer 248 (e.g., aramid fiber/yarn) can be positioned between the buffer tube 242 and the outer jacket 250 . In the example shown, the tether 240 is depicted as having a flat cable configuration. The outer jacket 250 includes an outer perimeter having an elongated transverse cross-sectional shape. The transverse cross-sectional shape includes oppositely positioned, generally parallel sides 252 interconnected by rounded ends 254 . However, any suitable cable configuration can be utilized for both the distribution cable and the tether cable.
[0034] Referring now to FIG. 5 , one or more tether fibers (e.g., typically less than twelve fibers) 224 t are preferably optically coupled (e.g., spliced) at a coupling location 205 to selected fibers 224 dc of the distribution cable 220 extending from one of the exposed buffer tubes 222 . For clarity, only a single tether fiber 224 t , and distribution cable fiber 224 dc are shown coupled together in the figures. The opposite ends of the tether fibers 224 t are configured to optically couple to a drop terminal or other type of telecommunications equipment (not shown) offset from the breakout location 260 . For example, the tether 240 can terminate in one or more fiber optic connectors (not shown).
[0035] A breakout assembly 200 having features that are examples of inventive aspects in accordance with the principles of the present disclosure is shown installed on a distribution cable in FIG. 5 . The breakout assembly 200 includes a sleeve 202 mounted over the optical fibers 224 t , 224 dc at the coupling location 205 . An optional protective tube 280 can also be provided over the fibers 224 t , 224 dc and the sleeve 202 . An enclosure 300 surrounds the coupled optical fibers 224 dc , 224 t , the sleeve 202 , the optional tube 280 , and the exposed buffer tubes 222 of the distribution cable 220 .
[0036] In general, the enclosure 300 has a body 310 that protects the optical connection between the tether 240 and the distribution cable 220 . One end 302 of a body 310 of the enclosure 300 extends over the distribution cable 220 adjacent a first end 352 of the stripped region 350 and the other end 304 of the body 310 extends over the tether cable 240 and the distribution cable 220 adjacent a second end 354 of the stripped region 350 . The tether 240 generally extends outwardly a length from the enclosure 300 to a connection end 256 . The enclosure 300 can include an overmold.
[0037] When the tether 240 is secured to the distribution cable 220 , the tether 240 should preferably be able to withstand a pullout force of at least one hundred pounds. To meet this pullout force requirement, the breakout assembly 200 also can includes a retention block 270 (see FIG. 6 ) configured to strengthen the mechanical interface between the tether 240 and the distribution cable 220 . Typically, the retention block 270 is enclosed within the protective enclosure 300 .
[0038] As shown at FIG. 6 , the retention block 270 includes a base 274 and a cover 272 between which the fiber 224 t of the tether 240 extends. First and second protrusions 276 , 278 extend from the cover 272 and base 274 , respectively. In one embodiment, the retention block 270 has a polycarbonate construction. Further details regarding the retention block 270 can be found in U.S. provisional application Ser. No. 60/781,280, filed Mar. 9, 2006, and entitled “FIBER OPTIC CABLE BREAKOUT CONFIGURATION,” the disclosure of which is hereby incorporated by reference.
[0039] It is preferred for the fibers 224 t of the tether to be pre-terminated to the fibers 224 dc of the distribution cable. “Pre-terminated” means that the tether fibers 224 t are fused or otherwise connected to the fibers 224 dc of the distribution cable 220 at the factory as part of the cable manufacturing process rather than being field terminated. The remainder of the breakout assembly 200 is also preferably factory installed.
[0040] Referring to FIGS. 7-9 , to prepare the breakout location 260 on the distribution cable 220 , a portion of the outer jacket 230 is first stripped away to provide a stripped region 350 ( FIG. 7 ). In certain embodiments, portions of a cable netting can be removed adjacent the first and second ends 352 , 354 , respectively, so that the buffer tubes 222 are exposed ( FIG. 7 ). The outer strength layer/member 228 also can be displaced (e.g., bunched at one side of the cable 220 ) adjacent the ends 352 , 354 to facilitate accessing the buffer tubes 222 (see, e.g., FIG. 5 ). Tape can be used to prevent the intermediate length of netting that remains at the breakout location 260 from unraveling ( FIG. 7 ).
[0041] One of the buffer tubes 222 is selected and a first window 358 is cut into the selected buffer tube 222 adjacent the first end 352 of the stripped region 350 and a second window 360 is cut into the selected buffer tube 222 adjacent the second end 354 of the stripped region 350 ( FIG. 7 ). The fibers 224 dc desired to be broken out are accessed and severed at the second window 360 . After the fibers 224 dc have been severed, the fibers 224 dc are pulled from the buffer tube 222 through the first window 358 . With the distribution cable 220 prepared as shown in FIG. 7 , the fibers 224 dc are ready to be terminated to one or more fibers 224 t of a prepared tether 240 .
[0042] To prepare the tether 240 to be installed on the prepared distribution cable 220 , a portion of the outer jacket 250 is stripped away to expose the central buffer tube 242 and the strength members 246 (see FIG. 8 ). As shown at FIG. 8 , the central buffer tube 242 and the strength members 246 project outwardly beyond an end 247 of the outer jacket 250 . The strength layer 248 ( FIG. 4 ) is removed from around the buffer tube 242 . After removing the end portion of the outer jacket 250 , the strength members 246 are trimmed as shown at FIG. 8 , and an end portion of the central buffer tube 242 is removed to expose the fibers 224 t ( FIG. 9 ).
[0043] To connect the tether fibers 224 t to the distribution cable fibers 224 dc , the sleeve 202 ( FIG. 5 ) is first slid over the fibers 224 t of the tether. In certain embodiments, the sleeve 202 can be slid up over the buffer tube 242 of the tether 240 . The optional protective tube 280 ( FIG. 5 ) also can be slid over the tether 240 . When the sleeve 202 and protective tube 280 are mounted on the tether 240 , the fibers 224 t of the tether 240 are coupled (e.g., fused) to the fibers 224 dc of the distribution cable 220 . After the coupling process is complete, the sleeve 202 can be slid over the coupling location 205 to protect the fused fibers 224 t , 224 dc . The tube 280 can be slid over the sleeve 202 . The fibers are then tested to confirm that the fibers meet minimum insertion loss requirements.
[0044] If desired, the tether 240 can be mounted to the retention block 270 . For example, as shown at FIG. 9 , the strength members 246 can be positioned within side grooves 273 on the base 274 of the retention block 270 , and the central buffer tube 242 can be inserted within a central groove 275 on the base 274 . In the example illustrated, the central buffer tube 242 has a length that extends beyond a first end of the base 274 , and the strength members 246 have lengths that terminate generally at the first end of the base 274 . After securing the retention block 270 to the distribution cable 220 , one end of the optional protective tube 280 can be mounted over the protrusions 276 , 278 of the retention block 270 (see FIG. 5 ).
[0045] After verifying insertion loss, heat resistant tape is wrapped around the distribution cable 220 , the tether 240 , and the breakout location assembly 200 . Thereafter, the enclosure 300 is applied over the taped breakout location 260 (see FIGS. 10-11 ). The enclosure (e.g., an overmold layer) 300 seals and protects the underlying components of the breakout assembly 200 . The tether 240 extends outwardly from the body 310 of the enclosure 300 to tether connectors (not shown) spaced from the enclosure body 310 .
[0046] Referring now to FIG. 12 , the enclosure 300 is installed over the breakout assembly 200 by securing the ends 302 , 304 of the enclosure body 310 to the distribution cable 220 . The ends 302 , 304 of the enclosure body 310 also can be secured to the tether 240 . FIG. 12 illustrates a flowchart depicting an installation process 1200 for installing the enclosure body 310 . The installation process 1200 begins at start module 1202 and proceeds to a first prepare operation 1204 .
[0047] The first prepare operation 1204 provides protection for the exposed buffer tubes 222 and coupled optical fibers 224 dc , 224 t against the heat and other stresses associated with overmolding an enclosure. For example, heat resistant tape 208 ( FIG. 13 ) can be wrapped around the buffer tubes 222 and coupled optical fibers 224 dc , 224 t . As shown in FIG. 13 , the heat resistant tape 208 is wrapped from the distribution cable jacket 230 adjacent the first end 352 of the stripped region 350 ( FIG. 5 ), around the breakout assembly 200 ( FIG. 5 ), past the second end 354 of the stripped region 350 , and over the distribution cable jacket 230 and tether jacket 250 at the second end 354 of the stripped region 350 ( FIG. 5 ).
[0048] A second prepare operation 1206 provides regions of adhesion on the distribution cable 220 to which the enclosure body 310 can be secured. The process for providing the adhesion regions will be discussed herein with reference to FIGS. 14-17 . In general, the adhesion regions 322 , 324 are provided on the outer jacket 230 of the distribution cable 220 . For example, as shown in FIG. 13 , a first adhesion region 322 is typically provided on the distribution cable 220 adjacent the first end 352 of the stripped region 350 and a second adhesion region 324 is provided adjacent the second end 354 of the stripped region 350 .
[0049] The adhesion regions 322 , 324 have lengths L 1 , L 2 , respectively, that extend longitudinally along the distribution cable 220 ( FIG. 13 ). In the example shown in FIG. 13 , the first adhesion region 322 extends from a first end of the heat resistant tape 208 in a first direction extending generally away from the breakout location 206 ( FIG. 5 ). The second adhesion region 324 extends from a second, opposite end of the tape 208 in a second, opposite direction generally away from the breakout location 206 . Typically, the lengths L 1 , L 2 of the adhesion regions 322 , 324 extend about 1-4 inches, inclusive. Preferably, the lengths L 1 , L 2 each extend about 2-3 inches.
[0050] An optional third prepare operation 1208 provides a region of adhesion on the tether 240 to which the enclosure body 310 also can be secured. For example, a third adhesion region 326 having a third length L 3 is shown in FIG. 13 extending over the outer jacket 250 of the tether 240 . In general, the third prepare operation 1208 is substantially similar to the second prepare operation 1206 . The third adhesion region 326 , therefore, is generally similar to the adhesion regions 322 , 324 provided on the distribution cable 220 . Typically, the length L 3 of the third adhesion region 326 is substantially the same as the lengths L 1 , L 2 of the adhesion regions 322 , 324 , respectively, of the distribution cable 220 .
[0051] An overmold operation 1210 installs the enclosure body 310 over the breakout location 206 ( FIG. 5 ) of the distribution cable 220 . In general, the enclosure 310 encloses the distribution cable 220 and the breakout assembly 200 . Typically, the enclosure 310 also encloses a portion of the tether 240 . In the example shown, the first end 302 of the enclosure body 310 is formed around the first adhesion region 352 and the second end 304 of the enclosure body 310 is formed around the second adhesion region 354 and the third adhesion region 356 . In some embodiments, the enclosure body 310 also can extend past the adhesion regions 352 , 354 , 356 . The overmold operation 1210 is described in more detail with respect to FIG. 16 .
[0052] FIG. 14 illustrates a flowchart depicting an example treatment process 1400 for providing enhanced adhesion between two materials, such as two polymeric materials. For example, the treatment process 1400 increases the adhesion between a polyurethane material and a polyethylene material. The treatment process 1400 can be used to prepare the outer jacket 230 of the distribution cable 220 to enable the enclosure body 310 to couple more securely to the outer jacket 230 . For example, in preliminary testing, the treatment process 1400 has increased the pull out strength of a polyethylene cable from a polyurethane enclosure by 300%-400%. Optionally, the outer jacket 250 of the tether 240 can be prepared using substantially the same process.
[0053] The treatment process 1400 begins at start module 1402 and proceeds to a sand operation 1404 . The sand operation 1404 roughens the circumferential surface of the outer jacket 230 at the first and second adhesion regions 322 , 324 . Generally, the outer jacket 230 along the regions 322 , 324 is sanded with a grit ranging from about 40 to about 180, and more preferably ranging from about 60 to about 120. Preferably, the gritted material (e.g., sandpaper) is rubbed laterally across the cable 220 . However, the cable 220 alternatively could be sanded along the longitudinal length of the cable 220 .
[0054] A clean operation 1406 applies a cleaning agent to the sanded areas and then removes the excess cleaning agent. For example, alcohol (e.g., isopropyl alcohol) can be applied to the roughened surfaces of the outer jacket 230 . The excess alcohol can be wiped away with a clean cloth. The clean operation 1406 can be performed anytime after the sand operation 1404 .
[0055] An etch operation 1408 is performed after the clean operation 1404 . In general, the etch operation 1408 is performed while the outer jacket 230 is still clean. It is believed that dirt or other contaminants can shield the outer jacket 230 from the full effects of the etching. Typically, the etch operation 1408 is performed within four minutes of the clean operation 1406 to inhibit contamination of the jacket 230 (e.g., from the environment). Preferably, the etch operation 1408 is performed within two minutes when not in a clean room environment.
[0056] The etch operation 1408 increases the surface area of the adhesion regions 322 , 324 by providing disruptions on the outer jacket 230 along the cleaned and sanded regions 322 , 324 . Typically, the etch operation 1408 is performed using a plasma etcher 400 ( FIG. 15 ). One example of a suitable plasma etcher is the Flume™ system from Plasmatreat North America, Inc.
[0057] The plasma etcher 400 has at least a first head 402 ( FIG. 15 ). Each head 402 is configured to emit a beam of plasma. In some embodiments, the beam of plasma is emitted in a ringed configuration. In other embodiments, a beam emitting nozzle (not shown) on the head 402 is configured to rotate in a circular pattern. In still other embodiments, however, the beam of plasma can be emitted from the head 402 in any desired configuration.
[0058] The cable 220 is positioned adjacent the first head 402 so that the plasma beam is directed at one of the adhesion regions 322 , 324 . Typically, the adhesion regions 322 , 324 extend over a length that is greater than the diameter/width of the plasma beam. For example, the length of the adhesion region 322 is preferably about three inches and the diameter/width of the plasma beam is typically about one inch.
[0059] To etch the entire length of each adhesion region 322 , 324 , therefore, the cable 220 is moved back and forth along the length of each adhesion region 322 , 324 along a longitudinal axis M of the cable 220 . In some embodiments, to etch the entire circumference of each adhesion region 322 , 324 , the cable 220 is rotated at least partially about the longitudinal axis M. When one side of the cable 220 has been etched, the cable 220 can be flipped about 180° so that the etcher head 402 faces the opposite side of the cable 220 . The etching operation 1408 can then be repeated for the opposite side.
[0060] In other embodiments, however, the plasma etcher 400 has a first head 402 and a second, opposing head 404 as shown in FIG. 15 . The cable 220 is positioned between the opposing heads 402 , 404 so that the plasma beams emitted from the heads 402 , 404 contact both sides of the cable 220 . If desired, the cable 220 can be moved along the longitudinal axis M as discussed above to increase the surface area with which the etcher 400 interacts. In addition, the cable 220 also can be rotated about the longitudinal axis M to etch the entire circumference of the cable 220 . The treatment process 1400 ends at stop module 1410 .
[0061] FIG. 16 illustrates a flowchart depicting an example overmold process 1600 for overmolding a telecommunications cable. The overmold process 1600 is performed after the etch operation 1408 of the treatment process 1400 . In general, care is taken to avoid contacting the treated (e.g., etched) cables 220 , 240 with human hands. Preferably, the overmold process 1600 is performed within four minutes of the etch operation 1408 to mitigate the chances of contaminating (e.g., touching) the treated cables 220 , 240 . The overmold operation 1410 surrounds the distribution cable 220 at the breakout location 206 ( FIG. 5 ) and the adhesion regions 322 , 324 , 326 of the cable jackets 230 , 250 with an enclosure 300 .
[0062] The overmold process 1600 begins at start module 1602 and proceeds to a mount operation 1604 . In the mount operation 1604 , the treated distribution cable 220 is placed in a mold 370 . In the example shown in FIG. 17 , the distribution cable 220 is placed within a mold 370 formed from a first member 372 and a second member 374 . Other suitable molds 370 can also be used.
[0063] Polymeric material is introduced into the mold in inject operation 1606 . The polymeric material is injected from a source 376 , through a conduit 378 , and into the mold 370 to cover portions of the distribution cable 220 including the treated adhesion regions 322 , 324 . Generally, the enclosure body 310 is formed of a different material than the outer jacket of the distribution cable 220 . Typically, the enclosure body 310 is formed of Polyurethane and the outer jacket of the distribution cable 220 is formed from Polyethylene. In some embodiments, a portion of the tether 240 is placed into the mold 370 with the distribution cable 220 and the polymeric material is injected around the treated region 326 of the tether cable jacket 250 .
[0064] A cure operation 1608 allows the polymeric material to harden. For example, the cure operation 1608 can allow the polymeric material time to cool. A remove operation 1610 removes the distribution cable 220 from the mold 370 . The hardened polymeric material remains secured around the distribution cable 220 to form an enclosure body 310 ( FIG. 18 ). The overmold process 1600 ends at stop module 1612 .
[0065] It is preferred for the enclosure body 310 to be sized with a cross sectional shape sufficient to allow the breakout location 260 to be readily passed through a one and one-half inch inner diameter conduit or a one and one-quarter inch diameter conduit. In certain embodiments, the breakout location 260 has a cross sectional area that can be passed through a one inch inner diameter conduit.
[0066] The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. | A telecommunications cable includes a distribution cable, a tether branching from the distribution cable at a breakout location, and an enclosure that surrounds the breakout location. The enclosure is secured to the distribution cable at first and second adhesion regions. The enclosure can also secure to the tether at a third adhesion region. The adhesion regions are treated by sanding the regions, cleaning the regions, and then plasma-etching the regions immediately before welding/injection molding the enclosure around the breakout location. | 1 |
FIELD OF THE INVENTION
The present invention is directed to a system for monitoring the condition and performance of engine cylinders of an internal combustion engine, especially a diesel engine.
BACKGROUND OF THE INVENTION
With the continuing need for obtaining better performance, fuel economy and polution control of internal combustion engines, systems have been developed which attempt to monitor the condition and the operation of the engine by observing the health and performance of its cylinders. Unfortunately, many of these systems suffer from undesirable drawbacks due to the manner in which they sense and/or analyze the data. For example, some systems attempt to monitor the engine condition by providing a sensor for each engine cylinder, which increases the cost of the system because of the number of sensors employed. Other systems couple the sensors to the engine such that the sensors are exposed to high pressures and temperatures within the cylinders, making the data output unreliable due to sensor failures and also increasing the cost because of the need to replace the damaged sensors. Attempts to avoid sensor failures of this type by installing the sensors in the engine wall have proved difficult to implement.
From a data analysis standpoint, previous approaches do not accommodate the many variables that are introduced into the signal outputs by the placement of the sensors on different cylinders or the different operating modes of the engine. Moreover, conventional approaches lack adequate signal to noise ratios or repeatablility due to the fact that they measure only a small portion of the stress that is generated by the cylinder pressure.
SUMMARY OF THE INVENTION
The present invention overcomes these shortcomings of the prior art by providing a pressure sensor that is mounted external to the cylinder but which is easily fitted to any type of cylinder and has a mounting configuration such that it is capable of monitoring the pressures within two adjacent cylinders. The signal output of the sensor is filtered to remove undesired engine noise and blank out those signals which are unrelated to compression and firing, thereby reducing errors in the signal output.
For this purpose, the present invention employs a ring or annular-shaped sensor mounted on a crab foot which bridges a pair of cylinders and contains a bolt which is stressed by the internal pressures of the cylinders. Since the stressing of the bolt is directly related to the pressures of the cylinders, the ring-shaped sensor produces output signals representative of the pressure variations in the adjacent cylinders that are bridged by the crab foot. The signals that are produced are measured relative to the top dead center of a respective cylinder of interest. After filtering the signals to reduce noise, a successive number of samples related to compression and firing are obtained to provide an adequate number of signals which will average out mechanical and electrical noise. From the successive samples, a straight line approximation of the slope of the cylinder pressure curve, relative to crank angle, is obtained. The derived slope values are compared with upper and lower limits to determine whether or not the pressure within the engine cylinder of interest is acceptable. If the upper limit is exceeded or if the value obtained is less than the lower limit, a fault in the cylinder operation is assumed to have occurred. This fault measurement and analysis procedure is repeated a prescribed number of times and if the problem continues to occur over a predetermined consecutive number of measurements, then a fault indication is generated.
In establishing the upper and lower limits relative to which the signal samples are evaluated, initial operation values are employed during initialization or set up time in order to factor out location variables, sensor calibration inaccuracies and variables introduced by the different operating modes of the engine. These values are referenced via a lookup table under processor control for evaluating the pressure signals. In carrying out the signal analysis procedure, a prescribed time delay is introduced for each change in operation mode in order to allow for the occurrence of noise transients. The various portions of the signal sampling and analysis scenario are fully programmable with respect to the timing sequences employed, number of engine cylinders monitored and the type of stress waves which are to be analyzed, so that the present invention may be applied to a variety of engine designs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial sectional view of the arrangement of a stress wave sensor mounted via a crab foot bridging a pair of engine cylinders;
FIG. 2 is a partial plan view of a portion of an engine showing a plurality of adjacent cylinders and the manner in which the sensors are mounted on adjacent cylinders via the crab foot bolts;
FIG. 3 is a mechanical schematical view of the mounting of a top dead center sensor and a ring gear tooth rotation sensor relative to the engine ring gear;
FIGS. 4A and 4B are a schematic block diagram illustration of the signal processing portions of an engine signal analyzer which is coupled to receive the outputs of the crab foot sensors attached to the engine cylinders shown in FIGS. 1 and 2;
FIG. 5 is a table of compression and firing sample timing values for a sixteen cylinder diesel engine used explaining the operation of the signal analysis components of FIGS. 4A and 4B; and
FIG. 6 shows engine pressure waveforms relative to ring gear rotation, as measured at a crab claw sensor bridging the first and second cylinders of a sixteen cylinder engine, values for which are tabulated in FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1 and 2, there are shown respectively a partial sectional view and plan view of portions of engine cylinders of which a crab foot mounted stress wave sensor may be employed for providing cylinder pressure signals to be analyzed in accordance with the present invention. As shown in FIG. 1, a single crab foot 24 and an associated stress wave sensor 23 are employed for detecting the pressures within adjacent cylinders having compression chambers 11 and 14. For purposes of the present description, it may be assumed that the environment in which the invention is employed is a sixteen cylinder locomotive diesel engine. However, it should be understood that the invention is not limited thereto but is applicable to various types of internal combustion engines. FIG. 1 illustrates the mounting of a transducer 23 for cylinders numbers 1 and 2 of the diesel engine. Cylinder No. 1 has a cylinder head 10-1 which, together with piston 15, defines the volume of compression chamber 14. Rod 16 extends from piston 15 to an output drive coupling. Similarly, for cylinder No. 2, cylinder head 10-2, together with the piston 12, defines the displacement or volume of compression chamber 11, with rod 13 extending from piston 12 to a suitable drive output coupling. A bolt 21 passes through an aperture 17 in the engine case and through apertures in crab foot 24, annular or ring-shaped shaped stress wave sensor 23 and a nut 22. As nut 22 is tightened upon ring-shaped sensor 23, the sensor is secured between the nut and the crab foot and the crab foot 24 frictionally engages the tops of the cylinder heads 10-1 and 10-2. With this arrangement, for changes in pressure within the respective cylinders, a corresponding stress is created in the bolt 21. The stress is detected by sensor 23 which provides analog output signals representative of a composite stress wave from cylnders No. 1 and 2. An adjacent crab foot 25, shown in FIG. 2, but absent a sensor, is also coupled to cylinders 1 and 2. Additional crab feet 26-29 are coupled between cylinders No. 2 and 3 and cylinders No. 3 and 4, as shown in FIG. 2. No sensor is provided in the crab foot arrangement between cylinders No. 2 and 3 but rather between cylinders No. 3 and 4 in a configuration similar to that for cylinders No. 1 and 2, as shown in FIG. 2. Namely, a ring sensor 31 is held in place by a nut which threadingly engages bolt 32 which forms part of the crab foot. Thus, for a sixteen cylinder configuration of the diesel engine environment of the present example, there will be a total of eight stress wave sensors mounted between respective cylinders 1-2, 3-4, 5-6, 7- 8, 9-10, 11-12, 13-14 and 15-16.
During a single cycle of rotation of the ring gear for the diesel engine, the pressure wave in an individual cylinder, such as cylinder No. 1, varies as shown in curve A of FIG. 6. As shown therein, the cylinder pressure has a peak in the neighborhood of the top dead center location of the piston for that cylinder. For a sensor positioned to measure the composite pressure for a pair of adjacent cylinders, for example, cylinders No. 1 and 2 as shown in FIGS. 1 and 2, there will be obtained a resultant curve B shown in FIG. 6 which contains a pair of significant peaks in the neighborhood of top dead center positions for the pistons and cylinders No. 1 and 2 as shown. Namely, the major contribution of the pressure wave is obtained from the adjacent cylinders being measured with the effects of the mechnical mounting arrangements and characteristics of the other cylinders, while contributing to the resultant overall curve, having only minor significance. This is best illustrated in FIG. 6 in considering the crank angle displacement relative to the top dead centers of cylinders No. 1 and 2. Namely, for a 90° displacement from the top dead center position to cylinder piston No. 1 to the top dead center position of cylinder piston No. 3, there is a substantial decrease in the pressure detected at cylinder No. 1 and for a 180° shift (TDC of cylinder No. 4) from the top dead center position of cylinder No. 1, the sensor output is substantially negligible.
As will be explained below in conjunction with the description of the signal measuring components shown in FIGS. 4A and 4B, the output of the stress wave sensor for a pair of adjacent cylinders, such as cylinders No. 1 and 2 illustrated as curve B in FIG. 6, is filtered to obtain the resultant waveform shown as curve C in FIG. 6.
For obtaining proper timing of the operation of the engine relative to the ring gear rotation, a top dead center detection target 42 is affixed to ring gear 41 and a magnetic pickup sensor 44 is positioned at a prescribed rotational location relative to ring gear 41 to produce an output for the top dead center position of a selected cylinder of interest, here cylinder No. 1. Thus, output line 46 from top dead center sensor 44 produces a top dead center representative signal as target 42 passes by the magnetic pickup 44. Similarly, a timing signal generator consisting of a magnetic ring gear tooth detector 43 is positioned adjacent the teeth of the ring gear 41 so that as each tooth passes by the magnetic pickup, there is a variation in the magnitude of the signal on line 45. As is conventional in the art, this signal typically has a pair of opposite polarity portions succeeding one another as a ring gear tooth approaches and passes by the magnetic pickup.
Before describing, in detail, the signal processing scheme illustrated in FIGS. 4A and 4B that may be employed in accordance with the present invention, it should be observed that the present invention resides primarily in a novel structural combination of conventional signal processing circuits and not in the particular detailed configurations thereof. Accordingly, the structure, control and arrangement of these conventional circuits have been illustrated in the drawings by readily understandable block representations and schematic diagrams, which show only those specific details that are pertinent to the present invention, in order not to obscure the disclosure with structual details which will readily apparent to those skilled in the art having the benefit of the description herein. In addition, various portions of an electronic data processing system have been appropriately consolidated and simplified in order to emphasize those portions that are most pertinent to the present invention. Thus, the block diagram illustrations of FIGS. 4A and 4B do not necessarily represent the mechanical structural arrangement of the exemplary system, but are primarily intended to illustrate the major structural components of the system in a convenient functional grouping, whereby the present invention may be more readily understood.
Referring now to FIGS. 4A and 4B, the electronic signal processing portion of the present invention is illustrated as processor-controlled system. The processor 100 proper communicates with the other components of the system over a communication bus 65. Communication bus 65 is coupled through a bus interface circuit 64 to the various signal timing and data input circuits to be described below. The processor 100 itself is formed of conventional components including a read only memory portion, a random access memory portion and a central processing unit intercoupled with one another to carry out the signal processing and control functions of the invention to be detailed below. As specific details of such circuitry is not necessary for an understanding of the present invention they will not be described here. Rather, the manner in which the processor interacts with the other portions of the system and the signal input/output and control functions will be described. The processor may also include a separate mathematical or algorithm processor for carrying out calculations for obtaining a best fit line approximation of the data points with pressure curve characteristics shown in FIG. 6. It may further include an associated bubble memory to provide non-volatile storage for fault records generated in accordance with the operational scenario to be described below. An indication of any fault may be displayed on a display panel 101 and signals representative thereof may be available at a down load port 102. For data communication purposes standard synchronous data link communication signalling formats such as an RS 232 data format may be employed.
Referring to FIG. 4A, the signal output lines from the various sensors 23 that are coupled to respective pairs of the cylinder heads correspond to input signal lines 51 that are coupled to multiplexer 52. In accordance with a control signal supplied over control line 53 from processor 100, multiplexer 52 selects one of the pairs of cylinders of interest (1/2, 3/4, . . . 15/16) and couples a respective one of input lines 51 to the output of the multiplexer for application to a linear phase low pass filter 54. Filter 54 is comprised of a linear phase (Bessel) low pass filter (having an inherent absolute phase delay) and filters the sensor waveform coupled through multiplexer 52 at approximately 100 Hz. Thus, if multiplexer 52 is controlled to select the input signal line associated with cylinders 1 and 2, its output will represent the sensor signal associated with those cylinders as illustrated in curve B of FIG. 6. Low pass linear phase filter 54 then filters the signal and supplies an output corresponding to the signal shown as waveform C in FIG. 6. This signal is applied to an analog to digital converter 55. Analog to digital converter 55 is enabled by a control signal on line 56 from the processor. When enabled, A/D converter 55 converts the value of the filtered waveform at the sample time of interest to a quantized digital signal and supplies the quantized data over line 57 for temporary storage in an output buffer 61. Buffer 61 is controlled by a control line 62 from the processor. Control line 62 is employed to read out data into the processor for storage in memory during data write operations. The outputs of the buffer 61 are coupled over lines 63 to the data portion of the communication link to the processor.
Timing signals representative of the rotational position of the ring gear which defines the operational states of the various cylinders of the engine are provided over lines 45 and 46 as discussed above in conjunction with FIG. 3. Line 46 is coupled to the output of the top dead center sensor 44 through an amplifier shaper 91 to a top dead center delay circuit 92. Top dead center delay circuit 92 provides a delay equal to the inherent phase delay of low pass linear phase filter 54 in order to assure proper synchronization of the signals that are sampled and written into processor memory. The output of delay circuit 92 is coupled over signal lines 71 as a delayed top dead center signal to a programmable timer counter 75. Line 71 is used to enable counter 75 so that it may begin counting pulse signals provided over line 45 from ring gear 41 to sensor 43, the signals being shaped by an amplifier shaper 73 and a frequency doubler 74. Frequency doubler 74 provides a timing pulse for each leading and trailing edge of the ring gear pulse during rotation of the ring gear 41 past detector 43. Counter 75 may comprise a programmable down counter which is loaded with an initial reference value from the processor supplied over link 76. When enabled by a delayed top dead center signal on line 71, programmable timer 75 begins counting down from the value supplied over line 76 in response to timing pulses or gear tooth pulses supplied from the frequency doubler 74. When programmable timer 75 counts down to zero, it generates an output corresponding to an interrupt request over line 81. Line 81 is coupled to an interrupt controller 88, the output of which is coupled over line 89 to the processor communication bus via the bus interface circuit 64. The interrupt request on line 81 corresponds to an analog-to-digital converter interrupt request which causes the processor to enable analog-to-digital converter 55 via link 56, so that the value of the sensor waveform at the time of the interrupt will be sampled for storage in processor memory.
Programmable timer 75 is employed for governing the initiation and successive sampling of portions of the signal waveform C shown in FIG. 6 at a prescribed compression portion of the cylinder output characteristic just prior to the top dead center peak. As will be explained below, for a successive number of gear tooth rotation or timing intervals, samples of the composite stress wave form are produced and loaded into the processor, from which a best fit line approximation of the slope of this portion of the wave form may be obtained for diagnostic test purposes.
The initiation and the duration of a firing sample period, which follows the compression sample period, delineated by sample period E associated with composite wave form C shown in FIG. 6, is carried out by a programmable divider 83 and an associated firing sample timer 86. Programmable divider 83 is coupled to receive a system clock signal coupled over line 82 and divides system clock pulses by an appropriate divisor to produce output pulses at a selected timing rate corresponding to the desired sampling frequency. For purposes of the present description, this may be assumed to be on the order of 0.2 ms. Thus, 0.2 ms clock pulses will be produced at the output of divider 83. As mentioned above, divider 83 is programmable via link 84, so that the circuitry is readily adaptable to various types of engines. The clock pulses supplied from divider 83 are coupled to a firing sample timer 86 which counts down a preloaded count supplied over line 85 from the processor to a prescribed value (e.g. zero) and then generates an output corresponding to an interrupt request over link 87.
Link 87, like link 81, is coupled to interrupt controller 88, which again instructs the processor to enable analog-to-digital converter 55 via control line 56. Thus, during the firing sample period E, associated with curve C as shown in FIG. 6 referenced above, the combined operation of divider 83 and firing sample timer 86 will cause the processor to sequentially enable analog-to-digital converter 55 for successive sampling (at a much higher rate than during the compression sample period) of a portion of the signal waveform just prior to its peak, and just subsequent to the top dead center position on the waveform. As noted above, the compression sample period is just prior to the top dead center portion of the waveform for the cylinder of interest whereas the firing sample period is just subsequent to the top dead center portion for the cylinder. Interrupt controller 88 is coupled to an additional pair of lines 98 and 93 which are associated with a top dead center error detecting circuit shown in the upper portion of FIG. 4B.
More particularly, as pointed out previously, the top dead center sensor signal coupled over line 46 is supplied to an amplifier shaper 91. The output of the amplifier shaper 91, in addition to being coupled to the delay circuit 92, it is coupled over line 93 to a programmable counter 94 and to one input of AND gate 97. Line 93 is employed to enable interrupt controller 88 in response to the top dead center signal over line 46. Line 98, on the other hand, is employed to disable the interrupt controller to prevent the processor from responding to interrupts that are generated in response to an erroneously produced top dead center signal. More specifically, for each respective engine cylinder, the top dead center position of that cylinder may be defined in accordance with the rotation of the ring gear, by counting the number of teeth of the ring gear passing by the top dead center position sensor relative to some reference point. Using the top dead center position of cylinder No. 1 as a zero reference point, then for every other cylinder, there will be some number of gear teeth that will rotate relative to the pick up which will delineate the position at which the piston in the particular cylinder of interest was reached top dead center. Referring to the table shown in FIG. 5, for a ring gear having 264 gear teeth, for a firing sequence 1-3-4-2, as shown, and assigning top dead center as a 0 count for cylinder No. 1, then cylinder No. 3, the next cylinder to fire, which is displaced 90° from the standpoint of the rotation of the ring gear relative to the position of top dead center of cylinder No. 1, will provide a gear tooth count of 66 or one-fourth of the 264 gear teeth of the ring gear. Similarly, proceeding around the ring gear, cylinder No. 4, which fires next, has a reference count of 132, whereas cylinder No. 3, the last of the quartet of the group of four to fire with an exact 90° phase displacement relative to cylinder No. 1, has a count of 198 as its reference point at which a top dead center signal is produced. These respective values, for each cylinder of interest, are selectively supplied over link 95 from the processor and loaded into programmable downcounter 94. When a top dead center signal is produced from sensor 46, counter 94 begins counting down from the value initially loaded therein. If, during the process of counting down, another signal is produced over link 46, AND gate 97 is enabled, thereby suppling a signal over line 98 to disable interrupt controller 88. Namely, there may be some circumstance where mechanical or electrical noise will produce a ghost top dead center signal is correct so that it aborts the interrupt routine. Counter 94 and associated AND gates 97 provide this safeguard.
OPERATION
The description of the operation of the system of the present invention will be divided into two segments. The first segment will treat the manner in which electronic signal processing circuitry described above operates to successively sample portions of the composite stress waveform of the respective cylinder pairs and load the sampled data into the processor. The second portion of the description will treat the manner in which the processor operates on the signal samples to determine whether or not the respective cylinders are operating properly or whether a fault condition has occurred.
SIGNAL SAMPLING AND DATA INPUT COMPRESSION DATA SAMPLING
As described above, persuant to the present invention, the health and performance of the engine is monitored by observing selected portions of the composite stress waveform between a pair of respective cylinders, with a composite stress wave being analyzed relative to each of the cylinders of interest, so as to focus upon a compression sample period and a firing sample period for those particular cylinders. Referring again to FIG. 6, the composite signal waveform shown in curves B and C may be analyzed with respect to cylinders No. 1 and 2. In the region of the top dead center position of cylinder No. 1, the waveform form is analyzed to determine a best fit approximation of the slope of portions for a compression sample interval and a firing sample interval delineated by intervals D and E. Similarly, although its respective compression sample and firing sample intervals are not delineated in FIG. 6, cylinder No. 2 may be analyzed from the same composite waveform by evaluating the slope of the composite curve within the region of the top dead center position of cylinder No. 2, which is separated by 90° from the top dead center position of cylinder No. 1, so that a determination of the characteristics of cylinder No. 2 may be obtained from the same waveform that produces characteristics for cylinder No. 1.
Referring now to FIGS. 4A, 4B, 5 and 6, it will be assumed that the signal analysis program stored in ROM within the processor 100 analyzes the cylinders in succession, namely beginning with cylinder No. 1 and ending with cylinder No. 16, for the sixteen cylinder engine of interest. In this regard, the characteristics shown in the table and FIG. 5 and the stress waveform shown in FIG. 6 corresponds to an EMD 645 E3 engine. Considering cylinder No. 1 as the first cylinder of interest, processor 100 supplies a control signal over line 53, so that the composite waveform B(FIG. 6) supplied from sensor 23 is coupled over the selected one of lines 51 through multiplexer 52 and filtered in low pass filter 54 to produce the filtered stresswave C shown in FIG. 6. By way of line 76, a gear tooth reference numer (247 as shown in the table in FIG. 5) is loaded into programmable down counter or compression sample timer 75 from the processor. When a top dead center signal is produced from sensor 44, it is delayed by delay circuit 92 and coupled over line 71, to enable down counter 75. Once enabled, down counter 75 begins counting ring gear tooth pulses supplied by frequency doubler 74. Assuming that there are no ghost or erroneous TDC signals produced, then counter 75 will count down to 0 and produce an interrupt request over line 81. Interrupt controller 88 supplies this interrupt request over line 89 to the processor which, in turn, generates an enable signal over line 56, so that analog-to-digital converter 55 may sample the value of the composite waveform at that point. Namely, from the point at which a top dead center signal is produced from sensor 44 to the point of which A/D converter 55 begins sampling the composite filtered stress waveform C for a cylinder No. 1, 247 gear teeth will pass by the top dead center sensor 44 and, likewise, ring gear tooth sensor 43. For a 264 gear tooth arrangement, the sampling interval begins 17 gear teeth prior to the location of top dead center.
Analog-to-digital converter 55 samples the analog value of the filtered composite waveform and couples the resulting quantized digital code for storage into an output buffer 61. When the processor is ready to load the contents of the buffer 61 into internal memory, it supplies a transfer control signal over line 62, so that the sampled data stored in buffer 61 may be coupled over link 63 to the random access memory within the processor.
At the same time the processor also supplies a new sample value over line 76, for example the number two or the number four, depending upon the output of frequency doubler 74 to down counter 75. Where two pulses are produced for every rotation of a single gear tooth past the gear teeth sensor, processor 100 may supply the number four over link 76 to be loaded into counter 75. Counter 75 then down counts four pulses or two gear teeth positions before generating another interrupt request over line 81. This results in a new sampling of the output of sensor 23 for cylinders No. 1 and 2; namely A/D converter 55 samples the filtered composite waveform C after a rotation of two gear teeth past sensor 43.
Within an internal soft-counter, processor 100 keeps track of the number of samples being successively obtained from the sensor output. For example, an internal soft-counter may be initially loaded with the value of eight, down count to zero and then produce a sample disable request for the compression sample interval. This would correspond to a rotation of 14 gear teeth past the ring gear rooth sensor 43 subsequent to the position at which compression sample timer 75 first caused an interrupt request to be generated, namely from the value 247 shown in the table in FIG. 5. At the end of the sampling interval, considering that eight successive samples of the filtered compression curve have been digitized and stored in memory, processor 100 begins a best fit straight line approximation for the composite compression curve relative to cylinder No. 1 in the region D of the sample period shown in FIG. 6. It also determines the slope (m) of this line and compares the slope value with respective limits for determining a fault condition, as will be delineated more specifically below.
FIRING DATA SAMPLING
After a prescribed delay subsequent to the loading of the last sample of the filtered composite stress waveform at the end of the compression sample period, the processor enables counter 86 and loads it with a value corresponding to the number of samples to be taken for the firing sample interval. Again, assuming that eight samples will be taken, just as eight samples were derived for the compression sample period, firing sample timer 86 begins counting down from its initial value of eight to zero. The 0.2 ms clock pulses that are coupled to the firing sample timer 86 are also coupled to line 87 as interrupt requests, in response to which the processor successively enables the A/D converter via line 56, to load successive samples from the composite filter stress waveform into internal memory. This is carried out in the same manner described above in connection with the compression sample period, except that the times of occurrence of the successive samplings are carried out independently of the rotation of the gear teeth; namely, they are associated with a prescribed internal system clock having the exemplary repetition period 0.2 ms. Thus, for the firing sample period E shown in FIG. 6, samples are extracted at a higher frequency then during the compression sample period D.
For the second and subsequent cylinders, different ring gear teeth numbers are loaded into the programmable compression sample timer 75, as illustrated in FIG. 6, so that the proper locations on the filtered composite stress waveform relative to the cylinders of interest will be sampled and loaded into the processor memory.
SIGNAL ANALYSIS ALGORITHM
Once a set of data samples, for each respective compression sample period and the firing sample period have been loaded into processor memory, a signal analysis algorithm for the cylinder of interest is carried out. The signal analysis algorithm is a best-fit-line algorithm to determine the slope of the straight line approximation over the sample period of interest. Algorithms for carrying out straight line approximations and best-line-fits to produce values indicative of slope are well known and will not be described here. Suffice is to say that the algorithm processing portion of the processor has been programmed to carry out such a slope determination. Once a slope value (m) has been obtained, each slope value is normalized by adding an offset to the slope value from the best-fit-line approximation.
During a selected time within the operation of the system, an initial slope value for each cylinder is derived from this operation and loaded into a separate portion of memory to be accessed during subsequent signal processing. This is normally carried out during download/upload processing. More specifically, over a series of successive engine cycles, a plurality of slope values are extracted and averaged, to produce an average initial value which is stored in the non-volatile memory, namely the bubble memory referenced previously. Thus, an initial value is stored for each of the sixteen cylinders of the engine of interest and such initial values are produced for each engine operating mode. These initial values are stored as a series of lookup tables which will be accessed for subsequent diagnostic testing in accordance with the particular engine operating mode.
Now, during performance analysis, each time that the samples are stored and slope values are determined therefrom, the initial value slope stored in the lookup table is subtracted from the sum of the calculated slope and the offset value referenced previously. This remainder is compared to prescribed high and low limits which have been stored in the non-volatile memory. If the remainder value exceeds one of these limits, namely, if the remainder is greater than the upper limit or less than the lower limit, a fault condition is identified. Over a prescribed number of engine revolutions, this process is continued for each respective cylinder to determine if the fault condition is a continuous one or simply erratic. Namely, a soft accumulator is employed to count the number of detected faults, namely the number of instances in which the remainder value exceeds the upper limit or is less than lower limit. If a prescribed consecutive number of faults is accumulated, the processor generates an output signal to the display panel 101 which energizes a failure lamp associated with that respective cylinder and a record of the fault is stored in memory. Associated with this stored record, another software accumulator may be employed to provide the cumulative time during which a given fault condition exists. For this purpose, the software accumulator may be successively enabled to count system clock pulses in response to a fault condition and then disabled when the fault condition disappears. As a result, the soft counter may be accessed to determine the cumulative time for which a given fault condition exists. The above process is carried out for both the compression sample period and the firing sample period, so that a determination of the condition and performance of the engine may be derived by analyzing a composite stress wave indicative of the pressure conditions within respective pairs of cylinders. By analyzing the composite stress wave from the standpoint of a compression sample interval and a firing sample interval, and comparing the resultant slopes with stored lookup tables associated with the operating modes of the engine, an accurate determination of the operational condition and performance may be obtained.
While we have shown and described one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to a person skilled in the art, and we therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are obvious to one of ordinary skill in the art. | A system for monitoring the performance of an internal combustion engine includes a pressure sensor that has a mounting configuration external to the cylinders such that it is capable of monitoring the pressures within two adjacent cylinders. The signal output of the sensor is filtered to remove undesired engine noise and blank out those signals which are unrelated to compression and firing, thereby reducing errors in the signal output. After filtering the signals to reduce noise, a successive number of samples related to compression and firing are obtained to provide an adequate number of signals which will average out mechanical and electrical noise. From the successive samples, a straight line approximation of the slope of the cylinder pressure curve, relative to crank angle, is obtained. The derived slope values are compared with upper and lower limits to determine whether or not the pressure within the engine cylinder of interest is acceptable. If the upper limit is exceeded or if the value obtained is less than the lower limit a fault in the cylinder operation is assumed to have occurred. This fault measurement and analysis procedure is repeated a prescribed number of times and if the problem continues to occur over a predetermined consecutive number of measurements, then a fault indication is generated. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an accumulating device for weft yarn feeders to textile machines, of the type comprising a fixed winding drum receiving windings of weft yarns, whose perpheral skirt is interrupted by openings housing so-called fingers or columns, essentially positioned parallel to the drum axis and actuated to swing in order to partially and variably project from said openings and cause said windings to advance on the drum keeping them spaced between each other. The columns, in sequence, radially move and longitudinally swing with respect to the drum due to the fact that they are connected to the feeder motor shaft through a series of coupling means.
2. Description of the Prior Art
As it is known, modern looms ensure constant operating cycles and regular sequence of the different manufacturing steps for every type of yarn. For these reasons the socalled shuttleless looms must be provided with weft feeders, in which the yarn is taken from a reel, is laid down in subsequent and parallel windings on a fixed drum and finally is taken from the latter in an axial direction to be fed to the loom, always ensuring, besides speed, also a constant tension to avoid sudden jerks which would cause process interruptions.
It is therefore necessary, for a regular manufacturing cycle, to always ensure a constant reserve of yarn on the drum.
Moreover it is sometimes necessary, for particular yarns, to warrant that said reserve be formed on the drum also by keeping a predetermined distance or step between each winding and the following one.
In order to comply with said requirement, various solutions have been proposed up to now. Among the most significant solutions we can mention the one of using so-called columns which are mounted in a non-rotary way within longitudinal grooves of the drum and are connected to the motor shaft of the feeder through a bearing and a rotary bush eccentric and sloping with respect to the shaft axis. When the latter rotates, the bush eccentricity and inclination cause on each column respectively a radial upward and downward movement and a longitudinal oscillation which, when combined, allow the column to lift the yarn windings from the drum surace, to advance them of one step and to lay them down again onto the drum surface. Said movement is performed in sequence by all columns, circularly to the drum, and the advancing step depends, eccentricity being equal, on the bush inclination with respect to the shaft.
This solution, though being valid, has the limitation of offering only a single value of the bush inclination and therefore a single value of the step between windings, which can be modified only by replacing the columns-bearingeccentric bush assembly with another one having an eccentric bush with a different inclination. It must be further notified that said inclination must be congruous with the direction of rotation of the motor shaft and when the latter changes it is practically necessary to replace the assembly.
Only said last replacement has been eliminated in the known technique (European patent application No. 0164033 published Dec. 11, 1985) by means of a bush in two pieces, which can be positioned at 180° to one another in order to vary the direction of inclination according to the direction of rotation of motor shaft, on its turn depending on the yarn twisting, S or Z.
Another type of solution (European Patent application No. 0131313 published Jan. 16, 1985) consists in taking advantage of the filling of an elastic hollow body inside the drum in order to always ensure the progress of the windings as a consequence of the variations in elasticity of said hollow body. However said solution has the drawback of not ensuring a wide range of configurations of the elastic body and therefore it is not suitable for all corresponding types of yarns.
OBJECTS OF THE INVENTION
The objects of the invention are to eliminate the aforementioned drawbacks of the presently used device, by providing an accumulating device for weft yarn feeders to textile machines, capable of advancing the weft yarn windings on the winding drum, keeping them spaced between each other of a predetermined step, and which allows to perform a modification of the step between the windings and/or an adjustement of the direction of rotation in a quick and precise way, without disassembling the whole feeder. Said device also ensures a uniform progress of the windings without discontinuity.
SUMMARY OF THE INVENTION
Said objects and further ones, which will better appear in the following specification, are achieved, according to this invention, by means of an accumulating device for weft yarn feeders to textile machines, of the type comprising a fixed drum on the external surface of which windings of weft yarn are positioned by positioning means rotated by a motor shaft, said drum having a series of longitudinal openings where fingers or columns fixed on a non rotating circular support are housed, said support being on its turn assembled, through a bearing, on an eccentric bush rotating with the motor shaft, characterized in that said eccentric bush is mounted on a floating joint: in that said joint and the bush are both rotationally connected to the motor shaft and in that control means are provided to vary and stop at will the inclination of the bush axis with respect to the motor axis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a drum for a weft yarn feeder according to the invention.
FIG. 2 is a schematic axial section of the drum of figure 1.
FIG. 3 shows a longitudinal section of the device according to the invention: and
FIG. 4 is a schematic cross section illustrating the possibilities of adjusting a column.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings, an accumulating device for a weft yarn feeder essentially comprises a drum 1 mounted in a fixed overhanging way on a support (not illustrated), said drum 1 having a slightly cone-shaped side surface on which windings of yarn are placed by means of a known rotary positioning device schematically indicated by reference 2 in FIG. 1. A sensor device 3 detects whether windings are present or not in a certain section of the surface of drum 1 and, on the basis of that, it does or does not actuate feeding of other windings to the drum. The free end of the yarn 4 laying in winding on the drum is drawn as indicated by arrow 5' to be fed to a shuttleless loom, according to procedures well known to those skilled in this art.
The skirt surface of drum 1 is provided with a series of longitudinal openings 5, in each one of which one finger or "column" 6 moves, said column being positioned approximately parallel to the drum axis but variably movable and oscillating, within the opening, with respect to the skirt surface of the drum, in such a way to carry out an advancement of windings from their initial position, on the left of FIG. 1, towards the free end of the drum 1, always maintaining a predetermined step between the windings, and moreover taking into consideration the windings laying direction on the drum 1, which in turn depends on the treated yarn twisting.
As shown in FIG. 2, each column 6 is supported by a support 7 radial with respect to the drum, all supports 7 being in turn connected to a ring support 8 which is mounted in a non rotary way on a bearing 9. This bearing houses a bush 10 assembled on an extension of the motor shaft 11 actuating the yarn positioning device.
According to the known technique, said movements of columns 6 are obtained by using a bush 10 which is at the same time eccentric and skew, namely mounted on shaft 11 in a way as to form a preset angle with the shaft axis.
In this way, eccentricity causes a radial displacement of each column 6 which cyclically projects over the drum skirt surface and lowers below the same. As it is obvious, when the column 6 projects over the skirt surface of drum 1, it collects the yarn windings 4 aligned on it and lifts them from the drum surface. In this condition, the column performs an oscillatory movement in an essentially longitudinal direction, which causes a longitudinal displacement of all the windings resting on it before said column lowers below the skirt surface of drum. The operation is performed in sequence by all columns, following the movement of the motor shaft 11 and therefore of the yarn positioning device.
Still according to the know technique, in case one wants to vary the step between said windings, it is necessary to remove the whole assembly comprising columns 6, supports 7, ring support 8, bearing 9 and bush 10, by replacing the same with another assembly having a bush 10 with an axis having a different inclination to the axis of shaft 11. Of course, it is a long-lasting and complex operation, because it requires the complete disassembling of drum 1. The same operation must be usually performed in case the direction of windings laid down by the device 2 has to be reversed to adapt itself to yarns having a different twisting. In this case, too, though it is possible to maintain, if desidered, the present winding step, it is usually necessary to replace the whole assembly because the bush 10 must have the same axis inclination, but in the opposite direction with respect to a neutral position.
The present invention solves the abovementioned problem by positioning between the bush 10 and shaft 11 a joint 12 (FIGS. 3 and 4), preferably a ball joint; by making both said joint 12 and bush 10 rotationally integral to the shaft 11; by adjusting the angular position of bush 10 as well as of bearing 9, support 8, standards 7 and column 6 taking advantage of the joint 12; and by holding said bush 10 in the preset adjustment position. In this way, it is also possible to obtain any desired inclination of the bush 10 with respect to the axis of shaft 11 and therefore any desired advancement step of the windings on the drum 1. It is also possible to perform said adjustments in both directions starting from a neutral position in which the angle formed by the axis of bush 10 with the axis of shaft 11 is zero, as said two axes coincide.
FIG. 3 shows in partial cross section an actual embodiment of the invention. The feeder 12 therein illustrated comprises a feeding device having a duct 13 in which the weft yarn 4 passes. The duct 13 is mounted in a rotary way on a motor shaft 11, which is actuated according to the above described procedures by a motor (not shown). By means of magnets 14, a supporting frame 15 is held overhanging, essentially extending parallel to the shaft 11 and connected to the latter through bearings 16 housed in supports 17, which are connected to each other by means of tension rods 18.
The side wall of drum 1 has slots 5 wherein columns 6 are housed, according to the previously described procedures, and placed on standards 7 which, in the shown example, are positioned at the top end of a ring support 8 mounted on a bearing 9, which is placed at the support bottom end, in such a way that each column 6 is supported by an element having an essentially L-shaped section, ending in correspondence to the bearing 9. The columns 6 are housed in the relevant openings 5 in a non rotary way, but freely floating both radially and longitudinally with respect to the shaft 11 and are therefore kept in said position by means of pivots 20 protruding from support 8 and housing resilient tension rods 22 placed between seats provided in said pivots 20 and seats provided in said tie rods 18 of the frame. In this way, the columns can perform the mentioned oscillation movements but they do not rotate with respect to the drum.
In order to perform said oscillation movements, the inner track of bearing 9 houses an eccentric bush 10 which in turn is mounted on a ball joint 12, fixed for instance by shrinking on the axis 11. The eccentric bush 10, as well, is fixed in order to rotate together with the shaft 11 and for this purpose it is provided with two pivots 23 projecting in a direction parallel to axis 11, between which a third pivot 24 fixed to the shaft is inserted, the play between said two pivots 23 and pivot 24 being such as to allow the necessary inclination movements permitting the desired positioning of bush 10 and that connected thereto (bearing 9, support 8, standards 7, columns 6) with respect to the axis of shaft 11, in order to vary, as before said, the step between the windings advanced on drum 1. In order to obtain said positioning control, the bush 10 is fixed to a cam follower 25 having a surface 26 sloping by an angle alpha with respect to a plane perpendicular to the axis of shaft 11, said surface 26 coinciding with that of a cam 28 placed in a rotary way with respect to the frame 15, being assembled in correspondence of the last bearing 16. In this way, the cam 28 and cam follower normally rotate, during the yarn positioning, together with the bush 10 and shaft 11, being fixed to the latter for example by means of a nut 29 tightened on the threaded end 30 of shaft 11 and acting on a knurled handle 31 directly connected to said cam 28. In case it is wanted to modify the inclination of bush 10 with respect to the axis of shaft 11, it will be sufficient to unscrew the nut 29, thus allowing the cam 28 and handle 31 to rotate with respect to the axis of shaft 11. Under these conditions, the motor shaft 11 is manually held, for instance through the yarn positioning device, and the handle 31 is rotated until it reaches a desired adjustment, in one direction or in the other one with respect to a zero position (coincidence of the axes of bush 10 and shaft 11), according to the direction of rotation of the motor shaft 11. This adjustment could be performed with the help of notches which will indicate the different chosen positions, possibly even giving the step between the windings. Once the bush inclination has been adjusted on the desired value, it will be sufficient to fix again the whole assembly by screwing the nut 29 to be ready to work again. This adjustment operation is extremely quick and easy and avoids the present need of disassembling the whole unit as well as the need of having in stock a number of bushes with different inclinations. | The invention relates to an accumulating device for weft yarn feeders to textile machines, capable of positioning windings of weft yarns onto a fixed winding drum and of advancing them by keeping the same spaced between each other. It essentially comprises a series of non rotating fingers housed in suitable openings of the drum peripheral skirt, which partially and variably protrude from said skirt as a consequence of the motor shaft movement forming said windings and to which said fingers are coupled through a bearing and a rotary eccentric bush. In order to allow to vary at will the step between said windings, the bush is mounted on said shaft with the interposition of a ball joint so that its inclination with respect to the shaft axis can be adjusted at will. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to a new and improved clothes line device that is easy to move or transport and which can be enclosed for privacy. The device is supported by a pair of hollow, substantially L-shaped base members which can be filled with sand for stabilization. A pair of legs are vertically received within each base member and are attached to three separate tubular sections. The tubular sections form a three-sided upper frame that is attached to a four sided, substantially square lower frame. A plurality of clothes lines are attached in parallel to two opposing sides of the bottom frame. A scroll type spring-loaded privacy screen is received within each tubular section allowing hanging garments to be concealed from public view. The screens may also be secured to the base members preventing the screens from blowing uncontrollably in the wind.
DESCRIPTION OF THE PRIOR ART
Clothes line devices currently in use are openly exposed meaning that undergarments and other potentially embarrassing clothing hanging thereon are in plain view for neighbors or other passers by to see. Accordingly, there is a need for a clothes line device that can be quickly and easily enclosed thereby concealing clothes from public view.
Furthermore, the devices currently in use are generally cumbersome to set up or remove. They are generally supported by a large heavy base member or alternatively they are anchored to the ground. The anchor type devices are susceptible to being knocked down by wind or other external forces.
The devices that are supported by a heavy base member are generally difficult to move and expensive to ship. The present invention can be selectively weighted by filling the base members with sand or a similar material. This feature allows the device to be converted to a lightweight assembly that can be easily and inexpensively shipped or transported. The present invention is designed to provide additional benefits that are not currently present in any of the prior art devices as more fully described below.
U.S. Pat. No. 2,459,110 issued to Midouhas discloses a collapsible clothes line having parallel lines that can be turned to a position parallel with the sun's rays. The clothes line's supporting arms each have a central pivot which facilitates the extension of the arms from the folded vertical position to the horizontal extended position.
U.S. Pat. No. 3,139,190 issued to Shore discloses a collapsible clothes line dryer which has a plurality of arms that swing horizontally about a vertical post. These arms are attached to each other and basically form an X-shaped frame. A pair of hangers are mounted on the arms such that they are substantially parallel. Each hanger has a plurality of slots for receiving clothes lines. A single length of clothes line is used and passed through each slot alternating between each hanger such that the single clothes line forms a plurality of parallel clothes lines. The means for attaching the single line in this manner eliminates the need to tie individual knots at each end of the parallel clothes lines.
U.S. Pat. No. 3,857,493 issued to Bourne relates to a collapsible garment dryer comprising a post with radially extending arms that may be collapsed as desired. The device is stabilized by anchoring the post into the ground.
U.S. Pat. No. 5,280,841 issued to Van Deursen discloses a portable clothes dryer support assembly adapted for mounting on a pole. The device has a set of arms that extend radially from a centrally located collar. The arms extend upward at approximately a 45 degree angle to define a cone-shaped assembly that can easily be collapsed as desired. As indicated above, none of the above described inventions provide a means for concealing clothes that are hanging on a clothes line. Furthermore, none of these inventions provide a base support member that can effectively stabilize a clothes line device while being convertible to a lightweight assembly that can be easily and inexpensively moved, packed and/or shipped.
SUMMARY OF THE INVENTION
The present invention provides a new and improved clothes line assembly that may be selectively weighted when in use and may be enclosed to conceal clothes hanging thereon. It is therefore an object of the invention to provide a new and improved clothes line assembly that can be quickly and easily erected or disassembled.
It is a further object of the present invention to provide a new and improved clothes line assembly that can provide privacy so that clothes hanging thereon are concealed from the general public.
It is yet a further object of the present invention to provide a new and improved clothes line assembly that can be stabilized without the use of a heavy base member or without anchoring to the ground.
It is still a further object of the present invention to provide a new and improved clothes line assembly that can be stabilized with base members that can be quickly, easily and inexpensively removed or shipped.
Other objects, features and advantages of the present invention and its details of construction and arrangement of parts will be seen from the following description of the preferred embodiments when considered with the attached drawings and from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 generally depicts the invention and the accompanying pull down privacy screens.
FIG. 2 shows an L-shaped base member attached to a leg support.
FIG. 3 depicts the device with the screens in the rolled up position.
FIG. 4 depicts a cross-sectional view of the spring loaded screen deployment mechanism used in rolling the privacy screens up or down.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1-4, there is generally shown a mini clothes line assembly with integrated roll-up/roll-down privacy screens. The mini clothes line assembly comprises a pair of hollow substantially L-shaped base members 2. The members are substantially parallel and each 2 has a substantially flat portion 2A. The hollow portion defines a chamber for receiving sand or a similar heavy material. On the top exterior of the substantially flat portion of the L-shaped base members 2 is an integrally molded hook 13 and another aperture 5 which receives a cap 3. The cap may be removed allowing sand to be poured into the chamber to weight and stabilize the device when in use. Furthermore, the sand may be removed as desired allowing the base members to be easily moved or transported.
The hollow base members further comprise an upwardly extending portion 2B. Each of the upwardly extending portions has an aperture 7. A pair of substantially square legs 4 each having a first 4A and a second end 4B and four sides are vertically received within the apertures 7 by inserting the first end 4A therein. Each of the legs 4 has a pair of circular holes 15 at each end. A pair of holes 15 at one end are positioned on different but adjacent sides with a matching, diametrically opposed pair at the other end. The legs 4 are placed in the apertures 7 and aligned such that a hole 15 at each end of one leg is in apostion with a hole at each end of the other leg. Each of the other two pairs of holes are facing in substantially the same direction. The holes 15 at each end lie in substantially the same horizontal plane with respect to the holes at the same end on the other leg.
Three hollow tubular sections 6A, 6B and 6C are attached to each of the legs 4 by inserting an end into each of the holes 15 as shown in FIG. 1. The tubular sections 6A, 6B and 6C form a three sided upper frame with two sides substantially parallel 6A and 6B which are substantially perpendicular to a third side 6C.
A second substantially square bottom frame 10 is attached to the underside of each tubular section 6A, 6B and 6C using conventional attachment means such a screws, bolts or tie-wires. The second bottom frame 10 has two cross support legs 9 extending downwardly at an angle. The cross support legs 9 extend diagonally with respect to the vertical plane formed by a base member 2, its corresponding leg 4 and a parallel tubular section 6A, 6B. The cross support legs 9 attach at an end to the first and second tubular sections 6A, 6B by inserting each into a pair of similarly facing holes on the legs 4 proximal to the first end 4A. A separate horizontal cross support member 11 is received within each of the apositioned holes proximal the first ends 4A of the legs 4.
Received within each tubular section 6A, 6B and 6C is a scroll type screen 17. Each scroll type screen 17 has a stiffener 19 which extends through a longitudinal slot 1 on each of the tubular sections 6A, 6B and 6C. Centrally attached to each stiffener 19 is a handle 8 which can be used to pull the scroll type screen 17 downward. A short bunge cord 16 or similar attachment means may be attached to the handle 8 at one end and to the integrally molded hook 13 on the hollow base member 2 at the other end holding the two side screens in the fully closed position. The screen received within the perpendicular tubular section 6C may be similarly held in place by attaching the cord to the horizontal cross support member 11.
Also contained within each tubular section 6A, 6B and 6C is a stop catch 20 and spring mechanism 21 used in connection with a spring loaded rod. These mechanisms allow the spring loaded screens 17 to function similarly to a household window shade or blind. This mechanism is not shown or described in great detail since these types of screens or shades are generally known in the prior art. A side of the screen may contain any one of an unlimited number of decorative designs or prints 18.
A plurality of clothes lines 12 are attached substantially in parallel to the bottom frame 10 using S-hooks or other convenient attachment means 23. From the above descriptions, it is now apparent that the new invention provides a new and improved mini clothes line which is easier to erect and anchor and which has self-contained privacy screens. Alternatively, the base members may have rollers or other similar transport means attached thereto allowing the device to be easily transported short distances without having to disassemble the device. It is understood that although there has been shown and described the preferred embodiment of the above described invention that modifications may be made to the invention which do not exceed the scope of the appended claims. Accordingly the scope of my invention is to be limited only by the following claims: | The present invention relates to a new and improved clothes line assembly having integrated means for concealing clothing hanging thereon. Privacy screens are received within a top frame section and may be pulled down providing an enclosure. The invention is supported by hollow base members that may be filled with sand or a similar weighted material providing stabilization to the assembly. The weighted material may be removed allowing the assembly to be easily and inexpensively moved or shipped. | 3 |
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA contract, and is subject to the provisions of Public Law 96-517 (35 USC 202) in which the Contractor has elected to retain title.
TECHNICAL FIELD
The invention relates to a vortex generator for fluidics flow control in general, and its application to multiphase flow applications, such as coal slurry feed flow control and/or ash outflow control in a continuous flow ash lockhopper.
BACKGROUND ART
A problem common to most coal gasification and liquefaction processes is the lack of reliable, long-life pressure-letdown valves. Such systems must accommodate gas-solid and solid-liquid-gas mixtures at temperatures up to 900° C. and pressures up to 20 MPa. Commercial development of such advanced fuel processes requires reliable, low-maintenance letdown systems. The standard approach to pressure letdown is to throttle the flow by reducing the flow area in a throated control valve. Unfortunately, high velocities in the valve throat combine with the abrasive solids content of typical coal-derived slurries resulting in excessive valve wear, lack of controllability, and short lifetimes. Attempts to use advanced materials that are more durable under such conditions have met with limited success.
A similar problem is encounted in control of a continuous flow ash lockhopper. The application (NASA NPO-16985-1-CU) titled "Energy Efficient Continuous Flow Ash Lockhopper" filed by Earl R. Collins, Jr., Jerry W. Suitor and David Dubis discloses a system shown here in FIG. 1 that employs a fluidics flow control chamber top allow ash from a lockhopper at the bottom of a coal slurry reactor to pass through under the force of gravity while preventing a flow of reactor gases to pass through with the ash by maintaining the fluid pressure in the chamber equal to or slightly higher than the internal reactor gas pressure. Consequently, for preventing the flow of reactor gases, while permitting the free gravitational flow of ash to a pressure letdown device, the control port of the chamber is designed for specified conditions, and a valve is operated to control the pressure of the control fluid (e.g., steam) into the chamber. In order for the system to operate under varying conditions, such as a varying rate of flow of ash from the lockhopper into the pressure letdown device, the chamber is provided with a pivotal D-shaped throttling sector in the inlet passage of the control fluid to allow for independent adjustment of the volume and velocity of control fluid into the chamber, which is shown to be steam from a cooling water jacket around the ash lockhopper, but may be any suitable fluid from another source.
The control chamber operates to maintain a fluidic force balance between the chamber pressure and the reactor pressure using a pressure controller which compares the reactor pressure with the chamber pressure, and adjusts the pressure of the control fluid in the chamber. The chamber is configured as a shallow disk-like chamber having an internal side wall that is kidney shaped, and a height that is significantly smaller than the transverse dimensions of the chamber. The ash exit port in the bottom of the chamber is positioned at the center of the chamber, and the ash inlet port at the top end of the chamber is offset from the exit port. The control fluid enters through the side wall and passes across the inlet port in a direction toward the side wall at the small end of the kidney shaped chamber to direct the flow of ash toward the side wall which then deflects, thereby creating a vortex that passes around and then over the exit port. While some control fluid will exit with the ash, the pressure of the control fluid in the chamber is continuously controlled to equalize, or even exceed slightly, the pressure in the reactor, and thus prevent any flow of toxic gas out of the reactor vessel.
STATEMENT OF THE INVENTION
An object of this invention is to provide a fluidics flow control chamber for multiphase flow control applications such as, for example, control of coal slurry flow into a reactor vessel and/or control of ash flow from the reactor vessel without any mechanical moving parts in the control chamber.
These and other objects and advantages are achieved in accordance with the present invention by utilizing a cylindrical chamber having a height significantly smaller than the diameter of the cylindrical chamber, an exit port centered in one planar end wall of the cylindrical chamber, and a supply port in the circular side wall of the chamber. The supply flow enters radially and, barring any control fluid flow, moves directly toward the exit port. Control fluid of relatively small volume flow and greater velocity than the supply flow is introduced into the chamber through a port tangent to the circular wall of the chamber. The control flow follows the circular wall of the chamber which deflects the supply flow to set up a vortex within the chamber. That vortex decays into a spiral pattern that eventually carries the supply flow to the exit port at the center of the chamber. The vortex of the control fluid exerts a centrifugal force against the circular wall of the chamber proportional to the square of its velocity (v 2 ). This pressure due to centrifugal force is exerted radially everywhere in the chamber against the circular wall and the inlet port in opposition to supply fluid pressure.
The control port is set about 90° ahead of the supply port to begin the control fluid vortex before encountering the supply flow. A second control port may be provided ahead of the first control port to start the vortex even earlier, which is then reenforced by the first one downstream for better control of the supply flow, but at the expense of using a larger total of control fluid flow without improvement in the ratio of control fluid pressure to the supply fluid pressure. To achieve a greater reduction in control fluid pressure, a second set of control and supply ports is provided consisting of a second supply port opposite the first, and a second control port opposite the first, thus placing each two control ports about 90° ahead of each two supply ports. This arrangement significantly reduces the ratio of control fluid pressure to supply fluid pressure. Three sets of supply and control ports could be used, oriented at 120° from each other, but improvement in the ratio of control to supply fluid pressure is small compared to the increase of the flow ratio of control fluid to supply fluid.
The novel features that are considered characteristic of this invention are set forth with particularly in the appended claims. The invention will best be understood from the following description when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates shcematically the prior-art continuous flow lockhopper with a fluidics control chamber in accordance with the copending application cited hereinbefore.
FIGS. 2a and 2b illustrate a sectional side view and a sectional plan view, respectively, of a vortex control chamber which is the subject of the present invention.
FIG. 3 illustrates schematically a plan view of a second embodiment of a control chamber similar to that shown in FIGS. 2a and 2b.
FIG. 4 illustrates schematically a preferred variation of the embodiment of FIG. 3.
FIG. 5 illustrates a pressure letdown device with a fluidics flow control chamber of the present invention comprised of perforated plates separated by plenum chambers, with one plenum chamber replaced by the fluidic flow control chamber for control of supply flow rate.
FIG. 6 illustrates in an exploded isometric view one example of a fluidic flow control chamber for the pressure letdown device of FIG. 5.
FIG. 7 illustrates schematically the force balance of the fluidics control chamber of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 2a, which discloses a cylindrical fluidic force balance control chamber 10, the supply flow from an ash lockhopper, or a coal slurry supply flow into a reactor, enters radially through a port 11 into the cylindrical chamber 10 having a circular exit port 12 at the bottom center of the chamber 10. As can be seen in FIG. 2a. The fluidics control chamber 10 may be assembled from three plates 10a, 10b and 10c shown in FIG. 2a. The top plate 10a is a flat cover for one side of the plate 10b machined in the configuration shown in FIG. 2b, which is a sectional view taken on a line 2b-2b in FIG. 2a. The principal part machined in the plate 2b is the chamber itself. The height of the chamber is equal to the thickness of the plate 10b. It is also machined to form the radical and tangential ports 11 and 13. A flat plate 10c with the exit port 12 in the middle closes the fluidics control chamber 10 at the other end. Barring any means for control, an uncontrolled flow of ash entering radially through the supply inlet port 11 travels directly to the exit port 12.
Control fluid enters the chamber 10 through the tangential port 13 to allow a control flow of a relatively small volume of fluid to enter (at a greater velocity than ash entering the chamber) and set up a circular flow pattern contained by the cylindrical wall of the chamber. The flow of combined control fluid and ash gradually moves away from the cylindical wall in a spiral path, and finally exits through the port 12. The vortex of control fluid exerts a pressure against the wall proportional to its velocity squared, and inversely proportional to the radius of the chamber. This pressure due to centrifugal force acts everywhere radially outward, against both the cylinder wall and the supply port in opposition to gas pressure in the reactor. Thus, the greater the control fluid pressure and flow, the smaller the flow of gas from the supply inlet port, and at a point where the force due to the pressure resulting from the centrifugal force plus the pressure in the control chamber, exactly equals the gas pressure in the reactor, there is no gas flow from the reactor. That point is termed the cutoff point. The only fluid that flows out of the control chamber is the control fluid, but the solid ash particles continues to flow down through the control chamber under the force of gravity.
Using this device in the continuous flow ash lockhopper, with the control port located 90° ahead of the supply port, as shown in FIG. 2b, it was found that complete cutoff of the reactor gas could be attained. However, the fluidics control chamber for the ash lockhopper application, i.e., for the control of ash flow into the pressure letdown device shown in FIG. 1, a fluidics control chamber shown in FIG. 4 is preferred in order to lower flow velocity, and therefore reduce erosion caused by the ash flow.
In order to improve the turndown ratio, obtain better control, and reduce the control pressure needed at cutoff, the control port was moved next to the supply port, where it could impinge directly on the supply stream at right angles. This resulted in a degradation of control; it is believed that this destroyed the vortex and resulted only in turbulent flow mixing the control flow with the supply flow. By adding a second control port 14 90° ahead of the orginal vortex generator port 13, i.e., by adding a control port diametrically opposite the supply port, as shown in FIG. 3, better control resolution of the supply flow was sought. The intent was that the second control port would start the vortex motion of the control fluid, which then would be reinforced by the control flow from the original port 13, thus opposing reactor gas in the supply flow more positively, and obtaining better control. This approach did yield better control resolution, but exhibited a significant degradation in the turndown ratio--more control fluid was required than before. In addition, there was no improvement in the control pressure needed to ensure reactor gas flow cutoff. It is believed that the second control port 14 merely lowered the entrance velocity of the control fluid stream vis-a-vis that of the supply stream; and the latter was not being sufficiently diverted to flow along the chamber wall.
The solution to providing optimum control in the chamber is to add a second supply port 15 as long with the second control port 14, as shown in FIG. 4, i.e., to have two sets of ports with the control port of each set ahead of the supply port by about 90° so as to halve the velocity of the supply stream while retaining the leading angle of the original port 13 and obtaining symmetry. It is expected that a reduction in cutoff pressure ratio could be achieved by adding yet another set of ports disposed 120° apart, particularly for coal slurry supply control, but the improvement could only be minor for in no case can the control fluid pressure at cutoff drop below the coal slurry supply pressure. With the configuration of FIG. 4, control pressure is only 25% higher than coal slurry supply pressure. In considering the original configuration where control fluid pressure in the chamber exceeded coal slurry supply by 450%, it can be fairly concluded that all possible substantial gains in this ratio have been made by the configuration of FIG. 4.
For use of the fluidics flow control chamber shown in FIGS. 2 through 4 as a coal slurry letdown valve at the top of the reactor shown in FIG. 1, a "porous plug" arrangement shown in FIG. 5 is employed. In that arrangement, coal slurry supply pressure is reduced through a series of successive flat plates P 1 , P 2 , ... P n while maintaining low velocities through each of the plates. The "porous plug" principle is based on isenthalpic pressure drop through a plug composed of very small passages, which are not possible in a coal slurry application due to the size of the coal particles and the plugging potential of the larger particles. Therefore a quasi porous plug was conceived to overcome the problem by J. Kendall as disclosed in U.S. Pat. No. 4,418,722.
The pressure letdown device in that patent is comprised of conical plates with apertures of uniform size increasing in number, and therefore increasing in total area, as flow progresses downstream. In this invention, the pressure letdown device is comprised of a number of stages, with each stage consisting of a plenum chamber and a perforated plate. The plates are flat, as shown in FIG. 5, and are positioned between plenum chambers PC 1 , PC 2 ... PC n comprised of hollow cylindrical sections. The number and size of apertures are chosen to provide a total flow area large enough to pass entrained particles and maintain a low velocity in order to reduce erosion caused by the abrasive solid particles.
A process stream containing a flashing component will have increased volumetric flow rate during pressure letdown due to the vapor generated by the drop in pressure at constant or near constant temperature. The aperture areas in the perforated plates are increased in progression to maintain a constant velocity through the preforated plates, i.e., to accomodate the volumetric flow rate. Control of the flow is accomplished by a fluidics control chamber FCC between stages, such as in place of a plate between plenum chambers PC n-1 and PC n for enough downstream in the pressure letdown device to be subject to low velocity flow, as shown in FIG. 5.
The fluidics control chamber for this application may be fabricated using three plates a, b and c machined in the configurations of plates A, B and C shown in FIG. 6, for example, with one set of ports as shown in FIGS. 2a and 2b for simplicity of illustration, but preferably with two sets of ports as shown in FIG. 4. The lefthand end plate A is made of a thin metal sheet with an aperture 21 situated to feed into an aperture 22 in a thicker metal plate B having a control chamber 23 machined through it along with a channel for the supply flow from the aperture 22 into the chamber 23, and a channel for the control flow into the chamber. A thin metal plate C with a port 24 is placed on the right of the chamber 23 to close it, except for the exit port 24 at the center of the chamber 23. A plenum chamber PC n permits the exit flow to disperse to all of the apertures in the following plate P n .
The fluidics control chamber designed in accordance with the schematic diagram of FIG. 4 is preferred because a smaller control flow rate (brought forward from the main control supply line, or an auxiliary control flow line) can modulate the slurry flow. As noted hereinbefore, that is done by producing a vortex induced spiral flow in the control chamber. The spiral increases the centrifugal force and adds flow resistance to the supply stream, thereby reducing supply flow rate. The control fluid enters the control port and, by providing pressure and centrifugal forces against the entering supply flow, regulates the supply flow rate through the flow control chamber. The effectiveness of flow control may be quantified through the turndown ratio, TR defined as: ##EQU1## Cutoff of the supply flow is achieved when the supply flowrate is reduced to zero.
Tests have confirmed that control of pure liquid flow could be achieved with the design of FIG. 2, but only with a very high control-to-supply flow-pressure ratio, P c /P s . To overcome the problem, the design of FIG. 4 was developed with two supply and two control ports. Later tests with the design of FIG. 4 using water showed considerably improved performance. When this solution was tried, it was found that there was a significant improvement in turndown ratio, but a large unexpected improvement in cutoff pressure ratio. Using water as a control fluid for the experiment, it now took only 100 psig control fluid pressure to cut reactor gas flow off with 80 psia reactor gas pressure; a cutoff pressure ratio of 1.25:1, representing an improvement of 440%. The design of FIG. 4 was then subjected to a much more severe test in a 20-stage pressure letdown device of the type shown in FIG. 5 using a slurry consisting of 75% No. 2 diesel fuel, 22% pulverized (220 mesh) coal, and 3% n-Pentane, by weight. The results proved quite successful in that cutoff of the supply flow at 1.38 MPa was achieved with P c /P s =1.25 and TR=3.09.
The force balance of the fluidics control chamber of the present invention is illustrated schematically in FIG. 7 by a segment of the chamber between the exit port, at which the exit pressure is Po, and the chamber wall at the supply port, at which the supply pressure is P s . The control flow vortex created in the chamber moves along the chamber wall at a tangential velocity V o and produces a centrifugal force against the wall, and therefore the supply flow port as well is equal to 1/2 ρ V o 2 , where ρ is the density of the control fluid. At zero supply flow, the supply pressure is balanced by the centrifugal force and exit pressure, as given by the following equation:
A.sub.1 P.sub.s -A.sub.2 P.sub.o -0.5ρV.sub.θ.sup.2 (πDH)=0
where A 1 is the area over which the supply pressure P s is applied, A 2 is the area over which the exit pressure P o is applied, D is the control element diameter and H is the height of the control element chamber.
In tests for the balanced condition using water for both the supply and the control fluid, the ratio of the control fluid pressure P c to the supply fluid pressure P o was found to be 4.4 and 4.8 for the two-port and three-port configurations of FIGS. 2 and 3, and only 1.21 for the four-port configuration. With diesel No. 2 as the supply and control fluid, the ratio P c :P s was found to be 1.8, which is still a very good ratio in considering flow control of the coal slurry referred to hereinbefore with diesel No. 2 as the control fluid.
The turndown ratio, which is the ratio of output flow with a letdown device and no contol to output flow with control, i.e., the ratio of uncontrolled supply flowrate to the sum of controlled supply flowrate and control fluid flowrate, all with a letdown device is given by the following table for the two-part, three-port and four-port configurations of FIGS. 2, 3 and 4 by the following:
______________________________________ P.sub.s P.sub.c Supply and TurndownPorts (psia) (psia) Control Fluid Ratio______________________________________2 95 15 Water 1.0 95 165 1.19 95 415 2.113 95 15 Water 1.0 95 195 1.5 95 455 3.334 95 15 Water 1.0 95 115 2.734 95 15 Diesel No. 2 1.0 95 170 2.4______________________________________
From the table above, it is clear that the four-port configuration of FIG. 4 for the fluidics flow control chamber with a letdown device provides better performance in the turndown ratio over the two-port configuration of FIG. 2 by a factor of better than 2, while the three-port configuration of FIG. 3 shows some improvement by a factor of about 1.25 to 1.58, with the improvement increasing from the factor of 1.25 to 1.58 as the control fluid pressure increases to 455 psia. Thus, from the point of view of the ratio of control fluid pressure to supply fluid pressure at cut off, and the turndown ratio, the four-port configuration of FIG. 4 is to be preferred.
Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art. Consequently, it is intended that the claims be interpreted to cover such modifications and variations. | Fluidics flow control of a multiphase supply using a cylindrical chamber is achieved by introducing the supply flow radially into the chamber. The supply flow exits through a port in the center at the chamber. A control fluid is then introduced tangentially about 90° upstream from the supply port. A second control fluid port may be added about 90° upstream from the first control fluid port, but preferably two sets of supply and control ports are added with like ports diametrically opposite each other. The control fluid flows against the circular wall of the control chamber, which introduces a vortex in the flow of the supply flow that decays into a spiral path to the exit port in the center of the chamber. The control flow rate may thus be used to control the spiral path, and therefore the supply flow rate through the exit port. | 5 |
CLAIM OF PRIORITY
This application is a 371 of PCT Patent Application No. PCT/EP05/03786, filed Apr. 11, 2005.
FIELD OF THE INVENTION
The invention relates to the communication of data and, more specifically, to a technique for controlling streaming data packet transmissions.
BACKGROUND OF THE INVENTION
Increasing amounts of data are being transmitted from servers to clients via communication infrastructures such as packet-based Internet Protocol (IP) networks. One particular application that is increasing in popularity is multimedia streaming. However, improvements must be made in providing reliable data streams before wide-spread adoption of such services. For example, as data transmission link rates between the IP network and a client device of a user tend to fluctuate, any disturbances in data delivery to the user may result in severe degradation of the playout to the end user, i.e. a degradation in the quality of the media observed by the user. In particular, it is important that there be a sufficient supply of packets of data at the client device to be fetched by a multimedia application as playout (i.e., the display of the multimedia file by the multimedia application or player) progresses.
In many cases, the packet transmission rate cannot be changed, as this rate depends upon the bandwidth of communication link (or it is at least impractical to change the packet transmission rate). However, the rate at which data is fed to the output device of the user often must be changed. Typically, for streaming applications, such adjustments are achieved using “stream switching”. With stream switching, the same media content, e.g. a particular video sequence, is pre-encoded at different bit rates and stored at the server. Hence, different versions of the same stream are available. During transmission, the server selects the particular version that has a data bit rate most appropriate based upon the current available bandwidth in the network and based upon the status of the client buffer. Switching logic employed by the server decides if and when to switch to another version of the stream. In the case of a so-called “down-switch”, the stream is switched to a version with a lower encoded bit rate. In the case of an “up-switch”, the switch is made to a version with a higher encoded bit rate. In many implementations, the criteria for switching employs predefined thresholds defined with respect to client buffer status. In one example, thresholds are based upon a buffer fill level, which represents the amount of data within the client buffer in bytes. In another example, the thresholds are based upon a playout length (PT) of stored media in the client buffer, which represents the amount of time in seconds it will take for the data already within the client buffer to be played out to the user. Herein, examples involving playout length are described, though buffer fill level or other appropriate parameters can instead be used.
Some conventional techniques for determining the status of the client buffer utilize information within Real Time Transport Control Protocol (RTCP) receiver reports (RRs). Information pertaining to the next sequence number (NSN) or oldest buffered sequence number (OBSN) within the client buffer and the highest received sequence number (HRSN) within the client buffer is contained with the RR and is used to determine the consumed buffer space as the size of each packet within the range from the HRSN to the NSN/OBSN is known. If the free space within the client buffer is below a preferred client buffer fill level, then a different version of the stream is selected. For example, if buffer playout length (PT) falls below a predetermined minimum threshold (PT DOWN ), then a risk of buffer draining occurs, i.e. the client buffer becomes empty such that there is no data to stream to the user. This results in a playout freeze, wherein the last image displayed to the user is typically frozen until a sufficient amount of additional data can be added to the client buffer to restart the stream to the output device employed by the user, i.e. a “rebuffering” of the client buffer is required. Rebuffering can be extremely annoying from the standpoint of the user.
To avoid possible rebuffering due to client buffer draining, the server detects when the playout length (PT) within the client buffer drops below threshold PT DOWN , then adjusts the bit rate (i.e. selects a version of the stream having a different bit rate) in an attempt to prevent the client buffer from becoming completely drained. More specifically, the server performs a down-switch, i.e. a switch to a lower bit rate stream. The reason that a down-switch is performed, rather than up-switch, is that the most likely reason that the client buffer is being drained is that the link rate between the server and the client buffer is less than anticipated, i.e. the effective bandwidth is less than needed for the bit rate currently being used. As a result, data is not being received by the client buffer at the same rate at which the client buffer is feeding data to the output device of the user. Hence, the client buffer, which should remain fairly well populated with data, becomes drained. By switching to the lower bit rate, the client buffer feeds data to the display unit at a lower rate, thereby allowing more time for data to be received from the server, and thereby preventing the client buffer from becoming completely drained. From the standpoint of the user, the quality of the media stream is downgraded because of the down-switch, e.g. the size of the displayed image of the video stream becomes smaller, the resolution of the image becomes less, or higher distortions are observed in the image. Yet, this is preferable to the aforementioned playout freeze that occurs during rebuffering.
On the other hand, if buffer playout (PT) length exceeds a predetermined maximum threshold (PT UP ), then a risk of buffer overflow occurs, i.e. the client buffer becomes full such there is no room for additional packets. Any packets received by the client buffer but not stored therein are typically not re-sent by the server and hence the data of those packets are simply not forwarded to the output device of user. Once the client buffer is again capable of storing packets, the data stream resumes with the new packets. Thus, from the standpoint of the user, there is a sudden loss of content as the stream simply jumps ahead. In the case of a film or movie, dialogue can be lost, thus interfering with the ability of the user to follow story. In the case of music, the song simply jumps ahead. As will be appreciated, this can be quite annoying from standpoint of the user as well.
To avoid a disruption of the stream due to client buffer overflow, the server detects when the playout length (PT) within the client buffer exceeds threshold PT UP and then performs an up-switch, i.e. a switch to a higher bit rate stream. The reason that an up-switch is performed, rather than down-switch, is that the most likely reason that the client buffer is becoming to full is that the link rate between the server and the client buffer is greater than anticipated, i.e. the effective bandwidth is greater than needed for the bit rate currently being used. As a result, data being received by the client buffer at a rate higher than the rate at which the client buffer feeds the data to the output device of the user. Hence, the client buffer overflows. By switching to the higher bit rate, the client buffer feeds data to the output device at the higher rate, thereby preventing the client buffer from overflowing. From the standpoint of the user, the quality of the media stream is improved due to the up-switch, e.g. the size of the displayed image of the video stream becomes larger or the resolution of the image becomes greater. Hence, the up-switch helps prevent interruption of the stream and improves media quality, which both benefit the user.
Simple logic for performing up-switches and down-switches may be represented as follows:
If PT>PT UP then
Perform up-switch
else if PT<PT DOWN
Perform down-switch
end if.
Appropriate selection of these thresholds is critical to the overall media impression of the user. In the case of down-switch that is performed too late, a rebuffering event will happen. In the case of an up-switch that is performed too late, the user receives a lower quality media then is otherwise necessary and, as noted, a break in the data stream may occur as the result of a buffer overflow. Likewise, if a down-switch is performed earlier than necessary, the user receives a lower quality media than is otherwise necessary. If an up-switch is performed earlier than necessary, a down-switch may then soon be required, resulting in annoying fluctuations in the quality of the media. To avoid these problems, multiple down-switch thresholds and multiple up-switch thresholds can potentially be used. As playout length decreases towards buffer drainage, a series of the down-switch thresholds are crossed, each triggering a down-switch. Conversely, as playout length increases towards buffer overflow, a series of up-switch thresholds are crossed, each triggering an up-switch.
However, after a switch has occurred and a stream with the new bit rate has been transmitted, it takes some time before the switch has any effect on the playout length of the client buffer. First, there is a transmission delay until a first packet containing data encoded at the new rate reaches the client buffer. During this time period, the playout length of the stored media in the client buffer is unaffected by the new rate. Hence, if the playout length was increasing toward a possible buffer overflow, it will likely continue to increase. Conversely, if the playout length was a decreasing toward possible buffer drainage, it will likely continue to decrease. Also, even after the arrival of the first packet at the new bit rate, the playout length may change only slowly at first. For example, there may still be some packets sent with data at the previous bit rate that had not yet been received by the client buffer. Therefore, the switching conditions are often still valid and several switches then follow a first switch, which are often unnecessary. In the case of a first down-switch, several further down-switches may be performed, resulting in a stream bit rate that is much lower than necessary. Often, the down-switches do not stop until the lowest stream bit rate has been selected. This behavior results in an unnecessarily low media stream quality for the user. In the case of an up-switch, several further up-switches can happen, resulting in a stream bit rate that is too high, often to the highest rate possible. This results in a stream bit rate that is much too high compared with the current available network bandwidth, triggering a series of down-switches.
As a result, frequent and annoying variations in stream quality are observed by the user. Moreover, if a bit rate that is much too high has been selected, subsequent down-switches often cannot be executed fast enough, resulting in annoying rebuffering events and playout freeze. Likewise, if a bit rate that is much too low has been selected, subsequent up-switches often cannot be executed fast enough, resulting in annoying buffer overflows and associated loss of data. Even with only a single up-switch threshold and a single down-switch threshold, these sorts of problems can arise, particularly if the thresholds are set too close together.
Even more problems can arise when transmitting media content that has a variable bit rate. Conventionally, each pre-encoded version of the multimedia stream has a single bit rate, and hence the bit rate of a stream only changes if the server switches to a different stream having a faster or slower rate, as already described. However, in some cases, it is appropriate to provide streams with a varying bit rate, particularly to accommodate storage and transmission of large media files. In other words, each version of a stream may have portions at one bit rate and other portions at another. Preferably, the bit rate for individual sections of a particular version of a stream is chosen based on the content of the individual section. For example, one portion of a stream may be fairly static, permitting a low bit rate to adequately capture the content. Thereafter, a higher bit rate may be needed to adequately capture more dynamic content. By setting the bit rate of each portion of a multimedia stream based on the dynamic content of that portion of the stream, overall file size can be reduced while still adequately conveying the content.
When applying conventional stream switching techniques to variable bit rate streams, various problems can arise. In particular, the changing bit rates of the stream can compound the aforementioned problems, resulting in even more frequent and unnecessary switches, causing further annoyance to the user and, often, wasting bandwidth.
Accordingly, there is a need for an improved technique for controlling stream switching of variable bit rate data so as to provide more stable and reliable content to user, and it is to this end that the invention is principally directed.
SUMMARY OF THE INVENTION
The invention may be embodied in a method for controlling packet transmissions of variable bit rate data from a server to a client having a client buffer wherein the server switches among different versions of a stream of variable bit rate data being transmitted based on a status of the client buffer. In accordance with the method, an initial version of a stream of variable bit rate data is selected for transmission and a value (PT) representative of an amount of data within the client buffer is tracked. A bit rate (BR) of a portion of variable bit rate data yet to be transmitted within the selected version of the stream is determined. Then, switches to different versions of the stream, having different mean bit rates, are controlled by the server based on the value (PT) representative of the amount of data within the client buffer in combination with the bit rate (BR) of the portion of variable bit rate data yet to be transmitted.
In one example, the bit rate (BR NEXT ) of the next sequential portion of data to be transmitted is determined. If a BR NEXT exceeds an average bit rate (BR AVE ), then the step of controlling switching is performed to delay any switch to a version of the stream having a generally higher bit rate, i.e. up-switches are delayed.
In another example, if BR NEXT exceeds the average bit rate (BR AVE ), the step of controlling switching is performed to expedite any switch to a version of the stream having a generally lower bit rate, i.e. down-switches are expedited.
In yet another example, if BR NEXT is below the average bit rate (BR AVE ), the step of controlling switching is performed to expedite any switch to a version of the stream having a generally higher bit rate, i.e. up-switches are expedited.
In a preferred implementation, the server controls switches to different versions of the stream based on a current status of the client buffer by applying one or more thresholds to data already in the client buffer. The step of controlling switching is performed by dynamically adjusting the one or more thresholds based on the bit rates (BR) of the portion of variable bit rate data to be transmitted and then determining whether to switch to a different version of the stream by applying the one or more adjustable thresholds to the value (PT) representative of the amount of data within the client buffer.
In an example of the preferred implementation, the one or more thresholds include an up-switch threshold (PT UP ) and a down-switch threshold (PT DOWN ). The step of dynamically adjusting the one or more thresholds is performed by determining an average bit rate (BR AVE ) of the variable bit rate data and then selectively adjusting is the up-switch and down-switch thresholds (PT UP and PT DOWN ) based on a comparison of the bit rate (BR NEXT ) of a next portion of variable bit rate data to be transmitted with the average bit rate (BR AVE ) of the variable bit rate data. The step of selectively adjusting the up-switch and down-switch thresholds includes the step of increasing the up-switch and down-switch thresholds (PT UP and PT DOWN ) if the bit rate (BR NEXT ) of the next portion of variable bit rate data exceeds the average bit rate (BR AVE ). The step of selectively adjusting the up-switch and down-switch thresholds also includes the step of decreasing the up-switch threshold (PT UP ) if the bit rate (BR NEXT ) of the next portion of the variable bit rate data is below the average bit rate (BR AVE ) and if the up-switch threshold (PT UP ) exceeds the down-switch threshold (PT DOWN ). In other words, PT UP is not adjusted downwardly if it would then fall below PT DOWN .
In the preferred implementation, the step of increasing the up-switch and down-switch thresholds (PT UP and PT DOWN ) if the bit rate (BR) of the next portion of variable bit rate data exceeds the average bit rate (BR AVE ) is performed by determining the bit rate (BR NEXT ) of the next portion of variable bit rate data then calculating a ratio (F) of the bit rate (BR NEXT ) of the next portion of variable bit rate data to the average bit rate (BR AVE ). The up-switch and down-switch thresholds (PT UP and PT DOWN ) are then multiplied by the ratio (F) to thereby increase the thresholds. The step of decreasing the up-switch threshold (PT UP ) is also performed by determining the bit rate (BR NEXT ) of the next portion of variable bit rate data and then calculating a ratio (F) of the bit rate (BR NEXT ) of the next portion of variable bit rate data to the average bit rate (BR AVE ). The up-switch threshold (PT UP ) is then multiplied by the ratio (F) to thereby decrease the threshold. Then, the larger of the decreased up-switch threshold (PT UP *F) and the down-switch threshold (PT DOWN ) is selected for use as a new up-switch threshold.
In various implementations, the values representative amounts of data within the client buffer are representative of playout lengths (PT) of the data or buffer fill levels. The average bit rate (BR AVE ) may be representative of an average bit rate over the entire version of the stream being transmitted or may instead be representative of an average bit rate of data that has already been transmitted within the version of the stream being transmitted.
Depending on the implementation, the client may be a mobile communications terminal such as a mobile telephone, and in addition, or in the alternative, the server may be integrated into a mobile communications terminal so that the link between the server and the network may be wireless. In addition, the method according to the present invention may be performed by one or more intermediary network nodes (such as proxies) arranged between the server and the client. The method may also be utilized in architectures having plurality of data streams being buffered by the client buffer (or multiple client buffers depending on the configuration of the client).
The invention may also be embodied in a computer program product, which may be stored on a computer readable recording medium, comprising program code portions for performing any of the steps of the above methods when the computer program product is run on a computer system.
The invention may further comprise an apparatus comprising a computer processor and a memory coupled to the processor, where the memory is encoded with one or more programs that may perform any of the steps of the above methods.
In yet another embodiment, the invention relates to an apparatus for controlling packet transmissions of variable bit rate data from a server to a client having a client buffer wherein the server switches among different versions of a stream of variable bit rate data being transmitted based on a status of the client buffer. The apparatus comprises: an anticipatory variable bit rate stream transmission controller for selecting an initial version of a stream of variable bit rate data for transmission; a client buffer monitor for tracking a value representative of an amount of data within the client buffer; a variable bit rate determination unit a bit rate (BR) of a portion of variable bit rate data yet to be transmitted within the selected version of the stream; and wherein the anticipatory variable bit rate stream transmission controller then controls switches to different versions of the stream, having different mean bit rates, based on the value (PT) representative of the amount of data within the client buffer in combination with the bit rate (BR) of the portion of variable bit rate data yet to be transmitted
The apparatus may be configured as a fixed or mobile network component, such as a network server and/or a wireless terminal. In addition, the apparatus may be constituted by an intermediary network node, such as a proxy.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following the invention will be described with reference to exemplary embodiments illustrated in the figures, in which:
FIG. 1 is a schematic diagram of a communication system useful for understanding and implementing the invention;
FIG. 2 is a process flow diagram providing an overview of a method embodiment of the invention;
FIG. 3 is a graph illustrating various versions of a stream of variable bit rate data, particularly illustrating different mean bit rates of the various versions of the stream;
FIG. 4 is a block diagram of a single stream of variable bit rate data, particularly illustrating bit rates of various portions of the stream;
FIG. 5 is a process flow diagram illustrating an exemplary implementation of variable bit rate logic of the invention;
FIG. 6 is a block diagram of a client buffer, particularly illustrating various thresholds employed by the invention;
FIG. 7 is a block diagram illustrating an exemplary apparatus implementation of a server component of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular sequences of steps and various configurations, in order to provide a thorough understanding of the invention. It will be apparent to one skilled in the art that the invention may be practiced in other embodiments that depart from these specific details. Moreover, those skilled in the art will appreciate that the functions explained herein below may be implemented using software functioning in conjunction with a programmed microprocessor or general purpose computer, and/or using an application specific integrated circuit (ASIC). It will also be appreciated that while the invention is primarily described as a method, it may also be embodied in a computer program product as well as a system or apparatus comprising a computer processor and a memory coupled to the processor, where the memory is encoded with one or more programs that may perform the methods disclosed herein.
FIG. 1 illustrates a sample architecture 100 that may be used in connection with the invention including a server 105 that may be coupled to a client 115 via a communications pathway such as an IP network 110 . The server include a media content module 120 that accesses and transmits certain media content (e.g., multimedia data files) via a RTP/UDP module 125 using a streaming standard such as RTP (Real time Transport Protocol) over UDP or other data transport protocol for managing the realtime transmission of multimedia data (with a transport layer protocol such as UDP—User Datagram Protocol). The packets are transmitted to a public network 130 (e.g., the Internet, however, an external public network is not required when the server is directly coupled to the operator network 135 ) that delivers the packets to an operator network 135 , such as a mobile communications operator “wired” network, coupled thereto.
The operator network 135 includes a core network 140 that provides communication links between the server 105 and the client 115 . The core network 140 , which may optionally have a buffer, provides the packets received from the RTP/UDP module 125 for buffering in a buffer within a radio access network (RAN) 145 (such as a buffer in the SGSN or in the RNC) prior to their transmission by a wireless transmitter 150 . The buffers of the core network 140 (if buffering is utilized) and the RAN 145 are arranged in series and constitute a network buffer.
The client 115 receives the packets transmitted by the wireless transmitter 150 in a client buffer 155 . The packets are transferred from the client buffer 155 to a RTP/UDP module 160 for delivery to and use by the media application module 165 (or multimedia player). For purposes of this application, the phrase “packet transmission rate” will refer to the rate of transmission of packets from the server 105 to the IP network 110 , the phrase “link rate” will refer to the rate of transmission of packets from the IP network 110 to the client 115 , and the phrase “content rate” shall refer to the rate that data is transferred from the client buffer 115 to the media application module 165 for playout by the media application module 165 .
With reference to FIG. 2 , a method embodiment 200 of the invention is illustrated which may be performed, for example, by the system of FIG. 1 . The method is preferably implemented by the server, such as a server 105 of FIG. 1 , but may be implemented by any other appropriate network component. In the following descriptions, it will be assumed that a server implements the steps of the method. Beginning at step 202 , the server selects an initial version of a stream of variable bit rate data for transmission. The initial version of the stream is selected, in accordance with otherwise conventional techniques, from among a group of different versions of the stream having generally different pre-encoded transmission rates. For example, a first stream may begin with a bit rate of 1 megabit (Mbit)/second, whereas a second stream may begin with a bit rate of 2 Mbits/second. Since the stream itself has a variable bit rate, each version of the stream likewise has a variable bit rate. Hence, whichever version of the stream is selected, the bit rate of data encoded within the stream will change. For example, the first version of the stream may switch to a bit rate of 2 Mbits/second after ten seconds, whereas the second version of the stream may switch to a bit rate of 3 megabits Mbits/second after ten seconds, i.e. both versions of the stream have pre-encoded bit rates that increase by 1 Mbit/sec after ten seconds.
Three exemplary versions of a single bit stream are shown in FIG. 3 . Each version of the stream has a bit rate that varies with time. The versions are all synchronized with one another, i.e. the bit rates all increase at the same time or all decrease by the same time. However, the mean bit rates of the various versions of the stream differ from one another. The server performs up-switches and down-switches by switching between the different versions of the stream. In the example if FIG. 3 , only three versions of the stream are shown. Typically, more versions are pre-stored. Also, in the example, the lowest bit rate of the highest bit rate version 205 of the stream is at a higher rate than the highest bit rate of the next version 207 of the stream. Likewise, the lowest bit rate of version 205 of the stream is at a higher rate than the highest bit rate of version 209 . This, however, need not be the case. Often there is at least some overlap in bit rates. Also, in the example, the rate changes are shown as being smooth, i.e. the rate increases smoothly to a peak then decreases smoothly. This need not be the case either. In many examples, the bit rates change discontinuously, i.e. the rate jumps from one level (such as 1 Mbit/sec) to a different level (such as 2 Mbit/sec).
Returning to FIG. 2 , the selected version of the stream is transmitted at step 202 from the server to the client by taking pre-encoded data from the version of the stream and placing that pre-encoded data into data packets, which are transmitted at a predetermined packet transmission rate to the client. Note that any change in the bit rate of the variable bit rate data within a stream being transmitted does not typically require a change in the packet transmission rate, which is determined base upon bandwidth considerations. Likewise, the choice of one version of the stream over another version typically does not entail any changes in packet transmission rate.
At step 204 , the server tracks a value representative of the amount of data currently within the client buffer. This too may be performed in accordance with otherwise conventional techniques. In one example, if the client buffer is implemented in accordance with RTCP protocols, the server receives feedback from the client buffer, which includes the NSN/OBSN and HRSN data fields from which the amount of data in the client buffer is determined. As noted, the amount of data in the client buffer may be represented, for example, in terms of a playout length (PT), a client buffer fill level, or other appropriate value. In the following descriptions, examples will be described using playout length (PT).
At step 206 , the server determines the bit rate (BR) of a portion of the variable bit rate data yet to be transmitted. Preferably, it is the next sequential portion of data to be transmitted that the server examines, i.e. the server determines a value (BR NEXT ) representative of the bit rate of the next portion of data to be transmitted. The next portion of data may be defined, for example, in terms of a predetermined number of seconds worth of data to be transmitted or may be defined as that portion of data from the data currently being transmitted until a next preset change in the data. For example, if the pre-encoded stream of variable bit rate data is to maintain its current bit rate for the next 12 seconds before switching to another bit rate, then the next portion of data comprises the next 12 seconds worth of data.
FIG. 4 illustrates an exemplary version 208 of a stream of variable bit rate data being transmitted. The stream includes portions of differing bit rates, denoted BR #1 , BR #2 , BR #3 , BR #4 etc. BR #1 and BR #3 may both be, for example, 1 Mbit/second, whereas BR #2 and BR #4 may both be, for example, 2 Mbits/second. As can be seen, portions may be of different lengths, i.e. durations. In the example, arrow 210 denotes the point within the stream corresponding to data currently being transmitted. The next portion of data, therefore, is data commencing at point 210 . The rate of that data is BR #2 . If the next portion of data is defined in terms of that portion of data from the data currently being transmitted until a next preset change in the data, then BR NEXT is simply BR #2 . If, instead, the next portion of data is defined in terms of a predetermined number of seconds' worth of data to be transmitted, then the next portion of data may encompass two or more different bit rates. In that case, the server may be configured to simply select the first of those bit rates for use as BR NEXT or may instead be configured to calculate the average bit rate BR AVE over that predetermined period of time for use as BR NEXT . In any case, a value representative of the bit rate of some portion of data yet to be transmitted is determined at step 206 of FIG. 2 .
At step 212 of FIG. 2 , the server then controls switches to different versions of the steam, having the different mean bit rates, based on the value (PT) representative of the amount of data currently within the client buffer and based on the bit rate (BR) of the portion of variable bit rate data yet to be transmitted, e.g. the server controls up-switches and down-switches based upon both PT and BR NEXT . By taking into account the bit rate of data yet to be transmitted, in addition to PT, the server is capable of avoiding many of the unnecessary rate switches that occur in conventional systems employing only fixed rate switched thresholds.
Preferably, if BR NEXT exceeds BR AVE , any up-switch due to a change in the status of client buffer is delayed. In other words, if any increase in playout length within the client buffer would otherwise have triggered a switch to a different version of the stream having a generally higher transmission rate, that switch is delayed. If an up-switch were instead performed by the server prior to a point in the stream where the variable bit rate was due to increase anyway, the up-switch would likely be counterproductive and might necessitate a compensatory down-switch. In this regard, by performing an up-switch prior to a point in the stream where the bit rate of the variable bit rate stream increases, two bit rate increases thereby occur, one after the other. As a result, the bit rate is then probably higher than necessary, likely triggering a compensatory down-switch to prevent possible buffer drainage. By instead delaying an up-switch in circumstances where the bit rate of variable bit rate data is due to increase anyway, the server likely avoids both an unnecessary up-switch and a subsequent compensatory down-switch, thereby providing a more consistent level of media quality to the end-user.
Also preferably, if BR NEXT exceeds BR AVE , down-switch due to a change in the status of client buffer is expedited. In other words, if a decrease in playout length within the client buffer would otherwise have triggered a switch to a different version of the stream having a generally lower transmission rate, that switch is expedited if the variable bit rate is due to increase. By expediting the down-switch in circumstances where the bit rate of the data being transmitted is due to increase, the server thereby helps prevent a possible rebuffering event. If, on the other hand, the server did not anticipate the increase in bit rate within the variable bit rate data, a down-switch triggered by the playout length falling below the conventional fixed down-switch threshold (PT DOWN ) might be too late to prevent rebuffering given that the increasing bit rate of the stream itself will accelerate buffer drainage.
Preferably, if BR NEXT is instead below BR AVE , any up-switch due to a change in the status of client buffer is expedited. In other words, if an increase in playout length within the client buffer would otherwise have triggered a switch to a different version of the stream having a generally higher transmission rate, that switch is expedited if the variable bit rate is due to decrease. By expediting the up-switch in circumstances where the bit rate of the data being transmitted is due to decrease, the server thereby helps prevent a possible overflow event. If, on the other hand, the server did not anticipate the decrease in bit rate within the variable bit rate data, an up-switch triggered by the playout length exceeding the conventional fixed up-switch threshold (PT UP ) might be too late to prevent buffer overflow given that the decreasing bit rate of the stream itself will accelerate buffer overflow. Moreover, the expedited up-switch provides improved media quality to the user more promptly.
Note however, that when BR NEXT is below BR AVE , any down-switch due to a change in the status of client buffer is preferably not delayed (nor expedited). Rather, in that case, down-switches are preferably triggered based on the conventional fixed down-switch threshold (PT DOWN ). Although a down-switch could potentially be delayed in view of the fact that the bit rate of the variable bit rate data is due to decrease soon anyway, such is not performed in the preferred implementation of invention so as to avoid risk of buffer drainage.
Turning now to FIG. 5 , a preferred implementation of variable bit rate logic for use at step two 212 of FIG. 2 will now be described. Beginning at step 300 , the server determines values for PT UP and PT DOWN . PT UP and PT DOWN may be predetermined, fixed up-switch and down-switch thresholds and may be set in accordance with otherwise conventional techniques. At step 302 , the server determines values for BR NEXT and BR AVE . BR NEXT may be determined by examining the encoded bit rates associated with data to be transmitted, which is stored within the server or otherwise accessible by the server. In one example, BR AVE is calculated by examining a record of the encoded bit rates of data already transmitted (along the durations of time during which packets containing the data encoded at the various bit rates were transmitted.) Otherwise routine arithmetic may be used to calculate the actual average. In a second example, a BR AVE value for the entire stream may be calculated and stored beforehand (as the individual streams are encoded before the streaming session starts, individual BR AVE values may be determined for the individual streams before play out.) In other words, in that second example, BR AVE is not the average bit rate of only that portion of data that has already been transmitted but instead represents the average over the entire stream, i.e. BR AVE is the mean bit rate illustrated, e.g., in FIG. 3 .
At step 304 , the server calculates a value F, which is representative of a ratio of BR NEXT to BR AVE , i.e. F=BR NEXT /BR AVE . Hence, if BR NEXT exceeds BR AVE , F is then greater than 1.0. If BR NEXT exceeds BR AVE , F is then less than 1.0. In cases where BR NEXT is equal to BR AVE , F is then equal to 1.0. If no data has yet been transmitted (such that there is no current value of BR AVE ), then F is simply set to 1.0. If no data remains to be transmitted within a current stream of data, such that there is no current value for BR NEXT , then F is also preferably re-set to 1.0 for use in connection with a next stream of data to be transmitted.
At step 306 , the server sets an adjustable up-switch threshold (PT UP-ADJ ) equal to PT UP multiplied by F, i.e. PT UP *F, and also sets an adjustable down-switch threshold (PT DOWN-ADJ ) equal to PT DOWN multiplied by F, i.e. PT DOWN *F. Hence, if BR NEXT exceeds BR AVE , then PT UP-ADJ is greater than PT UP and PT DOWN-ADJ is also greater than PT DOWN . Conversely, if BR NEXT is below BR AVE , then PT UP-ADJ is less than PT UP and PT DOWN-ADJ is also less than PT DOWN .
The thresholds are illustrated in FIG. 6 , which provides a block diagram representation of client buffer 115 of FIG. 1 . In the example of FIG. 6 , the adjustable thresholds are greater than the corresponding fixed thresholds. Note that circumstances can potentially arise where PT UP-ADJ may be calculated to be greater than the maximum value of client buffer (MAX). This may occur if BR NEXT is quite a bit larger than BR AVE , yielding a high value for F. If that is the case, than PT UP-ADJ is simply set equal to MAX or to some other lesser, default value. In the extremely unlikely case that PT DOWN-ADJ is also calculated to be greater than MAX due to an extremely high value for F, then PT DOWN-ADJ is preferably also set to some default value, which is less than the default value to which PT UP-ADJ is set, thus assuring that PT DOWN-ADJ remains less than PT UP-ADJ .
Returning to FIG. 5 , at step 308 , the server begins determining values for PT, i.e. the current playout length of data already contained within the client buffer, tracked at step 204 of FIG. 2 . If, at decision step 310 , PT is greater than PT DOWN and PT is also greater than PT UP-ADJ , then an up-switch is triggered at step 312 . If not, then decision step 314 is performed wherein, if PT is less than PT DOWN or PT is less than PT DOWN-ADJ , then a down-switch is triggered at step 316 .
The logic of decision steps 310 and 316 may be represented as follows:
If PT>PT DOWN AND PT>PT UP-ADJ then
Perform up-switch
else if PT<PT DOWN OR PT<PT DOWN-ADJ
Perform down-switch
end if where, as noted, PT UP-ADJ =PT UP *F and PT DOWN-ADJ =PT DOWN *F.
Hence, an up-switch is triggered if the current playout length (PT) of the client buffer exceeds the adjustable up-switch threshold (PT UP-ADJ ), assuming that PT also exceeds PT DOWN . This latter condition prevents inappropriate up-switches in circumstances where a down-switch may be more appropriate. By triggering up-switches based upon the adjustable up-switch threshold, rather than on the fixed up-switch threshold, the server thereby takes into account the current status of the client buffer (as represented by PT) while also anticipating changes in bit rate within the variable bit rate data stream (via the adjustment of the up-switch threshold). This helps prevent other inappropriate up-switches.
Consider an example wherein the adjustable up-switch threshold is initially exactly equal to the fixed up-switch threshold. Hence, if the playout length of client buffer exceeds that threshold level, an up-switch is performed. If the bit rate of the variable bit rate data is then due to increase, the adjustable up-switch threshold will be increased so as to the greater than the fixed threshold. In that case, a further up-switch will only be performed if the playout length exceeds the new, higher threshold value. In other words, it becomes more difficult for an up-switch to be triggered since a higher threshold value must be exceeded thus delaying further up-switches in circumstances where such a delay is warranted, as discussed above in connection with FIG. 1 . Now consider an example wherein the adjustable up-switch threshold is again initially set equal to the fixed up-switch threshold but wherein the bit rate of the variable bit rate data is instead due to decrease. In the case, the adjustable up-switch threshold will then be lower than the fixed threshold. In that case, it becomes easier for an up-switch to be triggered thus expediting further up-switches in circumstances where one is warranted, as also discussed above.
Turning now to down-switches, a down-switch is triggered if the current playout length (PT) of the client buffer falls below either the fixed threshold PT DOWN or the adjustable down-switch threshold (PT DOWN-ADJ ). In other words, a down-switch is triggered if PT falls below the larger of the two down-switch thresholds. The fixed threshold is still used to trigger a down-switch so as to prevent a down-switch from being delayed so as to help prevent rebuffering events. However, a down-switch can be expedited, which occurs if PT falls below the adjustable down-switch threshold. As noted above, the adjustable down-switch threshold may turn out to be either above or below the fixed down-switch threshold. If it is below the fixed threshold, it is superfluous, as the fixed threshold is used to immediately trigger a down-switch anyway. However, if the adjustable down-switch threshold exceeds the fixed down-switch threshold, the adjustable down-switch threshold can then trigger an expedited down-switch, i.e. it becomes easier for a down-switch to be triggered thus expediting further down-switches in circumstances where warranted, as also discussed above.
If neither of the conditions of decision steps 310 and 314 are true, then processing returns to step 302 , wherein the values of BR NEXT and BR AVE are updated to reflect any changes therein, the adjustable thresholds are adjusted and the latest value for PT is input for applying to the various threshold values.
Thus, an exemplary method implementation has been described of a technique for adjusting the overall transmission rate of data in a packet-based system by switching among different versions of a pre-encoded stream. The packet transmission rate typically is not changed, as it depends upon the bandwidth of the communication link. However, in other implementations, the packet transmission rate may be changed as well using, for example, adaptive techniques.
Although the invention has been primarily described with reference to method implementations, apparatus implementations are also part of the invention. FIG. 7 illustrates, at a high-level, an exemplary apparatus implementation. Briefly, network component 400 , which may be a part of server 105 of FIG. 1 , includes an anticipatory variable bit rate stream transmission controller ( 402 ) for selecting ( 202 ) an initial version of a stream of variable bit rate data for transmission. A client buffer monitor ( 404 ) tracks a value representative of an amount of data within the client buffer. A variable bit rate determination unit ( 406 ) determines a bit rate (BR) of a portion of variable bit rate data yet to be transmitted within the selected version of the stream. The anticipatory variable bit rate stream transmission controller ( 402 ) then controls switches to different versions of the stream, having different mean bit rates, based on the value (PT) representative of the amount of data within the client buffer in combination with the bit rate (BR) of the portion of variable bit rate data yet to be transmitted, i.e. controller 402 anticipates changes in bit rate of the variable bit rate stream and controls up-switches and down-switches accordingly.
As can be appreciated by one of ordinary skill in the art, the current invention and the techniques associated therewith provide an enhanced end user perceived experience for applications such as multimedia streaming by avoiding client buffer overflows. Furthermore, the skilled artisan will also appreciate that there are many different techniques that may be used to determine client buffer fill levels, including estimations based on data within RRs and Sender Reports, and that the current invention may be implemented in parallel with a plurality of data packet streams simultaneously being buffered for transmission to one or more clients.
One of ordinary skill in the art will further appreciate that the invention may be implemented in and by various types of network components, such as network terminals, network nodes, and the like. In particular, the invention may be practiced by mobile terminals, proxies (that could divide the transmission path), and fixed terminals.
While the invention has been described with respect to particular embodiments, those skilled in the art will recognize that the invention is not limited to the specific embodiments described and illustrated herein. Therefore, while the invention has been described in relation to its preferred embodiments, it is to be understood that this disclosure is only illustrative. Accordingly, it is intended that the invention be limited only by the scope of the claims appended hereto. | A technique is disclosed for controlling data packet transmissions from a server to a client having a client buffer in accordance with a waiting mode and a dynamic mode. The waiting mode is performed before packets containing data encoded subject to a current bit rate have reached the client buffer; the dynamic mode is performed otherwise. In the waiting mode, down-switches to lower bit rates are allowed but up-switches to higher bit rates are disabled. In the dynamic mode, up-switches and down-switches are both allowed, with adjustments in the bit rate of packets controlled based, in part, on the amount of data contained within the client buffer when packets containing data encoded subject to the current bit rate first reached the client buffer. The two modes help avoid unnecessary rate switches. | 8 |
BACKGROUND OF THE INVENTION
In a principal aspect the present invention relates to a flashlight comprised of a light emitting diode (LED) light source mounted in a housing and powered by one or more disc shaped batteries of sufficient voltage. The flashlight includes a pocket clip which may be elastically deformed to complete or close the circuit to activate the light source.
The light source may have a selected wave length, for example, an infrared, ultraviolet or white light emitting diode. The choice of the light source enables the user of the flashlight to utilize the light for detecting materials that are reactive to infrared or ultraviolet radiation, for example.
There are numerous patents directed to the construction of flashlights wherein the light emitting diode light source is utilized as a means to detect fluid leakage, for example. Among the various patents directed to such light constructions are the following:
U.S. Pat. No.
Title
Issue Date
5,674,000
Light Source For Use In Leak Detection
Oct. 7, 1997
In Heating, Ventilating and Air
Conditioning Systems That Utilize
Environmentally-Safe Materials
5,742,066
Light Source For Use In Leak Detection
Apr. 21, 1998
In Heating, Ventilating and Air
Conditioning Systems That Utilize
Environmentally-Safe Materials
5,788,364
Compact High-Intensity UVA
Aug. 4, 1998
Inspection Lamp
5,959,306
Portable Light Source And System For
Sep. 28, 1999
Use In Leak Detection
5,975,712
Telescopic Illuminating Tool
Nov. 2, 1999
6,200,134 B1
Apparatus And Method For Curing
Mar. 13, 2001
Materials With Radiation
6,355,935 B1
Portable Light Source And System For
Mar. 12, 2002
Use In Leak Detection
6,491,408 B1
Pen-Size LED Inspection Lamp For
Dec. 10, 2002
Detection Of Fluorescent Material
One of the challenges facing the design of such light source devices is associated with the necessity to direct the light into a restricted area or space. For example, when a mechanic is attempting to repair a vehicle engine and desires to examine somewhat inaccessible portions of an engine or ancillary equipment attached to the engine in order to locate a fluid leak source, the mechanic will need to carefully direct an ultraviolet or infrared light beam. A typical flashlight construction beam may not be easily directed. Additionally, many prior art light constructions are bulky and not easy to manipulate.
Thus, there has developed a need to provide a flashlight construction which utilizes an easily directed light emitting diode light source. Such a construction should preferably rely upon long life, low current batteries of sufficient voltage for a light emitting diode that will produce a highly visible or highly intense beam of light.
SUMMARY OF THE INVENTION
Briefly, the present invention comprises a light emitting diode (LED) light source flashlight construction incorporated in a pen-sized, unitary, plastic housing. The housing is comprised of an elongate, hollow tubular section connected to a disc shaped battery chamber. Internal wiring connects from the battery chamber through the hollow tubular section to a light emitting diode mounted at the end of the hollow tubular section. The circuit is closed whenever a conductive pocket clip affixed externally to the housing is elastically deformed. The flashlight construction utilizes disk shaped, lithium batteries retained in the battery chamber and which produce an adequate voltage to activate a light emitting diode light source to provide an intense, focused beam of light.
Thus, it is an object of the invention to provide an improved light emitting diode (LED) flashlight construction.
A further object of the invention is to provide a flashlight construction which may be utilized with a light emitting diode or with other light sources such as an incandescent bulb.
Yet another object of the invention is to provide a flashlight construction which is compact, yet rugged and easy to use and store when not in use.
Another object of the invention is to provide a flashlight construction which may be utilized in combination with ultraviolet as well as infrared and white light, light emitting diodes.
Another object of the invention is to provide an inexpensive, yet highly reliable, long life flashlight construction.
These and other objects, advantages and features of the invention will be set forth in the detailed description which follows.
BRIEF DESCRITION OF THE DRAWING
In the detailed description which follows, reference will be made to the drawing comprised of the following figures:
FIG. 1 is an isometric view of the flashlight construction of the invention;
FIG. 2 is a top plan view of the construction of FIG. 1 ;
FIG. 2A is a cross sectional view taken along the line 2 A— 2 A in FIG. 2 ;
FIG. 2B is an inside plan view of the battery cover for the housing of the battery in the chamber section of the light construction;
FIG. 2C is a side view of FIG. 2B ;
FIG. 2D is an outside plan view of the cover of FIG. 2B ;
FIG. 3 is a side elevation of the construction of FIG. 2 ;
FIG. 4 is an end view of the construction of FIG. 3 ;
FIG. 5 is a top plan view of the half of the housing utilized in the flashlight construction of the invention;
FIG. 6 is a side elevation of FIG. 5 ;
FIG. 6A is an end view of the housing section of FIG. 6 ;
FIG. 7 is a bottom elevation of the construction of FIG. 5 ;
FIG. 8 is a plan view of the bottom portion of the housing of the flashlight construction;
FIG. 9 is a side elevation of FIG. 8 ;
FIG. 9A is an end view of the housing section of FIG. 9 ;
FIG. 10 is a plan view of the inside of the housing of FIG. 8 ;
FIG. 11 is the circuit subassembly incorporated in the flashlight construction of the invention; and
FIG. 12 is a an exploded isometric view of the flashlight construction of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
General Overview:
Referring to the figures, the flashlight construction of the invention is comprised of three molded plastic component parts; namely, an upper or outside or top housing or housing section 10 depicted in FIGS. 5 , 6 , 6 A and 7 ; a generally mirror image bottom or inside or lower housing or housing section 12 depicted in FIGS. 8 , 9 , 9 A and 10 and a molded battery cover 14 for the battery chamber section of the joined housings 10 , 12 depicted in greater detail in FIGS. 2B , 2 C and 2 D. The flashlight construction further includes a flexible, elastic, conductive metal clip 16 attached to the outside surface of housing section 10 and projecting through the outer housing section 10 to provide for controlled closure of an electric, direct current series circuit. Contained within the joined housings 10 , 12 is a direct current circuit assembly depicted in FIG. 11 including a light emitting diode 20 connected with an insulated cathode wire 22 . The cathode wire 22 , in turn, is connected with a conductive metal biasing member 24 in contact with series arranged, disc shaped batteries 32 , 34 . The light emitting diode 20 is further connected with a lead wire anode 26 that is insulated but electrically connected from LED 20 to a cylindrical, conductive metal contact 28 . Contact 28 is positioned within the housings 10 , 12 for engagement by flexed clip 16 through a passage 17 in housing 10 . The circuit assembly of FIG. 11 is retained within the housings 10 and 12 for cooperative action with first and second lithium disc shaped batteries 32 and 34 as well as the metal clip 16 .
Thus, the overall construction of the flashlight comprises joinder of the upper or outside housing 10 with the lower or bottom housing 12 to encapsulate the batteries 32 , 34 as well as the circuit assembly of FIG. 11 . The battery cover 14 retains batteries 32 and 34 within a cylindrical battery chamber section 13 defined by the coupled housings 10 and 12 . The metal clip 16 includes prongs 16 A which serve the dual function of attachment of the clip 16 to the housing 10 and to provide an electrical conductive path to one of the poles of the disc shaped batteries 32 , 34 which are arranged in stacked, series in the chamber section 13 of the coupled housings 10 , 12 . The metal clip 16 is normally biased so that it does not engage with the cylindrical metal conductor member 28 . However, manual engagement of the metal clip 16 will flex and close the circuit through the cylindrical metal section 28 thereby closing the circuit through the batteries 32 , 34 and providing electrical current of adequate voltage to the light emitting diode 20 positioned within the coupled housings 10 , 12 .
Housing Construction:
The coupled housings 10 , 12 include a longitudinal, centerline axis 15 which is an axis of symmetry. The longitudinal length of the housings 10 , 12 in the direction of the axis 15 is in the range of 4-6 inches in the preferred embodiment. The lateral side-to-side dimension of the housings 10 , 12 is in the range of ¾ to 1½ inches. The thickness or transverse dimension of the assembled light construction is in the range of ¼ to ½ inches. As a consequence, the entire assembly may be easily retained within the pocket of a user for ease of access and ease of storage. The conductive metal clip 16 retains the item in a pocket. As a result, the flashlight construction is extremely easy to access.
In the preferred embodiment, the light construction utilizes two 2016 coin cell lithium 3-volt batteries in series. Any of a number of light emitting diodes having various wavelength characteristics may be utilized. For example, an infrared, ultraviolet or white light, light emitting diode may be utilized in the flashlight construction. An incandescent bulb may be utilized. Further, it is possible to color code the molded plastic housings 10 and 12 , for example to indicate the wavelength of the light emitting diode. For example, for an ultraviolet flashlight construction, the plastic housing may be molded from a blue plastic material, for example, an ABS plastic material. For an infrared flashlight construction, the molded plastic components may be manufactured from a red ABS plastic material. Other colors may be utilized. However, the color coding system facilitates the functionality of the flashlight construction enabling the user to immediately understand the capability of the flashlight in terms of the wavelength associated with the light emitting diode (LED).
Referring to FIGS. 2B , 2 C, 2 D, 5 , 6 , 7 , 6 A, 8 , 9 , 9 A and 10 , there is depicted in greater detail the construction of the component plastic parts which are used to construct the light emitting diode flashlight construction. Referring first to FIGS. 5 , 6 , 6 A and 7 , there is depicted the top or outer housing 10 . The top or outer housing 10 is symmetric about the longitudinal axis 15 and includes a semi-tubular section 11 connected to an upper chamber section 13 . The semi-tubular section 11 comprises a hollow semi-cylindrical section having a longitudinal passage 17 formed therein for cooperation with the cylindrical, conductive member 28 and the LED 20 . The chamber section 13 is formed so as to receive the disc shaped batteries 32 , 34 . The chamber section 13 further includes parallel slits 19 and 21 for receipt of conductive attachment prongs 16 A of the metal clip 16 . The conductive metal prongs 16 A fit through the slits 19 and 21 for engagement with one of the conductive poles; namely, the anode pole of a disc battery 32 or 34 within the cylindrical chamber 13 . The outer housing 10 semi-tubular section 11 further includes first and second radially projecting prongs or tabs 23 and 25 which are cooperative with and engage with radial receptors or receptacles associated with the bottom housing 12 . In this manner, the housing sections 10 and 12 may be aligned or joined or retained together by ultrasonic welding, for example.
Within the tube section 11 are various transverse wall sections. Thus, a first wall section 31 is positioned on one side of the slot 17 . A second wall section 33 is positioned on the other side of slot 17 . The wall sections 31 , 33 cooperate with the cylindrical conductive member 28 to hold member 28 in position aligned with the tubular passage 17 . Spaced third and fourth transverse wall sections 35 and 37 at the outer end of the tube section 11 cooperate with a peripheral rib 39 in FIG. 11 of the light emitting diode 20 to retain the light emitting diode in position within the tube 11 .
FIGS. 8 , 9 , 9 A and 10 depict the bottom or inside housing 12 . The bottom or inside housing 12 is, in general, a mirror image of the outer housing 10 . The bottom housing 12 thus includes a semi-tubular section 11 A and chamber section 13 A. The chamber section 13 A, however, is open and includes a notched periphery 13 B for receipt of battery cover 14 having compatible notches and teeth. The battery cover 14 is depicted in FIGS. 2B , 2 C and 2 D and comprises a molded flat plastic member with radially projecting teeth 60 that cooperate with notches 62 in periphery 13 B. The inside face of the battery cover 14 includes a central rib 64 that provides for molding a slot or recess in the outside of cover 14 . The outside of the cover 14 includes slot 66 in FIG. 2D which can receive a coin or some other item to effect turning and locking of the cover 14 in position within the notches 62 of the bottom housing 12 .
Referring again to FIGS. 8 , 9 , 9 A and 10 , the bottom housing 12 also includes transverse walls or wall sections 70 and 72 cooperative with the external rib 39 on the light emitting diode 20 . The bottom section 12 further includes, on the inside thereof, receptacles 74 and 76 for cooperation respectively with the projecting tabs 23 and 25 of the top housing 10 so that the component housings 10 , 12 may be aligned for joinder by adhesive, or sonic welding, or other means. Further, the interior of the bottom section 12 includes a longitudinal rib 28 A that serves as a key to engage and retain the conductive member 28 by fitting into a longitudinal slot 28 B in the member 28 .
Referring to FIG. 12 , the battery chamber or battery section 13 A of the housings 10 , 12 comprises a generally cylindrical chamber having a cylindrical axis 11 B that is transverse to the longitudinal axis 15 . The longitudinal axis 15 thus comprises a cylindrical axis for the tubular section 11 of the housings. Axis 11 B defines a cylindrical axis for the chamber section 13 B. The axes 11 B and 15 are generally normal to each other.
The cross sectional configuration of the tubular section is generally cylindrical but may be polygonal or comprise other shapes. Likewise, the battery chamber may have various shapes or configurations other than cylindrical.
Thus, it is possible to vary the shape and arrangement of the various component parts comprising the flashlight construction without departing from the spirit and scope of the invention. The invention, therefore, is limited only by the following claims and equivalents thereof. | An LED flashlight construction is formed from molded plastic housing members joined to provide a tubular section connected to a battery chamber capable of holding one or more disc batteries capable of providing adequate voltage for operating a light emitting diode positioned at the distal end of the tubular section. A conductive metal pocket clip may be elastically deformed for closure of the circuit to provide power to the light emitting diode. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation application of our commonly assigned, copending U.S. application Ser. No. 06/226,200, filed Jan. 19, 1981, now abandoned and entitled "Filter or Wire Machine".
BACKGROUND OF THE INVENTION
The present invention broadly relates to the papermaking art and, in particular, concerns a new and improved method of, and filter or wire machine for washing stock suspensions, which contains an endless revolving wire or filter band to which there is infed, in the form of a stock suspension, the material which is to be washed.
During the treatment of aqueous fiber stock suspensions obtained from waste paper there are employed wire or filter devices--sometimes also referred to as screening or sieve devices--by means of which the fiber stock suspension is thickened. During an operating procedure, generally referred to as washing, there are thus removed from the stock suspension fine materials or fines such as, for instance, ash or cinder materials, broken fiber pieces and so forth. The known wire or filtering devices, for instance inclined wires or filters, curved wires, drum thickeners and so forth, as a washing assembly possess the drawback that their degree of washing or cleaning is extremely limited, and therefore, there are required a number of washing stages with related intermediate thinning of the stock suspension. Additionally, they have a faulty operational reliability since, in particular, the inclined wire and the curved wire are extremely prone to clogging. As a rule, the heretofore known wire or filter devices containing a multi-stage construction require a large amount of space and are accordingly complicated and cumbersome to fabricate and operate.
U.S. Pat. No. 3,616,660, granted Nov. 2, 1971 discloses an apparatus for washing fibrous material which contains a rotatable drum having a perforated shell constituted by a perforated body covered with a foraminous wire. The shell is permeable to liquids but substantially impermeable to the fibrous material undergoing treatment. A foraminous belt, in the form of a wire mesh, is looped around the drum surface and moves conjointly therewith. At a point near to where this belt is lead to the drum surface there is provided a curved plate defining in conjunction with the drum surface a web-forming zone. A rigid liquid-pervious member, again for instance a perforated plate, extends from a point adjacent to the end of the curved plate over another portion of the drum surface, and is formed and positioned relative to the drum surface to define a separate washing zone. Such construction of washing apparatus is extremely complicated and requires specially designed components for forming the same. Moreover, the perforated drum is prone to clog, and the lower portion of the drum collects liquid removed from the fibrous material which undesirably can be then reintroduced back into the incoming suspension of fibrous material, thereby rendering more difficult the dewatering and washing of the fibrous material. Also the design is laid out such that the washing liquid must be introduced at a separate location into the washing zone which follows the web-forming zone. At the outlet end of the equipment there is removed the processed web.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind it is a primary object of the present invention to provide a new and improved method of, and wire machine for washing a stock suspension which is not associated with the aforementioned drawbacks and limitations of the prior art constructions.
Another and more specific object of the present invention aims at providing a new and improved construction of wire machine which is intended to accomplish the aforementioned purposes, requires very little space and possesses a good dewatering capacity and independent thereof a good cleaning or washing action with high operational reliability of the equipment.
Still a further significant object of the present invention aims at providing a new and improved construction of a wire or filter machine for use in paper fabrication, which machine is relatively simple in construction and design, quite economical to manufacture, extremely reliable in operation, requires very little maintenance and servicing, and has modest space requirements.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the wire or filter machine of the present development is manifested by the features that there is provided a cylinder or cylinder member about a portion of whose circumference there is trained or wrapped a wire or filter band or equivalent structure. An infeed device serves for forming a substantially flat jet of the stock suspension which is directed into a substantially wedge-shaped intermediate space between the cylinder and the wire band which travels thereon. Also, there is provided a removal device for the removal of the solid constituents of the stock suspension from the cylinder and the wire, respectively, the solid constituents remaining between the cylinder and the wire.
In certain of its more specific aspects the rotatable cylinder is advantageously constituted by a solid cylinder, thereby eliminating any danger of clogging perforations or the like as would otherwise arise when using a perforated cylinder. Equally, the liquid extracted from the stock suspension cannot pass into the interior of the solid cylinder where it would be difficult to remove and possibly also could again come into undesirable contact with the stock suspension. The wire is trained and tensioned against the surface of the solid cylinder throughout the major part of the web forming region defined between the run-on and lift-off location of the wire with respect to the solid cylinder. The infeed device for forming the substantially flat jet of the stock suspension contains the washing liquid, so that the web-forming portion or zone also simultaneously constitutes the actual washing zone for washing the stock suspension. The web formed between the wire and the solid cylinder is intentionally destroyed upon its discharge from the equipment.
In the U.S. Pat. No. 3,056,719, granted Oct. 2, 1962, there is disclosed to the art a papermaking machine which contains a cylinder about a portion of whose circumference there is wrapped a wire or filter band. The liquid stock or stock suspension is infed by means of a headbox in the form of a flat jet into a wedge-shaped intermediate space between the cylinder and the wire band which travels thereon. With this machine the formed fiber fleece or web remains at the wire and is dried and processed into paper. Due to the difficulties associated with the detachment of the fiber web from the cylinder, which must possess a solid smooth surface, it has not heretofore been possible to put into actual practice this relatively simple papermaking machine.
On the other hand, with the inventive wire machine and method of washing stock suspensions, the fiber web formed between the cylinder and the wire, following its dewatering, is intentionally destroyed and is further processed in the form of a collected thickened suspension. Therefore it is unimportant whether it remains adhering to the cylinder or the wire after its passage through the wrap angle of the wire at the cylinder.
By virtue of the invention there is obtained a novel construction of machine and method of operating the same for washing suspensions of fibrous materials which makes use of a basically known principle, and particularly utilizes its advantages while overcoming the drawbacks of the prior art machine which heretofore precluded adaptation of such prior art equipment into practical applications.
Although in the first instance the inventive machine is used for dewatering and washing an aqueous fiber stock suspension obtained from waste paper, it generally also can be employed for filtering other materials which are infed in the form of a suspension in a liquid.
Preferably, the run-on or contact line of the wire at the cylinder can be located angularly offset at the region of the apex location of the cylinder, and specifically, viewed opposite to the direction of rotation of the cylinder, through an angle which is smaller than 45°, and the run-off or lift-off location or line of the wire from the cylinder can be arranged at the region of the lower cylinder half, and specifically, forwardly of the lowest position of the cylinder viewed in its direction of rotation. Due to these measures it is possible, with a large wrap angle of the filter or wire band at the cylinder, which can amount to preferably 140° to 180°, to obtain a faultless removal of the obtained good stock from the cylinder and from the wire, augmented by the action of the force of gravity. However, it should be understood that it is conceivable to employ also other angular orientations or positions of the run-on line and the run-off line.
Additionally, the cylinder can be equipped with at least one contact or pressing roll for pressing the wire against its cylinder surface. In this way there is realized a so-called register roll effect which further augments or enhances the dewatering of the material through the action of a pressure pulse and the formation of a suction action following the pressure location of the contact or pressing roll.
The dewatering of the material remaining upon the wire or filter following the run-off location can thus be further augmented in that the wire at the region of the run-off or lift-off location from the cylinder, viewed in the direction of movement of such wire, is equipped with at least one dewatering element.
Preferably, the cylinder can have operatively associated therewith a catch or receiving container which has at least two compartments or chambers which are operatively associated with different portions of the wrap angle of the wire at the cylinder. The water which is sprayed by the wire at different portions or sections contains different contaminants and in different densities, so that the waste water effluxing from such chambers can be differently treated.
Moreover, the catch container can be provided with a perforated partition or separation wall which is pervious for the water. Due to this measure it is possible to undertake, under the action of the kinetic energy of the water, precleaning of such water and, on the one hand, the water which effluxes through the partition wall is partially cleaned and, on the other hand, the eliminated contaminants remaining forwardly of the wire are concentrated.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawing wherein the single FIGURE schematically illustrates an exemplary embodiment of wire or filter machine according to the invention and useful for practising the method aspects of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Describing now the drawing, the exemplary embodiment of wire or filter machine shown in the single figure thereof will be seen to contain a wire or filter 1 having the form of an endless band. This wire 1 is guided over guide rolls 2, 3 and 4, a take-off roll 5, a drive roll 6 and a rotatable cylinder or cylinder member 7. The wire band or wire 1 travels onto the cylinder 7 at a substantially line-shaped run-on location A and travels off of the cylinder 7 at a run-off line or location B.
As will be seen by referring to the drawing, the run-on location A is spaced from the apex portion or location S of the cylinder 7 through an angle α, and specifically opposite to the rotational direction of the cylinder 7 which has been indicated by the arrow P, this cylinder 7 co-rotating with the wire 1.
The run-off or lift-off location B of the wire 1 from the cylinder 7 is located at the region of the lower cylinder half, and specifically, viewed in the direction of rotation of the cylinder 7, before its lowest position or location T.
As will be further seen by inspecting the single figure of the drawing, the inventive wire machine is provided with a flat jet nozzle 8 which is connected with a suitable tubular conduit or line 10 through which there is infed to the wire machine the material which is to be sieved or filtered, normally an aqueous fiber stock suspension which is obtained from waste paper and which contains any washing liquid which might be used. The nozzle or nozzle means 8 forms a flat suspension jet 11 which is introduced and directed into a substantially wedge-shaped intermediate space 12 between the wire 1 and the cylinder 7.
At the region of the wrap angle W of the wire 1 at the cylinder 7 there is arranged at the solid cylinder 7 a catch container or receiver C having two chambers 13 and 14 for the pressed-out water which contains the expressed or separated-out contaminants. At the region of the chamber 14 there is operatively associated with the cylinder 7 a press or contact roll 15. The catch container C is provided with a dewatering element such as suction ledge 16, here shown as a foil, but another equivalent device can be used, following which the wire 1 is moved over a scraper edge or scraper 18 of the catch container C.
As will also be clearly recognized by inspecting the single figure of the drawing, the cylinder 7 and the take-off roll 5 are provided with scrapers 17 or equivalent structure which ensure that the material respectively adhering at the cylinder 7 and remaining at the wire band 1 and pressed and removed by the take-off roll 5 is detached from such cylinder 7 and take-off roll 5 and drops into a collecting container 20 from which such removed material can be delivered for further processing.
Between the rolls 5 and 4 there is located a cleaning device 21 which, for instance, can contain spray nozzles, scrapers and so forth, and serves for the cleaning of the wire 1 before the related wire section again arrives at the region of the nozzle 8.
The flat jet nozzle 8 forms from the stock suspension a substantially flat material jet which is directed between the cylinder 7 having the smooth cylinder surface and the wire 1.
The infed stock suspension thereafter is dewatered by the wire tension at the region of the wrap angle W, and the separated-out water together with the contaminants drops into the chambers 13 and 14. The wire 1 is tensioned against the surface of the solid cylinder 7 at least throughout the major part of the web forming zone located between the wire run-on location A and the wire run-off location B and which zone also defines the washing zone. Two chambers 13 and 14 are provided so that the waste water emanating from two regions or zones, which can contain different properties, can be separately processed. Thus, for instance, the waste water from the chamber 14 might have less contaminants than the waste water effluxing out of the chamber 13.
During a typical washing operation, during which an aqueous fiber stock suspension obtained from waste paper is cleaned of the aforementioned contaminants, such as for instance mineral pigments, printing inks, pieces of broken fibers and so forth, the stock suspension to be cleaned or washed is infed through the tubular conduit 10 at a consistency of less than 1.5%, preferably 0.4 to 0.8%.
The wire machine can be preferably operated during the washing operation such that the fiber web or the like formed between the cylinder 7 and the wire 1 has a weight of less than 100 grams per square meter, preferably 30 to 70 grams per square meter. The wire speed and the circumferential speed of the cylinder 7 can be in the order of about 400 to 1,200 meters per minute. The wrap angle W of the wire 1 about the cylinder 7, that is to say, the angular spacing of the points A and B from one another, preferably can be in the order of 140° to 180°.
The fiber web or fleece which is formed between the wire 1 and the cylinder 7 has a stock density of 5 to 8% and, as already mentioned, during the removal from the cylinder 7 and the wire 1 as a fiber web or fleece is disintegrated or destroyed and then is delivered as a thickened suspension from the collecting container 20 for undergoing a further suitable processing operation.
The contact or press roll 15, during the washing operation, augments the dewatering of the fiber web formed between the wire 1 and the cylinder 7 due to the so-called register roll effect. After the contact or press location of the roll 15 there is formed a so-called suction action, so that the free water which is located still in the fiber web and at the wire adheres to the surface of the roll 15. In this way there is further augmented the dewatering operation.
The action of the roll 15, during the washing operation, can be further improved through the provision of a water jet nozzle 22 which, in accordance with the illustration of the drawing, and viewed with respect to the direction of movement of the wire 1, is located forwardly of the contact or press roll 15. By providing an exactly dimensioned jet of water it is namely possible to flush the fiber material located between the wire 1 and the cylinder 7 and to loosen such fiber material, whereupon there can be accomplished a further dewatering operation by the contact or press roll 15.
Due to the suction ledge 16 which is arranged after the contact roll 15 there is augmented dewatering of the fiber material which remains at the wire 1.
The inventive wire machine is not only suitable for washing fiber material obtained from waste paper, but also can be used for simple thickening of fiber material. In such case the contact or press roll 15 together with the nozzle 22 and also the suction ledge 16 need no longer be used.
However, it should be understood that, on the other hand, there also can be provided more than one contact or press roll 15 or suction ledge 16.
As also will be evident by reverting again to the drawing, the chamber or compartment 13 is subdivided by a wire or filter 23 or equivalent structure into two partial chambers which can have special outflow or withdrawal lines. As indicated by the broken arrows, the water which has been propelled from the cylinder 7 can penetrate through the wire or filter 23 into the right-hand portion of the chamber 13, whereas solid particles entrained by the water can remain at the left-hand portion of the chamber 13. Consequently, there is rendered possible a certain pre-cleaning of the water with the aid of its kinetic energy.
As far as the spray nozzles 22 are concerned, which also can be provided in a number of rows, such can be arranged at a random location of the wrap angle W of the cylinder 7 by the wire or filter 1. A preferred arrangement, as illustrated, contemplates providing the spray nozzles 22 at a location where there has already been accomplished a partial dewatering of the fiber material, and a further dewatering follows, in the present embodiment under discussion, augmented by the action of the contact roll or cylinder 15. Due to the action of the water jets, as mentioned, there is beneficially accomplished a flushing and loosening of the already partially pressed-out fiber material, something which improves the washing operation.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. Accordingly, | A method of, and wire machine for, washing stock suspensions is disclosed wherein a cylinder having a solid smooth surface is encircled along a portion of its circumference by an endless wire or filter band. The stock suspension which is to be dewatered is infed between the solid cylinder and the wire by means of a flat jet nozzle. After throughflow of the stock suspension between the cylinder and the wire the dewatered fiber material is removed from the wire and the cylinder, respectively, collected in a collecting container and delivered for further processing. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates to an exhaust gas treatment filter for an engine generator, and in particular, to a system that removes particulate matter (PM) generated by operation of a diesel engine for a generator and accumulated in a Diesel Particulate Filter (DPF) to recover the DPF,
RELATED ART
[0002] A diesel engine generates particulate matter in addition to NOx as a result of fuel combustion in nature. To prevent the particulate matter from being emitted into the atmosphere, an increasing number of diesel engines are equipped with a DPF to collect particulate matter (PM) contained in exhaust gas. This also applies to engine-driven generators.
[0003] In an engine-driven generator equipped with a DPF, a generator G is driven by a diesel engine E, electric power is supplied to a load (not shown in the drawings) through an output terminal OUT, and exhaust gas from the diesel engine E is emitted into the atmosphere through the DPF, as shown in FIG. 5 .
[0004] However, the DPF is limited in terms of the amount of PM collected, and thus, once a certain amount of particulate matter is accumulated, the particulate matter needs to be removed by, for example, being burned by a certain method, to recover the DPF. For recovery of the DPF, the amount of the particulate matter and the temperature of the exhaust gas are measured and the engine E is controlled to burn the particulate matter.
[0005] That is, particulate matter amount measuring device PMD provided in the DPF measures the amount of the particulate matter, and temperature detecting device TD measures the exhaust gas temperature. Based on the results of measurements by the measuring device, an engine control unit ECU transmits and receives signals to and from the engine E to control the engine E. Thus, the particulate matter is burned in a timely manner to recover the DPF.
[0006] Furthermore, another method for recovering the DPF is to burn the particulate matter using an electric heater incorporated in the DPF (see Japanese Patent Laid-Open No. 2009-216075).
[0007] The recovery of the DPF as described above allows an engine generator using a diesel engine to be continuously operated. A failure to appropriately recover the DPF causes a large amount of particulate matter to be accumulated, This leads to a very disadvantageous situation that involves the shutdown of the generator and manual removal of the particulate matter in the DPF.
[0008] To recover the DPF, in other words, to burn the particulate matter, the exhaust gas needs to be hot above a certain temperature. In this case, what should be taken into account is that the installed engine generator typically has a capacity about three times as large as a rated input power for a load so as to be able to deal with, for example, starting of an electric motor when a large starting current flows rapidly.
[0009] Thus, in a steady state, the engine is operated under a light load, and the exhaust gas temperature remains low. Since the generator serves as a load on the engine, the engine is to be operated at a constant speed. Consequently, such method of increasing the speed in order to raise the exhaust gas temperature as is the case with automobiles cannot be adopted.
[0010] Therefore, the recovery of the DPF in the engine generator may involve a technique for burning the particulate matter using such a heater as illustrated in Japanese Patent Laid-Open No. 2009-216075.
[0011] However, providing a heater in order to burn the particulate matter is not always satisfactory from the viewpoint of fuel efficiency. Furthermore, a special DPF incorporating the heater is not preferable. Instead of the special DPF, a general-purpose DPF (for example, a DPF for automobiles) is desirably used, but adopting the general-purpose DPF for the engine generator is inappropriate as described above.
[0012] With the foregoing in view, it is an object of the present invention to provide a DPF system for an engine generator which prevents particulate matter from being accumulated without stopping power supply and which allows the DPF to be recovered in a fuel efficient manner.
SUMMARY OF THE INVENTION
[0013] To accomplish this object, the present invention provides:
[0014] A DPF system for an engine generator that carries out a recovery process on a filter (DPF) provided to remove particulate matter generated by combustion of fuel for an engine when an amount of the particulate matter attached to the DPF exceeds a predetermined value, the engine generator carrying out the recovery process by performing an automatic recovery operation to raise a temperature of exhaust gas from the engine to burn the particulate matter, the DPF system comprising:
[0015] a dummy load connected to the engine generator when necessary; and
[0016] control device for allowing the engine to perform an automatic recovery preparation operation in such a manner that, once the amount of the particulate matter exceeds the predetermined value, the automatic recovery operation is performed when the temperature of exhaust gas reaches an automatic recovery reference temperature, and the dummy load is connected to the generator to raise the temperature of exhaust gas when the temperature of exhaust gas does not reach the automatic recovery reference temperature.
[0017] As described above, according to the present invention, when the amount of particulate matter in the engine increases, the dummy load is connected to the generator based on the exhaust gas temperature to raise the exhaust gas temperature. Thus, the particulate matter is burned to recover the DPF. This prevents an excessive amount of particulate matter from being accumulated and furthermore allows provision of a DPF system for an engine generator which has high fuel efficiency. As a result, the engine generator can be operated without bringing about a situation in which power supply is stopped and in which the DPF is then recovered.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a block diagram showing a configuration of a DPF system for an engine generator according to the present invention;
[0019] FIG. 2 is a diagram illustrating a configuration of a DPF installed in the engine generator;
[0020] FIG. 3 is a flowchart showing a basic control operation for recovery of the DPF in the engine generator;
[0021] FIG. 4 is a flowchart showing a DPF recovery control operation according to an embodiment of the present invention; and
[0022] FIG. 5 is a block diagram showing a configuration of a DPF system in a conventional engine generator.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Embodiments of the present invention will be described with reference to the accompanying drawings as follows.
Embodiment 1
[0024] FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention. As shown in FIG. 1 , a generator G includes a dummy load L and a contactor MC both provided on an output side of the generator G; the contactor MC applies the dummy load L on the generator G and removes the dummy load L. The contactor MC is turned on and off to connect the dummy load L such as a resistor to the generator G when necessary. The generator G is then operated to increase power output from the engine E.
[0025] Based on results of measurements by particulate matter amount measuring device PMD and temperature measuring device TD, the contactor MC is controlled by an engine controlling additional unit G-ECU connected to an engine control unit ECU via a CAN (Controller Area Network). That is, the engine controlling additional unit G-ECU turns the contactor MC on and off in accordance with engine control performed by the engine control unit ECU to controllably apply the dummy load L on the generator G and cuts off the dummy load L.
[0026] That is, when necessary, the dummy load L is connected to the generator G to increase the power output from the engine E to raise the temperature of exhaust gas. Thus, particulate matter in a DPF is burned and removed to recover the DPF.
[0027] In this case, the engine control unit ECU is, for example, a control apparatus attached to an automobile diesel engine E. The engine controlling additional unit G-ECU is a control apparatus added in order to control the contactor MC so as to apply the dummy load L to the engine E and to cut off the dummy load in accordance with operation of the engine E.
[0028] FIG. 2 illustrates the structure of the DPF. The DPF in a broad sense consists of an oxidation catalyst DOC and a DPF main body that is the DPF in a narrow sense. The DOC and the DPF main body integrally operate to treat exhaust gas IN to generate exhaust gas OUT. Then, the particulate matter amount measuring device PMD detects the amount of particulate matter based on, for example, a difference in pressure between an input and an output of the DPF.
[0029] FIG. 3 is a flowchart showing a basic operation of DPF recovery control in the engine generator shown in FIG. 5 , that is, the operation corresponding to a prerequisite for the present invention. With reference to FIG. 3 , description will be provided which relates to a normal operation and a DPF recovery operation of an engine generator equipped with a DPF system.
“Normal Operation and DPF Recovery Operation of the Engine Generator Equipped with the DPF System”
[0030] First, an operator performs manual operations of starting the engine E (S 1 ), setting the engine E to rotate at a rated speed (S 2 ), and applying a load on the generator G (S 3 ). Thereby, the engine generator performs a normal operation (S 4 ).
[0031] As the engine E is operated, particulate matter is generated in exhaust gas and gradually accumulated in the DPF (S 5 ). At this time, when the exhaust gas temperature in the engine E is equal to or higher than a DPF recoverable temperature at which the DPF can be recovered, in other words, the temperature at which the particulate matter is burned (S 6 ), the particulate matter in the DPF is spontaneously burned (S 7 ). In other words, the DPF is spontaneously recovered while the engine E continues the normal operation.
[0032] On the other hand, when the exhaust gas temperature is lower than the DPF recoverable temperature, the process proceeds to step S 8 to determine whether or not the PM amount is equal to or more than an automatic recovery reference amount. When the PM amount is less than the automatic recovery reference amount, the process returns to step S 4 where the engine E continues the normal operation.
[0033] When it is determined in step S 8 that the accumulated PM amount is equal to or more than the reference amount, that is, the PM amount indicates that the DPF is to be recovered, the process proceeds to step S 9 to start automatic recovery if the exhaust gas temperature is equal to or higher than the automatic recovery reference temperature (S 10 ).
[0034] In this case, the automatic recovery reference temperature refers to a temperature equal to a recoverable temperature minus a temperature to which the exhaust gas temperature can be raised by controlling the engine to the extent that the generator can be used in a manner equivalent to the manner during the normal operation.
[0035] In the automatic recovery operation, the engine E is controlled by the engine control unit ECU to the extent that the generator G can be used in a manner similar to the manner during the normal operation, based on the amount of particulate matter (PM amount) measured by the particulate matter amount measuring device PMD provided in the engine E and on the exhaust gas temperature measured by the temperature measuring device TD also provided in the engine E.
[0036] Then, the process proceeds to step S 11 where the engine E is controlled to burn the particulate matter in the DPF (automatic recovery). The engine control includes post injection (fuel injection during piston exhaust) intake restriction and the like. During the automatic recovery, the engine E is controlled to the extent that the generator can be used in a manner equivalent to the manner during the normal operation.
[0037] The process continues the automatic recovery until the PM amount decreases to an automatic recovery end reference amount, while checking whether or not the exhaust gas temperature is equal to or higher than the automatic recovery reference temperature (S 11 →S 12 →S 13 →S 11 → . . . ). When, by the automatic recovery, the PM amount decreases below the automatic recovery end reference amount, the automatic recovery ends and the engine E returns to the normal operation (S 15 →S 4 ).
[0038] On the other hand, during an automatic recovery operation, the load may decrease to lower the exhaust gas temperature below the automatic recovery reference temperature. At this time, in other words, when the exhaust gas temperature falls below the automatic recovery reference temperature though the PM amount has not decreased to the automatic recovery end reference (S 13 ), the process suspends the automatic recovery (S 14 ) and proceeds to step S 16 to determine whether or not the PM amount is equal to or more than the reference amount at which manual recovery is to be carried out.
[0039] When the PM amount is less than the reference amount at which the manual recovery is to be carried out, the process returns to step S 4 where the engine E is operated in a normal manner. However, when the PM amount is equal to or more than the manual recovery reference, the process proceeds to step S 17 to issue a manual recovery request. When the manual recovery request is issued, the process proceeds to step S 18 where the operator performs determination and needed manual operations.
[0040] The manual recovery is the last DPF recovery that can be carried out by the engine control, and the manual recovery reference for the PM amount is close to a limit amount at which the DPF can be safely recovered. For the manual recovery, the power output, the rotation speed, and the like need to be adjusted and controlled up to a larger region exceeding the range of the engine control for the automatic control.
[0041] This may preclude the generator from performing a normal operation, and thus, power supply needs to be stopped. However, sudden power outage is risky, and the operator's determination and manual operations are involved in the process in order to stop power supply with the usage of the load, the progress of the operation, and the like taken into account. The recovery in this stage is referred to as the “manual recovery”, but the recovery operation itself is automatically performed by the engine control apparatus ECU.
[0042] First, in step S 18 , the operator determines whether or not to accept the manual recovery request. If the operator accepts the manual recovery request, the process is manually continued to step S 19 where the load on the generator G is cut off, with the engine E kept in an idling state. Then, the operator depresses a manual recovery button (switch) (S 20 ).
[0043] Thus, a manual recovery operation is started (S 21 ), and the engine E is controlled to burn the particulate matter (S 22 ). The control is performed until the PM amount decreases down to the manual recovery end reference amount (S 23 ). The control ends when the PM amount reaches the manual recovery end reference amount (S 24 ). The process then returns to step S 2 .
[0044] On the other hand, when the operator determines not to accept the manual recovery request or overlooks the manual recovery request, the process proceeds to step S 25 where the engine control unit ECU determines whether or not the PM amount is equal to or more than an emergency stop reference amount. Then, when the PM amount is less than the emergency stop reference amount, the process proceeds to step S 4 where the engine E is operated in a normal manner. When the PM amount has reached the emergency stop reference amount, the engine E is brought to an emergency stop (S 26 ) because the particulate matter may be subjected to abnormal combustion to cause an accident.
“Automatic Recovery Operation by the DPF System According to the Present Invention”
[0045] FIG. 4 is a flowchart illustrating a recovery operation of the system according to the present invention which operation is to be inserted between steps S 8 and S 17 in FIG. 3 instead of steps S 9 to S 16 with such expressions as found in activity diagrams.
[0046] The flowchart illustrates the contents of an operation by steps S 101 to S 125 , and the description below follows this order of steps.
[0047] First, in step S 8 in the flowchart in FIG. 3 , the process proceeds to step S 101 when the PM amount is equal to or more than the automatic recovery reference amount, Step S 101 determines whether or not the exhaust gas temperature is equal to or higher than the automatic recovery reference temperature. When the exhaust gas temperature is equal to or higher than the reference temperature, the process proceeds to step S 108 to start an automatic recovery operation. When the exhaust gas temperature is lower than the reference temperature, the process proceeds to step S 102 where the dummy load L is applied on the generator.
[0048] When the dummy load L is applied on the generator, the control unit ECU for the engine E controls the engine E to increase the amount of fuel injection to maintain a constant-speed operation. As a result, the exhaust gas temperature rises, but due to a time delay in the rise of the gas temperature, the result of the operation of the control apparatus appears with the time delay. Therefore, step S 103 deals with the time delay using a timer (retention time 1).
[0049] That is, when the retention time 1 elapses, determination is made as to whether or not the exhaust gas temperature is equal to or higher than the automatic recovery reference temperature (S 107 ). When it is determined that the exhaust gas temperature is equal to or higher than the automatic recovery reference temperature, the process proceeds to step S 108 to start the automatic recovery operation in step S 109 and the subsequent steps.
[0050] On the other hand, when the exhaust gas temperature is lower than the automatic recovery reference temperature, the process proceeds to step S 124 where the dummy load L is cut off, and in step S 125 , determination is made as to whether or not the PM amount is equal to or higher than the manual recovery reference amount. When the PM amount is less than the manual recovery reference amount, the process returns to step S 4 where the engine E is operated in a normal manner. When the PM amount is equal to or more than the manual recovery reference amount, the process proceeds to step S 17 to issue a manual recovery request.
[0051] The description of the operation returns to step S 103 . When the load increases rapidly during the set duration for the timer in step 103 (S 104 a ), the process immediately proceeds to step S 105 where the dummy load L is cut off. The process then returns to step S 101 . In this case, the dummy load L is cut off in response to the rapid increase in load in order to provide all of the power supply capability of the engine generator to the load on the assumption that the rapid increase in load is due to, for example, starting of the electric motor. This also applies to a period of an automatic recovery operation described below.
[0052] Furthermore, when the load becomes equal to or more than the reference value during the set duration for the timer (S 104 b ), the process proceeds to step S 106 where the dummy load L is cut off using another timer (retention time 2) (S 105 ). The process then returns to step S 101 . Furthermore, when the load becomes less than the reference value during the set duration for another timer, the process returns to step S 103 with the dummy load L remaining applied on the generator.
“Dummy Load Control During an Automatic Recovery Operation According to the Present Invention”
[0053] When an automatic recovery operation is started in step S 108 as described above, the engine E is controlled to burn the particulate matter (automatic recovery) in step S 109 . The process then proceeds to step S 110 .
[0054] Step S 110 determines whether or not the dummy load L is currently applied on the generator. If the dummy load is currently applied on the generator, when the load increases rapidly (S 111 ) or is equal to or more than the reference value (S 113 ), the dummy load L is cut off in step S 112 .
[0055] Furthermore, when, in step S 113 , the load is less than the reference value, the process proceeds to step S 114 to determine whether or not the PM amount has reached the automatic recovery end reference amount. When the PM amount has reached the automatic recovery end reference amount, the automatic recovery ends (S 118 ). On the other hand, when the PM amount is less than the automatic recovery end reference amount, the process proceeds to step S 121 . Step 121 determines whether or not the exhaust gas temperature is equal to or higher than the automatic recovery reference temperature. When the exhaust gas temperature is equal to or higher than the automatic recovery reference temperature, the process returns to step S 109 to continue the automatic recovery operation.
[0056] If, in step S 110 , the dummy load L has not been applied on the generator, when the load increases rapidly (S 115 ) or is equal to or more than the reference value (S 116 ), the process proceeds to S 114 . Furthermore, when the load is less than the reference value, the dummy load L is applied on the generator (S 117 ) and proceeds to step S 114 to determine whether or not the PM amount meets the automatic recovery end reference.
[0057] When, in step S 114 , the PM amount has reached the automatic recovery end reference amount, the process proceeds to step S 118 to end the automatic recovery and then proceeds to step S 119 to check whether or not the dummy load L has been applied on the generator. When the dummy load L has been applied on the generator, the process proceeds to step S 120 to cut off the dummy load L. When the dummy load L has not been applied on the generator, the process returns to step S 4 where the engine generator is operated in a normal manner.
[0058] On the other hand, when step S 114 determines that the PM amount does not meet the automatic recovery end reference, step S 121 determines whether or not the exhaust gas temperature is equal to or higher than the automatic recovery reference temperature. When the exhaust gas temperature is lower than the automatic recovery reference temperature, the process temporarily suspends the automatic recovery (S 122 ) and proceeds to step S 123 to determine whether or not the dummy load L has been applied on the generator. When the dummy load L has not been applied on the generator, the dummy load L is applied on the generator (S 102 ). When the dummy load has been applied on the generator, (determining the automatic recovery to be no longer effective) the dummy load L is cut off (S 124 ) and proceeds to S 17 via step S 125 to issue a manual recovery request.
[0059] When, in step S 121 , the exhaust gas temperature is equal to or higher than the automatic recovery reference temperature, the process proceeds to step S 109 to continue the automatic recovery. This is followed by the operation in step S 110 and the subsequent steps.
[0060] Now, a technical prerequisite for the present invention is that a state is basically avoided in which, even though the dummy load L is applied on the generator (S 102 ) to increase the load on the engine E, the exhaust gas temperature fails to rise and is lower than the automatic recovery reference. Such a state could only occur when there should have been a very abnormal situation such as an extreme decrease in outside temperature to an unexpected value or a failure in mechanical element.
Embodiment 2
[0061] Embodiment 1 above is described on the premise that the output power voltage from the generator is fixed. However, given that many generators on the markets are switchable between a three-phase 400 V class and a three-phase 200 V class, the dummy load L is desirably made switchable in response to switching of the voltage.
[0062] To achieve this, for example, a voltage detecting relay may be provided in an input section of the dummy load L so as to allow automatic switching of the dummy load L according to the voltage of the generator. In the dummy load L, resistors may be connected to be switchable between a series connection and a parallel connection or between a star connection and a delta connection. When the output power voltage from the generator is high, the connection may be switched to the series connection or the star connection. When the output power voltage from the generator is low, the connection may be switched to the parallel connection or the delta connection.
DESCRIPTION OF SYMBOLS
[0063] E Engine
[0064] G Generator
[0065] DPF Diesel particulate filter
[0066] DOC Oxidation catalyst
[0067] TD Temperature measuring device
[0068] PMD Particulate matter amount measuring device
[0069] ECU Engine control unit
[0070] G-ECU Engine controlling additional unit
[0071] MC Contactor
[0072] L Dummy load | A DPF system for an engine generator that performing a recovery process on a filter (DPF) provided to remove particulate matter generated by combustion of fuel when an amount of the particulate matter in the DPF exceeds a predetermined value, the engine generator performing the recovery process by carrying out an automatic recovery operation to raise a temperature of exhaust gas to combust the particulate matter, the system comprising: a dummy load connected to the engine generator when necessary; and control device for allowing the engine to perform a recovery preparation operation in such a manner that, once the amount of the particulate matter exceeds the predetermined value, the recovery operation is performed when the temperature of exhaust gas reaches a reference temperature, and the dummy load is connected to the generator to raise the temperature of exhaust gas when the temperature thereof fails to reach the reference temperature. | 5 |
This application is a continuation-in-part application of Ser. No. 210,010, filed Nov. 24, 1980, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to catalytic processes for improving asphaltic materials and the products resulting therefrom. This invention is concerned in one specific embodiment with chemically producing paving grade asphalt cements and in another embodiment with chemically producing roofing grade asphalts each being less susceptible to changes in temperature and methods for manufacturing the same through catalytic oxidation of paving grade or roofing grade asphalt flux feedstocks.
2. Prior Art
Historically paving grade asphalts were produced by the refiner by various methods or combinations of methods such as atmospheric distillation of crude oil with subsequent vacuum distillation to obtain the desired asphaltic product. Another method is air blowing, with or without an oxidation catalyst, a soft vacuum tower residual at 350°-550° F. either by a batch method or continuous in line oxidation to the desired product specification. Another method is to solvent precipitate a soft vacuum tower residual to product specifications; and still another method is to solvent precipitate a soft vacuum tower residual to a low penetration hard asphalt followed by back blending with a softer vacuum bottoms to achieve the proper specification characteristics.
All of the aforementioned methods can be used singularly or in combination to produce high quality asphaltic products. The choice of methods, in reality, is dependent upon the crude type. This invention is concerned with the above processes where air blowing in the presence of an oxidation catalyst is employed. We have discovered that by using the catalyst of the present invention, the "blowing curve" of the asphalt flux can be altered to produce a product having a higher penetration at a given softening point and in remarkably shorter time. As can be appreciated, both of these attributes are of considerable economic value.
In the past, bituminous materials, particularly asphalt materials, have been treated by passing an oxidizing gas through the bituminous materials in a molten condition. The effect of the conventional type of air-blowing is to partially oxidize the asphalt in a manner resulting in decreasing penetration and increasing viscosity and softening point. To promote the oxidation process, oxidizing catalysts have been utilized in the past. U.S. Pat. No. 1,782,186 states that the chloride, carbonate and sulfate salts of zinc, iron, copper or antimony can be used as catalyst in air blowing petroleum residuals to asphaltic materials. U.S. Pat. No. 1,782,186 exemplifies only the use of the chloride salt. Also, U.S. Pat. Nos. 2,179,208 and 2,287,511 describe processes for making asphalt. In all of the examples of U.S. Pat. Nos. 2,179,208 and 2,287,511, residuum is first air blown and then "polymerized" using halides of certain metals as catalysts. These two patents list other catalyst possibilities, including sodium carbonate. U.S. Pat. No. 3,440,073 discloses a method for deodorizing asphalt for use as sealants in refrigerators and freezers wherein air and steam are blown through molten asphalt flux to which has been added a small or minor quantity of a water solution of one or more water-soluble inorganic alkaline materials, such as sodium hydroxide, sodium carbonate, potassium hydroxide and potassium carbonate. The primary purpose of said treatment is to deodorize asphalt for special applications. Other patents of relevance to this invention are U.S. Pat. Nos. 2,370,007; 2,421,421; and 3,126,329.
Penetration by definition is the consistency of a bituminous material expressed as the distance in tenths of a millimeter that a standard needle vertically penetrates a sample of material under known conditions of loading, time, and temperature. In essence, the penetration of a bituminous material is synonymous with viscosity at the temperature specified.
Viscosity may simply be defined as the measure of the resistance to flow of a liquid in the presence of a force. It has been shown desirable in asphalts such as paving asphalts to have a high penetration at a given viscosity. For example, an asphalt pavement constructed with asphalt cement having a penetration at 77° F./100 g/5 sec. of 40, viscosity at 140° F. at 2000 poises, and a viscosity at 275° F. of 300 centistokes would not perform as well as the same asphalt having the same viscosities but a penetration at 77° F./100 g/5 sec. of 60. The 40 penetration asphalt at lower temperatures (below 77° F.) would become brittle and break up under repeated traffic load. In other words, the 40 penetration asphalt at 77° F. is more susceptible to changes in temperature.
One object of this invention is to catalytically produce a paving grade asphalt which is less susceptible to changes in temperature. Another object of this invention is to reduce the oxidation time. Another object of this invention is to provide an improved process for producing said asphalt. Still another object of this invention is to provide an improved and novel paving grade asphalt product.
Roofing asphalts are markedly different from paving asphalts. The air blowing process is frequently employed to manufacture certain paving grade asphalts; however, all roofing asphalts are manufactured by the air blowing process. One very important similarity exists between paving grade asphalts and roofing asphalts, i.e., a higher penetration at a given softening point is desirable. In other words, it is desirable to produce a roofing asphalt which is less susceptible to temperature change. Roofing manufacturers have historically used softening point which, in essence, is another method to designate viscosity.
Some roofing fluxes (roofing asphalt precursors) can be air blown to specifications without the use of a catalyst. Some require a catalyst. The use or non-use of a catalyst usually depends on the type of crude from which the roofing flux is derived. Refiners and asphalt roofing manufacturers have historically utilized Lewis acid catalysts such as halides of iron, aluminum, copper, tin, zinc, antimony, as well as phosphorus pentoxide in the production of roofing grade asphalts. Ferric chloride and phosphorous pentoxide are presently the most commonly used catalysts. These catalysts work quite well except they are very corrosive, and the amount of maintenance required on storage tanks, fume burners, pumps, etc. amounts to millions of dollars annually. In addition, the Lewis acid catalyzed asphalts deteriorate cellulosic-based products, such as roofing felts, spreading mops, etc., which are used during the manufacturing and application processes.
One of the objects of this invention is to catalytically produce a novel roofing asphalt which is less susceptible to changes in temperature. Another object of this invention is to reduce processing costs, and increase operating capacity by reducing the time for air blowing a roofing flux to roofing asphalt specification requirements. The reduction in total oxidation time is associated with the accelerated catalytic initiation of the oxidation reaction followed by a pronounced exotherm. Another object of this invention is to greatly reduce maintenance costs by utilizing a new non-corrosive, inexpensive, readily available catalyst. A further object of this invention is to provide a roofing asphalt which does not deteriorate cellulosics used in the roofing manufacturing and application processes. It is also an object of this invention to achieve an end product improvement over roofing asphalts produced by conventional catalysts known to the art such as ferric chloride, phosphorous pentoxide, etc., Another object of this invention is to produce, by catalysis, a novel, improved roofing material from a bituminous material which, when subjected to the normal non-catalytic air blowing process produces inferior roofing asphalts. Another object of this invention is to produce, by catalysis, a superior asphaltic roofing material exceeding specifications from a bituminous material which when subjected to the normal non-catalytic air blowing process produces only acceptable quality roofing asphalt. Another object of this invention is to provide improved catalytic processes for producing said asphalt.
Further objects of this invention will be apparent to the skilled artisan from the Summary and Detailed Description of the Invention, hereinbelow.
SUMMARY OF THE INVENTION
Briefly stated, this invention comprises processes for oxidizing asphaltic flux bituminous materials having boiling points above 850° F. which consist of blowing an oxidizing gas through a molten mixture of said bituminous materials in the presence of a catalytic amount of an oxidizing catalyst comprising an organic or an inorganic carbonate salt. The oxidizing catalyst can be either in the dry state, dissolved in water, slurried with water or slurried with bituminous feedstock material. The oxidation is conducted under a suitable condition of gas flow and temperature to oxidize the bituminous material to desired asphalt physical properties.
In a preferred embodiment, the oxidizing catalyst in the form of dry particles is injected directly into the asphalt flux.
In another preferred embodiment, the catalyst is a sesquicarbonate.
In a most preferred embodiment of this invention, the catalyst is sodium carbonate and either a paving grade asphalt or a roofing grade asphalt is produced, largely depending upon feedstock selection and oxidation time.
In another aspect, this invention comprises the oxidized asphaltic materials resulting from the aforedescribed processes.
In particular, this invention comprises: a non-corrosive catalyst which produces from poor quality bituminous materials, high quality finished asphaltic materials, without the need of corrosive Lewis acid catalysts, useful as roofing or paving products that are less susceptible to changes in temperature than comparable asphalts produced without catalysts, and the processes for producing same. The catalysts and related processes can also be used to further improve the quality of asphaltic materials derived from good quality asphalt fluxes. A possible added benefit of the present invention is that the process embodiments thereof do not produce chlorinated aromatics.
In certain preferred product embodiments of this invention, the asphalt product is characterized by an unusually small concentration of saturates as determined by clay gel analysis. The asphalt product of this invention is characterized by containing 25% to 85% less saturates than the concentration thereof in the starting flux.
More specifically, in preferred product embodiments, the present invention provides a catalytically oxidized paving grade or roofing grade asphalt. The paving grade asphalt comprises (by clay gel analysis, n-pentane solvent), about 15 to 25% pentane insoluble asphaltenes, about 3 to 15% saturates, about 30 to 50% polar compounds and about 25 to 35% aromatics, the total content being 100%, the sum of the asphaltenes and polar compounds being preferably about at least 55%. The roofing grade asphalt comprises about 35 to 45% pentane insoluble asphaltenes, about 5 to 30% saturates, about 30 to 40% polar compounds, with the remainder being about 10 to 30% aromatics, the sum of the asphaltenes and polar compounds being preferably about at least 70%. For both the paving and roofing grade products of the invention, the % saturates is at least 25% less than the saturate content of the starting flux, preferably at least 75% less, most preferably 80 to 85% less than the saturate content of the starting flux. Indeed, most preferably, the asphalt products of this invention will contain less than 8% saturates.
DESCRIPTION OF THE DRAWING
FIG. 1 of the Drawing is a graph in which viscosity is plotted versus penetration for identical asphalt fluxes oxidized with and without the presence of 1.0% sodium carbonate.
FIGS. 2 and 3 of the Drawing are graphs plotting the "blowing curves" (penetration versus softening point) of the experimental oxidation runs of Examples II and III, hereinbelow.
DETAILED DESCRIPTION OF THE INVENTION
Generally speaking, air blowing or oxidation of bituminous flux materials by the batch process is carried out as follows: Horizontal, or more commonly, vertical vessels with some means of heating such as direct fired burners, high pressure steam heat exchangers, etc. capable of maintaining temperatures up to 550° F. are employed. Various methods of controlling and dispersing air through the molten flux material are used. Most "batch oxidizers" are equipped with a cooling device such as a heat exchanger within or outside the vessel or a system for spraying water or injecting steam into the top of the vessel to quench the normally exothermic reaction experienced in the air blowing process. Batch oxidation is usually employed in manufacturing roofing grade asphalts.
Another type of oxidation process is a continuous process whereby a fresh bituminous feedstock material is continuously charged or fed into an oxidizer wherein catalyst and air are continuously and concurrently dispersed and contacted with the molten material on a "once-through" basis. The product, i.e., asphaltic material, is continuously discharged from the oxidizer. The process can be used for any type of bituminous feedstock material and is particularly useful in producing paving grade asphalt cements.
Although a number of carbonate salts are deemed suitable as catalysts for the present process, the preferred catalysts are the carbonate salts of sodium, and in particular, sodium carbonate or sodium sesquicarbonate, and mixtures thereof. Accordingly, other salts such as the carbonate salts of calcium, magnesium, barium and strontium may also be used as catalysts. The amount of catalyst utilized in the process of this invention to oxidize or air blow the molten flux, depending on the type of flux, can range between 0.01 and 5.0%, based on the weight of the flux material.
At times, it may be useful to utilize a catalytic salt which breaks down under heat to yield the carbonate as a decomposition product. Indeed, it is believed that the sesquicarbonate functions in this manner. The combination of carbonate plus sesquicarbonate may provide a means of continually supplying carbonate over a long period of time. Another carbonate precursor which may function satisfactorily under certain conditions is the corresponding bicarbonate salt. Similarly, an oxidation product of carbonate or bicarbonate, such as a peroxycarbonate, for example, sodium peroxycarbonate, could be employed to provide an active oxidation catalyst product. The term "carbonate salt catalyst" as used herein is meant to include not only compounds which from a nomenclature standpoint are carbonate salts, but also those materials as above discussed which yield carbonate as a decomposition product or which are carbonate or bicarbonate oxidation products.
According to the present invention, asphaltic materials for paving and roofing are produced from low grade bituminous materials, i.e., asphalt fluxes, which are derived from several sources.
The flux material, i.e., the liquid bituminous material is selected from the group consisting of slurry oil, coal tar pitch, coal tar, petroleum pitch, cycle oils, asphalt, cylinder stock, liquid derived from shale, coal liquifaction materials and aromatic furfural extracts from the solvent refining of lube oil and mixtures thereof.
In the oxidation processes, a bituminous feedstock material as aforementioned is fed into a vessel and is heated to a temperature ranging between about 300° and about 550° F. An oxidizing gas, such as air, is introduced into the flux material to oxidize the flux in the presence of the catalyst. The process is carried out for a sufficient length of time at about 450° to 550° F. to provide the type of asphaltic material desired, that is, an asphaltic material to be used for asphalt paving cements, roofing asphalts, including those used for built-up roofing, shingle saturates and shingle coatings. The present invention can lead to a reduction in oxidation time of at least about 10%, often over 20%.
The time of addition of catalyst to the flux in relationship to the beginning of introduction of the oxidizing gas is unimportant in the present invention as long as the oxidizing gas is used to oxidize the flux in the presence of the catalyst. For example, all of the catalyst could be loaded into the oxidizer before the introduction of the flux. Then, the flow of oxidizing gas could be started concurrently with the introduction of the flux or thereafter. This method is particularly suitable for batch operations. It is even possible to proceed in the opposite direction, that is start the flow of oxidizing gas before introduction of catalyst. The important parameter herein is that oxidation is carried out in the presence of the catalyst, whether the oxidation is accomplished in a single stage or in multiple stages. Where multi-stage oxidation is employed, it is possible to carry out one or more stages of oxidation without the presence of the catalyst, although at present it is thought that such a procedure would not fully enjoy the benefits flowing from this invention. Of course, a multi-stage process could be continuous or discontinuous, i.e., the use of a continuous oxidizer followed by one or two stages of batch oxidation.
The bituminous flux material has a viscosity ranging from about 30 to about 400 Saybolt Furol Seconds (SFS) at 210° F., and a flash point preferably of at least 580° F. Lower flash point materials can be used if the oxidation temperature is maintained at about 50° F. below the flash point for safety purposes.
In the process, the period of time required to respectively batch oxidize a roofing asphalt and a paving asphalt cement is quite different. In the case of an asphalt roofing coating, the oxidizing gas is passed through the flux containing the catalyst for a period of time, for example, ranging from about 2 to about 35 hours, whereas, in the case of producing the asphalt paving cement, the oxidizing gas is passed through the bituminous material containing the catalyst for a period of time, for example, ranging from about 1/2 hour to about 6 hours. These are merely suggested oxidation times.
The oxidizing gas that is passed through the flux or bituminous material may be one of several gases, including oxygen, air, compressed air, or liquid air. The oxidizing gas is passed through the flux material at a rate between about 20 and about 35 cubic feet per hour per ton of bituminous material.
The catalyst, as described above, that is used with the oxidizing gas is primarily a carbonate salt. The catalysts of the invention that may be used in this process include sodium carbonate, sodium bicarbonate, sodium sesquicarbonate, tetraalkylammonium carbonates, sodium cerium carbonate, trialkylammonium carbonates, dialkylammonium carbonates, or a carbonate salt of calcium, magnesium, lithium, cerium, potassium, barium, ammonium, strontium, transition metals, rare earth metals, bismuth, lead, tetraalkylphosphonium or tetraarylphosphonium. The catalyst is injected or introduced into the flux material in a water solution, water slurry, or slurried with said flux or in a preferred embodiment injected or introduced in a dry crystalline or powder form. The catalyst of the invention can be used in admixture with a conventional asphalt flux oxidation catalyst.
The amount of catalyst introduced into the flux material ranges from about 0.01 to about 5.0 wt. %, of the bituminous material, depending on type, preferably 0.1 to 1.0 wt. % for a paving asphalt cement, or 0.01 to 2.0 wt. % for a roofing shingle saturant and roofing shingle coating or built-up roofing asphalt material.
A starting flux for a paving grade asphalt will usually contain about 10 to 20% asphaltenes, about 15 to 25% saturates and about 20 to 35% polar compounds, with the remainder being aromatic compounds. On the other hand, a starting roofing grade asphalt will usually contain about 5 to 15% asphaltenes, about 10 to 35% saturates and about 20 to 35% polar compounds, with the remainder being aromatics.
Since as will be discussed in detail hereinafter, the catalytic oxidation of the present invention results in substantial reduction in saturate content, in one embodiment of the invention where a low saturate content roofing flux is employed, paraffinic hydrocarbon is admixed therewith to increase the saturate content of the flux. For example, with roofing flux having a saturate content approaching 10, say 11, paraffins could be added to the flux to increase the saturate content thereof up to 15 to 35, say about 20. This enables more of the chemical transformations brought about by the present invention to occur. Also, this embodiment illustrates the unique nature of the present invention compared to the use of catalysts such as ferric chloride, since the latter do not significantly affect saturates. As far as is known, any paraffin could be used in the practice of this inventive embodiment, such as waxes, petrolatums, straight or branched chain saturated hydrocarbons, etc. Branched chain saturates, such as petrolatums, are preferred, as illustrated by Example V, hereinafter. The paraffin can be added prior to catalyst or oxidizing gas introduction, or even thereafter during the oxidation process. A convenient method of paraffin introduction is to admix it with the catalyst and then add the admixture to the flux. Of course, this particular embodiment would not be made with paving cements.
The paving and roofing asphalt products that are produced according to the present invention are high grade asphaltic materials which, depending upon product properties, will be used for asphalt paving cements or as roofing asphalts such as shingle saturants and coatings or asphalts for built up roofing. The properties of the respective products do differ but according to the present invention, the amount of saturates that are included in the asphaltic product is from about 25% to about 85% less than the concentration of the saturates included in the precursor flux or bituminous material. In contrast with the use of an acidic catalyst, such as a Lewis acid, the catalyst of the present invention provides a product which has from about 25% to about 75% of the saturates component of the product as compared to that of the acidic catalyst products or those processed without a catalyst. More specifically, the present invention provides a catalytically oxidized paving grade asphalt comprising (by clay gel analysis, n-pentane solvent), about 15 to 25% pentane insoluble asphaltenes, about 3 to 15% saturates, about 30 to 50% polar compounds and about 25 to 35% aromatics, the total content being substantially 100%. The sum of the asphaltenes and polar compounds for a paving grade asphalt will preferably be at least 55%. The roofing grade asphalt comprises about 35 to 45% pentane insoluble asphaltenes, about 5 to 30% saturates, about 30 to 40% polar compounds and about 10 to 30% aromatics, the sum of the asphaltenes and polar compounds being preferably about at least 70%. The % saturates for both paving and roofing grade asphalts will be at least 25% less than the saturate content of the starting flux, preferably at least 75% less, most preferably 80 to 85% less than the saturate content of the starting flux. Most preferably, the saturate content will be about less than 8%.
The catalyst of the present invention offers a number of significant advantages. Uniquely, the carbonate catalyst significantly reduces saturate content, to a lesser extent reduces asphaltene content, significantly increases polar compound content and to a lesser extent increases aromatic content as compared to the same feed oxidized with or without conventional Lewis acid catalyst. Indeed, it appears that the carbonate catalyst essentially selectively oxidizes the saturates with no appreciable change in asphaltene content. This is opposite to the result expected from a normal oxidation with or without Lewis acid catalyst. In fact, this is an ideal oxidation according to the asphalt chemist, since it is well known that a high percentage content of saturates is detrimental to the desired viscosity-penetration relationship, especially for paving grade asphalts, as discussed hereinbefore. Examples hereinbelow illustrate the effect of the catalyst of this invention on the expected clay gel analysis of the asphalt product. A description of a conventional clay gel analysis procedure is set forth below.
CLAY-GEL ADSORPTION CHROMATOGRAPHIC METHOD OF ASPHALT ANALYSIS
Asphalts can be separated into hydrocarbon types and structural groups by this method. Asphaltenes, polar compounds, aromatics, and saturates can be isolated for further study and the yield determined. Asphaltenes are precipitated with n-pentane and filtered. The filtrate is charged to a glass percolation column containing clay in the upper section and silica gel (plus clay) in the lower section. The n-pentane is then charged to the double column until a definite quantity of effluent has been collected. The upper (clay) section is removed from the lower section and washed further with n-pentane which is discarded. A toluene-acetone mixture 50/50 by volume is then charged to the clay section and a specified volume of effluent collected.
The solvents are completely removed from the recovered pentane and the toluene-acetone fractions and the residues are weighed and calculated as saturate and polar compound contents, respectively. Aromatics are calculated by difference.
______________________________________Clay-Gel Analysis:______________________________________Component Composition:1. Asphaltenes (pentane insoluble)2. Polar Compounds (Resins)3. Aromatics - Resins Maltenes (portion soluble in pentane)4. Paraffins (Saturates)______________________________________
Other advantages of the present invention arise from the relatively inexpensive cost of the carbonates, particularly sodium carbonate and sodium sesquicarbonate, the lack of needing to prepare a water solution of the catalyst (ferric chloride is generally used in an aqueous solution form), the ability to avoid the corrosive effect of ferric chloride (believed to be largely caused due to generation of HCl) on manufacturing equipment such as metallic pumps, vats, pipes, and so on, on roofing structures such as metallic vents, flashing, drains, and on cellulosics such as application mops and roofing felts, and so on, reduced environmental pollution since HCl is not generated, the lack of generation of chlorinated aromatics, etc.
Some of the above advantages may be related to the fact that at least a part of the cation content of the carbonate catalyst becomes chemically and/or physically included within the asphalt. For example, with the use of sodium carbonate, at least some portion of the sodium ion and/or sodium metal reacts with the asphalt and cannot be removed by normal washing steps. For example, it is expected that in some embodiments the product of the present invention will contain up to about 30,000 ppm sodium as part of the asphalt component molecules. A typical analysis is less than 10,000 ppm, for example, 1 ppm in the saturate, 13 ppm in the aromatics, 35 ppm in the polar compounds and 3900 ppm in the asphaltenes.
A higher penetration of the asphaltic material for a given softening point or viscosity is an important property which illustrates the high grade of the asphaltic materials produced according to the present invention.
Asphalts produced by the present invention have the following properties: Paving grade asphalts cements have a penetration ranging from about 40 to about 300. Asphalts for built-up roofing have a penetration range from about 12 to about 60. Roofing shingle saturants have a penetration ranging from about 50 to about 90. Roofing coating asphalts have a penetration range from about 15 to about 25.
The asphalt products have softening points ranging from about 110° to about 250° F. The asphalt paving cements have a softening point ranging from about 110° to about 140° F., and the asphalt for built-up roofing has a softening point ranging from about 130° to about 230° F., roofing shingle coating has a softening point ranging from about 210° to about 250° F. and roofing shingle saturant has a softening point from about 110° to about 140° F.
In order to illustrate the advantages and scope of the present invention, the following non-limiting examples are provided.
EXAMPLE I
According to the present invention, a high quality paving grade asphalt cement is produced by air blowing a soft asphalt flux which normally does not yield a specification product when subjected to the air blowing process. The starting flux was made in the refinery by topping the crude oil by distillation under atmospheric conditions to produce a reduced crude residual. Said reduced crude residual was further distilled under reduced pressure to obtain a soft vacuum residual. Said soft vacuum residual without a catalyst was used as a feed to a 500 ml laboratory oxidizer. The temperature of said flux was raised to 480° F. in one hour. At this time, air was injected and dispersed into the oxidizer at a rate equivalent to 50 cu. ft./hr./ton. Said air rate remained constant and the temperature was maintained at 480°-500° F. until the penetration, 77° F./100 g/5 sec., on the blown flux reached a range of 60-70. The aforementioned asphalt flux and process was used as a "blank" or "control" to realistically illustrate the effect of the sodium carbonate catalyst on subsequent oxidations. The identical asphalt flux, air rate, and temperatures were used in successive separate oxidations, except 0.5, 1.0, and 2.0% by weight of sodium carbonate, based on flux, were respectively dissolved in water at 200° F. to enhance dispersion and each solution was respectively added to the three oxidations.
__________________________________________________________________________ AASHTO Test Starting 0% 0.5% 1.0% 2.0% Table IITest Method Flux Na.sub.2 CO.sub.3 Na.sub.2 CO.sub.3 Na.sub.2 CO.sub.3 NA.sub.2 CO.sub.3 AC-20 SPEC.__________________________________________________________________________Vis. at 140° F., ASTM D2171 56 1676 2160 1907 1860 1600-2400PoisePen. 77° F./100 g/5 ASTM D5 Soft 68 63 66 69 60 min.sec.Vis. at 275° F., CS ASTM D2170 75 324 364 339 346 300 min.Sol, Trichloro, % ASTM D2042 99.8 99.9 99.2 99.0 97.7 99.0+Soft. Point, °F. ASTM D36 -- 121 125 124 122 --Flash, °F. Coc ASTM D92 610 -- -- -- -- --Clay Gel Analysis ASTM D2007% Asphaltenes 10.9 23.0 20.3 20.1 20.9 --% Saturates 21.4 19.5 12.5 4.5 4.3 --% Polar Compounds 38.6 31.8 36.5 44.4 44.7 --% Aromatics 29.1 25.7 30.7 31.0 30.1 --Oxidation Time -- 8.0 5.3 3.5 4.6 --Hrs.__________________________________________________________________________
Table I shows the changes in the physical properties of the starting flux oxidized to AC-20 asphalt cement specifications without a catalyst compared with the identical flux oxidized with varying percentages (0.5, 1.0 and 2.0% of sodium carbonate). An abnormally high exothermic reaction was noted after the addition of sodium carbonate. Obviously 1% sodium carbonate is the optimum percentage to use according to the data in Table I. Larger percentages, although quite effective, decreases the solubility in trichloroethylene below the 99.0% minimum specified by the American Association of State Highway Officials (AASHTO). The chemical changes are dramatic. The saturates content of the 1% sodium carbonate catalyzed sample is about 77% less than the sample oxidized without sodium carbonate. Also there is a substantial increase in the polar compounds (about 40%) and in the aromatics (about 21%). This chemical phenomenon is very unusual and novel. Sodium carbonate selectively oxidizes mostly the saturate components of the asphalt converting them to polar compounds and aromatics. It is well known to those familiar with the art that saturate or paraffinic components, especially straight chain paraffins, are very susceptible to changes in temperature. Thus, the sodium carbonate catalyst of this invention reduces the percentage of the detrimental paraffinic components in said asphalt and increases the viscosities at 140° F. and 275° F. without appreciably affecting the penetration at 77° F./100 g/5 sec. The oxidation time on the 1% sodium carbonate catalyzed sample was 3.5 hours vs. 8.0 hours for the sample oxidized without catalyst. This result shows that the use of a catalyst according to the present invention can reduce the oxidation time for this process by slightly over 50%.
The rise in viscosity at a given penetration of an identical feedstock oxidized with 1.0% sodium carbonate and 0% sodium carbonate are graphically shown on FIG. 1. The asphalt oxidized with sodium carbonate obviously has a higher viscosity at any given penetration.
The relative effectiveness of two catalysts well known to the art: ferric chloride (FeCl 3 ) and phosphorous pentoxide (P 2 O 5 ) compared with sodium carbonate and a control sample without catalyst are shown in Table II. All of the oxidations were carried out with the identical starting flux and oxidized under the same conditions of temperature and air rate. The only variation was the type of catalyst. All of the oxidized asphalts met the AASHTO Table II AC-20 specifications. The asphalt produced without a catalyst had a very low viscosity at 140° F. The saturates content is markedly lower on the sample oxidized with sodium carbonate. The asphaltene content is lower on said sample and there is a considerable increase in polar compounds and aromatics. The asphalt oxidized with sodium carbonate is non-corrosive and those oxidized with ferric chloride and phosphorous pentoxide are very corrosive. The oxidation time of the asphalt oxidized with sodium carbonate was 3.5 hours vs. 8.0 hours for the asphalt without catalyst, seven hours for the asphalt oxidized with phosphorous pentoxide catalyst and 3.5 hours for the sample oxidized with ferric chloride.
EXAMPLE II
Asphalt Roofing Coating
In a second part of our invention, we produced a high quality roofing asphalt coating in plant scale experiments in order to demonstrate the effectiveness of sodium carbonate catalyst vs. ferric chloride, and as compared with oxidation without the use of a catalyst. Identical feedstock was used in each experiment.
TABLE II__________________________________________________________________________OXIDATION OF VACUUM RESIDUAL STARTING FLUX WITHOUT CATALYST COMPAREDWITH CATALYTIC OXIDATION WITH SODIUM CARBONATE, FERRIC CHLORIDE, ANDPHOSPHORUS PENTOXIDE AASHTO Test Starting 0% 1% 0.1% 1% Table IITest Method Flux Catalyst Na.sub.2 CO.sub.3 FeCl.sub.3 P.sub.2 O.sub.5 AC-20 SPEC.__________________________________________________________________________Vis. at 140° F., ASTM D2171 56 1676 1907 2000 2000 1600-2400PoisePen. 77° F./100 g/5 ASTM D5 Soft 68 66 60 66 60 min.sec.Vis. at 275° F., Cs ASTM D2170 75 324 339 363 390 300 min.Sol, Trichloro, % ASTM D2042 99.8 99.9 99.0 99.7 99.2 99.0+Soft. Point, °F. ASTM D36 -- 121 124 125 125 --Flash, Coc, °F. ASTM D92 610 -- -- -- -- --Clay Gel Analysis ASTM D2007% Asphaltenes 10.9 23.0 20.1 23.7 26.3 --% Saturates 21.4 19.5 4.5 20.1 18.9 --% Polar Compounds 38.6 31.8 44.4 28.3 28.4 --% Aromatics 29.1 25.7 31.0 27.9 26.4 --Oxidation Time -- 8.0 3.5 3.5 7.0 --Hrs.__________________________________________________________________________
A 7,000 gallon asphalt oxidizer was charged in each experiment with said feedstock. In the experiment containing no catalyst, the temperature on the batch oxidizer was raised to 440° F. At this time, air was introduced and dispersed in the oxidizer at a rate of 35 SCFH per ton of feedstock until laboratory tests showed that the asphalt was within the softening point specification range. This experiment was repeated successively by experiments respectively using ferric chloride and sodium carbonate. All other conditions were the same. The sodium carbonate (0.8% based on the weight of the starting flux in the oxidizer) was dissolved in water and injected into the top of the oxidizer. The ferric chloride (0.3% based on the weight of the starting flux in the oxidizer) was injected into the oxidizing vessel in the exact same manner. The "blowing curves" of the three asphalts are shown in FIG. 2. The sample oxidized with ferric chloride excelled the one oxidized without catalyst. The sample oxidized with sodium carbonate excelled both the one oxidized without a catalyst and the one oxidized with 0.3% ferric chloride. Again, the asphalt oxidized with sodium carbonate has a higher penetration for any given softening point or is less susceptible to changes in temperature.
EXAMPLE III
Sodium Carbonate Catalyst
We performed another larger plant experiment in a different plant from that cited in Example II to further illustrate the effectiveness of sodium carbonate catalyst vs. oxidation without a catalyst on a feedstock derived from a different crude source. A 27,720 gallon batch asphalt oxidizing vessel was charged with said feedstock. No catalyst was used in the first experiment. The temperature in the oxidizer was raised to 350° F. and at this temperature air was introduced and dispersed into the oxidizer at a rate of 15 SCFH per ton. When the temperature reached 490° F., a water spray was used to spray the top of the molten asphalt within the oxidizer to maintain a temperature of 490°-500° F. This water spray was used to control the temperature at the 490°-500° F. range for safety reasons established by the refinery where the test was conducted. The temperature (490°-500° F.) was maintained until the oxidation was concluded as dictated by laboratory results on the oxidized asphalt which showed that the asphalt was within specification range. In a second part of the experiment, the said identical starting flux was oxidized in the exact manner except 0.8% sodium carbonate, based on weight of flux, was dissolved in water at 200° F. and introduced into the top of the oxidizer at the surface of the molten asphalt at the same time air was introduced into the bottom of the oxidizer. FIG. 3 shows the results of the experiment and illustrates that at a given softening point the corresponding penetration is higher on the asphalt catalytically oxidized with sodium carbonate or the said catalytically oxidized asphalt is less susceptible to changes in temperature than the asphalt oxidized without a catalyst.
EXAMPLE IV
A number of plant scale runs were carried out with the following results. These runs illustrate the use of dry catalyst being directly added to the oxidizer containing asphalt flux.
A. Commercially available sodium sesquicarbonate crystals were pressure injected into an oxidizer containing 400 barrels of an asphalt flux derived from Illinois Basin crude oil (0.5% by weight of catalyst based on the flux). The carbonate crystals were injected after the oxidizer had reached a temperature of about 350° F. The oxidation was carried out for approximately 20 hours during which time the temperature gradually increased to 500° F. The asphalt product had a penetration of 19 and a softening point of 224° F., in comparison with a control (no catalyst) which had a penetration of 17 and a softening point of 216° F. after the same length of time.
B. In another run, but using an asphalt flux obtained from Murban crude oil and 0.6% by weight of the crystalline sodium sesquicarbonate as catalyst, and a maximum temperature of 490° F. after 24 hours an asphalt having a penetration of 19 and a softening point of 225° F. was obtained. This time, the control run yielded an asphalt having a penetration of 15 and a softening point of 225° F.
C. In this run, 400 barrels of a mixed asphalt flux, that is derived from mixed crude oil sources, was oxidized in the presence of 0.25% by weight sodium carbonate provided to the oxidizer in a dry powdered form. The oxidation was carried out for 26 hours at a maximum temperature of 500° F. The product had a penetration of 18 and a softening point of 223° F. The values obtained with the control oxidized under the same conditions in the absence of catalyst were a penetration of 14 and softening point of 224° F.
D. Another mixed asphalt flux was oxidized for 27 hours at a maximum temperature of 500° F. in the presence of 0.5% by weight dry powdered sodium carbonate to yield an asphalt having a penetration of 20 and a softening point of 222° F. The control yielded a product having a penetration of 14 and a 224° F. softening point.
In each of the above runs A through D, the total amount of catalyst was added when the oxidizer reached the oxidation temperature of about 350° F.
EXAMPLE V
This example illustrates the embodiment of the present invention where a paraffinic hydrocarbon is admixed with a low saturate content roofing grade flux and then the catalytic oxidation of the present invention is carried out.
A number of laboratory runs were carried out. In each run, 500 grams of the same roofing grade flux having a saturate content of 11% was oxidized at 480° F. with air as oxidizing gas being provided at a rate of 1.0 SCFH (one standard cubic foot per hour). In each of the runs where sodium carbonate was used as a catalyst during the oxidation, it was added to the flux, in an amount to provide 1% sodium carbonate based on weight of the flux, in the form of a water solution thereof prior to commencement of addition of the oxidizing gas.
Run A
In the first run, carried out without catalyst addition, the asphalt product had a penetration of 10 and a softening point of 230° F. after an oxidation time of 21 hours.
Run B
Run B was identical to Run A except for the addition of the sodium carbonate catalyst. The asphalt product had a penetration of 10 and a softening point of 241° F. after 21 hours oxidation time.
Run C
Run C was identical to Run A except that the starting flux consisted of 90% of the flux of Run A admixed with 10% wax. After 24 hours oxidation time, the asphalt product had a penetration of 15 and a softening point of 229° F.
Run D
Run D was identical to Run C (10% wax) except that the sodium carbonate catalyst was present during the oxidation. The asphalt product had a penetration of 18 and a softening point of 239° F. after 21 hours oxidation time.
Run E
Run E was identical to Run C except that the wax content was raised to 20% (80% Run A flux/20% wax). The asphalt product had a penetration of 19 and a softening point of 227° F. after 14.5 hours oxidation time.
Run F
Run F was identical to Run C except that a petrolatum was used in place of the wax as the added saturate. After 161/3 hours oxidation time, the asphalt product had a penetration of 11 and a softening point of 232° F.
Run G
Run G was identical to Run F except that the sodium carbonate catalyst was present. The asphalt product had a penetration of 17 and a softening point of 230° F. after 8.5 hours oxidation time.
Variations of the invention will be apparent to the skilled artisan. | Disclosed is a process for producing high grade asphaltic materials from low grade bituminous materials and the improved products resulting therefrom. More particularly, there is disclosed a process utilizing a particular type of oxidation catalyst in preparing novel high quality paving grade asphalt cements and novel roofing grade asphalts from poor and marginal quality bituminous materials. Also, the process can be used to prepare novel superior quality asphaltic materials from good quality bituminous flux feedstocks. This process consists of catalytically oxidizing asphalt fluxes, for example, in a single or multi-stage oxidation, using the particular type of catalyst disclosed hereinafter in each stage to chemically modify the flux so that the resultant asphaltic material meets physical requirements necessary for a finished product possessing good temperature susceptibility characteristics. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2010-93745, filed on Sep. 28, 2010, the entire contents of which application is incorporated herein for all purposes by this reference.
BACKGROUND OF INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a hydromount absorbing and alleviating vibration of driving components such as an engine, a power train, a transmission, and the like of a vehicle, and more particularly, to a three point supporting bush type hydromount in which inner pipes are disposed in a horizontal direction of a vehicle frame.
[0004] 2. Description of Related Art
[0005] In general, suspension parts of a vehicle act to control displacement and perform a vibration-proof operation for a power plant including an engine and a transmission.
[0006] Vibration phenomena of the vehicle include the shaking of a vehicle body when the engine starts and stops, the vibration of the vehicle body in idling, the vibration of the vehicle body when the engine is in high RPM, the vibration by a bump, the shaking of the vehicle body when a high load is given, an impact when a sudden change occurs in acceleration or shifting, interference and breakage by excessive displacement, etc.
[0007] Origins of the vibration include a torque fluctuation when the engine is in low RPM, the vibration of a power plant by inertial force and couple force by rotary motion of a crank shaft when the engine is in low RPM, and the vibration of a power plant by couple force and thrust force by a driving system joint angle, etc., in the case of a low-frequency region (30 Hz or less).
[0008] In addition, the origins of the vibration include the vibration of a power plant by inertial force and couple force by rotary motion of the crank shaft when the engine in high RPM, the engagement vibration of gears in the transmission, the vibration of a cylinder block in combustion, the moving valve system vibration of an engine, the bending of a crank shaft, torsional vibration, the bending of a power plant, etc., in the case of a high-frequency region (30 Hz or more).
[0009] The vibration causes noise and the noise is transferred up to the interior of the vehicle via the vehicle body to be a chief cause in deteriorating ride comfort.
[0010] Therefore, when driving components such as the engine, the power train, the transmission, etc. are mounted on an engine room, a mount capable of supporting the driving components while withstanding their weights and absorbing and alleviating vibration so as to transfer minimum vibration to the vehicle body is mounted.
[0011] Since the mount should alleviate/absorb the vibrations of the driving components and withstand load weights of the driving components, the mounting locations, the number, and the structures of the mounts are designed by considering the weights, structures, chasses, body structures, etc. of the driving components.
[0012] When the mounts support the engine, the power train, and the transmission, the mounts are referred to as an engine mount, a power train mount, and a transmission mount, respectively. The engine of the vehicle including the transmission is connected to lower and side frames of the vehicle body by the mounts.
[0013] The structure of the mount is divided into a rubber mount and a hydromount (hydraulic mount).
[0014] The rubber mount has a structure in which elastic rubber is interposed between an upper plate and a lower plate and damps vibration and noise by using the elastic rubber.
[0015] The hydromount includes a liquid chamber part and a space part of a diaphragm, and has a structure in which a liquid chamber of the liquid chamber part is pressed to store fluids in the diaphragm through an orifice and damps vibration and noise through the fluids.
[0016] The mount used particularly for the transmission among the mounts is mounted on the vehicle body in a four point inertial supporting method or a three point inertial supporting method. In the mount mounted in the four point inertial supporting method, a mounting direction of an inner pipe of the mount is a forward and backward direction of the vehicle, while as shown in an outline diagram of a known three point inertial mount of FIGS. 1A and 113 and a perspective view of the known three point inertial mount of FIG. 2 , a direction of an inner pipe 102 of the mount 101 mounted on a vehicle frame 100 in a three point inertial supporting method is a horizontal direction of the vehicle frame 100 in order to enhance noise and vibration and an amount of forward and backward rubber when the vehicle is accelerated. Therefore, since the three point mount has mounting locations less than the four point mount by one, the structure of the three point transmission mount needs to be designed as the hydromount structure in order to solve a disadvantage in which ride comfort is relatively worse as the movement of the transmission is larger.
[0017] However, when the direction of the inner pipe of the hydromount is designed as the horizontal direction of a vehicle, since the inner pipe cannot withstand excessive input in the forward and backward direction of the vehicle, the diaphragm formed by a thin film having low hardness, which is provided in the mount, is broken due to lack of durability, and as a result, the hydromount may lose the hydromount function.
[0018] The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
SUMMARY OF INVENTION
[0019] Various aspects of the present invention provide for a three point inertial supporting bush type hydromount in which inner pipes are disposed in a horizontal direction of a vehicle frame.
[0020] Various aspects of the present invention also provide for a three point supporting bush type hydromount, the hydromount including a diaphragm unit having a diaphragm formed by a rubber curing method in an inner part of a bobbin-shaped outer pipe, a main rubber part having an inner pipe formed by the rubber curing method in an inner part of a bobbin-shaped saddle stitching portion which press-fits in the diaphragm unit, and a main liquid chamber, and a diaphragm cover bound between the main liquid chamber and the diaphragm to protect the diaphragm and forming an orifice that allows fluids to flow.
[0021] Effects of a three point supporting bush type hydromount according to various aspects of the present invention having the above-mentioned configuration are as follows.
[0022] First, a diaphragm which is a fluid storage of the hydromount of the present invention is positioned in a lower part of a main liquid chamber and a diaphragm cover is interposed between the lower part of the main liquid chamber and the diaphragm, such that a stopper function to control a large displacement of a main rubber part is provided by the diaphragm cover and a possibility of fracture of the diaphragm of the hydromount by a forward and backward load pointed out as a known problem is remarkably reduced to protect the diaphragm.
[0023] Second, in the hydromount of the present invention, rubber is filled in both space parts of an upper part of the main liquid chamber to reduce acceleration penetration noise and a shock/jerk when a vehicle is accelerated and decelerated.
[0024] Third, a space to increase a rubber amount is ensured in a rear part of the vehicle where large acceleration displacement occurs a lot by placing an orifice formed by the diaphragm cover of the hydromount of the present invention eccentrically in front of the vehicle, such that a structure to further improve a vibration damping effect is provided.
[0025] The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIGS. 1A and 1B are diagram showing a state when a known three point supporting type mount is mounted.
[0027] FIG. 2 is a perspective view of a mount used in a known three point supporting type.
[0028] FIG. 3 is an exploded perspective view of an exemplary three point supporting bush type hydromount according to of the present invention.
[0029] FIG. 4 is a bottom perspective view of an exemplary three point supporting bush type hydromount according to the present invention.
[0030] FIG. 5 is a cross-sectional view of an exemplary three point supporting bush type hydromount according to the present invention.
[0031] FIG. 6 is a perspective view of a saddle stitching unit of an exemplary three point supporting bush type hydromount according to the present invention.
[0032] FIG. 7 is a partial cut-away view of an exemplary three point supporting bush type hydromount according to the present invention.
[0033] FIG. 8 is a comparison graph of the vehicle vertical damping performance of an exemplary three point supporting bush type hydromount according to the present invention.
[0034] FIG. 9 is a comparison graph of a vehicle forward and backward characteristic of a static spring of an exemplary three point supporting bush type hydromount according to the present invention.
DETAILED DESCRIPTION
[0035] Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
[0036] Hereinafter, a configuration of a three point supporting bush type hydromount according to various embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0037] However, the accompanying drawings are provided as examples in order to fully transfer the spirit of the present invention to those skilled in the art. Therefore, the present invention is not limited to the accompanying drawings and may be implemented in various forms.
[0038] Further, unless terms are defined, they have meanings understood by those skilled in the art and known functions and configurations which may unnecessarily obscure the scope of the present invention will not be described in the following description and accompanying drawings.
[0039] FIG. 3 is an exploded perspective view of a three point supporting bush type hydromount according to various embodiments of the present invention and FIG. 4 is a bottom perspective view of an assembling state of the three point supporting bush type hydromount according to various embodiments of the present invention.
[0040] Referring to FIGS. 3 and 4 , the hydromount 1 according to various embodiments of the present invention includes a diaphragm unit 10 having a diaphragm 12 formed by a rubber curing method in an outer pipe 11 having a bobbin shape which is a cylindrical shape in which an upper portion and a lower portion are opened, and a main rubber part 20 having an inner pipe 22 formed by the rubber curing method in a bobbin-shaped saddle stitching portion 21 .
[0041] The configuration of the hydromount according to various embodiments of the present invention is different from a configuration of a known hydromount in which rubber is not cured in the outer pipe and the diaphragm is cured integrally with the main rubber part to have the same hardness and material as the main rubber part.
[0042] Further, the hydromount according to various embodiments of the present invention includes a diaphragm cover 30 attached between a lower part of the saddle stitching portion 21 and the diaphragm 12 to form an orifice that allows fluids to flow while protecting the diaphragm 12 .
[0043] The diaphragm unit 10 and the main rubber part 20 are each manufactured, the diaphragm cover 30 is bound to a lower part of the main rubber part 20 and the fluids are filled therein, and the main rubber part 20 press-fits in the diaphragm unit 10 to assemble the hydromount according to various embodiments of the present invention. In this case, for improvement of performance such as prevention of leakage of the fluids or increase in durability, a swaging process may be performed after the assembly.
[0044] In this case, the diaphragm unit 10 and the main rubber part 20 may be different from each other in a material and hardness of used rubber.
[0045] FIG. 5 is a cross-sectional view of the hydromount according to various embodiments of the present invention. As shown in the figure, the hydromount according to various embodiments of the present invention has a structure different from the known hydromount.
[0046] That is, in the known hydromount, the liquid chamber is positioned in a lower part of a bush or bushing and the diaphragms are positioned in two locations such as left and right parts of an upper part of the bush, while in the hydromount according to various embodiments of the present invention, the lower liquid chamber of the known hydromount is divided into two chambers, and the upper chamber acts as a main liquid chamber part and the diaphragm cover 30 having a function as a stopper for controlling large displacement of the main rubber part in order to improve durability, a function to protect the diaphragm, and a function to configure the orifice, which is formed in the middle thereof.
[0047] The main rubber part 20 of the three point supporting hydromount according to various embodiments of the present invention includes a main liquid chamber 40 formed in a lower part of the inner pipe 22 by the rubber curing method. Therefore, in the hydromount according to various embodiments of the present invention, the diaphragm 12 positioned on upper left and right ends of the known inner pipe is positioned in a lower part of the main liquid chamber 40 and an orifice having a predetermined length is provided between the main liquid chamber 40 and the diaphragm 12 .
[0048] Further, rubber that plays a buffering role when the vehicle is accelerated or decelerated is filled in both space parts 50 and 50 ′ of the inner pipe 22 in an upper part of the main liquid chamber 40 so as to improve acceleration penetration noise and reduce a shock/jerk.
[0049] FIG. 6 is a perspective view of a saddle stitching portion 21 of the hydromount according to various embodiments of the present invention and FIG. 7 is a partial cut-away diagram of the three point supporting bush type hydromount according to various embodiments of the present invention.
[0050] Referring to the figures, the saddle stitching portion 21 has a bobbin shape and includes a first through-hole 21 a formed on one side surface and a second through-hole 21 b formed from the other side surface to the bottom thereof. The first through-hole 21 a has a rubber filling space to improve vibration damping and absorption efficiencies in an acceleration section.
[0051] Further, as shown in FIG. 7 , the diaphragm cover 30 is attached to a lower part of the second through-hole 21 b to provide an orifice 60 forming a path of fluids between the main liquid chamber 40 and the diaphragm 12 .
[0052] In this case, the orifice is eccentrically disposed in front of the vehicle, considering that large displacements of most of the movement directions are inputted in a rear direction of the vehicle when the vehicle is operated and the resulting shock and acceleration penetration sound are generated, and the orifice is eccentrically disposed in a front direction of the vehicle in order to reflect a structure in which rubber is primarily filled in a rear part of the vehicle.
[0053] FIG. 8 is a comparison graph of the vehicle vertical damping performance of the three point supporting bush type hydromount according to various embodiments of the present invention and FIG. 9 is a comparison graph of a vehicle forward and backward characteristic of a static spring of the three point supporting bush type hydromount according to various embodiments of the present invention.
[0054] As shown in the graph of FIG. 8 , when the vehicle vertical damping performance of the hydromount according to various embodiments of the present invention is compared with that of the known rubber mount, a value of tan δ indicating the damping force of the mount is approximately 0.1 in the known rubber mount at a resonance point P 1 , while approximately 0.44 in the hydromount according to various embodiments of the present invention. Therefore, the hydromount according to various embodiments of the present invention is has a damping characteristic approximately 4 times higher than the known rubber mount and the high damping characteristic shows that the hydromount according to various embodiments of the present invention can suppress vibration in resonance of a vehicle shaft and improve driving ride comfort.
[0055] Further, as shown in the graph of FIG. 9 , when a vehicle forward and backward static spring characteristic of the hydromount according to various embodiments of the present invention is compared with that of the known rubber mount, the hydromount according to various embodiments of the present invention has the smaller displacement (a horizontal axis of the graph) when the hydromount has the same load (a vertical axis of the graph). For example, when the load is 120 Kgf, the displacement of the hydromount according to various embodiments of the present invention is 6 mm at point Q 1 , while the displacement of the known rubber mount is 7 mm at point Q 2 . Therefore, since the displacement of the hydromount according to various embodiments of the present invention is smaller under the same load, a vibration suppression effect is larger and a possibility of fracture of the diaphragm of the hydromount by a forward and backward load pointed out as a known problem is remarkably reduced.
[0056] For convenience in explanation and accurate definition in the appended claims, the terms upper or lower, front or rear, inside or outside, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
[0057] The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. | A hydromount absorbs and alleviates vibration of driving components such as an engine, a power train, a transmission, and the like of a vehicle, and more particularly, to a three point supporting hydromount in which inner pipes are disposed in a horizontal direction of a vehicle frame. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a front gear derailleur shifting mechanism for bicycles and, more particularly, to a shifting mechanism which includes indexing for accurate derailleur movement with respect to sprockets of a corresponding sprocket set.
2. Description of the Related Art
Bicycles, for instance racing bicycles and mountain bicycles, often include both front and rear chain derailleur mechanism having corresponding handlebar mounted shifting mechanisms. The shifting mechanism effects positional changes of the chain derailleur mechanism by controlling movement of a cable connected therebetween. Recently, such shifting mechanisms have included indexing devices which cause the positional changes to be accurately controlled to put the chain derailleur into generally consistent predetermined positions with respect to chain sprockets in a corresponding sprocket set.
Most rear chain derailleur mechanisms, shifting mechanisms and the corresponding chain sprockets are designed, sold and installed on a bicycle as a matched set where the indexing device in the shifting mechanism is configured to selectively position the chain derailleur in approximate alignment with each chain sprocket of the corresponding sprocket set. However, front chain derailleurs are often not installed on a bicycle as a set with a corresponding set of chain sprockets, but rather the front gear derailleur and shifting mechanism may be used with a sprocket set whose sprockets that have dimensions different from those the shifting mechanism's indexing was designed to function with. Consequently, the indexing of the shifting mechanism may cause the chain derailleur to move to a position that is not in acceptable alignment with one of the sprockets of the sprocket set, thus causing the chain to scrape the derailleur, or worse, may not allow the chain to properly engage the one of the sprockets in the sprocket set.
A known indexed shifting apparatus for bicycles is disclosed in U.S. Pat. No. 5,203,213. As shown in FIGS. 3 and 4 of that patent, this type of shifting device includes a support shaft (11) fixed to a bracket (B) mounted on a handlebar; a takeup reel (2) rotatably mounted on the support shaft (11) for alternately pulling and releasing a control cable (I) a first control lever (4) pivotable about the support shaft (11) for causing the takeup reel (2) to pull the control cable (I); and a second control lever (7) for causing the takeup reel (2) release the control cable (I). The first control lever (4) engages feed teeth (21) on takeup reel (2) through a feed pawl (41) to cause the takeup reel (2) to rotate in the cable pulling direction. The second control lever (7) engages two sets of position retaining teeth (31,61) takeup reel (2) through two pawls (32,62) to cause the takeup reel to rotate in the cable release direction. The first control lever (4) and the second control lever (7) are both mounted at a position below the handlebar for operation by the index finger and thumb of a cyclist's hand.
The above described bicycle shifting mechanism is configured for shifting between five or more chain sprockets in a sprocket set and is typically used with the rear derailleur of a bicycle. However, with minor modification, for instance, fewer position retaining teeth, the shifting apparatus may be used with a front gear derailleur. Front gear derailleurs are typically used with a sprocket set having only two or three sprockets, thus necessitating reducing the number of position retaining teeth in the shifting mechanism. However, there remains the problem of accurately positioning the derailleur with sprockets in a sprocket set whose positioning requirements differ from the configuration of the indexing of the shifting mechanism.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a shifting mechanism that may be used with multiple types of sprockets sets, each sprocket set having dimensions differing from other sprocket sets.
In accordance with one aspect of the present invention, a shifting mechanism is configured for selectively moving a chain derailleur between a plurality of positions corresponding to positions of sprockets of plurality of differing sprocket sets. The shifting mechanism includes a control member mounted for selective rotational movement within the shifting mechanism structure. The control member is formed with a plurality large position retaining teeth and a plurality of small position retaining teeth, at least one of the small position retaining teeth formed between each adjacent ones of the large position retaining teeth. Each of the large position retaining teeth is positioned on the control member to correspond to the positions of the sprockets in a first of the plurality of differing sprocket sets, and at least one of the small position retaining teeth corresponds to the position of one sprocket in a second of the plurality of differing sprocket sets.
These and other objects, features, aspects and advantages of the present invention will become more fully apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings where like reference numerals denote corresponding parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a bicycle having a handlebar and a seat, the bicycle being equipped with a bicycle shifting apparatus in accordance with the present invention;
FIG. 2 is a fragmentary, elevational view of the shifting apparatus attached to the handlebar of the bicycle depicted in FIG. 1, looking from the seat toward the handlebar;
FIG. 3 is a part elevational view, part cross-sectional view of the shifting apparatus depicted in FIG. 2, shown removed from the handlebar, taken along the line III--III of FIG. 2, the shifting apparatus having a control member, a release pawl and a drive pawl;
FIGS. 4A-4I are views illustrating various positions of the release pawl, the drive pawl and the control member of the shifting apparatus depicted in FIG. 3, the release pawl, the drive pawl and the control member shown removed from the shifting apparatus for clarity;
FIGS. 5A-5F are views illustrating two differing sprockets sets, one sprocket set shown in the upper portion of each FIGS. 5A-5F and another sprocket set shown in the lower portion of each of FIGS. 5A-5F, the position of a chain derailleur is shown in each of FIGS. 5A-5F with respect to the two sprocket sets, the position of the derailleur in FIG. 5A corresponding to the position of the control member depicted in FIG. 4A, the position of the derailleur in FIG. 5B corresponding to the position of the control member depicted in FIG. 4C, the position of the derailleur in FIG. 5C corresponding to the position of the control member depicted in FIG. 4D, the position of the derailleur in FIG. 5D corresponding to the position of the control member depicted in FIG. 4E, the position of the derailleur in FIG. 5E corresponding to the position of the control member depicted in FIG. 4F, and the position of the derailleur in FIG. 5F corresponding to the position of the control member depicted in FIG. 4G;
FIG. 6 is an elevational view of a prior art release pawl and corresponding prior art control member that are configured for use with a single sprocket set;
FIG. 7 is an elevational view similar to FIG. 6, showing a release pawl and corresponding control member in accordance with an alternate embodiment of the present invention, the release pawl and control member being configured for use with multiple sprocket sets.
DETAILED DESCRIPTION OF THE EMBODIMENTS
FIG. 1 is a side view of a bicycle (1) in accordance with the present invention having a handlebar (18), a front derailleur (200) and a rear derailleur (7) and a seat (6). To control the position of the derailleur (200), a shifting apparatus (10) is installed on the handlebar (18). The detailed structure of shifting apparatus (10) is shown in FIGS. 2 and 3. The shifting apparatus (10) includes a mounting bracket (14) for mounting the shifting apparatus (10) to a handlebar (18). However, it should be appreciated that the shifting apparatus could be mounted elsewhere on the bicycle. As shown in FIG. 2, the shifting apparatus (10) is configured to be mounted adjacent to a brake lever, the brake lever shown in dashed lines in FIG. 2. The shifting apparatus (10) also includes: a housing cover (22) which houses the shifting components; a main lever (26) for causing the shifting apparatus (10) to pull on an inner wire (28) (see FIG. 3) of a shifting cable (30); and a release lever (34) for causing the shifting apparatus to release the inner wire (28). Due to the proximity to the brake lever shown in FIG. 2, the shifting apparatus (10 is operated using two fingers. The bicycle rider may use a thumb to depress the main lever (26) and a forefinger to pull upward on the release lever (34), with respect to FIG. 2. In FIG. 3, the housing cover (22) has been removed for greater clarity.
A support from (38) is formed with bracket (14) which secures the shifting apparatus (10) to the handlebar (18). The bracket (14) is adapted to be fastened to handlebar (18) by a mounting screw (40). A main pivot post (44) extends through an opening (48) in the support frame (38). A takeup element (52) is rotatably mounted to main pivot post (44) and is biased in a cable unwinding direction by a spring (60). A cable retainer (not shown) is fastened to the end of inner cable (28) and is retained by the takeup element (52) in a well known manner. Inner cable (28) is guided within a cable winding groove (68) during the shifting operation. A control member (72) is fixed to takeup element (52) so as to rotate integrally with it. As described in more detail below, control member (72) includes a plurality of large position retaining teeth (80a, 80b and 80c), a plurality of small positioning teeth (82a, 82b, 82c, 82d, 82e and 82f) and plurality of drive teeth (84) shown in FIGS. 4A-4I, for rotating and controlling the position of takeup element (52) in conjunction with main lever (26) and release lever (34).
Release lever (34) is rotatably mounted to a release pivot post (92) which, in turn, is mounted to the support frame (38) and a cover (39) attached to the support frame (38). A spring (94) mounted between release lever (34) and release pivot post (92) for biasing release lever (34) to a home position (as shown in FIG. 2). A release pawl (98) is also rotatably mounted to the release pivot post (92) and is biased in a clockwise direction (with respect to FIGS. 4A through 4I) by a release pawl spring (102). Release pawl (98) shown in FIGS. 4A-4I includes spaced apart jaws (104,106) for engaging the large and small position retaining teeth (80a-80c) and (82a-82f) on control member (72) in a manner discussed below. A release lever tab (not shown) on release lever (34) contacts a portion of release pawl (98) to pivot release the pawl with counterclockwise movement (with respect to FIGS. 4A-4I) of release lever (34). Details concerning the release lever tab (not shown) are similar to the operation and configuration of the shifting mechanism described in co-pending and commonly assigned U.S. patent application Ser. No. 08/588,659, filed Jan. 19, 1996. The entire contents of U.S. patent application Ser. No. 08/588,659, filed Jan. 19, 1996 are incorporated herein by reference.
Main lever (26) is rotatably mounted to main pivot post (44) by a retainer nut (113). The post (44) and the nut (113) retain a spacer (114) on the post (44) such that the spacer (114) cannot rotate with respect to the cover (38) and the post (44). For instance, the post (44) is formed with an axially extending slot (not shown) and the spacer (114) is formed with a tab (not shown) which extends into the unillustrated slot in a manner well known to prevent rotation of the spacer (114). A spring (118) is retained between the spacer (114) and a base portion (26a) of the main lever (26). The base portion (26a) has a generally disk-like shape and is integrally formed with the main lever (26). One end (not shown) of the spring (118) engages the spacer (114) and another end (not shown) of the spring (118) engages the base portion (26a) for biasing main lever (26) to a home position (as shown) in FIG. 2). A retainer plate (76) is held in place by the post (44) between the cover (39) and the control member (72), as shown in FIG. 3, such that the retainer plate (76) cannot rotate with respect to the cover (39). It should be understood that the control member (72) and the takeup element (52) are fixed to one another but are rotatable about the post (44) and are rotatable with respect to the cover (39), but the takeup element (52) is biased by the spring (60) in a counterclockwise direction (with respect to FIGS. 4A-4I). A drive pawl (130) is mounted to a drive pivot post (134). The drive pivot post (134) extends through an arcuate slot (not shown) formed the cover (39). The drive pivot post (134) is further fixed to the base portion (26a) such that as the lever (26) is moved, the post (134) moves within the confines of the slot (not shown) in the cover (39). The drive pawl (130) is mounted on the post (134) but may rotate with respect to the post (134). The drive pawl (130) is biased in a clockwise direction (with respect to FIGS. 4a-4I) by a spring (138), and both drive pawl (130) and spring (138) are retained on main pivot post (134) by, for instance, a C-clip (not shown).
FIGS. 4A through 4I are views illustrating the relationship between and the movement of the control member (72), the release pawl (98) and drive pawl (130) with respect to one another. FIGS. 4A through 4I and the following description further show how the control member (72), the release pawl (98) and drive pawl (130) cooperative with one another to selectively move the cable (28) and hence move the derailleur and chain (D) between a plurality of sprockets in a sprocket set, through engagement of the release pawl (98) and drive pawl (130) with the large and small position retaining teeth (80) and (82) and drive teeth (84).
In the embodiment depicted in FIGS. 4A through 4I there are three large position retaining teeth (80a, 80b and 80c), each of the large position retaining teeth positioned to correspond to one sprocket in a sprocket set having three sprockets, such as the sprocket set shown in FIGS. 5A through 5F, the sprocket set having sprockets (S1, S2 and S3) axially spaced apart as shown. Further, there is at least one small position retaining tooth (82f) formed between the large position retaining teeth (80c) and (80b), at least one small position retaining tooth (82e) formed between the large position retaining teeth (80b) and (80a), and a plurality of small position retaining teeth (82a, 82b, 82c, 82d) formed on a counterclockwise side of the large positioning retaining tooth (80a).
Most of the various positions of the control member (72) with the jaw (104) in engagement with one the large and small position retaining teeth (80) and (82) corresponds to at least one of the positions of a derailleur (200) shown in FIGS. 5A through 5F, as is explained below. Each of FIGS. 5A through 5F show two differing sprocket sets, one sprocket set shown in the upper portion of each of FIGS. 5A-5F and another sprocket set shown in the lower portion of each of FIGS. 5A-5F. The first sprocket set includes sprockets S1, S2 and S3. The second sprocket set includes sprockets S4, S5 and S6. The axial spacing between the sprockets S4, S5 and S6 is larger than the axial spacing between sprockets (S1, S2 and S3).
The operation of the shifting apparatus (10) is described below.
When the bicycle transmission is not in the process of being shifted, an engagement projection (140) of drive pawl (130) engages an abutment (144) shown FIGS. 4A through 4F. The abutment (144) is formed on the retainer plate (76) such that the engagement projection (140) cannot engage any of the drive teeth (84) on the control member (72). When the drive chain is to be shifted to the next largest freewheel sprocket, then main lever (26) is rotated in the counterclockwise direction with respect to FIG. 2. The movement of the main lever (26) causes drive pawl (130) to move from the dotted line representation of the drive pawl (130) in FIGS. 4B-4H and in the direction of the drive pawl (130) shown in solid lines in FIGS. 4B-4H so that engagement projection (140) of drive pawl (130) moves radially inward beyond the abutement (144) and drops into the gap between adjacent drive teeth (84) and (84), until engagement is made with one of the drive teeth (84). Once engagement is made with one of the drive teeth (84), the control member (72) is caused to rotate in a clockwise direction in response to further movement of the drive pawl (130).
The takeup element (52) and control member (72) then rotate in the clockwise direction, with respect to FIGS. 4A-4I. Since release pawl (98) is pivotable about the release pivot post (92), release pawl (98) rotates counterclockwise when one of the large position retaining teeth (80b) or (80a) or one of the small position retaining teeth (82a) through (82f) passes by it as the control member (72) rotates in a clockwise direction, thus allowing contacting position retaining tooth to move to the other side of jaw (104). Thereafter, when main lever (26) is release, spring (118) causes main lever (26) to return to the position shown in FIG. 2, and drive pawl (130) retracts to the position shown in FIG. 4A in solid lines and in dotted lines in FIGS. 4B-4H. Since takeup element (52) and control member (72) are biased in the counterclockwise direction by spring (60), engagement jaw (104) and any of the large or small positional retaining teeth prevents the control member (72) from rotating in a counterclockwise direction, thus maintaining takeup element (52) and the derailleur (200) in the desired position.
When the chain is to be shifted, for instance, to a smaller sprocket, release lever (34) is rotated in a clockwise direction, with respect to FIG. 2. The movement of the release lever (34) causes rotation of the pawl (98) in the counterclockwise direction, with respect to FIGS. 4A-4I. Small amounts of rotation of the pawl (98) will retract the jaw (104) from engagement with any of the small teeth (84), and allow the control member (72) to rotate in a counterclockwise direction but will cause the jaw (104) to engage the first large position retaining teeth (880a, 80b or 80c) that approaches the jaw (104). Large movement of the pawl (98), such as that depicted in FIG. 4I, will bring the jaw (106) into position for contact with the first of either large position retaining teeth (80b) or (80c) that approaches the jaw (106), thus causing a downshift movement of the derailleur (200) from one larger sprocket to the next smaller sprocket. Thereafter, release of the release lever (34) will cause the biased pawl (98) to pivot such that the jaw (104) will engage the nearest large positioning tooth on a clockwise side of the jaw (104). Since engagement projection (140) of drive pawl (130) is resting on abutment (144), drive pawl (130) does not interfere with rotation of control member (72) during downshifting.
For example, if the release lever (34) has been completely depressed (a large movement) with the control member (72) in the position shown in FIG. 4C where the derailleur is aligned with the sprocket (S2) as shown in FIG. 5B, the subsequent movement of the pawl (98) and control member (72) will cause the jaw (104) disengage the large position retaining tooth (80b), as shown in FIG. 4I. Thereafter, the jaw (106) will make contact with the large position retaining tooth (80b). When release lever (34) is released, spring (94) causes release lever (34) to rotate back to the position shown in FIG. 1. Since release pawl (98) is biased in the clockwise direction by spring (102), release pawl (98) will rotate in the clockwise direction, and jaw (106) moves up the side of position retaining tooth (80b) until the tip of jaw (106) clears the tip of position retaining tooth (80b). When this occurs, control member (72), which is biased in the counterclockwise direction by spring (60), moves counterclockwise until position retaining tooth (80c) abuts against jaw (104) as shown in FIG. 4A, thus completing the downshifting operation.
With respect to FIGS. 4A through 4I, the drive chain (D) is engaged with the smallest freewheel sprocket (S1) or (S4) in either sprocket set when the position retaining tooth (80c) abuts against jaw (104) of release pawl (98), as shown in FIG. 5A. The drive chain (D) is engaged with the freewheel sprocket (S2) when the position retaining tooth (80b) abuts against jaw (104) of release pawl (98), as shown in FIG. 5B. However, the drive chain (D) is engaged with the freewheel sprocket (S5) when the position retaining tooth (82e) abuts against jaw (104) of release pawl (98), as shown in FIG. 5C, and so on. The positions of the chain derailleur (200) shown in FIGS. 5A through 5F correspond to the positions of the control member (72) depicted in FIGS. 4A through 4I as follows:
1) the position of the derailleur (200) in FIG. 5A corresponding to the position of the control member (72) depicted in FIG. 4A,
2) the position of the derailleur (200) in FIG. 5B corresponding to the position of the control member (72) depicted in FIG. 4C,
3) the position of the derailleur (200) in FIG. 5C corresponding to the position of the control member (72) depicted in FIG. 4D,
4) the position of the derailleur (200) in FIG. 5D corresponding to the position of the control member (72) depicted in FIG. 4E,
5) the position of the derailleur (200) in FIG. 5E corresponding to the position of the control member (72) depicted in FIG. 4F, and
6) the position of the derailleur (200) in FIG. 5F corresponding to the position of the control member (72) depicted in FIG. 4G.
However, it should be understood that the dimensional relationship or axial spacing between the sprockets S1, S2 and S3 and the sprockets S4, S5 and S6 are for example only. Other spacings, number of sprockets and the correspondence between position retaining teeth and sprockets may be varied or altered depending upon design requirements.
In the manner described above, the present invention allows for shifting from a small sprockets such as the sprocket (S1) stepwise to a larger sprocket (S2) with simple motion of the lever (26) using indexing provided by the large position retaining teeth (80c, 80b and 80c). Further, in the event that the shifting mechanism is used with a sprocket set such as the sprocket set having sprockets (S4, S5 and S6) having large axial spacing between the sprockets, the small position retaining teeth (82a-82f) provide additional accurate indexing. For downshifting, the shape of the pawl (98) and the size of the jaws (104) and (106) are such that upon downshifting, movement of the control member (72) will be stepwise between adjacent large position retaining teeth (80a, 80b, 80c) since upon movement of the lever (34) the jaws (104) and (106) will only engage the large position retaining teeth (80a, 80b or 80c) one at a time. Therefore, for upshifting to a larger sprocket, the present invention allows for both large and small positional changes of the control member (72) in accordance with the movement of the drive pawl (130) and the spacing between both large and small position retaining teeth. But for downshifting, the present invention only allows large movements of the control member (72) between adjacent large position retaining teeth (80a, 80b and 80c) for rapid downshifting often required by bicycle riders.
When a bicycle derailleur mechanism is shifted, the amount of displacement of the derailleur may vary depending upon the size requirements of the chain sprockets employed. In a derailleur/freewheel configuration, this is caused in part by the variable distance between successive freewheel gears. In an indexed shifting apparatus, this variable displacement is accommodated by setting the position retaining teeth at different spacing from each other to correspond to the spacing between the sprockets in a sprocket set. However, because various types of sprocket sets are employed currently for front derailleurs, the present invention is necessary for use with a variety of sprockets sets. With the sprocket set shown in the upper half of each of FIGS. 5A through 5F, the large position retaining teeth provide accurate positioning of the derailleur (200). Further, in the same shifting apparatus, may be used with the sprocket set shown in the lower half of each of FIGS. 5A through 5F without modification or alteration.
To further illustrate the present invention, and to show an alternate embodiment, FIGS. 6 and 7 are provided to demonstrate the differences between the present invention and the prior art. FIG. 6 shows a release pawl (300) and a control member (310) from a prior art shifting apparatus. There are four position retaining teeth (380) formed on the control member (310). The first three position retaining teeth (380) correspond generally to three sprockets of a sprocket set. The control member (310) may only be reliably used with a sprocket set whose sprockets are spaced apart in harmony with the spacing of the position retaining teeth (380). No other sprocket set may be reliably be used with the control member (310).
In FIG. 7, on the other hand, an alternate embodiment of the present invention is shown where a control member (72') is shown with a plurality of large position retaining teeth, a plurality of small positioning teeth and plurality of drive teeth. In a manner similar to the above described embodiment of the present invention, the control member (72') may be used with a variety of sprockets sets having various axial spacings between sprockets. The large position retaining teeth may correspond to a popular sprocket set employed on a large number of bicycles, while the small position retaining teeth may correspond generally to a variety of differing sprocket sets where those sprocket sets have axial spacing between sprockets that differs from the popular sprockets set.
Various details of the invention may be changed without departing from its spirit nor its scope. Furthermore, the foregoing description of the embodiments according to the present invention is provided for the purpose of illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. | An apparatus for operating a bicycle transmission shifting device having an operating component for mounting to a bicycle in close proximity to a brake operating unit for alternately pulling and releasing a transmission element, a first lever is mounted to the operating component for movement which causes the operating component to pull the transmission element and second lever is mounted to the operating component for movement which cause the operating component to release the transmission element. The first lever and the second lever are mounted to the operating component so that the brake operating unit is disposed between the first lever and the second lever when the shifting device is mounted to the bicycle. In order to be able to construct the shifting device with only a single pawl for the release mechanism the takeup element for the transmission element includes a control member having a plurality of large and small position retaining teeth for engaging the single release pawl. | 1 |
FIELD OF THE INVENTION
The invention relates to polysaccharide extracted from Antrodia camphorata and the method to prepare it. The invention also relates to composition for hepatoprotective effect.
DESCRIPTION OF PRIOR ART
Antrodia camphorata (Chinese name, niu-chang-chih or niu-chang-ku) is a new species of the genus Antrodia (family poly-poraceae, Aphyllophorales) that is parasitic on the inner cavity of the endemic species cinnamomum Kanehirai Hey . It is endangered species in Taiwan. The fruit body of Antrodia camphorata is perennial and has a strong smell. It differs a lot from general reishi mushroom in its plate-shaped or bell-shaped appearance. The plate-shaped one is orange red (yellow) with ostioles all over its surface and has light yellow white phellem in bottom layer. It grows by adhering phellem to the inner wall inside a hollow Antrodia camphorata . The bell-shaped one also shows orange (yellow) color in fruit body layer (bell surface) that is completely filled with ostioles inside, which are, spores of bitter taste in orange red for fresh state and in orange brown or brown afterward. Bell body is a shell that appears in dark green brown color. The spores look smooth and transparent in slightly curved column shape under the investigation by microscope.
Antrodia camphorata is traditionally used for treatment of toxication caused by food, alcohol or drugs, as well as diarrhea, abdominal pain, hypertension, skin itching and cancer (Shen et al., 2004, FEMS Microbiol. Lett., 231: 137-143). In the past, phytochemical investigations have resulted in the isolation of a series of new steroid acids, triterpene acids and polysaccharides (Lieu et al., 2004, Toxicol. Appl. Pharmacol. 201:186-193).
Polysaccharides are common structural and storage polymers in living organisms, representing more than 75% of the dry weight of plants. Compositional analysis of glycoconjugates is important in structural studies of these compounds. Polysaccharides are potentially useful, biologically active ingredients for pharmaceutical uses due to a variety of biological activities, such as mitogenic activity, activation of alternative-pathway complement (APCs) and plasma-clotting activity (Lee et al., 2002, FEMS Microbiol. Lett., 209:63-67; Chen et al., 2005, Life Sciences, 76: 3029-3042).
The effects of the polysaccharides extracted from Antrodia camphorata are anti-hepatitis B virus effects, anti-inflammatory activity, anti-angiogenic activities and antitumor effects (Lee et al., 2002, FEMS Microbiol. Lett., 209:63-67; Shen et al., 2004, FEMS Microbiol. Lett., 231: 137-143; Chen et al., 2005, Life Sciences, 76: 3029-3042; Lieu et al., 2004, Toxicol. Appl. Pharmacol. 201:186-193). However, the component, structure or other characteristics of the polysaccharides extracted from Antrodia camphorata are not yet clear identified.
Hepatitis is a common disease in the world especially in developing countries. However, there are no effective drugs for the treatment of this disease. In recent years, scientists have carried out a considerable amount of research on traditional medicine in an attempt to develop new drugs for hepatitis. Compounds that can either decrease the necrotic damage to hepatocytes via enhanced defense mechanisms against toxic insult or improve the repair of damaged hepatocyte are considered potentially useful in the treatment of human hepatitis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates elution profile of Antrodia camphorata (ACN) by ion exchange column chromatography on DE-52 (Detection was performed by phenol-H 2 SO 4 method).
FIG. 2 illustrates elution profile of ACN by gel filtration column chromatography on HW-65 (Detection was performed by phenol-H 2 SO 4 method).
FIG. 3 illustrates elution profile of ACN2 by gel filtration column chromatography on HW-65 (Detection was performed by phenol-H 2 SO 4 method).
FIG. 4 illustrates elution profile of ACN2-1 by gel filtration column chromatography on HW-65 (Detection was performed by phenol-H 2 SO 4 method).
FIG. 5 illustrates IR spectrum of ACN2a (measured with KBr method).
FIG. 6 illustrates 1 H-NMR spectrum of ACN2a (measured in D 2 O).
FIG. 7 illustrates 13 C-NMR spectrum of ACN2a (measured in D 2 O).
FIG. 8 illustrates GC-MS analysis of sugar composition of ACN2a.
FIG. 9 illustrates determination of the absolute configurations (D/L) of the component sugars of the ACN2a.
FIG. 10 illustrates the effects of ACN2a on serum AST levels in ICR mice with P. acnes -LPS induced liver injury. Nor: normal control; Con: P. acnes -LPS; A0.8: ACN2a 0.8 g/kg(b.w.)+ P. acnes -LPS; A0.4: ACN2a 0.4 g/kg(b.w.)+ P. acnes -LPS; A0.2: ACN2a 0.2 g/kg(b.w.)+ P. acnes -LPS; FK506: FK506 1 mg/kg(b.w.)+ P. acnes -LPS. The results represent the mean±S.D. of the values obtained 10 mice in each group. *: P<0.05 and **: p<0.01 compare to corresponding P. acnes -LPS control group as determined with student's t-test.
FIG. 11 illustrates the effects of ACN2a on serum ALT levels in ICR mice with P. acnes -LPS induced liver injury. Nor: normal control; Con: P. acnes -LPS; A0.8: ACN2a 0.8 g/kg(b.w.)+ P. acnes -LPS; A0.4: ACN2a 0.4 g/kg(b.w.)+ P. acnes -LPS; A0.2: ACN2a 0.2 g/kg(b.w.)+ P. acnes -LPS; FK506: FK506 1 mg/kg(b.w.)+ P. acnes -LPS. The results represent the mean ±S.D. of the values obtained 10 mice in each group. *: P<0.05 and **: p<0.01 compare to corresponding P. acnes -LPS control group as determined with student's t-test.
FIG. 12 illustrates serum AST levels dependence of hour. Nor: normal control; Con6: the blood samples are collected 6 hrs after intravenous injection of LPS; Con12: the blood samples are collected 12 hrs after intravenous injection of LPS; Con18: the blood samples are collected 18 hrs after intravenous injection of LPS. The results represent the mean±S.D. of the values obtained 10 mice in each group. *: P<0.05 and **: p<0.01 compare to corresponding P. acnes -LPS control group as determined with student's t-test.
FIG. 13 illustrates serum ALT levels dependence of hour. Nor: normal control; Con6: the blood samples are collected 6 hrs after intravenous injection of LPS; Con12: the blood samples are collected 12 hrs after intravenous injection of LPS; Con18: the blood samples are collected 18 hrs after intravenous injection of LPS. The results represent the mean±S.D. of the values obtained 10 mice in each group. *: P<0.05 and **: p<0.01 compare to corresponding P. acnes -LPS control group as determined with student's t-test.
FIG. 14 illustrates serum constituents in mice with P. acnes plus LPS-induced liver injury. In the Figure, N means normal group, C means control group, WE-50 means water extract (50 mg/kg), WE-200 means water extract (200 mg/kg) and C3 means compound 3 of the invention (20 mg/kg).
FIG. 15 illustrates the fractionation of the hot water extract of the Antrodia camphorate.
FIG. 16 illustrates the mechanism of P. acnes -LPS induced hepatic toxicity.
SUMMARY OF THE INVENTION
The invention provides a polysaccharide extracted from Antrodia camphorata having characteristics as follows: (a) appearance: colorless and shapeless powder, (b) pH: neutral, (c) molecular weight: 1285 kDa determined by HPLC as shown in FIG. 4 , (d) rotatory power: [α] D +115.0° (c=0.4433, H 2 O), (e) intrinsic viscosity: [η]=0.0417 dl·g −1 , (f) specific heat Cp: 0.2663 Cal/g·° C., (g) IR spectrum: as shown in FIG. 5 , (h) 1 H-NMR spectrum: as shown in FIG. 6 , (i) 13 C-NMR spectrum: as shown in FIG. 7 , and (j) GC-MS analysis: as shown in FIG. 8 .
The invention also provides a method for extracting polysaccharide from Antrodia camphorata comprising: (a) extracting the Antrodia camphorata by water, (b) collecting the precipitates of the mixture, and (c) dialyzing the TCA-soluble fraction.
The invention further provides a composition for hepatoprotective effects comprises water extract from Antrodia camphorata.
This invention further provides a method for providing hepatoprotective effect comprises administering a patient with an effective amount of water extract from Antrodia camphorata.
DETAILED DESCRIPTION OF THE INVENTION
This invention provides a polysaccharide extracted from Antrodia camphorata having characteristics as follows: (a) appearance: colorless and shapeless powder, (b) pH: neutral, (c) molecular weight: 1285 kDa determined by HPLC as shown in FIG. 4 , (d) rotatory power: [a] D +115.0° (c=0.4433, H 2 O), (e) intrinsic viscosity: [η]=0.0417 dl·g −1 , (f) specific heat Cp: 0.2663 Cal/g·° C., (g) IR spectrum: as shown in FIG. 5 , (h) 1 H-NMR spectrum: as shown in FIG. 6 , (i) 13 C-NMR spectrum: as shown in FIG. 7 , and (j) GC-MS analysis: as shown in FIG. 8 . The IR spectrum of the polysaccharide shows the component sugars comprising galactose, glucose, fucose, mannose and galatosamine. The 1 H-NMR spectrum of the polysaccharide shows the component sugars comprising D-galactose, D-glucose, L-fucose and D-mannose. The ratio of the component sugars comprising galactose, glucose, fucose, mannose and galatosamine is 1:0.24:0.07:0.026:faint. The component sugars have main chain consisting of: (a) terminal residue: fucose or glucose, and (b) middle residue: 1,3-linked glucose, 1,4-linked glucose, 1,6-linked and 1,2,6-linked galactose, wherein the 1,2,6-linked galactose residue is attached by the branch chain at 2-O site. The polysaccharide of this invention has galactose in main backbone and can be linear or branch form.
The polysaccharide of this invention is extracted from Antrodia camphorata by water. The extraction is from mycelium or fruit body of Antrodia camphorata.
This invention also provides a method for extracting polysaccharide from Antrodia camphorata comprising: (a) extracting the Antrodia camphorata by water, (b) collecting the precipitates of the mixture, and (c) dialyzing the TCA-soluble fraction. The step (a) is at around 60-120° C. and the step (b) is left the mixture at around 0-20° C. The precipitates of step (b) are treated with trichloroacetic acid (TCA).
The invention provides a composition for hepatoprotective effects comprises water extract from Antrodia camphorata . In a preferred embodiment of the invention, the water extract comprises the polysaccharide of the invention.
The term “hepatoprotective effect” used in the invention is not limited but to prevent or reduce the hepatocyte necrosis (such as prevention or reducing via scavenging oxygen free radical formation, increasing IL-2, or decreasing cytotoxic T lymphocyte) or against fulminant hepatitis.
The composition further comprises a pharmaceutical carrier, buffer, diluent, or excipient. The suitable diluents are polar solvents, such as water, alcohol, ketones, esters and mixtures of the above solvents, preferably water, alcohol and water/alcohol mixture. For the preferable embodiment, the suitable solvents are water, normal saline, buffering aqueous solution and buffering saline etc. The excipients used with the composition of this invention can be in liquid, semi-liquid or solid form, such as lactose, dextrin, and starch and sodium stearate. Liquid excipients include water, soybean oil, wine and juices etc.
The compositions can be administered by oral or injection. The compositions can be taken by oral in liquid, semi-liquid or solid form. The compositions provided by injection are in liquid or semi-liquid form. The injection includes intravenous injection, the abdominal cavity and intramuscular injection.
The present invention also provides a method for providing hepatoprotective effect comprises administering a patient with an effective amount of water extract from Antrodia camphorata . In a preferred embodiment of the method, the water extract is the polysaccharide of the invention. The administration route is via oral or injection. The polysaccharide can be administered with pharmaceutical carrier, buffer, diluent, or excipient, in liquid, semi-liquid or solid form. The suitable diluents are polar solvents, such as water, alcohol, ketones, esters and mixtures of the above solvents, preferably water, alcohol and water/alcohol mixture. For the preferable embodiment, the suitable solvents are water, normal saline, buffering aqueous solution and buffering saline etc. The excipients used with the composition of this invention can be in liquid or solid form, such as lactose, dextrin, and starch and sodium stearate. Liquid excipients include water, soybean oil, wine and juices etc. The polysaccharide can be taken by oral in liquid, semi-liquid or solid form. The polysaccharide provided by injection is in liquid or semi-liquid form. The injection includes intravenous injection, the abdominal cavity and intramuscular injection.
EXAMPLE
The following examples serve to exemplify the present invention but do not intend to limit the scope of the present invention
Example 1
(A) Materials
Antrodia camphorata mycelium was provided by Simpson Biotech Co. Ltd. (Taiwan). A standard molecular weight market of pullulans (Shodex Standard P-82) was purchased from Showa Denko Co. Ltd., (Japan).
(B) General Experimental Procedures
Optical rotation was determined in H 2 O with a JASCO DIP-360 automatic polarmater. UV absorptions were measured with a SHIMADZU UV-2200 UV-VIS recording spectrometer. IR spectra were recorded in a KBr disk or liquid film using a JASCO FT/IR-230 infrared spectrometer. NMR spectra were recorded on Varian Unity Plus 500 (H was at 500 MHz, C was at 125 MHz) and Varian GEMINI 300 (H was at 300 MHz, C was at 75 MHz). A solution of polysaccharide in D 2 O was measured with 1,4-diozane as an external reference. GC-MS analysis was carried out on a SHIMADZU GC-17A gas chromatography equipped with JEOL mass Spectrometer. TLC was carried out on pre-coated silica-gel 60 F254 plates (Merck, 0.25 mm), cellulose F plates (Merck, 0.1 mm), and spots were detected by spraying with 10% H2SO4 or AHP by heating at 100° C. Carbohydrates were determined by the phenol-H2SO4 method.
Example 2
Preparation of Neutral Polysaccharide from Antrodia Camphorata
(A) Extraction and Fractionation of Polysaccharides
The freeze-dried power of Antrodia Camphorata (1.5 kg) was extracted with CHCl 3 (41×3 times) at room temperature for 1 day, then filtered and dried. The residue was dipped into H 2 O at room temperature for 1 h and extracted (3 times) at 100° C. for 2 h. After the hot water extract were combined and concentrated to 800 ml, and 3200 ml of EtOH was added to the extract. The mixture was stirred and left in the refrigerator for one night. The precipitate was filtered and washed with cold EtOH, then dried. After treatment of the precipitate with 10% trichloroacetic acid (TCA), the TCA-soluble fraction obtained by centrifugation (3000 rpm×10 min) was extensively dialyzed for 3 d against distilled water. The nondialyzed portion was lyophilized to give a brownish residue (AC). Yield: 14.25 g.
(B) Ion-Exchange Column Chromatography of AC
AC (100 mg) dissolved in H 2 O was applied to a column of DE-52 (Whatman international Ltd. England. 2.0×20 cm) The column was eluted with 60 ml of H 2 O, 60 ml of 0.5M NaCl, 60 ml of 1M NaCl, 60 ml of 2M NaCl, and fractions of every 2 ml were collected. H 2 O fraction (ACN) was concentrated and lyophilized to yield 68.3 mg.
(C) Gel Filtration of ACN
ACN (68.3 mg) was dissolved in 0.2M NaCl solution and applied to a column of Toyopearl HW-65 (Tosoh, Tokyo, Japan. 2.0×90 cm). The column was eluted with the same solution, and fractions of every 5 ml were collected. The eluted fractions were separated into two fractions (ACN1 and ACN2) according to the elution profile prepared on the basis of the phenol-H 2 SO 4 method at 480 nm. Yield: ACN1, 19 mg; ACN2, 49 mg. ACN2 was further purified by the column of HW-65 at the same condition as described above. A colorless polysaccharide was got (named ACN2a, yield: 41 mg).
The hot water extract of the Antrodia camphorata was fractionated as shown in chart 1. The non-dialyzable portion (AC) of the 10% TCA soluble fraction had hepatoprotective active and contained polysaccharide because the phenol-H 2 SO 4 reaction was positive. As shown in FIG. 1 , AC was separated by ion-exchange column chromatography on DE-52 cellulose. The most potent water fraction (CAN) was then separated by gel filtration ( FIG. 2 ). The second fraction ACN2a was further purified by gel filtration on HW-65 to yield a colorless polysaccharide (ACN2a) as hepato-protective component ( FIG. 3 ).
Example 3
The Structure Analysis of Neutral Polysaccharide from Antrodia Camphorata
(A) Estimation of Molecular Weight
The average molecular weight of the polysaccharide (ACN2a) was estimated by HPLC analysis. The sample was applied on a TSK-GMPWXL gel filtration column (7.8×300 mm i.d., Tosoh Corp., Tokyo, Japan) and eluted with 0.2M NaCl at 1 ml/min. Commercial available pullulans (Shodex Standard P-82) were used as standard molecular markers.
This polysaccharide (ACN2a) was proved a single fraction by HPLC ( FIG. 4 ), and its apparent molecular weight was estimated to be 1285320 by HPLC. The polysaccharide is colorless and shapeless powder, and has [α] D+115.0° (c=0.4433, H 2 O); Intrinsic viscosity [η]=0.0417 dl g −1 (measured with Ostwald viscometer), and Specific heat Cp: 0.2663 Cal/g° C. (measured by DSC method (differential scanning calorimeter). There are 0.20% protein (measured by Bradford method) and 0.12% nitrogen (by elementary analysis method) in the ACN2a; Sulfate is not present in the ACN2a (measured by Barium rhodizonate method).
(B) Identification of Component Sugars
The polysaccharide (2 mg) was dissolved in 2 ml of 2N trifluoroacetic acid (TFA) and sealed. After being hydrolyzed for 1 h at 125° C. in a steam autoclave, TFA was removed by evaporation of the reaction mixture to dryness. The hydrolysates were reduced with NaBH 4 . Trimethyl-silylation was prepared with silblender-HTP for GC-MS analysis. (Column, DB-1, J&W Scientific, 0.25 mm i.d.×30 m; column temperature, 50° C.˜190° C., 5° C./min; then 190° C., 12 min; Helium carrier flow 4.25 kgf/cm).
According to identification of component sugars ( FIG. 5 ), the polysaccharide consisted of galactose, glucose, fucose, mannose and galatosamine (1:0.24:0.07:0.026:faint). About 62.38% sugar of component sugar is galactose. The rotatory power of ACN2a is +115.0° (c=0.4433, H 2 O). This result suggests that component sugars had a-D- or β-L-configuration possibly (by the isorotation law of Hudson). According to determination of the absolute configuration of component sugars ( FIG. 6 ), the absolute configuration of component sugars was L-fucose, D-galactose, D-glucose and D-mannose respectively.
(C) Determination of the Absolute Configuration of Component Sugars
Determination of the absolute configuration of component sugars was performed as reported by Hara et al. polysaccharide (1 mg) was hydrolyzed in 2N trifluoroacetic acid (TFA) at 125° C. for 1 h. TFA was removed by evaporation to give a sugar fraction. Pyridine solutions (0.5 ml) of the sugar fraction (2 mg) and L-cysteine methyl ester hydrochloride (3 mg) were mixed, and warmed at 60° C. for 1.5 h, then dried with N2. The dried sample was trimethylsilylated with silblender-HTP (0.4 ml) at 60° C. for 1 h. After partitioning with CHCl 3 (3 ml) and H 2 O (3 ml), the CHCl 3 extract was analyzed by GC-MS (Column, DB-wax, J&W Scientific, 30 m×0.25 mm; column temperature, 50° C.˜230° C., 10° C./min; then 230° C., 12 min; Helium carrier flow 4.25 kgf/cm)
(D) Methylation Analysis
The polysaccharide (5 mg) was methylated with methyl iodide by Anumula and Taylor's method. Methylated polysaccharides were hydrolyzed with 4N trifluoroacetic acid (TFA) for 90 min at 125° C. in a steam autoclave. After TFA was removed by evaporation, the hydrolysates were converted to alditols with 1M NH 4 OH containing 3 mg/ml NaBH 4 then acetylated. The partially methylated alditol acetates were analyzed by GC and GC-MS (Column, Sp-2330, Supelco, Bellefnte, Pa., 60 m×0.25 mm, 0.20 um film thickness. Helium was used as a carrier gas, and column temperature was 160° C. to 210° C. at 2° C./min, then 210° C. to 240° C. at 5° C./min and 240° C., 14 min). Peak areas were corrected using published molar response factors. The derivatized compounds were identified by comparison of their relative retention time to 1,5-di-O-acetyl-2,3,4,6-tetra-O-methylglucitol and their GC-EI-MS fragmentation patterns.
In the FT-IR spectrum, as shown in the FIG. 6 , pyranoid form was suggested to be present because of the obserbation of three absorption bands at 1153.22 cm −1 , 1079.94 cm −1 and 1033.66 cm −1 (Furanose form has only two absorption bands in the region). D-Glucopyranose was suggested to be present because of the absorption band at 917.95 cm −1 . In addition, the band at 873.6 cm −1 is a special absorption band of manno-pyranoid and galactopyranoid. Aminosugar was suggested to be present because of the observation of a —NH2 absorption band at 1637.27 cm −1 . It is the same as analysis conclusion of elementary analysis.
In the HNMR spectrum ( FIG. 7 ), H −1 signals were observed at more than 4.8 ppm (4.885, 4.909, 4.963 ppm),which suggest that component sugars have α-configuration. It is the same as analysis conclusion of rotatory power. In addition, at less than 4.8 ppm (4.738, 4.663 ppm), H −1 signals were also observed. This results suggest that component sugars have also little β-configuration. Methyl proton signal was observed at 1.134 ppm, which was assigned to the methyl of fucose residues. Anomeric signal was detected at less than 5.0 ppm as singlet. These results suggest that fucose residue have a β-L-configuration. (Anomeric signal of α-L-fucose was observed at more than 5.0 ppm).
In the CNMR spectrum ( FIG. 8 ), C-4 and C-5 signals were observed at less than 80 ppm. This result suggests that component sugars are pyranoid form (The chemical shifts of C-4 and C-5 for furanose form are present in the region 80˜85 ppm) It is the same as analysis conclusion of IR. In addition, methyl signal was observed at 13.7 ppm, which was assigned to the methyl of fucose residues. This result suggest that fucose residues are L-fucoses (C-6 signal of D -fucose is observed in the region 60˜65 ppm). It is the same as analysis conclusion of HNMR spectrum.
The results of methylation analysis, as summarized in Table 1, showed that ACN2a was composed of terminal-Fucose, 1,4-linked glucose, 1-6 linked and 1,2,6-linked galactose residues, and little terminal and 1,3-linked glucose residues, and little terminal and 1,3-linked glucose residues. By the methylation analysis, ACN2a contained a backbone composed of α-D-1,6-Gal (α-D-1,6- and α-D-1,2,6-) Gal, it is about 72.82%. And the number of branch points were about 15.75% of total residues' numbers, the branch was attached to 2-O of a galactosy residues of the main chain.
TABLE 1
The results of methylated analysis of ACN2a
Methylated
Molar
MS main
Linkages
sugar
ratio
T R
fragments (M/Z)
type
2,3,4-Me 3 -Fuc
0.209
0.789
71, 89, 101,
Fuc-(1→
117, 131, 161,
175
2,3,4,6-Me 4 -Glc
0.084
1
71, 87, 101,
Glc-(1→
117, 129, 145,
161, 205
2,4,6-Me 3 -Glc
0.026
1.31
71, 87, 101,
→3)-Glc-(1→
117, 129, 161,
233
2,3,6-Me 3 -Glc
0.157
1.489
87, 99, 101,
→4)-Glc-(1→
113, 117, 233
2,3,4-Me 3 -Glc
1
1.6
71, 87, 99,
→6)-Glc-(1→
101, 117, 129,
161, 189
3,4-Me 3 -Gal
0.276
1.881
87, 99, 129,
→2,6)-Glc-(1→
189
T R is the relation time of each component, relative to that of 1, 5-O-2, 3, 4, 6-Me 4 -Glc
Example 4
Protective Effect of the Neutral Polysaccharide (ACN2a) Against P. Acnes -LPS Induced Hepatoxicity
(A) Preparation of P. Acbes and Reagent
P. acnes (ATCC 6919) was cultured with brain heart infusion medium (Wako pure chemical industries, Ltd. Osaka, Japan) supplemented with L-cysteine (0.03%) and Tween 80 (0.03%) under anaerobic conditions for 48 h at 37° C. Cultured cells were centrifuged at 7000 rpm for 15 min at 4° C. and washed with Phosphate-buffered saline (PBS). The bacterial pellet was resuspended with PBS and the cells were killed by heat treatment at 80° C. for 30 min, and then lyophilized to prepare the heat-killed P. acnes powder. LPS from Escherichia coli 055:B5 was purchased from Sigma-aldrich, Inc. FK506 (tacrolimus hydrate) was provided by Fujisawa Pharmaceutical Co., Ltd. (OSAKA, Japan).
(B) Animals
To study the protective effect against hepatoxicity induced by P. acnes -LPS, four-week-old male ICR mice (SLC, Japan) weight 18˜20 g were used for the experiment. The animals were acclimatized for one week before the study.
(D) Experiment
The hepatoprotective activity of ACN2a was investigated using: (1) normal control (untreated); (2) P. acnes +LPS; ACN2a [(3) 0.2 g/kg, (4) 0.4 g/kg, (5) 0.8 g/kg of body weight (b. w.)] plus P. acnes +LPS; and (6) FK506 (1 mg/kg of body weight) plus P. acnes +LPS.
Heat-killed P. acnes dissolved in saline was injected via a tail vein at a dose of 0.15 mg/mouse. Seven day later, acute liver damage was induced by intravenous injection of LPS at a dose of 0.05 μg/mouse. ACN2a was given once daily by gastric tube to the animals for 7 consecutive days. On the 8 th day, after 1 h of ACN2a was given, LPS was injected. FK506 was used as positive control drug and administered by gastric tube 48, 36, 24, 12 and 1 hr before intravenous injection of LPS. Blood samples were taken into tubes for analysis of liver injury 6 h after LPS injection, and these animals were sacrificed. The tubes were centrifuged at 4000 rpm for 15 min and the supernatant was used as a sample. All samples were stored at −20° C. until the assay. The serum ALT and AST activity, which are markers of hepatocyte injury were determined using kits for the measurement of enzyme activity (Wako pure chemical industries, Ltd. Osaka, Japan)
FIGS. 10 and 11 showed the effect of ACN2a on ALT and AST levels in serum of mice treated with P. acnes -LPS. The acute hepatoxicity reaction was significantly (P<0.05) suppressed in all of the animals pretreated with 0.4 and 0.8 g/kg of body weight of ACN2a. So ACN2a had protective effect against P. acnes -LPS induced hepatic toxicity in mice; moreover, these protective effect was found to be dose dependent.
Injection of P. acnes followed by LPS is useful for the creation of experimental models of acute hepatic damage. Most of the animals died from severe liver injury within 24 hr of LPS injection. In this study, we found the best dose of P. acnes -LPS (0.15 mg-0.05 ug/mouse). All of animals survived from severe liver injury, and liver injury was the severest 12 hr after intravenous injection of LPS ( FIGS. 12 and 13 ). So in this invention, the blood samples were collected for analysis of liver injury 6 hr after LPS injection.
Example 6
Mechanism of the Hepaprotective Model
Mechanism of the experimental model induced by P. acnes -LPS was shown in chart 2. Injection of P. acnes into mice via a tail vein results in monocytic infiltration of the liver, so hepatic macrophages were increase, and subsequent intravenous injection of a small amount of LPS activated hepatic macrophage. Cytokines of tumor necrosis factor (TNF) IL-1, soluble IL-2 receptor etc., were gone out of hepatic macrophage and increased. Then liver was injured via three ways by these cytokines: 1). TNF and IL-1 broadly necrosised hepatocyte via platelet activating factor (PAF) and leukotriene etc. 2) TNF and IL-1 broadly necrosised hepatocyte via neutrophi and microcirculation lesion. In this way, oxygen free radicals played a major role. 3) IL-2 was decreased because of combining with soluble IL-2 receptor, results in suppressor T cell decreasing and cytotoxic T cell (CTL) increasing. Broad hepatocyte was necrosised by CTL.
The crude polysaccharide of Antrodia camphorata was effective in scavenging oxygen free radical formation and increasing IL-2. In this invention, it was found that both crude polysaccharide and neutral polysaccharide (ACN2a) had protective effect against P. acnes -LPS induced hepatic toxicity in mice. It was conceivable that the polysaccharide of Antrodia camphorata exerted its hepatoprotectie activity by, at least partly, scavenging oxygen free radical formation, resulting in obstructing the 2) way of P. acnes -LPS induced hepatic toxicity or by increasing IL-2, resulting in decreasing CTL and protecting liver.
Example 7
Extraction and Isolation of Antrodia Camphorata
Antrodia camphorata mycelia powder (ACM) (60 g), from Simpson Biotech Co. Ltd., Taiwan, October 2001, were three times extracted with CHCl 3 for 3 h under reflux. The CHCl 3 extract (5.3 g) was chromatographed on silica gel eluted with n-hexane-acetone (19:1-14:6), and CHCl 3 -MeOH (1:1) to give nine fractions (Fr. 1-9). Fraction 2 was chromatographed on silica gel to give compound 1 (8.7 mg). Fraction 4 was chromatographed on normal and reversed phase silica gel to give compound 2 (13.6 mg). Fraction 5 was chromatographed on silica gel eluted with n-hexane-acetone (8:2) to give ergosterol peroxide (35.8 mg). Fraction 6 gave compound 3 (14.6 mg) by combination of normal and reversed phase silica gel column chromatography. Fraction 7 yielded a mixture of compounds 4 and 5 (4:1) by column chromatography. The mixture of compounds 4 and 5 were subsequently separated by preparative HPLC [column: Tosoh TSK-gel ODS-80T M (21.5×300 mm), mobile phase: CH 3 OH—H 2 O containing 0.1% TFA (70:30)].
3-isobutyl-4-[4-(3-methyl-2-butenyloxy)phenyl]-1H-pyrrol-1-ol-2,5-dione (compound 3):
yellow oil; UV (MeOH) λ max (log ∈): 232.5 (4.3), 296 (3.7), 374 (3.7) nm; IR (CHCl 3 ) v max 1717 cm −1 ; 1 H-NMR Table 1; 13 C-NMR Table 2; EIMS m/z 329 [M] + (12), 261 (100), 131 (50); HR-EIMS m/z: 329.1637 (Calcd for C 19 H 23 NO 4 , 329.1627).
Example 8
Protective Effect of Antrodia Camphorata on Fulminant Hepatitis
One of the animal models of human viral hepatitis is Propionibacterium acnes -lipopolysaccharide ( P. acnes -LPS) induced mouse hepatitis. This mouse experimental hepatitis model is widely accepted for studying fulminant hepatitis such as human viral hepatitis. This animal model has been taken to evaluate the protective efficacy of extracts of Antrodia camphorata and compound 3 on fulminant hepatitis. The effectiveness of the chemicals and the extracts was determined by measuring the serum concentration of glutamic oxaloactic transminase (GOT), glutamic pyruvic transaminase (GPT), total protein, and albumin in the hepatitis mice.
Methods and Equipments
Animals
ICR mice were purchased from SLC Co., Ltd. (Shizuoka, Japan). They were kept in an air-conditioned animal room and took water and feed ad libitum. Animal quarantine period was longer than one week.
P. acnes , ATCC 6919, was purchased from Science Research Institute in Saitama Japan. It was cultured in a medium which contains brain heart infusion, L-cystein (0.03%), Tween80 (0.03%) in distilled water under anaerobic condition at 37° C. for 48 hours. At the termination of the culture, P. acnes were spun down at 7000 rpm and 4° C. for 15 minutes. After spinning, the collected P. acnes were re-suspended with PBS and was spun down again. Then the collected P. acnes was suspended again with PBS. The suspension solution was heated at 80° C. for 30 minutes and freeze-dried to prepare powder.
Fractionation of Mycelium of Antrodia Camphorata
Thirty gram of Antrodia camphorata mycelia (Lot #: C071202-1) was mixed with 100 ml chloroform. The mixture was extracted by refluxing at 40° C. for 1 hour. The reflux procedure was repeated three times. All extracts were combined and prepared as freeze-dried powder. The final volume of 4.5 g of powder was obtained. The residue of chloroform extraction was refluxed with 100 ml boiling water for 1 hour. The procedure was also repeated three times. All water extract were freeze-dried.
Administration
The water extract was dissolved in distilled water. The chloroform extract and compound 3 were suspended in distilled water with 4% Tween 80.
Serum Measurement
Sera were separated by centrifugation blood at 3000 rpm, 4° C. for 15 minutes. GOT and GPT were measured by using transaminase CII-Test Wako (Wako Jyun-Yaku Co., Ltd. Osaka). Total protein and albumin were measured by using A/G B-Test Wako (Wako Jyun-Yaku Co., Ltd. Osaka).
Experiment Procedures
The mouse fulminant hepatitis was induced as follows: ICR male mice (8 weeks old) received 0.5 mg of heat-killed Propionibacterium acnes ( P. acnes ) by intravenous injection. On the 8th days after the P. acnes injection, mice were challenged with 0.25 mg of LPS by intravenous injection to induce fulminate hepatitis. Extracts of Antrodia camphorata and compound 3 were given to mice orally by a gastric tube once a day for eight consecutive days right after P. acnes injection. Thereafter, in order to assess the effect of the test substances, mice sera were collected at 18 hours after the LPS challenge.
Results
The survival rate of the control group (mice administered with water) was 30%. Mice that received water extract of Antrodia camphoarata at doses of 200 mg/kg and 50 mg/kg showed survival rates of 60% and 40%, respectively.
The average GOT titer of the control mice was 1662 IU/L, and the average GOT titers of mice treated with 200 mg/kg, and 50 mg/kg water extract were 208 IU/L and 1159 IU/L, respectively. The average GPT titers of the control mice, mice treated with 200 mg/kg and 50 mg/kg water extract of Antrodia camphoarata were 1256 IU/L, 193 IU/L, and 697 IU/L, respectively.
The concentration of total protein and albumin in fulminate hepatitis mice was also reduced in mice treated with water extract of Antrodia camphoarata compared to the control mice. The concentration of total protein of mice treated with 200 mg/kg water extract of Antrodia camphoarata the total protein concentration recovered to the normal level, but not the concentration of albumin.
These experimental results ( FIG. 14 ) suggested that water extract of mycelium of Antrodia camphorata from Antradia camphoarata , have a potent hepato-protective effect against fulminant hepatitis. | The invention relates to polysaccharide extracted from Antrodia camphorata and the method for preparing the polysaccharide. The invention also relates to compositions and methods for hepatoprotective effect. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to a dyeing machine, particularly for dyeing and drying stocking articles and like garments.
As is known, the processing cycle currently followed in stocking dye-houses comprises several steps, and specifically the following ones:
(1) loosening of the blocks delivered by the stocking manufacturer, termed "dozens" or "cakes", which include twelve pairs of stockings in such compressed or compacted conditions as to forbid dyeing with conventional means, and optional application of a band to each stocking dozen in order to hold them together;
(2) introduction of the stocking articles into canvas bags, of a special open mesh stitch type for dyeing purposes, either in number of two or three dozens per charge if the dyeing operation is to be carried out on a mill or turbulence type of machine, or of approximately fifty dozens if the dyeing is to be carried out in a box-type machine, and tying of the bag mouths;
(3) loading of the bags into the dyeing machines, which may be of two types, termed respectively "mill" and "box" or "cabinet";
(4) performing of the dyeing operation, in which the following adverse characteristics can be recognized:
in the mill type, which is characterized by very high values of the bath ratio (i.e. the ratio by weight of the bath made up of water and equalizing, dyeing and softening agents, to the stocking article charge) which may be as high as twenty to twentyfive, there occurs considerable wastage of water and chemicals, when it is considered that the bath is discarded on conclusion of the operation, while a significant amount of steam goes lost to the surrounding atmosphere;
in the box type, similar drawbacks are experienced, although to a smaller extent, while labor requirements are increased owing to the need for manually handling large-size bags, and moreover, there is a risk of disuniformity in dyeing due to the presence of stagnant pockets;
(5) manual unloading of the dyeing machines and transferring of the bags to the centrifugating machines;
(6) performing of such centriguation for a first partial drying of the articles, with attendant risk of excessively string wringing of the stockings and flashing or disuniform dyeing;
(7) completion of the drying step in a special oven;
(8) withdrawal of the stocking articles from the oven, opening of the bags, and reassembling of any dozens which may have come apart;
(9) transfer to warehouses, or to packaging and shipping stations.
The very list of the steps involved provided hereinabove shows what the labor and time requirements of the process can be. Additionally to the cited drawbacks and high consumption of heat connected to the operation of the machines and oven, the high investment cost inherent to the installation of all the machines required should be pointed out.
SUMMARY OF THE INVENTION
It is an object of this invention to make provision for the dyeing and drying of stocking articles by means of a single machine of very simple construction, through direct processing of the cakes delivered by the stocking article manufacturer, and a highly favorable bath ratio of about two.
Furthermore, consequently to the above, an object of the invention is to achieve a significant reduction in the labor (incidentally, only called upon to handle bags of dry material, and accordingly much lighter) and investment requirements, by reducing the work times and eliminating the heat and chemicals wastages which affect the prior art methods.
These objects are achieved by a machine, according to the invention, for dyeing and drying stocking articles and like garments, characterized in that it comprises a vessel adapted to contain the stocking articles to be processed; a plurality of perforated diaphragms arranged horizontally inside said vessel containing the stocking cakes, such as to divide vertically the space included in said vessel and allow the cakes to be stacked in superimposed layers, said perforated diaphragms being provided with driving means adapted to allow the stocking cakes to be loaded into and unloaded from the machine; a tubular element penetrating said perforated diaphragms centrally and extending in said vessel in an axial direction up to the mouth thereof; a driven propeller accomodated in said tubular element; a closing cover detachably affixed to said vessel; inlet and discharge means for the bath; means for heating the bath; and inlet and discharge means for the drying air.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other functional and constructional features of the invention will be better understood from the following detailed description thereof, discussing two preferred embodiments of the invention by way of example and not of limitation.
In the accompanying drawings:
FIG. 1 is a partly sectional view of the invention;
FIG. 2 is a sectional view of the machine taken along the line II--II of FIG. 1;
FIG. 3 illustrates a variation of the invention; and
FIGS. 4 and 5 show technical details of the machine of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIGS. 1 and 2, there is indicated at 1 a vertically extending cylindrical vessel provided with a lower perforated diaphragm 2 located adjacent the bottom portion. The vessel 1 has a central axial channel defined by a tubular element 3 which contains a propeller 4 driven by a motor 5 through a belt 6. The motor 5 is advantageously provided with a reverse gear for reversing the direction of rotation of the propeller 4. Reversal will be carried out, of preference with a programmable rate or frequency.
The reference numeral 7 denotes a cover hinged at 8 to the vessel and equipped with an upper perforated diaphragm 9, which has a central opening 10 at the outlet end of the tubular element 3. On said cover 7, there is provided a fitting 11 for an air inlet duct 12, a bowl 13 for containing a sample of the stocking articles to be treated, a level indicator 14, a seat 15 for the insertion of additives in the bath, a dial 16 of a pressure and temperature gauge, and a gate 17, controlled through a handle 18, which is adapted to close said central opening 10 adjacent the second perforated diaphragm 9.
The cover 7 is connected in sealing engagement to the vessel 1 by means of an edge gasket or seal 19, the closing action being ensured by means known per se, schematically indicated at 20. The numeral 21 denotes a grip or handle for the opening and closing operations, which are assisted by a balancing spring 22 of the cover 7.
There is indicated at 23 a water inlet duct including a gate 24. In the proximity of the latter, there is provided a fitting 25 for connection to a water and air discharge line, which is equipped with a gate controlled through a handle 26. The inlet duct 23 terminates at the fitting 25 upstream of the gate controlled by the handle 26.
For indirectly heating the bath, there is provided a steam-conveying coil 27, while at 28 is indicated a perforated pipe which conveys steam intended to heat the bath directly by admixture.
The numeral 29, finally, denotes one of the bags containing the cakes or dozens of stocking articles, and 30 denotes the level of the water with the vessel filled.
In cooperation, the duct 23 and related gate 24, the fitting 25 with its gate controlled by the handle 26, define said bath inlet and discharge means. The means for heating the bath are defined by the coil 27 and perforated tube 28. The discharge fitting 25 also defines, together with the duct 12, said drying air inlet and discharge means.
Advantageously, the latter further comprise a heating set 44 and related steam feeding pipes 45 and steam discharging pipes 46, steam being used as the heating medium of the set; the suitably heated air performs in a most rapid manner its function of stocking drying.
A further advantageous aspect of this invention resides in that between the first and second perforated diaphragms 2 and 9, there are provided intermediate perforated diaphragms 41 and 42 of perforated metal sheet. These intermediate perforated diaphragms are composed of tiltable portions 41a and 42a, and of cross members 41b and 42b, respectively, which engage with said portions through hinges 43. The cross members 41b and 42b are rigidly connected to the walls of the vessel by means of welds 47. At 48, there are indicated supporting brackets for the tiltable portions 41a and 42a. As visible in FIG. 2, the tiltable portions 41a and 42a have each an arcuate peripheral border having a radius substantially corresponding to the radius of the vessel 1.
The inventive machine operates as follows. Cake containing bags, as delivered by the stocking article manufacturer, are introduced into the portion of the vessel 1 which is included between the two perforated diaphragms 2 and 9, the outer skirt and tubular element 3. To this end, the cover 7 is opened by acting on the handle 21 and with the assistance of the balancing spring 22, such as to lift the second perforated diaphragm 9. Then the tiltable portions 41a and 42a of the intermediate perforated diaphragms 41 and 42 are lifted, and the cakes are loaded in stacked arrangement onto the lower diaphragm 2 and intermediate diaphragms 41 and 42. After dividing the load in superimposed layers not compressed together, the cover 7 is closed and water is introduced through the duct 23 until the level 30 is reached as checked through the indicator 14. Suitable additives are then added to the bath through the seat 15, and steam is fed first through the perforated pipe 28, for a first quick heating of the bath, and subsequently through the coil 27 to carry the heating step further. Lastly, the propeller 4 is activated. The operation of said propeller exhibits the peculiarity of reversing at predetermined intervals the direction of rotation, such as to cause, at one stage, an upward movement of the water in the pipe 3, and consequently a downward flow thereof through the perforated diaphragms and bags, and viceversa at the following stage, thereby a uniform dyeing action is obtained without any risk of flashing. The dyeing operation is controlled through the sample in the bowl 13, and is very quick and effective owing to the charge being divided in spaced apart superimposed layers which facilitates the bath flow.
On completion of the dyeing step described above, during which the gate 17 is in the position shown in FIG. 1, the vessel is emptied by allowing the bath to flow out through the outlet fitting 25 and the discharge pipe. Then the gate 17 is operated until it reaches a position whereat it completely covers the central opening 10, and air begins to be admitted through the duct 12. Said air flows through the bags, picks up moisture from the stocking articles and is discharged through the fitting 25. Here too, the passage of the air is facilitated by the charge being divided into superimposed layers. Advantageously, to enhance the drying effect, the admitted air is preheated by the heating set 44.
Upon completion of the operation, the cover is opened, the bags withdrawn, and the cakes of stocking articles, dyed and ready for storage, extracted therefrom.
FIGS. 3 to 5 illustrate a possible advantageous variation of the machine according to the invention. In this variation, provision is made for the intermediate perforated diaphragms to be reduced to a single middle perforated diaphragm 55, shown sectioned in FIG. 3 at its fixed central crossmember. Furthermore, the first and second perforated diaphragms, indicated at 51 and 52, are now movable and effective to wring the stocking articles contained in the intermediate areas 53 and 54 of the vessel 1. The movable perforated diaphragms 51 and 52 are connected, the former through selector means which will be described in detail hereinbelow and the latter fixedly or permanently, to control the driving means comprising pistons 56 and 57 at the ends of two pluralities of pistons, generally indicated at 58 and 59, depending from the cylinder 60, which are coaxial with the tubular element 3 containing a propeller 4. Said pluralities of pistons define a space portion 62 included between the tubular element 3 and a series of chambers; in fact, the piston plurality 58 define, between the pistons themselves, chambers 63, 64 and 65, and similarly the plurality of pistons 59 define chambers 66, 67 and 68.
FIG. 5 shows the sectioned detail of part of the piston plurality 58: there is indicated at 69 a duct supplying the working fluid to the space portion 62 to cause the pistons to be lifted, while at 70 is indicated a duct, partly contained in the diaphragm 55 and partly formed in the skirt of the cylinder 60, which carries the working fluid to the chamber 63; from said chamber 63, the fluid reaches the chamber 64 through a duct 71 formed in the skirt 72 of the first piston and opening at one end at an annulus 73 formed on the outside of said skirt, and at the other end at an annulus 74 formed on the inside of the skirt.
From the chamber 64, the fluid reaches the chamber 65 through a duct 75, whereas the chambers defined by the piston plurality 59 will be filled, simultaneously with the previously described chambers and in a similar manner, with the fluid supplied through a duct 76.
The operation of this variation of the invention is clear: when it is desired to wring the stocking articles, a unit will supply the working fluid first to the pair of ducts 70 and 76 to cause the movable perforated diaphragms 51 and 52 to move closer to the fixed central middle diaphragm 55, and then to the duct 69 to produce the opposite movement, the operation being repeatable as many times as desired.
Selector means will be next described which are adapted to connect the first movable perforated diaphragm 51, or upper one, to the piston 56 or cover 7 of the vessel. At 78, there is generally indicated a collar affixed to the piston 56 and provided with two annular detents, a continuous lower one 79 and a serrated upper one 80, while at 81 is indicated a serration formed at the edge of the central hole of the diaphragm 51, matching the serration on the annular detent 80. The numerals 82, 83 and 84 denote three rods extending from the cover 7 and formed with an end portion intended to assume a horizontal lay when the cover is closed and match bridges 85, 86 and 87 connected to the first movable perforated diaphragm 51. Finally, there is indicated at 88 a pin connected to the diaphragm 51, which contacts a yoke 89 extending from a pin 90 projecting out of the cover 7 with a portion provided with an operation member 91.
It will be seen how by continuing the rotation in the direction of the arrow with respect to the position shown in FIG. 4, by actuation of the element 91 which causes the yoke 89 to rotate with attendant entrainment of the pin 88 and diaphragm 51, the serrations 81 will engage those on the annular detent 80, while the horizontal portions of the rods 82, 83 and 84 will disengage from the bridges 85, 86 and 87, thereby the diaphragm 51 remains connected to the piston 56 for the wringing step. On completion of the latter step, and as it is desired to raise the cover or lid in order to withdraw the stocking articles, it is apparent that the diaphragm 51 should be connected to said cover or lid, which is obtained by rotating the diaphragm in the opposite direction to the arrow, until the serrations 81 disengage from the serrations on the annular detent 80 and the rods engage with the bridges.
The invention as described is susceptible to many modifications and variations, all of which fall within the scope of the instant inventive concept. For example, all of the operations described hereinabove may be automated. The control or drive means effective to reciprocate the movable diaphragms could comprise a sleeve coaxially arranged with respect to the vessel and connected to the movable diaphragms by means of a right-handed threaded coupling to one diaphragm and of a left-handed one to the other diaphragm, the sleeve being reciprocated rotatively by a suitable mechanism, e.g. a worm and gear arrangement. Moreover, all the details may be replaced by technically equivalent elements. | A machine for dyeing and drying stocking articles and like garments comprises a vessel for containing the stocking articles to be processed, a plurality of horizontally extending perforated diaphragms within the vessel on which stocking article cakes are stacked in superimposed layers, a tubular element penetrating centrally the perforated diaphragms and extending in the vessel in an axial direction up the mouth thereof, a driven propeller within the tubular vessel, a closing cover fixed detachably to the vessel, an inlet and outlet for a processing bath, heaters for heating the bath and an inlet and outlet for drying air. The perforated diaphragms have tiltable portions for allowing loading and unloading operations. | 3 |
FIELD OF THE INVENTION
[0001] The invention relates to the general field of sensing magnetically recorded data with particular reference to very high data densities.
BACKGROUND OF THE INVENTION
[0002] With an ever-increasing data areal density in hard disk drives (HDD), the magneto-resistive (MR) sensor that is used as the read-back element in HDDs is required to have correspondingly better spatial resolution while at the same time achieving reasonable signal-to-noise ratio (SNR). FIG. 1 shows the structure of a generic TMR (tunneling-magneto-resistive) head which is the main MR sensor structure used in state-of-the-art HDD.
[0003] As seen in FIG. 1A , a generic TMR head has top and bottom reader shields 1 and 2 respectively, spaced distance 3 apart, hard bias (HB) magnets 5 on the sides and MR sensor stack 6 located between the reader shields. FIG. 1B shows conventional MR sensor stack 6 that includes free layer (FL) 8 , tunneling barrier 9 , reference layer 10 , anti-parallel coupling layer 11 of Ru, pinned layer 12 , and anti-ferromagnetic layer 13 beneath the pinned layer 12 to provide the pinned field on 12 and 10 .
[0004] Between top shield 1 and free layer 8 is non-magnetic capping layer 7 . The longitudinal magnetization of HB 5 provides a biasing magnetic field within sensor stack 6 to bias the magnetization 81 of free layer 8 in the cross-track direction. In today's hard disk drive, to further increase area data density, increased data linear density along both the down-track and cross-track directions is being developed. For higher track density, read heads with higher spatial resolution in the cross-track direction are required and smaller sensor sizes are needed. However, with smaller sensor size, magnetic noise gets worse as does sensor stability.
[0005] To overcome these magnetic’ noise and reduced stability problems, a stronger HB field is needed, but this also has the effect of making the sensor less sensitive. Furthermore, due to the smaller bit size within the medium, the field from the medium becomes smaller and so higher sensitivity sensors are required.
[0006] Thus, a trade-off exists between lower noise, better stability and higher signal. When solving this problem it is always beneficial to further increase the dR/R of the TMR film. This is, however, very hard to achieve in existing state-of-the-art TMR sensors. An Improved MR sensor design that can enhance the read-back signal without increasing noise and instability, are therefore needed.
[0007] A routine search of the prior art was performed with the following references of interest being found:
[0008] R. Olivier, and A. Satoru, “Magnetic tunnel junction read head using a hybrid, low-magnetization flux guide” see U.S. Pat. No. 6,519,124 B1 (2003). In U.S. Pat. No. 6,873,499, Lee et al. teach that a flux guide abuts the back edge of a read sensor. Dovek et al. in U.S. Pat. No. 6,239,955, show a flux guide on the back end of a MR sensor where the flux guide overlaps the lead and hard bias layers while Wu (in U.S. Pat. No. 7,170,721) discloses a flux guide on the side of a GMR element with permanent magnets surrounding the flux guide.
SUMMARY OF THE INVENTION
[0009] It has been an object of at least one embodiment of the present invention to provide a method for sensing magnetic data stored at densities of 450 TPI and track widths less than 56 nm without increasing noise and instability.
[0010] Another object of at least one embodiment of the present invention has been to provide a device that achieves the foregoing objectives.
[0011] Still another object of at least one embodiment of the present invention has been to also achieve an increased magneto-resistance ratio.
[0012] These objects have been achieved by a partial etching away of the free layer, the removed material being replaced by a magnetic flux guide structure that reduces the free layer's demagnetization field. This in turn reduces the stripe height of the sensor so that the resolution and the read-back signal are enhanced without increasing noise and instability.
[0013] Stabilization of the flux guide is achieved by providing it with its own longitudinal field generated by an additional pair of hard bias magnets or, alternatively, by an exchange structure.
[0014] The resulting device exhibits an on-track signal increase over existing MR sensor structures, enabling less-dependent optimization of sensor stability and sensitivity as well as better performance in densely recorded environments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIGS. 1A-1B illustrate prior art devices
[0016] FIGS. 2A-2E show various views of a first embodiment of the invention
[0017] FIG. 3 compares dR/R for the invention and for a prior art device as a function of magnetic field applied normal to the sensor's ABS.
[0018] FIG. 4A-4C contrast the down-track waveforms of a conventional sensor with those generated by the invention.
[0019] FIG. 5A-5C compares the simulated mag-noise spectrum of a prior art sensor with the invented device for two distances between the free layer and the flux guide.
[0020] FIG. 6 shows the relationship between signal-to-noise ratio and longitudinal bias for the invented device as well as for several prior art designs.
[0021] FIGS. 7 and 8 illustrate two additional embodiments of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] FIGS. 2A-2E show various schematic views of the invention which introduces a novel back edge flux guide (FG) sensor design. The views provided in FIGS. 2A-2E are, respectively, ABS, top-down, cross-sectional (taken at sensor width center), MR stack close-up (similar to the prior art), and three-dimensional.
[0023] FIG. 2A shows that the FG sensor has a conventional MR stack structure 6 including a pair of conventional hard bias magnets (HB 5 ) for biasing free layer 8 , as seen in prior art FIG. 1 . In an important departure from the prior art, a second pair of hard bias magnets (HB 4 ) is provided for biasing FG 14 , the latter being located along the back edge of the sensor stack as shown in FIG. 2B .
[0024] FIG. 2C further details how the FG is located along the back edge of the sensor stack. In prior art designs free layer 8 extends almost all the way to the back edge which results in the large stripe height (SH) 22 . In the present invention, however, FL 8 has been subjected to controlled etching (which may also involve full or partial removal of the MR junction layer 9 ). Consequently, the initially large SH of the FL has been reduced to the much smaller SH of 21 , also as shown in FIG. 2C . This is another important novel feature of the invention.
[0025] After etching at the back end of the sensor stack, tunneling barrier 9 or reference layer 10 is exposed. A thin non-magnetic insulation layer such as alumina is then deposited on this exposed surface, followed by the deposition, and patterning, of the thin FG layer 14 on this thin non-magnetic insulation layer. The edge of FG layer 14 that faces the FL must be separated from the FL back-edge by a distance that does not exceed the thickness of the FL.
[0026] The flux guide's thickness should be similar to the free layer thickness of from 2 to 10 nm with from 4 to 8 nm being preferred. Other properties of the flux guide include:
[0027] a. Hk<˜50 Oe and Hc<˜5 Oe.
[0028] b. Preferred material is Permalloy with Ni(81%)Fe(19%) or CoNiFe alloys with appropriate oftness as the permalloy.
[0029] When FL magnetization 81 rotates in plane, it generates a magnetic field in FG layer 14 which causes magnetization 141 of the FG layer to rotate correspondingly. This magnetostatic interaction is the basic mechanism behind the magnetic flux guide effect since it enables the free layer to undergo a larger magnetization rotation when exposed to the same medium magnetic field it normally experiences. Additionally, as mentioned above, etching the FL also removes the top layer of HB 5 thereby leaving a cavity within which a large FG layer may be located.
[0030] After a second isolation layer has been deposited on FG layer 14 , outer hard bias magnets HB 4 are formed to stabilize the FG layer magnetization. This is followed by the formation of top shield 1 .
[0031] Once fabrication of the sensor is completed, a single HB initialization field is used to orient both the HB 4 and HB 5 magnetizations along the same direction. This will also orient the FL and FG layer magnetizations to be in the same direction once the initialization field has been removed. HB 4 serves mainly to stabilize the FG magnetization but it can also stabilize the HB 5 at the same time. Thus, the sensor may have a thick HB 4 and much thinner HB 5 which is an advantage in narrow read gap applications. FIG. 2E is a schematic three dimensional view of the completed FG sensor.
[0032] Benefits of the Invention
[0033] FIG. 3 shows a simulated transfer curve for comparison between conventional and FG sensor structures. The x-axis is a magnetic field applied normal to the sensor's ABS and y-axis is the sensor's output expressed as % dR/R. Curve 31 is the transfer curve for the conventional sensor shown in FIG. 1 while curves 32 and 33 are transfer curves for the invented FG sensor, with the gap between the ABS and the free layer's back edge being 5 nm and close to 0 nm respectively. The corresponding amplitude gains by the FG structure are 50% and 90% respectively.
[0034] FIGS. 4A-4D shows a simulated on-track read-back signal comparison between a prior art sensor and the invented FG sensor.
[0035] FIG. 4A shows the 1T and 4T down-track waveforms from a conventional sensor ( FIG. 1 ). The percentage numbers above the figure are 1T signal, 4T signal peak-to-peak amplitudes and 1T/4T resolution, the latter quantity being a measure of the sensor response difference between the high and the low frequency regions.
[0036] FIGS. 4B and 4C show the same plots as in FIG. 4A but with the invented FG structure having FG-FL gaps of 5 nm and close to 0 nm respectively. The presence of the FG also enhances the read-back signal by 13% and 30% respectively; for this case the invented sensor has basically same structure as the sensor of FIG. 4A , except for the addition of the FG.
[0037] FIG. 4E shows the off-track amplitude profiles for the prior art sensor and for the invented FG sensor with a FG-FL gap of 5 nm or 0 nm. The profiles have been normalized to the on-track signal amplitude. The width of the profiles is a measure of the cross-track resolution of the sensor. The full-width at half-maximum is ˜16 nm for all three conditions, indicating that the invented FG sensor has the same cross-track resolution as a conventional prior art sensor having no FG.
[0038] FIG. 5A shows the simulated mag-noise spectrum of a prior art sensor while FIGS. 5B and 5C show the same spectrum from the invented FG sensor with FG-FL gaps of 5 nm and 0 nm respectively. As can be seen, relative to the prior art sensor, the invented FG sensor's major mag-noise peaks have moved to lower frequency, indicating an effectively lower hard bias field. Also, the secondary lower amplitude peaks that appear at the lower frequency of 6-7 GHz derive from a FG magnetization resonance mode. However, the overall SNR, calculated from the ratio of 1T signal power as in FIG. 4 divided by the integrated mag-noise power in the 0-2 GHz range still shows an increase over the conventional sensor case for a FG-FL gap of 0 nm.
[0039] For a more realistic comparison, FIG. 6 shows the simulated SNR for a prior art sensor and for several FG sensors having different structural and HB conditions. The x-axis shows the sensor signal amplitude increase over that of a conventional sensor with HB Ms=700 emu/cc, track width (TW)=30 nm and SH=30 nm. The y-axis is the SNR calculated by using 1T signal power as in FIG. 4 , mag-noise power integrated from 0-2 GHz of spectra in FIG. 5 and Johnson white electrical noise within the same frequency range.
[0040] Discussion
[0041] For a conventional sensor, an amplitude increase can be the result of a HB strength reduction, i.e. lower HB Ms as in various cases in FIG. 6 , and also from larger SH used to enhance SH direction sensitivity. However, in FIG. 6 curve 61 (conventional sensor) shows the SNR saturating at ˜33.5 dB due to a strong mag-noise increase at low HB and large SH which offsets the amplitude gain. For the invented FG sensor structure, amplitude is by reduced SH, reduced FG-FGL gap and lower HB Ms. Curve 62 in FIG. 6 corresponding to SNR vs amplitude increase of FG sensors breaks through the dashed line of curve 61 for an effective SNR gain over a conventional sensor.
[0042] Note that the prior art [1] also mentions a FG type of sensor structure that utilizes a large flux guide layer, which either also serves as the free layer or is exchange coupled to the free layer, while positioning the reference layer and pin layer structure at the back-end of this FG layer. The draw-back of this prior art design is the lower SNR when compared with the FG sensor design of the present invention. Flux leakage while traveling along the prior art FG is major source of signal loss. Additionally, for the narrower FG structure of the prior art, the weak stabilization of the ABS end FG magnetization by HB will lead to large mag-noise from the FG structure as well.
In Summary
[0043] The advantages of the disclosed FG MR sensor are:
1. An on-track signal increase over existing MR sensor structures 2. Enabling less-dependent optimization of sensor stability and sensitivity 3. Better performance for denser MR sensor.
EMBODIMENTS
Embodiment 1
[0047] The structure shown in FIG. 2 .
Embodiment 2
[0048] The same as Embodiment 1 except that HB 4 as in FIG. 2 is in physical contact with HB 5 and FG layer 14 . In this way, HB 4 stabilizes FG layer and HB 5 through direct exchange coupling.
Embodiment 3
[0049] The same as Embodiment 1, except that HB 4 is no existent and FG 14 edge magnetizations are stabilized by synthetic-anti-ferromagnetic (SAF) structures. Layer 21 is Ru layer and layer 22 is another magnetic layer with opposite magnetization to FG 14 and forms SAF structure with FG 14 edge magnetization
Embodiment 4
[0050] The same as Embodiment 3, except that another anti-ferromagnetic layer (AFM) 23 exists on top of layer 22 . AFM layer 23 stabilizes SAF structure composed of layer 14 , 21 and 22 through exchange coupling at the two edges of FG 14 . | An MR sensor, and a method for making it, is described. Part of the MR stack, from the free layer on up, is removed and then replaced by a flux guide. Additional stabilizing means for this flux guide are provided, either as hard bias or through exchange coupling. | 8 |
FIELD OF THE INVENTION
The present invention relates to diffusion bonding, and more particularly to the diffusion bonding of alloy materials having plate or irregular shapes.
BACKGROUND OF THE INVENTION
As explained in our U.S. Pat. No. 4,732,312, which issued on Mar. 22, 1988, the combined use of superplastic forming and diffusion bonding (SPF/DB) offers the potential to manufacture lighter and less expensive aircraft structures than those made by conventional means. It is particularly attractive for sheet metal structures because part and fastener counts could be reduced, thereby significantly decreasing assembly labor. Also the fabrication of structures to near-net shapes using SPF/DB technology can improve material utilization and reduce machining time and costs.
The application of SPF/DB to titanium alloys has been well demonstrated but this is not the case for advanced high strength aluminum alloys. Although impressive SPF behavior has already been demonstrated for aluminum alloys, such as 7475, and work has begun on developing superplastic properties for Al-Li alloys, the diffusion bonding technology for these materials is lagging. A simple and cost-effective diffusion bonding technique compatible with SPF technology could significantly advance the use of aluminum structures.
In diffusion bonding, flattening of the abutting surfaces is necessary in order to achieve intimate interfacial contact. Metals like titanium, which have surface oxides that easily dissolve in the metal during heating, can be readily diffusion bonded without the use of special surface preparations or interlayer diffusion aids. Unlike titanium, aluminum and its alloys (as well as, for example, zirconium and vanadium and their respective alloys) form insoluble oxides which do not readily dissolve during bonding and thus act as barriers to intimate metal-to-metal contact and subsequent diffusion.
Typically, aluminum has been diffusion bonded by methods which rely upon considerable deformation (up to 60 percent) and pressure (up to 40,000 psi) to rupture surface materials to dissolve oxides and aid diffusion. In general, such methods are not compatible with the constraints imposed by SPF technology or the mechanical property requirements of a high performance structure.
For example, practical limitations set by production equipment dictate that SPF pressures probably should be limited to 1,000 psi and perhaps should be much lower. In addition, other variables important to SPF, such as starting microstructure, dwell time, forming rate, dynamic recrystallization, and post heat treatment must be considered.
Aluminum has also been diffusion bonded by removing the surface oxide layers by sputtering or other suitable techniques in a hard vacuum or reduced pressure inert gas environment in order to prevent the oxide layer from being formed again before bonding. However, pressures below 10 -9 Torr must be maintained in order to keep the oxide layer from forming again almost instantly in a hard vacuum and pressures of approximately 10 -6 Torr in an inert gas environment are desirable. In other words, using these techniques, the cleaned surfaces cannot be exposed to air prior to bonding. It is generally believed that cleaning techniques such as abrading, chemical etching or dissolving the oxide by use of fluxes, if carried out in a vacuum or low pressure inert gas environment, to preserve the oxide cleaned surface, present problems in controlling removal of oxides from the work, etching solutions or the process chamber.
In our U.S. Pat. No. 4,732,312, a method is discussed for achieving diffusion bonding of surface layers of an alloy sheet, such as aluminum, having surface oxide coatings of low solubility in the alloy. The discussed method comprises the steps of: treating said alloy so that at least the surface layers to be bonded have a fine grain structure; removing existing surface oxide coatings from the surface layers to be bonded; diffusion bonding the surface layers to one another by placing the alloy to be bonded under a pressure sufficient to cause disruption of the oxide coatings and insufficient to cause macroscopic deformation of the alloy, while heating the alloy in a non-oxidizing atmosphere for a time sufficient for diffusion bonding to occur. Generally, the deformation will approach zero percent or a very low amount on a macroscopic scale. Pressures of less than 1,000 psia and preferably less than 100 psia may be applied to force the surfaces together. The diffusion bonding generally takes place at temperatures below the melting point of the alloy by several degrees centigrade or at the superplastic forming temperature for a time ranging between one and ten hours. At least one part of the diffusion bonded assembly may be superplastically formed to produce a structurally useful component of a predetermined configuration.
More important to the present invention, the method of our mentioned patent may also comprise the step of treating alloy sheets so that the alloy, or at least the surface layers thereof, have a fine grain structure of the type associated with superplastic forming properties. This is done by thermomechanically processing the surface layers of the sheets by heated rollers. Enhanced localized surface deformation of such alloys during bonding resulting from the superplastic microstructure leads to extensive oxide film disruption, thus facilitating bonding.
After diffusion bonding (and superplastic forming) the bonded structure may be further heat treated by solution treating, quenching and aging.
The surfaces to be bonded are prepared by abrading with successively finer grades of grinding paper, rinsing with water, abrading with a metallic brush, and removing the brushings. The abrading may be performed by abrading in a first direction, and abrading in a second direction substantially at right angles to the first direction. The brushings may be removed by exposing the surfaces to a stream of filtered compressed air moving at a velocity sufficiently high to remove the brushings.
Pressure may be applied to the components to be bonded by forcing the surfaces together by placing the components in a fixture, exposing a first opposite surface to a first surface layer to be diffusion bonded to one of a partial vacuum and a pressurized gas and exposing a second opposite surface to a second surface layer to be diffusion bonded to another of said partial vacuum and pressurized gas.
Although the method of our patent achieves success with sheet materials, thermomechanical rolling of thick plates, bars, and irregularly shaped alloy materials is impractical or impossible, thereby preventing surface treatment of these materials to achieve surface fine grain structure of the type associated with superplastic microstructure.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
The present invention is directed to an improvement of the surface treatment disclosed in our mentioned patent. Whereas that application was directed to treating at least the surface layers of sheet material with thermomechanical means, a need still exists for creating a surface microstructure in alloy materials, such as aluminum, which are fabricated in thicker plates or irregularly shaped objects. The improvement of the present invention is centered about the discovery that the surface layers of alloy materials having any shape may be modified by a basic two-phase method including cold working mechanical deformation followed by a heat treatment to produce a fine-grained microstructure that will enhance diffusion bonding. The great advantage of such a method is that it could permit superplastic conditioning of thin surface layers for subsequent diffusion bonding of practically any metallic material and for components in virtually any size or shape. This could lead to the fabrication of unique hybrid structures wherein the main thickness of the material is not fine-grained and superplastic while the near surface layers are fine-grained and superplastic.
BRIEF DESCRIPTION OF THE FIGURES
The above-mentioned objects and advantages of the present invention will be more clearly understood when considered in conjunction with the accompanying drawings, in which:
FIG. 1 is a graphical plot of two alloy samples comparing grain size with bond strength;
FIG. 2A is a schematic illustration of a first phase of the present method wherein a surface microstructure is cold worked;
FIG. 2B is a schematic illustration indicating a subsequent phase of the present method wherein thermal treatment produces a fine grained surface layer structure by recrystallization;
FIG. 3A is a diagrammatic sectional view illustrating the diffusion bonding between refined grain structures at the interface of extrusions and a baseplate;
FIG. 3B is a diagrammatic cross-sectional view illustrating diffusion bonding between a fine-grained superplastic sheet and a fine-grained region in the surface layer of a baseplate.
DETAILED DESCRIPTION OF THE INVENTION
The proposed invention is a method for fabricating diffusion bonded or superplastically formed and diffusion bonded (SPF/DB) structures, wherein any metal or alloy, which may or may not be initially superplastic, is joined at selected areas by diffusion bonding. According to such method, the metal or alloy to be diffusion bonded is first subjected to a prescribed surface treatment for the purpose of modifying its surface properties. The modification involves cold working mechanical deformation of the surface. Such treatment results in a deformed microstructure ready for recrystallization. The mechanical deformation is followed by a thermal treatment to finalize a fine grain structure in a surface layer. The mechanical deformation may be accomplished by hammering or shot peening which cold works the microstructure in the surface layer while ensuing thermal treatment produces recrystallization to produce the desirable fine grained structure in the surface layer. Control of the shot size, density and impingement force will result in an optimized microstructure which is suitable for subsequent diffusion bonding. As a result of the dual step method of the present invention, a thin layer of fine grain, superplastic material can be produced in an otherwise non-superplastic material Similarly, a thin metastable surface layer will subsequently undergo transformation to a desired microstructure either before or during the thermal cycle imposed by diffusion bonding. Diffusion bonding will be greatly enhanced in surface modified materials because of improved flow and contact of the mating pieces. Furthermore, in metals with stable oxides, such as aluminum and its alloys, diffusion bonding will be further enhanced after surface modification because of increased surface movements during bonding which lead to the disruption and break-up of surface oxides.
FIG. 1 indicates two graphical plots to dramatize the bond strength increases with fine grain size. Each of the plots represents a separate sample of 7475-T6 aluminum alloy. Each plot illustrates the linear increase of shear strength (bond strength) as a function of smaller grain size.
The present invention recognizes the desirability for achieving fine grain size near the surface of alloy material and overcomes the previous limitation that such fine grain size associated with superplastic alloy materials could only be achieved with relatively thin sheet materials.
FIG. 2A schematically illustrates an alloy block 10 which is not superplastic as supplied. Thus, the alloy is comprised of relatively large grains, as indicated by reference numeral 12. In order to produce a fine grained layer near the surface of the plate, the present invention utilizes two principal steps. In FIG. 2A, mechanical deformation of a surface layer is illustrated. More particularly, plastic deformation of the surface layer is accomplished at room temperature which causes strain hardening and a cold-worked, distorted microstructure. Although a shot peening source 14 is illustrated in FIG. 2A, other alternatives may include forging, swaging, cold rolling, coining, and hammering.
Subsequent to the metal deformation is the application of heat which will induce recrystallization leading to a new fine-grained, strain-free material at the surface of the block 10. The grain refinement resulting from this method corresponds to a superplastic surface condition. The refined grain microstructure resulting at the end of the present method is schematically illustrated at the surface 18 by reference numeral 20.
In a preferred embodiment of the present invention, the metal deformation of the block surface is produced by shot peening source 14 which directs a flow of shot at the surface 18 of the plate. In order to move the energy source 14 relative to the plate surface 18, it is possible to utilize a conventional numerical control device 22, such as is prevalently utilized in robotics and machine tool controls. In the case of a flat block 10, as shown in FIG. 2A, the control device need move the energy source 14 at a constant speed across the surface 18 so that each point receives substantially the same amount of shot from the source. Alternatively, the block 10 may be moved relative to a stationary source 14. This would typically involve a movable table (not shown) upon which the block rests. The table would be moved in the x-y plane by a numerical control device such as 22. This will result in a desirable uniform grain reduction along a surface layer. Thus, in such an application the shot source and plate need only undergo relative translational motion along x and y coordinates. Routine experimentation is necessary to determine the shot size, density and impingement force necessary to achieve a cold-worked microstructure in the surface layer of the block.
After this occurs, the next phase of the method is followed as indicated in FIG. 2B wherein the plate is heated to cause recrystallization of the deformed layer. The heating can be achieved by any conventional heat source and the time and temperature may be determined by routine experimentation wherein recrystallization of the deformed layer is observable. Of course, if just a small area of the surface is to be treated, the entire block need not be subjected to heat. It should also be mentioned that the heat treatment may occur either before or during the diffusion bonding process.
The significant advantage of the present invention is that it is capable of operating with various alloys, whether they are supplied as a superplastic, or non-superplastic material A still further significant advantage is the ability of the present invention to refine the grain in an alloy object having almost any shape and thickness. Of course, in the event a non-planar object is to be worked upon, the numerical control device 22 must be capable of undergoing three-dimensional motion along x, y and z coordinates. Many types of appropriate numerical control devices for accomplishing these ends are commercially available.
As a result of the method of the invention, the surface is modified as a result of two major steps, the first being mechanical deformation of a surface layer and the second being heat treatment for recrystallization of the deformed layer. Such treatment results in the formation of microcrystalline or metastable phases, depending on structural and kinetic factors. The result of the method is the production of a thin layer of fine grain, superplastic material in an otherwise non-superplastic material Diffusion bonding will be greatly enhanced in surface modified materials because of improved flow and contact of the mating pieces. Furthermore, in metals with stable oxides, such as aluminum and its alloys, diffusion bonding will be further enhanced after surface modification because of increased surface movements during bonding which lead to the disruption and break-up of surface oxides.
FIGS. 3A and 3B are diagrammatic sectional views of structures indicating the regions which achieve diffusion bonding. In FIG. 3A a baseplate 24 has several parallel spaced extrusions 26 mounted thereto. The mounting is accomplished by diffusion bonding between a baseplate 24 and a plurality of parallel spaced extrusions 26. More particularly, a fine-grained region 28 in each extrusion 26 is brought into diffusion contact with a mating fine-grained region 30 in the baseplate 24. Diffusion bonding between these fine-grained regions will occur at interface 32.
Similarly, diffusion bonding may be achieved between a fine-grained superplastic sheet 36 and baseplate 34. The diagrammatic cross-sectional view of FIG. 3B indicates that the sheet 36 is characterized by a fine-grained superplastic body 38. Several spaced fine-grained regions 42 characterize the upper surface of plate 34 and the intention is for base sections of the sheet 36 to contact (40) the fine-grained areas 42 of the base so that diffusion bonding therebetween may be realized.
It should be understood that the invention is not limited to the exact details of construction shown and described herein for obvious modifications will occur to persons skilled in the art. | Diffusion bonding of aluminum alloy objects of different sizes and shapes may be greatly improved when the surface of the object is exposed to a mechanical deformation cycle which forms a cold-worked surface microstructure, followed by a heat treatment cycle to produce recrystallization of the surface layer. The method of the invention results in the formation of finer grains at the surface which enhances the strength of a diffusion bond. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of PCT application U.S. Ser. No. 94/01940, international filing date Feb. 23, 1994.
BACKGROUND OF THE INVENTION
This invention concerns the generation of signals corresponding to the torque produced by an internal combustion engine. The measurement of torque produced by an engine is generally carried out in a test cell using elaborate and expensive equipment and is time consuming. It is difficult to monitor torque under actual running conditions such as in an automobile. Measurement of spring resisted deflections in the drive line of a transmission mechanism have been developed but none of these have been particularly adapted to detect engine torque under running conditions in an automobile.
Internal combustion engines power practically every kind of mobile machine from automobiles, trucks, tractors, tanks, boats, seagoing vessels, airplanes, air compressors, and lawn mowers. Electronic control systems are now extensively used in automobiles to monitor and manage engine functions because they have proven to be cost effective and reliable and have improved the function, performance, reliability, and efficiency of automobile engines in ways unrecognizable even a decade ago. Very few automobiles are produced without a microprocessor on board.
It would be advantageous to provide an engine torque sensing device generating electronic signals during operation of the engine so as to be able to process signals for further use in these microprocessors. For example, when engine torque and engine speed are monitored, they are together proportional to engine horsepower which could then be readily displayed on the instrument panel of a vehicle and could warn the driver, in an open loop system, to carry out a certain function such as changing gears. More importantly, it could in a closed loop system automatically shift the gears of automatic transmissions when working with the other inputs currently employed to improve the efficiency and shift quality.
A torque sensing device could also be adapted to sense the degree of overrun which occurs such as when a diesel truck is descending a hill and the engine overspeeds. A retarder could automatically be activated in conjunction with other inputs to slow down the vehicle.
On farm tractors, torque sensing devices are sometimes used to raise or lower a tillage implement just sufficiently to maintain tractor speeds when the soil or terrain conditions vary. When climbing slopes they can downshift a power shift transmission. The device also senses the torque fluctuations in a power-take-off drive (P. T. O.) and when the crop fed into a forage harvester gets too large, downshifting a power-shift transmission can take place until the adverse conditions pass.
Engine horsepower testing is generally carried out in a test cell and the results obtained often vary from those actually realized in a vehicle because the air intake systems, the cooling systems, and the exhaust systems are seldom similar. An electronic torque device could read out the horsepower actually occurring and would be advantageous in monitoring engines for maintenance tune-ups, classification, and regulatory tests.
For instance, farm tractor P. T. O. power and drawbar horsepower are checked at the University of Nebraska test station at Lincoln before the tractor can be sold, and also in several other locations around the world. It would be advantageous to be able to read the horsepower at the flywheel and compare it with the P. T. O. horsepower and drawbar horsepower so that the drive line efficiencies could be determined. In the field, the overall work efficiency could be continuously monitored by comparing the flywheel horsepower with the drawbar horsepower which can be easily measured when pull type implements are coupled to the tractor drawbar.
Torque sensing during engine running as described could be used to improve the function and efficiency of a wide variety of machinery which is power driven by internal combustion engines to an extent not possible today.
Further, U.S. Pat. No. 4,592,241 describes elastic blade type members to transmit torque between a first rotating member and a second rotating member, and these members are shown mounted singly in close fitting slots at both their inner and outer ends. This arrangement would cause the springs to bind in the slots and cause severe fretting corrosion at the end of each spring and where they exit the slots due to the radial movement occurring during deflection under torsional loads. They can also tilt sideways and bind causing more friction. Further, the deflection of these members would be extremely small and difficult to accurately detect. Also, the binding of the spring members in the slots during loading and unloading of the springs would cause high hysteresis and would not result in a straight line relationship between torque and angular deflection of the flywheel pieces as shown in FIG. 4 of the patent. Embodiments shown in FIGS. 5-8 of that patent would result in even smaller deflections for the detectors to pick up.
U.S. Pat. No. 4,135,390 attempts to signal engine torque by having a pair of detectors measuring the differential in movement at the inner and outer ends of a series of spokes formed in the face of a flex plate connecting an internal combustion engine to the torque convertor housing of an automatic transmission. As with the embodiments in U.S. Pat. No. 4,592,241, the deflections under the sensors are extremely small and parasitic forces caused by temperature variations would cause inaccurate torque signals to be sent to the microprocessor.
The object of the present invention is to provide engine torque sensing by an arrangement incorporated into the engine-transmission drive connection which overcomes the disadvantages of the arrangement shown in U.S. Pat. Nos. 4,592,241 and 4,135,390.
SUMMARY OF THE INVENTION
The above-recited object of the present invention, and other objects which will become apparent upon a reading of the following specification and claims, is accomplished by arrangements in which blade springs sets are incorporated in the engine-transmission coupling to allow relative angular displacement proportional to engine torque.
A first embodiment of the invention comprises an arrangement incorporated in the components by which engines are directly coupled to automatic transmissions, including a torque converter such as in current use in automobiles with both front and rear wheel drives, as well as in trucks, buses, off-road, and military vehicles.
In this first embodiment of the invention, the spring coupling is integrated into a flexplate commonly employed to connect an engine crankshaft to a torque converter housing. The flex-plate is formed with a series of arcuate slots through which freely pass stepped diameters formed on internally threaded bushings (or externally threaded studs) attached to the torque converter housing, each of which receive a threaded fastener such as a bolt passing through the flex-plate and into the internal thread of a respective bushing or nut received over a stepped diameter stud. The stepped diameters allow the flex-plate to have an endwise clearance with the torque converter housing so that the flex-plate and torque converter housing can freely rotate relative to each other to an extent limited by the stepped diameters contacting the ends of the arcuate slots in the flex-plate after the threaded fasteners are tightened. The flex-plate no longer transmits torque from the crankshaft to the torque converter.
In this embodiment, torque is transmitted by a plurality of blade shaped springs arranged in sets and anchored firmly in radial slots formed in a hub attached to the flex-plate so that they extend radially outwardly from the slots. The spring blade sets are received between pairs of contact rollers, which turn on pins connected to a driven disc which is bolted against the front side of the flex-plate near its outer diameter by the bolt fasteners connected to the torque converter housing during assembly.
Torque from the engine or reverse torque from the wheels of the vehicle during overrun such as during braking will deflect the spring blades either direction from their no load positions to an extent determined by the amount of circumferential clearance that the stepped diameters of the bushing fasteners have with the width of the arcuate slots. This limitation of the relative motion between the torque converter housing and the flex-plate allows the maximum bending stress in the spring blades to be kept to safe limits for infinite life in service.
The spring blades are preferably of the same commercial grade of spring steel from which valve springs are made are fixedly anchored at their inner ends to make them resistant to the effects of centrifugal force and torsional oscillations and sideways tilting and during deflection they contact rollers to reduce friction, wear, and hysteresis during loading and unloading from the no load position.
To ensure that the angular deflection detected between the flex plate and the torque converter housing is sufficiently large for the sensors to send accurate and easily decoded signals to the on board microprocessor, more than one spring blade can be accommodated if necessary in each slot. For instance, sets of three thin blades may be arrayed about the axis of the flex plate. For example, twelve sets of three blades totalling thirty-six spring blades may be employed. In this case, the deflection will be 1.73 times greater than if twelve thicker spring blades were used.
To complete the sensing of torque, suitable slots or other features are formed on the peripheries of the flex plate and the torque converter housing to be sensed by position sensors, the electrical output signals are directed to on board microprocessors to be used to control such as ignition timing, air-fuel ratios, gear selection, etc.
The second embodiment comprises a two-member flywheel, with a first member fixed to the engine crankshaft. A second member has mounted thereto a series of bearing rollers circumferentially spaced about the axis of rotation, with the first member supporting the second member by the rollers for free limited rotation to minimize friction and hysteresis in relative angular movement of the two members. A pin and slot interconnection between the first and second members defines the limits of relative rotation.
A series of spaced spring engaging rollers are also provided receiving the free ends of blade spring sets fixed to a hub attached to the first member in essentially similar fashion to the first described embodiment.
In a third embodiment where neither a friction clutch or a close-coupled torque converter is used, a separate disc type torque sensor is connected to a one-piece flywheel. The spring coupling means includes two thin metal discs spaced apart by stepped spacers and they drive an interposed driven member by a connection allowing a limited angular distance against the resistance of a series of blade spring sets fixed at their inner end and their outer free ends received between roller sets.
A fourth embodiment shows a further way to connect the front and second member of a two-member flywheel to each other.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary sectional view taken along the line 1--1 in FIG. 2 of a coupling connection between an engine transmission and a torque converter incorporating the torque sensor arrangement according to a first embodiment of the present invention, together with a block diagram representation of an associated microprocessor and a utilization device.
FIG. 2 is a fragmentary sectional view of the section taken along the line 2--2 in FIG. 1.
FIG. 3 is a fragmentary sectional view taken along the line 3--3 in FIG. 2.
FIG. 4 is a fragmentary sectional view of an alternate displacement sensor arrangement.
FIG. 5 is a fragmentary sectional view taken along the line 5--5 in FIG. 6 of a flywheel clutch engine connection incorporating a torque sensor arrangement according to a second embodiment of the present invention, with a block diagram representation of an associated microprocessor and utilization device.
FIG. 6 is a fragmentary sectional view taken along the line 6--6 in FIG. 5.
FIG. 7 is a fragmentary sectional view taken along the line 7--7 in FIG. 6.
FIG. 8 is a fragmentary end view taken in the direction of the arrows 8--8 in FIG. 5.
FIG. 9 is a fragmentary sectional view taken along the line 9--9 in FIG. 10 of coupling connection between a flywheel and transmission incorporating a torque sensor arrangement according to a third embodiment of the present invention.
FIG. 10 is a fragmentary sectional view taken along the line 10--10 in FIG. 9.
FIG. 11 is a fragmentary sectional view taken along the line 11--11 in FIG. 12 through a two-piece flywheel of an alternate design from that shown in FIGS. 5-6, which also incorporates a torque sensor arrangement according to the present invention.
FIG. 12 is a fragmentary sectional view taken along the line 12--12 in FIG. 11.
FIG. 13 is a fragmentary sectional view of an alternate form of the roller shown in FIGS. 11 and 12.
DETAILED DESCRIPTION
In the following detailed description, certain specific terminology will be employed for the sake of clarity and a particular embodiment described in accordance with the requirements of 35 USC 112, but it is to be understood that the same is not intended to be limiting and should not be so construed inasmuch as the invention is capable of taking many forms and variations within the scope of the appended claims.
Referring to FIGS. 1, 2, and 3, the first embodiment of this invention provides a torque sensor arrangement operating between an engine flex plate 1 and a torque converter housing 2. In this depiction, the flex plate 1 is attached to a driving hub 3 by rivets 4 which is connected to the crankshaft 5 by the dowel 6 and bolts 7. The starter ring gear 8 is shown shrunk onto the outer periphery of the flex plate 1. The engine to transmission housing adapter plate 9 is shown abutting the flange of the transmission housing 10.
The torque converter housing is shown supported by a bearing 11 mounted in the engine crankshaft 5 and at its rear by a bearing 12 which is supported in the transmission housing 10.
In the arrangement shown, the torque converter housing 2 has four round internally threaded bushings 13 welded to its front face near its outer periphery. These bushings 13 have stepped diameters 14 which pass through arcuate slots 15 formed in the flex plate 1. Bolts 16 pass through round holes in an annular driving disc 17 and engage with the internal threads in the bushings 13 and tightens the driving disc 17 against the faces of bushings 13. This leaves the flex plate 1 free to revolve relative to the torque converter housing 2 because the stepped diameters 14 are longer axially than the thickness of the flex plate 1. The amount of rotary movement is governed by the size of the stepped diameters 14 contacting the ends of the arcuate slots 15. The torque converter housing 2 is located endwise to the flex plate 1 which is trapped between the driving disc 17 and the shoulders of the stepped diameters 14.
In some torque converter designs which employ threaded studs and nuts instead of bushings and bolts the stepped diameters would be formed on the studs.
A plurality of rectangularly shaped blade springs 18 are arranged in sets and fixedly anchored at one end in slots 19A spaced around the driving hub 3 so that they extend radially from the slots 19A. This anchoring may be accomplished by casting or sintering the inner ends in the slots 19A or LOCTITE™ 620 adhesive may be used. The blade springs 18 can be arranged in various combination of the slots 19A and in sets to suit the power of different engines.
The blade springs 18 connect the driving hub 3 with the torque converter housing 2 by having their free ends received between the rollers 19 near their outer ends. These rollers 19 rotate on pins 20 which are rivetted to the driving disk 17. The pins 20 pass through the arcuate slots 21 in flex plate 1. Engine torque or reverse torque from the wheels of the vehicle will deflect the blade springs 18 either side of their no load positions to an extent governed by the amount of movement allowed before the abutting of the stepped diameters 14 in the arcuate slots 15. This limits deflection of the blade springs 18 to prevent their overstressing.
This movement is detected by position sensors 22 and 23 interfacing with teeth 24 and 25 formed in the peripheries of the flex plate 1 and torque converter housing 2 respectively. Diagrammatic representations of an on board microprocessor 25 and a utilization device 26 are shown.
FIG. 3 also shows how the flex plate 1, driving hub 3, driving disc 17, sets of blade springs 18, pins 20, rollers 19 and the starter ring gear 8 can be subassembled and bolted to the crankshaft 5 before the transmission housing 10 and torque converter housing 2 are brought together with the engine. At this stage, only the holes 17A in the driving disc 17 have to be lined up with the threaded holes in the fasteners 13. The bolts 16 are inserted one at a time through an opening 9A in the adapter plate 9. This is no different from lining up the fasteners 13 with the round holes in a conventional flex plate assembly without the presence of the torque sensor arrangement.
FIG. 4 shows an optional sensor in the form of an electroptical device 27 interfacing with radial slots 28 and 29 formed in the peripheries of the flex plate 1 and the torque converter housing.
FIGS. 5-8 show a torque sensor according to the invention using a two piece flywheel, consisting of a driving member 31 attached with bolts 32 to the crankshaft 33 of an internal combustion engine. A starter ring gear 34 is shown shrunk on to the periphery of the driving member 31. The driven member 35 of the two part flywheel has a boss portion 35A which nestles inside a circular recess 31A in the driving member 1 and retained longitudinally by a series of bolts 36, retaining disc 37, and the hollow sleeves 38. The sleeves 38 are located in counterbores 38A in the front face of the driven member boss 35A and pass through arcuate slots 39 in the driving member 31. A series of rollers 40 rotate on the sleeves 38 and bear on the inside of a recess diameter 41 in the driving member 31.
The driven member 35 is thus rotatably supported on the driving member 31 by the rollers 40 and 44, which eliminates friction and provide large diameter rotational support.
The driving member 31 and the driven member 35 are thus free to rotate relative each other by the amount of circumferential clearance which the sleeves 38 have in the arcuate slots 39. An endwise free play is provided between the rear face 37A of the retaining disc 37 and the bottom face 42A of the circular recess 42 machined in the front face 31B of the driving member 31. An endwise clearance also exists between the rear face 31C of the driving member 31 and the recessed face 35B of the driven member 35 except where they touch at 43. The first endwise clearance allows free relative rotation between the driving member 31 and driven member 35.
A further series of rollers 44 are located on pins 45 pressed into the front face of the driven member 35 (shown in FIG. 6).
Engine torque is transmitted from the crankshaft 33 through the bolts 32 and the dowel 46 to the driving hub 47 and then by sets of blade springs 48 anchored at their inner ends in slots 49 formed in the driving hub 47, their outer free ends passing between and in contact with the rollers 50 centered on pins 51 pressed into the front face of the driven member 35 (see FIG. 7). The blade springs 48 are shown packed in sets of three in each slot 49 in order to increase their deflection compared to using a single blade spring 48 under the same load. In the arrangement shown, torque can be transmitted in both directions.
A dust deflector 57 is bolted to the driving hub 47 by the bolts 32. A friction clutch is shown at 58.
Two position sensors 52 and 53 are diagrammatically shown juxtaposed with the teeth in the starter ring gear 34 and teeth 54 formed on the periphery of the driven member 35 to send electronic signals corresponding to angular deflection of the driven member 31 and driven member 35 to an on board microprocessor 55 and a utilization device 56.
FIG. 9 and 10 refer to a typical three piece coupling driving a transmission with its own disconnect clutches.
The first driving member 61 is bolted to an engine flywheel 62 by bolts 63. The driving member 61 is connected to a second driving member 64 by stepped rivets 65 which also attach the driving hub 66 to the driving member 61. A driven member 67 is positioned and trapped between the driving members 61 and 64 and has internal splines 68 machined in its hub to drive the input shaft 69 of a transmission carried in the housing 70. The inner diameters 71 and 72 ride on the outside diameters 83 and 84 of the hub of driven member 77. Arcuate slots 73 formed in the driven member 67 allow the stepped rivets 65 to pass through and they also limit the rotation between the driven member 67 and the driving members 61 and 64.
The transmission of torque from the flywheel 62 and the driving members 61 and 64 is by rectangular blade springs 74 fixedly anchored at their inner ends in slots 75 formed in the driving hub 66 and passing between and contacting at their outer ends rollers 76 which are free to rotate on pins 77 riveted to the driven member 67. Engine torque or reverse torque from the vehicles wheels will deflect the blade springs 74 either side of their no load position to an extent governed by the movement the stepped rivets 65 have in the arcuate slots 73. This movement is detected by position sensors or an electro-optical sensor 78 interfacing the slots 79 and 80 cut radially in peripheral extensions of the driven disc 67 and driving disc 64 respectively.
FIGS. 11 and 12 depict another way to construct a two-member flywheel which eliminates the friction occurring at the faces 31C, 43, 42A, and 37A in the embodiment shown in FIGS. 5 and 7.
A first or driving member 80 is attached with bolts 82 to an engine crankshaft 84, while an outer, second or driven member 86 is engageable with a pressure plate 81 and clutch disc 83. A clutch cover 85 is also depicted in phantom.
The annular driven member 86 has a circumferentially arrayed series of rollers 88 mounted to its front face 90 by means of the shouldered pins 92 pressed into axial bores 94 in the front face 90. The rollers 88 are rotatably mounted on the pins 92 by means of needle bearings 96, and are axially confined by heads 100 on the pins 92.
The rollers 88 are toroidal in shape having a semicircular in section peripheral surface 102 which run in semicircular grooves 104, formed into radial protrusions 106 projecting radially from the perimeter surface of the hub of driving member 80.
The driven member 86 is thus supported for limited rotation on the outer perimeter surface of the hub of the driving member 80.
The extent of rotation is defined by engagement of pin and slot arrangements each comprised of a pin 108 which is press fit into an axial bore 110 in a radial face 112 of the drive member 80 and a slot 114 through the inner flange 116 of the driven member 86. The pin 108 is normally centered in the slot 114 with a predetermined clearance in either circumferential direction allowing a predetermined limited extent of relative rotation between the driving member 80 and driven member 86 in either direction.
The driving member 80 and driven member 86 are rotatively coupled by a series of blade springs 118 fixed at their inner ends in radial slots 120 of the driving member 80 in the outer perimeter intermediate the lugs 106, a suitable adhesive such as LOCTITE™ 620 is used for this purpose.
The blade springs 118 are received between pairs of rollers 122 revolvable on the heads 124 of pins 126, retained thereon by integral flanges 130. The pins 126 are press fit in axial bores 132 in the face 90 of the driven member 86 directed towards the drive member 80, and project axially over the outer perimeter of the driving member 80 such that the rollers 122 are disposed to receive the outer ends of the blade springs 118 therebetween.
The blade springs 118 are in a relaxed state with the pin 108 centered in the slot 114 and exert a spring force by cantilever bending thereof resisting relative rotation in either direction.
The blade springs 118 can be provided in sets of two as shown, or sets of three as shown in the drawing FIGS. 5 and 6 discussed above to suit the particular applications.
The extent of relative rotation corresponds to the torque level, and this relative rotation is measured by a pair of sensors 133 and 134. Sensor 133 is positioned adjacent a disc 136 having a slotted periphery and sensor 134 is positioned adjacent a starter ring gear 138 shrunk onto the outer diameter of driven member 86. Other arrangements of sensors are possible.
The starter ring gear 138 in being mounted on the driven member 86 results in a cushioning action, as the blade springs 118 are interposed between the driven member 86 and the drive member 80 connected to the engine crankshaft. This reduces shocks imposed on the starter motor to prolong its life.
The sensors 133 and 134 generate electronic signals from which the electronic torque can be generated for use in an on board computer to control air-fuel ratio, shift gears, etc., as described above.
FIG. 13 illustrates a modification of this design in which deep grooved sealed ball bearings 140 are press fit onto headed pins 92A having stems pressed into the opposing face of driven member 86A.
The outer race element 142 of each bearing 140 runs in a groove 144 machined into lugs 106A projecting radially from the outer perimeter of the drive member 80A. Endwise and radial clearances are minimal.
Friction is thus minimized by this arrangement to substantially eliminate hysteresis as the blade spring 118 flex during engine loading of the drive train in either direction.
The mounting of the sets of blade springs in each of the above embodiments minimizes wear, friction and hysteresis, are easily assembled, and enable easy adoption to the requirements of particular engine transmission combinations. Fretting corrosion caused by centrifugal forces and torsional oscillations is likewise avoided.
The large spring deflections resulting in the use of multiple thin springs may eliminate the need for the torsional dampener currently used in the lock-up clutches of automotive transmissions and also those used with manually operated friction clutches. | Four different torque sensing arrangements are described: one for an engine driving a torque converter housing (2) for an automatic transmission, two are for engines with two piece flywheels (31, 35 and 80, 86) and one for a three piece coupler (61, 64, 67), where sets of cantilever blade type springs (18, 48, 74, and 118) are arranged to allow a limited extent of rotation of driving and driven members proportioned to the torque being transmitted from the engine to the transmission and vice versa. The relative movement between the member is detected by electronic sensing devices (22, 23; 52, 53; 78; and 132, 134) generating signals transmitted to an on board microprocessor (25 and 55) or other electronic unit. | 6 |
FIELD OF THE INVENTION
[0001] The present invention is directed to fluorescent ligands capable of strongly binding Zn(II) ions or Cd(II) ions.
BACKGROUND OF THE INVENTION
[0002] The selective and quantitative detection of trace amounts of Zn(II) or Cd(II) is commercially desirable for the diagnosis of metal ion induced diseases and in protecting the environment.
[0003] Zinc is an essential element which is present in the body at approximately 1 micromole/L. The USDA recommended dietary intake of Zn(II) is only 15 mg/day, which indicates how little Zn(II) is required to maintain the required level of this element in a healthy adult. Despite this relatively low concentration, Zn(II) plays an essential role in biology and nutrition. Minor perturbations of normal Zn(II) levels have been associated with retarded sexual maturation, stunted growth, and skin damage. Over 99% of Zn(II) in biological tissues and fluids is present in a chemically combined form, with very little present as free Zn(II). Traditional methods such as atomic absorption effectively measure total Zn(II) but cannot distinguish between the chemically combined and the free forms. The problem of detecting free Zn(II) is compounded because total free Zn(II) is decreased only very slightly (50-100 pmol/10 6 cells) in cases of severe Zn(II) deficiency.
[0004] Zinc is the second most abundant transition metal in the brain. Zinc is essential for brain maturation and function. Approximately ninety percent of cellular zinc is bound to metalloproteins, while the remainder is localized at presynaptic vesicles in the ionic or loosely bound form. Vesicular zinc is thought to play an important role in synaptic neurotransmission. Several devastating cerebral disorders, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis (ALS) are associated with abnormally high vesicular Zn(II) concentration (Cuajungo et al., 1997). Because of its association with major neurological disorders, zinc imaging becomes an increasingly important tool in brain research. In particular, fluorescence microscopy is a very useful technique for monitoring real-time zinc distribution.
[0005] Cadmium, both as the free metal and in its compounds, is highly toxic, and has been designated one of the 100 most hazardous substances under Section 110 of the Superfund Amendments and Reauthorization Act of 1986. Poisoning occurs with by ingestion or by inhalation.
[0006] Chemical pneumonitis or pulmonary edema may result from acute exposure to cadmium fumes, as oxide or chloride aerosols, at a dose of 5 mg/m3 over an eight hour period. Acute ingestion of cadmium concentrations above about 15 ppm produce symptoms of nausea, vomiting, abdominal cramps, and headache. Possible sources of such poisoning have been traced to cadmium-plated cooking utensils, cadmium solders in water coolers, or from acid juices stored in ceramic pots glazed using cadmium-treated compounds.
[0007] Most biological molecules do not fluoresce on their own, so they must be linked with fluorescent molecules, or fluorochromes, in order to create specific fluorescent probes. The feasibility of using fluorescence technology for a particular application is often limited by the availability of an appropriate fluorescent sensor. There are a number of features that are desirable in fluorescent sensors, some of which may or may not be present in any particular sensor.
[0008] First, fluorescent sensors should produce a perceptible change in fluorescence upon binding a desired analyte. Second, fluorescent sensors should selectively bind a particular analyte. Third, to allow concentration change to be monitored, fluorescent sensors should have a Kd near the median concentration of the species under investigation. Fourth, fluorescent sensors, especially when used intracellularly, should produce a signal with a high quantum yield. Fifth, the wavelengths of both the light used to excite the fluorescent molecule (excitation wavelengths) and of the emitted light (emission wavelengths) are often important. If possible, for intracellular use, a fluorescent sensor should have excitation wavelengths exceeding 340 nm to permit use with glass microscope objectives and prevent UV-induced cell damage, and possess emission wavelengths approaching 500 nm to avoid autofluorescence from native substances in the cells and allow use with conventional fluorescence microscopy optical filter sets. Finally, ideal sensors should allow for passive and irreversible loading into cells.
[0009] Since the Zn(II) ion is spectroscopically silent, fluorescence microscopy for Zn(II) requires a sensor that makes it possible to observe this ion. There are several requirements that a fluorescent sensor for zinc needs to meet. First of all, it must produce a strong fluorescent signal upon binding the analyte. Secondly, the sensor needs to exhibit strong zinc binding, ideally having an apparent dissociation constant, Kd, near the median of Zn(II) concentration. The latter requirement is particularly challenging, given that Zn(II) concentration is known to be as low as femtomolar (Hitomi et al., 2001). Strong selectivity is another important factor in Zn(II) detection, because Zn(II) concentration is typically six to seven orders of magnitude lower than the concentration of the more abundant divalent metal ions such as Mg(II) and Ca(II) (Fraustro da Silva et al., 1993). Finally, there are several biological requirements to prevent cell damage from excitation and emission wavelengths, as noted above. In addition to that, the sensor must be soluble in physiological media.
[0010] The detection of Zn(II) or Cd(II) in the environment is also important, and is presently an intractable problem. For example, interest in Zn(II) concentrations in the ocean stems from its dual role as a required nanonutrient and as a potential toxic agent due to its widespread industrial and marine usage. Zinc exists at natural levels in ocean surface water at a total concentration of about 0.1 nM. Dissolved Zn(II) concentrations in seawater have been determined using atomic absorption spectrometry, mass spectrometry and voltammetry. The concentration data are inaccurate because of interference from other cations naturally present in sea water. A rapid, selective an more sensitive test for Zn(II) or Cd(II) is desirable.
[0011] A limited number of fluorescent sensors possess these desirable properties.
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to overcome the aforesaid deficiencies in the prior art.
[0013] It is another object of the present invention to provide fluorescent ligands capable of strongly binding Zn(II) or Cd(II).
[0014] It is still another object of the present invention to provide enhanced zinc or cadmium binding along with fluorescence sensing capabilities.
[0015] It is yet another object of the present invention to provide improved methods of detecting Zn(II) or Cd(II) in the presence of other divalent metals.
[0016] The present invention provides fluorescent ligands which are capable of strongly binding Zn(II) or Cd(II) in the presence of other divalent metal ions. These tripodal ligands, illustrated by the compounds shown in FIGS. 1 to 3 , are structurally related to tris(2-pyridylmethyl)amine, TPA, which is known for strong binding of divalent metal ions (Anderegg et al., 1967).
[0017] A and B can be the same or different, and are
[0018] Wherein L 1 , L 2 , and L 3 can be the same or different, and L 1 , L 2 and L 3 are linker groups selected from the group consisting of substituted or unsubstituted carbon atoms, —O—, —S—, —NR 2 , C 6 -C 24 substituted or unsubstituted aromatic and heteroaromatic groups having from 1-3 heteroatoms (N, S, O) or halogen, carbonyl, sulfonyl, or nitrile substitutions, and L 2 and L 3 are optional groups. L 1 and Y can be part of a ring such as pyridine or other heteroaromatic ring.
[0019] R is a terminal group selected form the group consisting of H, C 1 -C 18 branched or straight-chain alkyl, alkenyl, or alkynyl groups groups, C 6 -C 24 substituted or unsubstituted aromatic and heteroaromatic groups having from 1-3 hetero atoms (N, S, O) or halogen substitutions.
[0020] X is HO or NHR
[0021] Y is a metal chelating atom such as N, O, or S
[0022] E is a hydrogen atom or a substituent of the aromatic ring, such as halogen, carbonyl, sulfonyl, or nitrile.
[0023] As used herein, alkyl, alkenyl and alkynyl carbon chains, if not specified, contain from 1 to 20 carbon atoms, preferably from 1 to 16 carbon atoms, and are straight or branched. Alkenyl carbon chains of from 1 to 20 carbon atoms preferably contain 1 to 8 double bonds; the alkenyl carbon chains of 1 to 16 carbon atoms preferably contain from 1 to 5 double bonds.
[0024] Alkynyl carbon chains of from 1 to 20 carbon atoms preferably contain 1 to 8 triple bonds, and the alkynyl carbon chains of 1 to 16 carbon atoms preferably contain 1 to 5 triple bonds. The alkyl, alkenyl, and alkynyl groups may be optionally substituted, with one or more groups, preferably alkyl group substituents that may be the same or different. As used herein, lower alkyl, lower alkenyl, and lower alkynyl refer to carbon chains having fewer than or equal to about 6 carbon atoms.
[0025] As used herein an alkyl group substituent includes halos, haloalkyl, preferably halo lower alkyl, aryl, hydroxy, alkoxy, aryloxy, alkoxy, alkylthio, arylthio, aralkyloxy, aralkylthio, carboxy, alkoxycarbonyl, oxo, and cycloalkyl.
[0026] For the present invention, “cyclic” refers to cyclic groups preferably containing from 3 to 19 carbon atoms, preferably 3 to 10 members, more preferably 5 to 7 members. Cyclic groups include hetero atoms, and may include bridged rings, fused rings, either heterocyclic, cyclic, or aryl rings.
[0027] The term “aryl” herein refers to aromatic cyclic compounds having up to 10 atoms, including carbon atoms, oxygen atoms, sulfur atoms, selenium atoms, etc. Aryl groups include, but are not limited to, groups such as phenyl, substituted phenyl, naphthyl, substituted naphthyl, in which the substituent is preferably lower alkyl, halogen, or lower alkyl. “Aryl” may also refer to fused rings systems having aromatic unsaturation. The fused ring systems can contain up to about 7 rings.
[0028] An “aryl group substituent” as used herein includes alkyl, cycloalkyl, cycloaryl, aryl, heteroaryl, optionally substituted with 1 or more, preferably 1 to 3, substituents selected from halo, haloalkyl, and alkyl, arylalkyl, heteroarylalkyl, alkenyl containing 1 to 2 double bonds, alkynyl containing 1 to 2 triple bonds, halo, hydroxy, polyhaloalkyl, preferably trifluoromethyl, formyl, alkylcarbonyl, arylcarbonyl, optionally substituted with 1 or more, preferably 1 to 3, substituents selected from halo, haloalkyl, alkyl, heteroarylcarbonyl, carboxyl, alkoxycarbonyl, aryloxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, arylalkylaminocarbonyl, alkoxy, aryloxy, perfluoroalkoxy, alkenyloxy, alkynyloxy, arylalkoxy, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, arylaminoalkyl, amino, alkylamino, dialkylamino, arylamino, alkylarylamino, alkylcarbonylamino, arylcarbonylamino, amido, nitro, mercapto, alkylthio, arylthio, perfluoroalkylthio, thiocyano, isothiocyano, alkylsufinyl, alkylsulfonyl, arylsulfinyl, arylsulfonyl, aminosulfonyl, alkylaminosulfinyl, dialkylaminosulfonyl, and arylaminosulfonyl.
[0029] The term “arylalkyl” as used herein refers to an alkyl group which is substituted with one or more aryl groups. Examples of arylalkyl groups include benzyl, 9-fluorenylmethyl, naphthylmethyl, diphenylmethyl, and triphenylmethyl.
[0030] The term “heteroaryl” for purposes of the present application refers to a monocyclic or multicyclic ring system, preferably about 5 to about 15 members, in which at least one atom, preferably 1 to 3 atoms, is a heteroatom, that is, an element other than carbon, including nitrogen, oxygen, or sulfur atoms. The heteroaryl may be optionally substituted with one or more, preferably 1 to 3, aryl group substituents. Exemplary heteroaryl groups include, for example, furanyl, thienyl, pyridyl, pyrrolyl, N-methylpyrrolyl, quinolyinyl and isoquinolinyl.
[0031] The term “heterocyclic” refers to a monocyclic or multicyclic ring system, preferably of 3 to 10 members, more preferably 4 to 7 members, where one or more, preferably 1 to 3, of the atoms in the ring system is a heteroatom, i.e., an atom that is other than carbon, such as nitrogen, oxygen, or sulfur. The heterocycle may be optionally substituted with one or more, preferably 1 to 3, aryl group substituents. Preferred substituents of the heterocyclic group include hydroxy, alkoxy, halo lower alkyl. The term heterocyclic may include heteroaryl. Exemplary heterocyclics include, for example, pyrrolidinyl, piperidinyl, alkylpiperidinyl, morpholinyl, oxadiazolyl, or triazolyl.
[0032] The nomenclature alkyl, alkoxy, carbonyl, etc, is used as is generally understood by those of skilled this art. As used herein, aryl refers to saturated carbon chains that contain one or more carbon atoms; the chains may be straight or branched or include cyclic portions or may be cyclic.
[0033] The term “halogen” or “halide” includes F, Cl, Br, and I. This can include pseudohalides, which are anions that behave substantially similarly to halides. These compounds can be used in the same manner and treated in the same manner as halides. Pseudohalides include, but are not limited to, cyanide, cyanate, thiocyanate, selenocyanate, trifluoromethyl, and azide.
[0034] The term “sulfinyl” refers to —S(O)—. “sulfonyl” refers to —S(O) 2 —.
[0035] “Aminocarbonyl” refers to —C(O)NH 2 .
[0036] “Alkylene” refers to a straight, branched, or cyclic, preferably straight or branched, bivalent aliphatic hydrocarbon group, preferably having from 1 to about 20 carbon atoms. The alkylene group is optionally substituted with one or more alkyl group substituents. There may be optionally inserted along the alkylene group one or more oxygen, sulfur, or substituted or unsubstituted nitrogen atoms, wherein the nitrogen substituent is alkyl. Exemplary alkylene groups include methylene, ethylene, propylene, cyclohexylene, methylenedioxy, and ethylenedioxy. The term “lower alkylene” refers to alkylene groups having from 1 to 6 carbon atoms. Preferred alkylene groups are lower alkylene, with alkylene of 1 to 3 atoms being particularly preferred.
[0037] The term “arylene” as used herein refers to a monocyclic or polycyclic bivalent aromatic group preferably having from 1 to 20 carbon atoms and at least one aromatic ring. The arylene group is optionally substituted with one or more alkyl group substituents. There may be optionally inserted around the arylene group one or more oxygen, sulfur, or substituted or unsubstituted nitrogen atoms, where the nitrogen substituent is alkyl.
[0038] “Heteroarylene” refers to a bivalent monocyclic or multicyclic ring system, preferably of about 5 to about 15 members, wherein one or more of the atoms in the ring system is a heteroatom. The heteroarylene may be optionally substituted with one or more aryl group substituents. As used herein, “alkylidene” refers to a bivalent group, such as ═CR′R″, which is attached to one atom of another group, forming a double bond. “Arylalkylidene” refers to an alkylidene group in which either R′ or R″ is an aryl group.
[0039] As used herein, when any particular group, such as phenyl or pyridyl, is specified, this means that the group is substituted or unsubstituted. Preferred substituents, where not specified, are halo, halo lower alkyl, and lower alkyl.
[0040] The novelty of the design of the compounds of the present invention is in modifying the scaffold structure of TPA with the elements of 8-hydroxyquinoline (8-HQ), as illustrated in FIG. 4 . This modification made it possible to further enhance zinc or cadmium binding in addition to providing fluorescence sensing capabilities. In order to improve spectroscopic properties, the 8-HQ chromophore was derivatized with dimethyl sulfonamide groups. This derivatization had been reported to enhance extinction coefficient and fluorescence yield (Pearce et al., 2001).
[0041] Enhancement of fluorescence was observed upon zinc or cadmium chelation. Moderate enhancement of 4-fold was observed in the case of TRS. TRS2 and TRSS2, on the other hand, exhibited stronger fluorescent enhancement, 10-fold and 25-fold, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] FIG. 1 is the general formula for tripodal ligands of the present invention.
[0043] FIG. 2 illustrates three tripodal ligands of the present invention.
[0044] FIG. 3 illustrates another tripodal zinc sensor of the present invention.
[0045] FIG. 4 illustrates design of the sensors from 8-hydroxyquinaldine.
[0046] FIG. 5 illustrates design of the sensors from 8-hydroxyquinaldine.
[0047] FIG. 6 illustrates synthesis of two of the compounds of the present invention.
[0048] FIG. 7 shows the X-ray structure of Zn(TRS 1).
[0049] FIG. 8 shows the UV-visible absorbance of TRS 2 as function of zinc (II) concentration.
[0050] FIG. 9 shows the UV-visible absorbance of TRS 1 as function of zinc (II) concentration.
[0051] FIG. 10 shows the fluorescence response of TRS 2 to buffered Zn(II) solutions.
[0052] FIG. 11 shows the fluorescence response of TRS 2 to buffered Zn(II) solutions.
[0053] FIG. 12 illustrates TRS1 sensitivity to Zn(II).
[0054] FIG. 13 illustrates TRS2 sensitivity to Zn(II).
[0055] FIG. 14 illustrates synthesis of two of the compounds of the present invention.
[0056] FIG. 15 illustrates how the compounds of the present invention improve the fluorescence quantum yield of the 8-hydroxyquinoline derivatives.
[0057] FIG. 16 shows UV-visible absorbance of TRS as a function of Zn(II) concentration.
[0058] FIG. 17 shows fluorescence enhancement of TRS as a function of Zn(II) concentration.
[0059] FIG. 18 shows fluorescence enhancement of TRS as a function of Zn(II) concentration.
[0060] FIG. 19 shows fluorescence response of TRS to buffered Zn(II) solutions.
[0061] FIG. 20 shows synthesis of TRSS 2.
DETAILED DESCRIPTION OF THE INVENTION
[0062] The most important property exhibited by the tripodal ligands of the present invention is strong preferential binding of Zn(II). This strength of binding is similar to the one observed in zinc enzymes. The binding constant of TRS was found to be log K1=13.77, which falls within the median physiological zinc concentration. TRS would be able to sense Zn(II) at femtomolar concentrations. TRS2 and TRSS2 showed subpicomolar sensitivity towards Zn(II) with binding constants log K1=12.53 and log K1=13.29, respectively.
[0063] Selectivity for zinc over biologically abundant metals such as calcium, magnesium, sodium and potassium was observed.
[0064] The fluorescent zinc or cadmium sensors of the present invention are highly sensitive towards the analyte. Their sensitivity (femtomolar to sub-picomolar) lies within the concentration range of physiologically occurring Zn(II) or Cd(II). Therefore, these sensors can be used as quantitative zinc probes in fluorescence microscopy. These tripodal ligands can offer a clear advantage for imaging cellular zinc or cadmium, as well as trace amounts of these metals in environmental samples.
[0065] The fluorescence of ligands of the present invention may be detected by essentially any suitable fluorescence detection device. Such devices are typically comprised of a light source for excitation of the fluorophore and a sensor for detecting emitted light. In addition, fluorescence detection devices typically contain a means for controlling the wavelength of the excitation light and a means for controlling the wavelength of light detected by the sensor. These means for controlling wavelengths are referred to generally as filters, and can include diffraction gratings, dichroic mirrors, or filters. Examples of suitable devices include fluorimeters, spectrofluorimeters, and fluorescence microscopes. Many such devices are commercially available. In certain embodiments, the device may be coupled to a signal amplifier and a computer for data processing.
[0066] In general, assays using the tripodal ligands of the present invention involve contacting a sample with such a ligand and measuring fluorescence emitted. The presence of Zn(II) or Cd(II) may alter the fluorescence in many different ways. Essentially any change in fluorescence caused by the Zn(II) or Cd(II) can be used to determine the presence of the Zn(II) or Cd(II) and, optionally the concentration of the Zn(II) or Cd(II) in the sample.
[0067] The change in fluorescence may take one or more of several forms, including a change in excitation or emission spectra, or a change in the intensity of the fluorescence and/or quantum yield. These changes may be in the positive or negative direction, and may be of a range of magnitudes.
[0068] The excitation spectrum is the wavelengths of light capable of causing the ligand to fluoresce. To determine the excitation spectrum for a ligand in a sample, different wavelengths of light are tested sequentially for their abilities to excite the sample. For each excitation wavelength tested, emitted light is measured. Emitted light may be measured across an interval of wavelengths (for example from 450 to 700 nm), or emitted light may be measured as total of all light with wavelengths above a certain threshold (for example, wavelengths greater than 500 nm). A profile is produced of the emitted light produced in response to each tested excitation wavelength, and the point of maximum emitted light can be referred to as the maximum excitation wavelength. A change in this maximum excitation wavelength, or a change in the shape of the profile caused by metal in a sample may be used as the basis for determining the presence, and optionally, the concentration, of Zn(II) or Cd(II) in the sample. Alternatively, the emission spectrum may be determined by examining the spectra of emitted light in response to excitation with a particular wavelength (or interval of wavelengths). A profile of emissions at different wavelengths is created, and the wavelength at which emission is maximal is called the maximum emission wavelength. Changes in the maximum emission wavelength or the shape of the profile that are caused by the presence of Zn(II) or Cd(II) in a sample may be used to determine the presence or concentration of the metal ion in the sample. Changes in excitation or emission spectra may be measured as ratios of two wavelengths. A range of changes is possible, from about a few nms to 5, 20, 25, 50, 75, 100 or more nm.
[0000] In vitro Assays
[0069] In one embodiment of the present invention, the presence of Zn(II) or Cd(II) in a sample is detected by contacting the sample with a tripodal ligand according to the present invention. The fluorescence of the solution is then determined using one of the above-described devices, preferably a spectofluorimeter. Optionally, the fluorescence of the solution may be compared to a set of standard solutions containing known quantities of Zn(II) or Cd(II). Comparison to standards may be used to calculate the concentration of Zn(II) or Cd(II).
[0070] Although the tripodal ligands are particularly useful for detecting small quantities of Zn(II) or Cd(II) in physiological specimens such as brain tissue for diagnosing neurological diseases such as Alzheimer's and Parkinson's diseases, they can also be used to detect small quantities of Zn(II) or Cd(II) in environmental samples such as water samples, soil leachates, or sediment samples.
[0000] In vivo Assays
[0071] Biological samples may include bacterial or eukaryotic cells, tissue samples, lysates, or fluids from a living organism. In certain embodiments, the specimens are brain tissues. It is also anticipated that detection of Zn(II) or Cd(II) in a cell may include detection of the metal in subcellular or extracellular compartments or organelles. Such subcellular organelles and compartments include: Golgi networks and vesicles, pre-synaptic vesicles, lysosomes, vacuoles, nuclei, chromatin, mitochondria, chloroplasts, endoplasmic reticulum, coated vesicles (including clathrin coated vesicles), caveolae, peroplasmic space, and extracellular matrices.
[0000] Assays Using the Subject Compounds
[0072] The solution or biological sample is contacted with a tripodal ligand according to the present invention, and fluorescence of the ligand is excited by light with wavelengths ranging from 340 nm to about 380 nm. Light emitted by the ligand is detected by detecting light of wavelengths greater than from about 480 to about 600 nm.
[0000] Synthesis of the Tripodal Ligands
[0073] FIGS. 6 and 14 illustrate the structural design of the tripodal ligands of the present invention. The scaffold structure of TPA is modified with the elements of 8-hydroxyquinoline. It was discovered that the most active compound was the compound TRS, shown in FIG. 3 , the compound with two sulfonamide groups attached to the 8-hydroxyquinoline.
[0074] As shown in FIG. 7 , zinc makes four coordinations with the two 8-hydroxyquinoline moieties, and one coordination with the pyridyl nitrogen.
[0075] FIGS. 8 and 9 show the UV-visible absorbance of TRS 1 and TRS 2, respectively, 30 micromolar, as a function of Zn(II) concentration. The spectra were acquired in 1% DMSO aqueous solution (0.1 M KNO3, 50 mM HEPES, pH 7.0). The inset in both of these figures is a molar ratio plot of Zn(II).
[0076] FIGS. 10 and 11 show the fluorescence response of 30 micromolar TRS 1 and TRS 2, respectively, to buffered Zn(II) solutions. The spectra were acquired in 1% DMSO aqueous solution (0.1 M KNO 3 , 50 mM HEPES, pH 7.2 at 25° C.) with excitation at 365 nm. The zinc ion concentration was buffered by 10 mM EDTA.
[0077] FIGS. 12 and 13 show sensitivity of TRS 1 and TRS 2, respectively, for total Zn(II). In FIG. 12 , the spectra shown are for total Zn(II) at 0, 2, 4, 6, 10, 20, 30, 40, 50, 60, 70, 80, 90 mM with corresponding free Zn(II) at 10 −25.68 , 10 −15.38 , 10 −15.2 , 10 −14.98 , 10 −14.68 , 10 −14.5 , 10 −14.38 , 10 −14.2 , 10 −14.132 , 10 −14.07 , and 10 −14.02 M, respectively. In FIG. 13 , the spectra shown are for total Zn(II) at 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 M with corresponding free Zn(II) at 10 −13.98 , 10 −13.67 , 10 −13.36 , 10 −13.26 , 10 −13.17 , 10 −13.1 , 10 −13.04 , 10 −12.98 , 10 −12.93 , 10 −12.58 , 10 −12.35, and 10 −12.16 , 10 −11.98 , 10 −11.8 , 10 −11.62 , 10 −11.38 , 10 −11.03 M, respectively.
[0078] FIG. 16 shows UV-visible absorbance of 30 micromolar TRS as a function of Zn(II) concentration. The spectra were acquired in 1% DMSO aqueous solution (0.1 M KNO3, 50 mM HEPES, pH 7.0). The inset is a molar ratio plot.
[0079] FIG. 17 shows UV-visible absorbance of 30 micromolar TR as a function of Zn(II) concentration. The spectra were acquired in 20% DMSO aqueous solution (0.1 M KNO3, 50 mM HEPES, pH 7.0). The inset is a molar ratio plot.
[0080] FIG. 18 shows enhancement of 30 micromolar TRS fluorescence as a function of Zn(II) concentration. The spectra were acquired in 1% DMSO aqueous solution (0.1 M KNO3, 50 mM HEPES, pH 7.0). The inset is a molar ratio plot.
[0081] FIG. 19 shows enhancement of 30 micromolar TR fluorescence as a function of Zn(II) concentration. The spectra were acquired in 50% DMSO aqueous solution (0.1 M KNO3, 50 mM HEPES, pH 7.0). The inset is a molar ratio plot.
[0082] While use of the tripodal ligands for detecting Zn(II) or Cd(II) detection has been illustrated using florescence microscopy, other type of fluorescence detection are possible using these ligands. For example, Zn(II) or Cd(II) can be detected using the ligands of the present invention in conjunction with other fluorescent techniques such as spectroscopy or time-resolved fluorescence spectroscopy/microscopy.
[0083] It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means and materials for carrying out disclosed functions may take a variety of alternative forms without departing from the invention. Thus, the expressions “means to . . . ” and “means for . . . ” as may be found the specification above, and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical, or electrical element or structures which may now or in the future exist for carrying out the recited function, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above, and it is intended that such expressions be given their broadest interpretation. | Highly sensitive fluorescent zinc or cadmium sensors are derived from 8-hydroxyquinaldine, a well-established fluorescent zinc probe, as a building block. High binding efficiency was achieved by incorporating two 8-hydroxyquninaldine moieties into a single ligand. Incorporation of sulfonamide groups further improved binding efficiency. The compounds make it possible to monitor zinc ion or cadmium ion concentration in the picomolar or femtomolar range. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a divisional of our cognate patent application Ser. No. 06/792,210, filed on Oct. 28, 1985 and entitled: METHOD AND APPARATUS FOR PRODUCTION OF INVOLUTE GEAR TOOTH FLANKS.
BACKGROUND OF THE INVENTION
The present invention broadly relates to a method and apparatus for fabricating involute gear tooth flanks.
Generally speaking, the invention relates to a method for fabricating involute gear tooth flanks without or with geometric corrections by means of at least one machining tool and in which method machining, feed and traversing motions between the machining tool and a workpiece or gear blank are performed.
The invention is also concerned with a machine tool or machining apparatus for performing the method and comprising a machine frame with a generating carriage translatably seated on this machine frame. The machine tool or machining apparatus further comprises a workpiece or gear blank carrier or support and clamping means for holding a workpiece or gear blank and a multiple-carriage or carriage-and-slide arrangement for performing the machining, traversing and feed motions. Drive means as well as control means for carrying out, i.e. controlling and powering, these movements are also provided.
In a known method of fabricating involute gear tooth flanks, conical or dished grinding wheels are used which each respectively process a right and a left gear tooth flank. For this purpose, the two grinding wheels are fixed at an angle in relation to each other such that working or machining planes of the grinding wheels define the surfaces of a hypothetical generating rack on which the gear to be ground is generated or rolled. The inclination of the grinding wheels to a normal to the generating roll plane or pitch plane is generally the same as the pressure angle of the gear teeth. The relative motion between the machining tool or grinding wheel and the workpiece or gear blank for generating the involute form, the so-called generating roll motion, is derived from the pitch circle. FIG. 6 hereof shows the generating process of a gear wheel on a hypothetical rack in transverse section and in a number of phases. The points A, P, C, T and E' delimit segments of the line of action which correspond to regions of the tooth flank. The addendum flank or flank region is formed on the tooth flank during the grinding process when the section AC of the line of action is traversed. When the section CT of the line of action is traversed, then an initial or outer dedendum flank or flank region of the tooth flank involute is correspondingly formed.
The point T on the line of action is reached when the corner point K of the basic tooth rack profile lies on the line of centers OC connecting the workpiece or gear blank center 0 with the pitch point C on the line of action. The section TE of the line of action corresponds to two segments on the tooth flank which are formed simultaneously (cf. FIG. 11): a further or inner dedendum flank portion of the tooth flank involute and a trochoidal or undercut dedendum or root fillet radius. The point E is the lowest or innermost point of the involute and at the same time the initial point of the dedendum or root fillet trochoid or undercut. The curves or semicircles shown in dotted lines in FIG. 11 indicate which points of the inner dedendum flank portion of the tooth involute and of the dedendum fillet or undercut are simultaneously generated.
FIG. 16 shows the working or machining points Pi', Pi" on a dished or flat grinding wheel or disk which is in contact with the tooth flank of the workpiece or gear blank. During the grinding process, these working or machining points wander, depending upon the generating roll position i, along the machining or grinding surface of the disk and the edges of the grinding wheel and each such working or machining point lies on a generatrix of the tooth flank surface.
During the generating process, a working or machining point of a conical or beveled grinding wheel will wander along a meridian over a working or machining width of the grinding disk corresponding to the entire tooth flank. Machines or apparatus for such a process are, for example, described in the Swiss Pat. No. 592,604 granted Oct. 31, 1972, and the German Pat. No. 2,050,946, granted May 13, 1976. It is a disadvantage of this process that topological or geometric flank corrections can only be carried out to a relatively limited extent since due to the forces which arise between the workpiece or gear blank and the machining tool and other system conditions relative to the size of the gear tooth in general, a larger area of the grinding wheel or disk is involved in the machining process producing the involute form. The working or machining regions especially can only be very coarsely localized and can be influenced only by altering system features which are very difficult or impossible to carry out, such as grinding wheel size or shape.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind, it is a primary object of the present invention to provide a new and improved apparatus for fabricating involute gear tooth flanks which do not exhibit the aforementioned drawbacks and shortcomings found in the prior art.
Another and more specific object of the present invention is to assure that the working or machining regions of the grinding wheels can, on the one hand, be kept small and that working or machining points of grinding wheel surfaces can, on the other hand, be predetermined in location for achieving more accurate tooth flank forms and more accurate and specific topographical or geometric corrections.
A further object of the invention is to provide machine tools or machining apparatus for performing the inventive method.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the method of the present invention for fabricating involute gear tooth flanks is manifested by the features that working or machining contact between the workpiece or gear blank and the machining tool or grinding wheel is confined to a selectable working or machining point or to within the immediate vicinity thereof. The feed motion is performed such that the working or machining point is guided essentially along a selectably predeterminate working or machining line which lies at least approximately on the tooth flank surface for generating a generatrix envelope.
The apparatus of the present invention for fabricating involute gear tooth flanks is manifested by the features that it comprises guiding means and control means for controlling and guiding a selectable work or machining point on the machining tool along a selectably predeterminate working or machining line essentially extending along the tooth flank surface. For this purpose, the guiding means are connected with position determination means which transmit positioning signals to the control means for controlling the driving means.
An advantageous step of the inventive method consists in that the variably selectable working or machining point of the tool or grinding wheel, or at least a region in the immediate vicinity of this machining point, is confined during the machining operation by a supplementary feed motion of the tool to a working or machining region of the machining tool which is prescribable or predeterminate independently of the generating process.
A further advantageous step of the method consists in that the selectable working or machining point of the machining tool, or at least a region in the immediately vicinity of the machining point, is confined during the machining operation conjointly by a supplementary feed motion of the machining tool and a supplementary feed motion of the workpiece or gear blank toward the machining tool to a working or machining region of the machining tool which is prescribable or predeterminate independently of the generating process.
The supplementary feed motion of the machining tool can be performed along a symmetry plane or surface of tooth-space.
The supplementary feed motion of the workpiece or gear blank towards the machining tool can also be performed as a translatory motion, a rotary motion or a pure generating feed motion.
According to a further advantageous method step, the selectable working or machining point of the machining tool, or at least of a region in the immediate vicinity of the machining point, is continuously and prescribably or predeterminately displaced within the working or machining region during the machining operation by means of a work or machining point feed motion conforming to the wear of the machining tool.
The supplementary feed motions can be coupled with conventional or basic feed motions performed along the working or machining line for generating involute gear tooth flanks according to their generatrix envelopes.
For this purpose, the prescribable or predeterminate, i.e. selectably predeterminate, working or machining line may comprise segments which at least approximate generatrices of the tooth flank surface.
The prescribable or predeterminate, i.e. selectably predeterminate, working or machining line can also be composed of segments in which a first branch at least approximates a generatrix and a second branch at least approximates a profile line.
Furthermore, it is also possible to couple the supplementary feed motions with the conventional or basic feed motions along the working or machining line for producing involute gear tooth flanks according to their flank generatrix or tooth trace envelopes.
The prescribable or predeterminate working or machining line can be composed of segments which at least approximate tooth traces or flank lines of the tooth flank surfaces.
Alternatively, the prescribable or predeterminate working line can be composed of sections or segments in which a first branch is at least one tooth trace or flank line and a second branch or segment at least approximates a profile line.
The supplementary feed motion can be performed tangentially to the tooth flank or tangentially to a tooth flank meridian.
A further possibility is that the control of the working or machining point relative to the machining tool or grinding wheel surface can be performed in dependence of wear measurements on this machining tool surface.
The control of the motion of the work or machining point for achieving a better exploitation of the machining tool can also be performed in dependence of wear measurements and empirical values.
Furthermore, it is advantageous if the motion of the work or machining point is continuously or discontinuously superimposed on the supplementary feed motion.
In this inventive method, traversing motion for generating uncorrected tooth flanks can be performed in at least one stage, i.e. in one or more stages.
In the generation of topographically or geometrically corrected tooth flanks, the traversing motion on the selectably prescribable working or machining line can be performed in at least one stage. The traversing motions of possible further stages corresponding to the correction values for each correction point are performed continuously.
The traversing motions can be performed either by the machining tool or by the workpiece or gear blank and, here again, can be purely translatory, purely rotary or a combination of both types of motion.
All motions can be controlled by prescribable or predeterminate data or functions of data.
However, it is also possible for all motions, except generating feed motions known per se, to be controlled by prescribable or predeterminate data or functions of data.
The supplementary feed motion can also be controlled such that, given variable and continuously measured values for the generating path of the workpiece or gear blank center and for the longitudinal feed of the machining tool or grinding wheel relative to a reference point on the hypothetical reference or basic generating rack tooth flank tangent surface, the distance of the common working or machining point of the machining tool and of the workpiece or gear blank from a reference point, for example from the reference point on the reference or basic generating rack tooth flank, at least approximately satisfies the equation:
ys=h·tan γ+(w·sin αt)/cos γ(1)
The means of guidance of the apparatus for carrying out the method can comprise at least one slide or carriage providing at least one supplementary degree of adjustment freedom for the motion of the machining tool or tools.
One slide or carriage can also be provided for each machining tool as a guide means so that the machining tool or tools and their associated working or machining point are, in addition to all other motions, also displaceable tangentially to the tooth flank surface.
At least one slide or carriage can be provided as a guide means for a feed motion of the machining tool radial to the workpiece or gear blank. It is also possible to provide a slide or carriage for a feed motion tangential to the gear tooth flank.
Furthermore, the control means for controlling the generating feed motion can be mechanical means of control known per se, while the control means for controlling all other motions, or for that matter all of the motions, can be electronic circuitry means.
It is especially advantageous for the electronic circuitry means to comprise a master computer or control processor connected to:
a master control interface for signal input and output;
a grinding wheel control means for regulatably controlling at least one grinding wheel drive means;
a carriage control means for conjointly controlling appropriate drive means for standard pressure angle, tooth helix angle and motion of the intermediate slide or carriage to adjust or regulate the pressure angle adjustment;
an adjustment means for adjusting the tooth helix angle and at least one intermediate slide or carriage;
supplementary feed control means for controlling at least one drive means for at least one supplementary feed motion of each machining tool, for example either by means of a slide or carriage or as a resultant of a number of conjoint feed motions;
a traversing control means for controlling at least one drive means for normal traversing motions, topographical or geometrical correction traversing motions or both; and
a measuring control means for operating a grinding wheel measuring or monitoring means and also connected to the control means for controlling the other motions.
The machining tool can comprise a dished grinding wheel or disk of a type known per se, a conical or beveled grinding wheel or disk of a type known per se or a dished grinding wheel or disk whose working or machining surface is a frustum of a cone with an included or cone angle slightly less than 180°.
An important advantage of the inventive method consists in that, even in comparison to the topographical or geometric correction relationships, larger and therefore more stable grinding wheels or disks or also other types of machining tools, for instance milling cutters, can be employed. This also entails other economical and technological advantages. In particular, in comparison to known methods, only a relatively small zone of the grinding wheel or disk need be sensed for wear monitoring and measurement. The controllable displacement of the active grinding zone entails, among other things, the additional advantage of an improved self-sharpening effect and therefore a considerably better exploitation of the grinding wheel or disk. The working or fillet radius can therefore also be controllably and considerably improved and machined.
The adjustability of the grinding wheel or disk is also improved due to the improved controllability of the active machining zone or region of the grinding wheel or disk as a result of its working or machining region being reduced in size and of the controllable displacement of the working or machining point. The topographical or geometric corrections can also be carried out considerably more accurately and with better distribution by means of such a controllable and practically definable working or machining point. The end or final values as well as control values for geometric correction are more easily mastered and better realisable, or are only thus possible. Difficult running properties of gears can be mastered and corrected considerably more specifically and therefore better than hitherto. The accuracy of fabrication is better and therefore better suited to specific conditions. There thus results a considerable improvement in the quality of the finished gears.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein throughout the various figures of the drawings there have been generally used the same reference characters to denote the same or analogous components and wherein:
FIG. 1 shows the geometric relationships between a helical spur gear and the associated reference or basic generating rack tooth flank in a first generating position;
FIG. 2 shows the geometric relationship between a helical spur gear and the associated reference or basic generating rack tooth flank in a second generating position;
FIG. 3 shows the projection of the reference or basic generating rack tooth flank on the transverse section plane in two generating positions, including the geometrical relationships of significant variables;
FIG. 4 shows the projection of the reference or basic generating rack tooth flank on the transverse section plane and, superimposed thereupon, a rotation of the reference or basic generating rack tooth flank into this transverse section plane, including the geometrical relationships of significant variables;
FIG. 5 shows a projection of the reference or basic generating rack tooth flank according to FIG. 4, including significant geometrical variables and relationships for two generating positions;
FIG. 6 shows the gear generating relationships between the gear tooth flank and the machining tool surface in various generating positions according to the state of the art;
FIG. 7 shows the gear generating relationships between the gear tooth flank and the machining tool surface in various generating position according to the invention;
FIG. 8 shows a variation of working or machining lines for processing of tooth flanks extending essentially along generatrices;
FIG. 9 shows a further variation of working or machining lines extending essentially along helices or spiral lines;
FIGS. 10a, 10b and 10c show various grinding wheels suitable for the inventive method;
FIG. 11 shows simultaneously generated points of the second or inner dedendum portion of the tooth flank involute and the root fillet radius or undercut;
FIG. 12 shows a depiction of the important motion axes of the inventive method when using a work or machining line comprising generatrix segments wherein, for the sake of representational clarity, the relationships for fabrication of straight toothing are shown;
FIG. 13 shows a schematic diagram of a control device or means for an exemplary embodiment of a machine tool or gear generating machine;
FIG. 14 shows a schematic depiction of an exemplary embodiment of a machining tool or gear generating machine employing a working or machining line having generatrix linear segments;
FIGS. 15a and 15b show the schematic depiction of a further exemplary embodiment of a machining tool or gear generating machine employing helical or spiral working or machining lines; and
FIG. 16 shows the two working or machining points of prior art methods when employing a generatrix working or machining line and using a dished grinding wheel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that to simplify the showing thereof only enough of the apparatus for fabricating involute gear tooth flanks has been illustrated therein as is needed to enable one skilled in the art to readily understand the underlying principles and concepts of this invention. In one exemplary embodiment of the inventive fabricating method for involute gear tooth flanks, the workpiece or gear blank is in general horizontally or vertically clamped on a workpiece or gear table or rotary table equipped for performing the requisite generating feed motions. The tooth flank is subjected to a generating roll motion in relation to a machining surface of at least one grinding wheel or disk and which machining surface corresponds to the tooth flank of the reference or basic generating rack profile. The grinding wheel or disk simultaneously performs a rotary slide or carriage motion and a feed motion essentially along a generatrix of the tooth flank as a working or machining line. A traversing motion in the direction towards the tooth flank (i.e. a feed motion) determines the depth of cut. The workpiece or gear blank performs the generating feed motion (generatrix envelope).
In addition to these feed motions, a supplementary feed motion is performed which is tangential to the tooth flank, preferably tangential as seen in transverse section (cf. FIG. 7). This supplementary feed motion is a relative motion between the workpiece or gear blank and the machining tool or grinding wheel or wheels. The grinding wheel or disk is thus entrained together with its momentary or active and variably selectable working or machining point in the direction of the gear tooth flank and the prescribable or predeterminate and selectable working or machining point moves on the tooth flank along a generatrix as a selectable or selectably predeterminate working or machining line, also known as the operative line. The working or machining point on the grinding wheel or disk remains (except for its rotation) at one point and does not wander, as is the case with prior art methods, over the entire working or machining width of the grinding wheel or disk in correspondence to the generating motions of the tooth flank on it. The working or machining point on the grinding wheel or disk is thus prescribable or predeterminate and selectable.
Furthermore, it is held in a prescribable working or machining region of the grinding zone independently of the grinding process. Consequently, this working or machining region can also be of smaller dimension or extent than in prior art methods. This is especially advantageous with coated tools, since the coating can then be applied to a smaller area. In particular, the supplementary feed motion can be controlled or governed in accordance with the formula or equation (FIG. 5):
ys=h·tan γ+(w·sin αt) /cos γ(1)
wherein:
ys=distance of the working or machining point S from a contact point M on the gear tooth flank;
w=generating path length; continuously
h=grinding stroke length; monitored
αt=pressure angle in transverse section; and
γ=angle between generatrix and pitch line of the generated tooth flank.
Turning now specifically to FIG. 5 of the drawings, a helical spur gear is seen in mesh with a hypothetical reference or basic generating rack. In the initial position of the generating roll motion and the grinding motion, the contact line between the reference or basic generating rack tooth flank and the gear tooth flank is the line Bo and a working area or machining region meridian is the dotted line To. Consequently, the working or machining point is the intersection point S of these two lines. As is depicted in FIGS. 3 and 5, the distance g between the contact line Bo and a contact line B corresponds to the generating path w and is related thereto according to the formula:
q=w·sinαt (2)
Consequently, during a generating path w and a grinding stroke h, the working or machining point wanders towards S. The distance ys of point S from an initial position M (chosen as reference point and advantageously as median point of the developed flank plane, i.e. of the generating rack tooth flank) is calculated according to formulas given above. This supplementary feed motion, e.g. of the grinding wheel or disk, can be superimposed on a work or machining point motion which discontinuously or continuously incrementally prescribably displaces the work or machining point relative to its working area or machining region. Therefore, the working or machining point, for example during a given number of grinding wheel revolutions, can be held at a specific distance from the inside or the outside edge of the working or machining surface of the grinding wheel and subsequently brought into an adjacent position for the following revolution group (displacement cycle) until the whole or a prescribable or predeterminate portion of the working area or machining region of the machining tool, i.e. of the grinding wheel, has been swept. Subsequently, a new displacement cycle of the grinding wheel is initiated. With this continuous prescribable or predeterminate displacement of the work or machining point, a spiral track or path is swept or traversed in the working area or machining region during each displacement cycle. Nevertheless, it is not absolutely necessary that this work or machining point displacement be performed in a cyclical manner. It is also possible to jump from one circular track or path to another circular track or path.
The control of working or machining point displacement is performed according to prescribable or predeterminate conditions or values. These values or conditions are stored in any desired form on a data carrier, for example in the form of a curved guide template or as a cam guide disk, in the form of a measuring point or pulse regulation by sensing the machining tool or grinding wheel for signs of wear or its optimization or for better tool exploitation, or in the form of a pulse generator, an electronic data carrying medium, mass memory or the like. Especially the latter, either by themselves or in conjunction with measuring point regulation, can contain empirical values which have been found to produce optimal flank surface properties.
The traversing feed motion is carried out in a manner known per se when grinding gear tooth flanks without topographical or geometric corrections. If the case should arise that a tooth flank is to be ground with a topographical or geometric correction, i.e. with a profile which varies over the width of the tooth, then either the correction motion is superimposed on the feed motion or a correction motion is supplementarily, i.e. entailing more than one step, performed. This is essentially a question of control depending on which value is taken as a reference value, respectively as an initial value, for the feed motion. It is necessary to fully traverse in each correction point from this reference value in a single step or a number of steps. The assignment of the correction values to the individual points of the tooth flank is known per se and is preferably done in a coordinate system of the field of action or machining engagement. Either the workpiece or gear blank or the machining tool or grinding wheel can perform the traversing motion.
The working or machining line of the embodiment of the method hereinbefore described can take the form of a zig-zag line whose individual segments each extend essentially along a generatrix of the tooth flank (cf. FIG. 8). In practice, however, the actual working or machining line will always deviate somewhat from the theoretical working or machining line. When using this working or machining line either the workpiece or gear blank or, for very large workpieces or gear blanks, the tool or grinding wheel performs a continuous generating feed motion. In addition, the machining tool or tools are moved along the surface of the tooth flank with an oscillating or stroking feed motion. Another form is a meandering or wandering type of work or machining line in which the working or machining point is guided along a generatrix, or at least approximately along a generatrix, as one branch of the segment during a stroke or stroking feed motion. For changing or switching over from one generatrix to a generationally relevant adjacent generatrix, the working or machining point is guided along a profile line, possibly a tooth or flank line as a second branch or segment of the working or machining line. This depends on the position of the turning or reversing point relative to the tooth flank in the course of motion of the grinding process. A discontinuous generating feed motion of the workpiece or gear blank or a corresponding motion of the machining tool or tools results from this configuration of the working or machining line when the machining tool or tools move about the stationary workpiece or gear blank. In this way the machining tool or tools perform the supplementary stroke or stroking feed motion.
In a further embodiment of the method for fabricating involute gear tooth flanks, the workpiece or gear blank is, as usual, clamped to a work or machining table which performs generating feed motions. If the work table, in addition to the continuous generating feed motion, is also rotated and either the work table or the machining tool or tools are moved in accord therewith in the direction of the axis of the gear, then the working or machining point is displaced along a working or machining line in the form of a helical or spiral zig-zag line on the tooth flank (tooth trace or flank line envelope). The generating feed motion, the rotary motion and the axial feed motion are to be carried out such that they are mutually adapted to or match each other so that the working or machining point always lies on the tooth flank. Therefore a helical or spiral motion is superimposed onto a generating motion. The grinding wheel or disk carries out a supplementary feed motion whose direction of motion lies in the working or machining plane or surface of the grinding wheel or disk, i.e. lies in a tangential plane of the tooth flank, so that the selectable working or machining point or its immediate vicinity (the size of which depends on the form of the grinding wheel) is essentially always guided along this working or machining line.
The control of these motions can be the result of a combination of electro-mechanical control utilizing known means, for example for generating the generating feed motion, and of individual motor drive means, in which appropriate position sensors are connected to the regulating and control circuits. It is, however, also possible to control these movements purely electronically with the reference values stored on the most various forms of data storage medium, for example mechanical data storage media such as cam discs or template bars et cetera, magnetic data storage media, optical data storage media et cetera and, by means of the appropriate means for reading-out and transmission and control, to transmit these values to the drive means.
Discontinuous control of the generating feed motion is also possible, although it can only be carried out in steps or increments. The working or machining point is guided along a helical or spiral line of the tooth flank and in the region of the flank end an incremental switch or change movement is undertaken in the form of a generating feed motion which permits the subsequent generatrix envelope to occur. In this way, one generatrix envelope is juxtaposed with another generatrix envelope. The generating feed motion can be performed either by the workpiece or gear blank or by the at least one machining tool or grinding wheel. The working or machining line then has a meandering course or path and its segments consist of two branches: a tooth trace or flank line and a profile line. Consequently, the profile line will, in general, lie on the virtually extended tooth flank, i.e. outside the gear tooth flank. The supplementary generating feed motion of the machining tool must be performed in accordance with the incremental feed motion, i.e. the generating motion, in order that the working point, despite the incrementation, be maintained in the same position relative to the working or machining surface of the machining tool, i.e. the grinding wheel or disk.
If it is required that the working or machining point be continuously or discontinuously displaced within the working area or machining region of the machining tool in order to achieve a uniform wear of the machining tool or to adapt the wear of the machining tool to the economic factors of the machining operation, i.e. to optimize machining tool wear in relation to the machining operation, then a further working or machining point motion is performed. This can be superimposed on the supplementary feed motion or can be undertaken separately from it. The variably selectable working or machining point, also called the operative point, is displaced relative to the machining tool on its working or machining surface, i.e. on the effective cutting area or region of the grinding wheel. This can be achieved continuously according to a spiral line, discontinuously by circular lines or possibly via random number control in order to achieve the most uniform and patternless wear possible of the grinding wheel or disk.
This further embodiment of the inventive method also allows topographical or geometric correction traversing motions to be performed in addition to the normal traversing motion. These correction motions can be controlled in a known manner from the field of action or of machining engagement and can be performed either purely rotationally or translationally by the workpiece or gear blank as well as by the machining tool or grinding wheel.
A further motion can be performed in each of the embodiment of the method, namely the generally noncontinuos adjustment of the tool support by a variation amount of the helix angle β of helical teeth. This adjustment makes possible, especially when employing dished grinding wheels or disks of conventional construction, a substantial reduction of the circumference of the working or machining point to almost exactly a point. This motion, just as the other motions, can also be performed by a control program. Here, too, the program can be stored on mechanical or magnetic storage media and can be brought into service by means of appropriate data transmission means, for instance mechanical, optical, electrical or magnetic means.
Depending on the working line, a different generatrix envelope network results from each of these embodiments of the method. This generatrix envelope profile network can be optimally configured by means of an appropriate adjustment or matching of the feed and traversing motions with respect to the corresponding variables.
If methods with helical or spiral working lines are employed, or if methods with helical or spiral lines which consist of various component segments are employed, then there results the important advantage that the tool support or head of the machine tool or gear cutting machine is moved not along an inclined straight line but rather along a vertical. Consequently, the machine is not loaded by the displacement of the weight of the tool head, a load which may be quite considerable depending on the operating speed. This contributes substantially to the fabrication accuracy of the workpieces or gears.
It represents an important advantage if the correction traversing motion can be performed by the machining tool, since workpiece or gear blank motion is then saved. In this way the stability of the machine can be substantially increased and vibrations can be avoided.
Depending on the application, in the embodiment of the method with helical or spiral component segments for the machining line, the generatrix envelope can be controllably concentrically or quasi-concentrically altered, on the one hand, and controlled in width, on the other hand. In particular, the generatrix envelope widths in the region of the tooth head or addendum and the tooth root or dedendum can be carried out in different widths.
If only simple dedendum or addendum corrections are to be performed, then they can be generated when employing the tooth trace or flank line envelopes by means of simple relative motions. In principle, the calculation and execution of flank corrections is simpler in this case, since the envelopes of tooth trace or flank lines are limited. For example, the same values are used during a complete grinding stroke in normal profile corrections. With the choice of appropriate values for the correction parameters, profile corrections can also be generated by tangential motions. It is also basically possible to make use of corrected tools, for example grinding wheels or disks or milling face or side cutters. Slot milling cutters or end mills or the like can also be used. Analogously, the same values are always set for each envelope when performing longitudinal corrections.
In each of the described exemplarily embodiments of the inventive method, that is with a generatrix machining line and with helical or spiral component segments in the working or machining line, it is advantageous that topographical or geometric corrections can be performed much more accurately than heretofore, since they are generated using practically a single working or machining point and the desired correction values are freely prescribable. Furthermore, grinding wheels with flat or conical working or machining surfaces can be used. These working or machining surfaces are easily produced and maintained.
The choice between both variations of the method will be made according to the individual application. If, for example, it is required that only very small or almost no profile differences should occur between the tooth ends and the tooth center and it is necessary to work with a continuous generating feed motion, then the method described as the second examplary embodiment and having helical or spiral lines as segments or components of the working or machining line will be particularly advantageous.
Neither of the two embodiments of the method require tools which are specific to the workpiece or gear blank and none of them require tool correction devices with the associated maintenance and inspection work.
FIG. 14 depicts an exemplary embodiment of a machine tool or gear cutting machine for performing the method of the invention for fabricating a gear wheel 1.0 using generatrices as the working or machining line. There is provided, as usual, a machine frame 1.1 which on one side carries a displaceable or translatable generating motion carriage or slide 1.2 and on the other side a cross or transverse slide or carriage or multi-carriage arrangement 1.3 of a type known per se and which is swivellably mounted for adjusting the tooth helix angle. A tool support 1.4, on which a machining tool or tools, for example grinding wheels or disks 1.5, are seated or fastened, is fixed to the cross or transverse slide or carriage arrangement 1.3. A correspondingly adjustable feed slide or carriage 1.6 is provided for carrying out the supplementary feed motion with which the working or machining point of each of the grinding wheels or disks 1.5 is guided tangentially to the gear tooth flank to be fabricated. Preferably, motion or displacement transducers or other position indicators or sensors 1.7 are provided on all of the slides or carriages. These position indicators or sensors 1.7 are connected with a control arrangement 2.0 (shown in FIG. 13). This control arrangement 2.0 can be either purely electronic or a mechanically and electronically operated control means. For example, the generating motion can be derived in conventional manner from a generating tape control means. The drive motors also possess rotary speed transducers 2.2 (FIG. 13) which are connected with the control arrangement 2.0. For the sake of expository simplicity, it will be assumed that the machine tool shown in FIG. 14 contains an electromechanical control means in which the generating tape control means is of a type known per se and therefore not shown in FIG. 14 and also not described in detail here.
Such a control means (cf. FIG. 13) possesses a master computer or control processor 2.3 which contains and runs the basic control program. It is connected with a master control interface 2.4 for controlling and monitoring each tool support 1.4 as well as the other not particularly mentioned motions such as, for instance, the stroke or stroking feed motions, the adjustment motion of the tooth helix angle and its deviations from the reference value, positional motion of the workpiece or gear blank as well as other necessary and known movements. This master control interface 2.4 is connected to each of the following control and monitoring devices:
a grinding wheel control means 2.5 for the grinding wheel or disk;
a carriage control means 2.6 for controlling pressure angle, tooth helix angle and intermediate slide motion;
a supplementary feed control means 2.7 for the supplementary feed motion;
a traversing control means 2.8 for the traversing motion as well as the normal cutting or grinding, i.e. machining motion and also the normal and topographical or geometric correction motions; and
a wear control means 2.9 for the grinding wheel measuring device for measuring grinding wheel wear and for performing diameter compensation et cetera.
A regulator 2.51 is connected to the grinding wheel control means 2.5 and also to a grinding wheel drive means 3.1. A rotary speed transducer or measuring means or system or tachometer 2.2 is connected to the grinding wheel drive means 3.1 and is also connected to the grinding wheel control means 2.5. This feedback regulation circuit serves for accurate revolution or speed regulation in cooperation with the other controlled motions and machine functions.
The carriage control means 2.6 for intermediate slide or carriage motion, pressure angle and helix angle is connected to a monitoring arrangement 2.62 for position feedback and a second regulator 2.61 which is connected on one side to an intermediate slide or carriage drive means 3.2 for positioning each of a first or right hand control axis U R and a second or left hand control axis U L of the machine tool or gear cutting machine illustrated in FIG. 12 and on the other side with a drive means 3.3 for adjusting the pressure angle α or the tooth helix angle λ or both. The intermediate slide or carriage drive means 3.2 is connected to a position indicator or sensor 2.63 which in turn is connected with the carriage control means 2.6 for controlling pressure angle, helix angle and intermediate slide or carriage motion. The drive means 3.3 for adjusting the pressure angle α or the tooth helix angle β or both is also connected to a position indicator or measuring system 2.64 (which is not shown in FIG. 8 due to the conical grinding wheels employed), whose measuring data is transmitted to the carriage control means 2.6 for controlling pressure angle, helix angle and intermediate slide or carriage motion. The reference data for each position are transmitted to this carriage control means 2.6 by the master control interface 2.4 and the carriage control means 2.6 returns its own data back to the master control interface 2.4.
The supplementary feed control means 2.7 for the supplementary feed motion is also connected through its input and output means to the master control interface 2.4 and is connected through an input means to a monitoring interface 2.72 for monitoring the positions of the controlled components. The supplementary feed control means 2.7 is also connected to a third regulator 2.71 which controls the drive means 3.4 for the supplementary feed motion. A position measuring system or indicator 2.73 is connected to this drive means 3.4. The position measuring system 2.73 feeds its measuring data for the supplementary feed motion to the supplementary feed control means 2.7.
A monitoring means 2.82 for the end or reversing positions and the working or machining positions of the guide means is connected to the traversing control means 2.8 for the normal and the topographical or geometric corrections of the tooth flanks. A fourth regulator 2.81 for the drive means 3.5 of the traversing and correction motions of the machining tool or each machining tool 1.5 is connected to the traversing control means 2.8. This drive means 3.5 can also cooperate with a machine axis which is associated with a workpiece or gear blank so that the traversing motion is performed by the workpiece or gear blank 1.0. A position measuring system or indicator 2.83 is connected to this drive means 3.5 and transmits its signals to the traversing control means 2.8 for the traversing and correction motions.
The measuring control or wear measuring and control means 2.9 is for controlling, monitoring and processing measurement data and is connected to measurement and position indicator means as well as monitoring means and drive output means. It communicates with the master computer or control processor 2.3 through the master control interface 2.4.
All these control means 2.5 to 2.9 communicate with the master control interface 2.4 and the master control interface 2.4 exchanges signals or data with the master computer or control processor 2.3 so that all motions are interrelated and controlled in accordance with the regulating and measuring data.
In FIG. 12 only the most important machine axes to be controlled are shown. These are:
W L , W R =two, i.e. left and right hand, branches or segments of the generating motion;
rfs=positional axis between machining tool or tools and workpiece or gear blank;
U TL ,U TR =left and right hand traversing axes for machining traverse and correction traverse;
O L ,O R =left and right hand axes of the supplementary feed motions;
α SL ,α SR =left and right hand pressure angle adjustment axes;
U L ,U R =left and right hand intermediate slide or carriage axes;
βs, Δβs=tooth helix angle and its variations;
h=machining tool or grinding wheel stroke.
Grinding wheels or disks are preferably utilized as the machining or grinding tools 1.5. These can have the well-known basic form which is substantially that of a dish or disk or that of a double cone, as is shown in FIGS. 10a and 10b. In consequence of the supplementary feed motion utilized according to the method of the invention, the working areas or machining regions of the grinding wheel or disk can be kept substantially narrower than in heretofore known grinding methods. A particularly advantageous form of grinding wheel or disk is shown in FIG. 10c. This type of grinding wheel is a modified dished wheel or disk and possesses instead of a planar working or machining surface a conical frustum having an included or cone angle slightly less than 180°. This form of grinding wheel or disk unites the advantages of the dished wheel with those of the conical wheel.
An exemplary apparatus for carrying out the grinding method of the invention employing a working or machining line with helical or spiral component segments can be very similar to the apparatus hereinbefore described. This apparatus also comprises a machine frame 1.1 which on one side carries a displaceable generating carriage or slide arrangement and on the other side a pivotably mounted cross or transverse slide or carriage arrangement 1.3 known per se for adjusting the helix angle. However, for the helical or spiral working or machining line, at least one component or portion of the slide or carriage complex must be guidable parallel to the axis of the machining tool in a stroke feed motion. For this purpose, a further slide 1.10 in accordance with FIG. 15b or an addition swivel axis 1.11 in accordance with FIG. 15a must be provided between the machine frame 1.1 and one slide or carriage. Alternatively, the motions are so controlled that the resultant motion is identical with this stroke feed motion. The difference lies essentially in the temporal control of the individual motions for achieving the tooth flank form.
The control of these motions can be most readily realized by means of an arrangement of individual drives or drive means for each motion. The tooth helix is in this case achieved not through a stroke motion of a stroke slide or carriage or a corresponding slide or carriage arrangement performed at an inclination towards the gear axis, but by means of a slide or carriage which is displaceable parallel to the gear axis.
In order to employ the helix or spiral as a component segment of the working or machining line, the workpiece is rotated on the workpiece carrier or support. Only at the end of the tooth trace or flank line is the incrementation performed for generating the next envelope of the workpiece or ear blank by means of the generating drive means utilizing either an electronically controlled drive means or a conventional generating tape control means.
For carrying out the normal or the topographical or geometric corrections, control means are provided which cooperate with the drive means for the individual motion axes. The operating sequence of the motions is determined by mechanical, magnetic, optical or electrical storage media. The motions can be carried out such that the correction traverses of the machining tool are purely rotary, purely translatory or a combination of the two. To achieve this, the drive mean are activated so that the desired resultant motions arise. The supplementary rotation or angular displacement of the gear or rotary table, i.e. the work or machining table, amounts to:
nt=Fk/db (3)
wherein:
Fk=Flank correction value
db=Base circle diameter
nt=Supplementary motion of the gear or rotary table
The control means for generatrix envelope optimization is also similarly stored on storage media as a sequence of signal sequences cooperating with position indicators and can be fed into the control means for the individual motion sequences. The required freedom of play in the drive can only be achieved with great difficulty or with great design outlay when employing prior art drives. For instance, a double-worm drive would be necessary for the gear or rotary table. With the inventive individual drive arrangement controlled by command sequences, this play can be achieved very easily.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. | An apparatus is disclosed in which only one working point or machining point on a machining tool, which in general can comprise a grinding wheel or disc, is in machining contact with a workpiece such as a gear blank during a machining operation. The position of this single working or machining point can be selectively chosen within a machining region of the grinding wheel or disk and can be prescribed to lie in a zone of fixed or variable radius of the grinding wheel or disk. This is achieved through at least one feed motion, in general a feed motion of the grinding wheel or disc, effected in addition to feed motions known per se in machining processes performed essentially according to the indexing generating method. This means that the machining contact point between the grinding wheel or disk and the gear blank does not wander on the grinding wheel or disk in correspondence with the generating feed motions but can be confined to a predeterminate region. It is nevertheless possible to displace this working or machining point in an orderly and programmed manner, i.e. under control, to optimally exploit the machining tool. In accordance with the method, the machining point can be guided along different types of machining lines, for example along lines which at least approximate tooth flank generatrices or along lines which at least approximate tooth traces or flank lines and which may be helical. | 1 |
FIELD OF THE INVENTION
This invention relates to bottom feed fuel injectors for internal combustion engines and to improved embodiments and methods of manufacture for such injectors.
BACKGROUND OF THE INVENTION
In the art relating to engine fuel injectors for fuel delivery to engine induction systems, the commonly used types of injectors fall into two categories. These are top feed injectors wherein fuel is fed to the injector through an opening at the upper end and bottom feed (sometimes called side feed) injectors wherein fuel is fed to the injector through side openings located near the outlet nozzle end of the injector. Because of differences in the design, as well as the manner of fuel feed, these two types of injectors have traditionally been manufactured on separate assembly lines. This requirement adds to the cost of manufacture and limits flexibility as to the amounts of different types of injectors which may be economically produced.
Recently proposed injector assembly techniques have opened the possibility of having common components between bottom feed and top feed injector designs, allowing assembly of either type of injector on the same equipment. However, because of the differences in the fuel feed arrangements for the two injector types, the necessity continues for having a separate calibration and assembly line with different forms of fuel feeding equipment.
SUMMARY OF THE INVENTION
The present invention provides improved embodiments of bottom feed injectors which utilize calibration means similar of those of top feed injectors and allow fuel for calibration and run in to be delivered through the top of the injector in the same manner as with top feed injectors. Means for blocking off the side inlet ports of the bottom feed injector must also be provided on the line. Thus, both top feed and bottom feed injectors are able to be assembled, calibrated and run in on the same manufacturing line, reducing the overall manufacturing cost and increasing flexibility.
These and other features and advantages of the invention will be more fully understood from the following description of certain exemplary embodiments of the invention taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a longitudinal cross-sectional view of a bottom feed fuel injector formed according to the invention;
FIG. 2 is a cross-sectional view similar to FIG. 1 but showing the injector of FIG. 1 during calibration on the assembly line;
FIG. 3 is a fragmentary cross-sectional view of an injector having an alternative embodiment of sealing and adjusting means;
FIG. 4 is a view similar to FIG. 3 but showing but showing another embodiment of alternative sealing and adjusting means; and
FIGS. 5-11 are fragmentary cross-sectional views illustrating alternative embodiments of sealing means.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings in detail, numeral 10 generally indicates a bottom feed fuel injector in accordance with the invention. Injector 10 includes an over-molded plastic upper housing 12 including a connector 14. The housing 12 surrounds upper portions of an inlet tube 16 and a coil housing assembly 18 enclosing an annular magnetic coil 20 disposed around the lower end of the inlet tube 16 and having a common axis 22 therewith. Below the coil 20 is a valve body 24 in which an armature 26 is reciprocally disposed. The armature forms an assembly with a valve needle 28, the lower end of which normally engages a valve seat 30 having an outlet orifice 32. The valve seat 30 is received within a lower recess portion of the valve body together with a needle guide 34 above the valve seat and a backup washer 36 below having a central opening 38 aligned with the orifice 32.
The valve needle is normally urged against the seat 30 by a spring 40 which engages the upper end of the armature 26. The spring 40 is compressed by an adjusting tube 42 which is received with a friction fit within the inlet tube 16. The adjusting tube 42 is longitudinally adjusted within the inlet tube 16 to calibrate the spring force during manufacturing and is preferably staked or otherwise fixed in place after calibration, such as at the location of circle 44.
An outer plastic shell 46 covers the lower portion of the injector surrounding the upper portion of the valve body 24 and extending axially between upper and lower O-ring seals 48, 50 respectively. Between the seals 48, 50, radial openings 52 through the shell 46 join connecting openings 54 in the valve body to permit fuel flow from the exterior of the injector between the O-rings into an annular chamber 56 surrounding the valve needle 28. A filter screen 58 surrounds the valve body between openings 52 and 54.
In normal operation in an engine, fuel is admitted to the injector through the bottom (side) openings 52, 54, filling the chamber 56. When the coil 20 is energized, it attracts the armature 26 and unseats the valve needle 28 from the seat 30, allowing fuel to flow through openings 60 in the needle guide, past the valve seat and out through orifice 32 and opening 38 into an associated engine intake manifold or cylinder head not shown.
In prior bottom feed injectors, the spring force calibrating device is a solid rod forced into the inlet tube against the spring 40 and staked in place after calibration. One or more O-ring seals are located in grooves on the rod in order to prevent fuel leakage from the annular chamber 56 up through an opening 62 in the armature and out through the top of the injector. An additional closure seal in the form of a disk 64 is usually provided to close the housing opening.
The present invention differs from the prior art in the use of a hollow adjusting tube 42 of the type that is usually limited to use in top feed injectors. During manufacture of the injector on the assembly line, the injector is assembled to a finished state except that the closure disk 64 is not installed at this point, as is shown in FIG. 2. The injector 10 is then placed in a fixture 66 which encloses the lower inlet openings 52, 54 between upper and lower seal rings 68, 70 respectively. These prevent the passage of fuel into or out of the inlet openings 52, 54. The injector is then connected with an alternative source of fuel delivery to the open top of the injector in the form of a nozzle 72 which sealingly engages a recess 74 in the top of the injector housing. Nozzle 72 also engages the inlet end of the adjusting tube 42 so as to deliver fuel through a passage 76 in the nozzle to the interior of the adjusting tube 42.
Calibration of the injector by adjusting as necessary the position of the adjusting tube is conducted during manufacture with top feeding of the fuel in substantially the same manner as top feed injectors are fed during manufacture. If desired the injector may also be run in using the top feed fuel nozzle. After the calibration and run in steps are completed, the top end of the injector is sealed by application of the closure disk 64 as shown in FIG. 1. The injector is then ready for use in an engine wherein the fuel will be bottom fed through the side port openings 52, 54 as previously discussed.
The manner of blocking the openings 52, 54 and feeding fuel to the upper end of the injector as shown in FIG. 2 is intended to be representative only and not to limit the manner in which these functions may be carried out, since any suitable manner of accomplishing them may be utilized. In like manner, closing of the upper end fuel feed opening may be performed in any suitable manner. However, a number of possible alternative embodiments are shown in FIGS. 3 through 11 to be subsequently described.
FIG. 3 illustrates an alternative embodiment of injector 110 which differs from injector 10 in two ways. First, a roll pin 142 is used in place of the normal adjusting tube 42 for calibrating and retaining the injector valve spring in its calibrated position. The roll pin is sized to fit within the lower bore of the inlet tube 116 with a snug fit so as to be useable in the same manner as the adjusting tube previously described. Second, the inlet tube 116 is extended beyond the upper housing 112 and the open end is closed by a disk 178 hermetically welded to the end of the tube 116. A cup shaped cap 180 is then provided which snaps over a retainer ring 182 held in a groove on the inlet tube exterior to retain the cap 180 in place covering the exposed metal of the disk 178 and tube 116 to maintain its appearance.
FIG. 4 shows an injector 210 which is similar to injector 110 except that it has a different form of adjusting means and top closure. An adjusting rod 242 is retained within the inlet tube 216 in place of the usual adjusting tube. Rod 242 has an enlarged lower end 284 engaging the valve spring and an enlarged upper end 286 fixed within the inner bore of the inlet tube 216. Passages 288 through the enlarged ends provide for fuel flow from the top feed through the upper end, around the reduced diameter of the adjusting rod 242 between its ends, and through the lower end 284 into the spring for delivery down through the fuel passage to the needle valve, not shown. The extended upper end of the inlet tube 216 is closed by a resilient disk 290 or an O-ring retained in place by a metal cap 292 which may be hermetically welded to the inlet tube exterior to provide, with the disk 290, a double seal against fuel leakage.
FIGS. 5 and 6 show alternative forms of upper closures in which an exterior O-ring 394 or 494 is retained in place on the inlet tube 316, 416 by a covering cap 392, 492. In FIG. 5, cap 392 is welded in place while in FIG. 6 cap 492 is retained by a clip or other retaining means.
FIG. 7 illustrates one form of internal O-ring 594 received within the end of the inlet tube 516 and retained in place by a cap 592 which may be welded in any suitable manner to the inlet tube or retained on it in any other suitable manner.
FIGS. 8 through 10 illustrate variations of a ball seal retained within the inlet tube of the associated injector. In FIG. 8, a deformable ball 696 is pressed into the end of the inlet tube 616 and is retained there by friction forces due to the press fit. In FIG. 9, an elastomeric ball 796 is forced into the end of the inlet tube 716 and is held in place by a closure disk 764 welded or otherwise retained on the end of the inlet tube. In FIG. 10, an elastomeric ball 896 is retained in place in the inlet tube 816 by a snap cap 892 clipped to the plastic housing 812 on the injector.
FIG. 11 differs in that the interior of the inlet tube 916 outer end is closed by a short piece of cylindrical rod 998 which is grooved to receive an internal O-ring 994 that provides the seal. The rod may be crimped, staked or welded in place within the inlet tube 916.
While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but that it have the full scope defined by the language of the following claims. | A bottom feed engine fuel injector is provided with a valve spring calibration adjuster such as an adjusting tube, which permits fuel flow from the top of the injector during manufacturing calibration and run in. The upper end of the injector is capped in the last manufacturing step after calibration to prevent fuel passage through this opening in normal engine use where bottom fuel feed is used in conventional fashion. Several exemplary adjusters and top feed closing embodiments are illustrated and described. The modified injector structure and manufacturing process reduces costs by allowing both top and bottom feed injectors to be assembled and calibrated on the same manufacturing equipment. | 5 |
CROSS-REFERENCE TO RELATED PATENT APPLICATION
The present application is a Divisional application of application Ser. No. 12/644,370, filed Dec. 22, 2009 now U.S. Pat. No. 8,236,692; which claims priority under 35 U.S.C. §119 of Japanese Patent Application Nos. 2008-329416, filed on Dec. 25, 2008, and 2009-267530, filed on Nov. 25, 2009, in the Japanese Patent Office, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cleaning control apparatus and a substrate processing apparatus capable of cleaning inside thereof. More particularly, the present invention relates to a cleaning control apparatus and a substrate processing apparatus capable of cleaning inside thereof by supplying a cleaning gas into a process chamber and a gas supply system thereof to remove deposition substances attached to an inside thereof after forming a film on a substrate.
2. Description of the Prior Art
In a conventional substrate processing apparatus, when a process gas is supplied, the process gas is distributed not only to the surface of a substrate but also to other parts (for example, the inside of a process chamber), and thus unnecessary films may be accumulated and deposited as attached substances. Such attached substances may include impurities harmful for a substrate processing process, and thus, substrates may be contaminated due to the attached substances.
Therefore, so as to prevent or suppress such a problem, in addition to the supply of a process gas to the process chamber, a cleaning gas is also supplied to the inside of the process chamber (particularly, parts where it is expected that substances are attached) so as to remove substances attached to the inside of the process chamber by converting the substances into harmless gas and then discharging the harmless gas. That is, self-cleaning is performed (for example, refer to Patent Document 1).
PATENT DOCUMENT 1
Japanese Patent No. 3985899
However, since at least a reaction tube configured to place a substrate therein and a process gas supply nozzle configured to supply a process gas to the reaction tube are disposed in the process chamber, different films may be deposited on the inside (inner wall or other parts) of the reaction tube and the inner wall of the process gas supply nozzle according to a method used to supply a process gas to the inside of the process chamber.
Exhaust resistance is caused according to the length of the gas supply nozzle or the shape of a gas supply hole, and if the exhaust resistance is high, the inside pressure of the gas supply nozzle becomes higher than the inside pressure of the reaction tube. In this case, generally, since the reaction rate of a process gas increases as pressure increases, the thickness of a film deposited on the inner wall of the gas supply nozzle becomes greater than the thickness of a film deposited on the inside of the reaction tube. Moreover, according to the kind of chemical reaction, the properties of films such as a crystalline structure may be changed.
By using a silicon source and a nitriding source as process gases, a silicon nitride film can be formed on the surface of a substrate.
In this case, to prevent generation of a reaction byproduct, the process gases are supplied to a process chamber via separate gas supply nozzles. At this time, a silicon film may be formed, due to decomposition of the silicon source, on the inner wall of a first nozzle through which the silicon source is supplied, although formation of a film caused by decomposition of the nitriding source is not observed at the inner wall of a second nozzle through which the nitriding source is supplied. In addition, a silicon nitride film is formed on the inside of a reaction tube as an attached substance. That is, different films may be formed on the inside of the reaction tube and the inner wall of the gas supply nozzle.
In the case where films having different qualities and thicknesses are formed on the inside of the reaction tube and the inner wall of the gas supply nozzle, if a cleaning process is performed under normal conditions, there may arise disadvantages such as an increase of cleaning time, generation of contaminants, and damages on the reaction tube and the gas supply nozzle. Moreover, if a cleaning process is performed under normal conditions, the inner wall of the gas supply nozzle may be etched more rapidly than the inside of the reaction tube.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method of manufacturing a semiconductor device, a cleaning method, and a cleaning control apparatus that are designed to perform a cleaning process efficiently on the inside of a process chamber while reducing generation of contaminants and damages on a reaction tube and a gas supply nozzle.
According to an aspect of the present invention, there is provided a substrate processing apparatus comprising: a process chamber accommodating a substrate; a first gas introducing part configured to supply a first source gas and a cleaning gas into the process chamber, the first source gas comprising at least one of a plurality of elements; a second gas introducing part configured to supply a first second gas into the process chamber, the second source gas comprising at least one of the plurality of elements other than those of the first source gas; a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed, the third gas introducing part being configured to supply the cleaning gas into the process chamber; an exhaust unit configured to exhaust an atmosphere inside the process chamber; and a controller configured to control the first gas introducing part, the second gas introducing part, the third gas introducing part and the exhaust unit to perform, after depositing a film on the substrate by supplying the first source gas and the second source gas into the process chamber: a first cleaning process so as to remove a first deposition substance attached to an inner wall of the first gas introducing part by supplying the cleaning gas to the first gas introducing part wherein a cleaning condition is set according to an accumulated supply time of the first source gas supplied into the process chamber through the first gas introducing part; and a second cleaning process so as to remove a second deposition substance attached to an inside of the process chamber and having a different chemical composition from that of the first deposition substance by supplying the cleaning gas into the process chamber through the third gas introducing part wherein the cleaning condition is set according to an accumulated thickness of the film formed on the substrate.
According to another aspect of the present invention, there is provided a substrate processing apparatus comprising: a process chamber accommodating a substrate; a first gas introducing part configured to supply a first source gas and a cleaning gas into the process chamber, the first source gas comprising at least one of a plurality of elements; a second gas introducing part configured to supply a first second gas into the process chamber, the second source gas comprising at least one of the plurality of elements other than those of the first source gas; a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed, the third gas introducing part being configured to supply the cleaning gas into the process chamber; an exhaust unit configured to exhaust an atmosphere inside the process chamber; and a controller configured to control the first gas introducing part, the second gas introducing part, the third gas introducing part and the exhaust unit to intermittently supply the cleaning gas into the process chamber through third gas introducing part with an inside pressure of the process chamber set at a first pressure, and to continuously supply the cleaning gas into the process chamber through third gas introducing part with the inside pressure set at a second pressure lower than the first pressure after depositing a film on the substrate by supplying the first source gas and the second source gas.
According to another aspect of the present invention, there is provided a cleaning control apparatus for a silicon nitride film forming apparatus configured to form a silicon nitride film on a substrate accommodated in the process chamber by alternately supplying a silicon-containing gas through a silicon-containing gas supply system and a nitriding source gas through a nitriding source gas supply system, the cleaning control apparatus comprising: a first cleaning request signal output unit comprising a first memory unit configured to store an accumulated amount of molecules of the silicon-containing gas supplied into the process chamber through the silicon-containing gas supply system, the first cleaning request signal output unit being configured to output a first cleaning request signal to request a cleaning of the silicon-containing gas supply system when the accumulated amount of the molecules of the silicon-containing gas stored in the first memory unit is equal to or greater than a preset accumulated amount of the molecules of the silicon-containing gas; and a second cleaning request signal output unit comprising a second memory unit configured to store an accumulated amount of molecules of the nitriding source gas supplied into the process chamber through the nitriding source gas supply system, the second cleaning request signal output unit being configured to output a second cleaning request signal to request a cleaning of the nitriding source gas supply system when the accumulated amount of the molecules of the nitriding source gas stored in the second memory unit is equal to or greater than a preset accumulated amount of the molecules of the nitriding source gas.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view illustrating a vertical process furnace of a substrate processing apparatus suitable for an embodiment of the present invention.
FIG. 2 is a sectional view taken from line A-A′ of FIG. 1 .
FIG. 3 is a flowchart for explaining a film-forming method according to an embodiment of the present invention.
FIG. 4 is a flowchart for explaining a cleaning method according to an embodiment of the present invention.
FIG. 5 is a flowchart for explaining a cleaning method according to an embodiment of the present invention.
FIG. 6 is a flowchart for explaining a cleaning method according to another embodiment of the present invention.
FIG. 7A and FIG. 7B are views illustrating control units according to an embodiment of the present invention.
FIG. 8 is a schematic view illustrating a vertical process furnace of a substrate processing apparatus suitable for another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be described hereinafter with reference to the attached drawings.
(1) Structure of Substrate Processing Apparatus
FIG. 1 is a schematic vertical sectional view illustrating a vertical process furnace 202 of a substrate processing apparatus suitable for an embodiment of the present invention. FIG. 2 is a sectional view taken from line A-A′ of FIG. 1 .
As shown in FIG. 1 , the process furnace 202 includes a heater 207 used as a heating unit (heating mechanism). The heater 207 has a cylindrical shape and is vertically installed in a state where the heater 207 is supported on a heater base (not shown) which is a holding plate.
Inside the heater 207 , a process tube 203 is installed concentrically with the heater 207 as a reaction tube. The process tube 203 is made of a heat-resistant material such as a quartz (SiO 2 ) or silicon carbide (SiC) and has a cylindrical shape with a closed top side and an opened bottom side. The hollow part of the process tube 203 forms a process chamber 201 and is configured to accommodate substrates such as wafers 200 by using a substrate holder such as a boat 217 (described later) in a manner such that the wafers 200 are horizontally positioned and vertically arranged in multiple stages.
At the lower side of the process chamber 201 , a first nozzle 233 a and a second nozzle 233 b are installed as a first gas introducing part and a second gas introducing part, and a first gas supply pipe 232 a and a second gas supply pipe 232 b are connected to the first nozzle 233 a and the second nozzle 233 b , respectively. In this way, as gas supply passages for supplying a plurality of kinds of gases (in the current embodiment, two kinds of gases) to the inside of the process chamber 201 , two gas supply pipes are installed. In the structure, the lower side of the process chamber 201 is a region where no wafer 200 is placed, and the lower side of the process chamber 201 is not a heating region.
At the first gas supply pipe 232 a , a flowrate controller (flowrate control unit) such as a first mass flow controller (MFC) 241 a , and an on-off valve such as a first valve 243 a are sequentially installed from the upstream side of the first gas supply pipe 232 a . In addition, the first nozzle 233 a is connected to the leading end of the first gas supply pipe 232 a . In an arc-shaped space between the inner wall of the process tube 203 constituting the process chamber 201 and wafers 200 , the first nozzle 233 a is installed in a manner such that the first nozzle 233 a extends from the lower side to the upper side along the inner wall of the process tube 203 in a direction in which the wafers 200 are stacked. First gas supply holes 248 a are formed through the lateral surface of the first nozzle 233 a . Along the lower side to the upper side, the first gas supply holes 248 a are formed in a manner that the first gas supply holes 248 a have the same size and are arranged at the same pitch. A first gas supply system is mainly constituted by the first gas supply pipe 232 a , the first MFC 241 a , the first valve 243 a , and the first nozzle 233 a.
At the second gas supply pipe 232 b , a flowrate controller (flowrate control unit) such as a second MFC 241 b , and an on-off valve such as a second valve 243 b are sequentially installed from the upstream side of the second gas supply pipe 232 b . In addition, the second nozzle 233 b is connected to the leading end of the second gas supply pipe 232 b . In an arc-shaped space between the inner wall of the process tube 203 constituting the process chamber 201 and the wafers 200 , the second nozzle 233 b is installed in a manner such that the second nozzle 233 b extends from the lower side to the upper side along the inner wall of the process tube 203 in a direction in which the wafers 200 are stacked. Second gas supply holes 248 b are formed through the lateral surface of the second nozzle 233 b . Along the lower side to the upper side, the second gas supply holes 248 b are formed in a manner that the second gas supply holes 248 b have the same size and are arranged at the same pitch. A second gas supply system is mainly constituted by the second gas supply pipe 232 b , the second MFC 241 b , the second valve 243 b , and the second nozzle 233 b.
For example, dichlorosilane (SiH 2 Cl 2 , abbreviation: DCS) gas may be supplied from the first gas supply pipe 232 a to the inside of the process chamber 201 through the first MFC 241 a , the first valve 243 a , and the first nozzle 233 a . At this time, inert gas may be simultaneously supplied to the inside of the first gas supply pipe 232 a . In addition, ammonia (NH 3 ) gas may be supplied from the second gas supply pipe 232 b to the inside of the process chamber 201 through the second MFC 241 b , the second valve 243 b , and the second nozzle 233 b . At this time, inert gas may be simultaneously supplied to the inside of the second nozzle 233 b.
In addition, at the lower side of the process chamber 201 , a short pipe 301 is installed as a third gas introducing part. A first cleaning gas supply pipe 300 which is a cleaning gas supply passage is connected to the short pipe 301 . Cleaning gas is used for removing substances attached to the inside of the process chamber 201 . At the first cleaning gas supply pipe 300 , a flowrate controller (flowrate control unit) such as a third MFC 302 , and an on-off valve such as a third valve 304 are installed. Cleaning gas is introduced into the first cleaning gas supply pipe 300 for supplying the cleaning gas to the process chamber 201 .
A second cleaning gas supply pipe 350 , which is a cleaning gas supply passage separate from the first cleaning gas supply pipe 300 , is connected to the first gas supply pipe 232 a . At the second cleaning gas supply pipe 350 , a flowrate controller (flowrate control unit) such as a fourth MFC 352 , and an on-off valve such as a fourth valve 354 are installed. Cleaning gas is introduced into the second cleaning gas supply pipe 350 for supplying the cleaning gas to the process chamber 201 through the first gas supply pipe 232 a.
In addition, a gas exhaust pipe 231 is installed to exhaust the inside atmosphere of the process chamber 201 . A vacuum exhaust device such a vacuum pump 246 is connected to the downstream side of the gas exhaust pipe 231 opposite to the process tube 203 through a pressure detector such as a pressure sensor 245 and a pressure regulator such as an auto pressure controller (APC) valve 242 . The APC valve 242 is an on-off valve, which can be opened and closed to start and stop vacuum evacuation of the inside of the process chamber 201 and can be adjusted in opened degree for pressure adjustment. While operating the pressure sensor 245 , by controlling the opened degree of the APC valve 242 based on pressure information detected by the pressure sensor 245 , the inside of the process chamber 201 can be vacuum-evacuated to a desired pressure (vacuum degree).
A seal cap 219 is installed as a furnace port cover capable of hermetically closing the opened bottom side of the process tube 203 . For example, the seal cap 219 is made of a metal such as stainless steel and has a disk shape. On the top surface of the seal cap 219 , an O-ring 220 is installed as a seal member. At a side of the seal cap 219 opposite to the process chamber 201 , a rotary mechanism 267 is installed to rotate a boat 217 (described later) which is a substrate holder. A rotation shaft (not shown) of the rotary mechanism 267 is connected to the boat 217 through the seal cap 219 . The rotary mechanism 267 is configured to rotate wafers 200 by rotating the boat 217 . The seal cap 219 is configured to be vertically moved by an elevating mechanism such as a boat elevator (not shown) which is vertically installed outside the process tube 203 . The boat elevator is configured to move the seal cap 219 vertically for loading/unloading the boat 217 to/from the process chamber 201 .
The boat 217 is made of a heat-resistant material such as quartz or silicon carbide and is configured to support a plurality of wafers 200 in a state where the wafers 200 are horizontally oriented and arranged in multiple stages with the centers of the wafers 200 being aligned with each other. In addition, at the lower part of the boat 217 , an insulating member 218 made of a heat-resistant material such as quartz or silicon carbide is installed so as to prevent heat transfer from the heater 207 to the seal cap 219 . The insulating member 218 may include a plurality of insulating plates made of a heat-resistant material such as quartz or silicon carbide, and an insulating plate holder configured to support the insulating plates in a state where the insulating plates are horizontally oriented and arranged in multiple stages. Inside the process tube 203 , a temperature sensor 263 is installed as a temperature detector, and by controlling power supplied to the heater 207 based on temperature information detected by the temperature sensor 263 , desired temperature distribution can be attained at the inside of the process chamber 201 . Like the first nozzle 233 a and the second nozzle 233 b , the temperature sensor 263 is installed along the inner wall of the process tube 203 .
A controller 280 which is a control unit (control device) is connected to the first to fourth MFC 241 a , 241 b , 302 , and 352 , the first to fourth valves 243 a , 243 b , 304 , and 305 , the pressure sensor 245 , the APC valve 242 , the heater 207 , the temperature sensor 263 , the vacuum pump 246 , the rotary mechanism 267 , and so on.
The controller 280 is used to control, for example, flowrates of the first to fourth MFC 241 a , 241 b , 302 , and 352 ; opening/closing operations of the first to fourth valves 243 a , 243 b , 304 , and 305 ; opening/closing operations of the APC valve 242 and pressure adjusting operations of the APC valve 242 based on the pressure sensor 245 ; the temperature of the heater 207 based on the temperature sensor 263 ; starting/stopping operations of the vacuum pump 246 ; and the rotation speed of the rotary mechanism 267 .
(2) Method of Forming Silicon Nitride Film
Next, as an example of a film-forming method for a semiconductor device manufacturing process using the above-described substrate processing apparatus, an exemplary method of forming a silicon nitride (SiN) film containing stoichiometrically excessive silicon (Si) with respect to nitrogen (N) (i.e., a silicon-rich silicon nitride film) by using dichlorosilane (DCS) and ammonia (NH 3 ) will now be described according to an embodiment. In addition, the present invention can be applied to any kind of film without being limited to a silicon-rich silicon nitride film so long as the film is formed by using two or more kinds of gases.
In the following description, components of the substrate processing apparatus are controlled by the controller 280 .
In the current embodiment, a film is formed by using a method similar to but not identical to an atomic layer deposition (ALD) method. In an ALD method, process gases which provide at least two source materials for forming a film are supplied to a substrate in turns under predetermined film forming conditions (temperature, time, etc.), so as to allow the process gases to be adsorbed on the substrate on an atomic layer basis for forming a film by surface reaction. At this time, the thickness of the film can be controlled by adjusting the number of process gas supply cycles (for example, if the film forming rate is 1 Å/cycle and it is intended to form a 20-Å film, the process is repeated 20 cycles).
That is, in the film-forming method of the current embodiment, a process of supplying DCS to a wafer 200 under conditions where chemical vapor deposition (CVD) reaction is caused, and a process of supplying NH 3 to the wafer 200 under a non-plasma condition and other predetermined conditions are repeated in turns so as to form a silicon-rich silicon nitride (SiN) film. In the current embodiment, a process (Step 1 ) of supplying DCS to a wafer 200 , a process (Step 2 ) of removing the DCS from the wafer 200 , a process (Step 3 ) of supplying NH 3 to the wafer 200 , and a process (Step 4 ) of removing the NH 3 from the wafer 200 are set to one cycle, and the cycle is repeated a plurality of times to form a silicon-rich silicon nitride (SiN) film. In the process (Step 1 ) of supplying DCS to a wafer 200 , a silicon film having several or less atomic layers (1/n to several atomic layers) is formed on the wafer 200 . At this time, an excessive amount of silicon (Si) is supplied. Furthermore, in the process (Step 3 ) of supplying NH 3 to the wafer 200 , the silicon film having several or less atomic layers and formed on the wafer 200 is thermally nitrided. At this time, the silicon film is nitrided by NH 3 in a non-saturated condition. That is, the silicon film is not completely nitrided, and thus Si—N bonds are not fully made. In this way, nitriding of silicon (Si) is suppressed, and thus silicon (Si) becomes surplus. At this time, to obtain a condition where nitriding of the silicon film is not saturated, it is preferable that at least one of the supply flowrate of NH 3 , the supply time of NH 3 , and the inside pressure of the process chamber 201 be adjusted to be different from a condition where the nitriding of the silicon film is saturated. That is, as compared with a condition where nitriding of the silicon film is saturated, the supply flowrate of NH 3 is reduced, the supply time of NH 3 is shortened, or the inside pressure of the process chamber 201 is reduced. For example, a small amount of NH 3 is supplied as compared with the amount of NH 3 necessary for forming a silicon nitride (Si 3 N 4 ) film having a stoichiometric composition. As described above, the supply flowrate of silicon (Si) is controlled in the process of forming a silicon film having several or less atomic layers on a wafer 200 by using a CVD method, and the nitriding degree of silicon (Si) is controlled in the process of thermally nitriding the silicon film with NH 3 . The processes are alternately repeated to form a silicon-rich silicon nitride (SiN) film while controlling the Si/N composition ratio of the silicon nitride (SiN).
Hereinafter, the film-forming method of the current embodiment will be described in detail with reference to FIG. 3 .
After a plurality of wafers 200 are charged into the boat 217 (wafer charging), as shown in FIG. 1 , the boat 217 in which the plurality of wafers 200 are charged is lifted and loaded into the process chamber 201 by the boat elevator (not shown) (boat loading). In this state, the bottom side of the process tube 203 is sealed by the seal cap 219 with the O-ring 220 b being disposed therebetween.
The inside of the process chamber 201 is vacuum-evacuated to a desired pressure (vacuum degree) by using the vacuum pump 246 . At this time, the pressure inside the process chamber 201 is measured by the pressure sensor 245 , and based on the measured pressure, the APC valve 242 is feedback-controlled (pressure adjustment). In addition, the inside of the process chamber 201 is heated to a desired temperature by using the heater 207 . At this time, to obtain desired temperature distribution inside the process chamber 201 , power to the heater 207 is feedback-controlled based on temperature information measured by the temperature sensor 263 (temperature adjustment). Next, the boat 217 is rotated by the rotary mechanism 267 to rotate the wafers 200 . Thereafter, the following four steps are sequentially performed.
(Step 1 )
The first valve 243 a of the first gas supply pipe 232 a is opened to allow DCS to flow through the first gas supply pipe 232 a . At this time, inert gas may be allowed to flow through the first gas supply pipe 232 a . The flowrate of DCS flowing through the first gas supply pipe 232 a is controlled by the first MFC 241 a , and the DCS is mixed with flowrate-controlled inert gas. Then, the mixture is supplied to the inside of the process chamber 201 through the first gas supply holes 248 a of the first nozzle 233 a and is discharged through the gas exhaust pipe 231 . At this time, the APC valve 242 is properly controlled to keep the inside of the process chamber 201 at a pressure of 133 Pa to 1333 Pa, for example, 133 Pa. The first MFC 241 a is used to adjust the flowrate of DCS in the range from 0.1 slm to 10 slm, for example, 0.5 slm. The wafers 200 are exposed to DCS, for example, for 1 second to 180 seconds. At this time, the heater 207 is controlled to allow thermal decomposition of DCS for inducing CVD reaction. That is, the heater 207 is controlled to heat the wafers 200 to a temperature of 550° C. to 700° C., for example, 630° C. By supplying DCS to the inside of the process chamber 201 under the above-described conditions, silicon (Si) films each including several or less atomic layers (that is, 1/n atomic layer to several atomic layers) are formed on the wafers 200 (deposition of CVD-Si film). For example, silicon films each including a half atomic layer (half layer) or a mono atomic layer (mono layer) may be formed. In this way, silicon (Si) is excessively supplied.
(Step 2 )
After the silicon films each including several or less atomic layers are formed, the first valve 243 a of the first gas supply pipe 232 a is closed so as to interrupt supply of DCS. At this time, in a state where the APC valve 242 of the gas exhaust pipe 231 is opened, the inside of the process chamber 201 is vacuum-exhausted to 10 Pa or less by using the vacuum pump 246 to remove remaining DCS from the inside of the process chamber 201 . Along with this, if inert gas such as N 2 is supplied to the inside of the process chamber 201 , the remaining DCS may be removed more efficiently (remaining gas removal).
(Step 3 )
The second valve 243 b of the second gas supply pipe 232 b is opened to allow NH 3 to flow through the second gas supply pipe 232 b . At this time, inert gas may be allowed to flow through the second gas supply pipe 232 b . The flowrate of NH 3 flowing through the second gas supply pipe 232 b is controlled by the second MFC 241 b , and the NH 3 is mixed with flowrate-controlled inert gas. Then, the mixture is supplied to the inside of the process chamber 201 through the second gas supply holes 248 b of the second nozzle 233 b and is discharged through the gas exhaust pipe 231 . As described above, NH 3 is supplied to the inside of the process chamber 201 in a state where the NH 3 is not activated by plasma.
In Step 3 , the inside conditions of the process chamber 201 are adjusted so that the silicon films are nitrided under conditions where the nitriding reaction of the silicon film by the NH 3 is not saturated. That is, the supply amount of NH 3 is adjusted to be less than an amount necessary for nitriding the silicon films to form silicon nitride (Si 3 N 4 ) films each having a stoichiometric composition. In addition, at this time, the APC valve 242 is properly adjusted to keep the inside of the process chamber 201 at a pressure of 133 Pa to 1333 Pa, for example, 865 Pa. The second MFC 241 b is controlled to supply NH 3 at a flowrate of 0.1 slm to 10 slm, for example, 1 slm. The wafers 200 are exposed to NH 3 for 1 second to 180 seconds. At this time, the heater 207 is controlled so as to keep the wafers 200 in the same temperature range of 550° C. to 700° C., for example, 630° C., like the case of supplying DCS in Step 1 . In this way, NH 3 is supplied to the inside of the process chamber 201 in a non-plasma condition, so as to thermally nitride the silicon films each including several or less atomic layers and formed on the wafers 200 (thermal nitriding of CVD-Si film). At this time, since silicon is excessive due to the restrained nitriding of silicon (Si), silicon-rich silicon nitride films can be formed.
If it is assumed that all DCS and NH 3 supplied to the inside of the process chamber 201 are used to form a silicon nitride film, a silicon nitride (Si 3 N 4 ) film having a stoichiometric composition can be formed on a wafer 200 by supplying DCS which is a silicon-containing substance and NH 3 which is a nitrogen-containing substance to the inside of the process chamber 201 at a ratio of 3:4. In the current embodiment, however, the supply amount of NH 3 is less than the amount necessary for thermally nitriding a silicon film to form a silicon nitride (Si 3 N 4 ) film having a stoichiometric composition. That is, the supply amount of NH 3 is restricted so as not to saturate nitriding reaction of the silicon film. In this way, the amount of nitrogen is adjusted to be insufficient for forming a silicon nitride (Si 3 N 4 ) film having a stoichiometric composition, so that a silicon-rich silicon nitride film can be formed on the wafer 200 .
Practically, the composition ratio of silicon/nitrogen of a silicon nitride film is varied not only by the supply amount of NH 3 , but also by other conditions in Step 3 , such as difference of reactiveness caused by the inside pressure of the process chamber 201 , difference of reactiveness caused by the temperature of a wafer 200 , the supply flowrate of NH 3 , and the supply time of NH 3 (that is, reaction time). In addition, the composition ratio of silicon and nitrogen of a silicon nitride film is also varied by conditions in Step 1 , such as the pressure inside the process chamber 201 , the temperature of a wafer 200 , the supply flowrate of DCS, and the supply time of DCS. That is, controlling of the balance between the supply of silicon (Si) in Step 1 and the supply of nitrogen (N) in Step 3 is important for controlling the composition ratio of silicon and nitrogen (Si/N ratio) of a silicon nitride film. In the current embodiment, the pressure inside the process chamber 201 , the temperature of a wafer 200 , the supply flowrate of gas, and the supply time of gas are properly controlled within the above-described mentioned ranges, so as to control the composition ratio of silicon/nitrogen of a silicon nitride film. If the amount of silicon (Si) supplied in Step 1 is concerned as a reference (is fixed to a predetermined value), the Si/N ratio is most dependent on the supply flowrate of NH 3 , the supply time of NH 3 , and the pressure inside the process chamber 201 among conditions in Step 3 . Therefore, in Step 3 , it is preferable that at least one of the supply flowrate of NH 3 , the supply time of NH 3 , and the pressure inside the process chamber 201 be different from conditions where the nitriding reaction of a silicon film is saturated. Specifically, the supply flowrate of NH 3 , the supply time of NH 3 , or the pressure inside the process chamber 201 may be reduced as compared with a condition where the nitriding reaction of a silicon film is saturated.
(Step 4 )
After the silicon films each including several or less atomic layers are thermally nitrided, the second valve 243 b of the second gas supply pipe 232 b is closed to interrupt supply of NH 3 . At this time, in a state where the APC valve 242 of the gas exhaust pipe 231 is opened, the inside of the process chamber 201 is exhausted to a pressure of 10 Pa or less to remove remaining NH 3 from the inside of the process chamber 201 . Along with this, if inert gas such as N 2 is supplied to the inside of the process chamber 201 , remaining NH 3 can be removed more efficiently (remaining gas removal).
By setting the above-mentioned Steps 1 to 4 to one cycle, and repeating this cycle a plurality of times, silicon-rich silicon nitride films can be formed on the wafers 200 to a predetermined thickness.
After silicon-rich silicon nitride films are formed to a predetermined thickness, the inside of the process chamber 201 is purged by supplying inert gas such as N 2 to the inside of the process chamber 201 and exhausting the inert gas from the inside of the process chamber 201 (purge). By this, the inside atmosphere of the process chamber 201 is replaced with inert gas, and the inside pressure of the process chamber 201 is returned to atmospheric pressure (returning to atmospheric pressure).
Thereafter, the seal cap 219 is moved downward by the boat elevator (not shown) so as to open the bottom side of the process tube 203 and unload the processed wafers 200 from the inside of the process tube 203 through the bottom side of the process tube 203 in a state where the processed wafers 200 are held in the boat 217 (boat unloading). Then, the processed wafers 200 are discharged from the boat 217 (wafer discharging).
Although DCS is used as a silicon source in the above description, the present invention is not limited thereto. For example, another substance such as trichlorosilane (SiHCl 3 , abbreviation: TCS), hexachlorosilane (Si 2 Cl 6 , abbreviation: HCD), monosilane (SiH 4 ), and disilane (Si 2 H 6 ) may be used.
(3) Cleaning Method
After a process of forming a silicon-rich silicon nitride is performed predetermined times, a cleaning process is performed on the process chamber 201 by using a cleaning gas. In the current embodiment, for example, chlorine trifluoride (ClF 3 ) is used as a cleaning gas.
The first nozzle 233 a and the inside of the process tube 203 (for example, the inner wall of the process tube 203 , the outer walls of the first nozzle 233 a and the second nozzle 233 b , and the boat 217 ) are cleaned under conditions optimal for the respective parts.
<Method of Cleaning Inner Wall of First Nozzle>
First, cleaning of the inner wall of the first nozzle 233 a will be explained ( FIG. 4 ). Cleaning of the inner wall of the first nozzle 233 a is performed under a pressure lower than a pressure at which the inside of the process tube 203 is cleaned.
(Step 11 )
In Step 11 , first, the APC valve 242 is opened to exhaust the inside of the process chamber 201 . At this time, the fourth valve 354 and the first valve 243 a are closed.
(Step 12 )
If the inside of the process chamber 201 is sufficiently exhausted, the fourth valve 354 is opened to supply ClF 3 gas to the first nozzle 233 a while controlling the flowrate of the ClF 3 gas by using the fourth MFC 352 (Step 12 ). At this time, the flowrate of the ClF 3 gas is set to from 0.1 slm to 0.4 slm, for example, 0.1 slm. In addition, inert gas such as N 2 gas is simultaneously supplied, for example, at a flowrate of 0.4 slm, and the ClF 3 concentration of the inside of the first nozzle 233 a is set to from 20% to 50%, for example, 20%. In the case where the ClF 3 concentration of the inside of the first nozzle 233 a is kept higher than 20%, the flowrate of N 2 gas simultaneously supplied through a part such as the second nozzle 233 b is increased so as to keep the concentration of ClF 3 equal to or lower than 20% when the ClF 3 is exhausted from the inside of the process chamber 201 .
Furthermore, in a state where the APC valve 242 is opened, the controller 280 adjusts pressure to a predetermined level. Preferably, the pressure is adjusted to a constant level between 10 Pa to 400 Pa, for example, 66.7 Pa (0.5 Torr). By this, a silicon film (unnecessary silicon film to be removed), which is accumulated on the inner wall of the first nozzle 233 a during the above-described film-forming process, is brought into reaction with supplied ClF 3 gas.
(Step 13 )
After ClF 3 gas is supplied to the first nozzle 233 a for a predetermined time, the first valve 243 a is closed, and the inside of the process chamber 201 is exhausted (Step 13 ). In addition, while ClF 3 is supplied through the first nozzle 233 a , inert gas such as N 2 gas may be supplied to the inside of the process chamber 201 through the second nozzle 233 b and the short pipe 301 . By supplying inert gas such as N 2 gas, reverse flows of ClF 3 gas from the inside of the process chamber 201 to the second nozzle 233 b and the short pipe 301 can be prevented.
<Method of Cleaning Inside of Process Tube>
Next, a method of cleaning the inside of the process tube 203 will be explained. The following two steps are mainly performed ( FIG. 5 ).
(Step 21 )
In Step 21 , the process chamber 201 is filled with ClF 3 gas. First, the temperature of the heater 207 is set to from 400° C. to 420° C., for example, 400° C. Then, in a state where the inside of the process chamber 201 is exhausted by opening the APC valve 242 (the fourth valve 354 is closed), the third valve 304 is opened to supply ClF 3 to the first cleaning gas supply pipe 300 and fully fill the inside of the process chamber 201 with the ClF 3 . For example, the flowrate of ClF 3 supplied through the short pipe 301 is set to 0.5 slm. Since parts such as an exhaust pipe may be corroded if the concentration of ClF 3 is high, the concentration of ClF 3 is set to, for example, 20%. To control the inside pressure of the process chamber 201 , the APC valve 242 is opened, and the inside pressure of the process chamber 201 is adjusted to a predetermined level. Preferably, the inside pressure of the process chamber 201 is adjusted to a constant level between 400 Pa to 1000 Pa, for example, 931 Pa (7 Torr).
By supplying ClF 3 to the inside of the process chamber 201 through the short pipe 301 as described above, the inside of the process chamber 201 can be cleaned without involving the first nozzle 233 a.
In addition, inert gas such as N 2 gas may be supplied through the first nozzle 233 a and the second nozzle 233 b . By supplying N 2 gas, reverse flows of ClF 3 gas from the inside of the process chamber 201 to the first nozzle 233 a and the second nozzle 233 b can be prevented. The flowrate of N 2 gas supplied through the first nozzle 233 a and the second nozzle 233 b may be 0.8 slm, for example. Furthermore, inert gas such as N 2 gas may be supplied through the rotation shaft (not shown) of the rotary mechanism 267 , for example, at a flowrate of 0.3 slm.
Then, if a predetermined time (for example, 85 seconds) elapses after the third valve 304 is opened, Step 22 is performed.
(Step 22 )
In Step 22 , gas filled in the process chamber 201 is exhausted. A silicon nitride film (unnecessary silicon nitride film to be removed) accumulated in the process chamber 201 during the film-forming process is brought into reaction with ClF 3 supplied in Step 21 , and ClF 3 gas (including ClF 3 gas not participated in reaction) and N 2 gas are mainly filled in the process chamber 201 . Therefore, such gases are exhausted from the process chamber 201 .
In detail, the APC valve 242 is opened so as to exhaust gas filled in the process chamber 201 at a time through the gas exhaust pipe 231 .
Then, if a predetermined time (for example, 10 seconds) after the APC valve 242 is opened, Step 22 is stopped. Thereafter, Step 21 and Step 22 are set as a cycle, and the cycle is repeated predetermined times. In this way, cleaning of the inside of the process tube 203 is completed.
Furthermore, in Step 22 , at the same time with vacuum evacuation, N 2 purge may be performed by supplying inert gas such as N 2 through the first nozzle 233 a , the second nozzle 233 b , and the short pipe 301 ; or in Step 22 , vacuum evacuation and N 2 purge may be alternately repeated predetermined times.
By repeating Step 21 and Step 22 (one cycle) predetermined times, the inside of the process tube 203 is cleaned. As described above, exhaustion of gas that does not contribute to cleaning, and supply of new ClF 3 gas are repeated, so that cleaning gas can be effectively reacted with a silicon nitride accumulated in the inside of the process tube 203 .
Either the cleaning of the inner wall of the first nozzle 233 a or the cleaning of the inside of the process tube 203 may first be performed, and then the other may be performed; however, it is preferable that the cleaning of the inner wall of the first nozzle 233 a be first performed. In the case where the cleaning of the inner wall of the first nozzle 233 a is first performed, ClF 3 gas that passes through the first nozzle 233 a with reaction is supplied to the inside of the process tube 203 , and the ClF 3 gas reacts with a silicon nitride film accumulated in the inside (inner wall, etc.) of the process tube 203 , so that the silicon nitride film can be removed. Therefore, if the cleaning of the inside of the process tube 203 is performed after the cleaning of the inner wall of the first nozzle 233 a , time necessary for cleaning the inside of the process tube 203 can be reduced. That is, by cleaning the inner wall of the first nozzle 233 a first, a high etching rate can be obtained, and thus throughput can be improved.
In addition, since a silicon nitride film is attached to almost all the region of the inside of the process tube 203 , the cleaning cycle may be determined according to the thickness of the silicon nitride film accumulated in the process tube 203 (corresponding to the amount of deposition on a wafer), and the cleaning cycle may be performed each time after the film-forming process is repeated a predetermined number of times. Therefore, cleaning conditions of the inside of the process tube 203 such as the inside pressure of the process tube 203 or the supply flowrate of cleaning gas may be determined according to the actual amount of deposition. The amount of deposition on wafers can be calculated by monitoring the supply flowrate of NH 3 .
Meanwhile, the thickness of a silicon film accumulated on the inner wall of the first nozzle 233 a is varied according to film-forming conditions such as substrate temperature, DCS supply time, and DCS supply amount. Therefore, cleaning conditions of the inner wall of the first nozzle 233 a such as the inside pressure of the first nozzle 233 a and the supply flowrate of cleaning gas are determined according to film-forming conditions such as DCS supply time and DCS supply flowrate. The cleaning cycle of the inside of the first nozzle 233 a is determined according to film-forming conditions such as DCS supply time and DCS supply flowrate. In addition, when DCS is supplied as a process gas, the thickness of a silicon film accumulated on the inner wall of the first nozzle 233 a may be proportional to the supply amount of silicon molecules.
As described above, for removing the thickness of a film by a desired amount, that is, for removing the accumulated thickness of a film by a desired amount, cleaning conditions of the inside of the process tube 203 are adjusted according to the number of cycles of the silicon nitride film forming process, and cleaning conditions of the inner wall of the first nozzle 233 a are adjusted according to film-forming conditions such as DCS supply time and DCS supply flowrate.
In addition, preferably, the cleaning conditions and cleaning timing of the insides of the first nozzle 233 a and the process tube 203 may be determined and controlled by control units 500 a and 500 b as shown in FIG. 7A and FIG. 7B .
FIG. 7A illustrates the control unit 500 a configured to control cleaning conditions and timing of the first nozzle 233 a by monitoring film-forming conditions when DCS is supplied. That is, each time a film-forming process is performed, the supply amount of DCS is monitored by a monitoring unit 510 a which is configured to monitor the first MFC 241 a which is a flowrate controller (flowrate control unit) or to monitor a process recipe (film-forming process conditions), and the monitored supply amount of DCS is added by a counter such as an adding unit 520 a . The added DCS supply amount (the accumulated amount of DCS) is stored in a memory device such as a memory unit 530 a . The accumulated amount of DCS is compared with a predetermined threshold value by a comparison unit 540 a . The threshold value is preset at the comparison unit 540 a.
If the accumulated amount of DCS reaches the threshold value, the comparison unit 540 a informs a signal output unit 550 a of the event, and then the signal output unit 550 a sends at least one of a cleaning condition setting signal and a cleaning start signal to the controller 280 .
Similarly, FIG. 7B illustrates the control unit 500 b configured to control cleaning conditions and timing of the second nozzle 233 b by monitoring film-forming conditions when NH 3 is supplied through the second nozzle 233 b . That is, each time a film-forming process is performed, the supply amount of NH 3 is monitored by a monitoring unit 510 b which is configured to monitor the second MFC 241 b which is a flowrate controller (flowrate control unit) or to monitor a process recipe (film-forming process conditions), and the monitored supply amount of NH 3 is added by a counter such as an adding unit 520 b . The added NH 3 supply amount (the accumulated amount of NH 3 ) is stored in a memory device such as a memory unit 530 b . The accumulated amount of NH 3 is compared with a predetermined threshold value by a comparison unit 540 b . The threshold value is preset at the comparison unit 540 b.
If the accumulated amount of NH 3 reaches the threshold value, the comparison unit 540 b informs a signal output unit 550 b of the event, and then the signal output unit 550 b sends at least one of a cleaning condition setting signal and a cleaning start signal to the controller 280 .
In addition, after considering things related to cleaning quality, such as whether a desired film is uniformly removed (without over-etching of quartz), whether corrosion occurs, whether contaminants generate, and whether remaining gas affects a film-forming process, cleaning conditions are timing are determined to increase the etching rate (that is, throughput).
Furthermore, when the inside of the process tube 203 is cleaned, inert gas is continuously supplied to the first nozzle 233 a and the second nozzle 233 b.
Furthermore, cleaning of the inside of the process tube 203 may be overlapped with cleaning of the inner wall of the first nozzle 233 a at least partially. In this case, if the cleaning of the inner wall of the first nozzle 233 a is performed at the same pressure as a pressure at which the cleaning of the inside of the process tube 203 is performed, the first nozzle 233 a may be damaged and broken. On other hand, if the cleaning of the inside of the process tube 203 is performed at the same pressure as a pressure at which the cleaning of the inner wall of the first nozzle 233 a is performed, the cleaning time may be increased because the pressure is too low. For this reason, although the cleaning of the inner wall of the first nozzle 233 a is performed at the same pressure as a pressure at which the cleaning of the inside of the process tube 203 is performed, a low-concentration cleaning gas is supplied to the inner wall of the first nozzle 233 a . Since a cleaning gas is supplied only through the short pipe 301 during a cleaning process of the inside of the process tube 203 and a cleaning gas is supplied only to the first nozzle 233 a during a cleaning process of the inner wall of the first nozzle 233 a , flowrate tuning is necessary for performing the two cleaning processes at the same time.
In addition, if the amount of silicon attached to the inner wall of the first nozzle 233 a is large, since it is difficult to remove the silicon from the first nozzle 233 a , the pressure of a cleaning process is increased. However, if the pressure is increased too much, although the cleaning process can be completed more rapidly owing to an increased etching rate, the first nozzle 233 a may be devitrified due to generation of heat. If the first nozzle 233 a is damaged in this way, it may be necessary to replace the first nozzle 233 a . In addition, since the inside of the first nozzle 233 a is narrow and long, by rapidly making the inside pressure of the first nozzle 233 a uniform, the rate of etching can be made uniform in the vertical direction.
According to the current embodiment, one or more of the following effects can be attained.
The inside of the process tube 203 , where a silicon nitride is accumulated, and the inner wall of the first nozzle 233 a , where a silicon source such as DCS is supplied and a silicon film is accumulated, are cleaned under conditions optimized for the respective parts, so that cleaning can be efficiently performed with less contamination, damage of the process tube 203 , and damage of the first nozzle 233 a.
That is, cleaning can be thoroughly performed with less cleaning time and good gas consumption efficiency without a remaining film.
In addition, generation of contamination caused by excessive etching conditions can reduced; operational costs can be reduced because the process tube 203 and the first nozzle 233 a can be less damaged; and maintenance time can be reduced.
When a silicon nitride film attached to the inside of the process tube 203 is cleaned, by filling a high-concentration cleaning gas in the entire inside of the process tube 203 and increasing the inside pressure of the process tube 203 , particularly, the upper part of the process chamber 201 can be less affected by gas flow distribution, and the cleaning process can be completed within a shorter time.
When a silicon nitride film attached to the inside of the process tube 203 is cleaned, by alternately repeating supply of a cleaning gas and exhaustion of the cleaning gas (cyclic supply), stagnant gas can be exhausted by distribution of gas flows and thus be replaced with a cleaning gas. That is, exhaustion of gas that has reacted with a silicon nitride film accumulated on the inside of the process tube 203 (that is, exhaustion of gas that does not contribute to cleaning anymore), and introduction of a new cleaning gas are repeated, so that cleaning can be effectively performed with a shorter time and less consumption of cleaning gas.
When cleaning a silicon film attached to the inner wall of the first nozzle 233 a which is used to supply a silicon source such as DCS, pressure is kept lower than a pressure at which the inside of the process tube 203 is cleaned, so as to weaken cleaning reaction power for preventing damage of a quartz part. In addition, if reaction power is high, heat generation may increase to cause breakage of a quartz part, and if reaction speed is high, a silicon film may decompose destructively to cause contamination. That is, these disadvantages can be prevented.
When cleaning a silicon film attached to the inner wall of the first nozzle 233 a which is used to supply a silicon source such as DCS, supply and exhaustion of a cleaning gas are continuously performed instead of alternately repeating them, so that gas participated in reaction and not participated in reaction can be efficiently discharged and the cleaning process can be rapidly completed.
(4) Another Embodiment
According to another embodiment, a method of cleaning the process tube 203 will now be described with reference to FIG. 6 and FIG. 8 . The same elements as those shown in FIG. 1 will be denoted by the same reference numerals, and descriptions thereof will not be repeated.
At a first cleaning gas supply pipe 300 , a gas reservoir 306 and an on-off valve such as a fifth valve 308 are installed as well as a flowrate control device such as a third MFC 302 and an on-off valve such as a third valve 304 , and the fifth valve 308 is configured to be controlled by a controller 280 .
(Step 31 )
First, ClF 3 gas is filled in a process chamber 201 as follows: in a state where the inside of the process chamber 201 is exhausted by opening an APC valve 242 (a fourth valve 354 is closed), the third valve 304 is opened and the fifth valve 308 is closed so as to introduce ClF 3 gas into the first cleaning gas supply pipe 300 and store the ClF 3 gas in the gas reservoir 306 while controlling the flowrate of the ClF 3 using the third MFC 302 (Step 31 ).
(Step 32 )
If a predetermined amount of ClF 3 gas is stored in the gas reservoir 306 , the third valve 304 is closed to stop an inflow of ClF 3 gas into the gas reservoir 306 . In this state, the ClF 3 gas stored in the gas reservoir 306 is supplied to the process chamber 201 at a time (a flash flow) by opening the fifth valve 308 so as to fill the inside of the process chamber 201 with the ClF 3 gas. In addition, the APC valve 242 is opened to control the inside pressure of the process chamber 201 to a predetermined level (Step 32 ).
(Step 33 )
Like the case where the gas reservoir 306 is not used, gas filled in the process chamber 201 is exhausted (Step 33 ). After a predetermined time from the opening of the APC valve 242 , the process of Step 33 is completed.
After that, Step 31 , Step 32 , and Step 33 are set as one cycle, and this cycle is repeated predetermined times. In this way, cleaning of the inside of the process tube 203 is completed.
While the process of Step 32 is performed, Step 31 may be concurrently performed to store ClF 3 gas in the gas reservoir 306 (that is, the third valve 304 is opened and the fifth valve 308 is closed to store ClF 3 gas in the gas reservoir 306 ). In this case, the process time of the entire cleaning process can be reduced.
Furthermore, without Step 31 for storing ClF 3 gas in the gas reservoir 306 , ClF 3 gas may be supplied to the inside of the process chamber 201 and filled in the inside of the process chamber 201 only by manipulating each valve.
As described above, when a silicon nitride film attached to the inside of the process tube 203 is cleaned, a cleaning gas is instantaneously supplied to the inside of the process tube 203 to increase the gas concentration of the inside of the process tube 203 and fill the cleaning gas in the entire inside of the process tube 203 . By increasing pressure in this way, particularly, the effect of gas flow distribution in the upper region of the process chamber 201 can be reduced, and cleaning can be performed within a shorter time.
In addition, since the temperature of the lower side of the process tube 203 is lower than temperature of the upper side of the process tube 203 , it is more difficult to remove a silicon nitride film attached to the lower side of the process tube 203 . Therefore, a cleaning process may be divided into a process of cleaning the entire inside of the process tube 203 and a process of cleaning the lower side of the process tube 203 , and the process of cleaning the entire inside of the process tube 203 may be performed at a high pressure (high-pressure cycle) but the process of cleaning the lower side of the process tube 203 may be performed at a relatively low pressure (low-pressure cycle). In the case of the low-pressure process, it is preferable that a cleaning gas be continuously supplied instead of supplying the cleaning gas instantaneously. In this way, the cleaning process of the inside of the process tube 203 may be performed in two cleaning steps: a high-pressure intermittent cleaning step and a low-pressure continuous cleaning step. Alternatively, in a way of varying pressure when a cleaning gas is supplied, silicon nitride films attached to the upper and lower sides of the process tube 203 may be preferentially removed.
In the above described description, a silicon-rich silicon nitride film is described as a film to be formed on a substrate; however, the present invention is not limited thereto. For example, the present invention can be applied to apparatuses configured to form films such as a silicon nitride film having a stoichiometric composition ratio, an aluminum nitride film, a titanium nitride film, a hafnium nitride film, a zirconium nitride film, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, a titanium oxide film, a hafnium oxide film, a zirconium oxide film, and a silicon oxide film. That is, the present invention can be applied to an apparatus in which different kinds of films are formed on the inside of a process tube and the inner wall of a gas supply nozzle (i.e., an apparatus including gas supply nozzles for respective process gases).
In addition, besides a silicon (Si)-containing gas, a metal element-containing gas such as an aluminum (AD-containing gas, a titanium (Ti)-containing gas, a hafnium (Hf)-containing gas, and a zirconium (Zr)-containing gas may be used as a process gas capable of depositing a film by itself at a certain temperature, and besides a nitrogen (N)-containing gas, gas such as an oxygen (O)-containing gas may be used as a process gas incapable of depositing a film by itself at a certain temperature.
Furthermore, although chlorine trifluoride (ClF 3 ) is described as an example of a cleaning gas, the present invention is not limited thereto. For example, gas including at least one gas selected from the group consisting of nitrogen trifluoride (NF 3 ) gas, fluorine (F 2 ) gas, hydrogen fluoride (HF) gas, chlorine (Cl 2 ) gas, and boron trichloride (BCl 3 ) gas may be used as a cleaning gas.
According to the method of manufacturing a semiconductor device, the cleaning method, and the substrate processing apparatus of the present invention, the reaction tube and the gas supply nozzle can be cleaned under conditions optimized according to the film-forming conditions of the reaction tube and the gas supply nozzle, thereby making it possible to perform a cleaning process with less contamination and damages on the reaction tube and the gas supply nozzle.
<Supplementary Note>
The present invention also includes the following preferred embodiments.
(Supplementary Note 1)
According to an embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, the method comprising: loading a substrate into a process chamber; forming a film on the substrate by supplying a first process gas, which comprises at least one of a plurality of elements constituting the film and is capable of depositing a film by itself, to an inside of the process chamber through a first gas introducing part, and supplying a second process gas, which comprises at least one of the others of the plurality of elements constituting the film and is incapable of depositing a film by itself, to the inside of the process chamber through a second gas introducing part; unloading the substrate from the process chamber after the film is formed on the substrate; performing a first cleaning process so as to remove a first deposition substance attached to an inner wall of the first gas introducing part by supplying a cleaning gas to the first gas introducing part; and performing a second cleaning process so as to remove a second deposition substance attached to the inside of the process chamber and having a chemical composition different from that of the first deposition substance by supplying a cleaning gas to the inside of the process chamber through a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed, wherein in the performing of the first cleaning process, cleaning conditions are set according to accumulated supply time of the first process gas supplied to the inside of the process chamber through the first gas introducing part, and in the performing of the second cleaning process, cleaning conditions are set according to an accumulated thickness of the film formed on the substrate.
(Supplementary Note 2)
Preferably, the cleaning conditions may be a pressure of the inside of the process chamber and a flowrate of the cleaning gas.
(Supplementary Note 3)
Preferably, a pressure of the inside of the process chamber in the first cleaning process may be set to be lower than a pressure of the inside of the process chamber in the second cleaning process.
(Supplementary Note 4)
Preferably, the first deposition substance may comprise at least one of the plurality of elements as a main component, and the second deposition substance may comprise the plurality of elements as main components.
(Supplementary Note 5)
Preferably, the first process gas may be a silicon-containing gas, and the second process gas may be a nitrogen-containing gas.
(Supplementary Note 6)
Preferably, the cleaning gas may comprise at least one selected from the group consisting of nitrogen trifluoride (NF 3 ) gas, chlorine trifluoride (ClF 3 ) gas, fluorine (F 2 ) gas, hydrogen fluoride (HF) gas, chlorine (Cl 2 ) gas, and boron trichloride (BCl 3 ) gas.
(Supplementary Note 7)
Preferably, in the first cleaning process, the cleaning gas may be continuously supplied to the first gas introducing part, and in the second cleaning process, the cleaning gas may be intermittently supplied to the inside of the process chamber.
(Supplementary Note 8)
According to another embodiment of the present invention, there is provided a cleaning method for removing a film attached to an inside of a process chamber of a substrate processing apparatus which is used to form a film on a substrate by supplying a process gas to the substrate, the cleaning method comprising: setting pressure of the inside of the process chamber to a first pressure and intermittently supplying a cleaning gas to the inside of the process chamber; and setting the pressure of the inside of the process chamber to a second pressure higher than the first pressure and continuously supplying the cleaning gas to the inside of the process chamber.
(Supplementary Note 9)
According to another embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, the method comprising: loading a substrate into a process chamber; forming a film on the substrate by supplying a first process gas, which comprises at least one of a plurality of elements constituting the film and is capable of depositing a film by itself, to an inside of the process chamber through a first gas introducing part, and supplying a second process gas, which comprises at least one of the others of the plurality of elements constituting the film and is incapable of depositing a film by itself, to the inside of the process chamber through a second gas introducing part; unloading the substrate from the process chamber after the film is formed on the substrate; performing a first cleaning process so as to remove a first deposition substance attached to an inner wall of the first gas introducing part by supplying a cleaning gas to the first gas introducing part; and performing a second cleaning process so as to remove a second deposition substance attached to the inside of the process chamber and having a chemical composition different from that of the first deposition substance by supplying a cleaning gas to the inside of the process chamber through a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed, wherein when at least parts of the first cleaning process and the second cleaning process are simultaneously performed, concentration of the cleaning gas supplied to the first gas introducing part is lower than concentration of the cleaning gas supplied through the third gas introducing part.
(Supplementary Note 10)
According to another embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, the method comprising: loading a substrate into a process chamber; forming a film on the substrate by supplying a first process gas, which comprises at least one of a plurality of elements constituting the film and is capable of depositing a film by itself, to an inside of the process chamber through a first gas introducing part, and supplying a second process gas, which comprises at least one of the others of the plurality of elements constituting the film and is incapable of depositing a film by itself, to the inside of the process chamber through a second gas introducing part; unloading the substrate from the process chamber after the film is formed on the substrate; performing a first cleaning process so as to remove a first deposition substance attached to an inner wall of the first gas introducing part by supplying a cleaning gas to the first gas introducing part; and performing a second cleaning process so as to remove a second deposition substance attached to the inside of the process chamber and having a chemical composition different from that of the first deposition substance by supplying a cleaning gas to the inside of the process chamber through a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed, wherein when at least parts of the first cleaning process and the second cleaning process are simultaneously performed, a flowrate of the cleaning gas supplied to the first gas introducing part is lower than a flowrate of the cleaning gas supplied through the third gas introducing part.
(Supplementary Note 11)
According to another embodiment of the present invention, there is provided a substrate processing apparatus comprising: a process chamber configured to accommodate a substrate; a first gas introducing part configured to supply a first process gas, which comprises at least one of a plurality of elements constituting a film to be formed on the substrate and is capable of depositing a film by itself, and a cleaning gas to an inside of the process chamber; a second gas introducing part configured to supply a second process gas, which comprises at least one of the others of the plurality of elements and is incapable of depositing a film by itself, to the inside of the process chamber; a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed and configured to supply a cleaning gas to the inside of the process chamber; an exhaust part configured to exhaust an inside atmosphere of the process chamber; and a control unit configured to control the first gas introducing part, the second gas introducing part, the third gas introducing part, and the exhaust part, wherein after a film is formed on the substrate by supplying the first and second process gases to the inside of the process chamber, the control unit controls the first gas introducing part, the second gas introducing part, the third gas introducing part, and the exhaust part, so as to remove a first deposition substance attached to an inner wall of the first gas introducing part by setting cleaning conditions according to accumulated supply time of the first process gas supplied to the inside of the process chamber through the first gas introducing part and supplying a cleaning gas to the first gas introducing part, and so as to remove a second deposition substance attached to the inside of the process chamber and having a chemical composition different from that of the first deposition substance by setting cleaning conditions according to an accumulated thickness of the film formed on the substrate and supplying a cleaning gas to the inside of the process chamber through the third gas introducing part.
(Supplementary Note 12)
Preferably, the cleaning conditions may be a pressure of the inside of the process chamber and a flowrate of the cleaning gas.
(Supplementary Note 13)
Preferably, the control unit may control the first gas introducing part, the third gas introducing part, and the exhaust part, such that a pressure of the inside of the process chamber when the cleaning gas is supplied through the third gas introducing part is lower than a pressure of the inside of the process chamber when the cleaning gas is supplied through the first gas introducing part.
(Supplementary Note 14)
Preferably, the first deposition substance may comprise at least one of the plurality of elements as a main component, and the second deposition substance may comprise the plurality of elements as main components.
(Supplementary Note 15)
According to another embodiment of the present invention, there is provided a substrate processing apparatus comprising: a process chamber configured to accommodate a substrate; a first gas introducing part configured to supply a first process gas, which comprises at least one of a plurality of elements constituting a film to be formed on the substrate and is capable of depositing a film by itself, and a cleaning gas to an inside of the process chamber; a second gas introducing part configured to supply a second process gas, which comprises at least one of the others of the plurality of elements and is incapable of depositing a film by itself, to the inside of the process chamber; a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed and configured to supply a cleaning gas to the inside of the process chamber; an exhaust part configured to exhaust an inside atmosphere of the process chamber; and a control unit configured to control the first gas introducing part, the second gas introducing part, the third gas introducing part, and the exhaust part, wherein after a film is formed on the substrate by supplying the first and second process gases to the inside of the process chamber, the control unit controls the first gas introducing part, the second gas introducing part, the third gas introducing part, and the exhaust part, so as to set pressure of the inside of the process chamber to a first pressure and supply a cleaning gas intermittently to the inside of the process chamber through the third gas introducing part, and so as to set the pressure of the inside of the process chamber to a second pressure lower than the first pressure and supply the cleaning gas continuously to the inside of the process chamber through the third gas introducing part.
(Supplementary Note 16)
According to another embodiment of the present invention, there is provided a cleaning control apparatus for a process chamber or a silicon-containing gas supply system of a silicon nitride film forming apparatus which is used to form a silicon nitride film having a predetermined silicon/nitrogen composition ratio on a substrate by alternately supplying a silicon-containing gas having a predetermined molecular weight and a nitriding source gas having a predetermined molecular weight, the cleaning control apparatus comprising: a cleaning request signal output unit comprising a memory unit configured to store an accumulated supply amount of silicon-containing gas molecules supplied to an inside of the process chamber through the silicon-containing gas supply system, the cleaning request signal output unit being configured to output a cleaning request signal so as to request cleaning of the silicon-containing gas supply system if the accumulated supply amount of the silicon-containing gas molecules stored in the memory unit becomes equal to or greater than a preset accumulated supply amount of silicon-containing gas molecules; and a cleaning request signal output unit comprising a memory unit configured to store an accumulated supply amount of nitriding source gas molecules supplied to the inside of the process chamber through a nitriding source gas supply system, the cleaning request signal output unit being configured to output a cleaning request signal so as to request cleaning of the nitriding source gas supply system if the accumulated supply amount of the nitriding source gas molecules stored in the memory unit becomes equal to or greater than a preset accumulated supply amount of nitriding source gas molecules.
(Supplementary Note 17)
According to another embodiment of the present invention, there is provided a cleaning control apparatus for a process chamber or a gas introducing part of a substrate processing apparatus which is used to form a predetermined film on a substrate placed in the process chamber by supplying a first process gas comprising at least one of a plurality of elements constituting the film and a second process gas comprising at least one of the others of the plurality of elements constituting the film to an inside of the process chamber through different gas introducing parts, respectively, the cleaning control apparatus comprising: a first monitoring unit configured to monitor a supply amount of the first process gas supplied to the inside of the process chamber through a first introducing part; a first adding unit configured to accumulate the monitored supply amount of the first process gas; a first memory unit configured to store the accumulated supply amount of the first process gas; a first comparison unit configured to compare the accumulated supply amount of the first process gas with a predetermined threshold value; a first signal output unit configured to output a cleaning request signal so as to request cleaning of an inner wall of the first introducing part if the accumulated supply amount of the first process gas is greater than the predetermined threshold valve; a second monitoring unit configured to monitor a supply amount of the second process gas supplied to the inside of the process chamber through a second introducing part; a second adding unit configured to accumulate the monitored supply amount of the second process gas; a second memory unit configured to store the accumulated supply amount of the second process gas; a second comparison unit configured to compare the accumulated supply amount of the second process gas with a predetermined threshold value; and a second signal output unit configured to output a cleaning request signal so as to request cleaning of an inner wall of the second introducing part if the accumulated supply amount of the second process gas is greater than the predetermined threshold valve. | A cleaning control apparatus capable of performing a cleaning process efficiently regardless of qualities and thicknesses of films formed in a process tube and a gas supply nozzle. The cleaning control apparatus employs cleaning request signal output units configured to output cleaning request signals requesting cleaning processes of a silicon-containing gas supply system and nitriding source gas supply system when accumulated amounts of the molecules of the silicon-containing gas and the nitriding source gas exceeds preset values. | 7 |
RELATED APPLICATIONS
This application is a Divisional patent application of co-pending application Ser. No. 12/346,104, filed on 30 Dec. 2008, now pending. The entire disclosure of the prior application Ser. No. 12/346,104, from which an oath or declaration is supplied, is considered a part of the disclosure of the accompanying Divisional application and is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to polyester matrix powders containing carbon nanotube powders dispersed therein; to conductive masterbatches with homogeneous and smooth surfaces and the preparing process thereof; to conductive monofilaments formed from the said conductive masterbatches and the preparing process thereof; and to textiles prepared from the said conductive monofilaments.
2. Description of Related Arts
Carbon nanotubes have been known as graphitizing carbon tubes and are different from conventional carbons in that the carbon nanotubes have a specific character of L/D ratio and can be used as the best conductive materials. Generally, the larger the L/D ratio of carbon nanotubes is, the better the conductivity of the same is. However, if the L/D ratio is too large, problems occur during spinning process. For instance, if the arrangement or orientation of the carbon nanotubes is not good, the drawing process becomes difficult. Further, if the carbon nanotubes fail to pass the fiber filter test, the filaments formed therefrom easily break during spinning process.
In order to enhance the conductivity of polymer matrixes, carbon nanotubes having good dispersibility may be added. The carbon nanotubes are obtainable by a high-speed mechanic force, followed by uniformly dispersing the carbon nanotubes in the polymer matrixes. However, achieving the dispersing effect and enhancing the conductivity of the polymer matrixes via such a high-speed mechanic process are only effective when the concentration of carbon nanotubes is low. If the concentration of the carbon nanotubes is high, the uniform dispersing effect cannot be reached even though the conductivity is increased. On the other side, the longer the carbon nanotubes is, the better the increasing effect of their conductivity is. Nevertheless, if the long length of the carbon nanotubes is disadvantageous to the processability. Such a result is caused by the tanglement of the carbon nanotubes themselves.
Recently, the high-speed shear mixing and processing technology makes the addition of up to 15 wt. % of the carbon nanotubes in the polymer matrix possible. However, the carbon nanotubes have poor dispersibility in the polymer materials by their process.
In other conventional methods, carbon nanotubes are dispersed in a strong acid solution to shatter the aggregates of the carbon nanotubes via ultrasonic wave. Specifically, the aggregates may be shattered in a mixed acid solution containing H 2 SO 4 and HNO 3 in a ratio of 3:1 at 50° C. via ultrasonic wave over a time period of 24 hours. The carbon nanotubes treated by a strong acid solution are easy to produce a COOH group that may increase the dispersibility of carbon nanotubes. However, this method has disadvantages in that the carbon nanotubes treated by a strong acid solution cause defects on the surfaces of their structures, and thus the properties and functions of the carbon nanotubes will be greatly reduced.
The prior art, for instance, CN1475437A discloses a process for the preparation of a carbon nanotube paper, comprising the steps of: purifying carbon nanotubes, dispersing the carbon nanotubes and forming a carbon nanotube paper; wherein the carbon nanotubes are repeatedly treated until the impurities are removed and the carbon nanotubes are sufficiently dispersed. Such processes have several disadvantages, such as: 1) the procedure is very complicated and costly; 2) the surfaces of carbon nanotubes treated with a strong acid will be destroyed and the properties, such as antistatic ability, conductivity or strength, of the carbon nanotubes become poor; 3) it is difficult to disperse the carbon nanotubes in a solvent and the solvent used causes an environmental problem; and 4) the surfaces of the carbon nanotubes are destroyed due to the treatment with a strong acid and the yield is only about 30 to 60%, whereby the production cost of the carbon nanotubes is significantly increased.
CN1563526A discloses conductive fibers containing carbon nanotubes and the preparing process thereof. The conductive fibers comprise 80 to 99.9 wt. % of a polyester, 0.05 to 10 wt. % of carbon nanotubes and 0.05 to 10 wt. % of a coupling agent, wherein the coupling agent is selected from OP wax, montan wax, polyethylene vinyl acetate or aluminate. In this known technology, the carbon nanotubes are untangled under a strong shear force, thereby being homogeneously dispersed within the polyester matrix. In this process, only a lower content of carbon nanotubes is required for preparing conductive fibers. According to this process, the coupling agent is added after the polyester and carbon nanotubes are dried under vacuum, followed by mixing them at a high speed and at a temperature of 70 to 120° C. After that, masterbatches are prepared at a speed of 40 to 150 rpm by using a twin-screw mixer. According to this process, it is difficult to untangle the carbon nanotubes due to the long length L (=100 μm) of carbon nanotubes, as shown in the examples of this China application. Thus, filaments formed from the said carbon nanotubes fail to pass the filter test and possibly break during spinning process. Furthermore, due to the coupling agent and low content of the carbon nanotubes, the increase of the conductivity of the filaments formed according to such a process is limited. In addition, the carbon nanotubes are drawn out during the vacuum dryness procedure for the polyester and carbon nanotubes, and the conductivity of the carbon nanotubes is reduced because of the low content of carbon nanotubes. The masterbatches from the carbon nanotubes prepared by this process exhibit poor physical properties. It is necessary to use bi-component composite spinning method to produce filaments. Moreover, the conductivity of the filaments is lowered and the textiles prepared therefrom merely exhibit an antistatic effect and have a surface resistance of 1.2×10 6 Ω/sq.
Further, CN1584141A discloses conductive composite fibers colored with original liquid by composite spinning process, characterized in that the fibers are composed of a core layer and a sheath layer, wherein the core layer is a polyester containing 2 to 60% of conductive components selected from a conductive carbon black, a carbon nanotube, a nano-graphite or conductive metal oxides, which has a surface resistance of less than 10 6 Ω·cm. The process of this China application comprises dispersing the conductive particles by melt-state mixing. The masterbatches formed from the carbon nanotube according to this process have unstable physical properties. Thus, it is necessary to use a bi-component spinning procedure to enhance the mechanical properties of fibers.
CN1869291A discloses a fiber structure of nano compound material containing a polyester and a carbon nanotube, wherein the polyester and carbon nanotube are dispersed in a solvent to form a stable dispersion containing polyester/carbon nanotube, and then a fiber structure of nano compound material containing a polyester and a carbon nanotube, such as the structures of a fiber and a non-woven fabric or film formed therefrom is prepared by electrostatic spinning. The formed fiber or non-woven fabric or film has a conductivity of 10 −17 to 10 2 S/cm. In this process, the carbon nanotube is dispersed in the polyester by ultrasonic or mechanical or electromagnetic stirring step.
U.S. Pat. No. 7,094,467B2 discloses an antistatic polymer monofilament and the preparing process thereof. The antistatic polymer monofilament comprises a polymer composite of a thermoplastic polymer as a matrix and carbon nanotubes as a conductive filler. The textiles formed from the monofilament have a surface resistance of 10 4 to 10 9 ω/sq. However, the textiles only exhibit an antistatic effect and haves a surface resistance of 2×10 7 ω/sq.
In the conventional technology, carbon nanotubes is generally added in the polymer in an amount of 2 wt. % or less. Such an amount of the carbon nanotubes limits the increase of the conductivity. It is known that the dispersibility of the carbon nanotubes is poor and may result in breakage, brittleness and difficulties in granulating the polymer matrix when the carbon nanotubes in the polyester matrix are in an amount of 5 wt. % or more. The problems and disadvantages stated above may be solved by the addition of a dispersant and a chain extender.
Accordingly, in order to obtain conductive monofilaments containing a low content of carbon nanotubes and having good conductivity and excellent spinning processability as well as to avoid the above-mentioned disadvantages and problems, the present invention provides novel conductive polyester materials, which comprises polyester matrix powders containing a homogeneously dispersed carbon nanotube, a dispersants and a chain extender.
SUMMARY OF THE INVENTION
The object of the present invention is to provide polyester matrix powders containing carbon nanotube powders dispersed therein and having excellent electrical conductivity, the applications of conductive masterbatches, conductive monofilamens and textiles, and the processes for preparation of the same.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a polyester matrix powder containing carbon nanotube powders homogeneously dispersed therein, wherein the polyester matrix powder comprises:
A) a polyester polymeric matrix based on polybutylene terephthalate(PBT) or the copolymers thereof, B) carbon nanotube powders which have been milled at a ultrahigh speed, C) a dispersant, and D) a chain extender,
wherein the above components A), B), C) and D) are mixed in a high-speed powder mixer, to obtain a polyester matrix powder.
For component A) of the present invention, polybutylene terephthalate or the copolymer thereof is selected from the group consisting of polybutylene terephthalate homopolymer, copolyester containing butylene terephthalate (BT) as the repeat unit and block copolymer containing polybutylene terephthalate, or the combination thereof. Polybutylene terephthalate homopolymer is preferred.
According to one embodiment of the present invention, the polybutylene terephthalate or the copolymer thereof has an intrinsic viscosity (I.V.) of 0.6 dl/g or more. Preferably, the intrinsic viscosity (I.V.) is in a range of 0.8 to 1.3 dl/g, determined in 50/50 (v/v) of tetrachloroethane/phenol at 25° C.
In this invention, the content of the component A) is 80 to 99.5 wt. %, preferably 84 to 99 wt. %, more preferably 88 to 97 wt. %, based on the weight of polyester matrix powder.
Suitable carbon nanotube in the present invention has a purity of 90% and is milled by means of an ultrahigh-speed powder pulverizer to form a dispersed carbon nanotube powder. According to a preferred embodiment of the present invention, the carbon nanotube powder is milled by means of a powder pulverizer at a speed of 20,000 to 30,000 rpm for 5 to 20 minutes, thereby forming a carbon nanotube powder with a good dispersibility and having a length (L) of less than 3.0 μm (micrometer) and a L/D value of greater than 100. Preferably, the carbon nanotube powder after milling has a length (L) of 0.7 to 3 μm and a L/D value of 100 to 300.
According to an embodiment of the present invention, the carbon nanotube contained in the carbon nanotube powder has an average diameter of 0.5 to 50 nm (nanometer) and an L/D value of 60 to 600.
The content of carbon nanotube powder according to the present invention is 1 to 15 wt. %, preferably 1 to 10 wt. %, more preferably 2.5 to 10 wt. %, and most preferably 3 to 10 wt. %, based on the weight of polyester matrix powder.
The polyester matrix powder of the present invention contains a dispersant as component C). The dispersant exhibits processing stability and functions of improved dispersibility and flowability. During the processing process, the dispersant may produce a free radical that combines the carbon nanotube with the dispersant. Suitable dispersant used in the present invention is an ethylene-acrylic copolymer. According to one preferred embodiment of the present invention, the dispersant is ethylene-acrylic acid copolymer.
The content of the dispersant in the present invention is 0.01 to 6.0 wt. %, preferably 0.1 to 2.0 wt. %, more preferably 0.2 to 1.5 wt. %, based on the weight of polyester matrix powder.
In the present invention, to reinforce the processing ability of the polyester fiber, such as size stability, thermal stability, etc., a chain extender as component D) may be added. The smaller molecular chain segment in the polymer is extended to form longer one by the combination of the unique functional group in the chain extender with the smaller molecular chain segment, i.e. carboxyl group (—COOH), thereby enhancing the properties of the materials, such as intrinsic viscosity (I.V.), thermal stability, size stability, etc. and avoiding the influence of the high-temperature mixing and spinning processes on the physical properties of the materials.
According to the present invention, suitable chain extender is selected from the group consisting of a diisocyanatocycloalkane or an oxazoline. The exemplary compounds are diisocyanatocycloalkane of formula (I),
bis-oxazoline of formula (II),
1,4-phenylene-bis-oxazoline,
2,2′-methylene bis[(4S)-4-tert-butyl-2-oxazoline] of formula (IV),
2,2′-methylene bis[(4S)-4-phenyl-2-oxazoline] of formula (V),
The content of the chain extender in the present invention is 0.01 to 6.0 wt. %, preferably 0.1 to 1.0 wt. %, more preferably 0.1 to 0.8 wt. %, based on the weight of polyester matrix powder.
According to the present invention, A) a polyester polymeric matrix, B) a carbon nanotube powder milled at ultrahigh speed, C) a dispersant and D) a chain extender are mixed by means of a solid dispersing and blending technology. According to one embodiment of the present invention, the carbon nanotube powder is quickly and homogeneously dispersed in the polyester polymeric matrix in a high-speed powder mixer at a speed of 1,000 to 3,000 rpm for 10 to 60 minutes to obtain a polyester matrix powder containing a homogeneously dispersed carbon nanotube powder.
Accordingly, one further object of the present invention is to provide a process for the preparation of a polyester matrix powder containing a homogeneously dispersing carbon nanotube, characterized in that the process comprises the steps of:
1) providing a carbon nanotube with a purity of more than 90% and having a length (L) of less than 2 μM and a L/D value of more than 100, 2) feeding the carbon nanotube into a ultrahigh-speed powder pulverizer at a speed of 20,000 to 30,000 rpm to mill the carbon nanotube for 5 to 20 minutes to form a carbon nanotube powder with good dispersibility, 3) adding the dispersed carbon nanotube powder obtained from step 2) into a polybutylene terephthalate polymeric material and then adding a dispersant and a chain extender to form a polyester matrix mixture, 4) feeding the polyester matrix mixture into a high-speed powder mixer and mixing the mixture at a speed of 1,000 to 3,000 rpm for 10 to 60 minutes to quickly and homogeneously dispersing the carbon nanotube powder in the polyester matrix mixture, thereby forming a polyester matrix powder containing a homogeneously dispersing carbon nanotube.
Suitable carbon nanotube used in the process of the present invention has a purity of more than 90%. The carbon nanotube after milling has a length (L) of less than 3.0 μM and an L/D value of more than 100. According to one embodiment of the process of the present invention, the carbon nanotube after milling has a length (L) of 0.7 to 2.0 μm and an L/D value of 100 to 300. According to a preferred embodiment of the present invention, the carbon nanotube in the carbon nanotube powder has an average diameter of 0.5 to 50 nm and an L/D value of 60 to 600.
In the process of the present invention, suitable polybutylene terephthalate (PBT) polymer matrix is selected from the group consisting of a polybutylene terephthalate or the copolymers thereof. Preferably, the polymer matrix is selected from the group consisting of a polybutylene terephthalate homopolymer, a copolyester containing butylene terephthalate (BT) as the repeat unit and a block copolymer containing polybutylene terephthalate unit, or the combination thereof. The polybutylene terephthalate homopolymer is preferred. According to one preferable embodiment of the present invention, polybutylene terephthalate or the copolymers thereof has an intrinsic viscosity (I.V.) of more than 0.6 dl/g, preferably an intrinsic viscosity (I.V.) of 0.8 to 1.3 dl/g, determined in 50/50 (v/v) of tetrachloroethane/phenol at 25° C.
In the process of the present invention, the dispersant may be the one(s) having an improved processing stability, dispersibility and flowability, such as ethylene-acrylic copolymer. The preferable dispersant is ethylene-acrylic acid copolymer.
In the process of the present invention, the chain extender is selected from the group consisting of a diisocyanatocycloalkane and an oxazoline. As stated above, the exemplary chain extender is diisocyanatocyclohexane of formula (I), bis-oxazoline of formula (II), 1,4-phenylene-bis-oxazoline of formula (III), 2,2′-methylene bis[(4,s)-4-tert-butyl-2-oxazoline] of formula (IV) or 2,2′-methylene bis[(4,s)-4-phenyl-2-oxazoline] of formula (V). Preferably, the chain extender is bis-oxazoline of formula (II), 1,4-phenylene-bis-oxazoline of formula (III), 2,2′-methylene bis[(4,s)-4-tert-butyl-2-oxazoline] of formula (IV) or 2,2′-methylene bis[(4,s)-4-phenyl-2-oxazoline] of formula (V).
The polyester matrix powder obtained by the above process may further be processed and mixed to form electrically conductive masterbatches.
Thus, the further object of the present invention is to provide conductive masterbatches with homogeneous and smooth surfaces, characterized in that the conductive masterbatches are obtained from the polyester matrix powder which is prepared by mixing and granulation via twin-screw mixer according to the process of the present invention, to form conductive masterbatches with homogeneous and smooth surfaces.
According to an embodiment of the present invention, the polyester matrix powder is mixed and granulated by means of twin-screw mixer at a temperature of 220 to 300° C., preferably 230 to 285° C., and at a screw speed of 300 to 400 rpm, preferably 200 to 350 rpm, more preferably 350 rpm.
In the present invention, the obtained conductive masterbatches may pass a filter test, such as 60 μm-screen filter test. According to an embodiment of the present invention, the formed conductive masterbatches have a resistance of less than 10 8 Ω/sq, preferably 10° to 10 8 Ω/sq, more preferably 10° to 10 5 Ω/sq, most preferably 10 1 to 10 4 Ω/sq, and very preferably 10 1 to 10 3 Ω/sq.
The further one object of the present invention is to provide a process for the preparation of conductive masterbatches with homogeneous and smooth surfaces, wherein the process comprises the steps of:
1) providing a polybutylene terephthalate (PBT) polymeric matrix powder comprising a carbon nanotube powder with good dispersibility, a dispersant and a chain extender, wherein the carbon nanotube is milled in a ultrahigh-speed powder grinder to form a homogeneously dispersed carbon nanotube powder before the addition to the PBT polymer material, 2) feeding the PBT polymeric matrix powder into twin-screw mixer and mixing and granulating the powder at a temperature of 220 to 300° C., preferably 230 to 285° C., and at a screw speed of 300 to 400 rpm, preferably 200 to 350 rpm, more preferably 350 rpm, thereby forming conductive masterbatches with homogeneous and smooth surfaces.
The present invention is further to provide a conductive monofilament prepared from the conductive masterbatches obtained by the process of the present invention via spinning procedure.
The conductive monofilament formed according to the present invention has a diameter of 0.05 to 1.0 mm, preferably 0.1 to 0.5 mm. According to the present invention, the conductive monofilament has a volume specific resistance of 10 4 Ω·cm or less, preferably 10 3 Ω·cm or less, and more preferably 10 1 to 10 3 Ω·cm. The conductive monofilament formed according to the present invention has a strength of more than 0.8 gf/d, preferably 1.0 to 4.0 gf/d, more preferably 1.0 to 2.0 gf/d. Further, the conductive monofilament formed according to the present invention has an elongation of more than 10%, preferably 10 to 100%, more preferably 10 to 70%.
Further, the present invention provides a process for the preparation of the conductive monofilament, comprising the steps of:
1) providing conductive masterbatches formed from a polybutylene terephthalate (PBT) polymer matrix powder which contains a dispersed carbon nanotube powder, a dispersant and a chain extender, wherein the carbon nanotube powder is homogeneously dispersed in the polymer matrix powder, 2) baking and drying the conductive masterbatches at 110° C. over a time period of 12 hours to obtain dried conductive masterbatches, 3) feeding the dried conductive masterbatches into a single-screw and extruding the masterbatches through a 60 μm-screen filter at a processing temperature of 250 to 285° C. and at a screw speed of 20 rpm, followed by spinning via a spinning nozzle with a pore diameter of 0.5 mm and a length of 1 mm at a single-pore extruding rate of 6 g/minutes to form a filament, 4) cooling the spun filament via a cooling device at a cooling rate of 10 to 30 m/minutes, and then winding the filament at a winding rate of 40 to 100 m/minutes to form a conductive monofilament.
The present invention further provides textiles obtained from the conductive monofilament by processing and shaping procedures, wherein the textiles have a surface resistance of less than 10 5 Ω/sq, preferably 10 1 to 10 5 Ω/sq.
The present invention is characterized in that the carbon nanotube powder is dispersed and the carbon nanotube powder is untangled by means of a ultrahigh-speed, high-strength mechanical force. The advantages of the process according to the present invention is simple, quick, low-cost and free of environmental problems as well as the yield of more than 95% for the carbon nanotube.
According to the present invention, the obtained polyester matrix powder containing homogeneously dispersed carbon nanotube powder is suitable for the preparation of conductive polymer masterbatches with homogeneous and smooth surfaces, of conductive monofilament (such as antistatic or conductive monofilament or multifilament), etc. Further, the conductive monofilament prepared according to the process of the present invention is suitable for the preparation of textiles, such as textiles for filtration, a brush for electronic devices, a running belt, a delivering belt, a packaging material, a clean room or ESD (such as petrochemical industry, aircraft industry, explosive, spraying paint, etc.) or an anti-electromagnetic wave EMI, etc., a dust-proof cloth and an antistatic product (such as antistatic/conductive cloth, anti-electromagnetic cloth, antistatic/conductive groove, antistatic/conductive woven belt, antistatic shoe material, antistatic packaging material, antistatic furniture cloth/carpet, etc.)
In the present invention, the percentage shown in the present description and claims refers to a percentage based on the weight, unless indicated otherwise. The invention is illustrated in greater detail by the examples described below. The examples are not intended in any way to limit the scope of the invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope are approximations, the numerical values set forth in the specific example are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in its respective testing measurements. The present invention is now to be explained in more detail with the aid of the following examples.
EXAMPLES
A. Types and Characters of Materials
1. Polybutylene terephthalate(PBT) has an intrinsic viscosity (I.V.) of 1.0 dl/g, determined in 50/50 (v/v) of tetrachloroethane/phenol at 25□. Trademark Name: 1100M, available from Changchun Group.
2. Carbon nanotube (CNT) powder, Trademark Name: Nanocyl 7000 available from Nanocyl S.A., Belgian, has an average diameter of 9.5 nm, an average length of 1.5 μm, a length/diameter ratio (L/D) value of 158, a carbon-containing purity of 90% and a specific surface area of 250 to 300 m 2 /g.
3. Dispersant is, Trademark Name: Wax series A-C 540A available from Honeywell, ethylene-acrylic acid copolymer having a melting point of 105° C.
4. Chain extender is a compound of 2,2′-methylene bis[(4,s)-4-phenylene-2-oxazoline], available from Shanghai Crystalline-Purifying Regent, Ltd.
B. Device Models
1. Ultrahigh-speed, high-strength mechanical device is used for dispersing carbon nanotube, Device Model: Model RT-08 grinder with a speed of 20,000 to 30,000 rpm, available from Mill Powder Tech Solution.
2. High-speed complex powder blending grinder is for homogeneously dispersing carbon nanotube within polymeric material, Device Model: Model FM-20 device having a speed of 1,000 to 3,000 rpm, available from MitsuiMining Co., Ltd. (Japan).
3. Twin-screw mixer/Twin-screw extruder is available from HAAKE (Germany).
4. Polymer melt filter device/Filter screen test device for elevating the distribution of carbon nanotube is a device having a 60 μm of filtering screen, available from HAAKE (Germany).
5. The main device of monofilament spinner is available from HAAKE (Germany), wherein the spinning nozzle has a pore diameter of 0.5 mm, a length of 1 mm, and the upper of the spinning nozzle is equipped with a filtering screen having a diameter of 60 μm for filtering impurities and for enhancing the stability and quality of the spun fiber.
C. The Property Testing of Masterbatches and Fibers
1. Testing for the conductivity of conductive PBT masterbatches
PBT masterbatches are heated and melted, and then pressed to form a square sample with 5 cm×5 cm and a thickness of about 1 mm. The conductivity, i.e. surface resistance (Ω/sq), of the samples is determined by using a 4-pin probe low resistivity meter (Model: MCP-T600, available form Mitsubishi Chemical (Japan)).
2. Testing for the Conductivity of Conductive PBT Monofilament
The conductivity of PBT monofilament is determined by standard method of DIN 54345, wherein the testing distance is 10 cm. The determined resistance is divided by 10 cm to calculate a fiber resistivity (Ω/cm), followed by multiplying the fiber resistivity by the section area of the fiber to yield the volume specific resistance (Ω·cm) of fiber.
3. Testing for the Conductivity of Textiles Prepared from PBT Monofilament
The conductivity of the textiles prepared from PBT monofilament is determined by using the standard method of EN 1149-1: 1996 at a temperature of 23±1° C. and a humidity of 25±5% by means of a surface resistance determining meter.
4. Testing for the Rise of Pressure
The rise of pressure is determined by using a pressure testing device available from HAAKE (Germany) with a 60 μm of filtering screen for the filter testing of conductive masterbatches.
5. Evaluation of Spinnability
The spinning test of the conductive fiber is carried out by using a monofilament spinner available from HAAKE (Germany) at a spinning temperature of 250 to 285° C. and at a screw speed of 20 rpm to evaluate whether the filament breaks.
6. Testing for the Properties of the Tensile Strength, Force and Elongation of the Conductive Monofilament
The force, strength and elongation of the conductive monofilament are determined by using a Tensile strength testing machine available from Gotech Testing Machines Inc. (Taiwan) at an ambient temperature of 25° C., a distance of 250 mm between carriers, a tensile speed of 250 mm/minutes. The Maximum force of breaking the filament refers to the force of monofilament. The strength of the monofilament is obtained from the force of the filament divided by the danier number of the filament. The elongation of monofilament is obtained from the result of the elongation at break divided by the distance of 250 mm.
A. Preparation of Polyester Matrix Powders Containing Dispersed Carbon Nanotubes
Comparative Example 1 (C. Ex. 1)
Polybutylene terephthalate(PBT) polymeric matrix is fed into a high-speed composite powder mixer and is mixed at a speed of 2000 rpm over a time period of 30 minutes to obtain a PBT polyester matrix powder as the control.
Comparative Example 2 (C. Ex. 2)
1932 g (96.60%) of polybutylene terephthalate (PBT) polymeric material, 60 g (3.00%) of Nanocyl 7000 carbon nanotube, 4 g (0.20%) of A-C 540A as a dispersant and 4 g (0.20%) of 2,2′-methylene[(4,s)-4-phenyl-2-oxazoline] are mixed to obtain PBT polyester matrix powder as a control containing carbon nanotube powder, where the Nanocyl 7000 carbon nanotube in this comparative example is dispersed and mixed without using a ultrahigh-speed, highly strong force and without using a high-speed, highly strong mechanical force.
Comparative Example 3 (C. Ex. 3)
Analogously to Comparative Example 2, 1870 g (93.50%) of polybutylene terephthalate (PBT) polymeric material, 120 g (6.00%) of Nanocyl 7000 carbon nanotube, 6 g (0.30%) of A-C 540A dispersant and 4 g (0.20%) of 2,2′-methylene[(4,s)-4-phenyl-2-oxazoline] are mixed to obtain PBT polyester matrix powder containing carbon nanotube powder.
Comparative Example 4 (C. Ex. 4)
1870 g (93.50%) of polybutylene terephthalate(PBT) polymeric material, 120 g (6.00%) of Nanocyl 7000 carbon nanotube, 6 g (0.30%) of A-C 540A dispersant and 4 g (0.20%) of 2,2′-methylene[(4,s)-4-phenyl-2-oxazoline] are mixed. The obtained PBT polymeric matrix mixture is fed into a high-speed compounding powder mixer and mixed at a speed of 2000 rpm for 30 minutes to obtain PBT polyester matrix powder containing carbon nanotube powder. The Nanocyl 7000 carbon nanotube in this comparative Example was dispersed without using ultrahigh-speed, highly strong mechanical force.
Comparative Example 5 (C. Ex. 5)
Nanocyl 7000 carbon nanotube is fed into an ultrahigh-speed powder grinder and milled at a speed of 30000 rpm for 5 minutes to form a carbon nanotube powder with good dispersibility.
120 g (6.00%) of the carbon nanotube powder and 6 g (0.30%) of A-C 540A dispersant are added to 1874 g (93.70%) of polybutylene terephthalate (PBT) polymeric matrix and mixed to obtain a PBT polyester mixture. Then, the polyester mixture is fed into a high-speed composite powder mixer and mixed at a speed of 2000 rpm for 30 minutes in order to quickly and homogeneously dispersing the Nanocyl 7000 carbon nanotube powder in the PBT polyester matrix, thereby obtaining PBT polyester matrix powder containing homogeneously dispersed carbon nanotube powder. In this Comparative Example, the polyester matrix powder contains no chain extenders.
Example 1 (Ex. 1)
Nanocyl 7000 carbon nanotube is fed into an ultrahigh-speed powder grinder and milled at a speed of 30000 rpm for 5 minutes to form a carbon nanotube powder with good dispersibility.
20 g (1.00%) of the carbon nanotube powder, 2 g (0.10%) of A-C 540A dispersant and 2 g (0.10%) of 2,2′-methylene[(4,s)-4-phenyl-2-oxazoline] are added to 1976 g (98.80%) of polybutylene terephthalate (PBT) polymeric matrix and mixed to obtain a PBT polyester mixture. Then, the polyester mixture is fed into a high-speed composite powder mixer and mixed at a speed of 2000 rpm for 30 minutes in order to quickly and homogeneously dispersing Nanocyl 7000 carbon nanotube powder in PBT polyester matrix, thereby obtaining a PBT polyester matrix powder containing homogeneously dispersed carbon nanotube powder.
Examples 2 to 6 (Ex. 2 to Ex. 6)
Analogously to Example 1, the PBT polyester matrix powder of Examples 2 to 6 containing homogeneously dispersed carbon nanotube powder are prepared according to the composition ratios shown on table 1.
TABLE 1 CNT (Nanocyl 7000) Dispersing Dispersing without with high- high-speed, speed, highly Chain highly strong strong me- Dispersant extender, PBT, g mechanic chanic force, A-C540A, g (wt. %) force, g (wt. %) g (wt. %) g (wt. %) (wt. %) Controls C. Ex. 1 2000 — — — — (100%) — — — — C. Ex. 2 1932 60 — 4 4 (96.60%) (3.00%) — (0.20%) (0.20%) C. Ex. 3 1870 120 — 6 4 (93.50%) (6.00%) — (0.30%) (0.20%) C. Ex. 4 1870 120 — 6 4 (93.50%) (6.00%) — (0.30%) (0.20%) C. Ex. 5 1874 — 120 6 — (93.70%) — (6.00%) (0.30%) — According to the present invention Ex. 1 1976 — 20 2 2 (98.80%) — (1.00%) (0.10%) (0.10%) Ex. 2 1932 — 60 4 4 (96.60%) — (3.00%) (0.20%) (0.20%) Ex. 3 1970 — 120 6 4 (93.50%) — (6.00%) (0.30%) (0.20%) Ex. 4 1968 — 120 8 4 (93.40%) — (6.00%) (0.40%) (0.20%) Ex. 5 1824 — 160 12 4 (91.20%) — (8.00%) (0.60%) (0.20%) Ex. 6 1775 — 200 20 5 (88.75%) — (10.00%) (1.00%) (0.25%)
B. Preparation and Property Testing for Conductive Masterbatches
Each of PBT polymeric matrix powders prepared by Comparative Example 1 to 5 and Examples 1 to 6 is fed into a twin-screw mixer and then mixed and granulated at a temperature of 230 to 300° C. and a screw speed of 350 rpm to prepare conductive masterbatches.
The masterbatches obtained from Comparative Example 1 to 5 and Example 1 to 6 respectively refer to as sample Nos.: C-PBT, PCN3-0, PCN6-1, PCN6-2, PCN6-3, PCN1-1, PCN3-1, PCN6-4, PCN6-5, PCN8-5 and PCN10-1, and the dispersibility of the carbon nanotube are evaluated by using a filter screen testing machine, available from HAAKE (Germany), with a 60 μm screen. Dispersibility is evaluated by the determination of the pressure rise in the filter test and the result is shown on table 2.
TABLE 2
Dispersing PBT +
CNT (Nanocyl 7000)
CNT + dispersant +
Dispersing
chain extender with
The distribution of CNT in
without
Dispersing with
high-speed, highly
polymeric matrix
ultrahigh-speed,
ultrahigh-speed,
strong mechanic force
change of
Evaliation
PBT
highly strong
highly strong
(high-speed
Surface
preessure
of
Sample
matrix
mechanic force
mechanic force
compounding
resistance
rise
spinning
Nos.
powder
(wt. %)
(wt. %)
powdermixer)
(Ω/sq)
(ΔPa/min )
ability
C-PBT
C. Ex. 1
0%
—
—
>10 13
<2
Pa/20 min
—
PCN3-0
C. Ex. 2
3.00%
—
w/o
2 × 10 4
>90
Pa/8 min
Very poor
PCN6-1
C. Ex. 3
6.00%
—
w/o
4 × 10 2
>150
Pa/9 min
Very poor
PCN6-2
C. Ex. 4
6.00%
—
w
3 × 10 2
>50
Pa/10 min
Very poor
PCN6-3
C. Ex. 5
—
6.00%
w
difficult to granulate
PCN1-1
Ex. 1
—
1.00%
w
1 × 10 8
<2
Pa/20 min
excellent
PCN3-1
Ex. 2
—
3.00%
w
8 × 10 3
<10
Pa/70 min
good
PCN6-4
Ex. 3
—
6.00%
w
2 × 10 2
<10
Pa/50 min
good
PCN6-5
Ex. 4
—
6.00%
w
1 × 10 2
<5
Pa/100 min
good
PCN8-5
Ex. 5
—
8.00%
w
6 × 10 1
<10
Pa/90 min
good
PCN10-1
Ex. 6
—
10.00%
w
7
<10
Pa/50 min
good
In overall, the lower the rise pressure is, the better the distribution of the carbon nanotube in PBT polyester matrix is. As shown on the result of table 2, the conductive masterbatches (such as PCN3-0 and PCN6-1) formed from polyester matrix powder which contains carbon nanotube which is dispersed without using a high-speed, highly strong mechanic force has a higher pressure rise and exhibits poor spinning ability. The conductive masterbatches (PCN6-2) formed from PBT polyester matrix powder dispersed with a high-speed, highly strong mechanic force and then granulated has a lower pressure rise but poor spinning ability. Further, if the PBT matrix powder contains no chain extenders, the conductive masterbatches (such as PCN6-3) formed therefrom are difficult to granulate or cannot be granulated.
In contrast, according to the present invention, the conductive masterbatches (such as PCN3-1, PCN6-4, PCN6-5, PCN8-5 and PCN10-1) formed from the PBT polyester matrix powder which contains a homogeneously dispersed carbon nanotube, a dispersant and a chain extender have lower pressure rise and exhibit better spinning ability.
The conductive resistance is tested for the conductive masterbatches formed from the PBT matrix powders which are prepared by the above Examples and Comparative Examples and the results are shown on table 2.
As shown on table 2, the surface resistance of the conductive masterbatches according to the present invention, which is formed from the PBT polyester matrix powder containing a homogeneously dispersed carbon nanotube, a dispersant and a chain extender, are decreased as the content of the carbon nanotube is increased. Namely, it appears that the conductivity of the conductive masterbatches is increased as the content of the carbon nanotube is increased. On the other side, as compared with the masterbatches (C-PBT) prepared from a pure PBT polyester matrix powder, the conductive masterbatches (such as PCN3-1, PCN6-4, PCN6-5, PCN8-5 and PCN10-1) formed from the PBT polyester powder according to the present invention have a significantly increased conductivity. In addition, as compared with the conductive masterbatches prepared from the PBT matrix powder containing the same amount of carbon nanotube dispersed without the use of a high-speed, highly mechanical force (such as PCN6-1, PCN6-2) or from the PBT matrix powder containing no chain extenders (such as PCN6-3), the conductive masterbatches (such as PCN6-4, PCN6-5) according to the present invention exhibit better conductivity and lower surface resistance.
C. Preparation and Property Test of the Conductive PBT Monofilament
The conductive masterbatches, C-PBT, PCN1-1, PCN3-1, PCN6-4, PCN6-5, PCN8-5 and PCN10-1, are baked and dried at a temperature of 1100 over a period of 12 hours to obtain dried conductive masterbatches. The dried conductive masterbatches are fed into a single-screw extruder, and are extruded at a processing temperature of 250 to 285° C. and at a screw speed of 20 rpm through a 60 μm of filtering screen and then are spun through a spinning nozzle with a pore diameter of 0.5 mm and a length of 1 mm at a single pore extruding output of 6 g/minutes. After that, the spun filaments are cooled by a cooling device at a cooling speed of 5 to 30 m/minutes and then winded at a winding speed of 40 to 100 m/minutes. After the cooling and crimping procedures, the conductive monofilaments (Nos.: F-PBT, F-PCN1-1, F-PCN3-1, F-PCN6-4, F-PCN6-5, F-PCN8-5 and F-PCN10-1) are formed.
The conductivity, tension, strength and elongation of the thus-prepared conductive monofilaments are determined and the result is shown on table 3.
TABLE 3
Volume
Content
specific
Conductive
PBT
of carbon
Fiber
resistance
Surface
Sample
masterbatches
matrix
nanotube,
diameter
Denier
of fiber
resistance
Tension
Strength
elongation
Nos.
Nos.
powder
wt. %
(mm)
(D)
(Ω · cm)
(Ω/sq)
(Kg)
(gf/d)
(%)
F-PBT
C-PBT
C. Ex. 1
0
0.27
698
—
—
1.47
2.1
100
F-PCN1-1
PCN1-1
Ex. 1
1
0.25
600
—
10 9
0.83
1.4
80
F-PCN3-1
PCN3-1
Ex. 2
3
0.24
552
3.3 × 10 3
10 5
0.73
1.3
60
F-PCN6-4
PCN6-4
Ex. 3
6
0.26
648
1.6 × 10 2
10 3~4
0.753
1.1
35
F-PCN6-5
PCN6-5
Ex. 4
6
0.28
751
3.6 × 10 2
10 3~4
0.8
1.1
37
F-PCN8-5
PCN8-5
Ex. 5
8
0.205
403
26
10 3
0.562
1.3
18
F-PCN10-1
PCN10-1
Ex. 6
10
0.205
403
12
10 2-3
0.58
1.44
19
As shown on table 3, the conductive monofilaments prepared from conductive masterbatches formed by polybutylene terephthalate polymeric matrix powders which respectively contain 3%, 6%, 8% and 10% of dispersed carbon nanotube powders have a better conductivity in a range of up to 10 2 to 10 5 Ω/sq. As compared with the monofilament (F-PBT) prepared from a pure polybutylene terephthalate masterbatches, the monofilaments prepared from the conductive masterbatches according to the present invention have better tension and stable strength.
While the embodiments of the present invention described herein are presently preferred, various modifications and improvements can be made without departing from the spirit and scope of the present invention. The scope of the present invention is indicated by the appended claims, and all changes that fall within the meaning and range of equivalents are intended to be embraced therein. | The present invention relates to a polyester matrix powder comprising a polybutylene terephthalate, a homogeneously dispersed carbon nanotube powder, a dispersant and a chain extender; to a conductive masterbatch with homogeneous and smooth surface; to a process for the preparation of the conductive masterbatch; to a conductive monofilament prepared from the conductive masterbatch; to a process for the preparation of the conductive monofilament; and to a fabric article prepared from the monofilament. The present invention is characterized in the preparation of carbon nanotube-containing fiber materials with higher conductivity and the improvement of the spinning property of the conductive masterbatches to avoid blocking and yarn breakage during the spinning process. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to a well screen such as an oil well screen and, more particularly, to a method of manufacturing a selective isolation screen in which, in a wire wrapped screen, seal means for isolating and sealing annulus defined by spacer members disposed on the outer surface of a base member such as a slitted pipe is provided at selected locations in the longitudinal direction.
A screen which is used most frequently as a deep well screen such as an oil well screen has a perforated pipe formed with multitudes of circular openings or slits as its base member, a plurality of spacer rods extending in the longitudinal direction arranged at intervals in the circumferential direction on the outer surface of the base member and a wire wound spirally on the outer periphery of the spacer rods with a predetermined gap. By the provision of the spacer rods, annulus defined by the spacer members and extending in the longitudinal direction is formed between the inside of the wire and the outer surface of the base member over the entire periphery of the base member.
This annulus defined between the inside of the wire and the outer surface of the base member is indispensable for securing a sufficient flow rate of fluid by enabling fluid flowing from the gap of the wire to flow uniformly to openings of the base member. The provision of the annulus, however, causes the following problems.
In a case where plugging has occurred in a screen, an operation is made for dissolving or removing materials which have caused plugging by locally injecting liquid such as hydrochloric acid, diesel oil, light oil or surfectant under pressure in the radial direction from inside of the base member. This liquid, however, is dispersed vertically through the annulus and, as a result, a sufficient amount of liquid is not injected concentrically to the location at which the plugging has occurred and dissolving or removal of the plugging materials is not achieved to an expected degree.
In a screen of a type in which gravel is filled in a wellbore about the screen for preventing entering of sand into the screen by the filled gravel, fluid is injected towards the gravel in the radial direction from the inside of the base member when gravel is filled in the wellbore to force the gravel down by the pressure of the fluid injected. In this case also, the fluid injected is dispersed vertically through the annulus so that gravel does not move down as expected with resulting loss of uniformity in the distribution of gravel in the wellbore and reduction in the effect of preventing entering of sand into the screen.
For overcoming the above described problems, U.S. Pat. No. 4,771,829 proposes a selective isolation screen in which seal means for isolating and sealing annulus extending in the longitudinal direction defined by spacer rods of the above described type of screen are provided at selected locations in the longitudinal direction. In this screen, as shown in FIG. 6, a plurality of spacer rods b are arranged on the outer surface of a base member a consisting of a perforated pipe, a wire c is spirally wound on the outside of the spacer rods b and cylindrical sleeves e having the same radial length as the radial length of the spacer rods b are disposed inside of the wire c at selected locations at intervals in the longitudinal direction and fixed to the spacer rods b. By disposing these sleeves e which constitute the seal means at selected locations in the longitudinal direction, the annulus defined by the spacer rods and extending in the longitudinal direction is isolated and sealed in the longitudinal direction. Accordingly, in taking a step for removing plugging or filling gravel in a wellbore, fluid injected from the inside of the base member in a screen section where plugging has occurred or gravel to be forced down exists is injected radially towards the wellbore through the gap of the wire c, for the vertical flow of the fluid in the annulus is restricted by the sleeves e provided at the upper and lower locations of the screen section where the fluid is injected.
As described above, the selective isolation screen is useful for achieving effectively removal of plugging and flow down of gravel but the prior art selective isolation screen has the following problem.
In the prior art selective isolation screen, as shown in FIG. 6, the wire c is wound over the sleeves e. The wire c is normally spot-welded to the spacer rods b. Since, as is well known, spot-welding is effected by concentrating electric current at a relatively small area to heat it locally, it is extremely difficult to spot-weld the wire c to the surface of the sleeves e which have a relatively broad area as shown in FIG. 6.
Further, in the prior art selective isolation screen, the sleeves e are covered by the wire c and the gap of the wire c is normally of a very small value of about 0.3 mm and, accordingly, the sleeves e are not seen from the outside and locations and state of mounting of the sleeves e cannot be visually checked. This structure is inconvenient in that the screen has to be used without checking the state of the sleeves even if some there is defect in mounting of a sleeve.
It is, therefore, an object of the invention to overcome the above described problem of the prior art selective isolation screen and provide a method of manufacturing a selective isolation screen in which difficulty in welding work can be avoided and location and state of mounting of the sleeves can be readily checked visually.
SUMMARY OF THE INVENTION
The method achieving the above described object of the invention is a method of manufacturing a selective isolation screen which includes a base member of a generally cylindrical configuration having a plurality of openings, a plurality of spacer members extending in the longitudinal direction which are disposed, circumferentially spaced, on the outer peripheral surface of the base member, and a wire wound about the outer periphery of the spacer members with a predetermined gap, annulus defined by the spacer members and extending in the longitudinal direction being formed between the inside of the wire and the outer surface of the base member over the entire periphery of the base member, and seal means provided at selected locations in the longitudinal direction on the base member for isolating and sealing, in the longitudinal direction, the annulus defined by the spacer members and extending in the longitudinal direction, characterized in that said method comprises steps of fitting a plurality of screen jackets one by one on the base member, each of the screen jackets comprising a plurality of spacer members extending in the longitudinal direction to be disposed, circumferentially spaced, on the base member and a wire wound about the periphery of the spacer members with a predetermined gap, and welding the end portions of each screen jacket to the base member thereby fixing the screen jacket to the base member and also forming the seal means and thus constituting a single unit screen.
By fitting the screen jackets comprising spacer members and wire one by one on the base member and welding the end portions of the screen jackets to the base member, the screen jackets are fixed to the base member and also the seal means is formed between the respective seal means. Since a wire is not wound on the seal means thus formed, difficulty of welding can be avoided and location and state of mounting of the seal means can be visually checked.
Preferred embodiments of the invention will now be described with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings,
FIG. 1 is a vertical sectional view showing a part of a screen manufactured by an embodiment of the method of the invention;
FIG. 2 is a vertical sectional view showing a screen jacket used in the above embodiment;
FIG. 3 is a vertical sectional view showing a part of a screen manufactured by another embodiment of the invention;
FIG. 4 is a vertical sectional view showing a screen jacket used in this embodiment;
FIG. 5 is a vertical sectional view showing a part of a screen manufactured by still another embodiment of the invention;
FIG. 6 is a vertical sectional view showing the prior art selective isolation screen; and
FIG. 7 is a partial sectional view of another example of the welded portion.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1 and 2 show an embodiment of the method of manufacturing of a selective isolation screen according to the invention. FIG. 1 is a vertical sectional view showing a part of a screen 1 manufactured by the method of this embodiment. As a base member, a perforated pipe 3 formed with multitudes of openings 3a is used and two screen jackets 2 are fitted thereon and connected together. FIG. 2 is a vertical sectional view of each screen jacket 2.
Each screen jacket 2 is composed by winding a wire 5 with a gap d of a predetermined width on the outer periphery of spacer members 4 extending in the longitudinal direction to be disposed, circumferentially spaced, on the outer surface of the perforated pipe 3 and attaching annular sleeves 6 to the end portions of the sleeves 6. The wire 5 is spot-welded to the spacer members 4 at each crossing point with them.
This screen jacket 2 is fitted at a predetermined location on the perforated pipe 3 and then a next screen jacket 2 is likewise fitted on the perforated pipe 3. The adjacent annular sleeves 6 of the adjacent screen jackets 2 are brought into abutting engagement with each other and, if necessary, welded together whereby the respective screen jackets 2 are connected together. In this manner, the screen jackets 2 of a necessary number are fitted one by one on the perforated pipe 3 and connected to one another. Then, as shown in FIG. 1, the respective annular sleeves 6 are welded at their inner lower peripheral portions to the outer surface of the perforated pipe 3 by means of a known welding method such as TIG. The adjacent annular sleeves 6, 6 of the screen jackets 2 connected together constitute the seal means. The uppermost sleeve 6a is an endless sleeve.
FIGS. 3 and 4 show another embodiment of the method of manufacturing the screen according to the invention. FIG. 3 is a vertical sectional view of a screen 10 manufactured by using the method of this embodiment showing a state of two screen jackets 12 fitted on a perforated pipe 3. FIG. 4 is a vertical sectional view of each screen jacket 12. In FIGS. 3 and 4, the same component parts as those in FIGS. 1 and 2 are designated by the same reference characters and detailed description thereof will be omitted.
As will be apparent from FIG. 4, the screen jacket 12 used in this embodiment consists only of spacer members 4 and a wire 5 and has no annular sleeves 6 as in the screen jacket 2 used in the embodiment of FIGS. 1 and 2.
After these screen jackets 12 of a necessary number are fitted one by one on the perforated pipe 3 with a predetermined space e between adjacent screen jackets 12, the end portions 4a of the spacer members 4 are welded to the outer surface of the perforated pipe 3 by a known welding method such as TIG so as to seal off the space between the respective end portions 4a of the spacer members 4 from outside with welding material used in the welding method thereby to form a welded portion 14. Thus, by the welded portion formed at the end of each screen jacket 12, the seal means is constituted. The surface of the welded portion should preferably be formed on the same plane as the surface of the jacket. By doing so, smooth filling of gravel can be facilitated.
It is important in making a well to fill gravel uniformly in the annulus defined between the wall of the wellbore and the outer surface of the screen. If the outer surface of the screen between adjacent screen jackets 12, 12 is recessed from the surface of the screen jackets 12, 12, the gravel is sometimes not filled in this recess so that a hollow portion is produced in the gravel filled in the annulus between the wall of the wellbore and the outer surface of the screen. This hollow portion is later filled with gravel which has transferred from around the hollow portion by either pumping of oil or pressure difference in the well but this in turn tends to cause collapse of the wall of the wellbore resulting in reduction in the oil production efficiency. In the present embodiment of the invention, the surface of the welded portion 14 (or the surface of the sleeves 6 and 26 in the embodiment of FIGS. 1 and 6) is formed on the same plane as the screen jackets and, accordingly, smooth filling of gravel is ensured and occurrence of production of the hollow portion in the gravel layer can be effectively prevented.
In the conventional screen of a type in which the base member is made of a pipe formed with openings, the number of the openings is 100-180 per one foot of the screen length. In the present invention, the number of the openings of the pipe is restricted to 1-60 per one foot of the screen length. The shape of the openings may be a circle or a slot. When the shape of the openings is a circle, they should preferably have a diameter ranging from 1/16 inches to 2 inches. When the shape of the openings is a slot, they should preferably have a width ranging from 1/16 inches to 2 inches and a length ranging from 1 inch to 10 inches. This restriction of the number of openings compared with the conventional screens, together with forming of the seal means, contributes to reduction of loss of water caused by deviation of a part of water poured from above into the annulus between the wall of the wellbore and the outer surface of the screen, said deviation being produced by flow of water through the space between the spacer members inside of the wire and also flow of water into the pipe through the openings of the pipes. A sufficient flow speed of water for filling gravel to the bottom of the screen can thereby be ensured.
FIG. 5 is a view for explaining a still another embodiment of the method of manufacturing a screen according to the invention. FIG. 5 is a vertical sectional view of a screen 20 manufactured by the method of this embodiment in which two screen jackets 22 are fitted on a perforated pipe 3. In FIG. 5, the same component parts as those in FIGS. 1 and 2 are designated by the same reference characters and detailed description thereof will be omitted. Reference character 26a denotes an end sleeve.
In this embodiment, each screen jacket 22 is composed of an inner screen jacket 22a which consists of spacer members 4 and a wire 5 which are of the same construction as the screen jacket of the embodiment shown in FIG. 2 and an outer screen jacket 22b provided outside of the inner screen jacket 22a with a predetermined gap, said outer screen jacket 22b having spacer members 24 and a wire 25 wound on the outside thereof with a gap D which is larger than the gap d. Common annular sleeves 25 are fixed to the end portions of the spacer members 4 and 24 of these screen jackets 22a and 22b. The wire 25 is spot-welded to the spacer members 24 at each crossing point with them. The wire 25 is not limited to the spiral wire as shown but a plurality of rings arranged at intervals may be welded to the spacer members 24. If necessary, the gap D may be made equal to or smaller than the gap d.
Screen jackets 22 of a necessary number are fitted on the perforated pipe 3 in the same manner as in the embodiment of FIG. 1 and the annular sleeves are welded together if necessary. By welding the respective annular sleeves 26 at their inner lower edge portions to the outer surface of the perforated pipe 3 whereby the seal means is formed by the adjacent annular sleeves 26, 26 of the screen jackets 22.
In a case where the screen 20 manufactured by the method of FIG. 5 is used in a horizontal well having an horizontally extending portion or an inclined well having an obliquely extending portion along an oil layer, when this screen is pushed into a well, the outer screen jacket 22b of the screen 20 passing through a bent portion of the well is deformed by the bending of the wall surface of the well. The wire 5 of the inner screen jacket 22a does not come into contact with the wall surface of the bent portion of the well but is elastically deformed inside of the outer screen jacket 22b and thereafter is restored to the original shape after reaching the horizontal portion of the well. Since the gap is provided between the spacer members 24 of the outer screen jacket 22b and the wire 5 of the inner screen jacket 22a, adjustment can be made by properly setting this gap so that the wire 5 will not contact with the spacer members 24 when the screen passes through the bent portion of the well, or, even if the wire 5 contacts the spacer members 24, the wire 5 will not be plastically deformed under the action of excessive load. According to this embodiment, therefore, damage or deformation of the screen which tends to occur when the screen 20 forced into the well passes through the bent portion of the well can be effectively prevented and the gap d of the wire 5 of the inner screen jacket 22a can be maintained at a constant value. This double layer screen is effective also for preventing formation of sand and protecting the screen from corrosion from movement of fluid and sand.
In the above described embodiments, the perforated pipe 3 is used as the base member. The base member, however, is not limited to the perforated pipe but it may be, for example, a spiral wire extending in the axial direction of the screen. Alternatively, the base member may be composed of plural rings arranged in parallel at a predetermined interval in the axial direction of the screen so as to form slits which continue in the circumferential direction of the screen. These base members are disclosed in Japanese Patent Publication No. 32275/1983.
The base member may be a cylindrical member made by winding a spiral wire on the outside of a plurality of rods arranged in the axial direction at a predetermined interval to form a cylindrical configuration and welding the rods and wire together to form an integral cylindrical body. This type of base member is used in a double cylinder type screen disclosed by Japanese Patent Publication No. 54516/1989.
In the above described embodiments, a wedge wire is used as the wires 5 and 25. The wire however is not limited to the wedge wire but wires of other cross sections such as a rhomb, circle and square may also be used. Depending upon conditions under which the wires 5 and 25 are used, these wires 5 and 25 may be welded to a part of spacer members only instead of being welded to the spacer members at all crossing points.
The length of the seal means and the screen jackets may be suitably determined depending upon the conditions of the well. The seal means may be of a length ranging from one foot to more than half the length of the base member. It is also possible to vary the lengths of plural seal means on a single base member. The length of the screen jackets is equal to a length of a portion of the base member which is not covered with the seal means or which is not required for threading or provision of a centralizer.
In the embodiment of FIG. 3, instead of forming the welded portion 14 entirely with the welding material as illustrated, steel short cylinders 30 may be fitted on the base member between the adjacent screen jackets as shown in FIG. 7 and this short cylinder 30 may be welded with the adjacent screen jackets 12, 12 to form the welded portion 14. | A method of manufacturing a selective isolation screen includes steps of fitting a plurality of screen jackets one by one on a base member, each of the screen jackets including a plurality of spacer members extending in the longitudinal direction to be disposed, circumferentially spaced, on the base member and a wire wound about the periphery of the spacer members with a predetermined gap, and welding the end portions of each screen jacket to the base member thereby fixing the screen jacket to the base member and also forming seal means and thus constituting a single unit screen. Difficulty in welding can thereby be avoided and location and state of mounting of sleeves can be visually checked. | 1 |
FIELD OF THE INVENTION
The present invention relates to extracellular matrix molecules and nucleic acid sequences encoding them.
BACKGROUND OF THE INVENTION
The adherence of cells to each other and to the extracellular matrix, as well as the cellular signals transduced as a consequence of such binding, are of fundamental importance to the development and maintenance of body form and function. A number of molecules mediating cell adhesion have been identified and characterized at the molecular level both in vertebrates and in invertebrates. Many cell surface cell adhesion molecules (CAMs) are of three major types: 1) members of the immunoglobulin supergene family, which mediate calcium independent adhesion, 2) cadherins, which mediate calcium-dependent adhesion and are important structural components of adherence junctions, and 3) integrins, a family of heterodimeric proteins which can facilitate adhesion of cells both to each other and to the extracellular matrix.
CAMs may have multiple ligands. They can mediate adhesion by the interaction of a CAM on one cell with the identical CAM on another cell (homophilic binding), or they can mediate adhesion by interacting with different CAMs or extracellular matrix molecules (heterophilic binding). For example, contactin, a member of the immunoglobulin gene superfamily, can undergo homophilic binding or can bind heterophilically to other cell surface molecules such as the L1 antigen or to extracellular matrix molecules of the tenascin family. One extracellular matrix ligand for contactin is janusin, which is a member of the tenascin-R family. Janusin is closely related to tenascin in its patterns of epidermal growth factor, fibronectin type III and fibrinogen-like domains. In rodents, it is synthesized by oligodendrocytes and subpopulations of neurons at late developmental stages in the central nervous system. It can promote cell adhesion or anti-adhesion, depending on the neural cell type with which it interacts, promoting neurite outgrowth of some neural cell types and inhibiting neurite outgrowth from other neuronal populations. The repulsive response of neurons to janusin may be mediated by contactin. Janusin has been identified in rodents (A. Faissner. et al. 1990. J. Neurochem. 54: 1004-1015) and the rat gene has been cloned (B. Fuss, et al. 1991. Neurosci. Res. 29:299-307) and sequenced (B. Fuss, et al. 1993. J. Cell Biol. 120:1237-1249). The chicken homolog of janusin, referred to as restrictin, has also been identified and characterized (U. Norenberg, et al. 1992. Neuron 8:849-863).
SUMMARY OF THE INVENTION
Prior to the present invention, no human homolog of janusin/restrictin had been identified and it was not previously known if such a homolog existed. A human homolog of rat janusin has now been found, and the complete cDNA sequence encoding it has been determined. Antisera were prepared against a fragment of the human restrictin protein expressed in bacteria. These antibodies detect the immunogen, high molecular weight polypeptides in human brain, and cross react with several animal species. In the human brain, restrictin occurs as two major polypeptides of 180 and 160 kD located in fiber tracts. These polypeptides are similar in size to those seen in rat brain. Surprisingly, restrictin has also been found in the peripheral nerves of rats and humans. The antibodies also detect a 170 kD polypeptide in MATRIGEL, an extracellular matrix product of rat EHS sarcoma cells widely used as a tissue culture substrate. Monoclonal antibodies to human restrictin and assays using the human restrictin protein, antibodies and DNA sequences are also provided.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the cloning process used to obtain the human restrictin cDNA sequence.
DETAILED DESCRIPTION OF THE INVENTION
cDNAs encoding human restrictin were cloned from human brain polyA+ RNA using the reverse transcriptase polymerase chain reaction (RT-PCR) with primers based on the rat janusin gene sequence. RT-PCR was performed on rat and human (adult and fetal, Clontech) brain polyA+ RNA using the one-step protocol described by Goblet, et al. (1989. Nucl. Acids Res. 17:2144). PolyA+RNA (1 μg) and 300 ng of each primer (see below) in 66 μl DEPC water were incubated at 65° C. for 15 min. and cooled on ice. Thirty-three μl of 3×RT-PCR reagent mix (3× PCR buffer, 150 mM KCl, 30 mM Tris-HCl pH 8.3, 4.5 mM MgCl 2 , 0.3% gelatin, 500 μM dNTPs, 200 U M-MLV reverse transcriptase, 4 U rRNAsin (Promega, Madison, Wis.), 2.5 U AMPLITAQ (Perkin-Elmer Cetus, Norwalk, Conn.) was added and the reaction was incubated at 37° C. for 30 min. The amplification reaction (94° C. for 1 min., 50° C. for 2 min., and 72° C. for 2 min.) was repeated for 40 cycles. The primer pair for amplification was as follows:
______________________________________5'-ACTGACAGATCTAGAGCC SEQ ID NO:1 (corresponding to nucleotides 2375-2392 in rat)5'-GGTGGTCGATAGGATACT SEQ ID NO:2 (corresponding to nucleotides 2856-2839 in rat)______________________________________
A major 480 bp amplification product was obtained from rat RNA, which was subcloned and sequenced, confirming that this product corresponded to rat janusin. A minor 290 bp product was also obtained in rat. An amplification product of the appropriate size (480 bp) was also generated from human adult brain RNA. This product was subcloned and sequenced directly (Mihovilovic, 1989). Amplification of fetal RNA produced only a 290 bp amplification product which was subsequently found not to be human restrictin.
The 480 bp human amplification product (206/207N) was used as a probe on Northern blots of multiple regions of human brain (Clontech). The radiolabeled probe was prepared using a random primer labeling kit (BRL, Gaithersburg, Md.) with purification over NICK columns (Pharmacia, Piscataway, N.J.). Blots were reprobed with a human beta-actin probe (Clontech) to determine the relative amounts and integrity of RNA in each sample. The probe hybridized to a single approximately 12 Kb nucleic acid sequence in amygdala, caudate nucleus, corpus collusum, hippocampus, hypothalamus, substantia nigra, subthalamic nuclei and thalamus. The restrictin cDNA clones described below were also used as probes on northern blots of human fetal tissues. The approximately 12 Kb restrictin mRNA seen in adult brain was also detected in fetal brain, but was absent from fetal heart, lung, liver and kidney. This illustrates the tissue specificity of restrictin.
Two commercially available lambda human cDNA libraries were screened as recommended by the manufacturer using 206/207N as a probe to identify additional clones for determination of the sequence of the full-length human restrictin gene (FIG. 1). Initial screening with 206/207N identified cDNA clones 6-1 and 6-2. A second hybridization screening using a probe from the 5' end of clone 6-1, as illustrated in FIG. 1, produced cDNA clones 12 and 15. The upstream end of clone 12 was used in a third library screen to isolate clone 20. Together, these clones encode the entire protein coding region of human restrictin (FIG. 1) The lambda cDNA inserts of these clones were either 1) PCR amplified using lambda gt10 EcoRI forward and reverse primers for direct sequencing as described above (Mihovilovic, 1989), or 2) subcloned into pBLUESCRIPT (SK+) (Stratagene, La Jolla, Calif.) for sequencing by dye-termination or dye-labeled primer methods (Applied Biosystems, Model 373A, Foster City, Calif.). Sequencing primers were synthesized on an Applied Biosystems (ABI) Model 380B DNA synthesizer and purified using OPC cartridges (ABI). Sequence alignments, translations, and feature location were performed using IG-Suite software (lntelligenetics, Mountain View, Calif.). In this manner, the entire 4,724 bp human restrictin cDNA coding sequence was determined by sequencing both strands of the cDNAs (SEQ ID NO:3). The sequence of the full-length restrictin protein (1358 amino acids, SEQ ID NO:4) was deduced from the cDNA sequence. The human restrictin protein shows structural similarity to other members of the tenascin-R family. In particular, human restrictin, like its homologs from rat and chicken, comprises a short amino terminal region followed by heptad repeats, epidermal growth factor-like repeats, nine fibronectin type III repeats and a carboxyl-terminal region homologous to the globular domain of fibrinogen. There is no evidence for a hydrophobic membrane spanning region, consistent with restrictin being a secreted, extracellular matrix molecule. The human sequence obtained is highly homologous to the rat and chicken sequences at both the DNA (88 and 76%, respectively, within the protein coding region) and at the amino acid level (93 and 72%, respectively).
SEQ ID NO:3, a fragment of SEQ ID NO:3, or an equivalent nucleic acid molecule which employs degenerate codons to encode the amino acid sequence of SEQ ID NO:4 or a fragment thereof, may be cloned into an expression vector as is known in the art to produce recombinant human restrictin in transformed or transfected host cells. Recombinant human restrictin and recombinant human restrictin fragments provide a convenient source of these molecules for immunization, immunoassays, and use in tissue culture growth substrates. To generate antisera to human restrictin, the 206/207N fragment (nucleotides 2686-3165 of SEQ ID NO:3 with EcoRI cloning sites at both the 5' and 3+ ends) was subcloned into the EcoRI site of pGEX-3X (Pharmacia), producing a recombinant human restrictin-glutathione-S-transferase (GST) fusion protein for immunization. After transformation of E. coli, expression of the fusion protein was induced with IPTG and the soluble material was purified over a glutathione-S Sepharose affinity column. The purified material was used to immunize rabbits using standard methods. Sera were collected and assayed by immunoblotting against the immunogen and against the 206/207N protein fragment, expressed by subcloning into the pATH expression system (New England BioLabs). The anti-fusion protein antisera recognized both of these antigens on Western blots, but anti-chicken restrictin did not, indicating immunological differences between the human and chicken restrictin proteins.
To verify the reactivity of the antisera against human proteins, adult brain membranes were prepared and extracted. In brief, postsmortem human brain was Dounce homogenized into 0.32M sucrose, 5 mM EDTA, 20 mM Tris-HCl (pH 8) containing 1 mM PMSF, 0.5 mM p-chloromercuriphenylsulfonic acid and 5 μg/ml of aprotinin and leupeptin as protease inhibitors. After centrifugation at 500×g for 30 min. to remove nuclei and cellular debris, the supernatant was centrifuged at 80,000×g to collect the membrane fraction, which was then extracted with I% sodium deoxycholate in homogenization buffer for 1.5 hr. at 4° C. The detergent extract was clarified by centrifugation at 100,000×g and used subsequently for either SDS-PAGE directly or for further purification of a protein fraction bearing the HNK-1 epitope, which may be involved in binding cell adhesion molecules. HNK-I brain fractions were immunoaffinity enriched on anti-Leu7 (Becton Dickinson) coupled to Sepharose. Immunoblotting was performed using a PROTOBLOT AP system (Promega) as recommended by the manufacturer with an alkaline phosphatase-conjugated anti-rabbit IgG as the secondary antibody and color development using NBT/BCIP. In Western blots, the anti-fusion protein antisera routinely detected two bands of approximately 180 and 160 kD in human brain and in HNK-1 enriched fractions. These bands were apparently enriched in the latter. The reactivity of the antisera was inhibited in a concentration dependent manner by addition of the GST fusion protein, but not by addition of GST, indicating a specific immune reaction to the human restrictin fragment. Western blots of rat, mouse, cow, pig and chicken brain extracts demonstrated similar sized bands (180 kD and 160 kD) in all cases. There were, however, slight mobility shifts, possibly due to species variation in amino acid sequence or to differential glycosylation. MATRIGEL (Collaborative Biomedical Products), an extracellular matrix substrate derived from rat EHS sarcoma cells as an in vitro tissue culture growth substrate, was also reactive with the antiserum, revealing a 170 kD polypeptide.
For immunohistological studies, frozen human or rat tissues were sectioned and fixed using acetone or 4% paraformaldehyde. Staining was performed using the VECTA-STAIN ELITE ABC system (Vector Laboratories) as recommended. Primary anti-fusion protein antisera were used at a 1:1000 dilution. Paraffin sections were treated using the microwave antigen retrieval system (U.S. Pat. No. 5,244,787) before staining. The antisera were reactive with frozen sections of human peripheral nerve (peripheral nervous system), rat hippocampus (central nervous system) and human cerebellum (central nervous system) and with paraffin section human pons (central nervous system). In all cases, there were areas of clear positivity as well as areas that were clearly negative. For example, in the peripheral nerve experiments, the surrounding, non-neuronal tissue was unstained, and in the central nervous system, there were clearly unstained cells in all areas examined.
Antibodies according to the invention which recognize human restrictin are useful in methods for detecting the protein in immunoassay systems. Polyclonal antisera raised to human restrictin or to protein fragment of human restrictin may be used to detect the restrictin protein in immunoassay methods involving binding between the protein or fragment and the antibodies, e.g., ELISAs and immunoblots. These conventional immunoassay methods can be readily adapted to employ the antibodies and restrictin protein disclosed herein. Alternatively, monoclonal antibodies which recognize the human restrictin protein of the invention may be prepared using methods known in the art, such as that of Kohler and Milstein (1975. Nature 256:495) and used in immunoassays. The spleen cells of mice immunized with the human restrictin protein or a fragment thereof are fused with murine myeloma cells and the resulting hybridomas are screened against the immunogen to select those producing the desired anti-restrictin monoclonal antibody. In general, binding between protein and antibody in an immunoassay is detected by inclusion of a detectable label in the reaction which generates a signal. The detectable label is usually conjugated to the antibody or protein and may be directly detectable (e.g., a dye, radioisotope or fluorochrome) or rendered detectable after further chemical reaction (e.g., an enzyme which reacts to produce a colored product, or biotin which may be bound to labeled avidin).
Polyclonal and monoclonal antibodies according to the invention may also be used to purify human restrictin from tissues, or to purify restrictin from the tissues of a cross-reacting species by immunoaffinity purification methods, e.g., immunoaffinity chromatography. This provides a source of natural restrictin for use in immunoassays, as an immunogen, or in tissue culture systems to promote or inhibit neurite outgrowth.
Oligonucleotides derived from the nucleotide sequences encoding human restrictin are useful in nucleic acid hybridization assays for detection of related restrictin nucleotide sequences. They may also be used as primers for amplification of restrictin target sequences. Oligonucleotide probes for hybridization according to the invention may comprise the complete coding sequence of the human restrictin cDNA or a portion thereof, such as nucleotides 2686-3165 of SEQ ID NO:3. Primers are generally short portions of the nucleotide sequence which specifically hybridize to restrictin nucleotide sequences, allowing specific amplification. One skilled in the art will further recognize that oligonucleotide probes and primers may also be designed which comprise all or a portion of a sequence which is complementary to SEQ ID NO:3. Detection of nucleic acids by hybridization to a probe is known in the art. Such methods as Southern blotting, Northern blotting, dot blotting, nucleic acid amplification methods and the like may be readily adapted to detection of nucleotide sequences containing all or part of the human restrictin coding sequence, or to detection of all or part of the restrictin coding sequence of a cross-reacting species. This is done using the nucleotide sequence given in SEQ ID NO:3 to design appropriate probes and primers. For purposes of the present invention, the terms "encoding" and "coding for" are intended to include nucleic acids which comprise sequences which can be transcribed and/or translated to produce restrictin, or a fragment thereof, including degenerate nucleotide sequences. It will also be understood that probes and primers derived from the disclosed nucleotide sequences may also be used to detect fragments of restrictin coding sequences. Hybridization of the probe or amplification by the primers may be detected by means of a directly or indirectly detectable label associated with the probe or primer, i.e., incorporated into the probe or conjugated to it. In general, the same labels useful for labeling antibodies and antigens may be used to label oligonucleotides. In addition, it is within the ordinary skill in the art, given the nucleotide sequence of SEQ ID NO:3. to derive the complementary nucleotide sequence, which may also be used to prepare probes and primers and which may be detected by use of probes and primers. Further, the present disclosure of SEQ ID NO:3 allows derivation of RNA sequences which are complementary to SEQ ID NO:3 or to the complement of SEQ ID NO:3. Such equivalent RNA sequences may be detected by hybridization or amplification as well.
The reagents for performing these immunoassays, hybridization assays, and nucleic acid amplification may be conveniently packaged together for sale or use in the form of a kit. A kit for immunoassay may contain an antibody which recognizes and binds to restrictin. The antibody may be labeled, or a second antibody carrying the label may be included for detection of binding. Optionally, any reagent required for performing the assay and detecting the label may be included. A kit for hybridization assays or amplification may contain oligonucleotide probes or primers which hybridize to one or more nucleotide sequences contained in SEQ ID NO:3. The probes or primers may be conjugated to a detectable label for detection. Optionally, the hybridization or amplification kit may contain any reagents required for performing the hybridization or amplification and detecting the label.
The foregoing disclosure is intended to illustrate the invention and is not to be construed as limiting its scope as defined by the appended claims. Upon reading the present disclosure, certain equivalents and variations will be apparent to one skilled in the art without exercise of inventive skill. Such equivalents and variations are intended to be included within the scope of the invention.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 4(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 18 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:ACTGACAGATCTAGAGCC18(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 18 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:GGTGGTCGATAGGATACT18(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 4724 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:GAATTCCGGGAGAAGGGGGTCCTCTCTGACCCAAGGAATTACCACTAGTGGAGTGAAGCC60ACCTGACTTTTTGATCTTATTTTGGTTGCCTCCTCATTCTCCTTCCACCCGTAGCCCTGA120CAGCTTGGGTTTCATTTCTTTCGTGGAGCCTTGTCTCTTCCTCCCAGAATAGGAGGAAGG180GAAGAGAAGGGAAAGAGGAGGGCTCTCTAGGTGAGCGCATCAGCTGGCTCCAGCCTGAGC240AAGCAAGAATTTTCTTCCCAGGAAGCTCCTCTCGCTCCCCGGCCGCCCACCCCCAGCCTG300GGTGGCTGTATCGTTTTAACTGCATAGAGGGCAGGTCTCTTTTGGAATTAGGATTAAAGA360AAGTGCAGTAAAGAGAAAGCATCGAAGACACCATCACAAAAGATTCCCACAACTCCATGC420TGTGTGCTGCAGGCTGGTCCTGAACCCAGATCTCTGGCTGAGAGGATGGGGGCAGATGGG480GAAACAGTGGTTCTGAAGAACATGCTCATTGGCGTCAACCTGATCCTTCTGGGCTCCATG540ATCAAGCCTTCAGAGTGTCAGCTGGAGGTCACCACAGAAAGGGTCCAGAGACAGTCAGTG600GAGGAGGAGGGAGGCATTGCCAACTACAACACGTCCAGCAAAGAGCAGCCTGTGGTCTTC660AACCACGTGTACAACATTAACGTGCCCTTGGACAACCTCTGCTCCTCAGGGCTAGAGGCC720TCTGCTGAGCAGGAGGTGAGTGCAGAAGACGAGACTCTGGCAGAGTACATGGGCCAGACC780TCAGACCACGAGAGCCAGGTCACCTTTACACACAGGATCAACTTCCCCAAAAAGGCCTGT840CCATGTTCCAGTTCAGCCCAGGTGCTGCAGGAGCTGCTGAGCCGGATCGAGATGCTGGAG900AGGGAGGTGTCGGTGCTGCGAGACCAGTGCAACGCCAACTGCTGCCAAGAAAGTGCTGCC960ACAGGACAACTGGACTATATCCCTCACTGCAGTGGCCACGGCAACTTTAGCTTTGAGTCC1020TGTGGCTGCATCTGCAACGAAGGCTGGTTTGGCAAGAATTGCTCGGAGCCCTACTGCCCG1080CTGGGTTGCTCCAGCCGGGGGGTGTGTGTGGATGGCCAGTGCATCTGTGACAGCGAGTAC1140AGCGGGGATGACTGTTCCGAACTCCGGTGCCCAACAGACTGCAGCTCCCGGGGGCTCTGC1200GTGGACGGGGAGTGTGTCTGTGAAGAGCCCTACACTGGCGAGGACTGCAGGGAACTGAGG1260TGCCCTGGGGACTGTTCGGGGAAGGGGAGATGTGCCACCGGTACCTGTTTATGCGAGGAG1320GGCTACGTTGGTGAGGACTGCGGCCAGCGGCAGTGTCTGAATGCCTGCAGTGGGCGAGGA1380CAATGTGAGGAGGGGCTCTGCGTCTGTGAAGAGGGCTACCAGGGCCCTGACTGCTCAGCA1440GTTGCCCCTCCAGAGGACTTGCGAGTGGCTGGTATCAGCGACAGGTCCATTGAGCTGGAA1500TGGGACGGGCCGATGGCAGTGACGGAATATGTGATCTCTTACCAGCCGACGGCCCTGGGG1560GGCCTCCAGCTCCAGCAGCGGGTGCCTGGAGATTGGAGTGGTGTCACCATCACGGAGCTG1620GAGCCAGGTCTCACCTACAACATCAGCGTCTACGCTGTCATTAGCAACATCCTCAGCCTT1680CCCATCACTGCCAAGGTGGCCACCCATCTCTCCACTCCTCAAGGGCTACAATTTAAGACG1740ATCACAGAGACCACCGTGGAGGTGCAGTGGGAGCCCTTCTCATTTTCCTTCGATGGGTGG1800GAAATCAGCTTCATTCCAAAGAACAATGAAGGGGGAGTGATTGCTCAGGTCCCCAGCGAT1860GTTACGTCCTTTAACCAGACAGGACTAAAGCCTGGGGAGGAATACATTGTCAATGTGGTG1920GCTCTGAAAGAACAGGCCCGCAGCCCCCCTACCTCGGCCAGCGTCTCCACAGTCATTGAC1980GGCCCCACGCAGATCCTGGTTCGCGATGTCTCGGACACTGTGGCTTTTGTGGAGTGGATT2040CCCCCTCGAGCCAAAGTCGATTTCATTCTTTTGAAATATGGCCTGGTGGGCGGGGAAGGT2100GGGAGGACCACCTTCCGGCTGCAGCCTCCCCTGAGCCAATACTCAGTGCAGGCCCTGCGG2160CCTGGCTCCCGATACGAGGTGTCAGTCAGTGCCGTCCGAGGGACCAACGAGAGCGATTCT2220GCCACCACTCAGTTCACAACAGAGATCGATGCCCCCAAGAACTTGCGAGTTGGTTCTCGC2280ACAGCAACCAGCCTTGACCTCGAGTGGGATAACAGTGAAGCCGAAGTTCAGGAGTACAAG2340GTTGTGTACAGCACCCTGGCGGGTGAGCAATATCATGAGGTACTGGTCCCCAAGGGCATT2400GGTCCAACCACCAGGGCCACCCTGACAGATCTGGTACCTGGCACTGAGTATGGAGTTGGA2460ATATCTGCCGTCATGAACTCACAGCAAAGCGTGCCAGCCACCATGAATGCCAGGACTGAA2520CTTGACAGTCCCCGAGACCTCATGGTGACAGCCTCCTCAGAGACCTCCATCTCCCTCATC2580TGGACCAAGGCCAGTGGCCCCATTGACCACTACCGAATTACCTTTACCCCATCCTCTGGG2640ATTGCCTCAGAAGTCACCGTACCCAAGGACAGGACCTCATACACACTAACAGATCTAGAG2700CCTGGGGCAGAGTACATCATTTCCGTCACTGCTGAGAGGGGTCGGCAGCAGAGCTTGGAG2760TCCACTGTGGATGCTTTCACAGGCTTCCGTCCCATCTCTCATCTGCACTTTTCTCATGTG2820ACCTCCTCCAGTGTGAACATCACTTGGAGTGATCCATCTCCCCCAGCAGACAGACTCATT2880CTTAACTACAGCCCCAGGGATGAGGAGGAAGAGATGATGGAGGTCTCCCTGGATGCCACC2940AAGAGGCATGCTGTCCTGATGGGCCTGCAACCAGCCACAGAGTATATTGTGAACCTTGTG3000GCTGTCCATGGCACAGTGACCTCTGAGCCCATTGTGGGCTCCATCACCACAGGAATTGAT3060CCCCCAAAAGACATCACAATTAGCAATGTGACCAAGGACTCAGTGATGGTCTCCTGGAGC3120CCTCCTGTTGCATCTTTCGATTACTACCGAGTATCATATCGACCCACCCAAGTGGGACGA3180CTAGACAGCTCAGTGGTGCCCAACACTGTGACAGAATTCACCATCACCAGACTGAACCCA3240GCTACCGAATACGAAATCAGCCTCAACAGCGTGCGGGGCAGGGAGGAAAGCGAGCGCATC3300TGTACTCTTGTGCACACAGCCATGGACAACCCTGTGGATCTGATTGCTACCAATATCACT3360CCAACAGAAGCCCTGCTGCAGTGGAAGGCACCAGTGGGTGAGGTGGAGAACTACGTCATT3420GTTCTTACACACTTTGCAGTCGCTGGAGAGACCATCCTTGTTGACGGAGTCAGTGAGGAA3480TTTCGGCTTGTTGACCTGCTTCCTAGCACCCACTATACTGCCACCATGTATGCCACCAAT3540GGACCTCTCACCAGTGGCACCATCAGCACCAACTTTTCTACTCTCCTGGACCCTCCGGCA3600AACCTGACAGCCAGTGAAGTCACCAGACAAAGTGCCCTGATCTCCTGGCAGCCTCCCAGG3660GCAGAGATTGAAAATTATGTCTTGACCTACAAATCCACCGACGGAAGCCGCAAGGAGCTG3720ATTGTGGATGCAGAAGACACCTGGATTCGACTGGAGGGCCTGTTGGAGAACACAGACTAC3780ACGGTGCTCCTGCAGGCAACACAGGACACCACGTGGAGCAGCATCACCTCCACCGCTTTC3840ACCACAGGAGGCCGGGTGTTCCCTCATCCCCAAGACTGTGCCCAGCATTTGATGAATGGA3900GACACTTTGAGTGGGGTTTACCCCATCTTCCTCAATGGGGAGCTGAGCCAGAAATTACAA3960GTGTACTGTGATATGACCACCGACGGGGGCGGCTGGATTGTATTCCAGAGGCGGCAGAAT4020GGCCAAACTGATTTTTTCCGGAAATGGGCTGATTACCGTGTTGGCTTCGGGAACGTGGAG4080GATGAGTTCTGGCTGGGGCTGGACAATATACACAGGATCACATCCCAGGGCCGCTATGAG4140CTGCGCGTGGACATGCGGGATGGCCAGGAGGCCGCCTTCGCCTCCTACGACAGGTTCTCT4200GTCGAGGACAGCAGAAACCTGTACAAACTCCGCATAGGAAGCTACAACGGCACTGCGGGG4260GACTCCCTCAGCTATCATCAAGGACGCCCTTTCTCCACAGAGGATAGAGACAATGATGTT4320GCAGTGACTAACTGTGCCATGTCGTACAAGGGAGCATGGTGGTATAAGAACTGCCACCGG4380ACCAACCTCAATGGGAAGTACGGGGAGTCCAGGCACAGTCAGGGCATCAACTGGTACCAT4440TGGAAAGGCCATGAGTTCTCCATCCCCTTTGTGGAAATGAAGATGCGCCCCTACAACCAC4500CGTCTCATGGCAGGGAGAAAACGGCAGTCCTTACAGTTCTGAGCAGTGGGCGGCTGCAAG4560CCAACCAATATTTTCTGTCATTTGTTTGTATTTTATAATATGAAACAAGGGGGGAGGGTA4620ATAGCAATGTTTTTTGCAACATATTAAGAGTATGTNAAGGAAGCAGGGATGTCGCAGGAA4680TCCGCTGGCTAACATCTGCTCTNGGTTTCTGCTGNCCTGGAGGC4724(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1358 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:MetGlyAlaAspGlyGluThrValValLeuLysAsnMetLeuIleGly151015ValAsnLeuIleLeuLeuGlySerMetIleLysProSerGluCysGln202530LeuGluValThrThrGluArgValGlnArgGlnSerValGluGluGlu354045GlyGlyIleAlaAsnTyrAsnThrSerSerLysGluGlnProValVal505560PheAsnHisValTyrAsnIleAsnValProLeuAspAsnLeuCysSer65707580SerGlyLeuGluAlaSerAlaGluGlnGluValSerAlaGluAspGlu859095ThrLeuAlaGluTyrMetGlyGlnThrSerAspHisGluSerGlnVal100105110ThrPheThrHisArgIleAsnPheProLysLysAlaCysProCysSer115120125SerSerAlaGlnValLeuGlnGluLeuLeuSerArgIleGluMetLeu130135140GluArgGluValSerValLeuArgAspGlnCysAsnAlaAsnCysCys145150155160GlnGluSerAlaAlaThrGlyGlnLeuAspTyrIleProHisCysSer165170175GlyHisGlyAsnPheSerPheGluSerCysGlyCysIleCysAsnGlu180185190GlyTrpPheGlyLysAsnCysSerGluProTyrCysProLeuGlyCys195200205SerSerArgGlyValCysValAspGlyGlnCysIleCysAspSerGlu210215220TyrSerGlyAspAspCysSerGluLeuArgCysProThrAspCysSer225230235240SerArgGlyLeuCysValAspGlyGluCysValCysGluGluProTyr245250255ThrGlyGluAspCysArgGluLeuArgCysProGlyAspCysSerGly260265270LysGlyArgCysAlaThrGlyThrCysLeuCysGluGluGlyTyrVal275280285GlyGluAspCysGlyGlnArgGlnCysLeuAsnAlaCysSerGlyArg290295300GlyGlnCysGluGluGlyLeuCysValCysGluGluGlyTyrGlnGly305310315320ProAspCysSerAlaValAlaProProGluAspLeuArgValAlaGly325330335IleSerAspArgSerIleGluLeuGluTrpAspGlyProMetAlaVal340345350ThrGluTyrValIleSerTyrGlnProThrAlaLeuGlyGlyLeuGln355360365LeuGlnGlnArgValProGlyAspTrpSerGlyValThrIleThrGlu370375380LeuGluProGlyLeuThrTyrAsnIleSerValTyrAlaValIleSer385390395400AsnIleLeuSerLeuProIleThrAlaLysValAlaThrHisLeuSer405410415ThrProGlnGlyLeuGlnPheLysThrIleThrGluThrThrValGlu420425430ValGlnTrpGluProPheSerPheSerPheAspGlyTrpGluIleSer435440445PheIleProLysAsnAsnGluGlyGlyValIleAlaGlnValProSer450455460AspValThrSerPheAsnGlnThrGlyLeuLysProGlyGluGluTyr465470475480IleValAsnValValAlaLeuLysGluGlnAlaArgSerProProThr485490495SerAlaSerValSerThrValIleAspGlyProThrGlnIleLeuVal500505510ArgAspValSerAspThrValAlaPheValGluTrpIleProProArg515520525AlaLysValAspPheIleLeuLeuLysTyrGlyLeuValGlyGlyGlu530535540GlyGlyArgThrThrPheArgLeuGlnProProLeuSerGlnTyrSer545550555560ValGlnAlaLeuArgProGlySerArgTyrGluValSerValSerAla565570575ValArgGlyThrAsnGluSerAspSerAlaThrThrGlnPheThrThr580585590GluIleAspAlaProLysAsnLeuArgValGlySerArgThrAlaThr595600605SerLeuAspLeuGluTrpAspAsnSerGluAlaGluValGlnGluTyr610615620LysValValTyrSerThrLeuAlaGlyGluGlnTyrHisGluValLeu625630635640ValProLysGlyIleGlyProThrThrArgAlaThrLeuThrAspLeu645650655ValProGlyThrGluTyrGlyValGlyIleSerAlaValMetAsnSer660665670GlnGlnSerValProAlaThrMetAsnAlaArgThrGluLeuAspSer675680685ProArgAspLeuMetValThrAlaSerSerGluThrSerIleSerLeu690695700IleTrpThrLysAlaSerGlyProIleAspHisTyrArgIleThrPhe705710715720ThrProSerSerGlyIleAlaSerGluValThrValProLysAspArg725730735ThrSerTyrThrLeuThrAspLeuGluProGlyAlaGluTyrIleIle740745750SerValThrAlaGluArgGlyArgGlnGlnSerLeuGluSerThrVal755760765AspAlaPheThrGlyPheArgProIleSerHisLeuHisPheSerHis770775780ValThrSerSerSerValAsnIleThrTrpSerAspProSerProPro785790795800AlaAspArgLeuIleLeuAsnTyrSerProArgAspGluGluGluGlu805810815MetMetGluValSerLeuAspAlaThrLysArgHisAlaValLeuMet820825830GlyLeuGlnProAlaThrGluTyrIleValAsnLeuValAlaValHis835840845GlyThrValThrSerGluProIleValGlySerIleThrThrGlyIle850855860AspProProLysAspIleThrIleSerAsnValThrLysAspSerVal865870875880MetValSerTrpSerProProValAlaSerPheAspTyrTyrArgVal885890895SerTyrArgProThrGlnValGlyArgLeuAspSerSerValValPro900905910AsnThrValThrGluPheThrIleThrArgLeuAsnProAlaThrGlu915920925TyrGluIleSerLeuAsnSerValArgGlyArgGluGluSerGluArg930935940IleCysThrLeuValHisThrAlaMetAspAsnProValAspLeuIle945950955960AlaThrAsnIleThrProThrGluAlaLeuLeuGlnTrpLysAlaPro965970975ValGlyGluValGluAsnTyrValIleValLeuThrHisPheAlaVal980985990AlaGlyGluThrIleLeuValAspGlyValSerGluGluPheArgLeu99510001005ValAspLeuLeuProSerThrHisTyrThrAlaThrMetTyrAlaThr101010151020AsnGlyProLeuThrSerGlyThrIleSerThrAsnPheSerThrLeu1025103010351040LeuAspProProAlaAsnLeuThrAlaSerGluValThrArgGlnSer104510501055AlaLeuIleSerTrpGlnProProArgAlaGluIleGluAsnTyrVal106010651070LeuThrTyrLysSerThrAspGlySerArgLysGluLeuIleValAsp107510801085AlaGluAspThrTrpIleArgLeuGluGlyLeuLeuGluAsnThrAsp109010951100TyrThrValLeuLeuGlnAlaThrGlnAspThrThrTrpSerSerIle1105111011151120ThrSerThrAlaPheThrThrGlyGlyArgValPheProHisProGln112511301135AspCysAlaGlnHisLeuMetAsnGlyAspThrLeuSerGlyValTyr114011451150ProIlePheLeuAsnGlyGluLeuSerGlnLysLeuGlnValTyrCys115511601165AspMetThrThrAspGlyGlyGlyTrpIleValPheGlnArgArgGln117011751180AsnGlyGlnThrAspPhePheArgLysTrpAlaAspTyrArgValGly1185119011951200PheGlyAsnValGluAspGluPheTrpLeuGlyLeuAspAsnIleHis120512101215ArgIleThrSerGlnGlyArgTyrGluLeuArgValAspMetArgAsp122012251230GlyGlnGluAlaAlaPheAlaSerTyrAspArgPheSerValGluAsp123512401245SerArgAsnLeuTyrLysLeuArgIleGlySerTyrAsnGlyThrAla125012551260GlyAspSerLeuSerTyrHisGlnGlyArgProPheSerThrGluAsp1265127012751280ArgAspAsnAspValAlaValThrAsnCysAlaMetSerTyrLysGly128512901295AlaTrpTrpTyrLysAsnCysHisArgThrAsnLeuAsnGlyLysTyr130013051310GlyGluSerArgHisSerGlnGlyIleAsnTrpTyrHisTrpLysGly131513201325HisGluPheSerIleProPheValGluMetLysMetArgProTyrAsn133013351340HisArgLeuMetAlaGlyArgLysArgGlnSerLeuGlnPhe134513501355__________________________________________________________________________ | Human restrictin proteins and nucleic acid sequences encoding them are provided. Antibodies which recognize human restrictin in human brain are disclosed. In the human brain, restrictin occurs as two major polypeptides of 180 and 160 kD located in fiber tracts. These polypeptides are similar to those seen in rat brain. Surprisingly, restrictin has also been found in the peripheral nerves of rats and humans. The antibodies also detect a 170 kD polypeptide in MATRIGEL, an extracellular matrix product of rat EHS sarcoma cells widely used as a tissue culture substrate. Monoclonal antibodies to human restrictin and assays using the human restrictin protein, antibodies and DNA sequences are also provided. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/876,650 filed on Dec. 22, 2006 which application is incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to improvements in apparatus for transmitting force between a rotary driving unit (such as the engine of a motor vehicle) and a rotary driven unit (such as the variable-speed transmission in the motor vehicle). In particular, the invention relates to a method of controlling a clutch located between an engine and an impeller for a torque converter to enable turbo charge spool up during a vehicle launch event.
BACKGROUND OF THE INVENTION
Turbochargers are used in vehicle engines to increase the power output of the engine without increasing the size of the engine, specifically, the cylinder displacement. That is, a turbocharger can significantly improve the power-to-weight ratio for the engine. A turbocharger uses the exhaust flow from the engine to spin a turbine, which in turn spins an air pump. The turbine in the turbocharger spins at speeds of up to 150,000 rotations per minute. Power increases of 30 to 40 percent are typical for turbocharged engines.
Unfortunately, turbochargers do not provide an immediate power boost during a launch event. A time period, typically measured in seconds or fractions of seconds is needed for the turbine to reach the speeds necessary to produce the desired boost. This phenomenon, known as “turbo-lag,” results in a hesitation at the start of a launch event. It is known to decrease turbo-lag by reducing the inertia of the rotating parts in the turbocharger, mainly by reducing the weight of the parts. This weight reduction enables the turbine and compressor to accelerate more quickly, and start providing boost earlier. Inertia can be reduced by reducing the size of the turbocharger. Unfortunately, a smaller turbocharger may not be able to provide adequate boost at higher engine speeds. Also, a smaller turbocharger may rotate at excessive speeds.
For turbocharged engines in vehicles with torque converters, it is known to use a “loose” torque converter. This arrangement allows the engine to attain higher speeds during the launch event, decreasing the time necessary for the turbocharger to reach the desired speed. Unfortunately, this configuration results in a decrease in fuel economy across the entire operating range of the torque converter.
Thus, there is a long-felt need for a means to reduce turbo-lag without compromising fuel economy or the performance of the turbocharger.
BRIEF SUMMARY OF THE INVENTION
The present invention broadly comprises a method of operating a clutch during a vehicle launch including the steps of increasing a first hydraulic pressure in an inner chamber from a first level to a second level, and decreasing a second hydraulic pressure in an outer chamber from a third level to a fourth level as a function of a speed for the engine. The first hydraulic pressure urges, to an engaged position, a clutch disposed between an engine in the vehicle and an impeller for a torque converter in the vehicle and the second hydraulic pressure opposes the first hydraulic pressure. In some aspects, the method includes decreasing the second hydraulic pressure in the outer chamber as a function of a throttle position for the engine. The method slips the clutch in response to decreasing the second pressure.
In some aspects, decreasing the second hydraulic pressure includes decreasing the second pressure as a function of oil temperature in the transmission. In some aspects, the first level is equal to a maximum operating pressure for the outer chamber, is at least 50% greater than the third pressure, is at least twice the third pressure, or is at least triple the third pressure. In some aspects, the method compares the function of the engine speed with a threshold value and maintains the first pressure at the first level if the function is greater than the threshold value. In some aspects, the method compares the function of the engine speed with a threshold value and increases the first pressure to the second level if the function is less than or equal to the threshold value. In some aspects, the method compares the engine speed to a launch threshold value and if the engine speed is greater than the launch threshold value bypasses the function of engine speed to decrease the third level to the fourth level.
In some aspects, the vehicle comprises a valve controlling hydraulic pressure in the outer chamber and a zero percent duty cycle fully opens the valve. The method includes comparing the engine speed to a launch threshold value and, when the engine speed is greater than the launch threshold value, applying the zero percent duty cycle to the valve. In some aspects, the vehicle comprises a valve controlling hydraulic pressure in the outer chamber and a duty cycle controls an operating position for the valve. Then the method includes comparing the engine speed to a launch threshold value and, when the engine speed is less than or equal to the launch threshold value, determining the duty cycle as a function of the engine speed and applying the duty cycle to the valve. In some aspects, the method modifies the duty cycle as a function of oil temperature in the transmission.
In some aspects, the clutch and the first and second chambers are disposed in the torque converter. In some aspects, the torque converter comprises a cover, an output hub, and a torque converter clutch, and the torque converter clutch provides a torque transmission path between the cover and the output hub. In some aspects, the method maintains the engine speed below a predetermined level. In some aspects, the method determines an optimal engine speed to provide a peak torque for a determined throttle position and fully engages the clutch when the engine reaches the optimal engine speed.
It is a general object of the present invention to provide a method of controlling a clutch during a vehicle launch that enables an increase in engine speed, turbo spool up, and available engine torque during the launch event.
These and other objects and advantages of the present invention will be readily appreciable from the following description of preferred embodiments of the invention and from the accompanying drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing figures, in which:
FIG. 1 is a schematic diagram of a clutch system for use with a present invention method of operating a torque converter during vehicle launch;
FIG. 2 is a graph showing control of hydraulic pressure in outer and inner chambers according to a present invention method of operating a torque converter during vehicle launch; and,
FIG. 3 is a flow chart of a present invention method.
DETAILED DESCRIPTION OF THE INVENTION
At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred aspects, it is to be understood that the invention as claimed is not limited to the disclosed aspects.
Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described.
FIG. 1 is a schematic diagram of clutch system 100 for use with present a invention method of operating a torque converter during vehicle launch. System 100 includes impeller clutch, or disconnect clutch 102 between engine 103 for a vehicle (not shown) and impeller 104 for torque converter 105 . Clutch 102 is connected to pump cover 106 . Impeller 104 is fluidly coupled to turbine 107 , which is connected to turbine shell 108 . Shell 108 is connected to output hub 109 . Typically the impeller clutch is operated by manipulating respective hydraulic pressures in two chambers. To engage the impeller clutch, pressure in one chamber is increased and pressure in the other chamber is decreased. For example, pressure in inner chamber 110 is increased and pressure in outer chamber 112 is decreased. That is, there is a positive pressure differential across the clutch between the inner and outer chambers.
In some aspects, clutch 102 includes piston plate 114 , which hydraulically separates the chambers. The plate is displaceable in response to pressures in the chambers. For example, increasing pressure in the inner chamber and decreasing pressure in the outer chamber cause the plate to move such that the clutch engages. It should be understood that the configuration shown in FIG. 1 is for purposes illustration only and that a clutch system for use with a present invention method is not limited to the configuration shown. For example, any impeller clutch known in the art and using two chambers can be used with a present invention method.
The torque capacity of the impeller clutch depends on the pressure differential between the inner and outer chambers. As the differential increases, the torque capacity also increases. The impeller clutch slips if the torque applied to the clutch is greater than the torque capacity associated with the pressure differential for the clutch at the time the torque is applied.
The inner chamber is connected to inner pressure line 118 to supply fluid to the chamber and the outer chamber is connected to outer pressure line 120 to enable discharge of fluid from the chamber. In some aspects, valve 122 and valve 124 are placed in the inner and outer lines, respectively, to control fluid flow through the lines. In some aspects, the valves are solenoid valves. The inner and outer valves are used to control pressure in the respective chambers, and hence, the differential pressure across plate 114 .
Valves 122 and 124 can be controlled by any means known in the art. In some aspects, system 100 includes controller 126 , used to send pulse width modulation (PWM) signals 128 and 130 , respectively, to valves 122 and 124 , for the control of the valves, as described infra.
Clutch 102 is modulated (allowed to slip) during a launch event for the vehicle such that the engine speed is greater than the rotational speed of impeller 104 . That is, the slippage of the clutch enables the engine to rotate faster than the impeller. In accordance with a present invention method, the clutch is closed at an appropriate point in time to synchronize the rotation of the engine and impeller. During the entire launch sequence, torque is transmitted through clutch 102 to eliminate a delay between the launch time expected by a driver of the vehicle and the actual vehicle launch. The constant transfer of torque also eliminates shock that could occur from engaging the clutch when there is a large amount of torque produced by the engine and the difference of rotational speed between the engine and the torque converter is relatively great.
Pressure in chambers 110 and 112 are controlled as functions of the engine speed or as functions of the engine speed and a position for accelerator pedal 132 or a throttle (not shown). In some aspects, an open loop control scheme is used in which the respective values of the PWM signals are determined based upon engine speed. That is, the signals are a function of the engine speed. In some aspects, the signals also are a function of the position of pedal 132 or the throttle. In some aspects, the controller derives a correction value for the control signals to account for the viscosity changes in transmission fluid due to temperature changes in the transmission. Any means known in the art can be used to determine the fluid temperature, for example, sensor 134 . The control signals designate duty cycles for the respective valves. For example, a 100% duty cycle fully closes the valve and a 0% duty cycle fully opens the valve. In some aspects, controller 126 includes respective look-up tables (not shown) to derive signals 128 and 130 . The tables provide a matrix with throttle position and engine speed as the row and column parameters.
FIG. 2 is a graph showing control of hydraulic pressure in outer and inner chambers according to a present invention method of operating a torque converter during vehicle launch. At beginning 136 of a launch event, the clutch is disengaged, level 138 for pressure 140 in the outer chamber is relatively high and level 142 for pressure 144 in the inner chamber is relatively low. In some aspects, pressure 140 is 50% higher than pressure 144 , double pressure 144 , or triple pressure 144 . In some aspects, the pressure in the outer chamber is at or near the maximum operating pressure for the chamber and the pressure in the inner chamber is at or near the minimum operating pressure for the chamber.
At point 146 , the launch event begins. In some aspects, pressure 144 is quickly raised to level 147 and is maintained at this level. Level 147 is the maximum engagement pressure that is applied to plate 114 . At point 148 , the inner chamber is applying maximum pressure to engage the clutch, but the outer chamber is still applying maximum pressure to oppose the engagement of the clutch. Therefore, there is relatively little apply pressure on the clutch and the clutch slipping is at a maximum.
At point 148 , the engine speed, throttle position, and oil temperature are used to generate signal 130 which causes valve 124 to open and pressure 140 to drop. The slope of segment 150 depends on the engine speed, throttle position, and oil temperature. In general, the higher the engine speed and throttle position, the steeper the ramp. During segment 150 , clutch 102 continues to slip, but the amount of slippage decreases as pressure 140 decreases.
At point 152 , pressure 140 reaches minimum level 154 and clutch 102 is fully engaged. That is, clutch 102 ceases to slip. It should be understood that clutch 102 may stop slipping at some other point closer to point 148 . At point 152 , pressures 140 and 144 are determined such that clutch 102 has a desire torque capacity.
In some aspects (not shown), at point 136 , pressure 140 is quickly decreased and pressure 144 is slowly increased in response to signal 128 . That is, the manipulation of the pressures is the reverse of that shown in FIG. 2 .
FIGS. 1 and 2 are with respect to a launch event for a diesel engine equipped with a turbocharger. However, it should be understood that the present invention is not limited to diesel engines and that the use of the present invention with other types of turbocharged engines is included in the spirit and scope of the invention as claimed. By launch event we mean putting in motion a vehicle fully or substantially at rest or putting in forward motion a vehicle on an upwardly slanted slope (from back to front of the vehicle) and experiencing a force in the reverse direction.
In some aspects, a multi-function torque converter (MFTC) is used with the present invention method. An MFTC is described in U.S. Pat. No. 6,494,303, “TORSIONAL VIBRATION DAMPER FOR A TORQUE TRANSMITTING APPARATUS,” issued Dec. 17, 2002 and incorporated herein by reference. However, it should be understood that the present invention method can be applied to any MFTC known in the art or to any torque converter employing a clutch between the torsional input to the converter and a pump for the converter and that such application is included in the spirit and scope of the invention as claimed.
FIG. 3 is a flow chart of present invention method 200 . Although method 200 in FIG. 3 is depicted as a sequence of numbered steps for clarity, no order should be inferred from the numbering unless explicitly stated. The steps are referenced with respect to system 100 , however, it should be understood that method 200 is not limited to use with system 100 and that method 200 is applicable to any system with an impeller clutch. The method starts at step 202 . Step 204 detects a launch situation. Step 206 compares the engine speed to a threshold value. If the speed is greater than the threshold value, step 207 sets control signals 128 and 130 so that valves 122 and 124 are unenergized, which places torque converter 105 in torque converter mode and bypasses the remainder of the method. That is, chamber 110 is rapidly charged (similar to what is shown in FIG. 2 ) and chamber 112 is rapidly exhausted. In general, the rate of discharge for chamber 112 is more rapid than would be the case if the pressure in the chamber were reduced as a function of the engine speed. Then the method proceeds to step 220 , the end of the method.
If step 206 determines that the engine speed is less or equal to the threshold, step 208 generates signal 130 as a function of engine speed and throttle position. Step 210 determines a transmission oil temperature factor as a function of the oil temperature and step 212 modifies signal 130 using the oil temperature factor. Then step 214 compares signal 130 to a threshold regarding valve 122 . If the signal is above the threshold, which corresponds to the pressure in chamber 112 being above a certain level, step 215 keeps valve 122 closed and chamber 110 is not charged. The method then proceeds to step 218 . That is, unlike the scheme described in FIG. 2 , the method does not automatically “flip” the pressure in chamber 110 when a launch situation is detected. If signal 130 is less than or equal to the threshold, step 216 opens valve 122 to charge chamber 110 and then the method proceeds to step 218 .
Step 218 compares the signal for valve 124 to a final or fully open value. If the valve is not yet fully opened, the method returns to step 206 . If the valve is fully opened, the clutch is fully engaged and the method terminates.
Thus, it is seen that the objects of the present invention are efficiently obtained, although modifications and changes to the invention should be readily apparent to those having ordinary skill in the art, which modifications are intended to be within the spirit and scope of the invention as claimed. It also is understood that the foregoing description is illustrative of the present invention and should not be considered as limiting. Therefore, other embodiments of the present invention are possible without departing from the spirit and scope of the present invention. | A method of operating a clutch during vehicle launch including increasing a first hydraulic pressure in an inner chamber from a first to a second level; decreasing a second hydraulic pressure in an outer chamber from a third to a fourth level in response to engine speed and throttle position for the vehicle; and slipping the clutch in response to increasing and decreasing the first and second pressures, respectively. The first hydraulic pressure urges a clutch disposed between the engine and an impeller for a vehicle torque converter to an engaged position. The second hydraulic pressure opposes the first hydraulic pressure. In some aspects, the method includes determining a temperature for oil in a transmission in the vehicle. Then, decreasing the second hydraulic pressure includes decreasing the second pressure in response to the determined temperature. In some aspects, the clutch and the chambers are located in the torque converter. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to electric lighting systems, and more particularly pertains to a direct current lighting system utilizable in a dwelling.
2. Description of the Prior Art
The present invention is a variation upon a European lighting system which uses open cables for power and metal rods to conduct the power to a halogen lamp. The non-insulated cables are strung tightly across the ceiling of a room in parallel and are electrified with twelve volts of D.C. power. One cable is positive and the other is negative. Metal rods are draped over these cables, making contact and transferring the power to the halogen lamp.
Because the system is twelve volts D.C. and connected to an insulated, fuse connected invertor, the chances of electric shock are eliminated. The power flowing through the cables is much like that of a toy train set wherein one track is positive and the other is negative.
To produce such a system in the United States would require the cables and metal rods to be insulated to U.S. standards. Even though non-insulated systems are in operation all over Europe in homes and offices, U.S. standards do not allow such systems to be sold commercially.
As such, there appears to be a need for such a system in the United States provided that each of the various components could be designed to satisfy U.S. standards while providing an aesthetic appearance close to that of its European counterpart. In this respect, the present invention substantially fulfills this need.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of D.C. current lighting systems now present in the prior art, the present invention provides an improved D.C. lighting system construction wherein the same has been designed to meet U.S. standards so as to become commercially available in the United States. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved D.C. powered lighting system which has all the advantages of the prior art D.C. lighting systems and none of the disadvantages.
To attain this, the present invention essentially comprises a lighting system which uses stretched insulated cables for power with such cables also operating as the supports for a plurality of lamps. The insulated cables are tightly strung in parallel across the ceiling of a room and are provided with twelve volts of D.C. power. One cable is positive and the other is negative, and a pair of cable clamps are then attached to each of the cables with the cable clamps supporting a direct current lamp assembly. A plurality of lamps can be strung in parallel to the cables and adjustable positioning is available through use of the quick release cable clamps.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
It is therefore an object of the present invention to provide a new and improved D.C. powered lighting system which has all the advantages of the prior art D.C. powered lighting systems and none of the disadvantages.
It is another object of the present invention to provide a new and improved D.C. powered lighting system which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new and improved D.C. powered lighting system which is of a durable and reliable construction.
An even further object of the present invention is to provide a new and improved D.C. powered lighting system which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such D.C. powered lighting systems economically available to the buying public.
Still yet another object of the present invention is to provide a new and improved D.C. powered lighting system which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
Still another object of the present invention is to provide a new and improved D.C. powered lighting system which is designed to conform to United States standards so as to facilitate a commercial availability in the United States.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is perspective view of the lighting system embodying the principles and concepts of the present invention.
FIG. 2 is a perspective view of a cable clamp forming a part of the present invention.
FIG. 3 is a cross-sectional view of the cable clamp as viewed along the line 3--3 in FIG. 2.
FIG. 4 is a perspective view of the lower jaw portion of the cable clamp.
FIG. 5 is a perspective view of the lower jaw portion showing the main spring attached thereto.
FIG. 6 is a perspective view of the lower jaw portion showing the contact wire and restraining slide attached thereto.
FIG. 7 is a perspective view of the main body of the cable clamp.
FIG. 8 is a bottom perspective view of the main body.
FIG. 9 is an electrical diagram of the electric circuit used in the present invention.
FIG. 10 is a front elevation view illustrating the completed assembly which forms the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular to FIG. 1 thereof, a new and improved D.C. powered lighting system embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described.
More specifically, it will be noted that the lighting system 10 essentially consists of an invertor 12 which converts alternating current to direct current, with direct current being supplied to two strung cables 14, 16 as illustrated. One of the cables 14, 16 is positive and the other cable is negative whereby a completed electrical circuit is established when contact is made between the two power supply cables. One or more halogen lamps 18 are strung from the power cables 14, 16 by means of a pair of rods 20, 22 having respective cable clamps 24, 26 attached to ends thereof. Appropriate contact wires in the cable clamps 24, 26 establish electric contact with the wires 14, 16 and direct such power down through electrical conductors retained within the hollow tubes 20, 22. All of this structure will be subsequently described in greater detail.
With continuing reference to FIG. 1 of the drawings, the insulated cables 14, 16 used in this invention comprise standard 5 millimeter insulated cable available almost anywhere in the United States. It is most often seen as three millimeter braided galvanized steel coated cable coated with one millimeter of clear plastic. The load strength of the cable is 340 pounds.
Remote ends 28, 30 of the respective cables 14, 16 are completely insulated and looped permanently. These ends 28, 30 represent the far ends of the cable and are at a maximum distance from the invertor 12. A pair of eye bolts 32, 34 are attached to a far wall 36, and the cable loops 28, 30 are attached respectively to these eye bolts by small turn buckles to allow adjustment of the tension. The complete length of each cable 14, 16 needs to be enough to reach from the far end wall 36 to the near end wall 38 and down to the invertor 12.
Each cable 14, 16 is attached to the near end wall 38 in much the same manner of the far end wall 36. Eye bolts 40, 42 are attached to the wall 38, and these eye bolts include small turn buckles for tension adjustment; however, the shape of the loops in the cable depend upon the placement of the invertor 12. If the invertor is directly beneath the near ends of the cables 14, 16, each cable could be twisted to form a loop and a small clamp could be used to hold the cables on the turn buckles. If the power source 12 is behind the near wall 38, loops would again be formed in the cables 14, 16 and a clamp would anchor the loops with the cables then extending inwardly through apertures in the wall and down to the invertor.
In FIG. 1, it can be seen that the two cables 14, 16 are strung in this described manner and are paralleledly aligned to each other. The cables 14, 16 can however be made to go in a variety of directions using other eye bolts screwed into ceilings or walls. They can run virtually anywhere as long as they run parallel.
Once the contact portion of the cables 14, 16 has been strung, the near ends thereof are attached to the invertor 12, and the cables remain insulated until they enter the invertor box. There they are solidly attached to their respective poles.
Different effects can be achieved by using differently colored insulation on the cables, either clear or opaque. Clear plastic is the basic color scheme but solid black, opaque, red, blue or any other color combination that comes to mind will change the overall effect. As such, the halo cable system can be matched to any interior.
A power supply which provides the power to operate the halo cable system is supplied by a precision regulated D.C. powered supply. Known as a rectifier, it converts the standard 120 volt, 60 cycle alternating current into 12 volt direct current power at an ampere level in accordance with the rectifier's abilities. The higher the ampere output of the rectifier, the greater the number of lights can be run from it. With an ampere rating of 4.5, the rectifier will be able to light two 20 watt bulbs or one 50 watt bulb. In order to light five 20 watt bulbs on one system, the rectifier will have to have an output of at least 8.4 amperes. If the system has too many lights, the rectifier will exceed its ampere rating and shut down until the excess energy drain is removed.
The rectifier 12 can be installed in view or hidden behind a wall as long as it not far from the insulated cables 14, 16. Most commercial units have a switch on the body of the rectifier allowing the user to turn the power flow on and off; however, direct wiring to a light switch is much more convenient. The insulated cables 14, 16 enter the rectifier casing 12 where they are stripped and attached to their respective poles making contact with the power. A locking device or childproof latch keeps the rectifier case closed from prying hands even though chances of electric shock are minimal. The basic electric circuit as above-discussed is shown in FIG. 9.
The primary purpose of the lamp fixture 18, as illustrated in FIG. 1 and also in FIG. 10, is to act as a support to which a halogen lamp is attached and receives power. The fixture 18 is suspended from the insulated cable by two sets of cable clamps 24, 26 as aforementioned in combination with the respective hollow rods 20, 22.
The fixture 18 holds the light in place beneath it with metallic clamps embedded in an insulated plastic. These clamps also send the power directly to the post of the lamp. The plastic in which the clamps are embedded hinges with the larger plastic sides of the main body so as to allow the lamp to be angled up to 90 degrees to either side. Power is brought to the light through insulated wires carried down the hollow rods 20, 22 which are connected to the main body 18. These hollow rods 20, 22 are fastened to the main body at hinge points allowing further angling of the light.
As above-explained, the two hollow rods 20, 22 needed for each light carry the insulated wire from the respective cable clamps 24, 26 down to the lamp fixture 18. One rod 20 carries the positive wire while the other carries the negative wire. Once the wire is strung through, the rods 20, 22 are permanently attached to the cable clamps 24, 26 and the lamp fixture 18. The rods 20, 22 need to be heavy enough to support the lamp fixture 18 suspended below, yet not so heavy whereby the insulated cables 14, 16 will be bowed down by excess weight. A good example would be antenna rod used on radio receivers.
The length of the rods is determined before assembly. They can be of almost any length from two inches to two feet depending upon the desires of the user. The longer the rods 20, 22, the lower the light will drop below or rise above the insulated cables 14, 16. The distance the cables 14, 16 are apart also determines the final amount of rise or fall of the light fixture 18. FIG. 10 of the drawings illustrates the integration of the hallow rods 20, 22 into the system 10.
With reference to FIGS. 2-8 of the drawings, a complete description of one of the cable clamps 24, 26 will be provided. The purpose of each cable clamp 24, 26 is to pierce the insulation on the cables 14, 16 and make contact with the power flowing through them. The power is taken from the cables 14, 16 and sent down the afore-described insulated wire to the halogen lamp.
Cable clamps 24, 26 are identical in structure and include a main body 44, a lower jaw 46 attached to the main body by a hinge pin 48, a cable contact pin 50, and a contact pin slide 52. Additionally, each clamp includes a restraining slide 54, a restraining slide spring 56, a main spring 58, a body support 60, a rod connection 62, and an insulated wire 64 directed down to the halogen light.
Using tension from the main spring 58 rising through its middle, the cable clamp 24, 26 pinches the insulated cable 14, 16 between its jaws. This same spring tension allows the contact pin 50 to pierce the insulated casing on each cable 14, 16 and make contact with the power beneath. A pin 50 is held back from piercing a cable casing until it is released by the restraining slide 54. The power from the cable 14, 16 is transferred through the contact pin 50 down the wire 64 which emerges from the bottom of the cable clamp 24, 26, and threads through one of the hollow rods 20, 22 to the fixture 18 below.
The contact pin slide 52 holds the contact pin 5 and the contact wire 64. The slide moves within the main body 60 lengthwise allowing the pin to pierce the cable coating and making contact with power. The movement is provided by the afore-described main spring 58 being contracted and released. This movement allows the pin 50 to be extracted and inserted into the cable casing whenever necessary.
The restraining slide 54 moves vertically (orthogonally to the contact pin slide 52), and its purpose is to keep the contact pin 50 from penetrating the cable casing until released. When the main spring 58 is contracted, the restraining slide 54 moves up, blocking the movement of the contact pin slide 52. The upward movement is provided by the restraining slide spring 56. When depressed, the restraining slide 54 moves downward allowing the contact pin slide 52 to pass through its middle without hinderance.
The main body 60 contains many hollow spaces to facilitate the movement of the various interior components. It keeps the components together as one type package, and construction is simplified by creating two almost identical halves and affixing them together once the slides 52, 54 and spring 58 are inserted.
The lower jaw 46 is attached to the main body 60 by the hinge pin 48. Its purpose is to clamp the insulated cable 14, 16 between itself and the main body 60 by leveraging the tension from the main spring 58. The lower jaw 46 fits neatly to the bottom of the main body 60.
As illustrated, the main spring 58 is one piece of heavy gauge spring wire, with the upper portion shaped in a circle to provide a pad to be compressed by a user's fingers. The lower section lies flush with the lower jaw 46 and is compressed along with the upper section. The main vertical shaft rises through the contact pin slide and when the spring 58 is compressed, the slide 52 moves to the rear of the main body 60 and then to the front of the main body upon release.
As to the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A lighting system uses stretched insulated cables for power with such cables also operating as the supports for a plurality of lamps. The insulated cables are tightly strung in parallel across the ceiling of a room and are provided with twelve volts of D.C. power. One cable is positive and the other is negative, and a pair of cable clamps are then attached to each of the cables with the cable clamps supporting a direct current lamp assembly. A plurality of lamps can be strung in parallel to the cables and adjustable positioning is available through use of the quick release cable clamps. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No. 13/505,474, filed Jun. 20, 2012, which the US National Stage of International Application No. PCT/EP2010/066714, filed Nov. 3, 2010, which International Application claims priority to Great Britain Application No. 0919430.9 filed Nov. 5, 2009, and Great Britain Application No. 1002974.2, filed Feb. 22, 2010, where the contents of each of the preceding are herein incorporated by reference in their entireties.
FIELD OF THE INVENTION
The present invention relates to a process for the identification of small molecules which inhibit the binding of the first and second bromodomains (BD1 and 2, also known as the N- and C-terminal bromodomains) of the human BET family proteins BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins, pharmaceutical compositions containing such compounds and to their use in therapy.
BACKGROUND OF THE INVENTION
The genomes of eukaryotic organisms are highly organised within the nucleus of the cell. The long strands of duplex DNA are wrapped around an octomer of histone proteins (most usually comprising two copies of histones H2A, H2B H3 and H4) to form a nucleosome. This basic unit is then further compressed by the aggregation and folding of nucleosomes to form a highly condensed chromatin structure. A range of different states of condensation are possible, and the tightness of this structure varies during the cell cycle, being most compact during the process of cell division. Chromatin structure plays a critical role in regulating gene transcription, which cannot occur efficiently from highly condensed chromatin. The chromatin structure is controlled by a series of post translational modifications to histone proteins, notably histones H3 and H4, and most commonly within the histone tails which extend beyond the core nucleosome structure. These modifications include acetylation, methylation, phosphorylation, ubiquitinylation, SUMOylation. These epigenetic marks are written and erased by specific enzymes, which place the tags on specific residues within the histone tail, thereby forming an epigenetic code, which is then interpreted by the cell to allow gene specific regulation of chromatin structure and thereby transcription.
Histone acetylation is most usually associated with the activation of gene transcription, as the modification loosens the interaction of the DNA and the histone octomer by changing the electrostatics. In addition to this physical change, specific proteins bind to acetylated lysine residues within histones to read the epigenetic code. Bromodomains are small (˜110 amino acid) distinct domains within proteins that bind to acetylated lysine residues commonly but not exclusively in the context of histones. There are a family of around 50 proteins known to contain bromodomains, and they have a range of functions within the cell.
The BET family of bromodomain containing proteins comprises 4 proteins (BRD-2, BRD-3, BRD-4 and BRD-t) which contain tandem bromodomains (BD1 and 2) capable of binding to two acetylated lysine residues in close proximity, increasing the specificity of the interaction. BRD-2 and BRD-3 are reported to associate with histones along actively transcribed genes and may be involved in facilitating transcriptional elongation (Leroy et al, Mol. Cell. 2008 30(1):51-60), while BRD-4 appears to be involved in the recruitment of the pTEF-B complex to inducible genes, resulting in phosphorylation of RNA polymerase and increased transcriptional output (Hargreaves et al, Cell, 2009 138(1): 129-145). It has also been reported that BRD4 or BRD3 may fuse with NUT (nuclear protein in testis) forming novel fusion oncogenes, BRD4-NUT or BRD3-NUT, in a highly malignant form of epithelial neoplasia (French et al. Cancer Research, 2003, 63, 304-307 and French et al. Journal of Clinical Oncology, 2004, 22 (20), 4135-4139). Data suggests that BRD-NUT fusion proteins contribute to carcinogensesis (Oncogene, 2008, 27, 2237-2242). BRD-t is uniquely expressed in the testes and ovary. All family members have been reported to have some function in controlling or executing aspects of the cell cycle, and have been shown to remain in complex with chromosomes during cell division—suggesting a role in the maintenance of epigenetic memory. In addition some viruses make use of these proteins to tether their genomes to the host cell chromatin, as part of the process of viral replication (You et al Cell, 2004 117(3):349-60).
Umehara et al have solved the X-ray crystal structure for human BRD-2 BD1 when bound to a histone acetylated lysine residue (Protein crystallographic databank entry 2dvq) and demonstrated that the acetylated lysine residue accepts a hydrogen bond from the sidechain NH2 group of ASN 156 and also accepts a hydrogen bond from a water molecule that is itself hydrogen-bonded to the sidechain hydroxyl of TYR113. They have also predicted the amino acid residues which define the acetyl lysine recognition pocket of the first bromodomain (BD1) of human BRD-2 (JP2008-156311, The Institute of Physical and Chemical Research (RIKEN)). We have now identified small molecules which inhibit the binding of BD1 and 2 of the human BET family proteins BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins. X-ray crystal studies of these molecules when bound to these BET bromodomains have allowed us to retrospectively identify the key binding sites involved in this interaction. This information can be used in the rational drug design of further small molecules which are able to inhibit the binding of the first and/or second bromodomains of human BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins.
SUMMARY OF THE INVENTION
In a first aspect of the present invention, there is provided a process for the identification of small molecules, in particular compounds with a molecular weight in the range 100 to 750, which inhibit the binding of the first and/or second bromodomains of human BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins which comprises selecting those compounds which are able to:
a) form a hydrogen bonding interaction in which the compound accepts a hydrogen bond from the sidechain NH2 group of the asparagine residue found at:
BRD-2 BRD-2 BRD-3 BRD-3 BRD-4 BD1 BD2 BD1 BD2 BD1 BRD-4 BD2 ASN156 ASN429 ASN116 ASN391 ASN140 ASN433
or
b) accept a water-mediated hydrogen bond in which the compound accepts a hydrogen bond from a water that is itself hydrogen-bonded to the sidechain hydroxyl of the tyrosine residue found at
BRD-2 BRD-2 BRD-3 BRD-3 BD1 BD2 BD1 BD2 BRD-4 BD1 BRD-4 BD2 TYR113 TYR386 TYR73 TYR348 TYR97 TYR390
and
c) which are also able to form a Van der Waals interaction with a lipophilic binding region of a binding pocket such that one or more heavy atoms of the said compounds lie within a 5 Å range of any of the heavy atoms of the following bromodomain residues which define the binding pocket:
BRD-2
BRD-2
BRD-3
BRD-3
BRD-4
BD1
BD2
BD1
BD2
BD1
BRD-4 BD2
TRP97
TRP370
TRP57
TRP332
TRP81
TRP374
PRO98
PRO371
PRO58
PRO333
PRO82
PRO375
ASP161
ASP434
ASP121
GLU396
ASP145
GLU438
ILE162
VAL435
ILE122
VAL397
ILE146
VAL439
MET165
MET438
MET125
MET400
MET149
MET442
From a comparison of the amino acid sequences of the human BET family bromodomains ( FIG. 1 ) a person skilled in the art will appreciate that the residues shown in Table 1 are equivalent. This may also be seen by comparison of the published crystal structures of the BRD-2, BRD-3 and BRD-4 bromodomains, which have all been solved. See Nakamura et al. (J. Biol. Chem. 2007, 282, 4193-4201) for a description of the BRD-2 D1 bromodomain structure, and also protein crystallographic databank entries for BRD-2 D1 (1x0j, 2cvq, 2drv, 2dvs, 2dvq), BRD-2 D2 (2dvv, 2e3k), BRD-3 D1 (2nxb), BRD-3 D2 (2oo1), BRD-4 D1 (2oss) and BRD-4 D2 (2ouo, 2dww).
TABLE 1
BRD-2 BD1
BRD-2 BD2
BRD-3 BD1
BRD-3 BD2
BRD-4 BD1
BRD-4 BD2
a
TRP97
TRP370
TRP57
TRP332
TRP81
TRP374
b
PRO98
PRO371
PRO58
PRO333
PRO82
PRO375
c
TYR113
TYR386
TYR73
TYR348
TYR97
TYR390
d
ASN156
ASN429
ASN116
ASN391
ASN140
ASN433
e
ASP161
ASP434
ASP121
GLU396
ASP145
GLU438
f
ILE162
VAL435
ILE122
VAL397
ILE146
VAL439
g
MET165
MET438
MET125
MET400
MET149
MET442
In a second aspect of the present invention, there is provided a pharmaceutical composition comprising a compound identified according to the above process, or a pharmaceutically acceptable salt or solvate thereof, and one or more pharmaceutically acceptable carriers, diluents and excipients.
In a third aspect of the present invention, there is provided a compound identified according to the above process, or a pharmaceutically acceptable salt or solvate thereof, for use in therapy, in particular in the treatment of diseases or conditions for which a bromodomain inhibitor is indicated.
In a fourth aspect of the present invention, there is provided a method of treating diseases or conditions for which a bromodomain inhibitor is indicated in a subject in need thereof which comprises administering a therapeutically effective amount of a compound identified according to the above process, or a pharmaceutically acceptable salt or solvate thereof.
In a fifth aspect of the present invention, there is provided the use of a compound identified according to the above process, or a pharmaceutically acceptable salt or solvate thereof, in the manufacture of a medicament for the treatment of diseases or conditions for which a bromodomain inhibitor is indicated.
BRIEF DESCRIPTION OF FIGURES
FIG. 1 : Sequence alignment of the human BRD-2, BRD-3 and BRD-4 bromodomains. The bromodomains have been extracted from the sequences and aligned to each other. The first residue in each line is numbered according to the entry in the Swissprot sequence database (entries P25440, BRD-2_HUMAN; Q15059, BRD-3_HUMAN; O60885, BRD-4_HUMAN). Key residues are labelled below: a=Trp97, b=Pro98, c=Tyr113, d=Asn156, e=Asp161, f=Ile162, g=Met165 (BRD-2 D1 residues and numbering). As shown, position a is a conserved tryptophan; position b is a conserved proline; position c is a conserved tyrosine; position d is a conserved asparagine; position e is aspartic acid or glutamic acid; position f is isoleucine or valine, and position g is a conserved methionine.
SEQ ID NO: 1 is BRD-2_D1
SEQ ID NO: 2 is BRD-3_D1
SEQ ID NO: 3 is BRD-4_D1
SEQ ID NO: 4 is BRD-2_D2
SEQ ID NO: 5 is BRD-3_D2
SEQ ID NO: 6 is BRD-4_D2
FIG. 2 : Depiction of compound (I) when bound to BRD-2 BD1.
FIG. 3 : Depiction of compound (I) when bound to BRD-4 BD1.
FIG. 4 : Depiction of compound (I) when bound to BRD-4 BD2.
FIG. 5 : Depiction of compound (II) when bound to BRD-2 BD1.
FIG. 6 : Depiction of compound (II) when bound to BRD-2 BD2.
FIG. 7 : Overlay of X-ray crystal structures of compounds (I) (depicted as ball+stick) and (II) (depicted as stick) when bound to BRD-2 BD1 showing the compounds accepting a hydrogen bond from the sidechain NH2 of ASN156 and forming a Van der Waals interaction with a lipophilic region within the binding pocket formed by the residues TRP97, PRO98, ASP161, ILE 162 and MET165 (indicated by a dotted circle).
FIG. 8 : Overlay of X-ray crystal structures of compound (I) (depicted as ball+stick) when bound to BRD-4 BD2 and compound (II) (depicted as stick) when bound to BRD-2 BD2 showing the compounds accepting a hydrogen bond from a water molecule that was itself hydrogen-bonded to the sidechain hydroxyl of the tyrosine residue found at position 386 of BRD-2 BD2 or the equivalent 390 position of BRD-4 BD2, and forming a Van der Waals interaction with a lipophilic region within the binding pocket formed by the residues TRP370, PRO371, ASP434, VAL435 and MET438 in BRD-2 BD2 or the equivalent residues TRP374, PRO375, GLU438, VAL439 and MET442 in BRD-4 BD2 (indicated by the dotted circle).
FIG. 9 : Depiction of compound (III) when bound to BRD-2 BD1.
FIG. 10 : Depiction of compound (IV) when bound to BRD-2 BD1.
FIG. 11 : Overlay of X-ray crystal structures of compounds (II) (depicted as ball+stick) and (IV) (depicted as stick) when bound to BRD-2 BD1 showing the compounds accepting a hydrogen bond from the sidechain NH2 of ASN156 and forming a Van der Waals interaction with a lipophilic region within the binding pocket formed by the residues TRP97, PRO98, ASP161, ILE 162 and MET165 (indicated by a dotted circle).
DETAILED DESCRIPTION OF THE INVENTION
A small group of molecules which were shown by classical pharmacological techniques to have an interesting but unexplained anti-inflammatory biological profile were shown through subsequent chemoproetomic studies to bind to the bromodomain regions of the human BET family proteins.
Thus, novel compounds which belong to two different structural classes have been identified which inhibit the binding of the first and/or second bromodomains of human BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins (hereinafter referred to as bromodomain inhibitors). Examples of these bromodomain inhibitors include:
When assessed in a Fluorescence Anisotropy Binding Assay both compounds (I) and (II) above demonstrated a pIC50≧6.0 in each of the BRD-2, BRD-3 and BRD-4 assays.
Analysis of X-ray crystal structures of these bromodomain inhibitors when bound to these BET bromodomains have allowed us to identify the key binding sites involved in this interaction.
In particular. X-ray crystal structures were obtained for compound (I) when bound to BRD-2 BD1, BRD-4 BD1 and BRD-4 BD2, and for compound (II) when bound to BRD-2 BD1 and 2. These are given in each of FIGS. 2 to 6 below.
Comparison of these crystal structures indicated that the structurally unrelated compounds (I) and (II) interact with the key acetylated lysine binding pocket of BRD-2 and 4 in the same way, mimicking the hydrogen-bonding network normally made by the acetylated lysine moiety of histone peptides within this pocket. One interaction was with a sidechain NH2 group of an asparagine residue. Compounds (I) and (II) also interacted with a sidechain hydroxyl of a tyrosine residue via an intermediate water molecule. For example, both compounds (I) and (II) accepted a hydrogen bond from the sidechain NH2 group of the asparagine residue found at the 156 position in BRD-2 BD 1 (see FIGS. 2, 5 and 7 ). Both compounds (I) and (II) also accepted a hydrogen bond from a water molecule that was itself hydrogen-bonded to the sidechain hydroxyl of the tyrosine residue found at the 390 position of BRD-4 BD2 and the equivalent 386 position of BRD-2 BD2 (see FIGS. 4, 6 and 8 ).
Further comparison between the different crystal structures obtained led to the identification of a third conserved interaction between the structurally unrelated compounds (I) and (II) and the human proteins BRD-2 and 4. Compounds (I) and (II) were each found to interact with a further binding pocket formed partly by residues of the ZA loop of the bromodomain protein, and partly by residues found at the N-terminal end of the 60 C helix (see Nakamura et al., J. Biol. Chem. 2007, 282, 4193-4201 for definitions). The identity of these residues in each bromodomain are as listed in Table 2.
TABLE 2
Residues corresponding to the binding pocket
BRD-2
BRD-2
BRD-3
BRD-3
BRD-4
BD1
BD2
BD1
BD2
BD1
BRD-4 BD2
TRP97
TRP370
TRP57
TRP332
TRP81
TRP374
PRO98
PRO371
PRO58
PRO333
PRO82
PRO375
ASP161
ASP434
ASP121
GLU396
ASP145
GLU438
ILE162
VAL435
ILE122
VAL397
ILE146
VAL439
MET165
MET438
MET125
MET400
MET149
MET442
For example, both compounds (I) and (II) formed a Van der Waals interaction with a lipophilic region within this binding pocket wherein one or more heavy atoms of the compound lay within a 5 Å range of any of the heavy atoms of the bromodomain residues TRP97, PRO98, ASP161, ILE 162 or MET165 of BRD-2 BD1 (see FIG. 7 ).
In particular, both compounds (I) and (II) formed a Van der Waals interaction with a lipophilic region within this binding pocket wherein one or more heavy atoms of the compound lay within 7.5 Å of at least one heavy atom of each of PRO98, ASP161 and ILE162 of BRD-2 BD1 (see FIG. 7 ).
It was noteworthy that this interaction was not observed in the crystal structure of the histone acetylated lysine residue when bound to human BRD-2 BD1. However, surprisingly, interaction with this further binding pocket appears to be of particular importance in conferring activity. Compound (III) set out below shows a marked reduction in pIC50 when assessed in the Fluorescence Anisotropy Binding Assay for the binding of BRD-2 to 4 when compared with compound (II).
When assessed in a Fluorescence Anisotropy Binding Assay compound (III) above demonstrated a pIC50≦4.3 in each of the BRD-2, BRD-3 and BRD-4 assays. % Inhibition at 200 μM compound concentration of 34%, 46% and 45% was seen in the BRD-2 to 4 assays respectively, indicating that binding was occurring but at a low level. This is in contrast to compound (II) which demonstrated a pIC50≧6.5 in each of the BRD-2, BRD-3 and BRD-4 assays.
The crystal structure of compound (III) bound to BRD-2 BD1 indicates that the compound accepts a hydrogen bond from the sidechain NH2 group of the asparagine residue found at the 156 position in BRD-2 BD 1. Compound (III) also accepts a hydrogen bond from a water that is itself hydrogen-bonded to the sidechain hydroxyl of the tyrosine residue found at the 113 position in BRD-2 BD1. However, there is no interaction with the binding pocket containing the residues tryptophan, proline, asparagine, isoleucine and methionine (see FIG. 9 ). Addition of the pendant 4-chloroaniline group, as seen in compound (II), allows interaction with the binding pocket, in addition to the acetylated lysine binding pocket as shown in FIGS. 5 and 7 .
Compound (IV) is a further novel bromodomain inhibitor, which when assessed in a Fluorescence Anisotropy Binding Assay demonstrated a pIC50>6.0 in each of the BRD-2, BRD-3 and BRD-4 assays.
The crystal structure of compound (IV) when bound to BRD-2 BD1 indicates that, like each of the compounds (I) to (III), the compound accepts a hydrogen bond from the sidechain NH2 group of the asparagine residue found at the 156 position in BRD-2 BD1 and also accepts a hydrogen bond from a water that is itself hydrogen-bonded to the sidechain hydroxyl of the tyrosine residue found at the 113 position in BRD-2 BD1 (see FIG. 10 ).
Further comparison of the X-ray crystal structures of compounds (II) and (IV) when bound to BRD-2 BD1 shows that the key Van der Waals interaction with a lipophilic region within the binding pocket defined by the residues set out in Table 2 was conserved even though the 4-chloroaniline substituent had been replaced with an isopropyl carbamate moiety (see FIG. 11 ).
From a comparison of the amino acid sequences of the human BET family bromodomains ( FIG. 1 ) a person skilled in the art will appreciate that the residues shown in Table 1 are equivalent. This may also be seen by comparison of the published crystal structures of the BRD-2, BRD-3 and BRD-4 bromodomains, which have all been solved. See Nakamura et al. (J. Biol. Chem. 2007, 282, 4193-4201) for a description of the BRD-2 D1 bromodomain structure, and also protein crystallographic databank entries for BRD-2 D1 (1x0j, 2cvq, 2drv, 2dvs), BRD-2 D2 (2dvv, 2e3k), BRD-3 D1 (2nxb), BRD-3 D2 (2oo1), BRD-4 D1 (2oss) and BRD-4 D2 (2ouo, 2dww).
TABLE 1
BRD-2 BD1
BRD-2 BD2
BRD-3 BD1
BRD-3 BD2
BRD-4 BD1
BRD-4 BD2
a
TRP97
TRP370
TRP57
TRP332
TRP81
TRP374
b
PRO98
PRO371
PRO58
PRO333
PRO82
PRO375
c
TYR113
TYR386
TYR73
TYR348
TYR97
TYR390
d
ASN156
ASN429
ASN116
ASN391
ASN140
ASN433
e
ASP161
ASP434
ASP121
GLU396
ASP145
GLU438
f
ILE162
VAL435
ILE122
VAL397
ILE146
VAL439
g
MET165
MET438
MET125
MET400
MET149
MET442
Thus, in a first aspect the invention provides a process for the identification of compounds with a molecular weight in the range 100 to 750 which inhibit the binding of the first and/or second bromodomains of human BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins which comprises selecting those compounds which are able to:
a) form a hydrogen bonding interaction in which the compound accepts a hydrogen bond from the sidechain NH2 group of the asparagine residue found at:
BRD-2 BRD-2 BRD-3 BRD-3 BRD-4 BD1 BD2 BD1 BD2 BD1 BRD-4 BD2 ASN156 ASN429 ASN116 ASN391 ASN140 ASN433
or
b) accept a water-mediated hydrogen bond in which the compound accepts a hydrogen bond from a water that is itself hydrogen-bonded to the sidechain hydroxyl of the tyrosine residue found at
BRD-2 BRD-2 BRD-3 BRD-3 BD1 BD2 BD1 BD2 BRD-4 BD1 BRD-4 BD2 TYR113 TYR386 TYR73 TYR348 TYR97 TYR390
and
c) which are also able to form a Van der Waals interaction with a lipophilic binding region of a binding pocket such that one or more heavy atoms of the said compounds lie within a 5 Å range of any of the heavy atoms of the following bromodomain residues which define the binding pocket:
BRD-2 BD1
BRD-2 BD2
BRD-3 BD1
BRD-3 BD2
BRD-4 BD1
BRD-4 BD2
TRP97
TRP370
TRP57
TRP332
TRP81
TRP374
PRO98
PRO371
PRO58
PRO333
PRO82
PRO375
ASP161
ASP434
ASP121
GLU396
ASP145
GLU438
ILE162
VAL435
ILE122
VAL397
ILE146
VAL439
MET165
MET438
MET125
MET400
MET149
MET442
In a further aspect of the invention there is provided a process for the identification of compounds with a molecular weight in the range 100 to 750 which inhibit the binding of the first and/or second bromodomains of human BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins which comprises selecting those compounds which are able to:
a) form a hydrogen bonding interaction in which the compound accepts a hydrogen bond from the sidechain NH2 group of the asparagine residue found at:
BRD-2 BD1 BRD-2 BD2 BRD-3 BD1 BRD-3 BD2 BRD-4 BD1 BRD-4 BD2 ASN156 ASN429 ASN116 ASN391 ASN140 ASN433
and
b) accept a water-mediated hydrogen bond in which the compound accepts a hydrogen bond from a water that is itself hydrogen-bonded to the sidechain hydroxyl of the tyrosine residue found at
BRD-2 BD1 BRD-2 BD2 BRD-3 BD1 BRD-3 BD2 BRD-4 BD1 BRD-4 BD2 TYR113 TYR386 TYR73 TYR348 TYR97 TYR390
and
c) which are also able to form a Van der Waals interaction with a lipophilic binding region of a binding pocket such that one or more heavy atoms of the said compounds lie within a 5 Å range of any of the heavy atoms of the following bromodomain residues which define the binding pocket:
BRD-2 BD1
BRD-2 BD2
BRD-3 BD1
BRD-3 BD2
BRD-4 BD1
BRD-4 BD2
TRP97
TRP370
TRP57
TRP332
TRP81
TRP374
PRO98
PRO371
PRO58
PRO333
PRO82
PRO375
ASP161
ASP434
ASP121
GLU396
ASP145
GLU438
ILE162
VAL435
ILE122
VAL397
ILE146
VAL439
MET165
MET438
MET125
MET400
MET149
MET442
In a further aspect of the invention there is provided a process wherein step (c) requires the compounds to be able to form a Van der Waals interaction with a lipophilic binding region of a binding pocket such that one or more heavy atoms of the said compounds lie within 7.5 Å of at least one heavy atom of each of the 3 residues listed for a given bromodomain
BRD-2 BD1
BRD-2 BD2
BRD-3 BD1
BRD-3 BD2
BRD-4 BD1
BRD-4 BD2
PRO98
PRO371
PRO58
PRO333
PRO82
PRO375
ASP161
ASP434
ASP121
GLU396
ASP145
GLU438
ILE162
VAL435
ILE122
VAL397
ILE146
VAL439
In a yet further aspect of the invention there is provided a process wherein step (a) and/or (b) is performed first to allow identification of a compound fragment, before step (c) is performed to modify the fragment identified from steps (a) and/or (b) to provide a compound with a molecular weight in the range 100 to 750 which inhibit the binding of the first and/or second bromodomains of human BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins. The person skilled in the art will recognise this to be fragment based compound identification and optimisation.
In a further aspect the invention provides a process for the identification of compounds with a molecular weight in the range 100 to 500 which inhibit the binding of the first and/or second bromodomains of human BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins which comprises selecting those compounds which are able to:
a) form a hydrogen bonding interaction in which the compound accepts a hydrogen bond from the sidechain NH2 group of the asparagine residue found at:
BRD-2 BD1 BRD-2 BD2 BRD-3 BD1 BRD-3 BD2 BRD-4 BD1 BRD-4 BD2 ASN156 ASN429 ASN116 ASN391 ASN140 ASN433
or
b) accept a water-mediated hydrogen bond in which the compound accepts a hydrogen bond from a water that is itself hydrogen-bonded to the sidechain hydroxyl of the tyrosine residue found at
BRD-2 BD1 BRD-2 BD2 BRD-3 BD1 BRD-3 BD2 BRD-4 BD1 BRD-4 BD2 TYR113 TYR386 TYR73 TYR348 TYR97 TYR390
and
c) which are also able to form a Van der Waals interaction with a lipophilic binding region of a binding pocket such that one or more heavy atoms of the said compounds lie within a 5 Å range of any of the heavy atoms of the following bromodomain residues which define the binding pocket:
BRD-2 BD1
BRD-2 BD2
BRD-3 BD1
BRD-3 BD2
BRD-4 BD1
BRD-4 BD2
TRP97
TRP370
TRP57
TRP332
TRP81
TRP374
PRO98
PRO371
PRO58
PRO333
PRO82
PRO375
ASP161
ASP434
ASP121
GLU396
ASP145
GLU438
ILE162
VAL435
ILE122
VAL397
ILE146
VAL439
MET165
MET438
MET125
MET400
MET149
MET442
In a further aspect of the invention there is provided a process for the identification of compounds with a molecular weight in the range 100 to 500 which inhibit the binding of the first and/or second bromodomains of human BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins which comprises selecting those compounds which are able to:
a) form a hydrogen bonding interaction in which the compound accepts a hydrogen bond from the sidechain NH2 group of the asparagine residue found at:
BRD-2 BD1 BRD-2 BD2 BRD-3 BD1 BRD-3 BD2 BRD-4 BD1 BRD-4 BD2 ASN156 ASN429 ASN116 ASN391 ASN140 ASN433
and
b) accept a water-mediated hydrogen bond in which the compound accepts a hydrogen bond from a water that is itself hydrogen-bonded to the sidechain hydroxyl of the tyrosine residue found at
BRD-2 BD1 BRD-2 BD2 BRD-3 BD1 BRD-3 BD2 BRD-4 BD1 BRD-4 BD2 TYR113 TYR386 TYR73 TYR348 TYR97 TYR390
and
c) which are also able to form a Van der Waals interaction with a lipophilic binding region of a binding pocket such that one or more heavy atoms of the said compounds lie within a 5 Å range of any of the heavy atoms of the following bromodomain residues which define the binding pocket:
BRD-2 BD1
BRD-2 BD2
BRD-3 BD1
BRD-3 BD2
BRD-4 BD1
BRD-4 BD2
TRP97
TRP370
TRP57
TRP332
TRP81
TRP374
PRO98
PRO371
PRO58
PRO333
PRO82
PRO375
ASP161
ASP434
ASP121
GLU396
ASP145
GLU438
ILE162
VAL435
ILE122
VAL397
ILE146
VAL439
MET165
MET438
MET125
MET400
MET149
MET442
In a further aspect of the invention there is provided a process wherein step (c) requires the compounds to be able to form a Van der Waals interaction with a lipophilic binding region of a binding pocket such that one or more heavy atoms of the said compounds lie within 7.5 Å of at least one heavy atom of each of the 3 residues listed for a given bromodomain
BRD-2 BD1
BRD-2 BD2
BRD-3 BD1
BRD-3 BD2
BRD-4 BD1
BRD-4 BD2
PRO98
PRO371
PRO58
PRO333
PRO82
PRO375
ASP161
ASP434
ASP121
GLU396
ASP145
GLU438
ILE162
VAL435
ILE122
VAL397
ILE146
VAL439
In a yet further aspect of the invention there is provided a process wherein step (a) and/or (b) is performed first to allow identification of a compound fragment, before step (c) is performed to modify the fragment identified from steps (a) and/or (b) to provide a compound with a molecular weight in the range 100 to 500 which inhibit the binding of the first and/or second bromodomains of human BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins. The person skilled in the art will recognise this to be fragment based compound identification and optimisation.
There are many ways in which compounds that take advantage of the interactions described above may be discovered or designed. In a process known as virtual screening, molecules can be identified from databases of real or virtual compounds. Methods to do this may make use of the protein structure, (e.g. docking), of the 3D ligand structure, (e.g. pharmacophore searching, shape-based or field-based similarity searching), or of the 2D ligand structure (e.g. similarity or substructure searching), or by combinations of these approaches. Similar methods may also be used to design new compounds, either from first principles or by modification of existing active molecules, in a process known as de novo design. A person skilled in the art will be aware of many ways in which such activities can be carried out, including but not limited to those described in review articles, recent examples of which include Muegge & Oloff, Drug Discovery Today: Technologies, 2006, 3, 405-411; Kontoyianni et al. Current Medicinal Chemistry, 2008, 15, 107-116; Seifert & Lang, Mini-Reviews in Medicinal Chemistry, 2007, 63-72; the sections of Comprehensive Medicinal Chemistry II, Vol 4: Computer-Assisted Drug Design, ed. Taylor & Triggle, Elsevier 2007.
The compounds identified using the above-mentioned processes form a further aspect of the invention and are hereinafter referred to as “compounds of the invention”.
It will be appreciated that, whilst the compounds of the invention may bind to each of BD1 and 2 of the human BRD-2 to 4 proteins, the kinetics and binding affinity may be different at each of these binding sites.
It will be appreciated that when synthesised the compounds of the invention may exist as a free base or a salt or solvate thereof, for example as a pharmaceutically acceptable salt thereof. The present invention covers compounds of the invention as the free base and as salts thereof, for example as a pharmaceutically acceptable salt thereof. In one embodiment the invention relates to compounds of the invention or a pharmaceutically acceptable salt thereof.
Because of their potential use in medicine, salts of the compounds of the invention are desirably pharmaceutically acceptable. Suitable pharmaceutically acceptable salts can include acid or base addition salts. As used herein, the term ‘pharmaceutically acceptable salt’ means any pharmaceutically acceptable salt or solvate of a compound of the invention, which upon administration to the recipient is capable of providing (directly or indirectly). For a review on suitable salts see Berge et al., J. Pharm. Sci., 66:1-19, (1977). Typically, a pharmaceutically acceptable salt may be readily prepared by using a desired acid or base as appropriate. The resultant salt may precipitate from solution and be collected by filtration or may be recovered by evaporation of the solvent.
A pharmaceutically acceptable base addition salt can be formed by reaction of a compound of the invention with a suitable inorganic or organic base, (e.g. triethylamine, ethanolamine, triethanolamine, choline, arginine, lysine or histidine), optionally in a suitable solvent, to give the base addition salt which is usually isolated, for example, by crystallisation and filtration. Pharmaceutically acceptable base salts include ammonium salts, alkali metal salts such as those of sodium and potassium, alkaline earth metal salts such as those of calcium and magnesium and salts with organic bases, including salts of primary, secondary and tertiary amines, such as isopropylamine, diethylamine, ethanolamine, trimethylamine, dicyclohexyl amine and N-methyl-D-glucamine.
A pharmaceutically acceptable acid addition salt can be formed by reaction of a compound of the invention with a suitable inorganic or organic acid (such as hydrobromic, hydrochloric, sulphuric, nitric, phosphoric, succinc, maleic, acetic, propionic, fumaric, citric, tartaric, lactic, benzoic, salicylic, glutamaic, aspartic, p-toluenesulfonic, benzenesulfonic, methanesulfonic, ethanesulfonic, naphthalenesulfonic such as 2-naphthalenesulfonic, or hexanoic acid), optionally in a suitable solvent such as an organic solvent, to give the salt which is usually isolated for example by crystallisation and filtration. A pharmaceutically acceptable acid addition salt of a compound of the invention can comprise or be for example a hydrobromide, hydrochloride, sulfate, nitrate, phosphate, succinate, maleate, acetate, propionate, fumarate, citrate, tartrate, lactate, benzoate, salicylate, glutamate, aspartate, p-toluenesulfonate, benzenesulfonate, methanesulfonate, ethanesulfonate, naphthalenesulfonate (e.g. 2-naphthalenesulfonate) or hexanoate salt.
Other non-pharmaceutically acceptable salts, e.g. formates, oxalates or trifluoroacetates, may be used, for example in the isolation of the compounds of the invention, and are included within the scope of this invention.
The invention includes within its scope all possible stoichiometric and non-stoichiometric forms of the salts of the compounds of the invention.
It will be appreciated that many organic compounds can form complexes with solvents in which they are reacted or from which they are precipitated or crystallized. These complexes are known as “solvates”. For example, a complex with water is known as a “hydrate”. Solvents with high boiling points and/or capable of forming hydrogen bonds such as water, xylene, N-methyl pyrrolidinone, methanol and ethanol may be used to form solvates. Methods for identification of solvates include, but are not limited to, NMR and microanalysis. Solvates of the compounds of the invention are within the scope of the invention.
The invention includes within its scope all possible stoichiometric and non-stoichiometric forms of the solvates of the compounds of the invention.
The invention encompasses all prodrugs, of the compound of the invention, which upon administration to the recipient is capable of providing (directly or indirectly) the compound of the invention, or an active metabolite or residue thereof. Such derivatives are recognizable to those skilled in the art, without undue experimentation. Nevertheless, reference is made to the teaching of Burger's Medicinal Chemistry and Drug Discovery, 5 th Edition, Vol 1: Principles and Practice, which is incorporated herein by reference to the extent of teaching such derivatives.
The compounds of the invention may be in crystalline or amorphous form. Furthermore, some of the crystalline forms of the compounds of the invention may exist as polymorphs, which are included within the scope of the present invention. Polymorphic forms of compounds of the invention may be characterized and differentiated using a number of conventional analytical techniques, including, but not limited to, X-ray powder diffraction (XRPD) patterns, infrared (IR) spectra, Raman spectra, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and solid state nuclear magnetic resonance (SSNMR).
Certain compounds of the invention may exist in one of several tautomeric forms. It will be understood that the present invention encompasses all tautomers of the compounds of the invention whether as individual tautomers or as mixtures thereof.
It will be appreciated from the foregoing that included within the scope of the invention are solvates, hydrates, complexes and polymorphic forms of the compounds of the invention and salts thereof.
The compounds of the invention are bromodomain inhibitors, and thus to believed to have potential utility in the treatment of diseases or conditions for which a bromodomain is indicated.
The present invention thus provides a compound of the invention for use in therapy. The compound of the invention can be for use in the treatment of diseases or conditions for which a bromodomain inhibitor indicated.
The present invention thus provides a compound of the invention for use in the treatment of any diseases or conditions for which a bromodomain is indicated.
Also provided is the use of a compound of the invention in the manufacture of a medicament for the treatment of diseases or conditions for which a bromodomain inhibitor is indicated.
Also provided is a method of treating diseases or conditions for which a bromodomain inhibitor is indicated in a subject in need thereof which comprises administering a therapeutically effective amount of compound of the invention or a pharmaceutically acceptable salt thereof.
Suitably the subject in need thereof is a mammal, particularly a human.
As used herein, the term “effective amount” means that amount of a drug or pharmaceutical agent that will elicit the biological or medical response of a tissue, system, animal or human that is being sought, for instance, by a researcher or clinician. Furthermore, the term “therapeutically effective amount” means any amount which, as compared to a corresponding subject who has not received such amount, results in improved treatment, healing, prevention, or amelioration of a disease, disorder, or side effect, or a decrease in the rate of advancement of a disease or disorder. The term also includes within its scope amounts effective to enhance normal physiological function.
Bromodomain inhibitors are believed to be useful in the treatment of a variety of diseases or conditions related to systemic or tissue inflammation, inflammatory responses to infection or hypoxia, cellular activation and proliferation, lipid metabolism, fibrosis and in the prevention and treatment of viral infections.
Bromodomain inhibitors may be useful in the treatment of a wide variety of chronic autoimmune and inflammatory conditions such as rheumatoid arthritis, osteoarthritis, acute gout, psoriasis, systemic lupus erythematosus, multiple sclerosis, inflammatory bowel disease (Crohn's disease and Ulcerative colitis), asthma, chronic obstructive airways disease, pneumonitis, myocarditis, pericarditis, myositis, eczema, dermatitis, alopecia, vitiligo, bullous skin diseases, nephritis, vasculitis, atherosclerosis, Alzheimer's disease, depression, retinitis, uveitis, scleritis, hepatitis, pancreatitis, primary biliary cirrhosis, sclerosing cholangitis, Addison's disease, hypophysitis, thyroiditis, type I diabetes and acute rejection of transplanted organs.
Bromodomain inhibitors may be useful in the treatment of a wide variety of acute inflammatory conditions such as acute gout, giant cell arteritis, nephritis including lupus nephritis, vasculitis with organ involvement such as glomerulonephritis, vasculitis including giant cell arteritis, Wegener's granulomatosis, Polyarteritis nodosa, Behcet's disease, Kawasaki disease, Takayasu's Arteritis, vasculitis with organ involvement, acute rejection of transplanted organs.
Bromodomain inhibitors may be useful in the prevention or treatment of diseases or conditions which involve inflammatory responses to infections with bacteria, viruses, fungi, parasites or their toxins, such as sepsis, sepsis syndrome, septic shock, endotoxaemia, systemic inflammatory response syndrome (SIRS), multi-organ dysfunction syndrome, toxic shock syndrome, acute lung injury, ARDS (adult respiratory distress syndrome), acute renal failure, fulminant hepatitis, burns, acute pancreatitis, post-surgical syndromes, sarcoidosis, Herxheimer reactions, encephalitis, myelitis, meningitis, malaria and SIRS associated with viral infections such as influenza, herpes zoster, herpes simplex and coronavirus.
Bromodomain inhibitors may be useful in the prevention or treatment of conditions associated with ischaemia-reperfusion injury such as myocardial infarction, cerebro-vascular ischaemia (stroke), acute coronary syndromes, renal reperfusion injury, organ transplantation, coronary artery bypass grafting, cardio-pulmonary bypass procedures, pulmonary, renal, hepatic, gastro-intestinal or peripheral limb embolism.
Bromodomain inhibitors may be useful in the treatment of disorders of lipid metabolism via the regulation of APO-A1 such as hypercholesterolemia, atherosclerosis and Alzheimer's disease.
Bromodomain inhibitors may be useful in the treatment of fibrotic conditions such as idiopathic pulmonary fibrosis, renal fibrosis, post-operative stricture, keloid formation, scleroderma and cardiac fibrosis.
Bromodomain inhibitors may be useful in the prevention and treatment of viral infections such as herpes virus, human papilloma virus, adenovirus and poxvirus and other DNA viruses.
Bromodomain inhibitors may be useful in the treatment of cancer, including hematological, epithelial including lung, breast and colon carcinomas, midline carcinomas, mesenchymal, hepatic, renal and neurological tumours.
The term “diseases or conditions for which a bromodomain inhibitor is indicated”, is intended to include any of or all of the above disease states.
In one embodiment the disease or condition for which a bromodomain inhibitor is indicated is selected from diseases associated with systemic inflammatory response syndrome, such as sepsis, burns, pancreatitis, major trauma, haemorrhage and ischaemia. In this embodiment the bromodomain inhibitor would be administered at the point of diagnosis to reduce the incidence of: SIRS, the onset of shock, multi-organ dysfunction syndrome, which includes the onset of acute lung injury, ARDS, acute renal, hepatic, cardiac and gastro-intestinal injury and mortality. In another embodiment the bromodomain inhibitor would be administered prior to surgical or other procedures associated with a high risk of sepsis, haemorrhage, extensive tissue damage, SIRS or MODS (multiple organ dysfunction syndrome). In a particular embodiment the disease or condition for which a bromodomain inhibitor is indicated is sepsis, sepsis syndrome, septic shock or endotoxaemia. In another embodiment, the bromodomain inhibitor is indicated for the treatment of acute or chronic pancreatitis. In another embodiment the bromodomain is indicated for the treatment of burns.
In one embodiment the disease or condition for which a bromodomain inhibitor is indicated is selected from herpes simplex infections and reactivations, cold sores, herpes zoster infections and reactivations, chickenpox, shingles, human papilloma virus, cervical neoplasia, adenovirus infections, including acute respiratory disease, poxvirus infections such as cowpox and smallpox and African swine fever virus. In one particular embodiment a bromodomain inhibitor is indicated for the treatment of Human papilloma virus infections of skin or cervical epithelia.
While it is possible that for use in therapy, a compound of the invention as well as pharmaceutically acceptable salts thereof may be administered as the raw chemical, it is common to present the active ingredient as a pharmaceutical composition.
The present invention therefore provides in a further aspect a pharmaceutical composition comprising a compound of the invention or a pharmaceutically acceptable salt and one or more or pharmaceutically acceptable carriers, diluents and/or excipients. The compounds of the formula (I) and pharmaceutically acceptable salts, are as described above. The carrier(s), diluent(s) or excipient(s) must be acceptable in the sense of being compatible with the other ingredients of the composition and not deleterious to the recipient thereof. In accordance with another aspect of the invention there is also provided a process for the preparation of a pharmaceutical composition including admixing a compound of the formula (I), or a pharmaceutically acceptable salt thereof, with one or more pharmaceutically acceptable carriers, diluents or excipients. The pharmaceutical composition can be for use in the treatment of any of the conditions described herein.
Since the compounds of the invention are intended for use in pharmaceutical compositions it will be readily understood that they are each preferably provided in substantially pure form, for example, at least 60% pure, more suitably at least 75% pure and preferably at least 85% pure, especially at least 98% pure (% in a weight for weight basis).
Pharmaceutical compositions may be presented in unit dose forms containing a predetermined amount of active ingredient per unit dose. Preferred unit dosage compositions are those containing a daily dose or sub-dose, or an appropriate fraction thereof, of an active ingredient. Such unit doses may therefore be administered more than once a day. Preferred unit dosage compositions are those containing a daily dose or sub-dose (for administration more than once a day), as herein above recited, or an appropriate fraction thereof, of an active ingredient.
Pharmaceutical compositions may be adapted for administration by any appropriate route, for example by the oral (including buccal or sublingual), rectal, inhaled, intranasal, topical (including buccal, sublingual or transdermal), vaginal or parenteral (including subcutaneous, intramuscular, intravenous or intradermal) route. Such compositions may be prepared by any method known in the art of pharmacy, for example by bringing into association the active ingredient with the carrier(s) or excipient(s).
In one embodiment the pharmaceutical composition is adapted for parenteral administration, particularly intravenous administration.
Pharmaceutical compositions adapted for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the composition isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The compositions may be presented in unit-dose or multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets.
Pharmaceutical compositions adapted for oral administration may be presented as discrete units such as capsules or tablets; powders or granules; solutions or suspensions in aqueous or non-aqueous liquids; edible foams or whips; or oil-in-water liquid emulsions or water-in-oil liquid emulsions.
For instance, for oral administration in the form of a tablet or capsule, the active drug component can be combined with an oral, non-toxic pharmaceutically acceptable inert carrier such as ethanol, glycerol, water and the like. Powders suitable for incorporating into tablets or capsules may be prepared by reducing the compound to a suitable fine size (e.g. by micronisation) and mixing with a similarly prepared pharmaceutical carrier such as an edible carbohydrate, as, for example, starch or mannitol. Flavoring, preservative, dispersing and coloring agent can also be present.
Capsules may be made by preparing a powder mixture, as described above, and filling formed gelatin sheaths. Glidants and lubricants such as colloidal silica, talc, magnesium stearate, calcium stearate or solid polyethylene glycol can be added to the powder mixture before the filling operation. A disintegrating or solubilizing agent such as agar-agar, calcium carbonate or sodium carbonate can also be added to improve the availability of the medicament when the capsule is ingested.
Moreover, when desired or necessary, suitable binders, glidants, lubricants, sweetening agents, flavours, disintegrating agents and coloring agents can also be incorporated into the mixture. Suitable binders include starch, gelatin, natural sugars such as glucose or beta-lactose, corn sweeteners, natural and synthetic gums such as acacia, tragacanth or sodium alginate, carboxymethylcellulose, polyethylene glycol, waxes and the like. Lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride and the like. Disintegrators include, without limitation, starch, methyl cellulose, agar, bentonite, xanthan gum and the like. Tablets are formulated, for example, by preparing a powder mixture, granulating or slugging, adding a lubricant and disintegrant and pressing into tablets. A powder mixture is prepared by mixing the compound, suitably comminuted, with a diluent or base as described above, and optionally, with a binder such as carboxymethylcellulose, an aliginate, gelatin, or polyvinyl pyrrolidone, a solution retardant such as paraffin, a resorption accelerator such as a quaternary salt and/or an absorption agent such as bentonite, kaolin or dicalcium phosphate. The powder mixture can be granulated by wetting with a binder such as syrup, starch paste, acadia mucilage or solutions of cellulosic or polymeric materials and forcing through a screen. As an alternative to granulating, the powder mixture can be run through the tablet machine and the result is imperfectly formed slugs broken into granules. The granules can be lubricated to prevent sticking to the tablet forming dies by means of the addition of stearic acid, a stearate salt, talc or mineral oil. The lubricated mixture is then compressed into tablets. The compounds of the present invention can also be combined with a free flowing inert carrier and compressed into tablets directly without going through the granulating or slugging steps. A clear or opaque protective coating consisting of a sealing coat of shellac, a coating of sugar or polymeric material and a polish coating of wax can be provided. Dyestuffs can be added to these coatings to distinguish different unit dosages.
Oral fluids such as solution, syrups and elixirs can be prepared in dosage unit form so that a given quantity contains a predetermined amount of the compound. Syrups can be prepared by dissolving the compound in a suitably flavored aqueous solution, while elixirs are prepared through the use of a non-toxic alcoholic vehicle. Suspensions can be formulated by dispersing the compound in a non-toxic vehicle. Solubilizers and emulsifiers such as ethoxylated isostearyl alcohols and polyoxy ethylene sorbitol ethers, preservatives, flavor additive such as peppermint oil or natural sweeteners or saccharin or other artificial sweeteners, and the like can also be added.
Where appropriate, dosage unit compositions for oral administration can be microencapsulated. The formulation can also be prepared to prolong or sustain the release as for example by coating or embedding particulate material in polymers, wax or the like.
The compounds of the invention can also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamellar vesicles and multilamellar vesicles. Liposomes can be formed from a variety of phospholipids, such as cholesterol, stearylamine or phosphatidylcholines.
Pharmaceutical compositions adapted for topical administration may be formulated as ointments, creams, suspensions, lotions, powders, solutions, pastes, gels, sprays, aerosols or oils.
For treatments of the eye or other external tissues, for example mouth and skin, the compositions are preferably applied as a topical ointment or cream. When formulated in an ointment, the active ingredient may be employed with either a paraffinic or a water-miscible ointment base. Alternatively, the active ingredient may be formulated in a cream with an oil-in-water cream base or a water-in-oil base.
Pharmaceutical compositions adapted for topical administrations to the eye include eye drops wherein the active ingredient is dissolved or suspended in a suitable carrier, especially an aqueous solvent.
Dosage forms for nasal or inhaled administration may conveniently be formulated as aerosols, solutions, suspensions, gels or dry powders.
For compositions suitable and/or adapted for inhaled administration, it is preferred that the compound of the invention is in a particle-size-reduced form e.g. obtained by micronisation. The preferable particle size of the size-reduced (e.g. micronised) compound or salt is defined by a D50 value of about 0.5 to about 10 microns (for example as measured using laser diffraction).
Aerosol formulations, e.g. for inhaled administration, can comprise a solution or fine suspension of the active substance in a pharmaceutically acceptable aqueous or non-aqueous solvent. Aerosol formulations can be presented in single or multidose quantities in sterile form in a sealed container, which can take the form of a cartridge or refill for use with an atomising device or inhaler. Alternatively the sealed container may be a unitary dispensing device such as a single dose nasal inhaler or an aerosol dispenser fitted with a metering valve (metered dose inhaler) which is intended for disposal once the contents of the container have been exhausted.
Where the dosage form comprises an aerosol dispenser, it preferably contains a suitable propellant under pressure such as compressed air, carbon dioxide or an organic propellant such as a hydrofluorocarbon (HFC). Suitable HFC propellants include 1,1,1,2,3,3,3-heptafluoropropane and 1,1,1,2-tetrafluoroethane. The aerosol dosage forms can also take the form of a pump-atomiser. The pressurised aerosol may contain a solution or a suspension of the active compound. This may require the incorporation of additional excipients e.g. co-solvents and/or surfactants to improve the dispersion characteristics and homogeneity of suspension formulations. Solution formulations may also require the addition of co-solvents such as ethanol.
For pharmaceutical compositions suitable and/or adapted for inhaled administration, the pharmaceutical composition may be a dry powder inhalable composition. Such a composition can comprise a powder base such as lactose, glucose, trehalose, mannitol or starch, the compound of the invention or salt thereof (preferably in particle-size-reduced form, e.g. in micronised form), and optionally a performance modifier such as L-leucine or another amino acid and/or metals salts of stearic acid such as magnesium or calcium stearate. Preferably, the dry powder inhalable composition comprises a dry powder blend of lactose e.g. lactose monohydrate and the compound of the invention or salt thereof. Such compositions can be administered to the patient using a suitable device such as the DISKUS® device, marketed by GlaxoSmithKline which is for example described in GB 2242134 A.
The compounds of the invention thereof may be formulated as a fluid formulation for delivery from a fluid dispenser, for example a fluid dispenser having a dispensing nozzle or dispensing orifice through which a metered dose of the fluid formulation is dispensed upon the application of a user-applied force to a pump mechanism of the fluid dispenser. Such fluid dispensers are generally provided with a reservoir of multiple metered doses of the fluid formulation, the doses being dispensable upon sequential pump actuations. The dispensing nozzle or orifice may be configured for insertion into the nostrils of the user for spray dispensing of the fluid formulation into the nasal cavity. A fluid dispenser of the aforementioned type is described and illustrated in WO-A-2005/044354.
A therapeutically effective amount of a compound of the present invention will depend upon a number of factors including, for example, the age and weight of the animal, the precise condition requiring treatment and its severity, the nature of the formulation, and the route of administration, and will ultimately be at the discretion of the attendant physician or veterinarian. In the pharmaceutical composition, each dosage unit for oral or parenteral administration preferably contains from 0.01 to 3000 mg, more preferably 0.5 to 1000 mg, of a compound of the invention calculated as the free base. Each dosage unit for nasal or inhaled administration preferably contains from 0.001 to 50 mg, more preferably 0.01 to 5 mg, of a compound of the formula (I) or a pharmaceutically acceptable salt thereof, calculated as the free base.
The pharmaceutically acceptable compounds the invention can be administered in a daily dose (for an adult patient) of, for example, an oral or parenteral dose of 0.01 mg to 3000 mg per day or 0.5 to 1000 mg per day, or a nasal or inhaled dose of 0.001 to 50 mg per day or 0.01 to 5 mg per day, of the compound of the formula (I) or a pharmaceutically acceptable salt thereof, calculated as the free base. This amount may be given in a single dose per day or more usually in a number (such as two, three, four, five or six) of sub-doses per day such that the total daily dose is the same. An effective amount of a salt thereof, may be determined as a proportion of the effective amount of the compound of the invention per se.
The compounds of the invention and may be employed alone or in combination with other therapeutic agents. Combination therapies according to the present invention thus comprise the administration of at least one compound of the invention or a pharmaceutically acceptable salt thereof, and the use of at least one other pharmaceutically active agent. Preferably, combination therapies according to the present invention comprise the administration of at least one compound of the invention or a pharmaceutically acceptable salt thereof, and at least one other pharmaceutically active agent. The compound(s) of the invention and the other pharmaceutically active agent(s) may be administered together in a single pharmaceutical composition or separately and, when administered separately this may occur simultaneously or sequentially in any order. The amounts of the compound(s) of the invention and the other pharmaceutically active agent(s) and the relative timings of administration will be selected in order to achieve the desired combined therapeutic effect. Thus in a further aspect, there is provided a combination comprising a compound of the invention and at least one other pharmaceutically active agent.
Thus in one aspect, the compound and pharmaceutical compositions according to the invention may be used in combination with or include one or more other therapeutic agents, for example selected from antibiotics, anti-virals, glucocorticosteroids, muscarinic antagonists and beta-2 agonists.
It will be appreciated that when the compound of the present invention is administered in combination with other therapeutic agents normally administered by the inhaled, intravenous, oral or intranasal route, that the resultant pharmaceutical composition may be administered by the same routes. Alternatively the individual components of the composition may be administered by different routes.
One embodiment of the invention encompasses combinations comprising one or two other therapeutic agents.
It will be clear to a person skilled in the art that, where appropriate, the other therapeutic ingredient(s) may be used in the form of salts, for example as alkali metal or amine salts or as acid addition salts, or prodrugs, or as esters, for example lower alkyl esters, or as solvates, for example hydrates, to optimise the activity and/or stability and/or physical characteristics, such as solubility, of the therapeutic ingredient. It will be clear also that, where appropriate, the therapeutic ingredients may be used in optically pure form.
The combinations referred to above may conveniently be presented for use in the form of a pharmaceutical composition and thus pharmaceutical compositions comprising a combination as defined above together with a pharmaceutically acceptable diluent or carrier represent a further aspect of the invention.
Background Experimental
LCMS Methods
Method B
LC/MS (Method B) was conducted on an Acquity UPLC BEH C18 column (50 mm×2.1 mm i.d. 1.7 μm packing diameter) at 40 degrees centigrade, eluting with 0.1% v/v solution of Formic Acid in Water (Solvent A) and 0.1% v/v solution of Formic Acid in Acetonitrile (Solvent B) using the following elution gradient 0-1.5 min 3-100% B, 1.5-1.9 min 100% B, 1.9-2.0 min 3% B at a flow rate of 1 ml/min. The UV detection was a summed signal from wavelength of 210 nm to 350 nm. The mass spectra were recorded on a Waters ZQ Mass Spectrometer using Alternate-scan Positive and Negative Electrospray. Ionisation data was rounded to the nearest integer.
Method D
LC/MS (Method D) was conducted on a Supelcosil LCABZ+PLUS column (3 μm, 3.3 cm×4.6 mm ID) eluting with 0.1% HCO 2 H and 0.01 M ammonium acetate in water (solvent A), and 95% acetonitrile and 0.05% HCO 2 H in water (solvent B), using the following elution gradient 0-0.7 minutes 0% B, 0.7-4.2 minutes 0→100% B, 4.2-5.3 minutes 100% B, 5.3-5.5 minutes 100→0% B at a flow rate of 3 mL/minute. The mass spectra (MS) were recorded on a Fisons VG Platform mass spectrometer using electrospray positive ionisation [(ES+ve to give [M+H] + and [M+NH 4 ] + molecular ions] or electrospray negative ionisation [(ES−ve to give [M−H]− molecular ion] modes. Analytical data from this apparatus are given with the following format: [M+H] + or [M−H] − .
Method E
LC/MS (Method E) was conducted on a Chromolith Performance RP 18 column (100×4.6 mm id) eluting with 0.01M ammonium acetate in water (solvent A) and 100% acetonitrile (solvent B), using the following elution gradient 0-4 minutes 0-100% B, 4-5 minutes 100% B at a flow rate of 5 ml/minute. The mass spectra (MS) were recorded on a micromass Platform-LC mass spectrometer using atmospheric pressure chemical positive ionisation [AP+ve to give MH+ molecular ions] or atmospheric pressure chemical negative ionisation [AP−ve to give (M−H)− molecular ions] modes. Analytical data from this apparatus are given with the following format: [M+H]+ or [M−H]−.
Method F
LC/MS (Method F) was conducted on an Sunfire C18 column (30 mm×4.6 mm i.d. 3.5 μm packing diameter) at 30 degrees centigrade, eluting with 0.1% v/v solution of Trifluoroacetic Acid in Water (Solvent A) and 0.1% v/v solution of Trifluoroacetic Acid in Acetonitrile (Solvent B) using the following elution gradient 0-0.1 min 3% B, 0.1-4.2 min 3-100% B, 4.2-4.8 min 100% B, 4.8-4.9 min 100-3% B, 4.9-5.0 min 3% B at a flow rate of 3 ml/min. The UV detection was an averaged signal from wavelength of 210 nm to 350 nm and mass spectra were recorded on a mass spectrometer using positive electrospray ionization. Ionisation data was rounded to the nearest integer.
Compound (I)
(+)-Phenylmethyl (1-methyl-6-phenyl-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl)carbamate
Racemic mixture of phenylmethyl (1-methyl-6-phenyl-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl)carbamate [prepared according to the procedure described in the J. Med. Chem., (1988, 31(1), 176-181)] was separated by HPLC using a (R,R) whelk-01 column with Hexane/EtOH as the mobile phase. The sample was prepared in a 80/20 mixture EtOH/Hexane (Note: the sample required heating and filtering prior to addition to the column). The system used for preparative separation was as follows: Column: (R,R) Whel-01 51×250 mm column (2 inch columns); mobile phase: 50/50, Hexane/EtOH; Flow rate: 45.0 mL/min; UV wavelength: 254 nm. The title compound eluted at 49 min as the first peak. [α] D =+44.7 c=1.0525 (g/100 mL)/MeOH. The other enantiomer came off at 58 minutes.
Intermediate 1
[1-(1H-1,2,3-benzotriazol-1-yl)ethyl](4-bromophenyl)amine
To a suspension of benzotriazole (139 g, 1.16 mol) in toluene (2 L) in a 3 L, four neck flask under nitrogen atmosphere was added at room temperature a solution of 4-bromoaniline (200 g, 1.16 mol) in toluene (300 mL). Then, via a dropping funnel was added drop wise acetaldehyde (64.7 ml, 1.17 mol) in solution in toluene (200 mL). The reaction mixture becomes progressively homogenous and then gives a precipitate. The resulting mixture is stirred 12 hours under nitrogen atmosphere and then filtered. The precipitate is recrystallised in toluene to afford the title compound as a white solid (304 g, 82%).
1H NMR (300 MHz, CHLOROFORM-d) δ ppm 2.1 (m, 3H) 4.9 (m, 0.66H) 5.15 (m, 0.33H) 6.5-6.9 (m, 3H) 7.2-8.2 (m, 7H)
Intermediate 2
(6-bromo-2-methyl-1,2,3,4-tetrahydro-4-quinolinyl)formamide
A 3 L, four neck flask under nitrogen atmosphere was charged with N-vinyl formamide (66.2 g, 0.946 mol) and dry THF (400 mL). BF 3 Et 2 O (239 mL, 1.9 mol) were added dropwise at −5° C. to the milky mixture. After 15 minutes Intermediate 1 (150 g, 0.473 mol) in solution in THF (1 L) was added at −5° C. After 2 h, the mixture was slowly and carefully poured in a NaHCO 3 saturated solution (5 L). Ethyl acetate (2 L) was added and the mixture was transferred to a separating funnel. The organic layer was separated and was washed 1×200 mL H 2 O, 1×200 mL brine and dried (Na 2 SO 4 ). The mixture was filtered and the solids washed 1×50 mL ethyl acetate. The filtrate was concentrated progressively until a precipitate appeared and the mixture cooled in an ice bath during 2 h. The precipitate was filtered through a Buchner funnel, and washed with 2×100 mL i-Pr 2 O to deliver the title compound as a solid (71 g, 56%).
LC/MS: (Method E), m/z 269 and 271 [M+H] + , Rt=2.29 min; 1H NMR (300 MHz, CHLOROFORM-d) δ ppm 0.98 (d, 3H) 1.24 (q, 1H) 2.04 (ddd, 1H) 3.33 (m, 1H) 5.17 (m, 1H) 5.45 (m, 1H) 6.15 (d, 1H) 6.88 (dd, 1H) 7.00 (d, 1H) 8.11 (s, 1H)
Intermediate 3
[1-acetyl-6-bromo-2-methyl-1,2,3,4-tetrahydro-4-quinolinyl]formamide
Acetyl chloride (21 mL, 0.29 mol) is added dropwise at 0° C. to a solution of Intermediate 2 (71 g, 0.26 mol) in a mixture of DCM (1 L) and pyridine (350 mL). After stirring 2 hours at 0° C. the mixture is poured into a mixture of crushed ice (2 kg) and concentrated HCl (450 mL). The product is extracted with DCM (1 L) washed with brine and dried over Na 2 SO 4 . Concentration under vacuo afforded the expected product as an off white solid (82 g, 100%).
1H NMR (300 MHz, CHLOROFORM-d) δ ppm 0.98 (d, 3H) 1.15 (m, 1H) 1.95 (s, 3H) 2.4 (m, 1H) 4.7 (m, 1H) 4.85 (m, 1H) 5.8 (br d, 1H) 6.85 (d, 1H) 7.15 (s, 1H) 7.25 (d, 1H) 8.2 (s, 1H)
Intermediate 4
Methyl 4-[1-acetyl-4-(formylamino)-2-methyl-1,2,3,4-tetrahydro-6-quinolinyl]benzoate
To a suspension of Intermediate 3 (1-acetyl-6-bromo-2-methyl-1,2,3,4-tetrahydro-4-quinolinyl)formamide (62.24 g) in DME (600 ml) was added palladium tetrakis (11.56 g) at room temperature. After 10 min of stirring, were added {4-[(methyloxy)carbonyl]phenyl}boronic acid (54 g) and a 2N solution of Na 2 CO 3 (300 mL) and the mixture was stirred heated to reflux for 16 h. The mixture was concentrated under reduced pressure. After addition of 200 ml of DCM to the residue, the product precipitated, it was filtered and washed with water (3*100 mL). To remove the rest of the water, the solid was washed with isopropyl ether (100 ml), the solid was then added to 220 ml of warm isopropyl ether and the resulting mixture was left in the sonicator. The solid was filtered off and dried to afford the title compound as a beige solid (64.7 g)
LCMS (Method E) Rt 2.58 MH+ 367
Intermediate 5
Methyl 4-(1-acetyl-4-amino-2-methyl-1,2,3,4-tetrahydro-6-quinolinyl)benzoate
A suspension of Intermediate 4 (20.0 g) in methanol (400 mL) was refluxed, then treated with HCl 6N (18 mL). The resulting mixture was refluxed for 2 h. The suspension was filtered off on whatman and the filtrate was concentrated until dryness. Acetone (70 mL) was added to the residue, the solid was filtered off and dried. The resulting salt in ethyl acetate (300 mL) was treated with NaOH 1N (100 ml). Aqueous and organic layers were separated. Aqueous layer was extracted with CH 2 Cl 2 /MeOH 9:1 (300 mL). The organic layers were combined, dried and concentrated until dryness to give the title compound as a white solid (13.83 g). LCMS (Method E) Rt 2.51 MH+ 339
Intermediate 6
(2S,3S)-2,3-bis[(phenylcarbonyl)oxy]butanedioic acid-methyl 4-(1-acetyl-4-amino-2-methyl-1,2,3,4-tetrahydro-6-quinolinyl)benzoate (1:2)
A mixture of the racemic amine Intermediate 5 (185 g,) in EtOH (600 mL) and L-(+)-lactic acid (20% in water, 450 mL) was heated to reflux during 30 minutes. After concentration under reduced pressure hexane (300 mL) was added to the residue and the resulting mixture heated to reflux 10 min. The mixture was allowed to settle and the hexane phase was discarded. The remaining paste was taken up with Et 2 O (300 mL), heated to reflux during 10 minutes and allowed to settle. The Et 2 O phase was discarded and the resulting paste once again was treated with hexane (200 mL), heated to reflux and allowed to settle. The hexane phase was discarded and EtOAc (2.3 L) was added to the remaining paste. The mixture was heated to reflux and allowed to stand at room temperature for 16 hours. The precipitate was filtered and washed with EtOAc (200 mL). The filtrate was made basic with addition of Na 2 CO 3 and the resulting free amino was extracted with EtOAc (3×1000 mL), washed with water, dried over Na 2 SO 4 and concentrated under reduced pressure. The resulting free amino (95 g) in solution in THF (950 mL) was treated with L(−)-dibenzoyltartaric acid (50.3 g, 0.14 mol) and heated to reflux 30 minutes. The resulting precipitate was allowed to stand at room temperature during 16 hours and then was filtered and washed with THF (200 ml). An HPLC monitoring of a neutralised aliquot indicated a 95.6% ee of the expected amine enantiomer. Recrystallisation of the tartaric salt in EtOH (1 L) afforded the title compound (95 g) as a single diastereomer salt.
mp: 196° C. 1H NMR (300 MHz, DMSO-d6) δ ppm 0.95 (d, 3H) 1.15 (m, 1H) 2.05 (s, 3H) 2.55 (m, 1H) 3.85 (s, 3H) 4.0 (m, 1H) 4.55 (m, 1H) 5.7 (s, 1H, CH tartaric) 7.4 (m, 3H) 7.6 (m, 2H) 7.85 (m, 3H), 7.95 (m, 4H).
Intermediate 7
Methyl 4-[(2S,4R)-1-acetyl-4-amino-2-methyl-1,2,3,4-tetrahydro-6-quinolinyl]benzoate
A mixture of Intermediate 6 (121 g) in DCM (3 L) was made basic with addition of an aqueous solution of Na 2 CO 3 . The resulting free amine was extracted with DCM (2 L) washed with water and dried over Na 2 SO 4 to deliver the title compound as an off white solid (79 g).
1H NMR (300 MHz, CHLOROFORM-d) δ ppm 1.15 (m, 4H) 1.7 (m, 2H) 2.15 (s, 3H) 2.6 (m, 1H) 3.8 (dd, 1H), 3.95 (s, 3H) 4.85 (m, 1H) 7.2 (d, 1H) 7.55 (d, 1H) 7.7 (d, 2H), 7.8 (s, 1H) 8.1 (d, 2H) [α] D =+333.8 (c=0.985 g/cl, EtOH).
The title compound eluted at 18.57 min by HPLC as the second peak using a CHIRACEL OD (250×4.6 mm 10 μm) column with hexane/ethanol 80/20 as the mobile phase. A 1 ml/mn flow rate was applied and 10 μL of sample prepared with the dilution of 1 mg of the title compound in 1 ml of eluent was injected. Detection of the compound was carried out with both 210 and 254 nM UV wavelengths. The other enantiomer came off at 12.8 min.
Intermediate 8
Methyl 4-{(2S,4R)-1-acetyl-4-[(4-chlorophenyl)amino]-2-methyl-1,2,3,4-tetrahydro-6-quinolinyl}benzoate
To a flask charged with the Intermediate 7 (800 mg, 2.4 mmol) in toluene (20 mL) was added 4-chlorobromobenzene (501 mg, 2.6 mmol), Pd 2 (dba) 3 (87 mg, 0.09 mmol), NaO t Bu (319 mg, 3.3 mmol) and 2′-(dicyclohexylphosphanyl)-N,N-dimethyl-2-biphenylamine (74 mg, 0.19 mmol). The resulting mixture was stirred to 80° C. during 16 hours and 3 additional hours at reflux. The mixture was poured into water and was made acidic upon addition of 1N HCl. Extraction was carried out with EtOAc (2×75 ml) and the organic layers were washed with water and dried over Na 2 SO4. After filtration, concentration under reduced pressure and purification by column chromatography eluting with C 6 H 12 /EtOAc:80/20 the title compound was obtained as a white solid (350 mg).
1H NMR (300 MHz, CHLOROFORM-d) δ ppm 1.2 (d, 3H) 1.35 (m, 1H) 2.25 (s, 3H) 2.7 (m, 1H) 3.95 (s, 3H), 4.25 (m, 1H) 4.95 (m, 1H) 6.6 (d, 2H) 7.15 (d, 2H) 7.25 (s, 1H) 7.55 (m, 4H), 8.1 (d, 2H) LC/MS (Method D): m/z 449 [M+H] + and 447 [M−H] − Rt=3.67 min. [α] D =+326 (c=0.98 g/cl, EtOH)
The title compound eluted at 22.58 min by HPLC as the second peak using a CHIRACEL OD (250×4.6 mm 10 μm) column with hexane/ethanol 90/10 as the mobile phase. A 1 ml/mn flow rate was applied and 10 μL of sample prepared with the dilution of 1 mg of the title compound in 1 ml of eluent was injected. Detection of the compound was carried out with both 210 and 254 nM UV wavelengths. The other enantiomer came off at 15.46 min.
Compound (II)
4-{(2S,4R)-1-acetyl-4-[(4-chlorophenyl)amino]-2-methyl-1,2,3,4-tetrahydro-6-quinolinyl}benzoic acid
A solution of Intermediate 8 (320 mg, 0.73 mmol) in EtOH (10 ml) and 1N NaOH (1.5 ml, 1.5 mmol) was heated to reflux. After 1 hour a tlc monitoring indicated the completion of the reaction. The crude mixture was evaporated to dryness and the residue taken up in water (10 mL). Acidification of the mixture at pH=3 was carried out by addition of a 1N HCl solution. The organic materials were extracted with EtOAc (3×25 mL) and the organic phase combined and washed with brine and dried over Na 2 SO 4 . After concentration under vacuo the residue was taken up in a DCM/hexane mixture to give a red solid after filtration. The compound was recrystallised in EtOAC, filtered and washed with i-Pr 2 O. The resulting white powder was solubilised in MeOH/H 2 O, concentrated to dryness and taken up with H 2 O. Finally filtration of the precipitate afforded the title compound as a white powder (147 mg), mp: 275° C.
HRMS calculated for C 25 H 23 N 2 O 3 Cl (M−H) − 433.1319. Found: 433.1299. Rt: 2.21 min. 1H NMR (300 MHz, CHLOROFORM-d) δ ppm 1.2 (d, 3H) 1.35 (m, 1H) 2.3 (s, 3H) 2.7 (m, 1H) 4.25 (dd, 1H) 4.95 (m, 1H) 6.65 (d, 2H) 7.15 (d, 2H) 7.25 (s, 1H) 7.55 (m, 4H), 8.15 (d, 2H)
[α] D =+395 (c=0.96 g/cl, EtOH) measured at the EtOAc recrystallisation stage.
The title compound eluted at 4.51 min by HPLC as the first peak using a Chiralpak IA (250×4.6 mm 5 μm) column with tert-butyl methyl oxide (MTBE) +0.1% TFA/Ethanol:90/10 as the mobile phase. A 1 ml/mn flow rate was applied and 10 μL of sample prepared with the dilution of 1 mg of the title compound in 1 ml of eluent was injected. Detection of the compound was carried out with both 210 and 254 nM UV wavelengths. The other enantiomer came off at 5.92 min.
Compound (III)
1-Acetyl-2-methyl-1,2,3,4-tetrahydroquinoline
2-Methyl-1,2,3,4-tetrahydroquinoline (216 mg, 1.469 mmol, available from TCI), was measured into a reaction test tube and acetic anhydride (0.139 ml, 1.469 mmol) was added and left to stir overnight. LCMS analysis showed the reaction had gone to completion. The crude product was purified by MDAP to give the desired compound (677 mg)
LCMS (Method B). RT 0.93, MH+ 190
Intermediate 9
1-methylethyl (2E)-2-butenoylcarbamate
Isopropyl carbamate (30 g, 291 mmol, available from TCI) was charged to a 3 L Lara vessel and dry Tetrahydrofuran (THF) (150 ml) added. (2E)-2-butenoyl chloride (31.2 ml, 326 mmol, available from Aldrich) was added under Nitrogen and the jacket cooled to −30° C. When the solution temperature reached −17° C. 1M Lithium tert-butoxide (655 ml, 655 mmol) was added by peristaltic pump over 2 hours, keeping the reaction temperature between −10° C. and −18° C. Once the addition was complete the mixture was complete the mixture was stirred for 30 mins and brought to 0° C. Diethyl ether (450 ml) and 1M HCl (375 ml) were added and the mixture brought to 20° C. with vigourous stirring. The stirring was stopped, the layers allowed to separate and the aqueous layer run off. Brine (375 ml) was added and the mixture stirred vigourously. The stirring was stopped, the layers allowed to separate and the aqueous layer run off. The organic layer was dried (magnesium sulfate), filtered and evaporated to a brown oil (60 g). The mixture was loaded on to a 40+M Biotage silica column and eluted with DCM:ethyl acetate (1:1 to 0:1, 10 CV). The product containing fractions were evaporated to dryness and loaded on to a 1500 g Redisep Isco silica column and eluted with a gradient of 0 to 40% ethyl acetate in cyclohexane. The clean, product containing fractions were evaporated to an off white solid (15.41 g). LCMS (Method C): Rt=0.68, MH+=172
Intermediate 10
(R-BINAP)ditriflatebis(acetonitrile)palladium(II)
R-(+)-BINAP (6.08 g, 9.76 mmol, available from Avocado) was stirred in Dichloromethane (DCM) (626 ml) and dichlorobis(acetonitrile)palladium (II) (2.5 g, 9.64 mmol, available from Aldrich) added. The mixture was stirred under Nitrogen for 30 mins, the suspension had not become a solution and more DCM (100 ml) was added. The mixture was stirred for a further 30 mins and Silver triflate (5.00 g, 19.47 mmol, available from Aldrich) dissolved in Acetonitrile (250 ml) was added. The mixture changed from an orange cloudy suspension to a yellow suspension. The mixture was stirred for 1 hour, filtered through celite and evaporated to an orange solid. The residue was dried under vacuum (at approximately 14 mbar) at room temperature over the weekend to give the desired product (10.69 g).
1H NMR (400 MHz, MeCN-d3) δ ppm 2.0 (s, 6H), 6.7 (d, 2H), 6.9 (br m, 4H), 7.1 (br t, 2H), 7.2 (t, 2H), 7.5-7.9 (m, 22H)
Intermediate 11
(3S)-3-(phenylamino)butanenitrile
(3S)-3-aminobutanenitrile (8.6 g, 102 mmol, may be prepared as described in PCT Int. Appl., 2005100321), bromobenzene (16.16 ml, 153 mmol) and cesium carbonate (50.0 g, 153 mmol) were combined in Toluene (100 ml) under nitrogen were stirred for 45 mins. Phenylboronic acid (0.187 g, 1.534 mmol, Aldrich), palladium(II) acetate (0.188 g, 0.837 mmol, available from Aldrich) and 2-dicyclohexylphosphino-2′-(N,N-dimethylamino)biphenyl (0.443 g, 1.125 mmol, available from Aldrich) were combined in Tetrahydrofuran (THF) (6.67 ml) under nitrogen and stirred for 45 mins. The THF solution was added to the toluene solution and the reaction heated to 80° C. overnight. The reaction mixture was cooled and partitioned between EtOAc (500 ml) and water (300 ml). The aqueous layer was reextracted with EtOAc (200 ml). The combined organic layers were washed with water and brine (500 ml each) and then dried with Na2SO4, filtered and concentrated to yield an orange oil. The crude product was taken up in the minimum of DCM, applied to a 330 g Companion XL column and eluted with 5% Ethyl Acetate in cyclohexane for 1 CV then 5-30% Ethyl Acetate over 12 CV then held at 30% for 3 CV; UV collection; 450 ml fractions. The product was isolated as an off-white solid (11.3526 g).
LCMS (Method B): Rt=0.87, MH+=161
Intermediate 12
(3S)-3-[(4-bromophenyl)amino]butanenitrile
(3S)-3-(phenylamino)butanenitrile (for a preparation see Intermediate 11)(11.3526 g, 70.9 mmol) was taken up in N,N-Dimethylformamide (DMF) (200 mL) under nitrogen and cooled in an ice-bath. NBS (12.61 g, 70.9 mmol) was added and the reaction stirred. After 20 mins, the reaction was partitioned between EtOAc (1000 ml) and water (500 ml). The organic layer was washed with 2M NaOH×2, water and brine (500 ml each) and then dried with Na2SO4, filtered and concentrated to yield the product as a cream solid (17.3 g). LCMS (Method B): Rt=1.05, MH+=239
Intermediate 13
(3S)-3-[(4-bromophenyl)amino]butanamide
(3S)-3-[(4-bromophenyl)amino]butanenitrile (for a preparation see Intermediate 12)(17.3 g, 72.4 mmol) was taken up in Toluene (500 ml) and H2SO4 (19.28 ml, 362 mmol) added. The biphasic mixture was stirred at 60° C. After two hours, only a small amount of SM remained by LCMS so the reaction was diluted with water (500 ml) and the phases separated. The aqueous phase was basified with 10N NaOH and extracted with EtOAc (2×750 ml). The combined organics were dried with Na2SO4, filtered and concentrated to yield the product as a cream solid (17.5 g). LCMS (Method B): Rt=0.77, MH+=257
Intermediate 14
1-methylethyl {(3S)-3-[(4-bromophenyl)amino]butanoyl}carbamate
(3S)-3-[(4-bromophenyl)amino]butanamide (for a preparation see Intermediate 13, 24.9 g, 97 mmol) was taken up in Ethyl acetate (850 mL) and cooled to <−9° C. (internal). Isopropyl chloroformate (116 mL, 116 mmol, Aldrich) was added followed by slow addition of Lithium tert-butoxide (18.61 g, 232 mmol) in Tetrahydrofuran (THF) (232 mL) keeping the temperature below 0° C. The reaction was stirred for 30 mins then checked by LCMS which showed a complete reaction. The mixture was partitioned between EtOAc (1000 ml) and 2N HCl (2000 ml). The organic layer was washed with brine (2000 ml) and then dried with Na2SO4, filtered and concentrated to yield the product as a brown oil (17.9 g)
LCMS (Method B): Rt=1.09, MH+=343
Alternative Method
1-methylethyl (2E)-2-butenoylcarbamate (Intermediate 9, 9.38 g, 54.8 mmol) was stirred in Toluene (281 ml) under nitrogen and (R-BINAP)ditriflatebis(acetonitrile)palladium(II) (Intermediate 10, 3.35 g, 3.01 mmol) added. The catalyst formed a gummy ball, the solution turned to an opaque yellow mixture and was stirred for 20 mins. 4-bromoaniline (14.14 g, 82 mmol) was added, the solution turned a clear light brown and the gummy catalyst dissolved further. The mixture was stirred overnight,
Similarly a second batch of 1-methylethyl (2E)-2-butenoylcarbamate (Intermediate 9, 8.51 g, 49.7 mmol) was stirred in Toluene (255 ml) under nitrogen and (R-BINAP)ditriflatebis(acetonitrile)palladium(II) (3.04 g, 2.73 mmol) added. The catalyst formed a gummy ball, the solution turned to an opaque yellow mixture and was stirred for 20 mins. 4-bromoaniline (12.83 g, 74.6 mmol) was added, the solution turned a clear light brown and the gummy catalyst dissolved further. The mixture was stirred overnight. The two reaction mixtures were combined and loaded on to a 1.5 kg Isco silica Redisep column. The column was eluted with DCM:MeOH (0%->0.5%, 19 CV). The clean, product containing fractions were evaporated to a pale brown oil. The mixture was dried in a vaccum oven overnight at 40° C. to give a white solid (24.2 g, 67% overall).
LCMS (Method C): Rt=0.91, MH+=343. ee=92%.
Intermediate 15
1-methylethyl [(2S,4R)-6-bromo-2-methyl-1,2,3,4-tetrahydro-4-quinolinyl]carbamate
1-methylethyl {(3S)-3-[(4-bromophenyl)amino]butanoyl}carbamate (for a preparation see Intermediate 14)(17.9 g, 52.2 mmol) was taken up in Ethanol (150 mL) and cooled to below −10° C. (internal) in a CO2/acetone bath. NaBH4 (1.381 g, 36.5 mmol) was added followed by Magnesium Chloride hexahydrate (11.35 g, 55.8 mmol) in Water (25 mL) keeping the temperature below −5° C. The mixture was allowed to stir at <0° C. for 1 hr then warmed to RT and stirred for an hour. The resulting thick suspension was poured into a mixture of citric acid (25.05 g, 130 mmol), HCl (205 mL, 205 mmol) and Dichloromethane (DCM) (205 mL). The biphasic mixture was stirred at RT for 1 hr. LCMS showed no SM remained so the organic layer was extracted and dried with Na2SO4, filtered and concentrated to yield the product as a light brown solid (14.1 g). LCMS (Method B): Rt=1.13, MH+=327
Intermediate 16
1-methylethyl [(2S,4R)-1-acetyl-6-bromo-2-methyl-1,2,3,4-tetrahydro-4-quinolinyl]carbamate
1-methylethyl [(2S,4R)-6-bromo-2-methyl-1,2,3,4-tetrahydro-4-quinolinyl]carbamate (for a preparation see Intermediate 15)(14.1 g, 43.1 mmol) was taken up in Dichloromethane (DCM) (400 mL) under nitrogen at RT. Pyridine (10.46 mL, 129 mmol) then Acetyl chloride (4.60 mL, 64.6 mmol) were added and the reaction stirred overnight. LCMS showed a complete reaction so it was partitioned between EtOAc (2000 ml) and sat. NaHCO 3 (800 ml). The organic layer was extracted and washed with water and brine (1500 ml each) and then dried with Na 2 SO 4 , filtered and concentrated to yield a purple solid. The crude product was taken up in the minimum of DCM and applied to a 330 g Companion XL column and eluted with a gradient of 12-63% Ethyl Acetate in cyclohexane. Product containing fractions were collected as an off-white solid (12.37 g).
LCMS (Method B): Rt=1.03, MH+=369 [alpha]D=+281.1025° (T=20.7° C., 10 mm cell, c=0.508 g/100 ml, ethanol).
Intermediate 17
1-methylethyl [(2S,4R)-1-acetyl-6-(4-formylphenyl)-2-methyl-1,2,3,4-tetrahydro-4-quinolinyl]carbamate
1-methylethyl [(2S,4R)-1-acetyl-6-bromo-2-methyl-1,2,3,4-tetrahydro-4-quinolinyl]carbamate (for a preparation see Intermediate 16)(1 g, 2.71 mmol), (4-formylphenyl)boronic acid (0.487 g, 3.25 mmol, available from Aldrich), Pd(Ph 3 P) 4 , (0.156 g, 0.135 mmol) and potassium carbonate (0.487 g, 3.52 mmol) were combined in dry ethanol (7 ml) and dry toluene (7.00 ml) and the reaction mixture was de-gassed for 10 mins. The reaction mixture was heated at 85° C. overnight. The reaction mixture was allowed to cool to r.t. and concentrated. The crude reaction mixture was partitioned between water (15 ml) and ethyl acetate (5 ml) and stirred at r.t. for 30 mins. A light grey solid precipitated out and was filtered off, washed with water (5 ml) and dried in a vacuum oven to give 854 mg of grey solid. LCMS (Method B): Rt=1.00, MH+=395
Compound (IV)
1-methylethyl ((2S,4R)-1-acetyl-2-methyl-6-{4-[(methylamino)methyl]pheny}-1,2,3,4-tetrahydro-4-quinolinyl)carbamate
1-methylethyl [(2S,4R)-1-acetyl-6-(4-formylphenyl)-2-methyl-1,2,3,4-tetrahydro-4-quinolinyl]carbamate (for a preparation see Intermediate 17)(100 mg, 0.254 mmol) was dissolved in Methanol (3 mL) and 2M methylamine in THF (0.254 mL, 0.507 mmol) was added. The yellow solution was stirred under nitrogen at room temperature for 135 minutes at which point sodium borohydride (15.35 mg, 0.406 mmol) was added. The reaction was stirred for 1 h then left sitting overnight. The reaction was quenched with sat. aqueous sodium bicarbonate solution (1 mL) and EtOAc (8 mL) was added. A white solid was filtered off (bond elut reservoir) and found to be the desired product (34 mg). The filtrate was partitioned and the organic layer dried. Concentration of the organic layer gave 67 mg of a colourless residue which was applied to a silica 12+S Biotage column and purified eluting with a gradient of 1-5% methanolic ammonia in DCM. Concentration of the product containing fractions gave another batch of the desired product (52 mg).
LCMS (Method C): Rt 0.71, MH+=410 1H NMR (CHLOROFORM-d, 600 MHz): δ (ppm) 7.55 (d, J=8.1 Hz, 2H), 7.49 (d, J=7.9 Hz, 1H), 7.45 (br. s., 1H), 7.41 (d, J=7.9 Hz, 2H), 7.18 (d, J=7.3 Hz, 1H), 4.52-5.08 (m, 4H), 3.81 (s, 2H), 2.62 (ddd, J=12.5, 8.3, 4.5 Hz, 1H), 2.50 (s, 3H), 2.17 (s, 3H), 1.21-1.37 (m, 7H), 1.18 (d, J=6.4 Hz, 3H)
Reference compound A: 2-methyl-6-(methyloxy)-4H-3,1-benzoxazin-4-one
A solution of 5-methoxyanthranilic acid (Lancaster) (41.8 g, 0.25 mol) was refluxed in acetic anhydride (230 mL) for 3.5 h before being concentrated under reduced pressure. The crude compound was then concentrated twice in the presence of toluene before being filtered and washed twice with ether to yield to the title compound (33.7 g, 71% yield) as a brown solid; LC/MS (Method D): m/z 192 [M+H] + , Rt 1.69 min.
Reference compound B: [2-amino-5-(methyloxy)phenyl](4-chlorophenyl)methanone
To a solution of 2-methyl-6-(methyloxy)-4H-3,1-benzoxazin-4-one (for a preparation see Reference compound A) (40.0 g, 0.21 mol) in a toluene/ether (2/1) mixture (760 mL) at 0° C. was added dropwise a solution of 4-chlorophenylmagnesium bromide (170 mL, 1M in Et 2 O, 0.17 mol). The reaction mixture was allowed to warm to room temperature and stirred for 1 h before being quenched with 1N HCl (200 mL). The aqueous layer was extracted with EtOAc (3×150 mL) and the combined organics were washed with brine (100 mL), dried over Na 2 SO 4 , filtered and concentrated under reduced pressure. The crude compound was then dissolved in EtOH (400 mL) and 6N HCl (160 mL) was added. The reaction mixture was refluxed for 2 h before being concentrated to one-third in volume. The resulting solid was filtered and washed twice with ether before being suspended in EtOAc and neutralised with 1N NaOH. The aqueous layer was extracted with EtOAc (3×150 mL) and the combined organics were washed with brine (150 mL), dried over Na 2 SO 4 , filtered and concentrated under reduced pressure. The title compound was obtained as a yellow solid (39 g, 88% yield); LC/MS (Method D): m/z 262 [M+H]+, Rt 2.57 min.
Reference Compound C: Methyl N 1 -[2-[(4-chlorophenyl)carbonyl]-4-(methyloxy)phenyl]-N 2 -{[(9H-fluoren-9-ylmethyl)oxy]carbonyl}-L-α-asparaginate
Methyl N-{[(9H-fluoren-9-ylmethyl)oxy]carbonyl}-L-α-aspartyl chloride (Int. J. Peptide Protein Res. 1992, 40, 13-18) (93 g, 0.24 mol) was dissolved in CHCl 3 (270 mL) and [2-amino-5-(methyloxy)phenyl](4-chlorophenyl)methanone (53 g, 0.2 mol) (for a preparation see Reference compound B) was added. The resulting mixture was stirred at 60° C. for 1 h before being cooled and concentrated at 60% in volume. Ether was added at 0° C. and the resulting precipitate was filtered and discarded. The filtrate was concentrated under reduced pressure and used without further purification.
Reference compound D: Methyl [(3S)-5-(4-chlorophenyl)-7-(methyloxy)-2-oxo-2,3-dihydro-1H-1,4-benzodiazepin-3-yl]acetate
To a solution of methyl N1-[2-[(4-chlorophenyl)carbonyl]-4-(methyloxy)phenyl]-N2-{[(9H-fluoren-9-ylmethyl)oxy]carbonyl}-L-α-asparaginate (for a preparation see Reference compound C) (assumed 0.2 mol) in DCM (500 mL) was added Et 3 N (500 mL, 3.65 mol) and the resulting mixture was refluxed for 24 h before being concentrated. The resulting crude amine was dissolved in 1,2-DCE (1.5 L) and AcOH (104 mL, 1.8 mol) was added carefully. The reaction mixture was then stirred at 60° C. for 2 h before being concentrated in vacuo and dissolved in DCM. The organic layer was washed with 1N HCl and the aqueous layer was extracted with DCM (×3). The combined organic layers were washed twice with water, and brine, dried over Na 2 SO 4 , filtered and concentrated under reduced pressure. The crude solid was recrystallised in MeCN leading to the title compound (51 g) as a pale yellow solid. The filtrate could be concentrated and recrystallised in MeCN to give to another 10 g of the desired product R f =0.34 (DCM/MeOH: 95/5).
HRMS (M+H) + calculated for C 19 H 18 35 ClN 2 O 4 373.0955. Found 373.0957.
Reference compound E: Methyl [(3S)-5-(4-chlorophenyl)-7-(methyloxy)-2-thioxo-2,3-dihydro-1H-1,4-benzodiazepin-3-yl]acetate
A suspension of P 4 S 10 (36.1 g, 81.1 mmol) and Na 2 CO 3 (8.6 g, 81.1 mmol) in 1,2-DCE (700 mL) at room temperature was stirred for 2 h before methyl [(3S)-5-(4-chlorophenyl)-7-(methyloxy)-2-oxo-2,3-dihydro-1H-1,4-benzodiazepin-3-yl]acetate (for a preparation see Reference compound D) (16.8 g, 45.1 mmol) was added. The resulting mixture was stirred at 70° C. for 2 h before being cooled and filtered. The solid was washed twice with DCM and the filtrate washed with sat. NaHCO 3 and brine. The organic layer was dried over Na 2 SO 4 , filtered and concentrated under reduced pressure. The crude product was purified by flash-chromatography on silica gel (DCM/MeOH: 99/1) to afford the title compound (17.2 g, 98% yield) as a yellowish solid. LC/MS (Method D): m/z 389 [M( 35 Cl)+H] + , Rt 2.64 min
HRMS (M+H) + calculated for C 19 H 18 35 ClN 2 O 3 S 389.0727. Found 389.0714.
Reference compound F: Methyl [(3S)-2-[(1Z)-2-acetylhydrazino]-5-(4-chlorophenyl)-7-(methyloxy)-3H-1,4-benzodiazepin-3-yl]acetate
To a suspension of methyl [(3S)-5-(4-chlorophenyl)-7-(methyloxy)-2-thioxo-2,3-dihydro-1H-1,4-benzodiazepin-3-yl]acetate (for a preparation see Reference compound E (9.0 g, 23.2 mmol) in THF (300 mL) at 0° C. was added hydrazine monohydrate (3.4 mL, 69.6 mmol) dropwise. The reaction mixture was stirred for 5 h between 5° C. and 15° C. before being cooled at 0° C. Et 3 N (9.7 mL, 69.6 mmol) was then added slowly and acetyl chloride (7.95 mL, 69.6 mmol) was added dropwise. The mixture was then allowed to warm to room temperature for 16 h before being concentrated under reduced pressure. The crude product was dissolved in DCM and washed with water. The organic layer was dried over Na 2 SO 4 , filtered and concentrated in vacuo to give the crude title compound (9.7 g, 98% yield) which was used without further purification. R f =0.49 (DCM/MeOH: 90/10).
Reference compound G: Methyl [(4S)-6-(4-chlorophenyl)-1-methyl-8-(methyloxy)-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl]acetate
The crude methyl [(3S)-2-[(1Z)-2-acetylhydrazino]-5-(4-chlorophenyl)-7-(methyloxy)-3H-1,4-benzodiazepin-3-yl]acetate (for a preparation see Reference compound F) (assumed 9.7 g) was suspended in THF (100 ml) and AcOH (60 mL) was added at room temperature. The reaction mixture was stirred at this temperature for 2 days before being concentrated under reduced pressure. The crude solid was triturated in i-Pr 2 O and filtered to give the title compound (8.7 g, 91% over 3 steps) as an off-white solid.
HRMS (M+H) + calculated for C 21 H 20 ClN 4 O 3 411.1229. Found 411.1245.
Reference compound H: [(4S)-6-(4-Chlorophenyl)-1-methyl-8-(methyloxy)-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl]acetic acid
To a solution of Methyl [(4S)-6-(4-chlorophenyl)-1-methyl-8-(methyloxy)-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl]acetate (for a preparation see Reference compound G) (7.4 g, 18.1 mmol) in THF (130 mL) at room temperature was added 1N NaOH (36.2 mL, 36.2 mmol). The reaction mixture was stirred at this temperature for 5 h before being quenched with 1N HCl (36.2 mL) and concentrated in vacuo. Water is then added and the aqueous layer was extracted with DCM (×3) and the combined organic layers were dried over Na 2 SO 4 , filtered and concentrated under reduced pressure to give the title compound (7 g, 98% yield) as a pale yellow solid.
Reference compound I: 1,1-dimethylethyl [5-({[(4S)-6-(4-chlorophenyl)-1-methyl-8-(methyloxy)-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl]acetyl}amino)pentyl]carbamate
A mixture of [(4S)-6-(4-chlorophenyl)-1-methyl-8-(methyloxy)-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl]acetic acid (for a preparation see Reference compound H) (1.0 g, 2.5 mmol), HATU (1.9 g, 5 mmol) and DIPEA (0.88 ml, 5 mmol) was stirred for 80 minutes at room temperature, to this was added 1,1-dimethylethyl (4-aminobutyl)carbamate (1.05 ml, 5.0 mmol, available from Aldrich). The reaction mixture was stirred at room temperature for 2 h before it was concentrated. The residue was taken up in dichloromethane and washed with 1N HCl. The aqueous layer was extracted with dichloromethane twice. Organic layer was washed with 1N sodium hydroxide, followed by a saturated solution of sodium chloride, dried over sodium sulphate and concentrated. The residue was purified by flash-chromatography on silica using dichloromethane/methanol 95/5 to give the title compound as a yellow solid (1.2 g). LC/MS (Method D): rt=3.04 min.
Reference compound J: N-(5-aminopentyl)-2-[(4S)-6-(4-chlorophenyl)-1-methyl-8-(methyloxy)-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl]acetamide trifluoroacetate
To a solution of 1,1-dimethylethyl [5-({[(4S)-6-(4-chlorophenyl)-1-methyl-8-(methyloxy)-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl]acetyl}amino)pentyl]carbamate (for a preparation see Reference compound I) (0.2 g, 0.34 mmol) in dichloromethane (3 ml) was added trifluoroacetic acid (0.053 ml, 0.68 mmol) dropwise at 0° C. The reaction mixture was stirred for 3 h from 0° C. to room temperature. The reaction mixture was concentrated to dryness to afford the title compound as a hygroscopic yellow oil (200 mg)
LC/MS (Method D): rt=2.33 min. HRMS (M+H) + calculated for C 25 H 29 ClN 6 O 2 481.2119. Found 481.2162.
Reference compound K: Mixture of 5- and 6-isomers of Alexa Fluor 488-N-(5-aminopentyl)-2-[(4S)-6-(4-chlorophenyl)-1-methyl-8-(methyloxy)-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl]acetamide
N-(5-aminopentyl)-2-[(4S)-6-(4-chlorophenyl)-1-methyl-8-(methyloxy)-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl]acetamide trifluoroacetate (for a preparation see Reference compound J)(7.65 mg, 0.013 mmol) was dissolved in N,N-Dimethylformamide (DMF) (300 μl) and added to Alexa Fluor 488 carboxylic acid succinimidyl ester (5 mg, 7.77 μmol, mixture of 5 and 6 isomers, available from Invitrogen, product number A-20100) in an Eppendorf centrifuge tube. Hunig's base (7.0 μl, 0.040 mmol) was added and the mixture vortex mixed overnight. After 18 h the reaction mixture was evaporated to dryness and the residue redissolved in DMSO/water (50%, <1 ml total), applied to a preparative Phenomenex Jupiter C18 column and eluted with a gradient of 95% A: 5% B to 100% B (A=0.1% trifluoroacetic acid in water, B=0.1% TFA/90% acetonitrile/10% water) at a flow rate of 10 ml/min over 150 minutes. Impure fractions were combined and re-purified using the same system. Fractions were combined and evaporated to yield the title product (2.8 mg) as a mixture of the 2 regioisomers shown.
LC/MS (Method F): MH+=999, rt=1.88 min.
Biological Test Methods
Fluorescence Anisotropy Binding Assay
The binding of Compounds (I) to (IV) to Bromodomains BRD-2, BRD-3 and BRD-4 was assessed using a Fluorescence Anisotropy Binding Assay.
The Bromodomain protein, fluorescent ligand (Reference compound K see above) and a variable concentration of test compound are incubated together to reach thermodynamic equilibrium under conditions such that in the absence of test compound the fluorescent ligand is significantly (>50%) bound and in the presence of a sufficient concentration of a potent inhibitor the anisotropy of the unbound fluorescent ligand is measurably different from the bound value.
All data was normalized to the mean of 16 high and 16 low control wells on each plate. A four parameter curve fit of the following form was then applied:
y=a +(( b−a )/(1+(10^ x/ 10^ c )^ d )
Where ‘a’ is the minimum, ‘b’ is the Hill slope, ‘c’ is the pIC 50 and ‘d’ is the maximum.
Recombinant Human Bromodomains (BRD-2 (1-473), BRD-3 (1-435) and BRD-4 (1-477)) were expressed in E. coli cells (in pET15b vector) with a six-His tag at the N-terminal. The His-tagged Bromodomain was extracted from E. coli cells using 0.1 mg/ml lysozyme and sonication. The Bromodomain was then purified by affinity chromatography on a HisTRAP HP column, eluting with a linear 10-500 mM Imidazole gradient, over 20 Cv. Further purification was completed by Superdex 200 prep grade size exclusion column. Purified protein was stored at −80 C in 20 mM HEPES pH 7.5 and 100 mM NaCl.
Protocol for Bromodomain BRD-2: All components were dissolved in buffer composition of 50 mM HEPES pH7.4, 150 mm NaCl and 0.5 mM CHAPS with final concentrations of BRD-2, 75 nM, fluorescent ligand 5 nM. 10 μl of this reaction mixture was added using a micro multidrop to wells containing 100 nl of various concentrations of test compound or DMSO vehicle (1% final) in Greiner 384 well Black low volume microtitre plate and equilibrated in dark 60 mins at room temperature. Fluorescence anisotropy was read in Envision (λex=485 nm, λEM=530 nm; Dichroic −505 nM).
Protocol for Bromodomain BRD-3: All components were dissolved in buffer of composition 50 mM HEPES pH7.4, 150 mm NaCl and 0.5 mM CHAPS with final concentrations of BRD-3 75 nM, fluorescent ligand 5 nM. 10 μl of this reaction mixture was added using a micro multidrop to wells containing 100 nl of various concentrations of test compound or DMSO vehicle (1% final) in Greiner 384 well Black low volume microtitre plate and equilibrated in dark 60 mins at room temperature. Fluorescence anisotropy was read in Envision (λex=485 nm, λEM=530 nm; Dichroic −505 nM).
Protocol for Bromodomain BRD-4: All components were dissolved in buffer of composition 50 mM HEPES pH7.4, 150 mm NaCl and 0.5 mM CHAPS with final concentrations of BRD-4 75 nM, fluorescent ligand 5 nM. 10 μl of this reaction mixture was added using a micro multidrop to wells containing 100 nl of various concentrations of test compound or DMSO vehicle (1% final) in Greiner 384 well Black low volume microtitre plate and equilibrated in dark 60 mins at room temperature. Fluorescence anisotropy was read in Envision (λex=485 nm, λEM=530 nm; Dichroic −505 nM).
Compounds (I), (II) and (IV) had a pIC 50 ≧6.0 in each of the BRD-2, BRD-3 and BRD-4 assays described above.
Compound (III) had a pIC 50 ≦4.3 in each of the BRD-2, BRD-3 and BRD-4 assays described above.
All publications, including but not limited to patents and patent applications, cited in this specification are herein incorporated by reference as if each individual publication were specifically and individually indicated to be incorporated by reference herein as though fully set forth. | A process for the identification of compounds with a molecular weight in the range 100 to 750 which inhibit the binding of the first and/or second bromodomains of human BRD-2 to 4 to acetylated lysine residues of their physiological partner proteins which comprises selecting those compounds which are able to:
a) form a hydrogen bonding interaction in which the compound accepts a hydrogen bond from the sidechain NH2 group of the asparagine residue found at:
BRD-2 BRD-2 BRD-3 BRD-3 BRD-4 BRD-4 BD1 BD2 BD1 BD2 BD1 BD2 ASN156 ASN429 ASN116 ASN391 ASN140 ASN433
or
b) accept a water-mediated hydrogen bond in which the compound accepts a hydrogen bond from a water that is itself hydrogen-bonded to the sidechain hydroxyl of the tyrosine residue found at
BRD-2 BRD-2 BRD-3 BRD-3 BRD-4 BRD-4 BD1 BD2 BD1 BD2 BD1 BD2 TYR113 TYR386 TYR73 TYR348 TYR97 TYR390
and
c) which are also able to form a Van der Waals interaction with a lipophilic binding region of a binding pocket such that one or more heavy atoms of the said compounds lie within a 5 Å range of any of the heavy atoms of the following bromodomain residues which define the binding pocket:
BRD-2 BRD-2 BRD-3 BRD-3 BRD-4 BRD-4 BD1 BD2 BD1 BD2 BD1 BD2 TRP97 TRP370 TRP57 TRP332 TRP81 TRP374 PRO98 PRO371 PRO58 PRO333 PRO82 PRO375 ASP161 ASP434 ASP121 GLU396 ASP145 GLU438 ILE162 VAL435 ILE122 VAL397 ILE146 VAL439 MET165 MET438 MET125 MET400 MET149 MET442
pharmaceutical compositions containing such compounds, and their use in therapy. | 2 |
REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/085,814, filed May 18, 1998.
FIELD OF THE INVENTION
The present invention relates generally to the field of electrical sensors and more particularly to a network based multi-function sensor suitable for sensing motion, temperature and ambient light and which include blinder devices for reducing nuisance tripping of the device.
BACKGROUND OF THE INVENTION
Today, automation systems are being installed in more and more buildings, including both new construction and in structures that are being rebuilt. The incentives for putting automation systems into a building are numerous. High on the list are reduced operating costs, more efficient use of energy, simplified control of building systems, ease of maintenance and of effecting changes to the systems. Facility managers would prefer to install systems that can interoperate amongst each other. Interoperability is defined by different products, devices and systems for different tasks and developed by different manufacturers, can be linked together to form flexible, functional control networks.
An example of a typical automation system includes lighting controls, HVAC systems, security systems, fire alarm systems and motor drives all possibly provided by different manufacturers. It is desirable if these separate disparate systems can communicate and operate with each other.
Prior art automation systems generally comprised closed proprietary equipment supplied by a single manufacturer. With this type of proprietary system, the installation, servicing and future modifications of the component devices in the system were restricted to a single manufacturer's product offering and technical capability. In addition, it was very difficult or impossible to integrate new technology developed by other manufacturers. If technology from other manufactures could be integrated, it was usually too costly to consider.
Thus, it is desirable to create an open control system whereby individual sensors, processors and other components share information among one another. A few of the benefits of using an open system include reduced energy costs, increased number of design options for the facility manager, lower design and installation costs since the need for customized hardware and software is greatly reduced and since star configuration point to point wiring is replaced by shared media and lastly, system startup is quicker and simpler.
In addition, expansion and modification of the system in the future is greatly simplified. New products can be introduced without requiring major system redesign or reprogramming.
An integral part of any automation control system are the sensors and transducers used to gather data on one or more physical parameters such as temperature and motion. It would be desirable if a plurality of sensor functions could be placed in a single device, fit in a standard single wall box opening and be able to communicate with one or more control units, i.e., processing nodes, on the control network.
The number and types of sensors in this device could be many including multiple, dual or singular occupancy and security sensing via means including passive infrared, ultrasonic, RF, audio or sound or active infrared. In addition, other multiple or singular transducers may be employed such as temperature sensor, relative humidity sensor, ambient light sensor, CO sensor, smoke sensor, security sensor, air flow sensors, switches, etc.
The utility of such a multifunction sensor can best be described by an example. In order to minimize the number of unique devices that are installed in a room, it is desirable to have a sensor device reliably perform as many functions as possible as this reduces the wiring costs as well as the number of devices required to be installed on the walls of the room. Additionally, from an aesthetic point of view, architects are under increasing demand by their clients to reduce the number of unique sensor nodes in any given room.
Further, it is also desirable to have these transducers or sensors communicate with a microprocessor or microcontroller that can be used to enhance the application of the transducer. This may be accomplished by providing the necessary A/D functions, including sensitivity and range adjustments of the transducer functions, and also by enabling the sensed information to be communicated over a bus or other media using a suitable protocol.
Further, calibration, either in the field or the factory could be employed to generate either a relative or real absolute temperature reading. Further, the control of any HVAC equipment could be performed either locally at the sensor node or at a remote location. Also, the sensor devices could be used to control the lights in and outside the room and building, control the HVAC control in and outside the room and building, send signals to or control the fire alarm and security alarm systems, etc.
It is also desirable to enable the device to communicate any of the standard protocols already in use such as Echelon LonWorks, CEBus, X10, BACNet, CAN, etc. Some examples of the media include twisted pair, power line carrier, optical fiber, RF, coaxial, etc.
The device thus preferably can transmit data or commands, receive data or commands, activate and switch local or remote loads or control devices, use and/or generate real time or relative readings, be calibrated externally in an automatic self adjusting way, calibrated externally or via an electronic communications link.
Additionally, the device preferably is able to minimize or eliminate effects from its internal circuitry that may interfere with the temperature reading of the temperature sensor. Also, the device preferably has the ability to detect if there are adverse air flows emanating from the mounting hole in the wall or other surface which could cause erroneous temperature and humidity measurements.
It is desirable if the device is mounted in a location that is exposed to the air in the environment of the room or area being monitored. The motion detector transducer and sensor circuit is preferably mounted in a manner such that it is not exposed to (1) the air flow from the environment being monitored and (2) the air flow which may be created when the device is mounted in or on a hole in the wall. Further, the hole in the wall is often created when the device is mounted on a wall in a home or office building. The hole may function to create a chimney effect given the right conditions. It is thus desirable to mount the temperature sensor in a way which offers some shielding or insulation from direct exposure to heating or air ducts as well as any other undesirable heating or cooling sources such as direct sunlight, fans, HVAC ducts, etc.
SUMMARY OF THE INVENTION
The present invention is a multifunction sensor device that provides various transducer functions. In particular, the device comprises a means for performing temperature sensing, ambient light sensing, motion detection, switching functions and a means to put the device in an on, off or auto mode. Such a device has utility in environments such as that found in offices, schools, homes, industrial plants or any other type of automated facility in which sensors are utilized for energy monitoring and control, end user convenience or HVAC control.
Key elements of the present invention include (1) overcoming the difficulty of mounting diverse sensors or transducers within the same device or housing, (2) permitting these various sensors to exist in a single package that can be mounted to a wall in a substantially flush manner and (3) eliminating the requirement of an air flow channel in the device, thus minimizing any adverse effects on the motion detecting element or sensor as well as providing built in partial hysteresis and practical latency.
A prime objective of the present invention is to provide a flush or surface mounted temperature and motion detection sensor in a single device. The device may include additional transducers or sensors and is constructed such that the temperature sensor is neither exposed to the flow of air in a room or area nor in an airflow channel whereby a chimney effect may occur. To avoid these conditions from occurring, the temperature-sensing element is placed in a cavity that is coupled to the environment. Thus, the temperature of the air in the cavity changes via diffusion with the temperature in the surrounding environment. In addition, the temperature sensing element, e.g., passive or active infrared sensor is mounted so as to be shielded from exposure to direct sunlight and so as not to be exposed to a flow of air from the environment being monitored.
Further, the vents provided for the temperature sensing element functions as a baffle to provide hysteresis. The hysteresis provides additional utility for the device in that the temperature sensing element is mounted within, beneath, part of, or on the housing in such a way that the chimney effects due to airflow in the wall or from heating or cooling ducts nearby are reduced or eliminated in a fashion that is similar to a "smoothing" or softening affect and can be adjusted mechanically and/or electronically through hardware or software such that the hysteresis can be "settable" to any achievable value and could even approach zero hysteresis if desired. Note that the temperature sensor module can be incorporated in a flush mount device, wall or surface mount device or ceiling device. Further, since an air channel is not required or used the device can be mounted flush in a single or multiple gang electrical box.
Another objective of the present invention is to provide a means of temperature sensing utilizing multiple technologies including RTD, PRTD, thermisters, digital temperature sensors, PWM sensors, silicon sensors, capacitive and polymer sensors, etc. One or more sensors can be used in the circuits that are coupled to a microprocessor or microcontroller. The sensor is positioned in a modular temperature chamber that permits the temperature sensor to acclimate to the ambient air temperature in the surrounding environment. Access to the temperature sensor is simply achieved by removal of a cover or panel without the need for special tools.
The microcontroller is utilized to provide the capability of transmitting and receiving real time data, relative data and actual discrete data in addition to switching and controlling loads locally or remotely. Data can be sent and received from other devices that are part of the distributed or centralized control system wherein device communicate with each other using standard protocols such as Echelon LonWorks, CEBus, X10, BACNet, CAN, etc. The media utilized may comprise twisted pair, power line carrier, RF, optical fiber, coaxial, etc.
The device also has the capability of self-calibration of the sensors under either local or remote control. For example, if the device is exposed to two different known temperatures, then the equation of a line including the slope and relative offset connecting the two points can be generated. This procedure can be performed once and either actual or relative readings can be calibrated within the operating range of the device. In addition, points can be recorded and used to provide additional accuracy or to extend the range of the temperature sensor. Further, a piece-wise linear equation and look up table can be generated which is used to linearize the accuracy or sensitivity of the temperature sensing element and associated circuitry. In addition, local test resistors or potentiometers can be used to adjust the range, sensitivity or accuracy of the sensor.
Another key element of the device is that the temperature sensor does not have an air flow channel that permits air to circulate through the sensor module housing. Rather, the device has a passive alcove or cavity that acclimates to the ambient air temperature through the process of diffusion. In addition, the device incorporates a vent that permits any heat generated by electronics or components to escape without adversely affecting the temperature sensor and passive infrared sensor. In addition, this permits any chimney effects generated by the hole in the wall to be measured by the device.
The device incorporates a temperature sensor transducers and sensing circuit that is mounted in the sensor device housing in a location that is exposed to the air in the room but not to air circulating internally within the device housing. A passive or active infrared sensor or ultrasonic sensor is also mounted within the device housing with or without an insulating layer of material or conformal coating located such that it is not adversely affected by the venting of heat generating components or the chimney effects generated by the mounting hole and the vent.
The device also comprises airflow vents on the top of the device housing to provide a venting means for any components that generate heat within the device. These vents also provide airflow from the mounting hole or the channel between the studs commonly found behind a wall within a building or wall. This flow of air provides for additional cooling of heat generating components in the device and ensures that the temperature and motion detection sensors are not adversely effected by this airflow.
Optionally, a sensor could be used to measure this air flow which could subsequently be used for building maintenance purposes, i.e., to notify the building owner of the location of air leaks within the walls of the building. Note that in most building, insulation is placed in the wall of a building to reduce the hot or cold air losses thus saving utility expenses. In this case, the device can be used to detect and measure the airflow that occurs in a wall and notify building personnel that a wall in which the device is mounted does not have adequate insulation and/or is not properly sealed. The vents could also be provided on any other surface of the device including opposite side surfaces or the bottom of the housing to provide additional or alternate venting.
The device also may include provisions for surface wiring and various types of mounting means. Included as well is an optional positive screw mounting. The mounting means could be directly on a wall, on a modular furniture channel or on or in a single gang wall box. The electrical connections can be made using flying leads or an RJ-11 or RJ-45 jack.
A lens is positioned in front of the infrared detector to focus infrared radiation and to prevent the ambient air from entering the device either from the temperature and humidity chamber or the heat vent. The lens may or may not include blinders.
Note that device may or may not have temperature sensing capability. Optionally, the front PC board containing the passive infrared transducer and the temperature sensor is installed using a layer of glue, foam or other gasket material to isolate the temperature sensor transducer and the infrared sensor from the back boards and the air channel created by the heat vent and the hole in the wall.
Optionally, two infrared sensing elements can be mounted on the same side of the printed circuit board. Partitioning of the two sensors can be performed arbitrarily as long as the passive infrared sensor is not exposed to erroneous air flows created by a natural or artificial air channel from the vents in the housing, the hole in the wall or the vents for the temperature chamber. Further, the motion sensing transducer is preferably not exposed to airflow or any other environmental conditions that could cause adverse behavior to the performance of the device. The temperature sensor is isolated with the absence of airflow over or around the infrared sensor. The housing is constructed such that it provides a chamber permitting the temperature to adjust naturally to the ambient air temperature to which it is exposed by the process of diffusion. This is accomplished by the use of the housing and a cover plate that is positioned over the temperature-sensing element. Foam or insulating material may optionally be used since the temperature element is not in a channel where air is circulating, but rather is in an alcove chamber that acclimates to the environment.
In another optional embodiment, the passive or active infrared and temperature sensors are on opposite sides of the printed circuit board or on different boards such that the air around the temperature sensor and the passive or active infrared sensor are isolated from one another by the nature of their location.
The device may incorporate at least one vent on the face of the device to allow the ambient air outside to acclimate with that of the temperature chamber. Thus, the temperature sensor may be located centrally behind the vents or louvers or anywhere within the area. In addition, the sensitivity, range, response time and accuracy may be adjusted mechanically, via the use of different housing and vent shapes and materials and also by electronic means.
Further, the device may incorporate adjustable louvers or vents over the temperature sensor create a baffle or regulator to adjust how quickly or slowly the temperature transducer will adjust to the ambient air. Also, the sensitivity, range, response time and accuracy can be adjusted by adapting the layout, position and design of the vents or louvers. It is also within the scope of the invention that mechanical or electronic means may be provided that open or close shudders on the vents over the temperature sensor.
Optionally, the device may incorporate fixed vents over the temperature sensor which create a fixed baffle or regulator thus determining a fixed means for how quickly or slowly the temperature transducer will adjust to the ambient air. The sensitivity, range, response time and accuracy, however, can still be adjusted by using different materials, thickness and shapes and by locating the sensor in different locations and orientations.
In another optional embodiment the device does not incorporate any vents and the temperature sensor is attached to the cover. In this case, the outside ambient air will be measured by measuring the inside surface temperature of the cover or plate. Therefore, the temperature sensing transducer is not directly exposed to any outside air. Also, the sensitivity, range, response time and accuracy may be adjusted using different materials, thickness and shapes and by locating the sensors in different locations or orientations.
In yet another optional embodiment of the invention the device does not incorporate vents and the temperature sensor is mounted on the surface of the device or in an alcove and exposed directly to the air. The outside ambient air is measured by measuring the air temperature of the outside air. Therefore, the temperature sensing transducer is directly exposed to the outside air. In addition, the sensitivity, range, response time and accuracy may be adjusted using different materials, thickness and shapes and by locating the sensors in different locations or orientations. Also, heat sinks can be added or connected to the sensor body and/or the leads and brought out of the device so as to improve the overall temperature response of the transducer and the device.
In still another optional embodiment of the invention the device does not incorporate vents and the temperature sensor comprises a cover on the device or a portion of the cover of the device and exposed directly to the air. The temperature-sensing element can also be either predominately outside, part of a cover or inside a cover of the device. This allows for very thin sensing materials to be used that are placed directly on the surface of the device, embedded in the layers of the cover of the device or predominately located on the inside portion of the cover of the device. The outside ambient air temperature is measured by measuring the air temperature of the outside air. Therefore, the temperature sensing transducer is directly exposed to the outside air.
In addition, the sensitivity, range, response time and accuracy may be adjusted using different materials, thickness and shapes and by locating the sensors in different locations or orientations. Although the temperature sensing element and housing can take on various forms, some of the types are enclosed. A software algorithm can be optionally employed which functions to correct the hysteresis by adjusting the actual temperature reading and hence approximating the theoretical response of a highly calibrated thermocouple. Additionally, the algorithm can employ programmed undershoots, overshoots, delays, amplitude shifts and a variety of other signal manipulations.
Additionally, since the temperature sensor may be exposed to the open air, a `fast change algorithm` can be employed which functions to recognize a rapid rate of change of temperature at the sensor, e.g., more than 15 degrees per 10 seconds. The rapid temperature change may either be due to someone placing their finger on the sensor, applying a heat gun, applying a cold compress or may be due to flames from a fire. The software routine, in response the detection of a rapid rate of change in temperature, can either send a warning message over the network or ignore the change in temperature, regarding it as an artificial heat/cold source. The device can be programmed to respond either way, i.e., sending temperature data over the network and having it acted upon or internally filtering it out and ignoring it.
In another embodiment the cover over the temperature sensor is removable. The cover can be adapted to either require or not require a tool for removal. Alternatively, the cover can be fixable attached to the device. In either embodiment, the temperature sensing transducer and/or other components of the temperature sensing circuit are in a socket which permits replacement with another transducer or component with different parameters. In addition, any local components such as potentiometers, switches, etc. requiring adjustment can be accessed, adjusted or changed.
In one embodiment of the invention the software may be adapted to adjust the sensitivity, response time, accuracy, range, etc. of the temperature sensor element and circuitry. In another embodiment, at least one air vent is provided which exposes both sides of the back PC board to the potential airflow generated when electrical components generate heat. In addition, the temperature chamber may be located in different parts of the device such as centrally or at the top or bottom.
The device may be mounted using a variety of means. These include various mounting plate variations including mounting in a single or multiple gang box, mounting on or in the hole of a module furniture channel, or being hung from underneath a fluorescent or incandescent fixture that is mounted on the desk, wall, floor or modular furniture and mounting on any other suitable surface. In addition, the device contains `mouse holes` which allow surface wiring to exit the device.
Another mounting option includes a hinged mounting bracket that permits the device to be mounted and electrically connected relatively easily. The mounting means uses either a positive locking screw or a snap fit. The positive locking screw option makes the device more tamperproof. The snap fit option provides a more aesthetically pleasing package.
The multi-sensor device of the present invention forms part of the network control system and generally comprises the following basic elements: (1) user interface, (2) power supply and media connections, (3) communications media and protocol and (4) one or more sensor inputs.
Additionally, functions can be performed which include some type of annunciation either by sound by using a buzzer or by sight by employing LEDs or controlling the lights in the room. For example, if the smoke detector transducer detects a fire, a buzzer could perform local annunciation. Alternatively, it could illuminate a visual indication, e.g., specially designed lights, LEDs, etc. for people that are hearing impaired. Also, a signal can be sent to a control unit or lamp actuator to flash one or more lights in the event that fire is detected for the benefit of the hearing impaired.
The power supply component for some of the devices in the system may include means to operate from 100 to 305 VAC. This type of device supplies an output voltage between 8 and 26 VDC. Alternatively, the device may omit a power supply that converts utility power but rather is adapted to receive power from another device that does incorporate a power supply that operates from 100 to 305 VAC. The means for distributing the electrical power to other devices could be accomplished via any suitable means including twisted pair cabling, electrical power line cables or any other power carrying media.
Another key feature of the system is a communications media and protocol that together form a communications network allowing messages to be communicated (1) between devices within the system and (2) between devices located within the system and devices located external to the system. The messages comprise, among other things, commands for controlling and/or monitoring signals. These messages could be tightly coupled, loosely coupled or of a macro broadcast nature. In addition, they may be one way, bidirectional, with established priorities or without. The network communications medium may comprise, for example, twisted pair Category 5 cabling, coaxial cabling, a standard POTS line, power line carrier, optical fiber, RF or infrared. The medium may be common or it may be shared with the possibility of requiring the use of gateways, routing devices or any other appropriate network device for carrying data signals.
Depending on the type of network medium in use in the system, the devices within the system include, within their housings, a slot that allows for the connection of a bus terminator. The bus terminator is typically an RC network that is connected to the device and serves to mechanically as well as electrically connect the device to the network communication line, e.g., twisted pair, coaxial, optical fiber, etc.
Thus, the system is able communicate to devices within the system to provide intrasystem control and monitoring as well as to communicate outside the system to provide intersystem control and monitoring. Data and/or commands are received and transmitted, real time relative readings can be received and transmitted, devices can be calibrated externally in an automatic self adjusting way or via a communication link over the network.
There is provided in accordance with the present invention a multiple sensor device for use on a local operating network comprising a housing, a communications transceiver for transmitting and receiving data between the multiple sensor device and the local operating network, a motion sensor, an ambient light sensor, a temperature sensor, a cavity within the housing adapted to contain a temperature sensor element such that the temperature sensor element is coupled to the surrounding environment but is neither exposed to the flow of air in the surrounding area nor lies in an airflow channel within the multiple sensor device, the temperature of the air within the cavity changing via diffusion with the air in the surrounding environment, lighting control means for determining the level of electrical power to be applied to a logical lighting load bound to the multiple sensor device, memory means for storing software application code and a controller adapted to execute one or more software applications stored in the memory means, the controller, in combination with the one or more software applications, operative to receive information over the local operating network from one or more electrical devices and to transmit information over the local operating network to one or more electrical devices.
The motion sensor comprises motion sensing circuitry including a passive infrared (PIR) sensor. The ambient light sensor comprises ambient light sensing circuitry including a photodiode. The temperature sensor comprises temperature sensing circuitry including the temperature sensor element. The multiple sensor device further comprises a pedestal within the housing wherein the temperature sensor element is positioned at a distance from a printed circuit board, the pedestal adapted to substantially environmentally seal the cavity from an inner portion of the housing.
The one or more motion detector elements and the temperature sensor element are located on opposite sides of a printed circuit board such that the air around the temperature sensor element and the one or more motion detector elements are isolated from one another by the nature of their location. The one or more motion detector elements and the temperature sensor element are located on different printed circuit boards such that the air around the temperature sensor element and the one or more motion detector elements are isolated from one another by the nature of their location. The housing comprises openings on one side only so as to direct airflow through an area that does not impact any circuitry located therewithin.
The multiple sensor device further comprises relay software application code for controlling the power on/off state of one or more logical lighting loads bound to the multiple sensor device; dimming software application code for providing dimming and brightening control of one or more dimming loads bound to the multiple sensor device; occupancy software application code for controlling a logical lighting load bound to the multiple sensor device in accordance with the detection of motion in an area; California Title 24 software application code for modifying relay and dimming functionality in accordance therewith; ambient light level software application code for maintaining a particular light level within an area; reset software application code for placing the multiple sensor device in an initialization state; go unconfigured software application code for placing the multiple sensor device in an unconfigured state; communication input/output (I/O) software application code for receiving data from and/or transmitting data to the local operating network; and inhibit software application code for inhibiting and overriding the normal operating mode of the multiple sensor device; temperature software application code for measuring the temperature of the area surrounding the multiple sensor device; and fast change application code for detecting rapid increases in temperature and in response thereto sending a warning message over the local operating network.
The local operating network may include twisted pair wiring, radio frequency (RF) communications, infrared communications, optical communication over optical fiber, power line carrier communications, coaxial communications, utilizes standard protocols such as LonWorks, CEBus, X10, BACNet and CAN.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1 is a front view illustration of a first embodiment of the sensor unit of the present invention incorporating a single switch and having the mid section cover in place;
FIG. 2 is a perspective view illustration of the sensor unit of the present invention incorporating a single switch and having the mid section cover in place;
FIG. 3 is a front view illustration of the sensor unit of the present invention with the mid section cover removed;
FIG. 4A is a perspective view illustration of the sensor unit of the present invention with the mid section cover removed;
FIG. 4B is a perspective view of the inside portion of the mid section cover;
FIG. 5A is a perspective view of an alternative mid section cover;
FIG. 5B is a perspective view of the inside portion of the alternative mid section cover;
FIG. 6A is a perspective view illustrating the mid section portion of the sensor unit in more detail wherein the PIR sensor blinds are in the open position;
FIG. 6B is a cross sectional view illustrating the mid section portion of the sensor unit in more detail wherein the PIR sensor blinds are in the open position;
FIG. 7A is a perspective view illustrating the mid section portion of the sensor unit in more detail wherein the PIR sensor blinds are in the closed position;
FIG. 7B is a cross sectional view illustrating the mid section portion of the sensor unit in more detail wherein the PIR sensor blinds are in the closed position;
FIG. 8 is a perspective view illustrating the temperature sensor and associated pedestal, housing and cover in more detail;
FIG. 9A is a perspective view illustrating the temperature sensor pedestal in more detail;
FIG. 9B is a side cross section view of the temperature sensor pedestal;
FIG. 10 is a front view illustration of a second embodiment of the sensor unit of the present invention incorporating two switches and having the mid section cover in place;
FIG. 11 is a front view illustration of a third embodiment of the sensor unit of the present invention incorporating two switches and having the mid section cover in place;
FIG. 12 is a perspective view illustration of a fourth embodiment of the sensor unit of the present invention, a surface mount sensor unit incorporating a single switch and having the mid section cover in place;
FIG. 13 is a diagram illustrating an example multi-sensor unit incorporating a display, dimming brighten/dim control and temperate/room brightness display;
FIG. 14 is a schematic diagram illustrating the occupancy, ambient light, switch, dimmer and temperature unit of the present invention;
FIG. 15 is a schematic diagram illustrating the motion sensor circuitry portion of the multi-sensor unit in more detail;
FIG. 16 is a schematic diagram illustrating the ambient light sensor circuitry portion of the multi-sensor unit in more detail;
FIG. 17 is a schematic diagram illustrating the temperature sensor circuitry portion of the multi-sensor unit in more detail;
FIG. 18 is a block diagram illustrating the communications transceiver portion of the control unit in more detail;
FIG. 19 is a block diagram illustrating the software portion of the multi-sensor unit in more detail;
FIG. 20 is a diagram illustrating the relationship between the actual and measured lux versus light intensity;
FIG. 21 is a flow diagram illustrating the read temperature sensor portion of the software in more detail; and
FIGS. 22A and 22B are a flow diagram illustrating the process temperature value portion of the software in more detail.
DETAILED DESCRIPTION OF THE INVENTION
Notation Used Throughout
The following notation is used throughout this document.
______________________________________Term Definition______________________________________AC Alternating CurrentBACNet Building Automation and Control Network (a data communication protocol)CAN Controller Area NetworkCEBus Consumer Electronics BusCO Carbon MonoxideEEPROM Electrically Erasable Programmable Read Only MemoryEIA Electronic Industries AssociationHVAC Heating Ventilation Air ConditioningIR InfraredLED Light Emitting DiodePC Printed CircuitPIR Passive InfraredPOTS Plain Old Telephone ServicePRTD Platinum Resistance Temperature DetectorPWM Pulse Width ModulationRAM Random Access MemoryRC Resister/CapacitorRF Radio FrequencyROM Read Only MemoryRTD Resistance Temperature DetectorSNVT Standard Network Variable Type______________________________________
General Description
The present invention comprises a multifunction sensor device incorporating a motion detection sensor, temperature sensor and ambient light sensor. The temperature sensor is exposed to the flow of air or the circulation of air via a vent that allows for air to circulate over the temperature sensor. A key characteristic of the present invention is that the passive infrared device used for motion detection is isolated from the air circulating for the purpose of temperature measurement by the use of a lens and an isolation chamber surrounding the temperature sensor.
The temperature and motion detection sensors may reside on the same or opposite sides of a PC board. If they reside on the same side a partition isolates the two transducers since the temperature sensor is required to have airflow while the passive infrared sensor should not.
The present invention provides an advantage in that it does not require the temperature sensor to be in an air channel or exposed to airflow, i.e., there is no separate entrance and exit of air having an associated speed, direction and force. The present invention does not utilize an airflow channel as used in prior art devices. Rather the device employs the concept of temperature diffusion with natural hysteresis by being exposed to the ambient air and changing in a deliberately slower and lagging manner. This necessitates that no air channel or flow exists from one end of the device to the other.
This device does not require the channeled circulation or flow of air over the temperature sensor that can be analogized to the water flow in an aqueduct that flows in a directional manner with varying directions, speeds and volumes. The present invention, on the other hand, measures temperature in a tidal fashion similar to the way the water in an ocean or harbor moves in and out from the shore. In other words, in one case air is flowing in a channel from one point to another similar to the way water flows in an aqueduct. In the case of the present invention, the air moves in and out of the same opening like that of the rise and fall of the water in the ocean wherein the point of entry and exit for the air is the same.
The phenomenon can also be described as the process of diffusion involving the intermingling of air molecules from outside the device and that of the air around the temperature sensor. Therefore, the temperature sensor and the passive infrared sensor could reside on the same or opposite sides of the PC board. The temperature and passive infrared elements, however, are required to be isolated from any erroneous air flow channels that may be present which could affect the accuracy of the measurements. Thus, the present invention provides a practical solution allowing temperature sensing and PIR motion sensing to reside in the same housing in a device that can be mounted in a single gang box.
A front view illustration of a first embodiment of the sensor unit of the present invention incorporating a single switch and having the mid section cover in place is shown in FIG. 1. The device, generally referenced 10, comprises a housing 14 connected to a mounting plate 12 via one or more fasteners through apertures 35. The housing 14 comprises an aperture covered by a lens or window 16. The aperture is used to house an occupancy sensor, e.g., passive infrared sensor (PIR). Note that the occupancy sensor may comprise one or more PIR detectors, e.g., dual PIR detectors.
A cover 18, which may or may not be removable, is positioned below the motion detection element lens 16. Making the cover 18 removable permits access to adjusting levers or blinds within the device that can be used to adjust the field of view of the PIR detectors in the device. The cover 18 also incorporates an aperture or vent 22 allowing air to diffuse through to an inner chamber housing the temperature sensor 48.
A switch cover or plate 28 having a raised bar portion 32 is located below the cover 18. The switch is used to control a logical load that the device is bound to. The logical load comprises one or more physical electrical loads. When pressed, a message is sent to the control device connected to the load to be switched. The message is interpreted and the control device carries out any required action.
An aperture 26 is located within the switch cover 28 and may optionally include a transparent or translucent window or light pipe therewithin. The aperture 26 provides visual access to a visual indicator such as an LED. The visual indicator is used to provide feedback to the user, e.g., in connection with the status of the bound logical electrical load or the status of occupancy as determined by the PIR sensor.
The device 10 also comprises a switch 30 that provides the user a means for placing the device into one or more modes. Typically, the switch 30 comprises three positions: ON, AUTO and OFF. The ON position turns the logical load on regardless of other inputs, the AUTO position lets the load be controlled by one or more sensor inputs and the OFF position turns the load off regardless of the state of the sensor inputs.
Apertures 33 at the top and bottom of the mounting plate 12 provide a means by which the device may be installed in a single or multiple gang wallbox. Apertures are also included to permit a cover plate (not shown) to be mounted over the device after it is installed in a wallbox.
When the device 10 is installed, for example in a wall, the hole in the wall required for the passage of wiring can either blow or suck air due to the chimney effect. The housing comprises openings in specific places, e.g., only on the top, so as to direct any potential airflow through an area that will not impact the operation of the electronic circuitry. If openings are placed on the top and bottom or not provided at all, this causes air to find its way in or out of the device through incidental openings in the face. This would cause air to flow over the electronic circuitry thus giving false readings, positive or negative.
A perspective view illustration of the sensor unit of the present invention incorporating a single switch and having the mid section cover in place is shown in FIG. 2. A large portion of the housing 14 is shown including the fasteners 35 for connecting the mounting plate 12 onto the housing 14. Shown are the occupancy sensor lens 16, cover 18 permitting access to the adjustable blinders within and vent or aperture 22 for permitting the diffusion of air to the temperature sensor, switch cover 28 including raised bar 32 and light pipe 26 and apertures 35 for affixing the device in single or multiple gang wallbox. Note that in this view, the on/auto/off switch 30 is not visible.
A front view illustration of the sensor unit of the present invention with the mid section cover removed is shown in FIG. 3. The device is shown with a removable cover 18 that has been removed from the housing 14. Visible now are the housing panel 50, service LED 40, service pin (momentary contact switch) 42, temperature sensor 48 and left and right adjusting levers 44, 46, respectively. Also shown are the mounting plate 12, mounting holes 33, PIR detector lens 16, switch cover 28, light pipe 26, switch bar 32, fasteners 35 and mode switch 30.
The blinders themselves are located behind the housing panel 50. The adjusting levers 44, 46, however, extend beyond the surface of the housing panel 50 so as to be accessible to a user. The blinders can be adjusted by moving the adjusting levers left or right along a linear path in the housing panel 50.
A perspective view illustration of the sensor unit of the present invention with the mid section cover removed is shown in FIG. 4A. The removable cover 18 is shown oriented in a removed position from the device 10. The cover comprises vents 22 that are positioned directly over the temperature sensor 48 when the cover 18 is in place in the housing 14. Tabs 23 on either side of the cover 18 secure it to the housing 14.
A perspective view of the inside portion of the mid section cover is shown in FIG. 4B. The cover is constructed to wrap around and enclose the entire width of the housing 14. A cylindrically shaped raised portion 52 extends outward from the inner surface of the cover 18. Located within this cylinder is the vent 22 with openings to permits the temperature sensor to contact the surrounding air. The height of the cylindrical portion 52 is adapted so that the outer surface mates flush with the surface of the housing panel 50 sealing off the temperature sensor from the inner space between the cover 18 and the surface of the housing panel 50.
The vent 22 is shown with openings that are in a horizontal fashion, however, they may be positioned horizontally, vertically or at any angle. Note, however, that the angle of the vent openings could affect the response of the temperature-sensing element by allowing either a more rapid rate of change or a slower rate of change based upon the size, quantity, angle and shape of the openings. This change in the architecture of the vent 22 can be compensated for in the hardware and/or software of the device. The optimum design for maximum performance depends on the given application and desired temperature change per time period.
A perspective view of an alternative mid section cover is shown in FIG. 5A. The alternative cover 420 comprises vent openings 422 that are raised so as to permit the temperature sensor below the cover to be exposed to air on two sides rather than just one. The cover 420 also comprises tabs 424 that function to secure it to the housing panel.
A perspective view of the inside portion of the alternative mid section cover 420 is shown in FIG. 5B. This inside view of the cover 420 shows the tabs 424, vent openings 422 and a raised rib portion 426 used to both to provide rigidity to the cover and to seal off the temperature sensor from the inner space between the cover 18 and the surface of the housing panel 50.
A perspective view illustrating the mid section portion of the sensor unit in more detail wherein the PIR detector blinds are in the open position is shown in FIG. 6A. The adjusting levers 44, 46 are shown in their widest open position, i.e., the adjusting levers are positioned closest to the housing panel 50. In this position, the PIR detectors are exposed to the largest area through the lens 16. An illustration of the cross sectional cut 51 is shown in FIG. 6B. The dual PIR detectors 60, 62 are fastened to a mounting block 63, which in turn is fixed to the printed circuit board 61. The lens 16 is fixed to the housing 14. The housing 14 is fastened to the mounting plate 12.
A partition or separating wall 76 functions to separate the radiation falling on the two detectors 60, 62, reducing interference effects as well as providing mechanical support in the event a foreign object is pressed against the lens. Two blinders 45, 47 functions to adjust the amount of radiation falling on the detectors 60, 62. Blinder 45 comprises an elongated shutter section 74 supported by a lower wall 66 and an upper wall (not shown) and a cylindrical stud or pivot 70. Similarly, blinder 47 comprises an elongated shutter section 72 supported by a lower wall 64 and an upper wall (not shown) and a cylindrical stud 68. The shutters are pivotally mounted to permit the blinders to be opened and closed. The blinders pivot on an axis perpendicular to the cylindrical studs 68, 70.
The blinders may be curved and are preferably constructed of a material that does not pass the signal the detectors are adapted to respond to. The shutter sections may comprise a natural or synthetic rubber, thermoset or thermoplastic material or any other suitable molded or machinable material. The material used is preferably moldable plastic.
A perspective view illustrating the mid section portion of the sensor unit in more detail wherein the PIR sensor blinds are in the closed position is shown in FIG. 7A. The adjusting levers 44, 46 are shown in their narrowest closed position, i.e., the adjusting levers are positioned furthest away from the housing panel 50. In this position, the PIR detectors are exposed to the smallest area through the lens 16. An illustration the cross sectional cut 53 is shown in FIG. 7B. The blinders 45, 47 are shown in their most closed position. In this position, the largest amount of radiation coming through the lens 16 is blocked from falling on the detectors 60, 62.
Note that each of the blinders 45, 47 is independently adjustable so that the angles that each blinder is set to may be equal or unequal. To narrow the field of view of the detectors, the blinders 45, 47 are rotated towards the partition 76. Vice versa, to broaden the field of view of the detectors, the blinders 45, 47 are rotated away from the partition 76. A more detailed description of the operation and construction of the blinders and the housing may be found in U.S. Pat. No. 5,739,753, entitled Detector System With Adjustable Field Of View, similarly assigned and incorporated herein by reference.
The mounting of the temperature sensor within the housing will now be described in more detail. A perspective view illustrating the temperature sensor and associated pedestal, housing and cover in more detail is shown in FIG. 8. For clarity sake, a cutaway drawing is shown wherein the remaining portion of the device has been omitted. The plurality of electrical leads 90 from the temperature sensor 48 are mounted on the PC board 80 via soldering or other means. The temperature sensor is mounted on a cylindrically shaped pedestal 82 that extends from the surface of the PC board 80 to the base of the temperature sensor 48. The electrical leads 90 of the temperature sensor 48 are inserted into corresponding openings on the upper surface of the pedestal 82. The circular cutout in the housing panel 50 is larger than the diameter of the temperature sensor 48 and adapted to mate with the surface of the cylindrical portion 92 of the cover 18. The inner diameter of the cylindrical portion 92 is made large enough so as to permit air to enter via the vent 22 and diffuse and circulate around the sensor.
In accordance with the present invention, the cover 18, housing panel 50 and pedestal 82 are constructed and positioned so as to seal off the temperature sensor from the rest of the device. Thus, an air chamber is formed in which the sensor is positioned which permits air from outside the device to diffuse through the vent 22 to the temperature sensor 48. Thus, the sensor is not exposed to any internal air channels that may be present and is separated from the PIR detectors so that they do not interfere with one another.
The pedestal 82 will now be described in more detail. A perspective view illustrating the temperature sensor pedestal 82 in more detail is shown in FIG. 9A. A side cross section view of the temperature sensor pedestal 82 is shown in FIG. 9B. As described above, the pedestal 82 functions to support the temperature sensor 48 at a height above the PC board and also functions to environmentally isolate the temperature sensor 48 from the interior of the device.
The pedestal 82 comprises a cylindrical body 100 and has a hollow interior. One end of the body 100 is closed off thus forming an upper portion. The upper portion comprises a substantially flat surface 94 with a plurality of apertures 96 therewithin. The flat surface 94 is recessed and adapted to mate with the bottom surface of the temperature sensor and is shaped in accordance therewith. Surrounding the flat portion is a circular raised ridge 98 extending around the entire diameter of the pedestal. A circular lip 93 is formed between the ridge 98 and the outer wall of the body 100.
The pedestal is positioned such that the lip 93 sits flush against the interior edge of the housing panel 50 (see FIG. 8). The ridge 98 is adapted to fit snug within the inner diameter of the cutout in the housing panel. Thus, the pedestal 82 functions to seal the temperature sensor 48 from air circulating within the device between the PC board 80 and the housing panel 50. It is important to note that other shapes for the pedestal 82 are also possible other than the one shown here. Regardless of the type or shape of the sensor, the upper surface portion of the pedestal should be adapted to mate with the sensor to enclose it thus substantially forming a seal around the bottom portion of the sensor as shown herein.
A second embodiment of the multi-sensor device will now be presented. The first embodiment discussed above, incorporated multiple sensors with a single switch. The second embodiment presented herein incorporates two switches. A front view illustration of a second embodiment of the sensor unit of the present invention incorporating two switches and having the mid section cover in place is shown in FIG. 10. The device, generally referenced 110, in similar to device 10 of FIG. 1 with the difference being that two switches are included rather than one. This embodiment is useful when it is desired to control two separate logical loads from a single device in on/off fashion.
The device comprises a mounting plate 112, housing 114, lens 116 for the PIR detectors, a cover 118 that may or may not be removable and which includes a vent 117 permitting air to diffuse through to the temperature sensor 48. A first switch cover 122 and a second switch cover 124 are provided having optional raised bumps 127 to help users distinguish the two switches from each other, such as when operating the switch in low light or darkness. Also shown are the mode switch 120 which can be placed in an on, auto or off positions and the light pipe 126 which permits an internal LED or other light source to be visible to a user.
A third embodiment also splits the switch cover 28 (FIG. 1) into two separate covers as the device of FIG. 10. A front view illustration of a third embodiment of the sensor unit of the present invention incorporating two switches and having the mid section cover in place is shown in FIG. 11. The device of FIG. 11, however, provides a dimmer function for a single or multiple electrical loads. The switch cover 123, when pressed, functions to brighten the load as indicated by the up arrow 129 and conversely, when the switch cover 125 is pressed, the load is dimmed, as indicated by the down arrow 121.
Similar to the device of FIG. 10, the device comprises a mounting plate 112, housing 114, lens 116 for the PIR detectors, a cover 118 that may or may not be removable and which includes a vent 117 permitting air to diffuse through to the temperature sensor 48. A mode switch 120 can be placed in an on, auto or off position and a light pipe 126 permits an internal LED or other light source to be visible to a user.
A fourth embodiment comprises a sensor unit similar to that of FIGS. 1 and 2 but suitable for mounting on a surface of a wall. A perspective view illustration of a fourth embodiment of the sensor unit of the present invention incorporating a single switch and having the mid section cover in place is shown in FIG. 12. The device, generally referenced 400, comprises a surface mount housing 402. The sensor unit also comprises an aperture covered by a lens or window 404. The aperture is used to house an occupancy sensor, e.g., passive infrared sensor (PIR). Note that the occupancy sensor may comprise one or more PIR detectors, e.g., dual PIR detectors.
A cover 406, which may or may not be removable, is positioned below the motion detection element lens 404. The cover 406 also incorporates an aperture or vent 408 allowing air to diffuse through to an inner chamber housing the temperature sensor 410.
A switch cover or plate 412 having a raised bar portion 414 is located below the cover 406. The switch is used to control a logical electrical load that the device is bound to. The logical load may comprise one or more physical electrical loads. When pressed, a message is sent to the control device connected to the load to be switched. The message is interpreted and the control device carries out any required action.
An aperture 416 is located within the switch cover 412 and may optionally include a transparent or translucent window or light pipe therewithin. The aperture 416 provides visual access to a visual indicator such as an LED. The visual indicator is used to provide feedback to the user, e.g., in connection with the status of the bound electrical load or the status of occupancy as determined by the PIR sensor.
The device 400 also comprises a switch 418 that provides the user a means for placing the device into one or more modes. Typically, the switch 418 comprises three positions: ON, AUTO and OFF: The ON position turns the electrical load on regardless of other inputs, the AUTO position lets the load be controlled by one or more sensor inputs and the OFF position turns the load off regardless of the state of the sensor inputs.
A diagram illustrating an example multi-sensor unit incorporating a display, dimming brighten/dim control and a temperate/room brightness display is shown in FIG. 13. This is one alternative for a display that may be incorporated into the multi-sensor device. The device, generally referenced 130, is shown installed with a cover plate in a single gang wallbox. The elements visible comprise a cover plate 140 that surrounds the device, an up/down dimming control 132, 134, a temperature display 138, a brightness display 136 and vents (or louvers) 135 for a temperature sensor located just below them. The vent 135 are similar in construction and function as vents 22 shown in FIGS. 1 and 2.
The temperature display 138 is shown in degrees Fahrenheit but can be also displayed in degrees Celsius. The dimming control 132, 134 can provide not only a brighten/dim function but also an on/off function as well. Note that the device 130 may function only as a control and display device or alternatively, may incorporate the temperature sensor, ambient light sensor and occupancy sensor of the first, second, third and fourth embodiments described hereinabove.
The present invention is intended to function within a local operating network or network based control system incorporating multiple devices having different functionality. As an example, the local operating network can be applied to lighting and HVAC systems. The local operating network comprises one or more devices, a user interface, actuator element, power supply, communications media, media connections and protocol and sensor inputs. These components function to work together with other devices that can communicate using the same standard communication protocol to form a local operating network. The system comprises various device functionality including but not limited to various sensor and transducer functions such as motion detector sensors, temperature sensors, humidity sensors and dimming sensors. The devices may be packaged in various form factors including but not limited to surface mount, flush mount, wall mount and single or dual gang wall box and ceiling mount. Other features include light harvesting or constant light maintenance, time of day scheduling, on/off/auto switching and sensing, single and multiple 20 A 100 to 305 VAC switching devices for incandescent and fluorescent lighting loads and 8 A 800 W 100 to 305 VAC dimming triac devices with a series air gap relay element. The devices comprise software and/or firmware for controlling the operation and features of the device, 15 VDC power supply for supplying electrical power, a reset push button for resetting the device and a communications network media interface.
To aid in understanding the principles of the present invention, the invention is described in the context of the LonWorks communication protocol developed by Echelon Corp. and which is now standard EIA 709.1 Control Network Protocol Specification, incorporated herein by reference. Other related specifications include EIA 709.2 Control Network Powerline Channel Specification and EIA 709.3 Free Topology Twisted Pair Channel Specification, both of which are incorporated wherein by reference.
The scope of the present invention, however, is not limited to the use of the LonWorks protocol. Other communication network protocols such as CEBus, etc. can be used to implement a control network within the scope of the present invention.
A key feature of the system is that the devices on the network can interoperate over the network. In addition, the system can be expanded at any time, and the functionality of the individual components can be changed at any time by downloading new firmware.
For a device to be interoperable it must communicate in accordance with the protocol specification in use in the system, e.g., LonWorks, CEBus, etc. If a device complies with the standard or protocol in use, it can communicate with other devices in the system. The temperature sensor within the device may be bound (as defined by the LonWorks protocol) to the HVAC system, for example. After a threshold temperature is exceeded, the temperature sensor can respond by sending a command to the HVAC system to turn on the air conditioning.
A schematic diagram illustrating the occupancy, ambient light, switch, dimmer and temperature unit (also referred to generally as the `unit`) of the present invention is shown in FIG. 14. The unit 150 comprises a controller 190 to which are connected various components. The controller 190 comprises a suitable processor such as a microprocessor or microcomputer. In the context of a LonWorks compatible network, the controller may comprise a Neuron 3120 or 3150 microcontroller manufactured by Motorola, Schaumberg, Ill. More detailed information on the Neuron chips can be found in the Motorola Databook: "LonWorks Technology Device Data," Rev. 3, 1997, incorporated herein by reference. Memory connected to the controller includes RAM 200, ROM 202 for firmware program storage and EEPROM 204 for storing downloadable software and various constants and parameters used by the unit.
A power supply 172 functions to supply the various voltages needed by the internal circuitry of the device, e.g., 5 V (Vcc), 15 V, etc. The power supply 172 may be adapted to provide V cc and other voltages required by the internal circuitry either directly from phase and neutral of the AC electrical power source or from an intermediate voltage generated by another power supply. For example, a 15 V supply voltage may be generated by another device and provided to the unit 150 via low voltage cabling. This reduces the complexity of the unit 150 thus reducing its cost by eliminating the requirement of having a high voltage power supply onboard.
A clock circuit 170 provides the clock signals required by the controller 190 and the remaining circuitry. The clock circuit may comprise one or more crystal oscillators for providing a stable reference clock signal. The reset/power supply monitor circuitry 168 provides a power up reset signal to the controller 190. The circuit also functions to monitor the output of the power supply. If the output voltage drops too low, the reset circuit 168 functions to generate a reset signal as operating at too low a voltage may yield unpredictable operation.
In the case of LonWorks compatible networks, the unit 150 comprises a service pin on the controller 190 to which is connected a momentary push button switch 156 and service indicator 154 which may comprise an LED. The switch 156 is connected between ground and the cathode of the LED 154. The anode of the LED is connected to Vcc via resister 152. A zener diode 158 clamps the voltage on the service pin to a predetermined level. The switch 156 is connected to the service pin via a series resistor 174. The service pin on the controller functions as both an input and an output. The controller 190 is adapted to detect the closure of the switch 156 and to perform service handling in response thereto. A more detailed description of the service pin and its associated internal processing can be found in the Motorola Databook referenced above.
The unit 150 is adapted to interoperate with other devices on the network. It incorporates communication means that comprises a communication transceiver 192 that interfaces the controller 190 to the network. The communications transceiver 192 may comprise any suitable communication/network interface means. The choice of network, e.g., LonWorks, CEBus, etc. in addition to the choice of media, determines the requirements for the communications transceiver 192. Using the LonWorks network as an example, the communications transceiver may comprise the FTT-10A twisted pair transceiver manufactured by Echelon Corp, Palo Alto, Calif. This transceiver comprises the necessary components to interface the controller to a twisted pair network. Transmit data from the controller 190 is input to the transceiver which functions to encode and process the data for placement onto the twisted pair cable. In addition, data received from the twisted pair wiring is processed and decoded and output to the controller 190. In addition to a free topology transceiver for a twisted pair network, other transceivers can be used such as RS-232, RS-485 or any other known physical layer interfaces suitable for use with the invention. In addition, transceivers for other types of media such as power line carrier and coaxial, for example, can also be used.
The unit 150 also comprises mode switch means that provides three modes of operation to the user: on/off/auto. The mode switch means comprises slide switch 160, pull up resisters 180, 182, series resisters 176, 178 and zener diodes 162, 164. The slide switch 160 is a three position slide switch which has two of the its terminals connected to two I/O pins on the controller 150 via series resistors 176, 178. One comprises the ON mode state and the other the OFF mode state. Software in the controller 150 periodically scans the two I/O pins for the state of the mode switch. The controller uses software adapted to decode the signal output of the mode switch to yield the actual switch position. The AUTO mode state is represented by both OFF and ON inputs being low.
The mode switch controls the operation of the unit 150. If the switch is in the OFF state, the on/off or brighten/dim features of the device are disabled. If the switch is in the AUTO position, the device operates normally. When the mode switch is on the ON position, the load is forced to turn on regardless of the state of the on/off/auto switch inputs.
As described hereinabove, the unit 150 is adapted to measure temperature, ambient light and to detect occupancy. The unit 150 comprises motion sensor circuitry 194 that functions to generate a MOTION signal representing the level of motion; ambient light sensor circuitry 196 that functions to generate a LUX signal representing the level of light; and temperature sensor circuitry 198 that functions to generate a TEMP signal representing the temperature level. The three analog signals MOTION, LUX and TEMP are input to a three channel A/D converter 188. Mux control of the A/D converter 188 is provided by the controller 190. The digitized output of the A/D converter is input to an I/O port on the controller 190. Alternatively, the A/D conversion function may be incorporated into the controller as is common with many commercially available microcontrollers.
An occupancy detect indicator 186, which may comprise an LED, provides a user visual feedback as to the detection of motion by the unit. The cathode of the LED 186 is input to an I/O pin on the controller 190 and the anode is pulled high by pull up resistor 184. An active low on the signal OCCUPANCY -- DETECT causes the LED to light.
The unit also provides a user the capability to either turn one or more lighting devices on/off and or to brighten/dim them. The unit 150 comprises circuitry two momentary contact switches 218, 220 that are connected to two I/O pins on the controller 190 via series resistors 206, 208, respectively. One end of each switch is coupled to ground and the other end is clamped by a zener diode 214, 216. The output of each switch is pulled high to V cc via pull up resistors 210, 212.
The two switches 218, 220 may be installed in the unit behind a rocker panel such that one switch is operated when one end of the toggle is pressed and the other switch is operated when the other end of the toggle is pressed. Pressing on the upper portion of the toggle turns the lighting load on and pressing on the lower potion turns it off. Alternatively, the unit can be adapted to cause the lighting load to brighten and dim in response to the toggle being pressed upwards or downwards, respectively.
In connection with the embodiment shown in FIG. 1, the device 10 only requires a single switch as this embodiment operates a single logical lighting load which could physically be many lighting loads. The switch plate 28 is adapted to operate only a single push button switch. Each switch closure toggles the state of the logical and physical lighting load.
In connection with the embodiment of FIG. 10, the device 110 requires two switches but each could operate a separate logical lighting load that could physically be many lighting loads. One switch plate 122 is associated with one load and the other switch plate 124 is associated with the other load. Each switch closure for each of the two switches functions to toggle the state of the respective logical and physical lighting load.
In connection with the embodiment of FIG. 11, the device 110 requires two switches for providing brighten/dim control for a single or multiple lighting load. One switch plate 123 is associated with the brighten function and the other switch plate 125 is associated with the dim function. In addition, the up switch plate 123 (seen in FIG. 11) may also turn the load on and the down switch plate 125 may function to turn the load off.
Thus, depending on the functionality desired in the device, the switches and associated hardware circuitry and software application may be adapted to provide numerous lighting control possibilities.
The motion sensor circuitry will now be described in more detail. A schematic diagram illustrating the motion sensor circuitry 194 portion of the multi-sensor unit 150 in more detail is shown in FIG. 15. The motion sensor circuitry 194 comprises one or more passive infrared (PIR) sensors coupled between ground and V cc . In the example disclosed herein, two PIR sensors 230, 232 are connected between ground and V cc . The PIR sensors may comprise a single sensor unit such as part number LHI878 manufactured by EG&G Heimann Optoelectronics GmbH, Wiesbaden, Germany, or in the alternative a dual sensor unit. The signal output of PIR sensor #1 230 is processed by circuitry comprising capacitor 234 and resistor 236. The signal is then input to a signal conditioning operation amplifier (op amp) circuit comprising op amp 242, capacitors 238, 244 and resistors 240, 245. The signal is input to the inverting or negative input of the op amp 242.
The signal output of PIR sensor #2 232 is processed by circuitry comprising capacitor 260 and resister 262. The signal is then input to the non-inverting or positive input of the op amp 242 via capacitors 264, 270 and resistors 266 and 268, 272 that form a voltage divider.
The output of the op amp 242 is input to a second signal conditioning op amp circuit comprising op amp 254, capacitors 246, 258, 252 and resistors 247, 256, 248 and 250. The output of the op amp 254, i.e., the MOTION signal, is input to the A/D converter 188 (FIG. 14). The digital representation of the level of motion is processed by the occupancy task (described in more detail below) to determine whether or not the occupancy state should be declared.
A schematic diagram illustrating the ambient light sensor circuitry portion of the multi-sensor unit in more detail is shown in FIG. 16. The ambient light sensor circuitry 196 comprises an ambient light detector 280 such as part number S1087 manufactured by Hamamatsu Photonics K.K., Hamamatsu City, Japan. The cathode of the light detector 280 is connected to the inverting or negative input of op amp 286. The anode of the detector 280 is connected to ground. A voltage reference V REF1 is input to the non-inverting or positive input of the op amp 286. Capacitor 284 and resistor 282 are placed in the feedback path from the output to the inverting input via a voltage divider connected to the output and consisting of resistors 287, 288. The output of the op amp 286, i.e., the LUX signal, is input to one of the channels of the A/D converter 188. The digitized ambient light level is processed by the ambient light level task (described in more detail below) and transmitted as a network variable to all devices over the network that are bound to the device.
A schematic diagram illustrating the temperature sensor circuitry portion of the multi-sensor unit in more detail is shown in FIG. 17. The temperature sensor circuitry 198 comprises a temperature sensor 290 such as the LM335A manufactured by National Semiconductor. The anode of the temperature sensor 290 is coupled to ground while the cathode is part of a voltage divider whereby an cathode voltage of 2.94 V (typically) represents a sensor case temperature of 25 degrees C. The voltage divider is formed between a 5 VDC power supply voltage connected to resistor 291. The cathode of the temperature sensor 290 is input to the non-inverting or positive input of op amp 298 via series resistor 292 and resistor 294 coupled to ground. The inverting or negative input of op amp 298 is connected to a voltage reference V REF2 (typically 2.5 VDC) via resistor 296 and is connected to the output via feedback resistor 300.
Resistors 296 and 300 are selected so as to provide a typical gain of 5, although other values of gain are also suitable. The gain of the op amp 298 can be modified to increase the resolution of the temperature reading over a given range. The output of the op amp 298, i.e., the TEMP signal, is input to one of the channels of the A/D converter 188. The digitized ambient light level is processed by the temperature task (described in more detail below) and transmitted as a network variable to all devices over the network that are bound to the device.
A block diagram illustrating the communications transceiver 192 portion of the control unit in more detail is shown in FIG. 18. As described previously, the communications transceiver 192 functions to enable the control unit to communicate with other devices over the network. It is desirable that each device in the network incorporate communications means enabling it to share information with other devices. This is not, however, an absolute necessity as devices that do not employ a communications protocol or employ a protocol that is proprietary can also be part of the network. For example, a direct connection to the lighting load via a 0-10 VDC control line as well as a single analog output signal may be employed to communicate to one or more lighting and HVAC loads. In this example, the communications transceiver 192 is adapted to transmit and receive data over twisted pair wiring. As mentioned previously, the communication transceiver 192 could be adapted to other type of media as well including, but not limited to, power line carrier, coaxial, RF, etc.
The communications transceiver 192 comprises a twisted pair transceiver 222 for receiving Tx data from the controller 190 and for outputting Rx data to the controller 190. In the transmit path, the twisted pair transceiver 222 processes the Tx data received from the controller 190 resulting in a signal suitable for placement onto the twisted pair network. The Tx output of the twisted pair transceiver 222, which has been converted to a differential 2-wire signal, is input to the twisted pair interface circuitry 224 which functions to adapt the differential transmit signal to the 2-wire twisted pair network 226.
In the receive path, the signal received over the 2-wire twisted pair network 226 is input to the twisted pair interface circuitry 224. The interface circuitry functions to output a 2-wire differential receive signal that is input to the twisted pair transceiver 222. The twisted pair transceiver 222 processes the differential receive signal and generates an output Rx signal suitable for input to the controller 190.
A more detailed description of the communications transceiver suitable for twisted pair networks and for other types of network media can be found in the Motorola Databook referenced above.
A block diagram illustrating the software portion of the multi-sensor unit in more detail is shown in FIG. 19. The hardware and software components of the unit in combination implement the functionality of the device. The software portion of the unit will now be described in more detail. Note that the implementation of the software may be different depending on the type of controller used to construct the unit. The functional tasks presented herein, however, can be implemented regardless of the actual implementation of the controller and/or software methodology used.
In the example presented herein, the controller is a Neuron 3120, 3150 or equivalent. Some of the functionality required to implement the control unit is incorporated into the device by the manufacturer. For example, the processing and associated firmware for implementing the physical, link and network layers of the communication stack are performed by means built into the Neuron processor. Thus, non-Neuron implementations of the control unit would require similar communication means to be able to share information with other devices over the network.
It is important to note that some of the tasks described herein may be event driven rather than operative in a sequential program fashion. The scope of the invention is not limited to any one particular implementation but is intended to encompass any realization of the functionality presented herein. In addition, some of the tasks are intended to function based on input received from other devices that also communicate over the network.
The various tasks described herein together implement the functionality of the unit. Each of the tasks will now be described in more detail. The main control task 310 coordinates the operation of the unit. The control task is responsible for the overall functioning of the unit including initialization, housekeeping tasks, polling tasks, sensor measurement, etc. In general, the unit is adapted to measure one or more physical quantities, transmit the measured quantities over the network, issue commands to a control unit located on the network and respond to commands received over the network from other sensors and control devices.
The control is effected by the use of network variables referred to as Standard Network Variable Types (SNVTs), in the case of LonWorks networks, for example. Thus, the data transmitted over the network is transmitted in the form of one or more network variables. In addition, based on the values of the various network variables received by the unit, the unit responds and behaves accordingly. The following describes the functionality provided by the unit.
Reset
The reset task 312 functions to place the controller into an initialization state. Variables are initialized, states of the various drivers are initialized, memory is cleared and the device begins executing its application code. The reset task executes at start up and at any other time it is called or the power is reset. The reset task functions to initialize the internal stack, service pin, internal state machines, external RAM, communication ports, timers and the scheduler. Before the application code begins executing, the oscillators are given a chance to stabilize.
Inhibit
The inhibit task 314 provides the capability of inhibiting and overriding the normal operating mode of the device and possibly one or more other devices connected to the network. This task is intended to operate within an electrical network that is made up of a plurality of devices wherein one or more of the devices is capable of commanding a control device to remove and reapply electrical power from a logical load connected to it. The devices or nodes communicate with the control device over the communications network.
For example, in a network utilizing a plurality of sensors and a control unit coupled to one or more logical loads, wherein each logical load comprises one or more physical electrical loads, one of the devices generates an inhibit signal that is communicated to the control unit. The control unit then propagates a feedback signal to the plurality of sensors. The sensor devices may comprise any type of sensor such as an occupancy sensor, switch or dimming sensor. Each sensor device is bound to its associated control unit. The one or more physical electrical loads are connected to the control unit. A feedback variable is bound from the control unit to each of the sensors.
When one of the sensors is turned off, i.e., its switch setting is placed in the OFF position, the inhibit task is operative to inhibit the normal operating mode of all the other input sensors and the control unit. Note that the term `turning a device off` includes switching the device off, disabling the device, placing the device in standby mode or tripping the device. There can be multiple sensor devices simultaneously in the off, disabled, standby or tripped mode. The control unit and its load remain inhibited until all the sensor devices are no longer in the off, disabled, standby or tripped mode. Thus, electrical power to the load controlled by the control unit remains disconnected until all sensor devices are in the on position.
This feature is particularly suited to permit maintenance or service to be performed in a safe manner on (1) any of the sensors, i.e., switching, occupancy, dimming, etc. sensor devices, logically connected to the same control unit or on (2) the load physically connected to the control unit.
The mode switch 160 (FIG. 14) is used for placing the unit into an off, disabled, standby, tripped or maintenance inhibit mode. The switch means can be implemented using mechanical or electronic means or a combination of the two either at the device itself or remotely over a network via one or more control commands. Optionally, a pull out tab or mechanical arm can be used to put the input device into the maintenance off mode when it is pulled out. The pull out tab or mechanical arm would leave the input device in normal operating mode when pushed back in.
In either case, when the input device is placed in the off position, an inhibit message is sent to the control unit over the network. In response, electrical power to the attached load is removed. Subsequently, all other sensor devices that are bound to the same control unit are inhibited from causing power to be applied to the load. This permits safe access to the control unit and to the load for service or maintenance reasons. The normal operating mode of all the sensor devices connected to the same control unit is inhibited or overridden. Until all sensor devices that have previously been placed in the off mode are put into the on mode and returned to their normal operating condition, all sensor devices are not permitted to change the state of the load or the control unit.
Further details on the implementation of the inhibit task can be found in co-pending U.S. application Ser. No. 09/045,625, filed Mar. 20, 1998 entitled APPARATUS FOR AND METHOD OF INHIBITING AND OVERRIDING AN ELECTRICAL CONTROL DEVICE, similarly assigned and incorporated herein by reference.
Go Unconfigured
The go unconfigured task 316 provides the capability of placing a device (also referred to as a node) in an unconfigured state. This is useful whenever the device needs to be placed in a certain state such as the unconfigured state. A major advantage of this feature is that it provides an installer of LonWorks based systems the ability to easily place the electrical device (the node) in an unconfigured state utilizing the same button 156 (FIG. 14) that is used in making a service request.
When the device is in the configured node state (also known as the normal operating mode state), the device is considered configured, the application is running and the configuration is considered valid. It is only in this state that both local and network derived messages destined for the application software layer are received. In the other states, i.e., the application-less and unconfigured states, these messages are discarded and the node status indicator 154 (FIG. 14) is off. The node status indicator is typically a service light emitting diode (LED) that is used to indicate to a user the status of the node.
A device is referred to as configured if it is either in the hard off-line mode (i.e., an application is loaded but not running) or in the configured node state as described above. A node is considered unconfigured if it is either application-less or in the unconfigured state, i.e., no valid configuration in either case. Via the go unconfigured task, a user can force the device into the unconfigured state so that it can be re-bound to the network, i.e., the device must be `reset` within the LonWorks system.
More specifically, the term going unconfigured, is defined as having the execution application program loaded but without the configuration available. The configuration may either be (1) not loaded (2) being re-loaded or (3) deemed bad due to a configuration checksum error.
In a LonWorks device, an executable application program can place its own node into the unconfigured state by calling the Neuron C built in function `go -- unconfigured()`. Using this built in function, an application program can determine, based on various parameters, whether or not an application should enter this state. When the device does enter the unconfigured state, the Node Status Indicator flashes at a rate of once per second.
The unit of the present invention utilizes the service pin on the controller, e.g., Neuron chip, to place the node in an unconfigured state. Under control of the firmware built into the Neuron chip, the service pin is used during the configuration, installation and maintenance of the node embodying the Neuron chip. The firmware flashes an LED suitably connected to the service pin at a rate of 1/2 Hz when the Neuron chip has not been configured with network address information. When the service pin is grounded, the Neuron chip transmits a network management message containing its 48 bit unique ID on the network. A network management device to install and configure the node can then utilize the information contained within the message. The Neuron chip checks the state of the service pin on a periodic basis by the network processor firmware within the chip. Normally, the service pin is active low.
Further details on the implementation of the go unconfigured task can be found in co-pending U.S. application Ser. No. 09/080,916, filed May 18, 1998 entitled APPARATUS FOR AND METHOD OF PLACING A NODE IN AN UNCONFIGURED STATE, similarly assigned and incorporated herein by reference.
Communication I/O
The communication I/O task 318 functions in conjunction with the communication means located in the controller and the communication transceiver connected to the controller. The controller itself comprises means for receiving and transmitting information over the network. As described previously, the communications firmware for enabling communications over the network is built into the Neuron chip. Further details can be found in the Motorola Databook referenced above.
Occupancy
The occupancy task 320 is used to detect occupancy and maintain the occupied state until no occupancy is detected. The occupancy task 320 implements the occupancy functionality of the unit. Typically, the output generated by the occupancy task 320 is bound to a control unit or similar device, which controls electrical power to the load. The occupancy task 320 performs the motion detection function and calculates application delay and/or hold times as required. The SNVT `SNVT -- occupancy` can be used in implementing the occupancy detection and reporting functions.
Along with the basic detection of motion, the occupancy task can utilize one or more configuration parameters that function to control the detection and reporting operations. In particular, a hold time parameter, e.g., SNVT -- time -- sec nciHoldTime, can be set which delays the reporting of a change from the occupied to unoccupied state. Note that preferably the occupancy sensor changes from the unoccupied state to the occupied state rapidly, but changes from the occupied to the unoccupied states after a delay. The purpose of the delay is to avoid unnecessary network traffic when the occupancy sensor is not detecting motion continuously. This is particularly useful when PIR detectors are employed in the sensor unit.
The occupancy task 320 functions to control a relay or dimming load in accordance with the detection of motion in an area. One or more occupancy sensor devices can be bound to a relay or dimming object within the controller. A network may include a plurality of occupancy sensors and a control unit coupled to a load. Typically, the occupancy sensors are bound via the network to the control unit. The load to be switched or dimmed is coupled to the control unit. In a LonWorks network, any number of sensors can be bound to the same object (load). The occupancy task 320 does utilize any feedback from the control unit. In addition, more than one load can be connected to and controlled by the control unit.
In addition, a light-harvesting feature (described in more detail below) can be enabled or disabled for each input. This feature utilizes the light level sensed by an ambient light level sensor also connected to the network. When occupancy is detected, the sensor functions to generate a command that is sent to the occupancy task in the control unit. The command is sent via the setting of a value for a particular network variable. The occupancy task first checks the current level of the light. If light harvesting is enabled, the lights turn on in accordance with the light-harvesting task. The ambient light level is periodically checked and the brightness of the lights is adjusted accordingly. If light harvesting is not enabled, then the lights are turned on in accordance with the following Lighting Priority Order:
1. If the last light level value was not equal to zero, i.e., completely off or 0%, then the level of the lights will be set to the last dim level that was set at the time the lights were last turned off.
2. If the last light level value was equal to zero but the Preferred Level is not equal to zero then the level of the lights will be set to the Preferred Level value. Note that it is not desirable to set the lights to a 0% dim level, as confusion may arise whether the device is operating properly, since 0% dim appears as completely off.
3. If the last light level value was equal to zero and the Preferred Level is null then the level of the lights is set to maximum brightness, i.e., 100%.
Note that in each case, the light level is brought up the required level in gradual increments, resulting in a gradual turn on of the lighting load. The Preferred Level value (also referred to as the Happy State) is a brightness level that is calculated in order to reduce the number of writes to the EEPROM connected to the controller. The Preferred Level is generated by using a sliding check of the brightness levels set by the user over time. The Preferred Level is set if the light is turned on to the same brightness level a predetermined number of times consecutively, e.g., 5 times. If the current level is equal to the previous level the required number of times consecutively, then that particular brightness level is stored in EEPROM and a variable is set within the controller. The counter is reset once a current level does not match the current level. Note that a Preferred Level of zero is stored or permitted.
As described above, the analog signal MOTION output by the occupancy sensor circuitry 194 (FIG. 15) is input to one of the channels of the A/D converter 188. The digitized value is then input to the controller who reads it periodically. The MOTION signal is a bipolar analog signal adapted to the range of 0 to 5 V for input to the A/D converter. With a 12-bit A/D converter, the MOTION signal is converted into a value from 0 to 4096. The value 2300 is taken as the null motion level that represents no detected motion.
The controller functions to generate a window with high sense and a low sense values forming the boundaries of thresholds of the window. If the A/D value exceeds the high sense threshold or is lower than the low sense threshold, occupancy is declared. The high and low sense values are variable depending on the field of view/sensitivity setting set by the user. The values of the high and low sense thresholds for various field of view settings are presented below in Table 1.
TABLE 1______________________________________Field Of View Low Sense High Sense Delta .increment.______________________________________High 1900 2700 ±350On 1700 2900 ±500Medium 1300 3300 ±1000Low 700 3900 ±2000Off Occupancy Off______________________________________
Thus, based on the field of view setting, occupancy is declared when the A/D value exceeds either the low or high sense thresholds. The larger the field of view, the smaller the window size, i.e., smaller A/D values cause occupancy to be declared. Conversely, the smaller the field of view, the larger the window size, i.e., larger A/D values cause occupancy to be declared.
After either the low or high sense threshold is exceeded, the AID value is tracked and the occupancy detect LED 186 (FIG. 14) is illuminated. Once the value falls back below either threshold, a delay timer is started. The length of the timer is adjustable and is relatively short, e.g., 50 to 100 ms. If the A/D value remains within the threshold settings for the entire timer duration, the occupancy LED is extinguished and a hold timer is started. The occupancy state is not changed at this point and electrical power to the load is not removed. The hold timer counts a hold time duration that is settable over the network by a user. Only after the hold time is reached without the A/D value exceeding either threshold is the occupancy state removed and a network message is transmitted instructing the control unit to turn the load off.
For LonWorks based networks, the following output network variables may be used in implementing the occupancy sensor function: occupancy, occupancy numerical output and occupancy auxiliary state. The following input network variables may be used: hold time, maximum send time and field of view.
A key feature of the unit is that both the field of view and the sensitivity of the occupancy sensor can be adjusted over the network. Optionally, adjustments can be scheduled at either specific or random time intervals as determined by a scheduler who transmits commands to the unit. For example, the field of view can be automatically adjusted over the network in accordance with the time of day, time clock, scheduler or other devices or inputs such as a local set point button/slider or via a network management tool.
The field of view and the sensitivity of the occupancy sensor can be changed by varying the threshold window that is used to process the MOTION signal (FIG. 15) output of the occupancy sensor circuitry. The threshold information may reside in non-volatile memory, e.g., EEPROM, and can be altered over the network. It may also be stored in RAM and changed dynamically over the network. Different applications could employ the ability to adjust the field of view combined with the ability to set different levels, different polarities such as negative or positive response of the PIR, time frames or number of hits or cycles.
A user of the unit has the ability to select the desired field of view level between high, on, medium, low and off, representing fields of view >100%, 100%, 50%, 25% and off, respectively.
The occupancy sensor can be overridden, i.e., ignored, in response to a scheduled or random input. For example, occupancy may be ignored during certain times of the day such as during nighttime hours. A switch can be bound with the occupancy sensor to provide an override function to turn the lights on at night or during off-hours. This feature is useful since the PIR detectors activate when they detect changes in heat or high levels of energy which are often generated, for example, by walkie talkies. Thus, this feature functions to minimize the `false ons` that occur when the HVAC system is turned off at night or on in the morning.
In addition, the unit may be adapted to require a sequence or combination of multiple sensor input activity from one or more devices in various locations before establishing that occupancy exists. This functions to reduce the effects of noise that may be present in the environment the unit is operative in.
Ambient Light Level
The ambient light task 322 functions to measure the ambient light level and output the corresponding lux value. The ambient light task 322 implements the ambient light functionality of the unit utilizing the LUX output of the ambient light sensor circuitry 196 (FIG. 16). The ambient light level task functions to maintain a particular lux level within an area, if the user enables this mode. The task receives ambient light sensor data from an ambient light sensor bound to it over the network. The ambient light sensor periodically sends lux reading updates to the ambient light level task. The lux level to be maintained is provided by the user.
The ambient light level task operates in conjunction with the occupancy sensor device and its related occupancy task. If an occupancy sensor detects motion, for example, the lights are controlled in accordance with the current ambient light level reading. If the light level is greater than or equal to the current maintenance lux level setting, then the lights are not turned on. If, on the other hand, the light level is greater than or equal to the current maintain lux level setting, then the light is turned on in accordance with the Lighting Priority Order described above.
The ambient light sensor has the ability to detect different light levels and is self calibrated via the intrinsic gain in each device. The sensors can be calibrated in the field by taking two ambient light readings and entering the values into a network management tool that would then adjust the processing algorithm to produce a more accurate reading.
One application of the ambient light feature is to maintain a particular lux level within an area. The ambient light task 322 receives light level data from the ambient light sensor and transmits the lux readings to all devices bound to it over the network.
The standard network variable SNVT -- lux can be employed in the implementation of the ambient light task 322. In addition to the basic lux light level output, the light sensor object may input one or more parameters. In particular, the parameters may include the following:
1. location (nciLocation)--physical location of the light sensor.
2. reflection factor (nciReflection)--used to adjust the internal gain factor for the measured illumination level; this may be necessary because the amount of light reflected back to the sensor element from the surface might be different.
3. field calibration (nciFieldCalibr)--used by the light sensor to self calibrate the sensor circuitry; the ambient light value measured with an external lux meter is used as input to the light sensor which then adjusts its reflection factor to yield the same output value.
4. Minimum send time (nciMinSendT)--used to control the minimum period between network variable transmissions, i.e., the maximum transmission rate.
5. Maximum send time (nciMaxSendT)--used to control the maximum period of time that expires before the current lux level is transmitted; this provides a heartbeat output that can be used by bound objects to ensure that the light sensor is still functioning properly.
6. Send on delta (nciMinDelta)--used to determine the amount by which the value obtained by the ambient light sensor circuitry must change before the lux level is transmitted.
Note that these parameters are optional and may or may not be used in any particular implementation of the ambient light task.
The ambient light sensor circuitry operates with an offset. A light level of zero lux generates approximately 1.6 V at the output of the A/D converter 188. In addition, the sensor and its housing are adapted to be sensitive to changes in light intensity on tabletops within the area to be covered. The cover (lens) positioned over the sensor so that light enters via the aperture 26 (FIG. 1) in the switch cover. This arrangement, however, functions to attenuate the light even more. Thus, an offset and a correction factor must be applied to values read from the sensor.
A value from the sensor is read in to the controller 190 periodically, e.g., every 100 ms. An average is computed for every 10 values read in. This number is then used to calculate a lux reading using the following expression, ##EQU1## The above equation yields a LUX value in the range of 0 to 2,500 lux. In addition, a user can supply a reflection coefficient that can be factored into the calculation of the lux value. The reflection coefficient is expressed as a number in the range of +/-3.0. The lux value calculated using the equation above is multiplied by the reflection coefficient to yield a lux value compensated for reflections.
Further, a linearity correction (slope offset correction adjustment or calibration factor) can be applied which typically varies from room to room. Two light readings are taken, one in bright light and the other in dim light. Two sets of readings are taken: one using the unit 150 and the other set using an external sensor. The system installer can perform this procedure at the time the system is initially installed.
A diagram illustrating the relationship between the actual and measured lux versus light intensity is shown in FIG. 20. The linearity correction procedure described above, compensates for this slope offset.
Temperature
The temperature task 324 functions to read the TEMP signals generated by the temperature sensor circuitry 198 (FIG. 17). The TEMP value is converted to digital by the A/D converter 188 and read into the controller 190. The temperature sensor circuitry is adapted to output a TEMP value corresponding to a temperature in the range of 0 to 50° C. Assuming an A/D with 0 to 5 V output range, a temperature of 25° C corresponds approximately to 2.5 V at the output of the A/D converter 188.
In accordance with the TEMP signal read in, a temperature value is calculated using the following, ##EQU2## The nonlinearity of the temperature sensor can be corrected for by applying a calibration correction using slope and offset adjustments in similar fashion as the occupancy task described above.
In addition, a standard network variable can be employed in the implementation of the temperature sensor task. In addition to the basic temperature output, the temperature sensor object may input one or more parameters. In particular, the parameters may include the following:
1. location (nciLocation)--physical location of the light sensor.
2. field calibration (nciFieldCalibr)--used by the temperature sensor to self calibrate the sensor circuitry; the temperature value measured with an external temperature sensor is used as input to the temperature sensor which then adjusts its algorithm to yield the same output value.
3. Minimum send time (nciMinSendT)--used to control the minimum period between network variable transmissions, i.e., the maximum transmission rate.
4. Maximum send time (nciMaxSendT)--used to control the maximum period of time that expires before the current temperature reading is transmitted; this provides a heartbeat output that can be used by bound objects to ensure that the temperature sensor is still functioning properly.
5. Send on delta (nciMinDelta)--used to determine the amount by which the value obtained by the temperature sensor circuitry must change before the temperature reading is transmitted.
Note that these parameters are optional and may or may not be used in any particular implementation of the temperature sensor task.
As described above, the temperature sensor and software include an offset calibration value that can be employed to calibrate the temperature sensor. Also, the speed at which the temperature value is sent over the network can be increased or decreased.
A flow diagram illustrating the portion of the software used to read the temperature sensor in more detail is shown in FIG. 21. This process is performed on a periodic basis, e.g., every 100 ms. An average temperature reading is calculated every 10 cycles, i.e., once a second, in order to reduce the effect of transients and random fluctuations. First, it is checked whether the OUTPUT -- TEMP flag is set (step 330). This flag is set true at the end of a cycle of 10 readings. If the flag is true, then the accumulated temperature variable TEMP -- VALUE is reset to zero (step 332), the counter TEMP -- COUNT is reset to zero (step 334) and the OUTPUT -- TEMP flag is cleared (step 336).
If the flag is not set, these steps are skipped and control passes to step 338 wherein a temperature reading is input from the A/D converter 188 (step 338). The value read in is added to TEMP -- VALUE (step 340). The counter TEMP -- COUNT is incremented (step 342). When the count reaches 10 (step 344), the TEMP -- SENSOR flag is set (step 346). If 10 temperature values have not yet been read in, the process ends. Note that depending on the controller used to implement the invention, the count may exceed 10 such as when the event scheduler internal to the controller could not service the event fast enough due to high loading.
A flow diagram illustrating the process temperature value portion of the software in more detail is shown in FIGS. 22A and 22B. This routine is performed whenever the TEMP -- SENSOR flag is set. First, the temperature readings are averaged by dividing TEMP -- VALUE by TEMP -- COUNT (step 350). The OUTPUT -- TEMP flag is set so that a new set of readings can be accumulated (step 352). The digital number obtained for the average is converted to an equivalent number in degrees Celsius (step 354). After converting the average to degrees Celsius, one or more slope, offset and corrective algorithm adjustments are then performed (step 356).
It is then checked whether a TEMP -- OFFSET update has been received over the network (step 358). If so, a new calibration offset temperature value is calculated (step 360). If no update has been received, the current temperature is calculated using the calibration offset (step 362).
If the current temperature is changing at a rate faster than a predetermined rate (step 363), then it is assumed that either a false influence is occurring or a fire may exist in the vicinity of the device. As described previously, since the temperature sensor may be exposed to the open air, a `fast change algorithm` can be employed which functions to recognize a rapid rate of change of temperature at the sensor, e.g., more than 15 degrees per 10 seconds. The rapid temperature change may either be due to someone placing their finger on the sensor, applying a heat gun, applying a cold compress or may be due to flames from a fire. The software routine, in response the detection of a rapid rate of change in temperature, can either send a warning message over the network or ignore the change in temperature, regarding it as an artificial heat/cold source. The device can be programmed to respond either way, i.e., sending temperature data over the network and having it acted upon or internally filtering it out and ignoring it.
If a message is sent, the actual temperature value may or may not be sent depending on the configuration setup of the device. For example, if it is a false influence, the rapid change in temperature should be ignored and not displayed on the network or a local display, e.g., LCD display. To determine whether the current temperature is changing too fast, the previous temperature is compared to the current temperature. If the difference is too large per a specific time interval, then the method continues with step 374. If not, the method continues with step 364.
Next, the temperature reading just calculated is compared with the previous reading. If the difference is greater than a threshold (step 364) then the current temperature is transmitted over the network (step 366). If the difference is less than or equal to the threshold, the temperature is transmitted over the network (step 370) if the TEMP -- TIMER timer expired (step 368). The timer is then reset (step 372).
The previous temperature is set equal to the current temperature (step 374) and the TEMP -- SENSOR flag is cleared (step 376).
Dimming
The dimming task 326 implements the dimming functionality of the unit and functions to control a dimming load connected to a control unit or other dimming device directly or via the network. The unit 150 is connected to the network and bound to one or more control units. Brighten and dim commands are generated by the dimming task 326 and transmitted onto the network. In response, the dimming task 326 in the corresponding control units brightens or dims its associated dimming load accordingly.
A network may utilize a plurality of dimming sensors and a control unit coupled to a logical dimming load. The plurality of dimming sensors is bound to the control unit via the network. The logical dimming load, represented by one or more physical dimming electrical loads, is connected to the control unit. Note that the control unit may be adapted to control any number of logical or physical dimming loads. In addition, a feedback signal is bound from the control unit to each of the units 150. It is also the intent of the invention to allow for the dimming element and software to be incorporated within the sensor device 110 as well. That is, the control unit described above was described as a separate device for illustration purposes only, i.e., as an illustration of how the loads can be dimmed, and does not necessarily have to be constructed as a separate device.
On each of the units 150, the brightness level is adjusted by pressing a switch 28 (FIG. 1), 122, 124 (FIG. 10), 123, 125 (FIG. 11). Pressing on the switch increases the brightness level by an incremental amount, e.g., 1/2 or 1 full unit of resolution if the feedback equals zero. When the switch is pressed, a command is sent from the unit to the control unit that it is bound to. To dim the light, the switch is pressed again which causes a command to be sent to the control unit instructing it to dim the load bound to it.
Note that on single switch units, the single switch performs either on/off control or brighten/dim control. On two-switch units, on/off and brighten/dim control are provided for each load. Unit 110 (FIG. 11) alternatively uses two switches 123, 125 (an up and a down) to control single dimming load.
If the light was previously off, i.e., feedback equals zero, then quickly tapping the switch will turn the lights on in accordance with the Lighting Priority Order described above. Once on, a quick tap on the switch will turn the lights off. Once on, if the switch is pressed and held, the brightness level increases until the maximum brightness level is reached at which point no further action occurs. As the light level ramps up, the user ceases holding the switch and the light level reached at that point is used. Maximum brightness can be achieved faster by quickly tapping twice on the switch. Similarly, pressing and holding the switch causes the light level to dim until the user ceases holding the switch. Continuously holding the switch causes the light to dim to the completely off level.
If more than one unit 150 sensor is bound to the same dimming load in the control unit, then feedback is used to communicate information from the control unit to each of the units bound to it. Feedback is utilized to inform the other units that are also controlling the dimming load as to the state of the dimming load. Thus, all the units are synchronized and via feedback from the control unit are able to effectively track the actions of each other. The control unit preferably sends the feedback information after each command is received. For example, feedback may be sent to all the bound unit 200 ms after the last command related to the light level is received.
Power On/Off/Auto Task
The power on/off task 328 functions to control the on and off control of a relay in the control unit that is bound to the unit. The task functions similarly to the dimming task, with the difference being that the load is turned off and on rather than dimmed and brightened. Similar to the case of dimming, the on/off control of a load also may include binding a feedback variable to all the dimmer/switch units bound to a particular load connected to the control unit.
Each relay in the control unit has an associated relay driver circuit and a relay load. Using network variables within the context of a LonWorks based network, the task may respond, i.e., be bound, to various network variables and/or other input. For example, the task may be suitably programmed to respond to settings of the ON/AUTO/OFF mode switch 160 (FIG. 14) on the unit. If the mode is set to on, then the relay is turned on regardless of the setting of a bound occupancy sensor device or other sensor device. Thus, if a user turns the switch to the ON position, the task functions to transmit a command to the control unit to turn the relay on (provided that the control unit is not in the inhibited state). The relay would stay on, regardless of the state of other bound sensor devices such as occupancy sensor devices. The task also responds to the on/off commands from the switch 28 (FIG. 1); 122, 124 (FIG. 10), turning the relay on and off accordingly. When in the AUTO state, the relay load is controlled by switch closures on the unit 150 via variables bound to it over the network.
California Title 24
The California Title 24 task 329 functions to modify the operation of the power on/off and dimming tasks. This task prevents the relay or dimming load from turning on when there is sufficient light. Thus, the occupancy sensor or switch input sensor bound to the relay or dimming load attached to the control unit will not be able to turn the respective load on. In addition, if a sensor has already turned the load on, a switch input can only turn them off but not back on.
In connection with the dimming task 326 described above, if there is sufficient light in the room, the lights will not turn on or brighten to a `turn on` or brighten command from a unit bound to the light.
In connection with the occupancy task 320, the lights will not turn on if there is sufficient light in the room. In the California Title 24 mode, the lights may only be turned on via the occupancy sensor circuitry detecting motion. A user may, however, dim the lights and turn them off via a switch. A user may brighten the lights but they will immediately dim in accordance with the light harvesting setting, if light harvesting is active. If light harvesting is not active, attempting to brighten and/or turn the lights on via a switch will have no effect.
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. | A multifunction sensor device which provides various transducer functions including means for performing temperature sensing, ambient light sensing, motion detection, switching functions and a means to put the device in an on, off or auto mode. The device has utility in environments such as that found in offices, schools, homes, industrial plants or any other type of automated facility in which sensors are utilized for energy monitoring and control, end user convenience or HVAC control. Key elements of the invention include overcoming the difficulty of mounting diverse sensors or transducers within the same device or housing; permitting these various sensors to exist in a single package that can be mounted to a wall in a substantially flush manner; and eliminating the requirement of an air flow channel in the device, thus minimizing any adverse effects on the motion detecting element or sensor as well as providing built in partial hysteresis. The device may include additional transducers or sensors and is constructed such that the temperature sensor is neither exposed to the flow of air in a room or area nor in an airflow channel whereby a chimney effect may occur. The device has a passive alcove or cavity that acclimates to the ambient air temperature through the process of diffusion. The device can transmit and receive real time data, relative data and actual discrete data in addition to switching and controlling loads locally or remotely. | 7 |
This application is a continuation-in-part application of application Ser. No. 07/961,222 filed Oct. 15, 1992 and now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a technique of improving the adhesion or binding properties of a diamond-like thin film with respect to slightly adhesive substrates of articles, such as metallic mold substrates of hardened steel.
"Diamond-like film" or "diamond-like thin film" used herein is defined as an amorphous carbon film having a Raman's absorption at about 1,550 cm -1 . It should be noted that the diamond-like film is clearly different from diamond film because the latter has a sharp Raman's absorption peak at 1,333 cm -1 and is an aggregate of micro crystals. Diamond-like film does not have Raman's absorption peak at 1,333 cm -1 and usually such diamond-like film or diamond-like thin film has a Vickers hardness Hv of at least 5,000 kg/mm 2 , and usually of about 6,000 kg/mm 2 or above (refer, e.g., to TRC News, January 1987, Vol. 6-1, page 7, published by Torey Research Center and Journal of Applied Physics of Japan, Vol. 55, No. 7 (1986), page 640).
The diamond-like thin film produced by a vapor phase process has great hardness and outstanding wear resistance, durability, and resistance to corrosive and other attacks. Also it can form coatings on articles of whatever shapes desired. It is therefore useful as protective coatings for articles that require at least one of those beneficial properties.
Methods of manufacturing diamond-like thin films by the vapor phase process are varied (refer, e.g., to HYOMEN KAGAKU (Surface Chemistry), vol. 5, No. 108 (1984), pp. 108-115 "Various methods"). Diamond-like thin films are extensively used as corrosion- and abrasion-resistant protective films over the surfaces of variously shaped articles that need to be protected.
The diamond-like thin films are capable of being bound solidly to substrates of silicon or the like. However, they are not as adhesive to certain types of article substrates and have a common problem of easily coming off from those substrate surfaces upon subjection to external forces. The shortcoming makes the films unable to be fully effective as protective coatings for applications where corrosion resistance or wear resistance is of essential importance. In particular, Fe metals and alloys (e.g., soft steel "STC", stainless steel, and hardened steels "SKD", "SKS"), alloys of other metals such as Co and Ni, glass, and ceramics are known to produce weak bonds between themselves and diamond-like thin films. Iron-based substrates, such as structural and sliding parts, are of the highest industrial utility. Glass and ceramics too have a broad range of applications including sliding members of thermal heads. It is therefore important to improve the adhesiveness of diamond-like thin films to these substrate surfaces on which they are to be formed.
Pretreatment of such substrates has been taught, e.g., by Japanese Patent Application Public Disclosure Nos. 200898/1985, 204695/1985, and 174376/1986.
The molds or dies for injection molding, extrusion, compression molding, etc. of glass and plastics have hitherto been made from cemented carbides. The materials are expensive and require much time and cost to procure and fabricate into the objects. Susceptibility to cracking due to the lack of toughness is another disadvantage. The brittleness of the cemented carbides has to be compensated for and their abrasion resistance be enhanced. To this end, it has been proposed to coat the frictional or sliding surfaces of metallic molds protectively with diamond-like thin films, e.g., by Japanese Patent Application Public Disclosure Nos. 15169/1990, 22012/1990, and 15170/1990. However, the diamond-like thin films do not bind firmly enough to the metallic mold substrate surfaces and, being aggregates of microcrystals, they easily separate from the mold surfaces by dint of external forces. They, therefore, have not proved fully satisfactory as protective coatings for applications where resistance to corrosion and abrasion is essential.
Hardened steels, on the other hand, are available at lower cost and do not require much time and cost for fabrication but the resulting mold surfaces are worn faster and hence have shorter life. The drawback could be overcome by coating the surfaces with a diamond-like thin film formed by a vapor phase process, as proposed, e.g., by the above-mentioned Patent Application Public Disclosure Nos. 15169/1990, 22012/1990, and 15170/1990. However, by the same token, the binding force is insufficient. There are other approaches to the manufacture of diamond-like thin films (refer, e.g., to HYOMEN KAGAKU (Surface Chemistry), vol. 5, No. 108 (1984), pp. 108-115 "Various methods"). Those methods generally require as high a substrate temperatures as 600° C. or upwards, which can anneal the hardened steels and impair the hardness of the resulting molds.
Patent Application Public Disclosure No. 200898/1985 recommends ion etching of a Co-WC alloy substrate surface by direct action of glow discharge before a diamond-like thin film is formed on the surface as a high-hardness film. Since no accelerating voltage is applied, the etching efficiency is not adequately high from the standpoint of enhanced adhesion. Thus the improvement in adhesion to which the present invention is directed is not satisfactorily achieved. Patent Application Public Disclosure No. 204695/1985 likewise aims at an increase in the film-forming rate. The end is attained by introducing Ar gas into a reduced-pressure chamber, applying a voltage across positive and negative electrodes to produce a plasma, and then subjecting a substrate to the plasma action. The plasma ion concentration being low, the etching effect is rather limited for the improvement of adhesion. Public Disclosure No. 174376/1986 intends to improve the adhesion of substrates by treatment with plasma gas and then by oxidation treatment to form an oxide coating. The plasma requires diffusion in the first place so that the positive ions can pass through the positive-potential grid. This makes it impossible for a sufficient amount of positive ions to form a film to reach the substrate, thus rendering the process inefficient. The prior art methods thus have failed to produce a diamond-like thin film with adequately high bond between the film and the substrate. Patent Application Public Disclosure No. 80190/1991 teaches bombardment of a substrate surface with an accelerated ion beam. The technique is advantageous over those described already but is still unable to bring an adequately enhanced adhesion.
Patent Application Public Disclosure No. 174508/1984 sets out the ionization evaporation technique that is utilized in the present invention. The reference specification describes that a thin film of Si, Ti or the like is formed as an intermediate layer over a basis metal plate of Ni, Cu, Fe, Co or the like, and then a diamond-like film is formed thereover to provide a Vickers hardness of about 5000. However, the bases of bulk materials such as iron and steel that contain Fe, Co, etc. and stainless steel are not adequately receptive to the application of the coatings, and the coating film of Si or the like does not achieve satisfactory adhesion strength.
U.S. Pat. No. 4,753,414 (to McCandless) uses RF plasma in forming a carbonaceous coating film over a base. According to a paper written by the inventor and cited in the patent specification, the RF plasma method produced a Vickers hardness of only about 1850. The patent process, therefore, is unable to yield the diamond-like film of the present invention. In addition, the same patent is silent on any intermediate layer.
On the other hand, U.S. Pat. No. 5,112,025 claims that a diamond film can be directly formed on a plating film of Ni, with allegedly ample adhesion. However, the fact is the adhesion is "ample" in the sense that the plating film is capable of withstanding a molding pressure of at most about 400 kg/cm 2 . Apart from this, Ni is originally a hardly adherent metal.
U.S. Pat. No. 4,490,229 (to Mirtish) teaches activating a base by bombardment with neutral Ar to increase the adhesion of a diamond-like film to the base surface. In the absence of accelerating means for the bombarding gas, however, the activation of the base surface is not sufficient for attaining full adhesion, and hence the hardness is unsatisfactory.
None of these printed publications of the prior art suggest that the use of a low-hardness carbonaceous film as an intermediate layer makes it possible to form an excellently adherent and hard diamond-like film on a bulk metal such as stainless steel or steel containing Fe, Co, etc.
In view of the above, we proposed in Patent Application 142678/1991 the use of an Mo intermediate layer for added adhesiveness. The intermediate layer was found to produce very great binding power. We tried other substances for the intermediate layer and attained results comparable to or even better than those of the patent application. Crystalline silicon carbide, nitride, etc. have also been known to form intermediate layers. However, the prior art methods and that of our copending application require the formation of an intermediate layer of a material dissimilar to that which gives the diamond-like film, with a consequent increase in the total number of process steps required. Moreover, the resulting intermediate layers are not fully acceptable yet.
It is therefore an object of the present invention to provide in a relatively simple way articles protected with a diamond-like thin film which is strongly bound to and highly adhesive to the substrate and exhibits improved peeling resistance and durability.
Another object of the invention is to manufacture highly wear-resistant metallic molds from inexpensive hardened steel. Hardened steel has such low thermal resistance and poor adhesion to diamond-like thin films that they have been unable to give diamond-coated metallic molds with industrially adequate wear resistance. Patent Application No. 214913/1989 discloses a technique of forming a diamond-like film by bombardment of a substrate with Ar ions and subsequent ionization evaporation to provide protection for metals and ceramics. It does not teach, however, the application of the technique to the fabrication of metallic molds from hardened steel.
SUMMARY OF THE INVENTION
The invention provides protectively coated articles comprising a substrate of ordinary character, of course, or a substrate, such as of a metallic mold, selected from the group consisting of alloys, e.g., a hardened steel, which contain at least Co, Ni, or Fe, ceramics, and glass, the substrate having a slight affinity for a diamond-like thin film, an intermediate carbon layer formed on the substrate surface, the intermediate layer having a hardness Hv in the range from 1000 to 5000 kg/mm2, or harder than the substrate but less hard than a diamond-like thin film to be formed thereon, and a diamond-like thin film formed as the outer layer. Preferably, the intermediate layer according to the present invention is made harder stepwise or continuously from the side facing the substrate toward the diamond-like thin film.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic view, in vertical section, of an ionization evaporation apparatus for use in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
According to this invention, a substrate is coated with an intermediate carbon layer having a greater hardness than the substrate but less than that of the diamond-like thin film to be formed thereon, through control of the deposition conditions of ionization evaporation, and then the diamond-like thin film is formed without changing the material hydrocarbon and using the same ionization evaporation technique excepting changes in the film-forming conditions. It is particularly desirable to change the film-forming conditions for the intermediate layer too, either stepwise or continuously, so that the hardness of the intermediate layer increases from the side facing the substrate toward the diamond-like thin film.
For the formation of the intermediate layer, the ionization evaporation as described in Patent Application Public Disclosure Nos. 174507/1983 and 234396/1989 is utilized. According to the method, the formation of the intermediate layer is immediately followed by that of a diamond-like thin film without exposing the intermediate layer or interrupting the operation but by simply altering the film-forming conditions for the fabrication of the diamond-like film. Consequently, the method of the present invention is highly efficient. The process is preferably preceded by a pretreatment in which the substrate is placed in a vacuum chamber of the film-forming apparatus, a bombarding gas, such as of Ar, is introduced into the chamber and is ionized by ionization means comprising a thermionic cathode filament unit and a counter cathode disposed around the unit, and the resulting ion stream is accelerated by a grid at a lower potential than the counter electrode to bombard and activate the substrate surface.
While an intermediate layer of a uniform composition harder throughout than the substrate and less hard than the diamond-like thin film is acceptable, it is preferably of such a composition that the hardness is low on the side facing the substrate and high on the diamond side. The latter improves the binding and adhesive properties of the layer. Both the intermediate layer and the diamond-like thin film can be formed using the same ionization evaporation apparatus and from the same material, with the only exception that the evaporation conditions are changed continuously or stepwise. The thickness of the intermediate layer is desirably between 0.02 and 3 μm, more desirably between 0.05 and 0.5 μm. A too thin layer is not effective but a too thick layer produces a saturated effect.
The hardness of the diamond-like thin film formed by ionization evaporation is about 6000 kg/mm 2 or above. The hardness of the article that constitutes the substrate varies with the material but usually ranges from 200 to 3000 kg/mm 2 . This means that the hardness of the intermediate layer may be chosen from the range intermediate between those of the substrate material and the diamond-like thin film, i.e., from between 1000 and 5000 kg/mm 2 .
The diamond-like film having a Vickers hardness over 5,000 kg/mm 2 and usually over 6,000 kg/mm 2 has a clear Raman's absorption peak at about 1,550 cm -1 while the intermediate layer having a Vickers hardness of less than 5,000 kg/mm 2 shows a weaker peak at about 1,550 cm -1 which disappears with decrease in the hardness as shown at pages 78 and 79 of Journal of the Ceramic Society of Japan, International Edition, Vol. 98, pp. 607-608 (1990), and at page 7 of TRC News 18, (1987).
To form an intermediate layer by ionization evaporation, either a singular or mixed gas is used. To form a diamond-like thin film, the ionization evaporation process comprises ionizing a hydrocarbon feed gas or a feed gas capable of giving a hydrocarbon upon decomposition or reaction by ionization means, such as arc discharge between a thermionic cathode filament unit and a counter cathode or thermionic emission between a thermionic cathode filament unit and a counter cathode and accelerating the resulting ion beam with an electric field and directing it toward a substrate to form a diamond-like thin film thereon. (The term "hydrocarbon" as used herein means a saturated hydrocarbon, such as methane, ethane, or propane, or an unsaturated hydrocarbon, such as ethylene, propylene, or acetylene, etc. The "feed gas capable of giving a hydrocarbon upon decomposition" is, e.g., an alcohol, such as methyl alcohol or ethyl alcohol, or a ketone, such as acetone or methyl ethyl ketone. The "feed gas capable of giving a hydrocarbon upon reaction" is, e.g., carbon monoxide and a mixed gas of carbon dioxide and hydrogen. Such a feed gas may contain at least one chosen from among rare gases, such as helium, neon, and argon, or from among hydrogen, oxygen, nitrogen, water, carbon monoxide, carbon dioxide, etc.) The details of the process are described in Patent Application Public Disclosure Nos. 174507/1983 and 234396/1989. The intermediate layer can be formed by the film-forming procedure for the diamond-like thin film with the exception that film-forming energy level is lowered.
There is shown in FIG. 1 a preferred embodiment of a film-forming apparatus according to Patent Application Public Disclosure No. 174507/1983. Other known ionization evaporation apparatus may, of course, be employed instead. The numeral 30 designates a vacuum vessel and 31 a chamber communicated with an evacuation system 38 to be evacuated up to a high vacuum of about 10 -6 Torr. An electrode 32 is located at the back of a substrate S such as a metallic mold and kept at a negative potential Va. A mask 42 is provided close to or in contact with the front surface of the substrate S, with a window for controlling the size and shape of the diamond-like thin film to be formed. While the mask may be in contact with the substrate, it is preferably located away from the latter so as to reduce the peripheral thickness of the film and decrease the risk of cracking. Indicated at 33 is a grid supplied with the same negative potential Va as for the substrate so as to be used in accelerating the hydrocarbon ions during the film-forming process. To enhance the continuity of the film and smoothen its surface, the grid 33 to be used has a properly chosen porosity (the total area of openings per unit area) and opening density (the number of openings per unit length). It may be equipped with means for causing planar vibrations. A thermionic cathode filament unit 34, kept at a negative potential Vd, is heated by a current If from an AC source to emit thermions. The numeral 35 indicates an inlet for the feed gas, 37 a gas feed passage, and 37' a plasma excitation chamber. An anode 36 surrounds the filament unit 34. The anode, while being grounded in this case, maintains a voltage Vd positive to the filament unit and is given a positive potential Va for the electrode 32 and grid 33. A solenoid 39 is disposed around the filament unit 34, anode 36, and feed inlet 35 so as to be excited by a current Ic from a power supply Vc to produce a magnetic field for the containment of ionized gas. Thus, the quality of film being formed can be modified by adjusting If, Vd, Va, and the solenoid current Ic. Above all, the control of Va (substrate voltage) and Vd (potential difference between the thermionic cathode and the anode) gives good result.
Controlling these film-forming conditions can be easily done under programmed computer control.
The film-forming procedure is as follows. The vacuum chamber 31 is evacuated to about 10 -6 Torr and a valve on the gas feed line 37 is manipulated to admit a gas for forming an intermediate layer or a gas for forming a diamond-like film, or, in some cases, its mixture with hydrogen gas, or with Ar, He, Ne, or other carrier gas, all at predetermined rates, into the chamber through the inlet 35. With concurrent adjustment of the evacuation system 38, a desired gas pressure, e.g., 10 -1 Torr, is secured. Meanwhile, the plurality of thermionic cathode filaments 34 are heated by passage of the AC current If, and the differential potential Vd is applied between the filament unit 34 and the anode 36 to produce a discharge. Feed gas fed via the inlet 35 is thermally decomposed and collides with the thermions from the filaments to give positive ions and electrons. The electrons, in turn, collide with other thermally decomposed particles. This phenomenon is repeated under the containment action by the magnetic field of the solenoid until the feed gas is totally converted to positive ions of the thermally decomposed substance. The positive ions are attracted by the negative potential Va applied to the electrode 32 and the grid 36 and accelerated toward the substrate S. They thus impinge on the substrate and, through a film-forming reaction, produces a diamond-like thin film thereon.
As for the potential, current, temperature and other conditions for the parts involved, refer to the above-given data and also to the printed publications of the above-cited patent applications.
The present invention is illustrated by the following examples.
EXAMPLES
By ionization evaporation were formed intermediate layers on substrates of articles made of SKD11 (hardened steel), SKS2 (hardened steel), and quartz glass ("SUPRASL", the trade designation of a Shin-Etsu Quartz product) under the conditions given in Table 1 and then formed thereon diamond-like thin films again under the conditions given in Table 1.
The filament unit 34 in this case consisted of a coiled filament 3 mm wide, and the gap between the filament and the surrounding electrode 36 was fixed to 8 mm. The grid 33 was vibrated at the rage of 5 mm/min.
The filament current If was 25 A, the filament voltage Vd was made variable, the substrate voltage Va too was variable, and the magnetic flux density of the solenoid was 300 G. Under these conditions, CH 4 was introduced, and intermediate layers of varied film thicknesses and then diamond-like thin films 30 μm thick were formed thereon.
TABLE 1______________________________________ IntermediateIntermediate layer 2layer 1 (diamond-like Diamond-like(substrate side) thin film side) thin filmIf Vd Va If Vd Va If Vd Va______________________________________Ex. 1 25 -20 -300 -- -- -- 25 -30 -900Ex. 2 25 -20 -300 25 -30 -500 25 -30 -900Ex. 3 25 -20 -500 25 -30 -700 25 -30 -800Ex. 4 25 -15 -300 25 -35 -500 25 -30 -700Comp. -- -- -- -- -- -- 25 -30 -800Ex.______________________________________
The properties of the protective films formed on the articles thus obtained are given in Table 2.
The adhesion strength and scratch hardness values were evaluated as follows. The adhesion strength was determined by bonding a test diamond-like thin film with epoxy resin to a square bar 1 cm 2 by 10 cm long and then peeling the film from the bar on a tensile tester (trade-named "Tensilon"). The scratch hardness was determined by means of a Scratch Tester, Model CSR-02 manufactured by Rhesca. The values are relative to the standard values given in the first row of Table 1.
__________________________________________________________________________Intermediatelayer Diamond-Substrate Diamond like Substrateside film side thin film SKD11 Quartz glass SKS2Thick- Hard- Thick- Hard- Thick- Hard- Scratch Scratch Scratchness ness ness ness ness ness Adhesion hard- Adhesion hard- Adhesion hard-μm Hv μm Hv μm Hv strength ness strength ness strength ness__________________________________________________________________________Ex. 1 0.1 2500 -- -- 3.0 6000 1.0 1.0 1.0 1.0 1.0 1.0Ex. 2 0.1 2500 0.1 4000 3.0 6000 1.3 1.2 1.4 1.2 1.4 1.2Ex. 3 0.03 3000 0.03 5000 3.0 5800 0.8 0.7 0.9 0.8 0.9 0.8Ex. 4 0.01 2000 0.01 4000 3.0 5500 0.6 0.5 0.6 0.6 0.6 0.6Comp. No intermediate layer 3.0 5400 0.1 0.2 0.09 0.08 0.1 0.1Ex.__________________________________________________________________________
Also, the number of shots endurable with each of metallic molds of hardened steel SKD11 for molding ferrite cores 20 mm in diameter was measured. The results are shown in Table 3.
TABLE 3______________________________________Intermediatelayer Diamond-Substrate Diamond likeside film side thin filmThick- Hard- Thick- Hard- Thick- Hard- No. ofness ness ness ness ness ness shotsum Hv um Hv um Hv endurable______________________________________Ex. 1 0.1 2500 -- -- 3.0 6000 80,000Ex. 2 0.1 2500 0.1 4000 3.0 6000 100,000Ex. 3 0.03 3000 0.03 5000 3.0 5800 70,000Ex. 4 0.01 2000 0.01 4000 3.0 5500 60,000Comp. No intermediate 3.0 5400 5,000Ex. layer______________________________________
The intermediate layer according to the invention makes it possible to apply a diamond-like thin film to the substrates of molds and other articles normally difficult to bind with it and thereby substantially improve the durability of the articles. | A protectively coated article comprises a substrate of a material selected from the group consisting of alloys containing at least Co, Ni, or Fe, ceramics, and glass and which has only a slight affinity for a diamond-like thin film, an intermediate carbon layer formed on the substrate, the intermediate layer having a hardness Hv in the range from 1000 to 5000 kg/mm2, or harder than the substrate but less hard than a diamond-like thin film to be formed thereon, and a diamond-like thin film formed further thereon. The interposition of the intermediate layer permits the diamond-like thin film to be bound securely to a substrate surface which has a slight affinity for the film. | 8 |
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to de-mountable sunshade canopy structures and in particular sunshade canopies for ultraviolet (UV) sun ray protection of childrens' play areas.
[0002] It is increasingly acknowledged that physically challenging outdoor play structures are of benefit to the physical and emotional development of young children. A code of safety specifications for the construction and maintenance of childrens' play structures has been developed by National Play and Playground Authorities, published (1996) by the National Recreation and Park Association Arlington, Va. These construction specifications describe construction features for support of childrens' slides, swings, climbing apparatus, etc. which minimize risk of injury to children engaged in all manner of predictable use and misuse of the play structures.
[0003] The specifications require that the play structures be mounted on a platform or on towers elevated up to six feet above a resilient (non-hardened) surface such as cork or rubber panels, and the towers or platform be supported by a very limited number of support columns. The columns are to be capped at the top and without exterior fittings on which a child could be caught or injured while climbing upon or falling from the platform or tower. The support columns are capped at the top to discourage a child from climbing or holding on suspended from the column top. The vertical support columns have been in the past a source of injures to children engaged in unintended use of these structures. Accordingly, the minimum number of vertical support columns, all free of hand or foot holds, has become a specification for acceptable safe design.
[0004] Separate from the safe construction design specifications referred to above which have and are significantly reducing playground injuries there is a growing theat to childrens' health when they are engaged in outdoor play and exercise in the sun shine.
[0005] The earth's protective atmosphere ozone layer has been significantly depleted due to release of chemical pollutants into the atmosphere during the last five decades. The result of the ozone depletion is that the solar ultraviolet (UV) rays are significantly more intense and comprise a serious health risk to children without protection when playing in the now unfiltered UV sun radiation.
[0006] In 1930 the risk of developing melanoma from sun exposure was 1 in 1500 people. Today a person's risk of developing skin cancer at some time during their life as a result of UV exposure is 1 in 75 people. Skin cancer is the most common cancer in the United States, with more than one million new cases diagnosed each year. Currently this year 47,700 Americans will be diagnosed with life threatening melanoma and 7,700 will die of the disease. The current prognosis for this disease is that approximately 1 out of 5 children in the United States will experience some form of skin cancer during their lifetime. Furthermore, exposure to the current intensity of solar UV radiation reduces the effectiveness of the immune system. This effect is of special importance in children's health.
[0007] Sources of the above statistics are to be found in publications of the American Academy of Dermatology, American Cancer Society, National Institutes of Health, U.S. Center for Disease Control and Protection and the Australian Cancer Society.
OBJECTS OF THE INVENTION
[0008] It is a first object of our invention to provide a sturdy, wind resistant, demountable canopy structure suitable for shading a childrens' play area from direct rays of the sun.
[0009] Another object of our invention is to provide a sturdy, wind resistant, demountable sun shade canopy for mounting on vertical support columns as used in childrens' standard safe outdoor play structures. The sun shade canopy structure as described herein, is in full compliance with recommended safety specifications for childrens' play areas.
[0010] Still another object of our invention is to provide a sturdy, wind resistant, demountable sun shade canopy design adaptable to retrofit existing small area and extended childrens' play area installations with effective sun shade protection.
[0011] These and other objects and advantages and diverse uses of our invention will be apparent from consideration of the following illustrations, specifications and claims.
BRIEF SUMMARY OF THE INVENTION
[0012] A demountable, wind resistant sun shade canopy suitable for mounting on a limited number of vertical columns, erected for the purpose of, or suitable for mounting on, extensions of a limited number of standard safe play area support columns. The canopy support structure, comprised of a plurality of uniquely shaped brackets which, when each is fixedly mounted, respectively, to the top of a vertical column, provides at each column a mount for a cantilever extending outward toward the perimeter of the area to be shaded, and simultaneously provides for mount of a hip beam extending toward the inner portion of the area to be shaded. Thus an extended-area rigid support structure is provided over a designated area which may be dependably shaded from the sun rays when a high density knitted polyethylene porous canopy cover is placed over the unique bracket supported plurality of cantilever and hip beam support members and secured about the perimeter of the canopy cover with an adjustable tension means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is a perspective view of a portion of an existing safe play structure without sun protection; the play structure is shown mounted above a resilient ground cover.
[0014] [0014]FIG. 2 is a cross section of the upper portion of a support column taken along the plane 2 - 2 .
[0015] [0015]FIG. 3 is a plane view of a specified safe design single tower childrens' play area on which our innovative sun shade canopy has been erected; the play and exercise devices are shown in phantom lines.
[0016] [0016]FIG. 4 is a sectional elevation view of the embodiment of our invention shown in FIG. 3 with portions of the play structures and canopy support members shown in phantom.
[0017] [0017]FIG. 5 is a perspective view of a construction bracket for mounting cantilever beam and hip beam members to form a support structure for mounting the canopy cover.
[0018] [0018]FIG. 6 is a cross section of the construction bracket shown in FIG. 5 taken on the plane 6 - 6 .
[0019] [0019]FIG. 7 is a plane view of the connector for the four hip beam canopy support members shown in the embodiment of our sun shade canopy illustrated in FIGS. 3 and 4.
[0020] [0020]FIG. 8 is a perspective view of the hip beam connector illustrated in FIG. 7.
[0021] [0021]FIG. 9 shows detail of means for fastening the canopy cover to the support structure with adjustable tension means.
[0022] [0022]FIG. 10 shows a section of an extended end of the cantilever member showing means for securing the canopy cover.
[0023] [0023]FIG. 11 is an elevation view of a second embodiment of our sun shade canopy structure mounted to cover a two tower specified safe children's play area.
[0024] [0024]FIG. 12 is a plane view of the embodiment of our sun shade canopy shown in the embodiment illustrated in FIG. 11. The children's play area devices are shown in phantom.
DETAILED DESCRIPTION OF THE INVENTION
[0025] A safe design childrens' play structure is illustrated in FIG. 1 wherein a plurality of fixedly mounted vertical columns 12 a , 12 b , 12 c and 12 d are shown. The columns 12 a , 12 b etc. are mounted in foundations (not shown) beneath a resilient ground cover 14 . The ground cover may be made of rubber or cork matted materials to soften impact and reduce injuries to a child falling thereon.
[0026] The columns support a platform 16 from which a slide 18 , a closed chute 20 and other childrens' climbing and exercise devices may be positioned.
[0027] The upper end of conventionally designed vertical columns 12 a , 12 b , 12 c , 12 d is shown in FIG. 2 in cross section on plane 2 - 2 . A column cap 22 fits over the top of the column 12 d . The cap 22 is shaped with a reduced diameter lower section 24 which, when inserted into the hollow opening 26 of the vertical column, comprises a secure mount for the column cap. Although such conventionally designed columns are fully compatible with the invention, in order to avoid the possibility of rainwater leaking into the seam between lower portion 24 and column 12 d , it is preferable to have the columns designed as depicted in FIG. 6, where the upper end of column 12 a , 12 b , etc. has a smaller diameter than bracket 52 so that rainwater will flow over the juncture between the two without entering the seam.
[0028] [0028]FIGS. 1 and 2 are illustrative of safe childrens' play structures in compliance with the safety specifications developed by the National Play and Playground Authorities, At this date there are tens of thousands of such play structures erected and being erected in the United States without provision for effective sun shade for children using such structures.
[0029] A plan view of a first embodiment of our invention is shown in FIG. 3 wherein a canopy cover 30 is shown supported over structural members described below which in turn are mounted above a children's play structure area. Children's exercise and play devices are shown at 32 in phantom lines below the canopy 30 .
[0030] A cross section elevation of the FIG. 3 embodiment is shown in FIG. 4 taken on plane 44 . Vertical columns 34 and 36 are fixedly mounted respectively in concrete foundation footings 40 and 42 . The vertical columns support a platform or deck 44 . The columns 34 , 36 terminate at approximately four feet above the platform or deck 44 . Caps 22 such as shown in FIG. 2 have been removed from the upper column portions 60 , 62 of the columns 34 , 36 exposing the tops 48 , 50 respectively, of columns 34 and 36 . Structural bracket fittings 55 and 57 have lower ends 56 , 58 , which, fit over the tops 48 , 50 of columns 34 and 36 .
[0031] [0031]FIGS. 5 and 6 are illustrative of the structural brackets fittings 55 and 57 ; more specifically, FIG. 5 depicts bracket 55 in a perspective cut-away fragmentary view while FIG. 6 is a view of the structural bracket 55 shown as a cross section on plane 6 - 6 . In preferred embodiments, the lower portion 56 of structural bracket 55 fits over the reduced diameter upper end 52 of the upper column portion 60 . In rainy weather, water will flow over the juncture of lower portion 56 and upper end 52 and will not enter the seam where it might cause damage.
[0032] The upper end of the bracket is terminated with a transverse angularly mounted cylindrical rod 64 . The rod 64 is mounted at an acute angle with the vertical cylinder extension. The angle with the horizontal is normally 22 degrees, but is subject to adjustment as required for specific application.
[0033] Mounted as shown in FIG. 5 and FIG. 6, the cylindrical rod 64 has an upper, or first end 68 , and a lower, or second 70 , end. Hip beam 72 comprises a straight section of a hollow metal steel pipe or rod. The hip beam 72 is positioned over the upper, or first end 68 , of the angle mounted cylindrical rod 64 and secured with threaded bolt means 76 passed through the hip beam 72 and the cylindrical rod 64 .
[0034] The lower or second end 70 of the solid metal rod 64 is mounted over a cantilever beam 80 comprised of a straight section of hollow steel pipe at its upper end and secured with threaded means 81 . The lower end of the cantilever beam is terminated with an oblong eyelet connector 84 .
[0035] As shown in fragment view in FIGS. 7 and 8 the four hip beams 72 , 74 and counter parts 72 a , 74 a terminate in juxtaposition and are secured together with a right angle joint 86 .
[0036] Referring now to FIG. 3, a porous woven polyethylene canopy cover 30 is placed over the structure comprised of hip beam members 72 , 72 a , 74 , 74 a , and cantilever beam members 80 , 80 a , 82 , 82 a . The canopy details are more clearly shown in FIG. 9. The canopy cover 30 is secured about its perimeter with a tension cable 90 which is secured within a cable channel 92 sewn about the canopy perimeter 94 . The tension on the cable 90 is adjusted and maintained with a turnbuckle 96 . The canopy cover 30 is provided at its four corners with a reinforced opening 98 through which the oblong eyelet connector 84 located on the extreme end of the cantilever beam 80 and its counterpart cantilever beams 82 , etc. protrudes.
[0037] A second embodiment of our invention is illustrated in FIGS. 11 and 12 wherein a two tower safe design children's play area is shown. The play and exercise devices are shown in phantom lines. A porous shade canopy 104 fabricated with woven polyethylene strips is constructed similarly to the single tower canopy cover 30 . The two tower canopy cover 104 is sewn so that it provides a cable channel 106 . A tension cable 108 is threaded through the channel 106 and when positioned over the metal support structure of hip beams 110 a , 110 b , 110 c , etc. ridge beam 112 and cantilever beams 114 a , 114 b , 114 c , etc. forms a sunshade canopy. A turnbuckle tension means 116 is attached to the ends of the cable 108 to provide adjustment and to maintain cable tension.
[0038] The canopy cover 104 is provided at each corner with a reinforced opening 98 as shown in FIG. 9, through which the oblong eyelet connector 84 on the cantilever beam extends.
[0039] The purposes and other advantages to our invention and possible application to sun sheltering purposes beyond those described in connection with children's play areas will be apparent from the following claims. | A demountable, wind-resistant sun shade canopy for shading childrens' play areas or other actively used areas. The canopy cover, being removably secured over a metal support structure, is comprised of vertical columns upon which are mounted at the upper end thereof respectively, uniquely configured bracket fittings, each bracket fitting providing secure mounting for a cantilever beam extending outwardly toward the perimeter of the area to be shaded, and providing secure mounting for a hip beam extending upward and toward the inner portion of the area to be shaded. | 4 |
TECHNICAL FIELD
[0001] Embodiments of the invention generally relate to the field of recording, managing and linking annotations to a set of data and, more particularly, to a method and system for managing unstructured data in a structured data environment.
BACKGROUND
[0002] It is often desirable to associate unstructured information such as notes with data objects. Such notes may include a description of the contents of the data objects, instructions or comments to people working with the data objects, project notes, etc. There are also scenarios when a user needs to gather the unstructured information with respect to a transaction and then later convert this unstructured information into structured data. An example of the above scenario may be a customer service executive on a service call with a customer. Due to time and resource limitations the executive may not always able to capture and document the entire conversation with the customer as structured data. Thus, the executive may require an easy way to capture the conversation as unstructured data and then convert it into structured data at a later time.
[0003] Another example of the above scenario may be an employee of an organization on a business tour. The employee may not want to record all of the transactions as structured data such as taxi charges, hotel charge etc immediately after each transaction. The employee may prefer to store the transactions as unstructured data and generate structured data referring the pre-recorded unstructured data at a later stage (e.g., after trip completion).
[0004] Systems are available which enable users to generate unstructured data by way of notes or annotations. For example, these systems allow a user to record a number of notes and store them in a generic pool without any association. The user may then refer the generic pool of notes and search for the required information by navigating and reading each note. This is a very tedious process and consumes lot of time.
[0005] There are also systems available which allow a user to generate and link notes to user interface UI screens. Thus when the user navigates to a UI screen, the notes linked to the screen are retrieved and displayed. Although these systems allow linking notes to UI screens, they do not allow linking to the underlying data displayed in the screens.
[0006] There are also systems in which text input fields are provided to enable a user to enter and save text information for later reference. These input fields are hard coded and customized for a particular application. However, these systems do not allow the user to record and attach notes in various formats such as voice, video, presentation, spreadsheet, pictures, etc. Further, as the input fields are customized for a particular application, they are not used to record notes across applications.
SUMMARY OF THE INVENTION
[0007] Embodiments of the invention are generally directed to a method and system for managing unstructured data within a structured data environment. A data identifier ID is provided for a set of data. Unstructured data is created and then mapped to the data identifier ID. The unstructured data mapped to the data identifier may then be retrieved and displayed.
[0008] These and other benefits and features of embodiments of the invention will be apparent upon consideration of the following detailed description of preferred embodiments thereof, presented in connection with the following drawings in which like reference numerals are used to identify like elements throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The claims set forth the embodiments of the invention with particularity. The embodiments of the invention, together with its advantages, may be best understood from the following detailed description taken in conjunction with the accompanying drawings. The invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
[0010] FIG. 1 illustrates a functional block diagram of a system for generating and recording unstructured data such as pin-up notes according to one embodiment of the invention.
[0011] FIG. 2 illustrates a preferred implementation of the functional block diagram in FIG. 1 according to an embodiment of the invention.
[0012] FIG. 3 illustrates a flow diagram to explain the high level process flow for unstructured data retrieval and generation according to a preferred embodiment of the invention.
[0013] FIG. 4 illustrates a flow diagram to explain the process flow during unstructured data generation and mapping in accordance with a preferred embodiment of the invention.
[0014] FIG. 5 illustrates a flow diagram to explain the process flow during unstructured data retrieval according to a preferred embodiment of the invention.
[0015] FIG. 6 illustrates an exemplary block diagram of a system useful for implementing one embodiment of the invention.
[0016] FIG. 7 illustrates a format in which the unstructured data is stored in the database according to a preferred embodiment of the invention.
DETAILED DESCRIPTION
[0017] FIG. 1 illustrates a functional block diagram 100 of one embodiment of a system for generating and recording a particular type of unstructured data, referred to herein as “pinup notes,” which may be in any unstructured data format supported by the system (e.g., text data, voice recording, video recording, a presentation format, a spreadsheet format, etc). Although the remainder of this detailed description will use the term “pinup notes,” it should be noted that the underlying principles of the invention are not limited to any particular type of unstructured data. In FIG. 1 , a container application 101 acts as a portal for a number of other applications. The container application has its own GUI 102 (Graphical User Interface) to enable a user to interact with the system. The container application 101 at any time may access and act as a host to more than one application upon user request. Applications 140 and 150 may be accessed by the container application 101 upon user request. Thus the container application 101 acts as an interface between the user and applications 140 and 150 , enabling the user to access more than one application through one GUI 102 . Each application 140 and 150 has business logic 160 and 170 , respectively, associated with it. The business logic 160 and 170 may comprise of a number of data objects (also called “business objects” or “business object types”). For example, data object 161 is a part of business logic 160 associated with application 140 and data object 170 is a part of business logic 170 associated with application 150 . The applications 140 and 150 have their own GUIs 141 and 151 , respectively. GUI 102 may provide the user with a means to select data objects which are part of business logic 160 and 170 . For example, if the user requests access to the data object 161 which is a part of business logic 160 through GUI 102 , the container application 101 invokes the application 140 and retrieves and displays its GUI 141 . The user then effectively works on GUI 141 to access the data objects associated with business logic 160 . Thus, the container application 101 acts as a host to application 140 and GUI 102 acts as a host to GUI 141 . The container application 101 is further coupled to a pin-up notes infrastructure 120 which enables generation, retrieval, mapping and management of unstructured data in the form of pinup notes.
[0018] An example of a container application 102 may be the corporate portal for an organization. Applications 140 and 150 may be applications such as employee services, organization portfolio, address book, help, etc., hosted by the organization portal. GUI 102 may be the user interface for the portal and GUIs 141 and 151 may be the user interface screens of each of the applications 140 and 150 . Assuming that application 140 is an application for management of employee services in an organization, using this application, a user may access all, or a subset of, the employee services offered by the organization. Each of the employee services such as compensation, travel services, orders and purchases, vacation and time-off, IT services etc is a data object such as object 161 . An employee may access any of the business object types and create multiple instances of each type. For example if the employee accesses the business object types “vacation” and “time off,” an object instance is generated for each. The GUI screens 141 and 151 , object types 161 and 171 and instances of each object type have unique identification codes (“IDs”) associated with each of them.
[0019] The pin-up notes infrastructure 120 retrieves IDs of currently active application UI screens, object types or object instances. The pin-up notes infrastructure 120 may retrieve the IDs by either querying the container application 101 or by querying the active applications such as 140 and 150 directly. If the container application 101 or the applications 140 and 150 are not queryable, in one of the embodiments of the invention, the pinup notes infrastructure may include a special adapter for retrieving IDs of non-queryable applications.
[0020] The pin-up notes infrastructure 120 enables a user to record and manage unstructured data in the form of pin-up notes. As mentioned above, a pin-up note may be in any format supported by the system such as text data, voice recording, video recording, a presentation, a spreadsheet, etc. The user may generate a pin-up note in any of the supported formats and map it to a UI screen ID, object ID or an object instance ID. In one of the embodiments of the invention the user creates a pin-up note and then selects the data to which the pin-up note is to be mapped. The pin-up note infrastructure 120 then retrieves the ID of the selected data and maps the pin-up note to the ID. The pin-up note infrastructure 120 then stores the pin-up note along with its associated ID in the pin-up notes storage 131 . FIG. 1 shows pin-up notes 121 and 123 after mapping with respective IDs. Categories 122 and 124 identify the types of IDs the notes are mapped to such as a UI screen ID, object ID or object instance ID.
[0021] In another embodiment of the invention the pin-up note infrastructure 120 automatically retrieves the IDs of a currently active or selected screen, data objects or object instances. The pin-up note infrastructure 120 then searches for the pin-up notes mapped to the retrieved IDs in the pin-up notes storages, retrieves them and displays them on the GUI 102 .
[0022] In one embodiment, the pin-up notes infrastructure 120 operates transparently to the user. In addition, the pin-up notes infrastructure is not hard coded in any of the applications 101 , 140 , 150 , and thus may be used with any existing applications.
[0023] In another embodiment of the invention the pin-up notes infrastructure 120 enables the user to edit or delete previously generated pin-up notes. The user may select a UI screen, a data object or an object instance and the pin-up notes infrastructure 120 retrieves all pin-up notes mapped to the corresponding ID. The user may then edit the pin-up note and save it back. The user may also search for pin-up notes directly in the pin-up notes storage, and retrieve and edit the pin-up notes.
[0024] FIG. 2 illustrates an exemplary implementation of the system illustrated in FIG. 1 . The container application 101 is a host for application 140 . The GUI 141 of application 140 is linked to the container application GUI 102 and the user may see the GUI 141 as a screen in GUI 102 . The user is thus able to work on GUI 141 to access application 140 and its associated objects 161 and 162 . The user is now able to retrieve and manage pinup notes mapped to the UI screen 141 , data objects 161 and 162 and instances of these data objects using the pin-up notes infrastructure 120 .
[0025] FIG. 3 is a flow diagram illustrating a high level process flow 300 for pin-up notes retrieval and generation according to a preferred embodiment of the invention. In process block 302 a UI screen of an application is retrieved on user request and displayed on the GUI 102 of the container application 101 . In process block 304 the pin-up notes infrastructure retrieves the UI screen ID for the UI screen opened in process block 302 . At 306 , the pin-up notes infrastructure 120 checks whether there are any pin-up notes mapped to the UI screen ID. If there are any pin-up notes mapped to the UI screen ID, then the process continues to process block 326 wherein all the pin-up notes and the associated data mapped to the UI screen ID are retrieved and displayed to the user. Returning to decision block 306 , if there are no pin-up notes associated with the UI screen ID, the process proceeds to decision block 308 . In decision block 308 , if the user makes a request for unstructured data entry (e.g., pin-up note entry), the process continues to process 350 wherein the user generates one or more pin-up notes and maps the pin-up nodes to a UI screen, data object or an object instance. The pin-up notes are stored in the pin-up notes storage 131 . The process then continues to decision block 310 . Returning to decision block 308 , if there is no user request for pin-up notes entry, the process proceeds to decision block 310 . In decision block 310 , if the user does not request a data object selection, the process 300 is terminated. If the user does request a data object selection in decision block 310 , the process continues to process block 312 where the pin-up notes infrastructure 120 retrieves the data object ID of the selected data object. At 314 , the pin-up notes infrastructure 120 checks whether there are any pin-up notes mapped to the data object ID. If there are any pin-up notes mapped to the data object ID, then the process continues to process block 328 where all the pin-up notes and the associated data mapped to the data object ID are retrieved and displayed to the user. Returning to decision block 314 , if there are no pin-up notes associated with the data object ID, the process proceeds to decision block 316 . In decision block 316 , if the user requests for an unstructured data entry (e.g., pin-up note entry), the process continues to process 350 wherein the user generates one or more pin-up notes and maps them to a UI screen, data object or an object instance. The pin-up notes are then stored in the pin-up notes storage 131 . The process then continues to decision block 318 . Returning to decision block 316 , if there is no user request for pin-up notes entry, the process proceeds to decision block 318 . In decision block 318 , if the user does not request a data object instance selection, the process 300 is terminated. If the user does make a request for a data object instance selection in decision block 318 , the process continues to process block 320 where the pin-up notes infrastructure 120 retrieves the data object instance ID of the selected data object instance. At 322 , the pin-up notes infrastructure again checks whether there are any pin-up notes associated with the object instance ID. If there are any pin-up notes associated with the object instance ID, the process continues to process block 330 where the pin-up notes mapped to the data object ID are retrieved and displayed to the user. If there are no pin-up notes associated with the data object ID, then the process continues to decision block 324 . In decision block 324 , if the user requests a new pin-up notes entry, the process continues to process 350 wherein the user creates, maps and stores the new pin-up notes. The process is then terminated. Returning to decision block 324 , if the user does not request for any pin-up notes entry, the process 300 is terminated.
[0026] FIG. 4 illustrates a flow diagram of a process 350 for generating, mapping and storing pin-up notes. A new pin-up note is generated in process block 351 to record unstructured data (e.g., text, audio, video, etc). In process block 352 the user selects a UI screen, a data object or a data object instance for association with the pin-up note generated in process block 351 . In process block 353 , the pin-up notes infrastructure retrieves the ID for the selected UI screen, data object or data object instance from process block 352 . The process 350 then continues to process block 354 where the pin-up note generated in process block 351 is mapped to the ID retrieved in process block 353 by the pin-up notes infrastructure 120 . In decision block 356 , if the user requests another pin-up notes entry, the process returns to process block 351 . If the user does not make a request for another pin-up notes entry then the process 350 continues to the next decision block in process 300 or is terminated (refer to FIG. 3 ).
[0027] FIG. 5 illustrates a flow diagram of a process 500 for retrieval of pin-up notes mapped to an ID. In Process block 502 , the pin-up notes infrastructure 120 searches the pin-up notes storage 131 for pin-up notes mapped to an ID. The results of the search are retrieved in process-block 504 and the pin-up note along with the associated data are displayed to the user through GUI 102 or application GUIs 141 , 151 , etc.
[0028] In one of the embodiments of the invention the user is provided with an action button on the GUI 102 to launch a separate application for generation and management of pinup notes. According to another embodiment of the invention the user is provided with one or more action buttons, each action button enabling the user to map pin-up notes to a different type of ID. For example the user may be provided with three action buttons AB 1 , AB 2 and AB 3 . AB 1 may enable a user to generate pin-up notes and map them to a UI screen ID. AB 2 may enable the user to generate and map pin-up notes to an object type ID and AB 3 may enable the user to generate and map pin-up notes to an object instance ID. Thus, by clicking an action button the user may first generate a pin-up note and then select a UI screen data object or object instance to which the pin-up note will be mapped. In another embodiment of the invention, the user may create a pin-up note and map it to a currently active or a selected object or object instance by selecting an attach menu option or by clicking an action button, or through any other designated UI element.
[0029] In an embodiment of the invention, at any point of time the user is provided with three separate action buttons to access and view the pin-up notes retrieved from the pin-up notes storage 131 , each action button enabling the user to view pin-up notes associated to a different type of ID such as a UI screen ID, a data object ID or a data object instance ID. Thus, a user at any point of time may select an action button to view the pin-up notes associated to an ID type allocated to that action button.
[0030] In one embodiment, the pinup notes associated with a particular data object are automatically displayed in response to the user accessing the data object. For example, if the user views a structured data field to which a pin-up note is associated, the pin-up note will automatically be displayed for the user without the need for manual selection by the user (or played back in the case of audio or video pinup notes).
[0031] In another embodiment of the all the retrieved pin-up notes are presented to the user in a tabular format, with each pin-up note being displayed as a separate record entry along with its ID type. The user may then select each pin-up note to view it.
[0032] In one of the embodiment of the invention, the pin-up notes are assigned one or more attributes for identifying the users and/or computer systems associated with the pinup notes. The three particular attributes described below are referred to as “local and private,” “private” and “global.” Taking an example of a computer network having a number of client devices allocated to users, the pin-up notes having the “local and private” attribute are stored locally in the client devices of the users who have generated the notes. No other user in the network is allowed to access and view these pin-up notes. The pin-up notes having a “private” attribute are stored in a central server and are only made accessible to the user who generated the pin-up notes. In one embodiment, the user may access these notes from any client device in the network. The pin-up notes having a “global” attribute are stored in a central server and may be accessed and viewed by any user in the network from any client device. In one embodiment of the invention, the administrator of the computer network may be given rights to access and view the pin-up notes having any attribute, including the private attribute.
[0033] FIG. 6 illustrates an exemplary block diagram of a system 600 useful for implementing the invention according to a preferred embodiment of the invention. The system comprises a processor 610 that controls the entire system 600 . The processor 610 is coupled to a memory 620 which is used to store data temporarily during processing. The pin-up notes module 630 includes a pin-up notes generator 631 , a pin-up notes mapper 632 , a pin-up notes retriever 633 and an ID retriever. The pin-up notes generator 631 is configured to generate user requested pin up notes and store them temporarily in the memory 620 . The ID retriever 634 is configured to retrieve UI screen IDs, data object IDs and object instance IDs from applications (either container application 101 or applications 140 , 150 , etc) and store them temporarily in the memory 620 . The pin-up notes retriever 633 is configured to retrieve pin-up notes mapped to an ID. As soon as a user selects a UI screen, a data object or an object instance, the processor 610 instructs the pin-up notes retriever to retriever all pin-up notes associated with the selected ID type. The pin-up notes infrastructure then picks up the requested ID retrieved and stored temporarily by the ID retriever 634 in the memory 620 and searches in the pin-up notes database (not shown) for the pin-up notes associated with the ID. The pin-up notes retriever 633 then retrieves and stores the pin-up notes associated with the ID in the memory 620 . The user may access the memory 620 and view the retrieved pin-up notes any time. The pin-up notes mapper 632 is configured to map the pin-up notes generated by the user to an ID. As soon as the user selects a UI screen, data object or a data object instance, the processor 610 instructs the ID retriever 634 to retrieve the ID of the selected type and store it in the memory 620 . The pin-up notes mapper then maps the generated pin-up note which is already stored in the memory 620 by the pin-up notes generator 631 to the ID. The pin-up note along with its associated ID is then stored in the pin-up notes data base (not shown). The UI module 660 is configured to control the user interface through which the user interacts with the system. The UI module 660 is responsible to control and manage both the GUI 102 of the container application 101 and GUIs 141 , 151 of the applications 140 and 150 . The application container 640 stores the container application 101 . The application container 640 accesses applications from application servers 650 .
[0034] FIG. 7 illustrates a format in which the pin-up notes data is stored in the database according to a preferred embodiment of the invention. The pin-up notes data is stored in a tabular format 700 . The table 700 comprises of three major columns, 702 storing association type, 704 storing the associated ID and 706 storing the physical pin-up note. Each pin-up note along with its association type and associated ID is stored as a separate record 710 .
[0035] The particular methods associated with embodiments of the invention are described herein in terms of computer software and hardware with reference to flowcharts. The methods to be performed by a computing device (e.g., an application server) may constitute state machines or computer programs made up of computer-executable instructions. The computer-executable instructions may be written in a computer programming language or may be embodied in firmware logic. If written in a programming language conforming to a recognized standard, such instructions can be executed on a variety of hardware platforms and for interface to a variety of operating systems. In addition, embodiments of the invention are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein. Furthermore, it is common in the art to speak of software, in one form or another (e.g., program, procedure, process, application, etc.), as taking an action or causing a result. Such expressions are merely a shorthand way of saying that execution of the software by a computing device causes the device to perform an action or produce a result.
[0036] Elements of the invention may also be provided as a machine-readable medium for storing the machine-executable instructions. The machine-readable medium may include, but is not limited to, flash memory, optical disks, CD-ROMs, DVD ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, propagation media or other type of machine-readable media suitable for storing electronic instructions. For example, the invention may be downloaded as a computer program which 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). | A method and system for managing pin-up notes, wherein a data identifier ID is provided for a set of data. The pin-up notes mapped to the retrieved data identifier are retrieved responsive to providing the data identifier. A pin-up note is generated by a user and mapped to the retrieved data identifier. | 6 |
TECHNICAL FIELD OF INVENTION
[0001] The present invention relates to a positioning system for service lines. Generally, the invention relates to a mechanism for the deployment, retraction, and transportation of fixed-length service lines such as electrical, pneumatic, hydraulic, and communication resources necessary to the operation of a drilling rig used for subterranean exploration. More particularly, the invention provides an extendable cable positioning system for use with drilling rigs where pad drilling will require relatively short distance movements of the drilling rig and it is desirable to leave the energy resource systems stationary.
BACKGROUND OF THE INVENTION
[0002] It is an increasingly common practice in the drilling industry to engage in pad site drilling, where the drilling rig is moved a short distance to drill a subsequent hole only a few feet away from the previous well. This practice maximizes revenues from individual leases and significantly reduces the cost associated with the downtime, disassembly, transport, and re-assembly of the drilling rig.
[0003] Drilling rigs require energy of various types to be delivered to the drill floor, including electrical, pneumatic, and hydraulic energy. These energy sources are provided by generators and pumps located in housings located on skids or trailers adjacent to the drilling rig, but remote to the drilling floor. Other resources necessary to the drilling operation include communication paths. The energy and communication sources are transmitted between the generating houses to the drill floor by means of service lines, including tubes, pipes, conduits, cables, and the like. The service lines are normally a fixed length. Therefore, when a drilling rig is relocated between pads sites, it is necessary to relocate the energy source as well.
[0004] The distance between the generating source and the drilling rig spanned by the service lines is an obstacle to drilling operations. In particular, it is preferred to have vehicular access across the path of the service lines, without driving over and potentially damaging or destroying the service lines.
[0005] Another obstacle is the great weight of the collective service lines when run the distance between the connection source and the drilling rig. The distance may be as long as 150 feet, and the several service cables that run that distance will weigh tens of thousands of pounds.
[0006] Thus, there remains a need for improvements for the creation of a safe and reliable system for protecting service lines during drilling rig relocations on pad sites that permits the resource generating systems to remain stationary as the drilling rig is relocated to individual well locations.
[0007] In summary, the preferred embodiments of the present invention provide a unique solution to the engineering constraints and environmental challenges of providing a durable mechanically actuated steering system.
SUMMARY OF THE INVENTION
[0008] The present invention provides a novel system and method for the deployment, retraction, and transportation of fixed-length service lines such as electrical, pneumatic, hydraulic, and communication resources necessary to the operation of a drilling rig used for subterranean exploration. More particularly, the invention provides an extendable cable positioning system for use with drilling rigs where pad drilling will require relatively short distance movements of the drilling rig and it is desirable to leave the energy resource systems stationary.
[0009] In one embodiment of the service line positioning system, a transportable skid is provided and has a substantially vertical skid post. Panels are provided with at least one panel having at least one end pivotally connected to another panel. At least one panel is pivotally connected to the skid post. Each panel is supportable of service lines extending between the panels. The connected panels are movable between a retracted position above the skid and a deployed position that extends at least one panel beyond the skid.
[0010] In another embodiment, extension of the panels between the retracted position and extended position occurs in a substantially horizontal plane. In another embodiment, a first panel extends in a first direction from the skid, and a second panel extends in a second direction from the skid that is different from the first direction.
[0011] In another embodiment, the skid is mountable above ground level, such as on top of a structure, so as to provide clearance beneath at least one deployed panel sufficient to provide vehicular passage beneath the deployed panel.
[0012] In another embodiment, a latching mechanism is provided to secure a panel in the retracted position above the skid for transportation.
[0013] In another embodiment, the skid post is located proximate to a first end of the skid. A latch post is located proximate to an opposite second end of the skid. A panel is pivotally connected to the skid post on one end and releasably connected to the latch post on its opposite end. In another embodiment, the latch post supports a portion of the weight of the releasably connected panel when it is connected.
[0014] In another embodiment, a rig post is located between the base box and side box of a drilling rig. One of the panels has one end pivotally connected to the rig post. In another embodiment, a rig post is located between the base box and side box of a drilling rig. A panel is pivotally connectable to the rig post when the panel is in a deployed position. In another embodiment, the rig post is removably connectable to the drilling rig.
[0015] In another embodiment, a source post is located proximate to a source connection of the service lines. A panel has one end connected to the source post.
[0016] In another embodiment, a source post is located proximate to a source connection of the service lines. A panel is connectable to the source post when the panel is in a deployed position.
[0017] In another embodiment, the source post is connected to a structure, such that the weight of the structure counterbalances a portion of the weight of the panels deployed between the skid and the drilling rig.
[0018] In another embodiment, the source post is connected proximate to the center of gravity to a structure, such that the weight of the structure counterbalances the weight of the panels deployed between the skid and the drilling rig.
[0019] In another embodiment, a source post, skid post, and rig post are positioned in substantially vertical and substantially parallel orientation with respect to each other. The skid post is connected to a panel. The source post and rig post are each connectable to a panel.
[0020] In another embodiment, a source post, skid post, and rig post are positioned in substantially vertical and substantially parallel orientation with respect to each other. A panel is connectable between the source post and the skid post. At least two panels are connectable between the skid post and rig post.
[0021] In another embodiment, three panels are extendable into a deployed end-to-end configuration that extends at a length of at least 100 feet.
[0022] In another embodiment, four panels are extendable into a deployed end-to-end configuration that extends at a length of at least 150 feet.
[0023] In another embodiment, a transportable skid is provided, having a plurality of panels pivotally interconnected and attached thereto. The panels are retractable to a transportable position above the skid and extendable into a deployed end-to-end configuration that extends at a length of at least 100 feet. The panels are configured to support a plurality of continuous service lines.
[0024] As will be understood by one of ordinary skill in the art, the system disclosed may be modified somewhat and the same advantageous result obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The objects and features of the invention will become more readily understood from the following detailed description and appended claims when read in conjunction with the accompanying drawings in which like numerals represent like elements.
[0026] The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.
[0027] FIG. 1 is an isometric view of the service line positioning system having features of the present invention, illustrated in the retracted position above the skid for positioning on a trailer for transportation.
[0028] FIG. 2 is an exploded isometric view of the service line positioning system having features of the present invention.
[0029] FIG. 3 is an isometric view of the service line positioning system, illustrated as connected between a drilling rig and a supply source and deployed over a nearby well bore.
[0030] FIG. 4 is an isometric view of the service line positioning system, illustrated as connected between a drilling rig and a supply source and deployed over a nearby well bore.
[0031] FIG. 5 is an isometric view of the service line positioning system, illustrated as connected between a drilling rig and a supply source and deployed over a well bore located at a further distance.
[0032] FIG. 6 is an isometric view of the service line positioning system, illustrated as connected between a drilling rig and a supply source and deployed over a well bore that is on the location, but remote to the skid.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
[0034] FIG. 1 is an isometric view of a service line positioning system (SLPS) 100 having features of the present invention. System 100 comprises a skid 102 that is mountable on a trailer for transportation between locations for drilling. A skid post 104 extends generally vertically upwards from skid 102 . A plurality of panels 150 is located on skid 102 . At least one of panels 150 is pivotally connected to skid post 104 . Service lines 200 are attached to panels 150 .
[0035] In FIG. 1 , panels 150 are illustrated in the retracted position above a skid 102 for positioning on a trailer (not shown) for transportation. In the embodiment illustrated, panels 150 are retractable in a folding relationship such that service lines 200 are exterior to the folded connections between panels.
[0036] Panels 150 are connected in end-to-end series arrangement. Skid post 104 may be located in between two panels 150 . Other posts or connecting devices may be located between other panels 150 . In the embodiment illustrated, panels 150 fold at connection points in a manner that locates service lines 200 exterior to the vertex of each folded connection between panels 150 .
[0037] A guide rail 106 may be provided around the perimeter of skid 102 . In a preferred embodiment, guide rail 106 provides a vertical support for panels 150 . Rails 106 may provide support for panels 150 when panels 150 are in the retracted position. Also, rails 106 may provide support for panels 150 when panels 150 are extended beyond the perimeter of skid 102 .
[0038] FIG. 2 is an exploded isometric view of service line positioning system 100 having features of the present invention. In the embodiment illustrated, system 100 has four panels 150 . Panels 150 are comprised of a first panel 110 , having a first end 112 and an opposite second end 114 ; a second panel 120 , having a first end 122 and an opposite second end 124 ; a third panel 130 , having a first end 132 and an opposite second end 134 ; and a fourth panel 140 , having a first end 142 and an opposite second end 144 .
[0039] Service lines 200 extend in a continuous length between first panel 110 , second panel 120 , third panel 130 , and fourth panel 140 . In this embodiment, the source of the service in service lines 200 is connected to service lines 200 at the first end 112 of first panel 110 . The far opposite end of service lines 200 is connected to a junction box at a drilling rig 40 (see FIG. 3 ).
[0040] As stated, panels 150 are connected in end-to-end series arrangement, although posts such as skid post 104 or other connective hardware may be located between the panel 150 connections. In this embodiment, second end 114 of first panel 110 is pivotally connected to skid post 104 . First end 122 of second post 120 is also pivotally connected to skid post 104 . First end 132 of third panel 130 is pivotally connected to second end 124 of second panel 120 . First end 142 of fourth panel 140 is pivotally connected to second end 134 of third panel 130 .
[0041] In another embodiment not illustrated, system 100 has three panels, being first panel 110 , second panel 120 , and third panel 130 . In another embodiment not illustrated, system 100 has only two panels, being second panel 120 , and third panel 130 .
[0042] A latch post 108 may be attached to skid 102 . Latch post 108 may provide vertical load support to one or more of panels 150 when panels 150 are in the retracted position for transportation. Latch post 108 provides a mechanism for ensuring one or more panels 150 are locked in place relative to skid 102 for transportation. A connecting strike 109 may be provided at the bottom of one or more panels 150 for engagement with latch post 108 . There may alternatively be more than one latch post 108 . It will be understood that strikes 109 and latch posts 108 are reversible in regards to their location.
[0043] FIG. 3 is an isometric view of service line positioning system 100 , illustrated as connected to drilling rig 40 . A rig post 190 is supported between a base box 44 and a side box 46 of drilling rig 40 . Rig post 190 must be sufficiently sturdy to support a portion of the weight of system 100 . Second end 144 of fourth panel 140 is pivotally connected to rig post 190 . Rig post 190 may be advantageously irremovably attached to rig 40 to facilitate transportation of drilling rig 40 .
[0044] Service lines 200 extend beyond second end 144 of fourth panel 140 for connection to a junction box, or for direct connection to the appropriate equipment receiving service line 200 , such as a top drive, drawworks, control panel, or other device (service line 200 extension and connections not illustrated).
[0045] FIG. 4 is an isometric view of service line positioning system 100 , illustrated as connected between drilling rig 40 and a supply source 210 (not shown), and deployed over a nearby well bore 12 of a lease 10 . For clarity, rig 40 is shown without a mast. As illustrated, lease 10 may have a plurality of well bores. In the embodiment illustrated, well bores 12 , 14 , 16 , 18 , 20 , 22 , 24 , 26 , 28 , 30 , 32 , and 34 are all present on lease 10 . The numbering of the well bores is not intended to reflect an order by which they must be drilled. This is common in conventional drilling, where it has proven more economical to drill multiple wells directionally from a single lease 10 .
[0046] In this practice, drilling rig 40 may be equipped with translation pods 42 for moving rig 40 without the need to disassemble rig 40 . The problem solved by the several embodiments of the present invention is the need to extend service lines 200 with the movement of drilling rig 40 , and to do so in an economic manner and, most preferably, without interfering with ground traffic.
[0047] As illustrated in FIG. 4 , skid 102 is elevated and mounted on a structure 60 . Structure 60 can be any structure capable of supporting the weight of system 100 . First panel 110 is deployed and extended outward from skid 102 . A source post 170 is located on a second structure 70 . Structure 70 can be any structure capable of supporting the weight of system 100 . As an example, and not by way of limitation, structure 70 can be a variable frequency drive house or “VFD.”
[0048] First end 112 of first panel 110 is connected to source post 170 . Service lines 200 extend beyond first end 112 of first panel 110 for connection to a junction box, or for direct connection to the supply system for the service line 200 , such as a generator, pump, compressor, or other source (service line 200 extension and connections not illustrated). As illustrated, elevation of skid 102 and supply post 170 permits a vehicle 300 to maneuver between structures 60 and 70 without interfering with service lines 200 .
[0049] Second panel 120 remains in the retracted position. First end 122 of second panel 120 is pivotally connected to skid post 104 . Second end 124 of second panel 120 is illustrated in latched position to prevent movement of second panel 120 when drilling rig 40 is positioned over nearby well bore 12 for drilling. In this position, second end 124 of second panel 120 may be supported by latch post 108 , or by guide rail 106 .
[0050] Third panel 130 is shown in the deployed position. Optionally, a pedestal 180 (not shown) may be used to help support the weight of third panel 130 and fourth panel 140 during initial connection of fourth panel 140 to drilling rig 40 . Alternatively, commonly present drilling rig equipment, such as a mast headache rack, may serve as pedestal 180 . Optionally, pedestal 180 may remain in place during drilling operations to add stability to system 100 .
[0051] FIG. 5 is an isometric view of service line positioning system 100 deployed over well bore 34 , which is located at a distance further away from skid 102 . In FIG. 5 , drilling rig 40 has been relocated over well bore 34 , such as by use of translation pods 42 . System 100 has permitted service lines 200 to remain connected, and thus provide continuous power for the relocation of drilling rig 40 , and to be ready for all drilling operations at well bore 34 .
[0052] During relocation of drilling rig 40 between well bore 12 and well bore 34 , it remains unnecessary to deploy second panel 120 . However, deployment is optional.
[0053] FIG. 6 is an isometric view of service line positioning system 100 deployed over well bore 22 , which is located at a distance far away from skid 102 . In FIG. 6 , drilling rig 40 has been relocated over well bore 22 , such as by use of translation pods 42 . System 100 has permitted service lines 200 to remain connected, and thus provide continuous power for the relocation of drilling rig 40 , and to be ready for all drilling operations at well bore 22 .
[0054] During relocation of drilling rig 40 between well bore 34 and well bore 22 , it is necessary to deploy second panel 120 . If used, latch post 108 is disengaged from strike 109 to allow second panel 120 to pivot freely about skid post 104 . As illustrated, system 100 is in near to full extension. During such lengthy extension, pedestal 180 may be located beneath third panel 130 for additional support. In another embodiment, pedestal 180 may be a wheeled device, such that it relocates independently when rig 40 is relocated.
[0055] In this embodiment, first panel 110 and second structure 70 act as a counterbalance to the weight of fully extended second panel 120 , third panel 130 , and fourth panel 140 . As such, it is preferable to locate source post 170 near to the center of gravity of second structure 70 . It is also preferable that second structure 70 weigh about 10,000 pounds or greater. It is also preferable to locate first panel 110 generally perpendicular to skid 102 .
[0056] As illustrated in FIGS. 3 , 5 , and 6 , panels 150 are deployed in a horizontal plane. As best seen in FIG. 6 , first panel 110 is deployed in a first direction from skid 102 , and second panel 120 is deployed in a second direction from skid 102 that is different from the first direction of first panel 110 .
[0057] In the embodiment illustrated in which four panels 150 are utilized, an extension of 150 feet or greater may be achieved. In an alternative embodiment in which three panels are utilized, an extension of 100 feet or greater may be achieved.
[0058] While the aspects of the present disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. But it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims. | The present invention relates to a positioning system for service lines. Generally, the invention relates to a mechanism for the deployment, retraction, and transportation of fixed-length service lines such as electrical, pneumatic, hydraulic, and communication resources necessary to the operation of a drilling rig used for subterranean exploration. More particularly, the invention provides an extendable cable positioning system for use with drilling rigs where pad drilling will require relatively short distance movements of the drilling rig, and it is desirable to leave the energy resource systems stationary. | 5 |
[0001] This application is a continuation of Ser. No. 10/486,844 filed Sep. 9, 2004 which is a National stage of PCT/US02/26027 filed Aug. 16, 2002, which is a non-provisional of provisional U.S. Application Ser. No. 60/312,400, filed Aug. 16, 2001.
FIELD OF THE INVENTION
[0002] The invention relates to the field of cancer. In particular it relates to the areas of diagnostics and lung cancer.
BACKGROUND OF THE INVENTION
[0003] Lung cancer is the leading cause of cancer death worldwide and NSCLC accounts for nearly 80% of the disease (1). Based on cell morphology, adenocarcinoma and squamous are the most common types of NSCLC (2). Although the clinical courses of these tumors are similar, adenocarcinomas are characterized by peripheral location in the lung and often have activating mutations in the K-ras oncogene (3, 4). In contrast, squamous cell carcinomas are usually centrally located and more frequently carry p53 gene mutations (5). Furthermore, the etiology of squamous cell carcinoma is closely associated with tobacco smoking while the cause of adenocarcinoma remains unclear (6, 7). Although many molecular changes associated with NSCLC have been reported (8, 9), the global gene expression pattern associated with these two most common types of lung cancer has not be described. Understanding gene expression patterns in these major tumor types will uncover novel markers for disease detection as well as potential targets for rational therapy of lung cancer.
[0004] Several technologies are currently being utilized for gene expression profiling in human cancer (10). SAGE (11) is an open system that rapidly identifies any expressed transcript in a tissue of interest, including transcripts that had not been identified. This highly quantitative method can accurately identify the degree of expression for each transcript. Comparing SAGE profiles between the tumor and the corresponding normal tissues can readily identify genes differentially expressed in the two populations. Using this method, novel transcripts and molecular pathways have been discovered (12-14). In contrast, cDNA arrays represent a closed system that analyze relative expression levels of previously known genes or transcripts (15, 16). Because many thousands of genes can be placed on a single membrane or slide for rapid screening, studies have recently demonstrated molecular profiles of several human cancers (17-20).
[0005] Hierarchical clustering is a systematic method widely used in cDNA array data analysis where the difference between the expression patterns of many genes is generally within a few fold (21). We reasoned that because SAGE is highly quantitative, hierarchical clustering might be used to organize gene expression data generated by SAGE from just a few tissue libraries. To test this, SAGE tags from two of each libraries derived from primary adenocarcinomas, primary squamous cell carcinomas, normal lung small airway epithelial cells (SAEC), or normal bronchial/tracheal epithelial (NHBE) cells, and a lung adenocarcinoma cell line were used. SAGE tags showing the highest abundance were subjected to clustering analysis. Although each library was derived from a different individual, normal and tumor samples clustered in two separate branches while tissues of different cell types clustered together. Furthermore, SAGE tags clustered into biologically meaningful groups revealing the important molecular characteristics of these two most common NSCLC subtypes.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention provides a method of identifying a lung cancer as squamous cell carcinoma. According to the method an amount of a gene product of a gene in a lung cancer sample is determined. The gene is selected from the group consisting of: glutathione peroxidase (GPX; NM — 002083), glutathione S-transferase M3 (GSTM3; NM — 000849), aldoketoreductase family 1, member B 10 (NM — 020299), peroxiredoxin 1 (PRDX1; NM — 002574), small proline-rich protein 3 (SPRR3; NM — 005416), and TNF receptor superfamily member 18 (TNFRSF18; NM004195). The amount of the gene product in the lung cancer sample is compared to the amount determined in a lung tissue sample which is non-pathological. An increased amount of the gene product in the lung cancer sample relative to the lung tissue sample which is non-pathological identifies the lung cancer as a squamous cell carcinoma.
[0007] The present invention provides a method of identifying a lung cancer as adenocarcinoma. According to the method an amount of a gene product of a small proline-rich protein 3 (SPRR3; NM — 005416) gene in a lung cancer sample is determined. The amount of the gene product in the lung cancer sample is compared to the amount determined in a lung tissue sample which is non-pathological. A decreased amount of the gene product in the lung cancer sample relative to the lung tissue sample which is non-pathological identifies the lung cancer as adenocarcinoma.
[0008] The invention thus provides the art with a molecular diagnostic to supplement or replace histological features and/or clinical behavior.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1A-FIG . 1 C show clustering and multidimensional scaling of the SAGE libraries. Only genes with total tag-counts of at least 10 are included. ( FIG. 1A ) Cluster of all nine SAGE libraries. Genes are aligned horizontally, libraries are shown vertically. Red, green and black colors indicate genes expressed at high, low, or moderate levels, respectively, in the indicated library. ( FIG. 1B ) Dendrogram of clustered libraries. ( FIG. 1 C) Multidimensional scaling indicating the relatedness of the nine libraries.
[0010] FIG. 2A-FIG . 2 C show clustering and multidimensional scaling of the 115 genes differentially expressed (p<0.001) in 9 SAGE libraries. ( FIG. 2A ) Cluster of the 115 genes (left panel) with 3 main clusters (right panels) consisting of genes overexpressed in squamous cell carcinoma (upper), overexpressed in adenocarcinoma (middle) and underexpressed in adenocarcinoma (lower panel), respectively. † Indicates that this tag corresponds to more than one gene of the same family. * Indicates that this tag corresponds to more than one distinct gene. ( FIG. 2B ) Dendrogram of 9 clustered libraries, using 115 differentially expressed genes. ( FIG. 2C ) Multidimensional scaling of the libraries, using 115 differentially expressed genes. Tubulin, beta polypeptide tag (SEQ ID NO:1), ribosomal protein L37 tag (SEQ ID NO:2), gastrointestinal glutathione peroxidase 2 tag (SEQ ID NO:3), transferrin receptor tag (p90, CD71) (SEQ ID NO:4), brain glutathione S-transferase M3 tag (SEQ ID NO:5), carboxylesterase 1 tag (SEQ ID NO:6), aldo-keto reductase family 1 member B 10 tag (SEQ ID NO:7), peroxiredoxin 1 tag (SEQ ID NO:8), interferon, alpha-inducible protein 27 tag (SEQ ID NO:9), major histocompatibility complex, class I, B tag (SEQ ID NO:10), surfactant, pulmonary-associated protein A2 tag (SEQ ID NO: 11), major histocompatibility complex, class II tag (SEQ ID NO:12), immunoglobulin heavy constant mu tag (SEQ ID NO:13), pronapsin A tag (SEQ ID NO:14), surfactant, pulmonary-associated protein B tag (SEQ ID NO: 15), CD74 antigen tag (SEQ ID NO: 16), immunoglobulin lambda locus tag (SEQ ID NO: 17), immunoglobulin heavy constant gamma 3 tag (SEQ ID NO: 18), immunoglobulin alpha 2 tag (SEQ ID NO:19), VPS28 protein tag (SEQ ID NO:20), beta-2-microglobulin tag (SEQ ID NO:21), mucin 1 tag (SEQ ID NO:22), WAF1/CIP1/P21 tag (SEQ ID NO:23), no match tag (SEQ ID NO:24), ribosomal protein L13a tag (SEQ ID NO:25), S100-type calcium binding protein A14 tag (SEQ ID NO:26), keratin 19 tag (SEQ ID NO:27), keratin 17 tag (SEQ ID NO:28), keratin 6A tag (SEQ ID NO:29), keratin 5 tag (SEQ ID NO:30), small proline-rich protein 1B tag (cornifin) (SEQ ID NO:31), keratin 14 tag (SEQ ID NO:32), 14-3-3 sigma tag (SEQ ID NO:33), S100 calcium-binding protein A2 tag (SEQ ID NO:34), keratin 16 tag (SEQ ID NO:35).
[0011] FIG. 3A-FIG . 3 B show a comparison of genes under-expressed in adenocarcinoma using Affymetrix GeneChips™ and SAGE libraries. ( FIG. 3 A) Histogram of normalized SAGE data shows the average relative expression levels of 7 genes that were underexpressed in adenocarcinoma (shown in the lower right panel in FIG. 2C ). ( FIG. 3 B) Histogram of GeneChip™ data shows the normalized average relative expression levels of the same genes as in FIG. 3A . When a GeneChip™ expression value was less than 1, it was set to 1 before normalization. Normalization was done in the same manner as for clustering analysis.
DETAILED DESCRIPTION OF THE INVENTION
[0012] It is a discovery of the present inventors that certain molecular markers can be used to distinguish between the two most common forms of lung cancer: adenocarcinoma and squamous cell carcinoma. By assessing the expression levels of certain genes in a sample tumor tissue relative to normal, non-pathological lung tissue, one can make a determination of which of these types the cancer represents.
[0013] Expression of any gene which has been found to be up-regulated or down-regulated in one or more cancer types can be measured. According to one preferred embodiment, a lung tissue can be diagnosed, prognosed, or treatment determined by ascertaining an expression pattern of one or more cancer markers. Such markers include, but are not limited to glutathione peroxidase (GPX;; NM — 002083), glutathione S-transferase M3 (GSTM3; NM — 000849), aldoketoreductase family 1, member B 10 (NM — 020299), peroxiredoxin 1 (PRDX1; NM — 002574), small proline-rich protein 3 (SPRR3; NM — 005416), and TNF receptor superfamily member 18 (TNFRSF18; NM004195). The amount of the gene product determined in a suspected cancer tissue is compared to the amount of the same gene product in a lung tissue sample which is non-pathological. An increased or decreased amount of the gene product in the lung cancer sample relative to the lung tissue sample which is non-pathological identifies the lung cancer by type. Using such markers, one can distinguish between squamous cell carcinoma and adenocarcinoma of the lung, for example.
[0014] Either mRNA or protein can be measured as a means of determining up- or down-regulation of a gene. Any technique known in the art for measuring such gene products can be used. Quantitative techniques are preferred, however semi-quantitative or qualitative techniques can also be used. Suitable techniques for measuring gene products include, but are not limited to SAGE analysis, DNA microarray analysis, Northern blot, Western blot, immunocytochemical analysis, and ELISA,
[0015] Control samples which can be used according to the present invention include any non-pathological sample of lung tissue. These can be isolated from the same individual as the suspected lung sample or from a different individual, whether related or not. Suitable cell types include lung small airway epithelial cells as well as bronchial/tracheal epithelial cells.
EXAMPLES
Example 1
Tumors and Cell Lines
[0016] Primary lung tumor tissues used for SAGE were obtained from Johns Hopkins Hospital following surgery for lung resection due to cancer, and as previously described (9). Histologically, the two squamous tumors were moderately differentiated squamous cell carcinomas while the two adenocarcinomas consisted of a well differentiated and a poorly differentiated tumor with a shared common feature of lymphoplasmacytic infiltrations in the adjacent alveolar septa. SAEC and NHBE cells were purchased from Clonetics/BioWhittaker, Inc. (Walkersville, Md.) and propagated following the manufacturer's instruction. We chose these two primary cell cultures as normal controls because they represented pure populations of lung epithelial cells from the small and large airways, respectively. Tumor RNA samples were either purchased from BioChain Inc. (Hayward, Calif.) or obtained in the same manner as samples used for SAGE (9). A549 cells were obtained as a gift from Dr. James Herman (Johns Hopkins Oncology Center).
Example 2
SAGE Libraries and SAGE Analysis
[0017] Total RNA samples were isolated by RNazol B (Tel-Test Inc., Friendswood, Tex.) according to the manufacturer's recommendations. Poly (A) + RNA was extracted using the Oligotex mRNA Mini Kit (Qiagen Inc., Valencia, Calif.) and the Dynabeads mRNA DIRECT Kit (Dynal A. S., Oslo, Norway). SAGE libraries were generated and the tags sequenced as described (11) (22). SAGE 300 software (URL address: http file type, www host server, domain name sagenet.org, directory sage_protocol, subdirectory htm, was used to identify tag sequences and to quantify the abundance of each tag. The gene identity and UniGene cluster assignment of each SAGE tag was obtained using the tag-to-gene ‘reliable’ map (updated Apr. 23, 2001) from URL address: http file type, www host server, domain name ncbi.nlm.nih.gov, directory pub, subdirectory SAGE, subsubdirectory map and the table of UniGene clusters (updated May 23, 2001), from URL address: http file type, www host server, domain namencbi.nlm.nih.gov, directory UniGene.
Example 3
Normalization and Hierarchical Clustering Analysis
[0018] The “Cluster 2.11” program (URL address: http file type, domain name rana.lbl.gov,) was used for normalization and clustering of the SAGE data. Briefly, the normalization included logarithmic transformation of the data, followed by 10 cycles of centering the data on the median by samples, then by genes, each time scaling the sum of the squares in each sample and each gene to 1. The non-centered Pearson correlation was used for distance calculations and the weighted-average linkage was used for clustering as described (21).
Example 4
Multidimensional Scaling of Normal Lung and Tumor Samples
[0019] A classical multidimensional scaling method was used to determine the relatedness of each library analyzed by SAGE (23). Each sample was used to generate a unique library. A table of normalized expression levels for each gene in every library was used as a dissimilarity matrix. Normalization was performed using the “Cluster 2.11” program, as described above. Multidimensional scaling allows for the calculation of coordinates of objects if the distances between objects are known. The distances between the samples were calculated as 1−C nm , where C nm was the correlation coefficient between libraries n and m. The distance matrix spans an N-dimensional space, where N is the number of libraries in the study. Principal Component Analysis (23) was used to best fit the libraries into a 3-dimensional realm for presentation purposes.
Example 5
Statistical Analysis
[0020] The p-chance analysis [available in the SAGE 300 software and described in (21) was used to select genes most differentially expressed between each tumor and its corresponding normal controls. P-chance uses the Monte-Carlo method (24) to calculate the relative probability of detecting an expression difference equal to, or greater than, the observed expression difference between two samples by chance alone. For each tumor type, one of the two tumor libraries was first compared with the two corresponding normal libraries to select genes with a p-chance value of <0.001. At this p-chance, the false positive rate for all selected genes was <0.015. We next selected only those genes with consistent expression patterns in both tumor libraries of the same cell type and combined them with genes selected from the other tumor type using the same method.
Example 6
Real-Time Quantitative PCR Analysis
[0021] Five genes identified by SAGE as highly expressed in either adenocarcinomas or squamous cell carcinoma were analyzed by Real-time reverse transcription (RT)-PCR using 14 RNA samples from lung tumors and controls (25). The Real-time RT-PCR probes and primers were designed using Primer Express software (PE Biosystems, Foster City, Calif.). Primer sequences and reaction conditions are described in the supplemental material. The relative expression of each gene was calculated as the ratio of the average gene expression levels for tumors of the same cell type compared to its corresponding normal.
Example 7
Gene Expression Analysis Using GeneChip™
[0022] GeneChip™ U95A probe arrays were obtained from Affymetrix Inc.(Santa Clara, Calif.). A total of 32 RNA samples were individually prepared, hybridized to the GeneChip™, and scanned by a Hewlett-Packard (HP) GeneArray™ scanner as recommended by the manufacturer. Six internal GeneChip™ standards, β-actin, 18S rRNA, 28S rRNA, glyceraldehyde-3-phosphate dehydrogenase, transferrin receptor, and the transcription factor ISGF-3, were used as controls to ensure the quality of all samples tested.
Example 8
SAGE of NSCLC
[0023] A total of nine independent SAGE libraries were generated from five different normal and tumor tissues. A total of 18,300 independent clones were sequenced to generate 374,643 tags that represented 66,501 distinct transcripts (Table 1). Of the 23,056 distinct tags that appeared more than once in all nine libraries combined, 18,595 tags had at least one match to a UniGene cluster, 4,907 tags had multiple matches, 4,319 tags had no match, and 142 tags matched to mitochondrial DNA or ribosomal RNA sequences. Accounting for 7% potential sequencing errors (21) in tags that appeared only once in all nine libraries, the total number of distinct transcript tags identified is about 59,000. Although this number exceeds the current estimate of 30,000 to 40,000 genes predicted in the human genome (26, 27), the discrepancy could be accounted for by alternatively spliced transcripts and polyadenylation usage sites, which can result in multiple SAGE tags for the same gene (28, 29). Alternatively, since our transcript analysis was done on a limited number of tissues, it is possible that the current gene estimates are low.
[0000]
TABLE 1
SAGE in NSCLC and normal lung bronchial epithelial cells.
Tissue Source
No. Clones
No. Tags
Normal Human Bronchial Epithelial Cells-1
3759
58,273
(NHBE-1)
Normal Human Bronchial Epithelial Cells-2
4046
59,885
(NHBE-2)
Normal Small Airway Epithelial Cells-1
838
21,318
(SAEC-1)
Normal Small Airway Epithelial Cells-2
1299
26,956
(SAEC-2)
Squamous Cell Carcinoma-A
2259
56,817
Squamous Cell Carcinoma-B
2186
51,901
Adenocarcinoma-A
799
21,714
Adenocarcinoma-B
928
24,018
Adenocarcinoma cell line A549
2186
53,752
Total Number
18,300
374,634
Summary:
No. unique libraries = 9
No. unique tags = 66,502
No. of unique tags that appear >1 = 23,056
No. matched to unique UniGene cluster = 18,652
Example 9
Hierarchical Clustering of Tumor and Normal Lung Tissues Based on SAGE
[0024] To identify genes that are differentially expressed between the tumors and the normal samples, as well as between the different tumor types, we examined the overall similarities of the libraries derived from each tissue using hierarchical clustering (22). Since expression differences for more commonly expressed genes are less likely to have been observed by chance, a collection of 3,921 SAGE tags appearing at least 10 times in all nine libraries was subjected to the clustering analysis. Although each sample was derived from a different individual and had a unique expression pattern ( FIG. 1A ), the normal tissues were more similar to each other and the tumor tissues were more alike as a group. Furthermore, the SAEC and NHBE samples each paired together under the normal branch, while the adenocarcinomas and the squamous cell tumors each clustered together under the tumor branch ( FIG. 1B ). The adenocarcinoma-derived A549 cell line branched with the NSCLC tumors and demonstrated its relatedness to the two adenocarcinomas in multi-dimensional scaling (23), which displays the spatial relationship of all nine samples with respect to one another ( FIG. 1C ).
[0025] Because gene expression levels were represented by a tag-count for each transcript detected in the SAGE libraries, we used the Monte-Carlo simulation (24) to quantify the significance of gene expression differences between the tumor libraries and the two corresponding normal epithelial cell controls. At a p<0.001, fifty-eight genes were selected when comparing the two adenocarcinomas to the two SAEC samples, and 71 genes were obtained by comparison of the squamous cell carcinomas to the NHBE cells. Because 14 genes were common to both of comparisons, we therefore identified 115 highly differentially expressed transcripts for both tumor types (Table 1, List of genes in Supplemental Material ). As expected, when subjected to hierarchical clustering, these 115 genes again separated the nine libraries into the exact same branching patterns (FIG. 2A) as with the nearly 4,000 genes described above. Once again, the A549 cell line branched with the tumor tissues and was located closest to the two adenocarcinomas by multi-dimensional scaling ( FIG. 2B ).
Example 10
Biologically Distinct Clusters of Genes in Different NSCLC Subtypes
[0026] The clustering of the 115 statistically significant genes revealed at least three distinct gene clusters that were highly characteristic of the tumor tissues analyzed ( FIG. 2C ). Genes most highly expressed in squamous carcinomas of the lung ( FIG. 2C , upper panel) were characterized by transcripts encoding proteins with detoxification and antioxidant properties. These genes include glutathione peroxidase 2 (GPX2), glutathione S-transferase M1 (GSTM1), carboxylesterase, aldo-keto reductase, and peroxiredoxin 1 (PRDX1). Their presence in squamous cell lung cancers most likely represented cellular response by the bronchial epithelium to environmental carcinogenic insults (30, 31). The clustering of these overexpressed genes highlight the notion that functional variation of these proteins in the population may contribute to lung cancer susceptibility in some patients. In addition, GSTM1 is a known susceptibility marker for lung and oral cavity cancer (32). It has also been associated with breast (33) and ovarian cancers (34). Interferon alpha-inducible protein 27 is also shown to be overexpressed in 50% of breast cancers (35).
[0027] In contrast, the cluster of genes overexpressed in lung adenocarcinoma ( FIG. 2C , middle panel) mostly encoded small airway-associated proteins and immunologically related proteins. The presence of surfactants A2 and B, pronapsin A, and mucin1 in the cluster reflects the origin of tumors derived from small airway epithelial cells, such as type 2 pneumocytes and Clara cells (36, 37). However, high expression of these genes also suggested that these proteins may participate in the tumorigenesis of lung adenocarcinomas. Indeed, mucin1 is also overexpressed in breast cancers and tyrosine phosphorylation of the CT domain of MUC 1 mucin leads to activation of a mitogen-activated protein kinase pathway through the Ras-MEK-ERK2 pathway (38, 39). Furthermore, the overexpression of immunoglobulin genes in adenocarcinomas examined may be explained by the extent of B-cell infiltration and the presence of antigen presenting cells (APC) in the adenocarcinomas used for SAGE analysis. However, clustering analyses of the SAGE tags revealed that different tumor types preferentially expressed a different set of cell surface markers. Squamous cell cancers appeared to overexpress MHC class I and CD71 proteins ( FIG. 2C upper panel), while adenocarcinomas had a relatively high expression of MHC class II and CD 74 antigens. This gene expression differences in tumors indicated that immuno-based cancer therapy might be augmented based on the expression of different tumor surface markers.
[0028] No unexpected, many of the genes underexpressed in the primary adenocarcinomas and the A549 adenocarcinoma cell line ( FIG. 2C , lower panel) were those that are associated with squamous differentiation. These proteins include S100 proteins, keratins, and the small proline-rich protein 1B (Cornifin). Interestingly, two p53-inducible genes, 14-3-3% (Stratifin) (40) and p21 waf1/CIP1 (41, 42), clustered with this group of genes, showing significantly reduced expression in adenocarcinomas. Both p21 waf1/CIP1 and 14-3-3% are highly induced in cells treated with ionizing radiation and other DNA damaging agents in a p53-dependent manner (43, 44). Induction of these genes by p53 leads to cell cycle arrest (45). The p53 gene is frequently mutated in squamous carcinomas of the lung, and it is thought that mutations in p53 may contribute to the inability of lung epithelial cells to repair carcinogen-induced damage (46). In contrast, p53 mutations are observed much less frequently in lung adenocarcinomas (5). The reduced expression of both p21 waf1/CIP1 and 14-3-3α gene transcripts in adenocarcinomas suggests that inactivation of genes in the p53-pathway play an important role in this lung tumor type as well. However, reduced expression of an mRNA may not always correlate with a reduction of the gene product. Further studies correlating the molecular status of p53 with the expression of the encoded proteins are needed to assess the involvement of p53 and its downstream genes in the development of lung adenocarcinoma.
Example 11
Other Genes Differentially Expressed in NSCLC
[0029] It is important to note that the 115 highly differentially expressed genes we have identified only represented a set of genes whose differential expression could distinguish the molecular characteristics of each cell type as well as the neoplastic condition in the lung. Clearly, additional genes with biological significance to NSCLC could also be identified depending on the statistical method and the level of significance chosen. For example, when all tags that showed consistent expression within the libraries of the same cell type were compared to identify genes differentially expressed with a 99% confidence level, a larger number of candidate genes were identified. Specifically, 827 tags showed statistically significant differential expression between the squamous cell carcinomas and the NHBEs, with 71 tags showing at least 10-fold overexpression. A similar comparison of the two adenocarcinoma tumor libraries and the SAECs identified 298 tags showing differential expression, with 20 tags overexpressed at least 10-fold in the tumors. Jointly, 45 tags were differentially expressed in both comparisons and these genes were either a part of or further extended the observations revealed by the 115 genes. For example, small proline rich protein 3 (SPRR3) was elevated in the squamous tumors but was virtually absent in the adenocarcinomas. SPRR3 is a member of the small proline rich family of proteins which includes SPRR1 (Cornifin), a gene previously identified as a marker for squamous cell carcinoma (47) and is within the same cluster for genes underexpressed in adenocarcinomas ( FIG. 2C lower panel). SPRR3 is a member of the proteins in the cornified cell envelope that help provide a protective barrier to the epidermal layer of cells (48). Reduced expression of this family of proteins in adenocarcinoma may contribute to the invasive properties of this cancer. Moreover, several members of the tumor necrosis factor (TNF) family of proteins and their receptors have demonstrated increased expression in various cancers including NSCLC (49). Our statistical analysis of the SAGE data revealed that expression of the TNF receptor superfamily member 18 gene was increased in squamous cell tumors in addition to the detoxification and antioxidation genes. TNF promotes T-cell mediated apoptosis (50) and elevated expression of genes in this pathway may provide a mechanism for anti-proliferation of the tumor cells.
Example 12
Quantitative PCR and GeneChip™ cDNA Oligoarray Analyses of Additional NSCLC Tumors
[0030] Because SAGE libraries were derived from only selected tumor tissues, it was essential to determine whether gene expression patterns derived from SAGE could be reproduced in larger panel lung tissues using independent assays. A total of 43 additional tumor and normal samples were examined using either quantitative real-time PCR or cDNA arrays methods. Five genes observed by SAGE as highly overexpressed in either squamous or adenocarcinomas of the lung (listed in FIG. 2C ) were examined by Real-time RT-PCR using 10 different NSCLC tumors and four normal controls. As shown in Table 2, Real-time RT-PCR indicated that the two squamous-tumor specific genes had consistently high expression ratios in this tumor type compared to its expression in adenocarcinomas. Similarly, the three adenocarcinoma-specific genes had consistently higher expression in this tumor type and much less in squamous cell cancers compared to the normal.
[0000]
TABLE 2
Real-time quantitative PCR analysis of SAGE-identified genes.
No. of SAGE tags in library*
Ave. RT-PCR †
Spec.
Tag
Accession
Description
N1
N2
S1
S2
Sq A
Sq B
Ad A
Ad B
Sq/N
Ad/S
Sq
GGTGGTGTCT
X53463
Glutathione peroxidase 2
4
2
0
1
58
41
0
0
11
2
(SEQ ID NO: 3)
(GPX2)
Sq
GCCCCCTTCC
AF241229
TNF receptor superfamily
0
1
0
0
11
8
0
0
38
5
(SEQ ID NO: 36)
member 18
Ad
GAAATAAAGC
Y14737
Ig heavy constant gamma
0
0
0
0
5
1
293
23
1
17
(SEQ ID NO: 18)
3
Ad
GTTCACATTA
AI248864
CD74 antigen
0
1
0
1
9
2
86
21
31
93
(SEQ ID NO: 16)
Ad
GGGCATCTCT
J00196
Major histocompatibility
0
0
0
0
1
1
51
19
275
1800
(SEQ ID NO: 12)
complex, class II
Expression of the listed genes was examined in 14 samples, including five squamous cell tumors, four adenocarcinomas, one tumor with adenosquamous morphology, two NHBE culturesand two SAEC cultures. The actual number of tag occurrences in the indicated SAGE library is provided. † The average expression of each gene was calculated for the four distinct cell types, and the ratio of differential expression is indicated.Ad - Adenocarcinoma, Sq = squamous cell carcinoma, N = MHBL, S = SAEC, Spec. = Tumor specificity based on SAGE.
[0031] In order to survey the overall reliability of the molecular clustering obtained from lung SAGE libraries, we used GeneChip™ cDNA oligoarray (15, 16) to survey 32 tumor and normal samples (including three samples used in Real-time PCR) for relative gene expression. Only 51 of 115 highly differentially expressed transcript tags were present in the 12,000 element GeneChip™ (U95A), and 20 of 35 genes from the three main clusters (shown in FIG. 2C ) were comparable by both SAGE and the cDNA array. The gene expression levels for these 20 genes were averaged among all tumors of the same cell type and compared to that of the corresponding normal samples. Nineteen of 20 genes displayed an expression pattern similar to those obtained by SAGE. The expression patterns for the cluster of genes down-regulated in adenocarcinomas are shown ( FIGS. 3A and 3B ). These results indicate that hierarchical clustering of the SAGE libraries can reveal gene clusters with strong biological significance and support the notion that the highly quantitative and reproducible nature of SAGE can result in highly precise tissue classification and reliable gene clustering, using only a few tissue samples. Furthermore, because SAGE method is independent of the knowledge of the gene sequence or the probe hybridization condition, it allows for an unbiased identification and quantification of gene expression patterns in the tissues of interest. The use of SAGE can offer the opportunity to identify novel genes and molecular markers
[0032] In summary, we have used SAGE and hierarchical clustering analysis to identify molecular profiles and clusters of genes specifically associated with two of the most common types of human lung cancer. Although biologically significant and highly reproducible, the gene expression profile described here may only represented the basic molecular features from which adenocarcinoma and squamous cell carcinoma of the lung can potentially be distinguished. Histological features and clinical behavior of the tumor may depend on less pronounced changes in expression levels for a variety of genes and pathways. Nevertheless, cumulating evidence suggests that gene expression patterns most likely determine the clinical behavior and therapeutic response of the cancer (19, 51). The list of highly differentially expressed genes that we described will likely provide new molecular targets for improved diagnosis, prognosis, and rational therapy. The analyses for the expression of these in a larger number of lung tumors with detailed clinical information and outcome will be help to accomplish this goal.
[0033] While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described techniques that fall within the spirit and scope of the invention as set forth in the appended claims.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for recovering ammonium from waste water using CO 2 acidified absorption water.
[0003] 2. Background of the Invention
[0004] Various flow schemes have been proposed to recover ammonium from waste water that is highly contaminated with ammonium and ammonia. These generally involve raising the pH of the waste water to 9.0 or above, stripping the ammonia and then capturing it in an acidic scrubbing solution such as sulfuric acid (most common), hydrochloric acid or nitric acid. Conventional stripping towers, steam strippers, vacuum strippers and membrane systems (hollow fibers) have all been used at commercial and/or pilot scale.
[0005] Conventional methods for removal of ammonia, COS, and HCN from syngas prior to its use generally involves scrubbing with aqueous solutions to remove these compounds from the syngas with subsequent discharge of the scrubbing solutions to wastewater treatment or via alternate disposal methods.
[0006] Modern processes for ammonia removal include the water wash process in which the syngas is scrubbed by water, which dissolves the ammonia. The resulting scrubbing solution is pumped to an ammonia still where steam is used to strip out the ammonia. The ammonia vapors from the still can be processed to form ammonium sulfate, condensed to form a strong ammonia solution, incinerated or catalytically converted to nitrogen and hydrogen which are then recycled back into the gasifier.
[0007] Another process for ammonia removal from coke oven gas is the PHOSAM process developed by US Steel. This process absorbs the ammonia from the gas stream using a solution of monoammonium phosphate. The process produces saleable anhydrous ammonia, but operates at temperatures on the order of 50 degrees Celsius and pressures up to 190 psig (approximately 13 atmospheres of pressure gauge) in the stripper column. There is a need for a more robust and cost effective method for the treatment of syngas, particularly when used for biological transformation to useful liquid products such as ethanol, acetic acid or butanol.
[0008] Well known biological treatment processes used in concert with water based scrubbers can meet the objectives of high removal of ammonia, COS and HCN from syngas. Biological treatment processes can operate at atmospheric pressure and low temperatures without the excessive cost of expensive chemicals and operate without the generation of hazardous and/or toxic wastes. Biological treatment processing of ammonium, COS, and HCN absorbed into water from gas streams has been done before. Ammonia is, in general, removed using a slightly acidic or neutral pH scrubbing solution and this spent solution is sent to an aerobic wastewater treatment system where the ammonia is oxidized to nitrate and the nitrate subsequently reduced to nitrogen gas via denitrification, generally using an added organic electron donor such as methanol.
[0009] As generally described above ammonia may be removed from a system using a strong mineral acid such as hydrochloric acid (HCl) or sulfuric acid (H 2 SO 4 ) to react with the alkaline ammonia, forming a solution containing an ammonium salt such as ammonium chloride (NH 4 Cl) or ammonium sulfate ((NH 4 ) 2 SO 4 ). As this method requires the input of a strong acid to the system, there is an added expense for the cost of the chemicals and also the increased design requirements of any vessels, piping, hoses, and other chemical handling equipment so that these components can withstand the acidic environment. The ammonium salt may be used or sold as a concentrated solution or may be processed and removed from the system.
[0010] Large amounts of ammonia containing materials can result from the utilization of biomass to produce biofuels. Biofuels production for use as liquid motor fuels or for blending with conventional gasoline or diesel motor fuels is increasing worldwide. Such biofuels include, for example, ethanol and n-butanol. One of the major drivers for biofuels is their derivation from renewable resources by fermentation and bioprocess technology. One available technology path to convert lignocellulosic biomass to ethanol is to convert lignocellulosic biomass to syngas (also known as synthesis gas, primarily a mix of CO, H 2 and CO 2 with other components such as CH 4 , N 2 , NH 3 , H 2 S and other trace gases) in a gasifier and then ferment this gas with anaerobic microorganisms to produce biofuels such as ethanol, propanol, n-butanol or chemicals such as acetic acid, propionic acid, butyric acid and the like. This technology path can convert all of the components to syngas with good efficiency (e.g., greater than 75%), and some strains of anaerobic microorganisms can convert syngas to ethanol, propanol, n-butanol or other chemicals with high (e.g., greater than 90% of theoretical) efficiency. Moreover, syngas can be made from many other carbonaceous feedstocks such as natural gas, reformed gas, peat, petroleum coke, coal, solid waste and land fill gas, making this a more universal technology path.
[0011] In the gasification of biomass, the preponderance of the nitrogen in the biomass is converted to ammonia. When the syngas is cooled and scrubbed to remove particulates and other contaminants, this ammonia is to a large degree, removed in the scrubber/condensate flow stream. Treatment of this mass of ammonium requires a considerable sized waste water treatment system. If a significant fraction of this ammonium can be recovered for use in the fermentation itself and/or for export off site, a large savings in the capital and operating cost of waste water treatment can be realized, as no additional nitrogen needs to be purchased for the syngas fermentation and there may the opportunity to market the remaining ammonium-nitrogen as a co-product.
SUMMARY OF THE INVENTION
[0012] In the process of the present invention, summarized in its simplest form, a condensate stream from cleaning and cooling syngas containing the ammonia/ammonium (mostly present as ammonium since the CO2 in the syngas neutralizes the alkalinity produced by dissociation of the ammonia absorbed into the water stream), is stripped using a suitable carrier gas, such as air, or using a vacuum In most cases, the pH in the selected contactor will need to be adjusted upwardly to obtain more in the ammonia form to achieve greater stripping efficiency. The ammonia rich carrier gas is then contacted with a liquid rich in dissolved CO 2 in a scrubber/absorber. The ammonia is absorbed into this scrubbing solution and converted to predominantly the dissolved ammonium form, provided the pH is maintained at least one log unit below the pKa of ammonia. The scrubbing solution is maintained at this pH by cycling the scrubbing solution and contacting it with the tail gas from the fermentation process that will have between a 45% to 75% mole fraction of CO 2 . Overall it is possible to generate solutions of scrubber water that, depending on the purge rate and recycle rate, has anywhere from approximately 0.8% ammonium to approximately 14% ammonium for tail gas CO 2 concentrations of 45% and 75% mole fraction. Chilling the scrubber water to lower temperatures and, therefore increasing CO 2 solubility, will improve the maximum ammonium concentration that can be achieved in this solution, as would increasing the pressure in the scrubbing system.
[0013] Essentially the proposed process is a green technology. The recovered ammonium can be used in the anaerobic syngas fermentation as the nitrogen source and/or for reuse/sale off-site, or in the case of co-location with a corn ethanol facility, use in the yeast based fermentation as the nitrogen source. Since the ammonium is buffered by bicarbonate and carbonates formed from the dissolved CO 2 , this solution can provide some of the alkalinity needed in the fermentation process itself. When mineral acids are used the alkalinity is not recovered.
[0014] The process of this invention is particularly beneficial when integrated with the production of liquid products from syngas. Of most interest in this invention are waste water streams from the treatment of syngas where the process of this invention was found to have unique benefits when incorporated into a syngas biofermentation process. In such fermentation arrangements there is a tail gas produced from fermentation, and any reject gas flows from CO 2 scrubbing and the like, that have a high mole fraction of CO 2 (generally 45% to 75% mole fraction). It is feasible to use dissolved CO 2 , a relatively weak acid, in place of the typical mineral acids that are used for recovery of ammonia. The dissolved CO 2 solution can be generated by contacting the scrubber liquid used to recover the ammonia with the tail gas from the fermentation system and then recycling this liquid to capture ammonia stripped from the waste water. As a result no mineral acid is required for capturing the ammonium. This eliminates the need for the expense of the mineral acid and the need to maintain such acid on-site.
[0015] The instant invention is compatible with most of the ammonia stripping apparatus used in such processes, such as conventional strippers, vacuum strippers and membrane strippers, as mentioned above. It has recently been proposed to use hollow fibers for stripping, indicating it may be possible to achieve reasonable stripping efficiency without pH adjustment.
[0016] For use in syngas fermentation and/or use in a co-located corn to ethanol plant, this ammonium solution is suitable for use therein as is. Sale of the ammonium off-site would likely require the solution to be concentrated using RO, electrodialysis, evaporation or other concentrating technology.
[0017] Accordingly in one embodiment this invention is a process for removing ammonia and or ammonium from an aqueous stream and recovering ammonium carbonate and ammonium bicarbonate. The process comprising the steps of adjusting the pH of a liquid solution comprising ammonium to convert ammonium in the solution to free ammonia and produce a converted solution and stripping ammonia from the converted solution in an ammonia stripping vessel to produce a gas phase ammonia stream. Contacting the ammonia stream with a scrubbing liquid comprising dissolved CO 2 in a scrubbing vessel produces ammonium bicarbonate and ammonium carbonate. The process withdraws an ammonium liquid comprising ammonium carbonate and ammonium bicarbonate from the scrubbing vessel and recovers a first portion of the ammonium liquid as an ammonium product stream and recovers a second portion of the ammonium liquid by contact with a CO 2 containing gas stream and a make-up liquid to produce the scrubbing liquid.
[0018] In a more detailed embodiment the invention is a process for recovering ammonium carbonate and ammonium bicarbonate from an ammonium containing solution generated in the treatment and fermentation of biomass derived syngas. The process includes the steps of generating a raw syngas stream by the gasification of biomass. The process then cools and scrubs the raw syngas stream in a scrubber/cooler to generate a scrubbed syngas stream and a condensate stream containing volatile compounds and ammonium. The scrubbed syngas stream enters a fermentation zone to produce a fermentation product, a tail gas stream comprising CO 2 , and a biosolids stream. The biosolids stream passes to a digester to decompose the biosolids and recover an ammonium containing solution from the digester. Removing volatile compounds from the condensate stream by stripping or other means such as adsorption generates a scrubbed condensate stream containing ammonium. At least a portion of the scrubbed condensate stream and the ammonium containing solution passes to an ammonia stripping vessel that maintains the pH in the ammonia stripping vessel at least one log unit below than the pKa of ammonia to maintain free ammonia in the ammonia stripping vessel. Stripping ammonia from the ammonia stripping vessel with a stripping gas stream produces an ammonia gas stream. Contacting the ammonia gas stream with an ammonia scrubbing liquid comprising dissolved CO 2 in a scrubbing vessel produces ammonium bicarbonate and ammonium carbonate that is withdrawn from the scrubbing vessel as an ammonium liquid comprising ammonium bicarbonate and ammonium carbonate. A first portion of the ammonium liquid is recovered as an ammonium product stream and at least a portion of the ammonium product stream returns to the fermentation zone. Contacting a second portion of the ammonium liquid with the tail gas stream and a make-up liquid in a gas contacting vessel produces the ammonia scrubbing liquid comprising dissolved CO 2 .
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a block diagram showing the process of the present invention in its simplest form and including stripping and recovery of ammonium from syngas scrubbing using a CO 2 rich gas stream to absorb ammonium stripped from an ammonium rich stream, such as a syngas scrubber stream, with pH adjusted to provide sufficient unionized ammonia to effectively strip ammonia in a conventional stripper system.
[0020] FIG. 2 is a block diagram of another embodiment of the present invention that shows use of a flash vacuum stripper in place of a conventional gas stripper. No gas stripping stream is required with this approach.
[0021] FIG. 3 is a block diagram of another embodiment of the present invention showing an integrated system where the ammonium rich stream is a combination of syngas stripper condensate and effluent from a digester for destruction of excess biosolids produced in fermentation and the CO 2 rich stream used to recover the ammonium is the CO 2 rich tail gas from said fermentation system.
DETAILED DESCRIPTION OF THE INVENTION
[0022] This invention may any be used to treat any aqueous stream that contains large amounts of ammonia or ammonium. Useful input streams for the practice of this invention will typically a have combined concentration of ammonia and ammonium of greater than 0.1 to 1.0 wt %. Substantial amounts of ammonium carbonate and ammonium bicarbonate may be present in the feed stream.
[0023] Stripping of the ammonia stream from the aqueous input stream ordinarily takes place in an ammonia stripping vessel. With adjustment of the pH, stripping of the input stream will yield the gas stream containing primarily ammonia and any other volatile compounds that are not removed by pretreatment of the input stream. To maintain large amounts of free ammonia, the stripping vessel is usually kept at least at the pKa and preferably up to one unit above the pKa of ammonia to convert ammonium in the solution and produce a high concentration of ammonia in the converted solution so that the mole fraction of ammonia in the converted solution exceeds the mole fraction of ammonium.
[0024] Ammonia may be recovered from the stripping vessel in any manner that brings gas phase ammonia into intimate contact with a scrubbing liquid containing dissolved CO 2 . The pH of the scrubbing liquid is typically adjusted to 8.0 or lower. The dissolved CO 2 is typically maintained at an equilibrium concentration in the scrubbing liquid with the CO 2 mole fraction in the tail gas. Higher concentrations of dissolved CO 2 may be obtained by chilling and/or pressurizing the scrubbing liquid to change the equilibrium concentration. The contacting of the scrubbing liquid may take place in a scrubbing vessel that provides a large volume for direct contacting and mixing of the streams.
[0025] Alternatively vacuum stripping may draw a gas phase ammonia stream out of the ammonia stripping vessel. An eductor device that uses the scrubbing liquid as the motive fluid may simultaneously draw the ammonia out of the stripping vessel while also in conjunction with the associated piping may act as a scrubbing vessel to promote intimate mixing of the ammonia gas and the scrubbing liquid. Those skilled in the art are aware of other methods to withdraw ammonia gas from the stripping vessel and mix the scrubbing liquid therewith. Such methods can use membrane systems with various pressure control and contactors that will act as scrubbing vessels for mixing the ammonia with the dissolved CO 2
[0026] The CO 2 of the scrubbing solution reacts with the ammonium to produce ammonium carbonate and ammonium bicarbonate in an ammonium liquid. A portion of the ammonium liquid can be used as a product stream. In the case of an integrated biofermentation process the ammonium liquid is part of the process flow that provides ammonium to the fermentation zone. Through the buffering of the carbonate and bicarbonate the ammonium can provide some of the alkalinity needed in the fermentation zone.
[0027] In another aspect of the invention, at least a portion of the ammonium rich solution is passed to a concentrator to form a concentrated ammonia product. Any known concentrating mechanism may be used. The concentrated ammonia product may then be sold as a raw material for other processes which require ammonia, sold for use as a fertilizer, or used in another process co-located at a facility which includes the process described in this disclosure.
[0028] Another portion of the ammonium liquid passes to a CO 2 absorption vessel where it is combined with a make-up water stream and contacted with a CO 2 containing gas stream to provide additional scrubbing liquid. The scrubbing solution will usually comprise water which is constantly replenished with make-up water to replace ammonium liquid withdrawn for product use. The CO 2 gas stream that contacts the scrubbing water and the ammonia liquid will usually have a CO 2 mole fraction that stream is greater than 40%.
[0029] Of most interest in this invention are waste water streams from the treatment of syngas where the process of this invention was found to have unique benefits when incorporated into a syngas biofermentation process. A variety of gasification processes are known for the production of syngas from various carbonaceous materials. The syngas is produced by gasifying biomass in a gasifier. “Biomass” as used in this application means organic solid material including municipal solid waste. Examples of material that would be considered biomass under this definition include, but are not limited to: corn, corn stalks, sugarcane, bagasse, wood, sawdust, paper, cardboard, cotton, cotton fiber, leaves, and municipal solid waste. Any process of gasifying the biomass to syngas may be used.
[0030] Once gasified, the biomass is converted to a syngas effluent stream comprising carbon monoxide, carbon dioxide, hydrogen, ammonia, and particulates. This syngas effluent stream is then scrubbed by contacting with a scrubber liquid, typically comprising water, to form a scrubbed gas stream and the scrubber condensate stream comprising ammonia and ammonium that serves as the previously described input stream. In addition, the syngas will often contain dissolved volatile compounds including hydrocarbons, COS and HCN. The syngas will typically undergo scrubbing for the removal of these compounds with the scrubber liquid. The scrubber liquid may undergo gas stripping, contact with activated carbon, or other treatment to remove HCN and volatile compounds before adjusting the pH of the syngas scrubber liquid. The scrubber may also serve as a cooler to reduce the temperature of the syngas stream. The scrubbed gas stream from the scrubber or scrubber/cooler is passed to the fermentation broth in a fermentation zone which comprises microorganisms to form liquid products and a carbon dioxide rich gas. Any suitable microorganisms may be used.
[0031] In some processes it is advantageous to keep the fermentation zone at a neutral or alkaline pH. An advantage of the present invention is that ammonia is more readily soluble in water than many calcium-containing alkaline materials, and thus ammonia and ammonium are easier to pass to the various components of the present invention. The recycling of at least a portion of the ammonium rich solution to the fermentation zone can also add sufficient nitrogen to provide the cellular maintenance and growth needs of the microorganisms.
[0032] The use of microorganisms for bioconversions of CO and H 2 /CO 2 to acetic acid, ethanol, and other products are well known. For example, in a recent book concise description of biochemical pathways and energetic of such bioconversions have been summarized by Das, A. and L. G. Ljungdahl, Electron Transport System in Acetogens and by Drake, H. L. and K. Kusel, Diverse Physiologic Potential of Acetogens , appearing respectively as Chapters 14 and 13 of Biochemistry and Physiology of Anaerobic Bacteria, L. G. Ljungdahl eds., Springer (2003). Any suitable microorganisms that have the ability to convert the syngas components CO, H 2 , CO 2 individually or in combination with each other or with other components that are typically present in syngas may be utilized. Suitable microorganisms and/or grown conditions may include those disclosed in U.S. patent application Ser. No. 11/441,392, filed May 25, 2006, entitled “Indirect Or Direct Fermentation of Biomass to Fuel Alcohol,” which discloses a biologically pure culture of the microorganism Clostridium carboxidivorans having all of the identifying characteristics of ATCC no. BAA-624; and U.S. patent application Ser. No. 11/514,385 filed Aug. 31, 2006 entitled “Isolation and Characterization of Novel Clostridial Species,” which discloses a biologically pure culture of the microorganism Clostridium ragsdalei having all of the identifying characteristics of ATCC No. BAA-622; both of which are incorporated herein by reference in their entirety. Clostridium carboxidivorans may be used, for example, to ferment syngas to ethanol and/or n-butanol. Clostridium ragsdalei may be used, for example, to ferment syngas to ethanol.
DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0033] Referring now to the drawings in greater detail, there is illustrated in FIG. 1 a block diagram of the process of the present invention in its simplest form. As shown, a stream 15 rich in ammonium, from a source, such as a syngas condensate stream, is combined with a caustic agent 12 , such as NaOH or other alkali, to adjust the pH upward such that most of the ammonia is present as unionized or free ammonia. This combined stream 17 is sent to stripping tower 30 , where it is contacted with a gas stripping stream 34 that is lean in ammonia concentration and recycled to the stripping tower 30 from an ammonia absorption vessel 50 . A scrubbed water stream 25 , that has a significantly reduced ammonium concentration, is discharged from stripping tower 30 and sent to waste water treatment while an ammonia rich gas stripping stream 35 , which results from stripping the ammonia from stream 25 , is sent to the ammonia scrubbing tower 50 for recovery or capture of the ammonia.
[0034] In the ammonia scrubbing tower 50 , gas stream 35 is contacted with a CO 2 rich ammonia absorption liquor stream 55 and a significant proportion of the ammonium is absorbed into the liquor from stream 35 . Tower 50 discharges an ammonia lean gas stream as gas stripping stream 34 back to the ammonia stripper tower 30 . The absorption liquor discharged from the scrubbing tower 50 via line 51 , now rich in dissolved ammonium bicarbonate and ammonium carbonate formed through a reaction between the ammonia and the CO 2 , is split with a first portion 95 discharged for use at the site or sale off site and a second portion 75 being sent back to a CO 2 absorption column 70 , where the concentration of dissolved CO 2 is replenished. Make-up water stream 85 is added to the CO 2 absorption column 70 in combination with the second portion 75 via a combined stream 83 to maintain the volume lost by purging of first portion 95 .
[0035] In the CO 2 absorption column 70 , a CO 2 rich gas stream 65 is contacted with combined stream 83 to replenish the concentration of dissolved CO 2 Combined stream 83 contains the combined flows of make-up water 85 and the second portion 75 of liquor from the ammonium scrubbing tower 50 . The CO 2 rich ammonia absorption liquor stream 55 is then provided to the scrubbing tower 50 using pump 62 . Exit gas 45 from the CO 2 absorption column 70 is treated as appropriate and then discharged to the atmosphere.
[0036] In FIG. 2 , instead of using an ammonia scrubbing tower 50 and a circulating scrubbing gas to carry the ammonia to an ammonium scrubbing tower as in FIG. 1 , the CO 2 rich ammonium absorption liquor stream 55 from CO 2 absorption column 70 runs through a venturi device 22 that pulls a vacuum to draw out ammonium rich overhead gas from a vacuum vessel 40 . Line 37 transfers the ammonia from the vacuum vessel 40 into the venturi device 22 where it contacts stream 55 . Absorption of the ammonia forms ammonium bicarbonate and ammonium carbonate taken by stream 36 and split into the second portion 75 for return to the CO 2 absorption column 70 and the first portion 95 recovered as product for use or sale offsite. Any non-condensable gases in line 37 are carried into the CO 2 absorption column 70 where they are released with the appropriately treated exit gas 45 . In the CO 2 absorption column 70 , the CO 2 rich gas stream 65 contacts the combined stream 83 , that contains make-up water 85 and returned ammonium bicarbonate and carbonate from second portion 75 to replenish the concentration of dissolved CO 2 . Pump 62 returns the CO 2 rich ammonia absorption liquor stream 55 to the venturi device 22 .
[0037] FIG. 3 shows the process of the instant invention integrated with the steps for the fermentation of syngas into soluble products such as ethanol, propanol, butanol or acetate, propionate or butyrate. Note that, although shown for a syngas based fermentation, this further embodiment of the process of the present invention is applicable for any fermentation system where a tail or off-gas rich in CO 2 is produced and the fermentation process utilizes a source of nitrogen.
[0038] FIG. 3 , incorporates the ammonia recovery arrangement depicted in FIG. 1 into its overall embodiment. In this case a combination of several streams that have high ammonium, a syngas scrubber stream carried by a line 14 and a waste water stream 16 , are sent to ammonia recovery.
[0039] In this arrangement a fermentation vessel 20 delivers excess biosolids 77 for digestion in digester 60 . Digester 60 may be an anaerobic digester or aerobic digester and may be equipped with a device 40 that manages excess biosolids 77 by grinding or other means that enhance degradation. Streams 99 and 99 ′ transfer biosolids to and from device 40 . Note that although shown as an internal recycle in FIG. 3 , using device 40 as a pretreatment or post treatment device is also possible. Digester 60 discharges the bulk of the total suspended solids (TSS) to a separation device 80 that produces a concentrated solids stream 44 and waste water stream 16 which is low in suspended solids and rich in nutrients including ammonia.
[0040] Line 11 introduces raw syngas into a direct contact scrubber/cooler 10 for condensing and cooling. Line 21 carries cleaned syngas to fermentation vessel 20 while a condensed scrubber water stream passes via line 19 to a stripper 88 .
[0041] In stripper 88 a stripping gas stream 33 removes dissolved hydrocarbons that exit as gas stream 29 . Gas stream 29 is managed to utilize the energy content of the stripped hydrocarbons in the gas. The remainder of the scrubber water, now high in ammonium leaves stripper 88 via line 14 .
[0042] A condensate stream 25 , formed by combining scrubber stream from line 14 with waste water stream 16 , has high ammonia content due to biological digestion of the excess biosolids 77 produced during fermentation. The condensate stream 25 , now pH adjusted by the addition of a caustic agent from line 12 , passes to passes ammonia stripping tower 30 . Note that stream 25 can be sent through pretreatment to remove suspended solids and/or dissolved, non-condensable gases prior to ammonia stripping if desired.
[0043] Condensate stream 25 passes to the stripping tower 30 for recovery of ammonia which passes to scrubbing tower 50 production and recovery of ammonium carbonate and ammonium bicarbonate as previously described. A portion of the ammonium bicarbonate and ammonium carbonate that leaves scrubbing tower 50 passes to the fermentor 20 via line 23 as nitrogen input.
[0044] Fermentation vessel 20 passes the cleaned syngas from line 21 into contact with anaerobic microorganisms. The microorganisms consume the syngas and as part of their metabolic processes and excrete liquid products, such as ethanol. Nitrogen in the form of ammonium from scrubber liquid from line 23 enters fermentor 20 through line 31 along with fresh fermentation media. Line 27 recovers ethanol produced by the fermentor 20 . A tail gas stream rich in CO 2 passes from fermenter 20 via line 65 to supply CO 2 to absorption column 70 .
[0045] For purposes of further description a 20 million gallon per year syngas to ethanol plant is used as a calculated example of the instant invention. The raw syngas stream is cooled and scrubbed resulting in a condensate stream that has approximately 630 pounds/day of ammonium as nitrogen. Approximately 1,620 pounds/day of ammonium as nitrogen is added to the syngas fed fermentors to provide the necessary nitrogen for good cell growth. The combined purge flows from the fermentation system contain 160 pounds/day of ammonium as nitrogen and 1,460 pounds/day of organic nitrogen, primarily cell biomass plus some soluble proteins formed during the fermentation process. The fermentation purge flows are forwarded to an anaerobic digestion (AD) system equipped with a device to shear the biomass and enhance the degradation of the excess biomass wasted from fermentation. The effluent stream from the anaerobic digestion process after the solids are removed via centrifugation, membrane filtration and/or other applicable unit operation contains approximately 1,330 pounds/day of ammonium as nitrogen and an additional 130 pounds/day of organic nitrogen. This results in a combined stream of scrubber condensate and AD centrate of 1,960 pounds/day of ammonium as nitrogen and 130 pounds of organic nitrogen that is sent to an ammonium stripping/recovery unit. The tail gas stream from the fermentation process provides a stream rich in CO 2 that passes to the absorption column of the stripping recovery unit to provide the ammonia scrubbing liquid. The stripping system recovers 85% of the ammonium as ammonium bicarbonate and ammonium carbonate or 1,670 pounds/day. Of this, 1,620 pound/day of the ammonium is recycled back to the fermentation process. The remainder of the ammonium is available for sale off-site as a fertilizer product, disposed of off-site or simply wasted along with the remaining ammonium and organic nitrogen in the stripper bottoms to the wastewater treatment plant.
[0046] As described, the present invention provides a number of advantages, some of which have been described above and others which are inherent in the invention. Also, modifications may be proposed without departing from the teachings herein. Accordingly, the scope of the invention is only to be limited as necessitated by the accompanying claims. | The processes are utilized to recover ammonium from waste water using CO 2 acidified absorption water. The process is particularly suited for utilization of cellular matter and a CO 2 rich tail gas from a syngas fermentation process and derives significant benefit from the recovery of ammonium bicarbonate and ammonium carbonate. Ammonia and ammonium are recovered from the treatment of the syngas as an ammonium rich solution, at least a portion of which is recycled to the fermentation zone to aid in the production of liquid products. A carbon dioxide rich gas produced by fermentation is used to capture the ammonia and ammonium, forming the ammonium rich solution. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of International Application No. PCT/EP2003/010179, filed on Sep. 12, 2003, which claims priority to German Application No. 102 42 419.5, filed on Sep. 12, 2002, the contents of both applications are incorporated in their entirety herein.
FIELD
[0002] The present invention relates to medical devices, including medical devices for transporting, transmitting, administering, extracting or delivering medicinal or other substances to and from other medical devices or patients. It also relates to methods of making and using such devices. More particularly, the present invention related to catheters and catheter heads, including a catheter head for introducing a fluid into an organic tissue, in particular a catheter head for administering a liquid active agent.
BACKGROUND
[0003] Catheter heads, including those of the type mentioned above, are, for example, used in conjunction with infusion means in order to enable a part of the catheter head—i.e., the cannula casing together with a cannula inserted in a body—to be changed or a fluid to be exchanged. This useful for a patient to whom a fluid is permanently or repeatedly administered. To this end, another part of the catheter head—the connecting element to a fluid supply—is detached from the cannula casing and, once the cannula casing has been exchanged, can be placed onto the new cannula casing attached to the body in order to continue introducing the fluid. At the same time, a new fluid container can easily be connected to the connecting element. It is also possible to place another, homogeneous connecting element of a new fluid container onto the cannula casing, such that the fluid can continue to be administered. Such a catheter head can however also be used for example to remove analysis liquid from a patient's body or to introduce the analysis liquid into the body and remove it again.
[0004] In general, the cannula casing of the catheter head comprises a cannula which protrudes from one side of the cannula casing and a passage channel running through the cannula casing and connected to the cannula. The connecting element of the catheter head has a fluid supply and is connected to the cannula casing in such a way that the fluid supply is connected to the passage channel. Furthermore, a guiding means is provided which, when the cannula casing is combined with the connecting element, guides the connecting element into the correct position onto the cannula casing. The connecting element is firmly fixed on the cannula casing by a fixing means, but can be detached again.
[0005] Such a catheter head is, for example, described in DE 299 05 068 for a subcutaneous infusion means. In this catheter head, the connecting element is plugged into the cannula casing, such that the fluid supply is arranged as an extension of the cannula. The guiding means and the fixing means is then axially symmetrical with respect to the longitudinal axis of the fluid supply. A first part of the guiding means is provided in the cannula casing as a hollow space having a circular inner wall. A second part of the guiding means is provided by an outer wall of the connecting element which during combining abuts the inner wall of the hollow space in the cannula casing. Once the cannula casing has been combined with the connecting element, the connecting element is therefore rotatably arranged in the cannula casing. A blocking mechanism is provided which fixes the connecting element in a certain angular position with respect to the casing. In each of these angular positions, however, the fluid supply forms the extension of the cannula. Different angular positions between the cannula and the fluid supply are not formed. Such a blocking mechanism is provided, for example, by a flexible sealing arm provided on the connecting element together with an exterior protrusion. Once the connecting element has been inserted into the cannula casing, the protrusion engages with a circular groove in the interior of the cannula casing and in this way fixes the connecting element to the cannula casing. In order to release the block, the flexible sealing arm is bent inwards and the connecting element can be removed from the cannula casing.
[0006] A catheter head can comprise a plate-shaped cannula casing with a cannula protruding downwards, as is known from U.S. Pat. No. 6,017,328. A connecting element, also plate-shaped, is placed onto the cannula casing in such a way that the fluid supply is arranged substantially perpendicular to the axis of the cannula. The fixing element comprises two laterally running arms which can be pressed together towards the center of the fixing element. At their ends, the arms comprise protrusions directed towards the cannula casing, via which they firmly engage with corresponding cavities on the cannula casing. The engagement can be released again by pressing the arms together. The angular position of the connecting element with respect to the cannula casing is defined by the predetermined position of the cavities on the cannula casing. The direction in which the fluid supply leads away from the cannula casing is therefore predetermined.
[0007] In the catheter heads as set forth in the prior art, it is either not possible to select an angular setting between the cannula casing or cannula and the fluid supply, or a particular angular position is pre-set and not variable. If, therefore, it is desired for the fluid to be supplied from another direction, one exemplary solution is to select a supply tube having a sufficiently large length, which can be bent to the desired other direction without disrupting the flow, or, in the case of a cannula remaining in the patient, the entire catheter head has to be rotated, which is unpleasant and unacceptable for the patient.
SUMMARY
[0008] An object of the present invention is to provide a catheter head that can be used for introducing a fluid into an organic tissue, in which a cannula casing and a connecting element can be connected to each other in a simple way and in which a variable fluid supply to the tissue is enabled.
[0009] In one embodiment, the preceding object is addressed by providing a catheter head comprising a cannula housing with a cannula, a connector element with a fluid inlet, a guide and a fixing device. The guide device has several selectable discrete rotational positions for positioning the connector element relative to the cannula housing about a longitudinal axis of the cannula. The connector element, positioned in a rotational position, is detachably connected to the cannula housing in the selected position by means of the fixing device. In general, the catheter head in accordance with the present invention may be used to introduce a fluid, for example, a medicinal fluid, into an organic tissue, but it may be used for other purposes as well.
[0010] In one embodiment, a catheter head of the type described above, for positioning the connecting element relative to the cannula casing, comprises a number of selectable, discrete rotational positions about a longitudinal axis of the cannula. The connecting element, positioned in a rotational position, is detachably fixed to the cannula casing in the selected rotational position by the fixing means. In the case of a catheter head, it is also possible to detach the fixing means, select another positioning of the connecting element relative to the cannula casing, and fix the connecting element to the cannula casing again in this rotational position, without completely separating the connecting element from the cannula casing. When fixing the connecting element to the cannula casing, the fluid supply is preferably arranged at an angle to the longitudinal axis of the cannula. Using the catheter head in accordance with the invention, it is possible to provide a fluid supply from different directions, when introducing or administering a fluid into an organic tissue. This extends a patient's freedom of movement and can ensure that the fluid is optimally introduced.
[0011] In a preferred embodiment of a catheter head in accordance with the invention, the cannula casing is formed to be substantially flat or plate-like. The casing is preferably circular in a top view. The cannula protrudes substantially perpendicular from the planar, for example, the level side facing the tissue. However, it is also conceivable to arrange the cannula at an angle to the perpendicular of the cannula casing. The cannula is preferably provided in the center of the cannula casing on this side, but can also be arranged on the edge of the cannula casing. The connecting element, also planar and preferably circular, is arranged on the opposite planar side facing away from the tissue. Once the connecting element has been fixed to the cannula casing, the fluid supply is then preferably arranged substantially perpendicular to the axis of symmetry of the cannula casing, i.e., the fluid to be introduced is diverted by about 90 degrees inside the catheter head. Depending on the requirements for introducing a fluid, however, a different angular position can also be fulfilled, or the fluid supply can be arranged in the extension of the cannula. It is then advantageous if the individual rotational positions of the guiding means can be freely selected, the fluid can then be supplied into the catheter head from any direction, adjusted to the specific requirements. When the cannula casing and the connecting element are combined, the liquid connection can, for example, be formed by a needle at the end of the fluid supply of the connecting element, which is inserted into the passage channel of the cannula casing. It is, however, also possible to provide a joint transition region in the design of the catheter head, into which both the fluid supply of the connecting element and the passage channel of the cannula casing feed.
[0012] In some preferred embodiments, a locking connection is provided for forming the various selectable discrete rotational positions between the cannula casing and the connecting element, wherein the individual locking settings correspond to the discrete rotational positions. Two locking means, adjusted to and/or complementary to each other, can, for example, be provided for this purpose. A first locking means is arranged at least on a partial region of an annular area of the cannula casing. A second locking means is arranged at least on a partial region of an annular area of the connecting element and is directed against the first locking means. The partial regions of an annular area thus correspond to a sector area along the circumference about the center, i.e., the center-point of the circular cannula casing or connecting element, respectively, whereby the locking means are formed on annular sector areas. The annular sector area of the first locking means on the cannula casing and the annular sector area of the second locking means on the connecting element face each other, such that the locking means can cooperate when the catheter head is combined. The annular sector areas of the locking means can then be arranged both in a region near the center, in a region away from the center, and on an outer circumference of the cannula casing or connecting element, respectively. Care merely has to be taken that the arrangements of the annular sector areas on the cannula casing and on the connecting element are adjusted to each other. When placing the cannula casing and the connecting element onto each other, these two parts can be rotated about the center against each other, until they have a desired rotational position with respect to each other. By further joining the two parts together, the connecting element is guided in this selected position along the corresponding locking setting onto the cannula casing. Accordingly, a number of selectable discrete rotational positions of the connecting element relative to the cannula casing are provided by the different locking positions of the connecting element.
[0013] In one preferred embodiment, the first and second locking means are each formed by protrusions, e.g., ribs. In some embodiments, it is possible for one of the two locking means to be formed by a number of protrusions and the other locking means to be formed by one protrusion only. In one preferred embodiment, both locking means comprise a number of protrusions. The protrusions are at least partially directed towards the center of the cannula casing or connecting element, respectively, and in particular are arranged radially orientated towards the center. When the connecting element is positioned on the cannula casing, the second protrusions of the connecting element interlock between the first protrusions of the cannula casing. The areas of the protrusions protruding from the annular sector region can be arranged obliquely with respect to the base area formed by this region, in order to enable the first and second protrusions to slide gently into each other. In this embodiment, the first and second locking means move substantially directly towards each other. It is, however, also possible to provide the first locking means on an outer circumferential area of the cannula casing, using protrusions which protrude radially outwards from the cannula casing. To this end, teeth could, for example, be provided on the edge of the cannula casing. As corresponding second locking means, protrusions which axially protrude towards the cannula casing can be provided on the outer edge on the connecting element, which engage with the intermediate spaces of the teeth on the cannula casing in order to position the connecting element.
[0014] In some embodiments, it is sufficient for the present invention if the first and second locking means are arranged on partial regions of an annular area. The locking means can also, however, be provided on the entire annular area. There further exists the possibility of forming the locking means of the cannula casing and the locking means of the connecting element on the entire annular area on one of these parts and only on a partial region of the annular area on the other part. Preferably, in some embodiments, the first locking means of the cannula casing are formed on the entire circumferential annular area and the second locking means of the connecting element are only formed on an annular sector area. This division of the locking elements enables discrete positions to be provided on the entire circumference of the catheter head which are freely selectable when positioning the connecting element on the cannula casing.
[0015] In accordance with a preferred embodiment in accordance with the present invention, the fixing means can be formed by a releasable clamping connection between the cannula casing and the connecting element. Using such a clamping connection, the connecting element—once positioned—is fixed on the cannula casing in a selected rotational position. The clamping connection is preferably formed by at least one elongated opening slit through the connecting element. At least one outer region in the connecting element is defined by the opening slit and can be moved towards the center. The outer region can, for example, be moved in this direction by a pressure directed substantially onto the center of the connecting element. This pressure can, for example, be exerted by pressing the connecting element together between thumb and forefinger. When the pressure abates, the outer region is reset again. For the clamping connection, at least a first clamping element is arranged on the cannula casing. At least a second clamping element is arranged on the outer region of the connecting element defined by the opening slit, such that—like the latter—it can be moved when the outer region is pressed together. The second clamping element is arranged on the connecting element on a side facing the cannula casing and cooperates with the first clamping element. The elongated opening slits can begin on the edge of the connecting element and terminate in its interior, whereby the outer region is divided off from the connecting element as a type of arm. The elongated opening slit can however also lie completely in the interior of the connecting element. Care merely has to be taken that the elongated opening slit runs at least partially in the circumferential direction, in order to form a movable outer region of the connecting element.
[0016] In one preferred embodiment of the present invention, the first clamping element is formed by one or more first barbs extending in the circumferential direction at least on a partial region on the cannula casing and directed towards the connecting element. Preferably, a first barb is provided which is formed in the shape of an annular sector and arranged along an annular sector on the cannula casing. It is, however, also conceivable to arrange a number of barbs, for example, rectangular barbs, adjacently on the annular sector of the cannula casing. The second clamping element is formed by one or more second barbs which are embodied complementarily to the first barbs. Preferably, a second barb is provided which extends in the circumferential direction at least on a partial region on the outer region of the connecting element and is directed towards the cannula casing. This partial region is preferably also formed as an annular sector. A number of second barbs, arranged adjacently on the annular sector, are also conceivable. Furthermore, a single, elongated hook or hook shaped annular sector can be provided on the cannula casing and, correspondingly, one or more shorter hooks on the other of the two parts. It is advantageous to provide two elongated opening slits on an opposite side of the connecting element with respect to the center, whereby two outer regions are defined, having at least one barb each. In order to fix the cannula casing to the connecting element, the outer regions of the connecting element can be pressed together via the barb, such that said second barb can engage with a complementary first barb on the cannula casing. When fixing the connecting element on the cannula_casing using the fixing means, the first and second locking means of the guiding means can slide on each other. If, for example, protrusions are provided on an annular sector area of the connecting element as locking means of the guiding means, then when the outer regions are pressed together, said protrusions can slide along the complementary protrusions formed on the cannula casing when the outer region is pressed in.
[0017] Any other known or suitable clamping connection can also be used as the clamping connection of the fixing means, such as, for example, a positive lock plug connection including corresponding clamping elements on the cannula casing and on the connecting element.
[0018] In accordance with the present invention, it is also possible to provide the guiding means partially or completely on the fixing means. To this end, the function of the guiding means can, for example, be fulfilled by the first and second clamping elements of the fixing means cooperating. For example, a first locking means, such as teeth, pins or other suitable structures, can be additionally provided on the first clamping element and a second locking means, such as complementary teeth, holes or other suitable structures for the pins, can be additionally provided on the second clamping element. In this way, a particular locking setting can be selected as a discrete rotational position at the same time as the connecting element is fixed to the cannula casing.
[0019] By arranging the elements of the guiding and fixing means rotationally symmetrically about the center of the cannula casing or connecting element, respectively, the connecting element can be moved into a particular rotational position relative to the cannula casing, wherein due to their rotational symmetry, the respective complementary first and second locking and clamping elements oppose each other in a mutual fit and can cooperate in each rotational position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view, including a partial section through a catheter head in accordance with one embodiment of the present invention; and
[0021] FIG. 2 is a perspective view of a cannula casing in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION
[0022] FIG. 1 shows a catheter head in accordance with one embodiment of the present invention, comprising a circular, flat cannula casing 1 and a circular, flat connecting element 2 fixed to said cannula casing 1 . A cannula 3 protrudes from the cannula casing 1 , and in the drawing is directed substantially downwards, perpendicularly from the cannula casing 1 . The cannula 3 can, however, protrude from the cannula casing 1 at any other angle and therefore penetrate organic tissue at any angle. In the example shown, a wall 4 which is arranged annularly about a central opening protrudes upwards from the cannula casing 1 . The cannula 3 is guided though the central opening and secured by an insertion part 5 , i.e. a septum, inserted within the circumference of the wall 4 . The septum 5 also comprises a central opening which forms the passage channel 6 .
[0023] The connecting element 2 comprises a fluid supply 7 which feeds into a tube-like central continuation 8 arranged centrally in the middle of the connecting element 2 . The continuation 8 is guided along the central opening of the septum 5 until it feeds into the cannula 3 , whereby a liquid connection from a fluid container (not shown, but typical) via the fluid supply 7 and the cannula 3 into the organic tissue is established. If the connecting element 2 is only partially inserted into the central opening of the septum 5 , it can be rotated about the axis of the tube-like continuation 8 —which at the same time also represents the extension of the longitudinal axis of the cannula—relative to the cannula casing.
[0024] In the example shown in FIG. 1 , the guiding means is formed in accordance with the present invention by first protrusions 9 on the cannula casing 1 and by second protrusions 10 on the connecting element 2 . The protrusions 9 are arranged on an outer annular area of the cannula casing 1 which points upwards, wherein the first protrusions on said annular area extend or are aligned generally radially with respect to the center of the cannula casing. The second protrusions 10 of the connecting element 2 are arranged on the circumferential edge area of the connecting element 2 , wherein the edge of the connecting element 2 with the second protrusions 10 is curved towards the cannula casing 1 in such a way that the second protrusions 10 are arranged generally opposite the first protrusions 9 . The second protrusions 10 therefore also run, extend or are aligned generally radially towards the center of the cannula casing 1 or connecting element 2 , respectively.
[0025] When placing the connecting element 2 onto the cannula casing 1 , i.e., when inserting the continuation 8 into the central opening of the insertion part 5 , the connecting element 2 can be rotated relative to the cannula casing 1 , until the fluid supply 7 is led away from the catheter head in a desired direction. This selected position either directly corresponds to one of the discrete rotational positions of the guiding means or can be moved into a nearby position corresponding to a discrete rotational position by a slight, negligible angular movement. This discrete rotational position is determined by the second protrusions 10 on the connecting element 2 engaging with the intermediate space, opposite in this position, between the first protrusions 9 on the cannula casing 1 . When the connecting element 2 and the cannula casing 1 are further joined together, these two parts are guided by the protrusions 9 and 10 which slide into each other. In order to enable the discrete positions to be located and the continuation 8 to be gently inserted, the protruding sides of the protrusions are arranged obliquely with respect to their base area. The connecting element 2 is inserted into the cannula casing 1 until the second protrusions 10 rest on the base area of the intermediate spaces of the first protrusions 9 . In this state, the continuation 8 protrudes into the cannula 3 to a certain depth, in order to ensure the fluid connection. If a different rotational position of the connecting element 2 relative to the cannula casing 1 is desired, the connecting element 2 is raised slightly from the cannula casing 1 , until the engagement between the protrusions 9 and 10 is released. The connecting element 2 can then be rotated again relative to the cannula casing 1 , until a desired new rotational position has been reached. By pushing the connecting element 2 and the cannula casing 1 together, the second protrusions 10 of the connecting element 2 are then inserted into the intermediate space between the first protrusions 10 of the cannula casing 1 , now opposite them in accordance with the new discrete rotational position. When the connecting element 2 is raised from the cannula casing 1 in order to change a rotational position, the continuation 8 preferably remains in the central opening of the septum 5 , preferably in the cannula 3 , at least via its tip, in order to not interrupt the fluid connection despite the change in rotational position.
[0026] In order to form the fixing means, two elongated opening slits 11 through the connecting element 2 are arranged in accordance with the invention in the example shown in FIG. 1 . The slits begin from the edge of the connecting element 2 and initially run substantially towards the center of the connecting element 2 , then pass into a part running substantially in the circumferential direction, and terminate in a part running substantially radially outwards again before the edge of the connecting element 2 . Accordingly, they are formed in generally curved or wave shape. Two outer regions 12 of the connecting element 2 are defined by these opening slits 11 . The outer regions each form a sort of arm of the connecting element 2 , which can be moved towards the center of the connecting element 2 if a pressure is exerted on the outer regions from the edge.
[0027] A first barb 13 is provided on the cannula casing 1 , as a first clamping element of the fixing means, and protrudes upwards from the cannula casing 1 towards the connecting element 2 . The first barb 13 is preferably formed by a projection protruding towards the center of the cannula casing 1 and is circumferentially arranged on the entire circumference of the cannula casing, annular about the center of the cannula casing 1 . It is, however, also possible to only arrange the barb on circumferential sectors. On the connecting element 2 , second barbs 14 protruding downwards towards the cannula casing 1 , complementary to the first barb 13 , are arranged on the outer regions 12 , as second clamping elements of the fixing means. The barbs 14 extend in the circumferential direction on the edge of the part of the opening slits 11 running in the circumferential direction. The second barbs 14 can run continuously along the part of the opening slit 11 running in the circumferential direction or can be interrupted.
[0028] When placing the connecting element 2 onto the cannula casing 1 , the outer regions 12 of the connecting element 2 are pressed together, e.g., by the thumb and forefinger, such that the second barbs 14 move towards the center of the connecting element 2 and, when the connecting element 2 is inserted into the cannula casing 1 , are guided past the first barb 13 of the cannula casing 1 . Preferably, the outer regions 12 can be moved far enough inside that the second barbs 14 do not rub on the first barb 13 .
[0029] If a rotational position has been selected and the cannula casing 1 and the connecting element 2 guided completely into each other in said rotational position, the pressure on the outer regions 12 is reduced and the barbs 13 and 14 interlock into each other in a clamping connection. If a new rotational position is to be selected, the outer regions 12 are pressed together again, in order to release the clamping connection of the barbs 13 and 14 , such that the connecting element 2 can be at least partially raised from the cannula casing 1 , at least until the locking connection of the guiding means is released. The connecting element 2 and the cannula casing 1 can then be rotated relative to each other, into a new desired rotational position. By pushing the cannula casing and the connecting element completely together when the outer regions 12 are pressed in, the second protrusions 10 can in turn engage with the intermediate spaces between the first protrusions 9 , corresponding to the new rotational position. By abating, reducing, or relieving the pressure on the outer regions 12 , the barbs 13 and 14 interlock into each other and the connecting element 2 is fixed on the cannula casing 1 in this new discrete rotational position.
[0030] In the exemplary embodiments shown in FIG. 1 , the first protrusions 9 are provided on the entire circumferential area of the cannula casing 1 , whereas the second protrusions 10 of the connecting element 2 are only provided on the edge of the regions between the movable outer regions, i.e., second protrusions 10 are not provided on the edge of the outer regions in the example shown. This facilitates the engaging of the clamping elements 13 and 14 . It would, however, be equally possible to also attach second protrusions 10 to the edge of the outer regions 12 . These second protrusions 10 would then slide along the first protrusions 9 when the clamping elements 13 and 14 engage and the pressure on the outer regions 12 is abated.
[0031] It is also conceivable to provide the first and second, mutually complementary locking elements of the guiding means on the mutually facing areas of the clamping elements 13 and 14 . To this end, corresponding cooperating protrusions could, for example, be provided on the projections of the barbs 13 and 14 . In this case, the guiding means and the fixing means would be combined into one means.
[0032] FIG. 2 shows a cannula casing 1 of another exemplary embodiment of a catheter head in accordance with the present invention, which is also formed circularly and from which a cannula protrudes downwards (not visible in FIG. 2 ). In this embodiment, the guiding means in accordance with the present invention is provided on the wall 4 arranged around the central opening. In order to form a locking connection between the cannula casing 1 and a connecting element, to provide the discrete rotational positions in accordance with the invention, protrusions 15 —preferably triangular—are provided on the wall 4 , generally in the circumferential direction around the wall. Through these triangular protrusions 15 , the outer circumference of the wall 4 is formed in a sort of star shape. It is then possible for adjacent wall areas of adjacent triangles to be orientated in the same direction and therefore to form a joint area, or for a recess to be created between adjacent triangles when the adjacent areas of these triangles are at an angle with respect to each other. Furthermore, the protrusions 15 provided on the wall 4 do not have to be formed triangularly, but can, for example, also be quadrangular, can be formed by curves or can have any other suitable configuration.
[0033] The discrete rotational positions are provided by the protrusions 15 formed on the circumferential area of the wall 4 , by an intermediate space 16 between two protrusions 15 , which is formed, for example, by adjacent wall areas of adjacent triangular protrusions 15 , corresponding to a discrete rotational position. The number of discrete rotational positions of a catheter head in accordance with the present invention can be varied by varying the number of protrusions on the wall 4 .
[0034] On the connecting element corresponding to the cannula casing 1 of an embodiment as set forth in FIG. 2 , a wall can be provided around the continuation 8 , the wall protruding from the connecting element towards the cannula casing 1 . Protrusions can be provided on an inner circumferential area of the wall which run complementarily to the protrusions 15 of the cannula casing 1 . In case intermediate spaces 16 are formed by the protrusions 15 on the outer circumferential area of the wall 4 of the cannula casing 1 , as shown in FIG. 2 , the protrusions on the inner circumferential area of the wall of the connecting element are formed in such a way that they fit into said intermediate spaces 16 . To this end, triangular protrusions having an obtuse angle can, for example, be provided. If adjacent areas of adjacent protrusions 15 on the wall 4 of the cannula casing 1 form a joint area, the inner circumferential area of the wall of the connecting element is formed as a polygon having inner areas corresponding or complementary to the joint areas of the protrusions 15 . If the protrusions 15 on the outer circumferential area of the wall 4 are provided by curves, then curves can also be formed on the inner circumferential area of the wall of the connecting element, said curves fitting into the intermediate spaces 16 .
[0035] In the embodiment depicted in FIG. 2 , the fixing means for a releasable clamping connection comprises an annularly circumferential elevation 17 on an outer region of the cannula casing 1 . A number of elongated recesses 18 running in the circumferential direction are provided in the inner circumferential area of the elevation 17 . On a connecting element corresponding to this fixing means, clamping elements on the movable outer regions 12 can be provided with a protrusion which fits into the recesses 18 .
[0036] A discrete rotational position is selected for the catheter head and the clamping connection between the cannula casing and the connecting element is established analogously to the embodiment described with reference to FIG. 1 . In order to facilitate removing the connecting element 2 by pressing the outer regions 12 together and raising it off the cannula casing 1 , guiding blocks 19 for the clamping elements are provided in front of the recesses 18 on the base area of the cannula casing 1 . Preferably, the recesses 18 and the intermediate spaces 16 are arranged opposite each other and the guiding blocks 19 are arranged between the recess 18 and the intermediate spaces 16 . The guiding blocks 19 are preferably formed as wedge-shaped ramps, such that they comprise a guiding area which rises in the radial direction from the edge of the cannula casing 1 . A clamping element of the connecting element, when raised by pressing the biased outer regions 12 together, is repelled upwards from the cannula casing, along said guiding area.
[0037] On or adjacent to the edge of the cannula casing 1 , flaps 20 are provided on opposite sides and serve, for example, to hold the cannula casing 1 on the surface of the tissue when the connecting element is raised.
[0038] The embodiments shown in the drawings are to be understood to be exemplary and are not intended to restrict the scope of the invention. In particular, the angular arrangement of the cannula 3 and the fluid supply 7 of the catheter head in accordance with the present invention can be altered.
[0039] In the foregoing description, embodiments of the present invention, including preferred embodiments, have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principals of the invention, methods of making the invention, and the practical application and use of the invention, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth they are fairly, legally, and equitably entitled. | A catheter head, for introduction of a fluid into an organic tissue, including a cannula housing with a cannula, a connector element with a fluid inlet, a guide and a fixing device. The guide device has several selectable discrete rotational positions for positioning the connector element relative to the cannula housing about a longitudinal axis of the cannula. The connector element, positioned in a rotational position, is detachably connected to the cannula housing in the selected position by means of the fixing device. | 0 |
FIELD OF THE INVENTION
The present invention relates to gas twist grips for handlebars of motor-driven two-wheeled vehicles with a housing fastened on said handlebar, and with a tube mounted rotatable thereon and held axially immovable by said housing, said tube being rigidly joined with a drum accommodating a bowden cable, and further with a rotatable roll for said bowden cable.
BACKGROUND OF THE INVENTION
In presently known gas twist grips of this type the bowden cable must be passed through a hole in the housing and then hung into the drum holding this cable. These operations are cumbersome and achieved only with great difficulty. It thus constitutes a very time-consuming process which can lead to critical losses of time when a broken bowden cable has to be quickly exchanged, as for example in motorcycle races.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to improve gas twist grips of the type mentioned above to such an extent as to allow easy and quick suspension of the bowden cable into the drum provided for the said bowden cable.
According to the invention, this object is achieved in that the housing has a continuous slit for suspending the bowden cable and furthermore is closed above the return roll by way of a detachable lid.
BRIEF DESCRIPTION OF THE DRAWINGS
The following description of preferred embodiments of the invention given on hand of the attached drawings will explain more fully the essence of the present invention. In the said drawings,
FIG. 1 shows a side view of a gas twist grip;
FIG. 2 shows a partially exposed top view of the gas twist grip of FIG. 1;
FIG. 3 shows a sectional view along line 3--3 of FIG. 1;
FIG. 4 shows a view similar to FIG. 3, but with a different arrangement of a cable drum;
FIG. 5 shows a sectional view along line 5--5 of FIG. 2, and
FIG. 6 shows a perspective partial view of a gas twist grip with the lid of the housing removed.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the right side of a handlebar 1 of a motor-driven two-wheeled vehicle made in the conventional manner from metal tubing. A tube 2 made of plastic is mounted rotatable on handlebar 1, on which tube a sleeve 3 made of rubber or the like is placed so as to be rigidly fixed thereon. This sleeve 3 is gripped with the right hand of the driver. By twisting sleeve 3, tube 2 on handlebar 1 will likewise be twisted.
A housing 5 is furthermore fastened by means of screws 4 on handlebar 1, said housing enclosing the part of tube 2 which protrudes from sleeve 3. The part of tube 2 surrounded by housing 5 is designed as cable drum 6 on which one end of a bowden cable 7 is fastened in the customary manner by means of a nipple 8. In said housing 5, furthermore, a return roll 11 for the bowden cable is rotatably mounted by means of a screw 9. This return roll allows the bowden cable to be led out of housing 5 parallelly to the axis of handlebar 1. The point where bowden cable 7 emerges from housing 5 is conventionally covered over by means of a rubber socket 12. With a turning of tube 2, cable 7 will wind onto or off drum 6 so as to control the fuel amount to the motor of the two-wheeled vehicle in the manner known per se.
To be able to insert the bowden cable into the housing and join it with cable drum 6 smoothly, the following measures are used according to the invention: housing 5 has at the point where sheathing 10 of bowden cable 7 is conventionally joined with the housing by means of screws and nuts a slit 13 open toward the top into which bowden cable 7 can be easily inserted from above (see FIG. 6). The said bowden cable 7 is then placed about return roll 11 and can then be hung with the greatest of ease from above, by means of nipple 8, into a corresponding groove provided on drum 6. The open upper side of housing 5 (see FIG. 6) can be closed off by means of a lid 14 which corresponds to the shape of said housing. Lid 14 is joined by means of a safety ring 15 rotatable, but axially immovable, with the threaded spindle 16 (screw spindle) of a knob 17 which, when assembled, lies above lid 14. Knob 17 is provided with lateral grooving in the conventional manner so that it can be easily turned by hand. The said knob has, furthermore, on its upper side (see FIG. 2) a slit 18 into which a coin or the like can be inserted so as to loosen the previously tightened knob. Since lid 14 is joined rotatable but axially immovable with screw spindle 16 of knob 17 said lid will rise from the upper side of housing 5 when knob 17 is loosened so that the bowden cable 7, as a result of the space opened thereby, can be easily inserted, placed about the return roll 11, and joined with cable drum 6. Screw spindle 16 engages thereat in a tapped hole inside screw 9 holding the return roll 11 (see FIG. 5). If necessary, the lid 14 thus slightly raised after loosening of knob 17 can be twisted also relatively to the housing 5, thus resulting in a partial exposure of its upper side and further facilitating the insertion of the bowden cable 7.
As shown in FIGS. 2 and 6, lid 14 can have a slit 19 at the point where it is pierced by screw spindle 16 and joined by safety ring 15 with said spindle, which slit 19 will furthermore enable a lateral displacement of the raised lid relatively to the housing, thus resulting in an additional space between housing 5 and lid 14 which will likewise facilitate the insertion of the bowden cable.
In a further embodiment of the invention, the screw spindle 16 of knob 17 can serve simultaneously as the spindle for return roll 11. It is preferable, however, to use the screw 9 designed as hollow screw so that the return roll 11 is held inside the housing independently of the lid.
As evident from FIGS. 3 and 4, the cable drum 6 has two areas 21, 22 of different diameters with which slots 23 and 24 respectively for the hanging of bowden cable 7 are associated. By turning 180°, the cable drum 6 which in this case is designed as a component detachable from tube 2, but positively lockable with the same can be arranged as shown in FIG. 3 or as shown in FIG. 4. If arranged as in FIG. 3, the bowden cable 7 winds itself onto the part 21 of drum 6 that has a larger diameter, while when arranged as in FIG. 4, the said bowden cable 7 winds itself on the part 22 of drum 6 that has a smaller diameter. In this manner, a specific "transmission" between tube and displacement of bowden cable 7 can be set, all according to what particular sensitivity of adjustment is desired.
Although lid 14 can be completely detached from housing 5 by an appropriate loosening of knob 17, this is normally not required for the insertion of a bowden cable 7. A few turnings of knob 7, easily executed by hand, will suffice to raise the lid 14 from the housing far enough to allow the cable 7 to be inserted first into slit 13 and then into housing 5. If warranted, lid 14, after having been slightly raised from the housing, can additionally be shifted sideways by way of the aforementioned slit 19. In addition to the above, the main advantage consists in the fact that, due to its relatively large diameter, the knob can easily be actuated by hand and thus requires no special tool for loosening of lid 14 from housing 5. | An improved twist gas strip for the handlebar of a motorcycle or the like in which a bowden cable return roll housing has a continuous slit for suspending the bowden cable, which slit is closed above the return roll by a detachable lid. | 8 |
DESCRIPTION
The invention relates to a device and the use of a device for welding together at least two parts, using an arc welding or resistance welding procedure, in particular an arc pressure welding procedure, in which a first part remains stationary and a second part, held in a holding device, can be moved backwards and forwards relative to this first part by means of an actuating device in a welding head, and in which the second part can be aligned relative to the first part by means of a positioning drive (manipulator) for positioning the welding head.
A device of this kind, by means of which arc pressure welding can be carried out, is already known. This latter process is used, for example, in the field of automotive engineering or automobile body assembly. In this process, a small part, for example, is welded to a larger part, and in particular a bolt is welded to a part of an automobile body. The second part is precisely aligned in relation to the first part, and this can be done by means of a known type of positioning drive (manipulator). The actuator then causes the second part to move relative to the first part, for example by executing a feed motion, possibly after first lifting up the second part. In the case of resistance fusion welding, the fusion between the two parts is generated by electrical resistance. In the case of resistance pressure welding, as the current flows through, the electrical resistance in the weld zone generates the heat necessary for the welding process. The bonding of the points to be connected is achieved by pressing the parts together. This type of welding includes, for example, also spot welding and projection welding. In the case of arc welding, an electric arc burns between the two parts, one of which is usually a welding electrode which melts during the welding process.
In the case of arc pressure welding, an electric arc is struck between the first and second parts, both of which melt at the faces in contact with the ends of the arc. Then, the second part is moved relatively rapidly towards the first part so that the two weld puddles are united. With the hardening of the combined weld puddles, the two parts become welded together. Whatever the case, the important factor here is the relative movement of the first and second parts, one of which as a rule remains stationary while the other part is moved towards it, and this feed motion may be preceded by movement in the opposite direction. The latter motion may be dispensed with if, due to its special shape, the part being fed is shortened by being partially melted away before the general strong melting of both parts commences.
In a known device used for arc pressure welding, the second part is approached to within a predetermined distance from the first part; this can easily be accomplished using either a supporting foot or a tripod. The second part, e.g. a bolt held in a welding head, which is to be welded to the first part, is exactly positioned relative to the first or base part, e.g. a car body. In this process a usually pneumatically operated carriage moves the actual welding stroke mechanism, carrying the bolt to be welded, towards the first, stationary part. The force with which the bolt is pressed against the base part when the two parts are being welded together is not freely adjustable, unless the system is mechanically converted. The supporting foot requires a free space of about 30 mm around the bolt to be welded, and no disruptive contours may be present in this space.
The welding process is initiated by triggering a preliminary welding current. Using a lifting device, usually a solenoid, and while the preliminary welding current is still being applied, the bolt is raised against a return-action device, in particular a return spring, until a fixed stop is reached. Here again, unless the system is mechanically converted, the welding stroke length can be adjusted only once.
The preliminary welding current which is applied generates a weak electric arc. The main welding current is triggered once the maximum stroke length has been travelled and it generates the weld puddle required for the welding process. When the current energizing the electric lift magnets is switched off, the return spring causes the second part to be suddenly moved towards the first part, so that the second part is plunged at maximum velocity into the weld puddle of the first part. Some splattering of the weld puddle is unavoidable.
The plunge into the weld puddle occurs in a largely unregulated manner and, among other things, depends on the spring rate. Because of the largely uncontrolled plunging process and the speed at which the plunging is carried out, it is almost impossible to prevent faulty welds from being produced. The unsound welds are also caused in particular by vibration events which are initiated when the second part impacts on the first part.
Because--at least after an initial setting has been carried out--most of the settings made to one and the same device cannot be changed, e.g. the spring rate, the pretensioning of the spring, the performance data of the solenoids, the stroke length, etc., fluctuations in the tolerances of the two parts have a negative effect in a series. It is also not an easy matter to replace, for example, one type of bolt by another without first readjusting the basic setting. Once the initial adjustment has been made, it is no longer possible to influence the acceleration and the speed at which the bolt is fed; instead, the second part always impacts at high speed onto the first part, and this can cause loss of the molten metal in the weld puddle due to splattering, thereby resulting in a faulty weld. How much material is lost because of splattering depends in each case on the combination of tolerances. Gentle plunging into the weld puddle is not possible. Furthermore, with this type of device the welding position also plays a role, i.e. different results are obtained depending on whether the weld is carried out in an upward, downward or lateral direction. However, when welding guns are used, welding is usually carried out in all directions.
A bolt-welding device of the type referred to at the beginning is known from DE 34 14 522 C1. In this device, a bolt which is to be welded is fed by means of the welding head to the workpiece. The feed motion takes place at first at low force until an actuating tappet opens a valve, so that the rest of the feed distance can be travelled with a high level of force being exerted. This device reduces the risk of injury to the operator. JP-A-42 00 981 describes a bolt-welding device which operates at low pressure during the learning program and at high pressure during the work program. This reduces the risk of damage to the components.
As a result, there is a need to improve the design of a device of the type described at the beginning in such a way that the disadvantages listed are avoided and optimal welding results can be achieved with the lowest possible rejection rate. The aim is, above all, to achieve reproducible results; this requires minimizing or even eliminating the aforementioned vibrations when the two parts impact on one another. In addition, the welding direction should not have a negative influence on the welding result.
In order to solve this task, in the manner according to the invention, it is proposed that, in the device referred to at the beginning, by using a manipulator for the welding head, the second part can be aligned relative to and can be pressed against the first part; in each case the position of the holding device relative to the welding head can be determined by means of a path-measuring system, and after the second part has been pressed against the first part, the movements of the second part relative to the first part can be executed by means of the distance-measuring system according to set-point control commands.
The path-measuring system and an actuator for the device that holds the second part are essential elements of this device. By means of a manipulator, e.g. a robot arm, which may be conventional both in design and in the manner of control, the second part, e.g. a bolt to be welded into place, is precisely oriented relative to the weld point on the first part. Next, in the case of the arc pressure welding process, the second part is pressed in the manner described against the first part, while the welding current is still switched off. Regardless of the tolerances of the parts to be welded together, the position of the device holding the second part is determined relative to the welding head by means of the path-measuring device; this position is taken as a zero setting. Next, the second part is lifted off the first part, after the preliminary welding current has been switched on. This lifting action is carried out in a controlled manner by a freely selectable amount, starting from the established zero point. In this way, the height by which the second part is raised up can be precisely maintained, regardless of the tolerances. Once the main welding current has been triggered, the second part is moved towards the first part, and the main welding current causes weld puddles to form on both parts in the area of the intended weld point. Once again, the feeding of the second part towards the first part is carried out accurately with the aid of the path-measuring system, and the feed distance can be slightly longer than the lift-off distance, because the second part must be plunged into the weld puddle of the first part, and it has also become slightly shorter due to the formation of the weld puddle. Once the weld puddle solidifies, the second part is released from the holding device. It is now firmly welded to the first part.
If a bolt with a meltable tip is used in the arc welding process, the lift-off movement prior to the main welding current being triggered can be wholly or at least partially dispensed with, because a relative lift-off of the bolt is achieved by the melting of the tip. In this case also, the position of the bolt is accurately determined or accurately taken up prior to the preliminary welding current being triggered, and it is used as the reference point for the following movement or movements of the bolt.
With the help of the program controller, the data or adjustment values which have been determined or entered can be processed in a predetermined manner, and they can be taken into account in any desired manner when determining the acceleration and deceleration and/or the speed each time the system is re-set. This also permits the harmful vibratory movements to be eliminated, and above all any dimensional tolerances between the two parts can also be eradicated. The respective part can be gently plunged, as required, into the weld puddle.
It is clear from the foregoing that this device can also be used with the other welding processes mentioned and is not restricted to the arc pressure welding process using weld-on bolts. For the sake of simplicity, however, reference is made in the following solely to the arc pressure welding method with weld-on bolts, although this should not be interpreted in a restrictive sense.
In a further embodiment of the invention, the actuator of the holding device is a double-acting working cylinder, especially a servo-pneumatic or servo-hydraulic cylinder. The extendable part of the working cylinder, for example the piston rod of the cylinder, carries the holding device for the weld-on bolt. The welding head is oriented relative to the weld point in such a manner by the manipulator, e.g. a robot arm, that the weld end of the bolt is arranged exactly over and at a short distance from the weld point. Using the manipulator, the bolt is now placed in contact with and pressed onto the weld point. The robot arm can be moved at maximum speed up to its end position. The overall sequence of movement is continuous. When the bolt is pressed onto the weld point, this compensates for all the tolerances between the tools and the workpieces. By pressing the bolt against the weld point, the piston rod of the servo-pneumatic system is forced back into the cylinder. At the same time, with the aid of the path-measuring system, the position now occupied by the holding device in relation to its starting position, or in relation to the welding head, is determined. The new position, after the piston has been pressed into the cylinder, preferably corresponds to a travel distance of zero. Using the actuator, the bolt can then be raised by a freely selectable amount from the first part, and this amount is then an exact parameter which is independent of the bolt tolerances and similar.
Preferably, before the bolt is pressed against the vehicle body, the pressure in the servo-pneumatic system is reduced so that the piston can be pushed back into the cylinder without any problem. Once the robot arm has reached its end position, i.e. once the bolt has been placed in contact with and pressed against the vehicle body, and the piston has been forced back into the cylinder, the position at that moment is entered as the set-point and the pressure in the servo-pneumatic system is increased again.
In the case of a bolt having a meltable tip, it may be possible, once the tip has melted, to forego the lift-off action prior to triggering the main welding current.
By using a double-acting cylinder, and starting from the raised position of the bolt, the downward movement of the bolt can be executed in a predetermined, but freely selectable manner, by applying appropriate pressure to the piston.
The invariable force and movement characteristics of the return spring used in state-of-the-art systems are replaced in this case by the precisely selectable and controllable force and movement characteristics of the servo-pneumatic system, whose piston (or cylinder) can be manipulated with any desired choice of speed, acceleration and deceleration, as well any desired amount of force.
As the device holding the bolt is moved towards the weld point by means of the robot arm, the pressure in the working cylinder is reduced. Once the bolt has been positioned on the weld point, the welding head, as already explained, is moved further towards the second part, thus resulting in the piston, carrying the holder and the bolt, being displaced relative to the welding head. Once the robot arm has reached its end position, the position of the holding device, i.e. of the servo-pneumatic system, is determined using the path-measuring system and this position is used as the reference position for all further positioning movements.
According to a further embodiment of the invention, in order to obtain an exactly predetermined feed action in terms of acceleration, speed and deceleration after the main welding current has been initiated, the position of the piston in both chambers of the cylinder of the actuator is determined by means of a measuring and control device and can be regulated as a function of time and/or travel distance. When the weld faces of both parts have been melted in the desired manner, the bolt can initially be moved with maximum acceleration and at maximum speed right up close to the first part and then, in particular to avoid splattering of the weld puddle, the movement can be maximally decelerated to ensure that the bolt plunges gently into the weld puddle. Because these parameters are freely selectable or can be programmed into the computer, it is a simple matter to switch from one type of bolt to another. The same applies in the case of different first parts, e.g. different thicknesses of automobile body sheet metal, and the other described adjustments.
When a weld-on bolt is used, the holding device employed is a spring chuck, a spring sleeve, or similar, all of which are very commonly used in practice; whereas, when the second part takes the form of a sheet metal part, an appropriate holding device is provided which is correspondingly designed and built to match the shape of this second part.
The task of the invention is furthermore to create a procedure which can be implemented using the device according to the invention.
In the manner according to the invention, this task is solved by a procedure having the procedural steps listed in claim 7.
Indirectly, these procedural steps have already been mentioned in connection with the explanation given of the device according to the invention. On the other hand, however, this procedure is also described in the following, in connection with describing an embodiment of the invention.
Further features of this procedure and other functional operations and advantages of the device according to the invention and of the procedure, may be derived from the following description of an embodiment of the invention.
The invention is described in more detail in the following on the basis of the drawing, in which:
FIGS. 1a-1d Depict in diagrammatic form, and in four sequential phases designated a to d, the welding head with the holding device, the path-measuring system, the actuator, and the second part, having the form of a weld-on bolt.
FIGS. 2A-2I Depict the sequence of the procedure according to the invention, in nine sequential phases designated A to I.
FIG. 3 Is a diagram showing the current curve and the movement curve for the procedure depicted in FIG. 2.
To a first part 1, for example a vehicle body, a second part 2, in particular a bolt, is to be welded using, in the embodiment described here, the arc pressure welding method. In the drawing, the first part 1 is merely schematically indicated and the second part 2 may also be designed differently from the way in which it is depicted here. For example, it may be provided with a welding foot or also with an arc-initiation tip 3, which is indicated by broken lines in phase a in FIG. 1. The second part--which is hereinafter merely referred to as "bolt 2"--is held in a holding device 4 which may have the form of or may be fitted with a spring chuck, a spring sleeve or similar. The holding device 4 is mounted on a welding head 6 so that it can be advanced or retracted in the directions indicated by the double arrow 5; the vertical feed direction is seen here in relation to the first part. The welding head 6 can itself also be adjusted, preferably in all three coordinate directions, in a known manner using a manipulator 8, in particular a robot arm 7. It is in particular intended that the welding head 6 be held and moved by a robot arm 7. This is achieved with the aid of a symbolically depicted robot arm 7. The positioning motions of the robot arm 7 are depicted symbolically by the three arrows 9 which are intended to denote the three directions in a system of coordinates.
It is thus possible in this way to align the bolt 2 or its geometrical axis precisely in relation to the weld point of the first part 1.
In phase a of FIG. 1, the bolt 2 is shown positioned a short distance above the weld point. The alignment was accomplished by positioning the welding head 6 with the aid of the robot arm 7. In addition to the holding device 4, the robot arm also carries a preferably electronically operating path-measuring system 10 as well as an actuator 11 for the holding device 4. These elements are linked, via schematically indicated leads, with a program controller 12, also merely schematically indicated, having a control unit for inputting parameters. This will be discussed in more detail in the following.
In the position which the welding head 6 has reached in phase a, the holding device 4 is in one of its end positions, preferably its lower end position in the embodiment shown in the drawing. As a result, the full measuring range or measuring pathway of the path-measuring device 10 is also available.
If, proceeding from phase a in FIG. 1--and initially without taking account of an arc-initiation tip 3--the bolt 2 is advanced towards the assigned surface 13 of the first part, to which surface it is to be welded, by moving the welding head 6 in the appropriate direction, the second part 2 will ultimately come into contact with the first part 1. If, however, the welding head 6 is then moved further downwards by means of the robot arm 7, the bolt 2 can no longer follow this further downwards motion. Consequently, the holding device 4 is displaced upwards relative to the welding head 6. Each position, and especially this relative displacement, can be recorded by the path-measuring system 10. The end position is reached when the robot arm 7 has reached its programmable end position. Up to this end position, the robot arm 7 can travel at maximum speed.
The actuator 11 may preferably be a double-acting, servo-pneumatic working cylinder. Before the bolt 2 is pressed against the part 1, the pressure in both chambers of the cylinder is reduced. If it is assumed that in phase a of FIG. 1 the piston has reached its lower end position in this working cylinder, then when the bolt 2 is in contact with the first part 1 and the welding head 6 is advanced in the direction of the arrow 14, the piston will in relative terms be displaced upwards, i.e. to be strictly accurate, the cylinder will move downwards relative to the piston.
The end position of the robot arm 7 or of the welding head 6 is exactly determined with the aid of the path-measuring system 10. This position corresponds to a zero position of the bolt 2 relative to the first part 1 or the vehicle body.
A value for further raising the holding device 4 relative to the welding head 6 can be entered into the program controller 12. Starting from the position it has reached in phase b relative to the first part and to the welding head 6, after being pressed against the first part, the bolt 2 can be raised up in the direction of the arrow 15, with the help of the actuator 11, via the servo-pneumatic system, by an exactly prescribed and freely selectable value which, as mentioned, is entered into the program controller 12. The position shown at phase c in FIG. 1 is then attained. Between phase a and phase c, the pressure in the working cylinder was reduced in order to permit the piston to be pressed into the cylinder without any difficulty. Starting from the position in phase c, the bolt 2 is lowered by means of the working cylinder towards the first part 1. By means of the program controller, a feed action having any desired characteristics can be achieved. In particular, the system is designed so as to permit the precisely defined spacing (phase c) between the bolt 2 and the first part 1 to be traversed at high speed; then, just before it reaches the surface 13 of the first part 1, the bolt continues to be lowered but at a considerably reduced speed. The rapid travel phase is preceded by a phase of high acceleration and it ends with a phase of strong deceleration.
As the transition is made from phase b to phase c, an electric arc is initiated by triggering a preliminary welding current.
Once the defined raised position of the bolt 2 according to phasec is attained, the main welding current is triggered, thus initiating a powerful arc which causes the end of the bolt and the opposite zone of the first part to melt. When the bolt 2 is then lowered, its liquefied or softened leading end is gently plunged into the liquefied material at the surface 13 of the first part 1, the weld puddles are combined and the welding process takes place.
It is easy to see that, by being able to freely choose the various parameters, but especially the acceleration and preferably also a variable speed for the bolt 2, as well as the regulation of the welding current in conjunction with the regulation of the travel during the downwards movement, which is also undertaken with the aid of the path-measuring system 10, the depth of penetration of the bolt 2 into the weld puddle of the first part 1 can be exactly specified, and this is very important, especially in the case of thin metal sheets as used in automobile, i.e. vehicle body, construction.
When the bolt 2 is fitted with an arc-initiation tip, the procedure according to the invention can still be carried out with the device according to the invention. The retraction stroke, i.e. the lift-off motion of the bolt 2, can be omitted during the transition from phase b to phase c. However, it is also possible to execute a shortened retraction stroke. When the welding current is triggered, the arc-initiation tip 3 melts away, and it is solely due to this process that bolt 2 occupies the position attained in phase c, namely after the arc-initiation tip in contact with or pressed against part 1 has been melted away, with bolt 2 displaced as shown in phase b. If it is decided not to additionally raise the bolt once the arc-initiation tip has melted, the transition from phase b to phase d can immediately be made with this bolt 2. At any rate, the melting away of the arc-initiation tip corresponds at least partially to the raising of the second part relative to the first part during the transition from phase b to phase c.
FIG. 2 shows the procedural sequence in slightly more detail than FIG. 1, although again only in diagrammatic form. In contrast to FIG. 1, in FIG. 2 the holding device 4 is attached directly to the lower end of the piston rod 16 of the manipulator 8, whereas in FIG. 1 the lateral connection of the piston rod with the holding device 4 is not shown because such detail is not important. All that matters is that the holding device 4 in each case executes the lifting and lowering motions along with the piston and the piston rod.
In phase A, the holding device is opened, but it is already aligned in such a way relative to bolt 2 that this bolt is gripped when the holding device closes. This is shown in phase B. The gripping of the bolt and the transportation of the bolt to the weld point can take place in a known manner according to a programmed control sequence.
Phase C represents the positioning of the bolt 2 above the first part 1. In phase D the bolt 2 is placed in contact with the weld point. Next, according to phase E, the welding head 6 is lowered further towards the first part 1, and this causes the piston and thus also the piston rod 16 with the bolt 2 to be forced into the cylinder in the direction indicated by the arrow 15. This is followed by the lifting of the bolt 2 in accordance with phase F and phase c in FIG. 1. As indicated schematically, the preliminary welding current (VS) is triggered during these steps and an electric arc is formed. In phase G, the main welding current (HS) is triggered so that a powerful electric arc is formed, with the result that the two parts 1 and 2 which are to be joined to one another undergo melting in the areas at the ends of the electric arc.
Phase H corresponds again to phase d in FIG. 1; namely, once the weld puddle has formed, the bolt 2 is pressed firmly into the weld puddle on part 1. In phase I, the welding head 6 with the holding device 4 is moved away from the welded-on bolt 2.
FIG. 3 illustrates diagrammatically the position of the piston in the cylinder or the tap-off S on the path-measuring system 10. In addition, this diagram also presents the path of the current strength over time; the abbreviation "VS" denotes the preliminary welding current and the abbreviation "HS" denotes the main welding current. This diagram indicates the correlation of the movements with the on/off switching of the welding current.
It is easy to see that, instead of a bolt-shaped second part 2, a second part of any other desired shape can be welded in the manner described to a first part 1. The use of the arc initiation tip is comparable, for example, to the projection welding process.
It follows clearly from the foregoing that the procedure according to the invention and the associated device avoid the disadvantages of conventional welding performed in the manner described above, because now the bolt 2 is no longer forced into the weld puddle by the robot-guided welding head under the action of a spring, and the stroke length can be exactly executed regardless of the tolerances of the components. In contrast, the plunging of the bolt 2 into the weld puddle under spring pressure is dependent on the chain of tolerances. The impacting of the bolt 2 at high speed, the chain of tolerances, and the inaccurate and varying stroke length predetermined by the fixed stop, are all eliminated in the procedure according to the invention. As a result, exactly reproducible results can be achieved almost without any defective welds.
A further advantage of the device according to the invention and of the associated procedure is that, via the selection of parameters for the stroke length in the control system, a wide range of stroke lengths can be obtained with one and the same welding head, without having to make any mechanical adjustments. Other stroke lengths can be simply obtained by modifying the program. Therefore, with this device, a wide range of bolts 2 can be welded with one and the same welding head. All the advantages described are achieved through a combination of a drive unit for the bolt 2, a path-measuring system 10, also the control and regulating system for the movement parameters.
Summarizing, the following properties and improvements are offered:
freely programmable stroke length
freely programmable depth of plunge into the weld puddle
freely programmable acceleration, corresponding to the performance data of the actuator 11, for lifting and plunging
gentle plunging into the weld puddle is possible
movement and force sequences are independent of the welding position, i.e. equally good results can be obtained when welding upwards or downwards
compensation of the tolerances between the components or workpieces
bolts of all usual diameters can be handled
freely programmable speed sequences during the movement of the device
integration of all necessary movements into one stroke mechanism having a simple mechanical structure, small dimensions, and a low weight
the welding process and the quality of the welds can be influenced in a fully programmable manner via the software, without having to make any mechanical conversion
a wide range of bolts (diameters, lengths, shapes) can be welded with one and the same head
because no supporting foot or tripod is used, the bolts can be placed closer to any disruptive contours. | The device proposed is designed to weld together at least two parts (1, 2) using arc-welding or resistance-welding, in particular pressure arc-welding, techniques. An arc is struck across a gap between the two parts (1 and 2), thus causing them to melt. In oder to ensure a very precisely defined vertical gap between the parts, the second part (2) is first placed on the first. The final position, determined by a program-control unit (12), is measured by means of a travel-measurement instrument (10). Starting from this "zero position", the bolt is lifted through a freely programmable distance and the main welding current activated. On expiry of the prescribed period of time, the bolt on the second part (2) is moved towards the first part (1), this movement also being carried out under program control. | 1 |
This application in a continuation-in-part of copending application Ser. No. 08/575,565 which was filed on Dec. 20, 1995.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates, generally, to puller devices that pull tightly secured objects from their mounts. More particularly, it relates to a puller device that pulls golf club heads from golf club shafts.
2. Description of the Prior Art
Modern golf club shafts are made of graphite, graphite reinforced with boron, or fiberglass-reinforced products. Typically, the distal (leading) end of a shaft is axially received within the hosel of the golf club head and secured thereto by a thermoplastic adhesive means. Thus, when it is desired to change shafts, the hosel is heated to release the grip of the adhesive, and the shaft is manually pulled from the hosel.
The drawbacks of the just-described process are several. First of all, manual separation of the shaft and hosel usually twists and destroys the shaft because it is virtually impossible to maintain the required alignment of the shaft while pulling on it. Moreover, few people are strong enough to pull the shaft out until the adhesive has been greatly weakened by the application of a large amount of heat; as a result, the distal end of the shaft becomes hot before the separation of shaft and hosel can be accomplished and the shaft is ruined.
Many modern hosels are made of materials that discolor easily when heat is applied thereto. Thus, it is important to perform the hosel-pulling procedure in a minimum amount of time and at a minimum temperature.
Thus, there is a need for a pulling device that generates a very strong, non-twisting pulling force when a golf club shaft is pulled from a club head so that the shaft can be pulled from the hosel at a time when the temperature of the hosel has been elevated to a temperature sufficient to release the grip of the adhesive but insufficient to adversely affect the coloration of the hosel.
U.S. Pat. No. 2,160,395 to Wettlauffer discloses a golf shaft puller having a nut that is constrained against travel by a washer so that rotation of the nut causes the axial displacement of a sleeve-like body onto which the nut is threaded. The threaded sleeve thus acts as a drive rod that separates the golf club head from the golf club shaft. However, no means are provided to accomplish an abrupt separation of the shaft and head in a non-twisting manner at a low temperature and in a short amount of time.
Other U.S. patents of interest include U.S. Pat. Nos. 1,662,465; 2,991,080; 3,334,405; 4,179,125; 4,317,986; 3,891,212; 4,462,595; 4,674,747; 4,783,893; and UK patent No. 2,186,195. Many of the puller devices of the prior art relate to pulling steel shafts from hosels; the problems relating to shaft twisting and overheating are not encountered when a steel shaft is pulled.
The present inventor's earlier contribution to the art is described in U.S. Pat. No. 4,910,849 (1990). It enables separation of shaft and hosel without damage to the shaft, but the temperature required to accomplish the separation is quite high. Moreover, a bungee cord or similar restraining means is required to prevent the shaft from hurling itself across a room at the moment of separation. Perhaps more importantly, the earlier structure includes an elongate tube for ensleeving the shaft, and positioning of said elongate tube in said ensleeving relation requires removal of the hand grip from the shaft.
What is needed, then, is an improved structure that enables separation of the hosel and shaft at lower temperatures so that the hosel and shaft are subjected to less heat during the separation process. A need also exists for a shaft puller that does not require removal of the hand grip from the shaft being pulled, and which requires no restraining means for the shaft. Moreover, there is a need for a device that occupies less space than the shaft pullers heretofore known, and which generates more pulling power than the earlier shaft pullers.
However, in view of the prior art at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified needs could be fulfilled.
SUMMARY OF THE INVENTION
The present invention is a pulling device specially adapted to pull golf club heads from the shafts to which they are mounted. Significantly, the hand grip of the club need not be removed prior to use of the novel device, the separation of shaft and hosel occurs at a low temperature, and the shaft does not fly from the device at the moment of separation.
The novel device includes a rigid guide tube member that ensleeves a golf club shaft therein; the diameter of the guide tube is sufficient to enable its insertion over a hand grip so that the grip need not be removed prior to use of the novel tool.
A hosel push member is formed of two parts so that it may be positioned on the leading end of the golf club shaft. A leading end of the hosel push member is positioned in abutting relation to an annular shoulder formed by the juncture of the hosel and the golf club shaft, and a trailing end thereof is received within the leading end of the guide tube when the novel assembly is assembled. A radially outwardly extending flange demarcates the leading and trailing ends.
A drive means in the form of a coil spring (first embodiment) or a rigid (preferably steel) tube (second embodiment) ensleeves the guide tube, and a leading end of the drive means abuts the trailing side of the flange of the hosel push member. Accordingly, advancing the drive means in a trailing-to-leading direction applies pressure to the hosel push member and hence to the hosel.
In a first embodiment, the spring is compressed by a distance substantially equal to the depth of penetration of the shaft into the hosel. The hosel is then heated momentarily, and the spring unloads, driving the hosel off the shaft.
In a second embodiment, the drive means is advanced toward the hosel, thereby applying pressure to and displacing the steel drive tube. The hosel is then heated for just a moment, thereby loosening the adhesive. The heat is then removed and the hosel is pushed off by advancing the drive means by hand.
In both the first and second embodiments, the drive means is advanced in a trailing-to-leading direction by a drive means push member that screw threadedly engages the guide tube. A stop member is positioned in abutting relation to the trailing end of the guide tube to prevent rotation of said guide tube and to prevent leading-to-trailing displacement of said guide tube when the drive means push member is advanced.
In a third embodiment, an auxiliary stop member is positioned in abutting relation to the trailing end of the stop member of the first two embodiments to increase the slip resistance of the stop member of said first two embodiments. Moreover, a rod is added to the trailing end of the stop member of said first two embodiments and that rod is gripped by the auxiliary stop member so that the rotational resistance of the auxiliary stop member is transmitted to the primary stop member.
One or more radial bores are formed in the annular periphery of the drive means push member to facilitate its rotation, i.e., rotation of the push member is effected by inserting a rigid rod into a radial bore. Thus, no wrench is required to advance said push member in a trailing-to-leading direction. Alternatively, the drive means push member may be provided in the form of a large wrench-engageable nut. Advancing the push member in said trailing-to-leading direction compresses the bias means of the first embodiment or displaces the rigid steel tube of the second embodiment. Unlike the present inventor's earlier invention, the shaft is not abruptly displaced during or after the hosel removal procedure so no means are required to prevent it from flying from the workstation. Moreover, the novel arrangement disclosed in detail below provides a very high pushing/pulling force so that shaft-hosel separation occurs very quickly and at a very low temperature so that the new apparatus can be used even on hosels that discolor easily.
The primary object of this invention is to provide a device that separates club heads from golf club shafts of the glass, graphite or fiberglass type in the absence of damage to the shaft and discoloration of the hosel.
Another important object is to accomplish the foregoing object with a device that fits over club hand grips so that such grips need not be removed.
Still another object is to provide a shaft puller construction that generates three thousand pounds of pressure or more so that hosel-shaft separation occurs quickly and at a low temperature.
These and other important objects, advantages, and features of the invention will become clear as this description proceeds.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the description set forth hereinafter and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
FIG. 1 is a partially exploded perspective view of the parts of a first illustrative embodiment of the invention;
FIG. 2 is a partially exploded perspective view of the parts of a second illustrative embodiment;
FIG. 3 is a perspective view of the parts of a third embodiment in their assembled configuration, said third embodiment including the auxiliary stop member of this invention;
FIG. 3B is a perspective view depicting the trailing side of the primary stop member of the third embodiment;
FIG. 4 is a perspective view of the novel auxiliary stop member of the third embodiment in its open configuration to better disclose its structure;
FIG. 5 is a perspective view of the novel auxiliary stop member in its closed configuration; and
FIG. 6 is an end elevational view of the novel auxiliary stop member, with an arrow indicating how it is opened to its FIG. 4 configuration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, it will there be seen that an illustrative embodiment of the present invention is denoted by the reference numeral 10 as a whole.
The leading end of novel assembly 10 includes a two part hosel push member 12 having symmetrical parts 14 and 16. When assembled in sandwiching relation to club shaft 18, said parts collectively form a cylindrical leading part 20, a cylindrical trailing part 22, and a radially outwardly extending flange 24 therebetween. The leading edge 19 of leading part 20 abuts shoulder 26 (FIG. 3) formed by the juncture of hosel 28 and shaft 18 when the novel apparatus is in use.
Guide tube 30 has an inner diameter sufficient to permit it to ensleeve shaft 18 and hand grip 32 (FIG. 3), i.e., it fits over said hand grip when the novel device is to be used. Leading end 34 (FIG. 1) of guide tube 30 abuts trailing side 36 of flange 24 of hosel push member 12 when the novel apparatus is in its assembled configuration.
Guide tube 30 is externally threaded substantially along most of its extent as at 38, and an internally threaded disc-shaped drive means push member 40 screwthreadedly engages said guide tube so that rotation of said drive means push member 40 in a clockwise direction advances it in a trailing-to-leading direction along the threaded extent of said guide tuber and opposite rotation displaces it in a leading-to-trailing direction.
One or more radial bores, collectively denoted 42, are formed in the periphery of drive means push member 40 in equidistantly and circumferentially spaced relation to one another; one or more rigid rods 44 are selectively placed in one or more of said bores and rotated about a longitudinal axis of the shaft to rotate the disc member in a desired direction to advance or retract it along the extent of said guide tube. In this way, no wrench is required to displace said disc-shaped drive means push member 40. However, as indicated in FIG. 2 (second embodiment), a wrench-engageable conventional nut 41 could be used in lieu of said disc member 40.
In the first embodiment, a drive means in the form of a coil spring 46 ensleeves guide tube 30 and the leading and trailing ends of said spring abut trailing side 36 of flange 24 and leading side 48 of drive means push member 40.
In the second embodiment of FIG. 2, the drive means is provided in the form of a rigid, preferably steel drive tube 50 which supplants said coil spring 46. In either embodiment, advancing drive means push member 40, i.e., displacing it (or nut 41) in a trailing-to-leading direction as indicated by directional arrow 52, drives hosel 28 from shaft 18 when said hosel is thereafter heated to loosen the thermoplastic adhesive that secures it to said shaft, i.e., the hosel is pre-loaded before it is heated. This enables a very brief period of heat application.
It will be observed that guide tube 30 will rotate about its longitudinal axis as drive means push member 40 (or 41) advances, unless means are provided to prevent such rotation. The novel anti-rotation means is provided in the form of a two part, preferably steel stop member 54 that is secured to shaft 18 in abutting relation to trailing end 56 of guide tube 30. When assembled in sandwiching relation to shaft 18, part 60 of stop member 54 includes a semi-annular member 62 that is received within the trailing end 56 of guide tube 30. Alternatively, said semi-annular member 62 could extend in a leading direction from part 58. An anti-rotation post 64 extends in radial relation from semi-annular member 62 and extends through anti-rotation slot 66 formed in said guide tube trailing end 56. Thus, when stop member 54 is secured to shaft 18 and held in a vice or other suitable gripping means, guide tube 30 cannot rotate relative to stop member 54, i.e., said guide tube 30 cannot rotate about its longitudinal axis when disc member 40 is rotated, nor can said guide tube displace in a leading-to-trailing direction. Accordingly, advancing said drive means push member 40 or 41 compresses coil spring 46 or applies pressure to steel drive tube 50 and hosel 28 is pushed off shaft 18, i.e., shaft 18 is pulled from hosel 28, when heat is applied to said hosel.
The means for securing stop member 54 to shaft 18 includes rubber pads, collectively denoted 68, that are positioned within respective tapered shaft-receiving channels formed in said stop member parts 58, 60. The pads prevent marring of the shaft by primary stop member 54 when the stop member is tightly secured to said shaft, and said pads also provide a strong frictional grip of said shaft to prevent rotation thereof. Stop member 54 is gripped by a table-mounted vice, not shown, when device 10 is in use.
The means for securing stop member 54 to shaft 18 further includes a pair of externally threaded bolts, collectively denoted 70. An internally threaded bore for screwthreadedly engaging said bolts is formed in primary stop member base parts 58, 60. Alternatively, a smooth bore is formed in the half part abutted by the respective heads of the bolts and an internally threaded bore is formed in the other half.
Stop member 54 thus not only prevents rotation of guide tube 30 with respect to shaft 18, it also prevents leading-to-trailing displacement of said guide tube as drive means push member 40 is advanced in a trailing-to-leading direction.
Significantly, as perhaps best understood in connection with FIG. 2, stop member 54 is positioned on shaft 18 at a point where said shaft is quite thick and thus quite strong, i.e., at a location remote from its thin, weak leading end.
About three thousand pounds of force is generated by advancing said drive means push member when the drive means is steel tube 50; therefore, the amount of heat that needs to be applied to said hosel when the novel apparatus is used is less than the amount required by shaft pullers heretofore known. Such reduction of temperature reduces the probability of damage to the shaft or discoloration of the hosel during the shaft-hosel separation procedure.
The ability to slide the novel apparatus over the hand grip 32 of shaft 18 reduces the amount of time required to perform the shaft-replacement job as well.
The quantity of material required to make the novel apparatus is considerably less than the quantity of material required for earlier shaft pullers. Thus, the apparatus occupies less space, is easier to store when not in use, and is easier to use when in use.
Steel tube drive means 50 is used when a stronger pull is required, but coil spring drive means 46 also performs well. Use of either drive means is safe because the shaft will not fly from the hosel at the moment of disengagement. Thus, no means are needed to restrain the shaft.
In a third embodiment, depicted in FIG. 3, steel tube 50 is employed to the exclusion of coil spring 46, as in the second embodiment. An auxiliary stop member in the form of shaft-gripping member 80 is disposed in abutting relation to the trailing end of primary stop member 54. As best understood in connection with FIGS. 4-6, member 80 includes opposed flat metallic outer surfaces 82 and opposed elastomeric inner pads 84 having tapered grooves 86 formed therein. Pads 84, preferably, have a 65-95 Durometer A hardness rating. Note that auxiliary stop member 80 has a longitudinal extent two or three times greater than the longitudinal extent of primary stop member 54. Thus, member 80 adds considerable shaft-gripping strenth; it virtually insures that primary stop member 54 will not slip in a leading-to-trailing direction when drive means push member 40 is rotated.
The taper of grooves 86 matches the taper of shaft 18.
A conventional table-mounted vice, not shown, is used to grip opposed outer surfaces 82. Thus, the vice prevents rotation of auxiliary shaft-gripping member 80 during rotation of disc member 40 or nut 41.
As best understood in connection with FIG. 3B, an additional anti-rotation means in the form of a rod 88 is secured to the trailing end of primary stop member 54, in substantially parallel relation to shaft 18, so that said rod is positioned in sandwiched relation between opposed elastomeric pads 84. In this manner, additional rotational resistance is applied to primary stop member 54, i.e., with auxiliary stop member 80 being held against rotation by a table-mounted vice, rod 88, in effect, transmits such rotational resistance to primary stop member 54.
The auxiliary stop member increases the effective surface contact area between the shaft and the primary stop member and reduces the surface pressure on the shaft that must be supplied by the primary stop member. Thus, the use of both the primary and the auxiliary stop members enables use of the novel device on very tender shafts, i.e., such stop members distribute the pounds of pressure applied to the shaft over a larger area, thereby reducing the surface pressure applied to any particular point while increasing the overall pressure or shaft-gripping power applied to prevent guide tube slippage. The result is the ability to apply an even greater hosel removal force at even lower temperatures relative to the removal force and temperatures of the first and second embodiments.
With the extra anti-slip and anti-rotational grip provided by auxiliary stop member 80 and rod 88, any clubhead (except aluminum) is removable in about fifteen seconds upon rotation of disc member 40 or nut 41, with little or no heat applied to the hosel.
It will thus be seen that the objects set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
Now that the invention has been described: | An apparatus that separates a golf club head and a golf club shaft to which it is adhesively secured. A hosel push member is positioned in abutting relation to the hosel of the club head. An externally threaded guide tube is slideably inserted over the hand grip of a golf club shaft and is positioned in trailing relation to the hosel push member. A drive member in the form of a coil spring or a rigid tube is ensleeved around the guide tube, and a drive member push member screw threadedly engages the threads on the guide tube so that advancement of the drive member push member applies pressure upon the drive member. Primary and auxiliary stop members grip the shaft on the trailing end of the guide tube to prevent rotation and slippage of the guide tube. Heating the hosel after application of pressure onto the drive member weakens the adhesive and results in separation of the club head from the shaft. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to the provision of connections between circuit cards and cables and, more particularly, to such provision through a backplane in a high density application.
Modern electronic systems equipment, such as for telecommunications purposes, is often constructed as modular circuit cards inserted into guide slots of mechanical card cages for engagement with connectors on a first side of a main backplane mounted to the card cage at the inward ends of the guide slots. For telecommunications equipment, the second side of the main backplane is typically provided with connectors to which cables may be attached. The main backplane provides interconnections between the connectors on its first and second sides.
In a particular application, it is required to interconnect sixteen circuit cards to 192 cables, with each circuit card having four individual connections to each cable. This results in a total of 12,288 interconnections which must be made between the connectors for the circuit cards and the connectors for the cables. Modern backplanes are composed of multiple layers, with each layer accommodating a number of circuit paths. Current backplane manufacturing imposes a set of limits on backplane designs including the thickness of the backplane and the resulting layer count. At the present time, most manufacturers can only produce a 400 mil thick backplane which would limit layer count to about sixty-four, with twenty-eight signal layers available for routing. Such a backplane is insufficient for accommodating the 12,288 interconnections required in the particular application.
Accordingly, there exists a need for a high density cross-connection system which can accommodate the desired number of interconnections.
SUMMARY OF THE INVENTION
According to the present invention, groups of related circuit paths which connect to the same physical area of a group of circuit cards are routed on secondary backplane boards connected to the main backplane board. The cables are connected to the secondary backplane boards and the remaining number of circuit paths required to be routed on the main backplane board falls within manufacturing limits.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing will be more readily apparent upon reading the following description in conjunction with the drawings in which like elements in different figures thereof are identified by the same reference numeral and wherein:
FIG. 1 schematically depicts the first side of a main backplane board according to this invention, showing how a plurality of circuit cards are connected thereto;
FIG. 2 schematically depicts the second side of the main backplane board shown in FIG. 1 and the connections thereto of a plurality of secondary backplane boards, and showing the connection of a cable to a secondary backplane board;
FIG. 3 is a schematic side view illustrating the inventive routing of interconnections from a circuit card to the secondary backplane boards;
FIG. 4 illustrates cross-connection circuit paths on a typical layer of the main backplane board according to this invention; and
FIG. 5 illustrates cross-connection circuit paths on a typical layer of a secondary backplane board according to this invention.
DETAILED DESCRIPTION
FIG. 1 shows a main backplane board 10 and a plurality of circuit cards 12. Each of the circuit cards 12 has a connector array 14 mounted to its leading edge and the main backplane board 10 has an array of card connectors 16 on a first side 18. As is conventional, the connectors 14, 16 comprise pin field arrays. The card connectors 16 are adapted for mating engagement with the connector arrays 14 of the circuit cards 12 to hold the circuit cards 12 in a parallel spaced array. Illustratively, the circuit cards 12 are held in a vertical orientation.
As shown in FIG. 2, a plurality of secondary connectors 22 are mounted on the second side 20 of the main backplane board 10. The secondary connectors 22 are arranged in a plurality of groups, illustratively six in number, with each group extending horizontally.
According to the present invention, a plurality of secondary backplane boards 24 are provided, illustratively six in number, each corresponding to one of the groups of secondary connectors 22. Each of the secondary backplane boards 24 has a first side 26 (FIG. 3) on which is mounted a plurality of connectors 28 adapted for mating engagement with the respective group of secondary connectors 22. On the second side 30 of each of the secondary backplane boards 24, there is mounted a plurality of connectors 32 each of which is adapted for mating engagement with a connector 34 terminating a respective cable 36.
FIG. 3 illustrates the inventive routing of connections between the connector arrays 14 on the circuit cards 12 and the secondary backplane boards 24. As shown in FIG. 3, there is insufficient room for all the secondary backplane boards 24 to be directly across the main backplane board 10 from the card-connectors 16. Accordingly, each card connector 16 has three portions, each corresponding to a respective one of the secondary backplane boards 24. The three portions include a central portion and two outer portions flanking the central portion in the vertical direction. The secondary connectors 22 are divided into groups with each secondary connector 22 in a first group being directly across the main backplane board 10 from a first outer portion of a respective card connector 16 and each secondary connector 22 in a second group being directly across the main backplane board 10 from a second outer portion of a respective card connector 16. Each secondary connector 22 in the third group is on the other side of the secondary connector 22 in the second group from the secondairy connector 22 in the first group in the vertical direction.
The main backplane board 10 therefore includes circuit paths 38 which go straight through the main backplane board 10 to interconnect opposing ones of the card connectors 16 with the respective secondary connectors 22. Further, the main backplane board 10 includes circuit paths 40 which interconnect the central portion of a respective card connector 16 with a respective secondary connector 22 in the third group of secondary connectors. As shown in FIG. 4, the circuit paths 40 are substantially vertically oriented through the main backplane board 10. Since all of the circuit paths 40 are substantially in the same direction, they can all be accommodated within the main backplane board 10.
To provide interconnections in the horizontal direction across the plurality of circuit cards 12, circuit paths 42 (FIG. 5) are provided on the secondary backplane boards 24. As shown in FIG. 5, the circuit paths 42 extend substantially horizontally.
In summary, for the application described above, each of the secondary backplane boards 24 routes 2048 interconnections and the main backplane board 10 is only required to route 4096 interconnections (along with approximately 2000 adjunct control interconnections not described herein). Thus, each of the secondary backplane boards 24 can be manufactured with forty-two layers and the main backplane board 10 can be manufactured with forty-six layers, well within current manufacturing capability.
While the foregoing discussion has used the directional terms "vertical" and "horizontal", it will be appreciated that these particular directional terms are for illustrative purposes only. What is contemplated by the present invention is that the cross-connection circuit paths are divided between the main backplane board and the secondary backplane boards, with the main backplane board having circuit paths substantially in a first direction aligned with the circuit cards and the secondary backplane boards having circuit paths substantially in a second direction at a right angle to the first direction (i.e., across all the circuit cards).
Accordingly, there has been disclosed an improved high density cross-connection system. While an illustrative embodiment of the present invention has been disclosed herein, it is understood that various adaptations and modifications to the disclosed embodiment are possible and it is intended that this invention be limited only by the scope of the appended claims. | Secondary backplane boards are secured to a main backplane board to provide interconnection paths in a direction transverse to interconnection paths provided on the main backplane board, so that current manufacturing capabilities of multi-layer backplane boards are not exceeded. | 7 |
FIELD OF THE INVENTION
This invention relates to new compositions of matter, and more particularly to coating compositions for application to a substrate to promote adhesion of a room temperature vulcanizable (RTV) silicone rubber coating. The invention relates with greater particularity to the protection of aquatic surfaces from the fouling effects of such an environment and to preclude contamination of the environment by the coating compositions.
BACKGROUND OF THE INVENTION
Man-made structures such as watercraft hulls, power station cooling water inlets and outlets, buoys, oil drilling rigs and all manner of surfaces immersed or splashed by fresh and/or sea water are prone to fouling by aquatic organisms such as barnacles, mussels, green and brown algae and the like. The fouling caused by organisms adhering on mobile structures such as watercraft hulls impedes the movement of the craft through the water. Static structure fouling hampers inspection and modification, in addition to having untold effects on the wave energy absorption by the structure. Piping systems become narrowed through accumulation of organisms with the result of reduced flow rates and increased wear on pumping equipment.
To combat fouling, considerable attention has been directed to the development of improved RTV silicone rubber compositions. Ideally, an RTV is stable for an indefinite period when stored in the absence of moisture, and rapidly cures to a tack-free coating upon exposure to moisture. A problem typically associated with RTV silicone rubber coatings is the difficulty in making them adhere well to substrates. This problem is discussed in European Patent Application 16195, which proposes applying the RTV silicone rubber as a cladding on a fabric backing. This method necessarily introduces additional complexity associated with rubber application to the backing and smoothing the backing onto the substrate.
An alternative approach involves the various primer compositions applied to the substrate as an undercoating for an RTV silicone rubber. Such primers have included a cross-linkable silicone paste (U.S. Pat. No. 3,702,778). Primers have also been devised using mixtures of epoxy-silane and an alkene-containing silane, polyurethanes, various rubbers, aminosilane-containing silicone resins and chlorinated polyethylene for a limited class of surfaces.
The commercially most successful primers for RTV silicone foul-release rubber contain substances toxic to aquatic organisms. The metal containing catalysts necessary for curing of such primers is typically a source of such toxins. Because of the leaching of toxins from such coatings, otherwise useful primers are increasingly being regarded with disfavor. As a result, a need exists for a primer which does not contain markedly toxic materials.
Prior art primer compositions have relied on metal containing catalysts and in particular tin-based catalysts such as dibutyltin dilaurate and tributyltin chloride to speed the cure of a primer. U.S. Pat. No. 5,290,601 is a representative example of such a composition. The concentration of a metal-containing catalyst is a result of a compromise between pot life of the mixed material and the curing time of the coating once applied. Thus, the higher the catalyst concentration the shorter the pot life with an ensuing increase in cure rate. Conversely, low catalyst concentration may result in the cure reaction being incomplete and resulting in a high-tack, low molecular weight primer with unacceptable material properties.
A stop gap solution to obtain long pot life, fast cure times and avoid undue contact with undesirable metal catalysts, especially those containing tin, has involved separate packaging of the catalyst material. The net result of which being additional handling procedures.
DETAILED DESCRIPTION OF THE INVENTION
Thus, there exists a need for a primer composition adapted for the adherence of numerous types of RTV silicone rubbers, which has comparable pot life and cure rates at room temperature to prior art primers, but without the need for a catalyst therein. In one of its aspects, the present invention includes compositions resulting from the hydrolysis of a room temperature curable polydiorganosiloxane of the following formula in the presence of other hydroxyl functional groups: ##STR1## where R 3 can be the same or different R monovalent hydrocarbon radicals having 1 to 12 carbon atoms. R 3 is contained within the repeating unit of (I). Preferably, R 3 is an aliphatic radical. More preferably, R 3 is the same radical in both occurrences of Formula (I). Still more preferably R 3 is alkyl and illustratively: methyl, ethyl, hexyl or octyl. It is appreciated that aromatic, heterocyclic and substituted hydrocarbon radicals are also operative as R 3 . R 1 radicals are preferably alkyl, for example methyl, ethyl, hexyl or octyl, alkenyl, for example, vinyl; aryl, for example phenyl; or aralkyl, for example benzyl. R 2 is such that O--R 2 is a(n): oximino, benzamido, acetoxy, or alkoxyl radical. Preferably, R 2 is chosen such that upon hydrolysis of the diorganopolysiloxane of Formula (I), O--R 2 forms a volatile compound. Thus, R 2 optionally contains less than 10 aliphatic carbon atoms. R 2 is contained within the terminal unit of (I). It is appreciated that mixtures of two or more room temperature curable polydiorganosiloxanes of Formula (I) may be used, if so desired.
The polydiorganosiloxane (I) is preferably used as such in the primer composition. However, it is appreciated that it is optionally replaced wholly or in part by a polyhydro-organosiloxane or the like. A polyhydro-organosiloxane has less reactive hydroxyl groups, as compared to a room temperature curable polydiorganosiloxane (I) and as such has different material properties upon cure. Furthermore, it is appreciated that curable functional groups --OR 2 which are shown as terminal groups in (I) are readily replaced by siloxanes having pendent curable functional groups.
The room temperature curable polydiorganosiloxane (I) is preferably a polydiorganosiloxane having sufficient repeating units so as to attain a viscosity of between 500 and 1 million centistokes at 25° C. The polydiorganosiloxane (I) is preferably produced by the reaction of a hydroxy terminated polydiorganosiloxane, ##STR2## with a silane as shown below:
R.sup.1 --Si--(--OR.sup.2).sub.3 (III)
The radicals R 3 , R 1 and R 2 are those described above in regard to Formula (I). Preferably, n (the repeat unit number) is chosen such that the viscosity of (II) is between 500 and about 1 million centistokes at 25° C. The reaction of a hydroxy-terminated polydiorganosiloxane of Formula (II) and a silane (III) occurs preferably under an inert atmosphere. Illustratively, an inert atmosphere consists of dry nitrogen, argon, or helium. The reaction of a hydroxy-terminated polydiorganosiloxane (II) and a silane (III) requires a stoichiometric ratio between II:III of at least 1:2. However, since the reaction of II and III is irreversible and its reaction product is highly moisture-sensitive, it is preferred that an excess of silane (III) is present relative to hydroxy terminated polydiorganosiloxane (II). Such an excess of silane assures shelf life stability of the room temperature-curable polydiorganosiloxane (I) under dry conditions.
The pot life and cure rate of the primer coating compositions of the instant invention is preferably controlled through the selection of a silane (III). While the identity of R 2 has a significant effect on the polarizability of a silane Si--O bond, the reactivity of R 1 has a more pronounced effect on the pot life and cure rate of the resulting coating composition. For example, vinyloximinosilane when utilized as a silane (III) generates a rapidly curing room temperature curable polydiorganosiloxane (I) when reacted with moisture. As a result, compositions of Formula (I) wherein R 1 is uniformly vinyl and R 2 is oximino, have a short pot life. In contrast, methyloximinosilane exclusively incorporated into a composition of Formula (I) wherein R 1 is uniformly methyl and R 2 is oximino is characterized by a slow curing reaction and a long pot life as compared to conventional primer compositions. Thus, in embodiments of the instant invention wherein silane (III) is an oximinosilane, it is preferred that R 1 be a mixture of methyl and vinyl radicals. More preferably, methyl and vinyl radicals constitute R 1 at a molar ratio of from 0:5 to 2:1, inclusive within (I).
Either during or subsequent to the reaction of a hydroxy terminated polydiorganosiloxane (II) and a silane (III) a variety of additives are optionally mixed into the reaction vessel. The additives illustratively include adhesion promoters such as aminosilanes, chlorinated polyolefins, and a variety of functionalized silanes; pigments, such as TiO 2 and iron oxide, and others as is known in the art; mineral fillers, such as surface-treated calcium metasilicate, mica and silica, and others as is known in the art; thixotropic agents; stabilizers, surfactants; anti-oxidants and plasticizers, as well as other additives, as is known in the art. A functionalized silane is defined herein as a silane having a moiety bonded thereto which is reactive, the moiety containing a heteroatom and/or a pi-bond therein. Optionally, pigments are included in the primer coating compositions of the instant invention so that upon being overcoated by a fouling release layer of clear RTV silicone rubber, the pigment is visible. When incorporating pigments or other additives, it is necessary to take precautionary steps to avoid any moisture from initiating premature curing of the room temperature curable polydiorganosiloxane (I). Optionally, the additive may also be a desiccant, included to scavenge trace moisture in the reaction vessel. The desiccant serving to lessen premature curing of the room temperature curable polydiorganosiloxane (I). The simplest precaution is to ensure that any additive used is thoroughly dry. Alternatively, the additives and pigments may be dispersed in a chemically compatible dilutant, preferably a polydiorganosiloxane. The additive is, for example, dispersed in a polydiorganosiloxane such as polydimethylsiloxane.
The primer compositions of the instant invention optionally contain an organic dilutant which for example is an aliphatic, cycloaliphatic or aromatic hydrocarbon (which can be optionally halogenated) such as n-heptane, n-octane, cyclohexane, methylcyclohexane, toluene, xylene, mesitylene, cumene, tetrahydronaphthalene, perchloroethylene, trichloroethane, tetrachloroethane, chlorobenzene or orthodichlorobenzene, an aliphatic or cycloaliphatic ketone such as methylethyl ketone, methylisobutyl ketone, methylisoamyl ketone, cyclohexanone or isophorone; an ether such as dialkyl ether of ethylene glycol or propylene glycol, or an ester such as ethylacetate, butylacetate or ethoxyethyl acetate. The weight ratio of dilutant to room temperature curable polydiorganosiloxane (I) is usually 1:50 to 20:1, preferably 1:10 to 3:1.
The primer compositions of the instant invention are particularly effective in promoting adhesion to organic resin substrates and metals. Such organic resin substrates illustratively include neoprene rubber, chlorinated rubber, block copolymer rubbers such as polystyrene/polybutadiene or polystyrene/poly(ethylene-butylene) rubbers, polyurethanes, epoxy coatings, vinyl coatings such as vinylchloride polymers or alkyd resins. These resins are typically found in the form of cladding in the case of neoprene and similar rubbers or may be present as previously applied coatings which are now to be covered by an RTV silicone rubber. The primer compositions of the instant invention are similarly well suited to promote adhesion to aluminum and steel.
The primer compositions of the instant invention are applied to a substrate by any known conventional coating technique. Typically the primer of the instant invention is applied by spray, brush or roller techniques.
The RTV silicone rubber fouling-release coating which is applied over the primer composition of the instant invention can, but does not have to be based on a polydiorganosiloxane terminating in silicon-bonded hydrolyzable groups as described above and illustratively included silicon-bonded ketiminoxy or acyloxy groups. For most applications it is preferred that the silane (III) or silicon bonded hydrolyzable groups (O--R 2 ) in the room temperature curable diorganopolysiloxane (I) of the primer composition or silicon bonded hydrolyzable groups in the RTV silicone rubber are the same. The RTV silicone rubber coating preferably includes a nonreactive silicone oil, for example of the formula Q 3 Si--O--(SiQ 2 --O--) j SiQ 3 , where each group Q represents a hydrocarbon radical having from 1 to 10 carbon atoms and j is an integer such that the silicone oil has a viscosity of 20 to 5,000 m Pa s. At least 10% of the groups Q are generally methyl groups and at least 2% of the groups Q are preferably phenyl groups. Most preferably, at least 25% of the --SiQ 2 --O-- units are methylphenylsiloxane units. Most preferably, the nonreactive silicone oil is a methyl terminated poly(-methylphenylsiloxane). The oil preferably has a viscosity of 20 to 1,000 m Pa s and is preferably used at 1 to 50%, most preferably 2 to 20% by weight based on the RTV silicone rubber. An example of the preferred nonreactive silicone oil is sold under the name RHODORSIL HUILE 550. The nonreactive silicone oil improves the resistance of the composition to aquatic fouling.
In place of or in addition to the nonreactive silicone oil, the RTV silicone rubber composition optionally contains a nonreactive fluid organic hydrocarbon, for example a lubricating mineral oil such as white oil, a low molecular weight polybutene or petrolatum or liquid paraffin/petrolatum mixture. Such a nonreactive fluid organic hydrocarbon is preferably absent from the primer composition.
A primer composition of the instant invention improves the overall adhesion of an RTV silicone rubber to a substrate to a greater extent than is achieved in its absence. The room temperature curable polydiorganosiloxane (I) tends to limit the absorption of the primer composition into the substrate, allowing a lag time of, for example, up to a week or even longer in which the overcoating with an RTV silicone rubber compound is achieved with good adhesion.
In order to form the primer coating compositions of the instant invention, the room temperature curable polydiorganosiloxane (I) is applied to the substrate in the presence of water. Typically atmospheric moisture is sufficient to hydrolyze the compound of Formula (I) so as to form reactive hydroxyl groups as shown in Formula (IV): ##STR3## The reactive hydroxyl groups of the polysiloxane (IV) undergo a condensation chain extension reaction in the presence of other hydroxyl sites. Sources of condensation chain extension functional groups illustratively include adhesion promoters, pigments, mineral fillers and the like mixed with the room temperature curable polydiorganosiloxane (I); molecules created in situ as a result of the reaction of species (II) and (III) and/or those involving the aforementioned additives; and other hydroxy containing molecules mixed with the room temperature curable polydiorganosiloxane (I) prior to application to the substrate. These other molecules added prior to application to the substrate illustratively include silanols, organic acids, alcohols and hydroxy terminated siloxanes. Preferably, the functional group is a hydroxyl. More preferably, the added molecules capable of chain extension condensation reaction with the siloxane (IV) is a hydroxy terminated polydiorganosiloxane, as shown in Formula (II) in the form of a base component composition. Still more preferably, hydroxy terminated polydimethylsiloxane is used. The repeat unit of the hydroxy terminated polydimethylsiloxane being of a large enough number such that the viscosity is between 500 and 1 million centistokes at 25° C. It is appreciated that the various additives mixed with room temperature curable polydiorganosiloxane (I) are also suitable for mixing with the base composition. The functional groups may be either pendant or terminal. The invention is further illustrated by the following examples in which parts and percentages are by weight. The description of particular embodiments is not intended to limit the invention to the specific embodiments, but rather to illustrate the breadth of alternatives, modifications and equivalents that may be included within the scope as defined in the appended claims.
EXAMPLE 1
A reactive room temperature moisture curable catalyst free polydiorganosiloxane is created by blending 57.7 parts by weight of a hydroxy-terminated polydimethylsiloxane having a viscosity of 3500 centistokes at 25° C. (RHODORSIL 48V3500 from Rhone-Poulenc), 6.4 parts by weight of a hydroxy-terminated polydimethylsiloxane having a viscosity of 20,000 centistokes at 25° C. (Elastomer 20N, from Wacker), and 7.6 parts by weight of xylene.
The above blend is mixed at least for 5 minutes. Followed by the addition of 1.3 parts by weight of N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane (aminosilane, DYNASYLAN DAMO-T from Huls) and 1.3 parts by weight of an organomodified siloxane (silane, SILQUEST Y-11343 from WITCO Corporation/OSI Specialties Group). These two silanes (adhesion promoters) are preferably premixed before blending them with the above hydroxy-terminated polydimethylsiloxane polymers. 3.2 parts by weight of xylene are further added to the blend and mixed.
4.3 parts by weight of vinyloximinosilane (OS-2000 from Allied Signal) and 4.3 parts of methyloximinosilane (OS-1000 from Allied Signal) are then added to the above blend. However, the two oximinosilanes are preferably premixed prior to adding them in the above blend.
14.0 parts by weight of xylene are further added to the blend which is then further mixed.
The formulation is mixed under an atmosphere of dry nitrogen at 25° C. No catalyst is added to the formulation. This formulation has a shelf life stability greater than two weeks when properly sealed and stored at 40° F. to 90° F.
Upon application of the formulation to a clean suitable substrate, a clear primer coating composition resulted that is cured and amenable to overcoating with a RTV silicon rubber.
EXAMPLE 2
The same as Example 1 except that the order of addition is changed such that vinyloximinosilane/methyloximino silane (OS-2000/OS-1000) is added BEFORE the addition of the aminosilane/organomodified siloxane (DAMO-T/Y-11343).
EXAMPLE 3
The same as Example 1 except that 64.1 parts by weight of RHODORSIL 48V3500 are mixed into the blend with no Elastomer 20N being present.
EXAMPLE 4
The same as Example 1 except that 64.1 parts by weight of Elastomer 20N are mixed into the blend with no RHODORSIL 48V3500 being present.
EXAMPLE 5
As Example 1 except that 6.4 parts by weight of a hydroxy-terminated polydimethylsiloxane having a viscosity of 50000 centistokes at 25° C. (Elastomer 50N from Wacker) is substituted for the Elastomer 20N of Example 1.
EXAMPLE 6
Although the formulation of Example 1 can be used as a catalyst free clear primer coating composition, it also represents a reactor pack of a two pack catalyst free pigmented and colored primer coating composition. The formulation of Example 1 is mixed with an equal volume of a base pack component prior to the application on a suitable substrate. The base pack containing 22.3 parts by weight of RHODORSIL 48V3500 and 4.4 parts by weight of Elastomer 20N. 46.1 parts by weight of coloring and reinforcing pigments are then dispersed in the silicon polymers using also 1.1 parts by weight of a dispersing aid (Anti-Terra U from BYK CHEMIE). During the process, a total of 22.6 parts by weight of xylene is used to facilitate the manufacture of this product.
Finally, 3.6 parts by weight of a chlorinated polyolefin (adhesion promoter, CPO-515-2 from Eastman Chemical) is also added to the base pack formulation.
The base pack formulation is manufactured under an atmosphere of dry nitrogen at 25° C. The base pack has a shelf life stability of at least two weeks when properly sealed and stored at 40° F.-90° F.
Upon homogenizing the base pack with the reactor pack and application to a suitable substrate, a cure results without the presence of a catalyst to form a colored and pigmented primer coating composition amenable to overcoating with an RTV silicone rubber.
EXAMPLE 7
The reactor and base packs of Examples 1 and 6, respectively, are blended together under at atmosphere of nitrogen at 25° C. Thus creating a one pack pigmented reactive room temperature moisture curable catalyst free primer coating composition.
This one pack primer coating composition has a shelf life stability of at least two weeks when properly sealed and stored at 40° F.-90° F.
Upon application of this one pack primer coating composition to a clean suitable substrate, a cure results without the presence of a catalyst and amenable to overcoating with an RTV silicon rubber.
EXAMPLE 8
A reactive room temperature moisture curable catalyst free primer coating composition is created by blending 88 parts by weight of a mixture of hydroxy-terminated polydimethylsiloxanes having a viscosity of 3000-30,000 centistokes at 25° C. (80 parts RHODORSIL 48V3500 and 8 parts Elastomer 20N) with 6 parts by weight vinyloximinosilane (OS-2000) and 6 parts by weight methyloximinosilane (OS-1000). No catalyst is added to the formulation. The formulation is mixed in the absence of atmospheric moisture and under an atmosphere of dry nitrogen at 25° C. The formulation had a shelf life stability of greater than two weeks.
EXAMPLE 9
The above reactor formulation represents a reactor pack of a two pack catalyst free primer coating composition. The reactor formulation is mixed with an equal volume of a base pack component. The base pack containing a mixture of 80 parts 48V3500, 16 parts by weight Elastomer 20N, and 4 parts by weight of a chlorinated polyolefin (CPO-515-2 from Eastman Chemical). Upon homogenizing the base pack with the reactor pack and application to a neoprene rubber pipe segment, a cure results without the presence of a catalyst cure to form a primer coating composition amenable to overcoating with an RTV silicone rubber.
Upon application of the formulation to a clean aluminum substrate by roller application, a primer coating composition resulted that is tack free and amenable to overcoating with an RTV silicone rubber.
Modification 1
1.1 parts by weight of an aminosilane (DAMO-T from Huls) and 1I.1 parts by weight of a silane (Y-11343 from OSI) are incorporated into the formulation of the reactor pack, in place of a similar number of parts of 48V3500. This modified reactor formulation is homogenized with the base pack and applied to a steel substrate. Upon cure in the presence of atmospheric moisture, a primer coating composition results which is amenable to overcoating with an RTV silicone rubber.
Modification 2
A dry pigment of titanium dioxide is dispersed in the base mixture of Example 9 at 2 parts by weight, in place of a similar number of parts of 48V3500.
Modification 3
The hydroxy-terminated polydimethylsiloxane of the reactor pack is replaced with a hydroxy terminated polydimethylsiloxane having a viscosity of about 20,000 centistokes (20N from Wacker).
Modification 4
The hydroxy-terminated polydimethylsiloxane contained within the base mixture is replaced with a hydroxy-terminated polydimethylsiloxane having a viscosity of 20,000 centistokes (20N).
Various modifications of the instant invention in addition to those shown and described therein will be apparent to those skilled in the art from the above description. Such modifications are also intended to fall within the scope of the appended claims. | Polydiorganosiloxane or polyhydroorganosiloxane compositions are prepared which are room-temperature curable without the presence of a catalyst and in particular an organotin catalyst. The compositions are useful as primer coating compositions to promote adhesion of room temperature vulcanizable (RTV) silicone rubber coatings, especially those RTVs containing polydiorganosiloxanes. | 2 |
BACKGROUND OF THE INVENTION
This invention pertains to the field of optical sensors or detectors generally and, in particular to that class of optical sensors which are non-imaging. Specifically, it pertains to techniques for controlling the field-of-view of a non-imaging optical sensor or detector.
Traditional methods for controlling the field-of-view of an optical sensor or detector involve complex arrangements or lenses or field stops. One approach is to design a lens with three or more elements, whose relative positions are adjusted to affect a change in the focal length of the lens, and hence the field of view. Another approach is to design a lens having a constant focal length, placing a variable aperture at the focal plane of the lens to serve as a field stop. Both of these approaches encounter practical difficulties for a large field-of-view. When the field-of-view exceeds 60° full angle, the physcial aperture of the lens exceeds the pupil, or optical aperture, of the sensor. For example, a lens system with a 190° field-of-view with a pupil of ten inches (10") would be twenty-one feet (21') in diameter and sixty feet (60') long.
There is a class of optical applications that does not require the use of imaging detectors or sensors. A laser communications system using an atomic resonance filter (ARF) is an example of non-imaging optical system. The atomic resonance filter (ARF), comprised of vapors of specific atoms, has been developed recently as a new type of narrow band optical filter. (Cf. "Atomic resonance filers", Jerry A. Gelbwachs, IEEE Journal of Quantum Electronics, Vol. 24, No. 7, July 1988, and U.S. Pat No. 4,829,597). The atomic resonance filter is an optical filter which does not preserve the optical coherence of the incoming light and, consequently, all imaging qualities are lost in such a filter. Thus, there is no specific advantage to using an imaging system for defining the field-of-view for an optical detector using an atomic resonance filter. This is particularly true when large apertures are needed to collect weak signals over very wide fields-of-view.
SUMMARY OF THE INVENTION
The principal object of this invention is to provide an optical sensor or detector with a variable field-of-view which overcomes the practical limitations of the prior art.
A further object of the invention is to provide a non-imaging telescope with a variable field-of-view.
in a first aspect of this invention, a non-imaging optical telescope with a variable field-of-view utilizes a non-reflecting, telescopic, cylindrical tube having an aperture at one end. An atomic resonance filter of generally cylindrical shape is snuggly fitted within said tube, such that the light-receiving face of said filter is situated to receive light entering said tube through said aperture An optical sensor is situated at the output side of and coupled to said atomic resonance filter to sense re-emitted light from said filter. Moving said atomic resonance filter and said optical sensor as a unit axially within said tube, varies the distance of said atomic resonance filter from said aperture, thereby varying the field of view of said telescope.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is diagrammatic illustration of the preferred embodiment of a non-imaging optical detector and telescope with a variable field-of-view;
FIG. 2a is a geometric representation of the light shield/cone illustrating the angle of incidence of light on the detector of the embodiment of FIG. 1;
FIG. 2b is a diagrammatic illustration of elements of the detector of the embodiment of FIG. 1; and
FIG. 3 is a graph plotting the field-of-view and solid angle of a detector having a ten-inch pupil, according to the embodiment of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a diagrammatic view of the preferred embodiment of a non-imagining optical detector or sensor constructed with a telescope. Only the non-reflecting tube 12 of the telescope in shown in FIG. 1. Tube 12 has an aperture 14 to receive incoming light, designated generally by the reference number 16. An optical atomic resonance filter 18 is positioned within tube 12 to collect the incoming light. Typically, incoming light 16 of a specific wavelength entering the atomic resonance filter 18 elevates the atoms therein into an excited state, which state then deploys in a two- or multi-step cascade, emitting light at different wavelengths. A suitable optical sensor 20 is positioned to detect and collect re-emitted light signals from the atomic resonance filter 18. The optical sensor converts the detected re-emitted light signals to electrical signals proportional to the intensity of said re-emitted light signals. All or most of the incoming light signals 16 are absorbed by the vapor inside atomic resonance filter 18. The vapors re-emit the light signals at new wavelengths. Optical sensor 20, positioned on the output side of atomic resonance filter 18 collects much of the re-emitted light signals, and in turn produces electrical signals at its output.
The purpose of the present invention is to provide a means for varying the field-of-view from which the light is collected. Incoming light 16 fills the aperture 14 of tube 12 and is collected at the surface of the atomic resonance filter 18. The field-of-view angle θ is a function of the diameter D of the aperture 14 and the distance L from the aperture 14 to the collecting surface of atomic resonance filter 18, which is effectively the length of tube 12. For an aperture 14 having a fixed diameter D, as the distance L increases, the field-of-view angle θ decreases. Thus, to vary the field-of-view, one has only to provide a means to vary the distance L, which, in turn, is only a means to move the position of atomic resonance filter 18 and sensor 20 within tube 12. A positioning mechanism 22 is provided to move and guide atomic resonance filter 18 and sensor 20, as a unit, along tube 12. Positioning mechanism 22 is calibrated to position atomic resonance filter 18 and sensor 20 at precisely determinable distances from aperture 14 along the length of tube 12. Many alternative constructions are available from the art for positioning mechanism 22. For example, the atomic resonance filter 18 and sensor 20 could remain fixed in some structure and the tube 12 could be moved to vary L.
The operability and the feasibility of the invention depend upon the practical determination of the field-of-view. Referring now to FIGS. 2a and 2b, FIG. 2a shows a geometric representation for incoming light 16 entering the surface of atomic resonance filter 18, said filter having a radius R(R=D/2), enclosed in a cylindrical light shield, provided by tube 12, of distance L from aperture 14. To determine θ, the surface area of atomic resonance filter 18 is subdivided into infinitesimal elements of area dA, as shown in FIG. 2b. Then the optical solid angle Ω for each element dA is computed. The solid angle is defined in the conventional fashion: ##EQU1## where R is the radius of tube 12, a is the angle that a radial vector from the rim of aperture 14 makes with an axis running through the center of tube 12 and a point on the surface of filter 18, L is the length of tube 12, and r is the distance of dA from the center of atomic resonance filter 18. This double integral can be evaluated numerically. First, the integral over the angle a can be evaluated analytically. Then, the contributions from the total area of the atomic resonance filter 18 are summed, and the sum is normalized to the total area of the atomic resonance filter 18. This yields an average value for the solid angle over the area of atomic resonance filter 18.
Performing these calculations for a number of values for the distance L inside tube 12, the angle θ, and the radius R of atomic resonance filter 18, one skilled in the art can readily see that the values for the solid angle and the field-of-view are significantly larger than those for a design using a fixed lens. FIG. 3 shows a specific example for a tube 12 having a diameter of ten inches (10"). Those skilled in the art will alos recognize that the solid angle field-of-view, the mid-point angle, the half-area angle and the projected field-of-view angles are remarkably similar; that is, they convey the same information. It will also be obvious to one skilled in the art that if the cylinder 12 of FIG. 2a is infinitely long, it would be equivalent to using a field lens to decouple the field-of-view from the aperture of the detector tube 12. | A non-imaging optical telescope having a variable field-of-view utilizes an atomic resonance filter within its non-reflective tube. The atomic resonance filter received incoming light through the aperture of the telescope and re-emits the light to an optical sensor. The field-of-view is a function of the distance of the atomic resonance filter from the aperture. A positioning mechanism is provided to move the atomic resonance filter within the tube, thereby varying the field-of-view. | 6 |
BACKGROUND OF THE INVENTION
Enemy radar signals for detecting friendly craft and the like, often include a short (e.g., 1 microsecond) burst or pulse of energy of a microwave frequency (e.g., 1-35 GHz) encoded by modulation that produces a signal bandwidth such as 10 MHz. The denial, or jamming, of such a threat radar signal can often be effectively achieved by sequentially retransmitting, for each enemy-transmitted burst, a large number of bursts each similar to the enemy-transmitted burst. The bursts are retransmitted from a location between the enemy radar and friendly craft, but with amplitude and doppler modulation designed to cover, confuse and deceive the enemy radar operation and/or his equipment. A large number of such transmitted signals, such as 700 of them, is often very much more effective in denying the enemy radar system the ability to target friendly craft than only a few. However, it was found in the prior art, that when a large number of signals were sequentially generated by circulating the received and encoded signal through a loop, that noise and the like was repeatedly amplified at every passage through the loop, so that the encoded signal was lost to noise after several passes. A continuous repeater target denial device which could produce a long sequence of realistic target-like signals which are acted upon by the threat radar exactly in the same manner as true target signals, and which was of relatively simple and compact construction, would be of considerable value.
SUMMARY OF THE INVENTION
In accordance with one embodiment of the present invention, a target denial device of relatively simple and compact construction is provided, which can generate a large number of signal bursts that are all similar to a received signal burst. The device can be constructed so the large number of signal bursts have a controlled amplitude and phase modulation from pulse to pulse such as to be identical to the signals returned from real targets. The apparatus can include a recirculation loop which has an input for receiving a modified received burst such as an intermediate frequency representation of the received signal, and an output which sequentially delivers a large number of signal bursts that are each similar to the received signal burst. The recirculation loop can include an amplifier, a hard limiter which clips a circulating signal to limit all portions that are above a predetermined level to that level, and a low level limiter for blocking the portions of the circulating signal which are less than a low predetermined level. The hard limiter assures that the repeatedly amplified circulating signal is limited in amplitude, but the relative phase is preserved, while the low level limiter assures that noise below a defined threshold does not build up in amplitude.
The target denial device can include a plurality of detectors that each detect a different frequency band of the received signal. A group of local oscillator frequencies is generated, and one of them is selected according to the detected frequency band. The selected local oscillator is superheterodyned against the received signal, to produce an intermediate signal of low enough frequency to be processed by the recirculating loop.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a repeater target denial apparatus constructed in accordance with the invention.
FIG. 2 is a more detailed view of the recirculation loop of the apparatus of FIG. 1.
FIG. 3 is a schematic view of some of the blocks in the block diagram of FIG. 2.
FIG. 4 is an illustration of the desired contour amplifier of FIG. 2 bandpass gain characteristics in frequency space.
FIG. 5 is a block diagram of the contouring circuit used to achieve the contour of FIG. 4.
FIG. 6 is an alternate delay line device useful in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a target denial apparatus 10 which comprises a receiver 12 that includes an antenna and amplifier. The apparatus, which may be located on an aircraft, a ship, a ground site, or on a rocket projectile, receives threat radar signals from an enemy source which is attempting to detect the position and/or velocity of a friendly craft such as a ship at sea. Upon detection of the incoming threat signal, the apparatus generates a sequence of cover and deception signals which it retransmits over a transmitter 14 to confuse the interrogating enemy radar. An example is given in FIG. 1 to aid in understanding the system. In the example, a frequency spectrum of the received signal is indicated by the graph 16, which shows a received signal having a carrier or center frequency of 9.1 GHz (gigahertz), with a bandwidth of 10 MHz (megahertz). Another graph 18 is also provided which is a highly simplified graph showing the variation of the signal with time, and showing that the bursts last for 1 microsecond, and that the carrier signal (9.1 GHz) is phase or frequency modulated. At such radar frequencies that are well above 1 GHz, analog circuits are generally used to process signals in real time.
In this example, it is assumed that the center frequency of the radar burst, or pulse, or pulse train, can vary between 8 and 10 GHz. The apparatus includes a filter network 20 containing six radio frequency filters. One of them, indicated at 22, passes the frequency 9.05 to 9.4 GHz, which happens to include the 9.1 GHz burst of the example. The received radar burst passes through the filter 22 and is detected by a diode 24 that generates a DC signal which is delivered over a line 26 to a switching network 28. A group of lines 30 are connected to the switching network, each line carrying a different local oscillator frequency. The local oscillator frequencies are of the same order of magnitude as the received radar burst center frequency. An oscillator and multiplier device 32 generates the multiple local oscillator frequencies. The voltage on line 26 turns on a gate 34 which passes a corresponding local oscillator frequency present on a line 30d (of 9.7 GHz), through the gate to a divider 36. The divider directs some of the local oscillator frequency signal to a mixer or superheterodyning device 38. The mixer has one input 40 carrying the received signal and another 42 carrying the local oscillator frequency, and mixes them. This produces sum and different frequencies, with the difference frequency on the mixer output being amplified by an IF (intermediate frequency) amplifier 44. The IF amplifier acts as a passband filter by allowing only the difference frequency to pass. In the example, the difference between the received and local oscillator frequencies (9.1 and 9.7 GHz) is 600 MHz.
The intermediate frequency passing along line 46, is received by a recirculation loop 48 which has an output 50 that generates a train of bursts, each having the same phase history as the input at 46. Each of these bursts enters another mixer 52 where it is superheterodyned with the same local oscillator frequency signal (9.7 GHz) from line 54. The output 56 from the mixer passes through an amplifier 58, which also acts as a passband filter to pass the difference frequency while blocking the sum frequency. The output on line 60 from the amplifier contains a series of bursts, indicated by the simplified waveforms at 62a, 62b, and 62c, each burst being very similar to the original burst indicated at 18 which was received by the receiver 12. The train of bursts may include a large number of them, such as 700, which are all very similar to the originally received burst. The train of bursts passes through a programmable amplitude and frequency shift circuit 64 which has subcircuits 114, 115 that can introduce amplitude and doppler offset shifts, controllable for each burst in the repeated burst train. The train of bursts is finally delivered to a transmitter 14 which transmits the bursts so they are picked up by the hostile radar. Since the local oscillator frequencies used in down conversion at 42 and in up conversion at 54, are derived from the same source 30d, and the phase of the incoming signal is preserved in the recirculation loop 48, the sequence of retransmitted signals 14 are identical to the input signal 14 with the exception of the intentional modulation induced in 64 where this modulation is identical to that of the true target. This assures that the threatening radar will process these signals with the same efficiency as it processes true target signals assuring that the target denial device is operating at optimum efficiency and with minimum power requirements and will induce a sequence of false targets which will cover, confuse, and deceive the enemy radar.
The target denial apparatus 10 can operate very rapidly to transmit jamming bursts after receiving a hostile radar signal. For example, a first burst may be transmitted a few microseconds after receiving a pulse, and additional bursts may be transmitted at average intervals of a microsecond. The received signal passes rapidly through a filter of the filter network 20 to rapidly open the gate 34. The oscillator and multiplier circuit 32 continuously (prior to receipt of an enemy burst) produces all of the local oscillator frequencies so they can immediately pass through the gate to the divider 36 and to the mixer 38. A delay differential can be introduced by a delay device 66, so that the time of signal propagation between the receiver and mixer 38, is longer than the time of propagation between the receiver and detector 24. This allows the local oscillation frequency to reach the mixer before or at the same time as the received burst. The differential delay device 66 can be provided by an additional length of waveguide or coaxial cable, and/or the use of an optical transmission line along path 26.
A control circuit 70 is provided to control various parts of the system. The control circuit has outputs 72, including one 72a which controls the doppler offset circuit and another 72b which turns off the recirculation loop after the required number of generated bursts have been produced and/or when a next hostile radar signal is detected.
FIG. 2 illustrates some details of the recirculation loop 48 which receives an intermediate frequency burst on its inlet 46 and which delivers a long sequence of similar bursts on its output 50. The loop includes a combiner 80 which can receive inputs from the loop input 46 or a recirculation input 82, and which delivers the combined signal to a noise clipper 84. The noise clipper passes only voltages above a predetermined absolute value, and blocks voltages below that level. For a sinusoidal wave indicated at 86, the noise limiter blocks that portion of the wave in the region 88 which is less than L or above -L. The signal passing through the noise clipper also passes through a hard limiter or clipper 90 which limits all portions of the signal which have an absolute value greater than a predetermined amount H. Thus, the sinusoidal wave 86 is clipped to look like a trapezoidal wave at the location 92.
The output of the hard limiter or high-level limiter 90 is delivered to an isolating amplifier 94 which amplifies the signal to make up for losses in the recirculation loop. The isolating amplifier also blocks high frequency intermodulation components resulting from the noise clipping and hard limiting. The output of the amplifier not only passes to the output 50 of the loop, but passes along a recirculation loop portion on line 96 to a gate 98 that is controlled by a logic circuit line 72b, which closes the gate at receipt of a hostile radar burst and after transmission of the desired numbers of jamming bursts.
The burst passing through the gate 98 passes through a SAW (surface acoustic wave) delay line device 100 which is a commonly available piezoelectric device for delaying a signal. Such devices are commonly available which have a 350 to 370 MHz bandwidth, centered around a frequency of 700 MHz. The output of the delay device is delivered to a contour amplifier 102. The primary purpose of the contour amplifier is to reduce intermodulation products noise buildup generated by the limiting circuits 84 and 98, and especially the hard limiter 90, and also to reduce mismatches from residual internal acoustic reflections from the SAW device 100. In this way, the contour amplifier acts largely as a passband filter. The output of the contour amplifier is delivered to the input 82 of the combiner to recirculate the signal burst.
If the amplification of signals passing through the loop is slightly less than one, then the signals will gradually die out. If the amplification is slightly more than one, then the signals will gradually build up to very high amplitudes. Applicant chooses an amplification of approximately but greater than one, and uses the hard limiter 90 to prevent the uncontrolled buildup of the amplitude of the signals. The amplification of more than one, however, could result in low level noise in the system being amplified in every pass through the system until the noise appeared as part of the burst, which would provide unwanted additions to the encoding of the burst. The noise limiter 84, which blocks all noise below a certain level, avoids such build up of noise during each pass of the burst signal. The result of the hard limiting is that only frequency or phase modulation of the recirculating signal is preserved, while no amplitude modulation is preserved. However, if the originally received burst appears to be amplitude modulated (i.e., the peaks of the oscillations vary in amplitude), as indicated in FIG. 1 for the waveform 106, then an amplitude sensor 108 (e.g., a low pass filter) can be provided whose output on line 110 is a wave indicated at 112 which retains only the amplitude modulation of the received wave. This signal 112 can be stored and repeatedly used by an amplitude modulator 114 of the circuit 64 to introduce amplitude modulation to the bursts before they are transmitted, i.e., to produce a variation in amplitude similar (i.e., proportional) to that detected by the amplitude sensor. In many applications, only the phase or frequency modulation is of importance.
The noise clipper and hard limiter 84, 90 of FIG. 2 can be implemented by the circuit shown in FIG. 3. The noise limiter, or low level limiter 90 is formed by a pair of diodes 120, 122 which each conducts in a forward direction only when the voltage across it exceeds a predetermined low level to thereby block signals below that level. The hard limiter 90 includes a pair of diodes 124, 126 coupled through voltage sources to ground, so a corresponding diode conducts only when the signal amplitude exceeds a predetermined value to limit the signal to the value. The two diodes limit the absolute value. High and low voltage, or potential, inputs 121, 123 and high and low voltage, or potential outputs 125, 127 are provided at the noise clipper, with the terminals 125, 127 forming inputs to the hard limiter and terminals carrying high absolute value voltages.
The interaction of noise components with the desired signal during hard clipping can introduce intermodulation components (i.e, phase noise) which are of equal amplitude and can lie within the passband of the recirculation loop. It is recognized that the only important intermodulation signals are always symmetrically disposed in phase about the incoming signal, and that the average of these signals always falls at the same phase as the desired signal. Therefore we introduce a contoured amplifier 102 whose gain is contoured monotonically downward in frequency space over the loop bandpass as illustrated in the graph 129 of FIG. 4. This assures that the average gain of the noise signal intermodulation products are always less than the loop signal gain (which is set to very slightly over unity), and are therefore always at a gain less than unity and supressed relative to the desired signal. FIG. 4 shows an example where the center frequency at 131 is 600 MHz, a harmonic noise at 133 is at 650 MHz and residual noise at 135 is at 550 MHz. The average gain in the recirculation loop at these two noise frequencies, indicated at point 137, is less than the gain of the center frequency at 131, and therefore if the loop gain is only slightly over unity the noise will not increase without limit. The gain indicated by graph 129 has a derivative, or slope, that progressively decreases at progressively greater frequencies (from a high positive valve through zero to a large negative value), in its passband (e.g., 525 to 875 MHz).
FIG. 5 illustrates a bandpass generator contour circuit, which is part of the contour amplifier, and which acts as a controlled dispersion filter in series with the noise clipper and hard limiter. The contour amplifier bandpass generator circuit of FIG. 5 is essentially a voltage divider formed by two different resonant circuits 130, 132. The mix of the impedences of the two circuits 130, 132 determines the passband of the contour amplifier. It is possible to vary the impedances, as by varying the capacitors 134, 136 to change the passband in accordance with FIG. 4.
Although the SAW delay device 100 is largely "flat" across a wide bandwidth, it can produce ripples of gain across its bandwidth. Continuous recirculation over the same path may integrate the effects of these fixed ripples. However an interruption of the recirculation before the ripples build up sufficiently o pass through the noise clipper circuit, will suppress the ripples where one SAW delay device has a higher than average gain at one frequency (i.e., a ripple of gain). FIG. 6 illustrates an alternate circuit portion 140 which can be used to minimize the build up of such recirculating ripples, if required. In FIG. 6, two alternate loop portions formed by delay line devices 142, 144 are provided which may have the same or close to the same delays, but which will have different ripple characteristics due to the fact that the ripple characteristics of each individual SAW delay device is different. A pair of switches 146, 148 switch different delay lines into the circulation loop, such as at every other or every third circulation. Where one SAW delay device has a higher than average gain at one frequency, the other will have an average lower than average gain at that frequency, to help avoid too high or too low a gain at that frequency during many recirculations. More than two delay devices can be alternately switched in.
Thus, the invention provides a repeater jammer apparatus that can use existing small solid state components and that is of relatively simple construction, which can quickly detect a received radar burst and rapidly generate a long sequence of cover, confusion and deception signal bursts similar to those received from a sequence of true targets by the threat radar, with the dynamic properties of the bursts under friendly control. A recirculating loop for generating multiple bursts, includes a low limiting circuit that blocks portions of signals below a predetermined value. The low limiting circuit avoids the build up of noise when used in a loop that includes an amplifier, and a hard limiter that clips signals above a predetermined amplitude to retain their phase, and which can include a contoured amplifier to suppress intermodulation noise components. The receiver circuit of the apparatus includes a plurality of radio frequency filters, with one of them passing the frequency band of the enemy radar signal, so a corresponding one of a plurality of local oscillator frequencies that are all continously generated, can be used to mix with the received signal for recirculating in an IF loop. A differential time delay assures that the appropriate local oscillator frequency arrives at the loop down converter prior to or at the same time as the signal. The apparatus also includes an amplitude and doppler offset modulation means to control the signature of the synthetic target stream generated by the apparatus so as to maximize the cover, confusion, and/or deception which friendly forces wish to impart on the enemy radar system.
Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art, and consequently, it is intended that the claims be interpreted to cover such modifications and equivalents. | A circuit is described which receives enemy radar signals in the form of encoded bursts or pulses, and which immediately generates and transmits, in sequence, a large number of target denial signals which are similar to the received signal. The transmitted signal masks signals from friendly craft, and deceives the enemy by providing rational false targets for him to engage. The carrier frequency of the enemy or threat, signal is detected, and is used to select one of a group of local oscillation signals which are superheterodyned with the received signal to produce an IF (intermediate frequency) signal which is recirculated and and superheterodyned with the local oscillator frequency to produce a series of signals for transmission that are similar to the received signal. The amplitude and offset doppler of each of the target denial signals are individually controlled prior to retransmission to maximize performance. In the recirculation loop, the circulated signal is hard limited, or clipped, and is also low limited, and also passed through a contoured bandpass to avoid the build up of noise. | 6 |
This is a division of application Ser. No. 737,613, filed May 24, 1985, now U.S. Pat. No. 4,677,451.
BACKGROUND OF THE INVENTION
This invention relates to semiconductor devices, and more particularly, to a field effect transistor.
Integrated circuit technology has developed a wide variety of devices having specialized characteristics, which may be fabricated on single chips with high packing densities. Among such specialized devices are permeable base transistors (PBT) for use in discrete and microwave integrated circuits. As set forth in U.S. Pat. No. 4,378,629, a permeable base transistor includes a single crystal semiconductor substrate forming a first emitter or collector, a Schottky-barrier metallic base layer overlying the substrate and having slits therethrough (so that the remaining metallic layer resembles "fingers" extending into the semiconductor material), and an epitaxial semiconductor single crystal filling the slits and overlying the base layer, thereby forming a second collector or emitter contact. In opertion, when a voltage is applied between the emitter and collector contacts, current flow through the transitor is limited by application of a voltage to an external contact of the metal base layer.
The performance of permeable base transistors is limited by high internal capacitance and geometrical restrictions imposed to control such capacitance. More specifically, to prevent the depletion capacitance from seriously affecting performance, the lateral gate width (i.e., the width of each finger) must be kept less than the lateral channel width (i.e., the spacing between the fingers). The optimum channel width may be as small as about 0.08 micrometers, limiting the gate width to about this same value. A greatly decreased gate width may in turn result in reduced high speed device performance because of increased resistivity between the gate metal and its external contact. That is, the fine size of the "lead" to the gate metal may limit the rate at which the voltage in the gate may be varied.
Thus, while permeable base transistors offer significant promise as microwave transistors, this promise has not been realized because of internal parasitic capacitance and resistance problems. There has been proposed no approach for achieving improved performance, either with a newly conceived device or by improving upon existing permeable base transistor technology. Accordingly, there exists a need for obtaining improved high-frequency performance of a gated semiconductor device, while simultaneously allowing further size reduction so as to permit higher packing densisties of devices in chips. The present invention fulfills this need, and further provides related advantages.
SUMMARY OF THE INVENTION
The present invention provides a semiconductor device component, and a process for its fabrication, wherein current flow through semiconductor channels is limited by a voltage applied to a buried gate. Internal parasitic capacitance resulting from the interface of the gate with the surrounding semiconductor structure is reduced, directly improving metallic performance and allowing the gate width to be increased relative to the channel width. In turn, the increased gate width reduces the resistivity of the gate, so that both the internal parasitic capacitance and the gate resistance are reduced. High frequency performance of the device component is substantially improved, particularly when the device component is optimized in a manner to be described. Fabrication difficulties inherent in permeable base transistors are also reduced in some cases by using graphoepitaxy or masked epitaxial crystal growth. The resulting device component offers superior performance as a discrete microwave transistor, and allows the fabrication of high speed, low power integrated logic circuits.
In accordance with the invention, a semiconductor device component comprises a semiconductor single crystal first layer; a layered gate structure overlying the first layer, the gate structure including an insulator second layer overlying and in contact with the first layer, a metallic third layer overlying and in contact with the second layer, and having an external ohmic contact, an insulator fourth layer overlying and in contact with the third layer, this gate structure having a plurality of continuous channels vertically therethrough extending downwardly to the first layer; and a semiconductor fifth layer epitaxially deposited on the first layer and filling the channels, whereby a voltage applied to the ohmic contact controls the vertical current flow in the fifth layer.
In another aspect, a semiconductor device component comprises a semiconductor substrate, a column of semiconductor material extending upwardly from the substrate, the semiconductor material being epitaxially related to the substrate; a pair of layered gate structures extending upwardly from the semiconductor substrate, the gate structures contacting laterally opposing sides of the semiconductor column and each comprising a layer of insulator contacting the substrate, a metallic layer overlying the insulator layer contacting the substrate, and a layer of insulator overlying the metallic layer; and an external ohmic contact to each of the metallic layers. This embodiment of the invention may be viewed as a single element of the multielement device described previously, and can be extended to include a plurality of upwardly extending semiconductor channels or columns having a selected three-dimensional geometry, so that the channels are separated by "fingers" of the gate structure. Optionally, an n + doped overlayer may be deposited epitaxially upon the top of the gate structures and the column.
The device component of the present invention is compatible with all known semiconductor technologies, but gallium arsenide and III-V compound technologies are preferred. Using gallium arsenide-based technology, the preferred semiconductor material is n-type gallium arsenide, the insulator is silicon dioxide or silicon nitride, and the metallic gate is any appropriate metal such as tungsten, aluminum or molybdenum.
Specific design parameters for geometric relationships in preferred embodiments of the device component are set forth subsequently, and summarized in the design rules of equations 1-3.
A process for fabricating a preferred embodiment of the semiconductor device component comprises the steps of furnishing a semiconductor single crystal first layer; forming successively upon and overlying the first layer an insulator second layer, a metallic third layer, and an insulator fourth layer; removing material from the second, third and fourth layers to form a continuous vertical channel therethrough, extending downwardly to expose an area of the first layer; and depositing epitaxially, on the exposed area of the first layer, a semiconductor fifth layer extending upwardly in the channel formed in the step of removing. This process is performed utilizing procedures appropriate to the semiconductor technology chosen, but typically involves process steps such as crystal growth, epitaxial deposition, graphotaxy, masking and photolithography. The fabrication procedure is fully compatible with existing integrated circuit technologies, and allows the integration of the semiconductor device of the invention with other devices in large scale arrays on chips. All necessary device fabrication technologies have been demonstrated for gallium arsenide-based devices.
It will now be appreciated that the semiconductor device and process of the present invention present important advances in the field of semiconductor technology. Vertical channel field effect transistors may be fabricated as discrete devices or as a part of integrated circuits utilizing advanced, but well documented, technology. The devices themselves allow the control of current flowing through the channels by application of a voltage to a gate contact. The insulator layers lying above and below the metallic gates reduce the parasitic capacitances on the broad faces of the gates, directly improving the high frequency performance of the device. Reduction of parasitic capacitance associated with the broad face allows the gates themselves to be made laterally wider than was previously possible, and specifically wider than the channel widths, to reduce the resistivity of the gates, further improving high frequency performance. Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a semiconductor device component with portions broken away to illustrate the layered structure;
FIG. 2 is an enlarged side sectional view of the component of FIG. 1, taken generally along line 2--2;
FIG. 3 is an enlarged end sectional view of the component of FIG. 2, taken generally along line 3--3;
FIG. 4 is an enlarged side sectional view of another embodiment of the invention, in a view similar to that of FIG. 2;
FIG. 5 is an enlarged end sectional view of the component of FIG. 4, taken generally along line 5--5; and
FIG. 6 is a process block diagram of fabricating the device component illustrated in FIGS. 2 and 3, with the structure resulting from each step illustrated in the view of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As illustrated in FIGS. 1-3 for a first preferred embodiment, and FIGS. 4-5 for a second preferred embodiment, the present invention is embodied in a semiconductor device component which may be fabricated as a discrete device or as part of an integrated circuit. Referring to the embodiment of FIGS. 1-3, the device component, indicated generally by the numeral 10, is fabricated on a substrate comprising a semiconductor single crystal first layer 12. The first layer 12 is typically a chip of semiconductor material doped n+ and having a thickness up to about 0.25 millimeters. The lateral size of the chip may be selected as required to accept the discrete device or integrated circuit to be fabricated thereupon.
A layered gate structure 14 overlies the first layer 12, the gate structure 14 generally being a column extending upwardly from the substrate first layer 12. The gate structure 14 includes three layers. An insulator second layer 16 overlies and contacts the upper surface of the semiconductor first layer 12. A metallic third layer 18 overlies and contacts the upper surface of the insulator second layer 16. An externally accessible base contact 22 provides an external electrical connection to the metallic third layer 18, so that a voltage may be applied to the third layer 18 by an external voltage source (not shown). An insulator fourth layer 20 overlies and contacts the upper surface of the metallic third layer 18.
As illustrated in FIG. 1, in the presently preferred embodiment the metallic third layers 18 are elongated in one horizontal direction (left-to-right in FIG. 2), to form relativey flat, elongated platelets, convenienty referred to as "fingers" 28. The fingers 28 are disposed parallel to each other and are spaced apart in a lateral direction 36, as shown in FIG. 3. The width of the fingers in a lateral direction 36 is termed a gate width 26, and the spacing between the fingers in the lateral direction 36 is termed a channel width 46. The fingers 28 become gates for controlling current flowing in a vertical direction 24 in a vertical channel 38 lying between the fingers 28. In the illustrated embodiment, the fingers 28 (i.e. the third layers 18) are conveniently joined together at one end by a common contact 30, which in turn is electrically continuous with the base contact 22. Electrical contact to the fingers 28 and the common contact 30 is made by extending the base contact 22 into a depression 32 in the device component 10, which depression 32 is deep enough to allow access to the common contact 30. Alternatively, each finger 28 may be separately and individually contacted to an external voltage source (not shown), as where the device component 10 is used in a logic array.
In this embodiment, the gate structure 14 amounts to two vertical metal-insulator-semiconductor arrays, oriented back-to-back with a common metal portion, the metallic third layer 18. This system replaces the metal-semiconductor Schottky barriers found in conventional permeable based transistors such as disclosed in U.S. Pat. No. 4,378,629. The capacitance of the gate structure 14 in the direction perpendicular to the broad face of the first layer 12, herein termed the vertical direction 24, is a series combination of the capacitance of the insulator layers 16 and 20, preferably an oxide, and the spacecharge capacitance of the semiconductor material contacting the insulator layers 16 and 20. The metal-insulator capacitance is the largest capacitance of the system, and may be made arbitrarily small by increasing the thicknesses of the second layer 16 and the fourth layer 20.
By contrast, the capacitance associated with the Schottky barriers of the metal-semiconductor interface of permeable base transistors may not be readily varied except by changing the lateral area of the metallic third layer 18, thereby imposing a severe design constraint on the permeable base transistor. Replacement of the narrow depletion region of the metal-semiconductor interface of a permeable base transistor with the thicker oxide layers of lower dielectric constant significantly reduces the gate contact parasitic capacitance of the device component 10, as compared with that of a permeable base transistor. Reduced parasitic capacitance per unit interface surface area of the gate structure allows the gate width 26 of the gate structure 14 to be increased. A larger gate width increases the cross-sectional conducting area of the third layer 18, thereby reducing the series resistance from the base contact 22 to points within the third layer 18.
Lying between the fingers 28, and thence between the adjacent gate structures 14, is a semiconductor fifth layer 34. The lateral sides of the gate structures 14 and the fingers 28, lying normal to the lateral direction 36, define the vertical channel 38 extending upwardly from the semiconductor substrate first layer 12. The semiconductor fifth layer 34 fills the vertical channel 38 so defined, and is contacted on its laterally opposed sides by laterally adjacent gate structures 14. More specifically, the semiconductor fifth layer 34 is contacted on its laterally opposing sides by the adjacent, laterally separated fingers 28 contained therein, so that the fingers 28 can act as gates for limiting vertical current flow in the semiconductor material lying in the vertical channels 38.
The semiconductor fifth layer 34 is epitaxially related to the semiconductor substrate first layer 12, and may be of the same composition, crystal orientation, defect structure, and electrical characteristics. Thus, while the first layer 12 and the fifth layer 34 are illustrated as different elements in the figures, in reality these two layers form a single, physically contiguous crystal in which the gate structure 14 is buried. Alternatively, and as illustrated in FIG. 3, the semiconductor material in the fifth layer 34 may also be more heavily doped n++ adjacent an upper side surface 39 of the insulator layer 20 and a lower side surface 41 of the insulator layer 16, remote from the metallic third layer 18, in areas indicated by the numeral 43. The heavier n++ doping provides excess charge carriers to lower the resistivity and raise the conductivity of these regions, thereby improving the high frequency performance of the device. Care is taken so that the heavier doping does not extend to the central portion of the vertical channel 38 laterally adjacent the metallic third layer 18, which would interfere with the current-limiting function of the device.
In the first preferred embodiment of FIGS. 1-3, the fifth layer 34 is extended vertically upwardly to a height greater than that of the gate structure 14, and laterally to form a semiconductor gate overlay 40. As used herein, the semiconductor gate overlay 40 is part of the semiconductor fifth layer 34. In the second preferred embodiment illustrated in FIGS. 4-5, the height of the semiconductor fifth layer 34 in the vertical direction is the same as that of the gate structure 14, so that no semiconductor overlay 40 is present. Nonetheless, the adjacent portions of the semiconductor fifth layer 34 separated by gate structures 14 may remain continuous beyond the tips of the fingers 28, if desired. The different channels 38 could also be isolated from each other, as where logical arrays are formed containing the channels. Such various arrangements of the semiconductor fifth layer 34 are within the scope of the present invention.
Semiconductor contacts 42 are positioned on the vertically opposing faces of the device component 10, to provide external electrical contact to the semiconductor material of the first layer 12 and the fifth layer 34. The opposing contacts 42 act as source and drain contacts for the device. When an electrical potential is applied between the semiconductor contacts 42, an electrical driving force for current flow through the vertical channels 38 is created. Under the influence of this driving force, an electrical current flows in the vertical direction 24, unless otherwise limited.
The current may be limited by applying a voltage to the base contact 22, and thence to the third layers 18 (fingers 28), which creates a potential field extending inwardly into the semiconductor material of the fifth layers 34 of the vertical channels 38, adjacent a Schottky barrier gate source 44 portion of the third layer 18. The internal electrical potential thereby generated in the semiconductor material of the vertical channels 38 limits the width of the conducting volume and thence the current flow in the vertical direction through the vertical channels 38, in the manner described in U.S. Pat. No. 4,378,629. By contrast with the permeable base transistor of that patent, the presence of the insulator second and fourth layers 16 and 20 reduces the parasitic capacitance of the device component 10, thereby improving the performance of the device component 10, particularly at high frequencies.
While the design of the device component 10 inherently attains improved performance over the conventional permeable base transistor, its performance may be optimized by adhering to design rules relating the material characteristics and geometrical parameters of the device component. The first design rule sets forth the relationship between the channel width 46 of the vertical channel 38 and the doping density of the semiconductor material of the fifth layer 34 lying within the channel 38. For an n-channel device component 10, the device should begin conducting current between the source and drain contacts 42 when a gate-source potential greater than a threshold V t is applied. This condition is met when the Schottky barrier depletion region between the metallic third layer 18 and the semiconductor fifth layer 34 extends just across the channel width 46. Any greater voltage applied to the gate 18 uncovers an ohmic conducting path between the semiconductor contacts 42. This condition is met when: ##EQU1## W c is the channel width 46, ε s is the semiconductor permitivity, φ is the Schottky barrier height, q is the magnitude of the electron charge, and N ch is the channel semiconductor doping density. As equation 1 demonstrates, it is desirable to have flexibility in fixing the channel width 46 to optimize electrical performance of the device component 10, without the necessity of simultaneously fixing the gate width 26. The reduction of parasitic capacitances in the present device allows the gate width 26 to be fixed arbitrarily and independently of the channel width 46, and in particular the gate width 26 may be set to a value greater than the channel width 46.
The second design rule defines the preferred minimum thickness of the insulator layers 16 or 20, above and below the metallic third layer 18 which forms the gate of the device component 10. To achieve performance superior to that of conventional permeable base transistors, the capacitance of the device component 10 must be less than the corresponding capacitance due to the Schottky barrier on the broad face of the metallic third layer 18 normal to the vertical direction 24. This condition is met when ##EQU2## t is the insulator thickness in the direction parallel to the vertical direction 24, and ε ox is the oxide permitivity. Improved performance may be attained by making the insulator layers 16 and 20 thicker than this preferred minimum value. For example, if the insulator layers 16 and 20 are each made n times the thickness of this preferred minimum value, the gate width 26 may be increased by a factor of n, resulting in a 1/n reduction in gate resistance. Thus, from the viewpoint of device performance, thicker insulator layers, possibly extending vertically the entire distance to the semiconductor contact 42, reduce the gate contact parasitic capacitance. If the n+ contact regions are doped at a sufficiently high level, increasing the oxide thickness creates no difficulties with excessive source and drain resistance.
The third design rule defines a preferred minimum dimension for each of the spacings between the gate metallic third layer 18 and the n + -contact regions, the source and drain semiconductor contacts 42. Since most of the voltage drop between the semiconductor contacts 42 occurs in the n-channel semiconductor between the n + -contact and the gate layer 18, this dimension must be sufficiently large to prevent electric field magnitudes in excess of the avalanche ionization field from forming. This design requirement is satisfied when
L.sub.D, L.sub.s ≧V.sub.max /E.sub.A (3)
L s is the gate to n + -source spacing, L D is the gate to n + -drain spacing, V max is the maximum drain-source voltage, and E A is the semiconductor avalanche ionization electric field.
As noted previously, the three design rules provide design guidance for the most preferred embodiments of the invention. The most preferred embodiments achieve performance superior to that of the conventional permeable base transistor, but satisfaction of the design rules is not a prerequisite to operability of the device component 10.
FIG. 6 illustrates in block diagram form a preferred process for fabricating a semiconductor device component 10 in accordance with the invention. The substrate semiconductor first layer 12 may be furnished by growing a semiconductor single crystal of the appropriate thickness and size. Such crystals for use in fabricating intergrated circuits are typically about 0.25 millimeters thick and sufficiently large in lateral extent to accommodate the necessary devices. The insulator second layer 16 is then deposited to overlie the first layer 12, the metallic third layer 18 is deposited to overlie the second layer 16, and the insulator fourth layer 20 is deposited to overlie the metallic third layer 18. The precise parameters of the deposition techniques will be determined by the insulator and metal chosen, but such processes are well known to those skilled in the art.
The gate structures 14 are formed by masking a pattern on the upper surface of the fourth layer 20, and then removing the unmasked material, again by techniques well known in the art. Typically, a mask is deposited having the shape of the fingers 28 and the contact 30, on the upper surface of the fourth layer 20. The unmasked material is then removed by a suitable technique such as chemical or other etching. The removal of material results in the continuous vertical channel 38 downwardly through the layers 16, 18 and 20, to expose areas on the upper surface of the first layer 12.
The semiconductor fifth layer is next epitaxially deposited onto the exposed upper surface of the first layer 12. Deposition is by any suitable technique for depositing a doped semiconductor, preferably of the same general composition as the substrate first layer 12. The vertical height of the fifth layer 34 may be limited to the same thickness as that of the gate structure 14, resulting in a device of the type pictured in FIG. 5. Alternatively, the height of the fifth layer 34 may be made greater than that of the gate structure 14, to produce a device of the type pictured in FIG. 3. In the preferred gallium-arsenide based device, if the gate width 26 is established at less than about 20 micrometers, and the insulator 20 is silicon dioxide, no deposition and growth of n+ doped gallium arsenide occurs on the exposed top face of the fourth layer 20 until the portion of the vertical channel 38 lying between the gate structures 14 is filled. This phenomenon is known as grapho-epitaxy. After the vertical channel 38 is filled, the semiconductor fifth layer 34 extends further vertically and laterally by single crystal growth. FIG. 6 specifically illustrates the preferred procedure for fabricating the device illustrated in FIG. 3.
Finally, and optionally, external ohmic contacts are added to complete the device component 10. The semiconductor contact 42 is deposited onto the lower surface of the first layer 12. The semiconductor contact 42 is also deposited onto the upper surface of the fifth layer 34 (in the embodiment of FIG. 3) or the upper surface of the fifth layer 34 and the upper surface of the gate structure 14 (in the embodiment of FIG. 5). The base contact 22 is provided by etching or otherwise forming the depression 32 into the upper surface of the device component 10, of sufficient depth to expose the metallic third layer 18, and the common contact 30, if provided. An ohmic contact material is then deposited over the exposed area to provide an electrical contact to the third layer 18 along the upper surface of the device component 10. Other means may be used to provide the necessary electrical contacts, in specific device structures.
The device component 10 of the present invention is preferably fabricated utilizing gallium arsenide-based or other III-V compound and alloy semiconductor technologies. In gallium arsenide-based technologies, the first layer 12 and fifth layer 34 are preferably n+ doped gallium arsenide, the insulator second layer 16 and insulator fourth layer 20 are preferably silicon dioxide or silicon nitride, the metallic gate third layer 18 is any metal such as tungsten, aluminum, molybdenum, zirconium, osmium, iridium, or ruthenium, and the ohmic contacts 42 are any suitable conducting material such as those just listed. In III-V based technology, the first layer 12 and fifth layer 34 are preferably n+ doped III-V compounds and alloys, the insulator second layer 16 and insulator fourth layer 20 are preferably silicon dioxide or silicon nitride and the metallic third layer and external contacts are any suitable metal such as those set forth above.
A variety of complex devices may be fabricated from the basic device component 10. Such a device component minimally requires a single vertical channel 38 of semiconductor fifth layer 34 material, laterally bounded by a pair of gate structures 14 contacting the laterally oppositely disposed sides of the vertical channel 38. Additional fingers 28 of the gate structure 14 may be added in parallel extending laterally, in the manner illustrated in FIG. 1. More complex patterns of the gate structure 14 and the fingers 28 may be formed for specific devices, as, for example, illustrated in U.S. Pat. No. 4,378,629, whose disclosure is herein incorporated by reference. That is, the device component 10 may be substituted for conventional permeable base transistors in many specific devices, to achieve improved operating characteristics.
It will now be appreciated that, through the use of this invention, there is provided a vertical channel field effect transistor having improved high frequency performance, which is particularly suited as a microwave transistor or a high speed, low power integrated logic circuit element. By introducing insulator layers into the gate structure above and below the metallic gate, parasitic capacitances are reduced and the gate width may be increased, both results contributing to improved high frequency performance. Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. | A semiconductor device component, and process for preparation thereof, wherein current flowing in a vertical channel of semiconductor material is controlled by metallic gates laterally disposed on either side of the channel. Insulator layers are positioned overlying and underlying each gate, to reduce parasitic capacitance which would otherwise be present if the metallic gate material were in contact with overlying and underlying semiconductor material. Reduction of the capacitance allows the use of wider gate strips, thereby reducing the series resistance to an external gate contact. These changes significantly improve the high-power, high-frequency performance of the device component, as compared with permeable base transistors. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates generally to laser-based systems useful in construction applications and, more particularly, to a laser-based system and method for measuring the X-Y coordinate of a point in a continuously changing frame of reference.
In the construction industry, the level of automation and robotization is very low. One reason for this is the difficulty of properly positioning machines and tools. In the construction of commercial buildings, for example, various points of reference have to be established, such as placement of floors, ceilings, electrical wiring, plumbing, and heating and cooling ducts. Establishing reference points is time consuming and expensive, particularly as such work is often contracted out to companies which specialize in this work. Moreover, for many applications, the machine has to move toward the product. When the reference point is continuously changing, the difficulty of positioning the machine is compounded.
In prior laser-based systems, such as that disclosed in U.S. Pat. No. 3,588,249, for example, a reference plane is established throughout a work site by a transmitter which emits laser energy in the level reference plane. The laser beam is projected radially outward from the transmitter and rotated continuously through 360 degrees to sweep around the entire work site. One or more receivers may be employed throughout the work site to sense the location of this reference plane. Such receivers may be mounted on a surveyor's rod, as described in U.S. Pat. No. 4,030,832, or they may be employed as part of a control system for construction or agricultural equipment, as described in U.S. Pat. Nos. 3,813,171; 3,873,226; 3,997,071; and 4,034,490.
In order to track the movement of a reference point, prior art laser systems, such as the laser survey system disclosed in U.S. Pat. No. 4,830,489, have provided not only elevation information, but also position information in two other axes. The system includes a laser transmitter, located at a reference position at a work site, which sweeps a laser beam radially in a reference plane. The system includes a receiver, located on mobile earthmoving equipment operating at the work site. The receiver has a sensor that determines the relative elevation of the laser reference plane. The receiver also includes a pair of reflectors, each of which reflects laser energy back to the transmitter. The laser transmitter also has a sensor which receives the reflected laser energy, and, in response thereto, produces receiver position information for transmission to the receiver.
The laser transmitter is designed to rotate the laser beam continuously through 360 degrees at a substantially constant angular velocity and thus sweep the beam past the two reflectors of the receiver once during each revolution. During each revolution of the laser beam, the transmitter receives back two short bursts or pulses of laser energy from the two reflectors. Thus, since the laser beam sweeps at a substantially constant angular velocity and the distance between the reflectors is fixed, the time period between receipt of these two pulses provides an accurate basis for the calculation of the range or distance of the receiver from the transmitter. However, since the accuracy of the range calculation is dependent upon a uniform rotational velocity for the laser beam, any variability in the rotational velocity will decrease the accuracy of the range calculation.
Three-dimensional laser based systems are generally complex and expensive. It is sometimes necessary and, often, sufficient to know only the exact location of a reference point within a two-dimensional framework. A method for locating a reference axis of a mobile robot vehicle in a two-dimensional structured environment is disclosed in U.S. Pat. No. 4,796,198. In that reference, a laser carried by the mobile vehicle generates a rotating beam which strikes retroreflectors located at the periphery of the structured environment. Computation means compute the location of the mobile vehicle based on the location of the retroreflectors and the reflected light. In a 50 foot by 50 foot structured environment, for example, the location coordinates of a moving vehicle can be determined to an accuracy of approximately 1 inch. However, construction industry accuracy requirements often call for accuracies within a centimeter or a few millimeters. In addition, many applications require not only the X-Y position of a point, but also an indication of the direction in which the point is moving or is to be moved.
It is seen then that there is a need for a positioning system and method wherein highly accurate position coordinates and orientation of a point, which are insensitive to deviations in the rotational velocity of the rotating light beam, can be determined.
SUMMARY OF THE PRESENT INVENTION
This need is met by the position sensing system and method of the present invention wherein the X-Y coordinates of a point can be calculated by triangulation. The triangulation calculation is based on the coordinates of at least three retroreflective elements spaced apart from each other around the periphery of a two-dimensional coordinate frame, and the measured angles between the lines projected radially outward from a point located at an actual position of a light transmitting and detecting means to each of the retroreflective elements.
In accordance with one aspect of the present invention, a system for determining the position of a point in a two-dimensional coordinate frame of reference comprises: at least three stationary retroreflective elements spaced apart from each other and stationed at known coordinates in the two-dimensional coordinate frame, the retroreflective elements capable of reflecting light back toward a light source; light transmitting and detecting means, positionable at the point, for generating a rotating beam of light to illuminate each of the stationary retroreflective elements during each rotation, and for detecting the beam of light when it is reflected from the stationary retroreflective elements and generating an output signal in response thereto; and computer means responsive to the output signal for computing, from the known coordinates of the retroreflective elements and from the angular orientation of the beam when the beam illuminates the retroreflective elements, the coordinates of the position of the point in the two-dimensional coordinate frame of reference.
In a preferred embodiment of the system, the light transmitting and detecting means comprises: means for generating a beam of light; means for projecting the beam of light at a substantially constant rotating angular velocity toward the retroreflective elements; means for receiving the beam of light reflected from the retroreflective elements corresponding to the illumination of each of the retroreflective elements during each rotation of the beam; and azimuth means, responsive to reflection of the beam of light from the retroreflective elements, for continuously transmitting angle signals indicative of an azimuth angle at which the means for receiving the beam of light is positioned with respect to each of the retroreflective elements.
In accordance with one aspect of the system for determining the position of a point, at least one of the stationary retroreflective elements is a distinctive retroreflective element, such as a retroreflective bar code element. In a structured environment, then, the computer means can designate a sequential number to each retroreflective element in a rotation, and the number will remain the same for each rotation.
In a further aspect of the present invention, the light transmitting and detecting means includes a member rotating with the beam, the member having a periphery and further having a plurality of angularly positioned elements spaced around the periphery which divide a revolution of the member into a plurality of generally equal partial revolutions; and a means for detecting movement of each of the elements past a predetermined point as the member rotates. Preferably, the plurality of angularly positioned elements comprises a plurality of apertures and the means for detecting movement of each of the elements comprises a light source paired with a photodetector element.
The present invention also provides a method for determining the position of a point in a two-dimensional coordinate frame of reference. The method comprises the steps of: locating at least three stationary retroreflective elements spaced apart from each other and stationed at known coordinates in the two-dimensional coordinate frame, the retroreflective elements capable of reflecting light back toward a light source; transmitting a rotating beam of light in a plane to illuminate each of the stationary retroreflective elements during each rotation; calculating an angle between the direction of the beam of light when the beam illuminates each of the retroreflective elements; tracking behavior of a rotation; using the behavior of a rotation to calculate angular measurements; and determining the position of the point based on the angular measurements and the coordinates of the retroreflective elements.
In a preferred embodiment of the method for determining the position of the point, the step of tracking behavior of a rotation further includes the steps of mounting a member on a rotating shaft, the member having a periphery and further having a plurality of apertures located at the periphery which divide a revolution of the member into a plurality of generally equal partial revolutions; and registering a time differential between each adjacent pair of the plurality of apertures as the member rotates. Also, the method includes the step of interpolating between corresponding angle measurements of an adjacent pair of the plurality of apertures to determine exact angles between each pair of apertures.
Accordingly, it is an object of this invention to provide a position sensing system and method, wherein the X-Y coordinates of a point can be calculated by triangulation. It is also an object of this invention to provide such a system and method wherein the orientation of the system when it is located at the point can be determined. It is a further object of this invention to provide such a system wherein the calculations are insensitive to deviations in the rotational velocity of the rotating light beam. Finally, it is an object of this invention to provide such a system which utilizes software to calibrate a code wheel or other member to improve the accuracy of the calculations.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the position sensing system of the present invention located at a point within a structured environment defined by four intersecting walls;
FIG. 2 is a side view, with parts broken away, of a light transmitting and detecting means of the position sensing system of FIG. 1;
FIG. 3 is an exploded partial top view of a rotating member illustrated in FIG. 2;
FIG. 4 is a calibrating system which is used in conjunction with related software to calibrate the member of FIG. 3;
FIG. 5 is a schematic block diagram of a hardware interface, controlled by software, which supports the position sensing system of the present invention; and
FIG. 6 is a diagrammatic representation of the position sensing system transmitting a beam of light toward a distinctive retroreflective bar code element in accord with the block diagram of FIG. 5 and bar code recognition software.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The position sensing system and method of the present invention is advantageously utilized in either a structured environment 10, as shown in FIG. 1, or an external environment, to generate constantly updated information on the exact location of a point 12. Typically, light transmitting and detecting means 14, best illustrated in FIG. 2, is positioned at the point 12 for transmitting a rotating beam of light 16, which is emitted by a light source such as laser 20 of FIG. 2, and reflected back to the light transmitting and detecting means 14 by a series of retroreflective elements 18. The position sensing system is also capable of determining the orientation of the light transmitting and detecting means 14 which is positioned at the point 12. The rotating beam of light 16 should be of a size appropriate to create discernible START signals and END signals from each of the retroreflective elements 18, which may consist of distinctive retroreflective bar code elements, as best illustrated in FIG. 6.
The position sensing system has at least three stationary retroreflective elements 18, as typified by elements 18a, 18b, and 18c in FIG. 1. Preferably, the retroreflective elements 18a, 18b, and 18c are spaced apart from each other around the periphery of the frame of reference and stationed at known coordinates in the two-dimensional frame of reference 10. In a preferred embodiment of the present invention, the retroreflective elements 18 are passive sensors, although active sensors may be used as well. With the passive sensor elements 18, the beam of light 16 is reflected back to the light transmitting and detecting means 14. Azimuth means (not shown), responsive to the reflection of the beam of light 16 from the retroreflective elements 18, continuously transmit angle signals, indicative of an azimuth angle at which the light transmitting and detecting means for receiving the beam of light is positioned with respect to each of the retroreflective elements 18, to a computer 22 of FIG. 5. The computer 22 includes a microprocessor, such as a Motorola 68030, having memory means for providing storage of software and data. A listing of exemplary software for performing the angle measurements in accordance with the present invention is included following the detailed description.
Since the reflection from one passive element 18 looks the same as the reflection from each of the other passive elements 18, it cannot be determined from the reflection itself which element 18 is being illuminated. Therefore, according to one aspect of the present invention, any or all of the retroreflective elements 18a, 18b, and 18c can have a unique bar code in order to differentiate one element from the others. The moment of illumination of each retroreflective element 18 is registered extremely accurately since that moment is decisive for determining the angle within the angle of rotation of 360 degrees. By recognizing the retroreflective elements 18a, 18b, and 18c individually, it is possible to assign the proper coordinates to each element 18, which is necessary for the calculation of the position of the point and the determination of the orientation of a position sensing system located at the point 12. Assigning a unique bar code to each element 18 distinguishes each of the elements 18a, 18b, and 18c from the others. The computer 22 includes a microprocessor, such as a Motorola 68030, having memory means for providing storage of software and data. A listing of exemplary software for performing the bar code recognition of the present invention is included following the detailed description.
Using the angle measurements and the recognized bar code patterns, the X-Y coordinates of the point 12 can be calculated by triangulation. The computer 22 includes a microprocessor, such as a Motorola 68030, having memory means for providing storage of software and data. A listing of exemplary software for performing the triangulation calculations of the present invention is included following the detailed description.
Referring now to FIG. 2, a side view of a housing 24 containing the light transmitting and detecting means 14 is shown. The light transmitting and detecting means 14 includes an electric motor 26 mounted to rotate shaft 28. A member 30, such as a code wheel, and a light diverting mirror 32 are mounted on the shaft 28. An index wheel 34 can also be included for providing a single reference pulse indicating each complete rotation of the shaft 28. A light source, such as solid state laser 20, directs the beam of light 16 onto the rotating mirror 32 so that a plane of rotation is created. In a preferred embodiment of the invention, a generally horizontal plane of rotation is created. However, any plane of rotation, including vertical, can be created. The retroreflective elements 18 are positioned in this plane. An advantage of the present invention is that a precisely horizontal or vertical plane is not essential for angle calculation. As a result, the system may be used either by an operator as a handheld device as the operator moves about the environment of interest, or mounted on vehicles and other equipment as the equipment moves about a given area.
When the rotating laser beam 16 strikes the retroreflective elements 18 during each revolution of the shaft 28, the beam of light 16 is reflected back to the light transmitting and detecting means 14 and can be transformed into an analog signal by a suitable detector, such as photodetector 36, and transmitted to a signal processing means 38 of FIG. 5, which outputs two digital signals. The light transmitting and detecting means 14 may include means for diverting and focusing the returning beam to the photodetector 36. In FIG. 2, the rotating mirror 32 diverts the light beam 16 toward a collimating lens 40, which lens 40 focuses the light beam 16 toward the photodetector 36. Theoretically, the moment in time that a retroreflective element 18 has been illuminated with respect to the complete time of rotation is related to its angle, depending on which retroreflective element 18 is being illuminated by the light beam 16, within a total angle of 360 degrees. However, this is only the case if the rotational speed of the beam 16 is extremely constant. Typically, the rotational speed of motor shaft 28 which causes the beam 16 to rotate is not perfectly constant and it is not possible to obtain a constant speed with the accuracy which is desired by the position sensing system of the present invention, especially in a mobile operation. Consequently, the position sensing system utilizes the motor 26 in conjunction with the member 30, supported by the dedicated hardware interface of FIG. 5 and controlled by software to achieve the desired accuracy. The computer 22, having a microprocessor such as a Motorola 68030, contains software for a main routine which controls the hardware interface of the position sensing system, an exemplary listing of which is included following the detailed description.
As shown in FIG. 3, the member or code wheel 30 has a plurality of angularly positioned elements, preferably apertures 42, spaced around its periphery which divide a revolution of the member 30 into a plurality of generally equal partial revolutions. The size and spacing of these apertures are greatly exaggerated in the drawing for clarity of illustration. For example, the code wheel 30 may divide a revolution into one thousand generally equal parts positioned approximately 0.36 degrees apart by spacing one thousand elements or apertures 42 around the periphery of the member 30. Although the distance between each adjacent pair of apertures 42 theoretically represents a movement of 0.36 degrees, misalignment of the member 30, misalignment of the center of the member 30 through which the shaft 28 extends, and manufacturing tolerances, cause deviations in the spacing of the elements 42. However, since these deviations remain constant once the light transmitting and detecting means 14 is assembled, the actual angular spacing between each element 42 in the member 30 can be determined extremely precisely by a software calibration table.
Calibration of the code wheel or member 30, preferably using software, improves accuracy by eliminating errors due to misalignments, deviations, and irregularities of the rotational speed of the motor 26. Any speed fluctuation of the motor 26 between two apertures 42, particularly when there are one thousand such apertures spaced around the periphery of the member 30, will be negligible. Consequently, it is possible to interpolate between an adjacent pair of apertures, such as 42a and 42b in FIG. 3, to determine an exact angle between the pair of apertures 42a and 42b, according to the equations:
Angle=∠42a+(Tm/Tcw)*(∠42b-∠42a)
where ∠42a is the measured angle of aperture 42a; Tm is the time elapsed between passage of the previous aperture, here aperture 42a, and the moment M in time that the reflecting light strikes the sensor or photodetector 36; and Tcw is the time it takes the code wheel 30 to move between element 42a and element 42b.
One method of calibrating the code wheel or member 30 is illustrated in FIG. 4 as a calibration system 44. To calibrate the member 30, the light transmitting and detecting means 14 containing the code wheel 30, is placed on a device 46 having an angularly positioned rotating surface 48 such that the spin axis of shaft 28 containing code wheel 30 is concentric to surface 48 of device 46, with the member 30 arbitrarily positioned. The computer 22 of FIG. 5 controls a stepper motor 50 associated with the surface 48 and determines the number of steps between each pair of adjacent elements 42 as the member 30 rotates. For instance, if one revolution of the member is defined as 360,000 steps, and the member 30 contains 1000 generally equally spaced elements 42, then each step would theoretically be expected to be equal to 0.001 degree, and each element 42 would be 0.36 degrees or 360 steps from each adjacent element 42. However, in reality, there will be deviations in the spacing of the elements 42. Therefore, the actual spacing between each adjacent pair of elements 42 is measured and can be stored in a calibration table, which table will remain accurate as long as the position sensing system of the present invention remains assembled.
Initially, in calibrating the member 30, a first element 42 receives a signal from a reference retroreflective element, and this first element 42 becomes an index element for purposes of calibration of the member 30. The calibration system 44 determines when the index and following elements 42 are in position to commence or end the counting of the steps between elements 42 by employing the interpolation equation from above. For the index element 42, Tcw equals zero and Tm equals zero. As the member 30 rotates toward the next adjacent element 42, Tm approaches zero and Tcw approaches 1. The moment in time when Tm is equal to zero and Tcw is equal to one, then the element 42 is in position to end the counting of steps between the index element and the first adjacent element. This pattern continues until the number of steps and, thus, the distance in degrees between, each pair of adjacent elements 42 has been determined. The calibrating system 44 is associated with the computer 22 which includes a microprocessor, such as a Motorola 68030, having a memory means for providing storage of software and data. A listing of exemplary software for performing the calibration of the member 30 of the present invention is included following the detailed description.
The position sensing system which combines the use of the code wheel 30 and the motor 26 is supported by a hardware interface 52, illustrated in FIG. 5. An event occurs every time an aperture 42 on the code wheel 30 passes, or a retroreflective element 18 commences or ends a reflection of the beam of light 16. Due to the high precision time measurements required between each adjacent pair of apertures 42, a reference clock 54 is used in keeping a record of an event. If an event occurred during this time, it is stored in a circuit 56, such as a 32 bit first-in- first-out circuit. The circuit 56 records the movement of the code wheel 30 at register 0. The actual element or aperture 42 which is currently passing is sensed at a member or code wheel pick up element 58 and counted by a member rotation counter 60. Each time the member 30 has completed a full rotation, an index pick up element 62 sends a signal to reset the member rotation counter 60. The member pick up element 58 and the index pick up element 62 comprise means for detecting movement of each of the elements 42 past a predetermined point as the member 30 rotates. In a preferred embodiment of the present invention, the pick up elements 58 and 62 comprise a light source paired with a photodetector element.
Signal processing means 38 detect when receiving optics 64, consisting of collimating lens 40 and photodetector 36, is either commencing receipt of the reflection of the light beam 16 or ending receipt of the reflection of the light beam 16 from the retroreflective elements 18 to the light transmitting and detecting means 14. Signal processing means 38 can transform the analog signal from photodetector 36 into two digital signals which are received at register 1 of circuit 56. The first digital signal represents a START signal which indicates if the reflection from retroreflector 18 is commencing the reflection of beam 16 from the retroreflective elements 18 to the light transmitting and detecting means 14, and the second digital signal is an END signal which indicates if the reflection is ending. Register 2 receives signals for measuring the time elapsing between the passage of the last aperture 42 and an event, which event may be the time Tm or the time Tcw shown in FIG. 3. A clock pulse counter 66 is reset at a clock pulse for counter 60 for each aperture 42, which counter 66 counts the time elapsing between the passage of each pair of adjacent elements 42. Information regarding the capacity of the circuit 56 is stored in register 3.
The circuit 56 stores the information received and provides an output signal 68 to the computer 22 which includes a microprocessor having memory means. The computer 22 is responsive to the output signal 68, to compute the coordinates of the position of the point 12 in the two-dimensional coordinate frame of reference 10. When the light transmitting and detecting means 14 is positioned at point 12, the computer 22 also computes the orientation of the light transmitting and detecting means 14 within the frame of reference 10.
When bar codes are used with the retroreflective elements 18, each element 18 may have a unique series of START and END signals, as illustrated in FIG. 6. In FIG. 6, retroreflector 18 receives a beam of light from light transmitting and detecting means 14. As the rotating beam 16 sweeps past the bar code of the retroreflective element 18, angle 1 starts a reflection back to the light transmitting and detecting means 14 which is detected by the signal processing means 38 of FIG. 5 and output as a START signal to the circuit 56. The reflection is momentarily stopped between angles 2 and 3, before starting again at angle 3. Similarly, the reflection stops between angles 4 and 5, but starts again at angle 5. Finally, the reflection from the retroreflector element 18 ends at angle 6, where the retroreflective element ends. Remaining retroreflective elements may have different bar code patterns which would send a unique sequence of START and END signals to the circuit 56.
A representative listing of exemplary software for performing angle measurements, performing triangulation calculations, controlling the hardware interface of the position sensing system, and performing calibration is as follows. ##SPC1##
Having described the invention in detail and by way of reference to preferred embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. | A position sensing system calculates the X-Y coordinates of a point using triangulation and determines the direction in which the point is moving. The triangulation calculation is based on the coordinates of at least three retroreflective elements spaced apart from each other around the periphery of a two-dimensional coordinate frame, and the measured angles between the lines projected radially outward from the point to each of the retroreflective elements. The accuracy of the measured angles is achieved by using a rotating member supported by dedicated hardware and controlled by software. The member rotates with a beam of light generated by a light transmitting and detecting device positionable at the point. The light transmitting and detecting device receives the beam of light reflected back from the retroreflective elements and generates an output signal in response thereto. A computer processes the output signals for use in calculating the X-Y position of the point and the orientation of the light transmitting and detecting device when it is positioned at the point. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to a flexible seal and, in particular, to a flexible seal that is ideally well suited for forming a fluid tight joint between a sewer pipe section and an opening into which the pipe section is fitted.
As disclosed in U.S. Pat. No. 3,787,061 an elastomeric tubular pipe seal is disclosed for joining a pipe section to a manhole riser. A receiving groove that compliments the outer contour of the seal is machined or otherwise formed in the pipe receiving opening of the riser and the seal is seated therein. The pipe section is inserted into the seal opening to complete the joint. A wound spring is contained within an opening formed in the seal which is designed to automatically load against the pipe to lock the seal thereto. The ends of the spring are brought out of the seal and positioned in an expanded chamber formed in the riser. During assembly, the spring ends are engaged by a special tool and the spring is expanded to permit the pipe to be inserted therein. The seal, however, sometimes is pinched or rolled against the sharp edges of the receiving groove during insertion and thus can become torn or otherwise damaged. The expansion of the spring within the limited confines of the opening is oftentimes difficult to achieve. Furthermore, the exposed parts of the spring are susceptible to attack by moisture and other corrosive materials that might be found in and about the seal which can lead to early failure of the seal.
In U.S. Pat. No. 3,958,313, a boot-like seal is disclosed that is also used to join a pipe section to a manhole riser. The boot, as described is a necked down, funnel shaped elastomeric member. In assembly, the neck of the boot is clamped by a metal collar to the pipe section and the wide end of the boot is passed into an opening formed in the riser. The boot is locked to the wall of the opening by means of a special band that includes a toggle joint which, when actuated, expands the band against the inside surface of the enlarged end of the boot. The toggle joins the two ends of the band and normally holds the band in a contracted condition. To expand the band, a closing force of about 1000 psi is exerted by a pneumatic tool directly against the toggle joint. Although the pressure closes the joint, it also destroys the toggle so that the band cannot be released without destroying the unit. Accordingly, if a fluid tight seal is not achieved on the first closure attempt, the seal must be removed from the assembly and replaced with a new unit which, of course, is relatively expensive. By the same token, if the seal must be removed for maintenance purposes or the like, it must be similarly replaced with a new unit. Boot type seals are also highly susceptible to being cut upon the sharp front edge of the riser opening if the connected pipe sections are moved or realigned in the opening. Sharp rocks, tools or other types of foreign objects can also easily penetrate the exposed section of the boot during back filling or excavating operations. Lastly, it should be noted that the expandable band of the seal unit is continually exposed to moisture and other corrosive substances carried by the sewer system and, unless fabricated of special high priced corrosion resistant materials, the bands will fail within a relatively short period of time.
SUMMARY OF THE INVENTION
It is a primary object of this invention to improve flexible pipe seals.
A further object of the present invention is to provide a pipe seal that can be easily installed and removed in assembly without the need of special tools.
A still further object of the present invention is to provide a flexible pipe seal that will permit a wide latitude in pipe alignment within a pipe receiving hole.
Another object of the present invention is to provide pipe seal that is fully contained within a receiving opening so that the seal cannot be punctured or otherwise damaged by sharp corners or foreign objects.
Yet another object of the present invention is to provide a flexible pipe seal that can be reused without destroying the integrity of the seal.
Still another object of the present invention is to minimize the effects of corrosion upon a fluid tight pipe seal.
These and other objects of the present invention are attained by means of a composite seal having a tubular elastomeric body section that encapsulates a resilient metal ring that can be collapsed inwardly on itself to reduce the outside diameter of the seal. The collapsed seal is inserted into a pipe receiving opening and then snapped back into sealing contact against the wall of the opening. The inner wall of the seal contains depending inwardly extended circular fins that are capable of engaging the outside surface of a pipe that is passed into the seal thereby establishing a fluid tight flexible joint within the opening.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of these and other objects of the invention, reference is had to the following detailed description of the invention which is to be read in association with the accompanying drawings, wherein:
FIG. 1 is a side elevation of a manhole riser showing a seal embodying the teachings of the present invention mounted therein so as to form a fluid tight joint between pipe sections and the riser;
FIG. 2 is an enlarged partial top plan view showing the seal illustrated in FIG. 1 positioned within one of the riser openings;
FIG. 3 is a front view of the riser opening showing a seal situated therein in a collapsed condition;
FIG. 4 is an enlarged section view through the seal shown in FIG. 3 which is taken along lines 4--4;
FIG. 5 is a side elevation showing the seal forming a joint between two connected pipe sections;
FIG. 6 is also a side elevation of a pipe section showing another embodiment of the invention wherein the seal is utilized to block the flow of fluids through the pipe; and
FIG. 7 is a view similar to FIG. 4 illustrating a segmented metal ring encapsulated in the body of the seal.
DESCRIPTION OF THE INVENTION
Turning initially to FIGS. 1-4, wherein like parts are identified by like numerals, there is shown a flexible seal, generally referenced 10, which embodies the teachings of the present invention. In this particular embodiment of the invention, the seal is employed to form a fluid tight joint between a sewer pipe section 13 and the wall of a pipe receiving opening 11 formed in a manhole riser 12. As best seen in FIGS. 1 and 2, the seal is entirely contained within a cylindrical opening that is cast or otherwise formed in the manhole riser. The present seal, due to its unique structure, does not require seating grooves or other complex and expensive retaining devices to be machined or mounted within the receiving opening that are normally required to prevent axial displacement of the seal in assembly. As will become evident from the disclosure below, the present seal can be easily positioned in the opening and snapped in place to provide a tight seal against the cylindrical surface of the riser opening without the need of special tools or complex mounting procedures. It should also be noted that the seal can also be easily removed and reinstalled without harm whereby the seal can be reused any number of times.
Seal 10 includes two main sections which are a tubular body section 15 that is formed of a rubber-like elastomeric material and a resilient metal ring 20 that is formed of a spring-like material that enables the ring to be collapsed inwardly upon itself and then snapped back into its normal circular posture. The ring is entirely encapsulated within the elastomeric body section to prevent the metal ring surfaces from being exposed to moisture or other corrosive substances that might attack the metal and cause premature failure of the seal. Accordingly, the seal will remain generally impervious to corrosion which can seriously harm other types of seals presently known and used in the art.
The body section of the seal has a central opening 16 formed therein that is capable of slidably receiving a pipe section. The outside diameter of the body section is slightly larger than the diameter of the riser opening. To mount the seal within the opening, the seal is initially collapsed as illustrated in FIG. 3. This is achieved by applying sufficient downward pressure against one quadrant of the seal to cause the ring, and thus the seal, to fold inwardly upon itself. A U-shaped indentation 35 is thus created in the seal structure which shrinks the outside diameter of the seal to a size that is slightly less than the diameter of the riser opening. As a result, the seal can be conveniently passed into the riser opening and centered therein.
To lock the seal in the cylindrical opening, the collapsed seal is snapped back into its normal circular posture by applying outward pressure against the indented section 35. Due to the interference fit provided between the outer periphery of the seal and the wall of the receiving opening, the elastomeric seal body is deformed against the receiving wall to provide a fluid tight seal. Under the influence of the ring a compressive force is applied against the wall which securely holds the seal in the opening. It has been found that by providing about 1/16 of an inch interference between the wall and the seal the seal will resist an extremely high axial load without being displaced or rolled within the opening. The axial loading that can be accommodated by the seal without shifting is considerably higher than the loads normally encountered under actual working conditions.
In practice, the ring is centered upon the axial centerline 17 of the body section so that a uniform distance d (FIG. 4) is maintained between the outside surface of the ring and the outside surface of the body. As a result of this construction, the ring delivers a uniform hold against the receiving wall about the entire outer periphery of the seal. The outer surface 21 of the body section is further provided with outwardly protruding circular ribs 22--22. The ribs, which preferably form a depending part of the seal body, are equally spaced along the length of the seal. When the seal is expanded within the opening the circular ribs are deformed individually against the wall and thus tend to accommodate any irregularities in the size of the wall opening as well as providing added holding power to the system.
Inwardly protruding circular fins also depend inwardly from the inside wall 23 of the body section. In the present embodiment of the invention, three fins are utilized. They include an intermediate fin 25 that is centrally located within the seal opening 16 and two end fins 26 and 27 that are located to either side of the intermediate fin. As best seen in FIG. 4, the radial length of the intermediate fin is greater than that of the two other fins. In all cases, however, the cylindrical opening of the fins is less than the outside diameter of the pipe section which is to be received within the seal opening so that each fin is capable of firmly and securely grasping the outer periphery of the pipe and forming a fluid tight seal thereagainst.
As can be seen, each fin is obliquely positioned within the seal opening so that it slants rearwardly from the front pipe receiving face 30 of the seal toward the rear seal face 31. By obliquely positioning the fins within the seal opening as shown, all the fins will deflect uniformly in one direction when the pipe section is passed into the seal. This, in turn, eliminates the danger of the fins being inadvertently twisted or rolled under during assembly. Slanting the fins rearwardly facilitates installation of the pipe section and also applies an axially directed holding force against the pipe that resists any tendency of the pipe to pull out of the seal once it is fitted therein. Stepping the length of the fins allows the seal to be compressively loaded and unloaded in stages between the pipe and the riser thereby further facilitating installation and removal of the pipe section. Deterioration of the seal is also minimized by placing all the rubber in a state of compression.
To insert a pipe section in the seal, the received end of the pipe is coated with a lubricant that will not adversely effect the seal rubber and the pipe is driven axially into the seal opening 16. Pipe sections have been driven into seated seals using power equipment without adversely effecting or displacing the seated seal within the opening. Once the pipe has been driven through the seal, the seal is compressed uniformly between the pipe and the riser and almost nothing can be done to impair the fluid tight integrity of the joint. Tests of the joint have demonstrated that the loaded seal can withstand relatively high hydrostatic heads without leakage.
To remove the seal, the pipe section is again lubricated and pulled out of the seal opening. A pry bar or any other similar type prying tool is inserted between the seal and wall of the opening and the seal is collapsed and removed from the opening. The removal procedures will not normally cause harm to the seal structure and the seal can therefore be reused as required thus providing a savings to the user.
Preferably, the axial length of the seal is less than that of the receiving opening so that the seal is fully contained within the opening. The contained seal will not be exposed to the sharp corner edges of the opening and, as a result, the seal can not be cut or punctured in the event the pipe section is axially displaced after assembly. Typically, the receiving hole is formed to provide about a one to two inch clearance between the wall of the opening and the outside surface of the pipe. A seal having an axial length of about four inches will provide sufficient flexibility with this type of clearance to permit the pipe to be deflected about 12° off axis without adversely affecting the integrity of the seal. Because the seal does not project beyond the ends of the riser opening, it is shielded from foreign objects which might otherwise penetrate the seal.
FIG. 5 shows the present seal 10 being used to form a fluid tight joint between two sewer pipe sections 40 and 41. The seal is sized so that it can be slipped in a collapsed condition into the recessed shoulder 43 formed in the end of pipe 40. The seal is snapped into place as explained above and the reduced nose flange 45 of the second pipe 41 is inserted into the seal to establish a secure but flexible joint. As should be evident from the disclosure above, the seal can be easily removed from the pipe and later reused thus realizing a considerable savings when compared to destructable pipe seals presently known and used in the art.
FIG. 6 shows another embodiment of the invention in which the center portion of seal body 15 is completely closed by an elastomeric diaphragm 48 that extends across the seal opening. Preferably the diaphragm is cast as an integral part of the seal body so that the seal and diaphragm form a single piece unit. In this embodiment, the seal is snapped into sealing contact against the interior wall of a pipe 49 to temporarily block the flow of fluids through the pipe. Here again the reusable seal can be easily installed and removed to provide a temporary block in the line which is particularly useful when repairs on the system are being made.
The seal shown in FIG. 7 is similar to that shown in FIG. 3. The continuous ring, however, has been replaced by a series of coaligned bands 50--50 which provide for the same snap in function as the single bands. The multiband arrangement is useful for applying a more uniform holding pressure against a wall opening that is slightly tapered out of round or misaligned during the forming process. The separate bands individually compensate for any irregularities in the opening wall and combine to provide for a tight seal. The outer surface 52 of the body section 15 contains a number of grooves 51--51 which allow the incompressible rubber body to deform when the seal is compressed against the opening. By using grooves in place of the previously noted deformable ribs, a generally smooth cylindrical outer surface is presented to the inner wall of the opening. The smooth outer surface also allows an elastomeric tubular sleeve 55 to be slipped over the seal as shown in FIG. 7. Oftentimes, the holes formed in a manhole riser or the like will be oversized due to faulty fabrication procedures, improper machining operations or the use of a damaged forming tool. When this occurs, the seal body cannot lock securely against the opening and leakage will result. By placing the elastomeric sleeve 55 over the seal body, the working diameter of the seal is increased to compensate for the increased size of the opening.
While this invention has been described with reference to the details as set forth above, it is not limited to the specific structure as disclosed and the invention is intended to cover any modifications or changes as may come within the scope of the following claims. The seal, for example, can be used as a wall thimble for sealing any type of conduit passing into a structure. | This invention relates to a composite flexible seal for providing a fluid tight joint between a pipe section and the inside surface of a receiving opening. The seal includes a slightly elongated tubular body formed of an elastomeric material and a spring-like metal snap ring encapsulated within the body. The ring can be collapsed inwardly upon iself reducing the outside diameter of the body and allowing the seal to be inserted into the receiving opening. Once situated in the opening the ring is expanded causing the seal to be locked in fluid tight contact against the wall of the opening. A pipe section is inserted into the seal opening to complete the joint. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
The teaching of U.S. application Ser. No. 09/356,183 filed on the same day herewith entitled, “SYSTEM AND METHOD FOR MANAGING FILES IN A DISTRIBUTED SYSTEM USING PRIORITIZATION” to Chess et al. is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to the management of files in a distributed system. More particularly, this invention relates to efficiently managing the transmission of files in a distributed system.
BACKGROUND OF THE INVENTION
In many distributed systems, units of digital data that require processing such as files, queries, or other requests for service (hereinafter “files”) pass through a number of nodes during processing. These nodes are typically processes running on different machines (e.g., servers, workstations, desktop computers, laptops, pervasive systems, etc.) in the network. However, nodes can be logical processes, some of which run in the same machine. Each node may perform some, all or none of the processing required for a given file, and if further processing is required, it may pass the file along to another node. When a file is fully processed, typically the result is routed back toward the originator of the query, and/or some other recipient(s). Each node contains a certain amount of data that is used in processing files.
Congestion occurs in a distributed system when one or more nodes or communication links between nodes become too busy to handle the traffic destined for them. Either a node cannot process files as fast as they arrive, or a communication link cannot transmit files from one node to another fast enough to prevent queues from building up. When part of a system is congested, there will be files which are awaiting processing and/or transmission. Therefore, in a system in which there is a sequence or hierarchy of nodes through which a file is directed to flow, the earlier in the sequence of nodes a file can be fully processed and the results determined, the fewer nodes the file will have to pass through during processing, and the less severe congestion will be.
One particular distributed system in which congestion can be a severe problem is the computer virus “immune system” as described in Kephart et al., “Fighting Computer Viruses,” Scientific American, November 1997, hereby incorporated by reference. In an “immune system,” personal computers (PCs) are connected by a network to a central computer which analyzes viruses. Each PC incorporates a monitoring program which uses a variety of heuristics to infer that a virus may be present. The PCs, upon discovery of a suspect file, send a copy of the file to the central computer for analysis. After manual analysis by operators, the central computer eventually is instructed to transmit a prescription for verifying and removing the virus (assuming one is found). The prescription may be sent to one or more of the PCs as an update to be applied to databases maintained on those machines.
In a system in which a substantial number of PCs are connected to the network, suspect files may become queued up waiting for transmission to the central computer (or to a next higher level in a multi-level distributed system). For example, in distributed system 100 of FIG. 1, the units of digital data passed from node to node are files which are suspected of containing viruses, Trojan horses, worms or other types of malicious code. The nodes (which can be data processing systems such as disclosed in FIG. 1 a of U.S. Pat. No. 5,440,723, (hereinafter “'723 patent”) hereby incorporated by reference, or processes running therewithin) are organized in a hierarchy, such that suspect files found on one or more client machines 110 are first passed to one or more administrator machines 120 , at which limited processing takes place, then passed to one or more gateway machines 130 , and finally passed to a central analysis center 140 , if necessary. Just as more than one gateway machine can be (and are preferably) utilized in this system, several analysis centers can be utilized for this function, if need be. Furthermore, the nodes can be logical so that a file determined to be suspect by a human user or by a process within a client computer 110 can be forwarded to another process (node) within the client computer 110 . Indeed, there can be multiple logical nodes within any components of the distributed computer system 100 , including the analysis center 140 . In such systems, during the active spreading of a new fast-spreading virus, many suspect file copies containing the same virus code are likely to be submitted by the client machines 110 in a small period of time. This would cause serious congestion throughout the system 100 .
Simple caching utilized in present systems will not be sufficient to prevent congestion, because any given client machine 110 or administrator machine 120 is unlikely to see a wide enough variety of files. That is, caching only the result of prior analysis of its own submitted files will not prevent enough congestion. Only by being apprised of the results of files submitted by others, and of general results (i.e. new virus definitions that apply to a given virus in any host file), will the analysis center be sufficiently shielded from redundant requests.
As indicated hereinabove, immune systems provide for updates to local databases which are utilized to eliminate the need to forward files or requests up the system hierarchy. However, these updates are initiated only after manual analysis or processing by a human operator at the analysis center. This is insufficient in an environment in which a substantial number of files or requests are generated in sometimes short periods of time. Furthermore, present systems have no method of managing the inevitable backlog of queued files or requests that must be forwarded up the hierarchy to another node
Finally, current methods of speeding up components such as Web browsing are not designed to handle the sudden massive congestion that can be caused by a piece of replicating malicious code.
Therefore, there is a need for a system and method to efficiently manage the transmission of files or other units of digital data up the hierarchy from node to node so as to reduce the number of redundant files that are transmitted through the system.
Specifically, there is a need for a system and method for filtering or eliminating the necessity for further transmission of a file to another node by utilizing information which is updated by automatic processing at local or remote nodes.
Furthermore, there is a need for a system and method for prioritizing the files which are not filtered for transmission to other nodes, including identifying the order of transmission of these files and a need for a system and method for updating the data necessary to manage these decisions in a manual or automatic manner, as required.
SUMMARY OF THE INVENTION
The present invention is a system and method for increasing the efficiency of distributed systems and reducing congestion, by using the results of processing at a node to update the data used in processing at that and/or other nodes sometime in the future. Specifically, the present invention provides, in a network-connected distributed system including two or more nodes through which digital data flow, one or more of the nodes adapted to process the digital data, a method for efficiently managing the transmission of units of digital data from node to node, the method including the steps of: receiving, at one of the one or more nodes, one or more units of digital data first transmitted by an originating node; filtering out sufficiently processed units of the digital data based on filtering information; transmitting, to the originating node and/or other nodes, filtered results relating to the sufficiently processed units; queuing, for processing at other nodes, unfiltered units of the digital data which are not filtered out; and updating the filtering information according to results of automatic processing performed in and received from the one of the one or more nodes and/or other nodes in the system.
In one embodiment, the distributed system can include nodes for the reporting and analysis of incorrect or buggy software, the units of digital data can include files, and the transmitting step can include the step of returning updated information on bugs and fixes to the originating node and/or to other nodes.
In another embodiment, it is preferable that the distributed system includes a system for the analysis of complex geographically-based data such as satellite images, the units of digital data include requests for information about a particular geographical area, and the transmitting step includes the step of returning updated information on areas which have already been analyzed in response to prior queries to the originating node and/or to other nodes.
In yet another embodiment, the distributed system includes a system for the computation of integrals, and the units of digital data include queries of formulae to be integrated.
The units of digital data can include queries or files. In one embodiment where this is the case, the distributed system includes a computer protection system, the units of digital data include files and/or checksums of files which are suspected to contain malicious code and the transmitting step includes the step of returning updated protection information to the originating node and/or to other nodes. The malicious code can include computer viruses, worms or Trojan Horses.
Preferably, the filtering step includes the steps of determining whether a file is identical to a known non-malicious file, and identifying the file as sufficiently processed in response to the determining step. The updating step preferably includes the steps of receiving, from other nodes in the system, modification detection codes of files that have been determined to be non-malicious, and adding the modification detection codes to the filtering information.
The filtering step can also include the steps of determining whether a file cannot contain malicious code because it does not contain any code at all, and identifying the file as sufficiently processed in response to the determining step.
The filtering step can optionally include the steps of determining whether a file cannot contain malicious code because it does not contain enough code to constitute even the smallest anticipated virus; and identifying the file as sufficiently processed in response to the determining step.
Finally, the filtering step may include the steps of determining whether a file contains known malicious code that is correctly handled by an existing protection definition, and identifying the file as sufficiently processed in response to the determining step. In this case, the updating step preferably includes the steps of receiving, from other nodes, protection definitions for malicious code that has been analyzed, and adding the definitions to the filtering information.
In all cases, it is preferable that the updating step includes the step of re-executing the filtering step to apply the updated filtering information to the queued units of the digital data.
The units of digital data can also include queries including a database version of the originating node and a request for an updated version, if available, wherein the filtering step includes the step of determining whether the one of the one or more nodes has a more recent database version and wherein the updating step includes the step of updating originating filtering information of the originating node and/or other nodes of the system that are likely to have older versions. The units of digital data can include queries including a database version of the originating node and a request for a updated version, if available, and the updating step can include the step of updating the originating filtering information of the originating node and/or other nodes of the system that are likely to have older versions. The database version preferably corresponds to the filtering information
In another embodiment, the distributed system preferably includes a computer protection system, the units of digital data include samples of undesirable textual messages and the transmitting step includes the step of returning updated protection information to the originating node and/or to other nodes.
Another embodiment includes, in a network-connected distributed computer protection system including a plurality of nodes through which digital data flow, one or more of the nodes adapted to process the digital data, a method for efficiently managing the transmission of suspect files from node to node, the method including the steps of receiving, at one of the one or more nodes, a checksum of a suspect file transmitted by an originating node; if a checksum match is found based on filtering information, identifying the suspect file as sufficiently processed; else causing the receiving, at the one or more nodes, of the suspect file; filtering out sufficiently processed units of the digital data based on the filtering information; transmitting, to the originating node and/or other nodes, filtered results relating to the sufficiently processed files; queuing, for processing at other nodes, unfiltered files which are not filtered out; and updating the filtering information according to results of automatic processing performed in and received from the one of the one or more nodes and/or other nodes in the system.
Another aspect of the invention includes a system for efficiently managing the transmission of units of digital data from node to node in a distributed network comprising a plurality of nodes, at least one of the nodes including a filter adapted to filter out sufficiently processed units of the digital data based on filtering information; the filtering information being updatable according to results of automatic processing performed in and received from one of the plurality of nodes in the system.
Finally, another embodiment of the present invention includes, in a network-connected distributed system including a plurality of nodes through which digital data flow, one or more of the nodes adapted to process the digital data, a method for efficiently managing the transmission of units of digital data from node to node, the method including the steps of receiving, at one of the one or more nodes, units of digital data first transmitted by an originating node; filtering out sufficiently processed units of the digital data based on filtering information; transmitting, to the originating node and/or other nodes, filtered results relating to the sufficiently processed units; queuing, for processing at other nodes, unfiltered units of the digital data which are not filtered out; prioritizing the unfiltered units of digital data for transmission to a next node based on prioritizing information; and updating the filtering information and the prioritizing information according to results of automatic processing performed in and received from the one of the one or more nodes and/or other nodes in the system. The updating step optionally comprises the step of re-executing the filtering step and/or the prioritizing step to apply the updated filtering and prioritizing information to the queued units of for the digital data. The units of digital data can comprise queries or files.
Also, a system for efficiently managing the transmission of units of digital data from node to node in a distributed network includes a plurality of nodes, at least one of the nodes including a filter adapted to filter out sufficiently processed units of the digital data based on filtering information, the filtering information being updatable according to results of automatic processing performed in and received from one of the plurality of nodes in the system; and a prioritizer adapted to prioritize units of the digital data queued for transmission to another node based on prioritizing information, the prioritizing information being updatable according to results of processing performed in and received from one of the plurality of nodes in the system.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be understood by reference to the drawing, wherein:
FIG. 1 is a schematic diagram of a distributed computer system within which the present invention can execute;
FIG. 2 is a block diagram of information stored on a node of the distributed computer system of FIG. 1 in accordance with an embodiment of the present invention;
FIG. 3 is a flow diagram of a method of an embodiment of the present invention;
FIG. 4 is a flow diagram of another method of an embodiment of the present invention; and
FIG. 5 is a flow diagram of yet another method of an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In an immune system embodiment of the present invention, at each stage of the system 100 of FIG. 1, certain suspect files can be determined to be either non-malicious, or to contain a known piece of malicious code which can be detected (and eventually repaired) using a known description dataset. As shown in FIG. 2, each node 200 , including the analysis center 140 , contains or has access to a database 210 of modification detection codes (e.g., digital fingerprints or checksums) that uniquely identify files known to be non-malicious, a set of description datasets 220 (or protection definitions) describing how to detect and eliminate known malicious code entities (viruses, Trojan horses, worms, etc.), and instructions 230 for recognizing files that cannot contain malicious code because they contain no code at all (visual images, audio recordings, etc.) or so little code that no plausible virus would fit therein.
As shown in FIG. 3, several steps are taken in accordance with an embodiment of the present invention when a file arrives at a node in step 310 . First, in step 320 , the file is checked against the database 210 of known non-malicious files. If the file is identified as a known non-malicious file, a “clean” result is returned, in step 325 , to the previous node from where it was last transmitted, as well as to other subsidiary nodes, including the original node which suspected a problem. If, in step 320 , no match is found, the process continues in step 330 . In step 330 , the file is checked against the instructions 230 for recognizing files that contain no code. If a match is found in step 330 , the process continues in step 325 as indicated hereinabove. If no match is found, the process continues in step 340 . In step 340 , the file is compared to the database 220 of malicious-code descriptions. If the file is identified as including known malicious code, then, in step 335 , the results are returned to the previous node (as well as to other subsidiary nodes, including the original node which suspected a problem), indicating that the file is malicious, what particular malicious code entity (e.g., virus name) it contains, as well as the description dataset 220 that can be used to detect and eliminate the malicious code (and repair other infected files, if any). If a match is not found, it is determined, in step 350 , whether the present node is located within or associated with an analysis center 140 . If the node is not located within or associated with an analysis center 140 , the file is queued for transmission to a node in the next (higher) level of the hierarchy, in step 355 and the process continues in FIG. 4 .
Optionally, the system can be designed such that when a file is to be transmitted to another node up the hierarchy, a checksum of the file is actually sent in advance of the actual file. The receiving node can therefore search its databases for the file's checksum to determine whether the file has been previously analyzed. If a match is found, the results from the previous analysis are returned to the originating nodes and/or other nodes on the system. This embodiment would eliminate the need to transmit the file's content in many cases, thus avoiding unnecessary work.
However, if a file reaches a node of an analysis center 140 , the file is subjected, in step 370 , to rigorous analysis, including (depending on the type of file it is) some combination of execution in a simulated environment, execution on specially-instrumented machines or machine emulators which are prepared with “goat” or decoy files (e.g., files of the same basic type as the suspect file as determined by classification discussed hereinbelow which can be infected by any virus within the suspect file when executed), static analysis, processes disclosed in the '723 patent and other measures known to those skilled in the art. This analysis can, but need not, involve help from human analysts, if necessary. When the analysis process is completed, the file is determined, in step 380 , to be either non-malicious (with some high probability), or to contain a new and now-known malicious-code entity. If malicious code is not found, the process continues in step 385 , in which an update to known non-malicious database 210 is created. The update is first applied to the analysis center's database and then it is packaged for transmission down the hierarchy of nodes. The method continues in step 325 as indicated hereinabove. If malicious code is determined to be present, the process continues in step 390 , in which an update to the known malicious description database 200 is created. This update is also applied to the analysis center's database, then packaged for transmission down the hierarchy of nodes. The method continues in step 335 as indicated hereinabove.
There are several ways in which the updates can be distributed downstream in the distributed system. Preferably, after updating its own database, the analysis center sends the update to the problem-originating node (and associated machine) and to all other nodes in the path(s) therebetween. Optionally, the update can be transmitted to other nodes under the analysis center's “umbrella.” For instance, the update can be sent to the high-level gateway machines 130 , so that the next time another copy of this file (in the case of non-malicious files) or any file containing this particular malicious code (in the case of malicious code) is received at the gateway, it may be dealt with without requiring the resources of the analysis center. The gateways in turn may distribute this update to administrator systems 120 (e.g., in companies which have paid for instant updates) and the administrative systems may distribute the update to the client machines that they serve.
In one embodiment of the present invention, shown in FIG. 4, a file destined to be queued for transmission in step 355 is processed. First, in step 400 , it is determined whether there are any files presently in the queue. If no files are present, the file is transmitted to the next higher node in the hierarchy, in step 402 . If other files exist in the queue, the file is added to the queue in step 405 . Next, in step 410 , the queued files are classified according to their basic type or by the type of digital object they contain. Possible classifications include but are not limited to 16-bit binary executable, 32-bit binary executable, boot record image, word-processing document, spreadsheet, etc. Within each classification (or type), the files are clustered, in step 420 , by using a code-similarity metric to determine the similarity of the possibly-malicious code in each file to the corresponding code in the other files, and grouping together those files which are closest according to the metric. One effective code similarity metric works as follows. For each file, the probably-malicious portion of the file is identified by appropriate heuristics. For instance, if a file was identified as probably containing malicious code via a generic-disinfection algorithm like that taught in U.S. Pat. No. 5,613,002, hereby incorporated by reference, then the auxiliary information accompanying the file indicates where the probably-malicious code resides within the file. Several heuristics for detecting probably-malicious code other than generic disinfection are known by those skilled in the art, some of them tailored to binary executables, and others to either boot record images, word-processing documents, spread sheets, or other types of hosts that can carry malicious code. Most of these heuristics are capable of determining exactly or approximately the location of the probably-malicious code, and this information can similarly be incorporated into auxiliary information accompanying the file. If such auxiliary information is not supplied with the file, the appropriate heuristic or heuristics could potentially be run at the node to supply that information.
For each sample, tally all n-grams of a given size N (say N=5) that occur within the probably-malicious regions. Next apply some squashing function F to the tallies, e.g., F(t)=max(t,2). Then each file is represented by a resulting (squashed) tally vector. The vectors may then be adjusted to take into account the expected N-gram frequencies within normal non-malicious code, and to give greater weight to unusually common or uncommon N-grams. Next, the similarity is computed as a normalized dot product for each pair of vectors. Regard a pair of files as “associated” if the dot product exceeds a given threshold, and then divide the files into clusters by performing the transitive closure of the association relation. The threshold may be fixed at some particular value, or the algorithm may be applied with multiple thresholds, until one is found that yields a desired number of clusters.
Once the files have been grouped according to how likely they are to contain the same malicious code, one or more representative files are chosen from each cluster, in step 430 . A variety of possible methods exist for choosing a representative file. One simple, but effective, heuristic which also saves network bandwidth consists of simply choosing the smallest file from each group. Other possibilities include sending that file which seems likely to be easiest to analyze (which will often be the smallest, but not always), choosing a file which seems to be the result of malicious-code infection of one of a set of known non-malicious files, or choosing that file which compresses the best. In step 440 , those representative files are queued to be transmitted prior to the other members of each cluster. In a preferred embodiment, the representative files themselves are prioritized according to the expected cost-effectiveness of analyzing each one. For instance, the representative of the largest cluster might be sent first, since that cluster is likely to represent the most widespread malicious code entity. The process continues in step 450 in which the availability of one or more channels (to other nodes) is determined. If not available, the channel is checked once again after a period of time. If the channel is available (or becomes available), the first file in the queue is transmitted to the next higher node in the hierarchy, in step 460 .
FIG. 5 shows the process of an embodiment of the present invention after a database update is received at a node. When a node receives a database update, as in steps 390 and 335 , it updates, in step 510 , the relevant databases so that files received in the future will be checked for matches against the new (as well as preexisting, but still valid) knowledge. The node also checks all files that are queued for transmission to the next node, in step 520 . If any matches are found, those files are dequeued, and processed as follows. In step 530 , each queued file is compared to the non-malicious file database. If a match is found, the file is dequeued and the clean result is returned to the previous node in step 540 . If no match is found, the queued file is checked against the dataset for malicious code in step 550 . If a match is found, the file is dequeued and the virus name and description dataset is returned to the previous node in step 560 . Additionally, if any other files still in the queue are in the same cluster as a file for which a match is found on the updated malicious-code database, those files are moved up in transmission priority in step 565 , since they contain code which is similar to known malicious code, and are therefore more likely to be malicious themselves. If no match is found, the queued file is left in the queue in step 570 .
This is important, because in the case of a sudden “outbreak” of a replicating malicious-code entity such as a network worm, a very large number of copies of the malicious code may be found on client machines and sent into the distributed system. Since the processing done by an analysis center 140 is resource-intensive, it would bog down the entire system if every one of those copies were to be processed by the analysis center 140 . When the present invention is used, only one copy of the new entity is processed by an analysis center 140 , and as the database updates travel downward through the network, the many copies of the entity that are queued for transmission upward will be dequeued and processed lower down, thereby increasing the efficiency of the system. Once the updates have traveled all the way to the client machines 110 , clients encountering the new entity will be able to deal with it themselves, without involving any other nodes of the system.
In an alternate embodiment of the present invention, the unit of digital data is a type of query that does not include a suspected malicious file, but only serves to facilitate the distribution of database updates in, e.g., an anti-virus system. In this embodiment, a node may send, to another node up the hierarchy, a query which states the current version of one or more databases that the node possesses, and requests that any updates that have occurred since that version be transmitted to it. Such queries can be handled by the first node that receives the query and has a more recent version. Optionally, such queries can be transmitted to the analysis center at every instance. When a node satisfies such a query, it can send the newer updates not only to the node that originated the query, but also to any other nodes in the hierarchy that are known, either certainly or heuristically, to be lacking those updates.
A further embodiment of the present invention relates to a distributed electronic mail (“e-mail”) system. In this embodiment, the distributed system comprises a system for filtering out undesirable mail from client's inboxes. The units of digital data are samples of undesirable textual messages (e.g., spam, hoaxes, etc.). Updating the databases of intermediate nodes would create more efficient system for preventing the proliferation of such undesirable messages.
Another embodiment of the present invention relates to a distributed system for facilitating sophisticated analysis of satellite data. In this embodiment, the distributed system comprises a system for the analysis of complex geographically-based data such as satellite images. The units of digital data are preferably requests (queries) for information about a particular geographical area. The updating of the databases serves to increase the efficiency with which the system processes the queries about areas which already have been analyzed in response to prior queries.
Another embodiment of the present invention relates to the computation of expensive integrals. In this embodiment, the distributed system is a system for the computation of integrals. The units of digital data are queries of formulae to be integrated.
Now that the invention has been described by way of a preferred embodiment, various modifications and improvements will occur to those of skill in the art. For instance, any distributed system in which there exists relatively expensive back-end processing (e.g., server processing) and intermediary nodes capable of filtering or prioritizing and where, once the back-end has processed a particular request from a client, it is likely that one or more other clients will make the same request at some point, can benefit from the present invention by updating the other intermediary nodes in the network with the result of the processing. Thus, it should be understood that the preferred embodiment is provided as an example and not as a limitation. The scope of the invention is defined by the appended claims. | In a network-connected distributed system including nodes through which digital data flow, one or more of the nodes adapted to process the digital data, a method for efficiently managing the transmission of units of digital data from node to node, includes the steps of receiving, at one of the one or more nodes, units of digital data first transmitted by an originating node; filtering out sufficiently processed units of the digital data based on filtering information; transmitting, to the originating node and/or other nodes, filtered results relating to the sufficiently processed units; queuing, for processing at other nodes, unfiltered units of the digital data which are not filtered out; and updating the filtering information according to results of automatic processing performed in and received from the one of the one or more nodes and/or other nodes in the system. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a sensor, in particular a magnetostrictive or magnetoelastic sensor, having at least one core element which is composed of a ferromagnetic material and is at least partially surrounded by at least one coil.
Sensors such as these are known and available commercially in a very wide range of forms and configurations. They are primarily used for measuring forces, force changes and torques, and for determining changes in them.
They are frequently used as sensors for measuring torques in shafts, or as force pick-ups.
By way of example, DE 38 19 083 A1 describes a magnetoelastic force measurement apparatus, with an annular coil being fitted to a pressure ring body. In this case, a likewise magnetostrictive tension sleeve body with a corresponding annular coil is arranged coaxially in the pressure ring body, so that, when force is introduced, one body is stressed in compression, and the other body is stressed in tension. This has the disadvantage that the corresponding coaxial configuration means that the sensor is difficult to use and to operate. In particular, it cannot be designed to be very small, and thus cannot be used universally.
Furthermore, its design is complex, and it is expensive to produce.
DE 196 05 096 discloses a torque sensor and a stress detection element, in which a core component having a magnetostrictive winding is provided on a rotating shaft, in particular bridging a gap.
This has the disadvantage that such a torque sensor can be provided only for specific shafts, and must be specifically matched to each component.
SUMMARY OF THE INVENTION
The present invention is based on the object of providing a sensor of the type mentioned initially, which overcomes said disadvantages and by means of which it is possible to determine a force and/or a torque as well as any change in a simple and cost-effective manner. In this case, it is intended to be possible to use the sensor and, in particular, its components permanently in the widest possible range of environments.
Furthermore, the installation size and production costs are intended to be reduced, with the life at the same time extend and with the aim at the same time improving the reliability, with greater accuracy.
In order to achieve this object, the at least one core element is inserted into a housing on which tension and/or compression forces act for force and/or torque determination.
In the case of the present invention, it is of elementary importance that all the components of the sensor, such as core elements and coil elements, are inserted into a housing. Appropriate forces which are to be determined as well as a magnetic return path can then act on the housing by virtue of the guidance of the magnetic field or torques. A magnetic return path can also be provided via the housing and the encapsulation of the coil elements. In consequence, the sensor and, in particular, its components are protected. At the same time, such a sensor ensures universal use in widely differing technical fields.
A magnetostrictive material is preferably used as the core element. The material Terfenol-D has been found to be particularly suitable. The magnetic characteristics of this material vary when a force acts on it. This change in the magnetic field can be determined by means of a magnetic alternating field, which is applied by means of the coils around the core element. In consequence, the coil has a specific impedance, which determines the current that flows through the coil. If a specific force acts on the core element, then its magnetic characteristics, essentially its relative permeability, change. This change influences the magnetic field and hence the impedance. These changes can be measured as currents or voltages.
In order to measure compression and/or tension forces at the same time, it has been found to be particularly advantageous to insert the core element or the core elements into the housing such that they are prestressed. This allows compression and/or tension forces to be determined in a simple and cost-effective manner. There is therefore no need for any autonomous or independent protection for this purpose.
Furthermore it has been found to be particularly advantageous to insert two core elements, which are arranged in a row, with an intermediate piece between them into a housing, the two core elements each being surrounded by at least one coil. In this case, the housing is sealed tight on the outside.
Force transmitting elements project from the outside inward through the housing to the intermediate piece, and can in this way apply compression and/or tension forces to the core elements.
If one of the two core elements has pressure applied to it, then the opposite, other core element necessarily has tension applied to it.
In consequence, different voltages can be produced in the individual coils, which allow exact conclusions with regard to the forces or torques acting on them.
The idea of the present invention also includes the sensor having at least one associated temperature sensor so that a correction factor can be influenced during operation if, for example, the environment of a sensor has a temperature-dependent response and a temperature change occurs, for example, in the drive. It is thus possible to use a temperature to pre-set a measurement variable, in order to increase the accuracy of the sensor element.
In addition, in a further exemplary embodiment of the present invention, the intention is to provide an individual core element with at least one coil, with covering elements resting against the end faces of the core element. A housing is formed by means of an appropriate cylinder. The cylinder preferably has thin walls. Appropriate compression forces can act directly on the encapsulated core element with the coil, with a voltage change being possible, so that it is also possible to determine the force and/or force change. With this arrangement, it is also possible to insert the core element between the covering elements such that it is prestressed so that tension forces can also act here.
Overall, the present invention provides a sensor which can be produced with very small installed sizes and by means of which exact measurement results can be achieved. In this case, the sensor can be used and installed universally in any desired machine elements without it having to be specified and modified specifically for each installation.
BRIEF DESCRIPTION OF THE INVENTION
Further advantages, features and details of the invention will become evident from the following description of preferred exemplary embodiments and from the drawings, in which:
FIG. 1 shows a schematically illustrated longitudinal cross section through a sensor according to the invention for determining tension and/or compression forces;
FIG. 2 shows a schematically illustrated longitudinal cross section through a further exemplary embodiment of a sensor according to the invention;
FIG. 3 shows one possible arrangement of individual sensors as shown in FIG. 2 for determining forces and/or torques;
FIG. 4 shows a schematically illustrated longitudinal cross section through a further exemplary embodiment of the sensor illustrated in FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1 , a sensor R 1 according to the invention has a housing 1 , which, in the preferred exemplary embodiment, comprises a cylinder 2 whose end faces can be closed by covering elements 3 . Attachment elements 4 , which are represented by dashed lines, can connect the covering element 3 and the cylinder 2 to one another firmly or such that they can be detached again.
Sealing elements or the like (which are not illustrated here in any more detail) can be provided in order to close the housing 1 such that it is completely tightly sealed.
In this case, a welded joint or a screwed connection between the covering element 3 and the cylinder 2 are also intended to be covered within the scope of the invention. The invention is not restricted in this area.
Each covering element 3 or only one of the two covering elements 3 has an associated threaded pin 5 , preferably centrally, which, if required, can be fixed in any desired position via a locking nut (which is not illustrated here).
An intermediate piece 6 is inserted, such that it can move axially, in the housing 1 with pressure being applied to it. The intermediate piece 6 is provided with holding steps 7 , which are preferably arranged centrally. A core element 8 . 1 , 8 . 2 composed of ferromagnetic material is in each case inserted on both sides, adjacent to the intermediate piece 6 between the holding steps 7 and the threaded pin 5 .
In the preferred exemplary embodiment, a cylindrical pin 9 is in each case inserted between the core element 8 . 1 , 8 . 2 and the threaded pin 5 .
The threaded pin 5 can be screwed into the housing 1 in very small steps by turning the threaded pin 5 in the covering element 3 . This allows prestessing to be applied to the cylindrical pin 9 and, in particular, to the core elements 8 . 1 , 8 . 2 .
The core elements 8 . 1 , 8 . 2 are surrounded by respective coils 10 . 1 , 10 . 2 . The coils 10 . 1 , 10 . 2 are preferably kept at a short distance from the intermediate piece 6 and from the core elements 8 . 1 , 8 . 2 themselves via coil formers 11 , so that a slight, infinitesimal axial movement of the core elements 8 . 1 , 8 . 2 and of the intermediate piece 6 is possible.
The intermediate piece 6 is preferably guided within a sleeve 12 .
At the same time the sleeve 12 in each case forms an end-face stop for the two coils 10 . 1 , 10 . 2 and for the coil former 11 , so that their end faces are in each case kept at a distance from one another in the housing 1 , while they rest against the covering elements 3 and are supported there.
Force transmitting elements 13 act through an opening 14 in the housing 1 on the intermediate piece 6 , so that a force F, in the form of a tension force and/or a compression force, can be applied to them from the outside, in particular from outside the housing 1 . In particular, this allows a specific force F to be applied as a compression force and/or as a tension force to the sensor R 1 , and to be determined by comparison of the coil voltages.
Appropriate opposing bearings, which are not shown here, can absorb the force F on the end faces in the region of the covering elements 3 . Thus, for example, a force F can be introduced into the sensor by means of a sleeve or a similar element.
A voltage is applied to both coils 10 . 1 , 10 . 2 , which is changed by a change in the magnetic field, due to a change in the core element 8 . 1 , 8 . 2 caused by the application of pressure and/or tension. This measurable change can then be converted appropriately to a resultant force or torque.
Another advantage of the present sensor is that the housing 1 is completely closed, so that no dirt or the like can enter it.
A further advantage is that such a sensor R 1 can be used permanently at any desired point, for example on a transmission or some similar electromechanical or electromagnetic drive, in particular also in the field of handling technology and robotics.
The housing 1 offers mechanical and thermal protection against contamination, oil or the like, by means of the appropriate encapsulation.
In particular, it is also important that the core elements 8 . 1 , 8 . 2 are arranged in the sensor housing 1 such that they are prestressed in order that, for example, when a compression force is applied to the force transmitting element 13 , a stress change can be produced on the one hand in the one core element 8 . 2 and, in particular, in the corresponding coil 10 . 2 , in which case a change in the voltage on the coil 10 . 1 can be determined at the same time by subtracting the prestress in the other force element 8 . 1 .
Furthermore, it is intended to operate one of the two coils 10 . 1 or 10 . 2 as an exciter coil, and the other as a measurement coil. A voltage difference can be determined by superimposing the corresponding coil voltages. This provides a direct conclusion of the applied or varying force, or the corresponding torque.
The exemplary embodiment of the present invention illustrated in FIG. 2 shows a sensor R 2 which has a core element 8 . 3 which is surrounded by a coil 10 . 3 with a coil former 11 . In this case, the end faces of the core element 8 . 3 are supported on the covering element 3 .
The core element 8 . 3 may be held radially on the covering element 3 , or may be inserted into a corresponding recess.
Electrical cables, which are not particularly annotated here, connect the coil 10 . 3 to a voltage source U 1 .
In this case, the core element 8 . 3 and the coil 10 . 3 are arranged in a cylinder 2 , which can be connected to the covering element 3 in the manner described above.
It has been found to be advantageous for the cylinder 2 to be particularly thin and to be composed of a very soft, and possibly elastic, material, so that compression forces F acting from the outside on the covering element can be transmitted to the core element 8 . 3 without influencing the material of the cylinder 2 . The cylinders 2 may thus be very small, so that a housing 1 is formed which just surrounds the core element 8 . 3 with the covering elements 3 like encapsulation.
In this case, it is intended that the electrical connections be passed through the housing 1 , either through the cylinder 2 or through the covering element 3 , and that a corresponding contact point be sealed.
Such an encapsulated sensor R 2 has the major advantage that it can be used anywhere, at any desired points for example in a drive, without having to provide a separate housing, seal, compartmentalization or the like.
Furthermore, it is also intended for the core element 8 . 3 of the sensor R 2 to be inserted between the covering elements 3 such that it is prestressed. Corresponding tension forces can then also act on the sensor R 2 , and can be measured and determined in a corresponding manner via the voltage change. This is likewise within the scope of the present invention.
In the exemplary embodiment of the present invention, as shown in FIG. 3 , two sensor elements R 2 are connected to any desired external force transmitting element 13 on which, for example, a force F acts. Prestressing forces F 1 and F 2 may be applied at the end face at the other end.
The two voltages U 1 and U 2 on the two sensors R 2 change when a force F acts on the force transmitting element 13 . This voltage change likewise allows a torque and/or a force and/or a force and torque change to be determined. This arrangement is likewise intended to be covered by the present idea of the invention.
The exemplary embodiment of the present invention illustrated in FIG. 4 shows a sensor R 3 , whose design corresponds essentially to that of the sensor shown in FIG. 2 . However, in this case, two coils 10 . 1 , 10 . 2 are fitted onto the core element 8 . 3 , and their voltages U 1 , U 2 can be measured when an appropriate force and/or torque acts on them. In this case, one of the two voltages may be an exciter voltage, and the other may be the measurement voltage. | The invention relates to a sensor, in particular, a magnetostrictive or magnetoelastic sensor, comprising at least one core element which consists of a ferromagnetic material. Said core element is at least partially surrounded by at least one coil. The core element or elements are placed into a housing which is subjected to tensile and/or pressure forces, in order to determine the moment of force and/or the torque. | 6 |
TECHNICAL FIELD
The present invention relates generally to deep-fat fryers and, more particularly, to a, deep-fat fryer cooking oil filtration arrangement that includes a boil-out bypass feature.
BACKGROUND
A typical deep-fat fryer will include a fryer vat containing a heated bath of cooking oil. The cooking oil is adapted to receive baskets of food products such that the food products will be immersed within and cooked by the heated cooking oil. Such fryers include a heat exchanger, which may take the form of in vat fire tubes and associated burners, with combusted gases being passed therethrough to heat the oil.
To extend the useful life of the cooking oil, it is a common practice to filter the particulate food matter from the cooking oil to minimize the carbonization of such food matter within the cooking oil. Various configurations of filtering systems in which oil is drained from the vat into a pan, tub or other below unit containment vessel and then passed through a filter have been provided, with a pump used to return oil to the fryer vat after the oil has been filtered.
The cleaning process for fryer vats typically involves a “boil-out” process in which the vat is filled with a mixture of oil and vinegar and the heating system of the fryer is run to produce a boiling of the mixture, which in turn cleans the vat. Once the boil-out process is completed, the mixture must be removed from the vat, preferably drained without leaving any significant amount of the mixture in the unit and without running the mixture through the pump, as that may degrade the pump/motor assembly causing early failure. Typically, oil in the vat is drained into the pan, tub or other below unit containment vessel of the oil filtering system prior to the boil-out. Upon completion of the boil-out, including removal of the cleaning mixture, the oil in the vessel is returned to the vat. Since the oil is held in the below unit vessel during boil-out, the below unit vessel is not available for draining of the cleaning mixture. It would be desirable to provide a fryer that facilitates removal or draining of the boil-out cleaning mixture.
SUMMARY
A fryer unit includes a boil-out drain path that does not require boil-out fluid to pass through a pump.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 depict a prior art fryer including a filtration arrangement;
FIG. 2 is a side elevation of the oil pan and associated filter assembly of the fryer of FIG. 1 ;
FIG. 3 depicts one embodiment of a boil-out drain pipe;
FIG. 4 depicts an alternative embodiment of the end of a boil-out drain pipe;
FIG. 5 is a partial side view depicting position of the installed boil-out drain pipe;
FIGS. 6 and 7 show an alternative embodiment of a boil-out drain pipe;
FIG. 8 shows a schematic of an alternative embodiment using a three way valve;
FIG. 9 shows a schematic of en embodiment having a stowable drain pipe.
DETAILED DESCRIPTION
Referring to drawing FIGS. 1 and 2 , a fryer filtration arrangement similar to that shown and described in U.S. Pat. No. 6,890,428 is shown, with certain modifications made for implementing the boil-out bypass feature. The fryer 10 includes two fryer vats 12 A and 12 B. Each fryer vat includes at least one respective basket 16 A and 16 B which is automatically movable upward and downward via respective positioning guides 18 A and 18 B in a manner well known in the art. Manual raising and lowering of the baskets is also possible in some fryers. The fryer 10 includes a frame 20 which preferably includes associated housing 22 such as stainless steel. A front panel 24 of the fryer 10 includes a control and display panel 26 A and 26 B for each fryer vat. The lower portion of the housing frame includes a set of doors 30 A, 30 B which are movable between open and closed positions, and which are illustrated in the open position. Below the doors 30 A, 30 B a drawer 32 which is movable between open and closed positions relative to the frame 20 is provided, the drawer being illustrated in the open position. Positioned within the drawer 32 is an oil receiving pan 34 having a rim 36 which sits on rails 38 of the drawer 32 . Handles 40 extend from the interior sidewalls of the pan 34 to allow the pan to be easily picked up and removed from the drawer to facilitate cleaning at a location away from the fryer 10 . Positioning of the handles 40 on the inner portion of the pan helps facilitate simple positioning of the pan in the drawer 32 . As used herein, the term “pan” is intended to broadly encompass any oil receiving container, unless otherwise specifically indicated.
A basket type screen 42 is removably positioned within the pan 34 for filtering out debris entering the pan 34 within oil which is drained from one of the fryer vats 12 A and 12 B. At the bottom of the pan 34 a filter assembly 45 is provided for filtering the oil. An oil return path from the pan 34 back to the fryer vat 12 A, 12 B is formed in part by a coupler 44 which is connected to and extends from a front sidewall of the pan 34 . The illustrated coupler 44 extends rearwardly back toward the fryer frame 20 . A corresponding coupler 46 ( FIG. 2 ) is positioned on the fryer frame 20 , with the two couplers aligned for slidingly mating with each other in a friction fit arrangement when the drawer 32 is moved to a closed position.
In the illustrated fryer 10 , each vat 12 A, 12 B includes an associated exhaust stack 200 A, 200 B formed at the back of the fryer for venting combustion gases produced by the oil heating system which includes in vat fire tubes.
Referring now to FIG. 2 , the pan 34 includes an outlet opening 48 through its bottom wall 50 . The oil return path is formed in part by a flow passage through member 52 and piping 54 which runs along the external surface of bottom wall 50 and front wall 56 of the pan 34 .
Near the top of front wall 56 a wall penetrating coupling assembly 58 passes through the wall 56 , with piping 60 extending upward from the pan 34 and rearwardly as shown. The end of piping 60 acts as the return coupler 44 . The return coupler 44 mates with corresponding coupler 46 .
The oil return path leads back to the fryer vat and includes a pump 110 , which may be driven by an electric motor, positioned therealong for drawing oil out of the pan 34 and pumping it back to the vat. Oil traveling out of the pan 34 during a filtration operation travels from the pan 34 , through the outer filter screen material of the filter assembly 45 , into the interior of the filter assembly 45 , and out of the interior of the filter assembly 45 . Operation of the pump 110 , and the associated flow of oil drawn out of the pan 34 , creates a suction force for holding the coupler of the filter assembly 45 to the coupler of the pan 34 , without requiring any latch or hold down member. The suction force created by the pump 110 , and the associated flow of oil drawn out of the pan 34 , also holds the return coupler 44 of the pan 34 to the corresponding coupler 46 of the fryer frame 20 so as to maintain the drawer 32 in a closed position during a filtration operation, without requiring any positive latch.
In FIG. 2 , the fryer vat 12 B is shown. An outlet opening 120 B in a wall of the 12 B leads to a draining pipe 122 B. The draining pipe 122 B leads to a drain pipe/manifold 124 which extends laterally across a front portion of the fryer 10 as seen in FIG. 1 . The drain pipe 124 includes an outlet 126 for delivering oil into the pan 34 . Fryer vat 12 A includes a similar drainage path to the manifold 124 . Thus, each vat 12 A, 12 B includes a respective oil drain path extending from its outlet opening to the pan 34 . Positioned along each oil drain path is a flow control device 130 A, 130 B for controlling the draining of each vat. In particular, each flow control device may be a manually operable valve including a respective handle 132 A, 132 B for permitting a user to open and close the drain path as desired. Of course, other flow control devices may be used, including automatically controlled devices.
In connection with the boil-out cleaning process, one vat at a time is typically cleaned. For example, with respect to vat 12 B, drain valve 130 B would be opened to allow the oil from vat 12 B to drain into the pan 34 . The oil may be circulated through the vat 12 B, pan 34 and filter 45 for a period of time to filter out debris. The drain valve 130 B is then closed. The vat 12 B can then be filled with the cleaning fluid, which as described above may be a combination of oil and vinegar. The heating system for vat 12 B is then operated to bring the cleaning fluid to a boil for a cleaning time period, after which the cleaning fluid can be removed from the vat 12 B. In this regard, the manifold 124 includes boil-out drain opening 300 B that is typically covered by a cap member 302 B, which may have an associated tether 304 B to avoid loss of the cap member when removed. The opening 300 B is located in line with the drain path pipe 122 B and the drain valve 130 B. In the illustrated 2-vat fryer, a similar boil-out drain opening and cap member 302 A is provided in line with drain valve 130 A (see FIG. 1 ). The boil-out drain openings are adapted to receive a drain pipe as will be described in detail below.
Referring now to FIG. 3 , in one embodiment, the boil-out opening 300 B is internally threaded to threadingly receive the drain pipe 310 . The cap member may likewise include external threads for closing the opening. The illustrated boil-out drain pipe has an unthreaded drain end 312 , an externally threaded middle coupling portion 314 and an unthreaded, smaller diameter extension 316 which passes through diametrically opposite opening 320 . Opening 320 includes an associated mount flange 322 to which the drain valve 130 B (not shown) can be coupled. The end of extension 316 may be sized and configured for seating against an internal portion of the drain valve so that, with drain pipe 312 in place, when the drain valve is opened, the boil-out cleaning fluid bypasses the manifold 124 and instead passes directly along the drain pipe path 324 and out of the drain pipe 310 , thereby avoiding mixing of the boil-out cleaning mixture with the oil in the pan. Once the boil-out cleaning mixture is drained, the valve is closed and the drain pipe is unthreaded from opening 300 B. The cap member is then replaced, returning the fryer unit to its normal operating configuration. Referring to FIG. 4 , in an alternative embodiment; the end of the extension 316 could be tapered as shown, for seating against the inside surface of the flange 322 . Referring to the partial side view of FIG. 5 , note that the boil-out drain pipe 310 can be installed with the drawer unit in its closed position, and extends forward of the drawer unit, enabling a boil-out container 330 , such as a bucket or pan, to be placed in the front of the unit to receive the draining boil-out cleaning fluid. This feature is advantageous because, in many cases, the pan 34 will contain the vat oil and it would be undesirable to have to pull the pan out in such instances.
Referring now to FIGS. 6-7 , another embodiment is shown in which boil-out opening 300 B includes a flange 331 that is externally threaded (in which case the cap member is internally threaded for attachment). The boil-out drain pipe 310 ′ passes through opening 300 B without connection thereto. The opening 320 is includes an internally located threaded coupling 332 for receiving the end 334 of the drain pipe 310 ′ which is correspondingly threaded. Similar to FIG. 5 , the drain pipe 310 ′ may extend out past the drawer when installed, facilitating positioning of a boil-out cleaning fluid receiving vessel.
Thus, for a typical boil out of a given vat, oil is drained from the vat into the pan by opening the drain valve. The drain valve is closed. The vat is filled with the boil-out cleaning fluid. The heating system of the vat is operated for a cleaning time period. The cap member associated with the boil-out opening for the vat is removed. The boil-out drain pipe is installed. The boil-out cleaning fluid vessel is positioned in front of the fryer below the outlet of the boil-out drain pipe. The drain valve associated with the vat is opened, allowing the boil-out cleaning fluid to exit the unit via the boil-out drain pipe, bypassing the manifold. The valve is closed. The boil-out drain pipe is removed. The cap member of the boil-out opening is put back in place and the drain valve is closed. The oil in the pan is pumped back into the vat. In this way, the pump need not be used for moving the boil-out cleaning fluid, and the under unit oil-receiving pan or other vessel can be kept in place during the entire boil-out process.
In an alternative embodiment, as shown in FIG. 8 , the valve 132 B could be replaced by a three way valve. In one position, the valve is closed, preventing the contents of the vat from draining. In a second position the valve is opened to allow oil to be drained into the manifold 124 and ultimately into the oil-receiving drain pan 34 . In a third position the valve is opened to a allow the boil-out cleaning liquid to be diverted by a separate drain line/boil-out drain pipe, which need not be associated at all with the manifold, to a receptacle 330 for disposal. In one embodiment of this implementation the separate boil-out drain pipe may be a component that is not regularly removed from the fryer. Instead, and as shown in FIG. 9 , the boil-out drain pipe 310 ″ could be movable, as by rotation per arrow 350 , between a stowed position within the fryer (shown in dashed line form) and a use position in which the boil-out drain pipe extends forward of the front of the fryer (shown in solid line form).
Various boil-out drain pipe constructions have been shown and described. Regardless of the exact construction, the pipe may be formed as a single piece or as multiple different pieces coupled together as by press fitting or welding. The boil-out drain pipe could also be formed, in part or in whole, of a flexible or hose-like material. It is also recognized that the boil-out bypass path could be used for draining oil from the vat into a front located receptacle such as receptacle 330 of FIG. 5 .
Variations on the foregoing are possible. For example, while a fryer including two vats has been shown above in the illustrated embodiment, fryers including more or less vats could incorporate the subject boil-out drain feature. While the various constructions have been described primarily in conjunction with vat 12 B, it is recognized that in a multi-vat fryer apparatus each fryer vat could readily include a similar boil-out bypass feature. | A fryer unit includes a boil-out drain path that does not require boil-out fluid to pass through a pump. | 0 |
BACKGROUND OF THE INVENTION
In an all-wheel drive motor vehicle with a second drive axle (usually the rear axle) driven via a slip-controlled coupling, the problem exists that the rear wheels tend to over-brake and thus lose ground adhesion, leading to skidding of the vehicle. This happens because of the connection to the front wheels. The condition is especially apparent when the vehicle employs an ABS system, and in cases of lock-up braking.
For this reason the additional utilization of a dual action freewheeling coupling (sometimes referred to as an overrunning clutch) is customary so that a controllable separation coupling does not have to be used, and yet all-wheel drive in reverse travel is possible. For this reason dual-action clamping element couplings have been proposed, in which differential rotational speed sensing elements ensure coupling in both directions of torque flow and where centrifugal elements prevent a torque flow reversal at high speed (e.g., the German patent applications DE 42 01 375, 42 02 152 and 42 25 202 by the assignee herein). These solutions have the disadvantage, however, that when the circumferential speeds of the front and rear wheels differ because of tire wear or due to layout necessities, stress within the vehicle occurs at low speed and low load causing not only performance losses but also causing the clamping elements to be held in the clamped position. For this reason other solutions to this problem have been investigated.
The instant invention therefore relates to a rotationally dependent free-wheeling coupling comprising the following elements: a first ring which is the driving element in towing mode; a second ring which is the driven element in towing mode; clamping elements which act between the first and the second rings in both torque flow directions; a cage which holds the clamping elements; and a friction element actively connecting the cage to a fixed ring. (In this description, the "towing mode" refers to the situation wherein the engine drives the vehicle and torque flows from the engine to the axle, whether the vehicle is in forward or reverse travel. "Thrust mode" is the situation wherein the engine brakes the vehicle and torque flows from the axle to the engine.)
Such a free-wheeling coupling with clamping or wedging rollers acting in both directions for the transmission of drive forces to a second drive axle of a vehicle (here the front axle) is known from DE-A 27 40 638 (U.S. Pat. No. 4,124,085). A frictional connection exists between the ring pertaining to the second drive axle and a clamping roller cage. When overrunning occurs, a latch mechanism controlled via a second frictional connection to the fixed housing prevents the clamping roller cage from moving into the position in which torque flows from the second drive axle to the drive mechanism of the vehicle or to the first drive axle.
If reliable switching is desired in the free-wheeling coupling described therein, it is necessary to use a frictional element which has the disadvantages of relatively high power loss and a tendency to wear. Even so, reliable switching at extreme accelerations, e.g., with lock-up braking, is not ensured. Under extreme conditions of torque change, "breakthrough," a situation wherein the clamping elements disengage from the ramps associated with one torque flow direction and overshoot to the ramps for the opposite torque flow direction so that they couple when they should not do so during braking, can occur.
Another dual action free-wheeling coupling of a similar type was proposed in the as yet unpublished German patent application DE-43 11 288 (corresponding to U.S. application Ser. No. 08/222,802, filed Apr. 5, 1994) of the presented assignee. In the device described therein, completely friction and wear-free operation and protection against breakthrough when the direction of torque flow changes is ensured in all continuous operation states due to the interaction of a latch with the cage under the influence of a retaining spring and a slipping spring. However, there are still situations even with this free-wheeling coupling when faultless operation is not ensured. These situations may generally occur when the clamping elements are in a certain configuration (described as position 3 below and illustrated, for example, in FIG. 5) during start-up in the towing mode. Even if such situations occur rarely, it is necessary to correct them in view of the safety standards applied today in the construction of motor vehicles.
Such a situation arises, for example, as follows: When the vehicle climbs a slope in reverse and torque is thereby being transmitted to the rear axle, the free-wheeling device assumes position 3. In the free-wheeling coupling described in that patent application, position 3 is not an accessible configuration for forward travel in the thrust mode. Thus, when the driver stops the vehicle, shifts to a forward speed and lets the vehicle roll without operating the accelerator, the free-wheeling device cannot shift into the proper configuration. It is therefore not certain that the free-wheeling coupling will have zero torque in case of subsequent braking.
It is therefore the object of the invention, while avoiding the disadvantages of the two designs described above, to provide a free-wheeling coupling sensitive to the direction of rotation which has at its disposal sufficient switching force, with minimal friction losses, in all continuous operation states to access the proper configurations so as to avoid such problems in exceptional situations, and which eliminates the possibility of breakthrough even in case of sudden changes of direction of torque flow.
SUMMARY OF THE INVENTION
According to the invention, a free-wheeling coupling sensitive to the direction of rotation comprises a first ring which constitutes a driving element in the towing mode of the motor vehicle, a second ring which constitutes a driven element in the towing mode, clamping elements which act between the first and second rings to transfer torque between the first and second rings in both directions of torque flow, and a cage in which the clamping elements are held. The inventive free-wheeling coupling further comprises friction segments slaved to rotation of the cage in the circumferential direction, the friction segments interacting with a fixed friction ring and lifting off from the fixed friction ring due to centrifugal force after a certain rotational speed has been reached. The inventive free-wheeling coupling further comprises a catch interacting between the first ring and the cage to inhibit over-rotation of the cage with respect to the first ring. The cage is thus controlled in a direction-of-rotation sensitive manner. The interaction of these elements overcomes the problems in the above-described exceptional situations. Since the friction segments lift off from the fixed ring after a certain rotational speed has been reached, the element which senses absolute rotational speeds does not cause any frictional losses in continuous operation states. The catch interacting between the cage and first ring prevents breakthrough even in case of a sudden change in the direction of torque flow.
The catch is preferably mounted on the first ring which is the inside ring in such manner as to be capable of swivelling around a longitudinal axis and is engageable with a recess of the cage. Thus an advantageous configuration and placement of the catch and a coupling with minimal overall dimensions is obtained.
In a first embodiment of the invention, the catch acting between the first ring and the cage is mounted eccentrically on tile first ring and is engageable with a recess of the cage as a result of the centrifugal force acting upon it. In a second embodiment of the invention, the catch acting between the first ring and the cage is essentially mounted centrically on the first ring, and a friction element interacts with the fixed friction ring, said friction element being connected to a point of application of force of the catch outside its swivelling axis, thus causing its engagement with the recess of the cage. In this latter embodiment, the immediate assumption of a free-wheel position is ensured even when lock-up braking occurs at high speed. It will be apparent that both of these embodiments can also be implemented by mounting the catch on the cage, with the catch being engageable with a recess of the first ring.
In a variant of both embodiments, a stop is provided on the cage to restrict the radial outward movement of the friction segments and an additional friction element is located between the second ring and the cage.
In another variant of both embodiments, a stop is provided on the second ring to restrict the radial outward movement of the: friction segments, the stop exerting a frictional torque to the second ring when the friction segments are applied, causing a relative rotation to take place between the second ring and the cage.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described and explained in greater detail below with reference to the drawings, wherein
FIGS. 1 and 1a show axial sections of first and second variants respectively of a first embodiment of the inventive free-wheeling coupling;
FIGS. 2 and 2a are cross-sections along II--II and II'--II' of FIGS. 1 and 1A respectively for both variants of the first embodiment;
FIGS. 3,4,5 schematically show operation of the invention for three different initial positions at start for forward travel in towing mode for the first embodiment;
FIGS. 6,7,8 schematically show operation of the invention for three different initial positions at start for forward travel in thrust mode for the first embodiment;
FIGS. 9,10,11 schematically show operation for three different initial positions at start for reverse travel in towing mode for the first embodiment;
FIGS. 12,13,14 schematically show operation for three different initial positions at start for reverse travel in thrusting mode for the first embodiment;
FIGS. 15,16,17 schematically show operation when braking under different conditions in forward travel in the first variant of the first embodiment;
FIGS. 18,19,20 schematically show operation when braking under three different conditions in forward travel in the second variant of the first embodiment;
FIG. 21 schematically shows operation when braking in reverse travel in the first variant of the first embodiment;
FIG. 22 schematically shows operation when braking in reverse travel in the second variant of the first embodiment;
FIG. 23 is an axial section through a second embodiment of the free-wheeling coupling according to the invention;
FIG. 24 is a cross-section taken along XXIV--XXIV of FIG. 23;
FIG. 25 schematically shows operation of the second embodiment at low speed and with forward acceleration;
FIG. 26 schematically shows operation of the second embodiment at low speed when braking in forward travel;
FIG. 27 schematically shows operation of the second embodiment at high speed with forward acceleration;
FIG. 28 schematically shows operation of the second embodiment at high speed when braking in forward travel;
FIG. 29 schematically shows operation of the second embodiment during reverse acceleration in towing mode; and
FIG. 30 schematically shows operation of the second embodiment when braking in reverse travel.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1 and 1a show the stationary housing 1 of a free-wheeling coupling installed in the drive train of an all-wheel drive motor vehicle. The free-wheeling coupling is connected for drive via a drive shaft 2 to a permanently driven axle (e.g., a front axle which is connected to the not-shown engine and transmission block). The drive shaft 2 is supported in housing 1 by a bearing 3 and ends in a splined shaft extension 4 on which a first ring 5 (the inner ring of the free-wheeling coupling) is seated. This first ring 5 is surrounded by a number of clamping elements 6. In FIGS. 1 and 1a, these are wedging rollers, but they may also be symmetric sprags which act in both directions of torque flow. The inner ring 5 is polyhedral with contact surfaces (ramps) for the clamping rollers. The clamping elements 6 are surrounded by an outer ring 7 which has a cylindrical running surface for the clamping elements 6. The outer ring 7 is centered in relation to the drive shaft 2 by means of a bearing 8 and is connected to the drive shaft 9 which leads to a rear axle not shown here.
A cage 11 which has an extension 12 of increased diameter is provided for guidance of the clamping elements 6. A number of friction segments 13 are installed and guided in openings of this extension 12. The friction segments 13 are pressed by a tubular spring 14 against a first fixed friction ring or collar 15 which may be part of the housing 1 but is in any case stationary. The friction segments 13 are slaved with the rotation of the cage 11 in the circumferential direction and, after a certain rotational speed has been reached, are lifted outwardly away from the friction ring 15 by the centrifugal force acting upon them in opposition to the pressing force of the tubular spring 14.
Two possibilities exist to limit the outward movement of the friction segments 13: According to FIG. 1a, the cage extension 12 includes an annular stop 20 which is frictionally connected to the outer ring 7 via a friction element 21. The stop 20 may be a disk connected radially to the cage extension 12 and which is radially crimped outside the friction segments 13. The friction element 21 may be made in the form of a friction ring or a number of slip springs or friction plates.
In FIG. 1, a stop 24 constitutes a ring-shaped extension of outer ring 7 with a diameter that is such that it surrounds the friction segments 13 on the outside, again with radial clearance. A friction element between the outer ring 7 and cage 11 is not required in this case, but a safety ring 25 is provided which prevents axial displacement of the cage 11.
Both variants are provided with catches 32 pivotably mounted on catch axes 30 on the inner ring 5, with noses 33 insertable into recesses 35 of the cage 11. These recesses are provided on the inside of the cage extension 12 and extend over an arc which corresponds approximately to the angle of rotation between cage 11 and inner ring 5 between a coupled and a neutral central position of the clamping elements 6. The catches 32 are held by torsion springs 36 in a retracted position in which the noses 33 are located outside the recesses 35. The noses 33 only take effect in recesses 35 when they are swivelled outward by centrifugal force which counteracts the force of the torsion springs 36 for sufficiently rapid rotation. Once the noses 33 enter the recesses 35, they prevent rotation of cage 11 relative to inner ring 5 beyond the central neutral position.
To adjust the limit speeds, one to lift the friction segments 13 away from fixed friction ring 15 in opposition to the force of tubular spring 14, and the other for the insertion of noses 33 of the catches 32 into recesses 35 of cage 11 in opposition to the force of torsion springs 36, the masses of the various elements, their centers of gravity, and the forces of springs 14 and 36 must be selected appropriately. This appears clearly from the following description of the operation of the invention.
For the description of operation in various different states, the convention adopted is that the thick arrows represent force and torque, and the thin arrows represent (rotational) direction of movement, the size of said arrows generally corresponding to the magnitude of what they represent.
1. Starting forward in towing mode operation (FIGS. 3 to 5)
Depending on previous history, the free-wheel may be in three different initial positions at the time of start-up which are shown in FIGS. 3-5. When starting up, regardless of initial position, the first ring 5 provides drive, as illustrated by the longer inner arrow labelled FORWARD. In position 1 shown in FIG. 3, the clamping elements 6 are already wedged between the rings 5, 7. Therefore no action or frictional engagement of the cage is required.
When the vehicle starts up on a firm road surface from position 2 (neutral) shown in FIG. 4, both rings 5,7 would immediately begin to rotate at high speed with a free-wheeling coupling according to the prior art. Frictional engagement between the cage 11 and one of the two rings would therefore not engage the clamping elements 6 at that time. The frictional connection between cage 11 and the fixed friction ring 15 produces a tractive moment M sv which leads to contact with the clamping elements 6. The same applies to start-up from position 3 shown in FIG. 5.
2. Starting forward in thrust mode (FIGS. 6 to 8)
If the vehicle rolls on a slope without the accelerator being operated (engine brakes), the outer ring 7 (large outer arrow labelled FORWARD) drives. Also, the two rings 5,7 will rotate at the same speed on a firm road surface. If the free-wheeling coupling is in position 1 (FIG. 6), the clamping elements 6 can go into coupling position (which they should not do) when the cage 11 is not held by friction by the friction ring 15 (tractive moment M sv ). The same applies to position 2 (FIG. 7).
In position 3 (FIG. 8), the clamping rollers are already in clamping position, but are not yet clamped. In this position the danger of unwanted coupling is especially great, and therefore a considerable tractive moment M sv and thereby also a great frictional force F fr are needed in order to hold the cage 11 while the two rings 5,7 are torn away (from position 3 via position 2 into position 1) without clamping to take place.
3. Starting in reverse in towing mode (FIGS. 9 to 11):
When starting from position 1 (FIG. 9), frictional contact between cage 11 and outer ring 7 (present in the first variant of the first embodiment) suffices to hold the clamping elements 6 in engagement position (position 3), and the friction in relation to the fixed friction ring 15 (in the second variant of the first embodiment) has the same effect. This also applies to position 2 (FIG. 10), except that the path is shorter.
4. Starting in reverse in thrust mode (FIGS. 12 to 14)
When rolling backwards from position 1 (FIG. 12), the clamping elements 6 are in coupling position without however being coupled. The tractive moment M sr causes them to be brought via position 2 (FIG. 13) into position 3 (FIG. 14) in which they cannot couple.
5. Braking during forward travel, first variant of the first embodiment (FIGS. 15 to 17)
During forward travel in towing mode, the clamping elements 6 are always in position 1. If the brakes are now applied, what follows depends on the travel speed at the beginning of brake application. If, as shown in FIG. 15, it is less than vs (that is the speed beyond which the rear axle drive should be uncoupled during braking), the outer ring 7 starts to pass the inner ring 5 (larger outer arrow labelled FORWARD), the cage 11 is slaved by the frictional moment M' sv (because this is the first variant of the first embodiment) between outer ring 7 and cage 11 and by its own moment of inertia M cagemass . Since these two moments together are greater than the frictional moment M sv , the clamping elements are placed in position 3 in which they transmit the braking forces to the rear axle. However M sv must always be greater than M' sv so that free running is ensured when starting up in thrust mode from position 3.
If the vehicle speed is greater than vs (FIG. 16), the centrifugal force F mk acting on the catch 32 overcomes the moment M fk of the torsion spring 36 and the nose 33 of catch 32 comes to lie in the recess 35 of the cage 11 so that its rotation is stopped in neutral position is ended. The clamping elements 6 cannot go into coupling position and the rear axle therefore runs freely. The catch 32 prevents the clamping elements 6 from breaking through into coupling position even when braking is very abrupt.
If the travel speed is greater than v1 (FIG. 17) the friction segments 13 are lifted off the fixed friction ring 15. Although the tractive moment M sv is removed from the friction ring 15 as a result, the action of the catch 32 is such as described in the preceding paragraph.
6. Braking during forward travel, second variant of the first embodiment (FIGS. 18 to 20)
The second variant of the first embodiment is different from the above only if the travel speed v is greater than v1 (FIG. 20). In that case, the lifted friction segments 13 press outwardly against stop 24 of the outer ring 7. As a result, the frictional moment M' s of stop 24 which is very high because of the centrifugal force F mr acting upon the friction segments 13, acts upon the cage 11, and the moment of inertia M cagemass of the cage and the centrifugal force are absorbed by the catch 32 as soon as the clamping elements are in neutral position.
7. Braking in reverse, both variants of the first embodiment (FIGS. 21 and 22)
During braking in reverse travel, the clamping elements 6 are always in position 3. The free-wheeling coupling is therefore assumed to be in this position at the beginning of braking. Whether uncoupling then takes place depends on the relationship of the frictional moments and the moment of mass of the cage. The frictional moments vary depending on the variant of the first embodiment. In the first variant (FIG. 21), M sr and M' sr are opposed to each other. As long as M' sr +M cagemass <M sr , free running is ensured. If the mass of the cage is increased, coupling takes place. In the second variant (FIG. 22), there is no M' sr at low speed. Depending on whether the mass of the cage or the frictional moment of the friction segments is greater, coupling or uncoupling takes place. The catch 32 does not enter into play for as long as travel is not rapid. With normal vehicles however, one does not travel rapidly in reverse.
In FIGS. 23 and 24 which represent a second embodiment of the invention, identical parts are given the same reference numbers as in the first embodiment. Only those parts by which this second embodiment differs from the first are described and are given different reference numbers. The catch 32 is able to swivel around axis 30 approximately in its center of gravity and is provided with a foot 45 with an oblong opening 44. A slaving pin 43 of a friction body 40 capable of rotating on shaft 4 and which rubs with a friction lining 41 on a second fixed friction ring or collar 42 engages this opening. The friction lining 41 lifts off at high rotational speed in a similar manner to friction segments 13 and the second fixed friction ring 42 may also be identical with the first fixed friction ring 15. The spring 36 is placed so that in forward travel its force is applied in the same direction as the force exerted by friction body 40 on catch 32 and in reverse travel is opposite to this force. As a result, the catch 32 is always in active position during forward travel, even at high speed, and is retracted for reverse travel.
With the exception of these differences, the operation is the same as for the first embodiment.
FIG. 25: During forward acceleration at low speed (i.e., at a speed at which the friction segments 13 are still pressing against the friction collar 15), the inner ring 5 rotates faster than the outer ring 7. The cage 11 is retained by the friction segments 13.
FIG. 26: If the brake is applied while traveling forward at low speed, the inner ring 5 is decelerated more than the outer ring 7. With normal deceleration, the force of the friction segments 13 is sufficient to keep the cage 11 in free-running position. With rapid deceleration (blocking of the front axle), the moment of inertia of the cage 11 could exceed the tractive moment of the friction segments 13 and move the cage 11 together with the clamping elements 6 towards the thrusting position. This is prevented by the catch 32 locking the cage 11 in free-running position.
FIG. 27: During forward travel at high speed, both friction elements 13 and 41 are lifted from their counter-surfaces by centrifugal force and no friction losses occur there, by contrast to the states according to FIGS. 25 and 26, if the cage 11 includes the radial stop 20 for the friction segments 13.
FIG. 28: The catch causes uncoupling.
FIGS. 29 and 30: Since the catches are retracted by the effect of the friction lining 41 during reverse travel, both directions of torque flow are possible.
While the invention has been described by reference to specific embodiments, this was for purposes of illustration only. Numerous alternative embodiments will be apparent to those skilled in the art and are considered to be within the scope of the invention. | A free-wheeling coupling sensitive to the direction of rotation for a motor vehicle comprises a first ring which constitutes a driving element in a towing mode of the motor vehicle, a second ring which constitutes a driven element in the towing mode, clamping elements which act between the first and second rings to transfer torque in both directions of torque flow, a cage in which the clamping elements are disposed, a fixed friction ring, and a friction element actively connecting the cage to the fixed friction ring. The friction element comprises a plurality of friction segments disposed between the cage and the fixed friction ring, the friction segments being slaved to rotate in the circumferential direction with the cage and being lifted away from the fixed friction ring by centrifugal force when they are caused to rotate at a rotational speed which is greater than a predetermined rotational speed. The free-wheeling coupling further comprises a catch interacting between the first ring and the cage under the control of frictional force or an additional frictional element to inhibit over-rotation of the cage with respect to the first ring, thereby preventing "breakthrough" of the clamping elements when the direction of torque flow changes abruptly. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor fabricating method. More particularly, the present invention relates to a method of forming a gate.
2. Description of the Related Art
Because a conventional gate is made of polysilicon with a large grain size, the surface of the gate is rough. The rough surface of the gate causes scattering of a deep ultra violet ray. The scattering of a deep ultra violet ray causes difficulty in controlling a critical dimension (CD) of the gate. Therefore, the uniform critical dimension of gate is rarely achieved.
Another problem that occurs in the conventional gate is a channeling effect. That is, boron ions in the gate easily gather at a boundary between the gate and the gate oxide layer. Once the amount of gathered boron reaches a specific number, boron ions easily penetrate into the gate oxide layer. The device failure is occurred when the boron ions penetrate into the gate oxide layer.
SUMMARY OF THE INVENTION
The invention provides a method of fabricating a gate. A gate oxide layer on a substrate. A first amorphous silicon layer, a polysilicon layer, and a second amorphous silicon layer are formed in sequence over the substrate to form a sandwich structure. The sandwich structure comprises the first amorphous silicon layer, the polysilicon layer, and the second amorphous silicon layer. The sandwich structure is patterned to form a gate.
The invention forms a sandwich structure comprising a first amorphous silicon layer, a polysilicon layer, and a second amorphous silicon layer. Because surface of the uppermost amorphous silicon layer of the sandwich structure is smooth, the critical dimension can be preferably controlled and the uniform critical dimension of a gate can be obtained. In addition, after a thermal step, the sandwich structure transform into a gate structure comprising a polysilicon layer with a small grain size, a polysilicon layer with a large grain size, and a polysilicon layer with a small grain size. Thus, in the invention, the gate provides small grains to increase the boundary between the polysilicon layer and the gate oxide layer. With an increased boundary, the boron penetration to gate oxide layer is effectively reduced.
In addition, the present invention also provides another method of fabricating a gate. A gate oxide layer is formed on a substrate. A first doped polysilicon layer is formed on the gate oxide layer. A second doped polysilicon layer on the first doped polysilicon layer. A third doped polysilicon layer over the second polysilicon layer. The second doped polysilicon layer has a grain size larger than a grain size of both the first doped polysilicon layer and the third dope polysilicon layer. The above-described advantages are also included in the gate formed by this method.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,
FIGS. 1A through 1C are schematic, cross-sectional views showing a fabrication method of a gate according to one preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
FIGS. 1A through 1C are schematic, cross-sectional views showing a fabrication method of a gate according to one preferred embodiment of the invention.
In FIG. 1, a substrate 100 is provided. The substrate 100 preferably is a semiconductor substrate, such as a silicon substrate. A gate oxide layer 102 is formed on the substrate 100. A first thin amorphous silicon layer 104 is formed on the gate oxide layer 102. Or, in stead of forming the first thin amorphous silicon layer 104, a first polysilicon layer with a small grain size 104 is formed on the gate oxide layer 102. The thickness and the forming step of the first polysilicon layer with small grain size 104 is the same as the first thin amorphous silicon layer 104 described below. The thickness of the first thin amorphous silicon layer 104 preferably is about 50 Å to 300 Å. The first thin amorphous silicon layer 104 can be formed by, for example, low-pressure chemical vapor deposition (LPCVD) at a temperature of about 500° C. to 600° C., plasma-enhanced chemical vapor deposition (PECVD) at a temperature of about 200° C. to 300° C., or other suitable deposition steps. A thick polysilicon layer 106 is formed on the first thin amorphous silicon layer 104, or on the first polysilicon layer with small grain size 104. The thickness of the thick polysilicon layer 106 preferably is about 500 Å to 3000 Å. The thick polysilicon layer 106 can be formed by, for example, low-pressure chemical vapor deposition (LPCVD) at a temperature of about 575° C. to 650° C., plasma-enhanced chemical vapor deposition (PECVD), or other suitable deposition steps. A second thin amorphous silicon layer 108 with a grain size is formed on the thick polysilicon layer 106. Or, in stead of forming the second thin amorphous silicon layer 108, a second polysilicon layer with a small grain size 108 is formed on the thick polysilicon layer 106. The thickness and the forming step of the second polysilicon layer with small grain size 108 is the same as the second thin amorphous silicon layer 108 described below. The step of forming the second thin amorphous silicon layer 108 is the same as the above-described step of forming the first thin amorphous silicon layer 104. That is, the second thin amorphous silicon layer 108 can be formed by, for example, low-pressure chemical vapor deposition (LPCVD) at a temperature of about 500° C. to 600° C., plasma-enhanced chemical vapor deposition (PECVD) at a temperature of about 200° C. to 300° C., or other suitable deposition steps. A sandwich structure 109 comprising the first amorphous silicon layer 104, the polysilicon layer 106, and the second amorphous silicon layer 108, or the first polysilicon layer with a small grain size 104, the polysilicon layer 106, and the second polysilicon layer with small grain size 108, is formed on the gate oxide layer 102.
Specifically, the sandwich structure 109 can be formed by a single performance of low-pressure chemical vapor deposition or single performance of plasma-enhanced chemical vapor deposition. In a single deposition step, the sandwich structure 109 can be formed by adjusting process parameters, such as temperature, of a deposition chamber to form each layer of the sandwich structure 109. Thus, it is not necessary to move the substrate 100 from chamber to chamber when depositing each layer of the sandwich structure 109. The sandwich structure 109 can be completed in a single chamber. Additionally, there also are various ways to form the sandwich structure 109. For example, each layer of the sandwich structure 109 can also be formed by different deposition steps, or each layer of the sandwich structure 109 can be formed by alternately performing deposition steps, such as alternately performing low-pressure chemical vapor deposition and plasma-enhanced chemical vapor deposition.
In FIG. 1B, the sandwich structure 109 is patterned to form a gate structure 109a. The gate structure 109a comprises a first amorphous silicon layer 104a, a polysilicon layer 106a, and a second amorphous silicon layer 108a, or a first polysilicon layer with a small grain size 104a, a polysilicon layer 106a, and a second polysilicon layer with a small grain size 108a. Because the amorphous silicon layer 108, or the second polysilicon layer with a small grain size 108, has a smooth surface, the scattering of the ultra violet ray can be avoided. The critical dimension can be effectively controlled. Therefore, uniformity of critical dimension can be obtained.
An ion implantation step is performed in order to increase the conductivity of the first amorphous silicon layer 104 (140a), the polysilicon layer 106 (106a), and the second amorphous silicon layer 108 (108a), or the first polysilicon layer with a small grain size 104 (104a), the polysilicon layer 106 (106a), and the second polysilicon layer with a small grain size 108 (108a). The ion implantation step can be performed before or after the step of patterning the sandwich structure 109. The implanted ions can be N-type ions or P-type ions. N-type ions are chosen from the group consisting of P + , As + , Sb + or the like. P-type ions are chosen from the group consisting of B + , BF 2 ,In + , or the like.
In FIG. 1C, a thermal step is performed after ion implantation. The thermal step makes ions spread homogeneously. The thermal step can be, for example, a rapid thermal annealing. After the thermal step, the amorphous silicon layers 104a and 108a are crystallized into polysilicon layers 104b and 108b, while the polysilicon layer 106a substantially preserves its original crystal phase. The conductivity of the polysilicon layers 104b and 108b thus is increased after the thermal step. The polysilicon layer 104b has a grain size smaller than the grain size of the polysilicon layer 106a. The polysilicon layer 108b has a grain size smaller than the grain size of the polysilicon layer 106a. A sandwich-structured gate 109b comprising the polysilicon layer 104b, the polysilicon layer 106a, and the polysilicon layer 108b is formed. The present invention solves the channeling effect by providing the polysilicon layer 104b with a small grain size. In comparison with the conventional method, in which the polysilicon layer is made of large grain size, the small crystal grains of the polysilicon layer 104b provide a larger boundary between the polysilicon layer 104b and the gate oxide layer 102. With an increased boundary, ions can be effectively dissipated, and thus their penetrating effect can be significantly reduced.
In summary, the invention has the following advantages:
1. The invention forms a sandwich structure comprising a first amorphous silicon layer, a polysilicon layer, and a second amorphous silicon layer, or a first polysilicon layer with a small grain size, a polysilicon layer, and a second polysilicon layer with a small grain size. Because surface of the uppermost layer of the sandwich structure is smooth, the critical dimension can be preferably controlled and the uniform critical dimension of a gate can be obtained.
2. The invention forms a sandwich structure comprising a first amorphous silicon layer, a polysilicon layer, and a second amorphous silicon layer, or a first polysilicon layer with a small grain size, a polysilicon layer, and a second polysilicon layer with a small grain size. If the sandwich structure comprises the first amorphous silicon layer, the polysilicon layer, and the second amorphous silicon layer, after a thermal step, the sandwich structure transform into a gate structure comprising a polysilicon layer with a small grain size, a polysilicon layer with a large grain size, and a polysilicon layer with a small grain size.
3. In the invention, the gate provides small grains to increase the boundary between the polysilicon layer and the gate oxide layer. With an increased boundary, the boron penetration to gate oxide layer is effectively reduced.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure and the method of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents. | A method for fabricating a gate. A gate oxide layer is formed on a substrate. A first doped polysilicon layer is formed on the gate oxide layer. A second doped polysilicon layer on the first doped polysilicon layer. A third doped polysilicon layer over the second polysilicon layer. The second doped polysilicon layer has a grain size larger than a grain size of both the first doped polysilicon layer and the third dope polysilicon layer. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This disclosure generally involves a method to prepare a nanosized-structure film and its application, especially the method to prepare a nanosized-structure film of multi-phobic effects and its application.
[0003] 2. Description of the Related Art
[0004] Currently, there are many varieties and preparation methods of nanosized film materials and the preparation methods include colloid suspension chemical deposit method, self-assembly method, surface improvement method and electrochemical deposit method and with these methods many types of nanosized-structure functional films are prepared, such as nanosized-semiconductor film, nanosized porous film, nanosized optic film, nanosized magnetic film and nanosized tribological film. With the available technology, nanosized structure film is generally prepared from particles and liner. From the above functions of nanosized-structure films, yet no nanosized-structure film of multi-phobic effects and its preparation methods are claimed. This type of film utilizes the phobic effects to make any substances contacting a substrate (liner) to be fast released or dispersed from the substrate and thus prevent them from adhering to the substrate.
[0005] There are many decomposing, hydrophobic and oleophobic materials (i.e., the concept of single-phobic and dual-phobic), and their products are hydrophobic and oleophobic and thus they are water-proof and oil-proof. In the available technology the action merely repels water or oil is called single-phobic and the action repels both water and oil called dual-phobic. We define these materials as phobic-effect materials.
[0006] Currently, the phobic-effect materials generally consist of many chemical materials, which combine with the substrate through chemical reaction or chemical bonds and thus change the chemical and physical properties of the substrate. The representative phobic-effect materials include Teflon, N-(t-butyl) acryamide, ethyl-tetradecyl acrylate, vinyl laurate, halogen-bearing monomer, and N-fluoro styrene. Another way to render the substrate water-proof and oil-proof is to add wrapping materials of hydrophobic or oleophobic group (functional group) to the substrate, which are generally super-fine powder or liquid. However, the available technology tend to have the following demerits:
[0007] I. The available nanosized-structure films have no multi-phobic effects and they are generally optic film, magnetic film, semiconductor film, conducting film and tribological film.
[0008] II. The “phobic-effects” materials in the available technology have merely a single function of water-proof, oil-proof, bacteria-proof, or electromagnetic-proof and they are generally not phobic to several substances.
[0009] III. The chemical compositions of the available technology mainly consist of organic substances or wrapping material. The materials have unstable performances and poor durability, and some of them even contain contaminating components and fail to meet ecological requirements.
[0010] IV. In the available technology of the single-phobic materials, some powdered materials are used. However, because of their relatively large particle size (generally above 1000 nm) they are not easy to disperse in liquid to form a colloid. When added to the medium, they merely generate unobvious effects and even impair product's luster. In addition, the functional groups on the powder are absorbed onto the powder surface through physical means, therefore, the bonds between the functional groups and the powder are not strong and will be weakened with lapse of time and increase in temperature, thus impairing the functions of the materials and products.
BRIEF SUMMARY OF THE INVENTION
[0011] In certain embodiments, a nanosized-structure film material of multi-phobic effects and its application are described. This material keeps the performances of both the substrate and product stable and has multi-functions of being hydrophobic, oleophobic, dust-proof, bacteria-proof and aging-proof.
[0012] More specifically, a new type of film and concept of function are proposed, i.e., nanosized structure “multi-phobic effects” film and its preparation. As used herein, the term “multi-phobic effects” means that functionally the nanosized film is able to catalyze, decompose, repel and disperse 3 or more substances, including water, oil, organic foreign matter, inorganic dust, bacteria, light, electricity and magnetism. On the other hand, the single-phobic or dual-phobic materials in the background technology belong to “element-phobic material”.
[0013] A new method to prepare nanosized-structure film and its application are also described herein, in which the primary nanosized particle and filming substance are combined with the substrate under given conditions to form stable nanosized-structure compounded film.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0014] In the drawings, the sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn, are not intended to convey any information regarding the actual shape of the particular elements, and have been solely selected for ease of recognition in the drawing.
[0015] FIG. 1 is a schematic diagram of an embodiment illustrating a substrate coated with a nanosized film of multi-phobic effects.
DETAILED DESCRIPTION OF THE INVENTION
[0016] As noted above, a method to prepare multi-phobic effects nanosized-structure film and its application are described herein. It features nanosized material comprising: nanosized bacteria-proof material, nanosized catalysts, nanosized interfacial material, nanosized surface energy-consuming materials and nanosized decomposing materials. The particle size of above materials is below 100 nm, and the above nanosized materials are modified with fluorocarbon surfactants and kept continuous with fluorocarbon filming substances. The thickness of the film is below 500 nm and the film structure may be divided into discontinuous phase and continuous phase.
[0017] In the embodiment illustrated in FIG. 1 , a plurality of three types of nanosized particles 10 , 20 and 30 , also referred herein as “nanoparticles”, are randomly distributed in a filming substance 2 to form a nanosized film 4 . The nanosized film 4 is coated or otherwise integrated on a substrate 1 through penetration, absorption and chemical bonds. More specifically, nanoparticles 10 , 20 and 30 represent at least three types of materials and collectively provide multi-phobic effects. Each type of the nanoparticles 10 , 20 and 30 is surfaced modified by at least one of a corresponding type of fluorocarbon surfactant, 12 , 22 and 32 , respectively.
[0018] In particular, a method to prepare multi-phobic effects nanosized-structure film and its application are described as follows:
[0000] I. Selection of raw materials:
[0019] (I) Selection of nanosized materials:
[0020] a. Nanosized bacteria-proof material: silica carrier-based (SiO 2−X ) metal ion bacteria-proof material, at proportion of 8%-12%. Brand: SS 1 , DS 1 and SP 1 .
[0021] b. Nanosized catalysts: nanosized titanium oxide (TiO 2 ). Brand: DJ 3 , DJ 3−S .
[0022] c. Nanosized decomposing material: zinc oxide (ZnO). Brand: MN6Z.
[0023] d. Nanosized interfacial material: Alumina (AlO 3 ). Brand: NR-3Al.
[0024] e. Nanosized surface energy-consuming material: (TiO 2 ). Brand: RX-05.
[0025] (II) Selection of modifying aids:
[0026] Nanosized material modifying aids may be selected from different types of fluorocarbon surfactants depending on type of the above-mentioned nanosized materials, including:
[0027] Nanosized bacteria-proof material: tetrafluoro-isophthalonitrile surfactant.
[0028] Nanosized catalysts: fluorocarbon silane surfactant.
[0029] Nanosized decomposing material: perfluoro fluoro-silicone polymeric surfactant.
[0030] Nanosized interfacial material and surface energy-consuming material: 5% fluoroalkyl surfactant.
[0031] (III) Selection of filming substance:
[0032] The filming substance may be selected from fluorocarbon filming active material. An example of a filming substance includes, but is not limited to: perfluoro alkyl sulfuryl alkyl acrylate.
[0033] (IV) Selection of dispersing media of nanosized material:
[0034] The dispersing medium for modifying nanosized material may be an aromatic hydrocarbon. Typically, aliphatics-substituted aromatics, or their derivatives, for example, toluene and xylene are used as dispersing medium.
[0035] In preparation of dispersing medium for nanosized-structure film, on the other hand, deionized water is used.
[0000] II. Preparation methods:
[0036] (I) Process for modifying nanosized material:
[0037] The nanosized material used can be modified as follows: Disperse the above-mentioned nanosized powdered materials in dispersing medium xylene, add fluorocarbon surfactants to the dispersing medium at proportion of nanosized material: fluorocarbon surfactants ranging from about 1:0.005-1:0.01 to make hydroxyl groups on surface of nanosized material completely react with fluorocarbon surfactants, remove dispersing medium, and obtain nanosized modified powdered materials through drying.
[0038] (II) Process of preparation of nanosized compounded material:
[0039] 1. Compounding proportion for nanosized compounded powder: Thoroughly mix the above-mentioned nanosized materials in an agitator at proportion of:
a: b: c: d: e=20-30%:15-25%:20-30%:15-25%:15-20%
[0040] (III) Preparation of nanosized filming paste:
[0041] 1. Selection of raw materials
[0042] f. Nanosized material: the above-mentioned nanosized modified compounded material, 0.1-2%.
[0043] g. Fluorocarbon filming substance: perfluoro alkyl sulfuryl alkyl acrylate 2-4%.
[0044] h. Functional aid: polyoxyethylennated alcohol, 0.05%-0.1%.
[0045] i. Dispersing medium: deionized water, 85-95%.
[0046] In one embodiment, the compounding proportion is:
f: g: h: i=2%:4%:0.1%:93.9%
[0047] 2. Process of preparation of filming paste:
[0048] Prepare raw materials at the above-mentioned proportion, add functional aid to dispersing medium (deionized water) at 50-70° C. and constant agitation to make the functional aid evenly dissolved in dispersing medium, slowly add the modified nanosized compounded material to the above solution under agitation at 120-160 rpm for 20-30 minutes, make indirect dispersion with emulsifying machine for 10-20 minutes to make nanosized material evenly dispersed in the liquid phase, slowly add fluorocarbon filming substance to the dispersed nanosized liquid phase and slowly and evenly mix the solution.
[0049] (IV) Process of preparation of nanosized-structure film:
[0050] Thoroughly clean the substrate to be filmed, apply the filming paste onto the substrate through spray or dipping, dry the pasted substrate at 120-180° C. for 0.5-1 minute and control the thickness of nanosized-structure film through adjusting paste concentration, production link or filming-pressure.
[0051] Advantageously, the nanosized film prepared with the above-mentioned technical scheme has different functions, filming process, used materials and microstructure, and offers the following merits:
[0052] I. The nanosized-structure film in this disclosure is in-situ combined with the substrate and is inseparable from the substrate.
[0053] II. The nanosized material used for the nanosized-structure film is a multi-functional compounded material and through surface modifying, the film is able to repel and disperse water, oil, organic foreign matter, inorganic dust, bacteria, light, electricity and magnetism and overcome the demerits of single-phobic or dual-phobic materials in the existing technology.
[0054] III. The modifying aids for nanosized materials are mainly fluorocarbon surfactants, and a slight addition will remarkably reduce surface tension of a liquid (e.g., lower that of water from 73 mn/m to 8 mn/m).
[0055] IV. Due to the unique geometric dimension and electric negativity of fluorine atom, the modified nanosized material is highly thermal-stable, and highly resistant to very strong acid, alkali and oxidant.
[0056] V. Finally, fluorocarbon is used as the filming material to remarkably reduce film thickness, keep the chemical and physical properties and color of the original substrate, and greatly improve transparency and permeability.
[0057] From the above analysis, the multi-phobic effect nanosized-structure film prepared according to the method described herein eliminates the demerits of the background technology.
[0058] The following non-limiting examples describe specific processes and compositions for preparing films of multi-phobic effects.
EXAMPLE 1
Modified Nanosized Material
[0059] Add 30 g fluorocarbon surfactants (trade name: FN-80) to 200 ml toluene solvent, after complete dissolution, slowly add 200 g nanosized silica powder into above surfactant-containing solvent, then thoroughly mix the solution to make them completely react, remove toluene, dry the reaction product in oven at 120° C. and finally disperse the dried product with air-flow crusher to obtain white powdered nanosized modified material.
EXAMPLE 2
[0060] Add 10 g nanosized titanium oxide to 800 mL xylene, evenly mix them at room temperature, slowly add 8 g fluorocarbon surfactant to the mixed solution, under ultrasonic dispersion while adding, after addition continue ultrasonic agitation for 10 minutes to make them completely react, remove xylene from the solution to obtain the reaction product of titanium oxide and fluorocarbon surfactant, dry the reaction product in oven under 150° C., and finally disperse the dried product with air-flow crusher to obtain white powdered modified nanosized titanium oxide.
[0061] With the above method other modified powdered nanosized materials can be obtained such as modified nanosized zinc oxide and nanosized alumina.
EXAMPLE 3
Preparation of Nanosized Compounded Powder
[0062] Compound nanosized modified powders prepared in example 1 and 2 at the following proportion:
[0063] 1. Selection of raw materials:
[0064] a. Nanosized bacteria-proof material: silica of size 30 nm;
[0065] b. Nanosized catalysts: titanium oxide of size 20 nm;
[0066] c. Nanosized decomposing material: zinc oxide of size 60 nm;
[0067] d. Nanosized interfacial material: alumina of size 50 nm.
[0068] e. Nanosized surface energy-consuming material: titanium oxide of radium 10 nm.
[0069] 2. Mixing proportion:
a:b:c:d:e=23%:20%:22%:20%:15%
[0070] 3. Technological process:
[0071] Add the above modified nanosized materials as per the above sequence and proportion to mixer, thoroughly mix them at 150 rpm for 30 minutes and then take them out.
EXAMPLE 4
Preparation of Nanosized Filming Paste
[0072] 1. Selection of raw materials
[0073] f. Nanosized modified mixture 0.5%;
[0074] g. Fluorocarbon filming substance perfluoro alkyl sulfuryl alkyl acrylate 5%;
[0075] h. Functional aid: fatty alcohol polyoxyethylene ether, 0.1%;
[0076] i. Dispersing medium: deionized water having conductivity below 0.1.
[0077] 2. Mixing proportion:
f:g:h:i=0.5%:5%:0.1%:94.4%
[0078] 3. Preparation of filming paste:
[0079] Prepare raw materials at the above proportion, add functional aid to dispersing medium (deionized water), accelerate agitation to make functional aid evenly dissolved in dispersing medium, slowly add modified nanosized mixture of Example 3 to the above solution, mix the solution with agitator under 160 rpm for 30 minutes, evenly disperse the nanosized material in liquid phase for 10 minutes with emulsifying machine, disperse fluorocarbon filming substance and slowly add it to the dispersed nanosized liquid phase under slow agitation till even dissolving of the filming substance.
EXAMPLE 5
Preparation of Fabric Nanosized-Structure Film
[0080] Wash the to-be-filmed fibrous fabric, evenly spray the above paste on surface of the fabric twice, dry the paste-sprayed fabric in oven at 150° C. for 1 minute and obtain nanosized-structure filmed fabric.
EXAMPLE 6
Preparation of Nanosized-Structure Film on Glass Product Surface
[0081] Clean the glass product surface, adhere the nanosized filming paste onto glass product surface, take out the pasted glass product, dry it in oven at 120° C. for 5 minutes, take out it again and let it cool down.
EXAMPLE 7
Preparation of Nanosized-Structure Film on Vehicle Body Surface
[0082] Clean the vehicle body surface, evenly spray the nanosized filming paste onto vehicle body surface, and heat the said body in oven at 80° C. for 10 minutes.
EXAMPLE 8
Preparation of Nanosized-Structure Film on Brick, Stone and Wood Wall Surface
[0083] Clean the brick, stone and wood wall surface, evenly spray the above paste onto wall surface, and contact an infrared heating source (100° C.) with the wall surface for 5 minutes to obtain nanosized filmed wall surface.
[0084] All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety.
[0085] 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. Accordingly, the invention is not limited except as by the appended claims. | A method to prepare multi-phobic effects nanosized-structure film and its application are described, which features nanosized silica, titanium oxide and zinc oxide compounded materials of previous size 3-100 nm are in-situ combined with substrate through fluorocarbon surfactants and perfluoro alkyl filming substance under specific conditions to form a nanosized-structure film. The reaction between fluorocarbon surfactants and hydroxyl groups on surfaces of nanosized particles renders the modified nanosized particle and nanosized film having extremely high chemical stability, resistance, and the capacity to repel and disperse water, oil, bacteria, organic dust, gas, electricity, magnetism and light (i.e., multi-phobic effects). This technology may be widely used in surface modification of fabric, chemical fiber, cotton, wool, glass product, brick-stone concrete and wood wall. | 2 |
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates generally to appurtenances for potable water supply systems and, more particularly, is concerned with a dead end potable water main chlorine residual stabilization system.
Description of the Related Art
Devices relevant to the present invention have been described in the related art, however, none of the related art devices disclose the unique features of the present invention.
In U.S. Pat. No. 6,062,259 dated May 16, 2000, Poirier disclosed a method and apparatus for preventing water from stagnating in branches of a municipal water supply system, however, Poirier is different from the present invention in that, as a minimum, it has no solar panel for supplying energy and no computer for controlling the pump. In U.S. Pat. No. 5,921,270 dated Jul. 13, 1999, McCarty disclosed an automatic flush system for water lines. In U.S. Pat. No. 6,635,172 dated Oct. 21, 2003, Newman disclosed an apparatus for the enhancement of water quality in a subterranean pressurized water distribution system. In U.S. Pat. No. 6,880,566, dated Apr. 19, 2005, Newman disclosed an apparatus for the enhancement of water quality in a subterranean pressurized water distribution system. In U.S. Pat. No. 6,948,512 dated Sep. 27, 2005, McKeague disclosed a flushing attachment for a hydrant. In U.S. Pat. No. 8,733,390 dated May 27, 2014, McKeague disclosed an automatic flushing device for municipal water systems.
While these devices may be suitable for the purposes for which they were designed, they would not be as suitable for the purposes of the present invention as hereinafter described. As will be shown by way of explanation and drawings, the present invention works in a novel manner and differently from the related art.
SUMMARY OF THE PRESENT INVENTION
The present invention discloses an environmentally friendly system for automatically and remotely maintaining legally required healthy and acceptable levels of chlorine residual in the dead end branches of potable water mains so as to protect the users from high levels of coliform organisms by recirculation of the stagnant dead end water back to a flowing water main. A pump circulates stagnant water from near the end of the dead end water main back through a tube to a water main having flowing water therein. Thus, stagnant water is evacuated from the problematic dead end branch of the water main back to the flowing water main which, due to fluid dynamics, causes fresh water from the flowing water main to replace the stagnant water as fresh water is circulated back to the area of the dead end water main. The present invention uses a remote photovoltaic solar array mounted on a stanchion as its source of power which is electrically connected to a watertight vault housing a lithium ion battery pack, programmable logic controller (PLC), pump, power cables, flow meter, and test port all designed for being accessible from the surface of the ground for service and/or repair. The pump assembly is controlled by a PLC control panel set to send power from the solar array to the battery pack for recharge, wherein the battery level triggers/actuates the PLC controller to sequence the timer to power the pump which is on a variable timed schedule determined by the dead end pipe size, length and ambient conditions so as to maintain the proper level of chlorine residual.
An object of the present invention is to prevent water in dead end branch water mains from becoming stagnant due to depletion of the residual chlorine caused by dissipation or chloramines decay. A further object of the present invention is to circulate water from a dead end branch water main back to a flowing water main so that the water is refreshed with high chlorine residual water from the flowing water main. A further object of the present invention is to provide a system which can be used to retrofit existing water supply systems having dead end branch water mains commonly found in municipal and rural water supply/distribution systems. A further object of the present invention is to provide a system which is self-contained and can be successfully operated without access to the public power grid wherein the system receives its only source of required energy from a photovoltaic solar panel. A further object of the present invention is to provide a system which can be easily installed requiring only minimal training to a utility operator or contractor. A further object of the present invention is to provide a system which can be easily operated by a user. A further object of the present invention is to provide a system which can be relatively inexpensively operated and maintained.
The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. In the accompanying drawings, like reference characters designate the same or similar parts throughout the several views.
The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of the present invention.
FIG. 2 is a side elevation view of the present invention.
FIG. 3 is a side elevation view of portions of the present invention.
LIST OF REFERENCE NUMERALS
With regard to reference numerals used, the following numbering is used throughout the drawings.
10 present invention 11 pump assembly 12 power assembly 13 tube insertion assembly 14 suction end assembly 15 connection assembly to flowing main 16 dead end 17 flowing main 18 circulation pump 19 lithium ion battery pack 21 pump isolation valve 22 pump inlet line 24 flow meter 25 sampling valve with vacuum breaker 26 pump discharge line 27 pump check valve 28 insertion/isolation valve 30 rigid flexible insert tubing 32 inlet of insert pipe 34 tapping saddle 38 control panel/programmable logic controller 39 power cable 40 photovoltaic solar panel 42 stanchion 43 concrete pier with mounting plate 44 ground 46 vault 48 bolt down cover with gasket seal 50 electrical connection 52 aperture 54 water tight electrical plug and bulkhead socket 56 aperture 58 water tight bulkhead fitting 64 insert/pulling cone 66 sloping head 68 wall of vault 70 tapping sleeve 71 access cover 72 45 degree lateral pipe with flanged end 74 joint 76 pump discharge line 78 dead end main
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following discussion describes in detail at least one embodiment of the present invention. This discussion should not be construed, however, as limiting the present invention to the particular embodiments described herein since practitioners skilled in the art will recognize numerous other embodiments as well. For a definition of the complete scope of the invention the reader is directed to the appended claims. FIGS. 1 through 3 illustrate the present invention which disclosed a method and apparatus for automatically stabilizing the residual chlorine level of water mains containing potable water and which is generally indicated by reference number 10 .
Turning to FIGS. 1 and 2 , therein is shown the present invention 10 wherein a dead end branch water main 78 has its water refreshed from a flowing water main 17 by evacuating by pumping the stagnated water from near the dead end 16 by drawing the water through the inserted rigid flexible insert tube 30 which is connected to the suction side of pump 18 of pump assembly generally indicated by reference number 11 by means of pump inlet line 22 . The water is then pumped through and then out pump discharge line 26 into the water main connection assembly generally indicated by reference number 15 which is attached to the flowing main 17 thereby causing the replacement of the stagnated water associated with the dead end 16 area of the dead end branch water main 78 with the higher chlorine residual water from the flowing water main 17 .
FIG. 1 shows one embodiment of a connection assembly 15 having an insertion/isolation valve 28 mounted onto a saddle-type connector or tapping saddle 34 for connection to flowing water main 17 . FIG. 2 shows a second embodiment of a connection assembly 15 having the insertion/isolation valve 28 attached to or bolted to a sleeve-type connector being a stainless steel or like tapping sleeve 70 for connection to flowing water main 17 .
Suction end assembly generally indicated by reference number 14 is attached to the distal end of the rigid flexible insert tubing 30 which is inserted through the dead end main 78 having an inlet 32 on its distal end. The suction end assembly 14 includes an insert/pulling cone 64 attached near the distal end of insert tubing 30 . The insert/pulling cone 64 has a sloping head or face 66 thereon so that the insert/pulling cone can be slidably inserted through the dead end water main 78 without hanging up or catching on any build up, edge or seam as might occur, e.g., at a joint 74 as a result of joining together pipe sections of the dead end water main. The purpose of the sloping head 66 is to allow the insert/pulling cone 64 to easily pass through the interior of the dead end branch water main 78 .
Tube insertion assembly generally indicated by reference number 13 enables the rigid flexible insert tubing 30 to be inserted into the dead end main 78 and be isolated for service and testing without valving off or otherwise isolating the dead end main 78 . FIG. 1 shows one embodiment of a tube insertion assembly 13 having an insertion/isolation valve 28 mounted onto a saddle-type connector or tapping saddle 34 so that the valve 28 is angled with respect to the dead end main 78 . FIG. 2 shows another embodiment of a tube insertion assembly 13 having the insertion/isolation valve 28 attached to a 45 degree flanged lateral pipe 72 which is attached to a sleeve-type connector being a stainless steel or like tapping sleeve 70 interconnecting the dead end branch main 78 to the pump assembly 11 . Access cover 71 is also provided on tapping sleeve 70 . FIG. 3 shows a more detailed view of the tube insertion assembly 13 and connection assembly 15 .
Pump assembly 11 connects to tube insertion assembly 13 via pump inlet line 22 passing through vault wall 68 through aperture 56 sealed from ground water with water tight bulkhead fitting 58 and then to isolation valve 21 . A pump check valve 27 is connected to the suction side of pump 18 which pump then discharges through pump discharge line 76 to flow meter 24 and then through a second pump isolation valve 21 and then the pump discharge is piped through vault wall 68 using aperture 56 and sealed from ground water by bulkhead fitting 58 . A sampling valve with vacuum breaker 25 is also provided. Pump 18 is controlled by the computer in the PLC control panel 38 and powered by lithium ion battery pack 19 which receives electrical power from power cable 39 passing through vault wall 68 using aperture 52 and seal 54 . Power cable 39 is connected to power assembly 12 . Vault 46 is expected to be water tight having a bolt-down cover with gasket seal 48 thereon which is expected to be accessible from above ground 44 .
Systems power is supplied by power assembly generally indicated by reference number 12 including solar panel 40 serving as the power source disposed on a stanchion 42 and mounted into the ground 44 using a concrete pier with mounting plate 43 . The electrical cable 39 attaches to and passes through the wall 68 of vault 46 via aperture 52 and water tight plug 54 . Miscellaneous electrical 50 connects control panel 38 to the battery pack 19 and pump 18 .
Turning to FIG. 3 , shows a more detailed view of the tube insertion assembly 13 and connection assembly 15 as previously disclosed relative to FIGS. 1 and 2 . The tapping sleeve inlet 70 is provided for receiving insertion tubing 30 in its interior wherein flanged insert valve 28 and an insertable flexible rigid tube 30 is disposed at an angle of about 30-45 degrees with respect to the centerline of water main 78 , the angle being effectively sized to allow for insertion into and retrofitting of an existing underground water supply system so as to ease the installation of tube 30 into water main 78 .
The vault 46 and cover 48 are expected to be made of concrete, cement, fiberglass, or the like, the material being suitable for installation in remote areas, as would be done in the standard manner by one skilled in the art.
The present invention 10 is expected to be installed on existing municipal or rural potable water distribution systems. The steps of the installation process are as follows: 1) locate the dead end water main segments 78 of the water system and measure back to the source main 17 to establish the length of insert tube 30 ; 2) valve off dead end section and excavate the end 16 ; 3) install tapping sleeve/saddle 34 , 70 and insertion valve 28 and tap flowing water main for pump discharge piping 26 ; 4) install tapping sleeve/saddle 34 , 70 to tap dead end water main 78 for circulator tube 30 ; 5) through the sleeve opening of dead end main 78 insert cone 64 and circulator tube 30 and push to the pre-measured end (note, if the dead end is longer than 200 feet or there is interior pipe corrosion this operation may require using a push rod to assist the insertion and some installations may require a second tapping sleeve installed near the source main and the insert be pulled in via poly rope floated down to the first tapping sleeve at the dead end; 6) install flanged valve 28 and pump inlet pipe 26 and backfill allowing for vault 46 ; 7) set vault 46 and connect pipes 22 , 26 to prospective bulkhead fittings 58 and complete backfill; 8) excavate for stanchion base and pour concrete pier with conduit embedded and stainless steel mounting studs; 9) set stanchion 42 and solar panel 40 ; 10) trench in power cable and connect to vault plug 54 and solar plug jack at array and charge battery pack; 11) test for chlorine and determine dead-end volume for PLC programming pump controller clock and start system; 12) check meter located in vault to confirm operation and take water sample for testing residual chlorine; 13) in four hours check meter for gallons moved and retest chlorine residual; 14) recheck every 24 hours for the first three days and then weekly thereafter.
To retrofit the present invention 10 to an existing water supply system the insert/pulling cone 64 having its sloped face 66 is crucial because the outlet 32 could snag on the internal joint seams 74 and formations inside the dead end water main 78 . Also, the flanged insert valve 28 is attached at about a 30-45 degree angle with respect to the dead end main 78 so as to allow the pump inlet tube 22 and insertable flexible rigid tube 30 to be pushed, pulled, or slidably inserted into the existing underground dead end water main 78 which may be several feet, e.g., 3-6 feet, below the surface of the ground 44 .
The present invention 10 is designed for installation and operation in remote areas and is designed to require low maintenance and to have a low operating cost. Therefore, the programmable logic controller 38 is expected to be programmed so as to operate the pump 18 only during periods of time when there is enough available solar energy to do so or when the batteries are sufficiently charged to do so; at other times the pump is expected to be off. It is believed that this operating regimen will allow for the present invention 10 to operate at minimum costs. | System and method for automatically and remotely maintaining acceptable levels of chlorine residual in the dead end branches of potable water mains so as to protect the users from high levels of coliform organisms by pumping stagnant water from the dead end branch back to a flowing water main. A solar panel serves as the source of power with batteries being used to store energy. A water circulation pump evacuates water through an insertable rigid flexible tubing from a point near the distal end of the dead end branch to the nearest flowing water main. A programmable logic controller is used to operate the pump during periods of time when there is enough available solar energy or when the batteries are sufficiently charged. | 4 |
This application is a continuation, of application Ser. No. 07/939,437 filed on Sep. 4, 1992, now abandoned, which is a continuation of Ser. No. 07/675,269 filed on Mar. 26, 1991, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a luminance signal/chrominance signal separation filter which separates luminance signal (hereinafter to be called Y signal or simply Y) and chrominance signal (hereinafter to be called C signal or simply C) independently from composite video signal (hereinafter to be called V signal) which is obtained by frequency-multiplexing C signal in high frequency band of Y signal, particularly to a Y/C separation filter which is adaptive to motion image.
2. Related Art of the Invention
A motion-adaptive Y/C separation filter judges partially whether an image is static or moving and carries out Y/C separation suitable for pixel signal of the respective portions. The present filtering of NTSC signal uses a V signal which is a composite signal obtained by frequency-multiplexing C signal in high frequency band of Y signal. Therefore, a receiver is necessary to undergo Y/C separation, and incomplete separation causes picture quality degradation such as cross color or cross luminance. Accordingly, various kinds of signal processing circuits for improving picture quality such as motion-adaptive Y/C separation ion utilizing a delay circuit having delay time being equal to or higher than vertical scanning frequency (hereinafter, to be called simply a delay circuit) have been proposed. This depends upon the fact that a memory of vast capacity has been developed and utilized for image processing.
FIG. 1 is a block circuit diagram showing an example of a conventional motion-adaptive Y/C separation filter.
In FIG. 1, to an input terminal 1, V signal 201 of NTSC method is inputted to be given to respective input terminals of a filter 4 for extracting an intrafield Y signal, a filter 5 for an extracting interframe Y signal, a color demodulation circuit 6 and a motion detecting circuit 11 for Y signal.
Y signal 202 by intrafield Y/C separation which has undergone Y/C separation by the filter 4 for extracting intrafield Y signal is inputted into a first input terminal of a mixing circuit 14 for Y signal, and Y signal 203 by interframe Y/C separation which has undergone Y/C separation by the filter 5 for extracting interframe Y signal is inputted to a second input terminal of the mixing circuit 14 for Y signal.
In addition, V signal is color-demodulated into two kinds of color difference signals, that is, R-Y signal and B-Y signal. The two kinds of color difference signals are time-divisionally multiplexed by the frequency of a time divisional multiplexer 7. The frequency band of the output signal of the time divisional multiplexer 7 is band-limited by a low-pass filter 8 (hereinafter, to be called LPF) which allows a band lower than 1.5 MHz to be passed. A color difference signal 204 which is band-limited is inputted to respective input terminals of a filter 9 for extracting C intrafield signal, a filter 10 for extracting interframe C signal, and a motion detecting circuit 12 for C signal.
C signal 205 by intrafield Y/C separation which has undergone Y/C separation by the filter 9 for extracting intrafield C signal is inputted to a first input terminal of a C signal mixing circuit 15. In addition, C signal 206 by Y/C separation in a frame which has undergone Y/C separation by the filter 10 for extracting interframe C signal is inputted to a second input terminal of the mixing circuit 15 For C signal.
On the other hand, a signal 207 showing the amount of motion of Y signal detected by the motion detecting circuit 11 for Y signal is inputted to one input terminal of a synthesizer 13, and a signal 208 showing the amount of motion of C signal detected by the motion detecting circuit 12 for C signal is inputted to the other input terminal of the synthesizer 13.
A motion detecting signal 209 which has been synthesized by the synthesizer 13 is inputted to a third input terminal of the mixing circuit 14 for a Y signal and to a third input terminal of the mixing circuit 15 for a C signal respectively, and a motion detecting unit 80 is composed of the motion detecting circuit 11 for Y signal, motion detecting circuit 12 for C signal and synthesizer 13. A Y signal 210 by motion adaptive Y/C separation which is an output of the mixing circuit 14 for Y signal is outputted From an output terminal 2, and a C signal 211 by motion adaptive Y/C separation which is an output of the mixing circuit 15 for C signal is outputted from an outpost terminal 3.
Next, explanation will be given of the operation. In separating a V signal 201, the motion detecting unit 80 judges whether V signal 201 is a signal showing a static image or a moving image by synthesizing respective outputs of the motion detecting circuit 11 for Y signal and the motion detecting circuit 12 for C signal by the synthesizer 13.
The motion detecting circuit 11 for Y signal, as shown in FIG. 2 for example, subtracts at a subtracter 83 a signal which has been obtained by making the V signal 201 inputted from an input terminal 21 to be delayed by one frame at one-frame delay circuit 82 from the directly inputted V signal 201 to calculate one-frame difference, and passes it through a LPF 84 which allows band lower than 2.1 MHz to be passed, then calculates the absolute value thereof at an absolute value circuit 85 and changes it into a signal 207 showing the amount of motion of low frequency component of Y signal at a non-linear transform circuit 86 to output it to an output terminal 81.
The motion detecting circuit 12 for C signal, as shown in FIG. 3 for example, subtracts at a subtracter 89 a signal which has been obtained by making the band-limited color difference signal 204 inputted from the input terminal 23 to be delayed by two frames at a two-frame delay circuit 88 from the directly inputted color difference signal 204 to calculate a two-frame difference, and calculates the absolute value at an absolute value circuit 90. Then the absolute value is changed at a non-linear transform circuit 91 to the signal 208 showing the amount of motion of C signal to be outputted from an output terminal 87.
The synthesizer 13 is so constructed, for example, as to select the larger value between the amount of motion of Y signal 207 and that of C signal 208 and output it. The result of discrimination is expressed by motion coefficient K (0≦K≦1). For example, in the case where an image is discriminated as a complete static image, K=0, and in the case where an image is discriminated as a complete motion image, K=1. It is given as a control signal 209.
Generally, in the case where an image is a static one. Y/C separation is carried out by the filter 5 for extracting interframe Y signal and the filter 10 for extracting interframe C signal utilizing interframe correlation to separate Y signal from C signal.
The filter 5 for extracting interframe Y signal, as shown in FIG. 4 for example, adds at an adder 94 a signal which has been obtained by making the V signal 201 inputted From the input terminal 21 to be delayed by one-frame at a one-frame delay circuit 93 to the directly inputted V signal 201 to calculate a one-frame sum, then extract YF signal 203 to output it to an output terminal 92.
The filter 10 for extracting an interframe C signal, as shown in FIG. 5 for example, adds at an adder 100 a signal which has been obtained by making the color difference signal 204 inputted from the input terminal 23 to be delayed by one-frame at a one-frame delay circuit 99 to the directly inputted color difference signal 204 to calculate a one-frame sum, then extract CF signal 206 to output it to an output terminal 98.
In addition, in the case where an image is a moving one, Y/C separation a is carried out to separate Y signal from C signal by the filter 4 for extracting intrafield Y signal and the filter 9 for extracting intrafield C signal utilizing intrafield correlation.
The filter 4 for extracting intrafield Y signal, as shown in FIG. 6 for example, adds at an adder 97 a signal which has been obtained by making the V signal 201 inputted from the input terminal 21 to be delayed by one-line at a one-line delay circuit 96 to the directly inputted V signal 201 to calculate one-line sum, then extracts Yf signal 202 to output it from an output terminal 95.
The filter 9 for extracting intrafield C signal, as shown in FIG. 7 for example, adds at an adder 103 a signal which has been obtained by making the color difference signal 204 inputted from the input terminal 23 to be delayed by one-line at a one-line delay circuit 102 to the directly inputted color difference signal 204 to calculate one-line sum, then extracts the Cf signal 205 to output it from an output terminal 101.
In a motion-adaptive Y/C separation filter, such filters as the filter 4 for extracting intrafield Y signal and filter 5 for extracting interframe Y signal are juxtaposed and outputs Y signal 210 by motion adaptive Y/C separation from an output terminal 2 by making the mixing circuit 14 for Y signal carry out the following operation according to a control signal 209 being a motion coefficient K synthesized by the motion detecting circuit 12 for C signal.
Y=kYf+(1-k)YF
Here,
Yf : output 202 of Y signal by intrafield Y/C separation
YF: output 203 of Y signal by interframe Y/C separation.
In the above filter, the filter 9 For extracting intrafield C signal and the filter 10 for extracting interframe C signal are juxtaposed in the same way, and outputs C signal 211 by motion adaptive Y/C separation from the output terminal 3 by making the mixing circuit 15 for C signal carry out the following operation according to the control signal 209.
C=kCf+(1-k)CF
Here,
Cf: output of C signal by intrafield Y/C separation
CF: output 206 of C signal by interframe Y/C separation
As the conventional motion-adaptive Y/C separation filter is so constructed as the above, Yf signal by the filter 4 for extracting intrafield Y signal and the YF signal by the filter 5 for extracting interframe Y signal are to be mixed according to of the synthesized amount of motion detected respectively by the motion detecting circuit 11 for Y signal and the motion detecting circuit 12 for C signal. In the same way, Cf signal by the filter 9 for extracting intrafield C signal and CF signal by the filter 10 for extracting interframe C signal are to be mixed according to the synthesized amount of motion.
Accordingly, as there is an excessive change in resolution in the case where an image changes to a motion one from static one, or vice versa because a filter characteristic of static image is totally different from that of motion one, there has been a problem that picture quality degradation in processing motion image is prominent.
SUMMARY OF THE INVENTION
The present invention has been devised in order to solve the above-mentioned problem, and the object thereof is to provide a motion-adaptive Y/C separation filter capable of reproducing image which is high in resolution and low in picture quality degradation, even when dealing with an image that must, be switched many times as above-mentioned.
In the present invention, a circuit, which carries out intraframe Y/C separation by undergoing separation utilizing intrafield correlation, is provided in the case where motion image is detected as first means, and a circuit, which carries out Y/C separation in three fields by undergoing separation utilizing intrafield correlation, is provided in the case where motion image is detected as second means.
The separated Y signal and C signal are respectively mixed with Y signal and C signal which have been separated by undergoing interframe Y/C separation to be used.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a conventional Y/C separation filter.
FIG. 2 is a block diagram of a motion detecting circuit for Y signal.
FIG. 3 is a block diagram of a motion detecting circuit for C signal.
FIG. 4 is a block diagram of a filter for extracting interframe Y signal.
FIG. 5 is a block diagram of a filter for extracting interframe C signal.
FIG. 6 is a block diagram of a filter for extracting intrafield Y signal.
FIG. 7 is a block diagram of a filter for extracting intrafield C signal.
FIG. 8 is a block diagram of a first embodiment of Y/C separation filter of the present invention.
FIG. 9 is a block diagram of a first embodiment of a filter for extracting intraframe Y signal.
FIG. 10 is a t-y view showing array of V signal.
FIG. 11 is a x-y view showing array of V signal.
FIG. 12(a)-(c) are spectrum atlantes of V signal three-dimensional frequency space.
FIG. 13(a)-(c) are spectrum atlantes, in three dimensional frequency space, of Y signal obtained by the first filter for extracting interfield Y signal.
FIG. 14(a)-(c) are spectrum atlantes, in three dimensional frequency space, of Y signal obtained by the second filter for extracting interfield Y signal.
FIG. 15(a)-(c) are spectrum atlantes, in three dimensional frequency space, of Y signal obtained by the third filter for extracting interfield Y signal.
FIG. 16 is a block diagram of a first embodiment of a filter for extracting intraframe C signal in the embodiment shown in FIG. 8.
FIG. 17 is a block diagram of a second embodiment of a filter for extracting intraframe Y signal in the embodiment shown in FIG. 8.
FIG. 18(a)-(c) are distribution diagram of frequency domain of correlation detected for selecting an extracted interframe Y signal A.
FIG. 19(a)-(c) are distribution diagram of frequency domain of correlation detected for selecting an extracted interfield Y signal B.
FIG. 20(a)-(c) are distribution view of frequency domain of correlation detected for selecting an extracted interfield Y signal C.
FIG. 21 is a block diagram of a third embodiment of a filter for extracting intraframe Y signal in the embodiment shown in FIG. 8.
FIG. 22 is a block diagram of a fourth embodiment of a filter for extracting intraframe Y signal in the embodiment shown in FIG. 8.
FIG. 23 is a block diagram of a second embodiment of a filter for extracting intraframe C signal in the embodiment shown in FIG. 8.
FIG. 24 is a block diagram of a fifth embodiment of filter for extracting intraframe Y signal in the embodiment shown in FIG. 8.
FIG. 25(a)-(c) are spectrum atlas of Y signal in three-dimensional frequency space, obtained by the first filter for extracting interfield Y signal relating to the fifth embodiment of the filter for extracting intraframe Y signal.
FIG. 26(a)-(c) are spectrum atlas of Y signal in three dimensional frequency space, obtained by the second filter for extracting interfield Y signal relating to the fifth embodiment of the filter for extracting intraframe Y signal.
FIG. 27(a)-(c) are spectrum atlas of Y signal in three-dimensional frequency space obtained by the third filter for extracting interfield Y signal relating to the fifth embodiment of the filter for extracting intraframe Y signal.
FIG. 28 is a x-y view of showing array of V signal.
FIG. 29 is a block diagram of a third embodiment of a filter for extracting intraframe C signal in the embodiment shown in FIG. 8.
FIG. 30 is a block diagram of a sixth embodiment of a filter for extracting intraframe Y signal in the embodiment shown in FIG. 8.
FIG. 31 is a block diagram of a fourth embodiment of a filter for extracting intraframe C signal in the embodiment shown in FIG. 8.
FIG. 32 is a block diagram of a second embodiment of a filter for Y/C separation of the invention.
FIG. 33 is a block diagram of a filter for extracting Y signal in three fields.
FIG. 34 is a x-y view showing array of V signal,
FIG. 35(a)-(c) are spectrum atlantes of Y signal in three-dimensional frequency space obtained by the first extracting Y signal in three fields.
FIG. 36(a)-(c) are spectrum atlantes of Y signal in three-dimensional frequency space obtained by the second extracting Y signal in three fields.
FIG. 37 (a)-(c) are spectrum atlantes of Y signal obtained in three-dimensional frequency space obtained by the third extracting Y signal in three fields.
FIG. 38 is a block diagram of a second embodiment of a filter for extracting Y signal in three fields.
FIG. 39(a)-(c) are spectrum atlas of Y signal in three-dimensional frequency space obtained by the first extracting Y signal in three fields.
FIG. 40(a)-(c) are spectrum atlas of Y signal in three-dimensional frequency space obtained by the second extracting Y signal in three fields.
FIG. 41(a)-(c) are spectrum atlas of Y signal in three-dimensional frequency space obtained by the third extracting Y signal in three fields.
FIG. 42 is a block diagram of a three embodiment of a filter for extracting Y signal in three fields.
FIG. 43 is a block diagram of a third embodiment of a filter for extracting Y signal in three fields.
FIG. 44 is a block diagram of a filter for extracting intraframe C signal.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the following explanation will be given on the invention referring to drawings.
FIG. 8 is a block diagram showing an embodiment of a motion-adaptive Y/C separation filter of the invention. This figure shows that the filter 4 for extracting intrafield Y signal shown in FIG. 1 is replaced by a filter 16 for extracting intraframe Y signal and the filter 9 for extracting intrafield C signal by a filter 17 for extracting intraframe C signal, and explanation of the others will be omitted as they have been explained in the conventional example. FIG. 9 is a detailed block diagram of the first embodiment of the filter 16 for extracting intraframe Y signal shown in FIG. 8.
As the figure shows, the V signal 101 is inputted to terminal 21. The V signal 101 is inputted to the respective input terminals of a two-pixel delay circuit 25 and a 262-line delay circuit 26.
The signal which has been delayed by two pixels by the two-pixel delay circuit 25 is inputted to respective first input, terminals of subtracters 30, 31, 32 and 41.
The V signal which has been delayed by 262 lines by the 262-line delay circuit 26 is inputted to input terminals of an one-line delay circuit 27 and a four-pixel delay circuit 28, and to a second input terminal of the subtracter 30.
The V signal which has been delayed by one line by the one-line delay circuit 27 is inputted to an input terminal of a two-pixel delay circuit 29. The V signal which has been delayed by four pixels by the four-pixel delay circuit 28 is inputted to a second input terminal of the subtracter 31. The V signal which has been delayed by two pixels by the two-pixel delay circuit 29 is inputted to a second input terminal of the subtracter 32. The output signal of the subtracter 30 is inputted to a first input terminal of a signal selecting circuit 40 and an input of a LPF 33. The output signal of the subtracter 31 is inputted to a second input terminal of a signal selecting circuit 40 and an input terminal of a LPF 34. The output signal of the subtracter 32 is inputted to a third input terminal of the signal selecting circuit 40 and an input terminal of a LPF 35.
The output of the LPF 33 is inputted to an input terminal of an absolute value circuit 36, the output of the LPF 34 is inputted to an input terminal of an absolute value circuit 37, and the output of the LPF 35 is inputted to an input terminal of an absolute value circuit 38, respectively.
The output of the absolute value circuit 36 is inputted to a first input terminal of a minimum value selecting circuit 39, the output of the absolute value circuit 37 is inputted to a second input terminal of the minimum value selecting circuit 39, and the output of the absolute value circuit 38 is inputted to a third input terminal of the minimum value selecting circuit 39, respectively.
The output, of the minimum selecting circuit 39 is inputted to a fourth input terminal of the signal selecting circuit 40, thereby selecting and controlling inputs from the first to the third.
The output of the signal selecting circuit 40 is inputted to an input terminal of an one-line delay circuit 42, a second input terminal of the subtracter 41, and first input terminals of an adder 43 and a subtracter 44, respectively. The output of the one-line delay circuit 42 is inputted to second input terminals of the adder 43 and the subtracter 44. The output of the adder 43 is inputted to a first, input terminal of an adder 46. The output of the subtracter 44 is inputted to an input terminal of a LPF 45. The output of the LPF 45 is inputted to a second input terminal and an adder 46. The output of the subtracter 41 is inputted to a first input terminal of an adder 47 and the output of the adder 46 is inputted to a second input terminal of the adder 47.
The output of the adder 47 is outputted from an output terminal 22 as Y signal 112 by intraframe extracting Y signal.
Next, explanation will be given of the operation.
When taking x-axis in the horizontal direction of an image plane, y-axis in the vertical direction thereof, and t-axis being a time base in the vertical direction against the plane, a three-dimensional space time can be thought of.
FIG. 10 and 11 are views showing a three-dimensional space time. FIG. 10 is a plane comprising t-axis and y-axis, and FIG. 11 is a plane comprising x-axis and y-axis. In FIG. 10, a broken line shows a field, and a solid line shows that a color sub carrier is the same. And at the intersecting points thereof, pixels ◯ and are shown. Symbols n-2 . . . n+1 are field numbers.
In addition, solid lines and broken lines in FIG. 11 respectively show scanning lines of n-th field and n-1-th field respectively, and four kinds of symbols ◯ , , Δ , and show sampled points of a same phase of the color sub carrier by using the same symbols when the V signal is digitized at four times of the color sub carrier fsc (=3.58 MHz), 1-2 . . . 1+2 show line numbers. In addition, in FIG. 10 and 11, ◯ and --, Δ and respectively differ 180° in phase from each other. Now, a picked-up sampled point is indicated by ⊚. In n-th field in which the picked-up sampled point exists, the phase of color sub carrier at the picked-up sampled point differs 180° from that of a and b being one line up and down respectively therefrom, and differs 180° from that of c and d being two points before and behind respectively therefrom.
Thereupon, such filters as a line-comb filter based upon digital circuit, an adaptive Y/C separation filter disclosed in Japanese Patent Application Laid Open No.60-134587, 1985 and so on can be constructed.
As is shown in FIG. 10, as the phase of color sub carrier at the picked-up sampled point differs 180° from that at a sampled point corresponding thereto being one Frame (one frame=2 fields) away therefrom, a filter for interframe Y/C separation can also be constructed.
Moreover, as is understood from FIG. 11, as the phase of color sub carrier differs 180° from that of a sampled point I one line up therefrom and that of sampled points II and III one line down therefrom being respectively located in n-1-th field one field before the n-th field in which the picked-up sampled point exists, interfield Y/C separation can be possible according to the calculation between any of these three points I, II and III and the picked-up sampled point.
In addition, a frequency axis corresponding to the above-mentioned x-axis, y-axis and t-axis, u-axis as a horizontal frequency axis, v-axis as a vertical frequency axis and f-axis as a time frequency axis are used to establish a three-dimensional frequency space comprising u-axis, v-axis and f-axis being orthogonal with each other.
FIG. 12(a) through (c) are projection views of above-mentioned three-dimensional frequency space. FIG. 12(a) is a view of above-mentioned three dimensional frequency space viewed at a slant. FIG. 12(b) is a view of above-mentioned three dimensional frequency space viewed from the negative direction of f-axis, and FIG. 12(c) is a view of above-mentioned three dimensional frequency space viewed from positive direction of u-axis. In the FIG. 12(a) through (c), spectrum distribution of V signal is shown on the three-dimensional frequency space. As can be seen from FIG. 12(a) through (c), the spectrum of Y signal extend with the origin of the three-dimensional frequency space as the center, and spectrum of C signal is located in four spaces like the ones shown in FIG. 12(a) through (c) as I signal and Q signal are quadrature two phase modulated.
But, as in the case of FIG. 12(c), when looking V signal on u-axis, C signal is found only in the second quadrant and the fourth quadrant. This corresponds to the fact that a solid line showing the same phase of the color sub carrier goes up as time passes.
Nevertheless, in the conventional example, as Y/C separation utilizing intrafield correlation is carried out in the case where motion of an image is detected, band limitation is not possible in the direction of f-axis although it is possible in the direction of u-axis and v-axis.
Accordingly, frequency space in which Y signal originally exists is to be separated therefrom as C signal, and as a result, band of Y signal in motion image has been narrowed.
Hereupon, band of Y signal in motion image can be widened by carrying out Y/C separation according to interfield processing as mentioned above.
In FIG. 11 points in n-1-th field, located in the vicinity of the picked-up sampled point ⊚ in n-th field and different 180° in color sub carrier phase from the picked-up sampled point are the sampled points I, II and III. Calculation between the picked-up sampled point and any of these three points enables interfield Y/C separation.
At first, it is possible to take out high frequency component on the three-dimensional frequency space including C signal according to the difference between the picked-up sampled point ⊚ and the sampled point I shown in FIG. 11. When the taken-out component is made to pass through a two-dimensional comb filter 48 consisting of the one-line delay circuit 42, adders 43 and 46, subtracters 44 and LPF 45, C signal can be removed. Y signal can be obtained by adding the above result to low frequency component on the three dimensional frequency space not including C signal which is an output of the subtracter 41. This is called extracted interfield Y signal A.
FIG. 13(a) through (c) show three-dimensional frequency space in the same way as FIG. 12(a) through (c), showing the frequency space in which Y signal exists obtained by extracted interfield Y signal A.
Secondary, it is possible to take out high frequency component in the three-dimensional frequency space including C signal according to the difference between the picked-up sampled point ⊚ and the sampled II. When the taken-out component is made to pass through the above-mentioned two dimensional comb filter, C signal can be removed.
In the following, Y signal can be obtained by the same processing as the above. This is called extracted interfield Y signal B.
FIG. 14 also shows frequency space in which Y signal exists obtained by extracted interfield Y signal B in the same way as in the cases of FIG. 12 and 13.
When FIG. 14(a) through (c) are viewed, it seems that the Y signal includes a part of C signal, however, it is rare that Y signal includes C signal because correlation between Y signal and C signal is strong.
Thirdly, it is possible to take out high frequency component on the three-dimensional frequency space including C signal according to the difference between the picked-up sampled point ⊚ and the sampled point III shown in FIG. 11. When the taken-out component is made to pass through the above-mentioned two-dimensional comb filter, C signal can be removed.
When the same processing is applied, Y signal is obtained. This is called extracted interfield Y signal C.
FIG. 15 also shows frequency space in which Y signal and C signal exist obtained by C signal by interfield Y/C separation.
When FIG. 15 is viewed, it seems that the separated Y signal includes a part of C signal, however, it is rare that Y signal include C signal according to the same reason in the case of FIG. 11.
In order to control selecting adaptively three kinds of interfield Y/C separations, it is necessary to detect correlation between the picked-up sampled point ⊚ and the sampled points I, II and III.
As it is V signal that is inputted to the input terminal 21, in order to detect the correlation, the respective differences should be passed through LPF to detect the correlation of low frequency component of Y signal and make it as a control signal.
Next explanation will be given on operation of a filter for extracting intraframe Y signal having the configuration of FIG. 9.
This invention is characterized by using the optimum filter among the filters for extracting intraframe Y signal including three kinds of interfield calculations, as motion image processing in place of a filter for extracting intrafield Y signal, when a motion detecting unit 80 judges that the image is motion one.
In FIG. 9, V signal 101 inputted from the input terminal 21 is delayed by two pixels by the two-pixel delay circuit 25 and delayed by 262 lines by the 262-line delay circuit 26.
By subtracting V signal which is delayed by two pixels by the two-pixel delay circuit 25 from the output of the 262-line delay circuit 26 at the subtracter 30, an interfield difference for extracted interfield Y signal C can be obtained. The calculation is for obtaining the difference between the picked-up sampled point ⊚ and the sampled point III. When the point d in FIG. 11 is made as a reference, the picked-up sampled point ⊚ is delayed by two pixels. The sampled point III is delayed by 262 lines (262 lines=one field). Accordingly, the difference between the output of the two-pixel delay circuit 25 and the output of the 262-line delay circuit 26 becomes the aimed difference.
By subtracting V signal which is delayed by two pixels by the two-pixel delay circuit 25 from the output of the four-pixel delay circuit 28 at the subtracter 31, an interfield difference for extracted interfield Y signal B can be obtained.
By subtracting V signal which is delayed by two pixels by the two-pixel delay circuit 25 from the output of the two-pixel delay circuit 29, an interfield difference extracted interfield Y signal A can be obtained.
Respective extracted interfield Y signals A and B can be easily understood in the same way as extracted interfield Y signal C when the ◯ point d is made as a reference.
Above-mentioned three kinds of interfield differences is inputted to the signal selecting circuit 40, and is selected by the output of the minimum value selecting circuit 40 to be described later.
An interfield difference being an output of the subtracter 30 passes through the LPF 33 which allows the band lower than 2.1 MHz to be passed, is made to be an absolute value thereof by the absolute value circuit 36, and is inputted to the minimum value selecting circuit 39. The output of the absolute value circuit 36 detects the correlation between the picked-up sampled point and the sampled point III shown in FIG. 11.
An interfield difference being an output of the subtracter 31 passes through the LPF 34 which allows the band lower than 2.1 MHz to be passed, is made to be an absolute value thereof by the absolute value circuit 37, and is inputted to the minimum value selecting circuit 39. The absolute value circuit 37 detects the correlation between the picked-up sampled point and the sampled point II.
An interfield difference being the output of the subtracter 32 passes through the LPF 35 which allows the band lower than 2.1 MHz to be passed is made to be an absolute value thereof by the absolute value circuit 38, and is inputted to the minimum value selecting circuit 39. The absolute value circuit 38 detects the correlation between the picked-up sampled point ⊚ and the sampled point ◯ I shown in FIG. 11.
The minimum value selecting circuit 39 selects the minimum output (whose amount of detected correlation is maximum) among the above-mentioned three kinds of the absolute value outputs to control the signal selecting circuit 40.
That is to say, the signal selecting circuit 40 selects the output of the subtracter 30 in the case where the output of the absolute value circuit 36 is minimum, selects the output of the subtracter 31 in the case where the output of the absolute value circuit 37 is minimum, and selects the output of the subtracter 32 in the case where the output of the absolute value circuit 38 is minimum.
In addition, the output of the signal selecting circuit 40 is subtracted from V signal by the subtracter 41, and low frequency component of three-dimensional frequency space in the direction in which correlation has been detected is obtained. On the other hand, as the output of the signal selecting circuit 40 is high frequency component of three-dimensional frequency in the direction in which correlation has been detected, C signal can be removed by passing it through the two-dimensional comb filter consisting of the one-line delay circuit 42, adders 43 and 46, subtracters 44, LPF 45. By adding output of the subtracter 41 to that of the adder 46 by the adder 47, Y signal 112 by intraframe extracting Y signal can be obtained.
In addition, in FIG. 9, although calculation by using also the one-line delay circuit 42 has been applied in order to remove C signal, separation accuracy will be much more improved in the case where a plurality of line-memories are used and the one-line delay circuit is used at every stored signal of a plurality of lines.
FIG. 16 is a detailed block diagram of the filter for extracting intraframe C signal shown in FIG. 8 of the invention.
In the FIG. 16, to the input terminal 23, color difference signal 104 is inputted. The color difference signal 104 is inputted to the input terminals of a two-pixel delay circuit 61 and a 262-line delay circuit 62 respectively.
The signal which has been delayed by two pixels by the two-pixel delay circuit 61 is inputted to first input terminals of subtracters 66, 67, 68, and 74 respectively.
V signal which has been delayed by 262 lines by the 262-line delay circuit 62 is inputted to input terminals of a one-line delay circuit 63 and a four-pixel delay circuit 64, and to a second input terminal of the subtracter 66.
The signal which has been delayed by one line by the one line delay circuit 63 is inputted to an input terminal of a two-pixel delay circuit 65. The signal which has been delayed by four pixels by the four-pixels delay circuit 64 is inputted to a second input terminal of the subtracter 67. The signal which has been delayed by two pixels by the two-pixel delay circuit 65 is inputted to a second input terminal of the subtracter 68.
The output signal of the subtracter 66 is inputted to a first input terminal of a signal selecting circuit 73 and to an input terminal of the absolute value circuit 69 respectively. The output signal of the subtracter 67 is inputted to a second input terminal of the signal selecting circuit 73 and to an input terminal of the absolute value circuit 70 respectively. The output signal of the subtracter 68 is inputted to a third input terminal of the signal selecting circuit 73 and to an input terminal of an absolute value circuit 73 and to an input terminal of an absolute value circuit 71.
An output of an absolute value circuit 69 is inputted to a first input terminal of a minimum value selecting circuit 72, output of an absolute value circuit 70 is inputted to a second input value of the minimum value selecting circuit 72, and the output of the absolute value circuit 71 is inputted to a third input terminal of the minimum value selecting circuit 72, respectively.
The output of the minimum value selecting circuit 72 is inputted to a fourth input terminal of the signal selecting circuit 73, thereby selecting and controlling inputs from the first to the third.
The output of the signal selecting circuit 73 is inputted to a second input terminal of the subtracter 74. The output of the subtracter 74 is outputted from an output terminal 24 as C signal 115 by intraframe extracting C signal.
Next, explanation on the operation of a filter for extracting intraframe C signal having a configuration shown in FIG. 16.
This invention is characterized by using the optimum filter among filters for extracting intraframe C signal including three kinds of interfield calculations as a motion image processing in place of a filter for extracting intrafield C signal when the motion detecting unit 80 judges the image to be motion one.
Referring to FIG. 16, the color difference signal 104 inputted from the input terminal 23 is delayed by two pixels by the two-pixel delay circuit, 61, and is delayed by 262 lines by the 262-line delay circuit 62.
By subtracting the color difference signal which has been delayed by two pixels by the two-pixel delay circuit 61 from the output of the 262-line delay circuit 62 by the subtracter 66, an interfield difference for extracted interfield C signal C can be obtained.
By subtracting the output of the color difference signal which has been delayed by two pixels by the two-pixel delay circuit 61 from the output of the four-pixel delay circuit 64 by the subtracter 67, an interfield difference for extracted interfield C signal B can be obtained.
The output of the color difference signal which has been delayed by two pixels by the two-pixel delay circuit 61 from the output of the two-pixel delay circuit 65 by the subtracter 68, an interfield difference for extracted interfield C signal A can be obtained.
The above-mentioned three kinds of differences are inputted to the signal selecting circuit 73 and is selected by the output, of the minimum value selecting circuit 72 to be described later.
An interfield difference being an output of the subtracter 66 is made to be the absolute value thereof by the absolute value circuit 69 and is inputted to the minimum value selecting circuit 72. The absolute value circuit 69 detects the correlation between the picked-up sampled point ⊚ and the sampled point III in FIG. 11.
An interfield difference in a field being the output of the subtracter 67 is made to be the absolute value thereof by the absolute value circuit 70 and is inputted to the minimum value selecting circuit 72. The absolute value circuit 70 detects the correlation between the picked-up sampled point ⊚ and the sampled point II in FIG. 11.
An interfield difference being the output of the subtracter 68 is made to be the absolute value thereof by the absolute value circuit 71 and is inputted to the minimum value selecting circuit 72. The absolute value circuit 71 detects the correlation between the picked-up sampled point ⊚ and the sampled point I shown in FIG. 11.
The minimum value selecting circuit 72 selects the minimum output (whose amount of detected correlation is maximum) among the above-mentioned three kinds of absolute value outputs, thereby controlling the signal selecting circuit 73.
That is to say, the signal selecting circuit 73 selects the output of the subtracter 66 in the case where the output of the absolute value circuit 69 is minimum, selects the outpost of the subtracter 67 in the case where the output of the absolute value circuit 70 is minimum, and selects the output of the subtracter 68 in the case where the output of the absolute value circuit 71 is minimum.
Moreover, the output of the signal selecting circuit 73 is subtracted from the color difference signal by the subtracter 74, and low frequency component of three-dimensional frequency space in the direction in which the correlation has been detected can be obtained.
FIG. 17 is a detailed block diagram of a second embodiment of a filter 16 for extracting intraframe Y signal shown in FIG. 8 of the invention.
The difference between the filters shown in FIG. 17 and FIG. 9 is only the method for detecting interfield correlation. This embodiment uses a method for detecting a direction in which spectrum of Y signal extends in three-dimensional frequency space, as the method for detecting correlation of V signal.
When illustrating the frequency band detecting the extension of the spectrum of Y signal for selecting and controlling three kinds of interfield extracting Y signal, they express themselves in solid line portions in FIG. 18, 19 and 20 respectively.
FIG. 18 shows a frequency band detecting the extension of Y signal spectrum for selecting extracted interfield Y signal A. This band can be detected by making the difference between the picked-up sampled point ⊚ and the sampled point ◯ located one line lower than the sampled point I shown in FIG. 11 pass through LPF.
FIG. 19 shows a frequency band detecting the extension of Y signal spectrum for selecting extracted interfield Y signal B. This band can be detected by making the sum between the picked-up sampled point ⊚ and the sampled point II shown in FIG. 11 pass through BPF.
FIG. 20 shows a frequency band detecting the extension of Y signal spectrum for selecting extracted interfield Y signal C. This band can be detected by making the sum between the picked-up sampled point ⊚ and the sampled point III shown in FIG. 11 pass through BPF.
Next, explanation will be given only on the interfield correlation detecting circuit different from the one shown in FIG. 9 among filters for extracting intraframe Y signal having the configuration of FIG. 17.
In FIG. 17, same numerals are used on the same portions as in FIG. 9.
The output of the 262-line delay circuit 26 and the output of the two-pixel delay circuit 25 are added by an adder 54, and the result of the above is made to pass through a BPF 57 which allows a band higher than 2.1 MHz to be passed, then made to be the absolute value thereof by the absolute value circuit 36, and inputted to a maximum value selecting circuit 49. The output of the absolute value circuit 36 detects the correlation between the picked-up sampled point ⊚ and the sampled point III shown in FIG. 11.
The output of the 262-line delay circuit 26 is delayed by four pixels by a two-pixel delay circuit 52 and 53. The output of the two-pixel delay circuit 53 and the output of the two-pixel delay circuit 25 are added by an adder 55, and the result of the above is made to pass through a BPF 58 which allows a band higher than 2.1 MHz to be passed, then made to be the absolute value thereof by the absolute value circuit 37 and inputted to the maximum value selecting circuit 49. The absolute value circuit. 37 detects the correlation between the picked-up sampled point ⊚ and the sampled point 538 II in FIG. 11.
The output of the two-pixel delay circuit 52 and the output of the two-pixel delay circuit 25 are added by a subtracter 56, and the result of the above is made to pass through a LPF 59 which allows a band lower than 2.1 MHz to be passed, then is made to be the absolute value thereof by the absolute value circuit 38, and inputted to the maximum value selecting circuit 49. The absolute value circuit 38 detects the correlation between the picked-up sampled point ⊚ and the sampled point I shown in FIG. 11.
The maximum value selecting circuit 49 selects the maximum output (whose amount of detected correlation is maximum) among the above-mentioned three kinds of absolute value outputs, thereby controlling the signal selecting circuit, 40.
FIG. 21 is a detailed block diagram of a third embodiment of the filter 16 for extracting intraframe Y signal shown in FIG. 8 of the invention.
The differece between the filter shown in FIG. 21 from that in FIG. 9 is that it uses the optimum three kinds of filters for extracting interfield C signal. Explanation will be given only on the interfield correlation detecting circuit different from that shown in FIG. 9 among the filters for extracting intraframe Y signal having the configuration of FIG. 21. In FIG. 21, same numerals are used on the same portions as in FIG. 9.
The output of the two-pixel delay circuit 25 is inputted to the first input terminals of the subtracters 30, 31, 32 and 41, respectively, as well as to a first terminal of the signal selecting corciut 51. The output of the two pixel delay circuit 25 is also inputted to a first input terminal of the signal selecting circuit 51. The output of the subtracter 30 is inputted to a second input terminal of the signal selecting circuit. 51 and to the LPF 33. The output of the subtracter 31 is inputted to a third input terminal of the signal selecting circuit 51 and to the LPF 34. The output of the subtracter 32 is inputted to a fourth input terminal of the signal selecting circuit 51 and to the LPF 35. The outputs of the LPFs 33, 34, and 35 are inputted to the absolute value circuits 36, 37 and 38 respectively in the same way as in the case of FIG. 9. The output of the absolute value circuit 36 is inputted to first input terminals of the maximum value selecting circuit 49 and the minimum value selecting circuit 89, respectively. The absolute value circuit 36 detects the correlation between the picked-up sampled point ⊚ and the sampled point III in FIG. 11. The output of the absolute value circuit 87 is inputted to second input terminals of the maximum value selecting circuit 49 and the minimum value selecting circuit 39. The absolute valise circuit 37 selects the correlation between the picked-up sampled point ⊚ and the sampled point II in FIG. 11. The output of the absolute value circuit 38 is inputted to third input terminals of the maximum value selecting circuit 49 and the minimum value selecting circuit 39, respectively. The absolute value circuit 38 detects the correlation between the picked-up sampled point ⊚ and the sampled point I in FIG. 11. The output of the maximum value selecting circuit 49 is inputted to a first input terminal of a threshold judging circuit 50. The output of the minimum selecting circuit 39 is inputted to a second input terminal of the threshold judging circuit 50 and to a fifth input terminal of the signal selecting circuit 51. The output of the threshold judging circuit 50 is inputted to a sixth input terminal of the signal selecting circuit 51. The threshold judging circuit 50 controls the signal selecting circuit 51 to select the output of the two-pixel delay circuit 25 in either the case where the maximum value of three kinds of interfield correlations is smaller than a first threshold α or the case where the minimum value of three kinds of interfield correlations is larger than a second threshold β thereby extracting the C signal. On the other hand, in either the case where the threshold judging circuit 50 judges that the maximum value of three kinds of interfield correlations is larger than the first threshold α or the minimum value of three kinds of interfield correlations is smaller than the second threshold β, according to the output of the minimum value selecting circuit 39, the signal selecting circuit 51 is controlled to select the output of the subtracter 30 in the case where the output of the absolute value circuit 36 is minimum, select the output of the subtracter 31 in the case where the output of the absolute value circuit 37 is minimum, and select the output of the subtracter 32 in the case where the output of the absolute value circuit 38 is minimum. Here there is a relation α<β.
FIG. 22 is a detailed block diagram of a fourth embodiment of the filter for extracting intraframe Y signal shown in FIG. 8 of the invention.
The only difference between the filter shown in FIG. 22 from that shown in FIG. 21 is the method for detecting interfield correlation. Here, in the same way as in the case of the embodiment of FIG. 17, a method for detecting a direction in which Y signal spectrum extends in three-dimensional frequency space is used as a method for detecting correlation of V signal.
Only difference of the filter for extracting intraframe Y signal having the configuration of FIG. 22 from those shown in FIG. 9, FIG. 17 and FIG. 21 will be explained. In FIG. 22, same numerals are used to the same portions as in FIG. 9, FIG. 17 and FIG. 21.
The output of the minimum value selecting circuit 39 is inputted to the first input terminal of the threshold judging circuit 50. The output of the maximum value selecting circuit 49 is inputted to the second input terminal of the threshold judging circuit 50 and to the fifth input terminal of the signal selecting circuit 51. The output of the threshold judging circuit 50 is inputted to the sixth input terminal of the signal selecting circuit 51. The threshold judging circuit 50 controls the signal selecting circuit 51 to select the output of the two pixel delay circuit 25 only, thereby extracting an intrafield C signal in either the case where the maximum value of three kinds of interfield correlations is smaller than the first threshold α or the minimum value of three kinds of interfield correlations is larger than the second threshold β. On the other hand, in the case where the threshold judging circuit 50 judges that the maximum value of three kinds of interfield correlations is larger than the first threshold α or the minimum value of three kinds of correlations is smaller than the second threshold β, according to the output of the maximum value selecting circuit 49, the signal selecting circuit 51 selects the output of the subtracter 30 in the case where the output of the absolute value circuit 36 is maximum, the output of the subtracter 31 in the case where the output of the absolute value circuit 37 is maximum, and selects the output of the subtracter 32 in the case when the output of the absolute value circuit is maximum. Here, there is a relationship α<β.
FIG. 23 is a detailed block diagram of a second embodiment of a filter 17 for extracting intraframe C signal shown in FIG. 8 of the invention.
The difference of the filter shown in FIG. 23 from that shown in FIG. 16 is that the optimum filter among four kinds of filters including a filter for extracting intrafield Y signal as well as three kinds of filters for extracting interfield Y signal.
Explanation will be given only on an interfield correlation detecting circuit being different from that shown in FIG. 16 among filters for extracting intraframe C signal having the configuration of FIG. 23. In FIG. 23, same numerals are used on the same portions shown in FIG. 16.
The output of the two-pixel delay circuit 61 is inputted to first input, terminals of the subtracters 66, 67, 68 arid 74 as well as to a filter 75 for extracting intrafield Y signal. The output of the filter 75 for extracting intrafield Y signal is inputted to a first input terminal of a signal selecting circuit 78. The output of the subtracter 66 is inputted to a second input terminal of the signal selecting circuit 78 and the absolute value circuit 69. The output of the subtracter 67 is inputted to a third input terminal of the signal selecting circuit 78 and the absolute value circuit 70. The output of the subtracter 68 is inputted to a fourth input terminal of the signal selecting circuit 78 and the absolute value circuit 71. The output of the absolute value circuit 69 is inputted to a maximum value selecting circuit 76 and a first input terminal of the minimum value selecting circuit 72 respectively. The absolute value circuit 69 detects the correlation between the picked-up sampled point ⊚ and the sampled point III. The output of the absolute value circuit 70 is inputted to the maximum value selecting circuit 76 and the second input terminal of the minimum value selecting circuit 72, respectively. The absolute value circuit 70 detects the correlation between the picked-up sampled point ⊚ and the sampled point II in FIG. 11. The output of the absolute value circuit 71 is inputted to the maximum value selecting circuit 76 and a third input terminal of the minimum value selecting circuit 72 respectively. The absolute value circuit 71 detects the correlation between the picked-up sampled point ⊚ and the sampled point I in FIG. 11. The output of the maximum value selecting circuit 76 is inputted to a first input terminal of a threshold judging circuit 77. The output of the minimum value selecting circuit 72 is inputted to a second input terminal of the threshold judging circuit 77 and a fifth input terminal of the signal selecting circuit 78. The output of the threshold judging circuit 77 is inputted to a sixth input terminal of the signal selecting circuit 78. The threshold judging circuit 77 controls the signal selecting circuit 78 to select the output of the filter 75 for extracting intrafield Y signal in either the case where the maximum value of three kinds of interfield correlations is smaller than the first threshold value α or the minimum value of three kinds of interfield correlations is larger than the second threshold value β. On the other hand, in either the case where the maximum value of three kinds of interfield correlation is judged to be larger than the first threshold α or the minimum value of three kinds of interfield correlation is judged to be smaller than the second threshold β by the threshold judging circuit 77, according to the output of the minimum value selecting circuit 72, the signal selecting circuit 78 is controlled to select the output of the subtracter 66 in the case where the output of the absolute value circuit 69 is minimum, select the output of the subtracter 67 in the case where the absolute value circuit 70 is minimum, and select the output of the subtracter 68 in the case where the output of the absolute value circuit 71 is minimum, respectively. Here, there is a relationship α<β.
The output of the signal selecting circuit 78 is subtracted by the subtracter 74 from the color difference signal being the output of the two-pixel delay circuit 61, and is outputted from the output terminal 24 as an extracted intraframe C signal 115.
In addition, in FIG. 8, a circuit for motion-adaptive processing of color difference signal consisting of a filter 17 for extracting intraframe C signal, filter 10 for extracting interframe C signal, and color signal mixing circuit 15 makes a time-division color difference signal 104 as its input, however, it is also possible to construct so that the color difference signal process motion adaptively, separately from each other by additionally juxtaposing the same configuration as the filter 17 for extracting intraframe C signal, filter 10 for extracting interframe C signal and color signal mixing circuit 15.
Explanation will be given further on another embodiment. As mentioned before, in FIG. 11, the points locating in the vicinity of the picked-up sampled point ⊚ in n-1-th field and being different 180° in color sub carrier phase are the sampled points I, II, and III. Calculation between the picked-up sampled point between any of these three points enables interfield Y/C separation.
FIG. 24 is a block diagram of a fifth embodiment of a filter for extracting intraframe Y signal.
At first, high frequency component in three-dimensional frequency space including C signal can be taken out according to the difference between the picked-up sampled point ⊚ and sampled point I shown in FIG. 11. When the component is made to pass through a two-dimensional comb filter 52 consisting of a one-line delay circuit 545, adders 547 and 550, subtracter 546 and LPF 549 shown in FIG. 24, C signal can be removed. When this result and low frequency component in three-dimensional frequency space not including C signal being the output of a subtracter 548 are added, Y signal can be obtained. This is called extracted interfield Y signal A.
FIG. 25 shows a three-dimensional frequency space similarly to FIG. 12, and shows frequency space in which Y signal exists obtained by extracted interfield Y signal A.
Secondary, high frequency component in three-dimensional frequency space including C signal can be taken out according to the difference between the picked-up sampled point ⊚ and the sampled point II shown in FIG. 11. When the component is made to pass through the above-mentioned two-dimensional comb filter, C signal can be removed. When same processing as the above is applied, Y signal can be obtained. This is called extracted interfield Y signal B.
FIG. 26 shows a frequency space in which Y signal exist obtained also by extracted interfield Y signal B. When FIG. 26 is viewed, it seems that the separated Y signal includes a part of C signal, however, it is rare that Y signal includes C signal because the correlation between Y signal and C signal is strong.
Thirdly, high frequency component in three-dimensional frequency space including C signal can be taken out according to the difference between the picked-up sampled point ⊚ and the sampled point III. When the component is made to pass through the above-mentioned two-dimensional comb filter, C signal can be removed. When the same processing is applied as the above, Y signal is obtained. This is called extracted interfield Y signal. C.
FIG. 27 shows a frequency space in which Y signal exist obtained also by extracted interfield Y signal C. When FIG. 27 is viewed, it seems that the separated Y signal includes a part of C signal, however, it is rare that Y signal includes C signal according to the same reason as above-mentioned.
In order to control selecting adaptively these three kinds of extractings of interfield Y signal, correlations between the picked-up sampled point ⊚ and the sampled points I, II and III is needed to be detected. As it is V signal that is inputted to an input terminal 521, a difference of sampled points whose phase of color sub carrier in n-1-th field and n+1-th field is same is used.
Next, explanation will be given of the operations of a filter for extracting intraframe Y signal having the configuration of FIG. 24. The present invention is characterized by using the optimum filter among filters for extracting intraframe Y signal including three kinds of interfield calculations in place of the filter for extracting intrafield Y signal as the motion image processing, when the motion detecting unit 80 judges an image to be the motion one.
In FIG. 24, V signal 701 inputted from an input terminal 521 is delayed by 263 lines by a 263-line delay circuit 525, then is delayed by two pixels by a two-pixel delay circuit 526, and is delayed by 262 lines by a 262-line delay circuit 527.
By subtracting V signal which has been delayed by 262 pixels by the two-pixel delay circuit 526 from the output of the 262-line delay circuit 527 by a subtracter 531, an interfield difference for extracted interfield Y signal C can be obtained.
By subtracting V signal which has been delayed by two pixels by the two-pixel delay circuit 526 from an output of a four-pixel delay circuit 528 by a subtracter 532, an interfield difference for extracted interfield Y signal B can be obtained.
By subtracting V signal which has been delayed by two pixels by the two-pixel delay circuit 526 by a subtracter 533 from an output of a two-pixel delay circuit 530, an interfield difference for extracted interfield Y signal A can be obtained.
The above-mentioned three kinds of interfield differences are inputted to a signal selecting circuit 544 and are selected by an output of a minimum value selecting circuit 543.
In this embodiment, n-1-th field, n-th field and n+1-th field are related to correlation detection. FIG. 28 shows sampled points IV, V and VI located in n+1-th field whose phases of color sub carrier differ 180° from that of the picked-up sampled point located in n-th field.
At first, in order to select, extracted interfield Y signal A, it is necessary to obtain the absolute value of the difference between a sampled point; I in n-1-th field shown in FIG. 11 and a sampled point IV in n+1-th field shown in FIG. 28.
Next, in order to select extracted interfield Y signal B, it is necessary to obtain the absolute value of the difference between a sampled point II in n-1-th field and a sampled point V in n+1-th field.
Moreover, in order to select extracted interfield Y signal C, it is necessary to obtain the absolute value of the difference between a sampled point III in n-1-th field shown in FIG. 11 and a sampled point VI in n+1-th field shown in FIG. 28.
Three kinds of filters for extracting interfield Y signal is selected and controlled by comparing amount of detected interframe correlations obtained from the above result.
In FIG. 24, V signal 701 inputted from the input terminal 521 is inputted to the 263-line delay circuit 525 as well as to input terminals of a one-line delay circuit 534 and a two-pixel delay circuit 536. The output of the 263-line delay circuit is used to construct three kinds of filters for extracting interfield Y signal.
The output of the 262-line delay circuit 527 is subtracted by a subtracter 537 from an output of a four-pixel delay circuit 535, made to be the absolute value thereof by an absolute value circuit 540, inputted to the minimum value selecting circuit 543, and detects the correlation between the sampled points III and VI shown in FIG. 11 and FIG. 28.
The output of the four-pixel delay circuit 528 is subtracted by a subtracter 538 from the output of the one-line delay circuit 534, made to be the absolute value thereof by the absolute value circuit 541, inputted to the minimum value selecting circuit 543, and detects the correlation between the sampled points II and V shown in FIG. 11 and FIG. 28.
The output of the two-pixel delay circuit 530 is subtracted by a subtracter 539 from the output of the two-pixel delay circuit 536, made to be absolute value thereof by an absolute value circuit 542, inputted to the minimum value selecting circuit 543, and detects the correlation between the sampled points I and IV shown in FIG. 11 and FIG. 28.
The minimum value selecting circuit 543 selects the minimum absolute output among the above-mentioned three kinds of the absolute outputs, that is, the one is selected whose correlation between the sampled points among correlations between the sampled points in three different directions is maximum, each direction being made by connecting the picked-up sampled point with each sampled point separated by one frame from the picked-up sampled point which is the center, and controls the signal selecting circuit 544.
That is to say, the signal selecting circuit 544 selects the output of the subtracter 531 in the case where the output of the absolute value circuit 540 is minimum, selects the output of the subtracter 532 in the case where the output of the absolute value circuit 541 is minimum, and selects the output of the subtracter 533 in the case where the output of the absolute value circuit 542, respectively.
Moreover, the output of the signal selecting circuit 544 is subtracted by the subtracter 548 from V signal to obtain low frequency component in three-dimensional frequency space in the direction in which correlation has been detected. On the other hand, as the output of the signal selecting circuit 544 is the high frequency component of three-dimensional frequency in the direction in which correlation has been detected, by making it pass through the two-dimensional comb filter 52 consisting of the one-line delay circuit 545, adders 547 and 550, subtracter 546 and LPF 549, C signal can be removed. By adding the outputs of the subtracter 548 and the adder 550 by an adder 551, Y signal 712 by intraframe extracting Y signal can be obtained.
In addition, in FIG. 24, in order to remove C signal, calculation including the one-line delay circuit 545 is applied, however, separation accuracy is much more improved in the case where calculation is carried out in which one line delay circuit is used at every signal stored plurality of lines by using a plurality of line memories.
FIG. 29 is a detailed block diagram of a third embodiment of the filter 17 for extracting intraframe C signal. In the figure, to an input terminal 523, color difference signal 704 is inputted. Reference numeral 555 designates a 263-line delay circuit, 556, 560 and 566 two-pixel delay circuits, 557 262-line delay circuit, 568 and 565 four-pixel delay circuits, 559 and 564 one-line delay circuits, 561, 562 and 563 adders, 567, 568 and 569 subtracters, 570, 571 and 572 absolute value circuits for outputting absolute values, 573 a minimum value selecting circuit for judging and outputting the minimum value among values of three inputs, and 574 a signal selecting circuit For selecting and outputting one of three inputs. The output of the signal selecting circuit 574 is outputted from an output terminal 524 as C signal 715 by intraframe extracting C signal.
Next, explanation will be given of a filter for extracting intraframe C signal having the configuration of FIG. 29. The present invention is characterized by using the optimum filter among filters for extracting intraframe C signal including three kinds of interfield calculations in place of a filter for extracting intrafield C signal as a motion image processing when the motion detecting unit 80 judges an image to be a motion one.
In FIG. 29, color difference signal 704 inputted from the input terminal 523 is delayed by 263 lines by the 263-line delay circuit 556, then is delayed by two pixels by the two-pixel delay circuit 556, and is delayed by 262 lines by the 262-line delay circuit 557.
By adding the color difference signal which has been delayed by two pixels by the two-pixel delay circuit 556 and the output of the 262-line delay circuit 557 by an adder 561, an interfield sum by extracted interfield C signal B can be obtained.
By adding the color difference signal which has been delayed by two pixels by the two-pixel delay circuit 556 and the output of the four-pixel delay circuit 558 by an adder 562, an interfield sum by extracted interfield C signal B can be obtained.
By adding the color difference signal which has been delayed by the two-pixel delay circuit 556 and the output of the two-pixel delay circuit 560 by an adder 563, an interfield sum by extracted interfield C signal A can be obtained.
The above-mentioned three kinds of interfield sums are inputted to the signal selecting circuit 574 and selected by the output of the minimum value selecting circuit 573.
The correlation detection for adaptively selecting these three kinds of extractings of interfield C signal depends upon the interframe correlation detection similarly to the embodiment shown in FIG. 24.
In FIG. 29, the color difference signal 704 inputted from the input terminal 523 is inputted to the 263-line delay circuit 555 as well as to input terminals of a one-line delay circuit 564 and the two-pixel delay circuit 566. The output of the 263-line delay circuit 555 is used for constructing three kinds of filters for extracting interfield C signal.
The output of the 262-line delay circuit 557 and the output of the four-pixel delay circuit 565 is subtracted by a subtracter 567, made to be the absolute value thereof by the absolute value circuit 570 and inputted to the minimum value selecting circuit 573, and detects the correlation between the sampled points III and VI shown in FIG. 11 and FIG. 28.
The output of the four-pixel delay circuit 558 is subtracted from the output of the one-line delay circuit 564 by a subtracter 568, made to be the absolute value thereof by the absolute value circuit 571, inputted to the minimum value selecting circuit 573 and detects the correlation between the sampled points II and V shown in FIG. 11 and FIG. 28.
The output of the two-pixel delay circuit 560 is subtracted from the output of the two-pixel delay circuit 566 by a subtracter 569, made to be the absolute value thereof by the absolute value circuit 572, inputted to the absolute value selecting circuit 573, and detects the correlation between the sampled points I and IV shown in FIG. 11 and FIG. 28.
The minimum selecting circuit 573 selects the minimum output among the above-mentioned three kinds of absolute value outputs, that is, the one is selected whose correlation between the sampled points among correlations between sampled points in three different directions is maximum, each direction being made by connecting the picked-up sampled point with each sampled point separated by one frame from tile picked-up sampled point which is the center, and controls the signal selecting circuit 574.
That, is to say, the signal selecting circuit 574 selects the output of the adder 561 in the case where the output of the absolute value circuit 570 is minimum, selects the output of the adder 562 in the case where the absolute value circuit 571 is minimum, and selects the output of the adder 563 in the case where the output of the absolute value circuit 572 is minimum, respectively.
In addition, in FIG. 8, the motion-adaptive processing of the color difference signal comprising the filter 17 for extracting intraframe C signal, the filter 10 for extracting interframe C signal, and the C signal mixing circuit 15 makes color difference signal 104 which has been time-division multiplexed as its input signal, however, it is also possible to motion-adaptively process the color difference signal independently by juxtaposing the same configuration as the filter 17 for extracting intraframe C signal, filter 10 for extracting interframe C signal, and C signal mixing circuit 15.
In the filter 16 for extracting intraframe Y signal shown in FIG. 24, three kinds of filters for extracting interfield Y signal are adaptively selected, however, in the following embodiment, the optimum filter is used among four kinds of filters including a filter for extracting intrafield Y signal as well as three kinds of filters for extracting interfield Y signal.
FIG. 30 is a block diagram of a sixth embodiment of the filter for extracting intraframe Y signal. In FIG. 30, same numerals are used on the same portions shown in FIG. 24.
Reference numeral 552 designates a signal selecting circuit selecting and outputting one of four inputs, 553 designates a threshold judging circuit judging whether respective two inputs exceed a certain threshold or not and outputting a control signal, and 554 designates the maximum value selecting circuit judging the maximum value of values of three inputs and outputting a control signal.
The output of the two-pixel delay circuit 526 is inputted to first input terminals of the subtracters 531, 532 and 533 as well as to the signal selecting circuit 552. This input does not carry out interfield calculation. When this input is selected in the signal selecting circuit 552, the processing for extracting intrafield Y signal is carried out.
The output of the absolute value circuit 540 is inputted to the minimum selecting circuit 543 and the maximum value selecting circuit 554. The output of the absolute value circuit 541 is inputted to the minimum value selecting circuit 543 and the maximum value selecting circuit 554. The output of the absolute value circuit 542 is inputted to the minimum value selecting circuit 543 and the maximum value selecting circuit 554.
The output of the maximum value selecting circuit 554 is inputted to a first input terminal of the threshold judging circuit 553. The output of the minimum value selecting circuit 543 is inputted to a second input terminal of the threshold judging circuit 553 and to a fifth input terminal of the signal selecting circuit 552. The output of the threshold judging circuit 553 is inputted to a sixth input terminal of the signal selecting circuit 552. The threshold judging circuit 553 controls the signal selecting circuit 552 to select the output of the two-pixel delay circuit 526 in either the case where the maximum value of three kinds of interframe correlations is smaller than the first threshold α or the minimum value of three kinds of interframe correlations is larger than the second threshold β. On the other hand, the threshold judging circuit 553 judges either tile case where the maximum value of three kinds of interframe correlations is larger than the first threshold α or the minimum value of three kinds of interframe correlations is smaller than the second threshold β, according to the output of the minimum selecting circuit 543, the signal selecting circuit 552 selects the output of the subtracter 531 in the case where the output of the absolute value selecting circuit 540 is minimum, selects the output of the subtracter 532 in the case where the output of the absolute value circuit 541 is minimum, and selects the output of the subtracter 533 in the case where the output of the absolute value circuit 542 is minimum, respectively. Here, there is a relationship α<β.
An output of an adder 551 is outputted from an output terminal 522 as an extracted intraframe Y signal 712.
In the filter 17 for extracting intraframe C signal in the embodiment shown in FIG. 29, three kinds of filters for extracting interfield C signal are adaptively select-controlled, however, in a following embodiment, optimum filter among four kinds of filters including a filter for extracting intrafield C signal as well as three kinds of filters for extracting interfield C signal is used.
FIG. 31 is a detailed block diagram of a fourth embodiment of the filter 17 for extracting intraframe C signal.
In FIG. 31, same numerals are used on the same portions shown in FIG. 26. Reference numeral 575 designates a filter for extracting intrafield C signal which extracts and outputs C signal according to an intrafield calculation, 576 designates a signal selecting circuit which selects and outputs one among four inputs, 577 designates a threshold judging circuit which judges whether respective two inputs exceed a certain threshold or not and outputs a control signal, and 578 designates a maximum value selecting circuit which judges the maximum value of the values of three inputs and outputs a control signal.
The output of the two-pixel delay circuit 556 is inputted to first inputs of the adders 561, 562, and 563 as well as to the filter 575 for extracting intrafield C signal. The output of the filter 575 for extracting intrafield C signal is inputted to the signal selecting circuit 576.
The output of the absolute value circuit 570 is inputted to the minimum value selecting circuit 573 and the maximum value selecting circuit 578. The output of the absolute value circuit 571 is inputted to the minimum value selecting circuit 573 and the maximum value selecting circuit 578. The output of the absolute value circuit 572 is inputted to the minimum value selecting circuit 573 and the maximum value selecting circuit 578.
The signal selecting circuit 576, in the same way as the signal selecting circuit 552 shown in FIG. 30, is controlled by the threshold judging circuit 553 and the minimum value selecting circuit 543.
The output of the signal selecting circuit 576 is outputted from the output terminal 524 as an extracted intraframe C signal 715.
In short, the filter 16 for extracting intraframe, Y signal and the filter 17 for extracting intraframe C signal as shown in FIG. 8, are used in place of the conventionally used filter 4 for extracting intrafield Y signal and the filter 9 for extracting intrafield C signal, as shown in FIG. 1.
A following embodiment differs in extracting Y signal from the embodiment shown in FIG. 8 in the point that the filter 5 for extracting interframe Y signal and a filter for extracting Y signal in three fields are used.
FIG. 32 is a block diagram of a second embodiment thereof.
FIG. 32 is a view showing that the filter 4 for extracting intrafield Y signal is replaced by a filter 76 for extracting Y signal in three fields, and the filter 9 for extracting intrafield C signal is replaced by the filter 17 for extracting intraframe C signal, and explanation on other parts will be omitted because they were explained in the conventional example.
FIG. 33 is a detailed block diagram of a first embodiment of the filter 76 for extracting Y signal in three fields shown in FIG. 32.
In the figure, to an input terminal 721, V signal 201 is inputted. The V signal is inputted to input terminals of a 263-line delay circuit 725, one-line delay circuit 726 and to first input terminals of a subtracter 729 and adder 733, respectively.
The V signal which has been delayed by 268 lines by the 263-line delay circuit 725 is inputted to an input terminal of a two-pixel delay circuit 727, and to second input terminals of the subtracter 729 and adder 733, respectively. The V signal which has been delayed by two pixels by the two-pixel delay circuit 727 is inputted to first input terminals of subtracters 734 and 735. The V signal which has been delayed by one line by the one-line delay circuit 726 is inputted to an input terminal of a four-pixel delay 732 circuit 728 and to a second input terminal of the subtracter 784, respectively. The V signal which has been delayed by four pixels by the four-pixel delay circuit 728 is inputted to a second input terminal of the subtracter 735.
The output signal of the subtracter 729 is inputted to input terminals of a two-pixel delay circuit 730 and 262-line delay circuit 731, respectively. The output signal of the two-pixel delay circuit 730 is inputted to input terminals of LPF 736 and 739, and to first input terminals of adders 737 and 738 respectively. The output signal of the 262-line delay circuit 731 is inputted to an input terminal of a four-pixel delay circuit 732 and to a second input terminal of the adder 738. The output signal of the four-pixel delay circuit 732 is inputted to a second input terminal of the adder 737. The output signal of the adder 733 is inputted to a first input terminal of an adder 747.
The output signal of the subtracter 734 is inputted to an input terminal of a LPF 740. An output signal of a subtracter 735 is inputted to an input terminal of a LPF 741.
The output of the LPF 736 is inputted to a first input terminal of the signal selecting circuit 746, the output of the adder 737 is inputted to a second input terminal of the signal selecting circuit 746, and the output of the adder 738 is inputted to a third input terminal of a signal selecting circuit 746, respectively.
The output of the LPF 739 is inputted to an input terminal of an absolute value circuit 742, the output of the LPF 740 is inputted to an input terminal of an absolute value circuit 743, and the output of the LPF 741 is inputted to an input terminal of an absolute value circuit 744, respectively.
The output of the absolute value circuit 742 is inputted to a first input terminal of the minimum value selecting circuit 745, the output of the absolute value circuit 743 is inputted to a second input terminal of the minimum value selecting circuit 745, and the output of the absolute value circuit 744 is inputted to a third input terminal of the minimum value selecting circuit 745, respectively.
The output of the minimum value selecting circuit 745 is inputted to a fourth input terminal of the signal selecting circuit 746, thereby selecting and controlling inputs from the first to the third.
The output of the signal selecting circuit 746 is inputted to a second input terminal of the adder 747. The output of the adder 747 is outputted from an output terminal 722 as Y signal 212 by intrafield extracting Y signal in three fields.
Next, explanation will be given of the operation thereof.
In FIG. 11, the points locating in the vicinity of the picked-up sampled point ⊚ in n-1-th field and different 180° in color sub carrier phase from the picked-up sampled point are the sampled points I, II and III. FIG. 34 shows the array of V signal in n-th field and n+1 fields, similarly to FIG. 28.
In FIG. 34, the points locating in the vicinity of the picked-up sampled point ⊚ in n+1-th field and different 180° in color sub carrier phase from the picked-up sampled point are the sampled points IV, V and VI. By calculation between the picked-up sampled point ⊚ and any of these sampled points, interfield Y/C separation is enabled. Moreover, when combining these interfield Y/C separations, Y/C separation in three fields is enabled which is capable of carrying out more accurate Y/C separation.
At first, high frequency component on three-dimensional frequency space including C signal can be taken out according to the difference between the picked-up sampled point ⊚ and the sampled point IV in FIG. 34. In addition, low frequency component on three-dimensional frequency space not including C signal can be taken out according to the sum of the picked-up sampled point ⊚ and the sampled point IV in FIG. 34. The outputs of the subtracter 729 and the adder 733 shown in FIG. 33 respectively show the high frequency component and the low frequency component mentioned above. The output of the subtracter 729 can take out C signal from high frequency component including C signal by the two-pixel delay circuit 730 and LPF 736 compensating for a horizontal position. By adding the above result, and low frequency component on three-dimensional frequency space not including C signal which is the output of the adder 733 by the adder 747, Y signal can be obtained. This is called an extracted Y signal A in three fields.
FIG. 35 shows a three-dimensional frequency space similarly to FIG. 12. The view shows the frequency space in which Y signal exists which has been obtained by extracted Y signal A in three fields.
Secondary, the output of the subtracter 729 shown in FIG. 33 is delayed by 262 lines and four pixels by the 262-line delay circuit 731 and the four-pixel delay circuit 732, and by the adder 737, the sum of the above result and the output of the two-pixel delay circuit 730 can be obtained. The above calculation means that high frequency component in three-dimensional frequency space including C signal can be obtained by the difference between the picked-up sampled point ⊚ and the sampled point IV shown in FIG. 34, and moreover that, C signal can be removed according to the sum of the above-mentioned high frequency components of the positions of the picked-up sampled point ⊚ and the sampled point II shown in FIG. 11. When the same processing as the above is applied, Y signal can be obtained. This is called an extracted Y signal B in three fields.
FIG. 36 also shows frequency space in which Y signal exists obtained by the extracted Y signal B in three fields.
When FIG. 36 is viewed, it seems that the separated Y signal includes a part of C signal, however, it is rare that Y signal includes C signal as the correlation between the Y signal and C signal is strong.
Thirdly, by the adder 738 shown in FIG. 33, the sum of the output of the 262-line delay circuit 731 and that of the two-pixel delay circuit 730 can be obtained. This calculation means that high frequency component in three-dimensional frequency space including C signal can be obtained according to the difference between the picked-up sampled point ⊚ and the sampled point IV shown in FIG. 34, and moreover that, C signal can be removed according to the sum of the above-mentioned high frequency components of the positions of the picked-up sampled point ⊚ and the sampled point III shown in FIG. 11. When the same processing as above-mentioned is applied, Y signal can be obtained. This is called an extracted Y signal C in three fields.
FIG. 37 also shows a frequency space in which Y signal exists obtained by the extracted Y signal C in three fields.
When FIG. 37 is viewed, it seems that the separated Y signal includes a part of C signal, however, it is rare that Y signal includes C signal from the same reason as in the case of FIG. 36.
In order to control selecting adaptively tile filter for extracting Y signal in three fields, it is considered that the correlations between the picked-up sampled point ⊚ and the sampled points IV, V, and VI are detected, respectively.
As it is V signal that is inputted to the input terminal 721, in order to detect correlations, each of the difference is made to pass through LPF to detect correlation of low frequency component of Y signal, and make it as a control signal.
Next, explanation will be given of the operation of the filter for extracting Y signal in three fields having the configuration of FIG. 33. This invention is characterized by using the optimum filter among three kinds of filters for extracting Y signal in three fields including interfield calculation in place of the filter for extracting intrafield Y signal, when the motion detecting unit 80 judges an image to be a motion one.
In FIG. 33, V signal 201 inputted from the input terminal 721 is delayed by 263 lines by the 263-line delay circuit 725.
By subtracting V signal which has been delayed by 263 lines by the 263-line delay circuit 725 from the inputted V signal 201 by the subtracter 729, high frequency component on three-dimensional frequency space including C signal can be obtained.
The output of the subtracter 729 is, at first, capable of removing C signal with the first method by the two-pixel delay circuit 730 and LPF 736. This is the extracted Y signal A in three fields. The output of the subtracter 729 is capable of removing C signal with the second method by being delayed 262 lines by the 262-line delay circuit 731, being delayed by four pixels by the four-pixel delay circuit 732, and by being added to the output of the two-pixel delay circuit 730. This is the extracted Y signal B in three fields mentioned above. The output of the 262-line delay circuit 731 is capable of removing C signal with the third method by being added to the output of the two-pixel delay circuit 730. This is the extracted Y signal C in three fields.
The above-mentioned three kinds of interfield differences are inputted to the signal selecting circuit 746, and are selected by the output of the minimum value selecting circuit 745 to be described later.
The interfield difference being the output of the two-pixel delay circuit 730 is made to pass through the LPF 739 which allows a band lower than 2.1 MHz to be passed is made to be the absolute value thereof by the absolute value circuit 742, and is inputted to the minimum value selecting circuit 745. The absolute value circuit 742 detects the correlation between the picked-up sampled point ⊚ and the sampled point IV shown in FIG. 34.
The output of the one-line delay circuit 726 is subtracted from the output of the two-pixel delay circuit 727 by the subtracter 734 to obtain an interfield difference. The interfield difference being the output of the subtracter 734 is made to pass through LPF 740 which allows band lower than 2.1 MHz to be passed, then made to be the absolute value thereof by the absolute value circuit 734, and inputted to the minimum value selecting circuit 745. The absolute value circuit 734 detects the correlation between the picked-up sampled point ⊚ and the sampled point V shown in FIG. 34.
The output of the four-pixel delay circuit 728 is subtracted from the output of the two-pixel delay circuit 727 to obtain an interfield difference. The interfield difference allows a to pass through LPF 741 which makes band lower than 2.1 MHz to be passed, then made to be the absolute value thereof by the absolute value circuit 744, and inputted to the minimum value selecting circuit 745. The absolute value circuit 744 detects the correlation between the picked-up sampled point ⊚ and the sampled point VI shown in FIG. 34.
The minimum value selecting circuit 745 selects the minimum output (whose amount of detected correlation is maximum) of the above mentioned three kinds of absolute value outputs and controls the signal selecting circuit 746.
That is to say, the signal selecting circuit 746 selects the output of the LPF 736 in the case where the output of the absolute value circuit 742 is minimum, selects the output of the adder 737 in the case where the output of the absolute value circuit 743 is minimum, and selects the output of the adder 738 in the case where the output of the absolute value 744 is minimum.
In addition, the output of the signal selecting circuit 746 is capable of removing C signal in the direction in which correlation has been detected in three dimensional frequency space and of obtaining Y signal 212 by extracting Y signal in three fields.
FIG. 38 is a detailed block diagram of a second embodiment of the filter 76 for extracting Y signal in three fields.
The only difference between the ones shown in FIG. 38 and FIG. 33 is the method for detecting interfield correlation.
Explanation will be given only of an interfield correlation detecting circuit different from that in FIG. 33, among filters for extracting Y signal in three fields having the configuration shown in FIG. 38. Same numeral are used on the same portions shown in FIG. 33.
In this embodiment, as a method for detecting correlation of V signal, a method for detecting a direction in which spectrum of Y signal extends in three-dimensional frequency space.
The frequency band, which detects spectrum extension of Y signal for selecting and controlling three kinds of interfield extracting Y signal are shown in FIG. 39, FIG. 40 and FIG. 41.
FIG. 39 is a frequency band which detects spectrum extension of Y signal for selecting the interfield extracted Y signal A. By making the difference between the picked-up sampled point ⊚ and sampled point ◯ VII located one line up the sampled point IV shown in FIG. 34 pass through LPF, this band can be detected.
FIG. 40 is a frequency band which detects spectrum extension of Y signal for selecting the extracted interfield Y signal B. By making the sum of the picked-up sampled point ⊚ and sampled point V shown in FIG. 34 to pass through BPF, this band can be detected.
FIG. 41 is a frequency band which detects spectrum extension of Y signal for selecting the extracted interfield Y signal C. By making the sum of the picked-up sampled point ⊚ and sampled point VI in FIG. 34 pass through BPF, this band can be detected.
Next, explanation will be given only of an interfield correlation detecting circuit different from that shown in FIG. 33, among filters for extracting Y signal in three fields having the configuration shown in FIG. 38. In FIG. 38, same numerals are used on the same portions as shown in FIG. 33.
An output of a two-pixel delay circuit 748 is subtracted from that of the two pixel delay circuit 727 by a subtracter 749, and the above result is made to pass through a LPF which allows a band lower than 2.1 MHz to be passed, then is made to be the absolute value thereof by an absolute value circuit 755, and inputted to a maximum value selecting circuit 758 to detect the correlation between the picked-up sampled point ⊚ and sampled point, ◯ VII shown in FIG. 34.
The output of the one-line delay circuit 726 and that of the two-pixel delay circuit 727 is added by an adder 750, and the above result is made to pass through a BPF 753 which allows a band higher than 2.1 MHz to be passed, then made to be the absolute value thereof by an absolute value circuit 758, and inputted to the maximum value selecting circuit 758 to detect correlation between the picked-up sampled point ⊚ and sampled point V shown in FIG. 34.
The output of the four-pixel delay circuit 728 and that of the two-pixel delay circuit 727 are added by an adder 751, and the above result is made to pass through a BPF 754 which allows a band higher than 2.1 MHz to be passed, then made to be the absolute value thereof by an absolute value circuit 757, and inputted to the maximum selecting circuit 758 to detect the correlation between the picked-up sampled point ⊚ and sampled point VI shown in FIG. 34.
The maximum value selecting circuit 758 selects the maximum output (whose amount of detected correlation is also maximum) among the above-mentioned three kinds of the absolute values, thereby controlling the signal selecting circuit 746.
FIG. 42 is a detailed block diagram of a third embodiment of the filter 76 for extracting Y signal in three fields shown in FIG. 32.
In FIG. 42, the difference between the one shown in FIG. 33 is that the optimum filter is used among four kinds of filters including a filter for extracting intrafield Y signal as well as three kinds of filters for extracting Y signal in three fields. Explanation will be given only of an interfield correlation detecting circuit different from that shown in FIG. 33, among filters for extracting Y signal in three fields. In FIG. 42, same numerals are used on the same portions as shown in FIG. 33.
The output of the 263-line delay circuit 725 is inputted to the input terminal of the two-pixel delay circuit 727 and to second input terminals of the subtracter 729 and the adder 733 as well as to a filter 760 for extracting intrafield Y signal. The output of the filter 760 for extracting intrafield Y signal is inputted to a first input terminal of the second signal selecting circuit 761. The output of the adder 747 is inputted to a second input terminal of the second signal selecting circuit 761. The second signal selecting circuit 761 selects either of the first or second input signal by an output of a threshold judging circuit 759 to be described later.
The outputs of the LPF 739, 740 and 741 are respectively inputted to the absolute value circuit 742, 743 and 744, similarly to the case of FIG. 33. The output of the absolute value circuit 742 is inputted to first input terminals of the maximum value selecting circuit 758 and the minimum value selecting circuit 745 respectively to detect the correlation between the picked-up sampled point ⊚ and sampled point IV. The output of the absolute value circuit 743 is inputted to second input terminals of the maximum value selecting circuit 758 and the minimum value selecting circuit 745 respectively, to detect correlation between the picked-up sampled point ⊚ and sampled point V. The output of the absolute value circuit 744 is inputted to third input terminals of the maximum value selecting circuit 758 and the minimum value selecting circuit 745 respectively to detect the correlation between the picked-up sampled point ⊚ and sampled point VI shown in FIG. 34. The output of the maximum value selecting circuit 758 is inputted to a first input terminal of threshold judging circuit 759. The output of the minimum value selecting circuit 745 is inputted to a second input terminal of the threshold judging circuit 759 and to a fourth input terminal of the first signal selecting circuit 746 respectively. The outpost of the threshold judging circuit 759 is inputted to a third input terminal of the second signal selecting circuit 761. The threshold judging circuit 759 controls the second signal selecting circuit 761 to select the output of the filter 760 for extracting intrafield Y signal in either the case where the maximum value of values of three kinds of interfield correlation of is smaller than the first threshold α or the minimum value of values of three kinds of interfield correlations is larger than the second threshold β.
On the other hand, by the threshold judging circuit 759, in either the case where the maximum value of values of three kinds of interfield correlations is judged to be larger than the first threshold α or the minimum value of values of three kinds of interfield correlations is judged to be smaller than the second threshold value β, according to the output of the minimum value selecting circuit 745, the first signal selecting circuit 746 is controlled to select the output of the LPF 736 in the case where the output of the absolute value circuit 742 is minimum, selects the output of the adder 737 in the case where the output of the absolute value circuit 743 is minimum, and selects the output of the adder 738 in the case where the output of the absolute value circuit 744 is minimum, respectively, and moreover, the second signal selecting circuit 761 is controlled to select an output of a filter for extracting Y signal in three fields being the output of an adder 747. Here, there is a relationship α<β.
The output of the second signal selecting circuit 761 is outputted from the output terminal 722 as the Y signal 212 extracted in three fields.
FIG. 43 is a detailed block diagram of a fourth embodiment of the filter 76 for extracting Y signal in three fields.
In FIG. 43, the only difference from the one shown in FIG. 33 is the method for detecting interframe correlation by calculation. Now explanation will be given only of the different points from the one shown in FIG. 33, among filters for extracting Y signal in three fields having the configuration of FIG. 43. In FIG. 43, same numerals are used on the same portions as shown in FIG. 33.
The configuration and operation of the filter A for extracting Y signal in three fields are same as the filter shown in FIG. 33.
Next, explanation will be given of the operation of the filter B for extracting Y signal in three fields.
The output of the two-pixel delay circuit 730 is the difference between the picked-up sampled point ⊚ and the sampled point i IV, as mentioned above. In addition, a subtracter 764 obtains a difference between the output of the 262-line delay circuit 725 which makes V signal to be delayed by 262 lines and the signal outputted from the one-line delay circuit 726 which makes the output of the delay circuit 725 to be delayed by one line then outputted from the 262 line delay circuit 731 which makes the output of the delay circuit 726 to be delayed by 262 lines. The signal of the subtracter 764 is equal to a signal obtained by delaying the output of the subtracter 729 by 262 lines.
By adding by the adder 737 the output of the two-pixel delay circuit 730 to that obtained by delaying that of the subtracter 764 by four pixels by the four-pixel delay circuit 732, same output as the filter B for extracting Y signal in three fields can be obtained.
Moreover, explanation will be given of the operation of the filter C for extracting Y signal in three fields. The output of the two pixel delay circuit 730 is the difference between the picked-up sampled point ⊚ and sampled point IV. By adding the output of the two-pixel delay circuit 730 and that of the subtracter 764 by the adder 738, an output equal to that of the filter C for extracting Y signal in three fields can be obtained.
Next, explanation will be given of detecting of interframe correlation.
An output of a two-pixel delay circuit 766 is a signal of the sampled pointI shown in FIG. 11, and the output of the two-pixel delay circuit 748 is a signal of the sampled point IV shown in FIG. 34. A subtracter obtains a difference between the outputs of the two-pixel delay circuit 766 and 748, and the difference is made to be the absolute value thereof by the absolute value circuit 742, thereby interframe correlation A with the picked-up sampled point ⊚ as the center can be obtained.
The output of a four-pixel delay circuit 770 is a signal of the sampled point II shown in FIG. 11, and the output of the one-line delay circuit 726 is a signal of the sampled point V shown in FIG. 34. The subtracter 772 obtains a difference between the outputs of the one-line delay circuit 726 and the four-pixel delay circuit 770, then the difference is made to be the absolute value thereof by the absolute value circuit 743, thereby interframe correlation B with the picked-up sampled point ⊚ as the center can be obtained.
The output of the 262-line delay circuit 731 is a signal of the sampled point III shown in FIG. 11, and the output of the four-pixel delay circuit 728 is a signal of the sampled point VI shown in FIG. 34. A subtracter 773 obtains a difference between the outputs of the 262-line delay circuit 731 and the four-pixel delay circuit 728, then the difference is made to be the absolute value thereof by the absolute value circuit 744, thereby interframe correlation C with the picked-up sampled point ⊚ as the center can be obtained.
The minimum value selecting circuit 745 selects the minimum output (whose amount of detected correlation is maximum) among the above mentioned three kinds of outputs of the absolute value circuits, thereby controlling the signal selecting circuit 746.
That is to say, the signal selecting circuit 746 selects the output of the LPF 736 in the case where the output of the absolute value circuit 742 is minimum, selects the output of the adder 737 in the case where the output of the absolute value circuit 743 is minimum, and selects the output of the adder 738 in the case where the output of the absolute value circuit is minimum, respectively.
The output of the signal selecting circuit 746 is added to that of the adder 733 by the adder 747, and is outputted from the output terminal 722 as an extracted Y signal in three fields.
FIG. 44 is a detailed block diagram of one embodiment of the filter 17 for extracting intraframe C signal.
The filter for extracting intraframe C signal having the configuration of FIG. 44, is characterized by using the optimum filter among three kinds of filters for extracting intraframe C signal including interfield calculation in place of the filter for extracting intrafield C signal as the motion image processing when the motion detecting unit 80 judges an image to be a motion one.
In FIG. 44, the color difference signal 204 inputted from the input terminal 723 is delayed by 263 lines by a 263-line delay circuit 788. The output of the 263-line delay circuit 788 is delayed by two pixels by the two-pixel delay circuit 774, and is delayed by 262 lines by a 262-line delay circuit 775. The output, of the 262-line delay circuit 775 is inputted to a second input of a subtracter 779 and to input terminals of the four-pixel delay circuit 777 and one-line delay circuit 776.
By subtracting a color difference signal which has been delayed by two pixel by a two-pixel delay circuit 774 from the output of the 262-line delay circuit 775 by the subtracter 779, an interfield difference for the extracted interfield C signal C can be obtained.
By subtracting the color difference signal which has been delayed by two pixels by the two-pixel delay circuit 774 from the output of the four-pixel delay circuit 777 by a subtracter 769, an interfield difference for the extracted interfield C signal B can be obtained.
By subtracting the color difference signal which has been delayed by two pixels by the two-pixel delay circuit 774 from an output of a two-pixel delay circuit 778 by a subtracter 781, an interfield difference for the extracted interfield C signal A can be obtained.
Above-mentioned three kinds of interfield differences are inputted to a signal selecting circuit 786 and selected by an output of a minimum value selecting circuit 785 to be described later.
The interfield difference which is the output of the subtracter 779 is made to be the absolute value thereof by an absolute value circuit 782 and inputted to the minimum value selecting circuit 785. The absolute value circuit 782 detects the correlation of the color difference signal between the picked-up sampled point ⊚ and the sampled point III shown in FIG. 11.
The interfield difference which is the output of the subtracter 769 is made to be the absolute value thereof by an absolute value circuit 783 and inputted to the minimum value selecting circuit 785. The absolute value circuit 783 detects the correlation of the color difference signal between the picked-up sampled point ⊚ and the sampled point II shown in FIG. 11.
The interfield difference which is the output of the subtracter 781 is made to be the absolute value thereof by the absolute value circuit 784 and inputted to the minimum value selecting circuit 785. The absolute value circuit 784 detects the correlation of the color difference signal of the picked-up sampled point ⊚ and the sampled point I shown in FIG. 11 .
The minimum value selecting circuit 785 selects the minimum output (whose amount of detected correlation is maximum) among the above-mentioned three kinds of absolute value outputs, thereby controlling the signal selecting circuit 786.
That is to say, the signal selecting circuit 786 selects the output of the subtracter 779 in the case where the output of the absolute value circuit 782 is minimum, selects the output of the subtracter 769 in the case where the output of the absolute value circuit 783 is minimum, and selects the output of the subtracter 781 in the case where the output of the absolute value circuit 784 is minimum, respectively.
Moreover, the output of the signal selecting circuit 786 is subtracted from the color difference signal by a subtracter 787, thereby low frequency component of three-dimensional frequency space in the direction in which correlation has been detected can be obtained.
In addition, in FIG. 33, 38 and 42, the interfield correlation detecting circuit is constructed so as to detect the correlation between the sampled points IV, V and VI in n+1-th field and the picked-up sampled point ⊚ shown in FIG. 34, however, it is possible to detect the correlation between the sampled point I, II and III in n-1-th field and the picked-up sampled point ⊚ in n-th field.
In addition, similarly to the case of FIG. 42 wherein a filter is selected from four kinds of filters including three kinds of filters for extracting Y signal in three fields with a filter for extracting intrafield Y signal juxtaposed, it is also possible in the case of FIG. 38 to select a filter from four kinds of filters including three kinds of intraframe Y signal with a filter for extracting intrafield Y signal juxtaposed. In the same way, also in the case of FIG. 43, it is possible to select a filter from four kinds of filters including three kinds of filters for extracting intraframe Y signal with a filter for extracting intrafield Y signal juxtaposed. In the same way, also in the case of FIG. 44, it is possible to select a filter from four kinds of filters including three kinds of filters for extracting intraframe C signal with a filter for extracting intrafield C signal juxtaposed.
In addition, similarly to the case of FIG. 43 wherein interframe correlation is detected and thereby selecting three kinds of filters for extracting Y signal in three fields, it is also possible in the case of FIG. 44 to detect interframe correlation, thereby selecting three kinds of filters for extracting intraframe C signal. Moreover in the case of FIG. 44, it is also possible to select a filter from four kinds of filters including three kinds of filters for extracting intraframe C signal, by detecting interframe correlation as mentioned above and with a filter for extracting intrafield C signal juxtaposed.
In addition, in FIG. 32, a circuit for the motion adaptive processing of the color signal comprising of the filter 17 for extracting intraframe C signal, the filter 10 for extracting interframe C signal and the chrominance signal mixing circuit 15 makes the two kinds of time-divisionally multiplexed color difference signal 204 as its input signal, however, it is also possible to juxtapose further the same configuration of the filter 17 for extracting intraframe C signal, the filter 10 for extracting interframe C signal, and the chrominance signal mixing circuit 15, thereby to construct two kinds of color difference signals to motion adaptably process independently from each other.
As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims. | A filter for motion adaptive Y/C separation, which is capable of obtaining image of high resolution and little picture quality degradation in the case where an image is switched from static one to motion one or vice-versa, is provided with a filter for extracting Y signal outputting Y signal and a filter for extracting C signal outputting C signal, by detecting whether image is motion one or static one by a motion detecting unit, and when motion image is detected, by detecting partially interframe correlation or correlation in three fields, and according to the detection result, by adaptively switching a plurality of processings for extracting intraframe Y signal and a plurality of processings for extracting intraframe C signal. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This continuation patent application claims priority to application Ser. No. 11/438,237, filed May 22, 2006, which claims priority to the provisional patent application having Ser. No. 60/683,979, filed May 25, 2005.
BACKGROUND OF THE INVENTION
[0002] This fragrance slurry pad relates to sampling devices and more specifically to a pad bearing a printed fragrance sample. A unique aspect of the present pad is a fragrance sample printed in a logo, symbol, word, or mark selected by the manufacturer of the sample.
[0003] Microencapsulated fragrances have been used for decades for the purpose of sampling fragrances in both Scratch & Sniff applications and in fragrance strip applications, commonly called TruEssence® fragrance strip or Scent Strip®. The first identified strip is available from the assignee of the invention herein, Orlandi, Inc., from Farmingdale, N.Y. First, Scratch & Sniff products generally involve the application of a microencapsulated fragrance “slurry” on the surface of a coated or uncoated text or cover stock weight paper, drying the slurry by means of heated forced air, or air drying, and allowing a consumer to subsequently liberate the fragrance by scratching and breaking the capsules. Second, fragrance strip products generally involve the application of microencapsulated slurry in the folded area of a coated text weight paper, allowing the slurry to dry and adhere to the inside surfaces of the folded paper area by means of absorption and evaporation of slurry carrier material. The capsules break and liberate the fragrance upon opening the fold area of the paper. Micro-encapsulation has been well documented in the chemistry and printing literature. The carrier systems for the encapsulated fragrances are predominantly hydrous but synthetic capsules in anhydrous, solvent based systems using such materials as urea-formaldehyde, are also common in the industry.
[0004] The above mentioned fragrance sampling products can be manufactured on lithographic, flexographic or rotogravure printing machines, both in sheet or roll form, using silkscreen, flexography, extrusion and airless spray technology among other methods to apply the fragrance slurry. Manufacturers of fragrance strips have predominantly used flexographic printing technology to apply the slurry during heat-set, off-set (lithographic) web printing. Flexography involves raised printing, where the slurry is transferred from the raised surface contour of a printing plate or pad to paper stock. Plates and pads are generally made using photo-polymer technology, by etching non transfer areas away from a soft material such as rubber using mechanical, laser and other technology, die molding, casting, extruding and forming liquid, heated or resinous materials.
[0005] Initially, fragrance strip manufacturers used pads that were made to apply adhesives in the web printing industry. Over the years, very few design changes addressed functional needs of individual fragrance slurries or manufacturing problems. Prior art slurry application pad designs involve repeated patterns of diamonds, circles, hash patterns, or lines, as shown in FIG. 1 .
[0006] Fragrance strips have become the predominant product used for fragrance sampling in the United States, with estimates ranging between 2.5 to 3.5 billion units annually. Fragrance strips appear in a variety of common print formats including periodical and national magazine inserts, direct mail, catalog blow-in and stitch-in inserts, billing statement enclosures, mail order envelopes and business response envelopes, and billing statement remittance envelopes. Consumers and readers generally appreciate and enjoy receiving free fragrance samples but, the competing fragrance marketing messages have become almost overwhelming. Often more than three fragrance strips are included in mail such as subscription magazines, catalogs, direct mail, and store and credit card billing statements.
[0007] The present art overcomes the limitations of the prior art. That is, in the art of the present invention, a fragrance slurry pad receives a portion of slurry upon a pad that impresses a mark, logo, or word, or marketing message upon a sampling strip.
[0008] The difficulty in providing a fragrance slurry pad is shown by the operation of a typical fragrance strip. Fragrance marketers sought for years to find new ways of sampling fragrances to differentiate their advertising message in the plethora of competing advertising. Partially in response to this need, fragrance sampling companies developed scented pressure sensitive labels marketed under such trade names such as Scent Seals®, Liquatouch®, and Discover® with the intent of incorporating them in lieu of a fragrance strip as part of the above mentioned print formats. These new label products proved ineffective and cost prohibitive and thus went abandoned in large print advertising programs.
[0009] The present invention overcomes the difficulties of the prior art. The fragrance slurry pad has a mark, word, or logo etched into a flexographic print pad. The mark, word, or logo differentiates slurry pads among the many fragrances currently upon the market. Combined with other sampling components, the fragrance slurry pad readily integrates into existing sampling programs.
SUMMARY OF THE INVENTION
[0010] The fragrance slurry pad is a pad and method that accepts a slurry printed into a recognizable mark, logo, brand, or word, or marketing message. The present invention enhances the marketing potential and impact of fragrance strip advertising and better differentiates among marketers without any significant increase in cost. The present invention creates fragrance slurry deposition pads that support and reinforce a marketing message by having a brand name, logo, or message etched into a flexographic print pad, thus rendering the fragrance slurry in a discernible pattern upon a sampling strip and visible once the flap is opened.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIGS. 1 a , 1 b , 1 c , 1 d , 1 e, and 1 f show a plan view of the prior art strips and various treatments to the surface of the strips;
[0012] FIGS. 2 a , 2 b , 2 c , 2 d , and 2 e show a plan view of the present invention bearing various marks and logos upon the surface of strips in accordance with the present invention; and,
[0013] FIG. 3 is an isometric view of the method and apparatus for transferring the fragrance slurry to the continuous web of paper as it passes the transfer roller. The same reference numerals refer to the same parts throughout the various figures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] The present art overcomes the prior art limitations by use of a fragrance slurry instead of ink to be transformed from a flexographic pad to paper. Turning to FIG. 1 , the prior art of fragrance strips is shown. The prior art strips bear a variety of geometric patterns applied to the surface of the strip. The geometric patterns include diagonals 1 a , longitudinal lines 1 b, dots 1 c , diamonds 1 d, and a grid 1 e. The prior art patterns are applied in the same way as the current invention. A pick-up cylinder turning in a pan filled with slurry is coated by said slurry and transfers the slurry to a pad which is mounted on a transfer cylinder. The raised pad on this transfer cylinder now carries slurry and transfers the slurry by contacting a passing web of paper. The amount of slurry transferred to the paper is controlled by web tension, pressure between the web and the pad, and the speed of rotation of the pick-up cylinder on the slurry pan.
[0015] Prior art patterns on pads were driven entirely by the need to allow a variety of materials to be trapped in the contoured areas of the pad and transferred on paper. Originally, these pads were designed to apply adhesives. Beginning in the late 1970's, when flexographic technology was used to apply fragrance slurry during the web heat-set offset printing process, fragrance slurries were being applied by these pads. Slurries vary in viscosity and consistency due to the differences in fragrance oil formulations that need to be microencapsulated. In order to control and regulate the amount of slurry that could be transferred to the paper, printing companies and pad manufacturers started experimenting and modifying pad patterns.
[0016] The flexographic printing prior art is replete with different methods and technologies of creating images on print pads that transfer ink to a substrate. The point of this invention is to use colored or uncolored microencapsulated fragrance material instead of ink to print a fragranced message or image on a paper substrate.
[0017] This invention applies to other cosmetic or fragrance materials as well.
[0018] The print application of the cosmetic or fragrance material can be done with a flexographic pad in the raised area. It can also be applied in a silkscreen printing process.
[0019] The point is: using segmented or non segmented cosmetic and fragrance materials instead of ink to print a marketing message.
[0020] Many existing methods and devices place an image on paper, using ink or a die. The existing methods and devices include raised printing or flexography, offset, recessed printing or gravure, silkscreen printing or serigraphy, ink jet imaging where electrically charged pigment particles create an image in an electrostatic field, airless spraying, or air brushing often with a mask to prevent overspray. An image can also be formed by foil stamping, embossing, die-casting, and using thermoforming, vacuum forming, casting, heat treatment, electrostatic treatment, spraying, extruding, adhesives, and cohesives as methods to adhere ink or pigmented particles to a substrate in a pattern. Inks are either traditionally formulated as, offset inks, flexo inks, ultraviolet cured inks, and thermographic inks. And some printing systems require treatment ovens, or UV light to set or cure the inks or substrates. In the present invention, the inks adhere to the surface a paper substrate having a recognizable form such as a mark, word, or logo. All printing currently involves only inks, whereas, imaging a flex-o-pad in the manner as described herein, to carry a pigmented or non pigmented fragrance, in a fragrance slurry, is a new concept, and it is used in the current invention, in Scent Strip Manufacturing, to apply such through the use of a transfer pad with a discernable message.
[0021] In the preferred embodiment, the present invention utilizes flexographic technology and more particularly, a laser to etch away non-image areas of a print pad. The image area of the print pad contains a pattern of a mark, word, or logo here shown repeated for the length of one or more print strips as shown in FIG. 2 . Outside of the image area, the remainder area may still exhibit traditional diamond, circle, line or diagonal patterns that have effectively picked up and transferred fragrance slurry to paper in a web heat set and offset, or lithographic, printing process. In the preferred embodiment, the print pad is made of rubber. In alternate embodiment, the print pad is made of suitable ductile material.
[0022] The present invention also provides a method. Following graphic design, the present invention etches an image area into a print pad and leaves a remainder area. The image area contains the graphic design in the form of a marketing message using a mark, logo, or word. The present invention then applies a micro-encapsulated fragrance slurry to the print pad mounted in flexographic equipment. The print pad then deposits the fragrance slurry upon a paper substrate thus transferring the marketing message of the image area.
[0023] FIG. 3 shows the system and method for transferring the fragrance slurry from its pickup roller, through the transfer roller, and to the continuous web of paper. For example, the slurry tray 1 has a supply of the fragrance slurry provided therein, and a pickup roller 2 partially locates within the slurry, within the tray, to do just that, pickup a supply of the fragrance slurry for further transfer. It is then applied from the pickup roller to the transfer roller 3 , and then the transfer roller passes the slurry to the flexographic print roller, at its various printing pad areas, as at 4 . Then, the pattern, upon the print pad or roller, is transferred to the continuous web of paper, as at 5 , as it passes the flexographic print roller. Thus, the paper is then printed with the fragrance slurry, can be dried, reconfigured into a roll form, transferred to a customer, where it may be cut into various sheets, or cards, for use for commercial purposes. The transfer roller contacts with the pads that are mounted on the flexographic print cylinder, and these pads contact the paper, to transfer the fragrance slurry thereto, into whatever discernable pattern is applied to the cylinder, such as the example of patterns as shown in FIGS. 1 and 2 .
[0024] From the aforementioned description, a fragrance slurry pad has been described. The fragrance slurry pad is uniquely capable of applying a mark, word, or logo upon a fragrance strip. The fragrance slurry pad and its various components may be manufactured from many materials, including but not limited to single or in combination, rubber, polymers, polyester, polyethylene, polypropylene, polyvinyl chloride, nylon, Teslin, Saran, open cell foam, closed cell foam, ferrous and non-ferrous metal foils and their alloys, and composites. | The fragrance slurry pad receives a fragrance in slurry and prints the slurry into a recognizable logo, brand, or word upon a strip. To enhance the marketing impact of fragrance strip advertising and to differentiate among marketers without increase in cost, the present invention is fragrance slurry deposition pads that support and reinforce a marketing message. The preferred embodiment has a brand name, logo, or message etched into a flexographic print pad. The print pad applies the slurry to a strip located beneath a flap. Upon opening the flap, the fragrance slurry appears in a discernible pattern and visible message. | 3 |
This invention relates in general to a demolder, and more particularly to a demolder for and a method of separating and removing mold material formed around the joint of the rail ends of longitudinally adjacent railroad rails during the use of a thermite weld system to join the rails into a continuous rail.
BACKGROUND OF THE INVENTION
Heretofore, it has been well known in the railroad industry to eliminate rail joints by using a thermite weld system or weld to weld together two rail ends to form a smooth, continuous, and uninterrupted railroad rail. The thermite weld system is generally made by mounting a mold structure around the joint area of the two rail ends with an entry or gate on top for receiving molten weld material. The use of the thermite weld system is quite old and widespread in the railroad industry, and the system is time-consuming, labor-intensive, and hazardous to workers.
More specifically, to join two rail ends using the thermite weld system, the rails are laid and carefully aligned, leaving a small space between the ends. After alignment and leveling of the rail ends, the thermite weld system, which may include a three-piece mold preformed from a suitable refractory, such as bentonite and sand, is attached to the rail ends. One mold piece underlies both rail ends and two pieces extend upwardly from the lower piece on opposite sides of the rail ends. These mold pieces are securely clamped together and to the rails and extend over the top of the rails, leaving a gate at the top for the molten metal weld material to enter the mold. The mold may be arranged with upwardly extending risers coming off the shoe of the rails to allow trapped air and gases to escape when the molten metal weld material flows into the mold. A suitable material may be used to eliminate any spaces or gaps between the mold pieces and the rail surfaces.
As part of the welding process, the rail ends and surrounding portions of the rails are preheated by use of a propane torch or other suitable means to a red-hot condition of approximately 1800° F. prior to pouring the molten weld material into the mold.
A crucible filled with a suitable powdered metal mixture is placed over the mold. The powdered metal mixture is ignited to transform the mixture into molten metal at approximately 4000° to 5000° F. The molten metal is then poured through the gate into the mold to fill the space between the rail ends and make the weld joint between the rail sections.
After waiting approximately five minutes, the weld joint has cooled enough to remove the malleable mold material from around the joint. However, the mold material remains dangerously hot. The crucible is removed, and then the clamps holding the mold material are carefully removed, leaving the hot mold material on the rails.
Heretofore, removing this mold material required two people. The first person would hold a shovel on the rail at one side of the mold, while the second person would slowly break off parts of the mold material with a sledge hammer. As the material was broken by the person handling the sledge, the material was caught in the shovel by the person handling the shovel. The use of the sledge hammer is dangerous because it can cause sparks to shoot out from the mold material and may further cause pieces of hot mold material to fly off of the rails. The person with the shovel then would carry the mold material which was still dangerously hot to a location where the ground was dry. If the broken mold material was accidentally dropped or placed in water or even in a wet location, a dangerous reaction or explosion could occur, and which in the past has caused severe injury. This dangerous process would be repeated until sufficient amounts of the mold material on the top of the rail, as well as on both sides of the rail, were removed.
A hydraulic shear would then be placed on the top of the rails to shear off the sprue left during the molding process. A grinder would next be used to smooth the weld at the ball of the rail. Although it was not necessary to remove the lower part of the mold material, some railroads would do so for the purpose of making the rail look neater. Any mold material left on the rail would eventually disintegrate in the weather.
SUMMARY OF THE INVENTION
The present invention overcomes the above problems in providing a demolder for safely separating and removing the mold material from the rail ends by one person after the clamps are removed and for safely carrying the separated mold material away from the rails to a dry location. The demolder of the present invention is in the form of a box having an open lower end and a handle extending upwardly from the box. On opposite sides of the box, substantially aligned slots are provided to allow the box to fit over about two-thirds of the rail.
In practice, once the clamps are removed from the mold material, a single person or operator positions the demolder of the present invention over the mold material and the rail. The operator then rocks the demolder along the longitudinal axis of the rail to loosen and separate the mold. Once the mold material is separated from the rails, the demolder is longitudinally lowered to a position substantially parallel to the rails while maintaining the separated mold material therein. The demolder is then lifted away from the rail with the separated mold material in its box and is carried to a dry location where the box of the demolder is emptied of mold material.
It is therefore an object of the present invention to provide a demolder for safely separating and removing the mold material formed around the joint of two adjacent railroad rail ends during a thermite welding process.
Another object of the present invention is provide a method in which one person or operator can separate and remove a substantial portion of the mold material around the joint of the rail ends, thereby eliminating the need for two people to demold the joint.
A still further object of the present invention is to increase safety by better containment of the hot mold material as it is separated and carried away from the joint.
A still further object of the present invention is to decrease the time necessary to remove the mold material from the joint of two rails and thereby increase the efficiency of the thermite weld system.
Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheet of drawings, wherein like reference numerals refer to like parts.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the demolder of the invention;
FIG. 2 is an elevational view of the back wall of the demolder;
FIG. 3 is a bottom plan view of the demolder;
FIG. 4 is an elevational view of the demolder like FIG. 2 and illustrating the demolder in mounted position on a rail over a mold for a thermite weld system;
FIG. 5 is a transverse cross-sectional view of the demolder over the mold material on a rail joint for a thermite weld system illustrating the general construction of the mold and taken substantially through line 5--5 of FIG. 7;
FIG. 6 is a longitudinal cross-sectional view through the demolder, mold material, and ball portion of the rail taken substantially through line 6--6 of FIG. 5;
FIG. 7 is a perspective view of a person holding the demolder vertically on a mold with the front of the demolder facing the person;
FIG. 8 is a perspective view of a person pushing or rocking the demolder away from his body as part of a rocking action;
FIG. 9 is a perspective view of a person pulling the demolder toward his body as part of a rocking action; and
FIG. 10 is a perspective view of a person carrying the demolder, front wall down, horizontally with broken away mold material.
DESCRIPTION OF THE INVENTION
Referring now to the drawings, and particularly to FIGS. 1 to 3, the demolder 20 of the present invention includes an open- ended steel box or casing 22 and a handle 24 extending from the box 22. The box 22 consists of a front wall 26, a back wall 28, opposed side walls 30 and 32 and a top cover or wall 34. The spaced-apart front and back walls and the spaced-apart side walls define upper and lower ends respectively. The top cover 34 is connected to the front, back, and side walls and closes the upper end of the box 22. The lower end remains open. It is preferred that the front, back, and side walls as well as the top cover are welded together; however, it should be appreciated that the walls and cover could be connected by other means. They are closed so as to contain the mold material during a demolding operation.
Aligned slots or cutouts 40 and 42 are formed in the front and back walls. These slots extend from the lower opening toward the top cover 34 and are centrally located in the front and back walls. The height of the slots is approximately two-thirds the height of the railroad rail and slightly wider than the rail such that the rail may be freely received in the slots.
The handle 24 is T-shaped and includes an elongated bar 44 and a gripping crossbar 46. Preferably, the bars are tubular steel. The bar 44 is attached to and extends upwardly from the back wall 28 and the crossbar 46 is perpendicularly attached to the bar 44 to allow a person to grip on both sides of the bar 44. The handle is used to manipulate and carry the box 22. It should be appreciated that the handle could be attached to the front wall, side walls, or the top cover if desired, and the structure of the handle may take other forms. Preferably, the handle is attached to the back wall 28 of the box 22 and centered between the opposed edges of the back wall.
A rough illustration of part of the thermite weld system is shown in FIGS. 4 to 7, it being understood the crucible and mold clamps have been removed. Two longitudinally adjacent railroad rails 50 and 52 which are mounted on the tie plates 53 and respectively secured to the railroad ties 54 and 56 by spikes 58. The adjacent rail ends form a gap that is shown filled by molten metal to form a thermite weld 66 which welds the ends of the rails together. Surrounding the joint is mold material 70 made of a suitable refractory, such as bentonite and sand, which is formed from a bottom mold piece 72 and two side mold pieces 74 and 76. The bottom mold piece 72 underlies both rail ends and the side mold pieces 74 and 76 extend upwardly from the bottom mold piece on opposite sides of the joint. The mold material 70 shown in FIGS. 4 to 7 as well as FIGS. 8 to 10 is for illustration purposes only, as the size, shape, and structure of the mold material can vary. For example, a two-piece mold may be used. The mold material may also be arranged with upwardly extending risers (not shown) coming off the rails to allow trapped air or gases to escape when the molten metal flows through the gate 78 and into the mold formed at the joint.
As seen in FIGS. 4 to 8, the demolder 20, and specifically the lower end of the box 22, is shown positioned over and encasing a substantial part of the malleable and hot mold material 70. The slots 40 and 42 of the box fit over the rails 50 and 52, respectively, and extend down over approximately two-thirds of the rails. Likewise, the front, back, and side walls of the demolder extend down over approximately two-thirds of the mold material of the mold.
Referring now to FIGS. 7 to 10, the method of separating and removing the mold material 70 from the joint of the rails 50 and 52 with a demolder 20 of the present invention is illustrated. A single person or operator 80 positions the demolder 22, and specifically the box 22, over the mold material after the clamps (not shown) for clamping the mold parts together and to the rails are removed. The operator initially grips the crossbar 46 of the handle 24 to rock the demolder towards him and away from him longitudinally along the rails until portions of the mold material 70 separate from the rails. This method essentially eliminates the danger from sparks shooting out from contact between the sledge hammer and the mold material. Also eliminated is the possibility of danger from flying pieces of hot mold material heretofore caused by using the sledge hammer to remove the mold.
Once the mold material 70 is separated from the rails by the rocking action of the demolder, the operator lowers the demolder toward the rail 52 to load the mold material into the casing 22. It should be appreciated that since the handle is placed on the back of the demolder, when the operator lowers the demolder toward him and to a substantially horizontal position, the handle 24 of the demolder will not contact the rail 52, thereby allowing the operator to easily pick up the demolder by grasping the bar 44. The operator then lifts the demolder with the separated mold material from the weld joint and carries the demolder with the separated mold material to a dry location, where the separated mold material is emptied from the casing. While the handle is positioned on the upper side of the box when carrying mold material, it may be appreciated that the handle could be on the bottom side if desired. It should be appreciated that if the mold material is placed in water or a wet location which triggers a reaction or explosion, the casing of the demolder can shield the operator from injury.
In addition to greatly enhancing the safety of the operator during the demolding process, the demolder and the method of using the demolder eliminate the need for two people to demold the mold material. One person or operator can handle the demolder to break off and scoop up a major portion of the mold material and carry it to a disposal area. Thus, the demolder efficiently and safely increases the speed of the entire welding process, enhances worker safety, and decreases labor costs.
It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims. | A demolder for and a method of separating and removing mold material formed around two rail ends of longitudinally adjacent railroad rails during the use of a thermite weld system to join the rails into a continuous rail. The demolder includes an open-ended steel box sized to be positioned about the mold material having substantially aligned slots provided on opposite sides of the box to freely receive the rail and a handle extending upwardly from the box for moving and handling the box. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of copending U.S. patent application Ser. No. 13/969,305, filed August 16, 2013, which is a continuation of U.S. patent application Ser. No. 13/673,227, filed on Nov. 9, 2012. The entire contents and disclosure of U.S. patent applications Ser. Nos. 13/969,305 and 13/673,227 are hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention generally relates to processing data, and more specifically, to processing media content in an incremental manner by a sequence of services.
[0003] In processes that involve media processing services, there is always a need to communicate the media content from service to service. As one service completes its processing, the service sends the processed media content to the next service in the workflow. Since media content is large, a considerable amount of time may be needed before being able to invoke the next service.
BRIEF SUMMARY
[0004] Embodiments of the invention provide a method, system and computer program product for servicing media content. In one embodiment, the method comprises using a multitude of services to process the media content by having each of the services process increments of the media content, one increment at a time; and orchestrating the order in which the services process the increments of the media content to process all of the media content in accordance with a defined procedure.
[0005] In an embodiment, content operations are requested from each of the multitude of services; and each of said services, in response to the request for content operations, indicates that said each service supports processing of increments of the media content.
[0006] In one embodiment, one of said services is a last service in said defined procedure; and after this last service has finished processing all of the increments of the media content, this last service indicates that the defined procedure to process all of the media content is complete.
[0007] In an embodiment, this last service requests an additional increment of the media content at multiple times; and in response to one of these requests for an additional increment of the media content, a message is sent to this last service indicating that no more data is to be processed by said last service.
[0008] In one embodiment, this last service indicates that the defined procedure is complete after the last service receives this message.
[0009] In an embodiment, each of a first group of the services obtains the increments of the media content from another one of the services.
[0010] In one embodiment, a message is sent to each service of the first group of the services identifying the other one of the services from which said each service obtains the increments of the media content.
[0011] In an embodiment, each service of the first group of services is informed of a specified port from which said each service obtains the increments of the media content.
[0012] In one embodiment, the increments of the media content are passed, one increment after another, to at least a plurality of the services in a defined order.
[0013] In an embodiment, each time one of said plurality of services passes one of the increments of the media content to a subsequent one of the services in the defined order, the one of the plurality of services requests another one of the increments of the media content from a preceding one of the services in the defined order.
[0014] Embodiments of the invention enable the processing of media content in a pipeline mode. Data are produced and consumed incrementally. This allows a workflow to complete much faster, increasing the efficiency of the whole process.
[0015] Embodiments of the invention provide a rich media middleware system and services that produce and consume media content. Embodiments of the invention configure the services to create and process content incrementally. Embodiments of the invention also define how data are exchanged among services in order to be processed sequentially as part of a workflow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 illustrates a media content flow in accordance with an embodiment of the invention.
[0017] FIG. 2 shows the state diagram implemented by a service in embodiments of the invention.
[0018] FIG. 3 depicts an alternate embodiment of the present invention.
[0019] FIG. 4 shows two examples of a media workflow execution, one without the invention and one with an embodiment of the invention.
[0020] FIG. 5 shows a computing environment in which embodiments of the invention may be implemented.
DETAILED DESCRIPTION
[0021] As will be appreciated by one skilled in the art, embodiments of the present invention may be embodied as a system, method or computer program product. Accordingly, embodiments of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, embodiments of the present invention may take the form of a computer program product embodied in any tangible medium of expression having computer usable program code embodied in the medium.
[0022] Any combination of one or more computer usable or computer readable medium(s) may be utilized. The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CDROM), an optical storage device, a transmission media such as those supporting the Internet or an intranet, or a magnetic storage device. Note that the computer-usable or computer-readable medium could even be paper or another suitable medium, upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. In the context of this document, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-usable medium may include a propagated data signal with the computer-usable program code embodied therewith, either in baseband or as part of a carrier wave. The computer usable program code may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc.
[0023] Computer program code for carrying out operations of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
[0024] The present invention is described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a computer-readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.
[0025] The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0026] Embodiments of the invention provide a method, system and computer program product to process media content, and more specifically, to stream media content in content-centric business processes. With reference to FIG. 1 , embodiments of the invention use a process orchestration engine 102 and media services 104 that can participate in a process. Generally, the orchestration engine 102 executes workflows (processes) involving media services, and the orchestration engine controls the execution flow by calling the services in the appropriate sequence and by setting up the services for the exchange of incremental data. The services 104 interact with each other to produce and consume the media content incrementally. In embodiments of the invention, media services in a workflow can be processing the same media content concurrently (but with each service working on different parts of the media content).
[0027] In embodiments of the invention, the services 104 implement two separate interfaces: one to communicate with the orchestration engine 102 , and another for the exchange of data.
[0028] In the example shown in FIG. 1 , three services support the incremental data exchange. Service 1 creates content, Service 2 transforms content, and Service 3 stores the content.
[0029] At 112 , orchestration engine 102 sends a request message to Service 1 to produce a content. The request also inquires if the service supports incremental data creation. At 114 , Service 1 sends an acknowledgement message to the orchestration engine 102 indicating that the Service supports creation of incremental data, and informing the orchestration engine of the port (port “a”) where the created data will be made available.
[0030] At 116 , the orchestration engine 102 invokes Service 2 to transform the content. The request message informs Service 2 that Service 1 is producing the data incrementally at port “a.” The request message also asks if Service 2 can handle incremental data and what port Service 2 uses to stream the transformed data. At 120 , Service 2 , sends an acknowledgement message to the orchestration engine indicating that the Service supports incremental data, and specifying the port (port “b”) the Service uses for the transformed data.
[0031] At 122 , Service 2 requests data from Service 1 through port “a.” At 124 , a first piece of data is transferred from Service 1 to Service 2 for processing. In embodiments of the invention, subsequent pieces of data are transferred from Service 1 to Service 2 every time a processed piece of content is moved along in the workflow.
[0032] At 126 , Service 3 is called by the orchestration engine 102 and informed that content for consumption is available at port “b” of Service 2 . Service 3 is also asked if it can handle incremental data. At 130 , Service 3 sends an acknowledgement message to the orchestration engine to inform the orchestration engine that Service 3 supports incremental data and makes the processed data available at port “c.”
[0033] At 132 , Service 3 requests data from Service 2 through port “b.” A first piece of data is moved to Service 3 for processing. Since Service 3 is the last service in the chain, there will be no request to get processed data from Service 3 . At 134 , as processed content from Service 2 is moved along to Service 3 , Service 2 asks for more content from Service 1 .
[0034] The above-described interaction between services 104 through the respective ports continues until all pieces of data are moved from Service 1 to Service 3 . If a Service requests more data and receives a response indicating that there is no more data, this indicates that the requesting service has reached the end of the content. When this happens, the service sends a notification message, for instance at 136 and 140 , to the orchestration engine 102 informing the orchestration engine that the service has completed the request from the orchestration engine.
[0035] FIG. 2 is a state diagram to be implemented by a service to support incremental data processing in embodiments of the invention. At state 202 , the service is idle, and when the service receives a request from the orchestration engine 102 , the service moves to a setup state 204 , where the service prepares to perform the service it provides. From the setup state, the service transitions to state 206 . At this state 206 , the service reads input, which may be data from a previous service. As the service reads the input, some data may be put in a buffer, as represented at 210 .
[0036] When ready, the service processes data and outputs processed data, as represented at 212 and 214 . Processed data may be temporarily stored in a buffer, as represented at 216 . After outputting data, the service returns to state 206 to process more data. This process is repeated until the service receives a message that no more data is available. When this occurs, the service, at 220 , sends a message to the orchestration engine 102 indicating that the request from the orchestration engine has been completed. The service then returns to the idle state 202 .
[0037] FIG. 3 illustrates an alternate embodiment of the invention, comprising an orchestration layer 302 , a mediation layer 304 , and a services layer 306 ; and in this embodiment, five services 310 are provided. In operation, the orchestration layer executes workflows involving media services, and the orchestration layer controls the execution flow by calling the services in the appropriate sequence and by setting up the services for the exchange of incremental data. The services 310 interact with each other to produce and consume the media content incrementally; and the media services in the workflow can be processing the same media concurrently, but with each service working on different parts of the media content.
[0038] The orchestration layer 306 may implement a program, represented at 312 , which determines whether, and in what order, the services 310 are invoked. With the embodiment represented in FIG. 3 , not all the services are performed for each increment of data. Depending on the decisions made in program 312 at 314 , some data will be processed by Service 3 and other data will be processed by Service 4 .
[0039] Mediation layer 304 implements the two separate interfaces: one for the communications between the orchestration layer 302 and the services layer 306 , and another for the exchange of data.
[0040] Embodiments of the invention allow a workflow to complete much faster, increasing the efficiency of the entire media processing. As an example, FIG. 4 shows, at 402 , how long it may take to process media content in a conventional manner and, at 404 , how long it may take to process that media content by using an embodiment of this invention.
[0041] With the examples shown in FIG. 4 , the media content is data from a high definition camera, and the media content is processed by five services 406 . With the conventional approach 402 , all the data, 500 GB, from the camera, is fully processed by each service, one service at a time. Each of the first three services takes an hour to process the data, the fourth service takes 1.6 hours, and the last service takes ten minutes. The processing thus takes four hours and forty-six minutes.
[0042] With using an embodiment of the invention, the 500 GB input from the camera are processed in 1 GB increments. When the first service finishes processing an increment of data, that data is passed to the second service and the first service begins to process another increment of the input data. When the second service finishes processing this increment of data, that increment of data is passed to the third service. The second service, at about the same time, receives a second increment of data from the first service.
[0043] The increments of data are processed and passed in this way, from one service to the next, until all the data have been received and processed by the last service. Each of the first four services takes approximately ten seconds to process each increment of data; and the last service, repository, takes about 1.6 hours to process all the data. The entire amount of time needed to process the input from the camera is approximately one hour and thirty-seven minutes, which is about one-third of the times required by the current approach.
[0044] A computer-based system 500 in which embodiments of the invention may be carried out is depicted in FIG. 5 . The computer-based system 500 includes a processing unit 510 , which houses a processor, memory and other systems components (not shown expressly in the drawing) that implement a general purpose processing system, or computer that may execute a computer program product. The computer program product may comprise media, for example a compact storage medium such as a compact disc, which may be read by the processing unit 510 through a disc drive 520 , or by any means known to the skilled artisan for providing the computer program product to the general purpose processing system for execution thereby.
[0045] The computer program product may comprise all the respective features enabling the implementation of the inventive method described herein, and which—when loaded in a computer system—is able to carry out the method. Computer program, software program, program, or software, in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: (a) conversion to another language, code or notation; and/or (b) reproduction in a different material form.
[0046] The computer program product may be stored on hard disk drives within processing unit 510 , as mentioned, or may be located on a remote system such as a server 530 , coupled to processing unit 510 , via a network interface such as an Ethernet interface. Monitor 540 , mouse 550 and keyboard 560 are coupled to the processing unit 510 , to provide user interaction. Scanner 580 and printer 570 are provided for document input and output. Printer 570 is shown coupled to the processing unit 510 via a network connection, but may be coupled directly to the processing unit. Scanner 580 is shown coupled to the processing unit 510 directly, but it should be understood that peripherals might be network coupled, or direct coupled without affecting the performance of the processing unit 510 .
[0047] The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or to limit the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope of the invention. The embodiments were chosen and described in order to explain the principles and application of the invention, and to enable others of ordinary skill in the art to understand the invention. The invention may be implements in various embodiments with various modifications as are suited to the particular use contemplated. | A method, system and computer program product for servicing media content. In one embodiment, the media content is processed by having each of a group of services process increments of the media content, one increment at a time; and the order in which the services process these increments is orchestrated to process all of the media content in accordance with a defined procedure. In one embodiment, the increments of the media content are passed, one increment after another, to at least a plurality of the services in a defined order. In an embodiment, each time one of the plurality of services passes one of the increments of the media content to a subsequent one of the services in the defined order, the one of the plurality of services requests another increment of the media content from a preceding one of the services in the defined order. | 7 |
The present patent document is a continuation of U.S. patent application Ser. No. 14/324,664, filed Jul. 7, 2014, entitled “COORDINATION OF VIDEO AND/OR AUDIO RECORDING”, the disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
This invention relates generally to video and/or audio recording of events and, more specifically, minimizing any gaps in coverage of such recordings.
BACKGROUND
The proliferation of mobile devices (phones, tablets, etc.) has created a huge increase in video and audio recordings. Billions of hours of video are watched each month on the Internet and over 100 hours of video are uploaded to the Internet every minute.
Often times it is difficult to get a complete recording of an event without any coverage gaps. This can result from a variety of circumstances such as, for example, poor vantage point, dead battery, poor lighting, and obstructions.
SUMMARY
In general, embodiments described herein provide a method, system and computer readable program for reducing gaps in coverage of audio and/or video recording by mobile devices. In one aspect, an event to be recorded is initiated with a centralized recording coordination server. A plurality of mobile recording devices is registered with the centralized recording coordination server. As recording takes place, data is transmitted to the centralized recording server. The centralized recording coordination server substantially continuously analyzes the recorded data to identify any gaps in coverage of the event. Upon identifying any potential or actual gaps, the centralized coordination server then requests mobile recording devices to initiate or continue recording to reduce any potential gaps in recording.
In an alternate aspect, a system for reducing gaps in recording coverage includes a centralized recording coordination server. A plurality of mobile recording devices is in network connection with the centralized recording coordination server such that data is transmitted by the mobile recording devices for recording on the centralized recording server. The centralized recording coordination server analyzes the recorded data to identify any gaps in coverage of an event, and when identified, requests one or more mobile recording devices to initiate or continue recording to reduce any potential gaps in recording.
In still another aspect, a computer program product contains programmed instructions for reducing gaps in recording coverage. The program instructions, which are stored on a computer readable storage medium, initiate an event to be recorded with a centralized recording coordination server. After a plurality of mobile recording devices is registered with the centralized recording coordination server, programmed instructions analyze the data transmitted by the plurality of mobile recording devices and identifies any gap in coverage of the event. When any gaps are identified, the programmed instructions cause one or more mobile recording devices to initiate or continue recording to reduce the gap in coverage of the event.
In still another aspect of the present invention provides a method for deploying a system for reducing gaps in coverage of audio and/or video recording by mobile devices comprising, providing a computer infrastructure being operable to: initiate an event to be recorded with a centralized recording coordination server; registering a plurality of mobile recording devices with the centralized recording coordination server; receiving data transmitted to the centralized recording server and substantially continuously analyzing the recorded data to identify any gaps in coverage of the event; and upon identifying any potential or actual gaps, requesting one or more mobile recording devices to initiate or continue recording to reduce any potential gaps in recording.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings in which:
FIG. 1 shows a pictorial representation of an environment in which the invention may be implemented according to illustrative embodiments;
FIG. 2 shows a pictorial representation of an environment in which the invention may be implemented according to illustrative embodiments; and
FIG. 3 shows a process flow of an implementation of providing coordination of video recording according to illustrative embodiments.
The drawings are not necessarily to scale. The drawings are merely representations, not intended to portray specific parameters of the invention. The drawings are intended to depict only typical embodiments of the invention, and therefore should not be considered as limiting in scope. In the drawings, like numbering represents like elements.
DETAILED DESCRIPTION
Several embodiments now will be described more fully herein with reference to the accompanying drawings. It will be appreciated that this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of this disclosure to those skilled in the art.
Furthermore, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, the use of the terms “a”, “an”, etc., do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. It will be further understood that the terms “comprises” and/or “comprising”, or “includes” and/or “including”, when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.
Unless specifically stated otherwise, it may be appreciated that terms such as “processing,” “computing,” “determining,” “evaluating,” or the like, refer to the action and/or processes of a computer or computing system, or similar electronic data center device, that manipulates and/or transforms data represented as physical quantities (e.g., electronic) within the computing system's registers and/or memories into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or viewing devices. The embodiments are not limited in this context.
Referring now to FIG. 1 , a computerized implementation 100 of an embodiment will be shown and described. As depicted, implementation 100 includes continuous recording continuation server 104 deployed within a computer system 102 running in a networked environment. This is intended to demonstrate, among other things, that the present invention could be implemented within a network environment (e.g., the Internet, a wide area network (WAN), a local area network (LAN), a virtual private network (VPN), etc.), a cloud-computing environment, or on a stand-alone computer system. Communication throughout the network can occur via any combination of various types of communication links. For example, the communication links can comprise addressable connections that may utilize any combination of wired and/or wireless transmission methods. Where communications occur via the Internet, connectivity could be provided by conventional TCP/IP sockets-based protocol, and an Internet service provider could be used to establish connectivity to the Internet. Still yet, computer system 102 is intended to demonstrate that some or all of the components of implementation 100 could be deployed, managed, serviced, etc., by a service provider who offers to implement, deploy, and/or perform the functions of the present invention for others.
The continuous recording coordination system and method of an embodiment of the invention consists of server application 104 running within a general purpose computer system 102 and in communication with a client application 106 running on mobile devices. In this particular example, continuous recording coordination server 104 represents an illustrative system for providing coordination of video recording. It should be understood that many different types of general purpose computers may have different components/software running on them, but will be able perform similar functions.
In accordance with one embodiment of the invention, continuous recording coordination client software 106 runs on any device that includes video and/or audio recording capability. Such devices may include, but are not limited to, mobile phone 108 , tablet computing device 110 and digital camera 112 . Other recording devices, whether now known or developed in the future, may also be used.
Mobile devices 108 , 110 and 112 have the ability to communicate with the continuous recording coordination server, and optionally with each other, via any means now known or that may be known in the future. This networking of devices via communication network 114 include, but are not limited to, wireless networking, Bluetooth, cellular communication (2G, 3G, LTE, etc.). All that is required is for the devices 108 , 110 , 112 to be networked such that they have secure connection to transfer data.
Each of the devices 108 , 110 , 112 is registered as a trusted party either with each other and/or with the continuous recording coordination server 104 . Such trust relationships can be established via any known techniques including, but not limited to, connection to same secure wireless connection, use of a shared token, registration via an application running in all devices, etc.
Referring to FIG. 2 , general purpose computer system 102 is depicted. It is typically operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with computer system 102 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments that include any of the above systems or devices and the like.
The components of computer system 102 may include, but are not limited to, one or more processors or processing units 150 , a system memory 152 , and a bus 154 that couples various system components including system memory 152 to processor 150 .
Bus 152 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus.
Computer system 102 typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computer system 102 , and it includes both volatile and non-volatile media, removable and non-removable media.
System memory 152 can include computer system readable media in the form of volatile memory, such as random access memory (RAM) 160 and/or cache memory 162 . Computer system 102 may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system 164 can be provided for reading from and writing to a non-removable, non-volatile magnetic media (not shown and typically called a “hard drive”). Although not shown, a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”), and an optical disk drive for reading from or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD-ROM or other optical media can be provided. In such instances, each can be connected to bus 154 by one or more data media interfaces. As will be further depicted and described blow, memory 152 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the invention.
Program/utility 170 , having a set (at least one) of program modules 172 , may be stored in memory 152 by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. Each of the operating system, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Program modules 172 generally carry out the functions and/or methodologies of embodiments of the invention as described herein.
Computer system 102 may also communicate with one or more external devices 180 such as a keyboard, a pointing device, a display 182 , etc.; one or more devices that enable a user to interact with computer system 102 ; and/or any devices (e.g., network card, modem, etc.) that enable computer system 102 to communicate with one or more other computing devices. Such communication can occur via Input/Output (I/O) interfaces 184 . Still yet, computer system 102 can communicate with one or more networks such as a local area network (LAN), a general wide area network (WAN), cellular telephone networks and/or a public network (e.g., the Internet) via network adapter 186 . As depicted, network adapter 186 communicates with the other components of computer system via bus 154 . It should be understood that although not shown, other hardware and/or software components could be used in conjunction with computer system 102 . Examples include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.
In general, general purpose computer system 102 executes computer program code, such as program code for continuous recording coordination server 104 , which is stored in memory 152 associated with computer system 102 .
The general purpose computer system 102 may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, people, components, logic, data structures, and so on, which perform particular tasks or implement particular abstract data types. Computer system 102 may be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.
As depicted in FIG. 1 , the continuous recording coordination system operates through the interaction of the client software 106 and the software of continuous recording coordination server 104 , which together carry out the methodologies disclosed herein. Shown in FIG. 3 is a process flow 200 for providing the recording coordination in accordance with an embodiment of the invention.
As depicted in block 201 , a user attends an event and initiates the continuous recording client application on his recording device. The client application establishes communication over a network (as described above) with the continuous recording coordination server. A list of events or communities that have already been created is displayed on the recording device. If this particular event has not been created, then the continuous recording coordination server permits the user to create one. If this particular event has already been created, then the user can indicate that it desires to join the particular event/community.
As depicted in block 202 , the user, and any other users who have joined this particular community, starts recording the event. After the event starts, a number of external things can occur that may affect continuous coverage of the event. Such possible external events represented by block 203 include, but are not limited to:
1. One or more users who started recording the event stop recording for one reason or another, or indicate to the continuous recording system their intent to stop recording. 2. The quality of the recording by one or more of the recording devices is degraded. 3. The view from one or more of the recording devices has been obstructed. 4. The number and angles of current recording devices are insufficient to avoid any gaps in coverage
As depicted in block 204 , the algorithms of the continuous recording coordination system substantially continuously analyze the data that it receives from all of the recording devices. Each device also shares its metadata which can be used by the coordination algorithms to select the best device when switching the primary recorder; such metadata can include, without limitation:
1. Device name; brand, model, etc
2. Device resolution specification; such as 10 MP, 15 MP, etc
3. Recording time remaining
4. Sound quality (hardware and also could be audio being recorded—as it can be far away from speaker of event)
The continuous recording coordination system can also update the rank of the quality of the recording based on real time characteristics. Such factors include:
1. Shakiness (or unsteadiness) of the video (i.e. One person is using a handheld with shaky hands vs. someone else using a smooth tripod)
2. Sharpness of focus (no one wants a blurry image)
3. Sound volume/quality
4. Level of background noise
5. Lighting level (i.e. well balanced lighting where everyone is visible vs. a too dark or too bright image.
6. Resolution of video image
7. Quality of lens
If the outcome of the analysis of the algorithms in block 203 results in a determination that it would be desirable to locate additional users to record the event for one reason or another, the system then locates additional users who are part of the community (block 205 ) and meet the threshold requirements to participate in the recording to minimize the possibility of gaps in the coverage (block 206 ). These threshold requirements include, but are not limited to, remaining battery life, device location, device resolution, memory, sound volume, lighting level etc. for which metadata are sent from device to the server application.
Referring to block 207 , when the server application identifies additional user(s) who meet the requirements to participate in the community recording, it sends a message to such additional user(s) inquiring whether they are willing to start recording. When the system receives an affirmative response, it can either stop looking for additional users, or continue to seek out additional users to improve the coverage. In either occurrence, the additional user(s) begin to record the event (block 202 ) and the system loops back to block 204 and continues to monitor and analyze the current recordings until the event is completed. If there are no additional users available, the server application will so inform the user that is currently recording so that it can continue recording, if possible.
As an example of one alternative embodiment of the invention, consider the following non-limiting situation, in which two parents are attending their child's 5th grade music concert. They arrive and sit down in two seats in the front row, open their smartphones and launch an application (or “app” for short) made in accordance with one embodiment of the present invention called the “Community Video Group”. This app was previously downloaded and stored on the smartphones and is now in communication over a network with a companion recording communication application that is running on a network server. Once the app is launched, the two parents then join a virtual community created by another parent 10 minutes earlier, called the “Hemmeter Elementary 5th Grade Music Concert” community. The virtual community is scheduled to last for the length of the concert, which is 90 minutes.
Two other parents who are scattered about the gymnasium also join the virtual community. All the parents begin recording the concert. Five minutes before the concert is scheduled to end, it is detected that three of the four parents have stopped recording the concert and the remaining one is about to run out of power. In order to head off any possible gap in video coverage of the concert, the system of the invention determines it should have another video recorder ready to go. The system then finds a member still connected to the virtual community with the most capable smartphone and sufficient battery life. This happens to be a parent named “Amber”.
Amber receives a message window on her smartphone asking her if she would be willing to record the remaining 5 minutes of the concert. She indicates affirmatively and the system sends Amber's device a 10 second countdown to start recording. It also syncs this countdown message with the other parents who have stopped recording. In this manner, the system continues to find the most capable devices and ensures that at least one device is always recording.
Additionally, after Amber begins recording, the system is substantially continuously checking to see if any of the recordings have undesirable qualities such as: 1) an obstruction of someone's head right in front of the camera, 2) poor lighting from the area she is sitting, and/or 3) she keeps focusing in on her own child instead of panning out to view the entire group. The system can then solicit additional people to begin recording in an attempt to attain a good quality recording that can be reused by others.
In other embodiments of the invention, a mobile device can be informed where other devices in the community are located, and it may optionally display a map of where each device is located in relation to the device displaying the map. Additionally, indication of the angle of video recording for active recording devices may be reflected in the display. A device can have multiple displays shown in a screen (or in a series of screen) to view them; such as 1 view on a screen, 2 views, 4 views, etc. The content of each display may be a recent static image captured from the recording to give the user perspective of what is covered by the current recording team (frequency of captures would be controlled by the source device configuration and likely tuned to device capacity/capability).
In another embodiment, the invention provides a method that performs the process of the invention on a subscription, advertising, and/or fee basis. That is, a service provider, such as a Solution Integrator, could offer to provide recording coordination functionality to minimize gaps in recording coverage. In this case, the service provider can create, maintain, support, etc., a computer infrastructure, such as computer system 102 ( FIG. 2 ) that performs the processes of the invention for one or more consumers. In return, the service provider can receive payment from the consumer(s) under a subscription and/or fee agreement and/or the service provider can receive payment from the sale of advertising content to one or more third parties.
In still another embodiment, the invention provides a computer-implemented method for coordinating the recording of events. In this case, a computer infrastructure, such as computer system 102 ( FIG. 2 ), can be provided and one or more systems for performing the processes of the invention can be obtained (e.g., created, purchased, used, modified, etc.) and deployed to the computer infrastructure. To this extent, the deployment of a system can comprise one or more of: (1) installing program code on a computing device, such as computer system 102 ( FIG. 2 ) or mobile devices (e.g. 108 , 110 , 112 in FIG. 1 ), from a computer-readable medium; (2) adding one or more computing devices to the computer infrastructure; and (3) incorporating and/or modifying one or more existing systems of the computer infrastructure to enable the computer infrastructure to perform the processes of the invention.
Process flow of FIG. 3 illustrates the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the blocks might occur out of the order depicted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently. It will also be noted that each block of flowchart illustration can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
Some of the functional components described in this specification have been labeled as systems or units in order to more particularly emphasize their implementation independence. For example, a system or unit may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A system or unit may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like. A system or unit may also be implemented in software for execution by various types of processors. A system or unit or component of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions, which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified system or unit need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the system or unit and achieve the stated purpose for the system or unit.
Further, a system or unit of executable code could be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices and disparate memory devices.
Furthermore, systems/units may also be implemented as a combination of software and one or more hardware devices. For instance, a system or unit may be the combination of a processor that operates on a set of operational data.
Also noted above, some embodiments may be embodied in software. The software may be referenced as a software element. In general, a software element may refer to any software structures arranged to perform certain operations. In one embodiment, for example, the software elements may include program instructions and/or data adapted for execution by a hardware element, such as a processor. Program instructions may include an organized list of commands comprising words, values, or symbols arranged in a predetermined syntax that, when executed, may cause a processor to perform a corresponding set of operations.
Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.
Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages.
Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.
These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks.
The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.
It is apparent that there has been provided approaches for providing a continuous recording coordination system and method. While the invention has been particularly shown and described in conjunction with several embodiments, it will be appreciated that variations and modifications will occur to those skilled in the art. Therefore, it is to be understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the invention. | Approaches described herein provide coordination of audio and/or video recording to minimize any gaps in coverage. In one approach, users of a distributed set of recording devices are invited to join a community with other similar users via a networked application in a loosely collaborative way. The recording coordination application substantially continuously monitors the state of the recording activities and coordinates the community of users to reduce any gaps in coverage. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 USC 119 to Japanese Patent Application No. 2005-232016 filed on Aug. 10, 2005 the entire contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a quick connector which includes a male connector member and a female connector member, to connect hoses, pipes or the like, for transferring various fluids.
DESCRIPTION OF BACKGROUND ART
[0003] Generally, there is known a quick connector which is provided with a female connector member, a male connector member which fits into this female member via a sealing member, and a retainer which exists in a circular space between the connector members and which is interposed between the inner periphery of the female connector member and the outer periphery of the male connector member to be engaged therewith, thereby preventing the male connector member from coming off from the female connector member in the axial direction. See, for example, JP-A No. 201355/1999. This type of connector can be removed and disassembled easily without using a tool such as a releasing tool. In addition, this type of connector has another advantage in that the retainer is reusable.
[0004] However, in the configuration as described above, a portion where the female connector member seals and retains the male connector member is offset away from a portion where the male connector member is fixed on the female connector member. Therefore, there is a possibility that vibrations may occur on each component.
SUMMARY AND OBJECTS OF THE INVENTION
[0005] In order to further improve the conventional art as described above, an object of the present invention is to provide a quick connector which is capable of reducing wobbling due to vibrations.
[0006] An embodiment of the present invention is directed to a quick connector which is provided with, a female connector member, a male connector member which fits into the female connector via a sealing member, and a retaining member which exists in a circular space between these connector members, that is interposed between the inner periphery of the female connector member and the outer periphery of the male connector member to be engaged therewith, thereby preventing the male connector member from coming off in the axial direction. A locking ring is provided having a first fitting part which fits between the inner periphery of the retaining member and the outer periphery of the male connector member on the outer periphery of the male connector member.
[0007] According to an embodiment of the present invention, the first fitting part of the locking ring fits between the inner periphery of the retaining member and the outer periphery of the male connector member. Therefore, the support strength between the male connector member and the retaining member is improved, whereby vibrations of the members can be suppressed.
[0008] In this case, the locking ring may be provided with a second fitting part which fits between the inner periphery of the female connector member and the outer periphery of the male connector member. Since this configuration includes the second fitting part, the support strength between the male connector member and the female connector member is improved, thereby suppressing the vibration of each member even further.
[0009] It is also possible that the locking ring is provided with a locking ring body, and a pair of operational pieces which extend continuously from the locking ring body and extend to the direction for intersecting the connector central line. In this configuration, the pair of operational pieces thus provided may enhance the assembling properties of the locking ring. Furthermore, the retaining member is provided with operational arm parts for a diameter-reduction operation, and the direction to which a pair of the operational pieces extends may be orthogonal to the direction to which the operational arm parts extend. In this configuration, even in the case where the operational pieces are bent and simultaneously the operation for bending the operational arm of the retaining member is performed, it can be carried out easily without a loss of operability. Furthermore, the locking ring may be configured such that a projecting amount of the second fitting part from the locking ring body is smaller than a stroke amount at the time when the locking ring is operated. Since the stroke amount is larger, it is possible to easily detach and attach the locking ring.
[0010] The second fitting part may be formed on both surfaces of the locking ring body. In this configuration, the locking ring body is available for use regardless of the sides, front or back. Therefore, erroneous assembling can be prevented and this enhances the assembling properties. In addition, the male connector member may be provided with a positioning part for aligning the locking ring. This may enhance the assembling properties of the locking ring, as well as preventing the locking ring from dropping off.
[0011] In an embodiment of the present invention, not only is the reuse of the retaining member is easily performed, but also the removing and disassembling are easy even without using a tool such as releasing tools. In addition, wobbling of the member due to vibrations can be reduced.
[0012] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
[0014] FIG. 1 is a side view of an ATV vehicle relating to one embodiment of the present invention;
[0015] FIG. 2 is a top view of the ATV vehicle;
[0016] FIG. 3 is a perspective view of the vicinity of a throttle body of the ATV vehicle;
[0017] FIG. 4 is a perspective view of the throttle body;
[0018] FIG. 5 is a cross-sectional view of a quick connector;
[0019] FIG. 6 is a cross-sectional view of the quick connector;
[0020] FIG. 7 is a perspective view of a retaining member and a locking ring;
[0021] FIG. 8 a to FIG. 8 d are a plan view and cross-sectional views of the locking ring;
[0022] FIG. 9 is a longitudinal cross-sectional view of the quick connector at the time of coupling; and
[0023] FIG. 10 is a transverse cross-sectional view of the quick connector at the time of coupling.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Hereinafter, one embodiment of the present invention will be explained with reference to the accompanying drawings. Orientations such as front, back, right, and left described in the following are identical to those with respect to the traveling direction of a vehicle, unless otherwise specified. In the drawings, arrow FR, arrow LH, and arrow UP indicate, respectively, the front side of the vehicle, left side of the vehicle, and upper side of the vehicle.
[0025] A saddle-ride type vehicle 1 of the present embodiment is a so-called ATV, whose front and rear wheels 2 and 3 are equipped with low-pressure balloon tires having a large diameter, assuring a large minimum road clearance to enhance the operation through performance mainly on the uneven road.
[0026] An engine 5 arranged in a vertical layout is mounted on nearly the center of the vehicle frame 4 , and power is outputted to each propeller shaft 8 , 9 , respectively, for the front wheel and the rear wheel, via a change gear that is not illustrated. The propeller shafts 8 , 9 transmit power respectively to the front and rear wheels 2 , 3 , via power distribution mechanisms 11 , 12 . It is to be noted that in the present embodiment, a crankcase 6 constituting the lower part of the engine 5 also serves as a change gear case which accommodates the change gear.
[0027] The vehicle body frame 4 includes upper pipes 41 and lower pipes 42 which extend approximately along the longitudinal direction of the vehicle body, and which are provided on the right and the left sides thereof. Pipe linkages are made by linking both pipes 41 , 42 on both sides of the vehicle body that are combined by multiple cross pipes 75 , 75 A (see FIG. 2 ), thereby constituting almost a box-like structure.
[0028] An engine 5 is mounted nearly at the center position on the bottom side of the vehicle frame 4 , and the cylinder head 7 part of the engine 5 is placed at a position slightly lower than the upper pipes 41 . At a position on the vehicle rear side of the engine 5 , the vehicle body frame 4 is provided with an air cleaner 18 of an engine inlet system.
[0029] This air cleaner 18 is connected to the inlet part on the rear side of the cylinder head 7 via a throttle body 17 . At a position that is offset in the vehicle width direction from the throttle body 17 on the front side of the air cleaner 18 , there is provided a snorkel 54 which extends obliquely in an upwardly and forward direction. Outside air is introduced from the opening on the front end of the snorkel 54 . An injector 17 a which is a fuel introducing part is integrally assembled with the throttle body 17 . Fuel that is supplied from the fuel pump 51 described below is controlled by the controller (not illustrated), and injected into the inlet path.
[0030] On the other hand, the front part of the cylinder head 7 is connected to the base end part of an exhaust pipe 19 . The exhaust pipe 19 extends once to the front side and then is bent rearwardly, so that it is connected to the silencer 21 on the vehicle rear side.
[0031] A fuel tank 22 , made of resin, is placed on the upper side of the engine 5 . On the rear side of the fuel tank 22 , there is provided an openable and closable saddle-ride type seat 23 , in such a manner that the upper side of the throttle body 17 , the snorkel 54 , the air cleaner 18 , and the like are covered with this seat. Handlebar stem parts 43 are provided on the front side position of the engine in the vehicle body frame 4 . The handlebar stem parts 43 support a steering shaft 25 .
[0032] This steering shaft 25 is equipped with a handlebar 24 on the upper end thereof, having a shape of a bar, and a front wheel steering mechanism, not illustrated, is coupled with the lower end of the steering shaft 25 . The front part of the fuel tank 22 curves in almost a U-shape, in such a manner to go around both sides of the steering shaft 25 , thereby ensuring sufficient capacity.
[0033] Then, on the lower side of the fuel tank 22 , a fuel pump 51 is placed in such a manner as to be positioned on the front side of the engine 5 . A communication pipe 52 extends downwardly from the fuel tank 22 and is connected to the inlet port of the fuel pump 51 . A fuel supply pipe 53 , for supplying discharged fuel to the injector 17 a , is connected to the outlet port of the fuel pump 51 .
[0034] On the other hand, a heat shield plate 46 is mounted immediately below the position where almost a rear half part of the fuel tank 22 to the front part of the seat 23 is located. The heat shield plate is placed across the left and right upper pipes 41 , 41 of the vehicle frame 4 . The heat shield plate 46 partitions the engine 5 , and the fuel tank 22 and the seat 23 on the upper side thereof, thereby serving as a shield to interrupt the spread of high heat from the engine 5 towards the fuel tank 22 and the seat 23 .
[0035] The fuel supply pipe 53 , one end of which is connected to the fuel pump 51 , is drawn upwardly from the front-end part of the heat shield plate 46 , and installed along the upper surface of heat shield plate 46 . As shown in FIG. 2 , the fuel supply pipe 53 is bent in a shape of a crank from the top view, on the upper surface side of the heat shield plate 46 , so as to go around the snorkel 54 and the like which extend from the air cleaner 18 towards an upper side of the heat shield plate 46 . A portion of the bent part of the fuel supply pipe 53 is locked on a set position on the heat shield plate 46 via the clamp 55 as a part that is fixed in position.
[0036] The snorkel 54 is coupled and supported by the near center of the rear end part of the heat shield plate 46 and is joined with a bolt or the like. On a position of the snorkel 54 , a little tilted to the vehicle rear side rather than in conjunction with the heat shield plate 46 , there is provided a resonator 71 (vehicle body component) which is branching off towards the left side direction of the vehicle body. As shown in FIG. 3 , this resonator 71 projects in approximately a trapezoidal shape, towards the vehicle rear side from the connection pipe part.
[0037] Under the condition that the seat 23 is raised upwardly, the air cleaner 18 , snorkel 54 , and the like which are located below the seat 23 are exposed to the outside of the vehicle together with the upper pipes 41 and the like of the vehicle body frame 4 . However, the upper side of the throttle body 17 is provided with a protect cover 80 made of resin, and the protect cover 80 covers this throttle body 17 so as to prevent the upper surface thereof from directly being exposed to the outside of the vehicle.
[0038] As for the protect cover 80 , support arms 82 a , 82 b , and 82 c provided to extend on the peripheral border of the cover base 81 which is curved upwardly. One support arm 82 a is fixed by a clip 90 on a gusset plate 83 that is provided in such a manner as going across the joint between the cross pipe 75 A and the upper pipes 41 . Another support arm 82 b is located on the diagonal position of the support arm 82 a is fixed by the clip 91 on a flange, not illustrated, which is provided on the snorkel 54 in an extended manner.
[0039] The remaining support arm 82 c is a supplemental arm, having a curl part 82 d provided on the tip thereof, which is locked in such a manner as to wind around the near center of the cross pipe 75 A. Therefore, the protect cover 80 is supported by the vehicle body frame 4 having the cross pipe 75 A as a principal element and the snorkel 54 .
[0040] On the vehicle body left side of the cover base 81 , a guide wall 84 includes a circular arc shaped cross section which covers the upper side of the fuel supply pipe 53 . On the upper wall on the vehicle front side of the cover base 81 , a projecting part 85 that projects upwardly is formed. Inside the projecting part 85 , a component protecting space 93 is allocated to arrange the injector 17 a , a coupler 94 connected to the injector 17 a , a connector 95 , wiring 96 , and the like.
[0041] In FIGS. 1 and 2 , a vehicle body cover 31 is made of resin which covers the vehicle front part including the fuel tank. A front fender 32 and a rear fender 35 are provided that are made of resin for, respectively, covering the front wheels and the rear wheels. As illustrated in FIG. 1 , a front protector 33 and a front carrier 34 are provided together with a rear carrier 36 .
[0042] As shown in FIG. 1 , in the present embodiment, quick connectors 60 both have nearly the same structure and are connected between the communication pipe 52 and the fuel pump 51 , and between the fuel supply pipe 53 and the fuel pump 51 . As shown in FIGS. 3 and 4 , a quick connector 70 having a different structure connects between the fuel supply pipe 53 and the injector 17 a . In FIGS. 5 and 6 , the quick connector 60 is provided with a male connector member 61 , a female connector member 62 into which the male connector member 61 is inserted, a retaining member 63 for fixing the male connector member 61 so that it may not come off from the female connector member 62 and sealing members 64 , 65 for providing a seal between the male connector member 61 and the female connector member 62 .
[0043] As for the male connector member 61 , its base (positioning part) 61 a has a curved shape, and integrally continues to the cover member 51 a of the fuel pump 51 . At nearly the center thereof, being apart from the tip 61 b for a predetermined distance, projecting portions 61 c are provided that project in the centrifugal direction. The male connector member as a whole forms a stick-like member having a nearly pipe shape. The tip 61 b of the male connector member 61 is subjected to a drawing process so as to take the radius on the outer circumferential surface for facilitating insertion into the female connector member 62 . It is to be noted that the male connector member 61 forms a shape for rotational symmetry about the axis line.
[0044] The female connector member 62 is a nearly tubular shaped member produced from a single piece item that is, for example, made of a glass fiber reinforced nylon resin. The female connector member 62 includes a base 62 a , an intermediate part 62 b and a tip part 62 c . The communication pipe 52 (or the fuel supply pipe 53 ) is connected to the outer periphery of the tip part 62 c via an O-ring 66 .
[0045] On the periphery wall of the base end 62 a , a pair of window holes 62 d is formed in an opposed manner, each having a large opening, nearly rectangular shaped, with a size also available for checking assembly. On the inner wall of the intermediate part 62 b , a contact surface 62 e comes into contact with the outer surface of the ring-shaped sealing member 64 and an O-ring 65 is formed. In addition, a receiving surface 62 f is formed for receiving the tip 61 b of the male connector member 61 .
[0046] The retaining member 63 is a one-piece member made of polyamide resin, which is capable of being elastically deformed so that most of the retaining member 63 is inserted into the base 62 a of the female connector member 62 . As shown in FIG. 7 , the retaining member 63 is provided with a main body part 63 a having a cross section of almost a C shape, whose diameter can be expanded or reduced by the elastic deformation. The outside wall of the main body part 63 a is provided with a pair of locking parts 63 b for engaging with the end faces of the window holes 62 d , a pair of operational arm parts 63 c that is used for removing the quick connector, and a pair of locking hole parts 63 d for locking the projecting parts 61 c of the male connector member 61 .
[0047] As shown in FIGS. 5 and 6 , on the base 61 a of the male connector member 61 , there is arranged an elastically deformable locking ring 10 , which is made of rubber, polyamide resin, or the like. As shown in FIGS. 7 and 8 a to 8 d , the locking ring 10 is provided with a ring-shaped locking ring body 10 a . The locking ring body 10 a is provided with a first fitting part 10 b for abutting against the inner periphery surface 63 e of the retaining member 63 and which is capable of fitting between the inner periphery surface 63 e of the retaining member 63 and the outer periphery surface of the male connector member 61 . A pair of second fitting parts 10 c extend in almost a fan-like manner from each other in the periphery direction and is allowed to fit between the inner periphery surface of the female connector member 62 and the outer periphery part of the male connector member 61 , and a pair of operational pieces 10 d which project from the locking ring body 10 a and extend in the direction intersecting the connector center line.
[0048] The second fitting parts 10 c are integrally formed on both sides of the locking ring body 10 a , and even when the locking ring 10 is mounted mixing up the front and the back side thereof, the second fitting parts 10 c on either surface fit between the inner periphery part of the female connector member 62 and the outer periphery of the male connector member 61 .
[0049] When a pair of the operational pieces 10 d is pressed and bent in such a manner as pressing against the cover body 51 a of the fuel pump 51 , the operational pieces undergo displacement from the position as shown in FIG. 8 c to the position as shown in FIG. 8 d , for example. According to this displacement, the width dimension of the second fitting part 10 c is reduced in diameter from the dimension W 1 to the dimension W 2 . This operation for diameter reduction is carried out when the quick connector is removed as described below.
[0050] In FIG. 8 c , the projecting amount of the second fitting parts 10 c from the locking ring body 10 a is set to T 1 , and when a pair of the operational pieces 10 d is displaced, the second fitting parts 10 c go backward for the dimension T 2 beyond the projecting amount T 1 as shown in FIG. 8 d . This dimension T 2 is assumed as a so-called stroke amount at the time of operating the locking ring 10 . With this configuration, the stroke amount T 2 is set to be larger than the projecting amount T 1 .
[0051] In the configuration as described above, when a pair of the operational pieces 10 d is displaced, the width of the second fitting parts 10 c is reduced from W 1 to W 2 , and the second fitting parts 10 c go backward to the depth T 2 . Therefore, the second fitting parts 10 c can easily escape from the place between the inner periphery of the female connector member 62 and the outer periphery of the male connector member 61 .
[0052] Next, operations of the quick connector will be explained.
[0053] With reference to FIGS. 9 and 10 , for establishing a connection by the quick connector, first, the elastically deformable locking ring 10 is made to fit to the base 61 a of the male connector member 61 . Next, as shown in FIG. 9 , the O-ring 65 and the sealing member 64 sequentially in this order are made to fit into the intermediate part 62 b of the female connector member 62 . Furthermore, the retaining member 63 is inserted into the base 62 a . Then, the locking parts 63 b of this retaining member 63 are made to lock onto the end faces of the window holes 62 d of the female connector member 62 , and the retaining member 63 is held within the base 62 a of the female connector member 62 .
[0054] In other words, in the present procedure, the window holes 62 d of the female connector member 62 and the locking parts 63 b of the retaining member 63 are aligned in the circumferential direction, and this retaining member 63 is inserted into the base 62 a of the female connector member 62 . Since the retaining member 63 has a C-shape, it is inserted while the diameter is reduced. When the retaining member 63 arrives at a predetermined insertion depth, the locking parts 63 b of the retaining member 63 are urged towards the direction expanding the diameter by elasticity, and displaced towards the outside. Then, the locking parts 63 b are engaged with the window holes 62 d of the female connector member 62 . As a result, the retaining member 63 is held in the base 62 a of the female connector member 62 without coming off therefrom in the axial direction.
[0055] Here, the operational ends of the operational arm parts 63 c of the retaining member 63 are kept to be projecting from the insertion open end of the female connector member 62 .
[0056] Thereafter, the open end of the female connector member 62 and that of the retaining member 63 are positioned to the tip of the male connector member 61 , and the male connecter member 61 is inserted therein, to have nearly the same axis line. In this case, the locking ring 10 is made to rotate in the circumferential direction, and the positional relationship between the locking ring 10 and the retaining member 63 is maintained as the positional relationship shown in FIG. 7 .
[0057] Accordingly, the shaft of the male connector member 61 penetrates into the retaining member 63 , the sealing member 64 , and the O-ring 65 , sequentially in this order, and the tip 61 b of the shaft is accommodated in the receiving surface 62 f of the intermediate part 62 b of the female connector member 62 .
[0058] In this condition, the projecting parts 61 c of the male connector member 61 enter while pushing the retaining member 63 aside, and fits into the locking hole parts 63 d of the retaining member 63 . Further the first fitting part 10 b of the locking ring 10 fits between the inner periphery surface 63 e of the retaining member 63 and the outer periphery of the male connector member 61 . Then, the second fitting parts 10 c fit between the inner periphery of the female connector member 62 and the outer periphery of the male connector member 61 .
[0059] In the present configuration, the tip 61 b of the male connecter member 61 is held on the receiving surface 62 f of the female connector member 62 , and the first fitting part 10 b of the locking ring 10 fits between the inner periphery surface 63 e of the retaining member 63 and outer periphery of the male connector member 61 . Further, the second fitting parts 10 c fit between the inner periphery of the female connector member 62 and the outer periphery of the male connector member 61 . Therefore, this male connecter member 61 is held at two points, that is, on the receiving surface 62 f and at the first fitting part 10 b (second fitting parts 10 c ), thereby stabilizing the posture of the male connector member 61 against the female connector member 62 . Accordingly, wobbling between the male connector member 61 and the female connector member 62 is avoided, and further wobbling due to vibrations of each component can be suppressed, whereby the connection by the quick connecter can be stable.
[0060] Since the sealing member 64 and the O-ring 65 are held between the outer periphery surface of the male connector member 61 and the intermediate part 62 b of the female connector member 62 , high water tightness and air tightness can be obtained between the male connector member 61 and the female connector member 62 .
[0061] In removing and disassembling the quick connector, firstly by operating the operational pieces 10 d of the locking ring 10 , the locking ring 10 is removed.
[0062] In this case, the operational pieces 10 d are gripped and displaced from the position as shown in FIG. 8 c to the position as shown in FIG. 8 d . With this displacement, the second fitting parts 10 c are reduced in diameter to the width W 2 , and allowed to go backwardly to the depth T 2 . When this operation is carried out, the second fitting parts 10 c easily escape from between the inner periphery of the female connector member 62 and the outer periphery of the male connector member 61 . It is to be noted that in some cases, the locking ring 10 can be torn off for removal. In this state, simultaneously, the operational arm parts 63 c of the retaining member 63 are pressed to be shrunk by a fingertip or the like. Then, the locking parts 63 b of the retaining member 63 can be detached from the window holes 62 d of the female connector member 62 . Therefore, just by pulling out the male connector member 61 , the male connector member 61 and the retaining member 63 can be removed from the female connector member 62 .
[0063] In the aforementioned case, since the direction into which a pair of the operational pieces 10 d extends is orthogonal to the direction to which the operational arm parts 63 c extend, it is possible to improve the operability in performing the operation of the operational pieces 10 d and the operation of the operational arm parts 63 c simultaneously.
[0064] As shown in FIG. 5 , in the quick connector 60 , the base 61 a of the male connector member 61 has a curved shape. Since this curved part prevents the locking link body 10 a of the locking link 10 from moving towards the back. Therefore, the curved part decides the position of the locking ring 10 . On the other hand, the quick connector 70 having a different structure as describe above (see FIGS. 3 and 4 ) that connects between the fuel supply pipe 53 and the injector 17 a , does not have a curve-shaped base 61 a of the male connector member 61 , the illustration of which is omitted. In the case above, the base 61 a does not decide the position of the locking ring 10 .
[0065] In such a case, it is desirable to establish a projection-shaped stopper 71 at the position corresponding to the base 61 a , for example, as shown in FIG. 4 .
[0066] As described so far, the present invention has been explained based on one embodiment, but the present invention is not limited to this example. For example, in the configuration above, the quick connector is applied to the pipe arrangement for the fuel system, but it is not limited to this example. This connector may also be applied to the pipe connection for water, oil, air, or the like.
[0067] In addition, in the above embodiment, the present invention is applied to an ATV vehicle, but it is not limited to this example. The present invention may be applied to a two-wheeled vehicle, three-wheeled vehicle, or the like.
[0068] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | A quick connector is capable of reducing wobbling due to vibrations, and even after the retaining member is reused repeatedly, sealing property can be maintained and wobbling can be made smaller. A quick connector is provided with, a female connector member, a male connector member which fits into the female connector via a sealing member, and a retaining member which exists in a circular space between these connector members, interposed between the inner periphery of the female connector member and the outer periphery of the male connector member to be engaged therewith, thereby preventing the male connector member from coming off in the connector central line direction, wherein, a locking ring having a first fitting part which fits between the inner periphery of the retaining member and the outer periphery of the male connector member is provided on the outer periphery of the male connector member. | 5 |
This application claims the benefit of U.S. Provisional Application No. 60/192,320, filed on Mar. 27, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the art of magnetic tunnel junction read heads, which sense magnetic fields in a magnetic recording medium. It finds particular application in conjunction with reading hard disk drives and will be described with particular reference thereto. However, it is to be appreciated that the invention will find application with other magnetic storage media. Further, it is to be appreciated that the invention will find application in other magnetic field detection devices as well as in other devices and environments.
2. Description of the Related Art
Magneto-resistive (MR) sensors based on anisotropic magneto-resistance (AMR) or a spin-valve (SV) effect are widely known and extensively used as read transducers to read magnetic recording media. Such MR sensors can probe the magnetic stray field coming out of transitions recorded on a recording medium by generating resistance changes in a reading portion formed of magnetic materials. AMR sensors have a low resistance change ratio or magneto-resistive ratio ΔR/R, typically from 1 to 3%, whereas SV sensors have a ΔR/R ranging from 2 to 7% for the same magnetic field excursion. SV heads showing such high sensitivity are able to achieve very high recording densities, that is, over several giga bits per square inch or Gbits/in 2 . Consequently, SV magnetic read are progressively supplanting AMR read heads.
In a basic SV sensor, two ferromagnetic layers are separated by a non-magnetic layer, an example of which is described in U.S. Pat. No. 5,159,513. An exchange or pinning layer of FeMn is further provided adjacent to one of the ferromagnetic layers. The exchange layer and the adjacent ferromagnetic layer are exchange-coupled so that the magnetization of the ferromagnetic layer is strongly pinned or fixed in one direction. The magnetization of the other ferromagnetic layer is free to rotate in response to a small external magnetic field. When the magnetizations of the ferromagnetic layers are changed from a parallel to an anti-parallel configuration, the sensor resistance increases yielding a relatively high MR ratio.
Recently, new MR sensors using tunneling magneto-resistance (TMR) have shown great promise for their application to ultra-high density recordings. These sensors, which are known as magnetic tunnel junction (MTJ) sensors or magneto-resistive tunnel junctions (MRTJ), came to the fore when large TMR was first observed at room temperature. See Moodera et al, “Large magneto resistance at room temperature in ferromagnetic thin film tunnel junctions,” Phys. Rev. Lett . v. 74, pp. 3273-3276 (1995). Such MTJs have achieved an MR ratio of over 12%.
As the demand for ultra-high density recording grows, MTJ sensors seem likely to replace SV sensors in the near future. However, before that can happen, a new MTJ head structure is needed that can maximize the TMR properties.
Like SV sensors, MTJ sensors basically consist of two ferromagnetic layers separated by a non-magnetic layer. One of the magnetic layers has its magnetization fixed along one direction, i.e., the pinned layer, while the other layer, i.e., free or sensing layer, is free to rotate in an external magnetic field.
However, unlike SV sensors, the non-magnetic layer in MTJ sensors is a thin insulating barrier or tunnel barrier layer. Further, unlike SV sensors, MTJ sensors operate in CPP (Current Perpendicular to the Plane) geometry, which means its sensing current flows in a thickness direction of a laminate film or orthogonal to the surfaces of the ferromagnetic layers.
The sense current flowing through the tunnel barrier layer is strongly dependent upon a spin-polarization state of the two ferromagnetic layers. When the sense current experiences the first ferromagnetic layer, the electrons are spin polarized. If the magnetizations of the two ferromagnetic layers are anti-parallel to each other, the probability of the electrons tunneling through the tunnel barrier is lowered, so that a high junction resistance R ap is obtained. On the other hand, if the magnetizations of the two ferromagnetic layers are parallel to each other, the probability of the electrons tunneling is increased and a high tunnel current and low junction resistance R p is obtained. In an intermediate state between the parallel and anti-parallel states, such as when the both ferromagnetic layers are perpendicular in magnetization to each other, a junction resistance R m between R ap and R p is obtained such that R ap <R m <R p . Using these symbols, the MR ratio may be defined as ΔR/R=(R ap −R p )/R p .
The relative magnetic direction orientation or angle of the two magnetic layers is affected by an external magnetic field such as the transitions in a magnetic recording medium. This affects the MTJ resistance and thus the voltage of the sensing current or output voltage. By detecting the change in resistance and thus voltage based on the change in relative magnetization angle, changes in an external magnetic field are detected. In this manner, MTJ sensors are able to read magnetic recording media.
One problem with MTJ sensors is an enlarged read gap. U.S. Pat. No. 5,729,410 discloses an example wherein a MTJ sensor or element is applied to a magnetic head structure. The MTJ sensor is sandwiched between two parallel electrical leads or electrodes, which are in turn sandwiched between first and second insulating gap layers of alumina or the like to form a read gap. A pair of magnetic shield layers are further formed to sandwich therebetween the first and second insulating gap layers. In this example, the read gap is enlarged at a sensing or head end surface, i.e., an ABS (Air Bearing Surface), which confronts a magnetic recording medium. Thus, a MTJ head of this design is handicapped for application to high-density recording. Moreover, the biasing efficiency of this structure is poor due to the separation between the free layer and the permanent magnets. If the permanent magnets are formed in an overlapping manner on the TMR film, a strong decrease of the TMR ratio is yet expected due to a large difference of the junction resistance in the regions below and in between the permanent magnets.
U.S. Pat. Nos. 5,898,547, 5,898,548 and 5,901,018 disclose other examples wherein a MTJ sensor is applied to a magnetic head structure. In these publications, technical improvements are mainly proposed for adaptation to ultrahigh density recordings. However, the demand for development of MTJ heads for ultrahigh density recording has surpassed these improvements and proposals for more advanced TMR magnetic heads are demanded.
Another problem is a trade-off between high TMR ratio and MTJ resistance. The TMR ratio is proportional to the spin polarization of the two ferromagnetic layers. A TMR ratio as high as 40% was achieved by choosing a preferable composition for the two ferromagnetic layers. See Parkin et aL, “Exchange-biased magnetic tunnel junctions and application to nonvolatile magnetic random access memory, ” J App. Phys ., v. 85, pp. 5828-5833 (Apr. 15, 1999). However, despite this large TMR ratio, the application of such MTJs in read heads was, up to now, prohibitory due to the large resistance of the junctions, resulting in a large shot noise V rms and a poor signal to noise ratio S/N. Shot noise V rms=( 2·e·I·Δf)½×R, where: e=1.6×10 −19 C; I=current; Δf=bandwidth; and R=junction resistance.
It is possible to reduce the MTJ's resistance-area product R·A or RA using a natural, in situ oxidation method. RA is a characteristic of an insulating barrier and contributes to junction resistance R through the equation R=R·A/junction area. Using a 7 Å or less Al layer that is properly oxidized, an RA as low as 15 Ω·μm 2 has been achieved. This remarkably low value together with the high TMR ratio make MTJs very attractive for application as read heads for very high recording densities.
However, yet another problem in MTJs is that the thin insulating barrier is very sensitive to one of the manufacturing processes called lapping. Lapping involves the definition of an air bearing surface (ABS) on the MTJ head. Because the insulating barrier is so thin, lapping can create electrical shorts between the two adjacent magnetic layers, rendering the sensor useless. Actual designs thus include a front flux guide to protect the barrier during lapping. U.S. Pat. No. 5,898,547 proposed a design wherein the flux guide is made from the sensing layer. Obviously this design avoids any magnetic interruption between the flux guide and the sensing layer, which improves the magnetic efficiency of the flux guide. However, the large TMR ratio requires CoFe material within the sensing layer, and such large magnetization is inappropriate to get the highest efficiency of the flux guide. Thus, the design makes a compromise between high TMR ratio and high flux guide efficiency to get the largest output.
Therefore, a goal of the present invention is a read head design wherein the TMR ratio is be maximized by choosing MTJ materials with the largest spin-polarization and wherein the flux guide efficiency is optimized using hybrid low-magnetization materials to achieve a large signal output.
Another goal of the present invention is to provide a design wherein the junction area is enlarged to keep reasonable dimensions for high recording density, while maintaining the S/N at a high value.
Another object of the present invention is to provide a MTJ head with a high biasing efficiency and no reduction in TMR ratio to ensure a high and stable head output for adaptation to ultra high-density recording.
BRIEF SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, an MTJ read head of the present invention comprises a magnetic tunnel junction read head having a sensing surface for sensing data magnetically recorded on a magnetic recording medium. The magnetic tunnel junction includes a tunnel barrier layer sandwiched between a ferromagnetic sensing layer and a ferromagnetic pinned layer. A ferromagnetic flux guide is magnetically coupled to the sensing layer. The flux guide extends to the sensing surface and has a magnetization lower than a magnetization of the sensing layer.
In a more limited aspect of the invention, the sensing layer is recessed from the sensing surface.
In another more limited aspect of the invention, the flux guide includes NiFeX where X is one or more of Ta, Nb, Cu, Cr, W, Al, Au, In, Ir, Mg, Rh, and Ru.
In yet another more limited aspect of the invention, the flux guide has a front portion and a back portion. The front portion has a width Ffw and extends generally along a length Fh from a front of the magnetic tunnel junction to the sensing surface. The back portion has a width Fbw and is adjacent the magnetic tunnel junction. Further, Ffw is less than a magnetic tunnel junction width Jw and Fbw is greater than Jw.
One advantage of the present invention is that the separate hybrid low magnetization flux guide greatly increases the output signal because the flux guide efficiency is improved. A high TMR ratio is maintained by the proper choice of materials involved in the sensing layer. Because the output signal is very high, the junction area can be significantly enlarged without degrading the S/N. This enables the design to function with very high recording densities beyond 100 Gbits/in 2 .
Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS AND TABLES
The invention may take form in various components and arrangements of components, and in various steps and arrangement of steps. The drawings are only for purposes of illustrating a preferred embodiment and are not to be construed as limiting the invention.
FIG. 1 is a perspective view of a first preferred embodiment of the MTJ read head of the present invention showing generally the main active elements of the active area, namely the MTJ (in dashed lines), the flux guide and the biasing means;
FIGS. 2, 3 , and 4 are vertical cross-sectional views through a center of an MTJ read head of the present invention in a plane parallel to the ABS illustrating a process of forming the MTJ read head structure of the first embodiment;
FIG. 5 shows the output voltage dependency on the front flux guide height Fh for various compositions of the flux guide;
FIG. 6 shows the output voltage dependency on the junction height Jh at constant sense current and constant bias voltage;
FIG. 7 is a perspective view of a second preferred embodiment showing an MTJ read head with a T-shaped flux guide;
FIG. 8 is a top view of the second preferred embodiment defining various dimensions of the flux guide and of the MTJ;
FIG. 9 shows the output voltage dependency on the junction width Jw at constant current and constant bias of the second preferred embodiment; and
FIG. 10 is a vertical cross section of the center of the second preferred embodiment perpendicular to the sensing surface, which shows the magnetic connection between the flux guide and the second shield.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, in a first preferred embodiment, a MTJ sensor or read head includes a hybrid, low-magnetization flux guide 10 contiguous with a multi-layer tunnel portion or MTJ 14 (shown in dashed lines), which is embedded in a bottom read head gap 18 . The MTJ exhibits a magneto-resistive spin tunnel effect. The MTJ comprises a ferromagnetic sensing or free layer 20 formed on one side of an insulating layer 30 , and a ferromagnetic pinned layer 40 formed on the other side. The pinned layer has a magnetization direction 50 , which is fixed by exchange coupling with an anti-ferromagnetic (AF) pinning or exchange layer 60 formed underneath. In an alternative embodiment, the pinned layer is a synthetic anti-ferromagnet. The whole MTJ head structure defines an ABS 70 , which confronts a magnetic recording medium (not shown) and which is orthogonal to the pinned layer magnetization.
The width of the flux guide in the plane of the ABS defines the track width of the MTJ read head. This is generally the same width as a string of sequential storage units or bits in a corresponding magnetic storage media such as a hard disk drive. The MTJ is shown with angled sides, which result from the manufacturing process described below. A flux guide height Fh is defined to be a distance between the ABS and a front end of the MTJ. A junction height Jh is defined to be a length of the MTJ in a direction orthogonal to the ABS. Because of the slightly angled sides of the MTJ, the area dimensions of the MTJ are defined to be the area dimensions of the insulating barrier.
In the first preferred embodiment, the sensing layer of the MTJ is a multi-layer comprising NiFe and CoFe ferromagnetic materials to obtain a large TMR ratio. Preferably, the thickness of the NiFe layer is greater than or equal to 10 Å and the thickness of the CoFe layer is greater than or equal to 15 Å and less than or equal to 40 Å.
The insulating layer is preferably made from a thin layer of Al-Ox, which is Al properly oxidized using a conventional, natural, in situ oxidation method. Alternatively, the insulating barrier may be formed of Al 2 O 3 , NiO, GdO, MgO, Ta 2 O 5 , MoO 2 , TiO 2 , WO 2 or the like. The thickness of the tunnel barrier layer 30 is desired to be as thin as possible for reducing the resistance of the element. However, if the thickness becomes too thin to cause pin holes, a leak current is generated, which is not preferable. In general, the thickness is set to about 5 Å to 20 Å.
The pinned layer comprises a sandwich of CoFe, Ru, and CoFe layers. The pinning layer is preferably of an AF material, such as PtMn, PdPtMn, IrMn, FeMn or NiMn. However, it is to be appreciated that the pinning layer is not limited to these AF materials and may even be ferromagnetic materials as long as it serves a pinning function. The bottom read head gap is formed of deposited aluminum oxide Al 2 O 3 .
In alternative embodiments, the ferromagnetic free layer and pinned layer are made with a wide variety of high spin polarization materials, such as Fe, Co, Ni, FeCo, NiFe, CoZrNb or FeCoNi to obtain a high TMR ratio. Further, each layer consists of a single layer of material or a laminate body having two or more layers.
In the first preferred embodiment, the separate flux guide is hybrid material of low magnetization materials such as alloy compounds of NiFeX, where X is one or more of Ta, Nb, Cu, Cr, W, Al, Au, In, Ir, Mg, Rh, Ru, and/or the like. The addition of element X reduces the NiFe magnetization. Generally, the flux guide materials are selected to have lower magnetization than the ferromagnetic material used for the contiguous ferromagnetic layer, which in this embodiment is the sensing layer. The flux guide is in magnetic contact or magnetically coupled or in ferromagnetic exchange with the sensing layer to insure a good exchange stiffness between the two layers, which is important to get a coherent rotation of the magnetizations of these layers in an external magnetic field. To achieve good magnetic contact, the sensing layer is pre-cleaned, the flux guide is sputter deposited onto the sensing layer, and then the guide is ion milled. The flux guide, having a width Fw, is generally rectangular-shaped and has a planar area or region wider than a planar region of the MTJ. Preferably, the MTJ height Jh is (0.8×Fw)≦Jh≦(3×Fw).
Permanent magnets 100 or biasing means having magnetization direction 110 are attached at lateral or opposite ends of the flux guide. Material making up the permanent magnets is deposited onto the bottom read head gap using conventional deposition methods. The material is then initialized or magnetized with a very strong magnetic field to form the permanent magnets.
The biasing means creates a single domain configuration both in the flux guide and in the sensing layer. The magnetization direction 110 is perpendicular to the pinned layer magnetization and parallel to the ABS. The flux guide, biasing means, and MTJ make up the active part of the MTJ read head.
With reference to FIGS. 2, 3 , and 4 , the process to form the MTJ read head of the first preferred embodiment is illustrated. Generally, conventional manufacturing methods are used such as photo-resist, ion milling, lift-off and sputtering techniques. Because these are known, an explanation of the details of the individual methods is omitted here.
With continuing reference to FIG. 2, a MTJ is formed on top of a bottom shield 150 . The shield acts as a substrate and an electrical lead to carry the sense current to the MTJ. The shield may be made of NiFe (Permalloy), Sendust, CoFe or CoFeNi.
In an alternative embodiment, the MTJ and flux guide design of FIG. 1 is reversed or flipped upside down. In this alternative embodiment, the flux guide is deposited onto a bottom gap followed by the free layer, the insulating layer, the pinned layer and pinning layer. This reversal merely creates an alternative structure that does not affect any of the physical characteristics of the MTJ read head.
In one example of the first preferred embodiment, the multi-layer MTJ comprises the following layers, from the bottom to the top:
Buffer layer: Ta 85 Å and NiFe 20 Å
Pinning layer: PtMn 300 Å
Pinned layer: CoFe 25 Å, Ru 9 Å, and CoFe 25 Å
Insulator barrier: Al—Ox 7 Å
Sensing layer: CoFe 15 Å and NiFe 30 Å
The pinned layer 40 is a synthetic AF film to minimize the magneto-static coupling acting on the sensing layer and the flux guide. Synthetic AF films are strongly required in MTJ read heads to control the output asymmetry because the sense current, flowing perpendicularly, is ineffective at counterbalancing the magneto-static coupling. The tunnel barrier 30 is fabricated from a 7 Å thick Al layer properly oxidized using a conventional in situ natural oxidation method. With this oxidation method, an RA as low as 30 Ω·μm 2 was achieved. The sensing layer 20 is a double layer of NiFe and CoFe. The CoFe thickness is not be smaller than 15 Å to insure a high spin-polarization but is not larger than 40 Å to keep low coercivity. The NiFe layer does not improve the spin-polarization but reduces the coercivity of the CoFe layer. A minimum of 10 Å NiFe is required to observe a significant decrease of the CoFe coercivity.
The MTJ is then patterned into a square using a resist mask and ion milling. Again, the MTJ is shown in FIGS. 2, 3 , and 4 with angled sides, which result from the ion milling process.
The sides of the MTJ are embedded in Al 2 O 3 to prevent electrical short of the insulating barrier. This Al 2 O 3 layer also defines the bottom gap 18 of the read head.
With reference to FIG. 3, after a soft cleaning process of the sensing layer surface to insure a good magnetic contact, the flux guide is sputter deposited on top of the sensing layer. The flux guide is made of a NiFeX alloy where X is more preferably Ta or Nb. The flux guide 10 is then patterned into a square, which is wider than the MTJ. Biasing means 100 are attached on lateral sides of the flux guide by a lift-off process.
With reference to FIG. 4, which shows a complete MTJ read head, a metal or top gap 160 is sputter deposited on the structure. A second or top shield 170 is then added to complete the head structure. The top gap 160 is metallic to insure an electrical contact between the MTJ and the top shield. This closes the electrical circuit for the sensing current from the bottom shield 150 to top shield 170 . The gaps are fixed by disk density, specifically, the length of each bit in a track. The bottom and top gaps allow the magnetic flux from the magnetic recording media to concentrate in the flux guide rather than leak into the shield.
Using the design of the first preferred embodiment, different materials were evaluated for the flux guide. Table 1 shows the output voltages and the signal to noise ratio S/N for the first embodiment (designed for 20 Gbits/in 2 ) for various flux guide compositions and various preferred flux guide heights Fh.
TABLE 1
Output voltage and S/N for various front
flux guide compositions and various flux guide heights Fh
Front flux guide height Fh
0.1 μm
0.2 μm
0.3 μm
Output
S/N
Output
S/N
Output
S/N
70 Å
3095 μV
24.2 dB
1856 μV
19.7 dB
1010 μV
14.4 dB
NiFeTa
40 Å
3325 μV
24.8 dB
2017 μV
20.4 dB
1090 μV
15.1 dB
NiFe
40 Å
5440 μV
29.1 dB
3098 μV
24.2 dB
1625 μV
18.6 dB
NiFeTa
40 Å
6170 μV
30.1 dB
3488 μV
25.2 dB
1823 μV
19.6 dB
NiFeNb
40 Å
2847 μV
23.4 dB
1293 μV
16.6 dB
547 μV
9.1 dB
NiFeTa
without
coup-
ling
Free as
1930 μV
20.1 dB
1192 μV
15.9 dB
729 μV
11.6 dB
FFG
In this evaluation, an MTJ design for reading a medium having a recorded density of 20 Gbits/in 2 was adopted. Thus, the following dimensions were used: distance of bottom shield to top shield 0.11 μm; MTJ area of 0.3×0.3 μm 2 ; flux guide area of 0.4×0.4 μm 2 ; Fh=0.1 μm; and biasing means of CoPt permanent magnets that are 300 Å thick. The MTJ had the same composition and dimensions as the MTJ in the first preferred embodiment. This yielded a TMR ratio of 27% TMR and RA=35 Ω·μm 2 .
All the MTJ heads were evaluated on the same disk (Mr·t=0.32 memu/cm 2 , Hc=4000 Oe), and with the same sense current of 0.3 mA. This current was chosen to give a low bias voltage of 120 mV, required for a long lifetime of MTJ heads. Looking at this table, it is clear that the flux guide made of materials with low magnetization, namely NiFeTa and NiFeNb, gave the highest output signal, i.e., >5.4 mV or 18 mV/μm TW for a 40 Å thick flux guide and Fh=0.1 μm, and the largest S/N.
If the magnetic contact between the sensing layer and the flux guide is lost, such as when the surface of the sensing layer is slightly oxidized, the output is strongly degraded because the magnetizations in the flux guide and the sensing layer are not rotating coherently. This effect is seen in the output differences between NiFeTa and NiFeTa without coupling, where decoupling is achieved by introducing an oxide layer between the free layer and the flux guide.
It is noted that an MTJ design wherein the sensing layer is used as flux guide produces the lowest output voltage. Further, the design yields such a poor S/N that it is even lower than the S/N for conventional spin-valve heads.
With reference to FIG. 5, the output signal is clearly dependent on Fh with respect to all of the flux guide materials tested. More specifically, the smaller Fh is, the greater the output signal is. Thus, it becomes apparent that flux guides made of low magnetization materials have a large potential for high recording density, especially if Fh can be reduce below 0.1 μm.
Indeed, the output of MTJ read heads using 40 Å NiFeTa as a flux guide is so high that one can afford to increase Jh to decrease the junction resistance. With reference to FIG. 6 and Table 2, the output voltage is shown to be dependent on Jh such that the smaller Jh, the greater the output signal. This applies for both constant current through and constant bias or voltage across the MTJ.
TABLE 2
Output and S/N for different Junction heights
Height Jh
Output
Output
(μm)
(I = 0.31 mA)
(V = 120 mV)
Rj (Ω)
S/N (dB)
0.3
5440 μV
5440 μV
389
29.08
0.4
3388 μV
4545 μV
292
28.65
0.5
2294 μV
3862 μV
233
28.12
0.6
1477 μV
2955 μV
194
26.46
More particularly, Table 2 shows the output voltages at constant current and constant bias, junction resistance Rj, and S/N for the first embodiment (designed for 20 Gbits/in2) with various junction heights Jh.
With continuing reference to Table 2, in the first column, the output for constant current is rapidly decreasing with height. However, for a constant bias voltage (120 mV), the decrease is more limited. As the noise associated with the junction resistance is also decreased, the S/N remains high even if Jh is doubled. Considering that a large junction area not only reduces the junction resistance and the associated shot noise but also pushes the limits of the lithography process to higher densities, a design wherein the junction width is wider than the track width TW has been evaluated.
With reference to FIG. 7, a second preferred embodiment of an MTJ read head A′ includes most notably a separate T-shaped flux guide 10 ′ having a rectangular front portion 200 and a rectangular rear portion 210 . Same or analogous elements with FIG. 1 have the same reference numerals but are distinguished with a prime.
With reference to FIG. 8, the front flux guide portion 200 forms a part of the ABS 70 ′. The front portion has a width Ffw at the ABS 70 ′. Thus, the track width TW=Ffw. The rear flux guide portion 210 has a width Fbw. Biasing means 100 ′ are contiguous with lateral ends of the rear flux guide portion.
Ffw is set smaller than the junction width Jw. With such a design the junction area can be enlarged, thus reducing its resistance and the associated shot noise, while the S/N is kept high. Ffw is reduced only between the ABS and the front end of the junction, i.e., generally over a distance Fh. At the rear, Fbw is set wider than the junction width Jw so that the upper surface of the sensing layer is still fully in contact with the flux guide. Having the rear flux guide portion greater in area than the junction area insures a good distribution of the magnetic flux over the junction area. Further, it keeps the biasing means sufficiently spaced from the sensing layer to avoid a strong bias field from the edges of the biasing means. This strong bias field is caused for example by permanent magnets and can reduce the active area.
The T-shaped flux guide is manufactured using a high-resolution negative resist and a double exposure of two bars or layers oriented at 90° and partially overlapped. It is to be appreciated that other manufacturing techniques may also be used to create the T-shaped flux guide.
Using this design, a set of MTJ heads were prepared having the following dimensions: Jh=0.3 μm; Fh=0.1 μm; and Ffw=0.3 μm. Jw was varied from 0.3 to 0.7 μm. Fbw, corresponding to the region that in port overlaps the sensing layer, was 0.1 μm wider than Jw. All the other dimensions were kept the same compared to the first embodiment. Thus, this head is also designed for a 20 Gbits/in 2 application. The results of the evaluation are in Table 3, which shows the output voltage at constant current and constant bias, junction resistance, and S/N for various Jw.
TABLE 3
Output and S/N for different junction widths.
Width Jh
Output
Output
(μm)
(I = 0.31 mA)
(V = 120 mV)
Rj (Ω)
S/N (dB)
0.3
5703 μV
5703 μV
389
29.5
0.4
4487 μV
5935 μV
292
31
0.5
2571 μV
4230 μV
233
28.9
0.6
2190 μV
4309 μV
194
29.8
0.7
1549 μV
3597 μV
167
28.6
With reference to FIG. 9, the output voltage is plotted for constant current and constant bias versus Jw. Although the signal decrease at constant sense current is exponential, the decrease at constant bias is more step-like. Thus, the decrease of the average magnetic flux in the junction can be counterbalanced by the gain of sense current. From Table 3, one can see that even for Jw=0.6 μm, i.e., 2×Ffw, the S/N is higher than the S/N when Jw=Ffw. Therefore, the T-shaped design allows the use of wide junctions without loss of S/N, which is very promising for very high recording densities. Preferably, the MTJ width Jw is defined by (0.8×Ffw)≦Jw≦(3.0×Ffw), and the MTJ height Jh is defined by (0.8×Ffw)≦Jh≦(3.0×Ffw).
With reference to FIG. 10, in a third preferred embodiment, the second preferred embodiment is modified so that a rear flux guide end 250 is connected to the top shield 170 ″. Same or analogous elements with FIG. 1 have the same reference numerals but are distinguished with a double prime. This design further improves the efficiency of the flux guide by decreasing or suppressing the magnetic charge on the back end of the flux guide. In other words, by contacting the flux guide with the top shield, the demagnetization field is reduced to zero. With this configuration, the flux decay along the flux guide height is further reduced and a higher output voltage is generated. Similarly, in an alternative embodiment, the rear end of the flux guide of the first preferred embodiment is also connected to the top shield.
For additional disclosure of various aspects of the present invention, U.S. patent application Ser. No. 09/517,580, which is entitled “Magneto-Resistive Tunnel Junction Head” is herein incorporated by reference. That application is directed to an MTJ read head with a particular structure of a ferromagnetic free layer for ultrahigh density recordings.
The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding this specification. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the claims or equivalents thereof. | The present invention relates to a magneto-resistive tunnel junction read head having a multi-layer tunnel junction composed of a tunnel barrier layer sandwiched between a ferromagnetic free layer and a ferromagnetic pinned layer. Contiguous with the free layer is a hybrid, low-magnetization, T-shaped flux guide having a rear flux guide portion and a more narrow front flux guide portion. The front flux guide portion constitutes a part of an ABS (Air Bearing Surface). The rear portion entirely covers and overlaps the tunnel junction. The hybrid flux guide has a lower magnetization -than the sensing layer due to the addition of magnetization reducing elements such as Ta or Nb. Using this design, a tunnel junction read head has improved read performance and achieves a high and stable head output for adaptation to ultrahigh density recording. | 6 |
BACKGROUND OF THE INVENTION
[0001] Radio frequency energy may be used to treat certain cardiac abnormalities, such as fibrillation, by ablating caridiac tissue. Radio frequency energy is delivered by RF generators in two phases: (i) the “ramp up” phase in which a relatively high amount of power is delivered to the ablating electrode until a desired set temperature is sensed by the thermocouple or thermistor, and (ii) the “regulation” phase in which power is still being delivered but regulated at a lower level to maintain the desired set temperature. This target temperature is predetermined by the operator, and is generally 50° to 55° C. for ablation of cardiac tissue.
[0002] Most RF generators have software modules which run simultaneously on portable computers during RF energy delivery to log the ablation episode. Typically, the parameters logged are sensed impedance, power delivered, as well as tissue temperature sensed by either thermistors or thermocouples. Currently, this information is typically used for post-procedural review.
[0003] The challenge in RF ablation of cardiac tissue is to create deep lesions in the cardiac tissue while avoiding coagulum formation. It follows that RF energy must be delivered efficiently into the tissue, and not delivered and lost into the blood medium. Current methods and systems are not adequate to assure that RF energy is delivered efficiently to cardiac tissue during an ablation procedure.
[0004] Prior studies in the delivery of RF energy have shown that when electrode-tissue contact is intermittent, the impedance value fluctuates and the power delivered also has to rapidly adapt in order to reach or maintain the target temperature. The rapid alternating impedance values therefore cause the output power waveform to also fluctuate rapidly. If the rise-time of the RF power waveform is sharp, and the noise modulated onto the RF source signal has high enough amplitude, it may be conducive for coagulum formation because it may undesirably approximate the coagulation waveform used by electro-surgical units. Therefore, there remains a need for systems and methods for performing RF ablation wherein effective contact with target cardiac tissue is assured to achieve deeper lesions and reduced coagulum formation.
[0005] The methods and systems of the current invention provide efficient delivery of radio frequency (RF) energy to cardiac tissue with an ablation catheter, thereby yielding consistently effective RF ablation procedures and improved patient outcomes.
SUMMARY OF THE INVENTION
[0006] The methods and systems of the current invention deliver RF energy to cardiac tissue simultaneously through a series of channels in a manner that is designed to minimize the risk of an ineffective ablation procedure due to coagulum formation. The methods and systems utilize an information processor and RF output controller to carefully control the rate and amount of RF energy delivered from an RF generator to the cardiac tissue being ablated to improve the effectiveness of an ablation procedure. The information processor and RF output controller assures that RF energy is increased gradually during the initial ramp-up phase. Furthermore, the information processor and RF output controller regulates delivery of RF energy during the ablation episode using information gathered from a series of sensors that are delivered to the site of ablation, preferably as part of an ablation catheter. The series of sensors include a series of temperature sensors and/or a multiplicity of current sensors. This feedback-control assures that proper temperature is maintained at the site of ablation and provides the ability to abort an ablation procedure if effective tissue contact is not established or maintained throughout the ablation procedure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as the preferred mode of use, further objectives and advantages thereof, is best understood by reference to the following detailed description of the embodiments in conjunction with the accompanying drawings and Appendix, wherein:
[0008] [0008]FIGS. 1A AND 1B are schematic diagrams of certain embodiments of the information processor and RF output controller and system of the current invention (FIG. 1A), and user interface (FIG. 1B) for the information processor and RF output controller.
[0009] FIGS. 2 A-B show catheter arrangements for efficient ablation;
[0010] [0010]FIGS. 3 and 4 show schematic block diagrams of an information processor and RF output controller in accordance with the invention, for regulating delivery of RF energy to cardiac tissue through an ablation catheter;
[0011] [0011]FIGS. 5A and 5B provide flow diagrams for the temperature measurements, and FIG. 5C is a block diagram illustrating real time analog computation of voltage impedance and power;
[0012] [0012]FIG. 6 shows a schematic diagram of temperature regulation circuitry used to regulate RF energy based on temperature readings.
[0013] [0013]FIG. 7 is a block diagram showing the regulation of delivery of RF energy by an information processor and RF output controller according to one embodiment of the current invention that regulates current delivered to each ablation electrode of a series of ablation electrodes, separately using digital logic.
[0014] [0014]FIG. 8 shows a record of a typical ablation episode using the methods and procedures of the current invention; and
[0015] [0015]FIG. 9 is a graph of logistic function with estimated probability of coagulum as the Dependent Variable, and C.I. as the Predictor Variable. FIGS. 10A and 10B show representative scattergrams of coagulum index values from two RF ablation patient cases. FIG. 10A shows results from a patient study when gradual power delivery was not applied and maximum power was set at 50 W. FIG. 10B shows results from a patient study using systems and methods according to the current invention where gradual power delivery was applied for each ablation episode and maximum power of the RF generator was set at 30 W.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] The methods and systems of the current invention utilize a novel information processor and RF output controller, also called a multi-channel RF ablation interface herein, to regulate delivery of radio frequency (RF) energy from an RF generator, also called an RF energy source herein, to cardiac tissue via an electrical coupling connected to a series of ablation electrodes of an ablation catheter. The information processor and RF output controller assures that energy is delivered in a gradually increasing manner during an initial ramp-up phase to an ablation temperature set point, and at a rate thereafter that is feedback-regulated to maintain the set-point temperature of the cardiac tissue at the site of ablation. Preferably, the temperature set point is selectable by a user. The delivery of energy is also preferably feedback-regulated by other parameters such as impedance, current, and/or power delivered to the ablation catheter to assure that effective contact between the ablation electrode and the cardiac tissue is maintained.
[0017] The information processor and RF output controller of the current invention are capable of delivering energy to each electrode of the series of ablation electrodes independently. In certain preferred embodiments, described herein, the information processor and RF output controller uses analog methods for information processing and pulsewidth modulation for RF energy control.
[0018] In preferred embodiments, the information processor and RF output controller is capable of delivering RF energy to the electrodes of the series of electrodes in any order or combination using methods described herein. Preferably, a user can select the electrode, or combination of electrodes, to which the information processor and RF output controller will deliver energy.
[0019] As shown in FIG. 1A, the described information processor and RF output controller 100 , also referred to herein as a multi-channel RF ablation interface, is intended to make cardiac lesions in the human heart in conjunction with commercially available radio-frequency (RF) lesion generators (RF generators) 150 and ablation catheters 160 , such as those manufactured by Cardima. The interface regulates RF energy delivery from the RF generator 150 to the ablation catheter 160 by temperature feedback using readings of thermocouple sensors 162 embedded in the catheters 160 , as well as by other parameters such as impedance and differential impedance. Electrical communication between the information processor and RF output controller and the catheter occurs via an electrical coupling 170 . The feedback regulation functions to maintain the electrode temperature near the preset temperature value, and to assure that effective contact between ablation electrodes 164 and cardiac tissue has been maintained for effective transmission of energy from the electrodes 164 to the cardiac tissue.
[0020] The general design features of the multi-channel RF ablation interface (i.e. the information processor and RF output controller) of the current invention include an operating RF frequency range of about 470 to about 510 kHz; multiple, preferably eight (8), regulated electrode channels; maximum power RF energy input of about 100 watts; maximum power RF energy output for each channel of 30 Watts; and a function that provides gradually power delivery at start-up. As described below, preferably the power for each channel is typically set at about 25 to 35 watts, most preferably about 30 watts. The information processor and RF output controller is typically capable of receiving real-time temperature monitoring information from sensors 162 on the ablation catheter 160 , and compares this information with the user defined set temperature. This temperature information is used to control the titration of RF energy to reach and maintain the set temperature, or to shut off RF energy delivery if a certain over-temperature cutoff is reached. The information processor and RF output controller also calculates real-time impedance and output power based on measurements sensed from the circuitry, then compares this calculated information to user set limits, wherein if a limit is exceeded, delivery of energy is terminated. Preferably the information processor and RF output controller 100 is capable of receiving and processing this information for each output channel of the circuitry. The information processor and RF output controller may use analog or digital methods for receiving and processing monitoring information from the sensors. In a preferred embodiment real-time analog data acquisition and computation methods are used.
[0021] The information processor and RF output controller and/or the RF source has the ability to deliver RF energy in a gradual manner when energy delivery is initiated. That is, either in a manual, or preferably an automated manner, upon initiation of delivery of RF energy to an ablation electrode, power is initiated at a level that is below the maximum power level used to attain a temperature set point for the cardiac tissue being ablated. Power is then gradually increased over a duration of about 8 to 15 seconds, preferably 10 seconds, typically until it reaches the maximum power. For example, but not intended to be limiting, when using the Radionics RFG-3E generator in the manual mode, power may be commenced with a setting of 10 watts, and then gradually increased within 10 seconds by adjusting the power knob on the RF generator to reach a set temperature of 50° C. while not overshooting a maximum of 30 watts, all the while maintaining total RF delivery time at 60 seconds. Rather than a manually controlled mode, the preferred information processor and RF output controller and RF output controller of the current invention, as described below in more detail, gradually increases power automatically upon initiation of RF energy delivery.
[0022] As shown in FIG. 1B, the information processor and multichannel simultaneous RF output controller typically contains a user interface containing a series of displays 105 and 110 , and adjustment knobs 115 , 120 , 125 , 130 , 135 to facilitate monitoring and control of the parameters described above. For example, the user interface may contain a display of parameter values 105 , and may preferably contain a separate thermocouple digital display 110 .
[0023] The user interface typically contains a series of adjustment knobs 115 , 120 , 125 , 130 , 135 to facilitate setting values for the parameters described above. For example, the information processor and RF output controller typically includes an ablation temperature set point control 115 and over-temperature set point control 120 . Typically the ablation temperature set point control 115 has a range of from about 50° C. to about 70° C., and the over-temperature set point control 120 has a range from about 55° C. to about 75° C. Additionally, the information processor and RF output controller preferably can determine impedance and differential impedance, typically measures power output and includes a power limit adjustment knob 125 . Preferably, the information processor and RF output controller has an impedance limit control 130 which typically can be set in the range from about 50 to about 1000 Ohms. Additionally, the information processor and RF output controller preferably has a differential impedance set point control 135 from 10 to 300 Ohms.
[0024] Finally, the information processor and RF output controller user interface may contain a fault status indicator 140 which may project any type of signal detectable by a user if the information processor and RF output controller detects a parameter value that exceeds a preset limit. For example, the fault status indicator may be triggered if the temperature of the cardiac tissue exceeds a maximum temperature set by the user. The fault status indicator may project a visual or auditory signals. In certain preferred embodiments, the user interface includes a reset switch which resets the fault status indicator.
[0025] The user interface on the information processor and RF output controller may have one or more of the following additional features, as described in more detail in the specific embodiment disclosed below:
[0026] 1. an ablate/pace mode select switch to switch between ablation and electro-cardiogram recording modes;
[0027] 2. ablate, RF active and pace indicator LEDs;
[0028] 3. a bipolar pacing stimulator selector switch;
[0029] 4. a parameter display pushbutton switch;
[0030] 5. an illuminated on/off electrodes select switch; and
[0031] 6. a real-time parameter data collection for post processing and data analysis in commercial software programs such as, but not limited to, LabView and Excel formats.
[0032] As mentioned above, the information processor and RF output controller of the current invention regulates delivery of RF energy from an RF energy source through multiple channels simultaneously to cardiac tissue. The primary functional building block of all radio frequency (RF) energy sources developed for tissue ablation is an electronic circuit called an oscillator which generates sinusoidal waveforms at particular operating frequencies. This waveform is consequently amplified to deliver the required wattage required for tissue ablation. The operating frequency of this RF oscillator typically is within the range of 470 to 510 kHz. The quality of the oscillator and ancillary electronics design impinges on the stability of the resulting operating frequency. Hence, this operating frequency may “drift” slightly if the oscillator design is unstable. Typically, this frequency jitter has imperceptible influence on the resulting tissue lesion. However, certain RF oscillators or associated electronics systems generate and deliver a skewed or distorted sine wave signal that has spurious noise spikes and/or harmonics riding on top of it. Such “noisy” and skewed RF waveforms may result in undesirable noise artifacts may have the potential of promoting coagulum formation if they are present during the ablation process. Therefore, it is desirable for the current invention to use an RF source which produces a relatively pure and stable sine wave, preferably as pure and stable a sine wave as possible.
[0033] As described above, the information processor and RF output controller is connected to and regulates RF energy delivered to multiple electrodes arranged in various configurations at the distal end of a catheter. In catheter ablation, electrodes of the catheter deliver the RF current into biological tissue. This RF energy in turn heats the tissue by causing ionic friction within the tissue and fluid medium encompassed by the electric field. When monitored, this temperature rise caused by the conversion of electrical to thermal energy can be used as a guide in RF catheter ablation. Its measurement is facilitated by the placement of thermal sensors, either thermocouples or thermistors, underneath or juxtaposed with the ablative electrodes. Not only can the sensed temperature be used to ascertain the quality of electrode-tissue contact and predict lesion size, it can also be utilized by the RF generator as a feedback signal to automatically regulate the output power to arrive at or maintain a temperature set-point predetermined by the end-user.
[0034] Many ablation catheters are known in the art and can be used with the systems and methods of the current invention. Typically, catheters for use with the current invention have multiple electrodes and thermal sensors in close proximity to these electrodes, as discussed above. Furthermore, preferred catheters allow relatively higher electrode current densities which allow lower maximum RF generator power settings, such that effective ablation can be performed at 35 W, and more preferably 30 W, rather than 50 W.
[0035] An example of a preferred catheter (i.e., the CARDIMA Revelation™ TX 3.7 Fr catheter) for use in the current invention is illustrated in FIGS. 2 A- 2 B. The catheter was developed for right atrial linear MAZE ablation, and has eight electrodes with thermocouples located in between the electrodes, to accurately sense localized tissue temperature at the ablation site. This preferred catheter has eight 6 mm coil electrodes with 2 mm inter-electrode spacing, and 8 thermocouples located proximal to each electrode in the inter-electrode spaces. A 9 Fr steerable guiding catheter called the Naviport™ may be used in conjunction with this catheter to aid in placement. Experience with the 3.7 Fr REVELATION Tx microcatheter has shown that it is successful in creating transmural lesions narrower and with smaller surface area than those created by standard 8 Fr ablation catheters.
[0036] In order to switch between each of the multiple electrodes and their corresponding thermocouples or thermistors, manual switchboxes interfacing multi-electrode catheters to single-channel RF generators, as well as automatic sequencing multi-channel RF energy generators have been developed and are now available in the marketplace. These switchboxes and multi-channel RF generators deliver RF energy to these electrodes in a consecutive, sequential fashion. In addition, there are also newer, higher power (e.g., 150W) RF generators which deliver RF energy simultaneously to multiple electrodes. These latter systems differ in design by how RF energy “is split” among the various electrode channels. This present invention presents a multichannel RF ablation system which uses pulse width modulation to govern the amount of RF energy being delivered at each channel, incorporating temperature feedback information per channel as well as from neighboring channels.
[0037] With these general features of a system for the delivery of RF energy to cardiac tissue according to the present invention, a specific embodiment is diagrammatically illustrated in FIGS. 3 and 4. The described embodiment provides a specific multi-channel RF ablation system with the general features illustrated in FIGS. 1A and 1B. The multichannel information processor and RF energy controller provides up to eight channels (switch selectable) of precise RF energy to the catheter's electrodes as well as displays the tissue temperature and impedance in real time. Measurement of the RF power delivered to the tissue, RF current, and RF voltage, as well as the differential impedance for each of the ablation elements, is also provided. All signals are available for computer monitoring or optionally displayed via front panel digital meters. The system incorporates a medical grade power supply approved by the international safety agencies. This power supply can be used for various line voltages and frequencies without any modification. The system is designed to handle up to 100 watts of input power RF energy. Utilizing an analog computer unit (ACU), the system continuously monitors and adjusts the precise RF energy delivered to each electrode.
[0038] The following are features of the pulse width modulation implementation for the system: (1) soft start power-on operation; (2) compensation for the lag in thermocouple response time; and (3) PWM synchronization for all eight channels.
[0039] Over-temperature detection is provided for each channel of the system. RF energy is latched off for the entire system if an over-temperature condition is detected. Operation is resumed by power cycling or pushbutton reset. Open thermocouple detection inhibits operation of only the faulty channel. Operation is resumed automatically when the fault is cleared. The system is designed to comply with the requirements and standards of international electrical safety codes. It utilizes isolated circuits for all patient connections to insure patient safety even with failed components. This applies to both the thermocouple amplifiers, and the RF output circuitry. The over-temperature cutoff limit is provided to cut off all power delivered to the catheter in the event that any thermocouple reaches a preset over-temperature limit. Adjustment range for this function is from 55° C. to 75° C.
[0040] A front panel control and display unit is provided which allows a user to set a number of parameters. For example, the front panel control and display can be used to set the maximum power value sent to any one electrode (Adjustment range: 1-30 watts). The impedance cutoff circuitry monitors each channel individually and will cause the power delivery to be interrupted from a given electrode when that electrode's impedance rises above a preset limit. The front panel control and display (one for the entire unit) provide a control button or knob for setting the impedance cutoff limit (Adjustment range: 50-1000 Ohms). The differential impedance cutoff circuitry monitors each channel individually and will interrupt power delivered to a given electrode if that electrode's impedance rises by a preset differential (above the lowest value during a given ablation run). The front panel control and display provides a knob for setting the differential impedance cutoff limit (Adjustment range: 10-200 Ohms). In order to prevent an RF generator trip-out due to low impedance (as can occur when several electrodes are running in parallel simultaneously), an active impedance network (dummy loads) are placed between the RF generator and the ablation circuitry.
[0041] A mode switch (ablate/pace) is provided for switching between ablation and electrocardiogram recording modes, as well as pace threshold determination mode. Appropriate filtering is designed to allow recording of electrocardiogram during ablation or pacing modes. Modes of Operation:
[0042] (Mode 1) Used for catheters that utilize thermocouples between electrodes (e.g., thermocouple 1 is proximal to thermocouple 2). The system will monitor temperature on both sides of each electrode and regulate the temperature based upon the higher temperature, except for the most distal electrode, which has only one nearest thermocouple.
[0043] (Mode 2) Used for catheters utilizing thermocouples either under or soldered directly onto each electrode.
[0044] The channel card functional block diagram (FIGS. 3 and 4) of the system 10 provide thermocouple inputs and patient isolation 12 , pulse width modulator 14 , power output RF control 16 , analog computer and parameter measurement 18 , impedance and differential impedance 20 , fault latch control 22 , and fault status 28 .
[0045] The common mode input filter is designed to handle high common mode of RF energy level on the thermocouples. The isolation circuits, both the power supply and the thermocouple amplifiers, are designed to isolate the patient from the main power source circuitry by 2500 volts.
[0046] The pulse width modulator (PWM) 14 regulates the RF energy by comparing the delivered RF power (computed by the analog computer) to the preset value (PLIMIT). It also provides soft start for each channel card as well as synchronization circuitry for all eight channels. The soft start is a safety feature active at power on that gradually ramps up the voltage to prevent spikes on the electrodes.
[0047] As shown diagrammatically in FIGS. 5 A-B, the amount of energy delivered to the RF coupling transformer is directly proportional to the pulse width generated by the PWM circuitry based on the temperature feed back from the catheter's thermocouple. In the preferred example of an ablation catheter for the current invention described above, each channel has a corresponding thermocouple (T/C) sensor which provides temperature feedback information at the tissue site immediately proximal to the electrode delivering RF energy. The RF output for each electrode is modulated by a PWM chip on the channel card. The commercially available PWM device used is the Unitrode High Speed PWM Controller UC3823, or the equivalent chip made by MicroLinear, ML4823. Temperature input signals sensed from neighboring T/C's are used to control the pulse-width modulator (PWM) outputs. The lower the input voltage corresponding to an input temperature, the longer the “on time” duration. Conversely, the higher the input voltage corresponding to a sensed input temperature, the shorter the “on time” duration.
[0048] The temperature regulation circuitry of this specific example is shown in more detail in FIG. 6. As mentioned above, each electrode 164 has a corresponding thermocouple sensor 162 that provides temperature feedback information at the tissue site immediately proximal to the electrode delivering the RF energy. Each electrode's RF output is controlled by a PWM circuit 180 located on each channel card. Temperature input signals sensed from neighboring thermocouples that are electronically subtracted from each other to form a new pulse width that will control the amount of RF energy output. For example, FIG. 6 illustrates the monitoring of both sides of electrode #5 and the resulting differential PWM that will control the RF circuitry for this electrode. As illustrated, digital logic, herein NAND gate 185 is employed with inputs set by temperature thresholds taken from thermocouples adjacent to the electrodes.
[0049] Safety features that isolate the external RF generator (coupling transformers) from the power source are implemented both on the channel card as well as common electronics board.
[0050] The voltage, current, impedance, and output power are calculated by the analog computer unit (ACU) and the associated high precision RMS to DC converter circuitry. The information generated by the ACU is crucial to the precise control and stability of the system. This provides real-time monitoring of the catheter's parameters and stabilizes the preset temperature for a constant stream of energy in order to create a clean and accurate lesion.
[0051] As shown diagrammatically in FIGS. 5 A-B, this interface provides an impedance and delta impedance cutoff for each channel individually. This will cause the power delivery to be interrupted from a given electrode when that electrode's impedance rises above a preset limit.
[0052] Over temperature, open thermocouple, high impedance, and high delta impedance detection circuitry are implemented into the design of the preferred example of an information processor and RF output controller (i.e. the IntelliTemp system) described herein. System shutdown occurs for over temperature detection on any channel. Open thermocouple will inhibit operation on the affected channel only, normal operation proceeds on remaining channels.
[0053] The following parameters are used for real time analog computation of voltage impedance and power according to the specific example of an information processor and RF output controller described above:
[0054] Input parameters:
[0055] Sensed AC Voltage, V in , via secondary side of the input transformer.
[0056] Sensed AC Current, I in , mA, via precision non-inductive resistor and associated circuitry.
[0057] Output parameters:
[0058] Computed RMS Voltage, V out , 100 mV/RMS representing 1 Volt, V.
[0059] Converted RMS Current, V out , 10 mV/RMS representing 1 milliampere, mA.
[0060] Computed Impedance, Z out , 1 mV/RMS representing 1 ohm, Ω.
[0061] Computed RMS Power, P out , 100 mV/RMS representing 1 Watt, W.
[0062] Introduction:
[0063] The specific example of the information processor and RF output controller illustrated in FIGS. 3 - 7 does not rely on digital circuitry (e.g., analog-to-digital (AID) converters, digital latches, registers, and a microprocessor) to determine sensed voltage, impedance, and power. Instead, it utilizes analog methods to provide real-time computation of RMS output, voltage, current, impedance and power.
[0064] The building blocks for the real-time analog computer are illustrated in FIG. 5C and described in the following paragraphs.
[0065] 1. The primary building block for this analog computation circuitry is the Analog Devices AD538 Real-Time Analog Computation Unit (ACU) which provides precision analog multiplication, division, and exponentiation. The first two mathematical operations are used, as follows:
[0066] The ACU has this transfer function:
V OUT,ACU =V y (V z /V x )
[0067] It should be noted that this V OUT,ACU is not the overall V OUT of the analog computation system; it is merely the output of the AD538 device used. V z is a DC value that is an output parameter from the second set of building blocks mentioned below, the RMS-to-DC Converter. This DC value represents the RMS voltage (V) of the RF energy being delivered at the electrode. Similarly, V x is a DC value which has been converted from the RMS current (mA), of the RF energy being delivered at the electrode. This device also permits a scaling factor, V y , to be multiplied into the output transfer function. This scaling factor is set at a value of 0.1, since the ratio of the primary to secondary coils of the input transformer is 10. Since V z represents voltage, and V x represents current, therefore V OUT,ACU represents the computed real-time impedance Ω.
[0068] 2. The secondary building blocks are two Analog Devices AD637 High Precision Wide-Band RMS-to-DC Converters, which serve to compute the true RMS value of an incoming AC waveform, and represent this RMS value as an equivalent DC output voltage. The outputs of these units are fed as input parameters into the ACU discussed above, which also supplies a true RMS value of a signal that may be more useful than an average rectified signal since it relates directly to the power of the input signal.
[0069] 3. The final building block is the Analog Device AD734 4-Quadrant Multiplier/Divider, which serves to multiply the DC value representing RMS Voltage, with the DC value representing RMS Current, to supply the product of these two terms, which is equivalent to Output Power, since P out =V out I out (W, Watts).
[0070] 4. The outputs of V out , I out , Z out , and P out , are hence all calculated in real-time.
[0071] RF output per channel is governed by three inputs into a NAND gate (Motorola part number MC74HC10A):
[0072] i. The “on time” of the pulse-width modulator for that particular channel.
[0073] ii. The “on time” of the pulse-width modulator for the channel immediately proximal to the above-said channel.
[0074] iii. Power Limit Set-Point that is common for all channels. This is manually set with a control knob on the instrumentation front panel.
[0075] As an example, the functional schematic of the interaction between Channel 3 input and Channel 2 output in determining Channel 3 output is shown in FIG. 7, where in the timing diagram of the Channel 3 electrode output (lower right corner) there is a slight propagation delay.
[0076] The PWM duty cycle is governed by an oscillator that is set by an oscillating frequency determined by a resistive and a capacitive component. In the present embodiment, this frequency is set at 1.7 kHz. However, if the sensitivity of the feedback-response circuit needs to be “slowed down” to increase heat build-up in the tissue, this frequency can be decreased.
[0077] [0077]FIG. 8 shows a typical ablation episode using the specific embodiment of the invention described above. Contact force is a parameter that has been measured experimentally in an in vitro setting to determine the quality of electrode-tissue contact; it has a high correlation (up to 97%) with temperature rise. Thus, when there is excellent electrode-tissue contact, there is a regular flow of RF energy transmitted into the tissue that is converted into heat energy. When this condition exists, the monitored tissue impedance and voltage is relatively constant. Therefore, the measured tissue impedance is another key parameter, because it is an indicator of electrode-tissue contact.
[0078] As described above, the information processor and RF output controller of the current invention, as well as the systems and methods of the current invention, are designed to maximize the efficacy of an ablation procedure by minimizing coagulum formation. Not to be limited by theory, these information processor and RF output controllers, systems, and methods take advantage of the following considerations. When tissue contact is good and stable, the impedance is relatively low and constant. As a result, less RF energy is required to reach the desired set temperature, with a shorter “ramp up” time and a lower wattage required to maintain the set temperature. The risk of coagulum formation is low because RF energy is effectively transmitted into the tissue, and heat is generated within the tissue rather than at the blood layer.
[0079] Conversely, when electrode-tissue contact is intermittent, the impedance value fluctuates and the power delivered also has to adapt rapidly in order to reach or maintain set temperature. This fluctuating waveform may be conducive for coagulum formation because the rapid back and forth switching between high and low impedance causes the output power waveform to approximates the coagulation waveform used in electrosurgery.
[0080] When electrode-tissue contact is marginal or poor, impedance can rise rapidly thereby requiring more RF energy to be delivered in a fast response to achieve the same set temperature. In this last scenario, because of poor electrode-tissue contact, there is a high probability that RF energy is lost into the blood layer surrounding the electrode, thus heating the blood rather than tissue and fostering coagulum formation. As coagulum forms on the electrode, impedance rises even more, hence bringing about a vicious cycle of climbing wafts and escalating thrombus formation. Hence, one has to terminate the power delivery immediately when there is a sudden impedance rise, and the catheter should be withdrawn at this point to clean coagulum off the electrodes.
[0081] The following example describes and illustrates the methods, systems, and devices of the invention. The example is intended to be merely illustrative of the present invention, and not limiting thereof in either scope or spirit. Unless indicated otherwise, all percentages and ratios are by weight. Those skilled in the art will readily understand that variations of the materials, conditions, and processes described in these examples can be used. All references cited herein are incorporated by reference.
EXAMPLE
[0082] A study was performed to analyze factors that affect coagulation formation during cardiac ablation, and to set parameters to minimize coagulation formation during this procedure. More specifically, the study was performed, at least in part, to analyze the rate of RF power delivery through ablation catheter electrodes with respect to target temperature set-points, and to determine its correspondence to coagulum formation.
[0083] This study was based on RF ablation data from 398 independent ablation episodes derived from 15 patient cases randomly picked from Phase II of the CARDIMA REVELATION™ Tx U.S. multicenter clinical trials. Patient entry criteria were symptomatic paroxysmal atrial fibrillation (PAF), refractory to at least 2 anti-arrhythmic drugs, with 3 PAF episodes within the 30 day baseline observation period. In this multicenter clinical protocol, the use of anti-coagulation agents followed these guidelines for all patients receiving RF ablation: Coumadin OK was discontinued three (3) days prior to the procedure and low molecular weight heparin was administered the day preceding the procedure. At the time of the procedure, the international normalization ratio (INR) was checked to be<1.8, and a baseline activated clotting time (ACT) value was obtained. An initial bolus of intravenous heparin was administered, and continuously administered throughout the procedure to maintain an ACT of approximately 200 to 300 seconds. The ACT measurements were taken at 30 minute intervals until therapeutic levels were achieved, then every 60 minutes for the duration of the procedure. Heparin administration was adjusted according to the ACT values.
[0084] RF ablation procedures were performed using the REVELATION Tx (CARDIMA, Fremont, Calif., U.S.A.) Microcatheter. This microcatheter has eight 6 mm coil electrodes with 2 mm spacing, and eight inter-electrode thermocouples. A 9 Fr CARDIMA NAVIPORT™ steerable guiding catheter was used in conjunction with the microcatheter to aid in placement. If the target temperature was not reached, the duration to reach the maximal recorded temperature closest to the target temperature was used instead. The RFG-3E RF generator (Radionics, Burlington, Mass., U.S.A.) was the RF source used for all procedures.
[0085] Software running on a computer connected to this generator was used to record the time for attaining a pre-determined target temperature, as well as the RF power and current at that time, for each RF energy application. Measurements taken included the duration time (seconds), for attaining a pre-determined temperature set-point (i.e., 50° or 55° C.), and the power (watts) at that time. This was carried out for each RF energy delivery episode corresponding to each electrode. If the set-temperature was not reached, the duration to reach the maximal recorded temperature closest to the set-temperature was used instead. After each linear ablation trajectory, the catheter was withdrawn from the steerable guiding sheath, and each electrode was visually inspected. The presence or absence of coagulum was noted on clinical data sheets, thereby providing a record for analysis with the RF delivery parameters,(i.e. power, current, and duration to reach target temperature) that were logged automatically by software.
[0086] Based on the study described above, a mathematical model was used to calculate a value, the Coagulum Index, that provides insight into the likelihood of coagulum formation during an ablation procedure, and that is useful in setting parameters for an ablation procedure to minimize the potential for coagulum formation. From this model, Coagulum Index was defined:
[0087] Coagulum Index=(W/t)/I 2
[0088] Power=W (wafts)
[0089] Current=I (amperes)
[0090] Duration to reach Set Temperature=t (seconds)
[0091] The term on the right-hand-side of the equation, (W/t), is the slope or gradient of the power curve measured from the start of the ablation episode (baseline) to the time that the target temperature (i.e. set point temperature) or maximum temperature is first reached in an ablation episode. The derivation of the Coagulum Index, which has no physical units, is included in Appendix A.
[0092] Many dose-response relationships have been found to follow a logistic sigmoidal curve. Hence, the estimated probability of coagulum occurring, P(coag), is modeled statistically by a logistic model described by Equation 1 below, where the logit risk of coagulum is the dependant variable and the coagulum index (C.I.) is the independent or predictive variable.
P ( coag ) = α + β ( C . I . ) 1 + α + β ( C . I . )
α = - 5.2932
β = 0.3803 Equation 1
[0093] [0093]FIG. 9 shows the graph of this logistic model. With this model, a threshold value for coagulum index (C.I.) can be found to indicate a high probability of coagulum occurring.
[0094] In a series of 398 ablation episodes from a total of 15 patient studies in the clinical studies described in this Example, it was found that the logistic model of risk of coagulum demonstrated a significant fit between Coagulum Index and the estimated percentage probability of coagulum occurring (p<0.001). Table I summarizes the finding that the estimated probability of coagulum formation increases significantly when Coagulum Index increases. This analysis revealed a clear correspondence between Coagulum Index and coagulum formation. Furthermore, a distinct threshold of Coagulum Index greater than or equal to 12 was established, beyond which coagulum formation is expected. Results of this study showed that coagulum could be reduced if the slope (W/t) was gentle. This was accomplished by gradually increasing the power delivered from the RF generator, as opposed to “cranking up the watts” at the very start of an ablation episode.
TABLE I C.I. 4 8 12 16 20 24 P(coag) % 2 10 32 69 91 98
[0095] [0095]FIGS. 10A and 10B show representative scattergrams of Coagulum Index values from two RF ablation patient cases. This data supports the conclusion that the derived Coagulum Index value has pertinence and value in suggesting coagulum formation. The example depicted in FIG. 10B, with Coagulum Index values less than 12, showed no coagulum formation. On the other hand, coagulum was observed in many of the energy applications of FIG. 10A, especially for those having a Coagulum Index greater than 12. For the energy applications in FIG. 10B, lower Coagulum Indexes were obtained by gradually increasing power, in contrast to an immediate increase in power levels which was used for the energy applications shown FIG. 10A. Furthermore, the maximum power setting was reduced from 50 to 30 watts in FIG. 10B.
[0096] The clinical effectiveness was analyzed for linear ablation procedures where coagulation formation was absent. During Phase I, power delivery was not controlled in a gradual manner for each ablation episode and maximum power was set at 50W. During Phase II, ablation was performed using a gradual power delivery (as described below) and maximum power was kept below 35W. As summarized in Table II, after 6 months AF episodes were reduced in Phase II patient populations. In fact, the number of patients experiencing a greater than 50% reduction in AF episodes almost doubled when using the gradual power delivery and lower maximum power for each ablation episode. A significant increase was also observed in the number of patients that no longer had any AF episodes (100% reduction), from 30% in Phase I to 53% in Phase II.
TABLE II % Reduction of AF Episodes Phase I Phase II after 6 months (N = 10) (N = 17) >50% reduction 4/10 Patients 13/17 patients (40%) (77%) 100% reduction (no AF 3/10 Patients 9/17 patients Episodes) (30%) (53%)
[0097] Thus, it appears that one mechanism for mitigating coagulum formation is to deliver RF power in such a way that the rise time of the power, and hence temperature curve, is more gradual and consistent. For example, when using the Radionics RFG-3E generator, with a set maximum of 30 wafts, one should commence with a lower power setting of 10 wafts for the about first 10 seconds, and then gradually adjust the knob on the RF generator to the set maximum of 30 watts, while still maintaining total RF delivery time at 60 seconds. When this technique was applied, it decreased coagulum formation, as is evident by the data shown in FIG. 10.
[0098] Specific characteristics of RF generators must be considered to obtain the gradual power rise described above. The IBI-1500T has 4 user-selectable choices for controlling the power delivery ramp-up curve. The Osypka 300 Smart and Cordis Webster Stockert have built-in algorithms which appear to automatically regulate power delivery rise time in a gradual manner, the latter allowing the end-user to specify a temperature ramp-up time. And finally, the Medtronic Atakr has no user override controls for power delivery application. In comparison, the Radionics RFG-3E allows the user to manually increase power output during the delivery of RF energy. In the present embodiment of this invention, the output power setting for RF energy to be delivered at the electrodes are user adjustable via the front panel knob (1-30 Watt). A lower power setting will increase the ramping time, since it takes a longer time to reach set temperature. An automatic algorithm which calculates the coagulum index (C.I.) in real-time can be incorporated into the information processor and RF output controller functionality so that a visual or auditory signal can alert the end-user whenever the risk for coagulum formation is high, i.e. C.I. greater or equal to 12. Alternatively, the information processor can calculate the C.I. in real-time and use this calculated value as information that is fed back to the RF output controller functionality so that the ablation episode can be carried out with minimal probability of coagulum formation.
[0099] Excellent electrode-tissue contact is determined by a combination of fluoroscopy, low initial impedance, and the quality of electrograms during the procedure. Results from the study reveal that excellent electrode-tissue contact, in combination with gradual RF power delivery to a maximum level of 30 to 35 watts, constitutes a sound prescription for best practice of RF ablation with the least likelihood of coagulum formation at the electrode site. Bench testing of tissue ablation has also demonstrated that good electrode contact with the tissue results in lower RF power consumption required to reach set temperature. Lower RF energy requirements in turn reduce the probability of coagulum formation.
[0100] The insights revealed in this example may be extrapolated to procedures using other catheters for other RF ablation procedures as well, and hence are presented here. The catheter MAZE procedure calls for the creation of linear ‘barricades’ along anatomical trajectories within the right atrium, using RF ablation to compartmentalize the chamber and ‘contain’ pro-arrhythmic electrical propagation.
[0101] Results of this study reveal the following considerations regarding minimizing coagulum formation during cardiac tissue ablation. In ideal situations, it is possible to achieve satisfactory tissue contact for all eight linear ablation catheter electrodes. However, the techniques discussed below yield acceptable results in right atrial MAZE linear ablation procedures even when the anatomical or flow conditions prevent optimal simultaneous contact of eight catheter electrodes.
[0102] a) Excellent contact should be established in as many linear array electrodes as possible.
[0103] b) Low tissue impedance at ‘baseline’ is indicative of effective contact; some RF generators permit this to be sensed and displayed prior to actual ablation by emitting a small RF current to interrogate tissue impedance at the ablation site.
[0104] c) Pacing threshold, if used as an indicator of contact, should be reasonable (1-2 mA); threshold values above 4-5 mA most likely indicate poor contact, and the catheter should be repositioned.
[0105] d) The sheath should be rinsed periodically (e.g. every 15 minutes) with a standard heparinized saline solution bolus. This improves contact by removing coagulum build-up on the electrodes and catheter shaft. If possible, the catheter should be pulled out of the Naviport deflectable guiding sheath after each trajectory; the electrodes should be wiped clean if needed, before re-introducing the catheter into the Naviport.
[0106] In addition to achieving excellent electrode-tissue contact, reduced coagulum formation can be obtained by regulating the RF power settings such that power is gradually increased and by setting the generator maximum power settings to 30W-35W with power monitored continuously. The catheter should be repositioned as needed to maintain set temperature at a lower power level. It has been observed that coagulum formation is more evident when power required to maintain set temperature approaches 50 W. Conversely, coagulum formation is minimized greatly when power required is less than 35 W. This may be seen as a challenge when trying to reach set temperature. However, with excellent electrode-tissue contact, desired set temperature can be achieved with as low as 7 W to 15 W of power delivery. In vivo animal studies have verified deep, transmural lesions with these low power settings when there is sufficient electrode-tissue contact.
[0107] While there has been illustrated and described a preferred embodiment of the present invention, it will be appreciated that modifications may occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.
Appendix A
Mathematical Derivation of Coagulum Index, using Dimensional Analysis of Physical Parameters Pertinent to RF Ablation
[0108] A mathematical model for distinguishing between coagulum or non-coagulum formation on the RF-ablating electrode of the Cardima REVELATION Tx catheter was developed. This model was based on dimensional analysis of physical constants pertaining to the units for various logged parameters during RF ablation episodes, and was verified using clinical data obtained as described in the Example section.
[0109] Definitions in S. L (System International) Units:
[0110] Mass=Kg [kilogram]
[0111] Length=m [meter]
[0112] Time=s [seconds]
[0113] Power=W [watts]=Kg*m 2 *s −3
[0114] Each single-electrode catheter ablation event has its own slope calculated from a plot of Power (Y-axis) vs. Time (X-axis), from baseline temperature (i.e., temperature of free-flowing blood in the heart=approximately 37° C.) to 50° C. In this analysis, this is the duration for the sensed temperature from a thermocouple to reach a set temperature, e.g., 50° C. If the set temperature cannot be reached, then it is the duration for the sensed temperature to reach the maximum temperature, for that ablation episode.
Slope = Power /Time = ( Work Done / Time ) / Time 2 = ( Force * Displacement ) / Time 2 = ( Mass * acceleration * Displacement ) / Time 2 Eqn. [1]
[0115] Dimensional Analysis of the units show that:
Slope = Kg * m * s - 2 * m / s 2
= Kg * m 2 * s - 4 Eqn. [2]
[0116] It follows that I/Slope is the reciprocal of Eqn. [2]:
1/Slope= Kg −1 *m 2 *s 4 Eqn.[3]
[0117] Now we define electrical capacitance, C, in terms of its fundamental units:
C=m
−2
*Kg
−1
*s
4
*I
2 [NIST]
Rearranging terms, C=Kg −1 *m −2 *s 4 *I 2 Eqn.[4]
[0118] Dividing both sides by I 2 :
C/I 2 =Kg −1 *m −2 *s 4 =t/W Eqn.[5]
[0119] Notice that Eqn. [3]=Eqn. [5]
[0120] Therefore, we can define capacitance as a function of the slope that we obtain for each ablation episode:
C=I 2 *( t/W )= I 2 /( W/t )= I 2 /Slope Eqn.[6]
[0121] In the presence of an alternating current, impedance Z is defined as:
Z= 1/(2 πfC ) Eqn.[7]
[0122] where f=operational RF frequency
[0123] Substituting Eqn. [6] into Eqn. [6], we are able to define Coagulum Index as follows:
Relative Impedance= k *( W/t )/ I 2 Eqn.[8]
[0124] where k=1/(2πf), and is constant for a particular RF generator, assuming that the RF oscillator frequency, f, is stable and constant. Therefore, for practical purposes, the proportionality constant k is ignored in the calculation since the same type of RF generator, the Radionics RFG-3E, was used throughout the study described in the Examples section. The results discussed in the Examples section showed a close correspondence between this calculated value and the probability of coagulum formation at the ablation electrode site. Therefore, the term Coagulum Index was given to this quantity. We therefore arrive at:
Coagulum Index=( W/t )/ I 2 | A system for efficient delivery of radio frequency (RF) energy to cardiac tissue with an ablation catheter used in catheter ablation, with new concepts regarding the interaction between RF energy and biological tissue. In addition, new insights into methods for coagulum reduction during RF ablation will be presented, and a quantitative model for ascertaining the propensity for coagulum formation during RF ablation will be introduced. Effective practical techniques a represented for multichannel simultaneous RF energy delivery with real-time calculation of the Coagulum Index, which estimates the probability of coagulum formation. This information is used in a feedback and control algorithm which effectively reduces the probability of coagulum formation during ablation. For each ablation channel, electrical coupling delivers an RF electrical current through an ablation electrode of the ablation catheter and a temperature sensor is positioned relative to the ablation electrode for measuring the temperature of cardiac tissue in contact with the ablation electrode. A current sensor is provided within each channel circuitry for measuring the current delivered through said electrical coupling and an information processor and RF output controller coupled to said temperature sensor and said current sensor for estimating the likelihood of coagulum formation. When this functionality is propagated simultaneously through multiple ablation channels, the resulting linear or curvilinear lesion is deeper with less gaps. Hence, the clinical result is improved due to improved lesion integrity. | 0 |
CROSS-REFERENCE TO PRIOR PROVISIONAL APPLICATION
This application corresponds to U.S. Provisional Patent Application Serial No. 60/127,229, filed Mar. 31, 1999.
BACKGROUND OF THE INVENTION
The present invention relates to the field of nondestructive testing, and, in particular, to the field of speckle-shearing interferometry, or shearography.
Nondestructive testing of aircraft structures, such as honeycombs, has been performed by techniques which include tap testing (i.e. using an inspector's ear to judge the presence of a skin-to-core disbond), impedance bond testing, and pulsed-echo ultrasonics. While effective, these prior art methods are either subjective, require considerable recalibration with changes in skin thickness, provide subjective interpretation, or are slow. Shearography has been found to be a more preferred method of nondestructive testing.
Shearography was first introduced by Hung and Taylor, in “Measurement of slopes of structural deflections by speckle-shearing interferometry”, Experimental Mechanics, vol. 14, pages 281-285 (1974), and by Leendertz and Butters, in “An image-shearing speckle-pattern interferometer for measuring bending moments”, J. Phys. E.: Sci. Instrum., vol. 6, pages 1107-1110 (1973). Shearography essentially comprises the formation of an image comprising two laterally-displaced images of the same object.
Shearography is a full-field optical speckle interferometric procedure which is capable of measuring small deformations of a surface. These deformations can be produced by several mechanisms, and are measured for several purposes. Deformation mechanisms include, among others, vacuum, pressure, microwave, thermal, vibration, and ultrasonic excitation. Purposes for measurement include stress analysis, vibration measurement, acoustic and elastic wave visualization, and other non-destructive testing (NDT) including detection of flaws in a test object.
The first practical apparatus for performing shearography electronically was introduced in 1987, and was based on the technology described in U.S. Pat. No. 4,887,899, the disclosure of which is incorporated by reference herein. The form of shearography described in the above-cited patent, using birefringent optics as a means of generating a sheared image, provided the first high-resolution, real-time shearography system which could produce images of disbonds due to out-of-plane deformations caused by vacuum stress of the skin of the structure being tested.
The first portable vacuum stress shearography instruments used video subtraction to provide rapid imaging of flaws. While this technology was a major advance in nondestructive testing, enabling one to perform tests at a rate of 150 square feet per hour, as compared with 3-8 square feet per hour using prior methods, the sensitivity of the technology to defects was limited. Subtraction shearography provides images of flaws only when the out-of-plane deformation exceeds one-half wavelength in the shear offset distance, the distance between the sheared images. The portable subtraction shearography devices of the prior art have found important uses in the aerospace field, in the inspection of composite honeycomb structures including radomes, composite fuselages, wheel doors, close-out panels, and many other components.
Portable vacuum stress shearography cameras are subject to several types of vibration, noise, and mechanical instabilities that considerably degrade the image quality and the ability to detect defects in aerospace structures. Not only do these sources of noise have to be eliminated with techniques that do not add weight and size to the portable instrument, but any method used to increase sensitivity must be made to run as fast as possible to prevent degradation of the images.
One method of increasing defect sensitivity is the use of phase-stepping shearography, introduced by Nakadate in 1985. While Nakadate demonstrated the use of phase-stepping and the increased defect sensitivity provided by phase map presentations, the software and hardware available at that time required ten minutes to yield the phase map image, far too slow for use in a practical nondestructive testing instrument. In addition, the phase step process requires capturing consecutive video frames and considerable arithmetic manipulation of between four and ten images to calculate the phase map. The level of noise rapidly increases as the time to perform the calculations increases, dramatically reducing sensitivity.
A basic setup of an electronic shearography system is as follows. Coherent laser light is spread out to illuminate a portion of the object's surface, e.g. one square foot. The light reflects from the surface, passes through an optical shearing mechanism, and then enters a CCD camera. The surface is then deformed by one of the aforementioned mechanisms, such as heat. As the surface expands slightly due to the applied heat, the deformation of the surface is viewed, in real time, on a video monitor. This deformation is usually not visible to the eye because it is on the order of the wavelength of the laser light being used, i.e. approximately 250 nm. Deformation of the surface often shows direct evidence of a subsurface flaw.
Shearography has evolved over the years from a film-based to a video-based (electronic, or analog) system, and finally to systems which store the images in a computer, in digital form. In its film-based form, shearography is typically limited to an optics laboratory. In its electronic or digital form, if the system is made compact, shearography can be removed from the laboratory, and used in real-world settings. It can survive environmental factors such as slight heat and vibration fluctuations due to its particular optical setup.
As implied above, there are two fundamental modes in which shearography can be used, namely, speckle correlation fringe formation due to subtraction, and phase map formation due to phase stepping. As already noted, phase stepping is beneficial since it results in increased signal-to-noise ratio (SNR), increased displacement resolution (resulting in increased flaw detection sensitivity), quantitative rather than qualitative results, and other factors. Either of the two modes (fringes or phase stepping) can be used with either of the three bases (film, electronic, digital), creating six combinations. Then there are more than seven known optical shearing mechanisms, and more than six known phase-stepping methods. The number of possible system implementations is hence quite high. Furthermore, the phase-stepping algorithm, of which there are at least ten, the computational method of implementing the algorithm, and the consequent speed with which the algorithm is executed are all important. These directly affect the accuracy and SNR of the final measurements as well as the rate at which a user can view the results and make slight changes. Finally, the entire optical system is either used as a research tool in an optics laboratory on a vibration-isolation table, or it must be packaged such that it can be taken into the field and used with several excitation mechanisms in order to find flaws effectively, efficiently, and conveniently.
The present invention provides a high-speed phase-stepping shearography system which requires less than about one second to produce an image, and which demonstrates remarkable stability, sensitivity, and image quality. Compared to the prior art, the present invention improves defect sensitivity by a factor of 50, enabling a portable shearography system to compete with widely-accepted ultrasonic systems, but at a speed of operation which is about 50 times faster.
SUMMARY OF THE INVENTION
The system of the present invention includes four subsystems, namely a shearography head, an enclosure, an excitation mechanism, and a computational subsystem. The shearography head preferably uses a Michelson interferometer to generate the sheared images, and can receive laser light either from an external laser, coupled by an optical fiber, or from a laser diode which is internal to the head. The amount of phase stepping is automatically adjusted by moving one of the mirrors of the Michelson interferometer, through the use of a piezoceramic disk which is controlled by a voltage determined by a computer. The amount of shearing is adjusted by manually tilting a different mirror in the Michelson interferometer.
The enclosure includes, at a minimum, a casing having a transparent window to permit laser illumination and formation of an image of the test object. In a preferred embodiment, the shearography head is mounted on the enclosure, the enclosure having a hole which cooperates with a similar hole in the shearography head, such that laser light can pass from the head, to the object, and back into the head, through the cooperation of various mirrors. The enclosure also includes means for stabilizing the system relative to the object being tested.
The excitation mechanism can be a vacuum, or it can be a thermal or vibration system. In the preferred embodiment, all three excitation mechanisms (vacuum, thermal, and vibration) are built into the same enclosure, so that any or all of these mechanisms can be used without modifying the apparatus. The preferred source of the vacuum is an external blower which is connected, through suitable holes in the enclosure, to the interior of the enclosure. The preferred source of thermal excitation is a grid of thin heated wires disposed near the transparent window of the enclosure, so as to be in a position to heat the test object. The preferred source of vibrational excitation includes a shaker/stinger/plunger arrangement which is built into the enclosure.
The computational subsystem includes a programmed computer which is connected, through appropriate analog-to-digital and digital-to-analog converters, to the components described above. In the preferred embodiment, the computer directs a four-step algorithm which captures and stores images of the test object at four different positions of the mirror, when the object is both in the deformed and undeformed states. Comparison of the stored images, coupled with application of a smoothing algorithm, yields a pattern that can be viewed, essentially in real time, on a video display.
The present invention therefore has the primary object of providing an apparatus for performing real-time digital shearography.
The invention has the further object of providing the benefits of the phase-stepping technique in real-time digital shearography for increased sensitivity and signal-to-noise ratio as well as quantitative rather than qualitative data.
The invention has the further object of providing real-time shearography, using a portable unit.
The invention has the further object of providing a shearography system which produces a high-resolution image in real time, and which can conveniently be used in commercial or industrial environments.
The invention has the further object of providing an integrated, compact digital shearography system, wherein a plurality of mechanisms for excitation are present in a single housing.
The invention has the further object of enhancing the efficiency of nondestructive testing of objects.
The invention has the further object of making it easier to search for defects in structures where interior access is difficult or impractical, such as in aircraft, space vehicles, boats, and civil-engineered structures.
The reader skilled in the art will recognize other objects and advantages of the present invention, from a reading of the following brief description of the drawings, the detailed description of the invention, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 provides a schematic diagram of a first embodiment of the shearography head used in the present invention.
FIG. 2 provides a schematic diagram of a second embodiment of the shearography head used in the present invention.
FIG. 3 provides a side view of the enclosure used in the present invention, showing the shearography head, in schematic form, mounted on top of the enclosure.
FIG. 4 provides a front view of the enclosure of the present invention, showing components used in generating three different types of excitation.
FIG. 5 provides a bottom view of the enclosure of the present invention, showing other views of the components used in generating the three different types of excitation shown in FIG. 4 .
FIG. 6 provides a timing diagram showing the various steps commanded by the computer in performing the method of the present invention, including the acquisition of an image for each of four positions of a mirror, in both the undeformed and deformed states of the test object.
FIG. 7 provides a reproduction of a photograph showing a phase map of a thermally deformed honeycomb structure, produced with the apparatus of the present invention, but having no smoothing.
FIG. 8 provides a phase map similar to that of FIG. 7, but including the effect of nonlinear smoothing.
FIG. 9 provides a photograph of a prototype system made according to the present invention.
FIG. 10 provides a photograph of a portable shearography unit, made according to the present invention, and being used to examine a test object.
DETAILED DESCRIPTION OF THE INVENTION
The present invention comprises four subsystems, namely, a shearography head, an enclosure, an excitation mechanism, and a computational subsystem. One embodiment of the invention is in a single portable hand-held unit, where the head and excitation mechanisms are integrated with the enclosure which is held by the user. The head/enclosure/excitation unit is attached to the computational subsystem. Two slightly different optical setups for the shearography head can be used in this embodiment. A second embodiment of the invention has the head inside the enclosure and mountable on a tripod; for this embodiment, the enclosure is simplified and excitation mechanisms are applied externally and are not integrated into the enclosure. Either optical setup for the shearography head can also be used with this second embodiment. All described combinations of optical setups and enclosures result in real-time high-resolution portable digital phase-stepping shearography. Two particular combinations result in real-time high-resolution portable digital phase-stepping shearography with integrated vacuum, thermal, and vibration excitation mechanisms.
The shearography head is shown in FIGS. 1 and 2. FIG. 1 shows an embodiment wherein laser light is generated externally of the head, and conveyed into the head by an optical fiber. FIG. 2 shows an embodiment wherein the laser source is a laser diode within the head. In both FIG. 1 and FIG. 2, the shearography head is the portion enclosed by the box.
In the embodiment of FIG. 1, laser light from coherent laser source A is connected to armored single-mode or polarization-maintaining (PM) optical fiber C, through adjustable optical fiber coupler B. Laser light from the fiber passes through diverging optics D and illuminates the test object. In the case of a hand-held unit, approximately one square foot of the object's surface is illuminated. In the case of a tripod-mounted embodiment, up to ten square feet can be illuminated, depending on available coherent laser power. Either the hand-held or tripod embodiment can be used with either of the embodiments of FIGS. 1 and 2.
The diverging optics can consist of several elements, but need at least a simple lens to focus and then diverge the light. Other elements can consist of custom-made or off-the-shelf anti-Gaussian lenses to distribute uniformly the illuminating laser light on the surface of the object.
Reflected light passes through an optical shearing mechanism. This mechanism can be one of many, but to meet the requirements of this invention, the mechanism selected is a modified Michelson interferometer. The Michelson interferometer includes two front-silvered mirrors J and H, and a nonpolarizing beam splitter cube G. Modification of the interferometer comes from the fact that one of the two mirrors is intentionally misaligned due to tilting. This tilting can be adjusted, resulting in adjustable shearing direction and magnitude, by mounting the mirror on an adjustable kinematic mirror mount I. A further modification is made to allow phase-stepping to take place.
The second mirror J is mounted to a piezoceramic (PZT) disk K, which is attached via two electrical leads to a voltage source. The PZT disk can require an external voltage amplifier, or be of a low-voltage variety for convenience; the latter was chosen in this implementation to promote portability.
Reflected light finally is imaged by a CCD camera E with attached imaging lens F. The imaging lens is chosen based on the field of view to be imaged, as well as the acceptable amount of transverse distortion. The CCD camera is chosen based on light sensitivity, noise characteristics, spatial resolution, and data throughput. Analog or digital CCD cameras can be used. In this implementation, a high resolution (1024×1024 cell) digital CCD camera was used, but higher resolution devices can also be used if data throughput is acceptable. This particular camera operates in “progressive line-scan mode”, allowing efficient digitization and transfer of data.
In the embodiment of FIG. 2, the laser light is produced by laser diode A. Light from diode A passes through beam shaping optics B and collimating optics C, before reaching diverging optics D. Elements E, F, G, H, I, J, and K are the same as in the embodiment of FIG. 1 .
The second subsystem of the present invention is the portable enclosure that houses the shearography head. In the embodiment where the enclosure is mounted on a tripod and excitation mechanisms are not integrated, the enclosure is simply a metal casing with a glass window for the laser illumination and camera imaging. The casing will also allow controls for camera focusing and aperture, as well as adjustable shearing (via the kinematic mount I of FIGS. 1 and 2 ), to protrude for adjustment by the user. In the embodiment wherein the enclosure is held by the user and contains integrated excitation mechanisms, the enclosure will be as illustrated in FIG. 3 .
FIG. 3 shows a side view of the enclosure A with the shearography head mounted on top of it. Images of the surface of a test object are captured by laser light which is fed from the shearography head B, down through a hole in the enclosure, reflected from mirror C and again from mirror D, and passed through window E, which may be made of glass or plastic. The laser light is reflected off of the surface of the object (not shown in FIG. 3 ), and enters the enclosure by passing again through window E. The light is then further reflected by mirrors D and C, and returns to shearography head B, where it enters the camera/lens/shearing combination. Stabilizing feet G will rock about a ball joint (not shown), allowing the unit to be pushed against the surface being measured while protecting the window E. Flaps F both keep out stray ambient light and also help to create a vacuum hold, described later.
In the case of a smaller camera and laser diode source, all components can be contained inside the enclosure itself and do not need to be mounted on top of the enclosure. In the latter case, there will be no hole on the top of the enclosure, and at least one of the two internal mirrors can be omitted.
The third subsystem of the present invention comprises the excitation mechanism. Several excitation mechanisms can be used either independently or in combinations. Sources of these excitation mechanisms can be built into the enclosure to allow convenient application at a touch of a switch. This concept is illustrated in FIGS. 4 and 5.
The three excitation mechanisms are 1) vacuum, 2) thermal, and 3) vibration. Vacuum is used in all cases, where tripod mounting is not used, to hold the shearography head and the enclosure firmly to the object, but is not varied during the data acquisition period when used only for this purpose. When used as such, vacuum is not considered an excitation mechanism but an integral part of the measurement procedure.
Vacuum can also be increased slowly during the data acquisition period to become an excitation source itself. The vacuum is applied by means of an external vacuum blower which reduces the pressure in a flexible rubber tube connected to the bottom of the enclosure. The path of the vacuum is routed through the enclosure and then through several holes in the glass or plastic window, evacuating the air lying between the window/flaps and the object's surface. This arrangement causes the surface of the object lying just under the window to be pulled toward the window.
Thermal excitation is performed by a grid of thin, heated wires lying between the outside surface of the glass/plastic window and the leveling feet. The wires heat up at a flip of a switch, and the surface of the test object thermally deforms. The wires are thin and will be barely resolved by the imaging system. Furthermore, due to subtraction algorithms, to be described later, most visual traces of the wires will be removed computationally.
Vibration excitation is performed by a shaker/stinger/plunger arrangement exiting the enclosure housing. The shaker is mounted inside the enclosure on a vibration isolation (dissipative) mounting, and the attached stinger passes through a hole in the frame of the enclosure. The end of the stinger has an attached rubber plunger which makes contact with the surface of the test object. When the shaker is snapped into place, pushing the enclosure against the test object will also engage the stinger/plunger. When the shaker is not snapped into place, the plunger does not make contact with the surface, allowing other excitation methods to be used.
FIG. 4 provides a front view of the enclosure with integrated excitation mechanisms. The figure shows glass or plastic window A, mounted within metal frame B of the enclosure. Rubber flaps C function as described above, namely to keep out stray light, and to enhance the vacuum hold. Stabilizing feet D are preferably made of plastic. Plunger E is attached to the shaker/stinger (not shown in FIG. 4 ). Holes F permit a vacuum to be applied. Heating wires G provide the desired thermal excitation.
FIG. 5 provides a bottom view of the enclosure of FIG. 4 . As in FIG. 4, window A is shown mounted within frame B of the enclosure. The figure shows rubber flaps C and plastic stabilizing feet D. The figure also shows shaker E, stinger F, and shaker mounting G. Plunger H is attached to the shaker/stinger. The grid of heating wires is shown as element I. Outlet J provides means for attaching a vacuum hose to the underside of the enclosure.
The fourth subsystem of the present invention comprises the computational algorithms for control, calculation, and display. Operation of the components within the shearography head is controlled by a host computer. The computer sends calibrated voltages at specific times to the PZT disk, sends signals to the camera to begin grabbing frames, receives data from the camera as images are captured, and can trigger excitation mechanisms to begin and end. Alternatively, the latter step can be performed manually. Timing and data throughput are crucial to the success of the data acquisition. After data is acquired, rapid data processing and display must be accomplished.
Several phase-stepping algorithms can be implemented, including 2-step, 3-step, 4-step, and 5-step methods. The 4-step algorithm will be illustrated, but the general procedure is the same for any of them.
The following steps occur in rapid succession:
1. The camera is triggered to capture one frame of the surface and send the data to the computer.
2. While the camera is between two successive video frames, a signal is sent to the PZT which causes the attached mirror to be translated by a calibrated distance.
3. Once the mirror has finished its travel, the camera is triggered to capture a second frame and send data to the computer.
4. A second signal is sent to the PZT to translate the mirror.
5. The camera is triggered and a third frame is captured.
6. A third signal is sent to the PZT.
7. The camera is triggered and a fourth frame is captured.
8. The optical phase for the first “object state” is calculated and stored.
9. A signal is sent to the PZT to return the mirror to its initial position.
10. The object is deformed, either manually or automatically, using one or a combination of excitation methods.
11. Once deformation is stopped, or is varying slowly, steps 1 through 7 are repeated.
12. The optical phase for the second “object state” is calculated, subtracted from the phase for the first object state, and the difference is rectified, converted to 256 values, and displayed on the screen as a gray scale image.
The phase calculation occurs at each pixel over all the images. For the four-step method, the equation is: Δ ( x , y ) = tan 1 [ I 8 ( x , y ) - I 6 ( x , y ) I 5 ( x , y ) - I 7 ( x , y ) ] - tan 1 [ I 4 ( x , y ) - I 2 ( x , y ) I 1 ( x , y ) - I 3 ( x , y ) ] . ( 1 )
where I 1 through I 8 are the eight captured images, described by
I 1 ( x,y )= I ′( x,y )+ I ″( x,y )cos[φ( x,y )],
I 2 ( x,y )= I ′( x,y )+ I ″( x,y )cos[φ( x,y )+ π / 2 ],
I 3 ( x,y )= I ′( x,y )+ I ″( x,y )cos[φ( x,y )+π],
I 4 ( x,y )= I ′( x,y )+ I ″( x,y )cos[φ( x,y )+ 3π / 2 ],
I 5 ( x,y )= I ′( x,y )+ I ″( x,y )cos[φ( x,y )+Δ( x,y )],
I 6 ( x,y )= I ′( x,y )+ I ″( x,y )cos[φ( x,y )+Δ( x,y )+ π / 2 ],
I 7 ( x,y )= I ′( x,y )+ I ″( x,y )cos[φ( x,y )+Δ( x,y )+π],
I 8 ( x,y )= I ′( x,y )+ I ″( x,y )cos[φ( x,y )+Δ( x,y )+ 3π / 2 ] (2)
Here, I′ is the bias intensity, I″ the modulation intensity, φ a random phase variable due to the diffuse reflection of laser light from the surface, and Δ is a quantity directly proportional to the differential displacement due to deformation. The resulting quantity has positive and negative values so it is rectified and converted to 8-bit (256 values) for gray scale display. It should be noted that speckle correlation fringe production due to subtraction is actually a subset of the above phase calculation equations, and can easily be performed by the same opto-mechanical and computational components.
Calculation using Equation (1) can be time consuming. In a report as recent as a February, 1999 article, a calculation of this type was described as taking approximately 10 seconds to calculate one phase map. Several factors allow the current system to accomplish the same task in less than 500 milliseconds. First, the actual data acquisition is rapid, due to the tight control of all the opto-mechanical components and their timed integration due to computer control. The phase shifting, data acquisition, and data transfer to the host computer take 132 milliseconds. Then, calculation of Equation (1) is not performed directly in the host computer's central processing unit (CPU), but uses a look-up table with pre-stored values for the tan −1 function. Calculation and display hence take approximately 300 milliseconds. Since the frame grabber, video random access memory (VRAM), signal generator, and CPU are the fastest available off-the-shelf components, and tight integration and control algorithms coupled with the use of look-up tables for phase calculation have been used, the system can hence capture, calculate, and display up to two phase maps per second. Details of this process are shown in FIG. 6, which is a timing diagram showing all events in the phase acquisition, calculation, and display process.
After calculation, the phase result displayed on the computer monitor or video screen shows deformation of the surface of the test object. An example of such a calculated phase map is shown in FIG. 7 .
A further calculation can be performed to smooth the calculated phase for higher quality display and easier visual location of flaws. Typical smoothing algorithms depend on low-pass filters, which are time-consuming. In order not to degrade the real-time display of the phase-stepping system, a “nonlinear filter” is implemented for fast smoothing. Invalid pixels (“noise”) are identified by failing any one of three criteria: a pixel has a zero value (null condition), a pixel has the maximum value allowed by the analog to digital converter of the camera (saturation condition), or four pixels (from the same (x,y) position in all four images) have insufficient modulation, where modulation is defined as: M ( x , y ) = 1 2 [ I 1 ( x , y ) - I 1 ( x , y ) ] 2 + [ I 4 ( x , y ) - I 2 ( x , y ) ] 2 . ( 3 )
A threshold value for the modulation test can be found by simple trial and error, as will be apparent to persons skilled in the art.
Once invalid pixels are known, they can be replaced by their valid neighbors. Bounds exist on this method in order not to propagate a single valid pixel over the entire image, and these bounds are checked at each invalid pixel being considered. The smoothing process takes approximately 200 milliseconds to cover a 1317 by 1035 pixel image. With nonlinear smoothing, the entire phase measurement and display process takes just over a half second, still allowing almost two smoothed phase maps per second to be displayed on the screen. The smoothed version of FIG. 7 is shown in FIG. 8 .
All of the above-described subsystems were built into a prototype system, which is shown in FIG. 9 . This prototype contains only vacuum excitation. FIG. 10 shows the vacuum-excitation shearography head being applied to nondestructive testing of aircraft.
As mentioned above, many combinations of optical components, setups, phase-stepping methods, and algorithms exist. The originality of the present invention resides, in part, in the combination of previously-available features never combined before, in addition to the fact that this combination yields a portable system and delivers real-time results to the user. For example, a high-resolution sensor has been combined, in the prior art, with phase-stepping shearography, but the sensor in the latter system was digitized film, which required both a stable optics laboratory and extended time for digitization and calculation. When a high-resolution sensor was combined, in the past, with phase-stepping digital shearography, it was removed from the darkroom, but the wealth of data took up to ten seconds to be transferred, calculated, and displayed on the screen. Fast phase-stepping has been used in the prior art, using look-up tables and integrated timing control, but only in a laboratory setting and with a low resolution sensor. This is the first time that a high-resolution sensor has been incorporated into a digital phase-stepping shearography system that was capable of displaying up to two phase measurements per second. Hence, this sensor, in configuration and capabilities, is unique even when mounted on a tripod and not integrated with a user-held enclosure or excitation mechanisms.
Furthermore, the system of the present invention has been packaged in a user-held enclosure with an integrated vacuum hold, allowing the entire system to be brought into the field and firmly mounted to the object being studied. A similar enclosure has been used with analog subtraction shearography technology, but this is the first time that the portability, convenience, and vacuum holding abilities have been combined with high-resolution real-time digital phase-stepping shearography.
Still further, the present invention provides a novel configuration for integrating thermal and vibration excitation into the portable enclosure. While extremely convenient and effective for flaw detection, this arrangement has not been suggested or realized before. It brings the power of three, rather than one, excitation mechanisms to the aid of portable high-resolution real-time digital phase-stepping shearography. | A portable nondestructive testing instrument uses high-speed phase-stepping shearography, and vacuum stressing, to produce images of disbonds, impact damage, or delaminations, in metal or composite structures. The invention is especially useful in the inspection of large areas where only external access is feasible, such as in large aircraft, space vehicles, boats, or civil engineered structures having multiple bond lines. The invention includes a novel combination of components and techniques, including a high-spatial-resolution CCD sensor, low-voltage piezoceramic phase stepping, rapid phase stepping, a fast phase calculation technique, a fast image smoothing technique, and an implementation of all of the above in a portable unit. Specially designed timing and control algorithms allow data acquisition, transfer, calculation, smoothing, and display at rates of up to two times per second. The invention also includes the above-described combination, in conjunction with three excitation mechanisms provided in an integrated portable package. | 6 |
BACKGROUND OF THE INVENTION
The present invention is in the field of composite ceramics and particularly relates to panels or other structures formed of composite ceramics and exhibiting good strength and stiffness at high temperatures.
A general configuration for a strong, rigid flat structural member or panel, whether formed of paperboard, plastic or other material, consists of a corrugated or pleated central ply sandwiched between opposing flat plies or facing sheets. The corrugation or pleating of the control ply imparts higher stiffness to the composite, particularly against bending about axes in the plane of the panel transverse to the channels formed by the pleated or corrugated central ply, but also about axes paralleling these channels. Thus bending of the panel normally requires bending or rupture of the curved or angled portions forming the corrugation or pleating, and in fact the rigidity of the composite can be improved by increasing the stiffness of the corrugation or pleating material.
Ceramic structures embodying corrugated or channeled designs have been developed for high temperature applications, although in some cases the end uses have involved fluid (gas) treatment or heat exchanging rather than structural support. U.S. Pat. Nos. 3,112,184 and 3,904,473 describe the manufacture of ceramic honeycomb structures of this type, while U.S. Pat. No. 4,617,072 discloses carbon and carbon-fiber composite honeycomb structures intended for high-temperature structural applications.
Composite ceramics of the type currently being developed for high temperature applications typically consist of a matrix phase composed of a glass, crystalline ceramic, or semicrystalline glass-ceramic within which is disposed a reinforcing phase composed of an inorganic fiber or whisker material such as carbon, silicon carbide, alumina, silicon nitride or the like. These composites may find use in structural applications such as high temperature engine components, and the incorporation of a reinforcing whisker or fiber phase has been deemed necessary to attain the strength and toughness needed for this use. U.S. Pat. Nos. 4,615,987 and 4,626,515 describe compositions for composite ceramics of this type.
Fiber-containing composite ceramics produced for high-temperature applications have generally been prepared by processes involving the coating of individual fibers or the impregnation of fiber yarns, mats or cloth with solutions or suspensions of glass or ceramic particles, followed by the consolidation of the resulting fibers or mats into dense composite materials with heat and pressure. U.S. Pat. No. 4,568,594 describes a method for impregnating a multidirectional woven network of fibers in a suspension of ceramic powder, while U.S. Pat. No. 4,581,053 discloses a process wherein an individual fiber is coated with a glass powder suspension, and thereafter dried and woven into a predetermined structural shape. U.S. Pat. No. 4,613,473 describes yet another approach wherein both the matrix and the reinforcement are provided in fiber form and both are woven together to produce a cloth which can be consolidated to a dense composite material.
The need for stiffness in fiber composite structures such as beams and panels has fostered the development of structural designs and fabrication techniques which take advantage of the generally high elastic moduli of commercially available fibrous reinforcement materials. In the case of fiber-resin composites, for example, U.S. Pat. No. 4,591,400 discloses the use of a removable mandrel as a temporary substrate for laying up hollow beam members of resin-impregnated glass fibers. The hollow beams can thereafter be stiffened with auxiliary composite elements and/or shaped by subsequent molding to provide structural elements such as I-beam members, with the glass fibers imparting the desired stiffness and strength to the final structure.
As noted in U.S. Pat. No. 4,568,594, however, the fabrication of rigid composite structures in ceramic systems is complicated by the nature of the ceramic matrix materials. Hence, these materials are generally available only in granular or fine particulate form, and the uniform impregnation of complex fibrous structures with the matrix can be difficult. Nevertheless, composite ceramic structures of the highest possible density are required to optimize strength and rigidity, and therefore the forming procedure which is selected to fabricate such a structure must be one which insures product homogeneity and minimizes structural porosity or voids.
It is therefore a principal object of the present invention to provide a fabrication method for making rigid composite ceramic structures such as panels or beams which provides a product of high strength, improved stiffness and minimal porosity.
It is a further object of the invention to provide a design for a bonded composite ceramic structure which insures optimum strength and, especially, stiffness in the product.
Other objects and advantages of the invention will become apparent from the following description.
SUMMARY OF THE INVENTION
The present invention addresses the need for improved composite ceramic structures such as panels, beams or the like by providing a bonded ceramic structure wherein enhanced strength and stiffness is provided by combining one or more ceramic facing sheets with one or an array of relatively thin-walled, hollow, high-stiffness channeled ceramic support elements. One or more of the support elements are bonded to the facing sheet or between facing sheets, being positioned for bonding so that the channel axis of each support element (the axis substantially centered within the hollow channel cross-section and parallel with the channel walls) is generally parallel with the facing sheet(s). The support elements are made from a fiber-reinforced composite ceramic material wherein the orientation of the fibers within the support is controlled to achieve high strength and stiffness in the support.
The bonded ceramic structures of the invention can be directly used, for example, as beam or panel members, or they can be combined with additional members or other high strength metal or ceramic parts to provide complex refractory high-strength structures. The design of the bonded ceramic structure imparts particularly high resistance to bending or crushing deformation thereto.
The facing sheet of the composite ceramic structure of the invention preferably consists of a sheet of composite ceramic material comprising a glass, glass-ceramic, or crystalline ceramic matrix in which is disposed an inorganic reinforcement phase. The inorganic reinforcement phase is preferably a fibrous reinforcement consisting, for example, of inorganic whiskers or fibers.
The channeled composite ceramic support elements are of modular design, each individual support comprising a continuous composite ceramic wall defining a circumferentially enclosed elongated channel. The wall consists of a glass, glass-ceramic, or crystalline ceramic matrix phase within which the fiber reinforcement phase, consisting of a multiplicity of inorganic fibers, is disposed. The fiber reinforcement is multidirectionally oriented within wall of the support structure, i.e., the fibers run in at least two and preferably more different directions. Multidirectional orientation is typically achieved by providing multiple layers or plies of aligned fibers within the wall, the layers being arranged in cross-ply orientation with respect to each other. This multidirectional orientation has the effect of insuring that some of the fibers traverse the corners of the channel wall, imparting high corner strength and enhancing crush resistance in the bonded structure.
The process for making the support elements generally comprises, first, providing a mandrel or similar support having a cross-sectional shape generally corresponding to the channel shape selected for the ceramic supports to be provided. A preform for the ceramic support is then built up on the mandrel by winding or otherwise applying on the mandrel one or more layers of inorganic reinforcing fibers thereto. The fibers are coated before, during, or after application to the mandrel with particles of a ceramic material selected from the group of glasses, thermally crystallizable glasses, or crystalline oxides.
Finally, the support preform is consolidated into an integral composite ceramic support element by heating it to a temperature at least sufficient to consolidate the particles of ceramic material into an integral matrix within which the inorganic reinforcing fibers are disposed. In general, consolidation may be carried out before or during the bonding of the support elements to the support sheets.
DESCRIPTION OF THE DRAWING
The invention may be further understood by reference to the drawing wherein:
FIGS. 1a-1b schematically illustrate ceramic structural designs in accordance with the prior art;
FIGS. 2 and 3 schematically illustrate designs for bonded composite ceramic structures provided in accordance with the invention;
FIGS. 4(a-d) schematically illustrate impregnated fiber ply and mandrel components useful for making a ceramic support element of triangular prism cross-section in accordance with the invention; and
FIG. 5 is a schematic illustration in cross-section of a lay-up design for a composite ceramic support element to be incorporated into a bonded composite ceramic structure according to the invention.
DETAILED DESCRIPTION
The bonded composite ceramic structures of the invention are best made employing composite ceramic materials such as have been recently developed for applications wherein strength, toughness, and creep resistance at high temperatures are required. These may generally be described as fiber- and/or whisker-reinforced glasses, glass-ceramics (i.e., crystalline ceramics made by crystallizing glasses), and conventional ceramics (i.e., crystalline ceramics made by consolidating or fusion-casting non-glass forming crystalline oxide materials) wherein the fibers and/or whiskers enhance the high-temperature physical properties of the matrix glasses, glass-ceramics, or ceramics.
The use of inorganic whiskers and fibers to reinforce glasses, glass-ceramics and ceramics is well known. Whiskers have frequently been characterized in the literature as relatively short, single-crystal fibers of small diameter (typically less than 100 microns), whereas fibers, while of similar diameter, are considered to be multicrystalline or amorphous and are generally longer than whiskers, so that they can be used in woven or otherwise interlocking bundles, yarns, or cloth.
The mechanism of strengthening of glass, glass-ceramic, or ceramic bodies by fibers is considered to be that of load transfer by the matrix to the fibers through shear. This load transfer shifts stress from the glass or ceramic matrix to the relatively long, high modulus fibers, while the fibers at the same time may act to impede crack propagation in the matrix material.
Whiskers are thought to impart strengthening by a similar mechanism, but load transfer to whiskers by the matrix is more limited due to the limited length and aspect ratio of the whiskers. Theoretically, a whisker which is sufficiently short will not be loaded to the breaking point by the matix under stress, and therefore full advantage cannot be taken of the high strength of the whiskers. However, since whiskers are typically incorporated as a randomly dispersed phase in a selected glass or ceramic matrix, rather than in a preferential alignment as with fibers, the physical properties of the composites are generally more isotropic.
Among the whiskers and fibers which have been suggested for use as reinforcement for nonmetal (ceramic) matrix materials are silicon carbide, silicon nitride, alumina and carbon whiskers. The use of such whiskers to impart improved strength and toughness to alumina, boron carbide, and mullite ceramics is described in U.S. Pat. No. 4,543,345. U.S. Pat. Nos. 4,615,987 and 4,626,515 describe ceramic composites wherein the matrix phases consist of glasses or glass-ceramics.
Prior art structures designed for rigidity and/or strength frequently have designs such as illustrated in FIGS. 1a and 1b of the drawing, each design comprising facing sheets 1 and corrugated or pleated stiffening or support elements 2. Rigidity in such structures depends largely on the inherent stiffness or resistance to deformation of the corrugated or pleated elements, with the bending or crushing of such structures typically resulting from the failure of the members 2 along arc portions 3 in FIG. 1b or at corner points 4 in FIG. 1a.
As schematically illustrated in a preferred embodiment in FIG. 2, which is a partially exploded view of a bonded ceramic structure in accordance with the invention, the bonded structure generally comprises discrete stiffening or support elements 2. These are shown in FIG. 2 as being of triangular prism cross-section, although other polyhedral cross-sections could be used, and in the actual completed structure the support elements would be bonded to the facing sheets 1 and also preferably to each other. The triangular prism elements are formed by circumferential wall segments 5, and are made from a fiber-reinforced composite ceramic material exhibiting high stiffness so that they strongly resist deformation by corner bending or wall flexing.
It is not essential that all of the support elements in the array of elements making up the ceramic structure be bonded to a facing sheet since, as indicated in FIG. 2, a bonded parallel array of support elements arranged in alternating upright and inverted positions itself forms planar surfaces. FIG. 3 of the drawing, which is another schematic partially exploded view, illustrates a ceramic structure according to the invention comprising a more complex sandwiched support element array. In FIG. 3, a central array or sub-array 6 of the support elements is positioned for bonding between opposing sub-arrays 7 and 8, with facing sheets 1 to be bonded only to the latter two sub-arrays.
As previously noted, the necessary strength and stiffness in the completed structure require that the fiber reinforcement within each support element include fibers or fiber groups which are multidirectionally oriented in the ceramic walls of the support so that some of the fibers traverse the corners in the walls. In this way, side or corner failure within the support cannot occur unless such fibers fail in tension. The fibers or fiber groups may comprise individual fibers, a fiber yarn, or fiber tows, or they may be provided in a fiber fabric or cloth wherein the warp or woof of the fabric defines the predominant direction of fiber travel therein.
As also previoully noted, fiber multidirectionality (meaning at least two different fiber orientations) in the channel wall of the support is conveniently provided by cross-ply layering of the fibers. Desirably, each fiber layer will consist of a planar array of parallel, substantially unidirectional fibers imparting a definite prevailing fiber direction to the material. The layers can be provided, for example, by laying up parallel strands of matrix-impregnated fiber yarn.
Due to fiber multidirectionality, at least some of the fibers will be disposed so that a vector component of the fiber direction will be perpendicular to the channel axis of the support, i.e., a vector component directed circumferentially about the channel to assure fiber traverse of the corners of the channel walls. It is preferred however, that no fibers be directed purely circumferentially about the channel axis, since such an arrangement risks excessive fiber deformation and/or breakage during laydown and consolidation of the channel support preform. Most preferably, prevailing fiber directions will fall between ±60° of the direction of the channel axis of the support.
Components for the fabrication of a composite ceramic support element are schematically illustrated in FIG. 4 of the drawing. In FIG. 4, a mandrel 40 and three inorganic fiber mats 10, 20 and 30 are shown, each mat including fiber yarn or bundles (not individually shown) comprising largely parallel spun or bundled inorganic fibers predominantly directed, respectively, in the directions 11, 21, and 31 shown. Suitable dimensions for the mats relative to triangular mandrel 40, which mandrel could be used for laying up a triangular prism support member of length l and facing width w as shown against the mandrel, are shown adjacent mat 30. The mats may, if desired, consist of prepregs, i.e., with the fibers pre-impregnated with a suspension of particulate ceramic material.
FIG. 5 shows a support element preform resulting when prepreg fiber mats such as shown in FIG. 3 are sequentially applied to a mandrel. The mats 10, 20, and 30 are applied in sequence so that the overlap of each mat occurs on a different face of mandrel 40. This equalizes wall thickness about the preform while insuring that all corners of the preform comprise three fiber layers, applied in cross-ply arrangement as indicated by the fiber group direction indicated in FIG. 4. The result after consolidation is a strong, continuous polyhedral wall.
The particular ceramic material selected for use as the matrix in the composite wall of the ceramic preform and/or in the composite ceramic facing sheets is not critical, but will depend on the specific application for which the bonded composite ceramic structure is intended. For use at moderate temperatures, particulate glass may comprise the ceramic material. ("Ceramic" in the context of the present description is used in the broad sense to include glasses, glass-ceramics, and crystalline ceramics.) Examples of suitable glasses include alkaline earth aluminosilicate glasses, aluminosilicate glasses, borosilicate glasses and high silica glasses, all of which are known in the art. Particularly suitable are alkaline earth aluminosilicate glasses of RO--B 2 O 3 --Al 2 O 3 --SiO 2 composition wherein RO is one or more oxides selected from the group MgO, BaO and CaO, as disclosed for example in U.S. Pat. No. 4,626,515.
For use at somewhat higher temperatures, particulate thermally crystallizable glasses may be used as the ceramic material. Glasses of this type can be selected which will crystallize at the temperatures utilized to consolidate the ceramic material around the fibers. Thus a semicrystalline or fully crystallized matrix is provided which provides a composite more resistant to dimensional creep at high temperatures.
Examples of useful thermally crystallizable glasses for this application include lithium aluminosilicate, magnesium aluminosilicate, aluminosilicate, and alkaline earth aluminosilicate thermally crystallizable glasses. Particularly preferred are the alkaline earth aluminosilicate glasses and U.S. Pat. No. 4,615,987 discloses specific examples of such glasses which may be employed in the practice of the present invention.
The highest refractoriness and creep resistance in a bonded ceramic structure according to the invention is provided where the selected matrix material is composed of a conventional ceramic material such as Al 2 O 3 , ZrO 2 , mullite, boron carbide, silicon carbide, silicon nitride or the like, which materials are generally completely free of residual glass. However, higher consolidation temperatures and pressures are generally needed to convert the particulate ceramic material to a continuous matrix, and the strengths of the composite bodies tend to be somewhat lower than in the case of composites wherein the particulate ceramic material can be sintered as a glass.
The inorganic fibers used to provide the fiber reinforcement in the support element and, optionally, the facing sheets, may be selected from among the known fibers suitable for the reinforcement of ceramic materials. Depending upon the particular matrix selected, however, the fibers will typically be selected from the group consisting of carbon, alumina, silicon carbide, silicon nitride, boron nitride, boron carbide, zirconia, zircon, mullite, or spinel fibers.
In the case of either the facing sheets or the support elements, inorganic whisker reinforcement may also be provided to enhance the strength and/or toughness of the composite ceramic material. SiC whiskers are the preferred whisker reinforcement for this purpose although other whisker reinforcement materials such as hafnium carbide, silica, alumina or graphite may alternatively be employed.
Whereas the support members must comprise at least some fiber reinforcement to provide the requisite stiffness and corner strength, the inorganic reinforcement phase disposed within the facing sheets may consist entirely of whisker reinforcement, if desired. In any case, where whiskers are to be provided in the composite ceramic material forming the facing sheets or support elements, they are most conveniently introduced into the composition as a ceramic additive, i.e., mixed with the particulate ceramic material as it is applied to the inorganic fibers or fiber groups. The whiskers are ordinarily of sufficiently fine dimensions that they can be combined with the selected ceramic material without unduly modifying the coating characteristics thereof.
Bonding of the face sheet and support elements into a bonded composite ceramic structure may be accomplished using known cementing or sealing methods. For glass composites, glass frit sealing provides a suitable cementing technique, whereas for glass-ceramic or ceramic components, sealing with devitrifiable (thermally crystallizable) cements will provide a more refractory and creep-resistant bonding method.
The invention may be further understood by reference to the following theoretical example thereof, which is intended to be illustrative, and not limiting.
EXAMPLE I
A known thermally crystallizable alkaline earth aluminosilicate glass suitable for use as a matrix material in a composite ceramic material is provided in particulate form. The glass has a composition consisting essentially, in parts by weight, of about 50.63 parts SiO 2 , 27.66 parts Al 2 O 3 , 13.27 parts BaO, 3.44 parts MgO, and 1.0 parts As 2 O 3 , and can be thermally crystallized at temperatures of 1350° C. and above to yield one or more of barium osumilite, cordierite, mullite, and barium aluminosilicate crystal phases depending upon the precise thermal treatment employed.
The particulate glass is milled to a fine powder (average particle size of 5 microns) and is mixed with a liquid vehicle to form a flowable slurry. The liquid vehicle consists essentially, in parts by weight, of 92.5 parts H 2 O, 7.5 parts isopropyl alcohol, and 6 parts of polyvinyl acetate as an organic binder.
To prepare a glass-impregnated fabric or cloth of reinforcing fibers, i.e., a prepreg, a silicon carbide fiber yarn (Nicalon NLM 202 yarn) is passed through a burner flame to remove organic sizing on the fibers, and is then transported through the glass slurry to impregnate the yarn with particulate glass. The impregnated yarn is then wound around a rotating drum to provide a continuous sheet or mat having a substantially unidirectional fiber orientation, and is thereupon dried at room temperature to form a green flexible prepreg. The prepreg is then cut from the drum and flattened to form a quadrangular sheet for subsequent lamination and consolidation.
A graphite mandrel of triangular prismatic cross-section is next provided, the length of the mandrel being approximately 12 inches and the cross-section being an equilateral triangle such that the faces of the mandrel are of approximately 1 inch in width, but with slightly rounded long edges.
Three rectangular prepreg mats are next cut from the prepreg sheet above described, the mats having a width corresponding to the length of the mandrel and a length approximately four times the width of the faces of the mandrel prism. The mats are cut so that the first mat has a fiber direction parallel to the mat length (0° offset), while the second and third mats are cut with the fiber direction offset +60° and -60°, respectively, from the direction of the mat length.
The prepreg mats thus provided are next wound sequentially onto the graphite mandrel to form a support member preform. The mats are applied so that, for each mat, the starting point for winding is on a different face of the mandrel prism. The result of laying up the preform in the manner described is that one fiber layer comprises fibers directed longitudinally of the mandrel fibers (parallel with the direction of the preform channel), while the remaining two layers comprise fibers forming spiral windings of +30° and -30° pitch about the mandrel axis.
Consolidation and crystallization of the preform thus provided are simultaneously carried out by encasing the preform and mandrel in a tantalum metal casing and subjecting the encased components to hot isostatic pressing at 15,000 psi at 1350° C. for one hour. Following consolidation and crystallization, the composite ceramic triangular prism support is removed from the graphite mandrel, yielding a channeled composite ceramic support member of high toughness and strength.
Cmposite ceramic facing sheets for the ceramic structural member are next provided by cutting rectangular mats from prepreg sheet produced as above described, and consolidating the mats to form the desired facing sheets by hot pressing or the like. Suitably, four 0° offset prepreg mats are stacked in cross-ply fashion, alternating the fiber direction 90° with each mat, and then the stack is hot pressed at 1450° C. and 15,000 psi for 10 minutes to provide a consolidated crystallized composite ceramic sheet comprising cross-ply SiC fiber reinforcement.
A bonded composite ceramic structure is produced from the above-described components by combining multiple triangular support elements produced as described into a channel-parallel array and then covering the array with opposing facing sheets to form a sandwich structure. A planar array consisting of 23 triangular support elements produced as above described is assembled, consisting of alternating upright and inverted parallel prisms in face-to-face contact forming a close-packed linear array of support elements as generally shown in FIG. 2 of the drawing. A novel bonding cement forming no part of the present invention, made from the flowable slurry of thermally crystallizable glass above described but additionally containing 2 parts by weight of SiC whiskers for each 8 parts by weight of powdered glass, is applied to all contacting faces of each support element prior to assembly.
To the opposing faces of the planar support element array produced as described are applied opposing fiber-reinforced composite ceramic facing sheets made by the cross-ply lamination of prepreg mats in accordance with the above description. Again, bonding cement is applied to the contacting faces of the facing sheets and exposed bases of the support elements prior to assembly.
The assembled structure thus provided is finally heat-treated at 1400° C. for 1 1/2 hours to sinter and crystallize the cement and to thereby bond the component support elements and facing sheets into a unitary composite ceramic structural member. This structure would exhibit excellent strength and toughness in service at temperatures of 1200° C. or higher, due to the modular design of the fiber-reinforced support elements and the excellent creep resistance of the glass-ceramic matrix material employed.
Of course, the foregoing example is merely illustrative of the invention hereinabove described, and numerous variations and modifications of the example, including the use of alternative materials and procedures equivalent to those set forth herein, may be resorted to within the scope of the appended claims. | Bonded ceramic matrix composite structures such as ceramic panels or beams, and a method for making them, are described, the structures comprising ceramic facing sheets to which are bonded one or an array of relatively thin-walled, hollow, high-stiffness channeled ceramic support elements, the support elements being of modular design with each support being formed by a continuous composite ceramic wall incorporating multidirectional fiber reinforcement and defining a central channel extending, in the bonded structure, in a direction generally parallel with the ceramic facing sheets. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a tapered waveguide used for an optical probe in a scanning near-field optical microscope which is one of scanning probe microscopes and can provide information on the characteristics of surface optical properties, a scanning near-field optical microscope using the optical probe having the tapered waveguide, and a method for forming an aperture of the tapered waveguide.
A scanning probe microscope represented by an atomic force microscope (hereinafter referred to as an AFM) or a scanning tunneling microscope (hereinafter referred to as an STM) has wide spread use because of its performance of observing the sample surface in high resolution.
On the other hand, various types of scanning near-field optical microscopes which can provide optical characteristics and topography of sample surface have been proposed. The scanning near-field optical microscopes control the distance between the tip of a sharpened optical probe including an optical waveguide and sample surface to smaller than optical wavelength. One microscope holds the optical fiber probe vertically to the sample and vibrates the tip of the probe horizontally to the sample surface. Variation in vibration amplitude caused by friction between the tip of the probe and the sample surface is detected as a displacement of the optical axis of laser light which has been irradiated from the tip of the probe and transmitted through the sample. The distance between the tip of the probe and the sample surface is kept constant during scanning by controlling a Z-axis positioner. Thus the scanning near-field optical microscope can provide distribution of the intensity of transmitted light through the sample and topography of the sample surface.
Another is a scanning near-field optical/atomic force microscope which uses a sharpened and bent optical fiber probe as a cantilever of an AFM. The scanning near-field optical/atomic force microscope can measure the characteristics of surface optical properties and topography simultaneously by applying a laser light to the sample from the tip of the optical fiber probe during its AFM operation.
Such a scanning near-field optical microscope which measures optical characteristics and a topography of a sample at the same time uses a tapered waveguide for an optical probe. The optical probe has a coating film on its tapered portion except its aperture.
FIG. 7 is a sectional view showing a conventional composition of an optical probe. Number 1 is an optical waveguide whose tip has been sharpened and number 51 is a coating film. The coating film 51 is composed of a single layer and is composed so as to have the same plane as the aperture surface. In case that this optical probe is mounted on a scanning near-field optical microscope, its topographical resolution is limited by the tip diameter of the optical probe including its coating film and its optical resolution by size of the aperture in the probe tip. For example, in case that the tip diameter of the tapered waveguide itself is 100 nm and the thickness of the coating film is 100 nm, provided that the coating film does not enter the aperture, the aperture is 100 nm in diameter and the tip of the optical probe including the coating film is about 300 nm in diameter.
In order to improve the topographical resolution, it is necessary to make the tip of an optical probe small in diameter. However, when the coating film is deposited thin, leaked light through the circumference of an aperture deteriorates optical resolution and contrast of optical characteristics.
On the other hand, when the coating film is deposited thick enough so as to not leak light, optical resolution and contrast of optical characteristics are deteriorated by reduction of an amount of light outputted from the aperture due to the coating film burying of the aperture in addition to deterioration of topographical resolution.
In the composition of the optical probe according to the prior art shown in FIG. 7, for a range of wavelength around 500 nm, a coating film 51 of aluminum can be coated ideally to about 50 nm in thickness, but actually needs to be about 100 nm in consideration of deterioration in its film quality and occurrence of pinholes. In this case, the tip of the optical probe is at least 200 nm or greater in diameter.
Furthermore, in case of additionally depositing a protective film outside the coating film or in case of additionally depositing a functional film such as a magnetic film and the like, the same problem as the above-mentioned case of depositing a thick coating film occurs.
SUMMARY OF THE INVENTION
An object of the invention is to provide an optical probe which is capable of measuring a topography and optical characteristics in high resolution in a scanning near field optical microscope.
Another object of the invention is to provide a method for forming an aperture of the optical probe improving a resolution of a topography and a resolution of optical characteristics in a scanning near field optical microscope.
In order to achieve the objects, an optical probe has a metal coating film at the end part except the aperture part has a curved surface retreating gradually from said aperture to the outer circumference at the end of said aperture part. And the coating film is composed of a first coating film forming the aperture part and a second coating film which is outside the first coating film and is formed into the shape of a taper in the vicinity of the end part.
On the other hand, a method for forming the aperture of the optical probe uses a process of depositing a metal film by means of a vacuum evaporation process as using an evaporation source which is long in the direction parallel with the tip part of the waveguide.
And another method for forming an aperture of an optical probe uses a process of depositing a metal coating film by means of a vacuum evaporation process using vapor generated from at least two or more evaporation sources disposed side by side in parallel with the direction of the tip part of the waveguide.
Furthermore, the other method for forming an aperture of an optical probe uses a process of depositing a first coating film from the side direction of the waveguide and a process of depositing a second coating film toward the tip from behind the depositing direction of the first coating film.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing composition of an optical probe showing the first embodiment of the invention;
FIG. 2 is a sectional view showing composition of an optical probe showing the second embodiment of the invention;
FIGS. 3A-C is a process diagram showing a method for forming an aperture of an optical probe of the invention;
FIG. 4 is a figure showing a method for forming an aperture of an optical probe of the invention;
FIG. 5 is a figure showing a method for forming an aperture of an optical probe of the invention;
FIG. 6 is a figure of composition of a scanning near-field optical microscope using an optical probe of the invention; and
FIG. 7 is a sectional view showing composition of an optical probe of the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the invention are described in the following with reference to the drawings.
FIG. 1 is a sectional view showing an optical probe according to a first embodiment of the invention. Number 1 is an optical fiber which is a waveguide and number 4 is a metal coating film, and the optical fiber 1 has a composition in which its tip is sharpened and its end part 5 is covered with a metal coating film 4 except its aperture part or optical opening 5a. The metal coating film 4 has a curved surface portion 4a retreating gradually from the aperture part to an outer circumference of the waveguide and a tapered surface portion 4b contiguous with the curved surface portion 4a and disposed on the outer circumference of the waveguide. As the optical fiber 1, a single-mode fiber, a multi-mode fiber, and a polarization-preserving fiber which vary in core diameter and in cladding diameter can be used. As another waveguide a capillary can be also used. As a material for the metal film 4, a light reflecting material such as gold, platinum, aluminum, chromium, nickel, or the like is used.
According to a composition as described above, it is possible to reduce an influence of thickness of a metal coating film upon a resolution of topographic image and easily make the metal coating film greater in thickness by making the metal coating film into the shape of a curved surface at the end of the aperture part. Therefore, it is possible to prevent a light from leaking through the circumference of the aperture as well as to prevent the aperture from being buried and to reconcile to each other improvement in resolution of a surface structure and improvement in optical resolution.
The composition of the optical probe as described above can be implemented in an optical probe whose tapered part is straight or in a optical probe whose tapered part is hook-shaped.
FIG. 2 is a sectional view of composition of optical probe showing a second embodiment of the invention. Number 1 is an optical fiber which is a waveguide, number 2 is a first coating film and number 3 is a second coating film, and the optical fiber 1 has a composition in which its tip is sharpened and the part of its end part 5 except the aperture part is covered with the first coating film 2 and the second coating film 3 has a tapered surface portion 3a in the vicinity of the tip part and disposed outside the first coating film 2. The tapered surface portion 3a of the second coating film 3 diverges to an outer circumferential surface 3b of the second coating film. The outer circumferential surface 3b and the tapered surface portion 3a extend at different taper angles relative to a central axis A of the optical fiber 1. As a material for the first coating film 2, a light reflecting material such as gold, platinum, aluminum, chromium, nickel, and the like is used. As a material for the second coating film 3, the same material as the first coating film is used or another metal or nonmetal material which has anisotropy in the depositing direction and can be deposited by means of a thin film depositing means.
The combination of materials for the first and second coating films 2 and 3 can be selected according to a purpose of the use of a probe. Usually, the same material having a high reflectivity such as aluminum, gold and the like is used for both of the first and second coating films 2 and 3. In case of using aluminum having a high reflectivity in a short-wavelength range as the first metal film and also having a problem of oxidation or corrosion due to an environment of high temperature and humidity or due to chemicals, if a precious metal material such as gold, platinum, or the like is used as the second coating film 3, it can function as a protective film for the aluminum. In case of making the second coating film 3 function only as a protective film, a nonmetal material also can be used. Furthermore, in case of mounting and using an optical probe on a scanning magnetic force microscope, a high-reflectance material such as aluminum, gold or the like is used as the first coating film 2, and a magnetic material such as chromium, nickel or the like or a magnetic alloy material is used as the second coating film 3.
According to the composition of the optical probe as shown in FIG. 2, it is possible to make small the tip diameter of the optical probe including the coating films and prevent a light from leaking through the circumference of the aperture and prevent the aperture from being buried. Therefore, it is possible to reconcile to each other improvement in resolution of a surface structure and improvement in resolution of optical characteristics. And it is possible to add a protective film or a functional film to the optical probe without enlarging its tip diameter including the coating films.
The composition of the optical probe as described above can be implemented in an optical probe whose tapered part is straight or in a optical probe whose tapered part is hook-shaped.
FIG. 3 is a process diagram showing a method for forming an aperture of the optical probe shown in the embodiment in FIG. 2. FIG. 3(A) shows a process of sharpening an optical fiber 1 and shows a sharpened optical fiber. The optical fiber 1 has its coating film of synthetic resin removed from it across the length of 1 cm to 10 cm from its end and is cleaned on the surface of it and then is sharpened. As a method for sharpening, a method using a tensile breaking process of breaking the optical fiber by applying a tension to the optical fiber as heating it by means of a heating means or using a chemical etching process is used. In a method of tensile breaking, as a heating means, a method of applying a condensed carbonic acid gas laser light to the optical fiber or a method of heating the optical fiber passing through in the middle of a coil of platinum wire by making an electric current flow in the platinum wire can be used. As a chemical etching method, a method of immersing the optical fiber 1 in a mixed solution of hydrofluoric acid and ammonium fluoride to utilize difference in an etching speed between the core and the cladding or a method of immersing the optical fiber 1 in a two-layer solution of hydrofluoric acid and organic solvent to sharpen the optical fiber as utilizing a meniscus of the two-layer interface is used.
In case of making an optical probe in the shape of a hook, after being sharpened the optical fiber is transformed into the shape of a hook bent by 60 to 90 degrees, where the angle before bending is assumed to be 0 degree, by applying a laser light of a carbonic acid laser to the part of the optical fiber of 0.1 mm to 2 mm distant from the sharpened tip. In this case, since the side irradiated with the laser light absorbs a larger amount of heat than its opposite side, the tip part of the optical fiber comes to be bent to the side irradiated with the laser light by a surface tension brought by softening. The bending angle can be adjusted by controlling the output of the laser light as confirming a bending condition.
In case of forming a reflecting plane for an optical lever, after forming the optical fiber into the shape of a hook, a reflecting plane is formed by machine-polishing on the rear face of the hook-shaped part.
FIG. 3(B) is a sectional view showing a process of depositing a first coating film 2 on the tip part except the aperture part of the optical fiber formed in the process shown in FIG. 3(A). As a method for depositing the first coating film 2, a thin film depositing method having anisotropy such as a vacuum evaporation process, a sputtering process or the like is used, and a film thickness in a range from 20 nm to 1000 nm is selected. As shown by an arrow in FIG. 3(B), the depositing direction is toward the tip from behind the tip part, and the angle A is selected in a range from 20 to 90 degrees. The optical fiber 1 is turned around the central axis 6 of the tip part during deposition of the coating film. In case of turning the optical fiber 1 around an axis 7 in parallel with the central axis 6 of the tip part, if an eccentric distance of rotation of the optical fiber 1 is small enough in comparison with its depositing distance, the same effect can be obtained as the case that the optical fiber is turned around the central axis 6 of the tip part. In case of not turning the optical fiber 1, deposition is performed separately from at least two directions around the central axis 6 of the tip part.
FIG. 3(C) is a sectional view showing a process of depositing a second coating film 3 which is formed into the shape of a taper in the vicinity of the tip part outside the first coating film 2. As a method for depositing the second coating film 3, in the same manner as the case of depositing the first coating film, a thin film depositing method having anisotropy such as a vacuum evaporation process, a sputtering process or the like is used, and a film thickness in a range from 20 nm to 1000 nm is selected. As shown by an arrow in FIG. 3(C), the depositing direction is toward the tip from behind the tip part, and the angle B is made smaller than the angle A shown in FIG. 2(B). The optical fiber 1 is turned around the central axis 6 of the tip part during deposition of the coating film. In case of turning the optical fiber 1 around an axis 7 in parallel with the central axis 6 of the tip part, if an eccentric distance of rotation of the optical fiber 1 is small enough in comparison with its depositing distance, the same effect can be obtained as the case that the optical fiber 1 is turned around the central axis 6 of the tip part. In case of not turning the optical fiber 1, deposition is separately and successively performed from at least two directions around the central axis 6 of the tip part.
According to a method for forming an aperture of an optical probe as shown in FIG. 3, it is possible to make a coating film with a first coating film forming the aperture part and a second coating film which is outside the first coating film and formed into the shape of a taper in the vicinity of the tip part.
FIG. 4 is an figure which shows the method for forming a aperture of a optical probe as shown by the embodiment in FIG. 1 and shows a layout inside an vacuum evaporation apparatus in a vacuum evaporation process for forming a aperture. In the same manner as the method explained in FIG. 3(A), a deposition boat 31 is set which has a finite length in the direction in parallel with the direction of the sharpened tip part of the optical fiber 1. At this time, the deposition boat 31 is disposed at a position where the end of it is not beyond the tip of the optical fiber 1. As turning the optical fiber 1 around the central axis of its tip part, deposition is performed by heating the deposition boat 31 with electric current. Paying attention to the tip part of the optical fiber 1, a metal coating film is deposited in a deposition angle in a range from angle C to angle D in FIG. 4. Accordingly, as shown by the embodiment in FIG. 1, a metal coating film can be formed which has a curved surface retreating gradually from the aperture part to the outer circumference at the end of the aperture part. In case of turning the optical fiber 1 around an axis 7 in parallel with the central axis 6 of the tip part, if an eccentric distance of rotation of the optical fiber 1 is small enough in comparison with the distance between the deposition boat 31 and the optical fiber 1, the same effect can be obtained as the case that the optical fiber 1 is turned around the central axis 6 of the tip part. In case of not turning the optical fiber 1, deposition is separately and successively performed from at least two directions around the central axis 6 of the tip part. The deposition boat 31, which is selected according to a material to be deposited, is made of ceramic, tungsten, alumina, or the like.
FIG. 5 is a figure which shows the method for forming an aperture of an optical probe as shown by the embodiment in FIG. 1 and shows a layout inside a vacuum evaporation apparatus in a vacuum evaporation process for forming an aperture.
This method is different in disposition of an evaporation source from the method for forming an aperture shown in FIG. 4. Two evaporation sources 32 are set in parallel with the direction of the sharpened tip part of the optical fiber 1. At this time, the first deposition boat 32 is disposed at a position where the end of it is not beyond the tip of the optical fiber 1. As turning the optical fiber 1 around the central axis of its tip part, deposition is performed by heating the evaporation sources 32. Paying attention to the tip part of the optical fiber 1, a metal coating film is deposited at the same time in two depositing directions of angle E and angle F in FIG. 5. Accordingly, as shown by the embodiment in FIG. 1, a metal coating film can be formed which has a curved surface retreating gradually from the aperture part to the outer circumference at the end of the aperture part. In case of turning the optical fiber 1 around an axis 7 in parallel with the central axis 6 of the tip part, if an eccentric distance of rotation of the optical fiber 1 is small enough in comparison with the distance between the deposition boats 32 and the optical fiber 1, the same effect can be obtained as the case that the optical fiber 1 is turned around the central axis 6 of the tip part. In case of not turning the optical fiber 1, deposition is separately and successively performed from at least two directions around the central axis 6 of the tip part.
Although a depositing method in which two evaporation sources 32 are disposed has been shown in FIG. 5, the same effect can be also by disposing two or more evaporation sources. As an evaporation source 32, a resistance heating evaporation source of tungsten, alumina, or the like or an electron beam evaporation source is used.
FIG. 6 shows the construction of a scanning near-field optical microscope using the optical probe of the invention. An optical probe 20 according to the present invention is set on a bimorph 21 which is a vibrating means, the tip of the optical probe 20 is vibrated vertically to a sample 23, and an atomic force or a force related to other interaction between the tip of the probe 20 and the surface of the sample 23 is detected by a displacement detecting means 22 as variation in the vibration characteristics of the probe 20. A topography is measured by scanning the sample by means of an XYZ moving mechanism 24, while controlling the optical probe 20 so as to keep constant the interval between its tip and the surface of the sample 23. At the same time, optical characteristics of a microscopic area of the sample are measured by introducing a light of a light source for measuring optical characteristics into the optical probe 20, applying the light to the sample 23 through the aperture of the tip of the probe 20, and detecting signals by means of an optical characteristics measuring light detecting means 27.
FIG. 6 shows a composition of a scanning near field optical microscope transmission type which detects a measuring light on the reverse face. A composition of a scanning near field optical microscope reflection type which detects a measuring light on the obverse face of the sample or to use a composition which detects a light by means of the optical probe 20 can get the same effect as the composition in FIG. 6.
FIG. 6 is an embodiment using an optical probe in the shape of a hook, the composition can also use an optical probe straight in shape. In a case of using a composition in which an optical probe straight in shape is used and the tip of the probe is vibrated horizontally to the surface of the sample 23, a scanning near-field optical microscope can be implemented which scans the sample while keeping constant the interval between the tip of the probe and the surface of the sample by utilizing a slipping force acting between the tip of the probe and the surface of the sample.
As described above, the composition of an optical probe of the invention can reduce an influence of thickness of the coating film upon a surface structure to be measured and make thicker the metal coating film in thickness by forming the metal coating film at the end part of the aperture into a curved surface. Therefore, it is possible to improve a topographic resolution. And since it is possible to prevent a light from leaking through the circumference of the aperture and prevent the aperture from being buried, it is possible to improve resolution and contrast of the optical image.
And the composition of an optical probe according to the invention can make small the tip diameter including a metal coating film of the optical probe and can improve the topographic resolution by using a coating film composed of the first coating film and the second coating film.
Furthermore, since the metal coating film is thicker rearwardly of the aperture, it is possible to prevent a light from leaking through the circumference of the aperture and prevent the aperture from being buried, and then it is possible to improve resolution and contrast of the optical characteristics.
And still further, according to a method for forming an aperture of an optical probe as described above, since it is possible to form a coating film into a curved surface at the end part of the aperture and make the metal coating film be composed of the first metal coating film forming the aperture and the second metal coating film which is outside the first metal coating film and is taper-shaped in the vicinity of the tip part, it is possible to easily form the aperture of an optical probe according to the invention. | An optical probe comprises a waveguide having an optical opening for passing light therethrough, the waveguide terminating in a sharp tip at a distal end thereof. A metal film is coated on the distal end of the waveguide except for the optical opening. The metal film has a curved surface gradually retreating from the optical opening to an outer circumference of the waveguide. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to decision-feedback equalization techniques, and more particularly, to techniques for determining a position of one or more offset latches employed for decision-feedback equalization.
BACKGROUND OF THE INVENTION
[0002] Digital communication receivers must sample an analog waveform and then reliably detect the sampled data. Signals arriving at a receiver are typically corrupted by intersymbol interference (ISI), crosstalk, echo, and other noise. In order to compensate for such channel distortions, communication receivers often employ well-known equalization techniques. For example, zero equalization or decision-feedback equalization (DFE) techniques (or both) are often employed. Such equalization techniques are widely-used for removing intersymbol interference and to improve the noise margin. See, for example, R. Gitlin et al., Digital Communication Principles, (Plenum Press, 1992) and E. A. Lee and D. G. Messerschmitt, Digital Communications, (Kluwer Academic Press, 1988), each incorporated by reference herein. Generally, zero equalization techniques equalize the pre-cursors of the channel impulse response and decision-feedback equalization equalizes the past cursors of the channel impulse response.
[0003] In one typical DFE implementation, a received signal is sampled and compared to one or more thresholds to generate the detected data. A DFE correction is applied in a feedback fashion to produce a DFE corrected signal. The addition/subtraction, however, is considered to be a computationally expensive operation. Thus, a variation of the classical DFE technique, often referred to as Spatial DFE, eliminates the analog adder operation by sampling the received signal using two (or more) vertical slicers that are offset from the common mode voltage. The two slicers are positioned based on the results of a well-known Least Mean Square (LMS) algorithm. One slicer is used for transitions from a binary value of 0 and the second slicer is used for transitions from a binary value of 1. The value of the previous detected bit is used to determine which slicer to use for detection of the current bit. For a more detailed discussion of Spatial DFE techniques, see, for example, Yang and Wu, “High-Performance Adaptive Decision Feedback Equalizer Based on Predictive Parallel Branch Slicer Scheme,” IEEE Signal Processing Systems 2002, 121-26 (2002), incorporated by reference herein. The offset position of the vertical slicers has been determined by evaluating an error term for a known receive data stream and adjusting the offset position using the well-known Least Mean Square algorithm. Such techniques, however, have been found to be unstable in a fixed point highly quantized signal environment and require excessive time to converge.
[0004] A need therefore exists for improved methods and apparatus for determining the desired offset position for the vertical slicers. A further need exists for methods and apparatus for determining the desired offset position for the vertical slicers based on an evaluation of the incoming data eye.
SUMMARY OF THE INVENTION
[0005] Generally, methods and apparatus are provided for determining a position of an offset latch employed for decision-feedback equalization. According to one aspect of the invention, a position of an offset latch employed by a decision-feedback equalizer is determined by obtaining a plurality of samples of a data eye associated with a signal, the data eye comprised of a plurality of trajectories for transitions out of a given binary state; determining an amplitude of at least two of the trajectories based on the samples; and determining a position of an offset latch based on the determined amplitudes. The initial position of the offset latch can be placed, for example, approximately in the middle of the determined amplitudes for at least two of the trajectories. The initial position of the offset latch can be optionally skewed by a predefined amount to improve the noise margin.
[0006] For example, the transitions out of a given binary state can be transitions out of a state of binary one and the at least two of the trajectories comprise a first trajectory associated with a transition to a value of binary one and a second trajectory having a maximum amplitude of the plurality of trajectories associated with a transition to a value of binary zero. When the transitions out of a given binary state are transitions out of a state of binary zero, the at least two of the trajectories comprise a first trajectory associated with a transition to a value of binary zero and a second trajectory having a minimum amplitude of the plurality of trajectories associated with a transition to a value of binary one.
[0007] A more complete understanding of the present invention, as well as further features and advantages of the present invention, will be obtained by reference to the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 graphically illustrates a number of ideal data eyes associated with a signal;
[0009] FIGS. 2A through 2D illustrate the distortion that can arise from a channel;
[0010] FIG. 3 is a block diagram of a transmitter, channel and receiver system that employs equalization techniques;
[0011] FIG. 4 is a block diagram of a transmitter, channel and receiver system that employs Spatial DFE;
[0012] FIG. 5 illustrates an exemplary transition trajectory from an exemplary binary value of 0 to a binary value of 0 or 1;
[0013] FIG. 6 illustrates the sampling of a signal using a data eye monitor in accordance with the present invention for a transition from a binary value of 1 to a binary value of 0 or 1;
[0014] FIG. 7 illustrates the sampling of a signal using a data eye monitor in accordance with the present invention for a transition from a binary value of 0 to a binary value of 0 or 1;
[0015] FIG. 8 illustrates one embodiment of the roaming latches of FIGS. 6 and 7 ; and
[0016] FIG. 9 is a flow chart describing an exemplary DFE offset latch positioning process incorporating features of the present invention.
DETAILED DESCRIPTION
[0017] The present invention provides methods and apparatus for determining the desired offset position for the vertical slicers. According to one aspect of the invention, the offset position for the vertical slicers is determined based on an evaluation of the incoming data eye. The exemplary data eye monitor may be implemented, for example, using the techniques described in U.S. patent application Ser. No. 11/095,178, filed Mar. 31, 2005, entitled “Method and Apparatus for Monitoring a Data Eye in a Clock and Data Recovery System,” incorporated by reference herein. Generally, one or more latches associated with the exemplary data eye monitor employ an envelope detection technique to evaluate the amplitude of the signal. For a discussion of suitable envelope detection techniques, see, for example, U.S. patent application Ser. No. 11/318,953, filed Dec. 23, 2005, entitled “Method and Apparatus for Adjusting Receiver Gain Based on Received Signal Envelope Detection,” (Attorney Docket No. Mobin 53-12-56), incorporated by reference herein.
[0018] FIG. 1 graphically illustrates a number of ideal data eyes 110 - 1 through 110 - 3 associated with a signal 100 . Although the ideal data eyes 110 shown in FIG. 1 do not exhibit any intersymbol interference for ease of illustration, each data eye 110 is typically a superposition of a number of individual signals with varying frequency components, in a known manner. As discussed below in conjunction with FIGS. 6 and 7 , two or more latches 640 -fixed and 640 -roam are used to evaluate the amplitude of each data eye 110 .
[0019] According to one aspect of the present invention, the amplitude of the received signal 110 can be determined based on the relative measurements of the two latches 640 -fixed and 640 -roam. The two latches 640 -fixed and 640 -roam are used to determine the upper and lower bounds of the signal, for transitions from binary 1 and for transitions from binary 0. The offset latches are then positioned based on the respective upper and lower bounds of the signal. For example, the offset latches can be positioned in the middle of the respective upper and lower bounds of the signal. In one variation discussed further below, the offset latches are positioned in a location that is skewed in time or amplitude (or both) from the middle position, based on one or more predefined criteria, for improved noise margining.
[0020] As discussed further below in conjunction with FIG. 9 , in one exemplary embodiment, the data eye monitor measures the received signal 110 along the vertical axis to determine the location of the upper and lower bounds of the signal, for both cases of transitions from binary values of 1 and 0. Thereafter, the mid-point between the upper and lower bounds is established for both cases. The offset latches for both cases can be positioned based on the determined mid-point locations.
[0021] FIGS. 2A through 2D further illustrate the distortion that can arise from a channel. As shown in FIG. 2A , an ideal channel exhibits a delta function 200 as its impulse response. FIG. 2B illustrates an exemplary frequency response 210 for a hypothetical channel. As shown in FIG. 2B , in the frequency domain, the hypothetical channel may exhibit an frequency response having a magnitude of 1.0 at the primary tap 220 . In addition, at a first post cursor tap 230 the hypothetical channel may exhibit a frequency response having a magnitude of 0.5. Thus, for this example, in the time domain, 50% of the signal will spillover and affect the next time interval.
[0022] FIG. 2C illustrates an ideal clock signal 230 that may be transmitted across a channel. FIG. 2D illustrates the clock signal 250 that is received over the same channel as the result of channel distortion (after a sample/hold is applied). As shown in FIG. 2C , in each subsequent time slot, values of +1, +1, −1, −1, +1, +1, −1, −1, are transmitted to generate the clock signal 230 . Assuming a channel having the exemplary impulse response 210 of FIG. 2B , and no channel compensation, the receiver will sample the signal 250 shown in FIG. 2D . The +1 that is transmitted in the second time slot will be superimposed with 50% of the +1 that was transmitted in the first time slot. Thus, a value of +1.5 will be measured at the receiver in the second time slot. Generally, one or more of pre-emphasis techniques in the transmitter or equalization techniques in the receiver (or both) are employed in a well-known manner so that the signal processed by the receiver looks like the clock signal 230 that was transmitted.
[0023] FIG. 3 is a block diagram of a transmitter, channel and receiver system 300 that employs equalization techniques. As shown in FIG. 3 , the data is transmitted by a transmitter 310 through a channel 320 after optionally being equalized or filtered through a transmit FIR filter (TXFIR) (not shown). After passing though the channel 320 , where noise is introduced, as represented by adder 330 , the signal may optionally be filtered or equalized by a continuous time feed forward filter 340 . Generally, the feed forward filter 340 performs pre-cursor equalization to compensate for the spillover from future transmitted symbols, in a known manner. The analog signal out of the feed forward filter 340 is sampled by a data detector 360 that generates data decisions.
[0024] A DFE correction generated by a DFE filter 370 is applied to an analog summer 350 from the output, U k , of the feed forward filter 340 to produce a DFE corrected signal, B k .
[0025] FIG. 4 is a block diagram of a transmitter, channel and receiver system 400 that employs Spatial DFE. As indicated above, Spatial DFE is a variation of the classical DFE technique shown in FIG. 3 that eliminates the analog adder by sampling the received signal using two vertical slicers that are offset from the common mode voltage.
[0026] As shown in FIG. 4 , pre-emphasis techniques 410 are applied in the transmitter before the signal is transmitted over a channel 420 . In addition, equalization techniques 430 , such as zero equalization, and spatial DFE 440 are applied in the receiver. According to one aspect of the invention, a cross over monitor 800 , discussed below in conjunction with FIG. 8 , implements a DFE offset latch positioning process 900 , discussed below in conjunction with FIG. 9 , to determine the position of the offset latches employed by the spatial DFE 440 . When pre-emphasis techniques 410 are applied in the transmitter, the output of the cross over monitor 800 is fed back to the transmitter using an in-band or out of band protocol 450 .
[0027] As previously indicated, each data eye 110 is a superposition of a number of individual signals with varying frequency components, in a known manner. The signal associated with different data transitions will have a different frequency. FIG. 5 illustrates an exemplary transition trajectory for an exemplary transition from a binary value of 0 to a binary value of 0 or 1. A trajectory 510 , for example, is associated with a transition from a binary value of 0 to a 1 (and then followed by another 1). A trajectory 530 , for example, is associated with a transition from a binary value of 0 having prior states 000 to a binary value of 1 (followed by a 0). A trajectory 540 is associated with a transition from a binary value of 0 having prior states 000 to a binary value of 0.
[0028] As shown in FIG. 5 , the different trajectories are all associated with a prior state of 0. Each trajectory, however, follows a different path. In accordance with the Spatial DFE technique 440 , a single offset latch 550 must be able to detect whether the current data bit is a 0 or a 1, despite the varying paths. Generally, the offset latch 550 is positioned between the negative rail margin 560 and the amplitude of the lowest expected trajectory 530 . According to the present invention, the data eye monitor 800 is used to determines a location for the offset latch 550 used for the spatial DFE 440 .
[0029] FIG. 6 illustrates the sampling of a signal using a data eye monitor in accordance with the present invention for a transition 630 from an initial state 610 of binary value 1 to a binary value of 0 or a transition 620 from a binary value of 1 to a binary value of 1. For ease of illustration, only the trajectory 630 associated with the Nyquist frequency and the trajectory 620 associated with the maximum amplitude of the remaining frequencies are shown. As discussed below in conjunction with FIG. 8 , two latches 640 -fixed and 640 -roam are employed in the exemplary embodiment to determine the amplitudes of the trajectories 620 , 630 and thereby determine a location for the latches used for the spatial DFE 440 . It is noted that a plurality of roaming latches 640 -roam can optionally be employed for quicker detection.
[0030] FIG. 7 illustrates the sampling of a signal using a data eye monitor in accordance with the present invention for a transition 730 from an initial state 710 of binary value 0 to a binary value of 0 or a transition 720 from a binary value of 0 to a binary value of 1 and then a binary value of 0. For ease of illustration, only the trajectory 720 associated with the Nyquist frequency and the trajectory 730 associated with the minimum amplitude of the remaining frequencies are shown. As discussed below in conjunction with FIG. 8 , the same two latches 640 -fixed and 640 -roam of FIG. 6 can be employed in the exemplary embodiment to determine the amplitudes of the trajectories 720 , 730 and thereby determine a location for the latches used for the spatial DFE 440 .
[0031] FIG. 8 illustrates one embodiment of the roaming latches of FIGS. 6 and 7 . Generally, the two latches 640 -fixed and 640 -roam are used to determine the amplitude of the two trajectories of interest for both cases of transitions from binary 0 and transitions from binary 1. The fixed latch 640 -fixed is fixed at approximately the center of the amplitude range. The roaming latch 640 -roam samples the signal along the vertical axis by varying the threshold voltage of the roaming latch 640 -roam. In one exemplary implementation, the roaming latch 640 -roam is stepped through each of N horizontal positions associated with a given eye, by varying the phase of the applied clock. Once the zero crossing points are identified, the midpoint associated with the center of the data eye can be established. The fixed latch 640 -fixed is then fixed at the midpoint (time-wise and amplitude-wise). Generally, the timing of the latch 640 is fixed time-wise approximately centered between the zero crossings and is fixed amplitude-wise by of the threshold of the latch 640 to the common mode of the incoming signal. The roaming latch 640 -roam is then stepped through each of M vertical levels of the determined middle point to measure the amplitude of the two trajectories of interest for both cases.
[0032] As shown in FIG. 8 , the outputs of the two latches 640 -fixed and 640 -roam of FIGS. 5 and 6 are applied to an exclusive OR (XOR) gate 830 . The XOR gate 830 compares the value of the two latches 640 -fixed and 640 -roam. If the values of the two latches 640 -fixed and 640 -roam match, the XOR gate 830 will generate a binary value of 0 and if the values of the two latches 640 -fixed and 640 -roam do not match, the XOR gate 830 will generate a binary value of 1. Thus, a “hit” occurs in the exemplary embodiment when the values of the two latches 640 -fixed and 640 -roam do not match.
[0033] The relative values of the two latches 640 -fixed and 640 -roam provide an indication of location of the two trajectories of interest for both cases. If the two latches 640 -fixed and 640 -roam have the same value, they are said to match. Thus, for samples taken inside a data eye (i.e., within the two trajectories of interest for each case), it would be expected that the value of the two latches 640 -fixed and 640 -roam match one another. For samples taken along the boundary of the data eye (within the multiple trajectories associated with a transition), it would be expected that some of the values of the two latches 640 -fixed and 640 -roam will match one another. For samples taken outside a data eye, it would be expected that all values of the two latches 640 -fixed and 640 -roam will not match. Thus, the inner eye is detected by the fully matching case (the output of the XOR 830 is all zeros) and the outer eye is detected by the fully mismatching case (the output of the XOR 830 is all ones) Thus, the number of samples taken outside the eye provides an indication of the maximum hit count.
[0034] In the exemplary embodiment of FIG. 8 , the output of the XOR 630 is processed by an offset latch position determination stage 840 . As previously indicated, the XOR 830 will generate a binary value of 0 when the outputs of the two latches 640 -fixed and 640 -roam match, and will generate a binary value of 1 when the outputs of the two latches 640 -fixed and 640 -roam do not match. Thus, binary values of 1 will be expected when the roaming latch 640 -roam is sampling in the locations of the trajectories of interest.
[0035] FIG. 9 is a flow chart describing an exemplary DFE offset latch positioning process 900 incorporating features of the present invention. As shown in FIG. 9 , the exemplary DFE offset latch positioning process 900 initially measures the signal 110 along the vertical axis during step 910 to determine the location of the upper and lower bounds, for both cases of transitions from binary values of 1 and 0. Thereafter, during step 920 the mid-point between the upper and lower bounds is established for both cases.
[0036] Optionally, the mid-point determined during step 920 can be skewed to the left during step 930 in time for improved noise margining. Thus, by shifting the latch by a predefined percentage to the left of center, the timing and voltage margin is improved.
[0037] A plurality of identical die are typically formed in a repeated pattern on a surface of the wafer. Each die includes a device described herein, and may include other structures or circuits. The individual die are cut or diced from the wafer, then packaged as an integrated circuit. One skilled in the art would know how to dice wafers and package die to produce integrated circuits. Integrated circuits so manufactured are considered part of this invention.
[0038] While exemplary embodiments of the present invention have been described with respect to digital logic blocks, as would be apparent to one skilled in the art, various functions may be implemented in the digital domain as processing steps in a software program, in hardware by circuit elements or state machines, or in combination of both software and hardware. Such software may be employed in, for example, a digital signal processor, micro-controller, or general-purpose computer. Such hardware and software may be embodied within circuits implemented within an integrated circuit.
[0039] Thus, the functions of the present invention can be embodied in the form of methods and apparatuses for practicing those methods. One or more aspects of the present invention can be embodied in the form of program code, for example, whether stored in a storage medium, loaded into and/or executed by a machine, or transmitted over some transmission medium, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. When implemented on a general-purpose processor, the program code segments combine with the processor to provide a device that operates analogously to specific logic circuits.
[0040] It is to be understood that the embodiments and variations shown and described herein are merely illustrative of the principles of this invention and that various modifications may be implemented by those skilled in the art without departing from the scope and spirit of the invention. | Methods and apparatus are provided for determining a position of an offset latch employed for decision-feedback equalization. The position of an offset latch is determined by obtaining a plurality of samples of a data eye associated with a signal, the data eye comprised of a plurality of trajectories for transitions out of a given binary state; determining an amplitude of at least two of the trajectories based on the samples; and determining a position of an offset latch based on the determined amplitudes. The initial position of the offset latch can be placed, for example, approximately in the middle of the determined amplitudes for at least two of the trajectories. The initial position of the offset latch can be optionally skewed by a predefined amount to improve the noise margin. | 7 |
FIELD OF THE INVENTION
This invention is related to the field of polymers, wherein said polymers comprise polymerized ethylene.
BACKGROUND OF THE INVENTION
The process of making polymers and the process of using polymers is a multi-billion dollar business. This business produces and uses billions of pounds of polymers each year. Millions of dollars have been spent on developing technologies that can add value to this business. This is because of the large scale economics that are involved. That is, even small improvements in these processes can add millions of dollars to the bottom line. Consequently, research is on-going to find new and useful ways to produce these polymers and new and useful ways to use these polymers.
It is known in the art that increasing the long chain branching level (e.g. via crosslinking) of a polymer, where said polymer comprises polymerized ethylene, results in an increase in the haze of films obtained from blown film. Additionally, it is known that crosslinking such polymers substantially decreases their use in film applications because such crosslinking substantially decreases the dart impact, TD tear resistance, and gloss, of the film.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a process to produce a composition.
It is another object of this invention to provide said composition.
In accordance with this invention a process to produce a composition is provided. This process comprises (or optionally, “consist essentially of”, or “consists of”) reacting: (a) at least one polymer component; with (b) at least one reactive component; to produce a composition.:
In accordance with this invention a composition is provided. Said composition comprises (or optionally, “consist essentially of”, or “consists of”) said composition produced by said process.
These objects and other objects will become more apparent from the following.
The terms “comprise”, “comprises” and “comprising” are open-ended and do not exclude the presence of other steps, elememts, or materials that are not specifically mentioned in this specification.
The phrases “consists of” and “consisting of” are closed ended and do exclude the presence of other steps, elements, or materials that are not specifically mentioned in this specification, however, they do not exclude impurities normally associated with the elements and materials used.
The phrases “consists essentially of” and “consisting essentially of” do not exclude the presence of other steps, elements, or materials that are not specifically mentioned in this specification, as along as such steps, elements, or materials, do not affect the basic and novel characteristics of the invention, additionally, they do not exclude impurities normally associated with the elements and materials used.
The above terms and phrases are intended for use in areas outside of U.S. jurisdiction. Within the U.S. jurisdiction the above terms and phrases are to be applied as they are construed by U.S. courts and the U.S. Patent Office.
DETAILED DESCRIPTION OF THE INVENTION
The polymer component comprises a polymer. This polymer comprises polymerized monomers. These monomers are selected from the group consisting of ethylene and one or more alpha-olefins.
The alpha-olefins useful in this invention have from 3 to 12 carbon atoms. However, it is preferred when such alpha-olefins have from 3 to 10 carbon atoms, and it is most preferred when such alpha-olefins have from 4 to 8 carbon atoms. Suitable examples of such alpha-olefins are propene, 1-butene, 3-methyl-1-butene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 3-ethyl-1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene. Mixtures of alpha-olefins can be used in this invention.
The polymer needs to be produced by a metallocene catalyst. For the purposes of this invention, metallocene catalysts are defined as those catalysts claimed on the issue date, in U.S. Pat. No. 5,498,581, which is entitled “Method for Making and Using a Supported Metallocent Catalyst System” and which issued on Mar. 12, 1996. The entire disclosure of U.S. Pat. No. 5,498,581, is hereby incorporated by reference. A suitable, and preferred, metallocene catalyst is ((9-fluorenyl) (cyclopentadienyl) (methyl) (3-butenyl) methane) zirconium dichloride.
The polymer has a density from about 0.90 to about 0.95 grams per cubic centimeter. However, it is preferable when the density is from about 0.91 to about 0.93, and it is most preferable when the density is from 0.915 to 0.925 grams per cubic centimeter. This density is measured in accordance with ASTM D 1505.
The polymer has a melt index from about 0.1 to about 5 grams per ten minutes. However, it is preferable when the melt index is from about 0.3 to about 3, and it is most preferable when the melt index is from 0.5 to 2.5 grams per ten minutes. This melt index is measured in accordance with ASTM D 1238, condition F.
The polymer has a heterogeneity index from about 2 to about 3. However, it is preferable when the heterogeneity index is from about 2.1 to about 2.7, and it is most preferable when the heterogeneity index is from 2.2 to 2.5. This heterogeneity index is measured using gel permeation chromatography.
The reactive component can be any suitable crosslinking agent that crosslinks such polymers. However, it is preferred if the crosslinking agent is an organic peroxide crosslinking agent. For example, diperoxy compounds can be employed as the crosslinking agents. Examples of diperoxy compounds suitable for use as crosslinking agents include acetylenic diperoxy compounds such as hexynes having the formula
octynes having the formula
and octadiynes having the formula
wherein R is selected from the group consisting of tertiary alkyl, alkyl carbonate, and benzoate. The molecular weights of the compounds are generally in the range of from about 200 to about 600. Examples of acetylenic diperoxy compounds described above include:
2,7-dimethyl-1,7-di(t-butylperoxy)octadiyne-3,5;
2,7-dimethyl-2,7-di(peroxy ethyl carbonate)octadiyne-3,5;
3,6-dimethyl-2,6-di(peroxy ethyl carbonate)octyne-4;
3,6-dimethyl-2,6-di(t-butylperoxy)octyne-4;
2,5-dimethyl-2,5-di(peroxybenzoate)hexyne-3;
2,5-dimethyl-2,5-di(peroxy-n-propyl carbonate)hexyne-3;
2,5-dimethyl-2,5-di(peroxy isobutyl carbonate)hexyne-3;
2,5-dimethyl-2,5-di(alpha-cumyl peroxy)hexyne-3;
2,5-dimethyl-2,5-di(peroxy ethyl carbonate)hexyne-3;
2,5-dimethyl-2,5-di(peroxy beta-chioroethyl carbonate)hexyne-3; and
2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3.
Other diperoxy compounds suitable for use as the crosslinking agent of the composition of the present invention include hexanes having the formula
and octanes having the formula
wherein R is selected from the group consisting of tertiary alkyl, alkyl carbonate, and benzoate. The molecular weights of the compounds are generally in the range of from about 200 to a bout 600. Examples of diperoxy compounds described above include:
3,6-dimethyl-2,6-di(t-butylperoxy)octane;
3,6-dimethyl-2,6-di(peroxy ethyl carbonate)octane;
2,5-dimethyl-2,5-di(peroxybenzoate)hexane;
2,5-dimethyl-2,5-di(peroxy isobutyl carbonate)hexane; and
2,5-dimethyl-2,5-di(t-butylperoxy)hexane.
Preferably, the diperoxy compound employed as the crosslinking agent of the composition of the present invention is selected from the group consisting of 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3 and 2,5-dimethyl-2,5-di(t-butylperoxy)hexane. Other suitable example of crosslinking agents are disclosed in U.S. Pat. Nos. 3,214,422 and 4,440,893 the entire disclosures of which are hereby incorporated by reference.
It should be noted that the amount of “active oxygen” in a crosslinking agent can significantly affect the amount of agent to use. The term “active oxygen” is well known in the art. In general, it means the active (—O—O—) bonds in a molecule. The amount of active oxygen that should be used in this invention is from about 0.1 to about 20 parts per million by weight based on the weight of the polymer. Preferably, the amount of active oxygen that should be used in this invention is from about 1 to about 15 parts per million by weight based on the weight of the polymer. More preferably, the amount of active oxygen that should be used in the invention is from about 2 to about 14 parts per million by weight based on the weight of the polymer and most preferably from 3 to 13 parts per million by weight based on the weight of the polymer.
The polymer component and the reactive component are reacted at a temperature and pressure to crosslink the polymer. It is believed that some of the polymer chains are broken by the reactive component. These broken polymer chains are then coupled with another polymer chain such that a single polymer chain is made. This single polymer chain contains long chain branching due to the formerly broken, now coupled, polymer chain. It is preferred when the reactive component is dispersed or diluted prior to crosslinking in order to make a more uniform crosslinkable composition and to prevent localized/concentrated crosslinking that will produce gels in film.
In general, the temperature should be from about 160° C. to about 300° C., preferably from about 190° C. to about 270° C. and most preferably from 200° C. to 260° C.
In general, the composition has a shear ratio (HLMI/MI) from about 18 to about 40. However, it is preferred when the shear ratio is from about 20 to about 30.
EXAMPLES
These examples are provided to illustrate the invention. They are not meant to limit the reasonable scope of the invention.
The polymer component use in these examples contained a polymer that was produced in accordance with U.S. Pat. No. 5,498,581, using a metallocene catalyst named ((9-fluorenyl)(cyclopentadienyl)(methyl)(3-butenyl)methane)zirconium dichloride. It had a density of about 0.92 grams per cubic centimeter and a heterogeneity index of about 2.3.
The reactive component was Lupersol 101 which contains 2,5-dimethyl-2,5-di-(t-butyl peroxy)hexane, and which had an active oxygen content of 10.03-10.25 weight percent.
The polymer component and the reactive component were blended together to form a mixture. This mixture was then extruded to form the composition. The composition was then used to produce 1 mil gauge film.
The film was made on 4 inch Sano LLDPE blown film line using standard film blowing conditions. The following conditions were used: a 4 inch LLDPE die with an 0.060 inch gap, 60 pounds per hour feed rate (about 115 RPM), 2.5:1 blow-up ratio, and an “in pocket” bubble. The barrel temperature and the die set temperatures were 190° C.
The results are presented in Table One.
These results are unexpected. In particular, the haze actually decreased in value, this is most unexpected considering the fact that it has been concluded that the haze of LDPE (which also has long chain branching) increases as the number of long chain branches in the polymer increases. 1
1 Ferdinand C. Stehling, C. Stanley Speed, and Lowell Westerman, Causes of Haze of Low-Density Polyethylene Blown Films, Macromolecules 1981, 14, 698-708.
TABLE 1
Example #
HLMI 2
MI 3
HLMI\MI
R. C. 4
D. Impact 5
S. Impact 6
TD Tear 7
Haze 8
1
32.2
1.92
16.8
0
602
0.848
442
14.5
2
26.87
1.38
19.5
60
606
0.945
459
11.3
3
22.71
0.93
24.4
115
630
1.042
427
11.1
4
18.74
0.62
30.2
180
572
0.869
486
13.4
2 This is the High Load Melt Index in grams per 10 minutes. It was determined in accordance with ASTM D 1238 Condition E.
3 This is the Melt Index in grams per 10 minutes. It was determined in accordance with ASTM D 1238 Condition F.
4 This is the amount of reactive component used in preparing the composition in part per million, based on the weight of the polymer.
5 This is the Dart Impact in grams. It was determined in accordance with ASTM D 1709 Method A.
6 This is the Spencer Impact in Joules. It was determined in accordance with ASTM D 3420.
7 This is the TD Tear in grams. It was determined in accordance with ASTM D 1922.
8 This was measured in accordance with ASTM D 1003. | A process comprising reacting at least one polymer component, with at least one reactive component, to produce a composition, the polymer being a metallocene polymerized ethylene (co)polymer, and the reactive component being a crosslinking agent. | 2 |
[0001] 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.
BACKGROUND
[0002] 1. Development of the Side-by-Side Flexible Twin Bicycle
[0003] Bicycling is an efficient means of transportation and one of the easiest ways to exercise with many health benefits including improvement in cardio-vascular fitness and stamina. But bicycling is not free of dangers.
[0004] According to Schwab (2012) “A quarter of all fatalities and half of all seriously injured in traffic in the Netherlands are bicyclists, . . . more alarming is that in the last 10 years the number of seriously injured bicyclists is steadily increasing. This increase is for a large part among the elderly, where the types of accidents are so-called single vehicle accidents. The bicyclist is not hit by a car or a bus, he just falls over. One aspect of this falling over can be attributed to the stability of the vehicle, the bicycle.”
[0005] As an alternative to overcome this safety concern, in December 2012, I joined two Schwinn® Drifter 26″ bicycles (one man, one woman) rigidly side-by-side in parallel. The resulting side-by-side rigid twin bicycle is similar to what is known as a “Quadracycle”.
[0006] The benefits of riding a side-by-side rigid twin bicycle include the vertical stability that reduces the likelihood of falls, dual steering controls that can be shared or alternated between riders, the ability of one rider to pedal or apply brakes while the other rests, and most enjoyable, the social ability to hold a conversation while pedaling at a leisure pace.
[0007] However, the side-by-side rigid twin bicycle has also the constraints and limitations of the quadracycle. Quadracycles, (“All about bicycles,” n.d.) “have some stability issues, and it is not usually advised to take corners at superior speeds. The passengers need to shift their weight in order to keep the vehicle on the road.” This stability issue while cornering is related to the quadracycle's inability to lean into turns as regular bicycles do.
[0008] Another limitation of quadracycles is that they ride best in a straight line and on even and level surfaces. When turning into a surface of different elevation or inclination, for example when going from the road into an inclined carport ramp, if the approach to the ramp is at an angle, the quadracycle will ride on three tires over the transition. When one tire looses contact with the ground, due to the differences in elevation or inclination, the quadracycle frame to undergo bending and twisting stresses that can compromise its integrity and eventually result in failure due of metal fatigue.
[0009] In August 2013, not satisfied with the limitations of the side-by-side rigid twin bicycle, I started design of various mechanisms for joining the two bicycles in a flexible manner to avoid the limitations of the rigid quadracycle and allow each bicycle to lean into turns and to pitch and surge to conform to bumps or hollows and differences in elevation in its path, while retaining the vertical stability of the side-by-side rigid twin bicycle.
[0010] During September 2013 I developed various design geometries in a 3D CAD program for connecting two bicycles in parallel with pivoted link bars. I selected four horizontal link bars with spherical rod end bearings to connect the two bicycle frames in such a way as to form a flexible box type assemblage with the objective of minimizing deviations of the bicycle frames from parallel. The spherical rod end bearings are commercially available at various sizes and configurations and are used when a precision articulating joint is required.
[0011] The initial 3D CAD design effort also included the use of longitudinal torsion bars, compound torsion bars, or vertical diagonal compression springs mounted on concentric tubes to maintain the flexible side-by-side twin bicycle assemblage upright when at rest and still allow for lean, pitch and surge while riding.
[0012] I desired to locate the link bar pivot points as near as possible to each bicycle frame centerline. This was to form, in front view, a rectangle with pivoting corners that would fold into a parallelogram, reasoning that said assemblage would not impose bending stresses on the bicycle frames when it leaned into a turn or when it was twisted around the transverse axis when riding over uneven surfaces. Two of the link bars would be located on the front attached at the top and bottom of the head tube of each bicycle. The other two link bars were located at the rear; one connecting seat tubes near the base of the seats, and the other near the rear wheels hubs. The pivot points of the rear bottom link bar had to be located away from the centerline of the frame to clear the wheel hub and chain mechanism and it was not clear if this deviation from the vertical center plane was possible without introducing bending or twisting stresses on the bicycle frames.
[0013] To verify the effect of locating the rear bottom link bar pivots away from the vertical center plane I did graphic simulation of the motions in the 3D CAD program. This simulation consisted of leaning, rotating and moving each CAD model bicycle and then rotating the links on the vertical and horizontal planes centered on one of the pivot points to move the other end of the link as near as possible to its initial pivot point on the other bicycle. This simulation proved to be difficult due to the complexity in motion of the different components in 3D.
[0014] I found that, after completing a number of iterations, there was always an error in that at least one end of one of the link bars would not fall exactly on its corresponding pivot point. This meant that on an actual assemblage, when said assemblage was leaned into a turn, each of the four link bars would be either in tension or compression. This would impose bending and twisting stresses on each bicycle frame that could eventually result in metal fatigue failures. This is probably one of the reasons why, to my knowledge, there is no functionally successful side-by-side flexible twin bicycle prior art.
[0015] As I continued development of the concept I discovered several other reasons why prior art may have also failed, these reasons are discussed later.
[0016] To overcome said twisting and bending problem I initially considered mounting one or more link bars with pivot points supported on compression springs to allow the pivot point to move against the springs and relieve some of the tension or compression force to reduce the frame bending or twisting stresses to acceptable levels. But this represented an undesirable mechanical complexity and the uncertainty that the assemblage would not maintain proper alignment under all lean, pitch and surge motions. The construction of pivot points mounted with compression springs is discussed in the detailed description section related to FIGS. 2 g and 2 h that describe the horizontal diagonal link bars 420 a and 420 b.
[0017] I came up with the hypothesis that if the four pivot points of each bicycle frame were located on the same plane, a plane not necessarily on the bicycle frame centerline, independent of the resulting difference between link bar lengths, it might reduce or eliminate the error that at least one link bar end would not fall exactly on its corresponding pivot point. The pivot point plane of each bicycle on said assemblage would look like an inclined “V” shape both in front view and in top view. If said hypothesis was true there would be no bending or twisting stresses imposed on the bicycles frames when said assemblage was leaned into a turn or when it rode over an uneven path.
[0018] In October 2013 I built a 5/8-scale wood model employing ¼″ spherical rod end bearings to test said hypothesis and found that, although the motions of the assemblage were very complex, the 5/8-scale wood model could be folded around the longitudinal axes of the pivot points until it collapsed flat and could also be twisted around the transverse axis of the assemblage to the limit afforded by the spherical rod end bearings without appreciable resistance. This test confirmed the hypothesis a coplanar pivot point geometry, that is, all pivot points of each bicycle frame located on an inclined plane, independent of the difference between link bar lengths, avoided the introduction of bending and twisting stresses on the bicycles frames. Details of the 5/8-scale wood model construction and the twisting and folding tests are explained in the detailed description of example embodiments.
[0019] From November 2013 to January 2014 I fabricated the components to modify the two rigid bicycles into a side-by-side flexible twin bicycle assemblage following coplanar pivot point geometry. Instead of using four link bars as originally planned I used three by substituting the two front link bars on the head tube with one link bar in the middle of the head tube. The reasoning for this change was that three points in space always define a unique plane; the pivot points on three links would always fall on the same plane independent of errors in fabrication.
[0020] I started testing of the first prototype early in February 2014 and immediately encountered two problems that rendered the assemblage unrideable. The first problem was progressive misalignment and excessive scrubbing of the front tires even when attempting just to run on a straight line. I initially attributed this to misalignment of the bicycle frames but, after several trials adjusting the length of the link bars to improve the alignment, I realized that this problem was due to twisting of the bicycle frames. The details of this problem are explained in the detailed description of example embodiments. I replaced the single front link bar on the head tube with two link bars, one installed above the top tube and the second below the bottom tube. These two link bars provided enough rigidity to reduce the twisting of the frames to be essentially imperceptible.
[0021] The second problem was related to the use of springs mounted on concentric tubes intended to maintain the flexible assemblage upright when at rest but allow for leaning into turns. I found that these springs interfered with the ability to lean into turns and maintain a constant turn radius. I also found that, after removing the springs, the turning behavior of the assemblage was similar to that of a standard single bicycle. Difficulties with springs intended to maintain the flexible assemblage and riders upright when at rest and while riding in a straight line will be explained later in the detailed description section. Essentially all previous art employs springs for this purpose and this is probably another reason why previous art has not been successful.
[0022] I refer to the modified assemblage with the four link bars and without springs as the second prototype. I started testing the second prototype early in March 2014 and found that it satisfied the performance conditions desired. The second prototype of the Side-by-Side Flexible Twin Bicycle maintains the benefits of the original rigid side-by-side twin bicycle while avoiding the constraints of the rigid quadracycle. The flexible attribute refers to the ability of the assemblage to be simultaneously or independently operated by one or more driver riders and, while providing the vertical stability of a four-wheel vehicle, allow for the simultaneous leaning in order to enter, execute and exit from turns in a manner similar to riding a typical single bicycle; allows for pitching around the transverse axis to conform to bumps or hollows in the riding path of each bicycle and allows for the independent vertical surge of each bicycle to conform to differences in elevation in the riding path while maintaining a relative parallel position between each bicycle.
[0023] 2. Prior Art
[0024] According to Pressman (2012), “more patents issue on bicycles than anything else”. Judging from the number of patents in the prior art cited below, there has been an intense interest for over a century to develop a viable side-by-side parallel twin bicycle. Multiple designs of rigid and semi rigid assemblies have been proposed, some with the ability to roll around the longitudinal axis, others with the ability to rotate or pitch around the transverse axis and yet others with the ability to allow for vertical surge of each bicycle.
[0025] There is a smaller number that have claimed the ability to combine the movements of roll, pitch and surge in one embodiment.
[0026] Notwithstanding the number of designs for side-by-side flexible twin bicycles proposed, the lack of a successful, commercially viable flexible twin bicycle with the ability to combine the movements of roll, pitch and surge in one embodiment hints at a number of shortcomings inherent in those designs that to our knowledge have not been overcome by anyone of the previous designs proposed. A tabulation of some U.S. patents prior art is included in Table 1 on page 46.
[0027] The fourth column in table 1 includes comments related to shortcomings of the particular prior art embodiment. Some of these shortcomings are evident upon close examination of the figures and the corresponding description of the operation. For example, the “unintentional rigid assemblage” in Riess (1892) relates to torsion springs located in the middle of otherwise unpivoted link bars and the “unintentional rigid assemblage” in Pomerance (1974) is due to a rigid link bar to coordinate the steering of the two bicycles that is connected directly to the inside tips of the center hub of the front tires (FIG. 8b). The Pomerance (1974) arrangement results in an unsteerable assemblage since when a bicycle is steered the tips of the hub of the front tire follow arc trajectories in opposite directions that that rigid link bar would not allow.
[0028] Other shortcomings are not evident and were discovered after several attempts to correct related problems during testing of the first prototype. Identifying the root cause of the problem required some additional testing, close observation and modifications. One example is the longitudinal flexing and twisting of individual bicycle frames due to lateral loads from road-induced deformation of tires. I experienced this problem when testing the first prototype and initially attributed it to misalignment of the bicycles. But after several efforts to get the alignment right failed to resolve the problem I concluded that misalignment was an aggravating factor but not the root cause.
[0029] This problem was related to the use of a single link bar on the front of the first prototype that, in combination with the two bicycle frames, did not provide the rigidity anticipated. Bicycle frames are triangulated tubular structures that are extremely strong resisting vertical loads. A sudden lateral force on a single bicycle results in falling to the side and is promptly corrected by the rider by “steering into the fall”. The resulting lateral stress on the frame of that single bicycle is not significant. This is not the case when two bicycles are joined together in parallel.
[0030] When two bicycles are joined together in parallel the reaction to lateral forces is not that clear since the system is designed “not to fall” and each frame can induce stresses on the other. It seems that all inventors, I included, unconsciously assumed that the structure would be relatively rigid and exposed to minimal lateral forces. That is not the case as will be explained later in the discussion of the operation of the first prototype.
[0031] There are prior art embodiments that employ a single link element at the front, for example Chin et al. (2012), and it is claimed this maintains perfect parallel position when the horizontal (lateral) bending torques from the auxiliary tire would probably bend and deform the single link element at the pivot points. There are embodiments with two link elements, one at the front, the other at the rear, for example Underhaug (2010), Pomerance (1974), Ferrary (1967), that are also claimed to maintain perfect alignment, but the bending torques around the longitudinal axis formed by the pivot points of said link elements combined with the lever arms from the longitudinal axes to the contact points of the tires with the road, will probably tend to bend and twist the individual frames and spread or narrow the track of said assemblies.
[0032] Another unobvious shortcoming discovered during prototype testing relates to the turning behavior of embodiments that employ springs or other resilient (“sprung”) components to keep the assemblage and riders in a vertical position while “allowing for leaning into turns and to accommodate for bumps or differences in road elevations.” The behavior of these sprung embodiments is not as I had anticipated. This will be explained later in the section discussing the operation of the first and second prototypes.
[0033] In summary, based on the experience gained while developing and testing the first and second prototypes of my side-by-side flexible twin bicycle embodiment, I have concluded that several of the previously proposed prior art embodiments listed in table 1 suffer from a number of limitations, disadvantages or shortcomings that result in not meeting the attributes claimed by the inventors. Some of said limitations, disadvantages and shortcomings are related to:
a. Mechanical complexity that may introduce too much play between components and results in undesirable twisting and misalignment of the embodiment. b. Mechanical complexity that requires complex fabrication methods and result in relatively heavy assemblies. c. Link geometry pivot points that when the assemblage is attempted to be leaned and turned into corners would result in a rigid not a flexible structure as claimed. d. Embodiment assemblage structures that introduce repetitive bending and/or twisting stresses to each bicycle frame and the assemblage components. These stresses can eventually result in permanent deformation and/or metal fatigue and failure of said stressed frames and components. e. Some of the proposed designs employ springs intended to maintain the assemblies plus riders in an upright position while at rest and while riding on a straight path and simultaneously allowing for flexibility to lean into turns and to accommodate varying road conditions. I found that the sprung assemblies do not necessarily behave as claimed by the inventors under said turning or varied road conditions. f. Vertically unstable assemblies that, while accelerating, turning or braking, could result in potentially dangerous overturning conditions, contrary to the inherently safe design claimed by the inventors.
[0040] Some of the specific limitations, disadvantages and shortcomings of the relevant prior-art listed above are explained within the detailed description of example embodiments.
SUMMARY
[0041] The subject Side-by-Side Flexible Twin Bicycle is an innovative, effective and relatively safe embodiment that has been demonstrated to have the ability to lean into turns and ride over irregular surfaces affording each of the riders the handling, ride and feel similar to that of a single conventional bicycle while providing the stability of a four-wheel vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] FIG. 1 shows a perspective view of a first embodiment of the side-by-side flexible twin bicycle as assembled in the second test prototype.
[0043] FIG. 2A shows a rear perspective view of another embodiment of the side-by-side flexible twin bicycle further including front diagonal bars located between the front top link bar and the front bottom link bar.
[0044] FIG. 2B shows a perspective view of the steering link bar assemblage. Only the bicycle handlebars are shown for clarity.
[0045] FIG. 2C shows a perspective view of the rear link bar subassembly including the left and right vertical diagonal bars located between the rear top link bar and the rear bottom link bar.
[0046] FIG. 2D shows the right vertical diagonal bar of FIG. 3C in exploded view.
[0047] FIG. 2E shows a perspective view of typical pivoted link bar with examples two types of connectors.
[0048] FIG. 2F shows the typical pivoted link bar and connectors of FIG. 3B in exploded view.
[0049] FIG. 2G shows an example of one horizontal diagonal link bar in perspective view.
[0050] FIG. 2H shows the horizontal diagonal link bar of FIG. 3D in exploded view.
[0051] FIG. 3A shows the perspective view of a side-by-side flexible twin bicycle assemblage based on the 5/8-scale wood model and including the reference axes to describe linear and rotational movements of said assemblage.
[0052] FIG. 3B shows the front perspective view of a side-by-side flexible twin bicycle assemblage based on the 5/8-scale wood model illustrating the link bar connectors with coplanar pivot point geometry.
[0053] FIG. 3C shows the front perspective view of a side-by-side flexible twin bicycle assemblage based on the 5/8-scale wood model illustrating the link bar positions when said assemblage leans around the longitudinal axis of each bicycle when in a turn.
[0054] FIG. 3D shows the rear perspective view of a side-by-side flexible twin bicycle assemblage based on the 5/8-scale wood model illustrating the link bar positions when each bicycle of said assemblage rotates in opposite directions around the assemblage lateral or transverse axis.
[0055] FIG. 3E shows the rear perspective view of a side-by-side flexible twin bicycle assemblage based on the 5/8-scale wood illustrating the link bar positions when each bicycle of said assemblage is displaced along its normal axis as when riding at a different elevation in relation to the other bicycle.
[0056] FIG. 4A shows two bicycles connected side-by-side in parallel with single link bar connected on the front side of the head tube and vertical diagonal links with compression springs as installed in the first test prototype.
[0057] FIG. 4B shows a perspective view of the single front link bar and its components as installed in the first test prototype.
[0058] FIG. 4C shows a simplified diagram of the forces acting on a bicycle while it is leaning in a turn.
[0059] FIG. 4D shows the perspective view of the rear link bar subassembly including the left and right vertical diagonal bars with compression springs as assembled in the first test prototype.
[0060] FIG. 4E shows right vertical diagonal bar with a compression spring of FIG. 4E in exploded view.
[0061] FIG. 5A shows an alternate embodiment of the Side-by-Side Flexible Twin Bicycle with a single horizontal diagonal link bar and a single vertical diagonal bar.
[0062] FIG. 5B shows an example of a single rear vertical diagonal bar in perspective view.
[0063] FIG. 5C shows an example of a single rear vertical diagonal bar in exploded view.
[0064] FIG. 5D shows an example of a quick release mechanism on a pivoted joint connection in perspective view.
[0065] FIG. 5E shows an example of a quick release mechanism on a pivoted joint connection in exploded view.
[0066] FIG. 5F shows an example of a spring steel strip and concentric sleeve embodiment of the link bar pivoted joint connection in perspective view.
[0067] FIG. 5G shows an example of a spring steel strip and concentric sleeve embodiment of the link bar pivoted joint connection in exploded view.
[0068] FIG. 5H shows an example of a spring steel “C” wire and concentric sleeve embodiment of the link bar pivoted joint connection in perspective view.
[0069] FIG. 5I shows an example of a spring steel “C” wire and concentric sleeve embodiment of the link bar pivoted joint connection in exploded view.
[0070] FIG. 5J shows an example of a “T” joint embodiment of the link bar pivoted joint connection in perspective view.
[0071] FIG. 5K shows an example of a “T” joint embodiment of the link bar pivoted joint in exploded view.
[0072] FIG. 5L shows an example of a torsion spring joint embodiment of the link bar pivoted joint connection in perspective view.
[0073] FIG. 5M shows an example of a torsion spring joint embodiment of the link bar pivoted joint connection in exploded view.
[0074] FIG. 5N shows an example of a boxed joint embodiment of the link bar pivoted joint connection in perspective view.
[0075] FIG. 5O shows an example of the tabs and stops joint embodiment of the link bar pivoted joint connection in perspective view.
[0076] FIG. 6A shows an alternate embodiment of the side-by-side flexible twin bicycle further including an example of a combined brake assemblage.
[0077] FIG. 6B shows an example of a combined brake assemblage lever box for the front tires.
[0078] FIG. 7A shows an example of an alternate embodiment of the side-by-side flexible twin bicycle comprising two tandem bicycles.
[0079] FIG. 7B shows an example of an alternative embodiment of the side-by-side flexible twin bicycle comprising two bicycles of different sizes.
[0080] FIG. 7C shows an example of an alternate embodiment of the side-by-side flexible twin bicycle comprising two motorcycles.
[0081] FIG. 7D shows the frames of the example of an alternate embodiment of the side-by-side flexible twin bicycle comprising two motorcycles of the embodiment in FIG. 7 c omitting other components of the motorcycles for clarity.
[0082] FIG. 8A is a copy of FIG. 1A Prior Art from U.S. Pat. No. 8,146,937.
[0083] FIG. 8B is a copy of FIG. 1 Prior Art from U.S. Pat. No. 3,836,175.
DETAILED DESCRIPTION
FIGS. 1 , 2 A, 2 B, 2 C, 2 D, 2 E, 2 F, 2 G, and 2 H
[0084] Various aspects described or referenced herein may be directed to different embodiments of an inventive side-by-side flexible twin bicycle having various features as illustrated and described and/or referenced herein.
[0085] One embodiment of the side-by-side flexible twin bicycle is shown in FIG. 1 in front perspective view as assembled in the second test prototype. Four link bars connect the left side bicycle 110 a and the right side bicycle 110 b of this embodiment. Said link bars are the upper front link bar 210 a , the lower front link bar 210 b , the upper rear link bar 210 c , the lower rear link bar 210 e . The assemblage is also comprised of the steering link bar 240 , the left and right horizontal diagonal link bars 220 a and 220 b respectively, and the left and right vertical diagonal bars 230 a and 230 b respectively.
[0086] FIG. 2A shows a rear perspective view of an embodiment of two bicycles connected side-by-side in parallel similar to FIG. 1 with the exception of extra front left and right vertical diagonal bars 250 a and 250 b respectively attached to the upper front link bar 210 a and the lower front link bar 210 b.
[0087] FIG. 2B shows a perspective view of the steering mechanism composed of link bar 240 , the left steering pivot arm 242 a attached to the handlebar stem of the left side bicycle 110 a , and the right steering pivot arm 242 b attached to the handlebar stem of handlebar of the right side bicycle 110 b . Said figure shows only the respective bicycles handlebars for clarity.
[0088] FIG. 2C shows a perspective view of an example of a rear link bar subassembly 205 consisting of the left vertical diagonal bar 230 a , the right vertical diagonal bar 230 b that are pivotally attached to the upper rear link bar 210 c via the vertical diagonal bar support tabs 232 , and pivotally attached to the left and right rear bottom link bar support assemblies 231 a and 231 b respectively that are in turn attached to the rear wheel axle bolt of the left and right bicycles 110 a and 110 b respectively. Said left and right rear bottom link bar support assemblies 231 a and 231 b also support the lower rear link bar 210 d . An alternate embodiment not shown in FIG. 2C would have the bottom pivoted ends of the left vertical diagonal bar 230 a and the right vertical diagonal bar 230 b connected to the lower rear link bar 210 d in a similar fashion as the extra front left and right vertical diagonal bars 250 a and 250 b that are attached to the upper front link bar 210 a and the lower front link bar 210 b as shown in FIG. 2A . FIG. 2C also shows the rear left and right top link bar supports 233 a and 233 b that are attached near the seat tubes of the left and right bicycles 110 a and 110 b respectively.
[0089] FIG. 2D shows an exploded view of the right vertical diagonal bar 230 b . Said vertical diagonal bar subassembly is composed of the vertical diagonal bar support tabs 232 , the spherical rod end bearings 234 , the inner concentric tube 235 , the shaft collar 236 , the outer concentric tube 237 and the lower support tabs 239 that are attached to the left and right rear bottom link bar support assemblies 231 a and 321 b . The left vertical diagonal link bar 230 a and attachments is a mirror image of the right horizontal diagonal link bar 230 b.
[0090] FIG. 2E shows a perspective view of an example of a typical link bar subassembly, in this case the lower front link bar 210 b , with an example of link bar support tabs 211 on the right side attached to the down tube of bicycle 110 b , and an example of a link bar support bushing 217 on the left side attached to the down tube of bicycle 110 a . Said figure shows only a section of the down tubes to represent each bicycle for clarity. The link bar supports, tabs 211 and bushing 217 , are shown attached to the underside of the down tube of each bicycle as examples of pivoted joint attachment methods. Alternatively, both front link bars can be attached to the front of the head tube of each bicycle for example by means of bushing 217 attachments.
[0091] FIG. 2F shows an exploded view of the lower front link bar 210 b subassembly of FIG. 2E . The lower front link bar 210 b subassembly is composed of spherical rod end bearings 234 , locknuts 213 , threaded inserts 214 that are attached to each end of link bar tube 215 , and spherical rod end bearing with threaded lug 216 .
[0092] FIG. 2G shows a perspective view of the right horizontal diagonal link bar 220 b subassembly with link bar support tab 222 that is attached on the front end to the chain stay tube of bicycle 110 b and on the rear end near the middle of the lower rear link bar 210 d . The left horizontal diagonal link bar 220 a subassembly and attachments is a mirror image of the right horizontal diagonal link bar 220 b subassembly. FIG. 2G shows only a section of the lower rear link bar 210 d for clarity.
[0093] FIG. 2H shows an exploded view of the right horizontal diagonal link bar 220 b subassembly of FIG. 2G , with the link bar support tab 222 and the lower rear link bar 210 d . The horizontal diagonal link bar 220 b subassembly is composed spherical rod end bearing centering bolt 226 , spring retaining washers 223 , spherical rod end bearing centering springs 224 , spherical rod end bearing 234 , threaded inserts 214 , link bar tube 221 , and spherical rod end bearing with threaded lug 216 . FIG. 2H shows only a section of the lower rear link bar 210 d for clarity.
Operation—FIGS. 1, 2 A, 2 B, 2 C, 2 D, 2 E, 2 F, 2 G and 2 H
[0094] The manner of operation of the side-by-side flexible twin bicycle embodiment is similar to the operation of a single standard bicycle. The link bars 210 a , 210 b , 210 c and 210 d in FIG. 1 , in combination with the attachment points on the frames of bicycles 110 a and 110 b , conform a cuboid with articulating joint connectors at each of the eight pivoted vertices. Said pivoted cuboid shape arrangement allows the bicycles to lean sideways to conform into a front view parallelogram that can eventually collapse flat in a similar fashion as when a single bicycle falls on its side.
[0095] The function of the vertical diagonal bars 230 a and 230 b is to limit the maximum sideways inclination of the assemblage and prevent said flat sideways collapse. Vertical stability of the assemblage is provided by each bicycle rider combination acting, in synchrony with link bars 210 a , 210 b , 210 c and 210 d and the left and right vertical diagonal link bars 230 a and 230 b , as a counterweight to the other bicycle rider combination to reduce the likelihood of lateral falls.
[0096] The key element for the correct functioning of said assemblage, that is not evident from previous art, to allow for free rotation of said assemblage while maintaining accurate alignment of the different components and avoid imposing undesirable bending and torsional stresses on the structure, is the use of precision articulating joint connectors that, as will be explained later, have to be accurately located on the same planes.
[0097] There are alternative precision articulating joint connectors and several examples will be discussed later in the alternate pivoted joint embodiments section. For purposes of the present discussion the side-by-side flexible twin bicycle assemblage is illustrated with spherical rod end bearings 234 or 216 .
[0098] The spherical rod end bearing is a mechanical articulating joint that allows for free rotation around the main rotation axis, that is, the centerline of the attachment bolt that passes through the center of the spherical rod end bearing sphere. The spherical rod end bearing also allows for limited rotation perpendicular to said main axis to accommodate for misalignment. A variety of spherical rod end bearings are commercially available with right and left hand treads to allow for adjustment of the rod length, and with factory installed threaded lugs as an option.
[0099] The link bars 210 a , 210 b , 210 c and 210 d maintain the parallel longitudinal alignment of the two bicycles 110 a and 110 b and allow for small adjustments in length of the link bars for fine tuning of said parallel alignment. Making reference to FIG. 2E and FIG. 2F , the fine tuning of the parallel alignment is possible without the need to disconnect the link bar by using a left threaded spherical rod end bearings 234 or 216 , lock nuts 213 and threaded inserts 214 on one end of the bar, and right threaded spherical rod end bearings 234 or 216 , lock nuts 213 and threaded inserts 214 on the other end of said link bar. The length of the particular link bar is fine tuned by loosening the lock nuts 213 , rotating the link bar tube 215 and attached threaded inserts 214 to obtain the desired length and tightening the lock nuts 213 to lock the spherical rod end bearings 234 in the new position.
[0100] The link bars 210 a , 210 b , 210 c and 210 d are preferably attached to the bicycle frames in such a manner that the spherical rod end bearing main rotation axis is as near as possible to horizontal to avoid potential for binding and damage to the spherical rod end bearing when the assemblage leans sideways. The center of the spherical rod end bearing sphere is preferably located at the vertical center plane of the bicycle frames to minimize a reduction in the track when said assemblage leans to the side.
[0101] The limited rotation of the spherical rod end bearing perpendicular to the axis of the attachment bolt allows for rotation around the axis defined by the centerline of the link bar. The rotation around the centerline axis of link bars 210 a , 210 b , 210 c and 210 d , in synchrony with the rotation around the spherical rod end bearing main rotation axis, allows each bicycle to rotate or pitch around the transverse axis of the assemblage to conform to differences in bumps or hollows on each individual bicycle riding path as will be explained in more detail later under the Coplanar Pivoted Joints section.
[0102] The steering mechanism pivot arms 242 a and 2426 are attached to the handlebar stems in an angle that conforms to Ackerman steering geometry enabling said assemblage to be steered as a unit. Ackermann steering geometry is a geometric arrangement of linkages in the steering of a vehicle designed to solve the problem of wheels on the inside and outside of a turn needing to trace out circles of different radius. The steering link bar 240 length can be varied, as explained earlier in relation to link bars 210 a , 210 b , 210 c and 210 d , to fine-tune the assemblage steering alignment.
[0103] Making reference to FIG. 2C and FIG. 2D , the vertical diagonal bars 230 a and 230 b limit the maximum sideways inclination or lean of the assemblage by allowing the inner concentric tube 235 to slide into the outer concentric tube 237 until the shaft collar 236 that is securely attached to the inner concentric tube 235 makes contact with the top of the outer concentric tube 237 . The shaft collar 236 position on the inner concentric tube 235 is adjustable to set the maximum lean angle of the assemblage based on rider style and preferences. Shaft collar 236 can be a commercially available clamping style shaft collar.
[0104] The lean angle of a bicycle in a turn is a function of the bicycle speed and radius of said turn, defined by rider style and preferences, as will be explained later under the Operation—Use of Vertical Diagonal Springs, Balance of the Lateral Forces Acting on a Bicycle section.
[0105] Setting the shaft collar 236 position on the inner concentric tubes 235 of both vertical diagonal bars 230 a and 230 b to the lowest position, that is, in contact with the top of the corresponding outer concentric tubes 237 , will conform bars 230 a , 230 b and link bar 210 d into a rigid triangle that will result in a rigid assemblage similar to a quadracycle but, contrary to the typical completely rigid quadracycle, the resulting assemblage will retain the ability to rotate or pitch around the transverse axis of the assemblage rear tires to conform to differences in bumps or hollows on each individual bicycle riding path.
[0106] The limited rotation of the spherical rod end bearing perpendicular to axis of the attachment bolt also allows for rotation around the vertical axis of the spherical rod end bearing sphere which results in undesirable surging forward of the individual bicycle in relation to the other bicycle when accelerating or lagging behind of the individual bicycle in relation to the other bicycle when braking.
[0107] The surging forward or lagging behind motion of one bicycle, if not limited to small displacements, would have two undesirable effects. First, it would allow the bicycles to move into a top view parallelogram that will reduce the track or separation distance between each bicycle. Second, it would reach the limit of the misalignment allowed by the spherical rod end bearings 234 and impose bending stresses on both the spherical rod end bearings 234 , the link bars 210 a , 210 b , 210 c and 210 d , the pivoted point attachments to the bicycle frames attachment and the bicycle frames themselves that could eventually result on damage and metal fatigue failure of any of those components.
[0108] Making reference to FIG. 1 , FIG. 2A , FIG. 2G and FIG. 2H , the horizontal diagonal link bars 220 a and 220 b dampen and limit said undesirable surging forward or lagging behind of individual bicycles to small displacements by forming semi-rigid triangles with the inner chain stay tube of each bicycle and the rear bottom link bar 210 d . Rigid triangles that would prevent even small surging or lagging displacements would be formed if the horizontal diagonal link bars 220 a and 220 b were not fitted with compression springs 224 and instead the spherical rod end bearings 234 locations were fixed on said diagonal link bars. Said rigid triangles would result in undesirable repetitive peak bending forces imposed on the inner chain stay tubes of each bicycle and on the rear bottom link bar 210 d imposed during acceleration or braking that could eventually result in metal fatigue failures. This is an example of spring mounted link bars cited earlier in the Background—Development of the Side-by-Side Flexible Twin Bicycle section that were considered to overcome the twisting and bending of frames problem.
[0109] Forces from pedaling that cause the surging forward motion of each bicycle in relation to the other are limited by the strength the rider. According to Wilson (2004), “When a rider briefly exerts a force more than [ . . . ] that needed for propulsion, there results a brisk acceleration of the system mass. Wilson explains, “The mass is so large that even a “brisk” acceleration is never very great” (page 123). According to Wilson's estimates a braking deceleration in the order of 0.5 g is the maximum that “can be risked by a crouched rider on level ground before he risks going over the handlebars” and 0.8 g is the maximum theoretical braking deceleration for tandem or recumbent bicycles (page 245). Thus it is the braking forces that impose the larger bending forces on the inner chain stay tubes of each bicycle and on the rear bottom link bar 210 d.
[0110] The sprung subassembly comprised of the spherical rod end bearing centering bolt 226 , spring retainer washers 223 and compression springs 224 , allows the spherical rod end bearing 234 to slide on the spherical rod end bearing centering bolt 226 to dampen the forces resulting from surging or lagging due to differences in acceleration or braking forces between each bicycle extending the duration and reducing the peak intensity of said the forces to reduce the bending stresses on the inner chain stay tube of each bicycle and the rear bottom link bar 210 d to acceptable levels.
[0111] An alternative embodiment of a subassembly to coordinate the braking of both bicycles and reduce the difference in deceleration between bicycles that causes the lagging behind force is explained later under the detailed description of the Combined Brakes embodiment section.
Pivoted Joints Geometry Considerations—FIGS. 3A, 3 B, 3 C, 3 D and 3 E
Coplanar Pivoted Joints
[0112] FIG. 3A shows a perspective diagram based on the 5/8-scale wood model of the Side-by-Side Flexible Twin Bicycle assemblage built in October 2014. Said model consists of the left bicycle wood scale model 300 a , the right bicycle wood scale model 300 b , the front top wood link bar 310 , the front bottom wood link bar 311 , the rear top wood link bar 312 , the rear bottom wood link bar 313 , six adjustable wood collars 320 , and the adjustable rear bottom link bar left support 330 a and the adjustable rear bottom link bar right support 330 b.
[0113] The articulating joint connectors employed on the 5/8-scale wood model of the Side-by-Side Flexible Twin Bicycle assemblage are small spherical rod end bearings of ¼″ with threaded lugs that are threaded directly into the ends of the wood link bars and to the adjustable wood collars.
[0114] The link bars 310 , 311 , 312 and 313 in FIG. 3A in combination with the right bicycle wood scale model 300 a and the left bicycle wood scale model 300 b conform a cuboid with a ¼″ spherical rod end bearing at each of the eight vertices.
[0115] The 5/8-scale wood bicycle frame model is built with ½″ and ¾″ wood dowels to simulate the frame and ¼″ plywood disks to simulate the wheels and tires. The link bars are built of ¼″ wood dowels. The wood collars 220 are 2″ diameter by ¾″ thick wood discs with a round perforation in the center and a ½″ wood dowel glued tangentially to the wood disk to allow for locating the corresponding pivot point to the outside or to the inside of the model bicycle center line. The ¼″ spherical rod end bearing are screwed into the ¼″ dowels to form the link bars and the link bars are attached to the wood collars 220 by screwing the stud into the tangential ½″ wood dowel. The wood collars 220 are secured in position on the frame with a setscrew. The rear bottom link bar supports 230 a and 230 b are made of ¾″ wood dowels that slide into a hole in the center of the rear wheel “hub” and are secured in place with a setscrew. The studs of the rear bottom link bar 213 are screwed perpendicular to the side of the rear bottom link bar supports 230 a and 230 b.
[0116] The location of the pivoted joints can be fine tuned to be coplanar through several adjustments to the wood model. The length of the four link bars 310 , 311 , 312 and 313 is adjustable by threading in or threading out the corresponding ¼″ spherical rod end bearings. The position of the rear bottom link bar supports 330 a and 330 b is adjustable by displacing the wood dowel in or out of the wood model rear wheel hub. The wood collars 220 are adjustable by moving up or down and by rotating on their center axis.
[0117] FIG. 3A shows the wood collars 220 corresponding to the upper front link bar 210 with ½″ dowels displaced to the outside of each model frame, the wood collars 220 corresponding the lower front link bar 211 with ½″ dowels displaced to the inside of each model frame, and the wood collars 220 corresponding the upper rear link bar 212 with ½″ dowels displaced to the inside of each model frame.
[0118] FIG. 3A also shows the longitudinal rotation axis Xa of the left bicycle 300 a , the longitudinal rotation axis Xb of the right bicycle 300 b , the vertical axis Ya of the left bicycle 300 a , the vertical axis Yb of the left bicycle 300 b , and the transverse rotation axis Z of assemblage.
[0119] FIG. 3B shows a perspective diagram of the 5/8-scale wood model illustrating the frame centerline plane 350 on the left bicycle wood scale model 300 a , and the articulating joint connectors plane 360 on the right bicycle wood scale model 300 b . The center of the spheres of the spherical rod end bearings 310 b , 311 b , 312 b and 313 b are located on plane 360 . The wood collar 320 arrangement allows for adjustments set the pivot points at the center of the spherical rod end bearings 310 b , 311 b and 312 b corresponding to the right bicycle wood scale model 300 b frame to define the inclined plane 360 . The rear bottom link bar right support 330 b is then located in such a manner that the pivot point at the center of the spherical rod end bearing 313 b will also fall on the inclined plane 360 . There is a corresponding mirror image inclined plane (not shown) on the right bicycle wood scale model 300 b . These planes can be made to lie vertically and converge only to the rear by setting the two front link bars 310 and 311 of the same length and set the four corresponding pivot points to fall alternatively to the outside of the center plane, on the center plane or to the inside of the center plane of each bicycle.
[0120] FIG. 3C shows a front view perspective diagram of the 5/8-scale wood model with the model bicycles 300 a and 300 b simulating leaning into a turn and illustrating the relative rotations and positions assumed by the four link bars 310 , 311 , 312 and 313 and the rear bottom link bar supports 330 a and 330 b.
[0121] FIG. 3D shows a rear view perspective diagram of the 5/8-scale wood model with the model bicycles 300 a and 300 b simulating turning around the transverse axis Z of the assemblage and illustrating the relative rotations and positions assumed by the four link bars 310 , 311 , 312 and 313 , the spherical rod end bearings 310 a , 310 b , 311 b , 312 a , 312 b , 313 a and 313 b , the rear bottom link bar supports 330 a and 330 b , and the reduction in track 380 resulting from the twist of the assemblage around the transverse axis Z.
[0122] FIG. 3E shows a rear view perspective diagram of the 5/8-scale wood model with the model bicycles 300 a and 300 b simulating riding at different elevations and illustrating the relative rotations and positions assumed by the four link bars 310 , 311 , 312 and 313 and the rear bottom link bar supports 330 a and 330 b , and the resulting reduction in track 390 .
Operation—Coplanar Pivoted Joints
[0123] The 5/8 scale Side-by-Side Flexible Twin Bicycle wood model was built in October 2013 to test and verify if the hypothesis that by locating the pivoted points on inclined divergent planes like the inclined plane 360 on the left bicycle wood scale model 300 a of FIG. 3B and its corresponding mirror image inclined plane (not shown) on the right bicycle wood scale model 300 b , to form an irregular cuboid with pivoted joints at each of the eight vertices conforming a “V” shape both on front view and top view, independent of the resulting difference between link bar length, would not result in an unintentional non evident rigid assemblage or in unacceptable deviations from parallelism, but would instead allow for unforced rotation around the longitudinal axes Xa and Xb, and the transverse axis Z of said assemblage as shown in FIG. 3C , FIG. 3D and FIG. 3E . There was no point in continuing with a full-scale prototype with rigid link bars if this hypothesis was proved not to be true.
[0124] FIG. 3C , FIG. 3D and FIG. 3E were prepared by manipulating the 5/8-scale wood model of the Side-by-Side Flexible Twin Bicycle assemblage and observing and measuring the angles assumed by each component and using that information in the 3D CAD diagram.
[0125] FIG. 3C shows a front perspective diagram of the 5/8-scale wood model leaning and steering in a turn. It can be observed in the FIG. 3C that the individual frames 200 a and 200 b do not remain parallel. The frame on the inside of the assemblage, 200 a , assumes a slightly steeper inclination angle. This is related to the vertical convergence of the pivot point plane towards the bottom in a fashion analogous to the Ackerman steering geometry discussed earlier. The inclination of both frames results in a reduction of their separation that is proportional to the length of each link bar multiplied by the cosine of the inclination angle. There is also a slight horizontal convergence of the pivot point plane towards the rear. The separation at the rear of the assemblage is further reduced because the rear bottom link bar 213 is the shortest and it has to assume a steeper inclination angle. This steeper inclination angle, combined with the inclination of the rear bottom link bar supports 230 a and 230 b further reduces the separation at the rear of the assemblage. The steeper inclination angle of the inside frame 200 a , combined with the narrowing effect at the rear of the assemblage, contributes to the inside bicycle assuming a tighter turn radius complementing the effect of the Ackerman steering geometry explained earlier. The magnitude of these divergences in leaning angles and between the front and rear track are considered inconsequential.
[0126] FIG. 3D shows a rear view perspective diagram of the 5/8-scale wood model with the assemblage simulating turning around the transverse axis. In this case the left side bicycle 300 a is shown on a descending ramp while the right side bicycle 300 b is shown on an ascending ramp. While experimenting with the 5/8-scale wood model simulating different rotations around the transverse plane Z it was found that, contrary to the longitudinal axes Xa and Xb that lie in a fixed position defined by the contact patch of the front and rear tire of each bicycle, the location of the transverse axis Z is dependent on the particular elevations or depressions encountered by each bicycle along its travel path. Thus, link bars 310 , 311 , 312 and 313 assume different inclination angles depending on the location of the transverse axis Z and, as explained earlier, the transverse axis Z coincides with the rear wheels hub centerline when the vertical diagonal bars are set to render the assemblage vertically rigid. The distance between the two model frames is reduced proportional to the cosine of the particular link bar angles; the net effect is a reduction in track 380 .
[0127] FIG. 3E shows a rear view perspective diagram of the 5/8-scale wood model with the model bicycle 300 a riding at a higher elevation than model bicycle 300 b . Link bars 310 , 311 , 312 and 313 assume slightly different inclination angles related to their different lengths and the distance between the two model frames is reduced proportional to the cosine of the link bar angle, the net effect is a reduction in track 390 .
Detailed Description Alternate Embodiment
FIGS. 4 A, 4 B, 4 C, 4 D and 4 E
[0128] Another embodiment of the side-by-side flexible twin bicycle is shown in FIG. 4A , side perspective view, as assembled in the first test prototype. The difference between the first and second prototypes is that the first prototype employed a single front link bar 410 and vertical diagonal bars 430 a and 430 b with compression springs. All other components are the same as for the second prototype discussed above.
[0129] FIG. 4B shows a perspective view of the single front link bar 410 , with link bar support collar composed of split shaft collars 412 , support tabs 413 , and threaded inserts 214 . The single front link bar 410 subassembly is composed of spherical rod end bearings with threaded lug 216 , locknuts 213 , and threaded inserts 214 attached to each end of link bar tube 215 .
[0130] FIG. 4C shows the front view of a single bicycle leaning into a turn, the center of gravity of the bicycle and rider C g , and a simplified model of the forces acting on the bicycle, the centrifugal force F c , the gravitational force F g , the centripetal (friction) force F f , and the normal force F n .
[0131] FIG. 4D shows a perspective view of the rear link bars assemblage similar to FIG. 2C with the exception that the diagonal vertical links 430 a and 430 b are fitted with compression springs. The rest of the description is the same as that of FIG. 2C .
[0132] FIG. 4E shows an exploded view of the right vertical diagonal link bar 430 b . Said link bar subassembly is composed of the vertical diagonal bar support tabs 232 , upper spherical rod end bearing 234 , the inner concentric tube 235 , a threaded sleeve 422 attached to the inner concentric tube 235 , spring adjustment nut 424 , spring support washer 426 , compression spring 428 , spring retainer washer 429 attached to the outer concentric tube 237 , lower spherical rod end bearing 234 and lower support tabs 239 that are attached to the right rear bottom link bar support assemblage 231 b . The left vertical diagonal link bar 430 a and attachments is a mirror image of the right horizontal diagonal link bar 430 b.
[0000] Operation—First Prototype with Single Front Link Bar
Problems with Bicycle Frame Flexing Under Lateral Loads
[0133] Testing of the first prototype started in early February 2014. The first problem encountered was progressive misalignment and excessive scrubbing of the front tires. It was observed, even when attempting to run on a straight line, that the assemblage consisting of the right side handlebar, fork and front tire, would progressively twist on its vertical plane reducing the front track of the assemblage and progressively increasing scrubbing and rolling resistance. The twisting effect became so extreme that the rider of the offending bicycle had to do a small jump, enough to lift the front tire from the ground to relieve the load, to allow the handlebar, fork and front tire assemblage to spring back to alignment. But the twisting would immediately resume after the front tire fell back on the ground.
[0134] This problem was initially attributed to misalignment of the assemblage but could not be resolved with link bar length fine-tuning adjustments. Then a test was done that consisted of manually applying a bending torque, using the front tire and fork assemblage as a lever arm, and it was observed that the head tube would twist around the spherical rod end bearings 234 axis of the single front link bar assemblage 410 and transmit that torsion to the bicycle frames. The twisting motion was most marked at the bottom brackets and pedal assemblies that were observed to move sideways in the order of one to two inches depending on the force applied. The steering link bar 240 did not contribute to the assemblage rigidity since the twisting motion would cause the handlebars, fork and tire subassembly to rotate on the head tube axis.
[0135] The twisting of the head tube joint is explained by Wilson (2012, p. 381) as “ . . . the front forks act as a long lever arm to “twist” that joint. [ . . . ] therefore, in the welded or brazed case [ . . . ] stresses and deflections will be high. The origin of this problem is related to flexing of the front tires under lateral loads.” In relation to tires Wilson (2012, p.297) explains: “Tires are considered to be somewhat flexible vertically for obstruction swallowing, but rigid otherwise. For many purposes this approximation is good enough. But in actuality, the possibility of lateral flex of a tire means that when tires are supporting a side load, they do not travel exactly in the direction they are pointed.”
[0136] The “not traveling exactly in the direction they are pointed” is the beginning of the twisting of the bicycle frames. The lateral loads on tires can originate from the pedaling forces, from unintended rider movements to the side or from uneven road surface among other causes. Wilson (2012, p. 355) also explains the phenomenon of flexing of the frame and the difficulty in bracing to increase its rigidity: “The tubes in a bicycle's frame usually experience, during riding, a combination of bending, shear, torsion, and tension or compression. Appropriate sizes for the frame's components have been arrived at by experience, not by analysis or prediction. And even with advanced engineering software it would be difficult and expensive to analyze all the combined stresses that act on a bicycle frame and therefore improve its design more than marginally.”
[0137] The magnitude of this problem was such that the frame of the right side bicycle of the first prototype was permanently deformed and bent to the extent that the front and rear tire appear to be forming a narrow “X” when seen from the front.
[0138] The single front link bar 410 on the head tube was replaced with two link bars 210 a installed above on the top tube and 210 b installed below on the bottom tube. These two link bars provided enough rigidity to the assembly to reduce the twisting of the frames to be essentially imperceptible.
[0139] As discussed earlier, prior art that would probably suffer from flexing of frames under lateral loads resulting in misalignment and the bending stresses to the frames include U.S. Pat. No. 8,146,937 B2 to Chin, et al., 2012, Apr. 3, shown in FIG. 8B Prior Art; U.S. Pat. No. 7,669,868 to Underhaugh, 2010, Mar. 2; U.S. Pat. No. 3,836,175 to Pomerance et al., 1974, Sep. 17, shown in FIG. 8B Prior Art; U.S. Pat. No. 3,350,115 to Ferrary, 1967, Oct. 10; and U.S. Pat. No. 469,722 to Riess, 1892, Mar. 1; since these depend on only one link bar on the front that does not provide the vertical rigidity of a quadrilateral rendering the assemblage prone to the same twisting and misalignment problem experienced with the first prototype.
[0140] Making reference to FIG. 8A Prior Art, U.S. Pat. No. 8,146,937 B2 to Chin, et al., 2012, Apr. 3; this assemblage consists of a bicycle with a third “auxiliary” wheel joined by a single “articulating mechanism” link element 5 to form a tricycle. In relation to the transverse axis running through the center of said articulating mechanism, it is probable that, upon road testing of this assemblage, the combinations of twisting and bending forces around said transverse axis, due to vertical and lateral loads from road-induced deformation of tires, will be of such magnitude that the third auxiliary tire will twist and wander on both the horizontal and vertical planes and eventually the mechanical integrity of the whole embodiment would be compromised.
[0141] Another shortcoming of said assemblage is related to longitudinal stability. In a regular bicycle, the horizontal distance from the center of gravity to the front tire contact patch is a critical parameter to prevent an “end-over-end” (throwing the riders and bicycle over the handlebar and front wheel) when descending steep slopes or during emergency braking. Wilson (2012. p. 245) explains: “Skilled riders increase their deceleration capability when descending steep slopes by crouching as low as possible and as far behind the bicycle's saddle as possible.” This is to move the center of gravity as low and to the rear as possible to reduce the inertial overturning torque and increase the opposing front tire reaction torque to reduce the possibility of an “end-over-end”.
[0142] The center of gravity of the assemblage in U.S. Pat. No. 8,146,937 B2 to Chin, et al., 2012, Apr. 3; is located somewhere between the primary bicycle 100 and the auxiliary bicycle 310 , while the effective front tire contact patch is moved back approximately to the middle of a line connecting the primary bicycle 100 front tire contact patch with the auxiliary bicycle 310 tire contact patch. The reduced horizontal distance from the effective front tire contact patch to the center of gravity reduces the effective front tire reaction torque increasing the likelihood of an “end-over-end” during cornering or braking as compared to a regular bicycle.
[0143] An attempt to improve the longitudinal stability of said embodiment with an additional auxiliary wheel 47 is shown in FIG. 8A Prior Art. It is claimed that with this modification “the twin-frame bicycle of the invention is highly stable without any possibility of tumbling, even in a high-speed riding and/or a sudden braking”. Based on the experience with the single link bar in the first prototype discussed earlier, and Wilson's (2012) explanations on emergency braking decelerations and on frame rigidity (or lack of it) during lateral loads to said auxiliary wheel 47 , it is very likely that the relatively long and slender adjustable bar 48 will bend and collapse immediately after experiencing a lateral load on said auxiliary wheel 47 with potential for an “end-over-end” or “tumbling” during cornering or braking that could lead to a serious accident.
[0144] Another attempt to improve the lateral stability shown in FIG. 22 of said patent to maintain alignment between the primary bicycle 110 and the auxiliary bicycle 310 consist of a second “articulating mechanism” link element 5 between the rear wheel of the primary bicycle and the wheel of the auxiliary bicycle. The primary bicycle 110 and the auxiliary bicycle 310 are secured at two points, however, it is unlikely that this modification will significantly reduce the twisting of both bicycles around the axis defined by the two support points of each bicycle when the tires are exposed to lateral forces. The resulting bending would look like in a front view to an upright or an inverted V depending on the net direction of the forces from the road to the tires. This type of continued flexing would eventually result in metal fatigue and failure.
[0145] The alternate embodiment shown in FIG. 23 of said patent consists of two bicycles held together by a single “articulating mechanism” link element 5 between the head tube of the two bicycles. It is unlikely that this arrangement will prevent both horizontal and vertical rotation of the bicycles around the single pivot point connected to the head tubes resulting in bending and twisting of said link element 5 and the embodiment going out of alignment due to lateral forces on the front and rear tires.
Operation—Use of Vertical Diagonal Springs
Balance of the Lateral Forces Acting on a Bicycle
[0146] The following discussion on forces acting on a bicycle and balance in a turning maneuver is relevant for the explanation of the use of springs in some prior art embodiments and for the explanation of the problem encountered early in February 2014 while testing the first prototype of the side-by-side flexible twin bicycle.
[0147] Making reference to FIG. 4C , balance in a bicycle is maintained when the resulting torques from the centrifugal force F c , and the gravitational force F g acting through the tire contact patch with the road are equal. The gravitational force F g is the product of the rider and bicycle mass multiplied by the acceleration of gravity. The centrifugal force F c is the product of the rider and bicycle mass multiplied by square of the speed, divided by the radius of the turn. Thus, the leaning angle of a bicycle in a turn is directly proportional to the square of the speed and inversely proportional to the radius of the turn.
[0148] A simple explanation of how a rider balances a bicycle is when the rider feels the bicycle falling to one side; the rider “steers into direction of the fall”. That steering motion causes a curved trajectory of such radius that generates the appropriate centrifugal force to avoid the fall. Fajans (2000) explains in a detailed sequence of steps how a rider executes a turn. In summary, the rider first applies a small amount of steer in the opposite direction of the turn and that steering motion generates a centrifugal force that causes the rider and bicycle to lean (“fall”) into the desired direction of the turn. The rider then “steers into direction of the fall” to maintain balance and lean angle while following the desired curved path until the turn is completed. Then the rider applies an almost imperceptible additional amount of steer into the direction of the turn to generate the additional centrifugal force that pushes the bicycle out of the lean to continue traveling in a straight line.
[0149] Both balancing and turning a bicycle are unconscious motor skills that the rider learns when learning to ride the bicycle and that require the brain to coordinate inputs from multiple sensory systems. The vestibular system located in the inner ear provides the leading contribution about balance and movement. The vestibular system is capable of detecting both the centrifugal force F c , gravitational force F g . When riding in a turn the brain of an experimented bicycle rider interprets that the rider and bicycle are not falling even thought it is receiving visual information that both rider and bicycle are leaning to one side.
Operation—Use of Vertical Diagonal Springs
[0150] Difficulties with Springs Intended to Keep the Assemblage Upright
[0151] Making reference to the first test prototype as shown in FIG. 4A fitted with compression springs on the vertical diagonal bars 430 a and 430 b , once substitution of the single link bar 410 with the two link bars 210 a and 210 b as shown in FIG. 1 resolved the problem related to twisting of the frames explained earlier, the next problem, encountered was related to entering, executing and exiting from turns.
[0152] It was found that the problem was related to the intended function of the compression springs in the first prototype, the same intention as stated in prior art U.S. Pat. No. 3,836,175 to Pomerance, 1974, Sep. 17, (components 18 and 20 in FIG. 8a Prior Art), to “maintain the bicycles in a vertical position when standing or moving in a straight direction and allow the bicycles to lean when turning as would be the case when a single rider makes a turn”. The experience while testing the first prototype was that the use of springs in this manner made it essentially impossible to complete a steady turn following the intended curved path.
[0153] The force that an extension or a compression spring exerts is proportional to its deflection or change in length. The force divided by the deflection is the spring rate and is assumed to be essentially constant within the recommended spring deflection range. The spring will not exert a force unless it undergoes a deflection. Thus, to keep the bicycles and riders in a vertical position when standing requires relatively strong springs and pre-loading to ensure that said springs are under compression and exerting enough force to prevent the bicycles and riders from leaning and falling to one side or the other.
[0154] When the compression springs 428 on the first prototype vertical diagonal bars 430 a and 430 b were set with enough preload to keep the bicycles and riders in a vertical position when standing and said first prototype was inclined into a turn the springs were compressed in proportion to the lean angle and this resulted in an increase of the force exerted by the spring proportional to the lean angle that pushed the bicycles in the opposite direction of the lean. The difficulty in following the desired arc of the turn in this situation arises from the fact that, contrary to the case of the centrifugal force F c , and the gravitational force F g , the vestibular system of the rider does not detect this additional upright spring force. The brain interprets the resulting effect in the same manner as if the riders and the side-by-side flexible twin bicycle assemblage are falling to the outside of the turn. The unconscious motor reaction of the rider is to “steer into the fall” and away from the desired arc of the turn.
[0155] The force exerted by the springs is in the opposite direction of the gravitational force F g and increases as the lean angle is increased as needed for turning at higher speed. The extreme situation as recently demonstrated by researchers at Cornell University, (MacMichael, 2014), is that when the force exerted by said springs is such that it cancels the gravitational force F g , the bicycle, “in zero gravity” becomes unsteerable. In our case while testing the first prototype, the spring force was of a lower magnitude, however, it made it very difficult to execute a steady turn.
[0156] We found that this effect can be consciously overcome while riding, by using relatively weak springs and little or no preload, by applying a quick steering jerk in the opposite direction of the desired turn. But this defeated the original objective of maintaining the bicycles and riders in a vertical position when standing. The method to consciously overcome this effect is similar to when initiating a turn to counter steer to help compress the springs, followed by both riders leaning out-of-balance into the turn to counteract the additional spring force that resulted. However, maintaining a constant inclination and the corresponding steady turn radius proved to be difficult. The increase in spring force as the lean angle increased kept pushing the bicycles to the outside of the turn and required a series of counter steering jerks in the opposite direction which in turn resulted in a wobbly and unpredictable widening of the turn arc. Both the repetitive steering jerks in the opposite direction and the leaning of the body to counter the spring force feels “unnatural” to bicycle riding. This technique is considered to be potentially dangerous and is not recommended since it requires a very aggressive sequence of counter steering jerks that not all riders may be able to execute and the resulting widening of the turn away from the intended turn arc may put the riders and bicycles in a dangerous situation, for instance into the front of oncoming motor vehicle traffic on the opposite lane.
[0157] Prior art including U.S. Pat. No. 8,146,937 B2 to Chin, et al., 2012, Apr. 3; U.S. Pat. No. 3,836,175 to Pomerance, 1974, Sep. 17, and other US patents listed in the prior art table that employ springs or semi-resilient assemblies to keep assemblage and riders upright is likely to exhibit this undesirable and potentially dangerous behavior.
[0158] It was found that it is preferable not to use springs to keep assemblage and riders upright and instead allow the embodiment when at rest to lean to one side or the other, as a single bicycle would do and provide mechanical means to limit the maximum lean angle, which is as discussed earlier, a function of travel speed and radius of turns, based on rider preference.
Operation—Limit on how Much Leaning is Desirable
[0159] There is a limit on how much leaning is desirable in a particular riding situation. As explained earlier, the leaning angle of a bicycle in a turn is directly proportional to the square of the speed. The average speed of a cyclist depends on a number of factors including weather, terrain, style and weight of the bicycle and cyclist physical condition.
[0160] In an urban environment, a person on a sit-up style roadster at a leisure pace might do less than 6 mph. Most cyclists can achieve 10-12 mph very quickly with limited training. More experienced cyclists doing short to medium distances of 20 to 30 miles can average around 16 mph. A competent rider, with regular training, can do distances of 50 to 60 miles at an average speed of 20 to 24 mph.
[0161] The leaning angle of a bicycle in a turn is inversely proportional to the radius of the turn. The following tests, on what is now termed the second prototype as shown in FIG. 1 , were conducted after the compression springs 428 were removed. The maximum leaning of the resulting assemblage reached a mechanical limit, see FIGS. 4D and 4E , when the lower part of the threaded sleeve 422 welded to the inner concentric tube 235 , with the compression spring 428 removed, reached the top of lower concentric tube 237 . This was about 15 degrees inclination from vertical. We found that this inclination was adequate for speeds between 8 to 12 mph and turn radius between 20 and 30 feet typical of an urban setting.
[0162] Riding through the turn without the compression springs 428 felt similar to riding an individual bicycle up to the point where the mechanical limit was reached, from then on it felt like riding a bicycle with training wheels. A sudden stop in the rate of inclination was felt when the mechanical limit was reached. In subsequent tests the springs were installed loose to dampen the sudden stop by setting the spring adjustment nut 424 about 1 inch above the top of the spring to allow for unhindered inclination and dampened the jolt just when the mechanical limit was to be reached. The mechanical limit is reached by reducing the speed when going through the turn to a sufficiently low speed. To prevent reaching the mechanical stop requires a slightly higher speed.
[0163] Varying the distance between the spring 428 and the spring adjustment nut 424 allows the riders to set the maximum angle of inclination as a function of their riding style and preferred speeds for a particular road. Setting the spring adjustment nut 424 for maximum compression of the vertical diagonal springs 428 will result in an essentially rigid assemblage that will keep the bicycles and riders vertical even when stopped. Riders wishing to ride at low speeds similar to a quadracycle would prefer this setting. Setting the spring adjustment nut 424 for maximum separation from the top of the vertical diagonal springs 428 will result in an embodiment that will leant as much as the particular design of the vertical diagonal links will allow allowing the riders to travel at high speeds and take turns at high inclination angles. Removing the vertical diagonal links will allow the assemblage to fall to one side or the other and travel at maximum speeds and inclinations typical to those of a competent rider on single bicycle.
[0164] The above-cited research and development work has resulted in the demonstration of an innovative, effective and safe side-by-side flexible twin bicycle embodiment that can be simultaneously or independently operated by one or more driver riders; provides the vertical stability of a four-wheel vehicle; allows for the simultaneous banking, rolling or leaning around the longitudinal axis to enter, execute and exit from turns in a manner similar to riding a typical single bicycle; allows for the independent rotation or pitching around the transverse or lateral axis to conform to bumps or hollows in the riding path, and allows for the independent vertical surge to conform to differences in elevation in the riding path, while maintaining relative parallel position that, to our knowledge, none of the cited previous art can provide.
DETAILED DESCRIPTION OF ALTERNATE EMBODIMENTS
FIGS. 5 A, 5 B, and 5 C
[0165] Various aspects described or referenced herein may be directed to different embodiments of an inventive side-by-side flexible twin bicycle having various features as illustrated and described and/or referenced herein.
[0166] FIG. 5A shows a rear perspective view of an alternate embodiment of the side-by-side flexible twin bicycle with a single horizontal diagonal link bar 520 and a single vertical diagonal bar 530 .
[0167] FIG. 5B shows an example of a single rear vertical diagonal bar 530 in perspective view.
[0168] FIG. 5C shows an example of a single rear vertical diagonal link 530 in exploded view. Said vertical diagonal bar subassembly is composed of the top support tabs 532 , spherical rod end bearings 234 , threaded inserts 214 , the inner concentric tube 533 , quick release pin 535 , dowel pin 536 , outer concentric tube 537 , longitudinal slot 539 and the bottom support tabs 538 that are attached to the left rear bottom link bar support 231 a.
[0169] An exploded view of the single horizontal diagonal link bar 520 and attachments is not included since it is similar to the left horizontal diagonal link bar 220 a shown in FIG. 2A with the exception that the corresponding link tube 221 is longer and the attachment point of the spherical rod end joint 234 is displaced from the middle toward the right end of the rear bottom link bar 210 d.
[0170] Operation—Single Vertical Diagonal Link Bar
[0171] The vertical diagonal bar 530 limits the maximum sideways inclination in either direction by allowing the inner concentric tube 533 shown in FIG. 5C to slide into the outer concentric tube 537 until the dowel pin 536 which secured to the inner concentric tube 533 and its ends protrude into the groove 539 of the outer concentric tube 537 reaches either end of the groove 539 . The length of the groove 539 determines the maximum movement of the inner concentric tube 533 into the outer concentric tube 537 and hence the maximum inclination of the bicycles 110 a and 110 b . The inner concentric tube 533 is provided with a number of perforations 531 that coincide along the length of the groove 539 on the outer concentric tube 537 and are used to accommodate quick release pins 535 to reduce the maximum inclination of the bicycles 110 a and 110 b to several intermediate values chosen based on rider preference. The assemblage is rendered rigid when the quick release pins 535 are located at the extreme perforations, which coincide with the ends of the groove 539 .
[0172] The operation of the single horizontal diagonal link bar 520 is similar to the operation of the diagonal link bar 220 b discussed earlier.
Detailed Description of Alternate Pivoted Joint Embodiments—FIGS. 5D and 5E.
[0173] Various aspects described or referenced herein may be directed to different embodiments of an inventive pivoted joint having various features as illustrated and described and/or referenced herein.
Detailed Description Quick Disconnect Joint Embodiment—FIGS. 5D and 5E
[0174] FIG. 5D shows the quick disconnect link bar joint 512 embodiment in perspective view.
[0175] FIG. 5E shows the quick disconnect link bar joint 512 embodiment in exploded view. Said quick disconnect joint link bar is composed of the butted bushing 217 that is attached to the bicycle 110 b frame, the smooth bore insert 514 that is attached to the butted bushing 217 , and the quick release lock pin 515 .
Operation—Quick Disconnect Joint Embodiment
[0176] The quick disconnect joint allows fast assembly and disassembly of the side-by-side flexible twin bicycle into two bicycles for individual use. Making reference to FIG. 2C , the quick disconnect joint embodiment consists of modifying the rear link bars subassembly 205 by attaching the bottom connection of the vertical diagonal bars 230 a and 230 b to the lower rear link bar 210 d instead of to the left and right rear bottom link bar support assemblies 231 a and 231 b , so that said modified rear link bars subassembly is supported at four points at the spherical rod end bearings 234 of the upper rear link bar 210 c and of the lower rear link bar 210 d . The smooth bore inserts 514 are similar to the threaded inserts 214 with the exception that the internal thread is drilled out smooth to accommodate the quick release lock pin 515 . The front top link bar 210 a , the front bottom link bar 210 b and the steering link bar 240 are fitted in a similar manner with quick release connectors. The quick release lock pins 515 are commercially available, one example is the Kwik-Lok® Pins manufactured by Jergens Inc.
Detailed Description of Alternate Pivoted Joint Embodiments—FIGS. 5F, 5 G, 5 H, 5 I, 5 J, 5 K, 5 L, 5 M and 5 O
Note:
[0177] FIGS. 5F through 5O represents a series of alternative pivot embodiments that, making reference to FIGS. 1 , 2 A, 4 A, 5 A, 6 A, 7 A, 7 B, 7 C and 7 D, are designed to substitute the function of the vertical diagonal bars 230 a , 230 b , 250 a and 250 b , and the horizontal diagonal link bars 220 a and 220 b . The function of the vertical diagonal bars 230 a , 230 b , 250 a and 250 b is to limit the maximum sideways inclination to prevent the side-by-side twin bicycle embodiment from leaning excessively to either side and essentially collapse flat. The function of the horizontal diagonal link bars 220 a and 220 b is limit to small displacements the surging forward or lagging behind motion of each bicycle in relation to the other during acceleration or braking. The connection between link bar 210 b and a section of the down tube of the right side bicycle 110 d is used as an example to illustrate the alternate pivoted joint embodiments. These alternate pivoted joint embodiments can be adapted for use on any link bar pivot location.
Detailed Description of the Spring Steel Strip and Concentric Sleeve Pivot Joint Embodiment—FIG. 5F and FIG. 5G
[0178] FIG. 5F shows the spring steel strip and concentric sleeve link bar pivoted joint embodiment 540 in perspective view.
[0179] FIG. 5G shows the spring steel strip and concentric sleeve link bar embodiment 540 in exploded view. Said spring steel strip and concentric sleeve link bar embodiment is composed of the support tabs 542 that are attached to the bicycle frame, the spring steel strips 541 that are attached on one end to the support tabs 542 and at the other end to the sliding collar 543 , the fixed collars 544 attached to the link bar tube 215 , the hole 545 on the link bar tube 215 , the quick release pin 535 , the slot shaped transverse opening on the sliding collar 546 , the spherical rod end bearing 234 , and the threaded insert 214 .
Operation of the Spring Steel Strip and Concentric Sleeve Pivot Joint Embodiment in FIGS. 5F and 5G
[0180] The spring steel strips 541 provide bending resistance to minimize the rotation of the link bar 210 b in the horizontal plane and thereby limit to small displacements the surging forward or lagging behind motion of each bicycle in relation to the other during acceleration or braking. The combination of the spring steel strips 541 with horizontal attachment points at both ends, a bolt on the top end and the studs 547 attached to the sliding collar 543 on the other end, allows for rotation of the link bar 210 b on the vertical plane while the sliding collar 543 slides on the link bar 210 b and thereby allows for leaning of the side by side twin bicycle assemblage.
[0181] The fixed collars 544 attached to the link bar tube 215 serve as mechanical stops for the sliding collar 543 to limit the maximum sideways inclination in either direction by allowing the sliding collar 543 to slide on the link bar tube 215 until the sliding collar 543 reaches either of the fixed collars 544 . The quick release pins 535 renders the assemblage rigid as it relates to leaning when said quick release pins are inserted through the slot 546 on the sliding collar 543 and the hole 545 on the link bar 210 b to allow riding the side-by-side flexible twin bicycle in a vertically rigid mode.
[0182] The slot 546 on the sliding collar 543 allows for rotation of the link bar 210 b around its centerline axis thereby allowing the side-by-side flexible twin bicycle assemblage to rotate around its transverse axis to accommodate for bumps or hollows on the path of each individual bicycle.
Detailed Description of the Spring Steel “C” Wire and Concentric Sleeve Pivot Joint Embodiment—FIGS. 5H and 5I
[0183] FIG. 5H shows the spring steel “C” wire and concentric sleeve link bar pivot embodiment 550 in perspective view.
[0184] FIG. 5I shows the spring steel “C” wire and concentric sleeve link bar pivot joint embodiment 550 in exploded view. Said spring steel “C” wire and concentric sleeve link bar pivot joint embodiment is similar in construction to the spring steel strip and concentric sleeve link bar pivot embodiment 540 except for the use of the round spring rod 551 bent in a “C” shape instead of the spring steel strips 541 , shaft collars 552 are provided to keep the spring steel “C” wire 551 in place, the sliding collar bushing 554 is attached under the sliding collar 553 , and the bushing spacer 555 provides support between the tabs 542 . All other components are as described earlier.
Operation of the Spring Steel “C” Wire Pivot Joint Embodiment in FIGS. 5H and 5I
[0185] The spring steel “C” wire 551 provides bending resistance to minimize the rotation of the link bar 210 b in the horizontal plane and thereby limit to small displacements the surging forward or lagging behind motion of each bicycle in relation to the other during acceleration or braking. The combination of the spring steel “C” wire 551 with horizontal attachment points at both ends, a bolt on the top end and the bushing 554 attached to the bottom sliding collar 553 on the other end, allows for rotation of the link bar 210 b on the vertical plane and thereby allows for leaning of the side by side twin bicycle assemblage.
[0186] The fixed collars 544 attached to the link bar tube 215 serve as mechanical stops for the sliding collar 553 to limit the maximum sideways inclination in either direction by allowing the sliding collar 553 to slide on the link bar tube 215 until the sliding collar 553 reaches either of the fixed collars 544 . The quick release pins 535 renders the assemblage rigid as it relates to leaning when said quick release pins are inserted through the slot 546 on the sliding collar 553 and the hole 545 on the link bar 210 b to allow riding the side-by-side flexible twin bicycle assemblage in a vertically rigid mode.
[0187] The slot 546 on the sliding collar 553 allows for rotation of the link bar 210 b around its centerline axis thereby allowing the side-by-side twin bicycle assemblage to rotate around its transverse axis to accommodate for bumps or hollows on the path of each individual bicycle.
[0000] Detailed Description of the “T” Pivot Joint Embodiment in— FIGS. 5J and 5K
[0188] FIG. 5J shows the “T” joint 560 embodiment for the link bars pivots in perspective view.
[0189] FIG. 5K shows the “T” joint 560 pivot embodiment for the link bars in exploded view. Said “T” joint pivot embodiment is composed of the butted bushing 217 attached to the bicycle frame, the threaded insert 214 attached to said butted bushing, the support bolt 564 , the “T” joint bolt 561 , the hollow bolt 562 , the lock nut 213 , the external retaining ring 563 , and the “L” support tab 565 fitted with slot 566 . The “T” joint bolt 561 is inserted into the hollow bolt 562 and secured in place with the external retaining ring 563 . The hollow bolt 562 is attached to the threaded insert 214 of the link bar 210 b and locked in place with lock nut 213 .
Operation of the “T” Pivot Joint Embodiment in FIGS. 5J and 5K
[0190] The slot 566 on “L” support tab 565 provides a mechanical stop to minimize the rotation of the link bar 210 b in the horizontal plane and thereby limit to small displacements the surging forward or lagging behind motion of each bicycle in relation to the other during acceleration or braking while allowing for rotation of the link bar 210 b on the vertical plane and thereby allowing for leaning of the side by side twin bicycle embodiment. The ends of the slot 566 serve as mechanical stops to limit the maximum sideways inclination in either direction. The “T” bolt 561 inserted through the hollow bolt 562 and secured with the external retaining ring 563 allows for rotation of the link bar 210 b around its centerline axis thereby allowing the side-by-side twin bicycle assembly to rotate around its transverse axis to accommodate for bumps or hollows on the path of each individual bicycle.
Detailed Description of the Torsion Spring Pivot Joint Embodiment—FIGS. 5L and 5M
[0191] FIG. 5L shows the torsion spring pivot joint embodiment 570 for the link bars in perspective view.
[0192] FIG. 5M shows the torsion spring pivot joint embodiment 570 for the link bars in exploded view. Said torsion spring pivot joint embodiment is composed of support tabs 575 , attached to the bicycle frame, the spring retaining bushing 576 attached to a perforation on the bicycle frame, bolt 574 , torsion spring support tabs 575 , spring retaining washers 573 , bushing 572 , torsion spring 571 and nut 577 on the bicycle frame side, the spring retaining shaft collar 578 , hollow bolt 562 , locknut 213 , threaded insert 214 , nut 574 and link bar tube 215 . The bicycle frame end of the torsion spring 571 is secured in place by inserting its end into the spring retaining bushing. The link bar end of the torsion spring 571 is inserted into the hollow bolt 562 and secured in place with the spring retaining shaft collar 578 and nut 574 . The hollow bolt 562 is attached to the threaded insert 214 of the link bar 210 b and locked in place with lock nut 213 .
Operation of the Torsion Spring Pivot Joint Embodiment in FIGS. 5L and 5M
[0193] The torsion spring 571 provides bending resistance to minimize the rotation of the link bar 210 b in the horizontal plane and thereby limit to small displacements the surging forward or lagging behind motion of each bicycle in relation to the other during acceleration or braking while allowing for rotation of the link bar 210 b on the vertical plane and thereby allowing for leaning of the side by side twin bicycle embodiment. The resistance that the compression spring offers to rotation of the link bar 210 b on the vertical plane is inversely proportional to the number of loops in the spring and much lower than the resistance to the rotation in the horizontal plane.
[0194] The internal diameter of the torsion spring is reduced as the spring is twisted in the direction of the winding until it reaches bushing 572 which then serves as the mechanical stop to limit the maximum sideways inclination in either direction.
[0195] The torsion spring 571 leg inserted through the hollow bolt 562 and retained by nut 574 allows for rotation of the link bar 210 b around its centerline axis thereby allowing the side-by-side twin bicycle assemblage to rotate around its transverse axis to accommodate for bumps or hollows on the path of each individual bicycle.
Detailed Description of the Box Pivot Joint Embodiment—FIG. 5N
[0196] FIG. 5N shows the box pivot joint embodiment 580 for the link bars in perspective view. Said box pivot joint embodiment is composed of box joint support 582 attached to the bicycle frame, the link bar protective sleeve 583 , the “C” clip 581 and the quick release pin 535 . Other link bar components are similar to those described under FIG. 2F option with spherical rod end bearing 234 .
Operation of the Box Pivot Joint Embodiment in FIG. 5N
[0197] The vertical rectangular shape of the box joint support 582 provides a mechanical stop to minimize the rotation of the link bar 210 b in the horizontal plane and thereby limit to small displacements the surging forward or lagging behind motion of each bicycle in relation to the other during acceleration or braking while allowing for rotation of the link bar 210 b on the vertical plane and thereby allowing for leaning of the side by side twin bicycle assemblage.
[0198] The rounded ends of the box joint support 582 serve as mechanical stops to limit the maximum sideways inclination in either direction. The “C” clip 581 renders the assemblage rigid as it relates to leaning when said “C” clips are inserted into slots 584 in the box joint support 582 and secured in place with the quick release pin 535 to allow riding the side-by-side twin bicycle assemblage in a vertically rigid mode.
[0199] The spherical rod end bearing 234 , hidden from view by the box joint support 582 , allows for rotation of the link bar 210 b around its centerline axis thereby allowing the side-by-side flexible twin bicycle assemblage to rotate around its transverse axis to accommodate for bumps or hollows on the path of each individual bicycle.
[0200] The wrench slot 585 allows for a wrench to reach the link bar 210 b lock nut 213 that is not visible in the figure. The protective sleeve 583 , made of plastic, rubber or any other suitable material, prevents metal-to-metal contact between the box joint support 582 and the link bar 210 b.
Detailed Description the Tabs and Stops Pivot Joint Embodiment—FIG. 5O
[0201] FIG. 5O shows the tabs and stops pivot joint embodiment 590 for the link bars in perspective view. Said tabs and stops pivot joint embodiment is composed of tabs joint supports 591 attached to the bicycle 110 b frame, fixed bushings 592 , movable bushings 593 and quick release pins 535 . Other link bar components are similar to those described previously.
Operation of the Tabs and Stops Pivot Joint Embodiment in FIG. 5O
[0202] The vertical rectangular shape of the tabs pivot joint support 591 provides a mechanical stop to minimize the rotation of the link bar 210 b in the horizontal plane and thereby limit to small displacements the surging forward or lagging behind motion of each bicycle in relation to the other during acceleration or braking while allowing for rotation of the link bar 210 b on the vertical plane and thereby allowing for leaning of the side by side twin bicycle assemblage.
[0203] The fixed bushings 593 , attached at the extreme ends between tabs 591 , serve as mechanical stops to limit the maximum sideways inclination in either direction. The movable bushings 592 can be attached with the quick release pins 535 in a number of intermediate quick release pin orifice positions 594 to serve as mechanical stops to reduce the range of the sideways inclination. When said movable bushings 592 are installed at the quick release pin orifice positions 594 nearest position to link bar 210 b they render the assemblage rigid as it relates to sideways leaning motion.
[0204] The spherical rod end bearing 234 , hidden from view by the tabs joint supports 591 , allows for rotation of the link bar 210 b around its centerline axis thereby allowing the side-by-side flexible twin bicycle assemblage to rotate around its transverse axis to accommodate for bumps or hollows on the path of each individual bicycle.
Detailed Description of the Combined Brakes Embodiment—FIGS. 6A and 6B
[0205] FIG. 6A shows a front perspective view of an alternate embodiment of the side-by-side flexible twin bicycle with combined brakes. Said combined brakes embodiment is composed of combined brakes assembly box 600 , shown as an example attached to front bottom link bar 210 b , brake levers 610 a and 610 b for the front wheels brakes, brake levers 611 a and 611 b for the rear wheels brakes, and the associated brake cables. The combined brakes assemblage box 600 is composed of front wheels brakes assemblage box 605 and rear wheels brakes assemblage box 606 .
[0206] FIG. 6B shows a perspective view of the front brake assembly box 605 . Said front brakes assemblage box is composed of the brake box base 612 , front brakes lever 613 , brake cables retaining screws 614 , brake cable 615 connected to the front wheels brake lever 610 a on the left side bicycle 110 a , brake cable 616 connected to the front wheel brake caliper 620 a of the left bicycle 110 a , brake cable 617 connected to the front wheels brake lever 610 b on the right side bicycle 110 b , and brake cable 618 connected to the front wheel brake caliper 620 b of the right bicycle 110 b . Brake cables 616 and 617 are connected to one side of the brake box crank 613 with a brake cable retaining screw 614 and brake cables 615 and 618 are connected to the other side of the brake box crank 613 with a second brake cable retaining screw 614 .
[0207] The rear brakes assemblage box 606 , not shown in detail, is similar to the front brake assemblage box except that it is actuated from brake levers 611 a and 611 b , and in a similar fashion actuates on the brake calipers of the rear wheels.
Operation of the Combined Brakes Embodiment
[0208] The combined brakes embodiment allows for either or both riders to have, individually or simultaneously, control of the assemblage brakes and to apply brakes to the assemblage front and rear wheels of the side-by-side twin bicycles in a similar manner as when riding a single bicycle.
[0209] Applying pressure the front wheels brake lever 610 a on the left side bicycle 110 a will pull brake cable 615 connected to the brake box lever 613 which will rotate and pull both brake cables 616 and 618 which in turn will activate the front wheel brake caliper 620 a of the left bicycle 110 a and the front wheel brake caliper 620 b of the left bicycle 110 b . Applying pressure the front wheels brake lever 610 b on the right side bicycle 110 b will result in the same action.
[0210] The rear brakes assembly box 606 , not shown in the figures, is similar to the front brakes assembly box 605 and operates the rear wheels brake calipers in an analogous manner.
Detailed Description Side-by-Side Flexible Twin (Tandem) Bicycle—FIG. 7A
[0211] Various aspects described or referenced herein may be directed to different embodiments of an inventive side-by-side flexible twin cycle having various features as illustrated and described and/or referenced herein.
[0212] FIG. 7A shows a front perspective view of an embodiment of the side-by-side flexible twin bicycle related to an assemblage 700 consisting of two side-by-side tandem bicycles able to accommodate four riders. Six link bars connect the left side tandem bicycle 701 a and the right side tandem bicycle 701 b of this embodiment. Said link bars are the front top link bar 210 a , the front bottom link bar 210 b , the rear top link bar 210 c , the rear bottom link bar 210 d , the middle link bar 710 e , and the steering link bar 240 . The horizontal diagonal link bars 220 a and 220 b provide longitudinal stability. Four concentric bars, the rear vertical diagonal bars 230 a and 230 b and the front vertical diagonal bars 250 a and 250 b provide vertical stability.
Operation—Side-by-Side Flexible Twin Tandem Bicycle
[0213] The manner of operation of the side-by-side flexible twin tandem bicycle is similar to that of the side-by-side flexible twin bicycle discussed earlier.
[0000] Detailed Description of the Side-by-Side Flexible Twin Bicycle with Bicycles of Different Sizes— FIG. 7 b
[0214] Various aspects described or referenced herein may be directed to different embodiments of an inventive side-by-side flexible twin cycle having various features as illustrated and described and/or referenced herein.
[0215] An embodiment of the side-by-side flexible twin bicycle shown in FIG. 7B in front perspective view relates to an assemblage 705 consisting of two side-by-side bicycles of different sizes to be able to accommodate an adult rider and a child rider. Four link bars connect the large left side bicycle 706 a and the small right side bicycle 706 b , horizontal diagonal link bar(s) provide longitudinal stability, vertical diagonal link bar(s) provide vertical stability, and the steering link bar 711 coordinates the steering of the assemblage as a unit in a similar fashion to previously explained embodiments.
[0000] Operation—Side-by-Side Flexible Twin Bicycle with Bicycles of Different Sizes
[0216] The manner of operation of the side-by-side flexible twin bicycle with bicycles of different sizes is similar to that of the side-by-side flexible twin bicycle discussed earlier.
Detailed Description Side-by-Side Flexible Twin Motorcycle Embodiment—FIGS. 7C and 7D
[0217] Various aspects described or referenced herein may be directed to different embodiments of an inventive side-by-side flexible twin motorcycle having various features as illustrated and described and/or referenced herein.
[0218] An embodiment of the side-by-side flexible twin motorcycle 720 , shown in FIG. 7C in front perspective view, relates to an assemblage consisting of two side-by-side motorcycles. FIG. 7C shows five link bars connecting the left side motorcycle 721 a and the right side motorcycle 721 b of this embodiment. Said link bars are the upper front link bar 722 a , the lower front link bar 722 b , the upper rear link bar 722 c , the lower rear link bar 722 d and the steering link bar 740 . Horizontal diagonal link bar(s) and vertical diagonal bar(s), not shown in FIG. 7C , provide longitudinal stability and vertical stability in a similar fashion to previously explained embodiments. The steering link bar 740 coordinates the steering of the assemblage as a unit in a similar fashion to previously explained embodiments.
[0219] FIG. 7D shows the frames of the motorcycles 721 a and 721 b , and the four link bars 722 a , 722 b , 722 c and 722 d . It is to be noted that contrary to bicycles, where the lower rear link bar has to be located further to the rear to avoid interference with the pedal mechanism, the lower rear link bar 722 d of the twin motorcycle embodiment can be located ahead of the rear tires in a position that permits all pivot joint locations to fall on the vertical centerline plane of the motorcycles if desired.
[0220] The twin motorcycle assemblage can employ any of the alternative pivoted joint embodiments described above including horizontal diagonal bar(s) projecting backwards from the lower rear link bar 722 d to the chain stay tubes and vertical diagonal bar(s) between the front link bars 722 a and 722 b , and between the rear link bars 722 c and 722 d.
Operation—Side-by-Side Flexible Twin Motorcycle
[0221] The manner of operation of the side-by-side flexible twin motorcycle is similar to that of the side-by-side flexible twin bicycle embodiments discussed earlier. Coordination of the brake systems, both hydraulic and cable, can be analogous to the combined brake embodiment discussed above, except that in the case of an hydraulic brake system it would consist of combination of hydraulic lines. Coordination for acceleration and shifting can also be combined employing electro-mechanical components.
[0000]
TABLE 1
Prior Art
Patent
Number
Issue Date
Patentee
Shortcomings
8,146,937
3 Apr. 2012
Chin et al.
Longitudinal frame flexing,
use of sprin to keep assem-
blage and riders upright,
limited vertical stability.
7,669,868
2 Mar. 2010
Underhaug
Single link element, limited
lateral stability.
6,068,278
30 May 2000
Kock et al.
Rotation on transverse axis
only.
6,022,036
8 Feb. 2000
Chartrand
Rigid, inclination adjustable
with hand crank.
5,511,809
30 Apr. 1996
Sagi
Semi rigid resilient (“sprung”)
assemblage.
4,290,620
22 Sep. 1981
Chika
Semi rigid resilient (“sprung”)
assemblage.
4,288,089
8 Sep. 1981
Thiessen
Rotation in the transverse axis
only.
3,865,401
11 Feb. 1975
Kingsly
Leaning on the longitudinal
axis only.
3,836,175
17 Sep. 1974
Pomerance
Unsteerable, unintentional
et al.
rigid assemblage, prone to
longitudinal flexin and
twisting of each bicycle
frame, use springs
to keep assemblage and riders
upright.
3,350,115
31 Oct. 1967
Ferrary
Flat horizontal springs to keep
assemblage and riders upright.
676,535
18 Jun. 1901
Elliott
Rigid assemblage with limited
longitudinal surging.
636,155
31 Oct. 1899
Mackay
Flat curved springs to keep
assemblage and riders upright.
616,407
20 Dec. 1898
Cottrell
Rotation in the transverse axis
et al.
only.
469,722
1 Mar. 1892
Riess
Unintentional rigid assem-
blage.
indicates data missing or illegible when filed
[0000]
TABLE 2
LIST OF REFERENCE NUMERALS
Side-By-Side Flexible Twin Bicycle Component and Part Numbers
Figure
Part No.
Description
Side-by-Side Flexible Twin Bicycle - Second
Prototype
1
110a
Left bicycle
110b
Right bicycle
2A
210a
Front top link bar
210b
Front bottom link bar
210c
Rear top link bar
210d
Rear bottom link bar
220a
Left horizontal diagonal link bar
220b
Right horizontal diagonal link bar
230a
Left vertical diagonal bar
230b
Right vertical diagonal bar
240
Steering link bar
2B
250a
Front left vertical diagonal bar
250b
Front right vertical diagonal bar
242a
Left steering link arm
242b
Right steering link arm
2C
205
Rear link bars subassembly
231a
Left rear bottom link bar support
231b
Right rear bottom link bar support
232
Vertical diagonal bar support tabs
233a
Rear left top link bar support
233b
Rear right top link bar support
2D
234
Spherical rod end bearing
235
Inner concentric tube
236
Shaft collar
237
Outer concentric tube
239
Support tabs
2E
211
Link bar support tabs
2F
213
Lock nut
214
Threaded insert
215
Link bar tube
216
Spherical rod end bearing with threaded lug
217
Butted pipe bushing
221
Horizontal link bar tube
222
Horizontal diagonal link bar support tab
223
Spring retaining washer
224
Spherical rod end bearing centering spring
226
Spherical rod end bearing centering bolt
Side-by-Side Flexible Twin Bicycle - Wood Scale
Model
3A
300a
Left bicycle wood scale model
300b
Right bicycle wood scale model
310
Front top wood link bar
311
Front bottom wood link bar
312
Rear top wood link bar
313
Rear bottom wood link bar
320
Adjustable wood collars
330a
Adjustable rear bottom link bar left support
330b
Adjustable rear bottom link bar right support
3B/C
310a
Front top link bar left spherical rod end bearing
310b
Front top link bar right spherical rod end bearing
311a
Front bottom link bar left spherical rod end bearing
311b
Front bottom link bar right spherical rod end bearing
312a
Rear top link bar left spherical rod end bearing
312b
Rear top link bar right spherical rod end bearing
313a
Rear bottom link bar left spherical rod end bearing
313b
Rear bottom link bar right spherical rod end bearing
350
Left bicycle frame center plane
360
Right bicycle pivot joint inclined plane
3D
380
Track reduction due to rotation around transverse axis
3E
390
Track reduction due to vertical surge
Side-by-Side Flexible Twin Bicycle - First Prototype
4A
410
Single front link bar assembly
430a
Left vertical diagonal bar with spring
430b
Right vertical diagonal bar with spring
4B
412
Large shaft collar
413
Support tab - single front link bar
4D
422
Threaded sleeve
424
Spring adjustment nut
426
Spring support washer
428
Compression spring
429
Spring retainer washer
Examples of Alternate Pivoted Link Embodiments
5A
520
Single horizontal diagonal link bar
5B
530
Single vertical diagonal bar
5C
532
Top support tabs
533
Inner concentric tube
535
Quick-release pin
536
Dowel pin
537
Outer concentric tube
538
Bottom support tabs
539
Longitudinal slot
5D
512
Quick disconnect pivoted link bar joint
514
Smooth bore insert
5E
515
Quick release lock pin
5F
540
Spring strip steel strip pivoted link bar joint
5G
541
Spring steel strip
542
Support tabs - spring steel joint
543
Sliding collar
544
Fixed collar - mechanical stop
545
Quick release pin orifice
546
Quick release pin slot
547
Sliding collar studs
5H
550
Spring steel “C” rod pivoted link bar joint
5I
551
Spring steel “C” rod
553
Sliding collar
554
Sliding collar bushing
555
Bushing spacer
5J
560
“T” joint pivoted link bar joint
5K
561
“T” joint bolt
562
Hollow bolt
563
External retaining ring
564
Bolt
565
“L” support tab
566
Slot on the “L” support tab
5L
570
Torsion spring link bar joint
5M
571
Torsion spring
572
Spring mechanical stop bushing
573
Spring retaining washer
574
Nut
575
Torsion spring support tabs
576
Spring retaining bushing
577
Nut
578
Spring retaining shaft collar
5N
580
Box pivot joint
581
“C” clip
582
Box joint support
583
Protective sleeve
584
Slots
585
Wrench slot
5O
590
“Tab” link bar joint
591
Joint support tabs
592
Fixed bushing
593
Movable bushing
594
Intermediate quick release pin orifice
Side-by-Side Flexible Twin Bicycle - Combined
Brakes
6A
600
Combined brake assemblage box
605
Front wheels brake assemblage box
606
Rear wheels brake assemblage box
610a
Front wheels brake lever - left bicycle
610b
Front wheels brake lever - right bicycle
611a
Rear wheels brake lever - left bicycle
611b
Rear wheels brake lever - right bicycle
612
Front brakes box assemblage base
613
Front brakes lever
614
Brake cable retaining screw
615
Brake cable from left bicycle front wheels brake
lever 610a
616
Brake cable to left bicycle front wheel brake caliper
617
Brake cable from right bicycle front wheels brake
lever 610b
618
Brake cable to right bicycle front wheel brake caliper
620a
Front wheel brake caliper - left bicycle
620b
Front wheel brake caliper - right bicycle
Side-by-Side Flexible Twin Bicycle - Other
Embodiments
7a
700
Side-by-Side Flexible Twin Tandem Bicycle
701a
Left tandem bicycle
701b
Right tandem bicycle
710e
Tandem bicycle middle link bar
705
Side-by-side flexible twin unequal size bicycles
706a
Large left side bicycle
706b
Small right side bicycle
711
Unequal size bicycles steering link bar
720
Side-by-side flexible twin motorcycle
721a
Left side motorcycle
721b
Right side motorcycle
722a
Front top link bar
722b
Front bottom link bar
722c
Rear top link bar
722d
Rear bottom link bar
740
Steering link bar
REFERENCES
[0000]
All about bicycles. (n.d.). What Is So Great About a 4 Wheel Bicycle? Retrieved Feb. 15, 2014, from: http://www.all-about-bicycles.com/4-wheel-bicycle.html
Fajans, J. (2000). Steering in bicycles and motorcycles . American Journal of Physics, 68(7), 654-659.
MacMichael, S. (2014, Mar. 28). Video: You can't steer a bike in zero gravity, say researchers. Retrieved May 15, 2014, from http://road.cc/content/news/115377-video-you-cant-steer-bike-zero-gravity-say-researchers
Pressman, D. (2012). Patent it yourself. Nolo.
Schwab, A. L. (2012). Bicycling safety and the lateral stability of the bicycle. Proceedings, International Cycling Safety Conference , Helmond, The Netherlands.
Wilson, D. G. (2012). Bicycle science. (3 rd Ed.) Cambridge, Mass. The MIT Press. | Various embodiments of a side-by-side flexible twin bicycle are disclosed. In at least one embodiment, the side-by-side flexible twin bicycle includes two bicycles joined together side-by-side by means of a plurality of interconnecting pivoted link bars. One or more driver riders may simultaneously or independently operate said side-by-side flexible twin bicycle. In at least one embodiment, the side-by-side flexible twin bicycle may be configured employing different size bicycles, in-line multi-rider tandem bicycles, recumbent bicycles, mountain bicycles, and motorcycles of various types. These embodiments provide the vertical stability of a four-wheel vehicle while retaining the ability to lean into turns and ride over irregular surfaces affording for each of the riders the handling, ride and feel similar to that of a single conventional bicycle. | 1 |
This is a continuation in part of my earlier application Ser. No. 10/867,296, filed Jun. 14, 2004, now abandoned.
FIELD OF THE INVENTION
The proposed invention is a means of generating ions in the air at atmospheric pressure. In particular the species of ion generated is the superoxide ion, O 2 − . The superoxide ion being the desired species because of its ability to accommodate the benefit of cleaning the air. Simultaneously, the superoxide ion, O 2 − does not have the harmful effects of ozone, O 3 , to humans. The proposed invention is capable of producing only negative ions and zero positive ions. The means of doing this is novel and unobvious. Also the proposed invention can produce a predetermined ratio of positive and negative ions.
BACKGROUND OF THE INVENTION AND PRIOR ART
There are various and sundry means of generating oxygen species ions. These involve arc discharge through the air. An early discourse on such discharge phenomenon is found in the text, “The Discharge of Electricity Through Gases,” Charles Scribner's Sons, New York: 1899. S. S. Thompson, “Lord Kelvin.” Another text is “Fundamental Processes of Electrical Discharge in Gases,” Leob, Leonard, B., John Wiley and Sons, 1939.
A more recent text, “Spark Discharge” by Bazelyan et al; explains the phenomenon of streamers quite nicely. The problem in discharging electricity through air is that air is stubborn. It takes energy to start the arc which results in a type of avalanche breakdown. This avalanche breakdown produces as arc in which electrons have a lot of energy. This is undesirable because these electrons can cleave molecular oxygen, O 2 , in half to produce atomic oxygen, O. This atomic oxygen can then react with molecular oxygen to produce ozone. Ozone is unwanted because of its proposed harmful effects to humans.
The proposed invention liberates electrons into the air at a low energy. Avalanche dielectric breakdown of the air is absent. The superoxide ion is formed in abundance as opposed to ozone.
Techniques of producing ions in air usually involve a sharp needlelike electrode. At the tip of such a needle the electric field gets very high and dielectric breakdown occurs. These needles can be coated with platinum and gently pulsed to limit ozone production. As a result, superoxide ion generation is also limited. Further, the small surface area of the needle head limits ion production.
Needlelike electrodes in ionization devices are ever present. For pending art see US Patent App. No, 20040025695 to Zhang at al. Therein find discussion of a plurality of wires and ground plates at high voltage to produce dielectric breakdown of the air and thus generate ions. Also is found a discussion of the point ionizer. Both of these techniques involve high voltage exposed to the raw air to produce ions. These devices however also produce ozone. The high voltage arcing through the raw air produces ozone because of the phenomenon of avalanche.
Pulsed corona discharge microwave plasma, and dielectric barrier discharge devices are all reviewed in detail in “Prospects for non-Thermal atmospheric plasmas for pollution abatement”, McAdams, J. Phys. D.: Applied Physics, 34 (2001) 2810-2821.
The pulsed corona discharge and the microwave discharge device involve passing the raw air through the corona and or plasma. This will produce ozone. This is why these devices clean the air, ozone being a powerful oxidant. However, if there are no contaminants in the air the ozone does not get used and itself is a contaminant.
The dielectric barrier discharge device DBD shown in FIG. 1 , referring to FIG. 1 , find a first electrode, 101 , a dielectric barrier, 103 , a second electrode, 105 , a region between the insulating dielectric barrier and the second electrode where air can pass, 107 , and a power supply, 109 .
In the dielectric barrier or silent discharge regime, one of the two electrodes has an insulating coating on it and an alternating current (ac) voltage is applied between the electrodes. The microdischarges occur between the insulating surface and the opposing electrode. These microdischarges have a duration of ˜1-10 ns and are self-quenching. They appear as spikes on the current waveform. For a given applied voltage, the capacitances of the insulating layer and the gap between the layer and the opposing electrode together with the applied frequency determine the power dissipation. Such dielectric barrier discharges have formed the basis of commercial ozone generators, with the ozone being used for water treatment for example.
The proposed invention is primarily not a dielectric barrier discharge device. In one of its permutations it has a plasma in an enclosed volume and the barrier is a specific material to execute specific phenomenon. In yet another embodiment the enclosure has its outer surface held at a specific potential to achieve specific results.
The short discharge pulses in region, 107 , have a lot of energy and split molecular oxygen in half to the end of producing ozone.
The proposed invention has a specific bias circuit on its outer electrode which when applied to a DBD device can reduce the ozone output of the device and increase its negative ion output. Thus in one of its embodiments it represents an improvement to all DBD devices.
Ion tubes which generate ions and or ozone have been manufactured and used for many years. The bentax tube was reviewed in my earlier U.S. application Ser. No. 10/867,296. Other ion/ozone tubes are disclosed in U.S. Pat. No. 1,793,799 to Hartman (1931), U.S. Pat. No. 1,064,064 to Franklin (1913), U.S. Pat. No. 3,905,920 to Botcharoff, U.S. U.S. Pat. No. 361,923 to Brian (1887). These devices lack the novelties of the proposed invention in that the enclosure of the tube is not specified to be an N-type semiconductor. Also the critical bias potential of the secondary electrode which is present in the proposed invention is absent in these earlier tubes.
Other means of generating negative ions include irradiating a conductor with an ultraviolet lamp to liberate electrons via the photoelectric effect. This method is employed in U.S. Pat. No. 3,128,378 to Allen et. al., U.S. Pat. No. 3,335,272 to Dickinson et. al., and U.S. Pat. No. 3,403,252 to Nagy. The proposed invention does not employ the photoelectric effect not the use of ultraviolet light. The ultraviolet light can produce ozone, O 3 , as well as atomic oxygen, O, both of which are undesirable.
BRIEF DESCRIPTIONS OF DRAWINGS
FIG. 1 : Schematic of dielectric barrier discharge device
FIG. 2 : Schematic of plasma enclosure barrier and electrode position
FIG. 3 : Driving circuit schematic
OBJECTS AND ADVANTAGES
Accordingly several objects and advantages of the proposed invention are:
(a) The proposed invention comprises a plasma bound by a barrier wherein electrons are transported through the barrier by virtue of the thermoelectric power of the barrier. The barrier is an N-Type semiconductor instead of a P-Type semiconductor.
The charge carrier of the barrier in the proposed invention is the electron. It is possible to get a higher current of electrons through such a barrier than sodium ions through the P-Type barrier of the prior art. A higher current of electrons translates into a production of more superoxide ions.
(b) The primary mechanism of ion production is electron transport through the glass. The electron appears at the surface with a low energy. It collides with O 2 molecules and they capture it to become superoxide, O 2 − . The energy input into the device goes onto heating the plasma to create the temperature gradient that drives electrons through the glass. The energy is not used to generate dielectric barrier discharge, which can generate ozone. Thus the proposed invention generates about ten times less ozone per unit energy input into the device that is for equal voltages and thickness of barrier. At the same time it produces about ten times more superoxide ions. (c) The primary mechanism of ion production is the transport of electrons through the barrier. Thus a higher transport of electrons can be achieved by floating the inner electrode at a negatively biased DC offset. This establishes a net electric field across the barrier that does not time average out to zero. There is a net electric field producing a net force on electrons. This additional force increases the electron diffusion through the barrier which gives rise to more ions. (d) In the proposed invention it is electron transport through the barrier and onto the surface of the tube that produces ions. The temperature gradient across the barrier pushes the electrons through the barrier. Thus increasing the temperature gradient can increase the ion production. Driving the plasma at the plasma frequency maximizes the temperature of the plasma. This is a critical resonant condition that results in an improvement of the ion output. The critical resonant frequency is a function of the density of the gas inside the tube and the partial ionization of the plasma. (e) The inner electrode of the plasma in the proposed invention can be floated at a negative bias D.C. offset below ground. This serves to provide means for the device to produce mostly negative ions. The negative D.C. offset provides an electric field that drives more electrons through the glass. More electron transmission gives rise to more ion production. (f) A novel unobvious improvement of my earlier application is that a critical offset voltage has been discovered for the secondary electrode which makes the device produce positive ions, thus only negative ions are produced. (g) The critical offset voltage can then be made to vary with time at resonant ion production frequencies.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 2 , the proposed invention comprises a first region containing a gas, 131 , a first electrode permeable by said gas, 123 , a plasma, 125 , formed by exciting said first electrode with an AC voltage, a barrier, 127 , which separates said first region, 131 , from a second region, 133 , and a second electrode, 129 , and said second region being the open air of the room where the device is placed, and said barrier having an inner surface, 135 , and an outer surface, 137 .
Said barrier is a dielectric material whose dielectric breakdown limit is such that the voltage applied to said first electrode does not cause dielectric breakdown through said barrier.
In one embodiment the barrier is composed of a glass or ceramic composite material such as fiberglass, or G-10. The composite materials have extrinsic defects that create channels by which thermal electrons can leak through the barrier.
In another embodiment of the invention the barrier is composed of a borosilicate or soda lime glass that is coated with a thin layer of classical semiconductor.
In another embodiment the barrier is any of the known glass or ceramic materials that are N-Type semiconductors wherein the charge carrier is the electron. In another embodiment the barrier has a thin coating of a ceramic material like Yttrium doped zirconium oxide. The zirconium oxide layer serves to damp out the kinetic energy of electrons as they move through the barrier onto its surface.
A first group of electronically conducting glasses consist of oxide glasses with relatively large concentrations of transition metal oxides, such as vanadium phosphate glasses.
A second group of electron glasses consists of sulphides, selenides, and tellurides. These are known as the chalcogenide glasses. These glasses are semiconductors but their electronic conductivity is not critically dependent on trace impurities as it is in the classical semiconductors. However, with the transition metal oxide glasses there is generally a dependence on the degree of reduction or oxidation during melting; the conductivity is generally at a maximum for a certain ratio of oxidized to reduced valence state of the transition metal ion. (Linsley, G. S., Owen., A. E. and Hayatee, F. M. (1970). J. Non-Crystalline Solids, 4, 208.
Electronically conducting glasses have a definite thermoelectric effect. This has been observed by Mackenzie. [Mackenzie, J. D. (1964) “Modern Aspects of The Vitreous State”, Vol. 3, p. 126. Butterworth. London.] The thermoelectric power of the barrier turns out to be important as will become obvious in the section on operations of the invention. The temperature gradient across the barrier is the dominant force that drives electrons through the barrier. This electron current is proportional to the product of the thermoelectric power of the material and the temperature gradient.
The first electrode, 123 , is placed in close proximity to the inner surface, 135 , of said barrier. It may be composed of a mesh material. It may also be deposited directly onto said surface but it must be done in a pattern, irregular or ordered, such that there are regions wherein the conductor is absent. One such example of a deposition of conductor would be a cross-hatched pattern. These arrangements allow for the plasma, 125 , to be formed along the inner surface, 135 .
The second electrode, 129 , is in the like of the first electrode and its permutations. That is it has holes in it, it is metallic mesh, or it is deposited directly onto the outer surface, 137 , of said barrier. If it is deposited directly it must have open regions as described of the first electrode.
This is so electrons coming to the surface can have some space to move before they hit the second electrode. This allows time for them to be picked up by oxygen molecules in said second region thereby generating the superoxide ion, O 2 − .
The second electrode, 129 , is held at a critical bias potential of at least −230 Volts. This negative voltage on the second electrode quenches the production of positive ions. It is unusual that this voltage is only −230 Volts. The second electrode is desired to be set at ground because it is exposed to the air. Sine the −230 Volts is not a “high voltage” it can be applied to the second electrode safely. Namely, if it is applied with a power supply that cannot put out more than 1 mA it is still safe to be touched by human hands without danger. The second electrode's voltage can also be made sinusoidal and negatively biased. This enhances the production of ions.
Referring to FIG. 3 a circuit is shown to drive the ion generator. The first electrode is shown as, 207 , and the second electrode is shown as, 209 . The electrodes 207 and 209 constitute a capacitor, 215 . The capacitor has a DC capacitance, C o . The circuit is excited by the sinusoidal source, 201 . The voltage is applied to a transformer, 217 , which has a primary, 203 , and a secondary, 205 . The secondary has DC inductance, L o . The second electrode, 209 , is held at its offset voltage by means of a power supply or battery, 213 . The secondary, 205 has its one lead connected to ground, 211 , and the other lead connected to the first electrode, 207 . The power supply, 213 , applies its voltage to the second electrode, 209 , with respect to ground, 211 . This circuit supplies AC high voltage to the first electrode by way of the transformer, 217 , whose secondary coil, 205 , has a DC inductance, L o . The invention operates optimally when the frequency of the circuit is in the range,
f
*
=
(
.9
-
1.3
)
1
2
π
L
o
C
o
The bias potential supplied by the power supply, 213 , can be made variable. That is it can be made adjustable so it can be varied at will between ground and a nominal negative voltage of at least −230 Volts. This allows one to create a predetermined mixture of positive and negative ions. When the invention is constructed with the barrier made of N-type semiconductor the positive ions are not harmful nitrogen ions or nitrogen-oxygen compound ions. They are rather protonated water, which is a welcome actor in the ion field.
A further optimum condition has been established. For a given AC voltage on the primary electrode the electron temperature of the plasma, 125 , can be measured with the laser. From the temperature the fraction of ionization of the plasma can be determined. The plasma is usually only partially ionized unless the gas in the first region, 131 , is at a low pressure. The equation that relates the temperature of electrons to the fraction of ionization is the Saha equation:
N
i
N
n
≈
2.4
×
10
21
T
3
/
2
N
i
ⅇ
-
U
ⅈ
/
KT
where:
Ni=ion density in particles per m 3 Nn=neutral particle density in particles per m 3 T=electron temperature as measured by laser scattering instrumentation U:=(ionization potential for the gas in said first region) K=Boltzmann's Constant
Typically the plasma is excited at 60 Hz and the electron temperature, T, is measured with a laser scattering instrument. Once the quantities N i and N n , are determined, the resonant frequency has been determined to be
f
r
=
9
N
i
(
N
i
N
n
)
The factor, 9√{square root over (N i )} is simply the plasma frequency when the neutral particles are absent. The units are in Hz if the densities are in particles per m 3 .
Let's do an example of a typical situation involving the invention. If the air in region one is nitrogen the ionization potential, Ui, is 14.5 e V. If the pressure in region one is 1 atm the total particle density N T is 3×10 25 particles per m 3 . For small fractional ionization N t is approximately equal to N n and measuring T will give us N i directly. If we use a 60 Hz signal with voltage rms amplitude of 5 KV, T is in the order of a few thousand degrees and the fractional ionization
N i N n
is on the order of 10 −6 .
This gives an ion density of:
N i ≡10 −6 N n ≡10 −6 N T
N i =10 −6 (3×10 25 part/m 3 )
N i =10 19 part/m 3
With N n =3×10 25 /m 3 the expression for f r gives
f r =[9]√{square root over (30×10 18 )}10 −6
f r =500 KHz
If the frequency applied to the first electrode is produced by means of the circuit in FIG. 3 , L o and C o , can be chosen such that f r =f*. This provides yet another critical condition on the invention parameters that gives optimum performance. Since f r is a number, Lo, and Co can be chosen exactly.
OPERATION OF THE INVENTION
Referring to FIG. 2 , a voltage is applied to said first electrode, 123 , to form a plasma, 125 . The plasma temperature is greater than the temperature in region two, 133 . This establishes a temperature gradient across said barrier. Said barrier is an N-Type semiconductor wherein the majority charge carrier is the electron. Said barrier has a thermoelectric power, P. Thus the temperature gradient pushes electrons from the plasma through said barrier. The electrons appear on the surface of said barrier and interact with the molecular oxygen in said second region, 133 . The free electrons plus molecular oxygen produce the superoxide ion, O 2 − . The negative bias on the second electrode, 129 , repels the electrons so they do not disappear into the ground before they become O 2 − .
In the embodiment wherein said barrier is simply stated to be a dielectric barrier without N-type semiconductive properties, the mechanism is different. The oscillating internal fields in the plasma induce such fields on the surface of said second electrode. If said second electrode is at the critical negative potential, these induced fields eject electrons from said second electrode, generating ions. | A plasma is generated inside a barrier enclosure made specifically of N-Type semiconductive material, said plasma thus generating a thermal gradient across said barrier which drives electrons through said barrier via the thermoelectric power of said N-Type semiconductor, said electrons thus being liberated on the opposing side of said barrier where they interact with oxygen in the air to form the superoxide ion, O 2 − , and a second electrode on said opposing being at a critical minimum negative bias potential to quench collateral production of positive ions and ensuring production only of negative, O 2 − , ions. | 7 |
BACKGROUND OF THE INVENTION
[0001] I. Field of the Invention
[0002] The present development relates generally to stent or graft devices for implantation in an anatomical structure and, more particularly, to intravascular catheter deliverable branched stent or graft devices and methods of fabrication. Embodiments include unique branched stent or graft devices for the treatment of abdominal aortic aneurysms (AAA) involving the aorta-iliac bifurcation by reinforcing, excluding, bridging, or lining the diseased vessel, and to methods of fabrication of such as stent or graft devices involving a unique braiding technique using a single plurality of filaments to form two hinged legs and the common body or trunk portion of the device.
[0003] II. Related Art
[0004] An aortic aneurysm is a weak area in the wall of the aorta, the main blood vessel that carries blood from the heart to the rest of the body. The aorta extends upwards from the heart in the chest and then arches downwards, traveling through the chest (the thoracic aorta) and into the abdomen (the abdominal aorta). The normal diameter of the abdominal aorta is about one inch (2.5 cm).
[0005] Aortic aneurysms are frequently caused by the breakdown of the muscular layer and the elastic fibers within the wall of the aorta. The breakdown usually occurs over time, frequently in patients over 40 years of age, and can be caused by prolonged high blood pressure, effects from smoking or a genetic predisposition. As the vessel tissues deteriorate, the vessel wall strength decreases, and the high blood pressure causes the aortic wall to stretch beyond its normal size, forming an aneurysm. The weak aneurysm bulges like a balloon over time and can burst if the wall becomes too thin and weak to hold the blood pressure.
[0006] Most commonly, aortic aneurysms occur in the portion of the vessel below the renal artery origins. The aneurysm may extend into the aorta-iliac bifurcation and into the iliac arteries supplying the hips, pelvis and legs.
[0007] Once an aneurysm reaches 5 cm (about 2 in.) in diameter, it is usually considered necessary to treat to prevent rupture. Below 5 cm, the risk of the aneurysm rupturing is lower than the risk of conventional surgery in patients with normal surgical risks. The goal of therapy for aneurysms is to prevent them from rupturing. Once an AAA has ruptured, the chances of survival are low, with 80-90 percent of all ruptured aneurysms resulting in death. These deaths can be avoided if the aneurysm is detected and treated before it ruptures and ideally treated at an early stage (smaller aneurysm) with a lower risk procedure.
[0008] AAA can be diagnosed from their symptoms when they occur, but this is often too late. They are usually found on routine physical examination, use of ultrasound, chest and abdominal X-rays. On examination, a doctor may feel a pulsating mass in the abdomen. If the doctor suspects an aneurysm, he/she will probably request that an ultrasound scan be carried out. Other scans, such as computerized tomography (CT) and magnetic resonance imaging (MRI) may also be performed. These scanning techniques are very useful for determining the exact position of the aneurysm.
[0009] The surgical procedure for treating AAA involves replacing the affected portion of the aorta with a synthetic graft, usually comprising a tube made out of an elastic material with properties very similar to that of a normal, healthy aorta. This major operation is usually quite successful with a mortality of between 2 and 5 percent. The risk of death from a ruptured AAA is about 50%, even during surgery.
[0010] More recently, instead of performing open surgery in undertaking aneurysm repair, vascular surgeons have installed an endovascular stent/graft delivered to the site of the aneurysm using elongated catheters that are threaded through the patient's blood vessels. Typically, the surgeon will make a small incision in the patient's groin area and then insert a delivery catheter containing a collapsed, self-expanding or balloon-expandable stent/graft to a location bridging the aneurysm, at which point the stent/graft is delivered out from the distal end of the delivery catheter and allowed or made to expand to approximately the normal diameter of the aorta at that location. The stent/graft, of course, is a tubular structure allowing blood flow through the lumen thereof and removing pressure from the aneurysm. Over time, the stent/graft becomes endothelialized and the space between the outer wall of the stent and the aneurysm ultimate fills with clotted blood. At this time, the aneurysm is no longer subjected to aortic pressures and thus will not continue to grow.
[0011] In treating AAAs that involve the aorta-iliac bifurcation, various stent or grafts designs have been placed to support, bridge or reline the vessels in the aneurysm segments. This has often involved multiple self expanding stents or stent grafts such as a large diameter stent or graft in the aortic segment and two smaller stents or grafts placed in each of the iliac arteries. In other designs the stent or graft has been designed to extend from the aortic segment into one branch of the iliac artery. In this case a hole is provided in the stent or graft to accommodate blood flow to the other iliac artery. A second stent or graft may be optionally placed into the other iliac artery and extending into the hole in the first stent or graft provided for iliac branch blood flow.
[0012] It has become apparent through use and clinical experience that the junctions of multiple stents or grafts presented placement problems of component alignment within the body. The stents or grafts being independent of each other caused components to rub against each other causing metal fatigue and flow discontinuities or thrombosis could occur where one component was not aligned with another and protruded into the blood flow. Use of multiple components also caused uneven vessel support such as where overlapping components may have an excess in vessel support as well as unsupported portions of the vessel where gaps occur between components. In the case of grafts, gaps between components cause leaks and may result in continued blood pressure exposure to the aneurysm.
[0013] As a result there remains a need for an alternative one piece stent or graft designs that covers the entire aneurysm segments including the main aortic segment as well as both iliac artery segments. It is also desirable that such a design be collapsible for percutaneous catheter delivery to the treatment site as well as self expandable when deployed from the delivery catheter.
[0014] U.S. Pat. No. 6,409,750 to Hyodoh et al. discloses woven bifurcated and trifurcated stents together with methods of fabrication. Those devices include a first plurality of wires defining a first leg having a first portion and a second plurality of wires defining a second leg having a second distal portion, and a common body having a distal end and a proximal portion, the common body being formed from at least the first and second plurality of wires, the proximal portion of the common body being adjacent to the distal portions of both legs, and both ends of at least one wire from both of the pluralities being located proximate the distal end of the common body. In this design the braided legs are connected only by the common body portion and gaps in metal coverage occur near the juncture of the legs.
[0015] U.S. Pat. No. 7,004,967 to Chouinard et al describes a process for manufacturing a braided bifurcated stent. The process involves the use of two or more braiding machines in which a first discrete plurality of filaments are braided to form a first leg, and a second discrete plurality of filaments are braided to form a second leg. The process involves braiding the first plurality of filaments and the second plurality of filaments together to form the body using another braiding machine. That design results in metal coverage gaps occurring at the outside top portion of each leg and the process requires the use of multiple braiding machines. As with other concepts, the legs are not connected except to the common body portion. There are no common wires from one leg connecting to the other leg so a gap occurs between them.
[0016] There exists a need for a one piece branched stent or graft device that has improved metal coverage for uniform properties and a manufacturing process that is simple and produces a one piece design from a single discrete plurality of wires. There is a need for an improved bifurcated stent or graft that incorporates wires from one leg into the other leg creating a wire hinge and reinforcing the crotch area of the device. There is also a need for a device having the improved characteristics as above and which is also deliverable using a percutaneous intravascular catheter approach having a collapsed configuration for delivery through a catheter and a self expanding configuration when released from the catheter confines. The present development provides such a device.
SUMMARY OF THE INVENTION
[0017] The present concept includes embodiments of catheter-deliverable, endovascular, one piece, multi-region stent or graft devices. Embodiments include bifurcated stent or graft devices for treating abdominal aortic aneurysms involving the aorta-iliac bifurcation. An important aspect of the concept includes a braiding fabrication technique that enables a single bundle or a single plurality of filaments to be used to form a plurality of regions, such as distinct regions of a device including a first region, a second region and a third region.
[0018] One preferred embodiment, for example, includes three regions: the first region and second region form two hinged legs and a third region forms a common body or trunk portion of the device. The third region is braided from a subset of the same single plurality of filaments forming the two hinged legs. In this manner, the stent or graft structure includes a single plurality of resilient filaments that are braided to define a pair of hinged legs and a common body or trunk. The stent or graft has a filament hinge in the crotch area connecting the legs. The filaments are preferably a shape memory metal such as nitinol wire but may be or may include other metals that have an elastic heat settable shape. A polymer filament overlaying version can be used as part of a grafted device.
[0019] As used herein the terms “filament” and “wire” are used interchangeably to describe strands of any suitable type of material including metal and non-metal materials used in aspects of the devices. As used herein, the term “braiding” includes interweaving where appropriate. It will be appreciated the term includes any braid or weave which enables elongation of the device with corresponding reduction in diameter so that the device may be delivered by vascular catheter.
[0020] One preferred method of fabrication includes braiding a plurality of highly elastic filaments supplied from a plurality of braiding spools onto an assembled two-piece or two-part mandrel. The filaments are braided onto a first part of the mandrel to form a first leg. The braiding is stopped and the braid is secured around the mandrel at the first leg distal end (last braided portion) using tape or other clamping means.
[0021] Long loops are formed from each filament exiting the tape/clamp above the distal end of the leg except for filaments that are intended to be the crotch or hinge filaments or wires connecting the legs. The filament loops created are made long enough to later be braided into the common body portion or trunk of the stent or graft. Once the loops are formed, they are coiled or spooled and secured to be out of the way so as not to become entangled in continued braiding. The loop end is taped/clamped to the mandrel on top of the loop starting point. The braiding process is restarted and a second leg is braided over a second part of the mandrel using the same plurality of filaments that were used to braid the first leg.
[0022] Once the second leg has been braided to a desired length, the filaments are taped/clamped to the mandrel and cut from the braiding spools. The braid and mandrel are removed from the braiding machine. The two parts of the two-piece assembled mandrel are separated and the legs and first and second mandrel parts are manipulated in relation to each other to position the legs adjacent each other connected by the hinge filaments. Next, a common body portion or trunk mandrel is attached using leg extensions designed to be inserted into the top of each leg mandrel. The loops that were formed and coiled or spooled are then made available for braiding the common body portion or trunk of the stent/graft.
[0023] At this point, a plurality of trunk braiding options are available and a decision is now required to determine which variation of braiding the trunk is to be selected. One option or choice is to leave the spooled loops in tact and braid both filaments of each loop along the same path. A second choice is to unwind the loops, sever the end of each loop and rewind the two filaments onto separate braiding spools. The two braided loop filaments can then be wound in opposite helical directions.
[0024] In either braiding choice the filaments are spooled and placed on the braiding machine spool carriers and the new mandrel assembly is installed in the braiding machine. The common body portion or trunk is then braided using a major portion of the same plurality of filaments used to braid the legs. The remaining portion of the plurality of filaments or those not used to braid the trunk, are the filaments selected to form the hinge connecting the legs. The braiding machine for braiding the trunk will require a different number of spool carriers as compared to the leg braiding. In the case of the loops being severed into two pieces, for example, the number of braiding machine spool carriers will be much higher in number than if the loops are left intact.
[0025] Aspects of the inventive concept encompass both the method of fabrication of the branched stent or graft device and also the medical device that results from use of the process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a schematic illustration of the braiding of both legs of a branched stent or graft device over an assembled two-part mandrel and showing the formation of loops between the leg segments;
[0027] FIG. 2 is side view of two legs of the device of FIG. 1 after braiding and separation of the two-piece mandrel;
[0028] FIG. 3 is a top view of the device shown in FIG. 2 illustrating the filaments available for braiding the trunk portion of the device;
[0029] FIG. 4 is a perspective drawing of a trunk mandrel prior to assembly to the leg mandrels;
[0030] FIG. 5 is a top view of the legs indicating an area for optional manual braiding;
[0031] FIG. 6 is a side view of one embodiment of a final device;
[0032] FIG. 7 is a side view of an alternative embodiment; and
[0033] FIG. 8 is a schematic top view illustrating a 32 filament braider showing the spool carriers 1 - 32 .
DETAILED DESCRIPTION
[0034] Embodiments will next be described with reference to the drawing figures. Such figures and the accompanying detailed description are meant to be illustrative rather than limiting and are included to facilitate the explanation of aspects of the inventive concepts, including devices and methods of fabrication of the devices.
[0035] Two preferred final device configurations of a branched stent/graft are shown in FIGS. 6 & 7 . These embodiments consist of two leg portions formed with a common body or trunk portion.
[0036] One aspect of the development involves the materials of construction of a device contemplated by the present invention. The device is fabricated from a single plurality of filaments which in the preferred embodiment should include a material which is both resilient and which can be heat treated to substantially set a desired shape. Materials found suitable for this purpose include a cobalt-based low thermal expansion alloy referred to in the field as Elgeloy, nickel-based high temperature high-strength “superalloys” commercially available from Haynes International under the trade name Hastelloy, nickel-based heat treatable alloys sold under the name Incoloy by International Nickel, and a number of different grades of stainless steel. The important factor in choosing a suitable material for the filaments or wires is that the filaments retain a suitable amount of the deformation induced by a molding surface when they are subjected to a predetermined heat treatment.
[0037] One class of materials which also meet these qualifications includes so-called shape memory alloys such as nitinol, an approximately stoichiometric alloy of nickel and titanium, which may also include minor amounts of other metals to achieve desired properties. Such alloys tend to have a temperature induced phase change which will cause the material to have a preferred configuration which can be fixed by heating the material above a certain transition temperature to induce a change in the phase of the material. When the alloy is cooled back down, the alloy will “remember” the shape it was in during the heat treatment and will tend to assume that configuration unless constrained from so doing.
[0038] As an example, without limitation, the device can be illustrated being fabricated from 32 braided nitinol wires having a diameter ranging from 0.0015-0.008 inch (0.0381-0.203 mm), preferably 0.002-0.005 inch (0.051-0.127 mm). The number of wires to be braided may range from 4-200 or more, preferably from 8 to 144 and, more preferably, from 16-72 depending on the particular device characteristics desired.
[0039] FIG. 8 shows a schematic top view illustrating 32 numbered spool carriers on a braiding machine 100 . All the even numbered spool carriers travel in one direction (clockwise) and all the odd numbered spool carriers travel in the opposite direction (counter-clockwise). In addition, as the spool carriers travel in a circular direction, they also change radius of travel about the center of the braider passing inside of one spool carrier and outside of the next spool carrier, thereby forming wires wrapped about a center mandrel that are woven over and under each other in a braided configuration. As the spool carriers are moving, the mandrel is slowly moved in a vertical direction at a controlled speed relative to the braider speed to set the pitch of the braided wires. A typical pitch angle may range from 30-70 degrees from the longitudinal axis of the braided tube in the, as braided, relaxed tube prior to heat treatment. The pitch, pick count (number of wire crossovers per inch, or other lineal measure) and wire diameter, are all variables that can be altered to change the device characteristics as well as the heat set shape.
[0040] Referring now to FIG. 1 , there is shown a tubular mandrel consisting of two parts 20 and 22 . The two-piece mandrel may be assembled together by sliding the two parts over a close fitting shaft and holding them in place with removable end caps (not shown) or by any number of other known suitable means. The braiding of a first region or leg 24 begins at the bottom of the mandrel as indicated in the illustration. The braid starts by attaching, as by taping or clamping, the thirty-two filaments or wires 25 to the mandrel as at 26 . The braiding is begun at a controlled pitch until a desired sufficient length is generated for the first leg 24 near the center of the assembled mandrel. The braiding is stopped and the braided wires are next taped or clamped in place on the mandrel at location 28 .
[0041] After the braiding of the first leg 24 , a hinge zone 30 that represents the portion of the circumference of the first braided leg 24 to be connected directly to the second braided leg 36 is designated. In a preferred arrangement using the illustration of a thirty-two filament or wire braid, this will typically range between about 4 to 8 wires or from 4/32 to 8/32 (⅛ to ¼ of the total) of the circumference of the legs based on the thirty-two filament braid. As an example, 4 wires may be designated as the hinge area 30 . That leaves (32−4) or 28 remaining wires of the braid that will be configured differently.
[0042] Each of the remaining 28 wires leading from the spool carriers as at 32 will have a specific length of filament or wire drawn off the spool to form a loop as at 34 of wire, the loop beginning at the taped mandrel at 28 (end of leg one) and ending back at the same spot at the mandrel. The loop length is predetermined and is at least the length needed to braid the common body portion plus leader length for a braiding machine. The loops 34 are taped to the mandrel over the first tape at location 28 such that the wire leading back to the spool carrier as at 32 is at the same position as it was prior to the forming of the loop. After each loop 34 is secured, the loop material may be spooled or otherwise routed away from the braiding action to prevent the filament or wire from becoming entangled with the next braiding process.
[0043] It will be appreciated that all 32 wires are still oriented radially about the mandrel to begin braiding the second leg 36 from taped filaments as also shown in FIG. 1 . The braiding is started at about mid point on the assembled mandrel and continues until the desired braided length for the second leg 36 has been completed. At this point, both ends of the leg 36 braid are secured to the mandrel by tape 38 and 40 ( FIG. 2 ) or other clamping means. Next, the 32 wires from the spool carriers may be cut about 2 inches (5.1 cm) from the mandrel and the assembled mandrel and braided legs may be removed from the braiding machine along with the 28 loops of braid filament or wire. A typical filament feed spool is shown at 44 mounted on a spool carrier device 42 in a well known manner.
[0044] In FIG. 2 , the central shaft of the mandrel has been removed so that the two halves of the mandrel may be separated and manipulated relative to each other to assume the relative positioning shown in the Figure. For example, the upper mandrel for the second leg may be turned upside down and pivoted about the hinge 30 as shown. The wire loops 34 are shown in the top view in FIG. 3 . Note that the hinge area 30 has no loops as none were formed in this region.
[0045] As indicated, there are several options involving different procedures for forming the body or trunk portion of the device. Versions of preferred embodiments and examples will be discussed next.
[0046] In a first embodiment, the distal ends of the wire loops are not cut or severed and each of the loops 34 is wound with the two wires together onto a spool for braiding the common body or trunk of the stent/graft using double strands. Thus, in the example, 28 spools of two filaments or wires each are available to be placed onto a braider that has at least 28 spool carriers.
[0047] In an alternate embodiment, the wire loops are severed toward the ends to form two wires of substantially equal length from each original loop. The two wires are wound on separate spools for placement on a braider including at least (2 times 28) or 56 spool carriers.
[0048] FIG. 4 illustrates one shape of a mandrel at 50 , which may be solid or hollow, for forming the common body or trunk of the stent or graft. There are two pilot diameters or leg extensions 52 and 54 for insertion into the corresponding two-leg mandrels. The now three-part mandrel is secured together by fasteners or other known means and mounted into the braider in a well known manner for braiding the third region or common body or trunk configuration of the device. The corresponding spools are loaded onto the spool carriers as well.
[0049] FIG. 5 illustrates an area of transition between the stent/graft leg diameter and the trunk diameter where it may be advisable to optionally hand braid about 4-8 wires of each side of the device as at 60 and 62 to bridge the diameter transition prior to beginning of the machine braiding for the trunk. To do this, the spools involved in the hand braiding are removed from the carrier and then returned to the carrier prior to full machine braiding. This optional process provides smaller openings in the stent/graft between wires in the leg to crotch to trunk transition and makes for a less open device lattice.
[0050] As indicated in one embodiment, the 28 pairs of wires are braided together over the mandrel in FIG. 4 for the desired length of the trunk. The braiding is stopped and the filaments or wires are taped or clamped to the mandrel. The wires leading to the spools are cut and the mandrel assembly and braided device are removed from the braider. A finished device in accordance with the embodiment is shown in FIG. 6 . The trunk portion with the mesh of double filament loops is shown at 72 .
[0051] In an alternative embodiment, the severed loops on 56 individual spools of wire are braided together over the trunk mandrel 50 in FIG. 4 for the length of the trunk shown in the embodiment 80 in FIG. 7 as 82 . The braiding is then stopped and the wires are taped or clamped to the mandrel. The wires leading to the spools are cut and the mandrel assembly and braided device are removed from the braider. The finished device 80 has a trunk portion braided from single filaments or wires as is shown in FIG. 7 .
[0052] In the embodiment with the loop braid, the final braiding of the trunk may be accomplished on the same original 32 carrier braider used for braiding the legs, but four of the spools, i.e., every 8 th spool, would be empty. However, this would cause the final device to exhibit gaps between some of the braided wires. This is not as desirable as using a braider with the exact number of needed spool carriers. The gaps can be manually spaced more evenly prior to the final device heat treatment to be discussed in the following. Braiders are available in a wide variety of spool carrier numbers such as 4-200 or more in increments of four carriers as offered, for example, by Steeger USA, Spartanburg, S.C.
[0053] The heat treatment process follows the braiding of the device. In the case where the braiding process was accomplished on a mandrel that equals the final device size, the braid may remain on the mandrel if the mandrel was made of metal or a material able to adequately handle the temperature of the device heat treatment. Heat treatment techniques are generally known to those skilled in the art.
[0054] U.S. Pat. No. 5,725,552 to Kotula et al. incorporated herein in entirety by reference, for example, describes in great detail the heat treatment of braided medical devices made of nitinol wire and the process of confining the device in a mold of the desired final device shape during the heat treatment to set the final device shape in memory. In this regard, it has been found that holding a nitinol fabric or braid at 500-550° C. for a period of about 1-30 minutes, depending on the hardness or softness desired, will tend to set the braid in the shape held during the heat treatment. The materials used to hold the braid in place must be suitable for the temperature range of the heat treatment. For example, the tape if used to hold the braid down may not be suitable, so a metal clamp may be substituted or other means known in the art.
[0055] The devices shown in FIGS. 6 & 7 show a slight amount of flare at the trunk as at 74 and 84 and the leg ends as at 76 and 78 ( FIG. 6 ) which can be molded in during a heat set process by holding the braid in the flared condition during the heat set. Any gaps between wires, such as occurring from braiding 28 wires on a 32 spool carrier braiding machine may also be manually repositioned as desired. After heat treatment, they will retain the repositioned shape.
[0056] If the braiding mandrel is not the desired final heat set shape for the device, the braided device may be removed from the mandrel and placed in a separate mold to produce the desired shape for heat treatment. After heat treatment and shape setting, the braid will resist unraveling without the need for clamps or other retention means. The flared ends of the trunk and legs have been found to assist the device in seating against the artery walls and, in addition, help prevent the wires from catching on other devices that may be passed through the stent or graft. Preferably, the trunk and legs are sized to be somewhat larger (example 5-30%, preferably 15-20%) in the stent/graft relaxed state than the size of the artery in which they are to be placed, to thereby exert outward pressure on the arterial wall to aid in device seating and retention.
[0057] Heat set stents or grafts fabricated by the present braiding process are easily collapsed to a small diameter for delivery through an intravascular catheter lumen by pulling on the trunk and leg ends and stretching the braided wires along the longitudinal axis of the device. Once the device is positioned within the catheter and delivered to the treatment site, the stent/graft may be urged out of a catheter lumen end opening. The released device will self expand to its heat set memorized size or against the arterial wall if the artery is smaller. It will be appreciated that the design of the delivery catheter is somewhat more complex for a branched stent or graft. Examples of such delivery devices are illustrated in detail in patents U.S. Pat. No. 6,409,750 to Hyodoh et al. and U.S. Pat. No. 6,953,475 to Shaolian et al.
[0058] The branched braided configuration may be used as a stand alone stent or the braid may be a component of a graft whereby a polyester or other braided polymer or woven fabric may be added to the outside of the braided metal structure to serve as a sealing surface to the graft. In this type of configuration, the braided metal expansion characteristics urge the graft fabric out against the arterial wall. The fabric may be attached to the braid by suture as an example or by other means known in the graft art. Alternatively, the polyester or other braided polymer or woven fabric may be added to the inside of the braided metal structure and attached by suture.
[0059] Another embodiment of the graft consists of braiding a separate polyester filament using the same techniques as described for the metal filaments or wires. In this embodiment, the braided polymer branched graft material is placed over the heat set metal braid structure and the polymer braid sutured to the metal braid for retention. Alternatively, the branched graft material may be placed within the metal braided structure and sutured to the metal structure. By using similar pitch and pick count for both the metal braid and polymer braid the device can easily collapse and self expand as a unitary device. It should be noted that the underlaying or overlaying polyester or other braided polymer may be fabricated of multiple independent components attached to the metal structure.
[0060] In still another embodiment the graft is made using the same braiding process but the single plurality of filaments used to fabricate the graft consists of a combination of metal and polymer filaments braided together in a single operation. The number of metal and polymer filaments and the ratio of metal to polymer may be altered as desired to obtain sufficient self expansion force and adequate polymer density for sealing of the graft. The process allows for a great deal of flexibility in graft design.
[0061] The present stent or graft braiding process, unlike other techniques, provides for fabrication of a one piece tubular framework device whereby the legs are connected by a hinge and the legs and trunk are fabricated from a single plurality or array of filaments. It will be appreciated that the legs may be the same or unequal in length, the same or unequal in diameter and of a constant (uniform) or vary in diameter along the length thereof (longitudinal axis) as desired in a particular application.
[0062] Although the example device illustrated is for the treatment of an abdominal aortic aneurysm involving the iliac bifurcation, it will be appreciated that the process for braiding and the resulting device is more broadly applicable and not limited to a branched stent or branched graft and a process for fabricating a branched stent or graft for treating a particular condition. There are numerous locations within the body where such a branched stent or graft may be needed and the process is suitable for other configurations as well as the inverted Y stent or graft illustrated. For example, it is anticipated that a side branch can be fabricated off a main braided tubular body in the manner of this invention by creating loops of filaments in a circular pattern at the location of the intended side branch. Such a process involves stopping the braiding machine as braid wires cross the side branch location, creating the loops, and repeating the process until the branch take off area is passed by the braiding. Once the main tube is braided, the loops may be used to braid the side branch.
[0063] This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the example as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself. | Branched braided stent or graft devices and processes for fabrication of the devices are disclosed in which a trunk portion and two hinge leg portions are fabricated in one piece braided from a single plurality of filaments, whereby the legs contain the full plurality of filaments and the trunk portion contains a subset of the same plurality of filaments. The fabrication process involves braiding the hinged legs on a mandrel while retaining loops of filament between the hinged leg portions for subsequent braiding of the trunk portion of the stent or graft. | 0 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a substrate treatment system, a substrate transfer system, and substrate transfer method for use in transferring a substrate such as a semiconductor wafer and an LCD substrate from a cassette station to a process station.
[0002] Recently, sizes of semiconductor wafers have been increased. With the size increase, the wafers tend to be processed one by one in semiconductor device manufacturing processes. For example, in a complex process system (resist coating and developing are performed in one process), substrates are taken out from a cassette one by one, processed in a process unit, and returned to the cassette one by one.
[0003] In a conventionally-used coating and developing process system as shown in FIG. 1, a plurality of cassettes CR are placed on a cassette station 102 . Wafers W are taken out from the cassette CR one by one by means of a wafer transfer mechanism 105 , loaded into a process station 101 , and subjected to a resist coating and developing process. The wafer transfer mechanism 105 comprises a movement unit 103 and an arm 104 . The arm 104 is moved separately by means of the movement unit 103 in the X, Y, and Z axis directions and rotated about the Z axis by a θ angle. The processed wafer W is returned to the cassette CR on the cassette station 102 by the wafer transfer mechanism 105 .
[0004] To prevent particles from attaching onto the wafer W, the resist coating and developing process system is positioned in a clean room where clean air constantly flows downwardly.
[0005] Furthermore, to prevent particles from entering the cassette CR during the conveyance of the cassette, a detachable cover is provided to the opening of the cassette CR. However, when the cassette CR is placed in the cassette station 102 with the cover removed, the cover intervenes in the down-flow of clean air in the process system, creating an air flow which will allow invasion of particles into a process station 101 .
[0006] In the wafer processing step, a washing device (scrubber) is used for washing the front and rear surfaces of the wafer with a brush. The washing device comprises a cassette station 401 and a process station 402 . The process station 402 comprises a center transfer passage 420 , a front-surface washing unit 421 , a rear-surface washing unit 423 , wafer reverse units 427 , 428 , heating and cooling units 425 , 426 , and a wafer transfer mechanism 403 .
[0007] To prevent particles from attaching to the wafer as much as possible in such a washing device, the wafer cassette CR is placed in an airtight chamber (So-called SMIF POD) 413 and the SMIF POD containing the cassette CR is transferred to the cassette station 401 . In the cassette station 401 , the SMIF POD 413 is descended to the wafer transfer portion while the SMIF POD 413 is kept airtight. In the SMIF system, wafers are transferred one by one from the cassette CR of the wafer transfer portion to the process station 402 , washed, and returned to the cassette CR. Thereafter, the wafer cassette CR is ascended and returned to the SMIF POD 413 on the cassette station 401 .
[0008] However, the conventionally-used device has a problem. If a wafer W protrudes from the cassette CR, the protruding wafer sometimes hits against the upper wall of the wafer transfer portion and causes damages when the wafer cassette CR is returned to the SMIF POD 413 . Furthermore, when the wafer protrudes from the cassette CR, the protruding wafer interferes with a mapping sensor 21 b, inducing misoperation of mapping, as shown in FIG. 9.
BRIEF SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide a substrate treatment system, a substrate transfer system, and a substrate transfer method capable of loading and unloading a substrate to a cassette with a cover without disturbing a down-flow of clean air in the cassette station, capable of preventing particles from attaching to the substrate, efficiently, and capable of preventing particles from flowing into the process station side from the cassette station side.
[0010] Another object of the present invention is to provide a substrate treatment system, a substrate transfer system, and a substrate transfer method producing no substrate breakage when a cassette is returned to a cassette mounting portion from a substrate transfer portion.
[0011] (1) A substrate treatment system according to the present invention comprises
[0012] a cassette table for mounting a cassette which has an opening portion for loading and unloading a substrate and a cover detachably provided to the opening portion,
[0013] a process portion for processing the substrate stored in the cassette on the cassette table,
[0014] a transfer arm mechanism for taking out the substrate from the cassette on the cassette table, transferring the substrate to the process portion and returning a processed substrate to the cassette on the cassette table,
[0015] a partition member provided between the transfer arm mechanism and the cassette table, for separating an atmosphere on the transfer arm mechanism side from that on the cassette table side,
[0016] a passage for passing the substrate taken out from the cassette on the cassette table by the transfer arm mechanism and for passing the substrate to be returned to the cassette on the cassette table, the passage being formed in the partition member so as to face the opening of the cassette on the cassette table,
[0017] a cassette moving mechanism for moving the cassette placed on the cassette table so as to be closer to the passage or to be farther from the passage, and
[0018] a cover removing mechanism for attaching or detaching of the cover to the opening portion of the cassette.
[0019] According to the present invention, a down flow of clean air will not be disturbed by open/shut movement of the cassette cover, in the transfer room.
[0020] (2) A system according to the present invention comprises
[0021] a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
[0022] substrate transfer means for loading/unloading a substrate from the cassette through the opening portion,
[0023] a partition member for separating a space on a cassette-side from a space on a substrate-transfer-means side, the partition member having a transfer window for transferring the substrate between the spaces, and
[0024] a cover transfer mechanism for removing the cover from the cassette and transferring the cover to the lower space on the substrate-transfer-means side through the transfer window.
[0025] According to the present invention, the down flow of clean air will not be disturbed by the cover itself in the transfer room when the cover is attached to or detached from the cassette.
[0026] (3) A substrate treatment system according to the present invention comprises:
[0027] a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
[0028] a cassette table on which a cassette is to be mounted,
[0029] substrate transfer means for loading/unloading a substrate through the opening portion of the cassette mounted on the cassette table,
[0030] a partition member for separating a space on a cassette side from a space on a substrate-transfer-means side, the partition member having a window for transferring a substrate between the spaces,
[0031] a cover storage portion formed on a side of the cassette table, facing the space on the substrate-transfer-means side, for storing a cover removed from the cassette, and
[0032] a cover transfer mechanism for removing the cover from the cassette through the transfer window, transferring the removed cover to the space on the substrate-transfer-means side, and storing the cover in the cover storage portion.
[0033] According to the present invention, the down flow of clean air will not be disturbed in the transfer room when the cassette is opened and shut. In addition, particles are prevented from attaching to a substrate in the transfer room and the process chamber 31 A.
[0034] (4) A substrate transfer system according to the present invention comprises,
[0035] a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
[0036] substrate transfer means for loading/unloading a substrate from the cassette, the substrate transfer means being provided in a transfer room whose pressure is set higher than the inner pressure of the cassette,
[0037] a partition member for separating a space on a cassette side from a space on a substrate-transfer-means side, the partition member having a window for transferring a substrate between the spaces, and
[0038] a cover transfer mechanism for removing the cover from the cassette through the transfer window and transferring the removed cover to a lower space of the substrate transfer means.
[0039] According to the present invention, since the inner pressure of the transfer room for transferring the substrate is set higher than the outside pressure, particles can be prevented from entering the transfer room from the outside.
[0040] (5) A substrate treatment system according to the present invention is provided in a clean room. The substrate treatment system comprises:
[0041] a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
[0042] substrate transfer means for loading/unloading a substrate from the cassette, the substrate transfer means being provided in a transfer room whose pressure is set higher than the inner pressure of the clean room,
[0043] a partition member for separating a space on a cassette side from a space on a substrate-transfer-means side, the partition member having a window for transferring a substrate between the spaces, and
[0044] a cover transfer mechanism for removing the cover from the cassette through the transfer window and transferring the removed cover to a lower space of the substrate-transfer-means side.
[0045] According to the present invention, since the pressure of the transfer room is set higher than an inner pressure of the clean room, particles can be prevented from entering the transfer room from the clean room.
[0046] (6) A substrate treatment system according to the present invention comprises:
[0047] a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
[0048] a transfer room separated by a partition member having a first transfer window, for transferring a substrate from the cassette,
[0049] substrate transfer means provided in the transfer room, for transferring a substrate from the cassette, and vice versa, through the first transfer window,
[0050] a cover removing mechanism provided in the transfer room for removing a cover from the cassette through the first transfer window and transferring the cover to a lower space on a substrate-transfer-means side,
[0051] a cover transfer mechanism for removing the cover from the cassette through the transfer window and transferring the removed cover to the lower space of a substrate-transfer-means side, and a process chamber 31 A for processing the substrate transferred from a second transfer window. The process chamber 31 A being provided adjacent to the transfer room, which has a second transfer window for transferring a substrate by the substrate transfer means between the process chamber 31 A and the transfer room.
[0052] (7) A substrate treatment system according to the present invention comprises:
[0053] a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
[0054] a transfer room set at a higher pressure than an inner pressure of the cassette and having a first transfer window for transferring a substrate from the cassette,
[0055] substrate transfer means provided in the transfer room, for transferring a substrate from the cassette, and vice versa, through the first transfer window,
[0056] a cover transfer mechanism provided in the transfer room, for removing a cover from the cassette through the first transfer window and transferring the cover to a lower portion of a space of the substrate transfer means side,
[0057] a process chamber 31 A for processing the substrate transferred through a second transfer window, the process chamber 31 A being set at a higher pressure than an inner pressure of the transfer room, being disposed adjacent to the transfer room, and having the second transfer window for transferring a substrate by the substrate transfer means to the transfer room.
[0058] According to the present invention, since the pressure of the process chamber 31 A is set higher than the inner pressure of the transfer room, particles can be prevented from entering the process-chamber 31 A from the transfer room.
[0059] (8) A substrate transfer system according to the present invention comprises a process portion for processing a substrate and a transfer portion for transferring the substrate to the process portion, and vice versa. In this substrate transfer system,
[0060] the transfer portion comprises
[0061] a mounting portion for mounting a cassette in which a plurality of substrates are horizontally placed,
[0062] a substrate transfer portion provided below the mounting portion, for transferring the substrate to the process portion,
[0063] moving means for moving the cassette between the mounting portion and the substrate transfer portion,
[0064] detection means for detecting a protruding substrate when the cassette moves to the mounting portion from the transfer portion, and
[0065] pushing means for pushing a protruding substrate detected by the detection means into the cassette.
[0066] (9) A substrate treatment system comprises a process portion for processing a substrate under airtight conditions and a transfer portion for transferring a substrate to the process portion under the airtight conditions. In this substrate treatment system,
[0067] the transfer portion comprises
[0068] a mounting portion for mounting an airtight container containing a cassette in which a plurality of substrates are horizontally placed,
[0069] a substrate transfer portion provided in an airtight space communicated with the process portion below the mounting portion,
[0070] moving means for moving the cassette between the table and the substrate transfer portion,
[0071] detection means for detecting a protruding substrate when the cassette moves from the substrate transfer portion to the mounting portion, and
[0072] pushing means for pushing the protruding substrate into the cassette when the protruding substrate is detected by the detection means.
[0073] (10) A substrate transfer system for transferring a substrate comprises:
[0074] a mounting portion for mounting a cassette in which a plurality of substrates are placed horizontally,
[0075] a substrate transfer portion provided below the mounting portion, for transferring a substrate to other system, and vice versa,
[0076] moving means for moving the cassette between the mounting portion and the substrate transfer portion,
[0077] detection means for detecting a protruding substrate when the cassette is moved from the substrate transfer portion to the mounting portion, and
[0078] pushing means for pushing a protruding substrate detected by the detection means.
[0079] (11) A method for transferring a substrate comprises the steps of:
[0080] (a) mounting a cassette in which a plurality of substrates are placed horizontally, on a mounting portion,
[0081] (b) moving the cassette to a substrate transfer portion below the mounting portion,
[0082] (c) transferring the substrate in the cassette to other system at a substrate transfer portion,
[0083] (d) receiving the substrate from the other system into the cassette positioned at the substrate transfer portion,
[0084] (e) moving the cassette containing the received substrate to the mounting portion,
[0085] (f) detecting a protruding substrate when the cassette is moved to the mounting portion, and
[0086] (g) pushing the protruding substrate detected into the cassette.
[0087] (12) A method for transferring substrate under airtight conditions, comprises the steps of:
[0088] (A) mounting an airtight container on a mounting portion, the airtight container containing a cassette in which a plurality of substrates are horizontally placed,
[0089] (B) moving the cassette to a substrate transferring portion positioned in an airtight space below the mounting portion,
[0090] (C) transferring the substrate in the cassette to other system at the substrate transfer portion, the other system being provided in an airtight space communicated with the airtight space,
[0091] (D) receiving a substrate into the cassette positioned at the substrate transfer portion from the other system,
[0092] (E) moving a cassette containing the received substrate to the mounting portion,
[0093] (F) detecting a protruding substrate when the cassette is moved to the mounting portion, and
[0094] (G) pushing the protruding substrate detected into the cassette.
[0095] Additional object and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The object and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0096] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
[0097] [0097]FIG. 1 is a schematic perspective view of a cassette portion of a conventionally-used coating and developing process system;
[0098] [0098]FIG. 2 is a plan view of the entire substrate treatment system according to the present invention;
[0099] [0099]FIG. 3 is a front view of the substrate treatment system;
[0100] [0100]FIG. 4 is a rear view of the substrate treatment system;
[0101] [0101]FIG. 5 is a perspective cross-sectional view of a cassette station, partially broken away, showing a cassette-cover removing mechanism of a first embodiment;
[0102] [0102]FIG. 6 is a perspective view of the casssette-cover removing mechanism of the first embodiment;
[0103] [0103]FIG. 7 is a block diagram of first and second position sensors for detecting the position of the front end portion of a cassette and for detecting a wafer protruding from a cassette, respectively;
[0104] [0104]FIGS.8A to 8 M respectively show a series of procedures of removing a cassette-cover by the cassette cover removing mechanism of the first embodiment, sequentially;
[0105] [0105]FIG. 9 is a plan view of a protruding wafer and a mapping sensor, showing a case where a wafer protruding from a cassette interfers with the mapping sensor;
[0106] [0106]FIG. 10 is a partial perspective view of a cassette station, partically broken away, showing a cassette-cover removing mechanism of a second embodiment;
[0107] [0107]FIG. 11 is an exploded perspective view of a cassette and a cover;
[0108] [0108]FIG. 12 is a perspective view of a cassette-cover removing mechanism and a casset cover of a second embodiment;
[0109] [0109]FIG. 13 is a plan view of the cassette-cover removing mechanism of the second embodiment;
[0110] [0110]FIG. 14 is an exploaded perspective view of the cassette-cover removing mechanism;
[0111] [0111]FIG. 15 is a cross-sectional view of a lock key of the cassette-cover removing mechanisms of first and second embodiments;
[0112] [0112]FIG. 16 is a perspective view showing a clean-air flow in the substrate treatment system;
[0113] [0113]FIG. 17 is a perspective view showing a clean-air flow in the substrate treatment system;
[0114] [0114]FIGS. 18A to 18 E show a series of procedures for removing a cassette-cover according to the second embodiment, sequentially;
[0115] [0115]FIG. 19 is a perspective cross-sectional view of a cassette station, partically broken away, showing a cassette-cover removing mechanism of a third embodiment;
[0116] [0116]FIG. 20 is a perspective view of a cassette-cover removing mechanism of a third embodiment;
[0117] [0117]FIG. 21 is a transverse cross sectional view of a lock key of a cassette-cover removing mechanism of a third embodiment;
[0118] [0118]FIG. 22 is a schematic perspective view of a substrate treatment system;
[0119] [0119]FIG. 23 is a longitudinal perspective view of a cassette station when a cassette is positioned on the cassette table;
[0120] [0120]FIG. 24 is a longitudinal perspective view of a cassette station when a cassette is positioned on a wafer transfer portion;
[0121] [0121]FIG. 25 is a schematic plan view of a protruding wafer and a wafer pushing member for explaining procedures of detecting a wafer protruding of a cassette and of pushing the wafer into the cassette;
[0122] [0122]FIG. 26 is a plan view of a gas-supply nozzle for supplying an inert gas into an airtight container placed on the cassette table of the cassette station; and
[0123] [0123]FIG. 27 is a flow chart of a substrate transfer method according to Embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0124] Hereinbelow, preferable embodiments of the present invention will be described with reference to the accompanying drawings.
[0125] As shown in FIG. 2, the coating and developing process system 1 (provided in a clean room) comprises a cassette station 10 , a process station 11 , an interface portion 12 , first and second sub-arm mechanisms 21 and 24 , and a main arm mechanism 22 . Above the portions 10 , 11 and 12 , air-conditioning fan filter units (FFU) are provided. The fan filter unit (FFU) is responsible for blowing out clean air downwardly, thereby forming a clean-air down flow.
[0126] The cassette station 10 has a cassette table 20 designed for placing a plurality of cassettes CR thereon. The cassette CR contains a predetermined number of wafers W (either 25 or 13 ). A wafer W is taken out from the cassette CR by the sub-arm mechanism 21 and loaded into the process station 11 .
[0127] As shown in FIGS. 3 and 4, the process station 11 has 5 process units G 1 to G 5 . The process units G 1 to G 5 are arranged in a multiple-stage vertical array. Wafers are loaded/unloaded one by one to each of the process units by the main arm mechanism 22 . The interface portion 12 is interposed between the process station 11 and a light-exposure device (not shown). The wafer W is loaded/unloaded into the light-exposure device by the sub-arm mechanism 24 .
[0128] Four projections 20 a are provided on the cassette table 20 . The projections 20 a are responsible for placing the cassette CR at a predetermined position of the table 20 . A cover 44 is provided to the cassette CR to be loaded into the cassette station 10 . The cassette CR is positioned on the cassette table 20 in such a way that the cover faces the process station 11 .
[0129] The process station 11 have 5 process units G 1 , G 2 , G 3 , G 4 and G 5 . The first and second process units G 1 and G 2 are arranged in the front side of the system. The third process unit G 3 is positioned adjacent to the cassette station 10 . The fourth process unit G 4 is positioned next to the interface portion 12 . The fifth process unit G 5 is positioned in the rear side of the system.
[0130] The main arm mechanism 22 has moving mechanisms along the X-axis and Z-axis and a rotating mechanism about the Z axis by angle θ. The main arm mechanism 22 receives the wafer W from the first sub-arm mechanism 21 and then transfers the wafer W to an alignment unit (ALIM) and an extension unit (EXT) belonging to the third process unit G 3 in the process station 11 .
[0131] As shown in FIG. 3, in the first process unit G 1 , two spinner type process units are provided in which predetermined processing is respectively applied to the wafer mounted on a spin chuck in the cup (CP). To be more specific, a resist coating (COT) unit and a developing (DEV) unit are superposed in this order from the bottom. In the same manner, two spinner type process units, COP and DEV units are superposed in the second process unit G 2 . These COT units are preferably arranged in a lower position to facilitate the discharge.
[0132] As shown in FIG. 4, the third process unit G 3 consists of 8 layers, that is, a cooling (COL) unit, an adhesion unit, an alignment(ALIM) unit, an extension (EXT) unit, prebaking (PREBAKE) units, post baking (POBAKE) units. They are superposed in this order from the bottom. In the same manner, the fourth process unit G 4 consists of 8 layers, that is,. a cooling (COL) unit, an extension cooling (EXTCOL) unit, an extension (EXT) unit, a cooling unit (COL), prebaking (PREBAKE) units, and postbaking (POBAKE) units.
[0133] Since the COL and EXTCOL units responsible for low-temperature processing are placed in the lower stage and PREBAKE, POBAKE, and AD units responsible for high temperature processing are placed in the upper stage, thermal interference between the units can be lowered.
[0134] The size in the X-axis direction of the interface portion 12 is almost equal to that of the process station 11 . However, the size in the Y-axis direction is smaller than that of the process station 11 . In the front portion of the interface portion 12 , an immobile buffer cassette BR is arranged. In the rear portion, a peripheral light exposure device 23 is positioned. In the center portion (in the vertical direction), the second sub-arm mechanism 24 is provided. The second sub-arm mechanism 24 has the same moving mechanisms as those of the first sub-arm mechanism 21 The second sub-arm mechanism can access to the EXT unit belonging to the forth process unit G 4 and to the adjoining wafer transfer portion (not shown) provided on the light exposure side.
[0135] In the coating and developing process system 1 , the fifth process unit G 5 may be arranged on the back side of the main wafer transfer mechanism 22 . The fifth process unit G 5 can be moved in the Y-axis direction along a guide rail 25 . If the fifth process unit G 5 is moved, an enough space can be given for performing maintenance and inspection of the main arm mechanism 22 from the back side.
[0136] As shown in FIG. 5, a transfer chamber 31 of the cassette station 10 is shut out from a clean-room atmosphere by means of a first vertical partition board 32 . In the lower portion of the first vertical partition board 32 , a gate block 60 is provided. In the gate block 60 , an upper opening passage (tunnel) 33 a and a lower opening (storage room) 33 b are formed. In the space made of these upper and lower openings 33 a and 33 b , a cover-removing mechanism 47 is provided. In the passage 33 a , a cover 44 is removed from the cassette CR by means of the cover-removing mechanism 47 and stored in the storage room 33 b for a while.
[0137] The cassette station 10 and process station 11 are separated from each other by a second vertical partition board 35 . The second vertical partition board 35 has a communication passage 36 with an open/close shutter 37 .
[0138] In the space between the first and second partition boards, the first sub-arm mechanism 21 is provided. The first sub-arm mechanism 21 comprises an X-axis moving mechanism 42 for moving the arm 21 a in the X direction, a Y-axis moving mechanism 39 for moving the arm 21 a in the Y direction, and a Z-axis moving and rotating mechanism 40 for moving the arm 21 a in the Z direction and rotating the arm 21 a about the Z-axis. A wafer W is taken out from the cassette CR by the first sub-arm mechanism 21 through the passage (tunnel) 33 a of the gate block 60 and loaded into a process station 11 through the passage 36 of the second partition board 35 .
[0139] Hereinbelow, the cassette table 20 and the cover removing mechanism 47 will be explained with reference to FIGS. 6, 7, 8 A to 8 M, 11 and 15 .
[0140] To the cassette table 20 , a movable base 80 is provided which is connected to a rod 82 a of a Y-axis cylinder 82 . On the middle of the upper surface of the movable base 80 , the projection 20 a is provided. When the cassette CR is mounted on the cassette table 20 , the projection 20 a is engaged with a depression (not shown) formed on the bottom of the cassette CR. In this manner, the cassette CR is positioned at a predetermined position. The projection 20 a has a touch sensor function. Hence, when the cassette CR is placed on the cassette table 20 , the presence of the cassette CR is detected by the sensor. The detection signal is sent from the touch sensor to a controller 59 .
[0141] As shown in FIG. 6, the cover-removing mechanism 47 has a shutter board 49 and an elevator mechanism 52 . The elevator mechanism 52 comprises a pair of linear guides 48 , a ball screw 53 , and a motor 55 . The linear guides 48 are provided vertically on sides of both the upper opening (tunnel) 33 a and the lower opening 33 b . Nuts 49 a are provided on the left and right end portions of the shutter board 49 and respectively connected to linear guides 48 . The nuts 49 a are screwed on the ball screw 53 . A gear 54 of the screw 53 is engaged with a movement gear 56 of the motor 55 . The shutter board 49 can be moved through a space in the Z direction from the passage(tunnel) 33 a to the storage room 33 b by means of the elevator mechanism 52 . It should be noted that an air cylinder may be employed as the elevator mechanism 52 .
[0142] The shutter board 49 has a pair of keys 50 . Each of the keys 50 is supported by a θ′ rotation mechanism (not shown). Each of the keys 50 is provided on the shutter board 49 so as to correspond to each of key holes 45 formed in the cassette cover 44 shown in FIG. 11. As shown in FIG. 15, when the key 50 is inserted in the key hole 45 and rotated by an angle of θ′, a lock piece 249 engaged with a key groove of the key hole 45 . In this manner, the cassette cover 44 is locked on the shutter board 49 .
[0143] As shown in FIG. 7, first optical sensors 57 a and 57 b are provided above and below the gate block 60 , respectively, in such a way that the optical axis formed between the sensors crosses the front portion of the cassette CR set on a second position. The second optical sensors 58 a and 58 b are provided above and below the gate block 60 , respectively, in such a way that the optical axis formed between the sensors crosses the front portion of the cassette CR set on a third position.
[0144] The controller 59 controls the movements of the Y-axis cylinder 82 on the cassette table 20 and the motor 55 of the cover-removing mechanism 47 on the basis of detection data sent from the touch sensor 20 a and the first and second optical sensors 57 a, 57 b, 58 a and 58 b.
[0145] As shown in FIG. 8B, the initial position of the cassette CR at which the cassette CR is placed for the first time on the cassette table 20 is defined as “a first position”. As shown in FIG. 8F, the position at which the cassette CR is moved backward from a removed cover 44 is defined as “second position”. Furthermore, the position of the cassette CR when the cover 44 is removed from the cassette CR (shown in FIGS. 8D and 8L) and the position of the cassette CR with the cover 44 removed (shown in FIG. 8G to 8 I) when the wafer W is taken out from the cassette CR are defined as “a third position”.
[0146] The cover 44 of the cassette CR at the first position is located on an entrance (front end portion) of the passage (tunnel) 33 a . The controller 59 detects whether the cassette CR is positioned at the first position or not on the basis of the detection data sent from the touch sensor 20 a and the first and second optical sensors 57 a, 57 b, 58 a and 58 b.
[0147] The first sensors 57 a and 57 b are responsible for detecting the wafer Wh protruding from the cassette without the cover. The second sensors 58 a and 58 b are responsible for detecting the protruding wafer Wh from the cassette CR in order to prevent the interference between the first sub arm mechanism 21 and the wafer Wh.
[0148] Hereinafter, the operation of the cover-removing mechanism 47 will be explained with reference to FIGS. 8A to 8 M and FIG. 9.
[0149] Before the cassette CR is mounted on the cassette table 20 , a shutter board 49 of the cover removing mechanism 47 is positioned on a passage (tunnel) 33 a , as shown in FIG. 8A. The atmosphere inside the chamber 31 is isolated from that of the clean room.
[0150] As shown in FIG. 8B, when the cassette CR is mounted on the cassette table 20 , the projection 20 a is engaged with a depressed portion (not shown) of the cassette bottom. In this manner, the cassette CR is positioned at the first position.
[0151] As shown in FIG. 8C, the cassette CR is moved forward from the first position to the third position. In this way, the cassette cover 44 is pressed against the shutter board 49 . Then, as shown in FIGS. 8D, 11, and 15 , the key 50 is inserted into the key hole 45 and turned to lock the shutter board 49 to the cover 44 . In this manner, the cassette cover 44 and the shutter board 49 are made into one body.
[0152] As shown in FIG. 8E, the cassette CR is moved back from the third position to the second position to remove the cover 44 from the cassette CR. Subsequently, as shown in FIG. 8F, the cover 44 is descended together with the shutter board 49 to house the cover 44 in the storage room (the lower opening) 33 b.
[0153] In the second position, since the front portion of the cassette CR is within the passage (tunnel) 33 a, the atmosphere in the cassette communicates with that of the process system 1 and the cassette CR cannot be raised from the cassette table 20 during the processing of the wafer W. Therefore, it is possible to prevent accident in which an operator mistakenly picks up the cassette CR during the processing and interrupts the operation.
[0154] As shown in FIG. 8G, the cassette CR is then moved forward from the second position to the third position to arrange a front distal end portion of the cassette CR to the place to which the arm 21 a of the first sub-arm mechanism accesses. By virtue of the presence of the cassette CR, the atmosphere of the transfer chamber 31 is shut out from that of the clean room with the result that particles are prevented from entering the process system 1 through the passage 33 a.
[0155] As shown in FIGS. 8H and 8I, the arm 21 a of the first sub-arm mechanism 21 is inserted into the cassette CR and takes out the wafer W from the cassette CR. As shown in FIG. 9, to the arm 21 a of the first sub arm mechanism 21 , a pair of mapping sensors 21 b are movably provided. When the mapping operation is made, these sensors 21 b are designed to move to the distal end of the arm 21 a. Due to these structures, if there is a wafer Wh protruding from the cassette CR, the sensor 21 b hits against the protruding wafer Wh, causing not only misoperation of the mapping but also damage of the wafer Wh. When the wafer Wh protruding from the cassette CR is detected by the first sensors 57 a and 57 b, the detection signal is sent to the controller 59 , the mapping operation is immediately stopped with the sound of an alarm to avoid mutual interference between the protruding wafer Wh and the sensor 21 b . The operator checks the wafer Wh in the cassette CR and returned the wafer Wh to a right position. Thereafter, the operator pushes a reset button to restart the processing operation. The protruding wafer Wh may be pushed into the cassette CR by a wafer pushing mechanism which will be described later (see FIGS. 23 to 25 ) instead of manual operation by the operator.
[0156] The wafer W is loaded from the cassette station 10 into the process station 11 , processed through individual units of the process station 11 , exposed light in the light-exposure device, and returned to the cassette CR of the cassette station 10 , again.
[0157] After completion of processing all wafers W in the cassette CR, the cassette CR is moved back from the third position to the second position. Since the cassette CR is located at the second position, mutual interferes between the cover 44 and the cassette CR can be prevented even if the cover 44 is ascended from the storage room 33 b to the passage 33 a.
[0158] As shown in FIG. 8K, the cover 44 is ascended together with the shutter board 49 until the cover 44 comes to the passage 33 a . Subsequently, as shown in FIG. 8L, the cassette CR is moved forward from the second position to the third position. As a result, the opening portion of the cassette CR is pressed to the cover 44 . In this manner, the cover fits into the opening of the cassette CR.
[0159] Furthermore, as shown in FIGS. 11 and 15, the key 50 is turned to release the lock between the shutter board 49 and the cover 44 . As shown in FIG. 8M, the cassette CR is moved back from the third position to the first position to take the cover away from the shutter board 49 . The cassette CR is then unloaded from the station 10 .
[0160] According to the aforementioned device, the shutter board 49 shuts up the passage 33 a when no operation is made and the cassette CR shuts up the passage 33 a when the operation is made. It is therefore difficult for particles to enter the system from the clean room.
[0161] Since the cassette CR is moved forward and backward toward the passage 33 a by the Y-axis cylinder 82 , it is not necessary to provide the Y-axis movement mechanism to the cover removing mechanism 47 . Therefore, the structure of the cover removing mechanism 47 may be simplified, reducing the amount of particles generated.
[0162] Since the wafer W is loaded to and unloaded from the cassette CR while the front end of the cassette CR is present in the passage 33 a, the trouble that an operator inadvertently picks up the cassette CR from the cassette table 20 during the processing can be fully prevented.
[0163] Hereinafter, the device and method of the second embodiment will be explained with reference to FIGS. 10 - 18 E. The part of the second embodiment common in the first embodiment will be omitted.
[0164] As shown in FIG. 10, the transfer chamber 31 of the cassette station 10 is separated from the atmosphere of the clean room by a partition board 32 made of, for example, an acrylic board and a stainless steel board. On the partition board 32 , four passages 33 are formed. The sub arm mechanism 21 is provided in the transfer chamber 31 . The sub arm mechanism 21 is responsible for load/unload of the wafer W to the cassette CR through the passage 33 . The size of the passage 33 is slightly larger than the opening 43 of the cassette CR. Above the passage 33 , an open-close shutter 34 is provided. The shutter 34 is opened when the cassette CR is present on the cassette table 20 and closed when the cassette CR is not on the cassette table 20 .
[0165] As shown in FIG. 11, the opening 43 is formed in the front portion of the cassette CR. The wafer W is loaded/unloaded to the cassette CR through the opening 43 . The cover 44 is provided to the opening 43 in order to keep the inside of the cassette CR airtight. The cassette CR is charged with a non-oxidative gas as a N 2 gas. Alternatively, N 2 gas charging means may be provided to the cassette table 20 to supply the N 2 gas or the like into the cassette CR from which the wafer is to be taken out. Inside the cover 44 , lock means 44 (not shown) is provided to fix the cover to the cassette CR. On the surface side of the cover 44 , two key holes 45 are formed. The distance between two key holes is desirably a half or more of a lengthwise side of the cover.
[0166] As shown FIG. 10, on the transfer chamber 31 side of the cassette table 20 , four cover storage portions 246 are arranged side by side in the X-axis direction. The storage 246 is a portion for storing the cover 44 removed from the cassette CR.
[0167] On the other hand, four cover removing means 247 are provided to the transfer chamber 31 . The cover removing means 247 are formed in correspondence with the cover storage portions 246 . The cover 44 removed from the cassette CR is stored in the cover storage portions 246 below.
[0168] As shown in FIGS. 12 to 14 , the cover removing mechanism 247 has Z-axis moving means 251 and Y-axis moving means 252 . The Z-axis moving means 251 has tow Z-axis cylinders 254 which synchronously move up and down. A cover transfer member 248 is supported by the Z-axis cylinders 254 . Each of the Z-axis cylinders 254 is supported by the both ends of a supporting member 255 . The supporting member 255 is connected to two Y-axis cylinders 256 . The Y-axis cylinder 256 is provided to the cassette table 20 and designed to move the cover transfer member 248 in the Y-axis direction.
[0169] The coating and developing process system 1 is placed in the clean room in which a clean-air flows downwardly. As shown in FIGS. 16 and 17, a clean-air downflow is also formed within the system 1 to keep individual units of the process system 1 , clean. In the upper portions of the cassette station 10 , process station 11 and the interface portion 12 of the system 1 , air-supply chambers 61 , 62 and 63 are provided. In the lower surfaces of the air supply chambers 61 , 62 and 63 , dustproof ULPA filters 64 , 65 and 66 are provided.
[0170] As shown in FIG. 17, an air-conditioning 67 is provided on the outside or the backside of the process system 1 . Air is introduced into the air-supply chambers 61 , 62 and 63 from the air-conditioning 67 by way of a pipe 68 . The introduced air is converted into clean air by means of the ULPA filters 64 , 65 and 66 provided in the individual air-supply chambers. The clean air is supplied downwardly to the portions 10 , 11 and 12 . The down-flow air is collected at a vent 70 through the air holes 69 appropriately provided in the lower portion of the system. The air is returned to the air conditioning 67 from the vent 70 through the pipe 71 .
[0171] In the ceilings of the resist coating unit (COT),(COT) positioned lower portion of the first and second process units G 1 and G 2 in the process station 11 , an ULPA filter 72 is provided. Air from the air-conditioning 67 is sent to the ULPA filter 72 by way of a pipe 73 branched from the pipe 68 . In the middle of the pipe 73 , a temperature/humidity controller (not shown) is provided for supplying clean air to the resist coating unit (COT) (COT). The controller controls the clean air so as to have a predetermined temperature/humidity suitable for the resist coating step. A temperature/humidity sensor 74 is provided in the proximity of the blow-out port of the ULPA filter 72 . The data obtained by the sensor is fed-back to the control portion of the temperature/humidity controller to control the temperature/humidity of the clean air accurately.
[0172] In FIG. 16, in the side wall of each of spinner-type process units such as COT and DEV, facing the main wafer transfer mechanism 22 , openings DR are formed trough which the wafer and the transfer arm go in and out. Furthermore, to each of the openings DR, a shutter (not shown) is provided to prevent particles or the like from entering the space on the side of the main arm mechanism 22 .
[0173] The amounts of air supplied or exhausted to the transfer chamber 31 are controlled by the air conditioning 67 . By this control, the inner pressure of the transfer chamber 31 is set higher than the inner pressure of the clean room. It is therefore possible to prevent the formation of the air flow from the clean room and the cassette CR to the transfer chamber 31 . As a result, particles are successfully prevented from entering the transfer chamber 31 . Since the inner pressure of the process station 11 is set higher than the inner pressure of the transfer chamber 31 , the formation of air flow from the transfer chamber 31 to the process station 11 can be prevented. As a result, particles are successfully prevented from entering the process station 11 .
[0174] Hereinbelow, movement of the cover removing mechanism 247 will be explained with reference to FIGS. 18A to 18 E. Movement of the cover-removing mechanism 247 is controlled by a controller 59 shown in FIG. 7.
[0175] As shown in FIG. 18A, the shutter 34 is opened and the cassette CR is mounted on the cassette table 20 . Then, the cover transfer member 248 is moved forward to the passage 33 by an Y-axis movement mechanism 256 . Thereafter, as shown in FIG. 18B, the key 249 for the cover-transfer member 248 is inserted in the key hole 45 of the cover 44 and locked to each other through an inner lock mechanism. The key 249 is rotated by an angle θ′, thereby releasing the lock between the cover 44 and cassette CR. In this manner, the cover 44 can be removed from the cassette CR.
[0176] As shown in FIG. 18C, the cover transfer member 248 is then moved back together with the cover 44 in the Y-axis direction to load the cover into the transfer chamber 31 through the passage 33 . The cover transfer member 248 is descended together with the cover 44 , as shown in FIG. 18D, by means of a Z-axis direction moving mechanism 251 to the position facing the storage portion 246 . Then, as shown in FIG. 18E, the cover transfer member 248 is moved forward in the Y-axis direction to store the cover 44 in the storage portion 246 .
[0177] Thereafter, the wafer W is taken out from the cassette CR by means of the sub-arm mechanism 21 and transferred to the process station 11 . After the wafer W is processed in individual process units, the wafer W is returned to the cassette CR. After the processing of all wafers housed in the cassette CR is completed, the cover 44 is transferred from the storage portion 246 to the passage 33 to put the cover on the opening of the cassette CR. The cassette CR is covered with the cover 44 , locked and transferred outside the system 1 .
[0178] In the aforementioned process system 1 , the clean air downwardly flowing in the transfer chamber 31 is not disturbed by the attach and detach movement of the cover 44 from the cassette CR.
[0179] Since the cover is housed in the storage portion 246 , the cover 44 itself does not disturb the down flow of the clean-air in the transfer chamber 31 . Therefore, deficiency of manufactured products due to particles can be reduced.
[0180] A third embodiment of the present invention will be explained with reference to FIGS. 19 - 21 .
[0181] In the system of the third embodiment shown in FIGS. 19 and 20, the cover removed from the cassette CR is rotated about a horizontal axis 384 by 180 degrees by means of a rotation mechanism 382 and then housed in a storage portion 346 . The rotation mechanism 382 comprises a U-shape arm member 381 , a key 349 , a horizontal supporting axis 384 , θ′ rotation motor (not shown), and θ″ rotation motor (not shown). The key 349 is provided to one end of the U-shape arm member 381 . The θ′ rotation motor is used for rotating the key 349 by an angle of θ′. The θ″ rotation motor is used for rotating the key 349 by an angle of θ″, together with the horizontal support axis 384 and the U-shape arm member 381 .
[0182] As shown in FIG. 21, the key 349 is rotatably provided in the arm member 381 . When the key 349 is inserted in the key hole 45 , a lock piece 350 is engaged with a key groove. When the key 349 is rotated by angle θ′, the lock between the cover 44 and the cassette CR is released. In this manner, the cover 44 becomes detachable from the cassette CR. When the horizontal support axis is rotated by angle θ″, a cover 44 is rotated by 180 degrees and housed in the storage portion 346 . As described above, in the system according to the third embodiment, the cover can be housed in a simplified mechanism.
[0183] The embodiments mentioned above are concerned with a resist coating and developing process system used in the photolithography step of the semiconductor device manufacturing process. The present invention is applicable to other process systems. The substrate to be processed is not limited to a semiconductor wafer. Examples of applicable substrates include an LCD substrate, a glass substrate, a CD substrate, a photomask, a printing substrate, a ceramic substrate and the like.
[0184] According to one aspect of the present invention, even if the cover is opened or shut at the opening portion of the cassette, the clean-air downflow will not be disturbed by the open/shut movement. Deficiency in manufactured products due to particles can be reduced.
[0185] According to another aspect of the present invention, even if the cover is opened or shut at the opening portion of the cassette, the clean-air downflow will not be disturbed. In addition, particles can be prevented from attaching to a substrate in a transfer room and in a process chamber. As a result, deficiency in manufactured products due to particles is successfully prevented.
[0186] According to still another aspect of the present invention, no particles flow out from the cassette side to the device side.
[0187] According to a further aspect of the present invention, no particles flow out from the clean room and the cassette to the device side.
[0188] According to a still further aspect of the present invention, no particles flow out from the transfer room to the process chamber 31 A.
[0189] Hereinbelow, a fourth embodiment of the present invention will be explained with reference to FIGS. 22 to 27 . In the fourth embodiment, the present invention is applied to a substrate washing process system having a scrubber for brush-washing a semiconductor wafer W.
[0190] The substrate washing process system comprises a cassette station 401 and a washing process station 402 having a plurality of units. The cassette station 401 comprises mounting portions 414 for mounting airtight containers (SMIF POD) 413 having cassettes C. A plurality of wafers W are stored in each cassette C. In the cassette station 401 , the wafer W is transferred to other system, and to the washing process station 402 , and vice versa.
[0191] On the mounting portion 414 , three mounting boards are provided. Each board has a table 412 for mounting the cassette thereon. Below the mounting portion 414 , a wafer-transfer portion 415 (described later) is formed. On the side of the washing process portion 402 of the cassette station 401 , a passage 410 is provided in the arrangement direction of the table 412 . The cassette station arm 411 is provided to the passage 410 which moves therealong. The wafer W is transferred from cassette C present in the wafer transfer portion 415 to the washing process station 402 , and vice versa, by means of the cassette station arm 411 . The passage 410 is covered with a cover (not shown) and shut out from the atmosphere of the clean room.
[0192] In the middle of the washing process station 402 , a passage 420 is provided. The passage 420 crosses the passage 410 at a right angle. The washing process station 402 comprises a plurality of units arranged on both sides of the passage 420 . To be more specific, on one side of the passage 420 , two surface washing units 421 and thermal system units 422 are arranged side by side. On the other side of the passage 420 , two rear-surface washing units 423 and reverse-turn units 424 are juxtaposed. The thermal system units 422 consist of four units layered one on top of another. The three units from the above are heating units 425 . The lowermost one is a cooling unit 426 . The reverse-turn units 424 consist of two units. The upper reverse-turn unit 427 plays a part of turning over the wafer W. The lower reverse-turn unit 428 has an alignment mechanism of the wafer W other then the turn-over mechanism of the wafer W.
[0193] The washing process station 402 has a wafer-transfer mechanism 403 which is movable along the passage 420 . The transfer mechanism 403 has a transfer main arm 403 a, rotatable and movable back and forth and up and down. The main arm 403 a is responsible for transferring the wafer W to the cassette station arm 411 and to each of units, and vice versa, and further responsible for load/unload of the wafer to each of units. Note that the entire system is covered with a wrapping cover (not shown).
[0194] Hereinbelow, the cassette station 401 will be explained in detail with reference to FIGS. 23 and 24 .
[0195] The cassette station 401 has a substrate transfer portion 415 in an airtight space 416 below the mounting portion 414 . On the mounting portion 414 , an elevator table 412 is provided for receiving the cassette C accommodated in the airtight container 413 . The airtight container 413 has a lock mechanism (not shown) responsible for maintaining the cassette C under airtight conditions. In the cassette C, wafers W are placed horizontally and arranged vertically.
[0196] When the airtight container 413 is placed on the mounting portion 414 and then the lock mechanism is released, the cassette C is ready to move together with the elevator table 412 to the wafer transfer portion 415 . In this case, the space between the airtight chamber 413 and the box forming the airtight space 416 is maintained airtight.
[0197] The elevator table 412 is movably supported by the elevator 430 . The cassette C is designed to move up and down by the elevator 430 between the mounting portion 414 and the wafer transfer portion 415 in the airtight space 416 . The elevator 430 comprises a support member 431 for supporting the elevator table 412 , a ball screw 432 for engaging with the support member 431 , a stepping motor 434 for rotating the ball screw 432 , and a guide member 433 .
[0198] As shown in FIG. 24, the elevator table 412 is descended by the elevator 430 until the cassette C faces the wafer transfer portion 415 . The wafer W is transferred to the process portion 402 by the cassette station arm 411 . Since the passage 410 is covered with a cover 410 a, the passage 410 is an airtight space communicable with the airtight space 416 and further communicable with airtight space, passage 420 , as mentioned above. Therefore, the wafer W is washed in a series of washing processes without exposed to outer air.
[0199] Above the airtight space 416 , a pushing member 435 is provided for pushing the wafer into the cassette from the wafer transfer side. In the proximity of the pushing member 435 , a light emitting portion 436 a and a light receiving portion 436 b (serving as a first detection device) are provided so as to bridge the surface of the wafer transferred from the cassette C, as shown in FIG. 25. If there is a wafer Wh protruding from the cassette C, the protruding wafer Wh intervenes in light traveling from the light emitting portion 436 a to the light receiving portion 436 b . In this manner, the protruding wafer Wh can be detected. To the upper and lower portions on the side of the airtight space 416 from which the cassette is transferred, a light emitting portion 437 a and a light receiving portion 437 b serving as a second detection device are provided. When the light traveling from the light emitting portion 437 a to the light receiving portion 437 b is intervened, subsequent movement is immediately stopped.
[0200] On the back side of the cassette C in the upper portion of the airtight space 416 , a gas supply nozzle 438 is provided. When the cassette C is not present in the airtight container 413 , the airtight container 413 is purged with a non-oxidative gas such as a nitrogen gas supplied from the nozzle 438 to eliminate particles or the like almost completely. The nozzle 438 comprises a nozzle head 439 having a plurality of gas releasing holes 440 arranged along the X-axis and a supporting portion 441 for supporting the nozzle head 439 , as shown in FIG. 26.
[0201] Hereinbelow, the movement of the above-mentioned device will be explained with reference to FIG. 27.
[0202] The airtight container 413 housing a cassette C is loaded into the cassette station 401 and placed on the mounting portion 414 (S 1 ). After the lock between the airtight container 413 and the cassette C is released, the cassette C is transferred onto the elevator table 412 . The elevator table 412 is then descended by the elevator 430 to the wafer transfer portion 415 of the airtight space 416 (S 2 ). A nitrogen gas is supplied from the nozzle 438 to purge the airtight container 413 (S 3 ). While the cassette C is being descended, the position of a wafer is detected by using the first and second sensors 436 a, 436 b, 437 a and 437 b . The detection data is input to the process computer and processed therein. This is called “mapping operation” by which the wafer information, such as a wafer pitch and the presence or absence of the wafer in the cassette C are obtained (S 4 ). The mapping operation is performed to determine whether or not the wafer Wh protrudes from the cassette C by CPU (S 5 ).
[0203] The second sensors 437 a and 437 b detect the protruding wafer Wh. When the second sensors determine that it is difficult to push back the protruding wafer by use of the pushing member 435 , an alarm is turned on (S 6 ) and the movement is immediately stopped (S 7 ). When no protruding wafer Wh from the cassette C is detected, cassette C is ascended (S 8 ).
[0204] During the ascending step (S 8 ), if the first sensors 436 a and 436 b detect the protruding wafer Wh (S 9 ), the ascending of the cassette C is stopped and the pushing member 435 is moved toward the cassette C and pushes the protruding wafer Wh into the cassette C (S 10 ). During the ascending step (S 8 ), all protruding wafers Wh are pushed into the cassette C by the pushing member 435 by checking the wafers W one by one. In this manner, the wafer is successfully prevented from hitting against the upper-wall of the air-tight space 416 while the cassette C is being ascended through the airtight container 413 . Therefore, the breakage of the wafer W is successfully prevented.
[0205] When the cassette C is present in the wafer transfer portion 415 , the wafer W is received by the cassette station arm 411 and transferred to the main arm 403 a of the transfer mechanism 403 (S 11 ).
[0206] The wafer W on the main arm 403 a is then subjected to a series of washing processes according to a predetermined recipe. First, the surface of the wafer W is washed with a brush in the surface washing unit 421 (S 12 ). Subsequently, the wafer W is turned over by the reverse-turn unit 427 or 428 . The rear surface of the wafer W is washed with a brush in the rear surface washing unit 423 . Thereafter, the wafer is turned over by means of the reverse-turn unit 427 or 428 . If necessary, the washed wafer W is dried with heat in the heating unit 425 (S 13 ), and cooled in the cooling unit 426 (S 14 ).
[0207] After a series of processing are completed, the wafer W is transferred from the main arm 403 a to the cassette station arm 411 and housed in the cassette C present in the wafer transfer portion 415 by the arm 411 (S 15 ). The same processing is performed with respect to a predetermined number of wafers W. When the predetermined number of wafers W are processed and housed in the cassette C, the cassette C is ascended (S 16 ) and returned to the airtight container 413 on the mounting portion 414 . The cassette C is locked in the airtight container 413 . The airtight container 413 containing the cassette C is transferred outside of the system (S 17 ).
[0208] The present invention is not limited to the above-mentioned embodiments. Modification of the present invention may be made in various ways. In the above-mentioned embodiments, we explained the example in which the present invention is applied to the washing unit. The present invention may be used in a unit in which other processing other than the washing is made, for example, a resist-coating and developing unit. The present invention may be effective not only when processing carried out in an airtight system but also when a substrate may hit against something or may be caught by something during the movement of a cassette. The present invention may be applied to various transfer units other than the process units. The substrate to be used in the present invention is not limited to the semiconductor wafer. Examples of the substrate include an LCD substrate, glass substrate, CD substrate, photomask, printing substrate and the like.
[0209] As explained in the foregoing, the present invention makes it possible to prevent the breakage of the substrate when the cassette is returned to the substrate transfer portion to the mounting portion, thereby attaining an extremely high yield of the wafers since a protruding substrate is checked by the detection means while the cassette is being moved from the transfer portion to the mounting portion, and the detected protruding substrate is pushed back by the pushing means.
[0210] Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalent. | A substrate transfer system comprising a cassette table for mounting a cassette which has an opening portion for loading and unloading a substrate and a cover detachably provided to the opening portion, process portion for processing the substrate housed in a cassette on the cassette table, a transfer arm mechanism for taking out the substrate from the cassette table, transferring it to process units G 1 to G 5, and returning a processed substrate to the cassette on the cassette table, partition members provided between the transfer arm mechanism and the cassette table, for separating an atmosphere on the side of the transfer arm mechanism from that on the side of the cassette table, a passage formed in the partition member so as to face the opening portion of the cassette on the cassette table, for passing the substrate taken out from the cassette on the cassette table by the transfer arm mechanism and returning the substrate to the cassette on the cassette table, cassette moving mechanisms for moving the opening portion of the cassette on the cassette table closer to the passage or to be farther from the passage, and a cover removing mechanism for detaching the cover from the opening portion or attaching the cover to the opening portion of the cassette. | 8 |
FIELD OF THE INVENTION
The present invention relates to disk drives and, in particular, to the writing of servo tracks on a disk within the disk drive.
BACKGROUND OF THE INVENTION
A disk drive is a device that is commonly employed in computer systems to store data. Typically, a disk drive includes: (1) one or more disks that each have a plurality of concentric tracks on which data is stored; (2) a spin motor for rotating the disk or disks; (3) one or more heads that are each capable of writing and/or reading data to/from a track on a disk; (4) an actuator for moving the head or heads to a desired location adjacent to a disk so that data can be written to the disk or read from the disk; and (5) circuitry for transferring data between a disk and a portion of a host computer system that is exterior to the disk drive, such as a random access memory (RAM).
A disk drive also typically includes a servo system that operates to move a head over a defined track on a disk surface and maintain the head over the defined track until directed to move the head over a different track. The servo system maintains the position of the head over a defined track based upon information that is read from a servo track. In one type of drive, the servo tracks are embedded in or coincident with the user data tracks, i.e., the servo track and the user data track form a single physical track with the servo data interspersed among the user data. Typically, the servo track: (1) identifies the particular track over which a head is positioned; and (2) provides data from which the position of the head relative to the center line of the track can be determined. The identification of the particular track is primarily used when the head is being moved from one track to another track (which is commonly known as a seek operation) to determine when the head is positioned over the desired track. Once the head is over the desired track, the data indicating the position of the head relative to the center line of the track is determined and used to maintain the head over the desired track (which is commonly known as a tracking operation). For example, if the data indicates that the head is positioned to one side of the center line, the servo system causes the actuator to move the head towards the center line.
Presently, the servo tracks are written on the disk surfaces of a disk drive during the manufacturing process by a servo track writer. The servo track writer uses a “push pin” to move the actuator arm and thereby position the heads for writing the servo tracks. To elaborate, the servo track writer uses the “push pin” to move the actuator and, as a consequence, position the heads for the writing of first servo tracks (one per disk surface). Once the first servo tracks have been written, the servo track writer uses the “push pin” to move the actuator and thereby reposition the heads for the writing of the second servo tracks. This process is repeated until all of the servo tracks have been written. As an alternative to using a servo track writer, the drive itself can be used to write the servo tracks in what is known as self servo writing. In this case, a motor associated with the actuator is used to move the actuator arm in discrete steps to write each servo track. In either case, for at least a band or section of contiguous tracks, the heads are either: (1) moved such that the arc that the heads move through from one track to the next track is substantially equal, which results in the track density changing over the band of tracks and is known as the “equal-arc drive format”; or (2) moved such that the distance between adjacent tracks remains substantially constant over the band of tracks, which is known as the “equal-length drive format.”
Regardless of whether a servo track writer or self servo writing is used to establish the servo tracks in a drive or the track format (equal-arc or equal-length) used, the track density measured in tracks per inch (TPI) at a give radius is the same for all of the disk surfaces in the drive.
SUMMARY OF THE INVENTION
The present invention recognizes that the optimal servo track density at a given radius can vary from disk surface to disk surface within the drive and that the present methods of writing servo tracks do not provide for writing the servo tracks on different disk surfaces with different densities at a given radius. The present invention is directed to using a multi-stage actuator within the drive to write servo tracks on two or more disk surfaces within a drive with the track density on each surface at a given radius approaching the optimal track density for that surface. The multi-stage actuator includes a primary actuator for coarsely positioning a head and a secondary actuator for finely positioning the head.
In one embodiment, a disk drive includes at least two separate and substantially parallel disk surfaces that are capable of storing data. Associated with each disk surface is a head for transferring data between the disk surface and the exterior environment. A multi-stage actuator is used to move the heads to desired positions over the disk surfaces for the transfer of data. The multi-stage actuator includes a primary actuator for coarsely positioning the heads relative to the disk surfaces. Associated with each head is a secondary actuator that permits the position of the head to be more finely controlled. The data transfer circuitry of the disk drive, which is normally used to write/read user data to/from the disk, is also adapted to write the servo tracks on the track surfaces. Initially, the tracks per inch (TPI) format that is appropriate for each disk surface on which servo tracks are to be established is determined. While the TPI format may be the same for each disk surface, it is more likely that the TPI format will be at least slightly different for each disk surface. Typical measurements from which the TPI format for a particular surface is determined include the read head width, the write head width and off-track performance based upon a bit error rate and read channel quality factor. Once the TPI format for each disk surface has been determined, the primary actuator is used to position each of the heads for the writing of the first servo track on each of the disk surfaces. The secondary actuators are also used to position each of the heads for the writing of the first servo tracks. Once the heads have been positioned, the first servo tracks are written on each of the disk surfaces. After the first servo tracks are written, the heads are repositioned to write the second set of servo tracks on the disk using the secondary actuators. Because the secondary actuators are capable of operating independently of one another, a different TPI format can be implemented for each disk surface. Once most or all of the servo tracks that can be written for a given position of the primary actuator by using the secondary actuators to move the heads have been written, the primary actuator is repositioned and the process is repeated.
In one embodiment, the position of the actuator arm that carries the heads is adjusted using the actuator motor in a self servo writing operation. In this case, the actuator motor is used to position the actuator arm associated with the primary actuator.
In another embodiment, the position of the primary actuator and, more specifically, the actuator arm that carries the heads (as is part of the primary actuator) is adjusted by a servo writer. In this case, a “push pin” associated with the servo track writer contacts the actuator arm and pushes the arm such that the heads are positioned over the desired locations on the disk surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates a typical disk drive with a multi-stage actuator;
FIG. 1B is a functional side view of certain components in the drive illustrated in FIG. 1A;
FIG. 2 is a functional diagram that shows the secondary actuators that are used to finely position heads relative to the disk surfaces;
FIG. 3 is a function block diagram of certain elements of the disk drive that are used in self servo writing;
FIG. 4 illustrates the initial servo track written on a disk; and
FIG. 5 illustrates the self writing of servo tracks on the first and second surfaces of a disk with the TPI on the first surface of the disk being different than the TPI on the second surface of the disk.
DETAILED DESCRIPTION
FIGS. 1A and 1B illustrate a typical disk drive 20 that includes a plurality of disks. To simplify the description of the invention, it is only necessary to consider a single magnetic disk 22 . It should, however, be appreciated that the invention is adaptable to disk drives that include multiple disks. The disk 22 is capable of storing data in concentric tracks located on a first surface 24 A and a second surface 24 B of the disk 22 . A spin motor 26 is used to rotate the disk 22 about a central axis 28 at a substantially constant rotational velocity.
A first head 30 A is provided for transferring data between the first surface 24 A of the disk 22 and the exterior environment. Similarly, a second head 30 B is provided for transferring data between the second surface 24 B of the disk 22 and the exterior environment. The first and second heads 30 A, 30 B each include a write element for writing data to the disk 22 and a read element for reading data from the disk 22 .
To position the first and second heads 30 A, 30 B over the tracks on the first and second surfaces 24 A, 24 B of the disk 22 so that data can be transferred, a multi-stage actuator 32 is provided. Included in the multi-stage actuator 32 is a primary actuator 34 for coarsely positioning the first and second heads 30 A, 30 B over desired locations on the first and second surfaces 24 A, 24 B of the disk 22 . The primary actuator 34 is comprised of a carriage 36 that includes first and second arms 38 A, 38 B for holding, respectively, the first and second heads 30 A, 30 B. Typically, the first and second arms 38 A, 38 B each include a rigid portion and a flexible, suspension portion. The suspension portion is located between the head and the rigid portion. A voice coil motor 40 is provided for rotating the first and second arms 38 A, 38 B about an axis 42 . To prevent the primary actuator 34 from moving the heads beyond the outer edge of the disks and contacting the interior of the disk housing (not shown), a crash stop 43 is provided.
With reference to FIG. 2, the multi-stage actuator 32 includes secondary actuators 44 A, 44 B for fine positioning of, respectively, the first and second heads 30 A, 30 B. The two secondary actuators are independently controllable. Independent control allows one of the secondary actuators to be implementing a seek operation with one of the heads (i e., moving a head from one track to another track) while the other secondary actuator is implementing a tracking operation with the other head (i.e., maintaining the position of the other head over a desired track). Further, independent control permits each of the secondary actuators 44 A, 44 B to be simultaneously implementing either a tracking function or a seeking function. For purposes of the description, the secondary actuators 44 A, 44 B are both rotary types of actuators. An example of such a secondary actuator can be found in U.S. Pat. No. 5,521,778. It should, however, be appreciated that the invention is equally applicable to a disk drive that uses a secondary actuator that moves a head in a linear manner.
The disk drive 20 further includes a data transfer device that operates in conjunction with the multi-stage actuator 32 to write servo tracks on the disk 22 . With reference to FIG. 3, an embodiment of the data transfer device 46 is illustrated that operates to: (1) use the primary actuator 34 and secondary actuators 44 A, 44 B to position the first and second heads 30 A, 30 B for the writing of servo tracks on the disk 22 ; (2) write the initial servo track on the first surface 24 A of the disk 22 ; (3) use the initial servo track as a reference for writing one or more servo tracks on the second surface 24 B of the disk 22 ; (4) use a servo track written on the second surface 24 B of the disk 22 as a reference for writing further servo tracks on the first surface 24 A of the disk adjacent to the initial servo track; (5) use a servo track, other than the initial servo track, written on the first surface 24 A of the disk 22 as a reference for writing further servo tracks on the second surface 24 B of the disk 22 ; and (6) repeat steps (4) and (5) until all of the servo tracks have been written on the first and second surfaces 24 A, 24 B of the disk 22 .
The device 46 includes some, if not all of the circuitry normally used to read and write user data to and from the disk 22 . Specifically, the device 46 includes an interface 48 that is capable of transferring data between the disk drive 20 and the exterior environment (typically, a host computer). The device 46 also includes a servo pattern generator 49 for providing the servo data that is written to the disk 22 .
The data transfer device 46 also includes channel processing circuitry 50 that is normally used to process and/or manage user data that is to be written to the disk 22 by one of the heads 30 A, 30 B and that has been read from the disk by one of the heads 30 A, 30 B. For writing servo tracks on the disk 22 , the channel processing circuitry 50 is capable of: (1) processing and/or managing servo data that is read from a servo track on the disk 22 by one of the heads 30 A, 30 B and providing the servo data to a servo system; and (2) while the servo data is being read and provided to a servo system, write a servo track to the disk 22 using one of the heads 30 A, 30 B and servo data provided by the servo pattern generator 49 .
The data transfer device 46 further includes a servo system 52 that is normally used in the writing of user data to: (1) control the primary actuator 34 to coarsely posit first and second heads 30 A, 30 B at a desired location over, respectively, the first and second surfaces 24 A, 24 B of the disk 22 ; and (2) control the secondary actuators 44 A, 44 B to finely position the first and second heads 30 A, 30 B, respectively. For the purpose of writing servo tracks, the servo system 52 serves the same functions with the only difference being that servo data and timing data rather than user data is written to the disk 22 . The servo system 52 is susceptible to a number of different approaches, including the parallel loop, master-slave loop, dual feedback loop, master-slave with decoupling approaches.
The data transfer device 46 further includes a controller 54 for coordinating the operation of the interface 48 , servo pattern generator 49 , channel processing circuitry 50 , and servo system 52 . With respect to the servo system 52 , the controller 54 operates to identify the tracks that the primary actuator 34 and each of the secondary actuators 44 A, 44 B should either be moving the heads 30 A, 30 B towards (i.e., seeking) or following (i.e., tracking). As is seen, the controller 54 is connected to the interface 48 , servo pattern generator 49 , channel processing circuitry 50 and servo system 52 .
Having described the disk drive 20 , the writing of servo tracks on the first and second surfaces 24 A, 24 B of the disk 22 is described. Initially, measurements are taken that provide a basis for determining the desirable or optimal TPI for each surface. Among the possible measurements are the read head width, i.e., the width of the track established by a read head or a read/write head when in the read mode of operation. Other possible measurements include the write head width and off-track performance based upon bit error rate and/or the read channel quality factor (which are typically shown in what are known as “bathtub” and “747” curves).
Once the TPI for each surface has been determined, the servo tracks are written on the first and second surfaces 24 A, 24 B with the desired TPIs using either a servo track writer or self servo writing. In the case of self servo track writing, operation commences with the receipt of a command from an exterior device, such as a microprocessor, at the interface 48 directing the disk drive 20 to perform the self servo writing operation. In response to the command, the controller 54 directs the servo system 52 to position the primary actuator 34 against the crash stop 43 for writing the initial servo track 56 A (FIG. 4) on the first surface 24 A of the disk 22 and adjacent to the edge 58 of the disk 22 . By positioning the primary actuator 34 against the crash stop 43 , any positional error in the initial servo track 56 A is substantially reduced, i.e., the end of the track should meet the start of the track with little, if any, radial offset. This, in turn, reduces any positional error in the servo tracks that are subsequently written on the disk 22 , the quality of which is dependent upon the initial servo track 56 A. The controller 54 also directs the servo system 52 to cause the secondary actuator 44 A to position the head 30 A for writing the initial servo track 56 A on the first surface 24 A of the disk 22 . Likewise, the controller 54 causes the head 30 B to be positioned with the secondary actuator 44 B for writing the initial servo track 56 B on the second surface 24 B of the disk 22 (FIG. 5 ).
Once the first head 30 A has been positioned, the controller 54 causes the servo data for the initial servo track 56 A to be transferred from the servo pattern generator 49 to the first head 30 A for writing on the disk. The content and the location of the servo data in the initial servo track 56 A is dependent upon the particular servo mechanisms being implemented in the drive. In one embodiment, the servo data is in the form of servo sectors that are typically located at positions 60 A- 60 H that are regularly spaced from one another. In one embodiment, the servo sectors for a servo track include an index that defines the beginning of the track, a track address, a segment addresses (i.e., a portion of the track), and data (i.e., servo bursts) that can be used to facilitate the following of the track. Included in the servo data of the initial servo track is a clock or timing signal. The clock signal is used by the servo system 52 to locate each servo sector along the track. In particular, the clock signal provides pulses or cycles that can be counted and the count used to establish predetermined spacing between the servo sectors in a servo track.
Once the initial servo track 56 A has been written and the second head 30 B positioned for writing the initial servo track 56 B on the second surface 24 B of the disk 22 , the controller 54 causes the servo data from the initial servo track 56 A to be read and used by the servo system 52 so that the first head 30 A tracks or follows the initial servo track 56 A. By having the first head 30 A follow the initial servo track 56 A and by maintaining the position of the second head 30 B relative to the first head 30 A, the second head 30 B follows a path over the second surface 24 B that substantially mirrors the initial servo track 56 A. In addition, the controller 54 causes the clock or timing signal from the initial servo track 56 A to be used to establish the desired spacing between the servo sectors of the initial servo track 56 B. The controller 54 also causes the servo data for the initial servo track 56 B to be transferred from the servo pattern generator 49 to the second head 30 B for writing on the disk and thereby establish the servo track 56 B on the second surface 24 B of the disk 22 .
In one embodiment, the servo data in servo track 56 A is used as a reference to write not only the initial servo track 56 B but also several other servo tracks on the second surface 24 B of the disk 22 . In this case, once the initial servo track 56 B has been written, the controller 54 causes the servo system 52 to use the secondary actuator 44 B to adjust the position of the second head 301 B for writing the next servo track 56 B′ on the second surface of the disk with the desired TPI. This process is typically repeated to establish a group of servo tracks 59 on the second surface 24 B of the disk with the specified TPI. For a given position of the primary actuator 34 , the number of servo tracks that can be established on the second surface 24 B is limited to the point or close to the point at which the multi-stage actuator 32 is incapable of adequately tracking the initial servo track 56 A and using the information from the initial servo track 56 A as a reference for writing servo tracks on the second surface 24 B of the disk 22 . Generally, this occurs, for a given position of the primary actuator 34 , when the secondary actuator 44 A is at or near the limit of its motion in one radial direction and the secondary actuator 44 B is at or near the limit of its motion in the opposite radial direction.
At this point, one of the servo tracks established on the second surface 24 B of the disk 22 needs to be used as a reference to write further servo tracks on the first surface 24 A of the disk 22 with the desired TPI, which may be different than the TPI of the servo tracks that have been established on the second surface 24 B. Typically, the last servo track 56 B″ written on the second surface 24 B is the furthest from the edge 58 and is used as the reference for writing further servo tracks on the first surface 24 A of the disk 22 . Since the servo track 56 B″ is going to be used as a reference, the track includes the clock signal that is used to position the servo sectors during the writing of the additional servo tracks on the first surface 24 A of the disk 22 . It should, however, be appreciated that any of the servo tracks established on the second surface 24 B can be used as the reference provided the servo track includes the clock signal. In any event, the controller 54 causes the process to be repeated to write a group of servo tracks 61 on the first surface 24 A of the disk 22 with the desired TPI. Specifically, the servo data from the servo track 56 B″ on the second surface 24 B of the disk 22 is used by the servo system 52 to maintain the position of the second head 30 B over the servo track 56 B″, the secondary actuator 44 A positions the first head 30 A over the first surface 24 A to establish the group of servo tracks 61 on the first surface 24 A of the disk 22 with the appropriate TPI for the first surface 24 A. The group of servo tracks 61 contains the same number of servo tracks as the group of servo tracks 59 . In addition, the group of servo tracks 61 includes servo track 62 . After the primary actuator 34 has been repositioned to write a new band of servo tracks, the servo track 62 is used to write a second band of servo tracks on the second surface 24 B in the same manner that the initial track 56 A was used in writing the first band of servo tracks on the second surface 24 B. Consequently, servo track 62 includes the clock signal. Likewise, while primary actuator 34 remains in a fixed position (except for track following adjustments), one of the servo tracks in the second band of servo tracks on the second surface 24 B that includes the clock signal is then used to write another band of servo tracks on the first surface 24 A in the same manner that servo track 56 B″ was used to write servo tracks on the first surface 24 A.
Once all of the servo tracks have been written on the first and second surfaces 24 A, 24 B of the disk 22 for a given position of the primary actuator 34 , the controller 54 causes the primary actuator 34 to be repositioned and the process is repeated. By using the last servo track written on the first surface 24 A of the disk 22 (i.e., the servo track 62 ), repositioning of the primary actuator 34 is substantially reduced, thereby reducing a potential source of error. The controller 54 causes the servo track writing process of using a reference on one surface of the disk 22 to facilitate the writing of servo tracks on the other surface of the disk 22 in an alternating manner to continue until all of the servo tracks have been established on both surfaces 24 A, 24 B of the disk 22 .
After all of the servo sectors have been established on the first and second surfaces 24 A, 24 B of the disk 22 , the clock or timing signal is no longer needed to establish desired spacing between the servo sectors. Consequently, the clock or timing signal present between the servo sectors can be overwritten with user data.
As an alternative to self servo writing, the servo tracks can be written with the use of a servo track writer. In this case, the push-pin of the servo track writer (rather than the actuator motor) is used to establish the position of the primary actuator 34 . Further, the servo pattern generator used to produce the servo data is within the servo track writer rather than the disk drive 20 , and thus, the disk drive 20 need not include servo pattern generator 49 . Otherwise, the process for writing the servo tracks is substantially identical to that described in the self servo writing method.
All of the servo tracks on first and second surfaces 24 A and 24 B of the disk 22 can be coincident with user data tracks. Alternatively, some of the servo tracks (e.g., tracks 56 A and 56 B) closest to edge 58 of disk 22 can be outside the data regions of first and second surfaces 24 A and 24 B that contain the user data tracks, in which case these servo tracks will contain exclusively servo information.
The invention is applicable or adaptable to disk drives in which: (1) there are two or more heads associated with a single surface of a disk and secondary actuators are associated with two or more of the heads; (2) there are two or more heads associated with disk surfaces that are, in turn, associated with different disks within the drive; (3) there are two or more primary actuators, rather than the single primary actuator described above; (4) a primary actuator is utilized that moves a head in a linear manner; (5) a secondary actuator is employed that moves a head in a linear manner; (6) primary and secondary actuators are utilized that involve combinations of rotary and linear actuators; (7) the servo track data is received from the exterior environment; (8) the servo tracks are written away from the center of the disk(s) rather than towards the center of the disk(s); (9) the servo tracks are written out of sequence; (10) only one servo track is written on a surface of a disk at a time; (11) the device 46 that cooperates with the multi-stage actuator to write the servo tracks is a separate device from the device used to write and/or read user data on the disk(s); and (12) a multi-stage actuator is employed that has more than two stages.
The foregoing description of the invention has been presented for purposes of illustration and description. Further, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and the skill or knowledge in the relevant art are within the scope of the present invention. The preferred embodiment described above is further intended to explain the best mode known of practicing the invention and to enable others skilled in the art to utilize the invention in various embodiments and with the various modifications required by their particular applications or uses of the invention. It is intended that the appended claims be construed to include alternate embodiments to the extent permitted by the prior art. | The present invention is directed to utilizing the capabilities of multi-stage actuators in disk drives to write servo tracks that have a variable number of tracks-per-inch (TPI) from head to head, thereby improving both the performance of the drive and manufacturing yields. An appropriate TPI for a particular head has been found to depend on a number of factors that vary from head to head. Consequently, the initial step is to determine an appropriate TPI for at least one of the heads or, more preferably, all of the heads in the drive. The determination typically involves measurements such as read and write width measurements and off-track performance tests for the relevant heads. Once an appropriate TPI format has been determined, the servo tracks are written according to the TPI formats using either a servo track writer or self servo track writing. | 6 |
BACKGROUND OF THE INVENTION
Our new cultivar is the product of a long standing detailed program of hybridizing and selection of dogwood in this instance from native Eastern or Cornus florida seedlings which are carefully controlled, records carefully retained and characteristics analyzed for their differences and outstanding value as potential commercial varieties or cultivars.
As will be understood from the following the program has resulted in many outstanding crosses which ultimately result in particularly attractive vegetative and floral parts, which appear on trees which are very floriferous and regular bearers.
We have selected the particular seedling hereof from certain progeny grown in a cultivated area and as a result have in turn caused the same to be asexually reproduced by stem cuttings. They may also be so reproduced by budding and grafting.
The reproduction and actual growth and selection of the new cultivar took place in the vicinity of New Brunswick, N.J. and has been found to be distinctive as to its winter-hardiness in that area, Plant Hardiness Zone 6.
As will be understood from the detailed description of the invention which appears hereinafter, the new cultivar is in fact outstanding and readily identified as being such thus providing for a new variety which is identified botanically for the purposes hereof as Cornus florida L. var. rubra West and will be known commercially as `D-376-15` the identifier which it was assigned when selected, and has for local identification, the synonym `Rutnam`.
With the foregoing in mind the description which follows will be understood as clearly defining the new cultivar as having the desirable characteristics which are the result of such a program as been here heretofore suggested.
In order to completely disclose the new plant hereof, there is shown herewith in FIG. 1 a typical tree of the new variety to illustrate the density and relative wide spread nature as well as the short height thereof.
FIG. 2 discloses a flower head at the time of flowering and indicates the color and shape of the floral bracts.
Where color is referred to, the color chart of The Royal Horticultural Society is availed of to designate the same, recognizing that the color is as nearly accurate as it is possible to provide by photographic processes.
DETAILED DESCRIPTION OF THE INVENTION
Origin: A seedling selection from the progeny of a controlled cross of two select seedlings each of which originated from a cross of a plant of C. florida var. rubra×a plant of C. florida `Pygmy`, the rubra plants in the two initial crosses being unrelated in origin.
Where reproduction took place: Reproduction took place in the vicinity of New Brunswick, N.J.
Classification:
Botanic name.--Cornus florida L. var. rubra West.
Commercial name.--`D-376-15`.
Tree: Small and rounded in shape. Smaller and more compact than other rubra clones tested, such as `Cherokee Chief`, `Prosser Red`, `Sweetwater`, `Spring Song`, and `Welch's Jr. Miss`, however it is not a dwarf plant. Vegetative and floral parts have been fully winter-hardy at New Brunswick, N.J., Plant Hardiness Zone 6. Very floriferous. Regular bearer.
Trunk: Smooth as a young plant but bark becomes shaggy with age as is typical for plants of C. florida. Color of trunk or bark is 197C (Greyed-Green Group on the R.H.S. Colour Chart of The Royal Horticultural Society, London.
Branches: Medium to stocky, with an unusually high number of side branches which causes the tree to be more compact and heavily branched than other rubra clones, such as `Prosser Red`, currently in the trade. Smooth. 197C (Greyed-Green Group). 2.8 meters in height and 4.03 meters in width as a typical tree.
Leaves: Elliptic, with base broadly cuneate (sometimes mildly oblique) and tip abruptly acuminate.
Length.--8.8 to 16.5 cms. long.
Width at widest point--5.0 to 9.7 cms.
Petiole length.--0.9 to 1.9 cms.
Color.--Upper surface is 137A (Green Group).
Lower surface is 138B (Green Group).
Flower Buds: Medium to large, nearly globose with rather flattened base -- Width ranges from 5.5 to 8.0 mm. Height ranges from 5.5 to 8.5 mm. True flowers are tiny and relatively inconspicuous (each with four minute petals), are borne in dense heads, and are enclosed over winter by four involucral bracts that subtend the true flowers.
Involucral, or floral, bracts:
Color.--When fully expanded: Upper surface 184C (Greyed-Purple Group); about the same as that of the floral bracts of `Prosser Red`, but darker in color than the floral bracts of `Sweetwater` or `Spring Song`, both of which exhibit more white at the base of the floral bracts.
Size and shape.--When the floral bracts are fully expanded, the diameter of the involucre from tip to tip of the opposing inner bracts is about 95.6 mm.; the diameter of the involcure as measured from tip to tip of the opposing outer bracts is approximately 84.3 mm. The average length of the inner and outer bracts is about 46 mm. and 41 mm., respectively. The width of the inner and outer bracts at their widest point is about 37.1 and 40.7, respectively. Length and width of the floral bracts can vary considerably from year to year, but the inner bracts most likely will be both longer and more narrow than the outer bracts in any given year. In general, the outer bracts are nearly equal in length and width and are broadly tapered at the base, whereas the inner bracts are longer than wide and are more narrowly tapered at the base. In general, the floral bracts would be considered obovate with an emarginate tip.
Peduncle length.--Each flower head is borne on a peduncle, the average length of which is about 34 mm. at the time of flowering and/of floral display. The absolute peduncle length will vary slightly from year to year.
Flowering and floral display.--The period of floral display (floral bracts) is typical of that for most plants of C. florida; i.e., occurring in late April and early May in the vicinity of New Brunswick, N.J., and extending for a period of 10-15 days, depending on weather conditions. Anthesis of the tiny, relatively inconspicuous, true flowers commences two to four days after the onset of the ornamental display of the large floral bracts and continues for about seven to ten days, depending on weather conditions. The average number of true flowers per flower head in our new intraspecific hybrid is about 19.7, whereas that of `Prosser Red` is stated to have floral bracts of a similar color, is about 26.2; characteristic is quite consistent from year to year. `D-376-15` is a more compact plant than is `Prosser Red`.
Fruit.--The fruit are avoid, approximately 11 to 14 mm. long and bright red, 45A and/or 46B, (Red Group) as is rather typical of the fruit of most plants of C. florida.
Resistance to:
Insects.--The relative resistance, or susceptibility, of plants of `D-376-15` to the various insect pests known to attack plants of C. florida is expected to be typical of that of plants of most cultivars of C. florida.
Diseases.--The relative resistance, or susceptibility, of plants of `D-376-15` to the various disease organisms known to attack plants of C. florida is assumed to be typical of that exhibited by most plants of C. florida but little information is available at this time. | The plant hereof is notable for its dark red floral bracts and rather small compact form of tree characterized by branching of a densely profuse form being more dense than other clones of C. florida. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of PPA Ser. No. 60/367,036 filed 2002 Mar. 23 by the present inventor
BACKGROUND
1. Field of Invention
This invention relates to split ring coil separating tools, and particularly to improvements to applicant's coil separating tool and method as disclosed in his U.S. Pat. No. 5,957,354 issued Sep. 28, 1999.
2. Prior Art
Applicant's issued patent (FIG. 2, split ring spring clip 66, and FIGS. 4 a , 4 b , 4 c , 4 d , 4 e , 4 f , tool 34) discloses a stitchless fastener which is constructed and operates as follows: a pellet is placed inside a folded high strength material, which creates a bump. Once the coils are separated, the folded bump sandwich is inserted between the coils and into the interior periphery of a split ring (like a key ring) whose coils are so powerful they can only be parted with a prying tool. Tool withdrawal permits the coils to close, thereby trapping the pellet-containing material inside the split ring. The high tensile force generated in use can pull the bump created by the pellet no further than against the coils interior periphery because their powerful resistance to separation prevents escape of the pellet-containing high-strength material from between the coils.
Although the applicant's issued patent discloses the use of two tools for prying the coils apart in the Specification (col. 20, lines 49–51), it is obvious that only one operator's hand is free to hold a tool (not shown) since the other hand must be free to hold a split ring. No provision is made for holding the split ring in a fixed position so that both operators' hands can be occupied with the coil-prying tools. What is more, any attempted use of a conventional holding tool, such as a vise, to stabilize the split ring merely prevents coil separation and/or blocks access into the coils interior via between the coils.
Neither is there any means disclosed in the applicant's issued patent for the split rings to be firmly held in place while the operator overcomes the powerful resistance of the coils to separation from attempted entrance of the tool tips between them. Nor is there any resistance to attempted tool withdrawal from the coils' powerful grip (see Operation below).
Furthermore, nothing in the applicant's issued patent discloses what anti-rotational stabilizing force opposes the operators ¼ turn rotating action after the tool tips have been inserted between the coils. Without such opposition, rotating the tips merely rotates the clip along with the tips as a whole, without any coil separation occurring.
Since there is nothing to guide the tool tips into its correct position, the time that it takes an operator to position the tool tips exactly where necessary prior to insertion between the coils is relatively lengthy because the operator must hunt for the correct position each time. Lack of guidance of the tool tips towards their destination between the coils contributes immensely to undesirably long production cycle times.
There is also nothing to guide the bag corner bumps on its way into its correct position between the coils. The time that it takes an operator to position the bag corner exactly where necessary prior to insertion between the coils is relatively lengthy because the operator must hunt for the correct position each time. Lack of such guidance also means undesirably long production cycle times.
After completion of a loading cycle and withdrawal of the tool tips from between the coils, there is no provision for stopping the tool tips from traveling too far away and holding them in position just outside of the coils in order to be ready for the next loading cycle.
Using two unguided prying tools, uneven and asymmetrical tool tip insertion causes the separation distance between the opposing coils to be non-uniform across the width of the split ring, which interferes with ease of insertion of the bag corner bump.
Due to the tremendous force of their coils, without positively controlling them at the time of prying them apart, the split rings are unstable and dangerous. They can easily and suddenly snap out of position, go flying violently and cause operator injury, or at the least, damage the bag material;
Unlike the disclosure of FIG. 4 e , reference number 28 of applicant's issued patent, in actual practice, the tool tip—after bag corner bump 28 is in its clamped position, but prior to the tool's withdrawal—makes contact with the bag corner, causing it damage.
Objects & Advantages
Accordingly, it would be desirable for a coil-separating tool to:
enable both operators' hands to be free and available for tool and bag handling; efficiently guide both tool tips towards their correct insertion points at the split ring coils; efficiently guide pellet-loaded bag corners towards their insertion points between separated split ring coils; hold the split ring steady while an operator
forces the tool tips between the coils; rotates the coil-separating tools ¼ turn in opposition to the holding force, rotates the tools ¼ turn back to its pre-load position, and withdraws the tool tips from between the coils;
force coils open uniformly across the entire width of the split ring; separate the split ring coils without the tool tips occupying the space reserved for the bag corners; keep the split rings stable and safe while performing its specified tasks, and be withdrawn without damaging the clamped bag corner part with its pellet contents; freely release the split ring with its captured bag corner as a unit, and remain in position to efficiently accept the next assembly cycle.
Further objects and advantages of my invention will become apparent from a consideration of the drawings and ensuing description.
BRIEF SUMMARY OF THE INVENTION
A split ring is placed into and held stationary in the holding compartment at the center of a flat plate. A pair of L-shaped prying tools with round shafts and screw driver-like tips are controlled by a pair of guidance channels which point their prying tips at the parting groove defined by the top and bottom coils of the split ring. A spring strip attached to the flat plate keeps each tool snugly within its guidance channel and its tip aligned with the parting groove by pressing against a flat portion of the tool shafts. The prying tools are free to slide a limited distance along their guidance channels and rotate around their own axis. Their handles overhang the flat plate at each end. The operator pushes on the backs of both handles simultaneously, sending the tool tips between the coils, parting them slightly. The tool tips are prevented from traveling too far into the split ring's interior by either of two alternative stopping means: The first is a collar affixed to the tool shaft which fits partway into a box-shaped widened portion of the guidance channels whose front and rear walls limit the tools' travel in both directions along the guidance channels. The other stopping means is a rivet or pin affixed to the flat portion of the tool tips at a predetermined distance from the tip ends. The rivet or pins' contact with the coils prevents the tips from entering too far into the split ring's interior. In the other direction, the rivet or pins' contact with the spring strips stops the tools. Utilizing the leverage of the L-shaped handles to overcome the power of the coils, the operator rotates them 90-degrees, simultaneously, in opposite clock directions thereby separating the coils a distance equal to the width of the tool tips. The operator now places a bag corner bump between the separated coils and into a portion of the split ring interior unoccupied by the tips. The operator then reverses the handle rotation, which partially closes the coils around the bag corner bump, then pulls the prying tools out from between the coils, away from the holding compartment, which allows the coils to close completely, thereby capturing the bag corner bumps. Now the bag corner and its attached split ring can be lifted out of the clip holding compartment as a unit. Cantilevered suspension of the coil-spreading tool above a work surface with a bracket facilitates bag handling in production.
BRIEF DESCRIPTION OF DRAWING FIGURES
FIG. 1 shows a rear overhead perspective view of the solid cast, molded, or fabricated version of the first embodiment of the coil-separating tool. In this embodiment, each guidance channel has a stop box.
FIG. 2 shows a rear overhead perspective view of the solid cast, molded, or fabricated version of the second embodiment of the coil-separating tool in which there are no stop boxes on the guidance channels.
FIG. 3 shows a rear perspective view of the stop box/stop collar first embodiment of a coil separating tool in its first sequential position; the tips of the prying tools are poised outside of, and a split ring is already loaded inside the clip holding compartment. The one piece solid cast, molded, or fabricated version is shown, as in FIG. 1 .
FIG. 4 continues the sequence from FIG. 3 . The coil-separating tool is in its second position; the tips of the prying tools have entered between the coils and into the periphery of the split ring, which has partially separated coils and a locked-in split ring inside clip holding compartment.
FIG. 5 continues the sequence from FIG. 4 . The coil-separating tool is in its third position; each prying tool has been rotated 90-degrees, which has fully separated the split ring coils.
FIG. 6 shows an overhead perspective view of a coil-separating tool suspended above a work table or base by a suspension bracket. A split ring is attached to the right corner bump of the bag edge. The Prying tools are withdrawn from between the coils and are again in position 1 . The handle that's over the bag is pointing up; the other handle that's not over the bag is pointing down.
FIG. 6 a is the same as FIG. 6 except a second split ring is attached to the left corner of the same bag. The handle directions are now reversed.
FIG. 7 shows an elevation close up view, part breakaway/part section, of the first embodiment (stop box/stop collar not shown) of coil-separating tool 48 . Its prying tool tips are in their first position. The tool comprises two layers, wherein the top layer thickness is equal to the height of the split ring bottom coil (½ the split ring height).
FIG. 8 is the same as FIG. 7 except the prying tools are in their second position wherein the coils are partially separated.
FIG. 9 is the same as FIG. 7 except the prying tools are in their third position wherein the coils are fully separated.
FIG. 10 shows a rear perspective close-up view designated by the dashed line circle in FIG. 6 a , except the prying tools tips are still between the coils prior to their withdrawal. This figure shows how the corner angles of the tips avoid contact with the bag edge.
FIG. 11 shows how the clip attachment edge of the bottom panel of the preferred bag embodiment is typically manufactured to be on the same plane with its rear major upper portion.
FIG. 12 shows a rear overhead perspective breakaway view of the right side only of a solid cast, molded, or fabricated version of the second embodiment of the coil separating tool. It uses rivets or pins and its spring strips and split rings as stops in its first and second positions.
FIG. 13 shows an elevation, part breakaway/part section close up view of the second embodiment of the coil separating tool with its prying tools in their first position, as in FIG. 12 , except both sides are shown.
FIG. 14 is the same view as FIG. 13 except the Prying Tools are shown in their second position (coils partially separated), also as in FIG. 21 .
FIG. 15 is the same view as FIG. 13 except the Prying Tools are shown in their third position (coils fully separated).
FIG. 19 shows an overhead exploded view of the two-layered version of the coil-separating tool first embodiment that has stop boxes.
FIG. 20 shows an overhead exploded view of the two-layered version of the coil-separating tool second embodiment that has no stop boxes.
FIG. 21 shows a rear overhead perspective breakaway view of the left side only of a solid cast, molded, or fabricated version of the second embodiment of the coil separating tool, the same embodiment as FIG. 12 . It is in the same second position as FIG. 14 .
FIG. 22 shows side elevation, part breakaway, and part section view of the coil-separating tool suspended above a work table or base by a suspension bracket. The split ring coils are fully separated. The bag corner bump is entering the space between the coils, while the rear portion of the bag is being supported by a suspended tube. The space under the coil-separating tool (or support tube) provides clearance for the major upper portion of the bag, which can dwell forward, under the tool (broken lines), or rearward (solid lines) under the tube, while the split rings are being attached.
FIG. 23 shoes sequentially how steel wedges are used as an alternate coil separation tool.
DETAILED DESCRIPTION OF THE INVENTION
Each coil-spreading tool comprises a:
flat plate 11 of an appropriate material and size, which can be molded, cast, or fabricated in one piece ( FIGS. 1 , 2 ), or it can be layered sheet materials ( FIGS. 19 , 20 ). In the layered embodiment, the top layer 43 , 46 , 49 , 50 thickness is equal to the bottom coil 70 thickness (½ the split ring 66 height. See Guidance Channels 17 below and FIGS. 7 , 13 , 22 ). The floor plates 45 , 51 can be any appropriate thickness; clip holding compartment 10 recessed into and centered on flat plate 11 , its floor recessed a distance equal to the thickness of bottom coil 70 of split ring 66 when placed therein. Split Ring 66 (in this embodiment, round, 1 inch OD) should fit snugly in clip holding compartment 10 ; front platform area ( FIG. 3 , bracket 40 ) surrounds the front half of clip holding compartment 10 , is flat and serves to guide bag corner 20 ( FIGS. 6 , 6 a , 10 , 22 ) with its bumps into its destination at the 12 o'clock position between the coils ( FIG. 5 , arrow 29 , and FIG. 22 ) of split ring 66 , once they are separated. Flat surface 11 of front platform area 40 is advantageously aligned with parting groove 71 ( FIGS. 7 , 13 , 22 ) of split ring 66 .
After coil separation ( FIG. 22 ), front platform area 40 remains aligned with gripping surface 76 of bottom coil 70 . Forward edge 12 ( FIGS. 6 , 6 a , 22 ) of front platform area 40 , including forward edge 18 of suspension bracket 15 , should be sized and shaped to fit into wedge-shaped bag space 83 formed by the leading half of gusset width 16 and bag major upper portion 58 behind bag clip attachment edge 13 (see cantilever suspension bracket 15 below). Accordingly, front platform area 40 must be shorter than ½ the bag gusset width 16 ( FIG. 11 ) or corner bumps 20 with leading edge 13 cannot reach their destination inside the coils of split ring 68 ;
rear platform area 42 ( FIGS. 3 , 4 , 5 ) begins where front platform area 40 ends, and comprises;
guidance channels 17 ( FIGS. 1 , 2 ), a pair, located one on each side and opening into clip holding compartment 10 at the 3 o'clock and 9 o'clock positions. Channel 17 width is such that it permits only lengthwise movements of prying tool 19 . Channel 17 depth is equal to split ring 66 bottom coil 70 height (½ the shaft diameter), so that prying tool tip apex 33 ( FIGS. 7 , 13 and below) can be aligned, prior to coil separation, with groove 71 located between and defined by rounded perimeter 73 of split ring coils 68 and 70 . Guidance channels 17 are advantageously offset at an angle from clip holding compartment 10 , sloping away from front platform area 40 . The angle should be such that no part of prying tools 19 will come close enough to bag bottom edge 13 to damage it, no matter what its position. each guidance channel 17 having a:
stop box 52 , a widened portion of guidance channel 17 that receives and cooperates with stop collar 27 ( FIGS. 3 , 4 , 5 ) to prevent the prying tool tips 34 from entering interior coil space 54 too far inside split ring 66 , and keeps them close to clip holding compartment 10 , in position, ready for the next split ring 66 . No stop box 52 is needed ( FIGS. 2 , 20 ) if alternative stop 28 ( FIGS. 12 , 13 , 14 , 15 , 21 ) is used; Prying Tool 19 , one occupying each guidance channel 17 ; each prying tool 19 comprising a;
rod shaft 21 having a diameter (x) equal to the height of abutted coils 68 , 70 of split ring 66 ( FIGS. 7 , 13 ); each rod shaft 21 having at its end nearest to the split ring holding compartment 10 a:
symmetrical tip 34 ( FIGS. 3 , 10 , 12 , 21 ) with back-to-back surfaces 32 ( FIGS. 7 , 13 , 22 ) that slope at equal angles from full shaft 21 diameter to a blunt knife edge apex 33 —like a screw driver with a “cabinet” style (straight sides, no flair) tip, its width x ( FIGS. 9 , 15 ) being the same as shaft 21 diameter, which is the distance the coils 68 , 70 are to be separated. For example, a shaft diameter/tip width of 4-mm (0.1575) requires a split ring having approximately the same total thickness. The tool tip corners 36 ( FIG. 10 ) are tapered at an angle equal to the offset angle of the guidance channels 17 ( FIGS. 1 , 2 ). Unless so tapered, the tip corners would contact and damage edge 13 at bag corner bumps 20 when rotated back into Position 2 just prior to tool withdrawal (see Operation below);
each rod shaft 21 having at its other end a:
handle 44 ( FIGS. 3 , 4 , 5 , 12 , 21 ) projecting at a right angle to its shaft 21 axis (not shown) and perpendicular to knife edge apex 33 of tip 34 . Handle 44 must be sufficiently long relative to shaft 21 diameter to generate the leverage necessary to pry apart split ring 66 coils 68 , 70 (see Operation). Care must be taken in the tool design that handle 44 makes no contact with flat plate 11 or table top or base 80 when in its down position (broken line handle 44 );
each rod shaft 21 having at its middle portion a:
stop collar 27 ( FIGS. 3 , 4 , 5 ) affixed with a set screw 47 inside a threaded hole or a slot cut into the shaft, or a rivet or pin (not shown) that enters a drilled hole; or alternatively a stop rivet or pin 28 ( FIGS. 12 , 13 , 14 , 15 , 21 ) which is affixed to tip 34 at a distance from tip apex 33 such that its contact with coils 68 and 70 prevents the further entrance of prying tool 19 into split ring 66 interior 54 . Total rivet or pin 28 length through the tool tip cannot exceed shaft 21 diameter so that it fits snugly into guide channel 17 when in Position 1 (see Operation). Rivet or pin 28 also cooperates with spring strip 56 ( FIGS. 12 , 13 and below), by preventing excessive outward travel of prying tool 19 , thus keeping it in Position 1 . Whichever prying tool stop embodiment is most cost effective for a given production run (see Operations) should be selected;
spring strips 56 for:
keeping prying tool tip apex 33 horizontally aligned with parting groove 71 ( FIGS. 7 , 13 ) when clip holding compartment 10 contains split ring 66 (Position 1 ) by pressing against the upward facing flat sloping surface 32 while also causing handles 44 of Prying Tools 19 to point straight up or down (see Operation); keeping prying tools 19 firmly inside guidance channels 17 by maintaining constant downward pressure, yet yielding upward, thereby allowing shafts 21 to lift when prying tools 19 are pushed by the operator into position 2 ( FIGS. 8 , 14 ), and rotated ¼ turn to separate the coils into Position 3 ( FIGS. 9 , 15 ); stopping the outward travel of alternative stop 28 ( FIGS. 12 , 13 ).
The Necessity of Suspending Coil Separation Tool 48 ( FIGS. 6 , 6 a , 11 , 22 )
The preferred type of bag disclosed in the applicant's issued U.S. Pat. No. 5,957,354 (entitled Back Sack, trade named Baxac™), as manufactured ( FIG. 11 ), has its bag bottom 16 flat against major upper portion 58 , making bag bottom edge 13 inaccessible for attaching split rings 66 at corner bumps 20 . To be accessible, edge 13 must be separated from bag upper portion 58 by suspension to form wedge-shaped space 83 .
Coil Separating Tool 48 Suspension Bracket(s) 15 ( FIGS. 6 , 6 a , 22 )
With coil separation tool 48 suspended and occupying wedge-shaped space 83 ( FIG. 22 ), edge 13 can approach its destination to have split rings 66 attached, and provides bag upper portion 58 places to dwell.
A single coil separating tool 48 suspended by bracket 15 cantilevered from one side allows bags to be fed in laterally from the open side. Two brackets, one on each side (not shown) would be sturdier, but permits only vertical bag feeding. Either way, there should be enough lateral space underneath bracket 15 for coil-separating tool 48 to reach both left ( FIG. 6 a ) and right ( FIG. 6 ) bag corners 20 without interference of the widest anticipated bag. Otherwise, bracket 15 could be made laterally adjustable to match different bag widths (not shown). When deciding suspension height (vertical space 60 ), care should be taken to avoid contact between worktable surface or base 80 and tool handles 44 regardless of their position (see Operation).
Alternatively, two short bracket coil separating tools 48 mounted in tandem (not shown), one for each side of the bag, would enable operators to achieve faster assembly cycle times. And if mounted adjustable for distance between them, different bag widths would be accommodated.
Rear Bag Bottom Support 82 ( FIGS. 6 , 6 a , 22 )
In order for both operators' hands to be free to operate handles 44 of coil separating tool 48 (see Operation), rear bag edge 14 must also be supported. Rear support tube 82 can provide this, as can a duplicate of suspension bracket 15 , or the front edge of a low shelf or platform (not shown). Whatever the rear support method, cantilevered mounting (not shown) on the same side as cantilevered bracket 15 , or its equivalent, would provide the advantage of a fully open opposite side for easier, unobstructed lateral bag feeding and facilitate the rearward dwelling place option 58 .
Operation
POSITION 1 is the loading position. With the help of spring strips 56 , the operator points one handle 44 up, the other down, both perpendicular to coils 68 and 70 of split ring 66 . If the bag forward position is used (broken lines 59 of FIGS. 6 , 6 a , 22 ), which handle 44 is up depends on which bag corner is having its split ring 66 attached. The bag and tool handle positions must be coordinated to avoid their making unwanted contact with each other in vertical space 60 underneath coil separating tool 48 ; specifically, when attaching split ring 66 to the left corner ( FIG. 6 ), the right handle must point up, and vice versa. Coordination is unnecessary if the bag rearward position is used (solid lines 58 , FIGS. 6 , 6 a , 22 ). Both prying tool tips 34 must be outside clip holding compartment 10 in order for it to be loaded. The operator now places a split ring 66 snug and flat into clip holding compartment 10 with the ring's Z-shaped part 72 at the 6 o'clock position ( FIG. 3 ). Prying tool tips 34 will then be correctly poised at the 3 and 9 o'clock positions. Once in Position 1 and loaded, the operator, with open hands, simultaneously strikes the backs of both handles 44 gently, but sharply enough to send tips 34 towards each other ( FIG. 3 , arrows 35 ) and into interior coil space 54 as far as their respective stop collars 27 , or rivets (or pins) 28 permit ( FIGS. 14 , 21 ). This lifts coil 68 partially away from bottom coil 70 , which is now safely locked inside clip holding compartment 10 by prying tools 19 . Coil separating tool 48 is now in . . .
POSITION 2 , ready to overcome the power of the coils for full coil separation, which requires the upward pointed handle 44 to be rotated down 90-degrees (¼ turn) towards the operator ( FIG. 5 ), so that it is horizontal, and downward pointed handle 44 to be rotated up 90-degrees (¼ turn), also towards the operator, so that it, too, is horizontal. Coil-separating tool 48 is now in . . .
POSITION 3 when tool tips 34 are vertical (and the handles horizontal). The coils are now fully separated and ready to receive bag corner bump 20 between them ( FIGS. 5 , 22 ). As long as the tips remain perpendicular to the coils in this loaded position, their tremendous energy keeps them secure and stable. This frees the operator to use both hands to feed a bag corner bump 20 into position between open coils 68 and 70 .
If coil separation tool 48 is suspended on only one side ( FIGS. 6 , 6 a , support 22 ), bags can be fed in from the opposite open side, or vertically. If two supports 22 are used, one on each side (not shown), only vertical feeding is possible. The operator now directs bag major upper portion 58 either towards him/her self, under bracket 15 , to dwell during clip attachment, as in FIGS. 6 , 6 a , and FIG. 22 (broken lines 59 ), or towards the rear (solid lines), under rear bag support 82 .
Once a bag corner bump 20 is in that portion of interior coil space 54 adjacent to front platform area 40 and unoccupied by prying tool tips 34 , the operator returns his/her hands to handles 44 and reverses the sequence by rotating them back to Position 2 . This allows the coils to partially close on bag corner bump 20 , and then the operator pulls handles 44 in opposite directions, out from between the coils and back into Position 1 . This allows the coils to fully close on the bag corner bump, thereby capturing it. The bag corner and split ring assembly is then free to be lifted out of the clip holding compartment as a unit.
CONCLUSION, RAMIFICATIONS, & SCOPE
Thus, it is clear that the present split ring coil separating tool and method invention:
Enables both operators' hands to be free for tool and bag handling; Keeps both prying tool tips ready near their correct insertion points at the split ring coils; Guides both tool tips towards their correct insertion points at the split ring coils; Holds the split ring steady hands free while an operator
Forces the tool tips between the coils; Rotates the coil prying tools ¼ turn; Forces the coils to separate uniformly across the width of the split ring without the tool tips occupying the space reserved for the bag corners; Rotates the tools ¼ turn back to its pre-load position; Withdraws the tool tips from between the coils without damaging the clamped bag corner with its pellet contents;
Releases the split ring with its captured bag corner as a unit; Remains in position to efficiently accept the next assembly cycle; Keeps the split rings stable and safe while performing its specified tasks.
Although the above description sets forth specific embodiments of the invention, it should not be construed as limitations on its scope. Many variations are possible. For example, the split ring coils 68 and 70 could be separated by different prying techniques, such as steel wedges ( FIG. 23 ) that enter between the coils and exit without the need for rotation. Such wedge tips would permit various coil separation distances depending on how far they enter between the coils, and thus accommodate different split ring sizes. Or, instead of the prying tools being operated manually, they would be moved by mechanical means, such as solenoids or actuators. And they could be triggered by optical, or other type sensors, so that when an operator gets close to the split ring with a bag corner (or the like), the coils would separate automatically and close when its destination is reached. Or, the prying tools could be operated via mechanical linkage, with or without electric, pneumatic, or air assist by an operator's foot or knee, so their hands are always free. The split ring holding compartment could be a modified flange attached to a flat plate, and the guidance channels could be defined by angle strips similarly attached. An alternate way to spread the coils utilizes very coarse threaded sheet metal type screws, which taper to a sharp point. The more turns of the screw, the further apart the coils are separated. The shape of the split rings could vary, such as having one or more straight sides, or more than two prying tools might be needed, not only to accommodate different split ring shapes, but to facilitate the entrance between the coils of two or more material packets with pellets folded within approaching the split rings from different sides. Such an embodiment could find use in the fashion industry, for example, where the split rings would be valued as being both decorative and functional. A hand-held embodiment designed to operate with only one hand could be used in the field for attaching banners and other displays. This embodiment would enable an operator to move the tool towards the fixed in place pellet-loaded material instead of the reverse, as described above.
Accordingly, the scope of the invention should be determined not by the embodiments presented herein, but by the appended claims and their legal equivalents. | A guidance channel radiating from each side of clip holding chamber centered on a flat plate. A prying tool slideably and rotatably held within each guidance channel by a spring strip. A split ring held snugly within the holding chamber. The tool tips are forced between the split ring coils, which are separated further by simultaneous rotation of the prying tool handles 90-degrees in opposite clock directions. A pellet placed inside folded bag material forms a bump. The material with bump is placed between the separated coils into the split ring interior. Reverse 90-degree handle rotation partly closes the coils around the bump. Withdrawing the prying tools completely allows the coils to fully close, capturing the pellet-containing material. Tool stops prevent the tool tips from entering the split ring interior too far into or away from the clip holding chamber. Suspension of the tool and bags facilitates production. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based on and claims priority to U.S. Provisional Patent Application No. 61/671,301, filed on Jul. 13, 2012, the disclosure of which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
The invention pertains to a railroad track circuit providing for the positive detection of broken rails despite the presence of factors that would otherwise preclude such detection. Prior art railroad track circuits that monitor for broken rails have been negatively affected by sneak paths that arise from the presence of negative return cross-bonding as applied between parallel tracks in electrified territory.
BRIEF SUMMARY OF THE INVENTION
The railroad track circuit of the present invention provides accurate broken rail detection, which is ensured through the provision of two track relays, or devices that function as track relays. These devices are uniquely arranged so as to render the track circuit immune from sneak paths that interfere with the function of the prior art track circuits.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a prior art arrangement and operation of a track circuit;
FIG. 2 shows a prior art de-energization of a track circuit due to the presence of a train;
FIG. 3 shows a prior art de-energization of a track circuit due to the presence of a broken rail;
FIG. 4 shows the arrangement of impedance bonds and flow of traction return current in a prior art track circuit;
FIG. 5 shows a typical cross-bonding arrangement as applied in multiple-track territory per the prior art;
FIG. 6 shows sneak paths caused by cross bonding in multiple track territory per the prior art;
FIG. 7 shows sneak paths caused by grounding between adjacent power substations per the prior art;
FIG. 8 shows the normal flow of current through a track relay per the prior art;
FIG. 9 shows the flow of current through a track relay in a track circuit with a broken rail via a sneak path per the prior art;
FIG. 10 shows the invention's arrangement of two track relays providing immunity from sneak paths;
FIG. 11 shows the normal flow of current through the two track relays of the present invention; and
FIG. 12 shows the flow of current through one of the two track relays of the present invention in a track circuit with a broken rail.
DETAILED DESCRIPTION OF THE INVENTION
The track circuit was invented in the 1870's. Its function is to detect whether a defined length of track, or “block”, is clear of trains, thereby allowing following trains to proceed safely at high speed. FIG. 1 illustrates a typical track circuit. A track circuit includes the two running rails 1 . A local power supply feeds an energy source 2 connected to one end of a block isolated by insulated rail joints 3 . A relay or equivalent device 4 is connected to the end opposite the energy source 2 . Track circuit current 5 flows from the energy source 2 through the rails 1 to the track relay 4 , thereby energizing it.
FIG. 2 illustrates track circuit operation in the presence of a train. The train wheels 6 short-circuit the current 5 away from the relay, thereby de-energizing it. FIG. 3 illustrates track circuit operation with a broken rail. The break 7 blocks the flow of current 5 , thereby de-energizing the track relay 4 . An energized track relay thereby ensures that the block is both clear of train and that it contains no broken rails. These conditions being met, safe train operations could be ensured.
The subsequent development of electric propulsion for trains presented complications for track circuits because the rails were now also required to provide a return path for propulsion current back to the substations. FIG. 4 depicts the provision of impedance bonds 8 , an equalizer bar 9 , and side leads 10 to provide such a path for the propulsion current 11 to return to the substation(s) that generated it. Impedance bonds typically consist of two concentrically but oppositely wound copper coils arranged so as to provide nearly zero impedance to the return propulsion current while presenting an impedance of several ohms from rail to rail. The impedance to the return current is near zero because the opposing orientation of the two windings effect a cancellation of the magnetic fields induced by the equal currents flowing in each. This is referred to as impedance bond “balance.” The energy source 2 is adjusted so as to overcome the rail-to-rail impedance to a degree sufficient to energize the track relay.
Where there are multiple tracks or other complex track arrangements, the return paths must be interconnected via “cross-bonding.” FIG. 5 illustrates the concept of cross-bonding in which the equalizer bars of two tracks are connected by cross bonds 12 . The cross bonds 12 are, in turn, connected to the substations 13 . The presence of cross bonds gives rise to a significant problem in connection with broken rail detection. This is because when a rail is broken, the combination of the cross bonds and parallel tracks comprise a “sneak path” whereby the track circuit energy effectively flows around the rail break rather than being blocked by it. FIG. 6 illustrates the sneak path 14 . The current flows through the impedance bonds within the track circuit having the break 15 , then through the impedance bonds of adjacent track circuits 16 and the cross bonds 12 . Because this current flows through the impedance bonds of adjacent track circuits 15 in balanced mode, these impedance bonds present virtually no impedance to this current. Therefore, such a sneak path can exist even if many track circuits intervene between cross bonds 12 . FIG. 7 illustrates a similar sneak path that may be caused by the ground impedance 17 between adjacent substations 13 which are intentionally grounded.
FIG. 8 details the flow of track circuit current 5 through the track relay 4 in an unoccupied track circuit in the absence of a broken rail, i.e., the normal condition. In contrast, FIG. 9 depicts the flow of track circuit current 5 in the presence of a broken rail 7 through the track relay 4 via the sneak path created by the cross bonding 12 , the equalizer bar 9 , the impedance bond 8 and a side lead 10 . In this circumstance, the track relay 4 would be falsely energized despite the presence of the broken rail. This would give rise to a hazardous situation because the broken rail would not be detected.
The present invention overcomes the limitations of the prior art described above by the unique arrangement of two standard track relays, which each have a positive track terminal, a negative track terminal, and two local terminals. FIG. 10 illustrates this arrangement whereby the positive track terminal of the first track relay 18 is connected to one running rail 20 while the negative track terminal of the first track relay 18 is connected to the equalizer bar 9 . Further, the positive track terminal of the second track relay 19 is connected to the equalizer bar 9 while the negative track terminal of the second track relay 19 is connected to the other running rail 21 . The two local terminals of the first track relay and the two local terminals of the second track relay are each connected to the local power supply for voltage and phasing reference. These local terminals and the connections to the local power supply are not shown in FIG. 10 .
Normal operation is illustrated in FIG. 11 wherein track circuit current 5 flows through both the first track relay 18 and the second track relay 19 in series, thereby energizing both. The circuit interfacing to the signaling or train control system 22 is wired through normally energized, or “front”, contacts 23 and 24 respectively of the first and second track relays 18 and 19 . Such contacts are arranged in series so that the circuit is not completed unless both track relays 18 and 19 are energized. The presence of energy on this circuit at the interface to the signaling or train control system 22 corresponds to conditions where 1) the track circuit is vacant and 2) there is no broken rail within it.
Operation in the presence of a broken rail is depicted in FIG. 12 . The rail break 7 is located on the first running rail 20 . Track circuit current 5 flows through the cross bonding 12 and the equalizer bar 9 as it had in FIG. 9 . Due to the rail break 7 no current can flow along the first running rail 20 . The impedance bond 8 and second track relay 19 now form a parallel circuit between the equalizer bar 9 and the second running rail 21 . Accordingly the track circuit current splits to run through the impedance bond 8 and the second track relay 19 . The reduced current flowing through the second track relay 19 may or may not be sufficient to energize it. However this is of no consequence. It is readily seen that because of the rail break 7 no current will flow through the first track relay 18 . Therefore, even in the event that the second track relay 19 is energized, the first track relay 18 is assured to be de-energized. The front contact 23 of the first track relay 18 is thereby assured to be open, thereby de-energizing the interface circuit to the signaling or train control system 22 and ensuring protection for trains.
From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purpose of illustration, and that various modifications can be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims. | A railroad track circuit providing for the positive detection of broken rails despite the presence of factors that would otherwise preclude such detection is disclosed. These factors include sneak paths arising from the presence of negative return cross-bonding as applied between parallel tracks in electrified territory. Broken rail detection is ensured through the provision of two track relays, or devices that function as track relays, uniquely arranged so as to render the track circuit immune from these factors. | 1 |
BACKGROUND
[0001] The present invention relates to an intervertebral prosthetic assembly for stabilizing the human spine, and a method of implanting same.
[0002] Intervertebral discs that extend between adjacent vertebrae in vertebral columns of the human body provide critical support between the adjacent vertebrae while permitting multiple degrees of motion. These discs can rupture, degenerate, and/or protrude by injury, degradation, disease, or the like, to such a degree that the intervertebral space between adjacent vertebrae collapses as the disc loses at least a part of its support function, which can cause impingement of the nerve roots and severe pain.
[0003] Intervertebral prosthetic devices have been designed that can be implanted between the adjacent vertebrae, both anterior and posterior of the column. Many of these devices are supported between the spinous processes of the adjacent vertebrae to prevent the collapse of the intervertebral space between the adjacent vertebrae and provide motion stabilization of the spine.
[0004] However, in some cases it is often necessary to perform a laminectomy to remove the laminae and the spinous process from at least one vertebra to remove an intervertebral disc and/or to decompress a nerve root. Typically, in these procedures, two vertebral segments are fused together to stop any motion between the segments and thus relieve the pain. In this situation, it would be impossible to implant an intervertebral prosthetic device of the above type since the device requires support from the respective spinous processes of both adjacent vertebrae.
[0005] The present invention is thus directed to an intervertebral prosthetic assembly that is implantable between two adjacent vertebrae to provide motion stabilization, despite the fact that at least one vertebra is void of a spinous process. Various embodiments of the invention may possess one or more of the above features and advantages, or provide one or more solutions to the above problems existing in the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a side elevational view of an adult human vertebral column.
[0007] FIG. 2 is a posterior elevational view of the column of FIG. 1 .
[0008] FIG. 3 is an enlarged, front elevational view of one of the vertebrae of the column of FIGS. 1 and 2 .
[0009] FIG. 4 is an isometric view of a portion of the column of FIGS. 1 and 2 , including the lower three vertebrae of the column, and depicting an intervertebral prosthetic assembly according to an embodiment of the invention implanted between two adjacent vertebrae.
[0010] FIG. 5 is an enlarged view of a portion of the column and the assembly shown in FIG. 4 .
[0011] FIGS. 6 and 7 are views similar to that of FIG. 5 , but depicting alternate embodiments of the assembly of FIG. 5 .
[0012] FIGS. 8 and 9 are partial elevational/partial sectional views of two additional alternate embodiments of the assembly of FIG. 5 .
DETAILED DESCRIPTION
[0013] With reference to FIGS. 1 and 2 , the reference numeral 10 refers, in general, to the lower portion of a human vertebral column. The column 10 includes a lumbar region 12 , a sacrum 14 , and a coccyx 16 . The flexible, soft portion of the column 10 , which includes the thoracic region and the cervical region, is not shown.
[0014] The lumbar region 12 of the vertebral column 10 includes five vertebrae V 1 , V 2 , V 3 , V 4 and V 5 separated by intervertebral discs D 1 , D 2 , D 3 , and D 4 , with the disc D 1 extending between the vertebrae V 1 and V 2 , the disc D 2 extending between the vertebrae V 2 and V 3 , the disc D 3 extending between the vertebrae V 3 and V 4 , and the disc D 4 extending between the vertebrae V 4 and V 5 .
[0015] The sacrum 14 includes five fused vertebrae, one of which is a superior vertebra V 6 separated from the vertebra V 5 by a disc D 5 . The other four fused vertebrae of the sacrum 14 are referred to collectively as V 7 . A disc D 6 separates the sacrum 14 from the coccyx 16 , which includes four fused vertebrae (not referenced).
[0016] With reference to FIG. 3 , the vertebra V 5 includes two laminae 20 a and 20 b extending to either side (as viewed in FIG. 2 ) of a spinous process 22 that extends posteriorly from the juncture of the two laminae. Two transverse processes 24 a and 24 b extend laterally from the laminae 20 a and 20 b, respectively. Two articular processes 26 a and 26 b extend superiorly from the laminae 20 a and 20 b respectively, and two articular processes 28 a and 28 b extend inferiorly from the laminae 20 a and 20 b , respectively. The inferior articular processes 28 a and 28 b rest in the superior articular process of the vertebra V 2 to form a facet joint. Since the vertebrae V 1 -V 4 are similar to the vertebra V 5 , and since the vertebrae V 6 and V 7 are not involved in the present invention, they will not be described in detail.
[0017] Referring to FIGS. 4 and 5 it will be assumed that, for one or more of the reasons set forth above, the spinous process 22 of V 4 has been removed, the vertebrae V 3 , V 4 , and/or V 5 are not being adequately supported by the discs D 3 and/or D 4 , and that it is desired to provide supplemental support and motion stabilization for these vertebrae.
[0018] To this end, a spacer 40 is provided that is fabricated from a relatively flexible, soft material, and is substantially rectangular in shape with the exception that a curved notch, or saddle, 40 a is formed at one end for receiving the spinous process 22 of the vertebra V 3 .
[0019] A through opening 40 b extends through the spacer in a spaced relation to the saddle 40 a , and a flexible cross-bar 42 extends through the opening 40 b in the spacer 40 and generally transverse to the axis of the spine. The cross-bar 42 spans a substantial portion of the width of the vertebra V 4 .
[0020] Two transversely-spaced retainers 44 a and 44 b ( FIG. 4 ) are fastened to the vertebra V 4 by two screws 46 a and 46 b , respectively. Each screw 46 a and 46 b has a head (not shown) extending in a corresponding retainer, and an externally threaded shank extending from the head that is screwed in the vertebra V 4 . The respective end portions of the cross-bar 42 extend through openings in the retainers 44 a and 44 b.
[0021] A strap 48 extends through another opening 40 c in the spacer 40 and around the process 22 of the vertebra V 3 to secure the spacer to the process.
[0022] The spacer 40 is thus firmly secured in its implanted position shown in FIG. 4 , and stabilizes the vertebrae V 3 -V 5 . Also, the relatively flexible, soft spacer 40 readily conforms to the process 22 of the vertebra V 3 and provides excellent shock absorption and deformability, resulting in an improved fit.
[0023] The embodiment of FIGS. 6 and 7 is similar to that of FIGS. 4 and 5 and identical components are given the same reference numerals. According to the embodiment of FIGS. 6 and 7 , a spacer 50 is provided that is fabricated from a relatively flexible, soft material, and is substantially rectangular in shape with the exception that a saddle 50 a is formed at one end of the spacer for receiving the spinous process 22 of the vertebra V 3 . Also, a transversely extending notch, or groove 50 b is formed in the other end of the spacer 50 , and two through openings 50 c and 50 d extend through the spacer, for reasons to be described.
[0024] A central portion of the cross-bar 42 of the previous embodiment extends into the notch 50 b and generally transverse to the axis of the spine, and spans a substantial portion of the width of the vertebra V 4 . As in the previous embodiment, the respective end portions of the cross-bar 42 extend through openings in the retainers 44 a and 44 b ( FIG. 4 ) which are mounted to the vertebra V 4 by the screws 46 a and 46 b , respectively. The strap 48 extends through the opening 50 c in the spacer 50 and around the process 22 of the vertebra V 3 to secure the spacer to the vertebra. According to the embodiment of FIGS. 6 and 7 , a second strap 52 ( FIG. 7 ) extends through the opening 50 d in the spacer 50 and around the notch 50 b and the cross-bar 42 , to secure the cross-bar to the spacer.
[0025] The spacer 50 is thus firmly secured in the same implanted position as shown in connection with the spacer 40 of the embodiment of FIGS. 4 and 5 , and stabilizes the vertebrae V 3 -V 5 . Also, the relatively flexible, soft, spacer 50 readily conforms to the process 22 of the vertebra V 3 and provides excellent shock absorption and deformability resulting in an improved fit.
[0026] The embodiment of FIG. 8 is similar to that of the embodiments and FIGS. 4 and 5 and identical components are given the same reference numerals. According to the embodiment of FIG. 8 , a spacer 60 is provided that is fabricated from a relatively flexible, soft material, and is substantially rectangular in shape with the exception that a saddle 60 a is formed at one end for receiving the spinous process 22 of the vertebra V 3 .
[0027] A flexible cross-bar 62 is provided that has two slightly-spaced, circular flanges 62 a and 62 b formed on its central portion. The central portion of the cross-bar 62 , along with the flanges 62 a and 62 b are embedded in the spacer 60 in any conventional manner, such as by forming the spacer of a rubber material and molding it over the cross-bar.
[0028] As in the previous embodiments, the respective end portions of the cross-bar 62 extend through openings in the retainers 44 a and 44 b ( FIG. 4 ), which are mounted to the vertebra V 4 by the screws 46 a and 46 b , respectively, as described above. Also, although not shown in FIG. 8 , it is understood that the strap 48 of the embodiment of FIGS. 4 and 5 can extend through the spacer 60 and around the process 22 of the vertebra V 3 to secure the spacer to the vertebra.
[0029] The spacer 60 is thus firmly secured in the same implanted position as shown in connection with the spacer 40 of the embodiment of FIGS. 4 and 5 , and stabilizes the vertebrae V 3 -V 5 . Also, the relatively flexible, soft spacer 60 readily conforms to the process 22 of the vertebra V 3 and provides excellent shock absorption and deformability resulting in an improved fit.
[0030] The embodiment of FIG. 9 is similar to that of FIGS. 4-8 and identical components are given the same reference numerals. According to the embodiment of FIG. 9 a spacer 70 is provided that is fabricated from a relatively flexible, soft material, and has a generally U-shaped cross section. A saddle 70 a is defined at one end of the spacer 70 for receiving the spinous process 22 of the vertebra V 3 .
[0031] A flexible cross-bar 72 is provided that has two slightly-spaced protrusions 72 a and 72 b that extend transverse to the axis of the cross-bar and form, with the corresponding portion of the cross-bar, a U-shaped portion that receives the spacer 70 . In this context, the spacer 70 could be formed of a rubber material that is molded over the cross-bar 72 .
[0032] As in the previous embodiments, the respective end portions of the cross-bar 72 extend through openings in the retainers 44 a and 44 b ( FIG. 4 ), which are mounted on the vertebra V 4 by the screws 46 a and 46 b in the manner described above. Also, although not shown in FIG. 9 , it is understood that the strap 48 of the embodiment of FIGS. 4 and 5 can extend through the spacer 70 and around the process 22 of the vertebra V 3 to secure the spacer to the vertebra.
[0033] The spacer 70 is thus firmly secured in the same implanted position as shown in connection with the spacer 40 of the embodiment of FIGS. 4 and 5 , and therefore stabilizes the vertebrae V 3 -V 5 . Also, the relatively flexible, soft spacer 70 readily conforms to the process 22 of the vertebra V 3 and provides excellent shock absorption deformability resulting in an improved fit.
Variations
[0034] It is understood that variations may be made in the foregoing without departing from the invention and examples of some variations are as follows:
[0035] (1) The assemblies of the above embodiments can be inserted between two vertebrae following a discectemy in which a disc between the adjacent vertebrae is removed, or corpectomy in which at least one vertebrae is removed.
[0036] (2) The cross-bars in each of the previous embodiments can be rigidly connected to the pedicles of the vertebra by means other than the screws and retainers described in the above examples.
[0037] (3) The components disclosed above can be fabricated from materials other than those described above and may include a combination of soft and rigid materials.
[0038] (4) Any conventional substance that promotes bone growth, such as HA coating, BMP, or the like, can be incorporated in the spacers in the above embodiments.
[0039] (5) The surfaces of the spacers disclosed above that define the saddles that receive the spinous process can be treated, such as by providing teeth, ridges, knurling, etc., to better grip the spinous process.
[0040] (6) The spacers disclosed above can be fabricated of a permanently deformable material thus providing a clamping action against the spinous processes.
[0041] (7) One or more of the components disclosed above may have through-holes formed therein to improve integration of the bone growth.
[0042] (8) The components of one or more of the above embodiments may vary in shape, size, composition, and physical properties.
[0043] (9) Through-openings can be provided through one or more components of each of the above embodiments to receive tethers for attaching the devices to a vertebra or to a spinous process.
[0044] (10) The assemblies of each of the above embodiments can be placed between two vertebrae in the vertebral column other than the ones described above.
[0045] (11) The number and lengths of the cross-bars in one or more of the embodiments can be varied.
[0046] (12) The cross-bars can be flexible or rigid.
[0047] (13) The assemblies of the above embodiments can be implanted between body portions, or anatomical structures other than vertebrae.
[0048] (14) The spatial references made above, such as “under”, “over”, “between”, “flexible, soft”, “lower”, “top”, “bottom”, “axial”, “transverse”, etc. are for the purpose of illustration only and do not limit the specific orientation or location of the structure described above.
[0049] The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood, therefore, that other expedients known to those skilled in the art or disclosed herein, may be employed without departing from the invention or the scope of the appended claims, as detailed above. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts a nail and a screw are equivalent structures. | A prosthetic assembly and method of implanting same, according to which a least one cross-bar is secured to the spinal column. A spacer engages the spinous process of a vertebra of the spinal column. The cross-bar is connected to the spacer via an adapter. | 0 |
This application claims the priority of Provisional Application No. 60/070,887 filed Jan. 9, 1998.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the field of separation of molecules using selective adsorbents.
2. DESCRIPTION OF THE ART
Since its discovery by Tswett nearly a century ago, the technique of adsorption chromatography has evolved into a tool of fundamental importance to the biological and chemical sciences. Early chromatographers employed readily available adsorbents such as calcium carbonate, sugar, starch, paper, wool, silk, alumina and silica to perform an impressive variety of separations. Today, researchers with a problem separation are faced with a variety of adsorbents from which to choose. Furthermore, additional adsorbents can readily be prepared using combinatorial chemistry approaches. As a general rule, the more selective adsorbents allow for more economical chromatographic separations, with simple and inexpensive batch adsorption separations becoming possible with extremely selective adsorbents. A means of rapidly finding the most selective adsorbent for a given separation task is needed.
One area where the development of highly selective adsorbents is of great importance is the large scale separation of enantiomers using chiral stationary phases (CSPs). The current selection of commercial chiral stationary phases (CSPs) for large scale chromatographic separations is rather limited, and most have been developed as general purpose CSPs rather than the best CSP for a particular separation. While new CSPs can be designed, the development time is often too long to merit serious consideration by process engineers.
Within the past decade the technique of chromatographic enantioseparation has become the method of choice for analytical determinations of enantiopurity. Allenmark, Chromatographic Enantioseparation: Methods and Applications, Ellis Horwood, N.Y., 1991. The method is widely used, particularly in the pharmaceutical industry where most new chiral drugs are manufactured in enantiomerically pure form. In recent years the use of preparative chromatographic enantioseparation has become increasingly popular. While generally more expensive than manufacturing routes employing enantioselective synthesis or classical resolution, chiral HPLC offers a considerable advantage of speed. Consequently, many pharmaceutical companies use preparative chiral HPLC in the early stages of drug discovery to rapidly produce enantiomerically pure drug candidates for animal testing, metabolism and toxicology studies, etc. Once a drug candidate has been selected for larger scale development, alternative manufacturing methods are often used, although in a few cases chiral HPLC is used to produce enantiopure drugs on large scale.
Most commercial CSPs have been developed using trial and error methodology, and have been commercialized because they demonstrate some general ability to separate enantiomers. Of these many commercial CSPs, only a small fraction are available in bulk or can be produced in an economical fashion for large scale preparative chromatography. Francotte, E., J. Chromatogr ., 666, 565-601, 1994. Furthermore, rather than a CSP which has a general ability to separate the enantiomers of a large number of racemates, the process engineer considering a potential manufacturing route for an enantiopure drug is interested in a CSP which can separate the enantiomers of one particular compound.
Practical large scale chromatographic enantioseparation requires highly enantioselective CSPs. For example, chromatographic resolution of the enantiomers of a racemate using a CSP with an enantioselectivity of 1.3 can be rather tedious. A comparable CSP having an enantioselectivity of 2 can sometimes afford 5-10 fold greater productivity.
SUMMARY OF THE INVENTION
The present invention relates to a process for screening candidate selective adsorbents for differential adsorption of two or more chemical components. In this process a solid phase consisting of the candidate adsorbent is allowed to contact a solution phase containing the component or components of interest. Interaction or equilibration of material in the solution phase with the stationary phase of the selective adsorbent results in a change of concentration of the analyte or analytes in both the stationary phase and solution phase. This change in concentration can be measured by a variety of techniques and gives an indication of the degree of adsorption of the analyte by the stationary phase. Thus, small amounts of candidate selective adsorbents are placed in an array of containers and a solution of the chemical compounds to be separated is added to each container. The components are allowed to interact or equilibrate with the selective adsorbent and the amount of each component in the solution phase or in the solid phase of the array of containers is measured. The adsorbent showing the greatest differential adsorption for the chemical components is identified as being potentially useful for large scale separations. The invention is particularly useful in identifying selective adsorbents for enantiomer separations.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is an expanded view of the solid phase prior to equilibration.
FIG. 2 is an expanded view of the liquid phase prior to equilibration.
FIG. 3 is a view of the liquid and solid phase after equilibration.
FIG. 4 shows that the performance of the DNB Leu CSP prepared by solid phase synthesis is comparable with the performance of the commercial version of this CSP.
FIG. 5 shows a variety of DNB-peptido CSPs prepared by solid phase synthesis.
FIG. 6 illustrates substantial differences in the performance of structurally similar dipeptide and tripeptide CSPs.
FIG. 7 illustrates five amino acids used to prepare a library of 50 dipeptide DNB CSPs and the test racemate, 1 , used for evaluation.
FIG. 8 shows three representative screening chromatograms including the blank (no CSP), a CSP which strongly adsorbs the (R) enantiomer of the test racemate, 1 , and a CSP which strongly adsorbs the (S) enantiomer of the test racemate, 1 .
FIG. 9 shows the results of a screening of a library of 50 dipeptide DNB CSPs for the separation of the enantiomers of test racemate, 1 .
FIG. 10 shows results of a screening of a focused library of dipeptide DNB CSPs containing hydrogen-bonding sidechains in the aa 1 position and sterically bulky sidechains in the aa 2 position. Many of these second generation CSPs are superior to the best CSPs in the library shown in FIG. 9 .
FIG. 11 shows a separation of the enantiomers of test racemate, 1 , using a conventional 4.6×250 mm analytical HPLC column containing one of the best dipeptide DNB CSPs from FIG. 10 .
FIG. 12 shows preparative HPLC separation of the enantiomers of the test racemate, 1 , using the column from FIG. 11 .
FIG. 13 illustrates four libraries of DNB tripeptide CSPs.
FIG. 14 illustrates the results of the screening of leucine library from FIG. 13 for enantioselective naproxen recognition.
FIG. 15 illustrates chromatographic separation of the enantiomers of the drug, naproxen, using the best CSP indicated by the CSP library screening shown in FIG. 14 .
FIG. 16 illustrates libraries of acyl amino acid CSPs comprised of four different amino acids each acylated with 40 different carboxylic acids.
FIG. 17 illustrates the results of the screening of two of the acyl amino acid libraries from FIG. 16 for enantioselective recognition of test racemate, 1 . In both instances, 3,5-dinitrobenzamide and 4-methyl, 3,5-dinitrobenzamide are shown to be superior to other acyl groups.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention encompasses a method whereby candidate selective adsorbents can be rapidly evaluated for their potential for carrying out the separation of a mixture of two or more chemical components. Using this method, libraries containing small amounts of about 1 mg to 100 mg of many different candidate adsorbents can be rapidly evaluated using automated equipment. This approach dramatically decreases the time required to find a suitable selective adsorbent for a given separation. The method is useful for finding adsorbents which can be used for the analytical or preparative chromatographic separation of enantiomers, the separation of impurities from pharmaceuticals or other products, the separation of fermentation products from their associated impurities or any process in which two or more compounds are separated by a chromatography or any process which relies upon differential adsorption of two or more chemical species. The method has the added advantage that the compound mixture for which a separation is desired can be used directly without the need for separations, purifications, radiolabeling or other chemical derivatization.
The screening process is depicted schematically in the figures which follow. A small amount of a candidate absorbent is placed in a vial or similar receptacle (FIG. 1 ). The expanded view of the candidate absorbent shows two particles containing four pendant selectors each. Any number of particles can be used, and in contrast to chromatography, the performance of the assay does not require the use of very small and regular particles. Indeed, there are some advantages to be found in the use of large particles or even a single bead. For example, since larger particles tend to settle more rapidly and completely, the use of large particles allows the supernatant solution to be sampled without risk of particles clogging the syringe.
In the case where a solid phase material which preferentially binds one enantiomer is desired (e.g. a chromatographic chiral stationary phase) the preferred method involves adding a solution of the racemic mixture to the candidate chromatographic adsorbents and measuring the enantioenrichment of either the solution phase or the stationary phase using chromatographic techniques such as chiral HPLC, HPLC/MS, GC, CE or spectroscopic techniques such as NMR with chiral solvating agents or NMR analysis of diastereomeric derivatives or chiroptical spectroscopic techniques such as CD or polarimetry. An alternative method of performing the assay could involve analysis of a nonracemic solution of the target analyte or could involve independently measuring the degree of complexation of each enantiomer.
A dilute solution containing known relative concentrations of the mixture of the analytes of interest is then added (FIG. 2 ). In this example, two analytes are represented as circles and crosses. It is important that the analyte solution be of low enough concentration to prevent saturation of the adsorption sites on the chromatographic adsorbent. In addition, the polarity of the solution phase should be such that the target molecules are neither completely adsorbed nor completely free in solution. Equilibration or interaction of the material in the liquid phase with the chromatographic adsorbent may result in the preferential binding of one of the analytes in the mixture to the chromatographic adsorbent, resulting in a depletion of that analyte in the solution phase.
Analysis of the relative abundance of the analytes in either the solid phase or the solution phase gives some indication of the degree of selectivity of the adsorbent-analyte interaction. In the case illustrated here, a strong preference for adsorption of the circular analyte is depicted. Those adsorbents which show the highest degrees of selectivity are likely candidates for a chromatographic stationary phase which may be capable of separating the mixture of chemical components in question, FIG. 3 .
This technique has several advantages over previous methods of evaluating candidate selective adsorbents. Only a small amount, about 1 mg to 100 mg, of the candidate adsorbent is used in an assay, and this material need not be packed into a column or capillary for evaluation. Furthermore, the candidate adsorbent can be washed free of all chemical components and reused. The target analytes can be used directly without any need for purifications, resolutions, or synthetic operations. A variety of analytical techniques can be used to measure the relative abundance of the analyte molecules in either the solid phase or the solution phase. The process is not limited to mixtures of two analytes, but could conceivably be used to screen for e.g., an adsorbent which would show preferential adsorption of a single desired product from a complex mixture containing a number of different associated impurities. Similarly, the technique could conceivably be used to search for an adsorbent which would preferentially adsorb the various impurities from this same complex mixture while only weakly adsorbing the desired product. The screening process is rapid, and is amenable to automation, which allows for high throughput screening of libraries of new candidate chromatographic adsorbents prepared using solid phase diversity-generating synthetic approaches.
A variety of analytical tools can be used to determine the relative concentrations of the analytes in the solid phase. For example, analysis of the relative concentrations of the analytes in the liquid phase can be performed using chromatographic techniques such as HPLC, HPLC/MS, SFC, CE or GC or spectroscopic techniques such as NMR or chiroptical techniques such as CD or any analytical technique or chemical process capable of showing the absolute or relative concentrations of the analytes in question.
Determination of the relative concentrations of the analytes in the solid phase can be done by a variety of methods. The extent of enrichment in the solid phase is typically greater than that in the supernatant solution. However, these measurements are often more difficult, usually requiring a filtration or other phase separation before the determination of the relative concentration of materials adsorbed onto the solid phase can be determined. A convenient method for determining the relative concentration of the analytes in the solid phase simply involves removal of the supernatant layer by rapid suction filtration, followed by the addition of a solvent which liberates most of the adsorbed material from the solid phase, followed by analysis of the resulting supernatant solution by HPLC or other analytical techniques mentioned above.
Those skilled in this art will recognize that a wide variety of solid polymeric or inorganic particles may be functionalized to form candidate selective adsorbents using techniques and procedures which are known from the fields of solid phase synthesis and combinatorial chemistry. Such particles bearing pendant groups such as amine, carboxylic acid, hydroxyl, halide, aldehyde, or thiol may be used for attachment of one or more molecular fragments to provide a large number of candidate selective adsorbents. Further, by linking enantiopure moieties to functionalized solid particles, a large number of candidate CSPs and CSP libraries can be prepared.
Suitable candidate adsorbents are made by techniques described in the following examples or can be purchased from Regis Technologies, Inc., 8210 Austin Avenue, Morton Grove, Ill. 60053-0519.
EXAMPLE 1
Silica-Based Solid Phase Synthesis.
Modified solid phase peptide synthesis on aminopropyl silica particles was chosen as a preferred method for preparing combinatorial libraries of CSPs.
Silica-Based Solid Phase Synthesis of DNB-Leu CSP
As a model study, the well known 3,5-dinitobenzoyl Leucine (DNB-Leu) CSP was prepared on 5 g scale using the solid phase synthesis protocol outlined in FIG. 4 . The CSP thus obtained was packed in a column which separated a group of test analytes nearly as well as the commercial column.
Silica-Based Solid Phase Synthesis of DNB-Peptido CSPs
Preparing and evaluating a group of peptido CSPs using a split synthesis was conducted in a manner analagous to that shown in FIG. 4. A representative sampling of some of the CSPs which were made and evaluated is shown in FIG. 5 . Each CSPs was prepared on 5 g scale, packed into a column and evaluated chromatographically. Two additional CSPs from this initial group are shown in FIG. 6 . These CSPs are nearly identical, differing only in one leucine residue. Nevertheless, substantial differences in enantioselectivity are noted for the group of test analytes.
Microscale Silica-Based Solid Phase Synthesis of CSPs
The foregoing experiments show the utility of a silica based solid phase synthesis approach to CSP development. While the cost and time required to make each of these materials on 5 g scale is less than that of conventional CSP development, an even more rapid way of sampling the structural diversity of the DNB peptide family was required. Consequently, candidate CSPs on 50 mg scale were prepared and screened ex-column to evaluate the enantioselectivity of each CSP.
A library of 50 dipeptide DNB CSPs were prepared using combinations of the 5 amino acids; valine, glutamine, phenylalanine, phenylglycine and proline (FIG. 7 ). This set includes sterically bulky, strong hydrogen bonding and aromatic amino acids.
The solid phase peptide synthesis which was used in the multigram scale preparation of the CSPs shown in FIGS. 5 and 6 was scaled down to prepare 50 mg of each of 50 dipeptide DNB CSPs resulting from combinations of the 5 amino acids shown in FIG. 7 .
Evaluation of CSP Library
The CSP library was first evaluated using the test racemate, 1 . The evaluation procedure consists of adding 1 ml of a 1×10 −5 M solution of the test racemate in 20% IPA/hexane to each of the 50 CSP-containing vials. The vials were then capped and transferred to an HPLC autosampler, where they were allowed to sit for a period of 30 min. HPLC analysis of 50 μl of the supernatant solution from each vial was performed using a 46×250 mm (S) DNB-Leucine CSP operating at a flow rate of 1 ml/min with a mobile phase of methanol and detection at 254 nm. Three representative chromatograms are shown in FIG. 8, including the blank (no CSP), a CSP which strongly adsorbs the (R) enantiomer of the test racemate, and a CSP which strongly adsorbs the (S) enantiomer of the test racemate. The results of the screen are presented in FIG. 9 . The vertical axis in FIG. 9 represents enantioselectivity, with the tallest bars indicating the most enantioselective CSPs. The overall method provides useful information on the separation capability of each material. Previous experience with this chiral recognition system had led us to believe that an amide hydrogen on the amino acid closest to the DNB group (aa 2) is essential for good separation. Furthermore, it was suspected that amino acids with a large steric group at this position should work best, with aromatic groups at this position generally being poorer than steric groups. It thus comes as no surprise that the proline in position aa 2 works very poorly, while valine and phenylalanine in this position work best. Some unexpected results are obtained, even though this chiral recognition system has been extensively studied for more than a decade by a variety of techniques in addition to chromatography, including X-ray analysis of co-crystals and nOe NMR analyses of 1:1 complexes. One unexpected result of the screen is the finding that glutamine in position aa 1 seems to have a beneficial effect on enantioselectivity.
Preparation and Evaluation of a Focused CSP Library
This initial screen provides a basis for further optimization for this chiral recognition system. The initial screen indicates that DNB dipeptide CSPs having a strong hydrogen bonding sidechain in the aa 1 position and a sterically bulky sidechain in the aa 2 position work best for the test analyte. A focused library based on this motif was prepared and evaluated. As shown in FIG. 10, many of the members of this new library show superior enantioselectivity to the DNB Val-Gln CSP, which was the best CSP in the initial library.
Selection, Scale-Up and Evaluation of an ‘Optimal’ CSP
One of the preferred CSPs shown in FIG. 10 was prepared on 5 g scale and packed into 4.6×250 mm HPLC column for evaluation. As shown in FIG. 11, this HPLC column was shown to separate the enantiomers of the test analyte, 1 , with an enantioselectivity in excess of 20. This HPLC column was shown to be highly effective for the preparative separation of the enantiomers of the test analyte, 1 , as shown in FIG. 12 . In this example, near baseline resolution of enantiomers is observed, even with a single injection of 100 mg of racemate. Analysis of the two fractions from this preparative separation shows that the collected enantiomers are isolated in a highly enantioenriched form. Furthermore, the relatively rapid separation time permits a very high preparative throughput.
This example illustrates the utility of the technology for the discovery of a highly selective adsorbent for a given separation problem.
EXAMPLE 2
Using an approach analogous to that described in Example 1, a series of tripeptide DNB CSPs were prepared and evaluated. Four such libraries of 36 CSPs each were prepared by analogous solid phase synthesis techniques and are shown in FIG. 13 . Evaluation of this CSP library as candidate adsorbents for separation of the enantiomers of the drug, naproxen, revealed several promising library members, as shown in FIG. 14 . FIG. 15 shows the evaluation of the best CSP indicated by the library screening shown in FIG. 14 using a 4.6×250 mm HPLC column.
EXAMPLE 3
Using an approach analogous to that described in Example 1, the series of acyl amino acid CSPs shown in FIG. 16 were prepared. Several different BOC amino acids were coupled with aminopropylsilica, followed by deprotection to afford the corresponding CSPs bearing a free terminal amino group. These CSPs were next transferred to individual vials, where they were coupled with each of a group of 40 different carboxylic acids. The resulting library of acyl amino acid derived CSPs was screened for ability to separate the enantiomers of the test racemate, 1 . The results of the screens for two such sub-libraries are shown in FIG. 17 . These results emphasize the fact that 3,5 dinitrobenzamide groups works well for separation of the enantiomers of test racemate, 1 .
EXAMPLE 4
This example illustrates that the technique is not limited to CSP libraries on a silica surface. We have prepared and evaluated a subset of the library illustrated in FIG. 9 using polystyrene based media. In this example, Chiron SynPhase™ Crowns (PS Crown Type:I series: aminomethylated) were used to prepare several CSPs in the dipeptide DNB series. Evaluation of the resulting Crown CSPs showed results which were similar to those found in Example 1, although some differences were noted. The use of polystyrene as a solid phase may be of some use for the preparation of adsorbent libraries owing to the fact that many types of solid phase synthesis are possible on polystyrene or other media which are not possible with silica. Furthermore, existing solid phase libraries can be accessed and evaluated as candidate adsorbents.
EXAMPLE 5
Several members of the CSP library described in Example 1 were evaluated for their ability to selectively adsorb the enantiomers of the test racemate, 1 , using HPLC with MS detection. The evaluation procedure was the same as that described in Example 1, except that HPLC evaluation was performed using a 46×250 mm (R) DNB-Phenylglycine CSP operating at a flow rate of 1 ml/min with a mobile phase of 1:1:1 methanol/acetonitrile/water with detection by mass spectrometry. This detection method was shown to afford essentially the same information obtained using UV detection, and in other cases where the analyte under investigation has poor UV absorbance, HPLC with MS detection has proven to afford the requisite sensitivity and reliability for direct screening of the CSP libraries.
EXAMPLE 6
An indirect chemical derivatization method was used to evaluate several CSP libraries for their ability to separate the enantiomers of a racemic secondary amine which had poor UV absorbance and was not well separated by chiral HPLC. A 10 −4 M solution of the racemic secondary amine in 5% IPA/hexane was added to a group of vials, each containing about 50 mg of a different candidate CSPs on a porous silica support. After waiting for one hour, 500 μl of supernatant solution was withdrawn from each vial and transferred to a fresh autosampler vial. 3,5-dinitrobenzoyl chloride (5.5×10 −7 moles) and diisopropylethylamine chloride (6×10 −7 moles) were then added to each vial. After two hours of reaction, the contents of each vial was analyzed using an autosampler HPLC system with UV detection.
These examples illustrate the invention and are not intended to limit in spirit or scope. | The invention discloses a method for rapid identification of a candidate selective separation material by placing small samples of the candidate material in an array of vials and adding a solution of the analytes to be separated. The solution is allowed to interact or equilibrate and the distribution of the analytes in the solid or liquid phase is measured usually by gas or liquid chromatography. The identified candidate material with the greatest differential adsorption of the analytes is selected and used as an adsorbent for large scale separation. The rapid screening of chromatographic adsorbents provides an efficient way of finding suitable absorbent materials for large scale separations. | 2 |
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